The adequacy of the theories of deductive systems with respect to sentential calculi

Summary The sentential calculiR, under discussion, are axiomatizable and implication is among their primitive terms. The modus ponens and the rule of substitution are their primitive rules. ByS _r is denoted the set of sentences obtained from the formulae of the calculusR by substituting sentences of a given language for all variables. The variablesx, y, z ... represent the elements of the setS _r , the variablesX, Y, Z ... represent the subsets ofS _R . The formulacxy designates an implication withx as its antecedent andy as its consequent,cxy is always an element ofS _R δ(X) means, thatX is closed with respect to the modus ponens rule.A _R designates the class of allS _R -substitutions of the axioms of the sentential calculusR.     

Decision policies minimizing risk in a multistage betting game

Considered in this paper is a decision task which has been employed to study multistage betting behavior. When the task commences, a decision maker (DM) is provided with some capital x (x > 0) which he is required to allocate over m (m > 1) mutually exclusive and collectively exhaustive alternatives, each of which occurs with probability p_i (p_i > 0, i = 1,…, m; Σ_i=1^mp_i = 1). If the amount y_i is allocated to alternative i (y_i ≥ 0, Σ_i=1^my_i = x) and alternative i obtains, DM's capital for the next stage of the game becomes y_ir_i, where r_i (r_i > 0) is the return per unit allocated to alternative i. The task consists of N stages.Defining risk in terms of the mean and variance of DM's bets, and assuming that the minimization of risk is DM's objective, decision policies satisfying this objective are derived in closed form and their testable properties are briefly discussed.     

Context-dependent Abduction and Relevance

Based on the premise that what is relevant, consistent, or true may change from context to context, a formal framework of relevance and context is proposed in which

Prevalence,correlates, and psychosocial outcomes of sport participation in young adult cancer survivors

Young adult cancer survivors (YACS) face unique challenges from their disease and treatments that may influence their sport participation choices as well as their psychosocial response.ObjectivesTo examine the prevalence, correlates, and psychosocial outcomes of sport participation in YACS.DesignA provincial, population-based mailed survey of 588 YACS in Alberta, Canada, was completed in May 2008 and included measures of sport participation, psychosocial health (depression, self-esteem, and stress), quality of life (QoL), and medical and demographic variables.ResultsOne third (32.5%) of YACS reported participating in a sport in the past month with the most common being golf (40.8%) and ice hockey (8.3%). YACS participating in sport reported an average frequency of 1.7 (SD = 1.0) days/week and an average duration of 119 min/session (SD = 68) for a total of 189 (SD = 164) min/week. Independent t-tests showed that YACS who participated in sport reported better psychosocial health and QoL including physical QoL (p < 0.001), mental QoL (p < 0.001), self-esteem (p < 0.001), depression (p < 0.001), and stress (p < 0.001). In multivariate regression analysis, 8.5% (p < 0.001) of the variance in sport participation was explained by being male (β = 0.17, p < 0.001), Caucasian (β = 0.15, p = 0.001), in better general health (β = 0.15, p < 0.001), and having a normal body mass index (β = ?0.10, p = 0.024).Discussion/conclusionsSport participation is associated with better psychosocial health and QoL in YACS but only a third participated in the past month. Randomized controlled trials examining sport as an intervention strategy to increase physical activity and improve health outcomes in YACS are warranted.     

Maximum likelihood estimation of the joint covariance matrix for sections of tests given to distinct samples with application to test equating

Consider an old testX consisting ofs sections and two new testsY andZ similar toX consisting ofp andq sections respectively. All subjects are given testX plus two variable sections from either testY orZ. Different pairings of variable sections are given to each subsample of subjects. We present a method of estimating the covariance matrix of the combined test (X ₁, ...,X _s ,Y ₁, ...,Y _p ,Z ₁, ...,Z _q ) and describe an application of these estimation techniques to linear, observed-score, test equating.The author is indebted to Paul W. Holland and Donald B. Rubin for their encouragement and many helpful comments and suggestions that contributed significantly to the development of this paper.This research was supported by the Program Statistics Research Project of the ETS Research Statistics Group.     

