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Conservative management (supportive care) is defined as individuals with advanced chronic kidney disease (CKD) who choose not to undergo dialysis (supported by their kidney team). A renal supportive care (SC) outpatient service has existed for over 10 years at this large renal unit. Dietetic management in this population is complex, with the aim being to alleviate and/or reduce the risk of symptoms associated with advanced CKD and support quality of life. This may involve dietetic interventions such as: management of blood biochemistry (potassium, phosphate and mineral bone disease), fluid status (no added salt), low protein and nutritional support. The aim is to evaluate current dietetic practice using a snapshot of the SC population The method used was a random sample of selected patients. Data collected included demographics, prevalence of abnormal blood results, low protein diet advice and nutritional support. The results for twenty patients (11% of the SC population) were used. Median age 80.5, range: 70 – 99years). Median duration under SC service: 23.5 (range: Eighteen patients (90%) had received dietetic input. Half of these patients (n=9) required a low protein diet and 33% (n=6) were given nutritional supplementation. Three patients (15%) had either a recent elevated blood potassium or phosphate level. In conclusion, the complexity of dietetic management in this SC patient population highlights the importance of a renal dietitian’s involvement to help alleviate symptoms of advanced CKD and support quality of life. Further research into outcomes including patient/carer experience surveys is warranted.

We would like to thank Dr Grosser et al1 for their continued interest in our work. While we may not agree with their arguments or their opinions of our study,2 we welcome debate in this extremely important area. We take this opportunity to address the points that they raise. First, although urine may well be a convenient compartment within which to measure markers of prostacyclin and thromboxane A2, numerous observations,3–10 of which ours is only the latest,2 indicate that they poorly reflect production within the circulation and the reactivities of endothelial cells and platelets. Second, the literature that Grosser et al1 cite is somewhat selective and in places inaccurate. For example, reference 3,11 which the authors cite to substantiate the statement “Most insights into the in vivo biology and pharmacology of the prostaglandin pathway have derived from the …

Chronic kidney disease (CKD) and acute kidney injury (AKI) are more common in the elderly due to ageing-related changes in the kidney. Renal pathology in the elderly will in future form an increasing proportion of the workload of nephrologists, specialists in internal medicine and general practitioners due to ageing of the general population. AKI in the elderly can often be anticipated and prevented. Published guidelines concerning the management of CKD in younger adults may not be universally implementable in the elderly, and may ignore complications and challenges specific to this age group. There is a growing demand for renal services to provide renal replacement therapy (RRT) to elderly patients. The decision to start an elderly person on a particular form of RRT should follow careful assessment of their biological age, function and lifestyle, and their health priorities and quality of life must be kept at the centre of decision-making at all times. Patients who are unsuited to or do not wish to commence RRT may do very well with maximal conservative management (MCM). End-of-life and palliative care remains somewhat underused in nephrology, and is an area that needs to be developed further.

The present status of the Linac Coherent Light Source as a user facility is presented. Opportunities and challenges as well as the scientific impact of X-ray free-electron lasers are discussed., The Linac Coherent Light Source (LCLS) at the SLAC National Accelerator Laboratory was the first hard X-ray free-electron laser (FEL) to operate as a user facility. After five years of operation, LCLS is now a mature FEL user facility. Our personal views about opportunities and challenges inherent to these unique light sources are discussed.

Elastic to Plastic When a crystal is mechanically compressed, it first reacts elastically (reversibly), and then enters the plastic regime, in which the structure of the material is irreversibly changed. This process can be studied with molecular dynamics (MD) simulations on very fine temporal and spatial scales, but experimental analysis has lagged behind. Milathianaki et al. (p. 220 ) shocked polycrystalline copper with a laser beam, and then took successive snapshots of the crystal structure at 10-picosecond intervals. The results were compared directly with atomistic simulations and revealed that the yield stress—the point of transition from plastic to elastic response—agreed well with MD predictions.

