cssi/SciSciGPT-SciSciNet huggingface dataset:
Uranium solution-mineral equilibria at low temperatures with applications to sedimentary ore deposits

Abstract Gibbs free energies, enthalpies and entropies of 42 dissolved uranium species and 30 uranium-bearing solid phases have been critically evaluated from the literature and estimated when necessary for 25°C. Application of the data shows that the uranium in natural waters is usually complexed. At typical concentrations of chloride, fluoride, phosphate and sulfate, uranous (U4+) fluoride complexes are important in anoxic waters below pH 3–4. An intermediate Ehs (between about +0.2 and −0.1 V) and pH values 1–7, UO2+ ion may predominate. In oxidized waters, uranyl (U22+) fluoride complexes and uranyl ion predominate below pH 5; from about pH 4 to 7.5, UO2(HPO4)22− is the principal species; while at higher pHs, UO2CO30 and the di- and tri-carbonate complexes predominate. Uraninite [UO2-UO2.25], α-U3O8 and schoepite are the stable uranium oxides and hydroxides in water at 25°C. Coffinite, USiO4 (c), is probably stable relative to UO2(c) when dissolved silica exceeds about 60 ppm (as SiO2). At low Ehs and pH 4–6, the solubilities of stoichiometric crystalline uraninite and coffinite are below roughly 10−4 ppb. But at intermediate Ehs and neutral to alkaline pHs in the presence of phosphate or carbonate, the formation of uranyl phosphate or carbonate complexes can increase the solubilities of these minerals by several orders of magnitude. The uranyl minerals carnotite, tyuyamunite, autunite, potassium autunite and uranophane are least soluble at pHs in the range 5–8.5 and, in the case of carnotite and tyuyamunite, have solubilities as low as 0.2 and 1 ppb uranium, respectively. The autunites and uranophane are usually several orders of magnitude more soluble than this, consistent with their natural occurrences. Sorption of uranyl on to natural materials is maximal in the same pH range of 5–8.5.
MAPPING EPITOPE SPECIFICITIES OF MONOCLONAL ANTIBODIES TO THYROID PEROXIDASE USING RECOMBINANT ANTIGEN PREPARATIONS

Five separate monoclonal antibodies (MoAbs) to human thyroid peroxidase (hTPO) were raised by immunising Balb/c mice with hTPO purified from detergent solubilised thyroid microsomes by high performance liquid chromatography (HPLC). The epitope specificities of these MoAbs were determined by assessing their ability to bind to purified recombinant fusion protein fragments of human TPO (TPO(r)) generated in E. coli. A total of seven small overlapping fragments (averaging 104 amino acid residues) of hTPO, encompassing over 90% of the extracellular region of the molecule, were generated as glutathione S-transferase (GST) fusion proteins. The sequential epitopes on TPO(r) recognised by these MoAbs were analysed by both immunoblotting and enzyme linked immunosorbent assay (ELISA). Two different MoAbs (A4 and A5) recognised sequential epitopes within the TPO(r) preparation termed R1a + b (residues 1-160) and more specifically, in the case of MoAb A4, within the subfragment R1b (residues 70-160). The inability of the other MoAbs (A1-A3) to recognise recombinant fragments, suggests they either recognise conformational determinants on the TPO molecule or epitopes that are present on the small regions of the TPO molecule which have not been expressed as recombinant proteins.
Hepatic redox homeostasis following acute adriamycin intoxication in rats

Adriamycin toxicity is postulated to result from cytochrome P-450 reductase-catalyzed univalent reduction of the quinone to the semiquinone free radical intermediate. Oxygen radicals generated during the nonenzymatic reoxidation of the semiquinone have been implicated in the deleterious modification of a variety of tissue macromolecules. Detoxification of reactive products, such as hydroperoxides, is proposed to involve the consumption of vital cellular reducing equivalents which may, in itself, represent the primary causative event in toxic tissue damage. The present investigation demonstrates that hepatic tissue has sufficient glutathione (GSH) reductase to prevent a decrease in GSH following acute adriamycin administration to rats. Similarly, except for a transient decrease in NAD, adriamycin intoxication caused minimal changes in the hepatic pyridine nucleotide content in vivo. It is concluded that species- and tissue-specific differences in the distribution of antioxidant defense mechanisms may be primary determinants of the relative insensitivity of liver and, in contrast, the rather selective cardiomyopathy resulting from adriamycin administration in vivo.
Melatonin suppresses macrophage cyclooxygenase-2 and inducible nitric oxide synthase expression by inhibiting p52 acetylation and binding

