cssi/SciSciGPT-SciSciNet huggingface dataset:
Assessing the preservation of biogenic strontium in fossil bones and tooth enamel

Analyses of the strontium isotope ratio ( 87 Sr/ 86 Sr) of vertebrate fossils can provide information about palaeobiological attributes such as habitat use and movement patterns. Diagenetic contaminants can alter the 87 Sr/ 86 Sr ratio of fossils, however, complicating palaeobiological interpretations. Several pretreatment protocols have been developed to separate diagenetic contaminants from biogenic Sr. While these methods can remove some diagenetic Sr, it has not been shown that any technique removes all contamination. The extent to which pretreatment removes diagenetic Sr can be quantified through analysis of the 87 Sr/ 86 Sr ratios of fossil marine mammal bones and teeth buried in sediments with non-marine diagenetic 87 Sr/ 86 Sr signatures. To do this, we examined Holocene seals recovered from archaeological sites in Greenland and California, as well as a Miocene whale from Maryland. Our results demonstrate that although pretreatment eliminated some contaminants from bone, a large percentage (up to 80%) of diagenetic Sr remained after treatment. In contrast, pretreatment does appear to remove nearly all (≥∼95%) diagenetic Sr from tooth enamel. Copyright  2003 John Wiley & Sons, Ltd.
Innovative Approach to Fatigue Crack Propagation in Concrete Pavements

An innovative approach to characterize the micro- and macromechanical damage phenomena resulting from fatigue cracking and relate them to the design and durability of pavements has been developed. In this approach, crack propagation and its associated damage are considered as irreversible processes, and hence the general framework of the thermodynamics of irreversible processes is used to model fatigue crack propagation behavior. A constitutive equation, the modified crack layer model, is used to extract material parameters characteristic of the pavement's resistance to fatigue crack propagation. These parameters are the specific energy of damage, [.gamma][.minute], and a dissipative characteristic, [.beta][.minute], of the paving mixture. The general applicability of the proposed approach has been extended to examine fatigue crack propagation data of concrete reported in the literature. It is found that the proposed model describes fatigue crack propagation behavior of concrete pavements over the entire ...
The role of the deep femoral artery as an inflow site for infrainguinal revascularization

Abstract Purpose: Although the deep femoral artery (DFA) is well acknowledged as an outflow vessel for inflow reconstruction, data are lacking concerning the suitability of the DFA as an inflow site for distal bypass. Methods: From 1986 to 1992 we performed 268 consecutive infrainguinal reversed vein bypasses, of which 56 (21%) originated from the middle or distal DFA. The indications for DFA-origin grafts included inadequate vein length, need for concomitant extended profundaplasty, and avoidance of groin scarring from previous reconstruction or infection. The surgical approach to the DFA (standard, posteromedial, or lateral) was tailored to the patient. All grafts were monitored with serial duplex scanning surveillance. Results: Primary and secondary patency rates of DFA origin grafts were 78% and 96% at 3 years. These patency rates were no different from those grafts originating from the common femoral artery (66%; 89%), the superficial femoral artery (69%; 87%), or the popliteal artery (66%; 87%). Hemodynamic failure was detected in seven DFA-origin grafts, but only one resulted from disease in the common femoral artery or DFA proximal to the origin of the vein graft. Conclusions: Direct lateral and posteromedial approaches to the DFA were used extensively in repeat operative situations, avoiding dissection in a scarred groin and shortening the length of vein required to perform an autogenous bypass. We conclude that in appropriately selected patients, the DFA origin technique increases the versatility of lower extremity vein bypass grafting without sacrificing durability. (J VASC SURG 1993;18:416-23.)
Laparoscopic partial nephrectomy versus laparoscopic cryoablation for the small renal tumor.

Abstract We sought to compare perioperative and short-term outcomes of laparoscopic partial nephrectomy versus laparoscopic cryoablation in patients with peripheral small renal tumors. Prospectively accrued data of patients with a small renal tumor (≤3 cm) undergoing laparoscopic partial nephrectomy (group 1, n = 153) or laparoscopic cryoablation (group 2, n = 78) were compared retrospectively. Patients undergoing laparoscopic partial nephrectomy were younger (mean age, 60.6 vs 65.6 years; P = 0.005), healthier (American Society of Anesthesiologists class 3/4 present in 46% vs 75%; P = 0.001), had a lower baseline serum creatinine (90.1 vs 106.0 μmol/L [1.02 vs 1.2 mg/dL]; P = 0.01), a larger tumor size (2.3 vs 2.1 cm; P = 0.02), and fewer cases of solitary kidneys (5% vs 23%; P = 0.000). Laparoscopic partial nephrectomy was associated with greater blood loss (211 vs 101 mL; P = 0.000) and a higher incidence of delayed complications after hospital discharge (16.3% vs 2.2%; P = 0.01) compared with cryoablation. Both groups were comparable with regard to operative time ( P = 0.77), intraoperative complications ( P = 0.1), postoperative complications ( P = 0.55), hospital stay ( P = 0.13), convalescence ( P = 0.96), and postoperative serum creatinine (112.2 vs 123.7 μmol/L [1.27 vs 1.4 mg/dL]; P = 0.31). Local recurrence was detected over a mean follow-up time of 5.8 months in group 1 (0.6%) and 24.6 months in group 2 (3%). Although the technical simplicity, decreased blood loss, and somewhat lower complication rate are attractive features of renal cryotherapy, this must be balanced against the current lack of long-term follow-up data that are needed to confirm the oncologic adequacy of this developmental procedure. Laparoscopic partial nephrectomy, albeit a technically advanced procedure, duplicates established open principles and has therefore evolved to become our current minimally invasive nephron-sparing procedure of choice in the majority of patients with a small renal tumor.
The T&.sbnd;N&.sbnd;PR model of radiation response

