cssi/SciSciGPT-SciSciNet huggingface dataset:
Autism and Pervasive Developmental Disorders

Publisher Summary This chapter discusses pervasive developmental disorders (PDD) and autism. The most notable research activity during recent years is the explosion of new autism-specific screening measures, such as the Modified Checklist for Autism in Toddlers (M-CHAT) and the Pervasive Developmental Disorders Screening Test-II (PDDST-II), available for use during routine developmental surveillance. These instruments are designed to enhance recognition of children at risk for autism either in the general population or in groups of children already identified as being at risk for developmental disabilities. In the absence of biological markers, researchers have been forced to focus efforts on discovering clinical symptoms of autism that at best allow differentiation and at minimum serve as red flags during the first year of life. Training and outreach models, such as Project First STEP (Screening, Training, Education Project) transfer available surveillance and screening technologies into clinical practice. Such endeavors are likely to produce a cascade of effects, including increasing referrals of children at risk and lowering the age at which referrals are made, which may result in lowering the age at which evidence-based early intervention begins and maximizing developmental trajectories of children with autism.
Global DNA methylation as a biomarker to screen asymptomatic individuals who are at-risk of developing lung cancer

A99 Lung cancer is the leading cause of cancer death for both men and women because symptoms of the disease usually present when it is at an advanced stage. Improved diagnosis will increase the survival rate, which currently is 15% over 5 years. With 45 million smokers in the US who are at-risk of developing the disease, there is an urgent need for a screening tool that can detect the early stages of lung cancer progression in the asymptomatic population.We have developed an assay, CpGlobal, which measures the global DNA methylation of the human genome. Global DNA methylation is measured by monitoring the sentinels of genome integrity, CpG dyads, which are markers for the susceptibility of developing cancer. Changes in methylation at these locales represent the earliest events in the progression toward a disease state. CpGlobal is performed in a 96 well format, requires
The role of menstrual cycle phase and anxiety sensitivity in catastrophic misinterpretation of physical symptoms during a CO(2) challenge.

The current study examined the interactive effects of anxiety sensitivity (AS; fear of anxiety and anxiety-related sensations) and menstrual cycle phase (premenstrual phase vs. follicular phase) on panic-relevant responding (i.e., cognitive and physical panic symptoms, subjective anxiety, and skin conductance level). Women completed a baseline session and underwent a 3-min 10 % CO2-enriched air biological challenge paradigm during her premenstrual and follicular menstrual cycle phases. Participants were 55 women with no current or past history of panic disorder recruited from the general community (M age = 26.18, SD = 8.9) who completed the biological challenge during both the premenstrual and follicular cycle phases. Results revealed that women higher on AS demonstrated increased cognitive panic symptoms in response to the challenge during the premenstrual phase as compared to the follicular phase, and as compared to women lower on AS assessed in either cycle phase. However, the interaction of AS and menstrual cycle phase did not significantly predict physical panic attack symptoms, subjective ratings of anxiety, or skin conductance level in response to the challenge. Results are discussed in the context of premenstrual exacerbations of cognitive, as opposed to physical, panic attack symptoms for high AS women, and the clinical implications of these findings.
Unique presynaptic and postsynaptic roles of Group II metabotropic glutamate receptors in the modulation of thalamic network activity

The thalamic reticular nucleus (TRN) is a sheet of GABAergic neurons that project to other TRN neurons and to associated thalamocortical relay nuclei. The TRN receives glutamatergic synaptic inputs from cortex as well as reciprocal inputs from the collaterals of thalamocortical neurons. In addition to ionotropic glutamate receptors, metabotropic glutamate receptors (mGluRs) are present in the TRN circuitry. Using whole cell voltage clamp recordings, we pharmacologically characterized unique pre- and postsynaptic functions for Group II mGluRs (mGluR 2 and mGluR 3) within the TRN circuitry in ferrets. mGluR 2 was found on presynaptic cortical axon terminals in the TRN, where it reduced glutamate release, while mGluR 3 acted postsynaptically on TRN cells to increase membrane conductance. Using miniature inhibitory postsynaptic current analysis, we also found that picrotoxin-sensitive intra-TRN GABA-mediated neurotransmission was not affected by administration of a Group II mGluR agonist, indicating that neither mGluR 2 nor 3 acts on presynaptic GABA-containing terminals within the TRN. Because strong corticothalamic activation is implicated in abnormal thalamic rhythms, we used extracellular recordings in the lateral geniculate nucleus to study the effect of Group II mGluR agonists upon these slow oscillations. We induced approximately 3 Hz spike-and-wave discharge activity through corticothalamic stimulation, and found that such activity was reduced in the presence of the Group II mGluR agonist, (-)-2-oxa-4-aminobicyclo[3.1.0]hexane-4,6-dicarboxylate (LY379268). These data indicate that Group II mGluR reduce the impact of corticothalamic excitation, and that they may be a useful target in the reduction of absence-like rhythms.
The role of animal-vegetal interaction with respect to the determination of dorsoventral polarity in the equal-cleaving spiralian,Lymnaea palustris

