cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparative Evaluation of Rate Modulated Dual Chamber and VVIR Pacing

JUTZY, R.V., ET AL.: Comparative Evaluation of Rate Modulated Dual Chamber and VVIR Pacing. While dual chamber pacing is considered superior to VVI pacing at rest, there is a continuing debate as to the relative benefit of AV synchrony versus rate increase with exercise. To evaluate this question and to correlate different methods of evaluation, 14 patients with DDDR pacemakers were studied using serial treadmill exercise test with a CAEP protocol. Patients were exercised in DDD, DDDR, and VVIR modes. Echo-Doppler cardiac outputs were determined and pulmonary gas exchange was measured during exercise. There was a significant improvement in cardiac output with exercise in the DDDR versus VVIR modes, and in DDDR versus DDD modes in patients with chronotropic incompetence. There were small increases in exercise duration in DDDR versus VVIR modes, and small but consistent increases in VO, at all levels of exercise, though not statistically significant. In this group of patients, DDDR pacing was superior to VVIR pacing, and superior to DDD pacing when chronotropic incompetence was present.
Precursors to X-ray bursts - The result of expansion and subsequent contraction of the neutron star's photosphere

Observations de deux phenomenes transitoires rapides avec des precurseurs de quelques secondes de duree et separes des evenements principaux de quelques secondes
Phenotype-genotype relationships in complementation group 3 of the peroxisome-biogenesis disorders.

Summary The peroxisome-biogenesis disorders (PBDs) are a set of often lethal genetic diseases characterized by mental retardation and defective peroxisomal matrix protein import. Mutations in PEX12 are known to underlie the disease in two patients from complementation group 3 of the PBDs. Here we show that all patients from this group carry mutations on both alleles of PEX12. A comparison between PEX12 genotypes and the clinical and cellular phenotypes of the corresponding PBD patients suggests a relatively straightforward relationship between genotype and phenotype in this group of the PBDs, such that the loss of PEX12 function leads to more-severe cellular and clinical phenotypes. However, one patient who presented relatively mild clinical and cellular phenotypes was a compound heterozygote for two seemingly severe mutations on each PEX12 allele. PEX12 mRNA present in the patient's cells was derived from only one allele, the one that carried a 2-bp deletion early in the PEX12 coding region, c.26,27‡. The deduced protein product of this mRNA would contain only the first eight amino acids of the protein, and yet this mutant PEX12 cDNA displayed significant PEX12 activity in a functional complementation assay. Surprisingly, the PEX12/c.26,27‡ cDNA directed the synthesis of a 29-kD PEX12 protein in vitro, a result that is consistent with translation initiation at a downstream AUG codon. Transfection studies confirmed the expression of similarly sized PEX12 proteins from the PEX12 /c.26,27‡ allele. Thus, it appears that translation initiation at internal AUG codons may modulate disease phenotypes and should be considered whenever unexpectedly mild phenotypes result from severe mutations early in the coding region.
The pattern of labor preceding uterine rupture.

Objective We sought to characterize the labor of women attempting trial of labor after cesarean (TOLAC) who experience uterine rupture. Study Design We conducted a secondary analysis of a nested case-control study of women attempting TOLAC. Women experiencing uterine rupture (cases) were compared to 2 reference groups: successful TOLAC and failed TOLAC. Interval-censored regression was used to estimate the median time to progress 1 cm in dilation and the total time from 4-10 cm. Results A total of 115 cases were compared to 341 successful TOLAC and 120 failed TOLAC. The time to progress 1 cm was similar between groups until 7-cm dilation. After 7 cm, cases of uterine rupture required longer to progress than successful TOLAC (median [95th percentile] time from 7-8 cm: 0.38 [1.91] vs 0.16 [0.79] hours; from 8-9 cm: 0.28 [1.10] vs 0.10 [0.39] hours). Women with a uterine rupture had labor curves similar to those with a failed TOLAC. Conclusion Women with labor dystocia in the active phase of labor should be closely monitored for uterine rupture in TOLAC.
MBE growth and characterization of epitaxial TiO2 and Nb-doped TiO2 films

Abstract Epitaxial TiO2 and Nb-doped TiO2 thin films have been grown on (110) TiO2 rutile substrates by molecular beam epitaxy using elemental Ti and Nb sources along with an electron cyclotron resonance oxygen plasma source. Film composition was measured by X-ray photoelectron spectroscopy. Reflection high-energy electron diffraction and low-energy electron diffraction patterns reveal excellent long-range crystallographic order and a rutile structure for both TiO2 and Nb-doped TiO2 films. The high degree of similarity in Ti and Nb core-level X-ray photoelectron diffraction angular distributions establishes that Nb is substitutionally incorporated in the rutile lattice. Analysis of the Nb 3d 5 2 core-level binding energy suggests am Nb4+ oxidation state.
Breast cancer coverage in China and the United States: a comparative analysis of wire service news stories

