cssi/SciSciGPT-SciSciNet huggingface dataset:
Thermal degradation of poly(m‐diethynylene benzene)

Powdered poly(m-diethnylene benzene) can be dissolved in hot nitrobenzene, and thin clear sheets having a yellow color and a tensile strength approaching 9000 psi can be cast from this solution. When the polymer powder is heated rapidly in vacuo, it explodes gently at about 180°C. to yield carbon, but it can be annealed at 150°C. and then heated to form carbon without the explosive reaction. The major gaseous decomposition products of the explosive reaction are methane and hydrogen. The polymer film can be crystallized in tetrahydrofuran and shows excellent spherulitic growth. The crystalline film as well as aged noncrystalline film degrades when heated rapidly, but without explosive decomposition. Some indication of the mechanism of decomposition is provided by infrared studies of the film pyrolyzed at 100°C. intervals to 600°C. X-ray diffraction studies show that the polymer may exist in amorphous and crystalline forms In the amorphous form, the diffraction maximum indicates an average interchain separation of 4.28 A., substantially less than for other polymers. Chars prepared by heating the polymer give diffraction patterns similar to those for amorphous carbon blacks. A related substance, poly(p-diethynylene benzene), is an intractable crystalline powder having a hexagonal unit cell, a0 = 7.74 A., c0 = 8.97 A., containing three monomer units.
Possibly unique characteristics of learning by Primates

Abstract The experimental literature on learning by Primate and non-Primate mammals is reviewed, with the aim of identifying peculiarly Primate features of learning. The evidence indicates that quantitative comparisons of learning by Primates and other mammals are intrinsically equivocal and uninformative because of the impossibility of equating experimental conditions for members of different species. The comparative results of early learning set studies were seriously misleading because the test conditions discriminated against representatives of species in which vision is not a dominant modality. Analyses of transfer between different learning tasks strongly suggest that rhesus macaques differ qualitatively from non-Primates like cats in that they develop generalized, trans-situationally valid response strategies during training on a particular problem which can facilitate learning in other situations. Non-Primate mammals appear not to develop such strategies under the same circumstances. There is also evidence that monkeys are more able than cats to discard previously learned strategies when they are no longer maximally profitable.
A rotational model for Fe57

A model of Fe/sup 57/ is examined, in which the odd neutron is considered to move in the field of an axially symmetric rotor. The effect of band mixing is included. For a prolate deformation with sigma from 0.15 to 0.2, reasonable agreement with experiment is obtained for many of the properties of the states below 1 Mev in Fe/sup 57/. However, properties which depend on the intrinsic wave function of the 1/2- ground state are in serious disagreement with experiment. The predictions of the model are insensitive to reasonable changes in the moment of inentia of the rotor and in the parameters (other than tbe deformation) characterizing the shape of the Nilsson potential. (auth)
Use of satellite remote sensing tools for the Great Lakes

Satellite-based sensors provide synoptic measurements of surface parameters useful in detecting physical and biological conditions of the Great Lakes. Satellite surface temperature measurements using infrared spectra are compatible with buoy measurements and the time series now covers more than two decades in length. This time-series tracks seasonal warming patterns and localized upwelling events. The use of visible spectra for remote sensing of water clarity and particle composition is improving with new algorithms to separate chlorophyll-a, inorganic particles, and dissolved organic matter. The use of satellites to measure these variables holds promise for future quantification of phytoplankton production, calcite precipitation (whiting), and suspended sediment from rivers and resuspension events. Satellite imagery has also been useful for interpreting ship-collected data such as those associated with the bi-national Lake Ontario Lower Foodweb Assessment (LOLA) in 2003.
Application of the x-Plot Technique to the Study of Water Influx in the Sidi El-Itayem Reservoir, Tunisia (includes associated paper 17548 )

The x-plot technique is extended and a relationship is developed between water throughput and water cut by use of field performance data. This relationship allows the estimation of water that has invaded the drainage area of a well, a group of wells, or a field under water injection or natural water influx. Applications to a simulated waterflood, an actual waterflood in Long Beach, CA, and the water influx int he Sidi El-Itayem reservoir in Tunisia are discussed.
Unexpected thermal rearrangement of N-alkoxycarbonyl imidazole acryl azides to imidazo[1,5-c]pyrimidinone or imidazo[4,5-c]pyridinone

Rearrangement of alkoxycarbonyl imidazole acryl azides in phenyl ether at 200°C yields imidazo[1,5-c]pyrimidinone or imidazo[4,5-c]pyridinone derivatives, depending on the size of the alkoxy substituent.
LOCFES: A program for automatic determination of the order of spatial approximations in one-dimensional particle transport

