bluuebunny/crossref_metadata_2025 huggingface dataset:
Effects of maternal diet quality on offspring performance in the rove beetle Tachyporus hypnorum
Authors: KYNEB ANN , TOFT SØREN
Published: July 2006

Abstract1. The reproductive output of an individual is known to be influenced by diet quality, but the quality of the parent's diet can also influence the performance of the offspring. Dietary maternal effects may interact with the effects of the offspring's diet to produce a variety of response patterns.

2. Maternal effects were investigated in a polyphagous predator, the rove beetleTachyporus hypnorum, using three single‐species diets: two low‐quality diets consisting of the aphidsSitobion avenaeandRhopalosiphum padi, and the high‐quality controlDrosophila melanogasterdiet. Offspring of females fed these diets were raised on the same monotypic diets and allowed to reproduce. Several fitness parameters were measured to indicate possible maternal effects in both F1 and F2 generations.

3. Maternal diet effects in F1 were found in egg size, hatching success, time to hatching, larval development time, larval survival, and sex ratio. Both aphid diets resulted in smaller eggs. A diet ofR. padiresulted in reduced hatching success, longer time spent in the egg stage, and a female‐biased sex ratio. A maternal diet ofR. padialso prolonged larval development onS. avenaediet, while a maternal diet ofS. avenaedecreased survival on theR. padidiet. These effects were independent of egg size.

4. A maternal diet ofR. padienhanced the survival of F1 larvae raised on the same diet. Developmental selection operating through a high egg mortality may be the explanation for this seemingly positive effect.

5. Sitobion avenaealone caused a significant reduction in the hatching success of F2 eggs, thus revealing grandmaternal effects.

6. The prediction that polyphagous predators are less likely to evolve adaptive maternal effects is supported by the fact that none of the documented maternal effects could be interpreted as adaptive.
Host plant defences and voltinism in European butterflies
Authors: CIZEK LUKAS , FRIC ZDENEK , KONVICKA MARTIN
Published: July 2006

Abstract1. With respect to seasonal availability for herbivores, plants defended by synthesising qualitative compounds differ from those protected by accumulation of quantitative macromolecules, leaf toughness, and low water and/or nutrient content. While the palatability of the former plants remains relatively constant during the season, the palatability of the latter group decreases with leaf age.

2. It was hypothesised that in seasonal temperate environments, quantitative plant defences should restrict the annual numbers of insect generations. To test this hypothesis, European butterflies were used as a model, both non‐corrected regressions and tests controlling for phylogeny were carried out, and potentially confounding factors such as body size or occurrence in short‐season environments were treated as covariables.

3. Non‐phylogenetically controlled regressions corroborated that butterflies feeding on quantitatively protected hosts (woody plants + grasses) form fewer generations than species feeding on qualitatively protected forbs. Plant defences fitted voltinism better than butterfly size, and remained significant even after controlling for short seasons. Using independent contrasts, feeding on woody plants plus grasses, and feeding on woody plants only, predicted fewer generations. These patterns, however, applied exclusively for foliage‐feeding species.

4. The association between plant defences and voltinism represents a hitherto overlooked pattern in the ecology of temperate herbivores. It may explain why large insects tend to form fewer generations and feed on structurally complex hosts, and why some species remain monovoltine although they are not restricted by short season.
Does variation in female body size affect nesting success in Dawson’s burrowing bee, Amegilla dawsoni (Apidae: Anthophorini)?
Authors: ALCOCK JOHN , SIMMONS LEIGH W , BEVERIDGE MAXINE
Published: July 2006

Abstract 1. Females of Dawson’s burrowing bees vary in body weight over a twofold range. Despite the potential for differences in body weight to affect several aspects of the competition among nesting females, no clear advantages were documented for larger females.

2. Nesting females were not consistently larger than emerging females, nor was there a consistent relationship between body size and the weight of pollen and nectar carried to the nest on provisioning trips. At one nesting location, larger females did not produce larger pre‐pupal offspring nor did they produce offspring at a faster rate than their smaller nesting companions.

3. In addition, large body size was not associated with greater success in nest defence despite the fact that nesting females regularly encountered intruders in their burrows. Residency, not body size, determined the outcome of almost all contests for control of a nest burrow. The absence of a large body size effect here appears to stem from an intruder strategy designed to enable nest‐searching females to acquire burrows that had been abandoned through death or dispersal of their original owners rather than securing existing nests through an aggressive takeover strategy.

4. Thus, although large body size conveys significant fitness advantages to males, this attribute does not promote female success in either provisioning or defending their nests.
Biodiversity in tropical agroforests and the ecological role of ants and ant diversity in predatory function
Authors: PHILPOTT STACY M. , ARMBRECHT INGE
Published: July 2006

Abstract1. Intensive agricultural practices drive biodiversity loss with potentially drastic consequences for ecosystem services. To advance conservation and production goals, agricultural practices should be compatible with biodiversity. Traditional or less intensive systems (i.e. with fewer agrochemicals, less mechanisation, more crop species) such as shaded coffee and cacao agroforests are highlighted for their ability to provide a refuge for biodiversity and may also enhance certain ecosystem functions (i.e. predation).

