Biologia futura最新文献

The taxonomic and metabolic diversity of prokaryotes and their adaptability to extreme environmental parameters have allowed extremophiles to find their optimal living conditions under extreme conditions for one or more environmental parameters. Natural habitats abundant in extremophilic microorganisms are relatively rare in Hungary. Nevertheless, alkaliphiles and halophiles can flourish in shallow alkaline lakes (soda pans) and saline (solonetz) soils, where extreme weather conditions favor the development of unique bacterial communities. In addition, the hot springs and thermal wells that supply spas and thermal baths and provide water for energy use are suitable colonization sites for thermophiles and hyperthermophiles. Polyextremophiles, adapted to multiple extreme circumstances, can be found in the aphotic, nutrient-poor and radioactive hypogenic caves of the Buda Thermal Karst, among others. The present article reviews the organization, taxonomic composition, and potential role of different extremophilic bacterial communities in local biogeochemical cycles, based on the most recent studies on extremophiles in Hungary.

A 2-year field experiment was performed to test lithium chloride, LiCl, application in a normal beekeeping management system. The effect of LiCl on bee larval mortality, beehive weight (honey production) and Varroa mite mortality were tested. Spectrometric quantification of Li on honey and the larval body were made to test the effectiveness of the presence of LiCl. Li was detected in bee larval bodies and in honey over 2 years, from 2018 to 2019. According to the results, no effect of LiCl on mite mortality or bee larval mortality was detected in the first year of application. By assessing the weight variation of beehives, only one LiCl-treated hive showed a significantly higher weight, whereas no other differences were detected between treatments and control. The same trend seen in 2018 was repeated in 2019, while a total bee larval mortality was observed after the first LiCl application, and still no differences in Varroa mite mortality were observed. According to these results, it was concluded that LiCl has no effect on Varroa mite mortality during normal beekeeping practice; furthermore, the recommended amount of treatment (25 mM) had a lethal effect (i.e., total mortality) on larvae following repeated applications.

Nowadays, the use of algae is prevalent for both industrial and agricultural purposes. The determination of chlorophyll (Chl) content is a commonly used method for estimating the phytoplankton abundance in different water bodies or biomass density of algal cultures. The aim of the present work is to optimise the efficiency of the Chl extraction from the green alga Tetradesmus obliquus using methanol as extracting solvent. The extraction efficiency was estimated by measuring the Chl a concentration of the extracts using fluorescence spectroscopy. To increase the extraction yield, glass fibre filters with algal cells on top were treated with 10% (v/v) formalin prior to the extraction. We found that this pretreatment significantly enhanced the extraction yield of Chl without its chemical decomposition. We also found that the optimal cell concentration for Chl determination ranged from 1.44 × 10⁴ to 3.60 × 10⁵ cells/mL and the extraction efficiency was lower when the cell density of the culture was out of this range. These results highlight the importance of the optimization of the pigment extraction for the studied algal species.

The outflow of the natural thermal Lake of Hévíz is habitat of several fish species, with conservation relevance. In the past few years, numerous thermophile (tropically originated) fishes were reported in this waterbody, from which two species Parachromis managuensis (Günther, 1867), Vieja melanurus (Günther, 1862) characterized with strong, self-sustaining population. The aim of our research was to provide basic population data and to study their individual growth. The standard length of jaguar cichlid ranged from 37 to 283 mm (mean SL = 110.21 ± 65.4 mm), the redhead cichlid standard length varied between 30 and 203 mm (mean SL = 93.91 ± 40.0 mm). Slightly positive allometry (b > 3) was found in the case of both species. The von Bertalanffy Growth Function can be described as the following L_t = 343.6[1 - e^{-0.196(t+0.973)}] in jaguar cichlid and L_t = 298.9[1 - e^{-0.113(t+0.997)}] in the case of redhead cichlid. The Bertalanffy growth equations show slow growth for both species. Fulton's condition factor (K) values varied between 1.376 and 2.11 (mean K = 1.701 ± 0.17) in the case of jaguar cichlid, and between 1.391 and 3.033 (mean K = 2.237 ± 0.24) for redhead cichlid. These baseline population biology data from the first known self-sustaining, temperate-zone populations of two tropical cichlids provide information e.g., for future ecological risk assessments or comparative growth analyzes.

R-loops, composed of DNA-RNA hybrids and displaced single-stranded DNA, are known to pose a severe threat to genome integrity. Therefore, extensive research has focused on identifying regulatory proteins involved in controlling R-loop levels. These proteins play critical roles in preventing R-loop accumulation and associated genome instability. Herein I summarize recent knowledge on R-loop regulators affecting R-loop homeostasis, involving a wide array of R-loop screening methods that have enabled their characterization, from forward genetic and siRNA-based screens to proximity labeling and machine learning. These approaches not only deepen our understanding on R-loop formation processes, but also hold promise to find new targets in R-loop dysregulation associated with human pathologies.

Tripartite motif (TRIM) family members participate in a variety of cellular activities, such as intracellular signaling, development, cellular death, protein quality control, immunological defense, waste degradation, and the emergence of cancer. These proteins usually act as E3 ubiquitin ligase. The final line of resistance against infectious viruses is a cytosolic ubiquitin ligase and antibody receptor called TRIM containing 21. TRIM21, a protein with a tripartite structure, has been linked to autoimmune erythematosus, Sjogren's disorder, and innate immunity. TRIM21 may either promote the formation of specific cancer-activating proteins, resulting in their proteasomal degradation, or it may do neither, depending on the kind of cancer and cancer-causing trigger. The current research has shown that the antiviral action of TRIM mostly depends on their role as E3-ubiquitin ligases and a significant portion of the TRIM family mediates the transmission of innate immune cell signals and the subsequent production of cytokines. We highlighted the function of TRIM family members in various inflammatory diseases.

