Repeating Spatial-Temporal Motifs of CA3 Activity Dependent on Engineered Inputs from Dentate Gyrus Neurons in Live Hippocampal Networks.

Anatomical and behavioral studies, and in vivo and slice electrophysiology of the hippocampus suggest specific functions of the dentate gyrus (DG) and the CA3 subregions, but the underlying activity dynamics and repeatability of information processing remains poorly understood. To approach this problem, we engineered separate living networks of the DG and CA3 neurons that develop connections through 51 tunnels for axonal communication. Growing these networks on top of an electrode array enabled us to determine whether the subregion dynamics were separable and repeatable. We found spontaneous development of polarized propagation of 80% of the activity in the native direction from DG to CA3 and different spike and burst dynamics for these subregions. Spatial-temporal differences emerged when the relationships of target CA3 activity were categorized with to the number and timing of inputs from the apposing network. Compared to times of CA3 activity when there was no recorded tunnel input, DG input led to CA3 activity bursts that were 7× more frequent, increased in amplitude and extended in temporal envelope. Logistic regression indicated that a high number of tunnel inputs predict CA3 activity with 90% sensitivity and 70% specificity. Compared to no tunnel input, patterns of >80% tunnel inputs from DG specified different patterns of first-to-fire neurons in the CA3 target well. Clustering dendrograms revealed repeating motifs of three or more patterns at up to 17 sites in CA3 that were importantly associated with specific spatial-temporal patterns of tunnel activity. The number of these motifs recorded in 3 min was significantly higher than shuffled spike activity and not seen above chance in control networks in which CA3 was apposed to CA3 or DG to DG. Together, these results demonstrate spontaneous input-dependent repeatable coding of distributed activity in CA3 networks driven by engineered inputs from DG networks. These functional configurations at measured times of activation (motifs) emerge from anatomically accurate feed-forward connections from DG through tunnels to CA3

Evidence of microbial activity from a shallow water whale fall (Voghera, northern Italy)

The fossil bones, associated carbonate cements and enclosing concretion of a Miocene mysticete from inner shelf deposits (Monte Vallassa Formation, northern Italy) were analyzed for evidence of microbial activity. Optical and scanning electron microscopy, Raman spectroscopy, and stable C and O isotope geochemistry were used for high spatial resolution microfacies and biosedimentological analyses. Whale cancellous bones were filled by different carbonate cements including microcrystalline dolomite, rhombohedral dolomite and sparry calcite. Biofabric and biominerals such as microbial peloids, clotted textures and pyrite framboids were associated with the dolomite cements. Dolomite inside cancellous bones and in the enclosing concretion showed similar isotopic values (avg δ 13C: -7.12‰; avg δ 18O: +3.81‰), depleted with respect to the (late) sparry calcite cement (avg δ 13C: -0.55‰; avg δ 18O: -0.98‰). Microcrystalline barite (BaSO 4) was observed on the external surface of the bones. In addition, two different types of microborings were recognized, distinguished by their size and morphology and were ascribed respectively to prokaryote and fungal trace makers. Our results testify for the development of a diverse microbial ecosystem during the decay of a shallow water whale carcass, which could be detected in the fossil record. However, none of the observed biosignatures (e.g., microbial peloids, clotted textures) can be used alone as a positive fossil evidence of the general development of a sulfophilic stage of whale fall ecological succession. The occurrence of the hard parts of chemosynthetic invertebrates associated with fossil whale bones is still the more convincing proof of the development of a sulfide-base chemoautotrophic ecosystem. © 2011 Elsevier B.V

Feed-Forward Propagation of Temporal and Rate Information between Cortical Populations during Coherent Activation in Engineered In Vitro Networks.

Transient propagation of information across neuronal assembles is thought to underlie many cognitive processes. However, the nature of the neural code that is embedded within these transmissions remains uncertain. Much of our understanding of how information is transmitted among these assemblies has been derived from computational models. While these models have been instrumental in understanding these processes they often make simplifying assumptions about the biophysical properties of neurons that may influence the nature and properties expressed. To address this issue we created an in vitro analog of a feed-forward network composed of two small populations (also referred to as assemblies or layers) of living dissociated rat cortical neurons. The populations were separated by, and communicated through, a microelectromechanical systems (MEMS) device containing a strip of microscale tunnels. Delayed culturing of one population in the first layer followed by the second a few days later induced the unidirectional growth of axons through the microtunnels resulting in a primarily feed-forward communication between these two small neural populations. In this study we systematically manipulated the number of tunnels that connected each layer and hence, the number of axons providing communication between those populations. We then assess the effect of reducing the number of tunnels has upon the properties of between-layer communication capacity and fidelity of neural transmission among spike trains transmitted across and within layers. We show evidence based on Victor-Purpura's and van Rossum's spike train similarity metrics supporting the presence of both rate and temporal information embedded within these transmissions whose fidelity increased during communication both between and within layers when the number of tunnels are increased. We also provide evidence reinforcing the role of synchronized activity upon transmission fidelity during the spontaneous synchronized network burst events that propagated between layers and highlight the potential applications of these MEMs devices as a tool for further investigation of structure and functional dynamics among neural populations

Rationale of the purpose of using accelerated measurement method of particulate matters with locomotive exhaust gases

