Miracle-dz/UniFAR-FTUs huggingface dataset:
Contribution of phase-mixing of Alfvén waves to coronal heating in multi-harmonic loop oscillations

Context. Kink oscillations of a coronal loop are observed and studied in detail because they provide a unique probe into the structure of coronal loops through magnetohydrodynamics (MHD) seismology and a potential test of coronal heating through the phase mixing of Alfvén waves. In particular, recent observations show that standing oscillations of loops often involve higher harmonics in addition to the fundamental mode. The damping of these kink oscillations is explained by mode coupling with Alfvén waves. Aims. We investigate the consequences for wave-based coronal heating of higher harmonics and which coronal heating observational signatures we may use to infer the presence of higher harmonic kink oscillations. Methods. We performed a set of non-ideal MHD simulations in which we modelled the damping of the kink oscillation of a flux tube via mode coupling. We based our MHD simulation parameters on the seismological inversion of an observation for which the first three harmonics are detected. We studied the phase mixing of Alfvén waves, which leads to the deposition of heat in the system, and we applied seismological inversion techniques to the MHD simulation output. Results. We find that the heating due to phase mixing of Alfvén waves triggered by the damping of kink oscillation is relatively small. We can however illustrate how the heating location drifts from subsequent damping of lower order harmonics. We also address the role of higher order harmonics and the width of the boundary shell in the energy deposition. Conclusions. We conclude that the coronal heating due to phase mixing does not seem to provide enough energy to maintain the thermal structure of the solar corona even when multi-harmonic oscillations are included; these oscillations play an inhibiting role in the development of smaller scale structures.
Studying the Effect of Financial Leverage and Ownership Structure on Investment Growth Opportunities

The main goal of the present research is to study the effect of financial leverage and ownership structure on investment growth opportunities in firms listed in Tehran Stock Exchange. To do so, 95 companies wee selected for the time period between 2006 and 2011 and the least squares' regression was utilized to test the research hypotheses. The criterion of growth opportunities was considered as the dependent variable and the indexes of financial leverage and institutional investors were considered as the independent variables of this research. Two hypotheses were posed regarding the issue. The results of testing the first hypothesis showed that there is a significant negative relationship between financial leverage and growth opportunities in firms listed in Tehran Stock Exchange. This means that the higher amount of the liabilities of a company will lead to lower investment growth opportunities. Also testing the second hypothesis showed that there is not any significant relationship between ownership structure and growth opportunities.
Experimental reduction of plant abundance changes interaction frequency of a tri‐trophic micro‐food web: contrasting responses of generalists and specialists

Species abundance is vulnerable to climate change and anthropogenic impact. Although numerous studies have examined the food web response to species loss, their response (e.g. in network topology and interaction frequency) to changes in species abundance has received little attention. We experimentally reduced the abundance (by c. 60%) of one host plant species (Saussurea nigrescens) in a tri‐trophic micro‐food web consisting of two common Asteraceae species (S. nigrescens and Anaphalis flavescens), their pre‐dispersal seed predators (tephritid flies) and the parasitoid wasps that feed on these seed predators. The neutral process hypothesis posits that network topology and interaction frequency are determined by the relative abundances of the participating species. Accordingly, we hypothesized that interaction frequency (indicated by the rate of flies infesting plants and of parasitoid wasps parasitizing flies) would decrease with decreasing abundance of host plant abundance. Consistent with the neutral process hypothesis, abundance reduction significantly decreased the rate of generalist flies infesting the manipulated plant host species, but increased the rate on unmanipulated plant species. In contrast, abundance reduction significantly increased the rate of specialist flies infesting the manipulated species, but it had no demonstrable effect on the specialists on the unmanipulated plant host. Moreover, abundance reduction significantly increased the rate of parasitoid wasps (as a species group) parasitizing flies in the manipulated species, but decreased the rate of the unmanipulated species. These results were not attributable to neutral processes, but can be explained by adaptive foraging theory. In addition, experimental manipulation did not shift the qualitative presence–absence of the linkages in the micro‐food web, and the change in the abundance of both fly and wasp species was smaller than the abundance changes of the manipulated plant species. Synthesis. Our results indicate that both neutral processes and/or adaptive foraging likely contributed to food web stability in responses to changes in species abundance. Because species abundance is vulnerable to abiotic and biotic environmental changes, we suggest more research should be conducted to understand how food webs respond to climate change and anthropogenic disturbance.
Characterization of precipitate formed during the removal of iron and precious metals from sulphate leach solutions

