Index Values Research Articles

Trees have similar growth responses to first-entry fires and reburns following long-term fire exclusion

Managing fire ignitions for resource benefit decreases fuel loads and reduces the risk of high-severity fire in fire-suppressed dry conifer forests. However, the reintroduction of low-severity wildfire can injure trees, which may decrease their growth after fire. Post-fire growth responses could change from first-entry fires to reburns, as first-entry fires reduce fuel loads and the vulnerability among trees to fire effects, which may result in trees sustaining less damage during reburns. To determine whether trees had growth responses that varied from first-entry fires to reburns, we cored 87 ponderosa pine trees in the Gila Wilderness, New Mexico, USA that experienced 3–5 fires between 1950 and 2012 following long-term fire-exclusion and 67 unburned control trees from the Gila and Apache-Sitgreaves National Forests. We assessed tree growth response to fire by comparing tree-ring growth among burned and unburned trees from two years before to two years after fires. We compared growth between burned and unburned trees using a bootstrapping procedure to calculate annual median tree-ring width index values with 95 % confidence intervals. We compared post-fire growth after first-entry fires and reburns following long-term fire-exclusion. Burned trees had similar growth responses following first-entry fires and reburns, with lower growth during the fire year through two years post-fire compared to unburned controls. Burned tree growth returned to expected rates following these immediate post-fire growth reductions. Interestingly, trees had lower growth during the year before and the year of reburns compared to the first-entry fire, reflecting greater aridity before reburns. Greater aridity may have contributed to larger-than-expected growth reductions following reburns, which could explain similar growth responses to first-entry fires and reburns. Our results indicate that trees had consistent short-term growth responses to low-severity fires following long-term fire-exclusion. As trees retained vigor after multiple fires, managing fires for resource benefit is an effective approach to reduce the likelihood of high-severity fire without long-term negative effects on tree growth.

A recycled crushed rock sand mortar based on Talbot grading theory: Correlation of pore structure and mechanical properties

The use of crushed rock sand (CRS) as a substitute for natural sand is a necessary and feasible approach to address depletion of natural sand resources. This study investigated the effect of CRS aggregate gradation, based on Talbot grading theory, on pore structure and mechanical properties of mortar. 10 CRS mortars with different Talbot gradations were prepared, and quantitative relationships between Talbot gradation, pore characteristics (size distribution, fractal dimensions, and pore connectivity), acoustic emission (AE) characteristics, and compressive mechanical properties were analyzed using nuclear magnetic resonance (NMR) and AE techniques. The optimal Talbot index value was determined to be 0.4, based on the observed changes in pore structure and mechanical properties. Furthermore, the influence of Talbot index on internal damage process of CRS mortar was analyzed in conjunction with AE characteristics, and a prediction model for mortar strength was established based on porosity and AE cumulative counts. The correlation between pore structure, AE characteristics and mechanical properties of CRS mortar under Talbot grading was systematically investigated, which provides theoretical support for optimal design of CRS mortar materials. The application of Talbot grading theory in design of mortar is explored to provide a scientific basis for improvement of mortar engineering performance.

Linking feed, biodiversity, and filtration performance in a Self-Forming Dynamic Membrane BioReactor (SFD MBR) treating canning wastewater

A bench-scale self-forming dynamic membrane bioreactor (SFD MBR) treating canning wastewater showed instable filtration performance, with a worsening in correspondence of a change in the influent quality. To unveil the possible reasons for such behaviour, a microbial investigation was carried out to complement conventional filterability and settleability tests. The microbial communities of the influent wastewater, the activated sludge, and the filtering sludge cake (dynamic membrane) were characterised through metagenomic and differential abundance analyses. In parallel, the production of exopolymers was measured. The outputs indicate that under the tested conditions the canning wastewater promoted the development of a very peculiar microbial ecosystem, with a strong selection of the genus Thiothrix (relative abundance above 90 %). The Shannon index values in activated sludge were below 2, indicating a very low bacterial diversity. This may have limited the ecosystem resilience towards changes of external conditions, causing instability in the process of the dynamic membrane formation. Furthermore, the diversity analysis showed that the bacterial compositions of the feed and the sludge resulted not significantly linked to each other, confirming the main role of the chemical composition of the influent wastewater on overall process performances. When treating agro-industrial streams, in-depth feed characterisation is recommended in order to prevent the factors that may generate instability in SFD MBR performance.

