cssi/SciSciGPT-SciSciNet huggingface dataset:
DIFFUSION, INTERMITTENCY, AND NOISE-SUSTAINED METASTABLE CHAOS IN THE LORENZ EQUATIONS: EFFECTS OF NOISE ON MULTISTABILITY

Multistability is an interesting phenomenon of nonlinear dynamical systems. To gain insights into the effects of noise on multistability, we consider the parameter region of the Lorenz equations that admits two stable fixed point attractors, two unstable periodic solutions, and a metastable chaotic "attractor". Depending on the values of the parameters, we observe and characterize three interesting dynamical behaviors: (i) noise induces oscillatory motions with a well-defined period, a phenomenon similar to stochastic resonance but without a weak periodic forcing; (ii) noise annihilates the two stable fixed point solutions, leaving the originally transient metastable chaos the only observable; and (iii) noise induces hopping between one of the fixed point solutions and the metastable chaos, a three-state intermittency phenomenon.
Alfalfa Yield and Soil Phosphorus Increased with Topdressed Granular Compared with Fluid Phosphorus Fertilizer

Fluid P fertilizers are commonly applied to established alfalfa (Medicago saliva L.) despite their higher cost compared to granular forms. The objectives of this experiment were to compare effects of fluid and granular P fertilizer on alfalfa yield, and availability and movement of P in the soil. The P fertilizers compared were fluid ammonium polyphosphate (APP, 10-34-0) applied in irrigation water and granular monoammonium phosphate (MAP, 11-52-0) topdressed and incorporated by flood irrigation on a calcareous soil at Maricopa, AZ. Fertilizer P was applied each December at rates of 1,2,3, and 5 g P m -2 . The soil was sampled about 1 mo later. In the first four cuttings of the first year, hay yields were 1358 g m -2 for APP and 1501 g m -2 for MAP. No differences in yield due to P source were measured in the remaining four cuttings of the first year, or in any cutting the second or third year. In the surface soil (0-7.6 cm), the bicarbonate extractable soil P averaged 44 mg kg -1 for APP and 7.1 for MAP. The depth of movement of the fertilizers was similar except in the first year where MAP moved deeper into the soil profile than APP. In this study, the higher cost of fluid APP compared with granular MAP was not recovered by increased yield. However, at low P rates, water-run APP may be more economical than topdressed MAP due to its low application cost.
Seed development in cotton: feasibility of a hormonal role for abscisic Acid in controlling vivipary.

In maturing cotton (Gossypium hirsutum L.) fruits, embryos acquire the capacity to germinate in vitro about 16 days before fruit maturity and dehiscence. Vivipary is believed to be prevented by abscisic acid (ABA) originating in the seed coat and diffusing to the embryo (the Ihle-Dure hypothesis). Although endogenous ABA levels are much greater in embryos than in seed coats during the period of germinability, in «donor-receiver» experiments movement of (14)C-ABA is strongly polar in favor of the embryo. Compartmental efflux analysis showed that embryos contain 90% of their ABA in a vacuole-like compartment and an insignificant amount in a cytoplasm-like compartment. In contrast, seed coats have only 60% of their ABA in the «vacuole» and a much greater fraction than embryos in the «cytoplasm». As a result, efflux across the plasma membranes of seed coat cells is much faster than from embryo cells. Increasing external pH strongly inhibits ABA uptake by isolated seed coats and embryos, indicating a role of pH gradients in its partitioning (i.e. ABA tends to be transferred from acidic to alkaline compartments). Aqueous extracts of seed coats are much more acidic than those of embryos. This difference, presumably originating in the «vacuoles», can account for the different intracellular distributions of ABA in the two tissues and therefore can account for the polarity of ABA diffusion between tissues. The results implicate intracellular pH gradients in the control of ABA movement between seed coat and embryo. Demonstration of the feasibility of inward ABA movement, despite apparently unfavorable diffusion gradients, provides direct support for the Ihle-Dure hypothesis.
Surface functionalization of magnetic iron oxide nanoparticles for MRI applications – effect of anchoring group and ligand exchange protocol

Hydrophobic magnetite nanoparticles synthesized from thermal decomposition of iron salts must be rendered hydrophilic for their application as MRI contrast agents. This process requires refunctionalizing the surface of the nanoparticles with a hydrophilic organic coating such as polyethylene glycol. Two parameters were found to influence the magnetic behavior and relaxivity of the resulting hydrophilic iron oxide nanoparticles: the functionality of the anchoring group and the protocol followed for the functionalization. Nanoparticles coated with PEGs via a catecholate-type anchoring moiety maintain the saturation magnetization and relaxivity of the hydrophobic magnetite precursor. Other anchoring functionalities, such as phosphonate, carboxylate and dopamine decrease the magnetization and relaxivity of the contrast agent. The protocol for functionalizing the nanoparticles also influences the magnetic behavior of the material. Nanoparticles refunctionalized according to a direct biphasic protocol exhibit higher relaxivity than those refunctionalized according to a two-step procedure which first involves stripping the nanoparticles. This research presents the first systematic study of both the binding moiety and the functionalization protocol on the relaxivity and magnetization of water-soluble coated iron oxide nanoparticles used as MRI contrast agents.
Single‐Walled Carbon Nanotube/Metalloporphyrin Composites for the Chemiresistive Detection of Amines and Meat Spoilage

