bluuebunny/crossref_metadata_2025 huggingface dataset:
Exploring differences in response to treatment with peginterferon alpha 2a (40kD) and ribavirin in chronic hepatitis C between genotypes 2 and 3
Authors: Powis J. , Peltekian K. M. , Lee S. S. , Sherman M. , Bain V. G. , Cooper C. , Krajden M. , Deschenes M. , Balshaw R. F. , Heathcote E. Jenny , Yoshida E. M. ,   for the Canadian Pegasys Study Group
Published: September 2007

Summary.  Chronic hepatitis C virus (HCV) infections with genotype 2 or 3 are associated with favourable sustained virologic response (SVR) rates. However, genotype 3 may respond less well. We reassessed all treatment‐naive patients with genotype 2 and 3 participating in a large expanded‐access, non‐randomized, open‐label trial, evaluating 180μg pegylated interferon (peg‐IFN) alpha‐2a (40kD) once weekly and 800 mg/day ribavirin for 24–48 weeks. Factors measured prior to initiation of antiviral therapy were considered in the multiple logistic regression model for predicting SVR. In total, 180 patients were analysed of which 72 (40%) were infected by genotype 2 and 108 (60%) genotype 3. The baseline characteristics between patients infected by genotype 2 or 3 were no different including the distribution of hepatic fibrosis stages by METAVIR score. Overall SVR was lower in those patients infected with genotype 3. The significant multivariate predictors of lack of SVR were hepatic fibrosis (P = 0.014) and genotype 3 (P = 0.030). The negative impact of cirrhosis (METAVIR score F4) on treatment response was more evident among subjects with genotype 3 than those with genotype 2 (P = 0.027). There is significant interaction between cirrhosis and genotype 3 leading to a poor antiviral response in such patients requiring an alternate management strategy. This finding should be confirmed in a larger population.
Waning‐off effect of serum hepatitis B surface antibody amongst Taiwanese university students: 18 years post‐implementation of Taiwan’s national hepatitis B vaccination programme
Authors: Su F.‐H. , Chen J.‐D. , Cheng S.‐H. , Sung K.‐Y. , Jeng J.‐J. , Chu F.‐Y.
Published: September 2007

Summary.  Hepatitis B virus (HBV) infection and its sequelae remain a major health problem for Taiwan. The national hepatitis B (HB) vaccination programme was first launched in 1984 to combat the spread of this infection. This study examined the status of HBV infection amongst students at a Taiwanese university in 2005, 18 years after the implementation of a nation‐wide mass HB vaccination programme. In 2005, 5875 new university entrants, who were born during the period 1 July 1976 to 30 June 1988, were subdivided into one of 12 one‐year‐interval birth‐year cohorts. Each student was individually tested for serum hepatitis B surface antigen (HBsAg), Antibody to hepatitis B surface antigen (anti‐HBs) and antibody to hepatitis B core antigen (anti‐HBc) status. We observed a declining trend of past exposure to HB infection from 48.7% (1976 birth‐year cohort) to 5.2% (1987 birth‐year cohort). The prevalence of chronic HB infection also declined from 14.5% (1976 birth‐year cohort) to 1.9% (1987 birth‐year cohort). The prevalence of persistent HB immunity through (earlier) active vaccination declined from 72% (1984 birth‐year cohort) to 41.6% (1987 birth‐year cohort). The prevalence of HB infection‐naïve individuals increased from 18.2% (1984 birth‐year cohort) to 53.1% (1987 birth‐year cohort). This study demonstrates that as the implementation of the mass HB vaccination programme in 1984, the incidence of HB infection in Taiwan has declined, although a ‘waning‐off’ effect of serum anti‐HBs to low or undetectable levels, which may not provide protection, amongst this student population has arisen, 18 years following the implementation of the nation‐wide HB vaccination programme. Such a situation may mean that these individuals may not be effectively protected against future HB infection. A booster dose of HB vaccine, given 18 years following HB vaccination, perhaps even earlier, should be considered.
Assessment of hepatitis C virus‐RNA clearance under combination therapy for hepatitis C virus genotype 1: performance of the transcription‐mediated amplification assay
Authors: Ferraro D. , Giglio M. , Bonura C. , Di Marco V. , Mondelli M. U. , Craxì A. , Di Stefano R.
Published: September 2007

Summary. Monitoring of HCV‐RNA in blood during antiviral therapy is performed mostly by commercially available reverse transcription polymerase chain reaction‐based (RT‐PCR) assays, with a lower detection limit of 30–50 IU/mL of HCV‐RNA. Use of different tests in the pivotal trials of combination therapy has generated some discordance, in terms of predictive value of the early virological response (EVR). To evaluate whether the use of a more sensitive test, as a qualitative assay based on transcription mediated amplification (TMA) with a lower detection limit of 5–10 IU/mL of HCV‐RNA, may obtain a better prediction of EVR and of the ultimate virological outcome, we retrospectively evaluated serial samples from 108 naïve patients with HCV genotype 1 chronic hepatitis, treated with pegylated α2b interferon plus ribavirin for 48 weeks and with a 24 weeks stopping rule. Serum samples of patients, obtained during treatment at weeks 4, 12, 24 and 48 and after treatment at week 24, were evaluated by TMA. Comparison of the RT‐PCR and TMA assays for the qualitative detection of HCV‐RNA showed no significant differences in performance when these tests were used at the end of the treatment period for assessing patients without an on‐treatment virological response and those who eventually obtain a sustained virological response. Our results show instead that the use of TMA assay to detect HCV‐RNA at 12 and 24 weeks of the combination therapy is more effective than RT‐PCR in identifying patients with the highest probability of sustained HCV‐RNA clearance.
Inferior response of Asian vs non‐Asian hepatitis C genotype 3 infection to combination antiviral therapy
Authors: Freshwater D. A. , O’Donnell K. , Mutimer D. J.
Published: September 2007

