Ultraviolet vision in larval Neogonodactylus oerstedii

Stomatopod crustaceans have among the most complex eyes in the animal kingdom, with up to twelve different color detection channels. The capabilities of these unique eyes include photoreception of ultraviolet (UV) wavelengths (<400 nm). UV vision has been well characterized in adult stomatopods but has not been previously demonstrated in the comparatively simpler larval eye. Larval stomatopod eyes are developmentally distinct from their adult counterpart and have been described as lacking the visual pigment diversity and morphological specializations found in adult eyes. However, recent studies have provided evidence that larval stomatopod eyes are more complex than previously thought and warrant closer investigation. Using electroretinogram recordings in live animals we found physiological evidence of blue and UV sensitive photoreceptors in larvae of the Caribbean stomatopod species Neogonodactylus oerstedii. Transcriptomes of individual larvae were used to identify the expression of three distinct UV opsins transcripts, which may indicate the presence of multiple UV spectral channels. This is the first paper to document UV vision in any larval stomatopod, expanding our understanding of the importance of UV sensitivity in plankton. Similar to adults, larval stomatopod eyes are more complex than expected and contain previously uncharacterized molecular diversity and physiological functions.

Magnetic Stimulation Allows Focal Activation of the Mouse Cochlea

Cochlear implants (CIs) strive to restore hearing to those with severe to profound hearing loss by artificially stimulating the auditory nerve. While most CI users can understand speech in a quiet environment, hearing that utilizes complex neural coding (e.g., appreciating music) has proved elusive, probably because of the inability of CIs to create narrow regions of spectral activation. Several novel approaches have recently shown promise for improving spatial selectivity, but substantial design differences from conventional CIs will necessitate much additional safety testing before clinical viability is established. Outside the cochlea, magnetic stimulation from small coils (micro-coils) has been shown to confine activation more narrowly than that from conventional micro-electrodes, raising the possibility that coil-based stimulation of the cochlea could improve the spectral resolution of CIs. To explore this, we delivered magnetic stimulation from micro-coils to multiple locations of the cochlea and measured the spread of activation utilizing a multi-electrode array inserted into the inferior colliculus; responses to magnetic stimulation were compared to analogous experiments with conventional micro-electrodes as well as to the responses to auditory monotones. Encouragingly, the extent of activation with micro-coils was ~60% narrower than that from electric stimulation and largely similar to the spread arising from acoustic stimulation. The dynamic range of coils was more than three times larger than that of electrodes, further supporting a smaller spread of activation. While much additional testing is required, these results support the notion that coil-based CIs can produce a larger number of independent spectral channels and may therefore improve functional performance. Further, because coil-based devices are structurally similar to existing CIs, fewer impediments to clinical translational are likely to arise.

Multi-scale 3D-convolutional neural network for hyperspectral image classification

Deep Learning methods are state-of-the-art approaches for pixel-based hyperspectral images (HSI) classification. High classification accuracy has been achieved by extracting deep features from both spatial-spectral channels. However, the efficiency of such spatial-spectral approaches depends on the spatial dimension of each patch and there is no theoretically valid approach to find the optimum spatial dimension to be considered. It is more valid to extract spatial features by considering varying neighborhood scales in spatial dimensions. In this regard, this article proposes a deep convolutional neural network (CNN) model wherein three different multi-scale spatial-spectral patches are used to extract the features in both the spatial and spectral channels. In order to extract these potential features, the proposed deep learning architecture takes three patches various scales in spatial dimension. 3D convolution is performed on each selected patch and the process runs through entire image. The proposed is named as multi-scale three-dimensional convolutional neural network (MS-3DCNN). The efficiency of the proposed model is being verified through the experimental studies on three publicly available benchmark datasets including Pavia University, Indian Pines, and Salinas. It is empirically proved that the classification accuracy of the proposed model is improved when compared with the remaining state-of-the-art methods.

