cssi/SciSciGPT-SciSciNet huggingface dataset:
Stability properties of autonomous homogeneous polynomial differential systems

Abstract A geometrical approach is used to derive a generalized characteristic value problem for dynamic systems described by homogeneous polynomials. It is shown that a nonlinear homogeneous polynomial system possesses eigenvectors and eigenvalues, quantities normally associated with a linear system. These quantities are then employed in studying stability properties. The necessary and sufficient conditions for all forms of stabilities characteristic of a two-dimensional system are provided. This result, together with the classical theorem of Frommer, completes a stability analysis for a two-dimensional homogeneous polynomial system.
Language ideologies and practices in (en)gendering the Basque nation

This article argues that an androcentric Basque nationalist pedagogy is enacted in secondary schools in San Sebastian (Donostia), Spain. Textbooks present men as the exemplary Basque speakers and cultural agents by erasing women's contributions to Basque language and culture. Schools also contribute to a recursive language ideology, linking “authentic” ethnic identity, “naturalness,” and solidarity with vernacular Basque, of which the most pragmatically salient marker is the familiar form of address hi. Hi, in turn, indirectly indexes male speakers and masculinity, thereby creating an iconic relationship between authentic Basque identity, Basque culture, and masculinity. However, many women in Basque society have challenged this male privilege in various domains, thereby opening up the possibility of a Basque nation that embraces its female as well as its male members. As such, the Basque case has interesting implications for theorizing the relationships among language, gender, and nation.
Net energy: still a (mostly) irrelevant, misleading and dangerous metric

Classical net energy analysis does not define “net energy” as Dr. Pimentel has defined it. Classical net energy analysis has limited value. Dr. Pimentel's use of net energy to attack biofuels is irrelevant, misleading and even dangerous in a world struggling to find alternatives to petroleum. © 2008 Society of Chemical Industry and John Wiley & Sons, Ltd
Mammographic follow up: a vital component of breast cancer management.

Women with proven breast cancer are at high risk for development of a second breast malignancy or a recurrence. An important component of clinical care is regular mammographic follow up, to enable pre-clinical diagnosis and avoid delay in treatment. One hundred and forty-two women with previous breast cancer attended a pilot mammographic screening program. Eleven had suspicious mammographic lesions, all clinically occult; nine breast cancers were diagnosed (two recurrences and seven new tumours). The cancer detection rate in this high-risk group of women was 6.3%, compared with 0.8% in 16 283 women screened with no history of breast cancer. Examination of the mammographic history of the 142 women showed that mammography was used infrequently as part of their clinical surveillance, and this led to a delay in diagnosis of the new or recurrent cancer. Recommendations for an appropriate regimen for use of mammography in new and established cases of breast cancer are made.
Spectrum of light emitted from ZnCdS: Ag screens excited by an electron beam

The emission spectrum of a ZnCdS: Ag phosphor screen excited by an electron beam was measured for different screen's thickness. This spectrum is found to be shifted towards the longer wavelengths when the screen thickness increases. The matching factor a between screen and some commercial photocathodes, which alter because of this shifting, is given as a function of the screen thickness.
Estrogen regulation of lactoferrin expression in human endometrium.

PROBLEM : Lactoferrin is an iron-binding glycoprotein that has been shown to be overexpressed in human endometrial carcinomas. The purpose of our present study is to investigate the possible role of estradiol in the expression of lactoferrin. METHOD OF STUDY : We investigated 1) serum levels of lactoferrin in five women during normal ovulatory cycles, 2) serum levels of lactoferrin during ten human menopausal gonadotropin induced cycles when estradiol levels are high, and 3) lactoferrin expression in five proliferative and five secretory phase endometrium by immunohistochemical studies. The serum concentrations of lactoferrin were measured by a peroxidase-based enzyme-linked immunosorbent assay. RESULTS : In normal ovulatory cycles, the mean serum lactoferrin concentration during the proliferative phase (0.4013 ± 0.0242 μg/mL) was significantly higher (P<0.02) than in the secretory phase (0.3468 ± 0.0209 μg/mL). In induced cycles, there was gradual increase in lactoferrin levels with increasing estradiol concentrations. Peak lactoferrin levels in induced cycles (0.7495 ± 0.1148 μg/mL) were significantly higher (P<0.003) than the midcycle levels (0.423 ± 0.0424 μg/mL) in normal cycles. Immunohistochemical analysis of the endometrium revealed greater expression of lactoferrin in proliferative endometrium (50.7 ± 13%, range 28-72%) than in secretory endometrium (19.2 ± 4%, range 7-31%). CONCLUSION : These results indicate that estradiol may play a role in the regulation of lactoferrin expression in human endometrium.
Libraries and library automation in Europe: introduction to the special issue of Library Hi Tech

The European Union (EU) has provided significant financial support and motivation in creating links among Europe's major libraries and in enabling the region's poorer countries to develop needed technical infrastructures needed by their libraries. EU Parliament authorized the Libraries, Networking, and Telematics section to support “Collaboration between libraries in the field of data processing.” From 1990 to 1994, 51 projects were funded and in 1996 an additional 21 received support. Two recent activities are of particular interest. The European Research Consortium for Informatics and Mathematics brings together computer scientists and other information specialists from the national laboratories of 13 European countries. ERCIM's scientists possess substantial expertise relevant to digital library development, and they have submitted a proposal to the EU directorate to create a pan‐European digital library that initially will enable exchange of their own technical reports. A second activity, called INFO2...
Suppressing irrelevant information: knowledge activation or inhibition?

