scholarly journals Temporal Dynamics of Jellyfish Pelagia noctiluca Stranded on the Mediterranean Coast of Morocco

2020 ◽  
Vol 21 (02) ◽  
pp. 87-94
Author(s):  
Bilal Mghili ◽  
Mohamed Analla ◽  
Mustapha Aksissou
Keyword(s):  
Atmospheric Pressure ◽  
High Frequency ◽  
Temporal Dynamics ◽  
Winter Season ◽  
Mediterranean Coast ◽  
The Other ◽  
Economic Activities ◽  
Annual Variations ◽  
Effective Strategies ◽  
Pelagia Noctiluca

Seasonal dynamics of the scyphomedusa Pelagia noctiluca were studied along with their relation to certain environmental factors between the study period that extends from January 2018 to December 2019. During 2018, stranded individuals of P. noctiluca appeared throughout this year, but their high frequency was reported in the summer. While in contrast, P. noctiluca in 2019 was reported in a very low number only during the winter season and had not been detected in the other seasons of this year. The overall results revealed that the inter-annual variations in the abundance of jellyfish were not significantly (P<0.05) correlated with water temperature, relative humidity and atmospheric pressure. Our results showed easterly winds as a significant predictor of P. noctiluca strandings. The bell diameters of examined jellyfish ranged from 30 to 130 mm, with mean of 72 mm. Stranded mature jellyfish individuals as well as young ones were recorded throughout the year 2018. The size distribution indicated that P. noctiluca can reproduce all around the year, with its more intense activityduring the spring. The continuing presence of P. noctiluca in the Moroccan Mediterranean makes it necessary to set effective strategies in order to prevent and minimize their impact on economic activities.

The Other Entrepreneurs - Migrant Economies as Spaces for Social Innovation?

2019 ◽  
Vol 16 (2) ◽  
pp. 265-271
Author(s):  
Claudia Lintner
Keyword(s):  
Social Innovation ◽  
Close Relation ◽  
The Other ◽  
Structural Level ◽  
Structured Interviews ◽  
Economic Activities ◽  
Migrant Entrepreneurship ◽  
False Dichotomy ◽  
Migrant Entrepreneurs ◽  
The One

This article analyses the relationship between migrant entrepreneurship, marginalisation and social innovation. It does so, by looking how their ‘otherness’ is used on the one hand to reproduce their marginalised situation in society and on the other to develop new living and working arrangements promoting social innovation in society. The paper is based on a qualitative study, which was carried out from March 2014- 2016. In this period, twenty semi-structured interviews were conducted with migrant entrepreneurs and experts. As the results show, migrant entrepreneurs are characterised by a false dichotomy of “native weakness” in economic self-organisation against the “classical strength” of majority entrepreneurs. It is shown that new possibilities of acting in the context of migrant entrepreneurship are mostly organised in close relation to the lifeworlds and specific needs deriving from this sphere. Social innovation processes initiated by migrant entrepreneurs through their economic activities thus develop on a micro level and are hence less apparent. Supportive networks are missing on a structural level, so it becomes difficult for single innovative initiatives to be long-lasting.

scholarly journals Electrophysiological aftereffects of high-frequency transcranial random noise stimulation (hf-tRNS): an EEG investigation

2021 ◽  
Author(s):  
Filippo Ghin ◽  
Louise O’Hare ◽  
Andrea Pavan
Keyword(s):  
High Frequency ◽  
Discrimination Task ◽  
Temporal Dynamics ◽  
Random Noise ◽  
Decomposition Analysis ◽  
Oscillatory Activity ◽  
Motion Direction ◽  
Time Frequency ◽  
Direction Discrimination ◽  
Transcranial Random Noise Stimulation

