Modeling Overstock

Two main problems have been emerging in supply chain management: the increasing pressure to reduce working capital and the growing variety of products. Most of the popular indicators have been developed based on a controlled environment. A new indicator is now proposed, based on the uncertainty of the demand, the flexibility of the supply chains, the evolution of the products lifecycle and the fulfillment of a required service level. The model to support the indicator will be developed within the real options approach.overstock, stock management, real options

Differential temporal beta‐diversity patterns of native and non‐native arthropod species in a fragmented native forest landscape

An important factor that hinders the management of non‐native species is a general lack of information regarding the biogeography of non‐natives, and, in particular, their rates of turnover. Here, we address this research gap by analysing differences in temporal beta‐diversity (using both pairwise and multiple‐time dissimilarity metrics) between native and non‐native species, using a novel time‐series dataset of arthropods sampled in native forest fragments in the Azores. We use a null model approach to determine whether temporal beta‐diversity was due to deterministic processes or stochastic colonisation and extinction events, and linear modelling selection to assess the factors driving variation in temporal beta‐diversity between plots. In accordance with our predictions, we found that the temporal beta‐diversity was much greater for non‐native species than for native species, and the null model analyses indicated that the turnover of non‐native species was due to stochastic events. No predictor variables were found to explain the turnover of native or non‐native species. We attribute the greater turnover of non‐native species to source‐sink processes and the close proximity of anthropogenic habitats to the fragmented native forest plots sampled in our study. Thus, our findings point to ways in which the study of turnover can be adapted for future applications in habitat island systems. The implications of this for biodiversity conservation and management are significant. The high rate of stochastic turnover of non‐native species indicates that attempts to simply reduce the populations of non‐native species in situ within native habitats may not be successful. A more efficient management strategy would be to interrupt source‐sink dynamics by improving the harsh boundaries between native and adjacent anthropogenic habitats.Portuguese FCT‐NETBIOME – ISLANDBIODIV grant 0003/2011.info:eu-repo/semantics/publishedVersio

Consistency and identifiability of the polymorphism-aware phylogenetic models

Funding: Vienna Science and Technology Fund (WWTF) [MA16-061].Polymorphism-aware phylogenetic models (PoMo) constitute an alternative approach for species tree estimation from genome-wide data. PoMo builds on the standard substitution models of DNA evolution but expands the classic alphabet of the four nucleotide bases to include polymorphic states. By doing so, PoMo accounts for ancestral and current intra-population variation, while also accommodating population-level processes ruling the substitution process (e.g. genetic drift, mutations, allelic selection). PoMo has shown to be a valuable tool in several phylogenetic applications but a proof of statistical consistency (and identifiability, a necessary condition for consistency) is lacking. Here, we prove that PoMo is identifiable and, using this result, we further show that the maximum a posteriori (MAP) tree estimator of PoMo is a consistent estimator of the species tree. We complement our theoretical results with a simulated data set mimicking the diversity observed in natural populations exhibiting incomplete lineage sorting. We implemented PoMo in a Bayesian framework and show that the MAP tree easily recovers the true tree for typical numbers of sites that are sampled in genome-wide analyses.Publisher PDFPeer reviewe

The Role of Gene Duplication and Unconstrained Selective Pressures in the Melanopsin Gene Family Evolution and Vertebrate Circadian Rhythm Regulation

