Miracle-dz/UniFAR-FTUs huggingface dataset:
THE ROLE AND FUNCTION OF PROOF WITH SKETCHPAD*

THE ROLE AND FUNCTION OF PROOF WITH SKETCHPAD* Michael de Villiers, University of Durban-Westville Introduction The problems that students have with perceiving a need for proof is wellknown to all high school teachers and is identified without exception in all educational research as a major problem in the teaching of proof. Who has not yet experienced frustration when confronted by students asking "why do we have to prove this? " The following conclusion by Gonobolin (1954:61) exemplifies the problem: ". the pupils . do not . recognize the necessity of the logical proof of geometric theorems, especially when these proofs are of a visually obvious character or can easily be established empirically. " According to Afanasjewa in Freudenthal (1958:29) students' problems with proof should not simply be attributed to slow cognitive development (for example, an inability to reason logically), but also that students may not see the function (meaning, purpose and usefulness) of proof. In fact, several recent studies in opposition to Piaget have shown that very young children are quite capable of logical reasoning in situations that are real and meaningful to them (Wason & Johnson-Laird, 1972; Wallington, 1974; Hewson, 1977; Donaldson, 1979). Furthermore, attempts by researchers to teach logic to students have frequently provided no statistically significant differences in students’ performance and appreciation of proof (Deer, 1969; Walter, 1972; Mueller, 1975). More than anything else, it seems that the fundamental issue at hand is the appropriate motivation of the various functions of proof to students. The question is, however, "what functions does proof have within mathematics itself which can potentially be utilized in the mathematics classroom to
Federal Reserve Bank of New York Staff Reports Monetary Policy Analysis with Potentially Misspecified Models

Policy analysis with potentially misspecified dynamic stochastic general equilibrium (DSGE) models faces two challenges: estimation of parameters that are relevant for policy trade-offs and treatment of estimated deviations from the cross-equation restrictions. This paper develops and explores policy analysis approaches that are based on either the generalized shock structure for the DSGE model or the explicit modeling of deviations from cross-equation restrictions. Using post-1982 U.S. data, we first quantify the degree of misspecification in a state-of-the art DSGE model and then document the performance of different interest rate feedback rules. We find that many of the policy prescriptions derived from the benchmark DSGE model are robust to the various treatments of misspecifications considered in this paper, but that quantitatively the cost of deviating from such prescriptions varies substantially.
Visual Fixation as Equilibrium: Evidence from Superior Colliculus Inactivation

During visual fixation, the image of an object is maintained within the fovea. Previous studies have shown that such maintenance involves the deep superior colliculus (dSC). However, the mechanisms by which the dSC supports visual fixation remain controversial. According to one view, activity in the rostral dSC maintains gaze direction by preventing neurons in the caudal dSC from issuing saccade commands. An alternative hypothesis proposes that gaze direction is achieved through equilibrium of target position signals originating from the two dSCs. Here, we show in monkeys that artificially reducing activity in the rostral half of one dSC results in a biased estimate of target position during fixation, consistent with the second hypothesis, rather than an inability to maintain gaze fixation as predicted by the first hypothesis. After injection of muscimol at rostral sites in the dSC, fixation became more stable since microsaccade rate was reduced rather than increased. Moreover, the scatter of eye positions was offset relative to preinactivation baselines. The magnitude and the direction of the offsets depended on both the target size and the injected site in the collicular map. Other oculomotor parameters, such as the accuracy of saccades to peripheral targets and the amplitude and velocity of fixational saccades, were largely unaffected. These results suggest that the rostral half of the dSC supports visual fixation through a distributed representation of behaviorally relevant target position signals. The inactivation-induced fixation offset establishes the foveal visual stimulation that is required to restore the balance of activity between the two dSCs.
Complexity of resistance mechanisms to imipenem in intensive care unit strains of Pseudomonas aeruginosa.

BACKGROUND Pseudomonas aeruginosa can become resistant to carbapenems by both intrinsic (mutation-driven) and transferable (β-lactamase-based) mechanisms. Knowledge of the prevalence of these various mechanisms is important in intensive care units (ICUs) in order to define optimal prevention and therapeutic strategies. METHODS A total of 109 imipenem-non-susceptible (MIC >4 mg/L) strains of P. aeruginosa were collected in June 2010 from the ICUs of 26 French public hospitals. Their resistance mechanisms were characterized by phenotypic, enzymatic, western blotting and molecular methods. RESULTS Single or associated imipenem resistance mechanisms were identified among the 109 strains. Seven isolates (6.4%) were found to produce a metallo-β-lactamase (one VIM-1, four VIM-2, one VIM-4 and one IMP-29). Porin OprD was lost in 94 (86.2%) strains as a result of mutations or gene disruption by various insertion sequences (ISPa1635, ISPa1328, IS911, ISPs1, IS51, IS222 and ISPa41). Thirteen other strains were shown to be regulatory mutants in which down-regulation of oprD was coupled with overexpressed efflux pumps CzcCBA (n = 1), MexXY (n = 9) and MexEF-OprN (n = 3). The lack of OprD was due to disruption of the oprD promoter by ISPsy2 in one strain and alteration of the porin signal sequence in another. CONCLUSIONS Imipenem resistance in ICU P. aeruginosa strains may result from multiple mechanisms involving metallo-β-lactamase gene acquisition and genetic events (mutations and ISs) inactivating oprD, turning down its expression while increasing efflux activities or preventing insertion of porin OprD in the outer membrane. This diversity of mechanisms allows P. aeruginosa, more than any other nosocomial pathogen, to rapidly adapt to carbapenems in ICUs.
Exploring the link between reading fiction and empathy: Ruling out individual differences and examining outcomes

