Fuchs (2010Fuchs, C.2010. Labor in information capitalism and on the Internet. The Information Society 26:179–196.[Taylor & Francis Online], [Web of Science ®], [Google Scholar], 2012Fuchs, C.2012. With or without Marx? With or without capitalism?: A re-joinder to Adam Arvidsson and Eleanor Colleoni.tripleC 10 (2):633–45.[Google Scholar]) argues that users of social media produce value and surplus value in the Marxian sense. Arvidsson and Colleoni (2012Arvidsson, A., and E. Colleoni. 2012. Value in information capitalism and on the Internet. The Information Society 28:135–50.[Taylor & Francis Online], [Web of Science ®], [Google Scholar]) critique this hypothesis, claiming that Marx's theory of value is irrelevant to the regime of value production on social media platforms in particular and in informational capitalism in general. They claim that the affective relations and financial speculations that generate value on social media are not dependent on labor time. This article critically engages Fuchs, and Arvidsson and Colleoni, by revisiting Marx's theory of value. Contra Fuchs, we argue that audiences do not produce value and surplus value—neither for social nor for mass media. Contra Arvidsson and Colleoni, we argue that so-called affective relations (philia) do not produce value either. Instead we demonstrate that social media generate revenue from four primary sources—by leasing advertisement space to generate advertisement rent, by selling information, by selling services to advertisers, and by generating profits from fictitious capital and speculative windfalls. All four, we argue, can be adequately explained by Marx's theory of value. 相似文献
For the following mixed bivariate probability distribution between a discrete random variable X and a continuous random variable Λ: where α, β > 0, 0 < p = 1 ? q < 1, x=0,1,2,...,a canonical expansion is obtained in terms of the Laguerre and Meixner orthogonal polynomials. The chance mechanisms giving rise to this mixed bivariate distribution are also discussed. 相似文献
In this paper I argue—against van Fraassen's constructiveempiricism—that the practice of saving phenomena is muchbroader than usually thought, and includes unobservable phenomenaas well as observable ones. My argument turns on the distinctionbetween data and phenomena: I discuss how unobservable phenomenamanifest themselves in data models and how theoretical modelsable to save them are chosen. I present a paradigmatic casestudy taken from the history of particle physics to illustratemy argument. The first aim of this paper is to draw attentionto the experimental practice of saving unobservable phenomena,which philosophers have overlooked for too long. The secondaim is to explore some far-reaching implications this practicemay have for the debate on scientific realism and constructiveempiricism.
1Introduction
2Unobservable Phenomena
2.1Dataand phenomena
2.2What isa data model?
2.3Data modelsand unobservable phenomena
3Saving Unobservable Phenomena:An Exemplar
4The October Revolution of 1974: From the J/to Charmonium
4.1A new unobservable phenomenon at 3.1 Ge V
4.2How thecharmonium model saved the new unobservable phenomenon
4.2.1The J/ as a baryon–antibaryon bound state
4.2.2TheJ/ as the spin-1 meson of a model with three charmedquarks
Intensive exercising may significantly damage muscles which is reflected in pain, fatigue and the increase of muscle proteins concentrations in blood such are creatinin kinase (CK), lactic dehydrogenase (LD), myoglobin (MB) and other biochemical parameters including urea serum concentration (SU). Biochemical markers vary with age, sex, race, muscle mass, physical activity and climate conditions. They also assist us in determining the limit between the capacity for adaptation to given training process which results in supercomepensation and in condition of overtraining (OT), in the case of load that exceeds the physiologic potential of regeneration. Concerning the problem of diagnosis and explanation of the symptoms of overtraining, markers that can apply reliably and with sufficient sensitivity and simplicity of interpretation in the praxis are sought. It is critical to take into account difference among individuals and groups that could hamper the interpretation.