Measuring neuron capacitance is important for morphological description, conductance characterization, and neuron modeling. One method to estimate capacitance is to inject current pulses into a neuron and fit the resulting changes in membrane potential with multiple exponentials; if the neuron is purely passive, the amplitude and time constant of the slowest exponential give neuron capacitance (Major G, Evans JD, Jack JJ. Biophys J 65: 423–449, 1993). Golowasch et al. (Golowasch J, Thomas G, Taylor AL, Patel A, Pineda A, Khalil C, Nadim F. J Neurophysiol 102: 2161–2175, 2009) have shown that this is the best method for measuring the capacitance of nonisopotential (i.e., most) neurons. However, prior work has not tested for, or examined how much error would be introduced by, slow voltage-dependent phenomena possibly present at the membrane potentials typically used in such work. We investigated this issue in lobster ( Panulirus interruptus) stomatogastric neurons by performing current clamp-based capacitance measurements at multiple membrane potentials. A slow, voltage-dependent phenomenon consistent with residual voltage-dependent conductances was present at all tested membrane potentials (−95 to −35 mV). This phenomenon was the slowest component of the neuron's voltage response, and failure to recognize and exclude it would lead to capacitance overestimates of several hundredfold. Most methods of estimating capacitance depend on the absence of voltage-dependent phenomena. Our demonstration that such phenomena make nonnegligible contributions to neuron responses even at well-hyperpolarized membrane potentials highlights the critical importance of checking for such phenomena in all work measuring neuron capacitance. We show here how to identify such phenomena and minimize their contaminating influence.

Characterizing muscle requires measuring such properties as force---length, force---activation, and force---velocity curves. These characterizations require large numbers of data points because both what type of function (e.g., linear, exponential, hyperbolic) best represents each property, and the values of the parameters in the relevant equations, need to be determined. Only a few properties are therefore generally measured in experiments on any one muscle, and complete characterizations are obtained by averaging data across a large number of muscles. Such averaging approaches can work well for muscles that are similar across individuals. However, considerable evidence indicates that large inter-individual variation exists, at least for some muscles. This variation poses difficulties for across-animal averaging approaches. Methods to fully describe all muscle's characteristics in experiments on individual muscles would therefore be useful. Prior work in stick insect extensor muscle has identified what functions describe each of this muscle's properties and shown that these equations apply across animals. Characterizing these muscles on an individual-by-individual basis therefore requires determining only the values of the parameters in these equations, not equation form. We present here techniques that allow determining all these parameter values in experiments on single muscles. This technique will allow us to compare parameter variation across individuals and to model muscles individually. Similar experiments can likely be performed on single muscles in other systems. This approach may thus provide a widely applicable method for characterizing and modeling muscles from single experiments.

An electrospun liquid microjet has been developed that delivers protein microcrystal suspensions at flow rates of 0.14–3.1 µl min−1to perform serial femtosecond crystallography (SFX) studies with X-ray lasers. Thermolysin microcrystals flowed at 0.17 µl min−1and diffracted to beyond 4 Å resolution, producing 14 000 indexable diffraction patterns, or four per second, from 140 µg of protein. Nanoflow electrospinning extends SFX to biological samples that necessitate minimal sample consumption.

The Linac Coherent Light Source free-electron laser has now achieved coherent X-ray generation down to a wavelength of 1.2 A and at a brightness that is nearly ten orders of magnitude higher than conventional synchrotrons. Researchers detail the first operation and beam characteristics of the system, which give hope for imaging at atomic spatial and temporal scales.

The pyloric network of decapod crustaceans has been intensively studied electrophysiologically in the infraorders Astacidea, Brachyura, and Palinura. The morphology of some or all pyloric neurons has been well described in Astacidea and Brachyura, but less so in Palinura. Given the large evolutionary distance between these three groups, and the large amount of electrophysiology that has been performed in palinuroid species, it is important to fill this gap. We describe here the gross morphology of all six pyloric neuron types in a palinuroid, P. interruptus. All pyloric neurons had complicated, extended dendritic trees that filled the majority of the neuropil, with most small diameter processes present in a shell near the surface of the ganglion. Certain neuron types showed modest preferences for somata location in the ganglion, but these differences were too weak to use as identifying characteristics. Quantitative measurements of secondary branch number, maximum branch order, total process length, and neuron somata diameter were also, in general, insufficient to distinguish among the neurons, although AB and LP neuron somata diameters differed from those of the other types. One neuron type (VD) had a distinctive neurite branching pattern consisting of a small initial branch followed shortly by a bifurcation of the main neurite. The processes arising from these two branches occupied largely non-overlapping neuropil. Electrophysiological recordings showed that each major branch had its own spike initiation zone and that, although the zones fired correlated spikes, they generated spikes independently. VD neurons in the other infraorders have similar morphologies, suggesting that having two arbors is important for the function of this neuron. These data are similar to those previously obtained in Brachyura and Astacidea. It thus appears that, despite their long evolutionary separation, neuron morphology in these three infraorders has not greatly diverged.

