Earlier Studies Research Articles

The Oxidation of Electron-Rich Arenes Using a H2O2-Proline System.

This study introduces a novel proline-catalyzed oxidation system employing hydrogen peroxide to synthesize quinones from a diverse range of substrates, including hydroquinones, phenols, resorcinols, aldehydes, and polycyclic aromatics. This approach is well-aligned with green chemistry principles, offering a more environmentally benign approach than earlier studies. Notably, this approach uses cost-effective reagents, proline as a readily available organocatalyst, reduced equivalents of H2O2, metal-free conditions, and notably short reaction times to achieve moderate-to-high yields. This promising approach encourages further exploration of the H2O2-proline system in oxidation reactions. This study's innovative approach and good results set a strong foundation for future research to expand the scope and efficiency of green oxidation processes.

Comparative dosimetric analysis of normal brain tissue in patients with Nasopharyngeal carcinoma at different stages after radiation therapy

IntroductionRadiotherapy (RT) is the main treatment for patients with nasopharyngeal carcinoma (NPC). NPC patients at different stages have varying levels of damage to normal brain tissue after RT. No study has yet thoroughly analyzed the variations in radiation dosages in the brain for different stages of NPC patients treated with RT. This study aims to examine these variations. Methods1446 NPC patients’ CT and RTdose data were retrospectively reviewed. Analysis of the radiation dosage was executed on these 803 patients. The RTdose images for several patient groups were averaged after registering each patient’s RTdose data to the CT brain template created in our earlier study. The voxel-based (VB) analysis was used to examine the dose variations in the brains of three groups of NPC patients: the early-stage group, the stage III group, and the stage IV group. ResultsAs the disease progresses from early to advanced stages, the intensity and volume of radiation in the brain increase. The normal brain tissue accepted a substantially larger dosage in more advanced NPC patients. Differences in brain regions between stage III and early-stage patients were minimal compared to any other two groups. Brain regions exhibited substantial variations between the stage IV group and all other patient groups were broadly distributed. ConclusionOur findings highlight the critical role of NPC staging in the therapeutic strategy, emphasizing the heterogeneity of radiation-induced tissue damage across disease stages and implying the need to develop stage-specific RT plans.

Investigating the Discoloration of Leaves of Dioscorea polystachya Using Developed Atomic Absorption Spectrometry Methods for Manganese and Molybdenum.

The Chinese yam (Dioscorea polystachya, DP) is promising for the food and pharmaceutical industries due to its nutritional value and pharmaceutical potential. Its proper cultivation is therefore of interest. An insufficient supply of minerals necessary for plant growth can be manifested by discoloration of the leaves. In our earlier study, magnesium deficiency was excluded as a cause. As a follow-up, this work focused on manganese and molybdenum. To quantify both minerals in leaf extracts of DP, analytical methods based on atomic absorption spectrometry (AAS) using the graphite furnace sub-technique were devised. The development revealed that the quantification of manganese works best without using any of the investigated modifiers. The optimized pyrolysis and atomization temperatures were 1300 °C and 1800 °C, respectively. For the analysis of molybdenum, calcium proved to be advantageous as a modifier. The optimum temperatures were 1900 °C and 2800 °C, respectively. Both methods showed satisfactory linearity for analysis. Thus, they were applied to quantify extracts from normal and discolored leaves of DP concerning the two minerals. It was found that discolored leaves had higher manganese levels and a lower molybdenum content. With these results, a potential explanation for the discoloration could be found.

Employment and work intentions of refugee women. Evidence on Syrians in the Netherlands

ABSTRACT This study examines the employment and work intentions of Syrian refugee women in the Netherlands. While earlier studies showed that refugee women have dramatically low labor force participation rates, it remains poorly understood why this is the case. In this study, we provide new insights, using large-scale, nationally representative data on Syrian refugee women in the Netherlands. Our analyses provide evidence to suggest that beyond human capital characteristics, three gender-specific factors contribute to lower participation rates: discrimination of Muslim women who wear a veil, family constraints and traditional gender role attitudes. Among Syrian unemployed women, we find that wearing a veil or having young children is associated with an inability to work, whereas traditional gender role attitudes are significantly associated with unwillingness to work.

