cssi/SciSciGPT-SciSciNet huggingface dataset:
Matching authors and readers of scientific papers

Summary-A novel service is proposed to help authors of scientific papers to select journals to which to submit their manuscripts. The aim of the service is to optimize the common interests of authors, readers/users, and science, by providing the authors with a tool for reaching those readers who can most benefit from the news of their accomplishments. The five basic factors which intervene in the choice of a journal are analyzed: relevance, acceptance rate, circulation, prestige and publication lag. With the help of a mathematical model, we show how these five variables can be used in a plausible decision procedure leading to the selection of journals suitable for the publication of given papers. WHEN a scientist submits an article for publication, the choice of a suitable journal is often guided by self-interest. It helps the scientist's career if the results of his work are published in a journal representative of his discipline. It helps most if the journal is the most prestigious in the subject area, with the largest circulation, and with the shortest publication lag. If an author chooses wisely where to publish, this may also serve the interests of the potential readers of his papers. Their concern is to gain valuable information with the minimum possible delay. There is, therefore, a convergence of interests on the part of authors and readers that the proper audience for the reporting of scientific investigations be reached. The healthy growth of the scientific enterpriseand also of enterprises based on the utilization of knowledge-is dependent on the matching of these complementary interests. Some scientists find it difficult to select wisely the journals to which to submit their papers. Scientists who are just starting their careers, who do not have experienced colleagues to advise them, and who do not yet belong to any "invisible college", may experience difficulties. So may scientists who have just switched from one specialty to another, or people who work in interdisciplinary fields or in fields without a welldeveloped "paradigm". Almost any scientist, even the most experienced, has probably felt, at one time or another, that he had submitted some of his papers to the wrong journal or addressed it to the wrong audience. A good service to advise an author on how to reach the readers who can benefit most from news of his accomplishments would be helpful to him, to his potential readers, and to science. To justify such service, one should be able to show that it would fill a real, important and sizeable need, and that it would do as well or better than the advice offered by experienced professional colleagues. Some scientific foundation is required to design such a service with assurance that it will be helpful. Prior work on the sociology of publishing/I-3], on the psychology of authorship/4-5], and on the patterns of communication in a scientific community [6-12] provides the starting point of this study. The "Bradford law" [13-14] states
Computing with Emergence

The concept of emergence has its roots in 19th-century philosophy. Today it is central to many computational systems which retain the hallmarks of emergence laid out much earlier. The role of emergence in creative design and its unique embodiment in shape grammars have been emphasized by March, Stiny, and others. Shape grammars generate emergent shapes—shapes not predefined in a grammar. Emergent shapes are not only the output of a shape grammar computation; they can be the input for further computation. The history of emergence and its characterization in shape grammars are discussed here. Different sorts of shape emergence in grammars are then distinguished: anticipated, possible, and unanticipated. Unanticipated emergent shapes are shapes not premeditated by the author or user of a grammar. Generally, unanticipated shapes require on-the-spot definitions of rules to compute with them. However, for some interesting design problems, it is possible to know in advance what to do with unanticipated shapes, a...
Data frequency and the number of factors in stock returns

Abstract Determining the number of factors that explain stock returns plays an important role in empirical tests of the Arbitrage Pricing Theory. This paper examines the sensitivity of the number of factors to different data frequencies using daily, weekly, and monthly returns. The empirical results are consistent with the null hypothesis that the number of factors is the same for different data frequencies once daily returns are adjusted for nonsynchronous trading. The evidence also identifies only one or two factors.
Transcutaneous bilirubinometry. III. Dermal bilirubin kinetics under green and blue light phototherapy.

• Using the transcutaneous bilirubinometer, we studied the response of cutaneous bilirubin to different colors of light during phototherapy. Three groups of ten infants were exposed to blue, green, and blue-green lights at a mean postnatal age ranging from 50 to 77 hours. Patched areas served as controls. Every 15 minutes during four hours of phototherapy, we obtained simultaneous measurements from exposed and covered areas. After the onset of phototherapy, transcutaneous bilirubinometer values from the covered areas in all groups remained stable. The overall rate of bleaching was lowest in the green light group and highest in the blue-green combination group. In this group of infants, green light appeared to enhance the effectiveness of blue light in reducing dermal bilirubin concentrations as measured by the transcutaneous bilirubinometer. ( AJDC 1986;140:994-997)
Prostacyclin potentiates 13-azaprostanoic acid-induced platelet deaggregation

