Re-evaluation of Morphological Diagnostic Characteristics of <Emphasis Type="Italic">Hexapleomera</Emphasis> Dudich, 1931 (Crustacea: Tanaidacea), with Description of a New Species     

Jin?Hee?Wi  Chang-Keun?Kang  In?Tae?Lee  Hyeon?Gyeong?JeongEmail author 《Ocean Science Journal》2018,53(4):641-653

An undescribed species of Tanaidacea was collected from Yokji Harbor in the southern coast of Korea. Hexapleomera yokjidona n. sp. can be distinguished from other species of the genus by the distinguishing features of a uropod with five articles, a pleopod basal article lacking inner seta, a mandible setal row with two setae, maxilliped coxa with two proximal setae, pereonites 1–3 together longer than wide, and pereopods 2–3 propodus with three ventral setae. To prove that H. yokjidona is a new species, detailed morphological characteristics of both genders are described and a comprehensive comparison among the species of the genus is tabulated. Additionally, diagnostic characteristics previously used to identify the species of Hexapleomera are reassessed and upgraded.  相似文献   

Links between topography,moisture fluxes pathways and precipitation over South America     

Ramiro Ignacio Saurral  Inés Angela Camilloni  Tércio Ambrizzi 《Climate Dynamics》2015,45(3-4):777-789

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Foreword to the special issue on I Reunión Argentina de Geoquímica de la Superficie (I RAGSU) (First Argentine meeting on geochemistry of the earth’s surface)     

Pedro José Depetris  Andrea Inés Pasquini 《Environmental Earth Sciences》2012,65(2):409-410

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Effects of BPA and DES on longchin goby (Chasmichthys dolichognathus) in vitro during the oocyte maturation     

Baek HJ  Hwang IJ  Kim KS  Lee YD  Kim HB  Yoo MS 《Marine environmental research》2007,64(1):79-86

This study was performed in order to assess whether bisphenol (BPA) and diethylstilbestrol (DES) had agonistic or antagonistic effects on oocyte maturation using marine fish. We tested the effects of these chemicals on in vitro maturation, germinal vesicle breakdown (GVBD), assay using oocytes from the longchin goby, Chasmichthys dolichognathus. During the maturation process, low concentrations of BPA and DES triggered GVBD depending on the stage of oocyte development; BPA at 0.044 nM and DES at 0.037, 0.37, and 3.73 nM induced GVBD in 0.82-0.88 mm diameter oocytes (germinal vesicle located near the center of oocytes). In 0.76-0.80 mm diameter oocytes (fully vitellogenic oocytes), BPA induced GVBD at relatively higher concentrations (4.38, 43.8, and 438 nM). In 0.86-0.90 mm diameter oocytes, BPA and DES had no observable effect on GVBD at the concentrations tested. Oocytes with diameters between 0.82 and 0.88 mm appeared to be more sensitive to these chemicals. Moreover, our results showed that BPA and DES did not inhibit GVBD.  相似文献   

Spatial and Temporal Ion Dynamics on a Complex Hydrological System: The Lower Luján River (Buenos Aires,Argentina)     

Ruben J. Lombardo  Inés O’Farrell  María dos Santos Afonso 《Aquatic Geochemistry》2010,16(2):293-309

The interplay of the geochemistry of the lower stretch of the Luján River is analyzed with its natural geomorphology (basin features), local hydrometeorology (tidal regime and “sudestada” events) and the impact of polluted tributaries. Major ions, dissolved heavy metals and limnological variables were analyzed using multivariate techniques. The water quality of the mainstream of the Luján River, flowing through urbanized and industrialized areas is strongly and positively influenced by the input of the Paraná River through deltaic watercourses and is negatively impacted after receiving the discharge from polluted watercourses. The longitudinal spatial variations evidenced major discontinuities in the Lower Luján Basin, showing clearly the riverine and the deltaic water influenced zones. Seasonal variations were also marked and were either temperature driven or associated with the estuarine cycle and the “sudestada”.  相似文献   

Long-Term Trends in Intertidal and Subtidal Benthic Communities in Response to Water Quality Improvement Measures     

Paula Chainho  Gilda Silva  Michael F. Lane  José L. Costa  Tadeu Pereira  Carla Azeda  Pedro R. Almeida  Inês Metelo  Maria J. Costa 《Estuaries and Coasts》2010,33(6):1314-1326

Long-term monitoring studies are needed to understand changes in ecosystem status when restoration measures are implemented. A long-term data series (1996–2007) of the Tagus estuary (Portugal) intertidal and subtidal benthic communities was collected in a degraded area where mitigation measures were implemented. Multivariate analysis was used to analyze spatial and temporal patterns in benthic community composition and trends in five benthic community metrics (i.e., taxonomic richness, density, biomass, Shannon–Wiener diversity and the AMBI index) were also examined. The results revealed a clear separation between intertidal and subtidal assemblages, although they had 50% of taxa in common, including the most abundant. Significant positive trends were found for all metrics showing that both intertidal and subtidal communities responded to the restoration measures implemented. Nevertheless, biotic indices need some adaptation before being universally applied to intertidal and subtidal habitats.  相似文献   