In 3 experiments, the authors examined the role of knowledge activation in the suppression of contextually irrelevant meanings for ambiguous homographs. In Experiments 1 and 2, participants with greater baseball knowledge, regardless of reading skill, more quickly suppressed the irrelevant meaning of ambiguous words in baseball-related, but not general-topic, sentences. Experiment 3 demonstrated that participants with greater general knowledge, regardless of reading skill, more quickly suppressed the irrelevant meaning of the ambiguous words in general-topic sentences. As predicted by D. S. McNamara's (1997) knowledge-based account of suppression, ambiguity effects are influenced by greater activation of knowledge related to the intended meaning of the homograph. These results challenge inhibition (e.g., M. A. Gernsbacher, K. R. Varner, & M. Faust, 1990) as the sole mechanism responsible for the suppression of irrelevant information.
The surface stability of polymers with adsorbed fibronectin.

Linear low-density polyethylene (LLDPE), polypropylene (PP), polystyrene (PS), and polyethylene-co-ethacrylic acid (PE-EAA, 17.5% acid content) films were treated with an aqueous solution of fibronectin. Advancing contact angles of water (straight theta(a)) were used to monitor the change in the surface wettability of these films. With the exception of PE-EAA, all of the samples showed an increase in their wettability by water, indicating that the protein had adsorbed to the polymer surface. The stability of these protein-modified films against a buffered aqueous solution and against air under ambient conditions was monitored over time. The surface wettability of these protein-modified polymers, with the exception of PS, remained unchanged after heating against the buffer solution. In air, however, straight theta(a) increased over a period of 2 months. In addition, the effect of organic solvent extraction on the surface stability of these protein-modified films was investigated. Unmodified samples of LLDPE, PS, and PP were subjected to soxhlet extraction to remove impurities and low-molecular-weight oligomers prior to film preparation and subsequent treatment with fibronectin. These samples were left in air under ambient conditions for 2 months. There was no difference in the magnitude of the change in straight theta(a) for the protein-modified, extracted LLDPE film compared to the protein-modified, nonextracted polymer film. A slight decrease in the rate of thermal reconstruction was observed for the protein-modified extracted PS film compared to the protein-modified nonextracted sample, and a slight increase in the rate of thermal reconstruction was observed for the protein-modified extracted PP film compared to the protein-modified nonextracted sample.
Reproductive Capacity of Dairy Bulls. I. Technique for Direct Measurement of Gonadal and Extra-Gonadal Sperm Reserves

Summary A technique for determining the gonadal and extra-gonadal sperm reserves of bulls by direct counting is described. Sperm were liberated from the epididymis by thoroughly tearing apart the tissue in 50ml. of 0.9% NaCl and grinding the tissue suspension in 200 to 500ml. of saline for a total of 2.5min. in a Waring Blendor. After removing the tunica albuginea, testicular sperm were liberated by cutting the testis into small pieces and grinding in 1,000ml. of saline for 2min. Sperm were liberated from the ductus deferens and ampulla by flushing with distilled water to remove most of the sperm and then grinding in a blendor. Soaking the sperm suspensions for 48 hr. before counting did not result in higher values; differences between 0- and 48-hr. counts were relatively small. Sampling of the sperm suspension is the major source of error; therefore, replicate counts should be made on separate subsamples of the entire suspension.
Trends in the Transitory Variance of Male Earnings: Methods and Evidence.

We estimate the trend in the transitory variance of male earnings in the United States using the Michigan Panel Study of Income Dynamics from 1970 to 2004. Using an error components model and simpler but only approximate methods, we find that the transitory variance started to increase in the early 1970s, continued to increase through the mid-1980s, and then remained at this new higher level through the 1990s and beyond. Thus the increase mostly occurred about 30 years ago. Its increase accounts for between 31 and 49 percent of the total rise in cross-sectional variance, depending on the time period.
Synthesis and Characterization of an Air-Stable Gallium Hydride, [t-Bu(H)Ga(μ-NEt2)]2, and Related Chloride Derivatives

The synthesis of [t-Bu(H)Ga(μ-NEt2)]2 (1) was accomplished by the addition of 4 t-BuLi to [Cl2Ga(μ-NEt2)]2. Evidence suggests that two tert-butyl groups are lost as isobutylene and result in Ga−H b...
An effective quasi-one-dimensional description of a spin-1 atomic condensate

