cssi/SciSciGPT-SciSciNet huggingface dataset:
Transmission and infectivity of spores of Burenella dimorpha (Microsporida: Burenellidae)

Abstract Burenella dimorpha infects the tropical fire ant, Solenopsis geminata , producing two morphologically distinct types of spores. A binucleate, nonpansporoblast membrane-bounded (NPMB) spore develops in and destroys the hypodermis, rupturing the cuticle in the pupal stage. A uninucleate, pansporoblast membrane-bounded (PMB) spore develops in the fat body. Adult ants cannibalize ruptured pupae but do not ingest spores. Instead, the spores and particulate foods are diverted to the infrabuccal cavity, formed into an infrabuccal pellet, and fed to fourth-instar larvae only. This larval instar is the only stage in the life cycle of S. geminata that is vulnerable to infection. NPMB spores are infective, but PMB spores do not extrude their polar filaments in the larval gut and are expelled in the meconium upon pupation.
Bio-inspired actuating system for swimming using shape memory alloy composites

The paper addresses the designs of a caudal peduncle actuator, which is able to furnish a thrust for swimming of a robotic fish. The caudal peduncle actuator is based on concepts of ferromagnetic shape memory alloy (FSMA) composite and hybrid mechanism that can provide a fast response and a strong thrust. The caudal peduncle actuator was inspired by Scomber Scombrus which utilises thunniform mode swimming, which is the most efficient locomotion mode evolved in the aquatic environment, where the thrust is generated by the lift-based method, allowing high cruising speeds to be maintained for a long period of time. The morphology of an average size Scomber Scombrus (length in 310 mm) was investigated, and a 1:1 scale caudal peduncle actuator prototype was modelled and fabricated. The propulsive wave characteristics of the fish at steady speeds were employed as initial design objectives. Some key design parameters are investigated, i.e. aspect ratio (AR) (AR = 3.49), Reynolds number (Re = 429 649), reduced frequency (σ = 1.03), Strouhal number (St = 0.306) and the maximum strain of the bent tail was estimated at e = 1.11% which is in the range of superelasticity. The experimental test of the actuator was carried out in a water tank. By applying 7 V and 2.5 A, the actuator can reach the tip-to-tip rotational angle of 85° at 4 Hz.
Borate as a Phosphate Ester Mimic in Aldolase‐Catalyzed Reactions: Practical Synthesis of L‐Fructose and L‐Iminocyclitols

Dihydroxyacetone phosphate (DHAP)-dependent aldolases have been widely used for the organic synthesis of unnatural sugars or derivatives. The practicality of using DHAP-dependent aldolases is limited by their strict substrate specificity and the high cost and instability of DHAP. Here we report that the DHAP-dependent aldolase L-rhamnulose 1-phosphate aldolase (RhaD) accepts dihydroxyacetone (DHA) as a donor substrate in the presence of borate buffer, presumably by reversible in situ formation of DHA borate ester. The reaction appears to be irreversible, with the products thermodynamically trapped as borate complexes. We have applied this discovery to develop a practical one-step synthesis of the non-caloric sweetener L-fructose. L-Fructose was synthesized from racemic glyceraldehyde and DHA in the presence of RhaD and borate in 92 % yield on a gram scale. We also synthesized a series of L-iminocyclitols, which are potential glycosidase inhibitors, in only two steps.
Lithium-7 NMR investigation of electrochemical reaction of lithium with SnO

Abstract We report on solid state 7Li NMR measurements of electrochemically lithiated SnO. At low Li contents (Li/SnO≤2), the results are consistent with the formation of amorphous Li2O. For Li/SnO ratio of 4.3, in addition to the amorphous Li2O phase, there are at least two distinct Sn/Li alloy environments which are similar to those observed in a reference Li2.3Sn alloy. However the Li+ environments in a sample with Li/SnO ratio equal to 6.4 and an Li4.4Sn reference alloy differ markedly. The NMR data are thus consistent with the simple model of Li insertion proposed by other groups, involving the formation of Li2O and LixSn alloys (SnO+xLi→Li2O+Lix−2Sn), at low and intermediate Li contents. At high Li content, however, the Lix−2Sn alloy structure is significantly different in the electrochemically lithiated SnO material, compared to that in the reference alloy.
Dication salts of BEDT-TTF

Abstract Dication salts of the organic donor bis (ethylenedithio)tetrathiofulvalene (BEDT-TTF), BEDT-TTF(ClO 4 ) 2 and BEDT-TTF(BF 4 ) 2 , have been prepared by electrocrystallization from an oxidizing solvent medium. The crystal structures of the isostructural salts are described and bondlengths in the dication are discussed.
Does tolerance develop to the activating, as well as the depressant, effects of ethanol?

