Isotope variations in white-tailed kites from various habitats in California: possible limitations in assessing prey utilization and population dynamics

White-tailed kite (Elanus leucurus) populations in the 1930s were close to extirpation in the United States. But by the 1940s, an upward trend towards recovery was apparent and continued to their current stable population levels. These dramatic fluctuations in kite numbers may have been related to changes in rodent prey populations due to the conversion of native habitats to agriculture. To address this question, we evaluated the use of stable isotope analysis in determining if a shift in diet could be isotopically differentiated in current and historic kite populations. We first compared delta13C, delta15N, and delta34S values from present-day kite flight feathers and prey fur samples from four locations in California. The total ranges of isotope values for kite and their rodent prey were similar within each site. Carbon isotope values ranged from -27.1 to -22.2 per thousand in Arcata, -26.1 to -16.9 per thousand in Davis, -27.0 to -15.0 per thousand in Cosumnes, and -28.2 to -11.6 per thousand in Santa Barbara. Nitrogen isotope values ranged from 3.2 to 15.7 per thousand in Arcata, 2.8 to 12.7 per thousand in Davis, 4.0 to 15.7 per thousand in Cosumnes, and 1.7 to 20.0 per thousand in Santa Barbara. Sulfur isotope values ranged from -7.8 to 12.4 per thousand in Arcata, -1.1 to 9.2 per thousand in Davis, 0.7 to 10.9 per thousand in Cosumnes, and -8.6 to 15.6 per thousand in Santa Barbara. Carbon, nitrogen, and sulfur isotope values at each site reflect typical trophic enrichments due to physiological processes. At each site, delta13C and delta15N values reflected the influence of a predominantly C3 or a mixed C3/C4 plant community. Sulfur isotope values reflect the influence of predominant marine or terrestrial sulfur sources at each site. However, variability in isotope values may limit the usefulness of such analyses for addressing prey utilization and population dynamics.     

Parameters to Define the Electron Beam Trajectory of a Double-Tapered Disc-Loaded Wideband Gyro-TWT in Profiled Magnetic Field

In the method of tapering the cross section of the interaction structure for broadbanding a gyro-TWT, the different portions of the interaction length of the tapered-cross-section waveguide become effective for different frequency ranges if the magnetic field and beam parameters are profiled to maintain the condition of electron cyclotron resonance throughout the interaction length. In the present paper, the study of profiling the magnetic field and beam parameters in steps of the stepped analytical model of a double-tapered disc-loaded circular waveguide was made throughout the steps of the model. In the observed profile, the magnetic flux density in a typical step relative to its value in first-step decreases from first-step (gun-end) to end-step (collector-end) of the model considering the up-tapering schemes, in which structure parameters increase from gun-end to collector-end. Also, the transverse beam velocity in a typical step relative to its value in first-step decreases from gun-end to collector-end. However, the Larmor radius in a typical step relative to its value in first-step as well as the hollow-beam radius in a typical step relative to its value in first-step, both increase from gun-end to collector-end in the model considering the up-tapering schemes.     

Active noise control of a diesel generator in a luxury yacht

Active noise control has been applied to a variety of systems in order to improve performance without the increases in size and weight that would otherwise be required by traditional passive noise control treatments. This paper investigates the application of an active noise control system to the control of generator noise in the master cabin of a luxury yacht. A multichannel, multi-tonal active noise control system employing loudspeakers and microphones in the master cabin of the yacht is investigated. It is shown that, due to the high number of engine orders produced by the generator, in order to achieve significantly perceptible levels of noise attenuation it is necessary to control at least 7 individual orders. A controller is investigated which targets 19 engine orders and it is shown to achieve in excess of 5 dB broadband attenuation, whilst achieving up to 23 dB attenuation in individual orders. This corresponds to a 23% reduction in the Zwicker loudness.     

