170 research outputs found
A Survey on Continuous Time Computations
We provide an overview of theories of continuous time computation. These
theories allow us to understand both the hardness of questions related to
continuous time dynamical systems and the computational power of continuous
time analog models. We survey the existing models, summarizing results, and
point to relevant references in the literature
Silica encapsulation of ZnO nanoparticles reduces their toxicity for cumulus cell-oocyte-complex expansion
Background Metal oxide nanoparticles (NPs) are increasingly used in many industrial and biomedical applications, hence their impact on occupational and public health has become a concern. In recent years, interest on the effect that exposure to NPs may exert on human reproduction has grown, however data are still scant. In the present work, we investigated whether different metal oxide NPs interfere with mouse cumulus cell-oocyte complex (COC) expansion. Methods Mouse COCs from pre-ovulatory follicles were cultured in vitro in the presence of various concentrations of two types of TiO2 NPs (JRC NM-103 and NM-104) and four types of ZnO NPs (JRC NM-110, NM-111, and in-house prepared uncoated and SiO2-coated NPs) and the organization of a muco-elastic extracellular matrix by cumulus cells during the process named cumulus expansion was investigated. Results We show that COC expansion was not affected by the presence of both types of TiO2 NPs at all tested doses, while ZnO NM-110 and NM-111 induced strong toxicity and inhibited COCs expansion at relatively low concentration. Medium conditioned by these NPs showed lower toxicity, suggesting that, beside ion release, inhibition of COC expansion also depends on NPs per se. To further elucidate this, we compared COC expansion in the presence of uncoated or SiO2-coated NPs. Differently from the uncoated NPs, SiO2-coated NPs underwent slower dissolution, were not internalized by the cells, and showed an overall lower toxicity. Gene expression analysis demonstrated that ZnO NPs, but not SiO2-coated ZnO NPs, affected the expression of genes fundamental for COC expansion. Dosimetry analysis revealed that the delivered-to-cell mass fractions for both NPs was very low. Conclusions Altogether, these results suggest that chemical composition, dissolution, and cell internalization are all responsible for the adverse effects of the tested NPs and support the importance of a tailored, safer-by-design production of NPs to reduce toxicity
A knowledge-based framework for service management
peer-reviewedThe purpose of this paper is to investigate how information and communication technologies are used for service standardisation, customisation, and modularisation by knowledge-intensive service firms through the development and empirical validation of a knowledge-based framework. This paper uses 59 in-depth interviews, observational data, and document analysis from case studies of three service-related departments in high-technology, multinational knowledge-intensive business services (KIBSs). Prior research does not conceptualise the relationships between service customisation, standardisation and modularisation. This paper seeks to overcome this gap by integrating insights from research on the role played by both knowledge and information and communication technologies (ICTs) to construct and validate a framework to deal with this gap. It outlines the implications for service firms' use of ICT to deal with increasing knowledge intensity as well as indicating the circumstances under which service knowledge is best customised, standardised and modularised. Further testing in other industries would prove useful in extending the usefulness and applicability of the findings. The originality of the paper lies in developing and validating the first framework to outline the relationship between how service knowledge is customised, standardised or modularised and indicating the associated issues and challenges. It emphasises the role of knowledge and technology. The value of this framework increases as more firms deal with increasing knowledge intensity in the services they provide and in their use of ICTs to reap the benefits of appropriate knowledge reuse.ACCEPTEDpeer-reviewe
Flow and non-flow event anisotropies at the SPS
A study of differential elliptic event anisotropies (v_2) of charged
particles and high-pt pions in 158 AGeV/c Pb+Au collisions is presented.
Results from correlations with respect to the event plane and from two-particle
azimuthal correlations are compared. The latter give systematically higher v_2
values at pt>1.2GeV/c providing possibly an evidence of a non-flow semihard
component.Comment: 4 pages, 6 figures, Quark Matter 2002, Nantes, to appear in Nucl.
Phys.