Abstract The order (of the discretization error) of a spatial approximation is an important and widely used figure of merit for such approximations. For one-dimensional plane-parallel geometries, it has been shown that most such spatial approximations, as used within the discrete-ordinates directional approximation to monoenergetic particle transport, are instances of the abstract class of closed linear one-cell functional (CLOF) methods. The code LOCFES (Linear One-Cell Functional Experimental Studies) provides for highly automated determination of the order of an arbitrary CLOF method. It does so by taking advantage of the fact that such methods are defined by a relatively small number of functions that depend solely upon the direction of particle streaming, the width of the spatial cell under consideration, and the (total) cross-section within that cell. The computational kernel of LOCFES is a subroutine MONSTR (MONoenergetic Systems for Transport equation Resolution) that executes discrete source iteration, for a fixed grid and according to input specification (e.g., termination after either a specified number of iterative sweeps, or after convergence to within a specified criterion at specified monitor points.) The particular CLOF method is defined by a user-supplied subroutine that is called (only) by MONSTR, and MONSTR also returns information about the rate of convergence of the source iteration. Estimates of the order are extracted from the results provided by an automatically executed sequence of grid refinements, beginning with some input initial grid, and discrete source iterations (i.e. MONSTR calls).
Role of Protein-Tyrosine Phosphatases in Regulation of Osteoclastic Activity

Osteoclasts, the primary cell type mediating bone resorption, are multinucleated, giant cells derived from hematopoietic cells of monocyte-macrophage lineage. Osteoclast activity is, in a large part, regulated by protein-tyrosine phosphorylation. While information about functional roles of several protein-tyrosine kinases (PTK), including c-Src, in osteoclastic resorption has been accumulated, little is known about the roles of protein-tyrosine phosphatases (PTPs) in regulation of osteoclast activity. Recent evidence implicates important regulatory roles for four PTPs (SHP-1, cyt-PTP-e, PTP-PEST, and PTPoc) in osteoclasts. Cyt-PTP-e, PTP-PEST, and PTP-oc are positive regulators of osteoclast activity, while SHP-1 is a negative regulator. Of these PTPs in osteoclasts, only PTP-oc is a positive regulator of c-Src PTK through dephosphorylation of the inhibitory phosphotyrosine-527 residue. Although some information about mechanisms of action of these PTPs to regulate osteoclast activity is reviewed in this article, much additional work is required to provide more comprehensive details about their functions in osteoclasts.
Safety and tolerability of angiotensin-converting enzyme inhibitor versus the combination of angiotensin-converting enzyme inhibitor and angiotensin receptor blocker in patients with left ventricular dysfunction: a systematic review and meta-analysis of randomized controlled trials.

Abstract Background The addition of an angiotensin receptor blocker (ARB) to an angiotensin-converting enzyme inhibitor (ACEI) in patients with heart failure remains controversial. A recent meta-analysis showed that the combination therapy reduces hospitalization without improved survival. Whether excess risk is associated with this strategy has not been fully explored. We sought to quantify the risk of adverse events of combination therapy (ACEI+ARB) versus ACEI alone. Methods MEDLINE, EMBASE, BIOSIS, and Cochrane databases were searched. Eligible studies were randomized, placebo-controlled trials of ACEI versus the combination of ACEI+ARB in patients with heart failure or left ventricular dysfunction. Included studies were reviewed to determine the frequency of adverse effects leading to discontinuation of therapy. Results Nine trials that enrolled 18,160 patients met the inclusion criteria. A total of 9199 patients received combination therapy, and 8961 patients received an ACEI only. Patients receiving combination therapy had an increased risk of developing any adverse effect by 2.3% (relative risk [RR] = 1.27, 95% confidence interval [CI] = 1.15–1.40, P 2 = 15.9%, number needed to harm [NNH] = 42), hypotension by 1.1% (RR = 1.91, 95% CI=1.37–2.66, P = .0002, I 2 = 26.6%, NNH=89), worsening renal function by 1% (RR = 2.12, 95% CI=1.30–3.46, P = .003, I 2 = 67.3%, NNH=100), and hyperkalemia by 0.6% (RR = 4.17, 95% CI=2.31–7.53, P 2 = 0%, NNH=149). There was no difference in angioedema (RR = 0.88, 95% CI=0.43–1.80, P = .72, I 2 = 0%) or cough (RR = 0.84, 95% CI=0.65–1.09, P = .19, I 2 = 0%). Conclusion The current cumulative evidence suggests that patients with left ventricular dysfunction have an increased risk of adverse events leading to discontinuation on ACEI+ARB combination therapy compared with ACEI alone. This excess risk, coupled with a lack of consistent mortality benefit, suggests that ARBs should not routinely be added to ACEI therapy for left ventricular dysfunction. If chosen, the combination strategy may warrant closer patient monitoring to detect adverse effects.
Looking deeper into vertebrate development.

