cssi/SciSciGPT-SciSciNet huggingface dataset:
Target manifold formation using a quadratic SDF

Synthetic Discriminant Function (SDF) formulation of correlation filters provides constraints for forming target subspaces for a target set. In this paper we extend the SDF formulation to include quadratic constraints and use this solution to form nonlinear manifolds in the target space. The theory for forming these manifolds will be developed and demonstrated with data.
Temperature-Dependent Halogen-Exchange Activity Studies of Zeolite-Derived Aluminum Trifluoride

A high-surface-area (190 m2/g) amorphous aluminum trifluoride material (“plasma-AlF3”) was synthesized by plasma decomposition of zeolite, and its structural and reactivity properties were investigated. High-resolution transmission electron microscopy of plasma-AlF3 indicates morphological features on the nanometer-scale, whereas temperature-programmed X-ray diffraction is used to determine the phase-transition temperatures of plasma-AlF3 to β- and α-AlF3. Halogen-exchange reactivity is studied by temperature-programmed reaction (TPR) techniques using the dismutation of CCl2F2 as a model reaction. Plasma-AlF3 is found to possess an unexpected low-temperature (>315 °C) activity not observed with the well-known halogen-exchange catalyst β-AlF3. Supporting TPR studies on aluminum trifluoride hydrates are performed to correlate this new activity with an amorphous AlF3 structure, and a simple Lewis acid model is presented to explain the reactivity data.
Exchange rate regime reforms with black market leakages

Abstract Many countries have multiple exchange rate regimes, with black or secondary currency markets operating alongside an exchange rate pegged or determined in interbank or auction markets. Leakages occur across these markets, necessitating careful analysis of the dynamic effects of numerous policy instruments. Using a model with multiple exchange rates and leakages, we trace the dynamic effects on official and parallel foreign exchange markets of exchange rate unification, changes in foreign exchange surrender requirements, taxes on trade and capital account transactions, and official exchange rate devaluation. Simulations based on Russia's recent experience demonstrate the qualitative importance of the results.
Regional blood flow changes in response to near maximal exercise in ponies: a review.

Summary In recent years, increasing attention has been focused on the physiological responses of the horse to maximal exercise. Cardiovascular response in near maximally exercised galloping ponies (heart rate 225 ± 7 beats/min; whole body oxygen consumption 122 ± 12 ml/min/kg) comprised a marked increase in blood flow to the cerebellum, myocardium, diaphragm and the working muscles, while renal blood flow decreased precipitously. Cerebral and brainstem perfusion did not vary from resting values. Transmural homogeneity of myocardial blood flow persisted during near maximal exercise. It was reported that tachycardia of exercise contributed about one-third of the total increment in left ventricular coronary blood flow. Considerable unutilised coronary vasodilator capacity was also demonstrated in near maximally exercised ponies and it was suggested that maximally exercising ponies were not limited from further exertion because of the coronary circulation.
Myocardial perfusion, function and exercise tolerance after the arterial switch operation

Abstract Objectives . This study was conducted to determine the prevalence of myocardial perfusion abnormalities at rest and exercise and to assess exercise capacity in children after the arterial switch operation. Background . There have been sporadic reports of myocardial ischemia or sudden death in children after the arterial switch operation for transposition of the great arteries, possibly related to inadequate coronary perfusion due to kinking or stenosis of the translocated coronary arteries. Methods . Myocardial perfusion at rest and peak exercise was assessed using the scintigraphic agent technetium-99m methoxyisobutyl isonitrile (sestamibi). Exercise capacity was determined with a modified Brace protocol. Ambulatory etectrocardiographic (ECG) Holter monitoring was performed. Ventricular function, contractility and wall motion were assessed echocardiographically. Results . Twenty-three children (aged 4.2 to 7.9 years) underwent evaluation. Abnormalities were found on the rest perfusion scans in 22 children (95.6%). The left ventricular myocardium was divided into 13 segments for analysis. Of 299 rest segments, 225 (75.3%) were normal, 11 (3.7%) showed mild defects, 45 (15%) moderate defects and 18 (6%) severe defects at rest. At peak exercise, 237 segments (79.3%) were normal, 24 (8%) showed mild defects, 33 (11%) moderate defects and 5 (1.7%) severe defects. Compared with rest studies, myocardial perfusion grade at exercise was unchanged in 246 segments (82.3%), improved in 42 (14%) and worsened in 11 (3.7%). All patients had normal exercise tolerance without symptoms or ischemic ECG changes. No ventricular tachycardia was seen on Holter monitoring. All patients had a shortening fraction ≥27%. Left ventricular contractility was normal in 12 children in whom it was assessed. Regional wall motion was normal in 17 children with adequate echocardiographic images for this analysis. Conclusions . Myocardial perfusion scan abnormalities assessed by technetium-99m sestamibi are common after an arterial switch operation. These abnormalities are of uncertain clinical significance and generally lessen with exercise. The normal exercise tolerance without symptoms or ECG changes suggests that myocardial perfusion is adequate during the physiologic stress of exercise in children up to 8 years after an arterial switch operation.
Increased c-fos expression in spinal lumbosacral projection neurons and preganglionic neurons after irritation of the lower urinary tract in the rat

