cssi/SciSciGPT-SciSciNet huggingface dataset:
Pyrolysis kinetics of char forming polymers

A mechanistic pyrolysis model for char forming polymers is solved analytically and evaluated experimentally. Under conditions of flaming combustion the coupled rate equations for thermal degradation products and reactants reduce to a single-rate law for the residual mass if production of an intermediate species is the rate-limiting step. Exact results are obtained for the mass loss history of a pyrolyzing polymer which include an equilibrium char yield whose value depends only on the relative rates of gas and char formation at a particular temperature. Reaction rate constants for thermolysis of chemical bonds, gas production and char formation are determinable from parametric fits of the mechanistic charring model to thermogravimetric data. Predictions of the nonisothermal mass loss during constant heating rate experiments are in agreement with experimental data over the expected range of validity.
Identification of a monoclonal antibody which can distinguish between two distinct species of the type I receptor for insulin-like growth factor.

Summary A monoclonal antibody was identified which equally inhibits 125 1-labeled insulin and insulin-like growth factor I (IGF-I) binding to their respective receptors in human IM-9 lymphoid cells and solubilized placenta receptor preparations. In contrast, this monoclonal antibody inhibits insulin but not IGF-I binding to human hepatoma (HepG2) cells, fibroblasts and muscle cells. These results indicate that there are two distinct species of the type I insulin-like growth factor receptor (which we have named type IA and type IB) and suggest that this monoclonal antibody may be useful in determining whether different biological effects are mediated through these two receptors.
Vacuum-formed prostheses. I. A temporary fixed bridge or splint

Laboratory and clinical phases of a technic for a temporary fixed bridge or splint that uses a small vacuum-forming machine built specifically for the dental office are described. Other applications are also listed.
Construction of a pressure-resistant flow cell of high efficiency for scintillation counting with accelerated amino acid analysis.

Abstract The construction of a plastic cell for seintillation flow counting is described, the efficiency of which is higher than those of several other cells examined. This result is due in part to the “flattened” design of the fluor-containing chamber, permitting a relatively large number of scintillations to be detected by the phototubes. A salient feature of this cell is its resistance to leakage at high pressures, made possible by the use of a seamless plastic cylinder as an external casing. The cell has been adapted to an accelerated system of amino acid anlysis.
The impact of multiple biopsies on outcomes of nerve-sparing robotic-assisted radical prostatectomy

Active surveillance of prostate cancer patients involves subjecting them to multiple prostate biopsies, and we sought to investigate the effects of this on functional outcomes after robotic-assisted radical prostatectomy (RARP). Between May 2009 and December 2009, 367 patients who consecutively underwent RARP by a single surgeon were divided into two groups, one that had single prostate biopsy and another multiple biopsies before RARP. The groups were matched for significant clinicopathologic preoperative variables, and only premorbidly potent low-risk cases that underwent nerve sparing were included. This left 50 and 23 patients for analysis in the single and multiple biopsy groups, respectively. The primary endpoint was potency and continence at 3 and 6 months after surgery. We found continence rates of 84% (83%) and 94% (96%) for single (multiple) biopsy groups at 3 and 6 months, respectively (P=0.88, P=0.77). Multiple biopsy patients had worse postoperative erectile function at 6 months (57% versus 80%, P=0.03). Men subject to multiple preoperative biopsies are more likely to become impotent postoperatively than those who undergo surgery after a single biopsy. This should be borne in mind when counseling men regarding repeat biopsy as part of an active surveillance strategy.
Effects of cytosolic NADH/NAD+ levels on sarcoplasmic reticulum Ca2+ release in permeabilized rat ventricular myocytes

In the heart ischaemic conditions induce metabolic changes known to have profound effects on Ca(2+) signalling during excitation-contraction coupling. Ischaemia also affects the redox state of the cell. However, the role of cytosolic redox couples, such as the NADH/NAD(+) redox system, for the regulation of Ca(2+) homeostasis has remained elusive. We studied the effects of NADH and NAD(+) on sarcoplasmic reticulum (SR) Ca(2+) release in permeabilized rat ventricular myocytes as well as on Ca(2+) uptake by SR microsomes and ryanodine receptor (RyR) single channel activity. Exposure of permeabilized myocytes to NADH (2 mm; [Ca(2+)](cyt)= 100nm) decreased the frequency and the amplitude of spontaneous Ca(2+) sparks by 62% and 24%, respectively. This inhibitory effect was reversed by NAD(+) (2 mm) and did not depend on mitochondrial function. The inhibition of Ca(2+) sparks by NADH was associated with a 52% decrease in SR Ca(2+) load. Some of the effects observed with NADH may involve the generation of superoxide anion (O(2)(-).) as they were attenuated to just a transient decrease of Ca(2+) spark frequency by superoxide dismutase (SOD). O(2)(-). generated in situ from the xanthine/xanthine oxidase reaction caused a slowly developing decrease of Ca(2+) spark frequency and SR Ca(2+) load by 44% and 32%, respectively. Furthermore, in studies with cardiac SR microsomes NADH slowed the rate of ATP-dependent Ca(2+) uptake by 39%. This effect also appeared to depend on O(2)(-). formation. Single channel recordings from RyRs incorporated into lipid bilayers revealed that NADH (2 mm) inhibited the activity of RyR channels by 84%. However, NADH inhibition of RyR activity was O(2)(-).-independent. In summary, an increase of the cytoplasmic NADH/NAD(+) ratio depresses SR Ca(2+) release in ventricular cardiomyocytes. The effect appears to be mediated by direct NADH inhibition of RyR channel activity and by indirect NADH inhibition (O(2)(-). mediated) of SR Ca(2+)-ATPase activity with a subsequent decrease in SR Ca(2+) content.
Social desirability effects in male prisoners