Quasi-pyroelectricity in the TGS crystal

It has been shown that a side electrode perpendicular to the measurement ones can significantly enhance the transverse electric current in TGS. Such a current, measured in a zero external electric field, resembles the classic longitudinal one. However, the amplitude of the transverse current oscillation, observed while cooling and heating the sample, rises much more slowly with the time of the transverse electric field preliminary application. Such exposure to the transverse field is required prior to the measurements for the transverse current to be observed, in a similar way to a longitudinal field that is applied in order to achieve a single domain state before longitudinal pyroelectric current measurements. A huge difference in the time of reaction to the electric fields preliminarily applied in order to achieve the maximum amplitude of the current oscillations in both cases is the evidence that the transverse current cannot be considered to be originated just for geometrical reasons.     

Ultrasonic wave propagation in heterogeneous solid media: theoretical analysis and experimental validation

This research deals with the ultrasonic characterization of thermal damage in concrete. This damage leads to the appearance of microcracks which then evolve in terms of volume rate and size in the material. The scattering of ultrasonic waves from the inclusions is present in this type of medium. The propagation of the longitudinal wave in the heterogeneous media is studied via a homogenization model that integrates the multiple scattering of waves. The model allows us to determine the phase velocity and the attenuation according to the elements which make the medium. Simulations adapted to the concrete are developed in order to test the responses of the model. These behaviors are validated by an experimental study: the measurements of phase velocity and attenuation are performed in immersion, with a comparison method, on a frequency domain which ranges from 160 kHz to 1.3 MHz. The analysis of different theoretical and experimental results obtained on cement-based media leads to the model validation, on the phase velocity behavior, in the case of a damage simulated by expanded polystyrene spheres in granular media. The application to the case of a thermally damaged concrete shows a good qualitative agreement for the changes in velocity and attenuation.     

Changes in ADC caused by tensile loading of rabbit achilles tendon: evidence for water transport

Water diffusion measurements were performed on rabbit Achilles tendons during static tensile loading and tendons in an unloaded state. The apparent diffusion coefficient (ADC) was measured along two directions: parallel and perpendicular to the long axis of the tendon. Tendons were studied after being prepared in two ways: (a) after being stored frozen in phosphate-buffered saline (PBS) and (b) freshly isolated. Statistically significant directional anisotropy was observed in the ADC in all tendons. The ADC was significantly greater in the direction parallel to the long axis of the tendon than in the perpendicular direction. The anisotropy is attributed to the greater restrictions seen by the water molecules in the perpendicular direction and is consistent with the known geometry of the tendon. Storage in PBS caused tendons to swell. This increased the ADC measured along both directions and reduced the anisotropy. The existence of anisotropy in the ADC was not related to the orientation of the specimen in the magnet. The ADC increased along both directions following the application of a 5-N tensile load; the increase was greatest along the perpendicular axis of the tendon. In order to determine whether load-related changes in the ADC reflected changes in interfibrilar spacing, we used electron microscopy to measure load-related changes in fibril spacing. Load-related changes in fiber spacing could not account for the observed changes in the ADC. The increase in ADC caused by loading was attributed to the extrusion of tendon water into a bulk phase along the outside surface of the tendon. In PBS-stored samples, enough fluid was extruded that it could be visualized. The transient response of the ADC to a 5-N tensile load was also studied. The absolute ADC in both directions increased with loading and recovered to baseline upon unloading. The transient changes in ADC, for both loading and unloading, had a mean time constant of approximately 15 min. The magnitude of the load-induced transient ADC changes was comparable to that seen in the static-loading experiments.     

