Did the Popsicle Melt? Preschoolers’ Performance in an Episodic-like Memory Task

Episodic memory has been tested in non-human animals using depletion paradigms that assess recollection for the “what,” “where” and “when” (i.e., how long ago). This paradigm has not been used with human children, yet doing so would provide another means to explore their episodic memory development. Using a depletion paradigm, preschool-aged children were presented in two trials with a preferred food that was only edible after a short interval and a less preferred food that was edible after the short and long intervals. Younger (mean= 40 months) and older (mean=65 months) children tended to choose their preferred food after the short intervals, but did not switch to selecting their less-preferred food after the long intervals. Importantly, their choices did not differ with age. Although older children better remembered “what”, “where” and “what is where” than did younger children, neither age group successfully estimated “how long ago” an event occurred. Finally, both age groups spontaneously recalled information about Trial 1. We also analyzed the relation between the different measures used in the study but no clear patterns emerged. Results are discussed with respect to the cognitive mechanisms necessary to succeed in depletion paradigms and the measurement of episodic memory more broadly

Out of the Box? How Managing a subordinate\u27s Multiple Identities Affects the Quality of a Manager-Subordinate Relationship

Positive manager-subordinate relationships are invaluable to organizations because they enable positive employee attitudes, citizenship behaviors, task performance, and more effective organizations. Yet extant theory provides a limited perspective on the factors that create these types of relationships. We highlight the important role subordinates also play in affecting the resource pool and propose that a subordinate’s multiple identities can provide him or her with access to knowledge and social capital resources that can be utilized for work-based tasks and activities. A manager and a subordinate may prefer similar or different strategies for managing the subordinate’s multiple identities, however, which can affect resource utilization and the quality of the manager-subordinate relationship. Our variance model summarizes our predictions about the effect of managers’ and subordinates’ strategy choices on the quality of manager-subordinate relationships. In doing so we integrate three divergent relational theories (leader-member exchange theory, relational-cultural theory, and a positive organizational scholarship perspective on positive relationships at work) and offer new insights on the quality of manager-subordinate relationships

Detection of non random phase signal in additive noise with Surrogate Analysis

The Surrogate Analysis (SA) is known to detect nonlinear signals, non-stationary signals and ARMA systems driven by non-Gaussian processes. This paper adds to address the detection of non-random phase signal, of which the linear phase signal is the best-known example. This is a new interpretation of the SA. In order to highlights the benefits of the interpretation, a new theoretical signals is constructed. The signal has a perfect Gaussian distribution and is not affected by periodic extension and is a linear phase signal. The SA will be shown able to detect this signal in a noise with exactly the same power spectrum. It will be clear that the SA is able to detect phase linearity even when the data is normally distributed. An application of the detection by SA is given regarding very noisy and short time electrocardiogram (ECG) signal and compared to higher order statistics and normality tests for this purpose

Low group delay interpolation filter for Delta-Sigma converters

This paper shows how a relaxation of the high frequency requirements can help reducing the latency in linear phase interpolation filter, with an audio production system perspective. The reduced need for attenuation is justified when the interpolation filter is followed by a noise-shaping Delta-Sigma loop and an analog filtering stage. This is done by using a non-constant error weight of the stop-band. In order to use the Parks-McClellan method for finite impulse response filter design from Matlab, the stop-band is divided and weighted logarithmically. Quantitative results are shown for different example filter design, limited to situations where the Parks-McClellan converges well. It has been found that the shorter the filter length needed to respect a given filter template, the more relative group delay reduction can be achieved by relaxing the high frequency requirement. For filter size of the order of 100, reduction of group delay of 30% can be expected. For sake of simplicity, the Delta-Sigma loop is discussed but not analysed here. The idea is demonstrated in the context of Digital-to-Analog converters (DAC) but by duality could be applicable also to Analog-to-Digital converters (ADC). The main performance metric used is a relative reduction of the impulse response group delay. The results are also presented as impulse responses and power spectrum examples. The presented approach may be generalised to complex and non-linear phase filters and does not prevent the use of polyphase structures

Windowing compensation in Fourier based Surrogate Analysis

This paper shows how adding a second step of windowing after each phase randomization can reduce the False Rejection Rate in Fourier based Surrogate Analysis. Windowing techniques improve the resolution of the Power Spectrum estimation by reducing the sampling gap caused by the periodic extension of the Fourier Series. However, it adds a time domain non-stationarity which affects the Surrogate Analysis. This effect is particularly problematic for short lowpass signals. Applying the same window to the surrogate data allows having the same non-stationarity. The method is tested on order 1 autoregressive process null hypothesis by Monte Carlo simulations. Previous methods were not able to yield good performances for left-sided and right-sided tests at the same time, even less with bilateral tests. It is shown that the new method is conservative for unilateral tests as well as bilateral tests

Windowing compensation in Fourier based Surrogate Analysis and application to EEG signal classification

