Length Growth Rate Research Articles

Microcirculatory parameters as risk factors for predicting progression of posterior staphyloma in highly myopic eyes: a case–control study

BackgroundTo assess the rate of macular blood flow decreasing in adults with and without posterior staphyloma (PS) using optical coherence tomography angiography (OCTA) and to identify risk factors associated with PS progression.MethodsThis longitudinal case-control study enrolled 122 eyes of 122 patients—64 patients with PS (PS group) and 58 patients without PS (NPS group). Participants underwent OCTA and clinical examinations at least twice, and those followed for at least one year were included in the analysis. Logistic regression analysis and machine learning were applied to explore the risk factors for PS and its progression.ResultsPatients in the PS group exhibited faster growth rates of spherical equivalent refraction (SER), axial length (AL), curvature index (CI), and posterior scleral height (PSH) as well as higher loss rates of choriocapillaris perfusion area (CCPA), choroid perfusion area (CPA) and choroidal vascularity index (CVI) compared to the NPS group (all P < 0.05). The baseline SER (B = − 1.291, OR = 0.275, P = 0.008), baseline subfoveal scleral thickness (B = − 1.621, OR = 0.198, P = 0.046), baseline PSH (B = 2.959, OR = 19.282, P = 0.001) and foveal CVI changes per year (B = − 2.776, OR = 0.062, P < 0.001) were the risk factors for PS. Baseline AL (B = 0.561, OR = 1.752, P = 0.033), parafoveal choroidal thickness changes per year (B = − 0.094, OR = 0.910, P = 0.032), foveal retinal vascular density changes per year (B = 0.104, OR = 1.110, P = 0.013) and foveal CCPA changes per year (B = − 0.214, OR = 0.807, P = 0.038) were the risk factors for the PS progression.ConclusionsDuring the progression of myopia in adults, changes in the morphology of the eye's posterior pole are not limited to axial lengthening alone; there also will be a phase of compensatory lateral expansion. Baseline AL and changes in the microcirculation can be utilized to predict the progression of PS.

Growth Performance of Galaxy Rasbora Danio margaritatus Larvae Maintained at Different Stocking Densities

The issue of low survival rates and high mortality of larvae is commonly encountered during the rearing process. The success of larval rearing is significantly influenced by optimal stocking density, good water quality, and controlled feed management, all of which affect the growth and survival of the larvae. The aim of this applied research is to implement rearing techniques with different stocking densities and assess their effects on the growth and survival of galaxy rasbora (Danio margaritatus) larvae. This study employed a Completely Randomized Design (CRD) with four different stocking density treatments: 1 fish L⁻¹ for treatments KT1 and PT1, 2 fish L⁻¹ for treatment PT2, and 3 fish L⁻¹ for treatment PT3, each with three repetitions. The results showed that different stocking densities had a significant effect on the growth and survival of the larvae. The highest survival rate was observed in treatment PT2, with 96% survival. The control treatment (KT1), which used a semi-intensive system, achieved the highest absolute length growth of 6.87 mm and the highest daily length growth rate of 32.73% day⁻¹. The stocking density of 2 fish L⁻¹ in treatment PT2 demonstrated optimal results in terms of survival and growth.

Ocean Acidification and Sea Temperature Rise Affect the Queen Scallop Aequipecten opercularis (Linnaeus, 1758) in Captivity

Climate change poses risks to bivalves; thus, searching for resilient alternative species is crucial for sustainable fisheries. This study examines the impact of reduced pH and elevated temperature and their combined effects on the queen scallop Aequipecten opercularis in captivity. The results indicated that a low pH reduced its growth rates in both weight (0.03 ± 0.05 g/day) and length (0.06 ± 0.16 mm/day), as well as leading to decreases in meat yield (20.75 ± 2.75%) and the condition index (44.21 ± 7.19%). Conversely, elevated temperature resulted in an increased growth in length (0.07 ± 0.23 g/day), meat yield (21.57 ± 4.82%), and condition index (45.42 ± 7.35%). Combined stressors initially promoted growth but ultimately produced unsustainable outcomes, resulting in a reduced meat yield (18.28 ± 2.60%) and condition index (38.92 ± 8.23%), along with a peak mortality rate of 27%. These findings indicate that while A. opercularis can withstand individual stressors, exposure to simultaneous stressors may compromise its long-term viability in aquaculture systems.

