522 resultados para 059999 Environmental Sciences not elsewhere classified


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We present a scheme to conditionally engineer an optical quantum system via continuous-variable measurements. This scheme yields high-fidelity squeezed single photons and a superposition of coherent states, from input single- and two-photon Fock states, respectively. The input Fock state is interacted with an ancilla squeezed vacuum state using a beam splitter. We transform the quantum system by postselecting on the continuous-observable measurement outcome of the ancilla state. We experimentally demonstrate the principles of this scheme using coherent states and experimentally measure fidelities that are only achievable using quantum resources.

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Two east - west transects were established in southern Queensland to quantify rainfall inputs of chloride and associated ions. Electrical conductivity, pH, and major and minor ions were measured at 9 sites within the Queensland Murray - Darling Basin and 1 site to the east. Variability at some sites was high, possibly a function of the sample collection method. Ionic concentrations decreased with distance inland, a trend similar to that observed elsewhere in Australia, although values closer to the coast were higher than observed in southern and western Australia. Equations to predict both annual average rainfall chloride mass deposition and total salt deposition were derived.

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Complement factor 5a (C5a) is formed upon complement system activation in response to infection, injury or disease. Whilst C5a is a potent mediator of immune and inflammatory processes, excessive production or inadequate regulation of C5a has been implicated in the pathogenesis of numerous immuno-inflammatory diseases, predominantly through experimental studies utilising animal models of disease. Both acute and chronic conditions may benefit from C5a inhibition, including rheumatoid arthritis, inflammatory bowel disease, asthma, psoriasis, haemorrhagic shock and neurodegenerative conditions. The potentially broad clinical application for treatments that inhibit the activity of C5a at C5a receptors and the large global market for anti-inflammatory therapeutics have made C5a and the C5a receptor attractive targets for academic and commercial drug development programmes. in the past 5 years, interest in C5a as a drug target has grown substantially, and this activity has resulted in a collection of patents and scientific papers reporting novel C5a and C5a receptor inhibitors and antagonists, and generated a secondary stream of patent applications broadly claiming the use of C5/C5a inhibitors as a method of treating various immune and inflammatory conditions. This paper will review the physiology and pathophysiology of C5a and discuss the development of C5a and C5a receptor inhibitors in light of the recent scientific and patent literature.

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Using an elementary example based on two simple harmonic oscillators, we show how a relational time may be defined that leads to an approximate Schrodinger dynamics for subsystems, with corrections leading to an intrinsic decoherence in the energy eigenstates of the subsystem.

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Background and Purpose. Arm lymphedema following breast cancer In this study, we assessed the surgery is a continuing problem. reliability and validity of circumferential measurements and water displacement for measuring upper-limb volume. Subjects. Participants included subjects who had had breast cancer surgery, including axillary dissection-19 with and 22 without a diagnosis of arm lymphedema-and 25 control subjects. Methods. Two raters measured each subject by using circumferential tape measurements at specified distances from the fingertips and in relation to anatornic landmarks and by using water displacement. Interrater reliability was calculated by analysis of variance and multilevel modeling. Volumes from circumferential measurements were compared with those from water displacement by use of means and correlation coefficients, respectively. The standard error of measurement, minimum detectable change (MDC), and limits of agreement (LOA) for volumes also were calculated. Results. Arm volumes obtained with these methods had high reliability. Compared with volumes from water displacement, volumes from circumferential measurements had high validity, although these volumes were slightly larger. Expected differences between subjects with and without clinical lymphedema following breast cancer were found. The MDC of volumes or the error associated with a single measure for data based oil anatomic landmarks was lower than that based oil distance from fingertips. The mean LOA with water displacement were lower for data based on anatomic landmarks than for data based on distance from fingertips. Discussion and Conclusion. Volumes calculated from anatomic landmarks are reliable, valid, and more accurate than those obtained from circumferential measurements based on distance from fingertips.

