2,472 research outputs found
Detection of transgenic and endogenous plant DNA in blood and organs of Nile tilapia, Oreochromis niloticus fed a diet formulated with genetically modified soybean meal
Anxiety regarding the fate of ingested transgenic DNA in farmed fish fed genetically modified (GM) soybean meal (SBM) has been raised with regard to human consumption. The objective of this study was to detect possibility of gene transfer of transgenic and endogenous DNA fragments in Nile tilapia (Oreochromis niloticus) blood and organs after consumption of a GM SBM diet. Nile tilapias with an average weight of 75.0 g were fed diets containing 48% GM or non-GM SBM for 21 days. During this period, a GM SBM diet was fed to fish for 12 days, and then switched to feed with non-GM SBM for 9 days for determining the residual span of the transferred cauliflower mosaic virus (CaMV) 35S promoter fragment. Blood, spleen, liver, intestine, kidney, and muscle tissues were taken (n = 10) every three days during the feeding period. Total DNA was extracted from the samples and analyzed by polymerase chain reaction (PCR) for determining the presence of a 108-bp fragment of the CaMV 35S promoter and a 144-bp fragment of the soybean chloroplast-specific DNA. Low-copy chloroplast-specific DNA fragment was detected in all organ and tissue samples and the majority of intestinal samples of fish fed GM SBM diet. Similarly, a low number and faint signals of the CaMV 35S promoter fragments were detected in all organ samples except muscle of fish fed the GM SBM diet, while none were detected 3 days after changing to a non-GM SBM diet. A very low frequency of transmittance to muscle and organs of fish was confirmed. It is recognized that the low copy number of transgenic DNA in the GM SBM diet is a challenge to their detection in tissues. These results suggested that transgenic DNA would be processed in the gastrointestinal tract in a similar manner with conventional plant DNA
Recommended from our members
Measuring Online Students\u27 Ability To Apply Programming Theory: Are Web Courses Really Working?
As a response to troubling doubts about the success of Web-delivered courses that include problem solving and critical thinking skills, the authors gathered data from two online sections of the CIS Application Programming with Visual Basic course at Metropolitan State College of Denver over two semesters and compared it with the data from classroom sections. T-tests showed a significant difference in the means of student projects and tests that required application of theory learned. All sections of the course used, the same syllabus and assignments and were taught by the same instructor. Internet students scored signifcantly lower in theory portions of exams and in projects. The authors conclude that more study is needed, but design and delivery of problem solving courses via the Web needs careful attention
Is The Computer The Medium And The Message? A Comparison Of Student VB Programming Performance In Three Delivery Modes
As a third stage of research on delivery of a popular programming course at Metropolitan State College of Denver, the authors gathered data from an online section of CIS Application Programming with Visual Basic, two interactive classroom deliveries in campus smart classrooms, and in two traditional lecture-based sections of the course. The authors had previously completed research which showed significant differences in student ability to apply concepts learned in online sections and classroom sections of the Visual Basic programming class. The addition of interactive classrooms on campus allowed them to reexamine the relationship between performance and style of delivery. The three modes of delivery--1) Web 2) Interactive Classroom and 3) Traditional Classroom--provided a rich source of data on student ability to apply theory. Data was gathered on a lab exam, a three phase semester-long programming project, and essay/coding problems on three in-class exams. Data from the five sections of the Visual Basic course were analyzed. Although the results were not as conclusive as the authors had hoped, an analysis of variance showed significant differences in one of the three measurements of students ability to apply theory— the programming project. A Fisher's pairwise comparison indicated that the Internet students performed significantly lower than students receiving the traditional classroom or interactive instruction method. The attrition rate for the Internet section was more than twice that of the other modes of delivery. Although the Interactive Classroom mode of delivery was not found to be significantly different, students did score slightly higher. All sections of the course used the same syllabus and assignments; the instructors used common examinations and rubrics for grading student assignments. The authors conclude that an interactive environment, within an instructor-led "smart classroom ", is preferable to Web based delivery, and perhaps the traditional lecture-based method of delivering programming classes. This style of delivery is more apt to produce a student who can apply theory and produce working code. As evidenced by performance on projects and subjective tests, students who participated in the interactive classroom sections were better able to apply programming theory to new situations. The authors caution that while traditional classroom delivery methods are well-established, Web courses and the interactive classrooms are still in their infancy. Further research is needed to verify their conclusions
