High Active Area Research Articles

Rethinking spatial costs and benefits of fisheries in marine conservation

Fishing catch is often used as a cost in marine conservation planning to avoid areas of high fishing activity when identifying potential marine reserve locations. However, the theory of marine reserves indicates that reserves are more likely to benefit fisheries in areas of heavy fishing activity that would otherwise be overfished. Whether or not fishing catch is calculated as a cost depends on the balance of conservation and fisheries goals for a reserve, and thus is critical for policymakers to consider when designing marine reserve networks. This research shows the utility of running an inverted cost model of fishery catches during marine reserve spatial prioritization as a first step in a marine planning process oriented towards stabilizing local fisheries. This technique serves as a heuristic tool that may help conservation planners explore regions that would otherwise be overlooked if fisheries data were absent or integrated purely as a cost in the planning process. Drawing on data from Madagascar to illustrate our approach, this research demonstrates that the regions most frequently selected using the inverted cost model not only meet conservation targets, but are also those most accessible to community-based resource managers, the dominant management paradigm in Madagascar as well as in many developing countries.

The relationship between impact speed and the probability of pedestrian fatality during a vehicle-pedestrian crash: A systematic review and meta-analysis

BackgroundPedestrians struck in motorised vehicle crashes constitute the largest group of traffic fatalities worldwide. Excessive speed is the primary contributory factor in such crashes. The relationship between estimated impact speed and the risk of a pedestrian fatality has generated much debate concerning what should be a safe maximum speed limit for vehicles in high pedestrian active areas. MethodsFour electronic databases (MEDLINE, EMBASE, COMPENDEX, and SCOPUS) were searched to identify relevant studies. Records were assessed, and data retrieved independently by two authors in adherence with the PRISMA statement. The included studies reported data on pedestrian fatalities from motorised vehicle crashes with known estimated impact speed. Summary odds ratios (OR) were obtained using meta-regression models. Time trends and publication bias were assessed. ResultsFifty-five studies were identified for a full-text assessment, 27 met inclusion criteria, and 20 were included in a meta-analysis. The analyses found that when the estimated impact speed increases by 1 km/h, the odds of a pedestrian fatality increases on average by 11% (OR = 1.11, 95% CI: 1.10–1.12). The risk of a fatality reaches 5% at an estimated impact speed of 30 km/h, 10% at 37 km/h, 50% at 59 km/h, 75% at 69 km/h and 90% at 80 km/h. Evidence of publication bias and time trend bias among included studies were found. ConclusionsThe results of the meta-analysis support setting speed limits of 30–40 km/h for high pedestrian active areas. These speed limits are commonly used by best practice countries that have the lowest road fatality rates and that practice a Safe System Approach to road safety.

Hydrothermal eruptions at unstable crater lakes: Insights from the Boiling Lake, Dominica, Lesser Antilles

The Boiling Lake - a major touristic attraction in the Morne Trois Pitons National Park, Dominica's (West Indies) World Heritage site - is located in an area of high hydrothermal activity in the southern part of the island. This spectacular lake is characterized by unstable behavior which has been interpreted to result from the presence of a water body above a fluctuating gas-filled, or multi-phase vent system. The system produces a near-boiling lake that occasionally drains and refills with water, without any simple periodicity. Despite the fact that such unstable draining lakes are thought to be non-eruptive, the Boiling Lake is known to have sourced occasional small hydrothermal eruptions as well as toxic gas emissions which accompany the refilling phase of these drainage events. Similar explosive events seem also to be likely after landslide slumped rocks from steep altered crater walls cover the vent area in the lake leading to overpressurized conditions. In both cases, rock expulsion and gas release continue to pose serious threats for tourists and tour guides. While conceptual models exist describing possible mechanisms of the Boiling Lake drainage itself, little information exists to date regarding the trigger mechanisms related to the explosive events. Further, no estimation of the eruption processes and dynamics of these events has previously been attempted. To address this knowledge gap, we employ here a combined field- and laboratory-based approach in order to i) characterize the properties of the dominant lithologies from the crater walls at Boiling Lake, ii) determine how the ongoing alteration may affect their petrophysical properties (e.g., porosity and permeability), and iii) evaluate how water-saturated, unconsolidated wall rock materials behave when rapidly decompressed from a slightly elevated pressure and temperature conditions.Here, we propose that it is the petrophysical state of the materials involved (e.g. porosity, permeability and alteration-related strength) which controls the style and energy of these eruptions, as well as the potential for landslides from the crater walls. The experimentally simulated scenarios included in this study are: i) decompression from only slightly elevated pressure conditions inferred for small hydrothermal eruptions occurring after lake drainage events, and ii) decompression from rapidly enhanced pressure conditions produced by the capping and overpressurization of the vent area following landslide episodes. Ejection velocities obtained from rapid decompression experiments were used as input parameters for ballistic trajectory calculations, allowing for estimation of the potential area impacted by ejected debris.We anticipate that this study will serve as a contribution to the understanding of the hazard potential of future hydrothermal eruptions at unstable crater lakes in general, as well as providing direct insights into the ongoing hydrothermal activity at the Boiling Lake.

