bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of benthivorous fish on biogeochemical processes in lake sediments
Authors: PERSSON ANDERS , SVENSSON JONAS M.
Published: June 2006

1. Studies of aquatic environments have shown that community organisation may strongly affect ecosystem functioning. One common phenomenon is a change in nutrient level following a shift in the fish community composition. Although several hypotheses have been suggested, there is no consensus on which mechanisms are involved. Our study evaluated indirect effects of benthivorous fish on the biogeochemical processes at the sediment–water interface separately from direct effects caused by nutrient excretion or sediment resuspension.

2. We assigned field enclosures to three treatments representing typical pond communities; without fish, addition of approximately 10 small tench or addition of one large bream. After one summer, we monitored the water chemistry, benthic invertebrates and periphyton in the enclosures and sampled sediment cores for laboratory analysis of biochemical process rates (oxygen, phosphorus and nitrogen exchange between sediment and water, and denitrification rate).

3. Fish had strong negative effects on benthic invertebrates, but weaker effects on periphyton, organic content and porosity of the sediment. Moreover, there were significant positive fish effects on both phosphorus and nitrogen concentrations in the water. However, there were no general treatment effects on sediment processes that could explain the treatment effects on water chemistry in the enclosures.

4. Hence, overall treatment effects attenuated along the chain of interactions. We conclude that the observed effect of benthic fish on water chemistry was probably because of direct effects on nutrient excretion or resuspension of sediment. The similarity between bream and tench treatments suggests large niche complementarity despite their different habitat preferences.
CO2 uptake patterns depend on water current velocity and shoot morphology in submerged stream macrophytes
Authors: NIELSEN HANNE DALSGAARD , NIELSEN SØREN LAURENTIUS , MADSEN TOM VINDBÆK
Published: June 2006

1. The influence of current velocity on the pattern of photosynthetic CO2 uptake in three species of submerged stream macrophytes was described by analysing the grain density in autoradiographs of leaves exposed to 14CO2.

2. In Elodea canadensis, the CO2 uptake was approximately two‐fold higher near the leaf periphery compared with the midrib section at high current velocity, whereas at low current velocity the area of relatively high CO2 uptake expanded from the leaf periphery towards the midrib and basal sections of the leaves.

3. In Potamogeton crispus and Callitriche stagnalis the CO2 uptake was uniform throughout the leaves at low current velocity, whereas at high current velocity the CO2 uptake appeared to increase randomly in some areas of the leaves.

4. The relationship between the photosynthetic CO2 uptake pattern and the dynamics of flow surrounding submerged shoots at low and high current velocity is discussed in relation to shoot morphology. In E. canadensis, thick diffusive boundary layers may develop between leaves because of screening effects at high current velocity. Increased diffusion path for CO2 may contribute to inhibitory effects on photosynthesis in this species.
Transient inhibition of Th1‐type cytokine production by CD4+ T cells in hepatitis B core antigen immunized mice is mediated by regulatory T cells
Authors: Chichester Jessica A. , Feitelson Mark A. , Calkins Catherine E.
Published: June 2006

The non‐cytopathic hepatitis B virus (HBV) can induce chronic infections characterized by weak and limited T cell responses against the virus. The factors contributing to the failure to clear HBV and subsequent development of chronic HBV infections are not clearly understood, but a strong interferon‐gamma (IFN‐γ) response by CD4+ T cells against the nucleocapsid hepatitis B core antigen (HBcAg) of the virus appears to be important for viral clearance. The present study documents depressed numbers of CD4+ T cells secreting IFN‐γ and interleukin‐2 (IL‐2) in enzyme‐linked immunospot assay (ELISPOT) assays restimulated for 24 hr with antigen following both primary and secondary immunizations of mice with recombinant hepatitis B core antigen (rHBcAg). The kinetics of these responses showed that the depression occurred following a peak response and lasted approximately 2 weeks before returning to the previous peak levels. The depression was abrogated by depletion of CD25+ cells prior to culture in the ELISPOT assay, suggesting inhibition by regulatory T cells. This inhibition of IFN‐γ and IL‐2 production was also reversed by in vitro restimulation of the test cells for 48 hr rather than 24 hr in the assay. No such transient, reversible inhibition was detected in the production of IL‐5, a Th2‐type cytokine. The inhibition in cytokine production did not appear to correlate with the number of antibody‐secreting cells or the isotypes produced. This delay by regulatory T cells of Th1‐type cytokine production could contribute to viral persistence in chronic HBV infection by interfering with the critical role IFN‐γ plays in protection against viral infections.
Control of the innate epithelial antimicrobial response is cell‐type specific and dependent on relevant microenvironmental stimuli
Authors: Schauber Jürgen , Dorschner Robert A. , Yamasaki Kenshi , Brouha Brook , Gallo Richard L.
Published: June 2006