Abstract A general model of biological response to radiation is proposed which incorporates recent findings and observations on the nature of common repair processes. The dynamic nature of radiation response through extensive repair processes is contrasted with the assumption of irrepairability implicit in “Target Theory”. It is proposed that a high degree of resistance to the biological effects of radiation, presumably DNA damage, is achieved through a combination of constitutive (N Type), induced (T Type) and specialized (PR Type) repair systems. Each repair system is capable of complete repair; however, in fact, they interact in complex but predictable ways to achieve the high resistance required for life in an environment where all living organisms are erratically or chronically exposed to injurious levels of irradiation. A qualitative consideration of repair system interactions provides insight into radiation response and explains many seemingly paradoxical responses to radiation.
Application of high-pressure liquid chromatography to studies of collagen production by isolated cells in culture

Abstract Techniques for assessing collagen production by cells in culture are usually based on evaluation of uptake of radiolabeled proline into collagen. Although simple in theory, this approach is often flawed because of uncertainties concerning the specific activity of labeled proline in the precursor pool for collagen synthesis. An alternative approach is to assess collagen production directly by measuring hydroxyproline in proteins secreted by cultured cells, although this has been difficult, due to the insensitivity of the methods available. Here we apply high-pressure liquid chromatography using reverse-phase elution of 7-chloro-4-nitrobenzo-2-oxa-1,3-diazole derivatives of hydroxyproline to measure collagen production by fibroblasts. The method is easy to perform and allows quantitation of hydroxyproline down to 5 pmol, making it applicable to fibroblasts in 12-well culture plates. Collagen production was shown to be constant over a period of 24 h, with a mean rate of 391 ± 18 (SE n = 14) ng collagen/106 cells/h. Similar values were obtained using thin-layer chromatography and an enzyme-linked immunosorbent assay for type I collagen, but these techniques were judged to be less convenient and required additional assumptions compared with the technique described here in full.
Measuring a Topological Transition in an Artificial Spin- 1 / 2 System

A collection of qubits are used to measure the topological invariants of an engineered spin system.
Studies of dijet and trijet production in ep interactions at HERA

Measurements of dijet and trijet production in photoproduction, deep inelastic scattering and in the transition region between them, performed with the H1 and ZEUS detector at HERA are presented. The predictions of next-to-leading-order perturbative QCD are compared to the measured cross sections and found to be compatible with the data over a wide kinematic range. PACS: 12.38.Qk Experimental test – 13.60.Hb Total and inclusive cross sections
Substrate Identity in Mammalian Melanogenesis

A total of 45 chemical substances have been tested as substrates for melanogenesis identified by pigment formation in melanocytes of freshly plucked hair roots incubated in 1 mM solutions of the compounds. Melanocytes of human red and blond hair and of guinea-pig red-blond hair can utilize eatechol, tyrosine, dopa, and 14 of their derivatives as substrates for pigment formation. Melanocytes of human red and blond hair, but not guinea-pig red-blond hairs form pigment from dopamine and methyl dopa. Human and guinea-pig hair melanocytes form dark brown pigments from dopa, dopa methyl ester, and dopamine; lighter brown pigments from tyrosine, eatechol, dopa ethyl ester, dopa n-propyl ester, and dopa n-butyl ester; and golden yellow pigments from dopa isopropyl and isoamyl esters. Identification of the substrates utilized for melanogenesis may provide new clues to possible means of specifically affecting melanocyte function.
MEASURING THE APPROPRIATENESS OF MULTIPLE‐CHOICE TEST SCORES1,2

A student may be so atypical and unlike other students that his or her aptitude test score fails to be a completely appropriate measure of his or her relative ability. We consider the problem of using the student's pattern of multiplechoice aptitude test answers to decide whether his or her score is an appropriate ability measure. Several indicators of appropriateness are formulated and evaluated with a simulation of the Scholastic Aptitude Test. Applications to investigations of alignment errors, exceptional creativity, suboptimal test taking strategies, and unauthorized access to test items are noted.
The cancer stem cell hypothesis: in search of definitions, markers, and relevance