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Objective: Our aim was to determine if insomnia severity, dysfunctional beliefs about sleep, and depression predicted sleep-related safety behaviors. Method: Standard sleep-related measures (such as the Insomnia Severity Index; the Dysfunctional Beliefs About Sleep scale; the Depression, Anxiety, and Stress Scale; and the Sleep-Related Behaviors Questionnaire) were administered. Additionally, 14 days of sleep diary (Pittsburg Sleep Diary) data and actual use of sleep-related behaviors were collected. Results: Regression analysis revealed that dysfunctional beliefs about sleep predicted sleep-related safety behaviors. Insomnia severity did not predict sleep-related safety behaviors. Depression accounted for the greatest amount of unique variance in the prediction of safety behaviors, followed by dysfunctional beliefs. Exploratory analysis revealed that participants with higher levels of depression used more sleep-related behaviors and reported greater dysfunctional beliefs about their sleep. Conclusion: The findings underlie the significant influence that dysfunctional beliefs have on individuals' behaviors. Moreover, the results suggest that depression may need to be considered as an explicit component of cognitive-behavioral models of insomnia. (c) 2006 Elsevier Inc. All rights reserved.

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We study the electrical transport of a harmonically bound, single-molecule C-60 shuttle operating in the Coulomb blockade regime, i.e. single electron shuttling. In particular, we examine the dependance of the tunnel current on an ultra-small stationary force exerted on the shuttle. As an example, we consider the force exerted on an endohedral N@C-60 by the magnetic field gradient generated by a nearby nanomagnet. We derive a Hamiltonian for the full shuttle system which includes the metallic contacts, the spatially dependent tunnel couplings to the shuttle, the electronic and motional degrees of freedom of the shuttle itself and a coupling of the shuttle's motion to a phonon bath. We analyse the resulting quantum master equation and find that, due to the exponential dependence of the tunnel probability on the shuttle-contact separation, the current is highly sensitive to very small forces. In particular, we predict that the spin state of the endohedral electrons of N@C-60 in a large magnetic gradient field can be distinguished from the resulting current signals within a few tens of nanoseconds. This effect could prove useful for the detection of the endohedral spin-state of individual paramagnetic molecules such as N@C-60 and P@C-60, or the detection of very small static forces acting on a C-60 shuttle.

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Bistability arises within a wide range of biological systems from the A phage switch in bacteria to cellular signal transduction pathways in mammalian cells. Changes in regulatory mechanisms may result in genetic switching in a bistable system. Recently, more and more experimental evidence in the form of bimodal population distributions indicates that noise plays a very important role in the switching of bistable systems. Although deterministic models have been used for studying the existence of bistability properties under various system conditions, these models cannot realize cell-to-cell fluctuations in genetic switching. However, there is a lag in the development of stochastic models for studying the impact of noise in bistable systems because of the lack of detailed knowledge of biochemical reactions, kinetic rates, and molecular numbers. in this work, we develop a previously undescribed general technique for developing quantitative stochastic models for large-scale genetic regulatory networks by introducing Poisson random variables into deterministic models described by ordinary differential equations. Two stochastic models have been proposed for the genetic toggle switch interfaced with either the SOS signaling pathway or a quorum-sensing signaling pathway, and we have successfully realized experimental results showing bimodal population distributions. Because the introduced stochastic models are based on widely used ordinary differential equation models, the success of this work suggests that this approach is a very promising one for studying noise in large-scale genetic regulatory networks.

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We report on the observation of the excitation/ emission spectrum of a dendrimer-encapsulated gold nanocluster; the synthesis of Au-PAMAM was based on reduction of HAuCl4 center dot 3H(2)O co-dissolved in methanol together with fourth-generation OH-terminated PAMAM.

