Isochrony in barks of Cape fur seal (Arctocephalus pusillus pusillus) pups and adults.

Animal vocal communication often relies on call sequences. The temporal patterns of such sequences can be adjusted to other callers, follow complex rhythmic structures or exhibit a metronome-like pattern (i.e., isochronous). How regular are the temporal patterns in animal signals, and what influences their precision? If present, are rhythms already there early in ontogeny? Here, we describe an exploratory study of Cape fur seal (Arctocephalus pusillus pusillus) barks-a vocalisation type produced across many pinniped species in rhythmic, percussive bouts. This study is the first quantitative description of barking in Cape fur seal pups. We analysed the rhythmic structures of spontaneous barking bouts of pups and adult females from the breeding colony in Cape Cross, Namibia. Barks of adult females exhibited isochrony, that is they were produced at fairly regular points in time. Instead, intervals between pup barks were more variable, that is skipping a bark in the isochronous series occasionally. In both age classes, beat precision, that is how well the barks followed a perfect template, was worse when barking at higher rates. Differences could be explained by physiological factors, such as respiration or arousal. Whether, and how, isochrony develops in this species remains an open question. This study provides evidence towards a rhythmic production of barks in Cape fur seal pups and lays the groundwork for future studies to investigate the development of rhythm using multidimensional metrics.

Calls of the little auk (Alle alle) chicks reflect their behavioural contexts.

Animal vocalisations can often inform conspecifics about the behavioural context of production and the underlying affective states, hence revealing whether a situation should be approached or avoided. While this is particularly important for socially complex species, little is known about affective expression in wild colonial animals, and even less to about their young. We studied vocalisations of the little auk (Alle alle) chicks in the Hornsund breeding colony, Svalbard. Little auks are highly colonial seabirds, and adults convey complex behavioural contexts through their calls. We recorded chick calls during two contexts of opposite affective valence: handing by a human, and while they interact with their parents inside the nest. Using permuted discriminant function analysis and a series of linear mixed models, we examined the effect of the production context/associated affective valence on the acoustic parameters of those calls. Calls were reliably classified to their context, with over 97% accuracy. Calls uttered during handling had higher mean entropy, fundamental frequency, as well as lower spectral centre of gravity and a less steep spectral slope compared to calls produced during interactions with a parent inside the nest. The individuality of handling calls, assessed by information content, was lower than the individuality of calls uttered in the nest. These findings suggest that seabird chicks can effectively communicate behavioural/affective contexts through calls, conveying socially important messages early in development. Our results are mostly in line with emotional expression patterns observed across taxa, supporting their evolutionary continuity.

Social calls of the little auk (Alle alle) reflect body size and possibly partnership, but not sex.

Source-filter theory posits that an individual's size and vocal tract length are reflected in the parameters of their calls. In species that mate assortatively, this could result in vocal similarity. In the context of mate selection, this would mean that animals could listen in to find a partner that sounds-and therefore is-similar to them. We investigated the social calls of the little auk (Alle alle), a highly vocal seabird mating assortatively, using vocalizations produced inside 15 nests by known individuals. Source- and filter-related acoustic parameters were used in linear mixed models testing the possible impact of body size. A principal component analysis followed by a permuted discriminant function analysis tested the effect of sex. Additionally, randomization procedures tested whether partners are more vocally similar than random birds. There was a significant effect of size on the mean fundamental frequency of a simple call, but not on parameters of a multisyllable call with apparent formants. Neither sex nor partnership influenced the calls-there was, however, a tendency to match certain parameters between partners. This indicates that vocal cues are at best weak indicators of size, and other factors likely play a role in mate selection.

Seabird's cry: repertoire and vocal expression of contextual valence in the little auk (Alle alle).

Many seabird species breed in colonies counting up to hundreds of thousands of individuals. Life in such crowded colonies might require special coding-decoding systems to reliably convey information through acoustic cues. This can include, for example, developing complex vocal repertoires and adjusting the properties of their vocal signals to communicate behavioural contexts, and thus regulate social interactions with their conspecifics. We studied vocalisations produced by the little auk (Alle alle)-a highly vocal, colonial seabird-over mating and incubation periods on the SW coast of Svalbard. Using passive acoustic recordings registered in a breeding colony, we extracted eight vocalisation types: single call, clucking, classic call, low trill, short call, short-trill, terror, and handling vocalisation. Calls were grouped by production context (based on the typically associated behaviour), to which a valence (positive vs negative) was later attributed, when possible, according to fitness threats, i.e. predator or human presence (negative) and promoters, i.e. interaction with a partner (positive). The effect of the putative valence on eight selected frequency and duration variables was then investigated. The putative contextual valence significantly affected the acoustic properties of the calls. Calls assigned positive valence had higher fundamental frequency and spectral centre of gravity as well as shorter sound duration than these assigned negative valence. These results indicate that the little auk's vocal communication system may facilitate expression of complex behavioural contexts, and seems to include vocal plasticity within vocalisation types-however, more data are necessary to better understand this effect and possible interplays of other factors.

