cssi/SciSciGPT-SciSciNet huggingface dataset:
Some cycloaddition reactions of halomethylenecyclopropanes

Abstract Bromo-,chloro- and ethoxymethylenecyclopropane 3–5 undergo head to head dimerzations at 185–195° to give the corresponding 7,8-disubtituted dispiro[2.0.2.2]octanes 6–8 in high yields. Chloromethylenecyclopropane 4 undergoes cross cycloaddition reactions with near equimolar amounts of 3 and 5 to give about 50% of the corresponding mixed 7,8-disubstituted dispiro[2.0.2.2]octanes together with equal parts of 6 and 7 or 6 and 8. Bromo- and choromethylenecyclopropane also undergo similar cross cycloaddition reactions with methelene-cyclopropane to give the 7-halodispiro[2.0.2.2]octanes, but in relatively poor yields. At 190°, 4 reacts with 1,3-cyclopentadiene, furan, and 1,3-cyclohexadiene to give the products of (2+4) cycloaddition 12–14. With 2,3-dimethyl-1,3-butadiene at 190° ,4 gives the unusual products 18–20 in yields of 35%, 8% and 13%, respectively, and with acryloionitrile 4 gives exclusively 21, the product of (2+2) cycloaddition. Relative reactivities of 4 with furan, 2,3-dimethyl-1,3-butadiene, 1,3-cyclohexadiene, acrylonitrile and 1,3-cyclopentadiene were estimated as 1:2.5:2.5:4:and 50,respectively.
Recycling single-wall carbon nanotube anodes from lithium ion batteries

Large scale incorporation of nanomaterials into industrial systems and commercial products is relatively new, and therefore little attention has been given for options when these products reach their end-of-life. During the course of this study, the ability to recycle end-of-life (EOL) single-wall carbon nanotubes (SWCNTs), recovered from lithium ion battery electrodes, was investigated. Specifically, SWCNT–Li+ coin cells were forced to their EOL though extended cycling at high charge rates and recycled using a series of acid and thermal treatments originally developed for the purification of as-produced SWCNT material. The recycling treatments were successful in removing the EOL byproducts (e.g. solid electrolyte interphase, lithium) and upgrading the SWCNT material to its pre-cycling functionality. The material was characterized at each step in the recycling process through a combination of scanning electron microscopy, thermogravimetric analysis, Raman spectroscopy, and optical absorption spectroscopy. The energy required for each of the recycling procedures was measured and compared to the energy of SWCNT synthesis. The recycled-SWCNT material was successfully incorporated into Li+ battery coin cells with insertion and extraction capacities of 650 mA h g−1, comparable to the virgin pure-SWCNT electrodes. Therefore, the ability to refunctionalize “used” SWCNTs from a device, through chemical processing, to their initial purity and functionality has been demonstrated. The direct energy required to refunctionalize the SWCNTs was measured and is less than half of the direct energy required to synthesize new material. Thus, the ability to preserve the nanoscale properties of SWCNTs with reduced impact offers new opportunities for end-of-life management.
Optimal energy-aware epidemic routing in DTNs

In this work, we investigate the use of epidemic routing in energy constrained Delay Tolerant Networks (DTNs). In DTNs, connected paths between source and destination rarely materialize due to the mobility and sparse density of nodes. Epidemic routing is well-suited for these environments due to its simplicity and fully distributed implementation. In epidemic routing, messages are relayed by intermediate nodes at contact opportunities, i.e., when pairs of nodes come within transmission range. Each node needs to decide whether to forward its message upon contact with a new node based on its residual energy level and the age of that message.We mathematically characterize the fundamental trade-off between energy conservation and forwarding efficacy as a heterogeneous dynamic energy-dependent optimal control problem. We prove, somewhat surprisingly given the complex nature of the problem, that in the mean field regime, the optimal dynamic forwarding decisions follow simple threshold-based structures in which the forwarding threshold for each node depends on its current remaining energy. We analytically establish this result under generalized classes of utility functions for DTNs. We then characterize the dependence of these thresholds on current energy reserves in each node.
GOLDFISH CONES SECRETE A TWO-REPEAT INTERPHOTORECEPTOR RETINOID-BINDING PROTEIN

Vitamin A and fatty acids are critical to photoreceptor structure, function, and development. The transport of these nutrients between the pigment epithelium and neural retina is mediated by interphotoreceptor retinoid-binding protein (IRBP). IRBP, a 133-kDa (human) glycolipoprotein, is the major protein component of the extracellular matrix separating these two cell layers. In amphibians and mammals, IRBP consists of four homologous repeats of about 300 amino acids which form two retinol and four fatty acid-binding sites. Here we show that IRBP in teleosts is a simpler protein composed of only two repeats. Western blot analysis shows that goldfish IRBP is half the size (70 kDa) of IRBP in higher vertebrates. Metabolic labeling studies employing Brefeldin A taken together with in situ hybridization studies and the presence of a signal peptide show that goldfish IRBP is secreted by the cone photoreceptors. The translated amino acid sequence has a calculated molecular weight of 66.7 kDa. The primary structure consists of only two homologous repeats with a similarity score of 52.5%. The last repeats of human and goldfish IRBPs are 69.1% similar with hydrophobic regions being the most similar. These data suggest that two repeats were lost during the evolution of the ray-finned fish (Actinopterygii), or that the IRBP gene duplicated between the emergence of bony fish (Osteichthyes) and amphibians. Acquisition of a multirepeat structure may reflect evolutionary pressure to efficiently transport higher levels of hydrophobic molecules within a finite space. Quadruplication of an ancestral IRBP gene may have been an important event in the evolution of photoreceptors in higher vertebrates.
Fracture of knitted randomly oriented short-fiber composite

