243 research outputs found
The rhythm of life: the perfect rhythm of morse code
Morse code is a unique exemplar of the inherent complexities of rhythm. Learning Morse code in wartime presented challenges to expedite skill acquisition. This thesis explored the strategies used to teach and learn Morse code in the second World War and investigated the resourceful techniques used by the WRANS in an empirical study. The first study investigated the teaching and learning strategies of wartime telegraphists to learn Morse code. Five WRANS described a series of techniques to learn Morse code, including rote learning and repetition, visualisation and pattern recognition, intoning and mnemonics, and music. Music provided effective training for the fundamental teaching and learning of Morse code by matching the rhythmical properties of Morse code to music. Music equipped Morse code operators with a unique approach to Morse code instruction. Learning Morse code with music was described as a way of making sense of the ‘rhythm’ and ‘shape’ of the Morse code letters and proved an invaluable aid to learning and teaching Morse code. The second study examined the effectiveness of learning Morse code with the aid of music. Novices formed two groups, Control Group (no music aid) and Music Group (with music aid). Results confirmed the effectiveness of music training in three Morse code letters, Q V, and A in two experiments, the first with known Morse code letters (Q V A) and the second with unknown letters. The Music Group accurately identified 90% of known and unknown Morse code letters compared to the Control Group who identified less then 50% of known and unknown Morse code letters. This thesis explored the transferable attributes of rhythm perception in music as a teaching and learning mechanism for Morse code. There is extensive research on the complex learning and retention of Morse code but the studies in this thesis have indicated that the ground-breaking wartime strategy of music and Morse code is a powerful duo. The investigation of learning and teaching strategies of the WRANS showed that musical rhythm influenced the skill acquisition of Morse code and the perceptual test suggests that current work in rhythm perception extends beyond music pedagogy and has further implications for all cognitive function
Green beach vegetation dynamics explained by embryo dune development
Sandy coastlines are dynamic environments with potential for biodiverse habitats, such as green beaches. Green beach vegetation can develop on nutrient-poor beaches landward from embryo dunes. It is characterised by low-dynamic coastal wetland habitat such as salt marshes and dune slacks. It has been hypothesised that the establishment of green beach vegetation is facilitated by the shelter provided by embryo dunes, however evidence is lacking. We explored the importance of geomorphology and soil conditions on the species richness and turnover of green beach vegetation over a time period of 10 years. We recorded 107 plots along 11 transects over a gradient from beach to dune on the island of Schiermonnikoog, the Netherlands. We characterised transect geomorphology at transect level and soil conditions and vegetation at plot level in 2006 and 2016. We found that the green beach vegetation was highly dynamic, total plant cover increased by 62% within 10 years. In 2006 beach width was an important factor in explaining species richness, with the highest number of species occurring on narrow beaches with a large volume of embryo dunes. In 2016, species richness was positively associated with the build-up of organic matter. Overall species richness declined relative to 2006 and was accompanied by an increase in elevation due to sand burial and the expansion of embryo dune volume. Our data suggests that geomorphology influenced the vegetation indirectly by affecting sand burial rate. Plant species richness declined less at sheltered conditions where sand burial was limited, allowing the build-up of organic matter. This indicates a time-dependent relationship between the development of embryo dunes and plant species richness: embryo dunes can be a source of shelter, thus increasing species richness, but can compete for space over time, lowering species richness again. Our results are relevant for engineering and management of biodiverse sandy shores
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Recalibrating and Combining Ensemble Predictions
The “model output statistics” (MOS) approach has long been used in forecasting to correct systematic errors of numerical models and to predict quantities not included in the model (Glahn and Lowry 1972). The MOS procedure is based on capturing the statistical relation between model outputs and observations and, in its simplest form, consists of a linear regression between these quantities. In theory, this procedure optimally calibrates the model forecast and provides reliable forecasts.