Dogs trained with the Do as I Do method can imitate human actions upon request, but their ability to match actions observed from different perspectives remains unknown. The use of 2D video stimuli may enable researchers to systematically manipulate the perspective from which demonstrations are observed, thereby widening the range of methods available to study cognitive skills related to imitation. In this study, we explore the possibility of using 2D stimuli to test action matching in dogs, including when demonstrations are seen from different perspectives. We examined two dogs' imitative performance using videos projected on a screen; while, the owner interacted with the dog remotely through an online meeting software. The dogs were first trained to match human actions seen on a screen frontally, and then were tested when the projected demonstrations were seen frontally, from the side, and from above. Results revealed that both dogs matched the demonstrated actions from frontal and, notably, also from side perspectives, at least to some extent, consistent with familiarity of their daily interactions with humans. However, action matching from an above perspective presented challenges, indicating the potential influence of observational experience and highlighting the importance of perspective manipulation when investigating imitation abilities. These findings show that it is possible to use 2D videos to test imitation in dogs, thereby expanding the potential methodologies to study imitation and other related cognitive skills.

Forty-five years have passed since the first publication of the mismatch negativity (MMN) event-related brain potential (ERP) component. The first 10 years of research hardly gained any particular attention of the scientific community interested in acoustic perception. Debates on the nature of sensation versus perception were going on, and the technical possibilities to record ERPs, called in general evoked potentials, were very limited. Subtle changes in pure tone frequency or intensity giving rise to the MMN component were first investigated in humans. The background of the theoretical model developed by Risto Näätänen was the orientation reaction model of E.N. Sokolov published in 1963 so that the MMN was seen first as an electrophysiological correlate of auditory change detection. This fundamental ability of the auditory system seen as crucial for survival led to the development of the first animal model of the MMN (Csépe et al. in Clin Neurophysiol 66: 571–578, 1987). Indeed, it was confirmed that the MMN was the brain correlate of subtle changes detected that might alert to potential threats in the environment and direct the behavioral orientation. The investigations performed after 2000 introduced complex models and more sophisticated methods, both in animal and human studies, so that the MMN method was on the way to become a tool on the first place and not the main goal of research. This approach was further strengthened by the increasing number of studies on different clinical populations aiming at future applications. The aim of our review is to describe and redefine what the MMN may reflect in auditory perception and to show why and how this brain correlate of changes in the auditory scene can be used as a valuable tool in cognitive neuroscience research. We refer to publications selected to underly the argument the MMN cannot be classified anymore as a sign of simple change detection and not all the indicators used to confirm how genuine the MMN elicited by variations of tones are valid for those to speech contrasts. We provide a fresh view on the broadly used MMN models, provided by some influential publications as well as on the unwritten history of MMN research aiming to give revised picture on what the MMN may truly reflect. We show how the focus and terminology of the MMN research have changed and what kind of misunderstandings and seemingly contradictive results prevent the MMN community to accept a generally usable cognitive model.

Empirical studies on yoga have shown that regular practice can have a beneficial effect on risk factors of cardiovascular diseases; also, it can decrease body weight, body fat and increase muscle mass. Positive effects on balance and flexibility were also reported. This study evaluated the impact of a 3-month complex yoga-based program, including physical exercises, education, and social support, with a quasi-randomized design in a middle-aged community sample. The intervention group consisted of 46 participants while the passive control group was 29 participants. The intervention group showed a significant increase in core muscle strength and hamstring flexibility and a decrease in body  fat. No significant changes were found concerning risk factors of cardiovascular diseases, body weight, muscle mass, balancing ability, and dietary habits. A 3-month yoga intervention cannot substantially impact the cardiovascular system and body weight control in middle-aged adults.

Most studies on acute stress stem from works conducted under artificial laboratory conditions. Inducing stress for experimental scrutiny is problematic and can be unethical. In this study, a 'research methods' course's curriculum included a demonstration study testing anxiety and heart rate responses to the midterm test. Fifty-four university students (35 males and 19 females) presented a research topic in-person (n = 14) or prerecorded while being present (n = 40). Students selected a test format they could change until the week before the midterm test. The measures were trait anxiety, test anxiety, state anxiety, heart rate (HR), the last two being measured before and after examination, and grades. All students manifested decreased state anxiety and increased HR from before to after the test. Females exhibited higher HR and state anxiety than males. Real-time presentations were associated with higher HRs but not higher state anxiety. Those who changed their planned presentation mode from in-person to prerecorded exhibited higher test anxiety but not trait anxiety than those who presented as planned. Students who presented in-person obtained lower grades than those who prerecorded their presentations. Grades were negatively correlated with state anxiety after the test, but test anxiety did not significantly mediate the grades. Pre-test state anxiety was positively associated with both trait anxiety and test anxiety. The findings suggest that test anxiety is unlikely to affect grades, but test-anxious students need more control over academic evaluation. A choice in test format could be helpful in this regard.