(2007). The Idea of America: A Case Study Approach. The Social Studies: Vol. 98, No. 6, pp. 242-250.

Ab initio calculations were performed on 18 fluorinated and unfluorinated alcohols at the B3LYP and HF levels with the 6-311G∗∗ basis set. Molar volumes of the alcohols were computed at each level and averaged to produce a scale of relative size. From this, various isosteric replacements of potential use in drug design were suggested: ethyl by FCH2CH2 or HCF2CH2, propyl by CF3CH2, isopropyl by CF3(CH3)CH or (FCH2)2CH, isobutyl or t-butyl by (CF3)2CH, and 3-methyl-2-butyl by CF3(CH3)2C. Calculation of the charge on oxygen and the Wiberg index of the CO bond allowed an electronegativity scale to be constructed for the fluoroalkyl groups. Electronegativity decreased in the order: (CF3)3C>(CF3)2CH>C2F5CH2>CF3CH2>CH3(CF3)2C>HCF2CH2>CF3(CH3)CH>(FCH2)2CH>FCH2CH2>CF3(CH3)2C. This ranking agreed with literature acid dissociation data for the alcohols studied.

This manuscript serves as a reference to describe the optical laser sources and capabilities at the Linac Coherent Light Source., Ultrafast optical lasers play an essential role in exploiting the unique capabilities of recently commissioned X-ray free-electron laser facilities such as the Linac Coherent Light Source (LCLS). Pump–probe experimental techniques reveal ultrafast dynamics in atomic and molecular processes and reveal new insights in chemistry, biology, material science and high-energy-density physics. This manuscript describes the laser systems and experimental methods that enable cutting-edge optical laser/X-ray pump–probe experiments to be performed at LCLS.

International audience; The advent of few femtosecond x-ray light sources brings promise of x-ray/optical pump-probe experiments that can measure chemical and structural changes in the 10-100 fs time regime. Widely distributed timing systems used at x-ray Free-Electron Laser facilities are typically limited to above 50 fs fwhm jitter in active x-ray/optical synchronization. The approach of single-shot timing measurements is used to sort results in the event processing stage. This has seen wide use to accommodate the insufficient precision of active stabilization schemes. In this article, we review the current technique for "measure-and-sort" at the Linac Coherent Light Source at the SLAC National Accelerator Laboratory. The relative arrival time between an x-ray pulse and an optical pulse is measured near the experimental interaction region as a spectrally encoded cross-correlation signal. The cross-correlation provides a time-stamp for filter-and-sort algorithms used for real-time sorting. Sub-10 fs rms resolution is common in this technique, placing timing precision at the same scale as the duration of the shortest achievable x-ray pulses.

The reactions of thiirane with ammonia, a series of primary amines and aniline have been studied by means of ab initio Hartree-Fock calculations at the 6-31G* level. The transition state geometries were characterized and used to determine the relative rates of reaction. In all cases, anti attack by the nucleophile was favored. Relative rates for the aliphatic amines varied by a factor of less than twenty, with ethylamine being most reactive. Ammonia reacted more than twenty and aniline almost 8 x 10 4 times slower than tert-butylamine. The results can be rationalized on the basis of relative nucleophilicity and nonbonding interactions.

Collision-induced dissociation of metal-cationized N-CBZ-Gly-Pro-Gly-Pro-Ala was studied by Fourier transform mass spectrometry. Lithium-, sodium-, potassium- and rubidium-cationized peptide species were generated by matrix-assisted laser desorption/ionization (MALDI) using 2,5-dihydroxybenzoic acid as matrix, together with appropriate metal salts. The experimental mass spectrometric results were interpreted with the aid of Monte Carlo conformational searches using the Amber * force field, together with ab initio molecular orbital calculations with Gaussian-94 for the singly lithium- and potassium-cationized peptides. It is concluded that metal coordination plays a key role in guiding the gas-phase fragmentation of the cationized peptide. In contrast to lithium and sodium, potassium and rubidium apparently do not coordinate to the C-terminal carbonyl. When the peptide is cationized with the two smaller alkali metals, losses corresponding to alanine and CBZ are observed, while the coordination of potassium and rubidium results in only CBZ loss upon dissociation.

