4,129 research outputs found
The human adenovirus 5 L4 promoter is activated by cellular stress response protein p53
During adenovirus infection, the emphasis of gene expression switches from early genes to late genes in a highly regulated manner. Two gene products, L4-22K and L4-33K, contribute to this switch by activating the Major Late Transcription Unit (MLTU) and regulating the splicing of its transcript. L4-22K and L4-33K expression is driven initially by a recently described L4 promoter (L4P) embedded within the MLTU that is activated by early and intermediate viral factors: E1A, E4 Orf3 and IVa2. Here we show that this promoter is also significantly activated by the cellular stress response regulator, p53. Exogenous expression of p53 activated L4P in reporter assays whilst depletion of endogenous p53 inhibited the induction of L4P by viral activators. Chromatin immunoprecipitation studies showed that p53 associates with L4P and that during adenovirus type 5 (Ad5) infection this association peaks at 12 h.p.i., coinciding with the phase of the infectious cycle when L4P is active, and is then lost as MLP activation commences. P53 activation of L4P is significant during Ad5 infection since depletion of p53 prior to infection of either immortalised or normal cells led to severely reduced late gene expression. The association of p53 with L4P is transient due to the action of products of L4P activity (L4-22K/33K), which establish a negative feedback loop that ensures the transient activity of L4P at the start of the late phase and contributes to an efficient switch from early to late phase virus gene expression
Improvements for Differential Functioning of Items and Tests (DFIT): Investigating the Addition of Reporting an Effect Size Measure and Power
Standardized testing has been part of the American educational system for decades. Controversy from the beginning has plagued standardized testing, is plaguing testing today, and will continue to be controversial. Given the current federal educational policies supporting increased standardized testing, psychometricians, educators and policy makers must seek ways to ensure that tests are not biased towards one group over another.
In measurement theory, if a test item behaves differently for two different groups of examinees, this test item is considered a differential functioning test item (DIF). Differential item functioning, often conceptualized in the context of item response theory (IRT) is a term used to describe test items that may favor one group over another after matched on ability. It is important to determine whether an item is functioning significantly different for one group over another regardless as to why. Hypothesis testing is used to determine statistical significant DIF items; an effect size measure quantifies a statistical significant difference.
This study investigated the addition of reporting an effect size measure for differential item functioning of items and tests’ (DFIT) noncompensatory differential item functioning (NCDIF), and reporting empirically observed power. The Mantel-Haenszel (MH) parameter served as the benchmark for developing NCDIF’s effect size measure, for reporting moderate and large differential item functioning in test items. In addition, by modifying NCDIF’s unique method for determining statistical significance, NCDIF will be the first DIF statistic of test items where in addition to reporting an effect size measure, empirical power can also be reported.
Furthermore, this study added substantially to the body of literature on effect size by also investigating the behavior of two other DIF measures, Simultaneous Item Bias Test (SIBTEST) and area measure. Finally, this study makes a significant contribution to the body of literature by verifying in a large-scale simulation study, the accuracy of software developed by Roussos, Schnipke, and Pashley (1999) to calculate the true MH parameter. The accuracy of this software had not been previously verified
The Trouble With Online Undergraduate Business Degrees In Traditional Regional Universities
Because of the surging demand for undergraduate business degrees and the increasing availability of effective online educational content, many traditional regional universities have added, or are now considering adding, online undergraduate business degree programs to their classroom programs. Through a review of the literature bearing on that decision, this paper enumerates many of the heretofore-unreported risks unique to such programs and suggests methods to mitigate these risks. The paper argues that online undergraduate business degree programs in traditional regional universities, if not carefully promoted and managed, can be so troublesome that they are unlikely to add long-term economic value to either the community or the university. The arguments presented in this paper suggest many future areas for empirical work
A New Uncertainty Calculus For Rule-Based Expert Systems
The solution of non-deterministic expert systems consists of two components –the solution reached and a calculated measure of belief in each solution. This measure of belief is often the most critical factor in analyzing the solution. Unfortunately, as this paper reviews, the issue of how best to implement uncertainty calculi in expert systems has never been settled. Some popular rule-based approaches have in fact been shown to produce results no better than random guessing. To improve the accuracy of rule-based systems, we propose a new calculus we call gamma factors. This calculus combines ideas from two popular certainty factor calculi the product method, and the probability sum method. It includes a tuning mechanism which the expert can use in a rule pre-processing step to compensate for dependent parallel evidence combination
Status of the Plains Harvest Mouse (\u3ci\u3eReithrodontomys montanus griseus\u3c/i\u3e) in eastern Nebraska