Numerical study of turbulent eddy self-interaction in tokamaks with low magnetic shear. Part I: Linear simulations

Abstract This study examines the impact of low and zero magnetic shear, along with rational values of safety factor, on linear mode behavior in tokamak plasmas. We focus on how magnetic field line topology and parallel domain length influence linear mode structures and growth rates as magnetic shear decreases. Our results&amp;#xD;show that as magnetic shear is reduced to low values, linear modes can transition between different branches, significantly affecting their characteristics. At zero magnetic shear, accurate modeling requires precisely capturing magnetic topology, as small deviations near rational surfaces can greatly impact growth rates. These findings are extended to nonlinear simulations in a companion paper (Volčokas, 2024), revealing that long turbulent eddies and magnetic field line topology play a crucial role in turbulence self-interaction and plasma transport.

Bone turnover markers, and growth and bone parameters in infants participating a Vitamin D intervention study.

Amino-terminal propeptide of type 1 procollagen (P1NP) and carboxy-terminal crosslinked telopeptide of type 1 collagen (CTX-I) are markers of bone metabolism. We examined the effect of vitamin D3 supplementation on these markers and their relationship with growth and bone parameters in 12-month-old infants. In a randomized, double-blinded, Vitamin D intervention in infants (VIDI) study, 987 infants received daily vitamin D3 supplementation of 10 μg (Group-10) or 30 μg (Group-30) from age 2 weeks to 24 months. We conducted a secondary analysis of the original VIDI trial. At 12 months of age, P1NP (n=812) and CTX-I (n=786) concentrations were analyzed, and anthropometrics and total bone mineral content, volumetric bone mineral density, cross-sectional area and polar moment of inertia of tibia were measured by peripheral quantitative computed tomography. Growth rate in weight and length was calculated from birth to 12 months. Vitamin D dose did not influence mean (SD) levels of CTX-I (group-10: 0.90 (0.31); group-30: 0.89 (0.31) (p<0.53). Mean difference of P1NP (CI 95%) comparing group-10 with group-30 was 35 (-103, 33) ng/ml (p=0.31) in boys and -63 (-4, 130) ng/ml (p=0.064) in girls, respectively. In group-10 girls had higher mean (SD) value of P1NP (1509 (362) ng/mL) than boys (1407 (297) ng/mL) (p=0.003); no sex differences were observed in group-30 (girls: 1446 (359); boys: 1442 (359), p=0.91) or CTX-I. P1NP associated positively with growth rate in length (B (CI 95%] 0.0003 (0.0001, 0.001), p=0.022) in the whole cohort, but not in subgroups divided by intervention group nor sex, adjusted for birth size and parental heights and corrected for multiple testing. P1NP associated positively with growth rate in weight (0.01 (0.0003, 0.01), p<0.001). An inverse association was observed between CTX-I and length (cm) in the whole cohort (-0.90 (-1.40, -0.40), p=0.005) and in group-30 (-1.05 (-1.72, -0.39), p=0.011). Further, CTX-I associated negatively with weight (SDS) in the whole cohort (-0.33 (-0.55, -0.12), p=0.015) and growth rate in weight (-0.43 (-0.66, -0.20), p=0.005), persisting in group-30 and in boys, but not in group-10 or in girls. Neither marker was associated with bone parameters.The observed sex difference in P1NP might suggest that higher vitamin D dose resulted in a small decrease in bone collagen matrix formation in girls but not in boys. P1NP and CTX-I associate with growth and body size, but not with bone mineralization in infancy.

