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Polatuzumab vedotin, an antibody-drug conjugate containing monomethyl auristatin E, was associated with an incidence of grade ≥2 peripheral neuropathy (PN) of 55-72% in patients with indolent non-Hodgkin lymphoma in a phase II study, when dosed 1.8-2.4 mg/kg every 3 weeks until progression or for a maximum of 17 cycles. To quantify the correlation of conjugate exposure and treatment duration with PN risk, a time-to-event model was developed using data from phase I and II studies. The model suggested that PN risk increased with conjugate exposure and treatment cycles, and a trend for increased risk with body weight and albumin concentration. When capping the treatment duration to six to eight cycles, the risk ratio of a dose of 2.4 mg/kg vs. 1.8 mg/kg was ≥1.29; the predicted incidence of grade ≥2 PN at 1.8-2.4 mg/kg dose levels was 17.8-37.2%, which is comparable with other antimicrotubule agents for lymphoma treatment.

Electro-optic (EO) techniques are increasingly used for longitudinal bunch profile measurements. A bunch profile monitor, based on electro-optic spectral decoding (EOSD), has been developed and demonstrated on the CALIFES beam line at CERN. The EO response is analysed using a frequency domain description, and two methods for extraction of absolute Coulomb field strengths from the electron bunch are demonstrated. Measurements at field strengths up to 1.3 MV/m agree with the expectation based on independent charge measurements.

The dearth of success stories around extension projects implemented across South Africa (and Sub-Saharan Africa), even after substantial investment and effort, begs the question: more extension, less adoption, why? What is the role of extension in contributing to rural upliftment, the development of successful farmers, supporting stable protected natural environments and facilitating sustainable economic returns from agriculture? This paper examines the before and after effects of coordinated extension with clear targets, activities and skills development that is aimed at achieving significant rural development for a KwaZulu-Natal community. The purpose is to compare a period of 10 years of uncoordinated extension services with the following 10 years using a targeted structured extension methodology with set measurable outputs, implemented in the same community. Ten years of data in a community which received uncoordinated extension with little support from outside organisations were compared to the results of the following ten years after the implementation of a new, structured extension approach. Extension officers were upskilled, monitored and evaluated on their impact on the development of agriculture and the improvement of livelihoods in the community. There were 224 growers delivering 16 456 tons of sugarcane in 2004. The growth in the agricultural sector over the past decade was compared to the previous ten years and comparisons made for a number of variables which were indicative of the success of the project in terms of adoption, increased agricultural participation and improved production systems. In 2018, there were 704 growers delivering 50 300 tons of sugarcane. The rate and scale of adoption, and increased community confidence in agriculture as a livelihood, is clearly evident in the increased number ofgrowers from 419 in 2013 to 704 in 2018. An extension impact monitoring system and annual work plan was also developed to assist extension officers and their managers to have a clear understanding of roles and responsibilities, as well as being utilised to measure the impact of the extension officers in the area. The agricultural system has become a self-perpetuating one that demonstrates the enormous social, developmental and economic benefits of a sustainable agricultural community.

Polatuzumab vedotin, an antibody‐drug conjugate containing monomethyl auristatin E, was associated with an incidence of grade ≥2 peripheral neuropathy (PN) of 55–72% in patients with indolent non‐Hodgkin lymphoma in a phase II study, when dosed 1.8–2.4 mg/kg every 3 weeks until progression or for a maximum of 17 cycles. To quantify the correlation of conjugate exposure and treatment duration with PN risk, a time‐to‐event model was developed using data from phase I and II studies. The model suggested that PN risk increased with conjugate exposure and treatment cycles, and a trend for increased risk with body weight and albumin concentration. When capping the treatment duration to six to eight cycles, the risk ratio of a dose of 2.4 mg/kg vs. 1.8 mg/kg was ≥1.29; the predicted incidence of grade ≥2 PN at 1.8–2.4 mg/kg dose levels was 17.8–37.2%, which is comparable with other antimicrotubule agents for lymphoma treatment.

It is proposed to use the Oxford 10 MV Van de Graaff accelerator as an electron beam source for a free electron laser (FEL) operating in the far infra red (FIR). The configuration and layout of the Van de Graaff make it very suitable for conversion, with a potentially high efficiency for electron beam recovery. Using a 2 m long wiggler of 34 mm period, the FEL would operate in the 60-300 /spl mu/m wavelength band, with extension down to 30 /spl mu/m on the 3rd harmonic. When constructed, the FEL will support a programme of FEL research and development, concentrating at first on investigations of behaviour in the moderately high-gain regime (/spl equiv/ 100% per pass) and mechanisms for lasing on higher harmonics. It will also be the basis for a national UK user facility in the FIR.