Abstract The specific thromboxane A2/prostaglandin H2 (TXA2/PGH2) antagonist 13-azaprostanoic acid (13-APA) reverses platelet aggregation stimulated by TXA2/PGH2 and the prostaglandin endoperoxide analog U46619. The present report demonstrates that the deaggregatory properties of 13-APA are potentiated by prostacyclin (PGI2). Human platelet-rich plasma was aggregated with U46619. Deaggregation was induced 2 min subsequent to the addition of the aggregating agent. Concentrations of 13-APA or PGI2 which induced 20 percent deaggregation were determined. Simultaneous addition of half of these concentrations resulted in 60 percent deaggregation, demonstrating that the observed response was supraadditive. Measurement of cyclic adenosine 3′:5′ monophosphate (cAMP) in resting or deaggregating platelets demonstrated that 13-APA itself did not stimulate cAMP production nor did 13-APA facilitate PGI2-induced increases in cAMP. In separate studies PGI2 and 13-APA were added to PRP prior to the induction of aggregation by U46619. Under these conditions, additive inhibition of aggregation was observed. Thus, it is clear that the pharmacological interaction between PGI2 and 13-APA depends upon the relative state of platelet activation.
Altruism from the house: the impact of home equity on charitable giving

This paper exploits the dramatic increase in house prices in early 2000 and the panel nature of the data to investigate the effect of home equity on charitable giving. Using the Panel Study of Income Dynamics from 2001 to 2007, we find that a 10% increase in home equity increases a household’s contributions to charity by almost 1%. This is in contrast to the effect of non-housing wealth, which we estimate to be one tenth the magnitude. Our results are consistent with the consumption literature that reports a distinct effect of housing wealth that is significantly larger than that of financial wealth.
Mandated Evaluation in Community Mental Health Centers Framework for a New Policy

Experience with federally mandated Community Mental Health Center (CMHC) program evaluation (P.L. 94-63) is examined in terms of three issues: (1) the purposes which evaluation serves; (2) the values about evaluation held by key participants; and (3) limitations in both evaluation technology and CMHC context and resources. Eight generic principles for government role in evaluation are derivedfrom this experience. The principles suggest two different roles—accountability to the public and program amelioration. Government requirements should be concerned solely with the former. Specific recommendations for implementing these two roles are given.
Cytopathogenicity of Mycoplasma fermentans (Including Strain Incognitus)

Mycoplasma fermentans strain incognitus, an organism recently identified in tissues of patients with AIDS and in tissues of otherwise healthy adults with an acute fatal respiratory disease, was evaluated for cytopathogenicity for tracheal tissue in vivo and in vitro. In this study, the organism produced a chronic infection of the lower respiratory tract in LEW rats following intranasal inoculation and induced both ciliostasis and cytopathology in experimentally infected tracheal explants from rats. The time of onset of ciliostasis, type of cytopathogenicity, and localization of organism in strain incognitus were different from those in other strains of M. fermentans as well as other species of mycoplasmas isolated from humans. The results strongly support, but do not prove, that M. fermentans strain incognitus is an unusually invasive mycoplasma, as it was the only strain found within respiratory epithelial cells both in vivo and in vitro. Detection of the organism within the lamina propria also supported the organism's invasive potential. Further study of both the in vivo and in vitro models should provide insights into this potentially unique mycoplasma-host relationship.
Stochastic Assessment of Long-Term Impacts of Phosphorus Management Options on Sustainability with and without Climate Change

AbstractIn this study, a combination of two modified versions of the SWAT 2005 model are used to estimate the impact of several best management practices on phosphorus loading to the Cannonsville reservoir in upstate New York as a function of variable weather and climate. The management scenarios in this study include a base case scenario in which management practices are not changed and three other scenarios in which new practices are implemented to reduce the amount of phosphorus applied to the watershed. The long-term impacts of these scenarios are investigated using historical data and stochastically generated weather data that incorporate projected climate change. The projected changed climate data are used to investigate the impact of a changed climate on the nutrient loading and the effectiveness of the three management practices on reducing nutrient loading to the reservoir. The methodology used here can be helpful to other watersheds as well to assess long term response to best management practic...
An Experimental and Computational Study of the Electron Affinity of Boron Oxide

The 351 nm photoelectron spectrum of BO- is reported. Detachment to form 2∑+ BO is observed, and the electron affinity of BO is determined to be 2.508 ± 0.008 eV. From the photoelectron spectra, vibrational frequencies of 1875 ± 30 cm-1 and 1665 ± 30 cm-1 are obtained for X BO and BO-, respectively, and the bond length in BO- is found to be 1.236 ± 0.010 A. The measured EA is used to derive a bond energy in BO- of 9.39 eV. High-level molecular orbital calculations of the electron affinity are reported. The results from multiconfigurational SCF, G2, and complete basis set calculations are in good agreement with experiment.
Sensitivity of thermomechanical response to thermal boundary conditions and material constants

Abstract Forced vibrations of a thermoviscoelastic material give rise to nonlinear coupling between thermal and mechanical responses. In particular, the response of a rod of solid rocket propellant to axial vibrations includes several narrow frequency ranges characterized by rapid or even discontinuous increases in thermomechanical response. In this paper, the sensitivity of these critical frequency ranges to boundary condition modeling and to small changes in constitutive properties and ambient conditions is studied. It is found that the solution is somewhat sensitive to the temperature dependence in the thermoviscoelastic material law, but far more sensitive to the type of thermal boundary conditions imposed upon the problem.
Dietary influences on production, stoichiometry and decomposition of particulate wastes from shredders

