4,782 research outputs found
Cavity-enhanced Ramsey spectroscopy at a Rydberg-atom-superconducting-circuit interface
The coherent interaction of Rydberg helium atoms with microwave fields in a
superconducting coplanar waveguide resonator has been exploited to
probe the spectral characteristics of an individual resonator mode. This was
achieved by preparing the atoms in the 1s55sS Rydberg level by
resonance enhanced two-color two-photon excitation from the metastable
1s2sS level. The atoms then travelled over the resonator in which the
third harmonic microwave field, at a frequency of
GHz, drove the two-photon
1s55sS1s56sS transition. By injecting a sequence of
Ramsey pulses into the resonator, and monitoring the coherent evolution of the
Rydberg state population by state-selective pulsed electric field ionization as
the frequency of the microwave field was tuned, spectra were recorded that
allowed the resonator resonance frequency and quality factor to be determined
with the atoms acting as microscopic quantum sensors.Comment: 5 pages, 4 figure
Characterizing The Cellular, Molecular, And Behavioural Pathology Of Repetitive mTBI In A Human Tau Transgenic Mouse
After an episode of repetitive mild traumatic brain injury (rmTBI), many cellular and molecular cascades are initiated that result in the disruption of the structural and chemical integrity of the components in the brain, leading to the development of various cognitive deficits. The goal of this thesis was to evaluate a mouse model of concussion in order to study the relationship between rmTBI, GSK3β and tau phosphorylation, and behavioural outcomes in a transgenic mouse line expressing solely human tau. We found that there was increased phosphorylation of the two main regulatory sites on GSK3β, Tyr216 and Ser9, in the C57BL/6 mice. When investigating the pathology and behaviour in the MAPT KI mice, there was positive silver staining, pathological tau staining (AT8), and increased Iba1 staining compared to shams, with animals displaying cognitive deficits upon behavioural testing. Overall, this study supports the use of MAPT KI transgenic mice in rmTBI studies
Development of a novel Bluetooth Low Energy device for proximity and location monitoring in grazing sheep
Monitoring animal location and proximity can provide useful information on behaviour and activity, which can act as a health and welfare indicator. However, tools such as global navigation satellite systems (GNSS) can be costly, power hungry and often heavy, thus not viable for commercial uptake in small ruminant systems. Although, developments in Bluetooth Low Energy (BLE) could offer another option for animal monitoring, BLE signal strength can be variable, and further information is needed to understand the relationship between signal strength and distance in an outdoor environment and assess factors which might affect its interpretation in on-animal scenarios. A calibration of a purpose-built device containing a BLE reader, alongside commercial BLE beacons, was conducted in a field environment to explore how signal strength changed with distance and investigate whether this was affected by device height, and thus animal behaviour. From this calibration, distance prediction equations were developed whereby beacon distance from a reader could be estimated based on signal strength. BLE as a means of localisation was then trialled, firstly using a multilateration approach to locate 16 static beacons within an ∼5 400 m2 section of paddock using 6 BLE readers, followed by an on-sheep validation where two localisation approaches were trialled in the localisation of a weaned lamb within ∼1.4 ha of adjoining paddocks, surrounded by 9 BLE readers. Validation was conducted using one days’ worth of data from a lamb fitted with both a BLE beacon and separate GNSS device. The calibration showed a decline in signal strength with increasing beacon distance from a reader, with a reduced range and earlier decline in the proportion of beacons reported at lower reader and beacon heights. The distance prediction equations indicated a mean underestimation of 12.13 m within the static study, and mean underestimation of 1.59 m within the on-sheep validation. In the static beacon localisation study, the multilateration method produced a mean localisation error of 22.02 m, whilst in the on-sheep validation similar mean localisation errors were produced by both methods – 19.00 m using the midpoint and 23.77 m using the multilateration method. Our studies demonstrate the technical feasibility of localising sheep in an outdoor environment using BLE technology, however, potential commercial application of such a system would require improvements in BLE range and accuracy
Development of a novel Bluetooth Low Energy device for proximity and location monitoring in grazing sheep
Monitoring animal location and proximity can provide useful information on behaviour and activity, which can act as a health and welfare indicator. However, tools such as global navigation satellite systems (GNSS) can be costly, power hungry and often heavy, thus not viable for commercial uptake in small ruminant systems. Although, developments in Bluetooth Low Energy (BLE) could offer another option for animal monitoring, BLE signal strength can be variable, and further information is needed to understand the relationship between signal strength and distance in an outdoor environment and assess factors which might affect its interpretation in on-animal scenarios. A calibration of a purpose-built device containing a BLE reader, alongside commercial BLE beacons, was conducted in a field environment to explore how signal strength changed with distance and investigate whether this was affected by device height, and thus animal behaviour. From this calibration, distance prediction equations were developed whereby beacon distance from a reader could be estimated based on signal strength. BLE as a means of localisation was then trialled, firstly using a multilateration approach to locate 16 static beacons within an ∼5 400 m2 section of paddock using 6 BLE readers, followed by an on-sheep validation where two localisation approaches were trialled in the localisation of a weaned lamb within ∼1.4 ha of adjoining paddocks, surrounded by 9 BLE readers. Validation was conducted using one days’ worth of data from a lamb fitted with both a BLE beacon and separate GNSS device. The calibration showed a decline in signal strength with increasing beacon distance from a reader, with a reduced range and earlier decline in the proportion of beacons reported at lower reader and beacon heights. The distance prediction equations indicated a mean underestimation of 12.13 m within the static study, and mean underestimation of 1.59 m within the on-sheep validation. In the static beacon localisation study, the multilateration method produced a mean localisation error of 22.02 m, whilst in the on-sheep validation similar mean localisation errors were produced by both methods – 19.00 m using the midpoint and 23.77 m using the multilateration method. Our studies demonstrate the technical feasibility of localising sheep in an outdoor environment using BLE technology, however, potential commercial application of such a system would require improvements in BLE range and accuracy
Resource use and proximity technology in extensive systems - getting useful information on livestock at lower costs?