Spatial differences in genetic diversity and northward migration suggest genetic erosion along the boreal caribou southern range limit and continued range retraction.

With increasing human activities and associated landscape changes, distributions of terrestrial mammals become fragmented. These changes in distribution are often associated with reduced population sizes and loss of genetic connectivity and diversity (i.e., genetic erosion) which may further diminish a species' ability to respond to changing environmental conditions and lead to local population extinctions. We studied threatened boreal caribou (Rangifer tarandus caribou) populations across their distribution in Ontario/Manitoba (Canada) to assess changes in genetic diversity and connectivity in areas of high and low anthropogenic activity. Using data from >1,000 caribou and nine microsatellite loci, we assessed population genetic structure, genetic diversity, and recent migration rates using a combination of network and population genetic analyses. We used Bayesian clustering analyses to identify population genetic structure and explored spatial and temporal variation in those patterns by assembling networks based on R ST and F ST as historical and contemporary genetic edge distances, respectively. The Bayesian clustering analyses identified broad‐scale patterns of genetic structure and closely aligned with the R ST network. The F ST network revealed substantial contemporary genetic differentiation, particularly in areas presenting contemporary anthropogenic disturbances and habitat fragmentation. In general, relatively lower genetic diversity and greater genetic differentiation were detected along the southern range limit, differing from areas in the northern parts of the distribution. Moreover, estimation of migration rates suggested a northward movement of animals away from the southern range limit. The patterns of genetic erosion revealed in our study suggest ongoing range retraction of boreal caribou in central Canada.

The instability of gyrotactically trapped cell layers

Several metres below the coastal ocean surface there are areas of high ecological activity that contain thin layers of concentrated motile phytoplankton. Gyrotactic trapping has been proposed as a potential mechanism for layer formation of bottom-heavy swimming algae cells, especially in flows where the vorticity varies linearly with depth (Durhamet al.,Science, vol. 323(5917), 2009, pp. 1067–1070). Using a continuum model for dilute microswimmer suspensions, we report that an instability of a gyrotactically trapped cell layer can arise in a pressure-driven plane channel flow. The linear stability analysis reveals that the equilibrium cell-layer solution is hydrodynamically unstable due to negative microswimmer buoyancy (i.e. a gravitational instability) over a range of biologically relevant parameter values. The critical cell concentration for this instability is found to be$N_{c}\simeq 10^{4}~\text{cells}~\text{cm}^{-3}$, a value comparable to the typical maximum cell concentration observed in thin layers. This result indicates that the instability may be a potential mechanism for limiting the layer’s maximum cell concentration, especially in regions where turbulence is weak, and motivates the study of its nonlinear evolution, perhaps, in the presence of turbulence.