Radially and azimuthally polarized picosecond (~10 ps) pulsed laser irradiation at 532 nm wavelength led to the permanent reshaping of spherical silver nanoparticles (~30 - 40 nm in diameter) embedded in a thin layer of soda-lime glass. The observed peculiar shape modifications consist of a number of different orientations of nano-ellipsoids in the cross-section of each written line by laser. A Second Harmonic Generation cross-sectional scan method from silver nanoparticles in transmission geometry was adopted for characterization of the samples after laser modification. The presented approach may lead to sophisticated marking of information in metal-glass nanocomposites.

The structure of mechanically instrumented intraradicular dentin after irrigation with NaOCl as the initial rinse and BioPure MTAD as the final rinse were examined from the coronal, middle, and apical parts of root canal walls using transmission electron microscopy. Sterile distilled water and EDTA as final rinses were employed as the respective positive and negative controls under the same experimental conditions. There were 2 to 5 mum thick smear layers produced on mechanically instrumented root canal walls that were completely removed by EDTA and BioPure MTAD under agitation. Both irrigants created a zone of demineralized collagen matrices in eroded dentin and around the dentinal tubules, with the mildly acidic BioPure MTAD being more aggressive than EDTA. These demineralized dentin zones create the opportunity for dentin hybridization by infiltration of hydrophilic adhesives/sealers. However, the potential consequences of compaction of hydrophobic sealers against air-dried, collapsed collagen matrices, and hydrolytic degradation of incompletely infiltrated matrices remain unresolved.

Electro-optic (EO) detection of relativistic Coulomb fields offers a method for non-destructive longitudinal profile measurements of ultrashort bunches. Techniques for single-shot EO characterisation of Coulomb fields which have been developed or demonstrated at the FELIX free electron laser (FEL) facility are discussed. In addition, recent FELIX experiments have used single-shot electro-optic detection to measure the temporal profile of the far-infrared electric field pulse of coherent synchrotron radiation (CSR), initial results of which are reported here. Such time-resolved CSR measurements have the potential for a completely non-invasive bunch longitudinal profile determination, without the ambiguity in profile that is present in CSR spectral measurements.

Summary The design of a head-mounted display with a field of view of 40 degrees and suitable for use with a micro display of 17.5 mm diagonal is presented. It is a combination of a diffractive-refractive eyepiece with an appropriate reflective relay system. The eyepiece design is based on a Kellner eyepiece. By replacing the cemented-doublet of the traditional eyepiece with a diffractive-refractive element (a plano-convex lens with the plane surface as the diffractive surface) an improved eyepiece is obtained. The proposed eyepiece shows a considerable reduction in physical size (which is particularly important for binocular systems) and weight, and exhibits superior performance compared to the traditional refractive type. It is emphasized that the proposed design has a performance that is well matched to a micro display with SXGA resolution.

Linear accelerators employed as drivers for X-ray free electron lasers (FELs) require relativistic electron bunch with sub-picosecond bunch length. Precise bunch length measurements are important for the tuning and operation of the FELs. Previously, we have demonstrated that electro-optic detection is a powerful technique for sub-picosecond electron bunch length measurements. In those experiments, the measured bunch length was the average of all electron bunches within a macropulse. Here, for the first time, we present the measurement of the length of individual electron bunches using a development of our previous technique. In this experiment, the longitudinal electron bunch shape is encoded electro-optically on to the frequency spectrum of a chirped laser pulse. Subsequently, the laser pulse is dispersed by a grating and the spectrum is imaged with a CCD camera. Single bunch measurements are achieved by using a nanosecond gated camera, and synchronizing the gate with both the electron bunch and the laser pulse repetition rates. The electron bunch length is determined by measuring the laser pulse spectra with and without the presence of an electron bunch. We demonstrate that this method enables a real-time diagnostic for the bunch length of single electron bunches with a time resolution of 370 femtoseconds and a high signal-noise-ratio.

