1,870 research outputs found
Effects of co-treatment of Rauwolfia vomitoria and Gongronema latifolium on neurobehaviour and the neurohistology of the cerebral cortex in mice
Rauwolfia vomitoria and Gongronema latifolium are medicinal plants with antioxidant, antidiabetic and analgesic properties among others. R. vomitoria is reported to possess adverse neural effects, which G. latifolium has shown the potential to address. This study therefore investigated the effects of co-treatment of R. vomitoria and G. latifolium on the neurobehaviour and histology of the cerebral cortex of female mice. Twenty female Wistar mice were divided into 4 groups (A, B, C and D). Group A designated as the control received 0.4 mL of 20 % Tween, while groups B, C and D received oral doses of 150 mg/kg of R. vomitoria (RV), 200 mg/kg of G. latifolium (GL) and a combination of 150 mg/kg of R. vomitoria and 200 mg/kg of G. latifolium (RV+GL), respectively for seven days. Light and dark field behaviour test was carried out on day 8 and the animals were immediately sacrificed. Their brains were excised and routinely processed by haematoxylin and eosin method. There was no difference in body and brain weights, and the behavioural parameters. Cellular cyto-architecture showed higher glial population with no apparent histopathology. The cellular population was higher (p<0.0001) in the RV and RV+GL groups, while the GL group was less (p<0.0001) populated all compared to the control.In conclusion, the reported treatment regimes, RV administered singly and in combination with GL may not affect some neurobehavioural activities, but may result in cellular increase in the cerebral cortex.KEY WORDS: Rauwolfia vomitoria; Gongronema latifolium; Cerebral cortex; Mic
Electromagnetic Form Factors in the hypercentral CQM
We report on the recent results of the hypercentral Constituent Quark Model
(hCQM). The model contains a spin independent three-quark interaction which is
inspired by Lattice QCD calculations and reproduces the average energy values
of the SU(6) multiplets. The splittings are obtained with a SU(6)-breaking
interaction, which can include also an isospin dependent term. Concerning
Constituent Quark models, we have shown for the first time that the decreasing
of the ratio of the elastic form factors of the proton is due to relativistic
effects using relativistic corrections to the e.m. current and boosts. Now the
elastic nucleon form factors have been recalculated, using a relativistic
version of the hCQM and a relativistic quark current showing a very detailed
reproduction of all the four form factor existing data over the complete range
of 0-4 . Futhermore, the model has been used for predictions concerning
the electromagnetic transverse and longitudinal transition form factors giving
a good description of the medium behaviour. We show that the
discrepancies in the reproduction of the helicity amplitudes at low are
due to pion loops. We have calculated the helicity amplitudes for all the 3 and
4 star resonances opening the possibility of application to the evaluation of
cross sections.Comment: 5 pages, 7 figures, Invited talk at the ICTP 4th International