Systemic immune-inflammation index combined with pediatric appendicitis score in assessing the severity and prognosis for paediatric appendicitis.

Pediatric appendicitis is a common cause of abdominal pain in children and is recognized as a significant surgical emergency. A prompt and accurate diagnosis is essential to prevent complications such as perforation and peritonitis. To investigate the predictive value of the systemic immune-inflammation index (SII) combined with the pediatric appendicitis score (PAS) for the assessment of disease severity and surgical outcomes in children aged 5 years and older with appendicitis. Clinical data of 104 children diagnosed with acute appendicitis were analyzed. The participants were categorized into the acute appendicitis group and chronic appendicitis group based on disease presentation and further stratified into the good prognosis group and poor prognosis group based on prognosis. The SII and PAS were measured, and a joint model using the combined SII and PAS was constructed to predict disease severity and surgical outcomes. Significant differences were observed in the SII and PAS parameters between the acute appendicitis group and chronic appendicitis group. Correlation analysis showed associations among the SII, PAS, and disease severity, with the combined SII and PAS model demonstrating significant predictive value for assessing disease severity [aera under the curve (AUC) = 0.914] and predicting surgical outcomes (AUC = 0.857) in children aged 5 years and older with appendicitis. The study findings support the potential of integrating the SII with the PAS for assessing disease severity and predicting surgical outcomes in pediatric appendicitis, indicating the clinical utility of the combined SII and PAS model in guiding clinical decision-making and optimizing surgical management strategies for pediatric patients with appendicitis.

Interpretation of Microtremor Data Through Analysis Horizontal to Vertical Spectral Ratio (HVSR) for Microzonation of Seismic Earthquake Hazards in Baubau City

Research has been carried out on seismic hazard microzonation in the city of Bau – bau using microtremor data. The aim of this research is to determine the seismic vulnerability index based on horizontal to vertical spectral ratio (HVSR) analysis and create a dominant frequency microzonation map (F0), dominant period map (T0), amplification factor map (A0), and seismic vulnerability index map (Kg) from microtremor data which can describe the level of vulnerability of an area to seismic hazards. Microtremor measurements were carried out using a portable three-component seismograph (TDS. 303), the data was analyzed with gepsy software via the HVSR method. The research results show that the distribution of dominant frequency values ​​(F0), ranges from 0.4795 Hz to 16.6383 Hz, dominant period values ​​(T0), ranges from 0.0601 seconds to 2.0854 seconds, amplification factor values ​​(A0), ranges from 1.2285 to 4.9043, and the seismic vulnerability index (Kg) value ranges from 0.1043 to 11.0276. The values ​​(F0), (T0), (A0), and (Kg) are interpreted by referring to literature data and surface geological maps of the research area. The results show that the study area has a small portion of sediment layers that are vulnerable to seismic hazards.

Evaluation of physicochemical parameters as indicators of diesel adulteration

Diesel adulteration not only reduces engine performance and lifespan but also has a stiffening effect on the economy. Therefore, regulatory agencies and petroleum laboratories are constantly adopting various methods to ensure that commercial diesel is pure and of good quality. Despite the introduction of solvent tracer analysis as a reliable means of detecting adulteration, most laboratories still depend on the physicochemical parameters of diesel as an indicator of adulteration. This research aimed to document the feasibility of using quality parameters to detect diesel adulteration. Neat diesel samples were mixed with some common adulterants (kerosene, premix, and condensate) at varying concentrations. The quality of each admixture was analysed using the ERASPEC fuel analyser and physicochemical parameters including density, kinematic viscosity, cetane index, and flashpoint were recorded. A negative correlation was observed between adulteration and all quality parameters. At low levels of adulteration, physicochemical parameters were within the required range. However, diesel with adulterants above 20 % v/v had cetane index, density, and flashpoint values not conforming with quality standards. Kinematic viscosity of diesel remained within the required limits despite the levels of adulteration. Physicochemical parameters, though generally accepted as good indicators of fuel quality, were not reliable indicators of diesel adulteration, especially at low levels. At higher levels of adulteration, the type of adulterant present must be considered if physicochemical parameters are to be used to predict adulteration. However, it is recommended that physicochemical parameters be used in combination with other techniques to detect diesel adulteration.

