Nitrogen Mineralization in Selected Solid Waste Dumpsites in Port Harcourt, Nigeria.

Organic wastes in selected waste dumpsites in Port Harcourt were successively incubated with sandy-loam soils for days at 27ºC, under aerobic conditions. The results showed marked decrease in total nitrogen in the organic wastes which was observed as loss of nitrogen. The process of nitrification and incorporation of (NH4)2SO4 affected the pH which ranged from 5.9 to 7.9. The cumulative mineral nitrogen released increased with incubation periods and the rate of organic application up to 28th day, with a maximum release of 456.40ppm at a rate of 61MT/ha organic application. The release of mineral N decreased on the 56th day with a minimum of 177.80ppm ata rate of 60MT/ha of organic fertilizer only. An enriched organic. Waste soil and organic waste treated soil had a boosting effect on the release of mineral nitrogen. The amount of mineral nitrogen released was higher for (NH4)2SO4 fertilizer treated soil than for organic waste treated soil. The mineralization rate was found to decrease with increasing age of the waste dumps. It was therefore recommended that organic wastes should be sorted and composted for use as organic fertilizers to augment inorganic fertilizer

PC-CUBE: A Personal Computer Based Hypercube

PC-CUBE is an ensemble of IBM PCs or close compatibles connected in the hypercube topology with ordinary computer cables. Communication occurs at the rate of 115.2 K-band via the RS-232 serial links. Available for PC-CUBE is the Crystalline Operating System III (CrOS III), Mercury Operating System, CUBIX and PLOTIX which are parallel I/O and graphics libraries. A CrOS performance monitor was developed to facilitate the measurement of communication and computation time of a program and their effects on performance. Also available are CXLISP, a parallel version of the XLISP interpreter; GRAFIX, some graphics routines for the EGA and CGA; and a general execution profiler for determining execution time spent by program subroutines. PC-CUBE provides a programming environment similar to all hypercube systems running CrOS III, Mercury and CUBIX. In addition, every node (personal computer) has its own graphics display monitor and storage devices. These allow data to be displayed or stored at every processor, which has much instructional value and enables easier debugging of applications. Some application programs which are taken from the book Solving Problems on Concurrent Processors (Fox 88) were implemented with graphics enhancement on PC-CUBE. The applications range from solving the Mandelbrot set, Laplace equation, wave equation, long range force interaction, to WaTor, an ecological simulation

Assessment of Air Quality and Noise around Okrika Communities, Rivers State, Nigeria

The quality of air and noise levels around Okirika communities in River State were determined using portable hand held air monitors for air pollutants and anemometer for meteorological parameters. The parameters measured were suspended particulate matter, nitrogen dioxide, sulphur dioxide, hydrogen sulphide, ammonia, carbon monoxide, methane and volatile organic carbon, temperature, wind speed, wind direction and relative humidity. The results showed the highest concentrations of 0.007mg/m3 (PM1, dry), 0.036mg/m3 (PM2.5, dry), 0.286mg/m3 (PM7, dry), 0.378mg/m3 (PM10, dry), 0.503mg/m3 (TSP, dry), 1.7ppm (NO2, dry), 3.0ppm (CH4, dry), 0.2ppm (H2S, dry), 12.7ppm (CO, dry), 2.7ppm (NH3, dry), and 7.0ppm (VOC, rainy). The dry season concentrations of air pollutants were higher than the rainy season concentrations. The observed differences in mean concentrations of the air pollutants between the two seasons were not significant in case of TSP (P<0.05) but were significant (P<0.05) in other pollutants. The highest mean concentrations of the gaseous pollutants exceeded permissible limits and therefore pose environmental and health concern for the inhabitants of the area. The quality of air in the area is poor and need to be regularly monitored. @JASEMKeywords: Air quality, Okrika, Digital monitors, meteorology, Nois

