Estimability and efficiency in nearly orthogonal 2[m1] x 3[m2] deletion designs

This article considers single replicate factorial experiments in incomplete blocks. A single replicate 2^m1 x 3^m2 deletion design in 3 incomplete blocks is obtained from a single replicate 3^m, where m = m_1 + m_2, preliminary design by deleting all runs (or treatment combinations) with the first m_1 factors at the level two. A systematic method for determining the unbiasedly estimable (u.e.) and not unbiasedly estimable (n.u.e.) factorial effects is provided. It is shown that for m_2 > 0 all factorial effects of the type F( α_1 · · · α_m_1 , α_(m_1 +1) · · · α_m), where α_i; = 0, l for i = 1, · · ·, m_1, α_i; = 0, 1, 2 for i = m_(1+1), · · ·, m, with (α_1 · · · α_m) != (0 · · · 0), and (α_m,+l · · · _m) != α(l · · · 1) for a= 1, 2, are u.e. and the remaining factorial effects are n.u.e. It is noted that (2^m_1 - 1) factorial effects of 2^m_1 factorial experiments and (3^m_2) factorial effects of 3^m, factorial experiments, which are embedded in 2^m_1 x 3^m, factorial experiments, are u. e. The 2 x 3m-l deletion designs were considered in the work of Voss (1986). Defining factorial effects of a 2^m_1 x 3^m, factorial experiment in a form different than in Voss (1986), we develop a simple representation of u.e. and n. u. e. factorial effects. In this representation, there are (2^(m_1 + 1) + 1) n. u. e. factorial effects of the type F( α_1 · · · α_m_1, α· · · α). This number is smaller than the corresponding number of n. u. e. factorial effects in the representation of Voss (1986). The relative efficiency expressions, and their bounds, in the estimation of factorial effects of 2^m_1 x 3^m_2 deletion designs are also given

Inversion of stellar statistics equation for the Galactic Bulge

A method based on Lucy (1974, AJ 79, 745) iterative algorithm is developed to invert the equation of stellar statistics for the Galactic bulge and is then applied to the K-band star counts from the Two-Micron Galactic Survey in a number of off-plane regions (10 deg.>|b|>2 deg., |l|<15 deg.). The top end of the K-band luminosity function is derived and the morphology of the stellar density function is fitted to triaxial ellipsoids, assuming a non-variable luminosity function within the bulge. The results, which have already been outlined by Lopez-Corredoira et al.(1997, MNRAS 292, L15), are shown in this paper with a full explanation of the steps of the inversion: the luminosity function shows a sharp decrease brighter than M_K=-8.0 mag when compared with the disc population; the bulge fits triaxial ellipsoids with the major axis in the Galactic plane at an angle with the line of sight to the Galactic centre of 12 deg. in the first quadrant; the axial ratios are 1:0.54:0.33, and the distance of the Sun from the centre of the triaxial ellipsoid is 7860 pc. The major-minor axial ratio of the ellipsoids is found not to be constant. However, the interpretation of this is controversial. An eccentricity of the true density-ellipsoid gradient and a population gradient are two possible explanations. The best fit for the stellar density, for 1300 pc<t<3000 pc, are calculated for both cases, assuming an ellipsoidal distribution with constant axial ratios, and when K_z is allowed to vary. From these, the total number of bulge stars is ~ 3 10^{10} or ~ 4 10^{10}, respectively.Comment: 19 pages, 23 figures, accepted in MNRA

The relationship of individual comorbid chronic conditions to diabetes care quality.

ObjectiveMultimorbidity affects 26 million persons with diabetes, and care for comorbid chronic conditions may impact diabetes care quality. The aim of this study was to determine which chronic conditions were related to lack of achievement or achievement of diabetes care quality goals to determine potential targets for future interventions.Research design and methodsThis is an exploratory retrospective analysis of electronic health record data for 23 430 adults, aged 18-75, with diabetes who were seen at seven Midwestern US health systems. The main outcome measures were achievement of six diabetes quality metrics in the reporting year, 2011 (glycated haemoglobin (HbA1c) control and testing, low-density lipoprotein control and testing, blood pressure control, kidney testing). Explanatory variables were 62 chronic condition indicators. Analyses were adjusted for baseline patient sociodemographic and healthcare utilization factors.ResultsThe 62 chronic conditions varied in their relationships to diabetes care goal achievement for specific care goals. Congestive heart failure was related to lack of achievement of cholesterol management goals. Obesity was related to lack of HbA1c and BP control. Mental health conditions were related to both lack of achievement and achievement of different care goals. Three conditions were related to lack of cholesterol testing, including congestive heart failure and substance-use disorders. Of 17 conditions related to achieving control goals, 16 were related to achieving HbA1c control. One-half of the comorbid conditions did not predict diabetes care quality.ConclusionsFuture interventions could target patients at risk for not achieving diabetes care for specific care goals based on their individual comorbidities

Factors Associated with Diabetes Risk in South Texas College Students

International Journal of Exercise Science 7(2) : 110-118, 2014. South Texas has a high prevalence of diabetes and college students may be particularly at risk. While increased BMI, sedentary activity and depression have been associated with diabetes progression in the general population, it has not been established whether these factors contribute to increased diabetes risk in college students. The purpose of this study was to assess diabetes risk and determine whether depressive symptoms or physical activity patterns are associated with increased diabetes risk in college students. Sixty-nine college students were assessed for diabetes risk using the Finnish Diabetes Risk Score (FINDRISC) . Each participant completed the International Physical Activity Questionnaire (IPAQ) which included a sitting subscale, the Zung Self-Rated Depression Scale, and had anthropometric measures taken. Of the participants, 21.7% reported elevated risk (FINDRISC score 7-11), and 4.3% of participants had a moderate-to-high risk of developing diabetes (FINDRISC \u3e12). On average, the sample was overweight (BMI = 26.81±0.75 kg . m-2), and BMI was associated with diabetes risk (r = 0.626, p \u3c 0.001). While diabetes risk was not correlated with IPAQ total physical activity score (r = 0.019, p = 0.874), it was modestly correlated with time spent sitting (r = 0.295, p = 0.015). There was no association between self-reported depressive symptoms and diabetes risk (r =0.078, p = 0.525). Although diabetes risk was not associated with total activity and depressive symptoms, it was associated with time spent sitting and BMI. These results suggest that in this population, sitting less and reducing weight may help lower the risk of developing diabetes

