Regional and temporal variations in COVID-19 cases and deaths in Ethiopia: Lessons learned from the COVID-19 enhanced surveillance and response.

BACKGROUND: The COVID-19 pandemic is one of the most devastating public health emergencies of international concern to have occurred in the past century. To ensure a safe, scalable, and sustainable response, it is imperative to understand the burden of disease, epidemiological trends, and responses to activities that have already been implemented. We aimed to analyze how COVID-19 tests, cases, and deaths varied by time and region in the general population and healthcare workers (HCWs) in Ethiopia. METHODS: COVID-19 data were captured between October 01, 2021, and September 30, 2022, in 64 systematically selected health facilities throughout Ethiopia. The number of health facilities included in the study was proportionally allocated to the regional states of Ethiopia. Data were captured by standardized tools and formats. Analysis of COVID-19 testing performed, cases detected, and deaths registered by region and time was carried out. RESULTS: We analyzed 215,024 individuals' data that were captured through COVID-19 surveillance in Ethiopia. Of the 215,024 total tests, 18,964 COVID-19 cases (8.8%, 95% CI: 8.7%- 9.0%) were identified and 534 (2.8%, 95% CI: 2.6%- 3.1%) were deceased. The positivity rate ranged from 1% in the Afar region to 15% in the Sidama region. Eight (1.2%, 95% CI: 0.4%- 2.0%) HCWs died out of 664 infected HCWs, of which 81.5% were from Addis Ababa. Three waves of outbreaks were detected during the analysis period, with the highest positivity rate of 35% during the Omicron period and the highest rate of ICU beds and mechanical ventilators (38%) occupied by COVID-19 patients during the Delta period. CONCLUSIONS: The temporal and regional variations in COVID-19 cases and deaths in Ethiopia underscore the need for concerted efforts to address the disparities in the COVID-19 surveillance and response system. These lessons should be critically considered during the integration of the COVID-19 surveillance system into the routine surveillance system.

Effects of aggregate sizes on the performance of laterized concrete.

Due to the high costs of traditional concrete materials in Nigeria, such as river sand, there is an increasing demand to explore alternative materials like laterite for fine aggregates. Although laterite is abundant in Nigeria, its full potential in the construction industry remains untapped. Previous studies have shown that partially replacing river sand with laterite produces concrete with competitive strength properties. This research aims to validate and extend these findings, evaluating the impact of different aggregate sizes (12 mm, 20 mm, and 40 mm) on the strength of concrete with 10% and 25% laterite replacements for fine aggregate. Results revealed that as the laterite percentage increased, compressive, flexural, and split tensile strengths decreased. While 0% and 10% laterite replacements met the required strength, the mix with 25% laterite fell short. Increasing maximum coarse aggregate size led to higher strengths, with 40 mm sizes exhibiting the highest, and 12 mm the lowest. Compressive strengths ranged from 22.1 to 37.6 N/mm2, flexural strengths from 4.07 to 5.99 N/mm2 and split-tensile strengths from 2.93 to 4.30 N/mm2. This research highlights the need for meticulous mix design adjustments when using laterite, balancing workability with strength objectives. The developed regression models offer a valuable tool for predicting concrete properties based on mix parameters, providing insights for optimizing laterized concrete designs across diverse construction applications and supporting sustainable building practices.

Effects of elevated temperatures on the mechanical properties of laterized concrete.

This study explored the impact of elevated temperatures on the residual structural properties of concrete made with a non-conventional fine aggregate such as laterite and quarry dust. In regions prone to high temperatures, such as tropical climates, the structural integrity of concrete can be compromised when exposed to elevated temperatures. Concrete samples were subjected to high temperatures (250 °C) and compared with control samples tested under normal conditions. In this research, the concrete mix was altered by replacing fine aggregates with different combinations of laterite (Lat) and quarry dust (QD) at varying percentages: 10%Lat:90%QD, 25%Lat:75%QD, 90%Lat:10%QD, 75%Lat:25%QD, and 50%Lat:50%QD. The physical properties of the constituent aggregates, including sand, laterite, quarry dust, and granite, were assessed, and an experimental mix was designed. The concrete samples underwent curing for 3, 7, 14, and 28 days, and their mechanical properties, specifically compression and flexural strength, were analyzed. The results demonstrated that as the percentage of laterite in the concrete matrix increased, there was a linear improvement in performance in terms of density, sorptivity, and strength gain. The maximum compressive strength reached 32.80 N/mm2 at 90% laterite replacement. However, flexural strength showed a different response, with the highest strength of 5.99 N/mm2 observed at 50% laterite replacement, after which strength declined with further increases in the laterite ratio. For economic and engineering considerations, it is recommended to use 25% laterite replacement with sand to produce grade 30 concrete, while 50% laterite replacement is suitable for grade-25 concrete. Importantly, the study found that a temperature of 250 °C did not significantly affect concrete strength, with changes of no more than 5%, which is consistent with expectations for conventional concrete. Furthermore, this research suggests that an optimal laterite replacement range of 25-50% should be considered when using laterite in concrete production.

