Approaches to Supply Chain Risk Management: Identification, Analysis and Control

Supply chain risk management has emerged as an increasingly important issue in logistics as disruptions in the supply chain have become critical issues for many companies. The scientific literature on the subject is developing and in many respects the understanding of it is still in its infancy. Thus, there is a need for more information in order for scholars and practitioners to understand the causalities and interrelations that characterise the phenomenon. The aim of this dissertation is to narrow this gap by exploring key aspects of supply chain risk management through two maritime supply chains in the immediate region of the Gulf of Finland. The study contributes to the field in three different ways. Firstly, it facilitates the identification of risks on different levels of the supply chain through a systematic analysis of the processes and actors, and of the cognitive barriers that limit the actors’ visibility and their understanding of the operations and the risks involved. There is a clear need to increase collaboration and information exchange in order to improve visibility in the chain. Risk management should be a collaborative effort among the individual actors, aimed at obtaining a holistic picture. Secondly, the study contributes to the literature on risk analysis through the use of systemic frameworks that illustrate the causalities and linkages in the system, thereby making it easier to perceive the vulnerabilities. Thirdly, the study enhances current knowledge of risk control in identifying actor roles, risk visibility and risk controllability as being among the key factors determining risk-management effectiveness against supply-chain vulnerability. This dissertation is divided into two parts. The first part gives a general overview of the relevant literature, the research design and the conclusions of the study, and the second part comprises six research publications. Case-study methodology with systematic combining approach is used, where in-depth interviews, questionnaires and expert panel sessions are the main data collection methods. The study illustrates the current state of risk management in multimodal maritime supply chains, and develops frameworks for further analysis. The results imply that there are major differences between organizations in their ability to execute supply chain risk management. Further collaboration should be considered in order to facilitate the development of systematic and effective management processes.

Enhancing absorptive capacity in a non-research and development. An action research approach to converting individual observations into organisational awareness

The ability to recognize potential knowledge and convert it into business opportunities is one of the key factors of renewal in uncertain environments. This thesis examines absorptive capacity in the context of non-research and development innovation, with a primary focus on the social interaction that facilitates the absorption of knowledge. It proposes that everyone is and should be entitled to take part in the social interaction that shapes individual observations into innovations. Both innovation and absorptive capacity have been traditionally related to research and development departments and institutions. These innovations need to be adopted and adapted by others. This so-called waterfall model of innovations is only one aspect of new knowledge generation and innovation. In addition to this Science–Technology–Innovation perspective, more attention has been recently paid to the Doing–Using–Interacting mode of generating new knowledge and innovations. The amount of literature on absorptive capacity is vast, yet the concept is reified. The greater part of the literature links absorptive capacity to research and development departments. Some publications have focused on the nature of absorptive capacity in practice and the role of social interaction in enhancing it. Recent literature on absorptive capacity calls for studies that shed light on the relationship between individual absorptive capacity and organisational absorptive capacity. There has also been a call to examine absorptive capacity in non-research and development environments. Drawing on the literature on employee-driven innovation and social capital, this thesis looks at how individual observations and ideas are converted into something that an organisation can use. The critical phases of absorptive capacity, during which the ideas of individuals are incorporated into a group context, are assimilation and transformation. These two phases are seen as complementary: whereas assimilation is the application of easy-to-accept knowledge, transformation challenges the current way of thinking. The two require distinct kinds of social interaction and practices. The results of this study can been crystallised thus: “Enhancing absorptive capacity in practicebased non-research and development context is to organise the optimal circumstances for social interaction. Every individual is a potential source of signals leading to innovations. The individual, thus, recognises opportunities and acquires signals. Through the social interaction processes of assimilation and transformation, these signals are processed into the organisation’s reality and language. The conditions of creative social capital facilitate the interplay between assimilation and transformation. An organisation that strives for employee-driven innovation gains the benefits of a broader surface for opportunity recognition and faster absorption.” If organisations and managers become more aware of the benefits of enhancing absorptive capacity in practice, they have reason to assign resources to those practices that facilitate the creation of absorptive capacity. By recognising the underlying social mechanisms and structural features that lead either to assimilation or transformation, it is easier to balance between renewal and effective operations.

