The effect of response order on candidate viewing behaviour and item difficulty in a multiple-choice listening test

Studies from various disciplines have reported that spatial location of options in relation to processing order impacts the ultimate choice of the option. A large number of studies have found a primacy effect, that is, the tendency to prefer the first option. In this paper we report on evidence that position of the key in four-option multiple-choice (MC) listening test items may affect item difficulty and thereby potentially introduce construct-irrelevant variance.Two sets of analyses were undertaken. With Study 1 we explored 30 test takers’ processing via eye-tracking on listening items from the Aptis Test. An unexpected finding concerned the amount of processing undertaken on different response options on the MC questions, given their order. Based on this, in Study 2 we looked at the direct effect of key position on item difficulty in a sample of 200 live Aptis items and around 6000 test takers per item.The results suggest that the spatial location of the key in MC listening tests affects the amount of processing it receives and the item’s difficulty. Given the widespread use of MC tasks in language assessments, these findings seem crucial, particularly for tests that randomize response order. Candidates who by chance have many keys in last position might be significantly disadvantaged

Two small, cysteine-rich and cationic antifungal proteins from Penicillium chrysogenum: A comparative study of PAF and PAFB

The filamentous fungus Penicillium chrysogenum Q176 secretes the antimicrobial proteins (AMPs) PAF and PAFB, which share a compact disulfide-bond mediated, β-fold structure rendering them highly stable. These two AMPs effectively inhibit the growth of human pathogenic fungi in micromolar concentrations and exhibit antiviral potential without causing cytotoxic effects on mammalian cells in vitro and in vivo. The antifungal mechanism of action of both AMPs is closely linked to - but not solely dependent on - the lipid composition of the fungal cell membrane and requires a strictly regulated protein uptake into the cell, indicating that PAF and PAFB are not canonical membrane active proteins. Variations in their antifungal spectrum and their killing dynamics point towards a divergent mode of action related to their physicochemical properties and surface charge distribution. In this review, we relate characteristic features of PAF and PAFB to the current knowledge about other AMPs of different sources. In addition, we present original data that have never been published before to substantiate our assumptions and provide evidences that help to explain and understand better the mechanistic function of PAF and PAFB. Finally, we underline the promising potential of PAF and PAFB as future antifungal therapeutics

Nonlinear Dynamics of Composite Fermions in Nanostructures

We outline a theory describing the quasi-classical dynamics of composite fermions in the fractional quantum Hall regime in the potentials of arbitrary nanostructures. By an appropriate parametrization of time we show that their trajectories are independent of their mass and dispersion. This allows to study the dynamics in terms of an effective Hamiltonian although the actual dispersion is as yet unknown. The applicability of the theory is verified in the case of antidot arrays where it explains details of magnetoresistance measurements and thus confirms the existence of these quasiparticles.Comment: submitted to Europhys. Lett., 4 pages, postscrip

Effects of periodic breathing on sleep at high altitude: a randomized, placebo-controlled, crossover study using inspiratory CO2

Abstract: Hypoxia at high altitude facilitates changes in ventilatory control that can lead to nocturnal periodic breathing (nPB). Here, we introduce a placebo-controlled approach to prevent nPB by increasing inspiratory CO2 and used it to assess whether nPB contributes to the adverse effects of hypoxia on sleep architecture. In a randomized, single-blinded, crossover design, 12 men underwent two sojourns (three days/nights each, separated by 4 weeks) in hypobaric hypoxia corresponding to 4000 m altitude, with polysomnography during the first and third night of each sojourn. During all nights, subjects’ heads were encompassed by a canopy retaining exhaled CO2, and CO2 concentration in the canopy (i.e. inspiratory CO2 concentration) was controlled by adjustment of fresh air inflow. Throughout the placebo sojourn inspiratory CO2 was ≤0.2%, whereas throughout the other sojourn it was increased to 1.76% (IQR, 1.07%–2.44%). During the placebo sojourn, total sleep time (TST) with nPB was 54.3% (37.4%–80.8%) and 45.0% (24.5%–56.5%) during the first and the third night, respectively (P = 0.042). Increased inspiratory CO2 reduced TST with nPB by an absolute 38.1% (28.1%–48.1%), the apnoea–hypopnoea index by 58.1/h (40.1–76.1/h), and oxygen desaturation index ≥3% by 56.0/h (38.9.1–73.2/h) (all P < 0.001), whereas it increased the mean arterial oxygen saturation in TST by 2.0% (0.4%–3.5%, P = 0.035). Increased inspiratory CO2 slightly increased the percentage of N3 sleep during the third night (P = 0.045), without other effects on sleep architecture. Increasing inspiratory CO2 effectively prevented hypoxia-induced nPB without affecting sleep macro-architecture, indicating that nPB does not explain the sleep deterioration commonly observed at high altitudes. (Figure presented.). Key points: Periodic breathing is common during sleep at high altitude, and it is unclear how this affects sleep architecture. We developed a placebo-controlled approach to prevent nocturnal periodic breathing (nPB) with inspiratory CO2 administration and used it to assess the effects of nPB on sleep in hypobaric hypoxia. Nocturnal periodic breathing was effectively mitigated by an increased inspiratory CO2 fraction in a blinded manner. Prevention of nPB did not lead to relevant changes in sleep architecture in hypobaric hypoxia. We conclude that nPB does not explain the deterioration in sleep architecture commonly observed at high altitude