AbstractThere is evidence that high-frequency transcranial random noise stimulation (hf-tRNS) is effective in improving behavioural performance in several visual tasks. However, so far there has been limited research into the spatial and temporal characteristics of hf-tRNS-induced facilitatory effects. In the present study, electroencephalogram (EEG) was used to investigate the spatial and temporal dynamics of cortical activity modulated by offline hf-tRNS on performance on a motion direction discrimination task. We used EEG to measure the amplitude of motion-related VEPs over the parieto-occipital cortex, as well as oscillatory power spectral density (PSD) at rest. A time–frequency decomposition analysis was also performed to investigate the shift in event-related spectral perturbation (ERSP) in response to the motion stimuli between the pre- and post-stimulation period. The results showed that the accuracy of the motion direction discrimination task was not modulated by offline hf-tRNS. Although the motion task was able to elicit motion-dependent VEP components (P1, N2, and P2), none of them showed any significant change between pre- and post-stimulation. We also found a time-dependent increase of the PSD in alpha and beta bands regardless of the stimulation protocol. Finally, time–frequency analysis showed a modulation of ERSP power in the hf-tRNS condition for gamma activity when compared to pre-stimulation periods and Sham stimulation. Overall, these results show that offline hf-tRNS may induce moderate aftereffects in brain oscillatory activity.

scholarly journals Chance or Necessity—The Fungi Co−Occurring with Formica polyctena Ants

Insects ◽  
2021 ◽  
Vol 12 (3) ◽  
pp. 204
Author(s):  
Igor Siedlecki ◽  
Michał Gorczak ◽  
Alicja Okrasińska ◽  
Marta Wrzosek
Keyword(s):  
Molecular Identification ◽  
High Frequency ◽  
Its Rdna ◽  
The Other ◽  
Formica Polyctena ◽  
Ant Nests ◽  
Mutualistic Fungi ◽  
The Tropics ◽  
High Diversity ◽  
Better Than

Studies on carton nesting ants and domatia−dwelling ants have shown that ant–fungi interactions may be much more common and widespread than previously thought. Until now, studies focused predominantly on parasitic and mutualistic fungi–ant interactions occurring mostly in the tropics, neglecting less−obvious interactions involving the fungi common in ants’ surroundings in temperate climates. In our study, we characterized the mycobiota of the surroundings of Formica polyctena ants by identifying nearly 600 fungal colonies that were isolated externally from the bodies of F. polyctena workers. The ants were collected from mounds found in northern and central Poland. Isolated fungi were assigned to 20 genera via molecular identification (ITS rDNA barcoding). Among these, Penicillium strains were the most frequent, belonging to eight different taxonomic sections. Other common and widespread members of Eurotiales, such as Aspergillus spp., were isolated very rarely. In our study, we managed to characterize the genera of fungi commonly present on F. polyctena workers. Our results suggest that Penicillium, Trichoderma, Mucor, Schwanniomyces and Entomortierella are commonly present in F. polyctena surroundings. Additionally, the high diversity and high frequency of Penicillium colonies isolated from ants in this study suggest that representatives of this genus may be adapted to survive in ant nests environment better than the other fungal groups, or that they are preferentially sustained by the insects in nests.

Normal Synaptonemal Complex and Abnormal Recombination Nodules in Two Alleles of the Drosophila Meiotic Mutant mei-W68

Genetics ◽  
2003 ◽  
Vol 163 (4) ◽  
pp. 1337-1356 ◽  
Author(s):  
Adelaide T C Carpenter
Keyword(s):  
Electron Microscopy ◽  
Synaptonemal Complex ◽  
High Frequency ◽  
Serial Section ◽  
The Other ◽  
Wild Type ◽  
Recombination Nodules ◽  
Section Electron ◽  
Serial Section Electron Microscopy ◽  
Section Electron Microscopy

Abstract The meiotic phenotypes of two mutant alleles of the mei-W68 gene, 1 and L1, were studied by genetics and by serial-section electron microscopy. Despite no or reduced exchange, both mutant alleles have normal synaptonemal complex. However, neither has any early recombination nodules; instead, both exhibit high numbers of very long (up to 2 μm) structures here named “noodles.” These are hypothesized to be formed by the unchecked extension of identical but much shorter structures ephemerally seen in wild type, which may be precursors of early recombination nodules. Although the mei-W68L1 allele is identical to the mei-W681 allele in both the absence of early recombination nodules and a high frequency of noodles (i.e., it is amorphic for the noodle phene), it is hypomorphic in its effects on exchange and late recombination nodules. The differential effects of this allele on early and late recombination nodules are consistent with the hypothesis that Drosophila females have two separate recombination pathways—one for simple gene conversion, the other for exchange.

scholarly journals Lifting of Social Distancing Measures: Perspectives From Vietnam

2020 ◽  
pp. 1-3 ◽  
Author(s):  
Trang H.D. Nguyen
Keyword(s):  
Transmission Rate ◽  
The Other ◽  
Economic Recovery ◽  
Economic Activities ◽  
Social Distancing ◽  
Medical Products ◽  
Domestic Tourism ◽  
The Government

