Searching for gravitational wave bursts from cosmic string cusps with the Parkes Pulsar Timing Array

Cosmic strings are potential gravitational wave (GW) sources that can be probed by pulsar timing arrays (PTAs). In this work we develop a detection algorithm for a GW burst from a cusp on a cosmic string, and apply it to Parkes PTA data. We find four events with a false alarm probability less than 1%. However further investigation shows that all of these are likely to be spurious. As there are no convincing detections we place upper limits on the GW amplitude for different event durations. From these bounds we place limits on the cosmic string tension of G mu ~ 10^{-5}, and highlight that this bound is independent from those obtained using other techniques. We discuss the physical implications of our results and the prospect of probing cosmic strings in the era of Square Kilometre Array (SKA).Comment: Accepted for publication by MNRA

A one health approach to strengthening antimicrobial stewardship in Wakiso District, Uganda

Antimicrobial stewardship (AMS), as one of the global strategies to promote responsible use of antimicrobials to prevent antimicrobial resistance (AMR), remains poor in many low-and middle-income countries (LMICs). We implemented a project aimed at strengthening AMS in Wakiso district, Uganda using a One Health approach. A total of 86 health practitioners (HPs), including animal health workers, and 227 community health workers (CHWs) participated in training workshops, and over 300 pupils from primary schools were sensitized on AMR, AMS, and infection prevention and control (IPC). We further established two multidisciplinary online communities of practice (CoPs) for health professionals and students, with a current membership of 321 and 162, respectively. In addition, a Medicine and Therapeutics Committee (MTC) was set up at Entebbe Regional Referral Hospital. The project evaluation, conducted three months after training, revealed that the majority of the HPs (92.2%) and CHWs (90.3%) reported enhanced practices, including improved hand washing (57.3% and 81.0%, respectively). In addition, 51.5% of the HPs reported a reduction in the quantity of unnecessary antibiotics given per patient. This project demonstrates that AMS interventions using a One Health approach can promote understanding of the prudent use of antimicrobials and improve practices at health facilities and in communities

Observational longitudinal cohort study to determine progression to heart failure in a screened community population : the Echocardiographic Heart of England Screening Extension (ECHOES-X) study

OBJECTIVES: Rescreen a large community cohort to examine the progression to heart failure over time and the role of natriuretic peptide testing in screening. DESIGN: Observational longitudinal cohort study. SETTING: 16 socioeconomically diverse practices in central England. PARTICIPANTS: Participants from the original Echocardiographic Heart of England Screening (ECHOES) study were invited to attend for rescreening. OUTCOME MEASURES: Prevalence of heart failure at rescreening overall and for each original ECHOES subgroup. Test performance of N Terminal pro-B-type Natriuretic Peptide (NT-proBNP) levels at different thresholds for screening. RESULTS: 1618 of 3408 participants underwent screening which represented 47% of survivors and 26% of the original ECHOES cohort. A total of 176 (11%, 95% CI 9.4% to 12.5%) participants were classified as having heart failure at rescreening; 103 had heart failure with reduced ejection fraction (HFREF) and 73 had heart failure with preserved ejection fraction (HFPEF). Sixty-eight out of 1232 (5.5%, 95% CI 4.3% to 6.9%) participants who were recruited from the general population over the age of 45 and did not have heart failure in the original study, had heart failure on rescreening. An NT-proBNP cut-off of 400 pg/mL had sensitivity for a diagnosis of heart failure of 79.5% (95% CI 72.4% to 85.5%) and specificity of 87% (95% CI 85.1% to 88.8%). CONCLUSIONS: Rescreening identified new cases of HFREF and HFPEF. Progression to heart failure poses a significant threat over time. The natriuretic peptide cut-off level for ruling out heart failure must be low enough to ensure cases are not missed at screening

