cssi/SciSciGPT-SciSciNet huggingface dataset:
The Dirichlet problem for singularly perturbed quasilinear elliptic equations

Assuming a C* solution, Holland [9] used probabilistic methods to verify the regular and boundary layer expansions for (1.2) in case the fj arc independent of u and z E R'. van Harten [ 141 proved the correctness of formal approximations for solutions of (1.2) with h = 0, i # n, in case the boundary values are given on an n-sphere. Howes [ 11, 12 ] has obtained existence and asymptotic estimates for solutions of various boundary value problems associated with (1.2) in case the equation h(z, U) = 0 has a smooth solution a0 which satisfies certain stability conditions and such that the characteristic curves for the equation
A Single-Point Calibration Technique for a Six Degree-of-Freedom Articulated Arm

A technique for calibrating an articulated device used in surgery is presented. The process requires only one point in the work envelope of the device to be known. The calibration procedure discussed, a trinary search technique, improves the performance of the articulated device three- to five-fold.
Bounded functions of vanishing mean oscillation on compact metric spaces

Abstract A well-known theorem of Wolff (Duke Math. J 49 (1982) 321) asserts that for every f ∈ L ∞ on the unit circle T , there is a non-trivial q ∈QA=VMO∩ H ∞ such that fq ∈QC. In this paper we consider the situation where T is replaced by a compact metric space ( X , d ) equipped with a measure μ satisfying the condition μ ( B ( x ,2 r ))⩽ Cμ ( B ( x , r )). We generalize Wolff's theorem to the extent that every function in L ∞ ( X , μ ) can be multiplied into VMO( X , d , μ ) in a non-trivial way by a function in VMO( X , d , μ )∩ L ∞ ( X , μ ). Wolff's proof relies on the fact that T has a dyadic decomposition. But since this is not available for ( X , d ) in general, our approach is completely different. Furthermore, we show that the analyticity requirement for the function q in Wolff's theorem must be dropped if T is replaced by S 2 n −1 with n ⩾2. Move precisely, if n ⩾2, then there is a g ∈ L ∞ ( S 2 n −1 , σ ), where σ is the standard spherical measure on S 2 n −1 , such that if q ∈ H ∞ ( S 2 n −1 ) and if q is not the constant function 0, then gq does not have vanishing mean oscillation on S 2 n −1 . The particular g that we construct also serves to show that a famous factorization theorem of Axler (Ann. of Math. 106 (1977) 567) for L ∞ -functions on the unit circle T cannot be generalized to S 2 n −1 when n ⩾2. We conclude the paper with an index theorem for Toeplitz operators on S 2 n −1 .
Study of the extinction coefficients of single-walled carbon nanotubes and related carbon materials

The measurement of the bulk purity of single-walled carbon nanotubes (SWNTs) is an important outstanding problem. We report a solution-phase near-IR (NIR) spectroscopic study of a range of carbon materials with an emphasis on SWNTs, and we show that NIR spectroscopy is an extremely powerful tool in the assessment of the carbonaceous purity of SWNTs. We demonstrate the applicability of Beer's law for all of the carbon materials included in this study within a range of concentrations in dimethylformamide (DMF), and we are able to solve for the effective extinction coefficients. By analyzing the areal absorptivities of the second interband transition of semiconducting SWNTs for a number of samples of differing purities, we are able to derive an absolute molar extinction coefficient for the carbonaceous impurities in SWNT samples. We demonstrate significant progress toward the establishment of an absolute scale for the bulk carbonaceous purity of SWNTs.
Minicolpostats, dome cylinders, other additions and improvements of the fletcher-suit afterloadable system: Indications and limitations of their use

Abstract The Fletcher prelosidable colpostat and intrauterine system was described in 1952. In the early 1960's it was made afterloadable by Suit et al; in 1968 we added cylindrical colpostats with specific indications for their use. Since the description of the first afterloadable system, several modifications have been made without departing from the fundamental features of the original preloadable model. The importance of these features was discussed at length in a recent publication. In this paper we describe improvements in design and introduce the minicolpostats and the dome colpostats. In addition, we discuss indications and limitations of their use.
Protective effects of freeze dried swordfish on methylmercury chloride toxicity in rats

This study quantifies selenium in swordfish and examines its prophylactic effect on methylmercury poisoning in rats. It was found that swordfish have twice as much selenium as mercury, and that a diet which included freeze-dried swordfish protected rats from the toxic effects of methylmercury.
Chondroblastic osteosarcoma of the cuboid: a literature review and report of a rare case.

Chondroblastic osteosarcoma accounts for about 25% of all cases of osteosarcoma, which is the most common primary malignancy of the skeleton. Currently, only a few cases of chondroblastic osteosarcoma have been reported to involve the bones of the foot. In this report, we describe the previously unreported occurrence of chondroblastic osteosarcoma involving the left tarsal cuboid in a 15-year-old male. Histologically, the tumor showed an unusually extensive osteoclastic giant cell reaction that initially led to an erroneous diagnosis of giant cell tumor of bone. Because treatment and prognosis are very different for chondroblastic osteosarcoma as compared to giant cell tumor of bone, it is important to make the distinction between these 2 different bone tumors. In this report, we wish to draw attention to occurrence of chondroblastic osteosarcoma in the small bones of the foot, and to the possibility of an extensive giant cell reaction making accurate diagnosis difficult. We also provide a comprehensive review of the literature related to chondroblastic osteosarcoma. Level of Clinical Evidence: 4
Meiofaunal effects on growth and survivorship of the polychaete Streblospio benedicti Webster and the bivalve Mercenaria mercenaria (L.)