Chemiresistive detectors for amine vapors were made from single-walled carbon nanotubes by noncovalent modification with cobalt meso-arylporphyrin complexes. We show that through changes in the oxidation state of the metal, the electron-withdrawing character of the porphyrinato ligand, and the counteranion, the magnitude of the chemiresistive response to ammonia could be improved. The devices exhibited sub-ppm sensitivity and high selectivity toward amines as well as good stability to air, moisture, and time. The application of these chemiresistors in the detection of various biogenic amines (i.e. putrescine, cadaverine) and in the monitoring of spoilage in raw meat and fish samples (chicken, pork, salmon, cod) over several days was also demonstrated.
Elevated-temperature fatigue crack growth

The fatigue crack growth behavior of MAR-M200 single crystals was examined at 982 °C. Using tubular specimens, fatigue crack growth rates were determined as functions of crystallographic orientation and the stress state by varying the applied shear stress range-to-normal stress range ratio. Neither crystallographic orientation nor stress state was found to have a significant effect on crack growth rate when correlated with an effective ΔK which accounted for mixed-mode loading and elastic anisotropy. For both uniaxial and multiaxial fatigue, crack growth generally occurred normal to the principal stress direction and in a direction along which ΔK II vanished. Consequently, the effective ΔK was reduced to ΔKI and the rate of propagation was controlled by ΔK I only. The through-thickness fatigue cracks were generally noncrystallographic with fracture surfaces exhibiting striations in the [010], [011], and [111] crystals, but striation-covered ridges in the [211] specimen. These fracture modes are contrasted to crystallographic cracking along slip bands observed at ambient temperature. The difference in cracking behavior at 25 and 982 °C is explained on the basis of the propensity for homogeneous, multiple slip at the crack tip at 982 °C. The overall fracture mechanism is discussed in conjunction with Koss and Chan’s coplanar slip model.
Improved viscoelastic damping for earthquake-resistant wood structures

In this work viscoelastic polymeric damping material was studied for its ability to damp out vibrations in wood structures (houses). This is accomplished by placing a thin layer of the material between wood stud and sheathing material. Damping performance of three individual polymers was obtained and compared to two types of blends of the materials. Placing the strips of material next to each other (parallel arrangement for shear) rather than on top of each other (series arrangement for shear), gave improved damping results over a wider temperature range relative to the single polymers. This is attributed to the widening of the damping peak by combining the materials. This is expected to be useful in earthquake-resistant wooden structures, such as housing, by delaying collapse and by absorbing energy, thereby increasing likelihood of saving the lives of the inhabitants.
The Paradigm Shift in Organizational Research

The creation and development of theory and methods used in the study of organizations is predominantly carried out grounded in the positivist paradigm â€“ epistemological and methodological assumptions similar to those of the natural sciences. This essay looks at the limitations of that paradigm for the study of human organizations and the benefits of relativist, humanist and post-modern assumptions, theory and methods. Limitations of the predominant paradigm are taken up by analyzing basic assumptions â€“ objectivity, generality, empiricism, and linearity. The benefits of a more inclusive paradigm are reviewed in terms of two topic areas: Organizational learning and decision making, and financial markets and price distortion.
Upper Mantle Heterogeneity beneath North America from Travel Time Tomography with Global and USArray Transportable Array Data

The large volume of broadband waveforms that are being acquired by USArray (http://www.iris.edu/USArray/), the seismology component of the national Earth science program EarthScope (http://www.earthscope.org/), offer unique opportunities for seismic imaging. Constraining structures on a range of length scales and understanding their physical and chemical causes is a prerequisite for understanding the relationship between near surface and deeper mantle processes. One can expect that, eventually, full wave tomography ( e.g. , De Hoop and van der Hilst 2005; De Hoop et al. 2006; Tromp et al. 2005; Zhao and Jordan 2006) with broadband USArray waveforms will produce superior insight into the structure of the mantle beneath North America, but linearized tomographic inversion of phase arrival time data readily yields exciting results in regions where data from dense seismograph networks is available. We will use travel times from the transportable component of USArray, hereinafter referred to as USArrayTA, and from other sources, such as the EHB data base (Engdahl et al. 1998), to constrain 3-D mantle heterogeneity beneath North America. Tomographic images based on USArrayTA data will help us understand first-order geological structure of and processes in the mantle beneath North America. Examples include, but are not restricted to: 1) the transition from the stable continental lithosphere at the center of the North American continent to the tectonically active domains farther west, 2) the Cascadian subduction system, 3) the Yellowstone hotspot, and 4) the relationship between current and past episodes of subduction and upper mantle upwellings and processes deeper in the mantle. Before the advent of USArrayTA, insight into mantle structure beneath the western United States was obtained either from pieced-together regional P -wave studies ( e.g. , figure 1A, after Dueker et al. 2001) or from global travel time or surface wave tomography (figures 1B, C, and D, …
Quasi-continuous-wave operations of quantum cascade lasers