Summary.  Racial differences in response to treatment of hepatitis C virus (HCV) have been noted in several trials. In this study, we compared the response rate to treatment of Asian patients infected by genotype 3 HCV with non‐Asians treated for the same genotype. Sixteen of 38 (42.1%) Asians achieved a sustained virological response (SVR), compared with 41 of 66 (62.1%) Caucasians (P = 0.063). At baseline prior to treatment, Asians had a higher histological fibrosis stage (P = 0.0014), indicating more advanced disease at presentation. In univariable analysis of baseline factors predicting failure to achieve an SVR, Asian ethnicity, fibrosis stage, higher serum aspartate transaminase, bilirubin and alkaline phosphatase, as well as lower white cell count, haemoglobin and platelet count were statistically significant. None of these factors achieved significance in multivariate analysis, possibly because of the relatively small number of patients studied. We have observed an inferior response to treatment of Asian vs Caucasian patients. The poor response probably reflects the more advanced liver disease at baseline observed for Asian British patients.
Genetic drift vs. natural selection in a long‐term small isolated population: major histocompatibility complex class II variation in the Gulf of California endemic porpoise (Phocoena sinus)
Authors: MUNGUIA‐VEGA ADRIAN , ESQUER‐GARRIGOS YARELI , ROJAS‐BRACHO LORENZO , VAZQUEZ‐JUAREZ RICARDO , CASTRO‐PRIETO AINES , FLORES‐RAMIREZ SERGIO
Published: September 2007

Although many studies confirm long‐term small isolated populations (e.g. island endemics) commonly sustain low neutral genetic variation as a result of genetic drift, it is less clear how selection on adaptive or detrimental genes interplay with random forces. We investigated sequence variation at two major histocompatibility complex (Mhc) class II loci on a porpoise endemic to the upper Gulf of California, México (Phocoena sinus, or vaquita). Its unique declining population is estimated around 500 individuals. Single‐strand conformation polymorphism analysis revealed one putative functional allele fixed at the locus DQB (n = 25). At the DRB locus, we found two presumed functional alleles (n = 29), differing by a single nonsynonymous nucleotide substitution that could increase the stability at the dimer interface of αβ‐heterodimers on heterozygous individuals. Identical trans‐specific DQB1 and DRB1 alleles were identified between P. sinus and its closest relative, the Burmeister's porpoise (Phocoena spinipinnis). Comparison with studies on four island endemic mammals suggests fixation of one allele, due to genetic drift, commonly occurs at the DQA or DQB loci (effectively neutral). Similarly, deleterious alleles of small effect are also effectively neutral and can become fixed; a high frequency of anatomical malformations on vaquita gave empirical support to this prediction. In contrast, retention of low but functional polymorphism at the DRB locus was consistent with higher selection intensity. These observations indicated natural selection could maintain (and likely also purge) some crucial alleles even in the face of strong and prolonged genetic drift and inbreeding, suggesting long‐term small populations should display low inbreeding depression. Low levels of Mhc variation warn about a high susceptibility to novel pathogens and diseases in vaquita.
Across the great divide: genetic forensics reveals misidentification of endangered cutthroat trout populations
Authors: METCALF JESSICA L. , PRITCHARD VICTORIA L. , SILVESTRI SARAH M. , JENKINS JAZZMIN B. , WOOD JOHN S. , COWLEY DAVID E. , EVANS R. PAUL , SHIOZAWA DENNIS K. , MARTIN ANDREW P.
Published: September 2007

Accurate assessment of species identity is fundamental for conservation biology. Using molecular markers from the mitochondrial and nuclear genomes, we discovered that many putatively native populations of greenback cutthroat trout (Oncorhynchus clarkii stomias) comprised another subspecies of cutthroat trout, Colorado River cutthroat trout (Oncorhynchus clarkii pleuriticus). The error can be explained by the introduction of Colorado River cutthroat trout throughout the native range of greenback cutthroat trout in the late 19th and early 20th centuries by fish stocking activities. Our results suggest greenback cutthroat trout within its native range is at a higher risk of extinction than ever before despite conservation activities spanning more than two decades.
Assimilation of NAD+ precursors in Candida glabrata
Authors: Ma Biao , Pan Shih‐Jung , Zupancic Margaret L. , Cormack Brendan P.
Published: September 2007

