3,519 research outputs found
Adsorptive removal of various phenols from water by South African coal fly ash
South African coal fly ash (SACFA) was used to effectively remove phenol, 2-nitrophenol and 4-nitrophenol from wastewater. The rate of adsorption follows first-order kinetics before attaining equilibrium with the sorption rate (Kad) obtained being the  highest for 4-nitrophenol (p-nitrophenol) (7.0 x 10.3/h), followed by phenol (1.2 x 10.3/h) and 2-nitrophenol (o-nitrophenol) (1.0 x 10.3/h). Batch studies were performed to evaluate the adsorption process, and it was found that the Freundlich isothermeffectively fits the experimental data for the adsorbates better than the Langmuir model, with the fly ash having the highest adsorption capacity of 6.51 X 10-2 mg/g for 4-nitrophenol, 6.00 x 10-2 mg/g for 2-nitrophenol and 6.31 x10-2 mg/g for phenol. The fly ash was found to adsorb 90.2% of phenol, 88.9% of 2-nitrophenol and 92.6% of 4-nitrophenol at an initialconcentration of 20 mg/.. The desorption studies suggested that the desorption of 4-nitrophenol was the most difficult of the three adsorbates to be desorbed. The desorption efficiency was 17.9% for phenol, 18.8% for 2-nitrophenol and 10.2% for 4-nitrophenol. This work proved that SACFA can be used as an efficient adsorbent material for removal of phenol from water and wastewater
Cug2 is essential for normal mitotic control and CNS development in zebrafish.
Background:
We recently identified a novel oncogene, Cancer-upregulated gene 2 (CUG2), which is essential for kinetochore formation and promotes tumorigenesis in mammalian cells. However, the in vivo function of CUG2 has not been studied in animal models.
Results:
To study the function of CUG2 in vivo, we isolated a zebrafish homologue that is expressed specifically in the proliferating cells of the central nervous system (CNS). Morpholino-mediated knockdown of cug2 resulted in apoptosis throughout the CNS and the development of neurodegenerative phenotypes. In addition, cug2-deficient embryos contained mitotically arrested cells displaying abnormal spindle formation and chromosome misalignment in the neural plate.
Conclusions:
Therefore, our findings suggest that Cug2 is required for normal mitosis during early neurogenesis and has functions in neuronal cell maintenance, thus demonstrating that the cug2 deficient embryos may provide a model system for human neurodegenerative disorders
The clinical usefulness of initial serum procalcitonin as an aggravation predictor in a hepatobiliary tract infection at emergency department
Background and Objectives: The ability to predict future clinical deterioration early in patients who present to an emergency care center with a hepatobiliary tract infection is difficult. We studied the clinical usefulness of the initial serum levels of procalcitonin in a hepatobiliary tract infection as an indicator for predicting aggravation in the early stages.Methods: Of the patients who presented with the clinical symptoms of a hepatobiliary tract infection, 99 were diagnosed with a hepatobiliary tract infection by imaging studies and subsequently enrolled in the study. Laboratory tests were obtained in the early stage of disease after presentation to an emergency care center. We assessed and compared the serum levels of many early inflammatory markers (white blood cell [WBC] counts, C‑reactive protein and procalcitonin) between patients whose symptoms were initially stable upon arrival to an emergency care center but then deteriorated to, those whose symptoms remained consistently stable. Thus, we examined if the above serum markers are useful in predicting the possibility of future symptom aggravation.Results: Of a total of 99 patients, 27 were assigned to the symptom aggravation group. The serum levels of WBC counts and C‑reactive protein in the aggravation group were elevated. However, the median value (interquartile range) of procalcitonin was relatively increased at 2.28 (0.41–7.84 ng/ml), demonstrating a significant difference.Conclusions: In conclusion, initial serum levels of procalcitonin might be used as an indicator for aggravation in patients with hepatobiliary tract infection at the emergency department, even though there is hemodynamic stability.Key words: Hepatobiliary tract, infection, procalcitoni
FIH-1, a novel interactor of mindbomb, functions as an essential anti-angiogenic factor during zebrafish vascular development
Objective: It has been shown that Mindbomb (Mib), an E3 Ubiquitin ligase, is an essential modulator of Notch signaling during development. However, its effects on vascular development remain largely unknown
Comparison of Stemness and Gene Expression between Gingiva and Dental Follicles in Children
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Effects of Explicit Convection on Future Projections of Mesoscale Circulations, Rainfall, and Rainfall Extremes over Eastern Africa