"儒"的自我理解——荀子说儒的意义

No matter what the original meaning of “Ru” was, looking at it from the perspective of the history of philosophy, the image of “Ru” as portrayed by other schools in the Warring States period was infused with the characteristics of Confucianism of that time. The self-understanding of Warring States Confucians expressed by their employment of the character “Ru” clearly displayed Ru’s character as well as the main points of the Ru school, namely Confucianism. In particular, the words and thoughts of Xunzi, the great Confucian master, on “Ru”, epitomize Pre-Qin Confucian’s understanding and expectations of themselves, and also reflect the Confucian new pursuit in facing the age of the unification of Qin. Translated by Yan Xin from Beijing daxue xuebao 北京大学学报 (Journal of Peking University), 2007, (5): 19–26     

Increased forefoot loading is associated with an increased plantar flexion moment

The aim of this study was to identify the cascade of effects leading from alterations in force generation around the ankle joint to increased plantar pressures under the forefoot. Gait analysis including plantar pressure measurement was performed at an individually preferred and a standardized, imposed gait velocity in diabetic subjects with polyneuropathy (n = 94), without polyneuropathy (n = 39) and healthy elderly (n = 19). The plantar flexion moment at 40% of the stance phase was negatively correlated with the displacement rate of center of pressure (r = ?.749, p < .001 at the imposed, and r = ?.693, p < .001 at the preferred gait velocity). Displacement rate of center of pressure was strongly correlated with forefoot loading (r = ?.837, p < .001 at the imposed, and r = ?.731, p < .001 at the preferred gait velocity). People with a relatively high plantar flexion moment at 40% of the stance phase, have a faster forward transfer of center of pressure and consequently higher loading of the forefoot. This indicates that interventions aimed at increasing the control of the roll-off of the foot may contribute to a better plantar pressure distribution.     

Kinematic patterns during walking in children: Application of principal component analysis

The relative displacements of body segments during walking can be reduced to a small number of multi-joint kinematic patterns, pm_k, through Principal Component Analysis (PCA). These patterns were extracted from two groups of children (n = 8, aged 6–9 years, 4 males, and n = 8, aged 10–13 years, 4 males) and 7 adults (21–29 years, 1 male), walking on a treadmill at various velocities, normalized to body stature (adimensional Froude number, Fr). The three-dimensional coordinates of body markers were captured by an optoelectronic system.Five components (pm₁ to pm₅) explained 99.1% of the original dataset variance. The relationship between the variance explained (“size”) of each pm_k and the Fr velocity varied across movement components and age groups. Only pm₁ and pm₂, which described kinematic patterns in the sagittal plane, showed significant differences (at p < 0.05) across pairs of age groups. The time course of the size of all the five components matched various mechanical events of the step cycle at the level of both body system and lower limb joints. Such movement components appeared clinically interpretable and lend themselves as potential markers of neural development of walking.     

命与天命:儒家天人关系的双重视角

As a pair of important categories in traditional Chinese culture, “ming 命 (destiny or decrees)” and “tian ming 天命 (heavenly ordinances)” mainly refer to the constraints placed on human beings. Both originated from “ling 令 (decrees),” which evolved from “wang ling 王令 (royal decrees)” into “tian ling 天令 (heavenly decrees),” and then became “ming” from a throne because of the decisive role of “heavenly decrees” over a throne. “Ming” and “tian ming” have different definitions: “Ming” represented the limits Heaven placed on the natural lives of human beings and was an objective force that men could not direct, but was embodied in human beings as their “destiny”; “Tian ming” reflected the moral ideals of human beings in their self-identification; It originated in man but had to be verified by Heaven, and it was therefore the true ordinance that Heaven placed on human beings. “Ming” and “tian ming” are two perspectives on the traditional relationship between Heaven and human beings, and at the same time Confucians and Daoists placed different emphasis on them. Translated by Huang Deyuan from Zhongguo zhexueshi 中国哲学史 (History of Chinese Philosophy), 2007, (4): 11–21     

Motivational characteristics of obese adolescents toward physical activity: Contribution of self-determination theory