Spatially tracking carbon through the root–rhizosphere–soil system using laser ablation‐IRMS

AbstractThe intimate relationships between plant roots, rhizosphere, and soil are fostered by the release of organic compounds from the plant into soil through various forms of rhizodeposition and the simultaneous harvesting of nutrients from the soil to the plant. Here we present a method to spatially track and map the migration of plant‐derived carbon (C) through roots into the rhizosphere and surrounding soil using laser ablation‐isotope ratio mass spectrometry (LA‐IRMS). We used switchgrass microcosms containing soil from field plots at the Kellogg Biological Station (Hickory Corners, Michigan, USA) which have been cropped with switchgrass since 2008. We used a 13CO2 tracer to isotopically label switchgrass plants for two diel cycles and tracked subsequent movement of labeled C using the spatially specific (< 100 µm resolution) δ13C analysis enabled by LA‐IRMS. This approach permitted assessment of variable C flow through different roots and enabled mapping of spatial variability of C allocation to the rhizosphere. Highly 13C‐enriched C (consistent with production during the 13CO2 application period) extended ≈ 0.5–1 mm from the root into the soil, suggesting that the majority of recent plant‐derived C was within this distance of the root after 48 h. Tracking the physical extent of root exudation into the rhizosphere can help evaluate the localization of plant‐microbe interactions in highly variable subsurface environments, and the use of the isotopic label can differentiate freshly fixed C (presumably from root exudates) from other types of subsurface C (e.g., plant necromass and microbial turnover). The LA‐IRMS technique may also serve as a valuable screening technique to identify areas of high activity for additional microbial or geochemical assays.

BLOCK STRUCTURE OF THE SOUTHERN KURAI BASIN OF GORNY ALTAI ACCORDING TO GEOELECTRIC DATA COMPARED TO THE DISTRIBUTION OF EARTHQUAKE EPICENTERS

The Kurai Basin of Gorny Altai is located in the area of high seismic activity, which is involved in the focal zone of the 2003 M7.3 Chuya earthquake. Its aftershock process has not ceased yet, and shows the likelihood of major seismic events. The seismic monitoring records of the last 15 years after the devastating earthquake show the state of stress in the basin. A comprehensive field database has been consolidated from the studies of direct and alternating currents by electromagnetic methods, including transient electromagnetic sounding, vertical electrical sounding, and electric field tomography. Using a combination of the research techniques and the method of interpretation based on data inversion, it becomes possible to select optimal models, ensure higher reliability, and improve the contents of the study. The available seismological data are used to identify the zones of concentration of seismic events in the southern mountain frame of the Kurai Basin. Our study aims to determine and clarify the geoelectric structure of the southern troughs. The first section of the Southwestern trough is constructed, and the latitudinal fault boundaries of the Eshtykel graben are confirmed. A comparison of electromagnetic and seismic data for 2015 shows that the earthquake epicenters were mainly confined to the submeridional fault zones. In our study of the Southwestern trough, it is established that most of the earthquakes concentrated in active fault structures separating the blocks of varying depths, which are identified from the geoelectric data. The southern piedmont troughs of the Kurai Basin are cut by numerous faults of latitudinal and submeridional strikes.

Engineering hybrid CoMoS4/Ni3S2 nanostructures as efficient bifunctional electrocatalyst for overall water splitting

In overall water splitting, oxygen evolution reaction is a rate-determining step due to its complex reaction processes with sluggish kinetics, so design of bifunctional electrocatalyst with elaborated structure to improve the oxygen evolution reaction performance is critical to their efficient application in overall water splitting. Here bifunctional CoMoS4/Ni3S2 nanostructures are in situ synthesized by a self-templating strategy, and the morphology control of the CoMoS4 outlayer is simultaneously achieved through a unique evolution from CoMoO4 nanocolumns array to hollow CoMoS4 nanosheets array with porous structure. Benefited from the synergistic effect of Ni3S2 interlayer, as obtained electrode exhibits greatly enhanced oxygen evolution activity than single CoMoS4 electrode with well-preserved hydrogen evolution activity. It, together with the three-dimensional topographic structure of CoMoS4 outlayer with high active areas, offers a rather low cell voltage (1.568 V@10 mA cm−2) for overall water splitting in a two-electrode system. Accordingly, our results may open new opportunities to explore hybrid nanostructures as efficient bifunctional electrocatalyst for overall water splitting.

