Forthcoming Publications - A

This research introduces a unique multiple choice exam design to observe and measure the degree to which students copy answers from their peers. Using data collected from the exam, an empirical experiment is conducted to determine whether random seat assignment deters cheating relative to a control group of students allowed to choose their seats. Empirical results demonstrate a significant decline in measured cheating within the assigned seating sample. This study contributes to the literature by providing a measurement of actual cheating frequency among students, as opposed to relying on reported cheating in anonymous surveys, and by demonstrating that an easily implemented deterrent can significantly reduce instances of cheating

Zastosowanie polskiej adaptacji Montrealskiego Testu do Oceny Funkcji Poznawczych (MoCA) w przesiewowej ocenie funkcji poznawczych

Background and purpose The Montreal Cognitive Assessment (MoCA) test is a brief cognitive screening tool with high sensitivity and specificity for detecting mild cognitive impairment (MCI). The aim of this study was to evaluate the usefulness of MoCA and compare it with the Mini-Mental State Examination (MMSE) in the early detection of cognitive decline in MCI. Material and methods A group of 115 subjects (36 meeting DSM-IV criteria for Alzheimer disease (AD) [Clinical Dementia Rating (CDR) = 1], 42 meeting Petersen's criteria for MCI [CDR = 0.5], and 37 cognitively intact controls [CDR = 0]) was recruited for the study in the university-based Alzheimer out-patient clinic. All participants underwent general medical, neurological, and psychiatric examinations. The MoCA, the MMSE, CDR and the short (15-item) version of the Geriatric Depression Scale were also applied. Results Both MCI and AD groups exhibited impaired performance on MoCA compared to controls. Polish versions of the MMSE and MoCA tests were comparable in discriminating mild dementia from both MCI and control groups. The Polish version of the MoCA test performed marginally better than MMSE in discriminating MCI from controls. We propose to use the MoCA test to screen for MCI using an optimal cut-off score of 24 and to screen for dementia using a cut-off score of 19. Conclusions The Polish version of the MoCA seems effective in the detection of deteriorated cognitive performance and appropriate for differentiating impaired from preserved cognitive function in a Polish population.Wstęp i cel pracy Montrealski Test do Oceny Stanu Poznawczego (Montreal Cognitive Assessment – MoCA) jest narzędziem do przesiewowej oceny stanu poznawczego i cechuje się dużą czułością oraz swoistością w wykrywaniu łagodnych zaburzeń poznawczych (mild cognitive impairment – MCI). Celem pracy była ocena przydatności testu MoCA oraz porównanie z Krótką Skalą Oceny Stanu Psychicznego (Mini-Mental State Examination – MMSE) we wczesnym wykrywaniu łagodnych zaburzeń poznawczych. Materiał i metody Przeprowadzono badanie z użyciem polskiej wersji testu w grupie 115 osób, w tym 36 chorych na chorobę Alzheimera o nasileniu łagodnym wg DSM-IV [Clinical Dementia Rating (CDR) = 1], 42 pacjentów z MCI (CDR = 0,5) oraz 37 zdrowych osób w grupie kontrolnej (CDR = 0) – pacjentów poradni przyklinicznej o profilu psychogeriatrycznym. U wszystkich uczestników projektu przeprowadzono ocenę ogólnego stanu somatycznego, badanie neurologiczne i psychiatryczne oraz dokonano oceny z użyciem MoCA, MMSE, CDR oraz 15-punktowej wersji Geriatrycznej Skali Depresji (Geriatric Depression Scale). Wyniki Zarówno pacjenci z MCI, jak i z chorobą Alzheimera wykonali test MoCA gorzej w porównaniu z osobami z grupy kontrolnej. W badanej populacji testy MMSE i MoCA okazały się porównywalne w odróżnianiu otępienia o nasileniu łagodnym od MCI i osób zdrowych. Wykazano minimalną przewagę polskiej wersji testu MoCA nad MMSE w odróżnianiu osób z MCI od grupy kontrolnej. Autorzy proponują stosowanie testu MoCA jako narzędzia przesiewowego do wykrywania zaburzeń poznawczych i stosowanie punktu odcięcia na poziomie 24 punktów dla łagodnych zaburzeń poznawczych oraz 19 punktów dla otępienia. Wnioski Wykazano przydatność polskiej wersji testu MoCA w wykrywaniu deficytów poznawczych i odróżnianiu osób z MCI od osób zdrowych w polskiej populacji

Modifying the product distribution of a reaction within the controlled microenvironment of a colloidosome

A water-soluble colloidosome composed of PGMA–PS latex was used as a microcapsule to host a catalyzed oxidation reaction within its dodecane core. When compared to a control reaction a significant colloidosome effect was observed. Specifically, a 233% increase in the relative yield of all products was observed for the colloidosome reaction. Furthermore, when the product distributions were calculated it was evident that a switch in selectivity had taken place. These studies showed there is a significant reduction in the relative yield of the epoxide product compared to the remaining oxidation products. Additional control experiments confirmed that rate enhancements were not simply a result of concentration and that reactions were not occurring in the outer latex phase. As a consequence of these control experiments, we suggest that the colloidosome enhancement and shift in product distribution, comes about from differences in electronic environment at or close to the interface between the internal oil phase and the outer colloidal particles. This environment is able to stabilize any specific intermediates and or transition states leading to enhanced reactions for these products and higher relative yields

Universal Negative Poisson Ratio of Self Avoiding Fixed Connectivity Membranes

We determine the Poisson ratio of self-avoiding fixed-connectivity membranes, modeled as impenetrable plaquettes, to be sigma=-0.37(6), in statistical agreement with the Poisson ratio of phantom fixed-connectivity membranes sigma=-0.32(4). Together with the equality of critical exponents, this result implies a unique universality class for fixed-connectivity membranes. Our findings thus establish that physical fixed-connectivity membranes provide a wide class of auxetic (negative Poisson ratio) materials with significant potential applications in materials science.Comment: 4 pages, 3 figures, LaTeX (revtex) Published version - title changed, one figure improved and one reference change