The incidence rate of breast cancer is relatively high but declining in the United States whereas it is relatively low but increasing in China. This study analyzes coverage from the Associated Press (AP) and the Xinhua News Agency (Xinhua) to compare how news media in each nation have covered breast cancer. The results indicate that the AP was more likely to cover treatment and personal stories whereas Xinhua was more likely to cover risk reduction and prevention and to cover early detection and diagnosis. Subtler differences also emerged in coverage of breast cancer. The patterns observed may reflect not only differences between the two nations in incidence rates and efforts to address the disease but also broader differences in their news and medical values, practices, and institutions. News coverage of breast cancer, in turn, may influence how citizens of each nation will form perceptions regarding the disease.
Mean and variable flow over the central California continental margin, 1978 1980

Abstract Based on two years (July 1978–June 1980) of current meter array measurements and bimonthly STD/XBT transects over the continental margin off central California, the mean California Undercurrent has a jet-like core in excess of 15 cm s−1 which is generally confined to the upper 300 m of the water column and to within 30 km of the coast. A comparison of measured current velocities with relative geostrophic velocities suggests, on average, a poleward flow of 10 cm s−1 at the reference level, 450 db. The variability is predominantly annual with a maximum poleward flow in May–June. Equatorward flow was suprisingly weak and infrequent in the transect studied. The alongshore flow has characteristic fluctuations of 15 cm s−1 on time scales of a few days to weeks. The strongest and most coherent element of variation is the “spring transition”, which had different manifestations in the two years observed, perhaps due to differences in the combination of local and remote forcing. The spring transition is characterized by an abrupt decrease in subsurface temperature which is well-correlated with a coastal sea surface temperature (SST) decrease, an upwelling index increase, and a transient reduction or reversal of the poleward flow. The subsurface current and temperature fluctuations are associated with coastal SST and wind fluctuations, and with satellite infra-red imagery patterns and changes.
Survival of Children Requiring Repeat Extracorporeal Membrane Oxygenation After Congenital Heart Surgery

Background Clinical indications and outcomes for children requiring multiple extracorporeal membrane oxygenation (ECMO) runs during a single hospital admission are rarely reported. We review indications, cannulation techniques, and outcomes for infants requiring multiple ECMO runs after congenital heart surgery. Methods Demographic and ECMO-related data for all children requiring multiple ECMO runs during a single hospital admission from1995 to 2008 were extracted from our institution's ECMO database. Survival was defined as survival to hospital discharge. Demographic and ECMO data were compared between survivors and nonsurvivors using the Mann-Whitney test for continuous and Fisher's exact test for categorical data. Results Twenty children (5% of 391 ECMO runs) with a median age of 5 days (range, 4 to 180 days) and weight of 3.22 kg required repeat ECMO support for persistent cardiopulmonary dysfunction despite successful weaning from an index ECMO run. Of the two-ventricle repair group, tetralogy of Fallot, truncus arteriosus, and transposition constituted the majority of cardiac diagnoses (75%), whereas single-ventricle physiology made up the rest (25%). The median total ECMO duration was 191 hours (range, 77 to 485 hours), and median hospital length of stay was 41 days (range, 6 to 297 days). Five (25%) patients survived to discharge. When survivors were compared with nonsurvivors, there were no significant differences in demographics, single or biventricular repair, indication for ECMO support, or need for surgical reoperation while on ECMO. However, the incidence of renal failure was higher in nonsurvivors than in survivors after multiple ECMO runs (12 versus 2.0; p = 0.03). Conclusions Survival in children undergoing congenital heart surgery requiring multiple ECMO runs is low, but 1 in 4 patients will survive to discharge. If a correctable lesion or ventricular impairment is present, repeat ECMO support may be justified. Development of renal failure is associated with nonsurvival in these patients.
Electronic-structure studies of the Nb (110) surface

The electronic structure of the Nb (110) surface is studied using angle-resolved photoemission. The properties of the ${\ensuremath{\Sigma}}_{1}$ band crossing at the Fermi energy are examined in detail. A comparison is made with similar measurements for Mo (110) to evaluate the validity of a rigid-band approximation. The final states along $\ensuremath{\Sigma}$ are also studied using synchrotron radiation as a source.
High Energy and High Power Pulsed Chirally-Coupled Core Fiber Laser System

Pulsed amplifier using chirally-coupled-core Yb-doped double-clad fiber is demonstrated at average powers above 100W and 10-ns pulse energies exceeding 1mJ, with pure single-mode output at all powers and energies independently from coiling and excitation conditions.
Does shrub invasion indirectly limit grass establishment via seedling herbivory? A test at grassland-shrubland ecotones

Abstract Question: Does shrub invasion at ecotones indirectly limit grass establishment by increasing mammalian seedling herbivory? Location: Chihuahuan Desert, New Mexico, USA. Methods: We tested the hypothesis that herbivore-related mortality of seedlings of the dominant perennial grass Bouteloua eriopoda would be highest in shrub-dominated portions of grassland-shrubland ecotones. We tested the hypothesis in two Chihuahuan Desert sites featuring similar shrub encroachment patterns but different shrub species, grass cover, and different abundances of small mammals. Within each site we transplanted B. eriopoda seedlings to grass-dominated, middle, and shrub-dominated positions of replicate ecotones during the time of year (mid-summer) when they would naturally appear and monitored seedling fates. We estimated population size/activity of putative small mammal herbivores. Results: Seedlings were killed by mammals in greater numbers in shrubland than in grassland or middle ecotone positions at the site with...
Flow dissipation equation in liquid helium II

