cssi/SciSciGPT-SciSciNet huggingface dataset:
Arrest of Replication Fork Progression at Sites of Topoisomerase II-Mediated DNA Cleavage in Human Leukemia CEM Cells Incubated with VM-26†

Recent studies have shown that the anticancer drugs VM-26 and mitoxantrone stabilize preferentially the binding of topoisomerase IIalpha to replicating compared to nonreplicating DNA. To further understand the mechanisms by which cleavable complex-forming topoisomerase II inhibitors interfere with DNA replication, we examined the effects of VM-26 on this process in human leukemia CEM cells. Both the inhibition of DNA synthesis and cell survival were directly related to the total amount of drug-stabilized cleavable complexes formed in VM-26-treated cells. DNA chain elongation was also inhibited in a concentration-dependent fashion in these cells, which suggested that VM-26-stabilized cleavable complexes interfered with the movement of DNA replication forks. To test this hypothesis directly, we monitored replication fork progression at a specific site of VM-26-induced DNA cleavage. A topoisomerase II-mediated cleavage site was detected in the first exon of the c-myc gene in VM-26-treated cells. This cleavage site was downstream of a putative replication origin located in the 5' flanking region of the gene. Replication forks, which moved through this region of the c-myc gene in the 5' to 3' direction, were specifically arrested at this site in VM-26-treated cells, but not in untreated or aphidicolin-treated cells. These studies provide the first direct evidence that a VM-26-stabilized topoisomerase II-DNA cleavable complex acts as a replication fork barrier at a specific genomic site in mammalian cells. Furthermore, the data support the hypothesis that the replication fork arrest induced by cleavable complex-forming topoisomerase II inhibitors leads to the generation of irreversible DNA damage and cytotoxicity in proliferating cells.
Calcified postoperative epicardial granuloma.

Abstract A sterile calcified granuloma on the external surface of a right ventriculotomy in an 8-year-old boy was identified four years after closure of a ventricular septal defect. He had no symptoms, but a systolic ejection murmur was identified and disappeared after resection of the lesion. Sensitivity to silk suture material is suggested by the operative findings and a history of multiple silk suture sinuses developing in his uninfected original thoracotomy incision.
The role of excitatory amino acid transmission within the rostral ventromedial medulla in the antinociceptive actions of systemically administered morphine.

Two classes of neurons with distinct responses to opioids have been identified in the rostral ventromedial medulla (RVM), a region with a well-documented role in nociceptive modulation. 'Off-cells' are activated, indirectly, by opioids, and are likely to exert a net inhibitory effect on nociceptive processing. 'On-cells' are directly inhibited by opioids, and there is evidence that these neurons can, under various conditions, facilitate nociception. We showed previously that excitatory amino acid (EAA) neurotransmission is crucial to the nocifensor reflex-related on-cell burst, but plays little role in maintaining the ongoing activity of off-cells. The aim of the present study was to determine whether EAA transmission contributes to the activation of off-cells and the concomitant behavioral antinociception that follow systemic opioid administration. The non-selective EAA receptor antagonist kynurenate was infused into the RVM (1 nmol/200 nl) of lightly anesthetized rats prior to administration of morphine (1.5 mg/kg i.v). Off-cell, on-cell and neutral cell firing, as well as, tail flick response (TF) latencies were recorded. Kynurenate, significantly attenuated the characteristic opioid activation of off-cells. As a group, off-cells in kynurenate-treated animals did not become continuously active, and continued to exhibit tail-flick related pauses in firing. On-cell and neutral cell responses to opioid administration were unchanged. Opioid inhibition of the TF was also reduced, although baseline TF latency was unaffected, by RVM kynurenate. EAA-mediated activation of off-cells, thus has an important role in opioid analgesia. The present observations underscore the importance of excitatory interactions among opioid-sensitive nociceptive modulatory circuits for systemic morphine analgesia, suggesting that such interactions are a critical factor in the synergistic relationships which have been demonstrated among these sites.
Heterodyne laser radar array receivers for the mitigation of target-induced speckle

We investigated a space diversity optical heterodyne array receiver for optimal coherent detection of finite transverse coherence length fields. In such an array receiver, each of the independent IF signals are appropriately phase-shifted and summed to generate a single IF signal with improved statistical qualities. In this paper we show that the advantages offered by a coherent array are both an increased average carrier-to-noise ratio and a reduction in carrier fading. We also show that the equal gain diversity reception technique performs almost as well as the maximal ratio technique with significantly less hardware complexity. Finally, we present the experimental results from a two element, one micron, laboratory breadboard ladar system.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Ultrastructure of the eggs of Reduviidae. II: Eggs of Harpactorinae (Insecta: Heteroptera)

Eggs of Piratinae are unique among reduviids in possessing stellate chorionic filaments that remain exposed even after the insertion of the egg into the ground. These eggs have developed many structures for supplying ambient oxygen to the developing embryo inside them. The ultrastructure of the chorion, the operculum and the aeromicropylar system of the eggs of seven species of piratinae bugs are reported.
The use of polyurethane materials in the surgery of the spine: a review.