Thermal Stability and Thermal Fatigue Resistance Improvement of New High Toughness 5% Cr Hot Working Die Steel

This work developed a new high toughness 5% Cr martensitic hot working die steel (GYDCK-20), which exhibits better thermal stability and thermal fatigue resistance than AISI H13 steel. The concrete study involves: conducting on the evolution of microstructures and mechanical properties of two steels during the 60-hour holding process at 600°C, as well as the thermal fatigue behavior under the cyclic heating-water quenching conditions. The experimental results showed that in the case of ensuring the same initial hardness of two steels (43-43.5 HRC), GYDCK-20 emerged better thermal stability and superior toughness after 60-hour holding process at 600°C. After thermal cycling was increased from 1000 to 2000 times, the average crack length growth rate of GYDCK-20 was 31.8% lower than that of H13 and the maximum crack width growth rate was 35.1% lower than that of H13. It was found that thermal fatigue cracking was dominated by transgranular propagation at lower cycle numbers, while more inclined to propagate along the grain boundaries at higher cycle numbers. The higher toughness of GYDCK-20 steel promotes the dispersion of thermal stress, thereby enhancing the thermal fatigue resistance. It is mainly attributed to the lower V content of GYDCK-20 steel, which reduces the density of large-sized MC primary carbides. On the other hand, the lower Si content promotes the dissolution of cementite particles, and the secondary carbides precipitate in a smaller and uniformly distributed form, which hinders the propagation of thermal fatigue cracks, while also delays the coarsening of the fatigue-adverse phase M23C6 carbides.

Nursery production, acclimatization, and orchard transplantation of Argania spinosa: Evaluating the impact of costs and plant age

The depletion of the argan area over time underscores the importance of enhancing the quality of argan seedlings to support regeneration. Key factors such as seedling age and nursery techniques including shade, substrate, and container play a crucial role in improving seedling quality and ensuring successful transplantation. Our study assessed the impact of seedling age, shading, substrate composition, and container volume on argan seedling production during the nursery phase and their influence in the transplantation phase. The findings revealed 40% shade covering in 12- and 18-month-old seedlings exhibited the most growth potential, while unshaded compartments were suitable for 6-month-old seedlings. Substrates S1, S3 and S6 respectively, resulted in the highest quality seedlings overall, with S1 being the most effective for 6-month-old seedlings, and S3 and S6 showing more impact for 12- and 18-month-old seedlings. Furthermore, the use of larger containers contributed to the production of high-quality seedlings. Field results showed lower mortality rates across different seedling ages (3.1% to 9.3%) and revealed no significant difference among the combinations, except for seedlings produced under 40% shade, where the S3C3 combination followed by S1C2 in the 6-month nursery production period demonstrated the highest relative growth rate in shoot length. The relative growth rate in diameter reported its highest value in the S1C2 combination of 18-month and 6-month-old seedlings. A cost benefit analysis was carried out, which revealed that the cost-effective combination was S1C2, followed by S3C3 for 6-month-old nursery age under the 40% compartment.

Microplastic-Enhanced Cadmium Toxicity: A Growing Threat to the Sea Grape, Caulerpa lentillifera.