Assessing the impact of corporate governance principles on the Small and Medium Enterprises (SMEs)’ financial success in Kwa-Zulu Natal (KZN): Application of Stewardship theory

This study investigates how corporate governance (CG) principles affect the financial performance of Small and Medium Enterprises (SMEs) in Kwa-Zulu Natal (KZN), South Africa, using stewardship theory. Corporate governance (CG) encompasses the regulations, procedures, and mechanisms Overseeing the administration and implementation of a business. Efficient corporate governance (CG) is crucial for Small and Medium Enterprises (SMEs) to function with maximum effectiveness and optimise entrepreneurial value. The study seeks to fill this vacuum in information by investigating the impact of using stewardship theory, which prioritises the long-term interests of stakeholders, on the financial performance of small and medium-sized enterprises (SMEs) in KZN.A quantitative approach was employed and a cross-sectional design was employed to survey 217 SMEs in the Durban South area. Descriptive statistics reveal a diversified KZN SME environment, with a predominance of medium-sized businesses, balanced gender representation, and a variety of business ages and educational backgrounds among owners and managers. Inferential statistics show significant correlations between CG principles and financial success metrics of SMEs, particularly affecting returns on invested capital and assets, net profit, asset value, and sales turnover. The results are consistent with earlier studies on the beneficial effects of CG on SME performance. The study is limited to SMEs in the Durban South area and may not be generalizable to other regions. Future research might compare studies across different areas and examine the long-term effects of CG on SMEs to identify optimum practices. The study recommends prioritizing efficient CG procedures tailored to SME needs. It suggests developing business management competencies and advocating for supporting legislation to enhance SME performance.

Supervising Veterinarians as Boundary-Spanning Agents

Boundary-spanning agency is important for weaving together different ways of doing and knowing. This article examines boundary-spanning agency in the context of courtroom contestation of veterinary expertise. Analysing Finnish supreme administrative court judgments, we highlight how knowledge claims about animal welfare and about the process of supervisory inspections are deployed and contested by both veterinarians and animal owners in a bid to set down an authoritative interpretation about empirical actuality at the inspected sites. A central finding is that veterinarians, contrary to the implications of earlier studies, are in a potent position in their supervising role. Given the lack of intermediary soft law mechanisms such as inspection guidelines, the interpretative space left between animal protection law and veterinarians’ inferences about the conditions at the inspected site leaves veterinarians with a wide mandate to make decisions about ending livelihoods and euthanising the inspected animals.

Objective identification of meteorological fronts and climatologies from ERA-Interim and ERA5

Abstract. Meteorological fronts are important due to their associated surface impacts, including extreme precipitation and extreme winds. Objective identification of fronts is therefore of interest in both operational weather prediction and research settings. The aim of this study is to produce a front identification algorithm based on earlier studies that is portable and scalable to different resolution datasets. We have made a number of changes to an earlier objective front identification algorithm, applied these to reanalysis datasets, and present the improvements associated with these changes. First, we show that a change in the order of operations yields smoother fronts with fewer breaks. Next, we propose the selection of the front identification thresholds in terms of climatological quantiles of the threshold fields. This allows for comparison between datasets of differing resolutions. Finally, we include a number of numerical improvements in the implementation of the algorithm and better handling of short fronts, which yield further benefits in the smoothness and number of breaks. This updated version of the algorithm has been made fully portable and scalable to different datasets in order to enable future climatological studies of fronts and their impacts.

In-situ formation of surface “self-protective” graphitic layer on phenolic resin-based thermal protection composites

Phenolic resin (PR) composites are widely utilized as thermal protection materials for high-speed aircraft, where their protection mechanisms have been investigated in earlier studies. However, it remained indistinct about the evolution behavior of the outermost surface and its subsequent effects on the ablation performance. Herein, this work re-investigated the morphological transformation and chemical conversion on the outermost surface of a silica fiber-reinforced PR board after ablation by means of combined experimental characterizations at micro- and nanoscale (SEM, TEM, Raman spectroscopy, XRD, XPS) and computational study (ReaxFF-based molecular dynamic simulation). For the first time, our study revealed that its outermost ablated surface demonstrated a distinct evolution behavior in terms of both the in-situ formation of “self-protective” graphitic layer and the radial redistribution of surface carbonaceous substances with different degrees of graphitization, leading to varied ablation resistance along the radial direction of the PR board. In addition, the computational study investigates the ablation-induced graphitization and its influence on the ablative resistance of PR surface. It indicated that, at equivalent energy flux density, PR with graphitized structures exhibited improved thermal protection performance, which can be attributed to decreased thermal conductivity and increased density, leading to a reduced ablation recession rate. Such revelation provides an alternative route in the design of PR-based ablative materials with enhanced ablation resistance.

