Epidemiological profile, mineral metabolic pattern and crystallographic analysis of urolithiasis in Kuwait

This study was conducted to determine the epidemiological profile of urolithiasis in Kuwaiti patients and the associated metabolic abnormalities favouring stone formation in this patient population. Between 1986 and 1994, a total of 421 Kuwaiti patients were studied in Al-Amiri renal stone laboratory. The mineral composition of stones was determined using a combination of stereoscopic microscopy and infrared spectrophotometry. Mineral metabolic screen (MMS) was available in 306 (72.7%) of those patients. The average annual incidence of new stone formation in Kuwaiti patients was 23.9 per 100,000 population. The incidence was only 6.9 per 100,000 population in those from pediatric age group, 33.4 in adults and 73.6 in the elderly. The frequency of new stone formation was higher among males as compared to females at different age groups. Calcium oxalate (CaO) constituted 72.1% of renal stones encountered in adults as compared to only 52.1% and 40.7% in elderly and pediatric age groups. Eighty four patients had recurrent and/or high stone load. Detailed family history was available in 57 of those 84 patients and was suggestive of strong family aggregation of stone disease in 30 (53%) patients. The proportion of urate stones was 15.4% of all stones formed and constituted a major cause of renal stones in children (24.1%), adults (14.4%) and elderly (12.5%). Cystine stones were found in 10 patients (2.4%). Hyperuricemia was detected in 1/3 of patients from pediatric age group. In adults, 89 (38.4%) of 232 patients had abnormal MMS, of which hyperuricosuria with or without hyperuricemia accounted for 79.8% of those abnormalities. In elderly patients, metabolic disorders were detected in 7 (17.5%) of the 40 patients. In the latter group, all except one, had hyperuricosuria with or without hyperuricemia. Cystinuria, distal renal tubular acidosis (d-RTA) and hyperparathyroidism constituted 6.6% of metabolic abnormalities in the patients studied. Primary abnormalities of upper and lower urinary tract was detected in 6% of adult patients as compared to 47% in children and 30% in the elderly. In conclusion; the incidence rate of new stone former in Kuwait is significantly lower from that reported in Europe and USA. This latter finding and the high familial aggregation of urolithiasis in our area constitute a cogent argument against the role of hot climate in the pathogensis of urolithiasis and are in favour of genetic predisposition. Isolated hyperuricosuria was detected in 17% of idiopathic CaO stone formers. The latter finding is of practical importance since red-meat is a common food item in our area and restriction of purine-intake may help to decrease the frequency of urate and CaO stone formation in predisposed patients.

Laser fluorescence quantification of remineralisation in situ of incipient enamel lesions: influence of fluoride supplements

The aims of this study were to test the laser fluorescence method for quantification of remineralisation in situ of enamel with incipient lesions and to evaluate the enhancement of remineralisation by fluoride (F) supplements when a F dentifrice was used on a regular basis by healthy young subjects. Enamel samples were cut from extracted premolar teeth with the natural surface kept intact, and subjected to a pH-cycling system to produce subsurface demineralisation in vitro. The enamel blocks were then inserted into composite holders bonded to the buccal surfaces of both upper first molars of 12 panelists. Each panelist participated in 3 separate experiments in a randomised order; each lasted for 5 weeks with washout intervals of 2 weeks between experiments; experiment 1: F dentifrice (0.145% F as NaF) only; experiment 2: F dentrifice + F lozenges (0.25 mg F x 6/day); experiment 3: F dentifrice + F chewing-gum (0.25 mg F x 6/day). Fluorescence radiance was measured before, during, and after in vitro demineralisation, and once a week during the in situ experimental periods. The enamel samples were then sectioned and analysed with transverse microradiography (TMR). Anova and Pearson correlation coefficient were used for the statistical analysis. At the end of the 5-week in situ periods, fluorescence radiance had been regained to a level of 80-100% of the value before in vitro demineralisation, indicating remineralisation of the enamel samples. There were no differences in the fluorescence radiance gain between the 3 different F exposures. However, there was a statistically significant time trend (p < 0.001), and a highly significant linear dependence (p < 0.001) between the final measurements obtained with the laser fluorescence method (LAF) and the data obtained from TMR, r = 0.76. It was concluded that: (1) with the sensitive LAF method it was possible to register the small changes in the enamel week by week during in situ remineralisation: (2) when F dentrifice was used regularly, F supplements such as F lozenges or F chewing-gum did not significantly enhance the in situ remineralisation of incipient enamel lesions in healthy, young adults with normal salivary flow.

