1,714 research outputs found
A Novel Approach for Development and Evaluation of LiDAR Navigated Electronic Maize Seeding System Using Check Row Quality Index.
Crop geometry plays a vital role in ensuring proper plant growth and yield. Check row planting allows adequate space for weeding in both direction and allowing sunlight down to the bottom of the crop. Therefore, a light detection and ranging (LiDAR) navigated electronic seed metering system for check row planting of maize seeds was developed. The system is comprised of a LiDAR-based distance measurement unit, electronic seed metering mechanism and a wireless communication system. The electronic seed metering mechanism was evaluated in the laboratory for five different cell sizes (8.80, 9.73, 10.82, 11.90 and 12.83 mm) and linear cell speed (89.15, 99.46, 111.44, 123.41 and 133.72 mm·s-1). The research shows the optimised values for the cell size and linear speed of cell were found to be 11.90 mm and 99.46 mm·s-1 respectively. A light dependent resistor (LDR) and light emitting diode (LED)-based seed flow sensing system was developed to measure the lag time of seed flow from seed metering box to bottom of seed tube. The average lag time of seed fall was observed as 251.2 ± 5.39 ms at an optimised linear speed of cell of 99.46 mm·s-1 and forward speed of 2 km·h-1. This lag time was minimized by advancing the seed drop on the basis of forward speed of tractor, lag time and targeted position. A check row quality index (ICRQ) was developed to evaluate check row planter. While evaluating the developed system at different forward speeds (i.e., 2, 3 and 5 km·h-1), higher standard deviation (14.14%) of check row quality index was observed at forward speed of 5 km·h-1
Characterization of MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces
In this study, MHz pulse repetition rate femtosecond laser-irradiated gold-coated silicon surfaces under ambient condition were characterized by scanning electron microscopy (SEM), transmission electron microscopy (TEM), X-ray diffraction analysis (XRD), and X-ray photoelectron spectroscopy (XPS). The radiation fluence used was 0.5 J/cm2 at a pulse repetition rate of 25 MHz with 1 ms interaction time. SEM analysis of the irradiated surfaces showed self-assembled intermingled weblike nanofibrous structure in and around the laser-irradiated spots. Further TEM investigation on this nanostructure revealed that the nanofibrous structure is formed due to aggregation of Au-Si/Si nanoparticles. The XRD peaks at 32.2°, 39.7°, and 62.5° were identified as (200), (211), and (321) reflections, respectively, corresponding to gold silicide. In addition, the observed chemical shift of Au 4f and Si 2p lines in XPS spectrum of the irradiated surface illustrated the presence of gold silicide at the irradiated surface. The generation of Si/Au-Si alloy fibrous nanoparticles aggregate is explained by the nucleation and subsequent condensation of vapor in the plasma plume during irradiation and expulsion of molten material due to high plasma pressure
Discovery of Volatile Biomarkers of Parkinson’s Disease from Sebum
Parkinson's disease (PD) is a progressive, neurodegenerative disease that presents with significant motor symptoms, for which there is no diagnostic chemical test. We have serendipitously identified a hyperosmic individual, a "Super Smeller" who can detect PD by odor alone, and our early pilot studies have indicated that the odor was present in the sebum from the skin of PD subjects. Here, we have employed an unbiased approach to investigate the volatile metabolites of sebum samples obtained noninvasively from the upper back of 64 participants in total (21 controls and 43 PD subjects). Our results, validated by an independent cohort (n=31), identified a distinct volatiles-associated signature of PD, including altered levels of perillic aldehyde and eicosane, the smell of which was then described as being highly similar to the scent of PD by our "Super Smeller"
Cloxacillin versus vancomycin for presumed late-onset sepsis in the Neonatal Intensive Care Unit and the impact upon outcome of coagulase negative staphylococcal bacteremia: a retrospective cohort study