Frequent burning promotes invasions of alien plants into a mesic African savanna

Fire is both inevitable and necessary for maintaining the structure and functioning of mesic savannas. Without disturbances such as fire and herbivory, tree cover can increase at the expense of grass cover and over time dominate mesic savannas. Consequently, repeated burning is widely used to suppress tree recruitment and control bush encroachment. However, the effect of regular burning on invasion by alien plant species is little understood. Here, vegetation data from a long-term fire experiment, which began in 1953 in a mesic Zimbabwean savanna, were used to test whether the frequency of burning promoted alien plant invasion. The fire treatments consisted of late season fires, lit at 1-, 2-, 3-, and 4-year intervals, and these regularly burnt plots were compared with unburnt plots. Results show that over half a century of frequent burning promoted the invasion by alien plants relative to areas where fire was excluded. More alien plant species became established in plots that had a higher frequency of burning. The proportion of alien species in the species assemblage was highest in the annually burnt plots followed by plots burnt biennially. Alien plant invasion was lowest in plots protected from fire but did not differ significantly between plots burnt triennially and quadrennially. Further, the abundance of five alien forbs increased significantly as the interval (in years) between fires became shorter. On average, the density of these alien forbs in annually burnt plots was at least ten times as high as the density of unburnt plots. Plant diversity was also altered by long-term burning. Total plant species richness was significantly lower in the unburnt plots compared to regularly burnt plots. These findings suggest that frequent burning of mesic savannas enhances invasion by alien plants, with short intervals between fires favouring alien forbs. Therefore, reducing the frequency of burning may be a key to minimising the risk of alien plant spread into mesic savannas, which is important because invasive plants pose a threat to native biodiversity and may alter savanna functioning

Knowledge, perceptions and practices on antimicrobial resistance in humans and animals in Wakiso district, Uganda: a cross sectional study

Despite increasing evidence on antimicrobial resistance (AMR), there is limited literature on antimicrobial access and use in humans and animals in community settings globally. This study assessed knowledge and perceptions of AMR, as well as practices relating to the use of antimicrobials in humans and animals in Wakiso district, Uganda. This was a cross-sectional study among 418 participants that employed quantitative data collection methods. A structured questionnaire that included questions on knowledge, perceptions, practices related to AMR, and perceptions on access to antimicrobials in humans and animals was used. Data was analysed in STATA version 10. The majority of participants 63.6% (266/418) had heard about AMR mainly from family and friends 57.5% (153/266), and most 70.8% (296/418) were aware that resistant microorganisms cause infections that are difficult to treat. Most participants 62.7% (262/418) thought that they should complete the full dose of antimicrobials when on treatment. However, on the last occasion of antimicrobial use, 13.0% (44/338) revealed that they did not complete the full course of treatment. Participants who were single (APR = 1.12, C.I = 1.03–1.12, p-value = 0.01) and earning between 91 and 290 USD on average per month (APR = 1.12, C.I = 1.02–1.23, p-value = 0.02) were more likely to have completed a given antimicrobial course as compared to those who were married/cohabiting and earned less than 15 USD respectively. The majority of participants 60% (251/418) owned animals, and 81.3% (204/251) reported using antimicrobials mainly for prevention 61.3% (125/204) or treatment of sick animals 70.6% (144/204). Among the participants, 57.4% (117/204) reported not having sold or consumed animal products within a week after exposure to antimicrobials. Interventions to prevent AMR should adopt a One Health approach to address the gap in knowledge and practices relating to the use of antimicrobials in humans and animals

Scaling-up interventions for strengthening antimicrobial stewardship using a one health approach in Wakiso District, Uganda

We implemented a multidisciplinary project between Uganda and the UK aimed at strengthening antimicrobial stewardship (AMS) in Wakiso district, with a focus on capacity building, stakeholder engagement, and knowledge exchange using a One Health approach. Project activities included: trainings and workshops on antimicrobial resistance (AMR), AMS, infection prevention and control (IPC); Global Point Prevalence Survey (GPPS) data collection and analysis; and the mentorship of lower level health facilities. Our project demonstrated that AMS interventions using a One Health approach can enhance understanding of the prudent use of antimicrobials and improve practices at health facilities and within communities

Antimicrobial stewardship in private pharmacies in Wakiso district, Uganda: a qualitative study

