Low Load Research Articles

Diagnosing gastrointestinal infections based on cycle threshold cut-offs of PCR.

This study compared the performance of molecular vs stool culture assays for gastrointestinal infection (GII) detection, with focus on defining cycle threshold (Ct) cut-off values for positive culture results. A total of 6,000 records of patients with suspected GII between October 2022 and February 2023 and registered at Clalit HealthCare Services in Haifa, Israel, were reviewed. Stool samples were collected from all patients with suspected GII. PCR was performed with the Seegene Allplex GI-Bacteria (I) assay kit. PCR-positive samples were cultured on bacteria-specific agar media. Out of 356 PCR-positive samples, 196 (55.1%) were culture-positive. Significant differences were noted between the mean Ct of culture-positive vs culture-negative samples for Shigella spp. (P < 0.0001), E. coli O157 (P = 0.0001), and Campylobacter spp. (P = 0.004). Shigella had the lowest Ct cutoff (27.14). Negative culture results for PCR-positive samples may result from low bacterial load. At the same time, false-positive PCR results may exist. Thus, PCR result should be considered along with clinical presentation and with Ct value consideration.IMPORTANCEGII diagnostic procedures have shifted from traditional- to molecular-based assays, which may increase missdiagnosis due to the high PCR sensitivity and false positives. This study suggests to consider a Ct threshold for each pathogen in order to reduce inaccurate diagnosis. Alternatively, culture should be performed for PCR-positive samples.

A Randomized, Blinded, Vehicle-Controlled Dose-Ranging Study to Evaluate and Characterize Remdesivir Efficacy Against Ebola Virus in Rhesus Macaques

Ebola virus (EBOV) causes severe disease in humans, with mortality as high as 90%. The small-molecule antiviral drug remdesivir (RDV) has demonstrated a survival benefit in EBOV-exposed rhesus macaques. Here, we characterize the efficacy of multiple intravenous RDV dosing regimens on survival of rhesus macaques 42 days after intramuscular EBOV exposure. Thirty rhesus macaques underwent surgical implantation of telemetry devices for the fine-scale monitoring of body temperature and activity, as well as central venous catheters, to enable treatment administration and blood collection. Treatment, consisting of a loading dose of RDV followed by once-daily maintenance doses for 11 days, was initiated 4 days after virus exposure when all animals were exhibiting disease signs consistent with incipient EBOV disease as well as quantifiable levels of EBOV RNA in plasma. In the RDV treatment groups receiving loading/maintenance doses of 5/2.5 mg/kg, 10/5 mg/kg, and 20/10 mg/kg, a total of 6 of 8 (75%), 7 of 8 (87.5%), and 5 of 7 (71.4%) animals survived, respectively. In the vehicle control group, one of seven animals (14.3%) survived. The improved survival rate compared to the control group was statistically significant only for the 10/5 mg/kg RDV treatment group. This treatment regimen also resulted in a significantly lower systemic viral load compared to the vehicle control after a single RDV treatment. All three RDV regimens produced a significantly lower systemic viral load after two treatments. For most animals, RDV treatment, regardless of dose, resulted in the amelioration of many of the clinical–pathological changes associated with EBOV disease in this model.

Mechanical and chemical characterization of biochar-reinforced polystyrene composites

This study investigates the chemical interactions and mechanical characteristics of composites made of polystyrene reinforced with biochar. Polystyrene-based resin (PBR) was combined with plantain peel-derived biochar in different weight ratios (10%, 20%, 30%, and 40%). The Brinell hardness test, Fourier transform infrared spectroscopy (FTIR), scanning electron microscopy (SEM), and energy dispersive X-ray spectroscopy (EDS) were used to evaluate the properties of the composites. The results of the hardness test showed a non-monotonic pattern, with hardness first decreasing at low biochar loadings (10% and 20%), then significantly increasing at 30% biochar. At 40% biochar, the hardness then somewhat dropped, indicating that around 30% filler is the optimal biochar level for hardness. As the biochar loading increased, FTIR measurement showed that hydroxyl groups (-OH) were introduced and that the intensity of carbonyl groups (C = O) increased. According to SEM analysis, a uniform surface was found at lower biochar loadings, but at larger biochar contents, the surface became irregular and rough. In addition to providing insights into the chemical interactions at the interface between the biochar and the polymer matrix, these findings demonstrate the possibility of incorporating biochar to alter the mechanical properties of PBR.