Abstract Validity of the Jacobson-Kellogg Self-Description Inventory—Revised (SDI-II) as a multidimensional measure of social desirability (SD) was examined in a sample of male prisoners. Results indicated that the SDI-II may be considered as a unitary construct in this sample and the total score serves as a highly reliable and valid measure of SD influence. High SD condition subjects scored significantly higher on each SDI-II subscale than low SD condition subjects suggesting that self-presentation in socially desirable ways is latent or masked without a situation to elicit the response. Blacks scored significantly higher than whites on each SDI-II subscale. Additional findings are presented.
Colonoscopy with the variable stiffness colonoscope.

During colonoscopy, sharp angulations and fixation of the bowel increase the difficulty of the procedure. Excessive “looping” of the bowel implies that the force of scope insertion is transferred to the colon wall or to its mesenteric attachment instead of to the forward advancement of the leading tip of the colonoscope. Stiffer, large-caliber, standard adult colonoscopes are thought to better allow for “loop reduction” and sustained “straightening.” This feature may be referred to as column strength. Column strength prevents the instrument from buckling when the proximal end is being pushed and conveys elasticity to promote and maintain straightening when the scope is pulled back to remove loops. However, large-caliber scopes may be less capable of traversing sharply angulated and narrowed segments. Floppy (non-rigid), small-caliber scopes, such as pediatric colonoscopes and push enteroscopes, may better traverse excessively angulated sections of colon than standard adult colonoscopes.1,2 However, the exaggerated flexibility of small caliber scopes less readily enables loop reduction and sustained straightening of the bowel. Further, smallcaliber scopes also have a smaller suction/accessory channel that may impede clearance of residual fecal material and poses limitations on device use. The mechanical characteristics of the insertion tube may be the most substantial instrumentrelated variable in determining speed, comfort, and efficiency of colonoscopy. Ideally, colonoscopists want an insertion tube that is highly flexible yet has high column strength. The variable stiffness colonoscope (VSC) (Olympus America Corp., Melville, N.Y.) is a modified colonoscope equipped with a mechanism enabling the operator to adjust the relative flexibility or stiffness of the instrument’s insertion tube. The variable stiffness component may then selectively combine the flexibility of a small-caliber scope with the stiffness of a standard colonoscope. Intended for routine diagnostic and therapeutic use, the VSC was developed to enhance the performance of colonoscopy.
Regulation of granulocyte‐macrophage colony‐stimulating factor and interleukin 3 expression

Granulocyte-macrophage colony stimulating factor (GM-CSF) and interleukin 3 (IL-3) are multilineage acting hematopoietic growth factors which have overlapping but distinct biological properties. Cellular sources of IL-3 are confined to activated T cells, natural killer (NK) cells, mast cells and possibly megakaryocytes, while these cells and activated macrophages, fibroblasts and endothelial cells are important sources of GM-CSF. In vitro studies have implicated both cytokines in the autocrine growth of human myeloid or murine mast cell leukemias. The human GM-CSF and IL-3 genes map to the long arm of chromosome 5, show similar genomic structures, and share several conserved elements in their 5' and 3' flanking regions. The promoters of these genes contain a variety of positive and negative regulatory regions, and the level of expression of these genes is controlled by both transcriptional and post-transcriptional mechanisms.
Applications of metal and semiconductor nanoclusters as thermal and photo-catalysts

We discuss studies of photo and thermally driven reactions which illustrate the unique catalytic features of nanoclusters which may be of great technical utility. The application of photocatalysts of nanosize MoS2 to oxidize organic pollutants to CO2 is discussed. Nanosize MoS2 shows improved rates of oxidation of organics such as phenol compared to alternative bulk powders such as TiO2 or ZnO. Selective hydrogenation of pyrene using both dispersed and supported nanoclusters of Rh, Pt, and Pd is also discussed.
Multi-scale features in recent development of enzymic biocatalyst systems.