Feasibility and Tolerability of Daily Theta Burst Stimulation in Autistic Youth with Intellectual Disabilities and Minimally Speaking Status: A Pilot Double-Blind Randomized Sham-Controlled Trial.

Scarce clinical trials involving autistic people with intellectual disability (ID) and minimally speaking (MS) status have been a substantial unmet research need in the field. Although earlier studies have demonstrated the feasibility and beneficial potentials of repetitive transcranial magnetic stimulation (rTMS) over the dorsolateral prefrontal cortex (DLPFC) in intellectually able autistic people, the feasibility and tolerability of applying rTMS in autistic people with ID/MS has never been studied. We conducted the world-first 4-week randomized, double-blind, sham-controlled pilot trial to investigate the feasibility, tolerability, and safety of intermittent theta burst stimulation (iTBS, a variant of excitatory rTMS) over the left DLPFC in autistic youth with ID/MS. 25 autistic youth with ID/MS (aged 8-30 years) were randomized to a 20-session 4-week daily iTBS (n = 13) vs. sham stimulation (n = 12) with follow-up 4 and 8 weeks, respectively, after the last stimulation. A retention rate was 100% in our study. Adverse events of local pain (38%) and dizziness (8%) were only noted in the active group. All adverse events were mild and transient. There were no seizures, new behavioral problems, or other severe/serious adverse events noted. No participants dropped out due to adverse events. With a small sample size, we did not find any beneficial signal of DLPFC iTBS. Our pilot data suggest regular daily TBS treatment for four weeks is feasible, well tolerated and safe in autistic youth with ID/MS. Future randomized controlled trials with sufficiently powered samples are needed to investigate the beneficial potential of rTMS/TBS for autistic people with ID/MS.

Characterization of the impact of dietary immunostimulant CpG on the expression of mRNA biomarkers involved in the immune responses in Atlantic salmon (Salmo salar)

Infectious diseases have significantly impacted Atlantic salmon aquaculture worldwide. Modulating fish immunity with immunostimulant-containing functional feeds could be an effective strategy in mitigating disease problems. Previously, we characterized the impact of polyriboinosinic polyribocytidylic acid (pIC) and formalin-killed typical Aeromonas salmonicida bacterin on miRNA expression in Atlantic salmon fed a commercial diet with and without immunostimulant CpG. A set of miRNA biomarkers of Atlantic salmon head kidney responding to pIC and/or bacterin immune stimulations was identified (Xue et al., 2019) [1]. Herein, we report a complementary qPCR study that investigated the impact of the pIC, bacterin and dietary CpG on the expression of immune-relevant mRNAs (n = 31) using the same samples as in the previous study (Xue et al., 2019) [1]. Twenty-six of these genes were predicted target transcripts of the pIC- and/or bacterin-responsive miRNAs identified in the earlier study. The current data showed that pIC and/or bacterin stimulations significantly modulated the majority of the qPCR-analyzed genes involved in various immune pathways. Some genes responded to both stimulations (e.g. tnfa, il10rb, ifng, irf9, cxcr3, campb) while others appeared to be stimulation specific [e.g. irf3, irf7a, il1r1, mxa, mapk3 (pIC only); clra (bacterin only)]. A. salmonicida bacterin stimulation produced a strong inflammatory response (e.g. higher expression of il1b, il8a and tnfa), while salmon stimulated with pIC showed robust interferon responses (both type I and II). Furthermore, the current data indicated significant down-regulation of immune-relevant transcripts (e.g. tlr9, irf5, il1r1, hsp90ab1, itgb2) by dietary immunostimulant CpG, especially among pre-injection and PBS-injected fish. Together with our prior miRNA study, the present research provided complementary information on Atlantic salmon anti-viral and anti-bacterial immune responses and on how dietary CpG may modulate these responses.

Alumanyl Reduction, Reductive Coupling and C-H Isomerization of Organic Nitriles.

