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1.
Mol Ecol ; 33(9): e17337, 2024 May.
Artigo em Inglês | MEDLINE | ID: mdl-38558465

RESUMO

Phylogeography bears an important part in ecology and evolution. However, current phylogeographic studies are largely constrained by limited numbers of individual samples. Using an environmental DNA (eDNA) assay for phylogeographic analyses, this study provides detailed information regarding the history of Siberian stone loach Barbatula toni, a primary freshwater fish across the whole range of Hokkaido, Japan. Based on an eDNA metabarcoding on 293 river water samples, we detected eDNA from B. toni in 189 rivers. A total of 51 samples, representing the entire island, were then selected from the B. toni eDNA-positive sample set for the subsequent analyses. To elucidate the phylogeographic structure of B. toni, newly developed eDNA metabarcoding primers (Barba-cytb-F/R) were applied to these samples, specifically targeting their haplotypic variation in cytochrome b. After a bioinformatic processing to mitigate haplotypic false positives, a total of 50 eDNA haplotypes were identified. Two regionally restricted, genetically distinct lineages of the species were revealed as a result of phylogeographic analyses on the haplotypes and tissue-derived DNA from B. toni. According to a molecular clock analysis, they have been genetically isolated for at least 1.5 million years, suggesting their ancient origin and colonisation of Hokkaido, presumably in the glacial periods. These results demonstrate how freshwater fishes can alter their distributions over evolutionary timescales and how eDNA assay can deepen our understanding of phylogeography.


Assuntos
Código de Barras de DNA Taxonômico , DNA Ambiental , Haplótipos , Filogeografia , Rios , Animais , Haplótipos/genética , Japão , DNA Ambiental/genética , Citocromos b/genética , Água Doce , Filogenia , Cipriniformes/genética , Cipriniformes/classificação
2.
PLoS One ; 15(10): e0239912, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33002065

RESUMO

Migratory organisms have their own life histories that efficiently link multiple ecosystems. Therefore, comprehensive understanding of migration ecologies of these organisms is essential for both species conservation and ecosystem management. However, monitoring migration at fine spatiotemporal scales, especially in open marine systems, often requires huge costs and effort. Recently, environmental DNA (eDNA) techniques that utilize DNA released from living organisms into their environment became available for monitoring wild animals without direct handling. In this study, we conducted an eDNA survey for understanding marine migration of an endemic fish species, Shishamo smelt (Spirinchus lanceolatus). We examined 1) seasonal habitat changes in coastal regions and 2) environmental factors potentially driving the migration of this species. The eDNA concentrations along a 100 km-long coastline exhibited spatiotemporal variation, suggesting that this species shifts their habitat away from nearshore areas between spring and summer. We also found a significantly negative association between the eDNA concentration and sea surface temperature. That finding suggests that the offshore migration of this species is associated with increased sea surface temperature. This study reveals new aspects of S. lanceolatus life history in coastal regions. Together with our previous eDNA study on the freshwater migration of S. lanceolatus, this study illustrates the potential of eDNA techniques for understanding the whole life history of this migratory species.


Assuntos
Migração Animal , DNA Ambiental/genética , Osmeriformes/fisiologia , Animais , Ecossistema , Osmeriformes/genética , Estações do Ano
3.
PLoS One ; 14(9): e0222052, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-31483846