Abstract Genetically determined differences were demonstrated in the response of mice to low doses of ethanol. Ethanol (1.35 g/kg) produced an increase in locomotion in DBA/2 and BALB/c mice, but did not alter the locomotor activity of C57B1/6 mice. Chronic administration of ethanol produced tolerance to the sedative/hypnotic effects of high doses of ethanol in DBA/2 and BALB/c mice, but the equivalent chronic ethanol administration paradigm produced no tolerance to the activating effects of ethanol in these animals. C57B1/6 mice became tolerant to the hypnotic effects of ethanol, but no change in the behavior of these mice, given a low dose of ethanol, was noted after the mice were withdrawn from chronic feeding with ethanol-containing diets. The results indicate the presence of different mechanisms for tolerance development to the activating and depresant effects of ethanol, and indicate that strain-dependent differences in the activating effects of ethanol are not determined by an animal's greater sensitivity to the sedating effects of this drug.
Intergranular activation energies in YBa2Cu3O7 bulk superconductors

Abstract Ac susceptibility is used to measure a small shift of the coupling peak of the imaginary part of the ac susceptibility (ρ″) to a higher temperature as the frequency is increased. Applying the Bean model one obtains the zero-field and zero-temperature intergranular pinning potential U(0,0) and critical, integranular current density Jc(0,0) from the data. Here it is shown how one can calculate the intergranular flux creep activation energy Ea(T,H) as a function of the applied magnetic field H and the temperature T if the average grain radius Rg and the zero temperature London penetration depth λL(0) are known. We arrive at Ea(T,H) values between 0 and 26 me V for a range of temperatures between 0 and Tc and a range of ac fields between 0 and 20 Oe.
Molecular Analysis of Stem Cells and Their Descendants during Cell Turnover and Regeneration in the Planarian Schmidtea mediterranea

In adult planarians, the replacement of cells lost to physiological turnover or injury is sustained by the proliferation and differentiation of stem cells known as neoblasts. Neoblast lineage relationships and the molecular changes that take place during differentiation into the appropriate cell types are poorly understood. Here we report the identification and characterization of a cohort of genes specifically expressed in neoblasts and their descendants. We find that genes with severely downregulated expression after irradiation molecularly define at least three discrete subpopulations of cells. Simultaneous BrdU labeling and in situ hybridization experiments in intact and regenerating animals indicate that these cell subpopulations are related by lineage. Our data demonstrate not only the ability to measure and study the in vivo population dynamics of adult stem cells during tissue homeostasis and regeneration, but also the utility of studies in planarians to broadly inform stem cell biology in adult organisms.
In Search of Nurturing Schools: Creating Effective Learning Conditions:

Many school reform efforts focus on estabilshing standards, redesigning the school curriculum, and administering proficiency tests. These changes may have merit, but they all tend to suggest the student is the cause of diminished academic progress in schools.
Titanium Dioxide Nanoparticles: Grassian et al. Respond

Baveye and Laba have further analyzed the transmission electron micrograph (TEM) image shown in Figure 2A of our article (Grassian et al. (2007b) to quantitatively determine the extent of titanium dioxide nanoparticle clustering in the image by calculating the radial distribution function. The main point of doing this calculation was to demonstrate that TiO2 nanoparticle aggregates will not completely deaggregate even when subjected to harsh conditions.
Diver-based Rapid Response Capability for Maritime-Port Security Operations

Maritime-Port Security Dive Operations cross many geographic boundaries and regional jurisdictions, and are conducted by US Navy Explosive Ordnance Disposal (EOD), United States Coast Guard (USCG), Federal Bureau of Investigation (FBI), and Public Safety Dive Teams (PSDT). They include underwater search of ship hulls, piers, pilings, docks, and bottom berthing areas for improvised explosive devices (IEDs), contraband, mines, and other threats - and routinely occur in dark or turbid water in near zero visibility conditions.
Isolation of disease resistance genes from crop plants

Abstract The recent cloning of several resistance genes from diverse plant species, in combination with various technical advances, has provided new opportunities for accessing the great diversity of disease resistance genes in crop plants. Many resistance genes probably belong to clusters of large multigene families encoding receptor-like proteins that have evolved to have different specificities. The isolation of genes from crop species is being facilitated by continuing technical improvements to methods for the saturation of markers within genomic regions containing resistance genes, for the cloning and characterization of large genomic fragments, and for efficient complementation. The primary limitation to cloning resistance genes with known specificities will be the genetic definition of the targeted gene.
Dual Polarized Wideband Directional Coupled Sectorial Loop Antennas for Radar and Mobile Base-Station Applications

This paper presents a new dual polarized antenna structure with matching and radiation characteristics suitable for radar and base-station applications. Two slightly different designs based on a dual polarized radiating element are presented. For radar applications, the radiating element is used to excite the two degenerate modes of a cavity with square cross-section. The resulting overall antenna size is $0.5{\lambda _m} \times 0.5{\lambda _m} \times 0.2{\lambda _m}$ , where ${\lambda _m}$ is the free space wavelength at the minimum operating frequency. The measured results showed isolation better than 30 dB and voltage standing wave ratio (VSWR) less than 2.5 over 1–1.95 GHz as well as good radiation pattern performance. For base-station applications, the exciting element was placed in front of a metallic ground plane to increase the beamwidth. This results in a smaller antenna size ( $0.38{\lambda _m} \times 0.38{\lambda _m} \times 0.25{\lambda _m}$ ) at the expense of reduced directivity. The antenna is designed to work over 1710–2170 MHz which covers three common frequency bands of mobile radio application. The measured results showed return loss better than 14 dB over the operating band and more than 30 dB polarization isolation.
Honours service-learning & civic responsibility