Melatonin has been shown to be produced by nonpineal cells and possess anti-inflammatory actions in animal models. In the present study, we tested the hypothesis that melatonin suppresses the expression of proinflammatory genes such as cyclooxygenase-2 (COX2) and inducible nitric oxide synthase (INOS) by a common transcriptional mechanism. Melatonin but not tryptophan or serotonin inhibited lipopolysaccharide (LPS)–induced COX-2 and iNOS protein levels and promoter activities in RAW 264.7 cells in a time- and concentration-dependent manner. LPS or LPS plus interferon-γ (IFNγ) increased binding of all 5 isoforms of NF-κB to COX-2 and iNOS promoters. Melatonin selectively inhibited p52 binding without affecting p100 expression, p52 generation from p100, or p52 nuclear translocation. p52 acetylation was enhanced by LPS, which was abrogated by melatonin. Melatonin inhibited p300 histone acetyltransferase (HAT) activity and abrogated p300-augmented COX-2 and iNOS expression. HAT inhibitors suppressed LPS-induced p52 binding and acetylation to an extent similar to melatonin, and melatonin did not potentiate the effect of HAT inhibitors. These results suggest that melatonin inhibits COX-2 and iNOS transcriptional activation by inhibiting p300 HAT activity, thereby suppressing p52 acetylation, binding, and transactivation.
Striking it Niche–Extending the Newspaper Brand by Capitalizing in New Media Niche Markets: Suggested Model for Achieving Consumer Brand Loyalty

ABSTRACT This study attempts to develop a framework, the “Communicator-Based Hierarchy-of-Effects Model,” to provide a quantitative method for measuring the steps communicators need to accomplish to achieve consumer brand loyalty. This exploratory study presents the results of a nationwide survey of daily newspaper website managers and their marketing and management of newspaper niche sites. This baseline study's data support the inclusion of the first five steps in the model. The study found that the respondents are primarily concerned with short-term goals, such as generating revenue and increasing readership, but not long-term goals, such as brand loyalty. In addition, the study demonstrates that the circulation of the printed newspaper significantly impacts many aspects of the online newspaper business.
Mapping the structure of folding cores in TIM barrel proteins by hydrogen exchange mass spectrometry: the roles of motif and sequence for the indole-3-glycerol phosphate synthase from Sulfolobus solfataricus.

To test the roles of motif and amino acid sequence in the folding mechanisms of TIM barrel proteins, hydrogen-deuterium exchange was used to explore the structure of the stable folding intermediate for the of indole-3-glycerol phosphate synthase from S. solfataricus (sIGPS). Previous circular dichroism and fluorescence studies of the urea denaturation of sIGPS revealed the presence of an intermediate that is highly populated at ∼4.5 M urea and contains ∼50% of the secondary structure of the native state. Kinetic studies showed that this apparent equilibrium intermediate is actually comprised of two thermodynamically-distinct species, Ia and Ib. To probe the location of the secondary structure in this pair of stable on-pathway intermediates, the equilibrium unfolding process of sIGPS was monitored by hydrogen-deuterium (HD) exchange mass spectrometry. The intact protein and pepsin-digested fragments were studied at various urea concentrations by electrospray and MALDI-TOF mass spectrometry, respectively, after deuterium labeling and quenching in acid. Intact sIGPS strongly protects 54 amide hydrogens from HD exchange in the intermediate states, demonstrating the presence of stable folded cores. When the protection patterns and the exchange mechanisms for the peptides are considered with the proposed folding mechanism, the results can be interpreted to define the structural boundaries of Ia and Ib. Comparison of these results with previous HD exchange studies on another TIM barrel protein of low sequence identify, the alpha subunit of tryptophan synthase (αTS), indicates that the thermodynamic states corresponding to the folding intermediates are better conserved than their structures. Although the TIM barrel motif appears to define the basic features of the folding free energy surface, the structures of the partially-folded states that appear during the folding reaction depend on the amino acid sequence. Markedly, the good correlation between the HD exchange patterns of sIGPS and αTS with the locations of hydrophobic clusters defined by isoleucines, leucines, and valines suggests that branch aliphatic side chains play a critical role in defining the structures of the equilibrium intermediates.
Parallel regulation of membrane trafficking and dominant-negative effects by misrouted gonadotropin-releasing hormone receptor mutants

Gonadotropin-releasing hormone (GnRH) receptor mutants from patients with hypogonadotropic hypogonadism are frequently misrouted proteins that exert a dominant-negative (DN) effect on human (h) wild-type (WT) receptor, due to oligomerization and retention in the endoplasmic reticulum. Pharmacologic chaperones restore correct folding, rescuing mutants and WT receptor from this oligomer. Rat WT retains the ability to oligomerize (since human and mouse mutants exert a DN effect on rat (r) WT sequence) but, unlike human or mouse, escapes the DN effect of GnRH receptor (Gn-RHR) mutants because rGnRHR mutants route to the plasma membrane with higher efficiency than mouse or human mutants. These distinct behaviors of mouse and rat GnRHRs (distinguished by only four semi- or non-conservative amino acid differences) led us to assess the role of each amino acid. The difference in both routing and the DN effect appears mediated primarily by Ser216 in the rGnRHR. The homologous amino acid in the hGn-RHR is also Ser and is compensated for by the primate-unique insertion of Lys191 that, alone, dramatically decreases routing of the receptor. These studies establish the relation between the DN effect and altered receptor trafficking and explain why hGnRHR is more susceptible to defective trafficking by disease-related point mutations than rodent counterparts.
Deflection of laser-excited atoms by an electric field

An experiment is analyzed in which an atomic beam in a collinear, counterstreaming laser beam is deflected by an inhomogeneous dc electric field. The force acting on the translational motion of the atom is found. This describes a modification of the deflection due to the laser. The atom tends to decouple itself from the laser, but a method is suggested for a continuous recoupling. This can result in a large difference in the scattering between atoms coupled to the laser and atoms uncoupled. The applicability to isotope separation is pointed out.
Alzheimer's Disease: Morbid Risk Among First-Degree Relatives Approximates 50% by 90 Years of Age

