Biologia futura最新文献

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.

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.

Measures of cardiac perceptual ability (also called cardiac accuracy) are methods of cardiac interoception, the perception of bodily sensation related to heart activity. This narrative review aims to provide an overview of these methods. We differentiate between three main measurement types: (1) change detection, i.e., when the task is to notice the change in the heart rate; also called: heart rate perception tasks, (2) discrimination tasks, i.e., when the task is to compare the internal sensations with external signal(s); also called: heartbeat detection tasks and (3) tracking tasks, i.e., when the task is to follow and report heartbeats via tapping or counting. We describe some of the new methods under "mixed methods," as they share features with more than one of the large measurement types described above. Specific measures differ in various aspects, such as their focus (heart rhythm vs. single beats), their sensitivity to non-conscious sensations and the calculated indices (e.g., whether significance level by hypothesis test is provided). When a measure of cardiac perceptual ability is chosen, it is advisable to take its characteristics into consideration in light of the planned research.

The classical aphasia literature has placed considerable emphasis on the language-centered understanding of aphasia and failed to consider the role of executive functions (EFs) regarding different aspects of patients' performance. Many current studies suggest deficits in EFs in individuals with aphasia, however, the available data is still limited. Here, our aim was to investigate the impairment of EFs and its potential negative effects on naming (slower performance, increased reaction time and/or decreased accuracy). We sought to determine whether the poor performance observed in word fluency task correlated with similar outcomes in naming. Our study involved five Hungarian post stroke aphasic patients (2 males and 3 females) between the ages of 60 and 70, as well as a control group matched for age and gender. The participants were diagnosed with different types of aphasia (global, Wernicke's, anomic and conduction). This study employed various neuropsychological and linguistic batteries. By comparing the patients' performance to that of the control group, we aimed to investigate the impacts of stroke. Within the aphasia group, we observed difficulties in following complex commands and a connection between general slowness and reduced accuracy in naming. We concluded that impairment of executive functions may have a negative impact on naming, comprehension, and fluency. Therefore, it is important to consider functional variations in neural networks, and to base our interpretations on the available psychophysiological data in literature. Our findings provide an alternative perspective to the traditional assessment of aphasia and highlight the importance of considering the role of executive functions.

Based on their characteristics, it is likely that mind-body techniques develop interoception, the perception of bodily state. Nevertheless, findings on mindfulness, meditation, yoga, and body scan techniques are inconclusive. Additionally, the methodological scope is not exhaustive, neither in terms of the intervention nor the applied measure of interoception. This study investigated for the first time the effect of regular yoga training on cardiac and gastric perceptual ability (measured with the mental heartbeat tracking task and the water load task, respectively). With the involvement of 90 female university students (yoga group n = 57, control group n = 33) we did not find any connection between baseline heartbeat perception score and gastric fullness. Moreover, the applied 10-week-long regular yoga training did not develop any of the measured interoceptive abilities. We conclude that yoga might develop other abilities than these specific sensations. Very probably, the measured cardiac and gastric perceptual abilities do not represent bodily sensations in general. It would be worth to investigate, however, the effect of longer yoga training on interoception.