bluuebunny/crossref_metadata_2025_split huggingface dataset:
Origin and evolution of endemic plants of the Bonin (Ogasawara) Islands
Authors: Ito Motomi 
Published: December 2007

AbstractThe Bonin Islands are typical oceanic islands, located at the western part of the North Pacific Ocean and approximately 1,000 km south of mainland Japan. This archipelago consists of about 20 small islands. Although floristic diversity is low due to the small area and limited environmental diversity, the Bonin Islands harbor unique endemic flora as in other well‐known oceanic islands. This paper presents a brief summary of the results obtained from recent studies on the endemic flora of the Bonin Islands. The results are reviewed in relation to the four stages of the evolution of endemic flora in the oceanic islands; migration, establishment, enlargement and diversification. The ancestors of the flora originated mostly from tropical and subtropical Southeast Asia or mainland Japan by rare events of long distance dispersal. The proportion of bird‐dispersed species is relatively high as for other oceanic islands. Genetic data sets obtained from allozyme variation in some endemic species suggest that migration occurred several million years ago and genetic diversity is correlated with current population size. At the time of establishment, self‐compatible plants are expected to have an advantage. However, the percentage of dioecious plants is relatively high. This is partly due to evolutionary changes from hermaphroditic ancestors to dioecy which occurred in two genera in the Bonin Islands. In addition, there are some examples of evolutionary changes from herbaceous ancestors to woody endemics. Adaptive radiation is found in some genera, although the number of congeneric endemic species is less than five. Studies of allozyme variation in Pittosporum, Symplocos and Crepidiastrum showed that genetic identity is generally very high between congeneric species in spite of their distinct morphologies. This result suggests that divergence of these species occurred rather recently and distinct morphological differences are based on a limited number of genetic changes.
Hybridization and speciation in the carabid beetles of the subgenusOhomopterus(Coleoptera, Carabidae, genusCarabus)
Authors: Kubota Kôhei , Sota Teiji 
Published: December 2007

AbstractNatural hybridization among wingless carabid beetles of the subgenusOhomopterus(Carabidae, genusCarabus)is reviewed, and its significance in the evolution of this subgenus discussed. Natural hybridization occurs between parapatric species of similar size. Two case studies of natural hybridization suggest that natural hybridization could have affected the evolution of this subgenus in different ways. When there is a large difference in genital morphology between hybridizing species, interspecific copulation often results in genital injuries that causes mortality of copulating individuals, and hence reduces the fitness of hybridizing individuals greatly. In such a case, hybridization may be effective in maintaining the parapatric distribution of the two species, and in the long term, may promote reinforcement selection for traits which are effective in prezygotic reproductive isolation. When the morphological difference in genitalia is not so large as to cause genital injury, a hybrid population may be established at the intermediate zone between two parental species, provided that the immigration rates of the two species into the intermediate zone are small. Thus, natural hybridization may have contributed to both divergence and reticulate evolution in this subgenus.
Stabilization effects of spatial aggregation of vectors in plant disease systems
Authors: Yamamura Kohji 
Published: December 2007

AbstractStabilization effects of spatial aggregation of vectors were examined in insect‐borne plant disease systems by constructing a model that describes the yearly dynamics of rice stripe virus disease transmitted by the small brown planthopper Laodelphax striatellus (Fallén). Two transmission paths between vectors were considered: vertical transmission from parents through eggs, and horizontal transmission from infected plants by acquisition feeding. In this model, a paddy field was divided into quadrats and horizontal transmission was assumed to occur within each quadrat. A negative binomial distribution was used to describe the frequency distribution of vectors per quadrat. The parameters of the model were estimated using field data collected in Ibaraki Prefecture, Japan. The model showed that (1) the disease cannot invade into an epidemiological system if the mean crowding of vectors is less than a critical value, (2) the proportion of infected vectors is maintained at about 30% irrespective of the vector density if vectors are highly aggregated, and (3) the proportion of infected plants is maintained at a low level irrespective of the vector density if vectors are highly aggregated. It was also shown that these stabilization effects of aggregation in this epidemiological system come from a mechanism that is common to other systems such as single‐species systems and competition systems.
Polymorphic fundatrices in thimbleberry aphid — ecology and maintenance
Authors: Gilbert Neil , Raworth David A. 
Published: December 2007