Effect of a two-solution fluoride mouth rinse on deposition of loosely bound fluoride on sound root tissue and remineralization of root lesions in vitro

A constant-composition fluoride (F) titration method was used to measure the amount of leachable F deposited on root surfaces in vitro by a 1-min rinse with a 12 mmol/l sodium fluoride (228 micrograms/g F) solution or a two-solution rinse that contained 2 mmol/l sodium fluorosilicate (228 micrograms/g total F ) and 10 mmol/l calcium chloride. The mean +/- standard deviations (n = 3) F uptake from the two rinse treatments were 0.70 +/- 0.24 micrograms/cm2 and 3.25 +/- 0.74 micrograms/cm2, respectively. In a separate experiment, the effects of sodium fluoride and the two-solution rinses on remineralization of root lesions were evaluated in an in vitro pH cycling model. The results showed that the average decrease in mineral loss (delta Z) in the two-solution rinse group (60%) was significantly greater than that obtained in the NaF rinse (41%) or the control (9%) group.

Relationships between the bone pathologies, ash and mineral content of long bones in 35-day-old broiler chickens

Histological examinations and estimations of the contents of ash, phosphorus and calcium were used to investigate the femora and tibiotarsi from lame and normal 35-day-old broilers from Holland, Northern Ireland and Scotland. The prevalence of different pathologies varied with the source of the broilers and there were correlations between histological and bone ash values. The most common condition causing lameness was bacterial infection within the physis and cartilaginous epiphysis (bacterial chondronecrosis) of the proximal tibiotarsus, and there was a possible link between rickets attributable to a relative phosphorus deficiency and this condition. There were wide variations between birds in the cortical bone quality as assessed histologically and by estimates of the bone ash content and phosphorus to calcium ratios. Theses variations may be related to different probabilities of bone fracture.

Nutritional survey of pregnant women in Hungary

A nutritional survey of a Hungarian group of pregnant women was carried out. One hundred and twenty nine women aged 25.9 years, entered the study, but only 70 completed all the protocol. Average body weight gain was 12.4 kg and the mean birth weight of the newborns was 3,386 g. Mean energy and nutrient intakes of pregnant women showed similar patterns as in Hungarian non-pregnant women of the same age. The mean energy intake was high (11 MJ), being 10% higher than for non-pregnant women. The mean protein and lipid intakes were also high, 91.9 g and 108.4 g, respectively, exceeding by 7% and 6% the intakes of the non-pregnant women. Dietary intakes of saturated fatty acids (SFAs) and monounsaturated fatty acids (MUFAs) were close to 12% of energy, and the intake of polyunsaturated fatty acids (PUFAs) was 7.6% of total energy. Palmitic acid (16:0), oleic acid (18:1 n-9) and linoleic acid (18:2 n-6) made the greatest contribution to the total peak area of SFAs, MUFAs, and PUFAs, respectively. The ratio of P/S (polyunsaturated/saturated fatty acids) was appropriate: 0.65; however, the ratio of linoleic acid (18:2 n-6), to linolenic acid (18:3 n-3) was high: 16. The cholesterol intake was somewhat lower in pregnant than in non-pregnant women. Complex carbohydrate intake was low (245 g) but it was still by 75% higher than in non-pregnant women. The excess sodium intake (6.3 g) was very similar to that of non-pregnant women. Mean values for retinol, tocopherol, ascorbic acid, cobalamin and copper intakes were higher than the Hungarian Recommended Dietary Allowances (RDA). Thiamine, riboflavin, pyridoxine, niacin, calcium, iron and zinc intakes were insufficient. Data showed an imbalance in the energy and nutrient intakes of Hungarian pregnant women, and this could be harmful for both the mother and pregnancy outcome.

[Evaluation of modern child nutrition in boarding schools in Taimyr]

The given reference includes an information about a nourishment, an average daily nutrient and energetic content of foodstuffs in the menu of students in boarding schools on Tajmir. It is determined that there is a disbalance of the main components and the fatty acid, mineral, vitamin contents in the menu of the children of all the ages. The nourishment of the children living in the condition of the Far North has been demonstrated to need correcting.

