Polychaete Annelid Dynamics in the Northern Gulf of Mexico, From Shallow Water to the Deep-Sea

Polychaete annelids dominated the macrobenthos in sediments located 5 to 9 km from the Deep Water Horizon (DWH) Oil Spill site five months after the event. Numbers of species, abundance, and biodiversity indices in the polychaete taxa were significantly lower than pre-spill values from similar depths in the eastern Gulf of Mexico (GoM). Both non-selective and selective deposit feeders were the most frequent feeding guilds, but their abundances were significantly lower. An increase in the number of carnivorous Sigalionidae may be a response to an accumulation of petroleum hydrocarbons on the sediment. The concentration of oil in the sediments was low and the source of the oil remains equivocal. Multivariate analyses illustrated the differences between communities near the DWH and those from prior studies in similar deep GoM habitats. In summary, Deep Water Horizon oil spill appears to have had a measurable impact on the polychaetes. A time series of benthic samples from 2004 to 2012 has been utilized to assess the influence of hypoxia on the mean sizes (wet weight) of polychaeteannelid worms.While the mean body size over the entire study was 3.99±4.66 mg wet weight per individual, the mean ranged from 2.97±2.87 mg during consistently hypoxic conditions ( 2 mg/L). The decline in size was due to the elimination of large species under hypoxic conditions, not a reduction in size within species. At 'severe' levels of hypoxia (< 1 mg/L), the smallest species also declined in abundance, whereas the ubiquitous ‘medium sized’ Paraprionospio pinnata flourished. The infaunal benthos of the upper continental slope, a transition zone between the dynamic continental shelf and the deep sea, has been sampled in 1983-85 and then again in 2000-02 at nine locations. The polychaete annelid worms, the dominant taxon within the samples, exhibited remarkable stability in abundance, diversity, depth-related zonation, and species composition (> 35% similarity in species) over that period. At 7 of the 9 locations, single appearances of several dominant species resulted in the 1983-85 samples being more abundant but less diverse than the 2000-02 survey

Associations between radiologist-defined semantic and automatically computed radiomic features in non-small cell lung cancer

Tumor phenotypes captured in computed tomography (CT) images can be described qualitatively and quantitatively using radiologist-defined “semantic” and computer-derived “radiomic” features, respectively. While both types of features have shown to be promising predictors of prognosis, the association between these groups of features remains unclear. We investigated the associations between semantic and radiomic features in CT images of 258 non-small cell lung adenocarcinomas. The tumor imaging phenotypes were described using 9 qualitative semantic features that were scored by radiologists, and 57 quantitative radiomic features that were automatically calculated using mathematical algorithms. Of the 9 semantic features, 3 were rated on a binary scale (cavitation, air bronchogram, and calcification) and 6 were rated on a categorical scale (texture, border definition, contour, lobulation, spiculation, and concavity). 32–41 radiomic features were associated with the binary semantic features (AUC = 0.56–0.76). The relationship between all radiomic features and the categorical semantic features ranged from weak to moderate (|Spearmen’s correlation| = 0.002–0.65). There are associations between semantic and radiomic features, however the associations were not strong despite being significant. Our results indicate that radiomic features may capture distinct tumor phenotypes that fail to be perceived by naked eye that semantic features do not describe and vice versa

Polychaete Annelid Biomass Size Spectra: The Effects of Hypoxia Stress

Quantitative benthic samples were taken during spring and summer at three locations on the Louisiana continental shelf from 2004 to 2012 to assess the influence of hypoxia on the mean sizes (wet weight) of polychaete annelid worms. While the mean body size over the entire study of 64 samples was 3.99 ± 4.66 mg wet weight per individual, the mean ranged from 2.97 ± 2.87 mg during consistently hypoxic conditions (&lt;2 mg/L) to a high of 7.13 ± 7.60 mg ( &lt; 0.01) under oxic conditions (&gt;2 mg/L). The variations in size within assemblages were estimated from conventional biomass size spectra (BSS) and normalized biomass size spectra (NBSS) across a broad range of oxygen concentrations. The decline in size was due to the elimination of large species under hypoxic conditions (&lt;2 mg/L), not a reduction in size within species. At &quot;severe&quot; levels of hypoxia (&lt;1 mg/L), the smallest species also declined in abundance, whereas the ubiquitous &quot;medium-sized&quot; Paraprionospio pinnata flourished. These results suggest that there will be enhanced selection for small sizes and species with enlarged branchial palps such as those in P. pinnata if, as predicted, hypoxia becomes more commonplace in time and space worldwide

A non-exhaustive survey revealed possible genetic similarity in mitochondrial adaptive evolution of marine fish species in the northwestern Pacific