Проаналізовано проблему зростання тривалості і вартості регламентованої процедури екологічного діагностування дизельних силових установок, яка виникла з введенням нової нормованої величини – середньоексплуатаційного викиду твердих частинок з відпрацьованими газами дизелів. Запропоновано спосіб прискореного виміру масових викидів твердих частинок, який відповідає вимогам міжнародного стандарту ISO 8178. Впровадження цього способу дозволяє підвищити економічну ефективність екологічних випробувань дизелів. Розроблено методику оцінки ефективності використання запропонованого способу за критеріями: тривалості, витрат палива та вартості випробувань. На прикладі тепловозних дизелів експериментально обгрунтовано доцільність використання даного способу в ході екологічних випробувань дизельних силових установок великої потужності.Has been analyzed the problem of increasing the duration and cost of the regulated procedure for ecological diagnostics of diesel power plants during the measurement of particulate emissions compared with gaseous pollutants: nitrogen oxides, carbon monoxide and hydrocarbons, which appeared with the introduction of a new normalized value – the average operating emission of solid particles with exhaust gases of diesel engines. The accelerated measurement method of mass emissions of particulate matters, which meets the requirements of the international standard ISO 8178 is proposed. Implementation of this method allows to increase the economic efficiency of ecological testing of diesel engines by increasing the rate of filtration of the sample to the maximum allowable value and collecting the minimum permissible mass of particulate matters on the filters. The method of estimation of efficiency of using the proposed method according to the criteria of duration, fuel consumption and cost of tests is developed. The expediency of the use of this method in the course of ecological testing of locomotive diesel engines has been proved experimentally

Impact of Different Mulching Materials on the Growth and Yield of tomato (Solanum lycopersicum) in Dehradun region of Uttarakhand

Field trials were carried out in 2013-2014 cropping seasons to assess the impact of different mulching materials on the growth and yield of tomato (Solanum lycopersicum) in Dehradun (Uttarakhand) region of India. The crop growth and fruit yield were studied for two cultivars namely Cherry Tomato and Marglobe under two inorganic mulches (black polythene, white polythene) and four organic mulches (FYM, rice straw, dry leaves, sugarcane trash) and compared with unweeded control. Four competitive plants were randomly selected from each treatment to record data on various parameters. The experiment comprising these treatments was laid out as factorial randomized block design with three replications. It was observed that among all the treatments black polythene mulch showed significantly higher plant height (89.92 cm, 59.17 cm) and (97.17 cm, 63.42 cm) after 30 and 45 days respectively, number of trusses per plant (109 and 6.33), number of fruits per truss (14.50 and 6.42) and weight of immature and mature fruits (4.59 gm and 6.73 gm) and (42.08 gm and 54.25 gm) in Cherry Tomato and Marglobe varieties. Among all the treatments, black polythene mulch was found to be the best for tomato cultivation in Dehradun (Uttarakhand) region of India

Authigenic Mineral Texture in Submarine 1979 Basalt Drill Core, Surtsey Volcano, Iceland

Micrometer-scale maps of authigenic microstructures in submarine basaltic tuff from a 1979 Surtsey volcano, Iceland, drill core acquired 15 years after eruptions terminated describe the initial alteration of oceanic basalt in a low-temperature hydrothermal system. An integrative investigative approach uses synchrotron source X-ray microdiffraction, microfluoresence, micro-computed tomography, and scanning transmission electron microscopy coupled with Raman spectroscopy to create finely resolved spatial frameworks that record a continuum of alteration in glass and olivine. Microanalytical maps of vesicular and fractured lapilli in specimens from 157.1-, 137.9-, and 102.6-m depths and borehole temperatures of 83, 93.9, and 141.3 °C measured in 1980, respectively, describe the production of nanocrystalline clay mineral, zeolites, and Al-tobermorite in diverse microenvironments. Irregular alteration fronts at 157.1-m depth resemble microchannels associated with biological activity in older basalts. By contrast, linear microstructures with little resemblance to previously described alteration features have nanocrystalline clay mineral (nontronite) and zeolite (amicite) texture. The crystallographic preferred orientation rotates around an axis parallel to the linear feature. Raman spectra indicating degraded and poorly ordered carbonaceous matter of possible biological origin are associated with nanocrystalline clay mineral in a crystallographically oriented linear microstructure in altered olivine at 102.6 m and with subcircular nanoscale cavities in altered glass at 137.9-m depth. Although evidence for biotic processes is inconclusive, the integrated analyses describe the complex organization of previously unrecognized mineral texture in very young basalt. They provide a foundational mineralogical reference for longitudinal, time-lapse characterizations of palagonitized basalt in oceanic environments

Tunnel 4 (Porto) : three-dimensional finite element analysis

Neste trabalho apresenta-se os principais resultados da aplicação de modelos de elementos finitos a um túnel superficial escavado em solos residuais graníticos, no Porto. Os cálculos foram efectuados através de análises tridimensionais, nas quais se tentou reproduzir a sequência completa da construção (fase de escavação e aplicação do suporte). O comportamento mecânico dos solos foi reproduzido usando um modelo elástico perfeitamente plástico, tendo os respectivos parâmetros definidores sido estimados com base em resultados de ensaios de campo realizados durante a prospecção e de ensaios laboratoriais. O comportamento observado é comparado com os resultados decorrentes dos cálculos numéricos, tendo-se obtido uma boa concordância.Fundação para a Ciência e a Tecnologia - Programa POCTI/ECM/2521/95 - Concepção, Projecto e Reabilitação de Túneis em Obras Viárias