Fracture behavior of a chopped-mat E-glass fiber reinforced hybrid resin composite knitted with continuous poly(ethylene terephthalate) (PET) fibers is investigated by a combined experimental and analytical study. In both opening-mode (mode-I) and shear-mode (mode-II) fracture studies of the composite, the macroscopic critical stress intensities or toughnesses of the material are found to be distinct along the warp and fill directions of the knitting PET fibers. Values of KIIc(F) and KIIc(F) are lower than those of KIc(W), owing to different fracture mechanisms involved. In the mixed-mode fracture of the composite, a failure envelope in KI and KII is constructed. The different mechanisms involved in opening-mode, mode-II and mixed-mode fracture are studied with SEM observations.
Do Francophone and Islamic schooling communities participate differently? Disaggregating parents' political behaviour in Mali

Despite strong empirical evidence of the influence of religious brokers on political mobilisation in Africa, we know very little about the individual-level relationship between religious association and political behaviour. Drawing upon an emerging comparative literature on the effect of social service provision on political participation, this article asks whether Malian consumers of Islamic schooling are as likely to seize new democratic opportunities for electoral participation as their peers who send their children to public schools. Using an original survey of 1,000 citizens, exit polling and interviews, this analysis demonstrates that parents who enrol their children in madrasas are less likely than other respondents to report voting. Conversely, parents who send their children to public schools are more likely to participate in electoral politics.
Reaction of a Tungsten Alkylidyne Complex with a Chelating Diphosphine. α-Hydrogen Migration in the Intermediates and Formation of an Alkyl Alkylidene Alkylidyne Complex

The reaction of W(CH2SiMe3)3(≡CSiMe3) (1) with DMPE (DMPE = Me2PCH2CH2PMe2) gives an adduct W(CH2SiMe3)3(≡CSiMe3)(DMPE-P) (4a), which undergoes a rarely observed reversible transformation to its bis-alkylidene tautomer W(CH2SiMe3)2(═CHSiMe3)2(DMPE-P) (4b) through α-H migration. The DMPE ligands in both 4a and 4b contain a dangling P atom (P). Thermodynamic and kinetic studies of the 4a ⇌ 4b exchange show that it is slightly endothermic with ΔH° = 5.1(1.1) kcal/mol and ΔS° = 24(4) eu; ΔH1⧧ = 7.5(0.9) kcal/mol, ΔS1⧧ = −51(2) eu for the 4a → 4b forward reaction; ΔH−1⧧ = 2.0(0.8) kcal/mol, ΔS−1⧧ = −76(1) eu for the 4b → 4a reverse reaction. Activation entropies are the major contributors to the activation barriers of the exchange: ΔG1⧧278K = 21.7(1.5) kcal/mol and ΔG−1⧧278K = 23.1(1.1) kcal/mol. The 4a ⇌ 4b exchange at 283 K is faster than that of the previously reported PMe3 analogs W(CH2SiMe3)3(≡CSiMe3)(PMe3) (2a) ⇌ W(CH2SiMe3)2(═CHSiMe3)2(PMe3) (2b).(1) The 4a ⇌ 4b mixture undergoes an α-H abstraction, yie...
High-Pressure Synthesis and Crystal Structure of CaFeTi2O6, a New Perovskite Structure Type

Abstract Single-crystal and powder samples of a new calcium iron(II) titanate, CaFeTi 2 O 6 , have been synthesized at 12-15 GPa and 1200-1400°C, and studied by X-ray diffraction. This compound is a variant of the perovskite structure and crystallizes in the tetragonal space group P 4 2 / nmc , a = 7.5157(2) A, c = 7.5548(2) A, and Z = 4. Calcium and two iron atoms are ordered on three different A sites, with calcium in approximately 10-fold coordination, with one iron atom in tetrahedral coordination (Fe-O = 2.084(2)/A), and the other iron atom in square-planar coordination (Fe-O = 2.097(2) A). The system of octahedral tilts which this compound adopts has not been observed previously in a perovskite. The tilt system was described in a theoretical treatment of perovskites ( a + a + c - in the notation of A. M. Glazer ( Acta Crystallogr. Sect. B 28, 3384, 1972) and was (incorrectly) assigned to space group Pmmn.
Non-neuronal cells in the spinal cord of nude and heterozygous mice. II. Agranular leukocytes in the subarachnoid and perivascular space