Abstract Background context The spine contains intervertebral discs and the interspinous and longitudinal ligaments. These structures are elastomeric or viscoelastic in their mechanical properties and serve to allow and control the movement of the bony elements of the spine. The use of metallic or hard polymeric devices to replace the intervertebral discs and the creation of fusion masses to replace discs and/or vertebral bodies changes the load transfer characteristics of the spine and the range of motion of segments of the spine. Purpose The purpose of the study was to survey the literature, regulatory information available on the Web, and industry-reported device development found on the Web to ascertain the usage and outcomes of the use of polyurethane polymers in the design and clinical use of devices for spine surgery. Study design/setting A systematic review of the available information from all sources concerning the subject materials' usage in spinal devices was conducted. Methods A search of the peer-reviewed literature combining spinal surgery with polyurethane or specific types and trade names of medical polyurethanes was performed. Additionally, information available on the Food and Drug Administration Web site and for corporate Web sites was reviewed in an attempt to identify pertinent information. Results The review captured devices that are in testing or have entered clinical practice that use elastomeric polyurethane polymers as disc replacements, dynamic stabilization of spinal movement, or motion limitation to relieve nerve root compression and pain and as complete a listing as possible of such devices that have been designed or tested but appear to no longer be pursued. This review summarizes the available information about the uses to which polyurethanes have been tested or are being used in spinal surgery. Conclusions The use of polyurethanes in medicine has expanded as modifications to the stability of the polymers in the physiological environment have been improved. The potential for the use of elastomeric materials to more closely match the mechanical properties of the structures being replaced and to maintain motion between spinal segments appears to hold promise. The published results from the use of the devices that are discussed show early success with these applications of elastomeric materials.
Activation of Broca's area by syntactic processing under conditions of concurrent articulation

Regional cerebral blood flow (rCBF) was measured with positron emission tomography (PET) when 11 subjects made plausibility judgments about written sentences that varied in their syntactic complexity. While making their judgments, subjects uttered the word “double” aloud at a rate of one utterance per second to inhibit their ability to rehearse the sentences. Blood flow increased in Broca's area when subjects made judgments about the more complex sentences. This result replicates and extends previous findings that blood flow increases in this region when subjects process complex syntax under no interference conditions. The results of this experiment provide strong evidence that the increase in blood flow seen in Broca's area in association with processing syntactically complex structures is not due to subvocal rehearsal of those structures, but rather results from processing syntactic forms themselves. Hum. Brain Mapping 9:65–71, 2000. © 2000 Wiley-Liss, Inc.
Extending the information delivery manual approach to identify information requirements for performance analysis of HVAC systems

Heating, Ventilation and Air-Conditioning (HVAC) systems account for more than 15% of the total energy consumption in the US. In order to improve the energy efficiency of HVAC systems, researchers have developed hundreds of algorithms to automatically analyze their performance. However, the complex information, such as configurations of HVAC systems, layouts and materials of building elements and dynamic data from the control systems, required by these algorithms inhibits the process of deploying them in real-world facilities. To address this challenge, we envision a framework that automatically integrates the required information items and provides them to the performance analysis algorithms for HVAC systems. This paper presents an approach to identify and document the information requirements from the publications that describe these algorithms. We extend the Information Delivery Manual (IDM) approach so that the identified information requirements can be mapped to multiple information sources that use various formats and schemas. This paper presents the extensions to the IDM approach and the results of using it to identify information requirements for performance analysis algorithms of HVAC systems.
Looking in text windows: their size and composition

Abstract A text window is a group of words appearing in contiguous positions in text. Intuitively, words in such close proximity should have something to do with each other. We can use the text window to exploit a variety of lexical, syntactic, and semantic relationships without having to analyze the text explicitly for their structure. This research supports the previously suggested idea that natural groupings of words are best treated as a unit of size 7 to 11 words, that is, plus or minus three to five words. Our text retrieval experiments varying the size of windows, both with full text and with stopwords removed, support these size ranges. The characteristics of windows that best match terms in queries are examined in detail, revealing interesting differences between those for queries with good results and those for queries with poorer results. Queries with good results tend to contain more content word phrases and fewer terms with high frequency of use in the database. Information retrieval systems may benefit from expanding thesaurus-style relationships or incorporating statistical dependencies for terms within these windows.
Source separation in noisy and reverberant environment using miniature microphone array

In the unique framework that combines spatial sensing and independent component analysis, we recover the impinging acoustic sources and estimate their direction of arrival on the miniature four microphone array. We examine and quantify the performance of the proposed algorithm under different acquisition noise and reverberant conditions. With artificially generated microphone signals using room acoustic model, the algorithm demonstrates over 10 dB separation in moderate reverberant environments. With the recordings from a miniature microphone array in a typical conference-room environment, the algorithm demonstrates over 10 dB separation performance if the angular distance between two speech sources is over 30 degrees.
Expression of mineralocorticoid and glucocorticoid receptors in preautonomic neurons of the rat paraventricular nucleus