In this paper, quasi-continuous-wave (quasi-CW) operation of quantum cascade lasers (QCLs) is studied. A group of strain-balanced InGaAs/InAlAs QCLs emitting around λ~4.8μm were used in the experiment. QCLs were tested at different driving conditions (i.e. pulsed mode, CW mode and quasi-CW mode) at various temperatures. Experimental measurements show that thermal effect plays an important role in deteriorating QCL performance. This is especially true at high temperatures. At low temperature (~100K), L-I curves with different pulse widths exhibit no significant difference. While at a higher temperature (~200K), we observed that the longer the pulse width, the lower the roll-over power and the worse the laser performance. At 100K, the roll-over power increases as duty cycle increases until it reaches CW operation, indicating that the thermal generation difference for quasi-CW mode and CW mode is negligible. At 200K, however, a maximum roll-over power is about 50mW at duty cycle of 65% corresponding to a CW roll-over power of 40mW. It reveals that at high temperature, quasi-CW operation generates less heat and more average output power. Therefore, quasi-CW operation is obviously a favorable way to achieve high performance operations at high temperature.
Drosophila GABAB receptors are involved in behavioral effects of γ-hydroxybutyric acid (GHB)

Abstract γ-hydroxybutyric acid (GHB) can be synthesized in the brain but is also a known drug of abuse. Although putative GHB receptors have been cloned, it has been proposed that, similar to the behavior-impairing effects of ethanol, the in vivo effects of pharmacological GHB may involve metabotropic γ-aminobutyric acid (GABA) GABAB receptors. We developed a fruitfly (Drosophila melanogater) model to investigate the role of these receptors in the behavioral effects of exogenous GHB. Injecting GHB into male flies produced a dose-dependent motor impairment (measured with a computer-assisted automated system), which was greater in ethanol-sensitive cheapdate mutants than in wild-type flies. These effects of pharmacological concentrations of GHB require the presence and activation of GABAB receptors. The evidence for this was obtained by pharmacological antagonism of GABAB receptors with CGP54626 and by RNA interference (RNAi)-induced knockdown of the GABAB(1) receptor subtype. Both procedures inhibited the behavioral effects of GHB. GHB pretreatment diminished the behavioral response to subsequent GHB injections; i.e., it triggered GHB tolerance, but did not produce ethanol tolerance. On the other hand, ethanol pretreatment produced both ethanol and GHB tolerance. It appears that in spite of many similarities between ethanol and GHB, the primary sites of their action may differ and that recently cloned putative GHB receptors may participate in actions of GHB that are not mediated by GABAB receptors. These receptors do not have a Drosophila orthologue. Whether Drosophila express a different GHB receptor should be explored.
Application of Variational Methods to Intermediate and High-Energy Scattering

The application of Schwinger's variational principle to scattering by a Yukawa potential is studied. A detailed comparison of the Born approximation, variational, and exact results is given in the energy region from 20 to 150 Mev for a potential strength and range appropriate to the $^{3}S$ neutron-proton interaction. Comparison with the second Born approximation is also made. The utility of the variational principle is discussed and consideration is given to the high-energy limit. It is judged that for most potentials, the variational formulation without elaborate trial functions will be better than the Born approximation.The relation between the variational principles for the total scattering amplitude and for the phase shifts is analyzed. A new formulation intermediate between these two is presented as a compromise between the simplicity of the former and the accuracy of the latter. With the potential studied, use of this formulation leads to considerably better results for the total amplitude than does the original principle.
Dwelling: transforming narratives at historic house museums

Dwellings have been hailed as ‘arguably the single most important artefact for reconstructing past societies’ (Samson 1990, p. 2). Inspired by the persistent centrality of houses to heritage and ou...
Three aspects of aerospace safety

Looks at three aspects of aerospace safety: accidents involving controlled flight into terrain and the developments and training introduced to avoid the risks involved; regulations relating to passenger cabin aisles and access to emergency exits; and human factors in airline maintenance, illustrating how apparently simple maintenance oversights can contribute to major disasters. Discusses what is required to lessen the safety inadequacies in each aspect.
Irrigation with poor quality water

Abstract Supplies of good quality irrigation water are expected to decrease in the future because the development of new water supplies will not keep pace with the increasing water needs of industries and municipalities. Thus, irrigated agriculture faces the challenge of using less water, in many cases of poorer quality, to provide food and fiber for an expanding population. Some of these future water needs can be met by using available water supplies more efficiently, but in many cases it will prove necessary to make increased use of municipal wastewaters and irrigation drainage waters. Aside from increased levels of nitrogen, phosphorus, and potassium, the salinity (total salt content) and sodicity (sodium content) of these waters will be higher than that of the original source water because of the direct addition of salts to the water and the evapoconcentration that occurs as water is used. While the use of these waters may require only minor modifications of existing irrigation and agronomic strategies in most cases, there will be some situations that will require major changes in the crops grown, the method of water application, and the use of soil amendments. Use of poor quality waters requires three changes from standard irrigation practices: (1) selection of appropriately salt-tolerant crops; (2) improvements in water management, and in some cases, the adoption of advanced irrigation technology; and (3) maintenance of soil-physical properties to assure soil tilth and adequate soil permeability to meet crop water and leaching requirements (LR). This paper looks at farmers' experiences, research, and computer modelling in these areas, and concludes with a discussion of examples of farm experiences with waters that caused problems with infiltration rates and soil tilth and the practices used to mitigate these problems.
Do male house mice (Mus musculus) discriminate between females that differ in nutritional status