ANIMAL-SPOT enables animal-independent signal detection and classification using deep learning.

Bioacoustic research spans a wide range of biological questions and applications, relying on identification of target species or smaller acoustic units, such as distinct call types. However, manually identifying the signal of interest is time-intensive, error-prone, and becomes unfeasible with large data volumes. Therefore, machine-driven algorithms are increasingly applied to various bioacoustic signal identification challenges. Nevertheless, biologists still have major difficulties trying to transfer existing animal- and/or scenario-related machine learning approaches to their specific animal datasets and scientific questions. This study presents an animal-independent, open-source deep learning framework, along with a detailed user guide. Three signal identification tasks, commonly encountered in bioacoustics research, were investigated: (1) target signal vs. background noise detection, (2) species classification, and (3) call type categorization. ANIMAL-SPOT successfully segmented human-annotated target signals in data volumes representing 10 distinct animal species and 1 additional genus, resulting in a mean test accuracy of 97.9%, together with an average area under the ROC curve (AUC) of 95.9%, when predicting on unseen recordings. Moreover, an average segmentation accuracy and F1-score of 95.4% was achieved on the publicly available BirdVox-Full-Night data corpus. In addition, multi-class species and call type classification resulted in 96.6% and 92.7% accuracy on unseen test data, as well as 95.2% and 88.4% regarding previous animal-specific machine-based detection excerpts. Furthermore, an Unweighted Average Recall (UAR) of 89.3% outperformed the multi-species classification baseline system of the ComParE 2021 Primate Sub-Challenge. Besides animal independence, ANIMAL-SPOT does not rely on expert knowledge or special computing resources, thereby making deep-learning-based bioacoustic signal identification accessible to a broad audience.

Nordic walking with an integrated resistance shock absorber affects the femur strength and muscles torques in postmenopausal women.

Deterioration of the structure and function of the musculoskeletal system represents a significant problem during aging and intervention with a suitable load of physical activity may improve the quality of life. Nordic walking (NW) has become a popular and easily accessible form of activity, especially for older adults people around the world. Thus, the purpose of the study was to evaluate the influence of an Nordic walking training program with classic poles (NW) and with integrated resistance shock absorber (RSA) on bone mineral density and the peak torques of upper limb muscles and to compare the effects of both intervention programs. 25 women were randomly assigned to two training groups: 10 subjects using RSA (68 ± 4.19 years) and 15 subjects using NW poles (65 ± 3.40 years), which completed 8 weeks of training program. The hip, spine and forearm areal bone mineral density, torques of the flexors and extensors at the elbow and shoulder joints were measured before starting the training programs and after their completion. The most significant effect was found in differences between the two groups of women with respect to the femur strength index (p = 0.047) and the ratio of the flexors to extensors in the elbow (p = 0.049) and shoulder (p = 0.001) joints and peak torque of flexors in the shoulder joint (p = 0.001) for the left arm. A significant difference was also found in the index of torque asymmetry of flexors in the shoulder joint (p = 0.002). The study shows that Nordic walking with RSA poles for postmenopausal women led to beneficial changes in the femur strength index. However, we found no significant influence on bone mineral density values measured on the whole body, the femoral neck, forearm or lumbar spine regions. The occurrence of asymmetry in biomechanical muscle parameters, which was observed using RSA poles, may suggest the necessity of systematic controlling the gait technique to avoid the adverse consequences of asymmetrical rotation of the lumbar spine.

Influence of Nordic walking with poles with an integrated resistance shock absorber on carbohydrate and lipid metabolic indices and white blood cell subpopulations in postmenopausal women.