Abstract Chemical irritation of the lower urinary tract (LUT) induces c- fos expression in neurons in the lumbosacral (L 6 and S 1 ) spinal cord. This study used axonal tracing with fluorescent dyes to identify the types of spinal neurons expressing Fos immunoreactivity (IR) after LUT irritation in the rat. Fos-IR was detected in lateral and medial superficial dorsal horn, the sacral parasympathetic nucleus (SPN) and lamina X around the central canal. Fos-IR was detected in spinal neurons projecting to supraspinal sites (brainstem and hypothalamus), in preganglionic neurons (PGN) and in unlabeled segmental interneurons. A substantial percentage (20%) of dye labeled PGN exhibited Fos-IR after LUT irritation; and a larger percentage (36%) exhibited Fos-IR after electrical stimulation of the pelvic nerve which contains afferent pathways from all of the pelvic organs. The majority (average 55%) of Fos-positive neurons projecting to supraspinal sites were also located in the region of the SPN. A selective distribution of different types of neurons was detected in this region: PGN were located ventral to the spinal projection neurons which in turn were located ventral to the majority of unidentified Fos-positive neurons. The distribution of Fos-positive PGN and projection neurons was similar in spinal intact and spinal transected animals indicating that c- fos expression was mediated by monosynaptic afferent input or input from segmental interneurons and was not due to activation of supraspinal micturition reflex pathways.
The relationship between parental age, birth order and the secondary sex ratio in humans.

SUMMARY An analysis is made of the change in secondary sex ratio in humans as the ages of the parents increase, and also as the age of the mother and birth order increases. It is shown that both age of the father and birth order are significantly correlated with this change in sex ratio, whereas the age of the mother is not. The changes with increasing birth order and with increasing age of the father are so similar when properly compared, that they appear quite likely to be caused by the same underlying factor.
Anticipating electrical breakdown in dielectric elastomer actuators

The output strain of a dielectric elastomer actuator is directly proportional to the square of its applied electric field. However, since the likelihood of electric breakdown is elevated with an increased applied field, the maximum operating electric field of the dielectric elastomer is significantly derated in systems employing these actuators so that failure due to breakdown remains unlikely even as the material ages. In an effort to ascertain the dielectric strength so that stronger electric fields can be applied, partial discharge testing is used to assess the health of the actuator by detecting the charge that is released when localized instances of breakdown partially bridge the insulator. Pre-stretched and unstretched samples of VHB4910 tape were submerged in dielectric oil to remove external sources of partial discharges during testing, and the partial discharge patterns were recorded just before failure of the dielectric sample.
The Effect of Residual Calcium in Decalcified Freeze-dried Bone Allograft in a Critical-sized Defect in the Rattus norvegicus Calvarium

Demineralized freeze-dried bone allograft (DFDBA), a widely used graft material in periodontal regenerative procedures, is processed with hydrochloric acid in the attempt to expose proteins located within the bone matrixes that are capable of inducing new bone formation. However, the degree of DFDBA demineralization varies between tissue banks, which may have an effect on clinical regeneration. This study uses the critical-sized defect (CSD) model to evaluate the wound-healing response to the residual calcium of donor bone. If the percentage of residual calcium in a graft were demonstrated to significantly enhance wound healing, then periodontal patients may benefit from further standardization of human-allograft processing. Sixty adult, male, Harlan Sprague-Dawley rats (Rattus norvegicus) were randomly and equally divided into 4 test groups (ie, DFDBA at 1%, 2%, and 3% to 6% residual calcium levels and FDBA at 23% residual calcium) and a control group (no allograft). An 8-mm-diameter craniotomy was made in the rat calvarium, and polytetrafluoroethylene membranes with pore sizes of 0.50 microm were placed intracranially and ectocranially. Treatment materials were carefully placed into the CSD with a new sterilized dental amalgam carrier. Tetracycline hydrochloride was injected intraperitoneally for labeling new bone growth, and animals were euthanized 12 weeks postsurgery. As a result, histomorphometric bone fill at 12 weeks showed a statistically significant increase in the 2% DFDBA group as compared to all other groups. The authors conclude that a 2% residual calcium level in human DFDBA appears to significantly (P < or = .05) enhance osseous wound healing in the rat calvarium.
Extracellular modulation of the Hedgehog, Wnt and TGF-beta signalling pathways during embryonic development.

Localized embryonic expression of members of the Hedgehog, Wnt and TGF-β families of secreted factors has been shown to organize pattern and provide positional information in many developing systems. Recently, several extracellular factors have been described that act either as facilitators or inhibitors of the activities of those secreted proteins. The variety of molecular strategies involved in the extracellular modulation of signalling activities in the embryo underscores the importance of maintaining a tight spatial and temporal control of the activities of organizing centers during development.
Scanning mutagenesis of the Arc represser as a functional probe of operator recognition

Protein-DNA and protein-protein interactions are central to most biological regulation, and yet our understanding of these macromolecular recognition events is still incomplete. Both types of interactions are critical for the function of the Arc repressor. The functional importance of residues in or near its operator DNA-binding surface and dimer-dimer interaction surface has been probed by alanine-scanning mutagenesis. Mutations in three categories cause large binding defects: beta-sheet side chains that directly interact with DNA bases; side chains that link different DNA-binding regions of Arc, and side chains required to maintain the active DNA-binding conformation.
A study of the fine structure of ascosporogenesis in Saccobolus kerverni

