Bright quasi-phase-matched soft-x-ray harmonic radiation from argon ions

Selective enhancement (> 10(3)) of harmonics extending to the water window (similar to 4 nm) generated in an argon gas filled straight bore capillary waveguide is demonstrated. This enhancement is in good agreement with modeling which indicates that multimode quasi-phase-matching is achieved by rapid axial intensity modulations caused by beating between the fundamental and higher-order capillary modes. Substantial pulse energies (> 10 nJ per pulse per harmonic order) at wavelengths beyond the carbon K edge (similar to 4.37 nm, similar to 284 eV) up to similar to 360 eV are observed from argon ions for the first time.

Soft X-ray harmonic comb from relativistic electron spikes

We demonstrate a new high-order harmonic generation mechanism reaching the "water window" spectral region in experiments with multiterawatt femtosecond lasers irradiating gas jets. A few hundred harmonic orders are resolved, giving mu J/sr pulses. Harmonics are collectively emitted by an oscillating electron spike formed at the joint of the boundaries of a cavity and bow wave created by a relativistically self-focusing laser in underdense plasma. The spike sharpness and stability are explained by catastrophe theory. The mechanism is corroborated by particle-in-cell simulations.

Study of reliability of fibre Bragg grating fibre optic strain sensors for field-test applications

In this paper, the reliability and thus the suitability of optical fibre strain sensors for surface strain measurement in concrete structures was investigated. Two different configurations of optical strain sensors were used each having different mountings making them suitable for different uses in various structures. Due to the very limited time available to install the sensors and take result, commercially packaged sensors were used. In the tests carried out each sensor was mounted onto a concrete beam which was then subjected to a range of known and calibrated loadings. The performance of the optical strain sensors thus evaluated was compared with the results of conventional techniques. This comparison allows for selecting the best performing combination of sensor/mounting, i.e. long-gauge sensor with mounts bolted to threaded rods glued into the concrete for use in future work in a field test where a limited time window was available for installation, testing and post-test demounting. © 2012 Elsevier B.V.

Relativistic High Harmonic Generation In Gas Jet Targets

We experimentally demonstrate a new regime of high-order harmonic generation by relativistic-irradiance lasers in gas jet targets. Bright harmonics with both odd and even orders, generated by linearly as well as circularly polarized pulses, are emitted in the forward direction, while the base harmonic frequency is downshifted. A 9 TW laser generates harmonics up to 360 eV, within the 'water window' spectral region. With a 120 TW laser producing 40 uJ/sr per harmonic at 120 eV, we demonstrate the photon number scalability. The observed harmonics cannot be explained by previously suggested scenarios. A novel high-order harmonics generation mechanism [T. Zh. Esirkepov et al., AIP Proceedings, this volume], which explains our experimental findings, is based on the phenomena inherent in the relativistic laser - underdense plasma interactions (self-focusing, cavity evacuation, and bow wave generation), mathematical catastrophe theory which explains formation of electron density singularities (cusps), and collective radiation due to nonlinear oscillations of a compact charge.

Palaeoenvironmental changes since the Last Glacial Maximum: Patterns, timing and dynamics throughout South America

The vast diversity of present vegetation and environments that occur throughout South America (12°N to 56°S) is the result of diverse processes that have been operating and interacting at different spatial and temporal scales. Global factors, such as the concentration of CO2 in the atmosphere, may have been significant for high altitude vegetation during times of lower abundance, while lower sea levels of glacial stages potentially opened areas of continental shelf for colonisation during a substantial portion of the Quaternary. Latitudinal variation in orbital forcing has operated on a regional scale. The pace of climate change in the tropics is dominated by precessional oscillations of c. 20 kyr, while the high latitudes of the south are dominated by obliquity oscillations of c. 40 kyr. In particular, seasonal insolation changes forced by precessional oscillations must have had important consequences for the distribution limits of species, with potentially different effects depending on the latitude. The availability of taxa, altitude and human impact, among other events, have locally influenced the environments. Disentangling the different forcing factors of environmental change that operate on different timescales, and understanding the underlying mechanisms leads to considerable challenges for palaeoecologists. The papers in this Special Issue present a selection of palaeoecological studies throughout South America on vegetation changes and other aspects of the environment, providing a window on the possible complexity of the nature of transitions and timings that are potentially available.

Public health interventions in midwifery: a systematic review of systematic reviews

Background: Maternity care providers, particularly midwives, have a window of opportunity to influence pregnant women about positive health choices. This aim of this paper is to identify evidence of effective public health interventions from good quality systematic reviews that could be conducted by midwives.

Methods: Relevant databases including MEDLINE, Pubmed, EBSCO, CRD, MIDIRS, Web of Science, The Cochrane Library and Econlit were searched to identify systematic reviews in October 2010. Quality assessment of all reviews was conducted.

