Quantifying Performance Costs of Database Fine-Grained Access Control

Fine-grained access control is a conceptual approach to addressing database security requirements. In relational database management systems, fine-grained access control refers to access restrictions enforced at the row, column, or cell level. While a number of commercial implementations of database fine-grained access control are available, there are presently no generalized approaches to implementing fine-grained access control for relational database management systems. Fine-grained access control is potentially a good solution for database professionals and system architects charged with designing database applications that implement granular security or privacy protection features. However, in the oral tradition of the database community, fine-grained access control is spoken of as imposing significant performance penalties, and is therefore best avoided. Regardless, there are current and emerging social, legal, and economic forces that mandate the need for efficient fine-grained access control in relational database management systems. In the study undertaken, the author was able to quantify the performance costs associated with four common implementations of fine-grained access control for relational database management systems. Security benchmarking was employed as the methodology to quantify performance costs. Synthetic data from the TPC-W benchmark as well as representative data from a real-world application were utilized in the benchmarking process. A simple graph-base performance model for Fine-grained Access Control Evaluation (FACE) was developed from benchmark data collected during the study. The FACE model is intended for use in predicting throughput and response times for relational database management systems that implement fine-grained access control using one of the common fine-grained access control mechanisms - authorization views, the Hippocratic Database, label-based access control, and transparent query rewrite. The author also addresses the issue of scalability for fine-grained access control mechanisms that were evaluated in the study

A paralog of a bacteriochlorophyll biosynthesis enzyme catalyzes the formation of 1,2-dihydro-carotenoids in green sulfur bacteria

Chlorobaculum tepidum, a green sulfur bacterium, utilizes chlorobactene as its major carotenoid, and this organism also accumulates a reduced form of this monocyclic pigment, 1',2'-dihydrochlorobactene. The protein catalyzing this reduction is the last unidentified enzyme in the biosynthetic pathways for all of the green sulfur bacterial pigments used for photosynthesis. The genome of Chlorobaculum tepidum contains two paralogous genes encoding members of the FixC family of flavoproteins: bchP, that has been shown to encode an enzyme of bacteriochlorophyll biosynthesis; and bchO, for which a function has not been assigned. Here we demonstrate that a bchO mutant is unable to synthesize 1',2'-dihydrochlorobactene, and when bchO is heterologously expressed in a neurosporene-producing mutant of the purple bacterium, Rhodobactersphaeroides, the encoded protein is able to catalyze the formation of 1,2-dihydroneurosporene, the major carotenoid of the only other organism reported to synthesize 1,2-dihydrocarotenoids, Blastochloris viridis Identification of this enzyme completes the pathways for the synthesis of photosynthetic pigments in Chlorobiaceae, and accordingly and consistent with its role in carotenoid biosynthesis, we propose to rename the gene, cruI Notably, the absence of cruI in Blastochloris viridis indicates that a second 1,2-carotenoid reductase, which is structurally unrelated to CruI (BchO), must exist in nature. The evolution of this carotenoid reductase in green sulfur bacteria is discussed herein

The relationship of state and trait anxiety with the processing of affective stimuli based on the Stroop task paradigm: lexical and facial version.