Within the mean field theory we extend the effective quasi-one-dimensional nonpolynomial Schr\"odinger equation (NPSE) approach to the description of a spin-1 atomic condensate in a tight radial confinement geometry for both weak and strong atom-atom interactions. Detailed comparisons with full time-dependent 3D numerical simulations show excellent agreement as in the case of a single component scalar condensate, demonstrating our result as an efficient and effective tool for the understanding of spin-1 condensate dynamics observed in several recent experiments.
Sensory and compositional attributes of melting- and non-melting-flesh peaches for the fresh market

A study was conducted to determine differences in sensory and compositional characteristics of melting-flesh (MF) and non-melting flesh (NMF) fresh market peach genotypes. Sensory results showed that the NMF fruit ('Oro A' and FL 86-28C) were 'harder', less 'juicy' and more 'rubbery' than their MF (FL 90-20 and 'TropicBeauty') counterparts. A principal component analysis of the sensory data showed a clear distinction between the textural aspects of MF and NMF fruit, but not between their flavour aspects. Likewise, chemical analysis showed that while differences in pH, titratable acidity, and soluble solids were detected among the four genotypes, no consistent grouping could be made based on the MF/NMF nature of the fruit.
Acoustic Emission During Athermal Martensitic Transformation in Steels

A relationship developed earlier between acoustic emission signals and the process of athermal martensitic transformation based on the free energy associated with the process is extended and verified experimentally. The relationship is found to model the process characteristics very well. The intensity of AE signal generated during transformation was found to be proportional to the temperature derivative of the fraction of martensite, the cooling rate, and volume of specimen. The AE signal was also found to be related to the carbon content of the steel. During transformation, the signal intensity was found to increase to a peak, and then tail off near the end of the transformation. Values of the martensite start temperature obtained from plots of the total RMS squared AE signals were also found to correlate well with values from the literature.
Attenuation of morphine antinociceptive tolerance by a CB1 receptor agonist and an NMDA receptor antagonist: interactive effects

Abstract CB 1 cannabinoid (CB 1 ) receptor agonists and N -Methyl- d -Aspartate (NMDA) receptor antagonists attenuate the development of morphine antinociceptive tolerance. The present study used dose-addition analysis to evaluate CB 1 /NMDA receptor interactions on this endpoint. Chronic morphine administration (5 days, 100 mg/kg, twice daily) resulted in a 2.8-fold rightward shift in the morphine dose-effect curve. Co-administration of either the CB 1 receptor agonist CP-55940 (5-(1,1-Dimethylheptyl)-2-[5-hydroxy-2-(3-hydroxypropyl)cyclohexyl]phenol; 0.32–1.0 mg/kg) or the NMDA receptor antagonist (−)-6-phosphonomethyl-deca-hydroisoquinoline-3-carboxylic acid (LY235959; 1.0–3.2 mg/kg) with morphine dose-dependently attenuated morphine tolerance. The relative potency of each drug alone was quantified using a defined level of effect (one-quarter log shift in the morphine dose-effect curve), resulting in equieffective doses of 0.42 mg/kg and 1.1 mg/kg for CP-55940 and LY235959, respectively. Subsequent experiments assessed CP-55940/LY235959 interactions using a fixed-proportion design. Co-administration of CP-55940/LY235959 mixtures (1:1, 1:3.2, or 1:10 CP-55940/LY235959) with morphine dose-dependently attenuated morphine tolerance. Isobolographic and dose-addition analysis were used to statistically compare the experimentally determined potency for each mixture ( z mix ) with predicted additive potency ( z add ). Mixtures of 1:1 and 1:3.2 CP-55940/LY235959 produced additive effects ( z add = z mix ), while the mixture of 1:10 CP-55940/LY235959 produced a supra-additive effect ( z add > z mix ). These results suggest that CP-55940 and LY235959 produce additive or supra-additive attenuation of morphine antinociceptive tolerance after repeated morphine administration, depending on their relative concentrations.
Constitutive PKA activity is essential for maintaining the excitability and contractility in guinea pig urinary bladder smooth muscle: role of the BK channel

The elevation of protein kinase A (PKA) activity activates the large-conductance voltage- and Ca2+-activated K+ (BK) channels in urinary bladder smooth muscle (UBSM) cells and consequently attenuates spontaneous phasic contractions of UBSM. However, the role of constitutive PKA activity in UBSM function has not been studied. Here, we tested the hypothesis that constitutive PKA activity is essential for controlling the excitability and contractility of UBSM. We used patch clamp electrophysiology, line-scanning confocal and ratiometric fluorescence microscopy on freshly isolated guinea pig UBSM cells, and isometric tension recordings on freshly isolated UBSM strips. Pharmacological inhibition of the constitutive PKA activity with H-89 or PKI 14–22 significantly reduced the frequency and amplitude of spontaneous transient BK channel currents (TBKCs) in UBSM cells. Confocal and ratiometric fluorescence microscopy studies revealed that inhibition of constitutive PKA activity with H-89 reduced the frequency and amplitude of the localized Ca2+ sparks but increased global Ca2+ levels and the magnitude of Ca2+ oscillations in UBSM cells. H-89 abolished the spontaneous transient membrane hyperpolarizations and depolarized the membrane potential in UBSM cells. Inhibition of PKA with H-89 or KT-5720 also increased the amplitude and muscle force of UBSM spontaneous phasic contractions. This study reveals the novel concept that constitutive PKA activity is essential for controlling localized Ca2+ signals generated by intracellular Ca2+ stores and cytosolic Ca2+ levels. Furthermore, constitutive PKA activity is critical for mediating the spontaneous TBKCs in UBSM cells, where it plays a key role in regulating spontaneous phasic contractions in UBSM.
Convolution Operators on Spaces of Vector-Valued Functions that are Completely Continuous