Functional relation among elements of different size scales in a system is probably a main challenge across the areas of the science of engineering ever since their emergence. Multi-scale time and size correlation for description and prediction of complex systems, however, has been systematically examined only recently with the aid of new computational tools. In the pursuit of efficient and sustainable chemical processing technologies, people have seen a growing emphasis on synthetic biotechnology in recent RD they also have to compete against alternative chemical technologies in terms of costs and efficiency. Accordingly, enzymic biocatalyst systems are being tackled dynamically at all size levels through efforts ranging from molecular level protein engineering and modification, nanoscale structure fabrication, and microenvironment manipulation to the construction of microchip devices and macroscopic industrial bioreactors and devices. These efforts are probably still on a case-to-case trial basis without much consideration of cross-scale correlations. Discovering, understanding, and controlling of the common features that relate functions of biocatalysts at different size scales may eventually be realized in future.
Disappearance of nitrate under transient conditions in columns of soil

Abstract Previously a rapid reduction of NO3− was obtained in soil columns with continuous flow, before the establishment of steady state conditions. This initial behavior was not a function of flow rates. In order to determine what influence NO3− concentrations might have on transient and steady state rates, of NO3− loss, small soil columns (2·5 cm i.diam × 10 cm length) were infiltrated with 0, 100 and 1000 μg ml−1 NO3−N and the effluents were analyzed daily for NO3− and NO2−. Several days after an apparent steady state had been obtained, as determined by the effluent NO3− concentration, the influent NO3− concentrations were changed to 100 μg ml−1 NO−N in some of the columns. All columns showed transitions to new and identical steady state of NO3− loss from flowing solutions. Evidently the initial transient kinetics are primarily determined by some solubilization of organic matter during rewetting of air dry soil and subsequent steady states are dependent on lesser available organic matter.
Central nervous system trauma: Management of concussions in athletes

The care of athletes with concussions is challenging because each patient has different symptoms. An athlete should never be returned to play until completely asymptomatic. Classification systems for concussions are not based on scientific evidence and represent some practitioners' best guess at what is safe for young athletes. Many experienced team physicians believe they can allow an athlete to play safely if there are no symptoms at rest and no symptoms with increasing intensity of exercise. Abbreviated neuropsychological testing and balance tests show promise for use in the field to increase the sensitivity of our neurological evaluation on injured athletes. Any neuropsychological or balance evaluation is more helpful if baseline data is collected on athletes before they are injured.
On the need for human-based empirical validation of techniques and tools for code clone analysis

Code clone analysis techniques and tools are popular topics among the software engineering research community. Many studies draw conclusions solely based on an analytical analysis. These claims focus primarily on tool performance in terms of portability, scalability, robustness, precision, and recall. However, these types of analytical studies cannot adequately evaluate the behavior of the developers while using the tools. Human-based empirical studies are complementary to studies based on analytical data because they provide direct insight into developer behavior. In this paper we argue for the need for more humanbased empirical studies in the area of code clone analysis techniques and tools.
Dose-dependent effects of submicrometer sulfuric acid aerosol on particle clearance from ciliated human lung airways

We previously showed that 1 hr exposures to submicrometer sulfuric acid (H2SO4) aerosol at 100 and 1000µg/m3 altered the bronchial mucociliary clearance of monodisperse 7.6 µm MMAD99mTc-labelled ferric oxide (Fe2O3) in healthy, nonsmoking humans. The 7.6 µm particles were primarily deposited in the larger bronchial airways, where submicrometer H2SO4 has very little deposition. To determine the extent that submicrometer H2SO4 aerosol affects clearance from the more distal ciliated airways, we measured the clearance of a monodisperse 4.2 µm MMAD Fe2O3 aerosol in eight other healthy nonsmoking subjects. A greater fraction of 4.2 µm particles deposited in distal conductive airways. Bronchial mucociliary clearance was slower following 1 h nasal H2SO4 inhalations at 100,300 and 1000 µg/m3 than after sham exposures, while mucociliary transport rates within the trachea and indices of respiratory mechanics were unchanged. A comparison of the effects of 1 h exposures at 100 µg/m3 on the clearance of 7.6 and 4.2 µm ...
Anomalous phonon intensities in the Raman spectrum of disordered CsMg1−xCoxCl3

Abstract The five Raman-active k = 0 phonons have been measured at low temperatures and for a range of x in the disordered lattice CsMg1-xCoxCl3. While the E2ga, E2gb, E2gc and A1g modes at 55.0, 132.0, 189.0 and 255.0 cm−1 for x = 0 exhibit normal one-mode behaviour, the intensity of the E1g phonon at 127.5 cm−1 has a most unusual concentration dependence which requires a new theory.
PALEOZOIC LEPOSPONDYL AMPHIBIANS

The lepospondyls are urodele-like amphibians of the Paleozoic Era, some of which have been considered ancestral or closely related to reptiles or modern amphibians. Their origin is enigmatic, and the earliest occurrences reveal a long-established division into three contrasting orders: the serpentine aistopods, the newt-like nectrideans and the deceptively reptilian microsaurs. The Subclasses Lepospondyli and Labyrinthodontia are not so disparate as to indicate a polyphyletic origin for the Amphibia. Which subclass gave rise to the present-day Lissamphibia is still disputed, but superficial similarities between lepospondyls and lissamphibians cannot mask the fundamental discrepancies in temporal range and morphology and (apparently) in life history as well.
The Argonne thirty-foot spectrograph