The behavior of the potassium alumanyl, [{SiNDipp}AlK]2 ({SiNDipp} = {CH2SiMe2N(Dipp)}2; Dipp = 2,6-i-Pr2C6H3), toward organic nitriles has been investigated. In common with earlier studies of the reactivity of charge neutral Al(I) species with multiply bonded small molecules, it is suggested that the initial step in all the reactions involves [2 + 1] cycloaddition and the generation of an [η2-C=N-Al] alumina azacyclopropane unit. In the cases of o- and m-tolyl-substituted aryl nitriles, this species is too kinetically labile to allow its isolation and undergoes C-C coupling via immediate Al-C/C≡N insertion to yield the alumina diazabutadiene derivatives. In contrast, the increased steric profile of alkyl nitriles imposes a marked influence on the nature of the products formed. Consistent with the proposed sequential pathway, reaction of [{SiNDipp}AlK]2 with t-BuCN provides an isolable alumina cyclopropane species that is kinetically resistant to onward reaction with a further nitrile equivalent. While reduction in the alkyl nitrile steric demands by use of i-PrCN again facilitates C-C bond formation, the crowding of the Al center by the resultant alumina-diazabutadienediide moiety appears to be beyond the limit of kinetic viability, resulting in an unusual 2-fold C-H to N-H isomerization from one of the C-iso-propyl substituents and the isolation of a 1-alumina-2,5-diazabutadiene structure.

Identification of a Promising Novel Genetic Source for Rice Root-Knot Nematode Resistance through Markers Associated with Trait-Specific Quantitative Trait Loci.

Direct-seeded rice (DSR) is gaining popularity among farmers due to its environmentally safe and resource-efficient production system. However, managing the rice root-knot nematode (RRKN), Meloidogyne graminicola, remains a major challenge in DSR cultivation. Developing genetic resistance is a pragmatic and effective approach compared to using hazardous pesticides. Pusa Basmati 1121 (PB1121) is the most popular Basmati rice variety, but it is highly susceptible to RRKN. In contrast, Phule Radha (PR) has shown highly resistant reaction to RRKN, as reported in our earlier study. We generated an F2:3 population from the cross of PB1121/PR and evaluated it for RRKN resistance-related traits under artificial inoculation conditions. The distribution pattern of traits in the F2:3 population indicated that resistance may be governed by a few major-effect genes and many minor-effect genes. The molecular markers reported to be associated with QTLs governing RRKN resistance traits were used to test in the current population. Although the simple linear regression identified significant associations between the markers and RRKN resistance-associated traits, these associations were spurious as the LOD score was below the threshold limit. This indicates that PR possesses novel genomic regions for resistance to RRKN as it does not possess any of the earlier reported QTLs.

Extracellular microRNAs associated with psychiatric symptoms in the Normative Aging Study

Earlier studies have revealed microRNAs (miRNAs) as potential biomarkers for neurological conditions, however, such evidence on psychiatric outcomes is limited. We utilized the Normative Aging Study (NAS) cohort to investigate the associations between extracellular miRNAs (ex-miRNA) and psychiatric symptoms among a group of older male adults, along with the targeted genes and biological pathways. We studied 569 participants with miRNA profile primarily measured in extracellular vesicles isolated from plasma, and psychiatric symptoms reported over 1996–2014 with repeated measures. Global and dimension scales of psychiatric symptoms were measured via the administration of Brief Symptom Inventory (BSI) per visit covering nine aspects of psychiatric health, such as anxiety, depression, hostility, psychoticism, etc. Ex-miRNAs were profiled using small RNA sequencing. Associations of expression of 395 ex-miRNAs (present in >70% samples) with current mental status were assessed using single-miRNA as well as Least Absolute Shrinkage and Selection Operator (LASSO)-based multi-miRNAs linear mixed effects models adjusting for key demographic and behavioral factors. Biological functions were explored using pathway analyses. We identified ex-miRNAs associated with each BSI scale. In particular, hsa-miR-320d was consistently identified for two global scales. Similar overlapping miRNAs across global and dimension scores included hsa-miR-379-3p, hsa-miR-1976, hsa-miR-151a-5p, hsa-miR-151b, hsa-miR-144-3p, etc. Top KEGG pathways for identified miRNAs included p53 signaling, Hippo signaling, FoxO signaling, protein processing in endoplasmic reticulum and several pathways related with cancer and neurological diseases. This study provided early evidence supporting the associations between extracellular miRNAs and psychiatric conditions. MiRNAs may serve as biomarkers of subclinical psychiatric illness in older adults.

