Progress in Classical and Quantum Variational Principles

We review the development and practical uses of a generalized Maupertuis least action principle in classical mechanics, in which the action is varied under the constraint of fixed mean energy for the trial trajectory. The original Maupertuis (Euler-Lagrange) principle constrains the energy at every point along the trajectory. The generalized Maupertuis principle is equivalent to Hamilton's principle. Reciprocal principles are also derived for both the generalized Maupertuis and the Hamilton principles. The Reciprocal Maupertuis Principle is the classical limit of Schr\"{o}dinger's variational principle of wave mechanics, and is also very useful to solve practical problems in both classical and semiclassical mechanics, in complete analogy with the quantum Rayleigh-Ritz method. Classical, semiclassical and quantum variational calculations are carried out for a number of systems, and the results are compared. Pedagogical as well as research problems are used as examples, which include nonconservative as well as relativistic systems

Colour assessment outcomes – a new approach to grading the severity of color vision loss

INTRODUCTION: Recent studies have shown that a significant percentage of subjects with anomalous, congenital trichromacy can perform the suprathreshold, colour-related tasks encountered in many occupations with the same accuracy as normal trichromats. In the absence of detailed, occupation-specific studies, an alternative approach is to make use of new findings and the statistical outcomes of past practices that have been considered safe to produce graded, justifiable categories of colour vision that can be enforced. METHODS: We analyzed traditional color assessment outcomes and measured severity of colour vision loss using the CAD test in 1363 subjects (336 normals, 705 deutan, 319 protan and 3 tritan). The severity of colour vision loss was measured in each subject and statistical, pass / fail outcomes established for each of the most commonly used, conventional colour assessment tests and protocols. RESULTS: The correlation between the number of Ishihara (IH) test plates subjects fail and the severity of RG colour vision loss was very poor. The 38 plates IH test has high sensitivity when no errors are allowed (i.e., only 0.71% deutans and 0.63% protans pass). Protocols based on zero errors are uncommon since 18.15% of normal trichromats fail. The most common protocols employ either the 24 or the 14 plates editions with two or less errors. These protocols pass almost all normal trichromats, but the deutans and some protans that also pass (when two or less errors are allowed) can be severely deficient. This is simply because the most challenging plates have not been included in the 24 and 14 plates editions. As a result, normals no longer fail, but the deutans and protans that pass have more severe loss of colour vision since they fail less challenging plates. The severity of colour vision loss was measured in each subject and statistical, pass / fail outcomes established for each of the most commonly used, conventional colour assessment tests and protocols. DISCUSSION: Historical evidence and new findings that relate severity of loss to the effective use of colour signals in a number of tasks provide the basis for a new colour grading system based on six categories. A single colour assessment test is needed to establish the applicant’s Colour Vision category which can range from ‘supernormal’ (CV0), for the most stringent, colour-demanding tasks, to ‘severe colour deficiency’, when red / green colour vision is either absent or extremely weak (CV5)

First finds of Prunus domestica L. in Italy from the Phoenician and Punic periods (6th-2nd centuries BC)

Abstract During the archaeological excavations in the Phoenician and Punic settlement of Santa Giusta (Oristano, Sardinia, Italy), dating back to the 6th–2nd centuries bc, several Prunus fruitstones (endocarps) inside amphorae were recovered. The exceptional state of preservation of the waterlogged remains allowed morphometric measurements to be done by image analysis and statistical comparisons made with modern cultivated and wild Prunus samples collected in Sardinia. Digital images of modern and archaeological Prunus fruitstones were acquired with a flatbed scanner and analysed by applying image analysis techniques to measure 26 morphometric features. By applying stepwise linear discriminant analysis, a morphometric comparison was made between the archaeological fruitstones of Prunus and the modern ones collected in Sardinia. These analyses allowed identification of 53 archaeological fruitstones as P. spinosa and 11 as P. domestica. Moreover, the archaeological samples of P. spinosa showed morphometric similarities in 92.5% of the cases with the modern P. spinosa samples currently growing near the Phoenician and Punic site. Likewise, the archaeological fruitstones identified as P. domestica showed similarities with the modern variety of P. domestica called Sanguigna di Bosa which is currently cultivated near the village of Bosa. Currently, these findings represent the first evidence of P. domestica in Italy during the Phoenician and Punic periods. Keywords Archaeobotany · Image analysis · Morphometric features · Prunus · Sardini

Searching for the origins of bere barley: a geometric morphometric approach to cereal landrace recognition in archaeology

Bere is a landrace of barley, adapted to the marginal conditions of northern Scotland, especially those of the Northern and Western Isles. The history of bere on these islands is long and, in an era of diminishing landrace cultivation, bere now represents one of the oldest cereal landraces in Europe still grown commercially. The longevity of bere raises the possibility of using grain characteristics of present-day specimens to identify bere in the archaeological record. Geometric modern morphometric (GMM) analysis of grains from bere and other barley landraces is conducted to determine whether landraces can be differentiated on grain morphology. Results indicate that there are morphological differences between bere and other British and Scandinavian landraces, and between bere from Orkney and the Western Isles, both of which are apparent in genetic analysis. This finding paves the way for the identification of bere archaeologically, helping to establish its status as living heritage and securing its commercial future. More broadly, this work indicates the potential of grain GMM for the recognition of cereal landraces, permitting the ancestry and exchange of landraces to be traced in the archaeological record

On the origin of the invasive olives (Olea europaea L., Oleaceae).

The olive tree (Olea europaea) has successfully invaded several regions in Australia and Pacific islands. Two olive subspecies (subspp. europaea and cuspidata) were first introduced in these areas during the nineteenth century. In the present study, we determine the origin of invasive olives and investigate the importance of historical effects on the genetic diversity of populations. Four invasive populations from Australia and Hawaii were characterized using eight nuclear DNA microsatellites, plastid DNA markers as well as ITS-1 sequences. Based on these data, their genetic similarity with native populations was investigated, and it was determined that East Australian and Hawaiian populations (subsp. cuspidata) have originated from southern Africa while South Australian populations (subsp. europaea) have mostly derived from western or central Mediterranean cultivars. Invasive populations of subsp. cuspidata showed significant loss of genetic diversity in comparison to a putative source population, and a recent bottleneck was evidenced in Hawaii. Conversely, invasive populations of subsp. europaea did not display significant loss of genetic diversity in comparison to a native Mediterranean population. Different histories of invasion were inferred for these two taxa with multiple cultivars introduced restoring gene diversity for europaea and a single successful founder event and sequential introductions to East Australia and then Hawaii for cuspidata. Furthermore, one hybrid (cuspidata x europaea) was identified in East Australia. The importance of hybridizations in the future evolution of the olive invasiveness remains to be investigated