cssi/SciSciGPT-SciSciNet huggingface dataset:
X-ray-scattering study of higher harmonic satellites near the antiferromagnetic phase transitions in rare-earth metals

We present resonant x-ray magnetic scattering studies of the temperature dependence of the magnetic order parameters of Dy, Ho, Er, and Tm single crystals near their antiferromagnetic phase transitions. The experimentally determined values of the critical exponent \ensuremath{\beta} of Er and Tm, which have c-axis modulated structures, are nearly equal and consistent with the mean-field value (\ensuremath{\beta}=0.47\ifmmode\pm\else\textpm\fi{}0.05 and \ensuremath{\beta}=0.49\ifmmode\pm\else\textpm\fi{}0.06, respectively). The measured values of Dy and Ho, which have spiral magnetic structures, are lower (\ensuremath{\beta}=0.36\ifmmode\pm\else\textpm\fi{}0.04 and \ensuremath{\beta}=0.41\ifmmode\pm\else\textpm\fi{}0.04, respectively). In addition to the primary magnetic order parameters, we have measured the temperature dependence of the intensities of up to four higher harmonics. The exponents of the higher harmonic satellites of Er and Tm exhibit mean-field-like scaling, while those of Ho do not. We discuss these results within the context of simple corrections to mean-field scaling, based on the three-dimensional XY model. We also report measurements of the temperature dependence of the c-axis lattice constants and magnetic wave vectors of all four metals. It is found that the magnetic correlation lengths are reduced near transitions to ferrimagnetic and ferromagnetic phases.
Metabolic transformation of AZTp4A by Ap4A hydrolase regenerates AZT triphosphate.

Abstract The reverse transcriptase (RT) of HIV which has been inhibited by the incorporation of AZT into the primer strand is subject to a deblocking reaction by cellular ATP. This reaction yields unblocked primer plus the dinucleoside tetraphosphate, AZTp 4 A. In the present study, we report that AZTp 4 A is an excellent substrate for the enzyme Ap 4 A hydrolase (asymmetrical dinucleoside tetraphosphatase, EC 3.6.1.17), an enzyme that is widely distributed in many cell types. Progress of the reaction has been monitored by 31 P NMR, and it was found that hydrolysis results in the production of AZTTP:ATP in a 7:1 ratio. The AZTp 4 A was also hydrolyzed at a rate 1.8-fold more rapidly than Ap 4 A. Spectrophotometric assays yielded Michaelis constants of 2.35 and 0.71 μM for Ap 4 A and AZTp 4 A, respectively. It, therefore, appears that Ap 4 A hydrolase can play a useful role in the regeneration of the AZTTP, the active form of AZT, for the inhibition of HIV RT.
CtBP, an Unconventional Transcriptional Corepressor in Development and Oncogenesis

CtBP family proteins are conserved among vertebrates and invertebrates and function as transcriptional corepressors. They repress transcription in a histone deacetylase-dependent or -independent manner. CtBPs play important roles during development and oncogenesis. In this review, their unusual properties, the mechanisms of transcriptional repression, regulation, and their biological functions are discussed.
The Surprising Resilience of the U.S. Dollar

After declining steadily from 1974 to 1994, the U.S. dollar share of international currency holdings has been rising dramatically over the past few years, making the dollar the primary vehicle for ...
Acute aortic syndromes: time to talk of many things.

Lewis Carroll’s poem of 1872 is a useful starting point for identifying issues resulting from confusion over the various acute aortic syndromes.
The Discipline of Toxicology

Abstract The Discipline of Toxicology. Neal, R. A., and Doull, J. (1995). Fundam. Appl. Toxicol. 24, 151-153.
Establishing a Regional Monitoring Strategy: The Pacific Northwest Forest Plan.

Adaptive monitoring design is an iterative process that refines the specifications for monitoring over time as a result of experience in implementing a monitoring program, assessing results, and interacting with users. An adaptive design therefore facilitates ecosystem management. We also discuss lessons of temporal and spatial scales raised by the consideration of a design for ecosystem management. Three additional issues—integration of information from different sources, institutional infrastructure, and the roles of individuals working in an interagency setting—are also identified, but not developed in detail.
Early partial excision of major burns in children.

Abstract Partial primary excision and grafting has been performed in 16 children during the past 7 years. There were 3 deaths, none related to the operative procedure. Great emphasis should be placed on the fact that these were highly selected cases, representing only a very small number of the burns in children seen during this time. This method has merit and should be considered in a child with a large expanse of indubitably full-thickness burn whose condition permits an operative procedure and who has available surface from which skin grafts can be taken. Recently this method has been used in conjunction with 0.5 per cent silver nitrate topical therapy for that part of the burn which has not been excised, and it is felt that the combination of these two methods deserves further trial.
PHOTOCHEMISTRY OF trans‐[Rh(BIS(DIPHENYLPHOSPHINO)ETHANE)2X2][PF6]: TRANSIENT ABSORBANCE KINETIC STUDIES OF METAL‐HALOGEN BOND HOMOLYSIS