Melanopsin is a photosensitive cell protein involved in regulating circadian rhythms and other non-visual responses to light. The melanopsin gene family is represented by two paralogs,OPN4x and OPN4m, which originated through gene duplication early in the emergence of vertebrates. Here we studied the melanopsin gene family using an integrated gene/protein evolutionary approach, which revealed that the rhabdomeric urbilaterian ancestor had the same amino acid patterns (DRY motif and the Y and E conterions) as extant vertebrate species, suggesting that the mechanism for light detection and regulation is similar to rhabdomeric rhodopsins. Both OPN4m and OPN4x paralogs are found in vertebrate genomic paralogons, suggesting that they diverged following this duplication event about 600 million years ago, when the complex eye emerged in the vertebrate ancestor. Melanopsins generally evolved under negative selection (ω = 0.171) with some minor episodes of positive selection (proportion of sites = 25%) and functional divergence (θI = 0.349 and θII = 0.126). The OPN4m and OPN4x melanopsin paralogs show evidence of spectral divergence at sites likely involved in melanopsin light absorbance (200F, 273S and 276A). Also, following the teleost lineage-specific whole genome duplication (3R) that prompted the teleost fish radiation, type I divergence (θI = 0.181) and positive selection (affecting 11% of sites) contributed to amino acid variability that we related with the photo-activation stability of melanopsin. The melanopsin intracellular regions had unexpectedly high variability in their coupling specificity of G-proteins and we propose that Gq/11 and Gi/o are the two G-proteins most-likely to mediate the melanopsin phototransduction pathway. The selection signatures were mainly observed on retinal-related sites and the third and second intracellular loops, demonstrating the physiological plasticity of the melanopsin protein group. Our results provide new insights on the phototransduction process and additional tools for disentangling and understanding the links between melanopsin gene evolution and the specializations observed in vertebrates, especially in teleost fish

Hidryta atlantica

JUSTIFICATION: Hidryta azorica is a potentially endemic species of the Azores (Portugal) known only from the holotype and for which there is no precise indication of island of occurrence, while it has been suggested that Hidryta atlantica might be a melanic form of H. sordida, a widespread European species. It possibly has a very small Extent of Occurrence (EOO = 4 km²) and Area of Occupancy (AOO = 4 km²). Based upon the unknown distribution and ecology, this species is assessed as Data Deficient (DD).info:eu-repo/semantics/publishedVersio

Kowarzia storai

JUSTIFICATION: Kowarzia storai is an endemic species of the Azores (Portugal), being present (at least historically) on Flores island. From the historical data, this species would have a very small Extent of Occurrence (24 km²) and Area of Occupancy (24 km²), and it is possible that this species has declined in the past as a result of human activity. The present situation of this species needs to be further assessed and further research is needed into its population, distribution, threats, ecology and life history. Conservation of native wet and boggy areas and natural streams and other water bodies could potentially aid this species conservation. Based upon the lack of recent in data regarding this species population, distribution, threats and ecology, this species is assessed as Data Deficient (DD).info:eu-repo/semantics/publishedVersio

Euphthiracarus excultus

JUSTIFICATION: Euphthiracarus excultus is an endemic species of the Azores (Portugal), described from one disturbed location on Sta. Maria island. From the species' description, it would have a very small Extent of Occurrence (8 km² ) and Area of Occupancy (8 km² ), which are likely underestimates, as this species probably has a wider distribution through the soil component of the island. It can be assumed that this species is affected by human activities and invasive plant species which alter the natural structure and composition of the soil. Future climatic changes and increased risk of droughts will also affect this species. The present situation of this species needs to be further assessed and further research is needed into its population, distribution, threats, ecology and life history; but conservation of natural habitats and invasive species control could potentially aid this species conservation. Based upon the incomplete knowledge regarding this species population, distribution, threats and ecology, this species is assessed as Data Deficient (DD).info:eu-repo/semantics/publishedVersio

Isotope separation with the RICH detector of the AMS Experiment

The Alpha Magnetic Spectrometer (AMS), to be installed on the International Space Station (ISS) in 2008, is a cosmic ray detector with several subsystems, one of which is a proximity focusing Ring Imaging Cherenkov (RICH) detector. This detector will be equipped with a dual radiator (aerogel+NaF), a lateral conical mirror and a detection plane made of 680 photomultipliers and light guides, enabling precise measurements of particle electric charge and velocity. Combining velocity measurements with data on particle rigidity from the AMS Tracker it is possible to obtain a measurement for particle mass, allowing the separation of isotopes. A Monte Carlo simulation of the RICH detector, based on realistic properties measured at ion beam tests, was performed to evaluate isotope separation capabilities. Results for three elements -- H (Z=1), He (Z=2) and Be (Z=4) -- are presented.Comment: 5 pages. Contribution to the Fifth International Workshop on New Worlds in Astroparticle Physics (Faro 2005). Presenter: Rui Pereir