Let X be a Banach space and let G be a compact abelian group. We study when convolution operators that are induced by a regular Borel scalar measure ν on G are Completely Continuous (or Dunford-Pettis) operators (respectively, Weak-Dunford-Pettis) when they act on C ( G,X ), the space of continuous X -valued functions defined on G , on the space L 1 ( G,X ), of strongly measurable X -valued function that are Bochner integrable functions defined on G , and other spaces of vector-valued functions. Keywords: Banach spaces; convolution operators; weakly compact operators; Dunford-Pettis property Quaestiones Mathematicae 32(2009), 569–585
Saissetia miranda (Homoptera: Coccidae), a Potential Pest of Citrus in Texas

Saissetia miranda (Cockerell & Parrott) was the only species of Saissetia collected in representative samples from South Texas. A small increase in numbers of S. miranda occurred during May but the largest increase took place during the August and October period. This scale insect was observed on oleander, fig, and guava for many years but was not observed on citrus in South Texas until September 1967. Other host plants are given. Saissetia oleae (Bernard) was considered to be the only black scale in the United States until 1969. For this reason, separation characters are provided to distinguish S. miranda, S. neglecta De Lotto, and S. oleac . Common names are proposed for each species. Mesopeltita atrocyanca (Masi) was the most common parasite reared from S. miranda although Coccophagus lycimnia (Walker) also became quite abundant during August and September 1970. Clarification of the relationship of 3 Saissetia species and their associated parasites will provide assistance in employing biological control measures in South Texas and in other areas where these scales are problems.
Quartz crystal microbalance measurements of mitochondrial depolarization predicting chemically induced toxicity of vascular cells and macrophages

Abstract Quartz crystal microbalances (QCMs) measure mass on the nanogram (ng) scale. We built novel QCMs as toxicity biosensors incorporating living cells. Human endothelial cells or canine macrophages were equilibrated on QCM crystal surfaces until stable oscillation frequencies occurred. Vehicle or sodium azide (NaN 3 ) (25–100 mM) was added to these QCMs while continuously collecting crystal oscillation frequency data. At these doses, NaN 3 alters mitochondrial membrane permeability and causes mitochondrial swelling and intrinsic apoptosis. Our studies demonstrated no frequency change in QCMs with untreated cells or without cells but NaN 3 . If NaN 3 was added to either cell type within QCMs, 5 to 8 min later increases in oscillation frequency (Δ f ) occurred (400–1600 Hz) that correlated with dose. All frequency changes reverted to baseline by 15 min. In parallel, during the first 30 min, no change in cell or nuclear areas, or in actin or microtubule distributions, was detected. Yet, mitochondrial size and membrane permeability increased significantly during, but not after, 5 to 8 min. Viability studies confirmed dose-dependent toxicity that was predicted and proportionate to the 5- to 8-min Δ f. These studies confirm that cell-based QCMs can detect early events in intrinsic apoptosis and reveal unique kinetic information about events occurring within subcellular structures in response to toxins.
A Stakeholder-Unifying, Cocreation Philosophy for Marketing

Marketing thought and practice is continuing its evolution from a largely goods-dominant logic to a service-dominant (S-D) logic. The authors argue that an S-D grounded logic is especially useful in a highly networked world. In a network world and organization, it is critical for enterprises to realize and operate as if marketing is no longer simply a separate business function but also a general management responsibility within a broad network enterprise where the interests of many stakeholders need to be unified with the customer and the enterprise. Furthermore, a value cocreation concept of strategy becomes increasingly relevant because it views value as not created by the business but by customers as they integrate resources. Importantly this includes firm-supplied resources, as well as other resources at the customer’s disposal in order to improve their well-being by helping them develop or codevelop solutions to problems. Consistent with the S-D logic of marketing, the firm has to think not about op...
A Revision of the Central American Genus Romanschulzia (Brassicaceae)

Abstract A revision of the 14 species of Romanschulzia is presented. Full synonymy, descriptions, ecological data, when available, and a key are given. Based on the examination of type collections of all species, the limits of Romanschulzia is expaned to include two species, R. alpina and R. mexicana, previously placed in the genera Lexarzanthe, Sisymbrium, and Thelypodiopsis. The present account deviates from the most recent account of the genus, especially for the most widespread species.
Indole derivatization procedures for electron capture negative chemical ionization mass spectrometry: Identification of 1‐methyl‐1,2,3,4‐tetrahydro‐β‐carboline in rat brain and lung