Background: Regular and individualised physical activities have been shown to prevent adverse changes associated with the aging process. The main purpose of this study was to evaluate changes in carbohydrate and lipid metabolism and white blood cell (WBC) subpopulations in postmenopausal women participating in Nordic walking (NW) training and to compare the use of poles with an integrated resistance shock absorber (RSA) with the use of classic poles. Materials & Methods: A total of 23 postmenopausal women participated in a 8-week programme of systematic physical activity between February and April. Before and after the training programme, somatic features and serum concentrations of 25-hydroxyvitamin D, glucose, and insulin, were assessed, as well as lipid profile and WBC count and its specific subpopulations. Results: Analysis of differences in somatic features and biochemical indices before and after training in the group of women who used RSA poles showed significant decreases in fat mass content (p < 0.05), insulin (p < 0.05), homeostatic model assessment of insulin resistance (p < 0.05), triglycerides (p < 0.05), total cholesterol (p < 0.05) and monocytes (p ≤ 0.01). In the group of women who used classic poles (NW), there was a significant decrease in WBC (p ≤ 0.01), lymphocytes (p < 0.05), monocytes (p ≤ 0.01) and granulocytes (p < 0.05). Conclusion: Increasing the training load through the use of RSA poles resulted in greater changes in carbohydrate and lipid metabolic indices compared to the use of classic NW poles. In turn, the more significant effect on WBC and its specific subpopulations count in the NW, compared to the RSA training programme, may indicate that specificity of training load is an important factor in modifying the immune system response.

Seasonal variation of 25-Hydroxyvitamin D and indices of carbohydrate and lipid metabolism in postmenopausal women.

BACKGROUND: Some studies indicate vitamin D's significant contribution to metabolic processess. Therefore, the purpose of this study was to evaluate the level of carbohydrate and lipid metabolism indices in relation to seasonal changes in 25-hydroxyvitamin D (25(OH)D) concentration in postmenopausal women. METHODS: Sixteen postmenopausal women meeting health criteria and not using vitamin D supplementation were included in the study. Seasonal variation of somatic features and the serum concentration of 25(OH)D, glucose, insulin, parathormon, sclerostin and lipid profile were determined on two terms (autumn-winter). RESULTS: Comparative analysis of the variables between the study terms revealed a marked decrease in the concentration of 25(OH)D (p ≤ 0.0001), insulin (p < 0.05), insulin resistance index (HOMA-IR), (p < 0.05). The significant positive correlations of changes (Δ) between autumn and winter in 25(OH)D with body mass (p < 0.05), and fat mass (p ≤ 0.01), measured in the first study term, in the group of women with normal body mass index (BMI), and negative correlation with fat mass (p < 0.05) in women with a BMI value above the reference values, were found. The relationship analysis showed that in women with normal BMI, the decrease in 25(OH)D concentrations was greater when the body fat percentage was higher, whereas in women with a BMI value above the reference values, the higher the fat percentage, the smaller was the decrease in 25(OH)D concentration. CONCLUSIONS: Seasonal changes in 25(OH)D concentration did not significantly affect the concentration of carbohydrate and lipid metabolism indices. The magnitude of decline in 25(OH)D levels depends on the fat mass. We suppose that environmental or lifestyle-related factors, e.g., nutritional behaviours, may have had more influence on metabolic indices than changes in 25(OH)D.

The diel pattern in harbour porpoise clicking behaviour is not a response to prey activity.

Wild harbour porpoises (Phocoena phocoena) mainly forage during the night and, because they rely on echolocation to detect their prey, this is also when they are most acoustically active. It has been hypothesised that this activity pattern is a response to the diel behaviour of their major prey species. To test this hypothesis, we monitored the acoustic activity of two captive harbour porpoises held in a net pen continuously during a full year and fed by their human keepers during daylight hours, thus removing the influence of prey activity. The porpoises were exposed to similar temperature and ambient light conditions as free-ranging animals living in the same region. Throughout the year, there was a pronounced diel pattern in acoustic activity of the porpoises, with significantly greater activity at night, and a clear peak around sunrise and sunset throughout the year. Clicking activity was not dependent on lunar illumination or water level. Because the porpoises in the pen are fed and trained during daylight hours, the results indicate that factors other than fish behaviour are strongly influencing the diel clicking behaviour pattern of the species.

Bone Mineral Density and Bone Turnover Markers in Postmenopausal Women Subjected to an Aqua Fitness Training Program.