Immune defence against microbes depends in part on the production of antimicrobial peptides, a process that occurs in a variety of cell types but is incompletely understood. In this study, the mechanisms responsible for the induction of cathelicidin and β‐defensin antimicrobial peptides were found to be independent and specific to the cell type and stimulus. Vitamin D3 induced cathelicidin expression in keratinocytes and monocytes but not in colonic epithelial cells. Conversely, butyrate induced cathelicidin in colonic epithelia but not in keratinocytes or monocytes. Distinct factors induced β‐defensin expression. In all cell types, vitamin D3 activated the cathelicidin promoter and was dependent on a functional vitamin D responsive element. However, in colonic epithelia butyrate induced cathelicidin expression without increasing promoter activity and vitamin D3 activated the cathelicidin promoter without a subsequent increase in transcript accumulation. Induction of cathelicidin transcript correlated with increased processed mature peptide and enhanced antimicrobial activity against Staphylococcus aureus. However, induction of β‐defensin‐2 expression did not alter the innate antimicrobial capacity of cells in culture. These data suggest that antimicrobial peptide expression is regulated in a tissue‐specific manner at transcriptional, post‐transcriptional and post‐translational levels. Furthermore, these data show for the first time that innate antimicrobial activity can be triggered independently of the release of other pro‐inflammatory molecules, and suggest strategies for augmenting innate immune defence without increasing inflammation.
Interleukin‐4 supports interleukin‐12‐induced proliferation and interferon‐γ secretion in human activated lymphoblasts and T helper type 1 cells
Authors: Kriegel Martin A. , Tretter Theresa , Blank Norbert , Schiller Martin , Gabler Christoph , Winkler Silke , Kalden Joachim R. , Lorenz Hanns‐Martin
Published: June 2006

Interleukin‐12 (IL‐12) and IL‐4 are known to differentially promote T helper (Th) cell differentiation. While IL‐12 induces interferon‐γ (IFN‐γ) production and maturation of Th1 cells, IL‐4 is thought to antagonize IL‐12 and to favour Th2 development. Here we studied the combined action of various concentrations of common γ‐chain (γc‐chain) cytokines, including IL‐4 and the Th1 cytokine IL‐12, in human activated lymphoblasts and Th1 cells. IL‐4 and IL‐7 potentiated IL‐12‐induced proliferation at every concentration tested (1–10 ng/ml) without increasing rescue from apoptosis, indicating that proliferation was directly affected by these cytokine combinations. With regards to cytokine secretion, IL‐2 together with IL‐12 initiated tumour necrosis factor‐α synthesis, enhanced IFN‐γ production, and shedding of soluble IL‐2 receptor α as expected. Importantly, combining IL‐4 with IL‐12 also enhanced IFN‐γ secretion in lymphoblasts and a Th1 cell line. Investigating signal transduction in lymphoblasts induced by these cytokines, we found that not only IL‐2 but also IL‐4 enhances signal transducer and activator of transcription 3 (STAT3) tyrosine phosphorylation by IL‐12. Tyrosine phosphorylations of janus kinase 2 (JAK‐2), tyrosine kinase 2 (TYK2), extracellular signal‐regulated kinase (ERK) and STAT4, STAT5 and STAT6 were not potentiated by combinations of these cytokines, suggesting specificity for increased STAT3 phosphorylation. In conclusion, two otherwise antagonizing cytokines co‐operate in activated human lymphoblasts and Th1 cells, possibly via STAT3 as a converging signal. These data demonstrate that IL‐4 can directly enhance human Th1 cell function independently of its known actions on antigen‐presenting cells. These findings should be of importance for the design of cytokine‐targeted therapies of human Th‐cell‐driven diseases.
Use of factor analysis in Journal of Advanced Nursing: literature review
Authors: Watson Roger , Thompson David R.
Published: June 2006

Aim.  This paper reports a review analysing the use of factor analysis in papers in Journal of Advanced Nursing.

Background.  Factor analysis is a multivariate statistical method for reducing large numbers of variables to fewer underlying dimensions. There are several methods of factor analysis with principal components analysis being the most commonly applied. Factor analysis has been used by researchers in nursing for many years but the standards for use and reporting are variable.

Method.  Papers using factor analysis in Journal of Advanced Nursing were retrieved from 1982 to the end of 2004. The search term ‘factor analysis’ was used in the CINAHL database and applied specifically to Journal of Advanced Nursing in December 2004. Retrieved papers were included in the review if they came from Journal of Advanced Nursing and used factor analysis as part of the method of the reported study.

Results.  One hundred and twenty‐four papers were retrieved as a result of the initial search criteria of which 116 were from Journal of Advanced Nursing. Screening of papers for the use of factor analysis left 100 papers for review. Principal components analysis was the most commonly used method of factor analysis; Eigenvalues greater than one was the most commonly applied criterion for selecting the number of factors followed by orthogonal rotation to achieve simple structure. The majority of papers did not report the whole factor solution and there were papers that did not specify anything beyond the fact that they carried out factor analysis. Confirmatory factor analysis was rarely used and exploratory methods other than principal components analysis were also rarely used.

Conclusions.  Factor analysis is quite commonly used in nursing research reported in Journal of Advanced Nursing. While some papers are exemplary there is room for improvement in the reporting of all aspects of factor analysis.
The determinants of species richness of a relatively young coral‐reef ichthyofauna
Authors: Kiflawi Moshe , Belmaker Jonathan , Brokovich Eran , Einbinder Shai , Holzman Roi
Published: June 2006

Aim  Unique topographic features left the Red Sea and its north‐eastern extension into the Gulf of Aqaba practically devoid of coral‐reef‐based organisms during the last glacial maximum. The current ichthyofauna in these two ‘regions’ thus represents the product of relatively recent colonization by species found in the Arabian Sea, which adjoins the Red Sea at its southern tip. We used this system to test why some marine species seemingly fail to extend their geographic range, thereby generating spatial heterogeneity in biodiversity.