AbstractThe thimbleberry aphid, Masonaphis maxima (Mason) lives on patches of plants that support 3,4 or 5 generations depending on site and weather. The life cycle requires sexual females and males to produce overwintering eggs. The eggs hatch in the spring to produce the first ‘fundatrix’ generation; subsequent generations are produced parthenogenically. Males and other morphs are produced by wingless virginoparae, but sexual females are produced by ‘gynoparae’, a winged morph that is specialized to produce only sexual females. The fundatrices have no indication of the number of generations that the plants will support in the current year. There are two fundatrix types that coexist in different ratios depending on the number of generations supported by the patch the previous year. One type produces sexual females in generations 3 and 5, and males in generations 4 and 5; the other type produces sexual females in generations 4 and 5, and males in generations 3, 4 and 5. The dimorphism adapts the aphid to its heterogeneous and somewhat unpredictable environment. The role of sex in the maintenance of the dimorphism is discussed. This is the first report of fundatrix polymorphism and consequent differential sex expression in aphids.
Anthropogenic, ecological and genetic factors in extinction and conservation
Authors: Lande Russell 
Published: December 2007

AbstractAnthropogenic factors constitute the primary deterministic causes of species declines, endangerment and extinction: land development, overexploitation, species translocations and introductions, and pollution. The primary anthropogenic factors produce ecological and genetic effects contributing to extinction risk. Ecological factors include environmental stochasticity, random catastrophes, and metapopulation dynamics (local extinction and colonization) that are intensified by habitat destruction and fragmentation. Genetic factors include hybridization with nonadapted gene pools, and selective breeding and harvesting. In small populations stochastic factors are especially important, including the ecological factors of Allee effect, edge effects, and demographic stochasticity, and the genetic factors of inbreeding depression, loss of genetic variability, and fixation of new deleterious mutations. All factors affecting extinction risk are expressed, and can be evaluated, through their operation on population dynamics.
Extinction risk assessment of declining wild populations: The case of the southern Bluefin Tuna
Authors: Matsuda Hiroyuki , Takenaka Yasuto , Yahara Tetsukazu , Uozumi Yuji 
Published: December 2007

AbstractWe estimate the extinction probability of a large and decreasing population, the southern bluefin tuna. This tuna was listed as critically endangered by the World Conservation Union (IUCN) in 1996. However, the absolute population size is still large and the extinction probability within the next half century is negligible if the recent population decline rate does not increase in the future. IUCN's criterion with respect to the population decline rate should be linked to the absolute population size, if this is estimated. Several methods estimating the probability of extinction conclude that the southern bluefin tuna population will be below 500 mature individuals within the next 100 years and may be listed as vulnerable. These analyses suggest that extinction risk assessment is useful for management action for taxa that still have large population and are rapidly decreasing.
Theoretical aspects of extinction by inbreeding depression
Authors: Tanaka Yoshinari 
Published: December 2007

AbstractPopulational extinction due to inbreeding depression is analyzed with simple population genetic and population ecological models. Two alternative genetic mechanisms of inbreeding depression, i.e. recessive deleterious genes and overdominant genes, are assumed in separate analyses in order to examine their relative importance. With both mechanisms the population size and the coefficient of inbreeding are maintained at stable equilibria if there is no non‐genetic demographic disturbance or stress. With a certain amount of demographic disturbance the population declines rapidly due to interaction between the decrease of population size and the increase of inbreeding coefficient. Such rapid extinction occurs with both genetic mechanisms. However, in the case of overdominant genes extinction happens only if the equilibrium population size is small and the selection coefficient is large such that segregation load is large. In nature, extinction due to overdominant genes is considered to be much less likely than extinction due to recessive deleterious genes.
Evolutionary character changes and population responses in an insect host‐parasitoid experimental system
Authors: Tuda Midori 
Published: December 2007

