Eutrophication is a major concern in the Baltic Sea and it is affecting macrophyte communities by promoting the growth of opportunistic algae and decreasing the cover of perennial macrophyte species via shading. It is however uncertain how common eutrophication and its symptoms are in the northern parts of the Baltic Sea, the Botnian Sea. The aim of this study was to evaluate if Sörleviken, a bay in the Bothnian Sea, show signs of increased eutrophication pressure in 2020 compared to 2007 based on changes in macrophyte cover and composition. The macrophyte community was inventoried with under-water video techniques in 2020 along three transects, matching transects previously inventoried by a diver in 2007. The three transects were located in the inner, middle and the outer parts of the bay. The results showed that macrophyte diversity was lower in 2020 than in 2007 along the outer transect, but overall, the total cover of macrophytes, relative cover of opportunistic algae, species richness and evenness remained unchanged. A possible higher presence of Stuckenia pectinata (former Potamogeton pectinatus) and a possible lower presence of Chara aspera in 2o2o compared to 2007 might be evidence of higher eutrophication pressure in 2020. However, by observing the general changes in the macrophyte community, this study only provides weak or inconclusive signs of increased eutrophication pressure, thus Sörleviken shows no signs of either improvement of or further increases in eutrophication pressure by 2020 compared to the observations in 2007.

Human herpesvirus 6 (HHV-6) infections occur in > 95% of humans. Primary infection, which occurs in early childhood as an asymptomatic illness or manifested clinically as roseola infantum, leads to a state of subclinical viral persistence and latency. Reactivation of latent HHV-6 is common after liver transplantation, possibly induced and facilitated by allograft rejection and immunosuppressive therapy. Since the vast majority of humans harbor the virus in a latent state, HHV-6 infections after liver transplantation are believed to be mostly due to endogenous reactivation or superinfection (reactivation in the transplanted organ). In a minority of cases, however, primary HHV-6 infection may occur when an HHV-6 negative individual receives a liver allograft from an HHV-6 positive donor. The vast majority of documented HHV-6 infections after liver transplantation are asymptomatic. In a minority of cases, HHV-6 has been implicated as a cause of febrile illness with rash and myelosuppression, hepatitis, pneumonitis, and encephalitis after liver transplantation. In addition, HHV-6 has been associated with a variety of indirect effects such as allograft rejection, and increased predisposition and severity of other infections including cytomegalovirus (CMV), hepatitis C virus, and opportunistic fungi. Because of the uncommon nature of the clinical illnesses directly attributed to HHV-6, there is currently no recommended HHV-6-specific approach to prevention. However, ganciclovir and valganciclovir, which are primarily intended for the prevention of CMV disease, are also active against HHV-6 and may prevent its reactivation after transplantation. The treatment of established HHV-6 disease is usually with intravenous ganciclovir, cidofovir, or foscarnet, complemented by reduction in the degree of immunosuppression. This article reviews the current advances in the pathogenesis, clinical diagnosis, and therapeutic modalities against HHV6 in the setting of liver transplantation.

Unjust customer complaints are increasing, liberal redress policies are becoming more commonplace, and front line employees are expected to smile and just deal with fictitious complaints with redress and a sincere smile.  Is this justly so? This research helps to fill the current gaps in complaint, justice, and emotional labor research by empirically examining employee perceptions of perceived opportunistic versus perceived legitimate complaints.       This research completed one hotel and one restaurant study using  a 2 x 2 between-subjects experimental design to examine complaint type (opportunistic/ legitimate) and perceived organizational support (high/low).   Data was collected from a large reputable market research firm. Results find that employees from both studies experience statistically significantly lower perceptions of procedural, interactional, and distributive justice when dealing with opportunistic as opposed to legitimate complaints.  Perceptions of distributive justice statistically significantly increased employee\'s emotive effort and emotional dissonance.  Additionally, for all of the relationships in the hotel study and with distributive justice in the restaurant study, perceived organizational support had no significant effect on employee perceptions of justice or emotional dissonance or effort.   Managerial implications of employee justice perceptions and customer complaint policies are discussed. / Ph. D.

