Integrated stratigraphy of the Early Miocene lacustrine deposits of Pag Island (SW Croatia): Palaeovegetation and environmental changes in the Dinaride Lake System

An integrated stratigraphic study of a Neogene lacustrine succession on the Pag Island (Croatia), combining quantitative pollen analysis, magnetostratigraphy, cyclostratigraphy, biostratigraphy and gamma-ray measurements, provides new insights into orbitally controlled variations in palaeo-vegetation and depositional patterns in the Dinaride Lake System. The quantitative palynological record shows a cyclical pattern of vegetation changes that closely corresponds to sedimentological patterns. The intervals with a high abundance of thermophilous and xeric indicators, suggesting a warm and dry climate, generally coincide with intervals of frequent lignite deposition and shallow lake facies. This suggests that both records are dominantly controlled by variations in past climatic conditions and lake level. Our data show two large-scale warming and shallowing-upward cycles, which are interpreted to be forced by the ~ 100 kyr eccentricity cycle of the Earth's orbit. Magnetostratigraphic data of the examined section reveal a long (113 m) reversed polarity interval, followed by a 7 m thick interval of normal polarity at the top. The inferred depositional rate of ~ 0.3 mm/yr, combined with biostratigraphic constraints by mollusks, suggests that the most logical correlation of the reversed interval is to chron C5Cr. This indicates that the Pag succession was deposited between 17.1 and 16.7 Ma and that it corresponds to the Burdigalian Stage of the Early Miocene, and the regional Karpatian Stage of the Central Paratethys. The high relative percentage of thermophilous pollen taxa, Engelhardia and Taxodium-type being the most prominent, generally indicates a subtropical humid climate for the SW Croatian part of the Dinaride Lake System. The observed warming trend is possibly related to the onset of the Miocene Climatic Optimum.     

Welcome back New Zealand: regional biogeography and Gondwanan origin of three endemic genera of mite harvestmen (Arachnida, Opiliones, Cyphophthalmi)

Aim Biogeographers have long been intrigued by New Zealand’s biota due to its unique combination of typical ‘continental’ and ‘island’ characteristics. The New Zealand plateau rifted from the former supercontinent Gondwana c. 80 Ma, and has been isolated from other land masses ever since. Therefore, the flora and fauna of New Zealand include lineages that are Gondwanan in origin, but also include a very large number of endemics. In this study, we analyse the evolutionary relationships of three genera of mite harvestmen (Arachnida, Opiliones, Cyphophthalmi) endemic to New Zealand, both to each other and to their temperate Gondwanan relatives found in Australia, Chile, Sri Lanka and South Africa. Location New Zealand (North Island, South Island and Stewart Island). Methods A total of 94 specimens of the family Pettalidae in the suborder Cyphophthalmi were studied, representing 31 species and subspecies belonging to three endemic genera from New Zealand (Aoraki, Neopurcellia and Rakaia) plus six other members of the family from Chile, South Africa, Sri Lanka and Australia. The phylogeny of these taxa was constructed using morphological and molecular data from five nuclear and mitochondrial genes (18S rRNA, 28S rRNA, 16S rRNA, cytochrome c oxidase subunit I and histone H3, totalling c. 5 kb), which were analysed using dynamic as well as static homology under a variety of optimality criteria. Results The results showed that each of the three New Zealand cyphophthalmid genera is monophyletic, and occupies a distinct geographical region within the archipelago, grossly corresponding to palaeogeographical regions. All three genera of New Zealand mite harvestmen fall within the family Pettalidae with a classic temperate Gondwanan distribution, but they do not render any other genera paraphyletic. Main conclusions Our study shows that New Zealand’s three genera of mite harvestmen are unequivocally related to other members of the temperate Gondwanan family Pettalidae. Monophyly of each genus contradicts the idea of recent dispersal to New Zealand. Within New Zealand, striking biogeographical patterns are apparent in this group of short‐range endemics, particularly in the South Island. These patterns are interpreted in the light of New Zealand’s turbulent geological history and present‐day patterns of forest cover.     

