Production Ratio Research Articles

Thermal degradation kinetics and purification of C-phycocyanin from thermophilic and mesophilic cyanobacteria

The natural blue colorant C-phycocyanin (C-PC) has many potential applications but its poor heat stability limits its commercial use. This study compares the production and thermal stability of C-PC from two cyanobacteria: the thermophilic Thermosynechococcus sp. TUBT-T01 and the mesophilic Synechococcus cedrorum TISTR8589. Thermosynechococcus sp. produced nearly 1.9-fold more C-PC than S. cedrorum. Batch adsorption using a chromatographic cationic ion exchange resin (Streamline Direct HST1) was used to effectively purify the C-PC. The equilibrium adsorption capacity (Qeq) of the resin for C-PC was the highest at pH 5. At this pH, the Qeq for the thermophilic C-PC was 5.5 ± 0.1mgmL⁻¹, whereas for the mesophilic C-PC it was 1.5 ± 0.2mgmL⁻¹. Purification increased the concentration of the thermophilic C-PC by 5.9-fold, and that of mesophilic C-PC by 4.2-fold. The purity ratios of the final products from the two cyanobacteria were similar at ~2.2. At 60 °C and pH 7, the C-PC of Thermosynechococcus sp. had ~12-times longer half-life than the mesophilic C-PC; however, the productivity of the thermophilic C-PC was comparatively low because of a low biomass productivity of Thermosynechococcus sp.

The effect of subsidies and reform options on profit efficiency of trout farms: Focus on energy subsidies

Energy and imported trout egg subsidies hold a pivotal role for Iranian trout farms. They aim to decrease production costs, yet their impact on the profit efficiency of farms remains dubious. The first objective of this paper is to assess how the current subsidy scheme affects the profit efficiency of hatchery and propagation trout farms in Mazandaran, Iran. We examine several subsidy reform scenarios to enhance profit efficiency as a second objective. Standard profit efficiency (SPE) is used to acquire the efficiency of the trout farms using data envelopment analysis. Results show that the majority of farms are inefficient and highly dependent on subsidies. Comparing farms with high efficiency against those with low efficiency as a third aim of research highlights the importance of farms holding a propagation license, engaging in vertical integration, achieving adult trout production surpassing 81 t, and maintaining a fish total feed consumption to trout production ratio below 0.74. Findings from reformation scenarios reveal 1) redirecting the current subsidy towards purchasing the extruder machines for fish feed production, 2) transferring funds to subsidize electricity based on the farm's electricity consumption, and 3) opting for the production of genetically modified eggs gives higher SPE. Reformation can also reduce the burden on public funds and dependency on importation.

THE INFLUENCE OF STOCKING DENSITIES ON WHITE SHRIMP (Litopenaeus vannamei) REARED USING INTENSIVE SYSTEM: PRODUCTION PERFORMANCE AND WATER QUALITY

ABSTRACT The increasing trend of vaname shrimp cultivation production encourages farmers to increase their cultivation production. The success of vaname shrimp cultivation can be seen from the ability to measure the capacity of shrimp biomass in maintenance activities and stocking density patterns based on the maximum capacity of the pond in each plot. The purpose of this study was to analyze vaname shrimp cultivation activities for a period of 2 years (2023-2024) in intensive system ponds based on different stocking density patterns at 140 shrimp/m2 and 190 shrimp/m2. This study was carried out for 6 cultivation cycles, each cycle was carried out for 100 days. The results of statistical tests showed that the shrimp stocking density pattern had a significant effect (p <0.05) on biomass, productivity, survival and feed conversion ratio. The average survival rate of 140 shrimp/m2 stocking density was 85.33%, biomass was 3,327.75 kg, FCR was 1.44 and productivity was 30.8 tons/ha. The average survival rate with a stocking density of 190 shrimp/m2 was 73.66%, biomass 1,981.87 kg, FCR 1.59 and productivity 12.38 tons/ha. This shows that biomass, SR, and productivity decreased while FCR tended to increase in cultivation with a stocking density of 190 shrimp/m2. The results of water quality showed an increase in the Total Organic Matter value of 110-250 mg/l at a stocking of 190 shrimp/m2. This shows that there is an increase in organic matter in the maintenance pond which affects the survival of shrimp in the pond so that it affects the biomass and productivity of whiteleg shrimp. A stocking density of 140 shrimp/m2 can be recommended for application in intensive whiteleg shrimp cultivation. Keywords: intensive system, stocking density, water quality, whiteleg shrimp