Magnetic resonance imaging (MRI) is a non-invasive imaging method that provides three-dimensional (3-D) images of the internal structure of opaque objects, such as humans and mice. In optimal situations, spatial resolution can approach the micron level. Arbitrarily oriented single-slice images can be obtained in seconds, with full 3-D volume images taking tens of minutes to collect. The exquisite sensitivity of MRI to the local physical and chemical environment provides a wide range of mechanisms giving rise to intrinsic contrast in the MR experiment, thus providing images with dramatic differences between different tissue types (e.g. white vs grey matter, myelinated vs unmyelinated fibres, and brain parenchyma vs ventricles). The recent advent of physiologically sensitive MRI contrast agents opens up a wealth of new avenues of study, even including the in vivo imaging of gene expression.
The Interaction of Estuarine and Shelf Waters: A Model and Applications

Abstract An analytical model is developed to describe the steady flow in an estuary-shelf interaction region where the system is treated as a two layer density stratified flow. The motion is expanded in terms of the relative thickness of the vertical Ekman layer. The zero-order flow is geostrophic in each layer. Balancing of order-one quantities reduces the system to two vorticity equations relating the pressure field with the displacement of the interface and the bottom topography. An explicit solution is obtained for the case of linear offshore sloping bottom. The flow behavior of the estuarine plume depends on the vertical structure of the flow at the river mouth, the bottom slope and the ambient coastal flow. Under certain conditions. a front exists as an offshore boundary of the plume. These results are compared with observations for the Changjiang River Estuary (in China), and both the Chesapeake Bay and Savannah River estuaries in the United States.
Early behavior problems: Pathways to mental disorders in adolescence

From teachers' rating in kindergarten through third grade, mutually exclusive groups of internalized, externalized, and mixed behavior problems were examined as pathways to three groups of psychiatric diagnosis in later adolescence: depression/anxiety, conduct/oppositional defiant, and other disorders. In looking both forward and backwards, the relation between behavior problems in the early school years, regardless of type, and psychopathology in adolescence, regardless of diagnosis, was very strong. The relations between type of early problems and specific outcomes were weak. The findings provided support for both the constructs of multifinality and equifinality; however the nature of the pathways differed somewhat by disorder. There was a substantial amount of multifinality (dispersion of outcomes) for the early internalizing pathway. There was less multifinality for the externalizing pathway, in that there was greater correspondence between early externalizing and later antisocial outcomes than for the internalizing pathway and depressed/anxious outcomes.
False Alarm Rate and False Alarm Number for Discrete and Continuous Time Sampling

A comparison of the false alarm rates and false alarm numbers for discrete and continuous time sampling is given for different noise spectrums (rectangular, Hamming, Gaussian, and cosine noise voltage spectrums) and for different sampling rates for the case of discrete time sampling. Also given is the increase in the false alarm rate when going from discrete to continuous time sampling when the detection threshold is held fixed. The amount that the threshold has to be increased for continuous sampling to achieve the same false alarm rate obtained with discrete time sampling is also given.
Combination Antiretroviral Therapy in African Nursing Mothers and Drug Exposure in Their Infants: New Pharmacokinetic and Virologic Findings

Africa’s HIV/AIDS epidemic has reached crisis proportions and calls for a rapid expansion of both prevention and treatment services particularly among young women and children. Mother-to-child transmission (MTCT) is the most important source of HIV-1 infection in children and prolonged breast-feeding is associated with a near doubling of the risk of MTCT. In resource-limited settings the majority of HIV-1–infected mothers choose to breast-feed because of cultural norms the high cost of formula the lack of a safe water supply and the stigma associated with not breast-feeding. Reducing HIV-1 transmission during lactation remains a pressing global health dilemma confronting HIV-1–infected women health-care providers and policy makers. Clinical trials are currently under way to assess whether the use of highly active antiretroviral therapy (HAART) during late pregnancy and during the first 6 months of lactation followed by early weaning can substantially reduce the risk of HIV-1 transmission among breast-feeding women. In addition it is anticipated that eligible HIV-1–infected nursing mothers in sub- Saharan Africa will increasingly be able to receive HAART for the maintenance of their own health. (excerpt)
Mercaptans as promoters and modifiers in emulsion copolymerization of butadiene and styrene using potassium persulfate as catalyst. IV. Definition and calculation of modifier efficiency

The calculation of the “theoretical” minimum modifier requirement, TMMR, for butadiene-styrene (75:25) copolymers of given intrinsic viscosities at various conversions is described. The TMMR of 75% conversion polymer of intrinsic viscosity 2.0 is R0 = 0.28, which is only about 60% of the value of R0 for commercial primary dodecyl mercaptan (C.M.) in large-size reactors. The efficiency, E, of a modifier for 75:25 butadiene-styrene copolymerization using soap as emulsifier and persulfate as catalyst has been defined by and calculated from the equation: where Mv is the intrinsic viscosity molecular weight of the polymer at conversion, P, with an amount of mercaptan, R0, charged with the monomers. For all modifiers the efficiency is low at low conversions and gradually increases to a maximum with increasing conversion. For different modifiers this maximum may be as at low as 10% conversion or at higher than 80% conversion. After the maximum the efficiency decreases with further increase of conversion. The most efficient modifier for the production of polymers of intrinsic viscosity, [η], at conversion, P, will meet the following conditions, R = 1 at conversion, P, and dP/dR is constant. Inefficient modifiers may be made more efficient by changing the conditions or procedure of polymerization in such a way that the modifier more nearly complies with the above conditions.
Kinetics of the barotropic ripple (P beta')/lamellar liquid crystal (L alpha) phase transition in fully hydrated dimyristoylphosphatidylcholine (DMPC) monitored by time-resolved x-ray diffraction.