Abstract The “meiofaunal bottleneck” theory states that permanent meiofauna negatively affect macrofaunal recruitment by either interfering with larval settlement or reducing survivorship and growth of recently-settled macrofaunal juveniles. Laboratory experiments examined the effects of a manipulated meiofaunal community of nematodes, copepods, and foraminiferans on the survivorship and growth of the polychaete Streblospio benedicti Webster and the bivalve Mercenaria mercenaria (L.). Results indicate that growth and survivorship of juveniles of both macrofaunal species were not significantly reduced by the presence of meiofauna. Within the context of our experiments, the meiofaunal numerical dominants in estuarine muddy sediments (nematodes and copepods) do not account for the “meiofaunal bottleneck”.
Regulated insulin delivery from human epidermal cells reverses hyperglycemia.

Alternative insulin therapies are being sought that will provide euglycemic control for people with diabetes mellitus. The epidermis is a self-renewing tissue that is easily accessible and can provide large numbers of autologous cells that can be used for generating insulin-secreting skin substitutes. Lentiviral vectors have been engineered to produce a fusion protein between the furin-cleavable proinsulin and the self-dimerization mutant of FK506-binding protein to yield bioactive insulin in keratinocytes; this insulin is released as a response to exogenous administration of a small organic molecule, rapamycin. The engineered keratinocytes retained normal morphology and grew in a manner similar to lentiviral-treated control cells. Epidermal keratinocytes in culture and in stratified bioengineered epidermis released insulin within 30 minutes after addition of rapamycin, and secretion slowed or stopped within 2–3 hours after removal of the inducing agent. When the cells were implanted into athymic mice that had been rendered diabetic with streptozotocin (STZ), insulin was detected in the plasma within 1 hour after addition of rapamycin. Concomitantly, serum glucose decreased to normal levels even in diabetic animals with severe hyperglycemia. Repeated rapamycin administration yielded similar results. These experiments provide proof-of-concept that insulin released from the skin in a regulatable manner can reverse hyperglycemia.
Rational Theories of Participation An Exercise in Definitions

In assessing the usefulness of economic models for political analysis, it is necessary to begin by defining the elements in the models. The present study looks at various ways to define “utility” or the goals of political activity, and how to operationalize the difference between private and public goals. Only when these are made precise can economic models be useful in predicting when and why people will act on their interests in politics. Some research is presented to explore the merits of different definitions of utility. The conclusion drawn is that economic models are most useful when they work with limited and clearly specified definitions of goals for political activity. In this way they can perform a predictive and diagnostic function. At the same time, it is likely that substantive changes in our collective life will have to emerge from other models of human behavior.
Steady Adiabatic, Two-Phase Flow of Steam and Water Through Porous Media

Reliable steam/water relative permeability curves that have not been previously reported were obtained under conditions of near-adiabatic, two-phase, steady flow in a unconsolidated Ottawa sandpack. Comparison of higher-temperature steam/water relative permeability curves to those for nitrogen/water at room temperature indicate that the two types of flows are essentially identical.
Spinodal decomposition in mixtures containing nematogens. II. Kinetics of spinodal decomposition

The problem of simultaneous phase separation and ordering kinetics in mixtures containing a nematic component is addressed through the introduction of a time‐dependent Landau–Ginzburg model. Dynamic equations for the time evolution of orientation and concentration fluctuations are given; the solution to these equations leads to explicit expressions for the structure factors for concentration and orientation. It is shown that the theory shares some salient features with the Cahn theory of spinodal decomposition. A simulation of a quenching experiment is performed and the time evolution of the structure factors during spinodal decomposition is calculated. Relevant small angle light scattering experiments which could be used to test the model are discussed.
Optimal Sensor Placement for Damage Detection in Complex Structures

An optimal sensor placement methodology is proposed based on detection theory framework to maximize the detection rate and minimize the false alarm rate. Minimizing the false alarm rate for a given detection rate plays an important role in improving the efficiency of a Structural Health Monitoring (SHM) system as it reduces the number of false alarms. The placement technique is such that the sensor features are as directly correlated and as sensitive to damage as possible. The technique accounts for a number of factors, like actuation frequency and strength, minimum damage size, damage detection scheme, material damping, signal to noise ratio (SNR) and sensing radius. These factors are not independent and affect each other. Optimal sensor placement is done in two steps. First, a sensing radius, which can capture any detectable change caused by a perturbation and above a certain threshold, is calculated. This threshold value is based on Neyman-Pearson detector that maximizes the detection rate for a fixed false alarm rate. To avoid sensor redundancy, a criterion to minimize sensing region overlaps of neighboring sensors is defined. Based on the sensing region and the minimum overlap concept, number of sensors needed on a structural component is calculated. In the second step, a damage distribution pattern, known as probability of failure distribute, is calculated for a structural component using finite element analysis. This failure distribution helps in selecting the most sensitive sensors, thereby removing those making remote contributions to the overall detection scheme.Copyright © 2009 by ASME
Electrochemical behavior of 3-chloro-2,4-pentanedione in the presence of cobalt salen