2. Ants are an important predator group in tropical agroforestry systems. Generally, ant biodiversity declines with coffee and cacao intensification yet the literature lacks a summary of the known mechanisms for ant declines and how this diversity loss may affect the role of ants as predators.

3. Here, how shaded coffee and cacao agroforestry systems protect biodiversity and may preserve related ecosystem functions is discussed in the context of ants as predators. Specifically, the relationships between biodiversity and predation, links between agriculture and conservation, patterns and mechanisms for ant diversity loss with agricultural intensification, importance of ants as control agents of pests and fungal diseases, and whether ant diversity may influence the functional role of ants as predators are addressed. Furthermore, because of the importance of homopteran‐tending by ants in the ecological and agricultural literature, as well as to the success of ants as predators, the costs and benefits of promoting ants in agroforests are discussed.

4. Especially where the diversity of ants and other predators is high, as in traditional agroforestry systems, both agroecosystem function and conservation goals will be advanced by biodiversity protection.
Dispersal and foraging behaviour ofPlatygaster californica: hosts can’t run, but they can hide
Authors: DARROUZET‐NARDI ANTHONY , HOOPES MARTHA F. , WALKER JESSE D. , BRIGGS CHERYL J.
Published: July 2006

Abstract1. Host–parasitoid models often identify foraging behaviour and dispersal distance as important for system persistence.

2. Laboratory observations and field trials were used to characterise foraging behaviour and dispersal capability ofPlatygaster californicaAshmead (Platygasteridae), a parasitoid of the gall midgeRhopalomyia californicaFelt (Cecidomyiidae).

3. Although foraging parasitoids meticulously searched plants in laboratory observations, none of the laboratory trials resulted in 100% parasitism, and the proportion of parasitism declined as midge egg density increased.

4. The field trials showed that the distribution of parasitism over distance from a central release point was hump‐shaped, as predicted by a simple diffusion model. Mean parasitoid dispersal distance was 4.5 m, considerably farther than the 1.7 m mean midge dispersal found in previous work.

5. Although the parasitoid appears to search thoroughly for midge eggs and to disperse farther than the midge, the results of this study show how this host–parasitoid system may persist due to spatially variable incomplete parasitism.
The deleterious effects of salinity stress on leafminers and their freshwater host
Authors: SCHILE LISA , MOPPER SUSAN
Published: July 2006

Abstract 1. Salinity is an important cause of abiotic stress in wetland communities yet little is known about its consequences for freshwater plants and their insect herbivores. The goal of this study was to test the effect of salinity on a leafmining insect, Cerodontha iridiphora, and its herbaceous host plant, Iris hexagona.

2. Leafminer performance was evaluated on irises grown in control and saline treatments, and the effects of salinity and herbivory on leaf quality and mortality was measured.

3. Leafminer density and size were significantly lower on irises grown in saline water compared with freshwater.

4. Both salinity and herbivory accelerated leaf senescence and mortality, and their combined effects increased tissue loss by an order of magnitude compared with controls.

5. Leafminers acted as nutrient sinks. The undamaged regions of mined leaves contained 40% less nitrogen than unmined leaves, providing a mechanism for the premature leaf mortality.

6. Salinity was detrimental to the performance and survival of both the iris leafminer and its host plant. We propose that glycophytic host plants and their insect herbivores will suffer more than halophytic communities from environmental salinity because they lack the adaptive mechanisms to tolerate this potent physiological stress.
Aminoguanidine prevents arterial stiffening in a new rat model of type 2 diabetes
Authors: Chang K.‐C. , Tseng C.‐D. , Wu M.‐S. , Liang J.‐T. , Tsai M.‐S. , Cho Y.‐L. , Tseng Y.‐Z.
Published: July 2006

Background  Formation of advanced glycation end‐products (AGEs) on collagen within the arterial wall may be responsible for the development of diabetic vascular injury. This study focused on investigating the role of aminoguanidine (AG), an inhibitor of AGE formation, in the prevention of noninsulin‐dependent diabetes mellitus (NIDDM)‐derived arterial stiffening and cardiac hypertrophy in rats.

Materials and methods  The NIDDM was induced in male Wistar rats, which were administered intraperitoneally with 180 mg kg−1 nicotinamide (NA) 30 min before an intravenous injection of 50 mg kg−1 streptozotocin (STZ). After induction of diabetes mellitus type 2, animals receiving daily peritoneal injections with 50 mg kg−1 AG for 8 weeks were compared with the age‐matched, untreated, diabetic controls.

Results  After exposure to AG, the STZ‐NA diabetic rats had improved aortic distensibility, as evidenced by 18·8% reduction of aortic characteristic impedance (P < 0·05). Treatment of the experimental syndrome with AG also resulted in a significant increase in wave transit time (+23·7%, P < 0·05) and a decrease in wave reflection factor (−26·6%, P < 0·05), suggesting that AG may prevent the NIDDM‐induced augmentation in systolic load of the left ventricle. Also, the glycation‐derived modification on aortic collagen was found to be retarded by AG. The diminished ratio of left ventricular weight to body weight suggested that prevention of the diabetes‐related cardiac hypertrophy by AG may correspond to the drug‐induced decline in aortic stiffening.