RESUMO

To understand the ecology of juvenile chum salmon during early marine life after their downstream migration, we developed a quantitative PCR-based environmental DNA (eDNA) method specific for chum salmon and investigated the spatiotemporal distribution of eDNA in Otsuchi Bay, Iwate, Japan. Indoor aquarium experiments demonstrated the following characteristics of chum salmon eDNA: (1) the eDNA shedding and degradation were time- and water temperature-dependent and the bacterial abundance could contribute to the eDNA decay, (2) fecal discharge may not be the main source of eDNA, and (3) a strong positive Pearson correlation was found between the number of juveniles and the eDNA amounts. As we discovered strong PCR inhibition from the seawater samples of the bay, we optimized the eDNA assay protocol for natural seawater samples by adding a further purification step and modification of PCR mixture. The intensive eDNA analysis in the spring of 2017 and 2018 indicated that juvenile chum salmon initially inhabited in shallow waters in the shorefront area and then spread over the bay from January to June. The eDNA data also pointed out that outmigration of juvenile chum salmon to open ocean temporarily suspended in April, possibly being associated with the dynamics of the Oyashio Current as suggested by a previous observation. The eDNA method thus enables us large-scale and comprehensive surveys without affecting populations to understand the spatiotemporal dynamics of juvenile chum salmon.


Assuntos
DNA Ambiental , Monitoramento Ambiental , Oncorhynchus keta/genética , Análise Espaço-Temporal , Animais , Baías , Japão , Especificidade da Espécie , Inquéritos e Questionários
4.
Sci Transl Med ; 10(470)2018 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-30518611

RESUMO

Exposure to electromagnetic radiation can have a profound impact on human health. Ultraviolet (UV) radiation from the sun causes skin cancer. Blue light affects the body's circadian melatonin rhythm. At the same time, electromagnetic radiation in controlled quantities has beneficial use. UV light treats various inflammatory skin conditions, and blue light phototherapy is the standard of care for neonatal jaundice. Although quantitative measurements of exposure in these contexts are important, current systems have limited applicability outside of laboratories because of an unfavorable set of factors in bulk, weight, cost, and accuracy. We present optical metrology approaches, optoelectronic designs, and wireless modes of operation that serve as the basis for miniature, low-cost, and battery-free devices for precise dosimetry at multiple wavelengths. These platforms use a system on a chip with near-field communication functionality, a radio frequency antenna, photodiodes, supercapacitors, and a transistor to exploit a continuous accumulation mechanism for measurement. Experimental and computational studies of the individual components, the collective systems, and the performance parameters highlight the operating principles and design considerations. Evaluations on human participants monitored solar UV exposure during outdoor activities, captured instantaneous and cumulative exposure during blue light phototherapy in neonatal intensive care units, and tracked light illumination for seasonal affective disorder phototherapy. Versatile applications of this dosimetry platform provide means for consumers and medical providers to modulate light exposure across the electromagnetic spectrum in a way that can both reduce risks in the context of excessive exposure and optimize benefits in the context of phototherapy.


Assuntos
Fontes de Energia Elétrica , Miniaturização/instrumentação , Fototerapia , Dosímetros de Radiação , Exposição à Radiação , Monitoramento de Radiação/instrumentação , Luz Solar , Tecnologia sem Fio , Humanos , Recém-Nascido , Unidades de Terapia Intensiva Neonatal , Raios Ultravioleta
5.
Evol Appl ; 11(6): 1010-1025, 2018 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-29928306

RESUMO

Genetic interaction between domesticated escapees and wild conspecifics represents a persistent challenge to an environmentally sustainable Atlantic salmon aquaculture industry. We used a recently developed eco-genetic model (IBSEM) to investigate potential changes in a wild salmon population subject to spawning intrusion from domesticated escapees. At low intrusion levels (5%-10% escapees), phenotypic and demographic characteristics of the recipient wild population only displayed weak changes over 50 years and only at high intrusion levels (30%-50% escapees) were clear changes visible in this period. Our modeling also revealed that genetic changes in phenotypic and demographic characteristics were greater in situations where strayers originating from a neighboring wild population were domestication-admixed and changed in parallel with the focal wild population, as opposed to nonadmixed. While recovery in the phenotypic and demographic characteristics was observed in many instances after domesticated salmon intrusion was halted, in the most extreme intrusion scenario, the population went extinct. Based upon results from these simulations, together with existing knowledge, we suggest that a combination of reduced spawning success of domesticated escapees, natural selection purging maladapted phenotypes/genotypes from the wild population, and phenotypic plasticity, buffer the rate and magnitude of change in phenotypic and demographic characteristics of wild populations subject to spawning intrusion of domesticated escapees. The results of our simulations also suggest that under specific conditions, natural straying among wild populations may buffer genetic changes in phenotypic and demographic characteristics resulting from introgression of domesticated escapees and that variation in straying in time and space may contribute to observed differences in domestication-driven introgression among native populations.

