1,659 research outputs found
Vocalization Influences Auditory Processing in Collicular Neurons of the CF-FM-Bat, Rhinolophus ferrumequinum
1. In awake Greater Horseshoe bats (Rhinolophus ferrumequinum) the responses of 64 inferior colliculus neurons to electrically elicited vocalizations (VOC) and combinations of these with simulated echoes (AS: pure tones and AS(FM): sinusoidally frequency-modulated tones mimicking echoes from wing beating insects) were recorded.
2. The neurons responding to the species-specific echolocation sound elicited by electrical stimulation of the central grey matter had best frequencies between 76 and 86 kHz. The response patterns to the invariable echolocation sound varied from unit to unit (Fig. 1).
3. In 26 neurons the responses to vocalized echolocation sounds markedly differed from those to identical artificial ones copying the CF-portion of the vocalized sound (AS). These neurons reacted with a different response to the same pure tone whether it was presented artificially or vocalized by the bat (Fig. 2). In these neurons vocalization activities qualitatively alter the responsiveness to the stimulus parameters of the echoes.
4. A few neurons neither responded to vocalization nor to an identical pure tone but discharged when vocalization and pure tone were presented simultaneously.
5. In 2 neurons synchronized encoding of small frequency-modulations of the pure tone (mimicking an echo returning from a wing beating prey) occurred only during vocalization. Without vocalization the neurons did not respond to the identical stimulus set (Fig. 3). In these neurons vocalization activities enhanced FM-encoding capabilities otherwise not present in these neurons.
6. FM-encoding depended on the timing between vocalization and frequency-modulated signal (echo). As soon as vocalization and FM-signal no more overlapped or at least 60–80 ms after onset of vocalization synchronized firing to the FM was lost (4 neurons) (Fig. 4).
7. 4 neurons weakly responded to playbacks of the bat's own vocalization 1 ms after onset of vocalization. But when the playback frequency was shifted to higher frequencies by more than 400 Hz the neurons changed firing patterns and the latency of the first response peak (Fig. 5). These neurons sensitive to frequency shifts in the echoes returning during vocalization may be relevant to the Doppler-shift compensation mechanism in Greater Horseshoe bats
Introductory comments for the scientific ethics theme.
In this letter, the three Guest Editors for JMBE's first-ever themed section introduce the topic of scientific ethics and decribe the organization of essays within the special section.\u
Levels of protein C and soluble thrombomodulin in critically ill patients with acute kidney injury: a multicenter prospective observational study.
Endothelial dysfunction contributes to the development of acute kidney injury (AKI) in animal models of ischemia reperfusion injury and sepsis. There are limited data on markers of endothelial dysfunction in human AKI. We hypothesized that Protein C (PC) and soluble thrombomodulin (sTM) levels could predict AKI. We conducted a multicenter prospective study in 80 patients to assess the relationship of PC and sTM levels to AKI, defined by the AKIN creatinine (AKI Scr) and urine output criteria (AKI UO). We measured marker levels for up to 10 days from intensive care unit admission. We used area under the curve (AUC) and time-dependent multivariable Cox proportional hazard model to predict AKI and logistic regression to predict mortality/non-renal recovery. Protein C and sTM were not different in patients with AKI UO only versus no AKI. On intensive care unit admission, as PC levels are usually lower with AKI Scr, the AUC to predict the absence of AKI was 0.63 (95%CI 0.44-0.78). The AUC using log10 sTM levels to predict AKI was 0.77 (95%CI 0.62-0.89), which predicted AKI Scr better than serum and urine neutrophil gelatinase-associated lipocalin (NGAL) and cystatin C, urine kidney injury molecule-1 and liver-fatty acid-binding protein. In multivariable models, PC and urine NGAL levels independently predicted AKI (p=0.04 and 0.02) and PC levels independently predicted mortality/non-renal recovery (p=0.04). In our study, PC and sTM levels can predict AKI Scr but are not modified during AKI UO alone. PC levels could independently predict mortality/non-renal recovery. Additional larger studies are needed to define the relationship between markers of endothelial dysfunction and AKI
Virtual Fencing Predictable for Cattle? A Simple Method to Test Whether and How Fast Cattle Can Learn the Association Between Acoustic Signal and Electric Pulse