The hydrolysis of phosphorus fluoridates was studied by semiempirical and ab initio methods. The reaction proceeds through a metastable intermediate separated from the reactants and products by transition structures. Both methods gave similar qualitative results; however, the first transition (formation of the trigonal bipyrimid intermediate) occurred earlier and the second (loss of F-) later with semiempirical methods. Including solvation in the calculations is critical. The AMSOL program generated reasonable energies especially when the limitations of the semiempirical Hamiltonian are considered. The Onsanger model was not a significant improvement over calculations on isolated molecules.

A neutral gas phase reaction pathway for the reaction of methanol with dimethylphosphinic fluoride is presented. This reaction pathway occurs via a proton transfer from methanol to the fluorine leaving group through the phosphinyl oxygen. Gas phase ab initio level calculations at the RHF/6-31G(d), RHF/6-31G(d,p), B3LYP/6-31+G(2d), and B3LYP/6-311++G(2d,p) level of theories were used to follow the complete pathway for this reaction. A 41.2 and a 30.9 kcal/mol gas phase energy barrier was determined for both the RHF/6-31G(d,p) and B3LYP/6-311++G(2d,p) levels of theory, respectively.

We report experimental results of x-ray amplification of spontaneous emission in a Ni-like transient collisional excitation scheme. The Ni-like plasma formation, ionization, and collisional excitation requires irradiation of a slab target by two laser pulses: a formation beam with 5J energy of 800ps duration and a pump beam of 5J energy in 1.1ps. A gain of 35 cm{sup {minus}1} and a gL product of 12.5 are measured on the 4d{r_arrow}4p J=0{r_arrow}1 transition for Ni-like Pd at 147{Angstrom} with an 8mm line focus. The high efficiency of this scheme at {open_quotes}table-top{close_quotes} laser energies is a direct consequence of the nonstationary population inversion produced by the high intensity picosecond pulse. {copyright} {ital 1998} {ital The American Physical Society}

This study examines the equity consequence of school finance policy changes in Kentucky. It incorporates traditional school finance concerns regarding equity targets, objects, principles, and statistics. It utilizes adjustments for district economies of scale and interdistrict price differences. Findings indicate that Kentucky experienced marked improvements in equity as a result of school finance reform, including a narrower dispersion of pupil revenue and greater fiscal neutrality. Equity improvements resulted from policy changes that effectively addressed disequalizing attributes of the pre-reform state aid formula. Manipulating this formula further could produce additional marginal gains in system equity but at substantial cost.

One Protein, Two Probes A central challenge in the use of x-ray diffraction to characterize macromolecular structure is the propensity of the high-energy radiation to damage the sample during data collection. Recently, a powerful accelerator-based, ultrafast x-ray laser source has been used to determine the geometric structures of small protein crystals too fragile for conventional diffraction techniques. Kern et al. (p. 491 , published online 14 February) now pair this method with concurrent x-ray emission spectroscopy to probe electronic structure, as well as geometry, and were able to characterize the metal oxidation states in the oxygen-evolving complex within photosystem II crystals, while simultaneously verifying the surrounding protein structure.

We present a new method for probing photoexcited molecular dynamics based on the site selective ionization via ultrafast x-rays followed by Auger decay.

A PM3 and SM3-PM3 semiempirical molecular orbital study of the 2,2′-dichlorodiethyl sulfide conventional S N 2 and neighboring group hydrolysis reaction mechanisms in the gas phase and in aqueous solution is described. The calculations predict substantially faster reactions in aqueous solution, with the neighboring group mechanism always being preferred. Detailed consideration is given to the geometries, relative energies, and partial atomic charges of all species involved in the reaction mechanisms considered and the extent to which aqueous solvation impacts these quantities. The results are consistent with expectation and with reported calculations concerning the intramolecular S N 2 reaction of 2-chloroethyl methyl sulfide. We also present the lowest energy mustard chlorohydrin structures according to PM3 and AM1 conformational analysis.