Spirally cleaving embryos in which the first two cleavages generate four equal-sized blastomeres remain radially symmetrical along their animal-vegetal axis until the interval between third and fourth quartet formation. At this time animal micromeres and vegetal macromeres contact each other as they elongate and occlude the central, fluid-filled cleavage cavity. The overlying micromeres focus their contacts onto one of the four macromeres, the presumptive 3D macromere, as it elongates to a central position within the embryo. We tested the hypothesis that this animal-vegetal interaction was causally involved in the determination of the symmetry properties in both the animal and vegetal hemispheres by reversibly inhibiting animal-vegetal contact at the 24 cell stage with cytochalasin-B. Embryos remained hollow throughout the treatment period and animal-vegetal interaction did not occur. After treatment, blastomere elongation occurred but no D quadrant macromere appeared and the vegetal hemisphere remained radialized. On the basis of cleavage and ciliation patterns of first quartet derivatives, treated embryos remained fully or partially radialized, showing a strong tendancy to develop as ventral quadrants. These results show that the quadrants of this equal-cleaving spiralian are not definitively determined until after the 24 cell stage and that animal-vegetal interaction is required for D quadrant determination. The mechanisms of symmetrization in the animal and vegetal hemispheres of equal-cleaving spiralians is also discussed.
Trying to keep children out of trouble: Child characteristics, neighborhood quality, and within-household resource allocation.

Abstract Prior ethnographic evidence suggests that parents combat neighborhood dangers through spending time with and money on children perceived to be at risk. This paper summarizes a secondary data investigation of whether interactions between neighborhood quality and child characteristics predict patterns of intra-household resource allocation. Using a sample of N = 1879 12- and 13-year-olds from the National Longitudinal Survey of Youth, I find that in neighborhoods with greater numbers of problems, parents spend more time and money with firstborn children and children who are particularly short or impulsive relative to how parents treat such children in lower problem neighborhoods. Comparisons of cross-sectional and sibling fixed-effect models suggest the shortness and firstborn effects are not due to unobserved family characteristics. These results lend modest support to the assertion that parents systematically try to use within-family resources to protect certain children from threats posed by neighborhoods with high levels of crime or low levels of social cohesiveness.
Benzene metabolism by the isolated perfused lung.

Benzene is an occupational hazard and environmental toxicant whose toxic effects are dependent on its metabolism by cytochrome P-450. Most physiologically based pharmacokinetic models assume that benzene is metabolized only in the liver. They may not be completely accurate in predicting metabolism, especially following inhalation exposure, if metabolism by the lung is important. In the current study, the metabolizing capability of the lung was examined in an in vivo simulation using the isolated perfused lung. Lungs from the rabbit, rat, and mouse were used to mimic benzene metabolism following exposure via the pulmonary vasculature. With the isolated perfused mouse lung, three concentrations (55 µ M, 120 µ M, and 200 µ M) were used to evaluate concentration dependence. To evaluate the ability of the lung to metabolize inhaled benzene, the isolated perfused mouse lung was exposed to benzene (~175 ppm) via the trachea. Benzene was metabolized in all species, with phenol being the major metabolite. Phenylsu...
Learning from the folly of others: Learning to self-correct by monitoring the reasoning of virtual characters in a computer-supported mathematics learning environment

Two studies examined the social basis of self-assessment for learning through the application of creative computer tools that can help students assess and self-correct their own learning. Students are not usually inclined to check their own answers, but they find it relatively motivating to catch other people's mistakes. A total of 62 students, ranging in age from nine to 11, participated in two studies that tested the hypothesis that monitoring ''someone'' else (i.e., computer character) can help students learn to self-assess their own learning. Two computer-supported learning environments, i.e., ''Doodle Math'' and ''Puzzle Math,'' were developed as training environments for monitoring. The environments also allowed a direct comparison between self training and self-other training. In the training environment, a computer character, ''ProJo,'' openly displayed its reasoning when solving math problems and allowed children to ''look for mistakes.'' The students in self training solved all the problems on their own, while the students in self-other training worked with the computer character, ProJo, taking turns to solve problems and monitor for any mistakes. The measures on calculation time and accuracy showed that self-other training might be an effective way to help students develop metacognitive skills to self-correct and improve performance in elementary mathematics. The log file tracked the students' progress in various data forms and displayed evidence that self-other training students monitored and self-corrected more than students who experienced self training.
Cholestatic hepatocellular injury: what do we know and how should we proceed.

Tissue injury and inflammation, repair, and fibrosis are fundamental components of acute and chronic cholestatic liver diseases, regardless of cause. Hepatocellular injury and death, with the accompanying inflammatory response, provoke symptoms of fatigue and weakness, and account, in part, for the characteristic cholestatic biochemical dysfunction that is characteristic of these liver diseases. The ensuing responses to cell injury can culminate in liver fibrosis, cirrhosis, portal hypertension, and chronic liver failure. Indeed, in the United States the cholestatic liver diseases primary sclerosing cholangitis and primary biliary cirrhosis account for 10% of all patients undergoing liver transplantation in 2003 (http://www.ustransplant.org/ srtr.php). Optimal therapy would address the mechanisms causing cholestasis and reverse the process. Unfortunately, such therapies do not currently exist, although agonists for the nuclear receptor FXR hold such promise [1,2]. Until such specific therapies exist, alternative therapeutic strategies would include approaches to reduce hepatocellular injury. Clarifying the cellular and molecular mechanisms underlying hepatocellular cytotoxicity in cholestasis would be helpful for designing and developing effective treatments for patients with cholestatic liver diseases. In this context, there is considerable experimental interest in the cellular mechanisms underlying hepatocellular injury during cholestasis. Common bile duct ligation (CBDL) with or without cholycystectomy in the mouse, or CBDL alone in the rat (which has no gall bladder) are popular models of cholestatic liver injury. However, like all models this approach has strengths and weaknesses. The strengths relate
Mass spectrometric fragmentations of hexafluoroacetone ketals derived from N‐alkenes