Searching for keys to successful post-merger integration : a longitudinal case-study following a public sector merger

Unsuccessful mergers are unfortunately the rule rather than the exception. Therefore it is necessary to gain an enhanced understanding of mergers and post-merger integrations (PMI) as well as learning more about how mergers and PMIs of information systems (IS) and people can be facilitated. Studies on PMI of IS are scarce and public sector mergers are even less studied. There is nothing however to indicate that public sector mergers are any more successful than those in the private sector. This thesis covers five studies carried out between 2008 and 2011 in two organizations in higher education that merged in January 2010. The most recent study was carried out two years after the new university was established. The longitudinal case-study focused on the administrators and their opinions of the IS, the work situation and the merger in general. These issues were investigated before, during and after the merger. Both surveys and interviews were used to collect data, to which were added documents that both describe and guide the merger process; in this way we aimed at a triangulation of findings. Administrators were chosen as the focus of the study since public organizations are highly dependent on this staff category, forming the backbone of the organization and whose performance is a key success factor for the organization. Reliable and effective IS are also critical for maintaining a functional and effective organization, and this makes administrators highly dependent on their organizations’ IS for the ability to carry out their duties as intended. The case-study has confirmed the administrators’ dependency on IS that work well. A merger is likely to lead to changes in the IS and the routines associated with the administrators’ work. Hence it was especially interesting to study how the administrators viewed the merger and its consequences for IS and the work situation. The overall research objective is to find key issues for successful mergers and PMIs. The first explorative study in 2008 showed that the administrators were confident of their skills and knowledge of IS and had no fear of having to learn new IS due to the merger. Most administrators had an academic background and were not anxious about whether IS training would be given or not. Before the merger the administrators were positive and enthusiastic towards the merger and also to the changes that they expected. The studies carried out before the merger showed that these administrators were very satisfied with the information provided about the merger. This information was disseminated through various channels and even negative information and postponed decisions were quickly distributed. The study conflicts with the theories that have found that resistance to change is inevitable in a merger. Shortly after the merger the (third) study showed disappointment with the fact that fewer changes than expected had been implemented even if the changes that actually were carried out sometimes led to a more problematic work situation. This was seen to be more prominent for routine changes than IS changes. Still the administrators showed a clear willingness to change and to share their knowledge with new colleagues. This knowledge sharing (also tacit) worked well in the merger and the PMI. The majority reported that the most common way to learn to use new ISs and to apply new routines was by asking help from colleagues. They also needed to take responsibility for their own training and development. Five months after the merger (the fourth study) the administrators had become worried about the changes in communication strategy that had been implemented in the new university. This was perceived as being more anonymous. Furthermore, it was harder to get to know what was happening and to contact the new decision makers. The administrators found that decisions, and the authority to make decisions, had been moved to a higher administrative level than they were accustomed to. A directive management style is recommended in mergers in order to achieve a quick transition without distracting from the core business. A merger process may be tiresome and require considerable effort from the participants. In addition, not everyone can make their voice heard during a merger and consensus is not possible in every question. It is important to find out what is best for the new organization instead of simply claiming that the tried and tested methods of doing things should be implemented. A major problem turned out to be the lack of management continuity during the merger process. Especially problematic was the situation in the IS-department with many substitute managers during the whole merger process (even after the merger was carried out). This meant that no one was in charge of IS-issues and the PMI of IS. Moreover, the top managers were appointed very late in the process; in some cases after the merger was carried out. This led to missed opportunities for building trust and management credibility was heavily affected. The administrators felt neglected and that their competences and knowledge no longer counted. This, together with a reduced and altered information flow, led to rumours and distrust. Before the merger the administrators were convinced that their achievements contributed value to their organizations and that they worked effectively. After the merger they were less sure of their value contribution and effectiveness even if these factors were not totally discounted. The fifth study in November 2011 found that the administrators were still satisfied with their IS as they had been throughout the whole study. Furthermore, they believed that the IS department had done a good job despite challenging circumstances. Both the former organizations lacked IS strategies, which badly affected the IS strategizing during the merger and the PMI. IS strategies deal with issues like system ownership; namely who should pay and who is responsible for maintenance and system development, for organizing system training for new IS, and for effectively run IS even during changing circumstances (e.g. more users). A proactive approach is recommended for IS strategizing to work. This is particularly true during a merger and PMI for handling issues about what ISs should be adopted and implemented in the new organization, issues of integration and reengineering of IS-related processes. In the new university an ITstrategy had still not been decided 26 months after the new university was established. The study shows the importance of the decisive management of IS in a merger requiring that IS issues are addressed in the merger process and that IS decisions are made early. Moreover, the new management needs to be appointed early in order to work actively with the IS-strategizing. It is also necessary to build trust and to plan and make decisions about integration of IS and people.