Abstract Readers of fiction tend to have better abilities of empathy and theory of mind (Mar et al., Journal of Personality 74: 1047–1078, 2006). We present a study designed to replicate this finding, rule out one possible explanation, and extend the assessment of social outcomes. In order to rule out the role of personality, we first identified Openness as the most consistent correlate. This trait was then statistically controlled for, along with two other important individual differences: the tendency to be drawn into stories and gender. Even after accounting for these variables, fiction exposure still predicted performance on an empathy task. Extending these results, we also found that exposure to fiction was positively correlated with social support. Exposure to nonfiction, in contrast, was associated with loneliness, and negatively related to social support.
Adaptive Control of Parameter-less Population Pyramid on the Local Distribution of Inferior Individuals

Many evolutionary techniques such as genetic algorithms (GAs) employ parameters that facilitate user control of search dynamics. However, these parameters require time-consuming tuning processes to avoid problems such as premature convergence. Unlike many GAs, the Parameter-less Population Pyramid (P3) is an optimization model that avoids premature convergence due to the pyramid-like structure of populations, and thus P3 can be applied to a wide range of problems without parameter tuning. P3 approaches to search would be useful for constructing a novel theory for optimal search using GAs. In this study, we propose a novel technique "analysis based on the Distribution of Inferior Individuals in the local neighborhood" (DII analysis). DII analysis can be applied to local search techniques, including P3. The computational complexity of applied problems can be estimated based on a number of local optima according to the results obtained using DII. We also propose combining P3 with DII analysis (P3-DII), which controls the maximum number of fitness evaluations performed by genetic operators. The computational experiments were carried out taking several combinational problems as examples. According to our experimental results, we demonstrated that P3-DII found several optimal solutions that P3 failed to find.
Near-Infrared Faint Galaxies in the Subaru Deep Field: Comparing the Theory with Observations for Galaxy Counts, Colors, and Size Distributions to K ~ 24.5

Galaxy counts in the K band, (J-K) colors, and apparent size distributions of faint galaxies in the Subaru Deep Field (SDF) down to K ~ 24.5 were studied in detail. Special attention has been paid to take into account various selection effects, including the cosmological dimming of surface brightness, to avoid any systematic bias that may be the origin of controversy in previously published results. We also tried to be very careful about systematic model uncertainties; we present a comprehensive survey of these systematic uncertainties and dependence on various parameters, and we have shown that the dominant factors to determine galaxy counts in this band are cosmology and number evolution. We found that the pure luminosity evolution (PLE) model is very consistent with all the SDF data down to K ~ 22.5, without any evidence for number or size evolution in a low-density, Λ-dominated flat universe, which is now favored by various cosmological observations. On the other hand, a number evolution of galaxies with η ~ 2, when invoked as the luminosity conserving mergers as ϕ* ∝ (1 + z)η and L* ∝ (1 + z)-η for all types of galaxies, is necessary to explain the data in the Einstein-de Sitter universe. If the popular Λ-dominated universe is taken for granted, our result then gives a strong constraint on the number evolution of giant elliptical or early-type galaxies to z ~ 1-2 that must be met by any models in the hierarchically clustering universe, since such galaxies are the dominant population in this magnitude range (K ≲ 22.5). A number evolution with η ~ 1 is already difficult to reconcile with the data in this universe. On the other hand, number evolution of late-type galaxies and/or dwarf galaxies, which has been suggested by previous studies of optical galaxies, is allowed from the data. In the fainter magnitude range of K ≳ 22.5, we found a slight excess of observed counts over the prediction of the PLE model when elliptical galaxies are treated as a single population. We suggest that this discrepancy reflects some number evolution of dwarf galaxies and/or the distinct populations of giant and dwarf elliptical galaxies which have been known for local elliptical galaxies.
Using position, fonts and cited references to retrieve scientific documents

