In recent years, several assistive devices have been proposed to reconstruct arm and hand movements from electromyographic (EMG) activity. Although simple to implement and potentially useful to augment many functions, such myoelectric devices still need improvement before they become practical. Here we considered the problem of reconstruction of handwriting from multichannel EMG activity. Previously, linear regression methods (e.g., the Wiener filter) have been utilized for this purpose with some success. To improve reconstruction accuracy, we implemented the Kalman filter, which allows to fuse two information sources: the physical characteristics of handwriting and the activity of the leading hand muscles, registered by the EMG. Applying the Kalman filter, we were able to convert eight channels of EMG activity recorded from the forearm and the hand muscles into smooth reconstructions of handwritten traces. The filter operates in a causal manner and acts as a true predictor utilizing the EMGs from the past only, which makes the approach suitable for real-time operations. Our algorithm is appropriate for clinical neuroprosthetic applications and computer peripherals. Moreover, it is applicable to a broader class of tasks where predictive myoelectric control is needed.
Abstract The role of genes in the expression of aggression and masculinity traits in humans has been a focus of recent behavioral genetic studies. This is the first study on the variation in aggression, the digit ratio (the ratio between the second and the fourth digits, 2D:4D), the directional asymmetry in 2D:4D (DR-L) and polymorphisms of the AR, DRD4, and 5-HTTL genes in simple hunter-gatherers, namely the Hadza of Tanzania (142 adult men). The distribution of AR, DRD4E3, and 5-HTTLPR genotypes and allele frequencies in Hadza was compared to other African populations on which the data were available. Hadza and Ariaal differed significantly in the distributions of frequencies of AR alleles with different numbers of CAG repeats. Hadza population was similar to other African populations in the distribution of allelic frequencies of the DRD4E3 locus, and to Afro- Americans in the distribution of allelic types of the 5- HTTLPR locus. We found no influence of AR gene on the right hand 2D:4D ratio,DR-L, and any of aggression subscales of the Buss-Perry Aggression Questionnaire (AQ). Although, a weak positive correlation between CAG repeats and the left hand 2D:4Dwas found. The multiple regression analysis with digit ratios, DR-L and aggression subscales of AQ as dependent variables and the three gene candidates (AR, DRD4E3, and 5-HTTLPR) as independent variables revealed the following: men with lower number of CAG repeats had significantly lower left hand2D:4D ratio;men with highernumbers of 48-bp unit copies in exon 3 of a VNTR polymorphism in the DRD4 gene had significantly lower digit ratios on both hands; no effect of the 5-HTTLPR gene on either the digit ratio or aggressive behavior. These findings demonstrate the complexity of gene effects on digit ratios and aggression and call for simultaneous analysis of more candidate genes. It is noteworthy that these results were obtained for a human population that is still practicing foraging and has been subjected to a high selective pressure due to harsh environments and practically has no access to modern medical care. Hadza are highly egalitarian, and their culture does not favor persons with a dominant or aggressive behavior. It is still to be found to what extent the relationships observed in this study are similar to those in other human populations.
Предложена общая континуальная модель среды, составленной механически активными клетками. Среда считается состоящей из трех фаз; собственно клеток, внеклеточной жидкости и дополнительной фазой, отвечающей за активное силовое взаимодействие между клетками, которая, в частности, может соответствовать системе протрузий, обеспечивающих развитие активных стягивающих усилий. Деформация среды, отождествляемая с деформацией клеточной фазы, состоит из двух составляющих: упругой деформации отдельных клеток и клеточных переупаковок. Упругая деформация связана с напряжением в клеточной фазе. Шаровая составляющая тензора напряжений описывает нелинейное сопротивление клеточной фазы, обеспечивающее невозможность ее слишком большого сжатия. Уравнение состояния для давления в клеточной фазе принято в виде нелинейной зависимости от объемной плотности клеток. Переупаковка клеток рассматривается как течение, управляемое напряжениями в клеточной фазе, активными напряжениями и давлением жидкости. Тензор активных напряжений полагается шаровым и нелокально зависящим от плотности клеток. В предположении медленности процесса деформирования биологической ткани получена редуцированная модель, в которой пренебрегается упругими деформациями клеток по сравнению с неупругими. Проведен дисперсионный анализ устойчивости пространственно-однородного стационарного решения. Среди параметров, отвечающих за потерю устойчивости, присутствует гидростатическое давление жидкости, возрастание которого приводит к неустойчивости за счет составляющей силы межфазного взаимодействия, обусловленной этим давлением. Полученная модель используется для описания процесса образования полости в первоначально однородном клеточном сфероиде. Исследована роль локального и нелокального механизмов развития активных напряжений при формировании полости.
