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101.
102.
Bhargava A Jukes M Lambo J Kihamia CM Lorri W Nokes C Drake L Bundy D 《Food and nutrition bulletin》2003,24(4):332-342
To investigate the relationships between helminth infections and iron status among school-aged children, 1,115 Tanzanian children in grades 2 through 5 were randomly assigned to treatment or control groups. The children in the treatment group were screened for infection with Schistosoma haematobium and hookworm at baseline, 3 months, and 15 months; infected children were given albendazole against hookworm and praziquantel against schistosomiasis. The control group received a placebo and did not undergo parasitological screening until 15 months after the baseline. Hematological variables were compared between the treatment and control groups. The main results were, first, that the hemoglobin concentration significantly improved after treatment for hookworm (p < .001) by 9.3 g/L in children treated for hookworm only and by 8.8 g/L in children treated for hookworm and schistosomiasis. The ferritin concentration also improved in children treated for schistosomiasis (p = .001) or hookworm (p = .019). Second, a longitudinal analysis of the data from the children in the control group showed that hookworm and schistosomiasis loads were negatively associated with hemoglobin and ferritin concentrations. Moreover, ferritin concentrations increased as C-reactive protein levels increased. Overall, the results showed that anthelmintic treatment is a useful tool for reducing anemia in areas with high hookworm and schistosomiasis endemicity. The empirical relationship between ferritin and C-reactive protein indicated that simple procedures for adjusting cutoff points for the use of ferritin as an indicator of low iron stores were unlikely to be useful in this population. 相似文献
103.
A fluorescently labeled oligonucleotide probe (molecular beacon) was applied to detect Escherichia coli O157:H7 in artificially contaminated skim milk during polymerase chain reaction (PCR) amplification of extracted DNA. The probe was designed to hybridize with a region of the slt-II gene coding for the A subunit and to fluoresce when the hairpin-stem conformation was linearized upon hybridization to the target sequence. The molecular beacon was incorporated into PCR reactions containing DNA extracted from artificially contaminated skim milk. The degree of fluorescence was monitored in PCR reactions containing 10(3), 10(5), and 10(7) CFU of E. coli O157:H7 per ml and was found to correlate with the amount of template in each reaction. Fluorescence significantly increased above background levels by cycle 8, 14, or 14 in reactions containing DNA from the 10(7)-, 10(5)-, or 10(3)-CFU/ml template, respectively (P < 0.05). Molecular beacon PCR demonstrated positive results more rapidly than traditional agarose gel electrophoresis analysis of PCR products. Use of molecular beacons allows real-time monitoring of PCR reactions, and the closed-tube format allows simultaneous detection and confirmation of target amplicons without the need for agarose gel electrophoresis and/or Southern blotting. This is the first report of a stem-and-loop molecular beacon being applied for direct detection of a pathogen in food. 相似文献
104.
This paper describes how data from a variety of sources are merged to present new countrywide maps of the solar energy distribution over Ethiopia. The spatial coverage of stations with radiation data was found to be unsatisfactory for the purpose of a countrywide solar energy assessment exercise. Therefore, radiation had to be predicted from sunshine hours by employing empirical models. Using data from seven stations in Ethiopia, linear and quadratic correlation relationships between monthly mean daily solar radiation and sunshine hours per day have been developed. These regional models show a distinct improvement over previously employed countrywide models. To produce a national solar-energy distribution profile, a spatial extension of the radiation/sunshine relationships had to be carried out. To do this, the intercepts (a) and slopes (b) of each of the seven linear regression equations and another six from previous studies, completed in neighbouring Sudan, Kenya and Yemen, were used to interpolate the corresponding values to areas between them. Subsequent to these procedures, 142 stations providing only sunshine data were assigned their “appropriate” a and b values to estimate the amount of solar radiation received, which was then used to produce annual and monthly solar radiation distribution maps for Ethiopia. The results show that in all regions solar energy is an abundant resource. 相似文献
105.
