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The Arabian leopard Panthera pardus nimr is categorized as Critically Endangered, with < 200 individuals estimated to remain in the wild. Historically the species ranged over an extensive area of western Saudi Arabia but, with no confirmed sightings since 2014, investigating potential continued presence and distribution is of critical conservation importance. We present the results of a comprehensive survey designed to detect any remaining Arabian leopard populations in Saudi Arabia. We conducted 14 surveys, deploying 586 camera-trap stations at 13 sites, totalling 82,075 trap-nights. Questionnaire surveys were conducted with 843 members of local communities across the Arabian leopard's historical range to assess the presence of leopards, other predators and prey species. Predator scats were collected ad hoc by field teams and we used mitochondrial DNA analysis to identify the originating species. We obtained 62,948 independent photographs of animals and people, but none were of Arabian leopards. Other carnivores appeared widespread and domestic animals were numerous, but wild prey were comparatively scarce. Three questionnaire respondents reported sightings of leopards within the previous year, but targeted camera-trap surveys in these areas did not yield evidence of leopards. Of the 143 scats sent for analysis, no DNA was conclusively identified as that of the leopard. From this extensive study, we conclude there are probably no surviving, sustainable populations of Arabian leopards in Saudi Arabia. Individual leopards might be present but were not confirmed. Any future Arabian leopard conservation in Saudi Arabia will probably require reintroduction of captive-bred leopards.
Cirrus clouds are key modulators of Earth’s climate. Their dependencies on meteorological and aerosol conditions are among the largest uncertainties in global climate models. This work uses 3 years of satellite and reanalysis data to study the link between cirrus drivers and cloud properties. We use a gradient-boosted machine learning model and a long short-term memory network with an attention layer to predict the ice water content and ice crystal number concentration. The models show that meteorological and aerosol conditions can predict cirrus properties with R2 = 0.49. Feature attributions are calculated with SHapley Additive exPlanations to quantify the link between meteorological and aerosol conditions and cirrus properties. For instance, the minimum concentration of supermicron-sized dust particles required to cause a decrease in ice crystal number concentration predictions is 2 × 10−4 mg/m3. The last 15 hr before the observation predict all cirrus properties.
Applying the difference-in-difference (DID) estimation procedure, this study quantifies the wheat blast (Magnaporthe oryzae pathotype Triticum) induced losses in wheat yield, quantity of wheat sold, consumed, or stored, as well as wheat grain value in Bangladesh in 2016 following a disease outbreak that affected over 15,000 ha. Estimates show that the blast-induced yield loss was 540 kg ha−1 on average for households in blast-affected districts. Estimated total wheat production loss was approximately 8,205 tons worth USD 2.1 million in during the 2016 outbreak. Based on these insights, we discuss the need for long-term assured investment and concerted research efforts in controlling transboundary diseases such as wheat blast, including the importance of weather forecast driven early warning systems and the dissemination of blast-resistant varieties.
The coronavirus disease 2019 (COVID-19) pandemic has seen health systems adapt and change in response to local and international experiences. This study describes the experiences and learnings by the Central Adelaide Local Health Network (CALHN) in managing a campaign style, novel public health disaster response.
Disaster preparedness has focused on acute impact, mass casualty incidents. In early 2020, CALHNs largest hospital the Royal Adelaide Hospital (RAH) was appointed as the state primary COVID-19 adult receiving hospital. Between the period of February 1, 2020, when the first COVID-19 positive patient was admitted, through to December 31, 2020, the RAH had admitted 146 inpatients with COVID-19, 118 admitted to our hospital in the home service, 18 patients admitted to Intensive Care, and 4 patients died while inpatients. During this time CALHN has sustained an active (physical and virtual) Network Incident Command Centre (NICC) supported by a Network Incident Management Team (NIMT).
This study describes our key lessons learnt in relation to the management of a campaign style disaster response including the importance of disaster preparedness, fatigue management, and communication. Also described, were the challenges of operating in a command model and the role of exercising and education and an overview of our operating rhythm, how we built capability, and lessons management.
