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Proton beams driven by chirped pulse amplified lasers have multi-picosecond duration and can isochorically and volumetrically heat material samples, potentially providing an approach for creating samples of warm dense matter with conditions not present on Earth. Envisioned on a larger scale, they could heat fusion fuel to achieve ignition. We have shown in an experiment that a kilojoule-class, multi-picosecond short pulse laser is particularly effective for heating materials. The proton beam can be focussed via target design to achieve exceptionally high flux, important for the applications mentioned. The laser irradiated spherically curved diamond-like-carbon targets with intensity 4 × 1018 W/cm2, producing proton beams with 3 MeV slope temperature. A Cu witness foil was positioned behind the curved target, and the gap between was either empty or spanned with a structure. With a structured target, the total emission of Cu Kα fluorescence was increased 18 fold and the emission profile was consistent with a tightly focussed beam. Transverse proton radiography probed the target with ps order temporal and 10 μm spatial resolution, revealing the fast-acting focussing electric field. Complementary particle-in-cell simulations show how the structures funnel protons to the tight focus. The beam of protons and neutralizing electrons induce the bright Kα emission observed and heat the Cu to 100 eV.

Intense lasers can accelerate protons in sufficient numbers and energy that the resulting beam can heat materials to exotic warm (10 s of eV temperature) states. Here we show with experimental data that a laser-driven proton beam focused onto a target heated it in a localized spot with size strongly dependent upon material and as small as 35 μm radius. Simulations indicate that cold stopping power values cannot model the intense proton beam transport in solid targets well enough to match the large differences observed. In the experiment a 74 J, 670 fs laser drove a focusing proton beam that transported through different thicknesses of solid Mylar, Al, Cu or Au, eventually heating a rear, thin, Au witness layer. The XUV emission seen from the rear of the Au indicated a clear dependence of proton beam transport upon atomic number, Z, of the transport layer: a larger and brighter emission spot was measured after proton transport through the lower Z foils even with equal mass density for supposed equivalent proton stopping range. Beam transport dynamics pertaining to the observed heated spot were investigated numerically with a particle-in-cell (PIC) code. In simulations protons moving through an Al transport layer result in higher Au temperature responsible for higher Au radiant emittance compared to a Cu transport case. The inferred finding that proton stopping varies with temperature in different materials, considerably changing the beam heating profile, can guide applications seeking to controllably heat targets with intense proton beams.

Roots contribute a large fraction of CO 2 efflux from soils, yet the extent to which global change factors affect root-derived fluxes is poorly understood. We investigated how red maple (Acer rubrum) and red oak (Quercus rubra) root biomass and respiration respond to long-term (15 years) soil warming, nitrogen addition, or their combination in a temperate forest. We found that ecosystem root respiration was decreased by 40% under both single-factor treatments (nitrogen addition or warming) but not under their combination (heated × nitrogen). This response was driven by the reduction of mass-specific root respiration under warming and a reduction in maple root biomass in both single-factor treatments. Mass-specific root respiration rates for both species acclimated to soil warming, resulting in a 43% reduction, but were not affected by N addition or the combined heated × N treatment. Notably, the addition of nitrogen to warmed soils alleviated thermal acclimation and returned mass-specific respiration rates to control levels. Oak roots contributed disproportionately to ecosystem root respiration despite the decrease in respiration rates as their biomass was maintained or enhanced under warming and nitrogen addition. In contrast, maple root respiration rates were consistently higher than oak, and this difference became critical in the heated × nitrogen treatment, where maple root biomass increased, contributing significantly more CO 2 relative to single-factor treatments. Our findings highlight the importance of accounting for the root component of respiration when assessing soil carbon loss in response to global change and demonstrate that combining warming and N addition produces effects that cannot be predicted by studying these factors in isolation., (© 2024 John Wiley & Sons Ltd.)

Following a resource pulse, animals may finance reproduction by consuming concurrently available resources (income breeding) or by storing resources for future reproduction (capital breeding). Understanding how these reproductive strategies are used is important for determining the ecological mechanisms that structure timing of reproduction and that drive interannual population fluctuations in animals. We gathered a reproductive dataset for five small mammal species over a 12-year period in Northeastern USA during which six masting events of American beech (Fagus grandifolia) and eastern hemlock (Tsuga canadensis) occurred. Masting created alternate years where seeds were either available late (masting year) or early (cached from the previous year) in the breeding season. The small mammal species differed in reliance on seeds and overwintering strategies. We quantified the diet using stable isotopes and recorded reproduction timing, proportion breeding and litter size in females and testes size in males. Timing of seed availability minimally affected litter size but strongly affected proportion breeding and timing of reproduction. During masting years (late seed availability), a higher proportion of females reproduced, with breeding taking place later in the season (lactation timed with peak seed availability), although the delay was restricted in Napaeozapus insignis, an obligate hibernator. After a fall mast, cached seeds were used as capital in the following spring (early seed availability) to support a litter that, depending on the species, occurred 24-79 days sooner than a mast year. No late-season reproduction occurred in years with early seed availability except for Myodes gapperi which produced a second litter, likely financed by fungal consumption. Males also showed strong responses to seed availability, mirroring female reproduction with testes size staying constant in years with late seed availability and sharply decreasing over the breeding season in years with early seed availability. Our results highlight that although photoperiod and temperature broadly set bounds of the breeding season in temperate environments, resource availability influences the reproductive strategies that species use, which in turn alters reproductive timing and can drive large inter-annual population fluctuations. Differences in overwintering strategies and diet may further modulate reproductive timing and output relative to resource pulses., (© 2024 The Author(s). Journal of Animal Ecology © 2024 British Ecological Society.)

