Effect of sublethal concentration of anionic detergent on feeding behavior of Daphnia magna

Daphnia magna was exposed to the concentration 1/4, 1/2 and 2/3 LC50 and LC50 of 6 anionic detergents to determine the effect of these detergents on filtration and ingestion rates. Two dish washing liquid in terms of active ingredient as linear alkyl benzene sulfonate each 17% but one with DE ethanolamine (5%) and lauric acid ethanolamid (2%) as its component part, including washing machine powder, two kind washing powders and a shampoo, which the last four active ingredients content were 10%, 19%, 20 - 22%, 12% respectively exposed to the test organism. The experiments were performed with unicellular algae Chlorella vulgaris in a density of 10 mg/l as a feed to Daphnia magna. Relatively simple short term bioassay methods were developed to measure the filtration and ingestion (5 hours) rate. The effective concentration at which feeding and ingestion rates were reduced to 50% of those in controls (LC50) was calculated for six detergents. These values were 9.87, 4.37, 22.8, 33.17, 21.81, 35.26 mg/l for feeding rate and 9.75, 5.67, 19.9, 44.26, 23.94, 43.41 mg/l for ingestion rates respectively. The results indicated the liquid detergents exerted high reduction in feeding and ingestion rates and the one with the ingredients of DE-ethanolamine (5%) and lauric acid (2%) influenced higher in reduction of feeding and ingestion rate. The effect of washing powder were greater to the feeding behaviour in comparison with washing machine powder, the shampoo observed with many limited effect on filtration and ingestion rates

The impact of detergents on the mortality of Daphnia magna

This study aimed to examine the impact of detergents on the mortality rate of Daphnia magna. For this purpose, we exposed one-day-old Daphnia magna for 24 hours to six nationwide consumed detergents, comprising of two dishwasher detergents, three washing-powders (one for hand wash and two for washing-machines) and one shampoo. The result of our study revealed that the dishwasher detergents had the greatest impact on the Daphnia magna mortality. One of these detergents containing 17% Linear Alkyl Benzene Sulfonate, 5% Deethanolamine and 2% Lauric acid Ethanolamid was the most lethal detergent in this study. The permissible concentration and the EC50 of this dishwasher detergent is 4.7 mg/1 and 7.5 mg/1, respectively. Studies in 1993 indicated that the concentration of Linear Alkyl Benzene Sulfonate in some part of Anzali Lagoon had been 8.9 mg/1, which is above the permissible level. Among the washing-powders, the washing-machine powders were the least lethal detergents for Daphnia magna (EC50 = 50.9), while the only tested shampoo was the least lethal (EC50 = 52) detergent for Daphnia magna correlation coefficient between logarithm of concentration of the detergents and the mortality rate of Daphnia magna were 79% - 99%

An investigation on the effects of varying calcium concentrations on the growth and biomass of Chlorella vulgaris

The likely effects of varying Calcium concentrations on the growth and biomass production of Chlorella vulgaris algae have been studied during 2003-2004 in the Bony Fish Research Centre in Guilan Province, Iran. We cultured pure Chlorella vulgaris stocks in Zinder media applying seven Calcium concentrations as treatments, 3 replicates for each treatment and one control. The laboratory experiments lasted 96 hours during which the temperature and light intensity were kept at 25±2 degrees centigrade and 3500±350 lux respectively. Spectrophotometer assessment of the samples at a wavelength of 750 nm and visual counting at the start and end of the experiments were carried out to assess the growth and biomass of the green algae. Statistical analysis of the results in SPSS software showed the effective Calcium concentration to be between 0.1 to 15 mg/l while the highest growth of the algae was reached at 2.8 mg/l where as in control group (Z-8±N) the amounts was 9.2 mg/l. Density of the algae was 17575675 cells per milliliter of the culture medium and the absorption rate was 0.542 and algae biomass was 17676 cells per milliliter. Calcium concentrations above these rates can have a negative effect on the growth and biomass production of the algae

