New Records, Biogeography, and Habitat Protection Needs of Four Species of Potamon (Decapoda: Brachyura) in Greece

Objectives are to determine the occurrence of species of Potamon in eastern Crete and the Aegean Islands (Chios, Naxos, Paros, Mykonos, Tinos and Andros); generate phylogenetic relationships among species to propose a biogeographic hypothesis relative to current distributions of the four species of the freshwater crab genus, Potamon, in Greece; and comment on the need to protect habitat suitable for the survival of species of Potamon in the country. Our collections, made in areas not previously sampled by researchers, indicate the presence of Potamon fluviatile on Tinos, N axos, and Andros, and Potamon potamios from central to eastern Crete; and verified the presence of Potamon ibericum on Chios. Cladistic analyses resulted in a single parsimonious tree (CI=85, RI=75). Potamon in the Balkan peninsula and islands in the Mediterranean region is a monophyletic group composed of two main clades: Clade 1 (P. fluviatile andPotamon algeriense) and Clade 2 (P. ibericum and its sister group composed of Potamon rhodium and Potamon potamios). Vicariant events (e.g. marine transgression and regression, orogeny, volcanism) are hypothesized as major factors that have shaped current distributions of species of Potamon in the Balkan Peninsula, Asia Minor, and the islands of the North Aegean Sea, Eastern Sporades, the Cyclades, and Crete. We recommend an increase in environmental education and communication among older and younger generations, agriculturalists, politicians, policy writers, land developers and economists to create an understanding for the need to protect land and aquatic environments that harbor unique species and the potential benefits for economic activities such as ecotourism. We also recommend the creation of an action plan to develop ecotourism around conservation areas ( e.g. from the source of existing springs downstream for about 200 m before the installation of water withdrawal equipment for irrigation and potable supplies) to generate revenue for funding protection initiatives and to promote green economic development that is ecologically and socio-culturally sustainable

Predicting Fish Species Diversity in Lotic Freshwaters of Greece

Objectives were to test the hypothesis that stream order and stream width alone account for species diversity in drainages of Greece, and to create a mathematical model that predicts fish diversity in small and medium sized freshwater streams in the southern Balkan Peninsula in accord with the stream classification system proposed by the European Environmental Agency (EEA). Thirty-seven species of fishes in 12 families (Petromyzontidae, Anguillidae, Cyprinidae, Moronidae, Centrarchidae, and Blenniidae) were collected in five stream orders (1-5) from 19 river drainages in Greece in 1993 and from 2000-2002. Numbers of species were significantly correlated with stream order (+), width (+), and depth (+), and elevation (-). Results of stepwise regression indicated that stream order, elevation, stream depth, and river km were significant factors associated with ichthyofaunal diversity, and were used to create a regression model to predict species diversity (up to 5th order streams). We conclude that geo-specific factors (i.e., small, isolated drainages with limited water budgets, geological history, dry climate, and low annual rainfall) should be included in the EEA monitoring design for lotic waters in harsh environments of southern Mediterranean countries as these features differ from those of central, eastern, and northern European countries with larger watersheds

Fish Consumption Patterns of Populations in Vicinities of Lake Kastoria and Lake Pamvotis, Greece

