Miracle-dz/UniFAR-FTUs huggingface dataset:
Mental imagery in the navigation domain: a computational model of sensory-motor simulation mechanisms

Recent experimental evidence indicates that animals can use mental simulation to make decisions about the actions to take during goal-directed navigation. The principal brain areas found to be active during this process are the hippocampus, the ventral striatum and the sensory-motor cortex. In this paper, we present a computational model that includes biological aspects of this circuit and explains mechanistically how it may be used to imagine and evaluate future events. Its most salient characteristic is that choices about actions are made by simulating movements and their sensory effects using the same brain areas that are active during overt execution. More precisely, the simulation of an action (e.g., walking) creates a new sensory pattern that is evaluated in the same way as real inputs. The model is validated in a navigation task in which a simulated rat is placed in a complex maze. We show that hippocampal and striatal cells are activated to simulate paths, to retrieve their estimated value and to make decisions. We link these results with a general framework that sees the brain as a predictive device that can ‘detach’ itself from the here-and-now of current perception using mechanisms such as episodic memories, motor and visual imagery.
Evolutionary models for the retention of adult–adult social play in primates: The roles of diet and other factors associated with resource acquisition

What factors in animal life history facilitate or reduce the probability that a species will perform play behavior? While some relationships are known within species and across individuals, it is not obvious that such relationships can be used to explain differences and similarities in amount and type of play across large taxonomic groupings of animals, let alone transitions among them. Primates encompass a relatively large assemblage of species that differ in numerous dietary, habitat, reproductive, and physiological processes. While all juvenile primates engage in social play, far fewer primate species engage in social play as adults. Here, derived from theory and more small-scale comparisons, we explore several biological and behavioral phenomena that differ among nonhuman primates and which may explain differences in the occurrence of adult–adult social play. We used phylogenetic logistic regression to assess the correlation of adult play with various life-history, metabolic and socioecological variables. Although the main contribution of our paper is demonstrating use of phylogenetic methods in the context of play evolution, suggestive but not significant evidence was found that adult sexual and nonsexual social play is influenced by diet, habitat, reproductive, and metabolic factors, sometimes in opposite directions, that we discuss along with needed future analyses involving improved data and interactions among traits.
Machine vision and fuzzy logic-based navigation control of a goal-oriented mobile robot

This work addresses a new goal oriented navigation framework for autonomous system. In the proposed work, a hybrid control system, comprising deliberative and behavior-based architectures, has been developed. Deliberative layer employs a monocular vision camera to obtain the position of the goal while behavior-based framework makes use of the motor schema technique for safe navigation. Fuzzy logic is also adopted in order to enhance the performance of the navigation system. A rigorous series of experiments has been conducted using two navigation methods, which are the proposed control system and the conventional navigation technique utilizing the potential field method for achieving the desired goals. Both systems are implemented in the simulated experiments using Stage simulator. By employing these two approaches, it is possible to present a comparison of the navigation results between the systems utilizing different navigation techniques. The experimental results reveal that the proposed system produces better navigation performance compared to the conventional method in terms of safe and successful navigation, with a smoother trajectory and consistent motion.
Cognitive map self-organization from subjective visuomotor experiences in a hierarchical recurrent neural network

Animals develop and use cognitive maps, which are internal models of the external environment, to understand the spatial characteristics of their natural environment. Previous studies have shown that a hierarchical structure of recurrent neural networks contributes to the extraction of high-level concepts in sequential sensorimotor experiences. However, the previous studies did not focus on the spatial aspects of these experiences and did not acquire cognitive maps. We modified previous models and trained the proposed model with the visuomotor experiences of an agent in a simulated two-dimensional environment. The proposed model was trained to predict future visual and motion inputs even when only one modality was provided (crossmodal prediction). The proposed model correctly predicted visual images, even when the agent experienced unknown paths. Comparisons of the crossmodal predictions of the models under different conditions revealed that the crossmodal predictions related to motion resulted in self-organization of the cognitive map. Further experiments of mental simulation abilities showed that two-way crossmodal predictions (from vision and motion only) were required for consistent generation of vision and motion. These results indicated that predictive learning involving integrated vision and motion was necessary for self-organization of spatial recognition with a cognitive map.
Wide-sense nonblocking multicast Log2(N, m, p) networks