Summary Two kinds of hybrid diffractive-refractive ultra-wide-angle (70°) eyepieces are designed which are with considerably reduced apparent size and weight and with comparable or improved aberrations as compared with the conventional refractive countertype. The designing strategy including the consideration and the steps of the optimization, the most important specification of the diffractive efficiency, and the manufacture issues is presented. The structures and the performance merits of the designed systems are given in a comparison of the traditional Scidmore eyepiece. The designed eyepieces have potential applications in various kinds of modern head-mounted displays.

A general description of electro-optic detection including non-collinear phase matching and finite transverse beam profiles is presented. It is shown theoretically and experimentally that non-collinear phase matching in ZnTe (and similar materials) produces an angular chirp in the χ(2)- generated optical signal. Due to this, in non-collinear THz and probe arrangements such as single-shot THz measurements or through accidental misalignment, measurement of an undistorted THz signal is critically dependent on having sufficient angular acceptance in the optical probe path. The associated spatial walk-off can also preclude the phase retardation approximation used in THz-TDS. The rate of misalignment-induced chirping in commonly used ZnTe and GaP schemes is tabulated, allowing ready analysis of a detection system. © 2014 Optical Society of America.

A photorefractive joint transform correlator using circular harmonic filters and the wavelet transform for high discriminant and rotationally invariant pattern recognition is reported. In the experimental implementation, a photorefractive crystal, BSO, is used as the dynamic holographic medium and a bank of wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve a band-pass operation in the Fourier domain. The zero-order and second-order circular harmonic components are used in the investigation. It is shown that, with the proper dilation factors, there is a trade-off between peak correlation intensity and signal-to-noise ratio (SNR) with the wavelet transform filters. With the second-order circular harmonic, an improvement of 63% in the SNR is achieved with only a 4% loss in the peak correlation intensity.

The wavelet transform has found a lot of uses in the field of optics. We present an experimental realization of employing variant wavelet filters into the object space of a photorefractive joint transform correlator to realize image feature extraction. The Haar’s wavelet, Roberts gradient and Mexican-hat wavelet are employed in the experiment. Because of its good optical properties, the photorefractive crystal Bi12SiO20 is used as the dynamic holographic medium in the Fourier plane. Both scene and reference have been detour-phase encoded in a liquid crystal television in the input plane. Computer simulations, experimental results and analysis are presented.

Time-resolved measurements of the transverse electric field associated with relativistic electron bunches are presented. Using an ultrafast electro-optic sensor close to the electron beam, the longitudinal profile of the electric field was measured with subpicosecond time resolution and without time-reversal ambiguity. Results are shown for two cases: inside the vacuum beam line in the presence of wake fields, and in air behind a beryllium window, effectively probing the near-field transition radiation. Especially in the latter case, reconstruction of the longitudinal electron bunch shape is straightforward.

(2000). The Elderly and Prison Policy. Journal of Aging & Social Policy: Vol. 11, No. 2-3, pp. 167-175.

The detailed shape of picosecond optical pulses from a free-electron laser (FEL) oscillator has been studied for various cavity detunings. For large values of the cavity detuning the optical pulse develops an exponential leading edge, with a time constant proportional to the applied cavity detuning and the quality factor of the resonator. This behavior has been observed at two separate FELs that have completely different resonator layouts and electron beam characteristics, and using different methods of optical pulse length measurement. The optical pulses have a full width at half maximum time-bandwidth product Delta t(FWHM)Delta f(FWHM) of 0.2-0.3. The results presented here can be used to predict the optical pulse length and corresponding minimum spectral width that can be generated in a FEL pumped by short electron bunches. This is important for the design of new infrared free-electron laser user facilities, which need to make a balanced choice between short pulses for high temporal resolution and narrow bandwidth for linear and nonlinear spectroscopy.

We have investigated a real-time photorefractive joint transform correlator (JTC) with a bank of wavelet filters. In the experimental set-up, a photorefractive crystal BSO has been used as the dynamic holographic medium and a bank of discrete wavelet functions, derived from a mother Mexican-hat wavelet have been selected to achieve band-pass operations in the JTC Fourier domain. With the proper dilation factors, shaper correlation peaks, higher discrimination ability and higher noise robustness have been obtained. Experimental results and analysis are presented.

