cssi/SciSciGPT-SciSciNet huggingface dataset:
Morphometry of otoconia in the utricle and saccule of developing Japanese quail.

The development of otoconia in the utricular and saccular maculae from initial embryonic formation to adult stages was examined in Japanese quails. Both the morphology and size of the otoconia were quantified at different developmental stages. It was observed that the otoconia were initially formed on embryologic stage E5 in the saccule and E6 in the utricle. Otolith mass areas increased in a sigmoidal growth pattern, with saccular otolith areas being smaller than the utricular mass areas. Saccular otolith masses reached adult values at embryonic stage E12 and utricular areas reached adult values at post-hatch day 7. Mature individual otoconia were characterized by a barrel shape with two trihedral faceted ends. However, initial formation of otoconia at E5 (saccular) and E6 (utricular) maculae was characterized by a double fluted morphology that consisted of an hourglass shape with extended fins forming trihedral angles of 120°. Double fluted otoconia rapidly filled, so that by embryonic day 8 mature otoconia dominated the maculae for the remainder of development through adulthood. Thus, a progression from double fluted to mature forms was noted. Mature utricular otoconia in adult quails averaged 11 μm in length and 5 μm in width, with length/width ratios of approximately 2.5:1, for all size ranges. Saccular otoconia were smaller, having about 70% the size of utricular otoconia in both length and width. During development, the average size and range of individual otoconia increased nearly linearly for both otolith organs. In the utricular macula, large otoconia were concentrated in the lateral regions of the epithelium. In contrast, otoconia of various sizes were distributed uniformly across the surface of the saccular macula.
Studies of central nervous system disorders with single photon emission computed tomography and positron emission tomography: Evolution over the past 2 decades

Single photon emission computed tomography (SPECT) was introduced in the 1960s to detect breakdowns in the blood-brain barrier and was replaced by x-ray computed tomography in the mid-1970s. The development of the deoxyglucose (DG) technique to measure regional cerebral glucose metabolism by employing either autoradiography, using 14 CDG, or positron emisison tomography (PET), using 18 FDG, added a major dimension to the investigation of brain function. In the late 1970s and early 1980s, the FDGPET technique was widely used to examine a variety of neuropsychiatric disorders. It soon became apparent that functional imaging was more sensitive than anatomic imaging in detecting abnormalities of the brain related to aging, dementia, tumors, seizures, cerebral vascular accidents, and psychiatric problems. Because of its complexity and the cost involved, PET was used in a limited number of centers in the United States. However, the successes of PET resulted in the resurgence of interest in SPECT as an alternative technology after almost a decade. This became possible because of the synthesis of iodine 123-and technetium 99m-labeled radiopharmaceuticals to determine regional cerebral blood flow. Since blood flow and metabolism are coupled in most pathological states, patterns of abnormality noted on SPECT were similar to those seen on PET in many disorders. Since the introduction of high resolution SPECT imaging instruments, the role of SPECT has been further enhanced. The successful synthesis of both positron and single emitting radioligands to image dopamine and other receptors has started a new era in neurosciences and will have a far-reaching impact on the day-to-day practice of neuropsychiatry.
Effect of azathioprine in patients with lupus glomerulonephritis

Recent studies have shown that the course of lupus glomerulonephritis is usually one of inexorable progression to renal failure despite intensive treatment with glucosteroids. Seventeen patients were treated with low doses of prednisone (<20 mg/day) and azathioprine (2–3 mg/kg/day) for 6 to 36 months. Diagnosis of the renal lesion, by biopsy, included lupus glomerulitis (1), moderately severe glomerulonephritis (4) and severe glomerulonephritis (12). Seven cases with severe nephritis had the nephrotic syndrome and 9/17 were less than age 16 at onset. In one patient proteinuria increased after 24 months of therapy and another with severe renal failure at onset failed to respond. In the remaining 15 cases GFR either returned to normal (3) or remained normal (12). There was a significant reduction in proteinuria in every case, including a remission in 6 patients with the nephrotic syndrome. There was no evidence of progression of the renal lesion, by biopsy, in 9 patients reexamined, including the patient with uremia at onset. In 8 a striking decrease in severity was found, characterized by a relative absence of proliferation and reduction in deposition of electron-dense material. After 24 to 36 months of treatment in 5 patients with severe glomerulonephritis initially there were prominent membranous changes, by electronmicroscopy, which were indistinguishable from membranous nephropathy. This study demonstrates improvement in clinical and histological features of lupus glomerulonephritis with azathioprine-prednisone therapy. In addition, following suppression of the active proliferative lesion a new finding of membranous transformation was found.
Test-Retest Reliability of the General Ability Measure for Adults

The test stability for the General Ability Measure for Adults was examined for up to a 48-day interval (M = 35 days, SD = 5) for a sample of 52 college students, ages 19 to 51 years. The means for the Intelligence Quotient were 107 (SD = 11) and 115 (SD = 11), with a test-retest Pearson correlation of .62. Stability estimates for the measure's subtests were .30 for Matching, .33 for Analogies, .54 for Sequences, and .40 for Construction. Reliability coefficients were lower than expected for Matching, Analogies, and Sequences subtests and much lower than those reported in the test manual. The mean scores increased significantly on retest. Over-all, this study supported the limited temporal stability of the General Ability Measure for Adults.
The effects of irradiance on nitrate uptake and dissolved organic nitrogen release by phytoplankton in the Ross Sea