The lumbar spinal cord of the athymic nude mouse and its heterozygous control were examined at the light and electron microscopic levels for differences in the cellular constituents of the sub-arachnoid and perivascular spaces. Both macrophages and lymphocytes were found in these spaces associated with the adventitial and leptomeningeal cells. Occasionally, fixed-cells were associated with extensions of the basal lamina and subjacent astrocytic processes. The appearance of the basal lamina of the externalglia limitans and perivascular space was enhanced by tannic acid treatment. There were twice as many macrophages as lymphocytes, but no significant strain differences. Comparison was made between cells in the lumina of incompletely perfused vessels and neuroglial cells in the spinal cord. The cellular morphology is distinct in each of these compartments and no cell migrations were observed between the blood, cerebrospinal fluid and C.N.S. interstitial space. The normal presence of both macrophages and lymphocytes in the subarachnoid and perivascular space suggests that these cells could penetrate the basal lamina and gain access to the C.N.S.
Non-differential conditioning of operant responding across a sound intensity continuum

Four groups of rats were conditioned to bar-press in the presence of either nine sound intensities, a single intensity, or no imposed sound field. The distribution of responding and the range of observed response rate are similar under these three conditions. No significant facilitative, suppressive or preferential effect upon responding was observed.
Intermittent ventilation in the hypoxic zone of western Long Island Sound during the summer of 2004

[1] Observations of dissolved oxygen (DO) concentration, salinity, and temperature, during summer of 2004, at three levels on two moorings in the area of western Long Island Sound that is prone to seasonal hypoxia are described. Ship surveys in the area reveal that the DO concentration below the pycnocline decreases at approximately 2.4 mM m−3 d−1 throughout the summer. We show that this is the net result of oscillations in the rate of change of the DO concentration with periods of 3 to 7 days. During intervals of declining DO concentration, the rate of change is consistent with previous estimates of the rate of community respiration. Since there is insufficient light for photosynthesis below the pycnocline, increasing DO concentration (ventilation) must be a consequence of either vertical mixing or horizontal advection from regions of higher concentration. Analysis of the covariation of DO, salinity, and temperature and knowledge of the mean property distributions allow us to associate most (∼80%) of the ventilation intervals with increased vertical mixing. Comparison of DO and wind stress measurements suggest that it is the component in the along-sound direction that controls the occurrence of ventilation, perhaps through modification of the rate of stratification by the density-driven circulation. We conclude that the spatial and temporal variability of vertical mixing is crucial to understanding the duration and extent of hypoxia in the Long Island Sound estuary.
An analysis of the economic rationale for public subsidization of sports stadiums.

Proposals to provide public subsidy to sports stadiums are being debated in many locales. This paper examines a number of types of benefits asserted by proponents of subsidies: direct municipal revenues from stadium events; multiplier benefits increasing income and sales in the area; the attraction of unrelated business activity; and, intangible benefits. The business attraction argument is subjected to empirical test with regression analysis. In only a small fraction of the cases examined does manufacturing activity in an SMSA correlate significantly with the presence of a new or renovated stadium. We conclude that measurable economic benefits to area residents are not large enough to justify stadium subsidies and that the debate must turn to immeasurable intangible benefits like fan identification and civic pride.
Pronunciability ratings of 319 CVCVC words and paralogs previously assessed for meaningfulness and associative reaction time

CVCVC (319) words and paralogs previously assessed for scaled-rated meaningfulness and associative reaction time were assessed for rated pronunciability following procedures used by Underwood and Schulz. The reliability correlation coefficient was.86. The r between pronunciability and meaningfulness was -.78; and the r between pronunciability and associative reaction time was.65. The validity of the assessment was based primarily on correlations between pronunciability values and performance data from a free-recall experiment and a recognition-memory experiment. The pronunciability values of a sample of 36 CVCVCs was found to be correlated with frequency of recall (r = −.41), and the pronunciability values of a second sample of 36 CVCVCs was found to be correlated with the frequency of recognition under three different measures of recognition memory: multiple choice (r =–.44), Shepard-Teghtsoonian (r =–.40), and embedded item (r =–.59).
Identification of gene expression profiles in rat ears with cDNA microarrays.

Abstract The physiological processes of hearing implicate thousands of molecules acting in harmony; however, their identities are only partially understood. We used cDNA microarrays containing 1,176 genes to identify >150 genes expressed in rat middle and inner ear tissue. Expressed genes covered several gene families and biological pathways, many of which have previously not been described. Transcription factor genes that were expressed included inhibitors of DNA binding protein (Id). These were localized to the spiral ganglion, organ of Corti and stria vascularis, and they are possibly involved in neurogenesis and angiogenesis. Transcriptional factors that were highly expressed included Gax (homeobox) and I-κB, which inhibit cellular proliferation. Their presence suggests that inhibitory programs for cell proliferation are enforced in the ear. Ion channel genes that were expressed included voltage-dependent L-type calcium channels (LTCC) and proton-gated cation channels (PGCC). Genes involved in neurotransmitter production and release included glutamic acid decarboxylase (GAD1). Genes involved in postsynaptic inhibition included neuropeptide Y5 receptors (NPY5) and GAD1. Due to the existence of receptors and/or enzymes involved in their biochemical synthesis, neurotransmitters associated with these might include serotonin, glutamide, acetylcholine, γ-aminobutyric acid (GABA), neurotensin, and dopamine.
THE STATUS OF CRIMINOLOGICAL RESEARCH IN THE FEDERAL GOVERNMENT

