bluuebunny/crossref_metadata_2025_split huggingface dataset:
PCR‐based detection of Xanthomonas campestris pathovars in Brassica seed
Authors: Berg T. , Tesoriero L. , Hailstones D. L. 
Published: June 2005

Xanthomonas campestris is a seedborne bacterium that causes black rot of crucifers. Substantial crop losses may result from the rapid spread of the bacteria under favourable conditions, especially those occurring during seedling production. A PCR‐based method has been developed for the rapid and sensitive detection of the pathovars of X. campestris that affect crucifers. Primers were designed to specifically amplify a 619 bp fragment of the hrpF gene from X. campestris. Amplification products were not detected from other Xanthomonas species, or from other pathogenic or epiphytic bacteria occurring on these plants. To avoid false‐negative results arising from the presence of amplification inhibitors in plant extracts, primers targeting a 360 bp section of the internal transcribed spacer (ITS) region from Brassica spp. were included in a multiplex PCR. The assay readily detected X. campestris pv. campestris infections in diseased plants and from bacterial colonies isolated on growth media, and was more sensitive and specific than traditional plating methods and a commercially available ELISA. A seed‐washing protocol was optimized to allow the detection of a single artificially infected seed among 10 000 healthy seeds using the multiplex PCR.
Adjustment of soil‐surface pH and comparison with conventional fungicide treatments for control of lettuce drop (Sclerotinia minor)
Authors: Wilson C. R. , DeLittle J. A. , Wong J. A. L. , Schupp P. J. , Gibson L. J. 
Published: June 2005

The use of soil‐surface applications of finely powdered calcium hydroxide (Ca(OH)2) to inhibit Sclerotinia minor sclerotial germination and infection at the collar region of lettuce plants is described. In the laboratory, a pH > 8·0 reduced sclerotial germination of the three S. minor isolates tested. In the glasshouse, surface applications of 2–10 t Ca(OH)2 ha−1 raised the pH of the top 1–2 cm of a duplex sandy loam soil above 8·5 for at least 8 weeks without affecting soil pH within the transplant root zone. There was a linear relationship between the rate of Ca(OH)2 applied and disease control, with complete disease suppression at 10 t Ca(OH)2 ha−1. In field trials on two soil types (duplex sandy loam, pH 6·0; and red ferrosol, pH 6·9), a rate of 2·5 t Ca(OH)2 ha−1, maintained soil‐surface pH above 8·5 for 1–3 weeks and provided up to 58% reduction in lettuce drop. Application of polyvinyl alcohol (a soil‐conditioning polymer) over the Ca(OH)2 layer appeared to reduce Ca(OH)2 loss by wind, but did not improve retention of raised soil‐surface pH or disease suppression. Ca(OH)2 treatment gave similar disease control to the industry standard treatment of a procymidone‐based fungicide seedling drench. A combined treatment of Ca(OH)2 and fungicide drench gave greater control than either individual treatment, and equivalent control to fungicide drench and three procymidone foliar sprays, offering integrated management options. The use of soil‐surface‐applied Ca(OH)2 with fungicides, rotation and drip irrigation offers an opportunity for enhanced and sustainable control of lettuce drop.
Upregulation of Bcl‐2 at the Foetal—Maternal Interface from Mice Undergoing Abortion
Authors: Bertoja A. Zambon , Zenclussen M. L. , Wollenberg I. , Paeschke S. , Sollwedel A. , Gerlof K. , Woiciechowsky C. , Volk H.‐D. , Zenclussen A. C. 
Published: June 2005