• The morbid risk of Alzheimer's disease was studied in first-degree relatives of 50 patients who met contemporary clinical research diagnostic criteria and 45 matched controls. Relatives of patients showed a 46% cumulative incidence of probable Alzheimer's disease by 86 years of age. The risk, which was four times the control value, is consistent with other recent reports using similar, modern methods. Although not conclusive, the data suggest the operation of a relatively common, dominant autosomal gene for Alzheimer's disease, the expression of which is delayed until late old age but is largely complete by 90 years of age.
Molecular orbital calculations of electric field gradients at halogen nuclei in solid chlorine and bromine

Abstract Using the MO LCAO method in CNDO and INDO approximations, calculations of the electronic structure of polyatomic clusters in solid Cl 2 and Br 2 have been performed. The energies of the molecular orbitals of the clusters are compared with the available experimental data and theoretical results. The effect of d -orbitals on intermolecular bonding is examined in the case of solid chlorine, and the parameters of the electric field gradient tensor at halogen nuclei are evaluated in both cases of solid chlorine and bromine. The calculated quadrupole coupling constants are in satisfactory agreement with the observed values, but the electric field gradient asymmetry parameter is found to be very small in every case, in contradiction of the experimental results. Finally, the possible reasons for such a discrepancy are discussed.
Neutrophil activation monitored by flow cytometry: stimulation by phorbol diester is an all-or-none event

The population dynamics of single-cell stimulation was analyzed by monitoring autofluorescence by flow cytometry. Stimulation of the respiratory burst in human neutrophils by 12-O-tetradecanoyl phorbol-13-acetate (TPA) caused a decline in highly fluorescent cells (characteristic of resting neutrophils) and a corresponding increase in the number of weakly fluorescent cells (characteristic of activated neutrophils). Increasing concentrations of TPA caused increasing numbers of cells to shift from the highly fluorescent population to the weakly fluorescent population without the appearance of intermediate populations. Thus the neutrophil respiratory burst, a component of neutrophil cytotoxic response, is triggered in an all-or none fashion.
Electroencephalographic studies of conditional cerebral response in epileptic subjects.

Abstract Classical conditioning techniques were employed to investigate the effect of conditioned “excitation” and “inhibition” upon the occurrence of epileptiform activity in the EEG of patients with convulsive disorders. Four patients with high voltage spike-wave response regularly elicited by photic stimulation were subjected to repeated pairing of the S-W inducing light with a neutral tone. Despite more than 500 paired presentations of the two signals, and persistence of the S-W response to the light, no evidence of conditioning the S-W to follow the tone was obtained. However, presentation of tone signals unreinforced by light (differential stimulus and extinction of CS) after numerous paired sound-light trials resulted in a highly significant increase in occurrence of S-W to the unreinforced stimuli. Nineteen epileptic patients with sustained photic driving responses to specific flash frequencies were subjected to a conditioning procedure in which the attempt was made to condition the occipital driving response to follow a previously neutral tone. Little evidence of conditioned driving was obtained. However, again the unreinforced signals (differential and extinction stimuli) provoked a significant increase in incidence of sharp, paroxysmal, slow and epileptiform changes in the EEG. Retardation of the light stimulus (Trace reflex) also enhanced the propensity to pathological EEG discharge in both groups. These EEG abnormalities were similar to the focal or diffuse pathological findings noted from these patients during previous EEG studies. The exaggeration of paroxysmal activity by unreinforced stimuli is considered in relation to theories of “conditioned expectation” and Pavlovian “conditional inhibition”. Slowing of scalp frequencies during non-reinforcement may be a crucial factor contributing to the potentiation of abnormal EEG patterns.
Optimum Tariffs and Retaliation Revisited: How Country Size Matters

In his seminal work on tariff retaliation, Johnson (Review of Economic Studies, 21, 1953-1954) showed that a country will "win" a bilateral "tariff war" if its relative monopoly/monopsony power in world trade is sufficiently large. However, it is unclear from Johnson's analysis and from subsequent research on the subject how this power is determined in general economic environments. An important goal of this paper is to address this issue. With the help of a neoclassical trade model in which country size is at centre stage, it is shown that a sufficient condition for a country to prefer a non-cooperative Nash tariff equilibrium (retaliation) over free trade is that its relative size be sufficiently large. The paper also refines the structure of the general trade model and generates additional characterization results on the importance of country size for best-response tariff functions, retaliatory tariffs, and welfare.
Dynamic deformation and fracture behavior of novel damage tolerant discontinuously reinforced aluminum composites

