bluuebunny/crossref_metadata_2025 huggingface dataset:
Clinical implications ofSOCS1methylation in myelodysplastic syndrome
Authors: Wu Shang‐Ju , Yao Ming , Chou Wen‐Chien , Tang Jih‐Luh , Chen Chien‐Yuan , Ko Bo‐Sheng , Huang Shen‐Yi , Tsay Woei , Chen Yao‐Chang , Shen Ming‐Ching , Wang Chiu‐Hwa , Yeh Yo‐Chia , Tien Hwei‐Fang
Published: September 2006

The suppressor of cytokine signalling‐1 (SOCS1) protein is a tumour suppressor. Hypermethylation ofSOCS1gene, resulting in transcriptional silencing, is suggested to play an important role in cancer development. We sought to characteriseSOCS1methylation in primary myelodysplastic syndrome (MDS) and clarify its clinical implications. The methylation status ofSOCS1was analysed by methylation‐specific polymerase chain reaction in 114 patients with primary MDS and serial studies were performed in 29 of them.SOCS1methylation occurred in 54 patients (47·4%), and was more frequent in patients with high‐risk MDS than in those with low‐risk (52·6% vs. 25·8%,P = 0·011).SOCS1methylation was closely associated withNRASmutation (P = 0·010) and inversely associated with good‐risk karyotype (P = 0·021). With a median follow‐up of 17 months (range: 1–231 months), two patients acquiredSOCS1methylation during disease progression. In two patients,SOCS1methylation present at diagnosis, disappeared after haematopoietic stem cell transplantation. Patients withSOCS1methylation had a higher cumulative risk of leukaemic transformation than those without (55·8% vs. 27·7% at 3 years,P = 0·004). This difference remained significant within the subgroup of patients with high‐risk MDS (67·3% vs. 45·1% at 3 years,P = 0·045). This is the first report to demonstrate the clinical relevance ofSOCS1methylation in MDS. It may play an important role in the pathogenesis of MDS, especially among patients with high‐risk subtypes.
When parents use drugs: key findings from qualitative research on parenting and children in Iran
Authors: Pirsaraee Hossein Yahyazadeh
Published: September 2006

This paper reports on the finding of a grounded theory study on drug dependency and parenting in Iran. This study is qualitative in nature; data were obtained through semi‐structured interviews. The grounded theory method was used to guide the analysis. Interviews with 41 opium‐ and heroin‐dependent parents selected from a treatment centre in Rasht, Iran provided detailed information on the impact of drug dependency on parenting. The study focused on drug dependency and parenting and explored the links between them in order to understand the impact of drug dependency on parental duties and responsibilities. The findings showed that parental drug dependency affects various aspects of parenting, including children’s material needs and basic requirements; parent–child relationships; parent–child communication; and the disciplinary strategies of parents. The results showed that children’s material needs and basic requirements may be overshadowed by parents’ drug dependency. It was also discovered that abuse of children by drug‐dependent parents was manifested in three major forms. This study also found that the bonds within families of drug‐dependent parents tended to weaken and that control over children almost disappeared in many cases. Intervention and prevention programmes should be offered to the children of drug‐dependent parents.
Participatory evaluation (II) – translating concepts of reliability and validity in fieldwork
Authors: Crishna B.
Published: September 2006

Background  In developing countries participatory methods are a viable way of evaluating social development projects. It provides a means to look constructively at the strengths and weaknesses in projects, and use the lessons learned to improve planning and implementation. One of the challenges faced, however, is being able to ensure that the study is sound, reliable and valid, and that it is free from bias, thus making the final results trustworthy and of use to a larger population.

Methods  This article looks at five steps involved in a participatory evaluation process and the ways in which reliability and validity have been considered.

Results  Participatory studies may be different, but all have similar underlying principles as traditional quantitative and qualitative studies. Examples from fieldwork in Asia have been used to demonstrate how studies can be made credible, so that they have value, influence or the ability to encourage changes in thinking, while evaluating social development projects. At every stage, the role of the external evaluator remains crucial, and has to be that of a facilitator, encouraging participation from everyone.

Conclusion  Hence project evaluations using such a method must be clear in how to remove bias and ensure reliability and validity in all the stages of the evaluation, from planning to making recommendations. Imaginative and alternative strategies need to be developed to examine reliability and validity in the qualitative evaluation.
Bacterial production in the carbon flow of a central European stream, the Breitenbach
Authors: MARXSEN JÜRGEN
Published: September 2006

1. Over the last 30 years, many investigations have been performed on the dynamics of bacteria and organic matter in the Breitenbach, a first‐order stream in central Germany. The data now available allow a synthesis of the role of bacteria in the carbon budget, as an example of the general importance of bacteria in stream ecosystems.

2. Comparing measured and estimated inputs and outputs to the ecosystem, the organic matter budget of the Breitenbach is fairly balanced: 1.84 kg C m−2 year−1 (sum of inputs) versus 1.88 kg C m−2 year−1 (sum of outputs). No major missing link remains.

