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1.
Int J Parasitol Parasites Wildl ; 24: 100938, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38699516

ABSTRACT

A total of 333 vials of nematodes collected from three species of Isoodon (representing three individuals of I. auratus, 63 of I. fusciventer and 92 of I. obesulus) held in the Australian Helminthological Collection of the South Australian Museum were examined. Nematodes were identified and the nematode assemblages of the three hosts were compared with each other and with the assemblage of Isoodon macrourus. Two fully identified species were recovered from I. auratus, eight from I. fusciventer and 14 from I. obesulus. None of the species occurred in all three hosts; Labiobulura inglisi (Subuluridae), Peramelistrongylus skedastos (Dromaeostrongylidae) and Asymmetracantha tasmaniensis (Mackerrastrongylidae) all occurred in I. fusciventer and I. obesulus. Only Pe. skedastos was also found in I. macrourus. Sorensen's index of similarity, 27.2 %, showed that I. fusciventer and I. obesulus did not have similar nematode communities and neither were their communities similar to that of I. macrourus, 17.1 % and 39.0 % respectively. Labiobulura inglisi and Linstowinema inglisi were the dominant nematodes in the assemblage of I. fusciventer and La. inglisi was dominant in I. obesulus. The two hosts had nematode assemblages with unique species profiles; one species of Linstowinema in I. fusciventer, three in I. obesulus; a species of Physaloptera in I. obesulus, none in I. fusciventer; four species of strongylid; Asymmetracantha tasmaniensis the most prevalent in I. fusciventer, Peramelistrongylus skedastos the most prevalent in I.obesulus. The size of the geographic range is a probable determinant of the species richness of the nematode assemblages.

2.
Phys Rev Lett ; 132(19): 195001, 2024 May 10.
Article in English | MEDLINE | ID: mdl-38804956

ABSTRACT

Experiments were performed on laser wakefield acceleration in the highly nonlinear regime. With laser powers P<250 TW and using an initial spot size larger than the matched spot size for guiding, we were able to accelerate electrons to energies E_{max}>2.5 GeV, in fields exceeding 500 GV m^{-1}, with more than 80 pC of charge at energies E>1 GeV. Three-dimensional particle-in-cell simulations show that using an oversized spot delays injection, avoiding beam loss as the wakefield undergoes length oscillation. This enables injected electrons to remain in the regions of highest accelerating fields and leads to a doubling of energy gain as compared to results from using half the focal length with the same laser.

3.
Ultrasound Obstet Gynecol ; 63(4): 481-488, 2024 04.
Article in English | MEDLINE | ID: mdl-37820067

ABSTRACT

OBJECTIVE: Placental vascular reactivity (PlVR) indicates the ability of the placental vasculature to match blood supply to fetal demand. Many pregnancy disorders alter the characteristics of PlVR, resulting in suboptimal oxygen delivery, although current understanding is limited by the lack of non-invasive, repeatable methods to measure PlVR in utero. Our objective was to quantify PlVR by measuring the placental response to transient changes in maternal carbon dioxide (CO2) using blood-oxygen-level-dependent (BOLD) magnetic resonance imaging (MRI). We hypothesized that PlVR will increase with gestational age to meet the changing demands of a growing fetus, and that PlVR will be driven by a maternal response to changes in CO2 concentration. METHODS: This was a cross-sectional study of 35 women with a healthy singleton pregnancy, of whom 31 were included in the analysis. The median gestational age was 32.6 (range, 22.6-38.4) weeks. Pregnant women were instructed to follow audiovisual breathing cues during a MRI scan. Maternal end-tidal CO2 (EtCO2) was measured concurrently with resting placental BOLD MRI for a total of 7-8 min. Preprocessing of magnetic resonance images consisted of manual delineation of placental anatomy and motion correction. In each placental voxel, vascular reactivity was computed using a coherence-weighted general linear model between MRI signal and EtCO2 stimulus. Global PlVR was computed as the mean of voxel-wise PlVR values across the placenta. RESULTS: PlVR, quantified by the placental response to induced, transient changes in maternal CO2, was consistently measured in utero using BOLD MRI. PlVR increased non-linearly with advancing gestational age (P < 0.001) and was higher on the fetal side of the placenta. PlVR was associated positively with fetal brain volume after accounting for gestational age. PlVR did not show any significant associations with maternal characteristics. CONCLUSIONS: We present, for the first time, a non-invasive paradigm to quantify PlVR in ongoing human pregnancies without the use of exogenous gases or contrast agents. Our findings suggest that PlVR is driven by a fetal response to changes in maternal CO2. Ease of translation to the clinical setting makes PlVR a promising biomarker for the identification and management of high-risk pregnancies. © 2023 The Authors. Ultrasound in Obstetrics & Gynecology published by John Wiley & Sons Ltd on behalf of International Society of Ultrasound in Obstetrics and Gynecology.


