Short Space Research Articles

No paleoclimatic anomalies are associated with the late Eocene extraterrestrial impact events

Two distinct extraterrestrial impacts events struck the Earth less than 25,000 years apart in the late Eocene, approximately 35.65 million years ago. These resulted in the Popigai (northern Siberia) and Chesapeake Bay (eastern North America) impacts structures, the largest of the Cenozoic era. To examine the paleoclimatic consequences attributed to the late Eocene Chesapeake and Popigai extraterrestrial impact events, we present multispecies planktonic and benthic foraminiferal oxygen (δ18O) and carbon (δ13C) isotope records. Here we generate data from the Gulf of Mexico, Deep Sea Drilling Project Site 94 covering 35.85 to 35.49 million years ago. No isotopic anomalies or excursions were recorded across the impact horizons. However, ~100,000 years before the impacts, a negative 0.75‰ δ18O shift occurs in planktonic foraminifera, coincident with a 0.25‰ positive change in benthic foraminifera. We interpret this as a warming of ~2 °C in the surface ocean, accompanied by 1 °C deep water cooling, but these modifications are before and not coeval with the impact horizons. Despite the close succession of two or more large extraterrestrial impact events within a short space of time (less than 25,000 years), our study from the Gulf of Mexico indicates no detectable paleoclimatic response.

Boosting Carrier Transport in Quasi-2D/3D Perovskite Heterojunction for High-Performance Perovskite/Organic Tandems.

Wide-bandgap (WBG) perovskites are continuously in the limelight owing to their applicability in tandem solar cells. The main bottlenecks of WBG perovskites are interfacial non-radiative recombination and carrier transport loss caused by interfacial defects and large energy-level offsets, which induce additional energy losses when WBG perovskites are stacked with organic solar cells in series because of unbalanced carrier recombination in interconnecting layer (ICL). To solve these issues, 1,3-propanediammonium iodide (PDADI) is incorporated to form Dion-Jacobson -phase quasi-2D perovskites with mixed high-n-values in WBG perovskites. PDADI simultaneously repairs the shallow/deep defects and establishes a Type-II energy-level alignment between quasi-2D/3D and 3D perovskites for rapid carrier extraction. More importantly, the short-chain diammonium cation in quasi-2D perovskite with high n-values results in a short Pb-I inorganic layer spacing, which enhances the interlayer electronic coupling and weakens the quantum-well confinement effect that restricts carrier transport. The suppressed transport loss increases the electron concentration in the ICL for balanced carrier recombination. The 0.0628 and 1.004 cm2 perovskite/organic tandems achieve remarkable efficiencies of 25.92% and 24.63%, respectively. The quasi-2D capping layer can inhibit ion migration, allowing perovskite/organic tandems to show excellent operational stability (T85 >1000h).

Impact of acid surface pretreatment on the hydrophobic agglomeration of micro-fine ilmenite and titanaugite in flotation

Acid surface pretreatment was employed to realize the selective hydrophobic agglomeration of micro-fine ilmenite in flotation. Microflotation and artificially mixed mineral experiments manifested that after acid surface pretreatment, the recovery of micro-fine ilmenite with the increase of NaOL concentration and the floatability difference of micro-fine ilmenite and titanaugite increased significantly. Zeta potential and contact angle analyses suggested that acid surface pretreatment intensified the adsorption of NaOL on ilmenite surfaces while reducing it on titanaugite surfaces. Turbidity, optical microscope, and EDLVO theory analyses attested that the hydrophobic attraction dominated in a short particle spacing in NaOL solution. Following acid surface pretreatment, the hydrophobic agglomeration between micro-fine ilmenite particles enhanced in NaOL solution due to increased hydrophobic attraction. In contrast, the hydrophobic attraction and agglomeration between micro-fine titanaugite particles as well as between micro-fine ilmenite and titanaugite particles weakened. Overall, acid surface pretreatment improved the selective adsorption of NaOL and the selective hydrophobic agglomeration of micro-fine ilmenite, resulting in enhanced separation efficiency and recovery of micro-fine ilmenite.