Activation of mineralocorticoid receptors (MR) of the hypothalamic paraventricular nucleus (PVN) increases sympathetic excitation. To determine whether MR and glucocorticoid receptors (GR) are expressed in preautonomic neurons of the PVN and how they relate to endogenous aldosterone levels in healthy rats, retrograde tracer was injected into the intermediolateral cell column at T4 to identify preautonomic neurons in the PVN. Expression of MR, GR, 11-β hydroxysteroid dehydrogenase1 and 2 (11β-HSD1, 2), and hexose-6-phosphate dehydrogenase (H6PD) required for 11β-HSD1 reductase activity was assessed by immunohistochemistry. RT-PCR and Western blot analysis were used to determine MR gene and protein expression. Most preautonomic neurons were in the caudal mediocellular region of PVN, and most expressed MR; none expressed GR. 11β-HSD1, but not 11β-HSD2 nor H6PD immunoreactivity, was detected in the PVN. In rats with chronic low or high sodium intakes, the low-sodium diet was associated with significantly higher plasma aldosterone, MR mRNA and protein expression, and c-Fos immunoreactivity within labeled preautonomic neurons. Plasma corticosterone and sodium and expression of tonicity-responsive enhancer binding protein in the PVN did not differ between groups, suggesting osmotic adaptation to the altered sodium intake. These results suggest that MR within preautonomic neurons in the PVN directly participate in the regulation of sympathetic nervous system drive, and aldosterone may be a relevant ligand for MR in preautonomic neurons of the PVN under physiological conditions. Dehydrogenase activity of 11β-HSD1 occurs in the absence of H6PD, which regenerates NADP+ from NADPH and may increase MR gene expression under physiological conditions.
A steroid inhibitory effect on adrenal mitochondria.

Corticosterone has been reported to inhibit the in vitro incorporation of 14Cleucine into rat adrenal protein. In the present study this inhibition of 14C-leucine incorporation by corticosterone in adrenal homogenates was reversed by the addition of .5 mM ATP and an ATP generating system. Corticosterone 100 μg/ml inhibited respiration in “coupled” adrenal mitochondria in the presence of 5 mM ketoglutarate but not with 5 mM succinate, suggesting a block at the DPNH oxidase site. Rotenone, a specific inhibitor at this site, also inhibited adrenal protein synthesis and blocked the ACTH stimulation of corticosterone production in rat adrenal quarters. The conversion of corticosterone to aldosterone was inhibited by testosterone 100 μg/ml in the presence of both succinate and TPNH as substrates. Further studies suggested that testosterone was a competitive inhibitor for the conversion of corticosterone to aldosterone. These data suggest that steroids inhibit adrenal protein synthesis and block the ACTH stimula...
A New Species of Manure-Inhabiting Mite in the Genus Poecilochirus (Acari: Mesostigmata: Parasitidae) Predacious on House Fly Eggs and Larvae

Poecilochirus monospinosus Wise, Hennessey & Axtell, new species, is described from specimens collected and reared from poultry manure from Chatham and Wake Counties, N.C. The larva, protonymph, deutonymph, and adult stages are described and figured. Data are given on the duration of the life stages, fecundity, and rates of predation by deutonymphs and adult females on house fly ( Musca domestica L.) eggs and first instars at 26.6°C. Keys are given to the deutonymphs, females, and males of the described species of the genus Poecilochirus of the world.
Implanted He retention and release from boronized layers

He has been implanted at an energy of 3 keV into amorphous hydrogenated boron-carbon (a-BC) films deposited by rf sputtering onto single crystal Si substrates. The initial composition of the films was analyzed by nuclear-enhanced backscattering spectrometry to be B2C with ∼20% H and ∼10% O. The areal density of the implanted and retained 3He was measured in situ by a new ion beam analysis technique using the 3He(3He, pp) three-body nuclear reaction. The He trapping or pumping efficiency at room temperature is only 3.4% for low fluence implants and the a-BC layer saturates with He at a fluence of 5×1017 He/cm2. At this saturation fluence, only 3.1×1015 He/cm2 is retained in the film. Isochronal annealing of the implanted samples reveals a distributed release of implanted He at ∼200°C, which corresponds to a trap activation energy of 1.65±0.25 eV. 3He was trapped less efficiently at 250°C than at room temperature and exhibited a saturated retention of 8.6×1014 He/cm2. These results indicate that wall pumping should play only a minor role in the interpretation of the Textor He-pump experiment carried out earlier this year. The results also show that the unintentional deposition of a-BC, onto He pumping plates could adversely affect the operation of such devices, and should therefore be avoided.
Public vs. private insurance: Cost, use, accessibility, and outcomes of services for children with autism spectrum disorders

