rss_2.0Life Sciences FeedSciendo RSS Feed for Life Scienceshttps://www.sciendo.com/subject/LFhttps://www.sciendo.comLife Sciences Feedhttps://www.sciendo.com/subjectImages/Life_Sciences.jpg700700Contribution to the study of improving the aesthetics of the smile by repairing and reshaping the incisors with composite materials.https://sciendo.com/article/10.2478/asmj-2021-0004<abstract> <title style='display:none'>Abstract</title> <p>Introduction. Dental aesthetics, although it seems something relative and difficult to evaluate, it is governed by a series of laws and rules that connect the dental disciplines, creating a unitary whole. It is structured by rules, perfected by artistic sense and by the inclination towards beauty of all specialists in dento-facial cosmetics.</p> <p>The aim of the study is to highlight an overview of aesthetic factors to consider when restoring anterior teeth with direct composite materials.</p> <p>Material and methods. A total of 25 patients were included in the study where the anterior teeth were restored using Gradia Direct Anterior (from GC) and Filtek Z550 (from3M-ESPE) composite kits, in perfect isolation using rubber damn, with a separate appointment after 24 hours for the polishing step, for which Rainbow Kit Technic and polishing Platina Hi-Gloss (from Prevest) paste were used. While the replacement of the tooth defect, we ensured that the composite increment, which we used should not be more than 2mm in thickness, and light cured for 20 seconds as the producer recommends. In none of all tooth shape modification (elongation in incisal zone) we did not modify the occlusion, by eliminating all premature contacts. All patients included in the study have signed the informed consent and agreed to participate in this research.</p> <p>Results. From a total of 25 patients, we repaired 20 central incisors with the mesial (18 cases) or distal (2 cases) angles fractured, in different accidents, 5 cases with diastema by small shape of the crown or malposition of one of the central incisors.</p> <p>Conclusions. Restoring the incisal angle or the incisal edge and refining a natural and improved smile of the patient is e very frequent dental intervention, especially nowadays when aesthetics plays an important role in the social society.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Efficiency of different instruments used for composite filling polishing.https://sciendo.com/article/10.2478/asmj-2021-0005<abstract> <title style='display:none'>Abstract</title> <p>Introduction: Improper finishing and polishing of fillings leads to surface roughness of the restoration which leads to excessive plaque accumulation, gingival irritation, increased surface staining and poor aesthetics of restored teeth. Therefore, it is essential to use polishing instruments and pastes as a final step of simple caries treatment in order to achieve optimal long-time results. The aim of this study is to evaluate the efficiency of 4 different finishing and polishing instruments used for surface smoothening of aesthetic restorative materials in vitro. Materials and methods: 40 composite (Reality X) samples were prepared in vitro. Their surface irregularities were measured along 3 diagonals before and after polishing. Sof-Lex discs (3M Espe), rubber cones (Kenda), Arkansas stone (Fino) and polishing paste and a professional toothbrush (Kerr) were used for polishing. Each sample was polished under 5N pressure for 30 seconds at 3000 rpm. The surface roughness was than measured using a profilometer. Statistic analysis was performed using ANOVA and unpaired T-tests, the significance level was set at a value of p&lt;0.05. Results: Based on the mean values, the smallest roughness was found in the control group- 0.11, while the highest in the rubber polishers and Arkansas stone group- 0.47 and 0.48. The values for the Sof-Lex disc group and the polishing paste-toothbrush group were 0.40 and 0.39. Statistical analysis showed no significant differences between the four groups. Conclusion: It is mandatory to use polishing tools in order to obtain a smooth surface of the restoration and avoid the unwanted long-term complications. Polishing using brush and abrasive paste produced the smoothest surface of the composite.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Fear and dental anxiety in children: a study of the contributing factors.https://sciendo.com/article/10.2478/asmj-2021-0006<abstract> <title style='display:none'>Abstract</title> <p>Introduction: Dental fear and anxiety are an important issue affecting children’s oral health and clinical management, and also an insufficiently studied subject in dentistry.