bluuebunny/crossref_metadata_2025_split huggingface dataset:
Conifer defence against insects: microarray gene expression profiling of Sitka spruce (Picea sitchensis) induced by mechanical wounding or feeding by spruce budworms (Choristoneura occidentalis) or white pine weevils (Pissodes strobi ) reveals large‐scale changes of the host transcriptome
Authors: RALPH STEVEN G. , YUEH HESTHER , FRIEDMANN MICHAEL , AESCHLIMAN DANA , ZEZNIK JEFFREY A. , NELSON COLLEEN C. , BUTTERFIELD YARON S. N. , KIRKPATRICK ROBERT , LIU JERRY , JONES STEVEN J. M. , MARRA MARCO A. , DOUGLAS CARL J. , RITLAND KERMIT , BOHLMANN JÖRG 
Published: June 2006

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

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

ABSTRACTWe used dedicated magnetic resonance imaging (MRI) equipment and methods to study phloem and xylem transport in large potted plants. Quantitative flow profiles were obtained on a per‐pixel basis, giving parameter maps of velocity, flow‐conducting area and volume flow (flux). The diurnal xylem and phloem flow dynamics in poplar, castor bean, tomato and tobacco were compared. In poplar, clear diurnal differences in phloem flow profile were found, but phloem flux remained constant. In tomato, only small diurnal differences in flow profile were observed. In castor bean and tobacco, phloem flow remained unchanged. In all plants, xylem flow profiles showed large diurnal variation. Decreases in xylem flux were accompanied by a decrease in velocity and flow‐conducting area. The diurnal changes in flow‐conducting area of phloem and xylem could not be explained by pressure‐dependent elastic changes in conduit diameter. The phloem to xylem flux ratio reflects what fraction of xylem water is used for phloem transport (Münch’s counterflow). This ratio was large at night for poplar (0.19), castor bean (0.37) and tobacco (0.55), but low in tomato (0.04). The differences in phloem flow velocity between the four species, as well as within a diurnal cycle, were remarkably small (0.25–0.40 mm s−1). We hypothesize that upper and lower bounds for phloem flow velocity may exist: when phloem flow velocity is too high, parietal organelles may be stripped away from sieve tube walls; when sap flow is too slow or is highly variable, phloem‐borne signalling could become unpredictable.
Potential of environmental models to predict meningitis epidemics in Africa
Authors: Thomson Madeleine C. , Molesworth Anna M. , Djingarey Mamoudou H. , Yameogo K. R. , Belanger Francois , Cuevas Luis E. 
Published: June 2006

SummaryObjectives  Meningococcal meningitis is a major public health problem in Africa. This report explores the potential for climate/environmental models to predict the probability of occurrence of meningitis epidemics.Methods  Time series of meningitis cases by month and district were obtained for Burkina Faso, Niger, Mali and Togo (536 district‐years). Environmental information (1989–1999) for the continent [soil and land‐cover type, aerosol index, vegetation greenness (NDVI), cold cloud duration (CCD) and rainfall] was used to develop models to predict the incidence of meningitis. Meningitis incidence, dust, rainfall, NDVI and CCD were analysed as anomalies (mean minus observed value). The models were developed using univariate and stepwise multi‐variate linear regression.Results  Anomalies in annual meningitis incidence at district level were related to monthly climate anomalies. Significant relationships were found for both estimates of rainfall and dust in the pre‐, post‐ and epidemic season. While present in all land‐cover classes these relationships were strongest in savannah areas.Conclusions  Predicting epidemics of meningitis could be feasible. To fully develop this potential, we require (a) a better understanding of the epidemiological and environmental phenomena underpinning epidemics and how satellite derived climate proxies reflect conditions on the ground and (b) more extensive epidemiological and environmental datasets. Climate forecasting tools capable of predicting climate variables 3–6 months in advance of an epidemic would increase the lead‐time available for control strategies. Our increased capacity for data processing; the recent improvements in meningitis surveillance in preparation for the distribution of the impending conjugate vaccines and the development of other early warning systems for epidemic diseases in Africa, favours the creation of these models.
Can a comprehensive voucher programme prompt changes in doctors’ knowledge, attitudes and practices related to sexual and reproductive health care for adolescents? A case study from Latin America
Authors: Meuwissen Liesbeth E. , Gorter Anna C. , Kester Arnold D. M. , Knottnerus J. A. 
Published: June 2006

