Miracle-dz/UniFAR-FTUs huggingface dataset:
Random Matrix Derived Shrinkage of Spectral Precision Matrices

There has been much research on shrinkage methods for real-valued covariance matrices and their inverses (precision matrices). In spectral analysis of p-vector-valued time series, complex-valued spectral matrices and precision matrices arise, and good shrinkage methods are often required, most notably when the estimated complex-valued spectral matrix is singular. As an improvement on the Ledoit-Wolf (LW) type of spectral matrix estimator we use random matrix theory to derive a Rao-Blackwell estimator for a spectral matrix, its inverse being a Rao-Blackwellized estimator for the spectral precision matrix. A random matrix method has previously been proposed for complex-valued precision matrices. It was implemented by very costly simulations. We formulate a fast, completely analytic approach. Moreover, we derive a way of selecting an important parameter using predictive risk methodology. We show that both the Rao-Blackwell estimator and the random matrix estimator of the precision matrix can substantially outperform the inverse of the LW estimator in a time series setting. Our new methodology is applied to EEG-derived time series data where it is seen to work well and deliver substantial improvements for precision matrix estimation.
Lithium Isotopes in Population II Dwarfs

We address the evolution of lithium in Population II dwarf stars under the joint effects of microscopic diffusion and tachocline mixing. This process relies on analytical developments and is also constrained by helioseismology observations. It was successfully applied to solar analogs but never investigated in halo stars. It is induced in the upper radiation zone by rotation and a slight differential rotation in latitude. Consequently we modeled different possible rotation histories of halo stars, showing that the initial rotation rate had no impact on lithium in the framework of tachocline mixing. We find a negligible impact of pre-main-sequence evolution on 7Li independent of metallicity provided that [ Fe/H ] < − 1. On the contrary, microscopic diffusion and tachocline turbulence act on the long term of main sequence and shape the current 7Li − Teff pattern from the turnoff down to 5000 K. The tachocline mixing models fit the 7Li-Teff relation better than the pure microscopic diffusion models. We address the issue of warm 7Li-poor stars and conclude that a moderate mass transfer from a companion could explain their composition. Finally, we discuss the lithium lighter isotope. The pre-main-sequence and main-sequence 6Li depletion we compute seems difficult to reconcile with the current observations.
Comparison between Minimum Direct and Indirect Jerks of Linear Dynamic Systems

Both the minimum energy consumption and smoothness, which is quantified as a function of jerk, are generally needed in many dynamic systems such as the automobile and the pick-and-place robot manipulator that handles fragile equipments. Nevertheless, many researchers come up with either solely concerning on the minimum energy consumption or minimum jerk trajectory. This research paper proposes a simple yet very interesting relationship between the minimum direct and indirect jerks approaches in designing the time-dependent system yielding an alternative optimal solution. Extremal solutions for the cost functions of direct and indirect jerks are found using the dynamic optimization methods together with the numerical approximation. This is to allow us to simulate and compare visually and statistically the time history of control inputs employed by minimum direct and indirect jerk designs. By considering minimum indirect jerk problem, the numerical solution becomes much easier and yields to the similar results as minimum direct jerk problem. Keywords—Optimization, Dynamic, Linear Systems, Jerks.
Strategies for finding stable paths in mobile wireless ad hoc networks

In this paper, we introduce statistical methods to estimate the stability of paths in a mobile wireless ad hoc environment. Identifying stable paths helps to reduce control traffic and the number of connection interruptions. By means of simulation, we analyse the stability of paths chosen according to a variety of strategies, including those used by the well-known routing protocols, AODV and DSR, under a variety of different mobility patterns. This offers new insights into the relation between a path's stability and other characteristics and shows that our statistical metrics are able to identify stable paths in a wide range of scenarios.
An Interactive Robot in a Nursing Home: Preliminary Remarks

There are a growing number of robots being designed and built to interact with people in a specific setting. Our interdisciplinary team is taking a look at one of these robots, Paro, in its intended setting in order to study the effects of the interaction. By using a combination of self-report, analysis of interactions, and postinteraction interviews, we examine social and psychological aspects of seniors interacting with the robot in nursing home settings. We examine the relationship between the person and the robot, the individual’s feelings about relationships with others and how this changes during the robot interactions. In this paper, we report our initial findings based on fieldwork at two nursing homes over the course of multiple interactions.
An Importance Sampling Simulation Method for Bayesian Decision Feedback Equalizers