Recently, Tscha and Lee proposed a fixed-size window algorithm for the multicast Log/sub 2/(N,0,p) network and expressed a desire to see its extension to the Log/sub 2/(N,m,p) network. Later, Kabacinski and Danilewicz generalized the fixed-size window to variable size to improve the results. In this paper, we further extend the variable-size results from the Log/sub 2/(N,0,p) network to Log/sub 2/(N,m,p). Note that this extension is difficult since each link in the channel graph of Log/sub 2/(N,0,p) has the same blocking effect, but not so in Log/sub 2/(N,m,p). We also determine the optimal window size and optimal m.
On the ergodic capacity as a function of the correlation properties in systems with multiple transmit antennas without CSI at the transmitter

In this letter, the impact of correlation of the transmit antennas of a multiple-input single-output (MISO) system, with no channel state information (CSI) at the transmitter and perfect CSI at the receiver is analyzed. We show that the ergodic capacity for the single-user MISO system is Schur-concave with respect to the vector with eigenvalues of the channel covariance matrix, i.e., the more correlation that exists between the transmit antennas, the less is the achievable capacity. Furthermore, the capacity loss for fully correlated transmit antennas in comparison with the uncorrelated case is derived. The results for the ergodic capacity are compared with the impact of correlation on the outage probability. The relationship between correlation properties and outage probability is more complicated than the relationship between the correlation properties and the ergodic capacity. It is shown that the outage probability is Schur-convex in the high signal-to-noise ratio (SNR) regime, and Schur-concave in the low SNR regime.
Envelope-aided Viterbi receivers for GMSK signals with limiter-discriminator detection

Continuous phase modulation schemes, such as Gaussian minimum-shift keying (GMSK), are frequently used with limiter-discriminator (LD) detectors. This paper studies how the side information derived from the signal envelope can enhance the performance of a Viterbi algorithm (VA)-based receiver operating on the LD output of a GMSK scheme. By considering the joint probability density function of envelope and frequency, different approximations yield different novel metrics for VA, using the three-variables envelope and its derivative, and frequency error in different combinations. Simulation results confirm that such envelope-aided VA gives significant performance gains, and that envelope information complements the frequency information output by the LD detector in frequency-selective fading channels.
DEM-a data exchange facility for virtual enterprises

This paper presents the DEM (Data Exchange and Management) architecture, an information exchange facility for virtual enterprises based on the OMG's CORBA. This facility enables different cooperating organizations to exchange data between autonomous systems in a flexible manner. The architecture provides access to information and services across system boundaries, locations, data representations and organizations.
Joint source/channel coding and MAP decoding of arithmetic codes

In this paper, a novel maximum a posteriori (MAP) estimation approach is employed for error correction of arithmetic codes with a forbidden symbol. The system is founded on the principle of joint source channel coding, which allows one to unify the arithmetic decoding and error correction tasks into a single process, with superior performance compared to traditional separated techniques. The proposed system improves the performance in terms of error correction with respect to a separated source and channel coding approach based on convolutional codes, with the additional great advantage of allowing complete flexibility in adjusting the coding rate. The proposed MAP decoder is tested in the case of image transmission across the additive white Gaussian noise channel and compared against standard forward error correction techniques in terms of performance and complexity. Both hard and soft decoding are taken into account, and excellent results in terms of packet error rate and decoded image quality are obtained.
Calcium Supplements and Colorectal Adenomas

ABSTRACT Experimental and observational findings suggest that calcium intake may protect against colorectal neoplasia. To investigate this hypothesis, we conducted a randomized, double‐blind trial of colorectal adenoma recurrence. Nine hundred thirty patients with a recent history of colorectal adenomas were randomly given calcium carbonate (3 gm daily; 1200 mg elemental calcium) or placebo, with follow‐up colonoscopies one and four years after the qualifying examination. The main analysis focused on new adenomas found after the first follow‐up endoscopy, up to (and including) the second follow‐up examination. Risk ratios of at least one recurrent adenoma and ratios of the average numbers of adenomas were calculated as measures of calcium effect. There was a lower risk of recurrent adenomas in subjects assigned calcium. Eight hundred thirty‐two patients had two follow‐up examinations and were included in the main analysis; the adjusted risk ratio of one or more adenomas was 0.81 (95% CI 0.67 to 0.99); the adjusted ratio of the average numbers of adenomas was 0.76 (95% CI 0.60 to 0.96). Among subjects who had at least one follow‐up colonoscopy, the adjusted risk ratio of one or more recurrent adenomas was 0.85 (95% CI 0.74 to 0.98). The effect of calcium seemed independent of initial dietary fat and calcium intake. No toxicity was associated with supplementation. These findings indicate that calcium supplementation has a modest protective effect against colorectal adenomas, precursors of most colorectal cancers.
Closed-form expressions for the outage and ergodic Shannon capacity of MIMO MRC systems