Abstract Extrinsically toughened discontinuously reinforced aluminum composites are processed with the objective of enhancing damage tolerance of conventional particle reinforced aluminum composites. The approach consists of producing a composite microstructure in which discrete ductile phases have been incorporated into the particle reinforced metal matrix via traditional powder processing routes. The present study focuses on investigating the effects of volume fraction and flow strength of the ductile phase reinforcements in determining dynamic deformation and fracture characteristics of these extrinsically toughened composites. The dynamic compression behavior of the composites is examined by employing the split Hopkinson pressure bar. The measured dynamic stress–strain response of the composites is correlated with the macro- and micro-damage mechanisms inferred from post examination of the impacted specimens. The dynamic fracture characteristics of the composites are obtained by impact loading pre-cracked three point bend specimens in a modified Hopkinson bar apparatus. The measured load-point force versus load-point displacement curves are used to, (a) estimate the energy required for dynamic crack initiation, and (b) understand the interaction of the dynamically propagating crack tip with the ductile phase reinforcements. The results indicate that the extrinsically toughened DRA composites absorb significantly greater energy during the crack propagation as compared to the conventional DRA composites. Also, the level of extrinsic toughening introduced in the composites is affected by the location, volume fraction and mechanical properties of the ductile phase reinforcements. Amongst the relatively larger volume fraction ductile-phase reinforced composites, the ductile phase reinforcements comprising low flow strength commercial purity aluminum fail primarily in a ductile manner, whereas the ductile phase reinforcements comprising high strength Al alloy fail in a cleavage manner by inter-granular fracture.
Circadian rhythm of oxygen consumption in the marsh periwinkle, Littorina irrorata (Say, 1822)

Abstract 1. 1. A daily rhythm of oxygen consumption was demonstrated in the salt marsh periwinkle. Littorina irrorata . Snails maintained on a 12L:12D photoperiod had highly significant increased respiration rates during the dark phase for 6 days. 2. 2. The respiration rhythm was found to persist in constant darkness for at least 50 hr but not for 6 days. 3. 3. The oxygen consumption rhythm was entrained to an inverted photoperiod of 12D:12L after 64 hr exposure to the new photoperiod. Higher respiration rates still occurred during the dark phase. 4. 4. A decrease of both magnitude and amplitude of the respiration rhythm occurred with time.
Numerical modeling of mixed sediment resuspension, transport, and deposition during the March 1998 episodic events in southern Lake Michigan

A two-dimensional sediment transport model capable of simulating sediment resuspension of mixed (cohesive plus noncohesive) sediment is developed and applied to quantitatively simulate the March 1998 resuspension events in southern Lake Michigan. Some characteristics of the model are the capability to incorporate several floc size classes, a physically based settling velocity formula, bed armoring, and sediment availability limitation. Important resuspension parameters were estimated from field and laboratory measurement data. The model reproduced the resuspension plume (observed by the SeaWIFS satellite and field instruments) and recently measured sedimentation rate distribution (using radiotracer techniques) fairly well. Model results were verified with field measurements of suspended sediment concentration and settling flux (by ADCPs and sediment traps). Both wave conditions and sediment bed properties (critical shear stress, fine sediment fraction, and limited sediment availability or source) are the critical factors that determine the concentration distribution and width of the resuspension plume. The modeled sedimentation pattern shows preferential accumulation of sediment on the eastern side of the lake, which agrees with the observed sedimentation pattern despite a predominance of particle sources from the western shoreline. The main physical mechanisms determining the sedimentation pattern are (1) the two counter-rotating circulation gyres producing offshore mass transport alongmore » the southeastern coast during northerly wind and (2) the settling velocity of sediment flocs which controls the deposition location.« less
Asymptomatic myocardial ischemia during percutaneous transluminal coronary angioplasty and importance of prior Q-wave infarction and diabetes mellitus.

Abstract Eighty-eight patients undergoing percutaneous transluminal coronary angioplasty (PTCA) of 100 stenoses were studied for the presence of factors deemed significant in the etiology of silent myocardial ischemia. Thirty-two patients were asymptomatic during balloon dilations of 36 arteries, and 56 patients had angina during PTCA of 64 arteries. There were no differences in age, sex, prior anginal history, antianginal regimen, extent of coronary artery disease and number or duration of inflations between the 2 study groups. Previous infarction (33 vs 12%, p This study shows that asymptomatic ischemia occurs frequently during PTCA in patients with symptomatic coronary disease. Prior Q-wave infarction and diabetes mellitus are important, independent factors associated with painless ischemia. It is suggested that infarction produces a localized dysfunction of afferent cardiac pain fibers, whereas diabetes can cause a global cardiac sensory neuropathy.
Plankton community responses in earthen channel catfish nursery ponds under various fertilization regimes

