cssi/SciSciGPT-SciSciNet huggingface dataset:
Comparative Effectiveness of Beta-Adrenergic Antagonists (Atenolol, Metoprolol Tartrate, Carvedilol) on the Risk of Rehospitalization in Adults With Heart Failure

Placebo-controlled randomized trials have demonstrated the efficacy of selected β blockers on outcomes in chronic heart failure (HF), but the relative effectiveness of different β blockers in usual clinical care is poorly understood. We compared 12-month risk of rehospitalization for HF associated with receipt of different β blockers in 7,883 adults hospitalized for HF within 2 large health plans between January 1, 2001 and December 31, 2002. Beta-blocker use was ascertained from electronic pharmacy databases and readmissions within 12 months were identified from hospital discharge databases. Extended Cox regression was used to examine the association between receipt of different β blockers and risk of readmission for HF after adjustment for potential confounders. During follow-up, there were 3,234 person-years of exposure to β blockers (39.3% atenolol, 42.0% metoprolol tartrate, 12.3% carvedilol, and 6.4% other). Crude 12-month rates of readmissions for HF were high overall (42.6 per 100 person-years). After adjustment for potential confounders, cumulative exposure to each β blocker, and propensity to receive carvedilol compared with atenolol, adjusted risks of readmission were not significantly different for metoprolol tartrate (adjusted hazard ratio 0.95, 95% confidence interval 0.85 to 1.05) or for carvedilol (adjusted hazard ratio 0.92, 95% confidence interval 0.74 to 1.14). In conclusion, in a contemporary cohort of high-risk patients hospitalized with HF, we found that adjusted risks of rehospitalization for HF within 12 months were not significantly different in patients receiving atenolol, shorter-acting metoprolol tartrate, or carvedilol.
Surgical Stress in the Healthy Elderly

Surgery has sometimes been studied as a stressful event. The aim here was to determine the relationship between degrees of anxiety before surgery and postoperative outcomes in healthy old and young men. Old and young men were selected if they had no illnesses or prior surgery and were scheduled for elective hernia repair. Levels of anxiety were measured preoperatively along with other physiologic, psychologic, and immunologic modalities. Operative data and follow-up data for 30 days were obtained. Old and young men did not differ significantly before surgery. When age groups were divided by preoperative anxiety and their postoperative outcomes compared, more anxiety was associated with more pain-relieving medications and more disability days in each age group. Furthermore, the old anxious had even more disability days and complications than did other groups. The study points to the need to prepare the old, even those essentially in very good health, for even a minor surgical stress in order to improve their overall health outcomes.
Synaptic Vesicles Interchange Their Membrane Proteins with a Large Surface Reservoir during Recycling

During recycling of synaptic vesicles (SVs), the retrieval machinery faces the challenge of recapturing SV proteins in a timely and precise manner. The significant dilution factor that would result from equilibration of vesicle proteins with the much larger cell surface would make recapture by diffusional encounter with the endocytic retrieval machinery unlikely. If SV proteins exchanged with counterparts residing at steady state on the cell surface, the dilution problem would be largely avoided. In this scenario, during electrical activity, endocytosis would be driven by the concentration of a pre-existing pool of SVs residing on the axonal or synaptic surface rather than the heavily diluted postfusion vesicular pool. Using both live cell imaging of endogenous synaptotagmin Ia (sytIa) as well as pHluorin-tagged sytIa and VAMP-2, we show here that synaptic vesicle proteins interchange with a large pool on the cell axonal surface whose concentration is approximately 10-fold lower than that in SVs.
Magnesium and Potassium Inter-relationships in Cardiac Disorders

Magnesium and potassium are the 2 major intracellular cations. The intracellular concentrations of these 2 ions appear to be closely correlated, but the existence of a relationship between the plasma concentrations of these ions has been controversial. A major function of potassium is to maintain the excitability of nerve and muscle tissue. Alterations in either the intracellular or extracellular potassium concentration affect membrane excitability by alterations in the resting membrane potential. The critical factor is not the actual potassium concentration in either compartment but rather the ratio of the intracellular to the extracellular concentration. The intracellular concentration of potassium is maintained against an electrochemical gradient by active transport involving an ionic pump mechanism. In this metabolically active ion-pump mechanism the inward transport of potassium is balanced by the outward transport of sodium; this active transport mechanism involves magnesium. The plasma concentration of potassium has been reported to be an important factor in the genesis of cardiac arrhythmias. The arrhythmogenic mechanisms of hypokalaemia, particularly in mild degrees, have not been clearly defined. However, evidence has begun to accumulate that magnesium deficiency may be a critical factor in the cardiac arrhythmias associated with hypokalaemia. Diuretic drugs are recognised as primary agents in the treatment of essential hypertension. In patients on antihypertensive treatment evidence has recently been reported that there is a link between the administration of diuretics and sudden death. In addition to their action on the renal tubular handling of sodium and water, diuretic drugs affect the renal tubular handling of other ions. A well-established complication of therapy with diuretic drugs is an increased urinary excretion of potassium resulting in hypokalaemia. Hypokalaemia and hypomagnesaemia can be induced by the same mechanisms and are often clinically correlated with one another. The reported incidence of hypomagnesaemia is greater than that of hypokalaemia; a significant correlation also appears to exist between the plasma concentrations of magnesium and potassium. A significant inter-relationship between the plasma concentrations of magnesium and potassium and the evidence for a critical role of magnesium in the genesis of cardiac arrhythmias would support the proposal that magnesium should be routinely measured in situations, such as diuretic therapy, that are potentially associated with hypokalaemia.(ABSTRACT TRUNCATED AT 400 WORDS)
Adaptive Tuning of Numerical Weather Prediction Models: Randomized GCV in Three- and Four-Dimensional Data Assimilation