A relict in New Caledonia: phylogenetic relationships of the family Troglosironidae (Opiliones: Cyphophthalmi)

The species richness and endemism of New Caledonia are traditionally held to result from the main island's Gondwanan origin and progressive diversification subsequent to extended isolation. Recent studies have challenged this hypothesis, promoting a scenario of recent origins and diversifications of New Caledonian arthropod groups. In the present study, the phylogeny of the endemic harvestman family Troglosironidae (Opiliones: Cyphophthalmi) is investigated using DNA sequence data from two nuclear ribosomal genes (18S rRNA and 28S rRNA) and two mitochondrial genes (the protein-coding cytochrome c oxidase subunit I and the ribosomal 16S rRNA). Phylogenetic analyses support the monophyly of Troglosironidae and a scenario of an ancient (> 200 Ma) origin of the family, with subsequent diversification of extant lineages in the Eocene. These results corroborate the relictual nature of taxa among New Caledonia's biota while being consistent with diversification in accordance with geological events in the Eocene.     

Phylogenetics of scutigeromorph centipedes (Myriapoda: Chilopoda) with implications for species delimitation and historical biogeography of the Australian and New Caledonian faunas

Phylogeny of the centipede order Scutigeromorpha has received recent attention from combined analyses of molecular and morphological data. Denser generic sampling, an additional marker (12S rRNA), and multiple specimens for selected species are used to explore phylogeny, biogeography and taxonomy of this charismatic group of centipedes. Among 55 specimens/27 species analysed for six genes are the first molecular data for the genera Dendrothereua , Pilbarascutigera , and Tachythereua , and previously unsampled species of Scutigerinae from Madagascar. Sampling density is especially increased for Thereuoneminae from Australia and New Caledonia. At the base of Scutigeromorpha, the split of Pselliodidae from Scutigerinidae + Scutigeridae is favoured by the optimal parameter set in combined analyses, but most suboptimal parameter sets instead unite pselliodids and scutigerinids. Dendrothereua is re-established for a Neotropical clade that variably resolves as sister to Tachythereua or separate from Scutigerinae, grouped with Pselliodidae and Scutigerinidae. As traditionally diagnosed, the genera that comprise most of Australian and New Caledonian diversity, Allothereua and Parascutigera , are mutually polyphyletic, though they unite as a well supported clade, sister to or including the Western Australian Pilbarascutigera . The main biogeographical signal within the Allothereua / Parascutigera clade is Western Australia as sister area to eastern Australia/New Caledonia, within which New Caledonian " Parascutigera " has a single origin under optimal parameter sets. Genetic variation within scutigeromorph species is appraised using samples of Scutigera coleoptrata throughout its native distribution plus presumed synanthropic records, and from the Allothereua/Parascutigera clade. Variation between six alleged narrow-range endemic species of Parascutigera in north Queensland is consistent with a single species.     

Domoic acid production by Pseudo-nitzschia australis and Pseudo-nitzschia calliantha isolated from North Chile

The morphology and toxicity of the four ubiquitous species belonging to the genus Pseudo-nitzschia found in mixed blooms of phytoplankton from northern Chilean waters were studied. The phytoplankton samples and cultures obtained were identified by scanning electron microscopy, revealing the presence of Pseudo-nitzschia australis, P. calliantha, P. pseudodelicatissima and P. subfraudulenta. This is the first report of P. calliantha in northern Chile. Toxin analyses using the LC–MS method confirmed the presence of domoic acid in P. australis and P. calliantha. Domoic acid was not detected in cultures of P. subfraudulenta. This study therefore confirms P. australis and P. calliantha as an unequivocal source of domoic acid in Chilean waters. P. australis is probably the most important producer of amnesic shellfish toxin in view of its domoic acid content. However, more research is needed to evaluate the potential for toxin production in P. pseudodelicatissima.     