The influence of physical vapor deposition (PVD) coating on the microgeometry of high-speed steel (HSS) cutting tools during the machining of wood-based composites

ABSTRACT The aim of this work was to analyze the impact of a multilayer TiN/AlTiN nano coating deposited using the physical vapor deposition (PVD) method on the microgeometry and durability of replaceable knives made of high-speed steel (HSS). The blunting process took place while milling standard medium density fireboard with a thickness of 16 mm. Seven reference knives and seven coated ones were used. During durability tests, the wear index value, i.e. the maximum wear on the clearance face VBmax = 0.3 mm was adopted as the blunting criterion. After the blunting stage, the tools were subjected to a precise geometric analysis based on a contact profilometer. In this way, a number of geometric parameters and rounding factors K were obtained for coated and uncoated blades at various points along the cutting edge on a distance 10 mm with 0.5 mm increments. Then, these data were subjected to statistical analysis using the Bonfferoni method. The results showed statistically significant changes in the values of some asymmetry coefficients K at the stage of tool lapping.

TURKISH VALIDITY AND RELIABILITY OF THE POUND SATISFACTION SCALE IN STROKE PATIENTS UNDERGOING REHABILITATION

Purpose: This study aimed to evaluate the Turkish validity and reliability of the Pound Satisfaction Scale (PSS). Methods: For the adaptation of the PSS to Turkish (PSS-Tr), the translation and back-translation process was carried out by following the international guidelines. Confirmatory factor analysis (CFA) was performed to measure structural validity. The relationship between PSS-Tr and the Patient Satisfaction Scale in Physiotherapy (PSSP) and the SF-36 was assessed for construct validity. Convergent validity was evaluated computing by the Average Variance Extracted (AVE). Cronbach's alpha coefficient and Composite reliability (CR) for internal consistency of the PSS-Tr and Bland-Altman plot and test-retest reliability analysis for temporal consistency were used. Results: The study included 130 stroke patients. The fit index values of the CFA showed that the structural validity of the PSS-Tr was appropriate (χ2/sd=1.779, RMSEA=0.075, GFI=0.911, AGFI=0.853, CFI=0.955, NFI=0.905). A high correlation was found between the PSS-Tr total score and the PSSP (p=0.001, r=0.672). A moderate correlation was found between the hospital satisfaction sub-dimension of PSS-Tr, and the sub-dimensions of SF-36 (p=0.001, r=0.484-0.609), while a low correlation was found between the home satisfaction sub-dimension of the PSS-Tr and the physical functioning (p=0.002, r=0.266) and physical role (p=0.035, r=0.180) sub-dimensions of SF-36. And also the PSS-Tr was found to have good internal (Cronbach alpha= 0.895, CR=0.94) and temporal consistency (ICC = 0.976). Conclusion: The Turkish version of the Pound Satisfaction Scale (PSS-Tr) is reliable and valid. The PSS-Tr may be useful for clinicians and researchers in assessing satisfaction with rehabilitation in stroke patients.

Comparative characteristics of patients with a combination of obstructive sleep apnea and paroxysmal atrial fibrillation in the groups of interventional and conservative treatment of arrhythmia

Aim. To compare the clinical characteristics of two groups of patients with a combination of obstructive sleep apnea (OSA) and paroxysmal atrial fibrillation (AF), undergoing conservative treatment for arrhythmia and after pulmonary vein isolation.Material and methods. The study included 362 patients with paroxysmal AF who underwent respiratory sleep monitoring.Results. A predominance of clinically significant OSA was revealed (moderate and severe — 37% and 29%, respectively), as well as a higher drug burden and comorbidity in the group of patients receiving drug treatment for AF. The threshold value of body mass index (BMI), at which a high risk of severe OSA was predicted, corresponded to class 1 obesity (BMI ≥31 kg/m2). The results obtained demonstrated an association between an increase in the left atrium anteroposterior size and the severity of OSA (4,1 [3,8-4,4] cm, r=0,28; p<0,001), which may be due to cardiac structural remodeling in patients with a combination of paroxysmal AF and severe OSA.Conclusion. In a cohort of patients with paroxysmal AF, a high incidence of clinically significant OSA was revealed. In the group of patients with a combination of OSA and AF undergoing conservative treatment, more unfavorable cardiovascular characteristics and a more severe comorbid status were revealed compared to the group of patients undergoing surgical treatment.