Enabled by surface-mediated equilibration, physical vapour deposition can create high-density stable glasses comparable with liquid-quenched glasses aged for millions of years. Deposition is often performed at various rates and temperatures on rigid substrates to control the glass properties. Here we demonstrate that on soft, rubbery substrates, surface-mediated equilibration is enhanced up to 170 nm away from the interface, forming stable glasses with densities up to 2.5% higher than liquid-quenched glasses within 2.5 h of deposition. Gaining similar properties on rigid substrates would require 10 million times slower deposition, taking ~3,000 years. Controlling the modulus of the rubbery substrate provides control over the glass structure and density at constant deposition conditions. These results underscore the significance of substrate elasticity in manipulating the properties of the mobile surface layer and thus the glass structure and properties, allowing access to deeper states of the energy landscape without prohibitively slow deposition rates., (© 2024. The Author(s), under exclusive licence to Springer Nature Limited.)

Here we present the results of taxonomic and systematic study of the rare truffle-forming genera Destuntzia and Kjeldsenia . Truffle-forming fungi are difficult to study due to their reduced morphological features and their cryptic, hypogeous fruiting habits. The rare occurrence of Destuntzia and Kjeldsenia further compounds these difficulties due to the lack of adequate material for study. Recent forays in North Carolina and Tennessee recovered new specimens of another rarely collected fungus, Octaviania purpurea . Morphological and phylogenetic analysis revealed that Octaviania purpurea is a member of the genus Destuntzia , and this led us to reevaluate the taxonomic status and systematic relationships of other Destuntzia species. We performed a multilocus phylogenetic analysis of Destuntzia specimens deposited in public fungaria, including all available type material, and environmental sequences from animal scat and soil. Our analyses indicate that Destuntzia is a member of the family Claustulaceae within the order Phallales and is a close relative of Kjeldsenia . Results of our phylogenetic analysis infer that three species originally described in the genus Destuntzia are members of the genus Kjeldsenia . We propose three new combinations in Kjeldsenia to accommodate these species as well as a new combination in Destuntzia to accommodate Octaviania purpurea . We also describe a new genus in Claustulaceae, Hosakaea , to accommodate a closely affiliated species, Octaviania violascens . Finally, we transfer the genus Destunzia into the family Claustulaceae and emend the description of the family. The newly proposed combinations in Destuntzia and Kjeldsenia significantly expand the known geographic ranges of both genera. The data from metabarcode analysis of scat and soil also reveal several additional undescribed species that expand these ranges well beyond those suggested by basidiomata collections. Systematic placement of Destuntzia in the saprotrophic order Phallales suggests that this genus is not ectomycorrhizal, and the ecological implications of this systematic revision are discussed.

Objectives: This study aimed to evaluate the feasibility and effectiveness of providing bedside family planning services to women with chronic medical conditions in the inpatient setting., Study Design: We initiated a parallel randomized controlled trial of patients listed as female aged 18 to 44 years who were admitted to the hospital from February 2018 to May 2021 with at least one chronic medical condition associated with lower rates of contraception usage and no documentation of contraception. Patients who confirmed they were not using contraception were enrolled and randomized to one of the three arms. They received bedside family planning counseling and an offer of contraception prior to discharge (oral contraceptive pills, etonogestrel implant, or medroxyprogesterone injection), received a flyer recommending they talk with their outpatient physician about contraception, or received standard care. The primary outcomes were contraception use at 3 months and 12 months after discharge., Results: Altogether 76 subjects were enrolled and randomized with 22 in the counseling arm and 27 each in the other arms. In the counseling arm, five (23%; 95% CI: 8.0%-45%) elected to receive contraception prior to discharge. Inferential statistics at follow-up were not able to be calculated due to high attrition., Conclusions: Providing counseling and offering immediate contraception initiation in the inpatient setting may be a feasible approach to improving contraception access for this population. Additional investigation into the acceptability, efficacy, and generalizability of this approach is warranted., Implications: Utilizing the inpatient setting may be a feasible approach for delivering contraception counseling to women with chronic medical conditions. This approach merits further study for effectiveness and acceptability. This study highlights the need for contraceptive counseling and initiation to become a standard part of hospital care for pregnancy-capable individuals., (Copyright © 2023 The Authors. Published by Elsevier Inc. All rights reserved.)

Following a disturbance, dispersal shapes community composition as well as ecosystem structure and function. For fungi, dispersal is often wind or mammal facilitated, but it is unclear whether these pathways are complementary or redundant in the taxa they disperse and the ecosystem functions they provide. Here, we compare the diversity and morphology of fungi dispersed by wind and three rodent species in recently harvested forests using a combination of microscopy and Illumina sequencing. We demonstrate that fungal communities dispersed by wind and small mammals differ in richness and composition. Most wind-dispersed fungi are wood saprotrophs, litter saprotrophs, and plant pathogens, whereas fungi dispersed in mammal scat are primarily mycorrhizal, soil saprotrophs, and unspecified saprotrophs. We note substantial dispersal of truffles and agaricoid mushrooms by small mammals, and dispersal of agaricoid mushrooms, crusts, and polypores by wind. In addition, we find mammal-dispersed spores are larger than wind-dispersed spores. Our findings suggest that wind- and small-mammal-facilitated dispersal are complementary processes and highlight the role of small mammals in dispersing mycorrhizal fungi, particularly following disturbances such as timber harvest., (© 2023 The Ecological Society of America.)

