Evaluating Distributed Inspection through Controlled Experiments

Inspection methods can be classified according to their discipline and flexibility. The discipline concerns the formal aspect of an inspection method, whereas the flexibility is strongly related to the simplicity of organising and conducting a meeting. The majority of the available distributed inspection methods have a high level of discipline and flexibility as they are based on a well-defined process and the discussion among team members is easily organised and conducted. In this study the authors present two controlled experiments to evaluate the effectiveness and the efficacy of a distributed inspection process to discover defects within source code. In particular, the first experiment compares the distributed inspection method proposed to a disciplined but not flexible method (i.e. the Fagan's inspection process). In the second experiment the authors investigate differences between the same distributed inspection method and a flexible but not disciplined method (i.e. the pair inspection method). Data analysis reveals that more flexible methods require less time to inspect a software artefact, while the discipline level does not affect the inspection quality

Gas Sorption and Diffusion in Amorphous and Semicrystalline Nanoporous Poly(2,6-dimethyl-1,4-phenylene)oxide

In this contribution is presented an analysis of mass transport properties of low molecular weight compounds in amorphous PPO and in two semicrystalline PPOs obtained by treating with benzene and carbon tetrachloride the amorphous sample. It is found that semicrystalline samples are endowed with larger gas sorption capacity and diffusivity as compared to the amorphous ones: this behavior has been attributed prevalently to the nanoporous nature of the crystalline phases induced by treatment with solvents. In particular, sorption experiments, carried out at 30 °C with methane, carbon dioxide, propane and propylene, have shown that both semicrystalline PPOs display rather interesting features which make them suitable for use as membrane materials in gas separation processes, in view of the relatively high values of solubility and diffusivity. Moreover, these peculiar sorption and mass transport properties have been found to be virtually unaffected by thermal aging: in fact, sorption experiments conducted on amorphous and semicrystalline PPO after treatment at 65 °C for three months showed that sorption and transport properties of aged samples are the same as for the untreated ones. This is an important feature to ensure the stability of performances in membrane applications

Roller Speed Skating Kinematics and Electromyographic Analysis: A Methodological Approach

Roller speed skating is a discipline similar to hockey and ice skating from a biomechanical point of view, but there are no specific functional protocols for rehabilitation and performance improvement for these athletes. The aim of the study is to create a dedicated functional, kinematic and electromyographic protocol to be used as a tool for future studies on the subject. The protocol was created, starting from a correct and repeatable movement as a case study, on a world speed skating champion, using an inertial sensor positioned at the level of the first sacral vertebra, eight electromyographic probes positioned on one or the other lower limb, and a high-definition camera at 50 Hz. The results show the electromyographic activity of the muscles investigated, the degree of absolute muscle activation and compared to their maximum voluntary isometric contraction (MVIC), the level of co-activation of the agonist/antagonist muscles, and the accelerations of the body on the three axes of space. The results will represent the basis for physiotherapy and specific training use. Future developments will include the analysis of a sample of elite athletes to be able to build a normal range on the parameters investigated, and the possibility of treating in the most appropriate way possible muscle injuries (which mostly occur in the groin in such athletes) once they have occurred, even with oriented MVIC or co-activation oriented exercises

The oligodeoxynucleotide sequences corresponding to never-expressed peptide motifs are mainly located in the non-coding strand

<p>Abstract</p> <p>Background</p> <p>We study the usage of specific peptide platforms in protein composition. Using the pentapeptide as a unit of length, we find that in the universal proteome many pentapeptides are heavily repeated (even thousands of times), whereas some are quite rare, and a small number do not appear at all. To understand the physico-chemical-biological basis underlying peptide usage at the proteomic level, in this study we analyse the energetic costs for the synthesis of rare and never-expressed versus frequent pentapeptides. In addition, we explore residue bulkiness, hydrophobicity, and codon number as factors able to modulate specific peptide frequencies. Then, the possible influence of amino acid composition is investigated in zero- and high-frequency pentapeptide sets by analysing the frequencies of the corresponding inverse-sequence pentapeptides. As a final step, we analyse the pentadecamer oligodeoxynucleotide sequences corresponding to the never-expressed pentapeptides.</p> <p>Results</p> <p>We find that only DNA context-dependent constraints (such as oligodeoxynucleotide sequence location in the minus strand, introns, pseudogenes, frameshifts, etc.) provide a coherent mechanistic platform to explain the occurrence of never-expressed versus frequent pentapeptides in the protein world.</p> <p>Conclusions</p> <p>This study is of importance in cell biology. Indeed, the rarity (or lack of expression) of specific 5-mer peptide modules implies the rarity (or lack of expression) of the corresponding <it>n</it>-mer peptide sequences (with <it>n </it>< 5), so possibly modulating protein compositional trends. Moreover the data might further our understanding of the role exerted by rare pentapeptide modules as critical biological effectors in protein-protein interactions.</p

