bluuebunny/crossref_metadata_2025 huggingface dataset:
Comparison of Schistosoma mansoni irradiated cercariae and Sm23 DNA vaccines
Authors: GANLEY‐LEAL L. M. , GUARNER J. , TODD C. W. , DA'DARA A. A. , FREEMAN G. L. , BOYER A. E. , HARN D. A. , SECOR W. E.
Published: September 2005

Immunization with defined antigens is generally less effective at inducing host protection against experimental infection with Schistosoma mansoni than vaccination with attenuated infective cercariae. We predicted that quantitative and/or qualitative differences existed between the immune responses generated to attenuated cercariae and those induced by defined antigens. Thus, we compared immune responses typically associated with protection in the murine model between animals vaccinated with attenuated cercariae and mice immunized with DNA encoding Sm23, a schistosome integral membrane protein that has previously been shown to confer protection. Mice vaccinated three times with attenuated cercariae demonstrated higher levels of protection than Sm23‐vaccinated animals but spleen cells from Sm23 DNA vaccinated mice produced significantly higher levels of schistosome antigen‐specific IFN‐γ. Both vaccines induced similar levels of Sm23‐specific antibody and post‐challenge dermal inflammation. However, the pulmonary inflammatory responses following challenge were much less pronounced in DNA immunized animals compared to those receiving irradiated cercariae. Thus, although Sm23 DNA vaccination effectively induced parasite‐specific IFN‐γ and antibody responses, it failed to evoke other critical responses needed for optimal vaccine efficacy.
Nitrogen delivery to maize via mycorrhizal hyphae depends on the form of N supplied
Authors: TANAKA YOKO , YANO KATSUYA
Published: September 2005

Arbuscular mycorrhizal fungi can enhance nutrient acquisition by a plant via their extraradical hyphae. This is particularly true for phosphorus, but the case for nitrogen (N) has been less clear. In our growth systems there was a small air‐gap between root and hyphal compartments, which eliminated diffusion of nutrients between compartments. Moreover, our methods allowed us to distinguish between nitrate and ammonium. We found that N transfer to Zea maize L. depends on the sources fed to the hyphae of Glomus aggregatum Schenck & Smith. In experiment 1, despite the fact that plant demand for N was already met, plants received 10 times as much 15N from ammonium than from nitrate. In experiment 2, 74% of shoot‐N was derived from the slow‐release urea added to the hyphal compartment while only 2.9% was derived from the nitrate‐N. Intraradical hyphae isolated from roots contained a considerable amount of 15N in the cell wall even when 15N‐nitrate was the source. We conclude that the mycorrhizal fungus can rapidly deliver ammonium‐N to the plants, and that while the fungus can absorb nitrate, it apparently lacks the capacity to transfer it to the plant.
Screening plants for salt tolerance by measuring K+ flux: a case study for barley
Authors: CHEN Z. , NEWMAN I. , ZHOU M. , MENDHAM N. , ZHANG G. , SHABALA S.
Published: September 2005

Development of salt‐tolerant genotypes is central both to remediation of salinity‐affected land and to meet increasing global food demand, which has been driving expansion of cropping into marginal areas. The bottleneck of any breeding programme is the lack of a reliable screening technique. This study tested the hypothesis that the ability of plants to retain K+ under saline conditions is central to their salt tolerance. Using seven barley cultivars contrasting in salt tolerance (CM72, Numar, ZUG293, ZUG95, Franklin, Gairdner, ZUG403), a comprehensive study was undertaken of whole‐plant (growth rate, biomass, net CO2 assimilation, chlorophyll fluorescence, root and leaf elemental and water content) and cellular (net fluxes of H+, K+, Na+ and Ca2+) responses to various concentrations of NaCl (20–320 m m). Na+ selective microelectrodes were found to be unsuitable for screening purposes because of non‐ideal selectivity of the commercially available Na+ LIX. At the same time, our results show very strong negative correlation between the magnitude of K+ efflux from the root and salt tolerance of a particular cultivar. K+ efflux from the mature root zone of intact 3‐day‐old seedlings following 40 min pretreatment with 80 m m NaCl was found to be a reliable screening indicator for salinity tolerance in barley. As a faster and more cost‐effective alternative to microelectrode measurements, a procedure was developed enabling rapid screening of large numbers of seedlings, based on amount of K+ leaked from plant roots after exposure to NaCl.
Sap salinity effects on xylem conductivity in two mangrove species
Authors: LÓPEZ‐PORTILLO JORGE , EWERS FRANK W. , ANGELES GUILLERMO
Published: September 2005

Xylem sap salinity and conductivity were examined in two mangrove ecosystem tree species. For Avicennia germinans, extracted xylem sap osmotic potentials ranged from −0.24 to −1.36 MPa versus −0.14 to −0.56 MPa for Conocarpus erectus. Xylem sap of Conocarpus did not vary in osmotic potential between sites nor between predawn and midday. In Avicennia, values were more negative at midday than predawn, and also more negative at hypersaline than hyposaline sites. After removing embolisms, specific conductivity (Ks) was measured as a function of salinity of the artificial xylem sap perfusion. For both species the lowest Ks values, about 70% of the maximum Ks, were obtained when stems were perfused with deionized water (0 mm; 0.0 MPa) or with a 557‐mm saline solution (−2.4 MPa). Higher Ks values were obtained in the range from −0.3 to −1.2 MPa, with a peak at −0.82 ± 0.08 MPa for Avicennia and −0.75 ± 0.08 MPa for Conocarpus. The variations in Ks values with minima both at very low and very high salt concentrations were consistent with published results for swelling and shrinking of synthetic hydrogels, suggesting native hydrogels in pit membranes of vessels could help regulate conductivity.
Are the carbon costs of seed production related to the quantitative and qualitative performance? An appraisal for legumes and other crops
Authors: MUNIER‐JOLAIN NATHALIE G. , SALON CHRISTOPHE
Published: September 2005