Enhanced surface mobility is critical in producing stable glasses during physical vapor deposition. In amorphous selenium (a-Se) both the structure and dynamics of the surface can be altered when exposed to above-bandgap light. Here we investigate the effect of light on the properties of vapor-deposited a-Se glasses at a range of substrate temperatures and deposition rates. We demonstrate that deposition both under white light illumination and in the dark results in thermally and kinetically stable glasses. Compared to glasses deposited in the dark, stable a-Se glasses formed under white light have reduced thermal stability, as measured by lower density change, but show significantly improved kinetic stability, measured as higher onset temperature for transformation. While light induces enhanced mobility that penetrates deep into the surface, resulting in lower density during vapor deposition, it also acts to form more networked structures at the surface, which results in a state that is kinetically more stable with larger optical birefringence. We demonstrate that the structure formed during deposition with light is a state that is not accessible through liquid quenching, aging, or vapor deposition in the dark, indicating the formation of a unique amorphous solid state., Competing Interests: The authors declare no competing interest.

Animals are often the primary dispersers of seeds and fungal spores. Specialist species that consume fruits or fungal fruiting bodies (sporocarps) as their main food source are thought to play a more important role in dispersal networks compared to generalist species. However, dispersal networks are often based on occurrence data, overlooking the influence of animal abundance and dispersal effectiveness on network interactions. Using rodent-mycorrhizal fungi networks, we determined how diet specialization and abundance influence the role of rodent species in dispersing fungal spores in temperate forests of northern New Hampshire, USA. We tracked the interactions of five rodent species and 34 fungal taxa over a 3-yr period across hardwood, mixed, and softwood forest stands. We accounted for fluctuations in rodent abundance and differences in the number of spores dispersed in rodent scat. Myodes gapperi, a fungal specialist, dispersed a more diverse spore community than rodent generalists and was consistently the most important disperser in forest types with high fungal availability. Nevertheless, during years when generalist species such as Tamias striatus and Peromyscus maniculatus reached high abundance, their relative importance (species strength) in networks approached or even surpassed that of M. gapperi, particularly in forest types where M. gapperi was less common and fungal availability was low. Increased numbers of generalists enhanced network interaction diversity and the number of fungal taxa dispersed, the timing of which was coincident with seedling establishment following masting, a stage when inoculation by mycorrhizal fungi is critical for growth and survival. Our findings suggest that although specialists play key roles in dispersing mycorrhizal fungal spores, generalists play a heretofore underappreciated role., (© 2020 by the Ecological Society of America.)

Many plant and fungal species use volatile organic compounds (VOCs) as chemical signals to convey information about the location or quality of their fruits or fruiting bodies to animal dispersers. Identifying the environmental factors and biotic interactions that shape fruit selection by animals is key to understanding the evolutionary processes that underpin chemical signaling. Using four Elaphomyces truffle species, we explored the role of fruiting depth, VOC emissions, and protein content in selection by five rodent species. We used stable isotope analysis of nitrogen (δ 15 N) in truffles to estimate fruiting depth, proton-transfer-reaction mass spectrometry to determine volatile emission composition, and nitrogen concentrations to calculate digestible protein of truffles. We coupled field surveys of truffle availability with truffle spore loads in rodent scat to determine selection by rodents. Despite presumably easier access to the shallow fruiting species, E. americanus (0.5-cm depth) and E. verruculosus (2.5-cm depth), most rodents selected for truffles fruiting deeper in the soil, E. macrosporus (4.1-cm depth) and E. bartlettii (5.0-cm depth). The deeper fruiting species had distinct VOC profiles and produced significantly higher quantities of odiferous compounds. Myodes gapperi (southern red-backed vole), a fungal specialist, also selected for truffles with high levels of digestible protein, E. verruculosus and E. macrosporus. Our results highlight the importance of chemical signals in truffle selection by rodents and suggest that VOCs are under strong selective pressures relative to protein rewards. Strong chemical signals likely allow detection of truffles deep within the soil and reduce foraging effort by rodents. For rodents that depend on fungi as a major food source, protein content may also be important in selecting truffles., (© 2019 by the Ecological Society of America.)

Identifying the mechanisms that structure niche breadth and overlap between species is important for determining how species interact and assessing their functional role in an ecosystem. Without manipulative experiments, assessing the role of foraging ecology and interspecific competition in structuring diet is challenging. Systems with regular pulses of resources act as a natural experiment to investigate the factors that influence the dietary niches of consumers. We used natural pulses of mast-fruiting of American beech ( Fagus grandifolia ) to test whether optimal foraging or competition structure the dietary niche breadth and overlap between two congener rodent species ( Peromyscus leucopus and P. maniculatus ), both of which are generalist consumers. We reconstructed diets seasonally over a 2-year period using stable isotope analysis (δ 13 C, δ 15 N) of hair and of potential dietary items and measured niche dynamics using standard ellipse area calculated within a Bayesian framework. Changes in niche breadth were generally consistent with predictions of optimal foraging theory, with both species consuming more beechnuts (a high-quality food resource) and having a narrower niche breadth during masting seasons compared to nonmasting seasons when dietary niches expanded and more fungi (a low-quality food source) were consumed. In contrast, changes in dietary niche overlap were consistent with competition theory, with higher diet overlap during masting seasons than during nonmasting seasons. Overall, dietary niche dynamics were closely tied to beech masting, underscoring that food availability influences competition. Diet plasticity and niche partitioning between the two Peromyscus species may reflect differences in foraging strategies, thereby reducing competition when food availability is low. Such dietary shifts may have important implications for changes in ecosystem function, including the dispersal of fungal spores., Competing Interests: The authors declare no competing interests., (© 2019 The Authors. Ecology and Evolution published by John Wiley & Sons Ltd.)