We present an experimental realization of optical correlation for real-time rotational-invariance pattern recognition by means of a photorefractive joint transform correlator. Single and multiple circular harmonic components have been used to form correlation filters. The correlator operates with a liquid crystal television as the input images and a photorefractive crystal Bi 12 SiO 20 (BSO) as the recording medium. Suitable pre-processing of the references at the object plane makes up for the lack of light transmission. The properties of circular harmonic phase-only filter and circular harmonic matched filter have been compared. Also the noise robustness of these filters has been tested by tracking an object against a non-overlapping noise background. Analysis and experimental results are presented.

Sediments were collected from Steilacoom Lake, Pierce County, in Washington State, and amended with copper sulfate (nominal concentrations of 800, 1,000, 1,500, and 2,000 mg Cu/kg dry weight) to assess copper bioavailability to Hyalella azteca, Chironomus tentans, or Ceriodaphnia dubia. H. azteca survival and C. tentans survival and growth were not significantly affected, with 10-day no observed effects concentrations (NOEC) and lowest observed effects concentrations (LOEC) of 2,010 and2,010 mg Cu/kg, respectively. C. dubia was the most sensitive organism tested with 10-day NOEC and LOECs for survival and reproduction of 906 and 1,469 mg Cu/kg, respectively. Sediment AVS concentrations were0.15 micromol/g, while simultaneously extracted metal (SEM) concentrations were/=5. 71 micromol Cu/g. Dissolved interstitial water concentrations ranged from below detection (0.010 mg/L) to 0.24 mg Cu/L, with interstitial water toxicity units as high as 3.4. Based on this study, effects to C. dubia may occur at bulk sediment concentrations906 mg Cu/kg. Further, AVS and interstitial water concentrations are not accurate predictors of copper bioavailability in Steilacoom Lake.

In impaction grafting of contained bone defects after revision joint arthroplasty the graft behaves as a friable aggregate and its resistance to complex forces depends on grading, normal load and compaction. Bone mills in current use produce a distribution of particle sizes more uniform than is desirable for maximising resistance to shear stresses. We have performed experiments in vitro using morsellised allograft bone from the femoral head which have shown that its mechanical properties improve with increasing normal load and with increasing shear strains (strain hardening). The mechanical strength also increases with increasing compaction energy, and with the addition of bioglass particles to make good the deficiency in small and very small fragments. Donor femoral heads may be milled while frozen without affecting the profile of the particle size. Osteoporotic femoral heads provide a similar grading of sizes, although fewer particles are obtained from each specimen. Our findings have implications for current practice and for the future development of materials and techniques.

Laboratory toxicity data contrasting responses of aquatic organisms to insecticides are important for focusing on sensitive species (steepest exposure-response slope) exposed to aqueous concentrations of these insecticides in field studies. These data also allow prediction of expected responses of aquatic species to a range of insecticide concentrations in situ. Aqueous 48-h toxicity tests were performed to contrast responses of Daphnia magna Straus, Hyalella azteca Saussure, Chironomus tentans Fabricius, and Pimephales promelas Rafinesque to acetylcholinesterase-inhibiting insecticides: chlorpyrifos, aldicarb, and chlordane. As expected, invertebrates tested (H. azteca, C. tentans, and D. magna) were/= 200 times more sensitive than the vertebrate P. promelas to chlorpyrifos exposures. H. azteca was approximately 3.5 times more sensitive to chlorpyrifos (453% mortality/mgr;g/L) than D. magna (128% mortality/mgr;g/L). For both aldicarb and chlordane, C. tentans was the most sensitive species tested (2.44 and 2.54% mortality/mgr;g/L, respectively). Differences in chlordane potency for test species varied only by a factor of approximately 2-3 (0.88% mortality/mgr;g/L for H. azteca to 2.54% mortality/mgr;g/L for C. tentans). Although point estimates of population responses such as LC50s, NOECs, and LOECs are of some utility for predicting effects of pesticides in aquatic systems, exposure-response slopes are also useful for extrapolation of laboratory data to diverse field situations, especially where sediment sorption may regulate insecticide exposure or bioavailability.

We studied the presence of sensory nerves by immunohistochemistry in the interface membranes of hip prostheses after aseptic loosening. Substance P (SP), neurokinin A (NKA) and calcitonin gene-related peptide (CGRP) were analysed as was protein gene product (PGP) 9.5, a general marker for nerve fibres. We identified nerve fibres in all samples but differences in their density were found. SP- and NKA-positive fibres were predominantly non-vascular, forming varicose nerve terminals. CGRP-immunoreactive nerve fibres with varicose terminals were seen mostly close to blood vessels, but also as free nerve endings. Sensory neuropeptides participate not only in nociception but also stimulate immune cells to release cytokines. The presence of sensory nerves in the interface membrane may reflect a pathophysiological response contributing to the aseptic loosening of hip prostheses.

