Coherent optical CDMA with limited phase excursion

We examine the bit error rate (BER) of the conventional matched-filter detector for an optical code division multiple access (CDMA) system employing coherent homodyne detection. We assume a phase shift keying (PSK) modulation format where the phase is modulated by one of two methods: (1) an external phase modulator or (2) injection locking. Phase excursion is limited to ±0.42 π when using injection locking. We examine the bit error rate performance for both external modulation and modulation of the injection current and find only a moderate penalty (0.55 dB) associated with the limited phase excursion     

Ultrastructural study of the intracellular behavior of four mineral elements in the lactating mammary gland cells: study using conventional transmission electron microscopy

The effects of parenteral injection of aluminum, indium, gadolinium, or terbium in rats have been previously studied in several organs such as the liver, the kidneys, etc., but never in mammary glands. In this work, we have attempted to study the subcellular localization of these elements after their intraperitoneal administration. Their subsequent effects in the lactating mammary gland cells have also been studied. Our results using conventional transmission electron microscopy have shown that the lysosomes of the mammary glandular epithelial cells are the intracellular site of accumulation of the studied elements. Our results have also show intracellular deteriorations such as an expanded ergastoplasm and altered mitochondria after intraperitoneal injection of aluminum and indium.     

Effect of different milking intervals on the composition of cisternal and alveolar milk in dairy cows

Effects of six different milking intervals on the distribution of milk between cistern and alveoli were studied in a randomized, incomplete Latin Square experiment with four lactating Holstein cows. Cisternal and alveolar milk was measured by udder quarter at 4, 8, 12, 16, 20 and 24-h intervals with a 3-d interperiod of regular milking. Cisternal milk was evacuated using a cannula after injection of an oxytocin-receptor blocking agent, followed by an injection of oxytocin to remove the alveolar fraction. Milk samples from each fraction and quarter were collected for analysis. Cisternal and alveolar milk increased with milking interval and represented on average 30 and 70% of the milk stored in the udder, respectively. Fat content in alveolar milk remained constant during the first 16 h, increasing rapidly thereafter, reaching its maximum at 24 h (6.95%). Fat content in cisternal milk decreased with milking interval and reached its minimum at 24 h (0.96%). Total fat yield tended to increase for cisternal milk with longer milking intervals, but it increased markedly for alveolar milk, showing that fat globules did not pass freely from alveoli to cistern between milkings. Milk protein content was greater in rear quarters than in front quarters for both milk fractions. Milk protein content increased in the cisternal milk fraction and tended to increase in the alveolar milk fraction with longer milking intervals, but values did not differ between cisternal and alveolar fractions or between front and rear quarters. Total protein yield increased with milking interval in both fractions, indicating that casein micelles passed more freely than fat globules from the alveolar to the cisternal compartment. In conclusion, the short-term effects of milking intervals in milk composition were explained by the changes observed in alveolar and cisternal milk ratio.     

Use of ultrasonography to estimate cistern size and milk storage at different milking intervals in the udder of dairy cows

Four lactating Holstein cows (average milk yield: 20 +/- 3 l/d) were used to develop and validate a method for estimating the size of udder cisterns (Sinus lactiferi) using ultrasonography. A sectorial transducer probe of 5 MHz, placed in contact with the teat in a parallel cranial position, was used to obtain vertical scans of the udder in two perpendicular planes with the teat canal axis as reference. Udder scans for each udder quarter were taken randomly at intervals of 4, 8, 12, 16, 20 and 24 h after milking. Glandular parenchyma (echogenic) and lumen of the cisterns full of milk (anechogenic) were evident in the scans, the calculated area of the anechogenic portion being defined as cistern area. Cistern areas measured in perpendicular scans were highly correlated. Immediately after each measurement, cisternal milk was removed from each quarter using a teat cannula after i.v. injection of an oxytocin-receptor blocking agent. Alveolar milk from each quarter was then obtained by machine milking after i.m. injection of oxytocin. Cistern area and cisternal milk volume increased with length of milking interval showing a curvi-linear pattern with a plateau after 16 h. Correlations between cistern area and cisternal milk volume were positive and significant (P<0.001) at all intervals but showed the highest values with the smallest residual standard deviations at 8 h (r=0.88) and 12 h (r=0.84). Since 8 h has previously been identified as a suitable time at which to determine cisternal milk volume for the purposes of defining suitability for different milking strategies, we conclude that ultrasonography provides a satisfactory, non-invasive method for determination of milk storage characteristics in dairy cows.     

Deposit Generation During Camel and Cow Milk Heating: Microstructure and Chemical Composition

The aim of this study is to identify the chemical composition and the microstructure of the deposits obtained after heating camel and cow milks at 80 °C for 60 min using a laboratory-scale device. Like cow milk, camel milk was affected by heat treatment with the reduction of the non-casein nitrogen content reflecting the denaturation of camel whey proteins. The composition of the deposits generated during heating camel and cow milks at 80 °C for 60 min revealed that while camel deposit contained 57 % w/w protein, cow deposit showed a higher protein content of 69 % w/w. The mineral content was 35 % w/w for camel deposit which was higher than that of cow sample, which was 28 % w/w. SEM of both deposits showed a familiar structure of a protein deposit with large clumps composed of smaller aggregates. Camel deposit showed an amorphous structure due to its deficiency in β-lactoglobulin.     

