Miracle-dz/UniFAR-FTUs huggingface dataset:
Celestial mechanics, conformal structures, and gravitational waves.

Newton's equations for the motion of $N$ nonrelativistic point particles attracting according to the inverse square law may be cast in the form of equations for null geodesics in a ($3N+2$)-dimensional Lorentzian spacetime which is Ricci flat and admits a covariantly constant null vector. Such a spacetime admits a Bargmann structure and corresponds physically to a plane-fronted gravitational wave (generalized pp wave). Bargmann electromagnetism in five dimensions actually comprises the two distinct Galilean electromagnetic theories pointed out by Le Bellac and L\'evy-Leblond. At the quantum level, the $N$-body Schr\"odinger equation may be cast into the form of a massless wave equation. We exploit the conformal symmetries of such spacetimes to discuss some properties of the Newtonian $N$-body problem, in particular, (i) homographic solutions, (ii) the virial theorem, (iii) Kepler's third law, (iv) the Lagrange-Laplace-Runge-Lenz vector arising from three conformal Killing two-tensors, and (v) the motion under time-dependent inverse-square-law forces whose strength varies inversely as time in a manner originally envisaged by Dirac in his theory of a time-dependent gravitational constant $G(t)$. It is found that the problem can be reduced to one with time-independent inverse-square-law forces for a rescaled position vector and a new time variable. This transformation (Vinti and Lynden-Bell) is shown to arise from a particular conformal transformation of spacetime which preserves the Ricci-flat condition originally pointed out by Brinkmann. We also point out (vi) a Ricci-flat metric representing a system of $N$ nonrelativistic gravitational dyons. Our results for a general time-dependent $G(t)$ are also applicable by suitable reinterpretation to the motion of point particles in an expanding universe. Finally we extend these results to the quantum regime.
How Contemporary History is Presented in Chilean Middle School Textbooks

This article provides a textual analysis of the pedagogical discourse of history textbooks used in the education of Chilean students. In particular, I focus on how the impact of Salvador Allende's socialist government (1970-1973) and the military coup that led to the Augusto Pinochet's dictatorship (1973-1990) are constructed by and displayed in these texts. As a method of analysis, I apply the Systemic Functional Grammar theory to history textbooks used in the sixth and eighth grades. Two of the metafunctions proposed by Halliday - textual and interpersonal - are particularly relevant when combined with an appraisal analysis fundamentally based on the work of Martin because they provide a useful tool for interpreting and explaining the text from an ideological standpoint. The analysis reveals that the textbooks' authors strive to sound objective, but instead offer a large number of explicit and implicit judgements throughout the text. They purport to present two antithetical political positions - that of Allende's supporters and that of the supporters of the military coup - however, the texts do not actually offer two clear positions nor do they provide clear reasons for the events. Instead, the authors obscure content through grammatical and lexical choices - such as the use of `and' as an expression of reason or cause; embedded mental and verbal projection (sixth grade only); the absence of logico-semantic relationship of elaboration; and modal adjuncts that signal judgement but not explanation. Appraisal analysis in conjunction with a more discrete grammatical analysis is useful for revealing the explicit, subjective choices made in constructing these supposedly objective texts.
Evaluation of testicular toxicology: a synopsis and discussion of the recommendations proposed by the Society of Toxicologic Pathology.

BACKGROUND Detection of chemically induced effects on male fertility and on testicular spermatogenesis in particular, has become of increasing concern. More stringent regulatory guidelines, introduced by ICH, EPA and OECD (Table 1) have raised the awareness of toxicologists and pathologists for the need to conduct sensitive and careful evaluation of the male reproductive tract for potential toxic effects of administered compounds. With it has come confusion and in many cases, inappropriate procedures, often based on misunderstanding of what is required and on inadequate understanding of spermatogenesis. This article summarizes and discusses the main recommendations recently proposed by the Society of Toxicologic Pathology on recommended approaches for the evaluation of testicular and epididymal toxicity [Lanning LL, Creasy DM, Chapin RE, Mann PC, Barlow NJ, Regan KS, Goodman DG. Toxicologic Pathology 30:518-531, 2002]. The major recommendations are: Use sexually mature animals to evaluate effects on spermatogenesis. Sample left and right testes and epididymides and record organ weights. Use modified Davidson's fixative to fix testes from all species from studies of 13 wks duration and less. Examine transverse sections of the testes (including part of the rete), and longitudinal sections of the epididymides. Embed tissues in paraffin wax. For rodent studies up to 28 days, examine periodic acid-Schiff's-hematoxylin stained sections. For all other studies examine hematoxylin and eosin stained sections. Microscopic evaluation of the testis should be a qualitative evaluation carried out with an awareness of the spermatogenic cycle. Quantitative procedures are inappropriate for screening studies. Nomenclature and grading of findings for spermatogenic disturbances will vary on a case by case basis.
Hippocampal modulation of locomotor activity induced by focal activation of postsynaptic dopamine receptors in the core of the nucleus accumbens

