On Site

Contemporary debates on the transformation of building methods, the structure of the building industry, and the introduction of new technologies (informational, material and structural) in professional literature and in the architectural humanities tend to ignore the realities of work on construction sites. This follows a long history of failure to recognise the importance of workers’ experience and knowledge of building as a process by the key professions in the industry. The absence of the working process in accounts of historical development is exacerbated by abstract reflection on building know-how, categories of expertise, and the structure of the industry, when these are not supported by direct observation and engagement with building work and workers. Key assumptions about the relation between structural and technological changes in the industry and the knowledge, skills, composition, and requirements of the workforce can be challenged by paying attention to day-to-day activities and conditions of site work

The Origin of Episodic Accretion Bursts in the Early Stages of Star Formation

We study numerically the evolution of rotating cloud cores, from the collapse of a magnetically supercritical core to the formation of a protostar and the development of a protostellar disk during the main accretion phase. We find that the disk quickly becomes unstable to the development of a spiral structure similar to that observed recently in AB Aurigae. A continuous infall of matter from the protostellar envelope makes the protostellar disk unstable, leading to spiral arms and the formation of dense protostellar/protoplanetary clumps within them. The growing strength of spiral arms and ensuing redistribution of mass and angular momentum creates a strong centrifugal disbalance in the disk and triggers bursts of mass accretion during which the dense protostellar/protoplanetary clumps fall onto the central protostar. These episodes of clump infall may manifest themselves as episodes of vigorous accretion rate (\ge 10^{-4} M_sun/yr) as is observed in FU Orionis variables. Between these accretion bursts, the protostar is characterized by a low accretion rate (< 10^{-6} M_sun/yr). During the phase of episodic accretion, the mass of the protostellar disk remains less than or comparable to the mass of the protostar.Comment: 5 pages, 2 figures, accepted for publication in ApJ

Can guidelines improve referral to elective surgical specialties for adults? A systematic review

Aim To assess effectiveness of guidelines for referral for elective surgical assessment. Method Systematic review with descriptive synthesis. Data sources Medline, EMBASE, CINAHL and Cochrane database up to 2008. Hand searches of journals and websites. Selection of studies Studies evaluated guidelines for referral from primary to secondary care, for elective surgical assessment for adults. Outcome measures Appropriateness of referral (usually measured as guideline compliance) including clinical appropriateness, appropriateness of destination and of pre-referral management (eg, diagnostic investigations), general practitioner knowledge of referral appropriateness, referral rates, health outcomes and costs. Results 24 eligible studies (5 randomised control trials, 6 cohort, 13 case series) included guidelines from UK, Europe, Canada and the USA for referral for musculoskeletal, urological, ENT, gynaecology, general surgical and ophthalmological conditions. Interventions varied from complex (“one-stop shops”) to simple guidelines. Four randomized control trials reported increases in appropriateness of pre-referral care (diagnostic investigations and treatment). No evidence was found for effects on practitioner knowledge. Mixed evidence was reported on rates of referral and costs (rates and costs increased, decreased or stayed the same). Two studies reported on health outcomes finding no change. Conclusions Guidelines for elective surgical referral can improve appropriateness of care by improving prereferral investigation and treatment, but there is no strong evidence in favour of other beneficial effects

Language Independent Gender Identification Through Keystroke Analysis

Purpose – In this work we investigate the feasibility of iden tifying the gender of an author by measuring the keystroke duration when typing a message. Design/methodology/approach – Three classifiers were constructed and tested. We empirically evaluated the effectiveness of the classifiers by using empirical data. We used primary data as well as a publicly available dataset containing keystrokes from a diff erent language to validate the language independence assumption. Findings – The results of this work indicate that it is possible to identify the gender of an author by analyzing keystroke durations with a probability of success in the region of 70%. Research limitations/implications – The proposed approach was validated with a limited number of participants and languages, yet the statistical tests show the significance of the results. However, t his approach will be further tested with other languages. Practical implications – Having the ability to identify the gender of an aut hor of a certain piece of text has value in digital forensics, as the proposed method will be a source of circumstantial evidence for “putting fingers on keyboard” and for arbitrating cases where the true origin of a message needs to be identified. Social implications – If the proposed method is included as part of a text composing system (such as email, and instant messaging applications) it could increase trust toward the applications that use it and may also work as a deterrent for crimes involving forgery. Originality/value – The proposed approach combines and adapts techniques from the domains of biometric authentication and data classification