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PURPOSE. The driving environment is becoming increasingly complex, including both visual and auditory distractions within the in- vehicle and external driving environments. This study was designed to investigate the effect of visual and auditory distractions on a performance measure that has been shown to be related to driving safety, the useful field of view. METHODS. A laboratory study recorded the useful field of view in 28 young visually normal adults (mean 22.6 +/- 2.2 years). The useful field of view was measured in the presence and absence of visual distracters (of the same angular subtense as the target) and with three levels of auditory distraction (none, listening only, listening and responding). RESULTS. Central errors increased significantly (P < 0.05) in the presence of auditory but not visual distracters, while peripheral errors increased in the presence of both visual and auditory distracters. Peripheral errors increased with eccentricity and were greatest in the inferior region in the presence of distracters. CONCLUSIONS. Visual and auditory distracters reduce the extent of the useful field of view, and these effects are exacerbated in inferior and peripheral locations. This result has significant ramifications for road safety in an increasingly complex in-vehicle and driving environment.

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We report the use of an Internet-based videophone to support a child undergoing bone marrow transplantation (BMT). Over the Christmas period, an eight-year-old boy with an underlying diagnosis of attention-deficit/hyperactivity disorder (ADHD) and a history of absconding and aggressive non-compliant behaviour was treated by BMT. We installed an Internet-based videophone in the patient's hospital room two days post-transplant. A second videophone was installed in the patient's home and used the existing home telephone line. In all, 14 videophone calls were made over a nine-day period. The videophone improved interfamily social and emotional support, and appeared to reduce some of the inherent anxiety and distress resulting from paediatric bone marrow transplantation.

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Finite-element simulations are used to obtain many thousands of yield points for porous materials with arbitrary void-volume fractions with spherical voids arranged in simple cubic, body-centred cubic and face-centred cubic three-dimensional arrays. Multi-axial stress states are explored. We show that the data may be fitted by a yield function which is similar to the Gurson-Tvergaard-Needleman (GTN) form, but which also depends on the determinant of the stress tensor, and all additional parameters may be expressed in terms of standard GTN-like parameters. The dependence of these parameters on the void-volume fraction is found. (c) 2006 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

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Plastic yield criteria for porous ductile materials are explored numerically using the finite-element technique. The cases of spherical voids arranged in simple cubic, body-centred cubic and face-centred cubic arrays are investigated with void volume fractions ranging from 2 % through to the percolation limit (over 90 %). Arbitrary triaxial macroscopic stress states and two definitions of yield are explored. The numerical data demonstrates that the yield criteria depend linearly on the determinant of the macroscopic stress tensor for the case of simple-cubic and body-centred cubic arrays - in contrast to the famous Gurson-Tvergaard-Needleman (GTN) formula - while there is no such dependence for face-centred cubic arrays within the accuracy of the finite-element discretisation. The data are well fit by a simple extension of the GTN formula which is valid for all void volume fractions, with yield-function convexity constraining the form of the extension in terms of parameters in the original formula. Simple cubic structures are more resistant to shear, while body-centred and face-centred structures are more resistant to hydrostatic pressure. The two yield surfaces corresponding to the two definitions of yield are not related by a simple scaling.

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Telemedicine conducted via prerecorded interaction is more convenient than that using realtime interaction. On the other hand, a realtime consultation allows an immediate result to be obtained and there is likely to be a strong educational component for the remote practitioner. The use of the telephone is under-rated in telemedicine. Telephones have been used in outpatient follow-up, mental health, help lines and support groups. Telephones (fixed and mobile) have also been used for data transfer (e.g. for transmission of electrocardiograms). Realtime transfer of still images has been used in telepathology for many years, and more recently for rapid assessment of injuries. Realtime transfer of video images has been widely explored, perhaps most successfully in telepsychiatry. Some realtime telemedicine applications have been taken up with enthusiasm, even if formal evidence of cost-effectiveness may be lacking. Teleradiology and telepsychiatry are two examples where widespread adoption is beginning to occur. Other forms of realtime telemedicine represent 'niche' applications. That is, they appear to be both successful and sustainable in the centres where they were pioneered, but have not been adopted elsewhere. Teledialysis and teleoncology are examples of this type. The patchy diffusion of telemedicine is something that is not yet well understood.