DeltaTree: A Practical Locality-aware Concurrent Search Tree

As other fundamental programming abstractions in energy-efficient computing, search trees are expected to support both high parallelism and data locality. However, existing highly-concurrent search trees such as red-black trees and AVL trees do not consider data locality while existing locality-aware search trees such as those based on the van Emde Boas layout (vEB-based trees), poorly support concurrent (update) operations. This paper presents DeltaTree, a practical locality-aware concurrent search tree that combines both locality-optimisation techniques from vEB-based trees and concurrency-optimisation techniques from non-blocking highly-concurrent search trees. DeltaTree is a $k$-ary leaf-oriented tree of DeltaNodes in which each DeltaNode is a size-fixed tree-container with the van Emde Boas layout. The expected memory transfer costs of DeltaTree's Search, Insert, and Delete operations are $O(\log_B N)$, where $N, B$ are the tree size and the unknown memory block size in the ideal cache model, respectively. DeltaTree's Search operation is wait-free, providing prioritised lanes for Search operations, the dominant operation in search trees. Its Insert and {\em Delete} operations are non-blocking to other Search, Insert, and Delete operations, but they may be occasionally blocked by maintenance operations that are sometimes triggered to keep DeltaTree in good shape. Our experimental evaluation using the latest implementation of AVL, red-black, and speculation friendly trees from the Synchrobench benchmark has shown that DeltaTree is up to 5 times faster than all of the three concurrent search trees for searching operations and up to 1.6 times faster for update operations when the update contention is not too high

Non-disclosure of information in the prosecution of preventive detention regimes

Preventive detention has been adopted as a measure of counter-terrorism law in many jurisdictions. It has been authorised under the Security Certificate regime in Canada and the Control Order regime in United Kingdoms. Since their adoption, the two regimes have become objects of much debate. The reason is that they both legalised the use of secret evidence and secret hearings in their prosecution. The issue arose whether the non-disclosure of such information in a judicial review to decide the reasonableness of a control order/a security certificate deprives terrorist suspects from a fair hearing. This paper explores that question by analysing two landmark cases in the United Kingdom and Canada: AF (No 3) and Charkaoui I. The paper’s thesis is that the findings of the courts in these two cases are reasonable. However, the alternative to full disclosure as adopted by both the United Kingdom and Canada – the Special Advocate model – is currently too limited. This paper subsequently offers solution for this: the judges should have a more active role in investigating the relevant facts of the cases

THE INVOLVEMENT OF ENTREPRENER’S NETWORKS IN OPPORTUNITIES EXPLORATION AND EXPLOITATION OF INTERNATIONAL NEW VENTURES. A case study of two Vietnamese International New Ventures

The role and importance of entrepreneur’s network for International New Ventures (INVs) are highlighted in much research. However, there is a lack of more profound studies on how different perspectives of network influence INVs. Therefore, this thesis aims to develop a deeper understanding of the multiple aspects of entrepreneurs’ networks involvement in INVs with regard to opportunity development process. Theoretical framework constitutes of three aspects of entrepreneur’s networks: type, strength and functions of relationships, put in the context of entrepreneurial opportunity’s exploration and exploitation. The theoretical framework is empirically examined through two cases study of two prominent business models in Vietnam economy: State-owned company and Private-owned company. Lastly, empirical part validates and contributes to a better understanding of the framework, hence, answers the research question. It is found that entrepreneurs utilize social network as the most efficient means of rapid internationalization. While entrepreneurs’ weak relationships positively impact business opportunities exploration, strong relationships greatly affect business opportunities exploitation. This study also uncovers more clearly the functions of networks in various critical activities related to opportunity exploration and exploitation.fi=Opinnäytetyö kokotekstinä PDF-muodossa.|en=Thesis fulltext in PDF format.|sv=Lärdomsprov tillgängligt som fulltext i PDF-format

Effect of omega 3 fatty acid on growth in Atlantic salmon (Salmo salar) aquaculture

Background: The effect of diet on fatty acids in Atlantic salmon, particularly omega-3 long-chain polyunsaturated fatty acids (n-3 LC PUFA), has been understudied due to lack of marine raw materials (fish meal and fish oil). A variety of ingredients are used as replacements for fish meal for Atlantic salmon. The aim of this systematic literature review (SLR) is examining the effect of omega 3 fatty acid on growth in Atlantic salmon. Methods: The present study conducted a systematic literature review to provide a summary of currently available information and to identify the most significant effect of omega-3 levels on growth in Atlantic salmon. Main finding: There were not so many studies which met the inclusive criteria, therefore only 21 of 844 papers were selected from which to extract the data. Indicators for the growth such as weight gain, feed conversion ratio (FCR), and specific growth rate (SGR) have been collected from those papers. This study combined multiple studies and analyzed the output data, but it was not exactly a meta-analysis as it did not measure outcome variables in response to a general control and lack of data. 14 of the 21 experiments demonstrated that the reduction of omega 3 fatty acid had no effect on the growth of the fish. Contradictorily, there were two papers that demonstrated that the omega 3 fatty acid directly influences growth in salmon. 5 of the 21 papers found that the growth performance in salmon has been slightly reduced when the fish were fed with less or no omega 3 fatty acid levels. Almost all of the papers concluded that there was no significant difference in the final weight between experiment groups. Conclusion: A potential trend in aquaculture is to include more plant-based ingredients in fish meal to replace the traditional fish meal- and fish oil-based diet. However, digesting plant material may pose a challenge for the fish, influencing the growth performance. Therefore, the minimum requirement for omega 3 fatty acid levels should be upheld during the process of incorporating ingredients into the feed. Further research is required on the ratio of DHA versus EPA to evaluate how each fatty acid affects the growth of Atlantic salmon. Keywords: Omega 3, fatty acid, growth, health, Atlantic salmon, aquaculture, systematic literature review

