Electromagnetic field and other physical methods influencing cell growth in mammal cell culture systems

The growth rate of cultured mammalian cells can be influenced by chemical and physical methods such as electromagnetic fields (EMF), light, temperature and plasma. These physical methods have a number of well documented effects on mammalian cells including modification of gene expression, cell cycle, invasion, motility, cell viability, proliferation, apoptosis and mammosphere numbers. A study of the existing literature confirms that the impact of physical method on mammalian cells depends on the cell type, culture environment, exposure time, frequency, wave shape, and amount of dose. The modification of cell proliferation and apoptosis is necessary for cells products, tissue engineering, and therapy. In this article, we reviewed the impact of four physical methods on the growth rate and viability of cells. Plasma is the best method among fours because we can get desired result ranging from increasing cell proliferation to inducing apoptosis depending on the dose.

Water quality, bacterial flora and production in shrimp farms in Sri Lanka

This study investigated the possibilities of improvement in the brackish water shrimp culture industry in Sri Lanka. Feeding rates could be further reduced without negative effect on shrimp growth while improving effluent water quality. Improvements of feed quality and pond management practices were also suggested.

Epidemiology and management of Penaeus monodon farms in Andhra Pradesh, India

Disease outbreaks on shrimp farms studied in Andhra Pradesh were caused mainly by white spot syndrome virus (WSSV) significantly reducing yield. Shrimp seed was the major source of WSSV but several risk factors were also involved. Implementation of better management practices (BMPs) at farm and farm cluster level through formation of Self-Help Groups could significantly improve crop outcomes in farms.

Climate change impacts : challenges for aquaculture

In spite of all the debates and controversies, a global consensus has been reached that climate change is a reality and that it will impact, in diverse manifestations that may include increased global temperature, sea level rise, more frequent occurrence of extreme weather events, change in weather patterns, etc., on food production systems, global biodiversity and overall human well being. Aquaculture is no exception. The sector is characterized by the fact that the organisms cultured, the most diverse of all farming systems and in the number of taxa farmed, are all poikilotherms. It occurs in fresh, brackish and marine waters, and in all climatic regimes from temperate to tropical. Consequently, there are bound to be many direct impacts on aquatic farming systems brought about by climate change. The situation is further exacerbated by the fact that certain aquaculture systems are dependent, to varying degrees, on products such as fishmeal and fish oil, which are derived from wild-caught resources that are subjected to reduction processes. All of the above factors will impact on aquaculture in the decades to come and accordingly, the aquatic farming systems will begin to encounter new challenges to maintain sustainability and continue to contribute to the human food basket. The challenges will vary significantly between climatic regimes. In the tropics, the main challenges will be to those farming activities that occur in deltaic regions, which also happen to be hubs of aquaculture activity, such as in the Mekong and Red River deltas in Viet Nam and the Ganges-Brahamaputra Delta in Bangladesh. Aquaculture in tropical deltaic areas will be mostly impacted by sea level rise, and hence increased saline water intrusion and reduced water flows, among others. Elsewhere in the tropics, inland cage culture and other aquaculture activities could be impacted by extreme weather conditions, increased upwelling of deoxygenated waters in reservoirs, etc., requiring greater vigilance and monitoring, and even perhaps readiness to move operations to more conducive areas in a waterbody. Indirect impacts of climate change on tropical aquaculture could be manifold but are perhaps largely unknown. The reproductive cycles of a great majority of tropical species are dependent on monsoonal rain patterns, which are predicted to change. Consequently, irrespective of whether cultured species are artificially propagated or not, changes in reproductive cycles will impact on seed production and thereby the whole grow-out cycle and modus operandi of farm activities. Equally, such impacts will be felt on the culture of those species that are based on natural spat collection, such as that of many cultured molluscs. In the temperate region, global warming could raise temperatures to the upper tolerance limits of some cultured species, thereby making such culture systems vulnerable to high temperatures. New or hitherto non-pathogenic organisms may become virulent with increases in water temperature, confronting the sector with new, hitherto unmanifested and/or little known diseases. One of the most important indirect effects of climate change will be driven by impacts on production of those fish species that are used for reduction, and which in turn form the basis for aquaculture feeds, particularly for carnivorous species. These indirect effects are likely to have a major impact on some key aquaculture practices in all climatic regimes. Limitations of supplies of fishmeal and fish oil and resulting exorbitant price hikes of these commodities will lead to more innovative and pragmatic solutions on ingredient substitution for aquatic feeds, which perhaps will be a positive result arising from a dire need to sustain a major sector. Aquaculture has to be proactive and start addressing the need for adaptive and mitigative measures. Such measures will entail both technological and socio-economic approaches. The latter will be more applicable to small-scale farmers, who happen to be the great bulk of producers in developing countries, which in turn constitute the “backbone’ of global aquaculture. The sociological approaches will entail the challenge of addressing the potential climate change impacts on small farming communities in the most vulnerable areas, such as in deltaic regions, weighing the most feasible adaptive options and bringing about the policy changes required to implement these adaptive measures economically and effectively. Global food habits have changed over the years. We are currently in an era where food safety and quality, backed up by ecolabelling, are paramount; it was not so 20 years ago. In the foreseeable future, we will move into an era where consumer consciousness will demand that farmed foods of every form will have to include in their labeled products the green house gas (GHG) emissions per unit of produce. Clearly, aquaculture offers an opportunity to meet these aspirations. Considering that about 70 percent of all finfish and almost 100 percent of all molluscs and seaweeds are minimally GHG emitting, it is possible to drive aquaculture as the most GHG-friendly food source. The sector could conform to such demands and continue to meet the need for an increasing global food fish supply. However, to achieve this, a paradigm shift in our seafood consumption preferences will be needed.