Summary Aquatic shredders produce large quantities of fine particulate organic matter (FPOM) as fragments and egesta, but the significance of shredder FPOM as a pathway of consumer-mediated nutrient transformation remains understudied. We fed the stream shredders Pycnopsyche lepida, Lepidostoma sp. and Tipula abdominalis oak or maple litter conditioned under contrasting phosphorus concentrations to produce gradients in dietary carbon:phosphorus (C:P) and carbon:nitrogen (C:N) content (range = 850–4480 and 30–49 by moles, respectively). We measured total production and stoichiometry of FPOM to estimate particulate N and P release rates, compared resultant rates to those of P excretion and measured microbial decomposition of FPOM. FPOM production was lowest for Lepidostoma and higher for Tipula and Pycnopsyche; FPOM production by Tipula increased on higher-nutrient diets. The C:P, C:N and N:P of FPOM from Pycnopsyche and Tipula often diverged from diet stoichiometry depending on litter type, and rates of particulate N and P release by shredders were greater with increasing nutrient content of the diet. Shredders fed high-nutrient diets produced FPOM with greater microbial decomposition rates, although these trends differed between litter types. Bottom-up changes in litter type and nutrient content may modify production, stoichiometry and decomposition of FPOM from shredders, and shredder-mediated nutrient transformations may differ across shredder species.
EFFECT OF OVINE INTERSTITIAL CELL-STIMULATING HORMONE ON SPERMATOGENESIS IN THE HYPOPHYSECTOMIZED MOUSE

The effect of interstitial cell-stimulating hormone (ICSH) on the maintenance of spermatogenesis in the C3H mouse when administered immediately after hypophysectomy, and on the repair of the seminiferous tubules when administered 2 weeks after the operation, has been investigated. The hormone was injected for a period of 15 days; partial maintenance was obtained with a daily dose of 0.001 mg. and complete maintenance with 0.010 mg. With submaintenance doses, the higher the dose of the hormone the more mature were the germ cells observed in the tubules. When injections of ICSH were begun 2 weeks after hypophysectomy, repair of the germinal epithelium was obtained; degeneration and desquamation of the primary spermatocytes ceased, spermatogenic development in many tubules advanced to the spermatid stage, and the spermatozoa were observed in the epididymides in 50% of the injected animals. Interstitial cells, normal in appearance, were abundant. Testosterone propionate, 2.5 mg. per day, maintained spermatoge...
Recent innovations and refinements in reconstructive surgery

The dermatologic surgeon is continually faced with challenging cases that require innovative techniques for reconstruction. This review provides a brief description of a variety of repairs that the author uses in his practice. Some of these reconstructions are more established techniques, while others are described more recently. The author also presents refinements and variations of some of these repairs. Initially, the review will focus on flaps that he uses predominantly for nasal reconstruction, including the paramedian forehead flap, melolabial interpolation flap and turnover nasolabial flap. Other flaps, including the Cupid’s bow mucosal advancement flap, dog-ear rotation flap, double O–Z flap and bilateral island pedicle flap are also discussed. The last portion of the article focuses on grafts: drumhead graft, clavicular graft and porcine heterograft. This article cannot cover the complete spectrum of reconstructive options but focuses on repairs the author has felt to be useful in his institution.
Enhancement of American chestnut somatic seedling production

Somatic embryogenesis holds promise for mass propagation of American chestnut trees bred or genetically engineered for resistance to chestnut blight. However, low germination frequency of chestnut somatic embryos has limited somatic seedling production for this forest tree. We tested the effects of culture regime (semi-solid versus liquid), cold treatment, AC and somatic embryo morphology (i.e., cotyledon number) on germination and conversion of the somatic embryos. Cold treatment for 12 weeks was critical for conversion of chestnut somatic embryos to somatic seedlings, raising conversion frequencies for one line to 47%, compared to 7% with no cold treatment. AC improved germination and conversion frequency for one line to 77% and 59%, respectively, and kept roots from darkening. For two lines that produced embryos with one, two or three-plus cotyledons, cotyledon number did not affect germination or conversion frequency. We also established embryogenic American chestnut suspension cultures and adapted a fractionation/plating system that allowed us to produce populations of relatively synchronous somatic embryos for multiple lines. Embryos derived from suspension cultures of two lines tested had higher conversion frequencies (46% and 48%) than those from cultures maintained on semi-solid medium (7% and 30%). The improvements in manipulation of American chestnut embryogenic cultures described in this study have allowed over a 100-fold increase in somatic seedling production efficiency over what we reported previously and thus constitute a substantial advance toward the application of somatic embryogenesis for mass clonal propagation of the tree.
A mode-hop-free tunable single-longitudinal-mode Nd:YVO4 laser with 25W of power at 1064nm

