Some aspects of respiratory function in anaesthetised dogs

Some respiratory and circulatory parameters were established for dogs during routine clinical anaesthesia. The possible effects on these parameters of positioning the animals in left lateral, right lateral and dorsal postures were also studied.One hundred clinical dogs and eight experimental dogs were included in this study. The clinical dogs were categorised into two equal groups; group A, for which complete physiological and biochemical data were available and group B, for which the biochemical data were not available. All dogs were anaesthetised by a minimal dose of thiopentone sodium followed by nitrous oxide and halothane throughout the anaesthetic period.PHYSIOLOGICAL PARAMETERS: The respiratory and circulatory parameters which were measured were minute volume, respiratory rate and pulse rate. A review of the literature of the workers noted a decrease in during anaesthesia associated with respiratory rate and tidal volume. showed that a majority minute volume of dogs a decrease in both In man, increases in tidal volume and respiratory rate were frequently observed but the net effect on minute volume was variable, depending on the degree of change in the two components.In this study, a significant positive corelation was found between tidal volume and body weight, and between minute volume and body weight, whilst a significant inverse corelation was established between respiratory rate and body weight.Changes in tidal volume during anaesthesia were not significant. However, respiratory rate and in consequence minute volume showed a significant increase.Minute volume values recorded in dorsal recumbency were found to be significantly higher than the values obtained in lateral postures. In dogs maintained in left lateral and right lateral postures respiratory rate values were comparable, but were significantly lower than the values recorded in dorsal posture. Thus the differences in the minute volume values were determined predominately by the differences observed in the respiratory rates.Pulse rate was found to fall during the interval from ten minutes following induction of anaesthesia until the end of the anaesthetic period. No significant corelation was evident between the pulse rate and body weight or between the pulse rate values obtained in left lateral, right lateral and dorsal postures.BIOCHEMICAL PARAMETERS: The biochemical parameters examined were pH, PaCO2 and Pa02' A review of the literature showed that all authors found an increase in the arterial blood carbon dioxide tension with a moderate to a severe respiratory acidosis in both man and animals.In the present study arterial carbon dioxide tension rose significantly above the preanaesthetic level, and this was associated with a considerable fall in arterial pH. The changes in the standard bicarbonate levels were not significant. The mean PaCO2 value recorded after ix sixty minutes of anaesthesia in dorsal posture was signifi- cantly higher than the mean values obtained in either of the left or right lateral postures. The fall in pH was proportionate to the retention of carbon dioxide. The mean pH values were significantly lower in dogs maintained in dorsal posture than in either of the lateral postures. The standard bicarbonate values recorded in dogs maintained in the three postures were not significantly different.Arterial oxygen tension rose significantly above the control levels. The mean Pa°2 values obtained in the left and right lateral postures were comparable and they were higher than those recorded in dorsal posture.Haemoglobin concentration decreased significantly during anaesthesia, but the extent of this fall did not differ in different postures.As a result of this investigation it is concluded that the exchange of respiratory gases is impaired in spontaneously breathing dogs under anaesthesia and the concomitant progressively developing acidosis is attributed mainly to this cause. The efficiency of ventilation is further reduced in the dorsal posture compared with the lateral.It is recommended that the respiratory blood gases should be intermittently monitored during the anaesthesia of clinical patients, particularly those having hypoxia or acid base abnormalities as part of their clinical syndrome.Adequate oxygenation can be maintained by administering oxygen rich mixtures with the anaesthetic gases but the elimination of carbon dioxide from those patients having high PaCO2 levels will require the animals to be artificially ventilated.It is suggested that the component of respiration most requiring supplementing is the tidal volume, an increase of rate by itself having been shown in the clinical cases which were breathing spontaneously to be inefficient as a compensatory measure

Elemental Contents in Hair of Children from Two Regions in Dar Es Salaam

The work presented in this paper is part of the study which aims at determining the levels of elements in hair of children in Tanzania as a bioindicator of their nutrition and health. In this paper, the levels of trace elements in hair from children living in Dar es Salaam have been analysed. The analysis was carried out by long and short irradiation INAA at the reactor centre of the Institute of Nuclear Physics, Rez Czech Republic. 22 samples were collected from children living at Kiwalani about 12 km from Dar es Salaam city and 16 samples from children living at Mlimani, the main campus of University of Dar es Salaam. A total of 34 elements were found in the hair of the children. There were no big differences between the concentration levels of the essential elements in hair samples collected from the children which might indicate the same food consumption habits