6.
PLoS One ; 13(1): e0190233, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29293664

RESUMO

Excessive ultraviolet (UV) radiation induces acute and chronic effects on the skin, eye and immune system. Personalized monitoring of UV radiation is thus paramount to measure the extent of personal sun exposure, which could vary with environment, lifestyle, and sunscreen use. Here, we demonstrate an ultralow modulus, stretchable, skin-mounted UV patch that measures personal UV doses. The patch contains functional layers of ultrathin stretchable electronics and a photosensitive patterned dye that reacts to UV radiation. Color changes in the photosensitive dyes correspond to UV radiation intensity and are analyzed with a smartphone camera. A software application has feature recognition, lighting condition correction, and quantification algorithms that detect and quantify changes in color. These color changes are then correlated with corresponding shifts in UV dose, and compared to existing UV dose risk levels. The soft mechanics of the UV patch allow for multi-day wear in the presence of sunscreen and water. Two evaluation studies serve to demonstrate the utility of the UV patch during daily activities with and without sunscreen application.


Assuntos
Eletrônica , Epiderme/fisiologia , Fotoquímica , Raios Ultravioleta , Algoritmos , Corantes , Humanos
7.
Evol Appl ; 10(2): 121-139, 2017 02.
Artigo em Inglês | MEDLINE | ID: mdl-28127389

RESUMO

Intraspecific variation is a major component of biodiversity, yet it has received relatively little attention from governmental and nongovernmental organizations, especially with regard to conservation plans and the management of wild species. This omission is ill-advised because phenotypic and genetic variations within and among populations can have dramatic effects on ecological and evolutionary processes, including responses to environmental change, the maintenance of species diversity, and ecological stability and resilience. At the same time, environmental changes associated with many human activities, such as land use and climate change, have dramatic and often negative impacts on intraspecific variation. We argue for the need for local, regional, and global programs to monitor intraspecific genetic variation. We suggest that such monitoring should include two main strategies: (i) intensive monitoring of multiple types of genetic variation in selected species and (ii) broad-brush modeling for representative species for predicting changes in variation as a function of changes in population size and range extent. Overall, we call for collaborative efforts to initiate the urgently needed monitoring of intraspecific variation.

8.
Sci Rep ; 7: 40368, 2017 01 12.
Artigo em Inglês | MEDLINE | ID: mdl-28079122

RESUMO

Environmental DNA (eDNA) metabarcoding has emerged as a potentially powerful tool to assess aquatic community structures. However, the method has hitherto lacked field tests that evaluate its effectiveness and practical properties as a biodiversity monitoring tool. Here, we evaluated the ability of eDNA metabarcoding to reveal fish community structures in species-rich coastal waters. High-performance fish-universal primers and systematic spatial water sampling at 47 stations covering ~11 km2 revealed the fish community structure at a species resolution. The eDNA metabarcoding based on a 6-h collection of water samples detected 128 fish species, of which 62.5% (40 species) were also observed by underwater visual censuses conducted over a 14-year period. This method also detected other local fishes (≥23 species) that were not observed by the visual censuses. These eDNA metabarcoding features will enhance marine ecosystem-related research, and the method will potentially become a standard tool for surveying fish communities.