It is well known that intra-cavity second-harmonic generation (SHG) suppresses mode hopping in solid-state resonators producing single-longitudinal-mode (SLM) output at the second-harmonic frequency (SHF). A simple extension of this concept is to suppress mode hopping in a resonator producing SLM output at the fundamental frequency (through an output-coupling mirror) by inserting an intra-cavity SHG crystal that converts a fraction of the intra-cavity power to the SHF. The beam at the SHF can either be dumped or is available as a second output beam. When combined with a PZT-actuated mirror, it is possible to continuously tune the frequency of the fundamental beam through a significant fraction of the gain bandwidth without mode hopping. SHG also suppresses mode hopping during warm up and during pumppower changes. These features were demonstrated in a unidirectional Nd:YVO 4 ring resonator producing an output beam greater than 25W at 1064nm while generating a few Watts at the SHF of 532nm. Mode hopping is substantially reduced during warm up and mode-hop-free operation can be sustained over many hours. Frequency tuning over several GHz was demonstrated and larger tuning ranges are possible. The PZT-actuated mirror can be used to eliminate frequency drift, to stabilize the output to a frequency standard (such as an atomic-absorption line), or to mitigate cavitylength changes due to acoustic noise.
Two classes of pyrethroid action in the cockroach

Abstract Pyrethroids are divided into two classes (Types I and II) based on their effects on the cercal sensory nerves recorded in vivo and in vitro and on the symptomology they produce in dosed cockroaches, Periplaneta americana . Type I compounds include pyrethrins, S -bioallethrin, [1 R,cis ]resmethrin, kadethrin, the 1 R,trans and 1 R,cis isomers of tetramethrin, phenothrin, and permethrin, and an oxime O -phenoxybenzyl ether. Electrophysiological recordings from dosed individuals reveal trains of cercal sensory spikes and sometimes also spike trains from the cercal motor nerves and in the CNS. Low concentrations of these pyrethroids act in vitro to induce repetitive firing in a cercal sensory nerve following a single electrical stimulus. This in vitro measurement, standardized for evaluating structure-activity relationships, shows that only 1 R , insecticidal isomers are highly effective neurotoxins. The most potent compounds on the isolated nerve are [1 R,trans ]- and [1 R,cis ]tetramethrin, each active at 3 × 10 −13 M . The poisoning symptoms of Type I compounds are restlessness, incoordination, hyperactivity, prostration, and paralysis. Type II compounds include [1 R,cis ,α S ]- and [1 R,trans ,α S ]cypermethrin, deltamethrin, and [ S,S ]fenvalerate. These α-cyanophenoxybenzyl pyrethroids do not induce repetitive firing in the cercal sensory nerves either in vivo or in vitro ; moreover, they cause different symptoms, including a pronounced convulsive phase. Two other pyrethroids with an α-cyano substituent, i.e., fenpropathrin and an oxime O -α-cyanophenoxybenzyl ether, are classified as Type I based on their action on a cercal sensory nerve but the symptoms with these compounds resemble Type II. The two classes of pyrethroid action evident with the cockroach are discussed relative to their neurophysiological effects and symptomology in other organisms.
Shot noise limited optical measurements at baseband with noisy lasers (proceedings Only)

ABSTRACTThis paper describes a simple, all-electronic noise cancellation scheme which allows wideband, shot noise limited optical measurements at baseband, with noisy lasers, in many kinds of optical systems. With this system, it is usually possible toachieve the performance of a complex heterodyne system with a much simpler homodyne approach. Although it is similarto earlier differential and ratiometric techniques, its noise cancellation performance is much better, and it is highly effec-tive at modulation frequencies up to tens of megahertz. The basic idea is to subtract photocurrents directly, under feed-back control, to cancel excess noise (i.e. noise above the shot noise level) and spurious modulation of the beam. A sampleis split off from the beam at the laser and detected with a photodiode similar to the main detector at the system output.Most optical systems and detectors have very wide temporal bandwidths and excellent linearity; thus at all frequenciesof interest, the sample photocurrent has exactly the same instantaneous fractional excess noise fluctuations as the laserbeam itself, with no differential gain or phase. If a fraction of the sample photocurrent is subtracted from the main de-tector output, with feedback controlling the division ratio to keep the DC component of the result at zero, the excess noisecancels identically. The actual noise cancellation bandwidth is very wide, and does not depend on the feedback band-width, only on that of the differential bipolar transistor current divider. Two noise-cancelled outputs are available, onea high-pass filtered version of the signal imparted by the optical system, the other, a low-pass filtered voltage related tothe log ratio of the intensities of the two optical beams. The noise floors of the outputs depend only on the shot noiseof the signal beam. Measurements using a prototype of the device are presented which demonstrate this performance.2. INTRODUCTIONExcess noise, spurious modulation, and power drift in lasers are common problems in optical measurements. In gaslasers, the noise levels can easily reach 50 dB above shot noise, even quite far from DC. Since the noise and spurious
Inhibition of phospholipase C by phosphonate analogs of glycerophosphatides