</p> <p>Aim of the study: The aim of this study was to better understand the child patient - dentist versus dentist - child patient relationship and study the dental fear and anxiety of children in order to improve the dental office practice. Material and methods: In this study a personalized questionnaire was created and applied on a number of 333 children, in 4 schools from Mures county, Romania, on girls and boys between the ages of 8 and 13. The questionnaires used emoticons alongside words in order to better determine the state of anxiety created by the dental appointment and everything that it entails. All data and results obtained were analyzed using Excel and Graph Pad Prism 5.0 software.</p> <p>Results: Out of 333 patients, 133 subjects (40%) were 8-10-year-old, 143 subjects (42.9%) 11 - 13 years and 57 subjects (17.1%) were over 14 years. 175 girls (52.6%) and 158 boys (47.4%) demonstrated their courage and desire in participating in our study. It was determined that fear of dental appointments was caused in children over 14 years of age. The state of relaxation is generally enjoyed by urban children (45%) and those aged 11-13 years (37.1%); the percentage of boys in this category is an interesting aspect (40.5%).</p> <p>Conclusion: Dental anxiety is multifactorial and is far more complex than can be explained by a single contributing factor. The direct involvement of the child from the perspective of maintaining dental health, leads to the elimination of the state of fear and anxiety. Regular visits to the dental office, on the initiative of the child patient itself can reduce the anguish.</p> </abstract>ARTICLE2021-06-12T00:00:00.000+00:00Petroleum in coastal seawater of Gdańsk Bayhttps://sciendo.com/article/10.1515/ohs-2015-0009<abstract> <title style='display:none'>Abstract</title> <p>The paper presents petroleum concentration in coastal waters of Gdańsk Bay, which was measured in 2006 - 2012. The oil concentration ranges from below the detection limit, i.e. 1 μg kg<sup>-1</sup> to almost 120 μg kg<sup>-1</sup>. The concentration does not usually exceed 60 μg kg<sup>-1</sup> and its average value is 11.7 μg kg<sup>-1</sup>. The presence of petroleum in coastal water is characterized by seasonality, with the lowest values in summer and the highest in winter. The conducted research showed that the coastal zone is not the source of petroleum contamination of the sea. The main reason for the presence of petroleum in the coastal water is the migration of polluted water within the bay. The inflow of pollutants from the mainland is yet another source of the contamination in the sea.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Influence of restoration methods on the longevity of changes in the thermal and oxygen dynamics of a degraded lakehttps://sciendo.com/article/10.1515/ohs-2015-0003<abstract> <title style='display:none'>Abstract</title> <p>The study was conducted on Lake Długie, located in the city of Olsztyn, which for 20 years received raw domestic sewage (400 m3 per day). After preliminary conservation operations, the lake was restored by artificial circulation and phosphorus inactivation methods. During artificial circulation, water temperature in the whole lake volume was equalized. The disconnection of the compressor stimulated the return to typical thermal parameters in the lake. Phosphorus inactivation did not affect the thermal regime in the lake. Artificial circulation caused an increase in the oxygen content in the whole lake, lowered the oxygen-depletion rate during stagnation, and shortened the duration of anaerobic conditions in the near-bottom waters. Phosphorus inactivation did not directly affect the content of oxygen. However, after the coagulant was added to the lake, the oxygenation of the water was further improved owing to the depressed photosynthesis caused by drastically reduced availability of phosphate for primary producers.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Anthropogenic impact on river basins: temporal evolution of sediment classes and accumulation rates in the northern Tyrrhenian Sea, Italyhttps://sciendo.com/article/10.1515/ohs-2015-0008<abstract> <title style='display:none'>Abstract</title> <p>In this study, sedimentological and geochronological data from sections of a core (GRT50) collected in the Northern Latium coastal area were compared to data on pluviometric (rainfall) trends, river flows and the temporal evolution of human interventions in the three most important hydrographic basins (Mignone, Marta and Fiora) of this coastal area. The statistical analysis of pluviometric trends identified variations due to a decreasing trend in the Fiora river basin, whereas in the two other locations the decrease was not so significant. Data from the sedimentological analysis of the core confirmed a progressive decrease in the sandy component, which declined from about 30% to the current level of 7% over the last 36 years. There was no significant variation in the sediment mass accumulation rates (MAR), which were characterized by an almost cyclic trend that was probably determined by the most intense floods in the study area. The results revealed that the variations caused by the fluvial processes have affected the water runoff of the Fiora River, and that the consequent decrease in the sand production has been responsible for the recession of beaches in the coastal area between Tarquinia and Montalto di Castro.