Observations of ascospore fromation in KMnO4-fixed Saccobolus kerverni apothecia with the electron microscope reveal the following sequence. Ascus formation is preceded by the development of croziers whose fine structure differs little from that of vegetative hyphae. Following fusion of the two nuclei in the ascus mother cell, the resultant ascus elongates, and two large vacuoles appear, first below and later above the fusion nucleus. These vacuoles soon occupy dominant positions at the tip and bottom of the ascus and assume a flocculent appearance. Nuclear blebbing occurs during meiosis, mitosis, and the subsequent spore delimitation process in the central cytoplasmic portion of the ascus. Each spore initial is surrounded by two membranes, the plasma and investing membranes, between which the spore wall is deposited in two layers, an inner primary wall and an outer secondary wall. Following primary wall deposition the spores clump; secondary wall deposition begins outside the primary wall at the places where the spores are contiguous. Interdigitation of these walls and disappearance of the investing membranes in the sutures lead to the envelopment of all eight ascospores in a common secondary wall. A flocculent material in the epiplasmic vacuoles aggregates around the mature spore balls.
Relationship between pectin methylesterase activity and the formation of methanol in Concord grape juice and wine

Abstract Pectin methylesterase (PME) activity in grapes was studied. Concord grape PME has optimum activity at pH 7·5 and the activity was the highest among several grape varieties tested. PME activity in Concord grapes increased continuously throughout the maturation period and reached a maximum at harvest. Consequently, this reflected the large amount of methanol formation during wine fermentation.
Control of cattle grubs with dichlorvos-impregnated strips attached to legs of cattle.

Cattle treated by attaching strips of polyvinyl chloride impregnated with 20% dichlorvos around their legs during the season (Jan.–May) when adult flies are active were examined for encapsulated Hypoderma lineatum (Villers) the following fall-winter. Treatments, consisting of 5 g dichlorvos/leg, gave essentially complete control (98–100%) whether all legs or only rear legs were treated and whether or not treatments were renewed in Mar. Treatments of 2.5 g dichlorvos/leg gave 100% control if the treatments were renewed in Mar. but only 91% control if they were not.
A microinstability code for a uniform magnetized plasma with an arbitrary distribution function

Abstract We have developed a very general computer code for studying microinstabilities in a uniform magnetized plasma. Employing a new algorithm to perform two-dimensional numerical integrals in the conductivity tensor, the code can handle an arbitrary distribution function given by either an analytical function or numerical values on a momentum space grid and solve the full dispersion relation for an arbitrary propagation angle in either a non-relativistic or relativistic plasma except for a highly relativistic plasma (energy ⪢ 1 MeV). The results for cyclotron-maser instability and whistler-wave instability are presented to illustrate the validity of the method.
Effects of substrate nitrate concentration on symbiotic nodule formation in actinorhizal plants

The response ofAlnus glutinosa, Casuarina cunninghamiana, Elaeagnus angustifolia andMyrica cerifera to a range of substrate nitrogen levels in solution, in relation to plant growth, infection, nodulation and root fine structure was studied. Nine concentrations of potassium nitrate ranging from 0.05 to 3.0 mM, were tested on each of the species. Plants were inoculated withFrankia pure cultures after a two week exposure to one of the nine levels of added nitrate. After six more weeks with constant exposure to nitrate, plants were harvested and assayed. With the exception of Myrica, regression analyses of whole plant dry weights as a function of added nitrate were highly significant. There was a tendency for nodulated plants grown at intermediate levels of added nitrate to exhibit higher relative growth rates, probably due to the additive effect of substrate nitrogen and fixation of atmospheric nitrogen. The mean numbers of nodules per plant were, with the exception of Alnus, significantly higher at intermediate levels of added nitrate, as were mean nodule dry weights. A highly significant inverse relationship between nodule weight as a percentage of whole plant weight was found in Elaeagnus and Myrica. The observed response of Elaeagnus to added nitrate compared to other actinorhizal plants appears to demonstrate that root hair infected plants are much more sensitive to the inhibitory effects of added nitrate than plants infected by intercellular penetration. A sharp reduction in the presence of root hairs at high concentrations of nitrate was observed. This indicates that the inhibition of nodulation in some actinorhizal plant species results from nitrate induced root hair suppression.
Transient Focal Cerebral Ischemia Induces a Dramatic Activation of Small Ubiquitin-Like Modifier Conjugation

This study was designed to investigate whether small ubiquitin-like modifier (SUMO) conjugation is activated after focal cerebral ischemia. Transient ischemia induced a dramatic increase in SUMO2/3 protein conjugates. The most pronounced changes were found in the parietal cortex. SUMO2/3 conjugation was particularly high in neurons located at the border of the middle cerebral artery territory where sumoylated proteins translocated to the nucleus. Considering the marked effect of SUMO conjugation on the function of target proteins, it is very likely that the postischemic activation of sumoylation has a significant effect on the fate of neurons exposed to transient ischemia.
Tuning the Polarizability in Donor Polymers with a Thiophenesaccharin Unit for Organic Photovoltaic Applications