In the past great efforts have been made to gain a thorough understanding of the processes involved in carbon fixation but the fate of the acquired carbon has been somewhat neglected, although this aspect is crucial for improving yield performance without diminishing the quality of the harvested organs. To contribute to the crucial debate on that topic the aim of the present study was to propose some unbiased components concerning in particular grain legumes: ‘Is there any antagonism between high yield and increased nutritional quality, with a focus on protein content?’ An original approach has been used to study the impact of the modification of seed composition on the crop production, which combines theoretical calculations of energetic cost and field yield data. When applied to a wide range of species with varying seed composition, a plurispecific negative relationship between the theoretical carbon costs of seed production and the observed yields was demonstrated. The high‐throughput of genetic markers could result in large‐scale screening of seed quality parameters and such studies, while evaluating the impact of seed composition on crop yield, could also be used to provide data to forecast the economic impact of a new line with an original composition compared with its economically enhanced value.
Photosynthesis and carbohydrate metabolism in tobacco leaves during an incompatible interaction with Phytophthora nicotianae
Authors: SCHARTE JUDITH , SCHÖN HARDY , WEIS ENGELBERT
Published: September 2005

The metabolic and cellular changes in source leaves of Nicotiana tabacum L. cv SNN during an incompatible interaction with Phytophthora nicotianae van Breda de Haan were investigated and compared with defence reactions. Hypersensitive cell death was preceded by a rapid and highly localized shift to non‐assimilatoric metabolism. During the first 6 h post infection (hpi), reactive oxygen species (ROS) accumulated. Callose was deposited at the interface of adjacent mesophyll cells (≥1 hpi), the export of sucrose collapsed and its content in the apoplast increased. Stomata closed and photosynthetic flux was reallocated from CO2 assimilation in favour of photorespiration. This was accompanied by an increase in respiration, glucose‐6‐phosphate dehydrogenase (G6PDH) activity, apoplastic invertase and hexose content. Later (>6 hpi) the photosynthetic electron transport chain was interrupted and photosynthesis completely collapsed. This was accompanied by a further increase in apoplastic invertase and carbohydrates, respiration and oxidative pentose phosphate pathway (OPPP) and followed by further burst in ROS release. Hypersensitive cell death did not appear until photosynthesis completely declined. Photosynthesis was visualized by chlorophyll‐a fluorescence imaging on a macro‐ and microscopic scale. Decline in photosynthesis and defence reactions were highly localized processes, which occur in single mesophyll cells. We propose that in photoautotrophic leaves, photosynthesis and assimilatory metabolism must be switched off to initiate respiration and other processes required for defence. An early blockage of intercellular sugar transportation, due to callose deposition, in conjunction with enhanced apoplastic invertase activity could facilitate this metabolic shift.
Ascorbate promotes emission of mercury vapour from plants
Authors: BATTKE FLORIAN , ERNST DIETER , HALBACH STEFAN
Published: September 2005

Mercury vapour (Hg°) emission from plants contributes to the atmospheric mercury cycle. Although a part of this Hg° emission originates from Hg(II) uptake by the roots, the question how terrestrial plants reduce Hg(II) has not been addressed so far. Young barley plants grown on a hydroponic cultivation containing Hg(II) increased the Hg° emission significantly. Homogenates of barley leaves added to dissolved Hg(II) induced a powerful volatilization at alkaline but not at acidic pH. The same pH dependence and emission kinetic together with the highest reduction capacity was observed for ascorbic acid as compared to other phytoreductants. The electrochemical potentials of the reactions involved suggest an electron transfer from NADPH via GSH and ascorbate to Hg(II). The results support the assumption of a novel mechanism how plants transfer reduction equivalents from the antioxidative defense system via ascorbate to reduce Hg(II) ions, thus counteracting mercury toxicity by volatilizing the metal. This effect appears to be assisted by other light‐dependent processes such as transpiration and ascorbate synthesis.
Leaf growth dynamics of two congener gymnosperm tree species reflect the heterogeneity of light intensities given in their natural ecological niche
Authors: LAI I‐LING , SCHARR HANNO , CHAVARRIA‐KRAUSER ANDRES , KÜSTERS RALF , WU JIUNN‐TZONG , CHOU CHANG‐HUNG , SCHURR ULRICH , WALTER ACHIM
Published: September 2005

