Sequence of food presentation influences intake of foods containing tannins and terpenes

Interactions among nutrients and secondary compounds in plants can influence the kinds and amounts of different forages herbivores ingest, but little is known about how the sequence of plant ingestion may influence these interactions. The physiological pathways and rates of nutrient and secondary compound metabolism in the body influence food intake by herbivores. On this basis, we predicted the sequence in which foods that vary in nutrients and secondary compounds are ingested would influence food intake and preference. In a 2 × 2 factorial experiment, we evaluated the relationship between the sequence of presenting two foods, one with terpenes and the other with tannins, and the time when lambs ate a nutritious food (alfalfa–barley), either before or after eating foods with tannins and terpenes. When alfalfa–barley was fed prior to the terpenes, intake of the terpene-containing food was lower than when alfalfa–barley was fed after terpenes (P < 0.05). The sequence when alfalfa–barley was fed did not influence intake of the tannin-containing food (P > 0.10). Lambs ate more total foods with terpenes + tannins when fed tannins → terpenes → alfalfa/barley than when fed alfalfa/barley → tannins → terpenes (P < 0.10). During preference tests, when lambs were offered all three foods simultaneously, lambs previously conditioned with the sequence tannins → terpenes → alfalfa–barley preferred alfalfa–barley > terpenes > tannins (P < 0.05), whereas lambs in other treatments preferred alfalfa–barley > tannins > terpenes (P < 0.05). During preference tests when lambs were fed only foods with secondary compounds, lambs previously conditioned with the sequence tannins → terpenes → alfalfa–barley showed equal preference for foods with tannins and terpenes, whereas lambs in other treatments preferred food with tannins > terpenes (P < 0.05–0.10). All of these results are consistent with the hypothesis that the sequence in which foods are consumed affects both food intake and preference. Understanding the importance of sequencing when herbivores consume foods that vary in nutrients and secondary compounds may help managers create new grazing strategies that include sequential foraging patterns to optimize food intake and more evenly use all plant species in a community, a practice used by herders in France.     

Applicability of food composition tables as a tool to estimate mineral and trace element intake of pre-school children in Japan: A validation study

Because dietary intakes of some minerals (including trace elements), especially iron (Fe), are insufficient for the needs of the general Japanese population, accurate estimation of mineral intake is important. This capability is especially necessary to preserve the health of Japanese children. Therefore, the current version of food composition tables (FCT) in Japan was evaluated for validity as tools to estimate dietary intake of minerals for children. For this purpose, 24 h food duplicate samples were collected from 292 pre-school children in Miyagi prefecture, Japan. From the weights of items and food codes, intakes of nine minerals were estimated taking advantage of the FCT. In parallel, amounts of minerals in each duplicate samples were instrumentally measured by ICP-AES for Ca, Cu, Fe, Mg, Mn, P and Zn, and by flame AAS for K and Na, both after wet-ashing. The distributions of the mineral amounts were essentially normal. The comparison of the FCT-based estimates (E) and instrumental measures (M) showed that the E/M ratio was close to 1 for Ca, K, Mn, P and Zn, suggesting that E may be a surrogate of M for Ca, K, Mn, P and Zn on a group basis. The ratio being larger than 1.2 for Cu, Fe, Mg and Na indicates that a risk of over-estimation exists when E is relied upon in place of M. On an individual basis, significant differences were detected for all 9 minerals suggesting that the use of E as a surrogate for M should be practiced with care for the estimation of mineral intake.     

Nodularin in feathers and liver of eiders (Somateria mollissima) caught from the western Gulf of Finland in June–September 2005

Nodularins are cyanobacterial hepatotoxins, which may cause intoxication at very low exposure levels. The nodularin-producing cyanobacterium Nodularia spumigena usually forms massive blooms in much of the Baltic Sea during the summer season. Breast feathers and liver samples from common eider (Somateria mollissima) were analysed for nodularins by liquid chromatography–mass spectrometry (LC–MS) and enzyme-linked immunosorbent assay (ELISA). Fifteen eiders from the western Gulf of Finland were caught by hunters between June and September 2005. Blue mussels (Mytilus edulis), a dietary component of the birds, were also obtained by diving near the same marine area and time as the collection of the ducks. Eider breast feathers contained 6–52 μg nodularin-R (Nod-R)/kg dry weight (dw) by ELISA, and 8–43 μg Nod-R/kg dw by LC–MS. No Nodularia filaments were adhered to feather samples according to light microscopy assessment. Liver samples from the same individuals contained Nod-R between 3 and 48 μg/kg dw by LC–MS. Mussel samples from the area contained Nod-R at concentrations of 12–80 μg/kg dw by LC–MS. Analysis of bird feathers offers a facile and non-invasive means of assessing the exposure of birds to nodularins.     