The yeast pathogen Candida glabrata is a nicotinamide adenine dinucleotide (NAD+) auxotroph and its growth depends on the environmental supply of vitamin precursors of NAD+. C. glabrata salvage pathways defined in this article allow NAD+ to be synthesized from three compounds – nicotinic acid (NA), nicotinamide (NAM) and nicotinamide riboside (NR). NA is salvaged through a functional Preiss–Handler pathway. NAM is first converted to NA by nicotinamidase and then salvaged by the Preiss–Handler pathway. Salvage of NR in C. glabrata occurs via two routes. The first, in which NR is phosphorylated by the NR kinase Nrk1, is independent of the Preiss–Handler pathway. The second is a novel pathway in which NR is degraded by the nucleosidases Pnp1 and Urh1, with a minor role for Meu1, and ultimately converted to NAD+ via the nicotinamidase Pnc1 and the Preiss–Handler pathway. Using C. glabrata mutants whose growth depends exclusively on the external NA or NR supply, we also show that C. glabrata utilizes NR and to a lesser extent NA as NAD+ sources during disseminated infection.
Alterations in local chromatin environment are involved in silencing and activation of subtelomeric var genes in Plasmodium falciparum
Authors: Voss Till S. , Tonkin Christopher J. , Marty Allison J. , Thompson Jennifer K. , Healer Julie , Crabb Brendan S. , Cowman Alan F.
Published: September 2007

Plasmodium falciparum erythrocyte membrane protein 1 (PfEMP1), encoded by the var gene family, undergoes antigenic variation and plays an important role in chronic infection and severe malaria. Only a single var gene is transcribed per parasite, and epigenetic control mechanisms are fundamental in this strategy of mutually exclusive transcription. We show that subtelomeric upsB var gene promoters carried on episomes are silenced by default, and that promoter activation is sufficient to silence all other family members. However, they are active by default when placed downstream of a second active var promoter, underscoring the significance of local chromatin environment and nuclear compartmentalization in var promoter regulation. Native chromatin covering the SPE2‐repeat array in upsB promoters is resistant to nuclease digestion, and insertion of these regulatory elements into a heterologous promoter causes local alterations in nucleosomal organization and promoter repression. Our findings suggest a common logic underlying the transcriptional control of all var genes, and have important implications for our understanding of the epigenetic processes involved in the regulation of this major virulence gene family.
Substrate induction of siderophore transport in Bacillus subtilis mediated by a novel one‐component regulator
Authors: Gaballa Ahmed , Helmann John D.
Published: September 2007

When iron is scarce, Bacillus subtilis expresses genes involved in the synthesis and uptake of the siderophore bacillibactin (BB) and uptake systems to pirate other microbial siderophores. Here, we demonstrate that transcriptional induction of the feuABCybbA operon, encoding the Fe–BB uptake system, is mediated by Btr (formerly YbbB), which is encoded by the immediately upstream gene. Btr contains an AraC‐type DNA binding domain fused to a substrate binding protein (SBP) domain related to FeuA, the SBP for Fe–BB uptake. When cells are iron‐limited, the Fur‐mediated repression of btr is relieved and Btr binds to a conserved direct repeat sequence adjacent to feuA to activate transcription. If BB is present, Btr further activates feuA expression. Btr binds with high affinity to both apo–BB and Fe–BB, and the resulting complex displays a significantly increased efficacy as a transcriptional activator relative to Btr alone. Btr can also activate transcription in response to the structurally similar siderophore enterobactin, although genetic analyses indicate that the two siderophores make distinct interactions with the Btr substrate binding domain. Thus, the FeuABC transporter is optimally expressed under conditions of iron starvation, when Fur‐mediated repression is relieved, and in the presence of its cognate substrate.
Evidence for woodlice‐specialization in Dysdera spiders: behavioural versus developmental approaches
Authors: ŘEZÁČ MILAN , PEKÁR STANO
Published: September 2007

Abstract The dietary specialization in a woodlouse‐eating spider Dysdera hungarica Kulczyñski (Araneae: Dysderidae) is studied using two types of laboratory experiments. In the first experiment, the rate of development of spiderlings reared on one of three diets: pure woodlice [composed of two species Oniscus asellus Linnaeus and Armadillidium vulgare (Latreille)]; pure flies (Drosophila melanogaster Meigen); and a mixed woodlouse‐fly diet, is studied. Spiders develop significantly faster on the woodlice‐containing diets (i.e. pure woodlice and mixed diet) than on the fly diet. In the second experiment, the prey‐choice for two woodlice species (O. asellus and A. vulgare) and a fly (D. melanogaster) is investigated. Dysdera hungarica spiders capture significantly more often flies than woodlice. These contrasting results reveal the different value of developmental and behavioural experiments. The dietary studies are assumed to provide better evidence of specialization than behavioural experiments, which might be misleading due to unnatural conditions. It is concluded that D. hungarica is a metabolically adapted woodlice specialist. The present study thus provides the first evidence of nutritional specialization on woodlice.
Size‐dependent energy reserves, energy utilization and longevity in the yellow dung fly
Authors: BLANCKENHORN WOLF U. , FANTI JEANNETTE , REIM CONSTANZE
Published: September 2007