At high flow rates superfluid helium exhibits dissipation in that a chemical potential gradient is necessary to drive the flow. On the basis of a specific model for the cause of this behavior a detailed relationship between the chemical potential gradient and the resultant flow is derived. Some implications of the theory with regard to recent experiments are discussed.
Symptoms of stress-induced gain degradation in power MESFETs

GaAs metal-semiconductor field effect transistors configured as microwave power amplifiers have been observed to degrade under normal device operations at high gate-to-drain fields. The nature of this degradation is an increase in the gate current, with a subsequent decrease in the gain. We present evidence that crystallographic defects in the active region are responsible for this “power slump” and that these defects originate during device operation due to the high strain fields which exist as the result of passivation layer processing. Strain data and x-ray topographic images support our assertion that passivation layer processing induces high strain in and around the gate-to-drain region of the device. Topographic images show that an increase in dislocation density occurs in the highly stressed regions after power slump. By varying deposition parameters, we can produce passivation films, which induce less stress in the active region, resulting in less dislocation generation and a less severe power slump.
One Program's Experience With the Use of Skype for SOAP

We read with interest Edje and colleagues' article in the September 2013 issue of the Journal of Graduate Medical Education about the use of Skype (Microsoft, Redmond, WA) interviews for residency recruitment, and the suggestion to use Skype during the process of the Supplemental Offer and Acceptance Program (SOAP).1 For our pediatrics residency program, SOAP consisted of a 48-hour block of time to review approximately 600 candidates who applied for a single, unfilled slot. Similar to what Edje et al1 and Shah and colleagues2 have described, we use Skype for interviews during SOAP. Preparation is the key to using Skype for participating in SOAP. Well before Match week, the program must declare its intention to participate in SOAP if the need will arise. A team of individuals knowledgeable about the program must be on standby to forgo other obligations and commit their time to assisting with the process. Our program's 6-member team consisted of the program director, 2 associate program directors, the vice chair of education, the program manager, and a senior resident. The designated institutional official provided oversight. During Match week approximately 120 applications were reviewed within a 28-hour window. Phone and e-mail contact was made with approximately 20 candidates, 13 of whom (65%) were invited to interview via Skype. The 13 candidates were interviewed during an 8-hour period on the Tuesday of Match week, with each interview lasting approximately 30 to 40 minutes. The program director participated in all 13 interviews (100%), and 2 interviews (15%) were conducted solely by the program director. For 3 interviews (23%), program personnel could not see the applicants because of technical difficulties. In all 13 cases (100%), the applicants could see the program representatives. At the conclusion of the process, our program created a SOAP rank list that included all 13 applicants (100%). The unfilled slot was accepted by our No. 1 choice in the first round of SOAP. Every applicant interviewed via Skype expressed overwhelmingly positive comments about the use of that modality. When asked if they had “Skyped” with other programs, all responded “no.” One applicant modified her response to let us know that after she informed another institution's program that our program was going to interview her via Skype, the other institution then invited her for a Skype interview. Program participants also expressed overwhelmingly positive comments about their experience with the Skype interviews. Our experience has led us to recommend the use of Skype in the SOAP process because it is impractical for applicants to travel and physically visit programs in the brief period available for completing SOAP.
Quantitative analysis of simple lipid classes by thin-layer chromatography

Abstract 1. 1. A quantitative thin-layer Chromatographie procedure for the analysis of simple lipid classes (‘neutral lipids’) is described. They were separated by two-step development on silica gel thin-layer chromatoplates. In the first step the solvent diisopropyl ether-acetic acid (96:4, v/v) was used and in the second step, petroleum ether-diethyl ether-acetic acid (90:10:1, v/v/v). 2. 2. After separation, lipid bands were detected by Rhodamine 6G spray, the silica gel with adhered lipids was scraped off and the lipids were eluted. Triglycerides, diglycerides, free fatty acids and hydrocarbons were eluted with diethyl ether, whereas monoglycerides, free cholesterol and cholesteryl esters were eluted by chloroform-methanol (4:1, v/v). The eluates were filtered through sintered glass (‘fine’ porosity) funnels. 3. 3. The eluted lipids were analyzed in the following ways: quantity of triglycerides, diglycerides, monoglycerides and hydrocarbons were determined by quantitative infrared spectrophotometry; free fatty acids by titration; and cholesteryl esters and cholesterol by a standard chemical procedure. 4. 4. The average recovery of individual lipid classes was in the range 98.9–102.0%. 5. 5. Applicability of the procedure for quantitative analyses of tissue lipids is demonstrated on lipid extracted from rat livers.
An expanded transcriptional map of T7 bacteriophage. reading of minor T7 promoter sites in vitro by Escherichia coli RNA polymerase