AbstractIn an insect host (the cowpea weevil Callosobruchus maculatus)‐ parasitoid Heterospilus prosopidis) experimental system, the population densities of the component species oscillated for the first 20 generations and then abruptly stabilized as the parasitoid density decreased. Examination of the host and parasitoid after the 40th generation in the long‐term experiment showed that (1) host larvae exhibited contest‐type competition (killing other larvae inhabiting the same bean), in contrast to the founder population being scramble‐type competitors and (2) the parasitoid attack rate on the host did not change. There was also an evolutionary trade‐off between body size and the rates of larval survival and development, suggesting a cost of contest competition on larval survivorship and development. I tested model predictions (Tuda and Iwasa 1998) that (1) host equilibrium population size should gradually decrease as the proportion of the contest type increases and that (2) random attacks of the parasitoid on the host should reduce the rate of increase in proportion of the contest type, and the effect should become manifest especially during the first 20 generations. Two of three host‐only replicates showed significant decrease in population sizes. Although the density of emerging adults per bean did not differ between replicates of the host‐only and host‐parasitoid systems, comparison of the host body size between them on day 270 (at the 13th generation) showed that the host was more contest‐type in the host‐only system than in the host‐parasitoid system, as the model predicted, and later on day 650 the effect of the parasitoid had disappeared.
Genetic changes of life history and behavioral traits during mass‐rearing in the melon Fly, Bactrocera cucurbitae (Diptera: Tephritidae)
Authors: Miyatake Takahisa 
Published: December 2007

AbstractQuantitative genetic studies for life history and behavioral traits are important in quality control for insect mass‐rearing programs. Firstly, a brief history of quality control in mass‐reared insects is described. Next, the differentiation of many traits of wild and mass‐reared melon flies, Bactrocera cucurbitae, in Okinawa is reviewed, and the factors which have caused variation in these traits are considered. As artificial selection pressures are thought to be more important than inbreeding depression and genetic drift in the mass‐reared strain of the Okinawan melon fly, two artificial selection experiments were conducted to evaluate genetic variations and genetic correlations among life history and behavioral traits. These are divergent selections for age at reproduction and for developmental period. The genetic relationship among 5 traits, i.e. longevity, age at reproduction, developmental period, circadian period, and time of mating was clarified and discussed in relation to genetic changes of traits during the mass‐rearing. The results suggest that the genetic trade‐off relationships between traits should be taken into account in mass‐rearing programs.
Brief report: Expressive and collaborative relationship processes in observations of adolescents’ interactions with parents and romantic partners
Authors: Madsen Stephanie D. , Andrew Collins W. 
Published: December 2007

ABSTRACTThis study examines observations of participants (N=64) interacting with family members at age 13 and romantic partners at age 20–21. Scales capturing expressive processes and collaborative processes were used to test and find support for the differential prediction that family collaborative processes at age 13 would predict both expressive processes and collaborative processes with romantic partners at age 20–21, whereas expressive processes at age 13 would predict only concurrent collaborative processes. Results suggest that continuity in relationship functioning is more differentiated than is commonly expected.
Drotaverine hydrochloride versus hyoscine‐N‐butylbromide in augmentation of labor
Authors: Gupta Bindiya , Nellore Vimala , Mittal Suneeta 
Published: December 2007