Undertaking a longer duration disaster response, relating to the COVID-19 pandemic has shown that, although traditional disaster principles still are important, there are many nuances that need to be considered to retain a proportionate response. Our key lessons have revolved around the key tenants of disaster management, communication, capability, and governance.
Heterogeneous roughness in the form of streamwise aligned strips is known to generate large scale secondary motions under turbulent flow conditions that can induce the intriguing feature of larger flow rates above rough than smooth surface parts. The hydrodynamical definition of a surface roughness includes a large scale separation between the roughness height and the boundary layer thickness which is directly related to the fact that the drag of a laminar flow is not altered by the presence of roughness. Existing simplified approaches for direct numerical simulation of roughness strips do not fulfil this requirement of an unmodified laminar base flow compared with a smooth wall reference. It is shown that disturbances induced in a modified laminar base flow can trigger large-scale motions with resemblance to turbulent secondary flow. We propose a simple roughness model that allows us to capture the particular features of turbulent secondary flow without impacting the laminar base flow. The roughness model is based on the prescription of a spanwise slip length, a quantity that can directly be translated into the Hama roughness function for a homogeneous rough surface. The heterogeneous application of the slip-length boundary condition results in very good agreement with existing experimental data in terms of the secondary flow topology. In addition, the proposed modelling approach allows us to quantitatively evaluate the drag increasing contribution of the secondary flow. Both the secondary flow itself and the related drag increase reveal a very small dependence on the gradient of the transition between rough and smooth surface parts only. Interestingly, the observed drag increase due to secondary flows above the modelled roughness is significantly smaller than the one previously reported for roughness resolving simulations. We hypothesise that this difference arises from the fact that roughness resolving simulations cannot truly fulfil the requirement of large scale separation.
Air dispersal of respiratory viruses other than SARS-CoV-2 has not been systematically reported. The incidence and factors associated with air dispersal of respiratory viruses are largely unknown.
We performed air sampling by collecting 72,000 L of air over 6 hours for pediatric and adolescent patients infected with parainfluenza virus 3 (PIF3), respiratory syncytial virus (RSV), rhinovirus, and adenovirus. The patients were singly or 2-patient cohort isolated in airborne infection isolation rooms (AIIRs) from December 3, 2021, to January 26, 2022. The viral load in nasopharyngeal aspirates (NPA) and air samples were measured. Factors associated with air dispersal were investigated and analyzed.
Of 20 singly isolated patients with median age of 30 months (range, 3 months–15 years), 7 (35%) had air dispersal of the viruses compatible with their NPA results. These included 4 (40%) of 10 PIF3-infected patients, 2 (66%) of 3 RSV-infected patients, and 1 (50%) of 2 adenovirus-infected patients. The mean viral load in their room air sample was 1.58×103 copies/mL. Compared with 13 patients (65%) without air dispersal, these 7 patients had a significantly higher mean viral load in their NPA specimens (6.15×107 copies/mL vs 1.61×105 copies/mL; P < .001). Another 14 patients were placed in cohorts as 7 pairs infected with the same virus (PIF3, 2 pairs; RSV, 3 pairs; rhinovirus, 1 pair; and adenovirus, 1 pair) in double-bed AIIRs, all of which had air dispersal. The mean room air viral load in 2-patient cohorts was significantly higher than in rooms of singly isolated patients (1.02×104 copies/mL vs 1.58×103 copies/mL; P = .020).
Air dispersal of common respiratory viruses may have infection prevention and public health implications.
