cssi/SciSciGPT-SciSciNet huggingface dataset:
Backwards Principal Component Analysis and Principal Nested Relations

In non-Euclidean data spaces represented by manifolds (or more generally stratified spaces), analogs of principal component analysis can be more easily developed using a backwards approach. There has been a gradual evolution in the application of this idea from using increasing geodesic subspaces of submanifolds in analogy with PCA to using a "backward sequence" of a decreasing family of subspaces. We provide a version of the backwards approach by using a "nested sequence of relations" which define the decreasing sequences of subspaces which need not be geodesic. Because these are naturally inductively added in a backward sequence, they are frequently more tractable and overcome difficulties with using geodesics.
Ion beam synthesis of buried SiC layers in silicon: Basic physical processes

Abstract For the ion beam synthesis (IBS) of buried stoichiometric epitaxial layers of 3C–SiC in silicon, a complicated structure in the as-implanted state has been identified as a favourable starting structure prior to annealing. It consists of a nearly rectangular depth distribution of equally sized, oriented 3C–SiC nanocrystals sandwiched between two amorphous zones. The basic physical processes leading to such a distribution of amorphous and crystalline phases during high-dose, high-temperature carbon implantation into silicon are reviewed in this article. In particular, the precipitation of carbon in a self-organized lattice of amorphous inclusions, the formation of stable 3C–SiC nuclei via precursors, beam-induced nucleation of SiC in amorphous Si:C, the different growth of crystalline SiC precipitates in crystalline and amorphous silicon and the ballistic destruction of SiC nanoclusters by the continued bombardment with energetic ions – resulting in a carbon-induced amorphization at elevated temperatures – are described.
Use of Newborn Screening Program Blood Spots for Exposure Assessment: Declining Levels of Perfluorinated Compounds in New York State Infants

Temporal biomonitoring studies can assess changes in population exposures to contaminants, but collection of biological specimens with adequate representation and sufficient temporal resolution can...
Cycling of7Be and210Pb in a High DOC, Shallow, Turbid Estuary of South-east Texas

The Sabine-Neches estuary is a shallow, turbid estuary in south-east Texas with high concentrations of dissolved organic carbon (DOC). The sediment inventory of210Pb and239,240Pu indicates that only a fraction of the particle-associated nuclides that reach the estuary were retained in the sediment. To better understand the cause for this low-sediment inventory of particle-reactive nuclides,7Be and210Pb concentrations have been measured in the dissolved and particulate phases, in addition to the DOC and suspended particle concentrations. The ratios of dissolved to particulate concentrations of7Be and210Pb were generally higher than in most other coastal waters. The dissolved residence times of7Be and210Pb (accounting for riverine input) varied between 0·6 and 9·6 days and 1·7 and 9·8 days, respectively. Distribution coefficients (Kd)ranged between 1500 and 87 100 cm3 g−1for7Be and 2600 and 37 000 cm3 g−1for210Pb. TheseKds are lower than those reported for most coastal waters. There was no significant correlation between suspended particle concentration andKdof either7Be and210Pb; this has been observed for many other particle-reactive nuclides, suggesting that particle concentration is not the primary controlling variable for the removal of particle-reactive nuclides in these high DOC waters. The average particle residence time in this estuary is ∼2 days. The relatively lowKdvalues, longer dissolved residence times of7Be and210Pb, longer particle residence times and shorter hydraulic residence times compared to other coastal areas, result in only a partial removal of particle-reactive radionuclides in this estuary.
A General Fluorescence Resonance Energy Transfer (FRET) Method for Observation and Quantification of Organometallic Complexes under Reaction Conditions

A two-fluorophore FRET system provided a more general approach than previously described fluorescence techniques to observing and quantifying organometallic complexes under reaction conditions. Over the concentration range of 3 × 10−7 to 5 × 10−6 M, this method provided quantification with faster time resolution and greater sensitivity than is possible with NMR spectroscopy.
Creep of aluminum syntactic foams

Abstract Aluminum syntactic foams with densities of 1.2–1.5 g/cm 3 were deformed at 500 °C under constant uniaxial compressive stresses ranging from 5 to 14 MPa. The foam creep behavior is characterized by a short primary stage and a long secondary stage where the strain rate is constant and minimum, followed by a tertiary stage at high stresses. The minimum strain rate varies with stress according to an apparent stress exponent n with a low value ( n ≈ 1) for stresses below 8 MPa, and a high value ( n ≈ 14) above 8 MPa. Finite-element modeling provides predictions for the foam strain rates that are in qualitative agreement with experimental results. Modeling also shows that the matrix transfers load to the ceramic elastic spheres, explaining the exceptionally high creep resistance of these syntactic foams as compared to aluminum foams without ceramic spheres. Modeling finally reveals that stresses vary with position in the matrix and time during creep, and that the onset of tertiary stage is associated with the appearance of sharp stress concentrations in the matrix.
A cAMP response element within the latency-associated transcript promoter of HSV-1 facilitates induced ocular reactivation in a mouse hyperthermia model.