2-Amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) level in human hair as biomarkers for dietary grilled/stir-fried meat and fish intake

Several case-control studies have reported possible associations between heterocyclic amine (HCA) intake and the risk of cancer. However, the validity of a questionnaire to assess HCA intake has hardly been examined. In particular, no biomarker which could serve as an independent measure of habitual HCA intake has been established. Therefore, the validity of a questionnaire to assess HCA intake by means of a biomarker remains to be investigated. In this study, we examined the availability of hair HCAs as a biochemical indicator of dietary intake of HCAs. Study subjects were 20 volunteers (7 men and 13 women) aged 25–57 years, either residents of Tokyo or the neighboring cities in Japan. We collected individual weighed dietary records (DR) over 28 consecutive days. Approximately 3–5 g of hair was collected twice from all subjects before and after DR at intervals of 1–3 months. The mean (S.D.) 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) level of hair was 1376.0 pg/g hair (928.9) and 16.6 ng/g melanin (12.3). A steady increase in the mean PhIP level in hair from the lowest to the highest tertile of the grilled/stir-fried meat intake was observed (P = 0.009), but not in the grilled/stir-fried fish intake (P = 0.461). The PhIP level in hair was highly correlated with the grilled/stir-fried meat intake (r = 0.68) but not with the grilled/stir-fried fish intake (r = 0.28). These observations were made of hair with and without melanin adjustment. The present study indicates that the PhIP level in hair can be used as a biological indicator of dietary intake of HCAs.     

Desacyl ghrelin inhibits the orexigenic effect of peripherally injected ghrelin in rats

Studies showed that the metabolic unlike the neuroendocrine effects of ghrelin could be abrogated by co-administered unacylated ghrelin. The aim was to investigate the interaction between ghrelin and desacyl ghrelin administered intraperitoneally on food intake and neuronal activity (c-Fos) in the arcuate nucleus in non-fasted rats. Ghrelin (13 μg/kg) significantly increased food intake within the first 30 min post-injection. Desacyl ghrelin at 64 and 127 μg/kg injected simultaneously with ghrelin abolished the stimulatory effect of ghrelin on food intake. Desacyl ghrelin alone at both doses did not alter food intake. Both doses of desacyl ghrelin injected separately in the light phase had no effects on food intake when rats were fasted for 12 h. Ghrelin and desacyl ghrelin (64 μg/kg) injected alone increased the number of Fos positive neurons in the arcuate nucleus compared to vehicle. The effect on neuronal activity induced by ghrelin was significantly reduced when injected simultaneously with desacyl ghrelin. Double labeling revealed that nesfatin-1 immunoreactive neurons in the arcuate nucleus are activated by simultaneous injection of ghrelin and desacyl ghrelin. These results suggest that desacyl ghrelin suppresses ghrelin-induced food intake by curbing ghrelin-induced increased neuronal activity in the arcuate nucleus and recruiting nesfatin-1 immunopositive neurons.     

Ontogenetic changes in food intake and digestion rate of the herbivorous marine iguana (Amblyrhynchus cristatus,Bell)

Young reptiles have higher relative energy demands than adults, but the proposed ontogenetic changes in diet to fulfil these demands were not found in the algae-eating Galápagos marine iguanas on Santa Fé. Feeding and digestion rates were investigated to analyse how young achieve higher energy intake. Daily food intake of free ranging marine iguana hatchlings (6–11 months old) was about one third that of adults, but relative intake (g dry mass · g^–1 wet mass · day^–1) was four times higher in the hatchlings. During feeding experiments, relative daily food intake of hatchling marine iguanas was approximately three times higher than that of adults (0.042 vs 0.013 g dry mass · g^–0.8 wet mass · day^–1), and mean gut passage time was two times shorter (5 vs 10 days). The hatchlings also maintained high body temperatures (36.7° C) even under relatively cool day-time air temperatures of 32° C. Apparent digestibility of algal food measured both during feeding trials and by Mn²⁺ AAS (atomic absorption spectrometry) for free-ranging iguanas was 70%, independent of body size and temperature. The red algae prevailing in the diet were high in protein (30% dry mass) and energy (12.1 kJ/g dry mass). Diving iguanas had higher rates of energy intake than intertidal foragers, but daily intake was less. Maintenance of high body temperature enabled hatchlings to achieve high digestion rates and, combined with high relative intake, thus achieve sufficient energy intake for rapid growth despite higher mass specific metabolic rates. Estimates of biomass of marine iguanas and their algal food are given for a section of coastline on Santa Fé.     