Results: Thirty-six good quality systematic reviews were identified which reported on effective interventions. The reviews were conducted on a diverse range of interventions across the reproductive continuum and were categorised under: screening; supplementation; support; education; mental health; birthing environment; clinical care in labour and breast feeding. The scope and strength of the review findings are discussed in relation to current practice. A logic model was developed to provide an overarching framework of midwifery public health roles to inform research policy and practice.

Conclusions: This review provides a broad scope of high quality systematic review evidence and definitively highlights the challenge of knowledge transfer from research into practice. The review also identified gaps in knowledge around the impact of core midwifery practice on public health outcomes and the value of this contribution. This review provides evidence for researchers and funders as to the gaps in current knowledge and should be used to inform the strategic direction of the role of midwifery in public health in policy and practice.

Censoring the 1970s: The BBFC and the Decade that Taste Forgot

This book is a study of the British Board of Film Censors in the 1970s. In permitting and refusing specific material to be shown on cinema screens the BBFC were dictating patterns of taste and helping shape and determine notions of acceptability. Contentious and controversial texts like A Clockwork Orange (1971), Straw Dogs (1971) The Devils (1971) and Life of Brian (1979) have been used to draw attention to the way in which the BBFC operated in the 1970s. While it is true to say that these films encountered major censorship problems, what of the hundreds of other films which were being classified at the same time? Did all films struggle with the British censors in this period, and can these famous examples be fitted into broader patterns of censorship policy and practice?

In studying over 250 film files from the BBFC archive, this work reveals how 1970s films such as Vampire Circus (1971), Confessions of a Window Cleaner (1974) and Carry on Emmannuelle (1978) also ran in to trouble with the film censor. This work explores the complex process of negotiation and compromise which affected all film submissions in the 1970s and the way in which the BBFC actively, and often sympathetically, negotiated with film directors, producers and distributors to assign the correct category to each film. The lack of any defined formal censorship policy in this period allowed the BBFC to work alongside the film industry and push cultural, social and artistic boundaries; however it also left the Board open to accusations of favouritism, subjectivity and personal bias.

This work is not simply a study of controversial films and contentious issues, but rather engages with wider issues of changing permission, legal struggles, the influence of the media and the legislative and governmental controls which both helped and hindered the BBFC in this important post-war decade. The approach used within this work focuses on historical and archival research, making it importantly inter-textual and offering a great deal to scholars from a number of associated disciplines, including history, social policy, media and communications and politics.

The institutionalisation of the European Internal Cross-Border Co-operation Policy: A first appraisal

In the space of just 20 years, internal cross-border co-operation (CBC) has transformed from a marginal issue for European integration into an important strand of the third objective of European Union's (EU's) regional policy. How might this process of transformation be explained? This study intends to reconstruct the chronology of its development through interviews and use of archival material. The emergence of the current CBC policy was not, we argue, an inevitable solution to the problem of border management but, rather, the result of a struggle between the actors of that policy sub-system. The dramatic rise of CBC is the result of a series of factors that originated with the signing of the Single European Act in 1986. The construction of CBC as a set of problems and solutions by a network of policy actors at the margins of the EU through a series of technical reports, together with the policy window opened by the appointment of the Delors Commission, allowed the launching of an innovative CBC policy which has consolidated over time.

Coherent synchrotron emission from electron nanobunches formed in relativistic laser-plasma interactions

Extreme ultraviolet (XUV) and X-ray harmonic spectra produced by intense laser-solid interactions have, so far, been consistent with Doppler upshifted reflection from collective relativistic plasma oscillations-the relativistically oscillating mirror mechanism(1-6). Recent theoretical work, however, has identified a new interaction regime in which dense electron nanobunches are formed at the plasma-vacuum boundary resulting in coherent XUV radiation by coherent synchrotron emission(7,8) (CSE). Our experiments enable the isolation of CSE from competing processes, demonstrating that electron nanobunch formation does indeed occur. We observe spectra with the characteristic spectral signature of CSE-a slow decay of intensity, I, with high-harmonic order, n, as I(n) proportional to n(-1.62) before a rapid efficiency rollover. Particle-in-cell code simulations reveal how dense nanobunches of electrons are periodically formed and accelerated during normal-incidence interactions with ultrathin foils and result in CSE in the transmitted direction. This observation of CSE presents a route to high-energy XUV pulses(7,8) and offers a new window on understanding ultrafast energy coupling during intense laser-solid density interactions.

Oxygen isotopes from Phorcus (Osilinus) turbinatus shells as a proxy for sea surface temperature in the central Mediterranean: a case study from Malta.

