Mitochondrial gene content, arrangement and composition compared in African and Asian schistosomes

Complete sequences were obtained for the coding portions of the mitochondrial (mt) genomes of Schistosoma mansoni (NMRI strain, Puerto Rico; 14415 bp), S. japonicum (Anhui strain, China; 14085 bp) and S. mekongi (Khong Island, Laos; 14072 bp). Each comprises 36 genes: 12 protein-encoding genes (cox1-3, nad1-6, nad4L, atp6 and cob); two ribosomal RNAs, rrnL (large subunit rRNA or 16S) and rrnS (small subunit rRNA or 12S); as well as 22 transfer RNA (tRNA) genes. The atp8 gene is absent. A large segment (9.6 kb) of the coding region (comprising 14 tRNAs, eight complete and two incomplete protein-encoding genes) for S. malayensis (Baling, Malaysian Peninsula) was also obtained. Each genome also possesses a long non-coding region that is divided into two parts (a small and a large non-coding region, the latter not fully sequenced in any species) by one or more tRNAs. The protein-encoding genes are similar in size, composition and codon usage in all species except for cox1 in S. mansoni (609 aa) and cox2 in S. mekongi (219 an), both of which are longer than homologues in other species. An unexpected finding in all the Schistosoma species was the presence of a leucine zipper motif in the nad4L gene. The gene order in S. mansoni is strikingly different from that seen in the S. japonicum group and other flatworms. There is a high level of identity (87-94% at both the nucleotide and amino acid levels) for all protein-encoding genes of S. mekongi and S. malayensis. The identity between genes of these two species and those of S. japonicum is less (56-83% for amino acids and 73-79 for nucleotides). The identity between the genes of S. mansoni and the Asian schistosomes is far less (33-66% for amino acids and 54-68% for nucleotides), an observation consistent with the known phylogenetic distance between S. mansoni and the other species. (C) 2001 Elsevier Science B.V. All rights reserved.

Composition of pecan cultivars Wichita and Western Schley [Carya illinoinensis (Wangenh.) K. Koh] grown in Australia

Pecans from the cultivars Wichita and Western Schley [Carya illinoinensis (Wangenh.) K. Koch] collected over three years were analyzed for the following constituents: total lipid content; fatty acid profiles; sucrose content; protein; total dietary fiber; the minerals magnesium, calcium, potassium, sulfur, phosphorus, boron, copper, iron, manganese, sodium, zinc, and aluminum; vitamin C; and lipase; and lipoxygenase activities. Year of harvest and cultivar had little effect on the composition of the pecans. Overall, protein content was the only constituent that differed between pecans grown in Australia and those grown in the United States. This difference is probably related to differences in growing location and horticultural practices between the two countries.

Larval diet affects number of femoral 'brush' scales in male Helicoverpa punctigera moths (Lepidoptera : Noctuidae)

Males of Helicoverpa punctigera (Wallengren) show considerable variation in the number of femoral scales on the prothoracic legs. Such intraspecific variation in adult morphology could indicate the presence of undetected sibling species, or it may be related to larval diet. Helicoverpa putactigera is polyphagous, and different host plant species are likely to represent diets of different quality. Femoral lengths and the numbers of femoral scales on the prothoracic legs were therefore determined from: (i) individuals that had been collected as larvae from various host species in the field; and (ii) individuals that had been laboratory-reared, in split-family tests, on different diets, namely cotton, lucerne, sowthistle and artificial diet. Host plant species (and therefore presumably diet quality) influenced femoral length of H. punctigera males and, perhaps in conjunction with this, the number of femoral scales on the fore leg. The rearing experiment indicated, in addition, that the effect of host plant quality varies with larval stage, and that the pattern of this variation across the immature stages is dependent on host plant species. The recorded variation in the morphology of field-collected H. punctigera males is therefore most readily explained as a consequence of different individuals developing (at least for most of their larval life) on different host plant species, with diet quality varying significantly with species. The relevance of these results for insect developmental studies and evolutionary interpretations of host relationships is outlined.