Abstract In variational data assimilation, optimal ingestion of the observational data, and optimal use of prior physical and statistical information involve the choice of numerous weighting, smoothing, and tuning parameters that control the filtering and merging of diverse sources of information. Generally these weights must be obtained from a partial and imperfect understanding of various sources of errors and are frequently chosen by a combination of historical information, physical reasoning, and trial and error. Generalized cross validation (GCV) has long been one of the methods of choice for choosing certain tuning, smoothing, regularization parameters in ill-posed inverse problems, smoothing, and filtering problems. In theory, it is well suited for the adaptive choice of certain parameters that occur in variational objective analysis and for data assimilation problems that are mathematically equivalent to variational problems. The main drawback of the use of GCV in data assimilation problems was th...
The 12 Mile Creek Site: A Reinvestigation

The 12 Mile Creek site in western Kansas was the first site yielding a fluted projectile point to be excavated in North America by scientific personnel. The Bison from this kill site were used in forming the original concept of B. occidentalis . A new study of the site including radiocarbon dates and a pollen analysis suggests the kill took place in a pine parkland about 10,300 years ago. The artifact from this site reported by Williston seems to be a Clovis projectile point.
RhoScope: A highly portable computer program for visualization of the zero-flux atomic surfaces

Atomic boundaries are defined within the topological theory of atoms in molecules as zero-flux surfaces in the gradient of electron density. The so-defined atomic surfaces often have quite complicated shapes that reflect the local characteristics of the electron distribution. A highly portable computer visualization program, called RhoScope, that displays the zero-flux atomic surfaces is described in this article. Examples of atomic surfaces in the C60 cluster and the C2H2LiCl carbenoid, rendered with the help of RhoScope, are presented.
Evaluation of Mathematical Models for Diffusion from Semisolids

Models used in the description of diffusion processes were applied to drug release from semisolids. Two models, an exponential model for finite systems and a nonexponential model for semi-infinite and infinite systems, are evaluated for their suitability in describing literature data for release of substances from semisolids. The regression lines calculated for these data are evaluated using analysis of variance and examination of residuals. Evaluation of these models using these data indicates that the exponential model derived for finite systems is applicable in all the literature cases while the nonexponential model has restricted applicability.
Congenital obstruction of the alimentary tract

Summary Eight cases of congenital obstruction of the alimentary tract are reported. 1. Congenital esophageal atresia with communication between the upper segment of the esophagus and the trachea. 2. Congenital esophageal atresia with probable communication between the lower segment and the trachea. 3. Partial atresia of the esophagus with narrowing of the lower one-third. The characteristic symptoms of atresia of the esophagus are immediate regurgitation with almost the first mouthful, and constant dribbling of mucus. There may or may not be violent coughing after feeding, with cyanosis. 4. Case of partial atresia of distal end of duodenum. Duodenal obstruction is to be differentiated from pyloric stenosis. The presence of bile in the vomitus, and x-ray examination with barium feeding will aid in the diagnosis. 5. A successful operative result of congenital obstruction of the ileum. 6, 7. Incomplete and complete obstruction, respectively, of the colon. 8. Obstruction due to volvulus with symptoms immediately after birth. It is interesting to note that of the eight cases reported seven were males. The symptoms of congenital intestinal obstruction are characterized clinically by persistent vomiting, distention, constipation or mucous stools stained with blood, anuria, and progressive loss of weight. Although congenital obstruction is very rare, it should be kept in mind whenever a newborn baby vomits. It is obviously important to recognize these cases early because operative intervention is the only treatment, however unsuccessful the results may be, or have been in the past.
Cavitation dosimetry: estimates for single bubbles in a rotating-tube exposure system.

Abstract Cell lysis and hydrogen peroxide production from cavitation in a 60 rpm rotating-tube exposure system were observed for 2.17 MHz ultrasound at 0.8 MPa peak negative pressure amplitude. Synchronized 10 ms burst mode exposure was utilized to emphasize the phenomenon of bubble cycling each half rotation. Low cell numbers and inhibition of H 2 O 2 -consuming enzymes allowed measurement of the residual hydrogen peroxide in exposed cell suspensions. Canine red blood cells (RBCs) or Chinese hamster ovary cells (CHO) suspended at 1–10 6 mL −1 in phosphate buffered saline were lysed exponentially with the number of bursts. The CHO cells were lysed faster than RBCs. The H 2 O 2 increased approximately in proportion to the number of bursts. Longer bursts (100 ms) or continuous exposure produced similar trends, but were less effective per unit of total on-time. The number of bubbles per 10 ms burst was estimated from a simple model to be about 7100. The faster lysis of the CHO cells could be explained mostly by the larger size of these cells, which makes them more likely to meet a bubble. The H 2 O 2 production gave concentrations of about 93–155 eM per bubble per burst. Similar calculations gave estimates of 178 fM per bubble for 100 ms bursts and 150 fM per bubble for continuous exposure. The rate of H 2 O 2 production was roughly 500 fmole s −1 while a bubble crossed the tube. This sonochemical yield could be biologically significant under favorable circumstances.
Reproductive success of screech owls fed Aroclor 1248.