NUMERICAL SOLUTIONS OF BOUSSINESQ TYPE EQUATIONS BY MESHLESS METHODS

In this paper, two different meshfree method with radial basis functions (RBFs) is proposed to solve Boussinesq-type (Bq) equations. The basic conservative properties of the equation are investigated by computing the numerical values of the motion’s invariants. The accuracy of the method is tested using computational tests to simulate solitary waves in terms of L_∞ error norm. The outcomes are contrasted with analytical solution and a few other earlier studies in the literature. The results show that meshless methods are very effective and accurate.

Dynamics of natural hazard risk awareness: Panel analysis insights from Switzerland

The analysis of risk awareness should be the initial stage in integrated natural hazard risk management to promote appropriate and effective measures for mitigating risks and strengthening social resilience inside the multi-risk framework. Nevertheless, earlier studies focused on cross-sectional data and overlooked the changes in risk awareness levels and associated independent variables with time. This study analyzes for the first time a balanced nationwide panel dataset of 1612 respondent-year observations from Switzerland (period 2015–2021, including the epidemic of COVID-19) to examine and compare the effects of potential independent variables on the four dimensions of natural hazard risk awareness (NHRA), ranging from the broadest dimension of Relevance to higher dimensions of Perceived Probability of an event, Perceived Threat to life and valuables, and Perceived Situational Threat. The analysis in this study incorporates multiple methods of Random-Effect Model (RE), Generalized Linear Model (GLM), and mediation analysis. Results show that NHRA increased in Switzerland to different extents (up to 23.24%) depending on the dimension. Event memory, perceived information impact and reported individual informed level appeared to be the most consistent independent variables positively influencing panel NHRA. Among these, perceived information impact as an important indicator of risk communication, was also found to serve as a mediator from risk preparedness to risk awareness. By encouraging residents to engage in “Begin Doing Before Thinking” (BDBT) programs to leverage subliminal effects and self-reflection, this study proposes that behavior-cognition feedback loops may facilitate a virtuous cycle. Our promising observations provide recommendations for an effective awareness-rising strategy design and suggest extensive insights from potential short-interval panel analysis in the future.

Molecular phylogenetic reassessment of eastern Atlantic Callinectes (Brachyura, Portunidae)

Abstract Several species from the genus Callinectes are economically important, yet the number of species and their geographic distributions remain unclear. Recently, one of the American species, Callinectes larvatus, was synonymized with one of the African species, C. marginatus, making C. marginatus the only species of the genus regarded to be amphi-Atlantic in distribution. However, there was no formal taxonomic study to support this taxonomic change, which was in contradiction to earlier studies that had provided morphological characters to support the taxonomic separation of the eastern Atlantic species from those of western Atlantic distribution. Callinectes maracaiboensis has also been questionably resurrected. Here we present a molecular based analysis for all species of Callinectes, using the two common mitochondrial genes 16S and 12S. Our molecular data support the presence of three eastern Atlantic, three eastern Pacific, and nine western Atlantic species. Historically, it appears that the separation of Africa and South America with the opening of the Atlantic basin gave rise to sister species distributed on opposite sides of the Atlantic Ocean. In a second isolation event, the emergence of the Panamanian isthmus resulted in pairs of geminate species distributed in eastern Pacific and western Atlantic waters.

Evaluation of hydrothermal carbonization of biomass residues for bioenergy: A life-cycle based comparison against incumbent technologies

Hydrothermal carbonization of biowaste with energy recovery was evaluated as a biowaste treatment technology using attributional life cycle assessment carried out in line with ISO 14044. Results show that important differences were observed for individual impact categories. Hydrothermal carbonization outperformed all other incumbent technologies in three impact categories and performed on par with anaerobic digestion and composting in the climate change category, where impact scores across three different wet biowaste streams ranged from -0.014 to -0.032 kg CO2 equivalents per kg of wet biowaste treated. However, it performed the worst in those environmental impacts which address resource depletion, including mineral, fossil and renewable resource depletion. This stresses the need to include all impact categories when evaluating environmental performance of biowaste treatment technologies. Differences in the ranking between different midpoint categories corroborate earlier studies suggesting that the general waste hierarchy might not necessarily apply to hydrothermal carbonization of biowaste.

