Editors' Review and Introduction: Learning Grammatical Structures: Developmental, Cross‐Species, and Computational Approaches

Human languages all have a grammar, that is, rules that determine how symbols in a language can be combined to create complex meaningful expressions. Despite decades of research, the evolutionary, developmental, cognitive, and computational bases of grammatical abilities are still not fully understood. “Artificial Grammar Learning” (AGL) studies provide important insights into how rules and structured sequences are learned, the relevance of these processes to language in humans, and whether the cognitive systems involved are shared with other animals. AGL tasks can be used to study how human adults, infants, animals, or machines learn artificial grammars of various sorts, consisting of rules defined typically over syllables, sounds, or visual items. In this introduction, we distill some lessons from the nine other papers in this special issue, which review the advances made from this growing body of literature. We provide a critical synthesis, identify the questions that remain open, and recognize the challenges that lie ahead. A key observation across the disciplines is that the limits of human, animal, and machine capabilities have yet to be found. Thus, this interdisciplinary area of research firmly rooted in the cognitive sciences has unearthed exciting new questions and venues for research, along the way fostering impactful collaborations between traditionally disconnected disciplines that are breaking scientific ground

Medical students’ views about having different types of problem-based learning tutors

Background At Norwich Medical School, Year 3 or 4 medical students taking a year out of the 5-year undergraduate MBBS degree to do a master’s degree in clinical education worked as near-peer problem-based learning (PBL) tutors for students in Year 2. Peer-assisted learning has been shown to benefit both peer tutors and tutees; in this study, experiences of students with near-peer PBL tutors were compared to students with other types of PBL tutor. Methods Using existing student evaluation data, we compared student views about PBL tutor performance, PBL group functioning, and overall satisfaction with PBL learning experience according to whether their PBL tutor/s were (1) a single near-peer tutor (later-year MB BS student), (2) a single staff tutor, (3) multiple staff tutors, or (4) multiple newly qualified doctor tutors. Results Results indicated that students’ evaluation of tutor performance was more positive for near-peer PBL tutors compared to both groups of staff tutors for most areas evaluated. Additionally, students’ evaluation of overall satisfaction with PBL was more positive for near-peer PBL tutors compared to multiple staff tutors. Tutor performance for multiple staff tutors was evaluated less positively compared to both single staff and multiple newly qualified doctor groups. But there were no statistically significant differences between the four groups regarding PBL group functioning. Conclusion Near-peer PBL tutors perform comparably or better to staff PBL tutors in salient measures of tutor performance and group functioning. We conclude that medical students find near-peer PBL tutors to be an acceptable addition to the PBL tutor workforce

Release of Soluble Receptors for Tumor Necrosis Factor in Clinical Sepsis and Experimental Endotoxemia

To assess the role of tumor necrosis factor (TNF) in the appearance of soluble TNF receptors (sTNFRs), 20 consecutive patients with a clinical diagnosis of sepsis were studied as were 7 chimpanzees after administration of endotoxin (4 ng/kg) with or without pentoxifylline. The patients had markedly elevated serum levels of sTNFR-p55 and sTNFR-p75 compared with healthy controls (P < .0001 for both receptors). The levels of both soluble receptors correlated with simultaneously measured immunoreactive TNF concentrations (p55: r = .63, P < .01; p75: r = .69, P < .001). In the chimpanzees, endotoxin induced subsequent rises in the serum concentrations ofTNF and sTNFRs. Although pentoxifylline reduced the TNF response to intravenous endotoxin to 20% (P < .05), the appearance of sTNFRs was only moderately inhibited (sTNFR-p55 to 79% on average, P < .05; sTNFR-p75 to 77%, P = .12). These results indicate that TNF either does not play an important role in the appearance of sTNFRs in systemic infection or that a small amount ofTNF remaining in the circulation after some bacterial challenges is sufficient to preserve the secretion of its soluble receptor

ОБМЕН СООБЩЕНИЯМИ В МИКС-СЕТЯХ

Рассмотрена идея Д.Чаума организации анонимной микс-сети с пересылкой сообщений через каскад миксов (передаточных узлов) и последовательным шифрованием всех промежуточных результатов. Описаны задачи, решаемые миксами в ходе обеспечения анонимности связи, обговариваются проблемы ее безопасности

Laboratory testing in patients treated with direct oral anticoagulants: a practical guide for clinicians