Universities have been urged to prepare graduates for successful professional lives and fulfilling lives as civically responsible citizens. Pedagogies of engagement, like servicelearning, are touted as one means to achieve these goals. Connections between first-year experience and service-learning programs have been slow to develop. Further, empirical studies on service-learning in university honours education are similarly scarce. This article examines first-semester honours postsecondary students’ sense of civic responsibility before and after completing a service-learning program linking a course on the Evolution of Community to direct volunteerism in struggling schools. Based on pre-post-responses (n=119) to the Level III-Civic Responsibility Survey, analysis of variance with repeated measures showed that participants’ sense of civic responsibility was significantly increased over time on each of the dependent variables (i.e., community connectedness, civic attitudes, civic efficacy). Community connectedness scores increased significantly at the .005 level, F(1, 118) = 9.703, p = .002. The changes in civic attitudes and civic efficacy scores were extremely significant at the .0005 level, F(1, 118) = 14.498, p < .0005 and F(1, 118) = 23.56, p < .0005,
A Brownian motion version of the directed polymer problem

Consider a Brownian particle in three dimensions in a random environment. The environment is determined by a potential random in space and time. It is shown that at small noise the large-time behavior of the particle is diffusive. The diffusion constant depends on the environment. This work generalizes previous results for random walk in a random environment. In these results the diffusion constant does not depend on the environment.
Changes in epidemiologic associations with different exposure metrics: a case study of phthalate exposure associations with body mass index and waist circumference.

Abstract The use of human biomonitoring data to characterize exposure to environmental contaminants in epidemiology studies has expanded greatly in recent years. Substantial variability in effect measures may arise when using different exposure metrics for a given contaminant, and it is often not clear which metric is the best surrogate for the ‘causal’ or ‘true’ exposure. Here we evaluated variability and potential bias in epidemiologic associations resulting from the use of different phthalate exposure metrics in the 2009–2010 National Health and Nutrition Examination Survey (NHANES). We examined associations between urinary phthalate metabolites and the outcomes of body mass index (BMI) and waist circumference (WC). We examined each of the following NHANES-derived exposure metrics for metabolites of individual phthalates: molar excretion rate (nmol/min), molar amount (nmol), molar concentration (nmol/mL, with and without additional model adjustment for creatinine), creatinine corrected molar concentration (nmol/g creatinine), and reconstructed daily phthalate intake (nmol/kg/day). In order to investigate potential biasing effect of each metric, we first assumed that daily intake of the parent phthalate is the causal exposure. We then constructed a simulated population based on the 2009–2010 NHANES, and randomly assigned each individual a di-2-ethylhexyl phthalate (DEHP) intake dose based on a published distribution, but independent of any other factor. Accordingly, all associations between these randomly assigned intake doses and individuals' BMI and WC should be null. Next, demographic data in the NHANES were incorporated into a pharmacokinetic model to predict urinary molar excretions of five DEHP metabolites based on the randomly assigned DEHP intake. The predicted molar excretions were then used to calculate the same exposure metrics listed above. Three exposure metrics (randomly generated intake, excretion rate, urine concentration) showed no significant associations with BMI, which supports the null hypothesis stated above. In contrast, metrics adjusted for creatinine showed a significant negative correlation, and reconstructed daily intake showed a significant positive correlation, indicating the introduction of bias away from the true (i.e., null) association. Interestingly, trends in the simulation analysis were similar to those seen in the observed NHANES data. Our findings show that, at least in this example case, the choice of exposure metric can introduce significant bias of varying magnitude and direction into the calculation of epidemiologic associations.
Hyperoncotic enhancement of fetal pulmonary growth after tracheal occlusion: an alveolar and capillary morphometric analysis ☆

Abstract Background/Purpose Previous work has shown that intrapulmonary delivery of oncotic agents enhance overall lung growth after late gestational fetal tracheal occlusion (TO). This study was a post hoc analysis aimed at determining whether actual alveolar and capillary hyperplasias are maximized in this setting. Methods Twenty-one near term fetal lambs were evenly divided into 4 groups: group I comprised sham-operated controls; group II had TO alone; and groups III and IV underwent TO and intratracheal infusion of equal amounts of either saline or 25% albumin, respectively. Approximately 2 weeks thereafter, their lungs were examined by detailed alveolar and capillary morphometry before birth. Statistical analysis included analysis of variance and the Bonferroni correction for multiple comparisons ( P Results Total alveolar and capillary numbers, as well as total alveolar surface area, were significantly higher in group IV and lower in group I compared with all other groups, with no differences between groups II and III. Alveolar capillary load was normal in all groups. Conclusions Intrapulmonary delivery of concentrated albumin safely enhances short-term alveolar and capillary hyperplasia in a late gestational model of fetal TO. This therapeutic concept may allow for TO to be effective and predictable when performed late in gestation.
The FXYD gene family of small ion transport regulators or channels: cDNA sequence, protein signature sequence, and expression.