Subject(s)
Placenta , Pregnancy Complications , Pregnancy , Female , Humans , Infant , Placenta/blood supply , Cross-Sectional Studies , Carbon Dioxide , Magnetic Resonance Imaging/methods , Oxygen
4.
J Helminthol ; 97: e79, 2023 Oct 19.
Article in English | MEDLINE | ID: mdl-37853777

ABSTRACT

A total of 235 vials of nematodes held in the Australian Helminthological Collection of the South Australian Museum from 125 individuals of Isoodon macrourus were examined. The nematode assemblage of I. macrourus, comprising 12 families, including 16 genera and 23 identified species, was compared with the sympatric bandicoot species Perameles nasuta, 20 identified species (Sorensen's index of similarity 0.56) and P. pallescens, 12 identified species (Sorensen's index 0.51). Sprattellus cassonei n. sp. is distinguished from its congeners by having a synlophe with 7-8 ridges with the anterior ventral ridges interrupted, the morphology of the dorsal ray and the branching of the spicule tips. A single male specimen identified as Linstowinema sp. 1. is characterised by seven circles of body hooks, the oesophagus terminating at the level of the seventh circle and robust scale-like spines on the posterior ventral body. A complete description of the species will require additional material, including females. Difficulties in identifying individuals of the genus Mackerrastrongylus to species level are discussed. Overall similarities in the nematode assemblages of the three bandicoot hosts are likely due to shared relationships and similar behaviours.


Subject(s)
Marsupialia , Nematoda , Trichostrongyloidea , Humans , Female , Animals , Male , South Australia , Australia , Museums
5.
Pharm Res ; 40(9): 2195-2214, 2023 Sep.
Article in English | MEDLINE | ID: mdl-37634241

ABSTRACT

PURPOSE: To construct a detailed mechanistic and physiologically based biopharmaceutics model capable of predicting 1) device-formulation-tissue interaction during the injection process and 2) binding, degradation, local distribution, diffusion, and drug absorption, following subcutaneous injection. This paper is part of a series and focusses on the first aspect. METHODS: A mathematical model, SubQ-Sim, was developed incorporating the details of the various substructures within the subcutaneous environment together with the calculation of dynamic drug disposition towards the lymph ducts and venous capillaries. Literature was searched to derive key model parameters in healthy and diseased subjects. External factors such as body temperature, exercise, body position, food or stress provide a means to calculate the impact of "life events" on the pharmacokinetics of subcutaneously administered drugs. RESULTS: The model predicts the tissue backpressure time profile during the injection as a function of injection rate, volume injected, solution viscosity, and interstitial fluid viscosity. The shape of the depot and the concentrations of the formulation and proteins in the depot are described. The model enables prediction of formulation backflow following premature needle removal and the resulting formulation losses. Finally, the effect of disease (type 2 diabetes) or the presence of recombinant human hyaluronidase in the formulation on the injection pressure, are explored. CONCLUSIONS: This novel model can successfully predict tissue back pressure, depot dimensions, drug and protein concentration and formulation losses due to incorrect injection, which are all important starting conditions for predicting drug absorption from a subcutaneous dose. The next article will describe the absorption model and validation against clinical data.