京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第19774号 / 農博第2170号 / 新制||農||1040(附属図書館) / 学位論文||H28||N4990(農学部図書室) / 32810 / 京都大学大学院農学研究科応用生命科学専攻 / (主査)教授 植田 充美, 教授 栗原 達夫, 教授 矢﨑 一史 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DFAM

No description available.

In this report, we describe a case of a 61-year-old male patient who had the bacterium growing in a blood culture. It was susceptible to ampicillin, ceftriaxone, levofloxacin, and vancomycin but was intermediately resistant to erythromycin. The patient did not have a negative outcome as a consequence of this bacterium, which retrospectively could have been predicted based on the epidemiological data within the patient's profile.

Cognitive Radio Network (CRN) is an emerging paradigm that makes use of Dynamic Spectrum Access (DSA) to communicate opportunistically, in the un-licensed Industrial, Scientific and Medical bands or frequency bands otherwise licensed to incumbent users such as TV broadcast. Interest in the development of CRNs is because of severe under-utilization of spectrum bands by the incumbent Primary Users (PUs) that have the license to use them coupled with an ever-increasing demand for unlicensed spectrum for a variety of new mobile and wireless applications. The essence of Cognitive Radio (CR) operation is the cooperative and opportunistic utilization of licensed spectrum bands by the Secondary Users (SUs) that collectively form the CRN without causing any interference to PUs' communications. CRN operation is characterized by factors such as network-wide quiet periods for cooperative spectrum sensing, opportunistic/dynamic spectrum access and non-deterministic operation of PUs. These factors can have a devastating impact on the overall throughput and can significantly increase the control overheads. Therefore, to support the same level of QoS as traditional wireless access technologies, very closer interaction is required between layers of the protocol stack. Opportunistic spectrum utilization without causing interference to the PUs is only possible if the SUs periodically sense the spectrum for the presence of PUs' signal. To minimize the effects of hardware capabilities, terrain features and PUs' transmission ranges, DSA is undertaken in a collaborative manner where SUs periodically carry out spectrum sensing in their respective geographical locations. Collaborative spectrum sensing has numerous security loopholes and can be favorable to malicious nodes in the network that may exploit vulnerabilities associated with DSA such as launching a spectrum sensing data falsification (SSDF) attack. Some CRN standards such as the IEEE 802.22 wireless regional area network employ a two-stage quiet period mechanism based on a mandatory Fast Sensing and an optional Fine Sensing stage for DSA. This arrangement is meant to strike a balance between the conflicting goals of proper protection of incumbent PUs' signals and optimum QoS for SUs so that only as much time is spent for spectrum sensing as needed. Malicious nodes in the CRN however, can take advantage of the two-stage spectrum sensing mechanism to launch smart denial of service (DoS) jamming attacks on CRNs during the fast sensing stage. Coexistence protocols enable collocated CRNs to contend for and share the available spectrum. However, most coexistence protocols do not take into consideration the fact that channels of the available spectrum can be heterogeneous in the sense that they can vary in their characteristics and quality such as SNR or bandwidth. Without any mechanism to enforce fairness in accessing varying quality channels, ensuring coexistence with minimal contention and efficient spectrum utilization for CRNs is likely to become a very difficult task. The cooperative and opportunistic nature of communication has many challenges associated with CRNs' operation. In view of the challenges described above, this dissertation presents solutions including cross-layer approaches, reputation system, optimization and game theoretic approaches to handle (1) degradation in TCP's throughput resulting from packet losses and disruptions in spectrum availability due non-deterministic use of spectrum by the PUs (2) presence of malicious SUs in the CRN that may launch various attacks on CRNs' including SSDF and jamming and (3) sharing of heterogeneous spectrum resources among collocated CRNs without a centralized mechanism to enforce cooperation among otherwise non-cooperative CRNs