Abstract We have studied the catalytic two-electron reduction of 3-chloro-2,4-pentanedione by cobalt(I) salen electrogenerated at a glassy carbon cathode in acetonitrile containing tetramethylammonium tetrafluoroborate. When cobalt(I) salen is electrogenerated at −0.65 V (a potential that is 30 mV more negative than the peak potential for the reversible one-electron reduction of cobalt(II) salen), the carbon-chlorine bond of 3-chloro-2,4-pentanedione is catalytically cleaved to form 2,4-pentanedion-3-ate; this anion can be protonated either by adventitious water or by a deliberately added proton donor to produce 2,4-pentanedione, or the anion can be trapped with iodoethane to give 3-ethyl-2,4-pentanedione. However, when cobalt(I) salen is electrogenerated at −0.40 V (a potential at which the rate of generation of cobalt(I) salen is relatively small), the 2,4-pentanedion-3-ate, resulting from the catalytic two-electron cleavage described above, can deprotonate unreduced starting material to form 3-chloro-2,4-pentanedion-3-ate and 2,4-pentanedione. In further work, we have found that 2,4-pentanedion-3-ate can be oxidized directly to form the corresponding radical which couples to yield 3,4-diacetyl-2,5-hexanedione. Chemically produced 2,4-pentanedion-3-ate reacts with electrogenerated cobalt(III) salen to give a dionylcobalt(III) salen species which undergoes a one-electron reduction to liberate cobalt(II) salen and the dionate. In addition, cobalt(II) salen reacts with molecular oxygen to give cobalt(III) salen and superoxide, and the latter reduces 3-chloro-2,4-pentanedione to form chloride ion, the 2,4-pentanedion-3-yl radical, and molecular oxygen.
Thermal constraints on the early history of the H-chondrite parent body reconsidered

Abstract Reconstructions of the early thermal history of the H-chondrite parent body have focused on two competing hypotheses. The first posits an undisturbed thermal evolution in which the degree of metamorphism increases with depth, yielding an “onion-shell” structure. The second posits an early fragmentation–reassembly event that interrupted this orderly cooling process. Here, we test these hypotheses by collecting a large number of previously published closure age and cooling rate data and comparing them to a suite of numerical models of thermal evolution in an idealized parent body. We find that the onion-shell hypothesis, when applied to a parent body of radius 75–130 km with a thermally insulating regolith, is able to explain 20 of the 21 closure age data and 62 of the 71 cooling rates. Furthermore, six of the eight meteorites for which multiple data (at different temperatures) are available, can be accounted for by onion-shell thermal histories. We therefore conclude that no catastrophic disruption of the H-chondrite parent body occurred during its early thermal history. The relatively small number of data not explained by the onion-shell hypothesis may indicate the formation of impact craters on the parent body which, while large enough to excavate all petrologic types, were small enough to leave the parent body largely intact. Impact events fulfilling these requirements would likely have produced transient crater diameters at least 30% of the parent body diameter.
Language games of reciprocity

Abstract This paper attempts to explicate the meaning of reciprocate in economics. I first show using innate universal concepts that the definition of reciprocate appears to be circular. This circularity problem vanishes, however, when the context of the interaction is introduced as the inextricable link between the act of reciprocating and the intention to reciprocate. Applying Wittgenstein's concept of a language game, I also discuss the claim that social preferences have no agency. Rather, it is an individual's observable action that constitutes agency in reciprocity. My thesis is that social preferences emanate from the actions of social individuals and not vice versa.
Excitation transfer by chlorophyll a in monolayers and the interaction with chloroplast glycolipids.

In mixed monolayers with purified chloroplast glycolipids and other colorless lipids, chlorophyll a fluorescence exhibits a decrease in quantum efficiency with increasing chlorophyll concentration. The fluorescence, which is strongly polarized in dilute films, becomes progressively depolarized as the area fraction of chlorophyll increases, and it is completely depolarized in a pure chlorophyll a monolayer. The observed behavior is consistent with an inductive resonance mechanism of energy transfer among the chlorophyll molecules with a critical transfer distance of 20–90 A, depending on the model chosen for the energy transfer mechanism. The purified glycolipids–mono-and digalactosyl diglycerides and sulfoquinovodiglyceride–separately form stable, compressible monolayers of the liquid-expanded type on an aqueous subphase and in an atompshere of nitrogen. At maximum compression the three glycolipids occupy areas of 55, 80 and 47 A2-molecule-1, respectively, in the monolayer. Mixed monolayers of chlorophyll a with, separately, the monogalactolipid and the sulfolipid behave upon compression as two-dimensional solutions. The fluorescence polarization at high chlorophyll concentrations in mixed monolayers indicates that several of the lipid diluents facilitate local ordering of the pigment molecules.
Rutherford backscattering and transmission electron microscopy analysis of Al/AlxOy vacuum-deposited laminates

Abstract Rutherford backscattering spectrometry and transmission electron microscopy have been used to characterize laminates of Al/AlxOy produced by a pulsed gas process in an electron beam gun deposition system. RBS analysis confirmed the chemical periodicity of the film and indicated that the oxygen-containing layers were close to Al2O3 in stoichiometry. Transmission microscopy confirmed the structural periodicity of the laminates and allowed the measurement of oxide layer thickness.
Disease pattern in cranial and large-vessel giant cell arteritis.