Subject(s)
Biopharmaceutics , Diabetes Mellitus, Type 2 , Humans , Biopharmaceutics/methods , Models, Biological , Injections, Subcutaneous , Proteins
8.
Early Child Educ J ; : 1-12, 2023 Apr 27.
Article in English | MEDLINE | ID: mdl-37360600

ABSTRACT

This study investigated microaggressions Black children experienced in early childhood education during the pandemic. Using racial microaggressions as a framework, we sought to gain insights into these experiences through counter-narratives from parents of Black children. Parents provided unique insights into their children's experiences, giving voice to their daily realities in early learning contexts. This article focuses on how Black children are treated with second-class student status. Black children being positioned with second-class status was the most predominant theme from this work during the pandemic. This is noteworthy, as few studies have considered how the pandemic uniquely shaped Black children's educational realities.

9.
Phys Rev Lett ; 129(24): 244801, 2022 Dec 09.
Article in English | MEDLINE | ID: mdl-36563240

ABSTRACT

We report on a novel, noninvasive method applying Thomson scattering to measure the evolution of the electron beam energy inside a laser-plasma accelerator with high spatial resolution. The determination of the local electron energy enabled the in-situ detection of the acting acceleration fields without altering the final beam state. In this Letter we demonstrate that the accelerating fields evolve from (265±119) GV/m to (9±4) GV/m in a plasma density ramp. The presented data show excellent agreement with particle-in-cell simulations. This method provides new possibilities for detecting the dynamics of plasma-based accelerators and their optimization.

10.
Sci Rep ; 12(1): 19967, 2022 11 19.
Article in English | MEDLINE | ID: mdl-36402889

ABSTRACT

To reduce the veterinary, public health, environmental, and economic burden associated with anthrax outbreaks, it is vital to identify the spatial distribution of areas suitable for Bacillus anthracis, the causative agent of the disease. Bayesian approaches have previously been applied to estimate uncertainty around detected areas of B. anthracis suitability. However, conventional simulation-based techniques are often computationally demanding. To solve this computational problem, we use Integrated Nested Laplace Approximation (INLA) which can adjust for spatially structured random effects, to predict the suitability of B. anthracis across Uganda. We apply a Generalized Additive Model (GAM) within the INLA Bayesian framework to quantify the relationships between B. anthracis occurrence and the environment. We consolidate a national database of wildlife, livestock, and human anthrax case records across Uganda built across multiple sectors bridging human and animal partners using a One Health approach. The INLA framework successfully identified known areas of species suitability in Uganda, as well as suggested unknown hotspots across Northern, Eastern, and Central Uganda, which have not been previously identified by other niche models. The major risk factors for B. anthracis suitability were proximity to water bodies (0-0.3 km), increasing soil calcium (between 10 and 25 cmolc/kg), and elevation of 140-190 m. The sensitivity of the final model against the withheld evaluation dataset was 90% (181 out of 202 = 89.6%; rounded up to 90%). The prediction maps generated using this model can guide future anthrax prevention and surveillance plans by the relevant stakeholders in Uganda.


Subject(s)
Anthrax , Bacillus anthracis , Humans , Animals , Anthrax/epidemiology , Anthrax/veterinary , Bayes Theorem , Uganda , Disease Outbreaks/veterinary
11.
Int J Pediatr Otorhinolaryngol ; 158: 111157, 2022 Jul.
Article in English | MEDLINE | ID: mdl-35504226

