bluuebunny/crossref_metadata_2025 huggingface dataset:
Accumulation of cadmium with time in Romney sheep grazing ryegrass-white clover pasture: effect of cadmium from pasture and soil intake
Authors: Lee J , Rounce JR , Mackay AD , Grace ND
Published: November 2004

Cadmium (Cd) concentrations in various tissues of Romney sheep and rates of accumulation, as affected by Cd concentrations in pasture and soil, DM intake, and animal age, were determined in a 25-month study. After weaning, 6 groups of 10 wether lambs were grazed on a low Cd (0.l8 � 0.08 8g Cd/g DM) or high Cd (0.52 � 0.17 8g Cd/g DM) pasture in 3 replicates. The rate of accumulation of Cd (8g /day) into the liver and kidney was greatest in sheep aged about 6 months (for the low and high Cd pastures: kidney 0.27 and 0.56; liver 0.35 and 1 I), after which it declined with age (kidney 0.02 and 0.03: liver <0901 and 0.05; at 28 months of age). Total content of Cd in the organs continued to increase. In 6-month-old animals, 0.25% of total Cd ingested was retained by the kidney and liver, but this proportion decreased to about 0.05% of Cd intake with 28-month-old animals. Net retention of Cd in the fleece-free body as a percentage of daily Cd intake for both the control and treatment animals was estimated between 0- 35 and 0 5%. Except for muscle tissue from sheep in the treatment group, for which the mean Cd concentration was lower than that of the control group (2.0 � 0.24 and 3 9 � 0.63 r)g Cd/g fresh tissue, respectively), Cd concentrations in kidney, liver, thymus, muscle, and lung tissue increased over the first 3 months for both groups of animals. After 2 years, animals on the treatment pastures had approximately 3-fold greater Cd concentrations in liver, kidney, and duodenal tissue tissue than those grazing the control pastures (liver, 361 � 58 v. 97 � 11; kidney, l485 � 200 v. 352f48; duodenal tissue, 32f 4 v. 18f 2.5 t)g Cd/g FW, respectively). At higher Cd intakes, the adaptive effect of increased metallothionein synthesis enabled the animal to be more efficient in binding Cd, which restricted accumulation of Cd in muscle. The regression ([Cd] kidney = -205 + 0. 981Cdintake + 0 - 726Time; r = 0.82, P < 0.001) gave the best fit for the observed Cd concentration in the kidney tissue. Daily Cd intake was also a better predictor of the Cd concentration in liver tissue than the concentration of Cd in pasture by itself ([Cd]liver, = 24.7 + 0.353Cdintake; r = 0.81, P < 0.001). Accurate predictions of the potential for Cd accumulation in young grazing animals will enable more effective management strategies to be implemented to reduce Cd accumulation and therefore minimise the potential impact relating to both environment and market.
Resistance to nematode parasites in Merino sheep: sources of genetic variation
Authors: Eady SJ , Woolaston RR , Mortimer SI , Lewer RP , Raadsma HW , Swan AA , Ponzoni RW
Published: November 2004

Merino sheep representing a range of bloodlines in resource flocks located across Australia were tested for resistance to gastro-intestinal nematodes. These flocks included the JB Pye Flock (Camden, NSW), Katanning Base Flock (Katanning, WA), Turretfield Merino Resource Flock (Rosedale, SA), CSIRO Finewool Flock (Armidale, NSW), and the Trangie D Flock (Trangie, NSW). Faecal egg count (FEC) was used to measure relative resistance of sheep to nematode parasites after either natural or artificial infection with Haemonchus contortus and Trichostrongylus colubriformis. Differences in FEC 0' 33 between strains and between and within bloodlines were examined and the heritability of this trait was estimated. A low proportion of the total variation in parasite resistance could be attributed to strain and bloodline effects (1 and 3.5%, respectively) after either natural or artificial infection. The major source of genetic variation was found within bloodlines (22.2% of total variation), with individual sires showing a wide range in parasite resistance. Paternal half-sib heritability estimates for FEC 0' 33 were significant (P < 0.05) in 9 of the 11 analyses and ranged from 0.07 to 0.42, with a weighted average of 0.22. The influence of the environmental effects of sex, age of dam, birth-rearing rank, and day of birth were also investigated, and were found to be only occasionally significant, accounting for a small proportion (0.3-2.2%) of variation. Management group effects both prior to and at the time of measurement were often significant, and accounted for 2.2-19.4% of variation in FEC. Correction of FEC for effects other than management group would seem to add little to precision of selection. These results have demonstrated that significant genetic variation for nematode parasite resistance exists within a wide range of Merino bloodlines, and within-flock selection of resistant sires appears to be an effective method of improving this trait in Merino sheep.
Serological responses against Pseudomonas aeruginosa in Merino sheep bred for resistance or susceptibility to fleece rot and body strike
Authors: Gogolewski RP , Nicholls PJ , Mortimer SI , Mackintosh JA , Nesa M , Ly W , Chin JC
Published: November 2004