Evaluation of Ethiopia's field epidemiology training program - frontline: perspectives of implementing partners.

BACKGROUND: Field Epidemiology Training Program (FETP) has been adopted as an epidemiology and response capacity building strategy worldwide. FETP-Frontline was introduced in Ethiopia in 2017 as a three-month in-service training. In this study, we evaluated implementing partners' perspectives with the aim of understanding program effectiveness and identifying challenges and recommendations for improvement. METHODS: A qualitative cross-sectional design was utilized to evaluate Ethiopia's FETP-Frontline. Using a descriptive phenomenological approach, qualitative data were collected from FETP-Frontline implementing partners, including regional, zonal, and district health offices across Ethiopia. We collected data through in-person key informant interviews, using semi-structured questionnaires. Thematic analysis was conducted, assisted with MAXQDA, while ensuring interrater reliability by using the consistent application of theme categorization. The major themes that emerged were program effectiveness, knowledge and skills differences between trained and untrained officers, program challenges, and recommended actions for improvement. Ethical approval was obtained from the Ethiopian Public Health Institute. Informed written consent was obtained from all participants, and confidentiality of the data was maintained throughout. RESULTS: A total of 41 interviews were conducted with key informants from FETP-Frontline implementing partners. The regional and zonal level experts and mentors had a Master of Public Health (MPH), whereas district health managers were Bachelor of Science (BSc) holders. Majority of the respondents reflected a positive perception towards FETP-Frontline. Regional and zonal officers as well as mentors mentioned that there were observable performance differences between trained and untrained district surveillance officers. They also identified various challenges including lack of resources for transportation, budget constraints for field projects, inadequate mentorship, high staff turnover, limited number of staff at the district level, lack of continued support from stakeholders, and the need for refresher training for FETP-Frontline graduates. CONCLUSIONS: Implementing partners reflected a positive perception towards FETP-Frontline in Ethiopia. In addition to scaling-up the program to reach all districts to achieve the International Health Regulation 2005 goals, the program also needs to consider addressing immediate challenges, primarily lack of resources and poor mentorship. Continued monitoring of the program, refresher training, and career path development could improve retention of the trained workforce.

Scheffe's Simplex Optimization of Flexural Strength of Quarry Dust and Sawdust Ash Pervious Concrete for Sustainable Pavement Construction.

Pervious concrete provides a tailored surface course with high permeability properties which permit the easy flow of water through a larger interconnected porous structure to prevent flooding hazards. This paper reports the modeling of the flexural properties of quarry dust (QD) and sawdust ash (SDA) blended green pervious concrete for sustainable road pavement construction using Scheffe's (5,2) optimization approach. The simplex mixture design method was adapted to formulate the mixture proportion to eliminate the set-backs encountered in empirical or trials and the error design approach, which consume more time and resources to design with experimental runs required to evaluate the response function. For the laboratory evaluation exercise, a maximum flexural strength of 3.703 N/mm2 was obtained with a mix proportion of 0.435:0.95:0.1:1.55:0.05 for water, cement, QD, coarse aggregate and SDA, respectively. Moreover, the minimal flexural strength response of 2.504 N/mm2 was obtained with a mix ratio of 0.6:0.75:0.3:4.1:0.25 for water, cement, QD, coarse aggregate and SDA, respectively. The test of the appropriateness of the developed model was statistically verified using the Student' t-test and an analysis of variance (ANOVA), and was confirmed to be acceptable based on computational outcomes at the 95% confidence interval. Furthermore, the scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) were used to evaluate the morphological and mineralogical behavior of green prior concrete samples with various additive mixture compositions. The addition of QD and SDA, on the other hand, aided the creation of porous microstructures in the concrete matrix due to fabric changes in the concrete mixture, potentially aided by the formation of cementitious compounds such as calcium aluminate hydrate and calcium silicate hydrate.

