Perturbation Based Decomposition of sEMG Signals

Surface electromyography records the motor unit action potential signals in the vicinity of the electrode to reveal information on muscle activation. Decomposition of sEMG signals for characterization of constituent motor unit action potentials in terms of amplitude and firing times is useful for clinical research as well as diagnosis of neurological disorders. Successful decomposition of sEMG signals would allow for pertinent motor unit action potential information to be acquired without discomfort to the subject or the need for a well-trained operator (compared with intramuscular EMG). To determine amplitudes and firing times for motor unit action potentials in an sEMG recording, Szlavik\u27s perturbation based decomposition may be applied. The decomposition was initially applied to synthetic sEMG signals and then to experimental data collected from the biceps brachii. Szlavik\u27s decomposition estimator yields satisfactory results for synthetic and experimental sEMG signals with reasonable complexity

The Impact of Market-related Factors on the Choice of Foreign Market Entry Mode by Service Firms

The topic of internationalization has received an increased amount of attention due to globalization and growing amounts of international trade. One of the most important factors for the success of foreign market operations is the choice of the entry mode. This paper investigates the key determinants for the choice of foreign market entry mode. Specifically, the research examines the effects of market-related factors of the selected entry mode on service companies. This study contributes to the existing knowledge of internationalization of service companies by analyzing market-related factors of entry modes. Moreover, it provides managerial implications that might be applied by companies and governmental agencies to promote investment and internationalization of local companies

Dvostruki standardi u procjenama neetičnog ponašanja potrošača i poslovnih subjekata

Double standards in terms of individuals being more tolerant of questionable consumer practices than of similar business practices have been researched in several studies (e.g., De Bock, Vermeir & Van Kenhove, 2013; De Bock & Van Kenhove, 2011; Vermeir & Van Kenhove, 2008; DePaulo, 1987). However, a mismatch between the perceptions of a company’s corporate behavior and a consumer’s ethical behavior has scarcely been assessed from the point of view of individual differences on the consumer side. The purpose of the current study is to explore individual differences (optimistic versus pessimistic attitude towards business) in the use of ethical judgments regarding questionable conduct of a business versus that of a consumer. In other words, we investigate if the consumers who are positively disposed towards business are less critical of unethical corporate than of consumer actions. In our study, we compared the level of optimism with regard to businesses with attitudes towards business ethics (using the Perceived Role of Ethics and Social Responsibility scale (PRESOR) created by Singhapakdi, Vitell, Rallapalli and Kraft (1996)), and the attitudes towards consumer ethics (using the Consumer Ethics Scale (CES) by Vitell and Muncy (1992)). Research results indicate that the individuals having optimistic attitudes towards business are less likely to use double standards when it comes to (un)ethical consumer behavior, compared to (un)ethical corporate actions. Limitations and suggestions for further research are presented.Dvostruki standardi prema kojima pojedinci pokazuju veću razinu tolerancije prema etički upitnim postupcima potrošača nego prema sličnim postupcima u poslovnim svijetu istraživani su u nekoliko radova (npr. De Bock, Vermeir i Van Kenhove, 2013.; De Bock i Van Kenhove, 2011.; Vermeir i Van Kenhove,, 2008.; DePaulo, 1987.). No nepodudarnost percepcija o korporativnom etičkom ponašanju poduzeća i potrošača rijetko se procjenjivala iz perspektive individualnih razlika među potrošačima. Svrha ovog rada jest istražiti individualne razlike (optimistični u odnosu na pesimistične stavove o poslovanju) u etičkom prosuđivanju etički upitnog ponašanja poslovnih subjekata nasuprot takvom ponašanju potrošača. Drugim riječima, istražujemo jesu li potrošači pozitivnijeg stava prema poslovanju manje kritični prema neetičkim postupcima poduzeća u odnosu na takve, neetične postupke potrošača. U radu uspoređujemo razinu optimizma prema poslovanju sa stavovima prema poslovnoj etici (korištenjem ljestvice Percipirana uloga etike i društvene odgovornosti - PRESPOR čiji su autori Singhapakdi, Vitell, Rallapalli i Kraft,1996.), i stavove prema etici potrošača (korištenjem ljestvice Etike potrošača - CES autora Vittellija i Muncyja ,1992.). Rezultati istraživanja pokazuju da su pojedinci optimističnih stavova prema poslovanju manje skloni korištenju dvostrukih standarda po pitanju (ne)etičnog ponašanja potrošača u usporedbi s (ne)etičnim postupcima poduzeća. Navode se ograničenja istraživanja i preporuke za buduća istraživanja

Assorted effects of TGFβ and chondroitinsulfate on p38 and ERK1/2 activation levels in human articular chondrocytes stimulated with LPS