Lines of medium-wool Peppin Merino sheep selected for resistance (R) or susceptibility (S) to fleece rot and body strike were compared serologically following 4 weekly intradermal inoculations of live I, the predominant bacterial species associated with fleece rot. There was essentially no evidence of fleece rot or body strike in these animals prior to experimentation. In Exp. 1, the 1989-born ewe progeny of the R and S lines were studied (nR = 52; nS = 49). Over 12 weeks, average serum antibody responses against P. aeruginosa were greater in R sheep but the differences were generally non-significant at P = 0.05. The apparent differences in antibody response between R and S lines were largely attributable to the effects of some individual sires in the R line. In a second experiment, the 1990-born ewe progeny of the R and S lines (nR = 75; nS = 76), and the ewe progeny of a line unselected on fleece rot and body strike resistance (F line; nF = 53), were studied. Following inoculation with live I, the mean serum antibody responses of the R and S sheep, which were not different before inoculation, were significantly higher for R sheep for the first 8 weeks of a 10-week observation period. The mean responses of the F line generally fell between the R and S responses. One week after the first inoculation, sire effects in the R line were much greater than for the S and F lines, but thereafter sire effects were similar among lines. Taken together, these results suggest that direct selection for the R or S genotype produced lines of sheep with divergent serological responsiveness following intradermal inoculation with P. aeruginosa; however, in one generation the effects of some individual sires appeared to be largely responsible for these differences.
Shade-stimulated growth and nitrogen uptake by pasture grasses in a subtropical environment
Authors: Wilson JR
Published: November 2004

Fibrous feeds constrain voluntary feed intake by ruminants through a complex of interacting animal and plant factors. The animal factors are briefly assessed indicating some control over digesta load in the rumen and that only small particles (<1 mm screen size) achieve ready passage from the rumen. There is evidence that retention of small particles may be prolonged because their movement from the rumen to reticulum may be restricted by their buoyancy and entrapment within the digesta raft in the rumen. Ingestive chewing and rumination effort varies with feed type, is greater for stem than leaf and increases with feed maturity. It is still not clear from animal studies whether passage rate and VFI are limited more by the time to break large particles to small particles or by the hindrance of small particle passage from the rumen. Digestion in rumen decreases the physical grinding energy needed to comminute feed, but it is not readily shown that this makes a difference to efficiency of animal rumination. Anatomical characteristics of leaves and stems of tropical and temperate grasses and legumes are analysed to assess their influence on the ease and pattern of breakdown, and the characteristics of the resultant fibre particles. Epidermal and vascular structures, and microbial digestion, determine the initial breakdown of organs which is fast in leaves of legumes and high quality temperate grasses, but slow in tropical grass leaves. All stems require a high chewing effort to facilitate swallowing of feed and passage of particles from the rumen. Some tissue components directly enter the 'fines' fraction, the rest (vascular strands in isolated or composite form) become the large particle fraction. Rumination is essential to degrade these to small particles. It is hypothesised that inaccessibility of cell walls for microbial attack limits digestive weakening in both large and small particles. A conceptual framework summarizing the breakdown pattern for different feed groups is presented. Potential future opportunities for overcoming these intake constraints associated with modification of rumen microbes and plant anatomical structure are discussed.
Effect of temperature and moisture potential on germination and emergence in Lotus sp
Authors: Blumenthal MJ , Aston SC , Pearson CJ
Published: November 2004

Two controlled cabinet experiments compared the germination of 6 Lotus genotypes over a range of temperature (0-40�C) and moisture potentials (0 to -1.2 MPa). A field experiment compared the emergence of 5 Lotus genotypes over 18 sowing dates. Lotus cornzculatus cv. Grasslands Goldie. L. uliginosus, Grasslands Maku, G4703, G4704. and cv. Sharnae were included in both the controlled cabinet and field experiments. Lotus suaveolens CPI 35903 was included in the controlled cabinet experiments only and Trifolium repens cv. Haifa was included as a control in the field study. Of the commercially available Lotus cultivars, Grasslands Goldie provides the greatest flexibility in terms of sowing date in coastal New South Wales and could be successfully sown even in late autumn and winter as it had the lowest base temperature for germination and field emergence. G4703, Sharnae, and G4704 had a lower base moisture potential for germination than the other 3 Lotus genotypes but this was not translated to better field emergence. Lotus suaveolens had an extremely low base temperature for germination (l�C) compared with L. uliginosus cv. Grasslands Maku (6.4�C). Hybridisation of this species with both L. corniculatus and L. uliginosus could result in germplasm capable of germinating better at low temperature but still able to maintain the perenniality, rhizomatous habit, and presence of condensed tannin of L. uliginosus.
Leaf development in relation to infection by Stagonospora nodorum and Septoria tritici in wheat
Authors: Peters BA , Loughman R , Prinzio Pdi , Di Prinzio P
Published: November 2004

Disease and phenology were compared in 2 wheat cultivars (Aroona and Spear) differing in disease resistance and maturity, at early (April-May) to late (June) sowing dates in 1991 and 1992. The cultivars had similar rates of leaf development but the longer season cultivar Spear averaged up to one leaf more on the main stem than the midseason cultivar Aroona, depending on sowing date. The extra leaf production which delayed flag leaf emergence on Spear compared to Aroona at early sowings was associated with lower disease levels in 1991. The occurrence of leaf rust may have diminished this advantage in 1992. Resistance to Septoria tritici in Aroona did not affect disease progress compared to Spear. A comparison of disease over a segment of accumulated thermal time revealed that in 1991, under average seasonal conditions, the earliest sowing experienced the most disease. In 1992, above average late spring rainfall occurred and time of sowing had little influence on disease over the same segment of thermal time. We conclude that a cultivar appropriate for early sowing on the south coast should exhibit increasing leaf production in response to early sowing. This can result in a reduction of disease severity on the upper leaves through disease escape.
Streptococcus caprinus is ineffective as a rumen inoculum to improve digestion of mulga (Acacia aneura) by sheep
Authors: Miller SM , Brooker JD , Phillips A , Blackall LL
Published: November 2004