Aroclor® 1248 was fed to captive screech owls (Otus asio) at the rate of three ppm in the diet to determine if reproductive effects such as fewer eggs per clutch, lower hatchability, malformation of the chicks, or higher mortality rates of chicks would appear in this raptorial species as they did in chickens. There were no effects on eggshell thickness, number of eggs laid, young hatched, and young fledged from feeding a low level of Aroclor® 1248 to captive screech owls. The polychlorinated biphenyl (PCB) residues found in the eggs of the dosed birds ranged from 3.9 ppm to 17.8 ppm. Background PCB residues in the diet of all experimental birds ranged from non-detected to 0.62 ppm.
Structure—Activity Considerations in Kinetics and Mechanism of Chlorine Exchange Between Chloramine‐T and Secondary Amines

Abstract To study the mechanism of N -chlorination of secondary amines by chloramine‐T, the kinetics of the reactions of some aromatic-substituted analogues of N -chlorobenzenesulfonamide with various secondary amines were determined. The importance of amine basicity and reactivity of the N–Cl bond of the N -chlorobenzenesulfonamide was also assessed. The results indicate that a mechanism involving the un-ionized species of both reactants (i.e., a molecular mechanism), rather than an ionic mechanism, is operating and that the reaction most likely proceeds via a six-membered-ring transition state that incorporates a water molecule.
Localized oscillator expansions of nuclear two-body wave functions

Abstract Harmonic oscillator expansions are applied to two-body systems simulating the deuteron, triton and alpha particle. Convergence rates in energies and wave functions can be significantly improved when the expansions are localized by first subtracting an approximate asymptotic wave function.
Model checking in Tobit regression via nonparametric smoothing

This paper proposes a class of lack-of-fit tests for checking the adequacy of a presumed parametric form of the regression function in Tobit regression models. This class of tests is a weighted adaptation of the Zheng's test for fitting a parametric regression model. The asymptotic null distributions of the underlying test statistics are shown to be normal. Moreover, the consistency of these tests against some fixed alternatives and asymptotic power against some local nonparametric alternatives are also derived. An optimal test within the proposed class of tests against a given sequence of nonparametric local alternatives is identified. A finite sample simulation shows some superiority of some of the proposed tests, compared to some of the existing tests.
Distinguishing Informational Cascades from Herd Behavior in the Laboratory

This paper reports an experimental test of how individuals learn from the behavior of others. By using techniques only available in the laboratory, we elicit subjects’ beliefs. This allows us to distinguish informational cascades from herd behavior. By adding a setup with continuous signal and discrete action, we enrich the ball-and-urn observational learning experiments paradigm of Anderson and Holt (1997). We attempt to understand subjects’ behavior by estimating a model that allows for the possibility of errors in earlier decisions. (JEL C92, D8).
Pyrene-functionalized oligonucleotides and locked nucleic acids (LNAs): Tools for fundamental research, diagnostics, and nanotechnology

Pyrene-functionalized oligonucleotides (PFOs) are increasingly explored as tools in fundamental research, diagnostics and nanotechnology. Their popularity is linked to the ability of pyrenes to function as polarity-sensitive and quenchable fluorophores, excimer-generating units, aromatic stacking moieties and nucleic acid duplex intercalators. These characteristics have enabled development of PFOs for detection of complementary DNA/RNA targets, discrimination of single nucleotide polymorphisms (SNPs), and generation of π-arrays on nucleic acid scaffolds. This critical review will highlight the physical properties and applications of PFOs that are likely to provide high degree of positional control of the chromophore in nucleic acid complexes. Particular emphasis will be placed on pyrene-functionalized Locked Nucleic Acids (LNAs) since these materials display interesting properties such as fluorescence quantum yields approaching unity and recognition of mixed-sequence double stranded DNA (144 references).
Simplicial cones and the existence of shape-preserving cyclic operators

Abstract Let X denote a real Banach space, X* its dual space and V an n-dimensional subspace of X. Given a weak*-closed cone S*⊂X*, we say that f∈X has shape if 〈f,φ〉⩾0 for all φ∈S*. Let S⊂X denote the cone of elements having shape. Suppose the linear operator P :V→V leaves S invariant (i.e., P (S∩V)⊂S ). We seek extensions P of P to X that leave S invariant; i.e. P:X→V such that P | V = P and PS⊂S. We say that such an extension is shape-preserving. It is shown in Chalmers and Prophet [Rocky Mountain J. Math. 28 (1998) (3) 813] that, under certain conditions on S*, P =I n admits a shape-preserving extension if and only if S*|V is simplicial. In this paper we characterize those operators P for which it is necessary and sufficient that S*|V be simplicial in order to admit a shape-preserving extension. This characterization involves the eigenstructure of P .
Effects of chronic treatment with LH-FSH-RH in hypophysectomized pituitary-grafted male rats.

