Rerum cognoscere causas: part I - How do the ideas of system dynamics relate to traditional social theories and the voluntarism/determinism debate?

This is the first half of a two-part paper which deals with the social theoretic assumptions underlying system dynamics. The motivation is that clarification in this area can help mainstream social scientists to understand how our field relates to their literature, methods and concerns. Part I has two main sections. The aim of the first is to answer the question: How do the ideas of system dynamics relate to traditional social theories? The theoretic assumptions of the field are seldom explicit but rather are implicit in its practice. The range of system dynamics practice is therefore considered and related to a framework - widely used in both operational research (OR) and systems science - that organises the assumptions behind traditional social theoretic paradigms. Distinct and surprisingly varied groupings of practice are identified, making it difficult to place system dynamics in any one paradigm with any certainty. The difficulties of establishing a social theoretic home for system dynamics are exemplified in the second main section. This is done by considering the question: Is system dynamics deterministic? An analysis shows that attempts to relate system dynamics to strict notions of voluntarism or determinism quickly indicate that the field does not fit with either pole of this dichotomous, and strictly paradigmatic, view. Part I therefore concludes that definitively placing system dynamics with respect to traditional social theories is highly problematic. The scene is therefore set for Part II of the paper, which proposes an innovative and potentially fruitful resolution to this problem.

A multicommuted flow-system for spectrophotometric determination of tannin exploiting the Cu(I)/BCA complex formation

A flow system exploiting the multicommutation approach is proposed for spectrophotometric determination of tannin in beverages. The procedure is based on the reduction of Cu(II) in the presence of 4,4`-dicarboxy-2,2`-biquinoline, yielding a complex with maximum absorption at 558 nm. Calibration graph was linear (r=0.999) for tannic acid concentrations up to 5.00 mu mol L-1. The detection limit and coefficient of variation were estimated as 10 nmol L-1 (99.7% confidence level) and 1% (1.78 mu mol L-1 tannic acid, n=10), respectively. The sampling rate was 50 determinations per hour. The proposed procedure is more sensitive and selective than the official Folin-Denis method, also minimizing drastically waste generation. Recoveries within 91.8 and 115% were estimated for total tannin determination in tea and wine samples. (C) 2007 Elsevier B.V. All rights reserved.

A convenient synthetic route for alkynylselenides from alkynyl bromides and diaryl diselenides employing copper(I)/imidazole as novel catalyst system

A mild, convenient, and effective strategy is developed for the synthesis of alkynyl selenides from alkynyl bromides and respective diselenides using Cul/imidazole as a novel catalyst system with Mg as additive. The Procedure affords the title compounds in moderate to good yield (51-89%). The main advantages of the protocol include the use of inexpensive copper catalyst, a novel Cu(I)/imidazole combination, and good yield of the products. (C) 2008 Elsevier Ltd. All rights reserved.

Jämförelse av två system för att bedöma vinter väglag : Ett nytt system i utvecklingen för att säkra Sveriges vägar

Trafikverket, är den statliga verksamhet som har hand om alla Sveriges vägar och järnvägar har den så kallade nollvisionen som ett huvudmål. Tanken bakom nollvisionen är att de som använder vägarna skall vara säkra och inte komma till skada. En del av uppfyllandet av detta mål är att Trafikverket ger ut korttidsprognoser för väglag och körförhållande. I nuläget så används ett mycket manuellt systemet som heter NTIS, men man håller på att utveckla det nya automatiska systemet RCC som skall kunna ta fram korttidsprognoser baserat på olika former av data, t.ex. data från väderstationer. Syftet med denna studie är att utvärdera hur väl de två olika systemen utför en korttidsprognos och jämföra de mot varandra, samt verkligheten. Denna studie gjordes i form av en förklarande fallstudie. Som datainsamling används dokument i olika former och analysen var kvantitativ då resultatet av utvärdering ger olika procenttal av hur rätt respektive system har. Under undersökningen gång så kom vi fram till att båda systemen hade sina fördelar och nackdelar. T.ex. så det gamla NTIS systemet fortfarande bäst på isigt och moddigt väglag. Medans det nya RCC systemet hade sina egna fördelar, t.ex. snöigt väglag och vått väglag. Samt så hade RCC en klar fördel med sin rapporteringstid, vilket var ett problem man såg med NTIS. Resultat var som sagt ett procenttal av hur rätt de två olika systemen hade, men även förslag till förbättringar. T.ex. hur man skulle kunna ändra RCC regler för bättre resultat.