Objectives are to establish fish consumption patterns of populations in vicinities of two lakes (Kastoria and Pamvotis) in Greece for use in the assessment of risks associated with consumption of fishes in these agri-chemically impaired lakes. Parameters measured were demographics (i.e., gender, age, weight, education level, occupation, residency), freshwater fish eating frequency, species and sizes of fishes consumed, and fish consumption habits [i.e., quantity, parts, and preparation method). All annual mean site-specific consumption rates of the four gender-age class sub-populations surveyed in vicinity of Lake Kastoria (avg. range= 0.103-0.29 kg/day) exceed those of Greece (0.066 kg/day), EU (0.068 kg/day), Spain (0.104 kg/day), Portugal (0.159 kg/day), and the USEPA default value (0.054 kg/day) with two exceptions. Female consumption rates (0.087-0.103 kg/day) of Perca fluviatilis were below annual consumption rates of Spain and Portugal. Similarly, annual mean site-specific consumption rates of Anguilla anguilla and Cyprinus carpio by male (0.199-0.210 kg/day) and female adults (0.096-0.157 kg/day) in vicinity of Lake Pamvotis exceeded those of Greece, EU, Spain, Portugal, and the USEPA default value. Survey results indicate better-educated Greeks to be higher consumers of fish; however, market availability appears to be a stronger determinant of food choice in comparison to health education. All populations in vicinities of both lakes preferred to eat fried fishes with one exception: grilled C. carpio from Lake Pamvotis was preferred by female and male adults

Effects of Collection, Transport, and Redeployment Methods on Natural Mortality of Rangia cuneata (Mactridae) Used in Biomonitoring Studies

Sporadic, high mortality in test populations of wedge clams (Rangia cuneata) has limited the potential for using this otherwise desirable test organism in biomonitoring studies. To determine whether high mortality was due to ontogenic or experimental variables, a two-phased study was conducted. In phase I, mortality of collected and re-deployed wedge clams, subjected to varying transport conditions, was determined at 7, 14, 21 and 60 days re-deployment. The use of three transport times (1, 2, 3 hr.), two vehicle conditions (open, closed) and three transport treatments (open, closed, iced containers) yielded 18 test groups. Individual test group mortalities were below 10% through the 21 day re-deployment period and peaked at 13% at the 60 day re-deployment point. The low rates of mortality observed in phase I of this study indicate that reasonable collection and transport of wedge clams does not significantly increase natural mortality and suggests other parameters are more strongly correlated to test population mortality. In phase II of this study, percent survival of collected and acutely redeployed and acclimated redeployed wedge clams was determined. Acclimated re-deployment is the transfer of R. cuneata from saline to freshwater in decrements of 3-4 ppt/day in accord with recommendations in Bedford and Anderson (1972). Acute re-deployment is the placement of R. cuneata in lower salinity waters or freshwater without acclimation. Although percent survival of clams acutely deployed to the freshwater test site was significantly (

Systematic Ichthyofaunal Surveys in Urban and Non-Urban Watersheds

Objectives were to model fish species richness relative to natural and anthropogenic variables in Quantico Creek, a forested undisturbed stream environment, and Cameron Run, a highly disturbed urban stream environment in the lower Piedmont-Fall Line region of the Potomac River watershed. Species richness in all stream orders (e.g. avg. range=2.5-9.65 in 1st-3rd orders) of Quantico Creek were significantly higher than those (e.g. avg. range=2.1- 7.6 in 1st -4th orders) of Cameron Run. Fish species richness in Quantico Creek watershed can be modeled by eight factors: season, stream order, elevation, river km, stream width and depth, watershed size, and percent of undeveloped land cover; and that in Cameron Run can be modeled with four factors: stream gradient, stream flow, water temperature, and percent undeveloped land cover. Therefore, it cannot be assumed that a model composed of one set of variables that represents species richness for a given watershed can be applied to a nearby watershed. Based on potential impacts of increased population growth and climate change in the area, coupled with a paucity of information on the extent of the use of the lower reaches of Quantico Creek as a spawning area for anadromous fishes, we propose that the national park, Prince William Forest Park, should be included as a freshwater protection area for the Quantico Creek watershed as proposed by the National Park Service for 50 other national parks in the country. Data and models generated in our study can serve as baselines in future comparative studies of mid-Atlantic streams relative to changes in system parameters (e.g. human population, corresponding anthropogenic effects and climatic change predicted for the mid-Atlantic region)

Assessment of Human Health Risks from Chemically Contaminated Lake Fishes In Greece

