LLukas22/scidocs huggingface dataset:
Phase-type distribution of customer relationship with Markovian response and marketing expenditure decision on the customer lifetime value

In recent years, more and more companies have adopted relationship marketing (RM). At the core of RM is the development and maintenance of long-term relationships with valuable customers. In RM, the customer lifetime value (CLV) is the discounted profit streams of a customer across the entire customer life cycle. The CLV plays a key role in customer acquisition and retention decisions. In this paper, we present a general mathematical framework for RM, and introduce a Markov chain model which is appropriate in modeling RM because of its flexibility and probabilistic nature. We also develop the life distribution of the customer relationship, which is a phase-type distribution since it is the distribution of the first arrival stopping state. And we obtain the expectation of the CLV, which is an important statistic for good decision-making. Finally, we illustrate how to find the optimal remarketing policy numerically. The framework developed for RM systems in this paper should be seen as a practical approach to RM where one can directly apply the results of phasetype distribution and expectation of CLV to marketing decisions. 2007 Elsevier B.V. All rights reserved.
Breast milk pharmacokinetics of efavirenz and breastfed infants' exposure in genetically defined subgroups of mother-infant pairs: an observational study.

BACKGROUND
The antiretroviral drug efavirenz is widely used during breastfeeding. Evaluating its safety requires an understanding of its breast milk pharmacokinetics, level of breastfed infants' exposure, and potential influence of polymorphisms in drug disposition genes.


METHODS
For this observational study, we investigated plasma and breast milk pharmacokinetics of efavirenz and breastfed infants' exposure in human immunodeficiency virus positive nursing mothers and their breastfed infants. We also evaluated potential variability due to genetic polymorphisms in CYP2B6, NR1I3, CYP2A6, ABCB1, ABCB5, and ABCG2.


RESULTS
CYP2B6 516G>T was independently associated with efavirenz concentrations in maternal plasma, breast milk, and infant plasma (n = 134). When stratified based on CYP2B6 516G>T (n = 29 ; 11 GG, 10 GT and 8 TT), efavirenz pharmacokinetic parameters in plasma and breast milk differed significantly between patient groups. The median time-averaged milk-to-plasma concentration ratio was 1.10 (range: 0.57-1.71). The estimated maximum infant efavirenz dose from breast milk was 809 µg/kg/day (215-2760) and pediatric dose weight-adjusted exposure index was 4.05% (1.08-13.8). Infant plasma concentrations did not change significantly during the dosing interval, 157 ng/mL (28.6-1360) in pooled analysis and 315 ng/mL (108-1360) in CYP2B6 516TT group. Infant plasma concentrations were highest up to 8 days of age at 1590 ng/mL (190-4631) and decreased by about 90% in the age stratum day 9 to 3 months. No efavirenz related toxicity was reported.


CONCLUSIONS
Most breastfed infants are exposed to <10% of the weight-adjusted therapeutic pediatric dose, the safety threshold for exposure to maternal drugs from breast milk.
Blockchain distributed ledger technologies for biomedical and health care applications

Objectives
To introduce blockchain technologies, including their benefits, pitfalls, and the latest applications, to the biomedical and health care domains.


Target Audience
Biomedical and health care informatics researchers who would like to learn about blockchain technologies and their applications in the biomedical/health care domains.


Scope
The covered topics include: (1) introduction to the famous Bitcoin crypto-currency and the underlying blockchain technology; (2) features of blockchain; (3) review of alternative blockchain technologies; (4) emerging nonfinancial distributed ledger technologies and applications; (5) benefits of blockchain for biomedical/health care applications when compared to traditional distributed databases; (6) overview of the latest biomedical/health care applications of blockchain technologies; and (7) discussion of the potential challenges and proposed solutions of adopting blockchain technologies in biomedical/health care domains.
Pre-Partum Diet of Adult Female Bearded Seals in Years of Contrasting Ice Conditions