We evaluated fertilizer effects on phytoplankton and zooplankton concentrations in channel catfish Ictalurus punctatus nursery ponds. In 2001, three ponds were not fertilized and three ponds were fertilized with inorganic (8.4 kg/ha N, 2.0 kg/ha P followed by twice a week applications at half the initial rate) and organic fertilizer (224 kg/ha cottonseed meal followed by once a week applications of 28 kg/ha) for 4 weeks. Total P and soluble reactive P (SRP) were significantly higher in fertilized ponds (P 10 years). Within each age group, treatments of no fertilizer (controls), organic fertilizer only, inorganic fertilizer only, or both organic and inorganic fertilizers were used for 3 weeks. In 2002, the same P but higher N rates were used (20.2 kg/ha N followed by twice a week at half rate). Several differences occurred among treatments (P<0.05). Both total P and total N were significantly higher in ponds fertilized with inorganic fertilizer and both inorganic and organic fertilizers than in control ponds and organically fertilized ponds. Also, total P, total N, SRP, and nitrite were all significantly higher in old ponds than in new ponds. All phytopigment concentrations were also higher in old ponds than in new ponds. Chlorophyll a (total algal biomass), lutein (green algal biomass), and fucoxanthin (diatom biomass) were significantly higher in ponds fertilized with inorganic fertilizer or both inorganic and organic fertilizers than in control or organically fertilized ponds. Old ponds contained significantly more rotifers, copepod adults, and ostracods than new ponds. Rotifer and ostracod concentrations were not different among fertilizer treatments. Copepods adults and nauplii were significantly increased in ponds fertilized with both organic and inorganic fertilizers than in organically fertilized ponds. Cladocerans were significantly higher in inorganically fertilized ponds than in all others. Results indicated little benefit of organic fertilizer addition at the rates used. Also, ponds appear to be more N limited than P limited. Old ponds are more fertile than new ponds. Applying only inorganic fertilizer at an initial rate of ∼20 kg/ha N and 2 kg/ha P, followed by subsequent applications of half the initial rate for 3–4 weeks increased zooplankton concentrations desirable for fry with larger mouth gapes.
A versatile wavelength-dependent spectrophotometer for efficiency measurements of CCD and cryogenic gratings

A user-friendly and automatic illuminator with adjustable wavelength and optical power has been developed to obtain precision quantum efficiency (QE) curves of astronomical CCD as well as optical transmission measurements for cryogenic holographic gratings and other optical components. Integrating commercial components with custom mechanical parts and control software, this equipment is able to illuminate a target with light of controlled intensity and wavelength. This facility is primarily intended for testing of Volume Phase Holographic (VPH) gratings at low temperature as well as obtaining CCD quantum efficiencies. A Labview control application runs on a desktop computer allowing full automation of the spectrophotometer. The apparatus includes a Quartz-Tungsten light source, neutral density filters, a monochromator, visible and near-infrared power meters, as well as collimating and focusing optics. Rotation mechanisms allow the characterization of gratings for all angles of diffractions. For CCD testing, network commands allow the facility to get raw images, compute and record QE curves for further detector characterization.
Influence of attachment styles on romantic relationships.

This investigation examined the impact of secure, anxious, and avoidant attachment styles on romantic relationships in a longitudinal study involving 144 dating couples. For both men and women, the secure attachment style was associated with greater relationship interdependence, commitment, trust, and satisfaction than were the anxious or avoidant attachment styles. The anxious and avoidant styles were associated with less frequent positive emotions and more frequent negative emotions in the relationship, whereas the reverse was true of the secure style. Six-month follow-up interviews revealed that, among those individuals who disbanded, avoidant men experienced significantly less post-dissolution emotional distress than did other people. In recent years, a growing number of researchers have become interested in the processes by which people develop, maintain, and dissolve affectional bonds within close relationships (see Bretherton, 1985; Clark & Reis, 1988). Empirical research in this area was spawned by the pioneering theoretical work of John Bowlby (1969,1973,1980), who sought to determine how and why infants become emotionally attached to their primary caregivers and why they often experience emotional distress when physically separated from them. Bowlby identified a clear sequence of three emotional reactions that typically occur following the separation of an infant from its primary caregiver: protest, despair, and detachment. Given the remarkably reliable nature of this sequence across a variety of different species, Bowlby developed a theory of attachment grounded in evolutionary principles. Specifically, he argued that an attachment system composed of specific behavioral and emotional propensities designed to keep infants in close physical proximity to their primary caregivers might have been selected during evolutionary history. By remaining in close contact with caregivers who could protect them from danger and predation, infants who possessed these attachment propensities would have been more likely to survive to reproductive age, reproduce, and subsequently pass these propensities on to future generations. Empirical research examining tenets of Bowlby's theory has focused mainly on different styles or patterns of attachment in young children. Ainsworth, Blehar, Waters, & Wall (1978) have identified three primary attachment styles: anxious/ambivalent
Enhancement of Emissive Properties for In-Space High-Temperature Radiator Materials

DOI: 10.2514/1.31101 This study investigates emissive properties as a function of time and temperature of niobium and tantalum, for which the surfaces have been altered by an arc-texturing technique. To date, space radiators achieve relatively high emissivity at moderate temperature with specially developed paints and coatings. The emissive performance of arctextured surfaces is compared with the emissive capability of untreated andsandblasted surfaces at temperatures of 1300 and 1700 K. Arc-texturing produces surfaces with emissivity coefficients between 0.6 and 0.9, which translates into an enhancement of about two to four times when compared with untreated or sandblasted samples. Material characterization techniques such as optical microscopy, scanning electron microscopy, stylus-type prolifometry, energy-dispersive x-ray spectroscopy, and x-ray diffractometry are employed to study the geometric topology of altered surfaces. These techniques assist in unlocking the mechanisms that are ultimately responsible for emissivity behavior as a function of time and temperature and that consequently lead to manufacturing processes of desirable morphologies.
Photorefractive two-wave mixing in tantalum-doped potassium niobate

Photorefractive gain is measured in poled, 1% tantalum-doped Potassium Niobate (KNbO3). Two-wave mixing experiments are presented which exploit the r42 coefficient of KNbO3 by employing non-symmetric geometries which rotate the grating vector away from the optic axis. The effect of this rotation on the exponential gain coefficient is showr. Experimental results are compared to an analytic expression derived for this parameter. The experiments were performed using an Argon laser stabilized at X=51 4.5 nm. The light was extraordinarily polarized and ihe beams were incident on the b-face of the crystal. The absorption and the response time of the crystal were measured. Losses due to scattering and self-pumped phase conjugation were also investigated.
Status of pancreatic transplants and mechanical devices for blood glucose control in diabetes.