Most studies of mate choice have focused on female preference for male traits because it is generally assumed that since males provide less parental investment they are not choosy. However, if males suffer missed opportunity costs by mating with lower quality females, selection should favor males with the ability to discriminate among females. We tested the hypothesis that male house mice (Mus musculus) discriminate between females that differ in nutritional status (non-food-deprived versus food-deprived). We recorded the time males spent investigating either type of female and used that to determine preference (spending ≥55% of their total investigation time with one female). We also examined the effects of female nutritional status and female preference status (preferred versus non-preferred) on the reproductive success of males. Males did not display a preference for non-food-deprived females nor did their reproductive success vary with nutritional status or preference status of females. Interestingly, males spent more time investigating females that were closest to the male's own weight. In addition, pairs that were closer in weight were more likely to produce a litter. These results suggest that male house mice are capable of discriminating among females and that such discrimination may influence their reproductive success.
Embedded cavity drag in steady laminar flow

The numerical solution of the laminar boundary-layer flow over an embedded cavity is studied. The purpose of the study is to examine the relevant drag characteristics of laminar cavity flow. The solution field is obtained in terms of velocity and vorticity variables, with the stream function and pressure derivable from the directly computed variables. An analysis and comparison is made among four square cavities, ranging in size from 0.25 to 1.00 boundary-layer thickness deep. The dominant flow features are examined in the vicinity of the cavity by means of the stream function and isovorticity contours. The dominant physics in the overall drag characteristics of the flow are examined by an analysis of the pressure and wall shear-stress distributions in the cavity, and upstream and downstream of the cavity. Pressure forces and frictional forces in, and in the vicinity of, the cavity are determined. Stress relaxation distances, both upstream and downstream of the cavity, are calculated and analyzed. The dynamics of the boundary-layer flow over an embedded cavity are summarized. Finally, the relevance of the present results to the control of flow separation in such flows is discussed.
Electronic effects in the N-nitrosation of N-benzylpivalamides.

A series of N-4-R-benzylpivalamides (R = MeO, Me, H, CF3, and NO2) was nitrosated using a standardized solution of N2O4 in CDCl3 at −40 °C. The reactions, which produced the corresponding N-4-R-ben...
In vitro characterization and in vivo release profile of a poly (d,l-lactide-co-glycolide)-based implant delivery system for the α-MSH analog, melanotan-I

Abstract Melanotan-I (MT-I) is a superpotent tridecapeptide capable of stimulating melanotropic activity. In order to overcome its short half-life in the systemic circulation, the biodegradable poly( d , l -lactide-co-glycolide) (PLGA) copolymer was used to prepare an implant delivery system for MT-I. The implant was prepared by the hot melt-extrusion method. The surface morphology of the PLGA implant was assessed using scanning electron microscopy. The time-dependent changes in the molecular weight distribution of the copolymer and its erosion were monitored in order to help characterize the hydrolytic degradation processes occurring in vivo. The time required to reduce the weight-average molecular weight of PLGA to 50% of its initial value, as determined by size exclusion chromatography, was about 12 days compared to 5 weeks for 50% erosion of the copolymer mass to occur. The release of lactic acid from PLGA was also quantified simultaneously in order to characterize the degradation, and the onset of increased lactic acid release was found to coincide with the onset of the tertiary phase of the MT-I release profile in vivo in guinea pigs. The MT-I released from the depot implanted subcutaneously in guinea pigs exhibited a release profile extending over one month, in agreement with data from the in vitro studies.
Long-term survivors of acute lymphoblastic leukemia--risk of relapse after cessation of therapy.

The results of cessation of therapy (COT) in 64 long-term survivors (disease-free survival of five years or more) of acute lymphoblastic leukemia (ALL) were analyzed to determine the incidence of relapse off therapy. Thirty-seven of the patients had intermittent central nervous system (CNS) prophylaxis. Total follow-up from diagnosis varied from 5.75 to 27.75 years. The median time off therapy was three years (range, 8 months to 26 years). Eighty-six percent (55/64) of the patients continue in their initial remission. Eight patients had relapse, and one patient had a morphologically different leukemia at recurrence. All the relapses occurred between five to eight years from diagnosis and the cumulative rate of relapse for this period was 0.14. There was no significant difference in the rate of relapse for those receiving CNS prophylaxis (0.08) versus those not receiving CNS prophylaxis (0.19). The difference in the relapse rates for boys (0.24) versus girls (0.04) was statistically significant (P=0.04). Isolated testicular relapse (ITR) was not seen in any of the 34 boys. The present study confirms the earlier observations by others that relapse is uncommon in ALL patients remaining in remission longer than seven to eight years. ALL patients treated with intermittent CNS prophylaxis administered throughout the period of maintenance chemotherapy appear to be at no greater risk for relapse off therapy than those treated with high-dose initial cranial irradiation and intrathecal methotrexate. The longer duration of therapy and the use of a repetitive reinduction regimen for maintainance seem to be associated with a decreased risk of ITR after discontinuation of therapy for boys and men. There appears to be a small but definite risk of “second” leukemia in the long-term survivors of leukemia.
Performance Support Bias and the Gender Pay Gap Among Stockbrokers

