cssi/SciSciGPT-SciSciNet huggingface dataset:
Extending the dynamic range of silicon photomultipliers without increasing pixel count

Abstract A silicon photomultiplier, sometimes called “multipixel photon counter”, which we here refer to as a “SiPM”, is a photo-sensitive device built from an avalanche photodiode array of pixels on a common silicon substrate, such that it can detect single photon events. The dimensions of a pixel may vary from 20 to 100 μm and their density can be greater than 1000 per square millimeter. Each pixel in a SiPM operates in Geiger mode and is coupled to the output by a quenching resistor. Although each pixel operates in digital mode, the SiPM is an analog device because all the pixels are read in parallel, making it possible to generate signals within a dynamic range from a single photon to a large number of photons, ultimately limited by the number of pixels on the chip. In this note we describe a simple and general method of increasing the dynamic range of a SiPM beyond that one may naively assume from the shape of the cumulative distribution function of the SiPM response to the average number of photons per pixel. We show that by rendering the incoming flux of photons to be non-uniform in a prescribed manner, a significant increase in dynamic range is achievable. Such re-distribution of the incoming flux may be accomplished with simple, non-focusing lenses, prisms, interference films, mirrors or attenuating films. Almost any optically non-inert interceding device can increase the dynamic range of the SiPM.
7‐Benz[c] acridinemethanols as tetracyclic analogs of the 2‐phenyl‐4‐quinolinemethanol antimalarials

A series of new 7-benz[c]acridinemethanols and 5,6-dihydro-7-benz[c]acridinemethanols was prepared as rigid, tetracyclic analogs of the antimalarial 2-phenyl-4-quinolinemethanols. Condensation of 5,7-dichloroisatin with 6-chloro-, 7-chloro-, and 6,7-dichloro-1-tetralone furnished halogenated 5,6-dihydro-7-benz[c]acridinecarboxylic acids, which were transformed into the corresponding acid chlorides, acyl malonates, α-bromomethyl ketones, and epoxides. Fully aromatic members of the series obtained via dehydrogenation of the 5,6-dihydro acids were likewise converted into epoxides via the acylmalonate route. Although all the epoxides studied proved to be exceptionally resistant to ring-opening by di-n-butylamine, probably on account of steric effects, they could be cleaved readily with piperidine or morpholine. Nmr spectra of the resulting amino alcohols suggest that these compounds exist in a single preferred conformation stabilized by internal O-H····N hydrogen bonding, and that free rotation about the side chain C-C bond does not occur at room temperature.
DOES THE THEORY OF THE 'CORE' EXPLAIN WHY AIRLINES FAIL TO COVER THEIR LONG-RUN COSTS OF CAPITAL?

Abstract The major air transport markets at the early part of the 21st century are failing to generate sufficient revenues to cover their long-run costs. Many airline are being supported by subsidies, going out of business (e.g. Sabena, Ansett, Canadian International, Swissair) or having to resort to various forms of financial restructuring such as afforded by Chapter 11 bankruptcy laws in the US (US Airways, Midway, National). The effects of the terrorist attacks of September 2001 have exacerbated this situation, but the data suggests the problem be more deep routed in the ‘deregulated’ markets that now exist in many parts of the world. This paper concerns itself with the issue of whether there are intrinsic features of the scheduled network airline industry that makes the current structure of liberalized markets unsustainable. It highlights on a number of features of this market but pays particular attention to the question of whether the market is naturally prone to excesses in competition that, because of its nature, forces airline fares down to the level where full costs cannot be recovered. It focuses in this sense on a long established concept in economics, namely does a core exist in this market. The fact that there is prima face evidence to suggest that the core is empty then leads to a discussion of appropriate policy reactions that may allow a more sustainable market structure to survive.
Farmers’ Supply Response, Price of Corn Residue, and Its Economic Viability as an Energy Feedstock

Previous economic analyses of energy from corn stover assumed yield reductions from residue removal (without nutrient replacement) and limited or no supply response by farmers to changes in the price of stover. We exploit agronomic and cost information from a randomized block design experiment to model and quantify farmers’ supply response to changes in relative prices of corn stover, corn grain, and soybean. We then couple this supply response with a model of a cost-minimizing processing plant. Results suggest that stover-based energy may be closer to economic viability than previously found. In addition, in areas where reductions in corn yield due to corn monoculture are small, processing plants may find optimal to pay a higher price for stover to induce farmers to adopt continuous corn because it reduces transportation cost. This suggests that such areas may experience changes in their land cover configuration if stover-based energy does become commercially viable.
5-Hydroxyindole metabolism in the brain after hepatectomy