Complement C3d enables cell-mediated immunity capable of distinguishing spontaneously transformed from nontransformed cells

Immune surveillance depends in part on the recognition of peptide variants by T cell antigen receptors. Given that both normal B cells and malignant B cells accumulate mutations we chose a murine model of multiple myeloma to test conditions to induce cell-mediated immunity targeting malignant plasma cell (PC) clones but sparing of normal PCs. Revealing a previously unknown function for intracellular C3d, we found that C3d engaged T cell responses against malignant PC in the bone marrow of mice that had developed multiple myeloma spontaneously. Our results show that C3d internalized by cells augments immune surveillance by several mechanisms. In one, C3d induces a master transcription regulator, E2f1, to increase the expression of long noncoding (lnc) RNAs, to generate peptides for MHC-I presentation, and increase MHC-I expression. In another, C3d increases expression of RNAs encoding ribosomal proteins linked to processing of defective ribosomal products that arise from noncanonical translation and known to promote immunosurveillance. Cancer cells are uniquely susceptible to increased expression and presentation of mutant peptides given the extent of protein misfolding and accumulation of somatic mutations. Accordingly, although C3d can be internalized by any cell, C3d preferentially targets malignant clones by evoking specific T cell-mediated immunity and sparing most nontransformed polyclonal B cells and PC with lower mutation loads. Malignant PC deletion was blocked by cyclosporin or by CD8 depletion confirming that endogenous T cells mediated malignant clone clearance. Besides the potential for therapeutic application our results highlight how intracellular C3d modifies cellular metabolism to augment immune surveillance.

Dynamic calibration of self-efficacy to cognitive load: the longitudinal mediation effect of state anxiety

BackgroundPrevious research has shown that higher self-efficacy predicts lower cognitive load. Nevertheless, there is limited research exploring the dynamic calibration phenomenon of cognitive resources by self-efficacy during task execution through experimental methods.MethodsThis study elucidates the relationships and longitudinal mediating effects among self-efficacy, state anxiety, and cognitive load through two studies that employed convenience sampling. Study 1, which aims to provide a comprehensive theoretical understanding of the research question, is an interview study that examines the prevalence of fluctuations in self-efficacy among 22 university students through an in-depth interview. On the other hand, study 2 reveals further causal relationships through experimental methods. It adopts a 3 (repeated measures: first time, second time, third time) × 2 (conditions: feedback group, non-feedback group) mixed design by 86 participants, utilizing a false feedback paradigm to manipulate participants’ self-efficacy, with the task of the experiment being emotion recognition.ResultsThe results demonstrate that, compared to the non-feedback group, false feedback can successfully manipulate the self-efficacy of the participants, and the data from the feedback group further reveals the multilevel mediating role of state anxiety in the process of self-efficacy influencing cognitive load.ConclusionIn general, the findings from two studies suggest that the enhancement of college students’ self-efficacy during task execution can reduce their state anxiety, which in turn can further alleviate cognitive load.

Valine potentiates cefoperazone-sulbactam to kill methicillin-resistant Staphylococcus aureus.

Methicillin-resistant Staphylococcus aureus (MRSA) is possibly the most infamous example of antibiotic resistance and new antibiotics are urgently needed to control it. The present study used metabolic state-reprogramming approach to identify an ideal biomarker as an antibiotic adjuvant for reversing the metabolic state of MRSA. The most repressed valine was identified as the adjuvant. Exogenous valine most effectively potentiated cefoperazone-sulbactam (SCF) to kill MRSA in vitro and in vivo. Viability of 18 clinical MRSA isolates was reduced by the top 276.64-fold in the presence of valine and SCF. In mouse models, lower bacterial load in liver, spleen, kidney, thigh, and higher survival were determined in the SCF + valine than valine or SCF alone. Valine promoted MRSA to increase SCF uptake that overcomes the efflux and enzymatic hydrolysis. It also extended the PAE of SCF. These occur because valine activates the pyruvate cycle to elevate proton motive force by NADH and increases membrane permeability by lauric acid. Therefore, the combination of valine and SCF is a new drug candidate effective against MRSA.

