8,980 research outputs found
Cytotoxic Potential on Breast Cancer Cells Using Selected Forest Species Found in Malaysia
In vitro studies were carried out to evaluate the cytotoxic potential of three selected forest herbaceous species: Tectaria singaporeana (TS), Blechnum orientale (BO) and Tacca integrifolia (TCI). Methanol/methylene chloride extracts of three plant parts viz. leaves, roots and stems were assessed for their cytotoxic potential against human breast cancer cells (MCF-7wt.). Screening of these extracts was done using the microculture, followed by tetrazolium assay after a period of 72 h. There were significant differences between different parts of plants and dilution levels in terms of cytotoxicity, with roots and concentration of 100 μg mL-1 showing the highest cell mortality of 19.58 and 36.59%, respectively. However, the leaves and the stems of all three plant species did not induce any cytotoxic activity on the cells. Overall, the most promising material (IC50 <100 μg mL-1) were the methanolic extracts from the roots of all three plants. Tectaria singaporeana showed the highest cytotoxic potential with an IC50 value of 28.57 ± 11.74 μg mL-1 followed by Blechnum orientale, 32.07 ± 7.85 μg mL-1 and Tacca integrifolia, 95.03 ± 17.49 μg mL-1. From this study, the extracts of these plants may prove to be useful in cancer treatment and prevention
Assessment of the Water Quality of the Oti River in Ghana
Oti river, an important tributary of the Volta lake in Ghana, was chosen as a case study to investigate the variations in the quality of itswater at different locations. This was necessitated by the people’s reliance on the river for their domestic and agricultural water use.Composite water samples drawn from some sections of the Oti river were analysed in the laboratory for certain parameters to enableassessment of water quality. The observed results of the laboratory analyses are compared with the 2003 Ghana Raw Water Criteriaand Guidelines for domestic use. The results indicated that turbidity, total iron, faecal coliforms and total coliforms were above thelimits set out by the 2003 Ghana Raw Water Criteria and Guidelines for domestic use. Thus, the water from Oti river was consideredunsuitable for direct human consumption at the sampled locations. Using the Water Quality Index (WQI) Calculator 1.0, the WQI forOti river was calculated to be 39.3. The WQI indicates that water quality in the Oti river was poor. This implies that the water qualityis almost always threatened or impaired; conditions usually depart from natural or desirable levels. Public awareness with respect tothe need to boil and/or filter the water before drinking is called for. Sanitary facilities to control river pollution and appropriate watertreatments techniques are required in the area to improve the welfare of the riparian dwellers
Exploring Theories of Victimization Using a Mathematical Model of Burglary
Research concerned with burglary indicates that it is clustered not only at places but also in time. Some homes are victimized repeatedly, and the risk to neighbors of victimized homes is temporarily elevated. The latter type of burglary is referred to as a near repeat. Two theories have been proposed to explain observed patterns. The boost hypothesis states that risk is elevated following an event reflecting offender foraging activity. The flag hypothesis, on the other hand, suggests that time-stable variation in risk provides an explanation where data for populations with different risks are analyzed in the aggregate. To examine this, the authors specify a series of discrete mathematical models of urban residential burglary and examine their outcomes using stochastic agent-based simulations. Results suggest that variation in risk alone cannot explain patterns of exact and near repeats, but that models which also include a boost component show good qualitative agreement with published findings
Maximum static inspiratory and expiratory pressures with different lung volumes
BACKGROUND: Maximum pressures developed by the respiratory muscles can indicate the health of the respiratory system, help to determine maximum respiratory flow rates, and contribute to respiratory power development. Past measurements of maximum pressures have been found to be inadequate for inclusion in some exercise models involving respiration. METHODS: Maximum inspiratory and expiratory airway pressures were measured over a range of lung volumes in 29 female and 19 male adults. A commercial bell spirometry system was programmed to occlude airflow at nine target lung volumes ranging from 10% to 90% of vital capacity. RESULTS: In women, maximum expiratory pressure increased with volume from 39 to 61 cmH(2)O and maximum inspiratory pressure decreased with volume from 66 to 28 cmH(2)O. In men, maximum expiratory pressure increased with volume from 63 to 97 cmH(2)O and maximum inspiratory pressure decreased with volume from 97 to 39 cmH(2)O. Equations describing pressures for both sexes are: P(e)/P(max )= 0.1426 Ln( %VC) + 0.3402 R(2 )= 0.95 P(i)/P(max )= 0.234 Ln(100 - %VC) - 0.0828 R(2 = )0.96 CONCLUSION: These results were found to be consistent with values and trends obtained by other authors. Regression equations may be suitable for respiratory mechanics models