SummaryObjectives  To evaluate whether participation in a competitive voucher programme designed to improve access to and quality of sexual and reproductive health care (SRH‐care), prompted changes in doctors’ knowledge, attitudes and practices.Methods  The voucher programme provided free access to SRH‐care for adolescents. Doctors received training and guidelines on how to deal with adolescents, a treatment protocol, and financial incentives for each adolescent attended. To evaluate the impact of the intervention on doctors, nearly all participating doctors (n = 37) were interviewed before the intervention and 23 were interviewed after the intervention. Answers were grouped in subthemes and scores compared using nonparametric methods.Results  The initial interviews disclosed deficiencies in doctors’ knowledge, attitudes and practices relating to adolescent SRH‐issues. Gender and age of the doctor were not associated with the initial scores. Comparing scores from before and after the intervention revealed significant increases in doctors’ knowledge of contraceptives (P = 0.003) and sexually transmittable infections (P < 0.001); barriers to contraceptive use significantly diminished (P < 0.001 and P = 0.003); and some attitudinal changes were observed (0 = 0.046 and P = 0.11). Doctors became more aware of the need to improve their communication skills and were positive about the programme.Conclusions  This study confirmed provider related barriers that adolescents in Nicaragua may face and reinforces the importance of focusing on the quality of care and strengthening doctors’ training. Participation in the voucher programme resulted in increased knowledge, improved practices and, to a lesser extent, in changed attitudes. A competitive voucher programme with technical support for the participating doctors can be a promising strategy to prompt change.
Hospital and community surveys reveal the severe public health problem and socio‐economic impact of human echinococcosis in Ningxia Hui Autonomous Region, China
Authors: Yang Y. R. , Williams G. M. , Craig P. S. , Sun T. , Yang S. K. , Cheng L. , Vuitton D. A. , Giraudoux P. , Li X. , Hu S. , Liu X. , Pan X. , McManus D. P. 
Published: June 2006

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

SummaryObjective and methods  Fever tends to start at a lower level of parasitemia in Plasmodium vivax or ovale than in P. falciparum malaria, but hyperparasitemia and complications are more likely to occur in P. falciparum malaria. Therefore, we compared the relationship between parasitemia and host response parameters before therapy in 97 patients with P. faciparum malaria (18 with complications), and 28 with P. vivax or ovale malaria.Results  In both types of malaria, parasitemia correlated with blood levels of tumour necrosis factor alpha (TNF‐alpha), lactate dehydrogenase (LDH), Thrombin–antithrombin III (TAT) and elastase, and these parameters were higher in P. falciparum malaria than in P. vivax or ovale malaria. In contrast, the ratios of TNF‐alpha, TAT, elastase, and LDH per parasitized erythrocyte were higher in P. vivax or ovale malaria than in uncomplicated P. falciparum malaria. They were lowest in complicated disease. Multivariate regression analysis confirmed that parasitemia did not affect these differences.Conclusion  The host response may reach full strength at lower parasitemia in Plasmodium vivax or ovale, than in P. falciparum malaria. With hyperparasitemia in P. falciparum malaria, the host response seems to be unable to control parasite multiplication.
Process evaluation of the Senegal‐Community Nutrition Project: an adequacy assessment of a large scale urban project
Authors: Gartner Agnès , Maire Bernard , Kameli Yves , Traissac Pierre , Delpeuch Francis 
Published: June 2006

SummaryObjective  Although essential for understanding the reasons for success or failure of large scale nutritional interventions, process evaluation results are rarely reported. Our objective was to assess whether the process output objectives of the Community Nutrition Project (CNP) in Senegal, West Africa, were adequately met.Methods  An adequacy assessment study based on monitoring data for individuals collected during the CNP was used to assess ‘fidelity’, ‘extent’ and ‘reach’ of participants recruitment and of the services provided. The CNP provided underweight or nutritionally at risk 6‐ to 35‐month‐old children in poor districts with monthly growth monitoring and promotion and a weekly food supplementation for 6 month periods, provided that mothers attended weekly nutrition education sessions. An exhaustive sample of the participating children (n = 4084) in Diourbel was used for evaluation over the first 2 years.Results  At recruitment, only 66% of children were underweight (vs. 90% expected) varying with the CNP center and cohort, and the child's sex and age. Attendance at growth monitoring reached expected levels (93%vs. 90%) whereas numbers of food supplements distributed and education sessions attended were lower than expected (45%vs. 90% and 62%vs. 80%, respectively). At the end of follow‐up, 61% of underweight children recovered vs. 80% expected.Conclusions  Because of CNP design for underweight diagnosis and bias in the targeting process, respect for selection criteria was low and consequently under coverage and leakage occurred. Besides a globally satisfactory process, wide discrepancies were observed between CNP centres concerning the utilization and effectiveness of services. This formative evaluation helped diagnose weaknesses; ongoing feedback enabled the CNP to improve targeting and supply of supplements. It also informed a larger impact evaluation. Some generalizable lessons for similar programmes have been highlighted.
Resistance to sulphadrug‐based antifolate therapy in malaria: are we looking in the right place?
Authors: Platteeuw J. J. 
Published: June 2006