Joint processing of images in two spectral channels for small objects detecting

The article is devoted to the problem of detecting low contrast small-sized objects in two-color images with a powerful spatially non-stationary background. An increase of the detecting reliability is achieved through a combination of three factors: attenuation of the background based on the construction of its locally stationary model; improving the estimation of model parameters by excluding statistically significant outliers from the initial data; joint processing of two-color images with a weakened background component. A method of constructing a linear boundary for detecting a useful signal in a two-dimensional space is proposed. The performance characteristics of a two-channel detector of small-sized objects are presented.

Deriving column-integrated thermospheric temperature with the N₂ Lyman–Birge–Hopfield (2,0) band

This paper presents a new technique to derive thermospheric temperature from space-based disk observations of far ultraviolet airglow. The technique, guided by findings from principal component analysis of synthetic daytime Lyman–Birge–Hopfield (LBH) disk emissions, uses a ratio of the emissions in two spectral channels that together span the LBH (2,0) band to determine the change in band shape with respect to a change in the rotational temperature of N2. The two-channel-ratio approach limits representativeness and measurement error by only requiring measurement of the relative magnitudes between two spectral channels and not radiometrically calibrated intensities, simplifying the forward model from a full radiative transfer model to a vibrational–rotational band model. It is shown that the derived temperature should be interpreted as a column-integrated property as opposed to a temperature at a specified altitude without utilization of a priori information of the thermospheric temperature profile. The two-channel-ratio approach is demonstrated using NASA GOLD Level 1C disk emission data for the period of 2–8 November 2018 during which a moderate geomagnetic storm has occurred. Due to the lack of independent thermospheric temperature observations, the efficacy of the approach is validated through comparisons of the column-integrated temperature derived from GOLD Level 1C data with the GOLD Level 2 temperature product as well as temperatures from first principle and empirical models. The storm-time thermospheric response manifested in the column-integrated temperature is also shown to corroborate well with hemispherically integrated Joule heating rates, ESA SWARM mass density at 460 km, and GOLD Level 2 column O/N2 ratio.

Improving the Analysis of DNA Sanger Sequencing Results: SeqBase Computer Program

