Fatty acids composition of microalgae Chlorella vulgaris can be modulated by varying carbon dioxide concentration in outdoor culture

Varying culture methods of Chlorella vulgaris (CV) has been associated with different nutrient composition. The aim of this study was to investigate the fatty acid contents and other nutrients of CV subjected to various culturing conditions. We found that CV cultured under 24 h light and 10% CO2 showed the best growth rates and contained higher lipid, protein and moisture contents compared to other culture conditions. Interestingly, the content of fatty acids of CV was dependent on the amount of CO2. Fatty acid analysis of CV by gas chromatography-mass spectrometry (GC-MS) showed the presence of cis-10-pentadecanoic acid (C15:1), palmitic acid (C16:0), palmitoleic acid (C16:1), heptadecanoic acid (C17:0), stearic acid (C18:0), oleic acid (C18:1n9c), linoleic acid (C18:2n6c), linolenic acids (C18:3n3) and arachidic acid (C20:0). Remarkably, polyunsaturated fatty acids (linoleic and linolenic acids) are found in abundance compared to other fatty acids in CV. The concentrations of palmitic, oleic, linoleic and linolenic acids increased when the amount of carbon dioxide was raised from 1 to 10% under both culture conditions (12 and 24 h light). This study shows the possibility of modifying lipid contents in freshwater microalgae by varying the amount of carbon dioxide and light.Key words: Chlorella vulgaris, microalgae, fatty acids, vitamins, minerals, carbon dioxide

Diagnostic accuracy of ultrasonography compared to unenhanced CT for stone and obstruction in patients with renal failure

BACKGROUND: To determine accuracy of ultrasound (US) kidney, ureter and bladder (KUB) compared to un-enhanced helical CT (UHCT) in patients with renal failure in the diagnosis of stone and obstruction. METHODS: This is a case controlled study conducted in the period from June 2000 to July 2003 at a university hospital. All patients had both US and UHCT scan. Patients with serum creatinine ≥ 1.8 mg/dl were included in the study. Only direct visualization of stone was considered as confirmatory. In both the studies, UHCT and US, presence of stone and obstruction were noted. The relevant biochemicals, radiological and clinical records of all the patients were analyzed. Data was analyzed using commercially available software. RESULTS: During the period of study 864 patients had UHCT for evaluation of the urinary tract in patients presenting with flank pain. Out of these 34 patients had both UHCT and US done within a span of one day and had serum creatinine of ≥1.8 mg/dl. Mean age was 48 ±15.8 years and 59% of patients were males. UHCT identified renal stones in 21 (62%), whereas 17 of these were identified on US, with a sensitivity of 81%. Of the four patients with renal stones missed on US, three were identified on plain x-ray; the mean size of stones missed was 6.3 mm. Of the 22 (65%) patients with ureteric stone on UHCT, US could only identify 10; a further 7 were identified on x-ray KUB, giving a sensitivity of 45% (US alone) and 77% (US with x-ray KUB). CONCLUSIONS: US is sensitive and specific for renal stones, 81% and 100% and for hydronephrosis, 93% and 100%, respectively. Its sensitivity to pick ureteric stone (46%) and to identify hydroureter (50%) is low. Addition of x-ray KUB abdomen increases the sensitivity for ureteric stones to 77%

Effect of climate on maximum oxygen consumption among elite football players / Norasrudin Sulaiman

The maximum oxygen consumption (VO2max) level has been indicated to influence the technical and tactical performance during the football game. There are many variables that are considered as the factors that influenced the VO2max level of the player. One of the major factors that often been studied is the climate. The purpose of current study was to determine effect of climate on maximum oxygen consumption among elite football players. Fifteen (n=15) elite male football (mean±SD aged, 21.3± 3.4 years old; height, 167.7± 10.6 cm and; weight, 59.4± 3.1 kg) players who represent university in Malaysian Premier Football League are willing to participate in this study. All subjects underwent the bleep test during morning (T: 29.7°C, H: 80%) and evening (T: 32.6°C, H: 63%) to measure their VO2max level in both conditions. Subjects also need to go for blood sampling immediately after the Bleep Test. The result from test tests showed that there are no significant differences of the VO2max level and the lactate production between the two climates conditions. Thus, it can be conclude that the tested climate has no significant effects on VO2max among elite football players

Variation over time of the Perez calibration algorithm for ground-based spectrometer

A spectrometer is likely to perform as expected over a period of time if calibrated with suitable method. This paper aims to study the variation of the Perez calibration algorithm over time for a spectrometer. The study was carried out for six months from July to August 2012 and January–April 2013. The measurements were recorded for every minute interval from 8.30 a.m. to 4.30 p.m. in three locations in Kota Kinabalu, Sabah, Malaysia. Monthly calibration constants for eight wavelengths were determined for the Perez model using improved Langley method. When only wavelengths which are close to 500 nm (460, 500, 540, 580, and 620 nm) were engaged, the variations over time of the Perez calibration constants were consistent over time (F = 1:381, p = 0:273). This is similar to the previous ?nding on the Du Mortier algorithm

Insight into potential mechanisms of hypobaric hypoxia–induced learning and memory deficit – Lessons from rat studies

Impairment of memory is one of the most frequently reported symptoms during sudden hypoxia exposure in human. Cortical atrophy has been linked to the impaired memory function and is suggested to occur with chronic high-altitude exposure. However, the precise molecular mechanism(s) of hypoxia-induced memory impairment remains an enigma. In this work, we review hypoxia-induced learning and memory deficit in human and rat studies. Based on data from rat studies using different protocols of continuous hypoxia, we try to elicit potential mechanisms of hypobaric hypoxia–induced memory deficit

Natural coagulates for wastewater treatment; a review for application and mechanism

The increase of water demand and wastewater generation is among the global concerns in the world. The less effective management of water sources leads to serious consequences, the direct disposal of untreated wastewater is associated with the environmental pollution, elimination of aquatic life and the spread of deadly epidemics. The flocculation process is one of the most important stages in water and wastewater treatment plants, wherein this phase the plankton, colloidal particles, and pollutants are precipitated and removed. Two major types of coagulants are used in the flocculation process included the chemical and natural coagulants. Many studies have been performed to optimize the flocculation process while most of these studies have confirmed the hazardous effects of chemical coagulants utilization on the ecosystem. This chapter reviews a summary of the coagulation/flocculation processes using natural coagulants as well as reviews one of the most effective natural methods of water and wastewater treatment