Herpes simplex virus type 1 (HSV-1) recombinant strain 17CRE contains a site-directed mutation in the 7-bp CRE consensus sequence located 38 nucleotides upstream of the transcription start site. Scarified mouse corneas received inoculations of 17syn+ (parent), 17CRE, and rescue 17CREr. Slit lamp examination of herpetic lesions and tear film swabs containing infectious virus showed that 17CRE had the same acute phenotype as 17syn+ and 17CREr. At 4 weeks, when the corneas had healed and latency was established, mice received hyperthermic shock. Eye swabs taken 24 h after hyperthermia showed that 17CRE reactivated significantly less than 17syn+ and 17CREr, while no significant differences were found in HSV-1 DNA genome copy numbers and latent virus in the trigeminal ganglia. These results are evidence that this CRE site in the LAT promoter facilitates ocular HSV-1 reactivation in mice.
Effects of nutritional state, insulin, and glucagon on lipid mobilization in rainbow trout, Oncorhynchus mykiss.

Abstract The effects of nutritional state, insulin, and glucagon on lipid mobilization were determined in rainbow trout, Oncorhynchus mykiss . In nutritional state experiments, fish were either fed continuously (except 24 to 36 hr prior to experimentation) with commercial trout chow or fasted for 4 weeks. Lipase activity in liver tissue isolated from fasted fish and cultured for 5 hr was greater than that in tissue isolated from fed fish and cultured. The presence of glucose (5.55 m M ) in the incubation medium accentuates lipolytic activity in both liver and adipose tissue. Hormone response was assessed both in vivo and in vitro . Salmon insulin was injected into anesthetized fish (fed continuously except 24 hr prior to injections) in 10 μl of saline/g body weight; final hormone dose was 100 ng/g body weight. Tissue and plasma were sampled 1 and 3 hr after injection. Insulin resulted in depressed plasma FA concentration and reduced hepatic triacylglycerol lipase activity. In vitro effects of hormones were evaluated by incubating liver and adipose tissue pieces in Hanks-MEM. Glucagon (bovine/porcine) directly stimulated lipid breakdown in both liver and adipose tissue. These actions were manifested by enhanced FA and glycerol released into the culture medium and by elevated triacylglycerol lipase activity. Insulin (bovine) generally appeared antilipolytic as this agent inhibited glucagon-stimulated lipase activity and glucagon-stimulated FA release. Furthermore, insulin (in the presence of glucose) reduced net lipolysis, as indicated by glycerol release, compared to control cultures. These results indicate that nutritional state and glucose are important modulators of lipid mobilization and that glucagon and insulin act directly on lipid storage sites to coordinate lipolysis in rainbow trout.
Tests for the genotoxicity of m-AMSA, etoposide, teniposide and ellipticine in Neurospora crassa

Abstract The antitumor agents m-AMSA, etoposide, teniposide and ellipticine have been reported to be potent clastogens in mammalian cells but non- or weakly mutagenic in bacteria; these observations have been correlated to the interference of these chemicals with DNA topoisomerase II activity in the former, but not in the latter, organisms. The genotoxicity of these 4 agents was evaluated using ad-3 reverse- and forward-mutation tests in Neurospora crassa. These agents (up to 0.8 μmole/plate) did not cause reversion in conidia of the ad-3A frameshift strains N24 and 12-9-26 using the overlay plate test, as contrasted to the positive control frameshift mutagen ICR-170. Heterokaryon 12 (H-12) of N. crassa permits the recovery of all classes of forward mutation at the ad-3+ region, including multilocus deletions. Using resting conidia of H-12 in a suspension assay, ellipticine was moderately mutagenic but no increase in ad-3 mutants was noted with the other 3 agents at a dose of 100 μg/ml. In vegetative cultures of H-12 grown in the presence of these agents, all 4 agents were nonmutagenic at a dose of 100 μg/ml. The positive control mutagen ICR-170 was mutagenic in both resting conidia and growing cultures of H-12. A similarity between the topoisomerase II of N. crassa and DNA gyrase of bacteria is suggested.
The adaptive value of maladaptive behavior, or you've got to be stupid in order to be smart

Abstract The genetic contribution to primate behavior may include a predisposition to vary responses to the same stimuli. Such variability produces a mix of “erroneous” responses to stimuli, but such errors may serve to monitor change in contingencies in the environment. Social relationships are to be regarded as a consequence of monitoring and adapting to a changing social environment rather than as direct consequences of genetic fitness strategies. Primate social behavior represents a much greater degree of fine tuning to specific partners and contexts than could be obtained through genetic programming. Specific responses may serve to produce information and should not necessarily be regarded as optimum solutions to a particular problem. It may be the ability to vary responses and modify behavior that is selected for rather than a particular response itself.
Phase cancellation: A cause of acoustical shadowing at the edges of curved surfaces in B-mode ultrasound images