Abstract Very little research has been conducted on insurance type (private vs. public funded) and costs, accessibility, and use of services of children with autism. Analysis of five parent reported outcomes: (a) out-of-pocket expenditures, (b) variety of services used, (c) access to services, (d) child and family service outcomes, and (e) satisfaction with payer of services against private and public insurance was completed. Parents/caregivers completed a survey regarding recent usage of nine specific services—inpatient care, medication management, counseling or training, individual therapy, in-home behavior therapy, speech and language therapy, occupational therapy, case management, and respite care. Across all respondents (n = 107), 73.5% were privately insured; 21.2% were publicly insured. Based on insurance type, no statistically significant differences in outcome variables were found, findings that were not consistent with previous research. However, an indirect association was found between out-of-pocket expense and parent satisfaction with the payer of services, access to care, and family outcomes. Further, a significantly higher percentage of total out-of-pocket expenditures were allocated to speech language therapy among publicly insured children than among privately insured children (p = .03) and parent stress was a moderating variable between access to care and variety of services used.
Observation of d-Spacing Fluctuations above the Martensitic Phase Transition in V 3 Si

High-resolution x-ray-scattering studies of the Martensitic phase transition in ${\mathrm{V}}_{3}$Si show significant pretransition $d$-spacing fluctuations at temperatures as high as 40 K above ${T}_{\mathrm{M}}(21 \mathrm{K})$. Neutron scattering measurements, with similar resolution, show no broadening of the same Bragg peak. These striking results are compared with existing theoretical and experimental evidence for precursive effects in ${\mathrm{V}}_{3}$Si.
Autoradiographic visualisation of [3H]5-carboxamidotryptamine binding sites in the guinea pig and rat brain.

Abstract We have investigated the distribution of [3H]5-carboxamidotryptamine ([3H]5-CT) binding sites by in vitro autoradiography on sections of guinea-pig and rat brain. In saturation studies, the ligand recognised a saturable, homogeneous population of binding sites with an affinity ranging from 0.19–0.45 nM depending on the region. The labelling pattern was heterogeneous, and the displacement pattern with different competing drugs selective for different 5-HT receptor subtypes was complex. [3H]5-CT appeared to label 5-HT 1B 5-HT 1D sites in the substantia nigra, globus pallidus and caudate/putamen, as the binding in these regions was displaced by the 5-HT 1B 1D receptor selective agents sumatriptan, CP-122,288 and GR-127,935. In the hippocampus and lateral septum, the very dense [3H]5-CT binding was displaced with high affinity by the 5-HT1A receptor selective agonist 8-hydroxy-dipropylaminotetralin ((±)-8-OH-DPAT), dihydroergotamine and 5-HT. In contrast the affinity of the 5-HT1 receptor antagonists spiperone and methiothepine was much lower than their previously published potency at 5-HT1A receptors. The affinity of agonists, taken together with the fact that the distribution of these [3H]5-CT sites overlaps that of [3H]8-OH-DPAT binding sites in serial sections, suggest that these sites correspond to 5-HT1A receptors. Their atypical properties deserve further investigations. While [3H]5-CT binding at 5-HT 1B 1D sites and these atypical 5-HT1A sites was inhibited by the GTP analogue 5′-β,γ-imidotriphosphate, [3H]5-CT binding in the superficial cortical layers and in midline thalamic nuclei was insensitive to this agent. It was however displaced by low concentrations of spiperone, clozapine and methiothepine, but not by sumatriptan, CP-122,288, GR-127,935 or dihydroergotamine. This binding profile is similar to that of 5-HT7 receptors, while the spatial distribution of these sites matches the known distribution of 5-HT7 messenger RNA. We did not find evidence of [3H]5-CT labelling to 5-HT5 receptors, in spite of their reported high affinity for this ligand. It is concluded that [3H]5-CT, in the presence of selective blockers, can be used to investigate the properties of 5-HT1A, 5-HT 1B 1D and 5-HT7 receptors in the rodent brain, although further studies are required to explain the atypical features of [3H]5-CT binding in 5-HT1A receptors containing regions.
Leisure activities and the risk of amnestic mild cognitive impairment in the elderly

Objective: To study the influence of leisure activity participation on risk of development of amnestic mild cognitive impairment (aMCI). Methods: The authors examined the relationship between baseline level of participation in leisure activities and risk of aMCI in a prospective cohort of 437 community-residing subjects older than 75 years, initially free of dementia or aMCI, using Cox analysis adjusted for age, sex, education, and chronic illnesses. The authors derived Cognitive and Physical Activity Scales based on frequency of participation in individual activities. Results: Over a median follow-up of 5.6 years, 58 subjects had development of aMCI. A one-point increase on the Cognitive (hazard ratio [HR] 0.95, 95% CI 0.91 to 0.99) but not Physical Activities Scale (HR 0.97, 95% CI 0.93 to 1.01) was associated with lower risk of aMCI. Subjects with Cognitive Activity scores in the highest (HR 0.46, 95% CI 0.24 to 0.91) and middle thirds (HR 0.52, 95% CI 0.29 to 0.96) had a lower risk of aMCI compared with subjects in the lowest third. The association persisted even after excluding subjects who converted to dementia within 2 years of meeting criteria for aMCI. Conclusions: Cognitive activity participation is associated with lower risk of development of amnestic mild cognitive impairment, even after excluding individuals at early stages of dementia.
Aromatic‐backbone interactions in model α‐helical peptides