This study examined the distribution of Streptococcus caprinus in domestic and feral ruminants, and the effect of rumen inoculation with S. caprinus on nitrogen digestion in mulga-fed sheep. S. caprinus is a tannin-resistant rumen bacterium found in feral goats and may play a role in alleviating the nutritive depressing effects of high concentrations of plant tannins in these animals. S. caprinus was present in samples of rumen fluid from feral goats and feral camels but was not detectable in rumen fluid from sheep and domestic goats that had not previously grazed forages containing condensed tannins. A proportion of sheep, domestic goats, and cattle grazing in mulga paddocks, with either feral goats or camels, had detectable populations of S. caprinus. Pure cultures of S. caprinus grown in vitro were successfully placed in the rumen of sheep; however, nitrogen digestion was unaffected by rumen inoculation. Interactions between several populations of micro-organisms may therefore be involved in achieving improvements in protein digestion.
Forage quality of kikuyu (Pennisetum clandestinum): the effect of time of defoliation and nitrogen fertiliser application and in comparison with perennial ryegrass (Lolium perenne)
Authors: Reeves M , Fulkerson WJ , Kellaway RC
Published: November 2004

This study, conducted on the north coast of New South Wales, determined the optimal time to defoliate kikuyu (Pennisetum clandestinum Hochst ex chiov.) in terms of pasture quality in relation to the number of leaves per tiller. It also compared the quality of well-managed kikuyu grass and ryegrass (Lolium perenne L.) pasture to determine the nutrients in kikuyu likely to limit milk production. The crude protein (CP), P, and K concentrations of individual leaves declined; Ca and Mg increased; and Na levels remained constant with increasing age. These changes in individual leaves were reflected in the quality of kikuyu available above the 5-cm stubble height. The proportion of green leaf available above the 5-cm stubble height declined whilst the proportion of stem and dead material increased markedly after 4.5 leaves per tiller had regrown. These changes were reflected in a substantial decline in organic matter digestibility (OMD) and CP of herbage. Between 0900 and 1500 hours, water-soluble carbohydrate (WSC) levels in kikuyu above the 5-cm stubble height increased at a rate of 5 g/kg dry matter (DM) per hour, reaching maximum levels during the mid afternoon. Kikuyu fertilised at a high rate of N fertiliser contained significantly higher nitrate levels than that receiving moderate levels (3.12 v. 0. 67 g/kg DM, respectively). There was a linear increase in the levels of nitrate as the CP of forage exceeded 230 g/kg DM. Kikuyu and ryegrass samples plucked to simulate forage consumed by milking cows were obtained in the midst of the growing season for each species. Kikuyu had a lower OMD than ryegrass (733 v. 842 g/kg DM) but contained higher levels of neutral detergent fibre (600 v. 400 g/kg DM). High levels of CP and low content of WSC in kikuyu compared with ryegrass resulted in a much lower ratio WSC: CP (0.09 v. 0.36, respectively). Kikuyu contained 50% less Ca than ryegrass, much of which would be expected to be bound to oxalates and thus unavailable to grazing stock. The concentration of Na in kikuyu was extremely low compared with ryegrass (0.15 v. 3.67 g/kg DM, respectively). The most desirable stage of regrowth of kikuyu on which to graze lactating dairy cows, in terms of a compromise between forage quality and quantity, appears to be at 4.5 leaves/tiller. However, even at this stage, various innate nutrient deficiencies would appear to restrict milk production to 15-16 L milk/cow.day.
Ultraviolet plumage reflectance distinguishes sibling bird species
Authors: Bleiweiss Robert
Published: November 2004

Realistic studies of plumage color need to consider that many birds can see near-UV light, which normal humans cannot perceive. Although previous investigations have revealed that UV-based plumage reflectance is an important component of various intraspecific social signals, the contribution of UV signals to inter-specific divergence and speciation in birds remains largely unexplored. I describe an avian example of an interspecific phenomenon in which related sympatric species that appear similar to humans (sibling species) differ dramatically in the UV. Both UV video images and physical reflectance spectra indicate that the dorsal plumage of the tanager
Anisognathus notabilis
has a strong UV-limited reflectance band that readily distinguishes this species from its sibling congener
Anisognathus flavinuchus
. The main human-visible distinction between
A. notabilis
(olive back) and coexisting
A. flavinuchus
(black back) also occurs among different geographic populations of
A. flavinuchus
. Notably, however, olive- and black-backed taxa interbreed (differentiated populations of
A. flavinuchus
) unless the additional UV distinction is present (
A. notabilis
vs.
A. flavinuchus
). Thus, UV-based reflectance can be an essential component of plumage divergence that relates to reproductive isolation, a key attribute of biological species.
Self-generated diversity produces “insurance effects” in biofilm communities
Authors: Boles Blaise R. , Thoendel Matthew , Singh Pradeep K.
Published: November 2004