Concurrent and longitudinal associations between touchscreen use and executive functions at preschool-age

IntroductionThe prevalence of touchscreen devices has recently risen amongst young children. Some evidence suggests that increased touchscreen use may be negatively related to preschool-age children's executive functions (EFs). However, it has been argued that actively interacting with touchscreen devices (e.g., via creative apps for drawing) could better support EF development compared to passive use (e.g., watching videos). There is a pressing need to understand whether the type of use can explain potential associations between touchscreen use and EF.MethodsBy following up longitudinally on an infant sample, now aged 42-months (N = 101), the current study investigates the relative contributions of passive and active touchscreen use, measured concurrently at 42-months and longitudinally from 10-to-42-months, on parent-reported EFs.ResultsA multivariate multiple regression found no significant negative associations between touchscreen use and preschool EF. There was a significant positive association between active touchscreen use at 42-months and the BRIEF-P Flexibility Index.DiscussionThe lack of significant negative associations found is consistent with an earlier study's findings in the same sample at infancy, suggesting that the moderate levels of early touchscreen use in this sample are not significantly associated with poorer EF, at least up to preschool-age.

Decoding regressive depositional history from the Neoproterozoic Panium Sandstone Formation, Kurnool Group, India using ‘sequence stratigraphy’ analysis and detrital zircon geochronology

The Neoproterozoic Panium Sandstone Formation of the Kurnool Group (India) offers a unique scope for understanding regressive depositional history in a Neoproterozoic clastic shoreline. It is divided into two ‘Systems Tracts’ namely forced regression and lowstand. Process-based facies and paleo-environmental analysis identified twelve different facies types; grouped under four facies associations (FA I–IV) belonging to both continental and shallow-marine domains viz. distal braided fluvial, swash bar-foreshore runnel, upper shoreface bar-trough, and lower shoreface bar-interbar. Whereas the fluvial deposit (FA I), sharply and erosionally overlying the argillaceous shelf succession of the Owk shelf shale, represents the product of forced regression, the wave-dominated shallow marine deposits (FA II, III and IV) record the depositional history of lowstand in the coastline. A basin ward transition from unconformity (base of FA I) to correlative conformity (base of shallow marine deposits FA II, III, and IV) is documented. The shoreline had a north-northwest to south-southeast alignment and the north-eastward flowing fluvial system met the shoreline at a high angle. Detrital zircon geochronology from the Panium fluvial sandstone allowed documentation of Paleoproterozoic (~2050 Ma–1800 Ma) and Mesoproterozoic (~1500 Ma to ~1200 Ma) age clusters, in addition to earlier documented age clusters from the Banganapalle alluvial sandstone present at the basal part of Kurnool succession. The new age data suggest an addition of new provenances and in turn, tectonic intervention behind the regression in the Kurnool coastline that triggered Panium deposition. Further, the Paleoproterozoic age cluster, obtained from the Panium fluvial deposit, helped in the justification of solitary zircon grain occurrences within the Owk Shale, as described in earlier studies.

Resource allocation for practical phase shift STAR-RIS enabled MISO-NOMA wireless network with non ideal hardware

This study investigates the sum secrecy rate SRsum of a simultaneous transmission and reflection reconfigurable intelligent surface (STAR-RIS)-enabled multiple input single-output (MISO) non-orthogonal multiple access (NOMA) downlink network with non-ideal hardware defects (HWDs) at the transceivers. Earlier STAR-RIS studies assumed an ideal phase shift model, with each element reflect and transmit the signal without regard to its phase shift. The proposed practical phase shift model accounts for the phase-dependent amplitude variation in the reflection and transmission (RAT) coefficients. The goal is to maximize the SRsum through an alternating optimization (AO) iterative algorithm, leverages a classical semidefinite relaxation (SDR) for beamformer vector design (BVD), and employs an interior point method (IPM) to calculate NOMA power allocation factors αt,αr. The analysis focuses on the evaluation of the SRsum in scenarios with eavesdroppers, under the consideration of both ideal and practical phase shift cases. The study examines the impact of different non-ideal HWDs on the SRsum of the system and provides insights into vulnerabilities and limitations arising from these effects.