Landscaping of Residential Estates as a Mitigation Measure to Reduce Carbon Dioxide and Temperature Levels in Inner Ibadan City, Nigeria

This study assessed the spatial distribution of carbon dioxide emanation in selected residential estates and the impact of landscaping in reducing their levels in Ibadan metropolis. The study was carried out in high, medium and low commercial activity areas characterized by population density and traffic congestion within Ibadan city. CO<SUB>2</SUB> concentrations and temperature were measured at 4 hourly interval from 9am to 5pm for a period of seven consecutive days while numbers of trees/plants (biomass density) were counted, at 21 different points from seven areas each with high, medium and low commercial activities. Measurements were carried out with the aid of calibrated portable gas meters. The means CO<SUB>2</SUB> (ppm) were 542±95, 415±11 and 376±14 at 1.00 pm in the high, medium and low commercial activity areas respectively. CO<SUB>2</SUB> concentrations were generally higher than IPCC value, but highest in the afternoon. Temperature values were generally higher in the afternoon in high and medium commercial activity areas, but lower in the low commercial activity zones. Significantly, density of trees in low commercial activity areas (234.3±6.7) was higher compared to those in medium (22.8±0.5) and high (24.2±0.7) activity areas respectively. An inverse correlation was observed between CO<SUB>2</SUB> concentration and the density of trees (r=-0.456; p=0.038). The spatial distribution of CO<SUB>2</SUB> concentration in relation to landscaping revealed that CO<SUB>2</SUB> concentration reduces northward away from the urban core areas where there were fewer trees. The areas with low commercial activities had large numbers of trees while temperature and CO<SUB>2</SUB> flux were lower in these areas. Temperature and density of trees contribute significantly in explaining the CO<SUB>2</SUB> concentration (p=0.015). CO<SUB>2</SUB> concentrations and temperature were high in high commercial activities areas in Ibadan metropolis, few or no trees were observed in those areas. Increase in density of trees could be attributed to decrease in the CO<SUB>2</SUB> concentration. Hence, tree planting needs to be encouraged in the urban core of Ibadan metropolis to reduce air pollution.

СЕРЕДНЬОПЛЕЙСТОЦЕНОВА МІКРОТЕРІОФАУНА ПЕЧЕРНОГО МІСЦЕЗНАХОДЖЕННЯ ВІНЯВИ (ЛЬВІВСЬКА ОБЛАСТЬ)

A new locality of the Pleistocene small mammals at Vynyavy (L'viv region) has been discovered in the filling of rock shelters beneath the massive well-cemented sandstone of the Opillia Suite of the Badenian, the Middle Neogene. The locality was formed as a result of pellet accumulation. Predators, whose activity was forming the taphocoenosis, were birds and predatory beasts that inhabited the rock shelters and small caves in the looser underlying sandstone. The fauna includes fossils of insectivores, lagomorphs and rodents. The presence of Arvicolachosaricus and the evolutionary level of other arvicolidsallow identification this fauna as Khasarian one. The closest analogue of Vynyavy, with respect to the geological age, is a fauna from sub-moraine deposits of the Dnieper area, Matviivka. Ecologically, Vynyavy fauna shows similarity with Medzhybizh (Syngilian fauna of the Bug area). Geological age of the locality is the Middle Pleistocene, Dnieprovian climatolith, and, taking into account ecological features of the fauna, most likely, its beginning. On the basis of small mammal fauna, open steppe habitats should be reconstructed for the time span presented by Vynyavy fauna. Climate was colder than the present one, although not extremely cold, which is evidenced by the presence of insectivores. Climate was also wet enough, as soon as all xerophillous species are absent. Special characteristic feature is the absence of Laguridae, usual for the Pleistocene of Ukrainian group. Arctic component is presented by a lemming. High percentage of the water vole in the taphocoenosis indicates extensive areas of flood-plains and high fluvial activity, which could be expected during interstadials rather than during cold epochs. Otherwise, a decrease of seasonal floods would have resulted in foresting of valley and, as a consequence, in the appearance of forest mammal species, which are observed in Vinyavy fauna. Remains of ground squirrels belong to Spermophilusodessanus, a fact that supports a recent (Holocene) colonization of this area by its present inhabitant, S. citellus.