Abstract 1. 1. The inhibition of Clostridium perfringens phospholipase C (phosphatidyl-choline cholinephosphohydrolase, EC 3.1.4.3) hydrolysis of lecithin by eight synthetic phosphonate-containing analogs of lecithin, cephalin, and phosphatidic acid was studied. There was a wide variation among the inhibitory activities; the lecithin analogs as a group were the most active. 2. 2. The two most effective inhibitors found were 3,4-dioctadecoxybutylphos-phonylcholine and 2-hexadecoxy-3-octadecoxypropylphosphonylcholine. Except for a lag phase in the inhibited reactions, both of these substances gave relatively simple kinetics, including ordinary competitive inhibition of the enzyme as the inhibition mode. 3. 3. These two lecithin analogs appear to exert little effect on the ζ-potential of lecithin particles. 4. 4. Interpretations of these studies and potential utility of the inhibitors are discussed.
Microphase Separation in Charged Diblock Copolymers: The Weak Segregation Limit

The onset of phase separation in diblock copolymers made of neutral and weakly charged blocks is studied in the presence of arbitrary amounts of added salt is studied. The strong dependence of the critical interaction parameter (and hence of the spinodal temperature or the critical chain length) and of the wavelength of microphase separation on the chain charge and on the salt concentrations suggests that the stability and the morphology of the resulting phases can be controlled and fine-tuned by adjusting these parameters
Deduction in non-Horn databases

The class of non-Horn, function-free databases is investigated and several aspects of the problem of using theorem proving techniques for such databases are considered. This includes exploring the treatment of negative information and extending the existing method, suggested by Minker, to accept non-unit negative clauses. It is shown that the algorithms based on the existing methods for the treatment of negative information can be highly inefficient. An alternative approach is suggested and a simpler algorithm based on it is given. The problems associated with query answering in non-Horn databases are addressed and compared with those for the Horn case. It is shown that the query evaluation process can be computationaly difficult in the general case. Conditions under which the process is simplified are discussed. The topic of non-Horn general laws is considered and some guidelines are suggested to divide such laws into derivation rules and integrity constraints. The effect of such a division on the query evaluation process is discussed.
Lipid Components of the Fat-Globule Membrane

Summary Lipid components were extracted from fat-globule membranes prepared by two procedures. One method (Scheme I) started with cold, pooled milk, whereas in the other procedure (Scheme II) freshly drawn, uncooled milk served as the source. The lipids obtained were resolved by gradient elution from a silicic acid chromatographic column. The following lipid classes were identified as components of the fat-globule membrane: carotenoids, a squalene-like compound, cholesterol esters, cholesterol, a unique triglyceride mixture similar to the high-melting glyceride fraction, mono-diglycerides, phospholipids and, from some preparations, unesterified fatty acids. The minor differences in composition between the membrane lipids reflected the age of the milk and the method of preparation. Membranes isolated from the pooled milk by Scheme I contained lower concentrations of phospholipids and associated proteins. Carotenoids, cholesterol esters, and the squalene-like component were removed from the membranes by washing with ethyl ether.
Laser velocimeter measurements of the flow downstream of the Space Shuttle Main Engine high pressure oxidizer turbopump first-stage turbine nozzle

A laser two-focus velocimeter was used in an open-loop water test facility in order to map the flowfield downstream of the SSME's high-pressure oxidizer turbopump first-stage turbine nozzle; attention was given to the effects of the upstream strut-downstream nozzle configuration on the flow at the rotor inlet, in order to estimate dynamic loads on the first-stage rotor blades. Velocity and flow angles were plotted as a function of circumferential position, and were found to clearly display the periodic behavior of the wake flow field. The influence of the upstream centerbody-supporting struts on the vane nozzle wake pattern was evident.
Critical Periods of Sensitivity of Sexually Dimorphic Spinal Nuclei to Prenatal Testosterone Exposure in Female Rats

Male rats normally have more neurons than do females in two nuclei of the lumbar spinal cord, the spinal nucleus of the bulbocavernosus (SNB) and the dorsolateral nucleus (DLN). Female rats exposed to testosterone propionate (TP) on the 2 days of gestation (Days 18 and 19) when males normally experience a surge in plasma testosterone showed a maximal increase in both SNB and DLN neuronal number. TP exposure just prior to, or following, Days 18 and 19 led to smaller increments. Administration of a small (5 microg) dose of TP after birth, while having no effect by itself, synergized with prenatal TP to enhance the number of SNB neurons. DLN neurons were less responsive to postnatal TP. The somal and nuclear size of SNB, but not DLN, neurons was increased by perinatal TP. Paradoxically, the number of DLN neurons with large somas (1358 microm2 or larger) was reduced by perinatal TP, a finding congruent with a previous report that females and feminized males have more of these large DLN neurons than control males. Our data suggest an exquisite sensitivity of the developing spinal nuclei to the timing of hormonal surges normally found in fetal males. Exposure to androgens during a brief prenatal period is needed to assure responsiveness to the low amounts of androgen circulating during neonatal ontogeny, when the process of sexual differentiation is completed.
Processing Internet Communications: A Motivation, Opportunity and Ability Framework