3. The basis of the food web in the Breitenbach is mainly allochthonous organic matter (dissolved and particulate 1.02 and 0.42 kg C m−2 year−1, respectively). Autochthonous gross primary production is 0.4 kg C m−2 year−1. Most of the organic matter leaves the stream via transport to the River Fulda (dissolved and particulate 0.74 and 0.34 kg C m−2 year−1, respectively), the rest by respiration (0.80 kg C m−2 year−1 or 43% of total outputs).

4. Bacteria constitute an important part (36%) of heterotrophic biomass (average: 0.004 kg m−2 bacterial C of 0.011 kg m−2 total heterotrophic C). Bacteria also account for the major fraction (71%) of heterotrophic production: 0.20 of 0.28 kg C m−2 year−1 total heterotrophic production. Bacterial production in the Breitenbach is similar in magnitude to the estimate of photoautotrophic net primary production: both approximately 0.20 kg C m−2 year−1.

5. Protozoa, the main consumers of bacteria in the Breitenbach, consume approximately one‐third of bacterial production (0.07 kg C m−2 year−1). Small metazoa (meiofauna, <0.5 mm) play a lesser role in the consumption of bacteria, consuming <0.01 kg bacterial C m−2 year−1. Larger metazoa (macrofauna, >0.5 mm) consume approximately 10% of bacterial production. Although this is a considerable amount of the carbon resources needed by the macrofauna (0.02 kg C m−2 year−1 of bacterial production versus 0.06 kg C m−2 year−1 macrofauna production plus respiration), the carbon demand of the macrofaunal community is met to a larger extent by particulate organic matter than by bacteria.

6. Bacteria are the main decomposers in the Breitenbach. They account for 78% of heterotrophic respiration (0.47 of 0.60 kg C m−2 year−1) and 59% of total respiration (0.47 of 0.80 kg C m−2 year−1).
Physiological constraints on contest behaviour
Authors: BRIFFA M. , SNEDDON L. U.
Published: September 2006

Contests may involve injurious fighting, other types of direct physical aggression and communication. They occur over ownership access to mates and other resources that may increase an individual's attractiveness and its chance of survival. Traits that enhance resource holding potential may be the result of sexual selection, natural selection or a combination of both.

Agonistic behaviours are expected to be demanding to perform and costly in terms of changes in physiological state. The ability to meet the physiological costs may determine contest outcomes and constrain the intensity of agonistic activities.

The energetic costs have been investigated in a broad range of taxa using a variety of techniques. They include the mobilization of energy reserves, but a key cost in several taxa appears to be limited anaerobic capacity and subsequent accumulation of lactic acid. Androgens, stress hormones and neurohormones have also been shown to constrain fighting behaviour. However, due to key differences in the endocrine systems of vertebrates and invertebrates, the effects of hormones are far less consistent across taxa than in the case of metabolites.

Physiological constraints on fighting may vary according to their importance relative to circumstantial costs, the time‐scale over which they exert their effects, their effects on different roles and their causal links with behaviour. Incorporating these factors into theoretical studies of contest behaviour may give further insights of how the costs of fighting influence agonistic behaviour.
Climate change and bird phenology: a long‐term study in the Iberian Peninsula
Authors: GORDO OSCAR , SANZ JUAN JOSÉ
Published: September 2006

Many studies in recent years have demonstrated long‐term temporal trends in biological parameters that can only be explained by climate change. Bird phenology has received great attention, as it studies one of the most conspicuous, popular, and easily observable phenomena in nature. There are many studies of long‐term changes in spring arrival dates, most of which concur with earlier records from the last few decades. However, few data are available for autumn departures or length of stays. Furthermore, existing data offer an equivocal picture. In this study, we analysed a huge database of about 44 000 records for five trans‐Saharan bird species (Ciconia ciconia, Cuculus canorus, Apus apus, Hirundo rustica and Luscinia megarhynchos). Data were collected from over 1300 sites around Spain during the period 1944–2004. Common spring arrival patterns were found in all species. Spring arrival dates have tended to advance since the mid‐1970s. Current dates are similar to those from the 1940s (except for C. ciconia). Thus, the advance of spring migration over the last three decades could be seen as a return to the initial timing of arrival dates, after abnormally delayed arrivals during the 1970s. A strong negative relationship with temperature in Spain at arrival time was observed in all species. A negative relationship with the Sahel Index (a measurement of precipitation in the African Sahel area during the rainy season) for the previous year was also found in C. canorus, A. apus and H. rustica. Regarding autumn departures, all species showed common interdecadal fluctuations, but only H. rustica is leaving earlier Spain at present. All species departed earlier in years that had higher temperatures during their reproductive period. However, only for H. rustica the relation between Spanish temperatures at departure time and the last sightings of individuals was significant. A heterogeneous temporal response for the length of stay was also found: C. ciconia increased, A. apus did not change and H. rustica decreased its stay. This is the first study, based on an extensive bird phenology observational network covering a large region, that shows the most complete and thorough analysis available for the Mediterranean region.
Pathology of fungal infections of the central nervous system: 17 years' experience from Southern India
Authors: Sundaram C , Umabala P , Laxmi V , Purohit A K , Prasad V S S V , Panigrahi M , Sahu B P , Sarathi M V , Kaul S , Borghain R , Meena A K , Jayalakshmi S S , Suvarna A , Mohandas S , Murthy J M K
Published: September 2006

Aims:  To describe the pathology of central nervous system (CNS) fungal infections with particular reference to India.