Objective To identify variables that distinguish large-vessel giant cell arteritis (GCA) with subclavian/axillary/brachial artery involvement from cranial GCA. Methods Seventy-four case patients with subclavian/axillary GCA diagnosed by angiography and 74 control patients with temporal artery biopsy–proven GCA without large vessel involvement matched for the date of first diagnosis were identified. Pertinent initial symptoms, time delay until diagnosis, and clinical symptoms, as well as clinical and laboratory findings at the time of diagnosis, were recorded by retrospective chart review. Expression of cytokine messenger RNA in temporal artery tissue from patients with large-vessel and cranial GCA was determined by semiquantitative polymerase chain reaction analysis. Distribution of disease-associated HLA–DRB1 alleles in patients with aortic arch syndrome and cranial GCA was assessed. Results The clinical presentation distinguished patients with large-vessel GCA from those with classic cranial GCA. Upper extremity vascular insufficiency dominated the clinical presentation of patients with large-vessel GCA, whereas symptoms related to impaired cranial blood flow were infrequent. Temporal artery biopsy findings were negative in 42% of patients with large-vessel GCA. Polymyalgia rheumatica occurred with similar frequency in both patient groups. Large-vessel GCA was associated with higher concentrations of interleukin-2 gene transcripts in arterial tissue and overrepresentation of the HLA–DRB1*0404 allele, indicating differences in pathogenetic mechanisms. Conclusion GCA is not a single entity but includes several variants of disease. Large-vessel GCA produces a distinct spectrum of clinical manifestations and often occurs without involvement of the cranial arteries. Large-vessel GCA requires a different approach to the diagnosis and probably also to treatment.
The Barred Antshrike (Thamnophilus doliatus) on Trinidad and Tobago: habitat niche expansion of a generalist forager.

The Barred Antshrike (Thamnophilus doliatus) is the most abundant insectivorous foliage-gleaning vertebrate in both closed rain forest and second growth on the island of Tobago. However, it occurs only in second growth on the larger neighbor island of Trinidad and on the neotropical mainland.Habitat niche expansion into Tobago forest has been facilitated by several behavioral traits which set the antshrike apart from other foliage-gleaners of forest and second growth on Tobago. The antshrike captures a higher diversity of foliage, branch & trunk, and terrestrial arthropods. It forages over a wider range of heights and under a wider variety of crown cover situations than any of its closest ecological counterparts on Tobago. The antshrike also takes a wider range of prey sizes and regularly uses additional food sources, including fruit and ants, not taken by other guild members. The broad foraging niche of the antshrike enables it to breed during many times of the year when other narrower-niched foliage-gleaners do not.On Trinidad, although the most common foliagegleaner in second growth, the antshrike was not observed in adjacent closed rain forest. Several facts suggest that diffuse competition may be excluding antshrikes from Trinidad forest: 1) a general pattern of rarity or absence in other parts of its range where there are more guild members; 2) more species and individuals of foliagegleaners with an overall higher biomass in Trinidad forest than in Tobago forest; 3) foliage arthropod resources are significantly (1.7x) lower in Trinidad forest than Tobago forest, suggesting that Trinidad forest guild members may be depressing the quantity of important resources for antshrikes; and 4) Trinidad forest species with the highest foraging similarity to antshrikes have a greater precentage of prey captures comprised of relatively specialized attack behaviors than do Tobago forest antshrikes.Foraging generalists like the Barred Antshrike appear to expand or contract their habitat niches depending upon the number of ecologically similar species in a given habitat. They may occur in high densities in habitats typically foreign to them provided competitors are few and there is sufficient food to supply their catholic requirements.
Selective removal of promoter nucleosomes by the RSC chromatin-remodeling complex

Purified chromatin rings, excised from the PHO5 locus of Saccharomyces cerevisiae in transcriptionally repressed and activated states, were remodeled with RSC and ATP. Nucleosomes were translocated, and those originating on the promoter of repressed rings were removed, whereas those originating on the open reading frame (ORF) were retained. Treatment of the repressed rings with histone deacetylase diminished the removal of promoter nucleosomes. These findings point to a principle of promoter chromatin remodeling for transcription, namely that promoter specificity resides primarily in the nucleosomes rather than in the remodeling complex that acts upon them.
Kinetic isotope studies of the gas-phase reaction (H,D,Mu)+HBr→(H,D,Mu)H+Br