AbstractSeveral burning questions remain unanswered in pregnancy‐related research. Pro‐ and anti‐inflammatory cytokines orchestrate an intriguing interaction leading either to the development of a normal individual or to its rejection. Augmented Th1 cytokines' production is involved in immunological rejection of the foetus. Excessive production of Th1 cytokines, particularly of tumour necrosis factor (TNF)‐α, also triggers apoptosis. Thus, in the present work we investigated the incidence of apoptosis in a well‐known experimental model of Th1‐induced abortion, characterized by increased local TNF‐α levels. Apoptosis of lymphocytes as well as their Th1 and Th2 cytokine production were analysed by flow cytometry. TNF‐α mRNA levels were additionally analysed by real time reverse transcription‐polymerase chain reaction (RT‐PCR) in placental and decidual samples. Total placental apoptosis activity was investigated by measuring caspase‐3 activity and by TdT‐mediated dUTP nick end label staining. Immunohistochemistry, Western blot and real time RT‐PCR were used to localize and quantify several anti‐ and pro‐apoptotic molecules at the foetal–maternal interface. Despite elevated Th1 levels at the foetal–maternal interface, mice undergoing abortion presented comparable apoptotic rates. Interestingly, we found a significant upregulation of the anti‐apoptotic Bcl‐2 protein at the foetal–maternal interface from abortion‐prone mice, while no changes could be observed for pro‐apoptotic molecules. In the light of our results, we conclude that there is no evidence of increased apoptosis in mice undergoing immunological abortion in spite of elevated TNF‐α levels. This is probably due to a selective upregulation of anti‐apoptotic pathways (i.e. Bcl‐2) at the foetal–maternal interface as a compensatory and/or protective mechanism.
Bioactivation of Latent Transforming Growth Factor β1 by Mycobacterium tuberculosis in Human Mononuclear Phagocytes
Authors: Aung H. , Wu M. , Johnson J. L. , Hirsch C. S. , Toossi Z. 
Published: June 2005

AbstractBiologically active transforming growth factor beta 1 (TGFβ1) has been identified at sites of Mycobacterium tuberculosis (MTB) infection in the lung; however, the underlying mechanism(s) for its activation is not clear. Here using an enzyme‐linked immunospot assay for TGFβ1, we show that human blood monocytes (MN) and alveolar macrophages (AM) produce bioactive TGFβ1 upon stimulation by MTB. However, only MTB‐stimulated MN increased TGFβ1 production on a per cell basis. The frequency of TGFβ1‐producing MN was reduced by an inhibitor of plasmin, bdellin, indicating a role for plasmin pathways in the bioactivation of cytokine. The expression of urokinase plasminogen activator receptor (uPAR) mRNA and both surface and soluble uPAR (CD87) was increased in MTB‐activated MN. However, antibody neutralization of uPAR suppressed bioactive TGFβ1 in MN alone. Thus, the more immature MN, which are continuously recruited to the lung during tuberculosis (TB), have a higher capacity to bioactivate TGFβ1 by expression of components of the plasmin pathway. Excess production and bioactivation of TGFβ1 at sites of MTB infection may undermine host immune responses during TB.
Immunoglobulin‐A antibodies in Upper Airway Secretions may Inhibit Intranasal Influenza Virus Replication in Mice but not Protect Against Clinical Illness
Authors: Bižanov G. , Janakova L. , Knapstad S.‐E. , Karlstad T. , Bakke H. , Haugen I. L. , Haugan A. , Samdal H. H. , Haneberg B. 
Published: June 2005

AbstractMice immunized intranasally with a formalin‐inactivated A/PR/8/34 (H1N1) influenza whole virus vaccine adjuvanted with cholera toxin, outer membrane vesicles from group B meningococci or formalin‐inactivated whole cell Bordetella pertussis were protected against replication of the homologous virus in the nasal cavity. Only some mice were protected against clinical illness measured as weight loss and lowered body temperature. All mice immunized subcutaneously with one‐tenth the intranasal vaccine dose without adjuvant were protected against clinical illness but not against local mucosal viral replication. Replicating virus was primarily found in animals with low concentrations of immunoglobulin (Ig)‐A antibodies in saliva regardless of concentrations of IgG antibodies in serum. Clinical illness was seen only in those with low serum antibodies regardless of antibody levels in saliva. Nonreplicating nasal vaccines may not be sufficiently protective unless they also have a substantial influence on systemic immunity.
Submarine‐spring controlled calcification and growth of large Rivularia bioherms, Late Pleistocene (MIS 5e), Gulf of Corinth, Greece
Authors: PORTMAN CLIVE , ANDREWS JULIAN E. , ROWE PETER J. , LEEDER MICHAEL R. , HOOGEWERFF JURIAN 
Published: June 2005