Cancer is a disease of genes. Inherited or somatic alterations in genes are what make a normal cell ignore growth-controlling signals and form a tumor that eventually leads to the destruction of the organism. Based on accumulated knowledge on the genetic composition of cancer cells, the clonal evolution model of tumorigenesis was established, which explains multiple aspects of human disease and clinical observations. However, the recently popularized cancer stem cell hypothesis questions that all or most tumor cells can participate in tumor evolution and restricts this property to a subset of them defined as 'cancer stem cells' due to their stem cell-like characteristics. Enthusiasm surrounding this area of investigation and its presumed clinical implications led to a spurt of studies in various cancer types and model systems. Rigorous study design and critical data interpretation have to be employed to test the scientific and clinical relevance of the cancer stem cell hypothesis and its relationship to the clonal evolution model.
The Response of a Fluid-Solid Interface to a Moving Disturbance

Abstract : The problem of a moving point force on a fluid-solid interface was considered by the authors in preceding papers. A related three-dimensional problem is studied in the present investigation. The moving point force is replaced here by a source which moves at a given distance through the fluid parallel to the interface. The steady-state solution to this problem for supersonic source velocities was obtained through the use of DeHoop's modification of Cagniard's technique, and expressions for the displacements at the interface are presented. (Author)
Fetal behavior and the endogenous opioid system: D1 dopamine receptor interactions with the kappa opioid system.

Abstract Opioid or dopaminergic drugs can alter the motor behavior of rat fetuses on day 21 of gestation (E21). This study was conducted to a) characterize the behavioral effects of specific opioid agonists in the fetus, b) determine the effects of selective blockade of opioid receptors, and c) characterize the interaction between the dopamine and kappa opioid systems. Neither morphine nor the mu agonist DAMGO produced effects on fetal motor activity, whereas the kappa agonist U50,488 resulted in a pronounced increase in motor behavior. The selective antagonists β-funaltrexamine (mu) and nor-binaltorphimine (kappa) produced no behavioral effects when administered alone. The D1 antagonist SCH-23390 did not reverse the activational effects produced by U50,488, but the kappa antagonist nor-binaltorphimine successfully blocked the increases in fetal behavior produced by the D1 agonist SKF-38393. These results are consistent with the hypothesis that activation of the dopamine system promotes activity at kappa opioid receptors to bring about changes in fetal motor activity.
Dissolution of iron oxides by phagotrophic protists : Using a novel method to quantify reaction rates

In previous work, we have reported the dissolution of iron oxides within the acidic food vacuoles of marine protozoan grazers as evidence of a novel mechanism for the conversion of refractory iron solids to more labile forms in oxic surface waters. This paper expands upon those initial studies and presents a new technique to study the reaction of iron oxides in seawater, based on the synthesis of colloidal ferrihydrite containing an inert tracer. Measuring the accumulation of the tracer in the dissolved phase enables the determination of the rate and extent of iron oxide reaction, even for kinetically slow processes and regardless of the fate of iron in the system. The validity of the method as a means of following the reaction of iron oxides in seawater is shown here in a series of co-dissolution studies and in several photochemical kinetics experiments. In laboratory studies of the dissolution of colloidal ferrihydrite by protozoan grazers, the inert tracer method enables an improved estimate of the rat...
A practical reconstruction algorithm for CT noise variance maps using FBP reconstruction

Accurate prediction of reconstructed noise in computed tomography (CT) images is important for purposes of system design, optimization and evaluation. A large body of work describes noise prediction methods for CT, the vast majority of which assume stationarity of both noise and signal processes. Consequently, these methods are usually applied to and evaluated using simple phantoms, and only a portion of the image is scrutinized. In this work, we derive a practical method for reconstructing CT noise variance maps for arbitrary objects. Photon Poisson noise and system electronic noise are considered. The final formula has the same structure as that of the filtered backprojection (FBP) formula, but with different weighting factors and convolution kernels. The algorithm is verified using computer simulations of the Shepp-Logan phantom, and a good match is found between the predicted noise map from one single noisy scan and the measured noise using 128 noisy scans. As compared to other proposed noise models, our complementary work provides a method of noise prediction by simple adaptation of FBP reconstruction algorithms. The result is a tool that can be useful for system optimization and evaluation tasks as well as the design of reconstruction filters.
Catatonia in autistic disorder: A sign of comorbidity or variable expression?

Catatonia, once solely attributed to schizophrenia, is now thought to be associated with many disorders. Autistic disorder shares some symptoms with catatonia, namely, mutism, echopraxia/echolalia, and stereotypies. Catatonia in autism may therefore be a variant of the autistic condition. However, organic deficits and psychiatric disorders, such as bipolar disorder, have also been linked with the manifestation of catatonia. Individuals with autism presenting with these comorbid conditions may therefore be at increased risk for catatonia. Little is written of the association of autism and catatonia to clarify the possibility of catatonia as a variant or a sign of a comorbid condition. The authors discuss three autistic patients and suggest specific etiologies for the symptoms of catatonia which presented in these cases. The therapeutic and diagnostic importance of comorbid disorders in autism is stressed.
Microstructure segmentation using active contours—Possibilities and limitations