Location  The Arabian Sea, Red Sea, and the Gulf of Aqaba.

Methods  A list of coral‐reef‐associated fish species, belonging to the 10 most speciose families, was compiled for each region using published sources. The data were analysed (major axis regression, randomization tests) for taxonomic and body‐size‐dependent biases in colonization probabilities. A simple probabilistic model was used to examine the potential contribution of local (within‐region) extinctions to determining species composition in the Red Sea.

Results  Of the 462 reef‐associated species that inhabit the Arabian Sea, 69% have crossed successfully into the Red Sea; of these, 55% have crossed into the Gulf of Aqaba. A species’ probability of being found in either ‘target’ was independent of presumed innate differences, i.e. ecological correlates of taxonomic affiliation and body size. Similarly, local extinctions were found unlikely to have been of consequence over the past several thousand years.

Main conclusions  Present‐day differences in the species richness of reef‐associated fish species among the Arabian Sea, Red Sea and Gulf of Aqaba appear to be the product of external, non‐selective constraints on colonization. The random nature of the colonization process is suggestive of ecological redundancy among coral‐reef fish species. Importantly, the study places a time frame on the processes that determine spatial patterns of biodiversity in reef fish.
Adjuvant effect of mushroom glucan and bovine lactoferrin upon Aeromonas hydrophila vaccination in catla, Catla catla (Hamilton)
Authors: Kamilya D , Maiti T K , Joardar S N , Mal B C
Published: June 2006

Mushroom glucan and bovine lactoferrin (Lf), known for their immunostimulatory potential, were used as adjuvant in conjunction with a formalin‐killed Aeromonas hydrophila vaccine in catla, Catla catla. In vitro antigen‐specific responsiveness of catla leucocytes and protective responses against experimental challenge with homologous antigen were monitored following immunization. Antigen‐specific proliferation, ‘macrophage activating factor’ (MAF) production and antibody production were significantly higher in fish injected with glucan adjuvanted vaccine. Lf adjuvanted preparations showed a weak proliferative response and MAF production, although the antibody production was significantly higher than the controls. A good degree of protection was achieved with the glucan adjuvanted vaccine. However, in spite of producing significant anti‐A. hydrophila antibody, Lf adjuvanted vaccine did not confer any protection following challenge with A. hydrophila. The potential of adjuvanticity of mushroom glucan and bovine Lf in intraperitoneal vaccination is discussed.
First description of non‐motile Yersinia ruckeri serovar I strains causing disease in rainbow trout, Oncorhynchus mykiss (Walbaum), cultured in Spain
Authors: Fouz B , Zarza C , Amaro C
Published: June 2006

Yersinia ruckeri, the causal agent of enteric redmouth (ERM) disease, was isolated from epizootics that occurred in different Spanish rainbow trout, Oncorhynchus mykiss (Walbaum), farms in which vaccination against ERM had been performed. In all episodes, the most pronounced clinical signs exhibited by affected fish were severe haemorrhages in the mouth, eyes and around the vent. The isolates were identified as Y. ruckeri serovar I by 16S rRNA sequencing together with serological tests. They lacked motility and lipase activity and thus belonged to biotype 2, and were highly virulent for juvenile rainbow trout, both by intraperitoneal injection (from 3.1 × 102 to 6.3 × 103 cfu per fish) and bath challenge (5.1–7.3 × 106 cfu mL−1). This is the first description of Y. ruckeri serovar I biotype 2 causing disease in cultured trout in Spain vaccinated with commercial ERM vaccines. The occurrence of this emergent pathogen in Spanish continental aquaculture from its first isolation in 2001 to date is also documented.
Pituitary mRNA Expression of the Growth Hormone Axis in the 1‐Year‐Old Intrauterine Growth Restricted Rat
Authors: Prins T. , Fodor M. , Delemarre‐van de Waal H. A.
Published: June 2006

Intrauterine growth restriction (IUGR) is one of the major causes of short stature in childhood. Abnormalities in the growth hormone (GH) axis have frequently been observed in children who are born intrauterine growth restricted and GH treatment is effective to improve final height. However, the way that the GH axis is involved is not fully understood. Previously, when investigating the effect of IUGR on the central somatotrophic axis, a hypothalamic effect was discovered with elevated somatostatin and decreased neuropeptide Y mRNA expression levels, whereas serum GH and insulin‐like growth factor I (IGFI) were unaltered. These findings were thought to indicate a hypothalamic alteration of the GH axis due to IUGR, probably to compensate pituitary output, thereby normalising peripheral values of GH and IGFI. Therefore, the present study aimed to evaluate the effect of IUGR on the pituitary GH axis in this rat model. Pups from rats that underwent bilateral uterine artery ligation at day 17 of pregnancy were studied. Pituitary glands were collected from 1‐year‐old offspring for quantitative measurements of GH, GH‐receptor (GH‐R), GH‐releasing hormone receptor (GHRH‐R), somatostatin receptor subtype 2 and 5, IGFI and IGFI receptor mRNA levels using a real‐time reverse transcriptase‐polymerase chain reaction. In addition, liver GH‐R and IGFI mRNA expression levels were measured and a radioimmunoassay was performed to determine serum IGFI levels. In the IUGR rat, levels of pituitary GH, GH‐R and GHRH‐R relative gene expression (RGE) were increased. No differences were found in the RGE level of all other pituitary growth factors, liver GH‐R and IGFI, and serum IGFI concentration between IUGR and control rats. The present data show that intrauterine growth failure leads to changes in the pituitary that might counterbalance the effects found previously in the hypothalamus.
Influence of abutment height on strain in a mandibular overdenture
Authors: DONG J. , IKEBE K. , GONDA T. , NOKUBI T.
Published: June 2006