Онтогенез та індивідуально-групові параметри Cirsium erisithales (Jacq.) Scop. (Asteraceae) в Українських Карпатах

The article deals with ontogeny and individual and group parameters of an infrequent mountain species Cirsium erisithales (Jacq.) Scop. in the Ukrainian Carpathians. Isolated populations of C. erisithales in a wide high altitudinal range of 1040–1730 m a.s.l. were studied. Four periods and 8 age stages are defined in the ontogeny of this species. Characteristics of different age states are established. The total life span of C. erisithales is long. Unfavourable conditions cause shortening of ontogeny due to reduction or skipping of some periods. Population recruitment is performed by seed reproduction. The species has high parameters of seed reproduction, particularly germination rate and potential seed productivity. Thin-tussock or barren loci are most favourable for the establishment and successful development of seedlings. It is one of the few species, which can inhabit the schist screes. Individual and group parameters of C. erisithales do not significantly depend on the altitude above sea level. It was established that C. erisithales mostly has a low density. It is the highest in the high-mountain population on Mt. Hoverla. The height of generative shoot, width and length of leaf are significantly higher in the population in the place of Babyna Yama. Number of leaves and inflorescences are similar in all of the studied populations. The height of generative shoot is most variable. Percentage of generative group varies within 20–45 %. It was determined that considerable anthropogenic impact (particularly mechanical disturbance of herbaceous vegetation) results in the shrinkage of the area of populations and significant decrease in individual and group parameters, namely height of shoot and width of leaf – by 2, length of leaf – almost by 3, number of leaves – by over 3, real to potential seed productivity ratio – almost by 4, real seed productivity – by 5, number of capitula – almost by 6, harvest of seeds – by 26 times. Factors, which adversely effect the replenishment of C. erisithales are: timber skidding, road laying, recreation, excessive sodding, large land- and rockslides, inflorescense consumption by animals etc.

{110} Surface-Exposed Bi3.15Nd0.85Ti3O12 Ferroelectric Nanosheet Arrays on Porous Ceramics as Efficient and Recyclable Piezo-Photocatalysts.

Bismuth-layered ferroelectric nanomaterials exhibit great potential for piezo-photocatalysis. However, a major challenge lies in the difficulty of recovering the catalytic powders, raising concerns regarding secondary pollution of water. In this work, a novel hierarchical porous ferroelectric ceramic containing {110} surface-exposed Bi3.15Nd0.85Ti3O12 (BIT-Nd) nanosheet arrays is grown on a porous ceramic matrix for efficient and recyclable piezo-photocatalysis. By controlling the BIT-Nd loading level of the nanosheets, the piezo-photocatalytic degradation efficiency of a Rhodamine B(RhB)(C0 = 10 mgL-1) solution reached an optimum value of 97.1% in 100 min with a first-order kinetic rate constant, k, of up to 0.0321 min-1 in Bi3.15Nd0.85Ti3O12-20 (BITNd-20) with a mass ratio of hydrothermal products to ceramics of 20%. In the presence of BITNd-20, a surprising H2 yield rate of 130 µmol·h-1 is achieved without using anycocatalyst or scavenger. Specially, the beneficial role of snowflake structures on piezoelectric potential amplification and introducing nanosheets with exposed {110} surfaces on hydrogen evolution reaction (HER) activity, piezoelectric potential output, and catalytic performance of porous ceramics has been revealed. This unique design strategy provides a new approach to enhance the piezo-photocatalytic activity by addressing environmental issues and enhancing catalytic performance to yield cleaner energy.