IntroductionRegular physical activity (PA) practice represents a key component of obesity treatment.ObjectiveBased on self-determination theory (SDT), this cross-sectional study aimed to explore the motivational characteristics associated with PA practice among obese adolescents.MethodOne hundred and five overweight or obese adolescents (mean age = 15 years old, SD = 2.69) were questioned about their level of PA, motivational regulations toward PA and level of satisfaction of basic psychological needs.ResultsData revealed that satisfaction of autonomy and relatedness needs is positively associated with autonomous forms of motivation (e.g., for integrated regulation β = .44; and 0.35, respectively, p < .01). Otherwise, non-satisfaction of the needs of autonomy and competence is associated with the most controlled forms of motivation (e.g., for external regulation β = −.27, p < .01; and −.18, p < .05, respectively). In turn, a high level of identified regulation, a low level of external regulation and a high level of satisfaction of the need for competence are associated with weekly PA (β = .28; −.19 and .24, respectively, p < .05).ConclusionSDT appears as an interesting theoretical framework to explore motivational antecedents of PA among obese adolescents.     

Two years of physically active mathematics lessons enhance cognitive function and gross motor skills in primary school children

Physically active lessons have been shown to enhance academic achievement. However, the effects on cognitive function and gross motor skill development remain unknown. The present study examined how the incorporation of physical activity bouts within Mathematics lessons affects cognitive function and gross motor skill development across 2 years in primary school children. Eighty-two children (6.6 ± 0.3 y) were allocated to an intervention (n = 36; completing 8 h/wk of physically active lessons) or control (n = 46) group. A battery of cognitive function tests was completed, alongside the TGMD-3 to assess gross motor skills. Physically active Mathematics lessons led to greater improvements across all measures of cognition, when compared to the control group (digit span forwards, p < 0.001, d = 1.5; digit span backwards, p = 0.017, d = 1.0; free word recall: p < 0.001, d = 1.3; selective visual attention: p < 0.001, d = 0.3; verbal fluency: p < 0.001, d = 0.9; arithmetic: p < 0.001, d = 1.8). Furthermore, the intervention group demonstrated greater improvements in overall score on the TGMD-3 (p < 0.001, d = 1.7), as well as the locomotion (p < 0.001, d = 1.1) and object control (p < 0.001, d = 1.5) sub-scales. The physically active Mathematics lessons intervention appears to offer synergistic benefits in relation to cognitive and motor development, which are critical for optimal development in the early years.     

Cyborg intentionality: Rethinking the phenomenology of human–technology relations

This article investigates the types of intentionality involved in human–technology relations. It aims to augment Don Ihde’s analysis of the relations between human beings and technological artifacts, by analyzing a number of concrete examples at the limits of Ihde’s analysis. The article distinguishes and analyzes three types of “cyborg intentionality,” which all involve specific blends of the human and the technological. Technologically mediated intentionality occurs when human intentionality takes place “through” technological artifacts; hybrid intentionality occurs when the technological actually merges with the human; and composite intentionality is the addition of human intentionality and the intentionality of technological artifacts.

The tragedy of a comic: fundamentalists crusading against fundamentalists

Christian Fundamentalists used to read the apocalyptic scenario through the “red” filter of communism, but since the 1980s the target has shifted to the “green tide” of Islam. One of the more colorful Fundamentalist diatribes against Islam is cartoon evangelist Jack Chick’s The Prophet, a comic book that calls Islam a Satanic plot hatched by the Catholic church. This article examines the rhetoric of Christian Fundamentalist diatribe against Islam in light of apocalyptic scenarios drawn out of biblical prophecy. Chick’s comic and the millenarian Hal Lindsay’s The Late Great Planet Earth are placed in the context of doctrinal attacks on Islam in medieval Christendom. In tracing the usage of “Islamic fundamentalism,” I argue that the term “fundamentalism” is problematic for cross-cultural studies of religious expression and movements.