Chamaecyparis obtusa var. formosana and Chamaecyparis formosensis are congener gymnosperm tree species native to Taiwan cloud forests; occupying different niches there. While the seedlings of C. formosensis occur predominantly under bright conditions in large forest gaps, seedlings of C. obtusa var. formosana are mainly found below the canopy of mature forests or in small gaps. It is well known that congener species occupying different niches typically differ in several ecophysiological and morphological traits, but the differences in growth dynamics of such species are still totally unclear, as the diurnal growth dynamics of gymnosperm leaves have not been investigated before. Modern methods of digital image sequence processing were used in this study to analyse the leaf growth dynamics of the two species. We found that both species show similar base–tip gradients and pronounced diurnal growth rhythms with maxima in the evening. Differences between the two species concerning their growth dynamics correlated closely with their ecological amplitudes and abundances. Chamaecyparis obtusa var. formosana grew faster than C. formosensis in low light intensity, typical for closed‐canopy situations, and reacted quickly by increasing or decreasing growth rate when light intensity changed within a range typically found below small canopy gaps. In contrast to this, C. formosensis grew better in light intensities typical for open vegetation situations, but reacted slower towards changes of light intensity. Based on those results, the hypothesis can be developed that fluctuations of leaf growth dynamics reflect heterogeneities of the light environment within the niche occupied by a given species.
Cold‐induced repression of the rice anther‐specific cell wall invertase gene OSINV4 is correlated with sucrose accumulation and pollen sterility
Authors: OLIVER SANDRA N. , VAN DONGEN JOOST T. , ALFRED SANJEEV C. , MAMUN EZAZ A. , ZHAO XIAOCHUN , SAINI HARGURDEEP S. , FERNANDES SUSSAN F. , BLANCHARD CHRISTOPHER L. , SUTTON BRUCE G. , GEIGENBERGER PETER , DENNIS ELIZABETH S. , DOLFERUS RUDY
Published: September 2005

Low temperatures during rice (Oryza sativa L.) pollen development cause pollen sterility and decreased grain yield. We show that the time of highest sensitivity to cold coincides with the time of peak tapetal activity: the transition of the tetrad to early uni‐nucleate stage (young microspore, YM stage). Low temperatures at this stage of pollen development result in an accumulation of sucrose in the anthers, accompanied by decreased activity of cell wall bound acid invertase and depletion of starch in mature pollen grains. Expression analysis of two cell wall (OSINV1, 4) and one vacuolar (OSINV2) acid invertase genes showed that OSINV4 is anther‐specific and down‐regulated by cold treatment. OSINV4 is transiently expressed in the tapetum cell layer at the YM stage, and later from the early binucleate stage in the maturing microspores. The down‐regulation of OSINV4 expression in the tapetum at YM may cause a disruption in hexose production and starch formation in the pollen grains. In a cold‐tolerant cultivar, OSINV4 expression was not reduced by cold; sucrose did not accumulate in the anthers and starch formation in the pollen grains was not affected.
Liver transplant in Hawaii: the survival of a small centre
Authors: Wong Linda L , Limm Whitney , Cheung Alan , Noguchi Hiroji
Published: September 2005

Abstract:  Although many report the importance of case volume in complex cases, liver transplantation (LT) can be carried out successfully in a small centre. During a 11.5‐yr period, 88 patients underwent LT in a single transplant centre in Hawaii. Indications for LT were primarily hepatitis C (n = 49) and hepatitis B (n = 13) and 22 patients (25%) had hepatocellular cancer (HCC) on explanted liver. There was no primary graft nonfunction, one retransplant for recurrent hepatitis C and two late hepatic artery thromboses, which did not require a retransplant. One patient developed partial portal vein thrombosis related to a hypercoagulable state and was rescued with anticoagulation. Of the 22 patients with HCC, 18 are alive, two died from recurrent disease (253 and 1428 d post‐LT, respectively), one died because of a ruptured hepatic artery aneurysm (151 d) and one from complications caused by noncompliance (723 d). One‐, 3‐ and 5‐yr survival rates were 89%, 82% and 71%, respectively. Mean survival was 3034.9 d. During this time period, 142 liver resections, 77 pancreatic resections and 43 splenorenal shunts were performed by this group of surgeons. Because of the recent explosion of information on case volumes and centres of excellence, LT can be performed successfully at a small centre. Other major hepatobiliary/transplant procedures can help the surgeons maintain their operative skills. A smaller LT program may require a longer period of evolution, but it can provide a service for a geographically isolated population that would otherwise have limited opportunity for LT.
Successful use of oral ganciclovir for the treatment of intrauterine cytomegalovirus infection in a renal allograft recipient
Authors: Puliyanda D.P. , Silverman N.S. , Lehman D. , Vo A. , Bunnapradist S. , Radha R.K. , Toyoda M. , Jordan S.C.
Published: September 2005

Abstract: Congenital cytomegalovirus (CMV) infection occurs in approximately 1% of newborns and is the leading infectious cause of congenital birth defects. Female renal allograft recipients who develop CMV infection during pregnancy are at risk for both graft dysfunction and fetal morbidity. DNA‐based analysis of amniotic fluid (AF) from at‐risk pregnancies has been suggested as an adjunct/substitute for traditional culture. We have shown that CMV‐polymerase chain reaction of AF is a useful diagnostic test for congenital CMV infection. Using this test we diagnosed CMV infection in the fetus of a 30‐year‐old renal transplant recipient. As termination was not an option for the family, the patient was extensively counseled and treated with oral ganciclovir. This resulted in clearance of the virus from the AF and the delivery of a healthy newborn girl, free of CMV disease. This is the first reported case to our knowledge of successful use of maternal ganciclovir to treat intrauterine CMV infection in a pregnant renal transplant recipient.
A renal transplant patient with intractable hiccups and review of the literature
Authors: Rosenberger J. , Veseliny E. , Bena L. , Roland R.
Published: September 2005

Abstract: Intractable hiccups in transplanted patients may be caused by various medical conditions including infections. We report a case of a 44‐year‐old man who suffered from intractable hiccups after cadaveric kidney transplantation. We identified 3 different hiccup periods with different causes: 1) steroid and anesthetics use, 2) severe ulcerose herpetic and mycotic esophagitis, and 3) pleuropneumonia caused by nosocomial methicillin‐resistant Staphylococcus epidermidis and pulmonary abscess requiring thoracic surgery.
Attitudes and knowledge of colorectal cancer and screening in Hong Kong: A population‐based study
Authors: WONG BENJAMIN CY , CHAN ANNIE OO , WONG WAI M , HUI WAI M , KUNG HSIANG F , LAM SHIU K
Published: September 2005

Background:  Colorectal cancer (CRC) ranks third of all cancer mortalities in Hong Kong. CRC screening can reduce mortality. However, participation in the CRC screening program depends on the knowledge and attitude of the population. The aim of this study is to investigate the knowledge and attitude towards CRC screening in the Hong Kong population.