Narrow band undulator radiation tuneable over the wavelength range of 150–260 nm has been produced by short electron bunches from a 2 mm long laser plasma wakefield accelerator based on a 20 TW femtosecond laser system. The number of photons measured is up to 9 × 106 per shot for a 100 period undulator, with a mean peak brilliance of 1 × 1018 photons/s/mrad2/mm2/0.1% bandwidth. Simulations estimate that the driving electron bunch r.m.s. duration is as short as 3 fs when the electron beam has energy of 120–130 MeV with the radiation pulse duration in the range of 50–100 fs.

We have reviewed the clinical and functional results of 21 centralizations for radial club hand in 17 patients, 21 to 31 (mean 27) years after operation. There were 13 associated pollicizations. Although the ulna was always short, no premature fusions of the distal ulnar epiphysis were found. Overall upper limb function was assessed by grip strengths and Moberg and Jebsen tests of manual dexterity and was satisfactory. This review emphasizes the important roles of centralization and pollicization in the surgical management of children with radial absence.

Picosecond (~10 ps) pulsed laser irradiation at 532 nm led to the efficient and scalable fabrication of dichroic areas in glass with spherical silver nanoparticles of ~30 – 40 nm in diameter embedded in a surface layer of thickness ~20 μm. The observed dichroism is due to the uniform and permanent shape transformation of the nanoparticles - from spherical to spheroidal shapes - throughout the irradiated areas and along the laser polarization direction, paving the way for affordable manufacture of polarization-selective diffractive optical elements. The shape modification threshold and the dichroism as a result of Surface Plasmon Resonance band separation were identified. The process was then studied as a function of the laser polarization, repetition rate and the number of pulses fired per spot.

A design study is presented for a beam injection system suitable for a free-electron laser (FEL) and other purposes, which in its normal mode is isochronous to second order in the particle co-ordinates, yet which may be progressively shifted from the isochronous condition by alteration of the strengths (and for larger deviations the locations) of some of its magnetic elements. The system uses a minimum number of magnetic components (3–4 dipoles and 2 quadrupole triplets), and can produce both positive and negative deviations from isochronism within the range ±30 ps/% momentum deviation. The major second-order chromatic and geometric aberrations are minimised by the use of sextupoles. Use of the system for electron bunch compression in an FEL is discussed.

The use of a far-infrared free-electron laser as voltage-controlled optical oscillator is reported. The optical spectrum is able to follow a set of pre-programmed waveforms applied to the electron energy. The time-resolved spectral output has been measured at several wavelengths and cavity desynchronisms. Maximum sweep rates of 1.4%/μs were measured at 20μm wavelength and total sweeps of 2.0% in wavelength have been produced.

Time-resolved electron-beam diagnostics have been developed for use with free-electron lasers (FELs) and associated electron sources, based on the techniques of secondary electron emission and optical transition radiation (OTR). The 32-channel OTR detector forms part of a high-resolution (0.18%) electron spectrometer with a time resolution of 50 ns. Variable-magnification optics allow the spectrometer to view single-macropulse spectra with widths in the range of 0.2%-7%; wider spectra are taken with several momentum settings. Design criteria for the spectrometer are presented, and experience of operating with the diagnostics over a range of FEL physics experiments is summarized. The spectrometer is used, in conjunction with optical diagnostics, in studies at FELIX of efficiency enhancement, pulse chirping, and stepped-undulator operation. (C) 1996 American Institute of Physics.

A 32 channel data acquisition system has been developed to monitor, at intervals of 50 ns, the variation in the electron energy spectrum of a free electron laser during the 10 μs duration of the electron beam pulses which repeat at a frequency of approximately 10 Hz. The data are made available to the user in a variety of ways: as graphics displays on a VDU and as an archive that allows the latest data to be accessible to users at workstations elsewhere on the laboratory network. A low-cost, simple and robust system is described that will find application in other areas where real-time, rapid, multi-channel sampling is required, and an insight is provided into the design of both hardware and software aspects of a multitasking multiprocessor system.