The spring-to-summer transition is of special importance in long range forecasting, as the general circulation transitions to a less energetic regime. This affects the Midwestern United States in a profound way, since agriculture is very sensitive to the variability of weather and climate. Beginning at the local scale, surface temperature observations are used from a representative station in the West Central Missouri Plains region in order to identify the shift from late spring to early summer. Using upper-air re-analyses as a supplement, the 500-mb height observations are examined to find a spring-to-summer transition date by tracking the location of a representative contour. Each of these is used to identify spring-to-summer transition date and then statistical analysis is performed on this long-term data set. Finally, teleconnections, specifically the influence of El Niño Southern Oscillation (ENSO) and Pacific Decadal Oscillation (PDO), and blocking are examined in order to quantify interannual variability. It was found that examining these criteria, developed in an earlier study that covered a much shorter time period, produced similar statistics to this 68-year study of spring-to-summer transitions. It was also found that the onset of La Niña was associated with hotter summers in the region, a result first found in the earlier study, but this association in much stronger here.
The article discusses the dramatic history of the Tsaritsyno Park and museum-reserve. By the mid-2000s, it had become one of Moscow's iconic places and a zone where urban public culture was shaped. The authors trace the history of this architectural ensemble and park in terms of their role in сity culture and analyse changes in the historical culture of contemporary post-Soviet Moscow. The Tsaritsyno Park and museum exemplify these changes. An unfinished country residence of Catherine II, with a Grand Palace that had stood as a ruin for over 200 years, it has been radically renewed by the Moscow city authorities in what came to be labelled ‘fantasy restoration’. The palace was finished and now serves as the core of the museum, organized according to a controversial historical policy. Tsaritsyno as a whole became a cultural oddity featuring historical attractions for the public, effectively an ‘eighteenth-century theme park’.
The fractal globule state is a popular model for describing chromatin packing in eukaryotic nuclei. Here we provide a scaling theory and dissipative particle dynamics computer simulation for the thermal motion of monomers in the fractal globule state. Simulations starting from different entanglement-free initial states show good convergence which provides evidence supporting the existence of a unique metastable fractal globule state. We show monomer motion in this state to be subdiffusive described by X2(t) ∼tαF with αF close to 0.4. This result is in good agreement with existing experimental data on the chromatin dynamics, which makes an additional argument in support of the fractal globule model of chromatin packing. © 2015 American Physical Society.
Ранее публиковавшиеся биографические очерки о создателе теории фаз саранчи сэре Борисе Уварове, сэре Борисе Уварове, рыцаре-командоре ордена св. Михаила и св. Георгия и члене Лондонского королевского общества (1886 [sic] — 1970) были основаны главным образом на личных воспоминаниях его друзей и коллег, записанных в 1970 году или позднее. Архивные исследования обнаруживают подлинную дату его рождения и позволяют уточнить некоторые другие важные факты и даты его ранней биографии.
In this paper a novel clustering algorithm is proposed as a version of the Seeded Region Growing (SRG) approach for the automatic recognition of coastal upwelling from Sea Surface Temperature (SST) images. The new algorithm, One Seed Expanding Cluster (SEC), takes advantage of the concept of approximate clustering due to Mirkin (1996, 2013) to derive a homogeneity criterion in the format of a product rather than the conventional difference between a pixel value and the mean of values over the region of interest. It involves a boundary-oriented pixel labeling so that the cluster growing is performed by expanding its boundary iteratively. The starting point is a cluster consisting of just one seed, the pixel with the cold est temperature. The baseline version of the SEC algorithm uses the Otsu’s thresholding method to fine-tune the homogeneity threshold. Unfortunately, this method does not always lead to a satisfactory solution. Therefore, we introduce a self-tuning version of the algorithm in which the homogeneity threshold parameter is abolished and the similarity threshold derived from the approximation criterion also serves as a homogeneity parameter.
Ribosomal protein S2 is an essential component of translation machinery, and its viable mutated variants conferring distinct phenotypes serve as a valuable tool in studying the role of S2 in translation regulation. One of a few available rpsB mutants, rpsB1, shows thermosensitivity and ensures enhanced expression of leaderless mRNAs. In this study, we identified the nature of the rpsB1 mutation. Sequencing of the rpsB1 allele revealed a G-to-A transition in the part of the rpsB gene which encodes a coiled-coil domain of S2. The resulting E132K substitution resides in a highly conserved site, TKKE, a so-called N-terminal capping box, at the beginning of the second alpha helix. The protruding coiled-coil domain of S2 is known to provide binding with 16S rRNA in the head of the 30S subunit and, in addition, to interact with a key mRNA binding protein, S1. Molecular dynamics simulations revealed a detrimental impact of the E132K mutation on the coiled-coil structure and thereby on the interactions between S2 and 16S rRNA, providing a clue for the thermosensitivity of the rpsB1 mutant. Using a strain producing a leaderless lacZ transcript from the chromosomal lac promoter, we demonstrated that not only the rpsB1 mutation generating S2/S1-deficient ribosomes but also the rpsA::IS10 mutation leading to partial deficiency in S1 alone increased translation efficiency of the leaderless mRNA by about 10-fold. Moderate overexpression of S1 relieved all these effects and, moreover, suppressed the thermosensitive phenotype of rpsB1, indicating the role of S1 as an extragenic suppressor of the E132K mutation.