Digestibility of phosphorus in protein-rich ingredients for pig diets

Two experiments were run to determine the digestibility of phosphorus in different vegetable and animal proteins for the pig diet. Each experiment comprised two 4 x 4 Latin squares run concurrently. Pigs initially weighing 30 kg were kept in metabolism crates and fed twice daily at about 2.5-fold metabolisable energy requirement for maintenance. A semi-purified basal diet low in phosphorus and without intrinsic phytase activity was fed either alone or after blending into mixtures with one of the ingredients to be tested. Mixtures were calculated to contain not more than 2 g digestible P/kg DM and between 5.0 and 6.0 g Ca/kg DM. Faeces and urine were quantitatively collected for 8 days after 7 days of adaptation. Phosphorus digestibility for ingredients under test was calculated assuming the digestibility of phosphorus from the basal diets to be constant in all diets. P digestibilities in solvent extracted soybean meal from dehulled seed, rapeseed and solvent extracted rapeseed meal were 37, 42 and 24%, respectively. Supplementation of a microbial phytase (750 U/kg diet) improved digestibility coefficients significantly to 76, 66 and 73%, respectively. Digestibility of phosphorus in 3 different batches of fish meal ranged from 85 to 90%, without significant differences between batches. In 3 different types of carcass meal, digestibility coefficients were 80, 82 and 83% without significant differences between types, and digestibility of phosphorus from bone meal was 80%.

Physicochemical characteristics of five date fruit cultivars grown in the United Arab Emirates

The physical measurements and chemical analyses of date fruits of five cultivars grown in the United Arab Emirates were measured in this study. Due to differences in seed weight, the flesh accounted for 83-92% of the total fruit. At the tamr stage, the absence of sucrose and the presence of higher concentrations of reducing sugars, especially fructose and glucose, characterized these cultivars as the soft type. On maturation from the kimri to the tamr stage, the sugar content had increased, but other constituents like moisture, crude protein, crude fat, ash, crude fiber, tannins, and pectin had decreased.

Paleodietary analysis on the prehistoric population of El Hierro (Canary Islands)

In order to deepen our knowledge of the dietary habits of the prehispanic inhabitants of El Hierro, we have determined bone strontium (Sr), manganese (Mn), magnesium (Mg), copper (Cu), zinc (Zn), and calcium (Ca) in 52 human tibiae (23 belonging to male and 20 to female individuals) buried in a single burial cave; in 21 modern individuals who served as controls; and in 11 bones of herbivores found at archeological sites of the Canary Islands. Results suggest that females consumed a more vegetarian diet, although site-corrected Sr/Ca ratio of both males and females speaks for a mixed-diet consumption.

The primitive matrix components of the unique carbonaceous chondrite Acfer 094: a TEM study

The mineralogical and chemical characteristics of the fine-grained matrix (< or = 3 micrometers) of the unique primitive carbonaceous chondrite Acfer 094 have been investigated in detail by scanning electron microscopy (SEM) and analytical transmission electron microscopy (ATEM). Generally, the fine-grained matrix represents a highly unequilibrated assemblage of an amorphous material, small forsteritic olivines (200-300 nm), low Ca-pyroxenes (300-400 nm), and Fe,Ni-sulfides (100-300 nm). The matrix is basically unaffected by secondary processes. Only minor amounts of serpentine and ferrihydrite, as products of hydrous alteration, are present. Texturally, the amorphous material acts as a groundmass to olivines, pyroxenes, and sulfides, mostly exhibiting rounded or elongated morphologies. Only very few clastic mineral grains have been found. The texture and chemical composition of the amorphous material are consistent with an origin by disequilibrium condensation in either the cooling solar nebula or a circumstellar environment. As such, the amorphous material may be considered as a possible precursor of matrix materials in other types of chondrites. The non-clastic matrix olivines (Fo98-99) and pyroxenes (En97-100) are suggested to have formed either by condensation in the solar nebula under highly oxidizing conditions or by recrystallization from the amorphous material. The formation of these grains by fragmentation of chondrule components is unlikely due to chemical and microstructural reasons. Rapid cooling caused the observed intergrowths of clino/orthoenstatite in the Mg-rich matrix pyroxenes. Although some similarities exist comparing the fine-grained matrix of Acfer 094 with the matrices of the unequilibrated CO3 chondrite ALHA77307 and the unique type 3 chondrite Kakangari, Acfer 094 remains unique. Since it contains the highest measured concentrations of circumstellar SiC and the second highest of diamond (highest is Orgueil), it seems reasonable to suggested that at least parts of the amorphous material in the fine-grained matrix may be of circumstellar origin.