The fully optimized structures and relative energies of all possible methoxy-1,3,5-cycloheptatriene (MCHT) isomers have been determined by semiempirical, ab initio, and density functional theory (DFT) molecular orbital calculations. All methods identify the boat conformation of 1-methoxy-1,3,5-cycloheptatriene as the most stable species in this group of compounds. In order to evaluate boat interconversion barriers, optimizations of the planar isomers were also performed. For comparison purposes, we applied the same computational methodologies to boat and planar conformations of 1,3,5-cycloheptatriene (CHT). Among the semiempirical methods, the SAM1 approximation was found to best reproduce the ab initio and DFT results. Examination of rotational energy profiles allowed for identification of the factors controlling the preferred orientations of the methoxy group in these compounds. The calculations predict that methoxy substitution has little influence on the preferred conformation of the seven-membered ri...

We report measurements of laser absorption for high-contrast ultrashort pulses on a variety of solid targets over an intensity range of ${10}^{13}$ to ${10}^{18}$ W/ ${\mathrm{cm}}^{2}$. These data give an experimental determination of the target energy content and an indirect measure of dense plasma electrical conductivity. Our calculations accurately reproduce the behavior of aluminum targets, while the other materials show signs of additional absorption mechanisms. At high intensity all target materials reach a ``universal plasma mirror'' state and reflect about 90% of the incident light.

The matter in extreme conditions end station at the Linac Coherent Light Source (LCLS) is a new tool enabling accurate pump-probe measurements for studying the physical properties of matter in the high-energy density (HED) physics regime. This instrument combines the world's brightest x-ray source, the LCLS x-ray beam, with high-power lasers consisting of two nanosecond Nd:glass laser beams and one short-pulse Ti:sapphire laser. These lasers produce short-lived states of matter with high pressures, high temperatures or high densities with properties that are important for applications in nuclear fusion research, laboratory astrophysics and the development of intense radiation sources. In the first experiments, we have performed highly accurate x-ray diffraction and x-ray Thomson scattering measurements on shock-compressed matter resolving the transition from compressed solid matter to a co-existence regime and into the warm dense matter state. These complex charged-particle systems are dominated by strong correlations and quantum effects. They exist in planetary interiors and laboratory experiments, e.g., during high-power laser interactions with solids or the compression phase of inertial confinement fusion implosions. Applying record peak brightness x-rays resolves the ionic interactions at atomic (Angstrom) scale lengths and measure the static structure factor, which is a key quantity for determining equation of state data and important transport coefficients. Simultaneously, spectrally resolved measurements of plasmon features provide dynamic structure factor information that yield temperature and density with unprecedented precision at micron-scale resolution in dynamic compression experiments. These studies have demonstrated our ability to measure fundamental thermodynamic properties that determine the state of matter in the HED physics regime.

A recently demonstrated single-shot measurement of the relative delay between x-ray FEL pulses and optical laser pulses has now been improved to ~10 fs rms error and has successfully been demonstrated for both soft and hard x-ray pulses. It is based on x-ray induced step-like reduction in optical transmissivity of a semiconductor membrane (Si 3 N 4 ). The transmissivity is probed by an optical continuum spanning 450 - 650 nm where spectral chirp provides a mapping of the step in spectrum to the arrival time of the x-ray pulse relative to the optical laser system.

We present our first results of a UV-pump X-ray-probe study of the photoprotection mechanism of thymine. The experiment used element specific Auger spectroscopy and was carried out at the LCLS.

The K -shell emission from porous aluminum targets is used to infer the density and temperature of plasmas created with 800 and 400 nm, 140 fsec laser light. The laser beam is focused to a minimum spot size of 5 μm with 800 nm light and 3 μm with 400 nm light, producing a normal incidence peak intensity of 10 18 W/cm 2 . The effects of design, laser characteristics, and diagnostic needs is discussed.

The use of high intensity ultrashort laser pulses in the study of hot, high density plasmas requires pulses of extreme temporal fidelity. We have developed a system that provides continuously variable independent tuning of the higher order frequency dependent phase of ultrashort laser pulses. Numerical results are presented indicating that higher order phase terms that lead to temporal wings can be compensated by a properly adjusted air spaced doublet lens within the pulse stretcher.

Pyroelectric linear arrays can be used to generate profiles of targets. Simulations have shown that generated profiles can be used to classify human and animal targets. A pyroelectric array system was used to collect data and classify targets as either human or non-human in real time. The pyroelectric array system consists of a 128-element Dias 128LTI pyroelectric linear array, an F/0.86 germanium lens, and an 18F4550 pic microcontroller for A/D conversion and communication. The classifier used for object recognition was trained using data collected in petting zoos and tested using data collected at the US-Mexico border in Arizona.