Spherical silver nanoparticles (NPs) of 30 nm diameter embedded in soda-lime glass were uniformly reshaped (elongated) after irradiation by a linearly polarised 250 fs pulsed laser operating within the NPs' surface plasmon resonance band. We observed second harmonic generation (SHG) and multiphoton-absorption-induced luminescence (MAIL) in the embedded laser-reshaped NPs upon picosecond (10 ps) pulsed laser excitation at 1064 nm. A complementary study of SHG and MAIL was conducted in soda-lime glass containing embedded, mechanically-reshaped silver NPs of a similar elongation ratio (aspect ratio) to the laser-reshaped NPs. This supports the notion that the observed difference in SHG and MAIL in the studied nanocomposite systems is due to the shape modification mechanism. The discrete dipole approximation method was used to assess the absorption and scattering cross-sections of the reshaped NPs with different elongation ratios.

Effects of large (LA; 400 min/wk) and moderate (MA; 200 min/wk) amounts of endurance exercise in combination with weight training (3 d/wk) were compared with the effects of no exercise (C) in 23 obese females after a 12-wk, 3360-kJ/d very-low-energy diet (VLED). The LA group lost 6.5 kg more weight, mainly as fat (6.4 kg), than the C group (P < 0.05). No measurable differences were found among groups for decreases in resting metabolic rate (-729 to -1233 kJ/d; NS) or fat-free mass (-2.9 to -3.9 kg; NS). No improvements in aerobic capacity were achieved with the addition of exercise to a VLED (-0.079 to -0.037 L/min; NS). Strength indexes were improved (+16 to +5 kg; P < 0.05) or maintained with exercise (-3 kg; NS) whereas a loss (-9.3 kg; P < 0.05) or maintenance (+4.5 kg; NS) was found for VLED alone. Large amounts of endurance exercise in combination with weight training added to a VLED appear to improve weight and fat loss compared with a VLED alone.

Measurements of the FELIX electron energy spectrum using multichannel secondary emission monitors are described. The detectors have a time resolution of 50 ns and span typically 4% in electron energy over 32 channels. Aspects of the design of the OTR detector and energy spectrometer for FELIX are presented, along with data recently acquired with the time-resolved system.

We demonstrate the spectral upconversion of a unipolar subpicosecond terahertz (THz) pulse, where the THz pulse is the Coulomb field of a single relativistic electron bunch. The upconversion to the optical allows remotely located detection of long wavelength and nonpropagating components of the THz spectrum, as required for ultrafast electron bunch diagnostics. The upconversion of quasimonochromatic THz radiation has also been demonstrated, allowing the observation of distinct sum- and difference-frequency mixing components in the spectrum. Polarization dependence of first and second order sidebands at omega(opt) +/- omega(THz), and omega(opt) +/- 2 omega(THz), respectively, confirms the chi((2)) frequency mixing mechanism. (C) 2010 American Institute of Physics. [doi: 10.1063/1.3449132]

The effects of binarization of the input and the reference data in a correlator with the amplitude-compensated matched filter have been investigated. Computer simulations show that with binarization the noise tolerance of the correlator shows a significant improvement without compromising the other performance merits of the spatial filter. This is critical in the application of the amplitude-compensated matched filter, since the energy absorption of this type of filter severely reduces the input noise tolerance.

We present experimental results describing the influence of optical bias on the transient characteristics of gratings formed in photorefractive BSO. A transient peak is evident, and the properties of this peak can be controlled by suitable adjustment of the relative intensities of the optical beams involved.

The Advanced Laser-Plasma High-Energy Accelerators towards X-rays (ALPHA-X) programme is developing laserplasma accelerators for the production of ultra-short electron bunches with subsequent generation of incoherent radiation pulses from plasma and coherent short-wavelength radiation pulses from a free-electron laser (FEL). The first quantitative measurements of the electron energy spectra have been made on the University of Strathclyde ALPHA-X wakefield acceleration beam line. A high peak power laser pulse (energy 900 mJ, duration 35 fs) is focused into a gas jet (nozzle length 2 mm) using an F/16 spherical mirror. Electrons from the laser-induced plasma are self-injected into the accelerating potential of the plasma density wake behind the laser pulse. Electron beams emitted from the plasma have been imaged downstream using a series of Lanex screens positioned along the beam line axis and the divergence of the electron beam has been measured to be typically in the range 1-3 mrad. Measurements of the electron energy spectrum, obtained using the ALPHA-X high resolution magnetic dipole spectrometer, are presented. The maximum central energy of the monoenergetic beam is 90 MeV and r.m.s. relative energy spreads as low as 0.8% are measured. The mean central energy is 82 MeV and mean relative energy spread is 1.1%. A theoretical analysis of this unexpectedly high electron beam quality is presented and the potential impact on the viability of FELs driven by electron beams from laser wakefield accelerators is examined.