The most frequently used markers:
The most frequently used biomarkers that provide us with the information on physical activity and on the amount of load through exercise are CK, SU and LD. Level of serum retaining kinas has been measured and interpreted for years as part of different scientific and professional investigations and presents one of basic parameters for determining the level of muscle damage. It reaches maximal concentration of the fourth day of exercising which depends on the type of exercise and the nature of stress triggered by exercise but also on individual characteristics.The level of serum urea presents marker of nitric compounds metabolism and is the principle chemical substance in the urine of mammals. It is thus possible to draw a parallel between the increases of serum urea concentration on increased degradations of proteins. Significant fall of serum amino acid levels occurs after sixty to seventy minutes of exercising with the increase of urea and free tyrosine and these changes have high correlation with the duration and intensity of.LD changes are important index of well-trained sportsmen and their capability to withstand the pace and force during strain in the training process. The level of LD is a good index of exercise intensity and marker of metabolic exchange in tissues whose concentration in serum is dependent of cell damage.
Conclusion:
There is not a single, unique parameter that would provide enough valuable information for the estimation of the quality of exercising, amount of load and identification of overtraining. Delayed measurement of biomarkers is far from ideal, but it is obvious that the amount of stress/ load in training is the most important factor for the development of state of overtraining. Daily body weight control, diet, biochemical indices values and the input of water should be known and standardized before measurements. For the most of parameters determination of basal levels are needed in specific populations for more accurate interpretation and evaluation of results. The sampling process itself should be under the most strict conditions of standardization by repeating measurement at least every third day. Dependence of mentioned parameters (SU, CK, LD) on exercise intensity varies among individuals and without these additional measurements and subpopulation evaluations it is difficult to come to conclusions with certainty as well as to come to conclusions on causative correlations of training load and dynamic in biochemical parameters.
Science has greatly contributed to the advancement of technology and to the innovation of production processes and their applications. Cleaning products have become indispensable in today’s world, as personal and environmental hygiene is important to all societies worldwide. Such products are used in the home, in most work environments and in the industrial sectors. Most of the detergents on the market are synthesised from petrochemical products. However, the interest in reducing the use of products harmful to human health and the environment has led to the search for detergents formulated with natural, biodegradable surfactant components of biological (plant or microbiological) origin or chemically synthesised from natural raw materials usually referred to as green surfactants. This review addresses the different types, properties, and uses of surfactants, with a focus on green surfactants, and describes the current scenario as well as the projections for the future market economy related to the production of the different types of green surfactants marketed in the world.How to cite: Farias CBB, Almeida FCG, Silva IA, et al. Production of green surfactants: Market prospects. Electron J Biotechnol 2021;51. https://doi.org/10.1016/j.ejbt.2021.02.002 相似文献
Since more than twenty years ago, some species of bacteria and fungi have been used to produce protein biomass or single-cell protein (SCP), with inexpensive feedstock and wastes being used as their sources of carbon and energy. The role of SCP as a safe food and feed is being highlighted more because of the worldwide protein scarcity. Even though SCP has been successfully commercialized in the UK for decades, study of optimal fermentation conditions, various potential substrates, and a broad range of microorganisms is still being pursued by many researchers. In this article, commonly used methods for the production of SCP and different fermentation systems are briefly reviewed, with submerged fermentation being highlighted as a more commonly used method. Emphasis is given to the effect of influencing factors on the biomass yield and productivity in an effort to provide a comprehensive review for researchers in related fields of interest.How to cite: Reihani SFS, Khosravi-Darani K. Influencing factors on single cell protein production by submerged fermentation: A review. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.11.005. 相似文献
