bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flicker Fusion Phenomena
Authors: Levinson John Z. 
Published: October 2006

The high-frequency temporal behavior of the human visual system has been shown to have some of the properties of a linear low-pass filter. For such a system it is appropriate to consider a repetitive stimulus as having separable Fourier harmonic components. The direct-current component or average luminance is important in that it sets the adaptation level. It is therefore convenient to keep it constant when varying other stimulus parameters, such as frequency or wave form. Of the alternating-current components, only the fundamental is important at high frequencies, the higher harmonics being relatively more attenuated.
Any linear low-pass filter system responds in a predictable way to sinusoidal stimulation, whether continuous or of short duration. In the case of the visual system, predictable behavior is found at high frequencies, and it leads to discovery of hitherto unobserved pseudoflash and real flash phenomena. Measurement of a new characteristic time is suggested.
At low frequencies the use of half- and whole-sinusoidal flashes leads to the discovery of some interesting relations with flicker thresholds, but these remain for future discussion.
The Sulfur Cycle
Authors: Kellogg W. W. , Cadle R. D. , Allen E. R. , Lazrus A. L. , Martell E. A. 
Published: October 2006

Even granting our uncertainties about parts of our model of the sulfur cycle, we can draw some conclusions from it:
1) Man is now contributing about one half as much as nature to the total atmospheric burden of sulfur compounds, but by A.D. 2000 he will be contributing about as much, and in the Northern Hemisphere alone he will be more than matching nature.
2) In industrialized regions he is overwhelming natural processes, and the removal processes are slow enough (several days, at least) so that the increased concentration is marked for hundreds to thousands of kilometers downwind.

3) Our main areas of uncertainty, and ones that demand immediate attention because of their importance to the regional air pollution question, are: (i) the rates of conversion of H
2
S and SO
2
to sulfate particles in polluted as well as unpolluted atmospheres; (ii) the efficiency of removal of sulfur compounds by precipitation in polluted air. And for a better understanding of the global model we need to know: (i) the amount of biogenic H
2
S that enters the atmosphere over the continents and coastal areas; (ii) means of distinguishing man-made and biogenic contributions to excess sulfate in air and precipitation; (iii) the volcanic production of sulfur compounds, and their influence on the particle concentration in the stratosphere; (iv) the large-scale atmospheric circulation patterns that exchange air between stratosphere and troposphere (although absolute amounts of sulfate particles involved are small relative to the lower tropospheric burden); (v) the role of the oceans as sources or sinks for SO
2
.
Esophageal Cancer in the Caspian Littoral of Iran: Initial Studies
Authors: Kmet Janez , Mahboubi Ezattollah 
Published: October 2006

A peculiar distribution of esophageal cancer was observed in the Caspian littoral of Iran, where an ad hoc cancer registry has been in operation since 1968. A very high incidence, among the highest recorded in the world, with a higher incidence in women than in men (male: 108.8 cases per 100,000 population; female: 174.1 per 100,000), was recorded in the northeastern corner of the region; this sparsely populated, semidesert area of the central Asian type, with predominantly saline soils, was settled by Turkomans. A lower incidence with a change in the male-to-female ratio was observed in the southeastern and central parts of the region, which are located in the piedmont area of the Elburz Mountains; these areas have more abundant rainfall and nonsaline soils, and are densely populated by Iranians. A steady decline in the incidence with an increase in the preponderance of male cases was observed toward the west, reaching the lowest figures (male: 17.2 cases per 100,000 population; female: 5.5 per 100,000) in the Caspian rain belt, with its heavily leached soils and somewhat subtropical characteristics. Changes in the natural vegetation and in the agricultural practices parallel the changing features of the climate.
A multidisciplinary, multidisease, and multifactorial study is in preparation. By plotting the detailed physical, biotic, and cultural characteristics of the selected ecological regions on the intrinsic characteristics of the population groups experiencing different esophageal cancer risk, new and profitable working hypotheses as to the etiology of esophageal cancer might be produced.
Light Pollution
Authors: Riegel Kurt W. 
Published: October 2006