— Laser flash photolysis of trans-[Rh(dppe)2X2][PF6] (X=Br and I; dppe=bis(diphenylphosphino)ethane) in CH2Cl2 or CH3CN produces the d7 Rh(II) radicals, [Rh(dppe)2X]+, and halogen atoms. The kinetics of the disappearance of [Rh(dppe)2X]+ radicals in CH2Cl2 or CH3CN were mixed order: H-atom abstraction from solvent to produce the rhodium hydrides, [RhH(dppe)2X][PF6], and Rh/X recombination. In the poor H-atom donor solvent, benzonitrile, Rh/Br recombination was observed to be uncomplicated by competing H-atom abstraction. The hydride complexes [RhH(dppe)2X][PF6], formed by H-atom abstraction were completely characterized by 31P{1H}-NMR, 1H-NMR, and mass specrometry. Cyclohexene was used as an effective trap for photogenerated Br atoms and yielded bromocyclohexane and 3-bromocyclohexene in a relative yield, 1:9. The photochemical mechanism is discussed in light of the transient absorbance and trapping studies.
1185 PHARMACOKINETICS AND BIOAVAILABILITY OF A SUSTAINEDRELEASE THEOPHYLLINE PREPARATION (THEODUR) IN CYSTIC FIBROSIS (CF)

Theophylline (theoph.) improves lung function in some CF patients.Pharmacokinetics and bioavailability of oral theoph. are not defined for these patients. We studied the elimination of theoph. after IV Aminophylline, and absorption of sustained-release oral theoph.(Theodur) in 10 CF patients (age 10-48 yrs). Each received a bolus of aminophylline(4 mg/kg anhydrous theoph.) and 10 plasma theophs.levels were measured over 8 hrs.Elimination half-life (T½), total body clearance (Cl), volume of distribution (Vd) and area under the concentration curve (AUCiv) were determined.Two days later each patient received Theodur(7.47-11.42 mg/kg anhydrous theoph.) and 13 plasma theoph. levels were obtained over 24 hrs.AUCpo was determined.Fraction of the dose absorbed (bioavailability) was calculated (F=AUCpo/AUCiv corrected for dosages).Mean T½±1 SD=4.45±1.58hrs. (range 2.61-7.30).Mean Cl=87.9± 31.6ml/kg/hr(45.6-162.2). Mean Vd=505.8±40.7ml/kg(424.6-572.2). Values are similar to published data for non-CF patients.Mean F= 0.86±0.26(0.45-1.29), in contrast to complete absorption of Theodur reported for non-CF patients.One patient did not develop detectable levels until 20 hrs. after receiving Theodur but rapidly absorbed 96% of oral liquid theoph. There is no consistent abnormality of theoph. distribution or elimination in CF patients. Large interindividual differences in elimination exist as in other patient groups. Absorption of Theodur is delayed or impaired in some CF patients.
Some Mathematical Models for Line Transect Sampling

ANDERSON and POSPAHALA (1970) investigated the estimation of wildlife population size using the belt or line transect sampling method and devised a correction for bias, thus leading to an estimator with interesting characteristics. This work was given a uniform mathematical framework in BURNHAM and ANDERSON (1976). In this paper we extend that mathematical framework to several different sampling models, and a number of interesting discrete probability distributions emerge.
Nicotine potentiates the effects of haloperidol in animals and in patients with Tourette syndrome

Nicotine was found to markedly potentiate haloperidol-induced hypokinesia in rats. Nicotine alone was without effect. Subsequently, concurrent administration of 2 mg nicotine gum to 10 Tourette syndrome patients being treated with haloperidol produced a substantial decrease in tics and improvement of concentration and attention span. Nicotine gum alone was without effect. While 80% of children showed improvement with nicotine gum, 70% completely discontinued the gum because of side-effects, primarily involving nausea and bitter taste. Nicotine may prove useful for treating other neuroleptic responsive disorders, such as schizophrenia and Huntington's disease.
Detection of zeptomolar concentrations of alkaline phosphatase based on a tyrosinase and horse-radish peroxidase bienzyme biosensor

A bienzyme biosensor based on tyrosinase and horse-radish peroxidase is described in a flow injection analysis and cyclic voltammetry for measurement of phenol. Tyrosinase and horse-radish peroxidase were immobilized on the surface of a glassy carbon electrode by bovine serum albumin and glutaric dialdehyde. Phenol was oxidized by tyrosinase and horse-radish peroxidase via catechol to o-quinone in the presence of oxygen and hydrogen peroxide. The o-quinone was reduced to produce catechol (the substrate recycling) on the electrode surface. The enhanced sensitivity of the bienzyme electrode to phenol was observed in the flow injection system comparing with tyrosinase and horse-radish peroxidase monoenzyme electrodes. The mechanisms for enhanced amperometric response to phenol of bienzyme electrode were discussed. The biosensor was used to detect alkaline phosphatase (ALP). A detection limit of 1.4×10−15 M ALP (140 zmol/100 μl) was obtained after 1 h incubation with phenyl phosphate.
Treatment of respiratory infections due to Streptococcus pneumoniae in an era of rising penicillin resistance