The mass spectrometric fragmentation behavior of the cyclic hexafluoroacetone ketals derived from eighteen n-alkenes is discussed with emphasis on locating the original olefinic bond. The major analytically useful fragments result from loss of CF3, loss of an alkyl side chain or loss of an aldehyde moiety from the ring. Influences of geometric isomerism on the spectra are examined by intensity ratios and ratios of competing fragmentations.
Predicting Properties from Scratch

Techwire Using the URL at the [end][1] of this item, readers can immediately offer feedback and suggestions on this topic. I t has always been a dream of materials researchers [[HN1][2]] to design a new material completely on paper, optimizing the composition and processing steps in order to
Construction load monitoring using instrumented shoring

Over the past 25 years in the United States there have been more than 85 collapses of structures under construction that have been directly attributable to formwork failure. Sensing systems and techniques applicable to the monitoring of construction site shoring and scaffolding are designed and implemented with preliminary systems being used in the field and in the laboratory. Such a sensor network can provide significant information about the load distribution on shoring systems. This information can allow dangerous situations to be quickly identified so that corrective action can be taken. Furthermore, the load data acquired with this system can be used to formulate improved construction codes that enhance construction work safety. Laboratory proof-of-concept experiments as well as actual field site measurements presenting the in-service use and capabilities of an intelligent shoring system are described in this paper.
Overview of biological response modifiers

The immune system is regulated by a variety of lymphokines, monokines, and colony-stimulating factors. Most have now been cloned and it is clear that these cytokines have a broad range of overlapping immunological, inflammatory, and physiological properties. Some of these cytokines might favorably influence the biological therapy of cancer and they have been collectively referred to by clinicians as "biological response modifiers." This review summarizes current knowledge about the molecular biology and biological properties of most of the common cytokines and provides a brief survey of their therapeutic potential in patients with cancer.
Characterization of a human colon/lung carcinoma oncogene

DNA sequences capable of inducing oncogenic transformation of NIH3T3 mouse cells are found in a number of human tumour cell lines. When DNAs of these cell lines are applied to monolayer cultures of the mouse fibroblasts, foci of transformed cells are observed 2-3 weeks later. DNA from cells of such primary foci can be used in turn to induce foci in a second cycle of gene transfer. The human DNA sequences responsible for transformation have been called oncogenes, the best characterized of which is closely related to the Harvey murine sarcoma virus oncogene. Here we present a characterization of an oncogene which we found originally to be present in DNA of the SW480 colon carcinoma cell line. We indicate its structural outlines and demonstrate, in extension of reported results, its presence in an activated form in the genome of several types of human tumour cell lines as well as in biopsy tissue from an adenocarcinoma of the large bowel. We identify this tumour oncogene with c-Ki-ras2, one of two known members of the Kirsten ras family of human proto-oncogenes, extending a series of recent reports which have demonstrated homologies between human oncogenes and those of Harvey and Kirsten murine sarcoma viruses. The c-Ki-ras2 oncogene of several tumour cell lines is shown to be amplified.
Isotope sinography: Technical modifications utilizing computer enhancement and the vertex view

Abstract The authors describe technical modifications in the noninvasive examination of the dural venous sinuses utilizing computer summation and enhancement of the venous-phase isotope angiogram, and a vertex view for outlining the anterior and midportion of the sagittal sinus.
Distinct generation, pharmacology, and distribution of sphingosine 1-phosphate and dihydrosphingosine 1-phosphate in human neural progenitor cells

In vivo and in vitro studies suggest a crucial role for Sphingosine 1-phosphate (S1P) and its receptors in the development of the nervous system. Dihydrosphingosine 1-phosphate (dhS1P), a reduced form of S1P, is an agonist at S1P receptors, but the pharmacology and physiology of dhS1P has not been widely studied. The mycotoxin fumonisin B1 (FB(1)) is a potent inhibitor of ceramide synthases and causes selective accumulation of dihydrosphingosine and dhS1P. Recent studies suggest that maternal exposure to FB(1) correlates with the development of neural tube defects (NTDs) in which the neural epithelial progenitor cell layers of the developing brain fail to fuse. We hypothesize that the altered balance of S1P and dhS1P in neural epithelial cells contributes to the developmental effects of FB(1). The goal of this work was first to define the effect of FB(1) exposure on levels of sphingosine and dh-sphingosine and their receptor-active 1-phosphate metabolites in human embryonic stem cell-derived neural epithelial progenitor (hES-NEP) cells; and second, to define the relative activity of dhS1P and S1P in hES-NEP cells. We found that dhS1P is a more potent stimulator of inhibition of cAMP and Smad phosphorylation than is S1P in neural progenitors, and this difference in apparent potency may be due, in part, to more persistent presence of extracellular dhS1P applied to human neural progenitors rather than a higher activity at S1P receptors. This study establishes hES-NEP cells as a useful human in vitro model system to study the mechanism of FB(1) toxicity and the molecular pharmacology of sphingolipid signaling. This article is part of a Special Issue entitled 'Post-Traumatic Stress Disorder'.
Performance evaluation of a lower limb exoskeleton for stair ascent and descent with Paraplegia