Comprehensive Characterization and Impact Analysis of Interlayers on CO2 Flooding in Low-Permeability Sandstone Reservoirs

In low-permeability sandstone reservoirs (LPSR), impermeable interlayers significantly challenge carbon capture, utilization, and storage (CCUS) and enhance oil recovery (CO2-EOR) processes by creating complex, discontinuous flow units. This study aims to address these challenges through a comprehensive multi-faceted approach integrating geological and microscopic analyses, including core analysis, reservoir petrography, field emission-scanning electron microscopy (FE-SEM), energy dispersive spectroscopy (EDS), and well-logging response analysis, and utilizing three-dimensional (3D) geological modeling. The current comprehensive investigation systematically characterizes interlayer types, petrophysical properties, thickness, connectivity, and their spatial distribution in the reservoir unit. Numerical simulations were conducted to assess the sealing efficiency and the impact of various interlayer materials on CO2 flooding over a 10-year period. Results indicate the presence of petrophysical and argillaceous interlayers, with optimal sealing occurring in petrophysical barriers ≥ 4 m and argillaceous barriers ≥ 1.5 m thick. CO2 leakage occurs through preferential pathways that emerge in a side-to-middle and bottom-to-top direction in interbeds, with multidirectional pathways showing greater leakage at the bottom compared to the upper side within barriers. Increased interlayer thickness constraints CO2 breakthrough but reduces vertical flooding area and production ratio compared to homogeneous reservoirs. Augmented interbed thickness and area mitigate CO2 breakthrough time while constraining gravity override and dispersion effects, enhancing horizontal oil displacement. These novel findings provide crucial insights for optimizing CCUS-EOR strategies in LPSR, offering a robust theoretical foundation for future applications and serving as a key reference for CO2 utilization in challenging geological settings of LPSR worldwide.

Research the Degradation Process of Solar Panels Based on Polycrystalline Silicon in the Climatic Conditions of Uzbekistan During Several Years of Operation

The article researches the degradation processes of PV panels at the 130 kW Namangan-Pop Solar photovoltaic plant (SPVP) as a result of seasonal climate effects. All PV panels installed in the SPVP are HSL 250, JSMM 2501, SM250 PC 8 and TS-S 400 polycrystalline solar panels manufactured by South Korean companies HANHWA, JSPV, S-ENERGY and TOPSUN. Among them, degradation processes were observed in HANHWA HSL 250 type solar panels. These degradation processes have been determined based on experimental researches based on the requirements of the International Standard. The comparison of the volt-ampere characteristics and power-voltage graphs of HANHWA's defective and new unused HSL 250 solar panels are presented. In Namangan-Pop Solar photovoltaic plant, reference (Yr) and final (Yf) production during the study period are averaged 4.12 hours and 3.67 hours per year, respectively and the production ratio (PR) varies between 87.24% - 93.58% and the average annual production ratio (PR) is 87.28% and the rate of degradation of SPVP between 2015-2021 was determined to be 0.224% per year on average.

