46 research outputs found
A Mixed-Methods Normative Case Study of Undergraduate Students\u27 Attitudes and Behaviors towards Influenza and Vaccination in the Post-2009 Influenza A(H1N1) Pandemic Era
The 2009 influenza A(H1N1) pandemic caused high morbidity and mortality in young adults, prompting recommendation for extension of routine annual flu vaccination to all healthy adults younger than 65 years old who do not have contraindications. But despite this recommendation, flu vaccination rates remained suboptimal in university students. The purpose of this study was to determine (a) how undergraduate students perceive influenza as a risk in light of risk information communicated by authoritative bodies; (b) where they seek advice and access educational information about influenza and methods of flu protection; (c) what attitudes they hold towards influenza and vaccination; and (d) when and why they engage in risk response behavior? This social science study, which involved 303 undergraduate students, included a written questionnaire, infographics, and interviews. Four theories (cultural theory of risk perception; structural constructivism; symbolic interactionism; and applied phronesis) were used to interpret the data.
The coding of students’ answers allowed for the identification of ten themes, such as authoritative powers, identity, beliefs, infoglut, and reacting to risk. Students ranked influenza at the lower end of various risks discussed, considered their personal doctors as the most trusted source for influenza information, and were against mandatory flu vaccination. Although 48.6% of students self-reported flu vaccination during the 2014-2015 influenza season, vaccination was inconsistent in prior years. Perceived good health, vaccine complacency, a busy class schedule, vaccination confidence and convenience, were identified as factors contributing to vaccine hesitancy. Students developed a habit of using non-pharmaceutical flu interventions during their middle/high schools years, which was seen as a reason why flu vaccination was not their primary choice to protect against influenza. Students reported that they would seek information pieces that matter to them in case of a major flu outbreak close to or on campus. However, infoglut would make it difficult to them to find the right information online. This study suggests a need for a stronger focus of influenza education on undergraduate students by considering the needs and wants of these young adults. Numerous suggestions were made for how authorities, especially the university, can play here a stronger role
Essentials of Epidemiology in Public Health
Review of: Essentials of Epidemiology in Public Health. Ann Aschengrau and George R. Seage III. Burlington, MA: Jones and Bartlett Learning, 2014, 534 pp., $111.95. ISBN: 978-1-284-02891-
Effects of a saponin fraction extracted from Trigonella foenum-graecum L. and two commercially available saponins on sex ratio and gonad histology of Nile tilapa fry, Oreochromis niloticus (L.)
Over three million tonnes (t) of tilapia, mostly Nile tilapia (Oreochromis niloticus, L.), are produced annually making it the second most abundantly produced freshwater fish (FAO, 2010). Tilapia are mouthbreeders that often produce stunted populations under pond conditions; one means of prevention is to produce all-male fish with the additional advantage that males usually grow faster than females. All-male populations can be achieved by supplementing feed with androgens such as 17-α-Methyltestosterone (MT) during days 10–25 post-hatch (Pandian and Sheela, 1995). However, MT is considered to be carcinogenic (Velazquez and Alter, 2004), and Hulak et al. (2008) also showed that effluents of systems in which carp were fed diets containing MT caused masculinization of female fish. Furthermore, in aquaculture the application of hormones to fish destined for human consumption is prohibited in the European Union under directive 96/22/EC, article 5, which also prohibits import of animal products produced with hormones.
Kwon et al. (2000) showed that Fadrozole, a non-steroidal compound, caused masculinization in tilapia by inhibiting aromatase, which is the enzyme responsible for the conversion of endogenous androgens to estrogens. Steinbronn et al. (2004) were able to show that a dose of 2000 ppm Quillaja saponins (Sigma S-2149) inhibited reproduction of tilapia after dietary application for 32 days to first-feeding fry, suggesting saponins as a possible alternative to MT. These secondary plant compounds consist of either a steroid or triterpenoid basic structure (aglycone or sapogenin) plus one or more sugar side chains (Francis et al., 2002a).