This paper describes the application of a powered lower limb exoskeleton to aid paraplegic individuals in stair ascent and descent. A brief description of the exoskeleton hardware is provided along with an explanation of the control methodology implemented to allow stair ascent and descent. Tests were performed with a paraplegic individual (T10 complete injury level) and data is presented from multiple trials, including the hip and knee joint torque and power required to perform this functionality. Joint torque and power requirements are summarized, including peak hip and knee joint torque requirements of 0.75 Nm/kg and 0.87 Nm/kg, respectively, and peak hip and knee joint power requirements of approximately 0.65 W/kg and 0.85 W/kg, respectively.
The management of combined oesophageal and duodenal atresia

Duodenal atresia (DA) in babies with oesophageal atresia (OA) is associated with significant morbidity and mortality. The management protocol for this combination of anomalies is not well defined and evolving. The aim of this study was to review our experience with combined OA and DA and to note the evolving trend in management at Sydney Children's Hospital. Over the last 30 years, 225 babies with OA have been treated at our institution. Ten babies had associated DA. A total of 19 anomalies were noted; one child had multiple lethal anomalies and received no treatment. In three babies the diagnosis of associated DA was missed initially. For the nine babies who were treated, four had a primary OA repair followed by a delayed DA repair; one had cervical oesophagostomy, gastrostomy and DA repair; and two had a simultaneous repair of OA and DA with a gastrostomy. The last two patients in this series have had a primary simultaneous repair of both anomalies without a gastrostomy. The complications noted in the nine patients treated included anastomotic strictures in five, recurrent tracheo-oesophageal fistula in one, food bolus obstruction in one, and a megaduodenum requiring tapering in one. We believe that adopting a management protocol of primary simultaneous repair of both anomalies without a gastrostomy is justified. There was no apparent increase in morbidity and mortality with such an approach.
Statics and kinetics of water vapor sorption of small loblolly pine samples

A better understanding of the sorption behavior of different wood structures could be useful in protecting wood against wood deterioration and fungal attack. The purpose of this study was to investigate the effect of differences among earlywood, latewood, and tree ring location within the stem cross-section of loblolly pine (Pinus taeda) on the sorption kinetics and statics of water vapor under ambient conditions. The water vapor sorption of earlywood and latewood in different tree rings was recorded using a dynamic contact angle analyzer under relative humidity changes from 11 to 89%, as provided by saturated salt solutions. Earlywood had higher sorption rates and diffusion coefficients than latewood, while outer tree rings had higher sorption rates and diffusion coefficients than inner tree rings. The sorption isotherms of earlywood, latewood, and different tree ring locations within the stem cross-section were fitted very well by a Hailwood–Horrobin model.
Relief of Extrinsic Pathway Inhibition by the Bid-dependent Mitochondrial Release of Smac in Fas-mediated Hepatocyte Apoptosis

The mitochondrial pathway is critical for the efficient execution of death receptor-initiated apoptosis in certain cell types. Questions remain as to why the mitochondria are required in that scenario. We investigated the molecular events that determined the need for the mitochondria by using an in vivo model of anti-Fas-induced hepatocyte apoptosis. In wild-type mice, Fas stimulation resulted in normal activation of caspase-3, with the generation of the active p19-p12 complex. Inbid-deficient mice, caspase-3 activation was arrested after the initial cleavage at Asp175. This allowed the generation of the p12 small subunit, but the p20 large subunit could not be further processed to the p19 subunit. The p20-p12 complex generated by Fas stimulation in bid-deficient hepatocytes was inactive, arresting the death program. Failure of p20/p12 caspase-3 to mature and to exhibit activity was because of the inhibition by the inhibitor-of-apoptosis proteins (IAPs), such as XIAP, and also to a low caspase-8 activity. This block could be overcome in wild-type mice by two mechanisms. Smac was released from mitochondria early following Fas activation and was competitively bound to the IAPs to reverse their effects. XIAP could also be cleaved, and this occurred later and was likely mediated by enhanced caspase activities. Both mechanisms were dependent on Bid and thus were not operative inbid-deficient hepatocytes. In conclusion, mitochondrial activation by Bid is required for reversing the IAP inhibition through Smac release. It is also required for the alternative activation of caspases through cytochrome c release, as demonstrated previously. Together, these events ensure a successful progression of the death program initiated by the death receptor activation in the hepatocyte.
Strong Ferromagnetic Exchange in 2-(4,5,6,7-Tetrafluorobenzimidazol-2-yl)-4,4,5,5- tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl

