Learning with invisible others: Perceptions of online presence and their relationship to cognitive and affective learning

This is the publisher's version, also available electronically from http://www.ifets.info/others/abstract.php?art_id=521is study investigated the relationship between student perceptions of others in an online class and both affective and cognitive learning outcomes. Data were gathered from student survey responses and instructor evaluation of performance. Results from this study indicated significant correlations between student perceptions of the presence of other students in the class and scores on an attitudes scale and their satisfaction with their own learning. This finding demonstrates the salience of other students in the learning environment to affective learning outcomes. Perceptions of the instructor’s presence were significantly correlated with both affective learning and with student learning satisfaction. This outcome in an online class is consistent with findings on teacher immediacy literature in traditional classes and highlight the role of the teacher in establishing a learning environment. Results relative to cognitive learning showed that student reports of their perception of their own presence in the class were significantly correlated with performance in the class and with the grade they would assign themselves

Rapid assembly of highly-functionalised difluorinated cyclooctenones via ring-closing metathesis

Building block methodology from trifluoroethanol and ringclosing metathesis using a Fürstner modification of Grubbs’ conditions allows the rapid synthesis of novel difluorinated cyclooctenones

Counterfeit Alcohol Distribution:A Criminological Script Network Analysis

This paper analyses a series of subsequent and connected investigations by a domestic European regulator on the network of distribution of counterfeit alcohol across two jurisdictions. The analysis mixes script analysis, a narrative framework for enhancing the understanding of how crimes unfold and are organized, with multi-node multi-link social network analysis, to observe the social structure in which crime scripts take place. We focus our attention on the key players that occupy strategic positions within the network of the crime commission process, from where they overview and control the various phases (scenes) and perform brokerage activities across the scenes, and on strategies of concealment of illicit products beyond the facade of legitimate business. Our findings indicate that actors in charge of managing the proceeds of the criminal activity are also the ones better positioned to monitor the entire process. The overall structure of the criminal network shows a good level of resilience and efficiency, although actors do not adopt common traits of a criminal lifestyle that facilitate secrecy and covertness. We believe that, by shifting the analysis from the nature of the group organization to the network of links between all the aspects of a crime commission process, the organizational structure and its weakest links become more detectable, easier to compare across proto- and meta-scripts, and ultimately more prone to situational preventive measures

No difference in surgical outcomes between Open and Closed exposure of palatally displaced maxillary canines

Purpose: To investigate differences in the surgical outcomes between Open and Closed exposure for palatally displaced maxillary cuspids (PDC). Methods: A multicenter, RCT involving two parallel groups. The settings were one dental teaching hospital in, and two hospital units near Sheffield, UK. Participants were aged <20 years with a unilateral PDC, who provided informed consent. They were randomly allocated to either receive the Open (O) or the Closed (C) surgical procedure. The outcomes were time spent in the operating room and 10-day post-operative patient questionnaire. Statistical differences between the two techniques were tested using independent t tests for continuous variables and chi-squared tests for frequencies. Results: The final study sample was composed of 71 participants (64% females). There were no differences in the gender ratios (O: F=27, M=13; C: F=25, M=16) or mean ages of the two groups (O: 14.3 yrs SD 1.3; C: 14.1 yrs SD 1.6) at the start. The mean operating times for the Open and Closed techniques were 34.3 mins (SD 11.2) and 34.3 mins (SD 11.9) respectively (p=.986). There were no statistically significant differences between the two treatment groups for any of the patient-assessed outcomes (p>.05). Conclusions: There were no differences in the surgical outcomes investigated in this study between Open and Closed exposure for PDC

Change in the size of Walker Lake during the past 5000 years

In 1984, a 12-m sediment core (WLC84-8) was taken from the deepest part of Walker Lake. Samples of the core were analysed for diatoms, pollen, carbonate mineralogy, magnesium content, [delta]18O and [delta]13C values of the total inorganic fractin, [delta]18O and [delta]13C values of Limnocythere ceriotuberosa, [delta]13C values of the total organic fraction, grain size, and magnetic susceptibility. The data indicate that Walker Lake became shallow and probably desiccated between [ges]5300-4800 and 2700-2100 yr B.P.. Each of the organic and inorganic proxy indicators of lake size discussed in this paper was useful in determining the presence of the shallow-lake intervals. However, none of the indicators was useful in determining the cause of the shallow-lake intervals. Instead, the types of fish living in Walker Lake prior to 1940 were used to demonstrate that shallow-lake intervals resulted from diversion of the Walker River and not from climatic aridity. Major changes in mineralogy and magnesium content of carbonates and major changes in diatom populations with time were found to be a function of the chemical evolution of Walker Lake combined with changing lake size. The stable isotopes of oxygen and carbon were found to be good indicators of lake volume changes. A lake-level record for Walker Lake constructed from stable-isotope data was found to be similar to a lake-level record constructed using tufa and tree-stump data. Both records indicate relatively high lake levels between 4800-2700 yr B.P., at 1250 yr B.P., and within the last 300 yr. Substantial declines in lake level occurred ~2000 and ~1000 yr B.P.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29575/1/0000663.pd

Correcting the extended-source calibration for the <i>Herschel</i>-SPIRE Fourier-transform spectrometer

We describe an update to the Herschel-Spectral and Photometric Imaging Receiver (SPIRE) Fourier-transform spectrometer (FTS) calibration for extended sources, which incorporates a correction for the frequency-dependent far-field feedhorn efficiency, ηff. This significant correction affects all FTS extended-source calibrated spectra in sparse or mapping mode, regardless of the spectral resolution. Line fluxes and continuum levels are underestimated by factors of 1.3–2 in thespectrometer long wavelength band (447–1018 GHz; 671–294 μm) and 1.4–1.5 in the spectrometer short wavelength band (944–1568 GHz; 318–191 μm). The correction was implemented in the FTS pipeline version 14.1 and has also been described in the SPIRE Handbook since 2017 February. Studies based on extended-source calibrated spectra produced prior to this pipeline version should be critically reconsidered using the current products available in the Herschel Science Archive. Once the extended-source calibrated spectra are corrected for ηff, the synthetic photometry and the broad-band intensities from SPIRE photometer maps agree within 2–4 per cent – similar levels to the comparison of point-source calibrated spectra and photometry from point-source calibrated maps. The two calibration schemes for the FTS are now self-consistent: the conversion between the corrected extended-source and point-source calibrated spectra can be achieved with the beam solid angle and a gain correction that accounts for the diffraction loss