High Temporal Resolution Spectroscopic Observations of the Flare Star V1054 Oph     

Inés Crespo-Chacón  David Montes  María José Fernández-Figueroa  Javier López-Santiago  David GarcÍa-Alvarez  Bernard H. Foing 《Astrophysics and Space Science》2004,292(1-4):697-703

We present the results of a high temporal resolution spectroscopic monitoring of the flare (UV Cet type) star V1054 Oph (Wolf 630AB), classified as a dM3.5e visual binary system. Intermediate resolution spectra have been taken during four nights (2–5 April 2001) using the IDS spectrograph of the 2.5 m Isaac Newton Telescope (INT) (La Palma, Canary Islands, Spain). The V1054 Oph spectra show very strong emission lines even in its quiescent state. The analysis of the temporal evolution of the observed emission lines (from H_β to H₁₁ and the Ca II H and K lines) reveals four strong flares and several weak flares. We have studied in detail the behaviour of the chromospheric lines during the different phases (pre-flare, impulsive and gradual decay) of these flares. The observed flares last from ～25 to 95 min. The equivalent width of the H_β line changes by a factor up to ～2.3. Broad wings and asymmetric (red-shifted) lines are observed as well.  相似文献   

Foreword     

Ana Inés Gómez de Castro 《Astrophysics and Space Science》2006,302(1-4):1-2

Protons of energy 10⁹ GeV and 10⁴ GeV accelerating by the magnetic field of very strongly magnetized neutron stars and of extreme Kerr-Newmann black holes (respectively) may undergo instantaneous decay.  相似文献   

Phytoplankton response to pH rise in a N-limited floodplain lake: relevance of N2-fixing heterocystous cyanobacteria     

Fernando Unrein  Inés O’Farrell  Irina Izaguirre  Rodrigo Sinistro  María dos Santos Afonso  Guillermo Tell 《Aquatic Sciences - Research Across Boundaries》2010,72(2):179-190

Phosphorus has been traditionally regarded as the controlling nutrient for phytoplankton growth, however, N-limitation is likely to occur in several environments. For example, nitrogen is considered the main nutrient limiting phytoplankton in floodplain lakes of the Paraná River basin. However, N₂-fixing heterocystous cyanobacteria (N₂-cyano) are usually absent in these water bodies. The low pH values frequently found may limit the development of these algae. We hypothesise that long-term lake isolation allows conspicuous phytoplankton growth during summer, resulting in high photosynthetic rates and pH. This scenario combined with low DIN (dissolved inorganic nitrogen) would favour the development of N₂-cyano. Phytoplankton composition was studied during 16 months in a vegetated and isolated floodplain lake in the Paraná basin. Additionally, pH was artificially increased in in situ mesocosms to test effects on phytoplankton structure. Lake phytoplankton was dominated by flagellates (cryptophytes and euglenophytes) and small coccoid algae (chlorophytes and colonial cyanobacteria). Algal biomass was highest during warm periods. Although pH increased up to 8.8 during the second summer period, N₂-cyano remained rare, most likely because of the high DIN concentration recorded. The alkalophilic diatom Cyclotella meneghiniana dominated and was positively correlated with pH. Conversely, PO₄⁼ concentrations in the mesocosm experiment were high and DIN remained relatively low. pH enhancement in the treated mesocosms (avg. pH = 8.2) promoted the development of N₂-cyano (Anabaena spp.) and C. meneghiniana, which after 1 month of incubation accounted together for 50% of the biomass in contrast to less than 1.6% in control containers. Our results support the hypothesis that during the warm season and under low DIN concentration, high pH favours N₂-cyano growth in these lakes. We provide new evidence supporting the idea that even under optimal nutrient conditions, N₂-cyano do not thrive unless other requirements are satisfied.  相似文献   

Patterns of spatial variation of nutrient content,epiphyte load and shoot size of Posidonia oceanica seagrass meadows (Mediterranean Sea)     

Inés Castejón‐Silvo  Jorge Terrados 《Marine Ecology》2012,33(2):165-175

Knowledge of patterns of spatial variability of vegetative development, epiphyte load and nutrient availability in seagrass meadows is essential for the adequate design of research and environmental monitoring programmes. Differences in shoot size, epiphyte load and nutrient content of leaves and epiphytes of the Mediterranean endemic seagrass Posidonia oceanica at spatial scales ranging from metres to hundreds of metres are evaluated using a hierarchical nested sampling design. The size and epiphyte load of P. oceanica shoots and the nitrogen and phosphorus content of leaves and epiphytes were different in most of the spatial scales considered. Sampling efforts concentrated at the metre scale incorporated most of the variability in size, epiphyte load and nutrient content of the leaves and epiphytes of P. oceanica shoots. Epiphyte load showed no correlation with nutrient content in the epiphytes or in the leaves. However, epiphyte load and shoot size were negatively correlated, which suggests that light penetration in the canopy may be a main determinant of epiphyte load.  相似文献