Assessment of selenium bioavailability from naturally produced high-selenium soy foods in selenium-deficient rats

We assessed the bioavailability of selenium (Se) from a protein isolate and tofu (bean curd) prepared from naturally produced high-Se soybeans. The Se concentrations of the soybeans, the protein isolate and tofu were 5.2 ± 0.2, 11.4 ± 0.1 and 7.4 ± 0.1 mg/kg, respectively. Male weanling Sprague–Dawley rats were depleted of Se by feeding them a 30% Torula yeast-based diet (4.1 μg Se/kg) for 56 days, and then they were replenished with Se for an additional 50 days by feeding them the same diet containing 14, 24 or 30 μg Se/kg from the protein isolate or 13, 23 or 31 μg Se/kg from tofu, respectively. l-Selenomethionine (SeMet) was used as a reference. Selenium bioavailability was determined on the basis of the restoration of Se-dependent enzyme activities and tissue Se concentrations in Se-depleted rats, comparing those responses for the protein isolate and tofu to those for SeMet by using a slope-ratio method. Dietary supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in glutathione peroxidase activities in blood and liver and in thioredoxin reductase activity in liver. Furthermore, supplementation with the protein isolate or tofu resulted in linear or log-linear, dose-dependent increases in the Se concentrations of plasma, liver, muscle and kidneys. These results indicated an overall bioavailability of approximately 101% for Se from the protein isolate and 94% from tofu, relative to SeMet. We conclude that Se from naturally produced high-Se soybeans is highly bioavailable in this model and that high-Se soybeans may be a good dietary source of Se.     

Tolerance and bioaccumulation of heavy metals in five populations of Cistus ladanifer L. subsp. ladanifer

The effects of heavy metals on the growth, mineral composition (P, K, Fe and Mn) and metal accumulation of five populations of Cistus ladanifer subsp. ladanifer from NE Portugal were investigated in hydroponic experiments. Plants were exposed to increasing concentrations (0–2000 M) of one of eight heavy metals: Cd, Co, Cr, Cu, Mn, Ni, Pb or Zn. Populations of C. ladanifer, whose origin was ultramafic soils (S and UB) or soils developed on basic rocks (B), showed a higher tolerance to the metals Cd, Co, Cr, and Mn, and a considerable degree of tolerance to Ni. In contrast, populations originating on acid-rock soils (M and SC) showed higher tolerance to the metals Cu and Zn. Populations showed different patterns of metal accumulation and distribution in the plant parts, suggesting different mechanisms of metal tolerance are used. The more Cd-, Co- and Mn-tolerant populations (S, UB, B and SC (Cd)) showed accumulation of these three metals in the shoots (shoot:root metal concentration ratios (S:R) > 1). Shoot concentrations of up to 309 g Cd g^–1, 2667 g Co g^–1 and 6214 g Mn g^–1 were found in these populations. The populations, UB and M, showed considerable tolerance to Ni and Zn, respectively. These populations accumulated up to 4164 g Ni g^–1 and 7695 g Zn g^–1 in their shoot tissues, and these metals were efficiently transported from the roots to aerial parts (S:R > 3 (Ni), S:R > 1 (Zn)). In contrast, the S and SC populations maintained higher growth rates in the presence of Ni and Zn, respectively, but showed exclusion mechanisms of metal tolerance: reduced Ni and Zn transport to shoots (S:R < 1). Cistus ladanifer was not able to efficiently transport Cr, Cu or Pb from its roots to its aerial parts (S:R ranged from 0–0.4). The more Cu-tolerant populations, M and SC, showed a greater restriction of Cu transport to the shoots than the ultramafic- or basic-rock populations. Significant changes in the plant mineral composition were found, however, concentrations were generally above mineral deficiency levels. Based on these preliminary results the possible usefulness of this plant for phytoremediation technologies is discussed. However, further investigations are necessary to evaluate its growth and metal accumulation under soil and field conditions.     