Risk Factors for Ebola Virus Persistence in Semen of Survivors in Liberia.

BACKGROUND: Long-term persistence of Ebola virus (EBOV) in immunologically privileged sites has been implicated in recent outbreaks of Ebola virus disease (EVD) in Guinea and the Democratic Republic of Congo. This study was designed to understand how the acute course of EVD, convalescence, and host immune and genetic factors may play a role in prolonged viral persistence in semen. METHODS: A cohort of 131 male EVD survivors in Liberia were enrolled in a case-case study. "Early clearers" were defined as those with 2 consecutive negative EBOV semen test results by real-time reverse-transcription polymerase chain reaction (rRT-PCR) ≥2 weeks apart within 1 year after discharge from the Ebola treatment unit or acute EVD. "Late clearers" had detectable EBOV RNA by rRT-PCR >1 year after discharge from the Ebola treatment unit or acute EVD. Retrospective histories of their EVD clinical course were collected by questionnaire, followed by complete physical examinations and blood work. RESULTS: Compared with early clearers, late clearers were older (median, 42.5 years; P < .001) and experienced fewer severe clinical symptoms (median 2, P = .006). Late clearers had more lens opacifications (odds ratio, 3.9 [95% confidence interval, 1.1-13.3]; P = .03), after accounting for age, higher total serum immunoglobulin G3 (IgG3) titers (P = .005), and increased expression of the HLA-C*03:04 allele (0.14 [.02-.70]; P = .007). CONCLUSIONS: Older age, decreased illness severity, elevated total serum IgG3 and HLA-C*03:04 allele expression may be risk factors for the persistence of EBOV in the semen of EVD survivors. EBOV persistence in semen may also be associated with its persistence in other immunologically protected sites, such as the eye.

Does Host Plant Drive Variation in Microbial Gut Communities in a Recently Shifted Pest?

Biotic interactions can modulate the responses of organisms to environmental stresses, including diet changes. Gut microbes have substantial effects on diverse ecological and evolutionary traits of their hosts, and microbial communities can be highly dynamic within and between individuals in space and time. Modulations of the gut microbiome composition and their potential role in the success of a species to maintain itself in a new environment have been poorly studied to date. Here we examine this question in a large wood-boring beetle Cacosceles newmannii (Cerambycidae), that was recently found thriving on a newly colonized host plant. Using 16S metabarcoding, we assessed the gut bacterial community composition of larvae collected in an infested field and in "common garden" conditions, fed under laboratory-controlled conditions on four either suspected or known hosts (sugarcane, tea tree, wattle, and eucalyptus). We analysed microbiome variation (i.e. diversity and differentiation), measured fitness-related larval growth, and studied host plant lignin and cellulose contents, since their degradation is especially challenging for wood-boring insects. We show that sugarcane seems to be a much more favourable host for larval growth. Bacterial diversity level was the highest in field-collected larvae, whereas lab-reared larvae fed on sugarcane showed a relatively low level of diversity but very specific bacterial variants. Bacterial communities were mainly dominated by Proteobacteria, but were significantly different between sugarcane-fed lab-reared larvae and any other hosts or field-collected larvae. We identified changes in the gut microbiome associated with different hosts over a short time frame, which support the hypothesis of a role of the microbiome in host switches.

Medication-Facilitated Advanced Airway Management with First-Line Use of a Supraglottic Device - A One-Year Quality Assurance Review.