Acoustical shadowing occurring at the edges of curved objects is one of the most frequently observed artifacts in ultrasound imaging. This artifact has been generally ascribed to refraction and reflection effects at the boundary between the curved object and the surrounding tissues. However, the shadowing that would be produced by pure refraction and reflection may not correspond in all circumstances to what is most often seen clinically, i.e., a sharp, discrete shadow projecting down from the edge. We used a tissue-mimicking contrast detail phantom, speed of sound (SOS) 1477 m/s, containing cylindrically shaped wells to investigate the origin of these shadows. Using solutions of relatively high SOS (20% ethylene glycol), approximately equivalent SOS (distilled water), and low SOS (70% isopropyl alcohol), the phantom was scanned with the scanhead face oriented perpendicular to and parallel to the central axes of the cylinders. Shadowing could be produced in both cases when there was a SOS difference between the contents of the cylinders and the phantom. When scanning perpendicular to the cylinders, refraction and reflection effects could have contributed to any shadowing produced, but when the scan planes were oriented parallel to the central axes of the cylinders, neither refraction nor reflection could be occurring to a significant degree. The shadowing produced in these circumstances could be better explained by a phenomenon well known in transmission ultrasonography called phase cancellation. Phase cancellation would produce shadowing independent of scan plane orientation, and could contribute to the shadowing generated in clinical imaging.
Effects of Preshift Small Magnitude of Reward Received during Goalbox Placements on the Negative Contrast Effect

During preshift, one experimental group of rats was given a large magnitude of food reward following a traversal of a straight alley and during a goalbox placement, while the other experimental group was given a small reward during goalbox placement and a large reward following a run. During postshift, all experimental groups were given a small reward of food following a traversal down the runway and during a goalbox placement. A control group was maintained on small reward during placements and following a traversal throughout the study. Only the group who received preshift large reward during placement and following a runway response ran slower to small reward during postshift than the control group maintained on small reward (negative contrast effect).
Analysis of helium purge flow in a solid breeder blanket

A numerical analysis of the purge flow in sphere-pac solid breeder has been carried out using the modified Darcy equations. The results show that: (1) the tritium accumulation in the purge and permeation through the wall is not a concern, (2) pressure drop expressions for fully developed flow are applicable in evaluating the pressure drop in a developing flow regime because of the very short entry length and (3) the pressure drop for low porosity (~20%) and high flow rate considered in conceptual reactor designs can be unacceptably high.
Computations of a laminar backward-facing step flow at Re = 800 with a spectral domain decomposition method

The two-dimensional laminar incompressible flow over a backward-facing step is computed using a spectral domain decomposition approach. A minimum number of subdomains (two) is used; high resolution being achieved by increasing the order of the basis Chebyshev polynomial. Results for the case of a Reynolds number of 800 are presented and compared in detail with benchmark computations. Stable accurate steady flow solutions were obtained using substantially fewer nodes than in previously reported simulations. In addition, the problem of outflow boundary conditions was examined on a shortened domain. Because of their more global nature, spectral methods are particularly sensitive to imposed boundary conditions, which may be exploited in examining the effect of artificial (non-physical) outflow boundary conditions. Two widely used set of conditions were tested: pseudo stress-free conditions and zero normal gradient conditions. Contrary to previous results using the finite volume approach, the latter is found to yield a qualitatively erroneous yet stable flow-field. Copyright © 1999 John Wiley & Sons, Ltd.
Spin fluctuation rates in myoglobin azide: Comparison of Mössbauer and EPR results

We have analyzed the Mossbauer spectra of low-spin ferric myoglobin azide, taken in small applied field from 30 K to 200 K, in terms of a dynamic lineshape model [1]. Our results show fluctuation rates having a temperature dependence which is different from that measured using EPR forT<10 K [2–4] and shed new light on the vibrational modes coupling to the spinS=1/2 of the heme iron.
Thermochemical regularities among lanthanide and actinide oxides

Abstract A systematic treatment of the thermochemical properties of binary and complex oxides of the lanthanides and actinides in terms of other wellcharacterized species and thermochemical cycles is given in this paper. Since the trivalent lanthanides provide a reference series with which the lanthanide and actinide sesquioxides can be compared, the trivalent ion energetics are considered first. Recent interest in monoxides, prompted by high pressure synthesis of lanthanide monoxides and interest in divalent actinide metals and oxides, has led us to include a treatment of the relative stabilities of monoxides and sesquioxides. The important tetravalent state is viewed from the perspective of the dioxides as well as the perovskites BaMO3. Since there are no higher valent lanthanides, systematic trends in pentavalent and hexavalent complex actinide oxides are not treated in this review.
Telomere Length Regulation—A View from the Individual Chromosome Perspective