Impact of Optimization Variables on Fuel Consumption in Large Four-Stroke Diesel Marine Engines with Electrically Divided Turbochargers

The objective of this study is to understand how each variable impacts the optimal configuration of a marine diesel engine equipped with an electric hybrid air-charging system that allows energy assistance and recovery. The aim is to minimize CO2 emissions by reducing fuel consumption. The hybrid system offers flexibility in adjusting parameters from both the engine and air-charging system. It is compared with the baseline engine, which uses a free-floating turbocharger. The results show a significant improvement at low engine loads, where the baseline engine struggles to provide sufficient air. While turbine speed has little influence, compressor power reduces fuel consumption at low loads. However, at mid loads, resizing the turbomachine is necessary for further improvements. At high loads, full optimization of all variables is required to reduce fuel consumption. The electric hybrid system is particularly effective in tugboat-like conditions, where low loads dominate, but less impactful for ro-pax ferries. Despite the potential of the hybrid system, a fully optimized turbocharger could provide greater benefits due to reduced losses. Future studies could explore combining the adaptability of the hybrid system with a highly efficient turbocharger to reduce emissions across all load conditions.

Rotomolded polypropylene‐ignimbrite composites: Giving a second life to mineral dust wastes

AbstractThe possibility of rotomolding polypropylene (PP) composites with high loadings of a silica‐based dust of ignimbrite, a byproduct of volcanic stone extraction is demonstrated. This study aims to establish the properties of composites with various ratios of mineral dust as a filler in PP matrices at loadings from 5 to 30 wt%, ultimately transforming mining residues into a valuable resource for composite production and creating a value chain around the traditional mining industry. Once the composites were obtained, they were subjected to several characterization techniques to comprehensively assess their mechanical and thermal properties. In general, a high percentage of ignimbrite powder has resulted in a reduction in the mechanical properties of neat PP, although no significant changes were observed for composites at lower loadings. Furthermore, the incorporation of this mineral material modified the thermal properties of the PP, enhancing its thermal stability. The blending of the matrix and filler resulted in a reduction in both the melting crystallization temperatures for highly‐filled composites. Rotomolded items with good aesthetics, with stone‐like appearance, were obtained without any modification on the mineral dust or even without any melt compounding, therefore not increasing the energy consumption during the composites production.Highlights Composites production is a suitable strategy for valorization of mineral residues. Welded ignimbrite residual dust has been used for the first time in composites. Mineral dust has been successfully used in composites obtained by rotomolding. Polypropylene with up to 30% of the stone dust can be processed. Good aesthetics and mechanical features can be obtained with mineral wastes.

Oxidative coupling of N-nitrosoanilines with substituted allyl alcohols under rhodium (III) catalysis

Rhodium(III) catalysis has been used for C-H activation of N-nitrosoanilines with substituted allyl alcohols. This method provides an efficient synthesis of the functional N-nitroso ortho β-aryl aldehydes and ketones with low catalyst loading, high functional group tolerance, and superior reactivity of allyl alcohols toward N-nitrosoanilines. We demonstrated that reaction also proceeds through the one-pot synthesis of N-nitrosoaniline, followed by subsequent, C-H activation. The protocol was also feasible with acyrlaldehyde and methyl vinyl ketone which furnished the same oxidative N-nitroso coupling product.

Rechargeable Lithium-Hydrogen Gas Batteries.