BACKGROUND: Coagulase negative staphylococcus (CONS) is the main cause of late-onset sepsis in Neonatal Intensive Care Units (NICU). Although CONS rarely causes fulminant sepsis, vancomycin is frequently used as empiric therapy. Indiscriminate use of vancomycin has been linked to the emergence of vancomycin resistant organisms. The objective of this study was to compare duration of CONS sepsis and mortality before and after implementation of a policy of selective vancomycin use and compare use of vancomycin between the 2 time periods. METHODS: A retrospective study was conducted of infants ≥4 days old, experiencing signs of sepsis with a first positive blood culture for CONS, during two 12-month periods. Late-onset sepsis was treated empirically with vancomycin and gentamicin during period 1, and cloxacillin and gentamicin during period 2. The confidence interval method was used to assess non-inferiority of the outcomes between the two study groups. RESULTS: There were 45 episodes of CONS sepsis during period 1 and 37 during period 2. Duration of sepsis was similar between periods (hazard ratio of 1.00, 95%CI: 0.64, 1.57). One death during period 2 was possibly related to CONS sepsis versus none in period 1. Vancomycin was used in 97.8% of episodes in period 1 versus 81.1% of episodes in period 2. CONCLUSION: Although we failed to show non-inferiority of duration of sepsis in the cloxacillin and gentamicin group compared to the vancomycin and gentamicin group, duration of sepsis was clinically similar. Restricting vancomycin for confirmed cases of CONS sepsis resistant to oxacillin appears effective and safe, and significantly reduces vancomycin use in the NICU
Facile Synthesis of Three-Dimensional ZnO Nanostructure: Realization of a Multifunctional Stable Superhydrophobic Surface
BACKGROUND: After comprehensive study of various superhydrophobic phenomena in nature, it is no longer a puzzle for researchers to realize such fetching surfaces. However, the different types of artificial surfaces may get wetted and lose its water repellence if there exist defects or the liquid is under pressure. With respect to the industry applications, in which the resistance of wetting transition is critical important, new nanostructure satisfied a certain geometric criterion should be designed to hold a stable gas film at the base area to avoid the wet transition. METHODOLOGY: A thermal deposition method was utilized to produce a thin ZnO seeds membrane on the aluminum foil. And then a chemical self-assemble technology was developed in present work to fabricate three-dimensional (3D) hierarchical dune-like ZnO architecture based on the prepared seeds membrane. RESULTS: Hierarchical ZnO with micro scale dune-like structure and core-sharing nanosheets was generated. The characterization results showed that there exist plenty of gaps and interfaces among the micro-dune and nanosheets, and thus the surface area was enlarged by such a unique morphology. Benefited from this unique 3D ZnO hierarchical nanostructure, the obtained surface exhibited stable water repellency after modification with Teflon, and furthermore, based on solid theory analysis, such 3D ZnO nanostructure would exhibit excellent sensing performance
Novel Molecular Targets of Azadirachta indica Associated with Inhibition of Tumor Growth in Prostate Cancer
Advanced prostate cancer has significant long-term morbidity, and there is a growing interest in alternative and complimentary forms of therapy that will improve the outcomes of patients. Azadirachta indica (common name: neem) contains multiple active compounds that have potent anti-inflammatory and anticancer properties. The present study investigates the novel targets of the anticancer activity of ethanol extract of neem leaves (EENL) in vitro and evaluates the in vivo efficacy in the prostate cancer models. Analysis of the components in the EENL by mass spectrometry suggests the presence of 2′,3′-dehydrosalannol, 6-desacetyl nimbinene, and nimolinone. Treatment of C4-2B and PC-3M-luc2 prostate cancer cells with EENL inhibited the cell proliferation. Genome-wide expression profiling, using oligonucleotide microarrays, revealed genes differentially expressed with EENL treatment in prostate cancer cells. Functional analysis unveiled that most of the up-regulated genes were associated with cell death, and drug metabolism, and the down-regulated genes were associated with cell cycle, DNA replication, recombination, and repair functions. Quantitative PCR confirmed significant up-regulation of 40 genes and immunoblotting revealed increase in the protein expression levels of HMOX1, AKR1C2, AKR1C3, and AKR1B10. EENL treatment inhibited the growth of C4-2B and PC-3M-luc2 prostate cancer xenografts in nude mice. The suppression of tumor growth is associated with the formation of hyalinized fibrous tumor tissue and the induction of cell death by apoptosis. These results suggest that EENL-containing natural bioactive compounds could have potent anticancer property and the regulation of multiple cellular pathways could exert pleiotrophic effects in prevention and treatment of prostate cancer