Telomeres are specialized structures at chromosome termini implicated in oncogenesis and cellular aging. Since both phenomena are related to variations in telomere length it is of interest to understand mechanisms responsible for telomere length regulation. Recent studies in mammalian cells indicate that specific chromosomes may have specific telomere lengths, suggesting the existence of chromosome-specific factors involved in telomere length regulation. Although these chromosome-specific factors are largely unknown at present, in the mouse evidence suggests a possible role of centromere position in telomere length regulation-telomeres closer to centromeres (i.e., p-arm telomeres) are significantly shorter than their counterparts more distant from centromeres (i.e., q-arm telomeres). The mouse may be a special case because its karyotype consists almost exclusively of acrocentric chromosomes in which p-arm telomeres and centromeres are located immediately adjacent to each other. However, a weak correlation between telomere length and centromere position is observed in the case of nonacrocentric human and Chinese hamster chromosomes, suggesting that the putative centromere position effect might be evolutionarily conserved. Alternatively, telomere length in individual nonacrocentric chromosomes may be affected by the sequence organization of subtelomeric chromosome regions or by some other, currently unknown, factors.
Accuracy of Palpating the Long Head of the Biceps Tendon: An Ultrasonographic Study

Objective To determine the accuracy of palpating the long head of the biceps tendon (LHBT) within the intertubercular groove with the use of ultrasonographic localization as a gold standard. Design Prospective, single-blinded pilot study. Setting Sports medicine clinic at a tertiary care academic institution. Participants Twenty-five male and female asymptomatic volunteers ages 24-41 years (mean, 30.9 ± 4.3 years) with body mass indices of 19.3 to 36.3 kg/m 2 (23.84 ± 4.8 kg/m 2 ). Methods Three examiners of differing experience (a sports medicine board-certified staff physician, a sports medicine fellow, and a physical medicine and rehabilitation resident) identified the LHBT location in the intertubercular groove via palpation on a subject in the supine position and marked its location by taping an 18-gauge Tuohy needle to the skin overlying the groove. The examiner order was randomized. A fourth examiner who was blinded to the palpation order assessed the previous examiner's palpation accuracy by comparing the needle position to the sonographically determined tendon position. Main Outcome Measures Needle placement in relation to the intertubercular groove was graded as being within the groove, medial to the groove, or lateral to the groove. In the latter 2 cases, the distance from the needle to the closest groove edge was recorded. Results Overall accuracy rate was 5.3% (4/75), ranging from 0% (0/25) for the resident to 12% (3/25) for the fellow ( P ≤ .007 for interexaminer differences). All missed palpations were localized medial to the intertubercular groove by an average of 1.4 ± 0.5 cm (range, 0.3 for the fellow to 3.5 cm for the resident). Conclusion Based on the current methodology, clinicians have a tendency to localize the intertubercular groove medial to its actual location. Consequently, clinicians should exercise caution when relying on clinical palpation to either diagnose a biceps tendon disorder or perform a bicipital tendon sheath injection. When clinically indicated, sonographic guidance can be used to accurately identify the LBHT within the intertubercular groove.
Intestinal absorption of bile acid glucuronides in rats.

While the intestinal absorption of taurine, glycine, and sulfate conjugates of bile acids has been studied extensively, nothing is known about the absorption of bile acid glucuronides. In the present study, the intestinal phase of the enterohepatic circulation of two bile acid glucuronides was examined. [3β-3H]cholic acid 3-O-β-d-glucuronide or [3β−3H]lithocholic acid 3-O-β-d-glucuronide was perfused through isolated segments of ileum or jejunum with intact blood supply in rats prepared with a biliary fistula. [14C]Taurocholic acid was perfused simultaneously with each glucuronide to compare glucuronide absorption with that of an actively transported bile acid. Intestinal absorption was determined by measuring the rate of secretion of labeled bile acid in bile. The absorption of [3H]cholic acid glucuronide by the ileum and jejunum was one fortieth and one eighth, respectively, that of [14C]taurocholic acid. Comparison of the two glucuronides show that [3H]lithocholic acid glucuronide absorption was 18 and 10 times greater than [3H]cholic acid glucuronide absorption from the jejunum and ileum, respectively. Collectively, the above observations suggest that glucuronidation of bile acids markedly reduces absorption from the small intestine.
COMPLETE HEART BLOCK AND SUBARACHNOID HEMORRHAGE: WHAT'S THE LINK?

Cardiac involvement of sarcoidosis occurs in 25% of patients. The most common manifestation is complete heart block (CHB) from granulomatous infiltration of the conduction system. A dual-chamber implantable cardioverter-defibrillator (ICD) is implanted for pacing and primary prevention of sudden
The effect of polyamine homologation on the transport and cytotoxicity properties of polyamine-(DNA-intercalator) conjugates.

An efficient five-step synthetic method was developed to access a homologous series of spermidine−acridine and spermidine−anthracene conjugates. The derivatives were comprised of a spermidine fragment covalently tethered at its N4 position to either an acridine or anthracene nucleus via an aliphatic chain (e.g., spermidine−[aliphatic tether]−acridine). The distance separating the spermidine and aromatic nucleus was altered by using different tethers comprised of four or five methylene units, respectively. These ligands (2−5) were shown to inhibit human DNA topoisomerase-II (TOPO-II) activity at 10 μM. Enzymatic activity was assessed as the ability to unknot (decatenate) and cleave kinetoplast DNA (kDNA). Polyamine conjugation did not disrupt the ability of the acridine−spermidine conjugates 2 and 3 to inhibit TOPO-II activity as compared with the 9-aminoacridine and 9-(N-butyl)aminoacridine controls (at 10 μM). In general, the acridine derivatives (2 and 3) showed higher TOPO-II inhibitory activity than t...
Minimally invasive coronary artery bypass grafting decreases hospital stay and cost