Biocatalytic properties of Baeyer–Villiger monooxygenases in aqueous–organic media

The biocatalytic properties of three Baeyer–Villiger monooxygenases (phenylacetone monooxygenase, 4-hydroxyacetophenone monooxygenase and ethionamide monooxygenase) in a variety of aqueous–organic media were studied using organic sulfides as substrates. The influence of the nature and the concentration of the solvents, as well as of the substrates, on the activity and enantioselectivity of the enzymes was investigated in detail. Solvents were found to decrease, to a different extent, enzyme activity. High increases of enantioselectivity and also reversal of enantiopreference were observed depending on the enzyme and on the nature of the solvent and the substrate employed.     

Historical Biogeography and Diversification of Truffles in the Tuberaceae and Their Newly Identified Southern Hemisphere Sister Lineage

Truffles have evolved from epigeous (aboveground) ancestors in nearly every major lineage of fleshy fungi. Because accelerated rates of morphological evolution accompany the transition to the truffle form, closely related epigeous ancestors remain unknown for most truffle lineages. This is the case for the quintessential truffle genus Tuber, which includes species with socio-economic importance and esteemed culinary attributes. Ecologically, Tuber spp. form obligate mycorrhizal symbioses with diverse species of plant hosts including pines, oaks, poplars, orchids, and commercially important trees such as hazelnut and pecan. Unfortunately, limited geographic sampling and inconclusive phylogenetic relationships have obscured our understanding of their origin, biogeography, and diversification. To address this problem, we present a global sampling of Tuberaceae based on DNA sequence data from four loci for phylogenetic inference and molecular dating. Our well-resolved Tuberaceae phylogeny shows high levels of regional and continental endemism. We also identify a previously unknown epigeous member of the Tuberaceae – the South American cup-fungus Nothojafnea thaxteri (E.K. Cash) Gamundí. Phylogenetic resolution was further improved through the inclusion of a previously unrecognized Southern hemisphere sister group of the Tuberaceae. This morphologically diverse assemblage of species includes truffle (e.g. Gymnohydnotrya spp.) and non-truffle forms that are endemic to Australia and South America. Southern hemisphere taxa appear to have diverged more recently than the Northern hemisphere lineages. Our analysis of the Tuberaceae suggests that Tuber evolved from an epigeous ancestor. Molecular dating estimates Tuberaceae divergence in the late Jurassic (∼156 million years ago), with subsequent radiations in the Cretaceous and Paleogene. Intra-continental diversification, limited long-distance dispersal, and ecological adaptations help to explain patterns of truffle evolution and biodiversity.     

No Major Differences Found between the Effects of Microwave-Based and Conventional Heat Treatment Methods on Two Different Liquid Foods

Extension of shelf life and preservation of products are both very important for the food industry. However, just as with other processes, speed and higher manufacturing performance are also beneficial. Although microwave heating is utilized in a number of industrial processes, there are many unanswered questions about its effects on foods. Here we analyze whether the effects of microwave heating with continuous flow are equivalent to those of traditional heat transfer methods. In our study, the effects of heating of liquid foods by conventional and continuous flow microwave heating were studied. Among other properties, we compared the stability of the liquid foods between the two heat treatments. Our goal was to determine whether the continuous flow microwave heating and the conventional heating methods have the same effects on the liquid foods, and, therefore, whether microwave heat treatment can effectively replace conventional heat treatments. We have compared the colour, separation phenomena of the samples treated by different methods. For milk, we also monitored the total viable cell count, for orange juice, vitamin C contents in addition to the taste of the product by sensory analysis. The majority of the results indicate that the circulating coil microwave method used here is equivalent to the conventional heating method based on thermal conduction and convection. However, some results in the analysis of the milk samples show clear differences between heat transfer methods. According to our results, the colour parameters (lightness, red-green and blue-yellow values) of the microwave treated samples differed not only from the untreated control, but also from the traditional heat treated samples. The differences are visually undetectable, however, they become evident through analytical measurement with spectrophotometer. This finding suggests that besides thermal effects, microwave-based food treatment can alter product properties in other ways as well.