Differentiation of cultured epithelial cells : response to toxic agents

Cell culture systems are instrumental in elucidating regulation of normal function and mechanisms of its perturbation by toxic substances. To this end, three applications of epithelial cells cultured with 3T3 feeder layer support are described. First, treatment of the premalignant human epidermal keratinocyte line SCC-12F2 with the tumor promoter 12-O-tetradecanoylphorbol-13-acetate suppressed cell growth and differentiation. This agent produced a biphasic growth response greatly inhibiting cell growth at 1 to 10 nM, but much less above 100 nM. Expression of the differentiated functions involucrin and transglutaminase was found to be inhibited markedly at concentrations above 10 nM. Second, 3-methylcholanthrene toxicity was surveyed in a variety of rat epithelial cell types. The two most sensitive to growth inhibition were epidermal and mammary epithelial cells, while those from bladder, prostate, thyroid, and endometrium were insensitive to growth inhibition. Great differences were evident even among those cells derived from stratified squamous epithelia (epidermal, esophageal, vaginal, forestomach) despite their expression of aryl hydrocarbon hydroxylase activities to similar degrees. Finally, expression of estrogen receptors in rat endometrial cells was shown to be stimulated by the cAMP-elevating agent forskolin. Maximal stimulation of 3- to 6-fold occurred in 6 hr, compatible with a requirement for protein synthesis. Although expressing keratinocyte character (transglutaminase activity and envelope forming ability), the cells thus retain some hormonal character that may be modulated by cAMP-dependent kinase activity. Pursuit of such results will aid in understanding differences in response among cell types and species, in elucidating mechanisms of action of known toxic substances and, ultimately, in predicting toxicity of less well understood agents.

Agency theory, national culture and management Control Systems

Management control system of an organization is the structured facet of management, the formal vehicle by which the management process is executed. In most organizations, systems exist for planning, organizing, directing, controlling and motivating. Depending on the level of appropriateness and quality of the management control systems, the task of management is either facilitated or hindered. The end goal of a management control system is achieving organizational objectives. Because employees (agents) do not always give their best efforts for achieving organizational objectives, management control systems need to strive for aligning goals of agents (e.g., employees, subordinates) with that of principals (e.g., senior management, owners). Agency theory and its extension, principal agent model, provide insights to the problem of goal congruence and suggest remedies, at least in the Western cultural context. Whether the agency theory presumptions, predictions and prescriptions are universally applicable is an important issue in management. Their validity in different cultural contexts is largely unknown. The available literature to date indicates the possibility that agency theory may not be valid in non-western cultures. However, further empirical research is needed in non-western cultures to shed more light to this issue.

Agency theory and culture : implications for research in management control systems

The objective of this paper is to encourage further research into the applicability of agency theory for the study of management control issues of organisations in Asian societies.

The influence of collectivism in society and its implications for research on information systems and national culture

This paper argues that the nature of IS research that deals with indigenous culture must be informed as much by context as it is by culture models, which has been the focus of such research in the past. This is considered important because it better reflects the meaning of the data collected for the researcher. To appreciate the importance of context this papers also argues that research subjects from designated individualist societies will inform the researcher in different ways from those subjects located in collectivist societies. To illustrate the practical implications of this argument the paper reports three separate case studies in IS research where the researchers reflect on the impact that a collectivist view has had on the research findings. The paper suggests that (1) similar ethnicity and appearance are significant in gaining the trust of subjects in a collectivist society; that is the researcher is part of the in-group as they belong to the same culture or ethnic group; that (2) who introduced the researcher to the subject is significant in that trust is best reflected when a member of the group/collective plays an important role in the research process itself; and that (3) an ability to (a) communicate in the natural language and (b) understand the implicit body language and (c) cultural codes is important in gaining significant and more meaningful research outcomes. This is enabled via the implicit meanings embedded in members of the collectivist society.