Abstract The new Argonne spectroscopy laboratory includes a thirty-foot Paschen-Runge mounting, utilizing either plates or photocells. Construction details are presented of note-worthy items, e.g., the interchangeable fixed slits, grating holders, and source optical benches. For photoelectric detection the exit slit assembly is pulled along the continuous plate rail by a selsyn drive. Optimum masking of the grating was established by scanning Hg198 lines. Typical spectra are reproduced.
Mussolini's Italy: Life Under the Fascist Dictatorship, 1915–1945 – By R. J. B. Bosworth

This volume devoted to a study of Mussolini's Italy should be of particular interest to professional historians. It speaks to the nature of what historians are understood to be doing when they prac...
Zooarchaeological Evidence of Prairie Taxa in Central Missouri during the Mid-Holocene

Previous studies report that remains of prairie taxa are common in western Missouri archaeological sites. There is no reported evidence of prairie taxa, such as Bos bison, from sites within the northern Ozark Highlands of Missouri. New data indicate that prairie taxa inhabited the area during the warm and dry mid-Holocene (8500–5000 14C yr B.P.). Evidence suggests prairie taxa were farther east and south than previously documented in central Missouri and underscores the importance of biogeographic data in studies of prehistoric environments.
The evolution of firm networks: from emergence to early growth of the firm

This paper addresses whether cohesive networks of socially embedded ties or sparse networks rich in structural holes are more conducive to the success of new firms. We propose that the networks of emerging firms evolve in order to adapt to the firm's changing resource needs and resource challenges. As firms emerge, their networks consist primarily of socially embedded ties drawn from dense, cohesive sets of connections. We label these networks identity based. As firms move into the early growth stage, their networks evolve toward more ties based on a calculation of economic costs and benefits. This shift from identity-based to more calculative networks is manifested in the evolution of the firm networks: (1) from primarily socially embedded ties to a balance of embedded and arm's-length relations; (2) from networks that emphasize cohesion to those that exploit structural holes; and (3) from a more path-dependent to a more intentionally managed network. Thus, this paper suggests that both cohesive and sparse networks are conducive to firm performance when they are aligned with and address firms' evolving resource challenges. Copyright © 2001 John Wiley & Sons, Ltd.
Trisomy 6 in basal cell carcinomas correlates with metastatic potential: a dual color fluorescence in situ hybridization study on paraffin sections.

BACKGROUND Most basal cell carcinomas (BCCs) are indolent lesions; a few become locally aggressive or even metastatic. Little is known about the molecular and genetic alterations in this malignant transformation. Conventional karyotyping in BCC has revealed a high frequency of nonclonal, structural rearrangements, with few cases that show multiple, unrelated, small clones suggestive of a multicellular origin. Trisomy 6 was described recently in a few BCCs, but the biologic significance of the appearance of trisomy 6 in BBCs was not clear. METHODS Thirty cases including 4 metastatic, 4 locally aggressive, and 22 conventional nonaggressive BCCs were studied. Fluorescence in situ hybridization (FISH) was performed on 4 μm tissue sections, using α-centromeric enumeration probes for chromosome 6 (SpectrumGreen, Vysis Inc., Downers Grove, IL) and chromosome 4 (SpectrumOrange, Vysis Inc., Downers Grove, IL, used as disomic cell control). Trisomy 6 was semiquantitated within tumor cells and nonneoplastic cells in each case. RESULTS Trisomy 6 was identified in all 4 metastatic BCCs within tumor cells and in corresponding BCCs at the primary cutaneous site in 2 of these 4 cases. Two locally aggressive BCCs, 1 of which had preceding radiation exposure, also showed trisomy 6. All nonaggressive BCCs and nonneoplastic cells were disomic for chromosome 6. CONCLUSIONS Trisomy 6 has been identified as a cytogenetic aberration representative of tumor cells in aggressive and metastatic BCC. None of the nonaggressive BCCs in this study demonstrated trisomy 6. Acquisition of trisomy 6 by tumor cells in BCC may lead to the emergence of metastatic potential. Additional studies to define the underlying mechanisms may be valuable in preventing aggressive behavior in BCC. Cancer 2001;91:1927–32. © 2001 American Cancer Society.
NEUTROPENIA IN THE PEDIATRIC POPULATION AND ITS ASSOCIATION WITH INFECTION

Neutropenia, defined as an absolute neutrophil count <1000, occurs frequently in the general pediatric population. Its incidence and association with infection, both self-limited and more serious, have not been well described.
IN SITU SOLID-STATE NMR STUDIES OF TRICHLOROETHYLENE PHOTOCATALYSIS : FORMATION AND CHARACTERIZATION OF SURFACE-BOUND INTERMEDIATES

In situ solid-state NMR methodologies have been employed to investigate the photocatalytic oxidation of trichloroethylene (TCE) over two TiO2-based catalysts, Degussa P-25 powder and a monolayer Ti...
Electronic fuel injection techniques for hydrogen powered i.c. engines