We present here the first study of the use of a pressure-jump to induce the ripple (P beta')/lamellar liquid crystal (L alpha) phase transition in fully hydrated 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC). The transition was monitored by using time-resolved x-ray diffraction (TRXRD). Applying a pressure-jump from atmospheric to 11.3 MPa (1640 psig, 111.6 atm) in 2.5 s induces the L alpha to P beta' phase transition which takes place in two stages. The lamellar repeat spacing initially increases from a value of 66.0 +/- 0.1 A (n = 4) to a maximum value of 70.3 +/- 0.8 A (n = 4) after 10 s and after a further 100–150 s decreases slightly to 68.5 +/- 0.3 A (n = 4). The reverse transition takes place following a pressure jump in 5.5 s from 11.3 MPa to atmospheric pressure. Again, the transition occurs in two stages with the repeat spacing steadily decreasing from an initial value of 68.5 +/- 0.3 A (n = 3) to a minimum value of 66.6 +/- 0.3 A (n = 3) after 50 s and then increasing by approximately 0.5 A over a period of 100 s. The transition temperature increases linearly with pressure up to 14.1 MPa in accordance with the Clapeyron relation, giving a dT/dP value of 0.285 degrees C/MPa (28.5 degrees C/kbar) and an associated volume change of 40 microliters/g. A dynamic compressibility of 0.13 +/- 0.01 A/MPa has been determined for the L alpha phase. This value is compared with the equilibrium compressibilities of bilayer and nonbilayer phases reported in the literature. The results suggest testable mechanisms for the pressure-induced transition involving changes in periodicity, phase hydration, chain order, and orientation. A more complete understanding of the transition mechanism will require improvement in detector spatial resolution and sensitivity, and data on the pressure sensitivity of phase hydration.
Genetic and Functional Modularity of Hox Activities in the Specification of Limb-Innervating Motor Neurons

A critical step in the assembly of the neural circuits that control tetrapod locomotion is the specification of the lateral motor column (LMC), a diverse motor neuron population targeting limb musculature. Hox6 paralog group genes have been implicated as key determinants of LMC fate at forelimb levels of the spinal cord, through their ability to promote expression of the LMC-restricted genes Foxp1 and Raldh2 and to suppress thoracic fates through exclusion of Hoxc9. The specific roles and mechanisms of Hox6 gene function in LMC neurons, however, are not known. We show that Hox6 genes are critical for diverse facets of LMC identity and define motifs required for their in vivo specificities. Although Hox6 genes are necessary for generating the appropriate number of LMC neurons, they are not absolutely required for the induction of forelimb LMC molecular determinants. In the absence of Hox6 activity, LMC identity appears to be preserved through a diverse array of Hox5–Hox8 paralogs, which are sufficient to reprogram thoracic motor neurons to an LMC fate. In contrast to the apparently permissive Hox inputs to early LMC gene programs, individual Hox genes, such as Hoxc6, have specific roles in promoting motor neuron pool diversity within the LMC. Dissection of motifs required for Hox in vivo specificities reveals that either cross-repressive interactions or cooperativity with Pbx cofactors are sufficient to induce LMC identity, with the N-terminus capable of promoting columnar, but not pool, identity when transferred to a heterologous homeodomain. These results indicate that Hox proteins orchestrate diverse aspects of cell fate specification through both the convergent regulation of gene programs regulated by many paralogs and also more restricted actions encoded through specificity determinants in the N-terminus.
Penman's sink-strength model as an improved approach to estimating plant canopy transpiration

Abstract The Penman energy balance equation has become a common approach to estimating the evaporation of plant canopies. Unfortunately, implementation of the energy balance equation requires various assumptions and empiricisms, including “crop coefficients”, so that in practice the Penman equation is used as a framework in which to apply empirical approximations. These limitations are reviewed in this paper. An alternative to the energy balance approach suggested by Penman was a “sink strength” model in which the gradient in vapor pressure was considered the prime driver of plant water loss. In this paper, the sink strength model is developed for determining plant canopy transpiration based on explicitly defined properties of the plants. The key variables are the carbon assimilation pathway of photosynthesis and the biochemical composition of the plant material being synthesized. These two parameters define the transpiration efficiency coefficient and radiation use efficiency that are required in the calculation of transpiration. Also, it is necessary to define a weighted vapor pressure gradient for transpiration when making estimates of the amount of transpiration on a daily basis. The derived expression of the sink strength model was used to compare predicted transpiration with measured values of four turf grass species measured over three years. A close linear correlation was observed for all grasses ( P
Literature Review of Research in Family Systems Treatment of Sexual Addiction

Many clinicians describe using a family systems approach to treating sexual addiction, and this model seems to be widely considered a treatment of choice. However, little empirical validation exists to support this theory. This article outlines the theory of systemic treatment and reviews some initial studies that analyze this condition from a systems perspective. The author discusses the need for further research in this area.
Preoperative CA 19-9 and the Yield of Staging Laparoscopy in Patients with Radiographically Resectable Pancreatic Adenocarcinoma