summary  The purpose of this study was to investigate the influence of coping heights on the strain around the abutment teeth and at the middle part of mandibular overdentures, using strain gauges. A mandibular edentulous model with a silicone artificial mucosa of thickness 2 mm was made. Two artificial roots were embedded on both sides in the canine position. The coping had a dome‐shaped upper surface at a height of 0, 2, 4 and 6 mm. On the lingual polished surface of the overdenture, three strain gauges were attached in the left canine position at the vertical level corresponding to the top of the 6, 4 and 2 mm copings and two strain gauges were attached in the middle section (upper and lower). A vertical loading of 49 N was applied on the occlusal surface of first premolar, first molar and second molar. When loading on the first premolar adjacent to an abutment, the largest tensile strain was observed on the overdenture surface close to the top of each coping, independent of coping heights. When loading on the first premolar on the opposite side, the tensile strains around the coping were remarkably smaller. In the middle part of the overdenture, the compressive strains became larger by reducing the coping height or loading on distal point. The largest tensile strain was observed on the overdenture surface close to the top of copings, independent of coping heights.
How much genetic variation is stored in the seed bank? A study of Atriplex tatarica (Chenopodiaceae)
Authors: MANDÁK B. , BÍMOVÁ K. , MAHELKA V. , PLAČKOVÁ I.
Published: June 2006

We investigated to what extent the soil seed bank differed genetically and spatially in comparison to three consecutive life history stages (seedlings, mature plants, and fruiting plants) in a natural population of Atriplex tatarica. Representatives of particular life history stages from twenty subunits within a large population were randomly collected and subjected to allozyme analysis. Comparison of population polymorphism among various life history stages showed significant differences in observed heterozygosity (HO) and F statistics (FIS and FST), but nonsignificant ones in the cases of number of alleles per polymorphic locus (A) and gene diversity (HS). These results indicate an increasing number of heterozygotes, a decreasing level of inbreeding and an increase of the partitioning genetic diversity among populations with increasing population age. Spatial autocorrelation was used to calculate f, the average co‐ancestry coefficient between individuals within distance intervals of two meters along a 39 m long transect. Significant positive fine scale genetic structure was detected in mature and fruiting plants but not in soil seeds and seedlings stages. The results of the presented study on A. tatarica indicated that significant differences exist in genetic differentiation, differentiation in allele frequencies and spatial autocorrelation among early (soil seeds and seedlings) and late (mature and fruiting plants) life history stages but not within early and late ones. This pattern suggests that, rather than storing genetic variability in the soil or germination and establishment success, self‐thinning might be the major microselective force in populations of A. tatarica.
Genetic structure in northeastern populations of the Alpine newt (Triturus alpestris): evidence for post‐Pleistocene differentiation
Authors: PABIJAN M. , BABIK W.
Published: June 2006

Genetic variation in 13 populations of the Alpine newt, Triturus alpestris, was assessed at the northeastern margin of its range (southern Poland). Variation at six microsatellite loci was scored in 354 newts, and two mitochondrial DNA fragments (c. 2000 bp) were sequenced in a subset of 27 individuals. Significant differences in allele frequencies and the presence of private alleles determined genetic units corresponding to three separate mountain ranges, i.e. the Carpathian, Sudetes and Holy Cross Mountains. FST's were three times greater in among than in within mountain range pairwise comparisons. An assignment test and pairwise FST's suggested relatively high levels of gene flow at the local level, although the Sudetes populations revealed some subtle structuring. Genetic variation was lower in the Carpathians and Holy Cross Mountains. The geographic pattern of mitochondrial DNA variation indicated that these newt populations originated from a single glacial refugium/founder population, and that the colonization of southern Poland took place in an easterly direction. The data show that substantial neutral variation and between group divergence has accumulated relatively quickly in these low‐vagility organisms. The Alpine newt case exemplifies species history as a factor determining patterns of genetic diversity in marginal populations.
Intramuscular interstitial cells of Cajal associated with mast cells survive nitrergic nerves in achalasia
Authors: Zarate N. , Wang X. Y. , Tougas G. , Anvari M. , Birch D. , Mearin F. , Malagelada J.‐r. , Huizinga J. D.
Published: June 2006