Abstract The effects of irradiance on nitrate uptake and subsequent dissolved organic nitrogen (DON) release were investigated using laboratory cultures of Phaeocystis sp. and phytoplankton assemblages dominated by Phaeocystis antarctica in the Ross Sea during cruises in November–December, 1994 and December 1995–January, 1996. 15N-labeled nitrate was used to determine nitrate uptake rates, and an ion retardation column (IRC) method was used to determine 15N-DON release rates (both the total as well as the low molecular weight (LMW) fraction). Nitrate uptake was strongly dependent on irradiance. The maximum specific nitrate uptake rate achieved by Phaeocystis cultures in short (
Correlated random walks with stay

A random walk describes the movement of a particle in discrete time, with the direction and the distance traversed in one step being governed by a probability distribution. In a correlated random walk (CRW) the movement follows a Markov chain and induces correlation in the state of the walk at various epochs. Then, the walk can be modelled as a bivariate Markov chain with the location of the particle and the direction of movement as the two variables. In such random walks, normally, the particle is not allowed to stay at one location from one step to the next. In this paper we derive explicit results for the following characteristics of the CRW when it is allowed to stay at the same location, directly from its transition probability matrix: (i) equilibrium solution and the fast passage probabilities for the CRW restricted on one side, and (ii) equilibrium solution and first passage characteristics for the CRW restricted on bath sides (i.e., with finite state space).
Pleiotropic effects of 3-hydroxy-3-methylglutaryl coenzyme a reductase inhibitors on renal function

Pleiotropic, or non-lipid-dependent, effects mediated by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (statins) have important clinical implications for the cardiovascular (CV) system. Atherosclerosis is an inflammatory process accompanied by increases in levels of plasma inflammatory markers and accumulation of immune cells within atherosclerotic plaques. Statins not only decrease serum lipid levels, but also inhibit signaling molecules at several points in inflammatory pathways. The anti-inflammatory effects and improved endothelial function associated with statin therapy are thought to be partly responsible for the reduction in CV morbidity and mortality. In analogy, patients with chronic kidney disease administered statins for CV risk reduction show evidence of improved renal function. However, whether statins confer similar protective benefits on the kidney has not been established. Several lines of evidence suggest that similar etiologic and pathological processes may be involved in CV and chronic kidney diseases. If inflammation and functional changes in the renovascular endothelium contribute to the progression of kidney disease, statins are likely to be effective in the treatment of renal disease. In this review, we critically consider emerging data indicating that statins may modulate renal function by altering the inflammatory response of the kidney and renal vasculature to dyslipidemia. Whether the amelioration of renal function by statins is separable from the lipid-lowering effects of these drugs still remains to be delineated. Other questions that remain to be addressed and issues that should be investigated also are presented.
Near-Threshold Computing: Reclaiming Moore's Law Through Energy Efficient Integrated Circuits

Power has become the primary design constraint for chip designers today. While Moore's law continues to provide additional transistors, power budgets have begun to prohibit those devices from actually being used. To reduce energy consumption, voltage scaling techniques have proved a popular technique with subthreshold design representing the endpoint of voltage scaling. Although it is extremely energy efficient, subthreshold design has been relegated to niche markets due to its major performance penalties. This paper defines and explores near-threshold computing (NTC), a design space where the supply voltage is approximately equal to the threshold voltage of the transistors. This region retains much of the energy savings of subthreshold operation with more favorable performance and variability characteristics. This makes it applicable to a broad range of power-constrained computing segments from sensors to high performance servers. This paper explores the barriers to the widespread adoption of NTC and describes current work aimed at overcoming these obstacles.
Artifact or Meaningful Theoretical Constructs?: Examining Evidence for Nonbelief- and Belief-Based Attitude Change Processes

Fishbein and Middlestadt (1995) argued that evidence for nonbelief-based attitude change is primarily artifactual, resulting from inadequate one, belief-based measurement of attitudes and beliefs. Thus, all attitude change occurs through this process. In this article, we present three arguments in response. First, evidence exists suggesting that some attitude change processes are best conceptualized as relatively nonbelief based. Second, evidence is presented of attitudes resulting from relatively nonbelief- and belief-based attitude change processes, as assessed by the same measure of beliefs within the same study. Third, studies have found substantive and meaningful differences in the attitudes resulting from what are posited to be different attitude change processes. Together, these arguments provide a strong case for the existence and differential consequences of both belief- and nonbelief-based attitude change processes.
Comparative hematology: Studies on cats including one with factor XII (hageman) deficiency