Elemental Profiling with Reference to Metal Index to Study Pollutant Load in Northern River of India

Present light was to determine elemental load in Sirsa river ecosystem to know the concentration of toxicants in this Sutlej river’s tributary that act as a gutter for industrial effluents of Baddi region. The inductively coupled plasma mass spectroscopy was used to detect concentration of elements in the department of biochemical engineering and biotechnology at IIT Delhi and the collected data was further analyzed statistically using one way ANOVA at (p≤0.05) followed by post hoc Duncan’s test to predict degree of variations and comparative profile in Table 1. The application of metal index was also performed to estimate water quality and co-related it with health hazards. Variations in concentration of elements was reported near common effluent treatment plant on pollutant Nallah (S2) in deceasing order read as Mg>Na>Ca>B>Zn>Cu>Mn>Fe>Mo>Al>Tl>Se in ppb. The concentration of elements reported at S1, S2, S3 were within permissible limit of WHO and Bureau of Indian Standards, except the value of Boron, Magnesium and Thallium were exceeded these guidelines constantly at site S2 of study area.The metal index values at S1, S2 and S3 were 1.55, 5.80 and 2.57 respectively. The site S2 was affected strongly due to presence of elemental dust and un-treated waste water discharged by chemical industrial units of Baddi region. This site (S2) was nearer to common effluent treatment plant on the bank of Sirsa river and found to be unsuitable at all with more value of metal index. It was also viewed to adopt such scale indices to estimate drinking water quality with respect to concentration of elements after equal interval of time; as there may be seasonal change in the load of debris due to rate of pollutants dumping in the riverine ecosystem which is directly proportional to the content of elements. The load of pollutants in water system was underlined to know the impact of inorganic waste discharges on water quality of river in this region of Himachal Pradesh along industrial belt.

Prediction of in-hospital mortality in patients with myocardial infarction and type 2 diabetes: the role of cellular indices of systemic inflammation

Aim. To assess the value of cellular indices of systemic inflammation in the prognosis of in-hospital mortality in patients with ST-segment elevation myocardial infarction (MI) in combination with type 2 diabetes (T2D).Material and methods. The retrospective case-control study included 125 patients with myocardial infarction and T2D, 25 of whom died during the index hospitalization. The cellular composition of the blood and the level of high-sensitivity C-reactive protein (hsCRP) were determined on the first and third days of hospitalization. In the groups of deceased and surviving patients, cellular indices of systemic inflammation were calculated and compared (neutrophil-lymphocyte ratio (NLR), neutrophil-monocyte ratio (NMR), monocyte-lymphocyte ratio (MLR), platelet-lymphocyte ratio (PLR), systemic inflammation index (SII), systemic inflammation response index (SIRI)) and average hsCRP levels). The prognostic role of the studied parameters was assessed using univariate and multivariate logistic regression.Results. Deceased patients, compared with survived ones, had higher Killip class, body mass index, number of stents implanted, higher hsCRP levels, and lower left ventricular ejection fraction. Inhospital mortality was associated with hsCRP (odds ratio of 1,03 with 95% confidence interval of 1,003-1,05, p=0,029), NLR (2,56 [1,73-9,78], p<0,001), NMR (1,16 [1,001-1,35], p=0,04), MLR (23,7 [3,1-182,6], p=0,002), SII (1,001 [1,0-1,001], p=0,028), SIRI (1,29 [1,09-1,52], p=0,003) 48 hours after admission, as well as with the degree of hsCRP change (1,03 [1,003-1,05], p=0,025), NLR (1,58 [1,21-2,06], p=0,001), SII (1,001 [1,0-1,001], p=0,028) during the first three days. Adjusted multivariate regression analysis identified a set of independent predictors with greatest accuracy in assessing the death probability: NLR, SII and SIRI 48 hours after admission, the degree of hsCRP change, body mass index and the num ber of implanted stents.Conclusion. The work demonstrated the significance of cellular indices of systemic inflammation (NLR, SII and SIRI) in assessing the prognosis of in-hospital mortality in patients with MI combined with T2D.