CITATION: Coetzee, R. , Dorfling, C. & Bradshaw, S. M. 2017. Characterization of precipitate formed during the removal of iron and precious metals from sulphate leach solutions. Journal of the Southern African Institute of Mining and Metallurgy, 117(8):771-778, doi:10.17159/2411-9717/2017/v117n8a7.
Effect of restricted feeding on compensatory growth responses in Clarias gariepinus (Burchell, 1822)

A four week feeding trial was carried out in a recycling water sytem to investigate the effect of restricted feeding regimes on compensatory growth and body composition in African catfish, Clarias gariepinus . A fishmeal-based diet containing 35% protein and 18 kJ g -1 gross energy (GE) was fed to triplicate groups of 30 fish. Fish were fed in five feeding schedules of 28 days : restricted 14 days + appetite 14 days; restricted 7 days + appetite 7 days; restricted 3 days + appetite 4 days; restricted 2 days + appetite 2 days. The restricted regime was achieved by feeding at the rate of 1% (maintenance ration) of their body weight per day, adjuted after weekly weighing. African catfish did not exhibit compansatory growth response under alternating periods of a feed restriction and appetite feeding. However, not sifnificant (P>0.05) values of feed and protein utilization were found under alternating periods of feed restriction and appetite feeding. Significantly higher (P 0.05) on body composition, organ indices, eviscerated carcass composition, viscera lipid and liver lipid. This study reveals that C. gariepinus failed to display compensatory growth response by alternating periods of restricted and appetite feeding.
Accumulation of Barium , Uranium , Cadmium and Manganese in the Sediment Core from the Pulau Cik Wan Dagang Mangrove Forests

The accumulation of elements Ba, U, Cd and Mn with respect to depth was determined in a 150 cm sediment core obtained from the mangrove forests of Pulau Cik Wan Dagang, Kuala Kemaman, Terengganu, Malaysia. Generally, all elements except Mn decrease with depth and their vertical profiles show a clear boundary at about 70 cm deep. In order to assess the influence of heavy metal pollution more precisely, enrichment factors (EF) were calculated. In this study, U and Cd have EF values significantly greater than unity and may therefore be considered to be predominantly anthropogenic in origin whereas Ba and Mn which have EF values about unity are considered to be predominantly terigenous in origin.
Adaptation of a Spatially-Explicit Individual- Based Forest Dynamics Model SORTIE-ND to Conifer-Broadleaved Mixed Stands in the University of Tokyo Hokkaido Forest

We calibrated a spatially-explicit individual-based forest dynamics model SORTIE-ND to conifer-broadleaved mixed stands in the Uni- versity of Tokyo Hokkaido Forest, and evaluated its accuracy of re- constructing past stand structure development under a single-tree selection system. We also modified the model so that it would be applicable under various geographic conditions by incorporating vari- ables that were derived from the Digital Elevation Model (DEM). We used inventory data collected from 12 permanent plots to estimate the model parameters. The analysis involved 23 tree species and species groups. The model consisted of five submodels: light, growth, mortality, snag dynamics, and recruitment. After the calibration, we evaluated model accuracy on a stand scale. The results of the evaluation showed that SORTIE-ND fairly accurately reconstructed the past development of basal area, diameter class distribution, and species composition. It was indicated that SORTIE-ND can be flexi- bly adapted to the regional characteristics of the study site, and has a large potential for exploring single-tree selection regimes that allow for the conservation of stand structure in conifer-broadleaved mixed stands.
Cooperative oscillatory behavior of mutually coupled dynamical systems