Abstract Teneral reserve components (soluble sugars, glycogen, lipids), as well as proteins, of laboratory‐reared yellow dung flies (Scathophaga stercoraria) are shown to increase hypo‐allometrically (slope < 1) with body size. This is also true for sugars and glycogen of field‐caught reproductive flies, the lipid content of which however, increases hyper‐allometrically (slope > 1), probably related to foraging or reproductive activity. The longevity, or starvation resistance, of adults subsisting exclusively on their teneral reserves equally increases with body size, and this positive relationship remains when flies have access to sugar, pollen or prey for 24 h after emergence. Energy use, by contrast, is generally not body size dependent, except for lipid (and possibly glycogen) utilization when flies were completely starved. All the results obtained are independent of sex after controlling for sexual size dimorphism. These net results clearly support the greater energy efficiency of larger flies (Kleiber’s law), whereas only weak evidence is obtained in support of the contrasting hypothesis of greater absolute energy demands of larger individuals, possibly because such effects are likely masked by stronger size‐dependent anabolic effects.
Discrepancy in laboratory and field attraction of apple fruit moth Argyresthia conjugella to host plant volatiles
Authors: KNUDSEN GEIR K. , BENGTSSON MARIE , KOBRO SVERRE , JAASTAD GUNNHILD , HOFSVANG TROND , WITZGALL PETER
Published: September 2007

Abstract Apple fruit moth Argyresthia conjugella is a specialist seed predator of rowan Sorbus aucuparia. Large‐scale synchronous fluctuation of seed production in rowan (i.e. named masting) drives the apple fruit moth to seek alternative host plants such as apple, during years when rowan berries are not available for oviposition. The role of plant volatile compounds in the attraction of gravid apple fruit moth females is studied in a laboratory wind tunnel. Volatiles from rowan branches with green berries stimulate female moths to fly upwind and to land at the odour source. By contrast, females are not attracted to rowan branches without green berries, and they are not attracted to apple, demonstrating that the chemical stimulus from rowan berries is required for attraction. Attraction to synthetic compounds identified from rowan, anethole and 2‐phenyl ethanol confirms the role of plant volatiles in host finding. These two compounds, however, show a discrepant behavioural effect in wind tunnel and field tests. Field traps baited with 2‐phenyl ethanol capture female moths but anethole does not produce significant captures. Wind tunnel tests produce the opposite results: moths fly upwind towards the anethole lure, whereas 2‐phenyl ethanol is not attractive at all. Wind tunnel attraction to 2‐phenyl ethanol is achieved by adding odour from a rowan branch without berries, which is not attractive on its own. This finding demonstrates that interaction with the background odour contributes to the behavioural effect of plant volatile stimuli in the field.
Developmentally regulated membrane glycoproteins sharing antigenicity with rhamnogalacturonan II are not detected in nodulated boron deficient Pisum sativum
Authors: REDONDO‐NIETO MIGUEL , PULIDO LUIS , REGUERA MARÍA , BONILLA ILDEFONSO , BOLAÑOS LUIS
Published: September 2007

The peribacteroid membrane (PBM) of symbiosomes from pea root nodules developed in the presence of boron (+B) was labelled by anti‐rhamnogalacturonan II (RGII) (anti‐rhamnogalacturonan II pectin polysaccharide) antiserum. However, in nodules from plants grown at low boron (−B), anti‐RGII pectin polysaccharide did not stain PBMs. Given that RGII pectin binds to borate, and that symbiosomes differentiate aberrantly in −B nodules because of abnormal vesicle traffic, anti‐RGII pectin polysaccharide antigens were further analysed. Following electrophoresis and electroblotting, anti‐RGII pectin polysaccharide immunostained three bands in +B but not in −B nodule‐derived PBMs. A similar banding pattern was observed after the immunostaining of membrane fractions from uninfected roots, indicating that anti‐RGII pectin polysaccharide antigens are common to both peribacteroid and plasma membranes. Protease treatment of samples led to disappearance of anti‐RGII pectin polysaccharide labelling, indicating that the three immunostained bands correspond to proteins or glycoproteins. The immunochemical study of RGII antigen distribution during nodule development showed that it is strongly present on the PBM of dividing (undifferentiated) symbiosomes but progressively disappeared during symbiosome maturation. In B‐deficient nodules, PBMs were never decorated with RGII antigens, and there was an abnormal targeting of vesicles containing pectic polysaccharide (homogalacturanan) to cell membranes. Overall, these results indicate that RGII, boron and certain membrane (glyco)‐proteins may interact closely and function cooperatively in membrane processes associated with symbiosome division and general cell growth.
Molecular phenotyping of lignin‐modified tobacco reveals associated changes in cell‐wall metabolism, primary metabolism, stress metabolism and photorespiration
Authors: Dauwe Rebecca , Morreel Kris , Goeminne Geert , Gielen Birgit , Rohde Antje , Van Beeumen Jos , Ralph John , Boudet Alain‐Michel , Kopka Joachim , Rochange Soizic F. , Halpin Claire , Messens Eric , Boerjan Wout
Published: September 2007