This article analyzes organizational mechanisms, and their contexts, leading to gender inequality among stockbrokers in two large brokerages. Inequality is the result of gender differences in sales, as both firms use performance-based pay, paying entirely by commissions. This article develops and tests whether performance-support bias, whereby women receive inferior sales support and sales assignments, causes the commissions gap. Newly available data on the brokerages’ internal transfers of accounts among brokers allows measurement of performance-support bias. Gender differences in the quality and quantity of transferred accounts provide a way to measure gender differences in the assignment of sales opportunities and support. Sales generated from internally transferred accounts, controlling for the accounts’ sales histories, provide a “natural experiment” testing for gender differences in sales capacities. The evidence for performance-support bias is (1) women are assigned inferior accounts and (2) women ...
An Analytical Geometric Calibration Method for Circular Cone-Beam Geometry

This work is a continuation of our previous work on geometric calibration in the circular cone-beam geometry. It is well known that seven parameters completely describe such a geometry in either flat-panel X-ray computed tomography or single pinhole SPECT imaging. Previously we developed a graphical procedure to determine the detector in-plane rotation angle independently of the other six parameters. Using the discovered geometrical relationships, in this paper we determine the remaining six parameters using the cone-beam projections of a minimum of three point objects. Our method is analytical. It makes use of the parameters of the fitted ellipse from the calibration data. The parameter estimation is accurate in the noise-free case or when there is moderate projection data truncation or shorter calibration scan range ( ≤ 360°). We perform numerical evaluations to study the robustness of the proposed method under different projection noise levels and using different data acquisition ranges. Using a full 360° scan range, the estimation accuracy and precision of our method are comparable or superior to previous methods. Using a shorter acquisition range, there may be bias in the ellipse parameters obtained by simple algebraic fitting methods. This bias will propagate to the estimated geometric parameters. Such bias can be mostly eliminated by using a more sophisticated fitting algorithm. At the same noise level, the geometric parameter estimation accuracies are comparable, but the estimation precision degrades, as the acquisition range becomes shorter.
Low-density Mg-rich metallic glasses with bending ductility

Amorphous Mg–Cu–Ca(Y) alloys that contain more than 80 at.% magnesium and have a density as low as 1.8 g cm−3 have been prepared by melt spinning. Tension fracture strengths of ∼570 MPa are obtained for Mg85Cu5Ca10 ribbons, resulting in a specific strength of 300 MPa cm3 g−1. Scanning electron microscopy studies reveal dense river patterns on the fracture surface. The high Mg content and the thermal transformation behavior of these amorphous light alloys invite comparison to the Al-based metallic glasses.
Development of a platform to evaluate and limit in-stent restenosis.

The objective of this work was to develop a platform to evaluate and deliver putative therapeutic agents for in-stent restenosis. Arterial stenting is applied in more than 60% of balloon angioplasties for treating cardiovascular disease. However, stented arteries encounter accelerated rates of restenosis. No prior platform has allowed evaluation or local management of in-stent restenosis without perturbing the very system being examined. A stainless steel, balloon-expandable stent was modified to serve as an ablumenal drug delivery platform. Several combinations of bioerodible polymer microspheres and gels were evaluated for channel retention under in vitro flow and in vivo conditions. A stent-anchored hybrid system prevented material embolization under all conditions. Unlike prior platforms, these stents do not alter local inflammation or in-stent plaque formation relative to conventional Palmaz-Schatz stents after in vivo deployment. The system also proved sensitive enough to detect plaque reduction wit...
On a result of Riemenschneider

O. Riemenschneider has recently exhibited a class of normal 2-dimensional analytic singularities for which some deformations of the minimal resolution cannot be blown down to deformations of the singularity. In this note we identify the obstructions to doing so, using algebraic techniques introduced by Schlessinger and the author.
The Emerging Political Consciousness of the Aged: A Generational Interpretation1

Generational analyses have tended to focus on youth movements and ideologies, in keeping with the Mannheim emphasis on new generations. Age-group political consciousness among the elderly may be an emergent feature of the current political scene; thus, it is useful to examine the generational aspects of a political movement among the elderly as well. This paper presents a model of the factors contributing to the development of socio-political movements. It appears that an aged social movement will not develop unless age-group political consciousness among the elderly is manifest. The prospects of the emergence of that political consciousness and a social movement of the aged are discussed, with attention to precursors of these political expressions in the current generation of older people.
TH‐A‐BRA‐10: The Role of Treatment Plan Adaptation during the Course of Proton Radiotherapy for Patients with Head and Neck Cancer