Conference on Perspectives in Hadronic Physics, Trieste, Italy, 12-16 May
2003. Accepted by Eur. Phys. J.
Minimal Intervention Needed for Change: Definition, Use, and Value for Improving Health and Health Research
Much research focuses on producing maximal intervention effects. This has generally not resulted in interventions being rapidly or widely adopted or seen as feasible given resources, time, and expertise constraints in the majority of real-world settings. We present a definition and key characteristics of a minimum intervention needed to produce change (MINC). To illustrate use of a MINC condition, we describe a computer-assisted, interactive minimal intervention, titled Healthy Habits, used in three different controlled studies and its effects. This minimal intervention produced modest to sizable health behavior and psychosocial improvements, depending on the intensity of personal contacts, producing larger effects at longer-term assessments. MINC comparison conditions could help to advance both health care and health research, especially comparative effectiveness research. Policy and funding implications of requiring an intervention to be demonstrated more effective than a simpler, less costly MINC alternative are discussedYe
Transfer RNA-derived small RNAs in the cancer transcriptome
The cellular lifetime includes stages such as differentiation, proliferation, division, senescence and apoptosis.These stages are driven by a strictly ordered process of transcription dynamics. Molecular disruption to RNA polymerase assembly, chromatin remodelling and transcription factor binding through to RNA editing, splicing, post-transcriptional regulation and ribosome scanning can result in significant costs arising from genome instability. Cancer development is one example of when such disruption takes place. RNA silencing is a term used to describe the effects of post-transcriptional gene silencing mediated by a diverse set of small RNA molecules. Small RNAs are crucial for regulating gene expression and microguarding genome integrity.RNA silencing studies predominantly focus on small RNAs such as microRNAs, short-interfering RNAs and piwi-interacting RNAs. We describe an emerging renewal of inter-est in a‘larger’small RNA, the transfer RNA (tRNA).Precisely generated tRNA-derived small RNAs, named tRNA halves (tiRNAs) and tRNA fragments (tRFs), have been reported to be abundant with dysregulation associated with cancer. Transfection of tiRNAs inhibits protein translation by displacing eukaryotic initiation factors from messenger RNA (mRNA) and inaugurating stress granule formation.Knockdown of an overexpressed tRF inhibits cancer cell proliferation. Recovery of lacking tRFs prevents cancer metastasis. The dual oncogenic and tumour-suppressive role is typical of functional small RNAs. We review recent reports on tiRNA and tRF discovery and biogenesis, identification and analysis from next-generation sequencing data and a mechanistic animal study to demonstrate their physiological role in cancer biology. We propose tRNA-derived small RNA-mediated RNA silencing is an innate defence mechanism to prevent oncogenic translation. We expect that cancer cells are percipient to their ablated control of transcription and attempt to prevent loss of genome control through RNA silencing
Issues in the High Resolution Acoustoelastic Measurement of Stress
The acoustoelastic measurement of stress is a topic with a rich history and the basic principles are well known [1]. In summary, one takes advantage of various nonlinearities which govern the elastic response of a solid, including but not limited to anharmonicities in interatomic forces, which lead to a stress dependence of the ultrasonic velocity. The basic idea, then is to precisely measure the velocity and to infer stress from a relation of the form V=Vo+Kσ where V is the measured velocity in the presence of a stress σ, Vo is the value that would have been observed in the absence of that stress, and K is known as the acoustoelastic constant.</p
A family history of breast cancer will not predict female early onset breast cancer in a population-based setting
ABSTRACT: BACKGROUND: An increased risk of breast cancer for relatives of breast cancer patients has been demonstrated in many studies, and having a relative diagnosed with breast cancer at an early age is an indication for breast cancer screening. This indication has been derived from estimates based on data from cancer-prone families or from BRCA1/2 mutation families, and might be biased because BRCA1/2 mutations explain only a small proportion of the familial clustering of breast cancer. The aim of the current study was to determine the predictive value of a family history of cancer with regard to early onset of female breast cancer in a population based setting. METHODS: An unselected sample of 1,987 women with and without breast cancer was studied with regard to the age of diagnosis of breast cancer. RESULTS: The risk of early-onset breast cancer was increased when there were: (1) at least 2 cases of female breast cancer in first-degree relatives (yes/no; HR at age 30: 3.09; 95% CI: 128-7.44), (2) at least 2 cases of female breast cancer in first or second-degree relatives under the age of 50 (yes/no; HR at age 30: 3.36; 95% CI: 1.12-10.08), (3) at least 1 case of female breast cancer under the age of 40 in a first- or second-degree relative (yes/no; HR at age 30: 2.06; 95% CI: 0.83-5.12) and (4) any case of bilateral breast cancer (yes/no; HR at age 30: 3.47; 95%: 1.33-9.05). The positive predictive value of having 2 or more of these characteristics was 13% for breast cancer before the age of 70, 11% for breast cancer before the age of 50, and 1% for breast cancer before the age of 30. CONCLUSION: Applying family history related criteria in an unselected population could result in the screening of many women who will not develop breast cancer at an early age