Recycling of inorganic nutrients for hydroponic crop production following incineration of inedible biomass

The goal of resource recovery in a regenerative life support system is maintenance of product quality to sure support of reliable and predictable levels of life support function performance by the crop plant component. Further, these systems must be maintained over extended periods of time, requiring maintenance of nutrient solutions to avoid toxicity and deficiencies. The focus of this study was to determine the suitability of the ash product following incineration of inedible biomass as a source of inorganic nutrients for hydroponic crop production. Inedible wheat biomass was incinerated and ash quality characterized. The incinerator ash was dissolved in adequate nitric acid to establish a consistent nitrogen concentration is all nutrient solution treatments. Four experimental nutrient treatments were included: control, ash only, ash supplemented to match the control treatment, and ash only quality formulated with reagent grade chemicals. When nutrient solutions were formulated using only ash following incineration of inedible biomass, a balance in solution is established representing elemental retention following incineration and nutrient proportions present in the original biomass. The resulting solution is not identical to the control. This imbalance resulted in a suppression of crop growth. When the ash is supplemented with reagent grade chemicals to establish the same balance as in the control--growth is identical to the control. The ash appears to carry no phytotoxic materials. Growth in solution formulated with reagent grade chemicals but matching the quality of the ash only treatment resulted in similar growth to that of the ash only treatment. The ash product resulting from incineration of inedible biomass appears to be a suitable form for recycle of inorganic nutrients to crop production.

Geochemistry of approximately 1.9 Ga sedimentary rocks from northeastern Labrador, Canada

Fifty-eight rock chips from fifteen samples of sedimentary rocks from the Ramah Group (approximately 1.9 Ga) in northeastern Labrador, Canada, were analyzed for major and minor elements, including C and S, to elucidate weathering processes on the Earth's surface about 1.9 Ga ago. The samples come from the Rowsell Harbour, Reddick Bight, and Nullataktok Formations. Two rock series, graywackes-gray shales of the Rowsell Harbour, Reddick Bight and Nullataktok Formations, and black shales of the Nullataktok Formation, are distinguishable on the basis of lithology, mineralogy, and major and trace element chemistry. The black shales show lower concentrations than the graywackes-gray shales in TiO2 (0.3-0.7 wt% vs. 0.7-1.8 wt%), Al2O3 (9.5-20.1 wt% vs. 13.0-25.0 wt%), and sigma Fe (<1 wt% vs. 3.8-13.9 wt% as FeO). Contents of Zr, Th, U, Nb, Ce, Y, Rb, Y, Co, and Ni are also lower in the black shales. The source rocks for the Ramah Group sediments were probably Archean gneisses with compositions similar to those in Labrador and western Greenland. The major element chemistry of source rocks for the Ramah Group sedimentary rocks was estimated from the Al2O3/TiO2 ratios of the sedimentary rocks and the relationship between the major element contents (e.g., SiO2 wt%) and Al2O3/TiO2 ratios of the Archean gneisses. This approach is justified, because the Al/Ti ratios of shales generally retain their source rock values; however, the Zr/Al, Zr/Ti, and Cr/Ni ratios fractionate during the transport of sediments. The measured SiO2 contents of shales in the Ramah Group are generally higher than the estimated SiO2 contents of source rocks by approximately 5 wt%. This correction may also have to be applied when estimating average crustal compositions from shales. Two provenances were recognized for the Ramah Group sediments. Provenance I was comprised mostly of rocks of bimodal compositions, one with SiO2 contents approximately 45 wt% and the other approximately 65 wt%, and was the source for most sedimentary rocks of the Ramah Group, except for black shales of the Nullataktok Formation. The black shales were apparently derived from Provenance II that was comprised mostly of felsic rocks with SiO2 contents approximately 65 wt%. Comparing the compositions of the Ramah Group sedimentary rocks and their source rocks, we have recognized that several major elements, especially Ca and Mg, were lost almost entirely from the source rocks during weathering and sedimentation. Sodium and potassium were also leached almost entirely during the weathering of the source rocks. However, significant amounts of Na were added to the black shales and K to all the rock types during diagenesis and/or regional metamorphism. The intensity of weathering of source rocks for the Ramah Group sediments was much higher than that of typical Phanerozoic sediments, possibly because of a higher PCO2 in the Proterozoic atmosphere. Compared to the source rock values, the Fe3+/Ti ratios of many of the graywackes and gray shales of the Ramah Group are higher, the Fe2+/Ti ratios are lower, and the sigma Fe/Ti ratios are the same. Such characteristics of the Fe geochemistry indicate that these sedimentary rocks are comprised of soils formed by weathering of source rocks under an oxygen-rich atmosphere. The atmosphere about 1.9 Ga was, therefore, oxygen rich. Typical black shales of Phanerozoic age exhibit positive correlations between the organic C contents and the concentrations of S, U, and Mo, because these elements are enriched in oxygenated seawater and are removed from seawater by organic matter in sediments. However, such correlations are not found in the Ramah Group sediments. Black shales of the Ramah Group contain 1.7-2.8 wt% organic C, but are extremely depleted in sigma Fe (<1 wt% as FeO), S (<0.3 wt%), U (approximately l ppm), Mo (<5 ppm), Ni (<2 ppm), and Co (approximately 0 ppm). This lack of correlation, however, does not imply that the approximately 1.9 Ga atmosphere-ocean system was anoxic. Depletion of these elements from the Ramah Group sediments may have occurred during diagenesis.