An importance sampling (IS) simulation technique is presented for evaluating the lower-bound bit error rate (BER) of the Bayesian decision feedback equalizer (DFE) under the assumption of correct decisions being fed back. A design procedure is developed, which chooses appropriate bias vectors for the simulation density to ensure asymptotic efficiency of the IS simulation.
Investigating hot gas in the halos of two massive spirals: Observations and cosmological simulations

Models of disk galaxy formation commonly predict the existence of an extended reservoir of hot gas surrounding massive spirals at low redshift. As a test of these models, we have obtained X-ray and optical data of the two massive edge-on spirals NGC 5746 and NGC 5170, in order to investigate the amount and origin of hot gas in their disks and halos. Chandra observations of NGC 5746 reveal evidence for diffuse X-ray emission with a total luminosity of ∼ 7 × 10 39 erg s −1 surrounding this galaxy out to at least ∼ 20 kpc from the disk, whereas an identical study of the less massive NGC 5170 fails to detect any extraplanar X-ray emission. Unlike the case for other disk galaxies with detected � /�
Compound Heterozygous Mutations in SLC30A2/ZnT2 Results in Low Milk Zinc Concentrations: A Novel Mechanism for Zinc Deficiency in a Breast-Fed Infant

Zinc concentrations in breast milk are considerably higher than those of the maternal serum, to meet the infant's requirements for normal growth and development. Thus, effective mechanisms ensuring secretion of large amounts of zinc into the milk operate in mammary epithelial cells during lactation. ZnT2 was recently found to play an essential role in the secretion of zinc into milk. Heterozygous mutations of human ZnT2 (hZnT2), including H54R and G87R, in mothers result in low (>75% reduction) secretion of zinc into the breast milk, and infants fed on the milk develop transient neonatal zinc deficiency. We identified two novel missense mutations in the SLC30A2/ZnT2 gene in a Japanese mother with low milk zinc concentrations (>90% reduction) whose infant developed severe zinc deficiency; a T to C transition (c.454T>C) at exon 4, which substitutes a tryptophan residue with an arginine residue (W152R), and a C to T transition (c.887C>T) at exon 7, which substitutes a serine residue with a leucine residue (S296L). Biochemical characterization using zinc-sensitive DT40 cells indicated that the W152R mutation abolished the abilities to transport zinc and to form a dimer complex, indicating a loss-of-function mutation. The S296L mutation retained both abilities but was extremely destabilized. The two mutations were found on different alleles, indicating that the genotype of the mother with low milk zinc was compound heterozygous. These results show novel compound heterozygous mutations in the SLC30A2/ZnT2 gene causing zinc deficiency in a breast-fed infant.
RESTITUTION OF PANCREATIC ACINAR CELLS FOLLOWING ETHIONINE

The regeneration of the pancreatic acinar cell was studied at four time periods after ethionine had destroyed most of the acinar cells. Within 2 days of the last ethionine injection, small basophilic cells (pre-acinar cells) with whorls of ergastoplasm or nebenkern were present. These cells also contained a decreased amount of Golgi substance, small zymogen granules, and a fine granularity of the nuclear matrix. They showed persistence of the characteristic ergastoplasm lesion produced by ethionine. Eight days after the last ethionine injection, the nebenkern was replaced by approximately normal appearing ergastoplasm and the nucleoli and Golgi bodies were enlarged. Zymogen granules were less dense but more abundant. Mitochondria were considerably enlarged. Most cells showed no ethionine lesions or only small foci of damage. Eighteen days after the cessation of ethionine, a good approximation of the normal acinar cell was present. The whorls of ergastoplasm appeared at a time (day 12) when basophilia was pronounced. Other studies showed that nucleic acid and protein precursors began to show an increased concentration in acinar cells at this time. The appearance of nebenkern during a phase of cellular recovery and its absence during a phase of replication when mitotic indices were high suggest that its presence is more indicative of ergastoplasmic synthesis than of cell multiplication as such. Possibly the increased density of zymogen granules was a reflection of this increased protein synthesis. The increase in size of Golgi apparatus occurred prior to the replenishment of zymogen granules and thus satisfied a precursor relationship for a possible role in the formation of these secretory structures. Evidence suggests that some injured acinar cells recover from the ethionine and protein-free regimen and give rise to most of the new acinar cells formed. It is possible that, under the severe conditions which prevailed, the centroacinar ductule cells may also have given rise to some acinar cells.
Some Secondary Metabolites in Leaves of Echinodorus grandiflorus (Cham. & Schldl.) Micheli in Brazil

