3,798 research outputs found
Ferrate(VI) oxidation of endocrine disruptors and antimicrobials in water
Author name used in this publication: X. Z. LiAccepted ManuscriptPublishe
Ferrate(VI) enhanced photocatalytic oxidation of pollutants in aqueous TiO?suspensions
Author name used in this publication: Nigel J. D. Graham2009-2010 > Academic research: refereed > Publication in refereed journalAccepted ManuscriptPublishe
An environmentally benign antimicrobial nanoparticle based on a silver-infused lignin core
Silver nanoparticles have antibacterial properties, but their use has been a cause for concern because they persist in the environment. Here, we show that lignin nanoparticles infused with silver ions and coated with a cationic polyelectrolyte layer form a biodegradable and green alternative to silver nanoparticles. The polyelectrolyte layer promotes the adhesion of the particles to bacterial cell membranes and, together with silver ions, can kill a broad spectrum of bacteria, including Escherichia coli, Pseudomonas aeruginosa and quaternary-amine-resistant Ralstonia sp. Ion depletion studies have shown that the bioactivity of these nanoparticles is time-limited because of the desorption of silver ions. High-throughput bioactivity screening did not reveal increased toxicity of the particles when compared to an equivalent mass of metallic silver nanoparticles or silver nitrate solution. Our results demonstrate that the application of green chemistry principles may allow the synthesis of nanoparticles with biodegradable cores that have higher antimicrobial activity and smaller environmental impact than metallic silver nanoparticles
SAAGs: Biased stochastic variance reduction methods for large-scale learning
Stochastic approximation is one of the effective approach to deal with the
large-scale machine learning problems and the recent research has focused on
reduction of variance, caused by the noisy approximations of the gradients. In
this paper, we have proposed novel variants of SAAG-I and II (Stochastic
Average Adjusted Gradient) (Chauhan et al. 2017), called SAAG-III and IV,
respectively. Unlike SAAG-I, starting point is set to average of previous epoch
in SAAG-III, and unlike SAAG-II, the snap point and starting point are set to
average and last iterate of previous epoch in SAAG-IV, respectively. To
determine the step size, we have used Stochastic Backtracking-Armijo line
Search (SBAS) which performs line search only on selected mini-batch of data
points. Since backtracking line search is not suitable for large-scale problems
and the constants used to find the step size, like Lipschitz constant, are not
always available so SBAS could be very effective in such cases. We have
extended SAAGs (I, II, III and IV) to solve non-smooth problems and designed
two update rules for smooth and non-smooth problems. Moreover, our theoretical
results have proved linear convergence of SAAG-IV for all the four combinations
of smoothness and strong-convexity, in expectation. Finally, our experimental
studies have proved the efficacy of proposed methods against the state-of-art
techniques
Faster learning by reduction of data access time
Nowadays, the major challenge in machine learning is the Big Data challenge.
The big data problems due to large number of data points or large number of
features in each data point, or both, the training of models have become very
slow. The training time has two major components: Time to access the data and
time to process (learn from) the data. So far, the research has focused only on
the second part, i.e., learning from the data. In this paper, we have proposed
one possible solution to handle the big data problems in machine learning. The
idea is to reduce the training time through reducing data access time by
proposing systematic sampling and cyclic/sequential sampling to select
mini-batches from the dataset. To prove the effectiveness of proposed sampling
techniques, we have used Empirical Risk Minimization, which is commonly used
machine learning problem, for strongly convex and smooth case. The problem has
been solved using SAG, SAGA, SVRG, SAAG-II and MBSGD (Mini-batched SGD), each
using two step determination techniques, namely, constant step size and
backtracking line search method. Theoretical results prove the same convergence
for systematic sampling, cyclic sampling and the widely used random sampling
technique, in expectation. Experimental results with bench marked datasets
prove the efficacy of the proposed sampling techniques and show up to six times
faster training
Pediatrics
OBJECTIVESTo describe the prevalence and secular trends of high weight-for-length among infants (ages, 3\u201323 months) in the biennial US Department of Agriculture Women, Infants, and Children Program and Participants Characteristic (WIC-PC) Survey from 2000 through 2014 (n = 16 927 120).METHODSWeight-for-length was considered to be \u201chigh\u201d if it was  652 SDs above the sex-and age-specific median in the World Health Organization growth standards. Poisson regression was used to calculate adjusted prevalence ratios.RESULTSThe overall prevalence of high weight-for-length increased from 13.4% in 2000 to 14.5% in 2004, remained constant until 2010, and then decreased by >2 percentage points (to 12.3%) through 2014. The prevalence of high weight-for-length was associated with sex (higher among boys), race-ethnicity (highest among American Indians/Alaskan Natives), and with both age (positive) and family income (inverse). The secular trends, however, were fairly similar within categories of these variables. From 2010 to 2014, the prevalence of high weight-for-length decreased in 40 states and 3 (of 5) US territories, with the largest decreases seen in Puerto Rico ( 129 percentage points) and Kentucky ( 127 percentage points), and the largest increase (+2 percentage points) seen in West Virginia.CONCLUSIONSAlthough the current results cannot be considered representative of infants in the populations, the prevalence of a high weight-for-length has decreased among infants in WIC-PC since 2010. These decreases were similar across categories of most characteristics, but there were substantial differences across jurisdictions, possibly reflecting differences in policy and local programs that target maternal and infant health.20162018-01-01T00:00:00ZCC999999/Intramural CDC HHS/United States27965380PMC5359001777
Clinicopathological Profile and Surgical Treatment of Abdominal Tuberculosis: A Single Centre Experience in Northwestern Tanzania.