On uniqueness theorems for holomorphic curves sharing hypersurfaces without counting multiplicity

We prove some uniqueness theorems for algebraically nondegenerate holomorphic curves sharing hyper-surfaces ignoring multiplicity.Доведено деякі теореми єдності для алгебраічих голоморфних кривих, що розділяють гіперплощини без врахування кратності

Nutrition and feeding behaviour in two species of mud crabs Scylla serrata and Scylla paramamosain

Mud crabs of the genus Scylla are widely exploited for aquaculture in the Asia- Pacific region. In the current study, a series of in vivo experiments were carried to assess the protein requirement, protein sparing effects of starch and the capacity of Scylla serrata to digest diets that contained different animal and plant-based feed meals and different levels and types of starch. Results from a protein requirement study indicated that juvenile S. serrata fed diets containing 45% or 55% protein demonstrated significantly higher growth responses than those fed the diet containing 25% protein. The subsequent study was carried out to determine if responses to dietary protein could be influenced by using purified wheat, potato, rice or corn starch to manipulate the gross energy level of fishmeal- based diets (18 or 15.5 MJ kg-1), i.e., to see if starch had a protein sparing effect in these animals. Overall, growth responses in this study appeared to be positively correlated with the level of protein in the diet with the highest growth rates achieved using diets containing 45% protein, regardless of the energy level of the diet. In addition, at a dietary protein level of 40% there was no evidence that the source of starch had any significant impact on growth performance or feed utilisation suggesting it had no protein sparing effect. By contrast, it was found that growth of juvenile S. serrata was strongly correlated with the intake of digestible dietary protein. The investigation of the capacity of sub-adult S. serrata to digest different animal and plant- based feed meals showed that apparent dry matter digestibility (ADMD) and apparent gross energy digestibility (AGED) values were not significant different for most selected feed meals (cotton seed, poultry, canola, fishmeal, soybean, and lupin meal). Apparent crude protein digestibility (ACPD) for all test feed meals were relatively high (86-96%). A subsequent study was carried out to determine if purified starch from different sources influenced the digestibility of fishmeal based diets. Overall, most diets containing starch were readily digested by mud crabs. In particular, there were no negative impacts on the digestibility of major nutrients (e.g. protein) observed following the inclusion of wheat, rice or corn starch in formulated feeds. Nevertheless, the apparent starch digestibility (ASD) of wheat starch decreased significantly as the inclusion level was increased from 15% to 60%, although there was no significant effect on ACPD values. At a 30% inclusion level, the ASD of diets containing different starches decreased in the order corn > wheat > potato = rice. Moreover, ACPD values were significantly higher for diets containing corn or rice starch than for those containing wheat or potato starch. The capacity of another species of mud crab commonly exploited for aquaculture in South East Asia, S. paramamosain, to digest the local plant-based ingredients (defatted soybean meal, rice bran, cassava and corn flour) was also conducted in Vietnam. Overall, the findings of this study showed that at a 30% inclusion level diets containing soybean meal or rice bran were well digested by mud crabs. In particular, the ACPD and AGED values for all diets containing soybean meal were not significantly different from the fishmeal based reference diet. Likewise, all digestibility values for the diet containing 30% rice bran were relatively high and not significantly different from the reference diet. By contrast, diets containing cassava flour appeared to be poorly utilised since their digestibility values for all parameters were lower than those from other testingredients. In summary, the apparent digestibility of dry matter, protein and energy was in the following order (from most to least digestible) soybean meal ~ rice bran > corn flour > cassava flour. In the next study the effects of attractants in diets (chicken meal, betaine, tuna oil and bait enhancer), temperature (26.5oC, 28.5oC and 30.5oC), sex (female and male) and size (small, medium and large) on feeding responses of S. serrata were investigated. Significant differences were observed in the behavioral responses of mud crabs to diets containing different attractants. Specifically, consumption of diets with chicken meal or betaine was significantly higher than for other treatments. With the exception of betaine, no significant difference in food consumption was observed when attractant inclusion levels were raised from 2% to 5%. Overall, small crabs consumed significantly more of the ration (as a percentage of body weight) than larger crabs. Temperature showed a significant impact on most behaviour of mud crabs, excepting continuation response and there was some evidence that females were significantly more active than males. Light intensity was considered as a main factor effect to crab response since there were extremely high percentage time of crab spent in half-shaded of the Y –maze which valued at 95.6%, 93.8 and 94.4% (corresponded to small, medium and large size respectively) in comparison to those of crabs spent in the unshaded side. Overall, the findings from these studies demonstrated that mud crabs have a high capacity to digest a range of plant based feed ingredients. In particular, soybean meal appeared to be well digested by both species of mud crabs examined. It was also shown that a range of purified starches were well digested by S. serrata although starch inclusion in diets did not appear to reduce the requirement for protein to promote growth. Subsequent attractant studies demonstrated that chicken meal and betaine produced significantly elevated feeding responses and food consumption when added to diets. Based on these results we propose that these ingredients can be utilised to increase the attractiveness and consumption of artificial mud crab feeds