Methods:  One thousand and thirty‐three patients were interviewed by telephone survey. Knowledge and attitudes were assessed by using questionnaires.

Results:  Only 8.9% of the respondents were able to mention that CRC was the second commonest cancer cause of death; 4.5% believed they would have a higher chance of developing CRC as compared to other cancers, and 7.4% could mention one of the screening methods. Approximately half (50.3%) were unable to identify any available screening venue. Approximately one‐third (29.5%) indicated that they would definitely join a free CRC screening program, but the percentage dropped to 7.9% when a paid screening program was offered. Some (30.4%) of the respondents had the wrong impression that they did not require CRC screening because they were asymptomatic. Multivariate analysis showed that the independent predictor for participating in free screening was the concern level of getting CRC, while that for a paid screening program was a positive family history of CRC and the concern level. The concern level was dependent on a positive family history and knowledge of CRC.

Conclusion:  The general population in Hong Kong had deficient knowledge of CRC and screening. Education on the impact of CRC and beneficial effects of CRC screening should be offered before launching a CRC screening program.
Hepatitis C virus‐NS3P in relation to p53, p21waf, mdm2, p21‐ras and c‐erbB2 in hepatocarcinogenesis
Authors: BAHNASSI ABEER A , ZEKRI ABDEL‐RAHMAN N , EL‐HOUSSINI SOUMAYA , MOKHTAR NADIA M , ABDEL‐AZIZ ASRAF O , SHERIF GHADA M , EL‐MISHAD ABLA M , KHALED HUSSEIN M
Published: September 2005

Background:  The non‐structural protein 3 (NS3P) of hepatitis C virus (HCV) genome was linked to the neoplastic transformation of normal hepatocytes in chronically infected patients. However, the exact mechanisms involved in this process are unidentified yet, especially in the Egyptian population where the commonest type is genotype 4.

Methods:  We investigated 32 HCV reverse transcriptase–polymerase chain reaction (RT‐PCR) positive hepatocellular carcinoma (HCC) cases and 18 morphologically normal hepatic tissues distant to tumors (MNT) for the correlation between HCV‐NS3P, p53, p21waf, mdm2, p21ras and c‐erbB2 and DNA content by immunohistochemistry and image analysis.

Results:  The NS3P expression was lower in HCC (65.6%) than in MNT (94.4%) patients. The expression level of studied genes in HCC was: p53 (56.25%), p21waf (43.7%), mdm2 (59.4%), p21‐ras (73.3%) and c‐erbB2 (75%). Whereas in MNT, it was 22.2, 61.1, 44.4, 41.2 and 77.8%, respectively. The NS3P expression showed a significant correlation with the presence of cirrhosis, chronic active hepatitis (CAH) and tumor grade (P < 0.05). c‐erbB2 overexpression and p21waf loss were higher in MNT than in HCC patients, however, this did not reach a statistically significant level. There was a statistically significant correlation between NS3P, c‐erbB2 and p21waf (P < 0.01). There was also a significant correlation between p21waf loss and CAH (P = 0.01) as well as between mdm2, c‐erbB2 and cirrhosis (P = 0.025 and 0.001) in HCC cases. There was a statistically significant difference in the ploidy status between HCC and MNT, but there was no significant relationship between the ploidy status and other clinicopathological features.

Conclusion:  The carcinogenic effect of NS3P is probably exerted at an early stage of HCC possibly through a pathway involving c‐erbB2 and p21waf alterations. In contrast, p53, p21ras and mdm2 alterations are late events in hepatocarcinogenesis and are usually associated with an aggressive phenotype.
Assessing genetic susceptibility to diabetic nephropathy
Authors: TANAKA NOBUE , BABAZONO TETSUYA
Published: September 2005

SUMMARY:  Diabetic nephropathy is a serious complication of diabetes and the leading cause of end‐stage renal disease. Studies indicate both environmental and genetic factors contribute to the development and progression of diabetic nephropathy. In particular, epidemiological evidence shows a familial clustering of nephropathy in siblings with diabetes, supporting an important role of genetic susceptibility in the pathogenesis of diabetic nephropathy.

A common approach in genetic research is assessment of candidate gene polymorphisms using case‐control analysis; a number of studies have evaluated predictable candidate genes for diabetic nephropathy. In contrast, only a few studies have used a whole genome approach, such as scanning of micro‐satellite markers, in the assessment of genetic susceptibility to diabetic nephropathy. A whole genome linkage analysis using families of Pima Indians showed susceptibility loci for diabetic nephropathy on chromosome 3, 7, and 20. Another linkage analysis using discordant sib‐pairs of Caucasian families with type 1 diabetes identified a critical area on chromosome 3q. However, these results have been inconclusive and further investigation is required.