Effects of concentrated viral communities on photosynthesis and community composition of co-occurring benthic microalgae and phytoplankton

Marine viruses have been shown to affect phytoplankton productivity; however, there are no reports on the effect of viruses on benthic microalgae (microphytobenthos). Hence, this study investigated the effects of elevated concentrations of virus-like particles on the photosynthetic physiology and community composition of benthic microalgae and phytoplankton. Virus populations were collected near the sediment surface and concentrated by tangential flow ultrafiltration, and the concentrate was added to benthic and water column samples that were obtained along a eutrophication gradient in the Brisbane River/Moreton Bay estuary, Australia. Photosynthetic and community responses of benthic microalgae, phytoplankton and bacteria were monitored over 7 d in aquaria and in situ. Benthic microalgal communities responded to viral enrichment in both eutrophic and oligotrophic sediments. In eutrophic sediments, Euglenophytes (Euglena sp.) and bacteria decreased in abundance by 20 to 60 and 26 to 66%, respectively, from seawater controls. In oligotrophic sediments, bacteria decreased in abundance by 30 to 42% from seawater controls but the dinoflagellate Gymnodinium sp. increased in abundance by 270 to 3600% from seawater controls, The increased abundance of Gymnodinium sp. may be related to increased availability of dissolved organic matter released from lysed bacteria. Increased (140 to 190% from seawater controls) initial chlorophyll a fluorescence measured with a pulse-amplitude modulated fluorometer was observed in eutrophic benthic microalgal incubations following virus enrichment, consistent with photosystem II damage. Virus enrichment in oligotrophic water significantly stimulated carbon fixation rates, perhaps due to increased nutrient availability by bacterial lysis. The interpretation of data from virus amendment experiments is difficult due to potential interaction with unidentified bioactive compounds within seawater concentrates. However, these results show that viruses are capable of influencing microbial dynamics in sediments.

Post-ruminal protein supply and N retention of weaner sheep fed on a basal diet of lucerne hay (Medicago sativa) with increasing levels of quebracho tannins

The ability of low to moderate levels (

Canopy carbon and oxygen isotope composition of 9-year-old hoop pine families in relation to seedling carbon isotope composition, growth, field growth performance, and canopy nitrogen concentration

Carbon isotope composition (delta C-13), oxygen isotope composition (delta O-18), and nitrogen concentration (N-mass) of branchlet tissue at two canopy positions were assessed for glasshouse seedlings and 9-year-old hoop pine (Araucaria cunninghamii Ait. ex D. Don) trees from 22 open-pollinated families grown in 5 blocks of a progeny test at a water-limited and nitrogen-deficient site in southeastern Queensland, Australia. Significant variations in canopy delta C-13, delta O-18, and N-mass existed among the 9-year-old hoop pine families, with a heritability estimate of 0.72 for branchlet delta C-13 from the upper inner canopy position. There was significant variation in canopy delta C-13 of glasshouse seedlings between canopy positions and among the families, with a heritability estimate of 0.66. The canopy delta C-13 was positively related to canopy N-mass only for the upper outer crown in the field (R = 0.62, p < 0.001). Phenotypic correlations existed between tree height and canopy delta C-13 (R = 0.37-0.41, p < 0.001). Strong correlations were found between family canopy delta C-13 at this site and those at a wetter site and between field canopy delta C-13 and glasshouse seedling delta C-13. The mechanisms of the variation in canopy delta C-13 are discussed in relation to canopy photosynthetic capacity as reflected in the N-mass and stomatal conductance as indexed by canopy delta O-18.