Lignin is an important component of secondarily thickened cell walls. Cinnamoyl CoA reductase (CCR) and cinnamyl alcohol dehydrogenase (CAD) are two key enzymes that catalyse the penultimate and last steps in the biosynthesis of the monolignols. Downregulation of CCR in tobacco (Nicotiana tabacum) has been shown to reduce lignin content, whereas lignin in tobacco downregulated for CAD incorporates more aldehydes. We show that altering the expression of either or both genes in tobacco has far‐reaching consequences on the transcriptome and metabolome. cDNA‐amplified fragment length polymorphism‐based transcript profiling, combined with HPLC and GC–MS‐based metabolite profiling, revealed differential transcripts and metabolites within monolignol biosynthesis, as well as a substantial network of interactions between monolignol and other metabolic pathways. In general, in all transgenic lines, the phenylpropanoid biosynthetic pathway was downregulated, whereas starch mobilization was upregulated. CCR‐downregulated lines were characterized by changes at the level of detoxification and carbohydrate metabolism, whereas the molecular phenotype of CAD‐downregulated tobacco was enriched in transcript of light‐ and cell‐wall‐related genes. In addition, the transcript and metabolite data suggested photo‐oxidative stress and increased photorespiration, mainly in the CCR‐downregulated lines. These predicted effects on the photosynthetic apparatus were subsequently confirmed physiologically by fluorescence and gas‐exchange measurements. Our data provide a molecular picture of a plant’s response to altered monolignol biosynthesis.
Feasibility and cost–benefit of implementing pooled screening for HCVAg in small blood bank settings
Authors: Sarov B. , Novack L. , Beer N. , Safi J. , Soliman H. , Pliskin J. S. , Litvak E. , Yaari A. , Shinar E.
Published: September 2007

summary To examine the accuracy, feasibility and benefits of screening for hepatitis C virus core antigen (HCVAg) using enzyme‐linked immunosorbent assay (ELISA) test in pools. Many countries cannot afford to test blood donations for hepatitis C using molecular methods. Screening individual units using the ELISA HCVAg test is an acceptable, yet still expensive, alternative, especially for small blood bank settings. This study evaluated the option of screening for HCVAg in pools. The sensitivity (Se) and specificity (Sp) of HCVAg in pools of three and six antibody‐negative samples were estimated and compared with polymerase chain reaction (PCR). The feasibility and cost–benefit of the assay was assessed on 960 routine samples collected at a hospital blood bank in Gaza.

Based on results for 50 PCR‐positive pools and 50 and 110 PCR‐negative pools of three and six, the Se of testing in pools of three and six samples is 80–82% [95% confidence interval (CI): 66·3–91·4] and Sp ≥98% (95% CI: 89·4–100·0) compared with PCR. The incidence of antigen in donors in Gaza was 0·1% (95% CI: 0–0·56). Cost analyses suggested significant benefits from implementing screening blood donations for HCVAg when the incidence rate is >4·2/10 000, leading to reduction in the expenditures needed to treat patients infected with HCV.

The risk of transfusion‐transmitted hepatitis C in resource‐deprived developing countries can be efficiently reduced by additional screening of antibody‐negative blood donations for HCVAg in pools of six.
Comparing after‐ripening response and germination requirements of Conyza canadensis and C. bonariensis (Asteraceae) through logistic functions
Authors: KARLSSON L M , MILBERG P
Published: September 2007

Germination requirements and after‐ripening effects during one year of dry storage at 15/5 and 25/15°C (day/night) were compared for Conyza bonariensis and C. canadensis (Asteraceae). A logistic function was fitted to the results from tests over time in various incubation conditions, using three populations of each species as replicates. Time required for response to dry storage was measured by using a new method, the third derivative of the logistic function. Therefore, a point when major germination was achieved could be detected, without having to rely on maximum germination (which is uncertain), individual data points or any subjectively chosen limit. Fresh seeds of both species were dependent on light for germination and after‐ripening was mainly manifested by increasing germination in darkness. Low dormancy status and light requirement might indicate that soil cultivations should rapidly reduce the seedbanks of these species, although fecundity and wind dispersal will affect population levels. The species differed in their germination response, with C. bonariensis germinating at lower temperatures than C. canadensis. This seemingly counter‐intuitive result may explain the prevention of fatal germination of C. canadensis in cold conditions and its behaviour as a summer annual in northern climates, while C. bonariensis is restricted to warmer parts of the world.
Tumbleweeds in the Western Australian cropping system: seed dispersal characteristics of Salsola australis
Authors: BORGER C P D , WALSH M , SCOTT J K , POWLES S B
Published: September 2007

Salsola australis, like other agricultural weed species of the Salsola genus, produces a mobile seedbank. Aspects of this mobile seedbank were investigated in three field trials, including total seed production, rate of seed shedding, rate at which seeds lose germinability and the distance and directionality of plant movement. Total seed production was highly variable (ranging from 138 to 7734 seeds per plant), but was directly related to aboveground plant biomass at maturity. Following senescence, mature plants broke free of their root system and the wind driven plants moved considerable distances (1.6–1247.2 m). Half of the mobile plants moved <100 m, as they became entangled with other S. australis plants within the stand. Seed shedding commenced before the plants became mobile and increased with movement, but was also related to the aging and weathering processes experienced by stationary or mobile plants. All plants retained a proportion of their seed in spite of movement, weathering and ageing of the plants, although germinability of retained seed dropped to <2% after 2 months. Salsola australis engages in broad scale seed dispersal similar to that observed in other species of the Salsola genus, allowing this species to maintain a high rate of invasion and range expansion.
A review of non‐chemical weed control on hard surfaces
Authors: RASK A M , KRISTOFFERSEN P
Published: September 2007