Staging laparoscopy for patients with radiographically resectable pancreatic adenocarcinoma has been reported to yield an 8–15% finding of unresectable disease. Factors associated with the likelihood of subradiographic unresectable disease have not been clearly defined. A prospectively maintained pancreatic database was reviewed and patients were identified who underwent staging laparoscopy for radiographically resectable pancreatic adenocarcinoma between January 2000 and December 2006. Preoperative carbohydrate antigen 19-9 (CA 19-9) values were assessed for their association with the presence of subradiographic unresectable disease. Four hundred ninety-one patients underwent staging laparoscopy. Resection was performed in 80% (n = 395). Of the 96 patients with unresectable disease, 75 (78%) had metastases either in the liver (n = 60) or peritoneum (n = 15). Preoperative CA 19-9 values were available for 262 of the 491 patients. Fifty-one of these patients had unresectable disease, of which 78% were due to distant disease. The median preoperative CA 19-9 value for patients who underwent resection was 131 U/ml versus 379 U/ml for those patients with unresectable disease (P = 0.003). A receiver operating characteristics (ROC) curve was developed for preoperative CA 19-9 value and tumor resectability. The statistically optimal cutoff value was determined to be 130 U/ml. Unresectable disease was identified in 38 of the 144 patients (26.4%) with a preoperative CA 19-9 ≥ 130 U/ml, and in 13 of the 118 patients (11%) with a CA 19-9 < 130 U/ml (P = 0.003). CA 19-9 values greater than 130 U/ml remained a predictor of tumor unresectability on multivariate regression analysis [hazard ratio (HR) 2.70, 95% confidence interval (CI) 1.34–5.44; P = 0.005]. In this study, preoperative CA 19-9 values were strongly associated with the identification of subradiographic unresectable disease. Preoperative CA 19-9 values may allow surgeons to better select patients for staging laparoscopy.
Mass spectrometric dereplication of nitrogen-containing constituents of black cohosh (Cimicifuga racemosa L.)

Black cohosh preparations are popular dietary supplements among women seeking alternative treatments for menopausal complaints. For decades, triterpene glycosides and phenolic acids have dominated the phytochemical and biomedical research on this plant. In this study, we provide evidence that black cohosh contains an unexpected and highly diverse group of secondary nitrogenous metabolites previously unknown to exist in this plant. Using a dereplication approach that combines accurate mass measurements, database searches and general knowledge of biosynthetic pathways of natural products, we identified or tentatively identified 73 nitrogen-containing metabolites, many of which are new natural products. The identified compounds belong to several structural groups including alkaloids, amides or esters of hydroxycinnamic acids and betains. Among the alkaloids, several classes such as guanidino alkaloids, isoquinolines and β-carbolines were identified. Fragmentation patterns for major compound classes are discussed, which provides a framework for the discovery of these compounds from other sources. Identification of alkaloids as a well-known group of bioactive natural products represents an important advance in better understanding of the pharmacological profile of black cohosh.
Decision Making: The Virtue of Patience in Primates

Marmoset monkeys devalue rewards requiring travel to acquire, but tamarin monkeys do not, despite the greater patience of marmosets when rewards are delayed in time. Such preference reversals, not predicted by standard economic theory, may reflect behavioral mechanisms adaptively specialized for different spatial and temporal patterns of foraging.
The developmental course of defense mechanisms in later life.

Many have proposed that in later life there is a return to the use of primitive psychological defense mechanisms, such as denial and projection. The theoretical literature is clouded by a common fa...
Multi-objective Decisions on Capacity Planning and Production−Inventory Control under Uncertainty

In the presence of a changing and stochastic environment, firms must appropriately choose the timing and sizes of capacity acquisition as well as the production decisions to replenish inventory, such that various conflicting goals are satisfied. This paper considers multicriteria decision making on joint capacity planning and inventory control under uncertainty. We formulate this class of problems into a multi-objective Markov decision process, which simultaneously searches for both capacity and inventory policies that optimize multiple objectives. In a previous work, we developed a multi-objective dynamic programming algorithm to solve small problems by propagating Pareto optimal solutions recursively backward in time. The numerical intractability of the rigorous algorithm for large problems necessitates approximation approaches. However, and importantly, on the basis of the optimality equations constructed in the dynamic programming framework, we are able to obtain analytical insights into the structure...
The Importance of Being First: An Analysis of Tachistoscopic Presentations of Words

Abstract The importance of the first letter of a word as a cue for the rest of the word was explored in a tachistoscopic presentation of four letter English words to the two hemispheres. The positioning of words presented bilaterally and the frequency of the words were manipulated so that the role of the first letter could be examined. The results indicate that the first letter does not play the critical role in word recognition that has been ascribed to it. In the standard bilateral presentation, subjects' recall patterns indicated that first letters were recalled equally well whether the word was presented in the right or left visual field. However, subjects did not recall as many words correctly when they went to the left visual field. The results were interpreted as supporting an informationprocessing view of hemispheric specialization. Such a view proposes several levels of functioning in which the two hemispheres overlap, cooperate, or specialize, depending on the task to be accomplished.
Amplitude scaling in a bimanual circle-drawing task: pattern switching and end-effector variability.