Controlled environments alter nutrient content of soybeans

Information about compositional changes in plants grown in controlled environments is essential for developing a safe, nutritious diet for a Controlled Ecomological Life-Support System (CELSS). Information now is available for some CELSS candidate crops, but detailed information has been lacking for soybeans. To determine the effect of environment on macronutrient and mineral composition of soybeans, plants were grown both in the field and in a controlled environment where the hydroponic nutrient solution, photosynthetic flux (PPF), and CO2 level were manipulated to achieve rapid growth rates. Plants were harvested at seed maturity, separated into discrete parts, and oven dried prior to chemical analysis. Plant material was analyzed for proximate composition (moisture, protein, lipid, ash, and carbohydrate), total nitrogen (N), nonprotein N (NPN), nitrate, minerals, amino acid composition, and total dietary fiber. The effect of environment on composition varied by cultivar and plant part. Chamber-grown plants generally exhibited the following characteristics compared with field-grown plants: 1) increased total N and protein N for all plant parts, 2) increased nitrate in leaves and stems but not in seeds, 3) increased lipids in seeds, and 4) decreased Ca:P ratio for stems, pods, and leaves. These trends are consistent with data for other CELSS crops. Total N, protein N, and amino acid contents for 350 ppm CO2 and 1000 ppm CO2 were similar for seeds, but protein N and amino acid contents for leaves were higher at 350 ppm CO2 than at 1000 ppm CO2. Total dietary fiber content of soybean leaves was higher with 350 ppm CO2 than with 1000 ppm CO2. Such data will help in selecting of crop species, cultivars, and growing conditions to ensure safe, nutritious diets for CELSS.

Date bars fortified with almonds, sesame seeds, oat flakes and skim milk powder

Fortified date bars were prepared from some of the commonly grown date cultivars in the United Arab Emirates. The average ash, fat and protein contents in the control date bar sample were 1.78, 6.09 and 7.83%, respectively. The ash and protein contents increased, but the fat content decreased slightly with the inclusion of skim milk powder in the remaining date bar formulations. All the date bar samples were found to be free from Enterobacteriaceae and coliforms. Date fruit, which usually supplies only calories, can thus be turned into a product having significant amounts of other valuable nutrients.