Recently, a genome‐wide, case‐control analysis identifying susceptibility genes for diabetic nephropathy was performed. As a result, a single nucleotide polymorphism in exon 23 of the solute carrier family 12 (sodium‐chloride cotransporter) member 3 gene was found to be strongly associated with diabetic nephropathy. Although further assessment of this polymorphism is needed, this strategy offers great promise in the identification of genetic factors predisposing patients to diabetic nephropathy. Identification of genetic susceptibility markers may offer new hope in the diagnosis and treatment of diabetic nephropathy.
Genetic susceptibility to type 2 diabetic nephropathy in human and animal models
Authors: GOHDA TOMOHITO , TANIMOTO MITSUO , WATANABE‐YAMADA KAORI , MATSUMOTO MASAKAZU , KANEKO SHIGERU , HAGIWARA SHINJI , SHIINA KENJI , SHIKE TOSHIHIDE , FUNABIKI KAZUHIKO , TOMINO YASUHIKO
Published: September 2005

SUMMARY:  Diabetic nephropathy is the most common cause of end‐stage renal disease (ESRD) in Japan, Western Europe, and the United States. Mega studies such as Diabetes Control and Complication Trial (DCCT), Epidemiology of Diabetes Interventions and Complications (EDIC), and the United Kingdom Prospective Diabetes Study (UKPDS) clarified that poor glycemic and blood pressure control are undoubtedly involved in the development of nephropathy. However, these factors are not sufficient to predict which diabetic patients will develop renal disease, because not all patients with poor glycemic and blood pressure control develop renal disease. Since ethnic variations and familial clustering of diabetic nephropathy have been observed, genetic factors might contribute to susceptibility to this disease. Several methods such as (genome wide) association studies, sib‐pair analysis, and quantitative trait loci (QTLs) analysis are available to examine polygenic diseases. However, no mutations that could explain the majority of nephropathy cases have been identified so far. The development of most diabetic nephropathy might be explained by the polygenic effect (i.e. many minor gene‐gene interactions might be very important in the development of nephropathy). Identification of candidate genes of nephropathy enables targeting of therapy in patients at risk and development of novel therapeutic agents.
Role of megalin, a proximal tubular endocytic receptor, in the pathogenesis of diabetic and metabolic syndrome‐related nephropathies: protein metabolic overload hypothesis
Authors: SAITO AKIHIKO , TAKEDA TETSURO , HAMA HITOMI , OYAMA YUKO , HOSAKA KIYOKO , TANUMA ATSUHITO , KASEDA RYOHEI , UENO MITSUHIRO , NISHI SHINICHI , OGASAWARA SHINYA , GONDAIRA FUMIO , SUZUKI YOSHIKI , GEJYO FUMITAKE
Published: September 2005

SUMMARY:  Megalin is an endocytic receptor on the apical membranes of proximal tubule cells (PTC) in the kidney, and is involved in the reabsorption and metabolism of various proteins that have been filtered by glomeruli. Patients with diabetes, especially type 2 diabetes, or metabolic syndrome are likely to have elevated serum levels of advanced glycation end products, liver‐type fatty acid binding protein, angiotensin II, insulin and leptin, and renal metabolism of these proteins is potentially overloaded. Some of these proteins are themselves nephrotoxic, while others are carriers of nephrotoxic molecules. Megalin is involved in the proximal tubular uptake of these proteins. We hypothesize that megalin‐mediated metabolic overload in PTC leads to compensatory cellular hypertrophy and sustained Na+ reabsorption, causing systemic hypertension and glomerular hyperfiltration via tubuloglomerular feedback, and named this as ‘protein metabolic overload hypothesis’. Impaired metabolism of bioactive proteins such as angiotensin II and insulin in PTC may enhance hypertrophy of PTC and/or Na+ reabsorption. Sleep apnoea syndrome, a frequent complication of diabetes and metabolic syndrome, may cause renal hypoxia and result in relative overload of protein metabolism in the kidneys. The development of strategies to identify patients with diabetes or metabolic syndrome who are at high risk for renal metabolic overload would allow intensive treatment of these patients in an effort to prevent the development of nephropathy. Further studies on the intracellular molecular signalling associated with megalin‐mediated metabolic pathways may lead to the development of novel strategies for the treatment of nephropathies related to diabetes and metabolic syndrome.
Phosphorus availability mediates plasticity in life‐history traits and predator–prey interactions in Daphnia
Authors: Jeyasingh Punidan D. , Weider Lawrence J.
Published: September 2005

We analysed growth plasticity of two Daphnia pulex clones under low‐phosphorus (LP) and high phosphorus (HP) conditions, in the presence of Chaoborus kairomones to examine how food quality (P‐availability) might impact life‐history responses and vulnerability to predation. Overall, clone 1 grew faster, and was larger at maturity. Under HP, both clones responded to kairomones by increasing growth, age and size at maturity, and decreasing fecundity. Under LP, both clones suffered reduced growth, and fecundity. However, the magnitude of response to kairomones depended on a clone by P‐availability interaction. Chaoborus presented a 1 : 1 clonal mixture under HP or LP, consumed more individuals under LP. Moreover, fewer clone 1 individuals were consumed. Studying the effects of P‐availability on life histories, and predator–prey interactions may help us understand the mechanisms generating and maintaining plasticity, as well as influencing genotypic diversity and microevolutionary processes in natural populations.
Rapid evolution and the convergence of ecological and evolutionary time
Authors: Hairston Nelson G. , Ellner Stephen P. , Geber Monica A. , Yoshida Takehito , Fox Jennifer A.
Published: September 2005