О молниестойкости ракет космического назначения

Recently, matters concerned with lightning protection and lightning resistance of space rockets are becoming of issue in connection with the fact that space launch facilities are constructed in areas of high lightning activity [1–3]. It is rather difficult to completely protect a rocket from the lightning impact using only the launcher lightning protection system. The rocket safety can be further enhanced only by imparting self-lightning resistance to the rocket. The article discusses matters concerned with selecting the rocket lightning protection and lightning resistance levels for enhancement of its safety. For monitoring possible lightning strike at the rocket, it is proposed to fit the rocket with equipment for measuring the lightning strike intensity at the rocket.

Spatial and temporal characterization (2006-2012) of the trawling activity in the Site of Community Importance "Volcanes de fango del golfo de Cádiz" (southwestern Iberian Peninsula).

Spatial and temporal characterization (2006-2012) of the trawling activity in the Site of Community Importance "Volcanes de fango del golfo de Cádiz" (southwestern Iberian Peninsula).

Label-free immunosensors based on a novel multi-amplification signal strategy of TiO2-NGO/Au@Pd hetero-nanostructures

A label-free electrochemical immunosensor for quantitative detection of human epididymis specific protein 4 antigen (HE4 Ag) was developed by a novel multi-amplification signal system. The multi-amplification signal system was formed by loading bimetallic Au@Pd holothurian-shaped nanoparticles (Au@Pd HSs) on titanium oxide nanoclusters functionalized nitrogen-doped reduced graphene oxide (TiO2-NGO). The Au@Pd HSs were obtained via seed-mediated approach with in-situ grown palladium nanoarms on gold nanorods (Au NRs) surfaces, which possessed good electrocatalysis for hydrogen peroxide (H2O2) reduction and excellent biocompatibility. The TiO2-NGO with the high catalytic activity and large specific surface area was synthesized by hydrothermal method. Using H2O2 as an electrochemically active substrate, the prepared label-free electrochemical immunosensor based on the TiO2-NGO/Au@Pd HSs hetero-nanostructures as the signal amplification platform exhibited excellent selectivity, reproducibility and stability for the detection of HE4 Ag. Meanwhile, the linear range from 40 fM to 60 nM with the detection limit of 13.33 fM (S/N = 3) was obtained, indicating the immunosensor offers a promising method for clinical detection of HE4 Ag.

Kelakuan Orbital Molekul Nanomangkin FeN4 /C untuk Tindak Balas Penurunan Oksigen (ORR) di Katod Sel Fuel Metanol Langsung (DMFC)

Approaching commercialization phase of Direct methanol fuel cell (DMFC) technology, developing high kinetic rate active area with inexpensive non-precious metal catalyst (NPMC) for ORR catalyst materials to replace currently used Pt-based catalysts is a compulsory and crucial requirement in order to reduce the catalyst and overall system cost. Thus, the objective of this study is to describe the molecule orbital behavior of NPMC FeN4/C and discuss of recent works in the area of non-precious metal electrocatalys for ORR. Several important kinds of free energy study for carbon supported non-precious metal electrocatalys for ORR by using density functional theory (DFT) in CASTEP module analysis. The properties of FeN4/C nanocatalyst were studied, and their energy properties, band structure and density of state were evaluated accordingly. Besides, electronic properties of the nanostructure of FeN4/C also calculated. The results indicated that optimized geometry shows the oxygen in 3.699 Ao from the catalyst opposite with the Fe atom. Moreover, HOMO occurs in the orbitals 173 and LUMO occur in orbitals 174 and the band gap -0.82 proved that FeN4/C nanostructure catalyst is conductive and suitable to use as catalyst in fuel cell.

Three-dimensional flower-like Pd3Pb nanocrystals enable efficient ethylene glycol electrocatalytic oxidation

Abstract Designing and developing cost-efficient catalysts for liquid fuel electrooxidation with excellent performances in the alkaline media are of paramount significance for the practical applications of direct fuel cells. Herein, we describe the design and fabrication of well-defined three-dimensional (3D) Pd3Pb nanocatalysts with flower-like structure. Specifically, benefiting from the high surface active areas and modified electronic structure, the as-obtained 3D flower-like Pd3Pb catalysts can exhibit outstanding electrocatalytic performances with the mass and specific activities of 4515.8 mA/mg and 10.0 mA/cm2 toward ethylene glycol oxidation reaction (EGOR), which are 4.3 and 5.0 times higher than those of benchmark Pd/C catalysts, respectively. Moreover, the resultant 3D flower-like Pd3Pb nanocrystals (NCs) can also maintain for 500 cycles potential CV with less catalytic degradation and morphology variation. This work not only affords a fascinating electrocatalysts for the liquid fuel oxidation but also manifests the significance of precise morphology control of catalysts for the application of fuel cells.