The escalating impact of human activities has led to the accumulation of microplastics (MPs) and heavy metals in marine environments, posing serious threats to marine ecosystems. As essential components of oceanic ecosystems, large seaweeds such as Caulerpa lentillifera play a crucial role in maintaining ecological balance. This study investigated the effects of MPs and cadmium (Cd) on the growth, physiology, biochemistry, and Cd accumulation in C. lentillifera while elucidating the underlying molecular regulatory mechanisms. The results demonstrated that exposure to MPs alone significantly promoted the growth. In contrast, exposure to Cd either alone or in combination with MPs significantly suppressed growth by reducing stem and stolon length, bud count, weight gain, and specific growth rates. Combined exposure to MPs and Cd exhibited the most pronounced inhibitory effect on growth. MPs had negligible impact while Cd exposure either alone or combined with MPs impaired antioxidant defenses and exacerbated oxidative damage; with combined exposure being the most detrimental. Analysis of Cd content revealed that MPs significantly increased Cd accumulation in algae intensifying its toxic effects. Gene expression analysis revealed that Cd exposure down-regulated key genes involved in photosynthesis, impairing both photosynthetic efficiency and energy conversion. The combined exposure of MPs and Cd further exacerbated these effects. In contrast, MPs alone activated the ribosome pathway, supporting ribosomal stability and protein synthesis. Additionally, both Cd exposure alone or in combination with MPs significantly reduced chlorophyll B and soluble sugar content, negatively impacting photosynthesis and nutrient accumulation. In summary, low concentrations of MPs promoted C. lentillifera growth, but the presence of Cd hindered it by disrupting photosynthesis and antioxidant mechanisms. Furthermore, the coexistence of MPs intensified the toxic effects of Cd. These findings enhance our understanding of how both MPs and Cd impact large seaweed ecosystems and provide crucial insights for assessing their ecological risks.

Profiling growth performance, insulin-like growth factors (IGFs), and IGF-binding proteins (IGFBPs) in rainbow trout lacking IGFBP-2b.

Insulin-like growth factor binding proteins (IGFBP) regulate insulin-like growth factor (IGF) signaling, but IGFBP-specific functions are not well characterized in fishes. A line of rainbow trout (Oncorhynchus mykiss) lacking a functional IGFBP-2b was produced using gene editing and subsequent breeding to an F2 generation. This loss-of-function model (2bKO) was subjected to either continuous feeding or feed deprivation (3 wk) followed by refeeding (1 wk). During continuous feeding, the 2bKO line displayed faster specific growth rate for both body weight and fork length, higher feed intake, and reduced feed conversion ratio compared to a wild type (WT) line. However, loss of IGFBP-2b did not affect the feed deprivation or refeeding response in terms of weight loss or weight gain, respectively. Several components of the IGF/IGFBP system were affected by loss of IGFBP2b. Total serum IGF-1 in the 2bKO line was reduced to 0.5 - 0.8-fold of the WT line although the concentration of free serum IGF-1 was not affected. Gene expression differences include reduced abundance of igfbp1a1, igfbp1b2, igfbp5b2, and igfbp6b1 transcripts, and elevated igf2 and igfbp6b2 transcripts in liver of the 2bKO line. Collectively, these findings suggest that although IGFBP-2b is a carrier of circulating IGF-1 in salmonids, the presence of IGFBP-2a and compensatory responses of other IGF/IGFBP system components support an anabolic response that improved growth performance in the loss-of-function model.

Age and growth rate estimated by skeletochronology in loggerhead sea turtles from French Mediterranean waters

Abstract Skeletochronology was used to determine the ages of 30 loggerhead sea turtles (Caretta caretta) found in French Mediterranean waters. Histological sections were performed with 30 humeri collected on stranded C. caretta on the coast of Provence and the Gulf of Lion. Lines of arrested growth (LAGs) were used to evaluate age, considering only one period of arrested growth per year. Two successive LAGs delimit an interval that is proportional to the individual’s body growth. In a first step, we created a skeletogram for each individual that identified its LAGs. Secondly, we measured the areas delineating successive intervals to determine individual growth patterns over the years. Two methods were used to deduce sea turtle age from histological sections: the correction factor (CF) method and the growth rate (GR) method, the latter using Von Bertalanffy growth function. Age estimations varied from 4.3 to 24.7 years (mean ± SD = 10.1 ± 4.8) with the CF method and from 6.2 to 25.6 years (mean ± SD = 12.2 ± 5.2) with the GR method, with no significant difference between the methods. The study sample was thus mostly composed of juveniles, which is also the most frequent life stage observed in the study area. The annual curved carapace length growth rate calculated with every LAG interval varied from 1.0 to 6.9 cm/year (mean ± SD = 3.5 ± 1.4, ). High variability in interindividual growth rates were observed, which is of interest in understanding the complex lifecycle of these long-lived marine reptiles.

