scholarly journals Are Bird Nests the Habitat for Ants? Implication from Ant Inventory (Hymenoptera: Formicidae) Across Various Bird Nests

2021 ◽  
Vol 748 (1) ◽  
pp. 012036
Author(s):  
Henny Herwina ◽  
Muhammad N. Janra ◽  
Fitri Anita ◽  
Mairawita ◽  
Yaherwandi

Abstract This study aimed to do the inventory on ant species (Hymenoptera: Formicidae) that specifically inhabit the bird nests within the Universitas Andalas campus complex, Limau Manis, Padang. It had been conducted from January to August 2018, where the bird nests were purposively collected then followed with ant collection from each nest. Forty nests were sampled and identified as nests of Estrildidae, Pycnonotidae, Sylviidae and from the unknown taxa; 5 nests showed active breeding indications when collected. A total of 2,741 ant individuals belong to 13 species, 12 genera, 8 tribes, and 4 subfamilies extracted from 31 (of which 4 were active nests), out of 40, observed nests. The ant species inventory included the members of subfamilies Formicinae (5), Myrmicinae (5), Dolichoderinae (2) and Pseudomyrmicinae (1). We statistically detected correlation between nest biomass and number of ant individual and species infested in the bird nests, which explained the more species recorded from Estrildid nests that were averagely bulkier than other nests. This result offers strong indication that bird nests may serve as form of habitat, or at least a niche, for ants.

2020 ◽  
Vol 16 (4) ◽  
pp. 291-300
Author(s):  
Zhenyu Gao ◽  
Yixing Li ◽  
Zhengxin Wang

AbstractThe recently concluded 2019 World Swimming Championships was another major swimming competition that witnessed some great progresses achieved by human athletes in many events. However, some world records created 10 years ago back in the era of high-tech swimsuits remained untouched. With the advancements in technical skills and training methods in the past decade, the inability to break those world records is a strong indication that records with the swimsuit bonus cannot reflect the real progressions achieved by human athletes in history. Many swimming professionals and enthusiasts are eager to know a measure of the real world records had the high-tech swimsuits never been allowed. This paper attempts to restore the real world records in Men’s swimming without high-tech swimsuits by integrating various advanced methods in probabilistic modeling and optimization. Through the modeling and separation of swimsuit bias, natural improvement, and athletes’ intrinsic performance, the result of this paper provides the optimal estimates and the 95% confidence intervals for the real world records. The proposed methodology can also be applied to a variety of similar studies with multi-factor considerations.


2021 ◽  
pp. 135245852110221
Author(s):  
Marco Vercellino ◽  
Stella Marasciulo ◽  
Silvia Grifoni ◽  
Elena Vallino-Costassa ◽  
Chiara Bosa ◽  
...  

Objectives: To investigate the extent of synaptic loss, and the contribution of gray matter (GM) inflammation and demyelination to synaptic loss, in multiple sclerosis (MS) brain tissue. Methods: This study was performed on two different post-mortem series of MS and control brains, including deep GM and cortical GM. MS brain samples had been specifically selected for the presence of active demyelinating GM lesions. Over 1,000,000 individual synapses were identified and counted using confocal microscopy, and further characterized as glutamatergic/GABAergic. Synaptic counts were also correlated with neuronal/axonal loss. Results: Important synaptic loss was observed in active demyelinating GM lesions (−58.9%), while in chronic inactive GM lesions, synaptic density was only mildly reduced compared to adjacent non-lesional gray matter (NLGM) (−12.6%). Synaptic loss equally affected glutamatergic and GABAergic synapses. Diffuse synaptic loss was observed in MS NLGM compared to control GM (−21.2% overall). Conclusion: This study provides evidence, in MS brain tissue, of acute synaptic damage/loss during active GM inflammatory demyelination and of synaptic reorganization in chronically demyelinated GM, affecting equally glutamatergic and GABAergic synapses. Furthermore, this study provides a strong indication of widespread synaptic loss in MS NLGM also independently from focal GM demyelination.


2021 ◽  
Author(s):  
Haider Z. Naqvi

Novel genetic enhancer screens were conducted targeting mutants involved in the guidance of axons of the DA and DB classes of motor neurons in C. elegans. These mutations are expected in genes that function in parallel to the unc-g/Netrin pathway. The screen was conducted in an unc-5(e53) genetic background and enhancers of the axon guidance defects caused by the absence of UNC-5 were identified. Three mutants were previously identified in the screen called rq1, rq2 and rq3 and two additional mutants called H2-4 and M1-3, were isolated in this study. In order to identify the gene affected by the rq1 mutation, wild-type copies of genes in the mapped rq1 mutation region were injected into the mutants to rescue the phenotypic defects. This is a strong indication that the gene of interest is a novel gene called H04D03.1. Promising results indicate that the H04D03.1 protein also works in germ-line apoptosis.


Author(s):  
Albert B. Kao ◽  
Amanda K. Hund ◽  
Fernando P. Santos ◽  
Jean-Gabriel Young ◽  
Deepak Bhat ◽  
...  

ABSTRACTFrom biofilms to whale pods, organisms have repeatedly converged on sociality as a strategy to improve individual fitness. Yet, it remains challenging to identify the most important drivers—and by extension, the evolutionary mechanisms—of sociality for particular species. Here, we present a conceptual framework, literature review, and model demonstrating that the direction and magnitude of the response of group size to sudden resource shifts provides a strong indication of the underlying drivers of sociality. We catalog six functionally distinct mechanisms related to the acquisition of resources, and we model these mechanisms’ effects on the survival of individuals foraging in groups. We find that whether, and to what degree, optimal group size increases, decreases, or remains constant when resource abundance declines depends strongly on the dominant mechanism. Existing empirical data support our model predictions, and we demonstrate how our framework can be used to predict the dominant social benefit for particular species. Together, our framework and results show that a single easily measurable characteristic, namely, group size under different resource abundances, can illuminate the potential drivers of sociality across the tree of life.


Author(s):  
Lucas Happ ◽  
Matthias Zimmermann ◽  
Maxim A Efremov

Abstract We study a heavy-heavy-light three-body system confined to one space dimension in the regime where an excited state in the heavy-light subsystems becomes weakly bound. The associated two-body system is characterized by (i) the structure of the weakly-bound excited heavy-light state and (ii) the presence of deeply-bound heavy-light states. The consequences of these aspects for the behavior of the three-body system are analyzed. We find a strong indication for universal behavior of both three-body binding energies and wave functions for different weakly-bound excited states in the heavy-light subsystems.


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