Image data often carries redundant or unnecessary information. Consider a hypothetical image containing a phase embedded into a matrix. If the shape of the phase is of interest then the matrix information is redundant. Identification and classification of the pixels belonging to the matrix and the phase is a process called image segmentation. Active contouring is an edge detection based segmentation method that produces results superior to that of traditional edge detectors. High noise tolerance and built-in functional flexibility offered by the active contouring models make it an attractive technique in various applications including data compression, tracking of growth of a phase, and boundary outlining for further three-dimensional volume reconstruction. In this paper, the factors impacting the final contours will be discussed and shown in practice. It will also be shown that the technique is especially attractive when employed to process complex real microstructure datasets with limited user interaction.
Interactions between THC and cannabidiol in mouse models of cannabinoid activity.

Rationale Interest persists in characterizing potential interactions between Δ9-tetrahydocannabinol (THC) and other marijuana constituents such as cannabidiol (CBD). Such interactions may have important implications for understanding the long-term health consequences of chronic marijuana use as well as for attempts to develop therapeutic uses for THC and other CB1 agonists.
The Rural War: Captain Swing and the Politics of Protest

Carl J. Griffin’s book attempts to update and replace Eric Hobsbawm and George Rude’s classic study of the rural uprising in 1830 in England, Captain Swing. This earlier work, completed in 1969, ha...
Extreme lability of the C-8 proton: a consequence of 7-methylation of guanine residues in model compounds and in DNA and its analytical application.

Abstract 1. The C-8 proton of 7-methylguanosine rapidly exchanges with the solvent. The half-life of deuterium exchange is 5.5 min at pH 4.1, 28°, while at pH 7 the exchange is too fast to be measured by NMR spectroscopy. 1,7-Dimethylguanosine and 7-methylinosine behave analogously. The mechanism of this exchange seems to involve acidic dissociation of the C-8 proton. Two mechanistic alternatives, namely, tautomerism and reversible hydrolytic opening of the imidazole ring can be ruled out. This behaviour of 7-methylguanosine is analogous to that of compounds related to thiamine. 2. 7-Methylation of guanine residues in DNA results in a similar rapid isotope exchange at C-8. This was shown by methylating [8-3H]guanine-labeled DNA with dimethylsulfate. The amount of tritium released from the DNA as tritiated water corresponded to the amount of 7-methylguanine. 3. This observation provides a simple and selective method for the determination of the extent of 7-methylation of guanine residues in alkylated nucleic acids.
Possible detection of interstellar deuterium

The abundance of deuterium relative to hydrogen is an important parameter in constructing models of the early expansion of the universe in Big-Bang cosmologies. Calculations by Wagoner et al. (1967) and by Wagoner (1973) show that the deuterium abundance would be very sensitive to the density of baryons in the fireball and hence to the present mean mass density of the universe. Reeves et al. (1973) use data on the abundance of deuterium in the solar system to deduce a ratio of n sub D/n sub H = 1.8 plus or minus 0.8 x 10 to the minus 5 power, and note that other authors have pointed out that processing of matter in stars slowly reduces the deuterium abundance in the galaxy.
A Computationally viable higher‐order theory for laminated composite plates

Abstract : A variational higher-order theory involving all transverse strain and stress components is proposed for the analysis of laminated composites plates. Derived from three-dimensional elasticity with emphasis on developing a viable computational methodology, the theory is well studied for finite element approximations as it incorporates both C0 and C-1 continuous kinematic fields and Poisson boundary conditions. From the theory, a simple three-node stretching-bending finite element is developed and applied to the problem of cylindrical bending of a symmetric carbon/epoxy laminate for which an exact solution is available. Both the analytic and finite element result were found to be in excellent agreement with the exact solution for a wide range of the length-to-thickness ratio. The proposed higher-order theory has the same computational advantages as first-order shear-deformable theories. the present methodology, however, provides greater predictive capability, especially, for thick-section composites.
Syllabification of intervocalic consonants

Two tasks were used to study the syllabification of intervocalic consonants like the /V’s of melon and collide. In an oral task, subjects reversed the syllables in words; in a written task, they selected between alternative syllabifications. Even in the oral task, subjects’ responses were influenced by whether their spellings of the words contained a single letter (r) or a double letter (10. Responses in the two tasks were also affected by the stress pattern of the word, the phonetic category of the intervocalic consonant, and the nature of the preceding vowel. The results are discussed in relation to theories of syllabification. o 1988 Many investigators (e.g., Spoehr, 1981; Segui, 1984) have proposed that the syllable plays a role in the processing of spoken and written language. However, studies of the syllable’s role in language processing have been hindered by uncertainty about how words are divided into syllables. With a word like demon, for instance, is the /m/ part of the first syllable, part of the second syllable, or part of both syllables? Different theories of syllabification offer different answers. In this paper, we ask how adults syllabify spoken and written words. We focus on intervocalic consonants like the /ml of demon and the /r/ of erase, asking what factors affect their syllabification.
Initiating Repair With and Without Particles: Alternative Formats of Other-Initiation of Repair in Korean Conversation