In practice, the regression parameters must be estimated from data. In seasonal forecasting, forecast histories are short, and skill is modest. Both factors lead to substantial sampling errors in the estimates. This work examines two problems where sampling error affects the reliability of regression-calibrated forecasts and provides solutions based on two “penalized” methods: ridge regression and lasso regression (Hoerl and Kennard 1988; Tibshirani 1996). The first problem comes from the observation that, even in a bivariate setting, ordinary least squares estimates lead to unreliable forecasts. The second problem arises in the context of multivariate MOS and is that common methods of predictor selection lead to negative skill and unreliable forecasts
Regulacija puta razgradnje pentoza s pomoću gena izoliranih iz plijesni Aspergillus niger
The aim of this study was to obtain a better understanding of the pentose catabolism in Aspergillus niger and the regulatory systems that affect it. To this end, we have cloned and characterised the genes encoding A. niger L-arabitol dehydrogenase (ladA) and xylitol dehydrogenase (xdhA), and compared the regulation of these genes to other genes of the pentose catabolic pathway. This demonstrated that activation of the pathway depends on two transcriptional regulators, the xylanolytic activator (XlnR) and an unidentified L-arabinose specific regulator (AraR). These two regulators affect those genes of the pentose catabolic pathway that are related to catabolic conversion of their corresponding inducers (D-xylose and L-arabinose, respectively).Istraživanje je provedeno radi boljeg razumijevanja puta razgradnje pentoza plijesni Aspergillus niger i regulacijskih sustava koji na njega utječu. Klonirani su i karakterizirani geni koji kodiraju L-arabitol dehidrogenazu (ladA) i ksilitol dehidrogenazu (xdhA) plijesni A. niger, te uspoređeni s ostalim genima koji reguliraju put razgradnje pentoza. Otkriveno je da aktivacija puta razgradnje ovisi o dva regulatora transkripcije gena, tj. aktivatoru razgradnje D-ksiloze (XlnR) i regulatoru ekspresije gena pri razgradnji L-arabinoze (AraR)
Influenza vaccination of healthcare workers in acute-care hospitals: a case-control study of its effect on hospital-acquired influenza among patients
<p>Abstract</p> <p>Background</p> <p>In acute-care hospitals, no evidence of a protective effect of healthcare worker (HCW) vaccination on hospital-acquired influenza (HAI) in patients has been documented. Our study objective was to ascertain the effectiveness of influenza vaccination of HCW on HAI among patients.</p> <p>Methods</p> <p>A nested case-control investigation was implemented in a prospective surveillance study of influenza-like illness (ILI) in a tertiary acute-care university hospital. Cases were patients with virologically-confirmed influenza occurring ≥ 72 h after admission, and controls were patients with ILI presenting during hospitalisation with negative influenza results after nasal swab testing. Four controls per case, matched per influenza season (2004-05, 2005-06 and 2006-07), were randomly selected. Univariate and multivariate conditional logistic regression models were fitted to assess factors associated with HAI among patients.</p> <p>Results</p> <p>In total, among 55 patients analysed, 11 (20%) had laboratory-confirmed HAI. The median HCW vaccination rate in the units was 36%. The median proportion of vaccinated HCW in these units was 11.5% for cases vs. 36.1% for the controls (<it>P </it>= 0.11); 2 (20%) cases and 21 (48%) controls were vaccinated against influenza in the current season (<it>P </it>= 0.16). The proportion of ≥ 35% vaccinated HCW in short-stay units appeared to protect against HAI among patients (odds ratio = 0.07; 95% confidence interval 0.005-0.98), independently of patient age, influenza season and potential influenza source in the units.</p> <p>Conclusions</p> <p>Our observational study indicates a shielding effect of more than 35% of vaccinated HCW on HAI among patients in acute-care units. Investigations, such as controlled clinical trials, are needed to validate the benefits of HCW vaccination on HAI incidence in patients.</p
Gaia on-board metrology: basic angle and best focus
The Gaia payload ensures maximum passive stability using a single material,
SiC, for most of its elements. Dedicated metrology instruments are, however,
required to carry out two functions: monitoring the basic angle and refocusing
the telescope. Two interferometers fed by the same laser are used to measure
the basic angle changes at the level of as (prad, micropixel), which is
the highest level ever achieved in space. Two Shack-Hartmann wavefront sensors,
