Agile distributed software development: enacting control through media and context

While face‐to‐face interaction is fundamental in agile software development, distributed environments must rely extensively on mediated interactions. Practicing agile principles in distributed environments therefore poses particular control challenges related to balancing fixed vs. evolving quality requirements and people vs. process‐based collaboration. To investigate these challenges, we conducted an in‐depth case study of a successful agile distributed software project with participants from a Russian firm and a Danish firm. Applying Kirsch's elements of control framework, we offer an analysis of how control was enacted through the project context and in the participants' mediated communication. The analysis reveals that formal measurement and evaluation control were persistently enacted through mediated communication. These formal control practices were, however, predominantly carried out in conjunction with informal roles and relationships such as clan‐like control inherent in agile development. Overall, the study demonstrates that, if appropriately applied, communication technologies can significantly support distributed, agile practices by allowing concurrent enactment of both formal and informal controls. The paper discusses these findings as they relate to previous research and concludes with their implications for future research.     

MS Binding Assays for Glycine Transporter 2 (GlyT2) Employing Org25543 as Reporter Ligand

This study describes the first binding assay for glycine transporter 2 (GlyT2) following the concept of MS Binding Assays. The selective GlyT2 inhibitor Org25543 was employed as a reporter ligand and it was quantified with a highly sensitive and rapid LC-ESI-MS/MS method. Binding of Org25543 at GlyT2 was characterized in kinetic and saturation experiments with an off-rate of 7.07×10⁻³ s⁻¹, an on-rate of 1.01×10⁶ M⁻¹ s⁻¹, and an equilibrium dissociation constant of 7.45 nM. Furthermore, the inhibitory constants of 19 GlyT ligands were determined in competition experiments. The validity of the GlyT2 affinities determined with the binding assay was examined by a comparison with published inhibitory potencies from various functional assays. With the capability for affinity determination towards GlyT2 the developed MS Binding Assays provide the first tool for affinity profiling of potential ligands and it represents a valuable new alternative to functional assays addressing GlyT2.     

Effect of Density and Processing Conditions on Oxide Transformations and Mechanical Properties in Cr–Mo-Alloyed PM steels

To improve the mechanical properties and performances of water-atomized powder metallurgy steels, it is necessary to enhance the density. Consolidating water-atomized steel powders via conventional pressing and sintering to a relative density level > 95 pct involves processing challenges. Consolidation of gas-atomized powders to full density by hot isostatic pressing (HIP) is an established process route but utilizing water-atomized powders in HIP involves challenges that result in the formation of prior particle boundaries due to higher oxygen content. In this study, the effect of density and processing conditions on the oxide transformations and mechanical properties from conventional press and sintering, and HIP are evaluated. Hence, water-atomized Cr–Mo-alloyed powder is used and consolidated into different density levels between 6.8 and 7.3 g cm⁻³ by conventional die pressing and sintering. Fully dense material produced through HIP is evaluated not only of mechanical properties but also for microstructural and fractographic analysis. An empirical model based on power law is fitted to the sintered material properties to estimate and predict the properties up to full density at different sintering conditions. A model describing the mechanism of oxide transformation during sintering and HIP is proposed. The challenges when it comes to the HIP of water-atomized powder are addressed and the requirements for successful HIP processing are discussed.

     

Good ergonomics and team diversity reduce absenteeism and errors in car manufacturing

Prior research suggests that ergonomics work design and mixed teams (in age and gender) may compensate declines in certain abilities of ageing employees. This study investigates simultaneous effects of both team level factors on absenteeism and performance (error rates) over one year in a sample of 56 car assembly teams (N = 623). Results show that age was related to prolonged absenteeism and more mistakes in work planning, but not to overall performance. In comparison, high-physical workload was strongly associated with longer absenteeism and increased error rates. Furthermore, controlling for physical workload, age diversity was related to shorter absenteeism, and the presence of females in the team was associated with shorter absenteeism and better performance. In summary, this study suggests that both ergonomics work design and mixed team composition may compensate age-related productivity risks in manufacturing by maintaining the work ability of older employees and improving job quality.     

Modification of margarine fats by enzymatic interesterification: Evaluation of a solid-fat-content-based exponential model with two groups of oil blends

Lipozyme TL IM-catalyzed interesterification for the modification of margarine fats was carried out in a batch reactor at 70°C with a lipase dosage of 4%. Solid fat content (SFC) was used to monitor the reaction progress. Lipase-catalyzed interesterification, which led to changes in the SFC, was assumed to be a first-order reversible reaction. Accordingly, the change in SFC vs. reaction time was described by an exponential model. The model contained three parameters, each with a particular physical or chemical meaning: (i) the initial SFC (SFC₀), (ii) the change in SFC (ΔSFC) from the initial to the equilibrium state, and (iii) the reaction rate constant value (k). SFC_o and ΔSFC were related to only the types of blends and the blend ratios. The rate constant k was related to lipase activity on a given oil blend. Evaluation of the model was carried out with two groups of oil blends, i.e., palm stearin/coconut oil in weight ratios of 90∶10, 80∶20, and 70∶30, and soybean oil/fully hydrogenated soybean oil in weight ratios of 80∶20, 65∶35, and 50∶50. Correlation coefficients higher than 0.99 between the experimental and predicted values were observed for SFC at temperatures above 30°C. The model is useful for predicting changes in the SFC during lipase-catalyzed interesterification with a selected group of oil blends. It also can be used to control the process when particular SFC values are targeted.     