Methods and results:  This was a retrospective study from 1988 to 2004 constituting 130 cases. The diagnosis was based on morphology of biopsy/autopsy material. These included aspergillosis (n = 73), zygomycosis (n = 40), cryptococcosis (n = 2), rhodotorulosis (n = 1), candidiasis (n = 5), maduramycosis (n = 1), pheohyphomycosis (n = 3) and mixed infections (n = 5). Predisposing risk factors were present in 49 (38%) patients only. The majority of the patients were immunocompetent. The commonest risk factor was diabetes mellitus, the commonest route of infection was from a contiguous site and the commonest pathology was granuloma. Culture positivity was seen in only 31%.

Conclusion:  Environmental factors in tropical countries such as India play a significant role in the pathogenesis of CNS fungal infections.
The contributions of age and sex to variation in common tern population growth rate
Authors: EZARD T.H.G. , BECKER P.H. , COULSON T.
Published: September 2006

The decomposition of population growth rate into contributions from different demographic rates has many applications, ranging from evolutionary biology to conservation and management. Demographic rates with low variance may be pivotal for population persistence, but variable rates can have a dramatic influence on population growth rate.

In this study, the mean and variance in population growth rate (λ) is decomposed into contributions from different ages and demographic rates using prospective and retrospective matrix analyses for male and female components of an increasing common tern (Sterna hirundo) population.

Three main results emerged: (1) subadult return was highly influential in prospective and retrospective analyses; (2) different age‐classes made different contributions to variation in λ: older age classes consistently produced offspring whereas young adults performed well only in high quality years; and (3) demographic rate covariation explained a significant proportion of variation in both sexes. A large contribution to λ did not imply a large contribution to its variation.

This decomposition strengthens the argument that the relationship between variation in demographic rates and variation in λ is complex. Understanding this relationship and its consequences for population persistence and evolutionary change demands closer examination of the lives, and deaths, of the individuals within populations within species.
Connecting variation in vegetation and stream flow: the role of geomorphic context in vegetation response to large floods along boreal rivers
Authors: RENÖFÄLT BIRGITTA MALM , MERRITT DAVID M. , NILSSON CHRISTER
Published: September 2006

Flooding governs riparian plant diversity along boreal rivers but the ecological role of extreme floods is only partly understood. We studied the dynamics of riparian plant composition and richness in the free‐flowing Vindel River in northern Sweden, and the importance of reach type in sustaining high species richness.

We conducted three surveys of riparian plant species richness over a period of two decades. The first and last of these surveys were conducted 1–3 years after significant flooding and the second was carried out after a period of more moderate flooding.

Our results suggest that extreme floods reduce riparian plant species richness in tranquil (slow‐flowing) reaches but that a subsequent period of less extreme flood events facilitates recovery. Tranquil river reaches were also more prone to invasion by ruderal species following major floods. Species richness in turbulent reaches (rapids and runs) remained constant during all surveys. One possible explanation for this pattern is that tranquil reaches become more anoxic during floods because they have more fine‐grade soils with lower hydraulic conductivity than turbulent reaches. Anoxic conditions may cause stress and plant death, opening up space for colonization. Turbulent reaches maintain a better oxygenation in the root zone of plants through high groundwater turnover, reducing negative effects of prolonged floods.

The fact that turbulent reaches preserved species richness regardless of flood magnitude suggests that they are important for the resistance of riparian ecosystems to prolonged inundation. In contrast, tranquil reaches, with a higher water‐holding capacity, might instead maintain their species richness during drought periods.

Synthesis and applications. Our findings highlight the importance of spatial and temporal variation in riverine plant species richness and composition. To conserve these habitats at a landscape scale, a full range of reach types is necessary to allow for recovery in reaches where species richness has declined. To maintain healthy riparian zones, river managers should focus restoration efforts on interactions between hydrology, geomorphology and biota.
Spatial structure of roe deer populations: towards defining management units at a landscape scale
Authors: ZANNÈSE AUDREY , MORELLET NICOLAS , TARGHETTA CHIARA , COULON AURÉLIE , FUSER SIMONETTA , HEWISON A. J. MARK , RAMANZIN MAURIZIO
Published: September 2006

A crucial question in wildlife management concerns the definition of ecologically meaningful management units. Management action needs to be co‐ordinated at the appropriate spatial scale. There are few practical tools for delimiting pertinent management units for large mammals such as ungulates.

Previous work has favoured a molecular approach to determine genetically distinct units, but this may be too costly for routine management. In addition, recent studies have revealed fine‐scale heterogeneity in population dynamics of free‐ranging ungulates in relation to environmental variability.

We combined spatial analysis of environmental heterogeneity (vegetation cover, topography and climate), animal morphology (jaw length) and genetic structure (microsatellites) to define biologically meaningful population units for roe deer Capreolus capreolus in the Belluno province, north‐eastern Italy. Jaw length is a sensitive measure of density‐dependence and a good proxy for spatial and temporal variation in roe deer population growth.