Changing patterns of sea-ice distribution and extent have measurable effects on polar marine systems. Beyond the obvious impacts of key-habitat loss, it is unclear how such changes will influence ice-associated marine mammals in part because of the logistical difficulties of studying foraging behaviour or other aspects of the ecology of large, mobile animals at sea during the polar winter. This study investigated the diet of pregnant bearded seals (Erignathus barbatus) during three spring breeding periods (2005, 2006 and 2007) with markedly contrasting ice conditions in Svalbard using stable isotopes (δ(13)C and δ(15)N) measured in whiskers collected from their newborn pups. The δ(15)N values in the whiskers of individual seals ranged from 11.95 to 17.45 ‰, spanning almost 2 full trophic levels. Some seals were clearly dietary specialists, despite the species being characterised overall as a generalist predator. This may buffer bearded seal populations from the changes in prey distributions lower in the marine food web which seems to accompany continued changes in temperature and ice cover. Comparisons with isotopic signatures of known prey, suggested that benthic gastropods and decapods were the most common prey. Bayesian isotopic mixing models indicated that diet varied considerably among years. In the year with most fast-ice (2005), the seals had the greatest proportion of pelagic fish and lowest benthic invertebrate content, and during the year with the least ice (2006), the seals ate more benthic invertebrates and less pelagic fish. This suggests that the seals fed further offshore in years with greater ice cover, but moved in to the fjords when ice-cover was minimal, giving them access to different types of prey. Long-term trends of sea ice decline, earlier ice melt, and increased water temperatures in the Arctic are likely to have ecosystem-wide effects, including impacts on the forage bases of pagophilic seals.
Political , economic and environmental impacts of biofuels : A review

Current energy policies address environmental issues including environmentally friendly technologies to increase energy supplies and encourage cleaner, more efficient energy use, and address air pollution, greenhouse effect, global warming, and climate change. The biofuel policy aims to promote the use in transport of fuels made from biomass, as well as other renewable fuels. Biofuels provide the prospect of new economic opportunities for people in rural areas in oil importer and developing countries. The central policy of biofuel concerns job creation, greater efficiency in the general business environment, and protection of the environment. Projections are important tools for long-term planning and policy settings. Renewable energy sources that use indigenous resources have the potential to provide energy services with zero or almost zero emissions of both air pollutants and greenhouse gases. Biofuels are expected to reduce dependence on imported petroleum with associated political and economic vulnerability, reduce greenhouse gas emissions and other pollutants, and revitalize the economy by increasing demand and prices for agricultural products. 2009 Elsevier Ltd. All rights reserved.
A histological examination of grafting success in pearl oyster Pinctada margaritifera in French Polynesia

Pearl oyster grafting is a complex surgical operation that should lead to pearl formation after approximately eighteen months. Although this technique has been used for many years in French Polynesia, the grafting process is still not standardised. While studies have been carried out in order to improve graft performance and yield, these remain highly variable due to post-grafting mortality, nucleus rejection and unreliable pearl quality, all of which constrain pearl farm profitability. The present study uses histological analysis to monitor oysters that either rejected or retained their nuclei. Both groups of oysters are compared in terms of evolution of the graft, which could influence retention, and the development of a pearl sac in cases where grafting was successful. Data show that rejection phenomena are linked to a number of causes, notably an inflammatory reaction in the “receiving” oyster, the presence of numerous tissue lesions and the quality of the grafted tissue. These results suggest that study is needed on the different concomitant elements of the grafting process: the graft “donor” oysters, the nucleus and the “receiving” oyster and their interactions.
Modeling and toolpath generation for consumer-level 3d printing

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Assessment of burden in partners of stroke patients with the sense of competence questionnaire.

BACKGROUND AND PURPOSE
The burden of caregiving can be harmful to both carers' and patients' functional health, but a specific instrument to assess the burden of caregiving as experienced by carers of stroke patients is not yet available. The Sense of Competence Questionnaire (SCQ), reliable and valid among caregivers of dementia patients, was evaluated on its metric properties in a population of partners of stroke patients.


METHODS
As part of a multicenter study on quality of care, SCQ burden scores of partners and functional health of patients were assessed 6 months after stroke (group A; n=166). In this study group, the reliability in terms of homogeneity, the construct validity, and the clinical validity of the SCQ were evaluated. The test-retest reliability was assessed in a separate group (group B; n=47). The feasibility was examined in both study groups.


RESULTS
The reliability of the total SCQ score was good (Chronbach's alpha coefficient=0.83; intraclass correlation coefficient=0.93). Statistical support for construct validity was shown by principal-components analysis. Clinical validity was supported by the association between higher SCQ burden scores and patients' impaired functional health: cognitive function (P=.03), disability (P=.10), handicap (P<.01), and quality of life (P=.02).


