The genus Mahonia in the Miocene of Turkey: Taxonomy and biogeographic implications

The genus Mahonia has a disjunct modern distribution with the New World Group Occidentales in northwestern North America and Central America and the mostly Old World Group Orientales in Central and Southeast Asia. Group Orientales has one species in North America. Morphologically, the two groups can be distinguished by two main patterns of leaf venation. Leaflets in the Group Orientales have a palmate-festooned brochidodromous venation and those of Group Occidentales usually have a pinnate-brochidodromous to (semi)craspedodromous venation, with some intermediate forms. In North America both Orientales and Occidentales can be traced from Eocene to Miocene strata. No unequivocal records of Mahonia are known from East Asia. A few Oligocene to Pleistocene fossils from Europe can be assigned to Group Orientales and to the section Horridae Fedde of Group Occidentales. Here we report two new species of Mahonia from the Miocene of Turkey, which clearly fall within the morphological range of the Group Orientales. One species, also found in the Oligocene-Miocene of western North America, is quite similar to Himalayan and East and Southeast Asian modern species. The other resembles the single modern North American member of Group Orientales. The high diversity of Mahonia in Europe and Asia Minor from the Oligocene onwards includes members of at least four lineages. The close relationships of these fossils with contemporary North American species suggest that the genus had reached western Eurasia from North America via the North Atlantic during or prior to the Oligocene. Colonization of Central and East Asia may have occurred from western Eurasia or North America, or from both directions. (C) 2012 Elsevier B.V. All rights reserved

The effect of temperature and precipitation on the intra-annual radial growth of Fagus orientalis Lipsky in Artvin, Turkey

In this paper, we present the longest tree-ring chronology of oriental beech from Artvin, identify the most important climate factors affecting radial growth, and compare our results with the oriental beech chronology from Belgrad Forest. Stem disks were taken from 10 living oriental beech trees, and earlywood and latewood bands were measured separately in addition to ring width. The longest (442-year-long) chronology of earlywood, latewood, and total ring width for oriental beech were built from Artvin, Turkey. All chronologies (earlywood, latewood, and total ring width) were found to be highly sensitive to climate with mean sensitivity values of 0.3034, 0.286, and 0.294, respectively. Pearson correlation coefficients were used to identify relationships between tree radial growth and climate. The results showed that the most distinctive effect of temperature on tree-ring growth occurred with maximum temperature. High mean and minimum temperatures in the period of March to July (especially in May) resulted in growth early in the growing season and wide earlywood, latewood, and total ring formation. Different from Belgrad Forest chronology, precipitation was a limiting factor on tree growth, but only in June. High temperatures had a positive effect during the period of March to July and did not cause a drought problem

Using tree-ring signals and numerical model to identify the snow avalanche tracks in Kastamonu, Turkey

Many parts of our planet are exposed to natural disasters such as snow avalanches, floods and earthquakes. Detailed knowledge on these natural disasters is crucial for human safety. On December 25-26, 1992, two avalanches occurred at KayaarkasA +/--Kastamonu in northern Turkey. The first avalanche took place at night of 25-26 December and caused no damage. The second avalanche took place at morning of 26 December, killed four people and did damage to properties. The purpose of the present study is to determine the effects of the snow avalanches on tree rings and to investigate the boundaries and velocities of the avalanches using a numerical simulation model and the tree-ring data. Increment cores from 71 trees in the avalanche-impacted area and the control site were sampled to obtain individual standard chronologies. In the analyses, trees were grouped as (1) heavily damaged by the avalanche, showing a decrease in tree-ring widths since the event, (2) trees heavily damaged by the avalanche, showing an increase in tree-ring widths a couple of years later the event and (3) trees that were not damaged by the avalanche. In this study, one of the most important results is the precise determination of the temporal and spatial patterns of the undocumented avalanche (the first avalanche) event. Avalanches were numerically simulated using dynamical avalanche simulation software ELBA+. Comparison of the simulation model with tree-ring analysis revealed valuable results about the boundaries of the zone of influence of the avalanches

SMILAX (SMILACACEAE) FROM THE MIOCENE OF WESTERN EURASIA WITH CARIBBEAN BIOGEOGRAPHIC AFFINITIES

Premise of the study: Recent molecular studies provide a phylogenetic framework and some dated nodes for the monocot genus Smilax. The Caribbean Havanensis group of Smilax is part of a well-supported "New World clade" with a few disjunct taxa in the Old World. Although the fossil record of the genus is rich, it has been difficult to assign fossil taxa to extant groups based on their preserved morphological characters

Tree-ring reconstructed May-June precipitation in the Caucasus since 1752 CE

The Caucasus region experiences recurrent droughts that affect natural vegetation and the agriculture-based economies of several countries. Because meteorological records are in general scarce and of short timespan, little is known about the magnitude and frequency of past climate variability. Despite the recent increase of climate reconstructions for parts of Eurasia, no study has focused on past hydroclimate variability in the Caucasus. Here, we use a multispecies network of tree-ring width chronologies from the Lesser Caucasus to develop the first precipitation reconstruction for the region back to 1752 CE. Despite the high annual precipitation in the region, our reconstruction accounted for 51.2 % of the variability in May-June precipitation from 1930 to 2001. In comparison with reconstructions in the eastern Mediterranean, our new reconstruction revealed important and distinct drought periods and pluvials. Previous winter North Atlantic Oscillation (NAO), and spring East Atlantic/Western Russia (EA/WR) and North Sea Caspian patterns are likely key drivers of May-June precipitation in the Caucasus and Anatolia. NAO appeared to negatively affect rainfall low-frequency variability while effects of EA/WR were more apparent at the interannual timescales. We also show a potential positive effect of Black Sea surface temperatures on May-June precipitation. In the Caucasus, May-June represents the period of major water supply in semi-arid areas and the period with the highest potential of water scarcity in mesic areas. It is also a period of potential catastrophic flood events. Thus, changes to the precipitation regime during this season will be critical to both human and natural systems of the Caucasus region