Colorectal cancer accounts for 11% of all cancer-related deaths in Ireland. With the aim of diagnosing these cancers at an earlier stage, and detecting premalignant lesions, the National Screening Service (NSS) offered a fecal immunochemical test (FIT) to all individuals aged 60 to 69. All individuals in the age range were contacted by post and invited to participate in the programme. Those with a positive FIT result were offered a colonoscopy in an internationally accredited unit. From an eligible population of 488,628, 196,238 individuals participated giving an uptake of 40.2%. Commencing at a FIT threshold of 20 μg Hg/g feces, the positivity rate was 8.6%, which overwhelmed colonoscopy capacity and, thus, the threshold was increased to 45 μg, resulting in an overall 5% positivity rate. A total of 520 individuals had cancer detected (68.3% stage I or II), of which 104 were removed endoscopically (pT1s). Adenomas were present in 54.2% of all colonoscopies, 17.4% deemed high risk. Despite a lower uptake, males were twice as likely to have colorectal cancers as females and had a 59% increased rate of high-risk adenomas diagnosed. Challenges facing the programme include increasing participation, especially among males, and increasing colonoscopy capacity. The ability to alter the sensitivity of FIT to match colonoscopy capacity is a valuable option for such a programme as it ensures that the maximum public health benefit can be achieved within available resources., (©2018 American Association for Cancer Research.)

We describe five new species of Elaphomyces from Bartlett Experimental Forest, New Hampshire, USA ( E. americanus , E. bartlettii , E. macrosporus , E. oreoides , and E. remickii ) and revise the description of a sixth previously published species ( E. verruculosus ). Of the five new species, E. bartlettii and E. remickii are only known from New Hampshire whereas E. americanus, E. macrosporus, and E. oreoides are widely distributed in eastern North America. Elaphomyces verruculosus is the most widespread and abundant Elaphomyces species in eastern North America with a distribution extending from eastern Canada south to northeastern Mexico. All six Elaphomyces species are putatively associated with Tsuga canadensis , a tree species in regional decline. For five of the six Elaphomyces species, we report partially consumed ascomata or rodent fecal samples containing spores, indicating that small mammals play a key role in dispersing these Elaphomyces species and that the Elaphomyces are an important part of the small mammals' diet.

We have built an absolutely calibrated, highly efficient, Bragg crystal spectrometer in von Hamos geometry. This zinc von Hamos spectrometer uses a crystal made from highly oriented pyrolytic graphite that is cylindrically bent along the non-dispersive axis. It is tuned to measure x-ray spectra in the 7-10 keV range and has been designed to be used on a Ten Inch Manipulator for the Omega and OmegaEP target chambers at the Laboratory for Laser Energetics in Rochester, USA. Significant shielding strategies and fluorescence mitigation have been implemented in addition to an imaging plate detector making it well suited for experiments in high-intensity environments. Here we present the design and absolute calibration as well as mosaicity and integrated reflectivity measurements.

The advent of high-intensity lasers enables us to recreate and study the behaviour of matter under the extreme densities and pressures that exist in many astrophysical objects. It may also enable us to develop a power source based on laser-driven nuclear fusion. Achieving such conditions usually requires a target that is highly uniform and spherically symmetric. Here we show that it is possible to generate high densities in a so-called fast-ignition target that consists of a thin shell whose spherical symmetry is interrupted by the inclusion of a metal cone. Using picosecond-time-resolved X-ray radiography, we show that we can achieve areal densities in excess of 300 mg cm(-2) with a nanosecond-duration compression pulse--the highest areal density ever reported for a cone-in-shell target. Such densities are high enough to stop MeV electrons, which is necessary for igniting the fuel with a subsequent picosecond pulse focused into the resulting plasma.

Refluxing of fast electrons generated by high-intensity, short-pulse lasers was investigated by measuring electron-induced Kα x rays from a buried tracer layer. Using planar foils of Au/Cu/CH, the 150-J, 0.7-ps TITAN short-pulse laser was focused on the gold foil to generate fast electrons and the 3-ns, 300-J long pulse beam irradiated on the CH side to create expanding plasma as a conducting medium. By delaying the short-pulse beam timing from the long pulse laser irradiation, the plasma size was varied to change electron refluxing in the target rear. The total yields and two-dimensional images of 8.05-keV Cu-Kα x ray were recorded with an x-ray spectrometer and two monochromatic crystal imagers. The measurements show that the integrated yields decrease by a factor of 10 from refluxing to the nonrefluxing limit. Similar radial profiles of the Kα images in the rear were observed at all delays. Hybrid-particle-in-cell simulations using plasma profiles calculated by a radiation-hydrodynamic code HYDRA agree well with the measured Kα yields. The simulations suggest that conducting plasma with the size of ∼300 μm in the laser direction and ∼600 μm in the lateral direction at the density of 2 × 1020 1/cm3 is sufficiently large to prevent electrons from refluxing in the target. The parameters found in this study can be useful in designing experiments utilizing a Kα x-ray source in refluxing regime or a tracer layer in nonrefluxing regime.