The authors manipulated movement amplitude in a bimanual circle-tracing task performed by 11 participants. With pacing frequency fixed, the systematic increase and decrease of circle diameter within a trial induced phase transitions from the asymmetric (33% of trials) to the symmetric bimanual circletracing pattern; the transitions resulted from a loss of stability in the asymmetric pattern. Tracing frequency varied inversely with circle diameter so that end-effector variability was minimized in a set of self-paced trials in which the circle diameter in a trial was fixed. In the amplitude-scaling trials, end-effector variability varied directly with circle diameter, a consistent speed-accuracy tradeoff. The results support the conclusion that movement amplitude is a nonspecific control parameter. The findings are discussed with reference to several factors, e.g., tactile feedback, the recruitment and suppression of biomechanical degrees of freedom, and the role those factors may play in stabilizing bimanu...
Transcervical Resection of the Endometrium Using Intracervical Block Only A Review of 278 Procedures

The objective of this study was to assess the efficacy and safety aspects of performing transcervical endometrial resection (T.C.R.E.) on a selected group of 278 patients with menstrual disorders under local analgesia (intracervical block) only. Patient acceptance of the procedure was high, with only 3 cases not completed due to insufficient analgesia (1.07%), although a further 9 (3.2%) were completed with the help of intravenous sedation. Patient satisfaction at 4 months was 90%. There were 4 perforations (1.4%), but no laparotomy was required. Five cases (1.7%) of haemorrhage required a Foley catheter, with 1 needing a transfusion. There was no case of clinically evident glycine overload. Twelve patients required an overnight stay. Patient acceptance of T.C.R.E. under local analgesia, and the incidence of major complications, compared favourably with other published series, including a series of 330 cases performed concurrently by the same operators under general anaesthesia.
Electron depletion in the wake of ionospheric spacecraft—A comparison between results from Langmuir probes and antennas

Abstract In situ observations of the electron depletion in the wakes of satellites and rockets in the ionosphere using Langmuir type probes and antennas are analyzed and compared. The quantitative degree of agreement between the results is demonstrated and discussed. One consequence is an improved interpretation of results previously presented for the OGO II Satellite wake.
Investigation of the Structure and Dynamics of Surfactant Molecules in Mesophase Silicates Using Solid-State 13C NMR

The structure and dynamics of surfactant molecule reorganization in mesophase silicates have been investigated using variable-temperature {sup 13}C solid-state nuclear magnetic resonance (NMR) spectroscopy. Functional groups and side groups of the surfactant CTAC (cetyltrimethylammonium chloride) were identified from high-resolution {sup 13}C MAS (magic angle spinning) NMR spectra obtained using high-power {sup 1}H decoupling. We also obtained information on surfactant organization and relaxation in mesophase silicates using a combination of NMR line-shape and relaxation-time analyses with variable-temperature NMR. The behavior of the surfactant in the ordered mesophase silicate was compared with that of the surfactant solution (CTAC-water) and that of the surfactant in the disordered silicate, which was precipitated in solution during an early stage of the reaction. The splitting of the resonance associated with the N-methyl groups suggests that the methyl groups next to the head group lose their stereochemical symmetry due to the intermolecular interaction in the ordered mesophase silicates. For both ordered and disordered silicates, the methylene group adjacent to the head group exhibits a marked lack of motion relative to other segments of the surfactant. Variable-temperature NMR studies show motional narrowing as temperature increases. 17 refs., 9 figs., 2 tabs.
Glucagon-like peptide-1 stimulates insulin secretion by a Ca2+-independent mechanism in Zucker diabetic fatty rat islets of Langerhans.

Abstract This study investigates the mechanisms responsible for glucagon-like peptide-1 (GLP-1)-induced insulin secretion in Zucker diabetic fatty (ZDF) rats and their lean control (ZLC) littermates. Glucose, and 100 nmol/L GLP-1 (7-37 hydroxide) in the presence of stimulatory glucose concentrations, induced insulin secretion in islets from ZLC animals. In contrast, ZDF islets hypersecreted insulin at low glucose (5 mmol/L) and were poorly responsive to 15 mmol/L glucose stimulation, but increased insulin secretion following exposure to GLP-1. The insulin secretory response to 100 nmol/L GLP-1 was reduced by 88% in ZLC islets exposed to exendin 9-39. The intracellular Ca2+ concentration ([Ca2+]i) increased in fura-2-loaded ZLC islets following stimulation with 12 mmol/L glucose alone or GLP-1 in the presence of 12 mmol/L glucose. The increases in [Ca2+]i and insulin secretion in ZLC islets induced by GLP-1 were attenuated by 1 μmol/L nitrendipine. In contrast, neither glucose nor GLP-1 substantially increased [Ca2+]i in ZDF islets. Furthermore, insulin secretory responses to GLP-1 were not significantly inhibited in ZDF islets by nitrendipine. However, the insulin secretory response to GLP-1 in both ZLC and ZDF islets was ablated by cholera toxin. Our findings indicate that in ZLC islets, GLP-1 induces insulin secretion by a mechanism that depends on Ca2+ influx through voltage-dependent Ca2+ channels, whereas in ZDF islets, the action of GLP-1 is mediated by Ca2+-independent signaling pathways.
Arterial influx, efflux and tissue content of albumin in rabbits in vivo.