Purpose: To evaluate the advantages of adaptive replanning associated with protonradiotherapytreatment of patients with head and neck cancer.Methods: Six patients with tumors in the base of skull were treated with protonradiotherapy. Two CTs of the same patient, planning and repeat, were first registered rigidly in relation to bony structures of the skull to remove the setup error. A deformable B‐spline based registration was performed between the two CTs. The resulting deformation field was used to automatically transfer structure contours from the planning‐CT to the repeat‐CT. The original treatment plan was applied to the repeat‐CT and the dose distribution was recalculated. The differences between new and original dose distributions were evaluated by comparing isodose lines and by performing distance‐to‐agreement dose distribution analysis. The automatically transferred contours were used to compute dose‐volume histograms for the repeat‐CT and these were compared to the original DVHs. Results: Autotransferred contours were investigated by a physician and found satisfactory for the most critical structures. The targets were delineated manually. Anatomic changes caused by patient response to the treatment were primarily due to tumor shrinkage in the nasal cavity and in the paranasal sinuses. As a result the areas around target became highly heterogeneous with respect to density distribution. In 2 cases these heterogeneities resulted in hot spots within the tumor larger than 1 cm3 with a dose increase of 6%. In one case a cold spot with a dose decrease of 7% was observed. Conclusions: Evaluation of six cases shows no significant dosimetric changes that can favor adaptive replanning at the mid‐course of protonradiotherapy of head and neck cancer. Analysis of a larger patient set is needed to establish robust patterns of tissue deformation and dosimetric changes, with a focus on variations of the dose distribution in the presence of heterogeneities.
Baseline laryngeal effects among individuals with dust mite allergy.

Objective To examine baseline effects of perennial allergy on laryngeal appearance, laryngeal function, and perceived vocal handicap among individuals without current allergy or voice symptoms. Data Sources This pilot study included 47 adults: 21 with positive and 26 with negative skin test responses for the dust mite, Dermatophagoides pteronyssinus . Methods Subjects were tested for sensitivity to dust mite antigen by prick testing. Laryngeal appearance and function were studied with laryngovideostroboscopy, acoustic and speech aerodynamic analysis, and voice sampling. These parameters were blindly analyzed by three trained examiners. Subjects also completed the Voice Handicap Index (VHI) as a measure of vocal handicap. Results Subjects allergic to dust mites perceived significantly greater vocal handicap on the VHI than did nonallergic subjects. No significant differences were noted between groups in laryngeal appearance or function. Conclusion These pilot data suggest that, at baseline, allergic individuals perceive greater vocal handicap than their nonallergic counterparts ( P = 0.04), even in the absence of current allergy symptoms or observable physical or functional abnormalities. These preliminary observations can serve as an impetus for further research into this important area, including the potential interrelationship between acid reflux disease and allergic laryngeal inflammation.
Culture and Relativism

The meanings and implications of cultural relativism have been debated for decades. Reprising this debate, Roger Sandall offers a pointed critique of the anthropological concept of culture and identifies relativism as the internal and corrosive enemy of the open society. I challenge his reading of our predicament. Considering the work of Franz Boas and his debts to the philosopher Johann Gottfried Herder, I distance the social science concept of culture from positions—the rejection of standards of truth, beauty, and morality; the belief that cultural value systems and practices are all equally true (or untrue); the valorization of primitivism—that are not intrinsic to it. Next, I consider the use of culture in the “philosophy of primitivism” and its meanings in multiculturalism and identity politics. I argue that many ostensibly relativist claims are used to serve non-relativist agendas, or hide universalistic claims in unstated but essential premises and background assumptions. Rather than a world dominated by relativism, where cultural differences are held to be inviolable and cross-cultural judgments have been rendered impossible, I see something like the reverse. Our problem is not that we overvalue cultural differences but that we underestimate them. Even in our multiculturalism, we imagine a sameness of outlook and aspiration, an unwitting projection of ourselves in the end.
Powers of the Euler Class

Abstract Let G τ be the topological group of orientation preserving homeomorphisms of the circle S 1 . The Classical Euler Class and its powers generate the cohomology of the classifying space B G τ . In the transition from continuous G τ to discrete G δ the behavior of the powers of the Euler Class is altered significantly. There are subgroups K of G δ for which the powers of the Discrete Euler Class E n ∈ H 2 n ( B G δ , Z ) are non-vanishing only up to a certain dimension. In this work we determine the threshold dimension for certain groups of homeomorphisms of the circle. Our results are applied to the Based Mapping Class Groups, M g , ⁎ , and we show: E n ( M g , ⁎ ) ≠ 0 , n g , but E n ( M g , ⁎ ) = 0 , n > g . At the threshold dimension n = g the Discrete Euler Class has torsion of order 2 g ( 2 g + 1 ) .
Estimates for the wave kernel near focal points on compact manifolds