There is a general absence of criminological research within the federal government. Three reasons are advanced to this neglect: (1) criminol ogy is generally considered to be a developing and untried discipline; (2) the legal profession is viewed as encompassing the study of criminal behavior; and (3) the scientific investigation of deviant behavior is perceived as threatening to basic values of society. Following considera tion of impediments to the development of criminology, future prospects and directions for our discipline are discussed.
Medial prefrontal cortical innervation of the intercalated nuclear region of the amygdala

The projections of the infralimbic area (IL) of the medial prefrontal cortex to the intercalated nuclei (ICNs) of the amygdala are thought to form a critical component of the forebrain circuitry for fear extinction. Despite the importance of these projections, there have been no focussed anatomical studies that have investigated the extent of IL inputs to different portions of the ICN complex. The present investigation used anterograde tract tracing in the rat to study the projections of the ventromedial PFC, including the IL, to the ICNs and surrounding amygdalar regions. Immunohistochemistry for the μ-opioid receptor (MOR) was used to identify the ICNs. At rostral levels of the amygdala there was a very dense projection to a far lateral portion of the capsular subdivision of the central nucleus (CLC) located between the main and medial ICNs, but only very light projections to these ICNs and the lateral ICNs. This distinct portion of the CLC receiving strong IL inputs was termed the capsular infralimbic target zone (CITZ), and was MOR-negative. Likewise, at more caudal levels of the amygdala, IL projections to the medial, lateral, and dorsal ICNs were light to moderate compared with projections to adjacent portions of the basolateral amygdala and amygdalostriatal transitional area. These findings suggest that the putative role of the IL-to-ICN connection in fear inhibition may be mediated by light to moderate projections from the IL to the medial ICN, and that the CITZ may be an equally important amygdalar target for this function.
Semi-micro cryoscopic molecular weight determination with a thermistor thermometer

Abstract An apparatus for extending the steady state freezing point depression method to small volumes, of the order of 0.3 or 0.4 ml, has been developed. A thermistor is used as the temperature sensing element, in one arm of a Wheatstone bridge. The apparatus is simple and dependable. Accuracies in the order of 2% are easily attainable.
Pseudo-Hierarchical Ant-Based Clustering

The behavior and self-organization of ant colonies has been widely studied to address distributed clustering. However, most models that directly mimic ants produce too many clusters and converge too slowly. A wide range of research has attempted to address this through various means, but a number of sources of inefficiency remain, including: i) ants must physically move from one cluster to another through intermediate locations, ii) patterns in movement among clusters is not considered, and iii) while some approaches have included bulk item movement, they do not provide efficient movement while still maintaining the self-organizing nature of ant-based clustering. To address these issues, this paper presents a new algorithm for ant-based clustering. Here ants maintain a movement zone around each cluster, keeping ants close to data items. These movement zones are used to elect representatives that are responsible for all long distance movement. Representatives can, probabilistically, pass an object it has to any other representative. Since each cluster has approximately one representative at any given time, the search space for placing items over a long distance is reduce to the number of clusters. This provides an infrastructure that allows bulk movement and efficient long distance merging.
Expression of the Costimulatory Molecule BB-1, the Ligands CTLA-4 and CD28, and their mRNA in Inflammatory Myopathies

To examine if the muscle fibers in patients with inflammatory myopathies have the potential to behave as antigen presenting cells (APCs), we investigated the expression of costimulatory molecules BB-1, B7-1 (CD80), and B7-2 (CD86), and their counterreceptors, CD28 or CTLA-4 (CD152), in the muscle biopsies of patients with polymyositis (PM), PM associated with human immunodeficiency virus infection (HIV-PM), sporadic inclusion body myositis (s-IBM), dermatomyositis (DM), and normal or disease controls. The expression of the B7 family of molecules on the muscle fibers was limited to BB-1. In PM, HIV-PM, and s-IBM, but not the disease controls, the nonnecrotic, MHC-class I-expressing muscle fibers, invaded or not by CD8+ T cells, had prominent membrane expression of BB-1. Several of the BB-1-positive fibers bound strongly in a cell-to-cell contact with their CD28 or CTLA-4 ligands on the autoinvasive CD8+ T cells, as confirmed by confocal microscopy. By reverse transcription-polymerase chain reaction, the expression of CD28 and CTLA-4 was up-regulated in PM, HIV-PM, and s-IBM, but not the controls. Because the BB-1-positive fibers expressed MHC-class I antigen and bound to up-regulated counterreceptors CD28 and CTLA-4 on the autoinvasive CD8+ T cells only in PM, HIV-PM, and s-IBM, the BB-1 molecule in these diseases should have a functional role in antigen presentation and T cell differentiation. These findings complement recent studies and suggest that in PM, HIV-PM, and s-IBM the muscle fibers are not only targets of CD8+ cytotoxic T cells but may also behave as “professional” APC.
Auto and Cross-Bispectral Analysis of a System of Two Coupled Oscillators With Quadratic Nonlinearities Possessing Chaotic Motion