The uptake, in vivo, of l25I-labelled rabbit serum albumin by the thoracic intima-media of rabbits was determined at different times after single injection of the tracer. Plasma decay of radioactivity was monitored until sacrifice. Kinetic analysis of the plasma decay by a three compartment model gave the values of the fractional rates of catabolism and of transfers between intra- and two extravascular compartments. The uptake data were analysed by a similar compartmental model involving transfers between plasma and arterial tissue. kin, the fractional rate of influx into the tissue and kout, the fractional rate of efflux from the tissue were calculated by a procedure proposed earlier. The values of kin and kout (0.055 μl·cm−2·h−1 and 0.2 h−1), converted to proper units, are closer to the fractional rates for the slowly exchanging pool, probably representing tissues with non-fenestrated endothelium. On the basis of the model and a normal plasma level of albumin, it can be calculated that the steady state albumin content of intima-media should be about 11 μg·cm−2. Direct determination of arterial albumin content by electroimmunoassay gave a value consistent with this.
Survivable scheduled service provisioning in WDM optical networks with iterative routing

Survivable service provisioning design has emerged as one of the most important issues in communication networks in recent years. In this work, we study survivable service provisioning with shared protection under a scheduled traffic model in wavelength convertible WDM optical mesh networks. In this model, a set of demands is given, and the setup time and teardown time of a demand are known in advance. Based on different protection schemes used, this problem has been formulated as integer linear programs with different optimization objectives and constraints in our previous work. The problem is NP-hard. We therefore study time efficient heuristic solutions to the problem. Our approach is based on an iterative survivable routing (ISR) scheme that utilizes a capacity provision matrix and processes demands sequentially using different demand scheduling policies. The objective is to minimize the total network resources (e.g., number of wavelength-links) used by working paths and protection paths of a given set of demands while 100% restorability is guaranteed against any single failure. The proposed algorithm is evaluated against solutions obtained by integer linear programming. Our simulation results indicate that the proposed ISR algorithm is extremely time efficient while achieving excellent performance in terms of total network resources used. The impact of demand scheduling policies on the ISR algorithm is also studied.
Adult blood pressure reduction in spontaneously hypertensive rats reared by normotensive Sprague—Dawley mothers

Spontaneously hypertensive (SHR), Wistar—Kyoto (WKY) normotensive, and Sprague—Dawley (SD) normotensive rats were either reared by their natural mothers (controls) or fostered to a mother of one of the other strains. The effects of rearing environment were assessed by measures of body weight at weaning and adult resting mean arterial blood pressure (MAP) and heart rate (HR). At weaning, SHR control rats weighed less than WKY controls which in turn weighed less than SD controls. SHR and WKY rats reared by SD mothers weighed significantly more than their respective controls, whereas SD rats reared by either SHR or WKY mothers weighed less than SD control rats. Manipulation of the maternal environment was attended by a change in adult resting MAP in only one group. SHR rats reared by SD mothers had MAPs which were significantly lower than SHRs reared by their natural mothers. No within-strain adult HR differences were observed between control and cross-fostered groups. These data indicate that the effects of cross-fostering on adult resting MAP previously reported for SHR and WKY animals are generalizable to another normotensive strain. That is, genetically hypertensive (SHR) animals exposed to a normotensive (WKY or SD) maternal environment display a reduction in adult resting MAP, whereas hypertension or an increase in adult MAP is not induced in normotensive rats (WKY or SD) as a consequence of exposure to a hypertensive maternal environment.
Depression and risk of developing dementia

Depression is highly common throughout the life course and dementia is common in late life. Depression has been linked with dementia, and growing evidence implies that the timing of depression may be important in defining the nature of this association. In particular, earlier-life depression (or depressive symptoms) has consistently been associated with a more than twofold increase in dementia risk. By contrast, studies of late-life depression and dementia risk have been conflicting; most support an association, yet the nature of this association (for example, if depression is a prodrome or consequence of, or risk factor for dementia) remains unclear. The likely biological mechanisms linking depression to dementia include vascular disease, alterations in glucocorticoid steroid levels and hippocampal atrophy, increased deposition of amyloid-β plaques, inflammatory changes, and deficits of nerve growth factors. Treatment strategies for depression could interfere with these pathways and alter the risk of dementia. Given the projected increase in dementia incidence in the coming decades, understanding whether treatment for depression alone, or combined with other regimens, improves cognition is of critical importance. In this Review, we summarize and analyze current evidence linking late-life and earlier-life depression and dementia, and discuss the primary underlying mechanisms and implications for treatment.
Potential usefulness of FDG PET/CT in patients with sepsis of unknown origin.

