Calibration and evaluation of Skylab altimetry for geodetic determination of the geoid

There are no author-identified significant results in this report

Calibration and evaluation of Skylab altimetry for geodetic determination of the geoid

There are no author-identified significant results in this report

Interaction of marine geodesy, satellite technology and ocean physics

The possible applications of satellite technology in marine geodesy and geodetic related ocean physics were investigated. Four major problems were identified in the areas of geodesy and ocean physics: (1) geodetic positioning and control establishment; (2) sea surface topography and geoid determination; (3) geodetic applications to ocean physics; and (4) ground truth establishment. It was found that satellite technology can play a major role in their solution. For solution of the first problem, the use of satellite geodetic techniques, such as Doppler and C-band radar ranging, is demonstrated to fix the three-dimensional coordinates of marine geodetic control if multi-satellite passes are used. The second problem is shown to require the use of satellite altimetry, along with accurate knowledge of ocean-dynamics parameters such as sea state, ocean tides, and mean sea level. The use of both conventional and advanced satellite techniques appeared to be necessary to solve the third and fourth problems

Geodetic analysis of Skylab altimetry preliminary data - SL/2 EREP pass 9

The author has identified the following significant results. The analysis was based on a time series intrinsic relationship between the satellite ephemeris, altimeter measured ranges, and the corresponding a priori values of subsatellite geoidal heights. Using sequential least squares processing with parameter weighting, the objective was to recover (1) the absolute geoidal heights of the subsatellite points, and (2) the associated altimeter calibration constant(s). Preliminary results from Skylab altimetry are given, using various combinations of orbit ephemeris and altimeter ranges as computed differently by NASA/JSC and NASA/Wallops. The influences of orbit accuracy, weighting functions, and a priori ground truth are described, based on the various combination solutions. It is shown that to deduce geoidal height by merely subtracting the height of the satellite from the altimeter range is inadmissible. The results of such direct subtraction can be very misleading if the orbit used is computed from data that included altimeter data used as height constraints. In view of the current state of knowledge, the use of geodetic ground truth samples as control benchmarks appears indispensable for the recovery of absolute geoidal heights with correct scale

Calibration and evaluation of Skylab altimetry for geodetic determination of the geoid

There are no author-identified significant results in this report

Metal Contamination Of Foods and Drinks Consumed in Ota, Nigeria

Food consumed in Ota, Nigeria are prone to contamination with environmental metal pollutants. The concentrations of lead (Pb), cadmium (Cd), nickel (Ni), mercury (Hg), copper (Cu), manganese (Mn) and zinc (Zn) were determined in some commonly consumed foods and drinks using Atomic Absorption Spectrophotometry (AAS). Samples selected included fried yam, fried bean cake (akara), roasted plantain (bole), roasted meat (suya), roasted fish, cassava flour (fufu), yam flour (amala), garri (eba), beans and herbal drink (agbo jedi jedi). Lead was present only in roasted meat (0.02±0.02 mg kg-1), garri (0.04±0.06 mg kg-1) and roasted plantain (0.004±0.01 mg kg-1). Copper and cadmium ranged from 0.02±0.19-3.55±0.20 and 0.02±0.01-0.59±0.17 mg kg-1, respectively. The mean concentration of zinc and nickel ranged from 0.09±0.10-1.19±1.52 and 0.04±0.01-6.38±7.61 mg kg-1, respectively. The mean concentration of manganese ranged from 0.06±0.05-0.25±0.19 mg kg-1. Manganese was absent in agbo jedi jedi (ethanolic). Some of the foods including roasted plantain (bole), roasted meat (suya), roasted fish, cassava flour (fufu), yam flour (amala) and beans were contaminated with nickel above FAO/WHO tolerable limits. Agbo jedi jedi was found to be contaminated with cadmium, nickel and copper above safety levels. Mercury was present only in roasted plantain at a level of 0.91±1.28 mg kg-1 which was beyond tolerable limits. This study indicates that consumers of the foods and drinks with high levels of metal contamination may be exposed to health risks associated with their presenc