Diversity generally protects communities from unstable environmental conditions. This principle, known as the “insurance hypothesis,” has been tested in many different ecosystems. Here we show that the opportunistic pathogenPseudomonas aeruginosaundergoes extensive genetic diversification during short-term growth in biofilm communities. The induced genetic changes are produced by arecA-dependent mechanism and affect multiple traits, including the behavior of the bacteria in biofilms. Some biofilm-derived variants exhibit an increased ability to disseminate, whereas others manifest accelerated biofilm formation. Furthermore, the presence of these functionally diverse bacteria increases the ability of biofilms to resist an environmental stress. These findings suggest that self-generated diversity in biofilms provides a form of biological insurance that can safeguard the community in the face of adverse conditions.
Impaired adrenal stress response in Toll-like receptor 2-deficient mice
Authors: Bornstein Stefan R. , Zacharowski Paula , Schumann Ralf R. , Barthel Andreas , Tran Nguyen , Papewalis Claudia , Rettori Valeria , McCann Samuel M. , Schulze-Osthoff Klaus , Scherbaum Werner A. , Tarnow Jörg , Zacharowski Kai
Published: November 2004

Septicemia is one of the major health concerns worldwide, and rapid activation of adrenal steroid release is a key event in the organism's first line of defense during this form of severe illness. The family of Toll-like receptors (TLRs) is critical in the early immune response upon bacterial infection, and TLR polymorphisms are frequent in humans. Here, we demonstrate that TLR-2 deficiency in mice is associated with reduced plasma corticosterone levels and marked cellular alterations in adrenocortical tissue. TLR-2-deficient mice have an impaired adrenal corticosterone release after inflammatory stress induced by bacterial cell wall compounds. This defect appears to be mediated by a decrease in systemic and intraadrenal cytokine expression, including IL-1, tumor necrosis factor α, and IL-6. Our data demonstrate a link between the innate immune system and the endocrine stress response. The critical role of TLR-2 in adrenal glucocorticoid regulation needs to be considered in patients with inflammatory disease.
Subfield symmetric spaces for finite special linear groups
Authors: Shoji Toshiaki , Sorlin Karine
Published: November 2004

Let

G
G

be a connected algebraic group defined over a finite field

F

q

{\mathbf F}_q

. For each irreducible character

ρ
\rho

of

G
(

F

q
r

)

G(\mathbf F_{q^r})

, we denote by

m
r

(
ρ
)

m_r(\rho )

the multiplicity of

1

G
(

F

q

)

1_{G({\mathbf F}_q)}

in the restriction of

ρ
\rho

to

G
(

F

q

)

G({\mathbf F}_q)

. In the case where

G
G

is reductive with connected center and is simple modulo center, Kawanaka determined

m
2

(
ρ
)

m_2(\rho )

for almost all cases, and then Lusztig gave a general formula for

m
2

(
ρ
)

m_2(\rho )

. In the case where the center of

G
G

is not connected, such a result is not known. In this paper we determine

m
2

(
ρ
)

m_2(\rho )

, up to some minor ambiguity, in the case where

G
G

is the special linear group.

We also discuss, for any

r
≥
2

r \ge 2

, the relationship between

m
r

(
ρ
)

m_r(\rho )

with the theory of Shintani descent in the case where

G
G

is a connected algebraic group.
Application of Petri net theory for modelling and validation of the sucrose breakdown pathway in the potato tuber
Authors: Koch Ina , Junker Björn H. , Heiner Monika
Published: November 2004

Motivation: Because of the complexity of metabolic networks and their regulation, formal modelling is a useful method to improve the understanding of these systems. An essential step in network modelling is to validate the network model. Petri net theory provides algorithms and methods, which can be applied directly to metabolic network modelling and analysis in order to validate the model. The metabolism between sucrose and starch in the potato tuber is of great research interest. Even if the metabolism is one of the best studied in sink organs, it is not yet fully understood.

Results: We provide an approach for model validation of metabolic networks using Petri net theory, which we demonstrate for the sucrose breakdown pathway in the potato tuber. We start with hierarchical modelling of the metabolic network as a Petri net and continue with the analysis of qualitative properties of the network. The results characterize the net structure and give insights into the complex net behaviour.

Availability: Free availability of the Petri net editor PED, the animator PedVisor via http://www-dssz.informatik.tu-cottbus.de/~wwwdssz, and the analysis tool Integrated Net Analyser (INA) via http://www.informatik.hu-berlin.de/~starke/ina.html

Contact:  Ina.Koch@tfh-berlin.de
A new species of Karydomys (Rodentia, Mammalia) and a systematic re‐evaluation of this rare Eurasian Miocene hamster
Authors: Mörs Thomas , Kalthoff Daniela C.
Published: November 2004

We describe a new species of the rare and enigmatic cricetid genus Karydomys from the middle Miocene Ville Formation of the Hambach lignite mine in north‐west Germany. The locality Hambach 6C has yielded the first substantial records of Karydomys from central Europe. For the first time, all molar positions are well‐documented, including the previously unknown m2. The excellent molar material allows us to distinguish Karydomys wigharti sp. nov. from the western European species K. zapfei. Karydomys wigharti predominantly occurs at localities that are correlated with the upper part of the Mammalian Neogene biozone MN 5. The new finds are of palaeobiogeographic significance for the genus Karydomys, since Hambach 6C represents the north‐westernmost outpost of terrestrial Miocene faunas in Europe. In addition, the locality has yielded the first lower jaws and incisors of the genus. Both the jaw morphology, and the ornamentation and microstructure of the incisor enamel offer new arguments for a systematic classification of Karydomys into the subfamily Democricetodontinae. We assume that the scarcity of the two large European Karydomys species can be explained by their special adaptation to wet habitats, which are poorly documented in the fossil record.
A new problematic Early Ordovician univalve mollusc from France
Authors: Peel John S. , Horný Radvan J.
Published: November 2004