Recent studies have documented rates of evolution of ecologically important phenotypes sufficiently fast that they have the potential to impact the outcome of ecological interactions while they are underway. Observations of this type go against accepted wisdom that ecological and evolutionary dynamics occur at very different time scales. While some authors have evaluated the rapidity of a measured evolutionary rate by comparing it to the overall distribution of measured evolutionary rates, we believe that ecologists are mainly interested in rapid evolution because of its potential to impinge on ecological processes. We therefore propose that rapid evolution be defined as a genetic change occurring rapidly enough to have a measurable impact on simultaneous ecological change. Using this definition we propose a framework for decomposing rates of ecological change into components driven by simultaneous evolutionary change and by change in a non‐evolutionary factor (e.g. density dependent population dynamics, abiotic environmental change). Evolution is judged to be rapid in this ecological context if its contribution to ecological change is large relative to the contribution of other factors. We provide a worked example of this approach based on a theoretical predator–prey interaction [Abrams, P. & Matsuda, H. (1997). Evolution, 51, 1740], and find that in this system the impact of prey evolution on predator per capita growth rate is 63% that of internal ecological dynamics. We then propose analytical methods for measuring these contributions in field situations, and apply them to two long‐term data sets for which suitable ecological and evolutionary data exist. For both data sets relatively high rates of evolutionary change have been found when measured as character change in standard deviations per generation (haldanes). For Darwin's finches evolving in response to fluctuating rainfall [Grant, P.R. & Grant, B.R. (2002). Science, 296, 707], we estimate that evolutionary change has been more rapid than ecological change by a factor of 2.2. For a population of freshwater copepods whose life history evolves in response to fluctuating fish predation [Hairston, N.G. Jr & Dillon, T.A. (1990). Evolution, 44, 1796], we find that evolutionary change has been about one quarter the rate of ecological change – less than in the finch example, but nevertheless substantial. These analyses support the view that in order to understand temporal dynamics in ecological processes it is critical to consider the extent to which the attributes of the system under investigation are simultaneously changing as a result of rapid evolution.
Diversity of phage integrases in Enterobacteriaceae: development of markers for environmental analysis of temperate phages
Authors: Balding Claire , Bromley Stephen A. , Pickup Roger W. , Saunders Jon R.
Published: September 2005

Viruses are the most abundant biological entities in aquatic systems. Temperate bacteriophages have enormous influences on microbial diversity, genetic exchange and bacterial population dynamics. However, development of molecular tools for their detection in the environment has been problematic. The integrase gene is used here as a molecular marker to analyse the diversity of temperate bacteriophages in a population of freshwater bacteria. Interrogation of the GenBank database revealed 32 non‐cryptic enteric phage integrase sequences, leading to the development of a suite of 11 degenerate primer sets specific to the extant sequences elucidated. Application of these primer sets to enterobacterial isolates recovered from a freshwater pond and the temperate phages induced from them revealed a number of diverse integrase genes, including novel integrase‐like sequences not represented in the databases. This highlights the potential of utilizing the integrase gene family as a marker for phage diversity.
Exploring the diversity of myxobacteria in a soil niche by myxobacteria‐specific primers and probes
Authors: Wu Zhi‐Hong , Jiang De‐Ming , Li Peng , Li Yue‐Zhong
Published: September 2005

The diversity of myxobacteria in a soil niche was explored using culture‐dependent and ‐independent methods. Conventional cultivation for bacteriolytic myxobacteria produced six types of myxobacteria, which were identified as two Myxococcus spp., two Corallococcus spp., a Cystobacter sp. and a Nannocysts sp. Hybridization analysis of the soil bacterial 16S rRNA gene library with myxobacteria‐specific probes revealed that myxobacteria accounted for less than 1% in the bacterial community. A Cystobacterineae 16S rRNA genes‐rich library was further established from the soil DNA by polymerase chain reaction amplification with a Cystobacterineae‐specific primer combined with a universal bacterial primer. Screening of the special library using Cystobacterineae‐ and Sorangineae‐specific probes produced approximately 45% and 3% positive signals respectively. Sixty‐four positive clones were randomly selected for sequencing. Except three repeats, the sequences were diverse ranging from 0.3% to 21.3%, and homologous with the known myxobacteria at 77.6–99.8%, including 57 in Cystobacterineae, one close to Nannocystis and three much more distant from the known myxobacteria. The sequences in the Cystobacterineae can further be divided into at least 12 groups, of which most were unreported. The results suggest that myxobacteria in nature are much more diverse than were ever known, even in one soil niche.
Distribution, phylogenetic diversity and physiological characteristics of epsilon‐Proteobacteria in a deep‐sea hydrothermal field
Authors: Nakagawa Satoshi , Takai Ken , Inagaki Fumio , Hirayama Hisako , Nunoura Takuro , Horikoshi Koki , Sako Yoshihiko
Published: September 2005

