Resetting intrinsic purinergic modulation of neural activity: an associative mechanism?

The purines, ATP and adenosine, control the rundown and termination of swimming in the Xenopus embryo. This intrinsic purinergic modulation, unavoidably present during every swimming episode, could lead to stereotyped inflexible behavior and consequently could jeopardize the survival of the embryo. To explore whether this control system can exhibit adaptability, I have used a minimal simulation in which a model neuron released ATP that (1) inhibited K+ currents and (2) was converted by ectonucleotidases to adenosine, which then inhibited Ca2+ currents. The model neuron exhibited an accommodating spike train controlled by the actions of ATP and adenosine. Feedforward inhibition by the upstream metabolite ADP of the ecto-5'-nucleotidase that converts AMP to adenosine introduced adaptability and allowed the resetting of spike accommodation. The strength of feedforward inhibition determined the extent to which resetting could occur. I have tested these predictions by examining swimming in the real embryo. The rundown of swimming was reset in a manner similar to that predicted by the single-neuron model. By blocking the purinoceptors, I have demonstrated that resetting in the embryo is attributable to the actions of the purines and results from feedforward inhibition of adenosine production. The resetting of rundown in the motor systems can be reformulated as an associative mechanism in which the temporal coincidence of two stimuli can prolong network activity if they fall within a particular time window. The length of the time window and the magnitude of the prolongation of neural activity both depend on the strength of the feedforward ADP-mediated inhibition of the ecto-5'-nucleotidase

Readjusting the social democratic welfare state in Denmark 1973 - 2003

As a social democratic welfare state, Denmark has offered universal and generous benefits promoting equality and diminishing stigmatisation; provision is almost entirely taxfinanced and public services play an important role. Consequently, welfare state spending has been traditionally high. Thus, one would expect that globalisation and low economic growth will threaten this welfare state arrangement. However, the example of Denmark shows that high public expenditure on the welfare state could be conserved. Albeit, in the last decade this small country in the North of Europe has gained much attention as role model for successful welfare state restructuring. The question is thus, how did Denmark readjust its welfare state to the changed environment? Therefore the present paper focuses on policy developments in four major welfare programmes: health care, labour market, old-age pensions and family since the 1970s. By comparatively contrasting these developments the paper is furthermore able to identify patterns in the process of readjusting the Danish welfare state. --

Revenue Management and Demand Fulfillment: Matching Applications, Models, and Software

Recent years have seen great successes of revenue management, notably in the airline, hotel, and car rental business. Currently, an increasing number of industries, including manufacturers and retailers, are exploring ways to adopt similar concepts. Software companies are taking an active role in promoting the broadening range of applications. Also technological advances, including smart shelves and radio frequency identification (RFID), are removing many of the barriers to extended revenue management. The rapid developments in Supply Chain Planning and Revenue Management software solutions, scientific models, and industry applications have created a complex picture, which appears not yet to be well understood. It is not evident which scientific models fit which industry applications and which aspects are still missing. The relation between available software solutions and applications as well as scientific models appears equally unclear. The goal of this paper is to help overcome this confusion. To this end, we structure and review three dimensions, namely applications, models, and software. Subsequently, we relate these dimensions to each other and highlight commonalities and discrepancies. This comparison also provides a basis for identifying future research needs.Manufacturing;Revenue Management;Software;Advanced Planning Systems;Demand Fulfillment

THE RELATIONSHIP BETWEEN MUSCULOSKELETAL STRENGTH, PHYSIOLOGICAL CHARACTERISTICS, AND KNEE KINESTHESIA FOLLOWING FATIGUING EXERCISE

Fatiguing exercise may result in impaired functional joint stability and increased risk of unintentional injury. While there are several musculoskeletal and physiological characteristics related to fatigue onset, their relationship with proprioceptive changes following fatigue has not been examined. The purpose of this study was to establish the relationship between musculoskeletal and physiological characteristics and changes in proprioception, measured by threshold to detect passive motion (TTDPM), following fatiguing exercise. Twenty, physically active females participated (age: 28.65 ± 5.6 years, height: 165.6 ± 4.3 cm, weight: 61.8 ± 8.0 kg, BMI: 22.5± 2.3 kg/m2, BF: 23.3 ± 5.4%). During Visit 1, subjects completed an exercise history and 24-hour dietary questionnaire, and body composition, TTDPM familiarization, isokinetic knee strength, and maximal oxygen uptake/lactate threshold assessments. During Visit 2, subjects completed TTDPM and isometric knee strength testing prior to and following a fatiguing exercise protocol. Wilcoxon signed rank tests determined TTDPM and isometric knee strength changes from pre- to post- fatigue. Spearman’s rho correlation coefficients determined the relationship between strength and physiological variables with pre- to post-fatigue changes in TTDPM and with pre-fatigue and post-fatigue TTDPM in extension and flexion (α=0.05). No significant differences were demonstrated from pre-fatigue to post-fatigue TTDPM despite a significant decrease in isometric knee flexion strength (P<0.01) and flexion/extension ratio (P<0.05) following fatigue. No significant correlations were observed between strength or physiological variables and changes in TTDPM from pre- to post-fatigue in extension or flexion. Flexion/extension ratio was significantly correlated with pre-fatigue TTDPM in extension (r=-0.231, P<0.05). Peak oxygen uptake was significantly correlated with pre-fatigue (r=-0.500, P<0.01) and post-fatigue (r=-0.520, P<0.05) TTDPM in extension. No significant relationships were demonstrated between musculoskeletal and physiological characteristics and changes in TTDPM following fatigue. The results suggest that highly trained individuals may have better proprioception, and that the high fitness level of subjects in this investigation may have contributed to absence of TTDPM deficits following fatigue despite reaching a high level of perceptual and physiological fatigue. Future studies should consider various subject populations, other musculoskeletal strength characteristics, and different modalities of proprioception to determine the most important contributions to proprioceptive changes following fatigue