Procedures have been developed for the isolation of pharmacologically active indole compounds from biological samples and for the introduction of electron-capturing groups, pentafluorobenzyl and trifluoroacetyl, onto the indole nitrogen atom. The resulting derivatives have good gas chromatographic properties and strong electron affinities which make them highly suitable for detection by electron capture negative chemical ionization mass spectrometry. These procedures were used to identify 1-methyl-1,2,3,4-tetrahydro-beta-carboline as a component of rat brain and lung.
Can age-related deficits in spatial memory be attenuated through the use of verbal coding?

Abstract In a sequential mental rotation task, women of three age groups (18–28, 50–60, and 70–80) viewed semi-abstract figures which were rotated in the picture plane. To investigate the effects of verbal mediation, each figure was presented under one of four labeling conditions. Errors increased as a function of age. Meaningful labels were beneficial in decreasing errors for the older subjects. Reaction time results generally replicated earlier studies, but there were indications that some women in the oldest group might have used strategies other than mental rotation. Results suggest that possible age related deficiencies in spatial abilities may be compensated for by greater use of verbal mediation.
A Prospective Randomized Trial of 0.010″ Versus 0.014″ Balloon PTCA Systems and Interventional Fellow Versus Attending Physician as Primary Operator in Elective PTCA: Economic, Technical, and Clinical End Points

Background: The cost of performing percutaneous transluminal coronary angioplasly (PTCA) is accelerating. The angiographic, clinical, technical, and procedural variables associated with PTCA cost are largely unknown. Methods: To determine an interrelationship between equipment size, operator experience, and PTCA cost, 50 patients were randomized to have PTCA performed with large (0.014″) or small (0.010″) balloon systems. A secondary randomization determined the primary operator of the procedure: either experienced attending physician or inexperienced fellow in interventional cardiology. End Points: Primary: PTCA cost (equipment, supplies, support personal, post-PTCA room, and physician (utilizing resource-based relative value scale); Secondary: measures of technical procedural and clinical outcome. Results: The total cost of the PTCA was $4,047 ±$2,133 for 0.010″ systems versus $3,451 ±$1,004 for the 0.014″ systems, P = NS. Independent variables associated with increased cost included: age, diabetes, and duration of procedure in the cardiac catheterization laboratory. There was no significant difference in procedural duration, complications, or outcome between the smaller or larger PTCA catheter systems, and, the less experienced PTCA operator required additional fluoroscopic time to cross the lesion, as well as procedure time compared with the attending physician. Conclusions: Neither miniaturization of equipment size nor primary operator experience led to PTCA cost savings. Clinical and procedural characteristics are independently correlated with increased PTCA cost. Additional study is needed to determine the exact determinants of PTCA cost, in order to stabilize the cost of this procedure. (J Interven Cardiol 1995;8:623–632)
Why Do They Call Them “IQ Tests”?:

Psychological tests, in general, measure defined characteristics of people. It is unclear from the terminology, however, whether “IQ tests” measure a characteristic called intelligence or, going with the logic of the expression, measure a score (or index) called an intelligence quotient. We submit that instruments which are so labeled are misnamed and misused also when those who apply them do so basically to gain an IQ to the neglect of the important features of intellectual functioning that can be gained from a test of intelligence. The nonprofessional who has a personal or occupational interest in the assessment of intelligence should be made aware of the potential contributions of intelligence tests and the proper role of IQ.
US pharmaceutical innovation in an international context.

Objectives. We explored whether the United States, which does not regulate pharmaceutical prices, is responsible for the development of a disproportionate share of the new molecular entities (NMEs; a drug that does not contain an active moiety previously approved by the Food and Drug Administration) produced worldwide.Methods. We collected data on NMEs approved between 1992 and 2004 and assigned each NME to an inventor country. We examined the relation between the proportion of total NMEs developed in each country and the proportion of total prescription drug spending and gross domestic product (GDP) of each country represented.Results. The United States accounted for 42% of prescription drug spending and 40% of the total GDP among innovator countries and was responsible for the development of 43.7% of the NMEs. The United Kingdom, Switzerland, and a few other countries innovated proportionally more than their contribution to GDP or prescription drug spending, whereas Japan, South Korea, and a few other c...
The Tensions of Christian Living