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Cyanobacterial bloom intensity in the ecologically relevant state of lakes – an approach to Water Framework Directive implementationhttps://sciendo.com/article/10.1515/ohs-2015-0010<abstract> <title style='display:none'>Abstract</title> <p>This study focused on the determination of the cyanobacteria development in terms of the probabilistic recognition of the bloom intensity level in the ecologically relevant state of lakes. Assuming the possibility of using once-a-year sampling frequency, the ecological status or potential was assessed based on the modified Polish phytoplankton-based method (PMPL<sub>MOD</sub>) in 23 Masurian lakes. The summer cyanobacteria biomass reached 52.3 mg l<sup>-1</sup>. The biomass did not exceed the WHO-defined low risk threshold of 2 mg l<sup>-1</sup>, and was usually observed in lakes with at least good ecological status/potential. This threshold may be sufficient to propose it as a good/moderate cyanobacterial bloom intensity threshold. The average values of 3.3, 9.9 and 22.4 mg l<sup>-1</sup> were recorded in the lakes with a moderate, poor and bad ecological status/ potential, respectively. The WHO-defined moderate risk threshold of 10 mg l<sup>-1</sup> was exceeded only in lakes with a poor or bad ecological status/potential. The structure of cyanobacteria assemblages changed along with the deterioration of the ecological status/ potential and a decrease in Chroococcales biomass and an increase in Oscillatoriales and Nostocales biomass. Nevertheless, Planktolyngbya limnetica, Pseudanabaena limnetica and Aphanizomenon gracile had a significant presence in the total cyanobacterial biomass in all surveyed lakes.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Half a century of research on diatoms in athalassic habitats in central Polandhttps://sciendo.com/article/10.1515/ohs-2015-0006<abstract> <title style='display:none'>Abstract</title> <p>Part of the geology in the Łódź province was formed during the Upper Permian period when rich Zechstein salt was deposited. Groundwater drains the deposits and flows out in the village of Pełczyska, creating a unique hydrogeological site in Central Poland. An inland, athalassic ecosystem can be a reference site for halophile microflora. The outflow with surrounding marshes has been an algological research site since 1964.</p> <p>The research reveals changes recorded in diatom assemblages from athalassic habitats, characterized by a wide range of salinity levels, and verifies the tolerance of taxa to salinity. The comparative analysis was based on the diatom material sampled in 1964-1965, 1992-1994 and on recently collected samples.</p> <p>The analysis revealed the temporal change in assemblages caused by a change in the chloride concentration, and the spatial change from one to another habitat type, characterized by varying salinity levels. The halophilic species in the studied habitats included e.g. Halamphora dominici, H. tenerrima, Navicula digitoconvergens, N. meulemansii, Staurophora salina. The analysis of changes allowed the verification of the species’ requirements and tolerance range to the salinity factor. Therefore, in the case of Fragilaria famelica and Halamphora sydowii, we propose a change in the halobion system classification.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Diverse feeding ecology and habitat use in coral reef fishes in the Malaysian South China Sea, as revealed by liver fatty acid compositionhttps://sciendo.com/article/10.1515/ohs-2015-0012<abstract> <title style='display:none'>Abstract</title> <p>Fatty acid analysis was used to understand feeding ecology and habitat use of coral reef fishes in six families: Lutjanidae (Lutjanus lutjanus), Labridae (Thalassoma lunare), Nemipteridae (Scolopsis affinis, S. monogramma), Pomacentridae (Abudefduf bengalensis, A. sexfasciatus, A. viagiensis), Scaridae (Scarus quoyi, S. quoyi, S. rivulatus, S. ghobban) and Serrandae (Epinephelus fuscoguttatus, Cephalopholis cyanostigma, C. boenak) collected on the Bidong Island of the Malaysian South China Sea. The percentage of saturated fatty acids (ΣSAFA) ranged from 58.0% to 62.5%, with the highest values in fatty acids, the second highest percentage values were those of monounsaturated fatty acids (ΣMUFA) and they ranged from 25.7% to 38.9%, and the percentage of polyunsaturated fatty acids (ΣPUFA) had the lowest values, i.e. from 2.7% to 13.2%. ΣMUFA and ΣPUFA were significantly different between families, while ΣSAFA did not differ. These results indicate diverse feeding ecology and habitat use during the fish life history in relation to physiological condition, sexual development, and recent feeding events in the coral reef habitats in the Malaysian South China Sea. </p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Long-term