Resource use and proximity technology in extensive systems - getting useful information on livestock at lower costs?
Gene expression correlates of social evolution in coral reef butterflyfishes
Animals display remarkable variation in social behaviour. However, outside of rodents, little is known about the neural mechanisms of social variation, and whether they are shared across species and sexes, limiting our understand- ing of how sociality evolves. Using coral reef butterflyfishes, we examined gene expression correlates of social variation (i.e. pair bonding versus solitary living) within and between species and sexes. In several brain regions, we quantified gene expression of receptors important for social variation in mammals: oxytocin (OTR), arginine vasopressin (V1aR), dopamine (D1R, D2R) and mu-opioid (MOR). We found that social variation across individuals of the oval butterflyfish, Chaetodon lunulatus, is linked to differences in OTR, V1aR, D1R, D2R and MOR gene expression within several forebrain regions in a sexually dimorphic manner. However, this contrasted with social variation among six species representing a single evolutionary transition from pair- bonded to solitary living. Here, OTR expression within the supracommissural part of the ventral telencephalon was higher in pair-bonded than solitary species, specifically in males. These results contribute to the emerging idea that nonapeptide, dopamine and opioid signalling is a central theme to the evolution of sociality across individuals, although the precise mechanism may be flexible across sexes and species
PI3K Isoform-Specific Regulation of Leader and Follower Cell Function for Collective Migration and Proliferation in Response to Injury
To ensure proper wound healing it is important to elucidate the signaling cues that coordinate leader and follower cell behavior to promote collective migration and proliferation for wound healing in response to injury. Using an ex vivo post-cataract surgery wound healing model we investigated the role of class I phosphatidylinositol-3-kinase (PI3K) isoforms in this process. Our findings revealed a specific role for p110α signaling independent of Akt for promoting the collective migration and proliferation of the epithelium for wound closure. In addition, we found an important role for p110α signaling in orchestrating proper polarized cytoskeletal organization within both leader and wounded epithelial follower cells to coordinate their function for wound healing. p110α was necessary to signal the formation and persistence of vimentin rich-lamellipodia extensions by leader cells and the reorganization of actomyosin into stress fibers along the basal domains of the wounded lens epithelial follower cells for movement. Together, our study reveals a critical role for p110α in the collective migration of an epithelium in response to wounding
Mixed methods evaluation of targeted selective anthelmintic treatment by resource-poor smallholder goat farmers in Botswana
AbstractDue to the threat of anthelmintic resistance, livestock farmers worldwide are encouraged to selectively apply treatments against gastrointestinal nematodes (GINs). Targeted selective treatment (TST) of individual animals would be especially useful for smallholder farmers in low-income economies, where cost-effective and sustainable intervention strategies will improve livestock productivity and food security. Supporting research has focused mainly on refining technical indicators for treatment, and much less on factors influencing uptake and effectiveness. We used a mixed method approach, whereby qualitative and quantitative approaches are combined, to develop, implement and validate a TST system for GINs in small ruminants, most commonly goats, among smallholder farmers in the Makgadikgadi Pans region of Botswana, and to seek better understanding of system performance within a cultural context. After the first six months of the study, 42 out of 47 enrolled farmers were followed up; 52% had monitored their animals using the taught inspection criteria and 26% applied TST during this phase. Uptake level showed little correlation with farmer characteristics, such as literacy and size of farm. Herd health significantly improved in those herds where anthelmintic treatment was applied: anaemia, as assessed using the five-point FAMACHA© scale, was 0.44–0.69 points better (95% confidence interval) and body condition score was 0.18–0.36 points better (95% C.I., five-point scale) in treated compared with untreated herds. Only targeting individuals in greatest need led to similar health improvements compared to treating the entire herd, leading to dose savings ranging from 36% to 97%. This study demonstrates that TST against nematodes can be implemented effectively by resource-poor farmers using a community-led approach. The use of mixed methods provides a promising system to integrate technical and social aspects of TST programmes for maximum uptake and effect
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