Auto and cross-bispectral analyses of a two-degree-of-freedom system with quadratic nonlinearities having two-to-one internal (autoparametric) resonance are presented. Following the work of Nayfeh (1987), the method of multiple scales is used to obtain a first-order uniform expansion yielding four first-order nonlinear ordinary differential equations governing the modulation of the amplitudes and phases of the two modes. The particular case of parametric resonance of the first mode considered in this paper admits Hopf bifurcations and a pure period doubling route to chaos. Auto bicoherence spectra isolate the phase coupling between increasing numbers of triads of Fourier components for a pure period doubling route to chaos for the individual degrees-of freedom. Cross-bicoherence spectra, on the other hand, yield information about the phase coupling between the two degrees-of-freedom. The results presented here confirm the capacity of bispectral techniques to identify a quadratically nonlinear mechanical system that possesses chaotic motions. For the chaotic case, cross-bicoherence spectra indicate that most of the nonlinear energy transfer between the modes is owing to cross-coupling between phase modulations rather than between amplitude modulations.
Standards and Equity

(2004). Standards and Equity. Journal of the Learning Sciences: Vol. 13, No. 2, pp. 237-242.
Useful coordinate transformations for antenna applications

General coordinate transformations which are commonly encountered in many antenna applications are presented. Neither the feed coordinates nor the far-field pattern coordinates in general coincide with the antenna coordinates. Transformations discussed allow one to relate the spherical and Cartesian components of one system to the spherical and Cartesian compoents of the other system. In particular, attempts are made to use unified notations to assist the reader in a straightforward application of the transformations.
THE NATURE OF GROWTH DEPRESSIONS IN SUNFLOWER CAUSED BY VESICULAR-ARBUSCULAR MYCORRHIZAL INFECTION

Summary When mycorrhizal (M) and non-mycorrhizal (NM) plants were grown in a soil of low phosphorus (P) availability (5 μg g−1), mycorrhizal infection caused a transient depression in leaf area relative to NM plants that lasted for seven to eight weeks. When plants were grown in this same soil with added P, leaf areas of M and NM plants were similar. When plants were grown in a soil of moderate P availability (15 μg g−1), infection decreased leaf area throughout the experiment. High soil P levels were associated with lower degrees of infection. The degree of infection was positively correlated with the degree of depression of leaf area while the soil P level was negatively correlated with the ability to overcome the initial depression. When M and NM plants were grown in the soils of either low or moderate P availability, the relationship between relative leaf expansion rate (RLER) and tissue P concentration was the same for M and NM plants. Also, mycorrhizal infection did not affect plant N concentration to the same degree as it did P concentration. When grown in the soil of low P availability, dry matter in the shoot was shown to be partitioned differently for M and NM plants. M plants in vested mo re dry matter in leaves relative to stems compared to NM plants. Phosphorus-amended NM plants also invested more dry matter in leaves relative to stems compared to unamended NM plants. Because of the possible difference in leaf dry weight: stem dry weight ratio between M and NM plants, final harvest shoot dry weights were not an adequate measure of the physiological status of the plants. Leaf expansion was shown to be a good indicator of M effects on plant growth.
“IDEAL” vaccines for resource poor settings

In developing countries, immunization delivery would be more efficient, safer and economical if all vaccines could elicit long-term protection following needle-free administration of just a single dose and without need for a cold chain, and if immunization left an indelible (e.g., serologic) marker that would identify immunized persons. A few existing vaccines (e.g., yellow fever, measles) confer long-term protection following a single dose. To accomplish the same with less immunogenic live vaccines and with non-living antigens, potent (parenteral and mucosal) adjuvants are required. Emerging knowledge of how the innate immune system modulates adaptive immune responses is guiding development of modern adjuvants that can markedly enhance immune responses to vaccines by selective stimulation of components of the innate immune system. Needle-free immunization can be accomplished by administering vaccines via mucosal (oral or nasal) or transcutaneous routes or by parenteral injection using needle-free injection devices. Technologies such as vitrification (treatment with trehalose followed by drying) render vaccines resistant to temperature extremes. Ideally, immunization would lead to a biomarker such as a specific vaccine-derived antibody that allows differentiation of successfully immunized persons from susceptibles.
GENETIC VARIATION AND POLYMORPHISM IN THE INDUCIBLE SPINES OF A MARINE BRYOZOAN.