The global clean energy transition and carbon neutrality call for developing high-performance batteries. Here we report a rechargeable lithium metal - catalytic hydrogen gas (Li-H) battery utilizing two of the lightest elements, Li and H. The Li-H battery operates through redox of H2/H+ on the cathode and Li/Li+ on the anode. The universal properties of the H2 cathode enable the battery to demonstrate attractive electrochemical performance, including high theoretical specific energy up to 2825 Wh kg-1, discharge voltage of 3 V, round-trip efficiency of 99.7 %, reversible areal capacity of 5-20 mAh cm-2, all-climate characteristics with a wide operational temperature range of -20-80 °C, and high utilization of active materials. A rechargeable anode-free Li-H battery is further constructed by plating Li metal from cost-effective lithium salts under a low catalyst loading of <0.1 mg cm-2. This work presents a route to design batteries based on catalytic hydrogen gas cathode for high-performance energy storage applications.

Rechargeable Lithium‐Hydrogen Gas Batteries

AbstractThe global clean energy transition and carbon neutrality call for developing high‐performance batteries. Here we report a rechargeable lithium metal ‐ catalytic hydrogen gas (Li−H) battery utilizing two of the lightest elements, Li and H. The Li−H battery operates through redox of H2/H+ on the cathode and Li/Li+ on the anode. The universal properties of the H2 cathode enable the battery to demonstrate attractive electrochemical performance, including high theoretical specific energy up to 2825 Wh kg−1, discharge voltage of 3 V, round‐trip efficiency of 99.7 %, reversible areal capacity of 5–20 mAh cm−2, all‐climate characteristics with a wide operational temperature range of −20–80 °C, and high utilization of active materials. A rechargeable anode‐free Li−H battery is further constructed by plating Li metal from cost‐effective lithium salts under a low catalyst loading of &lt;0.1 mg cm−2. This work presents a route to design batteries based on catalytic hydrogen gas cathode for high‐performance energy storage applications.

Influence of Oestradiol Fluctuations in the Menstrual Cycle on Respiratory Exchange Ratio at Different Exercise Intensities: A Systematic Review, Meta-Analysis and Pooled-Data Analysis

Background: Oestradiol has been implicated as a factor in substrate utilisation in male and mouse studies but the effect of acute changes during the menstrual cycle is yet to be fully understood. Objective: To determine the role of oestradiol in respiratory exchange ratio (RER) during exercise at various intensities. Methods: This systematic review was conducted and reported in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) statement. From inception to November 2023, four online databases (Cochrane, SPORTDiscus, MEDline and Web of Science) were searched for relevant articles. Studies that reported a resting oestradiol measurement in naturally menstruating women with exercise at a percentage of maximal aerobic capacity (%V˙O2max) were included. Mean and standard deviation for oestradiol, RER and exercise intensity were extracted and study quality assessed using a modified Downs and Black checklist. Risk of bias was assessed using I2 measure of heterogeneity and Egger’s regression test, assessment of bias from methodological quality was identified by sensitivity analysis. Eligible datasets were extracted for pairwise comparisons within a meta-analysis and correlation between change in oestradiol and change in RER. Data were also pooled to produce a mean and standard deviation for RER for menstrual stage and for low and high oestradiol groups. Results: Twenty-four articles were identified, over 50% were identified as high quality. Sixteen articles included datasets eligible for meta-analysis. Eleven articles utilised a submaximal constant-load exercise intensity, finding a standardised mean difference of − 0.09 ([CI: −0.35–0.17], p = 0.5) suggesting no effect of menstrual phase on constant-load exercise RER. In six articles using incremental exercise tests to exhaustion, a standardised mean difference of 0.60 ([CI 0.00–1.19], p = 0.05) was identified towards a higher maximal RER attained in follicular compared to luteal phase. There was no correlation (R = −0.26, p = 0.2) between change in oestradiol and change in RER between phases. All 24 articles, totalling 650 participants, were included in pooled analysis. When grouped by menstrual cycle phase or when grouped by oestradiol levels, RER was higher in the follicular phase than the luteal phase at low and high constant load exercise intensities. Discussion: Findings from the pooled-analysis and meta-analysis suggest that there may be menstrual cycle phase differences in RER that are intensity dependent. These differences may be related to sex hormone levels, but this was not supported by evidence of correlation between differences in RER and differences in oestradiol. At present, it remains best practice to assess performance in the same menstrual cycle phase if seeking to assess change from baseline.

