Subretinal electronic chips allow blind patients to read letters and combine them to words

A light-sensitive, externally powered microchip was surgically implanted subretinally near the macular region of volunteers blind from hereditary retinal dystrophy. The implant contains an array of 1500 active microphotodiodes ('chip'), each with its own amplifier and local stimulation electrode. At the implant's tip, another array of 16 wire-connected electrodes allows light-independent direct stimulation and testing of the neuron-electrode interface. Visual scenes are projected naturally through the eye's lens onto the chip under the transparent retina. The chip generates a corresponding pattern of 38 × 40 pixels, each releasing light-intensity-dependent electric stimulation pulses. Subsequently, three previously blind persons could locate bright objects on a dark table, two of whom could discern grating patterns. One of these patients was able to correctly describe and name objects like a fork or knife on a table, geometric patterns, different kinds of fruit and discern shades of grey with only 15 per cent contrast. Without a training period, the regained visual functions enabled him to localize and approach persons in a room freely and to read large letters as complete words after several years of blindness. These results demonstrate for the first time that subretinal micro-electrode arrays with 1500 photodiodes can create detailed meaningful visual perception in previously blind individuals.     

Properties of the interaction of Arf-like protein 2 with PDEdelta

Arf-like proteins (Arl) share certain characteristic features with the Arf subfamily of Ras superfamily proteins, but their function is unknown. Here, we show by a variety of spectroscopic techniques that Arl2, unlike most other Ras-related proteins, has micromolar rather than picomolar affinity for nucleotides. As a consequence of low affinity, nucleotide dissociation rates are rather fast, arguing that it is not regulated by guanine nucleotide exchange factors. Arl2 is isolated as prey in a yeast double hybrid screen using phosphodiesterase 6delta (PDEdelta) as bait. This interaction is dependent on GTP, and the binding of PDEdelta substantially stabilizes GTP binding, increasing affinity and decreasing dissociation rates by a similar factor. Among all Arl proteins tested, PDEdelta only interacted with the closely related proteins Arl2 and Arl3, strongly suggesting that Arl2/3 are specific regulators of PDEdelta.     

Cell‐specific differences in the processing of the R14W CAIV mutant associated with retinitis pigmentosa 17

Retinitis pigmentosa is a highly heterogeneous form of inherited blindness which affects more than 1.3 million individuals worldwide. The RP17 form of the disease is caused by an arginine to tryptophan (R14W) mutation in the signal sequence of carbonic anhydrase IV (CAIV). While CAIV is expressed in the choriocapillaries of the eye and renal epithelium, the R14W mutation results in an exclusively ocular phenotype in affected individuals. In order to investigate the mechanism of disease in RP17 and the lack of kidney phenotype, we compared the subcellular localization and post‐translational processing of wild‐type (WT)‐ and mutant‐CAIV in three cell types. We show using immunocytochemistry that unlike WT CAIV which is transported to the plasma membrane of transfected COS‐7 and HT‐1080 cells, the R14W mutant CAIV is retained in the endoplasmic reticulum. Western blot analyses further reveal that whereas the WT CAIV is processed to its mature form in both these cell lines, significant levels of the R14W mutant protein remain in its immature form. Importantly, flow cytometry experiments demonstrate that compared to WT CAIV protein, expression of specifically the R14W CAIV results in an S and G2/M cell‐cycle block, followed by apoptosis. Interestingly, when the above experiments were repeated in the human embryonic kidney cell line, HEK‐293, strikingly different results were obtained. These cells were unaffected by the expression of the R14W mutant CAIV and were able to process the mutant and WT protein equally effectively. This study has important implications for our understanding of the RP17 phenotype. J. Cell. Biochem. 111: 735–741, 2010. © 2010 Wiley‐Liss, Inc.     

Artificial selection for food colour preferences

Colour is an important factor in food detection and acquisition by animals using visually based foraging. Colour can be used to identify the suitability of a food source or improve the efficiency of food detection, and can even be linked to mate choice. Food colour preferences are known to exist, but whether these preferences are heritable and how these preferences evolve is unknown. Using the freshwater fish Poecilia reticulata, we artificially selected for chase behaviour towards two different-coloured moving stimuli: red and blue spots. A response to selection was only seen for chase behaviours towards the red, with realized heritabilities ranging from 0.25 to 0.30. Despite intense selection, no significant chase response was recorded for the blue-selected lines. This lack of response may be due to the motion-detection mechanism in the guppy visual system and may have novel implications for the evolvability of responses to colour-related signals. The behavioural response to several colours after five generations of selection suggests that the colour opponency system of the fish may regulate the response to selection.     