The effect of a prolonged treatment with LH/FSH—RH was studied in long—term hypophysectomized male rats bearing pituitary grafts under the kidney capsule. LH/FSH—RH was injected twice a day in 1.5% gelatin solution and control rats were injected with the vehicle alone. Two months later the animals were sacrificed. Control rats showed marked regression of spermatogenesis and only prolactin cells seemed to be active when electron microscopic observations of the pituitary grafts were made. Detectable serum FSH and LH levels were present, however, in these animals. The rats injected with LH/FSHRH showed a striking stimulation of spermatogenesis, with complete spermiogenesis in some cases. Electron microscopy of the pituitary grafts showed a predominance of prolactin cells and FSH gonadotrophs; the latter appeared to be functionally active, in contrast to the FSH cells of control grafts. The LH gonadotrophs showed variable numbers of secretory granules, but, in general, these cells were smaller than those of n...
Space-related composite-material experiments

The preparation of composites in space depends on the immersion of reinforcements in a liquid-metal matrix and their uniform, stable dispersion in the bulk products until solidification occurs. The chief problem in achieving the composite is associated with the “wetting” of the reinforcements. A study of the theory of wetting revealed that wetting is prevented by the presence of gaseous and oxide contaminants at the interface between the pure liquid and pure solid. Experiment then confirmed that the use of a vacuum environment, cleaning of all surfaces, elevated temperature, ion bombardment, and vigorous mechanical agitation enabled the immersion and dispersion of candidate reinforcements. The technique is limited by the increased tendency for reaction if the time at elevated temperature is extended.
Solubilization and partial purification of the rabbit parotid Na/K/Cl-dependent bumetanide binding site.

We demonstrate that the high affinity bumetanide binding site of the rabbit parotid acinar cell can be extracted from a basolateral membrane fraction using relatively low concentrations (0.07%, wt/vol; 1 mg membrane protein/ml) of the nonionic detergent Triton X-100. This extracted site cannot be sedimented by ultracentrifugation at 100,000 ×g × 1 hr. Bumetanide binding to this site retains the ionic characteristics of bumetanide binding to native membranes but shows a fivefold increase in binding affinity (Kd=0.57±0.15 μmvs.Kd=3.3±0.7 μm for native membranes). Inactivation of the extracted bumetanide binding site observed at detergent/protein ratios>1 can be prevented or (partially) reversed by the addition of exogenous lipid (0.2% soybean phosphatidylcholine). When the 0.07% Triton extract is fractionated by sucrose density gradient centrifugation in 0.24% Triton X-100, 0.2% exogenous lipid and 200mm salt, the high affinity bumetanide binding site sediments as a single band withS20,w=8.8±0.8 S. This corresponds to a molecular weight ∼200 kDa for the bumetanide binding protein-detergent-lipid complex and represents a sevenfold purification of this site relative to the starting membrane fraction. In contrast to previous attempts to purify Na/K/Cl cotransport proteins and their associated bumetanide binding sites, the present method avoids harsh detergent treatment as well as direct covalent modification (inactivation) of the transporter itself. As a consequence, one can follow the still active protein through a series of extraction and purification steps by directly monitoring its bumetanide binding properties.
Concerning biological effects of spark-decomposed SF6

Sulphur hexafluoride (SF/sub 6/) is used as an insulating gas for electrical applications (gas-insulated substations, switchgear etc.). The gas is inert chemically and innocuous biologically. Electrical discharges (arcs, sparks, corona) in SF/sub 6/ can produce chemical decomposition of the gas. Analysis by mass spectroscopy at the Oak Ridge National Laboratory, Tennessee, USA, has found that discharge of electrical sparks in SF/sub 6/ can produce a wide variety of decomposition products depending on electrode composition, moisture content, presence of oxygen etc. The compounds SOF/sub 2/, SOF/sub 4/, SO/sub 2/F/sub 2/, SiF/sub 4/, SO/sub 2/, HF, SF/sub 4/ and S/sub 2/F/sub 10/ have been identified and quantified in laboratory samples of spark-decomposed SF/sub 6/. Toxicity information on most of these chemicals is sparse, but available data suggest some may have a strong, concentration-dependent biological toxicity. Analysis of the ability of these individual chemicals to cause cell lethality in cultured cell assays has allowed a toxicity ranking for these compounds, and an understanding of which compounds contribute most to cellular toxicity in the cell culture assays. Based on the authors' own experiments and other observations, certain recommendations regarding worker safety in utility applications can be made. >
RNA metabolism in regions of mouse brain during spatial reversal learning.