Conclusions  Long‐term administration of AG to the STZ‐NA diabetic rats imparts significant protection against the NIDDM‐derived impairment in vascular dynamics, at least partly through inhibition of the AGE accumulation on collagen in the arterial wall.
Modulation of HER2 expression by ferulic acid on human breast cancer MCF7 cells
Authors: Chang C. J. , Chiu J. H. , Tseng L. M. , Chang C. H. , Chien T. M. , Wu C. W. , Lui W. Y.
Published: July 2006

Background  The molecular mechanisms underlying the mitogenic effect of ferulic acid (FA), an active compound derived from Angelica sinensis, have never been elucidated. It was the aim of this study to investigate the proliferative effect of FA on human breast cancer cell lines and to elucidate its modulation mechanism on HER2 expression in MCF7 line.

Materials and methods  By using MCF7 (oestrogen receptor‐positive; ER+, HER2‐low), BT474 (ER+, HER2‐high), MDAMB231 (ER–, HER2‐low) and SKBR3 (ER–, HER2‐high) human breast cancer cell lines as in vitro models, the mitogenic effects of FA were assessed by trypan blue dye exclusion assay and DNA flow cytometry. Ferulic acid‐modulated cell signalling and HER2 gene expression were evaluated in MCF7 line by Western blot and real‐time RT‐PCR analysis.

Results  Ferulic acid ER‐dependently stimulated cell proliferation on MCF7 cells in a concentration‐dependent manner. The HER2 oncogene (one of the prognostic factors of breast cancer) and ESR1 gene (oestrogen receptor‐alpha; ERα) transcription were markedly up‐regulated by FA treatment. Besides, HER2 signalling and its downstream molecules such as AKT and ERK1/2 were involved in FA‐modulated ERα and cyclin D1 synthesis. Addition of anti‐HER2 antibody, trastuzumab, abrogated FA‐enhanced proliferative effect on MCF7 cells, indicated a positive feedback control for the action of HER2 in this setting. The fact that the ER antagonist blocked most of the FA‐up‐regulated HER2 expression, and that trastuzumab down‐regulated ERα gene expression, suggested a cross‐talk between ERα and HER2 signalling on MCF7 cells.

Conclusions  The authors’ conclude that FA causes human breast cancer cell proliferation by up‐regulation of HER2 and ERα expression.
Carbon and nitrogen stocks in relation to organic matter fractions, aggregation and pore size distribution in no‐tillage and conventional tillage in northern France
Authors: Oorts Katrien , Bossuyt H. , Labreuche J. , Merckx R. , Nicolardot B.
Published: July 2006

The magnitude of and mechanisms for long‐term differences in soil organic matter stocks under no‐tillage and conventional tillage are still relatively poorly known. We quantified differences in total C and N stocks after 32 years of no‐tillage (NT) and conventional tillage (CT) in plots with a long‐term cultivation history before differentiation and the same annual C and N returns to the soil. The role of physical protection of organic matter (OM) in these stock differences was further investigated by examining the changes at different levels of structural complexity, i.e. organic matter fractions, aggregation and pore‐size distribution. Four structural zones were sampled: loose and dense soil zones under CT and the 0–5 cm (rich in OM) and 5–20 cm (massive structure) soil layers under NT. The C and N stocks, calculated for an equivalent mass of dry soil, were only 10–15% larger under NT than under CT. Mineral‐associated N and particulate organic matter accounted for about 50% of the difference in N stocks. However, 66% of the total difference in C stocks was due to differences in the particulate organic matter (58%) and free residues (8%) fractions. The additional C and N under NT were almost exclusively situated in aggregates larger than 250 μm in diameter. Our results suggest that physical protection of OM under NT contributes significantly to the differences in C and N stocks between NT and CT by (i) enhanced macroaggregate formation in the 0–5 cm layer due to greater microbial activity and OM content and (ii) a better protection of soil organic matter in the 5–20 cm layer due to the presence of small pores and lack of soil disruption by tillage or climate.
Humus structure during a spruce forest rotation: quantitative changes and relationship to soil biota
Authors: Chauvat M. , Ponge J. F. , Wolters V.
Published: July 2006

Temporal dynamics of edaphic communities affect numerous processes in forests and also strongly influence the soil’s organic matter status. We have linked long‐term changes in the formation of organic matter (using humus micromorphological analyses) to changes in the soil’s community structure during a spruce forest cycle on acid soil. The study was carried out at four sites of different age‐classes in the Tharandter forest, Germany. The composition of the deeper humus layers (OH, A) was stable. Herbaceous litter, recent spruce litter, fragmented spruce litter, decomposed litter and faeces and fungi, which contributed to the organic layer (OL and OH horizon), significantly changed during the forestry cycle, especially with the shift from the early stage to intermediate stages. Parallel changes of the faunal assemblage of the soil showed quantitative relations between major stages of the forest development, humus dynamics and soil community composition. The herbaceous litter was correlated with surface‐dwelling Collembola and microbial properties with faeces and fungi. Our results suggest that the long‐term stability of deep organic layers provides a refuge for decomposers and detritivores that allows a rapid response to both adverse and favourable conditions, taking place in OL and OF layers. Furthermore, the opening of the canopy in mature stands allows the decomposers to adapt to changes in resource input long before the collapse of the forest.
Priming the productivity pump: flood pulse driven trends in suspended algal biomass distribution across a restored floodplain
Authors: AHEARN DYLAN S. , VIERS JOSHUA H. , MOUNT JEFFREY F. , DAHLGREN RANDY A.
Published: July 2006

1. Chlorophyll a (Chl a) distribution across a 0.36 km2 restored floodplain (Cosumnes River, California) was analysed throughout the winter and spring flood season from January to June 2005. In addition, high temporal‐resolution Chl a measurements were made in situ with field fluorometers in the floodplain and adjacent channel.

