Industry 4.0: a supply chain innovation perspective

The Fourth Industrial Revolution – also known as Industry 4.0 (i4.0) – comprises the digitalisation of the industrial sector. This paper uses the theoretical lens of supply chain innovation (SCI) to investigate the implications of i4.0 on supply chain management. For these purposes, the method of structured content analysis is applied to more than 200 use cases of i4.0-enabled SCI introduced by both established and startup companies. i4.0-enabled SCI manifests along three dimensions: process, technology, and business architecture. The key findings of this study can be summarised as follows: first, i4.0-enabled SCI extends the initial focus on productivity improvements in SC processes towards scalability and flexibility. Second, extant i4.0 solutions rely mostly on analytics and smart things while omitting smart people technology and the human-centric approach associated with the i4.0 paradigm. Third, established companies adopt i4.0 merely to sustain their existing business architectures while startup companies radically change their operating models, relying heavily on data analytics and the platform economy. Consequently, established companies pursue a problem-driven, engineering-based approach to SCI while startup companies follow an ‘asset-light’, business-driven approach. Lastly, there are two distinct approaches to digitalising operational SC processes: platform-based crowdsourcing of standard processes and on-demand provision of customised services.     

Risk factors for a medically inappropriate admission to a Department of Internal Medicine

OBJECTIVE: To identify patient- and admission-related risk factors for a medically inappropriate admission to a department of internal medicine. METHODS: Cross-sectional study of a systematic sample of 500 admissions to the department of internal medicine of an urban teaching hospital. The appropriateness of each admission and reasons for inappropriate admissions were assessed using the Appropriateness Evaluation Protocol. Risk factors included the time (day of week and holidays) and manner (through emergency department or direct admission) of admission, patient age and sex, health status of patient and spouse, living arrangements, formal home care services, and informal support from family or friends. RESULTS: Overall, 76 (15.2%) hospital admissions were rated as medically inappropriate by the Appropriateness Evaluation Protocol. In multivariate analysis, the likelihood of an inappropriate admission was increased by better physical functioning of the patient (odds ratio [OR], 1.5; 95% confidence interval [CI], 1.1-2.1 [for 1 SD in Physical Functioning scores]), lower mental health status of the patient's spouse (OR, 2.6; 95% CI, 1.3-5.6), receipt of informal help from family or friends (OR, 3.3; 95% CI, 1.5-7.2), and hospitalization by one's physician (OR, 3.6; 95% CI, 1.7-7.5). Receiving formal adult home care was not associated with inappropriateness of hospitalization. CONCLUSIONS: Inappropriate admissions to internal medicine wards are determined by a mix of factors, including the patient's health and social environment. In addition, the private practitioners' discretionary ability to hospitalize their patients directly may also favor medically inappropriate admissions.     

The ability of the rat to metabolize myristoyl-methionine: an acylamino acid with potentially useful antibacterial properties

Two experiments with Sprague Dawley rats tested their ability to hydrolyse myristoyl-methionine (M-M) into myristic acid and L-methionine (M). In the first experiment, lasting for 3 days. male rats were orally administered [9,10-3H]myristoyl-L-[35S]methionine. The recovery of radioactivity was approximately 90% for both isotopes; 19% of the administered 3H was recovered in the urine and 16% in the faeces, while the recovered 35S activity was 13 and 12%, respectively. The balance of the radioactivity was found among the tissues, organs and blood. In the second experiment, male and female rats received soybean-based diets which were supplemented with either 0.305% M-M or 0.2% M (both diets contained equal amounts of M) for periods up to 4 weeks. The growth rate of the rats receiving the 0.305% M-M diets was slightly slower than that for the rats on the 0.2% M diet, but the difference was not statistically significant (P > 0.05). The M-M rats had a transitory decrease in feed consumption, suggesting that palatability may have contributed to the growth difference and that a somewhat greater amount of M-M was necessary for the rat to attain the same growth rate as that produced by 0.2% M. When the amount of dietary M-M was increased to 3.05% M-M, a greater reduction in feed consumption and body weight gain was observed. This latter diet was an initial attempt to study the potential toxicity of M-M. None of the haematological, clinical chemistry or organ weight data suggested that M-M was overtly toxic per se, but longer-term feeding studies are needed to evaluate the potential toxicity of M-M more fully.     