This paper shows how adding a second step of windowing after each phase randomization can reduce the False Rejection Rate in Fourier based Surrogate Analysis. Windowing techniques reduce the discontinuities at the boundaries of the periodically extended data sequence in Fourier Series. However, they add a time domain non-stationarity which affects the Surrogate Analysis. This effect is particularly problematic for short low-pass signals. Applying the same window to the surrogate data allows having the same non-stationarity. The method is tested on order 1 autoregressive process null hypothesis by Monte-Carlo simulations. Previous methods were not able to yield good performances for left-sided and right-sided tests at the same time, even less with bilateral tests. It is shown that the new method is conservative for unilateral tests as well as bilateral tests. In order to show that the proposed windowing method can be useful in real context, in this extended paper, it was applied for an EEG diagnostic problem. A dataset comprising the EEG measurements of 15 subject distributed in three groups: attention-deficit disorder primarily hyperactive-impulsive (ADHD), attention-deficit disorder primarily inattentive (ADD); and anxiety with attentional fragility (ANX) was used. Both statistical and machine learning (Naïve Bayesian) approaches were considered. The Mean Short Windowed SA (MSWSA) was used as a signal feature and its performances was studied with respect to the windowing systems. The main findings were that (i) the MSWSA feature has less variability for ADD than for ADHD or ANX, (ii) the proposed windowing method reduces bias and non-normality of the SA feature, (iii) with the proposed method and a naïve Bayesian classifier, a 93% success rate of discriminating ADD from ADHD and ANX was achieved with leave-one-out cross-validation, and (iv) the new feature could not have yielded interesting results without the proposed windowing system

Low peak derivative sum of sines

This paper proposes a method to generate multisines signals with reduced peak derivative. This is done by adjusting the phases in the Fourier domain with Genetic Algorithm such that in the time domain the maximum absolute signal's derivative is minimized. The performance evaluation is made by comparing the method to signals with the same spectrum but with phase adjusted randomly. It will be shown for an audio test signal case study of a multisines signal comprising 2500 sines that a reduction of 42% with respect to the mean maximum peak derivative and 31% with respect to the minimum maximum peak derivative over 1 million random trials. The proposed method is contrasted with a low crest factor signal method. It is found that there is a positive correlation between peak amplitude and peak derivative when signals are generated with random phases. Moreover, the signals obtained by minimizing either the peak amplitude of the peak derivative had also good performances with respect to the non-optimized criterion

Beamforming for powerline interference in large sensor arrays

This paper shows how to use beamforming to remove the power-line interference (PLI) in large surface electromyography (sEMG) sensor array or high-density sEMG. The method exploits the highly correlated nature of the different sources of interference, being part of the same electrical grid, and their narrow frequency bands. The idea is to use a very narrow pass-band filter around 50 or 60 Hz to get signals with high PLI content before applying a spatial filtering by principal component analysis (PCA). This way, beamforming are done on the frequency bands where PLI are presents. Also, it ensures that even if the PLI has a smaller overall power than the desired signal, it will be easily found as the most powerful component of the decomposition. The PLI can then be removed from the signal. With trivial modification, harmonics of the PLI can also be removed. The approach was used in the context of muscle behavior analyses of low back pain patients using a sEMG array of 64 sensors. The performances of the filter are studied by experimental and semi-empirical methods. Compared to the usual notch filter, an improvement of up 10 dB is found

Infections with Avian Pathogenic and Fecal Escherichia coli Strains Display Similar Lung Histopathology and Macrophage Apoptosis

The purpose of this study was to compare histopathological changes in the lungs of chickens infected with avian pathogenic (APEC) and avian fecal (Afecal) Escherichia coli strains, and to analyze how the interaction of the bacteria with avian macrophages relates to the outcome of the infection. Chickens were infected intratracheally with three APEC strains, MT78, IMT5155, and UEL17, and one non-pathogenic Afecal strain, IMT5104. The pathogenicity of the strains was assessed by isolating bacteria from lungs, kidneys, and spleens at 24 h post-infection (p.i.). Lungs were examined for histopathological changes at 12, 18, and 24 h p.i. Serial lung sections were stained with hematoxylin and eosin (HE), terminal deoxynucleotidyl dUTP nick end labeling (TUNEL) for detection of apoptotic cells, and an anti-O2 antibody for detection of MT78 and IMT5155. UEL17 and IMT5104 did not cause systemic infections and the extents of lung colonization were two orders of magnitude lower than for the septicemic strains MT78 and IMT5155, yet all four strains caused the same extent of inflammation in the lungs. The inflammation was localized; there were some congested areas next to unaffected areas. Only the inflamed regions became labeled with anti-O2 antibody. TUNEL labeling revealed the presence of apoptotic cells at 12 h p.i in the inflamed regions only, and before any necrotic foci could be seen. The TUNEL-positive cells were very likely dying heterophils, as evidenced by the purulent inflammation. Some of the dying cells observed in avian lungs in situ may also be macrophages, since all four avian E. coli induced caspase 3/7 activation in monolayers of HD11 avian macrophages. In summary, both pathogenic and non-pathogenic fecal strains of avian E. coli produce focal infections in the avian lung, and these are accompanied by inflammation and cell death in the infected areas