ВЛИЯНИЕ ПОГОДНЫХ УСЛОВИЙ ТЮМЕНСКОЙ ОБЛАСТИ НА СОДЕРЖАНИЕ СУХОГО ВЕЩЕСТВА В ЗЕЛЕНОЙ МАССЕ КЛЕВЕРА ЛУГОВОГО

The purpose of research is to study the influence of weather conditions in the Tyumen Region on the percentage of dry matter in the green mass of late-ripening varieties of red clover during the harvesting period. Observations were carried out on the experimental field of the Research Institute of Agriculture of the Northern Trans-Urals – a branch of the Tyumen Scientific Center of the Siberian Branch of the Russian Academy of Sciences in 2015–2022 on plants of 12 late-ripening (single-cut) samples of red clover of the 1st year of use. Weather conditions in most years were warm with sufficient precipitation, dry conditions were observed only in 2021; the hydrothermal coefficient (HTC) of Selyaninov was 0.47–2.55. The date of resumption of vegetation was noted in the second decade of April, the cutting of green mass was carried out in the second decade of July. In 2015–2022 harvesting of green mass from varieties of red clover ranged from 17.9 to 62.5 t/ha, with a dry matter content in it from 20.4 to 37.1 % and a difference between the values by years from 0.8 to 13.3 %. There was a relationship between the value of the HTC and the ratio of fodder products in freshly harvested (green mass) and dry form (hay). With HTC values >2, the collection of green mass was 4.2–4.6 times higher than the yield of hay with HTC < 2, 3.0–3.4 times. The dry matter content of green mass under conditions of excessive moisture (HTC = 2.4–2.55) decreesed – 21.9–23.5 %, with a lack of moisture (HTC = 0.47–1.25) increased – 31.2–34.7 %, which was confirmed by a significant negative correlation (r = -0.753–0.965) between the dry matter content and the HTC for the season (April – July) for all varieties. The sum of active temperatures in April-May (r = 0.746–0.846 for 5 varieties) could also contribute to the increase in the dry matter content in the green mass, which indicated the importance of warmth during the spring regrowth.

Strain Release in Hydrogen Atom Transfer from 1,4-Disubstituted Cyclohexanes to the Cumyloxy Radical

A kinetic, product and computational study on the reactions of the cumyloxyl radical (CumO•) with 1,4-dimethyl- and 1,4-diphenylcyclohexanes is reported. The rate constants for hydrogen atom transfer (HAT) from the C-H bonds of these substrates to CumO•, together with the corresponding oxygenation product distributions reveal the role of strain release on reaction site-selectivity. Transition structures and activation barriers obtained by DFT calculations are in excellent agreement with the experimental results. Tertiary/secondary ratios of oxygenation products of 0.6, 1.0 and 3.3 were observed, for trans-1,4-dimethyl-, cis-1,4-dimethyl- and trans-1,4-diphenylcyclohexane, respectively. With cis-1,4-diphenylcyclohexane, exclusive formation of the diastereomeric tertiary alcohol products was observed. Within the two diastereomeric couples, the tertiary equatorial C-H bond in the cis- isomer is ∼6 and 27 times more reactive, respectively, than the tertiary axial ones, a behavior that reflects the release of 1,3-diaxial strain in the HAT transition state. The tertiary axial C-H bonds of the four substrates show remarkably similar reactivities in spite of the much greater stabilization of the benzyl radicals resulting from HAT from the 1,4-diphenylcyclohexanes. The lack of benzylic acceleration is discussed in the framework of Bernasconi’s “principle of non-perfect synchronization”.

A climatically significant abiotic mechanism driving carbon loss and nitrogen limitation in peat bogs

Sphagnum-dominated bogs are climatically impactful systems that exhibit two puzzling characteristics: CO2:CH4 ratios are greater than those predicted by electron balance models and C decomposition rates are enigmatically slow. We hypothesized that Maillard reactions partially explain both phenomena by increasing apparent CO2 production via eliminative decarboxylation and sequestering bioavailable nitrogen (N). We tested this hypothesis using incubations of sterilized Maillard reactants, and live and sterilized bog peat. Consistent with our hypotheses, CO2 production in the sterilized peat was equivalent to 8–13% of CO2 production in unsterilized peat, and the increased formation of aromatic N compounds decreased N-availability. Numerous sterility assessments rule out biological contamination or extracellular enzyme activity as significant sources of this CO2. These findings suggest a need for a reevaluation of the fixed CO2:CH4 production ratios commonly used in wetland biogeochemical models, which could be improved by incorporating abiotic sources of CO2 production and N sequestration.

Evaluation of Individual Cardiovascular Risk in Pre-Dialysis CKD Patients by Using the Ratio of Calcium-Phosphorus Product to Estimated Glomerular Filtration Rate (Ca × P/eGFR).