Assuntos
Biodiversidade , Código de Barras de DNA Taxonômico/métodos , DNA/genética , Monitoramento Ambiental/métodos , Peixes/genética , Animais , Baías , Pesqueiros , Geografia , Japão , Análise de Sequência de DNA , Especificidade da Espécie , Água
9.
Artigo em Inglês | MEDLINE | ID: mdl-27920378

RESUMO

Agriculture is a dominant evolutionary force that drives the evolution of both domesticated and wild species. However, the various mechanisms of agriculture-induced evolution and their socio-ecological consequences are not often synthetically discussed. Here, we explore how agricultural practices and evolutionary changes in domesticated species cause evolution in wild species. We do so by examining three processes by which agriculture drives evolution. First, differences in the traits of domesticated species, compared with their wild ancestors, alter the selective environment and create opportunities for wild species to specialize. Second, selection caused by agricultural practices, including both those meant to maximize productivity and those meant to control pest species, can lead to pest adaptation. Third, agriculture can cause non-selective changes in patterns of gene flow in wild species. We review evidence for these processes and then discuss their ecological and sociological impacts. We finish by identifying important knowledge gaps and future directions related to the eco-evolutionary impacts of agriculture including their extent, how to prevent the detrimental evolution of wild species, and finally, how to use evolution to minimize the ecological impacts of agriculture.This article is part of the themed issue 'Human influences on evolution, and the ecological and societal consequences'.


Assuntos
Agricultura/métodos , Evolução Biológica , Produtos Agrícolas/genética , Domesticação , Adaptação Biológica , Produtos Agrícolas/crescimento & desenvolvimento , Fluxo Gênico
10.
Sci Adv ; 2(8): e1600418, 2016 08.
Artigo em Inglês | MEDLINE | ID: mdl-27493994

RESUMO

Recent advances in materials, mechanics, and electronic device design are rapidly establishing the foundations for health monitoring technologies that have "skin-like" properties, with options in chronic (weeks) integration with the epidermis. The resulting capabilities in physiological sensing greatly exceed those possible with conventional hard electronic systems, such as those found in wrist-mounted wearables, because of the intimate skin interface. However, most examples of such emerging classes of devices require batteries and/or hard-wired connections to enable operation. The work reported here introduces active optoelectronic systems that function without batteries and in an entirely wireless mode, with examples in thin, stretchable platforms designed for multiwavelength optical characterization of the skin. Magnetic inductive coupling and near-field communication (NFC) schemes deliver power to multicolored light-emitting diodes and extract digital data from integrated photodetectors in ways that are compatible with standard NFC-enabled platforms, such as smartphones and tablet computers. Examples in the monitoring of heart rate and temporal dynamics of arterial blood flow, in quantifying tissue oxygenation and ultraviolet dosimetry, and in performing four-color spectroscopic evaluation of the skin demonstrate the versatility of these concepts. The results have potential relevance in both hospital care and at-home diagnostics.


Assuntos
Técnicas Biossensoriais , Eletrônica , Fenômenos Fisiológicos da Pele , Pele , Tecnologia sem Fio , Técnicas Biossensoriais/instrumentação , Técnicas Biossensoriais/métodos , Pressão Sanguínea , Eletrônica/instrumentação , Eletrônica/métodos , Epiderme/fisiologia , Frequência Cardíaca , Oximetria/instrumentação , Oximetria/métodos , Dosímetros de Radiação , Fluxo Sanguíneo Regional
12.
PLoS One ; 11(3): e0149786, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-26933889