This paper describes the synthesis of low bandgap copolymers incorporating an artificial sweetener derivative, N-alkyl, 3-oxothieno[3,4-d]isothiazole 1,1-dioxide (TID). This new TID unit is identical to the well-known thieno[3,4-c]pyrrole-4,6-dione (TPD) unit except that one carbonyl has been replaced by a sulfonyl group. Semi-empirical calculations on the local dipole moment change between ground and excited states (Δμge) in the repeating units of the new polymer indicate that the replacement of the carbonyl by a sulfonyl group leads to larger Δμge values. The resulting polymers exhibit a diminished power-conversion efficiency (PCE) compared to a bulk heterojunction (BHJ) solar cells with PC71BM as an acceptor, which extends the correlation between PCE and Δμge of single repeating units in p-type polymers to a new regime. Detailed studies show that the strongly electron-withdrawing sulfonyl group is detrimental to charge separation in alternating copolymers containing a TID unit.
Do male and female beetles (Tenebrio molitor) respond differently to rat feces containing eggs from the tapeworm, Hymenolepis diminuta?

Males and females often differ in their susceptibility and exposure to infection. Thus, they may also differ in their ability to avoid infection. The beetle, Tenebrio molitor, risks infection with cysticercoids when ingesting rat feces containing eggs of the tapeworm, Hymenolepis diminuta. Previous studies demonstrated that beetles sometimes prefer infective feces suggesting that the tapeworm influences the foraging behavior of beetles. After recording beetle movement in an arena containing infective and uninfective feces for one hour, sex main effects were not significant, but the effect of sex asked in trials was significant for males. Specifically, more male beetles occurred on the uninfective bait than on the infective bait. This observation suggests that male beetles avoid infective feces, which decreases their probability of infection with H. diminuta. If the cost of infection is higher in males, then selection to avoid infective feces may act more strongly on males.
A computer assisted study of uniqueness of ground state solutions

For the problem (here u=u(x)) @Du-u^p+@au^q+@bu^r=0,x@?R^n,lim|x|->~u(x)=0, with constants 1@?p0, uniqueness of radial solution (calledground state solution) is not known. We present a procedure, which opens the way to produce computer assisted proofs of uniqueness for specific p, q, r, and n.
Evidence that an excitatory connection between the periaqueductal gray and nucleus raphe magnus mediates stimulation produced analgesia.

Both electrical stimulation and injection of morphine into the midbrain periaqueductal gray (PAG) produce analgesia in the rat. There is evidence that this analgesic effect is mediated by a descending system that involves nucleus raphe magnus (NRM) and adjacent reticular formation. In the studies reported here, the activity of the cells in the PAG was increased by microinjection of glutamate in this area and its effect on both the activity of single cells in the NRM and on a flexion reflex elicited by noxious heat was measured. It is shown that an increase in the firing rate of the cells in the PAG is associated with a raised threshold for flexion and is also correlated with an increase in the firing rate of a majority of the cells in the NRM. This effect on the flexion reflex can be abolished by (a) lesion of the nucleus raphe magnus and a small area of the reticular formation surrounding this nucleus and (b) by nalazone 20 min after its i.v. injection. It is concluded that there is an excitatory connection between the periaqueductal gray and the nucleus raphe magnus and that activation of this system can cause analgesia.
Zeeman effect and intensity anomalies in PbI.

Spectrograms of 208Pb electrodeless discharge tubes operated in a field of 24025 gauss gave Zeeman patterns for fifty-eight PbI spectral transitions from 2189 to 10969 A and yielded eighteen new g values. There was good agreement between these and the g values predicted by intermediate-coupling eigenvectors determined from least-squares level fitting. The g value of the odd level at 58517 cm−1 indicates that it belongs to the 6p6d configuration instead of 6s6p3 as formerly classified.A striking consequence of configuration interaction has been discovered which results in the total suppression of what would otherwise be a strong line in this spectrum. A predominantly 6p6d level is mixed with 6p7s and interference between the dipole matrix elements connecting respectively the 6d and 7s portions with a ground-state level causes a net dipole moment of almost exactly zero for this transition. However, even in our relatively weak magnetic field, this balance is upset by magnetic mixing of only 0.3% with a third level to enhance the line strength by at least a factor 106! Two related transitions with normal pattern separations display pronounced anomalies in the relative intensities of their Zeeman components. We give a theoretical analysis and quantitative calculations to show that these anomalies are due to combined interference effects of the two types of mixing.
Comparative ecology of catfishes of the Upper Zambezi River floodplain