Abstract The concentrations of 5-hydroxytryptamine (5-HT) and 5-hydroxyindoleacetic acid (5-HIAA) increased in the brain of dogs and rats after complete hepatectomy, the increases of 5-HIAA being greater than those of 5-HT. The increase in concentration of both 5-hydroxyindoles was much smaller than that of the precursor, tryptophan (Try). The demonstration of radioactive 5-HT and 5-HIAA in the brain of normal and hepatectomized rats after the intradiencephalic injection of l -Try-3- 14 C indicated that hydroxylation of Try occurred in brain in vivo . However, the intravenous injection of Try (33 mg/kg) resulted in definite increases in the concentration of 5-hydroxyindoles in the brain of normal rats and only marginal increases in the brain of hepatectomized rats. After intravenous injection of d , l -5-hydroxytryptophan, conversion to 5-HT was essentially similar in normal dogs and in dogs in coma after complete hepatectomy.
Temporal trends in ethoxyresorufin‐o‐deethylase activity of brook trout (Salvelinus fontinalis) fed 2,3,7,8‐tetrachlorodibenzo‐p‐dioxin

Changes in ethoxyresorufin- O-deethylase (EROD) activity were monitored through an extended 6-month dietary exposure to determine the relationship between EROD activity and uptake of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) in brook trout, Salvelinus fontinalis. Brook trout were fed labeled TCDD during a 4-week loading phase and an 11-week maintenance phase to achieve whole-body concentrations of 0, 75, 150, 300, 600, and 1,200 pg TCDD/g fish. A spawning phase followed during which no TCDD was introduced. The TCDD had an extended half-life, with maximal levels detected in the late loading-early maintenance phases and 81 d after TCDD had been removed from the diet. Accumulation in liver increased as whole-body target concentration increased but was generally less than half of anticipated whole-body target concentrations. The EROD activity demonstrated a dose-dependent increase. Positive correlations were observed between EROD activity and TCDD body burdens for both males and females. For males, maximal induction was attained early in the maintenance phase and maintained during latter phases. For females, induction was characterized by a biphasic pattern. Maximal induction was attained during late loading-early maintenance, with an attenuated response observed just before spawning. In addition, the induction response was modulated by sex, as induction was lower in females when compared with males. If sexual biases are considered, increased EROD activity may serve as an indicator of level of TCDD exposure and a sublethal predictor of effects of exposure.
High-Speed Videography Instrumentation And Procedures

High-speed videography has been an electronic analog of low-speed film cameras, but having the advantages of instant-replay and simplicity of operation. Recent advances have pushed frame-rates into the realm of the rotating prism camera. Some characteristics of videography systems are discussed in conjunction with applications in sports analysis, and with sports equipment testing.© (1982) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Theory of radiontless transitions for large molecules

Abstract A new general approach to the theory of radiationless transitions is outlined, and worked out in a detailed, simplified form. The result shows an exponential dependence of the radiantionless lifetime on energy, in close quantitative agreement with the recently observed energy dependence of the radiationless transitions in β-naphtylamine.
Family Concepts and Their Measurement: Things Are Seldom What They Seem

An empirical examination of the degree of association of dimensions elicited by two family assessment instruments is presented. There were no associations among dimensions whose descriptors suggested a good amount of similarity. The results strongly suggest additional study of correspondence among assessment methods that appear to tap similar family properties, with particular attention directed to the correspondence between self-report and direct observational procedures.
Electronic characterization of defect sites on Si(001)-(2 × 1) by STM

A study of the defect sites on Si(001)-(2 × 1) was undertaken by employing comparative scanning tunneling spectroscopy (CSTS). Ni induced defects, the A, B, and C defects, and the A and B steps were studied. The STM tip induced band bending significantly affects tunneling spectra. This is evident from a comparison of LDOS and local surface potentials obtained for high (10 Ω cm) and low (100 Ω cm) doped Si(001) crystals. Decay in the local surface potential was found around the Ni induced “split off dimer” defect site and in the “vacancy channel” defect. In agreement with previous studies, a reduction in the surface states energy gap was observed for the C defect. The B step and the C terrace defect reveal similar LDOS. This is interpreted as indicating that the C defect on the terraces migrates preferentially to the B step edge, and that it is due to a surface impurity such as Cl or a product of H2O decomposition. This may be responsible for preferential etching phenomena or evaporation at step edges.
Skin conductance response during laboratory stress in combat veterans with posttraumatic stress disorder.

Objective: The primary objective was to assess Skin Conductance Response (SCR) to a laboratory stressor in combat veterans with Posttraumatic Stress Disorder (PTSD) compared to controls. The secondary objective was to evaluate the relationship between SCR and PTSD symptom clusters. Method: 15 combat/PTSD, 15 combat/no PTSD, 15 no combat/no PTSD veterans had their SCR recording during aversive pictures from the International Affective Picture Scale. Results: The groups had similar demographics and medical history (all p>0.05). SCR was different between groups (F(2,42)=4.34, p=0.02). The combat/PTSD group had the highest response compared to both control groups. Numbing-avoiding was predictive of SCR (F(1,42)=12.72, p=0.001), while re-experiencing and hyper-arousal were not (p’s>0.05). Conclusions: Increased SCR in the PTSD group validates previous studies (Numbing-avoiding). PTSD cluster scores correlated with SCR values. These findings support current PTSD therapies that reduce avoidance behaviors.
Preparation and some properties of a soluble nitrate reductase from Rhizobium japonicum