Abstract A gene family of small membrane proteins, represented by phospholemman and the γ subunit of Na,K-ATPase, was defined and characterized by the analysis of more than 1000 related ESTs (expressed sequence tags). In addition to new and more complete cDNA sequence for known family members (including MAT-8, CHIF, and RIC), the findings included two new family members and new splicing variants. A large number of EST replicates made it possible to derive curated DNA sequence with higher confidence and accuracy than from the sequencing of individual clones. The family has a core motif of 35 invariant and conserved amino acids centered on a single transmembrane span. Features of each predicted protein product were compared, and tissue distributions were determined. The gene family was named FXYD (pronounced fix-id) in recognition of invariant amino acids in its signature motif. The abundant proteins are involved in the control of ion transport.
PtPb nanoparticle electrocatalysts: control of activity through synthetic methods

Solution phase synthesis of intermetallic nanoparticles without using surfactants (for catalytic applications) and subsequent control of size distribution remains a challenge: of growing interest, but not widely explored yet. To understand the questions in the syntheses of Pt containing intermetallic nanoparticles (as electrocatalysts for direct fuel cells) by using sodium naphthalide as the reducing agent, the effects of the Pt precursors’ organic ligands were investigated. PtPb syntheses were studied as the model case. In particular, methods that lead to nanoparticles that are independent single crystals are desirable. Platinum acetylacetonate, which is soluble in many organic solvents, has ligands that may interfere less with nanoparticle growth and ordering. Interesting trends, contrary to expectations, were observed when precursors were injected into a reducing agent solution at high temperatures. The presence of acetylacetonate, from the precursor, on the nanoparticles was confirmed by ATR, while SEM imaging showed evidence of morphological changes in the nanoparticles with increasing reaction temperature. A definite relationship between domain size and extent of observed residue (organic material and sodium) present on the particles could be established. By varying post-reaction solvent removal techniques, room temperature crystallization of PtPb nanoparticles was also achieved. Electrochemical activity of the nanoparticles was also much higher than that of nanoparticles synthesized by previous reaction schemes using sodium naphthalide as the reducing agent. Along with the above mentioned techniques, BET, TEM, CBED, SAED, and XRD were used as characterization tools for the prepared nanoparticles.
Assembly and dispersal of supercontinents: The view from Avalon

Abstract Recent models for the post-750 Ma Rodinian supercontinent dispersal (e.g. Hoffman, 1991) envision that cratons margined by Grenvillian belts, were reorganized before ca 540 Ma to form the Gondwanan supercontinent. Laurentia and Baltica distanced themselves from Gondwana by moving out of the Rodinian cratonal cluster. West Gondwana, of which Avalon was a part during the late Proterozoic to Cambrian cratonal assembly, consisted mainly of Africa and South America. The main geological evidence is presented for: (1) a transition from continental platform conditions to those of a subduction-related volcanic arc regime in Late Proterozoic time during the dispersal of the Rodinian supercontinent, and the resulting assembly of the Gondwanan supercontinent; and (2) a second transition that marked a reversal from the volcanic arc regime to marine platformal environments by early Cambrian time. Evidence for progressive instability of the continental shelf margining the Rodinian supercontinent is contained in late Proterozoic olistostromes, mylonite zones, calc-alkaline magmatism, and arc-derived clastic rocks, some being glacigenic, during three phases of the Avalonian orogeny. By early Cambrian time the reversal from a tectonically unstable volcanic arc regime to more stable platformal conditions took place as Avalon, Armorica and related microcontinental blocks rifted from Gondwana. These Gondwanan fragments sequentially come into collision, first with each other and Baltica, and then with Laurentia in Mid to Late Paleozoic time as Pangaea was being assembled.
Intensive Nutrition Counseling Enhances Outcomes of National Cholesterol Education Program Dietary Therapy

Abstract Objective To compare the effect of the addition of medical nutrition therapy administered by a registered dietitian with the usual physician counseling on nutrition knowledge, attitudes regarding dietary change, body mass index, dietary intake, and lipid and lipoprotein concentrations during initial management of persons at risk for cardiovascular disease. Design A 3-month prospective, randomized trial of subjects stratified by sex and assigned to one of four nested treatment groups, which were subsequently collapsed into two groups. Subjects Fifty-two men and 52 women classified at risk for cardiovascular disease. Intervention Two groups of subjects received dietary counseling from a physician or nurse; in one group the Grocery Shopping Guide was used. Two other groups received medical nutrition therapy from a registered dietitian (one or three visits) in addition to the instruction from a physician or nurse and the information provided by the Grocery Shopping Guide. Statistical analyses Analyses of covariance were performed to determine differences between the groups. Paired t tests were performed to study changes within the groups. Results The group receiving medical nutrition therapy from a registered dietitian gained statistically significantly more nutrition knowledge; had significantly greater perceptions of the benefits and efficacy of following a cholesterol-lowering diet; consumed a significantly lower percentage of fat, higher percentage of carbohydrate, and less dietary cholesterol than subjects counseled only by a physician or nurse. They also had significantly greater improvement in body mass index. Both groups of subjects achieved statistically significant reductions in serum lipid levels. Applications Increased knowledge, benefits, and efficacy and lower-fat eating behaviors associated with additional nutrition therapy may have significant implications on the ability of persons to follow low-fat eating plans long term, which could reduce the need for costly medication intervention. J Am Diet Assoc. 1996; 96:1003-1010.
A modified access technique for retroperitoneoscopic renal surgery in children.