An 8-month survey of the Upper Zambezi River, its associated floodplain and marginal upland habitats yielded 16 catfish (Siluriformes) species, among which Schilbe intermedius comprised over half of the 3534 specimens. Generally catfishes were most abundant in floodplain and river channel habitats, but three species (Clariallabes platyprosopos, Synodontis macrostoma, S. nigromaculatus) were most abundant in the river channel, and three species (Amphilius uranoscopus, Chiloglanis neumanni, Leptoglanis rotundiceps) were most abundant or restricted within small tributary streams. Diet analysis revealed low pairwise dietary overlaps, but there was no statistically significant pattern of community-wide niche segregation based on prey type. The 16 catfishes fell into four size/trophic guilds: large carnivores (Clarias gariepinus, C. ngamensis), medium-sized carnivores (C. stappersii, C. theodorae, Parauchenoglanis ngamensis, Clariallabes platyprosopos, Schilbe intermedius), medium-sized omnivores (Synodontis leopardinus, S. nigromaculatus, S. woosnami, S. sp. cf. woosnami), and small omnivores (S. macrostigma, S. macrostoma, Amphilius uranoscopus, Chiloglanis neumanni, Leptoglanis rotundiceps). No evidence of reproductive activity was detected in any of the catfishes during the survey period of falling and low water conditions. Although catfishes are not as highly valued for food as cichlid fishes, three species are significant components of local commercial and subsistence fisheries: the two large Clarias by virtue of their size, and Schilbe by virtue of its great abundance. Abundances of the heavily exploited Clarias gariepinus and C. ngamensis stocks appear to be lower in the Upper Zambezi compared with the Okavango floodplain system.
1,12-Diferrocenyldodecane at 100 K

1,12-Diferrocenyldo­decane, [Fe2(C5H5)2(C22H32)], was synthesized from ferrocene and 1,12-do­decane­dioyl chloride, followed by Clemmensen reduction. The single-crystal structure was determined at 100 K by X-ray diffraction and the spectroscopic and cyclic voltammetric data of 1,12-diferrocenyldo­decane and its precursor are reported.
19F NMR of 5-fluorouracil-substituted transfer RNA transcribed in vitro: resonance assignment of fluorouracil-guanine base pairs.

Abstract 5-Fluorouracil is readily incorporated into active tRNA(Val) transcribed in vitro from a recombinant phagemid containing a synthetic E. coli tRNA(Val) gene. This tRNA has the expected sequence and a secondary and tertiary structure resembling that of native 5-fluorouracil-substituted tRNA(Val), as judged by 19F NMR spectroscopy. To assign resonances in the 19F spectrum, mutant phagemids were constructed having base changes in the tRNA gene. Replacement of fluorouracil in the T-stem with cytosine, converting a FU-G to a C-G base pair, results in the loss of one downfield peak in the 19F NMR spectrum of the mutant tRNA(Val). The spectra of other mutant tRNAs having guanine for adenine substitutions that convert FU-A to FU-G base pairs all have one resonance shifted 4.5 to 5 ppm downfield. These results allow assignment of several 19F resonances and demonstrate that the chemical shift of the 19F signal from base-paired 5-fluorouracil differs considerably between Watson-Crick and wobble geometry.
Simulation of a spin glass with Dzyaloshinsky-Moriya interactions

Abstract The effect of Dzyaloshinsky-Moriya interactions on the transverse susceptibility and the EPR modes of spin glasses is calculated using the Monte Carlo methods of Walstedt and Walker.
Local Electronic Structure and Stability of Pentacene Oxyradicals

A series of pentacene oxyradicals is studied as a model of an oxidized graphene edge. The relative stability of the oxyradical species formed is rationalized on the basis of the concept of local aromaticity. It is found that qualitative and quantitative measures of delocalized bonding show consistently that formation of the π-aromatic fragments associated with different reference π-aromatic systems explain trends in Gibbs free energies and relative energies. As a result, a chemically intuitive model based on aromaticity can explain the relative stability of the oxyradicals in a way that uniquely appeals to chemists’ knowledge of structure and reactivity.
Capturing proteins that bind polyunsaturated fatty acids: demonstration using arachidonic acid and eicosanoids.

Polyunsaturated fatty acids (PUFA) and their biological derivatives, including the eicosanoids, have numerous roles in physiology and pathology. Although some eicosanoids are known to act through receptors, the molecular actions of many PUFA remain obscure. As the three-dimensional structure of eicosanoids allows them to specifically bind and activate their receptors, we hypothesized that the same structure would allow other proteins to associate with PUFA and eicosanoids. Here, we demonstrate that biotinylation of arachidonic acid and its oxygenated derivatives 5-hydroxyeicosatetraenoic acid (5-HETE) and leukotriene (LT) B4 can be used to pull down associated proteins. Separation of proteins by two-dimensional gel electrophoresis indicated that a large number of proteins bound each lipid and that proteins could distinguish between two enantiomers of 5-HETE. Individual proteins, identified by matrix assisted laser desorption/ionization-time of flight mass spectrometry, included proteins that are known to bind lipids, including albumin and phosphatidylethanolamine-binding protein, as well as several novel proteins. These include cytoskeletal proteins, such as actin, moesin, stathmin and coactosin-like protein, and G protein signaling proteins, such as Rho GDP dissociation inhibitor 1 and nucleoside diphosphate kinase B. This method, then, represents a relatively simple and straightforward way to screen for proteins that directly associate with, and are potentially modulated by, PUFA and their derivatives.
Behavioral Stress May Increase the Rewarding Valence of Cocaine-Associated Cues Through a Dynorphin/ κ -Opioid Receptor-Mediated Mechanism without Affecting Associative Learning or Memory Retrieval Mechanisms