Systemic injections of gastro-intestinal peptides alter behavior in rats

Twenty-four male albino rats were given daily intraperitoneal injections of vasoactive intestinal polypeptide (VIP), motilin, human gastrin I (1–17) or the diluent control vehicle at a dose of 100 μg/kg for four consecutive days and food intake, water intake, body weight, and running wheel activity were determined every 24 hours. Animals injected with motilin or human gastrin I (1–17) exhibited decreased food intake relative to those injected with VIP or diluent, which did not differ from each other, although food intake increased reliably over days. The mean water consumption followed the same pattern as that of food intake. As expected from the above results, VIP produced weight gains as compared with rats injected with motilin or gastrin but not reliably more than after diluent. A reliable effect of trials for weight gain was the greatest on day three. Running wheel activity was not affected by injections of human gastrin I (1–17), motilin, or diluent but was reliably decreased by VIP. No significant differences existed across days. Although the results indicate that GI peptides may affect behavior when injected systemically and that like other peptides they have multiple effects, caution is urged in the interpretation of behavioral results at this time.     

Docosahexaenoic acid: Measurements in food and dietary exposure

The Dietary Reference Intakes (DRIs) were established to be an indicator of adequacy of dietary nutrients as well as providing levels for adequacy in reducing risk of chronic diseases such as neurodegenerative diseases, cardiovascular diseases, cancers, diabetes mellitus, etc. One particular nutrient that is increasingly discussed as a potential candidate for the generation of a DRI is the omega-3 (n-3) fatty acid docosahexaenoic acid (DHA) due to its potential benefits in reducing risk for cardiovascular disease, role in resolution of inflammation, its importance in cognitive function in infants and inhibiting the progression of neurodegenerative diseases in the elderly. Each reference value refers to and is predicated on estimates of daily nutrient intake and the goal of this paper is to review these intakes. The confidence of these values is critical in establishing dose–response relationships. This paper reports intake values for DHA and examines how these data were generated and the relative confidence in these values. The adult US population is estimated to consume 80–100 mg/d of DHA based on a nationally representative sample of >8400 individuals as part of the National Health and Nutrition Examination Survey (NHANES). This value and those presented for women and men at various ages appear reasonable and should be used as the basis for establishing an Adequate Intake (AI) for DHA.     

Effect of Bacillus thuringiensis Cry1 Toxins in Insect Hemolymph and Their Neurotoxicity in Brain Cells of Lymantria dispar

Little information is available on the systemic effects of Bacillus thuringiensis toxins in the hemocoel of insects. In order to test whether B. thuringiensis-activated toxins elicit a toxic response in the hemocoel, we measured the effect of intrahemocoelic injections of several Cry1 toxins on the food intake, growth, and survival of Lymantria dispar (Lepidoptera) and Neobellieria bullata (Diptera) larvae. Injection of Cry1C was highly toxic to the Lymantria larvae and resulted in the complete inhibition of food intake, growth arrest, and death in a dose-dependent manner. Cry1Aa and Cry1Ab (5 μg/0.2 g [fresh weight] [g fresh wt]) also affected growth and food intake but were less toxic than Cry1C (0.5 μg/0.2 g fresh wt). Cry1E and Cry1Ac (5 μg/0.2 g fresh wt) had no toxic effect upon injection. Cry1C was also highly toxic to N. bullata larvae upon injection. Injection of 5 μg/0.2 g fresh wt resulted in rapid paralysis, followed by hemocytic melanization and death. Lower concentrations delayed pupariation or gave rise to malformation of the puparium. Finally, Cry1C was toxic to brain cells of Lymantria in vitro. The addition of Cry1C (20 μg/ml) to primary cultures of Lymantria brain cells resulted in rapid lysis of the cultured neurons.     