INTRODUCTION: Airway management is a controversial topic in modern Emergency Medical Services (EMS) systems. Among many concerns regarding endotracheal intubation (ETI), unrecognized esophageal intubation and observations of unfavorable neurologic outcomes in some studies raise the question of whether alternative airway techniques should be first-line in EMS airway management protocols. Supraglottic airway devices (SADs) are simpler to use, provide reliable oxygenation and ventilation, and may thus be an alternative first-line airway device for paramedics. In 2019, Alachua County Fire Rescue (ACFR; Alachua, Florida USA) introduced a novel protocol for advanced airway management emphasizing first-line use of a second-generation SAD (i-gel) for patients requiring medication-facilitated airway management (referred to as "rapid sequence airway" [RSA] protocol). STUDY OBJECTIVE: This was a one-year quality assurance review of care provided under the RSA protocol looking at compliance and first-pass success rate of first-line SAD use. METHODS: Records were obtained from the agency's electronic medical record (EMR), searching for the use of the RSA protocol, advanced airway devices, or either ketamine or rocuronium. If available, hospital follow-up data regarding patient condition and emergency department (ED) airway exchange were obtained. RESULTS: During the first year, 33 advanced airway attempts were made under the protocol by 23 paramedics. Overall, compliance with the airway device sequence as specified in the protocol was 72.7%. When ETI was non-compliantly used as first-line airway device, the first-pass success rate was 44.4% compared to 87.5% with adherence to first-line SAD use. All prehospital SADs were exchanged in the ED in a delayed fashion and almost exclusively per physician preference alone. In no case was the SAD exchanged for suspected dislodgement evidenced by lack of capnography. CONCLUSION: First-line use of a SAD was associated with a high first-pass attempt success rate in a real-life cohort of prehospital advanced airway encounters. No SAD required emergent exchange upon hospital arrival.

Unrecognized cardiac arrests: A one-year review of audio from emergency medical dispatch calls.

OBJECTIVES: Immediate recognition of out-of-hospital cardiac arrest (OHCA) by Emergency Medical Dispatch (EMD) operators is crucial to facilitate timely initiation of telephone cardiopulmonary resuscitation (T-CPR) and to enable the appropriate level of Emergency Medical Services (EMS) response. The goal of this study was to identify patterns that can increase EMD-level recognition of cardiac arrests prior to EMS arrival. METHODS: The Combined Communications Center in Alachua County, Florida provided audio recordings of all emergency calls from January 1, 2018 to November 16, 2018 dispatched as a chief complaint other than OHCA, but later identified as cardiac arrest. A multi-disciplinary medical team transcribed and analyzed the calls to determine common themes and trends. RESULTS: Out of an initial 81 calls meeting inclusion criteria, 69 were immediately recognized as OHCA by EMDs, leaving 12 calls of unrecognized OHCA. In 11 of 12 calls respiratory issues were described to EMD. In 10 of 12 calls the subject was described as unconscious, and in the other 2 calls, the subject lost consciousness during the call. CONCLUSIONS: Lack of recognition of OHCA by EMD occurred in most calls due to difficulty communicating the subject's respiratory status. Further emphasis should be placed on identifying non-viable respirations in unconscious patients in EMD training and algorithms to increase recognition of OHCA and initiation of T-CPR. A multi-year review of a comparable dataset from geographically and socioeconomically diverse regions in the United States can validate and expand these preliminary trends.

Probing Gluon Spin-Momentum Correlations in Transversely Polarized Protons through Midrapidity Isolated Direct Photons in p

Studying spin-momentum correlations in hadronic collisions offers a glimpse into a three-dimensional picture of proton structure. The transverse single-spin asymmetry for midrapidity isolated direct photons in p^{↑}+p collisions at sqrt[s]=200 GeV is measured with the PHENIX detector at the Relativistic Heavy Ion Collider (RHIC). Because direct photons in particular are produced from the hard scattering and do not interact via the strong force, this measurement is a clean probe of initial-state spin-momentum correlations inside the proton and is in particular sensitive to gluon interference effects within the proton. This is the first time direct photons have been used as a probe of spin-momentum correlations at RHIC. The uncertainties on the results are a 50-fold improvement with respect to those of the one prior measurement for the same observable, from the Fermilab E704 experiment. These results constrain gluon spin-momentum correlations in transversely polarized protons.

Exceptional increases in fluvial sediment fluxes in a warmer and wetter High Mountain Asia.

Rivers originating in High Mountain Asia are crucial lifelines for one-third of the world's population. These fragile headwaters are now experiencing amplified climate change, glacier melt, and permafrost thaw. Observational data from 28 headwater basins demonstrate substantial increases in both annual runoff and annual sediment fluxes across the past six decades. The increases are accelerating from the mid-1990s in response to a warmer and wetter climate. The total sediment flux from High Mountain Asia is projected to more than double by 2050 under an extreme climate change scenario. These findings have far-reaching implications for the region's hydropower, food, and environmental security.