Spatial analysis of environmental variables suggested that the study area should be divided into two, or possibly four, biogeographical regions in relation to variation in altitude and habitat type. There was significant spatial variability in jaw length across the province that clustered into two main regions (with shorter jaws in the north compared with the south), which matched the previously defined biogeographical regions. This spatial structuring was also supported by microsatellite analysis, which revealed two genetically distinct populations, one in the north and one in the south.

Synthesis and applications. A multiparameter approach, combining environmental information with data on indices of density‐dependence such as jaw length, could be extremely useful for defining ecologically meaningful management units. Indeed, monitoring spatial and temporal variation in jaw length could provide deer managers with a simple way to index population structure and fluctuations in time and space.
Identification of Bacillus cereus internalin and other candidate virulence genes specifically induced during oral infection in insects
Authors: Fedhila Sinda , Daou Nadine , Lereclus Didier , Nielsen‐LeRoux Christina
Published: September 2006

Bacillus cereus is an opportunistic bacterium frequently associated with food‐borne infections causing gastroenteritis. We developed an in vivo expression technology (IVET), with an insect host, for identification of the B. cereus genes specifically expressed during infection. This IVET‐based approach uses site‐specific recombinase TnpI to identify transient promoter activation. We constructed a genomic library of B. cereus ATCC14579 by cloning DNA fragments upstream from tnpI. The library was screened in vivo by oral infection of the insect Galleria mellonella. We selected 100 clones from dead larvae. Sequencing of the inserts followed by a second screen for specific in vivo induction led to the identification of 20 in vivo‐induced genes (ivi genes). They belonged to several different functional classes: regulation, metabolism, DNA repair and replication, cell division, transport, virulence and adaptation. A strongly induced gene, ivi29, was further analysed. It encodes an internalin‐like protein with four distinct domains: an N‐terminal signal peptide for export, a NEAT domain thought to be involved in iron transport, a leucine‐rich repeat domain that may interact with host cells, and a C‐terminal SLH domain presumably binding the protein to the peptidoglycan. As suggested by a Fur box in the promoter, transcriptional analysis showed ivi29 expression to be repressed by iron, suggesting that expression was induced in vivo due to iron deprivation in the host. This iron‐regulated, leucine‐rich surface protein was designated IlsA. Disruption of ilsA reduced the virulence of the bacteria to the insect larvae indicating its role in the overall pathogenesis of B. cereus.
Reduced minicolumns in the frontal cortex of patients with autism
Authors: Buxhoeveden D. P. , Semendeferi K. , Buckwalter J. , Schenker N. , Switzer R. , Courchesne E.
Published: September 2006

Cell minicolumns were shown to be narrower in frontal regions in brains of autistic patients compared with controls. This was not found in primary visual cortex. Within the frontal cortex, dorsal and orbital regions displayed the greatest differences while the mesial region showed the least change. We also found that minicolumns in the brain of a 3‐year‐old autistic child were indistinguishable from those of the autistic adult in two of three frontal regions, in contrast to the control brains. This may have been due to the small size of the columns in the adult autistic brain rather than to an accelerated development. The presence of narrower minicolumns supports the theory that there is an abnormal increase in the number of ontogenetic column units produced in some regions of the autistic brain during corticoneurogenesis.
Carbohydrate metabolism and fruit quality are affected in frost‐exposed Valencia orange fruit
Authors: Falcone Ferreyra María Lorena , Perotti Valeria , Figueroa Carlos M. , Garrán Sergio , Anderson Perla C. , Vázquez Daniel , Iglesias Alberto A. , Podestá Florencio E.
Published: September 2006

Exposure of citrus fruit to frost often results in the development of freeze injury during their maturation in planta. This work was aimed to analyze changes in the biochemistry and enzymology of carbohydrate metabolism in freeze‐injured orange fruit (Citrus sinensis var. Valencia late) and the involvement of oxidative stress in frost damage. The activities of pyrophosphate‐dependent phosphofructokinase, phosphoenolpyruvate carboxylase and several fermentative enzymes increased in frost‐exposed (FE) fruit, while NADP‐malic enzyme and the mitochondrial isoform of NAD‐malate dehydrogenase showed a reduction in their activities. Western blot analysis indicated a correlation between activity levels and protein content. Respiration rate in whole fruit was reduced by 40%, whereas the flavedo showed a more pronounced decline (53%). Volatile compound (i.e. ethanol and acetaldehyde) content was significantly higher in FE fruit than in control, as was that of l‐malate (three‐fold). Additionally, FE fruit showed a marked decrease in the maturity index (24%) because of a higher titratable acidity (39%). Evidence is presented that oxidative stress is involved in freeze‐induced damage of orange fruit, where oxidative damage to lipids and proteins, and a greater electrolyte leakage in the flavedo were also observed. The results suggest that freezing temperatures provoke a notable metabolic switch in citrus fruit toward a fermentative stage, resulting in low‐quality fruits.
A novel antigen‐specific capture assay for the detection of platelet antibodies and HPA‐1a phenotyping
Authors: Meyer O. , Agaylan A. , Bombard S. , Kiesewetter H. , Salama A.
Published: September 2006

Background and Objectives  The antigen‐specific assays currently used for the laboratory investigation of platelet antibodies and antigens are technically complex and cannot be used in most routine laboratories. Here, we describe a simple antigen‐specific capture assay (ASCA) for the detection of serum platelet antibodies and for human platelet antigen‐1a (HPA‐1a) phenotyping.