Effect of prefatigue-induced persistent slip bands on the strength-ductility match in -oriented Cu single crystals

To explore the effect of persistent slip bands (PSBs) formed during cyclic loading on the static mechanical behavior of materials, [1‾12]-oriented Cu single crystals are selected as target materials, and the tensile behavior of Cu single crystals prefatigued to the stress saturation stage at different plastic shear strain amplitudes (γpl) and the corresponding microstructures, surface deformation features and fracture morphologies are systematically studied. The results show that the formation of few soft PSB ladder-like structures in hard dislocation veins during prefatigue deformation at γpl = 3.7 × 10−4 below the plateau region of cyclic stress-strain (CSS) curve can promote a synchronous improvement of strength and ductility (SISD) compared with the unfatigued crystal. As γpl increases to a lower value of 9.0 × 10−4 within the plateau region, the strength and ductility reduce sharply compared with the case at γpl = 3.7 × 10−4 due to more concentrated plastic deformation caused by a high volume fraction of prefatigue-induced PSBs. With continuously increasing γpl to a higher value of 2.3 × 10−3 within the plateau region, non-uniform dislocation distribution in labyrinth structures and the short spacing between labyrinth walls as well as the fine dislocation cells formed during tension jointly give rise to a slight increase in strength and ductility compared with the crystal prefatigued at γpl = 9.0 × 10−4. As γpl is increased to the level beyond the plateau region, the ductility and ultimate tensile strength continuously increase, resulting from the co-existence of wider deformation bands and dense dislocation walls.

Review of Oriental species of the genus Atopotrophos (Hymenoptera: Ichneumonidae)

A new species of tryphonine Darwin Wasps in the genus Atopotrophos Cushman, 1919, (A. bubeng sp. nov.). is described from Bubeng, Mueang La, Xishuangbanna, Yunnan Province. The new species can be distinguished from all other Atopotrophos species by having 35 flagellomeres, a very short malar space, both scutellum and postscutellum with apical teeth, and from the most similar species, A. spiniger, by its larger size, longer area superomedia, longer T1, and shorter ovipositor. Re-descriptions, illustrations of holotype specimens of A. chinensis and A. spiniger are provided. The type localities of these species are defined, and approximate coordinates and habitat description are added. A key for Oriental species is provided.

Solar-Hydrogen system of additional power supply and digital control system for on-board power supply system

Even for short space flights, such as manned flights to the Moon back in the 60s, it became extremely obvious that electric batteries are completely unsuitable because of their huge mass needed to store the required supply of onboard energy. Therefore, already in the 60s of the last century, the USA and the USSR took the path of using a hydrogen storage system using hydrogen fuel cells.Solar-hydrogen energy systems for spacecraft reliably provide energy for carrying out various kinds of unscheduled work on board and for eliminating emergency situations. Surplus energy is constantly accumulated on board in the form of the chemical energy of cryogenic hydrogen. The article presents too the result of the development of a solar-hydrogen power supply system for spacecraft, the onboard network of which provides slow and fast processes. This paper delves into designing digital control systems for power conditioning devices on the example of charging-discharging device based on a boost DC-DC converter. The device was implemented to condition a storage battery by properly charging and discharging it. A technique for constructing a small signal model of the converter has been developed. This involves constructing a block diagram using the discontinuous switching functions and analog models of electrical circuit components. The transfer functions of the analog controllers for the two-loop subordinate control system were derived. Then the procedure of a bilinear z-transform to the given transfer functions was applied. As a result, the discrete transfer functions of the digital controllers were obtained. Realization both analog and digital controllers in Matlab Simulink confirmed their identical behavior and stability within the power converter. Experimental studies of the static and dynamic waveforms of the digital control system showed controllability and stability of the charging-discharging device for the storage battery in typical operating modes. Thus, the method of synthesizing digital control systems for energy converters is proved valid and applicable for designing new power conditioning devices within modern power supplies.

Contact with nature may be a remedy for loneliness: A nationally representative longitudinal cohort study

