Perceptual organization of auditory streaming-task relies on neural entrainment of the stimulus-presentation rate: MEG evidence

Background: Humans are able to extract regularities from complex auditory scenes in order to form perceptually meaningful elements. It has been shown previously that this process depends critically on both the temporal integration of the sensory input over time and the degree of frequency separation between concurrent sound sources. Our goal was to examine the relationship between these two aspects by means of magnetoencephalography (MEG). To achieve this aim, we combined time-frequency analysis on a sensor space level with source analysis. Our paradigm consisted of asymmetric ABA-tone triplets wherein the B-tones were presented temporally closer to the first A-tones, providing different tempi within the same sequence. Participants attended to the slowest B-rhythm whilst the frequency separation between tones was manipulated (0-, 2-, 4- and 10-semitones). Results: The results revealed that the asymmetric ABA-triplets spontaneously elicited periodic-sustained responses corresponding to the temporal distribution of the A-B and B-A tone intervals in all conditions. Moreover, when attending to the B-tones, the neural representations of the A- and B-streams were both detectable in the scenarios which allow perceptual streaming (2-, 4- and 10-semitones). Alongside this, the steady-state responses tuned to the presentation of the B-tones enhanced significantly with increase of the frequency separation between tones. However, the strength of the B-tones related steady-state responses dominated the strength of the A-tones responses in the 10-semitones condition. Conversely, the representation of the A-tones dominated the B-tones in the cases of 2- and 4-semitones conditions, in which a greater effort was required for completing the task. Additionally, the P1 evoked fields’ component following the B-tones increased in magnitude with the increase of inter-tonal frequency difference. Conclusions: The enhancement of the evoked fields in the source space, along with the B-tones related activity of the time-frequency results, likely reflect the selective enhancement of the attended B-stream. The results also suggested a dissimilar efficiency of the temporal integration of separate streams depending on the degree of frequency separation between the sounds. Overall, the present findings suggest that the neural effects of auditory streaming could be directly captured in the time-frequency spectrum at the sensor-space level.<br

Modulations of neural activity in auditory streaming caused by spectral and temporal alternation in subsequent stimuli: a magnetoencephalographic study

Background: The aim of the present study was to identify a specific neuronal correlate underlying the preattentive auditory stream segregation of subsequent sound patterns alternating in spectral or temporal cues. Fifteen participants with normal hearing were presented with series’ of two consecutive ABA auditory tone-triplet sequences, the initial triplets being the Adaptation sequence and the subsequent triplets being the Test sequence. In the first experiment, the frequency separation (delta-f) between A and B tones in the sequences was varied by 2, 4 and 10 semitones. In the second experiment, a constant delta-f of 6 semitones was maintained but the Inter-Stimulus Intervals (ISIs) between A and B tones were varied. Auditory evoked magnetic fields (AEFs) were recorded using magnetoencephalography (MEG). Participants watched a muted video of their choice and ignored the auditory stimuli. In a subsequent behavioral study both MEG experiments were replicated to provide information about the participants’ perceptual state. Results: MEG measurements showed a significant increase in the amplitude of the B-tone related P1 component of the AEFs as delta-f increased. This effect was seen predominantly in the left hemisphere. A significant increase in the amplitude of the N1 component was only obtained for a Test sequence delta-f of 10 semitones with a prior Adaptation sequence of 2 semitones. This effect was more pronounced in the right hemisphere. The additional behavioral data indicated an increased probability of two-stream perception for delta-f = 4 and delta-f = 10 semitones with a preceding Adaptation sequence of 2 semitones. However, neither the neural activity nor the perception of the successive streaming sequences were modulated when the ISIs were alternated. Conclusions: Our MEG experiment demonstrated differences in the behavior of P1 and N1 components during the automatic segregation of sounds when induced by an initial Adaptation sequence. The P1 component appeared enhanced in all Test-conditions and thus demonstrates the preceding context effect, whereas N1 was specifically modulated only by large delta-f Test sequences induced by a preceding small delta-f Adaptation sequence. These results suggest that P1 and N1 components represent at least partially-different systems that underlie the neural representation of auditory streaming

