Miracle-dz/UniFAR-FTUs huggingface dataset:
Learning in firms: Knowledge-based and property rights perspectives

Proponents of the knowledge-based approach to the firm argue that organizational economics put all the burden on the allocation of incentives and property rights in the explanation of organizational phenomena, and neglects firm- specific knowledge and processes of learning. We argue that there is no inherent reason why organizational economics should be cut off from treating learning and exploring its organizational implications. More specifically, we demonstrate that it is possible to adopt an approach to learning that is consistent with rational choice methodology and stresses economizing, puts the emphasis on learning as a means of realizing efficiencies, is micro-analytic, and contains implications for economic organization. We concentrate on the role of experimentation as a means of finding solutions to coordination problems in complex production systems ( e.g., finding the optimal sequence of activities) and the transaction costs learning-by-experi- menting may create. Such transaction costs help determine the existence, bound- aries and internal organization of the firm, and have implications for the understanding of competitive advantage.
A comparative study on distant free-hand pointing

In this paper we present a comparative study of free-hand pointing, an absolute remote pointing device. Unimanual and bimanual interaction were tested as well as the static reference system (spatial coordinates are fixed in the space in front of the TV) and novel body-aligned reference system (coordinates are bound to the current position of the user). We conducted a point-and-click experiment with 12 participants. We have identified the preferred interaction areas for left- and right-handed users in terms of hand preference and preferred spatial areas of the interaction. In bimanual interaction, the users relied more on dominant hand, switching hands only when necessary. Even though the remote pointing device was faster than the free-hand pointing, it was less accepted probably due to its low precision.
Long term hedging of the Australian All Ordinaries Index using a bivariate error correction FIGARCH model

This article compares the performance of bivariate error correction GARCH and FIGARCH models when estimating long term dynamic minimum variance hedge ratios (MVHRs) on the Australian All Ordinaries Index. The paper therefore introduces the bivariate error correction FIGARCH model into the hedging literature, which to date has only employed the GARCH class of processes. This is important for those interested in managing long term equity exposures, given that FIGARCH processes exhibit long memory, whilst the GARCH class of processes exhibit short memory. The naive hedge ratio, the constant MVHR estimated via ordinary least squares (the OLS MVHR), the single period dynamic MVHR and the multi-period dynamic MVHR of Lee (1999) are considered. The results strongly support the estimation of dynamic MVHRs that allow for time varying correlations. Whilst long memory dependencies appear important, a multi-period dynamic MVHR that responds more rapidly to persistent changes in volatility dynamics requires development.
Altered Attitudes of People toward Robots : Investigation through the Negative Attitudes toward Robots Scale ∗

It is important to measure what images, opinions, and attitudes people have developed toward robots and how they can be changed, from scientific and engineering perspectives. This paper reports results of social research on Japanese people’s attitudes toward robots by using “the Negative Attitudes toward Robots Scale (NARS). ” They revealed that attitudes toward robots differ depending on assumptions about robots such as their type and task, and there may be gender differences associated with them. Based on the results, the paper then discusses how people’s attitudes toward robots can be
On Swarm Stability of Linear Time-Invariant Descriptor Compartmental Networks

Swarm stability is studied for descriptor compartmental networks with linear time-invariant protocol. Compartmental network is a specific type of dynamical multi-agent system. Necessary and sufficient conditions for both consensus and marginal swarm stability are presented, which require a joint matching between the interactive dynamics of nearest neighbouring vertices and the Laplacian spectrum of the overall network topology. Three numerical instances are provided to verify the theoretical results.
The more, the better? Counterfactual evidence on the effect of compulsory voting on the consistency of party choice

Compulsory voting (CV) undoubtedly raises electoral turnout. Yet does it also affect individual party choices and aggregate election outcomes? Previous studies have focused on partisan or ‘directional’ effects of CV in favour of, for example, social-democratic or anti-establishment parties. These effects are usually small, however. Using survey data from the Belgian General Elections Study, this article finds that CV primarily affects the consistency, rather than the direction, of party choices. In particular, the analyses suggest that CV compels a substantial share of uninterested and less knowledgeable voters to the polls. These voters, in turn, cast votes that are clearly less consistent with their own political preferences than those of the more informed and motivated voluntary voters. Claims that CV promotes equal representation of political interests are therefore questionable.
Optimal Option Portfolio Strategies