This study examines Korean speakers’ practice of initiating repair on the recipient’s talk with and without a subject or object particle and shows that the addition (or deletion) of the particle plays an important role in implementing the action of repair initiation. Initiating repair with a particle ordinarily serves as a harbinger of disagreement, surprise, or disbelief, while initiating repair without a particle functions as an understanding check. The study further suggests possible explanations for how and why the addition of the particle achieves the interactional work of performing a negatively valenced action in Korean. Data are in Korean with English translation.
Benthic-pelagic coupling in the Southern California Bight: Relationships between sinking organic material, diatoms and benthic foraminifera

Abstract In an effort to understand the relationship between surface water processes and seafloor sediment characteristics in the Southern California Bight, opal concentrations, organic carbon weight percent measurements, diatom abundances and assemblages, and living benthic foraminiferal abundances were examined in surface sediments from two sites along the continental margin of Southern California. Although opal and organic carbon weight percentages in the top 1 cm of surface sediments reflect spatial changes in productivity between sites, our results indicate that they are not sensitive indicators of seasonal changes in surface water productivity at either site. The close correspondence between seasonal diatom flux in the adjacent Santa Barbara Basin (SBB), abundances of diatoms indicative of upwelling conditions, and opportunistic benthic foraminifera indicate that there is a rapid, (weeks to months) opportunistic response of the benthic species, Nonionella fragilis , to input from changes in surface water characteristics. These results highlight the close association of surface water conditions and preservable microfauna and flora, and confirm the influence of surface characteristics on seafloor ecosystems in bathyal environments on the California margin. Additional information on these associations will further improve our ability to discern seasonal and spatial changes in paleoproductivity from the geologic record.
About the eigenfunctions of the curl-operator

For simply connected domains we give an elementary proof that curl is selfadjoint and its eigenfunctions are continuously differentiable up to the boundary
Aerosol products, mechanisms, and kinetics of heterogeneous reactions of ozone with oleic acid in pure and mixed particles.

Reactions of O3 with pure and mixed oleic acid particles and bulk solutions were investigated using a thermal desorption particle beam mass spectrometer. The results provide information on the effect of particle matrix on reaction products, mechanisms, and kinetics. The major aerosol products are α-acyloxyalkyl hydroperoxides, secondary ozonides, α-alkoxyalkyl hydroperoxides, and oxocarboxylic acids formed primarily through reactions of Criegee intermediates with products or with particle matrix compounds. For example, it is estimated that for the reaction of pure oleic acid particles with O3 the aerosol products consist of approximately 68% organic peroxides, 28% 9-oxononanoic acid, and 4% azelaic acid. Although the reaction rate of pure oleic acid particles corresponds to an atmospheric lifetime of minutes, reactions in liquid/solid particle matrices can be orders of magnitude slower. The peroxide products are relatively stable when exposed to matrices typical of atmospheric particles, indicating that the lifetimes of these compounds in the atmosphere may be long enough to allow for long-range transport.
On the Quantization of a Unitary Field Theory

In a unitary field theory particles appear not as singularities but as small volumes in which energy and charge of the field are concentrated. In a theory of this nature, which is necessarily non-linear, all properties of the particles, such as their equations of motion, follow from the field equations. It is pointed out in this paper that the non-linearity present in the usual classical field theories is sufficient to permit the existence of particle-like solutions under certain conditions and that it is therefore possible to derive a class of classical unitary theories by postulating that solutions of the usual classical theories are physically admissible only if they are free from singularities. We have studied the quantization of such a theory without specializing the Lagrangian. Momentum (${G}_{\ensuremath{\alpha}}$) and angular momentum (${M}_{\ensuremath{\alpha}\ensuremath{\beta}}$) appear naturally and a relativistic definition of the position (${X}_{\ensuremath{\alpha}}$) of a particle may be given in terms of ${M}_{\ensuremath{\alpha}\ensuremath{\beta}}$ and ${G}_{\ensuremath{\alpha}}$. The commutators of these particle observables (${X}_{\ensuremath{\alpha}},{G}_{\ensuremath{\alpha}},{M}_{\ensuremath{\alpha}\ensuremath{\beta}}$) with each other are calculated and found similar to those postulated in the Snyder formalism which quantizes space-time; these commutators reduce to the usual ones for non-relativistic velocities. (The quantized Born-Infeld theory did not agree with the usual quantum theory of particles even in the non-relativistic limit, because it was not strictly unitary.) The connection between velocity and momentum, and the equation of motion of particles which follow from the field equations are the usual ones. Operators for mass and charge may be defined; these mutually commute and permit the usual classification of the elementary particles according to mass and charge. Magnetic moment and charge commute with the total electromagnetic field. Particle observables and observables describing the external field may not commute in general.
Enantiomeric composition analysis of amphetamine and methamphetamine by chiral phase high-performance liquid chromatography-mass spectrometry.