Lamaureriella vizcainoi gen. et sp. nov., from the Montagne Noire region of southern France, is a coiled, laterally compressed, bilaterally symmetrical mollusc in which prominent folds in the apertural margin produce a characteristic spiral plication across each lateral surface. Similar plications are present in technophorid rostroconchs but the prominent coiling and lack of a pegma suggest that Lamaureriella is a helcionelloid. It is the second such genus described from Early Ordovician rocks.
Lower Devonian Polyplacophora from New South Wales, Australia
Authors: Hoare Richard D. , Farrell John R.
Published: November 2004

Silicified polyplacophorans are common in the Lower Devonian Garra Formation in New South Wales. Four taxa occur within the lower 237 m of the formation at 14 horizons associated with an abundant and diverse fauna. Chelodes calceoloides Etheridge ranges through the section. New taxa are Chelodes cordatus sp. nov., Acutichiton depressolatus sp. nov., and Jugochiton patulus gen. and sp. nov. A single plate of an indeterminate genus occurs in the lower portion of the Camelford Limestone.
Palaeobotanical applications of incident‐light darkfield microscopy
Authors: Thomas Barry A. , Cleal Christopher J. , Barthel Manfred
Published: November 2004

Incident‐light darkfield microscopy permits the direct observation of cellular structure of some plant fossils without the need for maceration. It allows the study of leaf epidermis and sporangial structure where it was previously impossible.
Workfare: the Subjection of Labour
Authors: Attas Daniel , De‐Shalit Avner
Published: November 2004

abstract  When viewed as a question of distributive justice the evaluation of workfare typically reflects exclusively on the distribution of income: do the physically capable have a justified claim for state support, or is it fair to demand from those who do work to subsidise this support? Rarely is workfare appraised in terms of how it affects other parties such as employers or other workers, and on the structural effects the pattern of incentives it generates brings about, or as an issue of distributive justice related to a more extensive range of objects of distribution such as access to pleasing jobs.

We propose to evaluate workfare by looking at its effects more broadly: (1) we discuss and dismiss on empirical grounds the two most common arguments in favour of workfare, namely that workfare develops self‐reliance among participants and it is more economical in the use of altruism among taxpayers. (2) We suggest that workfare focuses on work as a burden and as a means to income, ignoring other beneficial aspects that are conducive to the worker’s self expression. These other benefits are distributed unevenly between two main groups: the privileged well off and the disadvantaged. (3) we argue that workfare functions as a mechanism to preserve these privileges to one class of workers at the expense of another. Or, to put it the other way, the payment of unconditional welfare to the long term unemployed might be justified as one method of mitigating unjustified privileges.
Shifts in the food of Nile tilapia,Oreochromis niloticus(L.) in Lake Victoria, Kenya
Authors: Njiru M. , Okeyo‐Owuor J. B. , Muchiri M. , Cowx I. G.
Published: November 2004

Studies of the food of introduced Nile tilapia,Oreochromis niloticus(L.) with respect to size, habitat and season were conducted between November 1998 and October 2000 in Kenyan waters of Lake Victoria. Stomach contents of 1980 specimens collected by demersal trawl and seining were analysed. Nile tilapia originally known to be herbivorous, feeding mostly on algae has diversified its diet to include insects, fish, algae and plant materials. The major diet of fish <5 cm total length was zooplankton whereas bigger fish included a wider range of food items in their diet. There was spatial variation in diet with insects and algae dominating in the gulf and open water habitats respectively. There was no seasonal variation in the food items ingested and diel feeding regime indicated thatO. niloticusis a diurnal feeder. The shift in diet could be due to ecological and environmental changes in Lake Victoria, which have been associated with changes in composition and diversity of fish and invertebrate fauna, emergence and dominance of different flora including water hyacinthEichhornia crassipes(Mart.) Solms‐Laub., and algae communities. The feeding habit ofO. niloticusis discussed in the context of changes occurring in the lake.
Teduglutide ([Gly2]GLP‐2) protects small intestinal stem cells from radiation damage
Authors: Booth C. , Booth D. , Williamson S. , Demchyshyn L. L. , Potten C. S.
Published: November 2004

Abstract.  Glucagon‐like peptide‐2 and its dipeptidyl peptidase (DP‐IV) resistant analogue teduglutide are trophic for the gastrointestinal epithelium. Exposure increases villus height and crypt size and results in increased overall intestinal weight. As these effects may be mediated through stimulation of the stem cell compartment, they may promote intestinal healing and act as potential anti‐mucositis agents in patients undergoing cancer chemotherapy. A study was initiated to investigate the protective effects of teduglutide on the murine small intestinal epithelium following gamma‐irradiation using the crypt microcolony assay as a measure of stem cell survival and functional competence. Teduglutide demonstrated intestinotrophic effects in both CD1 and BDF1 mouse strains. In BDF1 mice, subcutaneous injection of GLP‐2 or teduglutide (0.2 mg/kg/day, b.i.d.) for 14 days increased intestinal weight by 28% and resulted in comparable increases in crypt size, villus height and area. Teduglutide given daily for 6 or 14 days prior to whole body, gamma‐irradiation significantly increased crypt stem cell survival when compared with vehicle‐treated controls. The mean levels of protection over a range of doses provided protection factors from 1.3 to 1.5. A protective effect was only observed when teduglutide was given before irradiation. These results suggest that teduglutide has the ability to modulate clonogenic stem cell survival in the small intestine and this may have a useful clinical application in the prevention of cancer therapy‐induced mucositis.
Predictors of life satisfaction of Korean nurses
Authors: Lee Haejung , Hwang Sunkyung , Kim Jeongsoon , Daly Barbara
Published: November 2004