Reaction rate constants and kinetic isotope effects for the gas-phase reaction A + HBr→AH+Br, where A can be H, D, or Mu, have been studied using variational transition state theory with semiclassical tunneling on two semiempirical potential energy surfaces and a newab initio surface. The rate constants and kinetic isotope effects are compared to experimental results. This comparison is used to test the potential energy surfaces, to determine which regions of the potential energy surface control the reaction rates and the kinetic isotope effects, and to learn whether or not any of the potential energy surfaces is accurate for a wide enough range of features to predict both the reaction rate constants and the kinetic isotope effects for this chemical system.
Probabilities on Finite Models

Let be a finite set of (nonlogical) predicate symbols. By an -structure, we mean a relational structure appropriate for . Let be the set of all -structures with universe {1, …, n}. For each first-order -sentence σ (with equality), let μn(σ) be the fraction of members of for which σ is true. We show that μn(σ) always converges to 0 or 1 as n → ∞, and that the rate of convergence is geometrically fast. In fact, if T is a certain complete, consistent set of first-order -sentences introduced by H. Gaifman [6], then we show that, for each first-order -sentence σ, μn(σ) →n 1 iff T ⊩ ω. A surprising corollary is that each finite subset of T has a finite model. Following H. Scholz [8], we define the spectrum of a sentence σ to be the set of cardinalities of finite models of σ. Another corollary is that for each first-order -sentence a, either σ or ˜σ has a cofinite spectrum (in fact, either σ or ˜σ is “nearly always“ true).Let be a subset of which contains for each in exactly one structure isomorphic to . For each first-order -sentence σ, let νn(σ) be the fraction of members of which a is true. By making use of an asymptotic estimate [3] of the cardinality of and by our previously mentioned results, we show that vn(σ) converges as n → ∞, and that limn νn(σ) = limn μn(σ).If contains at least one predicate symbol which is not unary, then the rate of convergence is geometrically fast.
Reply to Comment on ‘Supercooled and glassy water’

In a recent review on supercooled and glassy water (Debenedetti 2003 J. Phys.: Condens. Matter 15 R1669) I used a thermodynamic consistency argument to rule out the possibility, proposed originally by Speedy (1982 J. Phys. Chem. 86 982), that the spinodal curve for superheated liquid water can retrace to positive pressure. The argument is based on the impossibility that a thermodynamic state other than a critical point be a limit of stability (i.e., a point along a spinodal line) and simultaneously coexist with another phase. Speedy's comment offers a counter-example involving the freezing transition to argue that a thermodynamic state can in fact be a limit of stability (spinodal) and simultaneously coexist with a different phase (i.e., a non-critical point along the phase coexistence locus). Here I argue that instability to infinitesimal density fluctuations and coexistence with a different phase are mutually exclusive conditions.
Approximation In The Mean By Rational Functions

In this paper we proved that for a large class of compact subsetsK in the complex plane,R(K) is dense inLq(μ) if and only if the set of analytic bounded point evaluations forRq(K, μ) is empty. As a consequence, we showed that this result is true for allK ifR(K) is replaced byA(K). Our main result includes the corresponding result of James Thomson for polynomials approximation as such a special case thatK is a disk.
Aqueous-phase aminolysis : Approach for the analysis of epoxides in water

Trace concentrations of small soluble epoxides are suspected byproducts of drinking water ozonation. However, adequate characterization of epoxide formation is currently limited by the lack of suitable analytical methods to target these chemicals in dilute, but complex aqueous solutions. One potential approach is presented here based on aqueous-phase aminolysis. The method also employs solid-phase extraction, silylation of the solvent extract, and analysis by gas chromatography−mass spectrometry. This approach is demonstrated to be effective for the selective analysis of the epoxides 1,2-epoxybutane, epichlorohydrin, and epifluorohydrin in water with optimized method detection limits of 5−10 ng/L.
What Should We Do with a Feminist Educational Theory When We Have One? A Response to Audrey Thompson

I have recently published Cultural Miseducation (Martin, 2002), a book in which I develop what I call a "cultural wealth" approach to education. Instead of focusing on individual learners-or classes of learners-this approach focuses on the wealth a culture possesses; or rather, it focuses on the stock a culture possesses, a more neutral term that encompasses both assets and liabilities. Instead of asking how children or adults learn, whether they learn what they are expected to, and what they need to know to be good citizens, and so forth, it asks which portions of stock are being preserved and transmitted to the next generation, whether some items of stock are getting lost in the process, and so forth. It may be wondered why I care about such questions. Isn't it the case that most people who claim to be worried about the transmission of cultural wealth-or the cultural heritage, as they would say-have very conservative agendas? Yes they do: defining culture and cultural wealth in very narrow, really elitist terms, as, for instance, "the classics of the West" or "the higher learning," they then blame schools for failing to transmit these things and for passing down, instead, knowledge that falls outside their definitions. Need I say that the research on women and education that Audrey Thompson discusses in "Caring in Context: Four Feminist Theories on Gender and Education" falls outside the standard, narrow definitions of culture and cultural wealth? As such, the conservatives say it does not deserve to be passed down to future generations. Reject those definitions, however, and research about women (all women, not only white middleclass heterosexual women) and about minority men-and much, much
Second cancers are killing us

As a Clinical Associate in the Pharmacology Section in the National Cancer Institute in 1967, virtually all of the patients referred to me had far-advanced, metastatic cancers, whether of the breast, colon, prostate, or lung. Treatment choices for disseminated disease were limited to a half dozen
Too much natural history, or too little?