RESUMO

Recent studies in streams and ponds have demonstrated that the distribution and biomass of aquatic organisms can be estimated by detection and quantification of environmental DNA (eDNA). In more open systems such as seas, it is not evident whether eDNA can represent the distribution and biomass of aquatic organisms because various environmental factors (e.g., water flow) are expected to affect eDNA distribution and concentration. To test the relationships between the distribution of fish and eDNA, we conducted a grid survey in Maizuru Bay, Sea of Japan, and sampled surface and bottom waters while monitoring biomass of the Japanese jack mackerel (Trachurus japonicus) using echo sounder technology. A linear model showed a high R(2) value (0.665) without outlier data points, and the association between estimated eDNA concentrations from the surface water samples and echo intensity was significantly positive, suggesting that the estimated spatial variation in eDNA concentration can reflect the local biomass of the jack mackerel. We also found that a best-fit model included echo intensity obtained within 10-150 m from water sampling sites, indicating that the estimated eDNA concentration most likely reflects fish biomass within 150 m in the bay. Although eDNA from a wholesale fish market partially affected eDNA concentration, we conclude that eDNA generally provides a 'snapshot' of fish distribution and biomass in a large area. Further studies in which dynamics of eDNA under field conditions (e.g., patterns of release, degradation, and diffusion of eDNA) are taken into account will provide a better estimate of fish distribution and biomass based on eDNA.


Assuntos
DNA/genética , Perciformes/genética , Animais , Baías , Biomassa , Ecossistema , Japão
13.
Front Genet ; 6: 336, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26635872

RESUMO

Recent studies suggest the existence of a stochasticity in gene expression (SGE) in many organisms, and its non-negligible effect on their phenotype and fitness. To date, however, how SGE affects the key parameters of population genetics are not well understood. SGE can increase the phenotypic variation and act as a load for individuals, if they are at the adaptive optimum in a stable environment. On the other hand, part of the phenotypic variation caused by SGE might become advantageous if individuals at the adaptive optimum become genetically less-adaptive, for example due to an environmental change. Furthermore, SGE of unimportant genes might have little or no fitness consequences. Thus, SGE can be advantageous, disadvantageous, or selectively neutral depending on its context. In addition, there might be a genetic basis that regulates magnitude of SGE, which is often referred to as "modifier genes," but little is known about the conditions under which such an SGE-modifier gene evolves. In the present study, we conducted individual-based computer simulations to examine these conditions in a diploid model. In the simulations, we considered a single locus that determines organismal fitness for simplicity, and that SGE on the locus creates fitness variation in a stochastic manner. We also considered another locus that modifies the magnitude of SGE. Our results suggested that SGE was always deleterious in stable environments and increased the fixation probability of deleterious mutations in this model. Even under frequently changing environmental conditions, only very strong natural selection made SGE adaptive. These results suggest that the evolution of SGE-modifier genes requires strict balance among the strength of natural selection, magnitude of SGE, and frequency of environmental changes. However, the degree of dominance affected the condition under which SGE becomes advantageous, indicating a better opportunity for the evolution of SGE in different genetic models.

14.
PLoS One ; 10(9): e0138444, 2015.
Artigo em Inglês | MEDLINE | ID: mdl-26383256

RESUMO

Ecology and genetics can influence the fate of individuals and populations in multiple ways. However, to date, few studies consider them when modelling the evolutionary trajectory of populations faced with admixture with non-local populations. For the Atlantic salmon, a model incorporating these elements is urgently needed because many populations are challenged with gene-flow from non-local and domesticated conspecifics. We developed an Individual-Based Salmon Eco-genetic Model (IBSEM) to simulate the demographic and population genetic change of an Atlantic salmon population through its entire life-cycle. Processes such as growth, mortality, and maturation are simulated through stochastic procedures, which take into account environmental variables as well as the genotype of the individuals. IBSEM is based upon detailed empirical data from salmon biology, and parameterized to reproduce the environmental conditions and the characteristics of a wild population inhabiting a Norwegian river. Simulations demonstrated that the model consistently and reliably reproduces the characteristics of the population. Moreover, in absence of farmed escapees, the modelled populations reach an evolutionary equilibrium that is similar to our definition of a 'wild' genotype. We assessed the sensitivity of the model in the face of assumptions made on the fitness differences between farm and wild salmon, and evaluated the role of straying as a buffering mechanism against the intrusion of farm genes into wild populations. These results demonstrate that IBSEM is able to capture the evolutionary forces shaping the life history of wild salmon and is therefore able to model the response of populations under environmental and genetic stressors.