Down-modulation of lymphoproliferation and interferon-gamma production by beta-glucan derived from Saccharomyces cerevisiae

beta-glucan, one of the major cell wall components of Saccharomyces cerevisiae, has been found to enhance immune functions. This study investigated in vivo and in vitro effects of beta-glucan on lymphoproliferation and interferon-gamma (IFN-gamma) production by splenic cells from C57BL/6 female mice. All experiments were performed with particulate beta-glucan derived from S. cerevisiae. Data demonstrated that both, i.p administration of particulate beta-glucan (20 or 100 µg/animal) and in vitro stimulation of splenic cells (20 or 100 µg/ml of culture) decreased lymphoproliferation and IFN-gamma production induced by concanavalin A. These results suggest that beta-glucan can trigger a down-modulatory effect regulating a deleterious immune system hyperactivity in the presence of a strong stimulus.

Effects of Spider Venom Toxin PWTX-I (6-Hydroxytrypargine) on the Central Nervous System of Rats

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Intra-regional payments system: draft resolution approved by Committee I on 23 May 1957

Includes bibliography

Caribbean Information System-Economic and Social Planning (CARISPLAN): final report: phase I, period 1 May 1979-31 December 1980

Includes bibliography

Lack of reproductive toxicity in adult male rats exposed to interferon-alpha

Interferon-alpha (IFN- α ), a type I IFN, is a protein with antiviral, antiproliferative, and immunoregulatory activities, widely used in the treatment of several types of cancers as well as hepatitis B and C. Decrease of libido and erectile dysfunction are commonly reported by male patients during treatment of chronic hepatitis C with IFN- α . However, IFN therapy-associated underlying factors attributed to sexual dysfunction are still not well defined. Currently, there are few studies investigating the effects of IFN on male reproductive system functions. Given that, the aim of the present investigation was to examine effects of subchronic exposure to IFN- α (5 × 10(4) U/kg and 10 × 10(4) U/kg, 30 d) on serum hormones, sperm parameters, fertility, and testicular and epididymal hystopathology and morphometry in adult male Wistar rats. None of the evaluated parameters was markedly altered by IFN- α . Thus, our results suggest that exposure to IFN- α , in this experimental design, did not adversely affect sperm quality and fertile capacity of male rats.

Evaluation of an In Vitro Blood-Based Assay to Detect Production of Interferon-γ By <i>Mycobacterium Bovisi>–Infected White-Tailed Deer (<i>Odocoileus Virginianusi>)

Tuberculosis due to Mycobacterium bovis in captive Cervidae was identified as an important disease in the United States in 1990 and prompted the addition of captive Cervidae to the USDA Uniform Methods and Rules for eradication of bovine tuberculosis. As well, M. bovis infection was identified in free-ranging white-tailed deer in northeast Michigan in 1995. Tuberculosis in both captive and free-ranging Cervidae represents a serious challenge to the eradication of M. bovis infection from the United States. Currently, the only approved antemortem tests for tuberculosis in Cervidae are the intradermal tuberculin skin test and the blood tuberculosis test (BTB). At present, the BTB is not available in North America. Tuberculin skin testing of Cervidae is time-consuming and involves repeated animal handling and risk of injury to animals and humans. This study evaluated the potential of a new blood-based assay for tuberculosis in Cervidae that would decrease animal handling, stress, and losses due to injury. In addition, a blood-based assay could provide a more rapid diagnosis. Twenty 6–9-month-old white-tailed deer, male and female, were experimentally inoculated by instillation of 300 colony-forming units of M. bovis in the tonsillar crypts. Seven, age-matched uninfected deer served as controls. Blood was collected on days 90, 126, 158, 180, 210, 238, 263, and 307 after inoculation and was analyzed for the production of interferon-γ (IFN-γ) in response to incubation with M. bovis purified protein derivative (PPDb), M. avium PPDa, pokeweed mitogen (PWM), or media alone. Production of IFN-g in response to PPDb was significantly greater (P < 0.05) at all time points in samples from M. bovis–infected deer as compared with uninfected control deer, whereas IFN-γ production to PWM did not differ significantly between infected and control deer. Measurement of IFN-γ production to PPDb may serve as a useful assay for the antemortem diagnosis of tuberculosis in Cervidae.

Review of <i> Native Americans in the School System: Family, Community, and Academic Achievementi> by Carol J. Ward

The title of this volume promises more than the content delivers. The heart of the book is information from Ward's 1992 University of Chicago doctoral dissertation, which focused on the social and cultural reasons leading to students dropping out of school. Her first two chapters provide a good review of research on dropouts and Indian education; the following six focus on the results of her 1987-1989 study of 698 Northern Cheyenne, Crow, and white high school students attending the Colstrip Public, St. Labre Catholic, and Busby Tribal Schools in Montana. Fifty-two percent of the students in this study were Indian, with a dropout rate of 45% .