There have been major qualitative and quantitative changes in outdoor lighting technology in the last decade. The level of skylight caused by outdoor lighting systems is growing at a very high rate, about 20 percent per year nationwide. In addition, the spectral distribution of man-made light pollution may change in the next decade from one containing a few mercury lines to one containing dozens of lines and a significantly increased continuum level. Light pollution is presently damaging to some astronomical programs, and it is likely to become a major factor limiting progress in the next decade. Suitable sites in the United States for new dark sky observing facilities are very difficult to find.
Some of the increase in outdoor illumination is due to the character of national growth and development. Some is due to promotional campaigns, in which questionable arguments involving public safety are presented. There are protective measures which might be adopted by the government; these would significantly aid observational astronomy, without compromising the legitimate outdoor lighting needs of society. Observatories should establish programs to routinely monitor sky brightness as a function of position, wavelength, and time. The astronomical community should establish a mechanism by which such programs can be supported and coordinated.
Chemical Messengers in Development: A Hypothesis
Authors: McMahon Daniel 
Published: October 2006

The hypothesis that physiological and developmental regulatory mechanisms are similar has been presented. Well-known developmental systems chosen illustrate the capability of the model to suggest a simple mechanism underlying the effects on development of a diverse group of chemicals. This hypothesis might be applied to other systems including the induction of the lens, limb regeneration, and the induction of the head of hydra.
I have proposed this hypothesis not only because it permits consideration of a complex and varied array of experimental observations as reflections of a simple basic biochemical mechanism, but because recent technical advances in instrumentation and methods allow it to be directly tested. The fluorescent antibody method for the cytochemical measurement of cyclic nucleotides provides a means for investigating changes in the concentrations of cyclic nucleotides in developing cells and could also be used to detect neurotransmitters in developing cells. Similarly, the scanning electron microscope in the emitted x-ray mode provides a method for measuring changes in the content and distribution of cations within developing cells.
The hypothesis presented here suggests pleasing asceticism on the part of eukaryotes. It suggests that simple derivatives of metabolites, including neurotransmitters and cyclic nucleotides, are linked together as regulatory molecules throughout the eukaryotes. The neurotransmitters are suggested to have a more general role in information transmission in eukaryotes than is generally accepted. They are hypothesized to have progressed during evolution from being intracellular messengers to a role as intercellular messengers for the relatively slow communication of developmental information; and, finally, this process has culminated with their participation in the rapid intercellular communication mediated by nerves. The thought that the complex pictures of physiological regulation and of the construction of a complex multicellular organism like man might be painted with so few colors is quite satisfying.
Infection of human cytomegalovirus in cultured human gingival tissue
Authors: Hai Rong , Chu Alice , Li Hongjian , Umamoto Sean , Rider Paul , Liu Fenyong 
Published: October 2006

Abstract

Background
Human cytomegalovirus (HCMV) infection in the oral cavity plays an important role in its horizontal transmission and in causing viral-associated oral diseases such as gingivitis. However, little is currently known about HCMV pathogenesis in oral mucosa, partially because HCMV infection is primarily limited to human cells and few cultured tissue or animal models are available for studying HCMV infection.

Results
In this report, we studied the infection of HCMV in a cultured gingival tissue model (EpiGingival, MatTek Co.) and investigated whether the cultured tissue can be used to study HCMV infection in the oral mucosa. HCMV replicated in tissues that were infected through the apical surface, achieving a titer of at least 300-fold at 10 days postinfection. Moreover, the virus spread from the apical surface to the basal region and reduced the thickness of the stratum coreum at the apical region. Viral proteins IE1, UL44, and UL99 were expressed in infected tissues, a characteristic of HCMV lytic replication in vivo. Studies of a collection of eight viral mutants provide the first direct evidence that a mutant with a deletion of open reading frame US18 is deficient in growth in the tissues, suggesting that HCMV encodes specific determinants for its infection in oral mucosa. Treatment by ganciclovir abolished viral growth in the infected tissues.