Materials and Methods  For the detection of platelet antibodies, platelets from healthy blood donors were incubated with biotinylated monoclonal antibodies to platelet glycoprotein complexes (GP), then solubilized and mixed with superparamagnetic streptavidin particles. Serum samples from patients with autoimmune thrombocytopenia (n = 39), from patients with platelet alloantibodies (6 HPA‐1a, 1 HPA‐2b, 1 HPA‐3a, 6 HPA‐5b), and from healthy blood donors (n = 70), were tested. All serum samples from the patients were investigated in parallel by the indirect monoclonal antibody‐specific immobilization of platelet antigen assay (MAIPA). For HPA‐1a phenotyping, superparamagnetic particles were coated with a monoclonal antibody to HPA‐1a and mixed with diluted whole blood samples from healthy blood donors (n = 139), who had previously been genotyped for platelet alloantigens.

Results  The indirect MAIPA detected autoantibodies in 18%, and the direct MAIPA in 50% of patients tested. In contrast, the new ASCA demonstrated positive results in 77% of patients. All tested alloantibodies reacted positive by the ASCA, and all serum samples from healthy blood donors were negative. The results of HPA‐1a phenotyping were in concordance with those of genotyping in all cases.

Conclusion  In our opinion, the ASCA is easy to perform and much more sensitive than the currently available antigen‐specific assays for the detection of platelet antibodies.
Chemoreception and the Assessment of Fighting Abilities in the Lizard Liolaemus monticola
Authors: Labra Antonieta
Published: September 2006

When an individual faces the risk of a conflict, its ability to make ‘correct’ decisions is crucial to its fitness. Research on decision making has focused mainly on visual and acoustic signals, while chemical signals have received much less attention, despite their relevance for many species. Chemosignals can be detected in the absence of the signaller and, in the context of fighting risk, this property confers the advantage that the receiver can avoid agonistic interactions or, if they are unavoidable, that it can prepare itself for the conflict. I studied the behaviour of males of the lizard Liolaemus monticola in the laboratory when they were confronted with chemosignals of a potential opponent. During this ‘pre‐confrontation’ stage, I tested the following predictions: (1) lizards can derive precise information from chemosignals of conspecifics, and use this to respond with precision to the perceived risk and (2) the best predictor of the receiver behaviour, and therefore the best predictor of the risk involved in the fight, is the relative fighting ability of opponents. As a measure of fighting ability, I used body size. ‘Intruders’ were placed in the terrarium of unfamiliar ‘residents’ during the absence of the latter, and their behaviours were recorded. Simple regressions were performed between the different behavioural variables and with the body sizes of intruder and resident, and with the relative difference in body sizes of opponents. The latter was the best predictor of intruder behaviour: it was negatively correlated with behaviours associated with activity (i.e. motion time), chemoexploration (i.e. number of tongue flicks) and behaviours associated with social interactions (i.e. head bobs). These results suggest that males can process information from chemosignals and decisions made during the ‘pre‐confrontation’ stage are based on the assessment of the relative fighting abilities (i.e. relative body size) of opponents.
Susceptibility of six pine species to Gremmeniella abietina isolates from Spain
Authors: Santamaría O. , Pando V. , Diez J. J.
Published: September 2006

Inoculation experiments were performed in order to evaluate the virulence of Gremmeniella abietina isolates from Spain on the main pine species planted in the Iberian Peninsula, as well as the influence of seedling age on this virulence. Two different experiments were carried out with four isolates of G. abietina from Spain. The greenhouse experiments consisted of seedling inoculations. One‐ and 2‐year‐old seedlings of the following five pine species were used: Pinus halepensis, Pinus pinea, Pinus pinaster, Pinus sylvestris and Pinus uncinata; also, 1‐year‐old seedlings of P. nigra were inoculated. The relative necrosis length (RNL) caused by the pathogen after 130 days was used as a response variable. The laboratory experiments were performed on 2‐ to 6‐year‐old internodes of the above pine species excluding P. uncinata. The necrosis length after 6 weeks of incubation was measured. The results have shown that all G. abietina isolates were pathogens on seedlings of these six pine species and seedlings of P. halepensis were consistently the most susceptible ones, although it is important to take into account that all the isolates used in the present work were isolated from P. halepensis, the only pine species in Spain where G. abietina has been recovered up to now. The susceptibility of the other pine species depended on the age of the seedlings.
Statistical analysis of the spatio‐temporal dynamics of rubber tree (Hevea brasiliensis) trunk phloem necrosis: no evidence of pathogen transmission
Authors: Peyrard N. , Pellegrin F. , Chadœuf J. , Nandris D.
Published: September 2006