Many of the long-term complications seen in insulin-dependent diabetic patients are not averted by conventional modes of insulin therapy. A commonly expressed hypothesis is that more intensive efforts directed at improved metabolic control in diabetic subjects may result in a decrease of long-term complications. Therefore, increasing attention is being devoted to development of strategies designed to achieve improved blood glucose and metabolic control in insulin-dependent diabetic subjects. The approaches can be divided into three categories: [1] Transplantation, [2] Mechanical devices, and [3] Intensive, conventional therapy. The development of the transplantation approach requires resolution of the problem of rejection and the need for immunosuppression. Recent studies indicate that islet transplantation may be performed without long-term immunosuppression. Closed-loop devices for use at the bedside are available at the present time for short-term investigational use. A device for long-term portable use is not available because of the lack of an adequate glucose sensor. Open-loop devices are currently available that enable long-term clinical studies in humans. Some patients have used these devices at Washington University for over two years. In a few, there has been reversal of some of the neuropathy with retinal vascular leakage and near normal, long-term metabolic control. Some findings in over twenty patients studied long-term include the following: 1. Reduction of postprandial hyperglycemia is possible with intravenous. subcutaneous, or intraperitoneal insulin delivery; 2. Hypoglycemia remains the most common problem seen in ambulatory patients treated with open-loop pumps and necessitates glucose monitoring by the patient at home; 3. Long term “normalization” of plasma glucose is not achieved with openloop systems; 4. Maturity onset diabetic patients are easier to control than juvenile onset diabetics; 5. Some patients tolerate hypoglycemia better than others and this may determine who does well long-term; 6. Long-term subcutaneous insulin delivery is safe, whereas other forms of insulin delivery carry a greater risk; 7. Peripheral hyperinsulinemia is frequently found in patients treated by open-loop methods and may have long-term detrimental effects; 8. Behavioral and psychosocial variables may influence long-term results and have not been studied in detail; 9. The primary clinical use of open-loop systems in diabetic patients at the present time is their use in pregnancy and in patients unresponsive to conventional therapy.
Correlation is not causation: a case study of fisheries, trophic state and acidity in Florida (USA) lakes

Abstract Environmental pollution studies are often based on observational data and correlative statistics that indicate relationships between pollutants and ecological or human health attributes. Such relationships should be considered preliminary information from which hypotheses can be developed. Often, however, they are used as the basis for inferring cause and effect. That approach can lead to erroneous decisions about pollution control, resource management, or human health standards. This is illustrated using a case study involving fisheries, trophic state attributes (nutrients and algal biomass), and lake water acidity. Fish biomass in Florida lakes is positively correlated with nutrient concentrations and algal biomass, perhaps indicating that fish are controlled by resource availability. However, fish biomass is inversely correlated with hydrogen ion concentration, perhaps indicating that fish decline in acid lakes due to physiological stress or changes in food web structure. Both explanations are ecologically sound, but they point to drastically different resource management strategies: lake fertilization versus neutralization. This issue and others in the environmental pollution arena cannot be fully resolved until experimental research and ecological process studies are coupled with the collection of standard observational data. ©
Distributed Collision-Avoiding Deployment Control of Multiple Nonholonomic Mobile Robots

This paper presents a distributed second-order control algorithm for deploying a group of nonholonomic mobile robots into an unknown environment to establish and maintain desired sensor coverage. The general control framework is formulated based on Hamilton’s principle. The control input is defined in the form of a potential/force field. A multi-robot collision avoidance scheme is also presented. The effectiveness of the proposed deployment control scheme is verified through both simulations and experiments. Main performance factors, including equilibrium deployment configuration, convergence of inter-robot coverage distance and collision avoidance, are presented and analyzed.Copyright © 2011 by ASME
Ultramafic Rocks from the Mid-Atlantic Ridge

ACCORDING to the ideas of Hess1 the backbone of active mid-oceanic ridges should consist of peridotites which originated in the Earth's mantle and were subsequently upthrusted into the crust along the axis of ridges, above the up welling limbs of mantle's thermal convection cells. The ultramafics should lie below a layer of basalt about 1 km thick, generated by partial melting of the upwelling mantle material.
Strategies for Overcoming EGFR Resistance in the Treatment of Advanced-Stage NSCLC