Purpose: The role of FDG PET in the evaluation of patients with sepsis of unknown origin remains unclear. We sought to assess the value of FDG PET/CT in patients with sepsis of unknown cause and to define its priority in this group of subjects. Methods: A total of 53 patients with sepsis of unknown origin underwent FDG PET/CT within two weeks of diagnosis. All of the patients were followed up for at least 3 months after discharge to determine the clinical outcomes. The impact of FDG PET/CT was assessed according to the number of cases who had their treatment modified on the basis of the imaging results. Logistic regression analysis was used to identify the independent predictors of positive FDG PET/CT findings. Results: Of the 53 study patients, 35 (66%) had positive FDG PET/CT findings, and 13 (25%) had their treatment modified on the basis of the imaging results. Logistic regression analysis identified normal serum aspartate aminotransferase (odds ratio [OR] =6.134; 95% confidence interval [CI] =1.443–26.076, P=0.014) and increased serum alkaline phosphatase levels (OR=5.813; 95% CI=1.386–24.376, P=0.016) at diagnosis as independent predictors of positive FDG PET/CT findings. A scoring system using these two covariates was developed, which defined three distinct priority groups for FDG PET/CT imaging. Conclusion: Our findings suggest that FDG PET/CT may be clinically useful for the detection of occult foci of infection in patients with sepsis of unknown origin.
A numerical study of long range internal stresses associated with subgrain boundaries

Abstract A simple two-dimensional numerical model is developed to examine the stress fields associated with subgrain boundaries. It is shown that when low angle tilt boundaries are biased by an applied stress, long range internal stresses are developed. These stress fields have a periodicity of the order of the subgrain size, and are consistent with measurements of creep anelasticity and studies of in situ dislocation motion. The behavior of single subgrains and finite arrays of subgrains is examined.
Enantioselective Intramolecular Friedel−Crafts-Type α-Arylation of Aldehydes

Enantioselective organo-SOMO catalysis has, in the last two years, been the subject of considerable development and exploration. A number of new and unique transformations have been reported, such as α-allylation, α-oxyamination, α-enolation, and α-vinylation of aldehydes. Herein, we report a modification of this activation mode that involves the intramolecular Friedel−Crafts-type α-arylation of aldehydes carrying electron-donating groups on their aromatic nucleus and its application to the total synthesis of demethyl calamenene, a potent cytotoxic agent against human adenocarcinoma A 549.
Strategies for maximizing seller's profit under unknown buyer's valuations

Suppose there is a seller that has an unlimited number of units of a single product for sale. The seller at each moment of time posts a price for his/her product. Based on the posted price, at each moment of time, a buyer decides whether or not to buy a unit of that product from the seller. The only information about the buyer available to the seller is the seller's sales history. Further, we assume that the maximal unit price the buyer is willing to pay does not change over time. The question then is how should the seller price his/her product to maximize profits? To address this question, we use the notion of loss functions. Intuitively, a loss function is a measure, at each moment of time, of the lost opportunity to make a profit. In particular, we provide a polynomial-time algorithm that finds a pricing algorithm (strategy) for the seller that minimizes the average (total) losses over time. Further, we provide efficient algorithms for finding pricing strategies for maximizing the cumulative seller's profits when the sales period is limited, there is a limited supply of the product for sale, and the buyer's valuation is a non-increasing function of time, where those functions are known to the seller. We also present preliminary results on pricing strategies that minimize the maximum loss, and we show show that there is no strategy minimizing both the total loss and the maximum loss at the same time.
Transport of Pseudomonas fluorescens strain P17 through quartz sand columns as a function of water content

Porous media column experiments were used to investigate Pseudomonas fluorescens strain P17 transport as a function of water content and the influences of the solid-liquid and gas-liquid interfaces. Retention of radiolabeled P17 in washed quartz sand was evaluated at 100, 84, and 46% water saturation. At the completion of each experiment, the porous medium was extruded and sampled directly for cell retention on the basis of a radiolabel mass balance. Maximum cell retention occurred in the top centimeter of porous media at all three water contents and decreased . with depth in the column. The total fraction of cells retained R was inversely proportional to t . water content, with nearly twice the cell retention at 46% saturation R s 0.95 compared to t .
An examination of asynchronous communication experiences and perspectives of students in an online course: a case study

The purpose of this qualitative case study was to explore the asynchronous communication perspectives and experiences of undergraduate students in an online course. Interviews with 22 preservice teachers, student-to-instructor email transcripts, asynchronous discussion transcripts, and two independent reviewers' reviews of the asynchronous discussions were used to collect and analyze the data. The results of this study have implications for the effective design of asynchronous communication, and interaction between student and instructor, between student and student, and between student and content. The results inform researchers and practitioners of the factors, strategies and barriers that need to be taken into account, and suggestions for how to overcome barriers when utilizing asynchronous communication tools for learning. A comprehensive understanding of computer-mediated communication tools and student preferences and experiences can contribute to a knowledge base for effective planning and implementation of successful learning.