2. The primary objectives were to characterise suspended algal biomass distribution across the floodplain at various degrees of connection with the channel and to correlate Chl a concentration and distribution with physical and chemical gradients across the floodplain.

3. Our analysis indicates that periodic connection and disconnection of the floodplain with the channel is vital to the functioning of the floodplain as a source of concentrated suspended algal biomass for downstream aquatic ecosystems.

4. Peak Chl a levels on the floodplain occurred during disconnection, reaching levels as high as 25 μg L−1. Chl a distribution across the floodplain was controlled by residence time and local physical/biological conditions, the latter of which were primarily a function of water depth.

5. During connection, the primary pond on the floodplain exhibited low Chl a (mean = 3.4 μg L−1) and the shallow littoral zones had elevated concentrations (mean = 4.6 μg L−1); during disconnection, shallow zone Chl a increased (mean = 12.4 μg L−1), but the pond experienced the greatest algal growth (mean = 14.7 μg L−1).

6. Storm‐induced floodwaters entering the floodplain not only displaced antecedent floodplain waters, but also redistributed floodplain resources, creating complex mixing dynamics between parcels of water with distinct chemistries. Incomplete replacement of antecedent floodplain waters led to localised hypoxia in non‐flushed areas.

7. The degree of complexity revealed in this analysis makes clear the need for high‐resolution spatial and temporal studies such as this to begin to understand the functioning of dynamic and heterogeneous floodplain ecosystems.
Cell death in lake phytoplankton communities
Authors: AGUSTÍ SUSANA , ALOU EVA , HOYER MARK V. , FRAZER THOMAS K. , CANFIELD DANIEL E.
Published: July 2006

1. The fraction of living and dead phytoplankton cells in seven Florida lakes was assessed by using the cell digestion assay, a non‐staining membrane permeability test. The cell digestion assay is an effective method to analyse cell viability in complex natural phytoplankton communities. 2. The lakes examined ranged widely in phytoplankton abundance and community composition. The variability in the percentage of living cells (% LC) was high among the taxonomic groups forming the different phytoplankton communities, ranging from 19.7% to 98% LC. 3. All cells within single cyanobacteria filaments were determined to be either dead or alive, suggesting physiological integration of the cells within colonies. 4. Within each lake, the dominant taxa generally exhibited the highest proportion of living cells. A high proportion of living cells was found to be a characteristic of the different taxa forming the communities of eutrophic lakes. The average value for the % LC for all groups comprising the phytoplankton communities in each of the lakes ranged from 29.9 ± 7.2 to 80.4 ± 4.0 (mean ± SE) and varied strongly and positively with chlorophyll a concentration. 5. These results suggest phytoplankton cell death to be an important process structuring phytoplankton communities in lakes, particularly in oligotrophic ones.
Habitat selection in spatially heterogeneous environments: a test of foraging behaviour in the clonal submerged macrophyte Vallisneria spiralis
Authors: XIAO KEYAN , YU DAN , WANG JINWANG
Published: July 2006

1. To test whether clonal macrophytes can select favourable habitats in heterogeneous environments, clonal fragments of the stoloniferous submerged macrophyte Vallisneria spiralis were subjected to conditions in which light intensity and substratum nutrients were patchily distributed. The allocation of biomass accumulation and ramet production of clones to the different patches was examined.

2. The proportion of both biomass and ramet number of clones allocated to rich patches was significantly higher than in poor patches. The greatest values of both clone and leaf biomass were produced in the heterogeneous light treatment, in which clones originally grew from light‐rich to light‐poor patches, while clones produced the most offspring ramets in the treatments with heterogeneous substratum nutrients. Similarly, root biomass had the highest values in nutrient‐rich patches when clones grew from nutrient‐rich to nutrient‐poor patches.

3. The quality of patches in which parent ramets established significantly influenced the foraging pattern. When previously established in rich patches, a higher proportion of biomass was allocated to rich patches, whereas a higher proportion of ramet number was allocated to rich patches when previously established in poor patches.

4. Results demonstrate that the clonal macrophyte V. spiralis can exhibit foraging in submerged heterogeneous environments: when established under resource‐rich conditions V. spiralis remained in favourable patches, whereas if established in adverse conditions it could escape by allocating more ramets to favourable patches.
Differential vulnerability determines the diet of a slow‐moving predatory stream insect
Authors: MUOTKA TIMO , JUNTUNEN ANTTI , MEISSNER KRISTIAN
Published: July 2006

1. We investigated the diet and prey electivity of Rhyacophila obliterata, a slow‐moving invertebrate predator capable of hunting in high‐flow microhabitats, and quantified the components of the predation sequence of fifth‐instar larvae foraging on mobile (Baetis mayflies, Amphinemura stoneflies) versus semi‐sessile (larval blackflies) prey.