Summary For the most part, pathogens commonly involved in acute respiratory infections have not changed substantially over the last decade. Streptococcus pneumoniae and Haemophilus influenzae are the leading cause of these infections. However, penicillin resistance among S. pneumoniae has been rising rapidly with most recent reports indicating resistance rates of 70 % in Hungary, 50 % in Spain, 50 % in France, and 20–30 % in the US. The growing impact of penicillin resistance among pneumococci in antimicrobial prescribing habits cannot be overestimated. High risk pediatric patients for acquiring penicillin resistant pneumococcal infection include : 1) children in day care; 2) children receiving multiple courses of antimicrobials; 3) children receiving prophylactic antimicrobials. Amoxicillin is currently the most frequently prescribed antimicrobial for the treatment of respiratory infections in children. However, the increasing resistance rate among important, virulent pathogens brings this routine into question, although, some authorities contend that amoxicillin and/or penicillin may remain effective in the treatment of relatively penicillin resistant pneumococci. Newer alternative antimicrobial agents are being used with increasing frequency for empiric treatment of acute respiratory bacterial infections in children. Parameters for selecting among the newer alternatives include : 1) in vitro activity against likely pathogens; 2) proven clinical efficacy; 3) low frequency of adverse events; 4) once or twice a day dosing; 5) palatability in oral suspension; and 6) reasonable cost. Against penicillin-resistant pneumococci, three agents have thus far gained the most attention : cefuroxime axetil, cefprozil, and cefpodoxime proxetil. The cost of antibiotic failure must be assessed to include loss of time from work/school for the parent/child for unsuccessful first time therapies. It is essential that local bacterial resistance patterns be monitored in individual communities. Clinical efficacy trials are necessary to assess if alternatives to amoxicillin will show greater efficacy in management of penicillin-resistant pneumococcal respiratory infections in children.
The prevalence of occlusal attrition and considerations for treatment in a noninstitutionalized older population

A representative sample of 520 dentate older adults living in rural Iowa were examined in their homes for the presence of occlusal or incisal attrition. Enamel attrition was found in 84.2% of the population, dentinal attrition in 72.9%, and severe attrition in 4.2%. Approximately 25% of this population's teeth were affected with substantial attrition. Attrition was more prevalent in the anterior segments. The prevalence of substantial attrition was associated with the number of remaining teeth, gender, gingival bleeding, and the use of smokeless tobacco. The decision to treat occlusal attrition in these older people should be based on the etiology and progression of the condition and other factors specific to the individual. The treatment of choice is determined by the extent and severity of the condition and the amount of occlusal vertical dimension lost.
A theory for large deformation and damage of interpenetrating polymer networks

Abstract Elastomers and gels can be formed by interpenetrating two polymer networks on a molecular scale. This paper develops a theory to characterize the large deformation and damage of interpenetrating polymer networks. The theory integrates an interpenetrating network model with the network alteration theory. The interpenetration of one network stretches polymer chains in the other network and reduces its chain density, significantly affecting the initial modulus, stiffening and damage properties of the resultant elastomers and gels. Double-network hydrogels, a special type of interpenetrating polymer network, have demonstrated intriguing mechanical properties including high fracture toughness, Mullins effects, and necking instability. These properties have been qualitatively attributed to the damage of polymer networks. Using the theory, we quantitatively illustrate how the interplay between polymer-chain stiffening and damage-induced softening can cause the Mullins effect and necking instability. The theory is further implemented into a finite-element model to simulate the initiation and propagation of necking instability in double-network hydrogels. The theoretical and numerical results are compared with experimental data from multiple cyclic compressive and tensile tests.
Cobalamin C mutation (methylmalonic aciduria and homocystinuria) in adolescence. A treatable cause of dementia and myelopathy.

DISORDERS of cobalamin (vitamin B12) can be divided into those associated with a deficiency of this essential cofactor and those due to inborn metabolic errors. When they are a result of an inborn ...
The diffusion of internet-based distance education technology among US associate colleges

This paper analyzes the diffusion of internet-based distance education technology (NETDE) among the US associate colleges. The study finds that an institution with experience in using an earlier generation distance education technology is more likely to adopt NETDE than an institution without such an experience. The finding supports the view of Cohen and Levinthal (1990) that an organization's ‘absorptive capability’ plays a significant role in its innovative activities. Institution size also facilitates the adoption of NETDE. We relate this size effect to market power because the size effect is partly caused by customer switching costs present in the NETDE market. Finally, we find that, among public institutions, the presence of close competitors motivates an institution to adopt NETDE earlier.
A retrospective study of the lipid-lowering efficacy and safety of ezetimibe added to hydroxy methylglutaryl coenzyme A reductase therapy in HIV-infected patients with hyperlipidemia

Background Abnormalities in lipid metabolism are a well-described consequence of human immunodeficiency virus (HIV) infection being treated with highly active antiretroviral therapies (HAART). Objective The purpose of this study is to evaluate the lipid-lowering efficacy and safety of ezetimibe added to existing hydroxy methylglutaryl coenzyme A reductase (statin) therapy in HIV-infected patients with hyperlipidemia. Methods This is a retrospective study utilizing a comprehensive electronic patient registry to identify all adult HIV-infected patients seen at the Dallas Veterans Affairs (VA) Medical Center during a 4-year period from October 1, 2002 through October 1, 2006. Results A total of 26 HIV-infected patients initiated on ezetimibe 10 mg were identified, with 14 adult males meeting strict criteria for inclusion. Median age was 54 years (interquartile range [IQR], 45–59) with a median duration of HIV of 13 years, CD4 count of 513 cells/mm 3 (IQR, 289–736), and 9 of 14 patients had undetectable viral loads at baseline. Initiation of ezetimibe 10 mg resulted in a significant decrease in total cholesterol (TC) from baseline (−12.9%, P = 0.001); low-density lipoprotein cholesterol (LDL-C; −25.7%, P = 0.001); and non–high-density lipoprotein cholesterol (non–HDL-C; −23.9%, P = 0.001). There was also a nonsignificant decrease in triglycerides (15.8%, P = 0.43), and an increase in number of patients achieving National Cholesterol Education Program/Adult Treatment Panel III goal for LDL-C after initiation of ezetimibe (+20.9%, P = 0.125). These improvements occurred without adverse effects or changes in virologic and immunologic control. Conclusion Addition of ezetimibe to existing statin therapy in HIV-infected VA patients treated with HAART significantly reduces TC, LDL-C, and non–HDL-C concentrations without apparent side effects or compromising of virologic control.
Treatment of diffuse coronary artery disease with long lengths (≥30 mm) of intracoronary stents