The effects on helical stability of weak polar interactions between aromatic side-chains and the peptide backbone were examined. α-Helical model peptides, hexa-Ala, with sequential Tyr replacement, were investigated computationally to obtain the geometries and energetics of the interactions. Geometries were obtained with the B3LYP/6-31G* level of theory. Interaction energies were calculated using BHandHLYP/cc-pVTZ and an improved method to correct for basis set superposition error when fragmentation caused steric clashes. Both i, i + 1 and i, i − 4 interactions were observed when Tyr was in position i = 5. The position of the aromatic residue in the amino acid sequence was crucial in facilitating aromatic-backbone interactions. The distance between the center of the aromatic ring of Tyr and the individual interacting backbone atoms ranged from 3.65 to 5.50 A. The interactions have energies of the same order as hydrogen bonds and, thus, could have a significant impact on the stability of the helix. © 2007 Wiley Periodicals, Inc. J Comput Chem, 2007
Properties of maximum likelihood estimates of the ratio of parameters in ordinal response regression models

The properties of a method of estimating the ratio of parameters for ordered categorical response regression models are discussed. If the link function relating the response variable to the linear combination of covariates is unknown then it is only possible to estimate the ratio of regression parameters. This ratio of parameters has a substitutability or relative importance interpretation. The maximum likelihood estimate of the ratio of parameters, assuming a logistic function (McCullagh, 1980), is found to have very small bias for a wide variety of true link functions. Further it is shown using Monte Carlo simulations that this maximum likelihood estimate, has good coverage properties, even if the link function is incorrectly specified. It is demonstrated that combining adjacent categories to make the response binary can result in an analysis which is appreciably less efficient. The size of the efficiency loss on, among other factors, the marginal distribution in the ordered categories
The Earth System: An Introduction to Earth Systems Science

The atmosphere, hydrosphere, biosphere, and solid Earth are the basic components of the Earth system. These different components are not separate entities; instead they interact over a broad range of spatial and temporal scales. Determining how various internal and external influences impact each component of the Earth system individually is challenging. It is even more difficult to understand how the various components interact to yield the response of the entire Earth system to different forcings. This, however, is the critical task global change scientists must face in order to assess how various human activities, such as emissions of greenhouse gases, impact the environment.
Molecular geometries and moments from the maximum overlap criterion

Abstract The maximized overlap population, defined as Σμ≠νPμνSμν, and a related quantity, Σμ,νPμνS2μν are computed for a series of configurations. The extremum of both approximate molecular geometries, the latter with an accuracy suitable for predictive value. The maximum overlap orbitals predict dipole and quadrupole moments that give reasonable agreement with experimental values.
Sufficient conditions for constructing methods faster than Newton's

In this study we use inexact Newton-like methods to approximate a locally unique solution of a nonlinear operator equation in a Banach space. Using the majorant method and Newton Kantorovich-type hypotheses we provide sufficient convergence conditions and an error analysis for our method. Our method is also shown under very natural assumptions to be faster than Newton's under the same computational cost. Finally we apply our results to solve nonlinear integral equations appearing in radiative transfer in connection with the problem of determination of the angular distribution of the radiant-flux emerging from a plane radiation field.
Uniform high bandwidth, high CW power VCSEL arrays

A high bandwidth, high power, 980 nm vertical-cavity surface-emitting laser (VCSEL) array with 3dB frequency response over 7.5 GHz and continuous wave (CW) power of greater than 120 mW at room temperature is reported.
The Role of Roots in the Perception of a Destination: An Exploratory Study on Sicily

ABSTRACT This study was conducted to determine the effect of ancestry on perception of Sicily as a tourist destination. Central Florida students' perception of Sicily was explored using a combination of qualitative and quantitative design with a sample of 276 students. While all respondents perceived Sicily as a tourist destination rich in scenery, culture and sun, sand and sea opportunities, those students with Italian ancestors had a statistically more significant positive image of Sicily.
Scheduling a capacitated batch-processing machine to minimize makespan

This paper aims at improving the utilization of a single batch-processing machine. The batch-processing machine can process a batch of jobs, as long as the number of jobs and the total size of all the jobs in a batch do not violate the machine's capacity. The processing time of the job and its size is known. The processing time of a batch is the longest processing time among all the jobs in the batch. The objective is to minimize the makespan. Since the problem under study is NP-hard, a Simulated Annealing (SA) approach is proposed. The effectiveness of our solution procedure in terms of solution quality and run time is evaluated through experiments. The results obtained from the SA approach were compared with a commercial solver called CPLEX. Our computational study demonstrates the effectiveness of our approach in solving problem instances with 20 or more jobs in a shorter run time with better solutions.
Ligand-Accelerated C–H Activation Reactions: Evidence for a Switch of Mechanism

Initial rate studies have revealed dramatic acceleration in aerobic Pd(II)-catalyzed C-H olefination reactions of phenylacetic acids when mono-N-protected amino acids are used as ligands. In light of these findings, systematic ligand tuning was undertaken, which has resulted in drastic improvements in substrate scope, reaction rate, and catalyst turnover. We present evidence from intermolecular competition studies and kinetic isotope effect experiments that implies that the observed rate increases are a result of acceleration in the C-H cleavage step. Furthermore, these studies suggest that the origin of this phenomenon is a change in the mechanism of C-H cleavage from electrophilic palladation to proton abstraction.
Delivering an Organizational Leadership PhD Program at a Distance: University of Oklahoma