Measuring effects of strategic utilization of social media in business-to-business marketing: Case Greenlux Finland Oy

Utilization of social media is increasingly common in B2B marketing. Social media is an efficient and cheap marketing and communication channel available for everyone, and thus extremely attractive marketing medium. The more companies get involved in social media the more failures are reported. It is not enough for a company to just be present in social media. Succeeding on it requires hard work, investing time and money, and ability to measure and to monitor performance. With an increasing number of companies failing in utilizing social media, together with lack of research on strategic utilization of social media focusing on B2B marketing, measuring, and monitoring create a purpose for this research. The aim of this research is to discover methods for measuring and monitoring effects of strategic utilization of social media in B2B marketing. Most relevant financial and non-financial indicators are discussed, and the methods by which these can be monitored and measured. In addition, effects of strategic utilization of social media on the case company are measured and analyzed. The research methodology used in this research is a participatory action research, which includes elements of both qualitative and quantitative research methods. The case company examined in the research provides a unique opportunity to follow through all phases of strategic utilization of social media for B2B marketing purposes concluding real effects of social media to the case company, and thus gain a deep understanding about this new marketing medium in the perspective of B2B marketing. Duration of the research period is seven months. During this time, information is collected, measured, and analyzed. Case company does not have any other marketing activities simultaneously which makes it possible to examine social media apart from effects of other visible marketing activities. Effects of strategic utilization of social media can be monitored and measured in many ways. Methods that should be used depend on goals set for social media. Fundamental nature of social media requires multidimensional assessment, and thus effects should be measured, and monitored considering both financial and non-financial indicators. The results implicates that effects of strategic utilization of social media are relatively wide ranged. According to the findings, social media affects positively on brand, number of web page visitors, visitor behavior, and on distribution of awareness. According to investment calculations social media is a legitimate investment for case company. Results also implicate that by using social media case company gains conversation, arouses interest, gets attention, and creates interactivity. In addition and as a side note, winter holiday season appears to have a great effect on social media activity of B2B companies’ representatives.

System-level characterization of Th2 cell development and immune cell responses to ZnO and TiO2 nanoparticles

Asthma and allergy are common diseases and their prevalence is increasing. One of the hypotheses that explains this trend is exposure to inhalable chemicals such as traffi c-related air pollution. Epidemiological research supports this theory, as a correlation between environmental chemicals and allergic respiratory diseases has been found. In addition to ambient airborne particles, one may be exposed to engineered nanosized materials that are actively produced due to their favorable physico-chemical properties compared to their bulk size counterparts. On the cellular level, improper activity of T helper (Th) cells has been connected to allergic reactions. Th cells can differentiate into functionally different effector subsets, which are identifi ed according to their characteristic cytokine profi les resulting in specifi c ability to communicate with other cells. Th2 cells activate humoral immunity and stimulate eradication of extracellular pathogens. However, persistent predominance of Th2 cells is involved in a development of number of allergic diseases. The cytokine environment at the time of antigen recognition is the major factor determining the polarization of a naïve Th cell. Th2 cell differentiation is initiated by IL4, which signals via transcription factor STAT6. Although the importance of this pathway has been evaluated in the mouse studies, the signaling components involved have been largely unknown. The aim of this thesis was to identify molecules, which are under the control of IL4 and STAT6 in Th cells. This was done by using system-level analysis of STAT6 target genes at genome, mRNA and protein level resulting in identifi cation of various genes previously not connected to Th2 cell phenotype acquisition. In the study, STAT6-mediated primary and secondary target genes were dissection from each other and a detailed transcriptional kinetics of Th2 cell polarization of naïve human CD4+ T cells was collected. Integration of these data revealed the hierarchy of molecular events that mediates the differentiation towards Th2 cell phenotype. In addition, the results highlighted the importance of exploiting proteomics tools to complement the studies on STAT6 target genes identifi ed through transcriptional profi ling. In the last subproject, the effects of the exposure with ZnO and TiO2 nanoparticles was analyzed in Jurkat T cell line and in primary human monocyte-derived macrophages and dendritic cells to evaluate their toxicity and potential to cause infl ammation. Identifi cation of ZnO-derived gene expression showed that the same nanoparticles may elicit markedly distinctive responses in different cell types, thus underscoring the need for unbiased profi ling of target genes and pathways affected. The results gave additional proof that the cellular response to nanosized ZnO is due to leached Zn2+ ions. The approach used in ZnO and TiO2 nanoparticle study demonstrated the value of assessing nanoparticle responses through a toxicogenomics approach. The increased knowledge of Th2 cell signaling will hopefully reveal new therapeutic nodes and eventually improve our possibilities to prevent and tackle allergic infl ammatory diseases.