Abstract Despite the rapid growth of the Internet as a vehicle for communication and commerce, substantive theory to guide Web-based marketing communications is still in its infancy. Combining the distinctive characteristics of the Internet with recent models and research findings regarding information processing, this paper proposes a framework for understanding consumer response to Web-based communications. Consideration of Internet communication options (advertisements, Web sites, viral messaging), message characteristics (attention devices, encoding variability, framing, mood tone) and individual-difference moderators (involvement, cognitive/affective motivations, gender, context) leads to propositions regarding consumer motivation, opportunity and ability to process.
Influence of channel position on sample confinement in two-dimensional planar microfluidic devices

We report enhanced sample confinement on microfluidic devices using a combination of electrokinetic flow from adjacent control channels and electric field shaping with an array of channels perpendicular to the sample stream. The basic device design consisted of a single first dimension (1D) channel, intersecting an array of 32 or 96 parallel second dimension (2D) channels. To minimize sample dispersion and leakage into the parallel channels as the sample traversed the sample transfer region, control channels were placed to the left and right of the 1D and waste channels. The electrokinetic flow from the control channels confined the sample stream and acted as a buffer between the sample stream and the 2D channels. To further enhance sample confinement, the electric field was shaped parallel to the sample stream by placing the channel array in close proximity to the sample transfer region. Using COMSOL Multiphysics, initial work focused on simulating the electric fields and fluid flows in various device geometries, and the results guided device design. Following the design phase, we fabricated devices with 40, 80, and 120 µm wide control channels and evaluated the sample stream width as a function of the electric field strength ratio in the control and 1D channels (EC/E1D). For the 32 channel design, the 40 and 80 µm wide control channels produced the most effective sample confinement with stream widths as narrow as 75 µm, and for the 96 channel design, all three control channel widths generated comparable sample stream widths. Comparison of the 32 and 96 channel designs showed sample confinement scaled easily with the length of the sample transfer region.
Neurocomputational models of basal ganglia function in learning, memory and choice

The basal ganglia (BG) are critical for the coordination of several motor, cognitive, and emotional functions and become dysfunctional in several pathological states ranging from Parkinson's disease to Schizophrenia. Here we review principles developed within a neurocomputational framework of BG and related circuitry which provide insights into their functional roles in behavior. We focus on two classes of models: those that incorporate aspects of biological realism and constrained by functional principles, and more abstract mathematical models focusing on the higher level computational goals of the BG. While the former are arguably more "realistic", the latter have a complementary advantage in being able to describe functional principles of how the system works in a relatively simple set of equations, but are less suited to making specific hypotheses about the roles of specific nuclei and neurophysiological processes. We review the basic architecture and assumptions of these models, their relevance to our understanding of the neurobiological and cognitive functions of the BG, and provide an update on the potential roles of biological details not explicitly incorporated in existing models. Empirical studies ranging from those in transgenic mice to dopaminergic manipulation, deep brain stimulation, and genetics in humans largely support model predictions and provide the basis for further refinement. Finally, we discuss possible future directions and possible ways to integrate different types of models.
Long-term stapedectomy results with the McGee stapes prosthesis.

Objective To report long-term follow up on patients undergoing stapedectomy with the McGee stapes prosthesis. Study Design A retrospective case series. Methods Charts recording 170 stapedectomies (120 primary and 50 revision stapedectomies) from 1989 to 1999 were analyzed, and audiometric data and the findings at repeat exploration reported. Results Over a 10-year period, 11.2% of patients had failure of their initial air-bone gap closure with the McGee piston. Seventy-seven percent (in 10 of 13 patients) of McGee pistons that failed were found to have the platinum ribbon displaced laterally from the incus and the piston pushed out of the stapedotomy. The failure rate was not significantly different (P = .72) from that in our patients who underwent placement of a Robinson cup prosthesis (9.5%), but the pattern of displacement was unique. Failures occurred earlier with the McGee piston (average time to failure of 2.5 y) than with the Robinson cup (average time to failure of 8.6 y). Conclusion The McGee piston was found to have a unique pattern of dislocation that is likely related to the malleable nature of the platinum ribbon and loosening of the crimped “shepherd's crook” over time.
Proofs and refutations in the undergraduate mathematics classroom

In his 1976 book, Proofs and Refutations, Lakatos presents a collection of case studies to illustrate methods of mathematical discovery in the history of mathematics. In this paper, we reframe these methods in ways that we have found make them more amenable for use as a framework for research on learning and teaching mathematics. We present an episode from an undergraduate abstract algebra classroom to illustrate the guided reinvention of mathematics through processes that strongly parallel those described by Lakatos. Our analysis suggests that the constructs described by Lakatos can provide a useful framework for making sense of the mathematical activity in classrooms where students are actively engaged in the development of mathematical ideas and provide design heuristics for instructional approaches that support the learning of mathematics through the process of guided reinvention.
Results of multifield conformal radiation therapy of nonsmall-cell lung carcinoma using multileaf collimation beams.

