165 research outputs found
Effect of salinity on gestation period, fry production, and growth performance of the sailfin molly (Poecilia latipinna lesueur) in captivity
Breeding and growth trials were carried out with Poecilia latipinna in different salinities (0.5, 10, 15, 25, and 35‰) and effects on gestation period, fry production, and fry growth (75 days) were examined. Results showed that while P. latipinna successfully spawned in all salinities, there was a significant difference in fry production among treatments. The minimum gestation period was 28 days in all salinities except fresh water (0.5‰); the maximum fry production was obtained in 25‰. Fry growth was highest in 10‰ and significantly differed (p<0.05) from the rest of treat- ments in terms of weight gain, specific growth rate (SGR), and feed conversion ratio (FCR). Maximum SGR was 3.35% per day in 10‰ salinity. FCR ranged 4.28-5.67. The results suggest that the optimum salinities for breeding and rearing P. latipinna are around 25‰ and 10‰, respectively
ANTI-TUMOUR ACTIVITY OF BROMOPYRROLE ALKALOIDS AGAINST HUMAN BREAST TUMOUR (MCF-7) THROUGH APOPTOSIS INDUCTION
Objective: The present study was conducted to screen the cytotoxicity and initiation of apoptosis in MCF-7 human breast tumour cells using the Indian sponge Acanthostylotela cornuta of the Gulf of Mannar.
Methods: The crude methanol extract of A. cornuta was fractionated using a reversed phase silica gel column chromatography. The purity of the active fraction of bromopyrrole alkaloids was confirmed with Gas Chromatography-Mass Spectrometry (GCMS). The bromopyrrole alkaloids induce apoptotic changes in MCF-7 cells were studied with electrophoresis, caspase assay, and different staining analysis. The MCF-7 cells were analyzed by Flow cytometry to determine their DNA content.
Results: Bromopyrrole alkaloids of A. cornuta showed cytotoxicity against MCF-7 human breast tumour cells with the IC50 value of 8.0μg/ml. The bromopyrrole compounds induced cells exhibited scatted red fluorescence, showing the presence of several residual bodies and condensation of chromatin. Caspase-3, pro-caspase-9, caspase-9 and Poly-ADP-Ribose-Polymerase (PARP) activity were occurred in bromopyrrole alkaloids treated tumour cell. The cell cycle arrest is conceivable that the compound prevented the progression of cell cycle through the G phase resulting from inhibition of survival, leading them to undergo apoptosis.
Conclusion: Bromopyrrole alkaloids of A. cornuta possess antitumor activity which was arrested the G phase in cell cycle that clearly indicated its nature as that of antitumour drugs
Studies on Cobalt(III) Metallosurfactants. Kinetics and Mechanism of Reduction of Cobalt(III) by Iron(II) in Aqueous Acid Medium
The kinetics and mechanism of reduction of the surfactant complex ions, cis-chloro/bromo(dodecylamine)(triethylenetetramine)cobalt(III) by iron(II) in aqueous solution were studied at 303, 308 and 313 K by spectrophotometry under pseudo-first-order conditions using an excess of the reductant. The second-order rate constant increases with cobalt(III) concentration and the presence of aggregation of the complex itself alters the reaction rate. The reductions are acid-independent in the range [H+] = 0.05-0.25mol dm−3. Variation of ionic strength (μ) influences the reaction rate. Activation and thermodynamic parameters have been computed. It is suggested that the reaction of Fe2+(aq) with the cobalt(III) complex proceeds by an inner-sphere mechanism. The critical micelle concentration (CMC) values of these surfactant metal complexes in aqueous solution were obtained from conductance measurements. Specific conductivity data (at 303, 308 and 313 K) served for the evaluation of the temperature-dependent CMC and the standard Gibbs energy of micellization (ΔGm0
RanDumb: a simple approach that questions the efficacy of continual representation learning
We propose RanDumb to examine the efficacy of continual representation learning. RanDumb embeds raw pixels using a fixed random transform which approximates an RBF-Kernel, initialized before seeing any data, and learns a simple linear classifier on top. We present a surprising and consistent finding: RanDumb significantly outperforms the continually learned representations using deep networks across numerous continual learning benchmarks, demonstrating the poor performance of representation learning in these scenarios. RanDumb stores no exemplars and performs a single pass over the data, processing one sample at a time. It complements GDumb [39], operating in a lowexemplar regime where GDumb has especially poor performance. We reach the same consistent conclusions when RanDumb is extended to scenarios with pretrained models replacing the random transform with pretrained feature extractor. Our investigation is both surprising and alarming as it questions our understanding of how to effectively design and train models that require efficient continual representation learning, and necessitates a principled reinvestigation of the widely explored problem formulation itself. Our code is available here
Developing and evaluating a five minute phishing awareness video