AbstractObjectives: To study and compare the efficacy and side effects of drotaverine hydrochloride and hyoscine‐N‐butylbromide in the augmentation of labor. Methods: A prospective randomized trial of 150 women in active labor included 50 women given drotaverine (group 1), 50 women given hyoscine‐N‐butylbromide (group 2), and 50 women given no medication (group 3). Duration of labor, rate of cervical dilation, mode of delivery, side effects, and neonatal outcome were compared among the groups. Results: The mean duration of the active phase of labor was 4.48 ± 2.26 h, 3.9 ± 2.42 h, and 3.6 ± 2.07 h in groups 1, 2, and 3, respectively. The mean rate of cervical dilation was 2.6 cm/h, 2.4 cm/h, and 2.5 cm/h, respectively. The differences were not statistically significant. There was no difference in the duration of the second and third stages of labor. No adverse maternal or fetal outcomes were noted. Conclusion: Drotaverine hydrochloride and hyoscine‐N‐butylbromide do not have a role in augmentation of labor.
Ovarian suppression treatment prior to in‐vitro fertilization and embryo transfer in Chinese women with stage III or IV endometriosis
Authors: Ma Caihong , Qiao Jie , Liu Ping , Chen Guian 
Published: December 2007

AbstractObjectiveTo evaluate the efficacy of a 2‐month treatment with a gonadotropin‐releasing hormone (GnRH) agonist prior to in‐vitro fertilization in Chinese women with moderate or severe endometriosis.MethodsA study of 162 women surgically diagnosed as having moderate or severe endometriosis. Pituitary down‐regulation was achieved with injections of a GnRH agonist prior to the IVF procedures either for 7 to 10 days in the mid‐luteal phase (group 1 [standard protocol], 97 cycles in total), or for 2 months (group 2, 55 cycles), or 3 months (group 3, 75 cycles).ResultsWomen pretreated with a GnRH agonist for 2 or 3 months required significantly higher doses of gonadotropin for ovarian stimulation (P < 0.001), and for a longer time, than those treated with the standard long protocol (P < 0.05). The number of oocytes and good embryos was lower in group 3 than in groups 1 or 2 (P < 0.05). The implantation rate was significantly higher in group 2 than in group 1 (P < 0.02).ConclusionA 2‐month treatment with a GnRH agonist prior to IVF produced a trend toward an increase in the implantation rate in a group of Chinese women with stages III and IV endometriosis.
Putative promoter regions of miRNA genes involved in evolutionarily conserved regulatory systems among vertebrates
Authors: Fujita Shuji , Iba Hideo 
Published: December 2007

Abstract
Motivation: Just as transcription factors, miRNA genes modulate global patterns of gene expression during differentiation, metabolic activation, stimulus response and also carcinogenesis. However, little is currently known how the miRNA gene expression itself is regulated owing to lack of basic information of their gene structure. Global prediction of promoter regions of miRNA genes would allow us to explore the mechanisms underlying gene-regulatory mechanisms involving these miRNAs.
Results: We speculate that if specific miRNA molecules are involved in evolutionarily conserved regulatory systems in vertebrates, this would entail a high level of conservation of the promoter of miRNA gene as well as the miRNA molecule. By our current screening of putative promoter regions of miRNA genes (miPPRs) on this base, we identified 59 miPPRs that would direct production of 79 miRNAs. We present both biochemical and bioinformatical verifications of these putative promoters.
Contact: iba@ims.u-tokyo.ac.jp
Supplementary information: Supplementary data are available at Bioinformatics online.
UV-B Signaling Pathways with Different Fluence-Rate Response Profiles Are Distinguished in Mature Arabidopsis Leaf Tissue by Requirement for UVR8, HY5, and HYH
Authors: Brown Bobby A. , Jenkins Gareth I. 
Published: December 2007