Objective The authors performed a retrospective cost analysis for patients undergoing revascularization of their left anterior descending (LAD) coronary artery either by standard coronary artery bypass grafting (CABG), percutaneous transluminal coronary angioplasty (PTCA), or minimally invasive coronary artery bypass grafting (MICABG). Background Data Minimally invasive CABG has become a safe and effective alternative treatment for single-vessel coronary artery disease. However, the acceptance of this procedure as a routine alternative for the treatment of coronary artery disease will depend on both long-term graft patency rates as well as a competitive market cost. Methods The authors conducted a retrospective analysis of three patient groups undergoing LAD coronary revascularization from January 1995 to July 1996. Ten patients were selected randomly from this period after PTCA of an LAD lesion with or without stenting. Nine patients underwent standard CABG on cardiopulmonary bypass with a left internal mammary artery. Nine patients received MICABG via a limited left anterior thoracotomy and left internal mammary artery to LAD grafting without the use of cardiopulmonary bypass. Results Percutaneous transluminal coronary angioplasty (n = 10) was unsuccessful in two patients. One patient in the MICABG group (n = 9) was converted successfully to conventional CABG because of an intramyocardial LAD and dilated left ventricle. There was no operative morbidity or mortality in any group. Average length of stay postprocedure was decreased significantly for both the MICABG and PTCA groups when compared with that of conventional CABG (n = g) (2.7 + 0.26, p = 0.009, and 2.6 + 0.54, p = 0.006, vs. 4.8 + 0.46, respectively). Total hospital costs for the MICABG and PTCA groups were significantly less when compared with those of standard CABG ($10,129 + 1104, p = 0.0028, and $9113 + 3,039, p = 0.0001, vs. $17,816 + 1043, respectively). There were no statistically significant differences between the MICABG and PTCA groups. Conclusions The final role of minimally invasive CABG is unclear. This procedure is clearly cost effective when compared with that of PTCA and conventional CABG. The long-term patency rates for MICABG will determine its overall efficacy.
Thermodynamic and kinetic studies of laser thermal processing of heavily boron-doped amorphous silicon using molecular dynamics

Laser thermal processing (LTP) has been proposed as a means to avoid unwanted transient enhanced diffusion and deactivation of dopants, especially boron and arsenic, during the formation of ultrashallow junctions. Although experimental studies have been carried out to determine the efficacy of LTP for pure Si and lightly B-doped junctions, the effects of high concentrations of dopants (above 2% B) on the thermodynamic and kinetic properties of the regrown film are unknown. In this study, a classical interatomic potential model [Stillinger–Weber (SW)] is used with a nonequilibrium molecular dynamics computer simulation technique to study the laser thermal processing of heavily B-doped Si in the range 2–10 at. % B. We observe only a small effect of boron concentration on the congruent melting temperature of the B:Si alloy, and thus the narrowing of the “process window” for LTP is predicted to be small. No significant tendency for boron to segregate was observed at either the regrowth front or the buried c-Si interface during fast regrowth. The B-doped region regrew as defect-free crystal with full activation of the boron atoms at low boron concentrations (2%), in good agreement with experiments. As the concentration of boron increased, the number of intrinsic Si defects and boron interstitials in the regrown materials increased, with a minor amount of boron atoms in clusters ( 150 ps, compared to 5 ps in tight binding). The importance of adequate system size is discussed.
Where Is It? How Deaf Adolescents Complete Fact-Based Internet Search Tasks

An exploratory study was designed to describe Internet search behaviors of deaf adolescents who used Internet search engines to complete fact-based search tasks. The study examined search behaviors of deaf high school students such as query formation, query modification, Web site identification, and Web site selection. Consisting of two fact-based search tasks, the study was done in four regional day school programs for the deaf. As students conducted two search tasks, they completed task analyses of the selected Web sites and gave reasons for their selections. The research also identified the processes used by deaf students to compensate for limited English reading abilities while navigating search engines results that were typically written well above deaf students' average reading level. The results demonstrated that deaf adolescents were unable to initiate, conduct, analyze, or validate effective Internet searches in response to fact-based search tasks.
Importance of validation of accuracy of duplex ultrasonography in identifying moderate and severe carotid artery stenosis.

