Balanced Locally Repairable Codes

We introduce a family of balanced locally repairable codes (BLRCs) $[n, k, d]$ for arbitrary values of $n$, $k$ and $d$. Similar to other locally repairable codes (LRCs), the presented codes are suitable for applications that require a low repair locality. The novelty that we introduce in our construction is that we relax the strict requirement the repair locality to be a fixed small number $l$, and we allow the repair locality to be either $l$ or $l+1$. This gives us the flexibility to construct BLRCs for arbitrary values of $n$ and $k$ which partially solves the open problem of finding a general construction of LRCs. Additionally, the relaxed locality criteria gives us an opportunity to search for BLRCs that have a low repair locality even when double failures occur. We use metrics such as a storage overhead, an average repair bandwidth, a Mean Time To Data Loss (MTTDL) and an update complexity to compare the performance of BLRCs with existing LRCs.Comment: Accepted for presentation at International Symposium on Turbo Codes and Iterative Information Processing 201

General Sub-packetized Access-Optimal Regenerating Codes

This paper presents a novel construction of $(n,k,d=n-1)$ access-optimal regenerating codes for an arbitrary sub-packetization level $\alpha$ for exact repair of any systematic node. We refer to these codes as general sub-packetized because we provide an algorithm for constructing codes for any $\alpha$ less than or equal to $r^{\lceil \frac{k}{r} \rceil}$ where $\frac{k}{r}$ is not necessarily an integer. This leads to a flexible construction of codes for different code rates compared to existing approaches. We derive the lower and the upper bound of the repair bandwidth. The repair bandwidth depends on the code parameters and $\alpha$. The repair process of a failed systematic node is linear and highly parallelized, which means that a set of $\lceil \frac{\alpha}{r} \rceil$ symbols is independently repaired first and used along with the accessed data from other nodes to recover the remaining symbols

Allyl isothiocyanate inhibits actin mediated intracellular transport in Arabidopsis thaliana.

Volatile allyl isothiocyanate (AITC) derives from the biodegradation of the glucosinolate sinigrin and has been associated with growth inhibition in several plants, including the model plant Arabidopsis thaliana. However, the underlying cellular mechanisms of this feature remain scarcely investigated in plants. In this study, we present evidence of an AITC-induced inhibition of actin-dependent intracellular transport in A. thaliana. A transgenic line of A. thaliana expressing yellow fluorescent protein (YFP)-tagged actin filaments was used to show attenuation of actin filament movement by AITC. This appeared gradually in a time- and dose-dependent manner and resulted in actin filaments appearing close to static. Further, we employed four transgenic lines with YFP-fusion proteins labeling the Golgi apparatus, endoplasmic reticulum (ER), vacuoles and peroxisomes to demonstrate an AITC-induced inhibition of actin-dependent intracellular transport of or, in these structures, consistent with the decline in actin filament movement. Furthermore, the morphologies of actin filaments, ER and vacuoles appeared aberrant following AITC-exposure. However, AITC-treated seedlings of all transgenic lines tested displayed morphologies and intracellular movements similar to that of the corresponding untreated and control-treated plants, following overnight incubation in an AITC-absent environment, indicating that AITC-induced decline in actin-related movements is a reversible process. These findings provide novel insights into the cellular events in plant cells following exposure to AITC, which may further expose clues to the physiological significance of the glucosinolate-myrosinase system© 2015 by the authors; licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons by Attribution (CC-BY) license (http://creativecommons.org/licenses/by/4.0/)

Allyl-isothiocyanate treatment induces a complex transcriptional reprogramming including heat stress, oxidative stress and plant defence responses in Arabidopsis thaliana

Comparison of the transcriptional response to allyl-ITC with the CPR response. (XLSX 85 kb

Situational Factors Influencing Customers´ Credit Use Online: A Behavioral Economic Approach