Elders with implant overdentures: a 22-year clinical report

doi: 10.1111/j.1741‐2358.2012.00628.x Elders with implant overdentures: a 22‐year clinical report Objective: To report on the long‐term survival and prosthodontic maintenance of two edentulous adults with mandibular overdentures supported by hydroxyapatite (HA)‐coated implants. Background: Mandibular implant overdentures are a successful treatment option with positive impact on the quality of life of elderly edentulous adults. Long‐term survival of the implants requires continued rigorous prosthodontic maintenance. Clinical report: Two elderly edentulous adults with mandibular overdentures supported by 2 HA‐coated implants were presented for prosthodontic rehabilitation after 22 years of placement. The implants were osseo‐integrated and surviving at presentation based on accepted criteria. The mandibular implant overdentures suffered recurrent loss of retention and stability. Prosthodontic treatment involving the replacement of defective attachment systems and construction of new sets of mandibular implant overdentures opposing complete maxillary dentures is presented. Conclusion: The long‐term survival of mandibular 2‐implant overdentures requires continued prosthodontic maintenance. A conservative approach in the rehabilitation of two older edentulous adults with mandibular 2‐implant overdentures was described including proper selection of attachment systems.     

Exhaled breath volatile alterations in pregnancy assessed with electronic nose

Context: Pregnancy-linked accelerated metabolism and oxidative stress may alter the exhaled volatile compound pattern (“breathprint”). Electronic noses can distinguish “breathprints” associated with different disorders.

Objective: This is the first study assessing alterations in “breathprint” during gestation.

Material and methods: 130 women participated in our study (78 pregnant vs. 52 non-pregnant). Breath samples were processed by an electronic nose and analyzed using principal component analysis.

Results: Significant differences were found in exhaled breath pattern between pregnant and non-pregnant women (p?=?0.001).

Conclusion: Pregnancy-induced changes in exhaled gases need to be considered when pregnant women with respiratory disorders carry out breath tests.     

Automating analysis of vegetation with computer vision: Cover estimates and classification

This study develops an approach to automating the process of vegetation cover estimates using computer vision and pattern recognition algorithms. Visual cover estimation is a key tool for many ecological studies, yet quadrat‐based analyses are known to suffer from issues of consistency between people as well as across sites (spatially) and time (temporally). Previous efforts to estimate cover from photograps require considerable manual work. We demonstrate that an automated system can be used to estimate vegetation cover and the type of vegetation cover present using top–down photographs of 1 m by 1 m quadrats. Vegetation cover is estimated by modelling the distribution of color using a multivariate Gaussian. The type of vegetation cover is then classified, using illumination robust local binary pattern features, into two broad groups: graminoids (grasses) and forbs. This system is evaluated on two datasets from the globally distributed experiment, the Nutrient Network (NutNet). These NutNet sites were selected for analyses because repeat photographs were taken over time and these sites are representative of very different grassland ecosystems—a low stature subalpine grassland in an alpine region of Australia and a higher stature and more productive lowland grassland in the Pacific Northwest of the USA. We find that estimates of treatment effects on grass and forb cover did not differ between field and automated estimates for eight of nine experimental treatments. Conclusions about total vegetation cover did not correspond quite as strongly, particularly at the more productive site. A limitation with this automated system is that the total vegetation cover is given as a percentage of pixels considered to contain vegetation, but ecologists can distinguish species with overlapping coverage and thus can estimate total coverage to exceed 100%. Automated approaches such as this offer techniques for estimating vegetation cover that are repeatable, cheaper to use, and likely more reliable for quantifying changes in vegetation over the long‐term. These approaches would also enable ecologists to increase the spatial and temporal depth of their coverage estimates with methods that allow for vegetation sampling over large spatial scales quickly.     