ABSTRACTPurpose: Present techniques for retroperitoneal endoscopic (RPE) access in children mimic those in adults but often result in peritoneal entry or gas leaks, both of which lead to a decrease in the retroperitoneal space. We describe a modification to the access technique that obviates these problems, thus, facilitating RPE in children.Materials and Methods: In the lateral decubitus position the initial port is placed immediately lateral to the paraspinal muscles, similar to open dorsal lumbotomy fascial incision. A 5 mm skin incision is made at the level of the costovertebral angle and an artery forceps used to tunnel bluntly past the lumbodorsal fascia. A 5 mm port is placed with a blunt trocar, and expansion of the retroperitoneal space performed with the telescope and gas insufflation. Ancillary ports are placed and the telescope then moved to an anterior subcostal port where popular RPE approaches place the initial port.Results: Eighteen procedures were performed in children with a mean age of ...
Heuristic methods for computer understanding of natural language in context-restricted on-line dialogues

Abstract This computer program accepts expressions in natural language as on-line input. It searches each expression for syntactic and semantic patterns. When a pattern match is discovered an appropriate reply is typed out in natural language so that a continuing dialogue develops between person and program. The dialogue is restricted to the context of interpersonal relations such as occurs in a psychiatric interview. The program is an interpreter/supervisor written in SUBALGOL and runs on a 32K IBM 7090 connected via a direct-data device to a PDP-1 and a Philco console.
Traitement d'une fistule entre l'artère mésentérique supérieure et la veine porte par stentgraft expansible par ballonnet

Les fistules arterioveineuses entre les arteres viscerales et la veine porte sont rares et difficiles a traiter. Les stents couverts ont rendu possible le traitement mini-invasif des faux-anevrismes et des fistules arterioveineuses. Nous presentons le cas d'un homme de 46 ans avec une histoire de laparotomie exploratrice apres un accident de moto qui se presenta avec des douleurs abdominales, un malaise, et un ictere. Le scanner montrait une fistule arterioveineuse entre l'artere mesenterique superieure et la veine porte. Une fistule arterioveineuse large etait confirmee par l'arteriographie. Une stentgraft expansible par ballonnet fut place au niveau de la fistule arterioveineuse dans l'artere mesenterique superieure. Apres la procedure, la douleur abdominale du patient ceda et la bilirubine diminua de 2,9 a 0,4. Le traitement endovasculaire d'une fistule arterioveineuse entre l'artere mesenterique superieure et la veine porte avec un stentgraft est faisable et mini-invasif.
Physical stability and relaxation of amorphous indomethacin.

The α- and β-relaxation processes in amorphous indomethacin have been studied by using differential scanning calorimetry. The β-process has been detected as a small endothermic peak that emerges before the glass transition step when reheating samples previously annealed in the temperature region −20 to +5 °C. The activation energy of the β-process is ∼57 kJ mol-1, and shows an increase with increasing temperature as it approaches the glass transition region. In the glass transition region, the effective activation energy of relaxation decreases with increasing temperature from 320 to 160 kJ mol-1. Heat capacity measurements have allowed for the evaluation of the cooperatively rearranging region in terms of the linear size (3.4 nm) and the number of molecules (90). The β-relaxation fades below −30 °C, which provides a practical estimate for the lower temperature limit of physical instability in indomethacin. It is demonstrated experimentally that nucleation of indomethacin takes place in the temperature re...
Physics of Selective Systems: Computation and Biology

The statistical thermodynamics of systems displaying selective behavior is used to discuss some important ultimate physical limitations of computers and biological systems. These cluster around communication of information, measurement, and irreversible processes. The most fundamental limitation is irreducible increase of entropy accompanying selective acts like measurement of preparation. Relevant theory of machines (automata. Turing machines) and issues involved in physical realizations of those machines are discussed. Quantum measurement, the Einstein-Podolsky-Rosen paradox, the fundamental importance of irreversibility, information and entropy, and their relation to Goedel's theorems on completeness and consistency of formal systems are analyzed. Irreversibility of measurement appears necessary to provide quantum mechanics with the incompleteness needed to avoid inconsistency. Motivation and justification of computer paradigms for fundamental modeling of biological systems is given.
The shape of Mars from the Mariner 9 occultations.