Numerous studies have demonstrated the advantages of hydrogen as a fuel for Otto Cycle engines due to high thermal efficiency and low exhaust pollutant levels. Characteristic of hydrogen engine operation using premixed intake charge formation is a problem of pre-ignition resulting in an intake manifold “backfire”. Additional problems include high NOx production when using certain equivalence ratios and power output degradation due to low fuel energy/volume density. Techniques for direct and port fuel injection are discussed as means for overcoming these problems. Emphasis is placed on the need for total engine control, integrating control of fuel injection, ignition timing, intake air throttling, and vehicle subsystems within a central electronic unit. An electronically actuated fuel injection valve and a prototype electronic control system are developed. These are applied in port and direct injection system geometries, and evaluated in engine testing. System effectiveness and feasibility are discussed.
Deformation behavior and failure mechanisms in particulate reinforced 6061 Al metal-matrix composites

The deformation behavior and failure mechanisms in 6061 Al alloy matrix particulate composites were examined via uniaxial tension and compression tests. The dependence of the deformation behavior on the matrix properties was studied by varying the heat treatment conditions (T4 and T6) of the matrix. The influence of the heat treatment condition on the deformation behavior of the composite was observed to be stronger than the influence of particle shape, size and volume fraction. In both tension and compression testing, composites in the T4 condition experience a larger degree of work-hardening as compared to the materials in the T6 condition. When subject to uniaxial tension, the deformation and failure behavior is strongly dependent on the relative strengths of the particles and matrix, and on the work-hardening behavior of the matrix, which is influenced by heat treatment condition. In compression, the particles merely act as obstacles to the flow of the matrix, whereas in tension they influence the failure mechanism of the composite.
Energy efficient routing with delay guarantee for sensor networks

The paper presents a routing algorithm that maximizes the lifetime of a sensor network in which all data packets are destined for a single collection node. Lifetime is maximized by adjusting the number of packets traversing each node. The adjustment is carried out by transmitting over alternative routes. The first part of the paper assumes that the worst case delay resulting from energy efficient routing is less than the maximum tolerable value. Ignoring the delay constraint of the network, the routes are selected as the solution to a linear programming (LP) problem in which the objective is to maximize the minimum lifetime of each node. The solution is implemented in a centralized algorithm, and then approximated by an iterative algorithm based on least cost path routing, in which each step is implemented efficiently in a distributed manner. The second part of the paper incorporates delay guarantee into energy efficient routing by constraining the length of the routing paths from each sensor node to the collection node. Simulations reveal that the lifetime of the network increases significantly by optimal routing, and including delay constraint in energy efficient routing improves the network performance since the delay of the network keeps increasing as the delay constraint is relaxed beyond the value at which the optimal lifetime is achieved.
Mutagenicity of Sediments from the Detroit River

Abstract Sediment samples from 30 sites in the lower Detroit River and one site in Lake Michigan were extracted with organic solvent and were tested for mutagenicity in the Ames test. Without metabolic activation, sediment samples were either non-mutagenic or weakly mutagenic. With metabolic activation, mutagenic responses (defined as doubling of the spontaneous mutation rate at one or more concentrations of organic extract) were observed in 16 of 31 samples. Mutation rates ranged from 20 to 370 histidine positive revertants per mg of organic extract. These results demonstrate the existence of compounds in sediments of the Detroit River that can be activated to mutagens. The sediments thus are a potential source of mutagenic and possibly carcinogenic compounds for fish and other organisms.
Inhalant use and delinquent behavior among adolescents: a comparison of inhalant users and other drug users.

AIMS: To evaluate the association between inhalant use and delinquent or criminal behavior. DESIGN: A large statewide sample of high school students participated in a survey on drug use. Five groups were identified based on reported drug use: inhalant experimenters, other drug experimenters, inhalant users, other drug users and non-users. Inhalant users were compared with other drug users and inhalant experimenters with other drug experimenters on three measures of problem behavior. PARTICIPANTS: Over 13,000 students in grades 7-12 participated in the 1993 survey on drug use. MEASUREMENTS: Three measures of problem behavior: drinking and drug-taking, "trouble behavior" and minor criminal activity. FINDINGS: Among upper (9-12) grade level students only, both inhalant users and inhalant experimenters reported more minor criminal activity than other drug users and other drug experimenters, respectively. A similar trend was noted for trouble behavior. The same was not found for drinking and drug-taking behavior. CONCLUSIONS: The findings suggest that inhalant use is categorically different from other drug use, and that it has more in common with general delinquency than with general drug use. Prevention and treatment strategies should take this into consideration. Language: en
The impact of performance cues on leader-behavior ratings: the role of selective information availability and probabilistic response bias

Abstract Previous research has demonstrated that performance cues can significantly influence raters' responses on leader-behavior rating questionnaires. The purpose of the present study was to explore the cognitive mechanisms that mediate this influence. Subjects watched a videotape of a problem-solving group and later rated the group leader's behavior. Perceptions of the group's performance were manipulated both before (preobservation) and after (postobservation) subjects watched the tape. Both manipulations affected the leader-behavior ratings. Analytic procedures borrowed from signal detection theory suggest that the preobservation performances cue effects were mediated by selective encoding of leader-behavior information in memory, while the postobservation effects were mediated by probabilistic response biases. Selective memory retrieval, on the other hand, did not seem to play a role. The implications of these results for developing strategies to overcome the confounding influence of performance cues on leader-behavior ratings are discussed.
Preparation of 3-azetidinols with non-bulky 1-alkyl substituents

