species activity
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Author(s):  
Kambai Collina ◽  
Olatidoye Olaremi Rebecca ◽  
Mundi Francis Junior ◽  
Chomini Meyiwa Stephen ◽  
Adedire Oludare ◽  
...  

Competition occurs when individuals or different species are vying for the same resource which is in limited supply. Two complete competitors cannot coexist indefinitely, therefore competitors must differ to some degree in their resource use. The research was carried to investigate how resources are partitioned among the species of sunbirds found in Federal College of Forestry, Jos. Opportunistic sightings along a 200m transect was used for observation. Sunbirds were observed using binoculars between 6:30 – 8am and by 4:30 – 6pm. Six transects were purposively selected in the study area. Sightings along a 200m transect was used to observe; species of sunbird, sex of individual sunbird species, species of flowering plant visited by the sunbird species, activity or behaviour performed by the sunbird (probing, insect hunting, roosting, perching etc.) and duration of activity. Descriptive statistics, ANOVA and post hoc test was used to analyse the data obtained. Results showed that forty-three (43) plant species were utilised by the four (4) sunbird species found in the study site with Corymbia torelliana and Hamelia patens having the highest number of visit. These four sunbird species observed were; Scarlet-chested sunbird, Variable sunbird, Green-headed sunbird and the Copper sunbird. Mean number of plants visited shows that Green-headed sunbird visited more plants than the other three species (28.89) which was highly significant (p=0.001). Copper sunbird spent the highest foraging time (67.71) which showed no variation with the other species (p=0.516). Females of the sunbird species visit more plants species and spent more time foraging as compared to the males although there was no variation (p= 0.984 and p= 0.906 respectively). The activities of the males (perching, hovering, probing, feeding) was higher than that of females and had a high level of significance (p=0.001). Callistemon citrinus, Corymbia torelliana, Eucalyptus camaldulensis, Hamelia patens, Parkia biglobosa and Ziziphus mucronata were utilised by all the sunbird species. Scarlet-chested sunbirds spent more time probing which aids pollination of plants in the study site and hence ecologically important to the plants found in the study site.


2021 ◽  
Author(s):  
Gréta Nusová ◽  
Marcel Uhrin ◽  
Peter Kaňuch

Abstract The Erňa cave, a mass winter hibernaculum and important swarming site of the common pipistrelle, Pipistrellus pipistrellus, is located in the Slovak Karst, near the Košice urban agglomeration in eastern Slovakia. Over the past two decades, the unusual behaviour of late summer or autumn accidental but abundant occurrences of this species have been observed in buildings (so-called invasions) in Košice. It has been hypothesised that these events are related to bats swarming and hibernating in the Erňa cave; however, causality has not been confirmed. We measured the relative activity of bats from the end of the breeding season through the invasions and autumn swarming prior to the onset of hibernation by recording their echolocation calls on car-based transects in order to find any spatial and temporal linkage between activity in the urban area and the swarming site. Over two years we recorded 6,253 sequences with echolocation calls of P. pipistrellus and 5,239 records of other bats along four transects totalling 7,121 km in length. Spatial pattern analysis found that the city agglomeration presented a local hotspot of the species’ activity, especially during the invasion season. Multivariate generalised additive modelling confirmed an increased density of records of P. pipistrellus between the urban area and the hibernaculum in the pre-hibernation season, whereas this pattern was not found to be consistent on the control transects near the city. Contrary to that, other bat species showed little variation in their activity between transects and seasons. The obtained results suggest that the relatively short geographical distance between the urban agglomeration and the large swarming site is likely a clue to the frequent city invasions of the species, although the role of the city as a hibernation area cannot be completely omitted.


2021 ◽  
Vol 20 (1) ◽  
Author(s):  
Benjamin Schmuck ◽  
Gefei Chen ◽  
Josef Pelcman ◽  
Nina Kronqvist ◽  
Anna Rising ◽  
...  