Patients whose tumors harbor somatic-activating mutations within the epidermal growth factor receptor (EGFR) gene define a clinically distinct molecular cohort of lung cancers with increased sensitivity to the EGFR tyrosine kinase inhibitors (TKIs), including the “first-generation” reversible inhibitors, erlotinib and gefitinib, and the “second-generation” irreversible inhibitors, afatinib and dacomitinib. Several, large, phase III studies have shown already that patients with EGFR-mutant tumors display radiographic response rates of >60 % and improved progression free survival (PFS) when treated with an EGFR TKI compared with chemotherapy. Unfortunately, despite these initial responses, patients inevitably develop progressive disease, a concept referred to clinically as acquired resistance. Novel strategies are needed to delay or overcome acquired resistance to EGFR TKIs. These strategies include second-generation EGFR inhibitors, rationale combinations of targeted small molecule inhibitors and/or monoclonal antibodies, and addition of traditional cytotoxic chemotherapy to EGFR TKI therapy at the time of progression. Unfortunately, to date, there is no genotype-specific standard of care, and enrollment of patients with acquired resistance to EGFR TKIs into clinical trials specifically addressed at overcoming resistance is paramount to continue to advance the field and to improve outcomes for these patients.
Study of the ρ ( 1710 ) at 8.0 and 18.5 GeV/ c

We have studied the reaction ${\ensuremath{\pi}}^{\ensuremath{-}}p\ensuremath{\rightarrow}p{\ensuremath{\rho}}^{\ensuremath{-}}(1710)\ensuremath{\rightarrow}p{\ensuremath{\pi}}^{+}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{\ensuremath{-}}{\ensuremath{\pi}}^{0}$ at 8.0 and 18.5 GeV/c. Evidence is presented for the dominance of the ${\ensuremath{\rho}}^{\ensuremath{-}}{\ensuremath{\rho}}^{0}$ decay mode. An upper limit of 39% for $A \ensuremath{\pi}$ decay relative to all $4\ensuremath{\pi}$ decay modes is determined for the ${\ensuremath{\rho}}^{\ensuremath{-}}(1710)$. Assuming only $\ensuremath{\rho}\ensuremath{\rho}$ and $\ensuremath{\omega}\ensuremath{\pi}$ decay modes contribute, we find $\frac{[\ensuremath{\rho}(1710)\ensuremath{\rightarrow}\ensuremath{\rho}\ensuremath{\rho}]}{[\ensuremath{\rho}(1710)\ensuremath{\rightarrow}\mathrm{all} 4\ensuremath{\pi}]}=(78\ifmmode\pm\else\textpm\fi{}33)%$ and $\frac{[\ensuremath{\rho}(1710)\ensuremath{\rightarrow}\ensuremath{\omega}\ensuremath{\pi}]}{[\ensuremath{\rho}(1710)\ensuremath{\rightarrow}\mathrm{all} 4\ensuremath{\pi}]}=(22\ifmmode\pm\else\textpm\fi{}8)%$. If the $\ensuremath{\rho}(1710)$ is identical to the $g(1680)$, we find $\frac{(g\ensuremath{\rightarrow}2\ensuremath{\pi})}{(g\ensuremath{\rightarrow}4\ensuremath{\pi})}=0.35\ifmmode\pm\else\textpm\fi{}0.11$. The mass and width of the $\ensuremath{\rho}(1710)$ determined from the ${(4\ensuremath{\pi})}^{\ensuremath{-}}$ mass spectrum are 1.687 \ifmmode\pm\else\textpm\fi{} 0.020 GeV and ${0.169}_{\ensuremath{-}.048}^{+.070}$ GeV, respectively. The production cross section is determined as a function of energy and, if a function of the form $\ensuremath{\sigma}=A_{\mathrm{lab}}^{}{}_{}{}^{\ensuremath{-}n}$ is assumed, we find $n={1.4}_{\ensuremath{-}0.3}^{+0.5}$. The distribution of four-momentum transfers, ${t}^{\ensuremath{'}}=t\ensuremath{-}{t}_{min}$, for $\ensuremath{\rho}(1710)$ production is characterized by a two-slope distribution with ${\ensuremath{\alpha}}_{1}\ensuremath{\approx}9.6$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{\ensuremath{-}2}$ for ${t}^{\ensuremath{'}}\ensuremath{\lesssim}0.3$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$ and ${\ensuremath{\alpha}}_{2}\ensuremath{\approx}2.1$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{\ensuremath{-}2}$ for ${t}^{\ensuremath{'}}\ensuremath{\gtrsim}0.3$ ${(\mathrm{G}\mathrm{e}\mathrm{V}/\mathit{c})}^{2}$.
Data Acquisition at the Bevalac, an Example: The HISS Facility

The Heavy Ion Spectrometer System (HISS) is a relativistic heavy ion research facility at the Bevalac accelerator complex, Lawrence Berkeley Laboratory (LBL). This spectrometer can provide fields of up to 30K gauss within a volume of more than 3 cubic meters. This facility is equipped with a number of large, flexible detector systems. Over the last four years, a loosely coupled data acquisition and analysis system has been written for use at this facility. This system will be described in detail with particular emphasis on development of high data rate capabilities.
Estimation of the dynamic cavitation tension of water by a shock tube method