Identidad étnica y redes personales entre jóvenes de Sarajevo
After fieldwork conducted among young people in Sarajevo, we found a relation between the discourses sustained by them and the ethnic categories they use to classify people and to identify themselves. Also we have found that people self-affiliated as "Bosnians" play an important role in the network of multiethnic relationships, in which strong ties, surprisingly, are still very important. Finally we found a relationship between the composition of personal networks and the ethnic discourses that are maintained.Después de un trabajo de campo realizado con un grupo de jóvenes en Sarajevo, hemos constatado la existencia de una relación entre los discursos que sostienen y las categorías étnicas que utilizan tanto para clasificar a los demás como para auto-identificarse. Asimismo hemos encontrado que los jóvenes que se autodenominan "Bosnios" juegan un rol importante en la red de relaciones multiétnicas, en la que los lazos fuertes, sorprendentemente, son muy importantes. Finalmente hemos hallado una relación entre la composición de las redes personales y los discursos étnicos que se sostienen. Vivimos, o creemos vivir, en múltiples "comunidades", imaginadas o no. Al mismo tiempo, el individuo y no el lugar, la familia o el grupo, se sitúa en el centro de la vida social y de las comunicaciones (Cf. Wellman, 2001). En este contexto, inducido por el avance del capitalismo flexible (Castells, 1996), pensamos que para entender adecuadamente la identidad o identidades postuladas por los individuos es necesario estudiar las redes personales y su dinámica. Desde esta perspectiva no podemos hablar de "etnias" o "multietnicidad" sin más precisiones, pues son conceptos basados en una concepción esencialista y estática de la identidad individual. El concepto de "sociedad multiétnica" es utilizado de una manera engañosamente progresista y objetiva, pues lo que en realidad legitima es la existencia de diferencias esenciales entre personas, alejando en lugar de acercar. Sin embargo, somos plenamente conscientes que los discursos esencialistas de la identidad étnica son omnipresentes, con enormes efectos políticos e individuales. Que planteemos que la concepción esencialista de la identidad sea inapropiada desde un punto de vista académico, no significa que ésta no se utilice políticamente y por lo tanto tenga consecuencias formidables en las relaciones sociales. Precisamente el estudio de las redes personales nos permite situarnos en una perspectiva que no utiliza con pretensiones analíticas conceptos "folk", como son los de "etnia", "pueblo" o "nación", sino que los sitúa en el terreno de los discursos sustentados por los actores (y los estados y medios de comunicación) y nos permite contextualizarlos mediante conceptos etic, es decir, impuestos por los investigadores. Sólo así podemos superar las tautologías que abundan en los discursos étnicos
A chemical survey of exoplanets with ARIEL
Thousands of exoplanets have now been discovered with a huge range of masses, sizes and orbits: from rocky Earth-like planets to large gas giants grazing the surface of their host star. However, the essential nature of these exoplanets remains largely mysterious: there is no known, discernible pattern linking the presence, size, or orbital parameters of a planet to the nature of its parent star. We have little idea whether the chemistry of a planet is linked to its formation environment, or whether the type of host star drives the physics and chemistry of the planet’s birth, and evolution. ARIEL was conceived to observe a large number (~1000) of transiting planets for statistical understanding, including gas giants, Neptunes, super-Earths and Earth-size planets around a range of host star types using transit spectroscopy in the 1.25–7.8 μm spectral range and multiple narrow-band photometry in the optical. ARIEL will focus on warm and hot planets to take advantage of their well-mixed atmospheres which should show minimal condensation and sequestration of high-Z materials compared to their colder Solar System siblings. Said warm and hot atmospheres are expected to be more representative of the planetary bulk composition. Observations of these warm/hot exoplanets, and in particular of their elemental composition (especially C, O, N, S, Si), will allow the understanding of the early stages of planetary and atmospheric formation during the nebular phase and the following few million years. ARIEL will thus provide a representative picture of the chemical nature of the exoplanets and relate this directly to the type and chemical environment of the host star. ARIEL