Assuntos
Fluxo Gênico , Genótipo , Salmo salar/genética , Distribuição Animal , Animais , Genética Populacional , Estágios do Ciclo de Vida , Modelos Teóricos , Noruega , Dinâmica Populacional , Rios
15.
Gene ; 562(1): 16-21, 2015 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-25752289

RESUMO

The role of stochasticity in evolutionary genetics has long been debated. To date, however, the potential roles of non-genetic traits in evolutionary processes have been largely neglected. In molecular biology, growing evidence suggests that stochasticity in gene expression (SGE) is common and that SGE has major impacts on phenotypes and fitness. Here, we provide a general overview of the potential effects of SGE on population genetic parameters, arguing that SGE can indeed have a profound effect on evolutionary processes. Our analyses suggest that SGE potentially alters the fate of mutations by influencing effective population size and fixation probability. In addition, a genetic control of SGE magnitude could evolve under certain conditions, if the fitness of the less-fit individual increases due to SGE and environmental fluctuation. Although empirical evidence for our arguments is yet to come, methodological developments for precisely measuring SGE in living organisms will further advance our understanding of SGE-driven evolution.


Assuntos
Evolução Biológica , Expressão Gênica , Genética Populacional , Modelos Estatísticos , Animais , Humanos , Mutação , Fenótipo , Processos Estocásticos
16.
Int J Urol ; 22(5): 477-82, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25684541

RESUMO

OBJECTIVES: To investigate the therapeutic outcomes of neoadjuvant and concurrent androgen-deprivation therapy and intensity-modulated radiation therapy with gold marker implantation for intermediate- and high-risk prostate cancer. METHODS: This was a retrospective study of 325 patients with intermediate- or high-risk prostate cancer according to the National Comprehensive Cancer Network guidelines who underwent androgen-deprivation therapy and intensity-modulated radiation therapy (76 Gy) after gold marker implantation between 2001 and 2010. RESULTS: The 5-year distant metastasis-free survival rate was significantly lower for very high-risk patients than for intermediate- and high-risk patients (82.6% vs 99.4% and 96.5%, respectively; P < 0.01). The 5-year biochemical relapse-free survival rates significantly declined with increasing prostate cancer risk (P < 0.01), and were 95.9%, 87.2%, and 73.1% for the intermediate-risk, high-risk and very high-risk patients, respectively. Acute genitourinary and gastrointestinal toxicity grade ≥3 were not observed in any of the patients. Late grade 3 genitourinary toxicity occurred in 0.3% of patients. CONCLUSION: Combination androgen-deprivation therapy and 76-Gy intensity-modulated radiation therapy with gold marker implantation offers good therapeutic outcomes with few serious complications in patients with intermediate- and high-risk prostate cancer.


Assuntos
Antagonistas de Androgênios/uso terapêutico , Terapia Neoadjuvante , Neoplasias da Próstata/mortalidade , Neoplasias da Próstata/terapia , Radioterapia de Intensidade Modulada , Idoso , Idoso de 80 Anos ou mais , Intervalo Livre de Doença , Marcadores Fiduciais , Ouro , Humanos , Estimativa de Kaplan-Meier , Masculino , Pessoa de Meia-Idade , Análise Multivariada , Antígeno Prostático Específico , Dosagem Radioterapêutica , Estudos Retrospectivos , Fatores de Risco , Resultado do Tratamento
17.
PLoS One ; 7(12): e51769, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-23272162