Of particular value in understanding the evolution of genotypes with broad phenotypic ranges (phenotypic plasticity) are the few examples of organisms with adaptive plasticity, such as those that develop a defensive morphology in response to cues from predators. We know little about the heritability of inducible defensive characters or the range of phenotypes available for selection to act on in the field. Membranipora membranacea is a colonial marine bryozoan that produces spines within two days of exposure to waterborne predator extracts. Surveys done in 1993 and 1995 showed that the population at Friday Harbor Labs, Washington, was polymorphic for inducible spine type and was composed of a constitutively spined type that produced spines in the absence of a predator stimulus, an unspined phenotype that did not produce spines irrespective of a stimulus, and an inducibly spined phenotype that would produce spines if exposed to the appropriate cue. In 1995, the frequencies of these types were determined through a laboratory common-garden experiment; 178 colonies were cultured from metamorphosis through approximately 30 days and then exposed to the cue. The inducible type was the dominant, comprising 80.3% of the population. The constitutive type made up 6.2% of the population, and the remaining 13.4 % was the unspined type. The frequency of the three types was similar to a preliminary trial of the experiment run in 1993. Experiments also showed that the lengths of the spines of the inducible type varied continuously among genotypes. To assess causes of variation in the inducible spine response and its clonal heritability, 16 clones were subdivided and grown in a common environment and exposed to a single dosage of spine inducing substance (SIS). Spine length showed high clonal heritability. The range of colony responses from a single environment varied from relatively unresponsive to highly responsive colonies with a very low threshold of response. Norms of reaction were quantified for spine lengths of inducible genotypes originating from two field environments by testing them in a concentration series of SIS. Both spine length and spine type varied with concentration of inducer. Within a clone, colonies were more likely to produce membranous spines than corner spines at higher concentrations. At low concentrations, only straight spines were produced. This study showed that populations of M. membranacea at Friday Harbor are a mix of inducible, nonspined and constitutively spined individuals. Even the inducible individuals showed high heritable variation in the length of spine activated, suggesting that there is considerable scope for the evolution of this character. A norm-of-reaction experiment further showed that the type of spine produced, membranous or corner, varied with the concentration of the cue. Factors maintaining the polymorphism and the broad range of genotypes could include high costs of defending the spined types coupled with a shifting biotic regime.
Structure of oceanic core complexes: Constraints from seafloor gravity measurements made at the Atlantis Massif

[1] Using the DSV Alvin, the relative seafloor gravimeter ROVDOG was deployed at 18 sites on the Atlantis Massif (located at the ridge-transform intersection of the Mid-Atlantic Ridge and the Atlantis Transform Fault near 30°N, 42°W). These data along with previously collected shipboard gravity and bathymetry provide constraints on the density structure of this oceanic core complex. A series of quasi 3-D forward models suggests that symmetric east and west-dipping density interfaces bound the core of the massif with dip angles of 16°–24° in the east and 16°–28° in the west, creating a wedge with a density of 3150–3250 kg/m3. The dip angle in the east is steeper than that of the surface slope, suggesting that the detachment fault surface does not coincide with the density boundary. The resulting low-density layer is interpreted as a zone of serpentinization.
Cure characterization of carbon fiber reinforced phenyl-ethynyl terminated oligoamic acid by FTIR–photoacoustic spectroscopy

Abstract Curing of phenyl-ethynyl terminated oligoamic acid resin reinforced with carbon fiber and of the neat extracted resin was investigated by FTIR–photoacoustic spectroscopy (PAS). Imidized oligoamic acid with phenylethynyl termination form the precursor for the formation of phenyl-ethynyl terminated imide (PETI), which are employed for high temperature, high performance applications. The reaction kinetics was modeled based on two-stage, first order kinetic model for the imidization process, whereas the crosslinking was modeled on a simple first order model. Our results show that the imidization is kinetically controlled, whereas the crosslinking stage exhibits kinetic and diffusion controlled phases. The activation energy for the PETI composite and resin crosslinking was calculated to be 22.6 and 23.2 kcal/mol, respectively. Variation in rates for resin and composite are discussed. The cure extent as determined by isothermal DSC and by FTIR–PAS measurements were found to be in good agreement.
On the Capacity of Randomly Used Shared Channels

The channel capacity of a communication channel made available to a user on a shared basis with other users is here considered. An overall system bandwidth B is divided into segments and parceled out to subscribers in an overlapping manner. Viewing emissions by the sharing user as Gaussian noise, the channel capacity is treated as a random variable, and its probability function, mean, and variance are studied. For a fixed power to each user, it is found that the average capacity of a user is maximum when the number of multiple assignments of a frequency band is approximately the inverse of the probability of use. The increase in channel capacity over exclusive assignment is also determined. The probability function of the capacity is worked out for some specific case to show its dependence on the frequency assignment policy, and a general procedure for determining the probability function is given.
The alkaline proteases of Argiope—II. Fractionation of protease activity and isolation of a silk fibroin digesting protease

1. 1. The protease activity of digestive fluid from the spider Argiope aurantia was separated into four major fractions by ion exchange chromatography. 2. 2. The protease activity of each fraction was inhibited by specific metal ions and EDTA. Other metal ions reversed the chelator inhibition of these proteases. 3. 3. The four protease fractions exhibited different substrate specificity when assayed with casein, elastin and several synthetic ester substrates. 4. 4. Two of the protease fractions were uniquely able to hydrolyze the generally protease-resistant large ampullate silk fibroin of spiders orb web. 5. 5. One of the fibroin-digesting proteases termed Argiope protease B was purified to electrophoretic homogeneity by hydroxyapatite chromatography.
Microsensors for health monitoring of smart structures

Health monitoring of structural systems has gained a lot of interest in recent times. In this paper, we consider the wireless data acquisition for health monitoring of smart structures. Some of the work done towards development of micro sensors for wireless health monitoring of smart structures is presented. The concept of smart sensors is demonstrated with the help of commercially available micro controller and wireless Rx/Tx modules. Application of these smart sensors in health monitoring is also demonstrated on a laboratory set up. A subspace system identification method known as N4SID is used for getting the state space matrices of the nominal and the damaged systems. The concepts are demonstrated on simple test article. Finally, the future goals in the development of micro sensors are given.
Progress in fractionation procedures. II. Distillation, sublimation, and crystallization: 1959, 1960