In this work, we propose a novel technique for face recognition with +/-90 degrees pose variations in image sequences using a cellular simultaneous recurrent network (CSRN). We formulate the recognition problem with such large-pose variations as an implicit temporal prediction task for CSRN. We exploit a face extraction algorithm based on the scale-space method and facial structural knowledge as a preprocessing step. Further, to reduce computational cost, we obtain eigenfaces for a set of image sequences for each person and use these reduced pattern vectors as the input to CSRN. CSRN learns how to associate each face class/person in the training phase. A modified distance metric between successive frames of test and training output pattern vectors indicate either a match or mismatch between the two corresponding face classes. We extensively evaluate our CSRN-based face recognition technique using the publicly available VidTIMIT Audio-Video face dataset. Our simulation shows that for this dataset with large-scale pose variations, we can obtain an overall 77% face recognition rate.

The very bright electron beam required for an x-ray free-electron laser (FEL), such as the linac coherent light source (LCLS), is susceptible to a microbunching instability in the magnetic bunch compressors, prior to the FEL undulator. The uncorrelated electron energy spread in the LCLS can be increased by an order of magnitude to provide strong Landau damping against the instability without degrading the FEL performance. To this end, a ``laser-heater'' system has been installed in the LCLS injector, which modulates the energy of a 135-MeV electron bunch with an IR-laser beam in a short undulator, enclosed within a four-dipole chicane. In this paper, we report detailed measurements of laser-heater-induced energy spread, including the unexpected self-heating phenomenon when the laser energy is very low. We discuss the suppression of the microbunching instability with the laser heater and its impact on the x-ray FEL performance. We also present the analysis of these experimental results and develop a three-dimensional longitudinal space charge model to explain the self-heating effect.

Using a novel, phase-stabilized RF-over-fiber scheme, we transmit 3GHz over 300m with 27fs RMS error in 250kHz bandwidth over 12 hours, and phase lock a laser to enable ultrafast pump-probe experiments.

Corrosion processes are often complex. Mechanisms, even in simple systems, are not always well understood. Corrosion and corrosion-assisted fracture processes in metal components are usually influenced by localized variations associated with the corrosive environments and/or the microstructures of the metallic components in contact with them. Variations in temperature, pressure, velocity, electrolyte concentrations, and stress (loading), as well as the microstructural variables of grain size, grain morphology, inclusions, second phases, dislocation densities, and others can affect corrosion and fracture mechanisms (and their extent) significantly. In this article, the influences of welding on corrosion and corrosion-related phenomena are discussed. It is shown that the application of heat and/or pressure during welding causes microstructural variations across weld zones and heat-affected zones. These variations, in turn, influence the thermodynamics and kinetics of specific corrosion processes leading to accelerated corrosion and/or fracture of the weldment. Light and electron metallographic techniques, along with accelerated electrochemical test methods, were used to measure and monitor the progression of corrosion and fracture damage as influenced by the supporting weld microstructures. The illustrations used were taken from a variety of field and laboratory corrosion studies. The observed corrosion and/or fracture-related damage reported are discussed an explained in terms of fundamental corrosion theory.