Background and Purpose: The accuracy of carotid duplex ultrasonography (CDU) in detecting moderate and severe carotid artery disease was evaluated in comparison with arteriography. Methods: Accuracy of CDU was correlated with arteriographic findings using North American Symptomatic Carotid Endarterectomy Trial (NASCET) criteria in 147 internal carotid arteries. The duplex measurements consisted of peak systolic velocities (PSVs), end diastolic velocities (EDVs), and internal carotid PSV to common carotid artery PSV ratios (ICA/CCA). Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and overall accuracy (OA) using the 3 parameters were determined. Receiver operating characteristic (ROC) curves were constructed from the ultrasonographic data for detection of 50% or greater stenosis (moderate disease) and 70% or greater stenosis (severe disease). Results: CDU for detecting ≥50% stenosis had a sensitivity of 100%, specificity of 87.8%, and accuracy of 96.6%. The area ...
Addition of organolithium reagents to α-chlorovinyltri-methylsilane

Abstract α-Chlorovinyltrimethylsilane adds n- and t-butyllithium to form 1-trimethylsilyl-1-hexene and 3,3-dimethyl-1-trimethylsilyl-1-butane, where its reaction with phenyllithium affords mainly phenyltrimethylsilane and ethynyltrimethyl-silane.
The density issue in hair transplantation.

backgound Modern hair restoration procedures may involve, individually or in combinations, flaps, grafts consisting of plugs, slits, strips, minigrafts, or micrografts, with or without alopecia reduction. objective To review the density achieved using mini-micrografting technique compared with that accomplished by plug methodology. methods Hair counts per square centimeter were done on both mini-micrografted and plug cases from the author's practice. result Comparable density (terminal hair per square centimeter) was noted to occur with either technique but accomplished with fewer sessions using mini-micrografting methodology and relatively dense packing of grafts. conclusion The density issue is a nonissue if comparable numbers of hair are transplanted per square centimeter.
Neuroprotective effects of 619C89, a use-dependent sodium channel blocker, in rat traumatic brain injury

Release of the excitatory amino acid (EAA) neurotransmitter glutamate has been implicated in secondary tissue damage following central nervous system (CNS) trauma and ischemia. The present study evaluated the neuroprotective actions of 619C89, a sodium channel blocker that inhibits ischemia-induced glutamate release, on traumatic brain injury (TBI) in rats using a lateral fluid percussion model. Various motor-related behavioral outcomes were used to evaluate neurologic function. Glial fibrillary acidic protein (GFAP) immunostaining and Cresyl violet staining were used to assess the histological changes. Treatment with 619C89, at a dose of 30 mg/kg administered intravenously 15 min before brain injury, significantly attenuated behavioral deficits at 24 h and 1 week. At 2 weeks, neuronal loss in the CA1 and CA3 pyramidal cell layers of the hippocampus was significantly decreased by 619C89 administration. Treatment with this compound also significantly attenuated increases in GFAP-immunoreactivity in both ipsilateral and contralateral CA1 regions. The present results suggest a potential therapeutic role for sodium channel blockade and/or glutamate release inhibition in the treatment of TBI.
Solution thermochemical study of ligand substitution reactions of hybrid alkyl/fluoroalkoxy phosphorus ligands in the L2Fe(CO)3 system

Abstract The enthalpies of reaction of (BDA)Fe(CO) 3 (BDA=(C 6 H 5 )CHCHC(O)CH 3 , benzylideneacetone) with a series of novel fluorinated phosphine ligands, PR 2 OR f (R=Ph, i Pr, Cy; R f =(CH 2 ) 2 (CF 2 ) 5 CF 3 ) and (R f O) 2 PCH 2 CH 2 P(OR f ) 2 (dOR f pe), leading to the formation of L 2 Fe(CO) 3 complexes (L=PR 2 OR f ) have been measured by solution calorimetry in THF at 50°C. Remarkably, reaction enthalpies are essentially invariant over this series of ligands, despite the differing steric and electronic properties of the phosphorus ligands. Carbonyl stretching frequencies help in the estimation of useful electronic parameters associated with the novel phosphorus ligand series.
The Asrama System: The History and Hermeneutics Of A Religious Institution

This is the first full-length study of the asrama system, a Hindu construct consisting of four legitimate ways of leading a religious life. Together with the varna (class) system, it forms one of the pillars of Hindu life. Olivelle traces its early history and how it gradually established connections with other Hindu religious institutions to emerge as one of the two central dimensions of the Hindu dharma. It represents a major study not only of Hindu religious history but also of the tradition of Indian hermeneutics.
Topographical response differentiation and reversal in 3-month-old infants

In two experiments spontaneous topographical response differentiation was assessed in twenty-eight 3-month-old infants during free-operant conditioning. In Experiment 1, 15 infants were tested in the laboratory for a single session. Activity of all limbs produced somesthetic feedback, but only movement of the right leg produced visual conjugate reinforcement (mobile movement). Response localization was exhibited early in acquisition when leg activity exceeded arm activity, but specific differentiation between legs did not occur until the first extinction period when the right leg significantly dominated the left. Arm activity, as well as activity of all limbs of a noncontingent control group, remained unchanged throughout the session. In Experiment II, 13 infants were tested in their home cribs for successive days. All exhibited rapid and stable differentiation between legs, and 4 of 5 exhibited rapid and complete reversal of leg dominance when control of the mobile action was shifted to the other leg. The phenomenon was interpreted in terms of the optimization principle.
Surface studies of polyimide thin films via surface-enhanced Raman scattering and second harmonic generation

