10 research outputs found
Feeding mechanism and capture success of European whitefish (Coregonus lavaretus L.) larvae
Feeding success is a key factor for larval growth and survival, and is highly dependent on small-scale processes which occur during the predator-prey interaction. We studied the feeding mechanisms involved in the capture success of the European whitefish (Coregonus lavaretus) larvae using video recordings. The successful predatory sequence of this species consists of the following 5 events: encounter, pursuit (including fixation), strike, capture and ingestion. C. lavaretus larvae can exhibit an “S” shaped posture and always strikes on its prey from beyond. The mean fixation distance for wild larvae was 1.75 ± 0.71 mm and for reared larvae was 1.65 ± 0.76 mm. This distance was significantly different between failed and successful snaps, and seemed to be an important parameter to the capture success of C. lavaretus larvae. The analysis of the complexity in predator’s swimming path showed that more convoluted approaches are less likely to lead to a fruitful att
Effect of heat treatment on the migration behaviour of Sr and Ag CO-implanted in glassy carbon
The effect of annealing on the diffusion of silver, silver and strontium co-implanted in glassy carbon was investigated. Glassy carbon samples were implanted with 360 keV Ag ions at room temperature. The RBS profile showed that Fickian diffusion of Ag in glassy carbon is only observed at temperatures ranging from 500 °C–600 °C. At higher annealing temperatures, there was a significant loss of Ag and no Ag was retained in glassy carbon at 700 °C. Glassy carbon samples were also co-implanted with Ag and Sr. The diffusion behaviour of Ag when co-implanted with Sr was similar to that of the singly implanted Ag sample. However, the introduction of Sr into the glassy carbon matrix assisted in the retainment of the Ag ions. The co-implantation of Ag and Sr resulted in a change in the diffusion behaviour of Sr in glassy carbon. The implantation of Ag with Sr prevented the movement of Sr deeper into the bulk of the glassy carbon. The non-movement of Sr into the bulk of the glassy carbon was attributed to the increase of radiation damage near the surface of the glassy carbon making diffusion of Sr towards the surface of glassy carbon an easier choice.The National Research Foundation, South Africa and the TWAS-DFG Co-operation Programme.http://www.journals.elsevier.com/vacuumhj2021Physic
The global burden of cancer attributable to risk factors, 2010–19: a systematic analysis for the Global Burden of Disease Study 2019
BACKGROUND: Understanding the magnitude of cancer burden attributable to potentially modifiable risk factors is crucial for development of effective prevention and mitigation strategies. We analysed results from the Global Burden of Diseases, Injuries, and Risk Factors Study (GBD) 2019 to inform cancer control planning efforts globally. METHODS: The GBD 2019 comparative risk assessment framework was used to estimate cancer burden attributable to behavioural, environmental and occupational, and metabolic risk factors. A total of 82 risk–outcome pairs were included on the basis of the World Cancer Research Fund criteria. Estimated cancer deaths and disability-adjusted life-years (DALYs) in 2019 and change in these measures between 2010 and 2019 are presented. FINDINGS: Globally, in 2019, the risk factors included in this analysis accounted for 4·45 million (95% uncertainty interval 4·01–4·94) deaths and 105 million (95·0–116) DALYs for both sexes combined, representing 44·4% (41·3–48·4) of all cancer deaths and 42·0% (39·1–45·6) of all DALYs. There were 2·88 million (2·60–3·18) risk-attributable cancer deaths in males (50·6% [47·8–54·1] of all male cancer deaths) and 1·58 million (1·36–1·84) risk-attributable cancer deaths in females (36·3% [32·5–41·3] of all female cancer deaths). The leading risk factors at the most detailed level globally for risk-attributable cancer deaths and DALYs in 2019 for both sexes combined were smoking, followed by alcohol use and high BMI. Risk-attributable cancer burden varied by world region and Socio-demographic Index (SDI), with smoking, unsafe sex, and alcohol use being the three leading risk factors for risk-attributable cancer DALYs in low SDI locations in 2019, whereas DALYs in high SDI locations mirrored the top three global risk factor rankings. From 2010 to 2019, global risk-attributable cancer deaths increased by 20·4% (12·6–28·4) and DALYs by 16·8% (8·8–25·0), with the greatest percentage increase in metabolic risks (34·7% [27·9–42·8] and 33·3% [25·8–42·0]). INTERPRETATION: The leading risk factors contributing to global cancer burden in 2019 were behavioural, whereas metabolic risk factors saw the largest increases between 2010 and 2019. Reducing exposure to these modifiable risk factors would decrease cancer mortality and DALY rates worldwide, and policies should be tailored appropriately to local cancer risk factor burden
Heavy Metals Content of Commercial Inorganic Fertilizers Used in the Kingdom of Saudi Arabia