The study was conducted in filarial endemic area for various clinical presentations and diagnosis of occult filariasis. A total of 157 cases of various clinical presentations namely tropical pulmonary eosinophilia, monoarthritis, polyarthritis, glomerulonephropathy, tenosynovitis, inguinal lymphadenopathy, generalised lymphadenopathy, retroperitonial lymphadenopathy, endomyocardial fibrosis and acute conjunctivitis were screened for filarial antigen and antibody by enzyme linked immunosorbent assay (ELISA). Out of 157 cases, 107 cases were positive for antigen or antibody, suggesting the role of filarial infection in these clinical presentations. All the 107 cases were treated with diethylcarbamazine citrate (DEC) and some of the patients who were followed showed relief in signs and symptoms. Hence assay of filarial antigen and/or antibody may be useful for diagnosing occult filarial syndromes for better management and further appropriate treatment. 相似文献
BackgroundMathematical modeling is useful in the analysis, prediction, and optimization of an enzymatic process. Unlike the conventional modeling methods, Monte Carlo method has special advantages in providing representations of the molecule’s spatial distribution. However, thus far, Monte Carlo modeling of enzymatic system is namely based on unimolecular basis, not suitable for practical applications. In this research, Monte Carlo modeling is performed for enzymatic hydrolysis of lactose for the purpose of real-time applications.ResultsThe enzyme hydrolysis of lactose, which is conformed to Michaelis–Menten kinetics, is modeled using the Monte Carlo modeling method, and the simulation results prove that the model predicts the reaction kinetics very well.ConclusionsMonte Carlo modeling method can be used to model enzymatic reactions in a simple way for real-time applications.How to cite: Gao L, Guo Q, Lin H, et al. Modeling of lactose enzymatic hydrolysis using Monte Carlo method. Electron J Biotechnol 2019;41.https://doi.org/10.1016/j.ejbt.2019.04.010 相似文献
BackgroundAmmonium stress is a prime limiting phenomenon that occurs during methane formation from poultry manure. It is caused by elevated ammonium nitrogen concentrations that result from substrate decomposition. The amounts of methane formed depend on the activity of methanogenic microbes.ResultsDuring the research reported in this paper, the response of a mesophilic consortium inhabiting a biogas reactor to rising load of poultry manure was investigated. The taxonomic composition of bacterial population was mostly typical, however syntrophic bacteria were not detected. This absence resulted in limitation of succession of some methanogenic microorganisms, especially obligate hydrogenotrophs. The methanogenic activity of the consortium was totally dependent on the activity of Methanosaeta. Inhibition of methanoganesis was noticed at ammonium nitrogen concentration of 3.68 g/L, total cessation occurred at 5.45 g/L. Significant amounts of acetic acid in the fermentation pulp accompanied the inhibition.ConclusionsThe effectiveness of the consortium was totally dependent on the metabolic activity of the acetoclastic Methanoseata genus and lack of SAOB did not allow hydrogenotrophic methanogens to propagate and lead to cessation of biogas production at an elevated ammonium concentration at which acetoclastic methanogens were inhibited.How to cite: Świątek M, Lewicki A, Szymanowska D, et al. The effect of introduction of chicken manure on the biodiversity and performance of an anaerobic digester. Electron J Biotechnol 2019;37. https://doi.org/10.1016/j.ejbt.2018.11.002. 相似文献
One of the most relevant problems affecting the efficient use of e-mail to communicate worldwide is the spam phenomenon. Spamming involves flooding Internet with undesired messages aimed to promote illegal or low value products and services. Beyond the existence of different well-known machine learning techniques, collaborative schemes and other complementary approaches, some popular anti-spam frameworks such as SpamAssassin or Wirebrush4SPAM enabled the possibility of using regular expressions to effectively improve filter performance. In this work, we provide a review of existing proposals to automatically generate fully functional regular expressions from any input dataset combining spam and ham messages. Due to configuration difficulties and the low performance achieved by analysed schemes, in this work we introduce DiscoverRegex, a novel automatic spam pattern-finding tool. Patterns generated DiscoverRegex outperform those created by existing approaches (able to avoid FP errors) whilst minimising the computational resources required for its proper operation. DiscoverRegex source code is publicly available at https://github.com/sing-group/DiscoverRegex. 相似文献