Weed control research to date has mainly focused on arable land, especially regarding herbicides, but also regarding non‐chemical methods. Some of these experiences can be applied to hard surface areas. However, weeds on hard surface areas cause problems that are different from those on arable land. Additionally, crop tolerance does not need to be considered when choosing an appropriate weed control method on these areas. The aim of this review is to describe current knowledge of weeds and weed control methods on hard surface areas and reveal potential ways of advancement. One of the shortcomings of non‐chemical weed control on hard surfaces thus far, is a lack of proper definition of efficiency of the weed control methods. To obtain effective control, more frequently repeated treatments are required than chemical weed management, thereby increasing the costs of labour and fuel. One way to reduce costs can be by adjusting the level of control to the required visual street quality. Weeds are adapted to the hard surface environment and may be less susceptible to certain control methods. This review indicates that for efficient weed control on hard surfaces there is a need for combining weed control techniques, applying sensors for detecting weeds, adapting the energy dose to type of weed flora and prevention of weeds by improved construction of new surfaces.
Are weed patches stable in location? Application of an explicitly two‐dimensional methodology
Authors: HEIJTING S , VAN DER WERF W , STEIN A , KROPFF M J
Published: September 2007

Field observations were made in three years continuous maize cultivation in the Netherlands to study the spatial pattern and stability of spatial pattern over time in agricultural weeds. Two‐dimensional correlograms were made, using data from single years, to characterise spatial correlation and pattern, while data from two different years were used to calculate correlation over space and time, to characterise the stability of pattern. Weeds that were able to attain high recruitment also exhibited the strongest spatial correlations. These weeds were Echinochloa crus‐galli, Chenopodium album, Chenopodium polyspermum and Solanum nigrum. Weeds that were less successful in attaining high densities in the maize rotation, also showed less spatial correlation. Wind dispersing Compositae, e.g. Taraxacum officinale, had spatially uncorrelated patterns. All weeds that showed spatial correlation also showed stability in space, except E. crus‐galli. The latter species showed marked population increase and the locations and extent of its patches changed over the years. Statistical interpretation of the data is discussed, as are potential consequences for site‐specific management and optimal sampling of weeds.
Challenges for herbicide resistance evolution and management: 50 years after Harper
Authors: NEVE P
Published: September 2007

Evolved resistance to herbicides is a classic example of ‘evolution in action’. This paper calls for a greater integration of ‘evolutionary‐thinking’ into herbicide resistance research. This integration, it is argued, should lead weed scientists to become less focused on simply describing resistance and more driven towards a deeper understanding of the evolutionary forces that underpin resistance evolution. I have attempted in this short paper to initiate a debate into how this might be done. In the first instance, I have highlighted the widespread misunderstanding and mis‐measurement by weed scientists of fitness and fitness costs. I have also speculated on the potential for herbicide rotations to exacerbate resistance problems by selecting for generalist (metabolic) resistance. Finally, I have discussed in greater detail the contribution of herbicide rates to resistance evolution and have reported work conducted in Australia which has shown the potential for low herbicide doses to rapidly select for very high levels of resistance in Lolium rigidum. The controversial hypotheses and suggestions put forward need to be tested by field experimentation. They may prove to be unfounded or incorrect, but if they cause us to question and expand the current resistance paradigm they will have been useful.
Effects of three management strategies on the seedbank, emergence and the need for hand weeding in an organic arable cropping system
Authors: RIEMENS M M , GROENEVELD R M W , LOTZ L A P , KROPFF M J
Published: September 2007

The effects of three different weed management strategies on the required input of hand weeding in an arable organic farming system, the weed seedbank in the soil and the emerging weed seedling emergence were studied from 1996 to 2003. Strategies were based on population dynamic models and aimed for (1) control of weeds as carried out in standard organic farming practice, (2) control of all residual weeds that grow above the crop and (3) prevention of all weed seed return to the soil. Under all strategies, the size of the seedbank increased during the conversion from conventional to organic farming systems. The increase under strategy 3 was significantly smaller than the increase under the other strategies. From 1999 onwards, the weed densities in plots treated with strategy 3 became significantly lower than the weed densities in plots treated with the other strategies. The time needed for hand‐weeding required to prevent weed seed return, in addition to the time needed in standard organic farming practices, reduced during the course of the study. A management strategy aimed at the prevention of seed return (strategy 3) can reduce the size of the increase of the seedbank, which is usually observed after transition from conventional to organic farming. This study provides unique real‐world data that are essential for evaluating population dynamic models. The results may contribute to the development of weed management systems based on ‘no seed’ threshold strategies and to a further decrease in the dependence on herbicides.
Molecular and biochemical mechanisms of defence induced in pea by Rhizobium leguminosarum against Orobanche crenata
Authors: MABROUK Y , SIMIER P , DELAVAULT P , DELGRANGE S , SIFI B , ZOURGUI L , BELHADJ O
Published: September 2007