Abstract The present summary of progress in these areas is intended to include all those publications which have appeared since the previous review.1 It is limited, as before, to improved techniques or apparatus for carrying out, these procedures on a small scale, that is at or below what Cheronis2 has called semi-micro, dealing as a rule with amounts of material of less than 1 g. A number of items listed by Francis3 in his review of Equipment and Tools for 1960 will be briefly evaluated here, for the sake of completeness.
Heat-transfer experiment in marine pelagic clay: Implication for subseabed disposal of high-level radioactive waste and contact metamorphism in the Guaymas Basin, Gulf of California

Abstract A heat-transfer experiment has been conducted in marine pelagic clay to provide data to model geomechanical and geochemical properties of seabed sediment exposed to a relatively large thermal gradient and sea-floor pressure. This experiment entailed emplacement of a resistance-type heat source in the center of a tank of sediment (1 m3) from the central North Pacific and overlain by a reservoir (2 m3) of artificial seawater. The system was pressurized to 500 bar. Pore-fluid samples extracted from sediment at 5–150°C and samples of sediment altered at temperatures from ∼ 30° to 270°C yield information on mass transport and sediment alteration processes. Sediment alteration in the vicinity of the heat source caused an increase in sediment shear strength, water and Na2O contents, and formation of hydrated analcime at the expense of kaolinite and quartz. This so-called “baked” zone consisted of sediments altered at temperatures of > 170°C. The high Na2O contents of baked-zone sediments require additions of Na+ in amounts exceeding that that available in pore fluid alone and suggest convective circulation of sea-salt solution along the relatively permeable boundary between the sediment and the heat probe. Quartz dissolution and removal of SiO2 by convectively circulating sea-salt solution, moreover, played an important role in microcrack extension and permeability enhancement in the baked zone, itself. Mineralogic and chemical changes in baked-zone sediment provide useful insight into the mechanism of alteration of hemipelagic sediments in contact with dolerite sills in the Guaymas Basin, Gulf of California. Sediment exposed to temperatures of Application of results from the heat-transfer experiment to the subseabed disposal concept shows that thermal diffusion will dominate near-field mass transport, provided sediments remain relatively unconsolidated and impermeable and are not affected by convection. Assuming convection does not occur, or if it does, is localized and closed to recharge pathways, pH at temperatures of > 250°C will most probably be mildly acidic. The redox intensity (fO2) will be constrained by sediment chemistry and mineralogy.
Adaptive control in economics

The following definition of Economics is given by P. A. Samuelson: "Economics is the study of how men and society choose, with or without the use of money, to employ scarce productive resources, which could have alternative uses, to produce various commodities over time and distribute them for consumption, now and in the future, among various people and groups in society." Thus the study of economics is related to that of allocating scarce resources for alternative uses. This motivates the use of mathematical optimization techniques in economic problems such as consumer behavior, planning of production and inventory, economic growth, portfolio selections and many other things. The use of control theory seems to be a natural extension when one is interested in investigating the effect of certain changes on the whole motion or behavior over time of the economic system under investigation. When there are random variables or stochastic processes which may be involved in the economic system, the methods of stochastic control would seem to be appropriate. In the study of economics, one important class of problems is that of investigating the effects of a change (sometimes in an unknown way) in some internal parameter on the behavior of the system over time. For such a study, the concepts and methods of adaptive control are extremely valuable.
The dynamics of knowledge assets and their link with firm performance

Purpose – Organizational knowledge assets have been identified as sources of competitive advantage. It is therefore critical that organizations understand how they impact on performance in order to effectively manage these assets. This paper aims to extend the “knowledge‐value chain”, recently introduced in the management literature, by integrating the concept of dynamic capabilities. Based on a systematic review of the literature it seeks to demonstrate the important role of dynamic capabilities in the relationship between knowledge asset management and firm performance. This paper aims to argue that the effective management of knowledge asset enhances the value of organizational competencies, which in turn support organizational processes, products and services. Dynamic capabilities take the role of continuously shaping operating routines and competencies, and consequently deliver superior long‐term performance.Design/methodology/approach – The central objective of the article is to extend the work pres...
QCD space-time analysis of quarkonium formation and evolution in hadronic collisions

