An Exploratory Study of Field Failures

Field failures, that is, failures caused by faults that escape the testing phase leading to failures in the field, are unavoidable. Improving verification and validation activities before deployment can identify and timely remove many but not all faults, and users may still experience a number of annoying problems while using their software systems. This paper investigates the nature of field failures, to understand to what extent further improving in-house verification and validation activities can reduce the number of failures in the field, and frames the need of new approaches that operate in the field. We report the results of the analysis of the bug reports of five applications belonging to three different ecosystems, propose a taxonomy of field failures, and discuss the reasons why failures belonging to the identified classes cannot be detected at design time but shall be addressed at runtime. We observe that many faults (70%) are intrinsically hard to detect at design-time

The origins and spread of domestic horses from the Western Eurasian steppes

This is the final version. Available on open access from Nature Research via the DOI in this recordData availability: All collapsed and paired-end sequence data for samples sequenced in this study are available in compressed fastq format through the European Nucleotide Archive under accession number PRJEB44430, together with rescaled and trimmed bam sequence alignments against both the nuclear and mitochondrial horse reference genomes. Previously published ancient data used in this study are available under accession numbers PRJEB7537, PRJEB10098, PRJEB10854, PRJEB22390 and PRJEB31613, and detailed in Supplementary Table 1. The genomes of ten modern horses, publicly available, were also accessed as indicated in their corresponding original publications57,61,85-87.NOTE: see the published version available via the DOI in this record for the full list of authorsDomestication of horses fundamentally transformed long-range mobility and warfare. However, modern domesticated breeds do not descend from the earliest domestic horse lineage associated with archaeological evidence of bridling, milking and corralling at Botai, Central Asia around 3500 BC. Other longstanding candidate regions for horse domestication, such as Iberia and Anatolia, have also recently been challenged. Thus, the genetic, geographic and temporal origins of modern domestic horses have remained unknown. Here we pinpoint the Western Eurasian steppes, especially the lower Volga-Don region, as the homeland of modern domestic horses. Furthermore, we map the population changes accompanying domestication from 273 ancient horse genomes. This reveals that modern domestic horses ultimately replaced almost all other local populations as they expanded rapidly across Eurasia from about 2000 BC, synchronously with equestrian material culture, including Sintashta spoke-wheeled chariots. We find that equestrianism involved strong selection for critical locomotor and behavioural adaptations at the GSDMC and ZFPM1 genes. Our results reject the commonly held association between horseback riding and the massive expansion of Yamnaya steppe pastoralists into Europe around 3000 BC driving the spread of Indo-European languages. This contrasts with the scenario in Asia where Indo-Iranian languages, chariots and horses spread together, following the early second millennium BC Sintashta culture

Sulla deposizione di Gallus gallus (Linnaeus, 1758) nella Tomba 4 UniMi della necropoli etrusco/romana di "Le Morre" di Tarquinia (Viterbo)

ItOggetto del presente studio è l'analisi preliminare della deposizione di un giovane individuo di gallo domestico in un contesto funerario rinvenuto eccezionalmente intatto. La presenza di questa specie in contesti funerari è confermata da diversi ritrovamenti, nei quali, come in questo caso, l'animale potrebbe essere stato deposto come offerta di cibo per il defunto. Le indagini dell'Università degli Studi di Milano sul Pianoro della Civita di Tarquinia hanno messo in luce nella necropoli delle Morre, situata sul costone settentrionale del pianoro stesso, una serie di tombe contenenti alcuni resti faunistici. Fra queste, una tomba a camera inviolata, sebbene decisamente disturbata, di ridotte dimensioni, databile entro la metà del III sec. a.C., ha restituito la deposizione di una giovane donna. Nella tomba, oltre ad un esiguo corredo, è stato deposto un giovane gallo domestico. Le ossa dell'animale, rinvenute frammiste a quelle della donna, portano a ritenere che il gallo sia stato deposto a contatto o addirittura sopra il corpo dell'inumata.EnThis study focuses on the zooarchaeological analysis of chicken remains collected in a Roman funerary context. The presence of this animal in several funerary contexts, leads to the hypothesis that the animal has been offered as food for the dead. The archaeological team of the University of Milan excavated a number of tombs in the necropolis of 'Le Morre', on the northern part of La Civita (Tarquinia). One tomb of a young woman, dated to the first half of the 3rd century BC, displays grave goods and the bones of a young chicken. The bird remains have been collected from the chest of the woman mixed together with her own bones. Likely, the chicken was placed next to or on the corpse when it was buried