The paper aimed to study the influence of naphthalene acetic acid (NAA) and ethephon on total phenols, fla- vonoids and tannins as a function of seasonality in Echinodorus grandiflorus plants. The experiment used adventitious plantlets from the flower stem with 4 to 5 leaves, planted in 10-liter pots. The leaf spray treatments applied were: control, NAA 100 mg L -1 , and ethephon 100 mg L -1 . Treatments were applied fifteen days after collecting the leaf blades, once at each season of the year. The results showed that plant growth regulators did not influence E. grandiflorus' phenology and morphology. The ethephon did not affect synthesis of total phenols and flavonoids. The NAA caused a decrease in the synthesis of total phenols and flavonoids in some periods. Tannin synthesis is not expressive in E. grandiflorus. The study presented information about ecological aspects and chemical and mechanical defenses of Echinodorus grandiflorus.
The absence of centrioles from spindle poles of rat kangaroo (PtK2) cells undergoing meiotic-like reduction division in vitro

Light and electron microscopy were used to study somatic cell reduction division occurring spontaneously in tetraploid populations of rat kangaroo Potorous tridactylis (PtK2) cells in vitro. Light microscopy coupled with time-lapse photography documented the pattern of reduction division which includes an anaphase-like movement of double chromatid chromosomes to opposite spindle poles followed by the organization of two separate metaphase plates and synchronous anaphase division to form four poles and four daughter nuclei. The resulting daughter cells were isolated and cloned, showing their viability, and karyotyped to determine their ploidy. Ultrastructural analysis of cells undergoing reduction consistently revealed two duplexes of centrioles (one at each of two spindle poles) and two spindle poles in each cell that lacked centrioles but with microtubules terminating in a pericentriolar-like cloud of material. These results suggest that the centriole is not essential for spindle pole formation and division and implicate the could region as a necessary component of the spindle apparatus.
Predicting the future with stem cells.

> The best way to predict future is to invent it. > > —Alan Kay The efficacy of bypass surgery in patients with ischemic cardiomyopathy remains impossible to forecast accurately. In particular, individual variability in factors such as disease comorbidities, genetic background, aging, disease progression, lifestyle, and medications makes the prediction of the outcome of bypass surgery1 a herculean task. Identifying readily available patient-specific information to prognosticate the likelihood of benefit with highly invasive procedures such as bypass surgery not only could minimize patient suffering but also could significantly reduce the cost and resource burdens on a healthcare system that is already stretched to the limit. Article see p 157 Over the last several years, the cardiovascular field has embraced (with varying degrees of enthusiasm) regenerative medicine. Indeed, expert opinions in the field have ranged from beliefs that stem cells can do virtually anything (eg, repair and replace damaged myocardium) to the notion that they are essentially useless (eg, whatever observed biological effects are functionally meaningless). Despite the ongoing debate, most available evidence now suggests that the heart is a self-renewing organ to some (yet to be clarified) extent and that such reparative processes involve a resident pool of self-replicating and renewing c-kit–positive cardiac stem cells (CSCs). 2,3 CSCs have been shown to repair damaged heart after myocardial infarction,4 to contribute to neomyogenesis and angiogenesis,5 and to augment heart function.6 If the functional outcome of bypass surgery depends substantially on the functional competency of CSCs, then forecasting the potential benefit of major surgical interventions such as coronary bypass grafting may be accomplished by preemptively assessing the regenerative potential of the CSC pool. …
Real Challenges in Mobile App Development