Inhibitory Effect of Aqueous Extracts from Marine Sponges on the Activity and Expression of Gelatinases A (MMP-2) and B (MMP-9) in Rat Astrocyte Cultures

The aim of this study was to evaluate whether water soluble compounds present in aqueous extracts from seven Mediterranean demosponges exert biological activity towards matrix metalloproteinases (MMPs), which represent important pathogenic factors of human dis- eases. Aqueous extracts were tested on LPS-activated cultured rat astrocytes, and levels and expression of MMP-2 and MMP-9 were assessed by zymography and RT-PCR, re- spectively. Our results demonstrated that the studied extracts contain water soluble com- pounds able to inhibit MMP-2 and MMP-9 activity and expression. We also compared the anti-MMP activities present in aqueous extracts from wild and reared specimens of Tethya aurantium and T. citrina. The results obtained revealed that the reared sponges maintain the production of bioactive compounds with inhibitory effect on MMP-2 and MMP-9 for all the duration of the rearing period. Taken together, our results indicate that the aqueous ex- tracts from the selected Mediterranean demosponges possess a variety of water-soluble bioactive compounds, which are able to inhibit MMPs at different levels. The presence of bi- ological activity in aqueous extracts from reared specimens of T. aurantium and T. citrina strongly encourage sponge aquaculture as a valid option to supply sponge biomass for drug development on a large scale

comparing inspection methods using controlled experiments

Objective: In this paper we present an empirical study that was aimed at comparing three software inspection methods, in terms of needed time, precision, and recall values. The main objective of this study is to provide software engineers with some insight into choosing the inspection method to adopt. Method: We conducted a controlled experiment and a replication. These experiments involved 48 Master students in Computer Science at the University of Salerno. In the experiments, 6 academic researchers were also involved. The students had to discover defects within a software artefact using inspection methods that differ in terms of discipline and flexibility. In particular, we selected a disciplined but not flexible method (the Fagan's process), a disciplined and flexible method (a virtual inspection), and a flexible but not disciplined method (the pair inspection). Results: We observed a significant difference in favour of the Pair Inspection method for the time spent to perform the tasks. The data analysis also revealed a significant difference in favour of the Fagan's inspection process for precision. Finally, the effect of the inspection method on the recall is not significant. Conclusions: The empirical investigation showed that the discipline and flexibility of an inspection method affect both the time needed to identify defects and the precision of the inspection results. In particular, more flexible methods require less time to inspect a software artefact, while more disciplined methods enable the identification of a lower number of false defects

Mathematical models for the diffusion magnetic resonance signal abnormality in patients with prion diseases

AbstractIn clinical practice signal hyperintensity in the cortex and/or in the striatum on magnetic resonance (MR) diffusion-weighted images (DWIs) is a marker of sporadic Creutzfeldt–Jakob Disease (sCJD). MR diagnostic accuracy is greater than 90%, but the biophysical mechanisms underpinning the signal abnormality are unknown. The aim of this prospective study is to combine an advanced DWI protocol with new mathematical models of the microstructural changes occurring in prion disease patients to investigate the cause of MR signal alterations. This underpins the later development of more sensitive and specific image-based biomarkers. DWI data with a wide a range of echo times and diffusion weightings were acquired in 15 patients with suspected diagnosis of prion disease and in 4 healthy age-matched subjects. Clinical diagnosis of sCJD was made in nine patients, genetic CJD in one, rapidly progressive encephalopathy in three, and Gerstmann–Sträussler–Scheinker syndrome in two. Data were analysed with two bi-compartment models that represent different hypotheses about the histopathological alterations responsible for the DWI signal hyperintensity. A ROI-based analysis was performed in 13 grey matter areas located in affected and apparently unaffected regions from patients and healthy subjects. We provide for the first time non-invasive estimate of the restricted compartment radius, designed to reflect vacuole size, which is a key discriminator of sCJD subtypes. The estimated vacuole size in DWI hyperintense cortex was in the range between 3 and 10 µm that is compatible with neuropathology measurements. In DWI hyperintense grey matter of sCJD patients the two bi-compartment models outperform the classic mono-exponential ADC model. Both new models show that T2 relaxation times significantly increase, fast and slow diffusivities reduce, and the fraction of the compartment with slow/restricted diffusion increases compared to unaffected grey matter of patients and healthy subjects. Analysis of the raw DWI signal allows us to suggest the following acquisition parameters for optimized detection of CJD lesions: b = 3000 s/mm2 and TE = 103 ms. In conclusion, these results provide the first in vivo estimate of mean vacuole size, new insight on the mechanisms of DWI signal changes in prionopathies and open the way to designing an optimized acquisition protocol to improve early clinical diagnosis and subtyping of sCJD