Abstract  Achalasia is dominated by injury to inhibitory nerves. As intramuscular interstitial cells of Cajal (ICC‐IM) are proposed to form functional units with nitrergic nerves, their fate in achalasia may be critically important. We studied the relationship between loss of nitrergic nerves and injury to ICC‐IM in patients with achalasia and determined associations between ICC‐IM and mast cells (MC), using quantitative immunohistochemistry and electron microscopy. Loss of neuronal nitric oxide synthase (nNOS) immunoreactivity was completed within 3 years of acquiring achalasia. Thereafter, progressive ultrastructural injury to remaining nerve structures was evident. Within the first 2 years, the number of ICC‐IM did not decline although ultrastructural injury was already present. Thereafter, loss of ICC‐IM occurred unrelated to duration of disease. Damage to ICC‐IM appeared unrelated to nerve injury. A significant MC infiltration was observed in the musculature; the number of MC was positively related to the persistent number of ICC‐IM. Mast cell formed close contacts with ICC‐IM and piecemeal‐degranulation occurred towards ICC‐IM. In conclusion, injury to ICC‐IM in achalasia is variable, but not related to duration of disease and injury to nitrergic nerves. MC are prominent and form close functional contact with ICC‐IM which may be responsible for their relatively long survival.
Conifer defence against insects: microarray gene expression profiling of Sitka spruce (Picea sitchensis) induced by mechanical wounding or feeding by spruce budworms (Choristoneura occidentalis) or white pine weevils (Pissodes strobi ) reveals large‐scale changes of the host transcriptome
Authors: RALPH STEVEN G. , YUEH HESTHER , FRIEDMANN MICHAEL , AESCHLIMAN DANA , ZEZNIK JEFFREY A. , NELSON COLLEEN C. , BUTTERFIELD YARON S. N. , KIRKPATRICK ROBERT , LIU JERRY , JONES STEVEN J. M. , MARRA MARCO A. , DOUGLAS CARL J. , RITLAND KERMIT , BOHLMANN JÖRG
Published: June 2006

Conifers are resistant to attack from a large number of potential herbivores or pathogens. Previous molecular and biochemical characterization of selected conifer defence systems support a model of multigenic, constitutive and induced defences that act on invading insects via physical, chemical, biochemical or ecological (multitrophic) mechanisms. However, the genomic foundation of the complex defence and resistance mechanisms of conifers is largely unknown. As part of a genomics strategy to characterize inducible defences and possible resistance mechanisms of conifers against insect herbivory, we developed a cDNA microarray building upon a new spruce (Picea spp.) expressed sequence tag resource. This first‐generation spruce cDNA microarray contains 9720 cDNA elements representing c. 5500 unique genes. We used this array to monitor gene expression in Sitka spruce (Picea sitchensis) bark in response to herbivory by white pine weevils (Pissodes strobi, Curculionidae) or wounding, and in young shoot tips in response to western spruce budworm (Choristoneura occidentalis, Lepidopterae) feeding. Weevils are stem‐boring insects that feed on phloem, while budworms are foliage feeding larvae that consume needles and young shoot tips. Both insect species and wounding treatment caused substantial changes of the host plant transcriptome detected in each case by differential gene expression of several thousand array elements at 1 or 2 d after the onset of treatment. Overall, there was considerable overlap among differentially expressed gene sets from these three stress treatments. Functional classification of the induced transcripts revealed genes with roles in general plant defence, octadecanoid and ethylene signalling, transport, secondary metabolism, and transcriptional regulation. Several genes involved in primary metabolic processes such as photosynthesis were down‐regulated upon insect feeding or wounding, fitting with the concept of dynamic resource allocation in plant defence. Refined expression analysis using gene‐specific primers and real‐time PCR for selected transcripts was in agreement with microarray results for most genes tested. This study provides the first large‐scale survey of insect‐induced defence transcripts in a gymnosperm and provides a platform for functional investigation of plant–insect interactions in spruce. Induction of spruce genes of octadecanoid and ethylene signalling, terpenoid biosynthesis, and phenolic secondary metabolism are discussed in more detail.
Phytochromes A1 and B1 have distinct functions in the photoperiodic control of flowering in the obligate long‐day plant Nicotiana sylvestris
Authors: ZHENG ZHI‐LIANG , YANG ZHENBIAO , JANG JYAN‐CHYUN , METZGER JAMES D.
Published: June 2006

The obligate long‐day plant Nicotiana sylvestris with a nominal critical day length of 12 h was used to dissect the roles of two major phytochromes (phyA1 and phyB1) in the photoperiodic control of flowering using transgenic plants under‐expressing PHYA1 (SUA2), over‐expressing PHYB1 (SOB36), or cosuppressing the PHYB1 gene (SCB35). When tungsten filament lamps were used to extend an 8 h main photoperiod, SCB35 and SOB36 flowered earlier and later, respectively, than wild‐type plants, while flowering was greatly delayed in SUA2. These results are consistent with those obtained with other long‐day plants in that phyB has a negative role in the control of flowering, while phyA is required for sensing day‐length extensions. However, evidence was obtained for a positive role for PHYB1 in the control of flowering. Firstly, transgenic plants under‐expressing both PHYA1 and PHYB1 exhibited extreme insensitivity to day‐length extensions. Secondly, flowering in SCB35 was completely repressed under 8 h extensions with far‐red‐deficient light from fluorescent lamps. This indicates that the dual requirement for both far‐red and red for maximum floral induction is mediated by an interaction between phyA1 and phyB1. In addition, a diurnal periodicity to the sensitivity of both negative and positive light signals was observed. This is consistent with existing models in which photoperiodic time measurement is not based on the actual measurement of the duration of either the light or dark period, but rather the coincidence of endogenous rhythms of sensitivity – both positive and negative – and the presence of light cues.
MRI of long‐distance water transport: a comparison of the phloem and xylem flow characteristics and dynamics in poplar, castor bean, tomato and tobacco
Authors: WINDT CAREL W. , VERGELDT FRANK J. , DE JAGER P. ADRIE , VAN AS HENK
Published: June 2006