The Bragg angle, rocking curve, and reflection efficiency of a quartz crystal x-ray imager (Miller indices 234) were measured at photon energy of 15.6909 keV, corresponding to the K(α2) line of Zr, using the X15A beamline at the National Synchrotron Light Source at Brookhaven National Laboratory. One flat and three spherically curved samples were tested. The peak reflectivity of the best-performing crystal was determined to be (3.6 ± 0.7) × 10(-4) with a rocking-curve full width at half maximum of 0.09°. The Zr K(α2) emission was imaged from a hot Zr plasma generated by a 10-J multiterawatt laser.

The effect of target material on fast-electron transport is investigated using a high-intensity (0.7 ps, 10(20)  W/cm2) laser pulse irradiated on multilayered solid Al targets with embedded transport (Au, Mo, Al) and tracer (Cu) layers, backed with millimeter-thick carbon foils to minimize refluxing. We consistently observed a more collimated electron beam (36% average reduction in fast-electron induced Cu Kα spot size) using a high- or mid-Z (Au or Mo) layer compared to Al. All targets showed a similar electron flux level in the central spot of the beam. Two-dimensional collisional particle-in-cell simulations showed formation of strong self-generated resistive magnetic fields in targets with a high-Z transport layer that suppressed the fast-electron beam divergence; the consequent magnetic channels guided the fast electrons to a smaller spot, in good agreement with experiments. These findings indicate that fast-electron transport can be controlled by self-generated resistive magnetic fields and may have important implications to fast ignition.

Acceleration and focusing of high-energy proton beams from fast-ignition (FI) -related hemisphere-cone assembled targets have been numerically studied by hybrid particle-in-cell simulations and compared with those from planar-foil and open-hemisphere targets. The whole physical process including the laser-plasma interaction has been self-consistently modeled for 15 ps, at which time the protons reach asymptotic motion. It is found that the achievable focus of proton beams is limited by the thermal pressure gradients in the co-moving hot electrons, which induce a transverse defocusing electric field that bends proton trajectories near the axis. For the advanced hemisphere-cone target, the flow of hot electrons along the cone wall induces a local transverse focusing sheath field, resulting in a clear enhancement in proton focusing; however, it leads to a significant loss of longitudinal sheath potential, reducing the total conversion efficiency from laser to protons.

Emission of energetic protons (maximum energy ∼18 MeV) from the interaction of relativistic intensity laser with a cone-wire target is experimentally measured and numerically simulated with hybrid particle-in-cell code, lsp [D. R. Welch et al., Phys. Plasmas 13, 063105 (2006)]. The protons originate from the wire attached to the cone after the OMEGA EP laser (670 J, 10 ps, 5 × 10^{18} W/cm^{2}) deposits its energy inside the cone. These protons are accelerated from the contaminant layer on the wire surface, and are measured in the radial direction, i.e., in a direction transverse to the wire length. Simulations show that the radial electric field, responsible for the proton acceleration, is excited by three factors, viz., (i) transverse momentum of the relativistic fast electrons beam entering into the wire, (ii) scattering of electrons inside the wire, and (iii) refluxing of escaped electrons by "fountain effect" at the end of the wire. The underlying physics of radial electric field and acceleration of protons is discussed.

A novel time-resolved diagnostic is used to record the critical surface motion during picosecond-scale relativistic laser interaction with a solid target. Single-shot measurements of the specular light show a redshift decreasing with time during the interaction, corresponding to a slowing-down of the hole boring process into overdense plasma. On-shot full characterization of the laser pulse enables simulations of the experiment without any free parameters. Two-dimensional particle-in-cell simulations yield redshifts that agree with the data, and support a simple explanation of the slowing-down of the critical surface based on momentum conservation between ions and reflected laser light.

The effect of increasing prepulse energy levels on the energy spectrum and coupling into forward-going electrons is evaluated in a cone-guided fast-ignition relevant geometry using cone-wire targets irradiated with a high intensity (10(20) W/cm(2)) laser pulse. Hot electron temperature and flux are inferred from Kα images and yields using hybrid particle-in-cell simulations. A two-temperature distribution of hot electrons was required to fit the full profile, with the ratio of energy in a higher energy (MeV) component increasing with a larger prepulse. As prepulse energies were increased from 8 mJ to 1 J, overall coupling from laser to all hot electrons entering the wire was found to fall from 8.4% to 2.5% while coupling into only the 1-3 MeV electrons dropped from 0.57% to 0.03%.

We report on the development and characterization of a zirconium Kα imager for high energy density physics research. The imager consists of a spherically bent quartz crystal operating at 15.7 keV photon energy. We compare the performance of the imager in terms of integrated reflectivity (R(int)) and temperature dependent collection efficiency (η(Te)) to that of the widely used Cu Kα imager. Our collisional-radiative simulations show that the new imager can be reliably used up to 250 eV plasma temperature. Monte Carlo simulations show that for a 25 μm thick tracer layer of zirconium, the contribution to Kα production from photo-pumping is only 2%. We present, for the first time, 2D spatially resolved images of zirconium plasmas generated by a high intensity short pulse laser interacting with Zr solid targets.