BackgroundNature prescribing – a written recommendation by a health professional for a person to spend more time in nature for health reasons – is being heralded by some as a potential solution to loneliness, defined as a felt deprivation of meaningful connection, companionship, and camaraderie. However, such recommendations currently lack evidence on how much time in natural environments is needed to tackle loneliness and over what timescale. MethodsGeneral, emotional, and social loneliness were measured using De Jong Gierveld's 6-item scale in a nationally representative sample of 3043 Australian participants at baseline (October 2020), with 2421 and 2123 completing follow-ups at 4 months (February 2021) and 16 months (February 2022), respectively. Multilevel logistic regressions examined the odds of change in loneliness status between baseline and follow-up in relation to hours spent in nature in the 7 days prior to the baseline survey, adjusting for confounding factors that influence time spent in nature and the risk of feeling lonely. FindingsRelief from general loneliness in those experiencing it at baseline was 22.4% at month 4 and 29.4% at month 16. The equivalent findings for relief from social loneliness and emotional loneliness were 21.2% and 24.6%, and 34.2% and 41.2% at months 4 and 16, respectively. Incidence of loneliness at 4 months was 21.8% (general), 26.1% (social), and 11.8% (emotional), and at 16 months was 22.7% (general), 25.6% (social), and 12% (emotional). At each time point, the prevalence of loneliness was lower among participants with more time in nature. Just 1–2 h per week in nature (versus <1) was associated with relief from social loneliness at 4 months (Odds Ratio [OR] 1.69, 95%CI 1.10, 2.65) and at 16 months (OR 2.10, 95%CI 1.34, 3.30). Higher odds of relief from emotional loneliness were observed at 3–4 h spent in nature at 4 months (OR 1.84, 95%CI 1.11, 3.06) and at 16 months (OR 1.82, 95%CI 1.09, 3.07). Incidence of loneliness was not associated with nature contact. InterpretationIncreasing time in nature may an effective non-medical prescription for people who are lonely to find durable relief within a relatively short space of time. Findings from this longitudinal study can inform further investigation through randomised trials of co-designed nature prescriptions targeting relief from loneliness in vulnerable populations.

Are AI detection and plagiarism similarity scores worthwhile in the age of ChatGPT and other Generative AI?

Recent advancements in chatbots have provided students and academics with a new mode of how knowledge can be sourced and composed. Within a very short space of time, students and academics have flocked to use ChatGPT and other Generative Artificial Intelligence (GAI) platforms owing to their capable responses. Additionally, apart from the generative chatbots (such as ChatGPT and Gemini), AI writing tools for paraphrasing, summarising, and co-writing have also become capable and increasingly prevalent to such a degree that the public is spoilt for choice. Having conducted tests on popular chatbots and AI writing tools, it became clear that while programs like Turnitin are developing new algorithms to detect plagiarism and AI-generated content, the initial findings from this study suggest that this may be an increasingly difficult task. These tests were published on YouTube, and within a few weeks, the evidence garnered tens of thousands of views as students and educators seemed uncertain about the strengths, weaknesses, and legalities of these AI tools. What is clear is that we have passed the tipping point, and AI assistance is no longer just a grammar fixer. The implications of this are concerning and far-reaching, as plagiarism is already a significant problem in universities. This position paper reports on tests conducted using Turnitin software and AI writing tools such as ChatGPT and QuillBot. These real-world tests support the paper’s position that it is becoming increasingly difficult to determine what constitutes original work in a world of GAI. The aim of this article is to provide evidence that educators who rely on similarity checking and AI detectors in their current form may inadvertently be supporting plagiarism rather than reducing it. A new method of academic plagiarism detection is proposed, utilizing large language models to generate and track ideas, thereby serving as an idea database. The proposed method focuses on the "understanding" of the work rather than on text similarity.

Use of the Perturbing Sphere Method for the Estimation of Radiofrequency Coils' Efficiency in Magnetic Resonance Applications: Experience from an Electromagnetic Laboratory.

Radiofrequency (RF) transmitter and receiver coils are employed in in magnetic resonance (MR) applications to, respectively, excite the nuclei in the object to be imaged and to pick up the signals emitted by the nuclei with a high signal-to-noise ratio (SNR). The ability to obtain high-quality images and spectra in MR strongly depends on the RF coil's efficiency. Local coil efficiency can be estimated with magnetic field mapping methods evaluated at a fixed point in space. Different methods have been described in the literature, divided into electromagnetic bench tests and MR techniques. In this paper, we review our experience in designing and testing RF coils for MR in our electromagnetic laboratory with the use of the perturbing sphere method, which permits coil efficiency and magnetic field mapping to be estimated with great accuracy and in a short space of time, which is useful for periodic coil quality control checks. The method's accuracy has been verified with simulations and workbench tests performed on RF coils with different surfaces and of different volumes. Furthermore, all the precautions taken to improve the measurement sensitivity are also included in this review, in addition to the various applications of the method that have been described over the last twenty years of research in our electromagnetic laboratory.