combined with an ad-hoc analysis of the scientific data are used to define and
reach the overall best-focus. In this contribution, the systems, data analysis,
procedures and performance achieved during commissioning are presentedComment: 18 pages, 14 figures. To appear in SPIE proceedings 9143-30. Space
Telescopes and Instrumentation 2014: Optical, Infrared, and Millimeter Wav
Regulacija puta razgradnje pentoza s pomoću gena izoliranih iz plijesni Aspergillus niger
The aim of this study was to obtain a better understanding of the pentose catabolism in Aspergillus niger and the regulatory systems that affect it. To this end, we have cloned and characterised the genes encoding A. niger L-arabitol dehydrogenase (ladA) and xylitol dehydrogenase (xdhA), and compared the regulation of these genes to other genes of the pentose catabolic pathway. This demonstrated that activation of the pathway depends on two transcriptional regulators, the xylanolytic activator (XlnR) and an unidentified L-arabinose specific regulator (AraR). These two regulators affect those genes of the pentose catabolic pathway that are related to catabolic conversion of their corresponding inducers (D-xylose and L-arabinose, respectively).Istraživanje je provedeno radi boljeg razumijevanja puta razgradnje pentoza plijesni Aspergillus niger i regulacijskih sustava koji na njega utječu. Klonirani su i karakterizirani geni koji kodiraju L-arabitol dehidrogenazu (ladA) i ksilitol dehidrogenazu (xdhA) plijesni A. niger, te uspoređeni s ostalim genima koji reguliraju put razgradnje pentoza. Otkriveno je da aktivacija puta razgradnje ovisi o dva regulatora transkripcije gena, tj. aktivatoru razgradnje D-ksiloze (XlnR) i regulatoru ekspresije gena pri razgradnji L-arabinoze (AraR)
Patients Enrolled in Large Randomized Clinical Trials of Antiplatelet Treatment for Prevention After Transient Ischemic Attack or Ischemic Stroke Are Not Representative of Patients in Clinical Practice: the Netherlands Stroke Survey
Background and Purpose—Many randomized clinical trials have evaluated the benefit of long-term use of antiplatelet
drugs in reducing the risk of new vascular events in patients with a recent transient ischemic attack or ischemic stroke.
Evidence from these trials forms the basis for national and international guidelines for the management of nearly all such
patients in clinical practice. However, abundant and strict enrollment criteria may limit the validity and the applicability
of results of randomized clinical trials to clinical practice. We estimated the eligibility for participation in landmark trials
of antiplatelet drugs of an unselected group of patients with stroke or transient ischemic attack from a national stroke
survey.
Methods—Nine hundred seventy-two patients with transient ischemic at
What is the 'problem' that outreach work seeks to address and how might it be tackled? Seeking theory in a primary health prevention programme
<b>Background</b> Preventive approaches to health are disproportionately accessed by the more affluent and recent health improvement policy advocates the use of targeted preventive primary care to reduce risk factors in poorer individuals and communities. Outreach has become part of the health service response. Outreach has a long history of engaging those who do not otherwise access services. It has, however, been described as eclectic in its purpose, clientele and mode of practice; its effectiveness is unproven. Using a primary prevention programme in the UK as a case, this paper addresses two research questions: what are the perceived problems of non-engagement that outreach aims to address; and, what specific mechanisms of outreach are hypothesised to tackle these.<p></p>
<b>Methods</b> Drawing on a wider programme evaluation, the study undertook qualitative interviews with strategically selected health-care professionals. The analysis was thematically guided by the concept of 'candidacy' which theorises the dynamic process through which services and individuals negotiate appropriate service use.<p></p>
<b>Results</b> The study identified seven types of engagement 'problem' and corresponding solutions. These 'problems' lie on a continuum of complexity in terms of the challenges they present to primary care. Reasons for non-engagement are congruent with the concept of 'candidacy' but point to ways in which it can be expanded.<p></p>
<b>Conclusions</b> The paper draws conclusions about the role of outreach in contributing to the implementation of inequalities focused primary prevention and identifies further research needed in the theoretical development of both outreach as an approach and candidacy as a conceptual framework
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