Does Chatting Really Help? Tweet Analytics and Analyst Forecast Dispersion

Financial analysts use tweet analytics to prepare their forecasts, yet little information that describes how they do so exists. To address this gap, we scrutinize the associative relationships between tweets about a company’s service and the dispersion of analyst forecasts about the same company’s financial performance. We developed three sets of hypotheses. We extracted tweets related to airlines from the Twitter data from Archive Team and analyst forecast data from Institutional Brokers’ Estimate System Academic. We obtained airline-related tweets from nearly 200,000 individual Twitter users about 10 airlines during a 55-month study period and ran multiple regressions to test the associations between tweet characteristics and forecast dispersion. Our results suggest that, when more posters generate more tweets about a company’s service, analysts make less dispersed forecasts. In addition, negative (or non-verified) tweets reduce forecast dispersion to a greater extent than positive (or verified) tweets do. Theoretically, this paper confirms that Twitter can be a useful data source to provide analysts with additional information to prepare their forecasts. Practically, our findings provide empirical evidence about how Twitter data is associated with analyst forecast dispersion. We encourage stakeholders (such as analysts from small firms and individual investors) to extract data from Twitter as a supplement to market information when analyzing data

Selective remodeling of cardiolipin fatty acids in the aged rat heart

BACKGROUND: The heart is rich in cardiolipin, a phospholipid acylated in four sites, predominately with linoleic acid. Whether or not aging alters the composition of cardiolipin acyl chains is controversial. We therefore measured the fatty acid concentration of cardiolipin in hearts of 4, 12 and 24 month old rats that consumed one diet, adequate in fatty acids for the duration of their life. RESULTS: The concentration (nmol/g) of linoleic acid was decreased in 24 month old rats (3965 ± 617, mean ± SD) vs 4 month old rats (5525 ± 656), while the concentrations of arachidonic and docosahexaenoic acid were increased in 24 month old rats (79 ± 9 vs 178 ± 27 and 104 ± 16 vs 307 ± 68 for arachidonic and docosahexaenoic acids, 4 months vs 24 months, respectively). Similar changes were not observed in ethanolamine glycerophospholipids or plasma unesterified fatty acids, suggesting specificity of these effects to cardiolipin. CONCLUSION: These results demonstrate that cardiolipin remodeling occurs with aging, specifically an increase in highly unsaturated fatty acids

Improving Generative Flow Networks with Path Regularization

Generative Flow Networks (GFlowNets) are recently proposed models for learning stochastic policies that generate compositional objects by sequences of actions with the probability proportional to a given reward function. The central problem of GFlowNets is to improve their exploration and generalization. In this work, we propose a novel path regularization method based on optimal transport theory that places prior constraints on the underlying structure of the GFlowNets. The prior is designed to help the GFlowNets better discover the latent structure of the target distribution or enhance its ability to explore the environment in the context of active learning. The path regularization controls the flow in GFlowNets to generate more diverse and novel candidates via maximizing the optimal transport distances between two forward policies or to improve the generalization via minimizing the optimal transport distances. In addition, we derive an efficient implementation of the regularization by finding its closed form solutions in specific cases and a meaningful upper bound that can be used as an approximation to minimize the regularization term. We empirically demonstrate the advantage of our path regularization on a wide range of tasks, including synthetic hypergrid environment modeling, discrete probabilistic modeling, and biological sequence design.Comment: 28 pages, 2 figures, 5 tables. Anh Do, Duy Dinh, and Tan Nguyen contributed equally to this wor

Strongly enhanced photon collection from diamond defect centres under micro-fabricated integrated solid immersion lenses

The efficiency of collecting photons from optically active defect centres in bulk diamond is greatly reduced by refraction and reflection at the diamond-air interface. We report on the fabrication and measurement of a geometrical solution to the problem; integrated solid immersion lenses (SILs) etched directly into the surface of diamond. An increase of a factor of 10 was observed in the saturated count-rate from a single negatively charged nitrogen-vacancy (NV-) within a 5um diameter SIL compared with NV-s under a planar surface in the same crystal. A factor of 3 reduction in background emission was also observed due to the reduced excitation volume with a SIL present. Such a system is potentially scalable and easily adaptable to other defect centres in bulk diamond.Comment: 5 Pages, 5 figures (4 subfigures) - corrected typ