The locomotor effects of intra‐NAcc injection of dopamine receptor agonists following discrete lesion or inhibition of the DH or the VH have been poorly investigated using only the indirect dopamine receptor agonist amphetamine. In the present study, we investigated how lidocaine in the DH or the VH modulated hyperlocomotion induced by focal injection into the NAcc core of the selective D1‐like receptor agonist, SKF 38393, or coinjection of SKF 38393, and the selective D2‐like receptor agonist, LY 171555; the latter pharmacological condition being required for the full expression of the postsynaptic effects of D2‐like receptor agonists, and recognized to produce a locomotor response mainly mediated by D2‐like postsynaptic receptors. Rats were given the D1‐like receptor agonist SKF 38393 alone or in combination with the D2‐like receptor agonist LY 171555 into the NAcc core, and lidocaine into the DH or the VH. Then, locomotor activity was recorded. Focal injection into the NAcc core of SKF 38393 alone or in combination with LY 171555 resulted in an increase of locomotor activity. Administration of lidocaine into the DH further potentiated the increase in locomotor activity induced by activation of D1‐like receptors or co‐activation of D1‐like and D2‐like receptors in the NAcc core. Administration of lidocaine into the VH also potentiated the increase in locomotor activity induced by D1‐like receptor activation, but decreased that produced by co‐activation of D1‐like and D2‐like receptors in the NAcc core. Taken together, these results suggest that under lidocaine‐free conditions the DH may exert a tonic inhibitory modulation on hyperlocomotion mediated by D1‐like and D2‐like postsynaptic receptors in the NAcc core, while the VH may exert a tonic inhibitory on hyperlocomotion mediated by D1‐like receptors and a tonic facilitatory control on hyperlocomotion mediated by D2‐like postsynaptic receptors. © 2007 Wiley‐Liss, Inc.
A fuzzy guided genetic algorithm for operon prediction

MOTIVATION The operon structure of the prokaryotic genome is a critical input for the reconstruction of regulatory networks at the whole genome level. As experimental methods for the detection of operons are difficult and time-consuming, efforts are being put into developing computational methods that can use available biological information to predict operons. METHOD A genetic algorithm is developed to evolve a starting population of putative operon maps of the genome into progressively better predictions. Fuzzy scoring functions based on multiple criteria are used for assessing the 'fitness' of the newly evolved operon maps and guiding their evolution. RESULTS The algorithm organizes the whole genome into operons. The fuzzy guided genetic algorithm-based approach makes it possible to use diverse biological information like genome sequence data, functional annotations and conservation across multiple genomes, to guide the organization process. This approach does not require any prior training with experimental operons. The predictions from this algorithm for Escherchia coli K12 and Bacillus subtilis are evaluated against experimentally discovered operons for these organisms. The accuracy of the method is evaluated using an ROC (receiver operating characteristic) analysis. The area under the ROC curve is around 0.9, which indicates excellent accuracy. CONTACT roschen_csir@rediffmail.com.
Endogenous porphyrin fluorescence in tumors

The fluorescence of endogenous porphyrins in tumors has been attributed to the presence of several different species of bacteria inhabiting ulcerated and necrotic tissues. We have examined this “autofluorescence” in carcinogen‐induced tumors in the hamster oral mucosa and in patients with cancer of the oral cavity. In several instances, bright autofluorescence of normal tissues has been observed. This represents a potential false‐positive identification of cancer when systemic hematoporphyrin derivative fluorescence is used as a diagnostic technique.
The Role of Underlining and Annotating in Remembering Textual Information.

Abstract The purpose of this study was to explore opposing theoretical viewpoints as they relate to and attempt to explain the effects of text underlining. The subjects were 67 provisionally admitted freshmen who were randomly assigned to one of four experimenter‐generated underlining or underlining and annotating conditions, or a fifth group who generated their own text marking. During two sessions, all subjects took a test of prior knowledge, read the assigned passage, and took a 24 item multiple‐choice test consisting of 12 high relevant and 12 low relevant questions. Data analysis supported the von Restorff effect as a theoretical explanation of text underlining since subjects in the high relevant groups answered more high relevant items correctly, while subjects in the low relevant groups answered more low relevant items correctly. Subjects who generated their own underlining did not perform significantly better than those who were given experimenter‐generated marking. Additionally, prior knowledge w.
Investigation of threat-related attentional bias in anxious children using the startle eyeblink modification paradigm