Abstract The incorporation of cytidine into total RNA in six regions of the brain was assayed in mice during three behavioral treatments. Following the injection of 3 H-cytidine, reversal mice were trained to reverse repeatedly their side preference in a Y-maze for water reinforcement during a 60 min session. Nonreversal mice were reinforced for choosing the previously correct alley during 60 min. Quiet mice were kept isolated after the injection. Only small increases in the incorporation of precursor into RNA were observed. Incorporation of 3 H-cytidine was not altered in the hippocampi of reversal mice. These findings suggest that previously reported elevations of the incorporation of cytidine into hippocampal RNA during spatial reversal training may not be general across species or may depend upon special experimental conditions.
N-Terminal LQT2 Nonsense Mutations Cause a Dominant-Negative Destabilization of WT hERG Subunits

Familial mutations in hERG, the Human Ether-a-go-go Related Gene, disrupt cardiac IKr, leading to Type 2 Long QT Syndrome and potentially fatal ventricular arrhythmias. Of the more than 200 mutations identified to date, eight are nonsense mutations in the hERG 1a amino terminus (NT). How these mutations cause disease is unknown. We found that constructs corresponding to six of these LQT2-linked mutations encoded stable, truncated NT fragments when expressed in HEK cells. We coexpressed these fragments with WT hERG 1a and 1b subunits to mimic heterozygous expression in LQT2 patients and assessed their effects on WT hERG trafficking and expression levels. Western blots revealed that the polypeptides significantly decreased WT 1a and 1b protein expression levels. We hypothesized N-N terminal interactions may mediate the observed reduction and indeed found levels of N-deleted hERG 1a subunit (N-del) were unaffected by the LQT2 polypeptides. Surprisingly, the LQT2 fragments promoted 1a N-del maturation. This indicates the polypeptides are not inherently misfolded and can rescue 1a N-del trafficking, possibly by interacting with downstream regions of the subunit. Reduction of WT protein levels by LQT2 polypeptides therefore requires an intact N-terminus. To determine if the LQT2 polypeptides destabilize WT subunits, we blocked protein synthesis using cycloheximide and tracked WT protein levels over time. Co-expression with LQT2 polypeptides caused a rapid loss of both immature and mature hERG 1a and 1b compared with control indicating accelerated degradation in the ER. In summary, this study demonstrates a novel disease mechanism in which LQT2-linked nonsense mutations in the hERG 1a N-terminus act in a dominant-negative manner by destabilizing ER-resident WT subunits.Support: HL081780 (GAR) and AHA predoctoral fellowship and T32HL007936 (ECRR).
Investigations on black fly vectors (Diptera: Simuliidae) of Leucocytozoon smithi (Sporozoa: Leucocytozoidae) in Florida.

Field and laboratory investigations were conducted during 1975 and 1976 to determine which black fly species transmitted Leucocytozoon smithi to turkeys in Florida. Potential vectors were netted, aspirated from domestic turkeys exposed in the field, collected in Manitoba traps, and captured in turkey-baited blackout box and ramp-type traps. Transmission trials conducted in the laboratory involved both container-reared and wild-caught black flies, and turkeys with both naturally and laboratory-acquired L. smithi infections. Three black fly species ( Simiilium slossonae, S. congareenarum , and S. meridionale ) were incriminated as vectors of L. smithi to turkeys in Florida; field observations and laboratory trials showed that S. slossonae is the primary vector.
A New Necessary Condition of Optimality for Singular Control Problems

Optimality condition for singular control problems derived using differential dynamic programming to obtain expression for change in cost produced by control variation
Changes in concentrations of selenium and mercury in largemouth bass following elimination of fly ash discharge to a quarry.

Abstract Elimination of slurried fly ash discharges to a water-filled quarry was followed by a steady increase in concentrations of mercury in the axial muscle of resident largemouth bass ( Micropterus salmoides ). Average mercury concentrations in bass (adjusted for covariance with fish weight) increased from 0.02 μg/g to 0.17 μg/g in three years. Aqueous selenium concentrations in the quarry decreased from 25 μg/L to μ g/L after elimination of fly ash discharges, but selenium concentrations in bass remained about three times background levels. Previous studies have shown selenium addition to be a viable means of ameliorating mercury contamination in fish in low alkalinity, low pH waters of northern Europe and Canada. These results suggest that selenium may also be effective at blocking the accumulation of methylmercury in harder, more alkaline waters.
Synthesis of Polyketides via Diastereoselective Acetalization

Diastereoselective acetalization of pseudo-C2-symmetric 1,3,5-triol systems is a general strategy for the rapid generation of polyketides. The oxidative acetalization reaction shown above was studied under both kinetic and thermodynamic conditions, using synthetic 1,3,5-triol units. In addition, all possible stereochemical variants of a 1,3,5-triol system were prepared from the corresponding acetal to expand the synthetic versatility of this method.
Cervical dilatation in interval insertion of an IUD Who requires it and does it lead to a high explulsion rate

Cervical dilatation is occasionally performed to facilitate IUD insertions in difficult-to-insert cases. Patient characteristics associated with the need for dilation and whether dilation is associated with an increased risk of early expulsion of the IUD have rarely been studied. This analysis, using the extensive international IUD data base developed and maintained by Family Health International, is intended to answer these questions. This case-control analysis revealed that nulliparous women as well as women who had used oral contraceptives or an IUD in the previous month were more likely to require cervical dilatation at IUD insertion. Breastfeeding women, on the other hand, were less likely to require cervical dilatation to facilitate IUD insertion. Hypotheses are generated from this analysis that need to be tested in future studies. The six- and 12-month gross cumulative life-table expulsion rates and other pertinent termination event rates (e.g., accidental pregnancies and removals due to bleeding and pain) were not found to be higher for women with cervical dilatation than for women without.
An adenovirus, FAV-1, isolated from the kidney of a frog (Rana pipiens).