Cyclization of either the tetrahydropyranyl or trimethylsilyl ether of 1-(alkylamino)-3-chloro-2-propanols 1 followed by cleavage of the azetidinyl ether provides a general method for the preparation of 1-alkyl-3-azetidinols. Unhindered amines provide a more facile preparation of derivatives of 1, or its ethers, than do hindered amines, while hindered derivatives of 1 undergo more facile ring closure.
Behavioural gustatory responses of adult cockroaches, Periplaneta americana to d and l amino acids

Abstract This study explored behavioural gustatory responses of the adult cockroach, Periplaneta americana to d and l -amino acids. Insects were mounted and tested using a modified Frings method. Results indicate: (1) Cockroaches responded positively to l -amino acids but not to most d -amino acids. (2) Sodium-buffered solutions generally enhanced gustatory responses to l -amino acids, particularly to valine, leucine, isoleucine, methionine, phenylalanine and tryptophan, with concomitant decreases in thresholds. Observed enhanced responses were shown to be due to some type of sodium-ion involvement. The d -enantiomers were not tested in buffer. (3) On the other hand, responses to l -proline and hydroxy- l -proline were not affected by the buffer. (4) No overall amino acid structure-activity relationship could be determined.
Withholding and withdrawal of life support from surgical neonates with life-threatening congenital anomalies

Abstract We evaluated why and how life support was withheld or withdrawn in surgical neonates. During the study period, January 1988 through December 1991, 529 neonates were admitted, 52 of whom died (10%). Twenty-eight deaths were due to the underlying disease. The other 24 patients died because treatment was withheld or withdrawn. In 15 of 24 (group A, mean stay 9.2 ± 9.1 days) treatment was initially started but later withdrawn (1315) because of the severity of congenital anomalies alone (712) or congenital anomalies associated with chromosomal anomalies (512). In 9 of 24 (group B, mean stay 20.3 ± 17.3 days) treatment was withdrawn because of serious complications. In all cases often lengthy discussions have led the doctors and nurses together with the parents to chose unanimously for withdrawal of treatment. Mechanical ventilation was the intervention most frequently withdrawn (1015 group A, 99 group B). Vasoactive and other drugs were withheld in 5 patients of group A. Sedatives and analgetics were administrated as supportive care permitting the child to die in a humane way, 17 in the lap of a parent and 7 in the lap of a nurse. We conclude that life-sustaining care is withheld or withdrawn relatively frequently from patients at our ICU. Such decisions are ethical ones, taken in the light of professional and technical expertise. Evaluation of withholding or withdrawal of treatment is difficult but necessary to evolve appropriate decision-making procedures and to formulate humane standards of intensive care. Discussions about decision-making with regard to forgoing life-support should form an important part of the continuing education of doctors and nurses who are involved with treatment of newborn infants with congenital anomalies.
Discovery of the palaeo-Indus delta-fan complex

The Indus River carries sediments from the western Himalaya and deposits some of these as channel and floodplain sediments or molasse. The rest of its load forms the Indus delta at the margin of the Indian Ocean. The Indus delta passes some of its sediments to be deposited as Indus submarine fan turbidites. Thus, as elsewhere, Himalayan molasse, delta, and fan deposition are related hi tune and space. However, when we examine fluvial and marine age-range data of the older Indus deposits, in terms of this sedimentary assemblage, a major portion of its marine record is missing. The oldest known molasse along the Indus suture zone, and hi the foredeep are middle Eocene and late Palaeocene hi age, respectively. A recent synthesis of sedimentation in the northern Indian Ocean, however, shows that turbidite sedimentation started around early Miocene in the modern Indus fan, and even later in the Bengal fan. Where are the Palaeogene Indus delta and fan sediments? We suggest herein that these are preserved as the Palaeogene siliciclastic Khojak Formation hi the Katawaz Basin and eastern Makran. The modern Indus River is 2900 km long (Coumes & Kolla 1984) and has 30 000 m 3 s − 1 discharge (Milliman et al. 1984) in summer (Fig. 1), twice that of the Mississippi River. The annual suspended sediment load (Wells & Coleman 1984) varies between 395 and 435 x 10 3 t, almost equal to that of the Mississippi. The existence of the middle Eocene to middle Miocene Indus molasse along the
Evidence that healthy human gingiva contains functionally heterogeneous fibroblast subpopulations

Abstract Six mass cultures of human fibroblasts derived from a single biopsy of a normal gingival papilla tip were studied with regard to their protein, collagen and glycosaminoglycan synthesis in vitro, using incorporation of radiolabelled substances. The proliferation rates, replicative life-spans and cell-size distributions of these mass cultures were determined. There were significant differences among the 6 cultures and these differences persisted throughout numerous cull replications in vitro. It is suggested that functional heterogeneity exists among phenotypically stable fibroblast subpopulations or subpopulation mixtures from normal tissue. The concept of participation of fibroblast subpopulations in disease pathogenesis is supported by these preliminary findings.
Functional studies of the small pulmonary arteries