We have witnessed two main trends in recent years that have shaped the current state of communication networks. First, the Internet was designed with the initial idea to provide remote access to resources in the network; today it is overwhelmingly being used for content distribution. In addition, the community of content creators has evolved from a small group of professionals into a global community where every user can generate his contents and share it with other users. Second, the proliferation of personal mobile devices, such as smartphones and media tablets, has altered the way people access, create and share information, leading to a significant migration from wired to wireless networks and raising user expectations for ubiquitous connectivity. These trends have incited research on new communication modes and in this thesis we consider a specific mode, namely opportunistic networking. Opportunistic networking is a communication paradigm that utilizes intermittent connectivity between mobile devices to enable communication in infrastructure-less environments, and to provide complementary transport mechanisms in wireless networks where infrastructure is present. The thesis focuses on two main topics: understanding and modeling human mobility, and opportunistic content distribution. Mobility modeling is one of the key issues in opportunistic networking research. First, we discuss the structure of human mobility and introduce a framework to study mobility at different behavioural levels. We propose a queuing model, denoted by meeting-point model, for pedestrian mobility in smaller urban areas, such as city squares, parks, shops or at bus stops. The model is also a contribution to the second topic we address in the thesis, since we will use it to study characteristics of content distribution in smaller areas. We envision this model as a building block in a library of analytical models that would be used to study the performance of pedestrian content distribution in common scenarios of urban mobility. Furthermore, we show how the proposed model can be used to build larger, more complex models. In the area of opportunistic content distribution, we apply both analytical and simulation-based evaluation. We empirically study the performance of epidemic content distribution by using real-life mobility traces and investigate the fitness of a homogeneous stochastic model to capture the epidemic process. In addition, we present the design, implementation and evaluation of a mobile peer-to-peer system for opportunistic networking and discuss some promising application scenarios. / <p>QC 20131115</p>