Abstract Background The human Bri2 BRICHOS domain inhibits amyloid formation and toxicity and could be used as a therapeutic agent against amyloid diseases. For translation into clinical use, large quantities of correctly folded recombinant human (rh) Bri2 BRICHOS are required. To increase the expression and solubility levels of rh Bri2 BRICHOS it was fused to NT*, a solubility tag derived from the N-terminal domain of a spider silk protein, which significantly increases expression levels and solubility of target proteins. To increase the expression levels even further and reach the g/L range, which is a prerequisite for an economical production on an industrial scale, we developed a fed-batch expression protocol for Escherichia coli. Results A fed-batch production method for NT*-Bri2 BRICHOS was set up and systematically optimized. This gradual improvement resulted in expression levels of up to 18.8 g/L. Following expression, NT*-Bri2 BRICHOS was purified by chromatographic methods to a final yield of up to 6.5 g/L. After removal of the NT*-tag and separation into different oligomeric species, activity assays verified that different assembly states of the fed-batch produced rh Bri2 BRICHOS have the same ability to inhibit fibrillar and non-fibrillar protein aggregation as the reference protein isolated from shake flask cultures. Conclusions The protocol developed in this work allows the production of large quantities of rh Bri2 BRICHOS using the solubility enhancing NT*-tag as a fusion partner, which is required to effectively conduct pre-clinical research.


2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Bonnie Cooper ◽  
Robert M. McPeek

The superior colliculus (SC) has long been associated with the neural control of eye movements. Over seventy years ago, the orderly topography of saccade vectors and corresponding visual field locations was discovered in the cat SC. Since then, numerous high-impact studies have investigated and manipulated the relationship between visuotopic space and saccade vector across this topography to better understand the physiological underpinnings of the sensorimotor signal transformation. However, less attention has been paid to the other motor responses that may be associated with SC activity, ranging in complexity from concerted movements of skeletomotor muscle groups, such as arm-reaching movements, to behaviors that involve whole-body movement sequences, such as fight-or-flight responses in murine models. This review surveys these more complex movements associated with SC (optic tectum in nonmammalian species) activity and, where possible, provides phylogenetic and ethological perspective. Expected final online publication date for the Annual Review of Vision Science, Volume 7 is September 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.


2021 ◽  
Vol 19 (1) ◽  
pp. 7-23
Author(s):  
Samvel KHUDOYAN

In recent decades, interest in stages of human development sufficiently decreased. The existing stage theories were hardly criticised for methodological issues, insufficient empirical validity, but rare attempts have been made to solve these issues. As a result, contemporary developmental psychology is constructed on the basis of worldly division of ages (infancy, childhood, adolescence, etc.), but not a scientific classification. We offer an explanatory life-span developmental theory based on the functional approach. According to this theory, the function of each developmental stage is to achieve a specific goal by solving a certain developmental problem through a special developmental program. There are four developmental problems and, accordingly, four stages identified. The first problem/stage is the formation of the subject of species activity (0–7 years); the second stage is aimed at developing the subject of sexual activity (8–20, 22 years). During the third stage, a subject of family and work activity forms (20, 22–40, 45 years), and the meaning of the last stage is self-exhaustion (from age 40, 45 until the end of life).


Biomolecules ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 497
Author(s):  
Dana Harshuk-Shabso ◽  
Noam Castel ◽  
Ran Israeli ◽  
Sheri Harari ◽  
Elah Pick

The COP9 signalosome (CSN) is a highly conserved eukaryotic multi-subunit enzyme, regulating cullin RING ligase activities and accordingly, substrate ubiquitination and degradation. We showed that the CSN complex of Saccharomyces cerevisiae that is deviated in subunit composition and in sequence homology harbors a highly conserved cullin deneddylase enzymatic core complex. We took advantage of the non-essentiality of the S. cerevisiae CSN-NEDD8/Rub1 axis, together with the enzyme-substrate cross-species activity, to develop a sensitive fluorescence readout assay, suitable for biochemical assessment of cullin deneddylation by CSNs from various origins. We also demonstrated that the yeast catalytic subunit, CSN5/Jab1, is targeted by an inhibitor that was selected for the human orthologue. Treatment of yeast by the inhibitor led to the accumulation of neddylated cullins and the formation of reactive oxygen species. Overall, our data revealed S. cerevisiae as a general platform that can be used for studies of CSN deneddylation and for testing the efficacy of selected CSN inhibitors.


2021 ◽  
Vol 75 (4) ◽  
Author(s):  
Cecilia Montauban ◽  
Maria Mas ◽  
Carme Tuneu-Corral ◽  
Owen S. Wangensteen ◽  
Ivana Budinski ◽  
...  