Is hypoxia a stressor to American bullfrog tadpoles?

The aim of this study was to evaluate alterations to the physiological profile of cortisol in pro-metamorphose phase tadpoles of Lithobates catesbeianus exposed to hypoxia stressor in a capture experiment and in a crowding experiment. The capture study was performed by the treatments: stress due to individual capture with a hand net, stress due to batch capture with a hand net and stress due to capture by emptying. Three simultaneous replicates was done witch 12 animals were sampled (6 normoxia - immediately blood collection) and 6 hypoxia - blood collection after 15 min of air exposition) in two collection times with 5 days by intervals. The crowding study was performed by the treatments 1 tadpole L-1, 5 tadpoles L-1 and 10 tadpoles L-1. Three simultaneous replicates was done witch 8 animals (4 normoxia and 4 hypoxia) were sampled in the zero moment (ZM) - blood collection before the experiment, 6 animals/treatment (3 normoxia and 3 hypoxia) to 4 and 8 days and 18 animals/treatment (9 normoxia and 9 hypoxia) to 12 days. The average values to plasmatic cortisol varying from 1.7 to 5.1ng mL-1 (capture study) and 1.0 to 4.2ng mL-1 (crowding study). It concludes that the biomarker tested (cortisol) showed no alterations front of the stressor used. Alternatively, a larger response pattern to these stimuli may have been expressed in another level of an unmeasured hormone (corticosterone). And the bullfrog has great ability to adapt to different management compared to other aquatic organisms, which demonstrates the plasticity of these animals.

Evaluation of a MPB70-ELISA to differentiate Mycobacterium bovis from M. avium-sensitized swine

Swine are susceptible to different mycobacteria species, being Mycobacterium bovis an agent of tuberculosis, with most significant zoonotic risks, while M. avium determines a granulomatous lymphadenitis with low zoonotic risk. Currently performed intradermal tests present some important limitations, such as the lack of ability to detect anergic animals or to differentiate among mycobacterial species. In order to improve the TB diagnosis, serological assays have been developed, with encouraging results. The purpose of this study was to evaluate the performance of a MPB70-ELISA in 82 piglets divided into four groups: sensitized by inactivated M. bovis, M. avium, inoculated with oil adjuvant, or with saline solution. The test was able to discriminate between an animal sensitized by M. bovis and animals of the three other groups, including M. avium-sensitized animals; for this reason, we suggest that MPB70-ELISA could be used as a complementary tool for discriminating the agent of the mycobacteriosis, and therefore to diagnose tuberculosis in a swine herd.

Industrial solution business – transition from product to solution offering

The business logic in the manufacturing industry has changed in the 21st century. In the current industrial market, manufacturers are driven to provide more comprehensive offerings that go beyond the traditional product-orientation by providing capacity and availability for their customers. From incidental merchandise, services have become the core of manufacturers’ offerings with long-lasting service agreements over the life-cycles of their products. This change is driven both by the need of providers to grow and gain competitive advantage and by increased customer demand caused by customers’ outsourcing trends. The three key drivers for manufacturers’ service strategies are outsourcing trends, saturation of the installed base, and commoditization in product markets. Thus, manufacturers focus on providing industrial solutions which are delivered through relational processes with customers by using solution-driven business models. In the management of marketing activities, this can be regarded as closer customer relationships, service-dominant business logic, and collaboration in solving customers’ problems. However, there are few studies on comprehensive conceptualizations of a solution offering that include different elements and their roles, especially in the context of capital goods industry. Also the transition process needs further studies in a real life context. This study explores the transition process of an industrial company from product to solution business and, as an aid to managing the solution business, explicates the structure and management of an industrial solution offering. There are two themes, the industrial transition process and industrial solution offering. Regarding the industrial transition process, the aim is to understand the supplier view on the process and its execution and to determine the challenges related to the transition process. The industrial solution offering is discussed by its elements and characteristics, as well as management. Furthermore, a special type of build-own-operate-transfer business model is presented and its suitability in the industrial context analyzed. The study includes findings achieved by qualitative methods and from four case companies. Based on the results, it is tentatively suggested that in the industrial solution business, the transition from product to solution business is not a linear project but an evolving process that varies according to customer needs, which suggests that companies need to possess an ability to develop new business models for different customer needs. The industrial solution offering is dynamic as it evolves in collaboration according to the prevailing and latent customer needs, which suggest restructuring of the organization from a product-centric to a customer-centric one. Furthermore, based on the findings, the concept of industrial solutions is defined as an ongoing relational process to satisfy a customer’s particular business or operational requirements, and the concept of industrial solution offering as an entity comprising the customized goods, services, collaboration, and finance needed to fulfill the industrial solution. Finally, the study offers several managerial implications for industrial managers involved in the transition and management of the solution business and its offering.