SummarySulphadrug treatment failure in malaria therapy cannot solely be ascribed to the build‐up of genetic resistance within the parasitic genome. Although numerous in vitro studies have tried to determine the exact genetic markers that could predict treatment outcome in patients, this research has not been conclusive. Sulphadrugs work by competitive inhibition with pABA at one point of the pathway to de novo folate synthesis. However, evidence suggests that the malaria parasite is capable of overcoming this competitive inhibition by switching over to other metabolic pathways, like direct folate salvage from a person's bloodstream. In other words, increased folic acid administration, via diet or supplementation, may have reduced the effectiveness of sulphadrugs more than genetic mutations. Although in vitro studies are valuable for understanding disease mechanisms, we should not forget that the human being is infinitely more complex than any laboratory model.
The unity that does not exist – a review of A. Burt & R. Trivers 2006: Genes in Conflict
Authors: Helanterä H. 
Published: June 2006

Abstract
Organisms harbour several genetic elements with the potential to act selfishly, and thus undermine the fitness of the organism as a whole. In their book ‘Genes in conflict’, Austin Burt and Robert Trivers thoroughly review evolution and molecular biology of such selfish genetics elements, and set them in a kin selection framework. In this review I set their views in a larger multi-level selection framework, and consider potential problems in the study of selfish genetics elements.
Variation in Plant Substrates and its Consequences for Insect Vibrational Communication
Authors: Cocroft R. B. , Shugart H. J. , Konrad K. T. , Tibbs K. 
Published: June 2006

AbstractMany insects and other arthropods communicate using plant‐borne vibrational signals. Vibration transmission along plant stems imposes a frequency filter on signals, and may cause signal degradation from reflected waves. Furthermore, different plant species and plant parts can differ in their transmission properties. This variability in the communication channel may constrain the reliability of signals, with important consequences for the evolution of vibrational communication systems, as well as for researchers studying signal variation at an individual, population, or species level. In this study we estimate the magnitude of substrate‐related variation in the mate advertisement signals of a treehopper (Hemiptera: Membracidae: Umbonia crassicornis). We used laser vibrometry to record the signals produced by 25 adult males on two different plant species, one host and one non‐host. We recorded male signals on two plants per species; within each plant, signals were recorded simultaneously at two distances. We measured three spectral characteristics (dominant frequency, relative amplitude of the signals’ high and low frequency components, frequency at the end of the signal) and two temporal characteristics (signal duration and click repetition rate). Spectral characteristics were influenced by the distance at which the signal was recorded, and this influence varied among plant species and individuals. Temporal characteristics were less influenced, although signal length was influenced by distance, an effect that varied among individual plants. Overall, the magnitude of the effects was small. Furthermore, there was significant within‐individual repeatability of almost all signal traits across different plant substrates. Signal characteristics were thus reliably associated with individuals, even when they signaled on different plants.
Looking for Food: Molecular Neuroethology of Invertebrate Feeding Behavior
Authors: Tan Eunice J. , Tang Bor L. 
Published: June 2006

AbstractThe assignment of complex behavior of animals to the function of specific genes has seen significant advances in the past decade. The advent of modern tools of genetics and genomics permitted analyses that revealed a good number of neural system enriched genes whose products modulate, and whose polymorphism qualitatively or quantitatively influenced invertebrate feeding behavior. The most prominent of these genes are orthologues offoraging (for)and the neuropeptide Y (NPY)/NPY receptor. The former encodes a cyclic‐GMP‐dependent protein kinase, which functional genetics have been characterized inDrosophila melanogaster,Apis melliferaandCaenorhabditis elegans. Allelic variations and changes in the expression of the above genes could influence the initiation of particular feeding behaviors or related social phenotype. These genes have provided the first molecular insights towards feeding behavior in invertebrates. Besides detailed investigations into the neural pathways involved and mechanisms of function of the gene products, parallel studies in other animal models is imperative to understand ecological drivers of animal feeding behavior.
Sex reversal in medaka treated in vitro with 17α‐methyldihydrotestosterone during oocyte maturation
Authors: Iwamatsu Takashi , Kobayashi Hirokuni , Yamashita Masakane 
Published: June 2006

Using the S‐rR strain of the medaka Oryzias latipes, we examined the effect of a non‐aromatizable androgen on sex determination. Intrafollicular immature oocytes isolated before breakdown of the germinal vesicle were incubated in the presence of 17α‐methyldihydrotestosterone (MDHT) for about 10 h during their maturational period. At the end of incubation, mature oocytes were rinsed and then artificially inseminated in regular saline. The fertilized eggs were then allowed to develop in tap water, and the fry were reared on a regular powdered diet until adulthood. Sex reversal of female to male was observed in a manner dependent on the dose of MDHT. In the solvent control group in which intrafollicular oocytes were matured in medium containing no exogenous androgen, no sex reversal was observed. The present finding, that the sex of medakas can be reversed by a single in vitro exposure of immature oocytes to androgen during the preovulatory period, suggests the existence in the oocyte of a sex determinant sensitive to sex steroids. This method for controlling the sex of eggs before fertilization may establish sex‐determined eggs as potent material for investigating the mechanism of sex determination in the medaka.