In eastern Nebraska, current status of the Plains Harvest Mouse (Reithrodontomys montanus griseus) is not well understood. Infrequent captures during the last century have led to a paucity of information regarding this taxon, and some researchers postulate that its distribution has contracted in the state. In 2008, we conducted a field survey for R. m. griseus in eastern Nebraska, amassed prior specimen records, and examined most of the specimens for this subspecies from the state to better understand its distribution, natural history, and subspecific status. In our field efforts, we only captured a single individual despite \u3e 8,000 trap nights in suitable habitats. Our literature review and queries for vouchers yielded 20 specimens of R. m. griseus from eastern Nebraska, based on published distributional limits for this subspecies. In eastern Nebraska, R. m. griseus has been captured in tallgrass prairies, short-grass upland pastures, roadside ditches, and open areas associated with salt flats. Observations across eastern Nebraska in the last 40 years demonstrate that this taxon still exists across the entire region and has been captured more frequently in cooler months. We suspect that some combination of low abundance, trap shyness, and trapping biases towards heavily vegetated habitats and warm seasons likely has led to infrequent captures of R. m. griseus in eastern Nebraska. After examination of many museum specimens of this species from across Nebraska, Kansas, and Missouri, we questioned the delineations in distribution for the two subspecies in the region. On the basis of dorsal gray fur coloration, R. m. albescens appears limited to the Sandhill and Panhandle regions of Nebraska, whereas all of eastern and southern Nebraska as well as Kansas and western Missouri represent R. m. griseus, a subspecies with brown dorsal fur coloration. Based on our proposed distributional changes for these two subspecies in Nebraska, we do not find that either subspecies requires conservation efforts. Reithrodontomys montanus griseus likely will persist at low densities throughout eastern Nebraska in appropriate habitats and persist at higher densities farther westward in southern parts of the state. Reithrodontomys montanus albescens always has been more common in the Sandhill Region of Nebraska, as individuals still are observed and captured with regularity
Inexpensive Intelligence Using Procedural Propositional Logic
Implementations of inference engine systems invoke many costs, including the cost of the inference engine itself, the cost of integrating the inference engine, and the cost of specialized personnel needed to create and maintain the system. These costs make a very high return on investment a criterion for incorporating these systems into the corporate portfolio of applications and technologies. Recently, the No Inference Engine Theory (NIET) [8] has been developed for creating procedural propositional logic rule-based systems. The NIET systems are implemented in traditional procedural languages such as C++ and do not need an inference engine or proprietary languages, thus eliminating the cost of the inference engine, the cost of integrating the system, and the cost for knowledge of a proprietary language. In addition, these procedural systems are an order of magnitude faster [8] than inference systems and maintain linear performance. For problems using propositional logic, the procedural systems described in this paper offer dramatically lower costs, higher performance, and ease of integration. Lowering the external costs and eliminating the need for specialized skills should make NIET systems more profitable and lead to the wider use of propositional logic systems in business
Mathematics summer schools for acoustics research training
Mathematical methods are important for research in many aspects of acoustics. Most researchers in acoustics in the United Kingdom do not have access to master level courses to broaden their postgraduate study, so they advance their fundamental mathematical methodologies taught at under-graduate level through independent learning. They develop their mathematical skills as appropriate rather than being made aware of the potential of advanced mathematical tools at the onset of their research career. Attempts to improve this situation were made through summer schools held in 2003 and 2005 at Southampton University and in 2007 at Salford University. The background to these Summer Schools, their content and structure, recruitment figures and student feedback are reported together with conclusions about their performance and role particularly in respect of PhD completion
Emulation of modular manufacturing machines using CAD modelling
Designing, testing and debugging a machine control system which controls mechatronic hardware elements can be a complex, time consuming and costly procedure. It is often extremely difficult for the system builder to envisage in advance the effects of small changes to the control system logic, with potentially dangerous results if the hardware consists of heavy machinery. It is also rare that a system builder will arrive at a working prototype on the first attempt and discovering the reasons for incorrect operation without a suitable means of comprehending the problems can be an arduous task. This paper describes an approach which supports the designing, testing and debugging of modular manufacturing machines using 3D graphical models of the machine hardware. The paper emphasises the underlying methodology of the approach, which involves collecting timing data from the executing control system under development, then emulating the operation of the machine by using this data to drive a graphical model of the hardware. The term “emulation” is used to mean modelling using data captured from the real machine as opposed to “simulation” which synthesises data.
The work builds on previous research at the MSI Research Institute concerned with the control of modular machines. Two new extensions to this work are described here, which form the basis of the emulation capability. The first is the addition of the ability to execute the control system without the mechatronic hardware elements present whilst still retaining the operational behaviour of the application. The second is the mechanism for collecting the run-time data which defines these operational characteristics, to drive the machine emulation. The features of the custom 3D modeller are presented and its use for machine emulation is described. An example of a real control system under development is given to illustrate the complete process.
The research objectives of the work described here are concerned with the fundamental problems designers encounter when trying to prototype the control systems of modular machines. The research has shown that the ability to execute the control system with or without the mechatronic hardware elements present can be a considerable advantage if supported by a CAD-based emulation system
Simplified Preliminary Blood Testing--An Improved Technique and a Comparative Study of Methods
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