Options should play an important role in asset allocation. They allow for kernel spanning and provide access to additional (priced) risk factors such as stochastic volatility and negative jumps. Unfortunately, traditional methods of asset allocation (e.g. mean-variance optimization) are not adequate for options because the distribution of returns is non-normal and the short sample of option returns available makes it difficult to estimate the distribution. We propose a method to optimize option portfolios that solves these limitations. An out-of-sample exercise is performed and we show that, even when transaction costs are incorporated, our portfolio strategy delivers an annualized Sharpe ratio of 0.59 between January 1996 and September 2008.We offer a simple portfolio optimization method that solves simultaneously these problems. Instead of a mean-variance objective, we maximize an expected utility function, such as power utility, which accounts for all the moments of the portfolio return distribution and, in particular, penalizes negative skewness and high kurtosis. We deal with the small sample of option returns by relying on data for the underlying asset instead. In our application, we use returns of the S&P 500 index since 1950 to simulate returns of the underlying asset going forward and, from the definition of option payoffs, generate simulated option returns. Plugging the simulated option returns into the utility function and averaging across simulations gives us an approximation of the expected utility which can be maximized to obtain optimal portfolio weights. Note that only current option prices are needed in our procedure, since the payoff is determined by the simulations of the underlying asset. We study the performance of our optimal option portfolio strategies, which we denote by OOPS, in an out-of-sample (OOS) exercise. We find the optimal option portfolios one month before option maturity and examine the return that they would have had at maturity. The resulting time series of returns could have been obtained by an investor following our method in real time. We can then compute measures of performance such as Sharpe ratios or alphas to assess the interest of the method. It should be stressed that for the each OOS observation, only one month of option observations is needed. For the entire period of 153 monthly observations, 99% of the sample is OOS. This per se is significantly different from previous studies. OOPS have large Sharpe ratios in our sample period between January 1996 and September 2008. The best strategy yields a Sharpe ratio of 0.59. This compares well with the Sharpe ratio of the market in the same period of 0.20, or even in the full sample since 1950 of 0.40. In addition, several strategies present positive skewness and low excess kurtosis. We find that our strategies load significantly on all four options, and that the optimal weights vary over time. Finally, our optimal strategies are almost delta-neutral albeit with significant elasticity.
The Shining Future of UV Spectral Synthesis

Abstract With the coming generation of instruments and telescopes capable of spectroscopy of high redshift galaxies, the spectral synthesis technique in the rest-frame UV and Far-UV range will become one of a few number of tools remaining to study their young stellar populations in detail. The rest-frame UV lines and continuum of high redshift galaxies, observed with visible and infrared telescopes on Earth, can be used for accurate line profile fitting such as Pvλλ1118, 1128, Ciiiλ1176, and Civλ1550. These lines are very precise diagnostic tools to estimate ages, metallicities, and masses of stellar populations. Here we discuss the potential for spectral synthesis of rest-frame UV spectra obtained at the Keck telescope. As an example, we study the 8 o'clock arc, a lensed galaxy at z=2.7322. We show that the poor spectral type coverage of the actual UV empirical spectral libraries limits the age and metallicity diagnostic. In order to improve our knowledge of high redshift galaxies using spectral synthesis, UV stellar libraries need to be extended to obtain accurate age, metallicity, and mass estimates likely to be occuring in young stellar populations observed in the early universe.
Differential Seroprevalence of Human Bocavirus Species 1-4 in Beijing, China

Background Four species of human bocaviruses (HBoV1-4) have been identified based on phylogenetic analysis since its first report in 2005. HBoV1 has been associated with respiratory disease, whereas HBoV2-4 are mainly detected in enteric infections. Although the prevalence of HBoVs in humans has been studied in some regions, it has not been well addressed globally. Methodology/Principal Findings Cross-reactivity of anti-VP2 antibodies was detected between HBoV1, 2, 3, and 4 in mouse and human serum. The prevalence of specific anti-VP2 IgG antibodies against HBoV1-4 was determined in different age groups of healthy individuals aged 0-70 years old in Beijing, China, using a competition ELISA assay based on virus-like particles of HBoV1-4. The seroprevalence of HBoV1-4 was 50%, 36.9%, 28.7%, and 0.8%, respectively, in children aged 0-14 years (n = 244); whereas the seroprevalence of HBoV1-4 was 66.9%, 49.3%, 38.7% and 1.4%, respectively, in healthy adults (≥15 years old; n = 142). The seropositive rate of HBoV1 was higher than that of HBoV2, HBoV3, and HBoV4 in individuals older than 0.5 years. Furthermore, IgG seroconversion of HBoV1 (10/31, 32.3%), HBoV2 (8/31, 25.8%), and HBoV3 (2/31, 6.5%) was found in paired sera collected from children with respiratory tract infections who were positive for HBoV1 according to PCR analysis. Conclusions/Significance Our data indicate that HBoV1 is more prevalent than HBoV2, HBoV3, and HBoV4 in the population we sampled in Beijing, China, suggesting that HBoV species may play differential roles in disease.
Dynamics and unfolding pathways of a hyperthermophilic and a mesophilic rubredoxin