The authors review key features in the development of a successful PhD program delivered at a distance, including students, cohorts, teaching, curriculum, administrative structure, and current and future challenges.
Hot-Tearing Susceptibility of Ternary Mg-Al-Sr Alloy Castings

The susceptibility of Mg-Al-Sr alloys to hot tearing during permanent mold casting was investigated using constrained rod casting (CRC) in a steel mold. The alloys included Mg-xAl-1.5Sr and Mg-xAl-3Sr, where x = 4, 6, or 8 wt pct. The hot-tearing susceptibility (HTS) was determined based on the widths and locations of the cracks in the rods. With the Mg-xAl-1.5 Sr alloys, the HTS decreased significantly with increasing Al content. With the Mg-xAl-3Sr alloys, the trend was similar but not as significant. At the same Al content, the HTS was significantly lower at 3 wt pct Sr than at 1.5 wt pct Sr. To help understand the HTS of these alloys, the solidification path and phase fractions were calculated for each alloy. The HTS was found to increase with increasing fraction solid at the end of primary solidification.
Computationalism in the Philosophy of Mind

Computationalism has been the mainstream view of cognition for decades. There are periodic reports of its demise, but they are greatly exaggerated. This essay surveys some recent literature on computationalism and reaches the following conclusions. Computationalism is a family of theories about the mechanisms of cognition. The main relevant evidence for testing computational theories comes from neuroscience, though psychology and AI are relevant too. Computationalism comes in many versions, which continue to guide competing research programs in philosophy of mind as well as psychology and neuroscience. Although our understanding of computationalism has deepened in recent years, much work in this area remains to be done.
Efficient recursive estimation; application to estimating the parameters of a covariance function

Abstract In many engineering applications, repeated observations of a random nature are made in an effort to estimate certain parameters associated with the observations. In such a situation, two considerations are usually of paramount importance: computational simplicity and asymptotic efficiency. Stochastic approximation methods were originally introduced to solve regression problems in which no information concerning the statistics of the observations was available beyond a knowledge that certain regularity properties were satisfied. However, a second advantage of these methods is their computational simplicity. We here show that if some knowledge of the statistics of the observations can be assumed, these methods can be modified to yield methods which are asymptotically efficient. Specifically, we consider an estimation method which recursively seeks a solution to the likelihood equation. This method possesses the simple computational structure of previous stochastic approximation methods and, under certain regularity conditions, we show the method to be asymptotically efficient. This method is then applied to the problem of estimating the parameters of the covariance function of a gaussian process.
Effects of acidic rain and ozone on nitrogen fixation and photosynthesis in the lichen Lobaria pulmonaria (L.) Hoffm.

Abstract The lichen Lobaria pulmonaria was subjected to ozone fumigations at 118, 235 and 353 μg/m 3 and simulated acidic rain at pH levels of 2.6, 4.2 and 5.6 for 5 days (M, W, F, M, W) during a 10-day period. Acidic rain at pH 2.6 caused significant reductions in nitrogen fixation and gross photosynthesis of 100 and 90%, respectively, and thallus bleaching was apparent. There were no significant differences between the pH 5.6 and 4.2 treatments in either gross photosynthesis or nitrogen fixation, and the color of the lichen thalli was unchanged. The effect of O 3 on nitrogen fixation and photosynthesis over the range of concentrations used was not significant, but there was a trend toward reduced nitrogen fixation with increasing O 3 concentration. There were no significant O 3 -acidic rain interactions. The threshold for response to rain acidity for L. pulmonaria lies between pH 2.6 and 4.2, and the acidity of wet deposition in parts of the United States may fall in this range.
Political Parties and Macroeconomic Policy

This study examines postwar patterns in macroeconomic policies and outcomes associated with left-and right-wing governments in capitalist democracies. It argues that the objective economic interests as well as the subjective preferences of lower income and occupational status groups are best served by a relatively low unemployment-high inflation macroeconomic configuration, whereas a comparatively high unemployment-low inflation configuration is compatible with the interests and preferences of upper income and occupational status groups. Highly aggregated data on unemployment and inflation outcomes in relation to the political orientation of governments in 12 West European and North American nations are analyzed revealing a low unemployment-high inflation configuration in nations regularly governed by the Left and a high unemployment-low inflation pattern in political systems dominated by center and rightist parties. Finally, time-series analyses of quarterly postwar unemployment data for the United States and Great Britain suggests that the unemployment rate has been driven downward by Democratic and Labour administrations and upward by Republican and Conservative governments. The general conclusion is that governments pursue macroeconomic policies broadly in accordance with the objective economic interests and subjective preferences of their class-defined core political constituencies.
Protest and Vocalizing Behavior of Cuddling and Noncuddling Infants to Different Textured Fabrics

Infants (M = 9 mo.), designated as “cuddlers” (N = 13) and “noncuddlers” (N = 7), responded differentially to fabrics located on a special floor that always contained three textures plus a fourth one, either a non-abrasive burlap or a coarse carpet material. Protests of the cuddlers were significantly higher than noncuddlers during exposure to the carpet. Cuddlers showed more positive vocalizing during exposure to the burlap than to the carpet Positive vocalizing of noncuddlers, however, was the same to the carpet and burlap fabrics.
Comparison of bone marrow-derived and mucosal mast cells in controlling intramacrophage Francisella tularensis replication.