One-pot construction of N-doped graphene supported 3D PdAg nanoflower as efficient catalysts for ethylene glycol electrooxidation

Rational design and support introduction of electrocatalysts are significant for the improvement of their performances for electrooxidation reaction, but still a grand challenge. Herein, we developed a facile one-pot method to construct a unique class of N-doped graphene supported three-dimensional (3D) PdAg nanoflowers catalysts (denoted as PdAg NFs/NG) under the room temperature. It is found that the introduction of NG is beneficial for reducing the diameter of 3D PdAg NFs, where the synthesized PdAg NFs/NG show significantly enhanced electrocatalytic performances towards ethylene glycol oxidation reaction (EGOR). Specifically, benefiting from strong synergistic effect, modified electronic structure, largely improved conductivity, and high surface active areas, the resultant PdAg NFs/NG demonstrate the mass and specific activity of 5765.3 mA mg−1 and 11.9 mA cm−2 for the ethylene glycol electrooxidation, which are 5.4 and 5.95 times higher than those of commercial Pd/C catalysts, respectively. More importantly, after the successful introduction of NG, the PdAg NFs/NG also displays great improvement in durability, which retains the mass activity of 4208.7 mA mg−1 after long-term electrochemical measurement, 2.62 and 20.1 times larger than 3D PdAg NFs and Pd/C catalysts. The present work manifests the facile construction of advanced nanocatalysts with optimized functional properties.

Dose painting for re-irradiation of head and neck cancer

Background: For patients with recurrent or second primary disease, re-irradiation can be challenging due to overlap with previously irradiated volumes. Dose painting may be attractive for these patients, as the focus is on delivering maximal dose to areas of high tumor activity. Here, we compare dose painting by contours (DPBC) treatment plans based on 18F-fluorodeoxyglucose (FDG) positron emission tomography (PET) with conventional plans.Material and methods: We included 10 patients with recurrent or second primary head and neck cancer (HNC) eligible for re-irradiation. Our conventional re-irradiation regimen is hyperfractionated radiotherapy 1.5 Gy twice daily over 4 weeks, giving a total dose of 60 Gy. For DPBC, we defined two prescription volumes, PV33 and PV66, corresponding to 33 and 66% of the highest FDG uptake in the tumor. The clinical target volume (CTV) prescription dose was 60 Gy, PV33; 65–67 Gy and PV66; 70–73 Gy. The DPBC plan is to be given the first 20 fractions and the conventional plan the last 20 fractions. Dose to organs at risk (OARs) were compared for DPBC and conventional treatment. By summation of the initial curative plan and the re-irradiation plan, we also evaluated differences in dose to the 2 ccm hot spot (D2cc).Results: We achieved DPBC plans with adequate target coverage for all 10 patients. There were no significant differences in OAR doses between the standard plans and the DPBC plans (p=.7). Summation of the initial curative plan and the re-irradiation plan showed that the median D2cc increased from 130 Gy (range 113–132 Gy; conventional) to 140 Gy (range 115–145 Gy; DPBC).Conclusions: Our proposed DPBC could be straightforwardly implemented and all plans met the objectives. Re-irradiation of HNC with DPBC may increase tumor control without more side effects compared to conventional radiotherapy.