Forests for the New Millennium - MAKING FORESTS WORK FOR PEOPLE AND NATURE

THE WAYS IN WHICH FORESTS ARE PERCEIVED AND USED HAVE CHANGED DRAMATICALLY OVER RECENT YEARS. FORESTS ARE NO LONGER SEEN SIMPLY AS A SOURCE OF TIMBER, BUT AS COMPLEX ECOSYSTEMS WHICH SUSTAIN LIVELIHOODS AND PROVIDE A RANGE OF PRODUCTS AND ENVIRONMENTAL SERVICES. IT IS NOW WIDELY RECOGNISED THAT FORESTS CAN CONTRIBUTE TO RURAL DEVELOPMENT AND POVERTY ALLEVIATION.Forest, economics, livelihoods

9th Annual Seminar on Legal Issues for Financial Institutions

Outline of speakers\u27 presentations from the 9th Annual Seminar on Legal Issues for Financial Institutions held by UK/CLE on March 10-11, 1989

MRCP compared to diagnostic ERCP for diagnosis when biliary obstruction is suspected: a systematic review

BACKGROUND: Magnetic resonance cholangiopancreatography (MRCP) is an alternative to diagnostic endoscopic retrograde cholangiopancreatography (ERCP) for investigating biliary obstruction. The use of MRCP, a non-invasive procedure, may prevent the use of unnecessary invasive procedures. The aim of the study was to compare the findings of MRCP with those of ERCP by the computation of accuracy statistics. METHODS: Thirteen electronic bibliographic databases, covering biomedical, science, health economics and grey literature were searched. A systematic review of studies comparing MRCP to diagnostic ERCP in patients with suspected biliary obstruction was conducted. Sensitivity, specificity, likelihood ratios, acceptability and adverse events were reported. RESULTS: 25 studies were identified reporting several conditions including choledocholithiasis (18 studies), malignancy (four studies), obstruction (three studies), stricture (two studies) and dilatation (five studies). Three of the 18 studies reporting choledocholithiasis were excluded from the analysis due to lack of data, or differences in study design. The sensitivity for the 15 studies of choledocholithiasis ranged from 0.50 to 1.00 while specificity ranged from 0.83 to 1.00. The positive likelihood ratio ranged: from 5.44–47.72 and the negative likelihood ratio for the 15 studies ranged from 0.00–0.51. Significant heterogeneity was found across the 15 studies so the sensitivities and specificities were summarised by a Receiver Operating Characteristic (ROC) curve. For malignancy, sensitivity ranged from 0.81 to 0.94 and specificity from 0.92 to 1.00. Positive likelihood ratios ranged from 10.12 to 43 and negative likelihood ratios ranged from 0.15 to 0.21, although these estimates were less reliable. CONCLUSION: MRCP is a comparable diagnostic investigation in comparison to ERCP for diagnosing biliary obstruction

Frequency and Nature of Incidental Extra-Enteric Lesions Found on Magnetic Resonance Enterography (MR-E) in Patients with Inflammatory Bowel Diseases (IBD)

The aim of this study was to determine the occurrence of extra-enteric findings in a large cohort of patients undergoing magnetic resonance enterography (MR-E) and to classify the clinical significance of these findings.We retrospectively analyzed 1154 MR-E performed in 1006 patients referred to our radiological department between 1999-2005. The reasons for referral were suspected or proven inflammatory bowel diseases (IBD) (n = 710), further diagnostic work-up for small bowel disease because of non-specific abdominal symptoms (SBD; n = 182) or suspected small bowel malignancies (SBM; n = 114). All extra-enteric findings were reviewed by a radiologist and a gastroenterologist and were classified as having high, moderate, or low significance for further diagnostic or therapeutic procedures.The average age of all patients was 40+/-16 (Mean+/-SD) years (y) (IBD 35+/-13 y; SBD 49+/-16 y; SBM 57+/-15 y). A total of 1113 extra-enteric findings were detected in 600 of 1006 patients (59.6%). Of these findings 180 (16.2%) were judged as having a high, 212 (19.0%) a moderate and 721 (64.8%) a low significance. On a per group basis in patients with IBD 12.0% of the findings were of major clinical significance compared to 13.7% and 33.3% in patients with SBD and SBM, respectively. The most common major findings were abscesses (69.9%) in the IBD group and extraintestinal tumors, metastases or masses in the SBD and SBM groups (41.9% and 74.2%, respectively).MR-E reveals a substantial number of extra-enteric findings, supporting the role of a cross-sectional imaging method for the evaluation of the small bowel

Des Forêts pour le Nouveau Millénaire - DES FORÊTS À GÉRER DANS L’INTÉRÊT DES GENS ET DE LA NATURE

LA FAÇON DONT LES FORÊTS SONT PERÇUES ET LEURS UTILISATIONS ONT BEAUCOUP CHANGÉ AU COURS DES DERNIÈRES ANNÉES. LES FORÊTS NE SONT PLUS CONSIDÉRÉES COMME ÉTANT UNIQUEMENT DES SOURCES DE BOIS MAIS DES ÉCOSYSTÈMES COMPLEXES QUI PERMETTENT À DES COMMUNAUTÉS DE SE DÉVELOPPER ET OFFRENT TOUTE UNE GAMME DE PRODUITS ET DE SERVICES ENVIRONNEMENTAUX. ON RECONNAÎT AUJOURD’HUI QUE LES FORÊTS PEUVENT CONTRIBUER AU DÉVELOPPEMENT RURAL ET À LA LUTTE CONTRE LA PAUVRETÉ.Forêt, économie