ABSTRACT While many nations are struggling to slow the transmission rate of the coronavirus disease 2019 (COVID-19), Vietnam has seen no new locally acquired cases since April 16. After implementing 22 d of nationwide social distancing, on April 23, the government of Vietnam announced the easing of social distancing measures. This allows the country to restart its socio-economic activities in a gradual, prudent manner. Domestic tourism and exports of agricultural and anti-COVID-19 medical products take priority over the other sectors in this postpandemic economic recovery. Importantly, the country needs to stay vigilant on the fight against the disease to prevent a possibility of another outbreak.

Predictions of Current Attachment at Thermionic Cathode for TIG Arcs

2008 ◽  
Vol 580-582 ◽  
pp. 319-322 ◽  
Author(s):  
Manabu Tanaka ◽  
Kentaro Yamamoto ◽  
Tashiro Shinichi ◽  
John J. Lowke
Keyword(s):  
Melting Point ◽  
Work Function ◽  
Atmospheric Pressure ◽  
The Other ◽  
Numerical Calculations ◽  
Maximum Temperature ◽  
Arc Plasma ◽  
Melting Points ◽  
Thermionic Cathode ◽  
Uniform Current

Study of current attachment at thermionic cathode for TIG arc at atmospheric pressure is attempted from numerical calculations of arc-electrodes unified model. The calculations show that the maximum temperature of arc plasma close to the cathode tip for W-2% ThO2 reaches 19,000 K and it is the highest value in comparison with the other temperatures for W-2% La2O3 and W-2% CeO2, because the current attachment at the cathode tip is constricted by a centralized limitation of liquid area of ThO2 due to its higher melting point. The calculations also show that, in cases of W- 2% La2O3 and W-2% CeO2, the liquid areas of La2O3 and Ce2O3 are widely expanded at the cathode tip due to their lower melting points and then produce uniform current attachments at the cathode. It is concluded that the current attachment at thermionic cathode is strongly dependent on work function, melting point and Richardson constant of emitter materials.

A Multiregion Model with Capital Accumulation and Endogenous Amenities

2007 ◽  
Vol 39 (9) ◽  
pp. 2248-2270 ◽  
Author(s):  
Wei-Bin Zhang
Keyword(s):  
Capital Accumulation ◽  
Comparative Statics ◽  
The Other ◽  
High Rate ◽  
Unique Equilibrium ◽  
Economic Activities ◽  
Technological Differences ◽  
National Output ◽  
Simulation Results ◽  
Wage Disparities

The author develops a multiregional growth model with endogenous amenity and capital accumulation for any number of regions. The simulation results demonstrate that the national dynamics have a unique equilibrium. Comparative statics analysis shows that, if environmental improvement occurs in the technologically advanced (less advanced) region, the national output rises (falls). As a region improves its technology, the other two regions' aggregated output levels fall—not only in relative, but also in absolute, terms. This implies that if any region has a high rate of technological change and the other regions remain technologically stationary, then economic activities will tend to be concentrated in the technologically advancing region. It is also shown that technological differences appear to play only a small role in accounting for spatial wage disparities and endowments.

LONG DURATION ECHOES FROM AURORA, METEORS, AND IONOSPHERIC BACK-SCATTER

1953 ◽  
Vol 31 (2) ◽  
pp. 171-181 ◽  
Author(s):  
D. W. R. McKinley ◽  
Peter M. Millman
Keyword(s):  
Long Range ◽  
High Frequency ◽  
The Other ◽  
Very High Frequency ◽  
Long Duration ◽  
E Region ◽  
Very High ◽  
Visual Observations

In the course of the Ottawa meteor program some unusual echoes have been detected on 33 Mc. Echoes from the aurora are discussed and correlated with visual observations. Two mechanisms of radio reflections from the aurora have been proposed but the data here presented are insufficient to favor one over the other. On Aug. 4, 1948, six extremely long duration meteor echoes were observed which may have been due to abnormal ionospheric conditions. From time to time since August, 1948, a weak semipermanent echo has been recorded, usually appearing at a range of about 80 km., and enduring up to an hour. It is suggested that this echo is due to back-scatter from the same sources in the lower E-region that are presumed to be responsible for long-range very high frequency propagation.

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