Abstract The interventional treatment of diffuse coronary artery disease often requires the placement of long lengths of intracoronary stents. We have anecdotally observed that target vessel failure rates seem high in these patients. Therefore, we examined long-term angiographic and clinical outcomes in patients treated with long lengths of intracoronary stent. A total of 312 consecutive patients who received ≥30 mm of stent(s) in a single coronary vessel were identified. Bare metal stents (BMS) were placed in 118 of these patients and drug eluting stents (DES) were used in 175 patients. Nineteen patients who received both BMS and DES were excluded from comparative analysis. The mean number of stents placed was 2.4±0.92 and the mean stent length was 45.7±18.2 mm. For the entire cohort, the restenosis rate was 20.8%. Restenosis rates were significantly higher in the BMS group compared to the DES group (34.7% vs. 11.4%; p<0.0001). The rates of major adverse cardiac events were significantly lower in the DES...
Energy efficiency in rental housing

Abstract Where indigenous resources comprise a small amount of state's energy supplies, dollars spent on energy in that state are transferred to export economies, reducing local expenditures for goods and services. Preventing this transfer through conservation actions increases household disposable income, which, through a multiplier effect, exerts substantial impacts on local sales, investments, jobs, and the local tax base. A strong relationship can therefore exist between economic development and energy efficiency in the various sectors of a community. In some areas of a local economy, optimal levels of energy conservation can be achieved without government intervention, because of the existence of market incentives. Institutional barriers in the rental housing sector, however, contribute to a lack of thermal integrity in structures that are in many cases inhabited by those who can least afford anticipated energy price increases. This paper reviews the problems of achieving energy efficiency in rental housing and approaches used by local and state governments to overcome resulting barriers. The experience of Ithaca, NY is highlighted.
Is Nothing Sacred? Christ’s Harrowing through Lewis’s Gothic Lens

“Is nothing sacred? Christ’s Harrowing through Lewis’s Gothic lens” examines the anti-Catholic symbolism and distortion in Matthew Lewis’s The Monk. While it is acknowledged that extensive past research on the perversions of Catholic dogma in the text already exists, this article focuses specifically on the text’s inversion of one piece of Catholic doctrine that has yet to be sufficiently examined – Christ’s Harrowing of Hell – and how Lewis inverted this doctrine to illustrate the Protestant view of Catholicism as selfish, cruel, and hypocritical. Research includes documentation to support claims about the general knowledge of the Harrowing doctrine during Lewis’s time, including the Catechism from the Council of Trent, to shore up the argument that the Harrowing doctrine (and general knowledge of it) would have survived through the Middle Ages to Lewis’s time.
Heavy- and light-hole band crossing in a variable-strain quantum-well heterostructure.

A variable-strain quantum-well semiconductor heterostructure has been designed and studied. Mutually opposite slopes for heavy- and light-hole band edges are obtained by grading the strain within the quantum well from compressive to tensile. A simultaneous red and blue quantum-confined Stark shift for the heavy- and light-hole transitions, respectively, and a unique bias-controlled crossover have been observed by modulation spectroscopy. This indicates that the heavy and light holes experience opposite fields created by the same strain at the same location.
The effects of ambient temperature on amikacin pharmacokinetics in gopher tortoises.

Caligiuri, R., Kollias, G.V., Jacobson, E., McNab, B., Clark, C.H. & Wilson, R.C. The effects of ambient temperature on amikacin pharmacokinetics in gopher tortoises. J. vet. Pharmacol. Therap. 13, 287–291. The pharmacokinetics of amikacin were compared in two groups of tortoises, one held at 20dC and the other at 30dC. The mean (± SD) residence time for amikacin in the 30dC tortoises was 22.67±0.50 h; significantly (P 0.05) in the steady-state volume of distribution (Vd(ss)) between the tortoises held at 30dC (0.241±0.520 l/kg) and those held at 20dC (0.221±0.019 l/kg). The clearance rate was faster (P<0.05) in the warmer tortoises (10.65±2.42 ml/min/kg at 30dC compared to 5.27±0.152 ml/min/kg at 20dC). These data indicate that while the volume of distribution was approximately the same, amikacin remained in the colder tortoises longer because of its slower elimination. The oxygen consumption and metabolism were measured and found to be lower in the colder tortoises, almost by the same 2:1 ratio as clearance time (Cl), mean residence time (MRT), and area under the curve (AUC). The data derived from this limited study indicated that an appropriate therapeutic dosage regimen for amikacin in gopher tortoises at 30dC is 5 mg/kg given i.m. every 48 h. Dr Randy Caligiuri, University of Florida, College of Veterinary Medicine, Box J-6 JHMHC, Gainesville, FL 32610, USA.
Antixenotic and antibiotic resistance in Apium species to Liriomyza trifolii (Diptera: Agromyzidae)

