A non-standard approach to a market with boundedly rational consumers and strategic firms. Part I: A microfoundation for the evolution of sales

In our model, individual consumers follow simple behavioral decision rules based on imitation and habit as suggested in consumer research, social learning, and related fields. Demand can be viewed as the outcome of a population game whose revision protocol is determined by the consumers' behavioral rules. The consumer dynamics are then analyzed in order to explore the demand side and first implications for a strategic supply side.bounded rationality, social learning, population game, mean dynamic

Product Pricing when Demand Follows a Rule of Thumb

We analyze the strategic behavior of firms when demand is determined by a rule of thumb behavior of consumers. We assume consumer dynamics where individual consumers follow simple behavioral decision rules governed by imitation and habit as suggested in consumer research. On this basis, we investigate monopoly and competition between firms, described via an open-loop differential game which in this setting is equivalent to but analytically more convenient than a closed-loop system. We derive a Nash equilibrium and examine the influence of advertising. We show for the monopoly case that a reduction of the space of all price paths in time to the space of time-constant prices is sensible since the latter in general contains Nash equilibria. We prove that the equilibrium price of the weakest active firm tends to marginal cost as the number of (non-identical) firms grows. Our model is consistent with observed market behavior such as product life cycles.bounded rationality, social learning, population game, differential game, product life cycle, monopoly, competition, pricing, advertising

Risikofaktoren beim Morbus Perthes und ihre Auswirkungen auf das klinische und radiologische Ergebnis