Climate and sustainability co-governance in Kenya: A multi-criteria analysis of stakeholders' perceptions and consensus
The Paris Agreement and the 2030 Agenda for Sustainable Development embody highly intertwined targets to act for climate in conjunction with sustainable development. This, however, entails different meanings and challenges across the world. Kenya, in particular, needs to address serious sustainability threats, like poverty and lack of modern and affordable energy access. This study uses a multi-criteria group decision aid and consensus measuring framework, to integrate both agendas, and engages with Kenyan stakeholders to help inform future mitigation research and policy in the country. Results showed that stakeholders highlight topics largely underrepresented in model-based mitigation analysis, such as biodiversity preservation and demand-side transformations, while pointing to gaps in cross-sectoral policies in relation to access to modern energy, agriculture, life on land, and climate change mitigation. With numerous past and recent policies aiming at these issues, persistent stakeholder concerns over these topics hint at limited success. Sectoral and technological priorities only recently emphasised in Kenyan policy efforts are also correlated with stakeholders' concerns, highlighting that progress is not only a matter of legislation, but also of coordination, consistency of targets, and comprehensibility. Higher bias is found among the preferences of stakeholders coming from the country's private sector. Results from this exercise can inform national policymakers on effectively reshaping the future direction of the country, as well as modelling efforts aimed at underpinning Kenya's energy, climate and sustainable development policy
Challenges in the harmonisation of global integrated assessment models: a comprehensive methodology to reduce model response heterogeneity
Harmonisation sets the ground to a solid inter-comparison of integrated assessment models. A clear and transparent harmonisation process promotes a consistent interpretation of the modelling outcomes divergences and, reducing the model variance, is instrumental to the use of integrated assessment models to support policy decision-making. Despite its crucial role for climate economic policies, the definition of a comprehensive harmonisation methodology for integrated assessment modelling remains an open challenge for the scientific community. This paper proposes a framework for a harmonisation methodology with the definition of indispensable steps and recommendations to overcome stumbling blocks in order to reduce the variance of the outcomes which depends on controllable modelling assumptions. The harmonisation approach of the PARIS REINFORCE project is presented here to layout such a framework. A decomposition analysis of the harmonisation process is shown through 6 integrated assessment models (GCAM, ICES-XPS, MUSE, E3ME, GEMINI-E3, and TIAM). Results prove the potentials of the proposed framework to reduce the model variance and present a powerful diagnostic tool to feedback on the quality of the harmonisation itself
Language Usage Conditions of Multilingual Nations - Sri Lanka“Sinhalese native speakers and Tamil native speakers\u27 scenes, their word usage conditions in Western Province and Uva Province .
Sri Lanka is a multilingual nation, where various languages, races, and religions exist. Sinhalese, Muslims and Tamils reside together with Burger, Marais and native people called ‘Veddah\u27. Sri Lankan people use three languages; Sinhala, English, and Tamil in their daily communication. To examine the language situation in Sri Lanka means to analyze the cultural and social circumstances within Sri Lanka.In particular the Code Switching (CS) is seen in various situations in Sri Lanka. It is expected that a person would switch the language code depending on the situation. This also differs according to various circumstances such as speaker\u27s life style and living conditions at home, academic background and the social hierarchy. Furthermore, it is estimated that differences in CS between Tamil minority and Sinhala majority would exist. It is important to consider these points in order to examine the situation of communication. English is also used quite often in Sri Lanka. The influence and the necessity of English would be examined through a survey of English usage spreading in the real world.The questionnaire style survey has been conducted and it was administered based on pilot research in Japan. It is necessary to investigate various circumstances that people face in order to examine the true language usage conditions. The investigation considered people in various places and situations throughout Sri Lanka.Sri Lanka consists of nine states. The research was done in eight states: Central Province, Eastern Province, Northern Province, Southern Province, Western Province North western Province, Uva Province and Sabaragamuwa province.The research was done as follows:The locations : at a house of a standard family, at a bank, at a school and at a postoffice in each locations.The subjects : 525 people including students, office workers, house-wives, farmers,and elderly people.The format of investigation: The questionnaire included four communication situations and questionsIn this paper, the language usage conditions of Sinhalese native speakers and the Tamil native speakers of both Western Province and Uva Province are analyzed in various situations. As the