changes in the dynamics and structure of cyanobacteria in Koronowo Reservoirhttps://sciendo.com/article/10.1515/ohs-2015-0013<abstract> <title style='display:none'>Abstract</title> <p>The Koronowo Reservoir (16.6 km<sup>2</sup>) is located in the lower reaches of the Brda River, in the Kujawy-Pomerania Province, 20 km from Bydgoszcz near the town of Koronowo, hence the name of the reservoir. The reservoir was built in the 1960s and started from damming the waters of the Brda River by a ca. 20 m high earth dam in the village of Pieczyska. This reservoir is used mainly for water retention and production of electric energy in the hydroelectric power station; in addition, it plays a significant recreational function. In terms of the latter function, the spread of cyanobacteria is a serious problem. The aim of the study was to assess longterm changes in the structure of cyanobacteria in waters of the Koronowo Reservoir. The results from 1996, 2008, 2011 and 2013 were compared. As evidenced by the analysis of the phytoplankton composition in the Koronowo Reservoir in terms of functional groups, especially the occurrence of dominant and subdominant species from the groups P, H<sub>1</sub>, S<sub>1</sub>, L<sub>M</sub>, J, G and W<sub>2</sub>, the waters of the reservoir can be classified as eutrophic, potentially evolving towards the hypertrophic conditions. The HPLC analysis of cyanobacterial toxins revealed the presence of microcystins at two sites of the water body. The species structure, the distribution and the dominance of specific species of cyanobacteria is recurrent over the 17 years; the following species form algal blooms: Aphanizomenon flos-aquae (L.) Ralfs et Bornet et Flahault and Microcystis aeruginosa (Kütz.) Kützing.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Distribution, diversity and some ecological characteristics of benthic amphipods in the Kapidağ Peninsula (Marmara Sea, Turkey)https://sciendo.com/article/10.1515/ohs-2015-0004<abstract> <title style='display:none'>Abstract</title> <p>The aim of this study was to determine the environmental factors affecting the fauna and the distribution of benthic amphipod species occurring on the Kapıdağ Peninsula, which is located in the south of the Marmara Sea. A total of 31 amphipod species were identified during the course of this study. In both seasons, Jassa marmorata (Holmes, 1905) and Protohyale schmidtii (Heller, 1866) were the most abundant species. During the study, temperature varied between 11.0 and 17.8°C, while salinity varied between 12.5 and 18.7 PSU; values of dissolved oxygen and pH ranged from 7.2 to 11.4 mg l-1 and 7.2 to 8.5 respectively at the coastal sites where hard bottom sampling was conducted. However, with regard to other sites where soft bottom sampling was carried out, the temperature varied between 8.0 and 18.0°C, salinity between 17.7 and 29.2 PSU, while values for dissolved oxygen and pH ranged from 5.1 to 11.4 mg l-1 and 7.8 to 8.7, respectively. In addition, the study of the amphipod species distribution revealed that the number of species was higher in spring compared to autumn while the number of individuals was higher in autumn compared to spring.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Contracaecum spp. from endemic Baikal fishes: the Baikal yellowfin Cottocomephorus grewingkii (Dybowski, 1874) and the longfin Baikal sculpin Cottocomephorus inermis (Yakovlev, 1890)https://sciendo.com/article/10.1515/ohs-2015-0007<abstract> <title style='display:none'>Abstract</title> <p>All the nematodes found in body cavities of the examined endemic Baikal fishes: 88 Baikal yellowfin Cottocomephorus grewingkii (Dybowski, 1874) and 35 longfin Baikal sculpin Cottocomephorus inermis (Yakovlev, 1890) were identified as Contracaecum osculatum baicalensis (Mozgovoi and Ryjikov, 1950) L3 larvae. The prevalence, mean intensity, intensity range and abundance of the nematodes in C. grewingkii were 37.5%, 2.55, 1-31, and 0.96, respectively, the corresponding values in C. inermis were 60.0%, 2.43, 1-10, and 1.46. The infestation level in C. grewingkii was significantly higher than in C. inermis (Mann-Whitney U-test, p&lt;0.02). The number of parasites was found to increase with the fish length. Although in both and C. inermis, the anisakids were more frequent in males (prevalence of 52.17 and 67.76%, respectively) than in females (prevalence of 35.39 and 42.86%, respectively), differences between the sexes in the infestation level in the two species were not significant (Mann-Whitney U-test, P= 0.09 and P=0.23, respectively). The molecular method applied (PCF-RFLP) allows to identify all the nematodes in both examined fish species as C. osculatum baicalensis.