A five-field conformal technique with three-dimensional radiation therapy treatment planning (3-DRTP) has been shown to permit better definition of the target volume for lung cancer, while minimizing the normal tissue volume receiving greater than 50% of the target dose. In an initial study to confirm the safety of conventional doses, we used the five-field conformal 3-DRTP technique. We then used the technique in a second study, enhancing the therapeutic index in a series of 42 patients, as well as to evaluate feasibility, survival outcome, and treatment toxicity. Forty-two consecutive patients with nonsmall-cell lung carcinoma (NSCLC) were evaluated during the years 1993–1997. The median age was 60 years (range 34–80). The median radiation therapy (RT) dose to the gross tumor volume was 6,300 cGy (range 5,000–6,840 cGy) delivered over 6 to 6.5 weeks in 180–275 cGy daily fractions, 5 days per week. There were three patients who received a split course treatment of 5,500 cGy in 20 fractions, delivering 275 cGy daily with a 2-week break built into the treatment course after 10 fractions. The stages of disease were II in 2%, IIIA in 40%, IIIB in 42.9%, and recurrent disease in 14.3% of the patients. The mean tumor volume was 324.14 cc (range 88.3–773.7 cc); 57.1% of the patients received combined chemoradiotherapy, while the others were treated with radiation therapy alone. Of the 42 patients, 7 were excluded from the final analysis because of diagnosis of distant metastasis during treatment. Two of the patients had their histology reinterpreted as being other than NSCLC, 2 patients did not complete RT at the time of analysis, and 1 patient voluntarily discontinued treatment because of progressive deterioration. Median follow-up was 11.2 months (range 3–32.5 months). Survival for patients with Stage III disease was 70.2% at 1 year and 51.5% at 2 years, with median survival not yet reached. Local control for the entire series was 23.3 ± 11.4% at 2 years. However, for Stage III patients, local control was 50% at 1 year and 30% at 2 years. Patients who received concurrent chemotherapy had significantly improved survival (P = 0.002) and local control (P = 0.004), compared with RT alone. Late esophageal toxicity of ≥Grade 3 occurred in 14.1 ± 9.3% of patients (3 of 20) receiving combined chemoradiotherapy, but in none of the 15 patients treated with RT alone. Pulmonary toxicity limited to Grades 1–2 occurred in 6.8% of the patients, and none developed ≥Grade 3 pulmonary toxicity. Patients with locally advanced NSCLC, who commonly have tumor volumes in excess of 200 cc, present a challenge for adequate dose delivery without significant toxicity. Our five-field conformal 3-DRTP technique, which incorporates treatment planning by dose/volume histogram (DVH) was associated with minimal toxicity and may facilitate dose escalation to the gross tumor. Radiat. Oncol. Invest. 7:297–308, 1999. © 1999 Wiley-Liss, Inc.
Nifedipine‐induced gingival overgrowth

Abstract A review of the literature reveals little evidence that controlling plaque reduces and controls nifedipine-induced gingival overgrowth. The case presented suggests that significant reduction and control of nifedipine-induced gingival overgrowth can be achieved by thorough scaling and root planing along with meticulous plaque control.
Information Use by PhD Students in Agriculture and Biology: A Dissertation Citation Analysis

This article reports the findings of a study conducted to examine the types of information used by graduate students in the fields of biological and agricultural sciences at Iowa State University (ISU). The citations of doctoral dissertations submitted in nine agriculture and biological science subject fields (crop production and physiology; molecular, cellular, and developmental biology; entomology; genetics; microbiology; plant breeding; plant pathology; plant physiology; and soil science) at ISU from 1997–2006 were analyzed. The article discusses the types and ages of resources cited in the different subject fields studied. The most cited journals in each discipline were identified, and the journal title dispersion was examined.
High-content screening for compounds that affect mtDNA-encoded protein levels in eukaryotic cells

Compounds that interfere with the synthesis of either mitochondrial DNA or mtDNA-encoded proteins reduce the levels of 13 proteins essential for oxidative phosphorylation, leading to a decrease in mitochondrial adenosine triphosphate (ATP) production. Toxicity caused by these compounds is seldom identified in 24- to 72-h cytotoxicity assays due to the low turnover rates of both mtDNA and mtDNA-encoded proteins. To address this problem, the authors developed a 96-well format, high-content screening (HCS) assay that measures, in eukaryotic cells, the level of Complex IV-subunit 1, an mtDNA-encoded protein synthesized on mitochondrial ribosomes, and the level of Complex V-alpha subunit, a nuclear DNA-encoded protein synthesized on cytosolic ribosomes. The effect of several antibiotics and antiretrovirals on these 2 proteins was assessed, in transformed human liver epithelial cells, 6 days after compound treatment. The results confirmed effects of drugs known to reduce mtDNA-encoded protein levels and also revealed novel information showing that several fluoroquinolones and a macrolide, josamycin, impaired expression of mtDNA-encoded proteins. The HCS assay was robust with an average Z' factor of 0.62. The assay enables large-scale screening of compounds to identify those that potentially affect mtDNA-encoded protein levels and can be implemented within a screening paradigm to minimize compound attrition.
Cascade analysis of power distribution in a multilayered dielectric/frequency selective surface system