Abstract 1. 1. Cat plasma prothrombin and partial thromboplastin times are faster than human. Thromboplastin generation tests are very similar. 2. 2. Factors VIII and V assay 24 and 13 times the human standard. Cat factors VII, X. IX, XI and XII assayed at 2.5 to 4 times human. Factors I, II and XIII fell within the human range and Fletcher was extremely low. 3. 3. One cat lacked factor XII and showed a prolonged APTT and clotting time. 4. 4. Cat profibrinolysin was activated by streptokinase but not by urokinase. 5. 5. Cat platelets aggregated with the usual human aggregation agents with the exception of thrombin and ristocetin. 6. 6. Cat erythrocytes were smaller and more numerous than human. 7. 7. Leukocyte counts were quite variable. 8. 8. Serum protein electrophoretic patterns differed from human in the greater migration of albumin and the presence of numerous unidentified bands. 9. 9. Biochemical tests showed high sodium and chloride values.
Ventricular defibrillation using biphasic waveforms: The importance of phasic duration

Biphasic waveforms can be used to defibrillate the heart with less energy than that used by monophasic waveforms. In 14 anesthetized open chest dogs with large contoured defibrillation electrodes, the effect on defibrillation efficacy of varying the duration of the two phases of biphasic waveforms was studied. All combinations of 0, 1, 3.5, 6 and 8.5 ms duration were used for both the first and the second phase except for the meaningless case in which both durations were 0 ms. The 3.5-2 waveform (3.5 ms first phase and 2 ms second phase) was also tested. All the hearts were defibrillated with less than or equal to 5 joules using any of the 25 waveforms. However, biphasic waveforms with the second phase shorter than or equal to the first had significantly lower defibrillation thresholds than did those with the second phase longer than the first or than did monophasic waveforms of approximately the same total duration. A plot of defibrillation threshold current strength versus second phase duration for all biphasic waveforms with a 3.5 ms first phase did not produce a hyperbolic strength-duration curve as seen with monophasic waveforms. To verify these findings, defibrillation dose-response curves were obtained for the 3.5-2, 6-6 and 3.5-8.5 biphasic waveforms in another six dogs. The 50 and 80% successful voltage doses of the 3.5-8.5 waveforms were significantly higher than those of the other two waveforms, which were not different from one another.(ABSTRACT TRUNCATED AT 250 WORDS)
Localization of angiotensin II receptor subtypes in the rabbit adrenal and kidney

The localization of subtypes of the angiotensin II receptor has been determined by autoradiographic techniques using iodinated angiotensin II and two nonpeptide antagonists that exhibit selective affinities. DuP 753 specifically displaces type 1 sites (AII-1) and PD123177 inhibits only type 2 sites (AII-2). The rabbit adrenal cortex contains predominately AII-1 sites and the few AII-2 sites that are present are nonuniformly distributed. In the rabbit kidney, the fibrous outer sheath contains exclusively AII-2 sites whereas the glomeruli of the renal cortex and the renal medulla exhibit only AII-1 sites.
Corporate Codes of Conduct and the Value of Autonomy

In this paper, I will explore what may ethically be included in an explicitly adopted code of conduct for a corporation. I shall first demonstrate that these codes are tightly constrained by the correct theory of corporate social responsibility. Milton Friedman's theory, which correctly takes autonomy as a central value, is especially restrictive. I shall argue, though, that if we adopt a theory which more fully recog nizes the value of autonomy then we can recognize a broader, but not unlimited range of what might be included in a corporate code of conduct. It will be helpful to have an example at hand, so I shall list a few clauses of the Levi Strauss & Co. Global Sourcing and Operating Guidelines:
Substrate-selectivity in acylhydrolases: a cautionary tale

Recent surge in interest in the chemistry and biology of various lipids and related compounds intensified efforts aimed at structural and functional characterization of diverse enzymes, which hydrolyze and modify these compounds. Most of these enzymes were identified in assays using specific substrates, often in search of an industrially useful activity. The enzymes became therefore known for the chemistry they catalyze in vitro, often without detailed knowledge of the biologically relevant chemistry in which the protein is involved. However, the physiology of these enzymes is much more complex and may involve yet unidentified substrates and signaling pathways. In this short paper, I discuss three such cases, where in spite of detailed structural knowledge of the enzymes, their true biological function is far from clear. The examples include platelet-activating factor acetylhydrolases, acyl protein thioesterase I and peroxisomal medium-length chain thioesterases.
Advantages and distinguishing features of focus point supersymmetry

Diverse experimental constraints now motivate models of supersymmetry breaking in which some superpartners have masses well above the weak scale. Three alternatives are focus point supersymmetry and inverted hierarchy models, which embody a naturalness constraint, and the more recent framework of split supersymmetry, which relaxes that constraint. Many aspects of their phenomenology are very similar. They can be distinguished, however, through detailed study of superoblique parameters, the Higgs potential and other observables.
Hybrid multi-scale composites developed from glass microfiber fabrics and nano-epoxy resins containing electrospun glass nanofibers