Objectives were to conduct screening level surveys of locally consumed fish tissues in vicinities of two lakes (Kastoria and Pamvotis) in Greece to determine the presence of halogenated organic compounds and determine carcinogenic and non-carcinogenic human health risks associated with the consumption of sampled fish tissues. Results estimate the Incremental Lifetime Cancer Risks (ILCR) and Hazard Index (HI) values for the two local populations using site-specific population data. These results were compared to analyses conducted using U.S. Environmental Protection Agency default values in an effort to determine the applicability of USEPA default values to assessments of risks in non U.S. populations. Using site specific data, 87 % of the mean ILCRs calculated for total populations and sub-populations (i.e. female adult, female youth, male adult and male youth) consuming fishes from the two lakes we studied were above USEPA’s acceptable cancer risk of 1.0E-06; 53 % of the mean HIs were greater than 1.0. The USEPA default value (0.054 kg/d) for ingestion rate (IR) is considerably lower than the mean site specific IRs derived from populations in vicinity of Lake Kastoria (0.20; min.=0.09; max.=0.29 kg/d) and Lake Pamvotis (0.10; min.=0.01; max.=0.21 kg/d). These differences point to the need for the development of default values specific to the regions and population consumption patterns within Greece

The Structure of an RNAi Polymerase Links RNA Silencing and Transcription

RNA silencing refers to a group of RNA-induced gene-silencing mechanisms that developed early in the eukaryotic lineage, probably for defence against pathogens and regulation of gene expression. In plants, protozoa, fungi, and nematodes, but apparently not insects and vertebrates, it involves a cell-encoded RNA-dependent RNA polymerase (cRdRP) that produces double-stranded RNA triggers from aberrant single-stranded RNA. We report the 2.3-Å resolution crystal structure of QDE-1, a cRdRP from Neurospora crassa, and find that it forms a relatively compact dimeric molecule, each subunit of which comprises several domains with, at its core, a catalytic apparatus and protein fold strikingly similar to the catalytic core of the DNA-dependent RNA polymerases responsible for transcription. This evolutionary link between the two enzyme types suggests that aspects of RNA silencing in some organisms may recapitulate transcription/replication pathways functioning in the ancient RNA-based world

In vivo modeling of patient genetic heterogeneity identifies new ways to target cholangiocarcinoma.

L. Boulter was funded by The Wellcome Trust (207793/Z/17/Z), AMMF (2016/108, 2017/115), and Cancer Research UK (C52499/A27948). L. Boulter is also supported by an MRC university grant to the MRC Human Genetics Unit

A Kennicutt-Schmidt Law for Intervening Absorption Line Systems

We argue that most strong intervening metal absorption line systems, where the rest equivalent width of the MgII 2796A line is >0.5A, are interstellar material in, and outflowing from, star-forming disks. We show that a version of the Kennicutt-Schmidt law is readily obtained if the MgII equivalent widths are interpreted as kinematic broadening from absorbing gas in outflowing winds originating from star-forming galaxies. Taking a phenomenological approach and using a set of observational constraints available for star-forming galaxies, we are able to account for the density distribution of strong MgII absorbers over cosmic time. The association of intervening material with star-forming disks naturally explains the metallicity and dust content of strong MgII systems as well as their high HI column densities, and does not require the advection of metals from compact star-forming regions into the galaxy halos to account for the observations. We find that galaxies with a broad range of luminosities can give rise to absorption of a given rest-equivalent width, and discuss possible observational strategies to better quantify true galaxy-absorber associations and further test our model. We show that the redshift evolution in the density of absorbers closely tracks the star formation history of the universe and that strong intervening systems can be used to directly probe the physics of both bright and faint galaxies over a broad redshift range. By identifying strong intervening systems with galaxy disks and quantifying a version of the Kennicutt-Schmidt law that applies to them, a new probe of the interstellar medium is found which provides complementary information to that obtained through emission studies of galaxies. Implications of our results for galaxy feedback and enrichment of the intergalactic medium are discussed. [abridged]Comment: 23 pages, 15 figure