2. In the field, fifth‐instar Rhyacophila consistently took more larval blackflies than more mobile prey. In behavioural trials, the number of attacks by Rhyacophila differed significantly between prey types, mobile prey being attacked more often than blackflies. Capture success, by contrast, was highest for blackflies, whereas Amphinemura and Baetis were rarely captured. In mixed‐prey feeding trials, Rhyacophila showed strong preference for blackflies and equally strong avoidance of Amphinemura and Baetis.

3. For mobile prey, the risk of being captured by this sluggish predator is very low, so they can afford to be in close contact with it. Rhyacophila was almost unable to capture any other prey but blackflies, resulting in strong passive selection for blackflies.

4. Therefore, the diet of fifth‐instar Rhyacophila can be predicted from laboratory observations and prey behaviour is the major determinant of the diet of this invertebrate predator.
Ambulatory 24‐h oesophageal impedance–pH recordings: reliability of automatic analysis for gastro‐oesophageal reflux assessment
Authors: Roman S. , Bruley Des Varannes S. , Pouderoux P. , Chaput U. , Mion F. , Galmiche J.‐p. , Zerbib F. ,   Consortium de Recherche Indépendant sur le Traitement et l'Exploration du Reflux gastro‐oesophagien et de l'Endobrachyoesophage (CRITERE)
Published: July 2006

Abstract  Oesophageal pH–impedance monitoring allows detection of acid and non‐acid gastro‐oesophageal reflux (GOR) events. Visual analysis of impedance recording requires expertise. Our aim was to evaluate the efficacy of an automated analysis for GOR assessment. Seventy‐three patients with suspected GORD underwent 24‐h oesophageal pH–impedance monitoring. Recordings analysis was performed visually (V) and automatically using Autoscan function (AS) of Bioview® software. A symptom index (SI) ≥50% was considered for a significant association between symptoms and reflux events. AS analysis detected more reflux events, especially non‐acid, liquid, pure gas and proximal events. Detection of oesophageal acid exposure and acid reflux events was similar with both analyses. Agreement between V and AS analysis was good (Kendall's coefficient W > 0.750, P < 0.01) for all parameters. During pH–impedance studies, 65 patients reported symptoms. As compared to visual analysis, the sensitivity and specificity of a positive SI determined by AS were respectively 85.7% and 80% for all reflux events, 100% and 98% for acid reflux and 33% and 87.5% for non‐acid reflux. Despite good agreement with visual analysis, automatic analysis overestimates the number of non‐acid reflux events. Visual analysis remains the gold standard to detect an association between symptoms and non‐acid reflux events.
Serotonin transporter gene polymorphism and irritable bowel syndrome
Authors: Park J. M. , Choi M‐g. , Park J‐a. , Oh J. H. , Cho Y. K. , Lee I. S. , Kim S. W. , Choi K. Y. , Chung I‐s.
Published: July 2006

Abstract  Polymorphisms in the promoter region of the serotonin reuptake transporter (SERT) gene may underlie the disturbance in gut function in patients with irritable bowel syndrome (IBS). Association studies of SERT polymorphisms and IBS have shown diverse results among different countries, which might be due to racial and subject composition differences. The aim of this study was to assess the potential association between SERT polymorphisms and IBS in Koreans. A total of 190 IBS patients, who met the Rome II criteria, and 437 healthy controls were subjected to genotyping. SERT polymorphisms differed in the IBS and control groups (P = 0.014). The SERT deletion/deletion genotype occurred with greater frequency in the diarrhoea‐predominant IBS group than in the controls. A strong genotypic association was observed between the SERT deletion/deletion genotype and diarrhoea‐predominant IBS (P = 0.012). None of the clinical symptoms analysed was significantly associated with the SERT genotypes. The frequency of the SERT insertion/insertion genotype was much lower than that of the other two genotypes. A significant association was observed between the SERT polymorphism and IBS, especially diarrhoea‐predominant IBS, suggesting that the SERT gene is a potential candidate gene involved in IBS in Korea.
Personality: is it a viable endophenotype for genetic studies of bipolar affective disorder?
Authors: Savitz Jonathan B , Ramesar Rajkumar S
Published: July 2006

Progress in identifying the genetic basis of bipolar affective disorder has been disappointing, most probably because of the genetic and phenotypic heterogeneity of the condition. These setbacks have led to the adoption of alternative strategies such as the use of endophenotypes or intermediate traits to identify those individuals at genetic risk for developing the disorder. Gottesman and Gould [Am J Psychiatry (2003), 160:636], in a review of the endophenotypic concept, have suggested five criteria that should be characteristic of a trait in order for it to qualify as an endophenotype. These five criteria are used in order to assess the viability of using personality traits as endophenotypes for genetic analyses of bipolar disorder. A review of the literature suggests that certain personality traits or temperaments are associated with the illness in a state independent manner, that personality is at least partly heritable, and that various temperaments aggregate in the non‐affected relatives of bipolar probands. Nevertheless, it is unclear whether specific personality traits co‐segregate with affectively ill individuals. We conclude that personality profiling of probands and their relatives may facilitate molecular genetic work, but given the fact that personality is itself a complex trait, its use as an endophenotype has certain limitations.
Pediatric bipolar disease: current and future perspectives for study of its long‐term course and treatment
Authors: Strober Michael , Birmaher Boris , Ryan Neal , Axelson David , Valeri Sylvia , Leonard Henrietta , Iyengar Satish , Gill Mary Kay , Hunt Jeffrey , Keller Martin
Published: July 2006

Aim and methods:  Findings from recent long‐term, prospective longitudinal studies of the course, outcome and naturalistic treatment of adults with bipolar illness are highlighted as background for long‐term developmental study of pediatric bipolar illness.