Predictive value of quantitative indexes of FDG pet in the evaluation of thyroid nodules

Predictive value of quantitative indexes of FDG pet in the evaluation of thyroid nodules

Multitemporal sentinel-1 SAR data sensitivity analysis at phenological growth stages of green gram

ABSTRACT This research investigated the green gram crop by employing a time series of Sentinel-1A Single Look Complex (SLC) and Sentinel-2 datasets, which corresponded to different phenological growth stages of the crop. Field campaigns were conducted on the acquisition dates of Sentinel-1A datasets for the entire crop cycle to estimate crop height and soil moisture. In line with these observations, temporal variations in 10 salient Synthetic Aperture Radar (SAR) parameters, obtained from Sentinel-1A datasets, are systematically analysed, which elucidated the importance of dual-polarized SAR parameters in the diverse phenological growth stages of the crop. Moreover, the Normalized Difference Vegetation Index (NDVI) values from Sentinel-2 datasets, estimated at various green gram growth stages, are categorized into initial (NDVI ≤ 0.5), intermediate (0.5 < NDVI < 0.8), and maximum growth of the crop (NDVI ≥ 0.8), which are then aligned with corresponding SAR and ground-measured parameters. The inversion model development and sensitivity analysis were carried out to correlate ground-measured parameters with SAR parameters across various growth stages based on the categorization of NDVI values as well as for the entire growing season of the crop. Backscattering intensities are found to have good sensitivity to crop height at its intermediate growth (r ≥ 0.75). Among vegetation indices, the Polarimetric Radar Vegetation Index (PRVI) showed significant sensitivity to crop height in its intermediate growth stage (r ≈ 0.77). H-A-Alpha decomposition parameters displayed notable sensitivity to soil moisture in the initial and maximum growth stages of green gram. This study demonstrates the effectiveness of Sentinel-1 dual-polarized SAR parameters in monitoring green gram phenological growth stages. The parameters show substantial sensitivity to both green gram height and soil moisture.

PVA/CMC/PEG blended polymer loaded with ZnCo1.9Al0.1O4/carbon nanoparticles/PANi as a promising films for UV radiation shielding

Polyvinyl alcohol (PVA), carboxymethyl cellulose (CMC) and polyethylene glycol (PEG) have been employed as polymeric matrices for the synthesis of polymeric nanocomposite films that incorporate ZnCo1.9Al0.1O4, carbon nanoparticles (CNPs) and polyaniline (PANI) as fillers. X-ray diffraction technique was utilized to examine the structure of ZnCo1.9Al0.1O4 filler and the formed PVA/CMC/PEG/ZnCo1.9Al0.1O4/CNPs/x wt % PANi blends. The morphology of the doped blend was explored using the scanning electron microscopy technique. The increases in absorbance, especially in the UV spectrum, demonstrate the potential of these blends in UV-blocking and UV-filtering applications. The minimum direct and direct optical energy gaps are 5.62 and 4.77 eV obtained as the quantity of PANi became 0.3 wt %. The highest refractive index values (n = 1.66 at 600 nm) were acquired as the blend was doped with 0.4 wt % PANi. The impact of different fillers on the linear and nonlinear optical parameters was explored. The inclusion of ZnCo1.9Al0.1O4/CNPs/x wt % PANi resulted in an improvement in PVA/CMC/PEG blended polymer's optical conductivity. The FL intensities of the loaded blends are comparatively lower than those of the undoped blend. The values of the dielectric constants of doped blends with x = 0 or 0.4 are notably higher than those of other blends. Doped blend with x = 0.2 exhibited the highest energy density value (9 × 10−3 J/m3 at 1 kHz). The doped blend with x = 0.4 has the highest ac conductivity (1.53 × 10−8 Sm−1 at 1 kHz). The influence of doping on the relaxation time and capacitance behavior of the host blend was inspected. These outcomes suggest the opportunity of employing the created nanocomposites in capacitive energy storage and optoelectronic devices.