AbstractThe cyanobacterium Rivularia haematites has calcified to form unusually large (up to 10 m high) bioherms in the Pleistocene Gulf of Corinth. Today R. haematites calcifies only in freshwater environments but these Gulf of Corinth bioherms have a brackish affinity, limited areal extent, and occur within marine deposits. Field relations and preliminary U‐series dating suggest a marine isotope stage (MIS) 5e age for the bioherms. This age is compatible with published MIS 5e ages for corals in the marine sediments above the bioherms and is consistent with their current elevation based on average uplift rates. Bioherm growth during MIS 5e constrains their formation during a time of near sea‐level highstand when the Gulf of Corinth was marine. Growth cavities in the bioherms are encrusted by brackish tolerant coralline algae. Field mapping of the MIS 5e highstand palaeoshoreline shows the bioherms grew in water <16 m deep. Mg contents of the bioherm calcites, and associated coralline algal skeletons, are both much lower than expected for marine MIS 5e carbonates. They are best explained if the calcites precipitated from brackish fluids with Mg/Ca ratios below 2, implying at least 60% input of freshwater with low Mg/Ca ratio. Sr isotopes confirm a strong input of groundwater that had partially equilibrated with Mesozoic limestones. The limited areal extent of the bioherms and their close association with karstified fault scarps suggest that they formed in shallow sea water where freshwater submarine springs delivered CaCO3 saturated water that promoted rapid calcification of cyanobacteria. Rapid calcification and strong degassing of CO2 from the spring water resulted in disequilibrium stable isotope compositions for the calcites.
ARL1, a LOB‐domain protein required for adventitious root formation in rice
Authors: Liu Hongjia , Wang Shoufeng , Yu Xiaobo , Yu Jie , He Xiaowei , Zhang Shelong , Shou Huixia , Wu Ping 
Published: June 2005

SummaryAdventitious roots constitute the bulk of the fibrous root system in cereals. Compared with the current understanding of shoot development, knowledge of the molecular mechanisms of development of the adventitious roots of cereals is limited. We have isolated and characterized a novel gene controlling the initiation of adventitious root primordia in rice (Oryza sativa L.). The gene, designated Adventitious rootless1 (ARL1), encodes a protein with a LATERAL ORGAN BOUNDARIES (LOB) domain. It is expressed in lateral and adventitious root primordia, tiller primordia, vascular tissues, scutellum, and young pedicels. ARL1 is a nuclear protein and can form homodimers. ARL1 is an auxin‐ and ethylene‐responsive gene, and the expression pattern of ARL1 in roots parallels auxin distribution. Our findings suggest that ARL1 is an auxin‐responsive factor involved in auxin‐mediated cell dedifferentiation, and that it promotes the initial cell division in the pericycle cells adjacent to the peripheral vascular cylinder in the stem.
Canine serum immunoreactivity toM. pachydermatis in vitrois influenced by the phase of yeast growth
Authors: HABIBAH A. , CATCHPOLE B. , BOND R. 
Published: June 2005

Abstract In western immunoblotting studies of canine sera usingMalassezia pachydermatisextracts, the reported patterns of immunoreactivity vary between different laboratories. Because the duration of culture influences the antigenic composition of lipid‐dependentMalasseziaspp. when probed with human sera, we investigated whether thein vitrogrowth phase ofM. pachydermatisinfluences immunoreactivity using canine sera. Extracts ofM. pachydermatisCBS 1879 grown in Sabouraud's liquid medium at 37 °C for 2, 4, 6, 8 and 10 days were prepared by mechanical disruption, centrifugation, dialysis and lyophilization. Yeast growth phase was assessed by sequential colony counts and optical density measurements. Patterns of IgG immunoreactivity in high (n = 3) and low (n = 3) titre sera were compared using extracts prepared at each time point by sodium dodecyl sulphate polyacrylamide gel electrophoresis and western immunoblotting. Protein bands of 62 and 49 kDa were recognized by all sera, and 98 and 68 kDa bands were recognized by five sera. Proteins of 188, 66, 58, 57, 38, 28 and 17 kDa were only recognized by high titre sera. All high titre sera used recognized more bands in exponential phase (d2) extracts when compared with decline phase (d8‐d10) extracts, and two of these sera showed most bands in stationary phase (d4‐d6) extracts. Bands of 62 and 57 kDa were primarily detected in exponential and early stationary phase extracts. There is variation in antigenic expression in different growth phases ofM. pachydermatis, which might explain discrepancies between previous laboratory studies of canine immunity to this yeast.
Long‐term potentiation in the rat dentate gyrus is associated with enhanced Arc/Arg3.1 protein expression in spines, dendrites and glia
Authors: Rodríguez J. J. , Davies H. A. , Silva A. T. , De Souza I. E. J. , Peddie C. J. , Colyer F. M. , Lancashire C. L. , Fine A. , Errington M. L. , Bliss T. V. P. , Stewart M. G. 
Published: June 2005