Abstract
UV-B signaling is an important but poorly understood aspect of light responsiveness in plants. Arabidopsis (Arabidopsis thaliana) UV RESISTANCE LOCUS8 (UVR8) is a recently identified UV-B-specific signaling component that regulates UV-protective responses. Using the uvr8 mutant, we defined genetically distinct UVR8-dependent and UVR8-independent pathways that stimulate different sets of genes in mature Arabidopsis leaf tissue. Both pathways operate at 1 μmol m−2 s−1 UV-B and above, but the UVR8-dependent pathway is able to stimulate UV-protective genes even in response to 0.1 μmol m−2 s−1 UV-B. Both pathways function in mutants lacking phytochromes, cryptochromes, or phototropins. Genes encoding the ELONGATED HYPOCOTYL5 (HY5) and HY5 HOMOLOG (HYH) transcription factors are induced at low UV-B fluence rates (0.1 μmol m−2 s−1). Experiments with hy5 and hyh mutants reveal that both these factors mediate responses of the UVR8-dependent pathway, acting with partial or complete redundancy to stimulate expression of particular genes. Furthermore, evidence is presented that all UVR8 pathway genes are likely to be regulated by HY5/HYH and that these transcription factors do not mediate UV-B responses independent of UVR8. Finally, we highlight the functions of HY5 and HYH in UV protection and show that HY5 plays the more critical role. This research provides evidence that, in UV-B signaling, UVR8, HY5, and HYH act together in a photoregulatory pathway and demonstrates a new role for HYH in UV-B responses.
Core Genome Responses Involved in Acclimation to High Temperature
Authors: Larkindale Jane , Vierling Elizabeth 
Published: December 2007

AbstractPlants can acclimate rapidly to environmental conditions, including high temperatures. To identify molecular events important for acquired thermotolerance, we compared viability and transcript profiles of Arabidopsis thaliana treated to severe heat stress (45°C) without acclimation or following two different acclimation treatments. Notably, a gradual increase to 45°C (22°C to 45°C over 6 h) led to higher survival and to more and higher-fold transcript changes than a step-wise acclimation (90 min at 38°C plus 120 min at 22°C before 45°C). There were significant differences in the total spectrum of transcript changes in the two treatments, but core components of heat acclimation were apparent in the overlap between treatments, emphasizing the importance of performing transcriptome analysis in the context of physiological response. In addition to documenting increases in transcripts of specific genes involved in processes predicted to be required for thermotolerance (i.e. protection of proteins and of translation, limiting oxidative stress), we also found decreases in transcripts (i.e. for programmed cell death, basic metabolism, and biotic stress responses), which are likely equally important for acclimation. Similar protective effects may also be achieved differently, such as prevention of proline accumulation, which is toxic at elevated temperatures and which was reduced by both acclimation treatments but was associated with transcript changes predicted to either reduce proline synthesis or increase degradation in the two acclimation treatments. Finally, phenotypic analysis of T-DNA insertion mutants of genes identified in this analysis defined eight new genes involved in heat acclimation, including cytosolic ascorbate peroxidase and the transcription factors HsfA7a (heat shock transcription factor A7a) and NF-X1.
PRR3 Is a Vascular Regulator of TOC1 Stability in theArabidopsisCircadian Clock
Authors: Para Alessia , Farré Eva M. , Imaizumi Takato , Pruneda-Paz José L. , Harmon Franklin G. , Kay Steve A. 
Published: December 2007

AbstractThe pseudoresponse regulators (PRRs) participate in the progression of the circadian clock in Arabidopsis thaliana. The founding member of the family, TIMING OF CAB EXPRESSION1 (TOC1), is an essential component of the transcriptional network that constitutes the core mechanism of the circadian oscillator. Recent data suggest a role in circadian regulation for all five members of the PRR family; however, the molecular function of TOC1 or any other PRRs remains unknown. In this work, we present evidence for the involvement of PRR3 in the regulation of TOC1 protein stability. PRR3 was temporally coexpressed with TOC1 under different photoperiods, yet its tissue expression was only partially overlapping with that of TOC1, as PRR3 appeared restricted to the vasculature. Decreased expression of PRR3 resulted in reduced levels of TOC1 protein, while overexpression of PRR3 caused an increase in the levels of TOC1, all without affecting the amount of TOC1 transcript. PRR3 was able to bind to TOC1 in yeast and in plants and to perturb TOC1 interaction with ZEITLUPE (ZTL), which targets TOC1 for proteasome-dependent degradation. Together, our results indicate that PRR3 might function to modulate TOC1 stability by hindering ZTL-dependent TOC1 degradation, suggesting the existence of local regulators of clock activity and adding to the growing importance of posttranslational regulation in the design of circadian timing mechanisms in plants.