Aim.  This paper reports a study to identify the levels of work satisfaction, burnout and life satisfaction among Korean hospital nurses and the relative importance of negative and positive work outcomes (burnout and work satisfaction) in explaining the variance of life satisfaction of nurses.

Background.  Previous research has demonstrated that work outcomes such as job satisfaction and burnout can affect overall life satisfaction. It is not yet known, however, whether positive and negative aspects of work outcomes exert equally strong or varying degrees of effect, nor whether the relationships demonstrated primarily in Western cultures also are present in other cultures. Given the widespread shortage of nurses, it is important to identify areas for organizational interventions that have the greatest potential for improving both recruitment and retention of nurses.

Methods.  A cross‐sectional correlational design was used. A survey was undertaken with 194 nurses from general hospitals of 300 beds or more in southern Korea between May 1999 and March 2000. Paper and pencil self‐rating questionnaires were used to gather information. Data were analysed using descriptive statistics, Pearson correlations and multiple regressions.

Results.  Korean nurses reported moderate levels of life satisfaction, with low levels of work satisfaction and high levels of burnout. Burnout explained more variance in life satisfaction than work satisfaction. Those who experienced higher personal accomplishment and lower emotional exhaustion and who were satisfied with their professional status and did not work at night reported higher life satisfaction.

Conclusions.  This study highlights the relative importance of negative work outcomes on nurses’ overall well‐being. Strategies to reduce emotional exhaustion, enhance nurses’ personal accomplishment and satisfaction with professional status, and accommodate shift preferences for work scheduling were suggested. Replicating this study with nurses from other geographic areas using random selection will be needed to increase the generalizability of the findings.
Professional career development for male nurses
Authors: Yang Cheng‐I , Gau Meei‐Ling , Shiau Shu‐Jen , Hu Wei‐Herng , Shih Fu‐Jin
Published: November 2004

Aim.  The aim of this paper is to report a study to: (a) explore Taiwanese male nurses’ motivations for becoming a nurse; (b) reveal their professional developmental process in nursing; (c) understand the difficulties hindering their professional development from both professional and gender aspects; and (d) identify the strategies they use to cope with these difficulties.

Background.  Hindered by historical, cultural, economic and warfare factors, the proportion of male nurses in Taiwan remains low. Taiwanese male nurses’ career development process has not been well investigated yet.

Methods.  A descriptive qualitative research design was used, with a convenience sample of 15 male nurses (mean age 30·8 years) with a Bachelor's degree in Nursing Science. Data were collected by semi‐structured interviews and analysed by content analysis.

Results.  Taiwanese male nurses’ entrance into the nursing profession involved three phases: pre‐study, study and employment. The difficulties encountered during career development were related to the gender expectations of patients and the general public. The nurses received support more from superiors than from colleagues. The strategies they used included (a) improving their professional knowledge and skills to obtain higher levels of satisfaction and better opportunities for promotion; (b) thinking aggressively about job promotion; (c) choosing specialist departments as appropriate environments for graduate study and personal growth; and (d) changing their professional track for personal growth.

Conclusions.  Based on the nature of nursing work and clinical experiences, Taiwanese male nurses believed that nursing was a profession suitable for both men and women. Their preparation for career development started at the pre‐study phase. The major strategies they used were related to a strong desire for personal growth and professional promotion. Finally, a conceptual framework was developed to depict this complex phenomenon.
Molecular characterization of the tobacco SET domain protein NtSET1 unravels its role in histone methylation, chromatin binding, and segregation
Authors: Yu Yu , Dong Aiwu , Shen Wen‐Hui
Published: November 2004

Plants contain a great number of genes encoding a distinctive class of SET domain proteins which harbor a plant‐specific N‐terminal part together with a C‐terminal part showing highest sequence similarity to the catalytic domain of the yeast CLR4, the human SUV39H1 and G9a histone‐methyltransferases (HMTases). Here we show that NtSET1, a representative member of this class from tobacco, methylated both K9 and K27 of histone H3 in vitro. Ectopic expression of NtSET1, by an inducible promoter, increased the amount of dimethylated H3K9 and induced chromosome‐segregation defects in tobacco BY2 cells. Deletion analyses show that the HMTase activity, the association with specific chromatin regions and with condensed chromosomes, and the cellular effects largely depended on the C‐terminal region including the SET domain of the protein. Nevertheless, the N‐terminal part of NtSET1 was capable of targeting the green fluorescent protein to interphase chromatin. Finally, we show that NtSET1 bound LHP1, the Arabidopsis homolog of animal heterochromatin protein 1 (HP1), and that LHP1 co‐localized with heterochromatin containing high amounts of dimethylated H3K9, suggesting a role for NtSET1 in heterochromatic function. Taken together, our results provide new insights into the molecular and global chromatin‐binding activities of this particular class member of plant SET domain proteins.
Functional differentiation of endosomes in Arabidopsis cells
Authors: Ueda Takashi , Uemura Tomohiro , Sato Masa H. , Nakano Akihiko
Published: November 2004