In a previous experiment a saponin fraction from the soapbark tree (Quillaja saponaria M.) inhibited aromatase in vitro (Golan et al., 2008). The fenugreek plant (Trigonella foenum-graecum L), widely cultivated in the Middle East and Asia, also has a high saponin content. The experiment was therefore conducted to test whether saponin fractions from Q. saponaria and from T. foenum-graecum were able to influence the sex ratio and gonad histology of Nile tilapia
Effects of Moringa oleifera Lam. dietary seed protein extracts on growth, nutrient utilization and blood parameters in common carp (Cyprinus carpio, L.) and Nile tilapia (Oreochromis niloticus, L.)
The drumstick tree, Moringa oleifera, is a multi-purpose plant showing several beneficial effects, depending on plant part origin. The seeds for example show potential anti-biotic activity against certain pathogenic bacteria species. Furthermore they can be used for water purification since they contain specific proteins with coagulation properties. In these experiments we tested the effects of dietary M. oleifera seed protein extracts (MPE) on growth performance, nutrient utilization and blood parameters of the common carp, Cyprinus carpio, and on Nile tilapia, Oreochromis niloticus, two of the most important freshwater aquaculture fish species. The MPE was added in three concentrations (carp: 200, 400 and 600 ppm; tilapia: 400, 800 1200 ppm) to the diets and fed, beside a negative control for eight weeks.
During this period carp grew from initially 25.1 g to final body masses of 95.9 g (control), 97.2 g (200 ppm), 100.2 g (400 ppm) and 100.3 g (600 ppm) and tilapia from initially 5.49 g to final body masses of 46.6 g (control), 48.0 g (400 ppm), 42.4 g (800 ppm) and 49.4 g (1200 ppm). The feed conversion was best for carp fed with 400 and 600 ppm MPE (1.08 kg feed/kg body mass gain) and for tilapia fed 400 ppm MPE (0.84 kg feed/kg body mass gain). the best protein conversions in carp was achieved by the 600 ppm treatment (2.40 kg body mass gain/kg protein fed) while in tilapia the 400 ppm MPE treated group showed the highest protein conversion (3.00 kg body mass gain/kg protein fed).
Higher supplementation levels with MPE resulted in higher red blood cell counts (RBC) in both species accompanied by increased hemoglobin concentrations and hematocrit in tilapia but not carp and in higher white blood cell counts in carp but not in tilapia.
These results show that seed protein extracts from Moringa oleifera have potential as growth promoters in two of the world's most important freshwater aquaculture species by improving growth and nutrient utilization
Effects of saponin fractions from fenugreek and the soap bark tree in the diet on performance of Nile tilapia, Oreochromis niloticus (L.)
Saponins are generally regarded as anti-nutritional factors in aquaculture diets. However, previous experiments have shown that low dietary levels of saponins derived from Quillaja saponaria Molina do have growth promoting effects on common carp and Nile tilapia. Based on these experiments, we conducted an experiment in which we fed eluated saponin fractions from Q. saponaria and Trigonella foenum-graecum L. (fenugreek) to Nile tilapia in a respirometric system allowing for continuous measurement of oxygen consumption. Saponins were eluated with consecutive methanol/water concentrations (v/v, 40/60, 60/40, 80/20) resulting in three different eluates for each plant. Fractions chosen were the 80% methanol eluate from Q. saponaria (80QS) and all three eluates from T. foenum-graecum (40TS, 60TS and 80TS). Three fish each were fed with low levels (150 mg kg-1 diet) of saponins in the diet and a control diet without saponins. Growth, feed and nutrient utilization, proximate composition, oxygen consumption and metabolic performance were evaluated.
The fish grew between 224% (40TS) and 266% (Control) over the eight week period. Feed conversion ratios were between 0.94 (80TS) and 1.15 (40TS) and protein efficiency ratios between 2.54 (80TS) and 2.16 (40TS). Due to low sample sizes, no statistical differences were found between control fish and saponin fed fish. However, numerically one of the tested saponin fractions (40TS) showed inferior performance (Table 1).