A method was developed for the preparation of a soluble nitrate reductase extract of Rhizobium japonicum cells derived from pure cultures of the organisms or from soy-bean nodules. In the procedure the bacterial suspension, glass beads and small quantities of sodium hydrosulfite and benzylviologen were sealed in a Tygon plastic tube. The cells were broken by a series of grinding and freezing and thawing operations. The cell-free extract was collected by centrifugation. The soluble enzyme preparation is extremely susceptible to oxidation. It was necessary to maintain completely reduced conditions throughout the purification procedures and the experimental operations in which properties of the enzyme were investigated. A simple assay procedure was developed in which benzylviologen (reduced by sodium hydrosulfite) was employed as the electron donor. Since excess reducing agent was present in assay tubes, assays could be conducted under aerobic conditions and still maintain reduced conditions in the reaction mixtures. The excess sodium hydrosulfite was oxidized at the end of the assay periods by vigorously shaking each tube in air. After this the nitrite in each reaction mixture was determined by a colorimetric procedure. The soluble enzyme was purified about 11-fold by (NH4)2SO4 fractionation and chromatography on a calcium phosphate column. Attempts to purify extracts containing sodium hydrosulfite but lacking benzylviologen were unsuccessful. NADH2 and succinate, which were effective electron donors for a particulate enzyme preparation from R. japonicum, were completely ineffective donors for nitrate reduction with the soluble preparation. A series of compounds were tested in an attempt to find a naturally occuring electron donor, but reduced benzyl-or methyl-viologen were the only compounds that functioned with the soluble enzyme. The effects of pH, substrate concentration, and various inhibitors on the activity of the enzyme, were investigated.
Relationship Commitment and Perceptions of Harm to Self

Commitment to a relationship is associated with a number of consequences, including willingness to sacrifice for the relationship, greater cognitive interdependence between partners, and increased trust in one's partner. Consistent with such consequences, we hypothesized that greater commitment is associated with decreased perceptions of one's partner as a source of harm to the self. We conducted two studies (one correlational, one experimental) to test hypotheses regarding the association between commitment level and personal harm perceptions, based on tenets from interdependence theory and balance theory. Study 1 revealed significant negative associations between commitment and personal harm perceptions. Results from Study 2 suggest that greater commitment leads to decreased perceptions of partner-based risk and increased risky behavioral tendencies.
Dynamic ground compliance in multistorey buildings

Abstract A study is presented of the changes in the characteristics of the natural modes of vibration for multistorey structures which are founded on flexible foundations. First a standard eigenvalue problem is formulated for the proportionally damped case. Then general relationships of changes in natural frequencies and mode shapes are derived for the linear vibration theory. By means of an example problem it is demonstrated, however, that only the first mode obeys the predicted changes of frequencies and mode shapes over a wide range of foundation stiffness. The higher modes are shown to deviate substantially from the linear behaviour. This deviation is ascribed to geometric changes in mode shapes.
The solubility of olivine in basaltic liquids: an ionic model

A model is presented which enables the temperature at which olivine is in equilibrium with any alkali-depleted basaltic compound to be calculated to within + or - 30 C. It is noted that the error increases substantially when applied to terrestrial basalts which contain several weight percent alkalis. In addition the model predicts and quantifies the reduced activity of SiO4(4-) monomers due to increasing SiO2 concentrations in the melt. It is shown that the coordination of alumina in melts which precipitate olivine only appears to be dominantly octahedral, while titanium acts as a polmerizing agent by interconnecting previously isolated SiO4(4-) monomers. It is concluded that the model is sufficiently sensitive to show that there are small repulsive forces between Mg(2+) and calcium ions which are in association with normative diopside in the melt.
MAGNETIC PROPERTIES OF RARE EARTH--LEAD INTERMETALLICS.

Abstract Magnetic susceptibilities of the series of intermetallics represented by the formula RPb3 (R = Ce, Pr, Nd, Sm, Eu and Gd) are reported for temperatures ranging from 2.8 to 300°K. Curie-Weiss behavior is noted for all compounds except SmPb3 with slopes in good agreement with that expected for assemblages of free tripositive ions (dipositive for EuPb3). The behavior of SmPb3 is in accordance with the behavior usually observed for Sm compounds and is due to the narrowness of the multiplet spacing in the tripositive samarium ion. PrPb3 exhibits Van Vleck paramagnetism below 15°K; its susceptibility-temperature behavior is analyzed in terms of an overall crystal field splitting of 80°K. Results indicate the possible onset of antiferromagnetism at 17 and 22°K for GdPb3 and EuPb3, respectively. The other compounds give no indication of forming a cooperative magnetic phase at temperatures down to 2.8°K.
Effects of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD) on humoral immunity: II. B cell activation.