Abstract In this study, hybrid multi-scale composites were developed from glass microfiber fabrics (GFs) and nano-epoxy resins containing electrospun glass nanofibers (EGNFs). The hypothesis was that, through dispersing a small amount of EGNFs into epoxy resin, mechanical properties (particularly out-of-plane mechanical properties) of the resulting hybrid multi-scale composites would be significantly improved. The composites were fabricated by the technique of vacuum assisted resin transfer molding (VARTM). The interlaminar shear strength, flexural properties, impact absorption energy, and tensile properties of the composites were evaluated, and the results were compared to those acquired from GFs/epoxy composite as well as GFs/epoxy composites containing chopped glass microfibers (GMFs); additionally, the reinforcement and/or toughening mechanisms were investigated. The study revealed that the nano-epoxy resin with 0.25 wt.% of EGNFs resulted in substantial improvements on mechanical properties of the resulting hybrid multi-scale composites.
Effective interaction for relativistic mean-field theories of nuclear structure

We construct an effective interaction, which when treated in a relativistic Hartree-Fock approximation, reproduces rather accurately the nucleon self-energy in nuclear matter and the Migdal parameters obtained via relativistic Brueckner-Hartree-Fock calculations. This effective interaction is constructed by adding Born terms, describing the exchange of pseudoparticles, to the Born terms of the Dirac-Hartree-Fock analysis. The pseudoparticles have relatively large masses and either real or imaginary coupling constants. (For example, exchange of a pseudo-sigma with an imaginary coupling constant has the effect of reducing the scalar attraction arising from sigma exchange while exchange of a pseudo-omega with an imaginary coupling constant has the effect of reducing the repulsion arising from omega exchange. The terms beyond the Born term in the case of pion exchange are well simulated by pseudo-sigma exchange with a real coupling constant.) The effective interaction constructed here may be used for calculations of the properties of finite nuclei in a relativistic Hartree-Fock approximation.
Solution Structure of 3-Oxo-Δ5-Steroid Isomerase

The three-dimensional structure of the enzyme 3-oxo-Δ5-steroid isomerase (E.C. 5.3.3.1), a 28-kilodalton symmetrical dimer, was solved by multidimensional heteronuclear magnetic resonance spectroscopy. The two independently folded monomers pack together by means of extensive hydrophobic and electrostatic interactions. Each monomer comprises three α helices and a six-strand mixed β-pleated sheet arranged to form a deep hydrophobic cavity. Catalytically important residues Tyr14(general acid) and Asp38 (general base) are located near the bottom of the cavity and positioned as expected from mechanistic hypotheses. An unexpected acid group (Asp99) is also located in the active site adjacent to Tyr14, and kinetic and binding studies of the Asp99 to Ala mutant demonstrate that Asp99 contributes to catalysis by stabilizing the intermediate.
Mutations in the MotA protein of Escherichia coli reveal domains critical for proton conduction

The MotA protein of Escherichia coli is an essential component of the torque-generating units that drive the flagellar rotary motor. A variety of evidence indicates that MotA is involved in transmembrane proton conduction. We have now mapped a number of MotA mutants, focusing primarily on those previously shown to be dominant. Fifty-six mutations (all dominant), each causing severe or complete impairment of function, were sequenced and found to correspond to 31 different alleles. All except two of these encoded amino acid substitutions clustered in four hydrophobic, presumably membrane-spanning segments, that together make up only one-third of the length of the polypeptide chain. In contrast, eight mutations (5 dominant), each causing only slight impairment of function (slow alleles), were sequenced and found to specify amino acid substitutions in three hydrophilic domains. The clustering of the mutations provides independent support for the suggestion that MotA is a transmembrane proton channel and places significant constraints on models for the molecular mechanism of ion conduction.
Infragravity waves in the deep ocean: Generation, propagation, and seismic hum excitation

[1] Oceanic infragravity waves are investigated as a possible source of seismic free oscillations, often referred to as the “hum” of the Earth, using a numerical model of depth-independent, nondispersive, long-wave dynamics with a forcing from nonlinear interactions among the primary wind waves (including swell). Because of near-resonant amplification, the structure of the primary-wave forcing field in shallow water, and an edge-trapping mechanism, infragravity waves are excited very effectively near the coasts. Deep-water infragravity waves are significantly influenced both by offshore leakage and propagation of the coastally generated free waves and by deep-water primary-wave forcing. With the inclusion of “mesoscale” variability on top of the more slowly varying primary waves generated in synoptic storms, the deep-water infragravity waves are found to have an amplitude on the order of a millimeter in height, which is consistent with field observations and considered to be sufficient to account for local hum excitation in the middle of the basin.
Endovascular aortic grafting: current status

Abstract Endovascular repair of abdominal aortic aneurysms was first reported in 1991. Since then there has been widespread development of many stent-grafts for abdominal aortic aneurysm repair. Available data support the proposition that stent-grafts are generally safe, although their long-term efficacy remains completely unknown. Importantly, endovascular abdominal aortic aneurysm repair to date does not have fewer complications nor lower mortality rates than open repair; in fact, the opposite appears true. Along with most new techniques come new complications, and endovascular repair of abdominal aortic aneurysm has brought forth the concepts of both `endoleak' and device failure. While uncommon, delayed abdominal aortic aneurysm rupture following seemingly successful endovascular repair of abdominal aortic aneurysm has been reported. In our opinion, these faults, unique to endovascular repair, mandate a cautious approach to the clinical application of stent-grafts. Until ongoing Phase 2 and future Phase 3 studies are completed with a minimum of 2–3 years follow-up, we will not know if endovascular repair of abdominal aortic aneurysm represents a giant step forward or merely an industry-driven overuse of proprietary technology.
TRP Channel Regulates EGFR Signaling in Hair Morphogenesis and Skin Barrier Formation