Cooperative R&D: Federal Efforts to Promote Industrial Competitiveness

[Excerpt] In response to the foreign challenge in the global marketplace, the United States Congress has explored ways to stimulate technological advancement in the private sector. The government has supported various efforts to promote cooperative research and development activities among industry, universities, and the federal R&D establishment designed to increase the competitiveness of American industry and to encourage the generation of new products, processes, and services. Collaborative ventures are intended to accommodate the strengths and responsibilities of all sectors involved in innovation and technology development. Academia, industry, and government often have complementary functions. Joint projects allow for the sharing of costs, risks, facilities, and expertise. Cooperative activity covers various institutional and legal arrangements including industry-industry, industry-university, and industry-government efforts. Proponents of joint ventures argue that they permit work to be done that is too expensive for one company to support and allow for R&D that crosses traditional boundaries of expertise and experience. Such arrangements make use of existing, and support the development of new, resources, facilities, knowledge, and skills. Opponents argue that these endeavors dampen competition necessary for innovation. Federal efforts to encourage cooperative activities include the National Cooperative Research Act; the National Cooperative Production Act; tax changes permitting credits for industry payments to universities for R&D and deductions for contributions of equipment used in academic research; and amendments to the patent laws vesting title to inventions made under federal funding in universities. Technology transfer from the government to the private sector is facilitated by several laws. In addition, there are various ongoing cooperative programs supported by multiple federal departments and agencies. Given the increased popularity of cooperative programs, questions might be raised as to whether they are meeting expectations. Among the issues before Congress are whether joint ventures contribute to industrial competitiveness and what role, if any, the government has in facilitating such arrangements

Flashing LEDs for microalgal production

Flashing lights are next-generation tools to mitigate light attenuation and increase the photosynthetic efficiency of microalgal cultivation systems illuminated by light-emitting diodes (LEDs). Optimal flashing light conditions depend on the reaction kinetics and properties of the linear electron transfer chain, energy dissipation, and storage mechanisms of a phototroph. In particular, extremely short and intense light flashes potentially mitigate light attenuation in photobioreactors without impairing photosynthesis. Intelligently controlling flashing light units and selecting electronic components can maximize light emission and energy efficiency. We discuss the biological, physical, and technical properties of flashing lights for algal production. We combine recent findings about photosynthetic pathways, self-shading in photobioreactors, and developments in solid-state technology towards the biotechnological application of LEDs to microalgal production.Foundation for Science and Technology (FCT, Portugal) [CCMAR/Multi/04326/2013]Nord UniversityNordland County Government (project Bioteknologi en framtidsrettet naering)INTERREG V-A Espana-Portugal project [0055 ALGARED + 5E]Portuguese Foundation for Science and Technology [SFRH/BD/105541/2014, SFRH/BD/115325/2016]info:eu-repo/semantics/publishedVersio

Bacillus anthracis edema factor substrate specificity: evidence for new modes of action

Since the isolation of Bacillus anthracis exotoxins in the 1960s, the detrimental activity of edema factor (EF) was considered as adenylyl cyclase activity only. Yet the catalytic site of EF was recently shown to accomplish cyclization of cytidine 5'-triphosphate, uridine 5'-triphosphate and inosine 5'-triphosphate, in addition to adenosine 5'-triphosphate. This review discusses the broad EF substrate specificity and possible implications of intracellular accumulation of cyclic cytidine 3':5'-monophosphate, cyclic uridine 3':5'-monophosphate and cyclic inosine 3':5'-monophosphate on cellular functions vital for host defense. In particular, cAMP-independent mechanisms of action of EF on host cell signaling via protein kinase A, protein kinase G, phosphodiesterases and CNG channels are discussed