Abstract Previous reports have indicated similarities in the actions of 2,3,7,8-tetrachlorodibenzo- p -dioxin (TCDD) and the polyclonal B cell activator Staphylococcus aureaus Cowan Strain I (SAC) on the in vitro T-dependent antibody responses to SRBC. This finding has suggested that B cell activation is likely to be an important component in the direct effects of TCDD on lymphocyte function. In the current investigation, various techniques were employed to determine whether TCDD could cause the activation of splenic-derived dense resting B cells in the absence of antigen and to determine if the modulatory effect of serum-derived growth factors in the result of a direct action on the B lymphocyte. TCDD (30 and 60 nM) caused an increase in proliferation of dense resting B cells at both 72 and 96 h following addition. This action of TCDD was demonstrated to possess a serum dependency that was based on the lot of serum in which the cells were cultured. Under similar conditions, TCDD (30 nM) stimulated an increase in total IgM secretion as measured on day 7 of culture. A similar profile of activity was observed in vivo, where splenic-derived dense resting B cells from animals treated with 1 μg/kg TCDD for 5 days, but unsensitized to SRBC, demonstrated a 10-fold increase in proliferation on day 3 of culture which likewise occurred in a serum dependent manner. In addition, we observed that mice treated with 1 μg/kg TCDD for 5 days and sensitized with SRBCs, sustained a complete loss in their splenic-derived dense B cell populations (day 4 after sensitization). The loss of this B cell population is indicative of a movement of these cells into a blastogenic state of activation and is not observed in matched corn oil-treated controls. These findings support our previous observations and give evidence that TCDD is capable of causing the direct activation of resting B cells. This activation is dependent on the type of serum present during in vitro culture and appears to be intensified in the presence of antigen in vivo.
Improving Finite State Impedance Control of Active-Transfemoral Prosthesis Using Dempster-Shafer Based State Transition Rules

Finite state impedance (FSI) control is a widely used approach to control active-transfemoral prostheses (ATP). Current design of state transition rules depends on hard thresholding of intrinsic mechanical measurements, which cannot cope well with uncertainty related with intra- and inter-subject variations of these intrinsic recordings. In this study, we aimed to generate more robust FSI control of ATP against these variations by using Dempster-Shafer theory (DST)-based transition rules. The FSI control with DST-based rules was implemented on an instrumented ATP, evaluated on five able-bodied subjects and one patient with a unilateral transfemoral amputation. Then the DSP based transition rules were compared to the control with hard threshold (HT)-based transition rules. The results showed that when compared to the hard thresholding approach, the DST yielded enhanced accuracy in state transition timing and reduced control errors when intra- and inter-subject variations were presented. Additionally, the parameters of DST-based rules were uniform for all the subjects tested, allowing for easy and efficient transition rule design and calibration. The outcome of this study can lead to further improvement of robust, practical, and self-contained ATP design, which in turn will advance the motor function of patients with lower limb amputations.
A mass balance of chlorophyll degradation product accumulation in Black Sea sediments

Abstract The distribution of chlorophyll degradation products was measured in Black Sea sediment trap and sediment samples. Chlorophyll degradation products were identified as free phorbins, phorbin steryl esters, high molecular weight chlorophyll degradation products, and acid extractable chlorophyll degradation products. When all these sinks are considered, an inventory of chlorophyll degradation products can be established which identifies four times more sedimentary phorbins than standard HPLC studies alone. The concentration of total chlorophyll degradation products in the sediment trap samples varies with season and, in the sediments, increases with depth from Unit I into Unit II. In Unit III sediments, the total phorbin concentration dramatically decreases. These trends are similar to those of the total organic carbon concentration. Variations in the ratio of total phorbin/total organic carbon with depth in the sediments appear to be related to previously suggested changes of oxygen concentrations over time in the Black Sea water column. This new data was combined with data from the literature to create a mass balance of chlorophyll flux, degradation, and accumulation in the Black Sea. It is concluded that once chlorophyll degradation products reach the anoxic water column, they survive to be deposited in the underlying sediments. Although a larger percentage of total organic carbon, compared to total phorbin, passes out of the photic zone. the phorbin macrocycle appears to be more stable under anoxic conditions than is total organic carbon.
GPS Tracking and the Law Enforcement Role

An international trend involving the use of electronic technology to supervise sex offenders has broadened the role of justice system officials charged with protecting the public from sex offenders. Guidance has been offered to probation and parole officers to help them utilise this technology in their supervision efforts. Virtually no guidance has been offered to police officers who will likely play an important role in the use of this technology as it expands in their jurisdictions. This article reviews the use of GPS technology for sex offenders with the aim of identifying how different aspects of the technology are relevant to police officers. Attention is also given to the law enforcement role in utilising this technology as part of the collaborative supervision of sex offenders.
Medusae, siphonophores, and ctenophores as planktivorous predators in changing global ecosystems

Medusae, siphonophores, and ctenophores are planktivorous predators operating at higher trophic levels in marine ecosystems of a wide range of productivity. It has been hypothesized that high-productivity ecosystems such as areas of upwelling tend towards food chains dominated by larger phytoplankton, large copepods, and ultimately many species of fish rather than gelatinous predators; ecosystems with lower productivity are characterized by small flagellate phytoplankton, small copepods, and ultimately numerous medusae and ctenophores. Evidence is provided that medusae, siphonophores, and ctenophores are actually important predators in both sorts of planktonic ecosystems, although uneven reporting in the literature may be cause for underestimates of the importance of these carnivores in some systems. As world fisheries begin to experience serious declines, it is relevant to recognize that the carnivorous “jellyfishes” are ubiquitous and are thus opportunistically positioned to utilize secondary production that is ordinarily consumed by fish.
Nuclear reorganization processes in Paramecium aurelia, with descriptions of autogamy and ‘hemixis’