The accumulation of financial and social capital as a means to achieve a sustained competitive advantage for consumer co-operatives

By so far, scholars have discussed how the characteristics of consumer co-operatives (cooperative principles, values and the dual role of members as the users and owners) can potentially give them a competitive advantage over investor-owned firms (IOFs). In addition, concern for the community (as partly derived from locality and regionality) has been seen as a potential source of success for consumer co-operatives. On the other hand, the geographicbound purpose of consumer co-operation causes that consumer co-operative can be regarded as a challenging company form to manage. This is because, according to the purpose of consumer co-operation, co-operatives are obligated to 1) provide the owners with services and goods that are needed and do so at more affordable prices than their competitors do and/or 2) to operate in areas in which competitors do not want to operate (for example, because of the low profitability in certain area of business or region). Thus, consumer co-operatives have to operate very efficiently in order to execute this geographic-bound corporate purpose (e.g. they cannot withdraw from the competition during the declining stages of business). However, this efficiency cannot be achieved by any means; as the acceptance from the important regional stakeholders is the basic operational precondition and lifeline in the long run. Thereby, the central question for the survival and success of consumer co-operatives is; how should the consumer co-operatives execute its corporate purpose so it can be the best alternative to its members in the long run? This question has remained unanswered and lack empirical evidence in the previous studies on the strategic management of consumer cooperation. In more detail, scholars have not yet empirically investigated the question: How can consumer co-operatives use financial and social capital to achieve a sustained competitive advantage? It is this research gap that this doctoral dissertation aims to fulfil. This doctoral dissertation aims to answer the above questions by combining and utilizing interview data from S Group co-operatives and the central organizations in S Group´s network (overall, 33 interviews were gathered), archival material and 56 published media articles/reports. The study is based on a qualitative case study approach that is aimed at theory development, not theory verification (as the theory is considered as nascent in this field of study). Firstly, the findings of this study indicate that consumer co-operatives accumulate financial capital; 1) by making profit (to invest and grow) and 2) by utilizing a network-based organizational structure (local supply chain economies). As a result of financial capital accumulation, consumer co-operatives are able to achieve efficiency gains but also remain local. In addition, a strong financial capital base increases consumer co-operatives´ independence, competitiveness and their ability to participate in regional development (which is in accordance with their geographically bound corporate purpose). Secondly, consumer cooperatives accumulate social capital through informal networking (with important regional stakeholders), corporate social responsibility (CSR) behaviour and CSR reporting, pursuing common good, and interacting and identity sharing. As a result of social capital accumulation, consumer co-operatives are able to obtain the resources for managing; 1) institutional dependencies and 2) customer relations. By accumulating both social and financial capital through the above presented actions, consumer co-operatives are able to achieve sustained competitive advantage. Finally, this thesis provides useful ideas and new knowledge for cooperative managers concerning why and how consumer co-operatives should accumulate financial and social capital (to achieve sustained competitive advantage), while aligning with their corporate purpose.

Designing a user interface for game developers to enter game specific information

Designing user interfaces for novel software systems can be challenging since the usability preferences of the users are not well known. This thesis presents a usability study conducted for the development of a user interface for game developers to enter game specific information. By conducting usability testing, the usability preferences of game developers were explored and the design was shaped according to their needs. An assessment of the overall usability of the final design is provided together with the main findings that include the usability preferences and design recommendations. The results showed that the most valuable usability preferences are quickness, error tolerance and the ability to constantly inspect the entered information.

Competitive ability of soybean cultivars with horseweed (Conyza bonariensis)

The existence of large areas infested with populations of Conyza spp. resistant to glyphosate in Brazil demands appropriate and integrated management strategies. This experiment aimed to identify soybean cultivars with greater competitive ability with horseweed plants and to determine plant characteristics associated with this ability. The experiment was arranged in a randomized complete block design with split plots. Seven soybean cultivars (CD 225 RR, BRS 232, CD 226 RR, NK 7054 RR, BMX Apollo RR, BRS 245 RR and BRS 255 RR) were allocated in the plots, and two interference situations (absence and 13.3 plants of Conyza m-2, transplanted seven days before soybean planting) in the subplots. The average yield loss due to competition with horseweed was 25%. Cultivar CD 226 RR showed no significant grain yield loss due to competition, compared to the control without infestation, but showed the lowest average grain yield. The BRS 232 genotype showed loss of grain yield of only 14%, and presented positive plant height and leaf mass at 20 DAE, as well as dry matter of stems+branches in all evaluations, features related to its higher performance and greater ability to withstand competition with horseweed plants.