Transcription of T7 bacteriophage DNA by Escherichia coli RNA polymerase is initiated primarily at a cluster of three promoter sites (A 1 , A 2 , A 3 ) located near the left-hand end of the genome. These sites are utilized preferentially in vitro when purified E. coli RNA polymerase is added to T7 DNA in the presence of the four ribonucleoside triphosphates ( free initiation conditions). In addition, when E. coli RNA polymerase is added to T7 DNA in the absence of nucleoside triphosphates ( prebinding conditions) the enzyme binds preferentially at these sites to form highly stable promoter complexes. However, addition of RNA polymerase in excess of that needed to saturate the A promoter sites leads to binding of enzyme at three or four additional promoter sites (minor promoter sites B, C, D and E). RNA polymerase holoenzyme bound at these sites forms highly stable complexes which are able to initiate RNA chains rapidly when presented with ribonucleoside triphosphates. The minor promoter sites have been located on the T7 genome and correspond to a set of promoter sites identified first by Minkley & Pribnow (1973) in studies of dinucleotideprimed initiation. Comparative studies of the properties of E. coli RNA polymerase bound to major (A 1 ) and minor (C and E) promoters show that the stability of minor promoter complexes to dissociation and to attack by inhibitors can be comparable to those formed at the major promoter site. The transition temperatures for the several promoters are also quite close; thus, RNA polymerase forms “open” promoter complexes at both major and minor promoter sites at 37°C. Therefore, the preferential binding of RNA polymerase to the A 1 promoter is not due to a greater affinity for that region, nor to inability of the enzyme to form open promoter complexes at the minor promoter sites. Studies of the kinetics of site selection confirm that RNA polymerase holoenzyme forms rapidly starting promoter complexes much more rapidly at promoter A 1 than at promoters C and E. However, evidence is found for rapid formation of a complex at promoter C which cannot initiate an RNA chain rapidly. It is suggested that there is rapid formation of an initial “closed” complex at both major and minor promoters, and that discrimination is based on the rate of the melting reaction to form an open complex.
Minorities in the Official Media Determinants of State Attention to Ethnic Minorities in the People's Republic of China

This article documents and provides an explanation for changing levels of government attention to minority populations in the People's Republic of China. Employing a content analysis of People's Da...
Technology for teaching the rest of us

The motivated student is easy to teach. You facilitate learning and get out of the way. It's much more challenging to teach the student who is less motivated, or who needs knowledge to support their main interest. Think of the graphics designer who chooses to learn scripting to make their job easier, but doesn't want to learn to "program" and whose many (simple) mistakes cost valuable time. Think of the secondary-school business teacher who wants to teach computer science, but who doesn't want to learn to be a professional programmer. The number of people who need some knowledge of a domain may be much greater than those who need expertise in that domain. Providing learning opportunities tailored to the needs and interests of the learner, potentially motivating that interest where necessary, is a great and important challenge in an increasingly technological society. My talk will describe characteristics of these challenges and suggest where computing technologies and computing education research insights may provide solutions.
Parallel primal-dual methods for the minimum cost flow problem

In this paper we discuss the parallel asynchronous implementation of the classical primaldual method for solving the linear minimum cost network flow problem. Multiple augmentations and price rises are simultaneously attempted starting from several nodes with possibly outdated price and flow information. The results are then merged asynchronously subject to rather weak compatibility conditions. We show that this algorithm is valid, terminating finitely to an optimal solution. We also present computational results using an Encore MULTIMAX that illustrate the speedup that can be obtained by parallel implementation.
Enhanced tumor targeting by an intratumoral injection of colloidal chromic 32P in two human tumors (AsPC-1 pancreas and Ls174T colon) in nude mice.

Background and Objectives: To find the mechanisms of the ongoing clinical trials in intralesional colloidal chromic 32 P ( 32 P-CP) brachytherapy, the cellular uptake of 32 P-CP, changes in tumor interstitial fluid pressure (TIFP), and tumor blood flow (TBF) using two (AsPC-1, Ls174T) human tumors were measured. Methods: After exposure to 32 P-CP using exponential and plateau-phase cells, cells were trypsinized at various time intervals, then measured for the levels of radioactivity using a γ-counter. Also measured were TIFP using the WIN technique and TBF with laser Doppler flowmetry. Results: The plateau growth-phase of both tumors showed the maximal uptake of 32 P-CP at ∼100 min. TBF decreased within 10 min after an intratumoral (i.t.) injection of 32 P-CP, and reached 75% of control value by 1 h. Conclusions: If 32 P-CP was introduced i.t., it maintained highly efficient tumor targeting, mainly due to two physiological mechanisms: the high adherence of 32 P-CP to the infused regions and the reduction in TBF by this therapeutic colloid.
Crown ether complexes of UO2(NCS)2 and Th(NCS)4: clues to solution behavior or just interesting supramolecular structures?

UO 2 (NCS) 2 and Th(NCS) 4 were prepared in water and then reacted with 18-crown-6 in 3:1 CH 3 CN:CH 3 OH. The crystal structures of three salts were investigated: the mixed hydroxide/thiocyanate salt without crown ether, [UO2(NCS)(OH 2 ) 2 (μ-OH)] 2 , the second sphere complex [UO 2 (NCS) 2 (OH 2 ) 3 ].1,5(18-crown-6).CH 3 CN, and the outer sphere crown ether/inner sphere glycol complex, Th(NCS) 4 (OH 2 )(HOCH 2 CH 2 OH) 2 ].18-crown-6. The outer sphere complexes provide a glimpse into possible solution states which may enhance transfer of actinide salts from a more polar to a less polar medium without direct metal/crown ether complexation. In the solid state, the supramolecular structures derived from intramolecular hydrogen bonding and S...S interactions provide additional information that may be useful in the rational design of actinide solid state complexes via crystal engineering.
Neonatal transection alters the percentage of substance-P-positive trigeminal ganglion cells that contribute axons to the regenerate infraorbital nerve.