In a study of the nuclear behavior of Paramecium aurelia, a process of self-fertilization, autogamy, has been discovered and traced through its essential steps. Autogamy is the counterpart, in a single animal, of conjugation. In autogamy, three micronuclear divisions lead to the formation of the gametic nuclei. These divisions are considered to be maturation divisions. The first division is characterized by a great increase in the size of the two vegetative micronuclei and the occurrence of long thread-like crescents. The second division results in the formation of eight nuclei, variable numbers of which continue to divide giving rise to the potential gametic nuclei. Two of the latter unite to form a synkaryon. The old macronucleus disintegrates. The fusion nucleus divides twice: two of the daughter nuclei become macronuclear anlagen, while the other two remain micronuclei. The macronuclear anlagen are distributed to two daughter cells at the time of the first cell division, when the micronuclei divide. The macronuclear changes in hemixis can be classified into three main types: (1) the extrusion of a relatively small number of spherical chromatin fragments; (2) the splitting of the macronucleus into two (generally) large independent portions—accompanied, or not, by the extrusion of smaller spherical bodies; (3) the complete disorganization by fragmentation of the macronucleus.
Surface currents on a perfect conductor, induced by a magnetic dipole

An oscillating magnetic dipole located near a perfect conductor induces a current density on the surface of the metal. We have derived an expression for this current density, and studied its field line patterns for various orientations of the dipole moment. When the dipole moment is perpendicular to the surface, the field lines are circles which run clockwise and counterclockwise. For a linear dipole oriented parallel to the surface, the field line pattern is much more complex, and it contains singular points. When the dipole moment rotates in a plane parallel to the surface, the field lines are spirals. A field line spirals inward from infinity to some given point, after which it spirals outward back to infinity. We have also considered the Poynting vector of the electromagnetic field near the surface, and we found that its field lines can have singular points or exhibit a vortex.
Umbilical vein blood flow determination in the ovine fetus: Comparison of Doppler ultrasonographic and steady-state diffusion techniques☆☆☆★

Abstract Objective: This study was undertaken to assess the accuracy of triplex ultrasonographic measurement of venous umbilical blood flow in comparison with the steady-state diffusion technique and to determine the impact of cotyledon weight and number on umbilical blood flow. Study Design: Six late-gestation ewes with long-term catheter placement were studied for venous umbilical blood flow with the ethanol steady-state diffusion technique and with triplex-mode ultrasonography (color Doppler, pulsed-wave Doppler, and real-time ultrasonography). At necropsy the number and weight of the cotyledons serving each umbilical vein were recorded. Results: Umbilical blood flow determined by triplex-mode ultrasonography (207.5 ± 8.6 mL · kg –1 fetus · min –1 ) was virtually identical to that determined with the steady-state diffusion technique (208.1 ± 7.3 mL · kg –1 fetus · min –1 ; P = .9). When values were normalized for the weight or number of cotyledons serving each vein, there was no difference in umbilical blood flow between small and large umbilical veins in all the sheep. Conclusions: Our study validates the accuracy of the triplex ultrasonographic method and provides justification for its use in future human investigations. In absolute terms umbilical blood flow frequently differs between the 2 veins. When expressed per number or mass of cotyledons, however, the umbilical blood flows are similar. (Am J Obstet Gynecol 1999;181:1149-53.)
Tillage system and crop rotation effects on dryland crop yields and soil carbon in the central Great Plains

Winter wheat (Triticum aestivum L.)-fallow (WF) using conventional stubble mulch tillage (CT) is the predominant production practice in the central Great Plains and has resulted in high erosion potential and decreased soil organic C (SOC) contents. This study, conducted from 1990 through 1994 on a Weld silt loam (Aridic Argiustoll) near Akron, CO, evaluated the effect of WF tillage system with varying degrees of soil disturbance [no-till (NT), reduced till (RT), CT, and bare fallow (BF)] and crop rotation [WF, NT wheat-corn (Zea mays L.)-fallow (WCF), and NT continuous corn (CC)] on winter wheat and corn yields, aboveground residue additions to the soil at harvest, surface residue amounts at planting, and SOC. Neither tillage nor crop rotation affected winter wheat yields, which averaged 2930 kg ha -1 . Corn grain yields for the CC (NT) and WCF (NT) rotations averaged 1980 and 3520 kg ha -1 , respectively. The WCF (NT) rotation returned 8870 kg ha -1 residue to the soil in each 3-yr cycle, which is 2960 kg ha -1 on an annualized basis. Annualized residue return in WF averaged 2520 kg ha -1 , which was 15% less than WCF (NT). Annualized corn residue returned to the soil was 3190 kg ha -1 for the CC (NT) rotation. At wheat planting, surface crop residues varied with year, tillage, and rotation, averaging WCF (NT) (5120 kg ha -1 ) > WF (NT) (3380 kg ha -1 ) > WF (RT) (2140 kg ha -1 ) > WF (CT) (1420 kg ha -1 ) > WF (BF) (50 kg ha -1 ). Soil erosion potential was lessened with WCF (NT), CC (NT), and WF (NT) systems because of the large amounts of residue cover. Levels of SOC in descending order in 1994 were CC (NT) ≥ WCF (NT) ≥ WF (NT) = WF (RT) = WF (CT) > WF (BF). Although not statistically significant, the CC (NT) treatment appeared to be accumulating more SOC than any of the rotations that included a fallow period, even more rapidly than WCF (NT), which had a similar amount of annualized C addition. Reduced tillage and intensified cropping increased SOC and reduced soil erosion potential.
Vicarious sampling: the use of personal and public information by starlings foraging in a simple patchy environment