In this paper, we make a qualitative study of the dynamics of a network of diffusively coupled identical systems. In particular, we derive conditions on the systems and on the coupling strength between the systems that guarantee the global synchronization of the systems. It is shown that the notion of "minimum phaseness" of the individual systems involved is essential in ensuring synchronous behavior in the network when the coupling exceeds a certain computable threshold. On the other hand, it is shown that oscillatory behavior may arise in a network of identical globally asymptotically stable systems in case the isolated systems are nonminimum phase. In addition, we analyze the synchronization or nonsynchronization of the network in terms of its topology; that is, what happens if either the number of couplings and/or systems increases? The results are illustrated by computer simulations of coupled chaotic systems like the Rossler system and the Lorenz system.
Avoidance and locomotor behaviours of Armadillidium granulatum (Crustacea, Oniscidea) towards trace elements contaminated soils

ABSTRACT Behavioral responses to trace metals (TM) in Armadillidium granulatum Brandt, 1833 collected from Sebkha El Ouafi were studied under controlled laboratory conditions. Avoidance test was conducted in individuals exposed to cadmium (Cd), lead (Pb) and zinc (Zn) during 48 hours. The locomotor activity was studied under entraining conditions (LD) and constant darkness (DD) in the control animals as well as those exposed to contaminated soil. Whatever the tested metal, the animals did not show avoidance behavior. The determined efficient concentration (EC50) was equal to 3.4 mg/L for Cd, 451 mg/L for Pb and 1043 mg/L for Zn. Furthermore, results revealed the existence of nocturnal behavior whatever the experimental conditions. Periodogram analysis showed the existence of ultradian and circadian periods. This last was globally longer for contaminated specimens than the control ones under entraining conditions as well as under constant darkness. Exposed animals to cadmium showed the most important activity time under DD (αDD = 8h01 ± 3h27) contrary to that observed under nLD cycle (αLD = 3h43 ± 2h36). In addition, control specimens and those exposed to Cd and Pb were characterized by a phase delay contrary to those exposed to Zn which showed a phase advance.
Ecological and biological studies on the Nile tilapia Oreochromis niloticus along different sites of lake Burullus

ake Burullus represents an economically important lake in Egypt , due to its rich fishery resources. Unfortunately, the lake is exposed to many kinds of chemical and biological pollutants in addition to the remains of agricultural and wastes that are disposed into it. So, the aim of the present study was compare the quality of water samples collected from three different sites along lake Burullus; a site of the lake in contact with the Mediterranean sea called ElBoughaz inlet, western sector of the lake where agricultural drainage discharged and eastern sector where agricultural and industrial effluents. Water quality of samples collected from the different studied sites along the lake showed highly significant (P 0.05) Pb concentration. Bioaccumulation of either of the studied heavy metals in gills, liver, kidneys and muscles of the Nile tilapia; Oreochromis niloticus collected from the eastern and western sectors of the lake was much higher than that of fish collected from El-Boughaz inlet. Moreover, histopathological sections showed clear damage of gills, liver and kidney of fish collected from eastern and western sectors of the lake. Furthermore, Oreochromis niloticus collected from eastern and western sectors of the lake had lower condition factor values, hepatosomatic index, RBCs, Hb, Ht, serum total protein and total lipids but higher liver water contents, WBCs, MCV, MCH, serum glucose, AST, ALT, creatinine and uric acid. The obtained results also revealed that the meat quality of the collected fish from El-Boughaz inlet was more superior than those of fish collected from the eastern and western sectors of the lake.
TRAITS CORRELATED WITH DIFFERENTIAL DROUGHT TOLERANCE BETWEEN SELECTED SOYBEAN CULTIVARS

The present study aimed to determine differences in drought tolerance between three widely-cultivated soybean cultivars in Egypt. Two field experiments were conducted at the experimental farm and laboratories of the Agric. Bot. Dept., Fac. of Agric. , Mansoura Univ., Egypt during the two growing seasons of 2013 and 2014. The experimental design was a split-plot with two irrigation regimes in the main plots (control and water stress) and three cultivars in the sub-plots (Giza 22, Giza 35 and Giza 111). Results indicated that drought stress decreased seed yield, dry biomass, relative growth rate (RGR), net assimilation rate (NAR), relative water content (RWC), membrane stability index (MSI), whereas increased phenols, flavonoids, anthocyanins and proline content differentially between the tested cultivars. Drought tolerance index of cv. Giza 111 was significantly higher than other studied cultivars and this was accompanied with higher biomass accumulation, RGR, NAR, RWC, MSI as well as higher content of phenols, flavonoids, anthocyanins and proline. It was concluded that cv Giza 111 is better-adapted to drought-affected areas and could be utilized in breeding programs aiming to increase drought tolerance in soybean.
UAV wildlife radiotelemetry: System and methods of localization

