Marine species in ambient low‐oxygen regions subject to double jeopardy impacts of climate change

We have learned much about the impacts of warming on the productivity and distribution of marine organisms, but less about the impact of warming combined with other environmental stressors, including oxygen depletion. Also, the combined impact of multiple environmental stressors requires evaluation at the scales most relevant to resource managers. We use the Gulf of St. Lawrence, Canada, characterized by a large permanently hypoxic zone, as a case study. Species distribution models were used to predict the impact of multiple scenarios of warming and oxygen depletion on the local density of three commercially and ecologically important species. Substantial changes are projected within 20–40 years. A eurythermal depleted species already limited to shallow, oxygen‐rich refuge habitat (Atlantic cod) may be relatively uninfluenced by oxygen depletion but increase in density within refuge areas with warming. A more stenothermal, deep‐dwelling species (Greenland halibut) is projected to lose ~55% of its high‐density areas under the combined impacts of warming and oxygen depletion. Another deep‐dwelling, more eurythermal species (Northern shrimp) would lose ~4% of its high‐density areas due to oxygen depletion alone, but these impacts may be buffered by warming, which may increase density by 8% in less hypoxic areas, but decrease density by ~20% in the warmest parts of the region. Due to local climate variability and extreme events, and that our models cannot project changes in species sensitivity to hypoxia with warming, our results should be considered conservative. We present an approach to effectively evaluate the individual and cumulative impacts of multiple environmental stressors on a species‐by‐species basis at the scales most relevant to managers. Our study may provide a basis for work in other low‐oxygen regions and should contribute to a growing literature base in climate science, which will continue to be of support for resource managers as climate change accelerates.     

Potential for bowhead whale entanglement in cod and crab pot gear in the Bering Sea

Bowhead whales (Balaena mysticetus) of the western Arctic stock winter in ice‐covered continental shelf regions of the Bering Sea, where pot fisheries for crabs (Paralithodes and Chionoecetes spp.) and Pacific cod (Gadus macrocephalus) pose a risk of entanglement. In the winter of 2008–2009 and 2009–2010 the spatial distribution of 21 satellite tagged bowhead whales partially overlapped areas in which pot fisheries for cod and blue king crab (Paralithodes platypus) occurred. However, these fisheries ended before whales entered the fishing areas, thus avoiding temporal overlap. A fishery for snow crab (Chionoecetes opilio) typically runs from January to May and provides the greatest potential for bowhead whales to encounter active pot gear. Tagged whales did not enter the area of the snow crab fishery during this study and generally remained in areas with >90% sea ice concentration, which is too concentrated for crab boats to penetrate. Pack ice sometimes overruns active fishing areas, resulting in lost gear, which is the most likely source of entanglement. The western Arctic stock of bowhead whales was increasing as of 2004; as such, incidental mortality from commercial pot fisheries is probably negligible at this time. Regardless, entanglement may increase over time and should be monitored.     

Screening of commercial cyclic peptide as inhibitor NS5 methyltransferase of Dengue virus through Molecular Docking and Molecular Dynamics Simulation

Dengue has become a major global health threat, especially in tropical and subtropical regions. The development of antiviral agent targeting viral replication is really needed at this time. NS5 methyltransferase presents as a novel antiviral target. This enzyme plays an important role in the methylation of 5''-cap mRNA. Inhibition of the NS5 methyltransferase could inhibit dengue virus replication. In this research, two sites of NS5 methyltransferase (S-Adenosyl methionine/SAM binding site and RNA-cap site) were used as targets for inhibition. As much as 300 commercial cyclic peptides were screened to these target sites by means of molecular docking. Analysis of ligand-enzyme binding free energy and pharmacological prediction revealed two best ligands, namely [Tyr123] Prepro Endothelin (110-130), amide, human and Urotensin II, human. According to molecular dynamic simulation, both ligands maintain a stable complex conformation between enzyme and ligand at temperature 310 K and 312 K. Hence, Urotensin II, human is more reactive at 312 K than at 310 K. However, both ligands can be used as potential inhibitor candidates against NS5 methyltransferase of dengue virus with Urotensin II, human exposes more promising activity at 312 K.     

建兰规模化生产体系规范化探讨

对建兰规模化生产体系,包括园区建设、繁殖与栽培、日常管理、病虫害防治等主要环节进行规范化探讨,以期为建兰商品化生产提供参考。     

European smelt Osmerus eperlanus in the eastern Gulf of Finland,Baltic Sea: Stock status and fishery