Neonatal transection results in a marked reduction of the number of trigeminal (V) ganglion cells that contribute axons to the regenerate infraorbital nerve (ION; Jacquin and Rhoades, 1985; Chiaia et al., 1987). Such lesions also produce a profound deafferentation of the V brain stem complex that appears to spare the innervation of layers I and II of subnucleus caudalis (SpC) by subtance-P-positive (SP-positive) primary afferents (Jacquin and Rhoades, 1985; Rhoades et al., 1988). In the present study, we combined retrograde tracing with immunocytochemistry to determine whether neonatal transection of the ION alters the percentage of SP-positive V ganglion cells that contribute axons to this V branch upon regeneration. In V ganglia ipsilateral to the intact ION (n = 8), 11.6% ± 3.2% of the cells labeled after application of true blue (TB) to the ION were also SP-positive. In ganglia ipsilateral to the neonatally damaged nerve (n = 8), 18.6% ± 4.7% of the cells labeled after application of TB to the regener...
Estrogen sulfotransferase in human placenta.

Human placental estrogen sulfotransferase (ESFT) was partially purified from the term placental cytosol by (NH4)2SO4 precipitation and agarose gel chromatography. Additional purifications caused a rapid loss of the enzyme activity. The activity was abolished by isoelectrofocusing but partially retained by chromatofocusing. The value of pI of human placental ESFT is 5.8 and the same value was obtained for bovine adrenal ESFT. The enzyme protein was able to bind to the affinity resin, estradiol-17-hemisuccinyl-1,2-diaminododecane sepharose 4B, but difficult to be extracted by estradiol (E2). The extract of the affinity resin showed one major protein band at 68,000 dalton on SDS-polyacrylamide gel electrophoresis. Kinetic studies using partially purified ESFT revealed that E2 is the best substrate for this enzyme. The relative rate of sulfurylation of E2 estrone, estriol and dehydroepi-androsterone at 4 μM (Km for E2) is 1, 0.3, 0.08 and 0.08, respectively.
Structure of Annelid High Molecular Weight Hemoglobins (Erythrocruorins)

The extracellular vascular hemoglobins (erythrocruorins) of annelids are polymeric oxygen carriers with molecular weights of approximately 3 × 106 or about 46 times the molecular weight of a vertebrate hemoglobin tetramer. The molecule appears as a dodecamer of 12 large submultiples arranged at the vertices of two regular hexagons one on top of the other in electron micrographs. The dimensions are about 250 A across the face of the hexagon and about 170 A in height. The molecular weight of a one-twelfth submultiple is approximately 250 000. Biochemical studies suggest that each submultiple contains 16 to 18 subunits and that the intact hemoglobin molecule contains approximately 200 subunits. Unlike vertebrate hemoglobin which contains one heme moiety for each polypeptide chain the annelid hemoglobins apparently contain one heme per 15 to 20 chains. The reasons for this lack of a 11 heme chain stoichiometry are not known at present. One possibility may be that it is the result of insufficient purification of the hemoglobin. Alternatively, more than one globin chain might share a heme certain globin chains might lack the heme moiety and have a non hemoglobin function, or certain globin chains may lose their heme during purification of the hemoglobin. We are presently determining the amino acid sequence of one globin chain of Lumbricus terrestris hemoglobin. This information should be helpful in understanding the structure of these interesting polymers.
The effect of transfer factor therapy on tumor immunity in alveolar soft part sarcoma.

Abstract A young man with alveolar soft part sarcoma and his identical twin were studied in terms of immunologic response to the patient's tumor homogenate. The lymphocytes from both twins underwent lymphoblastic transformation to tumor homogenate but only the healthy twin's lymphocytes released demonstrable migration inhibition factor (MIF) to the tumor preparation. Transfer factor was prepared from the healthy twin and administered to the tumor-bearing twin. A total dose of transfer factor equivalent to 45 × 10 8 lymphocytes given in three separate doses produced a persistently positive MIF assay in the patient. The tumor neither regressed nor progressed during the 6-month period after transfer factor therapy.
Review of Latex Allergy

Background: Allergy to latex has become an increasing concern to many patients and health care providers. Health care providers should become aware of this problem and develop strategies for treatment and prevention. Methods: We searched MEDLINE from 1990 to 1998 for the topics of latex allergy using the key words “latex” and “allergy.” Other sources were found from back-referencing these references and from the Internet. Results: Latex allergy is emerging as a clinical and occupational health problem. Understanding the clinical and immunologic features, which range from dermatitis to anaphylaxis, can provide the basis of preventive and therapeutic strategies. Conclusion: The clinician should be able to recognize latex allergy and educate patients about the potential hazards of latex-containing products. Providers can develop a plan for protecting patients and health care staff from latex exposure as well as treating allergic reactions when they occur.
Growth, technology transfer, and the long-run theory of international capital movements

Abstract This paper provides a model of growth and international capital movements. Technology is assumed to be transferred via international capital movements from the developed North to the developing South. It is shown that when the South shifts from autarky to free capital mobility, its steady-state growth rate of per capita income rises. Also, under free capital movements, an increase in the autarkic growth rate of human capital and/or technological diffusion rate in the South, lowers the steady-state income gap between the North and the South.
Behavior of grazing cattle exposed to small populations of stable flies (Stomoxys calcitrans L.)