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Macrophyte biometric features as an indicator of the trophic status of small water bodieshttps://sciendo.com/article/10.1515/ohs-2015-0005<abstract> <title style='display:none'>Abstract</title> <p>The aim of the study was to determine whether biometric features of plants collected from single-species phytocoenoses developing in ponds can be used to describe habitat conditions of these water bodies. The biometric measurements were carried out in 148 field small water bodies at a total of 198 sites. The length of plants, their dry biomass, and volume of plant shoots were analyzed, converted to 1000 dm3 of water. The biometric measurements showed very large differences in individual parameters of different macrophyte species. The biggest differences were found in the length of elodeids and helophytes (from 1 cm to &gt; 900 cm), regardless of trophic conditions. Although the Polish flora is dominated by plants having a wide ecological range, there are species whose parameters correspond to specific habitat fertility. The highest biometric parameters were found for Ceratophyllum submersum, Sparganium erectum, Typha latifolia and Schoenoplectus lacustris in ponds characterized by increased trophic conditions. In contrast, Myriophyllum spp. alone showed a negative correlation with trophic state indices. The trophic effect on the studied parameters becomes more apparent for species with optima in fertile water bodies. The parameters of Ceratophyllum submersum can be considered as the trophic state index (TSI).</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Seasonal changes in phytoplankton and bioindices in the southern part of Lake Jeziorak (NE Poland)https://sciendo.com/article/10.1515/ohs-2015-0001<abstract> <title style='display:none'>Abstract</title> <p>The structure of phytoplankton communities of Lake Jeziorak was presented for the first time. The objective of our research was qualitative and quantitative analysis and bioindices of phytoplankton during and outside the tourist season. Analysis of phytoplankton assemblages were performed in 2011-2012. A total of 96 taxa were identified in Lake Jeziorak, mainly: Cyanobacteria - 20, Bacillariophyceae - 49, and Chlorophyta − 19. Biomass of the phytoplankton varied from 10 mg l−1 in October to 29 mg l−1 in May. In the whole research period, Cyanobacteria dominated and represented up to 68% of the total biomass. The cyanobacterial blooms were constantly observed. Biomass in the summer period was composed of filamentous Aphanizomenon gracile, Limnothrix redekei, Planktothrix agardhii and Pseudanabaena limnetica. Outside the holiday season, i.e. in autumn and spring, filamentous Cyanobacteria accompanied cryptomonads in phytoplankton. The species composition, the biomass of phytoplankton, and TSI indicate the hypertrophic conditions of the lake. Phytoplankton in Lake Jeziorak was in a state of equilibrium for almost the entire study period. S1 was a dominant group and its abundance and biomass did not change by more than 10%. There was no significant direct effect of the seasonal tourism impact on the development of phytoplankton in Lake Jeziorak.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Phytoplankton-based recovery requirement for urban lakes in the implementation of the Water Framework Directive’s ecological targetshttps://sciendo.com/article/10.1515/ohs-2015-0011<abstract> <title style='display:none'>Abstract</title> <p>This study focused on the determination of the phytoplankton-based recovery requirement, including bloom intensity thresholds in human-affected lakes, helpful in the restoration. The phytoplankton and physicochemical analyses were carried out on seven urban lakes in Kartuzy and Skępe. The Phytoplankton Metric for Polish Lakes was used to assess the ecological status and the Trophic Level Index was used to determine the trophic state. Only one lake had a good ecological status (meeting the WFD requirements for at least good status), whereas other lakes had poor or bad ecological status. All of them were eutrophic or hyper-eutrophic and the summer phytoplankton assemblages were dominated mainly by bloomforming cyanobacteria. The lowest phytoplankton bloom threshold of 2.6 mm<sup>3</sup> l<sup>-1</sup> (seasonal maximum) and the following thresholds of 5 mm<sup>3</sup> l<sup>-1</sup> for classes I/II; 8 mm<sup>3</sup> l<sup>-1</sup> for classes II/III; 21 mm<sup>3</sup> l<sup>-1</sup> for classes III/IV; 100 mm<sup>3</sup> l<sup>-1</sup> for classes IV/V were proposed for urban lakes. This could directly refer to the bloom intensity for high, good, moderate, poor and bad ecological status. This all indicates a huge recovery requirement in the majority of urban lakes, and the proposed bloom intensity classification may be helpful in fulfilling the WFD targets for the ecologicallyrelevant lake status.