Two polyimides having the same backbone chemical structure and different pendant side groups at the 2- and 2′-positions of the diamine, the six methylene units capped with 4-cyanobiphenyl end groups and trifluoromethyl, were synthesized (6FDA-6CBO and 6FDA-PFMB). Surface-enhanced Raman scattering and surface optical second harmonic generation measurements show that after rubbing the major change in 6FDA-PFMB surface appears in the orientation of the dianhydride, which was originally planar, but becomes tilted with respect to the surface plane. In the case of 6FDA-6CBO, rubbing also causes the originally planar 4-cyanobiphenyls to tilt away from the surface and assume an azimuthally anisotropic distribution.
Dynamic Heights and Zonal Geostrophic Transports in the Central Tropical Pacific during 1979–84

Abstract Dynamic height is calculated from XBT and surface salinity data in the central Pacific using a mean temperature–salinity (T–S) relation in the usual way below the thermocline but assuming isohaline water in the upper layer where the temperatures are isothermal. This scheme produces a better estimate of dynamic height than the use of a mean T–S relationship alone and produces significant improvements near the equator where small pressure gradients imply large geostrophic currents. During the El Nino of 1982–83, water of very low surface salinity was observed spanning the equator; this event is attributed both to extreme local rainfall and anomalous advection from the western Pacific. Geostrophic transports of the major surface currants are estimated for the period January 1979 through December 1984. The North and South Equatorial countercurrents are found to have the largest annual fluctuations, and the vertical displacements of the thermocline associated with these fluctuations are qualitatively ...
Substituted 3-aminomethylbenzoxazoline-2-thiones as potential antibacterial agents.

A series of 3-aminomethylbenzoxazoline-2-thiones was tested for possible antibacterial activity. Out of the 17 compounds screened, 11 exhibited some degree of activity.
Cardiac MRI as a diagnostic tool in pulmonary hypertension

Pulmonary hypertension is characterized by alterations in the viscoelastic properties of the pulmonary arteries, leading to increased pulmonary arterial stiffness and elevated pressures. Early detection and accurate quantification of pulmonary hypertension are limitations to conventional noninvasive imaging and may have therapeutic implications. Cardiac MRI provides important information that can aid the clinician, particularly relating to morphologic right ventricular alterations and quantification of stiffness, as well as providing a novel prognostic framework.
A comparative study of bureaucratic corruption in Latin America and the U.S.A.

Abstract The starting point of this paper is a conceptual model of bureaucratic corruption, based on the assumption that bureaucrats (a) maximize personal utilities, and (b) control a monopoly in the production of certain goods and services. This conceptual model leads to a system of three equations representing demand, supply and market clearance of the goods and services supplied by the bureaucracy. Using the market clearance equation, an equation for the level of corruption in a bureaucracy is obtained. The conceptual model helps to specify the signs of the partial derivatives of the level of corruption with respect to the explanatory variables. Two sets of data are used to test the model. The first refers to levels of corruption in the bureaucracies of 17 Latin American countries, while the second deals with levels of corruption of Federal officials working in individual states in the U.S.A., state officials, and local officials. The conclusions obtained thus far using the statistical analysis confirm the expectations derived with the conceptual model.
Data assimilation with regularized nonlinear instabilities

In variational formulations of data assimilation, the estimation of parameters or initial state values by a search for a minimum of a cost function can be hindered by the numerous local minima in the dependence of the cost function on those quantities. We argue that this is a result of instability on the synchronization manifold where the observations are required to match the model outputs in the situation where the data and the model are chaotic. The solution to this impediment to estimation is given as controls moving the positive conditional Lyapunov exponents on the synchronization manifold to negative values and adding to the cost function a penalty that drives those controls to zero as a result of the optimization process implementing the assimilation. This is seen as the solution to the proper size of ‘nudging’ terms: they are zero once the estimation has been completed, leaving only the physics of the problem to govern forecasts after the assimilation window. We show how this procedure, called Dynamical State and Parameter Estimation (DSPE), works in the case of the Lorenz96 model with nine dynamical variables. Using DSPE, we are able to accurately estimate the fixed parameter of this model and all of the state variables, observed and unobserved, over an assimilation time interval [0, T]. Using the state variables at T and the estimated fixed parameter, we are able to accurately forecast the state of the model for t > T to those times where the chaotic behaviour of the system interferes with forecast accuracy. Copyright © 2010 Royal Meteorological Society
Endosonography-assisted endoscopic mucosal resection of submucosal tumors of the gastrointestinal tract

Submucosal tumors (SMTs) of the gastrointestinal tract are uncommon and are often incidental findings at endoscopy. Until recently, the management of SMT consisted of a choice of 2 relatively unsatisfactory options: either watchful waiting without a definitive tissue diagnosis or empirical surgical resection. Two important technical advances in endoscopy in the last decade, endosonography and endoscopic mucosal resection, have the potential for making a major impact on the management of SMTs. This article describes the role of endosonography-assisted endoscopic mucosal resection in providing a tissue diagnosis and predicting complete resection of SMTs. We will review the techniques and criteria for the selection of lesions that should be considered for endoscopic mucosal resection and which ones can be followed conservatively.
Transmissibility of the Influenza Virus in the 1918 Pandemic