The marine topshell, Phorcus (Osilinus) turbinatus, is a common component of many archaeological sites in the Mediterranean. This species has been successfully used as a palaeoclimate proxy in Italy. To test whether d18O from P. turbinatus shells can serve as a reliable palaeoclimate archive for other regions of the Mediterranean, we collected live P. turbinatus from the northeast coast of Malta each month for a year. The d18OSHELL values of the outermost growth increments of these live-collected shells ranged between-0.4 and+2.4‰. These values correspond to growing temperatures calculated from shell edge d18O of between 15 °C and 27 °C. Calculated shell edge sea surface temperatures are highly correlated with instrumental records of sea surface temperature recorded over the period of collection. The individuals analysed for this study are smaller than P. turbinatus from populations studied elsewhere in the Mediterranean. Nonetheless, d18OSHELL provides a robust record of sea surface temperatures, suggesting that smaller/younger shells in archaeological deposits can still provide reliable palaeothermometry records. This study extends the upper growth limit P. turbinatus by 2 °C compared with the previous studies of P. turbinatus in the Mediterranean and suggests that, contrary to the previous studies, growth shutdown does not occur in all P. turbinatus when sea surface temperatures exceed 25 °C. This may reflect the higher sample resolution that can be obtained from smaller/faster growing shells, or it may reflect actual higher growth tolerances of P. turbinatus populations in Malta. By showing that P. turbinatus precipitate their shells in d18O equilibrium with surrounding sea water, this study reinforces the potential for the stable isotope chemistry of P. turbinatus shells preserved in Mediterranean archaeological sites to provide a window into the climate and seasonality regimes of the past.

Gendered Spaces and Wounded Bodies: Yamina Benguigui's 'Inch'Allah Dimanche'

Yamina Benguigui is a pioneer in the representation of Maghrebi immigration to France, and has produced a number of works of documentary and fictional film on the subject. This article discusses her fictional film Inch'Allah dimanche (2001). The film portrays the trajectory of a young woman, Zouina, who takes her children and mother-in-law to join her husband in France. The film is unique for its close focus on the space of the home, and the negotiation of gendered spaces within the strict confines set by Zouina's husband. In this article, I consider Zouina's tentative steps towards emancipation from these confines, focusing on preconceived notions of gendered spaces across different cultures. I consider possible interpretations of the final moment of wounding in the film, in which Zouina breaks through a window with her bare hands, destroying the barrier between the interior, private space of the home and the exterior, public space of the street.

Editorial–Both Sides Now

Competition law is fun. As a noted expert consultant told one of us:'Don't tell my spouse, but I'd work on these cases for the sheer joy of it.'The facts, the issues, the window into economies and legal systems--it does not get much better than this. Not surprisingly,
then, competition law academic seminars are also fun. At their best, they present opportunities for energized students to engage with scholars and wrestle with cutting edge issues in this particularly interesting field.

The efficacy of SMART Arm training early after stroke for stroke survivors with severe upper limb disability:a protocol for a randomised controlled trial

Recovery of upper limb function after stroke is poor. The acute to subacute phase after stroke is the optimal time window to promote the recovery of upper limb function. The dose and content of training provided conventionally during this phase is however, unlikely to be adequate to drive functional recovery, especially in the presence of severe motor disability. The current study concerns an approach to address this shortcoming, through evaluation of the SMART Arm, a non-robotic device that enables intensive and repetitive practice of reaching by stroke survivors with severe upper limb disability, with the aim of improving upper limb function. The outcomes of SMART Arm training with or without outcome-triggered electrical stimulation (OT-stim) to augment movement and usual therapy will be compared to usual therapy alone.

Parameter Optimization on Laser Welding of NiTi Wires by Taguchi Method

In this research, a preliminary study was done to find out the initial parameter window to obtain the full-penetrated NiTi weldment. A L27 Taguchi experiment was then carried out to statistically study the effects of the welding parameters and their possible interactions on the weld bead aspect ratio (or penetration over fuse-zone width ratio), and to determine the optimized parameter settings to produce the full-penetrated weldment with desirable aspect ratio. From the statistical results in the Taguchi experiment, the laser mode was found to be the most important factor that substantially affects the aspect ratio. Strong interaction between the power and focus position was found in the Taguchi experiment. The optimized weldment was mainly of columnar dendritic structure in the weld zone (WZ), while the HAZ exhibited equiaxed grain structure. The XRD and DSC results showed that the WZ remained the B2 austenite structure without any precipitates, but with a significant decrease of phase transformation temperatures. The results in the micro-hardness and tensile tests indicated that the mechanical properties of NiTi were decreased to a certain extent after fibre laser welding.

Statistically-constrained shallow text marking:Techniques, evaluation paradigm and results

We present three natural language marking strategies based on fast and reliable shallow parsing techniques, and on widely available lexical resources: lexical substitution, adjective conjunction swaps, and relativiser switching. We test these techniques on a random sample of the British National Corpus. Individual candidate marks are checked for goodness of structural and semantic fit, using both lexical resources, and the web as a corpus. A representative sample of marks is given to 25 human judges to evaluate for acceptability and preservation of meaning. This establishes a correlation between corpus based felicity measures and perceived quality, and makes qualified predictions. Grammatical acceptability correlates with our automatic measure strongly (Pearson's r = 0.795, p = 0.001), allowing us to account for about two thirds of variability in human judgements. A moderate but statistically insignificant (Pearson's r = 0.422, p = 0.356) correlation is found with judgements of meaning preservation, indicating that the contextual window of five content words used for our automatic measure may need to be extended. © 2007 SPIE-IS&T.