well as in Saint Paul. The differences in emphasis, however, are instructive. Aristotle alone cherishes the classical conviction that somehow or other an ideal harmony can be wrought out of the clash of opposites, and that by rational discipline man may learn to avoid the extremes and to achieve the balanced life of the mean. On the other hand, Plato with his mind-body dualism and Paul with his flesh-spirit dualism incline to the ascetic principle, and teach that there is no salvation for man until the body or the flesh is utterly subjugated or even rejected for the life of pure mind or pure spirit. The distinctive contribution of dialectical theology is to urge that man's career on this earth points neither to harmony nor to ascetic denial, but finds its meaning and fulfilment in the very fact of the tension between the angel and the animal, the god and the beast. In any case, since the issue is so much before us these days, it seems worth while to attempt a simplified statement and summary of the essentials of the doctrine. We may enumerate the chief areas of tension and indicate the main alternatives of action; we may inquire further into certain very practical implications for Christian ethics and for the Christian understanding of man; and, finally, we may ask what all this tells us of the significance of the Savior for our lives. Such an inquiry as this may not yield much that is startling and new, but it may contribute to the discussion certain useful qualities of order, clarity, relevance, and intelligibility.
Host plant influence on the mating success of male Mediterranean fruit flies: variable effects within and between individual plants

Abstract Observations of field-caged guava trees, Psidium guajava, revealed that males of the Mediterranean fruit fly (medfly), Ceratitis capitata, occasionally formed tight aggregations on the trunk and branches of certain trees. Males at these aggregation sites (stations) appeared to feed on the bark, and chemical analyses showed that stations contained high levels of the male attractant α-copaene whereas ‘nonstations’ on the same tree lacked this chemical. Previous work showed that male medflies exposed to pure α-copaene had a mating advantage over unexposed males. Here, we present data showing that the occurrence of stations is highly variable both within and between individual guava trees. Concurrent mating trials showed that male medflies exposed to entire guava trees containing stations or to individual stations for 3 h gained a mating advantage over unexposed males in tests conducted 1 or 3 days following exposure. In contrast, males exposed to entire trees lacking stations or only to nonstations on trees with stations had similar mating success as unexposed males. Additional experiments showed that exposure to guava leaves had no effect on male mating frequency but that exposure to fruits enhanced male mating success. The discussion considers potential mechanisms underlying the plant-induced increase in mating success and potential effects of α-copaene and other plant-borne compounds on the spacing of medfly leks in the environment.
Meeting the virtual work imperative

How collaborative technologies can facilitate face-to-face meetings without the need to even be in the same room.
Low energy ion beam transport by permanent magnets

The guiding of a 300 eV divergent hydrogen ion beam by a surface magnetic field generated by samarium cobalt magnets has been investigated. It was found that magnets arranged in a multi‐ring‐cusp configuration produced the best beam transport efficiency.
Potent magnesium-dependent inhibition of adenylate cyclase activity from guinea pig lung by adenosine and other 9-substituted adenines

Abstract The inhibition of adenylate cyclase activity (ATP pyrophosphate-lyase (cyclizing), EC 4.6.1.1) from guinea pig lung by adenosine and a number of 9-substituted adenines was Mg2+-dependent, the compounds being up to 13 times more potent at saturating or near saturating Mg2+ concentrations (11.8 mM) than at limiting (1.8 mM) concentrations. Inhibition by adenine and 6-mercaptopurine did not show a Mg2+ dependence. The most potent inhibitors of cyclase activity at 11.8 mM Mg2+ of the 9-substituted adenines tested were: 9-(tetrahydro-5-methyl-2-furyl)adenine (I50 = 8 μM), 9-(tetrahydro-2-furyl)adenine (I50 = 10 μM), 9-cyclopentyladine I50 = 20 μM), and 9-furfuryadenine I50 = 26 μM). The inhibition of lung cyclase activity by 9-(tetrahydro-2-furyl)adenine was deduced to be hyperbolic non-competitive at 1.8 mM (K1 = 1.2·10−4 M) and 11.8 mM (K1 = 2.5·10−6 M) Mg+ from analysis of double-reciprocal plots; these plots showed a concave downward non-linearity in the presence of inhibitor at both Mg2+ concentrations. This non-linearity was eliminated under conditions where Mg2+ levels were never in excess of those of ATP. Hill plots of the inhibition by 9-(tetrahydro-2-furyl)adenine (and by adenosine) suggested that negative co-operativity is involved in binding to the enzyme. The possibility that the Mg2+-dependence of inhibitory potency of adenosine and its analogs functions as a cellular control mechanism is discussed.
Gamma and the Coordination of Spiking Activity in Early Visual Cortex

Gamma components of the local field potential (LFP) are elevated during cognitive and perceptual processes. It has been suggested that gamma power indicates the strength of neuronal population synchrony, which influences the relaying of signals between cortical areas. However, the relationship between coordinated spiking activity and gamma remains unclear, and the influence on corticocortical signaling largely untested. We investigated these issues by recording from neuronal populations in areas V1 and V2 of anesthetized macaque monkeys. We found that visual stimuli that induce a strong, coherent gamma rhythm result in enhanced pairwise and higher-order V1 synchrony. This is associated with stronger coupling of V1-V2 spiking activity, in a retinotopically specific manner. Coupling is more strongly related to the gamma modulation of V1 firing than to the downstream V2 rhythm. Our results thus show that elevated gamma power is associated with stronger coordination of spiking activity both within and between cortical areas.
Genetic quality of individuals impacts population dynamics