Conclusion
These results suggest that the cultured gingival mucosa can be used as a tissue model for studying HCMV infection and for screening antivirals to block viral replication and transmission in the oral cavity.
The variable colours of the fiddler crabUca vomerisand their relation to background and predation
Authors: Hemmi Jan M. , Marshall Justin , Pix Waltraud , Vorobyev Misha , Zeil Jochen 
Published: October 2006

SUMMARYColour changes in fiddler crabs have long been noted, but a functional interpretation is still lacking. Here we report that neighbouring populations of Uca vomeris in Australia exhibit different degrees of carapace colours, which range from dull mottled to brilliant blue and white. We determined the spectral characteristics of the mud substratum and of the carapace colours of U. vomeris and found that the mottled colours of crabs are cryptic against this background, while display colours provide strong colour contrast for both birds and crabs, but luminance contrast only for a crab visual system. We tested whether crab populations may become cryptic under the influence of bird predation by counting birds overflying or feeding on differently coloured colonies. Colonies with cryptically coloured crabs indeed experience a much higher level of bird presence, compared to colourful colonies. We show in addition that colourful crab individuals subjected to dummy bird predation do change their body colouration over a matter of days. The crabs thus appear to modify their social signalling system depending on their assessment of predation risk.
Locomotor kinetics and kinematics on inclines and declines in the gray short-tailed opossumMonodelphis domestica
Authors: Lammers Andrew R. , Earls Kathleen D. , Biknevicius Audrone R. 
Published: October 2006

SUMMARYSmall terrestrial animals continually encounter sloped substrates when moving about their habitat; therefore, it is important to understand the mechanics and kinematics of locomotion on non-horizontal substrates as well as on level terrain. To this end, we trained gray short-tailed opossums(Monodelphis domestica) to move along level, 30° inclined, and 30° declined trackways instrumented with a force platform. Vertical,craniocaudal and mediolateral impulses, peak vertical forces, and required coefficient of friction (μreq) of individual limbs were calculated. Two high speed video cameras were used to simultaneously capture whole limb craniocaudal and mediolateral angles at limb touchdown, midstance and lift-off. Patterns on the level terrain were typical for non-primate quadrupeds: the forelimbs supported the majority of the body weight, forelimbs were net braking and hindlimbs net propulsive, and both limb pairs exerted small laterally directed impulses. M. domestica moved more slowly on sloped substrates in comparison to level locomotion, and exhibited a greaterμ req. On inclines, both limb pairs were more protracted at touchdown and more retracted at lift-off, fore- and hindlimbs had equal roles in body weight support, forelimbs exerted greater propulsive impulse than hindlimbs, and μreq was greater in the forelimbs than in hindlimbs. On declines, only the forelimbs were more protracted at touchdown;forelimbs supported the great majority of body weight while they generated nearly all of the braking impulse and, despite the disparity in fore-vs hindlimb function on the decline, μreq was not significantly different between limbs. These differences on the inclined and declined surfaces most likely result from (1) the location of the opossums'center of mass, which is closer to the forelimbs than to the hindlimbs, and(2) the greater functional range of the forelimbs versus the hindlimbs.
Novel Inorganic–Organic Layered Composite Synthesized by Polycondensation of 3-Aminopropyltriethoxysilane Associated with the Self-assembly of Alkanoate
Authors: Chujo Takayuki , Gonda Yu , Oumi Yasunori , Sano Tsuneji , Yoshitake Hideaki 
Published: October 2006

Abstract
We synthesized a layered organosilica with a self-assembled alkanoate interlayer. The bond between the alkanoate and aminopropylsiloxane is critical for the formation of such a structure. The surfactant can be exchanged with alkanoate with a different chain length to form other lamellar structures with a corresponding basal spacing.
Molecular Modification of 2,6-Diphenylbenzo[1,2-b:4,5-b′]dichalcogenophenes by Introduction of Strong Electron-withdrawing Groups: Conversion from p- to n-Channel OFET Materials
Authors: Takimiya Kazuo , Kunugi Yoshihito , Ebata Hideaki , Otsubo Tetsuo 
Published: October 2006