Confidence tricksters have always defrauded the unwary. The computer era has merely extended their range and made it possible for them to target anyone in the world who has an email address. Nowadays, they send phishing messages that are specially crafted to deceive. Improving user awareness has the potential to reduce their effectiveness. We have previously developed and empirically-validated phishing awareness programmes. Our programmes are specifically designed to neutralize common phish-related misconceptions and teach people how to detect phishes. Many companies and individuals are already using our programmes, but a persistent niggle has been the amount of time required to complete the awareness programme. This paper reports on how we responded by developing and evaluating a condensed phishing awareness video that delivered phishing awareness more efficiently. Having watched our video, participants in our evaluation were able to detect phishing messages significantly more reliably right after watching the video (compared to before watching the video). This ability was also demonstrated after a retention period of eight weeks after first watching the video
The effects of the 2004 Tsunami on mainland India and the Andaman and Nicobar Islands
Mortality from the tsunamis was high, with more than 7,000 deaths in the Nicobar
group alone (the final number may never be known as many indigenous people on
remote islands may have perished). On the mainland, there were a similar number
of fatalities ;
The greatest losses were in fishing communities although the waves destroyed roads,
jetties, other basic infrastructure and entire villages;
There was major damage to the coastal resources of southeast India, particularly
to mangrove and coastal forests. On the Andaman and Nicobar Islands there was
considerable damage to the coral reefs and beaches, as well as the forests;
The earthquakes changed the bathymetry of the coral reefs and coasts of the Andaman
and Nicobars: reefs in the South Andamans to the Nicobars subsided by 1 - 3 metres;
many reefs in the northern Andamans were uplifted out of the water and died; and
some beaches have almost disappeared, while new beaches have formed;
There was major damage to large areas of coral reefs of the Andamans and Nicobars,
particularly due to debris being washed off the land and smothering by sediments;
Mainland coral reefs in the Gulf of Mannar and elsewhere suffered very minor,
localised damage. Many mainland beaches were seriously eroded; and
The affected reefs are expected to recover within 5-10 years, if there is effective
resource management and enforcement of legislation controlling destructive fishing,
coral mining, over-harvesting of reef resources, coastal development, sedimentation
and pollution
Tooth Discoloration in Patients With Neonatal Diabetes After Transfer Onto Glibenclamide: A previously unreported side effect
PublishedJournal ArticleMulticenter StudyResearch Support, N.I.H., ExtramuralResearch Support, Non-U.S. Gov'tOBJECTIVE To assess if tooth discoloration is a novel side effect of sulfonylurea therapy in patients with permanent neonatal diabetes due to mutations in KCNJ11. RESEARCH DESIGN AND METHODS A total of 67 patients with a known KCNJ11 mutation who had been successfully transferred from insulin injections onto oral sulfonylureas were contacted and asked about the development of tooth discoloration after transfer. RESULTS Altered tooth appearance was identified in 5 of the 67 patients. This was variable in severity, ranging from mild discoloration/staining (n = 4) to loss of enamel (n = 1) and was only seen in patients taking glibenclamide (glyburide). CONCLUSIONS These previously unreported side effects may relate to the developing tooth and/or to the high local concentrations in the children who frequently chewed glibenclamide tablets or took it as a concentrated solution. Given the multiple benefits of sulfonylurea treatment for patients with activating KCNJ11 mutations, this association warrants further investigation but should not preclude such treatment.This work was funded by the Welcome Trust (grant 067463/Z/2/Z), National Institutes of Health Grants DK-44752 and DK-20595, and a gift from the Kovler Family Foundation. S.E.F. is the Sir
Graham Wilkins, Peninsula Medical School Research Fellow. A.T.H. is a Welcome Trust
Research Leave Fellow. O.R.-C. was supported by an “Ayuda para contratos post-Formacio´n
Sanitaria Especializada” from the “Instituto de Salud Carlos III” (FIS CM06/00013
A Usability Evaluation of Privacy Add-ons for Web Browsers
The web has improved our life and has provided us with more opportunities to access information and do business. Nonetheless, due to the prevalence of trackers on websites, web users might be subject to profiling while accessing the web, which impairs their online privacy. Privacy browser add-ons, such as DuckDuckGo Privacy Essentials, Ghostery and Privacy Badger, extend the privacy protection that the browsers offer by default, by identifying and blocking trackers. However, the work that focuses on the usability of the privacy add-ons, as well as the users’ awareness, feelings, and thoughts towards them, is rather limited. In this work, we conducted usability evaluations by utilising System Usability Scale and Think-Aloud Protocol on three popular privacy add-ons, i.e., DuckDuckGo Privacy Essentials, Ghostery and Privacy Badger. Our work also provides insights into the users’ awareness of online privacy and attitudes towards the abovementioned privacy add-ons; in particular trust, concern, and control. Our results suggest that the participants feel safer and trusting of their respective add-on. It also uncovers areas for add-on improvement, such as a more visible toolbar logo that offers visual feedback, easy access to thorough help resources, and detailed information on the trackers that have been found
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