933 resultados para JAPANESE OYSTER


Relevância:

20.00% 20.00%

Publicador:

Resumo:

General note: Title and date provided by Bettye Lane.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

General note: Title provided by Freda Leinwand.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

An increasing number of studies are now reporting the effects of ocean acidification on a broad range of marine species, processes and systems. Many of these are investigating the sensitive early life-history stages that several major reviews have highlighted as being potentially most susceptible to ocean acidification. Nonetheless there remain few investigations of the effects of ocean acidification on the very earliest, and critical, process of fertilization, and still fewer that have investigated levels of ocean acidification relevant for the coming century. Here we report the effects of near-future levels of ocean acidification (?0.35 pH unit change) on sperm swimming speed, sperm motility, and fertilization kinetics in a population of the Pacific oyster Crassostrea gigas from western Sweden. We found no significant effect of ocean acidification - a result that was well-supported by power analysis. Similar findings from Japan suggest that this may be a globally robust result, and we emphasise the need for experiments on multiple populations from throughout a species' range. We also discuss the importance of sound experimental design and power analysis in meaningful interpretation of non-significant results.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Anthropogenic carbon dioxide (CO2) emissions reduce pH of marine waters due to the absorption of atmospheric CO2 and formation of carbonic acid. Estuarine waters are more susceptible to acidification because they are subject to multiple acid sources and are less buffered than marine waters. Consequently, estuarine shell forming species may experience acidification sooner than marine species although the tolerance of estuarine calcifiers to pH changes is poorly understood. We analyzed 23 years of Chesapeake Bay water quality monitoring data and found that daytime average pH significantly decreased across polyhaline waters although pH has not significantly changed across mesohaline waters. In some tributaries that once supported large oyster populations, pH is increasing. Current average conditions within some tributaries however correspond to values that we found in laboratory studies to reduce oyster biocalcification rates or resulted in net shell dissolution. Calcification rates of juvenile eastern oysters, Crassostrea virginica, were measured in laboratory studies in a three-way factorial design with 3 pH levels, two salinities, and two temperatures. Biocalcification declined significantly with a reduction of ~0.5 pH units and higher temperature and salinity mitigated the decrease in biocalcification.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The postwar development of the Intelligence Services in Japan has been based on two contrasting models: the centralized model of the USA and the collegiality of UK, neither of which has been fully developed. This has led to clashes of institutional competencies and poor anticipation of threats towards national security. This problem of opposing models has been partially overcome through two dimensions: externally through the cooperation with the US Intelligence Service under the Treaty of Mutual Cooperation and Security; and internally though the pre-eminence in the national sphere of the Department of Public Safety. However, the emergence of a new global communicative dimension requires that a communicative-viewing remodeling of this dual model is necessary due to the increasing capacity of the individual actors to determine the dynamics of international events. This article examines these challenges for the Intelligence Services of Japan and proposes a reform based on this new global communicative dimension.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The goal of this thesis is twofold. Firstly, it investigates the actual, native use of spatial-deictic demonstratives in Japanese, Finnish and Swedish. Secondly, it investigates and elucidates the interlanguage of Finnish-speaking and Swedish-speaking learners of Japanese regarding their use of Japanese spatial-deictic demonstratives in the light of respective native use and, in comparison to the descriptions of demonstratives in the teaching materials used. Thus, the present study deals with analyses of two sets of empirical data: data produced by native-speaking informants (L1 data) and data produced by language learners (L2 data). These were elicited by Discourse Completion Tasks (DCTs) designed, collected and analyzed using both quantitative and qualitative methods by the author. The results showed that the actual use of demonstratives by the native informants was not always in accordance with the way described in grammars. The typological