The usefulness of feedback

Feedback can occur before and after assessment submission, but needs to be useful in order for students to improve their subsequent performance. Arguably, undergraduate students, and particularly international, online and new students, are especially in need of feedback to effectively engage in academic and disciplinary expectations. Therefore, this article draws on survey data from students, disaggregated by mode of study, citizenship of enrolment and year of study, to explore their experiences of feedback usefulness both before and after assessment submission. Overall, undergraduate students were positive; however, this perception decreased according to their year level. Comparisons between online and international students also revealed key differences. A conclusion is that undergraduate students cannot be treated homogeneously, and educators need to attend to the feedback experiences of different student groups as they progress through their programme

What makes for effective feedback: staff and student perspectives

Since the early 2010s the literature has shifted to view feedback as a process that students do where they make sense of information about work they have done, and use it to improve the quality of their subsequent work. In this view, effective feedback needs to demonstrate effects. However, it is unclear if educators and students share this understanding of feedback. This paper reports a qualitative investigation of what educators and students think the purpose of feedback is, and what they think makes feedback effective. We administered a survey on feedback that was completed by 406 staff and 4514 students from two Australian universities. Inductive thematic analysis was conducted on data from a sample of 323 staff with assessment responsibilities and 400 students. Staff and students largely thought the purpose of feedback was improvement. With respect to what makes feedback effective, staff mostly discussed feedback design matters like timing, modalities and connected tasks. In contrast, students mostly wrote that high-quality feedback comments make feedback effective – especially comments that are usable, detailed, considerate of affect and personalised to the student’s own work. This study may assist researchers, educators and academic developers in refocusing their efforts in improving feedbac

UV Degradation of the Optical Properties of Acrylic for Neutrino and Dark Matter Experiments

UV-transmitting (UVT) acrylic is a commonly used light-propagating material in neutrino and dark matter detectors as it has low intrinsic radioactivity and exhibits low absorption in the detectors' light producing regions, from 350 nm to 500 nm. Degradation of optical transmittance in this region lowers light yields in the detector, which can affect energy reconstruction, resolution, and experimental sensitivities. We examine transmittance loss as a result of short- and long-term UV exposure for a variety of UVT acrylic samples from a number of acrylic manufacturers. Significant degradation peaking at 343 nm was observed in some UVT acrylics with as little as three hours of direct sunlight, while others exhibited softer degradation peaking at 310 nm over many days of exposure to sunlight. Based on their measured degradation results, safe time limits for indoor and outdoor UV exposure of UVT acrylic are formulated.Comment: 13 pages, 6 figures, 3 tables; To be submitted to Journal of Instrumentatio

Effect of water-wall interaction potential on the properties of nanoconfined water

Much of the understanding of bulk liquids has progressed through study of the limiting case in which molecules interact via purely repulsive forces, such as a hard-core potential. In the same spirit, we report progress on the understanding of confined water by examining the behavior of water-like molecules interacting with planar walls via purely repulsive forces and compare our results with those obtained for Lennard-Jones (LJ) interactions between the molecules and the walls. Specifically, we perform molecular dynamics simulations of 512 water-like molecules which are confined between two smooth planar walls that are separated by 1.1 nm. At this separation, there are either two or three molecular layers of water, depending on density. We study two different forms of repulsive confinements, when the interaction potential between water-wall is (i) $1/r^9$ and (ii) WCA-like repulsive potential. We find that the thermodynamic, dynamic and structural properties of the liquid in purely repulsive confinements qualitatively match those for a system with a pure LJ attraction to the wall. In previous studies that include attractions, freezing into monolayer or trilayer ice was seen for this wall separation. Using the same separation as these previous studies, we find that the crystal state is not stable with $1/r^9$ repulsive walls but is stable with WCA-like repulsive confinement. However, by carefully adjusting the separation of the plates with $1/r^9$ repulsive interactions so that the effective space available to the molecules is the same as that for LJ confinement, we find that the same crystal phases are stable. This result emphasizes the importance of comparing systems only using the same effective confinement, which may differ from the geometric separation of the confining surfaces.Comment: 20 pages, 10 figure

Synchronization and Control in Intrinsic and Designed Computation: An Information-Theoretic Analysis of Competing Models of Stochastic Computation

We adapt tools from information theory to analyze how an observer comes to synchronize with the hidden states of a finitary, stationary stochastic process. We show that synchronization is determined by both the process's internal organization and by an observer's model of it. We analyze these components using the convergence of state-block and block-state entropies, comparing them to the previously known convergence properties of the Shannon block entropy. Along the way, we introduce a hierarchy of information quantifiers as derivatives and integrals of these entropies, which parallels a similar hierarchy introduced for block entropy. We also draw out the duality between synchronization properties and a process's controllability. The tools lead to a new classification of a process's alternative representations in terms of minimality, synchronizability, and unifilarity.Comment: 25 pages, 13 figures, 1 tabl