Transmit-beamforming (TB) over multiple-input multiple-output (MIMO) fading channels steers the transmit power in the receiver's direction, so as to maximize the output signal-to-noise ratio (SNR) after maximal ratio combining (MRC) at the receiver. This letter proposes a simple algorithm that allows evaluating an exact and tractable expression for the probability density function of the SNR at the output of the TB receiver, subject to Rayleigh fading. The latter enables the derivation of closed-form expressions for the outage and ergodic capacity of MIMO MRC systems under Rayleigh fading, thereby avoiding the need for time-consuming numerical integrations or Monte Carlo simulations.
Ubiquitin facilitates a quality-control pathway that removes damaged chloroplasts

Quality control one chloroplast at a time How do plant cells get rid of chloroplasts that are not working as they should? Woodson et al. describe a chloroplast quality-control pathway that allows for the selective elimination of individual chloroplasts. Damage by reactive oxygen species during photosynthesis is recognized by a ubiquitin ligase, which marks out damaged chloroplasts for degradation. The findings reveal how cells balance inherently stressful energy production with organelle turnover. Science, this issue p. 450 Singlet oxygen accumulation marks severely stressed chloroplasts for degradation. Energy production by chloroplasts and mitochondria causes constant oxidative damage. A functioning photosynthetic cell requires quality-control mechanisms to turn over and degrade chloroplasts damaged by reactive oxygen species (ROS). Here, we generated a conditionally lethal Arabidopsis mutant that accumulated excess protoporphyrin IX in the chloroplast and produced singlet oxygen. Damaged chloroplasts were subsequently ubiquitinated and selectively degraded. A genetic screen identified the plant U-box 4 (PUB4) E3 ubiquitin ligase as being necessary for this process. pub4-6 mutants had defects in stress adaptation and longevity. Thus, we have identified a signal that leads to the targeted removal of ROS-overproducing chloroplasts.
Examining Childhood Bullying and Adolescent Suicide

Adolescent suicide is a preventable tragedy yet is still the third leading cause of death in young people of age 10–24. Contrary to the idea that childhood bullying is a normal part of growing up or a rite of passage, it is now correlated with adolescent suicidality. An integrative review of the contemporary, extant literature was conducted to examine the following question: Are adolescents who have been involved in childhood bullying or cyberbullying as victim, offender, or victim/offender at greater risk for suicidality than those who have not. It is important to empower school nurses with current and evidence-based information regarding childhood bullying and examine empirical science and tools to effectively address the current serious problem of adolescent suicide risk assessment and intervention.
Recursive algorithms for multiuser detection over DS-CDMA channels

We focus on the synthesis and the analysis of recursive receivers for direct-sequence code-division multiple-access systems aimed at achieving satisfactory performance at the price of a moderate computational complexity. At the analysis stage, some interesting properties shared by the proposed procedures are proven. Finally, the performance assessment shows that the new schemes are superior to the linear detectors, and some of them achieve a bit-error rate close to that of the optimum receiver.
Short-Term Nutrition Intervention Increases Calcium Intake Among 45-54 Year Old Women

Abstract The purpose of this study was to investigate selected factors related to calcium and change in calcium intake after an intervention among a self-selected sample of 45-54 year old women. The theoretical bases for the research were the Health Belief Model and the health locus of control. The pre-intervention study consisted of 167 women. A total of 152 (91% return rate) completed and returned use-able post-test questionnaires. According to the multidimensional health locus of control results, this group had high scores for the internal locus of control. Similarly, the participants' attitudes related to the Health Belief Model were highly positive. Prior to the intervention, participants had a mean calcium intake of 1,423 mg/day that increased to 1,614 mg/day after the intervention. Participants reported significant increase in frequency of exercise and a decrease in the consumption of caffeine-containing beverages after the intervention. Based on these findings, it is reasonable to conclude that the educational intervention was likely to have been responsible for changing some of the participants' dietary and lifestyle behaviors.
Fast convenient numerical computation of lognormal characteristic functions

No closed-form expression is known for the lognormal characteristic function. Computation of the characteristic function using numerical integration is time consuming and often converges poorly. Alternative published numerical methods for its evaluation are complex and often valid only for particular values of the dB-spread. A novel definite integral form of the lognormal characteristic function is derived. This form lends itself to rapid and convenient computation of the lognormal characteristic function using simple, common methods of numerical integration.
User Innovators: When Patients Set Out to Help Themselves and End Up Helping Many