RESUMO

Pseudogenes (Ψs), including processed and non-processed Ψs, are ubiquitous genetic elements derived from originally functional genes in all studied genomes within the three kingdoms of life. However, systematic surveys of non-processed Ψs utilizing genomic information from multiple samples within a species are still rare. Here a systematic comparative analysis was conducted of Ψs within 80 fully re-sequenced Arabidopsis thaliana accessions, and 7546 genes, representing ∼28% of the genomic annotated open reading frames (ORFs), were found with disruptive mutations in at least one accession. The distribution of these Ψs on chromosomes showed a significantly negative correlation between Ψs/ORFs and their local gene densities, suggesting a higher proportion of Ψs in gene desert regions, e.g. near centromeres. On the other hand, compared with the non-Ψ loci, even the intact coding sequences (CDSs) in the Ψ loci were found to have shorter CDS length, fewer exon number and lower GC content. In addition, a significant functional bias against the null hypothesis was detected in the Ψs mainly involved in responses to environmental stimuli and biotic stress as reported, suggesting that they are likely important for adaptive evolution to rapidly changing environments by pseudogenization to accumulate successive mutations.


Assuntos
Arabidopsis/genética , Genoma de Planta , Genômica , Pseudogenes , Alelos , Arabidopsis/classificação , Centrômero , Mapeamento Cromossômico , Evolução Molecular , Loci Gênicos , Variação Genética , Fases de Leitura Aberta , Seleção Genética , Análise de Sequência de DNA , Telômero
18.
Artigo em Inglês | MEDLINE | ID: mdl-22057299

RESUMO

The sticking probability, s, of CN(X(2)Σ(+)) radicals onto amorphous carbon nitride (a-CN(x)) films with high [N]/([N]+[C]) ratios (≤0.5) was evaluated. CN(X(2)Σ(+)) radicals were generated from the decomposition of BrCN with the microwave discharge flow of Ar in the two experimental configurations, I and II, where the distance between the tip of the nozzle introducing BrCN is close (≈10 mm) to and distant (≈0.3 m) from the laser-beam path or the Si substrate, respectively. For each configuration, s was evaluated both under the desiccated and H(2)O-added conditions from the number density of CN(X(2)Σ(+)) evaluated from the intensity of the CN(A(2)Π(i)-X(2)Σ(+)) laser-induced fluorescence spectrum calibrated against Rayleigh scattering intensity of Ar, the flow speed measured by a time-resolved emission, and the film mass. The [N]/([N]+[C]) ratios of films were evaluated as 0.4-0.5 and 0.3 in the configurations I and II, respectively, from the compositional analysis using Rutherford back scattering and elastic recoil detection analysis together with the XPS analysis. The variation of s under various experimental conditions was discussed based on the electron densities in the reaction region and the relative density of the hydrogen-termination structures of the film surface.


Assuntos
Argônio/química , Brometos/química , Química Orgânica/métodos , Cianetos/química , Radicais Livres/química , Micro-Ondas , Nitrilas/química , Luz , Espalhamento de Radiação , Espectrofotometria Infravermelho , Análise Espectral Raman
19.
BMC Genet ; 12: 102, 2011 Dec 09.
Artigo em Inglês | MEDLINE | ID: mdl-22151746