Background: Private pharmacies are the first point of contact for the public regarding acquisition of medicines and other pharmaceuticals in many low- and middle-income countries including Uganda. Most antimicrobial stewardship (AMS) programmes in Uganda have targeted pharmacies in public health facilities, with little known about private pharmacies. This study explored knowledge and practices related to AMS in private pharmacies in Wakiso district, central Uganda. Methods: This was a qualitative study that involved 31 in-depth interviews to explore AMS among retail private pharmacy staff including pharmacists, pharmacy technicians/dispensers, and nurses. Participants were asked about antimicrobial resistance (AMR) and AMS practices at their pharmacy. The audio-recorded interviews were transcribed verbatim and imported to NVivo 2020 (QSR International) for thematic analysis. Results: Five major themes emerged from the study: commonly sold antimicrobials; knowledge on AMR and AMS; potential contributors to AMR; practices related to AMS; and challenges to AMS. The commonly sold antimicrobials in the pharmacies with or without prescriptions were oral azithromycin, Ampiclox® (ampicillin and cloxacillin), amoxicillin, ciprofloxacin, Septrin® (co-trimoxazole), metronidazole, Flucamox® (amoxicillin and flucloxacillin), Augmentin® (amoxicillin and clavulanic acid), cephalexin, doxycycline, and chloramphenicol. Participants had heard about AMR but not AMS, although only a few correctly defined AMR. Lack of knowledge among health workers and local communities; the overuse, misuse, and abuse of antimicrobials such as non-adherence to dosage; self-medication; and purchase of drugs without prescription were identified as potential accelerators to the emergence of AMR. Current practices related to AMS in private pharmacies were limited to meetings, antimicrobial dispensing, providing client advice, record keeping, and monitoring of drugs. Cost of healthcare, client satisfaction and retention, outdated guidelines, and the business orientation of pharmacies were the main challenges related to AMS. Conclusion: There was poor knowledge of AMR and AMS, and limited AMS practices in private pharmacies. Private pharmacies have the potential to contribute to Uganda’s fight against AMR if motivated and equipped with adequate knowledge to enhance their practices related to AMS

Access, use and disposal of antimicrobials among humans and animals in Wakiso district, Uganda: a qualitative study

Background: Inappropriate use of antimicrobials in both humans and animals is a key driver of antimicrobial resistance (AMR). In addition, human behaviours such as poor disposal of antimicrobials in the environment can increase their exposure to microbes which can impact on humans and animals. However, evidence on access, use and disposal of antimicrobials for humans and animals at community level in Uganda is limited. This study therefore explored access, use and disposal of antimicrobials among humans and animals in Wakiso district, Uganda. Methods: A qualitative study was conducted that involved focus group discussions (FGDs) and key informant interviews (KIIs). Participants of the FGDs were community health workers (CHWs) and farmers involved in animal husbandry, while key informants included: officials from the Ministry of Health; Ministry of Agriculture, Animal Industry and Fisheries; human and animal health professionals; district health officials; and members of the national AMR surveillance committee. Twelve FGDs were held (8 for CHWs and 4 for farmers) while 15 KIIs were conducted. Thematic analysis in NVivo (version 12) was performed. Results: Five main themes emerged from the study: access to antimicrobials in humans; access to antimicrobials in animals; use of antimicrobials in humans; use of antimicrobials in animals; and disposal of antimicrobials. Community members mainly accessed antimicrobials for humans from public health facilities such as government health centres, as well as private facilities, including drug shops and clinics. Antimicrobials for animals were obtained from veterinary practitioners and drug shops (both for humans and veterinary). Examples of inappropriate use of antimicrobials in both humans and animals was evident, such as sharing antibiotics among household members, and giving human-prescribed antimicrobials to food-producing animals as growth promoters. While some CHWs returned unused antimicrobials to public health facilities for proper disposal, community members mainly disposed of antimicrobials with general household waste including dumping in rubbish pits. Conclusions: There is a need to increase awareness among the population on proper access, use and disposal of antimicrobials for both humans and animals. Development of a drug disposal system at community level would facilitate improved waste management of antimicrobials. Together, these measures would help prevent the rate of progression of AMR in communities