Abstract An adenovirus-like cytopathic agent, designated frog adenovirus 1 (FAV-1), was recovered from turtle (TH-1) cell cultures inoculated with cells of a granuloma-bearing kidney of a leopard frog, Rana pipiens . Virus replication, as indicated by cytopathic effect (including intranuclear inclusions) was limited to TH-1 cells; a variety of other cell types from amphibians, reptiles, fish, and mammals, were refractory to infection. The optimal temperature for replication was 30 C. Electron microscopic examination of infected TH-1 cells revealed intranuclear virus particles exhibiting a size and ultrastructure characteristic of adenoviruses. The virus is ether-resistant and a DNA nucleic acid type was inferred from observations of inhibition by 5-bromo-2′-deoxyuridine. The virus does not possess the group-specific, complement-fixing antigen of mammalian adenoviruses, and was not neutralized by hyperimmune antisera to the avian adenoviruses CELO, and GAL types I, II, and III. FAV-1 did not cause tumors when inoculated into the nephrogenic ridge of R. pipiens tadpoles. FAV-1 appears to be an “orphan” virus, and the first described adenovirus from a poikilothermic vertebrate host.
On bidirectional English-Arabic search

In Cross-Language Information Retrieval (CLIR), queries in one language retrieve relevant documents in other languages. Machine-Readable Dictionaries (MRD) and Machine Translation (MT) systems are important resources for query translation in CLIR. We investigate the use of MT systems and MRD to Arabic-English and English-Arabic CLIR. The translation ambiguity associated with these resources is the key problem. We present three methods of query translation using a bilingual dictionary for Arabic-English CLIR. First, we present the Every-Match (EM) method. This method yields ambiguous translations because many extraneous terms are added to the original query. To disambiguate query translation, we present the First-Match (FM) method that considers the first match in the dictionary as the candidate term. Finally, we present the Two-Phase (TP) method. We show that good retrieval effectiveness can be achieved without complex resources using the Two-Phase method for Arabic-English CLIR. We also empirically evaluate the effectiveness of the Arabic-English MT approach using short, medium, and long queries of TREC7 and TREC9 topics and collections. The effects of the query length to the quality of the MT-based CLIR are investigated. English-Arabic CLIR is evaluated via MRD and English-Arabic MT. The query expansion via post-translation approach is used to deemphasize the extraneous terms introduced by the MRD and MT for English-Arabic CLIR.
Bartók's Pozsony: An Examination of Neglected Primary Sources

While Bela Bartok's Selbstbiographie of 1921 provides some insight into his musical training in Pozsony, music historians looking for a broader understanding of the rich musical life that helped shape Bartok must also consider autobiographical statements made by his contemporaries. Fortunately, excellent opportunities present themselves in the writings of the two musicians who preceded Bartok as the organist for the Pozsony Gymnasium's Sunday Mass: Franz Schmidt's Autobiographische Skizze, which he completed around 1915, and Ernő Dohnanyi's Memoirs, which he read over Hungarian Radio on January 30, 1944. This article examines the three autobiographical statements to provide a more accurate representation of the richness of Pozsony's musical life at the end of the nineteenth century, and a more complete portrayal of the musical and cultural influences under which Bartok thrived in Pozsony.
Breast Cancer Detection

In the article “Dr. Quinn counsels the House” (Random Samples, 5 Mar. p. 1445), it is reported that actress Jane Seymour suggested that women opt for thermography before mammograms, which “are now known to be causing cancer.” This statement was made during a hearing on alternative health care before the Committee on Government Reform in the U.S. House of Representatives. This statement may have serious repercussions for women's health. First, it may frighten and discourage women from having regular screening mammography. Second, the Food and Drug Administration has not approved thermography equipment for screening purposes. A high-quality mammogram is the most effective way to detect breast cancer early (even before it can be felt), when it is most treatable. Studies show that regular screening mammograms can help decrease the chance of dying from breast cancer. Finding a breast tumor early may mean that a woman can choose surgery that saves her breast. Also, she may not have to undergo chemotherapy. While many people are worried about exposure to x-rays over time, the low amount of radiation used for mammograms does not significantly increase the risk for breast cancer. The Mammography Quality Standards Act (MQSA), passed by Congress in 1992, set a maximum radiation dose limit that is acceptable. Under MQSA, all of the nation's mammography facilities receive an annual inspection. The inspection data show that radiation exposures are well within the established limit. Thus, a woman's chances of getting breast cancer from mammography are remote ([1][1]) Thermography displays and measures heat patterns in tissues near the surface of the breast. In 1993, the American Medical Association declined to recommend thermography for medical applications. The Agency for Health Care Policy and Research strongly recommends that thermography should not be used as a screening tool for breast cancer detection ([2][2]). Also, insurance providers, including Medicare, might not pay for thermography for breast cancer screening because it has not been shown to be effective. Those who are seeking alternative medical procedures, such as thermography, should consult with a reputable, licensed health care provider before using such a procedure. 1. [↵][3]For more information about mammograms, call the National Cancer Institute at 1-800-4-CANCER. 2. [↵][4]Clinical Practice Guideline—Quality Determinants of Mammography (Agency for Health Care Policy and Research, Silver Spring, MD, October, 1994), p. 120. [1]: #ref-1 [2]: #ref-2 [3]: #xref-ref-1-1 "View reference 1 in text" [4]: #xref-ref-2-1 "View reference 2 in text"
Effect of derivatives of chrysophanol, a new type of potential antitumor agents of anthraquinone family, on growth and cell cycle of L1210 leukemic cells