Abstract
2,6-Diphenylbenzo[1,2-b:4,5-b′]dithiophene (DPh-BDT) and -diselenophene (DPh-BDS) as p-channel semiconducting materials were modified by introducing fluoro, cyano, or trifluoromethyl groups into the attached phenyl moieties. On examination of organic field-effect transistors fabricated using these modified compounds, the trifluoromethyl-substituted DPh-BDT and BDS derivatives were found to act as n-channel semiconductors with high electron mobilities of 0.044 and 0.10 cm2 V−1 s−1, respectively.
Molecular Oxygen To Regenerate PdII Active Species
Authors: Muzart Jacques 
Published: October 2006

AbstractPalladium(II) catalysis allows various aerobic oxidation reactions, but the mechanism of the regeneration of the active catalytic species remains, in many cases, undetermined. In recent years, considerable effort has been directed toward the comprehension of the reaction of dioxygen with hydridopalladium(II) and palladium(0) complexes. This Focus Review highlights the results of these experimental and theoretical studies that can contribute to the exploitation of the powerful nature of PdII catalysis.
The Presence of a Ferrocenyl Unit on an Estrogenic Molecule is Not Always Sufficient to Generate in vitro Cytotoxicity
Authors: Vessières Anne , Spera Daniela , Top Siden , Misterkiewicz Boguslav , Heldt Jan‐Martin , Hillard Elizabeth , Huché Michel , Plamont Marie‐Aude , Napolitano Elio , Fiaschi Rita , Jaouen Gérard 
Published: October 2006

AbstractWe recently reported the dual (antihormonal and cytotoxic) functionality of ferrocifens, which are organometallic complexes derived from hydroxytamoxifen, the standard molecule in the treatment of hormone‐dependent breast cancers. To test the hypothesis that the presence of a ferrocenyl substituent on molecules with an affinity for the estrogen receptor is sufficient to give them cytotoxic properties in vitro, we prepared complexes derived from estradiol with a ferrocenyl substituent at positions 7α and 17α. The complexes thus obtained retain a satisfactory level of affinity for the estrogen receptor (RBA values higher than 12 %). At low concentrations (0.1–1 μM) the complexes show an estrogenic effect in vitro equivalent to that of estradiol on hormone‐dependent (MCF‐7) breast cancer cells, and no cytotoxic effect on hormone‐independent (MDA‐MB‐231) breast cancer cells. At high concentrations (up to 50 μM) the 17α‐ethynylferrocenyl estradiol and 7α‐ferrocenylmethylthio estradiol become cytotoxic (IC50=13.2 μM and 18.8 μm, respectively) while the 17α‐ferrocenylestradiol remains non toxic. The low toxicity of these compounds support our hypothesis that electronic communication between the ferrocenyl and phenol moieties in the hydroxyferrocifens series is a key parameter in the generation of cytotoxic effects at submicromolar concentrations.
Effect of the Electrolyte Concentration on Cation Binding in Aqueous Surfactant Solutions
Authors: Jakubowska Anna 
Published: October 2006

AbstractElectrospray ionisation mass spectrometry (ESI‐MS) is used for the qualitative and quantitative study of ion binding to interfaces. The ESI‐MS measurements are carried out in aqueous solutions of sodium dodecyl sulphate (SDS) in the presence of NaCl, NH4ClO4 , KCl, or Mg(ClO4)2 . The effect of the electrolyte concentration on the fractions, y, of the DS− monomers bound to the cations is shown. Moreover, the binding stability of different cations with DS− monomers is determined versus the electrolyte concentration. This stability and the y values (the Na+ ions derived from SDS), estimated in the presence of a given electrolyte, are quantitatively correlated with the electrolyte cation effect on the water structure. We also present calibration curves from which the molar concentrations of the sodium ions (derived from SDS) and of the other cations (derived from the electrolyte), bound to the SDS‐micelle surface at a given electrolyte concentration, can be obtained. Besides, specific ion effects (Hofmeister effects) are considered for 1:1 electrolytes.
Performance analysis of a file delivery system based on the FLUTE protocol
Authors: Peltotalo Jani , Peltotalo Sami , Harju Jarmo , Walsh Rod 
Published: October 2006