BackgroundWith a heightened increase in concern for an influenza pandemic we sought to better understand the 1918 Influenza pandemic, the most devastating epidemic of the previous century.Methodology/Principal FindingsWe use data from several communities in Maryland, USA as well as two ships that experienced well-documented outbreaks of influenza in 1918. Using a likelihood-based method and a nonparametric method, we estimate the serial interval and reproductive number throughout the course of each outbreak. This analysis shows the basic reproductive number to be slightly lower in the Maryland communities (between 1.34 and 3.21) than for the enclosed populations on the ships (R0 = 4.97, SE = 3.31). Additionally the effective reproductive number declined to sub epidemic levels more quickly on the ships (within around 10 days) than in the communities (within 30–40 days). The mean serial interval for the ships was consistent (3.33, SE = 5.96 and 3.81, SE = 3.69), while the serial intervals in the communities varied substantially (between 2.83, SE = 0.53 and 8.28, SE = 951.95).Conclusions/SignificanceThese results illustrate the importance of considering the population dynamics when making statements about the epidemiological parameters of Influenza. The methods that we employ for estimation of the reproductive numbers and the serial interval can be easily replicated in other populations and with other diseases.
Membrane adsorption characteristics determine the kinetics of flow‐through transductions

Retrovirus-mediated gene transfer is currently limited by random Brownian motion of the retrovirus. This limitation can be overcome by flowing the retrovirus solution through a porous membrane that supports the target cells, leading to a significant increase in the transduction efficiency. This procedure is termed "flow-through transduction." In this study, we characterized the effects of the fluid flowrate and the influence that membrane characteristics have on the flow-through transduction procedure. The transduction efficiencies increased with flowrate until a plateau was reached at average flow velocities exceeding 0.3 cm/h for flow times of 3 to 4 h, using a collagen-coated depth (COL) membrane. A correlation between the optimal time for maximal gene transfer using flow-through transductions and the optimal time for maximal virus activity on the membrane was found, suggesting that the membrane adsorption capacity for virus determined the amount of gene transfer that could occur.Membrane adsorption characteristics were further investigated using two different membrane types: a tracketched polyester screen (PE) membrane and the COL membrane. Flow-through transductions using the PE and COL membranes showed that a high level of gene transfer could be attained using the COL membrane while the PE membrane gave much lower transduction efficiencies. The addition of the polycation polybrene (PB) changed these results markedly, making transductions achieved on the PE membrane similar in number to those obtained on the COL membrane. Since PB is believed to influence the virus adsorption to PE membrane, these results further support the conclusion that the increase in gene transfer achieved by the flow-through transduction procedure is due to virus adsorption to the membrane. The flow-through transduction procedure thus leads to co-localization of the viral vector and the target cell that in turn leads to a high transduction efficiency.
The use of DNA-intercalating dye to monitor cell fusion and microinjection.

Abstract A conventional method for microinjection, using erythrocyte ghosts as the injection vector, has been modified to provide a protocol for the highly efficient delivery of small quantities of material into the cytoplasm of target cells. The technique is applicable for use with a variety of proteins, sugars, nucleotides and dyes. When the intercalating dye propidium iodine is included within the sealed ghosts their subsequents fusion target cells can be continously monitored by fluorescence spectroscopy, providing a convenient and sensitive parameter of cell-cell fusion. The protocol can be adpated for use with both adherent and non-adherent target cells, and be used to monitor the relative effectiveness of a variety of fusogenic agents.
The relationship between predictability and problem behavior for students with severe disabilities

Two single-case studies were conducted to examine the extent to which signaled (predictable) and unsignaled (unpredictable) events were associated with changes in the level of problem behavior during instruction. Two students with moderate-to-severe intellectual disabilities and autism participated in the study. Each student was nominated for the study based on a teacher's report that problem behaviors were much more likely when novel or unsignaled events occurred. Functional assessments were conducted with each student and the specific predictability features (signals) associated with low and high levels of problem behavior were identified. Multi-element and reversal designs were employed to examine the extent to which increased predictability was associated with reduced problem behavior. Results supported the use of functional assessment procedures to determine whether signals that provide information about the content, duration, timing, and/or consequences of future events could reduce problem behaviors.
Probability calculation for the Durbin-Watson correlation test

Abstract One of the assumptions of least squares regression models is that the regression error terms are independent of each other. This condition is often violated when analyzing data taken from observations over time; an important type of data in environmental studies. The statistic used to estimate whether the lag 1 coefficient of autocorrelation is equal to zero is known as the Durbin-Watson statistic. This article develops a methodology for the implementation of the probability calculation for the Durbin-Watson test for serial autocorrelation in least squares regression models. The algorithms defined by Durbin and Watson in their 1971 paper were examined, essential calculations were defined and a computer implementation using FORTRAN 77 was developed. The computer code was verified via the simulation of a simple known regression with no autocorrelation and confirmation that the distribution of the results is roughly uniform. Timing curve for runs using a DEC VAX-11/750 and a full listing of the subroutine source code are also included.