CONCLUSIONS
The SCQ is a reliable and valid instrument for assessing burden of caregiving as experienced by partners of stroke patients. It is suitable for use in cross-sectional stroke studies and may help to identify partners at risk for high levels of burden and caregiving-related problems.
Health Care Organizations as Complex Adaptive Systems

From its roots in physics, mathematics, and biology, the study of complexity science, or complex adaptive systems, has expanded into the domain of organizations and systems of organizations. Complexity science is useful for studying the evolution of complex organizations -entities with multiple, diverse, interconnected elements. Evolution of complex organizations often is accompanied by feedback effects, nonlinearity, and other conditions that add to the complexity of existing organizations and the unpredictability of the emergence of new entities. Health care organizations are an ideal setting for the application of complexity science due to the diversity of organizational forms and interactions among organizations that are evolving. Too, complexity science can benefit from attention to the world’s most complex human organizations. Organizations within and across the health care sector are increasingly interdependent. Not only are new, highly powerful and diverse organizational forms being created, but also the restructuring has occurred within very short periods of time. In this chapter, we review the basic tenets of complexity science. We identify a series of key differences between the complexity science and established theoretical approaches to studying health organizations, based on the ways in which time, space, and constructs are framed. The contrasting perspectives are demonstrated using two case examples drawn from healthcare innovation and healthcare integrated systems research. Complexity science broadens and deepens the scope of inquiry into health care organizations, expands corresponding methods of research, and increases the ability of theory to generate valid research on complex organizational forms. Formatted
Improving Recruitment of surgical trainees and Training of Surgeons in Uganda

Background: The surgical work output in Uganda is qualitatively and quantitatively inadequate. The number of surgeons is estimated at 100 for a population of over 26 million Ugandans. This paper reports on how to improve recruitment of surgical trainees and training of surgeons in Uganda, focusing on perceptions of potential trainees, trainers, and medical administrators. Methods: This was cross sectional, descriptive study sampled at least 50% of each of the relevant category of interviewees. Self-administered questionnaire and focus group discussions were used to collect data, which was analyzed manually using a master sheet. It was approved by the Ethics and Research Committee. Results: Paediatrics and Public Health were rated as the disciplines of choice for postgraduate training in Uganda. The reasons why potential trainees would shy away from specialized surgical training were excessive workload, risk of catching HIV/AIDS, low financial returns and a poor learning environment. The major bottlenecks in surgical training, which were cited, included inadequate number of scholarships, inadequate supervision by trainers, inadequate facilities and poor work conditions for trainers. Conclusion: The remedies to this complex problem revolve round providing more resources, (human, materials, money), improving supervision by the trainers, advocacy for an evidence based curriculum content and availing more funding into the Medical Education sector to improve Human Resource for Health development.
A block coordinate gradient descent method for regularized convex separable optimization and covariance selection

We consider a class of unconstrained nonsmooth convex optimization problems, in which the objective function is the sum of a convex smooth function on an open subset of matrices and a separable convex function on a set of matrices. This problem includes the covariance selection estimation problem that can be expressed as an `1-penalized maximum likelihood estimation problem. In this paper, we propose a block coordinate gradient descent method (abbreviated as BCGD) for solving this class of nonsmooth separable problems with the coordinate block chosen by a GaussSeidel rule. The method is simple, highly parallelizable, and suited for large-scale problems. We establish global convergence and, under a local Lipschizian error bound assumption, linear rate of convergence for this method. For the covariance selection estimation problem, the method can terminate in O(n3/2) iterations with an 2-optimal solution. We compare the performance of the BCGD method with first-order methods studied in [11, 12] for solving the covariance selection problem on randomly generated instances. Our numerical experience suggests that the BCGD method can be efficient for large-scale covariance selection problems with constraints.
Valuation of travel time reliability from a GPS-based experimental design