Magnetoencephalographic investigations of human primary auditory cortex responses to multiple amplitude modulated tones

Der zeitlichen Verläufe von Sprach- oder Musikklängen enthalten Amplitudenuktuationen mit unterschiedlichen Rhythmen die Träger der Information sind. Unsere Studie liefert wertvolle neue Erkenntnisse darüber, wie und in welcher Hirnregion komplexe Töne verarbeitet werden und mit anderen Komponenten des zentralen auditorischen Kortex interagieren. Die 40 Hz SSR hat sich dabei als wertvoller Parameter bei der Erforschung von Sprachverarbeitung und Störungen des zentralen Kortex erwiesen. Ein reiner Ton, mit zwei Sinusschwingungen von 38 und 40 Hz moduliert, wird wahrgenommen als eine 2 Hz Schwankung der Lautheit und eine Rauhigkeit, die den Modulationsfrequenzen bei 40 Hz entspricht. Korrespondierende SSRs bei 2, 38 und 40 Hz wurden mit dem MEG erfasst, das die Lokalisation überlappender Quellen im primären auditorischen Kortex ermöglichte. Der allgemeinere Fall mehrfacher AM Töne mit verschiedenen Trägerfrequenzen zeigte, dass die Antwort auf einen AM Ton unterdrückt wird, wenn ein zweiter AM Stimulus gleichzeitig dargeboten wird. Die Ergebnisse lassen eine zentrale Generierung der 40 Hz SSR annehmen

The Behaviour of Sheep around a Natural Waterway and Impact on Water Quality during Winter in New Zealand

Access of livestock, such as cattle, to waterways has been shown to be a cause of poor water quality due to pugging damage and excretion entering the water. In New Zealand, regulations require that cattle, deer, and pigs are excluded from accessing waterways, but there are no such requirements for sheep. The current study utilised 24 h video cameras, global positioning system units, and triaxial accelerometers to observe the interaction of Romney ewes (n = 40) with a natural waterway. Ewes were either restricted (week 1) or given access to a reticulated water trough (week 2). Proximity data showed that ewes spent more time within 3 m of the waterway when the trough was unrestricted than when restricted (14.1 ± 5.7 and 10.8 ± 5.1 min/ewe/day, respectively; p < 0.05). Ewes travelled shorter distances on the steeper areas of paddock than flatter areas. Similarly, ewes showed a spatial preference for the flat and low sloped areas of the paddock. Concentrations of suspended sediment and total phosphorus were higher during access to a reticulated water trough which coincided with the week with more rainy days. Phosphorus and E. coli concentrations in the stream water samples were the above recommended Australian and New Zealand Environment and Conservation Council water quality guidelines, especially after rainy days, but did not appear to be directly related to sheep activity. Overall, the results suggest that during winter, ewes interacted very little with the waterway and were thus unlikely to influence the levels of nutrient and pathogens in the waterway.fals

Longitudinal Study on the Effect of Season and Weather on the Behaviour of Domestic Cats (Felis catus)

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The Use of Triaxial Accelerometers and Machine Learning Algorithms for Behavioural Identification in Domestic Dogs (Canis familiaris): A Validation Study

Assessing the behaviour and physical attributes of domesticated dogs is critical for predicting the suitability of animals for companionship or specific roles such as hunting, military or service. Common methods of behavioural assessment can be time consuming, labour-intensive, and subject to bias, making large-scale and rapid implementation challenging. Objective, practical and time effective behaviour measures may be facilitated by remote and automated devices such as accelerometers. This study, therefore, aimed to validate the ActiGraph® accelerometer as a tool for behavioural classification. This study used a machine learning method that identified nine dog behaviours with an overall accuracy of 74% (range for each behaviour was 54 to 93%). In addition, overall body dynamic acceleration was found to be correlated with the amount of time spent exhibiting active behaviours (barking, locomotion, scratching, sniffing, and standing; R2 = 0.91, p < 0.001). Machine learning was an effective method to build a model to classify behaviours such as barking, defecating, drinking, eating, locomotion, resting-asleep, resting-alert, sniffing, and standing with high overall accuracy whilst maintaining a large behavioural repertoire.fals