Assessment of heavy metal and radioactivity levels in spinach (Spinacia oleracea) grown at Bahi wetlands in Dodoma region

This study reports on the levels of heavy metals and radionuclides in Spinach (Spinacia oleracea) grown in Bahi wetlands in Dodoma Region. The farm soil in Bahi wetland has been reported to contain elevated concentrations of 238U, 232Th and 40K due to the existence of shallow uranium deposit in the area. In this study, spinach (Spinacia oleracea) grown in three zones of Bahi district were analyzed for heavy metals and radioactivity associated with the uranium deposit in the area. The concentrations of elements were determined by Energy Dispersive X-ray Analysis (EDXRF) of Tanzania Atomic Energy Commission, Arusha. The activities of the radionuclides were calculated from their concentration in µg/g. The concentrations of Pb and Cd in all samples were found to be higher than the maximum tolerable limits recommended by Codex 2015. The results show that, the mean activities of 232Th (10.8 Bq/kg) and 40K(686.9 Bq/kg)in the samples are lower than the maximum tolerable limits (1000 Bq/kg) recommended by WHO/FAO, yet higher than their activities in samples of spinach collect from a control area. Hence, regular monitoring of heavy metals and radioactivity level in farm soils and agricultural products is recommendedKey words: Heavy metals, radioactivity, spinach, Bahi Wetland, EDXR

Indoor radon concentration levels and annual effective doses for residence of houses near uranium deposit in Bahi district, Dodoma, Tanzania

The objective of this study was to determine the levels of indoor radon concentration in houses in Bahi District situated in the neighbourhood of uranium deposit. The study aimed also to assess the annual effective dose due to indoor radon exposure to individuals residing in the houses as a step to control the radon exposure in Tanzania. Two villages were involved in this study; Bahi Makulu, which is within the proximity of Uranium deposit and Bahi Sokoni, which is about 7 km from the deposit. The Indoor radon concentration levels were detected using Alpha Guard radon monitor and the obtained mean concentration levels are presented and compared with the mean concentrations levels published in literature. The results revealed that 78% of the houses involved in this study have concentration levels of indoor radon above the reference level of 100 Bq/m3 set by WHO 2009. The levels are higher in traditional houses which are mostly built with poor ventilation than the modern houses with good ventilation. Out of the two villages involved in this study, Bahi Makulu which is closer to the uranium deposit has significantly higher (p<0.01) concentrations of indoor radon than Bahi Sokoni. The calculated annual effective doses for the population in both villages are higher than the dose reference level of 1 mSv/y. Key words: Indoor Radon, Bahi District, Uranium deposit, Annual effective dos

Assessment of radioactivity levels in coal and coal ash in Kiwira coal mine using gamma-ray spectrometry

This study aimed to assess the radioactivity levels and associated dose rates from the naturally occurring radionuclides 226Ra, 232Th and 40K in coal and coal ashes at Kiwira coal mine. The radioactivity of 40 representative coal, fly ash samples were measured using gamma spectroscopy of the Tanzania Atomic Energy Commission (TAEC) in Arusha, Tanzania. The activity concentrations of 226Ra, 232Th and 40K in coal and coal ashes from Kiwira were higher by several orders of magnitude than their worldwide average values. The calculated radium equivalent activity, the air absorbed dose rate, external hazard index and the average annual effective dose rate in fly ashes were 1335 ± 60 Bq kg-1,  610 ± 29 nGy h-1, 4 ± 0.4, 738 ± 52 µSv y-1 which were higher than the international recommended values of 370 Bq kg-1, 57 nGy h-1, and 70 µSv y-1 for fly-ashes respectively. The results provide information for the radiation protection when the coal and its by-products in the vicinity of Kiwira coal field is used. The data can be used by the authorities to design an appropriate method for handling wastes and implement intervention measures to protect the miners, the public as well as the environment.Keywords: Coal, fly ash, soil, radioactivity, gamma-ray spectrometr