Although the importance of mast cells (MCs) in response to allergens has been characterized extensively, the contribution of these cells in host defense against bacterial pathogens is not well understood. Previously, we have demonstrated that the release of interleukin-4 by bone marrow-derived MCs inhibits intramacrophage replication of Francisella tularensis live vaccine strain (LVS). Because pneumonic tularemia is one of the several manifestations of infection by Francisella, it is important to determine whether MCs present in mucosal tissues, i.e. the lung, exhibit similar effects on LVS replication. On the basis of this rationale, we phenotypically compared mucosal mast cells (MMCs) to traditional bone marrow-derived MCs. Both cell types exhibited similar levels of cell surface expression of fragment crystal epsilon receptor I (FceRI), mast/ stem cell growth factor receptor (c-Kit) and major histocompatibility complex I (MHCI), as well as patterns of granulation. MMCs exhibited a comparable, but somewhat greater uptake of fluorescent-labeled beads compared with MCs, suggesting an increased phagocytic ability. MCs and MMCs co-cultured with primary macrophages exhibited comparable significant decreases in LVS replication compared with macrophages cultured alone. Collectively, these results suggest that MMCs are phenotypically similar to MCs and appear equally effective in the control of intramacrophage F. tularensis LVS replication.
Heparan Sulfate-mediated Cell Aggregation SYNDECANS-1 AND −4 MEDIATE INTERCELLULAR ADHESION FOLLOWING THEIR TRANSFECTION INTO HUMAN B LYMPHOID CELLS

Because syndecans are present at sites of cell-cell contact in vivo it has been hypothesized that they play a role in mediating cell-cell adhesion. However, there has been no direct evidence to support this notion. To address this question, B lymphoid (ARH-77) cells were transfected with the cDNA for murine syndecan-1. Unlike the parental cells, the transfectants form large multicellular aggregates in suspension cultures and stain intensely for syndecan-1 at sites of cell-cell contact. Using rotation-mediated aggregation assays, we find that aggregation of syndecan-1-transfected cells is dependent on divalent cations and is inhibited by the following: (i) addition of heparin and heparin-like glycosaminoglycans, (ii) removal of heparan sulfate from the cell surface, or (iii) addition of exogenous purified syndecan-1. Mixing of syndecan-1-transfected and control-transfected cells results in aggregates containing both cell types indicating that aggregation occurs through a heterophilic adhesion mechanism in which heparan sulfate chains bind to a counter-receptor present on these cells. Importantly, syndecan-4-transfected cells also aggregate in a heparan sulfate-dependent manner, while in contrast, betaglycan-transfected cells aggregate poorly. Thus, syndecans may be important mediators of cell-cell adhesion, but this function may not be common to all transmembrane heparan sulfate-bearing proteoglycans.
A jiffy clock for the Apple IIc, II+, and IIe with a mouse

A “jiffy clock” is presented for the Apple lIc or other Apple II having Apple’s mouse card. The clock allows timing of events to tenths of a second, and is read from BASIC. A convenient elapsed timer function is provided as well.
Adult dogs receiving a rabies booster dose with a recombinant adenovirus expressing rabies virus glycoprotein develop high titers of neutralizing antibodies

Retired greyhound dogs, with low or absent antibody titers to rabies virus following previous vaccinations with commercially available vaccines, were immunized either subcutaneously or intramuscularly with a replication-defective recombinant adenovirus expressing the rabies virus glycoprotein termed Adrab.gp. Immunized animals developed high titers (geometric mean titers of 2630 and 5329) of viral neutralizing antibodies (VNA) against rabies virus by 10 days after vaccination. The antibody titers were even higher (geometric mean titers of 19349 and 122086) by 21 days after vaccination. The results indicate that the recombinant adenovirus expressing rabies virus glycoprotein is capable of inducing antibody immune responses in dogs and therefore may be developed as a rabies virus vaccine for dogs.
Occurrence and timing of childhood overweight and mortality: findings from the Third Harvard Growth Study.