Management of Post-Operative Endophthalmitis with Intravitreal Vancomycin and Amikacin
Aims: To assess the outcome of management of post-operative endophthalmitis with intravitreal injections of Vancomycin and Amikacin; both by measuring the visual acuity and assessing the corneal transparency. The study also aimed at identifying the causative organism, by culture and sensitivity and Gimsa staining of the vitreal tap. Materials and methods: This study was conducted in Makkah eye complex, Khartoum – Sudan, over a period from April 2003 till December 2004. Patients reported at out patient department(OPD) with signs and symptoms of endophthalmitis within six weeks after cataract surgery, they were examined initially for the visual acuity; then diffuse illumination and bio-microscopy examination was performed for grading clarity of cornea, and for checking presence of hypopyon or sufficient clouding of the anterior chamber, also intraocular inflammation was measured by the assessment of flare, cells, and inflammation membrane. Indirect ophthalmoscopy was performed to examine the red fundal glow and the status of the vitreous and retina. Inside the operating room vitreous and aqueous tap were done for the culture and sensitivity. Then the patients were treated with intravitreal and subconjuctival injection of Amikacin and Vancomycin. Results: In a total of (25) patients, pain and blurring of vision were found to be the most common symptoms, Insufficient corneal clarity 23 (92%) of patients, hypopyon was found at different levels in all patients, Red reflex was absent in 21 (84%) of patients. All the patients were found to have either vitritis, choroiditis or both in A and B scan. Post treatment findings of the 19 (76%) patients who attended the final six-month follow-up were as follow: The pain was relieved in all patients. The visual acuity had improved to a maximum of 6/18 one (5%) patient, 2 (10.5%) patients went into phthisis bulbi. The clarity of cornea was observed in 17 (89.5%) patients. Hypopyon disappeared from 17 (89.5%) of patients after injection. Fundal glow reappeared in 12 (63%) of patients. The results of remaining 6 (24%) patients who attended less than three-month follow-up period were as follow: Pain was relieved in (5) 83% of patients. The visual acuity reached a maximum of 3/60 in (1) 16.7% of patients, (1) 16.7% of the patients went into phthisis bulbi. The clarity of cornea was observed in (5) 83% of patients. (3)50% of patients were having no hypopyon after injection, fundal glow remains absent. Cultures were negative in (15) 60% of cases. (10) 40% showed confirmed growth of different organisms. Staphylococcus aureus (1) 4%, S. viridance (1) 4%, S. epidermidis (2) 8%, S. pyogenes (3) 12% and S. albus (3) 12%
Searching for zeroes: unconventional superconductors in a magnetic field
We review the results of the microscopic approach to the calculation of the
anisotropy in the specific heat in unconventional superconductors under rotated
field. Treating vortex scattering on equal footing with the energy shift we
find that the electronic specific heat may have minima or maxima when the field
is aligned with the nodes, depending on the temperature and field range. We
discuss the influence of the paramagnetic limiting and Fermi surface shape on
the location of the inversion line.Comment: Proceedings of SCES-0
Avalanche analysis from multi-electrode ensemble recordings in cat, monkey and human cerebral cortex during wakefulness and sleep
Self-organized critical states are found in many natural systems, from
earthquakes to forest fires, they have also been observed in neural systems,
particularly, in neuronal cultures. However, the presence of critical states in
the awake brain remains controversial. Here, we compared avalanche analyses
performed on different in vivo preparations during wakefulness, slow-wave sleep
and REM sleep, using high-density electrode arrays in cat motor cortex (96
electrodes), monkey motor cortex and premotor cortex and human temporal cortex
(96 electrodes) in epileptic patients. In neuronal avalanches defined from
units (up to 160 single units), the size of avalanches never clearly scaled as
power-law, but rather scaled exponentially or displayed intermediate scaling.
We also analyzed the dynamics of local field potentials (LFPs) and in
particular LFP negative peaks (nLFPs) among the different electrodes (up to 96
sites in temporal cortex or up to 128 sites in adjacent motor and pre-motor
cortices). In this case, the avalanches defined from nLFPs displayed power-law
scaling in double log representations, as reported previously in monkey.
However, avalanche defined as positive LFP (pLFP) peaks, which are less
directly related to neuronal firing, also displayed apparent power-law scaling.
Closer examination of this scaling using more reliable cumulative distribution
functions (CDF) and other rigorous statistical measures, did not confirm
power-law scaling. The same pattern was seen for cats, monkey and human, as
well as for different brain states of wakefulness and sleep. We also tested
other alternative distributions. Multiple exponential fitting yielded optimal
fits of the avalanche dynamics with bi-exponential distributions. Collectively,
these results show no clear evidence for power-law scaling or self-organized
critical states in the awake and sleeping brain of mammals, from cat to man.Comment: In press in: Frontiers in Physiology, 2012, special issue "Critical
Brain Dynamics" (Edited by He BY, Daffertshofer A, Boonstra TW); 33 pages, 13
figures. 3 table
- …