Ecological potential of soils of old-growth natural forests Skole Beskydy (Ukrainian Carpathians)

The ecological potential of the soils of natural old-growth forests is analyzed. It has been found that the upper horizon of brown mountain-forest soils is characterized by excellent indicators of total porosity (63,63 %), soil water permeability (3,08 cm⸱min-¹), soil bulk density (0,88 g⸱cm-³) and catalase enzyme activity (4,9 cm3 O2 per 1 g of soil per 1 min). The results indicate excellent ecological potential of the soils, which allows using their indicators as a reference for restoring soil cover under the forest ecosystems of the Skole Beskydy. The recreational and agrogenic impact on soils in the mountainous region was also analyzed. It was found that the upper humus-accumulative horizon suffers the most from plowing, trampling by livestock, and damage by erosion processes caused by prolonged recreational use. While cattle grazing is seasonal, the impact of recreationists is increasing and corresponds to stages II and IV of recreational degradation, soils under arable land are subject to the greatest anthropogenic impact in terms of time interval due to the transfer of the upper horizons downwards, and vice versa. The processes of soil recovery under pasture, after the removal of agrogenic load, are much faster than under plowed areas. Arable land undergoes several successive stages of recovery (arable land → fallow land → shrub vegetation → woody vegetation I (mainly gray alder and birch-aspen stands) → woody vegetation II (indigenous forest-forming species of the region), where the process itself takes 150-200 years. Третє місце серед досліджуваних ділянок посідають туристичні шляхи. Зазначимо, що само відновлення стежок відбувається здебільшого на початку ІІ стадії дегресії, ІV стадія потребує реконструкції, а період відновлення сягає кілька десятків років. The analysis of water-physical properties under old-growth natural stands as a benchmark shows that the density of soil structure increases by 1,2 times on the category II trail and 1.5 times on the category IV trail Based on the results of the analysis of data made within the soil profile, it was found that under pasture the soil is compacted to a depth of 10 cm, under arable land - to the depth of plowing, and on trails the compaction is 5-10 cm in the initial stages and reaches 30 cm to the depth of the parent rock at the IV stage of recreational degradation. Systematic monitoring of the tourist routes and ecological trails of the Skole Beskydy National Park will help prevent degradation processes in a timely manner. In the areas with low recreational load, it is proposed to mark the tourist trails, and for safety and convenience, to install bridges with handrails over mountain streams. On the trails of the IV category, it is necessary to mark the routes, limit the access of recreationists in bad weather to the outstanding attractions. Key words: еcological potential of soils; old-growth natural forests; trail; land use; brown mountain-forest soils; forest floor; mountainous region.

Is the existence of a relict primate in the Far North possible?

The author sets out to generalize the existing information about a humanoid creature in the Russian Far North by analyzing the reports of local residents, travelers, and researchers, as well as by studying local legends and folklore tales. The data is evaluated from the perspectives of folklore studies and the theory of testimonial evidence. The reliability of this evidence, which resonates well with the traces of prehistoric human activity found in Yakutia, cannot be fully ruled out. Given the low anthropogenic load and the scarcity of knowledge about these places, the possibility of the existence of animals, which are unknown to science, cannot be refuted. The author evaluates the theoretical possibility of the existence of a highly developed primate in northern and other areas of the planet, which cannot be accessed by conventional methods of zoology.

Presence of Trypanosoma cruzi (TcI) in different tissues of Didelphis virginiana from the metropolitan area of Merida, southeastern Mexico: Epidemiological relevance and implications for non-vector transmission routes.