Group foragers may be able to assess patch quality more efficiently by paying attention to the sampling activities of conspecifics foraging in the same patch. In a previous field experiment, we showed that starlings foraging on patches of hidden food could use the successful foraging activities of others to help them assess patch quality. In order to determine whether a starling could also use another individual’s lack of foraging success to assess and depart from empty patches more quickly, we carried out two experimental studies which compared the behaviour of captive starlings sampling artificial patches both when alone and when in pairs. Solitary starlings were first trained to assess patch quality in our experimental two-patch system, and were then tested on an empty patch both alone and with two types of partner bird. One partner sampled very few holes and thus provided a low amount of public information; the other sampled numerous holes and thus provided a high amount of public information. In experiment 1, we found no evidence of vicarious sampling. Subjects sampled a similar number of empty holes when alone as when with the low and high information partners; thus they continued to rely on their own personal information to make their patch departure decisions. In experiment 2, we modified the experimental patches, increasing the ease with which a bird could watch another’s sampling activities, and increasing the difficulty of acquiring accurate personal sampling information. This time, subjects apparently did use public information, sampling fewer empty holes before departure when with the high-information partner than when with the low-information partner, and sampling fewer holes when with the low-information partner than when alone. We suggest that the degree to which personal and public information are used is likely to depend both on a forager’s ability to remember where it has already sampled and on the type of environment in which foraging takes place.
Spectral and Kinetic Characterization of Visual Pigment Photointermediates

The literature describing intermediates formed after photolysis of visual pigments is reviewed. Results obtained near physiological temperatures using time-resolved optical density measurements in the UV/Vis region are emphasized. The general character of intermediates which appear in the course of protein function, and the role of methods with different time resolutions in their study, are discussed. Specific results for intermediates from bathorhodopsin to metarhodopsin II are treated in detail, with limited discussion of the earlier and later species. The discussion centers on the best-understood pigment, bovine rhodopsin, but results for cone-type and invertebrate pigments are also discussed. Comparison is made between the picture of the intermediates obtained using low-temperature trapping methods and that obtained using kinetic measurements. The thermodynamic parameters of the intermediates are discussed, and their significance for the structure/function of heptahelical protein intermediates in general is considered.
Information from fold shapes

Abstract Folds contain information about the deformation rocks have undergone and the condition of the rocks during deformation. How much of this can we decipher? The geometrical characteristics of folds and the strain distribution within them are perhaps the key to unlocking this information. If the folded layers were originally planar, they reflect inhomogeneous deformation, but without additional originally planar or linear markers of other orientations, we cannot determine the state of strain. The strain in a parallel fold, for example, can be accommodated either by flexural slip or by tangential longitudinal strain, two quite different but geologically realistic strain distributions among an infinite number of possible ones. There are some constraints imposed by fold shapes on possible strain distributions. Fold asymmetry reflects, in most circumstances, sense of shear strain parallel to the general orientation of the folded layering. Problems may arise in shear zones with large strains and in foliated rocks in which kink bands develop at small strains. Information on the orientations of principal stresses cannot be obtained from folds, unless the strain is small and the mechanism of folding understood, as for kink bands, or unless the bulk flow is of constant vorticity, which is difficult to demonstrate. The distribution of measured values of wavelength/thickness in a population of single-layer folds, together with measures of strain and estimates of amplification, can be used to estimate the viscosity ratio of the stiff layer to its matrix and the degree of non-linearity in the flow law, if effective power-law flow is assumed. Information on the rheological state of rocks at the time of folding can also be obtained from the pattern of curvature variation in individual single-layer folds, as demonstrated by the use of computer simulations of folding. Where applied, such methods indicate that the slow natural flow of rock involved in folding is mostly consistent with non-linear power-law rheology, as expected from the results of experimental rock deformation involving crystal-plastic deformation mechanisms.
The role of peroxiredoxin II in chemoresistance of breast cancer cells