The SLAC National Accelerator Laboratory (SLAC), in collaboration with Argonne National Laboratory (ANL), Lawrence Livermore National Laboratory (LLNL), and the University of California at Los Angeles (UCLA), is constructing a Free-Electron Laser (FEL) research facility. The FEL has already met its performance goals in the wavelength range 1.5 nm - 0.15 nm. This facility, the Linac Coherent Light Source (LCLS), utilizes the SLAC 2-Mile Linear Accelerator (linac) and will produce sub-picosecond pulses of short wavelength X-rays with very high peak brightness and almost complete transverse coherence. The final one-third of the SLAC linac is used as the source of electrons for the LCLS. The high energy electrons are transported across the SLAC Research Yard, into a tunnel which houses a long undulator. In passing through the undulator, the electrons are bunched by the force of their own synchrotron radiation and produce an intense, monochromatic, spatially coherent beam of X-rays. By varying the electron energy, the FEL X-ray wavelength is tunable from 1.5 nm to 0.15 nm. The LCLS includes two experimental halls as well as X-ray optics and infrastructure necessary to create a facility that can be developed for research in a variety of disciplines such as atomic physics, materials science, plasma physics and biosciences. This Conceptual Design Report, the authors believe, confirms the feasibility of designing and constructing an X-ray instrument in order to exploit the unique scientific capability of LCLS by creating extreme conditions and study the behavior of plasma under those controlled conditions. This instrument will address the Office of Science, Fusion Energy Sciences, mission objective related to study of Plasma and Warm Dense Matter as described in the report titled LCLS, the First Experiments, prepared by the LCLS Scientific Advisory Committee (SAC) in September 2000. The technical objective of the LCLS Matter in Extreme Conditions (MEC) Instrument project is to design, build, and install at the LCLS an X-ray instrument that will complement the initial instrument suite included in the LCLS construction and the LUSI Major Item of Equipment (MIE) Instruments. As the science programs advance and new technological challenges appear, instrumentation must be developed and ready to conquer these new opportunities. The MEC concept has been developed in close consultation with the scientific community through a series of workshops team meetings and focused reviews. In particular, the MEC instrument has been identified as meeting one of the most urgent needs of the scientific community based on the advice of the LCLS Scientific Advisory Committee (SAC) in response to an open call for letters of intent (LOI) from the breadth of the scientific community. The primary purpose of the MEC instrument is to create High Energy Density (HED) matter and measure its physical properties. There are three primary elements of the MEC instrument: (A) Optical laser drivers that will create HED states by irradiation in several ways and provide diagnostics capability; (B) The LCLS x-ray free electron laser, which will provide the unique capability to create, probe and selectively pump HED states; and, (C) A suite of diagnostic devices required to observe the evolution of the HED state. These elements when combined in the MEC instrument meet the 'Mission Need' as defined in CD-0. For the purposes of the description we separate the types of experiments to be performed into three categories: (1) High pressure: Here we are interested in the generation of high pressure using the optical lasers to irradiate a surface that ablates and drives a pressure wave into a sample, similar to a piston. The pressures that can be reached exceed 1 Mbar and the properties of interest are for example, the reflectivity, conductivity, opacity as well as the changes driven by the pressure wave on, e.g., condensed matter structure. These phenomena will be studied by means of diffraction measurements, measurements of the pressure wave characteristics, in situ probing by x-ray scattering of various types all time resolved. The necessary diagnostics are discussed.

We demonstrate continuous tuning of the cubic and quartic phases of the pulse stretcher in a chirped-pulse amplification laser system. We obtain near-bandwidth-limited recompression of 100-fs pulses by minimizing the total phase through fourth order.

In this work, we propose a novel method for face recognition with large pose variations in image sequences using a Cellular Simultaneous Recurrent Network (CSRN).The pose problem is still a daunting challenge in face recognition. If the image sequences are obtained from different viewpoints in a surveillance type of application, the face recognition rate drops significantly. We formulate the recognition problem for face image sequences with large pose variation as an implicit temporal prediction task for CSRN. Further, to reduce the computational cost, we obtain eigenfaces for a set of image sequences for each person and use these reduced pattern vectors as the input to the CSRN. The CSRN is trained by this pattern vector, and each CSRN learns how to associate each face class/person in the training phase. When a new face is encountered, the corresponding image sequence is projected to each eigenface space to obtain the test pattern vectors. The Euclidian distances between successive frames of test and output pattern vectors indicate either a match or mismatch between the two corresponding face classes. We extensively evaluate our CSRN-based face recognition technique with 5 persons using publicly available VidTIMIT Audio-Video face dataset [1].In order to verify the performance of the CSRN, we also implement an Elman neural network for comparison. Our simulation shows that for this VidTIMIT Audio-Video face dataset with large pose variation, we can obtain an overall 65% (for rank 1) or 75% (for rank 2) face recognition accuracy better than the 55%(rank 1) recognition accuracy of Elman neural network.

The Linac Coherent Light Source (LCLS) is an x-ray free-electron laser project presently in a commissioning phase at the SLAC National Accelerator Laboratory. We report here on very low-emittance measurements made at low bunch charge, and a few femtosecond bunch length produced by the LCLS bunch compressors. Start-to-end simulations associated with these beam parameters show the possibilities of generating hundreds of GW at 1.5 A x-ray wavelength and nearly a single longitudinally coherent spike at 1.5 nm with 2-fs duration.