Review and update of a Nutrient Transfer model used for estimating nitrous oxide emissions from complex grazed landscapes, and implications for nationwide accounting

In New Zealand, nitrous oxide emissions from grazed hill pastures are estimated using different emission factors for urine and dung deposited on different slope classes. Allocation of urine and dung to each slope class needs to consider the distribution of slope classes within a landscape and animal behavior. The Nutrient Transfer (NT) model has recently been incorporated into the New Zealand Agricultural GHG Inventory Model to account for the allocation of excretal nitrogen (N) to each slope class. In this study, the predictive ability of the transfer function within the NT model was explored using urine deposition datasets collected with urine sensor and GPS tracker technology. Data were collected from three paddocks that had areas in low (24°). The NT model showed a good overall predictive ability for two of the three datasets. However, if the urine emission factors (% of urine N emitted as N2 O-N) were to be further disaggregated to assess emissions from all three slope classes or slope gradients, more precise data would be required to accurately represent the range of landscapes found on farms. We have identified the need for more geospatial data on urine deposition and animal location for farms that are topographically out of the range used to develop the model. These new datasets would provide livestock urine deposition on a more continuous basis across slopes (as opposed to broad ranges), a unique opportunity to improve the performance of the NT model.fals

Spatial distribution of beef cattle on a New Zealand hill country farm: monitoring the use of streams and wet areas

Grazing livestock are an important source of contamination of freshwater, particularly when they have direct access to streams. Cattle in particular contribute to riparian habitat deterioration through stream bank destruction and direct defecation and urination in streams. Exclusion of stock or planting of riparian areas, are the most common catchment management methods used to protect waterways. Given the relatively low returns from beef and sheep farming, both of these strategies are very expensive and often logistically prohibitive in steep hill county landscapes. Despite this, policy trends indicate that fencing of streams in agricultural catchments may become mandatory in the future. It is important that we understand how much time cattle spend in and around hill country streams and wet areas (wetlands and hill side seeps), in order to quantify the likely environmental benefits from such policies. The current study examined cattle movement data obtained using Global Positioning System (GPS) collars from experiments undertaken at Massey University’s hill country research farm, Tuapaka, near Palmerston North, to investigate the amount of time cattle spent in and around streams and wet areas. Animal movement data were collected over seven grazing events, in three winter periods (2012, 2013 and 2015). Permanent streams and wet areas were identified using a digital elevation model derived from 1m LiDAR data, aerial RGB images and RTK measurements. Cattle spent 3.3 – 6% (48 – 86 min/day) of their day in streams and wet areas consistently across the 7 data collections. Cattle spent more time in streams and wet areas during the afternoon. There are differences in the median amount of time individual animals spend in non-risk areas. Further research is necessary to evaluate how we can influence the amount of time cattle spend in riparian areas on hill country and how stream bank behaviour varies at different times of the year