Cardiovascular disease (CVD) is the most common non-communicable disease occurring globally. Although previous literature has provided useful insights into the important role that diet plays in CVD prevention and treatment, understanding the causal role of diets is a difficult task considering inherent and introduced weaknesses of observational (e.g. not properly addressing confounders and mediators) and experimental research designs (e.g. not appropriate or well designed). In this narrative review, we organised current evidence linking diet, as well as conventional and emerging physiological risk factors, with CVD risk, incidence and mortality in a series of diagrams. The diagrams presented can aid causal inference studies as they provide a visual representation of the types of studies underlying the associations between potential risk markers/factors for CVD. This may facilitate the selection of variables to be considered and the creation of analytical models. Evidence depicted in the diagrams was systematically collected from studies included in the British Nutrition Task Force report on diet and CVD and database searches, including Medline and Embase. Although several markers and disorders linked to conventional and emerging risk factors for CVD were identified, the causal link between many remains unknown. There is a need to address the multifactorial nature of CVD and the complex interplay between conventional and emerging risk factors with natural and built environments, while bringing the life course into the spotlight.
Studying phenotypic and genetic characteristics of age at onset (AAO) and polarity at onset (PAO) in bipolar disorder can provide new insights into disease pathology and facilitate the development of screening tools.
To examine the genetic architecture of AAO and PAO and their association with bipolar disorder disease characteristics.
Genome-wide association studies (GWASs) and polygenic score (PGS) analyses of AAO (n = 12 977) and PAO (n = 6773) were conducted in patients with bipolar disorder from 34 cohorts and a replication sample (n = 2237). The association of onset with disease characteristics was investigated in two of these cohorts.
Earlier AAO was associated with a higher probability of psychotic symptoms, suicidality, lower educational attainment, not living together and fewer episodes. Depressive onset correlated with suicidality and manic onset correlated with delusions and manic episodes. Systematic differences in AAO between cohorts and continents of origin were observed. This was also reflected in single-nucleotide variant-based heritability estimates, with higher heritabilities for stricter onset definitions. Increased PGS for autism spectrum disorder (β = −0.34 years, s.e. = 0.08), major depression (β = −0.34 years, s.e. = 0.08), schizophrenia (β = −0.39 years, s.e. = 0.08), and educational attainment (β = −0.31 years, s.e. = 0.08) were associated with an earlier AAO. The AAO GWAS identified one significant locus, but this finding did not replicate. Neither GWAS nor PGS analyses yielded significant associations with PAO.
AAO and PAO are associated with indicators of bipolar disorder severity. Individuals with an earlier onset show an increased polygenic liability for a broad spectrum of psychiatric traits. Systematic differences in AAO across cohorts, continents and phenotype definitions introduce significant heterogeneity, affecting analyses.
An experimental study of particle–vortex interactions has been undertaken in suspensions with volume fractions up to $\Phi =20\,\%$. Time-resolved particle image velocimetry measurements using a refractive index matching technique were performed to characterize the formation and evolution of vortex rings in both unconfined and confined configurations. It is shown that vortex rings in dense suspensions are more diffuse, which results in larger vortex cores and lower maximum vorticity. Furthermore, these vortex rings remain stable during their evolution, whereby the primary vortex breakdown and the formation of secondary vortices are inhibited. Although similar to vortex rings generated at lower Reynolds numbers in pure water, further results demonstrate that the vortex-ring circulation and non-dimensional vortex-core radius in dense suspensions remain higher than those in pure water at the same equivalent Reynolds number. Thus, the modification of vortex-ring behaviour in dense suspensions cannot be described solely through a variation in the effective viscosity. Finally, unlike in pure water, the confinement does not impact the non-dimensional vortex-core radius, vortex-ring circulation and maximum vorticity in dense suspensions. This unusual result demonstrates that the dynamics of vortex rings in dense suspensions are strongly insensitive to the effect of confinement.
This paper reports the recent development of a full-scale particle-in-cell (PIC) simulation package highlighting an efficient electro-statics (ES)-PIC implementation for spacecraft charging problems. Numerical simulations are crucial in studying plasma flows because analytical solutions are rare, and experiments are expensive. There are many types of plasma flow that need various numerical methods for efficient and accurate simulations; as such, how to implement and organize those different methods into one comprehensive simulation package is challenging. This work adopted several modern software design patterns and developed a versatile package that includes various PIC schemes. This package has an open architecture, clean interfaces with both serial and parallel simulation capabilities. Two benchmark test cases are included to demonstrate the capabilities of this package. Then two plasma flows around a positively charged probe are simulated, and the results are discussed. The simulation results are consistent with past simulation results, and new insights are obtained. This work can lead to the development and organization of more sophisticated plasma simulation solvers in the future.