Kinetic analysis of the coding properties of O6-methylguanine in DNA: the crucial role of the conformation of the phosphodiester bond

Production by N-nitroso compounds of O6-alkylguanine (O6-alkylG) in DNA directs the misincorporation of thymine during DNA replication, leading to G:C to A:T transition mutations, despite the fact that DNA containing O6-alkylG:T base pairs is less stable than that containing O6-alkylG:C pairs. We have examined the kinetics of incorporation by Klenow fragment (KF) of Escherichia coli DNA polymerase I of thymine (T) and of cytosine (C) opposite O6-MeG in the template DNA strand. Both T and C were incorporated opposite O6-MeG much slower than nucleotides forming regular A:T or G:C base pairs. Using various concentrations of dTTP, dCTP, or their phosphorothioate (Sp)-dNTP alpha S analogues, or a mixture of dTTP and dCTP, the progress of incorporation of a single nucleotide in a single catalytic cycle of a preformed KF-DNA complex was measured (pre-steady-state kinetics). The results were consistent with the kinetic scheme (Kuchta, R. D., Benkovic, P., & Benkovic, S. J. (1988) Biochemistry 27, 6716-6725): (1) binding of dNTP to polymerase-DNA; (2) conformational change in polymerase; (3) formation of phosphodiester between the dNTP and the 3'-OH of the primer; (4) conformational change of polymerase; (5) release of pyrophosphate. The results were analyzed mathematically to identify the steps at which the rate constants differ significantly between the incorporation of T and C. The only significant difference was the 5-fold difference in the rates of formation of the phosphodiester bond (for dTTP, kforward = 3.9 s-1 and kback = 1.9 s-1; for dCTP, kforward = 0.7 s-1 and kback = 0.9 s-1). These pre-steady-state progress curves were biphasic with a rapid initial burst followed by an apparently steady-state rise. Deconvolution of these curves gave direct evidence for the importance of the conformational change after polymerization by showing that the curves represented the sum of the rapid accumulation of the product of step 3 followed by the slow conversion of that to the product of step 5 (because of the rapidity of the release of pyrophosphate there was no significant accumulation of the product of step 4). The equilibrium constants for each step suggest that the greatest change in the Gibbs free energy occurs at the conformational change after polymerization and that while the formation of the phosphodiester bond to T is slightly exothermic, that to C is slightly endothermic.(ABSTRACT TRUNCATED AT 400 WORDS)     

Introduction of a nonlinearity measure for principal component models

Although principal component analysis (PCA) is an important tool in standard multivariate data analysis, little interest has been devoted to assessing whether the underlying relationship within a given variable set can be described by a linear PCA model or whether nonlinear PCA must be utilized. This paper addresses this deficiency by introducing a nonlinearity measure for principal component models. The measure is based on the following two principles: (i) the range of recorded process operation is divided into smaller regions; and (ii) accuracy bounds are determined for the sum of the discarded eigenvalues. If this sum is within the accuracy bounds for each region, the process is assumed to be linear and vice versa. This procedure is automated through the use of cross-validation. Finally, the paper shows the utility of the new nonlinearity measure using two simulation studies and with data from an industrial melter process.     

Cr-Mo solid solutions forced by high-energy ball milling

Mixtures of Cr and Mo elemental powders, with the nominal compositions Cr₂₅Mo₇₅, Cr₅₀Mo₅₀, and Cr₇₅Mo₂₅, are processed by high-energy ball milling at ambient temperature. Milling is observed to force the mixing of the immiscible bcc elements Cr and Mo into solid solutions. The lattice parameter of these solid solutions, measured by X-ray diffraction (XRD), displays the expected positive deviation from Vegard’s law. These deviations are compared to the ones predicted by Eshelby’s inclusion model for dilute alloys. The conventional Williamson-Hall approach is shown to fail to determine the grain size in as-milled samples, probably due to the high density of dislocations. Annealing at 700 °C for 10 hours under argon leads to a large reduction in structural defect density, without inducing any significant decomposition. The mixing measured in Cr-Mo is discussed in the broader context of the mechanical mixing forced by ball milling in moderately immiscible systems.     