Orobanche species (broomrapes) are parasitic weeds which dramatically decrease the yields of many economically important dicotyledonous crops, including pea (Pisum sativum), in Mediterranean areas. Previously, we identified some Rhizobium leguminosarum strains, including P.SOM, which could both promote pea development and significantly reduce infection by Orobanche crenata, notably through induction of necrosis of attached parasites. In the present study, induced resistance against broomrape in the nodulated pea was shown to be associated with significant changes in rates of oxidative lipoxygenase (Lox) and phenylpropanoid/isoflavonoid pathways and in accumulation of derived toxins, including phenolics and pisatin (pea phytoalexin). Changes were followed for 5 weeks after inoculation and attack by Orobanche. In contrast to non‐inoculated plants or Orobanche only infected plants, polyphenoloxidase (PPO) activity and hydrogen peroxide content increased in response to bacteria inoculation indicating the involvement of oxidative processes. In parallel, the nodulated roots displayed high Lox activity related to the overexpression of the lox1 gene. Similarly, the expression of phenylalanine ammonia lyase (PAL) and 6a‐hydroxymaackiain 3‐O‐methyltransferase (Hmm6a) genes were induced early during nodule development, suggesting the central role of the phenylpropanoid/isoflavonoid pathways in the elicited defence. As a consequence, the derived products, phenolics and pisatin, accumulated in response to rhizobacteria and conferred mechanical and chemical barriers to the invading parasite. These results highlight the likely role of signalling pathways in induced resistance and suggest these mechanisms should be enhanced through integrated Orobanche management practices.
Are pre‐spraying growing conditions a major determinant of herbicide efficacy?
Authors: RIETHMULLER‐HAAGE I , BASTIAANS L , KEMPENAAR C , SMUTNY V , KROPFF MJ
Published: September 2007

To evaluate the effect of pre‐spraying growing conditions on herbicide efficacy, two years of experimentation were conducted in which Persicaria maculosa plants were exposed to different light intensities for 1–4 days before metribuzin treatment. Specific leaf area, rather than plant growth rate or plant size, was the only parameter that correlated well with herbicide efficacy in both years of experimentation. The negative relationship between the ED50 and the specific leaf area indicates that leaf characteristics might be an important determinant of herbicide efficacy, for instance through an effect on herbicide uptake. In the third year of experimentation this hypothesis was further investigated by raising six cohorts of weed plants at a 1‐week interval and thus exposing them to a range of weather conditions. Clear relationships between uptake and herbicide efficacy were found for a combination of four plant species (Solanum nigrum, Senecio vulgaris, Chenopodium album and Brassica napus) and two herbicides (phenmedipham and bentazone). For phenmedipham, uptake was negatively correlated with global radiation and positively correlated with relative humidity. For the herbicide bentazone the opposite was found. These results were not species‐specific. This study shows the importance of the sensitivity of herbicide × species combinations and indicates that pre‐spraying weather information is relevant for the development of reduced dose rate recommendations.
Suppression of Digitaria sanguinalis and Amaranthus palmeri using autumn‐sown glucosinolate‐producing cover crops in organically grown bell pepper
Authors: NORSWORTHY J K , MALIK M S , JHA P , RILEY M B
Published: September 2007

Experiments were conducted to compare growth characteristics, biomass production and glucosinolate content of seven autumn‐planted glucosinolate‐producing cover crops that were terminated the following spring. The control of Digitaria sanguinalis and Amaranthus palmeri following cover crop incorporation into soil was characterised and fruit yields of bell pepper transplanted into cover crop‐amended soil were determined. Differences in glucosinolate concentration and composition were noted between cover crop roots and shoots and among cover crops. Total biomass production by cover crops ranged from 103 g m−2 for garden cress to 894 g m−2 for Indian mustard (F‐E75), but cover crop biomass was not correlated with D. sanguinalis and A. palmeri control. D. sanguinalis and A. palmeri control in bell pepper varied by cover crop. D. sanguinalis control by cover crops ranged from 38% to 79%, and A. palmeri control was 23% to 48% at 4 weeks after transplanting (WATP) bell pepper in 2004. D. sanguinalis control was positively correlated with total glucosinolate production, but A. palmeri control was not. D. sanguinalis control in 2005 ranged from 0% to 38% at 2 WATP. In the absence of weeds, cover crops did not negatively affect fruit yields which were often higher than in the absence of a cover crop. Glucosinolate‐producing cover crops are not a stand‐alone weed management strategy, but some will provide early season control of D. sanguinalis and A. palmeri without having a negative effect on transplanted bell pepper.
‘Balance’ is in the eye of the beholder: providing information to support informed choices in antenatal screening via Antenatal Screening Web Resource
Authors: Ahmed Shenaz , Bryant Louise , Hewison Jenny
Published: September 2007

Objectives  The Antenatal Screening Web Resource (AnSWeR) was designed to support informed prenatal testing choices by providing balanced information about disability, based on the testimonies of disabled people and their families. We were commissioned by the developers to independently evaluate the website. This paper focused on how participants evaluated AnSWeR in terms of providing balanced information.

Setting  West Yorkshire.

Participants  A total of 69 people were drawn from three groups: health professionals, people with personal experience of tested‐for conditions (Down’s syndrome, cystic fibrosis and spina bifida) and people representing potential users of the resource.

Method  Data were collected via focus groups and electronic questionnaires.

Results  Participants believed that information about the experience of living with the tested‐for conditions and terminating a pregnancy for the conditions were important to support informed antenatal testing and termination decisions. However, there were differences in opinion about whether the information about the tested‐for conditions was balanced or not. Some people felt that the inclusion of photographs of people with the tested‐for conditions introduced biases (both positive and negative). Many participants were also of the opinion that AnSWeR presented insufficient information on termination of an affected pregnancy to support informed choice.