similarities between Japanese and Finnish were in this study not reflected in the native use of demonstratives, and some uses were not solely based on the spatial relations between the referent, the speaker and the addressee, but rather on social-interactional factors. The main findings regarding the learner data revealed some differences in the usage rate of the demonstratives between the two Finnish-speaking groups and the one Swedish-speaking learner group studied. There were, however, no particular differences found between them regarding the type of demonstrative used. It is suggested that these differences are first and foremost connected both with the teaching materials used and the more or less heterogeneous linguistic environment in which the learners reside, and only thereafter with the typological similarities or differences between their respective native languages, Finnish and Swedish, and the target language, Japanese. It is further argued that the learners’ use of the different Japanese demonstratives, that is the type of demonstrative used, could be explained in terms of familiarity with the grammar. That is, when the situations used in the DCTs were exemplified in teaching materials and were familiar to them, the learners seemed to use Japanese demonstratives as they are described in the teaching materials and as the native Japanese speakers use them. When the situations used in the DCTs were not exemplified in the teaching materials, the learners seem to rely more on their native language. The results, thus, suggest that the learners’ interlanguage is influenced by the grammar of the target language known to the learners, but also by the number of languages (or varieties) that the learners have contact with at the time of learning. The results of the present study have implications for the teaching of Japanese in at least two ways. Firstly, the importance of grammar instruction must be emphasized since its effect on the learners’ language is apparent. Secondly, the contents of teaching materials should be revised on the basis of the native speakers’ actual use of the grammar.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Kanji, the Chinese characters adopted to write the Japanese language, is often mentioned as one of the most difficult aspects of mastering said language. This is especially said about people from outside the Sinosphere i.e. PRC, Taiwan, North and South Korea, Japan and Vietnam. In the following thesis 12 students studying the Japanese language at Swedish universities were interviewed about their experiences when it comes to learning and being taught about kanji. A chapter summarizing some of the research that is relevant to this thesis is also included. Topics touched upon in this and the result chapter include the desire for more structured approach to kanji learning based on breaking down the characters into elemental components, spaced repetition (SRS), mnemonics.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Strategy is a highly topical subject among managers and since the world is constantlychanging it is also an important subject for companies’ competitive advantage and survival.At the same time experts in the field of strategic management describe western techniques ascomplex and ineffective while the Japanese techniques have been seen as unambiguous andcharacterized by focus on quality, productivity and teamwork. This calls for greaterknowledge in the Japanese management systems. Hoshin Kanri is a collection of Japanesebest strategic management practices and therefore an interesting target for our study. Thus, onthe one hand this study investigates the theory of Hoshin Kanri in order to give structure to itand provide a way for practitioner into the management system. On the other hand this studyinvestigates Hoshin Kanri in order to reveal how Japanese subsidiaries based in Sweden haveimplemented this strategic management system. This is firstly done by reviewing the existingliterature on the subject and secondly by a collective case study with in-depth interviewsconducted with managers at Japanese owned subsidiaries based in Sweden. There are somelimitations in this study. One is that the results of the study do not include all Japanesesubsidiaries in Sweden as not all companies participated in the study. Moreover, the study islimited by one individuals’ knowledge and perception of Hoshin Kanri in each of the threecompanies. The study contributes to the existing literature on the topic of Hoshin Kanri by;(1) structuring the literature and the existing models under one of two categories, namelycyclical or sequential; (2) providing a model that aims at making it more understandable andattractive for practitioner to apply; (3) initiating the mapping of the spread of Hoshin Kanriamong Japanese subsidiaries in Sweden and (4) providing a Swedish model for theapplication of HK in Japanese subsidiaries.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