DINAMICA PIEȚEI FORȚEI DE MUNCĂ ÎN BULGARIA

BACKGROUND. Bulgaria, as many countries in the world is experiencing a critical period for the health workforce. The shortage of qualified nurses is one of the biggest obstacles for improving the health-system performance. Lack of strategic planning based on profound market research and elaboration of scientifically based prognosis further deteriorate the current nursing labor market disequilibrium. THE AIM of the study is to explore the main factors influencing the nursing market disequilibrium in Bulgaria and to make an evidence-based forecast of the future needs for nurses in order to suggest relevant workforce development strategies. MATERIAL AND METHODS. The study employs a combination of sociological and statistical methods. The analysis is based on the official statistical data on Bulgarian nursing personnel up to 2012. Primary information is collected through self-administered questionnaires distributed among 337 practicing nurses from April 2007 to December 2012. Data are processed with the packages MS Office Excel 2010 and SPSS v. 13. RESULTS. Results indicate that a decrease in the demand for nursing labour caused large staff layoffs during the first stage of the restructuring period (1990-2000) followed by a severe drop in the number of nurses due to emigration and exodus from the profession. There are also educational and qualification problems along with unattractiveness of the nursing practice due to high workload and low remuneration. With the mean age of 49 severe nursing workforce’s deficit is expected in 10-15 years due to retirement. According to our estimations the deficit of nurses will account for 3162 specialists by 2030. CONCLUSION. The Bulgarian nursing labor market disequilibrium is due to long-term structural imbalances. As the market mechanism is unable to attain equilibrium Bulgarian government should be urgently involved in workforce planning and initiate actions and strategies for producing and retaining the highly qualified nurse professionals in Bulgaria.   Key words: nursing workforce market, Bulgaria, disequilibrium, factors.  CONTEXT. Similar multor state, Bulgaria traversează, de asemenea, o perioadă critică &icirc;n ceea ce privește piața forței de muncă din sănătate. Lipsa de asistente medicale calificate este unul dintre cele mai mari obstacole pentru &icirc;mbunătățirea performanței sistemului de sănătate. Lipsa planificării strategice bazată pe cercetare amănunțită a pieței și lipsa prognozelor și proiecțiilor bazate pe argumente științifice conduc la dezechilibrul existent pe piața muncii asistentelor medicale, existent la momentul actual. SCOPUL studiului este de a explora factorii principali care influențează dezechilibrul de pe piața muncii asistentelor medicale &icirc;n Bulgaria și de a face prognoze, bazate pe dovezi, ale nevoilor viitoare de asistente medicale, &icirc;n scopul de a sugera strategii viitoare de dezvoltare a forței de muncă. MATERIAL ȘI METODE. Studiul&nbsp; de față abordează o combinație de metode sociologice și statistice.&nbsp; Analiza are la bază date statistice oficiale privind personalul medical din Bulgaria, date disponibile inclusiv pentru anul 2012. Informatiile primare au fost colectate cu ajutorul unor chestionare auto-administrate, distribuite unui număr de 337 asistente medicale practicante, &icirc;n perioada aprilie 2007 - decembrie 2012. Datele sunt prelucrate cu pachetele de analiză MS Office Excel 2010 și SPSS v. 13. REZULTATE. Rezultatele indică faptul că scăderea cererii pentru asistentele medicale a cauzat&nbsp; disponibilizările masive din timpul primei etape a perioadei de restructurare 1990-2000, urmată de o scădere severă a numărului de asistente medicale din cauza emigrării și exodul profesional. Există probleme educațiomale și de calificare, alături de lipsa de atractivitate a practicii de asistentă medicală din cauza volumului mare de muncă și a nivelului redus de salarizare. Cu o medie crescută a v&acirc;rstei asistentelor medicale, de 49 de ani,&nbsp; un deficit sever este așteptat &icirc;n următorii 10+15 ani, din cauza fenomenului de pensionare. Conform estimărilor noastre, deficitul de asistente medicale, p&acirc;nă &icirc;n anul 2030, va fi de 3162 de specialiști. CONCLUZII. Dezechilibrul numeric de asistente medicale de pe piața forței de muncă din sănătate este cauza unor dezechilibre structurale pe termen lung. Cum mecanismul piaței nu este &icirc;n măsură să rezolve acest dezechilibru, guvernul din Bulgaria va trebui urgent să&nbsp; se implice &icirc;n planificarea forței de muncă și să inițieze acțiuni și strategii de creare și menținere a asistentelor medicale calificate, &icirc;n Bulgaria. &nbsp;Cuvinte cheie: piața forței de muncă, asistente medicale, dezechilibru, factori frenatori, Bulgaria &nbsp