In recent years much concern has been given to toxic heavy metals, which enter the human food chain. Application of inorganic fertilizers is considered one of the potential routes of such entry, in this work 74 samples of commercial fertilizers marketed in the Kingdom of Saudi Arabia were analyzed for their heavy metal concentrations. Fertilizer samples included 20 samples of phosphatic fertilizers [monoammonium phosphate (MAP), diammonium phosphate (DAP) and triple superphosphate (TSP)], 11 samples of liquid fertilizers. 31 samples of water-soluble multiple nutrient fertilizers (WSMF) and 12 samples of solid multiple nutrient fertilizers (SMNF). Concentrations of heavy metals varied according to the type of fertilizer and the tested metal; Cr levels were the highest and Co was the lowest. Results revealed that Cd ranged from < l to 36.8 mg.kg-1, with a median of 33.2 mg.kg-1 for the phosphatic fertilizers, 9.5 mg.kg-1 for the liquid fertilizers, 19.7 for the SMNF, and 2.9 mg.kg-1 for the WSMF. The median values of Pb, Ni, Co and Cr in the phosphatic fertilizers were 14.3, 72.1, 1 1.8 and 249.3 mg.kg-1, respectively. However, the corresponding median values of these elements, in the liquid fertilizers, were 9.9, 15.6, 11.2 and 64.0 mg.kg-1 and 15.3, 43.0, 12.5 and 170.7 mg.kg-1 in the SMNF. The median contents of three heavy metals in the WSMF samples were 9.8 mg.kg-1 for Pb, 5.6 mg.kg-1 for Co. and 7.4 mg.kg-1 for Ni. The Cd. Co. Cr and Ni concentrations were lower than the tolerance limits for heavy metal addition (Cd 100 mg.kg-1, Cr, 100 mg.kg-1 and Ni, 50 mg.kg-1), and they were in a range similar to those found internationally. It is estimated that the application of an average dose of 80 kg P ha-1 annually in Saudi Arabia, contributes 13 g of Cd ha-1 to the soil
Fabrication and evaluation of aptamer-conjugated paclitaxel-loaded magnetic nanoparticles for targeted therapy on breast cancer cells
Targeted drug delivery vehicles make it possible to deliver anti-cancer drugs to the cells or tissues of interest. Aptamers are peptide or oligonucleotide molecules that can serve as targeting elements of drug carriers. In the current study, we evaluated the capacity of an aptamer-based drug carrier to deliver Paclitaxel (PTX) to cancer cells. After being synthesized, SPIONs@PTX-SYL3C aptamer was characterized using different methods, including differential light scattering (DLS), infrared spectroscopy (FTIR), Transmission electron microscopy (TEM), X-ray diffraction (XRD), Thermal gravimetric analysis (TGA), and vibrating sample magnetometer (VSM). Encapsulation efficiency (EE) and loading efficiency (LE) were also evaluated. The carrier was applied on 4T1, MCF 7, and MCF-10A breast cell lines to evaluate its drug delivery potency and specificity. EE and LE were calculated to be 77.6 and 7.76, respectively. MTT results revealed that aptameric SPIONs@PTX was more toxic than non-aptameric SPIONs@PTX. Flowcytometry analysis and DAPI staining confirmed that SPIONs@PTX-Aptamer had higher cell internalization rate when compared to non-targeted SPIONs@PTX. Our results indicate that aptamer-conjugated SPIONs@PTX has a good capacity in recognizing its target cells and inhibiting their growth and division. © 2021, The Author(s), under exclusive licence to Springer Nature B.V. part of Springer Nature
Distribution and economic feasibility of the production of the calanoid copepod Acartia tonsa
Validation d'un questionnaire d'addiction en milieu scolaire
The aim: was to develop and validate an addictive behaviors screening tool in school children. Methodology :A cross sectional study including a self administrated 223 item questionnaire developed in Arabic language. The questionnaire included identification of the student and seven life domains: school, family, addiction, relationships with peers, leisure and well being, risky behaviors and personality traits. N = 854 high school children, of Monastir City. Results :the questionnaire Alpha Cronbach's Coefficient ranged between 0.3 and 0.8. Only items with a coefficient higher than 0.6 were maintained in the final version. The time reliability by using the Bland and Altman method 15 days after the first measure showed a Pearson's coefficient of 0.81. Validity evaluated by principal components analysis led to 3 independent factors consisting respectively in 20, 4 and 3 well correlated items: family, school and risky behaviors. Conclusion: validated version of the questionnaire consisted in 102 items, easy to read and understand. This version doesn't require much time to be filled in and takes into consideration cultural particularities of the school children of Monastir. It could be considered as an interesting tool for both the assessment and the prevention of addictive behaviors in school.SCOPUS: ar.jinfo:eu-repo/semantics/publishe
Improved Mechanical Properties and Theoretical Prediction of Young’s Modulus of Polylactide Composites Reinforced with Sisal Fibers
National, sub-national, and risk-attributed burden of thyroid cancer in Iran from 1990 to 2019
An updated exploration of the burden of thyroid cancer across a country is always required for making correct decisions. The objective of this study is to present the thyroid cancer burden and attributed burden to the high Body Mass Index (BMI) in Iran at national and sub-national levels from 1990 to 2019. The data was obtained from the GBD 2019 study estimates. To explain the pattern of changes in incidence from 1990 to 2019, decomposition analysis was conducted. Besides, the attribution of high BMI in the thyroid cancer DALYs and deaths were obtained. The age-standardized incidence rate of thyroid cancer was 1.57 (95 UI: 1.33�1.86) in 1990 and increased 131 (53�191) until 2019. The age-standardized prevalence rate of thyroid cancer was 30.19 (18.75�34.55) in 2019 which increased 164 (77�246) from 11.44 (9.38�13.85) in 1990. In 2019, the death rate, and Disability-adjusted life years of thyroid cancer was 0.49 (0.36�0.53), and 13.16 (8.93�14.62), respectively. These numbers also increased since 1990. The DALYs and deaths attributable to high BMI was 1.91 (0.95�3.11) and 0.07 (0.04�0.11), respectively. The thyroid cancer burden and high BMI attributed burden has increased from 1990 to 2019 in Iran. This study and similar studies� results can be used for accurate resource allocation for efficient management and all potential risks� modification for thyroid cancer with a cost-conscious view. © 2022, The Author(s)