Click to hear Dr Baglin's perspective on the role of the laboratory in treatment with new oral anticoagulants SUMMARY: One of the key benefits of the direct oral anticoagulants (DOACs) is that they do not require routine laboratory monitoring. Nevertheless, assessment of DOAC exposure and anticoagulant effects may become useful in various clinical scenarios. The five approved DOACs (apixaban, betrixaban, dabigatran etexilate, edoxaban and rivaroxaban) have different characteristics impacting assay selection and the interpretation of results. This article provides an updated overview on (i) which test to use (and their advantages and limitations), (ii) when to assay DOAC levels, (iii) how to interpret the results relating to bleeding risk, emergency situations and perioperative management, and (iv) what is the impact of DOACs on routine and specialized coagulation assays. Assays for anti-Xa or anti-IIa activity are the preferred methods when quantitative information is useful, although the situations in which to test for DOAC levels are still debated. Different reagent sensitivities and variabilities in laboratory calibrations impact assay results. International calibration standards for all specific tests for each DOAC are needed to reduce the inter-laboratory variability and allow inter-study comparisons. The impact of the DOACs on hemostasis testing may cause false-positive or false-negative results; however, these can be minimized by using specific assays and collecting blood samples at trough concentrations. Finally, prospective clinical trials are needed to validate the safety and efficacy of proposed laboratory thresholds in relation to clinical decisions. We offer recommendations on the tests to use for measuring DOACs and practical guidance on laboratory testing to help patient management and avoid diagnostic errors. ispartof: Journal of Thrombosis and Haemostasis vol:16 issue:2 pages:209-219 ispartof: location:England status: publishe

Modulation of Contact System Proteases by Glycosaminoglycans SELECTIVE ENHANCEMENT OF THE INHIBITION OF FACTOR XIa

Abstract We investigated the influence of dextran sulfate, heparin, heparan sulfate, and dermatan sulfate on the inhibition of FXIa (where FXIa is activated factor XI, for example), FXIIa, and kallikrein by C1 inhibitor, α1-antitrypsin, α2-antiplasmin, and antithrombin III. The second-order rate constants for the inhibition of FXIa by C1 inhibitor, α1-antitrypsin, α2-antiplasmin, and antithrombin III, in the absence of glycosaminoglycans, were 1.8, 0.1, 0.43, and 0.32 × 103 M−1 s−1, respectively. The rate constants of the inactivation of FXIa by C1 inhibitor and by antithrombin III increased up to 117-fold in the presence of glycosaminoglycans. These data predicted that considering the plasma concentration of the inhibitors, C1 inhibitor would be the main inhibitor of FXIa in plasma in the presence of glycosaminoglycans. Results of experiments in which the formation of complexes between serine protease inhibitors and FXIa was studied in plasma agreed with this prediction. Glycosaminoglycans did not enhance the inhibition of α-FXIIa, β-FXIIa, or kallikrein by C1 inhibitor. Thus, physiological glycosaminoglycans selectively enhance inhibition of FXIa without affecting the activity of FXIIa and kallikrein, suggesting that glycosaminoglycans may modulate the biological effects of contact activation, by inhibiting intrinsic coagulation without affecting the fibrinolytic potential of FXIIa/kallikrein

Remote Non-invasive Stereoscopic Imaging of Blood Vessels: First In-vivo Results of a New Multispectral Contrast Enhancement Technology

We describe a contactless optical technique selectively enhancing superficial blood vessels below variously pigmented intact human skin by combining images in different spectral bands. Two CMOS-cameras, with apochromatic lenses and dual-band LED-arrays, simultaneously streamed Left (L) and Right (R) image data to a dual-processor PC. Both cameras captured color images within the visible range (VIS, 400–780 nm) and grey-scale images within the near infrared range (NIR, 910–920 nm) by sequentially switching between LED-array emission bands. Image-size-settings of 1280 × 1024 for VIS & 640 × 512 for NIR produced 12 cycles/s (1 cycle = 1 VIS L&R-pair + 1 NIR L&R-pair). Decreasing image-size-settings (640 × 512 for VIS and 320 × 256 for NIR) increased camera-speed to 25 cycles/s. Contrasts from below the tissue surface were algorithmically distinguished from surface shadows, reflections, etc. Thus blood vessels were selectively enhanced and back-projected into the stereoscopic VIS-color-image using either a 3D-display or conventional shutter glasses. As a first usability reconnaissance we applied this custom-built mobile stereoscopic camera for several clinical settings: • blood withdrawal; • vein inspection in dark skin; • vein detection through iodide; • varicose vein and nevi pigmentosum inspection. Our technique improves blood vessel visualization compared to the naked eye, and supports depth perception