The potential for resistance to the leafminer Liriomyza trifolii (Burgess) in Apium L. species was evaluated in field trials and no-choice tests in the laboratory. In field trials with 159 accessions from throughout the world, only A. leptophyllum (Pers.) F. Muell. from Australia (A162), A. prostratum ssp. prostratum var. filiforme (A. Rich.) Kirk. from Australia (A230), and Chinese smallage ‘Huang Hsin Late’ from Taiwan (A16), consistently and significantly exhibited resistance as measured by an index of infestation (percentage of leaves mined per plant). Only A. leptophyllum completely lacked mining, probably due to resistance based on a filiform leaf architecture. No-choice experiments evaluating leafminer oviposition and development on promising accessions demonstrated that some accessions could reduce leafminer population growth. In these tests, only A. prostratum (A230) was not fed or oviposited upon. Although the other accessions produced no differences in developmental time from egg to pupa, numbers of mines per plant, or the ratio of mines to punctures, significant differences in numbers of pupae and adults, and the ratios of pupae to mines and adults to pupae, indicated substantial antibiosis. Incorporation of these accessions into a celery breeding program and programs for integrated and pesticide resistance management are discussed.
Formation of Phenylene Oligomers Using Platinum−Phosphine Complexes

The reaction of biphenylene with a series of platinum bis-phosphine precursors [PtL2] leads to a variety of C−H and C−C bond activation reactions. With L = triethylphosphine, cleavage of the carbon−carbon bond of biphenylene has been shown to catalytically form tetraphenylene. With L2 = But2PCH2PBut2, the simple C−C cleavage of biphenylene is observed. With L = PPh2But, ortho metalation of the phosphine occurs to give a C−H activation product. Mechanistic details of these reactions are discussed. With L = triphenylphosphine, however, biphenylene is not cleaved by the [L2Pt] fragment, but the independently prepared C−C insertion adduct does react with biphenylene to give five different products, including triphenylene, tetraphenylene, phenyltriphenylene, and hexaphenylene isomers.
Late onset alcoholism: stress or structure.

We studied 60 men (M age = 63.6 years) from six midwest treatment centers to determine whether stress resulting from loss of social-psychological structures was greater for later onset alcoholics. Each subject completed a modified Veteran's Alcoholism Screening Test (V.A.S.T.; Magruder-Habib, Harris, & Franker, 1982) and the Drinking Practices Survey (Adams, 1990). They were then identified as early onset (problem drinking before age 40) and later onset (problem drinking after age 40). Cross tabulations using the chi-square statistic showed that more early onset alcoholics were married than later onset alcoholics. Of the social-psychological structures, only marital status showed a significant relationship with alcoholism. This seemed to confirm that the onset of problem drinking has less to do with stress than with the loss of a spouse who may serve to regulate the older man's drinking.
ETHEPHON (2-CHLOROETHYLPHOSPHONIC ACID) EFFECTS ON SCENEDESMUS QUADRICAUDA (CHLOROPHYCEAE)1,2

SUMMARY Growth of Scenedesmus quadricauda (Turp.) Breb. was significantly increased when the cultures were grown in Ethephon 68–241 (2-chloroethylphosphonic acid) at concentrations of 0.001–1.0 μg · ml−1. At 0.1 μg · ml−1, Ethephon caused a significant increase in RNA levels on a dry weight basis. Total protein and DNA levels increased but not significantly. These data indicate that ethylene, the decomposition product of Ethephon at physiological pH, has some effect on the metabolism of algae.
Gilch and Horner−Wittig Routes to Poly(p-phenylenevinylene) Derivatives Incorporating Monoalkyl Defect-Free 9,9-Dialkyl-1,4-fluorenylene Units

A facile synthetic route allowed access to 1,4-dimethyl-9,9-dihexylfluorene (3) with no monoalkyl defects. Compound 3 was subsequently transformed to monomers for incorporation of 9,9-dihexyl-1,4-f...
Trinucleotide repeats that expand in human disease form hairpin structures in vitro

Abstract We show that repeating units from all reported disease genes are capable of forming hairpins of common structure and threshold stability. The threshold stability is roughly −50 kcal per hairpin and is influenced by the flanking sequence of the gene. Hairpin stability has two components, sequence and length; only DNA of select sequences and the correct length can form hairpins of threshold energy. There is a correlation among the ability to form hairpins of threshold stability, the sequence selectivity of expansion, and the length dependence of expansion. Additionally, hairpin formation provides a potential structural basis for the constancy of the CCG region of the Huntington's disease gene in individuals and explains the stabilizing effects of AGG interruptions in FMR1 alleles.
Macronuclear persistence of sequences normally eliminated during development in Tetrahymena thermophila

During conjugation in the ciliated protozoan, Tetrahymena thermophila, a somatic MAC-ronucleus develops from the germinal MICronucleus. Ten to 20 percent of the MIC genome is eliminated during this process. Three repetitive families have been identified which have different levels of repetition in the MIC and are eliminated to different degrees in the MAC. Some members of two of these families persist in the MAC. In this study, we have looked at these persistent sequences in the MAC of cell lines from a variety of sources including several inbed strains, two sets of caryonides, caryonidal subclones, and vegetatively aged cell clones. The results suggest that the sequences that remain in the MAC have a genetic predisposition to persist. However, epigenetic variations occur as the MAC develops so that only some of the persistent sequences are actually observed in a particular MAC. Polymorphisms may be generated if alternative processing of a single MIC segment occurs. These polymorphisms can later be resolved by phenotypic assortment during vegetative growth. These facultatively persistent sequences appear to differ from sequences previously described in this organism.
Dewetting of molten Sn on Au/Cu/Cr thin-film metallization