Quantitative evaluation of the lung cancer deaths attributable to residential radon: A simple method and results for all the 21 Italian Regions

Pooled analyses of epidemiological case--control studies on lung cancer and residential radon have shown that radon exposure in dwellings increases lung cancer risk, and that the increase is statistically significant also for prolonged exposures to low-medium level of radon concentration, i.e. levels commonly found in many dwellings. In this paper, a simple method to evaluate the health burden due to the presence of radon in homes (i.e. the number of lung cancer deaths attributable to radon exposure in dwellings) was presented. This method is based on the following parameters: i) the excess relative risk per unit of exposure evaluated in case-control studies; ii) the average radon concentration that can be considered representative of population exposure in dwellings; iii) the total number of lung cancer deaths occurring each year. Moreover, the interaction between radon and cigarette smoking is needed to be taken into account: in fact, although most of the persons are non-smokers, most of the lung cancer deaths attributed to radon are actually due to the multiplicative effect of radon and cigarette smoking. To show this effect, the number of radon related lung cancer deaths estimated to occur among current, former and never smokers was calculated separately for males and females, taking into account the relative risk of lung cancer for the different smoking categories and the prevalence of smoking habits. The methodology described in this work was applied to all the 21 Italian Regions in order to illustrate it. The overall fraction of lung cancer deaths attributable to radon in Italy is about 10%, with values in individual Regions ranging from 4% to 16%. The greater part of the lung cancers attributable to radon is estimated to occur among current smokers for both males and females (72% and 60%, respectively, at national level). This is due to the synergistic effects of radon and cigarette smoking, which should therefore be taken into account in policies aimed to reduce the health burden from radon.     

1-苯胺基萘-8-磺酸盐在各种固体基质中发光特性的研究

1-苯胺基萘 - 8-磺酸盐 (ANS)在不同的固体基质中发光特性的研究发现 :(1 ) ANS分子发射峰位置与在甲醇溶液中相比 ,发生明显的蓝移 ,可能是由于约束在固体基质中的荧光分子的运动受到一定的限制而接近单分子发光的行为。与纯粉末 ANS荧光相比 ,发生红移。ANS在极性的滑石基质中 ,发射峰移向更短的波长 ,在非极性的石蜡基质中移向更长的波长 ,反映固体基质微观环境的变化。 (2 ) ANS分子荧光寿命明显缩短 ,主要原因是在固体基质中 ,荧光发射速率常数 kf 增大。 (3) ANS分子相对量子产率明显增大 ,荧光分子运动受限 ,减弱分子之间的相互作用 ,减小了由于碰撞引起的猝灭 ,分子结构刚性增强。该结果对于研究固体基质的物化性质、探讨光化学反应中能量转移现象具有重要意义。     

Noise emitted by water supply installations

This work deals with the problem of noise generated by water supply systems in homes. Measurements were made in situ to determine normal conditions of installations and noise levels generated in different rooms in the home. In order to determine the sources of noise and the best construction methods to minimise noise generation, a laboratory was also built to reproduce the conditions of this type of installation in homes. Tests were carried out in this laboratory on different configurations of type of tap, installation material, walling and fastening of the installation, to allow quantitative determination of the differences in noise generation between the various configurations used in households.     

Saxophonists tune vocal tract resonances in advanced performance techniques

The acoustical impedance spectrum was measured in the mouths of saxophonists while they played. During bugling and while playing in the very high or altissimo range, experienced players tune a strong, but relatively broad, peak in the tract impedance to select which peak in the bore impedance will determine the note. Less experienced players are unable to produce resonances with impedance peaks comparable in magnitude to those of the bore and consequently are unable to play these notes. Experienced players can also tune their tracts to select which combinations of notes are played simultaneously in multiphonics or chords, and to produce pitch bending, a technique in which notes are produced at frequencies far from those of the peak of impedance of the instrument bore. However, in normal playing in the standard range, there is no consistent tuning of the tract resonances. The playing frequency, in all cases, lies close to the peak in the impedance of the reed in parallel with the series combination of the impedances measured in the mouth and the instrument bore on either side of the reed (ZMouth+ZBore)∥ZReed.     