Proximate composition and functional properties of fullfat and defatted beniseed (Sesamum indicum L.) flour

The proximate composition and functional properties of fullfat and defatted beniseed (Sesamum indicum L.) flour were evaluated. Functional properties studied were foam capacity and stability, water and oil absorption, bulk density, emulsion capacity and nitrogen solubility. Defatting increased the crude protein, ash, crude fiber, carbohydrate and mineral contents. Defatted flour showed comparatively better foam capacity and stability, water absorption and emulsion capacities but diminished bulk density and oil absorption capacity. Nitrogen solubility was pH dependent with a minimum at pH 4 and maximum at pH 8. Maximum nitrogen solubility (95%) was recorded for defatted flour while that for the fullfat flour was 60%. The proximate composition and functional properties of the samples suggest that beniseed flour would have useful application in fabricated foods.

Jack bean (Canavalia ensiformis): nutrition related aspects and needed nutrition research

The nutritional characteristics and food potentials of jack bean (Canavalia ensiformis) have been reviewed. The bean is a good sources of protein, 23% to 34%, and carbohydrate 55%. It is also a good source of Ca, Zn, P, Mg, Cu and Ni. Jack bean protein is adequate in most essential amino acids with the exception of methionine and cystine which may be nutritionally limiting. Antinutritional and toxic factors including trypsin inhibitors, hemagglutinins, cyanogen glucosides, oligosaccharides and others are present in jack bean. Properly processed jack bean could be used to prepare some of the popular dishes made from cowpea, peanut, pigeon pea and soybean. Industrial products such as protein concentrates and isolates, starch, flakes, grits and flours can be produced from the bean. Further research is needed to identify varieties with high protein and nutritional quality. Development of new highly nutritious food products based on whole or processed jack bean should increase production and expand use.

An overview: recycling nutrients from crop residues for space applications

Without some form of regenerative life support system, long duration space habitation or travel will be limited severely by the prohibitive costs of resupplying air, water, and food from Earth. Components under consideration for inclusion in a regenerative life support system are based on either physicochemical or biological processes. Physicochemical systems would use filtration and elemental phase changes to convert waste materials into usable products, while biological systems would use higher plants and bioreactors to supply crew needs. Neither a purely biological nor strictly a physicochemical approach can supply all crew needs, thus, the best each approach can offer will be combined into a hybrid regenerative life support system. Researchers at Kennedy Space Center (KSC) Advanced Life Support Breadboard Project have taken the lead on bioregenerative aspects of space life support. The major focus has been on utilization of higher plants for production of food, oxygen, and clean water. However, a key to any regenerative life support system is recycling and recovery of resources (wastes). In keeping with the emphasis at KSC on bioregenerative systems and with the focus on plants, this paper focuses on research with biologically-based options for resource recovery from inedible crop residues.

Effect of tibial dyschondroplasia on carcase part weights and bone characteristics

1. The effect in broilers of tibial dyschondroplasia (TD) on carcase part weights and bone characteristics was investigated by studying the progeny of 10 sires and 40 dams. The correlations between TD and bone variables were also estimated. 2. The incidence of TD was 59% at 42 d of age. There were no significant differences in slaughter weight of birds with and without TD. However, in females, breast weight was heavier in affected birds. Neck plus back weight of birds with TD was significantly heavier than in birds without TD. 3. Breast blister frequency of birds was independent of the presence of TD. 4. Birds with TD had longer bones than birds without TD. However, TD had no effect on tibiotarsus weight, width, ratio of tibiotarsal to body weight and ash. A negative correlation was observed between TD score and bone ash percentage.

[Meteoritics and mineralogy on possible ancient Martian life]

Possible relic biogenic activity in martian meteorite ALH84001 was proposed by McKay et al. (Science, 273, 924-930, 1996). This ancient meteorite of 4.5 billion years old contains abundant carbonates as secondary minerals precipitated from a fluid on the martian surface. They showed the following lines of evidence for the ancient life; (1) unique mineral compositions and biominerals, (2) polycyclic aromatic hydrocarbons (PAHs) in association with the carbonates, and (3) unique structures and morphologies typical of nanobacteria or microfossils. This review is divided into two parts; one is on the martian meteorites in general and ALH84001, which has many features unlike other martian meteorites, and the other is on mineralogical (biomineralogical) and geochemical features of the carbonates and microfossil-like structures. There is little doubt that ALH84001 is from Mars as well as eleven other SNC meteorites. However, the mineralogical and biomineralogical evidence for martian bacteria given by McKay et al. (1996) is controversial, and could be formed by non-biogenic processes. Thus, further study of ALH84001 and other martian meteorites is required. We also need to consider the future Mars mission especially sample return mission.