Results:  Accumulating knowledge of bipolar illness in adults underscores a high risk for multiple recurrences through the lifespan, significant medical morbidity, high rates of self‐harm, economic and social burden and frequent treatment resistance with residual symptoms between major episodes. At present, there is no empirical foundation to support any assumption about the long‐term course or outcome of bipolar illness when it arises in childhood or adolescence, or the effects of conventional pharmacotherapies in altering its course and limiting potentially adverse outcomes. The proposed research articulates specific descriptive aims that draw on adult findings and outlines core methodological requirements for such an endeavor.

Conclusions:  Innovations in the description and quantitative analysis of prospective longitudinal clinical data must now be extended to large, systematically ascertained pediatric cohorts recruited through multicenter studies if there is to be a meaningful scientific advance in our knowledge of the enduring effects of bipolar illness and the potential value of contemporary approaches to its management.
Treatment of aggression with risperidone in children and adolescents with bipolar disorder: a case series
Authors: Saxena Kirti , Chang Kiki , Steiner Hans
Published: July 2006

Objectives:  To evaluate the effectiveness and safety of risperidone in children and adolescents with bipolar disorder characterized by aggression and mania, despite treatment with mood stabilizers.

Methods:  A retrospective chart review of patients seen in an outpatient pediatric mood disorders clinic over an 18‐month period was performed. Data were extracted from charts of patients who had a diagnosis of bipolar disorder with aggression that was uncontrolled on a mood stabilizer; as a result, these patients had risperidone added to their regimen.

Results:  Four boys (aged 7–15 years) and two girls (aged 8 and 14 years) were treated with risperidone (mean dosage, 0.85 mg/day) for 3–16 months. Aggressive behavior improved in all patients after risperidone was started and remained improved for the duration of follow‐up. Other symptoms of mania also improved. Risperidone was generally well tolerated. Sedation and akathisia were reported in one patient.

Conclusions:  The addition of risperidone to a mood stabilizer may improve aggression and other symptoms of mania in pediatric patients with bipolar disorder who do not respond adequately to a mood stabilizer alone. The long‐term efficacy and safety of this regimen should be evaluated in a controlled clinical trial.
A cautionary note on the use of antidepressants in postpartum depression
Authors: Sharma Verinder
Published: July 2006

Objectives:  This paper discusses the effect of antidepressant use on the illness course in three women who were treated for first‐onset postpartum depression (PPD) following childbirth.

Methods:  A report of three cases of early‐onset PPD in which bipolarity manifested following antidepressant treatment.

Results:  There was no past history of psychiatric disturbance but in each case there was a family history of bipolar (BP) disorder. Treatment with antidepressants resulted in a highly unstable illness course characterized by a mixed episode, cycle acceleration, and a postpartum psychosis. However, discontinuation of antidepressants and institution of treatment with mood stabilizers and atypical neuroleptics resulted in sustained improvement and symptom remission.

Conclusions:  Caution is urged in the use of antidepressants to treat early‐onset PPD in women at risk for developing BP disorder due to a family history of bipolar illness.
Isoyield Analysis of Barley Cultivar Trials in the Canadian Prairies
Authors: Yang R.‐C. , Stanton D. , Blade S. F. , Helm J. , Spaner D. , Wright S. , Domitruk D.
Published: July 2006

Classification of test sites used for cultivar trials into groups with similar within‐group site performance and response (isoyield groups) is an important step towards identification of appropriate cultivars that are best suited for different productivity levels in farm fields. The objective of this study was to determine isoyield environments in the Canadian prairies based on the analysis of cultivar trials consolidated from individual provinces for barley (Hordeum vulgare L.). Yield data for the analysis were taken from 324 replicated trials at 84 sites across the prairies during 1995–2003. The combined use of regression and cluster analyses of the data normalized for averaging the multi‐year unbalanced data led to a stratification of the 84 sites into 13 isoyield groups. A comparison was made of the distributions of the variability among and within groups according to three modes of grouping: isoyield groups, soil zones and agroecoregions. There was more variability among isoyield groups and correspondingly less within the groups than that among and within soil zones or agroecoreions. Similar contrasting pattern existed for the variance components involving genotype–environment interaction (GEI), although the GEI variability was generally small under all three modes of grouping. Relationships of site sensitivity (regression coefficient) and stability (coefficient of determination) with site productivity were shown to be a useful aid for selecting a subset of test sites in an effort to improve efficiency and quality of future cultivar testing. Thus, isoyield analysis should be a valuable tool for subsetting heterogeneous environments and for reducing GEI impact in cultivar testing and recommendation.
Hybrid and N Fertilization Affect Corn Silage Yield and Quality
Authors: Sheaffer C. C. , Halgerson J. L. , Jung H. G.
Published: July 2006