The majority of bird and bat species are incapable of carrying tags that transmit their position to satellites. Given fundamental power requirements for such communication, burdened mass guidelines and battery technology, this constraint necessitates the continued use of very high frequency (VHF) radio beacons. As such, efforts should be made to mitigate their primary deficiencies: detection range, localization time and localization accuracy. The integration of a radiotelemetry system with an unmanned aerial vehicle (UAV) could significantly improve the capacity for data collection from VHF tags. We present a UAV‐integrated radiotelemetry system that relies on open source hardware and software. Localization methods, including signal processing, bearing estimation based on principal component analysis, localization techniques and test results, are discussed. Using a low‐power beacon applicable for bats and small birds, testing showed that the improved vantage of the UAV‐radiotelemetry system (UAV‐RT) provided significantly higher received signal power compared to the low‐level flights (maximum range beyond 1.4 km). Flight testing of localization methods showed median bearing errors between 2.3° and 6.8°, with localization errors of between 5% and 14% of the distance to the tag. In a direct comparison to an experienced radiotelemetry user, the UAV‐RT system provided bearing and localization estimates with 53% less error. This paper introduces the core functionality and use methods of the UAV‐RT system, while presenting baseline localization performance metrics. An associated website hosts plans for assembly and software installation. The methods of UAV‐RT use for tag detection will be further developed in future works. For both the detection and localization problems, the mobility of a flying asset drastically reduces tracker time requirements. A 7‐min flight would be sufficient to collect five equally spaced bearing estimates over a 1‐km transect. The use of a software‐defined radio on the UAV‐RT system will allow for the simultaneous detection and localization of multiple tags.
Effect of cysteine/serine changes to glucose-6-phosphate dehydrogenase of Synechocystis sp. PCC6803 in cell-free extracts

ABSTRACT In cyanobacteria and other photosynthetic organisms, the mechanism of glucose-6-phosphate dehydrogenase (G6PDH) regulation has long been hypothesized to be a disulphide bond formation/reduction between –SH groups of two internal cysteine residues. In this study, four cysteine codons in the zwf gene of Synechocystis sp. PCC6803 were changed to serine codons, and then each mutation was separately transferred to the chromosome, yielding four cysteine-mutant strains designated ZWFCS101, ZWFCS187, ZWFCS265 and ZWFCS445. Thus, cysteine-mutant G6PDH was analysed in cyanobacteria. Cell-free extracts of the other three mutants were used as an enzyme solution. The mutant ZWFCS187, located close to the active site, completely lost all enzyme activity. To test whether the redox sensitivity of the mutant enzymes was changed, reduced dithiothreitol (DTTred) was added to the enzyme solution immediately prior to the assay. Three of the mutant G6PDHs were found to still be sensitive. This result is inconsistent with other reports where the cysteine-mutant G6PDH lost redox sensitivity. The results herein indicate that redox regulation is not the sole mechanism for the regulation of G6PDH activity, and the regulation most probably involves a sum of interactions at the cellular level, as well as additional contributing factors.
Composition and Quality of Kareish Cheese Supplemented with Probiotic Bacteria and Dietary Fibers