X-ray digital imaging petrography of lunar mare soils: modal analyses of minerals and glasses

It is essential that accurate modal (i.e., volume) percentages of the various mineral and glass phases in lunar soils be used for addressing and resolving the effects of space weathering upon reflectance spectra, as well as for their calibration such data are also required for evaluating the resource potential of lunar minerals for use at a lunar base. However, these data are largely lacking. Particle-counting information for lunar soils, originally obtained to study formational processes, does not provide these necessary data, including the percentages of minerals locked in multi-phase lithic fragments and fused-soil particles, such as agglutinates. We have developed a technique for modal analyses, sensu stricto, of lunar soils, using digital imaging of X-ray maps obtained with an energy-dispersive spectrometer mounted on an electron microprobe. A suite of nine soils (90 to 150 micrometers size fraction) from the Apollo 11, 12, 15, and 17 mare sites was used for this study. This is the first collection of such modal data on soils from all Apollo mare sites. The abundances of free-mineral fragments in the mare soils are greater for immature and submature soils than for mature soils, largely because of the formation of agglutinitic glass as maturity progresses. In considerations of resource utilization at a lunar base, the best lunar soils to use for mineral beneficiation (i.e., most free-mineral fragments) have maturities near the immature/submature boundary (Is/FeO approximately or = 30), not the mature soils with their complications due to extensive agglutination. The particle data obtained from the nine mare soils confirm the generalizations for lunar soils predicted by L.A. Taylor and D.S. McKay (1992, Lunar Planet Sci. Conf. 23rd, pp. 1411-1412 [Abstract]).

Effects of feeding a return chewing gum/packaging material mixture on performance and carcass characteristics of feedlot cattle

Seventy-two Simmental-cross growing steers (219 +/- 2.4 kg initial BW) were used in a randomized complete block design to evaluate the effects of feeding a return chewing gum/packaging material mixture (G/P) on feedlot performance, carcass characteristics, sensory attributes of meat, and mineral content of beef liver and muscle. Animals were allotted by weight to 12 pens (six/pen). Each pen was assigned one of three dietary treatments: 1) 0% G/P (control), 2) 20% G/P, or 3) 30% G/P (% G/P on a DM basis). Steers were fed their respective diets for an 84-d growing phase and a 112-d finishing phase. The G/P replaced corn silage and corn in the growing and finishing phases, respectively. Eighteen steers (six/treatment) were randomly selected for slaughter at the end of the finishing phase, and carcass measurements, sensory attributes of meat, and mineral content of liver and longissimus muscle were measured. During the growing phase, steers fed G/P-containing diets had improved (P < .01) daily DMI, ADG, and gain:feed ratios (G:F) compared with controls. However, due to compensatory gain and the fact that G/P replaced corn in the finishing phase, control steers had increased (P < .01) ADG and improved (P < .05) G:F vs steers fed G/P-containing diets. Over the entire study (growing and finishing phases) steers fed diets containing G/P and the control had similar performance. Amount of G/P in the diet had no effect (P > .05) on carcass characteristics. Steaks from steers fed 20% G/P had improved (P < .01) juiciness compared with steaks from steers fed 30% G/P; no other sensory attributes were affected. Aluminum, zinc, and barium content of longissimus muscle and liver were within the normal expected ranges for all treatments. These data indicate that G/P can safely replace at least 30% of growing and finishing diets without impairing feedlot performance or carcass merit.

In vitro measurement of enamel demineralization in the assessment of fluoride-leaching orthodontic bonding agents

The aim of this study was to measure in vitro demineralization around orthodontic brackets, bonded with five different bonding agents. Two conventional bonding agents, two fluoride-leaching agents, and a glass ionomer were tested. A sixth group utilized a fluoride varnish after bonding. The amount of dissolved enamel mineral was determined from increases in the phosphorus concentration in the demineralizing solution and measurements were made over a 4 week period. The results confirmed that when fluoride is present in the form of a fluoride-leaching bonding agent or a fluoride varnish, resistance to demineralization is enhanced. Analysis of variance showed that Ketac-cem, Concise with Duraphat, and Pulpdent O.B.A. performed statistically significantly better than Concise, Bond-fast, and Rely-a-bond, in resisting enamel demineralization.