We determined the effect of N fertilization on dry matter (DM) yield, predicted milk yield, and forage quality of fresh (green chopped) and ensiled forage of two brown midrib (BMR) hybrids, a leafy hybrid, and a conventional silage hybrid. Increasing N rates from 0 to 200 kg ha−1 increased corn grain, stover and whole plant DM yield and milk yield. The forage yield and quality response to N was similar for all hybrids. Nitrogen fertilization increased forage crude protein (CP) concentration but had little effect on other forage quality components. BMR hybrids, F377 and F657, had the lowest grain, stover and whole plant yield but had the highest digestibility and predicted milk yield Mg−1 of forage. Predicted milk yield ha−1 was similar for the BMR, leafy and conventional hybrids. Ensiling reduced starch concentration compared with green chopped forage, but effects on other forage quality variables were less consistent. Hybrid and N fertilization affects were similar for green chopped and ensiled corn forage.
Using Digital Image Analysis to Describe Canopies of Winter Oilseed Rape (Brassica napus L.) during Vegetative Developmental Stages
Authors: Behrens T. , Diepenbrock W.
Published: July 2006

In our experiment digital image processing is used to predict characteristics in a winter oilseed rape canopy. A large series of images was taken in 2002–2003 in close intervals from a measuring area of 1 m2. These images were automatically evaluated by a self‐written computer program analysing the red/green/blue colour channels of each pixel. The number of determined green pixels was then related to the total pixel count of the image. Image evaluation helped to determine canopy structure by digital image analysis subjected to several applications, i.e. soil coverage, leaf area index (LAI), dynamics of plant number during vegetative developmental stages including entire winter season. Furthermore, number of plants per m2 and position of each plant were determined by image analysis. Results show that all parameters are dynamic during the vegetative developmental stages (germination–beginning of flowering) mainly depending on temperature. During the vegetative developmental stages number of plants varied. Emergence lasted 30 days resulting in large differences in growth and development of individual plants. During winter number of plants decreased due to longer phases of frost. Plant growth indicated by dynamics of LAI alternated with phases of cessation due to low temperatures above zero or frost. Reductions in soil coverage and LAI clearly started at daily mean temperatures below 5 °C. After the analysis, differences in LAI as well as changes in number of plants during the early phase crop development can serve (i) as input parameters to growth models, (ii) to improve canopy reflectance measurements by separating spectral signatures of soil and canopy and (iii) to determine and explain heterogeneities within the canopy.
Seedling Growth of Agronomic Crops in Crude Oil Contaminated Soil
Authors: Issoufi I. , Rhykerd R. L. , Smiciklas K. D.
Published: July 2006

Phytoremediation of hydrocarbon‐contaminated soil shows promise as a low‐cost alternative to most remediation methods. This study evaluated seedling growth of six crop species in crude oil contaminated soils. The experiments were conducted in a greenhouse. Weathered crude oil was added to an Ipava silt loam soil at the rate of 0 (control), 10, 50 and 100 g of crude oil kg−1 of soil, which was then placed into pots. Irrigation was used to maintain soil moisture at approximately field capacity. Five seeds of Zea mays, Meticago sativa, Lolium perenne, Triticum aestivum, Glycine max or Vicia villosa were sown per pot. The experimental design was completely randomized with five replications per treatment. Germination and seedling height data were recorded on day 7, 14, 21 and 28. Plants were harvested on day 28, separated into shoots and roots and dried to measure biomass. Analysis of variance was used to determine treatment significance. Significant treatment mean values were separated using Tukey's Honestly Significant Difference Test. Based upon percent emergence and plant biomass production in contaminated soil, Z. mays and G. max seedlings show the greatest potential to enhance remediation.
Durum Wheat under Mediterranean Conditions as Affected by Seed Size
Authors: Royo C. , Ramdani A. , Moragues M. , Villegas D.
Published: July 2006

This study was carried out in order to determine the effect of seed size on the growth and yield of durum wheat. Four field experiments, composed of six durum wheat (Triticum turgidum L. var. durum) varieties and three seeding sizes were conducted in north‐east Spain in 2000 and 2001 in randomized complete block designs. The growth of seedlings was dramatically affected by seed size. Large seeds produced greater plot stands, but the plants had fewer tillers, leaves and spikes and less green area and dry weight than plots from small seeds. Grain yield was 16 % greater in plots from large seeds, which resulted in greater biomass, green area index, spikes per m2 and heavier kernels than in plots from small seeds. Kernel weight was the yield component most related to grain yield in the three seed sizes. The percentage of yield variation explained by kernel weight increased as the weight of kernels increased. This was a consequence of the use of larger seeds, the same effect being observed when the comparison was made between varieties with different kernel weights. Selection for heavy kernel varieties may help to improve the yield of durum wheat in Mediterranean environments similar to that prevailing in north‐east Spain.
Efficiency of 35‐pFractional Factorial Designs Determined Using Additional Information on the Spatial Variability of the Experimental Field
Authors: Załuski D. , Gołaszewski J.
Published: July 2006