2-(4,5,6,7-Tetrafluorobenzimidazol-2-yl)-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-3-oxide-1-oxyl (F4BImNN) crystallizes to form hydrogen-bonded chains that are associated with nearby chains by π overlap between nitronylnitroxide groups, F/F, and F/π−C close contacts. F4BImNN exhibits strong ferromagnetic exchange interactions for an organic radical composed of first-row elements, with an exchange strength of J/k = (+)16−17 K for a ferromagnetic Heisenberg one-dimensional chain model.
Review of screening instruments for postpartum depression

This paper presents a review and discussion of eight self-report measures used to assess for depressive symptoms in the postpartum period. Because postpartum depression is a significant mental health problem, there is a need for reliable and valid screening instruments. Published psychometric data (e.g., reliability, sensitivity, specificity, positive predictive value, concurrent validity) of each self-report instrument are presented and critiqued. Results suggest that the Edinburgh Postnatal Depression Scale is the most extensively studied measure with postpartum women with moderate psychometric soundness. This review illustrates the need for more research in this area. Issues involved in the selection of measures are considered. Implications for clinical practice, research, culture and language are discussed.
Magical Realism in Libya

This essay argues that the writings of Libyan Ibrāhīm al-Kūnī, and particularly Nazīf al-hajar with its emphasis on animal-human juxtapositions and metamorphoses, should be considered examples of Arab magical realism. The circular narrative tells the story of a multi-generational struggle of a Touareg family with a legendary animal called a waddan. The last scion, he is taken on a trip to the border between the natural and the supernatural where he metamorphoses into the predator, the legendary animal and the history that both contain.
Missions and Medicine at Amherst: Family Ties to Edward Hitchcock Jr, the Missionary Movement, and the American University of Beirut

The Haystack Movement began at Williams College in 1805, occasioning the spread of American missions throughout the world. A half century later, two graduates of nearby Amherst College, Edward Hitchcock Jr and Daniel Bliss, laid the foundations for college health services in this country and for mission work and education in the Middle East. The influences of these two 19th century Amherst alumni are still felt today in our college health services and at the American University of Beirut.
Biomass, Productivity, and Nutrient Allocation in Subalpine Shrublands and Meadows of the Emerald Lake Basin, Sequoia National Park, California

Abstract The Emerald Lake Basin provides a long-term site for research on hydrology, ecology, and biogeochemistry, as well as baseline data for a representative subalpine watershed in the Sierra Nevada of California. Field studies provided quantitative data on the biomass, net primary production, and nutrient allocation of major subalpine shrub and meadow communities. Measurements carried out over two growing seasons found aboveground biomass per unit canopy area was 3857 g m-2 in Chrysolepis sempervirens, 3360 g m-2 in Salix orestera, and 1614 g m-2 in Phyllodoce breweri. The biomass for Chrysolepis and Salix canopies were high compared to other published data for subalpine and alpine shrublands, but the Phyllodoce biomass was comparable to values for ericaceous heath in the Rocky Mountains and European Alps. Wet and dry meadows had 377 and 98 g m-2, respectively, in aboveground living tissues, comparable to values from the Rocky Mountains and European Alps. Belowground biomass for shrub communities was ...
Optical Absorption Due to Excitation of Electrons Bound to Si and S in GaP

Infrared transmission measurements of GaP with S or Si donor impurities at liquid-helium temperature reveal absorption lines due to excitation of the donor electron. Strong absorption peaks corresponding to the $1s\ensuremath{\rightarrow}2{p}_{\ifmmode\pm\else\textpm\fi{}}$ transition are observed, and their spectral positions are used to determine optical ionization energies of 104.2 and 82.5 meV (\ifmmode\pm\else\textpm\fi{}0.3 meV), respectively, for S and Si donors in GaP. A fitting of Faulkner's effective-mass calculation for donor states to the observed levels yields the effective masses of the conduction band: ${m}_{\ensuremath{\perp}}=(0.191\ifmmode\pm\else\textpm\fi{}0.005){m}_{0}$ and ${m}_{\mathrm{II}}=(1.7\ifmmode\pm\else\textpm\fi{}0.2){m}_{0}$. The $p$-like final states observed in these measurements are found to differ significantly in binding energy from the excited donor-electron states observed in the "two-electron" recombination of the exciton bound to neutral sulfur in GaP.
The energetics of phase transitions in the system Na1+XZr2SiXP3-XO12, 1.9 ⩽ X ⩽ 2.5

Abstract The temperatures and enthalpies of phase transitions in the system Na 1 + X Zr 2 Si X P 3- X O 12 with 1.9 ⩽ X ⩽ 2.5, have been determined by differential scanning calorimetry. Second-order phase transitions were observed in all samples except for X = 2.5. The transition temperatures decreased systematically with X , varying from approximately 423 K for X = 1.9 to 375 K for X = 2.3. The enthalpies of transition followed a similar trend, 2.11 kJ mol −1 for X = 1.9 and 0.52 kJ mol −1 for X = 2.3.
Single fiber model of particle retention in an acoustically driven porous mesh.