AbstractElectron microscopic immunocytochemical methods were used to determine the localization, subcellular distribution and expression of activity‐regulated cytoskeletal protein (Arc/Arg3.1) in dentate gyrus after unilateral induction of long‐term potentiation (LTP) in the perforant pathway of anaesthetized rats. At 2 h post‐induction, immunoreaction product was visible in the dentate gyrus in both the granule cell and molecular layers. Arc expression was higher in the potentiated than the unstimulated contralateral hemisphere. Single‐section electron microscopy analysis in unstimulated tissue and in tissue prepared 2 and 4 h after LTP induction showed Arc immunoreactivity (Arc‐IR) in dendrites, dendritic spines and glia. Arc‐IR was associated with synaptic and non‐synaptic plasma membrane apposed to axon terminals and with cytoplasmic organelles, including the cytoskeleton. Arc‐IR was also present in neuronal perikarya and there was occasional labelling of nuclei and axons. At 2 h post‐LTP induction, there were significant increases in Arc‐IR within the granule cell and molecular layers of the dentate gyrus and particularly within the middle molecular layer relative to the inner and outer molecular layers. This increase in Arc expression 2 h after LTP induction was blocked by the N‐methyl‐d‐aspartate receptor antagonist (RS)‐3‐2‐carboxypiperazin‐4‐yl‐propyl‐1‐phosphonic acid. In animals killed 4 h after LTP induction, Arc expression had declined and differences between the potentiated and unpotentiated hemispheres were no longer significant. Our data provide ultrastructural evidence for a transient LTP‐associated increase in the expression of Arc protein in the middle molecular layer of the dentate gyrus, with preferential targeting to dendrites, dendritic spines and glia.
Changes in cutaneous and body temperature during and after conditioned fear to context in the rat
Authors: Vianna Daniel M. L. , Carrive Pascal 
Published: June 2005

AbstractInfrared thermography was used to image changes in cutaneous temperature during a conditioned fear response to context. Changes in heart rate, arterial pressure, activity and body (i.p.) temperature were recorded at the same time by radio‐telemetry, in addition to freezing immobility. A marked drop in tail and paws temperature (−5.3 and −7.5 °C, respectively, down to room temperature), which lasted for the entire duration of the response (30 min), was observed in fear‐conditioned rats. In sham‐conditioned rats, the drop was on average half the magnitude and duration. In contrast, temperature of the eye, head and back increased (between + 0.8 and + 1.5 °C), with no difference between the two groups of rats. There was a similar increase in body temperature although it was slightly higher and delayed in the fear‐conditioned animals. Finally, ending of the fear response was associated with a gradual decrease in body temperature and a rebound increase in the temperature of the tail (+ 3.3 °C above baseline). This study shows that fear, and to some extent arousal, evokes a strong cutaneous vasoconstriction that is restricted to the tail and paws. This regionally specific reduction in blood flow may be part of a preparatory response to a possible fight and flight to reduce blood loss in the most exposed parts of the rat's body in case of injury. The data also show that the tail is the main part of the body used for dissipating internal heat accumulated during fear once the animal has returned to a safe environment.
Different basal levels of CaMKII phosphorylated at Thr286/287 at nociceptive and low‐threshold primary afferent synapses
Authors: Larsson Max , Broman Jonas 
Published: June 2005

AbstractPostsynaptic autophosphorylation of Ca2+/calmodulin‐dependent protein kinase II (CaMKII) at Thr286/287 is crucial for the induction of long‐term potentiation at many glutamatergic synapses, and has also been implicated in the persistence of synaptic potentiation. However, the availability of CaMKII phosphorylated at Thr286/287 at individual glutamatergic synapses in vivo is unclear. We used post‐embedding immunogold labelling to quantitatively analyse the ultrastructural localization of CaMKII phosphorylated at Thr286/287 (pCaMKII) at synapses formed by presumed nociceptive and low‐threshold mechanosensitive primary afferent nerve endings in laminae I–IV of rat spinal cord. Immunogold labelling was enriched in the postsynaptic densities of such synapses, consistent with observations in pre‐embedding immunoperoxidase‐stained dorsal horn. Presynaptic axoplasm also exhibited sparse immunogold labelling, in peptidergic terminals partly associated with dense core vesicles. Analysis of single or serial pCaMKII‐immunolabelled sections indicated that the large majority of synapses formed either by presumed peptidergic or non‐peptidergic nociceptive primary afferent terminals in laminae I–II of the spinal cord, or by presumed low‐threshold mechanosensitive primary afferent terminals in laminae IIi–IV, contained pCaMKII in their postsynaptic density. However, the postsynaptic levels of pCaMKII immunolabelling at low‐threshold primary afferent synapses were only ∼ 50% of those at nociceptive synapses. These results suggest that constitutively autophosphorylated CaMKII in the postsynaptic density is a common characteristic of glutamatergic synapses, thus potentially contributing to maintenance of synaptic efficacy. Furthermore, pCaMKII appears to be differentially regulated between high‐ and low‐threshold primary afferent synapses, possibly reflecting different susceptibility to synaptic plasticity between these afferent pathways.
Use of non‐limiting substrates to increase size; a generic strategy to simultaneously optimize uptake and minimize predation in pelagic osmotrophs?
Authors: Thingstad T. Frede , Øvreås Lise , Egge Jorun K. , Løvdal Trond , Heldal Mikal 
Published: June 2005