RESUMO

BACKGROUND: Reconstructing the evolutionary history of a species is challenging. It often depends not only on the past biogeographic and climatic events but also the contemporary and ecological factors, such as current connectivity and habitat heterogeneity. In fact, these factors might interact with each other and shape the current species distribution. However, to what extent the current population genetic structure reflects the past and the contemporary factors is largely unknown. Here we investigated spatio-temporal genetic structures of Nile tilapia (Oreochromis niloticus) populations, across their natural distribution in Africa. While its large biogeographic distribution can cause genetic differentiation at the paleo-biogeographic scales, its restricted dispersal capacity might induce a strong genetic structure at micro-geographic scales. RESULTS: Using nine microsatellite loci and 350 samples from ten natural populations, we found the highest genetic differentiation among the three ichthyofaunal provinces and regions (Ethiopian, Nilotic and Sudano-Sahelian) (R(ST) = 0.38 - 0.69). This result suggests the predominant effect of paleo-geographic events at macro-geographic scale. In addition, intermediate divergences were found between rivers and lakes within the regions, presumably reflecting relatively recent interruptions of gene flow between hydrographic basins (R(ST) = 0.24 - 0.32). The lowest differentiations were observed among connected populations within a basin (R(ST) = 0.015 in the Volta basin). Comparison of temporal sample series revealed subtle changes in the gene pools in a few generations (F = 0 - 0.053). The estimated effective population sizes were 23 - 143 and the estimated migration rate was moderate (m ~ 0.094 - 0.097) in the Volta populations. CONCLUSIONS: This study revealed clear hierarchical patterns of the population genetic structuring of O. niloticus in Africa. The effects of paleo-geographic and climatic events were predominant at macro-geographic scale, and the significant effect of geographic connectivity was detected at micro-geographic scale. The estimated effective population size, the moderate level of dispersal and the rapid temporal change in genetic composition might reflect a potential effect of life history strategy on population dynamics. This hypothesis deserves further investigation. The dynamic pattern revealed at micro-geographic and temporal scales appears important from a genetic resource management as well as from a biodiversity conservation point of view.


Assuntos
Ciclídeos/genética , África , Migração Animal , Animais , Variação Genética , Genética Populacional , Repetições de Microssatélites , Filogeografia
20.
Int J Radiat Oncol Biol Phys ; 80(1): 119-25, 2011 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-20605363

RESUMO

PURPOSE: S-1 is an oral fluoropyrimidine derivative that has demonstrated favorable antitumor activity in patients with metastatic pancreatic cancer. The aim of this study was to evaluate safety and efficacy of S-1 and concurrent radiotherapy in patients with unresectable locally advanced pancreatic cancer. METHODS AND MATERIALS: Patients with histopathologically proven, unresectable, locally advanced pancreatic cancer were eligible. Radiotherapy was delivered in 1.8 Gy daily fractions to a total dose of 50.4 Gy over 5.5 weeks. S-1 was administered orally twice a day at a dose of 80 mg/m(2)/day from day 1 to 14 and 22 to 35. Two weeks after the completion of chemoradiotherapy, maintenance chemotherapy with S-1 was administered for 28 days every 6 weeks until progression. RESULTS: Thirty-four patients were enrolled in this study. The most common Grade 3 toxicities during chemoradiotherapy were anorexia (24%) and nausea (12%). The overall response rate was 41% (95% confidence interval, 25%-58%) and overall disease control rate (partial response plus stable disease) was 97%. More than 50% decrease in serum CA 19-9 was seen in 27 of 29 evaluable patients (93%). The median progression-free survival was 8.7 months. The median overall survival and 1-year survival rate were 16.8 months and 70.6%, respectively. CONCLUSIONS: Oral S-1 and concurrent radiotherapy exerted a promising antitumor activity with acceptable toxicity in patients with locally advanced pancreatic cancer. This combination therapy seems to be an attractive alternative to conventional chemoradiotherapy using 5-fluorouracil infusion.


Assuntos
Antimetabólitos Antineoplásicos/uso terapêutico , Ácido Oxônico/uso terapêutico , Neoplasias Pancreáticas/tratamento farmacológico , Neoplasias Pancreáticas/radioterapia , Tegafur/uso terapêutico , Adulto , Idoso , Anorexia/etiologia , Antimetabólitos Antineoplásicos/efeitos adversos , Antígeno CA-19-9/sangue , Terapia Combinada/efeitos adversos , Terapia Combinada/métodos , Desoxicitidina/análogos & derivados , Desoxicitidina/uso terapêutico , Progressão da Doença , Esquema de Medicação , Combinação de Medicamentos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Náusea/etiologia , Ácido Oxônico/efeitos adversos , Neoplasias Pancreáticas/mortalidade , Neoplasias Pancreáticas/patologia , Estudos Prospectivos , Dosagem Radioterapêutica , Tegafur/efeitos adversos , Gencitabina
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