In den Jahren 1984 bis 2001 wurden 94 Patienten im Klinikum für Orthopädie der Universität Marburg aufgrund eines Morbus Perthes therapiert. Das Ziel der vorliegenden Arbeit war es, retrospektiv prognostisch wertvolle Faktoren aus der Erkrankungsphase, die so genannten Risikofaktoren, zu eruieren und deren Effekt auf die mittelfristigen klinischen und radiologischen Ergebnisse zu überprüfen. Das Patientengut bestand aus 84 Jungen und 10 Mädchen. Eine beidseitige Erkrankung lag bei 10 Patienten vor. Das chronologische Alter zum Zeitpunkt der Ersterkrankung betrug durchschnittlich 7,19 Jahre. Fünf Patienten (6,49%) zeigten eine familiäre Häufung der Erkrankung. Die Mehrzahl der Patienten wurde operativ therapiert, vorwiegend mittels Intertrochantärer Varisationsosteotomie oder einer Beckenosteotomie nach Chiari bzw. Salter, und einige erhielten eine konservative Behandlung. Eine Beinlängendifferenz von 1 bis 3,5 cm war lediglich bei 14 Patienten festzustellen (17,8%). Schwerwiegende Komplikationen (Adduktionskontraktur, Osteochondrosis dissecans) im Rahmen der Therapie gehörten zu den wenigen Ausnahmefällen. Deformitäten nach Ausheilung der Erkrankung waren selten. Es wurden 75 (79,8% des gesamten Patientengutes) Patienten anhand klinisch anerkannter Hip Scores nachuntersucht. Seit dem Zeitpunkt der Diagnosestellung waren durchschnittlich 8,34 Jahre vergangen und das mittlere Alter zum Zeitpunkt der Nachuntersuchung lag bei 15,07 Jahren. Der Harris Hip Score zeigte bei 73 Patienten (97,3%) exzellente Ergebnisse und lediglich in einem Fall ein gutes und in einem weiteren Fall ein befriedigendes Ergebnis. Auch der Hip Score nach Merle d’Aubigné und Postel ergab vorwiegend sehr gute Werte. So erreichten 72 Patienten (96%) ein sehr gutes, zwei Patienten ein mittleres und ein Patient ein schlechtes Ergebnis. Es war keine Beziehung zwischen beiden angewandten Hip Scores und dem Schweregrad der Erkrankung feststellbar. Von 74 Patienten konnte der Verlauf und das Endergebnis anhand von Röntgenbildern ausgewertet werden. Das Ausmaß des Hüfkopfbefalls wurde mithilfe der Klassifikationen nach Catterall, Salter-Thompson bzw. Herring und das Outcome mittels Mose- und Stulberg-Klassifikation beurteilt. Das Vorhandensein der radiologischen Risikozeichen Gage’s sign und metaphysäre Beteiligung (inklusive Anzahl und Volumen der Zysten) wurden überprüft. Nach einer umfassenden Analyse der Risikofaktoren, nahmen wir eine Einteilung in klinische (Weibliches Geschlecht, Alter > 6 Jahre, Familiäre Häufung und Bilateralität) und radiologische Risikofaktoren (hohes Stadium nach Catterall, Salter-Thompson bzw. Herring, Vorhandensein des Gage’s sign und metaphysäre Beteiligung mit Anzahl und Volumen der Zysten) vor und kontrollierten deren Zusammenhang mit einem schlechten Endergebnis nach Mose und Stulberg. Bei näherer Betrachtung der klinischen Risikofaktoren, erwies sich das Alter als besonders wertvolles Kriterium im Hinblick auf die Prognose, denn unsere Patienten mit Ersterkrankungsalter über 9 Jahren entwickelten häufiger entrundete, asphärische Hüftgelenke im Vergleich zu den Patienten unter 6 Jahren. So zeigten die Älteren in 84,6% der Fälle schlechte Ergebnisse mit endrundeten Hüftköpfen nach Mose-Klassifikation (verglichen mit 28,6% der Jüngeren) und laut Stulberg ergab sich bei den Älteren in 16,7% ein Typ 3 mit asphärischer Inkongruenz und der Gefahr der schweren Arthroseentwicklung vor dem 50. Lebensjahr (wohingegen die Jüngeren alle ein kongruentes Hüftgelenk erreichen konnten). Die genauere Untersuchung der Risikogruppen Weibliches Geschlecht bzw. bilateral befallene Patienten zeigte zwar erwartungsgemäß, daß Mädchen bzw. beidseits Erkrankte zu schlechteren Endergebnissen tendierten als die Jungen bzw. die einseitig Erkrankten, es konnte für diese beiden Risikofaktoren jedoch keine Signifikanz ermittelt werden. Die Patienten mit nachgewiesener familiärer Häufung der Erkrankung zeigten wider Erwarten sehr gute klinische und radiologische Endergebnisse, was gegen eine Benachteiligung dieser Patienten spricht. Hinsichtlich der radiologischen Risikofaktoren ergab sich eine gute Korrelation der hohen Catterall-, Salter-Thompson- bzw. Herring-Stadien, die einen ausgeprägten Hüftkopfbefall anzeigen, mit einem schlechten Outcome nach Mose und Stulberg. Patienten mit radiologisch nachweisbarem Gage’s sign bzw. metaphysärer Beteiligung waren etwas häufiger von einem schlechten Ergebnis betroffen als Erkrankte ohne diese Risikozeichen, es ließen sich allerdings keine signifikanten Unterschiede feststellen. Insgesamt läßt sich zusammenfassen, daß bei unserem Patientengut vor allem ein Ersterkrankungsalter von über 9 Jahren und ein hohes Ausmaß des Hüftkopfbefalls eine gute Korrelation mit einem schlechten Ergebnis zeigte, weshalb diese beiden Risikofaktoren für eine verläßliche Beurteilung der Prognose geeignet zu sein scheinen

Autophagy coordinates chondrocyte development and early joint formation in zebrafish

Autophagy is a catabolic process responsible for the removal of waste and damaged cellular components by lysosomal degradation. It plays a key role in fundamental cell processes, including ER stress mitigation, control of cell metabolism, and cell differentiation and proliferation, all of which are essential for cartilage cell (chondrocyte) development and survival, and for the formation of cartilage. Correspondingly, autophagy dysregulation has been implicated in several skeletal disorders such as osteoarthritis and osteoporosis. To test the requirement for autophagy during skeletal development in zebrafish, we generated an atg13 CRISPR knockout zebrafish line. This line showed a complete loss of atg13 expression, and restricted autophagic activity in vivo. In the absence of autophagy, chondrocyte maturation was accelerated, with chondrocytes exhibiting signs of premature hypertrophy. Focussing on the jaw element, autophagy disruption affected joint articulation causing restricted mouth opening. This gross behavioural phenotype corresponded with a failure to thrive, and death in homozygote atg13 nulls within 17 days. Taken together, our results are consistent with autophagy contributing to the timely regulation of chondrocyte maturation and for extracellular matrix formation

Differential Relationships Between Waist Circumference and Cardiorespiratory Fitness Among People With and Without Type 2 Diabetes