The scattering matrix approach is used to treat the problem of an FSS (frequency selective surface) in a multilayered dielectric environment. The i/sup th/ layer is an infinite FSS, whereas the others are dielectric slabs (possibly lossy). The problem is to determine the amount of power reflected from, transmitted through, and deposited in this layered system. The calculation procedure is described in detail. It is shown that in many cases it is possible to gain great savings in matrix size if the cross-pole scattering parameters are negligible. This has been found to be the case for many FSS elements (square patches, cross dipoles, monopoles, and square loop) when the angle of incidence is small (less than 10 degrees ). >
Effects of high energy irradiation on polypropylene

Isotactic polypropylene (Profax) film samples irradiated in the Pennsylvania State University reactor at ambient temperatures were examined by solvent extraction and infrared absorption techniques. At low irradiation doses, samples annealed (density = 0.909 g/cc at 24 deg C) prior to irradiation were found to have a lower gel content and a hlgher concentration of oxidation products than quenched samples (density = 0.899 g/cc at 24 deg C) irradiated under identical conditions. Similar gel fraction results were obtained for electron irradiated samples of polypropylene. The effects are believed to arise from the accumulation of a greater concentration of free macroradicals in the higher density samples. At hlgher reactor dosages the irradiation effects in the annealed and quenched films appeared to be about the game. The gel content as a function of dose was found to be independent of the irradiation intensity level over a twofold range. Irradiations were also carried out on high density polyethylene (Marlex 50) pellets at two temperatures, viz, 40 plus or minus 10 deg C and 150 deg C. Irradiation at 150 deg C led to a greater gel content at any given dose. Nuclear magnetic resonance spectra were obtained for molded annealed samples of partially isotacticmore » polypropylene, irradiated at temperatures of 90 to 330 deg K. The observed shifts in the line narrowing process that occur in the 270 to 530 deg K region are explained in terms of the decrease in crystallinity and the increasing density of crosslinks that accompany irradiation. (P.C.H.)« less
A technique for overlapping computation and communication for block recursive algorithms

SUMMARY This paper presents a design methodology for developing efficient distributed-memory parallel programs for block recursive algorithms such as the fast Fourier transform (FFT) and bitonic sort. This design methodology is specifically suited for most modern supercomputers having a distributed-memory architecture with a circuit-switched or wormhole routed mesh or a hypercube interconnection network. A mathematical framework based on the tensor product and other matrix operations is used for representing algorithms. Communication-efficient implementations with effectively overlapped computation and communication are achieved by manipulating the mathematical representation using the tensor product algebra. Performance results for FFT programs on the Intel Paragon are presented. ©1998 John Wiley & Sons, Ltd.
A top-down approach to classify enzyme functional classes and sub-classes using random forest

Advancements in sequencing technologies have witnessed an exponential rise in the number of newly found enzymes. Enzymes are proteins that catalyze bio-chemical reactions and play an important role in metabolic pathways. Commonly, function of such enzymes is determined by experiments that can be time consuming and costly. Hence, a need for a computing method is felt that can distinguish protein enzyme sequences from those of non-enzymes and reliably predict the function of the former. To address this problem, approaches that cluster enzymes based on their sequence and structural similarity have been presented. But, these approaches are known to fail for proteins that perform the same function and are dissimilar in their sequence and structure. In this article, we present a supervised machine learning model to predict the function class and sub-class of enzymes based on a set of 73 sequence-derived features. The functional classes are as defined by International Union of Biochemistry and Molecular Biology. Using an efficient data mining algorithm called random forest, we construct a top-down three layer model where the top layer classifies a query protein sequence as an enzyme or non-enzyme, the second layer predicts the main function class and bottom layer further predicts the sub-function class. The model reported overall classification accuracy of 94.87% for the first level, 87.7% for the second, and 84.25% for the bottom level. Our results compare very well with existing methods, and in many cases report better performance. Using feature selection methods, we have shown the biological relevance of a few of the top rank attributes.
Failure to detect changes to attended objects in motion pictures

Our intuition that we richly represent the visual details of our environment is illusory. When viewing a scene, we seem to use detailed representations of object properties and interobject relations to achieve a sense of continuity across views. Yet, several recent studies show that human observers fail to detect changes to objects and object properties when localized retinal information signaling a change is masked or eliminated (e.g., by eye movements). However, these studies changed arbitrarily chosen objects which may have been outside the focus of attention. We draw on previous research showing the importance of spatiotemporal information for tracking objects by creating short motion pictures in which objects in both arbitrary locations and the very center of attention were changed. Adult observers failed to notice changes in both cases, even when the sole actor in a scene transformed into another person across an instantaneous change in camera angle (or “cut”).