Association between serum uncarboxylated osteocalcin levels and nutritional intake in Japanese female athletes

[Purpose] The current study aimed to determine the association between serum uncarboxylated osteocalcin (ucOC) levels and dietary vitamin K intake in female Japanese athletes.[Methods] The nutritional profile and food group intake of 52 Japanese female athletes were investigated using a digital photographic method with data obtained from 3-day dietary records. The food groups were categorized into 18 groups in line with the standard tables of food composition in Japan. Fasting blood samples were collected for serum ucOC levels, and dual-energy X-ray absorptiometry (DXA) evaluated body composition and bone parameters.[Results] The results showed that dietary vitamin K intake level was 235 ± 148 µg/day, and approximately 70% (n = 36) of participants consumed more than the adequate intake (AI) level, based on the Dietary Reference Intakes for Japanese females aged 18–29. Serum ucOC levels were negatively associated with daily vitamin K intake (r = −0.388, P = 0.004) and calcium (r = −0.596, P = 0.004) after adjusting for energy intake.[Conclusion] Our study revealed that serum ucOC levels were negatively associated with dietary vitamin K intake in female Japanese athletes. Serum ucOC levels reflected dietary vitamin K intake in female athletes. In summary, female athletes consume more vitamin K than the general population to maintain bone health. Furthermore, our results indicated that serum ucOC levels might be linked to dietary calcium intake.     

Simultaneous and sensitive determination of multiplex chemical residues based on multicolor quantum dot probes

Biotinylated denatured bovine serum albumin (Bt-dBSA)-coated cadmium telluride (CdTe) quantum dot (QD) conjugates were prepared and used to develop the multiplexed fluoroimmunoassay for the simultaneous determination of five chemical residues. An immune complex was formed using avidin as the bridge to link the Bt-dBSA-QDs with the antibodies. Primarily, individual quantitative determinations of five representative chemical residues were carried out based on the different emission properties of the QDs. Five antibodies were then conjugated with the corresponding QDs to establish the indirect competition fluorescent-linked immunosorbent assay (ic-FLISA) for the simultaneous detection of five chemicals in one well of a microplate. The linear range for dexamethason (DEX) was from 0.33 μg/kg to 10 μg/kg, 0.28 μg/kg to 10 μg/kg for gentamicin (GM), 0.16 μg/kg to 25 μg/kg for clonazepam (CZP), 0.17 μg/kg to 10 μg/kg for medroxyprogesterone acetate (MPA) and 0.32 μg/kg to 25 μg/kg for ceftiofur (CEF), respectively. The limit of detection (LOD) for the simultaneous determination of DEX, GM, CZP, MPA and CEF were as low as 0.13 μg/kg, 0.16 μg/kg, 0.07 μg/kg, 0.06 μg/kg and 0.14 μg/kg, respectively. This detection method was used to analyze samples of pork muscle and the recoveries ranged from 61.3% to 80.3% for DEX and from 74.0% to 87.2% for MPA. Further more, good correlation between the novel ic-FLISA and traditional ELISA was demonstrated during the determination of DEX and MPA residues in real samples. The QD-based protocol described here is less time consuming than the classical method and it may be sufficiently flexible to be used in other systems for the simultaneous multicolor detection of the drugs.     

Serum selenium and selenoprotein P status in adult Danes – 8-year followup

Selenium is an essential micronutrient important to human health. The main objective of this study is to describe serum selenium and selenoprotein P status in two samples of the Danish population. In addition, the influence of various factors potentially associated with selenium status was investigated.Blood samples from a total of 817 randomly selected subjects from two cities in Denmark were analyzed. Half of the samples were collected in 1997–1998 and the other half in 2004–2005. Samples from women aged 18–22, 40–45 and 60–65 years, and men aged 60–65 years were selected for this study. All subjects had filled in a food frequency questionnaire (FFQ) and a questionnaire with information about smoking habits, alcohol consumption and exercise habits.Mean serum selenium level was 98.7±19.8 μg/L and median selenoprotein P level was 2.72 (2.18–3.49) mg/L. Serum selenium and selenoprotein P increased with age, and selenoprotein P was higher in men than in women. Serum selenium levels decreased by 5% on average from 1997–98 to 2004–05 (P<0.001), whereas selenoprotein P level increased (P<0.001). The intake of fish correlated weakly with serum selenium level (r=0.14, P<0.001) but not with selenoprotein P level. Smoking status, alcohol intake, exercise habits, BMI and medicine use did not influence selenium status.It is concluded that selenium status in this Danish population is at an acceptable level. No major groups with regard to age, sex or lifestyle factors could be identified as being in risk for selenium deficiency.     