Chronic kidney disease (CKD) patients have an increased risk of cardiovascular disease (CVD), necessitating effective risk assessment methods. This study evaluates the calcium-phosphorus product (Ca × P) to estimated glomerular filtration rate (Ca × P/eGFR) ratio as a potential biomarker for predicting CV risk in pre-dialysis CKD patients. Eighty-four CKD patients in stages G1-G4, according to the KDIGO criteria, were classified into CVD (n = 43) and non-CVD (n = 41) groups. Biochemical parameters, including serum creatinine (SCr), blood urea nitrogen (BUN), calcium (Ca), inorganic phosphate (Pi), parathyroid hormone (PTH), alkaline phosphatase (ALP), Ca × P, eGFR, and the Ca × P/eGFR ratio, were measured and calculated. Statistical analyses were performed to identify predictors of CV risk and evaluate the diagnostic reliability of the Ca × P/eGFR ratio for predicting the risk. Significant differences were observed in SCr, BUN, eGFR (p < 0.001), and the Ca × P/eGFR ratio (p = 0.007) between the groups. Regression analysis indicated the Ca × P/eGFR ratio as a significant CVD risk predictor (p = 0.012, OR = 1.206, 95% CI: 1.042-1.395). Receiver Operating Characteristic (ROC) curve analysis revealed an AUC of 0.751 (p < 0.001, 95% CI: 0.645-0.857), with a sensitivity and specificity of the method of 74.4% and 70.7%, respectively. Significant correlations were found between the Ca × P/eGFR ratio and SCr, BUN, UA, Ca, Pi, PTH, and ALP. The Ca × P/eGFR ratio may serve as a significant predictor of CVD risk in pre-dialysis CKD patients, suggesting that its integration into routine evaluations could enhance CV risk stratification and management.

Feasibility and inter-reporter variability of submaximal outcomes derived from cardiopulmonary exercise testing in people with advanced cystic fibrosis lung disease

BackgroundCardiopulmonary exercise testing (CPET) provides prognostic information in people with advanced cystic fibrosis lung disease (pwACFLD). This project aimed to ascertain feasibility and inter-reporter variability in the identification of submaximal CPET outcomes for pwACFLD as potential predictors of prognosis where no peak exercise data are available.MethodsWe utilised data from an international retrospective multicentre study involving pwACFLD, for whom raw CPET data were available. Two experienced operators independently reviewed and analysed CPET tests with a focus on three pre-defined measures: oxygen uptake (V̇O2) at the anaerobic threshold (AT), the breathing reserve index at the AT (BRIAT), and the slope of the minute ventilation to carbon dioxide production ratio (V̇E/V̇CO2-slope). We calculated intra-class correlation coefficients (ICC) with their 95% confidence intervals (CI), and limits of agreement using the Bland-Altman method.ResultsThe original cohort included 174 pwACFLD. Among those, raw CPET data were available for 101 individuals, of which 89 tests were of sufficient technical quality for submaximal analysis. In 72 out of 89 technically-acceptable tests (81%), the AT could be confidently identified by both operators. Furthermore, ICCs indicated good-to-excellent inter-reporter agreement for V̇O2at the AT [ICC (95% CI) 0.79 (0.62 to 0.88)], the V̇E/V̇CO2-slope [0.95, 0.93 to 0.97)], and BRIAT [0.76, 0.63 to 0.85].ConclusionsSubmaximal CPET data can be reliably obtained in most pwACFLD by trained CPET operators. Future studies may ascertain the prognostic value of submaximal CPET outcomes in pwACFLD.

13C-metabolic flux analysis of respiratory chain disrupted strain ΔndhF1 of Synechocystis sp. PCC 6803.