A plethora of growth factors regulate keratinocyte proliferation and differentiation that control hair morphogenesis and skin barrier formation. Wavy hair phenotypes in mice result from naturally occurring loss-of-function mutations in the genes for TGF-alpha and EGFR. Conversely, excessive activities of TGF-alpha/EGFR result in hairless phenotypes and skin cancers. Unexpectedly, we found that mice lacking the Trpv3 gene also exhibit wavy hair coat and curly whiskers. Here we show that keratinocyte TRPV3, a member of the transient receptor potential (TRP) family of Ca(2+)-permeant channels, forms a signaling complex with TGF-alpha/EGFR. Activation of EGFR leads to increased TRPV3 channel activity, which in turn stimulates TGF-alpha release. TRPV3 is also required for the formation of the skin barrier by regulating the activities of transglutaminases, a family of Ca(2+)-dependent crosslinking enzymes essential for keratinocyte cornification. Our results show that a TRP channel plays a role in regulating growth factor signaling by direct complex formation.
Molecular and biological roles of Ape1 protein in mammalian base excision repair

Many oxidative DNA lesions are handled well by base excision repair (BER), but some types may be problematic. Recent work indicates that 2-deoxyribonolactone (dL) is such a lesion by forming stable, covalent cross-links between the abasic residue and DNA repair proteins with lyase activity. In the case of DNA polymerase beta, the reaction is potentiated by incision of dL by Ape1, the major mammalian AP endonuclease. When repair is prevented, polymerase beta is the most reactive cross-linking protein in whole-cell extracts. Cross-linking with dL is largely avoided by processing the damage through the "long-patch" (multinucleotide) BER pathway. However, if excess damage leads to the accumulation of unrepaired oxidative lesions in DNA, there may be a danger of polymerase beta-mediated cross-link formation. Understanding how cells respond to such complex damage is an important issue. In addition to its role in defending against DNA damage caused by exogenous agents, Ape1 protein is essential for coping with the endogenous DNA damage in human cells grown in culture. Suppression of Ape1 using RNA-interference technology causes arrest of cell proliferation and activation of apoptosis in various cell types, correlated with the accumulation of unrepaired abasic DNA damage. Notably, all these effects are reversed by expression of the unrelated protein Apn1 of S. cerevisiae, which shares only the enzymatic repair function with Ape1 (AP endonuclease).
Disparate Locations of the 52- and 60-kDa Ro/SS-A Antigens in Cultured Human Keratinocytes

Anti–52- and anti–60-kDa Ro/SS-A (Ro) autoantibodies are produced by most patients with subacute cutaneous lupus erythematosus and neonatal lupus erythematosus and are thought to be pathogenic in these two disorders. To learn more about the epidermal antigens targeted by Ro autoantibodies, a panel of anti-52 and anti–60-kDa Ro antibodies was purified from human autoimmune sera and rabbit anti-sera and then used to: (i) determine the expression and location of the Ro antigens in human keratinocytes; (ii) clarify discrepancies in previous localization studies; and (iii) verify the existence of Ro autoantibodies that cross-react with the 52- and 60-kDa Ro antigens, as previously reported. By immunoblot analysis these antibodies demonstrate that 52- and 60-kDa Ro proteins are expressed in normal human skin and cultured keratinocytes. By indirect immunofluorescence studies with cultured human cells, tile anti–52-kDa Ro antibodies produce fine granular cytoplasmic fluorescence and less intense nuclear fluorescence, with apparent nucleolar sparing. The anti–60-kDa Ro autoantibodies produce weak cytoplasmic fluorescence and intense coarse granular nuclear fluorescence with apparent nucleolar sparing. We found distinct differences in the intracellular localization of the 52- and 60-kDa Ro autoantigens. This difference suggests that the 52- and 60-kDa Ro antigens may have independent cellular functions. Finding 60-kDa Ro antigen predominantly in the nucleus challenges the notion that the majority of the intracellular 60-kDa Ro antigen is complexed with the cytoplasmic mRNA. Additionally, our failure to find a cross-reactive epitope on these two proteins indicates that the 52-kDa Ro antigen is probably a true immunogen and not merely a protein that cross-reacts with anti–60-kDa Ro autoantibodies, as others have suggested.
Cytoskeletal changes during neurogenesis in cultures of avian neural crest cells