Endocytosis plays an important role in plant physiology, but how endocytic organelles are organized remains unknown. We present the evidence that endosomes are functionally differentiated in Arabidopsis cells. Two types of Rab5‐related GTPases are localized on distinct population of endosomes in a partially overlapping manner. Ara7 and Rha1 are on an early type of endosomes with AtVamp727, where recycling of plasma membrane proteins occurs. In contrast, the plant‐unique Rab5, Ara6, resides on distinct endosomes with the prevacuolar SNAREs. Partially overlapping localization of Ara6 and Ara7/Rha1 with reciprocal gradients suggests maturation of endosomes from one to the other.
Chloride fluxes in lily pollen tubes: a critical reevaluation
Authors: Messerli Mark A. , Smith Peter J.S. , Lewis Robert C. , Robinson Kenneth R.
Published: November 2004

Microelectrodes, made from a Cl−‐selective liquid ion exchanger previously used to measure putative Cl‐ fluxes in Lilium longiflorum pollen tubes, were characterized. The electrodes were poorly selective, possessing only about 10‐fold selectivity for Cl− over other anions tested. They had only 2.4‐fold selectivity for Cl− over the anionic form of the H+ buffer, MES, indicating that the electrode can indirectly detect H+ gradients. Apparent anion influx was detected along the pollen tube shafts and at the grains while apparent anion efflux was detected near the tip of the tube. During oscillating growth, the peak of the oscillating apparent anion efflux at the tip occurred, on average, 7.9 sec after the peak of the growth oscillations. Consideration of the previously characterized H+ fluxes in lily pollen grains and tubes, as well as the poor anion selectivity of the Cl− electrodes, indicates that the putative Cl− fluxes are in fact changes in the anionic concentration of the buffer resulting from H+ gradients and not changes in Cl− concentration. The claim of a central role for Cl− in lily pollen tube growth is further undermined by the fact that these tubes grow at the same rate if the Cl− content of the growth medium is reduced to trace levels (≤31 μm), and that the grains have only small reserves of Cl−. These results lead to the conclusion that Cl− fluxes are not a significant component of pollen tube growth and Cl− itself is not required for growth.
Local fever illness classifications: implications for home management of malaria strategies
Authors: Nsungwa‐Sabiiti Jesca , Källander Karin , Nsabagasani Xavier , Namusisi Kellen , Pariyo George , Johansson Annika , Tomson Göran , Peterson Stefan
Published: November 2004

Background  The Ugandan Ministry of Health has adopted the WHO Home Based Fever Management strategy (HBM) to improve access to antimalarial drugs for prompt (<24 h) presumptive treatment of all fevers in children under 5 years. Village volunteers will distribute pre‐packed antimalarials free of charge to caretakers of febrile children 2 months to 5 years (‘Homapaks’).

Objective  To explore the local understanding and treatment practices for childhood fever illnesses and discuss implications for the HBM strategy.

Methods  Focus Group Discussions were held with child caretakers in three rural communities in Kasese district, West Uganda, and analysed for content in respect to local illness classifications and associated treatments for childhood fevers.

Results  Local understanding of fever illnesses and associated treatments was complex. Some fever illness classifications were more commonly mentioned, including ‘Fever of Mosquito’, ‘Chest Problem’, ‘the Disease’, ‘Stomach Wounds’ and ‘Jerks’, all of which could be biomedical malaria. Although caretakers refer to all these classifications as ‘fever’ treatment differed; some were seen as requiring urgent professional western treatment and others were considered severe but ‘non‐western’ and would preferentially be treated with traditional remedies.

Conclusions  The HBM strategy does not address local community understanding of ‘fever’ and its influence on treatment. While HBM improves drug access, Homapaks are likely to be used for only those fevers where ‘western’ treatment is perceived appropriate, implying continued delayed and under‐treatment of potential malaria. Hence, HBM strategies also need to address local perceptions of febrile illness and adapt information and training material accordingly.
Nationwide HIV prevalence survey in general population in Niger
Authors: Boisier P. , Ouwe Missi Oukem‐Boyer O. N. , Amadou Hamidou A. , Sidikou F. , Ibrahim M. L. , Elhaj Mahamane A. , Mamadou S. , Sanda Aksenenkova T. , Hama Modibo B. , Chanteau S. , Sani A. , Louboutin‐Croc J.‐P.
Published: November 2004