Fast electron generation in the presence of coronal plasma in front of a solid target (typically referred to as preformed plasma) in laser-matter interaction in the intensity range of 10(19)-10(21) W/cm(2) is studied in a one-dimensional slab approximation with particle-in-cell (PIC) simulations. Three different preformed plasma density scale lengths of 1, 5, and 15 μm are considered. We report an increase in both mean and maximum energy of generated fast electrons with an increase in the preformed plasma scale length (in the range 1-15 μm). The heating of plasma electrons is predominantly due to their stochastic motion in counterpropagating electromagnetic (EM) waves (incident and reflected waves) and the presence of a longitudinal electric field produced self-consistently inside the preformed plasma. The synergetic effects of this longitudinal electric field and EM waves responsible for the efficient preformed plasma electrons heating are discussed.

The viability of fast-ignition (FI) inertial confinement fusion hinges on the efficient transfer of laser energy to the compressed fuel via multi-MeV electrons. Preformed plasma due to the laser prepulse strongly influences ultraintense laser plasma interactions and hot electron generation in the hollow cone of an FI target. We induced a prepulse and consequent preplasma in copper cone targets and measured the energy deposition zone of the main pulse by imaging the emitted K_{alpha} radiation. Simulation of the radiation hydrodynamics of the preplasma and particle in cell modeling of the main pulse interaction agree well with the measured deposition zones and provide an insight into the energy deposition mechanism and electron distribution. It was demonstrated that a under these conditions a 100 mJ prepulse eliminates the forward going component of approximately 2-4 MeV electrons.

Purpose: Survivin has been shown to be an important mediator of cellular radioresistance in vitro. This study aims to compare survivin expression and apoptosis to histomorphologic responses to neoadjuvant radiochemotherapy (RCT) in rectal cancer., Materials and Methods: Thirty-six pre-treatment biopsies were studied. Survivin mRNA and protein expression plus TUNEL staining for apoptosis was performed. Response to treatment was assessed using a 5-point tumour regression grade., Results: Survivin expression was not found to be predictive of response to RCT (p = NS). In contrast, spontaneous apoptosis was significantly (p = 0.0051) associated with subsequent response to RCT. However, no association between survivin expression and levels of apoptosis could be identified., Conclusions: This in vivo study failed to support in vitro studies showing an association between survivin and response to chemotherapy and radiation therapy. These results caution against the translation of the in vitro properties of survivin into a clinical setting.

The energy transport in cone-guided low- Z targets has been studied for laser intensities on target of 2.5x10(20) W cm(-2). Extreme ultraviolet (XUV) imaging and transverse optical shadowgraphy of the rear surfaces of slab and cone-slab targets show that the cone geometry strongly influences the observed transport patterns. The XUV intensity showed an average spot size of 65+/-10 microm for slab targets. The cone slabs showed a reduced spot size of 44+/-10 microm. The shadowgraphy for the aforementioned shots demonstrate the same behavior. The transverse size of the expansion pattern was 357+/-32 microm for the slabs and reduced to 210+/-30 microm. A transport model was constructed which showed that the change in transport pattern is due to suppression of refluxing electrons in the material surrounding the cone.

A dual-channel, curved-crystal spectrograph was designed to measure time-integrated x-ray spectra in the approximately 1.5 to 2 keV range (6.2-8.2 A wavelength) from small-mass, thin-foil targets irradiated by the VULCAN petawatt laser focused up to 4x10(20) W/cm(2). The spectrograph consists of two cylindrically curved potassium-acid-phthalate crystals bent in the meridional plane to increase the spectral range by a factor of approximately 10 compared to a flat crystal. The device acquires single-shot x-ray spectra with good signal-to-background ratios in the hard x-ray background environment of petawatt laser-plasma interactions. The peak spectral energies of the aluminum He(alpha) and Ly(alpha) resonance lines were approximately 1.8 and approximately 1.0 mJ/eV sr (approximately 0.4 and 0.25 J/A sr), respectively, for 220 J, 10 ps laser irradiation.

Experimental data [F. N. Beg, Phys. Plasmas 4, 447 (1997)10.1063/1.872103] indicate that for intense short-pulse laser-solid interactions at intensities up to 5 x 10(18) W cm(-2) the hot-electron temperature proportional, variant(Ilambda(2)) (1/3). A fully relativistic analytic model based on energy and momentum conservation laws for the laser interaction with an overdense plasma is presented here. A general formula for the hot-electron temperature is found that closely agrees with the experimental scaling over the relevant intensity range. This scaling is much lower than ponderomotive scaling. Examination of the electron forward displacement compared to the collisionless skin depth shows that electrons experience only a fraction of a laser-light period before being accelerated forward beyond the laser light's penetration region. Inclusion of backscattered light in a modified model indicates that light absorption approaches 80%-90% for intensity >10(19) W cm(-2).

Three independent methods (extreme ultraviolet spectroscopy, imaging at 68 and 256 eV) have been used to measure planar target rear surface plasma temperature due to heating by hot electrons. The hot electrons are produced by ultraintense laser-plasma interactions using the 150 J, 0.5 ps Titan laser. Soft x-ray spectroscopy in the 50-400 eV region and imaging at the 68 and 256 eV photon energies give a planar deuterated carbon target rear surface pre-expansion temperature in the 125-150 eV range, with the rear plasma plume averaging a temperature approximately 74 eV.

A Bremsstrahlung spectrometer using k-edge and differential filtering has been used with image plate dosimeters to measure the x-ray fluence from short-pulse laser/target interactions. An electron spectrometer in front of the Bremsstrahlung spectrometer deflects electrons from the x-ray line of sight and simultaneously measures the electron spectrum. The response functions were modeled with the Monte Carlo code INTEGRATED TIGER SERIES 3.0 and the dosimeters calibrated with radioactive sources. An electron distribution with a slope temperature of 1.3 MeV is inferred from the Bremsstrahlung spectra.