Abstract Based upon catecholamine histofluorescence and capacity for neuronal uptake of norepinephrine, extra- and intrapulmonary arteries are well supplied by adrenergic nerves. In isolated segments of arteries larger than 0.6 mm in diameter, these nerves release sufficient transmitter to cause vasoconstriction. However, in arteries smaller than 0.6 mm in diameter, both nerve stimulation and NE application elicited either very small responses or none at all. The vascular smooth muscle was responsive under the experimental conditions, since all arterial segments constricted in response to 5HT, histamine, and KCl, and the maximal effects of the three agents were equal. It is not yet known whether the poor reactivity of small arteries to NE and adrenergic nerve stimulation is peculiar to the rabbit pulmonary vascular bed, and whether segments of the pulmonary vascular tree farther downstream than those studied are more reactive to sympathetic stimulation. Possibly the sympathetic control of vascular tone is restricted to the relatively large arteries. Reduction in the magnitude of the contractile response, rather than sensitivity to NE, appears to account for the diminution of vessel response as the vessel becomes smaller. It is speculated that, in the pulmonary vasculature through which the output of the right heart passes to the left, an extensive arterial constriction accompanying sympathetic discharge resulting in major changes in blood flow is undesirable.
Intensity of Occupational Training: Its Effects on Subsequent Labor Market Experiences

Abstract This paper argues that public and proprietary, postsecondary occupational programs differ on an important dimension: intensity of occupational training, that is, the proportion of the curriculum devoted to providing job-specific skills. The study examined the labor market implications of matriculating in programs differing in intensity of occupational training. The compensation received by the graduates from the occupationally less intensive community college programs grew at a significantly faster rate relative to the income of the alumni from the more intensive proprietary schools. Only minor differences existed, however, between the subsamples with respect to the other variables used to examine their labor market experiences.
How did humans first alter global climate

The article discusses the history of man's influence on the global climate. The scientific consensus that human actions first began to have a warming effect on the earth's climate within the past century has become part of the public perception as well. Now, though, it seems our ancient agrarian ancestors may have begun adding carbon dioxide (CO2) gases to the atmosphere many millennia ago, thereby altering the earth's climate long before anyone thought. New evidence suggests that concentrations of CO2 started rising about 8,000 years ago. Some 3,000 years later the same thing happened to methane, another heat-trapping gas. Human activities tied to farming--primarily agricultural deforestation and crop irrigation--must have added the extra CO2 and methane to the atmosphere. These activities explained both the reversals in gas trends and the ongoing increases right up to the start of the industrial era. Since then, modern technological innovations have brought about even faster rises in greenhouse gas concentrations. Cores of ice drilled in the Antarctic and Greenland ice sheets have provided extremely valuable evidence about the earth's past climate, including changes in the concentrations of the greenhouse gases. INSETS: Overview/Early Global Warming;Human Disease and Global Cooling.
Chronology of ophiolite crystallization, detachment, and deeper parts of subduction zones. emplacement: Evidence from the Brooks Range, Alaska

{sup 40}Ar/{sup 39}Ar data from early Middle Jurassic ophiolites (187-184 Ma) in the western Brooks Range, Alaska, indicate that detachment - related metamorphism occurred {approximately}20 m.y. after crystallization and {approximately}20 m.y. before emplacement onto the Arctic Alaska margin. High-temperature metamorphic rocks along the basal surfaces of many ophiolites have ages that are contemporaneous with ophiolite crystallization, suggesting that detachment and thrust faulting occur while the lithosphere is young ({lt}10 Ma) and relatively hot. From these relations it has been generally assumed that detachment and initial overthrusting of oceanic lithosphere occur near the site of generation, such as a marginal basin or mid-ocean ridge. The new data from the Brooks Range ophiolites confirm previous indications that some ophiolites have much longer intervals between crystallization, thrust-related metamorphism, and emplacement. On the basis of these new results and data from other ophiolites, the authors propose that ophiolites originating within large ocean basins will generally have longer crystallization-to-emplacement intervals than the more commonly recognized marginal basin-type ophiolites.
Real estate loan delinquency, property prices and alternative income opportunities

Evidence is shown, using US real estate default data from 1987–2004, that high default rates on mortgages are associated with prior period housing prices, rental income, inflation-adjusted household median income and interest rate fluctuations. This paper investigates the proposition: that the percentage of real estate defaults is a function of alternative income opportunities. Copyright © 2007 John Wiley & Sons, Ltd.
Effect of the organic ligand on the response for vanadium in flame atomic emission spectrometry

Flame emission intensities from vanadium in the forms of chelates with N-nitroso-phenylhydroxylamine and 8-quinolinol in methyl isobutyl ketone were measured. Although differences in atomic absorption characteristics for vanadium bound by different ligands have been reported, significant differences were not found in the emission intensities of these two chelates after signals for the appropriate blanks had been subtracted.
Percolation thresholds for polydisperse circular disks: A lattice-based exploration