Abstract N-(Trifluoroacetyl)- l -prolyl- (N-TFA- l -prolyl-) d - and l -amphetamine diastereoisomers were separated by high-performance liquid chromatography and confirmed by an interfaced mass spectrometer system, using the commercially available N-3,5-(dinitrobenzoyl)phenylglycine chiral column. A separation factor of 1.52 and resolution of 3.8 were observed. N-TFA- l -prolyl- d - and - l -methamphetamine diastereoisomers were only partially resolved. The chiral stationary phase-solute interactions were studied by varying the mobile phase (2-propanol in hexane). Results indicate the separation mechanism proceeds via dipolar and hydrogen-bond interactions between the chiral stationary phase and the solute. A modified “dipole-stacking” model takes into account these interactions and explains the difference in separability observed for N-TFA- l -prolyl- d - and - l -amphetamine and N-TFA- l -prolyl- d - and - l -methamphetamine.
Laminar mixed convection in a duct with a backward-facing step: the effects of inclination angle and Prandtl number

Abstract Mixed convective heat transfer results for two-dimensional laminar flow in an inclined duct with a backward-facing step are presented for both the buoyancy assisting and the buoyancy opposing flow conditions. The wall downstream of the step is maintained at a uniform heat flux, while the straight wall that forms the other side of the duct is maintained at a constant temperature equivalent to the inlet fluid temperature. The wall upstream of the step and the backward-facing step are considered as adiabatic surfaces. The inlet flow is fully developed and is at a uniform temperature. The effects of the inclination angle and Prandtl number on the velocity and temperature distributions are reported.
Outcome of Morbid Obesity in the Intensive Care Unit

This was a retrospective chart review of consecutive obese patients admitted to the medical intensive care unit. Patients were divided into 2 groups: mild to moderately obese (group 1, body mass in...
Uranium in the Sikhote-Alin Meteorite and its Relation to the Lead Method of Age Determination

THE ages of lead of Earth and of meteorites are commonly based on the assumption that when these bodies were formed they contained lead of the same isotopic composition1,2. The present differences in the isotopic compositions of the lead in meteorites and also between common terrestrial lead and meteorite lead are due to radiogenic contributions from uranium and thorium since that time.
The Meaning of ברא in Genesis 1:1-2:3

In her 2009 monograph on cognitive linguistics for Biblical Studies Ellen Van Wolde argues that the verb ברא means “to separate” rather than the traditional understanding “to create.” This investigation considers her proposal, Becking and Korpel’s critique of it, cognate and parallel evidence, the semantic domain “creation,” the use of ברא outside of Genesis 1, the use of ברא within Genesis 1, as well its relation to the verb הבדיל. From this discussion, a contextual reading is then proposed which identifies the linguistic traces of the conceptualization of ברא within Gen 1:1-2:3, and it also takes into account script semantics in the association of larger episodes with key vocabulary.
Escape from homeostasis

Many physiological systems, from gene networks to biochemistry to whole organism physiology, exhibit homeostatic mechanisms that keep certain variables within a fairly narrow range. Because homeostatic mechanisms buffer traits against environmental and genetic variation they allow the accumulation of cryptic genetic variation. Homeostatic mechanisms are never perfect and can be destabilized by mutations in genes that alter the kinetics of the underlying mechanism. We use mathematical models to study five diverse mechanisms of homeostasis: thermoregulation; maintenance of homocysteine concentration; neural control by a feed forward circuit; the myogenic response in the kidney; and regulation of extracellular dopamine levels in the brain. In all these cases there are homeostatic regions where the trait is relatively insensitive to genetic or environmental variation, flanked by regions where it is sensitive. Moreover, mutations or environmental changes can place an individual closer to the edge of the homeostatic region, thus predisposing that individual to deleterious effects caused by additional mutations or environmental changes. Mutations and environmental variables can also reduce the size of the homeostatic region, thus releasing potentially deleterious cryptic genetic variation. These considerations of mutations, environment, homeostasis, and escape from homeostasis help to explain why the etiology of so many diseases is complex.
Endovascular management of patients with critical limb ischemia.