Введение. Программное обеспечение, предоставляемое производителями автоматических генетических анализаторов, в большинстве случаев позволяет провести адекватный анализ результатов секвенирования ДНК по Сэнгеру для матриц с составом нуклеотидов, близким к эквивалентному. Однако для рассмотрения результатов секвенирования матриц, отличающихся неэквивалентным нуклеотидным составом, требуется проводить анализ электрофореграмм с сохранением информации об интенсивности сигналов флуоресценции. В особенности это касается секвенирования ДНК, модифицированной бисульфитом натрия. Цель: разработать и апробировать в практике научных исследований компьютерную программу для обеспечения адекватного анализа электрофореграмм секвенирования ДНК по Сэнгеру на основе бережного отношения к первичным данным и аккуратного определения базовых линий в спектральных каналах отдельных нуклеотидов. Методы. Программа SeqBase написана на языке C#, программная платформа .NET Framework 4.0, и выполняется в среде исполнения CLR (Common Language Runtime) для операционных систем семейства Windows. Адрес установочного пакета программы SeqBase: http://www.epigenetic.ru/projects/seqbase. Результаты. Разработана компьютерная программа, предназначенная для анализа первичных результатов секвенирования по Сэнгеру (хроматограмм капиллярного электрофореза), полученных на автоматических генетических анализаторах и представленных в файлах формата ABIF (*.ab1), обеспечивающая следующие возможности: 1) просмотр исходных электрофореграмм как в общем виде, так и раздельно по спектральным каналам; 2) кадрирование области анализа; 3) сглаживание сигналов; 4) ручная установка базовой линии по каждому из спектральных каналов; 5) сведение базовых линий по всем каналам; 6) ручная коррекция подвижности фрагментов ДНК в зависимости от типа флуоресцентной метки терминирующего нуклеотида. Апробация программы успешно проведена в рамках ряда исследований, результаты которых опубликованы в рецензируемых научных изданиях. Заключение. Использование программы SeqBase целесообразно для анализа результатов секвенирования по Сэнгеру матриц ДНК с неэквивалентным нуклеотидным составом, в особенности, модифицированных бисульфитом натрия, во избежание получения ложных результатов и для уточнения количественных оценок. Background. The software provided by the manufacturers of automatic genetic analyzers, in most cases, allows an adequate analysis of the results of Sanger DNA sequencing for templates with a nucleotide composition close to the equivalent. However, to consider the results of sequencing of templates with non-equivalent nucleotide composition, it is necessary to analyze electrophoregrams with preservation of primary information on the intensity of fluorescence signals. This is especially important for the sequencing of DNA modified with sodium bisulfite. Aim: to develop and validate in the practice of scientific research a computer program that ensures adequate analysis of electrophoregrams of Sanger DNA sequencing based on preservation of the primary data and on accurate determination of baselines in the spectral channels of individual nucleotides. Methods. The SeqBase program is written in C#, the programming platform .NET Framework 4.0, and runs in the CLR (Common Language Runtime) for Windows operating systems. SeqBase installation package address is http://www.epigenetic.ru/projects/seqbase. Results. A computer program has been developed designed to analyze the primary results of Sanger sequencing (chromatograms of capillary electrophoresis) obtained from automatic genetic analyzers and presented in files of the ABIF (*.ab1) format, which provides the following functions: 1) viewing the original electrophoregrams both in general form and separately by spectral channels; 2) cropping the area of analysis; 3) signal smoothing; 4) manual setting of the baseline for each of the spectral channels; 5) convergence of baselines on all channels; 6) manual correction of the mobility of DNA fragments depending on the type of fluorescent label of the terminating nucleotide. The program has been successfully tested in a number of studies, the results of which have been published in peer-reviewed scientific journals. Conclusion. The use of the SeqBase program is advisable for the analysis of the results of Sanger sequencing of DNA templates with non-equivalent nucleotide composition, especially those modified with sodium bisulfite, to avoid false results and to clarify quantitative estimates.

The Martian environment observed by NOMAD on ExoMars Trace Gas Orbiter

<p>The NOMAD (“Nadir and Occultation for MArs Discovery”) spectrometer suite on board the ExoMars Trace Gas Orbiter has been designed to investigate the composition of Mars' atmosphere, with a particular focus on trace gases, clouds and dust. The instrument probes the ultraviolet and infrared regions covering large parts of the 0.2-4.3 µm spectral range [1,2], with 3 spectral channels: a solar occultation channel (SO – Solar Occultation; 2.3–4.3 μm), a second infrared channel capable of nadir, solar occultation, and limb sounding (LNO – Limb Nadir and solar Occultation; 2.3–3.8 μm), and an ultraviolet/visible channel (UVIS – Ultraviolet and Visible Spectrometer, 200–650 nm). Since its arrival at Mars in April 2018, NOMAD performed solar occultation, nadir and limb observations dedicated to the determination of the composition and structure of the atmosphere.</p><p>NOMAD has been accumulating data about the Martian atmosphere and its surface since its insertion. We will present some results covering the atmosphere composition including clouds and dust, climatologies of water, carbon monoxide and ozone. We also report on the different discoveries highlighted by the instrument by pointing to a series of contributions to this conference that will present in detail several specific studies, like recent progress in the instrument calibration, the latest CO2 and temperature vertical profiles, studies of aerosol nature and distribution, water vapor profiles and variability, carbon monoxide vertical distribution, dayglow observations; detection of HCl, its vertical profiles and in general advances in the analysis of the spectra recorded by the three channels of NOMAD.</p><p>References</p><p>[1] Vandaele, A.C., et al., 2015. Planet. Space Sci. 119, 233-249.</p><p>[2] Vandaele et al., 2018. Space Sci. Rev., 214:80, doi.org/10.1007/s11214-11018-10517-11212.</p><p> </p>