On Au/Cu/Cr thin film surface, a drop of molten Sn first spreads out to wet the surface, but it then pulls back to dewet. The latter is due to the spalling of Cu–Sn compounds and exposing the Cr surface to the molten Sn when all of the Cu film has been consumed by the wetting reaction. Dewetting is clearly undesirable for solder joints in electronic packaging; the phenomenon is presented here.
Mean reaction rates and flamelet statistics for reaction rate modelling in premixed turbulent flames

An experimental technique for determining the mean rate of chemical reaction, w >, is developed and applied to turbulent V-shaped flames. Two components of fluid velocity and flamelet position along a line are measured simultaneously. Estimates of w > are obtained by using the experimental data to evaluate gradients of conditional mass fluxes and I >, where I is an indicator function analogous to the reaction progress variable, in two-dimensional conservation equations derived from the continuity equation. The measurement of flamelet position along a line enables corrections for finite flamelet thickness to be incorporated in the estimates of w >. Also obtained are temporal flamelet statistics which arise in the Bray-Champion-Libby (BCL) model for w >: the scalar integral time scale, the flamelet crossing frequency, and the model coefficient g . From w > and the flamelet crossing frequency, Σ and V n |> are inferred, where Σ is the flamelet surface-to-volume ratio and | V n | is the magnitude of the normal component of the flamelet velocity. The scalar integral time scale exhibits a near linear decrease with increasing 〈 I 〉 within the central region of the flame brush. The variation of crossing frequency with 〈 I 〉 is in good agreement with previous studies, and the coefficient g shows a systematic variation, reaching a minimum near 〈 c 〉=0.6. Estimates of 〈 w 〉 and Σ decrease with increasing distance from the flame stabilizer and with increasing turbulent intensity, behavior which is consistent with the observed thickening of the turbulent flame brush. 〈1/| V n |〉 is found to decrease with increasing 〈 I 〉 and with increasing turbulent intensity, but remains within a factor of three of one over the magnitude of the reactant fluid velocity under the experimental conditions studied here.
A decade after SARS: strategies for controlling emerging coronaviruses

The emergence of severe acute respiratory syndrome (SARS) coronavirus and, more recently, Middle East respiratory syndrome (MERS) coronavirus has highlighted the pathogenic and epidemic potential of this virus family. Here, Graham, Donaldson and Baric review key biological properties of coronaviruses and how to target them with potential therapeutics. Two novel coronaviruses have emerged in humans in the twenty-first century: severe acute respiratory syndrome coronavirus (SARS-CoV) and Middle East respiratory syndrome coronavirus (MERS-CoV), both of which cause acute respiratory distress syndrome (ARDS) and are associated with high mortality rates. There are no clinically approved vaccines or antiviral drugs available for either of these infections; thus, the development of effective therapeutic and preventive strategies that can be readily applied to new emergent strains is a research priority. In this Review, we describe the emergence and identification of novel human coronaviruses over the past 10 years, discuss their key biological features, including tropism and receptor use, and summarize approaches for developing broadly effective vaccines.
A repetitive DNA probe for the sensitive detection of Fasciola hepatica infected snails

Abstract Epizootiologic studies on F. hepatica frequently use microscopic techniques for the detection of infected snails, however, the poor efficiency, sensitivity, and specificity associated with these techniques limit their usefulness. A DNA-based test for the identification of snails infected with larval stages of F. hepatica would solve these problems and enable a level of detection accuracy previosly unavailable. We have cloned and sequenced a 124 bp fragment of repetitive DNA from F. hepatica which hybridizes specifically with DNA of F. hepatica but not with DNA of its snail intermediate hosts Fossaria cubensis and Pseudosuccinea columella , or with DNA of Fascioloides magna and Paramphistomum liorchis , ruminant trematodes which share the same intermediate host and same enzootic range as F. hepatica . Using this 124 bp fragment as a probe, infection in saails was detected immediately following miracidial penetration, thus a sensitivity equivalent to the minimum biologic unit of the parasite was achieved. This 124 bp repeated sequence belongs to a large family of 124 bp repeats that share a high level of sequence identity and constitute spproximately 15% of the F. hepatica genome. We also report here the development of a quick and inexpensive DNA extraction protocol for use in field-collected snails. Thus, we have developed both a highly sensitive and specific DNA probe and a means to use the probe in a large epizootiologic study of F. hepatica where thousands of fieldcollected snails need to be assayed for infection.
Ultrastructural changes in the superficial layers of the superior colliculus in Galago crassicaudatus (primates) after eye enucleation.