We used the startle eyeblink modification paradigm to investigate whether clinically anxious children, like high trait-anxious adults, display a bias in favour of threat words compared to neutral words. The present study included 16 clinically anxious children whose diagnostic status was determined using the parent version of a semistructured diagnostic interview as part of a larger childhood anxiety study. The children were presented with threat and neutral words for 6 s each. A startle-eliciting auditory stimulus - a 100 dBA burst of white noise of 50 ms duration - was presented during the words at lead intervals of 60, 120, 240, or 3500 ms and during intertrial intervals. The overall pattern of startle eyeblink modification indicated inhibition at the 120 and 240 ms lead intervals and facilitation at the 3500 ms lead interval. Startle-latency shortening during threat words at the 60 ms lead interval was larger than at other intervals, whereas there was no difference during neutral words. This result reflects an anxiety-related bias in favour of threat words occurring at a very early - and possibly preattentive stage - of information processing.
A Biologically Based Computational Model of Working Memory

FIVE CENTRAL FEATURES OF THE MODEL We define working memory as controlled processing involving active maintenance and/or rapid learning, where controlled processing is an emergent property of the dynamic interactions of multiple brain systems, but the prefrontal cortex (PFC) and hippocampus (HCMP) are especially influential owing to their specialized processing abilities and their privileged locations within the processing hierarchy (both the PFC and HCMP are well connected with a wide range of brain areas, allowing them to influence behavior at a global level). The specific features of our model include: (1) A PFC specialized for active maintenance of internal contextual information that is dynamically updated and self-regulated, allowing it to bias (control) ongoing processing according to maintained information (e.g., goals, instructions, partial products). (2) An HCMP specialized for rapid learning of arbitrary information, which can be recalled in the service of controlled processing, whereas the posterior perceptual and motor cortex (PMC) exhibits slow, long-term learning that can efficiently represent accumulated knowledge and skills. (3) Control that emerges from interacting systems (PFC, HCMP, and PMC). (4) Dimensions that define continua of specialization in different brain systems: for example, robust active maintenance, fast versus slow learning. (5) Integration of biological and computational principles. Working memory is an intuitively appealing theoretical construct – perhaps deceptively so.
Experimental Evolution as an Underutilized Tool for Studying Beneficial Animal–Microbe Interactions

Microorganisms play a significant role in the evolution and functioning of the eukaryotes with which they interact. Much of our understanding of beneficial host–microbe interactions stems from studying already established associations; we often infer the genotypic and environmental conditions that led to the existing host–microbe relationships. However, several outstanding questions remain, including understanding how host and microbial (internal) traits, and ecological and evolutionary (external) processes, influence the origin of beneficial host–microbe associations. Experimental evolution has helped address a range of evolutionary and ecological questions across different model systems; however, it has been greatly underutilized as a tool to study beneficial host–microbe associations. In this review, we suggest ways in which experimental evolution can further our understanding of the proximate and ultimate mechanisms shaping mutualistic interactions between eukaryotic hosts and microbes. By tracking beneficial interactions under defined conditions or evolving novel associations among hosts and microbes with little prior evolutionary interaction, we can link specific genotypes to phenotypes that can be directly measured. Moreover, this approach will help address existing puzzles in beneficial symbiosis research: how symbioses evolve, how symbioses are maintained, and how both host and microbe influence their partner’s evolutionary trajectories. By bridging theoretical predictions and empirical tests, experimental evolution provides us with another approach to test hypotheses regarding the evolution of beneficial host–microbe associations.
Quadrature-Error Compensation and Corresponding Effects on the Performance of Fully Decoupled MEMS Gyroscopes

This paper presents experimental data about the sources of the quadrature error in a fully decoupled microelectromechanical systems gyroscope and demonstrates the extent of performance improvement by the cancellation of this error. Quadrature sources including mass, electrostatic-force, and mechanical-spring imbalances have been compared by FEM simulations, and spring imbalance has been found as the dominant source of the quadrature error. Gyroscopes have been designed with intentional spring imbalances and fabricated with a SOI-based silicon-on-glass fabrication process, the resulting quadrature outputs of the fabricated gyroscopes have been measured, and their agreement with FEM simulations has been verified. Next, it has been experimentally shown that the electrostatic nulling of the quadrature error with closed-loop control electronics improves the bias instability and angle random walk (ARW) of a fully decoupled gyroscope up to ten times. Moreover, the quadrature cancellation improves the scale-factor turn-on repeatability about four times and linearity about 20 times, reaching down to 119 and 86 ppm, respectively. Finally, the quadrature cancellation allows operating the gyroscope with higher drive-mode displacement amplitudes for an increased rate sensitivity. With this technique, outstanding bias instability and ARW performances of 0.39°/h and 0.014 °/√h, respectively, have been achieved.
Paronychia and pyogenic granuloma of the great toes in patients treated with indinavir.