Context: Mobile app development is a relatively new phenomenon that is increasing rapidly due to the ubiquity and popularity of smartphones among end-users. Objective: The goal of our study is to gain an understanding of the main challenges developers face in practice when they build apps for different mobile devices. Method: We conducted a qualitative study, following a Grounded Theory approach, in which we interviewed 12 senior mobile developers from 9 different companies, followed by a semi-structured survey, with 188 respondents from the mobile development community. Results: The outcome is an overview of the current challenges faced by mobile developers in practice, such as developing apps across multiple platforms, lack of robust monitoring, analysis, and testing tools, and emulators that are slow or miss many features of mobile devices. Conclusion: Based on our findings of the current practices and challenges, we highlight areas that require more attention from the research and development community.
A pilot study of photoplethysmographic peripheral pulse transit times in paediatric heart transplant recipients and healthy children

Previous studies have demonstrated increased arterial stiffness (AS) in paediatric heart transplant recipients (HTR) by using established SphygmoCor technology. The aim of this study was to assess pulse transit times at three different peripheral body sites in HTR, and in comparison to healthy controls, by using relatively low-cost and easy-to-perform photo plethysmography (PPG) technology. PPG waveforms and an electrocardiography timing reference were recorded from 12 HTR (age range 8-17 years; 5 males) and 30 healthy children (age range 8-16 years; 15 males) from the right and left ear lobes, index fingers, and great toes. The median values for pulse transit times to PPG-pulse foot (PTTj) were calculated over a period of 60 heart beats, with right and left sides averaged at each segmental site. Toe PTTf was significantly shorter in HTR (median 290 ms) compared to controls (324 ms, p <; 0.05). No significant differences were found for ear and finger PTTj Furthermore, toe PTTf significantly correlated with subject height both in HTR (ρ = 0.78, p <; 0.01, slope = 88 ms/m) and controls (ρ = 0.76, p <; 0.001, slope = 132 ms/m). A shorter PTTf at the toe site is consistent with increased AS in paediatric heart transplant recipients and the results from correlation analysis further corroborated this finding.
Temporal regulation of shoot development in Arabidopsis thaliana by miR156 and its target SPL3

SPL3, SPL4 and SPL5 (SPL3/4/5) are closely related members of the SQUAMOSA PROMOTER BINDING PROTEIN-LIKE family of transcription factors in Arabidopsis, and have a target site for the microRNA miR156 in their 3 ′ UTR. The phenotype of Arabidopsis plants constitutively expressing miR156-sensitive and miR156-insensitive forms of SPL3/4/5 revealed that all three genes promote vegetative phase change and flowering, and are strongly repressed by miR156. Constitutive expression of miR156a prolonged the expression of juvenile vegetative traits and delayed flowering. This phenotype was largely corrected by constitutive expression of a miR156-insensitive form of SPL3. The juvenile-to-adult transition is accompanied by a decrease in the level of miR156 and an increase in the abundance of SPL3 mRNA. The complementary effect of hasty on the miR156 and SPL3 transcripts, as well as the miR156-dependent temporal expression pattern of a 35S::GUS-SPL3 transgene, suggest that the decrease in miR156 is responsible for the increase in SPL3 expression during this transition. SPL3 mRNA is elevated by mutations in ZIPPY/AGO7, RNA DEPENDENT RNA POLYMERASE 6 (RDR6) and SUPPRESSOR OF GENE SILENCING 3 (SGS3), indicating that it is directly or indirectly regulated by RNAi. However, our results indicate that RNAi does not contribute to the temporal expression pattern of this gene. We conclude that vegetative phase change in Arabidopsis is regulated by an increase in the expression of SPL3 and probably also SPL4 and SPL5, and that this increase is a consequence of a decrease in the level of miR156.
Self-esteem analyses in people who are deaf or hard of hearing: a comparison between active and inactive individuals