Epsilon‐Proteobacteria is increasingly recognized as an ecologically significant group of bacteria, particularly in deep‐sea hydrothermal environments. In this study, we studied the spatial distribution, diversity and physiological characteristics of the epsilon‐Proteobacteria in various microbial habitats in the vicinity of a deep‐sea hydrothermal vent occurring in the Iheya North field in the Mid‐Okinawa Trough, by using culture‐dependent and ‐independent approaches. The habitats studied were inside and outside hydrothermal plume, and annelid polychaete tubes. In addition, we deployed colonization devices near the vent emission. The polychaete tubes harboured physiologically and phylogenetically diverse microbial community. The in situ samplers were predominantly colonized by epsilon‐Proteobacteria. Energy metabolism of epsilon‐Proteobacteria isolates was highly versatile. Tree topology generated from the metabolic traits was significantly different (P = 0.000) from that of 16S rRNA tree, indicating current 16S rRNA gene‐based analyses do not provide sufficient information to infer the physiological characteristics of epsilon‐Proteobacteria. Nevertheless, culturability of epsilon‐Proteobacteria in various microbial habitats differed among the phylogenetic subgroups. Members of Sulfurimonas were characterized by the robust culturability, and the other phylogenetic subgroups appeared to lose culturability in seawater, probably because of the sensitivity to oxygen. These results provide new insight into the ecophysiological characteristics of the deep‐sea hydrothermal vent epsilon‐Proteobacteria, which has never been assessed by comparative analysis of the 16S rRNA genes.
Archaeal diversity along a soil salinity gradient prone to disturbance
Authors: Walsh David A. , Papke R. Thane , Doolittle W. Ford
Published: September 2005

We employed a cultivation‐independent approach to examine archaeal diversity along a transient soil salinity gradient at Salt Spring in British Columbia, Canada that is routinely eroded due to heavy, recurrent rainfall. Archaeal 16S rRNA gene libraries were created using DNA extracted from three soil samples collected along this gradient. Statistical comparisons indicated similar archaeal richness across sites but, a significant shift in archaeal community composition along the salinity gradient. Seven distinct phylogenetic groups were represented in soil libraries. Haloarchaea were the most commonly sampled group. Other 16S rRNA sequences were related to uncultured Euryarchaeota and Crenarchaeota or halophilic methanogens. Haloarchaeal diversity was remarkably high in soil of elevated salinity compared with previously characterized haloarchaeal communities. Salt Spring haloarchaea were not closely related to known low‐salt adapted/tolerant species, suggesting they may be frequently faced with local mortality as a result of frequent declines in soil salinity. We speculate that ecosystem disturbance – in the form of salinity fluctuations – is one mechanism for maintaining a diverse community of haloarchaea at Salt Spring.
Implementation of national diabetes retinal screening programme is associated with a lower proportion of patients referred to ophthalmology
Authors: Leese G. P. , Morris A. D. , Swaminathan K. , Petrie J. R. , Sinharay R. , Ellingford A. , Taylor A. , Jung R. T. , Newton R. W. , Ellis J. D.
Published: September 2005

Aims  To examine the impact of a new national retinal screening programme on screening attendance, technical quality of images, and referrals to the ophthalmology clinic.

Methods  Results from the previous ad hoc retinal screening service were compared with data from the first year of the new Scottish Diabetes Retinal Screening Programme in Dundee, which was administered according to criteria recommended by the Health Technology Board Scotland.

Results  Of 5150 patients invited for screening, 10.3% of patients did not attend. Overall, 4574 patients underwent single‐field digital retinal photography and 25.4% required mydriasis for an adequate image. After screening, 1.9 and 90.5% were recalled for repeat photography at 6 months and 1 year, respectively, whilst 4.6% were ungradable and 3.0% were referred to the ophthalmology clinic. Compared with the last 18 months of the previous scheme, with the new programme a smaller proportion of patients were referred to ophthalmology (3.0 vs. 5.9%; P < 0.001, difference 2.9%: 95% confidence interval 2.1–3.7%). Moreover, the attendance was higher (89 vs. 82%; P < 0.01) and there were fewer ungradable images (4.6 vs. 7.1%; P < 0.001).

Conclusions  Introduction of a systematic retinal screening programme can reduce the proportion of patients referred to the ophthalmology clinic, and use ophthalmology services more efficiently.
Clustering of protective factors for glucose intolerance and insulin resistance: a cross‐sectional study
Authors: Perry I. J. , Villegas R. , Salim A. , Flynn A.
Published: September 2005

Aims  A cluster of interrelated factors: a body mass index (BMI) < 25 kg/m2, moderate exercise and alcohol intake, non‐smoking and a favourable dietary pattern has been linked with markedly reduced risk of Type 2 diabetes. The aim of this study was to estimate the prevalence of a similar low‐risk group in a sample of middle‐aged Irish men and women, and determine whether this cluster is associated with a reduced risk of glucose intolerance (IFG and Type 2 diabetes according to ADA/WHO criteria) and insulin resistance [homeostasis model assessment (HOMA) score in upper quartile of distribution].

Methods  A cross‐sectional study involving a stratified random sample of 1018 general practice patients, aged 50–69 years. We defined a low‐risk group based on the following variables: BMI < 25 kg/m2; waist–hip ratio < 0.85 for women and 0.90 for men; never smoking status; participation in medium to high level of physical activity; light drinking (3.5–7 units of alcohol per week) and a ‘prudent’ dietary pattern. Valid data were available for glucose tolerance status and HOMA score and all exposure variables from 684 and 671 participants, respectively.

Results  A total of 7.5% of participants had none of the ‘protective factors’, 24.9% had one, 31.0% two, 23.3% three, 10.0% four, 3.0% five and 0.3% had six protective factors. In multivariate analyses the odds ratios for insulin resistance were 0.59, 0.48, 0.14 and 0.04 in persons with one, two, three and four or more low‐risk factors, respectively, relative to those with none. Similar linear inverse trends were observed for glucose intolerance.