The production of heavy quarkonium as Q{bar Q} bound states in hadron-hadron collisions is considered within the framework of a space-time description, combining parton-cascade evolution with a coalescence model for bound-state formation. The {open_quotes}hard{close_quotes} production of the initial Q{bar Q}, directly or via gluon fragmentation and including both color-singlet and color-octet contributions, is calculated from the perturbative QCD cross sections. The subsequent development of the Q{bar Q} system is described within a space-time generalization of the Dokshitzer-Gribov-Lipatov-Altarelli-Parisi parton-evolution formalism in position and momentum space. The actual formation of the bound states is accomplished through overlap of the Q{bar Q} pair and a spectrum of quarkonium wave functions. This coalescence can only occur after sufficient gluon radiation reduces the Q{bar Q} relative velocity to a value commensurate with the nonrelativistic kinematics of these bound systems. The presence of gluon participants in the cascade then is both necessary and leads to the natural inclusion of both color-singlet and color-octet mechanisms. The application of this approach to pp (p{bar p}) collisions from {radical} (s) = 30 GeV{endash}14 TeV reveals very decent agreement with available data from the CERN Intersecting Storage Rings and Fermilab Tevatron{emdash}without the necessity of introducing fit parameters. Moreover, production probabilitiesmore » are calculated for a complete spectrum of charmonium and bottomonium states, with the relative significance compared to open charm (bottom) production. An analysis of the space-time development is carried through which sheds light on the relevance of gluon radiation and color structure, suggesting a corresponding experimental investigation. {copyright} {ital 1998} {ital The American Physical Society}« less
Paternal care paradoxically increases offspring seizure susceptibility in the El mouse model of epilepsy.

Abstract The El mouse is a model of idiopathic epilepsy in which seizures emerge on Postnatal Days (PNDs) 80–90, although time to first seizure can be modified by experiential factors including handling during development and history of past seizures. This study tested the hypothesis that a significant increase in the amount of parental investment would impact seizure susceptibility in adult El offspring. The study used a single dam control, in which the litter was reared by a female biological parent, and a biparental experimental group, in which both biological parents reared the litter. Components of parental care and pup body weights were quantified on PNDs 2–21, and adult offspring were examined using a handling-induced seizure susceptibility (HISS) test on PNDs 80–90 to assess the long-term impact of alterations in the perinatal environment. As expected, presence of both parents did increase parental/pup contact time by 350% relative to single-mother parenting and also reduced body weight, an index of perinatal stressor exposure, in already underweight El offspring. Accordingly, HISS testing of adult El offspring revealed a deleterious effect of biparental rearing, which increased seizure incidence to 30% relative to 0% for the single dam condition. These results suggest that the presence of a second care provider in addition to the dam constitutes a form of stressor exposure in El pups and, as a consequence, reduces the time to first seizure in genetically susceptible offspring.
A Reconceptualization of Values Clarification: Values Conflict Resolution

Values Clarification (VC) waxed during the 1970s and waned during the 1980s. Today, psychology lacks an empirically based intervention for helping individuals to clarify their values. In this article, the meteoric rise and then precipitous decline of VC are first described. Conservative religious and political criticisms as well as conceptual flaws within VC are discussed. A reconceptualization of VC that addresses the criticisms and flaws is then proposed. The goal of the reconceptualization is to revitalize the topic of values conflict and clarification, to stimulate a new generation of research, and to establish an empirically based guidance for practice.
Evidence for the Goldhaber effect in pp interactions at 300 GeV/c☆

Abstract We have observed evidence for the Goldhaber effect among pion pairs produced in six- and eight-prong events in pp interactions at 300 GeV/ c . We observe a pronounced difference between the opening angle distributions for pairs of pions of like and unlike electric charge. This effect decreases rapidly with increasing all-charged pion mass. Calculations indicate that resonance production can account for only about 30% of the observed effect. A search for the Goldhaber effect in high-charged-multiplicity events ( n c ⩾ 20) gives only inconclusive results.
Ejection of pulsars and binaries to the outskirts of globular clusters

THREE-BODY interactions can eject stars, singly or in binaries, from the core of a globular cluster to its outskirts, whither dynamical friction may take more than 10^8 yr to return them. We show here that such a process can explain why the binary pulsar 2127 + 11C in the cluster Ml5 (and perhaps 1744–24A in Terzan 5) is now far from the cluster core. A suitable encounter could have given the pulsar enough velocity to eject it to its present position, and also replaced its original stellar companion with a neutron star. For ejection of PSR2127 +11C to be likely, the core of M15 must be composed of heavy degenerate stars at a density greater than 10^7pc^(-3), maintained for ≳10^8yr; this is consistent with previous dynamical estimates. A natural combination of factors enables us to see 2127 + 11C: a binary of longer period could not have received a large enough impulse to escape the core, whereas one of shorter period would have been ejected from the cluster or would have collapsed because of orbital decay by gravitational radiation. Pulsars and pulsar binaries ejected from clusters will contribute to the birth rate of recycled pulsars in the inner Galaxy.
Evaluation of renal function with contrast MRI: mathematical modeling and error analysis

Dynamic MR imaging with contrast media is increasingly used to provide a safe and noninvasive assessment of renal function. Following intravenous injection of a paramagnetic tracer such as Gd-DPTA, the time course of MR signal is measured in arterial blood and in the kidneys. We use mathematical modeling and Monte Carlo trials to evaluate errors in computed renal parameters such as mean transit time (sigma) m as a function of injected dose. The model assumes that tracer concentration in the renal compartments is the result of convolution of the arterial curve and unit response functions. Results indicate that (sigma) m is not a monotonic function of the dose: instead it reaches a minimum for 2.5 - 3.5 ml of 500 mmol/l solution of Gd-DPTA and it rapidly increases for doses lower than 1 ml. These results can help optimize MR protocol and establish the feasibility of MR measurements using reduced doses of Gd-DPTA.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.