result, the Sinhalese native speakers in Western Province showed many examples of code switching between Sinhalese and English. Moreover, English code switching was seen frequently in the home.When considering the Uva Province, the Sinhalese native speakers use both Sinhala and English while a significant proportion of them are trilingual speakers there. They often change between the three main languages; Sinhala, English and Tamil are used quite often at schools, offices, hospitals, and so on.To examine a number of communication scenes in different language groups in Sri Lanka, it was clearly seen that there are more trilingual speakers among Tamil native speakers who more likely to switch between three languages in different situations, while Sinhalese speakers switch between two languages. The data of the survey also showed that the usage of languages varies according to the speakers\u27 social status, region where he or she lives, academic background, age, etc.Moreover, when the communication is taking place at home, the Sinhalese native speakers often use the code switching between Sinhalese and English. However, the elderly people in Sri Lanka, especially people living in Uva Province, rarely speak English due to their poor academic background.It has become clear that the language usage conditions differ from one another depending on the society, the region, and the educational level, and age of the person in Sri Lanka.However it is not well known yet when and how the code switching happens. As for code switching between English and Sinhalese, it is important to record their natural conversation in various scenes to analyze certain characteristics of the code switching. This would help clarify how Sri Lankans use these languages.千葉大学大学院人文社会科学研究科研究プロジェクト報告書第239集「ユーラシアの多言語社会と言語政策」中川裕 編Eurasian Multilingual Society and Language Policy Report on Research Project No.23
Event-by-event fluctuations of the mean transverse momentum in 40, 80, and 158 A GeV/c Pb-Au collisions
Measurements of event-by-event fluctuations of the mean transverse momentum
in Pb-Au collisions at 40, 80, and 158 A GeV/c are presented. A significant
excess of mean p_T fluctuations at mid-rapidity is observed over the
expectation from statistically independent particle emission. The results are
somewhat smaller than recent measurements at RHIC. A possible non-monotonic
behaviour of the mean p_T fluctuations as function of collision energy, which
may have indicated that the system has passed the critical point of the QCD
phase diagram in the range of mu_B under investigation, has not been observed.
The centrality dependence of mean p_T fluctuations in Pb-Au is consistent with
an extrapolation from pp collisions assuming that the non-statistical
fluctuations scale with multiplicity. The results are compared to calculations
by the RQMD and UrQMD event generators.Comment: 28 pages, 10 figure
THE ROLE OF INTERDEPENDENCE IN THE MICRO-FOUNDATIONS OF ORGANIZATION DESIGN: TASK, GOAL, AND KNOWLEDGE INTERDEPENDENCE
Interdependence is a core concept in organization design, yet one that has remained consistently understudied. Current notions of interdependence remain rooted in seminal works, produced at a time when managers’ near-perfect understanding of the task at hand drove the organization design process. In this context, task interdependence was rightly assumed to be exogenously determined by characteristics of the work and the technology. We no longer live in that world, yet our view of interdependence has remained exceedingly task-centric and our treatment of interdependence overly deterministic. As organizations face increasingly unpredictable workstreams and workers co-design the organization alongside managers, our field requires a more comprehensive toolbox that incorporates aspects of agent-based interdependence. In this paper, we synthesize research in organization design, organizational behavior, and other related literatures to examine three types of interdependence that characterize organizations’ workflows: task, goal, and knowledge interdependence. We offer clear definitions for each construct, analyze how each arises endogenously in the design process, explore their interrelations, and pose questions to guide future research
The ALICE TPC, a large 3-dimensional tracking device with fast readout for ultra-high multiplicity events
The design, construction, and commissioning of the ALICE Time-Projection
Chamber (TPC) is described. It is the main device for pattern recognition,
tracking, and identification of charged particles in the ALICE experiment at
the CERN LHC. The TPC is cylindrical in shape with a volume close to 90 m^3 and
is operated in a 0.5 T solenoidal magnetic field parallel to its axis.
In this paper we describe in detail the design considerations for this
detector for operation in the extreme multiplicity environment of central
Pb--Pb collisions at LHC energy. The implementation of the resulting
requirements into hardware (field cage, read-out chambers, electronics),
infrastructure (gas and cooling system, laser-calibration system), and software
led to many technical innovations which are described along with a presentation
of all the major components of the detector, as currently realized. We also
report on the performance achieved after completion of the first round of
stand-alone calibration runs and demonstrate results close to those specified
in the TPC Technical Design Report.Comment: 55 pages, 82 figure
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