Changes in microphytobenthos fluorescence over a tidal cycle: implications for sampling designs
Intertidal microphytobenthos (MPB) are important primary producers and provide food for herbivores in soft sediments and on rocky shores. Methods of measuring MPB biomass that do not depend on the time of collection relative to the time of day or tidal conditions are important in any studies that need to compare temporal or spatial variation, effects of abiotic factors or activity of grazers. Pulse amplitude modulated (PAM) fluorometry is often used to estimate biomass of MPB because it is a rapid, non-destructive method, but it is not known how measures of fluorescence are altered by changing conditions during a period of low tide. We investigated this experimentally using in situ changes in minimal fluorescence (F) on a rocky shore and on an estuarine mudflat around Sydney (Australia), during low tides. On rocky shores, the time when samples are taken during low tide had little direct influence on measures of fluorescence as long as the substratum is dry. Wetness from wave-splash, seepage from rock pools, run-off, rainfall, etc., had large consequences for any comparisons. On soft sediments, fluorescence was decreased if the sediment dried out, as happens during low-spring tides on particularly hot and dry days. Surface water affected the response of PAM and therefore measurements used to estimate MPB, emphasising the need for care to ensure that representative sampling is done during low tide
Preservation of York Minster historic limestone by hydrophobic surface coatings
Magnesian limestone is a key construction component of many historic buildings that is under constant attack from environmental pollutants notably by oxides of sulfur via acid rain, particulate matter sulfate and gaseous SO 2 emissions. Hydrophobic surface coatings offer a potential route to protect existing stonework in cultural heritage sites, however, many available coatings act by blocking the stone microstructure, preventing it from 'breathing' and promoting mould growth and salt efflorescence. Here we report on a conformal surface modification method using self-assembled monolayers of naturally sourced free fatty acids combined with sub-monolayer fluorinated alkyl silanes to generate hydrophobic (HP) and super hydrophobic (SHP) coatings on calcite. We demonstrate the efficacy of these HP and SHP surface coatings for increasing limestone resistance to sulfation, and thus retarding gypsum formation under SO/H O and model acid rain environments. SHP treatment of 19th century stone from York Minster suppresses sulfuric acid permeation
Responses of marine benthic microalgae to elevated CO<inf>2</inf>
Increasing anthropogenic CO2 emissions to the atmosphere are causing a rise in pCO2 concentrations in the ocean surface and lowering pH. To predict the effects of these changes, we need to improve our understanding of the responses of marine primary producers since these drive biogeochemical cycles and profoundly affect the structure and function of benthic habitats. The effects of increasing CO2 levels on the colonisation of artificial substrata by microalgal assemblages (periphyton) were examined across a CO2 gradient off the volcanic island of Vulcano (NE Sicily). We show that periphyton communities altered significantly as CO2 concentrations increased. CO2 enrichment caused significant increases in chlorophyll a concentrations and in diatom abundance although we did not detect any changes in cyanobacteria. SEM analysis revealed major shifts in diatom assemblage composition as CO2 levels increased. The responses of benthic microalgae to rising anthropogenic CO2 emissions are likely to have significant ecological ramifications for coastal systems. © 2011 Springer-Verlag
Cubic-spline interpolation to estimate effects of inbreeding on milk yield in first lactation Holstein cows
Milk yield records (305d, 2X, actual milk yield) of 123,639 registered first lactation Holstein cows were used to compare linear regression (y = β0 + β1X + e), quadratic regression, (y = β0 + β1X + β2X2 + e) cubic regression (y = β0 + β1X + β2X2 + β3X3 +e) and fixed factor models, with cubic-spline interpolation models, for estimating the effects of inbreeding on milk yield. Ten animal models, all with herd-year-season of calving as fixed effect, were compared using the Akaike corrected-Information Criterion (AICc). The cubic-spline interpolation model with seven knots had the lowest AICc, whereas for all those labeled as “traditional”, AICc was higher than the best model. Results from fitting inbreeding using a cubic-spline with seven knots were compared to results from fitting inbreeding as a linear covariate or as a fixed factor with seven levels. Estimates of inbreeding effects were not significantly different between the cubic-spline model and the fixed factor model, but were significantly different from the linear regression model. Milk yield decreased significantly at inbreeding levels greater than 9%. Variance component estimates were similar for the three models. Ranking of the top 100 sires with daughter records remained unaffected by the model used
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