We investigate the motives and activities of individual user innovators in healthcare, focusing on patients of various diseases. More specifically we investigate the role of patients in the development of new treatments, therapies or medical devices (TTM the injection port, a medical device for diabetes patients who need daily injections, and the shower shirt, to protect mastectomy patients from post-surgical infection, among other. We identify three particular mechanisms (i.e., rare conditions, strong constraints on daily life, and dead end situations) that systematically produce inappropriateness in health care provision as perceived by the patient. Furthermore, we identify four individual innovation strategies that patients used to transform their needs into innovations. Last, we show that by changing their role once – from patient to patient-innovator – individuals were able to help themselves, and by changing it again – from patient-innovators to producers of medical devices – they succeeded in helping many others and in finding a way to add their valuable contribution to the existing health care system.
Strategies of Adolescent Girls and Boys for Coping With School-Related Stress

Stress among adolescents in Western societies is becoming an issue of increasing concern of adolescent’s health. The aim of this study was to gain greater knowledge about how girls and boys perceive and cope with school-related stress. Participants were 14- to 15-year-old adolescents from a medium-sized municipality in southern Sweden. The data were collected from focus group interviews. The data were subjected to qualitative content analysis. The findings show that adolescents “prioritizing the future or the present by making choices, finding their own private sphere to relax, and recovering with family and friends. ” There were gender differences in how these strategies were used. The findings could be used for initiating and planning health promotion interventions in school with focus on supporting girls’ and boys’ equal terms to cope with school-related stress in present and for the future and to give equal condition for future studies and opportunities in life.
SNR estimation algorithm based on the preamble for OFDM systems in frequency selective channels

We propose a new SNR estimation method based on the preamble for OFDM systems in frequency selective channels. The OFDM training symbols in the preamble are equalized by the known data in frequency domain and employed to estimate the noise variance. The second order moments of the received symbols are used to estimate the signal plus noise power in the OFDM packets. The SNRs on the subchannels and the average SNR of the packets can all be estimated. Simulation results show that the proposed method is robust to frequency selectivity in wireless channels, and its performance is considerably improved compared with the available methods.
Accumulate codes based on 1+D convolutional outer codes

A new construction of good, easily encodable, and soft-decodable codes is proposed in this paper. The construction is based on serially concatenating several simple 1+D convolutional codes as the outer code, and a rate-1 1/(1+D) accumulate code as the inner code. These codes have very low encoding complexity and require only one shift-forward register for each encoding branch. The input-output weight enumerators of these codes are also derived. Divsalariquests simple bound technique is applied to analyze the bit error rate performance, and to assess the minimal required signal-to-noise ratio (SNR) for these codes to achieve reliable communication under AWGN channel. Simulation results show that the proposed codes can provide good performance under iterative decoding.
Effective Recruitment of Schools for Randomized Clinical Trials: Role of School Nurses

In school settings, nurses lead efforts to improve the student health and well-being to support academic success. Nurses are guided by evidenced-based practice and data to inform care decisions. The randomized controlled trial (RCT) is considered the gold standard of scientific rigor for clinical trials. RCTs are critical to the development of evidence-based health promotion programs in schools. The purpose of this article is to present practical solutions to implementing principles of randomization to RCT trials conducted in school settings. Randomization is a powerful sampling method used to build internal and external validity. The school’s daily organization and educational mission provide several barriers to randomization. Based on the authors’ experience in conducting school-based RCTs, they offer a host of practical solutions to working with schools to successfully implement randomization procedures. Nurses play a critical role in implementing RCTs in schools to promote rigorous science in support of evidence-based practice.
Compress-spread-forward with multiterminal source coding and complete complementary sequences

Wireless video multicast over multiple base stations is an attractive setup for live, high-performance multimedia communications. We propose a new technique, termed compress-spread-forward (CSF), for real-time wireless video streaming over two base stations. CSF uses multiterminal source coding for efficient source compression, and complete complementary (CC) sequences for facilitating error-free multiple access and synchronization. The encoded video is sent to the base stations, which do not decode the received signals, but instead only compress them using multiterminal source coding, and then apply CC spreading before forwarding the result to the mobile client. We develop CC sequences for uplink communication and design a practical system using scalar quantization and turbo/LDPC codes for multiterminal source coding, and convolutional codes for additional error protection coding. Our experimental results show significant performance gains due to spatial diversity and distributed source coding.