Peroxiredoxin (Prx)II belongs to a family of redox-active proteins that use redox-sensitive cysteine in the active site to reduce peroxides. PrxII is induced by various oxidative stimuli and plays an important protective role against oxidative radical damage by reactive oxygen species. PrxII expression levels are correlated with resistance to radiation therapy or certain anti-cancer drugs in radioresistant breast cancer cells, glioblastomas, and head and neck cancer cells as well as in tissue isolated from head and neck patients who do not respond to radiation therapy. Small interfering RNA (siRNA) that inhibits the PrxII gene expression has been shown to partially reverse the radioresistant phenotype in radiation resistant breast cancer cells and sensitizes glioma cells to oxidative stress, highlighting the potential clinical importance of PrxII in radiation resistance in cancer. This article focuses on the role that PrxII may play in chemoresistant breast cancer cells.
Flotation chemistry of hematite/oleate system

Abstract Oleate flotation characteristics of hematite have been investigated in this study under a wide range of experimental conditions of pH, temperature, ionic strength and collector concentration. The study revealed the following major features of this system which include: (a) a maximum in floatability in the neutral pH range; (b) an increase in the flotation response of hematite with increase either in solution ionic strength at room temperature or in temperature at low ionic strengths; (c) marked temperature—ionic strength interactions yielding an inversion of the above effect under elevated temperature and high ionic strength conditions. None of these features can be satisfactorily explained by classical theories of collector adsorption based on electrostatic or chemisorption model. In this paper, the flotation results are explained taking the adsorption kinetics and the solution chemistry of the oleate into consideration. It is shown that the unique solubility characteristics of oleate, together with its tendency to form ionomolecular complexes, is largely responsible for the observed complex flotation behavior.
THE INFLUENCE OF DIETHYL STILBESTROL ON THE SPONTANEOUS ACTIVITY OF MALE RATS

As PREVIOUSLY REPORTED (1,2) we have underway at the Harvard Medical School and at the Worcester State Hospital a study of factors which influence the level of spontaneous activity in elderly rats. The activity is determined by the number of turns recorded by self–registering revolving cages. A considerable number of endocrine products and vitamin concentrates have so far failed to show any consistent influence upon the activity levels. Among these non–effective materials were desiccated thyroid (confirming previous work, 3) and testosterone propionate (1). The administration of estriol glucuronide (emmenin) on the other hand, resulted in fairly marked augmentation of the activity levels (2). A second estrogen, the synthetic substance, diethyl stilbestrol, has more recently been found likewise materially to increase the amount of activity. The rats used in the present study were males of an inbred Wistar albino strain. The age range was from 11 to 18 months (mature to elderly).
Increased Myocardial Tumor Necrosis Factor-α in a Crystalloid-Perfused Model of Cardiac Ischemia-Reperfusion Injury

Abstract Background . The heart is a tumor necrosis factor-α (TNF-α)–producing organ. Recent basic experimental and clinical evidence suggests that TNF-α is an important mediator of myocardial injury during acute myocardial infarction, chronic heart failure, cardiac allograft rejection, and cardiopulmonary bypass operations. Although it is known that the myocardium itself is capable of producing TNF-α in response to endotoxin, it is unknown whether there is an increase in myocardial tissue TNF-α levels after ischemia-reperfusion injury. We hypothesized that ischemia-reperfusion induces the production of TNF-α by the heart. Methods . To avoid blood-borne TNF-α as a potentially confounding variable, we examined myocardial TNF-α production in a crystalloid-perfused model of cardiac ischemia-reperfusion injury. Isolated rat hearts were perfused with crystalloid solution and subjected to ischemia-reperfusion. Postischemic myocardial TNF-α was measured using an enzyme-linked immunosorbent assay and correlated with developed pressure, coronary flow, end-diastolic pressure, and creatine kinase loss (assay of activity in coronary effluent). Results . Ischemia-reperfusion induced a marked increase in myocardial TNF-α that was associated with decreased myocardial contractility and coronary flow and with increased end-diastolic pressure and postischemic creatine kinase loss. Conclusions . The heart produces TNF-α in response to ischemia-reperfusion. Ischemia-induced TNF-α production may contribute to postischemic myocardial stunning, necrosis, or both. Strategies designed to limit ischemia-induced myocardial TNF-α production may have therapeutic utility in the settings of planned myocardial ischemic events.
Fluoroscopy-guided percutaneous transperitoneal fine needle biopsy of renal masses

Percutaneous transperitoneal fine needle biopsy is a harmless, easy to perform, and most direct procedure used to diagnose uncertain causes of ureteral obstruction and displacement of various parts of the urinary tract system. Frequently it is the least invasive method that can decide further treatment.
Adult Ixodes dammini on Rabbits: A Hypothesis for the Development and Transmission of Borrelia burgdorferi

A histological study of unfed Ixodes dammini adults has shown that the Lyme disease spirochete can be found in the midgut diverticula of these ticks and is presumably carried over from the nymphal stage. Sequential histology of the early stages of ticks feeding on a rabbit showed that spirochetes began to divide and were located in close proximity or attached to the epithelial cells of the diverticulae. Evidence for division was obtained by the higher number of spirochetes per tick after a three-day feeding period than in the unfed females. Although the mechanism is unclear, some spirochetes become systemic by the fifth day of feeding and can be detected in low numbers in other tick organs. Spirochetes were also noted in the feeding cavities created by I. dammini in the dermis after five days of attachment. Spirochetes were not detected in salivary glands or in the feces of I. dammini during the feeding period.
Comparison of different photobeam arrangements for measuring spontaneous activity of mice