To the Editor: Forty-two patients infected with human immunodeficiency virus type 1 (HIV-1) (38 men and 4 women) presented with paronychia of the great toes during the period from September 1996 to September 1997. The median age of the patients was 36 years (range, 22 to 64); 36 were homosexuals, 3 were intravenous-drug users, and 3 were heterosexuals with no known risk factors. Thirty-six patients had AIDS. The mean CD4 lymphocyte count was 255 per cubic millimeter (range, 16 to 892). Plasma HIV RNA was undetectable in 13 patients and ranged from 600 to 10 6 copies per milliliter in the .
A multi-stage account of binding in vision: Neuropsychological evidence

I review neuropsychological evidence on the problems patients can have in binding together the attributes of visual stimuli, following brain damage. The evidence indicates that there can be several kinds of binding deficit in patients. Damage to early visual processing within the ventral visual stream can disrupt the binding of contours into shapes, though the binding of form elements into contours can still operate. This suggests that the process of binding elements into contour is distinct from the process of binding contours into shapes. The latter form of binding seems to operate within the ventral visual system. In addition, damage to the parietal lobe can disrupt the binding of shape to surface information about objects, even when the binding of elements into contours, and contours into shapes, seems to be preserved. These findings are consistent with a multi-stage account of binding in vision, which distinguishes between the processes involved in binding shape information (in the ventral visual stream) and the processes involved in binding shape and surface detail (involving interactions between the ventral and dorsal streams). In addition, I present evidence indicating that a further, transient form of binding can take place, based on stimuli having common visual onsets. I discuss the relations between these different forms of binding.
Passivity-based synchronized visual feedback control for eye-to-hand systems

This paper investigates passivity based synchronized visual feedback control for eye-to-hand systems. Firstly the brief summary of the estimation and the control error systems is given with the basic representation of a relative rigid body motion. Secondly we construct the synchronized visual feedback system with an eye-to-hand configuration by combining a synchronization error system. Next, we derive the passivity of the synchronized visual feedback system. Based on passivity, stability analysis is discussed. Finally the validity of the proposed control law can be confirmed by the simulation results.
Socially Oriented Motivational Goals and Academic Achievement: Similarities Between Native and Anglo Americans

ABSTRACT The authors examined the relations between two socially oriented dimensions of student motivation and academic achievement of Native (Navajo) American and Anglo American students. Using confirmatory factor analysis, a multidimensional and hierarchical model was found to explain the relations between performance and social goals. Four first-order goal constructs (competition, social power, affiliation, and social concern) represented by 2 higher order factors (performance and social dimensions) were found to be invariant for two cultural groups of high school students in the United States: Navajo (n = 1,482) and Anglo (n = 803). The findings suggest that the effects of performance goals are relatively stronger, and are similarly strong cross-culturally. However, Navajo students were relatively lower in achievement scores and competition goals but higher in social concern.
Individual differences in the interpretation of ambiguous statements about time

Abstract What factors influence the ways in which people resolve ambiguity? In English, two contrasting perspectives are implicit in deictic temporal expressions: the Moving Time metaphor conceptualizes time as moving forward towards the ego and the Moving Ego metaphor conceptualizes the ego as moving forward towards the future (Clark 1973). We examine the ambiguity arising from these two conceptualizations, claimed to be equally likely in a “neutral” context (Boroditsky and Ramscar 2002). Whereas previous studies have demonstrated that exposure to a spatial situation related to one interpretation may influence the resolution of the ambiguity (e.g. Boroditsky 2000; Nunez 2007), we focus on the lifestyle and personality factors of the participants as potential additional influences on ambiguity resolution in the interpretation of temporal metaphors. Experiment 1 asks whether lifestyle might influence an individual's approach to time and resulting resolution of temporal ambiguity, comparing preferred responses from two groups of participants with very different demands on the structuring of time: university students and administrators. We observed a difference between the two groups, with administrators more frequently adopting the Moving Time perspective and students, the Moving Ego perspective. Experiment 2 examines personality-related differences, focusing specifically on individual differences in procrastination (Lay 1986) and conscientiousness (John 1990). We observed a significant effect with participants who adopted the Moving Ego perspective reporting higher procrastination scores and lower conscientiousness scores than participants who adopted the Moving Time perspective. Experiment 3 investigates further personality-related differences, focusing specifically on individual differences in extroversion (John 1990). We observed a relationship between extroversion and disambiguation responses, with participants who adopted the Moving Ego perspective evidencing higher levels of extroversion. Taken together, the results from these three studies suggest that individual differences in lifestyle and personality may influence people's perspectives on the movement of events in time and their concomitant interpretation of temporally ambiguous utterances, precluding a universal “neutral” context within which language is interpreted.