88 research outputs found
Influence of environmental colors and long-term sex isolation on zebrafish shoaling behavior
Paper description: Zebrafish social behavior is mediated by different means of communication (chemical and visual). The potential influence of environmental coloring on the shoaling preference of Danio rerio has not been studied. Sex-related differences were found. Unlike females, male fish shoaled more with another male and less with a potential sexual partner. We did not find a significant influence of environmental coloring on social preference patterns. These results are an addition to the insufficient literature in this research area, which is generally characterized by underestimation of sex-related differences in the zebrafish social behavior. Abstract: Zebrafish has a complex social behavior and little is known about the role of sexual preference and their environmental social interactions. In this study we investigated the potential influence of environmental colors and shoaling preferences of zebrafish male and female populations, with a focus on visual communication. Males and females were kept for 7 days in gender-isolated tanks, with a specific habitat color for each group: green for males and red for females. After the pre-test period, all the animals were kept separated and 8 noninvasive behavioral tests were conducted in a T-maze, with the application of different visual stimuli. We did not observe any clear influence of environmental coloring on social zebrafish choices. Significant sex-related differences were found in shoaling partner preference (i.e. same sex vs. other sex, one fish vs. three fish) as follows: females showed a tendency to avoid other females and spent more time with males. Male fish did not display a preference between one or three fish stimuli and they shoaled more with another male and less with a potential sexual partner. There was an obvious difference between males and females in responses and selection of shoaling partners. https://doi.org/10.2298/ABS190118015L Received: January 18, 2019; Revised: February 23, 2019; Accepted: March 5, 2019; Published online: March 19, 2019 How to cite this article: Lenzi C, Grasso C, Nicoara M, Savuca A, Ciobica A, Plavan GI, Strungaru SA. Influence of environmental colors and long-term sex isolation on zebrafish shoaling behavior. Arch Biol Sci. 2019;71(2):329-37
Advanced Instrumentation of Frequency Modulation AFM for Subnanometer-Scale 2D/3D Measurements at Solid-Liquid Interfaces
Since the first demonstration of true atomic-resolution imaging by frequency modulation atomic force microscopy (FM-AFM) in liquid, the method has been used for imaging subnanometer-scale structures of various materials including minerals, biological systems and other organic molecules. Rencetly, there have been further advancements in theFM-AFMinstrumentation. Three-dimensional (3D) force measurement techniques are proposed for visualizing 3D hydration structures formed at a solid-liquid interface. Thesemethods further enabled to visualize 3D distributions of flexible surface structures at interfaces between soft materials andwater. Furthermore, the fundamental performance such as force sensitivity and operation speed have been significantly improved using a small cantilever and high-speed phase detector. These technical advancements enabled direct visualization of atomic-scale interfacial phenomena at 1 frame/s. In this chapter, these recent advancements in the FM-AFM instrumentation and their applications to the studies on various interfacial phenomena are presented. © Springer International Publishing Switzerland 201
Phenotypes Determined by Cluster Analysis and Their Survival in the Prospective European Scleroderma Trials and Research Cohort of Patients With Systemic Sclerosis
Objective: Systemic sclerosis (SSc) is a heterogeneous connective tissue disease that is typically subdivided into limited cutaneous SSc (lcSSc) and diffuse cutaneous SSc (dcSSc) depending on the extent of skin involvement. This subclassification may not capture the entire variability of clinical phenotypes. The European Scleroderma Trials and Research (EUSTAR) database includes data on a prospective cohort of SSc patients from 122 European referral centers. This study was undertaken to perform a cluster analysis of EUSTAR data to distinguish and characterize homogeneous phenotypes without any a priori assumptions, and to examine survival among the clusters obtained. /
Methods: A total of 11,318 patients were registered in the EUSTAR database, and 6,927 were included in the study. Twenty‐four clinical and serologic variables were used for clustering. /
Results: Clustering analyses provided a first delineation of 2 clusters showing moderate stability. In an exploratory attempt, we further characterized 6 homogeneous groups that differed with regard to their clinical features, autoantibody profile, and mortality. Some groups resembled usual dcSSc or lcSSc prototypes, but others exhibited unique features, such as a majority of lcSSc patients with a high rate of visceral damage and antitopoisomerase antibodies. Prognosis varied among groups and the presence of organ damage markedly impacted survival regardless of cutaneous involvement. /
Conclusion: Our findings suggest that restricting subsets of SSc patients to only those based on cutaneous involvement may not capture the complete heterogeneity of the disease. Organ damage and antibody profile should be taken into consideration when individuating homogeneous groups of patients with a distinct prognosis
Proceedings of the 24th Paediatric Rheumatology European Society Congress: Part three
From Springer Nature via Jisc Publications Router.Publication status: PublishedHistory: collection 2017-09, epub 2017-09-0
Study of Na
YbF3-doped and NaF co-doped calcium fluoride crystals were grown using the
Vertical Bridgman method. Transparent colorless crystals were obtained in graphite
crucible in vacuum (≈10-1 Pa) using a shaped graphite furnace. Room
temperature absorption spectra and dielectric spectra were measured to study the effect of
Na+ ions on the varieties of Yb3+ sites in CaF2 host.
The experimental results show that by co-doping with Na+ ions in different
Na:Yb ratios we can modulate the type of charge compensating defects of Yb3+
ions in CaF2 lattice. Dielectric relaxation in double doped (Yb, Na):CaF2 crystals-related with the study the charge compensating defects-was not reported before
Distribution of Ions in -Doped Crystals
Calcium fluoride crystals doped with various concentrations of have been grown using the Bridgman technique. The optical absorption spectra reveal the characteristic UV absorption bands of the ions. The distribution of the -ions along four crystals has been investigated using the optical absorption method. Taking into account the relationship between the optical absorption coefficient and the concentration of the impurities in the samples, the effective segregation coefficient of the ions has been calculated. Our study shows that the effective segregation coefficient of the ions in host depends on the dopant concentration, and varies between 0.85 and 1.15, for 0.5 mol% and 3 mol%-doped , respectively
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