AbstractThis paper presents the results of performance tests carried out for a file delivery system based on the file delivery over unidirectional transport (FLUTE) protocol. FLUTE is a file transport protocol used to deliver files over IP networks, including the Internet and unidirectional systems, from a sender to one or more receivers. FLUTE uses UDP, an unreliable transport protocol, and so reliable delivery must be guaranteed by other means. This paper shows how FLUTE manages to recover from packet losses using forward path redundancy (forward error correction (FEC) and repeat transmissions in a data carousel), and a simple HTTP‐based point‐to‐point file repair scheme which is specified in 3GPP and DVB standards. The results presented in this paper show that careful optimization of FEC overhead, and the number of repeat transmissions, gives the best system performance in most cases. Based on the simplified error reception and distribution model depicted in this study, it is illustrated that the simple client‐server point‐to‐point file repair is optimal only for small groups. Several options to improve the configuration of FLUTE senders are provided, to deliver reception guarantees with optimal data expense from the system point of view. Copyright © 2006 John Wiley & Sons, Ltd.
Determination of Nonsteroidal Anti‐inflammatory Drugs in Serum by Microchip Capillary Electrophoresis with Electrochemical Detection
Authors: Ding Yongsheng , Garcia Carlos D. 
Published: October 2006

AbstractA simple and rapid method has been developed for the analysis of four nonsteroidal anti‐inflammatory drugs (NSAIDs) in serum using microchip capillary electrophoresis with pulsed amperometric detection. The selected NSAIDs (salicylic acid, acetaminophen, diflunisal, and diclofenac) are among the most commonly used drugs to treat fever, inflammation, and pain. Used above the therapeutic levels, these drugs can cause a wide variety of adverse effects and their fast analysis could have a significant impact in treatment and recovery of the patients. Several conditions, including separation potential, pH, and concentration of the electrolyte solution were studied to optimize the separation and detection. In this study, salicylic acid, acetaminophen, diflunisal, and diclofenac were separated in less than 2 minutes using a 5 mM borate buffer at pH 11.5 and a separation potential of +1200 V. Linear relationships were obtained between the concentration and peak current in the 0.5–15.3 μg/mL range and detection limits around 0.26 μg/mL. After 30 consecutive injections, the stability of both the response and migration time of the analytes showed relative related deviations of less than 4.6% and 1.0%, respectively. The potential of this method was verified by spiking a bovine serum sample with the four NSAIDs and analyzing the recovery ratio.
High interleukin‐6 plasma levels are associated with functional impairment in older patients with Vascular dementia
Authors: Zuliani G. , Guerra G. , Ranzini M. , Rossi L. , Munari M. R. , Zurlo A. , Blè A. , Volpato S. , Atti A. R. , Fellin R. 
Published: October 2006

AbstractIn older individuals, inflammatory mechanisms have been linked to the pathogenesis of both dementia and functional impairment. In this cross‐sectional study we have investigated the possible association between some markers of systemic inflammation and functional status, in a sample of one hundred and forty older demented patients including 60 patients with late onset Alzheimer's disease (LOAD) and 80 with vascular dementia (VD). Functional status was evaluated by Barthel Index (BI); the total score ranged from 0 (total dependency) to 20 (total autonomy). Interleukin‐1β, Tumor Necrosis Factor‐α, Interleukin‐ 6, Interleukin‐ 8, and Transforming Grow Factor β were quantified by ELISA. Among the cytokines evaluated, only IL‐6 was correlated with the BI (r: −0.32, p < 0.001). The mean levels of IL‐6 progressively decreased from I (9.50 pg/mL), to II (6.40 pg/mL), to III BI tertile (4.80 pg/mL) (p < 0.02).At multiple regression analysis, IL‐6 was associated with BI in the whole sample and in VD, but not in LOAD, independent of age, gender, smoking, alcohol consumption, hypertension, diabetes, coronary heart disease, previous stroke, and mini mental state examination score.Our study suggests the existence of an independent and negative relationship between IL‐6 plasma levels and functional status in older individuals with vascular dementia. This finding might contribute to explain the ‘excess of disability’ phenomenon described in older demented patients. Copyright © 2006 John Wiley & Sons, Ltd.