Analysis of cultural conflict in the development of web-enabled information systems

The advent of the World Wide Web (WWW) and the emergence of Internet commerce have given rise to the web as a medium of information exchange. In recent years, the phenomenon has affected the realm of transaction processing systems, as organizations are moving from designing web pages for marketing purposes, to web-based applications that support business-to-business (WEB) and business-to-consumer (B2C) interactions, integrated with databases and other back-end systems (Isakowitz, Bieber et al., 1998). Furthermore, web-enabled applications are increasingly being used to facilitate transactions even between various business units within a single enterprise. Examples of some of the more popular web-enabled applications in use today include airline reservation systems, internet banking, student enrollment systems in universities, and Human Resource (HR) and payroll systems. The prime motive behind the adoption of web-enabled applications are productivity gains due to reduced processing time, decrease in the usage of paper-based documentation and conventional modes of communication (such as letters, fax, or telephone), and improved quality of services to clients. Indeed, web-based solutions are commonly referred to as customer-centric (Li, 2000), which means that they provide user interfaces that do not necessitate high level of computer proficiency. Thus, organizations implement such systems to streamline routine transactions and gain strategic benefits in the process (Nambisan & Wang, 1999), though the latter are to be expected in the long-term. Notwithstanding the benefits of web technology adoption, the web has ample share of challenges for initiators and developers. Many of these challenges are associated with the unique nature of web-enabled applications. Research in the area of web-enabled information systems has revealed several differences with traditional applications. These differences exist with regards to system development methodology, stakeholder involvement, tasks, and technology (Nazareth, 1998). According to Fraternali (1999), web applications are commonly developed using an evolutionary prototyping approach, whereby the simplified version of the application is deployed as a pilot first, in order to gather user feedback. Thus, web-enabled applications typically undergo continuous refinement and evolution (Ginige, 1998; Nazareth, 1998; Siau, 1998; Standing, 2001). Prototype-based development also leads web-enabled information systems to have much shorter development life cycles, but which, unlike traditional applications, are regrettably developed in a rather adhoc fashion (Carstensen & Vogelsang, 2001). However, the principal difference between the two kinds of applications lies in the broad and diverse group of stakeholders associated with web-based information systems (Gordijn, Akkermans, et al., 2000; Russo, 2000; Earl & Khan, 2001; Carter, 2002; Hasselbring, 2002; Standing, 2002; Stevens & Timbrell, 2002). Stakeholders, or organizational members participating in a common business process (Freeman, 1984), vary in their computer competency, business knowledge, language and culture. This diversity is capable of causing conflict between different stakeholder groups with regards to the establishment of system requirements (Pouloudi & Whitley, 1997; Stevens & Timbrell, 2002). Since, web-based systems transcend organizational, departmental, and even national boundaries, the issue of culture poses a significant challenge to the web systems’ initiators and developers (Miles & Snow, 1992; Kumar & van Dissel, 1996; Pouloudi & Whitley, 1996; Li & Williams, 1999).

Cultural differences, information and code systems

This paper explores an alternative way of framing information systems research on the role and impact of national culture. It argues that the widely accepted structural framework of Hofstede reduces interpretation to a simplistic categorical description which in many cases ignores differentiation within cultures. The alternative model suggests, that national culture can be better understood by seeking out the dominant codes that frame the discourse pervasive in a culture and understanding how that discourse affects the obvious social codes of ritual, custom and behavior and the textual codes which express the nature of that culture. This framework is applied to two different case studies—one in New Zealand and one in Thailand—to demonstrate its applicability.

Towards a multicultural world : identifying work systems, practices and employee attitudes that embrace diversity

The research program described focuses on identifying the role of organisational culture, as reflected in workplace systems and practices, and employee and group attitudes in the outcomes of interactions among dissimilar parties. A systematic, theory-testing approach underlies the program, which aims to both develop and validate the diversity openness construct. The Perceived Dissimilarity-Openness Moderator Model developed from the research asserts that the affective, cognitive and behavioural consequences of diversity depend in part upon the perception of difference and subsequent quality and magnitude of the response to the perceived dissimilarity. When individuals or social systems (groups or organisations) are diversity-closed, outcomes are predicted to be less positive than when they are diversity-open.