The protozoan parasite Marteilia refringens has been partly responsible for the severe decrease in the production of the European flat oyster Ostrea edulis Linnaeus in France since the 1970s. The calanoid copepod Paracartia grani Sars was recently found to be a host for M refringens in French shallow-water oyster ponds ('claires'). This study reconsidered M refringens transmission dynamics in the light of this finding, taking into account not only oyster infection dynamics and environmental factors but also data concerning the copepod host. P. grani population dynamics in the claire under study revealed that this species is the dominant planktonic copepod in this confined ecosystem. During winter, M refringens overwintered in O. edulis, with P. grani existing only as resting eggs in the sediment. The increase in temperature in spring controlled and synchronized both the release of M refringens sporangia in the oyster feces, and the hatching of the benthic resting eggs of the copepod. Infection of oysters by M refringens was limited to June, July and August, coinciding with (1) the highest temperature recorded in the claire, and (2) the highest abundance of P. grani. PCR detection of M refringens in P. grani during the summer period was linked to the release of parasite sporangia by the oyster. Our results are supported by previous results on the effective transmission of this parasite from the oyster to the copepod.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Among bivalve species, the Pacific oyster, Crassostrea gigas, is the most economically important bivalve production over the world. Today, C. gigas is subject to an important production effort that leads to an intensive artificial selection. Larval stage is relatively unknown, specifically in a domestication context. Genetic consequence of artificial selection is still at a preliminary study. We aimed to tackle the consequence of inconscient domestication on the variance reproductive success focusing on larval stage, keystone of the life cycle. We studied two kinds of specific selective processes that common hatchery rearing practices exert : the effect of discarding the smallest larvae on genetic diversity and the artificial environment rearing effect via the temperature providing a contrast resembling wild versus hatchery conditions (20 and 26°C). In order to monitor the effect of the selection of fast growing larvae by sieving, growth variability and genetic diversity in a larval population descended from a factorial breeding was studied. We used a mixed-family approach to reduce potentially confounding environmental biais. The retrospective assignment of individuals to family groups has been performed using a three microsatellite markers set. Two different rearing were carried out in parallel. For three (replicates) 50-l tanks, the smallest larvae were progressively discarded by selective sieving, whereas for the three others no selective sieving was performed. The intensity of selective sieving was adjusted so as to discard 50% of the larvae over the whole rearing period in a progressive manner. As soon as the larvae reached the pediveliger stage, ready to settle larvae were sampled for genetic analysis. Regarding the artificial environment rearing effect via the temperature, we used a similar mixed-family approach. The progeny from a factorial breeding design was divided as follows: three (replicates) 50-l tanks were dedicaced to a rearing at 26°C versus 20°C for three others 50-l tanks. The whole size variability was preserved for this experiment. Individual growth measurements for larvae genetically identified have been performed at days 22 and 30 after fertilization for both conditions. In a same way, we collected individual measurements for genotyped juvenile oysters (80 days after fertilization). At a phenotypic scale, relative survival and settlement success for larvae with sieving were higher. Sieving appears as a time-saving process associated with a better relative survival ratio. But in the same time, our results confirm that a significant genetic variability exist for early developmental traits in the Pacific oyster. This is congruent with the results already obtained that investigated genetic variability and genetic correlations in early life-history traits of Crassostrea gigas. Discarding around 50% of the smallest larvae can lead to significant selection at the larval stage.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Understanding the sense of authenticity of heritage attractions is important for tourism management and marketing because presentation, interpretation and verification has a direct bearing on motivations to visit and engage with heritage tourism sites. This paper establishes relationships among the concepts of culturally specific motivation, perception of authenticity, engagement and attendant behavioral consequences based on domestic visitors' experiences at Japanese heritage sites. It further extends Kolar and Zabkar's (2010) model of authenticity by including concepts of serious leisure, heritage related behaviors, self-connection and their effects over engagement using Partial Least Square, whereby both formative and reflective scales are included. The structural model is tested with a sample of 768 visitors in a culturally specific setting of Japanese heritage sites. The empirical validation of the conceptual model supports the research hypotheses. These findings contribute to a better understanding of visitors' perceptions and valuation of authenticity in Japanese tourist attractions. Several implications can be drawn from the study findings and interesting directions for future research are provided.

Relevância:

20.00% 20.00%

Publicador:

Resumo:

Apoptosis is a fundamental feature in the development of many organisms and tissue systems. It is also a mechanism of host defense against environmental stress factors or pathogens by contributing to the elimination of infected cells. Hemocytes play a key role in defense mechanisms in invertebrates and previous studies have shown that physical or chemical stress can increase apoptosis in hemocytes in mollusks. However this phenomenon has rarely been investigated in bivalves especially in the flat oyster Ostrea edulis. The apoptotic response of hemocytes from flat oysters, O. edulis, was investigated after exposure to UV and dexamethasone, two agents known to induce apoptosis in vertebrates. Flow cytometry and microscopy were combined to demonstrate that apoptosis occurs in flat oyster hemocytes. Investigated parameters like intracytoplasmic calcium activity, mitochondrial membrane potential and phosphatidyl-serine externalization were significantly modulated in cells exposed to UV whereas dexamethasone only induced an increase of DNA fragmentation. Morphological changes were also observed on UV-treated cells using fluorescence microscopy and transmission electron microscopy. Our results confirm the apoptotic effect of UV on hemocytes of O. edulis and suggest that apoptosis is an important mechanism developed by the flat oyster against stress factors.