Pertumbuhan Udang Galah (Macrobrachium Rosenbergii) yang Diberi Perlakuan Vegetable Floating Raft (VFR)

Galah shrimp is one type of freshwater shrimp that has great potential for cultivation. One of the obstacles to the growth of king prawns is water quality. This study was conducted to determine the effect of the installation of Vegetable Floating Raft (VFR) on the growth of king prawns (Macrobrachium rosenbergii). This study was conducted using the t-test method, with control and Vegetable Floating Raft treatments. The results showed that the growth pattern of weight and length of king prawns in each treatment was relatively the same. However, the daily weight growth rate of king prawns in the control treatment was greater at 3.36%, compared to the treatment of Vegetable floating raft at 1.26%, while the daily length growth rate of king prawns in the control treatment was 0.86%. The daily length growth rate in the Vegetable floating raft treatment was smaller at 0.61%. During the study the value of the degree of survival of the control treatment was 95%, while in the treatment of Vegetable floating raft the percentage of the degree of survival of king prawns was 62%. Based on the results of visual observations seen the rest of the feed and the rest of the skin during molting. It is suspected that shrimp are stressed due to changes in water quality characterized by increased ammonia levels in the last maintenance week caused by the death of kale plants in the maintenance medium.

Phylogenetic, growth performance and protein growth hormone of snakehead fish (Channa striata) from wild stock in Sumatra, Indonesia

Abstract Watershed isolation may influence morphological, genetic variations, and protein expression of snakehead fish (Channa striata). This research seeks to identify snakehead diversity from isolated Inland waters in Sumatra, i.e., Kampar River (SK), Merang River (SM), Cala Lake (DC), and Lampam Floodplain (RL). Channa striata samples were collected from inland waters and cultivated in Aquaculture laboratory. Cytochrome b gene was used for genetic characterization. Growth protein was analyzed using Enzyme-Linked Immunosorbent Assays (ELISA). We collected DNA from four samples at each site. The growth performance of cultivated snakehead fish was also observed. Five hundred post-juvenile snakehead fish from four populations were cultivated for 45-days with five repetitions. Each population had 12 snakehead fish tested for GH protein. Data were statistically tested using ANOVA, maximum likelihood phylogenetic tree analysis, linear regression, and Pearson correlation. The results showed four clusters of snakehead fish in the phylogenetic tree. The DC population had the highest significant value of the daily length growth rate (7.5±0.2 %). The GH protein-growth relationship was low (0.014-0.083). The SM snakehead fish population had the highest concentration of GH protein (1.77±0.11 pg μl−1) and had distinct cyt.b gene clusters from other populations, making it a potential candidate for future aquaculture strain development.

Impact of dye treatment as management strategy on available light may favour a highly invasive alien aquatic plant

Attempts to control massive proliferations of invasive alien aquatic plants (IAAP) are often ineffective. A renewed interest for dye treatment is emerging aiming to control the submerged macrophyte Myriophyllum heterophyllum in France. We aimed to understand the effects of dye on this plant knowing about its adaptation to low light. In a 2 × 2 factorial design experiment, we assessed the effect of a dye mixture based on Brilliant Blue (E133) and Allura Red (E129) at high and low light intensities on light quantity and quality and how this might affect the plant’s performance by measuring morphological and physiological traits. A multivariate analysis identified three groups – high light (HL) plants, plants in high light with dye (HLD) or low light (LL), and low light with dye (LLD) plants. HL plants performed well but showed stress signs, with a reduced main shoot length, a higher leaf dry matter content (LDMC) and a lower nitrogen content (N), not observed in plants grown in HLD or LL. HLD and LL plants exhibited a comparable total length growth rate to those in HL, but had lower LDMC and higher N contents. LLD plants performed poorly with the lowest growth and signs of physiological stress. Dye-induced changes in light quality only marginally affected the absorbance range of chlorophyll b, which apparently did not affect photosynthesis. Commercially available dyes currently used to control nuisance aquatic plants thus seem to have little or no effect on submerged macrophytes. The presence of dye may exacerbate negative effects of very low light intensities on the plant’s growth. However, these very low intensities would only be reached during high-water levels or in winter, periods where the dye would rapidly be diluted. During summer, however, the application of dye may protect the plant from damaging light intensities and thus not be a good management strategy to control low light adapted invasive submerged macrophytes.