Heterogeneous public and local knowledge provides a qualitative indicator of coastal use by marine recreational fishers

Marine recreational fishing (MRF) benefits individuals and economies, but can also impact fish stocks and associated ecosystems. Fish are an important resource providing direct economic benefit through commercial and recreational exploitation, and more esoteric ecosystem services. It is important to consider recreational fishing in marine spatial planning, but spatial information on coastal utilisation for MRF is frequently lacking. Public sources of local knowledge were reviewed and the frequency of unique references to sites extracted. Sites were georeferenced using a gazetteer compiled from the Ordnance Survey and United Kingdom Hydrographic Office named sea features gazetteer and local knowledge sources. Recreational fishing site densities were calculated across 2700 km of coastline and this proxy indicator of coastal utilisation validated against two independent surveys using permutative Monte Carlo sampling to control for sparse and non-independent data. Site density had fair agreement with independent surveys, but standardization by shore length reduced this agreement. Applying a 3 by 3 box filter convolution to the spatial layers improved the agreement between local knowledge derived predictions of activity and those of directed surveys, and permutation testing showed that agreement did not arise as a result of the convolution itself. High and low activity areas were more accurately predicted than areas of intermediate activity. Site density derived from heterogeneous participant and local knowledge can produce qualitative predictions of where recreational fishers fish, and applying a convolution can improve the predictive power of data so derived. However, this approach will be subject to unquantifiable bias and may fail to identify areas highly valued by marine recreational fishers. Thus it should be used in conjunction with other information in decision making and may be best suited to inform the early stage sampling design of on-site surveys or to complement other data sets in mapping areas of importance to recreational fishers.

Bimetallic MnCo selenide yolk shell structures for efficient overall water splitting

In this work, we systematically investigate and compare the activity of MnCo-based electrocatalysts (i.e. selenide, oxide, and hydroxide) for the oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) in alkaline solutions. The result indicates that the selenides are oxidized upon OER and the surface generated oxides are the real OER active species. The MnCo selenides exhibit a significantly enhanced performance as compared to the oxide and hydroxide though the real active OER species of these three catalysts are essentially the same. The superior activity of MnCo selenides could be attributed to the high intrinsic conductivity and the high surface active area. Further, the synergy between Mn and Co lowers the energy barrier for catalysis and helps to stabilize the material. The bimetallic MnCo selenides with yolk shell structures possess the optimal electrochemical performance with a low cell voltage of 1.66 V at the current density of 50 mA cm−2, outperforming most of the earth-abundant electrocatalysts. Our work provides a better understanding of the active species of metal selenides and the origin of the performance disparity between selenides (-derived oxides) and oxides electrocatalysts.

Detection of geothermal anomalies using Landsat 8 TIRS data in Tulu Moye geothermal prospect, Main Ethiopian Rift

Despite the high geothermal potential of the Main Ethiopian Rift (MER), risks associated with the industry and the difficulty of identifying possible targets using ground surveys alone continue to impede the development of geothermal power diligence in Ethiopia. In this paper, we investigate the geothermal potential of the Tulu Moye prospect area in the MER using Landsat 8, which is an important and cost-effective method of detecting geothermal anomalies. Data with a path/row of 168/054 were obtained from the Landsat 8 Operational Land Imager (OLI) and Thermal Infrared (TIR) sensors for October 17, 2014. Based on radiometric calibration, atmospheric correction (with the 6S model) and an NDVI-based threshold method for calculating land surface emissivity, a split-window algorithm was applied to retrieve the land surface temperature (LST) of the study area. Results show LST values ranging from 292.2 to 315.8 K, with the highest values found in barren lands. A comparison of LST between the Moderate Resolution Imaging Spectroradiometer (MODIS) and Landsat 8 shows a maximum difference of 1.47 K. Anomalous areas were also discovered, where LST was about 3-9 K higher than the background area. We identified seven of these as areas of high geothermal activity in the Tulu Moye prospective geothermal area. Auxiliary data and overlay analysis tools eliminated any non-geothermal influences. The research reveals that the distribution of highy prospective geothermal areas is consistent with the development and distribution of faults in the study area. Magmatism is the thermal source and faults provide conduits for the heat to flow from earth’s interior to the surface, facilitating the presence of geothermal anomalies. Finally, TIR remote sensing methods prove to be a robust and cost-effective technique for detecting LST anomalies in the geologically active area of MER. Moreover, combining TIR remote sensing with knowledge of the structural geology of the area and geothermal mechanisms is an efficient approach to detecting geothermal areas.