Habitat use, diet and body size of Heard Island weevils

Habitat use, diet and body-size variation are examined in weevils from Heard Island. with specific attention being given to the Ectemnorhinus viridis species complex. E. viridis shows marked altitudinal variation in body size and vestiture, but there are no consistent associations between body size and diet. nor are there consistent among-individual differences in conventional taxonomic characters. Thus, the status of E. viridis as a single, variable species is maintained. This species occurs from sea level to 600 rn and it feeds on vascular plants and bryophytes. Canonopsis sericeus also feeds on bryophytes and vascular plants and occurs over a narrower altitudinal range. Palirhoeus eatoni is restricted to the surpralittoral zone where it feeds on marine algae and lichens. Bothrometopus brei,is and B. gracilipes both feed on cryptogams, with the former species occurring from sea level to 450 m. and the latter from 50 to 550 m above sea level. In all species, males are smaller than females and there is a size cline such that populations from higher elevations are smaller than those at lower altitudes. This cline is the reverse of that found on the Prince Edward Islands which, unlike Heard Island, lie to the north of the Antarctic Polar Frontal Zone. This difference in body-size clines between weevils on the two island groups is ascribed to the shorter growing season on the colder Heard Island. The information presented here supports previous ideas regarding the evolution of the Ectemnorhinus-group of weevils on the South Indian Ocean Province Islands, although it suggests that subsequent tests of these hypotheses would profit from the inclusion of molecular systematic work.

Effect of restricted feed intake on early reproductive development in Large White gilts

Forty-five Large White gilts were used to study the effect of energy intake from 28 to 176 d of age on body composition and reproductive development. From 28 to 60 d, the gilts were fed ad libitum a 16.6 MJ DE/kg, 24% crude protein and 1.3% total lysine diet. From 61 d of age three dietary treatments were used; 1) ad libitum access to feed (15.6 MJ DE/kg, 21% crude protein and 1.07% total lysine) (H), 2) feed offered at 75% (M) of the previous days intake of H, and 3) feed offered at 60% (L) of the previous days intake of H. ADG from 61 to 176 d of age was (p <0.05) affected by treatment. Although live weight at 176 d of age did not differ (p >0.1) the H gilts had higher (p <0.08) carcass weights than the M or L gilts. Back fat depths were similar (p >0.1) for all treatments at 115 d of age, however by 176 d of age M and H gilts were fatter (p <0.1) than L gilts. The mean lipid deposition (LD) from 115 to 176 d of age for L gilts (78.9 g/d) was less (p <0.05) than for M gilts (143.6 g/d) and H gilts (135.6 g/d). There were no differences between treatments for protein deposition (PD) over the same period. More (p <0.05) H gilts (n=8) attained puberty (first observed estrus) than either M gilts or L gilts (n=4 for both). Follicle numbers were similar (p >0.1) across treatments. For gilts that attained puberty, H gilts had fewer (p <0.05) follicles (13.5) than M gilts (19.7) and L gilts (21.3). For gilts with follicular development, H gilts had the heaviest (458.7 g) reproductive tract weight (RTW). However, for those that attained puberty, L gilts had the heaviest RTW. RTW were lowest for those with no follicular development. Energy restriction had a negative impact on puberty attainment, i.e. it took longer to reach puberty. However, for gilts that attained puberty, the number of follicles was greater for those on lower feed intakes. It would appear that rate of fat deposition, but not necessarily the total amount of fat, plays an important role in puberty attainment.

The impact of nutrition support on body composition in cancer outpatients receiving radiotherapy

This study investigated the change in body composition in 36 cancer outpatients receiving radiotherapy to the head and neck area (mean age: 63 ± 15 years) randomised to receive either nutrition intervention (NI; n=15) or usual care (UC; n=21). Body weight and composition were measured at the commencement of radiotherapy and 3 months later. The UC group lost significantly more weight; mean decrease = 4.3 kg, than the NI group: mean decrease = 1.1 kg (t(30)=-2.5, p=0.019). Fat-free mass loss was significantly higher in the UC group with a mean loss of 2.2 kg versus 0.3 kg in the NI group (t(30)=- 2.3, p=0.029). Body composition as measured by foot-to-foot bioelectrical impedance analysis provides more information than weight alone and can allow for tailoring of NI.