The purpose of this study was to analyze the influence of aqua fitness training in deep water on bone tissue. The study was performed with 18 postmenopausal women separated into two groups: training and control groups. Before and after the training program, the hip and spine areal bone mineral density were measured along with the biochemical parameters of serum concentration of osteocalcin (OC) and C-terminal telopeptide of type I collagen (CTX). The most significant effect was found in differences between the two groups of women in terms of femur strength index (p < 0.05) during the period of the training program. The study demonstrated that an aqua fitness training program caused favorable changes in femur strength index in postmenopausal women, and this kind of exercise could be a useful form of physical activity for postmenopausal women.

Serum 25-hydroxyvitamin D concentrations and selected diet components in postmenopausal women.

BACKGROUND: Nutrition and lifestyle factors play an important role in the development and maintenance of peak bone mass and the prevention of bone degradation. The aim of the present study was to assess 25-hydroxy- cholecalciferol [25(OH)D] serum concentration in postmenopausal women during the winter period and the supply of selected components in their diet. METHODS: The study was conducted on a group of 35 women aged 54–77, using a question- naire, including a 24-hour recall related to a subject’s nutrient consumption. Serum concentrations of 25(OH) D were determined. Body composition was assessed with bioelectrical impedance analysis. RESULTS: Mean 25(OH)D serum concentration was found to be 61.2% of the minimum healthy level, according to the reference values. The supply of vitamin D and calcium covered 36.2% and 56.7% of RDA respectively. Correlation analysis has shown a significant inverse relationship between 25(OH)D serum con- centration and body fat (p < 0.05). CONCLUSIONS: The study indicates a decreased serum concentration of 25(OH)D in postmenopausal women during the winter period and a low supply of vitamin D and calcium in their diet. Nutrition education should be introduced to the adult population to prevent bone fractures.

Vitamin D, Iron Metabolism, and Diet in Alpinists During a 2-Week High-Altitude Climb.

A defensive mechanism against hypobaric hypoxia at high altitude is erythropoesis. Some authors point to the contribution of vitamin D to the regulation of this process. The aim of the present study was to assess the 25-hydroxycholecalciferol (25(OH)D) level and its associations with iron metabolic and inflammatory indices in participants of a 2-week mountaineering expedition. The study sample included 9 alpinists practicing recreational mountain climbing. Every 2 or 3 days they set up a different base between 3200 and 3616 m with the intention of climbing 4000 m peaks in the Mont Blanc massif. Before their departure for the mountains and 2 days after returning to the sea level anthropometric parameters, hematological parameters, serum levels of 25(OH)D and iron metabolic indices were measured in all the participants. The composition of the participants' diet was also evaluated. The comparative analysis showed a significant decrease in body mass, BMI values, total iron, and 25(OH)D concentrations (p<0.05). Also significant increases in unsaturated iron-binding capacity, hematocrit, and C-reactive protein concentrations (p<0.05) were found. It can be concluded that the 2-week climbing expedition contributed to the reduction of 25(OH)D levels and these changes were associated with modulation of immune processes. Moreover, the climbers' diet requires some serious modifications.

Soil nitrate leaching in silvopastures compared with open pasture and pine plantation.

Wide acceptance of silvopasture as an alternative sustainable agricultural system in the southeastern United States will depend on an improved understanding of the tree-forage interactions and recognition of its environmental benefits. The objective of this study was to evaluate differences in soil nitrate leaching in different land-use systems, in north Florida. An 18-yr-old loblolly pine (Pinus taeda L.) plantation was thinned in the summer of 2002 to create a fifth-row thinned, nontraditional intensive pine plantation (FO), silvopastures (HE = fourth-row conventionally thinned with random tree distribution and DO = double-row sets of trees with 15-m wide alleys), and an open pasture (PA). 'Argentine' bahiagrass (Paspalum notatum Flügge.) was established as understory vegetation in HE, DO, and PA. From 2004 to 2005 soil nitrate leaching was sampled and compared in the DO, HE, PA, and FO systems at 0.3 and 1.2 m depths after fertilizer application. Significant nitrate peaks were observed at 0.3 m depth after N fertilizer application in all systems. At the 1.2 m depth, the maximum nitrate concentrations were 67, 18, and 8 mg L(-1), in the forest plantation, open pasture, and both silvopastures, respectively. In general, reduced nitrate leaching at 1.2 m depth was observed in silvopastures compared with other land-used systems. These results are not intended to have a direct bearing on traditional pine plantation management, but rather support the potential role of silvopasture systems in reducing nitrate losses from the soil.