A quantitative analysis of the unit verification perspective on fault distributions in complex software systems: an operational replication

Unit verification, including software inspections and unit tests, is usually the first code verification phase in the software development process. However, principles of unit verification are weakly explored, mostly due to the lack of data, since unit verification data are rarely systematically collected and only a few studies have been published with such data from industry. Therefore, we explore the theory of fault distributions, originating in the quantitative analysis by Fenton and Ohlsson, in the weakly explored context of unit verification in large-scale software development. We conduct a quantitative case study on a sequence of four development projects on consecutive releases of the same complex software product line system for telecommunication exchanges. We replicate the operationalization from earlier studies, analyzed hypotheses related to the Pareto principle of fault distribution, persistence of faults, effects of module size, and quality in terms of fault densities, however, now from the perspective of unit verification. The patterns in unit verification results resemble those of later verification phases, e.g., regarding the Pareto principle, and may thus be used for prediction and planning purposes. Using unit verification results as predictors may improve the quality and efficiency of software verification.     

Whole-body vibration transmitted to the framesaw operator

At the moment there are more than 40 framesaws in use in Croatia, and many framesaw operators have a serious spine problem. Complex measurements have been carried out in order to determine the vibration level on the operator's seat. This paper reports and analyzes the measurement results of the whole-body vibration transmitted to a framesaw operator during an ordinary working day. Vibrations were measured at all operations performed during the normal framesaw working cycle. For all the measurements frequency spectra were obtained and the results graphically represented according to the ISO 2631-1-1986 recommendations. The weighted r.m.s. acceleration was also calculated and the duration of each single framesaw operation was measured. The energy-equivalent vibration level, corresponding to the total duration of exposure was calculated, too. The values so obtained were compared with the daily exposure limits according to the ISO 2631-1-1997. The measurement results showed that the framesaw operator, under the given measuring conditions, is exposed to a higher vibration level than the given daily exposure limits. Also, the energy-equivalent vibration level calculated according to the guidelines given in the new ISO 2631-1-1997 is higher than the limits recommended for an effective 4-h daily exposure.     

Nanolocomotion—Catalytic Nanomotors and Nanorotors

Nature's nanomachines, built of dynamically integrated biochemical components, powered by energy‐rich biochemical processes, and designed to perform a useful task, have evolved over millions of years. They provide the foundation of all living systems on our planet today. Yet synthetic nanomotors, driven by simple chemical reactions and which could function as building blocks for synthetic nanomachines that can perform useful tasks, have been discovered only in the last few years. Why did it take so long to power‐up a myriad of synthetic nanostructures from their well‐known static states to new and exciting dynamic ones of the kind that abound in nature? This article will delve into this disconnect between the world of biological and abiological nanomotors, then take a look at some recent developments involving chemically powered nanoscale motors and rotors, and finally try to imagine: what's next for nanolocomotion?     

Viral Interactions with Adaptor-Protein Complexes: A Ubiquitous Trait among Viral Species

Numerous viruses hijack cellular protein trafficking pathways to mediate cell entry or to rearrange membrane structures thereby promoting viral replication and antagonizing the immune response. Adaptor protein complexes (AP), which mediate protein sorting in endocytic and secretory transport pathways, are one of the conserved viral targets with many viruses possessing AP-interacting motifs. We present here different mechanisms of viral interference with AP complexes and the functional consequences that allow for efficient viral propagation and evasion of host immune defense. The ubiquity of this phenomenon is evidenced by the fact that there are representatives for AP interference in all major viral families, covered in this review. The best described examples are interactions of human immunodeficiency virus and human herpesviruses with AP complexes. Several other viruses, like Ebola, Nipah, and SARS-CoV-2, are pointed out as high priority disease-causative agents supporting the need for deeper understanding of virus-AP interplay which can be exploited in the design of novel antiviral therapies.     

Optimization of a Fabric Softener Formulation with an Electrochemical Sensor and Streaming Potential Measurements

An electrochemical, cationic, surfactant-selective sensor based on multiwalled carbon nanotubes (MWCNT) functionalized with a sulfate group and the cetylpyridinium ion (MWCNT–OSO₃⁻CP⁺) as a sensing material was used for optimization of the formulation of a fabric softener. Potentiometric titrations were performed and response measurements were obtained using four cationic surfactants (CS) of technical grade and four CS of analytical grade. The slope closest to Nernstian was obtained for di-(tallow carboxyethyl) hydroxyethyl methylammonium methosulfate (MAS) (59.5 ± 1.1 mV/decade of activity in water and 57.5 ± 1.3 mV/decade of activity in CaCl₂). When using CS as analytes in potentiometric titrations, the best accuracy (99.8%) was obtained when using MAS; therefore, it was chosen as the CS for the fabric softener formulation. Due to the better properties of fabric softeners with silicone in their formulations, four silicones at several concentration levels were used as potential additives. Based on the stability and viscosity of the system, the diquaternary polydimethylsiloxane (DPS) (w = 0.19%) was chosen for the fabric softener formulation. The pH did not significantly influence the potential when in the range of 3–8 or the recovery of potentiometric titrations when in the range of 3–7. The application profile of the CS was assessed through streaming potential measurements of reference fabrics in an electrokinetic analyzer. The obtained electrokinetic parameters indicated on lag in adsorption of model fabric softener (MFS) based on MAS (w = 9%), with the addition of silicone DPS (MFS 3), on cotton and polyester fabrics, but advantage in stability when compared with other MFS investigated.     

LIN28 Family in Testis: Control of Cell Renewal,Maturation, Fertility and Aging

Male reproductive development starts early in the embryogenesis with somatic and germ cell differentiation in the testis. The LIN28 family of RNA-binding proteins promoting pluripotency has two members—LIN28A and LIN28B. Their function in the testis has been investigated but many questions about their exact role based on the expression patterns remain unclear. LIN28 expression is detected in the gonocytes and the migrating, mitotically active germ cells of the fetal testis. Postnatal expression of LIN28 A and B showed differential expression, with LIN28A expressed in the undifferentiated spermatogonia and LIN28B in the elongating spermatids and Leydig cells. LIN28 interferes with many signaling pathways, leading to cell proliferation, and it is involved in important testicular physiological processes, such as cell renewal, maturation, fertility, and aging. In addition, aberrant LIN28 expression is associated with testicular cancer and testicular disorders, such as hypogonadotropic hypogonadism and Klinefelter’s syndrome. This comprehensive review encompasses current knowledge of the function of LIN28 paralogs in testis and other tissues and cells because many studies suggest LIN28AB as a promising target for developing novel therapeutic agents.     

Empirical evaluation of selected best practices in implementation of software process improvement

To be successfully applied in practice, software process improvement (SPI) needs not only identifying what needs to be improved, and which factors will influence its success, but also guidelines on how to implement those improvements and meet the factors. This paper proposes an SPI implementation strategy that has been developed in lines with standard SPI models and frameworks, intended to be suitable for global software development (GSD), and exploiting ideas of incremental deliveries, short iterations with frequent reviews and close collaboration with customers. Quantitative analyses of data from case studies within large GSD show that improvement teams implementing the strategy are more likely to have better progress and achieve better effectiveness in terms of improvement deployment within development teams. The results could be useful to SPI practitioners in making their SPI initiatives more successful.