Comparative growth, survival, and feed conversion factor of the F1 generation of two new strains of tilapia Oreochromis niloticus produced by mass selection

Growth, survival, and use of feed of the F1 generation of two new strains of tilapia Oreochromis niloticus (GenBank Strain Y = OK078792 to OK078796 and Strain A = OK078797 to OK078807) produced by mass selection was compared with a known fast-growing commercial strain in Mexico (GenBank Strain Q = OR744820 to OR744838), during a grow-out phase of 165 days. Genetic variability including observed (Ho) and expected (He) heterozygosity, inbreeding coefficient (Fis), and paired comparisons of strain fixation index (Fst) of the three strains were also compared, and an additional analysis of molecular variance (AMOVA) was performed. Twelve hapas of 8.2 m3 (four for each strain) were stocked at a density of 25 org m−3 of 4.58 ± 0.67 g, which were fed with 45 to 25% crude protein feed under a dynamic feeding scheme of 8 to 3% live weight. Growth was estimated by growth rates in weight and length, and by the weight-specific growth rate (SGR). The use of feed was estimated by the total feed consumption rate and the feed conversion factor (FCF). Results indicate no significant differences (P > 0.05) in growth parameters of the three strains, except in SGR which was significantly higher in the control strain (Q) (2.75% day−1) as compared with strains Y and A (2.51 and 2.59% day−1 respectively). The average final weight and size of the fish were 314.6 ± 11.8 g and 25.5 ± 0.4 cm respectively. No significant differences (P > 0.05) were found in survival and feed utilisation among strains, with average values of 96.4% survival, feed consumption of 3.91 g day−1, and FCF of 2.08. Results of genetic diversity indicate that there were no significant differences (P > 0.05) in Ho and He of the three strains, with average values of 0.310 and 0.280 respectively. Fis values were negative and similar for the three strains, with a mean value of −0.109 which indicates no consanguinity in their populations. Finally, the paired comparisons of Fst were significantly different (P < 0.001), showing relatively low values but different from 0 (Y vs. A = 0.025, A vs. Q = 0.041 and Y vs. Q = 0.055), indicating slight but significant population differentiation between strains. In conclusion, the performance and genetic variability of the F1 generation of the two new strains suggest that valuable broodstock is now available for mass production of fry, with similar performance as to one of the best strains of tilapia in Mexico.

An A2 β-casein infant formula with high sn-2 palmitate and casein phosphopeptides supports adequate growth, improved stool consistency, and bone strength in healthy, term Chinese infants: a randomized, double-blind, controlled clinical trial.