Keywords: Time reliability GPS Route choice Random utility I-394 HOT MnPass Mixed logit Bootstrap a b s t r a c t In the Minneapolis–St. Paul region (Twin Cities), the Minnesota Department of Transportation (MnDOT) converted the Interstate 394 High Occupancy Vehicle (HOV) lanes to High Occupancy Toll (HOT) lanes (or MnPASS Express Lanes). These lanes allow single occupancy vehicles (SOVs) to access the HOV lanes by paying a fee. This fee is adjusted according to a dynamic pricing system that varies with the current demand. This paper estimates the value placed by the travelers on the HOT lanes because of improvements in travel time reliability. This value depends on how the travelers regard a route with predictable travel times (or small travel time variability) in comparison to another with unpredictable travel times (or high travel time variability). For this purpose, commuters are recruited and equipped with Global Positioning System (GPS) devices and instructed to commute for two weeks on each of three plausible alternatives between their home in the western suburbs of Minneapolis eastbound to work in downtown or the University of Minnesota: I-394 HOT lanes, I-394 General Purpose lanes (untolled), and signalized arterials close to the I-394 corridor. They are then given the opportunity to travel on their preferred route after experiencing each alternative. This revealed preference data is then analyzed using discrete choice models of route. Three measures of reliability are explored and incorporated in the estimation of the models: standard deviation (a classical measure in the research literature); shortened right range (typically found in departure time choice models); and interquartile range (75th–25th per-centile). Each of these measures represents distinct ways about how travelers deal with different sections of reliability. In all the models, it was found that reliability was valued highly (and statistically significantly), but differently according to how it was defined. The estimated value of reliability in each of the models indicates that commuters are willing to pay a fee for a reliable route depending on how they value their reliability savings. The issue of travel time reliability is becoming more critical to users of transportation networks. Historically, research on route choice behavior focused on expected travel time without consideration of its variability. However, surface transportation networks have matured in developed nations. This situation has been characterized by an inability to increase network capacity with additional links or lanes, because of small benefit-cost ratios (none …
Does Economic Growth Reduce Corruption ? Theory and Evidence from Vietnam ∗

Government corruption is more prevalent in poor countries than in rich countries. This paper uses cross-industry heterogeneity in growth rates within Vietnam to test empirically whether growth leads to lower corruption. We find that it does. We begin by developing a model of government officials’ choice of how much bribe money to extract from firms that is based on the notion of inter-regional tax competition, and consider how officials’ choices change as the economy grows. We show that economic growth is predicted to decrease the rate of bribe extraction under plausible assumptions, with the benefit to officials of demanding a given share of revenue as bribes outweighed by the increased risk that firms will move elsewhere. This effect is dampened if firms are less mobile. Our empirical analysis uses survey data collected from over 13,000 Vietnamese firms between 2006 and 2010 and an instrumental variables strategy based on industry growth in other provinces. We find, first, that firm growth indeed causes a decrease in bribe extraction. Second, this pattern is particularly true for firms with strong land rights and those with operations in multiple provinces, consistent with these firms being more mobile. Our results suggest that as poor countries grow, corruption could subside “on its own,” and they demonstrate one type of positive feedback between economic growth and good institutions. ∗Contact information: Bai: jieb@mit.edu; Jayachandran: seema@northwestern.edu; Malesky: ejm5@duke.edu; Olken: bolken@mit.edu. We thank Lori Beaman, Raymond Fisman, Chang-Tai Hsieh, Supreet Kaur, Neil McCulloch, Andrei Shleifer, Matthew Stephenson, Eric Verhoogen, and Ekaterina Zhuravskaya for helpful comments.
Process Modeling

• Business process reengineering-the redesign of an organization's business processes to make them more efficient. • Coordination technology-an aid to managing dependencies among the agents within a business process, and provides automated support for the most routinized component processes. * Process-driven software development environments-an automated system for integrating the work of all software related management and staff; it provides embedded support for an orderly and defined software development process. These three applications share a growing requirement to represent the processes through which work is accomplished. To the extent that automation is involved, process representation becomes a vital issue in redesigning work and allocating responsibilities between humans and computers. This requirement reflects the growing use of distributed , networked systems to link the interacting agents responsible for executing a business process. To establish process modeling as a unique area, researchers must identify conceptual boundaries that distinguish their work from model-ing in other areas of information science. Process modeling is distinguished from other types of model-ing in computer science because many of the phenomena modeled must be enacted by a human rather than a machine. At least some mod-eling, however, in the area of human-machine system integration or information systems design has this 'human-executable' attribute. Rather than focusing solely on the user's behavior at the interface or the flow and transformation of data within the system, process model-ing also focuses on interacting behaviors among agents, regardless of whether a computer is involved in the transactions. Much of the research on process modeling has been conducted on software development organizations , since the software engineering community is already accustomed to formal modeling. Software process modeling, in particular , explicitly focuses on phenomena that occur during software creation and evolution, a domain different from that usually mod-eled in human-machine integration or information systems design. Software development is a challenging focus for process modeling because of the creative problem-solving involved in requirements analysis and design, and the coordination of team interactions during the development of a complex intellectual artifact. In this article, software process modeling will be used as an example application for describing the current status of process modeling, issues for practical use, and the research questions that remain ahead. Most software organizations possess several yards of software life cycle description, enough to wrap endlessly around the walls of project rooms. Often these descriptions do not correspond to the processes actually performed during software …