Abstract A number of commentators have recently expressed concern about the fate of both natural history and naturalists in the modern world. In this essay I examine those concerns from a historical perspective. From this standpoint, I conclude that natural history is alive and well, but its future critically depends upon conceptual infusions from adjacent disciplines. Naturalists are proliferating rather than dying out. Copyright 2003 Published by Elsevier Ltd on behalf of The Association for the Study of Animal Behaviour.
Evaluation of the Pulse Ohmic Non-Linearity Technique as a Reliability Tool for Predicting Susceptibility to Electromigration Damage

The degree of correlation between time to failure by electromigration stressing and pulse ohmic - non-linearity was found to depend markedly on the stress conditions. Only the highest stress and highest joule heating resulted in good correlation. Also, a simple resistance measurement was found to correlate as well with time to failure as pulse non-linearity. It was concluded that pulse non-linearity techniques are of limited usefulness as a reliability tool for all but those applications where severe joule heating is present.
Effect of timing of morphine administration during remifentanil‐based anaesthesia on early recovery from anaesthesia and postoperative pain

Background Since the time to peak analgesic effect of intravenous morphine can be longer than 40–60 min in volunteers, the goal of this study was to evaluate the effect of the timing of intraoperative morphine administration on early postoperative pain. Methods A total of 120 adult patients undergoing laparoscopic cholecystectomy were studied. Anaesthesia was induced with remifentanil and etomidate and maintained with remifentanil and sevoflurane/nitrous oxide. Morphine 150 µg kg–1 was given randomly at three different times during surgery, and a fourth group received placebo. Times to eyes opening and extubation were measured, and pain was evaluated in the post‐anaesthesia care unit (PACU) using a visual analogue scale (VAS). Morphine 2–3 mg was given when the VAS score was ≥50 mm. The four groups were, according to the time elapsed from morphine administration to the end of surgery, group 1 (n=30): placebo; group 2 (n=33): 40 min. Results Recovery from anaesthesia and pain scores were similar in all groups. However, mean ( sd ) morphine consumption was 5.7 (4.7) mg in group 1, 4.4 (4.2) mg in group 2, 4.7 (4.7) mg in group 3, and 2.2 (4.0) mg in group 4 (P Conclusions The timing of intraoperative morphine administration did not affect the early recovery from anaesthesia. However, the reduction in the number of patients requiring morphine in the PACU when morphine had been given more than 40 min before the end of surgery supports this practice, rather than administration closer to the end of surgery. Br J Anaesth 2002; 88: 814–8
Acquisition of Information Online: Knowledge, Navigation and Learning Outcomes

Research suggests that the World Wide Web (WWW) represents the intersection of at least two domains: content and technology. This investigation was designed to examine the relationship between prior knowledge and WWW browsing outcomes (i.e., navigation behavior and knowledge gain) within the context of a genetics Web site. Students randomly assigned to a treatment group were given a prereading activity designed to increase their prior knowledge within the domain of genetics. This group demonstrated significantly higher learning outcome scores than students in the control group. The treatment group also spent more time browsing, viewed more multimedia resources,and utilized more in-text embedded links. These results and others are interpreted in terms of instructional decisions and recommendations for future research.
Transcatheter occlusion of patent ductus arteriosus: Which method to use and which ductus to close

Abstract Many devices have been developed for transcatheter occlusion of PDA. Bulkiness of the device, complexity of the procedure, and significant residual complications make the majority of the devices unsuitable for routine clinical use. Although no randomized comparative clinical trials exist, on the basis of published literature and my personal experience, coil occlusion may be best suited to close small ducts (≤3.5 mm) and the adjustable buttoned device may be most appropriate for large PDAs (>3.5 mm). Clinical trials on larger patient populations than are currently available and long-term follow-up are necessary to further support these recommendations. Indications for transcatheter closure should be exactly as those used for surgical closure: PDA with audible continuous murmur with echo Doppler confirmation. The so-called silent ducts need not be closed.
Stochastic catastrophe models and multimodal distributions

Nonlinear models such as have been appearing in the applied catastrophe theory literature are almost universally deterministic, as opposed to stochastic (probabilistic). The purpose of this article is to show how to convert a deterministic catastrophe model into a stochastic model with the aid of several reasonable assumptions, and how to calculate explicitly the resulting multimodal equilibrium probability density. Examples of such models from epidemiology, psychology, sociology, and demography are presented. Lastly, a new statistical technique is presented, with which the parameters of empirical multimodal frequency distributions may be estimated.
The Effect of Finite Rate Feedback on CDMA Signature Optimization and MIMO Beamforming Vector Selection