A method for the capture of small particles (tens of microns in diameter) from a continuously flowing suspension has recently been reported. This technique relies on a standing acoustic wave resonating in a rectangular chamber filled with a high-porosity mesh. Particles are retained in this chamber via a complex interaction between the acoustic field and the porous mesh. Although the mesh has a pore size two orders of magnitude larger than the particle diameter, collection efficiencies of 90% have been measured. A mathematical model has been developed to understand the experimentally observed phenomena and to be able to predict filtration performance. By examining a small region (a single fiber) of the porous mesh, the model has duplicated several experimental events such as the focusing of particles near an element of the mesh and the levitation of particles within pores. The single-fiber analysis forms the basis of modeling the overall performance of the particle filtration system.
Carbon-Nanofiber-Reinforced Syntactic Foams: Compressive Properties and Strain Rate Sensitivity

The current study is focused on exploring the possibility of reinforcing syntactic foams with carbon nanofibers (CNFs). Syntactic foams are hollow, particle-filled composites that are widely used in marine structures and are now finding applications in other modes of transportation due to their high stiffness-to-weight ratio. The compressive properties of syntactic foams reinforced with CNFs are characterized over the strain rate range of 10−4 to 3,000 s−1, which covers seven orders of magnitude. The results show that despite lower density with respect to neat epoxy, CNF/syntactic foams can have up to 7.3% and 15.5% higher quasi-static compressive strength and modulus, respectively, for the compositions that were characterized in the current study. In addition, these properties can be tailored over a wide range by means of hollow particle wall thickness and volume fraction, and CNF volume fraction. The compressive strength of CNF/syntactic foams is also shown to generally increase by up to a factor of 3.41 with increasing strain rate when quasi-static and high-strain-rate testing data are compared. Extensive microscopy of the CNF/syntactic foams is conducted to understand the failure and energy absorption mechanisms. Crack bridging by CNFs is observed in the specimens, which can delay final failure and increase the energy absorption capacity of the specimens. Deformation of CNFs is also noticed in the material microstructure. The deformation and failure mechanisms of nanofibers are related to the test strain rate and the structure of CNFs.
A kinetic epoxidation assay for chloroperoxidase.

Chloroperoxidase exhibits a wide variety of enantioselective epoxidation reactions. Until now, the epoxidation activities have been mainly evaluated using elaborate gas chromatographic methods. This paper reports a rapid and convenient spectrophotometric assay for CPO. The disappearance of indene by catalytic epoxidation is monitored at 250 nm and this is used as an index of enzyme activity. This method will prove to be highly useful in large-scale screening of mutants.
Chronic ocular ischemia and neovascular glaucoma: A result of extracranial carotid artery disease*

Severe occlusive disease of the carotid artery may produce a rare syndrome of chronic ocular ischemia. Prolonged retinal hypoxia is associated with characteristic funduscopic changes and neovascularization of the iris, with subsequent obstruction of aqueous humor resorption. A case of neovascular glaucoma as a result of severe bilateral carotid occlusive disease and the pathophysiology involved are discussed. Definitive treatment consisted of carotid endarterectomy and aggressive control of intraocular pressure, including operative placement of a drainage implant in the anterior chamber of the eye. Seizure activity and an exacerbation of glaucoma developed after successful revascularization, exemplifying the derangements in cerebral and ocular function that may result from chronic hypoperfusion.
Oestrogen Modulates Cholecystokinin: Opioid Interactions in the Nervous System

Abstract: Responses of the nervous system to introceptive and extroceptive inputs depend upon the state of the brain. Oestrogen has the ability to modulate brain state and dramatically alter interactions among neural circuits to influence an organism's responses to given stimuli. Cholecystokinin (CCK) and endogenous opioid peptides (EOP) have a wide and parallel distribution in the nervous system. Their reciprocal interactions regulate a diverse physiology including reproduction, cortical function and nociception. The actions of CCK and EOP are diametrically opposed, in many regions. For example, when opioids inhibit reproductive behaviour or nociception, CCK facilitates. Because oestrogen is a powerful regulator of the expression of CCK and EOP, we examined whether oestrogen-state also modulated the interactions of these neuropeptides. In this paper we present new data and review previous work that demonstrates oestrogen modulation of functional CCK – opioid interactions that regulate reproductive behaviour, cortical function and nociception.
Electrochemical, spectral and kinetic characterization of the 5,8-dihydro compound formed on electrochemical reduction of 2-dimethylamino-3,6,7-trimethylpterin

Abstract 2-Dimethylamine-3,6,7-trimethylpterin gives rise to two voltammetric reduction peaks (IIc and IIIc) at the pyrolytic graphite electrode. Peak IIc is an almost reversible 2e − -2 H + reduction giving a 5,8-dihydro derivative. The latter is unstable and rearranges in a first order reaction to give the corresponding 7,8-dihydro compound. At pH ⩾ 6 the 5,8-dihydro intermediate may be observed by thin-layer spectroelectrochemistry and its spectrum and reaction kinetics studied. Peak IIIc is an irreversible 2e − -2 H + reaction of 2-dimethylamino-7,8-dihydro-3,6,7-trimethylpterin to give 2-dimethylamino-5,6,7,8-tetrahydro-3,6,7-trimethylpterin.
The thermal-hydraulics of aseptic food processing