The aim of this randomized, double-blind, controlled trial was to examine the effects of infant formula on the growth, stool consistency, and bone strength of infants (n = 120) over a period of 4 months. The investigational group was fed an A2 β-casein cow's milk infant formula containing casein phosphopeptides (CPP) and high sn-2 palmitate (54% of total palmitate at sn-2). The control group was fed a standard cow's milk formula without CPP and with low sn-2 palmitate (29% of total palmitate at sn-2). The third group was fed human milk (HM) (n = 60). All three groups had similar baseline characteristics, and maintained similar BMI, sleep habits, and growth rates in body weight and length throughout the study. However, compared to the control group, infants in the investigational and human milk groups had significantly: (i) greater body length at 90, 120, and 150 days of age; (ii) greater growth rate in head circumference from 30 to 60 days of age, with larger head circumference at 60 days of age; (iii) larger daily stool frequency at 60, 90, and 120 days of age; (iv) softer stool at 60, 90, and 120 days of age; (v) higher bone quality index and bone speed of sound at 150 days of age; (vi) fewer hours of crying at 60 and 90 days of age; (vii) less abdominal distention, burp, and flatus at 60, 90, and 120 days of age; and (viii) less constipation at 90 days of age. At other time points, no significant differences were observed between the three groups. No serious adverse events (AEs) related to the study products were reported, and significantly fewer infants in the investigational and HM groups experienced at least one AE compared to the control group. The study suggests that the A2 β-casein formula with high sn-2 palmitate and CPP supports adequate growth, is well tolerated, and may have beneficial effects on stool consistency, gastrointestinal comfort, crying duration, and bone density, comparable to HM. Clinical trial registration: https://clinicaltrials.gov/, NCT04749290.

Effects of yeast and willow extract in the diet on the survival and growth parameters of the crayfish (Cambarellus montezumae)

ABSTRACT The use of additives such as yeast or plant extracts in crayfish diets, even though are typically found in their natural habitats, has attracted recent attention due to the observed health, growth, and socio-economic benefits they offer. The presence of willow detritus in the stomach contents of free-living crayfish suggests its potential role in crayfish growth, even though it has not yet been demonstrated. This study aimed to evaluate the effect of yeast and willow extract as dietary additives on the growth of the crayfish Cambarellus montezumae. A total of 630 juvenile crayfish were collected, introduced into a recirculating aquaculture system, and randomly assigned to three treatment groups with three replicates each one (n = 70 per replicate): shrimp-balanced ration with yeast, shrimp-balanced ration with willow extract, and shrimp-balanced ration as the control. Throughout a 70-days period, the crayfish were weekly measured and weighed to assess various growth parameters and survival. Crayfish fed with the yeast ration showed improvements in weight, length, biomass, periodic absolute increase in weight and length, and relative growth rate in length compared with those in the willow and control groups. The incorporation of yeast into the ration demonstrates greater advantages to produce Cambarellus montezumae. The underlying mechanisms suggest efficient ration utilization and the potential for increased production which, has important implications for the aquaculture industry.

Harnessing Polar Interactions Tunes the Stability of Ultrathin Polymer Solution Films.

The stability of ultrathin (<100 nm) polymer films is essential in applications like protective coatings. On the contrary, their instability may actually be desirable for the emergence of self-assembled nanoscale patterns utilized in the fabrication of functional devices. Polymer solution films exhibit two distinct kinds of instabilities, viz., dewetting (long-wave) and decomposition (short-wave). Dewetting refers to the rupture of the continuous film to form isolated domains, while decomposition leads to phase separation within the polymer solution. The focus of this work is on leveraging polar interactions between the solute and solvent molecules to tune the stability of the film. A gradient dynamics-based thin film model is developed to investigate pattern formation in a thin polar polymer solution film. The Flory-Huggins theory is suitably modified by introducing a polar interaction parameter that depends upon the concentration of the polymer and the dipole moments of monomer (μ1) and solvent molecules (μ0). A linear stability analysis is performed to determine the characteristic length scale and growth rate of the instabilities. It is shown that the range of concentration space for the occurrence of the decomposition mode is directly affected by the Flory interaction parameter (χ0), μ0, and μ1, thereby serving as control parameters to tune the width of the concentration range. It is further shown that ignoring polar interactions may lead to incorrect predictions of the instability mode, including a complete loss of the decomposition mode. In addition, the long-wave dewetting length scale is found to decrease due to bulk dipolar interactions at higher polymer concentrations. Finally, numerical simulations are carried out to track the nonlinear evolution of the interface and concentration field for both the decomposition and dewetting modes of instability.