Optical characterization of thiolate self-assembled monolayers on Au(111)

We have investigated the optical response of thiolate self-assembled monolayers (SAMs) deposited from the liquid phase on well characterized, (111)-textured gold films based on the use of in situ and ex situ optical spectroscopic ellipsometry. We considered SAMs formed by several molecules with thiol functionality, focusing on the octadecanethiol (C18) SAM model system. We were able to show the tiny spectroscopic variations induced by the monolayer thick films with great reproducibility and high signal-to-noise ratio. We identified spectral features related to the alkyl chain and to the S-Au interface, providing a reliable spectral \u201cfingerprint\u201d of the formation of densely packed thiolate layers. By comparing data with simulations based on several effective models developed within the framework of Fresnel approach, we identified the main optical features related to the thiolate interface and in particular an absorption band whose spectral weight increases regularly from 500 nm toward the IR limit. We also obtained reliable estimations of the SAM thickness. The interface absorption properties have been tentatively assigned to a modification of the nearly free electron behavior, related to nanoscale morphological modifications following the formation of Au-thiolate moieties

Electronic and Geometric Characterization of the L-Cysteine Paired-Row Phase on Au(110)

8We have studied the vapor-phase deposition of L-cysteine on the Au(110) surface by means of synchrotron-based techniques. Relying on a comparison with previous X-ray photoemission analysis, we have assigned the fine structure of the C K-shell X-ray absorption spectra to the nonequivalent carbon bonds within the molecule. In particular, the C1s ->sigma* transition, where the sigma* state is mainly localized on the C-S bond, is shifted well below the ionization treshold, at similar to -5 eV from the characteristic pi* transition line related to carboxylic group. From the polarization dependence of the absorption spectra in the monolayer coverage range, the molecules are found to lay flat on the surface with both the C-S bond and the carboxylic group almost parallel to the surface. We performed in situ complementary surface X-ray diffraction, SXRD, measurements to probe the rearrangement of the Au atoms beneath the L-cysteine molecules. Since the early stage of deposition, L-cysteine domains are formed which display an intermediate fourfold symmetry along [001]. The self-assembly of molecules into paired rows, extending along the [10] direction, is fully compatible with our observations, as has been reported for the case of D-cysteine molecules grown on Au(110).nonenoneALBANO COSSARO; SILVANA TERRENI; ORNELLA CAVALLERI; MIRKO PRATO; DEAN CVETKO; A. MORGANTE; LUCA FLOREANO; AND MAURIZIO CANEPAAlbano, Cossaro; Silvana, Terreni; Ornella, Cavalleri; Mirko, Prato; Dean, Cvetko; Morgante, Alberto; Luca, Floreano; AND MAURIZIO, Canep

Optical properties of disulfide-functionalized diacetylene self-assembled monolayers on gold: a spectroscopic ellipsometry study

Spectroscopic ellipsometry (SE) has been applied to study the optical properties of thiolate polydiacetylene (PDA) self-assembled monolayers (SAMs) deposited on low-roughness polycrystalline gold. A systematic investigation of methyl-terminated diacetylene (dihexacosa-7,9-diyn disulfide, DS9) SAMs is presented. The results have been compared with experiments on carbazolyl-derivatized diacetylene (14-(9H-9-carbazolyl)tetradeca-10,12-diyn-1-yl-disulfide, CDS9) SAMs and with findings recently obtained on SAMs of alkanethiols. The SE measurements have been complemented with X-ray photoelectron spectroscopy and atomic force microscopy data. The difference between SE spectra measured after and before the monolayer assembly (\uf0b6\uf059= \uf059SAM-\uf059Au and \uf0b6\uf044= \uf044SAM-\uf044Au) showed specific absorptions of the adsorbed molecules, including narrow features in the 500-700 nm wavelength range which have been interpreted as markers of the SAM polymerization state. To our knowledge, these results represent the first unambiguous optical detection of polymer-induced absorptions in the case of diacetylene SAMs. Polymerization mainly occurred in the so-called red phase (absorption peak around 550 nm) on very flat surface regions obtained by flame-annealing the sample. The polymeric phase was stable against moderate UV irradiance. The detection of the blue phase was questionable as specific absorptions (around 640 nm) overlap with an absorption band related to the formation of the S-Au interface