Response to novel objects and foraging tasks by common marmoset (Callithrix Jacchus) female Pairs
Many studies have shown that environmental enrichment can significantly improve the psychological well-being of captive primates, increasing the occurrence of explorative behavior and thus reducing boredom. The response of primates to enrichment devices may be affected by many factors such as species, sex, age, personality and social context. Environmental enrichment is particularly important for social primates living in unnatural social groupings (i.e. same-sex pairs or singly housed animals), who have very few, or no, benefits from the presence of social companions in addition to all the problems related to captivity (e.g. increased inactivity). This study analyses the effects of enrichment devices (i.e. novel objects and foraging tasks) on the behavior of common marmoset (Callithrix jacchus) female pairs, a species that usually lives in family groups. It aims to determine which aspects of an enrichment device are more likely to elicit explorative behaviors, and how aggressive and stress-related behaviors are affected by its presence. Overall, the marmosets explored foraging tasks significantly longer than novel objects. The type of object, which varied in size, shape and aural responsiveness (i.e. they made a noise when the monkey touched them), did not affect the response of the monkeys, but they explored objects that were placed higher in the enclosure more than those placed lower down.Younger monkeys were more attracted to the enrichment devices than the older ones. Finally, stress-related behavior (i.e. scratching) significantly decreased when the monkeys were presented with the objects; aggressive behavior as unaffected. This study supports the importance of environmental enrichment for captive primates and shows that in marmosets its effectiveness strongly depends upon the height of the device in the enclosure and the presence of hidden food. The findings can be explained ifone considers the foraging behavior of wild common marmosets. Broader applications for the research findings are suggested in relation to enrichment
Identifying critically important vascular access outcomes for trials in haemodialysis : an international survey with patients, caregivers and health professionals
BACKGROUND:
Vascular access outcomes reported across haemodialysis (HD) trials are numerous, heterogeneous and not always relevant to patients and clinicians. This study aimed to identify critically important vascular access outcomes.
METHOD:
Outcomes derived from a systematic review, multi-disciplinary expert panel and patient input were included in a multilanguage online survey. Participants rated the absolute importance of outcomes using a 9-point Likert scale (7-9 being critically important). The relative importance was determined by a best-worst scale using multinomial logistic regression. Open text responses were analysed thematically.
RESULTS:
The survey was completed by 873 participants [224 (26%) patients/caregivers and 649 (74%) health professionals] from 58 countries. Vascular access function was considered the most important outcome (mean score 7.8 for patients and caregivers/8.5 for health professionals, with 85%/95% rating it critically important, and top ranked on best-worst scale), followed by infection (mean 7.4/8.2, 79%/92% rating it critically important, second rank on best-worst scale). Health professionals rated all outcomes of equal or higher importance than patients/caregivers, except for aneurysms. We identified six themes: necessity for HD, applicability across vascular access types, frequency and severity of debilitation, minimizing the risk of hospitalization and death, optimizing technical competence and adherence to best practice and direct impact on appearance and lifestyle.
CONCLUSIONS:
Vascular access function was the most critically important outcome among patients/caregivers and health professionals. Consistent reporting of this outcome across trials in HD will strengthen their value in supporting vascular access practice and shared decision making in patients requiring HD
Ergodic Jacobi matrices and conformal maps
We study structural properties of the Lyapunov exponent and the
density of states for ergodic (or just invariant) Jacobi matrices in a
general framework. In this analysis, a central role is played by the function
as a conformal map between certain domains. This idea goes
back to Marchenko and Ostrovskii, who used this device in their analysis of the
periodic problem
PMS52 PREFERENCES OVER BENEFITS AND RISKS ASSOCIATED WITH THE USE OF NSAIDS: EVIDENCE FROM PATIENTS DIAGNOSED WITH OSTEOARTHRITIS (OA) IN UK
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