This article deals with analogue statements of the so-called basic Strichartz inequality for certain values of the time variable t on a smooth compact manifold; that is we prove Lq′ → Lq bounds for the modified half-wave operator eitP P− (n+1)(1/2− 1/q) where\(P = \sqrt { - \Delta + c^2 } \) for a set of times t which depends on the global behavior of the geodesic flow. Then we give estimates for the blow-up of the bounds as approaching the limit points of this set. In doing this we use facts from differential geometry and the calculus of variations.
On the oblique impact of a rigid sphere against a rigid-plastic solid

Abstract Previous workers have sought to explain the variation in crater volume observed when hardened steel spheres impact at different angles against mild steel plates by numerically modelling a rigid sphere striking an ideal rigid-plastic half-space. The present note shows that the discrepancy between experiment and their throretical prediction from this model can be significantly reduced by incorporating a more accurate calculation of the area of contact into the analysis.
Losses in slab photonic crystals induced by fabrication tolerances

We investigate the effect of fabrication tolerances on the propagation losses of light guided in photonic crystal waveguides. We focus on slab photonic crystals defined as a regular array of holes in high index material such as silicon. The deviation of photonic crystal lattice parameters, such as the hole diameter, from the ideal results in the shift of the guided mode in the photonic band gap. This shift occurs randomly along a photonic waveguide as the electromagnetic wave propagates in it. Because the range of frequencies supported in a photonic crystal waveguide is typically very narrow, even a small deviation of the lattice parameters may result in a sufficiently large shift for the wave to fall out of the guided range and become lossy. Indeed, we demonstrate that a deviation in hole size as small as a few percent can result in a guided mode becoming radiative. Consequently, a wave propagating in a real photonic crystal waveguide undergoes multiple transitions between guided and radiative modes, depending on the local variations of the photonic crystal parameters. This results in lossy propagation of the wave. We present simulations of the light propagation in a photonic crystal waveguide incorporating real-life fabrication tolerances.
T-Lymphocyte Subsets in Liver Tissues of Patients with Primary Biliary Cirrhosis (PBC), Patients with Primary Sclerosing Cholangitis (PSC), and Normal Controls

T lymphocytes infiltrating hepatic tissues were typed and enumerated in liver biopsies of patients with primary biliary cirrhosis (PBC), patients with primary sclerosing cholangitis (PSC), and normal controls using monoclonal antibodies and the avidin-biotin-immunoperoxidase technique. The peripheral blood mononuclear cells were studied also by flow cytometry. In PBC, T lymphocytes were decreased (P<0.001) in the blood [absolute number was 426±200 (SE) vs 1351±416 in 15 controls], as was the helper/suppressor (T4/T8) ratio (1.0±0.1 vs normal 2.3±0.3). T lymphocytes were the most numerous mononuclear cells infiltrating portal areas of PBC livers: 749±93/5 high-power fields (HPF) in PBC vs 98±15/5 HPF (P<0.01) in controls. The T4/T8 ratios varied from 0.9 to 2.3 (mean, 1.8±0.1) in the portal triads (normal mean, 1.6±0.1), with the T4+ cells accounting for more than 75% of infiltrating T cells. In contrast, the mean T4/T8 ratio in portal triads of PSC was reduced (1.0±0.3) due to a significant increase (P<0.001) in the number of T8+ cells. The T cells around and in the walls of bile ducts in PBC were mostly T8+, and the T4/T8 ratio was 0.8±0.2. No T8+ cells were seen in this location in PSC and normal livers. Few mononuclear cells were present in hepatic lobules. Subtyping of T lymphocytes in liver tissues of patients with PBC and PSC may be helpful in the differential pathologic diagnosis. In patients with advanced PBC, a decrease in T4+ cells in the blood appeared to be accompanied by their accumulation in the portal triads. In contrast, T8+ cells accumulated preferentially around bile ducts.
In vitro studies of insect haemocytes

Abstract Several criteria for the objective assessment of death of milkweek bug haemocytes in culture were examined and the in vitro pattern of DNA synthesis by the haemocytes was determined. The simplest criterion of death was the presence of ‘chromatin droplets’. The presence of these droplets correlated quite well with the inability of the haemocytes to exclude the vital dye, trypan blue. The in vitro uptake of tritiated thymidine by the haemocytes was greatest on days 1 to 4, somewhat less on day 5, and very low on the day of ecdysis and days 6, 7, and 8 of the fifth instar. Comparisons of this pattern are made with several other studies on the fifth instar milkweed bug.
Analysis of the excess specific heat of copper from 300 to 1200°K

Abstract Recent measurements of the specific heat of copper from 300 to 1200°K have been analyzed in order to estimate contributions from the formation of equilibrium lattice defects and anharmonic effects. This was accomplished by converting the experimental specific heat at constant pressure to that at constant volume using experimental data of specific volume, volume expansivity and isothermal compressibility reported in the literature. The excess specific heat was obtained by subtracting from the specific heat at constant volume a theoretical specific heat based on the Debye specific heat, using a single Debye temperature, corrected for electronic contributions. The excess specific heat increases more than linearly with temperature, becoming significant around 600°K and amounting to about 7 per cent of the specific heat at 1200°K. An analysis of the excess specific heat indicates that the formation of equilibrium monovacancies makes a contribution beginning around 800°K, accounting for about one third of the excess specific heat at 1200°K. It is concluded that the remaining excess specific heat is caused by anharmonic effects in the lattice.
Fire, nitrogen, and defensive plasticity in Nicotiana attenuata.