The percolation threshold for polydisperse systems of (i) isotropically oriented, and (ii) perfectly aligned, circular disks is calculated within an analogy to a lattice model. Our results are expressed in terms of moments of the distribution function over the disk radii, and they closely resemble findings obtained from an integral equation approach. The threshold is found to be quite sensitive to polydispersity in the disk radii and, for monodisperse systems, to approach a plateau for large values of the aspect ratio (thickness to diameter ratio). A similar plateau is found for disks with perfectly nematic orientational order, for which the percolation threshold always exceeds that for identical systems of disks that are oriented isotropically.
Performance validation and energy analysis of HVAC systems using simulation

Abstract This paper describes the concept of using simulation as a tool for performance validation and energy analysis of HVAC systems. Recent advances in control system technology, including the development of open protocols such as BACnet™ have made sensor and control signal information from various components and subsystems in a building more accessible. This development has created significant potential for improving the monitoring and supervision of building systems in order to optimize operational performance. The paper describes one way of making use of this new technology by applying simulations, configured to represent optimum operation, to monitored data. The idea is to use simulation predictions as performance targets with which to compare monitored system outputs for performance validation and energy analysis. The paper presents results from applying the concepts to a large dual-duct air-handling unit installed in an office building in San Francisco.
Successful use of aztreonam in a patient who failed oral penicillin desensitization.

Abstract A 69-year-old woman with Pseudomonas aeruginosa sepsis developed wheezing during the course of an oral penicillin desensitization. Despite treatment of the bronchospasm and readministration of the same dose of phenoxymethyl penicillin, wheezing recurred requiring stopping the desensitization procedure. Aztreonam, a monobactam antibiotic with activity against aerobic gram-negative bacilli, was adminsitered along with an aminoglycoside. The patient tolerated a full course of aztreonam with no adverse reactions. This case report supports previous in vitro and in vivo studies, suggesting that aztreonam does not cross-react with penicillin-specific antibodies and that it may be well tolerated in β-lactam-allergic individuals
Design and computational flexibility

Abstract This article discusses three levels of computer use—literacy, fluency and flexibility. Literacy is about the use of particular tools to satisfy well-defined tasks while fluency is a deeper form of knowledge that allows people to adapt to the uncertainties of computing and keep up with new, technological trends. Computational flexibility suggests the further capacity toinvent software when existing applications fail to solve new problems. I will suggest a need for designers to become computationally flexible to achieve goals that often begin as ideas that are difficult, if not impossible, to articulate and hand off to expert software engineers for further development.
The importance of hyporheic sediment respiration in several mid-order Michigan rivers: comparison between methods in estimates of lotic metabolism

Metabolism was measured in four Michigan streams, comparing estimates made using a flow-through chamber designed to include the hyporheic zone to a 20 cm depth and a traditional closed chamber that enclosed to a 5 cm depth. Mean levels of gross primary productivity and community respiration were consistently greater in the flow-through chamber than the closed chamber in all streams. Ratios of productivity to respiration (P/R) were consistently greater in the closed chambers than the flow-through chambers. P/R ratios were consistently <1 in all streams when estimated with flow-through chambers, suggesting heterotrophic conditions. Maintenance of stream ecosystem structure and function therefore is dependent on subsidies either from the adjacent terrestrial system or upstream sources. Our results suggest that stream metabolism studies that rely on extrapolation of closed chambers to the whole reach will most likely underestimate gross primary productivity and community respiration.
SU-E-T-435: Automatic Monte Carlo Dose Calculations of Proton Treatment Plans.

Purpose: Providing a user friendly automated Monte Carlo dose computation system for proton treatments using passively scattered and intensity modulated proton therapy plans, developed at the proton therapy facility of the M.D. Anderson Cancer Center. Methods: In house software was developed to automatically extract patient CTimages, as well as the setup geometry and proton beam parameters from DICOM files, to create a Monte Carlo(MCNPX)model simulating the beam line arrangements of the various beams used in any given proton treatment plan. A graphical user interface provides an easy and intuitive workspace. A library of phase space files provides source proton beams with the desired modulation width and range in water. Energy deposition is scored in the voxelized CT volume, converted to dose and compared to results of analytical dose computations. Results: : Monte Carlomodels of patient specific beam line equipment, such as the brass collimator and the range compensator, as well as avoxelized model of the patient, are automatically created and implemented into the model of the simulated beam. Simulation of proton beams result in energy deposition distributions in a volume of interest defined by the user during program start. Conclusions: Current efforts focus on production ofthe phase space library and final debugging of the program flow. It is expected that a prototype version of the system will be functional in summer 2012.
Substituent effects in acid-catalyzed hydration of alkenes, measured under consistent reaction conditions

Abstract A set of convenient conditions for the title reaction is used to determine directly relative reactivities of alkenes with widely-varying steric requirements. Previous determinations did not use one set of conditions for all alkenes, but developed parameters in order to compare alkene reaction rates run in different solvents and in different concentrations; such an indirect reactivity comparison can introduce errors. Relative rates established under this common set of reaction conditions are compared to those previously calculated by using correction parameters. Comparison reveals that the approximate method overestimated effects of some groups attached to C C, such as methyl and chloro.