Several types of terminals were found in the three superficial collicular layers of Galago. At least two axon terminals with round vesicles (R1 and R2) could be distinguished on the basis of vesicle packing and electron density of the cytoplasmic and mitochondrial matrices. R1 axon terminals were characterized by aggregations of vesicles in an electron lucent cytoplasm and mitochondria with a relatively dark matrix, while in R2 axon terminals the vesicles were more evenly distributed in an electron dense cytoplasm and the mitochondrial matrix was pale. R2 endings occurred in clusters in the stratum griseum superficiale; they were absent in the stratum zonale. R1 endings were found in all three superficial collicular layers. Both types of R terminals made asymmetrical contacts with small dendrites, dendritic spines and F profiles. Profiles containing flattened vesicles and establishing symmetrical contacts were numerous, and many could be identified as dendrites by accepting as criteria for dendrites evenly spaced microtubules, clusters of ribosomes and the fact that these F profiles were postsynaptic to other terminals. F terminals were presynaptic to other F profiles, dendrites and somata; they were postsynaptic to R terminals and took part in serial synapses. Dendrodendritic contacts were frequent, somatodendritic contacts rare. After eye enucleation most R2 axon terminals underwent the electron dense degenerative reaction. The degeneration process was a lengthy one; many degenerating boutons were found 30 days after axotomy and some persisted up to 180 days postoperatively. There was strong indication that the superior colliculus received more crossed than uncrossed retinofugal fibers. The crossed and uncrossed retinocollicular axons terminated in two different substrata of the stratum griseum superficiale.
Influence of protein intake and feeding strategy on reproductive performance of dairy cows.

Abstract A study was conducted to determine the impact of dietary CP concentration (13 vs. 20%) and feeding strategy (total mixed ration vs. separate feeding of the forage and concentrate) on reproductive performance of 57 early lactation dairy cows. Cows were assigned to one of four treatments in a 2×2 factorial arrangement. Rations composed of 40% forage (50% grass-legume silage:50% corn silage) and 60% concentrate (DM basis) were fed from d 5 to 100 postpartum. Cows fed a total mixed ration had lower ruminal ammonia and plasma urea N concentrations compared with cows fed separately. Feeding strategy groups showed no differences in reproductive performance. Cows fed a 20% CP ration had higher CP intake, higher ruminal ammonia, and higher urea N concentration in plasma and vaginal mucus. There were no differences between low and high CP groups in days to first observed estrus (24 vs. 27), days to first service (55 vs. 59), days open (72 vs 82) or services per conception (1.5 vs. 1.8). Days to first estimated ovulation were longer (22 vs. 17) in the high vs. low CP groups, and there was an interaction between protein intake and lactation number. Cows managed with an intensive program for detection of estrus and for reproductive health did not show differences in reproductive efficiency when fed 13 or 20% CP rations.
Channel robust speaker verification via feature mapping

In speaker recognition applications, channel variability is a major cause of errors. Techniques in the feature, model and score domains have been applied to mitigate channel effects. In this paper we present a new feature mapping technique that maps feature vectors into a channel independent space. The feature mapping learns mapping parameters from a set of channel-dependent models derived from a channel-independent model via MAP adaptation. The technique is developed primarily for speaker verification, but can be applied for feature normalization in speech recognition applications. Results are presented on NIST landline and cellular telephone speech corpora where it is shown that feature mapping provides significant performance improvements over baseline systems and similar performance to Hnorm and speaker-model-synthesis (SMS).
On the Use of the Surface-Renewal Concept to Describe Cross-Flow Ultrafiltration

Abstract A theoretical model using the surface-renewal concept is developed for describing cross-flow ultrafiltration under dynamic and steady-state conditions. The model can predict the local permeate flux and concentration profile of dissolved solute in the filter. The rate of surface renewal (S) at the membrane surface and the diffusion coefficient (D) of the solute in the solvent are the two parameters of the model. The model is able to correlate literature data of transient permeate flux in the ultrafiltration of skim milk with an average root-mean-square error of 9.9%. The values of S and D, estimated from the model, are 0.84 − 1.74×10−3 s−1 and 0.55 − 2.07×10−9 m2/s, respectively.
A Unified Model for Shear Driven Gas Micro Flows

We analyze steady one-dimensional plane Couette flows in the entire Knudsen regime with the objective of modelling shear-driven rarefied gas flows encountered in various micro electromechanical system (MEMS) applications. In particular, we develop a unified empirical model, which includes analytical expressions for the velocity distribution and shear stress. The new model is validated by comparisons with the linearized Boltzmann solutions available in the literature, as well as hard-sphere direct simulation Monte Carlo (DSMC) results. Overall, the new model predicts the velocity distribution and shear stress with good accuracy for a wide range of Knudsen numbers (0 < Kn ≤ 12), and it is valid for incompressible or low subsonic compressible flows (Ma ≤ 0.3).© 2002 ASME
Synthesis of feedback control systems by gain-contour and root-contour methods

The root-locus method for synthesis of servo systems is modified and extended to cover systems having adjustable time constants. Root-locus and gain-contour methods permit studies of effects upon transient response resulting from variations in gain and variations in time constants to be made independently. The root-contour method facilitates the synthesis of servo systems in which gain is a function of a time constant. Methods for development of gain-contour and root-contour equations for basic servo systems are presented. Feedback charts and illustrative examples are included.
Prediction of thrombus-related mechanical prosthetic valve dysfunction using transesophageal echocardiography