Abstract The temperature profile for an N- component mixture of particles in a fluid flowing through a heated tube has been evaluated using a numerical method for the fluid and an analytical solution for the particles. The results for the time-at-temperature of the particles depend on the drift-flux parameters, which quantify the local slip. In particular, the more slip the better the heat transfer and the shorter the heat exchanger required for aseptic food processing. Two diagrams are given, which cover all parameters of interest for laminar flow.
Characterization of correlated line edge roughness of nanoscale line gratings using small angle x-ray scattering

To meet the challenges in dimensional metrology as the minimum feature size in semiconductor devices approaches sub-35 nm length scales, we have been developing a nondestructive method using x rays termed critical dimension small angle x-ray scattering (SAXS). Its capacity to quantify the dimension of linewidth, pitch, line height, and sidewall angle of line gratings has been demonstrated. In this work, we have further extended its capabilities to quantify the correlated line-edge roughness (LER) and linewidth roughness (LWR). Model line grating patterns with controlled LER and LWR were prepared and measured using x ray, their results were analyzed with model calculations. The magnitude of LER/LWR deduced from x-ray results compares favorably with the scanning electron microscopy results obtained from the same samples. An apparent Debye–Waller factor, which can be deduced from the SAXS data without any detailed model-based calculations, is found to be a convenient parameter to quantify the amplitude of LER/LWR.
The hydrogenation of α-methylstyrene by tricarbonyl(cyclopentadienyl)hydride compounds of tungsten and molybdenum; support for a radical mechanism

Abstract Rates of reaction of the hydrides of tungsten and molybdenum of the form HM(η 5 -C 5 H 5 (CO) 3 , with β-methylstyrene have been determined. The rate law is first order in olefin and in hydride. A mechanism involving a rate limiting step of hydrogen atom transfer to the olefin is consistent with the rate law, isotope effect and the absence of CO inhibition. The activation enthalpy for the reactions of HW(η 5 -C 5 H 5 )(CO) 3 and HMo(η 5 -C 5 H 5 )(CO) 3 are 97.5 ± 4.2 and 89.1 ± 3.3 kJ/mol, respectively. The rate constant for the reaction of styrene and HW(β 5 -C 5 H 5 )(CO) 3 is approximately that of β-methylstyrene, while β-methylstyrene was not observed to react under the conditions of the previous determinations. This suggests that attack by the hydride occurs at the β-carbon and this process is inhibited by substituents at that location.
Evidence for observation of virtual radio Cherenkov fields

Abstract We present evidence for observation of virtual electromagnetic fields in the radio domain from experiment T926 at the Fermilab Meson Test Beam Facility. Relativistic protons with 120 GeV energy traversed a sealed electromagnetic cavity and were observed in the radio regime of 200 MHz–GHz. Closely related to ordinary Cherenkov radiation, which we also measured, the virtual fields require no acceleration for their existence. The experiment is also the first observation of fields from hadronic showers, an independent and new confirmation of coherent radio emission from ultra-relativistic particles. Conditions of very low signal-to-noise were overcome by a novel and unbiased filtering strategy that exploits exhaustive studies of correlations in the noise backgrounds. Linear scaling of the signal region with the number of beam particles provides evidence of coherence. Extrapolation to measurement of the field of a single relativistic proton charge is consistent within errors. Our study also illustrates new data processing methods that may be applied broadly in conditions of extremely low signal-to-noise.
The 308 nm laser photodissociation of HN3 adsorbed on Si(111)-7 × 7

Abstract The photodissociation of HN 3 adsorbed on Si(111)-7 × 7 at 308 nm was investigated using HREELS and XPS. Species such as NH x , N 2 , and N 3 , were identified on the surface with comparable concentrations after the irradiation with 1 × 10 20 photons of a 10 L HN 3 dosed Si(111) surface. The N 3 species showed two stretching modes at 178 and 255 meV, while that of the N 2 appeared at 206 me V in HREELS. The formation of these products was also corroborated by the corresponding XPS results. Further laser irradiation caused the dissociation and partial desorption of the adsorbates with NH x left on the surface. Annealing the post-irradiated sample to 500 and 800 K resulted in the breaking of the NH bond and the desorption of the H-species, while the atomic N remained on the surface forming silicon nitride. The possibility of using HN 3 for laser-induced chemical vapor deposition of Si 3 N 4 and group-III nitrides at low temperatures is suggested.
Effect of herbage depletion on short-term foraging dynamics and diet quality of steers grazing wheat pastures.

Two complementary experiments were completed to assess short-term foraging dynamics, diet quality, and ruminal degradation kinetics of herbage consumed by steers with 3 levels of herbage depletion. Experiment 1 was a behavioral study in which 2 ruminally cannulated steers were allocated to grazing scenarios simulating 3 levels of herbage depletion. These treatments included an ungrazed sward (control), as well as medium and high levels of herbage depletion. Grazing scenarios were sampled for sward surface height and amount of green leaf and stem before being grazed. Foraging dynamics were determined through measurements of bite rate, bite depth, eating step rate, eating distance, potential area consumed while grazing, and bites and intake per eating step. Also, quality of potential herbage consumed was estimated from hand-plucked herbage. In Exp. 2, ruminal degradation kinetics of DM for samples of herbage consumed (masticate) by steers during Exp. 1 were assessed in situ using 5 ruminally cannulated steers. The immediately soluble, degraded, and undegraded DM fractions were determined. The DM disappearance rate and lag times were determined from a nonlinear regression model, and the effective degradability of DM was calculated. Herbage depletion resulted in increased eating steps/minute, as well as the potential area harvested while grazing (P 0.05). Under these experimental conditions, steers adapted their foraging dynamic and were able to sustain diet quality in the short term. These results imply that behavioral adaptations would make diet quality less sensitive to certain levels of herbage depletion.
Prevention of a vitamin deficiency by provision of the product synthesized by the coenzyme which contains the vitamin.