Cyanobacteria are advantageous hosts for industrial applications toward achieving sustainable society due to their unique and superior properties such as atmospheric CO2 fixation via photosynthesis. However, cyanobacterial productivities tend to be weak compared to heterotrophic microbes. To enhance them, it is necessary to understand the fundamental metabolic mechanisms unique to cyanobacteria. In cyanobacteria, NADPH and ATP regenerated by linear and cyclic electron transfers using light energy are consumed by CO2 fixation in a central metabolic pathway. The previous study demonstrated that the strain deleted a part of respiratory chain complex (ΔndhF1) perturbed NADPH levels and photosynthetic activity in Synechocystis sp. PCC 6803. It is expected that disruption of ndhF1 would result in a decrease in the function of cyclic electron transfer, which controls the ATP/NAD(P)H production ratio properly. In this study, we evaluated the effects of ndhF1 deletion on central metabolism and photosynthesis by 13C-metabolic flux analysis. As results of culturing the control and ΔndhF1 strains in a medium containing [1,2-13C] glucose and estimating the flux distribution, CO2 fixation rate by RuBisCO was decreased to be less than half in the ΔndhF1 strain. In addition, the regeneration rate of NAD(P)H and ATP by the photosystem, which can be estimated from the flux distribution, also decreased to be less than half in the ΔndhF1 strain, whereas no significant difference was observed in ATP/NAD(P)H production ratio between the control and the ΔndhF1 strains. Our result suggests that the ratio of utilization of cyclic electron transfer is not reduced in the ΔndhF1 strain unexpectedly.

Toxicological problems of tattoo removal: characterization of femtosecond laser-induced fragments of Pigment Green 7 and Green Concentrate tattoo ink.

Femtosecond lasers represent a novel tool for tattoo removal as sources that can be operated at high power, potentially leading to different removal pathways and products. Consequently, the potential toxicity of its application also needs to be evaluated. In this framework, we present a comparative study of Ti:Sapphire femtosecond laser irradiation, as a function of laser power and exposure time, on water dispersions of Pigment Green 7 (PG7) and the green tattoo ink Green Concentrate (GC), which contains PG7 as its coloring agent. The treated samples were subsequently analyzed via UV‒Vis spectroscopy, gas chromatography‒mass spectrometry (GC‒MS), SEM imaging and associated statistical analysis. We found that, on average, the discoloration efficacy of femtosecond laser treatment was comparable to that of nanosecond lasers as were the decomposition products. In fact, two primary types of fragments are produced, both of which are potentially harmful, resulting either from the decomposition of chlorinated phthalocyanine (i.e., PG7) or from the active chlorination of naphthalene impurities. However, the outcomes for the PG7 and GC treatments differed significantly from each other from several points of view. The spectral intensity patterns of GC and PG7 were distinct, depending on the treatment conditions, and showed linearity with power only in the case of GC. Additionally, the relative ratios of the fragment products differed significantly, with the production rate showing a linear dependence on power only in the case of GC and no discernible trend for PG7. Shape and size distribution of the generated particles were highly dependent on the type of sample. Femtosecond laser irradiation of GCs primarily produces nanoparticles with a homogeneous size distribution, which are typically considered nontoxic. Large aggregates also formed, exhibiting a regular shape. In contrast, PG7 yielded rods and needles with aspect ratios similar to those of toxic fibers.

Cereal-legume intercropping enhances the quality of feedstock for lignocellulosic bioethanol production by reducing the carbon: nitrogen ratio

Bioethanol production from cereal straw is a sustainable alternative to meet the current energy demand, but its low nitrogen (N) content and high carbon to nitrogen (C/N) ratio are problematic during bioethanol processing. Intercropping cereals with legumes may increase the N content and reduce the C/N ratio in the harvested straw biomass. In order to investigate the combined production of food, feed, and suitable feedstock (low C/N ratio) for lignocellulosic bioethanol production, a field experiment on cereal-legume intercropping was carried out in southern Sweden. In the experiment, autumn-sown cereals (wheat, triticale, and rye) were grown as monocrops with two different N fertilization levels (60 and 120 kg N ha−1) or intercropped with autumn-sown or spring-sown (undersown) clover-grass, autumn-sown or spring-sown (undersown) alfalfa, or autumn-sown faba bean. Total grain dry matter yield, cereal grain protein content, straw dry matter yield, and straw biomass C/N ratio were estimated. The results showed that the intercrops produced more straw biomass and had a lower C/N ratio, but produced less grain, than cereal monocrops. Among the cereals, rye showed significantly higher grain and straw yields, but lower grain protein content, in all treatments. Among the intercrop treatments, cereal with spring-sown clover-grass produced higher grain and straw yields and had a significantly lower C/N ratio (38:1) than the other treatments. Thus, cereal with spring-sown (undersown) clover-grass is a promising cropping system for lignocellulosic bioethanol production.