Crystal structure of tyrosine hydroxylase at 2.3 A and its implications for inherited neurodegenerative diseases

Tyrosine hydroxylase (TyrOH) catalyzes the conversion of tyrosine to L-DOPA, the rate-limiting step in the biosynthesis of the catecholamines dopamine, adrenaline, and noradrenaline. TyrOH is highly homologous in terms of both protein sequence and catalytic mechanism to phenylalanine hydroxylase (PheOH) and tryptophan hydroxylase (TrpOH). The crystal structure of the catalytic and tetramerization domains of TyrOH reveals a novel alpha-helical basket holding the catalytic iron and a 40 A long anti-parallel coiled coil which forms the core of the tetramer. The catalytic iron is located 10 A below the enzyme surface in a 17 A deep active site pocket and is coordinated by the conserved residues His 331, His 336 and Glu 376. The structure provides a rationale for the effect of point mutations in TyrOH that cause L-DOPA responsive parkinsonism and Segawa's syndrome. The location of 112 different point mutations in PheOH that lead to phenylketonuria (PKU) are predicted based on the TyrOH structure.     

Interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd0.96Zn0.04 Te (211)B substrates by molecular beam epitaxy

Double-crystal x-ray rocking curve (DCRC) and secondary-ion mass-spectroscopy (SIMS) measurements have been performed to investigate the effect of rapid thermal annealing on the interdiffusion behavior of Hg in HgTe/CdTe superlattices grown on Cd_0.96Zn_0.04Te (211)B substrates by molecular beam epitaxy. The sharp satellite peaks of the DCRC measurements on a 100-period HgTe/CdTe (100Å/100Å) superlattice show a periodic arrangement of the superlattice with high-quality interfaces. The negative direction of the entropy change obtained from the diffusion coefficients as a function of the reciprocal of the temperature after RTA indicates that the Hg diffusion for the annealed HgTe/CdTe superlattice is caused by an interstitial mechanism. The Cd and the Hg concentration profiles near the annealed HgTe/CdTe superlattice interfaces, as measured by SIMS, show a nonlinear behavior for Hg, originating from the interstitial diffusion mechanism of the Hg composition. These results indicate that a nonlinear interdiffusion behavior is dominant for HgTe/CdTe superlattices annealed at 190°C and that the rectangular shape of HgTe/CdTe superlattices may change to a parabolic shape because of the intermixing of Hg and Cd due to the thermal treatment.     

Measurement of Energy Expenditure in Elite Athletes Using MEMS-Based Triaxial Accelerometers

Fitness development and performance assessment of elite athletes requires an understanding of many physiological factors, many of these are direct and indirect measures of athlete energy expenditure. Many methods are physiological factor assessments and require the athlete to be constrained by laboratory equipment or periodic interruption of activity to take measurements such as blood samples are required to be taken. This paper presents a method that is entirely ambulatory and noninvasive, using microelectromechanical systems (MEMS) accelerometers. The commonly used output of commercial accelerometer-based devices (known as "counts") cannot discriminate activity intensity for the activities of interest. This, in conjunction with variability in output from different systems and lack of commonality across manufacturers, limits the usefulness of commercial devices. This paper identifies anthropometric and kinematic sources of inter-athlete variability in accelerometer output, leading to an alternate energy expenditure estimator based mainly on step frequency modified by anthropometric measures. This energy expenditure estimator is more robust and not influenced by many sources of variability that affect the currently used estimator. In this system, low-power signal processing was implemented to extract both the energy estimator and other information of physiological and statistical interest