Virtual fencing (VF) offers promising future prospects for improved grazing management as it has the potential to simplify fencing. VF lines are easily drawn and shifted via GPS coordinates. A VF collar emits an acoustic signal when the animal approaches the VF line. The signal stops immediately when the animal turns around. If the animal continues to move towards the VF line, a short electric pulse is emitted. A teaching and an operating mode are provided by the VF collars. The animals automatically change mode when they respond correctly to 20 consecutive acoustic signals without receiving an electric pulse. A prerequisite for using the technology is the ability of the grazing animal to learn to predict the electric pulse, therefore we used the time until mode change (from teaching to operating) to evaluate the learning ability and speed of 16 Fleckvieh heifers equally divided into two groups. All heifers were naive to VF prior to the study (conducted 05.07-16.07.2021). On the first day, the two groups were equipped with VF collars (® Nofence, AS, Batnfjordsøra Norway) and assigned to two adjacent pastures. On day eight, the collars were deactivated for a short time and then activated to start in teaching mode again to analyze differences in mode change speed when they were naive to the technology or experienced. The animals remained on the same pasture after reactivation of the collars. We investigated the time to reach theoperating mode (Δ) for each consecutive round (days one and eight) and found a significant difference (p \u3c 0.0001). Average Δ was 49.32 ± 0.41 h and 2.31± 0.41 h for round one and two, respectively. The faster mode change speed of the second round suggested successful learning. Given our study results, cattle learned to predict (and avoid) the electric pulse of VF collars
More Than a Fencing System? Testing the Validity of Virtual Fencing Collars for Animal Monitoring on Pasture
High labour requirements for fencing and animal monitoring appear to be general obstacles for the wider use of pastureland for grazing livestock. Virtual fencing (VF) enables a less laborious pasture management. Fence lines can be easily drawn and moved using GPS data. The advantages of VF for reducing the labour inherent to controlled grazing management are obvious. Potential additional animal monitoring opportunities arising from such a VF system that uses real-time GPS data have not yet been studied. Lying is seen as an indicator for assessing comfort or restlessness of cattle. Therefore, we focus on lying behavior in this evaluation. Based on data from conventional GPS collars, lying and standing often cannot be distinguished. The VF collars (® Nofence, AS, Batnfjordsøra Norway) used in this study detect low movement via an integrated accelerometer and then send the same GPS position during this time of low movement, in order to save battery life. We tested whether this battery life save function could be suitable for the detection of lying behavior. To address this question in a two-step-approach, we first compared observational data with IceTag pedometer (IceRobotics Ltd. Edinburgh, Scotland) data. In the second step, the pedometer data were compared to VF collar data via a confusion matrix. With 93% precision, 89% accuracy and 83% recall in this second step, the use of the VF collars can be recommended for a valid measure of lying behavior monitoring on pasture, which would be an added benefit to VF technology
Foraging behavior and Doppler shift compensation in echolocating hipposiderid bats, I-Iipposideros bicolor and I-Iipposideros speoris
1. Two hipposiderid bats,H. bicolor andH. speoris, were observed in their natural foraging areas in Madurai (South India). Both species hunt close together near the foliage of trees and bushes but they differ in fine structure of preferred hunting space:H. bicolor hunts within the foliage, especially whenH. speoris is active at the same time, whereasH. speoris never flies in dense vegetation but rather in the more open area (Fig. 1, Table 1).
2. Both species emit CF/FM-sounds containing only one harmonic component in almost all echolocation situations. The CF-parts of CF/FM-sounds are species specific within a band of 127–138 kHz forH. speoris and 147–159 kHz forH. bicolor (Tables 2 and 3).
3. H. speoris additionally uses a complex harmonic sound during obstacle avoidance and during laboratory tests for Doppler shift compensation.H. bicolor consistently emits CF/FM-sounds in these same situations (Fig. 2).
4. Both hipposiderid bats respond to Doppler shifts in the returning echoes by lowering the frequency of the emitted sounds (Fig. 3). However, Doppler compensations are incomplete as the emitted frequencies are decreased by only 55% and 56% (mean values) of the full frequency shifts byH. speoris andH, bicolor, respectively.