Molecular dynamics simulations in solution are performed for a rubredoxin from the hyperthermophilic archaeon Pyrococcus furiosus (RdPf) and one from the mesophilic organism Desulfovibrio vulgaris (RdDv). The two proteins are simulated at four temperatures: 300 K, 373 K, 473 K (two sets), and 500 K; the various simulations extended from 200 ps to 1,020 ps. At room temperature, the two proteins are stable, remain close to the crystal structure, and exhibit similar dynamic behavior; the RMS residue fluctuations are slightly smaller in the hyperthermophilic protein. An analysis of the average energy contributions in the two proteins is made; the results suggest that the intraprotein energy stabilizes RdPf relative to RdDv. At 373 K, the mesophilic protein unfolds rapidly (it begins to unfold at 300 ps), whereas the hyperthermophilic does not unfold over the simulation of 600 ps. This is in accord with the expected stability of the two proteins. At 473 K, where both proteins are expected to be unstable, unfolding behavior is observed within 200 ps and the mesophilic protein unfolds faster than the hyperthermophilic one. At 500 K, both proteins unfold; the hyperthermophilic protein does so faster than the mesophilic protein. The unfolding behavior for the two proteins is found to be very similar. Although the exact order of events differs from one trajectory to another, both proteins unfold first by opening of the loop region to expose the hydrophobic core. This is followed by unzipping of the β‐sheet. The results obtained in the simulation are discussed in terms of the factors involved in flexibility and thermostability.
Fcγ Receptor Heterogeneity in Leukocyte Functional Responses

Antibodies participate in defense of the organism from all types of pathogens, including viruses, bacteria, fungi, and protozoa. IgG antibodies recognize their associated antigen via their two Fab portions and are in turn recognized though their Fc portion by specific Fcγ receptors (FcγRs) on the membrane of immune cells. Multiple types and polymorphic variants of FcγR exist. These receptors are expressed in many cells types and are also redundant in inducing cell responses. Crosslinking of FcγR on the surface of leukocytes activates several effector functions aimed toward the destruction of pathogens and the induction of an inflammatory response. In the past few years, new evidence on how the particular IgG subclass and the glycosylation pattern of the antibody modulate the IgG–FcγR interaction has been presented. Despite these advances, our knowledge of what particular effector function is activated in a certain cell and in response to a specific type of FcγR remains very limited today. On one hand, each immune cell could be programmed to perform a particular cell function after FcγR crosslinking. On the other, each FcγR could activate a particular signaling pathway leading to a unique cell response. In this review, I describe the main types of FcγRs and our current view of how particular FcγRs activate various signaling pathways to promote unique leukocyte functions.
A Unified Method to Detect Transistor Stuck-Open Faults and Transition Delay Faults

Detection of transistor stuck-open faults in CMOS circuits requires two-pattern tests. Transition delay fault model is commonly used to model delay causing defects and it also requires two-pattern tests. In this paper we examine the relationship between the two fault models and propose a method for generating test patterns that achieve maximum coverage of both faults. In the proposed method we use an ATPG program for transition delay faults to generate test patterns for both faults. Experimental results are presented to evaluate the effectiveness of our approach
Quantitative proteomics of rat livers shows that unrestricted feeding is stressful for proteostasis with implications on life span

Studies in young mammals on the molecular effects of food restriction leading to prolong adult life are scares. Here, we used high-throughput quantitative proteomic analysis of whole rat livers to address the molecular basis for growth arrest and the apparent life-prolonging phenotype of the food restriction regimen. Over 1800 common proteins were significantly quantified in livers of ad libitum, restriction- and re-fed rats, which summed up into 92% of the total protein mass of the cells. Compared to restriction, ad libitum cells contained significantly less mitochondrial catabolic enzymes and more cytosolic and ER HSP90 and HSP70 chaperones, which are hallmarks of heat- and chemically-stressed tissues. Following re-feeding, levels of HSPs nearly reached ad libitum levels. The quantitative and qualitative protein values indicated that the restriction regimen was a least stressful condition that used minimal amounts of HSP-chaperones to maintain optimal protein homeostasis and sustain optimal life span. In contrast, the elevated levels of HSP-chaperones in ad libitum tissues were characteristic of a chronic stress, which in the long term could lead to early aging and shorter life span.
The Pattern of Fatty Acids Displaced by EPA and DHA Following 12 Months Supplementation Varies between Blood Cell and Plasma Fractions

Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are increased in plasma lipids and blood cell membranes in response to supplementation. Whilst arachidonic acid (AA) is correspondingly decreased, the effect on other fatty acids (FA) is less well described and there may be site-specific differences. In response to 12 months EPA + DHA supplementation in doses equivalent to 0–4 portions of oily fish/week (1 portion: 3.27 g EPA+DHA) multinomial regression analysis was used to identify important FA changes for plasma phosphatidylcholine (PC), cholesteryl ester (CE) and triglyceride (TAG) and for blood mononuclear cells (MNC), red blood cells (RBC) and platelets (PLAT). Dose-dependent increases in EPA + DHA were matched by decreases in several n-6 polyunsaturated fatty acids (PUFA) in PC, CE, RBC and PLAT, but were predominantly compensated for by oleic acid in TAG. Changes were observed for all FA classes in MNC. Consequently the n-6:n-3 PUFA ratio was reduced in a dose-dependent manner in all pools after 12 months (37%–64% of placebo in the four portions group). We conclude that the profile of the FA decreased in exchange for the increase in EPA + DHA following supplementation differs by FA pool with implications for understanding the impact of n-3 PUFA on blood lipid and blood cell biology.
Representation learning for relational data

The increasing use of social and sensor networks generates a large quantity of data that can be represented as complex graphs. There are many tasks from information analysis, to prediction and retrieval one can imagine on those data where relation between graph nodes should be informative. In this thesis, we proposed different models for three different tasks: - Graph node classification - Relational time series forecasting - Collaborative filtering. All the proposed models use the representation learning framework in its deterministic or Gaussian variant. First, we proposed two algorithms for the heterogeneous graph labeling task, one using deterministic representations and the other one Gaussian representations. Contrary to other state of the art models, our solution is able to learn edge weights when learning simultaneously the representations and the classifiers. Second, we proposed an algorithm for relational time series forecasting where the observations are not only correlated inside each series, but also across the different series. We use Gaussian representations in this contribution. This was an opportunity to see in which way using Gaussian representations instead of deterministic ones was profitable. At last, we apply the Gaussian representation learning approach to the collaborative filtering task. This is a preliminary work to see if the properties of Gaussian representations found on the two previous tasks were also verified for the ranking one. The goal of this work was to then generalize the approach to more relational data and not only bipartite graphs between users and items.
Early Signs of Memory Impairment among Multiple Sclerosis Patients with Clinically Isolated Syndrome

The study investigates primary and secondary verbal memory and motor/executive functions (response inhibition and strategy shifting ability) in multiple sclerosis (MS) patients with clinically isolated syndrome (CIS). We studied 44 CIS patients and compared them to 49 patients with relapsing remitting MS (RR-MS) displaying mild disability and to a large cohort of age- and education level-matched healthy volunteers (n = 230). Results showed that both CIS and RR-MS patients evidenced a disproportionate impairment in the immediate and delayed recall of the second (as compared to the first) of two short narratives of the Logical Memory WMS-III subtest, and reduced performance on the Memory for Digits-Forward. Performance of either group on the executive tasks was not impaired, showing evidence of a reversed speed-accuracy trade-off. Illness duration emerged as a significant predictor of memory and executive task performance. Clinical, psychoemotional, and brain imaging findings were also examined as potential correlates of memory deficits and disease progression among CIS patients. These findings may signify early-onset decline of specific cognitive functions in CIS, which merits regular follow-up assessments and monitoring of psychoemotional adaptation and everyday functioning.
Serotypes and Antimicrobial Resistance in Salmonella enterica Recovered from Clinical Samples from Cattle and Swine in Minnesota, 2006 to 2015

Salmonellosis remains one of the leading causes of foodborne disease worldwide despite preventive efforts at various stages of the food production chain. The emergence of multi-drug resistant (MDR) non-typhoidal Salmonella enterica represents an additional challenge for public health authorities. Food animals are considered a major reservoir and potential source of foodborne salmonellosis; thus, monitoring of Salmonella strains in livestock may help to detect emergence of new serotypes/MDR phenotypes and to gain a better understanding of Salmonella epidemiology. For this reason, we analyzed trends over a nine-year period in serotypes, and antimicrobial resistance, of Salmonella isolates recovered at the Minnesota Veterinary Diagnostic Laboratory (MVDL) from swine (n = 2,537) and cattle (n = 1,028) samples. Prevalence of predominant serotypes changed over time; in swine, S. Typhimurium and S. Derby decreased and S. Agona and S. 4,5,12:i:- increased throughout the study period. In cattle, S. Dublin, S. Montevideo and S. Cerro increased and S. Muenster became less frequent. Median minimum inhibitory concentration (MIC) values and proportion of antibiotic resistant isolates were higher for those recovered from swine compared with cattle, and were particularly high for certain antibiotic-serotype combinations. The proportion of resistant swine isolates was also higher than observed in the NARMS data, probably due to the different cohort of animals represented in each dataset. Results provide insight into the dynamics of antimicrobial resistant Salmonella in livestock in Minnesota, and can help to monitor emerging trends in antimicrobial resistance.