It is concluded that the tested saponins in the tested concentrations are no potential growth promoter for Nile tilapia. On the contrary, one fraction appears to be a growth inhibitor
Fluorescence in situ hybridisation analysis of chromosomal aberrations in gastric tissue: the potential involvement of Helicobacter pylori
In this series of experiments, a novel protocol was developed whereby gastric cells were collected using endoscopic cytology brush techniques, and prepared, such that interphase fluorescence in situ hybridization (FISH) could be performed. In total, 80 distinct histological samples from 37 patients were studied using four chromosome probes (over 32 000 cells analysed). Studies have previously identified abnormalities of these four chromosomes in upper GI tumours. Using premalignant tissues, we aimed to determine how early in Correa's pathway to gastric cancer these chromosome abnormalities occurred. Aneuploidy of chromosomes 4, 8, 20 and 17(p53) was detected in histologically normal gastric mucosa, as well as in gastritis, intestinal metaplasia, dysplasia and cancer samples. The levels of aneuploidy increased as disease severity increased. Amplification of chromosome 4 and chromosome 20, and deletion of chromosome 17(p53) were the more common findings. Hence, a role for these abnormalities may exist in the initiation of, and the progression to, gastric cancer. Helicobactor pylori infection was determined in premalignant tissue using histological analysis and PCR technology. Detection rates were comparable. PCR was used to subtype H. pylori for CagA status. The amplification of chromosome 4 in gastric tissue was significantly more prevalent in H. pylori-positive patients (n=7) compared to H. pylori-negative patients (n=11), possibly reflecting a role for chromosome 4 amplification in H. pylori-induced gastric cancer. The more virulent CagA strain of H. pylori was associated with increased disease pathology and chromosomal abnormalities, although numbers were small (CagA+ n=3, CagA− n=4). Finally, in vitro work demonstrated that the aneuploidy induced in a human cell line after exposure to the reactive oxygen species (ROS) hydrogen peroxide was similar to that already shown in the gastric cancer pathway, and may further strengthen the hypothesis that H. pylori causes gastric cancer progression via an ROS-mediated mechanism
Tactual perception: a review of experimental variables and procedures
This paper reviews literature on tactual perception. Throughout this review we will highlight some of the most relevant variables in touch literature: interaction between touch and other senses; type of stimuli, from abstract stimuli such as vibrations, to two- and three-dimensional stimuli, also considering concrete stimuli such as the relation between familiar and unfamiliar stimuli or the haptic perception of faces; type of participants, separating studies with blind participants, studies with children and adults, and an analysis of sex differences in performance; and finally, type of tactile exploration, considering conditions of active and passive touch, the relevance of movement in touch and the relation between exploration and time. This review intends to present an organised overview of the main variables in touch experiments, attending to the main findings described in literature, to guide the design of future works on tactual perception and memory.This work was funded by the Portuguese “Foundation for Science and Technology” through PhD scholarship SFRH/BD/35918/2007
Validierung toxikologischer Pruefparameter an Tetrahymena Membranfunktionen, Chemotaxis, Rotation im elektrischen Drehfeld
The purpose of this project was to validate Tetrahymena as a test organism for ecotoxicological risk assessment. The first step in this validation procedure was to select suitable candidate tests with regard to sensitivity, standardization and ecological relevance. 5 aniline derivatives were tested for their effects on 11 different physiological, biochemical and behavioural endpoints. The three testsystems proliferation rate, 48h population density and the chemosensory response were selected and further validated using a heterogeneous set of 45 existing chemicals randomly chosen from EINECS. In this second step of the validation procedure almost identical results were obtained with both growth parameters as cytotoxicological endpoints. No significant correlation exists between the growth assays and the chemosensory response, indicating a different underlying mechanism of toxic interactions. The combination of the common cytotoxic endpoint growth with a behavioural characteristic comprises a complementary set of sublethal endpoints for ecotoxicological screening purposes. Data from recommended standard aquatic toxicity tests cannot predict hazards for Tetrahymena. However a highly significant correlation was found between the proliferation inhibition of mammalian cell cultures (CHO) and Tetrahymena. The implemenation of a protozoan test would supply toxicological data for an ubiquitous and functional important group in the ecological food web and would help to reduce higher animal testingSIGLEAvailable from TIB Hannover: RN 8908(93-074) / FIZ - Fachinformationszzentrum Karlsruhe / TIB - Technische InformationsbibliothekBundesministerium fuer Umwelt, Naturschutz und Reaktorsicherheit, Bonn (Germany)DEGerman