An Improved Artificial Immune Algorithm with a Dynamic Threshold

An improved artificial immune algorithm with a dynamic threshold is presented. The calculation for the affinity function in the real-valued coding artificial immune algorithm is modified through considering the antibody＇s fitness and setting the dynamic threshold value. Numerical experiments show that compared with the genetic algorithm and the originally real-valued coding artificial immune algorithm, the improved algorithm possesses high speed of convergence and good performance for preventing premature convergence.     

Molecular genetics of retinal degeneration: A Drosophila perspective

Inherited retinal degeneration in Drosophila has been explored for insights into similar processes in humans. Based on the mechanisms, I divide these mutations in Drosophila into three classes. The first consists of genes that control the specialization of photoreceptor cells including the morphogenesis of visual organelles (rhabdomeres) that house the visual signaling proteins. The second class contains genes that regulate the activity or level of the major rhodopsin, Rh1, which is the light sensor and also provides a structural role for the maintenance of rhabdomeres. Some mutations in Rh1 (NinaE) are dominant due to constitutive activity or folding defects, like autosomal dominant retinitis pigmentosa (ADRP) in humans. The third class consists of genes that control the Ca²⁺ influx directly or indirectly by promoting the turnover of the second messenger and regeneration of PIP₂, or mediate the Ca²⁺-dependent regulation of the visual response. These gene products are critical for the increase in cytosolic Ca²⁺ following light stimulation to initiate negative regulatory events. Here I will focus on the signaling mechanisms underlying the degeneration in norpA, and in ADRP-type NinaE mutants that produce misfolded Rh1. Accumulation of misfolded Rh1 in the ER triggers the unfolded protein response (UPR), while endosomal accumulation of activated Rh1 may initiate autophagy in norpA. Both autophagy and the UPR are beneficial for relieving defective endosomal trafficking and the ER stress, respectively. However, when photoreceptors fail to cope with the persistence of these stresses, a cell death program is activated leading to retinal degeneration.     

不同品种烟草花粉电子显微镜观察

通过对10个烤烟品种、8个晒烟品种、2个野生种的花粉进行扫描电子显微镜观察,发现同为烤烟或晒烟的烟草,其花粉的形态、大小、外壁纹饰比较稳定。野生烟在供试种中具有独特的细网状外壁纹饰,是鉴别野生烟与非野生烟的一条有效途径。     

Amacrine cells with neurotensin- and somatostatin-like immunoreactivities in three species of teleosts with different color vision

Summary Neurotensin- and somatostatin-like immunoreactivities were localized by pre-embedding techniques in retinal whole-mounts and radial sections of a monochromatic glass catfish (Kryptopterus bicirrhis), a dichromatic cichlid species (Aequidens pulcher), and the tetrachromatic roach (Rutilus rutilus). Both neuropeptides were observed in perikarya and processes of amacrine cells. For a precise identification of cell types, tangential and radial views were correlated with Golgiimpregnated material.The dendritic pattern defining the morphological subtype of amacrine cells was determined by the given neuropeptide or by the species-specific degree of complexity of retinal structure and function. Neurotensin-like immunoreactivity was localized in amacrine cells of intermediate size, radial symmetry and dendrites with numerous varicosities; they were monostratified in sublayer 3 of the inner plexiform layer. This cell type was common to all three species. In the mono and dichromatic retinas, a single type of amacrine cell with somatostatinlike immunoreactivity was found with radially oriented, varicose dendrites in sublayer 5. In the tetrachromatic roach retina, two somatostatin-positive amacrine cell types were found with very different patterns of ramification; furthermore, both of these types occurred in more than one sublayer.Possible functional implications for color vision of neuropeptide-specific amacrine cells with uniform morphology in all three species and those with a more varied morphology in the tetrachromatic roach are discussed.Dedicated to Prof. A. Oksche on the occasion of his 60th birthday     

An ensemble learning integration of multiple CNN with improved vision transformer models for pest classification

Pests are the main threats to crop growth, and the precision classification of pests is conducive to formulating effective prevention and governance strategies. In response to the problems of low efficiency and inadaptability to the large-scale environment of existing pest classification methods, this paper proposes a new pest classification method based on a convolutional neural network (CNN) and an improved Vision Transformer model. First, the MMAlNet is designed to extract the characteristics of the identification object from different scales and finer granularity. Then, a classification model called DenseNet Vision Transformer (DNVT) combining a CNN and an improved vision transformer model is proposed. The proposed DNVT captures both long distance dependencies and local characteristic modelling capabilities, which can effectively improve pest classification accuracy. Finally, the ensemble learning algorithm is used to learn MMAlNet and DNVT classification forecasts for soft voting, further enhancing the classification accuracy of pests. The simulation experiment results on the D0 and IP102 datasets show that the proposed method attained a maximum classification of 99.89 and 74.20%, respectively, which is better than other state-of-the-art methods and has a high practical application value.     