Abstract Cattle grazing in the presence of low-level infestations of stable flies (Stomoxys calcitrans L.) may offset reductions of grazing time by increasing their rate of herbage intake, and this may contribute to the determination of economic threshold populations. On four consecutive days, we released four pulses of 50 or 100 laboratory-reared stable flies at 15 min intervals over 1 h in screened enclosures, according to a balanced change-over design. Within these enclosures, fasted, adult Angus cows (Bos taurus L.) (body weight (BW) 465 ± 30 kg) grazed vegetative tall fescue (Festuca arundinacea Schreb. cv. ‘Johnstone’) at herbage dry matter (DM) allowances of 1.4 kg (100 kg BW)−1 h−1. Alighted fly numbers on body surfaces of cows were similar during each quarter of grazing meals, and numbers of alighted flies increased linearly as more were released. Cows exposed to colonies of 100 stable flies had 16 alighted on fore legs, 5 on hind legs and 5 on trunks. Stable flies weighed 6.1 mg before and 17.7 mg after feeding. Fly-induced behavior of grazing cows did not vary significantly (p > 0.05) within grazing meals, and releases of up to 100 stable flies caused linear increases in movements of heads (to 3.3 min−1), ears (to 3.7 min−1), skin twitches (to 14 min−1 side−1) and tail swishes (to 36 min−1), but had little effect on movements of fore and hind legs (
Optimum Peak Cycle Pressure for the Intercooled-Supercharged Gas Turbine Engine

Performance (thermal efficiency and mass specific power) of a simple-cycle gas turbine increases monotonically with peak cycle temperatures, for a given peak cycle temperature, the performance also depends on cycle pressure ratio or peak cycle pressure: maximum performance (both mass specific power and thermal efficiency near their maximum values) is achieved in a narrow range of optimum peak cycle pressures.A recently proposed intercooled-supercharged cycle gas turbine differs from the conventional intercooled cycle gas turbine in their intercooler placement. This paper studies the performance of the proposed cycle based on a reformulated intercooling-supercharging optimization procedure. The intercooler placement is defined by a new parameter, the intercooling supercharging parameter. In terms of the intercooling supercharging parameter and the peak cycle pressure, a map of performance curves (efficiency versus specific power) is constructed, which discloses a higher performance zone for the proposed cycle. This performance zone is defined by optimal intercooler placement and peak cycle pressures that are considerably higher than the simple-cycle’s optimum peak cycle pressures. At these higher pressures, the intercooled-supercharged-cycle gas turbine can achieve a new level of performance: a 20% to 30% improvement over the simple cycle in thermal efficiency and mass specific power.Copyright © 1995 by ASME
The Organization of Mechanical Intelligence

*Recommended by Donald G. Paterson, and received for publication by Carl Murchison of the Editorial Board, February 28, 1928. †This work was done as part of a research, the complete data of which are available in a master's thesis in the University of Minnesota Library, under the title “Analysis of Intercorrelations of Mechanical Ability Tests” by Harold D. Carter. The author wishes to acknowledge his indebtedness to Professor Donald G. Paterson of the University of Minnesota, whose inspiration and help were invaluable.
On the Use of a Driven Wedge Test to Acquire Dynamic Fracture Energies of Bonded Beam Specimens

A driven wedge test is used to characterize the mode I fracture resistance of adhesively bonded composite beam specimens over a range of crosshead rates up to 1 m/s. The shorter moment arms (between wedge contact and crack tip) significantly reduce inertial effects and stored energy in the debonded adherends, when compared with conventional means of testing double cantilever beam (DCB) specimens. This permitted collecting an order of magnitude more crack initiation events per specimen than could be obtained with end-loaded DCB specimens bonded with an epoxy exhibiting significant stick-slip behavior. The localized contact of the wedge with the adherends limits the amount of both elastic and kinetic energy, significantly reduces crack advance during slip events, and facilitates higher resolution imaging of the fracture zone with high speed imaging. The method appears to work well under both quasi-static and high rate loading, consistently providing substantially more discrete fracture events for specimens ...
Emergent intensity from a plane-parallel medium exposed to a Gaussian laser beam: A comparison of Rayleigh and isotropic scattering