Neural crest cells are motile and mitotic, whereas their neuronal derivatives are terminally post-mitotic and consist of stationary cell body from which processes grow. The present study documents changes in the cytoskeleton that occur during neurogenesis in cultures of avian neural crest cells. The undifferentiated neural crest cells contain dense bundles of actin filaments throughout their cytoplasm, and a splayed array of microtubules attached to the centrosome. In newly differentiating neurons, the actin bundles are disrupted and most of the remaining actin filaments are reorganized into a cortical layer underlying the plasma membrane of the cell body and processes. Microtubules are more abundant in newly-differentiating neurons than in the undifferentiated cells, and individual microtubules can be seen dissociated from the centrosome. Neuron-specific β-III tubulin appears in some crest cells prior to cessation of motility and cell division, and expression increases with total microtubule levels during neurogenesis. To investigate how these early cytoskeletal changes might contribute to alterations in morphology during neurogenesis, we have disrupted the cytoskeleton with pharmacologic agents. Microfilament disruption by cytochalasin immediately arrests the movement of neural crest cells and causes them to round-up, but does not significantly change the morphology of the immature neurons. Microtubule depolymerization by nocodazole slows the movement of undifferentiated cells and causes retraction of processes extended by the immature neurons. These results suggest that changes in the actin and microtubule arrays within neural crest cells govern distinct aspects of their morphogenesis into neurons.
Closure spaces and characterizations of filters in terms of their stone images

Frechet, strongly Frechet, productively Frechet, weakly bisequential and bisequential filters (i.e., neighborhood filters in spaces of the same name) are characterized in a unified manner in terms of their images in the Stone space of ultrafilters. These characterizations involve closure structures on the set of ultrafilters. The case of productively Frechet filters answers a question of S. Dolecki and turns out to be the only one involving a non topological closure structure.
An artificial acyl-enzyme and an artificial enzyme

The synthesis and characterization of an artificial acyl-enzyme intermediate of chymotrypsin, and an artificial enzyme, chymotrypsin, are described. They both contain the same three catalytic groups, an imidazolyl group, a hydroxyl group, and a carboxylate ion. In the acyl-enzyme, the three groups are attached to a norbornane backbone, but in the artificial enzyme, the three catalytic groups are attached to a cycloamylose as binder. The artificial acyl-enzyme shows a rate of hydrolysis 154,000 times faster than an ordinary ester and only 18-fold slower than the real acyl-chymotrypsin. The artificial chymotrypsin is over a thousand fold slower than real chymotrypsin, presumably because of impurities in the preparation.
Anchorage in orthodontics

Abstract Nothing particularly new has been uncovered concerning anchorage in orthodontics. Only some conceptions of its application may be questioned or need clarification. The consideration of anchorage as used in orthodontics is simplified if anchorage is thought of entirely in terms of varying degrees of resistance to the applied force. When force is applied to teeth only, it becomes necessary to evaluate carefully the type and varying degrees of resistance offered by the dental units in order to produce movement or change where desired, without producing movement or change in units where movement or change is not desired. In this connection, anchorage is a very important consideration. The problem of anchorage becomes insignificant when the main resistance to the force is extraoral. Anchorage is a less significant problem if holding arches or stabilizing plates are used as a means of reinforcement. Anchorage preparation is not essential if the, resistance is derived from extraoral appliances or from holding arches or stabilizing plates. Action of the musculature complicates the anchorage problem during treatment and retention, either directly or through the inclined planes of the teeth. The interseptal tissues also present an anchorage problem during tooth movement and retention. The use of Class II elastics may result in positioning the mandibular denture more forward in relation to the body of the mandible, regardless of the appliance used on the mandibular denture. This appears to happen more readily, however, when the lingual arch is used for anchorage than when the full-banded appliance is employed. It follows that there is more possibility of shifting the mandibular denture forward when Class II elastics are used to produce en masse distal movement of the maxillary denture than when sectional tooth movement is utilized.
Measurement of polymer viscoelastic response during an impact experiment

Instrumented impact data on polymers typically show high frequency oscillations that decay in amplitude during the impact event. By undertaking a complete impact analysis including effects of inertial loading, external damping (friction), and internal damping (viscoelastic relaxations), we have been able to predict all the details of the high frequency oscillations. The most consistent analysis of impact data on Delrin® 100 polyacetal is one that ignores friction and attributes the decay of the high frequency oscillations to the effect of viscoelastic relaxations in the polymer. The impact analysis therefore allows us to extract viscoelastic relaxation information from Instrumented impact data. It is further suggested that this direct observation of viscoelastic relaxations during impact testing should make it possible to make a quantitative assessment of the role that viscoelastic relaxations play in influencing the impact toughness of polymers.
Mostly concurrent compaction for mark-sweep GC