Checklist of phytoplankton taxa in the Iranian waters of the Caspian Sea

Phytoplankton taxa composition of the Caspian Sea were evaluated by using samples collected at 12 stations along the Iranian coast of the Caspian Sea between 1996 and 2010. This study identified 158 phytoplankton species consisted of diatoms (70 species), dinoflagellates (23 species), chlorophytes (29 species), cyanophytes (31 species), and euglenoids (5 species). The dominant species were the diatoms Thalassionema nitzschioides, Dactyliosolen fragilissimus, the dinoflagellate Prorocentrum cordatum, and the cyanophyte of genus Oscillatoria. The average species diversity index of phytoplankton community was 1.88 as recorded in this study. There were main changes in phytoplankton composition as compared with previous study. It could be related to the severe human activities and difference in sampling strategies

Phytoplankton population structure of the Anzali wetland (2010 and 2011)

Phytoplankton groups are very important producers in the Anzali wetland having a significant role in the quality and need to be constantly studied in term of their sequence and density. This survey was conducted at 6 stations between March 2011 and February 2012. According to the results, 67 different genera (22 Bacillariophyta, 26 Chlorophyta, 9 Cyanobacteria, 5 Cryptophyta, 1 Euglenophyta, 2 Chrysophyta, 1Dinoflgellata and 1 Xanthophyta) were identified. Most observed in Sorkhankol and Karkan stations with the annual average of 24.4±5.6 and 20.4± 5.4 cells/ liter respectively. The Bacillariophyta particularly Cyclotella was dominant in all of the stations, but high abundance of Cyanobacteria in Karkan station from July to mid-October caused the annual average of this phylum to be more than Bacillariophyta. The highest and lowest phytoplankton abundances were observed in September and December, respectively. The number of phytoplankton genera and diversity in this study were less than previous studies

Quantum-dot-spin single-photon interface

Using background-free detection of spin-state-dependent resonance fluorescence from a single-electron charged quantum dot with an efficiency of 0:1%, we realize a single spin-photon interface where the detection of a scattered photon with 300 picosecond time resolution projects the quantum dot spin to a definite spin eigenstate with fidelity exceeding 99%. The bunching of resonantly scattered photons reveals information about electron spin dynamics. High-fidelity fast spin-state initialization heralded by a single photon enables the realization of quantum information processing tasks such as non-deterministic distant spin entanglement. Given that we could suppress the measurement back-action to well below the natural spin-flip rate, realization of a quantum non-demolition measurement of a single spin could be achieved by increasing the fluorescence collection efficiency by a factor exceeding 20 using a photonic nanostructure

The effect of zinc and iron supplementation on the status of iron and zinc in the primary schoolchildren

چکیده: زمینه و هدف: کمبود ریزمغذی ها یکی از مهمترین مشکلات بهداشتی جهان است. در بین ریزمغذی ها کمبود آهن و روی شیوع بیشتری داشته و از اهمیت زیادی برخوردار است. هدف از این مطالعه مقایسه تأثیر مکمل یاری آهن و روی به تنهایی و همراه با هم بر وضعیت آهن و روی در کودکان ابتدایی بود. روش بررسی: در این مطالعه که بصورت کار آزمایی بالینی دو سوکور انجام گرفت 81 دانش آموز پایه پنجم ابتدائی شهر خرم آباد به سه گروه تقسیم شدند. گروه اول مکمل آهن (20 میلی گرم آهن در روز)، گروه دوم مکمل روی (20 میلی گرم روی در روز) و گروه سوم مکمل آهن+ روی (20 میلی گرم آهن+20 میلی گرم روی) را به مدت 4 ماه دریافت نمودند. در آغاز و پایان مداخله شاخص های هموگلوبین با دستگاه سل کانتر، فریتین سرم با روش رادیوایمینواسی و با استفاده از دستگاه گاماکانتر و روی سرم با روش جذب اتمی اندازه گیری شد. از آزمون های ANOVA، t زوجی، کروسکال والیس و ویلکاکسون جهت تجزیه و تحلیل داده ها استفاده شد. یافته ها: نتایج بدست آمده نشان داد در گروه دریافت کننده مکمل روی به تنهایی، آهن همراه با روی و آهن به تنهایی میزان روی سرم نسبت به قبل از مداخله به ترتیب 1/2±5، 7/2±5/4 و 2/2±6/3 میکرومول در لیتر افزایش یافت (05/0