A national population‐based survey was carried out in Niger in 2002 to assess HIV prevalence in the population aged 15–49 years. A two‐stage cluster sampling was used and the blood specimens were collected on filter paper and tested according to an algorithm involving up to three diagnostic tests whenever appropriate. Testing was unlinked and anonymous. The refusal rate was 1.1% and 6056 blood samples were available for analysis. The adjusted prevalence of HIV was 0.87% (95% CI, 0.5–1.3%) and the 95% CI of the estimated number of infected individuals was 22 864–59 640. HIV‐1 and HIV‐2 represented, respectively, 95.6% and 2.9% of infections while dual infections represented 1.5%. HIV positivity rate was 1.0% in women and 0.7% in men. It was significantly higher among urban populations than among rural ones (respectively, 2.1% and 0.6%, P < 10−6). Using logistic regression, the variables significantly related to the risk of being tested positive for HIV were urban housing, increasing age and being either widowed or divorced. The estimate from the national survey was lower than the prevalence assessed from antenatal clinic data (2.8% in 2001). In the future, the representativeness of sentinel sites should be improved by increasing the representation of rural areas accounting for more than 80% of the population. Compared with other sub‐Saharan countries, the HIV prevalence in Niger is still moderate. This situation represents a strong argument for enhancing prevention programmes and makes realistic the projects promoting an access to potent antiretroviral therapies for the majority.
How can river‐estuarine planktonic copepods survive river floods?
Authors: UEDA Hiroshi , TERAO Ayumi , TANAKA Masaru , HIBINO Manabu , ISLAM Md. Shahidul
Published: November 2004

Distribution of brackish‐water zooplankton was surveyed in the Chikugo River estuary, Japan, at 3‐h intervals for 24 h, including several hours when the river was heavily flooded because of rainfall and discharge from an upstream dam. The populations of the dominant copepods Pseudodiaptomus inopinus and Sinocalanus sinensis were concentrated in the mixing zone of the salt wedge before river flooding. During the period of flooding, they were almost completely swept out from the river, but examination of water trapped by a sediment grab sampler revealed that adults of Pseudodiaptomus inopinus were aggregated immediately above the bottom of the submerged channel outside the river mouth. After the flood, aggregations of both species appeared again in the river together with the salt wedge, and the proportion of adults in the aggregations became significantly higher than before. These results suggest that immature copepods suffer population losses through river flooding, but that the copepods can survive such flooding by means of both behavioral and reproductive mechanisms; that is, adult copepods maintain their position on the bottom of submerged channels outside the river mouth during a river flood and replace the population loss through reproduction after the flood. Channels outside river mouths are thus regarded as important topographic refuges for river‐estuarine zooplankton to survive a flood.
Network analysis of potential migration routes for Oriental White Storks (Ciconia boyciana)
Authors: SHIMAZAKI Hiroto , TAMURA Masayuki , DARMAN Yury , ANDRONOV Vladimir , PARILOV Mikhail P. , NAGENDRAN Meenakshi , HIGUCHI Hiroyoshi
Published: November 2004

From 1998 through to 2000, we satellite‐tracked the movements of 13 Oriental White Storks (Ciconia boyciana) on their autumnal migration in order to identify their important stopover sites for preserving links from the Russian Far East breeding sites to the wintering sites in south‐eastern China. New analytical methods of satellite tracking data were employed to derive robust information on the locations of stay sites, the number of stopovers made during migration, and the distance traveled without making stopovers. Based on the derived information, we modeled a stay site network as an abstraction of the storks’ potential migration routes from their breeding sites to wintering sites. Using network analysis techniques, we explored how the loss of stopover sites could affect the connectivity of potential migration routes. The results suggested that if the seashore stopover sites facing Bohai Bay in eastern China were lost, the storks’ wintering sites along the Yangtze River in south‐eastern China would be isolated. Among the seashore stopover sites, Jiantuozhi Gley Mire (39.185°N, 118.627°E), located on the northern seashore of Bohai Bay, was considered particularly important for migrating storks, because it was used every year by the storks we tracked. If conservation needs of this critically located site fail to be addressed, the stay site network of storks can create weak links in the chain of migration and, if ‘broken’, storks will have great difficulties in completing their autumnal migration.
A barium marking method using an ultrathin bronchoscope with virtual bronchoscopic navigation
Authors: ASANO Fumihiro , MATSUNO Yoshihiko , IBUKA Takashi , TAKEICHI Naoko , OYA Hideki
Published: November 2004

Abstract:  CT scanning in a 77‐year‐old woman showed a ground‐glass opacity pattern shadow (9 × 7 mm) in the right lower lobe. To allow identification of the location of the lesion during thoracoscopic surgery, preoperative barium marking was performed using an ultrathin bronchoscope and virtual bronchoscopic navigation. Virtual bronchoscopy was performed based on thin‐section CT images, and virtual bronchoscopic images to the target sites were obtained. Subsequently, using virtual bronchoscopic images to right B8aiiβx, B6biiβ for navigation, an ultrathin bronchoscope was advanced to this site under direct observation. A special catheter for ultrathin bronchoscopy was advanced to sites near the lesion, and barium was infused. Barium was clearly observed by radiographic fluoroscopy during thoracoscopic surgery and was useful for determining the area for resection. Pathological examination of the resected specimen revealed atypical adenomatous hyperplasia. There were no complications with this method, and a number of target areas could be readily marked in a short time. This method may be useful before thoracoscopic surgery for small peripheral pulmonary lesions.
Extraneural metastasis of the pineal germinoma via ventriculoperitoneal shunt
Authors: Poon Tak‐Lap , Ho Wai‐Shing , Pang Kai‐Yuen , Wong Chi‐Keung
Published: November 2004

Extraneural metastasis of pineal germinoma is an infrequent event. We report a case of a 19‐year‐old boy who had pineal germinoma and was successfully treated with irradiation. He was diagnosed with abdominal metastasis of pineal germinoma via ventricuolperitoneal shunt 6 years afterwards. The disease was controlled with surgery and systemic chemotherapy.