A memory manager that does not move objects may suffer from memory fragmentation. Compaction is an efficient, and sometimes inevitable, mechanism for reducing fragmentation. A Mark-Sweep garbage collector must occasionally execute a compaction, usually while the application is suspended. Compaction during pause time can have detrimental effects for interactive applications that require guarantees for maximal pause time. This work presents a method for reducing the pause time created by compaction at a negligible throughput hit. The solution is most suitable when added to a Mark-Sweep garbage collector.Compaction normally consists of two major activities: the moving of objects and the update of all the objects' references to the new locations. We present a method for executing the reference updates concurrently, thus eliminating a substantial portion of the pause time hit. To reduce the time for moving objects in each compaction, we use the existing technique of incremental compaction, but select the optimal area to compact. Selecting the area is done after executing the mark and sweep phases, and is based on their results.We implemented our compaction on top of the IBM J9 JVM V2.2, and present measurements of its effect on pause time, throughput, and mutator utilization. We show that our compaction is indeed an efficient fragmentation reduction tool, and that it improves the performance of a few of the benchmarks we used, with very little increase in the pause time (typically far below the cost of the mark phase).
Endogenous choice of amendment agendas: types of voters and experimental evidence

A stylized model of three parties choosing an amendment agenda and voting over three policy alternatives is analyzed. The analysis yields a classification of five types of voters: random, sincere, strategic, risk-averse, and EUS (expected utility sophisticated) proposed by Enelow (J. Polit. 43:1062–1089, 1981). Laboratory experiments suggest that the choice of agendas can be partially explained by the sincere voting model (26% of voters) and strategic voting model (47% of voters), even when players’ preferences are common knowledge. Risk-aversion may explain choices of up to 56% of the voters. Finally, the EUS voting model explains up to 73% of the observed voting behavior.
Predicting abuse potential of stimulants and other dopaminergic drugs: Overview and recommendations

Examination of a drug's abuse potential at multiple levels of analysis (molecular/cellular action, whole-organism behavior, epidemiological data) is an essential component to regulating controlled substances under the Controlled Substances Act (CSA). We reviewed studies that examined several central nervous system (CNS) stimulants, focusing on those with primarily dopaminergic actions, in drug self-administration, drug discrimination, and physical dependence. For drug self-administration and drug discrimination, we distinguished between experiments conducted with rats and nonhuman primates (NHP) to highlight the common and unique attributes of each model in the assessment of abuse potential. Our review of drug self-administration studies suggests that this procedure is important in predicting abuse potential of dopaminergic compounds, but there were many false positives. We recommended that tests to determine how reinforcing a drug is relative to a known drug of abuse may be more predictive of abuse potential than tests that yield a binary, yes-or-no classification. Several false positives also occurred with drug discrimination. With this procedure, we recommended that future research follow a standard decision-tree approach that may require examining the drug being tested for abuse potential as the training stimulus. This approach would also allow several known drugs of abuse to be tested for substitution, and this may reduce false positives. Finally, we reviewed evidence of physical dependence with stimulants and discussed the feasibility of modeling these phenomena in nonhuman animals in a rational and practical fashion. This article is part of the Special Issue entitled 'CNS Stimulants'.
Evidence for excitatory amino acid neurotransmitters in forward and feedback corticocortical pathways within rat visual cortex.

It is a commonly accepted notion that cells which make projections between the multiple cortical areas found in the mammalian visual system are excitatory, but there is little direct evidence that this is the case. Here we demonstrate using retrograde tracing with D-[3H]aspartate that connections in the rat which project from lower to higher visual areas (i.e. forward) and those which project from higher to lower areas (i.e. feedback) may use excitatory amino acid neurotransmitters. Following injection into the primary visual cortex, clusters of retrogradely labelled cells were found in several extrastriate areas within the cytoarchitectonic subdivisions 18a (‘areas’ LM, AL, PX, FLX, RL, AX) and 18b (‘area’ MX), and in the retrosplenial cortex. In all of these areas D-[3H]aspartate-labelled cells were surrounded by diffuse label which may represent anterograde labelling of axon terminals. This suggests that both legs of reciprocal intracortical circuits have similar chemospecificity. To directly demonstrate excitatory amino acid localization in forward projections, D-[3H]aspartate was injected into extrastriate area LM. As expected, the results revealed retrogradely labelled neurons within area 17. Outside area 17, LM injections labelled neurons in AL, PX, FLX, RL, AX and MX. Taken in the context of the hierarchy of areas in rat cerebral cortex (Coogan and Burkhalter, J. Neurosci., 13, 3749–3772, 1993), these results show that D-[3H]aspartate labels: (1) forward connections from area 17 to LM, AL, PX, RL, AX and MX, (2) feedback connections from LM, AL, FLX, PX, RL, AX and MX to area 17, (3) feedback connections from AL, PX, RL, AX and MX to LM, and (4) lateral connections between FLX and LM. These findings strongly indicate that both forward and feedback connections as well as lateral connections at several different levels of the cortical hierarchy use excitatory amino acid neurotransmitters.
Family History of Alcoholism Influences Naltrexone-Induced Reduction in Alcohol Drinking

Background The purpose of this study was to examine the interactive effects of family history of alcoholism (FH+, FH−) and naltrexone dose (0, 50, 100 mg/day) on alcohol drinking. Methods Ninety-two, non–treatment-seeking alcohol-dependent participants received naltrexone daily for 6 days. On the 6th day, they participated in a laboratory paradigm involving exposure to a priming dose of alcohol followed by a 2-hour drinking period in which they made choices between consuming alcoholic drinks and receiving money. Results Total number of drinks consumed during the drinking period was significantly decreased by the 100-mg dose of naltrexone in FH+ drinkers. Secondary analyses in male drinkers ( n = 70) indicated that 100 mg of naltrexone significantly decreased drinking in FH+ participants and increased drinking in FH− drinkers. Conclusions These results suggest that family history of alcoholism might be a significant clinical predictor of response to naltrexone and that FH+ men are more likely to benefit from naltrexone therapy for alcohol drinking.
A critical review of theoretical frameworks for dating violence: Comparing the dating and marital fields