Facile strategy for the synthesis of antimicrobial poly(vinyl chloride) functionalized with benzimidazole

AbstractSynthesizing antimicrobial materials is a viable approach to combating microbes and mitigating their detrimental consequences on public health and economic domains. Here, we aim to design and synthesize hybrid polymers composed of poly(vinyl chloride) (PVC) and benzimidazole derivatives, in addition to evaluating their antimicrobial efficacy. PVC was chemically functionalized affording 4 conjugates where the benzimidazole motif was incorporated indirectly into the PVC through a triazole ring combined with a short linker. This functionalized PVC was synthesized by employing Cu azide–alkyne cycloaddition (CuAAC) conditions (click chemistry). The second functionalized PVC was synthesized by a nucleophilic substitution reaction to give 5, which has a benzimidazole moiety attached directly to the PVC via a short spacer arm. The benzimidazole derivatives and the corresponding benzimidazole‐PVC conjugates were investigated by elemental analysis and spectroscopic techniques (IR, NMR, and MS) as needed, besides UV–vis spectroscopy, x‐ray diffraction (XRD), and scanning electron microscopy (SEM) and energy dispersive x‐ray spectroscopy (EDX) in the case of the polymeric conjugates. The SEM morphology demonstrated a change in the PVC surface after the modification, showing spongy structures. Furthermore, the chemical characterization using EDX revealed peaks representing C, O, and N, in addition to the characteristic Cl peaks. The benzimidazole derivatives and the corresponding functionalized PVC were evaluated as antimicrobial agents against a variety of Gram‐negative and Gram‐positive bacteria and fungi strains utilizing the well diffusion assay. The data revealed an improvement in the antimicrobial activity of the functionalized PVC (4) that contained triazolobenzimidazole against pathogenic Escherichia coli and S. typhimurium.Highlights Microbes have negative impact on public health and economic domains Synthesizing antimicrobial materials is a viable approach to combating microbes We herein synthesized PVC/benzimidazole hybrid polymers Functionalized PVC was synthesized and characterized by IR, NMR, SEM and EDX PVC/benzimidazole hybrids were evaluated as antimicrobial agents.

High-Yield Exfoliation of Stanene Nanodots for High-Performance Organic Light-Emitting Diodes.

Stanene nanodots (SnNDs) derived from layered tin have attracted considerable interest due to their conveniently tunable bandgap and topological superconductivity. However, high-yield exfoliation of ultrathin SnNDs is still a challenge due to the short layer spacing and strong binding energy. In this work, atomically thin SnNDs with a uniform size of 2.3 nm are successfully prepared by utilizing imidazolium ionic liquid-assisted exfoliation. The obtained SnNDs possess a wide bandgap of 2.69 eV, along with notable solvent compatibility (well dispersed in both polar and nonpolar solvents) and excellent stability. Furthermore, we construct Ir(ppy)3-based green OLED with hybridizing SnNDs and graphene oxide (GO) as the hole injection layer (HIL). It proves that the application of SnNDs helps to modulate the work function and passivate surface defects of GO, increasing hole mobility and thereby improving the device performance. Compared to the PEDOT:PSS-based control device, the optimized SnNDs-GO-based OLED demonstrates an improvement of 6.56, 41.06, and 8.16% in current efficiency (CE), power efficiency (PE), and external quantum efficiency (EQE), respectively. This work not only introduces a new approach to preparing 2D SnNDs but also creates a novel HIL material for OLED devices.

Formation of Layered Liquid Crystal by Cooperation of Sidechain Array and Rigid Polyacetylene Mainchain

ABSTRACT An acetylene derivative monomer with a pyrimidine – type sidechain with three rings was synthesized by Steglich esterification. Polymerization of the acetylene derivative was then carried out with a rhodium complex. The acetylene monomer and mono-substituted polyacetylene derivative showed liquid crystals (LCs) because their tricyclic parts worked as a mesogenic core. The monomer as an acetylene derivative showed smectic with a tilted structure in the LC aggregation form. The mono-substituted polyacetylene bearing mesogen via short alkyl spacer showed lyotropic and thermotropic LCs of the smectic phase, although generally flexible long alkyl spacer from the main chain connected to sidechain mesogen is required for exhibiting liquid crystal in sidechain type polymer liquid crystals. In the present study, rigid mainchain aligns the sidechain mesogen array to form non-tilted LC. Properties of LCs were evaluated by various analytical techniques, including polarizing optical microscopy. Structural properties were evaluated by nuclear magnetic resonance spectroscopy, gel permeation chromatography, infrared spectroscopy, and ultraviolet – visible absorption spectroscopy.