DNA barcoding for bio-surveillance of emerging pests and species identification in Afrotropical Prioninae (Coleoptera, Cerambycidae).

DNA barcoding has been succesfully used for bio-surveillance of forest and agricultural pests in temperate areas, but has few applications in the tropics and particulary in Africa. Cacosceles newmannii (Coleoptera: Cerambycidae) is a Prioninae species that is locally causing extensive damage in commercially-grown sugarcane in the KwaZulu-Natal Province in South Africa. Due to the risk of spread of this species to the rest of southern Africa and to other sugarcane growing regions, clear and easy identification of this pest is critical for monitoring and for phytosanitary services. The genus Cacosceles Newman, 1838 includes four species, most being very similar in morphology. The damaging stage of the species is the larva, which is inherently difficult to distinguish morphologically from other Cerambycidae species. A tool for rapid and reliable identification of this species was needed by plant protection and quarantine agencies to monitor its potential abundance and spread. Here, we provide newly-generated barcodes for C. newmannii that can be used to reliably identify any life stage, even by non-trained taxonomists. In addition, we compiled a curated DNA barcoding reference library for 70 specimens of 20 named species of Afrotropical Prioninae to evaluate DNA barcoding as a valid tool to identify them. We also assessed the level of deeply conspecific mitochondrial lineages. Sequences were assigned to 42 different Barcode Index Numbers (BINs), 28 of which were new to BOLD. Out of the 20 named species barcoded, 11 (52.4%) had their own unique Barcode Index Number (BIN). Eight species (38.1%) showed multiple BINs with no morphological differentiation. Amongst them, C. newmannii showed two highly divergent genetic clusters which co-occur sympatrically, but further investigation is required to test whether they could represent new cryptic species.

The Impact of Water Sanitation and Hygiene (WASH) Improvements on Hand Hygiene at Two Liberian Hospitals during the Recovery Phase of an Ebola Epidemic.

Fourteen years of civil war left Liberia with crumbling infrastructure and one of the weakest health systems in the world. The 2014-2015 Ebola virus disease (EVD) outbreak exposed the vulnerabilities of the Liberian health system. Findings from the EVD outbreak highlighted the lack of infection prevention and control (IPC) practices, exacerbated by a lack of essential services such as water, sanitation, and hygiene (WASH) in healthcare facilities. The objective of this intervention was to improve IPC practice through comprehensive WASH renovations conducted at two hospitals in Liberia, prioritized by the Ministry of Health (MOH). The completion of renovations was tracked along with the impact of improvements on hand hygiene (HH) practice audits of healthcare workers pre- and post-intervention. An occurrence of overall HH practice was defined as the healthcare worker practicing compliant HH before and after the care for a single patient encounter. Liberia Government Hospital Bomi (LGH Bomi) and St. Timothy Government Hospital (St. Timothy) achieved World Health Organization (WHO) minimum global standards for environmental health in healthcare facilities as well as Liberian national standards. Healthcare worker (HCW) overall hand hygiene compliance improved from 36% (2016) to 89% (2018) at LGH Bomi hospital and from 86% (2016) to 88% (2018) at St. Timothy hospital. Improved WASH services and IPC practices in resource-limited healthcare settings are possible if significant holistic WASH infrastructure investments are made in these settings.

Characteristics of Ebola Virus Disease Survivor Blood and Semen in Liberia: Serology and Reverse Transcription Polymerase Chain Reaction (RT-PCR).