Precise measurements of the temporal profile of ultrashort electron bunches are of high interest for the optimization and operation of ultraviolet and x-ray free-electron lasers. The electro-optic (EO) technique has been applied for a single-shot direct visualization of the time profile of individual electron bunches at FLASH. This paper presents a thorough description of the experimental setup and the results. An absolute calibration of the EO technique has been performed utilizing simultaneous measurements with a transverse-deflecting radio-frequency structure that transforms the longitudinal bunch charge distribution into a transverse streak. EO signals as short as 60 fs (rms) have been observed using a gallium-phosphide (GaP) crystal, which is a new record in the EO detection of single electron bunches and close to the physical limit imposed by the EO material properties. The data are in quantitative agreement with a numerical simulation of the EO detection process.

BACKGROUND: Vitamin D and related compounds have been used to prevent osteoporotic fractures in older people. OBJECTIVES: To determine the effects of vitamin D or related compounds, with or without calcium, for preventing fractures in older people. SEARCH STRATEGY: We searched the Cochrane Bone, Joint and Muscle Trauma Group Specialised Register, the Cochrane Central Register of Controlled Trials (The Cochrane Library 2007, Issue 3), MEDLINE, EMBASE, CINAHL, and reference lists of articles. Most recent search: October 2007. SELECTION CRITERIA: Randomised or quasi-randomised trials comparing vitamin D or related compounds, alone or with calcium, against placebo, no intervention, or calcium alone, reporting fracture outcomes in older people. DATA COLLECTION AND ANALYSIS: Two authors independently assessed trial quality, and extracted data. Data were pooled, where admissible, using the fixed-effect model, or random-effects model if heterogeneity between studies appeared high. MAIN RESULTS: Forty-five trials were included. Vitamin D alone appears unlikely to be effective in preventing hip fracture (nine trials, 24,749 participants, RR 1.15, 95% CI 0.99 to 1.33), vertebral fracture (five trials, 9138 participants, RR 0.90, 95% CI 0.42 to 1.92) or any new fracture (10 trials, 25,016 participants, RR 1.01, 95% CI 0.93 to 1.09).Vitamin D with calcium reduces hip fractures (eight trials, 46,658 participants, RR 0.84, 95% CI 0.73 to 0.96). Although subgroup analysis by residential status showed a significant reduction in hip fractures in people in institutional care, the difference between this and the community-dwelling subgroup was not significant (P = 0.15).Overall hypercalcaemia is significantly more common in people receiving vitamin D or an analogue, with or without calcium (18 trials, 11,346 participants, RR 2.35, 95% CI 1.59 to 3.47); this is especially true of calcitriol (four trials, 988 participants, RR 4.41, 95% CI 2.14 to 9.09). There is a modest increase in gastrointestinal symptoms (11 trials, 47,042 participants, RR 1.04, 95% CI 1.00 to 1.08, P = 0.04) and a small but significant increase in renal disease (11 trials, 46,537 participants, RR 1.16, 95% CI 1.02 to 1.33). AUTHORS' CONCLUSIONS: Frail older people confined to institutions may sustain fewer hip fractures if given vitamin D with calcium. Vitamin D alone is unlikely to prevent fracture. Overall there is a small but significant increase in gastrointestinal symptoms and renal disease associated with vitamin D or its analogues. Calcitriol is associated with an increased incidence of hypercalcaemia

Holographic recording with orthogonally polarized beams in a cesium-doped KNSBN [(K0.5Na0.5)0.2(Sr0.75Ba0.25)0.9Nb2O6] crystal has been studied. It was found that this kind of photorefractive crystal possesses high linear dichroism, which makes it suitable for use in polarization holography. The diffraction efficiency as a function of the polarization orientation of the reference beam and as a function of the fringe modulation at the optimum polarization orientation of the reference beam is experimentally investigated. Theoretical fitting based on Kahmann models was performed and agrees well with the experimental data. In the experiments, both polarization holography and conventional holography are used to record a binary object. The reconstruction shows that polarization holography with Ce:KNSBN is highly effective, exhibiting high diffraction efficiency and reduced fanning noise.