The effects of Fe4NiO4Zn nanoparticles on thyroid tissue and serum level of T3, T4 and TSH

زمینه و هدف: نانوذرات به دلیل اندازه کوچک و خواص فیزیکوشیمیایی منحصر به فرد کاربرد گسترده‌ای در صنایع داروسازی، ساختمان‌سازی، مواد غذایی و لوازم آرایش پیدا کرده‌اند. افزایش تولید و مصرف نانوذرات سنتزی سبب افزایش نگرانی در رابطه با اثرات جانبی منفی آن ‌ها بر سلامتی انسان شده است. هدف از مطالعه حاضر ارزیابی اثر نانوذره Fe4NiO4Zn بر میزان ترشح هورمون‌های تیروئیدی و TSH و همچنین بافت تیروئید بود. روش بررسی: در این مطالعه تجربی، 24 رت نر نژاد ویستار به صورت تصادفی به 3 گروه 8 تایی تقسیم شدند. گروه کنترل 5/0 میلی‌لیتر سرم فیزیولوژی و گروه دوم و سوم 5/0 میلی‌لیتر محلول نانوذره Fe4NiO4Zn را در غلظت‌هایppm ۱۰۰و 200 به مدت 7 روز متوالی دریافت کردند. غلظت هورمون‌های TSH و تیروئیدی در روزهای 2، 7 و 14 تعیین گردید. در روز 14 بافت تیروئید تحت بی‌هوشی عمیق خارج شده و مورد بررسی بافت شناسی قرار گرفت. یافته ها: تزریق صفاقی نانوذره Fe4NiO4Zn سبب کاهش معنی‌داری در غلظت TSH و افزایش معنی‌داری در غلظت هورمون T4 شد. نانوذره Fe4NiO4Zn تأثیر معنی‌داری بر سطح هورمون T3 نداشت. نانوذره Fe4NiO4Zn سبب تغییرات بافتی غده تیروئید شامل التهاب و بزرگ شدن فولیکول‌های شد. نتیجه گیری: نانوذره Fe4NiO4Zn قادر است با تأثیر بر محور هیپوتالاموس- هیپوفیز- آندوکراین و آسیب فولیکول‌های تیروئید ترشح هورمون‌های TSH و تیروکسین را تحت تأثیر قرار دهد

The Effect of Flavonoid Naringenin on Contractile Response of Thoracic Aorta Isolated from Diabetic Rats

Abstract: Background & Aims: Considering increasing incidence of cardiovascular disorders in diabetes mellitus and some evidence on antioxidant and antidiabetic potentials of naringenin, this study was conducted to evaluate the beneficial effects of 6-week administration of naringenin on contractile reactivity of isolated thoracic aorta in diabetic rats. Methods: Male Wistar rats were divided into control, naringenin-treated control, diabetic and glibenclamide-treated, and naringenin-treated diabetic groups. For induction of diabetes, streptozotcin (STZ) was administered (60 mg/Kg). Naringenin (10 mg/kg) was administered i.p. one week after diabetes induction in every other day intervals for 6 weeks. Serum glucose level was measured before naringenin administration and at 6th week. Finally, contractile reactivity of thoracic aortic rings to KCl and phenylephrine (PE) was cumulatively determined. Results: Serum glucose level at week 6 showed a significant decrease in naringenin-treated diabetic group compared to diabetics (P<0.01). In addition, naringenin-treated diabetic group showed a significantly lower contraction to PE (P<0.05) as compared to diabetic group and such significant reduction was also observed for KCl (P<0.05). Meanwhile, there was also a significant difference between control and naringenin-treated control groups regarding their contractile reactivity to PE (P<0.05). Conclusion: Subchronic administration of naringenin for 6 weeks could exert an anti-hyperglycemic effect and lowers contractile responsiveness of thoracic aorta rings to KCl and phenylephrine. Keywords: Naringenin, Diabetes mellitus, Aorta, Contractilit