The new C-methyl modified derivatives of the anthraquinones chrysophanol and emodin, recently synthesized by us, are potentially bifunctional agents having the ability to intercalate to nucleic acids and also having alkylating properties. Two of these compounds, namely 3-(N,N-bis(2-chloroethyl)-amino)methyl-1,8-dihydroxy-9,10-anthraquinone (Compound 31.662) and its 1,8-di-O-methylated analog (Compound 31.655) have been presently tested on murine leukemic L1210 cells in vitro with respect to their cell cycle specificity. During the initial 24 h of treatment the cytostatic effects of the drugs predominated, manifesting as suppression of cell progression through S (especially through the early portion of S phase) and G2. After 24 h, the cytotoxic effects became apparent, and there was also the appearance of cells with doubled DNA content suggestive of either endoreduplication or impairment of cytokinesis; these cells at higher ploidy level were progressing through S and G2. The observed effects were time- and dose-dependent, occurring at 0.1-0.4 micrograms/ml concentration of 31.662 and 2.0-10.0 micrograms/ml of its methylated analog, either during continuous- or after a 4-h pulse-treatment. Modulation of the cell cycle by the studied drugs is similar to that generally caused by intercalators as well as alkylating agents. However, because no positive evidence of intercalation of the studied drugs to nucleic acids was found, it is possible that alkylation of DNA or other cell constituents may be the primary lesion(s) leading to perturbation of the cell cycle.
Studies of reactions of a series of ions with nitrogen containing heterocyclic molecules using a selected ion flow tube

Abstract A series of reactions between NH3+, O2+, O+, Kr+, N+, N2+, Ar+, Ne+, NH4+ and H3O+ and three heterocyclic molecules (pyridine, pyrimidine and piperidine) were studied using a selected ion flow tube (SIFT) at 298 K. The stability of each ring was investigated through reactivity and the rate coefficients and ion product distributions were determined for each reaction. Most of the reactions proceed by charge transfer or proton transfer when energetically possible, with varying degrees of fragmentation. Based on microreversibility, gas phase formation routes are suggested for the production of ionized pyridine and pyrimidine. If these reverse reactions proceed with no or small activation energy barriers, this would be of interest for formation of heterocyclic rings in the interstellar medium and in the Titan atmosphere. Dissociation mechanisms leading to the major fragment product ions in both the pyridine and pyrimidine reactions have been studied and provide information about the site of interaction between the ions and molecules.
Optimal rate adaptation for VoIP over wireless tandem links

We present an optimization framework for transmitting VoIP packets generated by a multi-rate voice encoder over error-prone wireless links. Our proposed framework aims at identifying the optimal joint source channel coding rates of each voice frame based on the frame perceptual importance such that the quality of the received speech signal is maximized. Simulation results show that our proposed framework outperforms its literature counterparts and has a low computational complexity.
Ascorbate, cyclic nucleotides, citrus and a model for preventing large bowel cancer.

Abstract There is evidence that the risk for developing large bowel cancer is dependent on dietary practice. The “western” diet, high in meats, proteins, fats and refined carbohydrates, and low in fiber, has been causally related to this disease. Diet is known to affect microflora, bile acids, neutral sterols and bacterial enzyme activities in the bowel. These changes may result in the production of carcinogens/ cocarcinogens within the large bowel (in situ). Current evidence suggests that nitrosamines and secondary bile acids and/or cholesterol metabolites may be the carcinogens and cocarcinogens respectively. Although the population of the United States is considered at high risk for developing large bowel cancer, the South-East as well as southern California, Arizona and Florida residents are interesting exceptions. The incidence of large bowel cancer is two-fold lower in these regions, in spite of many residents having previously lived in the higher risk north-eastern and mid-western states. Preliminary studies of dietary practices (meat consumption and dietary fiber) did not find differences which would account for the low risk regions. Our hypothesis is that citrus fruit consumption is the prime factor which can account for these low risk regions. Consumption of citrus fruits may prevent in situ production of fecal nitrosamines, secondary bile acids, and cholesterol metabolites. It has also been reported that ascorbate induces regression of preneoplastic bowel polyps. We suggest that polyp regression is the result of a cellular response in which ascorbate increases cyclic adenosine monophosphate, and the result is biochemical differentiation with an enhanced extrusion of aberrant polyp cells. Florida, which has a large immigrating population from the high risk north-eastern United States, provides an excellent model for metabolic-epidemiological studies of an area at low risk for colon cancer.
Intraoperative Evaluation of Atrioventricular Septal Defect Repair by Color Flow Mapping Echocardiography