Abdominal tuberculosis continues to be a major public health problem worldwide and poses diagnostic and therapeutic challenges to general surgeons practicing in resource-limited countries. This study was conducted to describe the clinicopathological profile and outcome of surgical treatment of abdominal tuberculosis in our setting and compare with what is described in literature. A prospective descriptive study of patients who presented with abdominal tuberculosis was conducted at Bugando Medical Centre (BMC) in northwestern Tanzania from January 2006 to February 2012. Ethical approval to conduct the study was obtained from relevant authorities. Statistical data analysis was performed using SPSS version 17.0. Out of 256 patients enrolled in the study, males outnumbered females. The median age was 28 years (range = 16-68 years). The majority of patients (77.3%) had primary abdominal tuberculosis. A total of 127 (49.6%) patients presented with intestinal obstruction, 106 (41.4%) with peritonitis, 17 (6.6%) with abdominal masses and 6 (2.3%) patients with multiple fistulae in ano. Forty-eight (18.8%) patients were HIV positive. A total of 212 (82.8%) patients underwent surgical treatment for abdominal tuberculosis. Bands /adhesions (58.5%) were the most common operative findings. Ileo-caecal region was the most common bowel involved in 122 (57.5%) patients. Release of adhesions and bands was the most frequent surgical procedure performed in 58.5% of cases. Complication and mortality rates were 29.7% and 18.8% respectively. The overall median length of hospital stay was 32 days and was significantly longer in patients with complications (p < 0.001). Advanced age (age ≥ 65 years), co-morbid illness, late presentation, HIV positivity and CD4+ count < 200 cells/μl were statistically significantly associated with mortality (p < 0.0001). The follow up of patients were generally poor as only 37.5% of patients were available for follow up at twelve months after discharge. Abdominal tuberculosis constitutes a major public health problem in our environment and presents a diagnostic challenge requiring a high index of clinical suspicion. Early diagnosis, early anti-tuberculous therapy and surgical treatment of the associated complications are essential for survival
RNA interference: A novel tool for plant disease management
Plant diseases pose a huge threat to crop production globally. Variations in their genomes cause selection to favor those who can survive pesticides and Bacillus thuringiensis (Bt) crops. Though plant breeding has been the classical means of manipulating the plant genome to develop resistant cultivar for controlling plant diseases, the advent of genetic engineering provides an entirely new approach being pursued to render plants resistant to fungi, bacteria, viruses and nematodes. RNA interference (RNAi) technology has emerged to be a promising therapeutic weapon to mitigate the inherent risks such as the use of a specific transgene, marker gene, or gene control sequences associated with development of traditional transgenics. Silencing specific genes by RNAi is a desirable natural solution to this problem as disease resistant transgenic plants can be produced within a regulatory framework. Recent studies have been successful in producing potent silencing effects by using target doublestranded RNAs through an effective vector system. Transgenic plants expressing RNAi vectors, as well as, dsRNA containing crop sprays have been successful for efficient control of plant pathogens affecting economically important crop species. The present paper discusses strategies and applications of this novel technology in plant disease management for sustainable agriculture production.Keywords: Plant disease, RNA interference, transgene, managementAfrican Journal of Biotechnology Vol. 12(18), pp. 2303-231
Wheat-barley hybridization – the last forty years
Abstract Several useful alien gene transfers have
been reported from related species into wheat (Triticum
aestivum), but very few publications have dealt
with the development of wheat/barley (Hordeum
vulgare) introgression lines. An overview is given
here of wheat 9 barley hybridization over the last
forty years, including the development of
wheat 9 barley hybrids, and of addition and translocation
lines with various barley cultivars. A short
summary is also given of the wheat 9 barley hybrids
produced with other Hordeum species. The meiotic
pairing behaviour of wheat 9 barley hybrids is presented,
with special regard to the detection of wheat–
barley homoeologous pairing using the molecular
cytogenetic technique GISH. The effect of in vitro
multiplication on the genome composition of intergeneric
hybrids is discussed, and the production and
characterization of the latest wheat/barley translocation
lines are presented. An overview of the agronomical
traits (b-glucan content, earliness, salt tolerance,
sprouting resistance, etc.) of the newly developed
introgression lines is given. The exploitation and
possible use of wheat/barley introgression lines for
the most up-to-date molecular genetic studies
(transcriptome analysis, sequencing of flow-sorted
chromosomes) are also discussed
- …