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00The three-spined stickleback (Gasterosteus aculeatus) infection with Schistocephalus solidus in Hel marina (Puck Bay, Baltic Sea, Poland)https://sciendo.com/article/10.1515/ohs-2015-0002<abstract> <title style='display:none'>Abstract</title> <p>Parasitic relations between animals are very common in wild nature. In this paper, we studied levels of infection in three-spined stickleback with plerocercoids of Schistocephalus solidus from Puck Bay (Baltic Sea, Poland). The total prevalence of infection was 54.2%, while proportion of infected individuals was significantly higher for females than for males. The body width was found to be significantly positively correlated with the number and the weight of parasites. In spite of the increasing deterioration of the Baltic Sea ecosystem by excessive eutrophication and hypoxia, lower prevalence of infection compared to previous published data indicates that there are likely other factors than pollution affecting the life cycle of parasites and the level of parasitism.</p> </abstract>ARTICLE2015-03-13T00:00:00.000+00:00Adoption of Good Agricultural Practice to Increase Yield and Profit of Ginger Farming in Nepalhttps://sciendo.com/article/10.2478/johr-2021-0009<abstract><title style='display:none'>Abstract</title><p>Ginger (<italic>Zingiber officinale</italic>) is one of the major high-value cash crops in Nepal. Low yield, conventional farming, and limited access to production resources such as improved cultivars, production technologies, and extension services are the existing problems of Nepali ginger farmers. In this study, we conducted community based-participatory research in Ilam district, Nepal, in 2015–2017. This research aimed to explore the appropriate ginger farming technology considering yield, income, and environment. We compared the effect of four different ginger production technologies on ginger yield and net farm income that include: i) traditional practice with mother rhizome harvest, ii) traditional practice without mother rhizome harvest, iii) good agricultural practice (GAP) with mother rhizome harvest, and iv) GAP without mother rhizome harvest. The experiment was conducted in a randomized complete block design with five replications. The yield of ginger under GAP and without mother rhizome harvest was observed 17.9 t·ha<sup>−1</sup>, which was 39.8% higher than the farmers’ existing practices and 45.5% higher than the national average. The cost of production was almost the same in all treatments; however, the GAP with mother rhizome-harvested treatment gave the highest benefit–cost ratio (1.5) along with the maximum net farm income ($2072.6·ha<sup>−1</sup>·year<sup>−1</sup>). Thus, we suggest ginger producers adopting GAP rules to obtain a higher yield and harvesting mother rhizomes earlier for obtaining maximum profit. The GAP rules will additionally protect the environment. This study also suggests policymakers and related stakeholders promoting GAP as a sustainable production technology in agriculture-based countries like Nepal.</p></abstract>ARTICLE2021-06-11T00:00:00.000+00:00Electrical impedance to easily discover undeclared freeze-thaw cycles in slaughtered bovine meathttps://sciendo.com/article/10.2478/joeb-2021-0002<abstract><title style='display:none'>Abstract</title><p>A portable electrical impedance spectroscopy device was developed to monitor the bioimpedance resistive component of bovine meat by injecting a sinusoidal current of 1 mA at 65 kHz. Both right and left longissimus dorsi muscles were trimmed from 4 slaughtered cows. The left muscle portions were frozen to −18 °C for 7 days while the right ones were meantime maintained at 5 °C. Mean value of impedance per length (Ω/cm) of frozen and thawed left samples was 31% lower than that of right non-frozen one (P = 0.0001). It was concluded that the device is reliable for monitoring the maturation of beef meat in situ with the possibility of revealing undeclared freeze-thaw cycles.</p></abstract>ARTICLE2021-03-30T00:00:00.000+00:00Segmental volume and circulatory changes that occur in humans and Rhesus monkeys during 4 hour, −6 degree head down tilthttps://sciendo.com/article/10.2478/joeb-2021-0003<abstract><title style='display:none'>Abstract</title><p>Nonhuman primates are often used to investigate physiologic processes that occur in man during aerospace/cardiovascular orthostatic research. Few studies have compared nonhuman primates and man under identical test conditions to assess the degree of similarity between the two species. Impedance plethysmography was used to measure calf, thigh, pelvic, thoracic, upper arm, and lower arm volume changes in eight rhesus (Macacca Mulatta) monkeys and twelve human subjects during four hour exposures to −6 degree head down tilt (HDT).</p></abstract>ARTICLE2021-04-17T00:00:00.000+00:00Electrical bioimpedance: from the past to the futurehttps://sciendo.com/article/10.2478/joeb-2021-0001<abstract><title style='display:none'>Abstract</title><p>This year, 2021, marks the “coming of age” for JoEB with its indexing in PubMed Central. It is also a century since some of the earliest studies on tissue impedance. This editorial briefly reviews the time-line of research in the field to mark this occasion.</p></abstract>ARTICLE2021-03-30T00:00:00.000+00:00en-us-1