Dynamics at a smeared phase transition

We investigate the effects of rare regions on the dynamics of Ising magnets with planar defects, i.e., disorder perfectly correlated in two dimensions. In these systems, the magnetic phase transition is smeared because static long-range order can develop on isolated rare regions. We first study an infinite-range model by numerically solving local dynamic mean-field equations. Then we use extremal statistics and scaling arguments to discuss the dynamics beyond mean-field theory. In the tail region of the smeared transition the dynamics is even slower than in a conventional Griffiths phase: the spin autocorrelation function decays like a stretched exponential at intermediate times before approaching the exponentially small equilibrium value following a power law at late times.Comment: 10 pages, 8eps figures included, final version as publishe

Fluctuation-Induced Interactions between Rods on a Membrane

We consider the interaction between two rods embedded in a fluctuating surface. The modification of fluctuations by the rods leads to an attractive long-range interaction between them. We consider fluctuations governed by either surface tension (films) or bending rigidity (membranes). In both cases the interaction falls off with the separation of the rods as $1/R^4$. The orientational part of the interaction is proportional to $\cos^2\left[ \theta_1+\theta_2 \right]$ in the former case, and to $\cos^2\left[ 2\left(\theta_1+\theta_2\right) \right]$ in the latter, where $\theta_1$ and $\theta_2$ are angles between the rods and the line joining them. These interactions are somewhat reminiscent of dipolar forces and will tend to align collections of such rods into chains.Comment: REVTEX, 14 pages, with 2 Postscript figure

X-ray Diffraction Residual Stress Measurement at Room Temperature and 77 K in a Microelectronic Multi-layered Single-Crystal Structure Used for Infrared Detection

The electronic assembly considered in this study is an infrared (IR) detector consisting of different layers, including (111) CdHgTe and (100) silicon single crystals. The processing steps and the low working temperature (77 K) induce thermomechanical stresses that can affect the reliability of the thin and brittle CdHgTe detection circuit and lead to failure. These residual stresses have been quantified in both CdHgTe and silicon circuits at room temperature (293 K) and cryogenic temperature using x-ray diffraction. A specific experimental device has been developed for 77 K measurements and a method developed for single-crystal analysis has been adapted to such structures using a laboratory four-circle diffractometer. This paper describes the methodology to obtain the deformed lattice parameter and compute the strain/ stress tensors. Whereas the stresses in the CdHgTe layer appear to be negative at room temperature (compressive values), cryogenic measurements show a tensile biaxial stress state of about 30 MPa and highlight the great impact of low temperature on the mechanical properties

Distinguishing between pre- and post-treatment in the speech of patients with chronic obstructive pulmonary disease

Chronic obstructive pulmonary disease (COPD) causes lung inflammation and airflow blockage leading to a variety of respiratory symptoms; it is also a leading cause of death and affects millions of individuals around the world. Patients often require treatment and hospitalisation, while no cure is currently available. As COPD predominantly affects the respiratory system, speech and non-linguistic vocalisations present a major avenue for measuring the effect of treatment. In this work, we present results on a new COPD dataset of 20 patients, showing that, by employing personalisation through speaker-level feature normalisation, we can distinguish between pre- and post-treatment speech with an unweighted average recall (UAR) of up to 82\,\% in (nested) leave-one-speaker-out cross-validation. We further identify the most important features and link them to pathological voice properties, thus enabling an auditory interpretation of treatment effects. Monitoring tools based on such approaches may help objectivise the clinical status of COPD patients and facilitate personalised treatment plans.Comment: Accepted in INTERSPEECH 202

Total oxidation of propene at low temperature over Co3O4-CeO2 mixed oxides: Role of surface oxygen vacancies and bulk oxygen mobility in the catalytic activity

Co3O4, CeO2 and Co3O4\u2013CeO2 mixed oxides with Co/Ce nominal atomic ratio 0.1:5, prepared by coprecipitation method with sodium carbonate, were tested in the oxidation of propene under lean condition and the catalyst stability was checked by performing three consecutive heating\u2013cooling cycles. Characterization of the textural properties were performed by surface area measurement BET, X-ray diffraction (XRD) and scanning electron microscopy (SEM) measurements. Among the Co3O4\u2013CeO2 mixed oxides, Co3O4 (30 wt%)\u2013CeO2 (70 wt%) gives the best activity attaining full propene conversion at 250 \ub0C. This sample is characterized by the presence of Co3O4 particles well dispersed and in good contact with ceria according to BET and XRD data and as evidenced by SEM micrographs. Oxygen temperature-programmed desorption (O2 -TPD) and C3H6 -temperature-programmed reduction (C3H6-TPR) experiments were carried out in order to study the surface and bulk oxygen mobility and to correlate it to the activity. At temperature around 200 \ub0C, O2-TPD experiments showed the desorption of mobile surface oxygen species for the most active samples, Co3O4 and Co3O4 (30 wt%)\u2013 CeO2 (70 wt%). C3H6-TPR experiments for both of the oxides also evidenced a high reactivity at low temperature, especially, for Co3O4 (30 wt%)\u2013 CeO2 (70 wt%) giving at 345 \ub0C an intense peak of CO2 formation. Conversely, the ceria sample showed by C3H6-TPR much less pronounced oxygen bulk mobility, starting to react with propene above 500 \ub0C and forming only CO. In this case, the catalytic activity of ceria was explained in terms of formation of surface oxygen vacancies which are relevant to the propene oxidation in presence of gaseous oxygen