As more and more documents become available on the internet, finding documents that fit users' needs from databases containing millions of documents is becoming increasingly important. Since a scientific document is a structured text, it has some useful features that can be used to improve retrieval performance. In this work, we investigate three such features: fonts, position and cited references. While past research has used these three features individually to improve document searching, no existing research discusses how to integrate these three together to improve retrieval performance. This work first investigates the relationships among them, and then uses these three features to design a novel retrieval method based on the discovered relationships. Extensive experiments have been carried out with real scientific documents to show its effectiveness. Our empirical results show that using the location factor alone achieves the same performance as considering location and font factors simultaneously. We also observed that citation similarity is useful only when the similarity is high. Based on these two clues, we developed a method to combine the content vector and reference vector conditionally, and as a result, this integrated approach does, indeed, improve search performance.
Artificial Adaptive Agents Affect , Anticipation , and Adaptation : Affect-Controlled Selection of Anticipatory Simulation in

Emotion plays an important role in thinking. In this article we study affective control of the amount of simulated anticipatory behavior in adaptive agents using a computational model. Our approach is based on model-based reinforcement learning (RL) and inspired by the simulation hypothesis (Cotterill, 2001; Hesslow, 2002). The simulation hypothesis states that thinking is internal simulation of behavior using the same sensory-motor systems as those used for overt behavior. Here, we study the adaptive-ness of an artificial agent, when action-selection bias is induced by an affect-controlled amount of simulated anticipatory behavior. To this end, we introduce an affect-controlled simulation-selection mechanism that uses the predictions of the agent's RL model to select anticipatory behaviors for simulation. Based on experiments with adaptive agents in two nondeterministic partially observable grid-worlds we conclude that (1) internal simulation has an adaptive benefit and (2) affective control can reduce the amount of simulation needed for this benefit. This is specifically the case if the following relation holds: positive affect decreases the amount of simulation towards simulating the best potential next action, while negative affect increases the amount of simulation towards simulating all potential next actions. In essence we use artificial affect to control mental exploration versus exploitations. Thus, agents " feeling positive " can think ahead in a narrow sense and free up working memory resources, while agents " feeling negative " must think ahead in a broad sense and maximize usage of working memory. Our results are consistent with several psychological findings on the relation between affect and learning, and contribute to answering the question of when positive versus negative affect is useful during adaptation.
Inverse Agonism of SQ 29,548 and Ramatroban on Thromboxane A2 Receptor

G protein-coupled receptors (GPCRs) show some level of basal activity even in the absence of an agonist, a phenomenon referred to as constitutive activity. Such constitutive activity in GPCRs is known to have important pathophysiological roles in human disease. The thromboxane A2 receptor (TP) is a GPCR that promotes thrombosis in response to binding of the prostanoid, thromboxane A2. TP dysfunction is widely implicated in pathophysiological conditions such as bleeding disorders, hypertension and cardiovascular disease. Recently, we reported the characterization of a few constitutively active mutants (CAMs) in TP, including a genetic variant A160T. Using these CAMs as reporters, we now test the inverse agonist properties of known antagonists of TP, SQ 29,548, Ramatroban, L-670596 and Diclofenac, in HEK293T cells. Interestingly, SQ 29,548 reduced the basal activity of both, WT-TP and the CAMs while Ramatroban was able to reduce the basal activity of only the CAMs. Diclofenac and L-670596 showed no statistically significant reduction in basal activity of WT-TP or CAMs. To investigate the role of these compounds on human platelet function, we tested their effects on human megakaryocyte based system for platelet activation. Both SQ 29,548 and Ramatroban reduced the platelet hyperactivity of the A160T genetic variant. Taken together, our results suggest that SQ 29,548 and Ramatroban are inverse agonists for TP, whereas, L-670596 and Diclofenac are neutral antagonists. Our findings have important therapeutic applications in the treatment of TP mediated pathophysiological conditions.
A randomized crossover study of bee sting therapy for multiple sclerosis

Background: Bee sting therapy is increasingly used to treat patients with multiple sclerosis (MS) in the belief that it can stabilize or ameliorate the disease. However, there are no clinical studies to justify its use. Methods: In a randomized, crossover study, we assigned 26 patients with relapsing-remitting or relapsing secondary progressive MS to 24 weeks of medically supervised bee sting therapy or 24 weeks of no treatment. Live bees (up to a maximum of 20) were used to administer bee venom three times per week. The primary outcome was the cumulative number of new gadolinium-enhancing lesions on T1-weighted MRI of the brain. Secondary outcomes were lesion load on T2*-weighted MRI, relapse rate, disability (Expanded Disability Status Scale, Multiple Sclerosis Functional Composite, Guy’s Neurologic Disability Scale), fatigue (Abbreviated Fatigue Questionnaire, Fatigue Impact Scale), and health-related quality of life (Medical Outcomes Study 36-Item Short Form General Health Survey). Results: During bee sting therapy, there was no significant reduction in the cumulative number of new gadolinium-enhancing lesions. The T2*-weighted lesion load further progressed, and there was no significant reduction in relapse rate. There was no improvement of disability, fatigue, and quality of life. Bee sting therapy was well tolerated, and there were no serious adverse events. Conclusions: In this trial, treatment with bee venom in patients with relapsing multiple sclerosis did not reduce disease activity, disability, or fatigue and did not improve quality of life.
Determinants of European Bank CDS spreads in times of crisis