This study investigates consumers´ credit use online from the perspective of intertemporal choice and focuses on the impact of personalized credit information when choosing utilitarian versus hedonic product. In a simulated shopping experiment, participants from a Norwegian university college could either save money for the product and get it in the future or buy the product on credit and get it now. A between-group design was used with a randomized selection divided into two groups. The test group (n=37) received personalized credit information while choosing the utilitarian and hedonic products. The control group (n=36) did not have this information. Area Under Curve was calculated and used to make statistical operations. Results show that all participants discounted the saving alternative when the time delay increased, which, therefore, increased their willingness to buy on credit online. Participants´ discounting of the saving alternative was near the hyperbolic model. Second, a significant difference between the utilitarian versus the hedonic products was found for all participants´ willingness to buy on credit online. Finally, personalized information about credit debt had little influence on credit use, but some indications related to hedonic product calls for further research. Implications for research and practice as well as suggestions for future studies are given

Diet and behavioral problems at school in Norwegian adolescents

Background: Discussion about dietary factors in relation to behavioral problems in children and adolescents has been going on for a long time. Objective: The aim of this study was to investigate the cross-sectional relation between diet and self-reported behavioral problems at school in adolescents in the southern part of Norway. Design: In total, 475 ninth- and tenth-grade students (236 boys and 239 girls) out of 625 eligible students from four different secondary schools in three different communities in Vest-Agder County, Norway, participated, giving a participation rate of 77%. The students filled in a questionnaire with food frequency questions of selected healthy (e.g. fruits, vegetables, and fish) and unhealthy (e.g. sweets, sugar-sweetened beverages, and crisps) food items, questions of meal frequency, and four questions regarding behavioral problems at school. Results: Having breakfast regularly was significantly associated with decreased odds of behavioral problems (OR: 0.29 (0.15-0.55), p ≤0.001). A high intake of unhealthy foods, such as sugar-sweetened soft drinks (OR: 2.8 (1.06-7.42), p=0.03) and sweets (OR: 2.63 (1.39-4.98), p=0.003), was significantly associated with increased odds of behavioral problems. At the same time, a high intake of fruits was associated with decreased odds of behavioral problems in Norwegian adolescents (OR: 0.30 (0.10-0.87), p=0.03). All ORs are adjusted for sex and BMI. Conclusions: This study shows that having an optimal diet and not skipping meals are associated with decreased odds of behavioral problems at school in Norwegian adolescents. Hence, it is important to improve the dietary intake and meal pattern of Norwegian adolescents. The cross-sectional design of this study limits any causal interpretations of the results of the study

Optimized submerged batch fermentation strategy for systems scale studies of metabolic switching in Streptomyces coelicolor A3(2)

Background: Systems biology approaches to study metabolic switching in Streptomyces coelicolor A3(2) depend on cultivation conditions ensuring high reproducibility and distinct phases of culture growth and secondary metabolite production. In addition, biomass concentrations must be sufficiently high to allow for extensive time-series sampling before occurrence of a given nutrient depletion for transition triggering. The present study describes for the first time the development of a dedicated optimized submerged batch fermentation strategy as the basis for highly time-resolved systems biology studies of metabolic switching in S. coelicolor A3(2). Results: By a step-wise approach, cultivation conditions and two fully defined cultivation media were developed and evaluated using strain M145 of S. coelicolor A3(2), providing a high degree of cultivation reproducibility and enabling reliable studies of the effect of phosphate depletion and L-glutamate depletion on the metabolic transition to antibiotic production phase. Interestingly, both of the two carbon sources provided, D-glucose and L-glutamate, were found to be necessary in order to maintain high growth rates and prevent secondary metabolite production before nutrient depletion. Comparative analysis of batch cultivations with (i) both L-glutamate and D-glucose in excess, (ii) L-glutamate depletion and D-glucose in excess, (iii) L-glutamate as the sole source of carbon and (iv) D-glucose as the sole source of carbon, reveal a complex interplay of the two carbon sources in the bacterium's central carbon metabolism. Conclusions: The present study presents for the first time a dedicated cultivation strategy fulfilling the requirements for systems biology studies of metabolic switching in S. coelicolor A3(2). Key results from labelling and cultivation experiments on either or both of the two carbon sources provided indicate that in the presence of D-glucose, L-glutamate was the preferred carbon source, while D-glucose alone appeared incapable of maintaining culture growth, likely due to a metabolic bottleneck at the oxidation of pyruvate to acetyl-CoA