Trunk phloem necrosis (TPN) of Hevea brasiliensis is an irreversible syndrome of the phloem that spreads from the collar towards the tapping cut. It is responsible for the cessation of latex production, the main constraint in rubber plantations worldwide. Numerous investigations have been undertaken to understand the mechanisms of this disease. The apparent linear spread of TPN supported the initial hypothesis of a biotic causal agent for TPN. However, previous and recent aetiological analyses remained inconclusive and the pathogen hypothesis is tending to be abandoned. In this paper we present a complementary statistical analysis of spatio‐temporal epidemiological data collected in a rubber plantation in Côte d'Ivoire. There, four study plots were surveyed each year from 2000 to 2003, with tree‐by‐tree disease assessment. In two plots, the tapping knife was systematically disinfected with sodium hypochlorite to stop any virus or viroid transmission. Based on permutation tests, our analysis confirmed the aetiological results: there was no evidence for spread by pathogen transmission. However, the spatial structure of the disease was clear. These results strengthen the current alternative scenario of a multi‐factor physiological disease caused by an accumulation of exogenous and endogenous stresses. Spatial heterogeneity of the risk factors probably results in the presence of areas of stress that can explain the spatial patterns observed among the TPN cases. The final contribution of this study was confirmation of the curative effect of sodium hypochlorite in the earliest stages of the disease, thus opening the way for control of this disease.
Traumatic resin canals as markers of infection events in Douglas‐fir roots infected with Armillaria root disease
Authors: Cruickshank M. G. , Lejour D. , Morrison D. J.
Published: September 2006

In response to an infection, traumatic resin canals (TRCs) are formed in the roots of many conifers, which may be used to determine the timing and sequence of infection events essential for epidemiological studies of root diseases. Juvenile Douglas‐fir (Pseudotsuga menziesii) tree roots at coastal and interior sites in British Columbia were wounded at various times of the year or were inoculated with an isolate of Armillaria ostoyae, and root sections were taken to determine the timing and extent of TRC formation. Naturally infected Douglas‐fir were also examined to determine the extent of the TRCs in infected and uninfected roots on infected trees and in the lower stem. Wounds made in March and October had poor or no TRC formation while the summer wounds responded strongly and were associated with resin soaking. Roots wounded in October did not respond until the following year in all trees except one. Trees produced TRCs and resin soaked tracheids at all times in response to the fungal inoculations. The most striking difference between wounding or fungal inoculation was the multiple bands of TRCs produced in response to the fungus. TRCs at natural A. ostoyae infections were found 92% of time in roots at the stem junction and 74% of the time in the stem at soil line. TRCs were produced in uninfected roots on infected trees but disappeared with increasing distance from the initiating lesion. TRCs can be used to time yearly and seasonal root infections when they can be traced from an identified lesion.
Acquisition and Transmission of two Begomoviruses by the B and a non‐B Biotype of Bemisia tabaci from Zhejiang, China
Authors: Jiu M. , Zhou X.‐P. , Liu S.‐S.
Published: September 2006

Acquisition and transmission was studied of Tomato yellow leaf curl China virus (TYLCCNV) and Tobacco curly shoot virus (TbCSV) by the B and a non‐B biotype (China‐ZHJ‐1) of Bemisia tabaci from Zhejiang, China. The frequency of TYLCCNV and TbCSV detection by PCR in whitefly adults increased with increasing length of feeding on virus‐infected plants. The virus DNA was detected by PCR in 40% of the B biotype adults tested after a period of 30 min access to infected plants and in all adults after a 12‐h period of access. All ZHJ‐1 adults acquired TYLCCNV and TbCSV after a 48‐h period of access to the virus‐infected plants. Viruliferous B and ZHJ‐1 adults retained TYLCCNV DNA for their entire life when placed on healthy cotton plants. Viruliferous ZHJ‐1 adults retained TbCSV DNA for their entire life when placed on healthy cotton plants but the B biotype adults did not. Transmission of TYLCCNV was achieved with one B or ZHJ‐1 adult per plant, and the probability of transmission reached 100% when the number of adults was increased to 10 per plant. The efficiency for TYLCCNV transmission to healthy plants by adults of both B and ZHJ‐1 was much higher than that for TbCSV.
Quantification of Fusarium culmorum in Wheat and Barley Tissues Using Real‐Time PCR in Comparison with DON Content
Authors: Leišová L. , Kučera L. , Chrpová J. , Sýkorová S. , Šíp V. , Ovesná J.
Published: September 2006

A real‐time polymerase chain reaction (PCR) assay was developed for the specific detection of Fusarium culmorum in infected seeds. Primers and TaqMan minor groove binder probe were derived from the sequences of a F. culmorum specific PCR product. The specificity of the assay was confirmed by test in seven Fusarium species and 21 non‐Fusarium fungal species. With serial dilutions of purified genomic DNA from F. culmorum isolate B as the template, the detection limit of the assay was found to be 0.9 pg of fungal genomic DNA per reaction. A significant correlation ( = 0.982) and collinearity was found between DNA concentration and Ct (cycle threshold) values of real‐time PCR assay with serial diluted DNAs extracted from three seed samples with different deoxynivalenol (DON) content. Eight barley and nine wheat varieties infected by F. culmorum isolate B were evaluated in 1 (barley samples) and in 4 years (wheat samples). The results of real‐time PCR analysis and enzyme‐linked immunosorbent assay testing for DON content were compared and a significant correlation was found for barley samples (r2 = 0.935). Concerning wheat we found rather complicated relationship between Ct values and DON contents influenced by environmental conditions of field trials. The real‐time PCR assay was found to be highly specific and sensitive. It could be used in phytopathological studies and praxis.
Influence of Sugar Beet Seed Treatment withPseudomonas fluorescensand Low Fungicide Doses on Infection withPythiumand Plant Yield and Quality
Authors: Kristek S. , Kristek A. , Guberac V. , Glavaš Tokić R. , Pavlovic H.
Published: September 2006