The extinction time of the radio signal, as the Mariner 9 spacecraft was occultated by Mars, together with an accurate ephemeris of the spacecraft were used to determine radii from the mass center to the occulting feature. Similarly estimations were made of the radius to a point where the pressure reached a certain fixed value. Several simple models were proposed to fit both sets of radii data.
Visibility-Based Pursuit-Evasion in an Unknown Planar Environment:

We address an on-line version of the visibility-based pursuit-evasion problem. We take a minimalist approach in modeling the capabilities of a pursuer robot. A point pursuer moves in an unknown, simplyconnected, piecewise-smooth planar environment, and is given the task of locating any unpredictable, moving evaders that have unbounded speed. The evaders are assumed to be points that move continuously. To solve the problem, the pursuer must for each target have an unobstructed view of it at some time during execution. The pursuer is equipped with a range sensor that measures the direction of depth discontinuities, but cannot provide precise depth measurements. All pursuer control is specified either in terms of this sensor or wall-following movements. The pursuer does not have localization capability or perfect control. We present a complete algorithm that enables the limited pursuer to clear the same environments that a pursuer with a complete map, perfect localization, and perfect control can clear (unde...
An Evaluation of the Role of Africa in the World Nuclear Economy

In this paper the author investigates the present role of Africa in the world nuclear economy. The continent is a major producer of uranium, and a potential site for nuclear waste dumps, but participates only minimally in the actual use of nuclear energy. This role, it is argued, is inimical to efforts for long-term development. Some of the fallacies which perpetuate this role, especially the economic rationality of waste imports, are investigated and there is an elaboration of the need for a policy framework to change the existing conditions under which the region participates in the world nuclear economy. Alternative strategies to effect these changes are evaluated, and a regional approach is considered to be the most realistic.
The use of fluoro- and deoxy-substrate analogs to examine binding specificity and catalysis in the enzymes of the sorbitol pathway.

Abstract The carbohydrate specificity of the two enzymes that catalyze the metabolic interconversions in the sorbitol pathway, aldose reductase and sorbitol dehydrogenase, has been examined through the use of fluoro- and deoxy-substrate analogs. Hydrogen bonding has been shown to be the primary mode of interaction by which these enzymes specifically recognize and bind their respective polyol substrates. Aldose reductase has broad substrate specificity, and all of the fluoro- and deoxysugars that were examined are substrates for this enzyme. Unexpectedly, both 3-fluoro- and 4-fluoro- d -glucose were found to be better substrates, with significantly lower Km and higher kcat/Km values than those of d -glucose. A more discriminating pattern of substrate specificity is observed for sorbitol dehydrogenase. Neither the 2-fluoro nor the 2-deoxy analogs of d -glucitol were found to be substrates or inhibitors, suggesting that the 2-hydroxyl group of sorbitol is a hydrogen bond donor. The 4-fluoro and 4-deoxy analogs are poorer substrates than sorbitol, also implying a binding role for this hydroxyl group. In contrast, both 6-fluoro- and 6-deoxy- d -glucitol are very good substrates for sorbitol dehydrogenase, indicating that the primary hydroxyl group at this position is not involved in substrate recognition by this enzyme.
Epilithic bacterial and algal colonization in a stream run, riffle, and pool: a test of biomass covariation

Epilithic bacterial and algal biomass were compared among a run, riffle, and pool along an open-canopy section of a third-order, temperate stream. Epilithic biofilms were sampled after 3, 7, 14, 21, 28, and 35 days colonization on unglazed ceramic tiles that were attached to plastic trays (n = 3) placed across each of the three habitats (i.e., run, riffle, pool). The diverse habitats and sampling regime were selected to provide a range in algal biomass so that potential covariation between epilithic bacterial and algal biomass could be assessed. There were significant differences among habitats and among trays within each habitat for both chlorophyll a and AFDM. Chlorophyll a and AFDM increased in the run and pool throughout the colonization period. In the riffle, chlorophyll a and AFDM increased rapidly early in colonization, then decreased. Epilithic bacterial biomass increased rapidly with no significant differences among the three habitats throughout colonization. Further, bacterial biomass did not correlate with either chlorophyll a or AFDM in any of the three habitats or on any of the sampling days. These results suggest that epilithic algal and bacterial biomass may be regulated by independent controls in some stream environments.
Navigation path differences for dichotic listening BCI in virtual environments

Our research is focused on the initial exploration of training a Brain Computer Interface (BCI) by using audio cues to navigate a virtual environment, instead of motor imagery. We have designed our BCI training and navigation to use audio cues that adhere to the dichotic listening (DL) mechanism so that users have an active choice for interaction or giving commands. We have implemented our Dichotic Listening BCI in a Virtual Environment so that it can be used to train users with disabilities to apply those skills for a BCI to control a real-world assisted locomotive device or to simply navigate within the virtual environment. We hypothesized that the lateralization of the brain's response to music and speech will enhance the classification of a BCI. Unlike previous attempts in using the oddball paradigm, our results show that audio cues can be used simultaneously to elicit distinct EEG signals for BCI while still enabling an active choice for the user. We evaluated users' performance to actively input navigation tasks. Dichotic Listening BCI performs slightly better than Motor Imagery based BCI. In addition navigation paths reveal participants having more navigation control when using Dichotic Listening.
Beauty Contests and Iterated Expectations in Asset Markets