Stress exposure increases the risk of addictive drug use in human and animal models of drug addiction by mechanisms that are not completely understood. Mice subjected to repeated forced swim stress (FSS) before cocaine develop significantly greater conditioned place preference (CPP) for the drug-paired chamber than unstressed mice. Analysis of the dose dependency showed that FSS increased both the maximal CPP response and sensitivity to cocaine. To determine whether FSS potentiated CPP by enhancing associative learning mechanisms, mice were conditioned with cocaine in the absence of stress, then challenged after association was complete with the κ-opioid receptor (KOR) agonist U50,488 or repeated FSS, before preference testing. Mice challenged with U50,488 60 min before CPP preference testing expressed significantly greater cocaine–CPP than saline-challenged mice. Potentiation by U50,488 was dose and time dependent and blocked by the KOR antagonist norbinaltorphimine (norBNI). Similarly, mice subjected to repeated FSS before the final preference test expressed significantly greater cocaine–CPP than unstressed controls, and FSS-induced potentiation was blocked by norBNI. Novel object recognition (NOR) performance was not affected by U50,488 given 60 min before assay, but was impaired when given 15 min before NOR assay, suggesting that KOR activation did not potentiate CPP by facilitating memory retrieval or expression. The results from this study show that the potentiation of cocaine–CPP by KOR activation does not result from an enhancement of associative learning mechanisms and that stress may instead enhance the rewarding valence of cocaine-associated cues by a dynorphin-dependent mechanism.
What do college students know about the ocean

A recent survey of students entering a college-level course in introductory oceanography reveals that they feel a strong connection with, and curiosity about, the ocean. To guide this inherent curiosity into understanding and stewardship, educators need to know the ‘hooks,’ the topics and concepts that catch students' interests. According to a survey of 119 students at North Carolina State University-Raleigh, some useful hooks are students' personal, emotional connection with the ocean, human impacts (especially pollution), exotic biology and cool technology. Survey results further indicate that students already are gaining ocean knowledge from a wide variety of sources, and that the topics of interest to them can be organized using the Essential Principles of Ocean Literacy [Centers for Ocean Sciences Education Excellence (COSEE), 2005]. The students' general awareness of ocean science is a good basis upon which to build.
Isolated congenital pseudarthrosis of the fibula

An otherwise healthy 1-year-old boy with normal developmental milestones was seen for external rotation of the right foot. On examination the right foot was slightly abducted and externally rotated; initial concern was for calcaneal valgus deformity. Plain radiographs (Fig. 1) showed a pseudarthrosis at the distal fibula. The tibia was normal. In view of a strong family history of neurofibromatosis, a diagnosis of isolated congenital pseudarthrosis of the fibula was made. Isolated congenital pseudarthrosis of the fibula is uncommon and has varying degrees of severity as described by Dooley et al [1]. It can be seen in patients with neurofibromatosis type 1 (NF1), as was likely with this child who had a the strong family history. Another possible diagnosis was fibrous dysplasia. Pseudarthrosis in NF1 is most commonly present in the tibia and radius and infrequently affects the fibula alone. The lesion can cause severe bowing deformity, and surgical intervention is often necessary for management [2]. Plain radiographs are often diagnostic.
A linear-time algorithm for finding optimal vehicle refueling policies

We explore a fixed-route vehicle refueling problem as a special case of the inventory-capacitated lot-sizing problem, and present a linear-time greedy algorithm for finding optimal refueling policies.
Replication-competent herpes virus NV1020 as direct treatment of pleural cancer in a rat model.

Abstract Objective: Innovative treatments are needed for metastatic disease involving the pleura. NV1020 is a novel, multimutated, replication-restricted herpes simplex virus under investigation for its ability to selectively kill tumors by means of direct cell lysis. This study examines NV1020 in a rat model of pleura-based lung cancer. Methods: Cytotoxicity and viral proliferation were evaluated in vitro by exposure of the human non-small cell lung cancer cell line A549 to virus. NV1020 was also tested in an in vivo pleura-based cancer model established by injecting 1 × 10 7 A549 cells into the thoracic cavity of nude rats. Intrapleural treatments (1 × 10 7 viral particles) were given 3 hours or 3 days after tumor injection to model treatment of microscopic or macroscopic disease (n = 8-9/group). Tumor burden was assessed at 5 weeks. NV1020 infection and dissemination within the thoracic cavity was determined by means of immunohistochemistry. Results: In vitro, at multiplicities of infection (viral particles per tumor cell) of 0.01, 0.1, and 1.0, cell killing of A549 by NV1020 was 66%, 90%, and 97%, respectively, at 7 days after infection. Viral burst occurred by day 2. Intrapleural treatment was effective for both the microscopic ( P P Conclusions: NV1020 is not only highly cytotoxic to the human lung cancer line A549 in vitro but can be delivered in a clinically relevant fashion to safely and effectively treat pleura-based tumor in vivo in a rat model. J Thorac Cardiovasc Surg 2002;124:123-9
Detection of bacterial antigens and Alzheimer’s disease-like pathology in the central nervous system of BALB/c mice following intranasal infection with a laboratory isolate of Chlamydia pneumoniae