Field fertility of sex-sorted and non-sorted frozen-thawed stallion spermatozoa

In the 2004/2005 breeding season, the fertility of sex-sorted (SS) and non-sorted (NS) frozen stallion spermatozoa from two Hannovarian stallions was compared. A hysteroscopic insemination technique [Morris, L.H., Tiplady, C., Allen, W.R., 2003a. Pregnancy rates in mares after a single fixed time hysteroscopic insemination of low numbers of frozen–thawed spermatozoa onto the uterotubal junction. Equine Vet. J. 35, 197–201] was used to deposit low doses (6, 13 or 25 × 10⁶ frozen–thawed SS or NS spermatozoa) onto the utero-tubal junction at 32 or 38 h after the administration of Chorulon (2500 IU, Intervet). Fertility was low, with one pregnancy (13 × 10⁶ spermatozoa, 500 μL) obtained after artificial insemination with frozen SS spermatozoa (n = 29 cycles) which resulted in the birth of a filly. Two pregnancies were obtained in mares inseminated with 6 × 10⁶ NS spermatozoa in 250 μL (n = 31 cycles). Mares failing to conceive on two experimental cycles were allocated to the conventional insemination group. Insemination with >500 × 10⁶ motile NS frozen–thawed spermatozoa, yielded satisfactory per cycle conception rates (35.5%, 22/62) for both stallions combined and was within the values of their normal fertility as quoted by the stud's records. This suggests that the quality of the frozen semen was acceptable and that the freezing processes yielded viable spermatozoa capable of fertilisation. The poor fertility after hysteroscopic insemination with low doses of sex-sorted or non-sorted spermatozoa from the same stallions may be directly attributable to the low dose insemination conditions with frozen–thawed rather than sex-sorted spermatozoa.     

Validity of a self-administered food frequency questionnaire in the assessment of heterocyclic amine intake using 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) levels in hair

Several case-control studies have reported possible associations between heterocyclic amine (HCA) intake and the risk of cancer. The validity of questionnaires used to assess HCA intake has hardly been examined, however; in particular, no biomarker able to serve as an independent measure of habitual HCA intake has been established. In this study, we examined the validity of HCA intake estimated from a food frequency questionnaire (FFQ) using 2-amino-1-methyl-6-phenylimidazo[4,5-b]pyridine (PhIP) level in hair as a reference method. Study subjects were 20 volunteers (7 men and 13 women) aged 25–57 years residing in Tokyo or neighboring cities in Japan. The subjects completed the FFQ, and gave 3–5 g of hair twice at an interval of 1–3 months for use in establishing validity. Results showed that intakes of PhIP, MeIQ, Trp-P-1, and total HCA by the FFQ were significantly correlated with PhIP levels in hair when adjustment was made for melanin content (r = 0.47, r = 0.50, r = 0.55, and r = 0.51, respectively). The present study indicates that HCA intake estimated from this FFQ provides a reasonable ranking of individuals to allow the analysis of associations between HCA intake and risk of cancer in large-scale epidemiological studies.     

Heavy metal contamination in vegetables grown around peri-urban and urban-industrial clusters in Ghaziabad,India

Heavy metal contamination of agricultural soils resulting from rapid industrialization and urbanization is of great concern because of potential health risk due to dietary intake of contaminated vegetables. The present study aims to evaluate the status of heavy metals contamination of agricultural soils and food crops around an urban-industrial region in India. Transfer factor values of Cu, Cr, Pb, Cd, Zn, and Ni from soil to vegetable was estimated. The mean heavy metal concentrations (mg/kg) in agricultural soils (Cu: 17.8, Cr: 27.3, Pb: 29.8, Cd: 0.43, Zn: 87, Mn: 306.6, Fe: 16984, and Ni: 53.8) were within allowable concentrations for Indian agricultural soil. The concentrations of Pb, Cd, Zn, and Ni in crops/vegetables exceeded the World Health Organization/Food and Agriculture Organization safe limits. Relative orders of transfer of metals from soil to edible parts of the crops/vegetables were Cd > Pb > Ni > Zn > Cu > Cr. The enrichment factors of heavy metals in soil indicated minor to moderately severe enrichment for Pb, Cd, and Ni; minor to moderate enrichment for Zn; no enrichment to minor enrichment for Mn; and no enrichment to moderate enrichment for Cu at different sites. Ecological risk index of soil showed considerable contamination in one of the wastewater irrigated sites.     