We used dedicated magnetic resonance imaging (MRI) equipment and methods to study phloem and xylem transport in large potted plants. Quantitative flow profiles were obtained on a per‐pixel basis, giving parameter maps of velocity, flow‐conducting area and volume flow (flux). The diurnal xylem and phloem flow dynamics in poplar, castor bean, tomato and tobacco were compared. In poplar, clear diurnal differences in phloem flow profile were found, but phloem flux remained constant. In tomato, only small diurnal differences in flow profile were observed. In castor bean and tobacco, phloem flow remained unchanged. In all plants, xylem flow profiles showed large diurnal variation. Decreases in xylem flux were accompanied by a decrease in velocity and flow‐conducting area. The diurnal changes in flow‐conducting area of phloem and xylem could not be explained by pressure‐dependent elastic changes in conduit diameter. The phloem to xylem flux ratio reflects what fraction of xylem water is used for phloem transport (Münch’s counterflow). This ratio was large at night for poplar (0.19), castor bean (0.37) and tobacco (0.55), but low in tomato (0.04). The differences in phloem flow velocity between the four species, as well as within a diurnal cycle, were remarkably small (0.25–0.40 mm s−1). We hypothesize that upper and lower bounds for phloem flow velocity may exist: when phloem flow velocity is too high, parietal organelles may be stripped away from sieve tube walls; when sap flow is too slow or is highly variable, phloem‐borne signalling could become unpredictable.
Inoculum prevalence, host infection and biological control of Colletotrichum acutatum: causal agent of blueberry anthracnose in British Columbia
Authors: Verma N. , MacDonald L. , Punja Z. K.
Published: June 2006

To identify the causal organism of anthracnose (ripe‐rot), which reduces yield and postharvest quality of blueberries grown in British Columbia, Canada, 80 isolates were recovered from diseased fruits collected from commercial blueberry fields during 2002–04 and identified as Colletotrichum acutatum using colony morphology, growth rate and species‐specific PCR primers. In vitro incubation of replicated sets of inoculated detached berries at various temperatures produced infection at temperatures of 7–30°C, with an optimum at 20°C. Colletotrichum acutatum could not survive on the soil surface as mummified berries but the pathogen was detected mostly within flower buds and less so in blueberry twigs and fruit trusses. Infection of developing flower buds in May–June of the preceding growing season gave the highest inoculum recovery in the following year. Two commercial fungal biocontrol agents, Prestop (Gliocladium catenulatum) and PlantShield (Trichoderma harzianum), each reduced anthracnose development in 2003 and 2004 by up to 45% when sprayed three times onto plants between flowering and fruit ripening.
Effects of different cultivated or weed grasses, grown as pure stands or in combination with wheat, on take‐all and its suppression in subsequent wheat crops
Authors: Gutteridge R. J. , Jenkyn J. F. , Bateman G. L.
Published: June 2006

Grass species were grown in plots, as pure stands or mixed with wheat, after a sequence of wheat crops in which take‐all (Gaeumannomyces graminis var. tritici) had developed. Annual brome grasses maintained take‐all inoculum in the soil as well as wheat (grown as a continuous sequence), and much better than cultivated species with a perennial habit. Take‐all developed more in wheat grown after Anisantha sterilis (barren brome) or Bromus secalinus (rye brome), with or without wheat, than in continuous grass‐free wheat in the same year, where take‐all decline was apparently occurring. It was equally or more severe, however, in wheat grown after Lolium perenne (rye‐grass) or Festuca arundinacea (tall fescue), despite these species having left the least inoculum in the soil. It was most severe in plots where these two grasses had been grown as mixtures with wheat. It is postulated that the presence of these grasses inhibited the development of take‐all‐suppressive microbiota that had developed in the grass‐free wheat crops. The effects of the grasses appeared to be temporary, as amounts of take‐all in a second subsequent winter wheat test crop were similar after all treatments. These results have important implications for take‐all risk in wheat and, perhaps, other cereal crops grown after grass weed‐infested cereals or after set‐aside or similar 1‐year covers containing weeds or sown grasses, especially in combination with cereal volunteers. They also indicate that grasses might be used experimentally in wheat crop sequences for investigating the mechanisms of suppression of, and conduciveness to, take‐all.
A phylogenetic reassessment ofHyalennaForbes andDircennaDoubleday, with a revision ofHyalenna(Lepidoptera: Nymphalidae: Ithomiinae)
Authors: Willmott Keith R. , Lamas Gerardo
Published: June 2006

Abstract. A morphological study of adults and immature stages and a cladistic analysis were conducted to clarify the relationships amongst members of the sister nymphalid butterfly generaDircennaDoubleday andHyalennaForbes. Two species formerly included inDircenna,Ithomia paradoxaStaudinger andDircenna hugiaSchaus, clustered withIthomia perasippa, the type species ofHyalenna. Therefore, the first two species are transferred fromDircennatoHyalenna(comb.n.).HyalennaandDircennaas now conceived are both monophyletic and well supported by morphological apomorphies and branch support measures. The taxonomy and classification ofHyalennaare reviewed and seven species and twenty‐four taxa are recognized, including one new species,Hyalenna buckleyisp.n., and eleven new subspecies:Hyalenna paradoxa incachacassp.n.,H. perasippa valenciassp.n.,H. perasippa ortygiosassp.n.,H. perasippa solitariassp.n.,H. buckleyi pomacochassp.n.,H. alidella exsulansssp.n.,H. alidella cinereolassp.n.,H. alidella vescassp.n.,H. sulmona balsamicassp.n.,H. sulmona hyalinassp.n.andH. sulmona tersassp.n.A key for the identification of all taxa, and illustrations of male and female genitalia for all species and adult specimens of all taxa (where known), are presented. The natural history of each species is summarized and the immature stages ofH. paradoxaandH. sulmonaare described for the first time.
A phylogenetic study of Dermestidae (Coleoptera) based on larval morphology
Authors: Kiselyova Tatiana , Mchugh Joseph V.
Published: June 2006