Pathology consistent with that observed in Alzheimer’s disease (AD) has previously been documented following intranasal infection of normal wild-type mice with Chlamydia pneumoniae (Cpn) isolated from an AD brain (96-41). In the current study, BALB/c mice were intranasally infected with a laboratory strain of Cpn, AR-39, and brain and olfactory bulbs were obtained at 1-4 months post-infection (pi). Immunohistochemistry for amyloid beta or Cpn antigens was performed on sections from brains of infected or mock-infected mice. Chlamydia-specific immunolabeling was identified in olfactory bulb tissues and in cerebrum of AR-39 infected mice. The Cpn specific labeling was most prominent at 1 month pi and the greatest burden of amyloid deposition was noted at 2 months pi, whereas both decreased at 3 and 4 months. Viable Cpn was recovered from olfactory bulbs of 3 of 3 experimentally infected mice at 1 and 3 months pi, and in 2 of 3 mice at 4 months pi. In contrast, in cortical tissues of infected mice at 1 and 4 months pi no viable organism was obtained. At 3 months pi, only 1 of 3 mice had a measurable burden of viable Cpn from the cortical tissues. Mock-infected mice (0 of 3) had no detectable Cpn in either olfactory bulbs or cortical tissues. These data indicate that the AR-39 isolate of Cpn establishes a limited infection predominantly in the olfactory bulbs of BALB/c mice. Although infection with the laboratory strain of Cpn promotes deposition of amyloid beta, this appears to resolve following reduction of the Cpn antigen burden over time. Our data suggest that infection with the AR-39 laboratory isolate of Cpn results in a different course of amyloid beta deposition and ultimate resolution than that observed following infection with the human AD-brain Cpn isolate, 96-41. These data further support that there may be differences, possibly in virulence factors, between Cpn isolates in the generation of sustainable AD pathology.
A NUMERICAL ANALYSIS OF CAPACITATED POSTPONEMENT

Customer satisfaction can be achieved by providing rapid delivery of a wide variety of products. High levels of product variety require correspondingly high levels of inventory of each item to quickly respond to customer demand. Delayed product differentiation has been identified as a strategy to reduce final product inventories while providing the required customer service levels. However, it is done so at the cost of devoting large production capacities to the differentiation stage. We study the impact of this postponement capacity on the ability to achieve the benefits of delayed product differentiation. We examine a single-period capacitated inventory model and consider a manufacturing system that produces a single item that is finished into multiple products. After assembly, some amount of the common generic item is completed as non-postponed products, whereas some of the common item is kept as in-process inventory, thereby postponing the commitment to a specific product. The non-postponed finished-goods inventory is used first to meet demand. Demand in excess of this inventory is met, if possible, through the completion of the common items. Our results indicate that a relatively small amount of postponement capacity is needed to achieve all of the benefits of completely delaying product differentiation for all customer demand. This important result will permit many firms to adopt this delaying strategy who previously thought it to be either technologically impossible or prohibitively expensive to do so.
Direct observation of dislocation emission from crack tips in silicon at high temperatures

Abstract The emission of dislocations from crack tips in silicon under combined conditions of temperature and stress is observed in situ at 550–750°C, using transmission electron microscopy. The generation and motion of 1 2 [110] shear dislocation loops on (111) planes, corresponding to those having the maximum Schmid factor, occurs in both mode I and mode III cases. Estimation of the emission condition is made based on the observed dislocation mobility and resultant distribution of dislocations around the crack tip. The difference in the values of K1 = 0.94 ± 0.06 MPa m 1 2 and Km = 0.17± 0.03 MPa m 1 2 for dislocation emission is attributed to Schmid factor differences and ledge energy effects. Substituting the estimated stress intensity, resolved on to the dislocation emission glide plane, into the Rice-Thomson energy analysis indicates that spontaneous dislocation emission occurs without a nucleation barrier. A value for the lattice friction stress of ~ 110 MPa is deduced from the positions around the crack tips that the dislocations adopt after emission. In a modification of the Rice-Thomson energy analysis, the lattice friction stress is shown to influence the nucleation and growth to a stable size of a dislocation loop emitted from a crack tip.
Similarity in Sensation-Seeking, Sexual Satisfaction and Contentment in Relationship in Heterosexual Couples

Data from 31 college students and their long-term partners in intimate relationships indicated that similarity in sensation-seeking on Zuckerman's scale was positively and moderately correlated with scores on Traupman, Hatfield, and Wexler's measures of sexual satisfaction and contentment in relationship.
Modeling of wind power plant collector system in power system planning stability studies

The paper discusses modeling of the collector system of a wind power plant in power system planning stability studies. Numerical experiments performed for a variety of wind turbine generator (WTG) devices use their vendor-specific stability models and are run on large power system databases assuming realistic contingency scenarios. Simulations have provided evidence that collector system aggregation can affect fault ride through capability assessment. In particular, the assessment of percentage of the total plant capacity remaining online post-contingency can change; the use of a single WTG equivalent does not necessarily ensure the worst case scenario. Due to concerns about the trustworthiness of some vendor-specific WTG stability models, further analyses based on EMTP-type simulation tools are needed. Meanwhile, it is recommended that a planning stability study include sensitivity analysis to justify the level of collector aggregation.
Separating lines of text in free-form handwritten historical documents