Human Artificial Chromosome with a Conditional Centromere for Gene Delivery and Gene Expression

Human artificial chromosomes (HACs), which carry a fully functional centromere and are maintained as a single-copy episome, are not associated with random mutagenesis and offer greater control over expression of ectopic genes on the HAC. Recently, we generated a HAC with a conditional centromere, which includes the tetracycline operator (tet-O) sequence embedded in the alphoid DNA array. This conditional centromere can be inactivated, loss of the alphoid^tet-O (tet-O HAC) by expression of tet-repressor fusion proteins. In this report, we describe adaptation of the tet-O HAC vector for gene delivery and gene expression in human cells. A loxP cassette was inserted into the tet-O HAC by homologous recombination in chicken DT40 cells following a microcell-mediated chromosome transfer (MMCT). The tet-O HAC with the loxP cassette was then transferred into Chinese hamster ovary cells, and EGFP transgene was efficiently and accurately incorporated into the tet-O HAC vector. The EGFP transgene was stably expressed in human cells after transfer via MMCT. Because the transgenes inserted on the tet-O HAC can be eliminated from cells by HAC loss due to centromere inactivation, this HAC vector system provides important novel features and has potential applications for gene expression studies and gene therapy.     

Current density in a model of a human body with a conductive implant exposed to ELF electric and magnetic fields

A numerical model of a human body with an intramedullary nail in the femur was built to evaluate the effects of the implant on the current density distribution in extremely low frequency electric and magnetic fields. The intramedullary nail was chosen because it is one of the longest high conductive implants used in the human body. As such it is expected to alter the electric and magnetic fields significantly. The exposure was a simultaneous combination of inferior to superior electric field and posterior to anterior magnetic field both alternating at 50 Hz with the values corresponding to the ICNIRP reference levels: 5000 V m^?1 for electric field and 100 µT for magnetic flux density. The calculated current density distribution inside the model was compared to the ICNIRP basic restrictions for general public (2 mA m^?2). The results show that the implant significantly increases the current density up to 9.5 mA m^?2 in the region where it is in contact with soft tissue in the model with the implant in comparison to 0.9 mA m^?2 in the model without the implant. As demonstrated the ICNIRP basic restrictions are exceeded in a limited volume of the tissue in spite of the compliance with the ICNIRP reference levels for general public, meaning that the existing safety limits do not necessarily protect implanted persons to the same extent as they protect people without implants. Bioelectromagnetics 30:591–599, 2009. © 2009 Wiley‐Liss, Inc.     

Monitoring the aroma production during wine-must fermentation with an electronic nose.

This work discusses the feasibility of using the electronic nose for the on-line and real-time monitoring of the production of a complex aroma profile during a bioconversion process. As a case study, the formation of the muscatel aroma during the wine-must fermentation was selected. During wine-must fermentation, aroma compounds responsible for the organoleptic character are produced in the ppm range, while simultaneously one of the main metabolic products, ethanol, is produced in much higher quantities (up to 10% wt). Because the sensors of the electronic nose array are cross-selective to different volatile compounds, it was investigated in detail how far the electronic nose was able to evaluate the aroma profile along the fermentation. This article discusses and evaluates subsequently the integration of a membrane separation process-organophilic pervaporation-for selectively enriching aroma compounds relative to ethanol, to improve sample discrimination.     