Effects of chlorpromazine (1, 2, 4, 8 mg./Kg., p.o.) and aggregation (one or five animals) were tested on activity of mice in a circular photocell activity cage. The use of two right-angle (crisscross) beams yielded a better delineation of low drug doses than the use of three parallel beams. Fewer counts were recorded from the middle of three parallel beams than from the same beam in the crisscross arrangement, suggesting that the tendency of rodents to stay near the periphery was enhanced when the audible clicks of the counter were generated by interruptions of the peripheral beams. Both beam arrangements showed higher counts for aggregated than single animals and also showed a significant dose-aggregation interaction, with chlorpromazine decreasing activity of aggregated more than single animals. The findings indicate certain optimal conditions for testing the effects of chlorpromatine on activity.
Estimation of multicomponent polynomial phase signals of mixed orders

This paper addresses the issue of detection and parameter estimation of multicomponent polynomial phase signals (mc-PPS) embedded in noise. We focus on analyzing a general class of mc-PPS in the sense that we allow the PPS to have (i) very different amplitudes, (ii) unknown phase orders, and (iii) unknown number of components. We first show how existing techniques are inadequate in providing reliable estimates for such a broad class of mc-PPS. High-order ambiguity function (HAF) and its product multi-lag variant (PHAF) are the basic tools that we use here. The main contribution of this paper is that we present a recursive algorithm that always starts with the lowest order HAF (or PHAF) to successively detect, estimate, and remove the PPS components. This is contrasted with prevailing mc-PPS estimation techniques where the highest order HAF is first used and the PPS components are often assumed to have the same phase orders and like amplitudes. Computer simulations are carried out to illustrate the advantage of the proposed algorithm over existing techniques.
Geometric filter for speckle reduction.

An algorithm is described which reduces speckle noise in images. It is a nonlinear algorithm based on geometric concepts. Tests were performed on synthetic aperture radar images which show that it compares favorably with a 3 × 3 median filter.
Demographic and social constraints on male chimpanzee behaviour

Male chimpanzees, Pan troglodytes, are well known for affiliating and cooperating in a variety of behavioural contexts. Prior field research indicates that maternal kinship does not affect patterns of affiliation and cooperation by males in the same social group. Two questions remain unclear from this finding. First, why do male chimpanzees not bias their behaviour towards maternal kin? Second, what factors account for who affiliates and cooperates with whom? We conducted behavioural observations of an unusually large community of chimpanzees at Ngogo, Kibale National Park, Uganda, to test the hypothesis that demographic constraints limit the number of maternal kin with whom male chimpanzees can cooperate, and thereby lead them to form selective bonds with nonkin of similar age and status. Results indicated that male age and rank are significantly associated with four measures of social behaviour. Members of the same age class and individuals close in rank were more likely to affiliate and cooperate than males that belonged to different age and rank classes. Additional analyses replicate earlier findings and show that males who affiliated and cooperated were not closely related through the maternal line, as assayed by mtDNA haplotype sharing. These results add to our growing understanding of the important role demographic and social constraints play in animal behaviour.
Mechanisms Responsible for Adult Onset Decline in Food Intake and Body Weight gain due to Neonatal Neuropeptide Y Administration • 1582

Mechanisms Responsible for Adult Onset Decline in Food Intake and Body Weight gain due to Neonatal Neuropeptide Y Administration • 1582
Air-trench splitters for ultra-compact ring resonators in low refractive index contrast waveguides

We demonstrate air-trench splitters in low index contrast perfluorocyclobutyl (PFCB) waveguides. Splitters are fabricated by etching 800 nm wide high aspect ratio (18:1) trenches. The measured optical loss is 0.4 dB/splitter. The reflection/transmission splitting ratio is 0.859/0.141, which closely matches two-dimensional finite difference time domain (2D-FDTD) simulation results. Air-trench splitters and bends are used to demonstrate an ultra-compact ring resonator (RR) with a size reduction of 1,700 compared to a RR based on traditional curved waveguides in the same material system. A comparison between the RR’s measured and analytically calculated performance shows close agreement when splitter and bend losses are taken into account.
Hyperglycemic properties of serotonin receptor antagonists.

Abstract Several serotonin (5-HT) receptor antagonists with varying specificities for the 5-HT receptor types, were studied with regard to their effects on blood glucose levels in mice. The non-selective antagonists, metergoline and methysergide, proved to be hyperglycemic at doses commonly used to antagonize 5-HT receptors. In contrast, ritanserin (a 5-HT2 and 5-HT1c antagonist) and MDL 72222 (a 5-HT3 antagonist) were effective only at doses which surpassed the dose range considerd to be selective for their respective receptors. The results suggest that 5-HT systems play a role in maintaining glucose homeostasis and that 5-HT1 receptors may be particularly important in this function. Furthermore, the inherent hyperglycemic properties of non-selective serotonin antagonists described here, are pertinent to studies using these agents to investigate glucose metabolism.