Opportunistic premise (i.e., building) plumbing pathogens (OPPPs) and antibiotic resistant bacteria are emerging microbial concerns in drinking water. OPPPs, such as Legionella pneumophila, are the leading cause of drinking water disease in many developed countries. Contributing factors include the relative success in controlling fecal pathogens, the presence of complex building plumbing systems that create habitats for OPPPs, and the relative resistance of OPPPs to disinfectants, and aging populations that are susceptible to infection. Concurrently, drinking water is increasingly being scrutinized as a potential environment that is conducive to horizontal gene transfer of antibiotic resistance genes (ARGs), selection pressure for enhanced survival of resistant bacteria, and a route of transmission of antibiotic resistant pathogens. While maintaining a disinfectant residual is an established approach to controlling OPPPs in premise plumbing, some studies have indicated that co-resistance and cross-resistance to disinfectants can increase the relative abundances of resistant bacteria and ARGs. Thus, there may be trade-offs to controlling both OPPPs and antibiotic resistance in premise plumbing that call for controlled study aimed at optimizing residual disinfection application for this purpose. A critical review of the scientific literature in Chapter 2 revealed that premise plumbing is a biologically and chemically complex environment, in which the choice of pipe material has cascading effects on water chemistry and the corresponding premise plumbing microbiome. This, in turn, has broad implications for the control of OPPPs, which need to be elucidated through controlled experiments in which worst case premise plumbing conditions are held constant (e.g., warm temperature), while other variables are manipulated. Chapter 3 introduces the convectively-mixed pipe reactors (CMPRs) as a novel low-cost, small footprint approach to replicably conduct such experiments. The CMPRs were demonstrated to effectively simulate key chemical and biological phenomena that occur in distal reaches of premise plumbing. In Chapter 4, the CMPRs were leveraged to study the interactive effects of four disinfectants (chlorine, monochloramine, chlorine dioxide, and copper-silver ionization) and three pipe materials (PVC copper, and iron). The CMPRs were inoculated with two antibiotic-resistant OPPPs: Pseudomonas aeruginosa and Acinetobacter baumannii. It was found that pipe-material (PVC or PVC combined with iron or copper) profoundly impacted the water chemistry in a manner that dictated disinfection efficacy. In Chapter 5, we applied shotgun metagenomic shotgun sequencing to evaluate effects of the combination of pipe material and disinfectant type on the wider microbial community, especially their ability to select for or reduce ARGs. In Chapter 6, we used CMPRs and metagenomic sequencing in a study comparing Dutch drinking water practices to our prior testing in an American system. Dutch drinking water is of interest because of lack of historical use of disinfectants was hypothesized to result in a microbial community that is relatively depleted of ARGs or mobile genetic elements, which can enhance spread of ARGs as disinfectants are applied. Generally, it was found that OPPPs required higher doses of disinfectants for inactivation than the general microbial community, sometimes concentrations approaching the regulatory limits in the US (e.g., 4 mg/L of total chlorine). Even successful reductions were modest, typically ~1-log, and failed to eliminate either P. aeruginosa or A. baumannii. Moreover P. aeruginosa, A. baumannii, and non-tuberculous mycobacteria varied substantially in their preference for pipe material and susceptibility to disinfectants. We found that disinfectants tended to increase the relative abundance of OPPPs, ARGs, and mobile genetic elements. Disinfectants were sometimes associated with net increases in levels of these pathogens and genes when applied at low levels (e.g., 0.1 mg/L of monochloramine), which effectively acted to reduce competition from less resistant and non-pathogenic taxa. When a low dose of monochloramine was applied to PVC CMPRs in the US, we estimated from metagenomic sequencing data that this water contained roughly 100,000 cells per milliliter of taxa known to contain pathogenic members. The Dutch drinking water exhibited more diverse microbial communities and lower relative abundances of taxa containing pathogens. ARGs were two times proportionally more abundant in CMPRs operated in the US without disinfectant than in the corresponding CMPRs operated in the Netherlands. The findings of this dissertation can help to optimize the application of in-building disinfectant addition for addressing concerns related both to OPPPs and antibiotic resistance. The studies herein highlight the necessity of developing comprehensive OPPP and antibiotic resistance control strategies that emphasize not just disinfectant dose, but other key control parameters such as contact time, hydraulics, and temperature. The functional diversity of OPPPs, antibiotic resistant bacteria, and the background premise plumbing microbiome further necessitates broad, holistic programs for monitoring and control. / Doctor of Philosophy / Efforts to provide safe drinking water face two emerging threats: the rise of pathogens that thrive in the plumbing environment that delivers water to the tap and the rise of antibiotic resistance. In the US and many other parts of the world, opportunistic pathogens are the predominant agents responsible for disease spread by tap water. Opportunistic pathogens tend to infect aged or immunocompromised individuals (hence, 'opportunistic') and grow well in in-building plumbing. Globally, antibiotic resistance is on the rise and becoming a fundamental threat to modern medicine. Pathogenic bacteria become resistant to antibiotics used to treat infections when they acquire antibiotic resistance genes (ARGs), which can happen either by mutation or from other resistant bacteria sharing ARGs. Overuse or misuse of antibiotics can impose selection pressure that stimulates horizontal gene transfer and enhance survival of bacteria that are resistant. Prior studies have suggested that under some circumstances, disinfectants used to control pathogens in drinking water can also select for antibiotic resistant bacteria. Thus, the overarching goal of this research was to optimize the type and dose of disinfectant used, depending on building-level factors such as pipe material, for effectively controlling proliferation of both opportunistic pathogens and antibiotic resistance. This dissertation largely focuses on in-building plumbing systems, which are home to potentially tens of thousands of bacterial cells per milliliter of water or per square centimeter of internal pipe surfaces. These bacteria interact not only with each other and other microbes, but also with features of the plumbing environment, such as the water chemistry or the pipe materials. Building plumbing systems are highly intricate ecosystems that can undermine the effectiveness of disinfectants provided by utilities. One major contribution of this research is the development of the convectively-mixed pipe reactors (CMPRs) as a simple and easy-to-use test system that recreates combinations of features of interest encountered in in-building plumbing. We applied the CMPRs to study two common residual disinfectants (chlorine and monochloramine) supplied by water utilities, and two other disinfectants (chlorine dioxide and copper-silver ionization) which are commonly dosed by building operators, especially in hospitals and other buildings housing individuals susceptible to infection. These four disinfectants were applied to CMPRs consisting of PVC, copper, and iron pipe. Chemical, culture, and DNA methods were used to understand how these disinfectants affected the microbes and their ecology. We then took the opportunity to set up CMPRs in the Netherlands, where there has been no historical exposure to chlorine because their water quality regulations emphasize limiting nutrients in the water and elevating the hot water line temperatures as means to control microbial growth. The CMPRs effectively produced worst-case plumbing scenarios, where opportunistic pathogens were especially difficult to control through residual disinfection. Dosed disinfectants tended to be no longer measurable in the water after five hours. The CMPRs also showed that the disinfectant most effective for one pathogen could be the least effective for another. If doses were applied near regulatory limits, the concentrations of pathogens and antibiotic resistance genes decreased. However, opportunistic pathogens tended to survive better than background populations of bacteria. Bacteria carrying ARGs also survived some disinfectant conditions better as well. Thus, if doses were applied at levels that could inactivate some microbes, but not the opportunistic pathogens, pathogen abundances sometimes increased. These results were largely confirmed in the experiment with Dutch drinking water. Here, chlorine appeared to be more problematic than monochloramine in terms of enriching pathogens and antibiotic resistance. We also noted that Dutch waters garnered more diverse microbial communities, with fewer DNA markers for pathogens and antibiotic resistance. In general, this research takes a key step towards optimizing application of residual disinfectants for control of both opportunistic pathogens and antibiotic resistance. Because disinfectants can have negative impacts on drinking water microbial communities when supplied insufficiently, it is important that the other features of in-building plumbing, such as the selection of pipe material or the hydraulics, facilitate disinfectants reaching all portions of plumbing and at the necessary concentrations. It is recommended that the selection process for disinfectant type and dose considers the plumbing materials and other conditions such that disinfection can be aimed towards controlling multiple opportunistic pathogens, which can vary in their susceptibility, and antibiotic resistance.