Abstract. The results of a phylogenetic analysis of Dermestidae (Coleoptera) based on the morphology of immature stages are presented and implications for the classification of the family are discussed. The monophyly of ((Orphilus) + (Dermestidae) + (Endecatomidae (Bostrichidae + Anobiidae))) is strongly supported. Dermestidae, excludingOrphilusErichson, forms a monophyletic group. The phylogenetic position of the Orphilinae remains enigmatic. The hypothesized relationships of the remaining dermestid subfamilies are (Thorictinae (Dermestinae (Attageninae (Megatominae + Trinodinae)))). Phylogenetically informative morphological characters of larvae and pupae are illustrated and described. Character state transformations implied by the phylogenetic hypothesis are discussed. New morphological observations are provided, including the first records of the presence of gastric caeca in the larva ofDermestesL., and the first report of the number of Malpighian tubules and the number of abdominal ganglia in Dermestidae, Bostrichidae, Anobiidae, Nosodendridae and Derodontidae. The form of the mandibular base is described for the first time for Thylodriini Beal and Trinodini Beal. The fossil record and distribution of extant Dermestidae are discussed in the light of the phylogenetic hypothesis. The origin of the family is hypothesized to be in the Late Cretaceous.
Potential of environmental models to predict meningitis epidemics in Africa
Authors: Thomson Madeleine C. , Molesworth Anna M. , Djingarey Mamoudou H. , Yameogo K. R. , Belanger Francois , Cuevas Luis E.
Published: June 2006

Objectives  Meningococcal meningitis is a major public health problem in Africa. This report explores the potential for climate/environmental models to predict the probability of occurrence of meningitis epidemics.

Methods  Time series of meningitis cases by month and district were obtained for Burkina Faso, Niger, Mali and Togo (536 district‐years). Environmental information (1989–1999) for the continent [soil and land‐cover type, aerosol index, vegetation greenness (NDVI), cold cloud duration (CCD) and rainfall] was used to develop models to predict the incidence of meningitis. Meningitis incidence, dust, rainfall, NDVI and CCD were analysed as anomalies (mean minus observed value). The models were developed using univariate and stepwise multi‐variate linear regression.

Results  Anomalies in annual meningitis incidence at district level were related to monthly climate anomalies. Significant relationships were found for both estimates of rainfall and dust in the pre‐, post‐ and epidemic season. While present in all land‐cover classes these relationships were strongest in savannah areas.

Conclusions  Predicting epidemics of meningitis could be feasible. To fully develop this potential, we require (a) a better understanding of the epidemiological and environmental phenomena underpinning epidemics and how satellite derived climate proxies reflect conditions on the ground and (b) more extensive epidemiological and environmental datasets. Climate forecasting tools capable of predicting climate variables 3–6 months in advance of an epidemic would increase the lead‐time available for control strategies. Our increased capacity for data processing; the recent improvements in meningitis surveillance in preparation for the distribution of the impending conjugate vaccines and the development of other early warning systems for epidemic diseases in Africa, favours the creation of these models.
Can a comprehensive voucher programme prompt changes in doctors’ knowledge, attitudes and practices related to sexual and reproductive health care for adolescents? A case study from Latin America
Authors: Meuwissen Liesbeth E. , Gorter Anna C. , Kester Arnold D. M. , Knottnerus J. A.
Published: June 2006

Objectives  To evaluate whether participation in a competitive voucher programme designed to improve access to and quality of sexual and reproductive health care (SRH‐care), prompted changes in doctors’ knowledge, attitudes and practices.

Methods  The voucher programme provided free access to SRH‐care for adolescents. Doctors received training and guidelines on how to deal with adolescents, a treatment protocol, and financial incentives for each adolescent attended. To evaluate the impact of the intervention on doctors, nearly all participating doctors (n = 37) were interviewed before the intervention and 23 were interviewed after the intervention. Answers were grouped in subthemes and scores compared using nonparametric methods.

Results  The initial interviews disclosed deficiencies in doctors’ knowledge, attitudes and practices relating to adolescent SRH‐issues. Gender and age of the doctor were not associated with the initial scores. Comparing scores from before and after the intervention revealed significant increases in doctors’ knowledge of contraceptives (P = 0.003) and sexually transmittable infections (P < 0.001); barriers to contraceptive use significantly diminished (P < 0.001 and P = 0.003); and some attitudinal changes were observed (0 = 0.046 and P = 0.11). Doctors became more aware of the need to improve their communication skills and were positive about the programme.