Despite improving survival rates after repair of atrioventricular septal defect, many patients require reoperation because of postoperative heart failure. We used intraoperative color flow mapping echocardiography to assess the results of surgical repair of atrioventricular septal defect in 19 consecutive patients and compared those findings with results three to five days and 3 to 11 months after repair. There was close correlation between intraoperative and postoperative color flow mapping echocardiography in estimating the presence and severity of left atrioventricular valve regurgitation. All patients survived surgical repair, but in 4 (21%), postoperative congestive heart failure due to left atrioventricular valve regurgitation developed. The need for reoperation was significantly correlated with the severity of left atrioventricular valve regurgitation (r = 0.68) as estimated by intraoperative echocardiography and preoperative aberrancies in the atrioventricular valve (r = 0.68). Age, weight, additional congenital heart disease, preoperative pulmonary vascular resistance, preoperative atrioventricular valve regurgitation, and postoperative mean pulmonary arterial or left atrial pressure were not significantly correlated with the need for reoperation. Intraoperative color flow mapping echocardiography can accurately predict the development of early postoperative heart failure and subsequent reoperation after surgical repair of atrioventricular septal defect.
A Curious Relationship

WHILE collecting together crystallographic data on the alkali metals, I noticed that the lattice constants for lithium, sodium, potassium, rubidium and caesium had all been determined at 5° K as well as at room temperature. These metals are isostructural, having the A2 structure; in other words, they are body centred cubic with two atoms per unit cell. The changes in atomic volume on cooling from room temperature to 5° K are plotted against the principal quantum number, n, of the outermost occupied shell in Fig. 1. It is seen that the relationship is linear. The volume changes, in A3, are closely reproduced by the equation Various speculators have failed to bring forth a theoretical reason for this linearity.
Ileocecal intussusception caused by lymphoid hyperplasia.

Summary 1. A brief discussion of the etiologyof intussusception in childhood is presented. 2. Two cases of intussusceptioncaused by lymphatic enlargement in the ileum are presented.
Electroosmotic flow pumps with polymer frits

Electroosmotic flow (EOF) pumps with flow rates on the order of 1 ml/min have been designed and fabricated. These pumps use EOF to propel liquid solutions in a compact system with no moving parts. The pumping chamber is filled with densely packed non-porous silica particles, and the particle bed is held in place using two polymeric porous frits. The pump frame is made of acrylic, the frits are made using UV photopolymerization within the custom-built acrylic frame, and the particles are packed using a novel side-bore packing technology. Platinum wire electrodes on both sides of the pump provide the electric field to drive the flow. Deionized water is used as a working fluid in order to minimize Joule heating and increase thermodynamic efficiency. The maximum flow rates and maximum pressures generated by the pumps are 0.8 ml/min and 2 atm, respectively, at 1.0 kV applied voltage. # 2002 Elsevier Science B.V. All rights reserved.
A limited bandwidth envelope follower for efficiency enhancement in a linear Power Amplifier in broadband transmitters

An efficiency enhancement scheme for transmitters using a linear power amplifier (PA) for nonconstant amplitude modulation is proposed. Various current and emerging wireless standards require envelope modulation with wide bandwidth. It is difficult to accommodate this in PA supply-modulation schemes using an efficient switched regulator (or S-modulator) to follow the envelope signal, as the regulation efficiency declines with the increase in bandwidth. In the proposed scheme a linear PA is used, having a switched power supply that is modulated with a limited bandwidth, while an amplitude modulated signal, which may be predistorted, is fed to the PA input. The presented real-time signal processing algorithm generates a limited bandwidth power supply modulation signal to minimize the average headroom in the PA, thus increasing its efficiency, while also allowing the switched-regulator to retain high modulation efficiency. Implementation area and power consumption are estimated for 0.18 mum CMOS.
Laser Doppler flowmetry assessment of peristernal perfusion after cardiac surgery: beneficial effect of negative pressure therapy

Negative pressure therapy has been successfully applied to clean, closed incisions in patients at high-risk for wound complications. Using laser Doppler flowmetry, we evaluated peristernal perfusion after cardiac surgery via median sternotomy, assessing the influence of mammary artery harvesting and the impact of negative pressure therapy. Twenty adult patients underwent median sternotomy for cardiac surgery followed by routine closure. Negative pressure was applied at 125 mm Hg for 4 days postoperatively in patients with increased risk for wound complications (n = 10, negative pressure group); standard dressings were applied to control incisions postoperatively (n = 10). Presternal perfusion was determined at baseline and daily for 4 days postoperatively using laser Doppler flowmetry. Results within and between groups were compared with analysis of variance. No wound complications were encountered in either group. Perfusion increased among the patients who underwent negative pressure therapy and decreased among the controls (P = 0.004). Mammary artery harvesting reduced peristernal perfusion by 25.7% in the controls, but negative pressure increased perfusion by 100% after mammary harvesting (P = 0.04). Negative pressure therapy increased perfusion relative to controls and compensated for reduced perfusion rendered by mammary artery harvesting, providing additional support for 'well wound therapy' in high-risk patients.
A Defect Equilibrium Treatment of Selected Transport Phenomena in Solids

Some aspects of the thermodynamic and transport - related properties of binary solid electrolyte phases are discussed in terms of the associated defect behaviour. In particular, the close relationship between results obtained from an asymmetric polarization experiment and the relevant defect equilibrium diagram for the phase under study, is emphasized.