AbstractCoexistence of two organisms competing for the same nutrient is possible if one is an ‘uptake’, and the other a ‘predation defence’ specialist. In pelagic food webs this principle has been linked to cell size. Small osmotroph cells, with their high surface : volume ratio, have been argued to be uptake specialists, while larger osmotrophs avoiding the intense grazing pressure from small protozoan predators might represent ‘predation defence’ specialists. This may seem like an obligatory trade‐off situation that necessitates a choice of either being small or being large, and thus being potentially dominant in oligotrophic or in eutrophic environments, respectively. However, in a more precise form, the theory for nutrient diffusion states that it is the ‘surface : cell requirement of limiting element’ ratio, rather than the ‘surface : volume’ ratio, that is important. The distinction is crucial, since it opens up the possibility of there being life strategies that use a non‐limiting element to increase size. Hypothesized to maximize uptake and predator defence simultaneously, such strategies should be particularly successful. We suggest that this strategy is exploited by osmotrophs with different size and physiology, such as heterotrophic bacteria, unicellular cyanobacteria and diatoms. Since the strategy implies a shift in organism stoichiometry, the biogeochemical implications are strong, illustrating the tight relationships between physical micro‐scale processes, organism life strategies, biodiversity, food web structure, and biogeochemistry.
Models of cooperation based on the Prisoner's Dilemma and the Snowdrift game
Authors: Doebeli Michael , Hauert Christoph 
Published: June 2005

AbstractUnderstanding the mechanisms that can lead to the evolution of cooperation through natural selection is a core problem in biology. Among the various attempts at constructing a theory of cooperation, game theory has played a central role. Here, we review models of cooperation that are based on two simple games: the Prisoner's Dilemma, and the Snowdrift game. Both games are two‐person games with two strategies, to cooperate and to defect, and both games are social dilemmas. In social dilemmas, cooperation is prone to exploitation by defectors, and the average payoff in populations at evolutionary equilibrium is lower than it would be in populations consisting of only cooperators. The difference between the games is that cooperation is not maintained in the Prisoner's Dilemma, but persists in the Snowdrift game at an intermediate frequency. As a consequence, insights gained from studying extensions of the two games differ substantially. We review the most salient results obtained from extensions such as iteration, spatial structure, continuously variable cooperative investments, and multi‐person interactions. Bridging the gap between theoretical and empirical research is one of the main challenges for future studies of cooperation, and we conclude by pointing out a number of promising natural systems in which the theory can be tested experimentally.
Experience‐induced preference for oviposition repellents derived from a non‐host plant by a specialist herbivore
Authors: Liu Shu‐Sheng , Li Yue‐Hong , Liu Yin‐quan , Zalucki Myron P. 
Published: June 2005

AbstractForaging adults of phytophagous insects are attracted by host‐plant volatiles and supposedly repelled by volatiles from non‐host plants. In behavioural control of pest insects, chemicals derived from non‐host plants applied to crops are expected to repel searching adults and thereby reduce egg laying. How experience by searching adults of non‐host volatiles affects their subsequent searching and oviposition behaviour has been rarely tested. In laboratory experiments, we examined the effect of experience of a non‐host‐plant extract on the oviposition behaviour of the diamondback moth (DBM), Plutella xylostella, a specialist herbivore of cruciferous plants. Naive ovipositing DBM females were repelled by an extract of dried leaves of Chrysanthemum morifolium, a non‐host plant of DBM, but experienced females were not repelled. Instead they were attracted by host plants treated with the non‐host‐plant extract and laid a higher proportion of eggs on treated than on untreated host plants. Such behavioural changes induced by experience could lead to host‐plant range expansion in phytophagous insects and play an important role in determining outcome for pest management of some behavioural manipulation methods.