SINCE the early work of Evans and Lepkovsky1 it has been recognized that a high-fat diet has a sparing action on thiamine. Jones2 demonstrated that the deleterious effects of oxythiamine, an inhibitor of thiamine (vitamin B1, could be essentially counteracted by a high-fat diet. We thought it would be interesting to see what changes, if any, take place in the activity of two of the enzyme systems requiring thiamine pyrophosphate—pyruvate dehydrogenase and transketolase, a key enzyme of the pentose cycle—when oxythiamine is administered to rats on a high-fat diet.
An evaluation of freshman engineering persistence using Expectancy-Value Theory

As we engage in an increasingly complex and quickly progressing world, the development of science, technology, engineering, and mathematics (STEM) students will be increasingly important to the continuation of the United States' competitiveness. However, the overall number of STEM students earning a degree will not be able to meet the increasing demand for practicing professionals especially within historically underrepresented groups such as women and minorities. One way to tackle this problem is to increase the retention of STEM students by studying the processes that influence persistence to completion of a STEM degree. Retention is critically important to the field of engineering as over 10% of all engineering majors will switch to other STEM degrees and even more will not persist within STEM fields at all. The focus of this paper is to utilize Expectancy-Value Theory to determine how freshman engineering students (both those who persisted within the major and those who switched out of the major) perceive engineering. Research was conducted at a predominately undergraduate liberal arts institution with a medium sized engineering program. Interview data was examined for 11 entering freshman who stayed with the engineering program (persisters) and 10 entering freshman who switched to different majors (switchers).
Kinematic Evaluation of Association between Disc Bulge Migration, Lumbar Segmental Mobility, and Disc Degeneration in the Lumbar Spine Using Positional Magnetic Resonance Imaging:

Degenerative disc disease and disc bulge in the lumbar spine are common sources of lower back pain. Little is known regarding disc bulge migration and lumbar segmental mobility as the lumbar spine moves from flexion to extension. In this study, 329 symptomatic (low back pain with or without neurological symptoms) patients with an average age of 43.5 years with varying degrees of disc degeneration were examined to characterize the kinematics of the lumbar intervertebral discs through flexion, neutral, and extension weight-bearing positions. In this population, disc bulge migration associated with dynamic motion of the lumbar spine significantly increased with increased grade of disk degeneration. Although no obvious trends relating the migration of disc bulge and angular segmental mobility were seen, translational segmental mobility tended to increase with disc bulge migration in all of the degenerative disc states. It appears that many factors, both static (intervertebral disc degeneration or disc height) and dynamic (lumbar segmental mobility), affect the mechanisms of lumbar disc bulge migration.
Spiral CT scanning technique in the detection of aspiration of LEGO foreign bodies.

Background: . Radiolucent foreign bodies (FBs) such as plastic objects and toys remain difficult to identify on conventional radiographs of the neck and chest. Children may present with a variety of respiratory complaints, which may or may not be due to a FB.
PURE D-WAVE PAIRING SYMMETRY IN HIGH-TC CUPRATE SUPERCONDUCTORS

Abstract We have directly observed the half-integer flux quantum effect in controlled-orientation tricrystal Bi 2 Sr 2 CaCu 2 O 8+ x (Bi2212) and tetracrystal Tl 2 Ba 2 CuO 6+ δ (Tl2201) by using a high-resolution scanning SQUID microscope. The results of these phase-sensitive pairing symmetry tests, along with the recent ARPES data for Bi2212 by Ding et al., have definitively established the existence of pure d x 2 – y 2 -wave pairing symmetry in both Bi2212 and Tl2201.
L1 asymptotic behavior of compressible, isentropic, viscous 1-D flow

We study the large time behavior in L1 of the compressible, isentropic, viscous 1-D flow. Under the assumption that the initial data are smooth and small, we show that the solutions are approximated by the solutions of a parabolic system, and in turn by diffusion waves, which are solutions of Burgers equations. Decay rates in L1 are obtained. Our method is based on the study of pointwise properties in the physical space of the fundamental solution to the linearized system. © 1994 John Wiley & Sons, Inc.
Modelos animales en psicopatología experimental: miedo, tolerancia a las drogas y condicionamiento

The Darwinian idea of continuity of the species has justified the research with non-human animals to understand humans. If humans are evolutionarily connected with the rest of the animals, then we can find on them analogous models to study our biology and behavior. In psychology, animal models have demonstrated to be an effective tool for understanding normal and abnormal behaviors. In the present article some examples of animal models in experimental psychopathology are presented, and two illustrative studies of how this type of research can be informative about the etiology, maintenance, and treatment of behavioral disorders are reported.