The aim of the study was to analyse the status of SE in people who are deaf or hard of hearing (D/HH) and compare SE scores between active and inactive individuals. The sample of people who are D/HH (n=117) was divided into two groups of those who are regularly participating in sport (active; n=27) and those who are not participating in any sport in their leisure (inactive; n=90). The Rosenberg Self-Esteem Scale (RSES) was used as a primary research method. 10-item scale measures global selfworth by measuring positive and negative feelings about the self. Higher scores (from 10 to 40 points) indicate higher SE. The Pearson chi-square test was used to determine the differences of 10 RSES items and total scores between active and inactive people who are D/HH. We found that the mean score of RSES in the group of people who are D/HH was 28.83 points; active people who are D/HH observed total score of RSES 30.18 points and group of inactive people who are D/HH showed the lowest SE by achieving 28.89 points. Mean scores comparison of each RSES item between active and inactive people who are D/HH revealed higher SE in the group of active people with hearing loss. Significantly higher SE of active people who are D/HH was presented only by 1 from 10 RSES items. The results of our study confirmed that actively living people with hearing loss have higher SE comparing those who are living sedentary life style.
EmailCloak: A Practical and Flexible Approach to Improve Email Privacy

Millions of users rely on email providers to manage and store their personal communications. This vast amount of private information, however, is often misused not only by adversaries, but also by the providers themselves. End-to-end email encryption is considered the most robust defense against this threat, however, its many requirements make this approach impractical for protecting everyday emails. In this paper, we present Email Cloak, an email alias service with public key encryption capabilities. Email Cloak relaxes email encryption requirements by relying on a privacy-respecting third-party. Emails sent and received by the user are automatically encrypted with her public key by Email Cloak before being forwarded to, and stored by her email provider. This approach, while seemingly straightforward, offers multiple benefits: simplified key management, selective and automatic encryption, advanced deployment options and transparency towards other parties. Moreover, our experimental evaluation shows that the overhead introduced by Email Cloak is adequate for email communications. We have also made our implementation publicly available. In doing so, we deliver a practical and flexible tool that provides privacy-concerned users with greater control over their stored emails.
Maximal Voluntary Co-Contraction Training may not Always be Effective for Some Leg Muscles.

Simultaneous voluntary contractions of antagonistic pairs (co-contraction) produce resistive forces that act against each other (Maeo et al., 2013c). It has been reported that a training program in which subjects performed voluntary co-contractions of elbow flexors and extensors with maximal effort produced significant increases in the strength capability of both muscle groups, without the use of an external load as resistance (Maeo et al., 2013c). In addition, the level of their muscular activities during the task, expressed as the value relative to those during maximal voluntary contraction (MVC) of corresponding muscles (% EMGmax), has been shown to be a sufficient training stimulus (~40% for elbow flexors and ~60% for elbow extensors) for improving the strength capability of both muscle groups (Maeo et al., 2013c). Thus, it is considered that maximal voluntary co-contraction can be an effective form of resistance raining. However, the muscle groups examined previously are limited to the elbow flexors and extensors. It is known that the influence of aging on muscle mass is more apparent in the lower body than in the upper body (Janssen et al., 2000), and the antigravity muscles located in the lower extremity have a greater influence of decreased mechanical loading conditions such as bed rest, limb immobilization, and space flight (Kanehisa, 2005). To establish the efficacy of the co-contraction training, therefore, it is essential to clarify the muscle activation levels of lower limb muscles during the co-contraction tasks. In the task which requires maximal voluntary co-contractions of the upper arm muscles, stronger elbow flexors would need only to be activated to the extent to which they cancel the torque produced by weaker elbow extensors, resulting in a lower activation level in the elbow flexors than in the extensors during the task (Maeo et al., 2013a, c). On the other hand, in leg muscles, it is often reported that there are large differences in maximal strength between muscles in the antagonistic pairs (e.g. the knee extensors/flexors pair as well as the plantar flexors/dorsi flexors pair) (Billot et al., 2010; Macaluso et al., 2002). Thus, theoretically, it is assumed that during maximal voluntary co-contraction in the leg muscles, the stronger side of the muscle groups (i.e. knee extensors and plantar flexors) result in much lower level of the muscular activity than the weaker side (i.e. knee flexors and dorsi flexors). The present study aimed to clarify this by comparing the muscular activity levels of …