Climate action to enable quality education: exploring the potential of Eco-Schools to reverse the triple education crises in Rwanda

This article presents the results of research conducted between 2021 and 2023 by the Albertine Rift Conservation Society (ARCOS) with 240 partners including teachers, learners and parents in six Rwandan schools. A relational knowledge co-creation methodology was used to gain a shared understanding of education and climate change challenges in the schools and co-create solutions using the Eco-Schools problem-based learning pedagogy. The knowledge co-creation processes revealed a negative relationship at the intersection between climate change and quality education which is interrupting successful implementation of both the Competence-Based Curriculum (CBC), and the School Feeding Programme policies of the Government of Rwanda, affecting national progress towards SDG 4 and SDG 13. However, by integrating climate action projects in the CBC, with practical skills and knowledge from parents and wider community members, education barriers caused by poor school conditions, and poor nutrition, health and comfort of learners are being removed, while the quality and relevance of teaching and learning in schools is being improved. The article therefore proposes the Eco-Schools programme as a potential means of simultaneously addressing the UN’s ‘triple crisis’ of inclusion, quality and relevance. Ultimately, by showing that it is possible to transform education in even the most challenged schools, at a relatively low cost, within a very short space of time (one school year) and without large-scale curriculum reform or infrastructure, the findings of this research promote wider, faster and more optimistic progression toward the UNESCO’s ‘Reimagining Education’ vision and the Greening Education Partnership targets.

Phase Behaviors and Photoresponsive Thin Films of Syndiotactic Side-Chain Liquid Crystalline Polymers with High Densely Substituted Azobenzene Mesogens.

Azobenzene-containing polymers (azopolymers) are a kind of fascinating stimuli-responsive materials with broad and versatile applications. In this work, a series of syndiotactic C1 type azopolymers of Pm-Azo-Cn with side-chain azobenzene mesogens of varied length alkoxy tails (n=1, 4, 8, 10) and different length alkyl spacers (m=6, 10) have been prepared via Rh-catalyzed carbene polymerization. The thermal properties and ordered assembly structures of thus synthesized side chain liquid crystalline polymers (SCLCPs) have been systematically investigated with differential scanning calorimetry (DSC), polarized optical microscopy (POM) and variable-temperature small/wide-angle X-ray scattering (SAXS/WAXS) analyses. P10-Azo-C1 and P10-Azo-C4 with shorter alkoxy tails exhibited hierarchical structures SmB/Colob and transformed into SmA/Colob at a higher temperature, while P10-Azo-C8 and P10-Azo-C10 with longer alkoxy tails only displayed side group dominated layered SmB phase and transformed into SmA phase at higher temperatures. For P6-Azo-C4 with a shorter spacer only showed a less ordered SmA phase owing to interference by partly coupling between the side chain azobenzene mesogens and the helical backbone. More importantly, the series high densely substituted syndiotactic C1 azopolymer thin films, exhibited evidently and smoothly reversible photoresponsive properties, which demonstrated promising photoresponsive device applications.

Effect of Kerosene Dual-Jet Spacing on the Mixing and Combustion Characteristics of a Scramjet Combustor.

As the core of a hypersonic propulsion system, the effective mixing efficiency of fuel and air in a supersonic combustor is crucial for its performance. This study focuses on a cold supersonic flow and employs computational fluid dynamics (CFD) techniques combined with Euler-Lagrange method's discrete-phase model (DPM) for multiphase flows, K-H and R-T (Kelvin-Helmholtz and Rayleigh-Taylor) mixing and atomization models, turbulence models, and surface evaporation models to investigate the injection, atomization, and mixing characteristics of kerosene in supersonic airflow. In order to enhance the mixing efficiency between kerosene and air while reducing flow losses, this study examines a staggered dual-jet injection scheme, with the dual jets arranged at the center of the cavity and having a dual-jet spacing of 10 and 20 mm, respectively. Starting from the interaction mechanism between jets, the impact of different staggered dual-jet spacings on the kerosene jet penetration height, span expansion area, angle of the shock wave, and Sauter mean diameter distribution was analyzed. The results show that a short dual-jet spacing (10 mm) leads to greater penetration height, wider span expansion, and a larger angle of the shock wave. When the dual-jet spacing is shorter, the interaction between the fuel jet and the cavity shear layer is stronger, resulting in an improved fuel mixing efficiency. The achievements of this study are consistent with previous experimental measurements and the literature, demonstrating a strong theoretical foundation for optimizing the design of hypersonic engines by deepening the understanding of the fundamental atomization mechanisms of kerosene jets in cold-state supersonic flows. Moreover, these results hold practical significance in improving the efficiency of kerosene combustion and enhancing the performance of flame stabilization devices.