In the eastern Gulf of Finland, European smelt Osmerus eperlanus occurs as an anadromous ecological form that spawns in coastal, low-salinity zones and in several rivers entering the gulf, most importantly in the River Neva. Osmerus eperlanus is a key commercial fish species for the population of St. Petersburg, and the city's fish symbol. However, the state of the smelt stock has considerably deteriorated over the past few decades. Monitoring shows that annual catches during 1965–1992 averaged 2274 t, compared to 292 t in 2002–2017, although some improvement is inidicated by a gradual increase in catches in recent years (e.g., to 595 t in 2017). This paper addresses long-term and recent changes in the fisheries for smelt in the eastern Gulf of Finland, including both commercial and recreational fisheries, and the range of fishing gears used. The commercial smelt fishery is mainly conducted during the spawning period (April–May) on migrating fish, using trap nets of various designs and beach seines. There has been an increase in recreational fisheries for smelt; in years when ice cover on the gulf during winter (December–April) is steady, recreational fishers from St. Petersburg, using hook and line, may catch quantities that are comparable to those of commercial catches. Several factors may account for the stock dynamics and associated changes in catches of smelt: these include a decrease in prey availability in the gulf; loss and degradation of spawning and nursery habitats, partly associated with large-scale hydroengineering operations in Neva Bay; and illegal, unreported and unregulated (IUU) fishing which became widespread in post-Soviet decades. In spite of a gradual increase in smelt abundance in the most recent 15 years, a failure to accurately monitor and manage the extent of IUU and recreational fishing for smelt, to assess the status of the stock, or to forecast catches, increases the risk of overfishing of the spawning stock.     

Biological control-based IPM in sweet pepper greenhouses using Amblyseius swirskii (Acari: Phytoseiidae)

The predatory mite Amblyseius swirskii Athias-Henriot (Acari: Phytoseiidae) has been evaluated as a potential biological control agent for whitefly and thrips, but it has yet to be demonstrated that the addition of A. swirskii to an existing biological control programme improves management of these pests in commercial greenhouses. Experiments were initiated at the beginning of the cropping season in greenhouses located in the two main sweet pepper growing areas of Spain. At each location, a randomised complete block design was used with four replicates and two treatments: (1) current biological control-based Integrated Pest Management standard or (2) this standard supplemented by introductions of A. swirskii. A. swirskii established and reproduced well in the crop and was the most abundant phytoseiid species during the experiment in the plots where it was released. It also provided significant reduction of the whitefly population and pest control costs compared to greenhouses employing the standard. However, the addition of A. swirskii did not reduce thrips populations with respect to plots not receiving the predatory mite, presumably due to the inclusion of the anthocorid bug Orius laevigatus Fieber (Heteroptera: Anthocoridae) which established well. These results make the inclusion of A. swirskii in IPM programmes for sweet pepper crops advisable for whitefly control.     

Life history and status of the shovelnose sturgeon, Scaphirhynchus platorynchus

The shovelnose sturgeon, Scaphirhynchus platorynchus, is a freshwater sturgeon of the Mississippi and Missouri rivers and their tributaries. It is one of the smaller North American sturgeons, seldom weighing more than 2.5 kg over most of its range except in the upper Missouri River, where individuals of over 7 kg have been found. Spawning occurs in spring at temperatures between 17 and 21 °C over rock or gravel substrate downstream from dams, near rock structures, or in tributaries. most males reach sexual maturity at 5 years, most females at 7 years. Adults do not spawn every year. Shovelnose sturgeon are found in large, turbid rivers and frequently concentrate in areas downstream from dams or at the mouths of tributaries. Population densities range up to 2500 fish per km. They are commonly found in areas of current over sandy bottoms or near rocky points or bars, where they feed primarily on aquatic invertebrates. The shovelnose sturgeon is classified as a sport species in 12 of 24 states where it occurs. Commercial harvest is allowed in seven states, where fresh shovelnose sturgeon sell for 55 to 88 cents per kg, smoked shovelnose for about $5.75 per kg, and roe from 33 to 110 dollars per kg. About 25 tons of shovelnose sturgeon are harvested commercially each year. Shovelnose sturgeon are considered extirpated in three states, fully protected in four states, and rare, threatened, or of special concern in eight states. Populations are considered stable throughout most of the upper Mississippi, lower Missouri, Red, and Atchafalaya rivers. Three states, Wyoming, West Virginia, and New Mexico, have developed plans to reintroduce the species into rivers where it has been extirpated.     

Factors limiting the commercial application of animal cells in culture

The application of quality control and assurance procedures to the components of animal cell cultures has transformed what was an art to a viable industrial technology. This results in the successful large scale operation of such cultures. However it is clear that the cost of obtaining a license to produce materials from animal cells in culture severely impedes the movement of products into the market place. It is therefore necessary to examine in more detail the reasons for the reluctance of the regulatory authorities to issue product licences and in particular to appreciate the way ethical issues influence this process. This paper reviews these issues and indicates a way ahead.     

Novel PARP-1 inhibitors based on a 2-propanoyl-3H-quinazolin-4-one scaffold

Poly(ADP-ribose)polymerase-I (PARP-1) enzyme is involved in maintaining DNA integrity and programmed cell death. A virtual screening of commercial libraries led to the identification of five novel scaffolds with inhibitory profile in the low nanomolar range. A hit-to-lead optimization led to the identification of a group of new potent PARP-1 inhibitors, acyl-piperazinylamides of 3-(4-oxo-3,4-dihydro-quinazolin-2-yl)-propionic acid. Molecular modeling studies highlighted the preponderant role of the propanoyl side chain.