Abstract A review is conducted into existing work related to the role bulk cavitation plays during the interaction between a submerged structure and an underwater shock wave. This survey, dealing both with the classical works of Temperley and Cushing as well as recently published studies by the writer, is focused on two important variations from the assumptions made in earlier works. One of these variations, the possibility that water has a non-zero cavitation tension, is studied further by developing a theoretical model to predict the fluid dynamics following a free surface reflection. By introducing experimental data for comparative purposes, it is concluded that, at laboratory scale, the dynamic cavitation tension may be regarded as zero.
Generation of Unstable Modes of the Iceward-attenuating Swell by Ice Breeze

Abstract A thermally forced surface wind (ice breeze) is introduced to Wadhams' model for investigating the effects of ice breeze of iceward-attenuating ocean waves. The wave solutions show that the ice breeze generates growing modes which have the same phase speed as Wadhams' model. The growth rate increases with augmentation of the mean surface temperature gradient and decreases with augmentation of ice thickness. In the frequency spectra, the growth rate has a single peak near 0.1 Hz. It is found that ice thickness affects the location of this peak in the frequency spectra. The thicker the ice, the lower the frequency where the peak is situated. The similarity of the frequency spectra between the growth rate and observed energy density implied that ice breeze may play some role in iceward-propagating waves.
Grain size dependent shear instabilities in body-centered and face-centered cubic materials

The grain size dependence of the mechanical response has been a topic of immense interest in nanostructured (NS) materials. Most NS metals produced by grain refinement processes show characteristically different work hardening and rate sensitivity from their coarse-grained counterparts. These differences, coupled with novel deformation mechanisms in NS materials, have direct implications on the stability of the plastic deformation process. Recently, we proposed a model for grain rotation based geometric softening within a visco-plastic constitutive setting to investigate grain size dependent shear instabilities in NS metals. Using this model, we investigate the effects of internal material hardening on the shear instabilities in NS body-centered cubic and face-centered cubic metals at quasi-static loading rates. At small grain sizes, the model predicts occurrence of the shear bands for both b.c.c. and f.c.c. materials as a consequence of the dominance of geometric softening over material hardening. However, in NS face-centered cubic materials the occurrence of instability is delayed due to elevated rate sensitivity compared NS body-centered cubic materials.
Transfer programs and aggregate household formations.

The number of households in the United States increased by over fifty percent in the 1960s and 1970s, nearly double the rate of population growth. Part of the increase is explained by the movement of large cohort groups of the population into prime household-forming age categories, but higher headship rates also contribute. Age-specific headship rate increases result from non-demographic factors, and this paper focuses on the role of government transfer payment programs. Specifically considered are Social Security, Aid to Families with Dependent Children, and Food Stamps. These programs are found to have accounted for as many as 4 million net household formations between 1961 and 1984. The findings have implications for expected households formations in the 1990s.
ISB news from the Chair of the Student and New Professionals Group

An update from the new Chair of the Students and New Professionals Group of the International Society of Biometeorology.
Synthesis of Comb Polysiloxane Polyelectrolytes Containing Oligoether and Perfluoroether Side Chains

Comb polyelectrolytes consisting of a polysiloxane backbone with tetraglyme and lithium-sulfonate terminated perfluoroether side chains have been synthesized. Both types of side chains were indepen...
Fluorescence self-quenching of ethidium bromide intercalated in DNA

Fluorescence lifetimes of free and DNA-intercalated ethidium bromide have been established in different studies to be 1.6 - 1.8 and 20 - 25 ns, respectively. Recently, several researchers have suggested a new DNA-binding mode of ethidium based on a third fluorescence lifetime between 10 and 15 ns. We are able to reproduce the latter lifetime in ethidium:DNA complexes only when the ligand per DNA base-pair ratio (r) exceeds 0.2. Other criteria that may affect the binding properties of ethidium, such as temperature, salt concentration, length of the DNA (end effects), and base composition of the DNA only influence the appearance of this new lifetime because of their effect on the spatial distribution of intercalated ethidium. Based on single curve and global analysis of fluorescence intensity and fluorescence anisotropy decay data, we propose that the new lifetime is due to self-quenching of intercalated ethidium. Detectable quenching occurs at average intercalation site separations of less than 10 base- pairs.
A Noninvasive Method for Estimating Nitrogen Balance in Free-Ranging Primates

The vital role of body protein as an energy reserve has received little focus in studies of wild primates. Owing to the relatively low protein content of fruit, some frugivorous primates could face a protein deficit if body protein is catabolized for energy during periods of low fruit availability. Such an imbalance can be detected if fatty acids, amino acids, and nitrogen (N) catabolites are reincorporated or recycled back to tissues. Here we describe a method to quantify protein recycling by measuring standardized urea concentration and N isotope signatures from urine samples collected from wild Bornean orangutans (Pongo pygmaeus wurmbii). Our overall goal was to explore if concentrations of urea and δ15N values could be used as indicators of the amount of protein consumed and the degree of protein recycling, respectively, in wild, free-ranging primates. We examine the relationships between urea concentration, δ15N values, protein intake, and fruit availability. Urea concentration increased with fruit availability, reflecting a slight increase in protein consumption when fruit was abundant. However, we found no relationship between δ15N values and fruit availability, suggesting that orangutans avert a negative protein balance during periods of low fruit availability. These noninvasive methods complement recent advances in primate energy balance research and will contribute to our understanding of adaptations of primates during periods of fruit shortage.