Abstract Animals modify their behaviours and interactions in response to changing environments. In bats, environmental adaptations are reflected in echolocation signalling that is used for navigation, foraging and communication. However, the extent and drivers of echolocation plasticity are not fully understood, hindering our identification of bat species with ultrasonic detectors, particularly for cryptic species with similar echolocation calls. We used a combination of DNA barcoding, intensive trapping, roost and emergence surveys and acoustic recording to study a widespread European cryptic species complex (Pipistrellus pipistrellus and Pipistrellus pygmaeus) to investigate whether sibling bat species could exhibit extreme echolocation plasticity in response to certain environmental conditions or behaviours. We found that P. pygmaeus occupied the acoustic niche of their absent congeneric species, producing calls with P. pipistrellus’ characteristic structure and peak frequencies and resulting in false positive acoustic records of that species. Echolocation frequency was significantly affected by the density of bats and by maternity rearing stage, with lower frequency calls emitted when there was a high density of flying bats, and by mothers while juveniles were non-volant. During roost emergence, 29% of calls had peak frequencies typical of P. pipistrellus, with calls as low as 44 kHz, lower than ever documented. We show that automatic and manual call classifiers fail to account for echolocation plasticity, misidentifying P. pygmaeus as P. pipistrellus. Our study raises a vital limitation of using only acoustic sampling in areas with high densities of a single species of a cryptic species pair, with important implications for bat monitoring. Significance statement Ultrasonic acoustic detectors are widely used in bat research to establish species inventories and monitor species activity through identification of echolocation calls, enabling new methods to study and understand this elusive understudied group of nocturnal mammals. However, echolocation call signalling in bats is intrinsically different to that of other taxa, serving a main function of navigation and foraging. This study demonstrates an extreme level of plasticity, showing large variation in call frequency and structure in different situations. We showcase the difficulty and limitation in using acoustic sampling alone for bat monitoring and the complications of setting parameters for species identification for manual and automatic call classifiers. Our observations of call frequency variation correlated with density and absence of congenerics provide novel insights of behavioural echolocation plasticity in bats.


2021 ◽  
Vol 25 (01) ◽  
pp. 34-46
Author(s):  
Alan Deivid Pereira ◽  
◽  
Marcelo Hideki Shigaki Yabu ◽  
Iago Vinicios Geller ◽  
Carlos Rodrigo Lehn ◽  
...  

Animal-vehicle collisions are the main negative impact of roads on wildlife, where they cause population declines, shifts in community structure, and potential changes in species behavior. Here, we determined mammal roadkill rates and the hotspots with higher rates for medium- and large-bodied mammals on the Highway PR-445 in the state of Paraná, Brazil. We have also evaluated possible differences in the frequency of roadkills concerning species activity patterns and their feeding habits. In doing so, we monitored the PR-445 twice a week between the kilometers 1 and 76, from March 2018 to March 2019, totaling 7296 km after 96 trips. We have recorded 93 mammal roadkills belonging to 17 species, representing a rate of 0.013 individual/km/day. The Carnivora, Didelphimorphia, and Cingulata orders showed to be the most common representatives among the roadkills. Omnivores were more prone to get hit by vehicles than herbivores and carnivores. The type of mammal activity pattern was not determinant in explaining the differences in roadkill rates. Highways in Paraná are among the roads that register the highest number of vehicle collisions with vertebrates in the country. This issue, together with extensive habitat loss and fragmentation, increases the threats to the relictual fauna. Our results indicate that the regions with the highest incidence of mammal roadkills on PR-445 are those close to stretches over rivers and with remnants of native vegetation. Thus, we emphasize that more comprehensive measures (e.g., wildlife passages and speed reducers) are essential to mitigate the impact of roads on wildlife.


2021 ◽  
Vol 288 (1945) ◽  
pp. 20202273
Author(s):  
Dan A. Greenberg ◽  
Wendy J. Palen

Concerns over the consequences of global climate change for biodiversity have spurred a renewed interest in organismal thermal physiology. However, temperature is only one of many environmental axes poised to change in the future. In particular, hydrologic regimes are also expected to shift concurrently with temperature in many regions, yet our understanding of how thermal and hydration physiology jointly affect performance and fitness is still limited for most taxonomic groups. Here, we investigated the relationship between functional performance, hydration state and temperature in three ecologically distinct amphibians, and compare how temperature and water loss can concurrently limit activity under current climate conditions. We found that performance was maintained across a broad range of hydration states in all three species, but then declines abruptly after a threshold of 20–30% mass loss. This rapid performance decline was accelerated when individuals were exposed to warmer temperatures. Combining our empirical hydrothermal performance curves with species-specific biophysical models, we estimated that dehydration can increase restrictions on species' activity by up to 60% compared to restriction by temperature alone. These results illustrate the importance of integrating species' hydration physiology into forecasts of climate vulnerability, as omitting this axis may significantly underestimate the effects of future climate change on Earth's biological diversity.


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