Agronomic performance of cowpea cultivars in first crop in Southwest of Minas Gerais, Brazil

The cowpea (Vigna unguiculata (L.) Walp.) is well adapted to high temperatures, water deficits and low fertility soils, being widely cultivated in regions less favorable to common beans. Its grains are rich in proteins, vitamins and minerals, representing an important food source and a promising alternative for producing protein at low cost, in a short space of time, given the precocity of its cycle. However, in the state of Minas Gerais there is only a recommendation for one cowpea cultivar, the Poços de Caldas cultivar. In addition to being quite old, it is no longer found in crop production fields. The aims of study was to evaluate the agronomic performance of cowpea cultivars and to recommend cultivars adapted to cultivation in edaphoclimatic conditions of Southwest Region of Minas Gerais State, Brazil. The experiments were carried out in Passos city, Minas Gerais State, Brazil, during the first crop period, in 2021/2022 and 2022/2023 years, with 10 commercial cowpea cultivars, in a randomized block experimental design, with five replications. The mass of a thousand seeds and the grain index correlated directly with the yield. Cultivars with the lowest grain yields promoted the highest pod lengths and number of grains per pod. The best morphophysiological results for cowpea were obtained in 2021/2022 year. The most adapted cowpea cultivars for period of first crop in edaphoclimatic conditions of Southwest Region of Minas Gerais State, Brazil, were BRS Novaera, BRS Guariba, and BRS Xique-Xique and least indicated was BRS Marataoã. More studies are needed to consolidate cowpea cultivation in the Southwest Region of Minas Gerais, mainly in second-crop crops.

Synchronised WindScanner field measurements of the induction zone between two closely spaced wind turbines

Abstract. Field measurements of the flow interaction between the near wake of an upstream wind turbine and the induction zone of a downstream turbine are scarce. Measuring and characterising these flow features in wind farms under various operational states can be used to evaluate numerical flow models and design of control systems. In this paper, we present induction zone measurements of a utility-scale 3.5 MW turbine with a rotor diameter of 126 m in a two-turbine wind farm operating under waked and unwaked conditions. The measurements were acquired by two synchronised continuous-wave WindScanner lidars that could resolve longitudinal and lateral velocities by dual-Doppler reconstruction. An error analysis was performed to quantify the uncertainty in measuring complex flow situations with two WindScanners. This is done by performing a large-eddy simulation while using the same measurement layout, modelling the WindScanner sensing characteristics and simulating similar inflow conditions observed in the field. The flow evolution in the induction zone of the downstream turbine was characterised by performing horizontal-plane dual-Doppler scans at hub height. The measurements were conducted for undisturbed, fully waked and partially waked flows. Evaluation of the engineering models of the undisturbed induction zone showed good agreement along the rotor axis. In the full-wake case, the measurements indicated a deceleration of the upstream turbine wake due to the downstream turbine induction zone as a result of the very short turbine spacing. During a wake steering experiment, the interaction between the laterally deflected wake of the upstream turbine and the induction zone of the downstream turbine could be measured for the first time in the field. Additionally, the analyses highlight the affiliated challenges while conducting field measurements with synchronised lidars.

Spatial variation of short birth intervals and their determinant factors among reproductive women in Ethiopia using a geographically weighted regression model.