Conclusion  This study highlighted the difficulty of designing ‘balanced’ information about tested‐for conditions and a lack of methodology for doing so. It is suggested that AnSWeR currently provides a counterbalance to other websites that focus on the medical aspects of disability. Its aim to provide ‘balanced’ information would be aided by increasing the number and range of case studies available on the website.
The UCLan community engagement and service user support (Comensus) project: valuing authenticity, making space for emergence
Authors: Downe Soo , McKeown Mick , Johnson Eileen ,   Comensus Community Involvement Team,   Comensus Advisory Group, Koloczek Lidia , Grunwald Angela , Malihi‐Shoja Lisa
Published: September 2007

Objective  To develop and evaluate service user, carer and community involvement in health and social care education.

Background  Despite the high policy profile of involvement issues, there appear to be no published accounts of schemes that have used a systematic whole‐faculty approach to community engagement in health and social care higher education.

Focus of this paper  The set up and early development of a faculty‐wide community engagement project.

Setting and participants  Staff from the faculty of health in one University, local service users and carers and community group project workers and local National Health Service (NHS) and public sector staff.

Design  Participatory action research including document review, field notes, questionnaires and interviews.

Analysis  Thematic analysis. The emerging themes were tested by seeking disconfirming data, and through verification with stake‐holders.

Results  Prior to the study, there were examples of community engagement in the participating faculty, but they occurred in specific departments, and scored low on the ‘ladder of involvement’. Some previous attempts at engagement were perceived to have failed, resulting in resistance from staff and the community. Despite this, an advisory group was successfully formed, and project framing and development evolved with all stake‐holders over the subsequent year. The four themes identified in this phase were: building accessibility; being ‘proper’ service users/carers;moving from suspicion to trust: mutually respectful partnerships as a basis for sustainable change; and responses to challenge and emergence.

Conclusions  Successful and sustainable engagement requires authenticity. Many problems and solutions arising from authentic engagement are emergent, and potentially challenging to organizations.
The impact of array genomic hybridization on mental retardation research: a review of current technologies and their clinical utility
Authors: Zahir F , Friedman JM
Published: September 2007

Our understanding of the causes of mental retardation is benefiting greatly from whole‐genome scans to detect submicroscopic pathogenic copy number variants (CNVs) that are undetectable by conventional cytogenetic analysis. The current method of choice for performing whole‐genome scans for CNVs is array genomic hybridization (AGH). Several platforms are available for AGH, each with its own strengths and limitations. This review discusses considerations that are relevant to the clinical use of whole‐genome AGH platforms for the diagnosis of pathogenic CNVs in children with mental retardation. Whole‐genome AGH studies are a maturing technology, but their high diagnostic utility assures their increasing use in clinical genetics.
Non‐random maternal X‐chromosome inactivation associated with PHACES
Authors: Levin JH , Kaler SG
Published: September 2007

The acronym PHACES is used to describe the association of posterior fossa malformations, hemangiomas, arterial anomalies (cardiovascular or cerebrovascular), coarctation of the aorta and cardiac defects, eye abnormalities, and sternal or ventral defects. We report a female patient with an uncommon variant of this neurocutaneous disorder who manifested a sternal cleft; supraumbilical raphe; hemangiomas of the face, chest, and extremities; micrognathia and cerebrovascular anomalies. A literature review of PHACES patients with both sternal cleft and supraumbilical raphe showed a marked female predilection. Taken together with cases of sternal cleft, supraumbilical raphe and facial hemangiomas tabulated by Gorlin et al. (1994), 91% (40/44) of patients are female. One affected male died shortly after birth. We hypothesized that the gender bias in PHACES results from mutation in an X‐linked dominant gene often lethal in males, and performed X‐inactivation analysis of the polymorphic androgen receptor locus in this family. We documented consistently skewed X‐inactivation (80%/20% in two independent analyses) in the unaffected mother and consistently random X‐inactivation (47:53 and 61:39 in independent analyses) in the proband. These findings are consistent with favorably skewed X‐inactivation producing a normal maternal phenotype, a phenomenon documented in X‐linked dominant Rett syndrome.
Screening for BRCA1 and BRCA2 mutations in Eastern Finnish breast/ovarian cancer families
Authors: Hartikainen JM , Kataja V , Pirskanen M , Arffman A , Ristonmaa U , Vahteristo P , Ryynänen M , Heinonen S , Kosma V‐M , Mannermaa A
Published: September 2007

Familial aggregation is thought to account for 5–10% of all breast cancer cases, and high penetrance breast and ovarian cancer susceptibility genes BRCA1 and BRCA2 explain ≤20% of these. Hundreds of mutations among breast/ovarian cancer families have been found in these two genes. The mutation spectrum and prevalence, however, varies widely among populations. Thirty‐six breast/ovarian cancer families were identified from a population sample of breast and ovarian cancer cases among a relatively isolated population in Eastern Finland, and the frequency of BRCA1/BRCA2 germline mutations were screened using heteroduplex analysis, protein truncation test and sequencing. Five different mutations were detected in seven families (19.4%). Two mutations were found in BRCA1 and three in BRCA2. One of the mutations (BRCA2 4088insA) has not been detected elsewhere in Finland while the other four, 4216‐2nt A→G and 5370 C→T in BRCA1 and 999del5 and 6503delTT in BRCA2, are recurrent Finnish founder mutations. These results add to the evidence of the geographical differences in distribution of Finnish BRCA1/BRCA2 mutations. This screen also provides further evidence for the presumption that the majority of Finnish BRCA1/BRCA2 founder mutations have been found and that the proportion of BRCA1/BRCA2 mutations in Finnish breast/ovarian cancer families is around 20%.