Five Years of Progress: A Summary of the Current Capabilities for Drone-Based Delivery of Rodenticide for Rodent Eradication Projects

Invasive rodent species represent a principal threat to global biodiversity and ecosystem integrity, particularly on islands. The development of aerial dispersal of rodenticide bait from helicopters in the 1990s was a major innovation credited with driving an increase in the scale, scope, and pace of successful eradication attempts. Helicopter-based operations can, however, be logistically complex and prohibitively costly, particularly on islands that are small and remote. Uncrewed aerial vehicles (or “drones”) have been identified as a promising tool to enable bait distribution on sites for which helicopter or ground-based methods are unfeasible. We report on the early evolution of this tool, documenting six drone-assisted rodent suppression and eradication programs widely spread across the Pacific. Drones were transportable on aircraft, cars, and small vessels, offering cost savings and logistical efficiency when compared with helicopters. They also proved to be a viable means of aerial bait dispersal: broadcasting 17,400 kg over an area of 796 ha across all programs. However, we encountered limitations associated with the technology in its current form. Flight plans initially took weeks to prepare, required detailed spatial data, and were not readily altered in real time during operations. The platforms we used were constrained by their lithium power source, needing extensive and time-consuming battery charging support and limiting payload capacity and endurance. Reliability issues, overcome in later projects, led to delays and abandonment of some parts of projects and necessitated the preparation and implementation of alternative methods as back-ups. Though key advancements − such as increased payload capacity and endurance − are imminent, a broad suite of improvements are needed for this method to be widely adopted. In their current form, drones provide a niche option for bait distribution on islands too large for hand-spreading of bait and where remoteness, precision, or safety considerations may limit the use of piloted aircraft. If future strategic investments in technology and people can be properly directed, drones have the potential to make the eradication of invasive rodent populations an achievable goal for a broader set of practitioners, democratizing a critically important conservation intervention

Ultrasound-guided perineural injection of the tibial nerve in the horse versus a ‘blind’ technique

Background: Tibial perineural analgesia has often been reported to fail to achieve nerve desensitisation in horses. Ultrasound-guided (US-guided) techniques have recently been described to improve tibial perineural desensitisation. Objectives: To compare US-guided and ‘blind’ tibial perineural analgesia techniques in lameness investigation. Study design: Randomised clinical trial. Methods: Horses presenting for lameness investigation, which required tibial perineural analgesia, were randomly assigned either to a US-guided or blind injection group. The efficacy of perineural analgesia was assessed by testing the loss of skin sensation at the medial and lateral heel bulbs. Skin sensation was assessed, prior to injection and then at four intervals post-injection (10–15, 20–25, 30–35 and 40–45 min) using a hand-held digital algometer with a 1 mm diameter pin; a value of 25 N was defined as indicative of skin desensitisation. The time taken to perform each injection technique and any adverse reactions were recorded. Summary statistics were performed to examine differences between groups. The frequency of skin desensitisation was compared between groups using a Fisher's exact test and the length of time taken to perform injections was compared using a Mann–Whitney U test. Results: Sixteen US-guided and 11 blind injections were included in the study. All cases undergoing US-guided injection lost skin sensation, whereas this occurred in only one case receiving the blind injection. The US-guided group had a significantly higher probability of skin sensation loss (p < 0.001), although the injection technique took significantly longer to complete compared to the blind group (p < 0.001). No adverse reactions were noted with either perineural injection technique. Main limitations: Limited number of cases for each injection group. Conclusions: These findings suggest that US-guided tibial perineural injection is more likely to result in adequate and prompt tibial perineural analgesia compared to the blind injection technique, although it takes longer to complete

Highly Efficient Visible Light Catalysts Driven by Ti3+-V-O-2Ti(4+)-N3- Defect Clusters

Local defect structures play significant roles on material properties, but they are seriously neglected in the design, synthesis, and development of highly efficient TiO2‐based visible light catalysts (VLCs). Here, we take anatase TiO2 nanocrystals that contain (Ti3+, N3−) ions and have the complicated chemical formula of (urn:x-wiley:2199692X:media:cnma201800400:cnma201800400-math-0001 )(urn:x-wiley:2199692X:media:cnma201800400:cnma201800400-math-0002 □z) as an example, and point out that the formation of Ti3+‐VO‐2Ti4+‐N3− local defect clusters is a key missing step for significantly enhancing VLC properties of host TiO2 nanocrystals. Experimental and theoretical investigations also demonstrate the emergent behaviors of these intentionally introduced defect clusters for developing highly efficient VLCs. This research thus not only provides highly efficient visible light catalysts for various practical applications but also addresses the significance of local defect structures on modifying material properties.Q. Sun, D. Cortie, T. J. Frankcome, N. Cox and Y. Liu acknowledge the supports of the Australian Research Council in the form of Discovery Projects and the ARC Future Fellowships program. S. Zhang and W. Shi thank the support from CAS (1A1111KYSB20180017, XDB17030000)