5. The differences in Doppler shift compensation, echolocating and hunting behavior suggest thatH. speoris is less specialized on echolocation with CF/FM-sounds thanH. bicolor
Rotational Stocking with Virtual Fences: Effects on Grassland Diet Digestibility, Livestock Performance and Stress Levels of Heifers
Virtual fencing is an innovative technology for simplified, less laborious dynamic grazing management and remote animal monitoring. The effect of this novel technology on animal welfare is still a matter of debate. Previous research suggests no differences in stress experience responses of cattle between the two fencing systems on continuously stocked pastures. This study investigated differences in diet organic matter digestibility, livestock performance and fecal cortisol metabolite concentrations of heifers on pastures in a rotational grazing system, fenced with a virtual fence (Nofence, Batnfjordsøra Norway) compared to heifers fenced with a traditional electric wire fence. The study was conducted in 8 weeks from July to September 2021 using 32 heifers divided into four groups allocated to the two fencing systems (two replicates). The experimental pasture of each group was subdivided into four paddocks for rotational grazing. Fecal samples were collected the first day and last day on pasture of each rotation period. Grassland herbage samples were taken by hand plucking pre- and post-grazing and analyzed using near infrared reflectance spectroscopy. Heifers were weighed prior to and after each rotation. The results suggest that no differences occur between the two fencing treatments with respect to diet digestibility, livestock performance or stress level, pointing at no trade-off to livestock performance or animal welfare when using virtual fencing
Immunohistochemical localization of fibronectin as a tool for the age determination of human skin wounds
We analyzed the distribution of fibronectin in routinely embedded tissue specimens from 53 skin wounds and 6 postmortem wounds. In postmortem wounds a faint but focal positive staining was exclusively found at the margin of the specimens which dit not extend into the adjacent stroma. Vital wounds were classified into 3 groups. The first comprising lesions with wound ages ranging from a few seconds to 30 min, the second comprising those with wound ages upt to 3 weeks, and the third group with lesions more than 3 weeks old. Ten out of 17 lesions with a wound age up to 30 min showed a clear positive reaction within the wound area. Three specimens in this group were completely negative, while in 4 additional cases the result was not significantly different from postmortem lesions. These 7 cases were characterized by acute death with extremely short survival times (only seconds). In wounds up to 3 weeks old fibronectin formed a distinct network containing an increasing number of inflammatory cells corresponding to the wound age. In 2 cases with a survival time of 17 days and in all wounds older than 3 weeks fibronectin was restricted to the surface of fibroblasts and to parallel arranged fibers in the granulation tissue without any network structures. We present evidence that fibronectin is a useful marker for vital wounds with a survival time of more than a few minutes. Fibronectin appears before neutrophilic granulocytes migrate into the wound area. Since a faint positive fibronectin staining is seen in postmortem lesions and bleedings, we propose that only those wounds which show strong positive fibronectin staining also extending into the adjacent stroma should be regarded as vital
Localization of tenascin in human skin wounds
A total of 56 surgically treated human skin wounds with a wound age between 8h and 7 months were investigated. Tenascin was visualized by immunohistochemistry and appeared first in the wound area pericellularly around fibroblastic cells approximately 2 days after wounding. A network-like interstitial positive staining pattern was first detectable in 3-day-old skin wounds. In all wounds with an age of 5 days or more, intensive reactivity for tenascin could be observed in the lesional area (dermal-epidermal junction, wound edge, areas of bleeding). In wounds with an age of more than approximately 1.5 months no positive staining occurred in the scar tissue. In conclusion, for forensic purposes, positive staining for tenascin restricted to the pericellular area of fibroblastic cells indicates a wound age of at least 2 days. Network-like structures appear after approximately 3 days or more. Since tenascin seems to be regularly detectable in skin wounds older than 5 days, the lack of a positive reaction in a sufficient number of specimens indicates a wound age of less than 5 days. The lack of a positive reaction in the granulation tissue of wounds with advanced wound age indicates a survival time of more than about 1.5 months, but a positive staining in older wounds cannot be excluded
- …