Celem prezentowanej pracy było zbadanie tendencyjności kierowania uwagi na zagrożenie w zdrowej, niezdiagnozowanej zaburzeniami lękowymi, populacji. Emocjonalny paradygmat Stroopa zastosowano w dwóch wariantach: leksykalnym (słowo-kolor) i twarzowym (słowo-twarz). Postawiono hipotezę, że w leksykalnym zadaniu emocjonalnym Stroopa efekt interferencji emocjonalnej jest modulowany przez podniecenie, a nie walencję. Aby przetestować to założenie, wybrane słowa afektywne były równie pobudzające, jednakże bardziej pobudzające niż neutralne. Uzyskane wyniki nie wykazały efektu pobudzenia w wywoływaniu efektu interferencji emocjonalnej. Drugim zadaniem w badaniu było emocjonalne zadanie Stroopa w wariancie twarzowym. Na twarze przedstawiające emocje smutku, strachu, gniewu i radości zostały nałożone zostały słowa: „smutek”, „gniew”, „strach”, radość” i „XXX”. Otrzymane wyniki potwierdziły hipotezę, zgodnie z którą słowa o negatywnym wydźwięku umieszczone na twarzy wywołują efekt automatycznej czujności, podczas gdy pozytywne słowa i „XXX” takiego efektu nie powodują. Wykazano również tzw. efekt ułatwienia; czasy reakcji były znacznie szybsze podczas prób zgodnych w porównaniu do tych niespójnych. Podsumowując, obecne badanie popiera kategoryczną teorię negatywności i hipotezę o ewolucyjnym zagrożeniu. Wskazuje również na znaczenie doboru materiału leksykalnego, podczas prób naukowej weryfikacji teorii pobudzenia. Wreszcie, celem tej pracy było również zbadanie związku między efektem interferencji emocjonalnej a lękiem jako cechą i stanem. Modele regresji skonstruowane dla obu zadań nie wykazały istotnego związku między tymi zmiennymi.The purpose of this thesis was to investigate the attentional bias towards threat in a healthy, undiagnosed with anxiety, sample. The emotional Stroop paradigm was used in two variants: lexical (word-colour) and facial (face-word). It has been hypothesized that in the lexical emotional Stroop task, the emotional interference effect is modulated by arousal, not valence. To test this presumption, the affective words selected were equally arousing, yet more arousing than neutral ones. The results obtained revealed no effect of arousal in producing the emotional interference effect. The second task in the study was the face-word emotional Stroop task. The faces depicting emotions of sadness, fear, anger and happiness were presented with Polish equivalents of words “sadness”, “anger”, “fear”, “happiness” and “XXX” being superimposed on the images. The findings confirmed the hypothesis claiming that negatively valenced words placed across the face elicit the effect of automatic vigilance, whereas positive words and non-word “XXX” do not. The Stroop-like facilitation effect has also been demonstrated; the response latencies were significantly faster on the congruent trials as compared to the incongruent ones. Overall, the present study supports the categorical negativity theory and evolutionary threat hypothesis. It also points out the importance of lexical material selection while seeking out to scientifically validate the arousal theory. Lastly, the objective of this thesis was to explore the relationship between the emotional interference effect as well as trait and state anxiety. The regression models constructed for both tasks revealed no significant relationship between those variables

L'Écho : grand quotidien d'information du Centre Ouest

02 janvier 19431943/01/02 (A72,N384)-1943/01/03.Appartient à l’ensemble documentaire : PoitouCh

Additional file 4: Table S4. of Analysis of the FnrL regulon in Rhodobacter capsulatus reveals limited regulon overlap with orthologues from Rhodobacter sphaeroides and Escherichia coli

FnrL predicted binding site based on PWM with corresponding RNA-seq expression change. (DOCX 165 kb

No indication that the ego depletion manipulation can affect insight : a comment on DeCaro and Van Stockum (2018)

Recently, DeCaro and Van Stockum have suggested that ego depletion following intensive self-control can improve insight problem-solving; this finding was interpreted in terms of insight relying on decreased control over attention and memory. However, DeCaro and Van Stockum used three variants of the single matchstick arithmetic problem. Experiment 1 involved low sample and non-standard problem application, while the more powered Experiment 2 yielded a surprisingly low solution rate. These facts made both studies problematic and called for their replication. In the two present studies, the DeCaro and Van Stockum ego-depletion manipulation and their matchstick problems were administered to a total of 316 people. Furthermore, various other insight problems, subjective ratings of insight experience, analytical problems and executive control tests were applied. The key result was that no reliable effect of ego depletion could be found for any of these measures