Drawing upon new evidence emerging from Kenya's Cherangani Hills, this research project furthers current understanding of the archaeology of Late Iron Age forest-dwelling communities in East Africa, focusing on a series of intriguing earthworks deep inside forest environments that are reminiscent of the ‘Sirikwa’ tradition.
Freshwater habitats in China are potentially suitable for invasive alien turtle species and, consequently, raising turtles in aquaculture facilities and the trade in turtles this supplies pose risks to habitats and native wetland communities when exotic turtles escape or are released deliberately. Online trade (e-commerce) is making an increasing contribution to turtle sales in China, seemingly driving demand and thus potentially exacerbating the risk of release. We document the scale and spatial pattern of online sales of non-native turtles over 90 days on China's Taobao.com e-commerce site. The majority of sales were in the ecologically sensitive middle and lower Yangtze river basin (82.35% of > 840,000 slider turtles Trachemys scripta elegans, and 68.26% of > 100,000 snapping turtles, Chelydridae spp.). These species are native to the Americas. Concurrently, over 2008–2018, we found 104 mentions of feral turtle issues listed on Baidu News where, among the 53 prefectures mentioned, issues with invasive turtle populations also focused predominantly in the middle and lower Yangtze river basin. Although circumstantial, this association suggests that the substantial online sale of alien turtles could be having detrimental effects in China's Yangtze river basin. It is important to safeguard these wetland habitats, which are of global importance, by improving policies for detecting and regulating invasive alien turtle issues and by warning consumers about the ecological hazard of their purchases.
Wildlife is an essential component of all ecosystems. Most places in the globe do not have local, timely information on which species are present or how their populations are changing. With the arrival of new technologies, camera traps have become a popular way to collect wildlife data. However, data collection has increased at a much faster rate than the development of tools to manage, process and analyse these data. Without these tools, wildlife managers and other stakeholders have little information to effectively manage, understand and monitor wildlife populations. We identify four barriers that are hindering the widespread use of camera trap data for conservation. We propose specific solutions to remove these barriers integrated in a modern technology platform called Wildlife Insights. We present an architecture for this platform and describe its main components. We recognize and discuss the potential risks of publishing shared biodiversity data and a framework to mitigate those risks. Finally, we discuss a strategy to ensure platforms like Wildlife Insights are sustainable and have an enduring impact on the conservation of wildlife.
The initial classic Fontan utilising a direct right atrial appendage to pulmonary artery anastomosis led to numerous complications. Adults with such complications may benefit from conversion to a total cavo-pulmonary connection, the current standard palliation for children with univentricular hearts.
A single institution, retrospective chart review was conducted for all Fontan conversion procedures performed from July, 1999 through January, 2017. Variables analysed included age, sex, reason for Fontan conversion, age at Fontan conversion, and early mortality or heart transplant within 1 year after Fontan conversion.
A total of 41 Fontan conversion patients were identified. Average age at Fontan conversion was 24.5 ± 9.2 years. Dominant left ventricular physiology was present in 37/41 (90.2%) patients. Right-sided heart failure occurred in 39/41 (95.1%) patients and right atrial dilation was present in 33/41 (80.5%) patients. The most common causes for Fontan conversion included atrial arrhythmia in 37/41 (90.2%), NYHA class II HF or greater in 31/41 (75.6%), ventricular dysfunction in 23/41 (56.1%), and cirrhosis or fibrosis in 7/41 (17.1%) patients. Median post-surgical follow-up was 6.2 ± 4.9 years. Survival rates at 30 days, 1 year, and greater than 1-year post-Fontan conversion were 95.1, 92.7, and 87.8%, respectively. Two patients underwent heart transplant: the first within 1 year of Fontan conversion for heart failure and the second at 5.3 years for liver failure.