Determination of radioactivity in maize and mung beans grown in the neighborhood of Minjingu phosphate mine, Tanzania

Two staple foods (maize and mung beans) which were cultivated in Minjingu village, where there is phosphate deposit in Tanzania, were collected directly from the farms. The activity concentrations of 226Ra, 228Th and 40K were determined in the maize and mung beans samples using γ ray spectrometry employing HPGe detector of relative efficiency of 51.0 %. The mean radioactivity level in the food samples were found to be 21.01 ± 0.8 Bq/kg (mung beans), 25.6 ± 0.7 Bq/kg (maize) for 226Ra, 62.6 ± 1.1 Bq/kg (mung beans), 72.9 ± 1.0 Bq/kg (maize) for 228Th and 542.9 ± 8.6 Bq/kg (mung beans), 434.6 ± 18.7 Bq/kg (maize) for 40K. The radioactivity content of the maize and mung beans from Minjingu village were higher than that of similar food samples collected from Bukombe district in Geita Region in Tanzania. The total annual effective dose for consumption of 226Ra and 228Th by adults was calculated to be 2.003 ± 0.044 mSv/year, which is higher than the annual dose limit of 1 mSv/year recommended by the ICRP for the general public. Hence a conclusion could be made that food crops cultivated at Minjingu village might expose the population to high radiation dose which might be detrimental to their health.Keywords: Radioactivity, annual effective dose, Minjingu Phosphate mine, High Background Radiation Are

The renal glomerulus of the dog; its normal structure and its reaction to immunological injury

Familiarity with normal glomerular anatomy is an essential prerequisite to understanding the pathogenesis of glomerulonephritis and interpretation of glomerular abnormalities detected by light microscopy, immunofluorescence and electron microscopy, Glomerulonephritis is now recognised to be an important canine nephropathy and it is clear that it is the formation of immune complex deposits in the glomerular filter that is responsible for virtually all types of glomerulonephritis seen in man and animals. In Chapter 3 of the present work, an attempt was made to highlight the most important gaps in our understanding of the normal dog glomerulus with particular reference to a number of important parameters such as methods of fixation and embedding, thickness of section and variation in glomerular size between inner and outer cortical levels. Chapter 4 provided a detailed study of sequential autolytic changes in the dog glomerulus. Under controlled experimental conditions, glomerular changes in dogs killed from two minutes up to five days after death were recorded using combined light, transmission and scanning electron microscopy. This study showed that, while autolytic changes particularly when observed with the electron microscope, occurred very rapidly after death, nevertheless there was a significant amount of cytological preservation as late as three days. In Chapters 5 and 6, a series of experiments were carried out to study the response of the dog glomerulus to various forms of immunological injury. Chapter 5 provided an in depth study of experimentally- induced nephrotoxic (anti-glomerular basement membrane) nephritis in dogs with particular reference to the sequential changes occurring in the glomeruli from 30 minutes after receiving anti-GBM rabbit serum up to the termination of the experiment at 80 days. Using combined histologic, immunofluorescence and ultrastructural methods the present study revealed the remarkable ability of the canine glomerulus to recover from a severe immunologically-mediated attack. During the last three decades, the increasing utilization of immunological techniques in the study of renal disease has clearly established that glomerulonephritis, the most important renal disease of man and his closest animal associates the dog and cat, are immunological in origin. In Chapter 6, a series of serum sickness experiments were undertaken, for the first time using the dog as an experimental animal, to induce a number of different forms of immune complex glomerulonephritis, namely "one-shot" serum sickness and accelerated serum sickness. Furthermore, as membranous nephropathy is the most common form of spontaneous immune complex glomerulonephritis in the dog, a lesion which does not occur with the above two experimental methods, an attempt was made to make use of charged antigens (cationized bovine serum albumin) in a chronic serum sickness experiment. Overall, the immunofluorescence, histological and ultrastructural features encountered in this experiment resembled closely those described in spontaneous cases of canine membranous nephropathy

The Performance Enhancement Study of FIR Filters Based on Adjustable Window Function