In a financial market where traders are risk averse and short lived, and prices are noisy, asset prices today depend on the average expectation today of tomorrow’s price. Thus (iterating this relationship) the date 1 price equals the date 1 average expectation of the date 2 average expectation of the date 3 price. This will not in general equal the date 1 average expectation of the date 3 price. We show how this failure of the law of iterated expectations for average belief can help understand the role of higher order beliefs in a fully rational asset pricing model and explain over-reaction to (noisy) public information.
Biochemical Genetics of Respiration-Deficient Mutants of Animal Cells

Given an abundant supply of glucose and oxygen, mammalian cells have a capacity for energy production (ATP synthesis) that far exceeds the need of the cell. The control of energy metabolism in normal cells is exquisite, and it has presented a fascinating challenge to several generations of biochemists. On the one hand, ATP is generated only when it is needed, but a viable cell also maintains its energy charge at a constant level (Atkinson, 1968, 1977).
Combinatorial Drug Conjugation Enables Nanoparticle Dual‐Drug Delivery

A new approach to loading multiple drugs onto the same drug-delivery nanocarrier in a precisely controllable manner, by covalently preconjugating multiple therapeutic agents through hydrolyzable linkers to form drug conjugates, is reported. In contrast to loading individual types of drugs separately, this drug-conjugates strategy enables the loading of multiple drugs onto the same carrier with a predefined stoichiometric ratio. The cleavable linkers allow the therapeutic activity of the individual drugs to be resumed after the drug conjugates are delivered into the target cells and unloaded from the delivery vehicle. As a proof of concept, the synthesis and characterization of paclitaxel‐gemcitabine conjugates are demonstrated. The time-dependent hydrolysis kinetics and cytotoxicity of the combinatorial drug conjugates against human pancreatic cancer cells are examined. It is shown that the synthesized drug conjugates can be readily encapsulated into a lipid-coated polymeric drug-deliverynanoparticle,which significantly improves the cytotoxicity of the drug conjugates as compared to the free drug conjugates.
Modeling of skin tissue ablation by nanosecond pulses from ultraviolet to near-infrared and comparison with experimental results

Comprehension of biological tissue ablation by short laser pulses in a broad optical spectrum is of fundamental importance to the understanding of laser-tissue interaction and advancing surgical applications of lasers. We report a new plasma ablation model in which the chromophore ionization pathway is incorporated to explain the skin tissue ablation by nanosecond laser pulses from ultraviolet to near-infrared. A rate equation is solved to examine the effects of chromophore, cascade, and multiphoton ionization on the optical breakdown of the tissue. The wavelength and spot size dependence of the breakdown thresholds have been measured and agreements have been found between the calculated and measured results.
Enhancing electrical energy storage using polar polyimides with nitrile groups directly attached to the main chain

A set of 12 new polyimides (PIs) with one or three polar CN dipoles directly attached to the aromatic diamine part were synthesized and their electric energy storage properties were studied using broadband dielectric spectroscopy (BDS) and electric displacement–electric field (D–E) loop measurements to determine their potential for high temperature film capacitors for aerospace applications. It was found that adding highly polar nitrile groups to the PI structure increased permittivity and thus electrical energy storage, especially at high temperatures, and 3 CN dipoles were better than 1 CN dipole. Below the glass transition temperature (Tg), a weak γ transition was observed around −100 °C and a broad β transition was observed between 100 and 150 °C. It was the β (i.e., precursor dipolar motion before long-range segmental motion, or glass transition), rather than the γ sub-Tg transition that substantially increased the permittivity of PIs. From the BDS results on PIs having 3 nitrile groups, the enhancement in permittivity from permanent dipoles decreased with dianhydride in the order of pyromellitic dianhydride (PMDA) > 4,4′-oxydiphthalic dianhydride (OPDA) > 1,1,1,3,3,3-hexafluoropropane dianhydride (6FDA) > 4,4′-benzophenonetetracarboxylic dianhydride (BTDA). Meanwhile, the increase in permittivity also decreased in the order of para–para, meta–para, and meta–meta linkage in the diamine, suggesting that the para–para linkage favored easier dipole rotation than the meta–meta linkage. From the D–E loop study, the PIs with a combination of PMDA dianhydride and a para–para linkage exhibited the highest discharged energy density and a reasonably low loss.
Comparison of Two Methods for INR Determination in a Pharmacist-Based Oral Anticoagulation Clinic

Warfarin is a commonly used oral anticoagulant that is usually initiated after the definitive diagnosis of a certain thromboembolic disorder or disease. Warfarin therapy will usually be prescribed for 6-12 weeks or more, and some patients may continue therapy throughout life, depending on the type of thromboembolic disorder. Major problems associated with warfarin therapy include adverse effects such as bleeding complications and drug-drug or drug-food interactions. In addition, thromboembolic complications may occur due to subtherapeutic dosages of warfarin. The laboratory reference standards for monitoring warfarin therapy are the prothrombin time (PT) and the International Normalized Ratio (INR). While both the PT or INR will reflect the clinical response in the patient, results reported as INR values have been shown to be more accurate than those reported as PT values. Thirty-two patients were enrolled in this study. Our objectives were to compare INR values measured by both the Coumatrak and conventional laboratory method, and to demonstrate the effects of pharmacist intervention on managing patients receiving warfarin therapy. Results from our study reveal that INR monitoring by Coumatrak is similar to the conventional laboratory method. In addition, our study indicates that patients receiving warfarin therapy can be monitored and managed effectively by pharmacists.
Fantasizers and dissociaters: data on two distinct subgroups of deep trance subjects.