A search for RFLP markers to identify genes for aluminum tolerance in maize

The objective of this study was to identify restriction fragment length polymorphism (RFLP) markers linked to QTLs that control aluminum (Al) tolerance in maize. The strategy used was bulked segregant analysis (BSA) and the genetic material utilized was an F2 population derived from a cross between the Al-susceptible inbred line L53 and Al-tolerant inbred line L1327. Both lines were developed at the National Maize and Sorghum Research Center - CNPMS/EMBRAPA. The F2 population of 1554 individuals was evaluated in a nutrient solution containing a toxic concentration of Al and relative seminal root length (RSRL) was used as a phenotypic measure of tolerance. The RSRL frequency distribution was continuous, but skewed towards Al-susceptible individuals. Seedlings of the F2 population which scored the highest and the lowest RSRL values were transplanted to the field and subsequently selfed to obtain F3 families. Thirty F3 families (15 Al-susceptible and 15 Al-tolerant) were evaluated in nutrient solution, using an incomplete block design, to identify those with the smallest variances for aluminum tolerance and susceptibility. Six Al-susceptible and five Al-tolerant F3 families were chosen to construct one pool of Al-susceptible individuals, and another of Al-tolerant, herein referred as "bulks", based on average values of RSRL and genetic variance. One hundred and thirteen probes were selected, with an average interval of 30 cM, covering the 10 maize chromosomes. These were tested for their ability to discriminate the parental lines. Fifty-four of these probes were polymorphic, with 46 showing codominance. These probes were hybridized with DNA from the two contrasting bulks. Three RFLPs on chromosome 8 distinguished the bulks on the basis of band intensity. DNA of individuals from the bulks was hybridized with these probes and showed the presence of heterozygous individuals in each bulk. These results suggest that in maize there is a region related to aluminum tolerance on chromosome 8

Human DNA repair diseases: From genome instability to cancer

Several human genetic syndromes have long been recognized to be defective in DNA repair mechanisms. This was first discovered by Cleaver (1968), who showed that cells from patients with xeroderma pigmentosum (XP) were defective for the ability to remove ultraviolet (UV)-induced lesions from their genome. Since then, new discoveries have promoted DNA repair studies to one of the most exciting areas of molecular biology. The present work intends to give a brief summary of the main known human genetic diseases related to DNA repair and how they may be linked to acquired diseases such as cancer

Coupling of palmitate to ovalbumin inhibits the induction of oral tolerance

Oral tolerance is a phenomenon that may occur in animals exposed to protein antigens for the first time by the oral route. They become unable to produce immune responses at the levels normally observed when they are immunized parenterally with antigen in the presence of adjuvants. Lipids have been used as adjuvants for both parenteral and oral immunization. In the present study we coupled ovalbumin with palmitate residues by incubating the protein with the N-hydroxysuccinimide palmitate ester and tested the preparation for its ability to induce oral tolerance. This was performed by giving 20 mg of antigen to mice by the oral route 7 days prior to parenteral immunization in the presence of Al(OH)3. Mice were bled one week after receiving a booster that was given 2 weeks after primary immunization. Specific antibodies were detected by ELISA. Despite the fact that the conjugates are as immunogenic as the unmodified protein when parenterally injected in mice, they failed to induce oral tolerance. This discrepancy could be explained by differences in the intestinal absorption of the two forms of the antigen. In fact, when compared to the non-conjugated ovalbumin, a fast and high absorption of the lipid-conjugated form of ovalbumin was observed by "sandwich" ELISA.

Liposomes: from biophysics to the design of peptide vaccines

Liposomes (lipid-based vesicles) have been widely studied as drug delivery systems due to their relative safety, their structural versatility concerning size, composition and bilayer fluidity, and their ability to incorporate almost any molecule regardless of its structure. Liposomes are successful in inducing potent in vivo immunity to incorporated antigens and are now being employed in numerous immunization procedures. This is a brief overview of the structural, biophysical and pharmacological properties of liposomes and of the current strategies in the design of liposomes as vaccine delivery systems.