Atypical presentation of colon adenocarcinoma: a case report

<p>Abstract</p> <p>Introduction</p> <p>Adenocarcinoma of the colon is the most common histopathological type of colorectal cancer. In Western Europe and the United States, it is the third most common type and accounts for 98% of cancers of the large intestine. In Uganda, as elsewhere in Africa, the majority of patients are elderly (at least 60 years old). However, more recently, it has been observed that younger patients (less than 40 years of age) are presenting with the disease. There is also an increase in its incidence and most patients present late, possibly because of the lack of a comprehensive national screening and preventive health-care program. We describe the clinicopathological features of colorectal carcinoma in the case of a young man in Kampala, Uganda.</p> <p>Case presentation</p> <p>A 27-year-old man from Kampala, Uganda, presented with gross abdominal distension, progressive loss of weight, and fever. He was initially screened for tuberculosis, hepatitis, and lymphoma, and human immunodeficiency virus/acquired immunodeficiency syndrome infection. After a battery of tests, a diagnosis of colorectal carcinoma was finally established with hematoxylin and eosin staining of a cell block made from the sediment of a liter of cytospun ascitic fluid, which showed atypical glands floating in abundant extracellular mucin, suggestive of adenocarcinoma. Ancillary tests with alcian blue/periodic acid Schiff and mucicarmine staining revealed that it was a mucinous adenocarcinoma. Immunohistochemistry showed strong positivity with CDX2, confirming that the origin of the tumor was the colon.</p> <p>Conclusions</p> <p>Colorectal carcinoma has been noted to occur with increasing frequency in young adults in Africa. Most patients have mucinous adenocarcinoma, present late, and have rapid disease progression and poor outcome. Therefore, colorectal malignancy should no longer be excluded from consideration only on the basis of a patient's age. A high index of suspicion is important in the diagnosis of colorectal malignancy in young African patients.</p

The impact of tubal ectopic pregnancy in Papua New Guinea - a retrospective case review

BACKGROUND: Ectopic pregnancy (EP) is an important cause of morbidity and mortality amongst women of reproductive age. Tubal EP is well described in industrialised countries, but less is known about its impact in low-resource countries, in particular in the South Pacific Region. METHODS: We undertook a retrospective review of women with tubal EP treated at a provincial referral hospital in coastal Papua New Guinea over a period of 56 months. Demographic and clinical variables were obtained from patients’ medical records and analysed. The institutional rate of tubal EP was calculated, and diagnosis and management reviewed. Potential risk factors for tubal EP were identified, and delays contributing to increased morbidity described. RESULTS: A total of 73 women had tubal EP. The institutional rate of tubal EP over the study period was 6.3 per 1,000 deliveries. There were no maternal deaths due to EP. The mean age of women was 31.5+/−5.7 years, 85% were parous, 67% were rural dwellers and 62% had a history of sub-fertility. The most commonly used diagnostic aid was culdocentesis. One third of women had clinical evidence of shock on arrival. All women with tubal EP were managed by open salpingectomy. Tubal rupture was confirmed for 48% of patients and was more common amongst rural dwellers. Forty-three percent of women had macroscopic evidence of pelvic infection. Two-thirds of patients received blood transfusions, and post-operative recovery lasted six days on average. Late presentation, lack of clinical suspicion, and delays with receiving appropriate treatments were observed. CONCLUSIONS: Tubal EP is a common gynaecological emergency in a referral hospital in coastal PNG, and causes significant morbidity, in particular amongst women residing in rural areas. Sexually transmitted infections are likely to represent the most important risk factor for tubal EP in PNG. Interventions to reduce the morbidity due to tubal EP include the prevention, detection and treatment of sexually transmitted infections, identification and reduction of barriers to prompt presentation, increasing health workers’ awareness of ectopic pregnancy, providing pregnancy test kits to rural health centres, and strengthening hospital blood transfusion services, including facilities for autotransfusion