Background Although percutaneous intervention (PTA) is considered first-line therapy for peripheral vascular disease in many scenarios, its role in critical limb ischemia (CLI), wherein anatomic disease is more extensive, remains unclear. In the present study, late (5-year) clinical and patency data for PTA in CLI are defined. Methods From January 2002 to December 2007, 409 patients underwent infrainguinal PTA ± stent for CLI (Rutherford IV-VI) of 447 limbs. Primary patency, assisted patency, limb salvage, and survival were assessed using Kaplan-Meier. Predictors of patency, limb salvage, and death were determined using multivariate models. Results Demographics included age (70 ± 12 years old), diabetes (65.8%), and dialysis dependence (13%). The superficial femoral artery was treated in 58% of the patients, 16% were limited to the crural vessels, 38% had multilevel treatment, and stents were placed in 26%. Eighty percent of patients received postprocedure clopidogrel. Mean follow-up was 28 months (0-83). Five-year primary and assisted patency were 31% ± 0.04 and 75% ± 0.04, respectively. Limb salvage at 5 years was 74% ± 0.038. Sixty-three patients had major amputations. Survival at 5 years was 39% ± 0.03. Multivariate analysis identified dialysis dependence (P = .0005; 2.7 [1.6-4.8]), ≤1 vessel runoff (P = .02; 1.5 [1.1-2.0]), and warfarin use (P = .001; 1.7 [1.25-2.3]) as negative predictors of primary patency, but none of these were negative predictors of assisted patency. Dialysis dependence (P = .006; 2.5 [1.3-4.8]), female gender (P = .02; 2.0 [1.1-3.7]), and ≤1 vessel run-off (P = .04; 1.8 [1.0-3.2]) predicted limb loss. Dialysis dependence (P = .0003; 2.3 [1.5-3.5]), diabetes (P = .04; 1.5 [0.5-2.1]), and poor run-off (P = .04; 1.6 [1.2-2.1]) were predictors of mortality. Conclusion Although primary patency is low, excellent limb salvage rates can be achieved in patients with CLI through close follow-up and secondary interventions. These data, and the 12% annual death rate, validate PTA as first-line therapy in patients with CLI.
A simulated annealing algorithm based on a closed loop layout for facility layout design in flexible manufacturing systems

Facility layout design problems in flexible manufacturing systems (FMS) differ from traditional facility design problems and are more difficult to solve because there are more constraints that must be considered (i.e., cell shape, cell orientation, pick-up and drop-off point positions). The focus of this paper is on the closed loop type layout, which is based on a predetermined layout pattern. This layout pattern is commonly found in manufacturing settings since it requires a simplified material handling system configuration and since it facilitates a modular and expandable layout structure. The open-field type layout problem, where there is no predetermined layout pattern, may potentially have a more efficient configuration, since there are fewer restrictions. However, this problem is more difficult to solve and may result in configurations that are not desirable due to the lack of structure or modularity. The procedure developed in this paper improves the efficiency of the closed loop configuration by c...
Lobbying and Relationship Management: The K Street Connection

Even though lobbyists spend millions of dollars in Washington DC, lobbying has been largely ignored by public relations scholars. This study is the first to investigate lobbying from a relational perspective. Health care lobbyists reported that interpersonal relationships were critical in doing their jobs, and that ethics played a key role in maintaining positive organization-public relationships on Capitol Hill. The results also indicate political science scholars have been too issue-focused in their research concerning interest groups in Washington, and that the relational perspective holds promise for future studies of lobbying in both the public relations and political science arenas.
The behavioral- and neuro-economic process of temporal discounting: A candidate behavioral marker of addiction

Addiction science would benefit from the identification of a behavioral marker. A behavioral marker could reflect the projected clinical course of the disorder, function as a surrogate measure of clinical outcome, and/or may be related to biological components that underlie the disorder. In this paper we review relevant literature, made possible with the early and sustained support by NIDA, to determine whether temporal discounting, a neurobehavioral process derived from behavioral economics and further explored through neuroeconomics, may function as a behavioral marker. Our review suggests that temporal discounting 1) identifies individuals who are drug-dependent, 2) identifies those at risk of developing drug dependence, 3) acts as a gauge of addiction severity, 4) correlates with all stages of addiction development, 5) changes with effective treatment, and 6) may be related to the biological and genetic processes that underlie addiction. Thus, initial evidence supports temporal discounting as a candidate behavioral marker. Additional studies will be required in several areas for a more conclusive determination. Confirmation that temporal discounting functions as a behavioral marker for addiction could lead to 1) a screen for new treatments, 2) personalization of prevention and treatment interventions, and 3) the extension of temporal discounting as a behavioral marker for other etiologically similar disorders. This article is part of a Special Issue entitled 'NIDA 40th Anniversary Issue'.
Computational Prediction of Regiospecificity in the [4+2] Diels−Alder Cyclizations between the Iminoborane (F3C)3C−B⋮N−(t-Bu) and Substituted cis-Butadienes

Density functional theory studies comparing the energetics of [4+2] Diels−Alder-like cyclizations of the iminoborane (F3C)3C−B⋮N−(t-Bu) with substituted cis-2-R-1,3-butadienes (R = CH3, NH2, CF3) predict that some reactions will display regiospecificity derived from the transition state barrier heights. When R is an electronically near-neutral group (CH3), the models predict no preference, and so no regiospecificity. When R is an electron-donating group (NH2), the models predict a strong preference for the 5-R-1-bora-2-azacyclohexa-1,4-diene product; that is, the R group favors proximity to the boron atom. When R is an electron-withdrawing group (CF3), the models predict a preference for the 4-R-1-bora-2-azacyclohexa-1,4-diene product, with the R group in proximity to the nitrogen atom. NBO charges provide an explanation for the specificity, in that the atomic charges within the transition state structures match properly for the orientations indicated. Frontier molecular orbital (FMO) coefficients of the ...
Beyond Success: Corporations and Their Critics in the 1990's