The theoretical frameworks of transaction cost economics and agency theory are widely used to design appropriate governance structure for constraining opportunism within marketing channels. These approaches generally assume that marketing channel managers are opportunistic, and only economic constraints deter opportunism in exchange relationships. However, some empirical studies have shown that managers do not always behave opportunistically even if conditions permit such behavior. In addition, some researchers have proposed a "cycle of self-fulfilling prophecy" and have argued that the uncritical assumption of opportunism and excessive use of control mechanisms such as monitoring only exacerbates the problem. Thus, it is important to identify conditions in which opportunism likely occurs. The present research argues that marketing channel managers exhibit differing propensities for opportunism (PFO), and it spans three levels of analysis to identify contributing factors. The individual-level analysis treats marketing channel managers as a heterogeneous population and investigates the impact of individual traits on their behaviors in business relationships. At the dyadic level, I modify standard microeconomics models to incorporate norms of fairness. Finally, the extra-dyadic level of analysis goes beyond the traditional dyadic focus to include network-wide social influence on a relationship. Using the data collected from 162 unit franchieees. the hypotheses were tested using structural path analyses. The findings of this dissertation provide guidance on the extent to which costly and potentially damaging control mechanisms are really necessary in a given marketing channel relationship. Overall, the research contributes to the existing literature by re-examining a fundamental behavioral assumption about marketing channel managers and providing an alternative framework that can meaningfully inform us as to when and why opportunism occurs. / Ph. D.