Invasive, aquatic organisms have entered the North America Great Lakes from ships' ballast water, often originating from Europe. Current approaches for preventing the introduction of such organisms in ballast water include ballast water treatment (BWT) or ballast water exchange (BWE). This paper examines BWE, which is conducted in (1) waters >200 nautical miles (nm) from shore, or (2) waters >50?nm from shore and >200?m deep. We used historical records of ships transiting from Europe to the Great Lakes during one year (2014) to determine the duration (in days) that ships were within waters that met the criteria for BWE. Ship paths were classified based upon transitions between location-assigned “states” (e.g., from European waters across the North Atlantic Ocean to North America), and from these state transitions, four types of routes were identified. On average, ships sailing these routes had between 3.5 and 4.7 d to perform BWE in areas >200?nm from shore and 4.7 to 6.2 d when >50?nm from shore and >200-m deep water. Conducting BWE in daylight hours, if deemed necessary for safety, shortened the time window for BWE, especially in winter months, by approximately 50–70%. The state “machine” approach could, in the future, be used to identify ships from specific regions (e.g., ports within waterways at high risk of harboring potentially invasive species). Reshaping the definition of regional boundaries based upon time-of-year, water temperature, or other variables would further refine the ability to identify high-risk transits. 相似文献
106.
TJ Marten 《Canadian Metallurgical Quarterly》1999,103(1):224-236
Many patients seeking rejuvenation of their foreheads have high hairlines and are troubled by the prospect that surgery will worsen the deformity. Hairline elevation occurs in both coronal and endoscopic foreheadplasty techniques and is at least part of the reason that many surgeons do not always recommend these procedures when otherwise indicated. Although a pretrichial "hairline" incision prevents hairline retro-displacement, it results in forehead shortening only and not true hairline lowering. When a pretrichial incision is used in combination with a posterior scalp advancement flap, however, true hairline lowering is possible. Experience with this technique encompasses 27 procedures performed over a 5-year period. Patients ranged in age from 35 to 71 years. A significant improvement was demonstrable in all cases and corresponded with a high degree of patient satisfaction. No serious complications were seen. A high hairline must be recognized as the source of both a disproportionate and aged appearance. The ability to lower the hairline and place it in a more proportionate, youthful relationship with the rest of the face adds a new dimension to foreheadplasty equal to or greater in importance to an overall improved appearance as other maneuvers typically performed during the procedure. For many patients, the benefits of hairline lowering far outweigh the trade-off of a more anteriorly situated, and possibly more visible, scar. 相似文献
107.
108.
The paper examines and compares structural concepts considered for use as habitats for lunar and Martian outposts. An evaluation methodology that allows numeric rating of concepts was previously developed and is upgraded herein. The methodology defines a number of important characteristics on which concepts are to be judged. In addition, weighting factors are assigned for the various characteristics considered in the evaluation system. These factors are presented as variables that depend on mission goals and timing aspects. An example evaluation is made for a specific scenario utilizing the developed methodology. The overall purpose of this work is not to provide an absolute rating, but rather to identify strengths and weaknesses of concepts. This approach should be invaluable in the development and selection of structural concepts for extraterrestrial habitats. 相似文献
109.
The recently published 1994 National Earthquake Hazards Reduction Program (NEHRP) provisions include new and substantially improved provisions for the seismic design of nonstructural components, including architectural, mechanical, and electrical components. The provisions are a significant departure from the 1991 NEHRP provisions and other seismic provisions, such as those offered by the 1994 Uniform Building Code (UBC). The design-force provisions are rationally derived and consider actual in-structure acceleration data recorded in recent significant California earthquakes. Also considered in the design-force equations are the dynamic properties of the components, the location of the component within the supporting structure, the safety and operational importance of the component, and the component's anchorage ductility and energy-absorption capability. The resulting force requirements of the new recommendations are compared with the 1991 NEHRP provisions and the 1994 UBC requirements. In addition, explicit design displacement provisions are introduced and discussed. 相似文献
110.