Summary.-This study delineated two subgroups of hghly hypnotizable subjects. The first (n = 19) entered trance rapidly, scored high on absorption, and described hypnosis as much like their rich and vivid waking fantasy life. The second subgroup of 15 took time to achieve a deep trance, saw hypnosis as very ddferent from any prior experiences, and were more likely to exhibit amnesia for both hypnotic experience and waking fantasies. Wilson and Barber (1981, 1983) described a group of highly hypnotizable subjects whom they termed "fantasizers" because they showed extreme involvement in imaginative activity. Subsequent research has confirmed a relationship of hypnotizability and fantasy proneness which accounts, however, for a small amount of common variance (Lynn & Rhue, 1988). In addition to standard criteria for high hypnotizability, Wilson and Barber included the ability to re-enter hypnosis rapidly without a formal induction. The purpose of the present study was to examine whether highly hypnotizable subjects who were not capable of entering a deep trance rapidly were as fantasy-prone as those who could do so and whether there were other traits which might distinguish them. METHOD Thirty-four extremely hypnotizable subjects were selected from among approximately 1200 undergraduate subject volunteers who had been hypnotized in the course of other research projects and demonstrations in classroom and dormitory settings over a seven-year period. They were selected using two standard scales, The Harvard Group Scale of Hypnotic Susceptibility, Form A (Shor & Orne, 1962) and the Stanford Scale of Hypnotic Susceptibility, Form C (Weitzenhoffer & Hilgard, 1962). All subjects scored either 11 or 12 on both scales. This constituted a very similar criterion for hypnotic susceptibility to Wilson and Barber's, with the exception of not requiring immediate response to deep trance suggestions without a formal induction. The mean age of selected subjects was 21.3 yr., with 22 women and 12 men. Subjects were hypnotized a total of three or four times, with zero to one of these experiences being solely for the present experiment and one to two by the present experimenter. Their hypnotic experiences included both those
Juvenile xanthogranuloma of the superior mediastinum resulting in upper airway obstruction

Summary Juvenile xanthogranuloma (JXG) is the most common form of non-Langerhans histiocytosis in the pediatric population. JXG most typically presents as a subcutaneous nodule. The natural course of the disease is usually spontaneous resolution without treatment. However, there have been case reports of juvenile xanthogranuloma involving the larynx and trachea that required treatment for symptoms of airway obstruction. We describe the first case of juvenile xanthogranuloma involving the superior mediastinum with impingement on the trachea causing airway obstruction.
Systemic reform in undergraduate engineering education: the role of collective responsibility

Traditionally, members of a department faculty value their autonomy. But their home department has a set of collective responsibilities involving other departments in the college, the university, and external constituent groups. Consider the following scenario. In a certain department faculty are judged individually to be very well qualified. Each person's academic and other scholarly achievements can clearly be documented as meritorious. However, the collective activities and achievements of these individuals fall measurably short of their department's collective responsibilities. More specifically, an individual might bring highly innovative concepts into an existing engineering course that are highly valued by external funding agencies, by peer institutions, and by the employers of the department's graduates. Yet these innovations are lost once this person is no longer the course instructor. This paper examines the relationships among faculty autonomy, the collective responsibility of the department faculty, and systemic reform in undergraduate engineering education.
Medullary position at the craniocervical junction in mature cavalier King Charles spaniels: relationship with neurologic signs and syringomyelia.

Background Medullary elevation (ie, medullary kinking) at the craniocervical junction (CCJ) is reported in dogs with Chiari-like malformations (CM), but its diagnostic criteria and clinical relevance are unclear. Objective To describe the position of the medulla at the CCJ in mature cavalier King Charles spaniels (CKCS), and evaluate its relationship with clinical status and the presence of syringomyelia. Animals Thirty-six CKCS, 5–12 years of age, including 16 asymptomatic dogs. Methods Dogs were assigned a neurologic grade; magnetic resonance imaging (MRI) of the CCJ then was performed. The presence of a CM and syringomyelia was recorded and syringomyelia severity was quantified. Medullary position was quantified using the medullary kinking index, the elevation angle and obex position relative to the foramen magnum. The relationship between medullary position measures and presence and severity of neurologic signs and syringomyelia was investigated. Results Chiari-like malformation was found in 33 dogs; 26 of them had syringomyelia. Mean medullary kinking index was 46.4% (SD, 10.3), elevation angle was 132° (SD, 12) and obex position was 3.5 mm (SD, 0.8). A higher medullary kinking index was associated with the presence of neurologic signs (P = .0368). Obex position was associated with the presence (P = .0018) and severity of syringomyelia (P = .0164). Conclusions and clinical importance There is a significant association between medullary elevation and clinical signs, whereas more caudal brainstem positions appear related to the presence of syringomyelia.