INTRODUCTION: Ebola virus (EBOV), species Zaire ebolavirus, may persist in the semen of male survivors of Ebola virus disease (EVD). We conducted a study of male survivors of the 2014-2016 EVD outbreak in Liberia and evaluated their immune responses to EBOV. We report here findings from the serologic testing of blood for EBOV-specific antibodies, molecular testing for EBOV in blood and semen, and serologic testing of peripheral blood mononuclear cells (PBMCs) in a subset of study participants. METHODS: We tested for EBOV RNA in blood by quantitative reverse transcription polymerase chain reaction (qRT-PCR), and for anti-EBOV-specific immunoglobulin M (IgM) and immunoglobulin G (IgG) antibodies by enzyme-linked immunosorbent assay (ELISA) for 126 study participants. We performed PBMC analysis on a subgroup of 26 IgG-negative participants. RESULTS: All 126 participants tested negative for EBOV RNA in blood by qRT-PCR. The blood of 26 participants tested negative for EBOV-specific IgG antibodies by ELISA. PBMCs were collected from 23/26 EBOV IgG-negative participants. Of these, 1/23 participants had PBMCs that produced anti-EBOV-specific IgG antibodies upon stimulation with EBOV-specific glycoprotein (GP) and nucleoprotein (NP) antigens. CONCLUSIONS: The blood of EVD survivors, collected when they did not have symptoms meeting the case definition for acute or relapsed EVD, is unlikely to pose a risk for EBOV transmission. We identified 1 IgM/IgG negative participant who had PBMCs that produced anti-EBOV-specific antibodies upon stimulation. Immunogenicity following acute EBOV infection may exist along a spectrum, and absence of antibody response should not be exclusionary in determining an individual's status as a survivor of EVD.

Correction: Synthesis and structural characterization of CO2-soluble oxidizers [Bu4N]BrO3 and [Bu4N]ClO3 and their dissolution in cosolvent-modified CO2 for reservoir applications.

[This corrects the article DOI: 10.1039/D0RA09563J.].

Systems thinking for health emergencies: use of process mapping during outbreak response.

Process mapping is a systems thinking approach used to understand, analyse and optimise processes within complex systems. We aim to demonstrate how this methodology can be applied during disease outbreaks to strengthen response and health systems. Process mapping exercises were conducted during three unique emerging disease outbreak contexts with different: mode of transmission, size, and health system infrastructure. System functioning improved considerably in each country. In Sierra Leone, laboratory testing was accelerated from 6 days to within 24 hours. In the Democratic Republic of Congo, time to suspected case notification reduced from 7 to 3 days. In Nigeria, key data reached the national level in 48 hours instead of 5 days. Our research shows that despite the chaos and complexities associated with emerging pathogen outbreaks, the implementation of a process mapping exercise can address immediate response priorities while simultaneously strengthening components of a health system.

The development of an improved artificial diet for the mass rearing of Eldana saccharina Walker (Lepidoptera: Pyralidae).

BACKGROUND: This study determined the nutrient requirements of Eldana saccharina Walker (Lepidoptera: Pyralidae), a serious sugarcane pest in South Africa, to develop a more efficient artificial diet for mass-rearing purposes for sterile moth production. Diets tested consisted of a minimum specification (MS) diet representing a diet formulated according to the minimum specification of a summary of published diets, which yielded satisfactory results; an ideal amino acid profile (IAAP) diet, where amino acid composition was based on the profile of amino acids in the 2nd (IAAP2) and 5th /6th (IAAP5/6) instar larvae; and lastly two diets based on the nutrient composition of the natural diet of the insects, papyrus (PAP) and sugarcane (SC). Six treatments with 50 replications were randomly allotted to 300 25 mL plastic screw-top vials. The diet (15 mL) was dispensed into each vial and inoculated with two freshly hatched larvae. Larvae, pupae, and moths were harvested at 28 days after inoculation. Overall survivability, pupal weight, sex ratio, and rate of development was determined and compared with the diet currently in use at the South African Sugarcane Research Institute (CON). Physical characteristics of the diets such as the pH and the water-holding capacity of the diets were also determined. RESULTS: The natural diets (PAP and SC) were not viable as they did not yield any results. Survivability was significantly higher (78%) for the MS diet whilst IAAP2 and IAAP5/6 yielded the second highest survivability (74%) compared to CON (68%). There were no differences in male pupal weights between all treatment diets, as was the case for female pupae. Within dietary treatments, female pupae were heavier than male pupae for all treatment diets. CON (1.0: 1.6) produced significantly less male than female pupae with MS (1.0: 1.2), IAAP2 (1.0: 1.0) and IAAP5/6 (1.0: 1.1) all producing equal amounts of male and female pupae. The MS diet (16%) yielded fourfold the number of moths after 28 days compared to CON (4%) and IAAP2 (4%) diets. IAAP5/6 yielded no moths after 28 days. The life stages thus developed fastest in the MS diet. The pH of all treatment diets remained stable for the entire duration of the trial. No biological contamination was observed through all diets. Differences in water-holding capacity were observed between most diets with PAP and SC losing the most moisture whilst the MS and IAAP2 diets retained the most moisture. CONCLUSION: The MS diet most closely represented the nutrient requirements of E. saccharina, leading to its faster development on this formulation, which could be readily applied for large-scale production of this lepidopteran pest as an aid in the mass rearing of sterile males as part of the integrated pest management plan. © 2020 Society of Chemical Industry.