ABSTRACT

INTRODUCTION: Tracheomalacia is a common congenital condition causing stridor in young children. However, the evaluation of these children remains poorly standardised across institutions. METHODS: We conducted a retrospective review of all children undergoing an elective laryngotracheobronchoscopy at a single tertiary paediatric institution between March 2010 and December 2018. Emergency bronchoscopies and children with tracheostomies were excluded. 1163 children undergoing an elective bronchoscopy were included in this study, and 545 children also had an airway fluoroscopy. RESULTS: The median age at bronchoscopy was 17 months, and the majority of children were male. Tracheomalacia was diagnosed in 21.6% of children at bronchoscopy, of these 48.5% had tracheomalacia diagnosed on a previous airway fluoroscopy. Overall, airway fluoroscopy had a low sensitivity (62.3%) and a low specificity (67.5%) for diagnosis of tracheomalacia when compared with bronchoscopy. Increasing severity of tracheomalacia on airway screen significantly predicted a diagnosis of tracheomalacia on bronchoscopy. CONCLUSIONS: Airway fluoroscopy has a low sensitivity and specificity in diagnosis of tracheomalacia and should be used judiciously rather than as a screening tool for children with stridor. However, this imaging technique may be beneficial in investigating children with severe symptoms who have had other conditions such as laryngomalacia excluded.


Subject(s)
Tracheomalacia , Bronchoscopy/methods , Child , Child, Preschool , Congenital Abnormalities , Female , Fluoroscopy/methods , Humans , Infant , Larynx/abnormalities , Male , Respiratory Sounds/etiology , Retrospective Studies , Tracheomalacia/complications , Tracheomalacia/diagnostic imaging
12.
Epidemics ; 39: 100569, 2022 06.
Article in English | MEDLINE | ID: mdl-35597098

ABSTRACT

The effort for combating the COVID-19 pandemic around the world has resulted in a huge amount of data, e.g., from testing, contact tracing, modelling, treatment, vaccine trials, and more. In addition to numerous challenges in epidemiology, healthcare, biosciences, and social sciences, there has been an urgent need to develop and provide visualisation and visual analytics (VIS) capacities to support emergency responses under difficult operational conditions. In this paper, we report the experience of a group of VIS volunteers who have been working in a large research and development consortium and providing VIS support to various observational, analytical, model-developmental, and disseminative tasks. In particular, we describe our approaches to the challenges that we have encountered in requirements analysis, data acquisition, visual design, software design, system development, team organisation, and resource planning. By reflecting on our experience, we propose a set of recommendations as the first step towards a methodology for developing and providing rapid VIS capacities to support emergency responses.


Subject(s)
COVID-19 , COVID-19/epidemiology , Contact Tracing , Humans , Pandemics
13.
Biofouling ; 38(3): 298-320, 2022 03.
Article in English | MEDLINE | ID: mdl-35361009

ABSTRACT

Cathodic protection (CP), an electrochemical method for managing corrosion, is widely used in many industries in both marine and buried environments. However, literature surrounding cathodic protection and its ability to prevent microbially influenced corrosion (MIC) is mixed. This review describes the mechanics of CP, how CP may influence MIC, and collates and summarises tests on CP and MIC reported in literature. The aim of the review is to identify any trends and knowledge gaps requiring further study. While the outcomes of CP testing are generally mixed, some trends can be seen and, overall, MIC is detrimental to the protective effects of CP, with CP being less effective when used according to current international standards. Tests conducted in the field or with mix communities of microbes showed that CP could be effective at preventing MIC, while tests with sulfate-reducing bacteria generally proved CP to be highly ineffective. It was commonly seen that the effectiveness of CP can be improved by increasing polarization, to potentials as low as -1000 mV (Ag/AgCl). However, a balance does need to be met via careful monitoring to ensure negative side effects of over protection do not become a major problem.