The focus of this two-dimensional study is the radially varying intensity emergent from a plane-parallel scattering medium exposed to a collimated, Gaussian laser beam directed perpendicular to the upper surface. The method of analysis is the integral transform technique. Specifically, this work uses the generalized reflection and transmission functions from a previous study to construct the emergent intensity with the use of an inverse Hankel transform. Radially varying backscattered and transmitted intensities are calculated for media with isotropic and Rayleigh scattering phase functions and optical thicknesses that range from 0.125 to 8.0. The behavior of the emergent radiation inside and outside the beam is investigated for both narrow and wide beams. A new integration method is implemented to compute the emergent intensity at the beam center. The emergent intensity at the beam center is used to quantify when a one-dimensional model may be used. As expected, for small optical thicknesses and near the beam the phase function has significant influence, while far from the beam multiple scattering reduces the influence of the Rayleigh phase function. Results from this study will be useful in understanding and interpreting more complicated situations, such as those that include polarization.
Conservation form of the Navier-Stokes equations in general nonsteady coordinates

Introduction R interest in the generation of general bodyoriented curvilinear coordinate systems," for the purpose of solving the complete Navier-Stokes system of equations for subsonic and supersonic flows, has given rise to many forms of presentations of the equations both in conservative and nonconservative formulations. Based on the available solutions of the gasdynamic equations (e.g., Ref. 5) the conservation-law form of the equations seems definitely preferable, particularly when shocks are present. Although the above statement cannot be repeated in a definitive sense for the case of viscous subsonic and supersonic flow prediction through the Navier-Stokes equations, nevertheless, it is expected that the conservation-law form may eventually be more acceptable for numerical purposes. The purpose of this paper is to derive the conservation-law form of the Navier-Stokes equations in general nonsteady coordinate systems in a simple and direct fashion. Previous work on this subject has been done by McVittie, Viviand, and Vinokur. It will be shown in this Note that the equations in the conservation-law form can be obtained simply by a little manipulation of some standard vector and tensor formulas.
Teaching Techniques in the Clinical Setting: the Emergency Medicine Perspective

The emergency department (ED) provides a unique educational experience that is distinct from both inpatient and ambulatory care settings. Because of the high acuity, interesting pathology, and rapid patient turnover, the ED is an ideal location to train medical students. Numerous teaching opportunities exist within the domain of the ED. In the preclinical years, the ED setting provides medical students with an introduction to clinical medicine and may serve as a venue for teaching basic history and physical examination skills. In the clinical years, medical students are exposed to a wide range of undifferentiated patients. Besides common medical and surgical complaints, many medical students will encounter clinical scenarios that they otherwise would have little direct contact with. Encounters such as the acutely poisoned or intoxicated patient, environmental emergencies, interaction with out-of-hospital providers, and patients requiring emergency procedures are just a few situations that make emergency medicine a distinct clinical specialty. These and other student–patient encounters can provide the teaching physician an opportunity to focus case-based teaching on a number of elements including complaint-directed medical interviewing and physical examination skills, development of case-specific differential diagnosis, diagnostic evaluation, implementation of patient management plans, and patient disposition. In this review article, the authors discuss various ways to approach and improve clinical teaching of medical students, including: opportunities for teaching in the ED, teaching procedural skills, student case presentations, clinical teaching styles, qualities of an effective clinical teacher, and barriers to effective clinical teaching.
External Beam Irradiation as an Adjunctive Treatment in Failing Dialysis Shunts

PURPOSE To evaluate the utility of low-dose irradiation as adjunctive treatment for failing dialysis shunts related to stenoses. MATERIALS AND METHODS Thirty-one patients with 41 lesions in their dialysis shunts were successfully enrolled for this study. After imaging of the shunt and calculation of venous stenoses, each patient was randomized into one of two segments of the protocol: (i) angioplasty and/or stent placement alone, and (ii) angioplasty and/or stent placement followed by external beam irradiation. All patients with significant venous stenoses (> 50%) were treated with appropriately sized PTA (percutaneous transluminal angioplasty) and Wallstents. Patients randomized to the external irradiation segment underwent localized irradiation via a Theratron cobalt unit of 7 Gy 0–24 hours and 24–48 hours after intervention. Those patients randomized to the control group received no additional treatment. Clinical follow-up included resumption of successful dialysis with appropriate hemodynamic parameters. Two follow-up shunt images were obtained, follow-up 1 (fu-1) from 90 to 179 days and follow-up 2 (fu-2) from 180 to 365 days. Percentages of significant recurrent stenoses, defined as greater than 50%, were recorded and re-treated as needed. RESULTS Sixteen of the 31 patients underwent external beam irradiation. There were 21 lesions in the test group that underwent irradiation after intervention, and 20 lesions were treated with intervention alone. There were seven native arteriovenous fistulas and 24 Gore-tex grafts. All stenoses were either venous outflow stenoses (68%) or central stenoses (32%). The authors utilized χ 2 analysis to compare restenoses rates between the control and irradiated groups at fu-1 ( P P CONCLUSIONS Although the results show that external beam irradiation has minimal effects on the restenoses of dialysis grafts when used in conjunction with PTA and stent placement, further studies with a larger, more homogenous population are needed to assess the trend of improving patency rates after external beam irradiation.
Fundamental Challenges in Mechanistic Enzymology: Progress toward Understanding the Rate Enhancements of Enzymes