Magnetic resonance imaging of microstructure transition in stainless steel

Magnetic resonance images are prone to artifacts caused by metallic objects. Such artifacts may not only hamper image interpretation, but also have been shown to provide information about the magnetic properties of the substances involved. In this work, we aim to explore the potential of MRI to detect, localize and characterize changes in magnetic properties that may occur when certain alloys have been exposed to a thermomechanical stress. For this purpose, stainless steel 304 L wires were drawn to induce a change from paramagnetic austenitic into ferromagnetic martensitic microstructure. The changes in magnetic behavior were quantified by analyzing the geometric distortion in spin echo and the geometric distortion and intravoxel dephasing in gradient echo images at 0.5, 1.5 and 3 T. The results of both imaging strategies were in agreement and in accordance with independent measurements with a vibrating sample magnetometer. Drawing wire to 2% of its cross-sectional area was found to increase the volume fraction of the ferromagnetic martensite from 0.3% to 80% and to enhance the magnetization up to two or three orders of magnitude. The results demonstrate the potential of MRI to locate and quantify stress-induced changes in the magnetic properties of alloys in a completely noninvasive and nondestructive way.     

Controlling Surface Interactions with Grafted Polymers

The interactions between surfaces modified with grafted polymers is studied theoretically. The aim of this work is to find polymer surface modifications that will result in localized attractive interactions between the surfaces. The practical motivation of the work is to find means to control the distance between bilayers and solid supports in supported membranes. Two theoretical approaches are used, the analytical treatment of Alexander and a molecular theory. It is found that grafting each end of the polymer to each surface results in an interaction with a well defined minimum. The location of the minima is found to be very close to the thickness of the polymer layer when the chains are grafted to only one of the surfaces. The predictions of the analytical theory are in excellent agreement with the molecular approach in this case. It is found that increasing the surface coverage increases the strength of the interaction. However, increasing the polymer chain length at fixed surface coverage results in a decrease of the free energy cost associated with separating the surfaces from their optimal distance. For the cases in which grafting to both surfaces is not possible, the molecular theory is used to study the effect of functionalizing segments of the chain to achieve an attractive well. It is found that by functionalizing the free end-groups of the polymers with segments attracted to the membrane, the range of the attractive interaction is significantly larger than the thickness of the unperturbed layer. Functionlizing the middle segments of the chains results in a shorter range attraction but of the same strength as in the end-functionalized layers. The optimal polymer modification is found to be such that the functionlized groups are attracted to the bare surface but are not attracted to the grafting surface. The relevance of the results to the design of experimental surface modifiers is discussed.     

Attenuation of ultrasound in homogenates of bovine skeletal muscle and other tissues

The attenuation of ultrasound in homogenates of bovine skeletal muscle and suspensions of myofibrils was measured over the frequency range 1.5-7 MHz, and found to be proportional to protein concentration in both. In the homogenates it varied with frequency and temperature in a similar way to the attenuation in post rigor muscle tissue; myofibrils showed a higher frequency dependence. The attenuation in homogenates of bovine muscle, liver and kidney and in suspensions of myofibrils was measured over the pH range 3.5-13, and each showed a peak at about pH 11.5. This was thought to be due to a proton transfer process between NH3+ groups on the tissue proteins and OH- ions in the suspending fluid. A substantial peak at about pH 5 in the muscle and myofibril suspensions was not observed in homogenates of liver and kidney and was thought to be due to components of muscle that are absent from the other tissues. Myofibrils suspended in percoll solution of density 1.05 g cm-3, chosen to match approximately the density of the myofibrils, showed a slightly lower attenuation over the pH range 5-7, but a pH dependence similar to that of the myofibrils suspended in saline. The difference in the attenuations may be interpreted as the viscous component of the attenuation due to relative motion between the myofibril and its surrounding saline. The peak at pH 5 did not, however, appear to be due to the viscous loss mechanism peaking due to maximum shrinkage (and therefore maximum density) of the myofibril near this pH.(ABSTRACT TRUNCATED AT 250 WORDS)     