Global trends in water and sediment fluxes of the world's large rivers.

Water and sediment transport from rivers to oceans is of primary importance in global geochemical cycle. Against the background of global change, this study examines the changes in water and sediment fluxes and their drivers for 4307 large rivers worldwide (basin area ≥1000 km2) based on the longest available records. Here we find that 24% of the world's large rivers experienced significant changes in water flux and 40% in sediment flux, most notably declining trends in water and sediment fluxes in Asia's large rivers and an increasing trend in suspended sediment concentrations in the Amazon River. In particular, nine binary patterns of changes in water-sediment fluxes are interpreted in terms of climate change and human impacts. The change of precipitation is found significantly correlated to the change of water flux in 71% of the world's large rivers, while dam operation and irrigation rather control the change of sediment flux in intensively managed catchments. Globally, the annual water flux from rivers to sea of the recent years remained stable compared with the long-time average annual value, while the sediment flux has decreased by 20.8%.

Synthesis and structural characterization of CO2-soluble oxidizers [Bu4N]BrO3 and [Bu4N]ClO3 and their dissolution in cosolvent-modified CO2 for reservoir applications.

CO2 utilization in upsteam oil and gas applications requires CO2-soluble additives such as polymers, surfactants, and other components. Here we report the facile synthesis of CO2-soluble oxidizers composed of judiciously selected organic cations paired with oxidizing anions. [Bu4N]BrO3 and [Bu4N]ClO3 are prepared using a double displacement synthetic strategy, whereby the crystalline product is readily obtained in high yield and structurally characterized using single-crystal X-ray diffraction. The facility of the approach is demonstrated through the preparation of several additional alkylammonium bromate compounds. Static solubility studies using a high-pressure cell with viewing windows showed that tetrabutylammonium compounds could be solubilized using cosolvent-modified CO2. Using 4 mol% ethanol as cosolvent, >3 mM [Bu4N]BrO3 could be dissolved in CO2, while ∼0.75 mM [Bu4N]ClO3 could be dissolved in the same solvent system. The solubility properties of [Bu4N]BrO3 along with its thermal stability up to ∼200 °C suggest that it is a promising oilfield oxidizer that can be utilized in subterranean CO2 applications.

The Effect of Oxygen Limitation on a Xylophagous Insect's Heat Tolerance Is Influenced by Life-Stage Through Variation in Aerobic Scope and Respiratory Anatomy.

Temperature has a profound impact on insect fitness and performance via metabolic, enzymatic or chemical reaction rate effects. However, oxygen availability can interact with these thermal responses in complex and often poorly understood ways, especially in hypoxia-adapted species. Here we test the hypothesis that thermal limits are reduced under low oxygen availability - such as might happen when key life-stages reside within plants - but also extend this test to attempt to explain that the magnitude of the effect of hypoxia depends on variation in key respiration-related parameters such as aerobic scope and respiratory morphology. Using two life-stages of a xylophagous cerambycid beetle, Cacosceles (Zelogenes) newmannii we assessed oxygen-limitation effects on metabolic performance and thermal limits. We complement these physiological assessments with high-resolution 3D (micro-computed tomography scan) morphometry in both life-stages. Results showed that although larvae and adults have similar critical thermal maxima (CTmax) under normoxia, hypoxia reduces metabolic rate in adults to a greater extent than it does in larvae, thus reducing aerobic scope in the former far more markedly. In separate experiments, we also show that adults defend a tracheal oxygen (critical) setpoint more consistently than do larvae, indicated by switching between discontinuous gas exchange cycles (DGC) and continuous respiratory patterns under experimentally manipulated oxygen levels. These effects can be explained by the fact that the volume of respiratory anatomy is positively correlated with body mass in adults but is apparently size-invariant in larvae. Thus, the two life-stages of C. newmannii display key differences in respiratory structure and function that can explain the magnitude of the effect of hypoxia on upper thermal limits.