In low- and middle-income nations, a significant proportion of maternal and infant deaths are caused by a short birth interval (SBI). In Ethiopia, it is the main factor contributing to maternal and infant mortality. Understanding the spatial distribution of SBIs, i.e., birth intervals of less than 33 months, and the factors that influence them is important for categorizing and promoting targeted interventions. This study used a geographically weighted regression model to evaluate the factors associated with SBIs in hot areas of Ethiopia. The 2019 Ethiopian Mini Demographic and Health Survey, which is nationally representative, provided the data for this study. The first step in the two-stage cluster design used to collect the data was enumeration areas, and the second stage was households. The survey was conducted between 21 March 2019 and 28 June 2019. A hot spot analysis (local Getis-Ord Gi* statistics) was initially used to investigate spatial variation in SBIs. Geographically weighted regression was used to examine the regional variation in the relationship between SBIs and the factors that cause them. The study indicated that the overall proportion of SBIs among women in Ethiopia was 43.2%. The values for Global Moran's I (Moran's I = 0.773 and p < 0.001) showed the presence of significant SBIs clustering in Ethiopian administrative zones in Ethiopia. High-risk areas of the SBIs include Jarar, Doolo, Shabelle, Afder, Liben, Korahe, Nogob, West Harerge, Guji, Sidama, and Assosa zones. Living in a geographic region with a high proportion of uneducated women, women lacking breastfeeding practices, and followers of Orthodox religions increased the proportion of SBIs. Our full map of hot spots for short birth spacing and the factors that affect them helps in the implementation of precise public health measures for decision-makers.

Monitoring and assessing the effectiveness of the biological control implemented to address the invasion of water hyacinth (Eichhornia crassipes) in Hartbeespoort Dam, South Africa

Water hyacinth is one of the most aggressive alien invasive plants, which invades freshwater resources and destroys native biodiversity. The plant proliferates rapidly over a short space of time, forming thick dense layer on the surface of freshwater bodies. Monitoring and management of water hyacinth is essential to protect water resources affected by the presence of this plant. The study assessed the effectiveness of biological agent (Megamelus scutellaris) applied in the Hartbeespoort Dam from pre (2016–2017) and post (2018–2023) biological control to manage water hyacinth spread and proliferation. In achieving this main goal, the study used advanced cloud-computing machine learning techniques and multi date Sentinel-2 Multispectral Instrument (MSI) data to monitor the effectiveness of such biological control. During this analysis, remote sensing data was acquired for two time periods namely: pre-intervention (2016–2017) and post intervention (2018–2023) to establish variation in the spatio-temporal distribution of water hyacinth in the Hartbeespoort Dam using various machine learning techniques (Support Vector Machine (SVM), Classification and Regression Tree (CART), Random Forest (RF) and Naïve Bayes (NB)) in Google Earth Engine cloud computing platform, and assessed the spectral separability of water hyacinth from numerous land cover types, within and around the Hartbeespoort Dam using the Sentinel-2 derived spectral reflectance curves. The results indicated that the extent of water hyacinth area coverage decreased from 15% to below 6% between the period of 2018 and 2021, however, a significant increase was noted between November 2022 and April 2023, after the biological control was introduced. The significant increase observed during the time period of November 2022 and April 2023 can be attributed to nutrient rich water discharging into the dam from the Crocodile River during the time of flooding reported in November 2022. The result further indicate that RF produced the highest overall accuracies ranging between 93.42% and 98.70%. While NB produced the lowest accuracies ranging between 87.76% and 92.08%. These findings underscore the relevance of new generation satellite dataset and machine learning algorithms in monitoring the effectiveness of the biological controls of alien invasive spread provide information regarding alien plant invasion. Therefore, aligning with Sustainable Development Goals (SDG 6) emphasizing on the importance of implementing effective control measures to control invasive species and their impact on water resources thus ensuring the sustainability of freshwater ecosystems and the availability of clean water resources.

Analytical Model to Deduce the Conformational and Dynamical Behavior in Dendrimers: A Review.

This review utilizes an optimized Rouse-Zimm discrete hydrodynamic model and the preaveraged Oseen tensor, which accurately consider hydrodynamic interactions to study model dendrimers. We report the analytical theories that have been previously developed for the creation of generalized analytical models for dendrimers. These generalized theories were used to assess the conformational and dynamical behavior of the dendrimers. By including stiffness in the bonds, the neglect of excluded volume interactions may be somewhat offset. This is true at least in the case of short spacers. While the topological limitations on the directions and orientations of the individual bond vectors in dendrimers implement semiflexibility, the intensity of these contacts was determined by the potential geometric orientations of the bonds, and later on the excluded volume interactions in dendrimers, which were described in terms of the effective co-volume between nearest non-bonded monomers and modeled using the delta function pseudopotential. With the aid of the models developed, the authors condensed various conformational and dynamic properties of dendrimers that depend on their degree of semiflexibility and the strength of the excluded volume. These analyses came to the conclusion that the flexible dendrimer in one limit and the earlier described freely rotating model of dendrimers in the other constitute a highly generalized way of capturing a wide range of conformations in the developed mathematical model in dendrimers.