First record of a potential neonate tiger shark (Galeocerdo cuvier) at a remote oceanic island in the Eastern Tropical Pacific

Tiger sharks (Galeocerdo cuvier) play an important ecological role as top predators, yet knowledge of their reproductive ecology is scarce. Here, the authors report the first observation of a potential neonate G. cuvier at Cocos Island, a predator-dominated oceanic island in the Eastern Tropical Pacific (ETP). The individual was detected using baited remote underwater video stations (BRUVS). The cameras also detected female individuals potentially pregnant, suggesting that parturition may take place at or near the island. Nonetheless, it is still unclear if the presence of a single neonate is an isolated event or evidence that the species is using the island for reproduction.     

Limited antioxidant effect after consumption of a single dose of tomato sauce by young males,despite a rise in plasma lycopene

This study investigated the effect of a single dose of tomato sauce on healthy male volunteers in a randomized crossover study. Healthy male subjects (n = 10) were enrolled. Placebo (rice and olive oil) or tomato (tomato sauce, rice and olive oil) meals were provided to the volunteers. Blood and urine samples were taken before consumption of meal (0 h) and 2, 4, 6, 24 and 48 h after meal. Consumption of tomato sauce increased plasma lycopene level by 5–22%, with a maximum level at 24 h (p<0.01) after the meal. Levels of plasma F₂-isoprostanes, hydroxyeicosatetraenoic acid products, allantoin and urinary 8-hydroxy-2′-deoxyguanosine did not change after either meal, but urinary F₂-isoprostanes (p<0.05) significantly decreased at 48 h compared to 0 h after the tomato sauce meal. This study showed that a single dose of tomato sauce meal had only a limited antioxidant effect in vivo.     

miR-192 Directly Binds and Regulates Dicer1 Expression in Neuroblastoma

Neuroblastoma (NB) arises from the embryonic neural crest and is the most common extracranial solid tumor in children under 5 years of age. Reduced expression of Dicer1 has recently been shown to be in correlation with poor prognosis in NB patients. This study aimed to investigate the mechanisms that could lead to the down-regulation of Dicer1 in neuroblastoma. We used computational prediction to identify potential miRs down-regulating Dicer1 in neuroblastoma. One of the miRs that were predicted to target Dicer1 was miR-192. We measured the levels of miR-192 in 43 primary tumors using real time PCR. Following the silencing of miR-192, the levels of dicer1 cell viability, cell proliferation and migration capability were analyzed. Multivariate analysis identified miR-192 as an independent prognostic marker for relapse in neuroblastoma patients (p=0.04). We were able to show through a dual luciferase assay and side-directed mutational analysis that miR-192 directly binds the 3'' UTR of Dicer1 on positions 1232-1238 and 2282-2288. An increase in cell viability, proliferation and migration rates were evident in NB cells transfected with miR-192-mimic. Yet, there was a significant decrease in proliferation when NB cells were transfected with an miR-192-inhibitor We suggest that miR-192 might be a key player in NB by regulating Dicer1 expression.     

Evaluation of treatment options for well water contaminated with perfluorinated alkyl substances using life cycle assessment

Purpose

As knowledge grows of the potentially harmful effects of chemicals in widespread use, emerging contaminants have become a major source of concern and uncertainty for public health officials and water quality managers. Perfluorinated alkyl substances, often referred to as perfluorinated compounds, have come under recent scrutiny and are present in groundwater at many sites across the USA. We examine the life cycle impacts of treating drinking water at one such site.

Methods

We assembled life cycle models for groundwater treatment and bottled water delivery to residents of Wright-Patterson Air Force Base, Ohio, where wells were recently taken out of service due to concerns related to perfluoroalkyl and polyfluoroalkyl substance (PFAS) contamination. Two treatment methods, granular activated carbon filtration and ion-exchange columns, were modeled under a range of contaminant concentrations covering three orders of magnitude: 0.7, 7.0, and 70 μg/L PFAS. On-site infrastructure, operations, and adsorbent cycling were included in models. Impacts of bottled water production and supply were assessed using two data sets reflecting a range of production and supply chain assumptions. Uncertainty in input data was captured using Monte Carlo simulations.