Nicotiana attenuata is a post-fire annual that utilizes jasmonate-inducible nicotine production as an inducible chemical defense which, in turn, can utilize 6% of a plant' s nitrogen budget and be costly to seed production. We characterize the nitrogen pools of burned soils in the plant' s native environment (pinyon-juniper woodlands) and examine how variation in nitrogen source and supply rate influence the patterns of allocation to growth and inducible and constitutive nicotine production. Available soil nitrogen increases dramatically (40-fold) immediately after a fire and consists principally of ammonia which is subsequently oxidized to nitrate during post-fire succession. We simulate these changes in nitrogen availability in hydroponic culture and use allometric techniques to characterize changes in allocation. In two experiments, we alter (1) nitrate supply rates 8-fold and (2) the ratio of ammonia:nitrate under consistent nitrogen supply rates. In both experiments, we increase the allocation to nicotine by treating roots with methyl jasmonate (MJ), the methyl ester of the plant' s internal wound signal, jasmonic acid, which increases nicotine production in the roots after shoot herbivory. MJ treatments decrease whole plant (WP) growth, increase root:shoot ratio, and increase WP nicotine pools in all nitrogen environments. Overall, source and supply rate of nitrogen have no effect on either the constitutive or induced allometric relationships of nicotine accumulation and growth. This remarkable homeostasis in allocation patterns contradicts a key prediction of carbon nutrient (C/N) theory. With 15N-pulse-chase techniques, we demonstrate that plants preferentially utilize ammonia for nicotine production over nitrate when both nitrogen sources are available. This preferential use of ammonia may allow N. attenuata to reduce the biochemical costs of producing nicotine in the post-fire environment.
Biodegradability of chitin- and chitosan-containing films in soil environment

The biodegradation of polyethylene-chitin (PE-chitin) and polyethylene-chitosan (PE-chitosan) films, containing 10% by weight chitin or chitosan, by pure microbial cultures and in a soil environment was studied. Three soil-inhabited organsims,Serratia marcescens, Pseudomonas aeruginosa, andBeauveria bassiana were able to utilize chitin and chitosan in prepared PE-chitin and PE-chitosan films after eight weeks of incubation at 25°C in a basal medium containing no source of carbon or nitrogen. In a soil environment, the biodegradation of those films was studied and compared with a commercial biodegradable film containing 6% by the weight of corn starch. In soil placed in the lab, 73.4% of the chitosan and 84.7% of the chitin in the films were degraded, while 46.5% of the starch in the commercial film was degraded after six months of incubation. In an open field, 100% of the chitin and 100% of the chitosan in the films were degraded, but only 85% of the starch in the commercial film was degraded after six months of incubation. The weight of controls, (polyethylene films), remained mainly stable during the incubation period. Both PE-chitin and PE-chitosan films degraded at a higher rate than the commercial starch-based film in a soil environment indicating the potential use of chitin-based films for the manufacturing of biodegradable packaging materials.
DNA synthesis during lens regeneration in larval Xenopus laevis.

Larvae of Xenopus laevis at stages 50–53 were lentectomized and then injected with tritiated thymidine at various times after lentectomy. In Series I, the animals were injected 1, 2, 3, 4, 6, 8, 10, 12, 15, or 17 days after lens removal and fixed three hours after injection. Autoradiographs of serial cross sections through the eyes were prepared. Increased incorporation of thymidine in the cells of the regenerating lens was first observed two days (stage 2) after lentectomy. All of the cells of the lens vesicle incorporated H3-thymidine until stage 4 at which time the cells in the inner wall of the vesicle began to differentiate into lens fibers. Labelling then became restricted to the peripheral cells (prospective lens epithelium and prospective lens fibers). At stage 5 of regeneration, only cells of the lens epithelium incorporated H3-thymidine. In Series II, animals injected three or four days after lentectomy were fixed daily from one to seven days after injection. Many stage 3 and stage 4 regenerates were recovered with label throughout and stage 5 regenerates were found, seven days after injection, with label over the lens fibers as well as over the lens epithelium.
Supercomputer-based spherical scene projector

A multi-technology high performance computing system based on the Open Parallel Architecture Design Specification (OPADS) platform is being evaluated for use as a graphics engine for spherical scene projection. This system is designed to make available the massive quantities of real-time processing power needed to support complete real time scene generation and projection of complex dynamical maneuvers for applications such as scientific visualization and three dimensional database creation and interaction. A comparison is also provided between head mounted projection systems and walk-in spherical scene projection systems.