Nod1 signaling overcomes resistance of S. pneumoniae to opsonophagocytic killing

Airway infection by the Gram-positive pathogen Streptococcus pneumoniae (Sp) leads to recruitment of neutrophils but limited bacterial killing by these cells. Co-colonization by Sp and a Gram-negative species, Haemophilus influenzae (Hi), provides sufficient stimulus to induce neutrophil and complement-mediated clearance of Sp from the mucosal surface in a murine model. Products from Hi, but not Sp, also promote killing of Sp by ex vivo neutrophil-enriched peritoneal exudate cells. Here we identify the stimulus from Hi as its peptidoglycan. Enhancement of opsonophagocytic killing was facilitated by signaling through nucleotide-binding oligomerization domain-1 (Nod1), which is involved in recognition of γ-D-glutamyl-meso-diaminopimelic acid (meso-DAP) contained in cell walls of Hi but not Sp. Neutrophils from mice treated with Hi or compounds containing meso-DAP, including synthetic peptidoglycan fragments, showed increased Sp killing in a Nod1-dependent manner. Moreover, Nod1-/- mice showed reduced Hi-induced clearance of Sp during co-colonization. These observations offer insight into mechanisms of microbial competition and demonstrate the importance of Nod1 in neutrophil-mediated clearance of bacteria in vivo

Signatures of Pseudoscalar Photon Mixing in CMB Radiation

We model the effect of photon and ultra-light pseudoscalar mixing on the propagation of electromagnetic radiation through the extragalactic medium. The medium is modelled as a large number of magnetic domains, uncorrelated with one another. We obtain an analytic expression for the different Stokes parameters in the limit of small mixing angle. The different Stokes parameters are found to increase linearly with the number of domains. We also verify this result by direct numerical simulations. We use this formalism to estimate the effect of pseudoscalar-photon mixing on the Cosmic Microwave Background (CMB) polarization. We impose limits on the model parameters by the CMB observations. We find that the currently allowed parameter range admits a CMB circular polarization up to order $10^{-7}$.Comment: 17 pages, 5 figure

Telling donor-conceived children about their conception: Evaluation of the use of the Donor Conception Network children's books

If parents have used donated gametes, it is a personal choice whether they disclose to their children. For those that do, there is, however, little advice on how to tell their children. The Donor Conception Network (DCN) has made a series of books to help parents disclose. This study evaluated parents’ experience of using these books. An online survey with both quantitative and qualitative questions was used. The DCN membership and social media were used to publicize the survey, and 108 responses were analysed. At the time of conception, the parents’ family types were mainly mother and father (56.5%) and solo mothers (36.1%). The method of conception was mainly donor spermatozoa (55.6%) followed by donor egg (38.0%), double donation (8.3%) and one case of surrogacy. Most parents had read the book to their children before 2 years of age (76.9%). Before reading the books, some of the parents had some confidence in telling (43.5%) or were very confident in telling (30.6%). After reading the books, 60.2% reported having much more confidence in telling. Most parents felt their children had no understanding (76.8%) or only some understanding (22.3%) of donor conception before reading the books. After reading the books most parents felt their children's understanding had increased (71.3%). Most parents felt that reading the books had given them more confidence in using donor conception language (90.7%). The use of books to tell children about their conception may be a useful resource for parents wishing to be open with their children

Alignments in quasar polarizations: pseudoscalar-photon mixing in the presence of correlated magnetic fields

We investigate the effects of pseudoscalar-photon mixing on electromagnetic radiation in the presence of correlated extragalactic magnetic fields. We model the Universe as a collection of magnetic domains and study the propagation of radiation through them. This leads to correlations between Stokes parameters over large scales and consistently explains the observed large-scale alignment of quasar polarizations at different redshifts within the framework of the big bang model.Comment: 12 pages, 5 figures, version published in PR

Optimization of the reverse transcriptase polymerase chain reaction for the detection of circulating prostate cells

The reverse transcriptase polymerase chain reaction (RT-PCR) is a sensitive technique that can detect prostate-specific messenger RNA in circulating blood. Many authors have studied the potential of RT-PCR as a staging technique in prostate cancer (PC). Clinical sensitivity and in some cases specificity has been disappointing. Few authors have been able to correlate RT-PCR result with patient stage. We have compared the results of using two different RT-PCR protocols with different sensitivities on blood samples from prostate cancer patients. An 80-amplification-cycle nested primer RT-PCR assay had a detection limit of 10 prostate cells and a 50-cycle RT-PCR could detect 20 cells in 5 ml blood. The 80-cycle assay detected prostate mRNA in four of 10 female samples, whereas the 50-cycle assay detected it in none. There was little difference in the assays’ ability to detect prostate mRNA in advanced PC patients. The 50-cycle assay could differentiate between hormone-escaped, stable hormone-treated and untreated localized PC patients, whereas the 80-cycle assay could not. Each blood sample must be assayed several times with RT-PCR to avoid false-negative results and, if this is done, assay specificity can be increased with little effect on clinical sensitivity. © 2000 Cancer Research Campaig