Subject(s)
Biofilms , Corrosion , Electrodes
14.
Phys Rev Lett ; 128(8): 083001, 2022 Feb 25.
Article in English | MEDLINE | ID: mdl-35275674

ABSTRACT

Photoelectron interferometry with femtosecond and attosecond light pulses is a powerful probe of the fast electron wave-packet dynamics, albeit it has practical limitations on the energy resolution. We show that one can simultaneously obtain both high temporal and spectral resolution by stimulating Raman interferences with one light pulse and monitoring the modification of the electron yield in a separate step. Applying this spectroscopic approach to the autoionizing states of argon, we experimentally resolved its electronic composition and time evolution in exquisite detail. Theoretical calculations show remarkable agreement with the observations and shed light on the light-matter interaction parameters. Using appropriate Raman probing and delayed detection steps, this technique enables highly sensitive probing and control of electron dynamics in complex systems.

15.
Psychol Med ; 52(5): 989-1000, 2022 04.
Article in English | MEDLINE | ID: mdl-32878667

ABSTRACT

BACKGROUND: To test the functional implications of impaired white matter (WM) connectivity among patients with schizophrenia and their relatives, we examined the heritability of fractional anisotropy (FA) measured on diffusion tensor imaging data acquired in Pittsburgh and Philadelphia, and its association with cognitive performance in a unique sample of 175 multigenerational non-psychotic relatives of 23 multiplex schizophrenia families and 240 unrelated controls (total = 438). METHODS: We examined polygenic inheritance (h2r) of FA in 24 WM tracts bilaterally, and also pleiotropy to test whether heritability of FA in multiple WM tracts is secondary to genetic correlation among tracts using the Sequential Oligogenic Linkage Analysis Routines. Partial correlation tests examined the correlation of FA with performance on eight cognitive domains on the Penn Computerized Neurocognitive Battery, controlling for age, sex, site and mother's education, followed by multiple comparison corrections. RESULTS: Significant total additive genetic heritability of FA was observed in all three-categories of WM tracts (association, commissural and projection fibers), in total 33/48 tracts. There were significant genetic correlations in 40% of tracts. Diagnostic group main effects were observed only in tracts with significantly heritable FA. Correlation of FA with neurocognitive impairments was observed mainly in heritable tracts. CONCLUSIONS: Our data show significant heritability of all three-types of tracts among relatives of schizophrenia. Significant heritability of FA of multiple tracts was not entirely due to genetic correlations among the tracts. Diagnostic group main effect and correlation with neurocognitive performance were mainly restricted to tracts with heritable FA suggesting shared genetic effects on these traits.


Subject(s)
Cognitive Dysfunction , Schizophrenia , White Matter , Anisotropy , Brain , Cognitive Dysfunction/genetics , Diffusion Tensor Imaging/methods , Humans , Schizophrenia/genetics , White Matter/diagnostic imaging
16.
Public Health Nutr ; 24(13): 4313-4327, 2021 09.
Article in English | MEDLINE | ID: mdl-34247694

ABSTRACT

OBJECTIVE: Refugees are vulnerable to food insecurity (FI). This is attributable to a combination of inequitable social determinants and cultural differences. In 2019, 92 % of refugee resettlement (host country provides residency/citizenship) occurred in high-income countries, but little is known about the factors impacting their food security status in this setting. The review's objective was to therefore thematically identify factors affecting food security among refugees resettling in high-income countries. DESIGN: This review was based on the Preferred Reporting Items for Systematic Reviews and Meta-Analyses extension for Scoping Reviews. Between May-July 2020 and February 2021, peer-reviewed studies focused on FI, and published in English from 2000-2020, were searched on Medline, CINAHL, Scopus, Informit, PsychArticles, Proquest and EmBase. SETTING: Only studies set in high-income countries were included. PARTICIPANTS: Fifty percent or more of study participants had to be refugees who had resettled within 5 years. RESULTS: Twenty studies from six high-income countries were included. Culturally based food practices and priorities, confidence in navigating local foodways and transport, level of community connections and capabilities in local language and food preparation were key themes associated with food security. CONCLUSIONS: Utilising the four themes of culture, confidence, community and capabilities, there is an opportunity to improve the cultural sensitivity of measurement tools, develop understanding of how community-based resources (such as social capital) can be leveraged as food security buffers and modify existing food security initiatives to better serve refugee needs.