SummaryObjectivesInadequate cellular response of chondrocytes to stress frequently terminates in osteoarthritis (OA). Adequate response is fundamentally modulated by concerted cytokine signaling events, directing degradation and synthesis of cartilage on articular surfaces where and whenever necessary. Transforming growth factor (TGF)β is a prominent mediator in cartilage anabolism, although particular catabolic activities are occasionally reported. Clearly, before the TGFβ signal gets through to the gene regulatory machinery, cross talk with modulators occurs.MethodWe tested the hypothesis whether chondroitinsulfate (CS) modulates cell signaling. TGFβ and/or soluble CS was added to human articular chondrocytes (HACs) and activation of p38 and extracellular signal related kinase (ERK)1/2 was determined by immunoblot analysis. Expression levels of mRNA of matrix metalloproteinase (MMP)-2, -3 and -13 were determined by real-time polymerase chain reaction (PCR).ResultsNo significant effects were observed unless cells were stimulated with lipopolysaccharide (LPS), invigorating catabolic metabolism in chondrocytes. LPS effects, however, were profoundly modulated by TGFβ, CS and both applied in combination. Most prominent, the silencing of p38 stress signal by CS was superimposable to that of TGFβ. Phospho-ERK1/2 levels were raised by TGFβ three-fold over LPS induced levels. In contrast, CS treatment, alone or combined with TGFβ, reduced phosphorylation significantly below LPS induced levels. Finally, suppression of LPS induced MMP-13 mRNA levels resulted with CS.ConclusionSoluble CS modulates signaling events in chondrocytes concurrent with MMP-13 down regulation. The effects observed suggest a feedback signaling mechanism cross talking with TGFβ-signal pathways and may serve an explanation, on the cellular level, for the beneficial effects found in clinical studies with pharmacologic application of CS

Mathematical Modeling of Streptococcus pneumoniae Colonization, Invasive Infection and Treatment

Streptococcus pneumoniae (Sp) is a commensal bacterium that normally resides on the upper airway epithelium without causing infection. However, factors such as co-infection with influenza virus can impair the complex Sp-host interactions and the subsequent development of many life-threatening infectious and inflammatory diseases, including pneumonia, meningitis or even sepsis. With the increased threat of Sp infection due to the emergence of new antibiotic resistant Sp strains, there is an urgent need for better treatment strategies that effectively prevent progression of disease triggered by Sp infection, minimizing the use of antibiotics. The complexity of the host-pathogen interactions has left the full understanding of underlying mechanisms of Sp-triggered pathogenesis as a challenge, despite its critical importance in the identification of effective treatments. To achieve a systems-level and quantitative understanding of the complex and dynamically-changing host-Sp interactions, here we developed a mechanistic mathematical model describing dynamic interplays between Sp, immune cells, and epithelial tissues, where the host-pathogen interactions initiate. The model serves as a mathematical framework that coherently explains various in vitro and in vitro studies, to which the model parameters were fitted. Our model simulations reproduced the robust homeostatic Sp-host interaction, as well as three qualitatively different pathogenic behaviors: immunological scarring, invasive infection and their combination. Parameter sensitivity and bifurcation analyses of the model identified the processes that are responsible for qualitative transitions from healthy to such pathological behaviors. Our model also predicted that the onset of invasive infection occurs within less than 2 days from transient Sp challenges. This prediction provides arguments in favor of the use of vaccinations, since adaptive immune responses cannot be developed de novo in such a short time. We further designed optimal treatment strategies, with minimal strengths and minimal durations of antibiotics, for each of the three pathogenic behaviors distinguished by our model. The proposed mathematical framework will help to design better disease management strategies and new diagnostic markers that can be used to inform the most appropriate patient-specific treatment options

Potential organ or tumor imaging agents. 32. A triglyceride ester of P-Iodophenyl pentadecanoic acid as a potential hepatic imaging agent

A triglyceride analog, glycerol-2-palmitoyl-1,3-di-15-(p-iodophenyl)pentadecanoate (DPPG) was synthesized and radiolabeled for evaluation as a potential functional liver scintigraphic agent. Uptake of DPPG was compared in normal, diabetic, tumor-bearing and heparin pretreated rats, revealing differences in uptake and clearance of radioactivity, correlating with hepatic lipase activity of these groups. Similar results were observed by [gamma] -camera scintigraphy. Comparing the uptake of DPPG with that of its fatty acid component, 15-(p-iodophenyl)pentadecanoic acid (IPPA), revealed that the peak uptake of IPPA in the liver was about half that of DPPG. Based upon these findings, DPPG warrants further study as a hepatic radiodiagnostic agent.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29932/1/0000289.pd