Three dimensional observations and modelling of intergranular stress corrosion cracking in austenitic stainless steel

Stress corrosion cracking is a life-limiting factor in many components of nuclear power plant in which failure of structural components presents a substantial hazard to both safety and economic performance. Uncertainties in the kinetics of short crack behaviour can have a strong influence on lifetime prediction, and arise due both to the complexity of the underlying mechanisms and to the difficulties of making experimental observations. This paper reports on an on-going research programme into the dynamics and morphology of intergranular stress corrosion cracking in austenitic stainless steels in simulated light water environments, which makes use of recent advances in high resolution X-ray microtomography. In particular in-situ, three dimensional X-ray tomographic images of intergranular stress corrosion crack nucleation and growth in sensitised austenitic stainless steel provide evidence for the development of crack bridging ligaments, caused by the resistance of non-sensitised special grain boundaries.In parallel a simple grain bridging model, introduced to quantify the effect of crack bridging on crack development, has been assessed for thermo-mechanically processed microstructures via statically loaded room temperature simulant solution tests and as well as high temperature/pressure autoclave studies. Thermo-mechanical treatments have been used to modify the grain size, grain boundary character and triple junction distributions, with a consequent effect on crack behaviour. Preliminary three-dimensional finite element models of intergranular crack propagation have been developed, with the aim of investigating the development of crack bridging and its effects on crack propagation and crack coalescence

A Steep Decline in the Galaxy Space Density Beyond Redshift 9 in the CANUCS UV Luminosity Function

We present a new sample of 158 galaxies at redshift $z>7.5$ selected from deep \jwst\ NIRCam imaging of five widely-separated sightlines in the CANUCS survey. Two-thirds of the pointings and 80\% of the galaxies are covered by 12 to 14 NIRCam filters, including seven to nine medium bands, providing accurate photometric redshifts and robustness against low redshift interlopers. A sample of 28 galaxies at $z>7.5$ with spectroscopic redshifts shows a low systematic offset and scatter in the difference between photometric and spectroscopic redshifts. We derive the galaxy UV luminosity function at redshifts 8 to 12, finding a slightly higher normalization than previously seen with \hst\ at redshifts 8 to 10. We observe a steeper decline in the galaxy space density from $z=8$ to $12$ than found by most \jwst\ Cycle 1 studies. In particular, we find only eight galaxies at $z>10$ and none at $z>12.5$, with no $z>10$ galaxies brighter than F277W AB=28 or $M_{\rm UV}=-20$ in our unmasked, delensed survey area of 53.4 square arcminutes. We attribute the lack of bright $z>10$ galaxies in CANUCS compared to GLASS and CEERS to intrinsic variance in the galaxy density along different sightlines. The evolution in the CANUCS luminosity function between $z=8$ and $12$ is comparable to that predicted by simulations that assume a standard star formation efficiency, without invoking any special adjustments.Comment: 30 pages, 12 figures, ApJ, in pres

Mice Deficient in T-bet Form Inducible NO Synthase-Positive Granulomas That Fail to Constrain Salmonella.

Clearance of intracellular infections caused by Salmonella Typhimurium (STm) requires IFN-γ and the Th1-associated transcription factor T-bet. Nevertheless, whereas IFN-γ-/- mice succumb rapidly to STm infections, T-bet-/- mice do not. In this study, we assess the anatomy of immune responses and the relationship with bacterial localization in the spleens and livers of STm-infected IFN-γ-/- and T-bet-/- mice. In IFN-γ-/- mice, there is deficient granuloma formation and inducible NO synthase (iNOS) induction, increased dissemination of bacteria throughout the organs, and rapid death. The provision of a source of IFN-γ reverses this, coincident with subsequent granuloma formation and substantially extends survival when compared with mice deficient in all sources of IFN-γ. T-bet-/- mice induce significant levels of IFN-γ- after challenge. Moreover, T-bet-/- mice have augmented IL-17 and neutrophil numbers, and neutralizing IL-17 reduces the neutrophilia but does not affect numbers of bacteria detected. Surprisingly, T-bet-/- mice exhibit surprisingly wild-type-like immune cell organization postinfection, including extensive iNOS+ granuloma formation. In wild-type mice, most bacteria are within iNOS+ granulomas, but in T-bet-/- mice, most bacteria are outside these sites. Therefore, Th1 cells act to restrict bacteria within IFN-γ-dependent iNOS+ granulomas and prevent dissemination