Book Review Beyond Success.... emerged from years of joint teaching a course to develop dialogue between future business managers and future theologians. The themes, as put forward in the authors' preface, might be summarized as follows: first, ethics cannot be dealt with in isolation because complex relationships mandate finding a managerial focus; second, new "constituencies" in the corporate-responsibility movement are a major source of concerns; third, managers and their constituencies have much to learn from each other; and, fourth, business firms could and should form partnerships with groups inside and outside the traditional firms.
Identification of adsorbed phenyl (C6H5) groups on metal surfaces: Electron-induced dissociation of benzene on Au(111)

We have investigated thermal and electron-induced chemistry of benzene (C6H6) adsorbed on a Au(111) surface. Thermal desorption of benzene occurs in three desorption peaks: monolayer at 239 K, bilayer at 155 K, and multilayer films at 151 K. Electron-induced dissociation (EID) has been reported previously to selectively break a single C−H bond in molecules present in physisorbed layers and condensed films on metal surfaces, and we investigate whether EID at an incident energy of 30 eV can cleanly prepare adsorbed phenyl (C6H5(a)) groups on the surface at low temperatures (∼90 K). We use infrared reflection−absorption spectroscopy (IRAS) to show unequivocally that adsorbed phenyl groups can be formed by this procedure. Phenyl groups on Au(111) are bound with the molecular (ring) plane perpendicular to the Au surface plane, with the molecular z-axis tilted away from the surface normal. In contrast to previous reports of the chemistry of phenyl groups adsorbed on Cu(111) and Ag(111) surfaces, we find that a...
The Influence of Market Structure on Technological Progress

I. Single unexpected innovation, free entry, 556. — II. Single unexpected innovation, blocked entry, 560. — III. A foreseen flow of innovations, blocked entry, 567. — IV. A foreseen flow of innovations, free entry, 568. — V. Welfare appraisal, 572. — VI. Limited availability and the patent problem, 575.
Perforated appendicitis in children: equal access to care eliminates racial and socioeconomic disparities.

Purpose: The aim of the study was to determine whether equal access to health care eliminates racial and socioeconomic disparities in appendicitis outcomes. Methods: A review of patients younger than 18 years treated for appendicitis for a decade was performed. Outcomes were appendiceal perforation (AP) rate and length of hospitalization (LOH). Independent variables included racial status, annual median per capita income, and parental education level. Results: Seven thousand two hundred forty-seven patients were identified (mean age, 11.6 years; 62% male). The adjusted odds ratio (OR) for AP was similar in blacks, Hispanics, and Asians compared to whites. The OR for AP was similar in high- and medium-income families compared to low-income families. The OR for AP was similar in high and medium parental education levels compared to low parental education levels. The adjusted LOH was longer in blacks and similar in Hispanics and Asians compared to whites. The LOH was shorter in high- and similar in medium-income families compared to low-income families. The LOH was similar in all parental education levels. Conclusion: Lower socioeconomic background and minority status did not correlate with higher appendiceal perforation rates or a clinically longer LOH in children with equal access to care. The previously reported disparities in pediatric appendicitis outcome are preventable with equal access to care.
Macroscopic Capacity Model with Individual Sector Closing Speed Estimates

Reliable airspace capacity estimates are important both for operational air traffic management and for airspace design. Air traffic management relies on manual procedures. Hence, controller workload determines the capacity of most sectors. Yet the current operational model for estimating capacity in United States airspace does not account for workload from conflict avoidance tasks. Aircraft closing speeds and airspace separation standards determine the rate of aircraft conflicts. Numerically, conflict workload intensity is the product of the conflict rate and the mean controller time required to service a conflict. As workload intensity approaches unity, the sector reaches capacity. We determine unknown model parameters by fitting capacity calculations against peak traffic observations for en route sectors. The result is an analytical model for capacity that is more accurate than the current operational model. The mean closing speed of all pairs of aircraft in a volume of airspace determines the conflict rate. This paper reports an effort to refine the conflict component of the model by replacing its original global closing speed estimate with local traffic-based closing speed estimates for individual sectors. Exact calculation of mean closing speed requires full position and velocity information for all flight tracks. The database that we used to obtain the peak traffic counts includes initial heading, speed, and altitude fields for all traffic entering a sector. Without positional coordinates and intersector track information, these data fields provide only crude closing speed estimates. We examined these estimates as possible indicators of sector route and altitude complexity in the New York Center. Individual sector closing speed estimates based on these observations did not improve the model fit for the 30 New York sectors.
14 Financial liberalization and corporate debt maturity in Thailand, 1993-97

Excessive short-term debt is thought to be one of the major causes of the Asian financial crisis, and this paper documents the changes in the maturity of corporate debt in Thailand during a period of rapid integration with international capital markets. Using data from publicly-traded Thai corporations for the period 1993-97, we find that the evidence is weak at best that financial liberalization brought about by globalization reduced the maturity of corporate debt contracts, and the evidence may in fact support an increase in maturity. This result casts some doubts on the generality of the idea that financial liberalization created the short-term debt problem.