Effect of direct water injection on knock suppressing mechanism in a high compression ratio gasoline engine

ABSTRACT A low capacity, boosted gasoline engine is an effective approach to enhancing fuel economy. However, knock combustion poses significant limitations to the practical development of these engines. This study investigated the chemical kinetics and macroscopic properties of engines equipped with direct water injection (DWI) at high compression ratios (CRs) to address knock issues. The results indicated that the generation and consumption pathways of OH and CH2O remain unaffected by water injection. Although water exhibited an opposing effect on the sensitive reactions of OH and CH2O, the production reaction rates of OH and CH2O decrease with water injection. Knock index values at each monitoring point approached zero when the water injection quality exceeds 30%. Additionally, knock suppression effectiveness improved with the advancement of water injection timing. The simulation results indicated that the knock index at high CR decreased from 13.61 to 0.27 when the water/fuel ratio exceeded 30%. The indicated specific fuel consumption decreased by 29.3%, and indicated power increased by 41.8% compared to the original engine. Although NOx and CO emissions increased because of the high CR, the water injection coupled with the compression ratio strategy limited the increase in emissions. These findings indicated that DWI coupled with high CR was advantageous to enhancing fuel economy and reducing emissions in low capacity gasoline engines.

Groundwater quality in high-sulfur coal mining region of India: Spatial distribution, source control, and health risk assessment

The groundwater quality in the vicinity of the Makum coalfield, renowned for its high-sulfur coal deposits, was investigated. The oxidation of sulfur in the coal generates acid mine drainage (AMD), a global environmental challenge that contaminates natural resources. The region's high sulfur coal content intensifies AMD formation, necessitating a comprehensive assessment of its impact on human health and the environment. This study analyzes the water quality parameters such as pH, EC, TDS, Na+, Ca+2, Mg+2, K+, HCO3‐, SO4−2, F−, Cl -, and NO3− in groundwater, findings concerning low pH levels (5.8) and fluoride concentration (0.15 mg/L) compared to standards. Groundwater chemistry was analyzed to identify the sources controlling water composition through Gibbs diagrams, Piper diagrams, and saturation indices. The Gibbs diagram shows that rock weathering is the crucial factor controlling groundwater chemistry, while the Piper diagram indicates Ca-Cl as the Principal water type. Additionally, an in-depth analysis of groundwater chemistry reveals that carbonate dissolution primarily occurs due to minerals like calcite, dolomite, and gypsum, findings supported by saturation indices. The present study yielded an average water quality index of 40.19, indicating excellent to good water quality in 51 out of 52 samples analyzed. The average hazard index values for adults and children were 0.60 and 0.58, respectively, indicating that 49 of 52 samples pose negative non-carcinogenic risks associated with nitrate and fluoride contamination. The irrigation indices, graphical representations such as the Wilcox and Doneen classification, and the USSL diagram elucidate the suitability for irrigation purposes. Moreover, the Principal Component Analysis identified the sources of ions as originating from geogenic processes and mining activities. The study stresses environmental assessments, health risk management, and sustainable practices for groundwater in high-sulfur coal mining areas.

Comparing the seasonal relationship of land surface temperature with vegetation indices and other land surface indices

ABSTRACT Land surface temperature (LST) is largely influenced by various biophysical properties of land surface materials, especially in urban areas where multiple spectral bands directly impact LST. The present study compares the seasonal relationship of LST with six vegetation indices, one built-up index, one water index and one soil index in Imphal City, India, using Landsat 8 satellite images from the summer and winter of 2021. The study found that these nine indices exhibit different responses to changes in LST in urban landscapes. Pearson’s correlation coefficient, scatter plot graphs, box plot graphs, and cross-section drawings are used to present the relationships between LST and the indices. The study discovered that all six vegetation indices show a moderate negative relationship with LST in both summer and winter. Additionally, the water index demonstrates a weak negative relation in summer and a moderate negative relation in winter. The built-up index shows a neutral relation in summer and a weak positive relation in winter, while the soil index forms a weak positive relation in summer and a moderate positive relation in winter. Further analysis presents that higher values of vegetation indices correspond to lower LST, while built-up and bare surfaces generate high LST.