Allzyme® Spectrum supplementation improves apparent ileal phosphorus digestibility and retention in older laying hens

Abstract Phosphorus (P) is required by laying hens for various biological functions, and it is usually provided in excess, in a readily digestible inorganic form in diet formulations. By adding enzymes to diets, the availability of phytate-bound P can be increased, allowing for the reduced inclusion of inorganic P in the diet formulation. The following study was conducted to examine the effect of a natural enzyme complex that contains phytase and xylanase on P digestibility in laying hens. Novogen Brown Classic layers (n=314, 95 weeks of age, approximately 14 weeks into second lay) were fed one of two diets; either a basal control diet or a the basal control diet plus a natural mixed-enzyme product (Allzyme® Spectrum; ASC, Alltech Inc, KY, USA) containing phytase (1000 SPU/g) and xylanase (7,500 EPU/g). The experimental diets were provided for 15 days, and excreta was collected from each pen at day 13–15 of the trial to determine total tract retention and apparent ileal digestibility of P and gross energy. At the end of the trial, birds were euthanised and ileal contents were collected. Productivity parameters, including egg production and feed conversion ratio, were recorded over the course of the study. The amount of P in the excreta from birds in the control group was significantly higher than the ASC enzyme-supplemented group. Both P retention, its ileal digestibility and gross energy digestion (ileum and total tract) were significantly higher in the ASC enzyme-supplemented birds. This study showed that the ASC enzyme supplement can improve the total retention and ileal digestibility of P and gross energy in older layers.

Comet 289P/Blanpain: Near-perihelion Activity and the Phoenicids

Abstract We present NEOWISE observations of Jupiter family comet 289P/Blanpain, the parent body of the Phoenicid meteoroid stream. Near-infrared images at 3.4 μm (W1) and 4.6 μm (W2) were obtained near perihelion on two occasions: UT 2019 October 30 (inbound, heliocentric distance R h = 1.20 au) and UT 2020 January 11–12 (outbound, R h = 1.01 au). To assess faint activity, we establish constraints on dust production driven by the limited sublimating area of water ice, based on studies of the 1956 Phoenicids. The ejected dust masses are M d = 4100 ± 200 kg (inbound) and 1700 ± 200 kg (outbound), respectively. The dust production rates are Q dust = 0.01–0.02 kg s−1, corresponding to a dust-to-gas production ratio of 2 ≤ f dg ≤ 6. The resulting fractional active area, f A = 3.8 ± 1.9 × 10−5, is the smallest yet reported. The absence of 4.6 μm (W2) excess suggests that 289P/Blanpain contains negligible amounts of CO2 and CO. Time-resolved analysis of the weighted mean of the W1 and W2 magnitudes finds a distinctive peak amplitude in the light curve having a rotational period P rot = 8.8536 ± 0.3860 hr, however, further verification is needed. The perihelion-normalized nongravitational acceleration, α NG ′ = 3.1 × 10−6, is approximately an order of magnitude smaller than the trend observed for well-studied comets, consistent with weak outgassing. Current dust production from 289P/Blanpain, regardless of plausible assumptions for the particle size and distribution, is an order of magnitude too small to produce the Phoenicid stream within its ~300 yr dynamical lifetime. This suggests another mass supply, probably in 1743–1819, from rapid rotational destruction of a subkilometer precursor body, resulting in fragments equaling the mass of an object with radius ~ 100 m.

Optimization of Compost and Peat Mixture Ratios for Production of Pepper Seedlings.