The aims of this study are enhancement the performance of low pass FIR (Finite Impulse Response) Filters by using adjustable window design method, and reduce the amplitude of side lobes and Gibbs phenomenon problems in these filters,also study the effect of different orders of low pass FIR filters (20th ,70th, 200th ) on its performance when the parameter β in fixed value in the time domain and frequency domain, and investigate the effect of different values of parameter β=0.5,3,6,9 on its performance when the filter order in fixed value in the time domain and frequency domain.These filters are used in the ECG signal applications to remove high frequency noise. The simulation of design these filters is implementing by using FDA tool (filter design and analysis tool) and wintool (window tool) from matlab (R2010a) program. The study results have been obtained the lowest value of relative side lobe attenuation= -66.2dB with thin main lobe width = 0.016602 when the filter order and the parameter β are equal to 200th, 9 respectively, we find that Kaiser window function is the optimum window to reduce side lobe amplitude and to reduce the Gibbs phenomenon with control of the main lobe width as compared with other windows such as Hamming, Bartlett, Blackman and Rectangular, and gives much better stop band attenuation than the Parks-McClellan algorithm

Assessment of heavy metal concentration in water around the proposed Mkuju River Uranium Project in Tanzania

Effective verification for compliance with water quality standards in uranium mining in Tanzania requires data sensitive to monitor heavy metal concentration in water around the Mkuju River Uranium Project before mining commences. The area susceptible for pollution by the project was estimated using AERMOD dispersion model and found to cover about 1300 km2. Thirty one surface and groundwater samples were collected and analysed for heavy metals and physicochemical properties using ICP-MS and standards techniques, respectively. The physicochemical properties for water samples analysed ranges from 5.7 to 7.8 for pH, 2.8 to 80.2 mg/L for TDS and 15 to 534.5 mS/cm for EC. These values show that the water in the vicinity of the Mkuju River Uranium Project is normal. The ranges of concentration of heavy metals (μgL-1) determined in water ranges were: Al(2 to 9049), Cr(0.2 to 19.96), Mn (0.1 to 1452),Fe(2 to 53890),Co(0.02 to 27.63), Ni(0.2 to 9.7), Cu(2 to 17), Zn(2 to 62.94), As(0.4 to 19.17), Cd(0.02 to 0.14), Pb (0.02 to 78.68), Th (0.002 to 1.73),U(0.002 to 29.76). These values are below the tolerance levels of concentrations set by different International organisations. Therefore heavy metal toxicity in the study area is marginal. The parameters that could serve as baseline data because of their enhanced sensitivity to pollution were (i) concentration of chromium, cobalt, nickel, copper, zinc, arsenic, cadmium and lead in water (ii) pH, TDS and EC for water, (iii) TDS ratio for surface to ground water values and (iv) correlation coefficients between the heavy metals. However, since TDS values are season dependent, this indicator can serve as baseline data when measured during the dry season as was the case in the study.Keywords: Baseline, Heavy Metal Pollution, Mkuju River Project, Uranium Mining, Water Pollutio

Improve a secure blind watermarking technique for digital video

In recent years, digital watermark video has become increasingly popular in a range of industries, but because it is widely available on the Internet, it is simple to make unlawful copies and tamper with digital video. Watermarking digital video has become more popular as a method of detecting changes and preventing illegal duplication. This paper presents a video copyright protection system that is secure, blind, and robust. Two approaches that are resistant to diverse attacks are proposed in this research. The initial step is to encrypt a hybrid watermark (Message, Image) using two different encryption techniques (RSA and AES).The second is a steganography technique based on LSB-based robust watermarking, which embeds an encrypted secret bit Message and Image in key frames of an MP4 video file by utilizing the mean of the grayscale images that differ and take the most significant differences between the two images. The intensity of the histogram will become more consistent across all pixels as the encryption quality improves. For keyframe watermarking in the spatial domain, the proposed methods can maintain the watermarked information while achieving high imperceptibility and a Peak Single to Noise Ratio [PSNR] equivalent to more than 50 db, where quality measures (MSE, PSNR, and correlation coefficient) that calculate the levels of distortion caused by embedding a watermark in digital video produce good results