Adults with type 2 diabetes mellitus tend to exhibit an increased level of central adiposity, augmenting their risk of further non-communicable diseases (NCDs). Importantly, consistent evidence demonstrates a significant, negative association between cardiorespiratory fitness (CRF) and waist circumference (WC). However, no previous studies have investigated differences in these CRF-related reductions in WC between adults with and without diabetes. This study used data from the Aerobic Center for Longitudinal Studies, conducted between 1970 and 2006 among predominately Non-Hispanic White, middle-to-upper class adults in Texas. Quantile regression models were used to estimate CRF-related differences in WC between persons with and without diabetes. Age, height, smoking status and birth cohort served as covariates. The analytic sample included 45901 adults. Significantly larger reductions in WC were observed among adults with diabetes as compared to without diabetes across all WC percentiles. Among males, high CRF levels were associated with significant reductions, as compared to their low-fit counterparts, in WC as large as 21.9 cm for adults without diabetes and as large as 27 cm for adults with diabetes. Among females, high CRF levels were associated with significant reductions, as compared to their low-fit counterparts, in WC as large as 22.3 and 30.0 cm for adults without and with diabetes, respectively. This study demonstrated that higher CRF is associated with significant reductions in WC, with greater magnitudes found among adults with diabetes, especially among the most centrally obese, highlighting the necessity of exercise prescription in this clinical population potentially leading to lower risks of future NCDs

Smoking Cessation Program for Inpatients with Substance Use Disorder: A Quasi-Randomized Controlled Trial of Feasibility and Efficacy

Aims: The present study investigated the feasibility, acceptance and efficacy of a newly developed cognitive behavioral program for smoking cessation/reduction ('Rethink your Smoking' program, RSP) in inpatients with substance use disorder (SUD). Method: One hundred ninety-nine inpatients with SUD were randomly assigned to either the RSP (n = 101) or a minimal intervention (MI) program (n = 98). In addition, participants were offered optional nicotine replacement therapy. Data from a group of patients with SUD without any intervention (control group, n = 78) were included in the analyses for comparison. Assessments were performed at admission, discharge and follow-up after 3 and 6 months. Results: RSP proved to be feasible and was well accepted by participants. Patients in both interventions showed lower scores for physical nicotine dependence and number of cigarettes smoked per day and higher scores for various motivational parameters at discharge and 3 months later. Both interventions were superior to no intervention, but no differences were found between the RSP and MI. Conclusion: A smoking cessation/reduction program is feasible for substance-dependent in-patients undergoing detoxification. Although the RSP appears to be effective in terms of harm reduction in in-patients with SUD, more cost-and time-efficient programs might also be suitable for this population. (C) 2016 S. Karger AG, Base

Integrating Student Assistants into Digital Repository Workflows: Challenges and Best Practices

The Scholarly Communication Initiatives and Digital Collections departments within the University of Nevada, Las Vegas adapted staff workflows to become student-centered, where workers create digital content for the University Libraries’ digital repositories. Each department has a diverse set of needs; Scholarly Communication Initiatives hires students to help with the creation of metadata records, review open access options for sharing each work, and upload items into the institutional repository. Digital Collections relies on students to scan, create metadata, and upload images online that reflect physical holdings in Special Collections and Archives. Utilizing student workers also provides more time for full-time staff to work on higherlevel projects and to update, rethink, improve, and streamline existing workflows. Both departments have found that student-centered workflows teach technical and transferable skills while also encouraging students to grow professionally, academically, and socially, setting students up for success beyond graduation. Empowering the whole student and encouraging their personal and collaborative growth thus helps each department to become more efficient and successful in their missions, a triumph that is possible for any library department of an academic institution. While there is a large body of research on student workers in libraries, including on the topics of management and specific functional areas, there is very little research focused on student workers in digital repositories. This article begins to fill this gap and discusses the philosophies and methodologies of both departments’ approaches, as well as the results of implementing student-centered processes for the department and full-time staff

Toward a Dimensional Assessment of Externalizing Disorders in Children: Reliability and Validity of a Semi-Structured Parent Interview