Ample evidence exists that an increase in the inbreeding level of a population reduces the value of fitness components such as fecundity and survival. It does not follow, however, that these decreases in the components of fitness impact population dynamics in a way that increases extinction risk, because virtually all species produce far more offspring than can actually survive. We analyzed the effects of the genetic quality (mean fitness) of individuals on the population growth rate of seven natural populations in each of two species of wolf spider in the genus Rabidosa, statistically controlling for environmental factors. We show that populations of different sizes, and different inbreeding levels, differ in population dynamics for both species. Differences in population growth rates are especially pronounced during stressful environmental conditions (low food availability) and the stressful environment affects smaller populations (<500 individuals) disproportionately. Thus, even in an invertebrate with an extremely high potential growth rate and strong density-dependent mortality rates, genetic factors contribute directly to population dynamics and, therefore, to extinction risk. This is only the second study to demonstrate an impact of the genetic quality of individual genotypes on population dynamics in a wild population and the first to document strong inbreeding–environment interactions for fitness among populations. Endangered species typically exist at sizes of a few hundred individuals and human activities degrade habitats making them innately more stressful (e.g. global climate change). Therefore, the interaction between genetic factors and environmental stress has important implications for efforts aimed at conserving the Earth's biodiversity.
RETROGRADE AMNESIC EFFECT OF AUDIOGENIC SEIZURE ON THE REVERSAL OF A MAZE RESPONSE.

Sunzmary.-Two groups of mice were given acquisition trials followed by reversal training in a water maze. Experimental Ss were convulsed with a single audiogenic seizure immediately following the last reversal trial. 50% of the latter Ss showed retention of the initial response, but retrograde amnesia for the reversed maze habit. Control Ss all showed retention of the reversed response. The data tend to support the conclusion that audiogenic seizure is partially effective in disrupting the consolidation of the memory trace. Earlier reports concerning che behavioral effect of audiogenic seizure in rodents have indicated that such an event, occurring in close temporal proximity with learning, results in a retention deficit for such learned behavior. Brady, et al., (1953) demonstrated such a deficit in rats given multiple audiogenic seizures after learning; more recently, Essman and Hamburgh (1962) showed that mice convulsed once with auditory stimulation following maze acquisition showed significant retention deficit. These studies support a consolidation theory of memory formation (Glickman, 1961), in that the magnintde of retention deficit is inversely related to the duration of the interval between learning and audiogenic seizure. The purpose of the present experiment was to examine the effect of a single audiogenic seizure on an acquired maze response and a reversal of the maze habit. METHOD Mice of a sub-line of the Swiss-Webster strain bred for susceptibility to audiogenic seizure were used (N = 20). All mice, weighing approximately 20 gm., were given four trials to acq~lire a simple sensori-motor escape response from a tank of water (Essman & Jarvik, 1961). Trials were spaced at 15-min. intervals. Following each trial S was toweled dry and retained under a 60-w light bulb. Response latency (interval berween placement in tank and successful escape by swimming to an escape ramp) and error (response to an area equal in size co the base of a triangle formed by the escape ramp on the side opposite that on which escape ramp was positioned) were measured for all Ss on all trials. One hour following maze acquisition Ss were randomly assigned to two groups. The experimental group (N = 10) was given four habit-reversal trials with the escape ramp positioned on the side opposite that for initial acquisition. Trials were spaced at 3-min. intervals and Ss were toweled dry and kept under a 60-w bulb after each trial. Response latency and errors were again recorded. In 'This study was supported, in part, by Grant MH-08698-01 from the National Instimtes of Health.
Towards understanding the DO-178C / ED-12C assurance case

This paper describes initial work towards building an explicit assurance case for DO-178C / ED-12C. Two specific questions are explored: (1) What are some of the assumptions upon which the guidance in the document relies, and (2) What claims are made concerning test coverage analysis?
Judgments of perceptual groups: reliability and sensitivity to stimulus transformation.

The reliability of subjects’ judgments of the groups present in dot patterns and the sensitivity of those judgments to stimulus transformation were assessed. The subjects indicated the groups that they saw within random dot patterns, and each judgment was compared with those of other subjects and with their own judgments for related presentations. Within subjects, each pattern appeared in an initial presentation, an identical repetition, and a transformed state (a rotation or a change in scale). Witfiin-subjects judgments were more reliable than between-subjects judgments. An interpretation of within-subjects results was made in relation to predictions made by a formal algorithm of grouping by proximity (the CODE algorithm), which assumes that grouping by proximity is invariant over transformations such as rotations or changes in scale. A slight cost to transforming the patterns was found. The implications for CODE and for using grouping judgments as data are discussed.
Uptake and Sequestration of Naphthalene and 1,2-Dichlorobenzene by C 60