We analyze the effect of finite rate feedback on code-division multiple-access (CDMA) signature optimization and multiple-input multiple-output (MIMO) beamforming vector selection. In CDMA signature optimization, for a particular user, the receiver selects a signature vector from a codebook to best avoid interference from other users, and then feeds the corresponding index back to the specified user. For MIMO beamforming vector selection, the receiver chooses a beamforming vector from a given codebook to maximize the instantaneous information rate, and feeds back the corresponding index to the transmitter. These two problems are dual: both can be modeled as selecting a unit norm vector from a finite size codebook to ldquomatchrdquo a randomly generated Gaussian matrix. Assuming that the feedback link is rate limited, our main result is an exact asymptotic performance formula where the length of the signature/beamforming vector, the dimensions of interference/channel matrix, and the feedback rate approach infinity with constant ratios. The proof rests on the large deviations of the underlying random matrix ensemble. Further, we show that random codebooks generated from the isotropic distribution are asymptotically optimal not only on average, but also in probability.
Computer "Experiments" on Classical Fluids. II. Equilibrium Correlation Functions

Abstract : Equilibrium correlation functions for a dense classical fluid are obtained by integrating the equation of motion of a system of 864 particles interacting through a Lennard-Jones potential. The behaviour of the correlation function at large distance, and that of its Fourier transform at large wave number are discussed in detail and shown to be related to the existence of a strong repulsion in the potential. A simple hard sphere model is shown to reproduce very well the Fourier transform of those correlations functions at high density, the only parameter of the model being the diameter a of the hard spheres. (Author)
Annealing effects on the polarity of stored charge of BaTiO/sub 3/ films on Si

A high quality BaTiO/sub 3//p-Si interface was achieved at substrate temperature of 500/spl deg/C by using RF magnetron sputtering. In-situ annealing at the same temperature was carried out to study the charge behavior of BaTiO/sub 3/ films on Si substrate. Depending on the annealing oxygen pressure and annealing condition, both polarities of effective oxide charge in the metal-ferroelectric-semiconductor, Au/BaTiO/sub 3//p-Si, structure was observed. It is believed that the density of electronic states, generated at the interface due to the asymmetry of the structure between BaTiO/sub 3/ and Si substrate, and the positive oxide charges, depending on the degree of the metal-oxygen reaction for different annealing oxygen pressures and annealing durations, determines the behavior of oxide charge.
Preliminary report on the HEAO hole in the ionosphere

The launch of NASA's third High-Energy Astrophysical Observatory (HEAO-C) at 0528 UT on September 20, 1979, by an Atlas-Centaur rocket produced an extraordinary opportunity to monitor a large-scale, artificially induced depletion of the earth's ionosphere [Mendillo et al., 1979]. The resultant plasma hole, an effect caused by rapid chemical processes between the rocket's exhaust plume of H2O and H2 and the ionospheric constituents (O+ and e−), was detected by an extensive network of temporary observatories set up specifically for the event. The purpose of this report is to provide a brief summary of the initial results obtained, as described at the recent workshop/symposium ‘Preliminary Evaluation of the Ionospheric Disturbances Associated with the HEAO-C Launch, With Applications to the SPS Environmental Assessment’ held at Boston University's Osgood Hill Conference Center, November 11–13, 1979.
Organizational Politics and Employee Attendance

Organizational politics has been conceptualized as a source of stress and conflict in the work environment, with the potential for dysfunctional outcomes at both the individual and organizational level. One possible consequence of politics is the exercise by employees of withdrawal behaviors, particularly absenteeism. Further, the likelihood of negative outcomes may be substantially enhanced by the lack of understanding. The present study investigated the extent to which such understanding, measured as tenure working for supervisor, moderated the erceptions of politics-employee attendance relationship. Moderated regression results (after controlling for quality of supervisor-subordinate relationship) provided support for the hypothesis, demonstrating that under conditions of lower tenure working for supervisor, increases in perceptions of politics were associated with lower attendance, whereas no relationship was found between politics and attendance under conditions of higher tenure working for superviso...
PARM: a power-aware message scheduling algorithm for real-time wireless networks

Real-time applications in wireless networks are emerging in multimedia product and design. However, conventional real-time message scheduling algorithms generally do not take energy efficiency into account when making scheduling decisions. In this paper, we address the issue of scheduling real-time messages in wireless networks subject to timing and power constraints. A novel message scheduling scheme, or PARM (Power-aware Real-time Message), is developed to generate optimal schedules that minimize both power consumption and the probability of missing deadlines for real-time messages. With a power-aware scheduling policy in place, the proposed PARM scheme is very energy efficient. In addition, we extended a power consumption model to calculate power consumption rates in accordance to message transmission rates. Experimental results show that PARM significantly improves the performance in terms of missed rate, energy efficiency, and overall performance over four baseline message scheduling schemes.
STIMULUS-DEPENDENT MODULATION OF SPIKE BURST LENGTH IN CAT STRIATE CORTICAL CELLS

DeBusk, B. C., E. J. DeBruyn, R. K. Snider, J. F. Kabara, and A. B. Bonds. Stimulus-dependent modulation of spike burst length in cat striate cortical cells. J. Neurophysiol. 78: 199–213, 1997. Bur...
Elevated Concentrations of Ethinylestradiol, 17β-Estradiol, and Medroxyprogesterone have Little Effect on Reproduction and Survival of Ceriodaphnia dubia