Conclusions  The findings are consistent with an inverse linear relation between a cluster of core protective, lifestyle‐related factors and the prevalence of both glucose intolerance and insulin resistance.
Increased field resistance to Tilletia caries provided by a specific antifungal virus gene in genetically engineered wheat
Authors: Schlaich Thomas , Urbaniak Bartosz M. , Malgras Nicole , Ehler Elisabeth , Birrer Christof , Meier Lukas , Sautter Christof
Published: September 2005

The field performance of a viral gene in two Swiss wheat (Triticum aestivum) varieties showed 10% increased fungal resistance against Tilletia caries (stinking smut). To the best of our knowledge, this is the first report of improved resistance against any fungus in the field achieved by genetic engineering in wheat. The genetically modified wheat lines previously showed a c. 30% decrease in symptoms of T. caries in the glasshouse (Clausen, M., Kräuter, R., Schachermayr, G., Potrykus, I. and Sautter, C. (2000) Antifungal activity of a virally encoded gene in transgenic wheat. Nat. Biotechnol. 18, 446–449), depending on the fungal strain inoculated. A glasshouse experiment run in parallel to the field test, and using the same collection of T. caries, gave the same results. In a dose–response experiment with isolated fungal strains, in which the infection pressure was varied via the spore concentration, the transgene behaved as a quantitative resistance gene and shifted the S‐shaped dose–response curve towards higher resistance. The transgene was shown to be highly specific for fungi of the order Ustilaginales. Tests of the transgene using cell cultures of eukaryotes, including hamster and human, showed no significant side‐effects with respect to biosafety. Endogenous pathogen‐related genes were also activated on fungal infection in the presence of the kp4 transgene.
ALTARPIECES AND AGENCY: THE ALTARPIECE OF THE SOCIETY OF THE PURIFICATION AND ITS ‘INVISIBLE SKEIN OF RELATIONS’
Authors: O'Malley Michelle
Published: September 2005

To consider the Renaissance altarpiece as an active social force, this article draws on ideas concerning the efficacy of works of art articulated by Alfred Gell in his compelling book Art and Agency (1998). Considering as a case study the altarpiece depicting the Virgin enthroned with saints and angels, commissioned by the Florentine Confraternity of the Purification in 1461 and painted by Benozzo Gozzoli, the text investigates the network of relationships that generated the work, including the confraternity's association with the Virgin, the Medici family, the convent of the Observant Dominicans, the citizens of Florence and the painters Fra Angelico and Benozzo Gozzoli. The essay argues that Renaissance altarpieces played a dynamic and practical role in the social life of the period. Moreover, it contends that altarpieces themselves were causal in the creation of works of art, and links this analysis to the problem of interpreting altarpieces that were made to be pictorially similar to an already existing work.

Michelle O'Malley is the Director of the Office for Research Support in the School of Humanities at the University of Sussex; previously she was the Head of Education for Exhibitions at the Royal Academy of Arts, London. Her published work includes The Business of Art: Contracts and the Commissioning Process in Renaissance Italy (Yale University Press, forthcoming 2005) and The Material Renaissance, co‐edited with Evelyn Welch (Manchester University Press, forthcoming 2007). She is currently working on issues of valuing and pricing, focusing on the career of Pietro Perugino. Her interest in questions of agency is related to this topic.
Contextual Factors Affect Absent Reference Comprehension in 14‐Month‐Olds
Authors: Ganea Patricia A.
Published: September 2005

How do infants come to understand references to absent objects? 14‐month‐old infants first learned a name for a novel toy, which was then placed out of view. The infants who listened to a story mentioning the nonvisible object, looked, pointed, and searched for it more often than did infants who heard a story using a different name. Their behavior was affected by minor changes in context; they responded to the name of the out‐of‐view toy less often when it was not easily accessible or after a delay. These findings indicate that the development of absence reference comprehension depends on the interaction of representational and contextual factors.
Conditions for Young Infants' Perception of Object Trajectories
Authors: Bremner J. Gavin , Johnson Scott P. , Slater Alan , Mason Uschi , Foster Kirsty , Cheshire Andrea , Spring Joanne
Published: September 2005

When an object moves behind an occluder and re‐emerges, 4‐month‐old infants perceive trajectory continuity only when the occluder is narrow, raising the question of whether time or distance out of sight is the important constraining variable. One hundred and forty 4‐month‐olds were tested in five experiments aimed to disambiguate time and distance out of sight. Manipulating the object's visible speed had no effect on infants' responses, but reducing occlusion time by increasing object speed while occluded induced perception of trajectory continuity. In contrast, slowing the ball while it was behind a narrow or intermediate screen did not modify performance. It is concluded that 4‐month‐olds perceive trajectory continuity when time or distance out of sight is short.
Trajectories of Peer Victimization and Perceptions of the Self and Schoolmates: Precursors to Internalizing and Externalizing Problems
Authors: Troop‐Gordon Wendy , Ladd Gary W.
Published: September 2005

Evidence indicates that peer victimization is predictive of later maladjustment, but the mechanisms by which harassment impairs development have yet to be identified. The objectives of this study were (a) to discern normative trends in peer victimization experiences and self‐ and peer perceptions during preadolescence and (b) to investigate associations between individual differences in these trajectories and changes in psychosocial adjustment. A sample of 381 children (196 girls; 185 boys) was followed longitudinally between the ages of 9 and 11 years. Latent growth curve analyses revealed that, although children's self‐appraisals became increasingly positive during preadolescence, their appraisals of peers became more negative. Moreover, analyses supported the contention that self‐ and peer beliefs act as mechanisms through which victimization is related to psychological dysfunction.