Microscopy and microanalysis study of the indium (In) behavior in the intestinal mucosa, the liver, the kidney and the testicle

Several studies have demonstrated that In used in medicine has several impacts on organs like spleen and lungs after its systemic administration. In the present study, ultrastructural and microanalytical methods were used to investigate the impact of the presence of this element in the intestinal mucosa, the liver, the kidney and the testicle after its administration in two ways. After intraperitoneal administration, In was selectively concentrated in the lysosomes of hepatocytes, of tubular proximal convoluted cells and of Sertoli and Leydig cells. After intragastric administration, ultrastructural study showed that this element was concentrated in the lysosomes of duodenal enterocytes. Microanalytical methods showed that In was precipitated in those organelles in the form of insoluble phosphate salts. Similarly to other studies, it seemed that since In is a foreign element for the organism, it was precipitated in lysosomes, very probably due to the activity of an intralysosomal enzyme the acid phosphatase, to avoid its invasion to organism via the blood. This mechanism of precipitation of the mineral elements is of great interest in the process of defensive reaction of the organism against intoxication by foreign elements.     

Characterisation and phenolic profiles of two rare olive oils from southern Tunisia: Dhokar and Gemri‐Dhokar cultivars

BACKGROUND: The aim of this work was to study the chemical characteristics of two Tunisian cultivars, namely Dhokar and Gemri‐Dhokar, to analyse the fatty acids, sterols, triacylglycerols, triterpenic alcohols, and to determine the phenolic composition and oxidative stability. RESULTS: Among the rare varieties, Gemri‐Dhokar olive oil had the highest value of oleic acid (69.39%) whereas Dhokar oil was noteworthy for its lower content of phenolic compounds (94.56 mg kg^?1 gallic acid equivalents of oil) and presented the highest level of palmitic acid (19.37%). The main sterols found in all olive oil samples were β‐sitosterol and Δ5‐avenasterol, whereas cholesterol and 24‐methylenecholesterol were also found in all samples but in lower amounts. Two triterpenic dialcohols (erythrodiol and uvaol) were also detected and their content ranged from 1.45 to 2.30%, in Gemri‐Dhokar and Dhokar olive oil, respectively. Ten phenolic compounds were identified. In all samples, the main phenols found were oleuropein aglycon and pinoresinol. These phenolic compounds showed significant correlations with oxidative stability. CONCLUSION: The analytical parameters of two oils that were determined in this study were greatly influenced by genetic factors (cultivar). © 2012 Society of Chemical Industry     

Deterioration of a Tunisian coastal aquifer due to agricultural activities and possible approaches for better water management

The purpose of this study is to provide a better understanding of the impact of agricultural activities on groundwater quality in a semi‐arid coastal environment (Korba, Tunisia). Impacts have been assessed through groundwater samples that were analysed for a range of chemical and biological parameters. Results indicate that groundwater overexploitation for irrigation and fertiliser use have affected the quality of the groundwater not only by direct contamination but also seawater intrusion. The implementation of appropriate regulatory and economic instruments to foster sustainable practices in the agricultural sector have been analysed within the framework of the EC (European Community) FP6 (funding program 6) INECO (Institutional and Economic Instruments for Sustainable Water Management in the Mediterranean Region) Project. Through stakeholder involvement processes, the project analysed issues relating to the regulation and control of groundwater abstractions, the promotion of wastewater reuse, efficiency improvements in irrigation water use, as well as instruments to strengthen the socioeconomic and institutional environment towards better managing and conserving available groundwater resources.     

Coupling of local visualization and numerical approach for particle microfiltration optimization

The performance of the microfiltration process is controlled by the filter fouling due to the accumulation of solid matter forming a cake layer on the membrane surface. The objective of this work is to study the cake build up and growth at the particle level and to establish correlations with microfiltration performance measured at the process scale. A theoretical model coupling Navier–Stokes equation, convective/diffusion particle transport and deposit formation is developed to simulate a sequence of microfiltration in a confined geometry (Comsol Multyphysics^®). This model is used to make predictive simulations of cake growth during the filtration of diluted particles in the range of size of microorganism (5 μm). In the same time a specific filtration micro-system including an optical chamber and a microsieve (Aquamarijn^®) filtration membrane is designed in order to perform an experimental approach allowing in situ 3D-visualization of a deposit of model particles (polystyrene fluorescent microspheres) using Confocal laser scanning microscopy (CLSM). Based on image analysis, the cake building and properties (particle arrangement, thickness) are analyzed. These experimental data will be further used to improve the filtration model in order to obtain a predictive tool for process optimization.