We present an approach to finding (and separating) lines of text in free-form handwritten historical document images. After preprocessing, our method uses the count of foreground/background transitions in a binarized image to determine areas of the document that are likely to be text lines. Alternatively, an adaptive local connectivity map (ALCM) found in the literature can be used for this step of the process. We then use a min-cut/max-flow graph cut algorithm to split up text areas that appear to encompass more than one line of text. After removing text lines containing relatively little text information (or merging them with nearby text lines), we create output images for each line. A grayscale output image is created, as well as a special mask image containing both the foreground and information flagging ambiguous pixels. Foreground pixels that belong to other text lines are removed from the output images to provide cleaner line images useful for further processing. While some refinement is still necessary, the result of early experimentation with our method is encouraging.
Adsorption and reaction pathways of a chiral probe molecule, S-glycidol on a Pd(111) surface

The chemistry of S-glycidol is studied on a Pd(111) surface using temperature-programmed desorption and reflection–absorption infrared spectroscopy to explore its suitability as a chiral probe molecule and to follow its reaction pathway. It is found that the majority of the S-glycidol desorbs intact with less than ~8% decomposing. Decomposition is initiated by forming an S-glycidate intermediate below ~200 K and this further reacts via C–O scission of the epoxy ring. This reaction is controlled by the stability of the carbocation intermediate to preferentially form an ethoxy aldehyde intermediate that thermally decomposes to desorb carbon monoxide, hydrogen and ethanol.
Use of a Metallopeptide-Based Mimic Provides Evidence for a Proton-Coupled Electron-Transfer Mechanism for Superoxide Reduction by Nickel-Containing Superoxide Dismutase†

Sneaky little SOD! A metallopeptide-based mimic of nickel-containing superoxide dismutase was used to probe the mechanism of superoxide reduction by the metalloenzyme. Kinetic studies suggest a proton-coupled electron-transfer mechanism; large H/D kinetic isotope effects (KIE) are observed. XAS studies suggest the transferred H-atom is in the form of a Ni(II) -S(H)-Cys moiety.
Nanotechnology-based delivery systems in HIV/AIDS therapy

The therapeutic efficacy of anti-HIV agents is often hampered by poor bioavailability and lack of drug penetration in infected target tissues and cells. Using different types of nanotechnology-based delivery systems, it is possible to engineer strategies that can improve the therapeutic efficacy in HIV/AIDS by delivering drugs to cellular and anatomical viral reservoirs. The rationale for the use of nanocarrier systems relies on the fact that different types of therapeutic payloads can be encapsulated and the systemic pharmacokinetics and distribution are dictated by the properties of the nanocarriers rather than the drugs. The versatility of nanoplatforms can be further exploited in a formulation that has enhanced oral bioavailability, protects against degradation upon oral or systemic administration and prolongs the residence time at the target site. Nanocarriers can facilitate lymphatic transport, delivery across the blood–brain barrier, and efficient internalization in cells by nonspecific or receptor...
Progress in computational electromagnetic modeling for EM courseware: a personal perspective at Penn State

Summary form only given. Recent advances in computational electromagnetic modeling make it possible to provide students with interactive, color visualization of complex 3-D phenomena on personal workstations in real time at reasonable cost. The advances are: the computational engines available, where the finite-difference time-domain (FDTD) techniques have been found to be the most advantageous; the availability of powerful workstations with extensive color graphics support, operating in the multi-megaflop regime; and an emerging environment of courseware development support from a host of groups and agencies, including CAEME (computer applications in electromagnetics education) and ECSEL, which permits development of student friendly interfaces or shells. The interface provides multiple problem types with a hierarchical level of problem sophistication ranging from demonstrations to tutorials to independent student design efforts. The student selects the problem type and the level of difficulty or interactivity suitable to his or her experience, inputs the required variables, and then watches as the system responds in time to the selected stimulus in the form of real-time graphical display of the fields and interaction object. >
Clostridium difficile colitis in the hospital setting: a potentially explosive problem.

Pseudomembranous enterocolitis was first described long before the antibiotic era by Coats in 1883.1 Initially, this clinical syndrome was recognized in postoperative hospitalized patients, and because of its distinctive pseudomembrane, it was termed postoperative diphtheritic enteritis in 1893 by Finney.2 Shortly after the introduction of antibiotics, there were several cases of a presumably new clinical syndrome of severe enteritis with extensive pseudomembrane formation in patients receiving antibiotics.3 This was called antibioticassociated pseudomembranous colitis. In the first reported cases, necropsy revealed enteritis with pseudomembranes under which pure cultures of Staphylococcus aureus usually could be isolated. It was reasoned that antibiotic use allowed the overgrowth of S aureus, which then produced a toxic enterocolitis.4 This supposition was strengthened by the observations of staphylococcal-induced enterocolitis in an animal model.5 However, doubt was cast upon this hypothesis by noting that the syndrome had first been described in the pre-antibiotic era and that identical enterocolitis had been found in patients whose stool cultures did not grow staphylococci.6 The role of S aureus in enterocolitis is still controversial; cases may occur, particularly with "toxic shock" strains, but these appear to be exceedingly rare. The etiology of most cases of pseudomembranous enterocolitis began to be unraveled when Larson and colleagues reported a nondialyzable heat-labile cytotoxin in the stools of five of six patients with antibiotic-associated pseudomembranous colitis.? Using a hamster model described by Small,8 the