The composition and quality of kareish cheeses made by adding 0.5 and 1% date seed powder (DSP) or 0.5 and 1% oat powder (OP) or their were evaluated at 0. 7, 14, 21 and 28 days of cold storage. The obtained results showed that the addition of DSP and OP was of no inhibitory effect on the starter activity. As the level of the different additives was increased, the coagulation time and curd tension decreased, while syneresis increased. All treated cheeses were of higher yield and total solids, compared with the control. It was also clear that most of samples characterized with higher decrease in acidity ,fat, salt ,salt in moisture ,total nitrogen (TN),TN/DM ,water soluble nitrogen (WSN), while WSN/TN was of higher increase of DSP and OP. Total bacterial count, lactic acid bacteria and bifidobacteria were higher in fiber supplemented fresh Kariesh cheese, while lower counts were recorded in all stored Kariesh cheese samples including control . All Kariesh cheese samples were free of coliform bacteria, either when fresh or during storage up to 4 weeks. Kariesh cheese containing DSP and OP was acceptable and of good flavour, body and texture, appearance . Generally, it could be recommended that the addition of date seed powder and oat powder and ABT starter could be applied in making good quality probiotic kareish cheese.
From Vagrant to Resident: occurrence, residency and births of leopard seals (Hydrurga leptonyx) in New Zealand waters

ABSTRACT In contrast to previous reports that leopard seals (Hydrurga leptonyx) are rare vagrants to New Zealand, we show that this species is a regular member of the marine fauna of this region. We present a first analysis from the New Zealand Leopard Seal Database – an extensive collation of 2,711 records of leopard seals within New Zealand between 1200 and 2018. Of these records, 51.2% (n = 1,408) were photographic. Leopard seal sightings have increased over time and been reported in all seasons and regions of New Zealand. Sightings are predominantly of adult individuals of good or excellent body condition, which differs to previous hypotheses suggesting that leopard seals visiting New Zealand shores are primarily juvenile animals in poor health condition. A total of 176 unique individuals have been identified in the New Zealand Leopard Seal Catalogue between 2014 and 2018 and preliminary results indicate that numbers per annum have continued to increase over time. Three leopard seal births and a number of juvenile animals (34% of the NZ records) have been documented. Considering the information presented here and the current definitions in the New Zealand Threat Classification System, the threat status of leopard seals within New Zealand waters should be reclassified from Vagrant to Resident.
Seasonal variation in chemical characteristics of soil organic matter of grazed and ungrazed mixed prairie and fescue grassland.

Highlight: At Manyberries and Stavely, Alberta, Mixed prairie and Fescue Grassland ranges were grazed at various intensities for 19 and 22 years, respectively. In 1973,13 chemical characteristics were determined on the organic matter developed in the soils of the ungrazed and heavy grazed treatments at the two locations. Samples were taken in spring, summer, autumn, and winter. Organic matter characteristics at both locations were closely associated with seasonal fluctuations and grazing-induced pressures; therefore, the time of sampling and the type of management before sampling soils should be defined in range studies. The results further emphasize the fragility of the equilibrium under which the organic matter of the soil of heavily grazed Mixed prairie at Manyberries forms and exists.
Fitness costs and benefits vary for two facultative Burkholderia symbionts of the social amoeba, Dictyostelium discoideum

Abstract Hosts and their associated microbes can enter into different relationships, which can range from mutualism, where both partners benefit, to exploitation, where one partner benefits at the expense of the other. Many host–microbe relationships have been presumed to be mutualistic, but frequently only benefits to the host, and not the microbial symbiont, have been considered. Here, we address this issue by looking at the effect of host association on the fitness of two facultative members of the Dictyostelium discoideum microbiome (Burkholderia agricolaris and Burkholderia hayleyella). Using two indicators of bacterial fitness, growth rate and abundance, we determined the effect of D. discoideum on Burkholderia fitness. In liquid culture, we found that D. discoideum amoebas lowered the growth rate of both Burkholderia species. In soil microcosms, we tracked the abundance of Burkholderia grown with and without D. discoideum over a month and found that B. hayleyella had larger populations when associating with D. discoideum while B. agricolaris was not significantly affected. Overall, we find that both B. agricolaris and B. hayleyella pay a cost to associate with D. discoideum, but B. hayleyella can also benefit under some conditions. Understanding how fitness varies in facultative symbionts will help us understand the persistence of host–symbiont relationships. OPEN RESEARCH BADGES This article has earned an Open Data Badge for making publicly available the digitally‐shareable data necessary to reproduce the reported results. The data is available at https://openscholarship.wustl. edu/data/15/