Objective To assess the mortality experience of participants in the Third Harvard Growth Study (1922-1935) who provided ≥8 years of growth data. Study design A total of 1877 participants provided an average of 10.5 body mass index measurements between age 6 and 18 years. Based on these measurements, the participants were classified as ever overweight or ever >85th percentile for height in childhood. Age at peak height velocity was used to indicate timing of overweight relative to puberty. Relative risks of all-cause and cause-specific mortality according to measures of childhood growth were estimated using Cox proportional hazards survival analysis. Results For women, ever being overweight in childhood increased the risks of all-cause and breast cancer death; the risk of death from ischemic heart disease was increased in men. Men with a first incidence of overweight before puberty were significantly more likely to die from ischemic heart disease; women in the same category were more likely to die from all causes and from breast cancer. Conclusion We find evidence of long-term effects of having ever been overweight, with some evidence that incidence before puberty influences the pattern of risk.
An FPGA/SoC Approach to On-Board Data Processing Enabling New Mars Science with Smart Payloads

A proposed Mars Scout Mission known as MARVEL is vying for the 2011 launch opportunity. One of its primary instruments, MATMOS, will produce large volumes of data in short, 3-minute bursts during its on-orbit observation of sunrise and sunset. The remaining orbit time of 112 minutes is available for on-board data processing to reduce data volume prior to downlink. This data processing relies heavily on floating-point FFTs. The Xilinx Virtex-II Pro FPGA was evaluated in a previous research task, but could not meet the performance requirements, even with an integrated soft-core floating-point unit (FPU). The next-generation Virtex-4 FPGA contains an auxiliary processor unit (APU) that provides a flexible high bandwidth interface for fabric co-processor modules (FCM) to the PowerPC405 core. In this paper we show that coupling the FPU FCM with the APU provides sufficient computation power to meet MATMOS's data processing requirements when implemented in a multi-processor, dual-FPGA system.
Versatile fluorescence probes of protein kinase activity.

We introduce a versatile fluorescent peptide reporter of protein kinase activity. The probe can be modified to target a desired kinase by changing the kinase recognition motif in the peptide sequence. The reporter motif contains the Sox amino acid, which generates a fluorescence signal when bound to Mg2+ present in the reaction mixture. The phosphorylated peptide exhibits a much greater affinity for Mg2+ than its unphosphorylated analogue and, thus, a greater fluorescence intensity. Product formation during phosphorylation by the kinase is easily followed by the increase in fluorescence intensity over time. These probes exhibit a 3−5-fold increase in fluorescence intensity upon phosphorylation, the magnitude of which depends on the substrate. Peptides containing the reporter functionality are phosphorylated on serine by Protein Kinase C and cAMP-dependent protein kinase and are shown to be good substrates for these enzymes. The principle of this design extends to peptides phosphorylated on threonine and t...
A novel assay to assess the effectiveness of antiangiogenic drugs in human breast cancer.

Background Many cytotoxic drugs maintain antiangiogenic properties, but there are no human, tumor-based assays to evaluate their antiangiogenic potential. We used a fibrin–thrombin clot-based angiogenesis model to evaluate the angiogenic response of human breast cancer to various cytotoxic agents commonly used in its treatment.
Predicting the in Vivo Mechanism of Action for Drug Leads Using NMR Metabolomics

New strategies are needed to circumvent increasing outbreaks of resistant strains of pathogens and to expand the dwindling supply of effective antimicrobials. A common impediment to drug development is the lack of an easy approach to determine the in vivo mechanism of action and efficacy of novel drug leads. Toward this end, we describe an unbiased approach to predict in vivo mechanisms of action from NMR metabolomics data. Mycobacterium smegmatis, a non-pathogenic model organism for Mycobacterium tuberculosis, was treated with 12 known drugs and 3 chemical leads identified from a cell-based assay. NMR analysis of drug-induced changes to the M. smegmatis metabolome resulted in distinct clustering patterns correlating with in vivo drug activity. The clustering of novel chemical leads relative to known drugs provides a mean to identify a protein target or predict in vivo activity.
781 INCIDENCE AND SIGNIFICANCE OF DYSTONIA IN THE LOW BIRTHWEIGHT INFANT

Dystonia (DT) is a common problem in the low birthweight infant. In order to investigate the incidence of DT and the relationship between persistent DT and developmental delay, we performed neuromuscular and developmental evaluations on 132 infants with BW ≤1750 g (45 have reached their 3 yr exam, 33 have reached 2 yr, 35 have reached 18 mos. and 19 have reached 12 mos.). Hypertonicity is the most common type of DT with a peak incidence of 83% at 6 months corrected age (CA). In contrast, hypotonicity is relatively uncommon, with a peak incidence of 18% at 3 mos. CA. Resolution of DT occurs steadily; at their latest exam, 70% of 18 mo. olds, 86% of 24 mos. olds and 92% of 3 year olds had normal tone. Developmental scores of the normal (No DT) and the dystonic members of the 18, 24 and 36 mos. cohorts were compared. The results of developmental testing (mean ± SD) are summarized below. Conclusions: Dystonia in most preterm infants less than 2 yr CA should be considered a common but transient problem. Persistent dystonia, however, occurs in a small number of infants and should be viewed with concern. The developmental progress of those infants should be carefully assessed.
A general expression for the thermoelectric power

Abstract By writing the thermopower as an integral over one electron energy states S = -( k e ) ʃ (E − E F ) (kT) [ σ(E) σ ] d E , with the conductivity σ = ʃ σ(E) d E , one can derive the various expressions proposed for the thermopower in non-crystalline metals and semiconductors. The above expression appears to have general validity when correlation effects are neglected. EF is the Fermi energy.