Growth optimalization of bileh fish seeds (Rasbora sp.) through different feeding frequencies

Bileh fish is a type of freshwater fish that is sought after by the people of Aceh because it has a delicious taste and is quite tasty. Bileh fish is a local fish species that has the potential to be developed as an aquaculture commodity and its population must be preserved from overfishing. The aim of this research was to determine the effect of different feeding frequencies on the growth of bileh fish fry (Rasbora sp.). This research used a non-factorial completely randomized design (CRD) method consisting of 4 treatments and 3 replications each, namely the frequency of feeding 1 time/day (P1), feeding 2 times/day (P2), feeding 3 times/day day (P3) and feeding 4 times/day (P4). The feed given is commercial feed PF 500 with 39% protein. The parameters observed included survival rate, length growth, weight growth, daily growth rate, feed efficiency and water quality. The results showed that different feeding frequencies had no significant effect on survival rate, absolute length and daily growth rate of bileh fish (Rasbora sp.). However, it has a real effect on weight growth and feed efficiency. The best feeding frequency to optimize the weight growth of bileh fish (Rasbora sp.) is in the P3 treatment with a frequency of 3 times/day.Keywords: Feed Efficiency; Feeding Frequency; Growth; Rasbora

Brandt's vole (Lasiopodomys brandtii) affects the dominant position of three gramineous species by altering defense traits and interspecific competition.

Rodents can cause considerable changes in plant community composition. However, relationships between shifts in species dominance and plant functional traits caused by rodents have seldom been investigated, especially for belowground functional traits. In this study, a set of enclosures was constructed to analyze the effects of 10 years of Brandt's voles' activities on the defense strategies and dominant position changes of three gramineous plants (Leymus chinensis, Stipa krylovii, and Cleistogenes squarrosa) in Inner Mongolia. Here, we measured the dominance, biomass, and fourteen functional traits of three plants. The effects of Brandt's voles on dominance, biomass, and functional traits were analyzed, and then we explored the effect of functional traits on plant dominance by using the structural equation model. Results showed that long-term feeding by Brandt's voles resulted in a significant decrease in the dominance of L. chinensis and S. krylovii, whereas C. squarrosa was positively affected. The belowground biomass of L. chinensis and S. krylovii was higher in the vole treatment, which showed that they were increasing their escape characteristics. The leaf thickness of L. chinensis and the leaf C:N ratio of S. krylovii significantly increased, while the specific leaf area of C. squarrosa significantly decreased. All three gramineous showed increased resistance traits in response to Brandt's voles, which positively affected their dominance. Tolerance-related traits of S. krylovii significantly increased, with the increasing growth rate of root length contributing to enhancing its dominance. We highlight that selective feeding by rodents led to the selection of different defense strategies by three gramineous plants, and that changes in biomass allocation and functional traits in the different species affected plant dominance, driving changes in the plant communities.

Динамика биологических показателей возвратных гибридов на основе кастера (калуга Huso dauricus × стерлядь Acipenser ruthenus) (Acipenseridae)

Due to the lack of conditions for industrial sturgeon fishing in the near future, the current artificial reproduction programs play a leading role in replenishing sturgeon populations and commercial sturgeon breeding. It may take a long time to bring the number of individuals and the total biomass of sturgeon fish species in different water basins into proper condition. It is important, along with the implementation of programs for the stocking of young sturgeons of various types of natural habitats, to develop commercial cultivation. Modern aquaculture is the use of environmental control systems, timely feed supply, rapid growth of juveniles with a minimum feed ratio, high survival rate at all stages of growth, greater yield of edible body parts during processing. The dynamics of size and mass indices and the Fulton fatness coefficient in recurrent hybrids of different ages (K × St) are considered × K, (K × St) × St, (St × K) × K and (St × K) × St. It is noted that the fastest growing hybrids turned out to be returnable hybrids based on K × St, and the hybrid (St × K) × St has the highest fatness coefficient with a slight growth rate of weight and length.