The ignition concept for electron fast ignition inertial confinement fusion requires sufficient energy be transferred from an approximately 20 ps laser pulse to the compressed fuel via approximately MeV electrons. We have assembled a suite of diagnostics to characterize such transfer, simultaneously fielding absolutely calibrated extreme ultraviolet multilayer imagers at 68 and 256 eV; spherically bent crystal imagers at 4.5 and 8 keV; multi-keV crystal spectrometers; MeV x-ray bremmstrahlung, electron and proton spectrometers (along the same line of sight), and a picosecond optical probe interferometer. These diagnostics allow careful measurement of energy transport and deposition during and following the laser-plasma interactions at extremely high intensities in both planar and conical targets. Together with accurate on-shot laser focal spot and prepulse characterization, these measurements are yielding new insights into energy coupling and are providing critical data for validating numerical particle-in-cell (PIC) and hybrid PIC simulation codes in an area crucial for fast ignition and other applications. Novel aspects of these diagnostics and how they are combined to extract quantitative data on ultrahigh intensity laser-plasma interactions are discussed.

Measurements of plasma temperature at the rear surface of foil targets due to heating by hot electrons, which were produced in short pulse high intensity laser matter interactions using the 150 J, 0.5 ps Titan laser, are reported. Extreme ultraviolet (XUV) imaging at 256 and 68 eV energies is used to determine spatially resolved target rear surface temperature patterns by comparing absolute intensities to radiation hydrodynamic modeling. XUV mirrors at these two energies were absolutely calibrated at the Advanced Light Source at the Lawrence Berkeley Laboratory. Temperatures deduced from both imagers are validated against each other within the range of 75-225 eV.

Although uncommon and often asymptomatic, portal venous thrombosis can have catastrophic consequences for the individual it afflicts, particularly when the process propagates to involve the superior mesenteric vein. Familiarity with the condition's pathogenesis and presentation however permits early diagnosis and allows aggressive conservative management to achieve a successful outcome. Here we describe the successful outcome of such management for a 42-year-old male patient who developed this condition spontaneously.

The heating of solid targets irradiated by 5 x 10(20) W cm(-2), 0.8 ps, 1.05 microm wavelength laser light is studied by x-ray spectroscopy of the K-shell emission from thin layers of Ni, Mo, and V. A surface layer is heated to approximately 5 keV with an axial temperature gradient of 0.6 microm scale length. Images of Ni Ly(alpha) show the hot region has 100 G bar light pressure compresses the preformed plasma and drives a shock into the solid, heating a thin layer.

Acute abdominal pain in haemophiliacs should be approached as haemorrhage until proven otherwise. With advancements in factor repletion and coagulopathic management a conservative approach should be considered. We describe a case of double colo-colonic intussusception lead by an intramural haematoma occurring spontaneously and resolving with conservative management in a young haemophiliac. This demonstrates that intussusception in these cases may be transient, and does not require surgical intervention.

Although commonly detectable in patients with cirrhosis, rectal varices only infrequently cause significant hematochezia (0.5-3.6%). While they may be expected to resolve with treatment of the concomitant portal hypertension, there is currently no standardized approach to their management in isolation. Therefore many authorities recommend transjugular intrahepatic portosystemic shunting (TIPS) as a means of alleviating otherwise recalcitrant bleeding. Conceptually, however, rectal varices should be as amenable to local therapies as are their counterparts occurring at the esophagogastric junction. In this report, we describe the use of endoscopic banding per ano to alleviate significant rectal bleeding in a patient with poorly controlled portal hypertension. This allowed medical optimisation so that the underlying pathology could be controlled without recourse to TIPS or other means of creating a formal portosystemic shunt.

Introduction: Those who have surmounted the learning curve for laparoscopic colorectal resection state that considerable numbers of highly selected cases should comprise a department's early experience to ensure reliability of technique before routine implementation. The objective of this study was to determine how this advice may interrupt case flow., Methods: Details on all colorectal operations performed in a single institution over a 4-year period were gleaned from a prospectively maintained database. Patient profiles were scrutinised to identify how the application of various published exclusion criteria would impact upon the theoretical completion rates of our proposed learning curve., Results: In total, 317 colorectal resections were performed; 259 operations were for adenocarcinoma (including 100 rectal tumours) while 58 were for benign disease. Of those with malignancy, 25(10%) were obese, 61(24%) had previous intra-abdominal surgery, while 52(20%) were aged over 80 years and 60(23%) were ASA (3/4). Strictest exclusion criteria would halve the number of cases to be commenced laparoscopically. A specialist registrar rotating through the department would have case exposure cut from a mean of 33 to 11 in 6 months under this regimen. Prioritising benign cases in the initial experience as has been recommended by certain groups would mean that, at most, 1.2 cases would be performed every 4 weeks during the learning period., Conclusion: Although our caseload seems sufficient to allow the acquisition of expertise in a timely fashion, procedural flow would be markedly interrupted by stringent pre-selection. A low threshold for initiating the procedure laparoscopically seems a pragmatic way of ensuring departmental confidence through familiarity.