Ecotoxicological, ecological, and human health risks of total carbohydrates and some inorganic pollutants on the Nile Delta region along the Egyptian Mediterranean Coast

This is one of few studies dealing with the potential impact of total carbohydrates (TCHO), and some inorganic pollutants (F, B, As, V, Se) on human health. Additionally, the latter pollutants toxicological and ecological effects on the Egyptian Mediterranean Coast, especially, the Nile Delta region, were investigated. Both F (0.18 ± 0.09 mg/g) and As (2.47 ± 5.39 μg/g) were of lower concentrations compared to previous reports. Values of all ecological and ecotoxicity indices, particularly, the risk quotient (RQ), showed that arsenic had the most adverse biological effects on three trophic levels (algae, invertebrates, and fish). Children and adults non-carcinogenic hazard index (HI) values were <1, revealing that sediments in the studied area would pose no risk to humans. However, arsenic carcinogenic risk (CR) values exceeded the maximum permissible limits, implying risk to children and adults. These findings could anticipate toxic impacts of polluted effluents on the Nile Delta region.

Functional characterisation and modification of a novel Kunitzin peptide for use as an anti-trypsin antimicrobial peptide against drug-resistant Escherichia coli

In recent decades, antimicrobial peptides (AMPs) have emerged as highly promising candidates for the next generation of antibiotic agents, garnering significant attention. Although their potent antimicrobial activities and ability to combat drug resistance make them stand out among alternative agents, their poor stability has presented a great challenge for further development. In this work, we report a novel Kunitzin AMP, Kunitzin-OL, from the frog Odorrana lividia, exhibiting dual antimicrobial and anti-trypsin activities. Through functional screening and comparison with previously reported Kunitzin peptides, we serendipitously discovered a unique motif (−KVKF-) and unveiled its crucial role in the antibacterial functions of Kunitzin-OL by modifying it through motif removal and duplication. Among the designed derivatives, peptides 4 and 8 demonstrated remarkable antimicrobial activities and low cytotoxicity, with high therapeutic index (TI) values (TI4 = 20.8, TI8 = 20.8). Furthermore, they showed potent antibacterial efficacy against drug-resistant Escherichia coli strains and exhibited lipopolysaccharide (LPS)-neutralising activity, effectively alleviating LPS-induced inflammatory responses. Overall, our findings provide a new short motif for designing effective AMP drugs and highlight the potential of the Kunitztin trypsin inhibitory loop as a valuable motif for the design of AMPs with enhancing proteolytic stability.

PISA Maths-Reading index and its relationship with gender and levels of performance

The Spanish PISA 2018 students sample (>35,900 fifteen-year-old students) has been analysed by calculating the Mathematics minus Reading scores of all individuals in the sample, relating this Maths-Reading index to the personal and educational characteristics of the respondents. Results of the first step of the analysis show that the positive Maths-Reading Index values (higher scores in maths than in reading) are mainly related to gender, and negative values (higher scores in reading) are mainly related to the joy of reading and to a series of factors linked to interest and respect for other cultures, among others. Subsequently, the individual level of global performance is taken into account with a cluster analysis generating groups of high, medium and low performers. Changes in factors affecting the Maths-Reading index when this level-based grouping is considered are analysed, showing the importance of grade repetition for low performers and the influence of socio-economic factors for medium performers, while high performers are affected especially by non-cognitive aspects such as self-concept or expected occupational status. Finally, combined effects of gender and level of performance are taken into account, showing that the factors affect male and female students differently for the disparate performance-based groups. This study contributes to a more precise knowledge of the main factors associated with students’ tendency to have better scores in mathematical items than in reading items or vice versa, and to distinguish the differential role of personal and environmental factors not only globally, but also when gender and performance levels are taken into account. Studying this personal tendency is significant as it is related to students’ study choice, especially Science-Technology-Engineering-Mathematics (STEM) degrees.