Substituting peat moss with compost derived from organic waste in plant nurseries presents a promising solution for reducing environmental impact, improving waste management, and enhancing soil health while promoting sustainable agricultural practices. However, selecting the appropriate proportions of both materials is crucial for each plant species. This study investigates the effects of different ratios of compost and peat mixtures on the growth and development of pepper seedlings. The compost mixtures used in the study included the following combinations: sewage sludge with sawdust (A), sewage sludge with sawdust and biodegradable garden/park waste (B), and biodegradable garden/park waste with sawdust (C). The final substrates used for seedling production were composed of composts (A, B, C) and peat (O) as a structural additive, mixed in different proportions by mass: I-O 25%, II-O 50%, and III-O 75%. Seedlings grown in these substrates were assessed using biometric and physiological measurements. Nematode species present in substrates were identified by metabarcoding analysis. The results revealed that substrate productivity depended not only on nutrient content but also on structural properties, which were significantly influenced by the peat proportion. Among the tested compost mixtures, variant A I emerged as the most effective substrate, promoting optimal seedling growth. Molecular nematode analysis revealed significant nematode contamination in substrates with higher peat proportions (C II and C III), including Meloidogyne sp. Lichtenburg (26%), Meloidogyne hispanica (5%), Meloidogyne sp. Mi_c1 (3%), Meloidogyne ethiopica (2%), and Meloidogyne thailandica (1%). The findings underscore the critical importance of achieving an optimal balance between nutrient content and structural properties in substrates to support the healthy growth and development of pepper seedlings. To further enhance crop performance and reduce the risk of pest-related damage, it is essential to prioritize the improvement of substrate selection strategies. Monitoring for nematode contamination is crucial to prevent potential compromises in seedling quality and overall productivity.

Biogas and Organic Manure Production from Anerobic Digestion of Rubber Plant Effluent, Gliricidia Leaves, and Inoculum: Energy Sustainability and Socio-Economic Development of Mauritania

This study analyzed the anaerobic co-digestion of inoculum (I), rubber plant effluent (RPE) and Gliricidia leaves slurry (GLS) at different mixing ratios for the simultaneous production of methane and organic fertilizer. The results were analyzed for volatile fatty acids, pH, C/N ratio, and methane production. The organic quality of the substrate mixture before and after anaerobic digestion was analyzed for total organic carbon, total nitrogen, potassium, and phosphorus contents. This study concluded that the inoculum, rubber plant effluent (RPE), and Gliricidia leaves slurry (GLS) mixed at the ratio of 10:2:2 showed higher methane production than other experiments conducted at different mixing ratios. The nitrogen, potassium, and phosphorus contents of the substrates were increased after anaerobic digestion. However, the organic carbon content in the substrate decreased in all experiments. This research recommends the planting of rubber trees and Gliricidia maculata to promote energy sustainability and the socio-economic development of Mauritania.

Climate change and its effects on the marine food web with a concentration on the pelagic fishery in the northern Arabian Sea

The northern Arabian Sea, a vital ecosystem that sustains a significant population through its fisheries is increasingly threatened by climate change, overharvest, and coastal pollution. To evaluate the combined effects of these pressures on fishery health, microplankton, fish bycatch, and coastal environment data were examined between 2019 and 2023 from key hotspots. Using the time-cumulated indicator (TCI) and efficiency cumulated indicator (ECI) approaches, we aimed to determine broader patterns of energy flow in the ecosystem. The findings revealed a delicate equilibrium in the ecosystem. Although average temperatures remained stable, variations in rainfall patterns suggested potential changes in salinity and dissolved oxygen levels, signaling subtle climate change influences. Biological indicators highlighted dynamic shifts: species diversity fluctuated, suggesting community restructuring, while increased evenness implied potential ecological stabilization. The production and biomass (P/B) ratio was higher in 2019, reflecting faster biomass production compared to the slower rate observed in 2023. This instability may be attributed to environmental changes, altered species composition, and a steady increase in fishing pressure. Notably, consistent fish catches amidst relatively stable species diversity suggest complex population dynamics. In terms of energy flow and transformation, a significant rise in TCI, suggests accelerated energy transfer, likely driven by a decline in predator population. Additionally, the instability in Residence Time (RT) underscores intricate food web interactions. Our findings highlight the delicate equilibrium of the northern Arabian Sea, as revealed by the overall data and assessment. Understanding these intricate dynamics is crucial for developing effective conservation strategies and promoting sustainable fishing practices.