Subject(s)
Refugees , Developed Countries , Food Security , Food Supply , Humans , Income
17.
Appl Environ Microbiol ; 87(18): e0089021, 2021 08 26.
Article in English | MEDLINE | ID: mdl-34232755

ABSTRACT

One of the key areas in which microbially influenced corrosion (MIC) has been found to be a problem is in the bilges of maritime vessels. To establish effective biological monitoring protocols, baseline knowledge of the temporal and spatial biological variation within bilges, as well as the effectiveness of different sampling methodologies, is critical. We used 16S rRNA gene metabarcoding of pelagic and sessile bacterial communities from ship bilges to assess the variation in bilge bacterial communities to determine how the inherent bilge diversity could guide or constrain biological monitoring. Bilge communities exhibited high levels of spatial and temporal variation, with >80% of the community able to be turned over in the space of 3 months, likely due to disturbance events such as cleaning and maintenance. Sessile and pelagic communities within a given bilge were also inherently distinct, with dominant exact sequence variants (ESVs) rarely shared between the two. Taxa containing KEGG orthologies (KOs) associated with dissimilatory sulfate reduction and biofilm production, functions typically associated with MIC, were generally more prevalent in sessile communities. Collectively, our findings indicate that neither bilge water nor an unaffected bilge from within the same vessel would constitute an appropriate reference community for MIC diagnosis. Optimal sampling locations and strategies that could be incorporated into a standardized method for monitoring bilge biology in relation to MIC were identified. Finally, taxonomic and functional comparisons of bilge diversity highlight the potential of functional approaches in future biological monitoring of MIC and MIC mitigation strategies in general. IMPORTANCE Microbially influenced corrosion (MIC) has been estimated to contribute 20 to 50% of the costs associated with corrosion globally. Diagnosis and monitoring of MIC are complex problems requiring knowledge of corrosion rates, corrosion morphology, and the associated microbiology to distinguish MIC from abiotic corrosion processes. Historically, biological monitoring of MIC utilized a priori knowledge to monitor sulfate-reducing bacteria; however, it is becoming widely accepted that a holistic or community-level understanding of corrosion-associated microbiology is needed for MIC diagnosis and monitoring. Before biology associated with MIC attack can be identified, standardized protocols for sampling and monitoring must be developed. The significance of our research is in contributing to the development of robust and repeatable sampling strategies of bilges, which are required for the development of standardized biological monitoring methods for MIC. We achieve this via a biodiversity survey of bilge communities and by comparing taxonomic and functional variation.


Subject(s)
Ships , Wastewater/microbiology , Bacteria/classification , Bacteria/genetics , Corrosion , Microbiota , RNA, Ribosomal, 16S/genetics , Water Microbiology
18.
Med Biol Eng Comput ; 59(5): 1065-1079, 2021 May.
Article in English | MEDLINE | ID: mdl-33881704

ABSTRACT

A finite element (FE)-guided mathematical surrogate modeling methodology is presented for evaluating relative injury trends across varied vehicular impact conditions. The prevalence of crash-induced injuries necessitates the quantification of the human body's response to impacts. FE modeling is often used for crash analyses but requires time and computational cost. However, surrogate modeling can predict injury trends between the FE data, requiring fewer FE simulations to evaluate the complete testing range. To determine the viability of this methodology for injury assessment, crash-induced occupant head injury criterion (HIC15) trends were predicted from Kriging models across varied impact velocities (10-45 mph; 16.1-72.4 km/h), locations (near side, far side, front, and rear), and angles (-45 to 45°) and compared to previously published data. These response trends were analyzed to locate high-risk target regions. Impact velocity and location were the most influential factors, with HIC15 increasing alongside the velocity and proximity to the driver. The impact angle was dependent on the location and was minimally influential, often producing greater HIC15 under oblique angles. These model-based head injury trends were consistent with previously published data, demonstrating great promise for the proposed methodology, which provides effective and efficient quantification of human response across a wide variety of car crash scenarios, simultaneously. This study presents a finite element-guided mathematical surrogate modeling methodology to evaluate occupant injury response trends for a wide range of impact velocities (10-45 mph), locations, and angles (-45 to 45°). Head injury response trends were predicted and compared to previously published data to assess the efficacy of the methodology for assessing occupant response to variations in impact conditions. Velocity and location were the most influential factors on the head injury response, with the risk increasing alongside greater impact velocity and locational proximity to the driver. Additionally, the angle of impact variable was dependent on the location and, thus, had minimal independent influence on the head injury risk.