is designed as a dedicated survey mission for combined-light spectroscopy, capable of observing a large and well-defined planet sample within its 4-year mission lifetime. Transit, eclipse and phase-curve spectroscopy methods, whereby the signal from the star and planet are differentiated using knowledge of the planetary ephemerides, allow us to measure atmospheric signals from the planet at levels of 10–100 part per million (ppm) relative to the star and, given the bright nature of targets, also allows more sophisticated techniques, such as eclipse mapping, to give a deeper insight into the nature of the atmosphere. These types of observations require a stable payload and satellite platform with broad, instantaneous wavelength coverage to detect many molecular species, probe the thermal structure, identify clouds and monitor the stellar activity. The wavelength range proposed covers all the expected major atmospheric gases from e.g. H2O, CO2, CH4 NH3, HCN, H2S through to the more exotic metallic compounds, such as TiO, VO, and condensed species. Simulations of ARIEL performance in conducting exoplanet surveys have been performed – using conservative estimates of mission performance and a full model of all significant noise sources in the measurement – using a list of potential ARIEL targets that incorporates the latest available exoplanet statistics. The conclusion at the end of the Phase A study, is that ARIEL – in line with the stated mission objectives – will be able to observe about 1000 exoplanets depending on the details of the adopted survey strategy, thus confirming the feasibility of the main science objectives.Peer reviewedFinal Published versio
NLRP3 Inflammasome: Key Mediator of Neuroinflammation in Murine Japanese Encephalitis
Background: Japanese Encephalitis virus (JEV) is a common cause of acute and epidemic viral encephalitis. JEV infection is associated with microglial activation resulting in the production of pro-inflammatory cytokines including Interleukin-1 b (IL-1b) and Interleukin-18 (IL-18). The Pattern Recognition Receptors (PRRs) and the underlying mechanism by which microglia identify the viral particle leading to the production of these cytokines is unknown. Methodology/Principal Findings: For our studies, we have used murine model of JEV infection as well as BV-2 mouse microglia cell line. In this study, we have identified a signalling pathway which leads to the activation of caspase-1 as the key enzyme responsible for the maturation of both IL-1b and IL-18 in NACHT, LRR and PYD domains-containing protein-3 (NLRP3) dependent manner. Depletion of NLRP3 results in the reduction of caspase-1 activity and subsequent production of these cytokines. Conclusion/Significance: Our results identify a mechanism mediated by Reactive Oxygen Species (ROS) production and potassium efflux as the two danger signals that link JEV infection to caspase-1 activation resulting in subsequent IL-1b an
Superhydrophobic Surface Based on a Coral-Like Hierarchical Structure of ZnO
Background: Fabrication of superhydrophobic surfaces has attracted much interest in the past decade. The fabrication methods that have been studied are chemical vapour deposition, the sol-gel method, etching technique, electrochemical deposition, the layer-by-layer deposition, and so on. Simple and inexpensive methods for manufacturing environmentally stable superhydrophobic surfaces have also been proposed lately. However, work referring to the influence of special structures on the wettability, such as hierarchical ZnO nanostructures, is rare. Methodology: This study presents a simple and reproducible method to fabricate a superhydrophobic surface with microscale roughness based on zinc oxide (ZnO) hierarchical structure, which is grown by the hydrothermal method with an alkaline aqueous solution. Coral-like structures of ZnO were fabricated on a glass substrate with a micro-scale roughness, while the antennas of the coral formed the nano-scale roughness. The fresh ZnO films exhibited excellent superhydrophilicity (the apparent contact angle for water droplet was about 0u), while the ability to be wet could be changed to superhydrophobicity after spin-coating Teflon (the apparent contact angle greater than 168u). The procedure reported here can be applied to substrates consisting of other materials and having various shapes. Results: The new process is convenient and environmentally friendly compared to conventional methods. Furthermore, the hierarchical structure generates the extraordinary solid/gas/liquid three-phase contact interface, which is the essentia
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