The effect of sugar beet seed inoculation with the bacteriumPseudomonas fluorescensand treatment with the fungicides Thiram 42‐S and Dithane S‐60 with and without seed inoculation aiming to control the root decay agentsPythium ultimumandPythium debarianumwas studied during a 2‐year trial on two soil types (Mollic Gleysols and Eutric Cambisols). The influence of the treatments on parameters of sugar beet yield and quality such as root yield, sugar content, sugar in molasses, sugar yield as well as percentage of the infected and decayed plants as a consequence of parasitic oomycete infestation will be described.
Effect of lake sediments of different trophic states on alkaline phosphatase activity
Authors: Jin Xiang Can , Wang Sheng Rui , Zhao Hai Chao , Bu Qing Yun , Chu Jian Zhou , Cui Ze , Zhou Xiao Ning , Wu Feng Chang
Published: September 2006

Samples of sediments, interstitial water and overlying water were collected monthly under temperature‐controlled conditions to determine the effects of sediment types on the alkaline phosphatase activity (APA) in lake systems. The relationship between the total alkaline phosphatase activity (TAPA) and soluble reactive phosphorus (SRP) concentration also was examined. The study results indicate the variations of TAPA in the overlying water, and the interstitial water in different layers from different sediments was similar over time. They were influenced not only by the phosphate concentrations, but also were correlated with submerged plant and phytoplankton biomass. The direct effects of the sediment types on the APA were not readily obvious. Although the higher APA in sediment was probably responsible for the enzymatic response to the characteristics of sediments, other factors (e.g. growth of submerged plants and phytoplankton) also should be considered. The peak of the maximum velocity of the enzyme reactions (Vmax) at deeper sediment layers suggests another stratum in which the enzymatically mediated phosphorus regeneration was active. This finding contributes to our understanding of phosphorus cycling in lake sediments.
Synthesis of a new conceptual model to facilitate management of ephemeral deflation basin lakes
Authors: Gawne Ben , Scholz Oliver
Published: September 2006

Ephemeral deflation basin lakes are widespread throughout arid and semiarid regions of the Murray–Darling Basin in Australia. Although they are diverse, productive habitats, the water resources development has generally caused significant declines in their ecological condition. Managers are currently trying to protect or restore these systems, however, without an adequate theoretical framework on which to base management decisions. This is because the existing conceptual models provide little insight into the effects of any component of the flow regime except flooding. This paper reviews the effects of flooding and drying on lakes, using the information and conclusions therein to propose a conceptual model that identifies five stages in the flooding and drying cycle. This conceptual model incorporates elements of the Flood Pulse Concept, Trophic Cascade models and the Geomorphic–Trophic model, as they apply to these highly variable water systems.
Nuclear division of the vegetative cells, conchosporangial cells and conchospores of Porphyra yezoensis (Bangiales, Rhodophyta)
Authors: Wang Juan , Dai Jixun , Zhang Yiting
Published: September 2006

To confirm the position and timing of meiosis in Porphyra yezoensis Ueda, the nuclear division of vegetative cells, conchosporangial cells and conchospores was observed. An improved staining method using modified carbol fuchsin was introduced to stain the chromosomes of Porphyra. Pit‐connections between conchosporangial cells also stained well with this method. Leptotene, zygotene, pachytene, diplotene, diakinesis, metaphase, anaphase and telophase were observed in the conchosporangial cells. During the germination of conchospores, no characteristics of meiosis I were found. No difference between the nuclear division of vegetative cells and that of conchospores was observed, and 2–3 days were needed for the first cell division both in vegetative cells and conchospores. Therefore, the cell division that occurs during conchospore germination is not meiosis I. Our results indicate that the prophase of meiosis I begins during the formation of conchosporangial branches, and metaphase I, anaphase I and telophase I take place during the maturation of conchosporangial branches. Then the three‐bivalent nucleate sporangia complete cell division to form two individual conchospores, each with one three‐univalent nucleus. The conchospores released from the sporangia are at meiotic interphase. Meiosis II occurs at the first nuclear division during conchospore germination, which is a possible explanation for the observation of mosaic thalli in mutant germlings of P. yezoensis. The mosaic thalli might also arise from gene conversion/post meiotic segregation events, comparable to those in Sordaria fimicola (Roberge ex Desm.) Ces. & De Not. and Neurospora crassa Shear & B.O. Dodge.
New records of three marine red algae from Japan
Authors: Masuda Michio , Tani Masaya , Kurihara Akira
Published: September 2006