Analyzing and correcting spectrometer temperature sensitivity

Stability and reproducibility of the spectrometer are fundamental to the success of many modern NMR experiments. Variation in room temperature is a particularly important source of instability, in part because it can cause coherent artifacts in NMR spectra. Small changes in room temperature lead to corresponding changes in the phases, amplitudes, and frequencies of NMR signals. These can lead in turn to apparently random spectral artifacts such as t(1)-noise in two-dimensional (2D) NMR and to the incomplete cancellation of signals in difference spectra, but also, importantly, to F(1) satellite signals in 2D spectra. These "parallel diagonals" arise from the use of air conditioning, which typically forces room temperature to oscillate within a fixed band. Work to identify, quantify, and suppress sources of temperature sensitivity in a modern 300-MHz spectrometer has led to a greater than 10-fold improvement in the signal-to-artifact ratio.     

The effect of sound level on perception of reproduced soundscapes

The aim of this work was to investigate the perception of soundscape reproduced by an ambisonic reproduction system on a horizontal plane, how the experience of space affected the perception of soundscape reproduction, and how the sound level adjustment on soundscape reproduction affected the perception of soundscape compared with actual conditions. There were three experiments conducted: a soundwalk in situ in Manchester (United Kingdom) city centre, listening tests in Salford (United Kingdom), and listening tests in Bandung (Indonesia). The listening tests used material recorded from four locations on the soundwalk route in Manchester. The Salford listening tests were performed at the in-situ measured sound level, and the participants were asked to adjust the sound level to the level that represents actual locations. The listening test in Bandung was conducted to understand the effect of participants who never come to the actual location to the perception of soundscape and the sound level adjustment. The listening tests in Bandung were conducted at the in situ sound level, at 9.5 dB below the in situ sound level (based on the preference sound level from the experiment in Salford), and the participants were also requested to adjust the sound level to the level that represents the actual space (to examine the consistency with the experiment in Salford). In each case, soundscape perception was measured on 19 semantic differential scales. Analysis of the semantic differential results showed that the ambisonic reproduction produced a similar subjective experience to the in situ soundwalk when the reproduction sound level was 9.5 dB lower than the actual sound level in situ. Reproduction at the actual sound level in situ produced a different dimensional space. The study shows that the sound level adjustment of soundscape reproduction in laboratory experiment produces more ecologically valid results compared to the reproduction at the actual sound level in situ.     

From the inverted pendulum to the periodic interface modes

The physics of the spatial propagation of monochromatic waves in periodic media is related to the temporal evolution of the parametric oscillators. We transpose the possibility that a parametric pendulum oscillates in the vicinity of its unstable equilibrium position to the case of monochromatic waves in a lossless unidimensional periodic medium. We develop this concept, that can formally applies to any kind of waves, to the case of longitudinal elastic wave. Our analysis yields us to study the propagation of monochromatic waves in a periodic structure involving two main periods. We evidence a class of phonons we refer to as periodic interface modes that propagate in these structures. These modes are similar to the optical Tamm states exhibited in photonic crystals. Our analysis is based on both a formal and an analytical approach. The application of the concept to the case of phonons in an experimentally realizable structure is given. We finally show how to control the frequencies of these phonons from the engineering of the periodic structure.     

Hair cycle and hair pigmentation: dynamic interactions and changes associated with aging