Subject(s)
Accidents, Traffic , Craniocerebral Trauma , Biomechanical Phenomena , Craniocerebral Trauma/epidemiology , Finite Element Analysis , Head , Humans
19.
Epidemiol Infect ; 149: e69, 2021 02 24.
Article in English | MEDLINE | ID: mdl-33622436

ABSTRACT

The Ethiopian government has several initiatives to expand and intensify the dairy industry; however, the risk of bovine tuberculosis (bTB) spread is a challenge. To assess the rate of expansion and risk factors for transmission of bTB within-herds, we carried out a repeated cross-sectional survey at two time points, 2016/17 and 2018, in three regional cities, namely, Gondar, Hawassa and Mekelle, representing the emerging dairy belts of Ethiopia. The total number of herds involved was 128, comprising an average of 2303 cattle in each round. The Single Intradermal Comparative Cervical Tuberculin (SICCT) test was used to identify reactor status and data on herd-level risk factors were collected using a structured questionnaire. In the first survey, the apparent prevalence of bTB, as measured by the SICCT test, was 4.5% (95% CI 3.7-5.4%) at the individual animal-level and 24% (95% CI 17.5-32%) at the herd-level. There was no statistically significant change in the overall apparent prevalence or regional distribution at the second survey, consistent with the infection being endemic. The incidence rate was estimated at 3.6 (95% CI 2.8-4.5) and 6.6 (95% CI 3.0-12.6) cases/100 cattle (or herd)-years at the animal- and herd-levels, respectively. Risk factors significantly associated with the within-herd transmission of bTB were age group and within-herd apparent prevalence at the start of the observation period. We noted that farmers voluntarily took steps to remove reactor cattle from their herds as a consequence of the information shared after the first survey. Removal of reactors between surveys was associated with a reduced risk of transmission within these herds. However, with no regulatory barriers to the sale of reactor animals, such actions could potentially lead to further spread between herds. We therefore advocate the importance of setting up regulations and then establishing a systematic bTB surveillance programme to monitor the impact prior to implementing any control measures in Ethiopia.


Subject(s)
Dairying , Tuberculosis, Bovine/epidemiology , Animals , Cattle , Cross-Sectional Studies , Ethiopia/epidemiology , Farmers , Humans , Incidence , Risk Factors , Skin Tests/veterinary
20.
Phys Rev Lett ; 126(1): 014801, 2021 Jan 08.
Article in English | MEDLINE | ID: mdl-33480753

ABSTRACT

Energy-efficient plasma-wakefield acceleration of particle bunches with low energy spread is a promising path to realizing compact free-electron lasers and particle colliders. High efficiency and low energy spread can be achieved simultaneously by strong beam loading of plasma wakefields when accelerating bunches with carefully tailored current profiles [M. Tzoufras et al., Phys. Rev. Lett. 101, 145002 (2008)PRLTAO0031-900710.1103/PhysRevLett.101.145002]. We experimentally demonstrate such optimal beam loading in a nonlinear electron-driven plasma accelerator. Bunches with an initial energy of 1 GeV were accelerated by 45 MeV with an energy-transfer efficiency of (42±4)% at a gradient of 1.3 GV/m while preserving per-mille energy spreads with full charge coupling, demonstrating wakefield flattening at the few-percent level.

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