Trace Metals (Cd,Co, Cr,Cu, Hg,Ni, Pb,and Zn) in Food Supplements of Marine Origin

We determined the concentrations of Cd, Co, Cr, Cu, Hg, Ni, Pb, and Zn in dietary supplements of marine origin. Four supplement categories were studied; algae, coral, krill, and shark cartilage. A direct mercury analyzer was used for Hg determinations while acid digestions and ICP-AES were used for Cr analysis and ICP-MS for the other trace metals. Algae are the supplements showing the highest concentrations of Pb, Cr, and Ni with respective means of 1.6 mg Pb/kg dry weight (d.w.), 3.2 Cr mg/kg d.w., and 8.0 mg Ni/kg d.w. Krill supplements have the highest levels of Cd, Cu, and Zn with 0.65 mg Cd/kg d.w., 63 mg Cu/kg d.w., and 50 mg Zn/kg d.w., respectively. Shark cartilage supplements show the highest levels of Hg and Co with mean concentrations of 160 μg Hg/kg d.w. and 73 ± 51 μg Co/kg d.w., respectively. No samples in our study exceeded the provisional tolerable daily intakes set by Health Canada, the joint committee of the World Health Organization/Food and Agricultural Organization, or the U.S. Environmental Protection Agency. Nevertheless, Ni and Pb in algae and Hg in shark cartilage may end up contributing to a very significant portion of the allowable daily intake—leaving little room for normal intake through food consumption and other exposure pathways.     

Geochemical cycling of heavy metals in a marine coastal area: benthic flux determination from pore water profiles and in situ measurements using benthic chambers

Concentrations of the heavy metals Cd, Co, Cr, Cu, Fe, Mn, Ni, Pb and Zn were measured in sea water, suspended matter, sediments and pore water samples collected in a coastal area of the middle Tyrrhenian Sea. Concentration factors between pore water (extracted from the first centimeter of the sediments) and the overlying sea water (taken 30 cm above the sea bed) were less than 1 for Cr, Cu and Pb, 1–10 for Cd and Ni, 10–100 for Fe and Co, 100–1000 for Mn, and 1–100 for Zn.The benthic fluxes of heavy metals at the sediment-water interface were measured directly using in situ benthic chambers and calculated using Fick's first law during two experimental periods, one in 1986 and the other in 1988. The fluxes of Cu, Ni, Pb and Zn varied significantly over time; this appeared to be related to their relatively low ( 10) concentration factors. From the benthic chamber experiments, metals with positive fluxes were in the order: Mn > Fe > Co > Cd, while those with negative fluxes were: Zn > Pb > Ni Cu. Fluxes calculated using Fick's Law were: positive – Mn > Fe > Zn (or Zn > Fe) > Ni > Co > Cd, negative fluxes Pb > Cu > Cr.Measured (benthic chamber) and calculated (Fick's first law) fluxes for Co, Cd, Mn, Pb and Fe were comparable within an order of magnitude, although less agreement was found for Cu, Ni and Zn. Removal of Ni and Zn at the sediment-water interface has been proposed to explain the fact that the measured and calculated fluxes have opposite directions for these metals.     

Use of androgenesis for estimating maternal and mitochondrial genome effects on development and oxygen consumption in rainbow trout, Oncorhynchus mykiss

Chromosome set manipulation was used to produce rainbow trout, Oncorhynchus mykiss, with identical nuclear backgrounds, but different maternal backgrounds to determine mitochondrial effects on development rate and oxygen consumption. Significant differences in development rate and oxygen consumption were observed between groups from different females. Development rates ranged from a mean of 317.97 degree days (°d) to 335.25 °d in progeny from different females. Mean oxygen consumption rates ranged from 3.31 μmol O₂ g^− 1 wet mass h^− 1 to 9.66 μmol O₂ g^− 1 wet mass h^− 1. Oxygen consumption and development rate analysis revealed the two slowest developing groups had the highest oxygen consumption rates. Development rate differences between second generation clonal females indicate that mitochondrial genomes play a significant role on early development and are comparable to development rate differences between clonal lines of rainbow trout. These results indicate that selection for mitochondrial genomes could increase growth rates and possibly food conversion ratios in aquaculture species.