Three species in the red algal order Ceramiales, Dasya longifila Masuda et Uwai (Dasyaceae), Endosiphonia horrida (C. Agardh) P. Silva (Rhodomelaceae) and Laurencia flexilis Setchell (Rhodomelaceae), are reported from Japan for the first time, and their morphological features are described along with taxonomic comments. Our findings point to the northernmost limit of geographic distribution of these species in the north‐western Pacific. Dasya longifila is characterized by small, sparsely corticated axes, long pseudolaterals in which intercalary cell divisions take place, and a small number of tetrasporangial stichidia and spermatangial branches per fertile pseudolateral. Endosiphonia horrida is characterized by frequently anastomosing branches that form a bush‐like tuft without a percurrent axis, inner cortical cells becoming the same length as the axial and periaxial cells, and luxuriously developed, unbranched trichoblasts. Laurencia flexilis is characterized by numerous cartilaginous rigid axes developing from a basal disc without creeping branches, the production of 4 periaxial cells per vegetative segment and the absence of longitudinally oriented secondary pit‐connections between contiguous superficial cortical cells.
Hippocampal CA3 pyramidal cells selectively innervate aspiny interneurons
Authors: Wittner Lucia , Henze Darrell A. , Záborszky László , Buzsáki György
Published: September 2006

The specific connectivity among principal cells and interneurons determines the flow of activity in neuronal networks. To elucidate the connections between hippocampal principal cells and various classes of interneurons, CA3 pyramidal cells were intracellularly labelled with biocytin in anaesthetized rats and the three‐dimensional distribution of their axon collaterals was reconstructed. The sections were double‐stained for substance P receptor (SPR)‐ or metabotropic glutamate receptor 1α (mGluR‐1α)‐immunoreactivity to investigate interneuron targets of the CA3 pyramidal cells. SPR‐containing interneurons represent a large portion of the GABAergic population, including spiny and aspiny classes. Axon terminals of CA3 pyramidal cells contacted SPR‐positive interneuron dendrites in the hilus and in all hippocampal strata in both CA3 and CA1 regions (7.16% of all boutons). The majority of axons formed single contacts (87.5%), but multiple contacts (up to six) on single target neurons were also found. CA3 pyramidal cell axon collaterals innervated several types of morphologically different aspiny SPR‐positive interneurons. In contrast, spiny SPR‐interneurons or mGluR‐1α‐positive interneurons in the hilus, CA3 and CA1 regions were rarely contacted by the filled pyramidal cells. These findings indicate a strong target selection of CA3 pyramidal cells favouring the activation of aspiny classes of interneurons.
Lack of localization of 5‐HT6 receptors on cholinergic neurons: implication of multiple neurotransmitter systems in 5‐HT6 receptor‐mediated acetylcholine release
Authors: Marcos Beatriz , Gil‐Bea Francisco J. , Hirst Warren D. , García‐Alloza Mónica , Ramírez María J.
Published: September 2006

The involvement of the cholinergic system in learning and memory together with the cognitive enhancing properties of 5‐HT6 receptor antagonists led us to study the relationship between 5‐HT6 receptors and cholinergic neurotransmission. A selective cholinergic lesion, induced by injection of the immunotoxin 192‐IgG‐Saporin into the nucleus basalis magnocellularis, failed to alter the density of 5‐HT6 receptor mRNA or protein expression in the deafferentated frontal cortex, suggesting that 5‐HT6 receptors are not located on cholinergic neurons. The 5‐HT6 receptor antagonist SB‐357134 (0.001–1 µm) induced a concentration‐dependant K+‐evoked [3H]acetylcholine (ACh) release in vitro in rat cortical and striatal slices, which was blocked by tetrodotoxin. SB‐357134, up to 1 µm, stimulated glutamate release in cortical and striatal slices. In the cortex, riluzole (1 µm) blocked the SB‐357134‐induced K+‐stimulated [3H]ACh release, and simultaneous administration of MK‐801 (1 µm) and SB‐357134 (0.05 µm) elicited an increase in K+‐evoked ACh release. In the striatum, SB‐357134, 1 µm, decreased dopamine release, and the increase in K+‐evoked [3H]ACh release induced by 5‐HT6 receptor blockade was reversed by the D1 receptor antagonist, SCH23390 (1 µm). In both the frontal cortex and striatum, bicuculline, 1 µm, showed no effect on SB‐357134‐evoked [3H]ACh. These results are discussed in terms of neurochemical mechanisms involved in 5‐HT6 receptor functions.
Early‐phase of learning enhances communication between brain hemispheres
Authors: Cybulska‐Klosowicz Anita , Kossut Malgorzata
Published: September 2006

In the somatosensory system, inputs from one side of the body are only transmitted to the contralateral primary somatosensory cortex, but both sides of the body representation can interact via interhemispheric connections. These interactions depend on the behavioural requirements of the animal and its level of arousal. During the process of learning, alertness and attention may modify the responsiveness of neuronal pathways. We functionally mapped the brains of mice by using [14C]2‐deoxyglucose (2DG) autoradiography during the first and the third session of a classical conditioning paradigm, involving whiskers stimulation on one side of the muzzle paired with an aversive or appetitive unconditioned stimulus. During the first pairing session, an increased 2DG uptake was seen in the barrel cortex of both hemispheres, independently of the type of applied unconditioned stimulus. In the third session of the sensory pairing, activation of the barrel cortex was solely contralateral, as expected after unilateral whisker stimulation. Thus, sensory stimulation directed to one cerebral hemisphere during the initial stages of Pavlovian conditioning activates the primary sensory area in both hemispheres. These results suggest that during the early phase of conditioning, when alertness is presumably strongest, the interhemispheric interactions are enhanced.