In Situ EXAFS Study on the Chemical State of Arsenic Deposited on a NiMoP/Al2O3 Hydrotreating Catalyst

The chemical state of arsenic deposited on a NiMoP/Al₂O₃ hydrotreating catalyst exposed to ppb levels of arsenic over several years in a refinery reactor has been studied by in situ EXAFS. In the as-received As-NiMoP catalyst, arsenic is exclusively coordinated to oxygen atoms. Upon sulfiding the sample in 2%H₂S/2%H₂/96%He, the As atoms become surrounded by approximately two sulfur atoms. No evidence was found for Ni–As bond formation. A possible model for the As local environment is suggested on the basis of combined EXAFS results, STM data and FEFF8.0 simulations (program for ab initio calculations on multiple scattering XAFS and XANES). The FEFF8.0 simulations of the proposed model are in accord with the experimental data measured at the As K edge. In this model, an As atom is located at the edge of a hexagonally truncated Ni-MoS₂ slab and is blocking the active NiMoS site.     

FT-IR spectroscopic study of hydrogen bonding in PA6/clay nanocomposites

Fourier transform infrared spectroscopy was used to investigate PA6/clay nanocomposites (PA6CN) with various cooling histories from the melt, including rapid cooling (water-quenched), middle-rate cooling (air-cooling) and slow cooling (mold-cooling). In contrast to pure PA6 dominated by the α-phase, the addition of clay silicate layers favor the formation of the γ-crystalline phase in PA6CN.We focus on the reason why silicate layers favor the formation of γ-phase in PA6. Vaia et al. suggested that the addition of clay layers forces the amide groups of PA6 out of the plane formed by the chains. This results in conformational changes of the chains, which limits the formation of H-bonded sheets so that the γ-phase is favored. If this assumption is correct, PA6CN is expected to show some differences as compared with PA6 with respect to hydrogen bonding.The silicate layers were indeed found to weaken the hydrogen bonding both in the α- and γ-phases. This was also confirmed by X-ray diffraction studies. The γ-phase is most likely concentrated in regions close to the silicate layers, whereas the α-phase is favored in the bulk matrix.     

An XPS study of dispersion and valence state of TiO2 supported vanadium oxide catalysts

Monolayer vanadium species are mainly in the V(V) valence state, but with XPS a small fraction of V⁴⁺ species are identified. Prolonged analysis treatment increases the V⁴⁺ concentration. With increasing vanadium concentration, a monolayer coverage corresponding to 1 mg V₂O₅ per m² develops, and it contains additional layers with a thickness of about 250 Å at 4 mg V₂O₅ per m², covering 3% of its surface area.     

Interactions between immunoglobulin-like and catalytic modules in Clostridium thermocellum cellulosomal cellobiohydrolase CbhA

Cellobiohydrolase CbhA from Clostridium thermocellum cellulosome is a multi-modular protein composed starting from the N-terminus of a carbohydrate-binding module (CBM) of family 4, an immunoglobulin(Ig)-like module, a catalytic module of family 9 glycoside hydrolases (GH9), X1(1) and X1(2) modules, a CBM of family 3 and a dockerin module. Deletion of the Ig-like module from the Ig-GH9 construct results in complete inactivation of the GH9 module. The crystal structure of the Ig-GH9 module pair reveals the existence of an extensive module interface composed of over 40 amino acid residues of both modules and maintained through a large number of hydrophilic and hydrophobic interactions. To investigate the importance of these interactions between the two modules, we compared the secondary and tertiary structures and thermostabilities of the individual Ig-like and GH9 modules and the Ig-GH9 module pair using both circular dichroism (CD) spectroscopy and differential scanning calorimetry (DSC). Thr230, Asp262 and Asp264 of the Ig-like module are located in the module interface of the Ig-GH9 module pair and are suggested to be important in 'communication' between the modules. These residues were mutated to alanyl residues. The structure, stability and catalytic properties of the native Ig-GH9 and its D264A and T230A/D262A mutants were compared. The results indicate that despite being able to fold relatively independently, the Ig-like and GH9 modules interact and these interactions affect the final fold and stability of each module. Mutations of one or two amino acid residues lead to destabilization and change of the mechanism of thermal unfolding of the polypeptides. The enzymatic properties of native Ig-GH9, D264A and T230A/D262A mutants are similar. The results indicate that inactivation of the GH9 module occurs as a result of multiple structural disturbances finally affecting the topology of the catalytic center.