The interactions of common environmental contaminants with C60 have been studied to evaluate the environmental impact of carbon nanomaterials. The adsorption and desorption interaction of the hydrophobic contaminants naphthalene and 1,2-dichlorobenzene with C60 was characterized. Processes that cause the wetting and disaggregating of C60 particles also affect the extent of organic contaminant sorption to C60 aggregates by orders of magnitude. C60 dissolved in organic solvents such as toluene can form stable nanoscale aggregates upon vigorous mixing in water. These nanoscale C60 particles form stable suspensions in water and are referred to as ‘nano-C60’. Desorption of contaminants from stable suspensions of nano-C60 exhibits hysteresis. The experimentally observed adsorption/desorption hysteresis is described by a two-compartment desorption model: first, adsorption to the external surfaces that are in contact with water, and second, adsorption to the internal surfaces within the aggregates.
How geometrical constraints contribute to the weakness of mature faults

INCREASING evidence that the San Andreas fault has low shear strength1 has fuelled considerable discussion regarding the role of fluid pressure in controlling fault strength. Byerlee2,3 and Rice4 have shown how fluid pressure gradients within a fault zone can produce a fault with low strength while avoiding hydraulic fracture of the surrounding rock due to excessive fluid pressure. It may not be widely realised, however, that the same analysis2–4 shows that even in the absence of fluids, the presence of a relatively soft 'gouge' layer surrounded by harder country rock can also reduce the effective shear strength of the fault. As shown most recently by Byerlee and Savage5, as the shear stress across a fault increases, the stress state within the fault zone evolves to a limiting condition in which the maximum shear stress within the fault zone is parallel to the fault, which then slips with a lower apparent coefficient of friction than the same material unconstrained by the fault. Here we confirm the importance of fault geometry in determining the apparent weakness of fault zones, by showing that the apparent friction on a sawcut granite surface can be predicted from the friction measured in intact rock, given only the geometrical constraints introduced by the fault surfaces. This link between the sliding friction of faults and the internal friction of intact rock suggests a new approach to understanding the microphysical processes that underlie friction in brittle materials.
Differences in courtship aggression among six clones of unisexual fish

Abstract Hybridization between the viviparous fishes Poeciliopsis monacha and P. lucida of northwestern Mexico has resulted in the formation of diploid and triploid all-female ‘species’, P. monacha-lucida and P. monacha -2 lucida . These females reproduce by mating back to P. lucida , and are essentially clonally reproducing sexual parasites superimposed on that species. In a series of behavioural experiments, one diploid clone proved to be significantly more aggressive than one triploid and four other diploid clones. No differences in aggression were exhibited among the other five clones. The aggressiveness of this one clone may explain why only two clones live in the small tributary where it is found but up to 10 diploid and triploid clones occur where it is absent.
Some Methodological Concerns When Estimating the Size of Organizing Activities

Abstract Researchers and organizers recognize that social movements experience periods of inception, expansion, and decline. Although the movement literature is laden with numerous theoretical formulations on this topic, there are few articles that overtly address the issue of data collection. This paper addresses this methodological issue in detail. In doing so, we use previous media research and two case studies to illustrate the problems associated with the most frequently used data sources of event size. Finally, the paper suggests several research strategies that might enhance the accuracy of those studies that try to trace the protest cycles of community organizing efforts.
Using assembly representations to enable evolutionary design of Lego structures

This paper presents an approach to the automatic generation of electromechanical engineering designs. We apply messy genetic algorithm (GA) optimization techniques to the evolution of assemblies composed of LegoTM structures. Each design is represented as a labeled assembly graph and is evaluated based on a set of behavior and structural equations. The initial populations are generated at random, and design candidates for subsequent generations are produced by user-specified selection techniques. Crossovers are applied by using cut and splice operators at the random points of the chromosomes; random mutations are applied to modify the graph with a certain low probability. This cycle continues until a suitable design is found. The research contributions in this work include the development of a new GA encoding scheme for mechanical assemblies (Legos), as well as the creation of selection criteria for this domain. Our eventual goal is to introduce a simulation of electromechanical devices into our evaluation functions. We believe that this research creates a foundation for future work and it will apply GA techniques to the evolution of more complex and realistic electromechanical structures.
Synthesizing data structure transformations from input-output examples

We present a method for example-guided synthesis of functional programs over recursive data structures. Given a set of input-output examples, our method synthesizes a program in a functional language with higher-order combinators like map and fold. The synthesized program is guaranteed to be the simplest program in the language to fit the examples. Our approach combines three technical ideas: inductive generalization, deduction, and enumerative search. First, we generalize the input-output examples into hypotheses about the structure of the target program. For each hypothesis, we use deduction to infer new input/output examples for the missing subexpressions. This leads to a new subproblem where the goal is to synthesize expressions within each hypothesis. Since not every hypothesis can be realized into a program that fits the examples, we use a combination of best-first enumeration and deduction to search for a hypothesis that meets our needs. We have implemented our method in a tool called λ2, and we evaluate this tool on a large set of synthesis problems involving lists, trees, and nested data structures. The experiments demonstrate the scalability and broad scope of λ2. A highlight is the synthesis of a program believed to be the world's earliest functional pearl.