Identification of thrombus-related mechanical prosthetic valve dysfunction (MPVD) has important therapeutic implications. We sought to develop an algorithm, combining clinical and echocardiographic parameters, for prediction of thrombus-related MPVD in a series of 53 patients (24 men, age 52 +/- 16 years) who had intraoperative diagnosis of thrombus or pannus from 1992 to 1997. Clinical and echocardiographic parameters were analyzed to identify predictors of thrombus and pannus. Prevalence of thrombus and diagnostic yields relative to the number of predictors were determined. There were 22 patients with thrombus, 19 patients with pannus, and 12 patients with both. Forty-two of 53 masses were visualized using transesophageal echocardiography (TEE), including 29 of 34 thrombi or both thrombi and panni and 13 of 19 isolated panni. Predictors of thrombus or mixed presentation include mobile mass (p = 0.009), attachment to occluder (p = 0.02), elevated gradients (p = 0.04), and an international normalized ratio of or = 1 predictor. The prevalence of thrombus in the presence of or = 3 predictors is 14%, 69%, and 91%, respectively. Thus, TEE is sensitive in the identification of abnormal mass in the setting of MPVD. An algorithm based on clinical and transesophageal echocardiographic predictors may be useful to estimate the likelihood of thrombus in the setting of MPVD. In the presence of > or = 3 predictors, the probability of thrombus is high.
Dinaciclib (SCH727965) Inhibits the Unfolded Protein Response through a CDK1- and 5-Dependent Mechanism

Evidence implicating dysregulation of the IRE1/XBP-1s arm of the unfolded protein response (UPR) in cancer pathogenesis (e.g., multiple myeloma) has prompted the development of IRE1 RNase inhibitors. Here, effects of cyclin-dependent kinase inhibitor, SCH727965 (dinaciclib), on the IRE1 arm of the UPR were examined in human leukemia and myeloma cells. Exposure of cells to extremely low (e.g., nM) concentrations of SCH727965, a potent inhibitor of CDKs 1/2/5/9, diminished XBP-1s and Grp78 induction by the ER stress-inducers thapsigargin (Tg) and tunicamycin (Tm), while sharply inducing cell death. SCH727965, in contrast to IRE1 RNase inhibitors, inhibited the UPR in association with attenuation of XBP-1s nuclear localization and accumulation rather than transcription, translation, or XBP-1 splicing. Notably, in human leukemia cells, CDK1 and CDK5 shRNA knock-down diminished Grp78 and XBP-1s up-regulation while increasing Tg lethality, arguing for a functional role for CDK1/5 in activation of the cytoprotective IRE1/XBP-1s arm of the UPR. In contrast, CDK9 or CDK2 inhibitors or shRNA knockdown failed to down-regulate XBP-1s or Grp78. Furthermore, IRE1, XBP-1, or Grp78 knockdown significantly increased Tg lethality, as observed with CDK1/5 inhibition/knockdown. Finally, SCH727965 diminished myeloma cell growth in vivo in association with XBP-1s down-regulation. Together, these findings demonstrate that SCH727965 acts at extremely low concentrations to attenuate XBP-1s nuclear accumulation and Grp78 up-regulation in response to ER stress inducers. They also highlight a link between specific components of the cell cycle regulatory apparatus (e.g., CDK1/5) and the cytoprotective IRE1/XBP-1s/Grp78 arm of the UPR that may be exploited therapeutically in UPR-driven malignancies.
Differences in multiple-target visual search performance between non-professional and professional searchers due to decision-making criteria.

Professionalvisualsearches,suchasthoseconductedbyairportsecuritypersonnel,often demandhighlyaccurateperformance.Asmanyfactorscanhinderaccuracy,itiscriticalto understand the potential influences. Here, we examined how explicit decision-making criteria might affect multiple-target search performance. Non-professional searchers (college undergraduates) and professional searchers (airport security officers) classified trials as ‘safe’ or ‘dangerous’, in one of two conditions. Those in the ‘one = dangerous’ condition classified trials as dangerous if they found one or two targets, and those in the ‘one = safe’ condition only classified trials as dangerous if they found two targets. The data suggest an important role of context that may be mediated by experience; non-professional searchers were more likely to miss a second target in the one = dangerous condition (i.e., when finding a second found target did not change the classification), whereas professional searchers were more likely to miss a second in the one = safe condition.
Screwworms (Diptera: Calliphoridae): a new liquid medium for rearing screwworm larvae.

Screwworm, Cochliomyia hominivorax , larvae reared on liquid nutrient medium containing as much as 12% dried whole blood and no dried cottage cheese were as large as those reared on the standard liquid medium that contains dried cottage cheese and 6% dried whole blood. The specific level of additional dried whole blood required to offset the decrease in protein caused by the removal of dried cottage cheese ranged from 1% to 3% but was controlled principally by larval density. On the basis of current screwworm production of approximately 500 million flies per week, a net annual savings of about 1.2 million dollars per year can be realized by replacing the dried cottage cheese in the nutrient medium with increased amounts of dried whole blood.
Stem cells and stroke: opportunities, challenges and strategies.

Introduction: Stroke remains the leading cause of disability in the Western world. Despite decades of work, no clinically effective therapies exist to facilitate recovery from stroke. Stem cells may have the potential to minimize injury and promote recovery after stroke. Areas covered: Transplanted stem cells have been shown in animal models to migrate to the injured region, secrete neurotrophic compounds, promote revascularization, enhance plasticity and regulate the inflammatory response, thereby minimizing injury. Endogenous neural stem cells also have a remarkable propensity to respond to injury. Under select conditions, subventricular zone progenitors may be mobilized to replace lost neurons. In response to focal infarcts, neuroblasts play important trophic roles to minimize neural injury. Importantly, these endogenous repair mechanisms may be experimentally augmented, leading to robust improvements in function. Ongoing clinical studies are now assessing the safety and feasibility of cell-based thera...