Making global news: “Freedom of speech” and “Muslim rage” in U.S. journalism

The American press began to take notice of the Danish cartoons after they began to circulate outside of Europe. The press primarily framed the events as a single problem of global interaction: an issue of ‘freedom of speech’ opposed to ‘religious sensitivity.’ Much of the coverage permitted, within limits, a plurality of voices. Drawing on a case study of stories about the ‘cartoon controversy’ in the Boston Globe, I argue that U.S. journalism is organized by a logic of objectivity that seeks to produce a ‘perspectiveless perspective on all perspectives’ (Bourdieu, On television. New York: The New Press, 1998), showing voices on ‘both sides,’ simultaneously masked and contributed to the press’s reifying a series of events into a single global ‘event,’ one that reflected a clash of Western and Islamic values.

The mental representation of causal conditional reasoning: mental models or causal models

In this paper, two experiments are reported investigating the nature of the cognitive representations underlying causal conditional reasoning performance. The predictions of causal and logical interpretations of the conditional diverge sharply when inferences involving pairs of conditionals—such as if P₁then Q and if P₂then Q—are considered. From a causal perspective, the causal direction of these conditionals is critical: are the P_icauses of Q; or symptoms caused byQ. The rich variety of inference patterns can naturally be modelled by Bayesian networks. A pair of causal conditionals where Q is an effect corresponds to a “collider” structure where the two causes (P_i) converge on a common effect. In contrast, a pair of causal conditionals where Q is a cause corresponds to a network where two effects (P_i) diverge from a common cause. Very different predictions are made by fully explicit or initial mental models interpretations. These predictions were tested in two experiments, each of which yielded data most consistent with causal model theory, rather than with mental models.     

An axiomatization of the ratio/difference representation

If ≥_r and ≥_d are two quaternary relations on an arbitrary set A, a ratio/difference representation for ≥_r and ≥_d is defined to be a function f that represents ≥_r as an ordering of numerical ratios and ≥_d as an ordering of numerical differences. Krantz, Luce, Suppes and Tversky (1971, Foundations of Measurement. New York, Academic Press) proposed an axiomatization of the ratio/difference representation, but their axiomatization contains an error. After describing a counterexample to their axiomatization, Theorem 1 of the present article shows that it actually implies a weaker result: if ≥_r and ≥_d are two quaternary retations satisfying the axiomatization proposed by Krantz et al. (1971), and if ≥_r′ and ≥_d′ are the relations that are inverse to ≥_r and ≥_d, respectively, then either there exists a ratio/difference representation for ≥_r and ≥_d, or there exists a ratio/difference representation for ≥_r′ and ≥_d′, but not both. Theorem 2 identifies a new condition which, when added to the axioms of Krantz et al. (1971), yields the existence of a ratio/difference representation for relations ≥_r and ≥_d.     

Sick? Or slow? On the origins of intelligence as a psychological object

This paper examines the first moments of the emergence of “psychometrics” as a discipline, using a history of the Binet–Simon test (precursor to the Stanford–Binet) to engage the question of how intelligence became a “psychological object.” To begin to answer this, we used a previously-unexamined set of French texts to highlight the negotiations and collaborations that led Alfred Binet (1857–1911) to identify “mental testing” as a research area worth pursuing. This included a long-standing rivalry with Désiré-Magloire Bourneville (1840–1909), who argued for decades that psychiatrists ought to be the professional arbiters of which children would be removed from the standard curriculum and referred to special education classes in asylums. In contrast, Binet sought to keep children in schools and conceived of a way for psychologists to do this. Supported by the Société libre de l'étude psychologique de l'enfant [Free society for the psychological study of the child], and by a number of collaborators and friends, he thus undertook to create a “metric” scale of intelligence—and the associated testing apparatus—to legitimize the role of psychologists in a to-that-point psychiatric domain: identifying and treating “the abnormal”. The result was a change in the earlier law requiring all healthy French children to attend school, between the ages of 6 and 13, to recognize instead that otherwise normal children sometimes need special help: they are “slow” (arriéré), but not “sick.” This conceptualization of intelligence was then carried forward, through the test's influence on Lewis Terman (1877–1956) and Lightner Witmer (1867–1956), to shape virtually all subsequent thinking about intelligence testing and its role in society.