Special-Study Modules in a Problem-Based Learning Medical Curriculum AN INNOVATIVE LABORATORY RESEARCH PRACTICE SUPPPORTING INTRODUCTION TO RESEARCH METHODOLOGY IN THE UNDERGRADUATE CURRICULUM

We describe the organization of wet-lab special-study modules (SSMs) in the Central Research Laboratory of Dokuz Eylul Medical School, Izmir, Turkey with the aim of discussing the scientific, laboratory, and pedagogical aspects of this educational activity. A general introduction to the planning and functioning of these SSMs is given, along with specific examples. The wet-lab SSMs incorporate several innovative pedagogies: problem-based learning, research-based learning, practical laboratory education, team-based learning, and project-based learning. Oral and written evaluations show that the students find this activity rewarding. The wet-lab SSM model applied in the Research-Lab of Dokuz Eylul School of Medicine represents a format which is effective in training the students in research methodology, practical laboratory work, and independent learning

Landscape heterogeneity in the Yatagan Basin (southwestern Turkey) during the middle Miocene inferred from plant macrofossils

Plant macrofossils from the lignite mines of Eskihisar, Tinaz, and Salihpasalar (Yatagan Basin, southwestern Anatolia) were investigated. The fossils were collected from marls overlying the exploited lignite seams and represent three subbasins within the main Yatagan Basin. The age of the Eskihisar lignite seam is well constrained by vertebrate fossils (MN 6, middle Miocene). Further, lithological and palynological correlation suggests that the lignite seams and overlying marls in the three lignite mines were formed at the same time. Three distinct zonal vegetation types are reflected in the local plant assemblages: (i) In Eskihisar, Fagus and evergreen Quercus mediterranea-Q. sosnowskyi communities formed important parts of the zonal vegetation along with the deciduous Quercus kubinyii; (ii) in Tinaz, Quercus sosnowskyi-Q. mediterranea-Q. drymeja communities occurred, while Fagus is rarely encountered in the macrofossil record. (iii) In Salihpasalar, Quercus mediterranea and Q. drymeja are the most abundant elements, while Fagus and Q. sosnowskyi are absent or nearly so. This demonstrates that local environmental conditions within a geographically restricted region varied and probably were controlled by slope aspects, edaphic conditions, and river drainage. Overall, the zonal vegetation is characterized by a high diversity of evergreen and deciduous oaks belonging to Quercus subgen. Cerris sect. Ilex and sect. Cerris and the local dominance of Fagus. The riparian vegetation was dominated by Populus, Salix and Acer, whereas Alnus and taxodiaceous Cupressaceae and ferns were very rare or absent. The mass occurrence of Quercus sosnowskyi in the Yatagan Basin floras is biogeographically interesting, as this distinct sclerophyllous oak has previously been known to occur only in late Miocene sediments of northern Greece and Abkhasia (Georgia)

Evaluation of serum neopterin levels and its relationship with adipokines in pediatric obesity-related nonalcoholic fatty liver disease and healthy adolescents

Aim: Nonalcoholic fatty liver disease (NAFLD) is associated with inflammation and increased risk of atherosclerosis. Neopterin is regarded as a biochemical marker of cell-mediated immunity, which is secreted by monocytes and macrophages, mainly in response to interferon-gamma. The aim of the present study was to investigate the serum neopterin levels in obese adolescents and compare the neopterin levels in patients with and without NAFLD and also with healthy controls. The second aim of the study was to research the possible relationship between neopterin levels and adipokines (leptin, adiponectin, resistin, and ghrelin)

Taxonomy and palaeoecology of two widespread western Eurasian Neogene sclerophyllous oak species: Quercus drymeja Unger and Q-mediterranea Unger

Sclerophyllous oaks (genus Quercus) play important roles in Neogene ecosystems of south-western Eurasia. Modern analogues ('nearest living relatives') for these oaks have been sought among five of six infrageneric lineages of Quercus, distributed across the entire Northern Hemisphere. A revision of leaf fossils from lower Miocene to Pliocene deposits suggests that morphotypes of the Quercus drymeja complex are very similar to a number of extant Himalayan, East Asian, and Southeast Asian species of Quercus Group Ilex and may indicate subtropical, relatively humid conditions. Quercus mediterranea comprises leaf morphotypes that are encountered in modern Mediterranean species of Quercus Group Ilex, but also in Himalayan and East Asian members of this group indicating fully humid or summer-wet conditions. The fossil taxa Quercus drymeja and Q. mediterranea should be treated as morphotype complexes, which possibly comprised different biological species at different times. Quercus mediterranea, although readily recognizable as a distinct morphotype in early to late Miocene plant assemblages, may in fact represent small leaves of the same plants that constitute the Quercus drymeja complex. Based on the available evidence, the species forming the Q. drymeja complex and Q. mediterranea thrived in fully humid or summer-wet climates.. The onset of the modern vegetational context of Mediterranean sclerophyllous oaks is difficult to trace, but may have been during the latest Pliocene/early Pleistocene. (C) 2017 Elsevier B.V. All rights reserved