Differential Effects of Laparoscopic Sleeve Gastrectomy and Laparoscopic Gastric Bypass on Appetite, Circulating Acyl-ghrelin, Peptide YY3-36 and Active GLP-1 Levels in Non-diabetic Humans

Laparoscopic Roux-en-Y gastric bypass (LRYGBP) reduces appetite and induces significant and sustainable weight loss. Circulating gut hormones changes engendered by LRYGBP are implicated in mediating these beneficial effects. Laparoscopic sleeve gastrectomy (LSG) is advocated as an alternative to LRYGBP, with comparable short-term weight loss and metabolic outcomes. LRYGBP and LSG are anatomically distinct procedures causing differential entero-endocrine cell nutrient exposure and thus potentially different gut hormone changes. Studies reporting the comparative effects of LRYGBP and LSG on appetite and circulating gut hormones are controversial, with no data to date on the effects of LSG on circulating peptide YY3-36 (PYY3-36) levels, the specific PYY anorectic isoform. In this study, we prospectively investigated appetite and gut hormone changes in response to LRYGBP and LSG in adiposity-matched non-diabetic patients. Anthropometric indices, leptin, fasted and nutrient-stimulated acyl-ghrelin, active glucagon-like peptide-1 (GLP-1), PYY3-36 levels and appetite were determined pre-operatively and at 6 and 12 weeks post-operatively in obese, non-diabetic females, with ten undergoing LRYGBP and eight adiposity-matched females undergoing LSG. LRYGBP and LSG comparably reduced adiposity. LSG decreased fasting and post-prandial plasma acyl-ghrelin compared to pre-surgery and to LRYGBP. Nutrient-stimulated PYY3-36 and active GLP-1 concentrations increased post-operatively in both groups. However, LRYGBP induced greater, more sustained PYY3-36 and active GLP-1 increments compared to LSG. LRYGBP suppressed fasting hunger compared to LSG. A similar increase in post-prandial fullness was observed post-surgery following both procedures. LRYGBP and LSG produced comparable enhanced satiety and weight loss. However, LSG and LRYGBP differentially altered gut hormone profiles

Mosaic: A Satellite Constellation to Enable Groundbreaking Mars Climate System Science and Prepare for Human Exploration

The Martian climate system has been revealed to rival the complexity of Earth\u27s. Over the last 20 yr, a fragmented and incomplete picture has emerged of its structure and variability; we remain largely ignorant of many of the physical processes driving matter and energy flow between and within Mars\u27 diverse climate domains. Mars Orbiters for Surface, Atmosphere, and Ionosphere Connections (MOSAIC) is a constellation of ten platforms focused on understanding these climate connections, with orbits and instruments tailored to observe the Martian climate system from three complementary perspectives. First, low-circular near-polar Sun-synchronous orbits (a large mothership and three smallsats spaced in local time) enable vertical profiling of wind, aerosols, water, and temperature, as well as mapping of surface and subsurface ice. Second, elliptical orbits sampling all of Mars\u27 plasma regions enable multipoint measurements necessary to understand mass/energy transport and ion-driven escape, also enabling, with the polar orbiters, dense radio occultation coverage. Last, longitudinally spaced areostationary orbits enable synoptic views of the lower atmosphere necessary to understand global and mesoscale dynamics, global views of the hydrogen and oxygen exospheres, and upstream measurements of space weather conditions. MOSAIC will characterize climate system variability diurnally and seasonally, on meso-, regional, and global scales, targeting the shallow subsurface all the way out to the solar wind, making many first-of-their-kind measurements. Importantly, these measurements will also prepare for human exploration and habitation of Mars by providing water resource prospecting, operational forecasting of dust and radiation hazards, and ionospheric communication/positioning disruptions