Data analysis with ordinal and interval dependent variables: examples from a study of real estate salespeople

This paper re-examines the problems of estimating the parameters of an underlying linear model using survey response data in which the dependent variables are in discrete categories of ascending order (ordinal, as distinct from numerical) or, where they are observed to fall into certain groups on a continuous scale (interval), where the actual values remain unobserved. An ordered probit model is discussed as an appropriate framework for statistical analysis for ordinal dependent variables. Next, a maximum likelihood estimator (MLE) derived from grouped data regression for interval dependent variable is discussed. Using LIMDEP, a packaged statistical program, survey data from an earlier manuscript are analyzed and the findings presented.

A Comparison of Warm-Up Modalities on Upper Body Force Production Measures

Warm-ups are often initiated before an athletic event in order to prepare the athlete’s body for competition by increasing blood flow to the working muscles. When a warm-up also activates nerve-muscle function, producing a level of high-intensity power even after the muscle contraction occurs, it is known as post-activation potentiation (PAP). Most PAP warm-ups include high-load, low-velocity conditioning contractions whereas a low-load, high-velocity conditioning contraction may be a more user-friendly warm-up. Therefore, the purpose of this study was to investigate the effects of PAP after low-load, high-velocity conditioning contractions on subsequent upper body power exercises. Ten recreationally trained males (age: 23.2 yrs; height: 178.1 cm; mass: 88.3 kg; see Table 1) volunteered to participate in three testing sessions, each separated by 24-48 hours. The testing conditions were 10% of 1RM bench press and 20% 1RM bench press. After the conditioning contraction, participant’s performed a plyometric push-up immediately after and then 4- and 8-minutes after the warm-up. The plyometric push-up was performed on a force platform in order to gather the dependent variables: ground reaction force, normalized ground reaction force, and rate of force development. No main effect or interaction was found for any variables (p>.05). Subjects showed no strength improvements after performing the conditioning contractions, and further research must be done in order to validate other research on low-load, high-velocity conditioning contractions

Generation of Hyperentangled Photons Pairs

We experimentally demonstrate the first quantum system entangled in every degree of freedom (hyperentangled). Using pairs of photons produced in spontaneous parametric downconversion, we verify entanglement by observing a Bell-type inequality violation in each degree of freedom: polarization, spatial mode and time-energy. We also produce and characterize maximally hyperentangled states and novel states simultaneously exhibiting both quantum and classical correlations. Finally, we report the tomography of a 2x2x3x3 system (36-dimensional Hilbert space), which we believe is the first reported photonic entangled system of this size to be so characterized.Comment: 5 pages, 3 figures, 1 table, published versio

Role of (p)ppGpp in Viability and Biofilm Formation of Actinobacillus pleuropneumoniae S8.

Actinobacillus pleuropneumoniae is a Gram-negative bacterium and the cause of porcine pleuropneumonia. When the bacterium encounters nutritional starvation, the relA-dependent (p)ppGpp-mediated stringent response is activated. The modified nucleotides guanosine 5'-diphosphate 3'-diphosphate (ppGpp) and guanosine 5'-triphosphate 3'-diphosphate (pppGpp) are known to be signaling molecules in other prokaryotes. Here, to investigate the role of (p)ppGpp in A. pleuropneumoniae, we created a mutant A. pleuropneumoniae strain, S8ΔrelA, which lacks the (p)ppGpp-synthesizing enzyme RelA, and investigated its phenotype in vitro. S8ΔrelA did not survive after stationary phase (starvation condition) and grew exclusively as non-extended cells. Compared to the wild-type (WT) strain, the S8ΔrelA mutant had an increased ability to form a biofilm. Transcriptional profiles of early stationary phase cultures revealed that a total of 405 bacterial genes were differentially expressed (including 380 up-regulated and 25 down-regulated genes) in S8ΔrelA as compared with the WT strain. Most of the up-regulated genes are involved in ribosomal structure and biogenesis, amino acid transport and metabolism, translation cell wall/membrane/envelope biogenesis. The data indicate that (p)ppGpp coordinates the growth, viability, morphology, biofilm formation and metabolic ability of A. pleuropneumoniae in starvation conditions. Furthermore, S8ΔrelA could not use certain sugars nor produce urease which has been associated with the virulence of A. pleuropneumoniae, suggesting that (p)ppGpp may directly or indirectly affect the pathogenesis of A. pleuropneumoniae during the infection process. In summary, (p)ppGpp signaling represents an essential component of the regulatory network governing stress adaptation and virulence in A. pleuropneumoniae

The Effects of U.S.S.R. on Students\u27 Attitudes and Achievements

The program called Uninterrupted Sustained Silent Reading (USSR or SSR) is widely advocated, sometimes under other names (Moore, Jones, and Miller, 1980), as a program which should help foster positive attitudes toward reading as well as help improve reading achievement (Hunt, 1972; Mork, 1972; McCracken, 1971; Noland, 1976). USSR incorporates attributes mentioned by many writers as valuable for the development of favorable attitudes and increased achievement: a specific time set aside for reading at regular intervals; a large quantity and wide variety of reading materials available; provision of a role model in that the teacher and other adults in the school show their value of reading by participating along with the children; encouragement to read by these adults; a pleasant, relaxed atmosphere; lack of pressure to report on what has been read; and the opportunity to share information about books read, if desired. Many authorities believe that these ingredients cannot fail to produce more favorable attitudes toward reading as well as increased reading achievement

Quantum process tomography of a controlled-NOT gate

We demonstrate complete characterization of a two-qubit entangling process - a linear optics controlled-NOT gate operating with coincident detection - by quantum process tomography. We use maximum-likelihood estimation to convert the experimental data into a physical process matrix. The process matrix allows accurate prediction of the operation of the gate for arbitrary input states, and calculation of gate performance measures such as the average gate fidelity, average purity and entangling capability of our gate, which are 0.90, 0.83 and 0.73, respectively.Comment: 4 pages, 2 figures. v2 contains new data corresponding to improved gate operation. Figure quality slightly reduced for arXi

Manipulating biphotonic qutrits

Quantum information carriers with higher dimension than the canonical qubit offer significant advantages. However, manipulating such systems is extremely difficult. We show how measurement induced non-linearities can be employed to dramatically extend the range of possible transforms on biphotonic qutrits; the three level quantum systems formed by the polarisation of two photons in the same spatio-temporal mode. We fully characterise the biphoton-photon entanglement that underpins our technique, thereby realising the first instance of qubit-qutrit entanglement. We discuss an extension of our technique to generate qutrit-qutrit entanglement and to manipulate any bosonic encoding of quantum information.Comment: 4 pages, 4 figure

Demonstration of a simple entangling optical gate and its use in Bell-state analysis

We demonstrate a new architecture for an optical entangling gate that is significantly simpler than previous realisations, using partially-polarising beamsplitters so that only a single optical mode-matching condition is required. We demonstrate operation of a controlled-Z gate in both continuous-wave and pulsed regimes of operation, fully characterising it in each case using quantum process tomography. We also demonstrate a fully-resolving, nondeterministic optical Bell-state analyser based on this controlled-Z gate. This new architecture is ideally suited to guided optics implementations of optical gates.Comment: 4 pages, 3 figures. v2: additional author, improved data and figures (low res), some other minor changes. Accepted for publication in PR