Wastewater effluent contains synthetic and natural hormones, often in complex mixtures, that may be associated with reproductive abnormalities in fish and other aquatic biota. We exposed the sentinel invertebrate Ceriodaphnia dubia to the natural estrogen 17β-estradiol (E2), a synthetic estrogen, ethinylestradiol (EE2), and a synthetic progestin, medroxyprogestone in a 7-day test. These compounds had no significant effect on reproduction or survival even at 106 times the concentrations at which reproductive effects have been documented in several fish species. C. dubia is routinely used for screening the toxicity of wastewater effluent. However, in the standard chronic 7-day exposure the endpoints of survival and reproduction were insensitive to several synthetic and natural vertebrate hormones. The C. dubia 7-day chronic toxicity test is probably not a useful monitoring tool for vertebrate hormones and their pharmaceutical analogs unless other sensitive endpoints such as maturation rates, molt frequency, and offspring sex ratios are incorporated in a practical manner.
Growth rate and potential climate record from a rhodolith using 14C accelerator mass spectrometry

Rhodoliths, free-living calcareous red algae, create large and diverse habitats worldwide. Although these plants are abundant and ecologically important, little is known about their growth rate. We determined the growth rate for an individual rhodolith, Lithothamnium crassiusculum,from the southern Gulf of California through 14 C analysis using accelerator mass spectrometry (AMS) to be 0.6 mm yr 21 . This growth rate suggests large L. crassiusculum, which have been found with radii in excess of 6 cm, may live over 100 yr. Declines in the D 14 C record associated with the large El Nino events of 1957, 1982, and 1992 indicate 14 C analysis may lead to identification of important climate events in the more distant past. The ability to determine changes in past ocean circulation related to changes in past climatic conditions through AMS 14 C analysis of rhodoliths would increase the geographic range of available climate records from the tropical oceans to the entire global ocean and potentially allow for the determination of past climate conditions from rhodoliths in fossil beds. Rhodoliths, red, nongeniculate calcareous algae, occupy large areas of the world's oceans, forming the basis of di- verse and ecologically important communities (Bosence 1983; Foster et al. 1997). However, little is known about the rate at which these communities develop, their rate of re- covery after natural or anthropogenic disturbances, or their effects on the global carbon budget. Because some rhodo- liths are long lived, they also have the potential to provide information on past oceanic conditions. As they grow, these plants deposit calcium carbonate, which should contain chemical and isotopic records reflecting environmental con- ditions. Previous isotopic studies on coral and mollusks found that the amount of 14 C deposited as a part of the total carbon in biogenic carbonate records the 14 C concentration in the ocean water surrounding the organism (e.g., Druffel and Linick 1978; Nozaki et al. 1978; Druffel and Suess 1983). This type of 14 C record should also be found in the carbonate of rhodoliths and can potentially be used as a re- cord of climate variation. Rhodoliths are found in many locations and environ- ments around the world, ranging from polar deep water to tropical shallows (Bosence 1983). In the subtropical Gulf
Pathogenesis of Chronic Hyperglycemia: From Reductive Stress to Oxidative Stress

Chronic overnutrition creates chronic hyperglycemia that can gradually induce insulin resistance and insulin secretion impairment. These disorders, if not intervened, will eventually be followed by appearance of frank diabetes. The mechanisms of this chronic pathogenic process are complex but have been suggested to involve production of reactive oxygen species (ROS) and oxidative stress. In this review, I highlight evidence that reductive stress imposed by overflux of NADH through the mitochondrial electron transport chain is the source of oxidative stress, which is based on establishments that more NADH recycling by mitochondrial complex I leads to more electron leakage and thus more ROS production. The elevated levels of both NADH and ROS can inhibit and inactivate glyceraldehyde 3-phosphate dehydrogenase (GAPDH), respectively, resulting in blockage of the glycolytic pathway and accumulation of glycerol 3-phospate and its prior metabolites along the pathway. This accumulation then initiates all those alternative glucose metabolic pathways such as the polyol pathway and the advanced glycation pathways that otherwise are minor and insignificant under euglycemic conditions. Importantly, all these alternative pathways lead to ROS production, thus aggravating cellular oxidative stress. Therefore, reductive stress followed by oxidative stress comprises a major mechanism of hyperglycemia-induced metabolic syndrome.
The Use of Concept Maps to Support Human-System Integration Requirements: Highlighting the Human Touch Points

Concept maps are graphical representations of a body of knowledge and the relationships between parts of that knowledge. Concept maps help people see relationships among ideas and the range of topics to be considered in a concise form. The project discussed in this paper uses concept maps to support the design and development of a human-system integration (HSI) assessment tool to help system acquisition staff develop HSI requirements, to review deliverables for completeness, and to conduct or review HSI evaluations during the system acquisition process. Concept maps, used in this novel way, can help ensure that the essential aspects of a system or a problem are captured. Exemplar systems to be mapped are the F-15E, Stratcom's Global Operations Center (GOC), and the Predator unmanned aerial system.