Fontan conversion should be considered early when atrial arrhythmias become common rather than waiting for severe heart failure to ensue, and Fontan conversion can be accomplished with an acceptable risk profile.
Anthropogenic habitat alteration and invasive species are threatening carnivores globally. Understanding the impact of these factors is critical for creating localized, effective conservation programmes. Madagascar's Eupleridae have been described as the least studied and most threatened group of carnivores. We investigated the effects of habitat degradation and the presence of people and exotic species on the modelled occupancy of the endemic fosa Cryptoprocta ferox, conducting camera-trap surveys in two western deciduous forests, Ankarafantsika National Park and Andranomena Special Reserve. Our results indicated no clear patterns between habitat degradation and fosa occupancy but a strong negative association between cats Felis sp. and fosas. Cat occupancy was negatively associated with birds and positively associated with contiguous forest and narrow trails. In contrast, dog Canis lupus familiaris occupancy was best predicted by wide trails, degraded forest and exotic civets. Our results suggest fosas are capable of traversing degraded landscapes and, in the short term, are resilient to contiguous forest disturbance. However, high occupancy of cats and dogs in the landscape leads to resource competition through prey exploitation and interference, increasing the risk of transmission of potentially fatal diseases. Management strategies for exotic carnivores should be considered, to reduce the widespread predation of endemic species and the transmission of disease.
We reviewed all patients who were supported with extracorporeal membrane oxygenation and/or ventricular assist device at our institution in order to describe diagnostic characteristics and assess mortality.
A retrospective cohort study was performed including all patients supported with extracorporeal membrane oxygenation and/or ventricular assist device from our first case (8 October, 1998) through 25 July, 2016. The primary outcome of interest was mortality, which was modelled by the Kaplan–Meier method.
A total of 223 patients underwent 241 extracorporeal membrane oxygenation runs. Median support time was 4.0 days, ranging from 0.04 to 55.8 days, with a mean of 6.4±7.0 days. Mean (±SD) age at initiation was 727.4 days (±146.9 days). Indications for extracorporeal membrane oxygenation were stratified by primary indication: cardiac extracorporeal membrane oxygenation (n=175; 72.6%) or respiratory extracorporeal membrane oxygenation (n=66; 27.4%). The most frequent diagnosis for cardiac extracorporeal membrane oxygenation patients was hypoplastic left heart syndrome or hypoplastic left heart syndrome-related malformation (n=55 patients with HLHS who underwent 64 extracorporeal membrane oxygenation runs). For respiratory extracorporeal membrane oxygenation, the most frequent diagnosis was congenital diaphragmatic hernia (n=22). A total of 24 patients underwent 26 ventricular assist device runs. Median support time was 7 days, ranging from 0 to 75 days, with a mean of 15.3±18.8 days. Mean age at initiation of ventricular assist device was 2530.8±660.2 days (6.93±1.81 years). Cardiomyopathy/myocarditis was the most frequent indication for ventricular assist device placement (n=14; 53.8%). Survival to discharge was 42.2% for extracorporeal membrane oxygenation patients and 54.2% for ventricular assist device patients. Kaplan–Meier 1-year survival was as follows: all patients, 41.0%; extracorporeal membrane oxygenation patients, 41.0%; and ventricular assist device patients, 43.2%. Kaplan–Meier 5-year survival was as follows: all patients, 39.7%; extracorporeal membrane oxygenation patients, 39.7%; and ventricular assist device patients, 43.2%.
This single-institutional 18-year review documents the differential probability of survival for various sub-groups of patients who require support with extracorporeal membrane oxygenation or ventricular assist device. The indication for mechanical circulatory support, underlying diagnosis, age, and setting in which cannulation occurs may affect survival after extracorporeal membrane oxygenation and ventricular assist device. The Kaplan–Meier analyses in this study demonstrate that patients who survive to hospital discharge have an excellent chance of longer-term survival.