Morphological Variation In Atyaephyra Desmarestii (Millet, 1831) Within And Among Populations Over Its Geographical Range

In order to elucidate the distinction of Atyaephyra desmarestii subspecies (A. d. desmarestii, A. d. orientalis, A. d. stankoi and A. d. mesopotamica ) and investigate their geographical distribution in Greece, the main morphological features and somatometric ratios were studied in numerous specimens collected from a dense station network of Greek fresh waters. Specimens from Belgium, Portugal, Albania and Turkey were also examined. Atyaephyra desmarestii was found in western and northern Greece while it was absent in eastern Greece , the Aegean and the Ionian islands. The comparison of the obtained data with those of the literature revealed a clearly overlapping variability of the main key morphological features among the four subspecies. The results of this study indicate that the current A. desmarestii subspecies are not valid on the basis of the used key features. There is only one very variable species with many ecophenotypes

Self-organization approach for THz polaritonic metamaterials

In this paper we discuss the fabrication and the electromagnetic (EM) characterization of anisotropic eutectic metamaterials, consisting of cylindrical polaritonic LiF rods embedded in either KCl or NaCl polaritonic host. The fabrication was performed using the eutectics directional solidification self-organization approach. For the EM characterization the specular reflectance at far infrared, between 3 THz and 11 THz, was measured and also calculated by numerically solving Maxwell equations, obtaining good agreement between experimental and calculated spectra. Applying an effective medium approach to describe the response of our samples, we predicted a range of frequencies in which most of our systems behave as homogeneous anisotropic media with a hyperbolic dispersion relation, opening thus possibilities for using them in negative refractive index and imaging applications at THz range

Annotated checklist of brachyuran crabs (Crustacea, Decapoda) of the Iberian Peninsula (SW Europe)

Almost 50 years have passed since a group of reputed carcinologists (viz. Lipke B. Holthuis, Isabella Gordon and Jacques Forest) finished the posthumous work of Ricardo Zariquiey Álvarez (1968) on decapod crustaceans of the Iberian Peninsula. No lists of decapod fauna specifically covering this area have been published since then, and an update is needed. The current list of brachyuran crabs of the Iberian Peninsula comprises 140 species, which is 35 species more than the 105 valid species listed in Zariquiey Álvarez (1968). Systematic changes have affected the original classification, so now there are 20 superfamilies, 36 families and 77 genera. Additional species have been recorded in Iberian waters due to natural range expansions from nearby areas (Mediterranean and Atlantic), introductions by anthropogenic activities, and description of new taxa. Also, two species were synonymized. Several of these changes, based on evidence from larval morphology and/or molecular data, are detailed in this review. Although descriptions of crab species new to science are not expected to occur at a significant rate, an increase in the number of species in the Iberian Peninsula is expected to result from the introduction of alien species

Muscle Hypertrophy in Prepubescent Tennis Players: A Segmentation MRI Study

PURPOSE: To asses if tennis at prepubertal age elicits the hypertrophy of dominant arm muscles. METHODS: The volume of the muscles of both arms was determined using magnetic resonance imaging (MRI) in 7 male prepubertal tennis players (TP) and 7 non-active control subjects (CG) (mean age 11.0 ± 0.8 years, Tanner 1-2). RESULTS: TP had 13% greater total muscle volume in the dominant than in the contralateral arm. The magnitude of inter-arm asymmetry was greater in TP than in CG (13 vs 3%, P<0.001). The dominant arm of TP was 16% greater than the dominant arm of CG (P<0.01), whilst non-dominant arms had similar total muscle volumes in both groups (P = 0.25), after accounting for height as covariate. In TP, dominant deltoid (11%), forearm supinator (55%) and forearm flexors (21%) and extensors (25%) were hypertrophied compared to the contralateral arm (P<0.05). In CG, the dominant supinator muscle was bigger than its contralateral homonimous (63%, P<0.05). CONCLUSIONS: Tennis at prepubertal age is associated with marked hypertrophy of the dominant arm, leading to a marked level of asymmetry (+13%), much greater than observed in non-active controls (+3%). Therefore, tennis particpation at prepubertal age is associated with increased muscle volumes in dominant compared to the non-dominant arm, likely due to selectively hypertrophy of the loaded muscles

The Biodiversity of the Mediterranean Sea: Estimates, Patterns, and Threats

The Mediterranean Sea is a marine biodiversity hot spot. Here we combined an extensive literature analysis with expert opinions to update publicly available estimates of major taxa in this marine ecosystem and to revise and update several species lists. We also assessed overall spatial and temporal patterns of species diversity and identified major changes and threats. Our results listed approximately 17,000 marine species occurring in the Mediterranean Sea. However, our estimates of marine diversity are still incomplete as yet—undescribed species will be added in the future. Diversity for microbes is substantially underestimated, and the deep-sea areas and portions of the southern and eastern region are still poorly known. In addition, the invasion of alien species is a crucial factor that will continue to change the biodiversity of the Mediterranean, mainly in its eastern basin that can spread rapidly northwards and westwards due to the warming of the Mediterranean Sea. Spatial patterns showed a general decrease in biodiversity from northwestern to southeastern regions following a gradient of production, with some exceptions and caution due to gaps in our knowledge of the biota along the southern and eastern rims. Biodiversity was also generally higher in coastal areas and continental shelves, and decreases with depth. Temporal trends indicated that overexploitation and habitat loss have been the main human drivers of historical changes in biodiversity. At present, habitat loss and degradation, followed by fishing impacts, pollution, climate change, eutrophication, and the establishment of alien species are the most important threats and affect the greatest number of taxonomic groups. All these impacts are expected to grow in importance in the future, especially climate change and habitat degradation. The spatial identification of hot spots highlighted the ecological importance of most of the western Mediterranean shelves (and in particular, the Strait of Gibraltar and the adjacent Alboran Sea), western African coast, the Adriatic, and the Aegean Sea, which show high concentrations of endangered, threatened, or vulnerable species. The Levantine Basin, severely impacted by the invasion of species, is endangered as well

Influence of angle of view on judges&apos; evaluations of inverted cross in men&apos;s rings

The present study focuses on two factors that may influence the accuracy and precision of a judge&apos;s evaluation of the angular deviation error in &quot;inverted cross&quot; (angle of the arms away from the horizontal axis). 16 Greek judges of competitive gymnastics participated in an evaluation of the magnitude of the error in the skill. Photographs of the performance of 8 gymnasts were shown to the judges in triplicates in random order from three angles of observation (0°, 45°, and 90°) on a computer screen. The precision in the judges&apos; judgments was best at the 45° angle of observation and at angular deviations of 16° to 30°. Accuracy was influenced both by the judge&apos;s angle of observation and the gymnast&apos;s angular deviation, as well as by the interaction. Overall, judges may need to improve their ability to evaluate performance through training. Training may incorporate a variety of exercises in judging the inverted cross through augmented feedback of knowledge of results. © Perceptual and Motor Skills 2011