Since the beginning of the financial crisis, the credit default swap (CDS) spreads of the European banks have severely increased. This paper empirically analyzes the determinants of CDS spreads of a sample of 45 European banks over the 2004-2010 period. We use variables related to accounting- and market-based data, an indicator of liquidity in the CDS market and several proxy variables for the macroeconomic environment in which these financial institutions operate. These variables were also analyzed during the pre-crisis period (2004-2006) and the crisis period (2007-2010). The primary conclusions are that the market variables and the variable that captures contract liquidity have the greatest explanatory power, whereas the accounting and macroeconomic variables included in our regression do not seem to play a significant role. Additionally, we find that the explanatory power of the model is considerably higher during the crisis period than during the pre-crisis period. This finding could be explained by a lower sensitivity of CDS spreads during periods of economic stability
Attentional Processing in C57BL/6J Mice Exposed to Developmental Vitamin D Deficiency

Epidemiological evidence suggests that Developmental Vitamin D (DVD) deficiency is associated with an increased risk of schizophrenia. DVD deficiency in mice is associated with altered behaviour, however there has been no detailed investigation of cognitive behaviours in DVD-deficient mice. The aim of this study was to determine the effect of DVD deficiency on a range of cognitive tasks assessing attentional processing in C57BL/6J mice. DVD deficiency was established by feeding female C57BL/6J mice a vitamin D-deficient diet from four weeks of age. After six weeks on the diet, vitamin D-deficient and control females were mated with vitamin D-normal males and upon birth of the pups, all dams were returned to a diet containing vitamin D. The adult offspring were tested on a range of cognitive behavioural tests, including the five-choice serial reaction task (5C-SRT) and five-choice continuous performance test (5C-CPT), as well as latent inhibition using a fear conditioning paradigm. DVD deficiency was not associated with altered attentional performance on the 5C-SRT. In the 5C-CPT DVD-deficient male mice exhibited an impairment in inhibiting repetitive responses by making more perseverative responses, with no changes in premature or false alarm responding. DVD deficiency did not affect the acquisition or retention of cued fear conditioning, nor did it affect the expression of latent inhibition using a fear conditioning paradigm. DVD-deficient mice exhibited no major impairments in any of the cognitive domains tested. However, impairments in perseverative responding in DVD-deficient mice may indicate that these animals have specific alterations in systems governing compulsive or reward-seeking behaviour.
Proteolytic systems and AMP-activated protein kinase are critical targets of acute myeloid leukemia therapeutic approaches

The therapeutic strategies against acute myeloid leukemia (AML) have hardly been modified over four decades. Although resulting in a favorable outcome in young patients, older individuals, the most affected population, do not respond adequately to therapy. Intriguingly, the mechanisms responsible for AML cells chemoresistance/susceptibility are still elusive. Mounting evidence has shed light on the relevance of proteolytic systems (autophagy and ubiquitin-proteasome system, UPS), as well as the AMPK pathway, in AML biology and treatment, but their exact role is still controversial. Herein, two AML cell lines (HL-60 and KG-1) were exposed to conventional chemotherapeutic agents (cytarabine and/or doxorubicin) to assess the relevance of autophagy and UPS on AML cells’ response to antileukemia drugs. Our results clearly showed that the antileukemia agents target both proteolytic systems and the AMPK pathway. Doxorubicin enhanced UPS activity while drugs’ combination blocked autophagy specifically on HL-60 cells. In contrast, KG-1 cells responded in a more subtle manner to the drugs tested consistent with the higher UPS activity of these cells. In addition, the data demonstrates that autophagy may play a protective role depending on AML subtype. Specific modulators of autophagy and UPS are, therefore, promising targets for combining with standard therapeutic interventions in some AML subtypes.
Formal specification languages in knowledge and software engineering

Abstract During the last few years, a number of formal specification languages for knowledge-based systems (KBS) have been developed. Characteristics of such systems are a complex knowledge base and an inference engine which uses this knowledge to solve a given problem. Languages for KBS have to cover both these aspects. They have to provide a means to specify a complex and large amount of knowledge and they have to provide a means to specify the dynamic reasoning behaviour of a KBS. Nevertheless, KBS are just a specific type of software system. Therefore, it seems quite natural to compare formal languages for specifying KBS with formal languages which were developed by the software community for specifying software systems. That is the subject of this paper.