The tight coupling of hair follicle melanogenesis to the hair growth cycle dramatically distinguishes follicular melanogenesis from the continuous melanogenesis of the epidermis. Cyclic re-construction of an intact hair follicle pigmentary unit occurs optimally in all scalp hair follicles during only the first 10 hair cycles, i.e. by approximately 40 years of age. Thereafter there appears to be a genetically regulated exhaustion of the pigmentary potential of each individual hair follicle leading to the formation of true gray and white hair. Pigment dilution results primarily from a reduction in tyrosinase activity within hair bulbar melanocytes. Thereafter, sub-optimal melanocyte-cortical keratinocyte interactions, and defective migration of melanocytes from a reservoir in the upper outer root sheath to the pigment-permitting microenvironment close to the follicular papilla of the hair bulb, will all disrupt normal function of the pigmentary unit. Evidence from studies on epidermal melanocyte aging suggest that reactive oxygen species-mediated damage to nuclear and mitochondrial DNA may lead to mutation accumulation in bulbar melanocytes. Parallel dysregulation of anti-oxidant mechanisms or pro/anti-apoptotic factors is also likely to occur within the cells. Pigment loss in canities may also affect keratinocyte proliferation and differentiation, providing the tantalizing suggestion that melanocytes in the hair follicle contribute far more that packages of pigment alone. Here, we review the current state of knowledge of the development, regulation and control of the aging human hair follicle pigmentary system in relation with hair cycling. The exploitation of recently available methodologies to manipulate hair follicle melanocytes in vitro, and the observations that melanocytes remain in senile white hair follicles that can be induced to pigment in culture, raises the possibility of someday reversing canities. The perspective of rejuvenation of the whole hair follicle apparatus are still part of the dream but optimising its functional properties is clinically relevant and is close to reality. Finally as hair color influences its visibility when optical methods such as scalp photography are used to count hair fibers, the attention is drawn to possible interpretations of statistically significant changes in visible hair. Such changes may not exclusively be related to improved hair growth itself but also to changes in natural hair color that makes the hair more visible with the method used to count hairs.     

Higher-Order Interference in Extensions of Quantum Theory

Quantum interference, manifest in the two slit experiment, lies at the heart of several quantum computational speed-ups and provides a striking example of a quantum phenomenon with no classical counterpart. An intriguing feature of quantum interference arises in a variant of the standard two slit experiment, in which there are three, rather than two, slits. The interference pattern in this set-up can be written in terms of the two and one slit patterns obtained by blocking one, or more, of the slits. This is in stark contrast with the standard two slit experiment, where the interference pattern cannot be written as a sum of the one slit patterns. This was first noted by Rafael Sorkin, who raised the question of why quantum theory only exhibits irreducible interference in the two slit experiment. One approach to this problem is to compare the predictions of quantum theory to those of operationally-defined ‘foil’ theories, in the hope of determining whether theories that do exhibit higher-order interference suffer from pathological—or at least undesirable—features. In this paper two proposed extensions of quantum theory are considered: the theory of Density Cubes proposed by Daki?, Paterek and Brukner, which has been shown to exhibit irreducible interference in the three slit set-up, and the Quartic Quantum Theory of ?yczkowski. The theory of Density Cubes will be shown to provide an advantage over quantum theory in a certain computational task and to posses a well-defined mechanism which leads to the emergence of quantum theory—analogous to the emergence of classical physics from quantum theory via decoherence. Despite this, the axioms used to define Density Cubes will be shown to be insufficient to uniquely characterise the theory. In comparison, Quartic Quantum Theory is a well-defined theory and we demonstrate that it exhibits irreducible interference to all orders. This feature of ?yczkowski’s theory is argued not to be a genuine phenomenon, but to arise from an ambiguity in the current definition of higher-order interference in operationally-defined theories. Thus, to begin to understand why quantum theory is limited to a certain kind of interference, a new definition of higher-order interference is needed that is applicable to, and makes good operational sense in, arbitrary operationally-defined theories.     

Glow discharge plasma electrolysis for nanoparticles synthesis

There are many methods available to synthesize nanomaterials and the glow discharge plasma electrolysis is a novel and a green method in this category. It is seen that most of the papers are published after 2005 and the interest in it is growing due to its applicability in the industry for preparing nanomaterials at large scale. But, only few results are available yet and most of them are on metal nanoparticle preparation, so that more studies are needed to understand the nature of growth of the nanoparticles under glow discharge in liquid and its applicability in preparing semi-conductor nanomaterials. Many have tried many methods to prepare nanoparticles by the glow discharge and a review like this is the need of the time to understand its present status that helps to modify the present situation to a better one. This review classifies all the available methods of nanomaterials synthesis in liquid by glow discharge in to three and it is discussed in detail.