Recent studies have focused on the widespread problem of violence among adolescent and college aged dating couples. Much of this research has focused on identifying risk factors and correlates of dating violence, along with implementing intervention and prevention programs for the amelioration of this aberrant behavior. However, limited discussion exists within the literature on theoretical frameworks to explain dating violence or the relationship between dating and marital violence. The present paper sought to critically review existing theories that have been postulated for intimate partner aggression in general and specifically for dating violence. The similarities and differences between dating violence and marital violence are also examined, with a discussion on how a theoretical framework developed to examine marital aggression can be effectively applied to violent dating relationships. Suggestions for future research on theoretical conceptualizations of dating violence and the co-examination of dating and marital violence are discussed.
AN INTERTWINING OPERATOR FOR THE GROUP B 2

There is a commutative algebra of differential-difference operators, acting on polynomials on , associated with the reflection group B 2 . This paper presents an integral transform which intertwines this algebra, allowing one free parameter, with the algebra of partial derivatives. The method of proof depends on properties of a certain class of balanced terminating hypergeometric series of 4 F 3 -type. These properties are in the form of recurrence and contiguity relations and are proved herein.
Quantification of advanced turboprop aircraft flyover noise annoyance

A laboratory experiment was conducted to quantify the annoyance to advanced turboprop (propfan) aircraft flyover noise. A computer synthesis system was used to generate 45 realistic, time varying simulations of propeller aircraft flyover noise in which the tonal content was systematically varied to represent the factorial combinations of five fundamental frequencies, three frequency envelope shapes, and three tone-to-broadband noise ratios. In the experiment, 64 subjects judged the annoyance of recordings of the 45 synthesized flyover noises presented at three sound levels in a test facility which simulates the outdoor acoustic environment. Analyses of the judgements showed that frequency envelope shape did not significantly affect annoyance. The interaction of fundamental frequency with tone-to-broadband noise ratio did have a large and complex effect on annoyance. Duration corrected A-weighted sound pressure level with a modified tone correction predicted annoyance better than any other measurement procedure.
Oxygen derived radicals related injury in the heart during calcium paradox.

The effects of oxygen-derived radical scavengers (ODRS) on the heart was investigated during the calcium paradox. Perfusion with Ca2 +-free medium caused cell separation at the intercalated discs and changes in the endothelial cells. Upon Ca2+ reintroduction, a massive cell damage occurred. The cytosolic enzyme, creatine phosphokinase (CPK), was released in large amounts (p< 0.001). The tissue adenosine triphosphate (ATP) was reduced to 3.7 μmol/g dry weight from the control value of 21.6 μmol/g dry weight and tissue Ca2+ content was increased threefold. The treatment with Superoxide dismutase (SOD) and catalase (CAT) increased percentage of normal cells (62.2%) compared to nontreated Ca2+ paradox group (0.2%) and caused negligible leakage of CPK. Tissue ATP was preserved (p<0.03), and Ca2+ content was also reduced in the hearts treated with SOD and CAT (p<0.03). The cell membranes and vascular endothelium were well preserved in the hearts treated with SOD and CAT. Boiled SOD and CAT administered were totally ineffective. It is suggested that oxygen-active species may have a role in the Ca2+ paradox injury.
Identification of twenty-three mutations in fission yeast Scap that constitutively activate SREBP

The endoplasmic reticulum membrane protein SREBP cleavage-activating protein (Scap) senses sterols and regulates activation of sterol-regulatory element binding proteins (SREBPs), membrane-bound transcription factors that control lipid homeostasis in fission yeast and mammals. Transmembrane segments 2–6 of Scap function as a sterol-sensing domain (SSD) that recognizes changes in cellular sterols and facilitates activation of SREBP. Previous studies identified conserved mutations Y298C, L315F, and D443N in the SSD of mammalian Scap and fission yeast Scap (Scp1) that render cells insensitive to sterols and cause constitutive SREBP activation. In this study, we utilized fission yeast genetics to identify additional functionally important residues in the SSD of Scp1 and Scap. Using a site-directed mutagenesis selection, we sampled all possible amino acid substitutions at 50 conserved residues in the SSD of Scp1 for their effects on yeast SREBP (Sre1) activation. We found mutations at 23 different amino acids in Scp1 that rendered Scp1 insensitive to sterols and caused constitutive activation of Sre1. To our surprise, the majority of the homologous Scap mutants displayed wild-type function, and only one mutation, V439G, caused constitutive activation of SREBP in mammals. These results suggest that the sterol-sensing mechanism of Scap and the functional requirements for SREBP activation are different between fission yeast and mammals.