Mitochondrial coding genes involved in the oxidative phosphorylation pathway play vitally important roles in energy production and thermal adaptation. Investigating the underlying molecular mechanism of mitochondrial adaptive evolution is crucial for understanding biodiversity and ecological radiation. In this study, we collated population genetic studies of marine fish species in the northwestern Pacific based on mitochondrial cytochrome b gene sequences, to investigate whether similar patterns could be detected in mitochondrial adaptive evolution. After filtering, nine studies containing eight marine fish species (Ammodytes personatus, Boleophthalmus pectinirostris, Larimichthys polyactis, Mugil cephalus, Pampus argenteus, Platycephalus sp.1, Sebastiscus marmoratus, and Trachidermus fasciatus) belonging to eight different families were retained. Multiple codon-based approaches were used to identify potential sites under selection in each species. By comparison, our results showed that the posterior part of the mitochondrial cytochrome b gene (particularly codon 372 and its neighboring sites) seemed to be involved in the adaptive evolution process, suggesting potential genetic similarity among distantly related species. We also summarized four types of adaptive patterns in the reviewed species, and suggest that the level of genetic differentiation and mitochondrial adaptive evolution might be correlated. Further studies are needed to confirm such relationship by detecting RNA-level evidence and investigating more species and samples

A genetic assessment of the population structure and demographic history of Odontamblyopus lacepedii (Perciformes, Amblyopinae) from the northwestern Pacific

Coupled with geological and geographical history, climatic oscillations during the Pleistocene period had remarkable effects on species biodiversity and distribution along the northwestern Pacific. To detect the population structure and demographic history of Odontamblyopus lacepedii, 547-bp fragments of the mitochondrial DNA control region were sequenced. A low level of nucleotide diversity (0.0065 ± 0.0037) and a high level of haplotype diversity (0.98 ± 0.01) was observed. The Maximum Likelihood (ML) and Bayesian Inference phylogenetic trees showed no significant genealogical structure corresponding to sampling locations. The results of AMOVA and pairwise FST values revealed some significant genetic differentiation among populations, and the isolation by distance (IBD) analysis supported that the genetic differentiation was associated with the geographic distances. The demographic history of O. lacepedii examined by neutrality tests, mismatch distribution analysis, and Bayesian Skyline Plots (BSP) analysis suggested a sudden population expansion, and the expansion time was estimated to be around the Pleistocene. We hypothesize that the climate changes during the Pleistocene, ocean currents, and larval dispersal capabilities have played an important role in shaping contemporary phylogeographic pattern and population structure of O. lacepedii

Non-Negligible Effects of UV Irradiation on Transformation and Environmental Risks of Microplastics in the Water Environment

Microplastics (MPs) are ubiquitous in environmental media, and their harmful effects on MPs on the ecosystem have attracted more and more attention. Once released into the environment, MPs can trigger oxidative degradation through ultraviolet (UV) to cause photoaging. Photoaging significantly affects the properties of MPs, which leads to changing their environmental behaviors and increasing environmental risks. In this review, the generation of MPs under UV irradiation and the influence of environmental factors on the photoaging of MPs were discussed. Photoaging of MPs is an important process affecting the migration, transformation and interaction of pollutants in water and soil. In order to fully predict the fate and environmental interaction of MPs, more researches are needed in the future to explore the photoaging behavior of different types of MPs under natural environmental conditions

Ecosystem Functioning of the Loess Plateau in China from Vegetation Restoration Relied Largely on Climate

Climate change and anthropogenic replantation are supposed to greatly change vegetation coverage and ecosystem stability and functions, e.g., net primary productivity (NPP), evapotranspiration (ET) and water use efficiency (WUE). Our study compared WUE of nature- and human-induced forest cover increase on the Loess Plateau since 2000 using satellite-derived Vegetation Continuous Fields (VCF), NPP, ET. This study also applied over 30 years of model-based NPP and meteorological observations to compare the stability and changes brought up by the Grain for Green Project. The result showed that the average forest coverage fraction increased from 7.1% (~4.5 × 104 km2) in 2000 to 11.2% (~7.3 × 104 km2) in 2014. Artificial forest cover increase occupied 76.43% of the significantly increasing tree cover regions. The role of revegetation practice in NPP and ET became gradually more dominant than climate factors in artificial forests from the northern to the southern part of the Loess Plateau. For areas experiencing limited forest coverage increase, artificial forest areas showed higher WUE than natural forest areas under similar mean annual precipitation (MAP). The difference in stability was small between neighboring natural and artificial forest areas. The northwest of the Loess Plateau had an increasing resilience, whereas the south of the Plateau had an increased resistance to precipitation and temperature change. The higher dependency of the northern reforested areas on climate fluctuation indicates a growing threat of water scarcity to the sustainability of anthropogenic reforestation in semi-arid regions

Angucycline Glycosides from an Intertidal Sediments Strain <i>Streptomyces</i> sp. and Their Cytotoxic Activity against Hepatoma Carcinoma Cells

Four angucycline glycosides including three new compounds landomycin N (1), galtamycin C (2) and vineomycin D (3), and a known homologue saquayamycin B (4), along with two alkaloids 1-acetyl-&#946;-carboline (5) and indole-3-acetic acid (6), were isolated from the fermentation broth of an intertidal sediments-derived Streptomyces sp. Their structures were established by IR, HR-ESI-MS, 1D and 2D NMR techniques. Among the isolated angucyclines, saquayamycin B (4) displayed potent cytotoxic activity against hepatoma carcinoma cells HepG-2, SMMC-7721 and plc-prf-5, with IC50 values 0.135, 0.033 and 0.244 &#956;M respectively, superior to doxorubicin. Saquayamycin B (4) also induced apoptosis in SMMC-7721 cells as detected by its morphological characteristics in 4&#8242;,6-diamidino-2-phenylindole (DAPI) staining experiment