Eastern Africa’s fast-growing population is vulnerable to changing rainfall and extremes. Using the first pan-African climate change simulations that explicitly model the rainfall-generating convection, we investigate both the climate change response of key mesoscale drivers of eastern African rainfall, such as sea and lake breezes, and the spatial heterogeneity of rainfall responses. The explicit model shows widespread increases at the end of the century in mean (~40%) and extreme (~50%) rain rates, whereas the sign of changes in rainfall frequency has large spatial heterogeneity (from −50% to over +90%). In comparison, an equivalent parameterized simulation has greater moisture convergence and total rainfall increase over the eastern Congo and less over eastern Africa. The parameterized model also does not capture 1) the large heterogeneity of changes in rain frequency; 2) the widespread and large increases in extreme rainfall, which result from increased rainfall per humidity change; and 3) the response of rainfall to the changing sea breeze, even though the sea-breeze change is captured. Consequently, previous rainfall projections are likely inadequate for informing many climate-sensitive decisions—for example, for infrastructure in coastal cities. We consider the physics revealed here and its implications to be relevant for many other vulnerable tropical regions, especially those with coastal convection
Timing by Stellar Pulsations as an Exoplanet Discovery Method
The stable oscillations of pulsating stars can serve as accurate timepieces,
which may be monitored for the influence of exoplanets. An external companion
gravitationally tugs the host star, causing periodic changes in pulsation
arrival times. This method is most sensitive to detecting substellar companions
around the hottest pulsating stars, especially compact remnants like white
dwarfs and hot subdwarfs, as well as delta Scuti variables (A stars). However,
it is applicable to any pulsating star with sufficiently stable oscillations.
Care must be taken to ensure that the changes in pulsation arrival times are
not caused by intrinsic stellar variability; an external, light-travel-time
effect from an exoplanet identically affects all pulsation modes. With more
long-baseline photometric campaigns coming online, this method is yielding new
detections of substellar companions.Comment: 9 pages, 2 figures: Invited review to appear in 'Handbook of
Exoplanets,' Springer Reference Works, edited by Hans J. Deeg and Juan
Antonio Belmont
RepAtt: Achieving Swarm Coordination through Chemotaxis
Swarm foraging is a common test case application for multi-robot systems. In this paper we present a novel algorithm for improving coordination of a robot swarm by selectively broadcasting repulsion and attraction signals. Robots use a chemotaxis-inspired search behaviour based on the temporal gradients of these signals in order to navigate towards more advantageous areas. Hardware experiments were used to model and validate realistic, noisy sound communication. We then show through extensive simulation studies that our chemotaxis-based coordination algorithm significantly improves swarm foraging time and robot efficiency
Solving the subset-sum problem with a light-based device
We propose a special computational device which uses light rays for solving
the subset-sum problem. The device has a graph-like representation and the
light is traversing it by following the routes given by the connections between
nodes. The nodes are connected by arcs in a special way which lets us to
generate all possible subsets of the given set. To each arc we assign either a
number from the given set or a predefined constant. When the light is passing
through an arc it is delayed by the amount of time indicated by the number
placed in that arc. At the destination node we will check if there is a ray
whose total delay is equal to the target value of the subset sum problem (plus
some constants).Comment: 14 pages, 6 figures, Natural Computing, 200
Discrete Particle Swarm Optimization for the minimum labelling Steiner tree problem
Particle Swarm Optimization is an evolutionary method inspired by the
social behaviour of individuals inside swarms in nature. Solutions of the problem are
modelled as members of the swarm which fly in the solution space. The evolution is
obtained from the continuous movement of the particles that constitute the swarm
submitted to the effect of the inertia and the attraction of the members who lead the
swarm. This work focuses on a recent Discrete Particle Swarm Optimization for combinatorial optimization, called Jumping Particle Swarm Optimization. Its effectiveness is
illustrated on the minimum labelling Steiner tree problem: given an undirected labelled
connected graph, the aim is to find a spanning tree covering a given subset of nodes,
whose edges have the smallest number of distinct labels
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