Objective This study assesses the reliability and validity of the DSM-5-based, semi-structured Clinical Parent Interview for Externalizing Disorders in Children and Adolescents (ILF-EXTERNAL). Method Participant data were drawn from the ongoing ESCAschool intervention study. The ILF-EXTERNAL was evaluated in a clinical sample of 474 children and adolescents (aged 6-12 years, 92 females) with symptoms of attention-deficit/hyperactivity disorder (ADHD). To obtain interrater reliability, the one-way random-effects, absolute agreement models of the intraclass correlation (ICC) for single ICC(1,1) and average measurements ICC(1,3) were computed between the interviewers and two independent raters for 45 randomly selected interviews involving ten interviewers. Overall agreement on DSM-5 diagnoses was assessed using Fleiss' kappa. Further analyses evaluated internal consistencies, item-total correlations as well as correlations between symptom severity and the degree of functional impairment. Additionally, parents completed the German version of the Child Behavior Checklist (CBCL) and two DSM-5-based parent questionnaires for the assessment of ADHD symptoms and symptoms of disruptive behavior disorders (FBB-ADHS; FBB-SSV), which were used to evaluate convergent and divergent validity. Results ICC coefficients demonstrated very good to excellent interrater reliability on the item and scale level of the ILF-EXTERNAL [scale level: ICC(1,1) = 0.83-0.95; ICC(1,3) = 0.94-0.98]. Overall kappa agreement on DSM-5 diagnoses was substantial to almost perfect for most disorders (0.38 ≤ κ ≤ 0.94). With some exceptions, internal consistencies (0.60 ≤ α ≤ 0.86) and item-total correlations (0.21 ≤ r$_{it}$ ≤ 0.71) were generally satisfactory to good. Furthermore, higher symptom severity was associated with a higher degree of functional impairment. The evaluation of convergent validity revealed positive results regarding clinical judgment and parent ratings (FBB-ADHS; FBB-SSV). Correlations between the ILF-EXTERNAL scales and the CBCL Externalizing Problems were moderate to high. Finally, the ILF-EXTERNAL scales were significantly more strongly associated with the CBCL Externalizing Problems than with the Internalizing Problems, indicating divergent validity. Conclusion In clinically referred, school-age children, the ILF-EXTERNAL demonstrates sound psychometric properties. The ILF-EXTERNAL is a promising clinical interview and contributes to high-quality diagnostics of externalizing disorders in children and adolescents

Helicobacter pylori Modulates the T Helper Cell 1/T Helper Cell 2 Balance through Phase-variable Interaction between Lipopolysaccharide and DC-SIGN

The human gastric pathogen Helicobacter pylori spontaneously switches lipopolysaccharide (LPS) Lewis (Le) antigens on and off (phase-variable expression), but the biological significance of this is unclear. Here, we report that Le+ H. pylori variants are able to bind to the C-type lectin DC-SIGN and present on gastric dendritic cells (DCs), and demonstrate that this interaction blocks T helper cell (Th)1 development. In contrast, Le− variants escape binding to DCs and induce a strong Th1 cell response. In addition, in gastric biopsies challenged ex vivo with Le+ variants that bind DC-SIGN, interleukin 6 production is decreased, indicative of increased immune suppression. Our data indicate a role for LPS phase variation and Le antigen expression by H. pylori in suppressing immune responses through DC-SIGN

Effect of smoking status on neuronal responses to graphic cigarette warning labels

Background Smoking is responsible for a large proportion of cancer, respiratory and cardiovascular deaths. Nevertheless the health risks of smoking are still underestimated in many smokers. The present study aimed to examine neurobiological responses to graphical warnings on cigarette packings in non-smokers and patients with tobacco dependence. Methods Twenty non-smokers and twenty-four patients with tobacco dependence participated in a functional MRI study during that pictures of different categories were presented ((a) EU-warning pictures, (b) text-only warnings, (c) neutral pictures with short information). Patients contributed twice in the experiment (after 10 hours nicotine withdrawal / about 5 minutes after nicotine consumption). Results Smokers during withdrawal demonstrated increased neuronal responses predominantly in subcortical, temporal and frontal brain regions that are associated with emotional and cognitive processes during the presentation of graphical warnings compared to neutral pictures. In smokers after smoking and non-smokers, the differences between graphical warnings and neutral pictures were increased compared to smokers during withdrawal. The comparison of the graphical warnings with text-only labels demonstrated the importance of affective brain regions especially in smokers after smoking and in non-smokers. During withdrawal, the neural responses associated with graphical warnings and text-only labels differed only marginally. Discussion and conclusion The results suggest that emotional and cognitive reactions to graphical warnings are predominantly seen in smokers after smoking and in non-smokers. The impact of these pictures during withdrawal seems to be less pronounced;in this case, more unspecific processes seem to be important, including the projection of sensory signals to the cerebral cortex