Enamel mineral composition of normal and cystic fibrosis transgenic mice

The ability of ameloblasts and the enamel organ to control the influx of ions into the developing enamel is of considerable interest. The development of transgenic mice lacking a cAMP-regulated chloride channel, the cystic fibrosis transmembrane conductance regulator (CFTR), provides a model that may prove valuable for the study of ion regulation in developing teeth. The purpose of this investigation was to characterize the mineral content of normal and CF mice. Five homozygous and five heterozygous adult mice having the CFTR knockout transgene were evaluated. The mice were killed with CO2 and their mandibular incisors removed, embedded in methacrylate, and sectioned, and enamel particles from the incisal region were then dissected for analysis. Each particle was analyzed for its calcium, phosphorus, and magnesium content. The normal mice had a mean mineral content of 80.5%, in contrast to the CF mice, that had markedly hypomineralized enamel (mean = 51.5%). The calcium/phosphorus ratios were similar for both groups of mice and were compatible with the enamel consisting primarily of hydroxyapatite mineral. The enamel magnesium content was significantly elevated in the CF mice (mean = 3560 ppm) compared with the normal mice (mean = 2280 ppm). Normal mouse enamel was highly mineralized, while the CF mouse enamel mineral content was significantly reduced and had an elevated level of magnesium. The altered mineral content of CF mouse enamel indicates that CFTR could play an important role in ion regulation and consequently mineralization of mouse enamel.

Comparison of body composition and bone mineral measurements from two DXA instruments in young men

The purpose of this study was to compare body-composition and whole-body, lumbar spine (LS), femoral neck (FN), trochanter, and Ward's triangle (WT) bone mineral measurements by using the Hologic QDR 1000W (DXAH) and the Lunar DPX-L (DXAL) dual-energy X-ray absorptiometry instruments. In addition, the ability of conversion equations to predict DXAH data from DXAL data were tested. Thirteen healthy young adult males (aged 22.2 +/- 3.6 y, 177.4 +/- 5.3 cm in height, and 72.7 +/- 9.6 kg in weight) were scanned on the same day by using DXAH and DXAL. Whereas measured body mass was not different (P > 0.05) between machines, whole-body fat mass [DXAH-DXAL (DXAdiff) = 1152 +/- 1395 g], percentage fat (DXAdiff = 1.5 +/- 1.7% of body mass), bone mineral density (BMD; DXAdiff = 0.016 +/- 0.023 g/cm2), and bone mineral content (BMC; DXAdiff = 316 +/- 50 g) were lower and whole-body fat-free soft tissue (FFST; DXAdiff = 1781 +/- 1859 g) was higher with DXAH than with DXAL. Lower fat mass (DXAdiff = 2145 +/- 855 g) and BMC (DXAdiff = 216 +/- 36 g) and higher FFST (DXAdiff = 1966 +/- 943 g) in the trunk were primarily responsible for the whole-body differences. Lower BMD and BMC values were found for LS (DXAdiff = 0.145 +/- 0.038 g/cm2 and 3 +/- 2 g, respectively), trochanter (DXAdiff = 0.100 +/- 0.044 g/cm2 and 1.7 +/- 1.0 g), and WT (DXAdiff = 0.195 +/- 0.061 g/cm2 and 1.93 +/- 0.51 g) with DXAH compared with DXAL. DXAH BMD of FN was also lower (DXAdiff = 0.141 +/- 0.032 g/cm2) than with DXAL. Only DXAH whole-body BMC and LS BMD were accurately predicted from DXAL with conversion equations. Predicted DXAH FN BMD was significantly lower than the actual DXAH value (P < or = 0.05), whereas the discrepancy between DXAH and DXAL actually increased for whole-body percentage fat and BMD (DXAdiff = 6.6 +/- 1.3% body mass and 0.020 +/- 0.025 g/cm2). In conclusion, lower whole-body fat mass, percentage fat, and BMC, and higher whole-body FFST with DXAH were due primarily to measurement differences in the trunk. Whereas conversion equations accurately predicted DXAH whole-body BMC and LS BMD from DXAL measurements in young adult males, they did not accurately predict DXAH, percentage fat, and BMD of the whole body and FN BMD.