The paper presents estimates of the relative efficiency (RE) of the 35‐1(V) and 35‐2(III) fractional factorial designs. Three variants of each fractional design were generated from a one‐replicated 35full factorial design applied in field experiments with pea (Pisum sativumL.). Plant height and seed yield were determined in the study. Additional measurements of soil properties (pH, P, K, Mg) and plant traits determined on the alleys between experimental strips, sown with a single cultivar, were performed in regular nets of sampling points. Geostatistical methods were used to estimate the spatial variation of the experimental field. Information on spatial variation was included in the statistical analysis. It was found that in the 35‐1(V) fractional designs most of the significant effects were the same as in the 35full factorial design. Information from these two types of design was similar, although there was a distinct tendency to higher values of the coefficient of determination R2for linear models of the 35‐1(V) designs. The 35‐2(III) fractional designs were more variable in detecting significant effects. Generally, mean RE was higher in the 35‐2(III) design than in the 35‐1(V) design, but at the same time the standard error of the latter one was distinctly lower. It was also demonstrated that in agricultural field experiments factorial fractional designs are a very good alternative to full factorial designs as concerns the estimation of main and two‐factor interaction effects in the case of the 35‐1(V) designs and main effects in that of the 35‐2(III) designs. Even if the designs have a highly reduced number of treatments to be tested they are equally or more effective than the original 35design from which they were generated, provided that the generator is chosen very carefully and the spatial variation of the experimental field is considered in statistical analysis of the experimental data.
Estimating the digestibility of Sahelian roughages from faecal crude protein concentration of cattle and small ruminants
Authors: Schlecht E. , Susenbeth A.
Published: July 2006

Studies on diet selection and feed intake of ruminants in extensive grazing systems often require the use of simple approaches to determine the organic matter digestibility (OMD) of the ingested feed. Therefore, we evaluated the validity of the one‐factorial exponential regression established by Lukas et al. [Journal of Animal Science 83 (2005) 1332], which estimates OMD from the faecal crude protein (FCP) concentration. The equation was applied to two sets of data obtained with free grazing and pen‐fed cattle, sheep and goats ingesting low and high amounts of green and dry vegetation of Sahelian pastures as well as millet leaves and cowpea hay. Data analysis showed that the livestock species did not influence the precision of estimation of OMD from FCP. For the linear regression between measured and estimated OMD (%) across n = 431 individual observations, a regression coefficient of r2 = 0.65 and a residual standard deviation (RSD) of 5.87 were obtained. The precision of estimation was influenced by the data set (p = 0.033), the type of feed (p < 0.001) and the feeding level (p = 0.009), and interactions occurred between type of feed and feeding level (p = 0.021). Adjusting the intercept and the slope of the established exponential function to the present data resulted in a compression of the curve; while r2 remained unchanged, the RSD of the regression between measured and estimated OMD was reduced, when compared with the results obtained from the equation of Lukas et al. (2005). Estimating OMD from treatment means of FCP greatly improved the correlation between measured and estimated OMD for both the established function and the newly fit equation. However, if anti‐nutritional dietary factors increase the concentration of faecal nitrogen from feed or endogenous origin, the approach might considerably overestimate diet digestibility.
Genetically manipulated pineapple: transgene stability, gene expression and herbicide tolerance under field conditions
Authors: Sripaoraya S. , Keawsompong S. , Insupa P. , Power J. B. , Davey M. R. , Srinives P.
Published: July 2006

Pineapple plants transformed with the bar gene for bialaphos resistance were evaluated for transgene stability, gene expression and tolerance to glufosinate ammonium, the active ingredient of the herbicide Basta® X, under field conditions. Genetically modified plants of the cv. Phuket were micropropagated, rooted and established in a shade house before transfer to an experimental plot. Seven months after transfer to the field, plants were tolerant to 1600 ml/rai of the herbicide Basta® X (stock concentration 15% w/v glufosinate ammonium), this being twice the dose recommended for field application of the herbicide. Genetically modified plants remained green and healthy following spraying with the herbicide. In contrast, non‐transformed pineapple plants of the same cv. became necrotic and died within 21 days of spraying with the herbicide at a reduced concentration of 800 ml/rai. Bar gene stability and expression in clonally‐derived plants were assessed by PCR, RT‐PCR and Southern analyses at 120, 210, 240, 270 and 380 days following transfer of the plants to the field. The bar gene was stable and expressed in transgenic plants throughout the duration of the trial. Fruit characteristics and yield were not affected by transgene introduction and expression. Transgenic plants tolerant to glufosinate ammonium should facilitate more effective weed control in pineapple plantations without damage to the crop.
Use of image cytometry for the early screening of induced autopolyploids
Authors: Muñoz M. , Riegel R. , Seemann P.
Published: July 2006

The rapid and early detection of autotetraploid individuals is a fundamental requirement in genetic improvement programmes based on chromosome duplication. Counting chromosomes provides certainty of the ploidy level of an individual, however, it is very laborious. In this work, image cytometry is proposed as an easy alternative method to detect tetraploid individuals. Plantlets of the species Rhodophiala montana treated with colchicine were karyomorphologically analysed. Based on the Feulgen stain, chromosomes were counted and the integrated density value of interphase nuclei was determined. The average DNA content measured with image cytometry for the polyploid individuals was 1.88 times more than that for the diploid individuals. With this methodology, 100% effectiveness in the selection was achieved, rapidly identifying all autotetraploid individuals.