Trypanosoma cruzi is mainly transmitted to mammals by vectors, but other transmission routes exist. Opossums can harbor the infectious form of the parasite in their anal glands, underscoring their potential role in non-vectorial transmission. In Mexico, Didelphis virginiana and D. marsupialis are the main opossum species. While T. cruzi has been detected in the anal gland secretions of various opossum species, their infectivity has only been confirmed in D. marsupialis and D. albiventris. Vertical transmission has also been proposed in D. virginiana. However, if this occurs in opossums, it remains unclear whether it happens during pregnancy or lactation. Our objective was to investigate the possible contribution of urban opossums to non-vectorial transmission of T. cruzi in the metropolitan area of Merida, Yucatan, in southeastern Mexico. Blood, anal gland secretions, and milk were collected from opossums captured in Merida, Mexico, all identified as D. virginiana using taxonomic keys and Cytb sequencing. By PCR, T. cruzi was detected in 16/102 opossums (15.69%) in at least one type of sample. The prevalence was 14.71% (15/102) in blood and 0.98% (1/102) in anal gland secretions. 1/22 milk samples (4.55%) tested positive. Blood of 37 offspring from T. cruzi-positive mothers was collected and tested negative. qPCR revealed that females with offspring tended to have lower parasite load in blood compared to females without offspring and males. Genotyping of the parasite through multiplex PCR revealed only the DTU TcI. This study agrees with previous works where D. virginiana was the most abundant opossum species in urban areas in southeastern Mexico and confirms that it is associated with TcI. Detection of T. cruzi in a sample of anal gland secretions underscores the potential risk represented by D. virginiana in non-vectorial transmission in urban areas of southeastern Mexico. Detection in the milk of a lactating female, along with the observed tendency towards a lower parasite load in females with offspring, highlight the importance of further investigating vertical transmission in D. virginiana.

Combined mutations in nonstructural protein 14, envelope, and membrane proteins mitigate the neuropathogenicity of SARS-CoV-2 Omicron BA.1 in K18-hACE2 mice.

Inoculation of transgenic mice expressing human angiotensin-converting enzyme 2 (hACE2) with SARS-CoV-2 often leads to a fatal brain infection. Omicron BA.1 variant, however, was found to be non-lethal in this model. Here, we systematically assessed the effect of individual mutations of Omicron BA.1 on the pathogenicity of the virus in hACE2 transgenic mice and found that combination of 5 mutations of Nsp14, E, and M of BA.1 variant significantly lowered brain viral load and reduced lethality. These results provide new insights into how SARS-CoV-2 Omicron BA.1 is attenuated.

Catalytic Reductive Amination and Tandem Amination-Alkylation of Esters Enabled by a Cationic Iridium Complex.

Reported herein is a convenient and efficient method for one-pot, catalytic reductive amination, as well as the first multi-component tandem reductive amination - functionalization of bench-stable and readily available common carboxylic esters. This method is based on the cationic [Ir(COD)2]BArF-catalyzed chemoselective hydrosilylation of esters, followed by one-pot acid-mediated amination and nucleophilic addition. The reaction was conducted under mild conditions at a very low catalyst loading (0.1 mol% of Ir), which could be further reduced to 0.001 mol%, as demonstrated by a reaction at a 15 g scale. The method is highly versatile, allowing the use of esters with or without α-protons for the N-mono-alkylation of primary and secondary amines to produce diverse secondary and tertiary amines, as well as α-branched/functionalized amines. The method is highly chemoselective and tolerates a variety of functional groups such as bromo, trifluoromethyl, ester, and cyano groups. The value of the method was demonstrated by the one-step catalytic synthesis of two bio-relevant N-mono-methyl α-amino esters and the antiparkinsonian agent piribedil, as well as by the use oftwo shorter chain triglycerides as alkylating feedstock.

Targeted syndromic next-generation sequencing panel for simultaneous detection of pathogens associated with bovine reproductive failure.