The LCLS at the SLAC National Accelerator Laboratory will be the world’s first source of an intense hard x-ray laser beam, generating x-rays with wavelengths of 1nm and pulse durations less than 100fs. The ultrafast x-ray pulses will be used in pump-probe experiments to take stop-motion pictures of atoms and molecules in motion, with pulses powerful enough to take diffraction images of single molecules, enabling scientists to elucidate fundamental processes of chemistry and biology. Ultrafast conventional lasers will be used as the pump. In 2009, LCLS will deliver beam to the Atomic Molecular and Optical (AMO) Experiment, located in one of 3 x-ray Hutches in the Near Experimental Hall (NEH). The NEH includes a centralized Laser Hall, containing up to three Class 4 laser systems, three x-ray Hutches for experiments and vacuum transport tubes for delivering laser beams to the Hutches. The main components of the NEH laser systems are a Ti:sapphire oscillator, a regen amplifier, green pump lasers for the oscillator and regen, a pulse compressor and a harmonics conversion unit. Laser safety considerations and controls for the ultrafast laser beams, multiple laser controlled areas, and user facility issues are discussed.The LCLS at the SLAC National Accelerator Laboratory will be the world’s first source of an intense hard x-ray laser beam, generating x-rays with wavelengths of 1nm and pulse durations less than 100fs. The ultrafast x-ray pulses will be used in pump-probe experiments to take stop-motion pictures of atoms and molecules in motion, with pulses powerful enough to take diffraction images of single molecules, enabling scientists to elucidate fundamental processes of chemistry and biology. Ultrafast conventional lasers will be used as the pump. In 2009, LCLS will deliver beam to the Atomic Molecular and Optical (AMO) Experiment, located in one of 3 x-ray Hutches in the Near Experimental Hall (NEH). The NEH includes a centralized Laser Hall, containing up to three Class 4 laser systems, three x-ray Hutches for experiments and vacuum transport tubes for delivering laser beams to the Hutches. The main components of the NEH laser systems are a Ti:sapphire oscillator, a regen amplifier, green pump lasers for the osci...

The pyloric network of decapod crustaceans has been intensively studied electrophysiologically in the infraorders Astacidea, Brachyura, and Palinura. The morphology of some or all pyloric neurons has been well described in Astacidea and Brachyura, but less so in Palinura. Given the large evolutionary distance between these three groups, and the large amount of electrophysiology that has been performed in palinuroid species, it is important to fill this gap. We describe here the gross morphology of all six pyloric neuron types in a palinuroid, P. interruptus. All pyloric neurons had complicated, extended dendritic trees that filled the majority of the neuropil, with most small diameter processes present in a shell near the surface of the ganglion. Certain neuron types showed modest preferences for somata location in the ganglion, but these differences were too weak to use as identifying characteristics. Quantitative measurements of secondary branch number, maximum branch order, total process length, and neuron somata diameter were also, in general, insufficient to distinguish among the neurons, although AB and LP neuron somata diameters differed from those of the other types. One neuron type (VD) had a distinctive neurite branching pattern consisting of a small initial branch followed shortly by a bifurcation of the main neurite. The processes arising from these two branches occupied largely non-overlapping neuropil. Electrophysiological recordings showed that each major branch had its own spike initiation zone and that, although the zones fired correlated spikes, they generated spikes independently. VD neurons in the other infraorders have similar morphologies, suggesting that having two arbors is important for the function of this neuron. These data are similar to those previously obtained in Brachyura and Astacidea. It thus appears that, despite their long evolutionary separation, neuron morphology in these three infraorders has not greatly diverged.

The Linac Coherent Light Source is a SASE x-ray free-electron laser (FEL) project presently under construction at SLAC [J. Arthur et al., SLAC-R-593, 2002.]. The injector section, from drive laser and rf photocathode gun through first bunch compressor chicane, was installed in the fall of 2006. The initial system commissioning with an electron beam was completed in August of 2007, with the goal of a 1.2-micron emittance in a 1-nC bunch demonstrated. The second phase of commissioning, including second bunch compressor and full linac, is planned for 2008, with FEL commissioning in 2009. We report experimental results and experience gained in the first phase of commissioning, including the photocathode drive laser, rf gun, photocathode, S-band and X-band rf systems, first bunch compressor, and the various beam diagnostics.

This issue of theJournal of Synchrotron Radiationis a special issue on X-ray free-electron lasers. Here, a brief introduction to these special issue papers is given.