Scaling Properties of Paths on Graphs

Let $G$ be a directed graph on finitely many vertices and edges, and assign a positive weight to each edge on $G$. Fix vertices $u$ and $v$ and consider the set of paths that start at $u$ and end at $v$, self-intersecting in any number of places along the way. For each path, sum the weights of its edges, and then list the path weights in increasing order. The asymptotic behaviour of this sequence is described, in terms of the structure and type of strongly connected components on the graph. As a special case, for a Markov chain the asymptotic probability of paths obeys either a power law scaling or a weaker type of scaling, depending on the structure of the transition matrix. This generalizes previous work by Mandelbrot and others, who established asymptotic power law scaling for special classes of Markov chains.Comment: 23 pages, 2 figure

The Marketing Firm: Retailer and consumer contingencies

acceptedVersionpublishedVersio

Potential for Induced Seismicity Related to the Northern California CO2 Reduction Project Pilot Test, Solano County, California

The objective of this technical report is to analyze the potential for induced seismicity due to a proposed small-scale CO{sub 2} injection project in the Montezuma Hills. We reviewed currently available public information, including 32 years of recorded seismic events, locations of mapped faults, and estimates of the stress state of the region. We also reviewed proprietary geological information acquired by Shell, including seismic reflection imaging in the area, and found that the data and interpretations used by Shell are appropriate and satisfactory for the purpose of this report. The closest known fault to the proposed injection site is the Kirby Hills Fault. It appears to be active, and microearthquakes as large as magnitude 3.7 have been associated with the fault near the site over the past 32 years. Most of these small events occurred 9-17 miles (15-28 km) below the surface, which is deep for this part of California. However, the geographic locations of the many events in the standard seismicity catalog for the area are subject to considerable uncertainty because of the lack of nearby seismic stations; so attributing the recorded earthquakes to motion along any specific fault is also uncertain. Nonetheless, the Kirby Hills Fault is the closest to the proposed injection site and is therefore our primary consideration for evaluating the potential seismic impacts, if any, from injection. Our planned installation of seismic monitoring stations near the site will greatly improve earthquake location accuracy. Shell seismic data also indicate two unnamed faults more than 3 miles east of the project site. These faults do not reach the surface as they are truncated by an unconformity at a depth of about 2,000 feet (610 m). The unconformity is identified as occurring during the Oligocene Epoch, 33.9-23.03 million years ago, which indicates that these faults are not currently active. Farther east are the Rio Vista Fault and Midland Fault at distances of about 6 miles (10 km) and 10 miles (16 km), respectively. These faults have been identified as active during the Quaternary (last 1.6 million years), but without evidence of displacement during the Holocene (the last 11,700 years). The stress state (both magnitude and direction) in the region is an important parameter in assessing earthquake potential. Although the available information regarding the stress state is limited in the area surrounding the injection well, the azimuth of the mean maximum horizontal stress is estimated at 41{sup o} and it is consistent with strike-slip faulting on the Kirby Hills Fault, unnamed fault segments to the south, and the Rio Vista Fault. However, there are large variations (uncertainty) in stress estimates, leading to low confidence in these conclusions regarding which fault segments are optimally oriented for potential slip induced by pressure changes. Uncertainty in the stress state can be substantially reduced by measurements planned when wells are drilled at the site. Injection of CO{sub 2} at about two miles depth will result in a reservoir fluid pressure increase, which is greatest at the well and decreases with distance from the well. After the injection stops, reservoir fluid pressures will decrease rapidly. Pressure changes have been predicted quantitatively by numerical simulation models of the injection. Based on these models, the pressure increase on the Kirby Hills Fault at its closest approach to the well due to the injection of 6,000 metric tons of CO{sub 2} would be a few pounds per square inch (psi), which is a tiny fraction of the natural pressure of approximately 5,000 psi at that depth. The likelihood of such a small pressure increase triggering a slip event is very small. It is even more unlikely that events would be induced at the significantly greater depths where most of the recorded earthquakes are concentrated, because it is unlikely that such a small pressure pulse would propagate downwards any appreciable distance. Therefore, in response to the specific question of the likelihood of the CO{sub 2} injection causing a magnitude 3.0 (or larger) event, this preliminary analysis suggests that no such induced or triggered events would be expected. However, it is possible that a fault, too small to be detected by the existing seismic data, yet sufficiently large to cause a magnitude 3 event, could exist in close proximity to the injection point where the pressure increase could cause slippage. However, the existence of such a fault would be detectable in the data planned for collection from the well prior to injection. We do note that natural earthquake events of up to 3.7 in magnitude have occurred in this area and would be expected to occur again regardless of the proposed CO{sub 2} injection

Presence of Acinetobacter species among the predominant bacteria found in a contaminated metal-working fluid