Results and discussion

Results show that for contaminant concentrations below 70 μg/L, the dominant contributor to life cycle impacts is electricity use at the treatment facility. Production, reactivation, and disposal of treatment media become major sources of impact only at very high PFAS concentrations. Though the life cycle impacts of bottled water are up to three orders of magnitude higher than remediated groundwater on a volumetric basis, supplementing a contaminated water supply with bottled drinking water may result in lower life cycle human health impacts when only a small proportion of the total population is vulnerable.

Conclusions

These results provide quantitative data and proposed scenarios for water quality managers and risk management officials in developing plans to address PFAS contamination and emerging contaminants in general. However, more information on the direct human health effects of these poorly understood pollutants is needed before the trade-offs in life cycle health impacts can be comprehensively assessed.

     

Proline-specific aminopeptidase P prevents replication-associated genome instability

Genotoxic stress during DNA replication constitutes a serious threat to genome integrity and causes human diseases. Defects at different steps of DNA metabolism are known to induce replication stress, but the contribution of other aspects of cellular metabolism is less understood. We show that aminopeptidase P (APP1), a metalloprotease involved in the catabolism of peptides containing proline residues near their N-terminus, prevents replication-associated genome instability. Functional analysis of C. elegans mutants lacking APP-1 demonstrates that germ cells display replication defects including reduced proliferation, cell cycle arrest, and accumulation of mitotic DSBs. Despite these defects, app-1 mutants are competent in repairing DSBs induced by gamma irradiation, as well as SPO-11-dependent DSBs that initiate meiotic recombination. Moreover, in the absence of SPO-11, spontaneous DSBs arising in app-1 mutants are repaired as inter-homologue crossover events during meiosis, confirming that APP-1 is not required for homologous recombination. Thus, APP-1 prevents replication stress without having an apparent role in DSB repair. Depletion of APP1 (XPNPEP1) also causes DSB accumulation in mitotically-proliferating human cells, suggesting that APP1’s role in genome stability is evolutionarily conserved. Our findings uncover an unexpected role for APP1 in genome stability, suggesting functional connections between aminopeptidase-mediated protein catabolism and DNA replication.     

The Flexibility of Bacterial Cell Walls

S ummary . There are considerable differences in the extensibility of the cell walls of bacteria in different genera. Gram negative spp. examined were more flexible than the Gram positive ones.     

Microsatellite DNA analysis of spatial and temporal population structuring of <Emphasis Type="Italic">Phragmites australis</Emphasis> along the Hudson River Estuary

Phragmites australis is a perennial grass that has invaded wetlands of the northeastern United States over the past century. The Hudson River Estuary and surrounding watersheds are no exception in that populations of P. australis have spread dramatically along its shores and tributaries in the past 40 years. Recent studies have shown that genetically variable populations of P. australis can spread by seed dispersal in addition to clonal mechanisms. It is important to characterize the genetic variation of Hudson River populations as part of a management strategy for this species to determine the mechanisms by which its spreads and colonizes new habitats, particularly those with frequent anthropogenic disturbances. The goals of this study were to quantify levels of genetic variation and structuring in Hudson River populations of P. australis using microsatellite DNA analysis. A total of 354 culms of P. australis were collected from nine locations ranging from Albany, New York to Staten Island, New York in the summers of 2004 (N = 174) and 2011 (N = 180). Microsatellite data from eight loci indicated that the Hudson River Estuary has some of the highest levels of genetic variation of all U. S. Atlantic Coast regions containing P. australis. Gene diversity (Hs) across all loci in the 2004 collection was 0.45 (±0.02) and that of the 2011 collection was 0.47 (±0.07). Patches within sample sites were rarely monoclonal and had multiple genetic phenotypes. Moran’s Identity tests indicated that individuals within a patch were closely related, whereas little genetic relatedness was evident among individuals from sample sites >1 km apart. Spatial structuring was also not evident in autospatial correlation and principle coordinate analyses. These findings suggest that genetic diversity is maintained within stands by sexual reproduction and that seeds are important in dispersal of P. australis across the Hudson River Estuary. Ample habitats are available for establishment of new Phragmites stands due to high levels of anthropogenic disturbance from populations living along the Estuary. Wildlife managers should focus on monitoring habitats that provide seedbed for Phragmites and promote land use practices that prevent soil disturbance and establishment of new stands.     

Conservative N cycling despite high atmospheric deposition in early successional African tropical lowland forests

Plant and Soil - Many applied disciplines have recognized problems related to the practice of data analysis within their own communities. Some of them have even declared the existence of a...