Palatal implant surgery effectiveness in treatment of obstructive sleep apnea: A numerical method with 3D patient-specific geometries

Obstructive sleep apnea (OSA) affects a large percentage of the population and is increasingly recognized as a major global health problem. One surgical procedure for OSA is to implant polyethylene (PET) material into the soft palate, but its efficacy remains to be discussed. In this study, we provide input to this topic based on numerical simulations. Three 3 dimensional (3D) soft palate finite element models including mouth-close and mouth-open cases were created based on three patient-specific computed tomography (CT) images. A simplified material modeling approach with the Neo-Hookean material model was applied, and nonlinear geometry was accounted for. Young’s modulus for the implant material was obtained from uniaxial tests, and the PET implant pillars were inserted to the 3D soft palate model. With the finite element model, we designed different surgical schemes and investigated their efficacy with respect to avoiding the soft palate collapse. Several pillar schemes were tested, including different placement directions, different placement positions, different settings for the radius and the array parameters of the implant pillars, and different Young’s moduli for the pillars. Based on our simulation results, the longitudinal-direction implant surgery improved the stiffness of the soft palate to a small degree, and implanting in the transverse direction was evaluated to be a good choice for improving the existing surgical scheme. In addition, the Young’s modulus of the polyethylene material implants has an influence on the reinforcement efficacy of the soft palate.     

Detection of pest species with different ratios in tea plant based on electronic nose

It is highly possible that tea (Camellia sinensis) plant is attacked by more than one pest species at the same time, and the determination of their proportion is of great significance to the management of tea plants. However, there are no literatures focusing on it previously. In this work, two pest species (Ectropis obliqua and Ectropis grisescens) in six different ratios (10:0, 8:2, 6:4, 4:6, 2:8 and 0:10) were applied to attack tea plants and electronic nose (E‐nose) was employed to detect them, labelled as group 10:0, 8:2, 6:4, 4:6, 2:8 and 0:10, respectively. Two prediction methods were applied to predict the ratio of E. obliqua and E. grisescens attacking tea plant and their performances were compared. The first method employed regression algorithm for prediction analysis based on the whole E‐nose data directly. The second method classified tea plants into three main classes (the first class contained group 10:0, the second class contained groups 8:2, 6:4, 4:6 and 2:8, and the third class contained group 0:10) first, then regression algorithm was applied to deal with the second class for prediction analysis. The results showed that the second method had a better performance. Its discrimination results showed 100% of the correct classification rate for training set and 93.75% for testing set. Meanwhile, its prediction results showed 0.0005 of root mean square error (RMSE) for calibration set, 0.0064 for validation set and 99.07% of fitting correlation coefficients (R²) for calibration set, 91.22% for validation set, which were acceptable for prediction analysis and proved that E‐nose was a feasible technique for pests' ratio prediction.     

Pulling the covers in electronic health records for an association study with self-reported sleep behaviors

ABSTRACT

The electronic health record (EHR) contains rich histories of clinical care, but has not traditionally been mined for information related to sleep habits. Here, we performed a retrospective EHR study based on a cohort of 3,652 individuals with self-reported sleep behaviors documented from visits to the sleep clinic. These individuals were obese (mean body mass index 33.6 kg/m²) and had a high prevalence of sleep apnea (60.5%), however we found sleep behaviors largely concordant with prior prospective cohort studies. In our cohort, average wake time was 1 hour later and average sleep duration was 40 minutes longer on weekends than on weekdays (p < 10^?12). Sleep duration varied considerably as a function of age and tended to be longer in females and in whites. Additionally, through phenome-wide association analyses, we found an association of long weekend sleep with depression, and an unexpectedly large number of associations of long weekday sleep with mental health and neurological disorders (q < 0.05). We then sought to replicate previously published genetic associations with morning/evening preference on a subset of our cohort with extant genotyping data (n = 555). While those findings did not replicate in our cohort, a polymorphism (rs3754214) in high linkage disequilibrium with a previously published polymorphism near TARS2 was associated with long sleep duration (p < 0.01). Collectively, our results highlight the potential of the EHR for uncovering the correlates of human sleep in real-world populations.     

Analysis of colour vision with the Ishihara test: A comparison between two groups of subjects with different age range

In the present study, we have described and compared both the number and the types of the mistakes that were made during reading of the Ishihara plates by 3,926 students attending the secondary schools in the province of Cosenza (Calabria, Southern Italy) and by 546 Calabrian university students all without colour-blindness. There were no qualitative differences in the types of mistakes made by the two groups of subjects during their reading of the Ishihara plates. Moreover, we have reported both the mean frequencies and types of colour-blindness in only the province of Cosenza. During this study, it was shown that the ishihara test is reliable during screenings for the diagnosis of colour vision deficiencies, as shown by some previous investigations.