The distribution of Acinetobacter species among the bacteria isolated from an unusually heavily contaminated petroleum-based water-soluble metal-working fluid used in a large North American automotive machining operation was investigated. It had been found previously1 that, in laboratory cultures with metal-working fluids as the sole carbon source, these species grew more rapidly and to much higher densities than any other types of bacteria isolated from this system. Thus, it was expected that they would dominate the population and would be difficult to control. It is shown here that, contrary to expectation, over a one-year period Acinetobacter species usually accounted for only a few percent of the total population. Factory fluids did not contain substances that selectively inhibited the growth of these species. In mixed-cultures grown in the laboratory with metal-working fluid as the carbon source, Acinetobacter species accounted for less than 1% in the initial inocolum, nearly 70% during the mid-exponential-phase, and only a few percent in the stationary-phase. These experiments suggest, as a working hypothesis, that the Acinetobacter species `govern' the contamination in the sense that they first colonize the fluid and their presence is necessary to maintain the other strains.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/26622/1/0000163.pd

The marketing firm and co‐creation: An empirical study of marketer and customer's co‐creation process

This study empirically investigates the marketer and customer's co‐creation process within the context of the marketing firm. Based on principles from bilateral contingencies, findings from a conjoint study (n = 98) indicate that utilitarian and informational reinforcing consequences from the marketer have a stronger impact on customers' co‐creation behavior relative to informational reinforcing consequences from other customers. Consequently, analyzing the impact of important reinforcing contingencies through the lens of bilateral contingencies expands our understanding of how and why co‐creation outcomes might occur. Also, a good co‐creation process may increase the business companies' research and intelligence and, as a consequence, strengthen their competitiveness.The marketing firm and co‐creation: An empirical study of marketer and customer's co‐creation processacceptedVersio

Human naïve regulatory T-cells feature high steady-state turnover and are maintained by IL-7

Naïve FoxP3-expressing regulatory T-cells (Tregs) are essential to control immune responses via continuous replenishment of the activated-Treg pool with thymus-committed suppressor cells. The mechanisms underlying naïve-Treg maintenance throughout life in face of the age-associated thymic involution remain unclear. We found that in adults thymectomized early in infancy the naïve-Treg pool is remarkably well preserved, in contrast to conventional naïve CD4 T-cells. Naïve-Tregs featured high levels of cycling and pro-survival markers, even in healthy individuals, and contrasted with other circulating naïve/memory CD4 T-cell subsets in terms of their strong γc-cytokine-dependent signaling, particularly in response to IL-7. Accordingly, ex-vivo stimulation of naïve-Tregs with IL-7 induced robust cytokine-dependent signaling, Bcl-2 expression, and phosphatidylinositol 3-kinase (PI3K)-dependent proliferation, whilst preserving naïve phenotype and suppressive capacity. Altogether, our data strongly implicate IL-7 in the thymus-independent long-term survival of functional naïve-Tregs, and highlight the potential of targeting the IL-7 pathway to modulate Tregs in different clinical settings.This work was supported by Fundação para a Ciência e Tecnologia (FCT; POCI2010/IC/83068/2007 to RMMV; PTDC/SAU-MIC/109786/2009 to AES), and Gulbenkian Foundation (96526/2009 to JF; P132532/2013 to AES). SLS, ASA, RBF, ARP, PM and SMF received FCT scholarships

The theory of the marketing firm

The theory of the marketing firm locates the rationale of the modern business enterprise that lies in its responding profitably to the imperatives of marketing orientation. Economic theories of the firm generally fail to recognize these imperatives, enhanced consumer choice and sophistication, which entail marketing orientation as the rationale of the firm. The paper propose a competence theory of the firm as a metacontingency and examines the bilateral contingencies by which firms link to their consumerates, which indicate their capacities for customer orientation. The marketing firm emerges as a means of encapsulating entrepreneurship, economizing on transaction costs, and enabling the management of marketing specialization

Effective risk relievers for dimensional perceived risks on mail-order purchase: a case study on speciality foods in the UK

This article examines the effective risk relievers for different dimensions of perceived risk on mail-order purchase of food products. The sample comprised 1,600 active and inactive mail-order specialty food shoppers in the UK. The analysis focused on the correlation coefficients between consumers' levels of perceived risk and their weight on the importance of the risk relievers. Amongst 15 risk relievers, the results implied that there are certain risk relievers attached to higher levels of importance by consumers, who perceive higher levels of risks in certain aspects of mail-order purchase. Therefore, mail-order companies should promote the effective risk relievers to reduce specific dimensions of perceived risks

SMEs' purchasing habits : A procurement maturity model for stakeholders

Although micro companies overpower the small and medium enterprise (SME) segment, generalizations are often with medium size companies, and therefore, there are many unknowns, especially when it comes to its buying behavior. Conformist studies and industry practices assume SMEs to be “normative” or “conservative” buyers; however, this hypothesis is untested. This article aims to scrutinize the reality, and proposes a unified model that rejects pre-containerization in buying behavior typologies, as well as selectiveness in terms of audience type, whether it is corporate, SME, or consumer. While replacing researchers’ perceptions with the audience’s, the model yields actual knowledge that can lead to audience’s beliefs in lieu of the opposite, which is used to mislead stakeholders. The study shows that SMEs also buy like individuals and spend in a similar way to consumers’, including not only “normative” and “conservative” but also “negligent” and “impulse” zones. From the research-implications perspective, future studies by behaviorists can explore why SMEs purchase in this way. Marketers may benefit from the finding that SMEs buy like individuals. In addition, SMEs may want to be conscious of their purchasing habits, and—utilizing the newly introduced “risk score” frontier—policymakers should assess the consequences of these habits at the macro level