Objective: We investigated whether proteomic analysis of the low molecular weight region of the serum proteome could predict histologic response of locally advanced rectal cancer to neoadjuvant radiochemotherapy (RCT)., Summary Background Data: Proteomic analysis of serum is emerging as a powerful new modality in cancer, in terms of both screening and monitoring response to treatment. No study has yet assessed its ability to predict and monitor the response of rectal cancer to RCT., Methods: Sequential serum samples from 20 patients undergoing RCT were prospectively collected. Time points sampled were as follows: pretreatment, 24/48 hours, 1 week, 2 weeks, 3 weeks, 5 weeks (last day of RCT), and presurgery. Response to treatment was measured using a 5-point tumor regression grade (TRG) based on the degree of residual tumor to fibrosis. All serum samples were analyzed in duplicate using surface-enhanced laser desorption/ionization-time of flight mass spectrometry (SELDI-TOF-MS). Support vector machine (SVM) analysis of spectra was used to generate a predictive algorithm for each time point based on proteins that were maximally differentially expressed between good and poor responders. This algorithm was then tested using leave-one-out cross validation., Results: In total, 230 spectra were generated representing all available time points from 9 good responders (TRG 1+2) and 11 poor responders (TRG 3-5). SVM analysis indicated that changes within the serum proteome at the 24/48 hours time point into treatment provided optimal classification accuracy. In more detail, a cohort of 14 protein peaks were identified that collectively differentiated between good and poor responders, with 87.5% sensitivity and 80% specificity., Conclusions: Serum proteomic analysis may represent an early response predictor in multimodal treatment regimens of rectal cancer. These data suggest that this novel, minimally invasive modality may be a useful adjunct in the multimodal management of rectal cancer, and in the design of future clinical trials.

Protons accelerated by a picosecond laser pulse have been used to radiograph a 500 microm diameter capsule, imploded with 300 J of laser light in 6 symmetrically incident beams of wavelength 1.054 microm and pulse length 1 ns. Point projection proton backlighting was used to characterize the density gradients at discrete times through the implosion. Asymmetries were diagnosed both during the early and stagnation stages of the implosion. Comparison with analytic scattering theory and simple Monte Carlo simulations were consistent with a 3+/-1 g/cm3 core with diameter 85+/-10 microm. Scaling simulations show that protons>50 MeV are required to diagnose asymmetry in ignition scale conditions.

Purpose: To determine the utility of COX-2 expression as a response predictor for patients with rectal cancer who are undergoing neoadjuvant radiochemotherapy (RCT)., Methods and Materials: Pretreatment biopsies (PTB) from 49 patients who underwent RCT were included. COX-2 and proliferation in PTB were assessed by immunohistochemistry (IHC) and apoptosis was detected by TUNEL stain. Response to treatment was assessed by a 5-point tumor-regression grade (TRG) based on the ratio of residual tumor to fibrosis., Results: Good response (TRG 1+2), moderate response (TRG 3), and poor response (TRG 4+5) were seen in 21 patients (42%), 11 patients (22%), and 17 patients (34%), respectively. Patients with COX-2 overexpression in PTB were more likely to demonstrate moderate or poor response (TRG 3+4) to treatment than were those with normal COX-2 expression (p=0.026, chi-square test). Similarly, poor response was more likely if patients had low levels of spontaneous apoptosis in PTBs (p=0.0007, chi-square test)., Conclusions: COX-2 overexpression and reduced apoptosis in PTB can predict poor response of rectal cancer to RCT. As COX-2 inhibitors are commercially available, their administration to patients who overexpress COX-2 warrants assessment in clinical trials in an attempt to increase overall response rates.

Aims: The prediction of sensitivity and resistance to neoadjuvant therapy has great potential value for many tumour sites. A neoadjuvant regimen is increasingly the gold standard in rectal cancer management and the aim of this review was to highlight predictive markers currently assessed and evaluate their clinical utility., Methods: A systematic search of Medline was conducted using the following keywords 'colorectal', 'neoadjuvant', 'molecular', 'predict' and 'radiotherapy'. Original manuscripts from all relevant listings were sourced. These were hand searched for further articles of relevance., Results: Conventional indices including tumour stage and grade were unable to predict histological response. Immunohistochemical assessment of P53 gene, Bcl 2, Bax and microsatellite instability are of no predictive value. Studies utilising molecular response predictors from archival pre-treatment tumour tissues have identified several promising predictive markers including p21, spontaneous apoptosis and direct sequencing of the p53 gene. Global gene expression from fresh pre-treatment tissue using cDNA microarray has only recently been assessed but identified expression differences between 54 genes and was able to predict response with 78% sensitivity and 86% specificity., Conclusions: Currently there are no clinically useful predictors of response based on standard pathological assessment and immunocytochemistry. Direct gene sequencing of p53, studies of apoptosis and global gene sequencing may hold promise.

The development of ultra-intense lasers has facilitated new studies in laboratory astrophysics and high-density nuclear science, including laser fusion. Such research relies on the efficient generation of enormous numbers of high-energy charged particles. For example, laser-matter interactions at petawatt (10(15) W) power levels can create pulses of MeV electrons with current densities as large as 10(12) A cm(-2). However, the divergence of these particle beams usually reduces the current density to a few times 10(6) A cm(-2) at distances of the order of centimetres from the source. The invention of devices that can direct such intense, pulsed energetic beams will revolutionize their applications. Here we report high-conductivity devices consisting of transient plasmas that increase the energy density of MeV electrons generated in laser-matter interactions by more than one order of magnitude. A plasma fibre created on a hollow-cone target guides and collimates electrons in a manner akin to the control of light by an optical fibre and collimator. Such plasma devices hold promise for applications using high energy-density particles and should trigger growth in charged particle optics.