Conclusions  This study confirmed provider related barriers that adolescents in Nicaragua may face and reinforces the importance of focusing on the quality of care and strengthening doctors’ training. Participation in the voucher programme resulted in increased knowledge, improved practices and, to a lesser extent, in changed attitudes. A competitive voucher programme with technical support for the participating doctors can be a promising strategy to prompt change.
Hospital and community surveys reveal the severe public health problem and socio‐economic impact of human echinococcosis in Ningxia Hui Autonomous Region, China
Authors: Yang Y. R. , Williams G. M. , Craig P. S. , Sun T. , Yang S. K. , Cheng L. , Vuitton D. A. , Giraudoux P. , Li X. , Hu S. , Liu X. , Pan X. , McManus D. P.
Published: June 2006

A comprehensive study of human echinococcosis (caused by Echinococcus granulosus or E. multilocularis), including assessment of hospital records, community surveys and patient follow‐up, was conducted in Ningxia Hui Autonomous Region (NHAR), China. In contrast to hospital records that showed 96% of echinococcosis cases were caused by cystic echinococcosis (CE), 56% of cases detected in active community surveys were caused by alveolar echinococcosis (AE). The AE and CE cases co‐existed frequently in the same village, even occurring in the same patient. A serious public health problem caused by echinococcosis was evident in southern NHAR, typified by: a long diagnostic history for both AE and CE (7.5 years) compared with a shorter treatment history (4.7 years); a significant mortality rate (39%) caused by AE in one surveyed village, where patients had no previous access to treatment; family aggregation of CE and AE cases; a high proportion of both AE (62.5%) and CE (58%) in females; a high rate of recurrent surgery (30%) for CE demonstrated by surgical records; and frequent symptomatic recurrences (51%) because of discontinuous or sporadic access to chemotherapy for AE. The disease burden for both human AE and CE is thus very severe among these rural communities in NHAR, and this study provides the first attempt to determine the costs of morbidity and surgical intervention of human CE and AE cases both at the hospital and community level in this setting. This information may be useful for assessing the cost effectiveness of designing effective public health programs to control echinococcosis in this and other endemic areas in China and elsewhere.
Stronger host response per parasitized erythrocyte in Plasmodium vivax or ovale than in Plasmodium falciparum malaria
Authors: Hemmer Christoph Josef , Holst Friedrich Georg Ernst , Kern Peter , Chiwakata Collins Batsirai , Dietrich Manfred , Reisinger Emil Christian
Published: June 2006

Objective and methods  Fever tends to start at a lower level of parasitemia in Plasmodium vivax or ovale than in P. falciparum malaria, but hyperparasitemia and complications are more likely to occur in P. falciparum malaria. Therefore, we compared the relationship between parasitemia and host response parameters before therapy in 97 patients with P. faciparum malaria (18 with complications), and 28 with P. vivax or ovale malaria.

Results  In both types of malaria, parasitemia correlated with blood levels of tumour necrosis factor alpha (TNF‐alpha), lactate dehydrogenase (LDH), Thrombin–antithrombin III (TAT) and elastase, and these parameters were higher in P. falciparum malaria than in P. vivax or ovale malaria. In contrast, the ratios of TNF‐alpha, TAT, elastase, and LDH per parasitized erythrocyte were higher in P. vivax or ovale malaria than in uncomplicated P. falciparum malaria. They were lowest in complicated disease. Multivariate regression analysis confirmed that parasitemia did not affect these differences.

Conclusion  The host response may reach full strength at lower parasitemia in Plasmodium vivax or ovale, than in P. falciparum malaria. With hyperparasitemia in P. falciparum malaria, the host response seems to be unable to control parasite multiplication.
Process evaluation of the Senegal‐Community Nutrition Project: an adequacy assessment of a large scale urban project
Authors: Gartner Agnès , Maire Bernard , Kameli Yves , Traissac Pierre , Delpeuch Francis
Published: June 2006

Objective  Although essential for understanding the reasons for success or failure of large scale nutritional interventions, process evaluation results are rarely reported. Our objective was to assess whether the process output objectives of the Community Nutrition Project (CNP) in Senegal, West Africa, were adequately met.

Methods  An adequacy assessment study based on monitoring data for individuals collected during the CNP was used to assess ‘fidelity’, ‘extent’ and ‘reach’ of participants recruitment and of the services provided. The CNP provided underweight or nutritionally at risk 6‐ to 35‐month‐old children in poor districts with monthly growth monitoring and promotion and a weekly food supplementation for 6 month periods, provided that mothers attended weekly nutrition education sessions. An exhaustive sample of the participating children (n = 4084) in Diourbel was used for evaluation over the first 2 years.

Results  At recruitment, only 66% of children were underweight (vs. 90% expected) varying with the CNP center and cohort, and the child's sex and age. Attendance at growth monitoring reached expected levels (93%vs. 90%) whereas numbers of food supplements distributed and education sessions attended were lower than expected (45%vs. 90% and 62%vs. 80%, respectively). At the end of follow‐up, 61% of underweight children recovered vs. 80% expected.

Conclusions  Because of CNP design for underweight diagnosis and bias in the targeting process, respect for selection criteria was low and consequently under coverage and leakage occurred. Besides a globally satisfactory process, wide discrepancies were observed between CNP centres concerning the utilization and effectiveness of services. This formative evaluation helped diagnose weaknesses; ongoing feedback enabled the CNP to improve targeting and supply of supplements. It also informed a larger impact evaluation. Some generalizable lessons for similar programmes have been highlighted.