Portuguese silver from the 15th to the 17th century, the 11 dinheiros silver coins

High silver surface contents of high fineness silver coins have been considered in some cases as deriving from very pure silver alloys, being reliable for original bulk composition. Until now, the extent in which surface silver enrichment influences surface analytical results in coins alloys with finenesses greater than the silver content indexed to the maximum value of copper solid solubility in silver (91.2 wt.%) have been disregarded. This investigation, focused on microstructural and compositional characterization of Portuguese 11 dinheiros silver coins, has revealed important surface silver enrichments in high silver fineness coins. In these silver alloys, coin manufacturing process induces a subsurface microstructurally modified layer resulting from intergranular dry and wet corrosion in annealing operations, primarily related to preferential leaching of Cu-rich phase in subsurface depth. This subsurface layer originates a silver overestimation by PIXE and EDXRF analysis, 4 to 7% higher than the bulk of the coins, with unknown elemental compositional gradient and depth that can extend up to to about 70 μm. This study shows, through the combination of different analytical methods, EDXRF, PIXE, SEM-EDS and LA-ICP-MS, that important metallurgical information resulting from the minting process may be missed, when relying only on the judgment of high silver alloys surface analysis. Albeit the existing minor/trace elements compositional gradients between coins surface and bulk, surface contents correlations discriminate distinct silver sources processed during the 15th to 17th centuries in Portugal, from different historical periods and mints, Lisbon and Porto. Gold/bismuth ratios related to the processed silver initial composition and lead/bismuth ratios related to the silver metallurgical processes, are important discriminators of these high silver alloys. Mercury appears also to be an important element for the discrimination of silver alloys sources. Portuguese minting depended and relied on different silver sources during the 15th to 17th centuries. European silver with high Au and Hg, and low Pb and Bi contents, supplied the oldest chronologies of Dom Afonso V and Dom João II in the 15th century, being replaced at the dawn of the 16th century by a new precious metal entering the Portuguese capital, with low Au and high Bi contents, probably derived from argentiferous copper ore sources processing. In the 2nd and 3rd quarters of the 16th century, minor/trace elements contents of Lisbon and Porto mints evolve towards the compositional homogenization observed in Dom Sebastião I period, probably due to major recycling operations of the earlier currency realized in each kingdom. Philippine chronologies reveal the presence of the new discovered Potosí American silver, introduced in Portugal by Dom Filipe I (Felipe II of Spain), distinguishable from the European silver in use until 1578 in the Portuguese territory, by Au contents < 100 ppm and very low Bi contents. Potosí silver is identified for the first time through a superficial analytical method, such as PIXE, rather than by NAA multielement global analysis

Hermannia woasi

JUSTIFICATION: Hermannia woasi is an endemic species of the Azores (Portugal), described from one site on Flores island. From the species description, it has a very small Extent of Occurrence (8 km²) and Area of Occupancy (8 km²), which are likely underestimates, as this species probably has a wider distribution through the soil component of the island. It can be assumed that this species is affected by human activities and invasive plant species that alter the natural structure and composition of the soil; and future climatic changes and increased risk of droughts will also affect this species. The present situation of this species needs to be further assessed and further research is needed into its population, distribution, threats, ecology and life history; while conservation of natural habitats and invasive species control could potentially aid this species conservation. Based upon the incomplete knowledge regarding this species population, distribution, threats and ecology, this species is assessed as Data Deficient (DD).info:eu-repo/semantics/publishedVersio