Bovine reproductive failure, which includes infertility, abortion, and stillbirth in cattle, leads to significant economic losses for beef and milk producers. Diagnosing the infectious causes of bovine reproductive failure is challenging as there are multiple pathogens associated with it. The traditional stepwise approach to diagnostic testing is time-consuming and can cause significant delays. In this study, we have developed a syndromic next-generation sequencing panel (BovReproSeq) for the simultaneous detection of 17 pathogens (bacteria, virus, and protozoa) associated with bovine reproductive failure. This targeted approach involves amplifying multiple pathogen-specific targets using ultra-multiplex PCR, followed by sequencing with the Oxford Nanopore platform and subsequent analysis of the data using a custom bioinformatic pipeline to determine the presence or absence of pathogens. We tested 116 clinical samples and found that BovReproSeq results matched with current diagnostic methods for 93% of the samples, and most of the disagreements occurring in samples with very low pathogen loads (Ct >35). At the optimal read-count threshold of 10 reads (minimum number of reads to classify the sample as positive), the clinical sensitivity of the assay was approximately 82%, while clinical specificity was 100%. The overall accuracy of the assay was 98.8%. Matthews correlation coefficient (correlation coefficient of binary classification) was approximately 0.90 and F1 score (harmonic mean of precision and recall) was 0.90, indicating excellent overall performance. Our study presents a significant advancement in detecting the infectious agents associated with bovine reproductive failure and the BovReproSeq panel's ability to detect 17 pathogens makes it a promising tool for veterinary diagnostics.IMPORTANCEBovine reproductive failure causes substantial economic losses to beef and milk producers, and infectious disease contributes significantly to this syndrome. Etiologic diagnosis is complicated since multiple pathogens can be involved and infections with some pathogens are asymptomatic or cause similar clinical signs. A stepwise approach to diagnostic testing is time-consuming and increases the risk of missing the correct diagnosis. BovReproSeq is a next-generation sequencing-based diagnostic panel that allows detection of 17 reproductive failure pathogens simultaneously.

Can remotely-sensed vegetation health indices increase the hedging-effectiveness of index insurance? – Insights from Germany

PurposeSatellite-retrieved vegetation health (VH) indices are under active consideration to be integrated into weather index insurance to reduce the basis risk and increase the attractiveness to farmers. The objective of this study is to obtain a deeper understanding of the hedging effectiveness (HE) of the satellite-retrieved VH indices.Design/methodology/approachBy using winter wheat yield records from 79 farms in Northern and Eastern Germany over 20 years, we designed index insurance based on three satellite indices to explore their HE: the Vegetation Condition Index (VCI), the Temperature Condition Index (TCI) and the Vegetation Health Index (VHI) with a spatial resolution of 1 × 1 km. As the benchmark, a meteorological index related to precipitation is employed.FindingsThe results indicate that, on average, the TCI and VHI outperform the benchmark index in a statistically significant way. However, considerable differences across regions are observed. In particular, the highest HE, and therefore basis risk reduction, was found for regions with sandy soils in Eastern Germany.Practical implicationsInsurers can be advised to accelerate the research and development of satellite-based index insurance in Eastern Germany. By considering our insurance design, products with low transaction costs and therefore comparatively low loading factors can be offered to farmers.Originality/valueTo the best of our knowledge, this is the first study that uses a large sample to explore the HE of index insurance based on satellite-retrieved VH indices by focusing on different regions in a country.

Propane dehydrogenation over silicalite‐1 supported PtMn catalyst with low Pt loading

Pt‐based catalysts have been widely studied for propane dehydrogenation (PDH) because of their high activity and environmental sustainability. However, as a precious metal, the development of catalysts with high stability and low Pt content is of great significance. In this study, a series of silicalite‐1‐supported PtMn (0.1PtxMn/S‐1) catalysts with low Pt loading amount (0.1 wt%) was prepared. The effects of different Mn loadings on the physicochemical properties and catalytic performance in the PDH reaction were studied. The addition of an appropriate amount of Mn regulated the dispersion of Pt particles and increased the number of active sites of the catalyst, enhancing the catalytic performance of PDH even at a low Pt loading. The initial propane conversion was 46.1% over 0.1Pt0.3Mn/S‐1 catalyst, and the deactivation rate constant was the lowest of 0.010 h‐1. This may be because an appropriate Mn loading was beneficial for enhancing the interaction between the metal and the support, forming MnOx attached to the S‐1 surface, while the surface of MnOx stabilized the PtMn alloy, thereby improving the catalytic performance for PDH.