Enzymes are remarkable catalysts that lie at the heart of biology, accelerating chemical reactions to an astounding extent with extraordinary specificity. Enormous progress in understanding the chemical basis of enzymatic transformations and the basic mechanisms underlying rate enhancements over the past decades is apparent. Nevertheless, it has been difficult to achieve a quantitative understanding of how the underlying mechanisms account for the energetics of catalysis, because of the complexity of enzyme systems and the absence of underlying energetic additivity. We review case studies from our own work that illustrate the power of precisely defined and clearly articulated questions when dealing with such complex and multifaceted systems, and we also use this approach to evaluate our current ability to design enzymes. We close by highlighting a series of questions that help frame some of what remains to be understood, and we encourage the reader to define additional questions and directions that will deepen and broaden our understanding of enzymes and their catalysis.
Stress development at the cement paste-steel interface for thin cement paste coatings

Abstract A novel technique for determining the development of stress at the steel-cement interface for thin cement paste coatings is briefly described. A series of interfacial stress-hydration time curves are presented for three matrix systems: cement + silica fume, cement + calcium carbonate, and tricalcium aluminate + gypsum. Results are discussed in terms of possible mechanisms of stress development.
Nature Of Defects And Defect Generation In Optical Glasses

The natures of radiation-induced defects and defect generation processes in optical glasses are critically reviewed. Materials of interest here include silica, silicates, and fluorides, hence encompassing glasses now in use or contemplated for fiber optics, lenses, mirrors, windows, and other optical applications. The most extensive discussions are devoted to pure fused silica because of its wide application and extensive literature and its value as a simple prototype for beginning to understand more complex systems. Emphasis is placed on the atomic scale structure of point defects, as gleaned mainly from the technique of electron spin resonance, although such important properties as optical absorption, luminescence, and volume change are also discussed.
Modulated parasystole originating in the sinoatrial node.

A computer model of "modulated sinus parasystole" was devised in which two sinus pacemakers interacted electrotonically, entraining each other's periodicity according to their beat-to-beat phasic relationships. Depending on the preestablished rules, the model gave rise to various rhythm patterns that were similar to those recorded in patients with sinoatrial arrhythmias. The validity of the model in predicting clinically observed rhythm disturbances was tested in a case of sinoatrial extrasystolic activity. The sinoatrial origin of parasystolic discharges giving rise to various patterns of group beating in this case was diagnosed according to the following electrocardiographic criteria: premature P waves having contour identical to P waves of basic beats, variable coupling intervals, and absence of compensatory pauses (i.e., returning cycles having duration similar to that of the basic P-P interval). For the analysis, it was assumed that two distinct but closely apposed sinoatrial pacemaker centers were competing for activation of the heart. The model accurately simulated the arrhythmias in the electrocardiographic trace. The best fit was found when the two pacemakers interacted on the basis of "resetting" in one direction and electronic modulation in the other. In fact, under appropriate conditions, the model matched precisely all frequency-dependent patterns of extrasystolic activity observed in the trace. We conclude that the modulated parasystole hypothesis can readily explain the mechanism of sinus extrasystolic discharges whose returning cycle equals the basic P-P interval. Moreover, the model predicts that, when the rules for mutual entrainment between "dominant" and parasystolic sinus pacemaker are appropriate, the returning cycle can be shorter than the basic cycle.
A Double Outflow from a Deeply Embedded Source in Cepheus

We report near-infrared and submillimeter line and continuum measurements toward the embedded source IRAS 23011+6126 in the Cepheus E molecular cloud. The source has a luminosity of 70 ± 10 L☉ and is not detected in the 2 μm continuum. Its spectral energy distribution is characterized by a very low bolometric temperature (Tbol = 60 K), placing it in the class 0 category. The source is associated with a relatively compact (0.18 pc) molecular cloud core with a mass of 8 M☉. Also associated with this source are four lobes of outflowing molecular gas. These lobes can easily be grouped into two well-collimated bipolar outflow structures with position angles differing by 52°. The small-scale outflow structure is associated with strong line emission from vibrationally excited molecular hydrogen with line ratios consistent with C shocks, while the large-scale outflow structure shows no associated molecular hydrogen emission. If one source is responsible for both flows, then the outflow mechanism must be both temporally and angularly variable. An alternate possibility is that the observed luminosity and outflow structures are generated by two sources, separated by less than 104 AU on the sky. Both of these sources must be very deeply embedded, and presumably quite young.
Spondylometaphyseal dysplasia in mice carrying a dominant negative mutation in a matrix protein specific for cartilage-to-bone transition

The vertebrate skeleton is formed primarily by endochondral ossification, starting during embryogenesis when cartilage anlagens develop central regions of hypertrophic cartilage which are replaced by bony trabeculae and bone marrow. During this process chondrocytes express a unique matrix molecule, type X collagen. We report here that mice carrying a mutated collagen X transgene develop skeletal deformities including compression of hypertrophic growth plate cartilage and a decrease in newly formed bone, as well as leukocyte deficiency in bone marrow, reduction in size of thymus and spleen, and lymphopenia. The defects indicate that collagen X is required for normal skeletal morphogenesis and suggest that mutations in COL10A1 are responsible for certain human chondrodysplasias, such as spondylometaphyseal dysplasias and metaphyseal chondrodysplasias.