Initial Length Research Articles

Molecular dynamics simulation of CL-20 based high temperature resistant PBX.

To address the issue that the output charge in existing Deflagration to Detonation Transition (DDT) detonators cannot withstand high temperatures of 200°C, and to improve the output performance of the detonator, a CL-20 (Hexanitrohexaazaisowurtzitane) based polymer bonded explosive (PBX) was investigated as the primary charge material for the detonator. To select the most suitable binder for thermal resistance, molecular dynamics (MD) simulations were employed to evaluate the performance of different binders at various crystal planes and temperatures. The results indicate that among the five PBXs models, CL-20/F2602 exhibits the highest binding energy and the shortest bond initiation length at both ambient and elevated temperatures. CL-20/F2611 demonstrates stronger hydrogen bonding interactions and superior thermal stability at high temperatures. CL-20/PCTFE shows the best ductility, while CL-20/F2602 possesses the second-best ductility. Therefore, PBXs containing F2602 possess the best stability, compatibility, and satisfactory ductility, while PBXs with F2611 exhibit the best thermal stability. Both F2602 and F2611 are suitable as binders for CL-20. Molecular dynamics (MD) simulations were carried out using the Materials Studio software to calculate the binding energies, trigger bond lengths, and mechanical properties of five PBX models at different crystal planes at 298K, and at various temperatures on the (0 1 1) crystal plane after a 1ns NPT dynamics simulation. The total MD simulation time was 1ns, with a time step of 1fs, and the COMPASS force field was employed throughout the simulation.

Effects of Choline Supplementation in Diets on Juvenile Pacu (Piaractus mesopotamicus): Productive Performance, Proximate Composition and Serum Lipid Level.

Pacu (Piaractus mesopotamicus) is a Brazilian fish species of high commercial value and has emerged as one of the main species with potential for intensive farming. This study aimed to investigate the impact of choline supplementation on productive performance, visceral fat, hepatosomatic indices, proximate composition, serum biochemical profile, and liver coloration in juvenile pacu (Piaractus mesopotamicus). The 60-day experiment was conducted in the experimental hatchery of the Study Group of Aquaculture Management - GEMAq of the State University of West Paraná, Brazil. The completely randomized design consisted of five treatments with four replicates each. A total of 200 fish, with an average initial weight and length of 4.25 g and 5.97 cm, were distributed among 20 experimental hapas, resulting in a stocking density of 10 fish per experimental unit. Fish fed a choline-deficient diet exhibited the lowest values for final weight, weight gain, visceral fat, and hepatosomatic index. Conversely, in terms of proximate composition, fish fed choline-deficient diets had the highest moisture content but the lowest crude fat content. Triglyceride levels in juvenile pacu were significantly higher in groups fed diets containing choline (400 to 1200 mg kg-1 ). We also observed significant differences in the cyan color of the liver (P < 0.05). Notably, we observed significant differences in the cyan coloration of the liver (P < 0.05). Other parameters did not exhibit significant changes in response to varying choline levels in the diets. Our study demonstrated that choline supplementation in P. mesopotamicus juveniles at an optimal concentration of 400 mg kg-1 significantly impacted growth, metabolism, productive performance, proximate composition, biochemical parameters, and liver color. These findings offer crucial guidance for aquaculture professionals, enabling them to enhance growth and health in P. mesopotamicus farming. Further research on choline's influence on lipid metabolism holds potential for more precise dietary recommendations, ultimately improving the efficiency and sustainability of aquaculture practices for this species.

Expansion wave-reinforced initiation of the oblique detonation wave

Efficient initiation of oblique detonation waves (ODWs) is crucial for optimizing the performance of oblique detonation wave engines. A novel approach is proposed for enhancing ODW initiation through expansion waves in this research. Validation of the expansion wave-reinforced initiation method is conducted via numerical simulations employing multi-species reactive Euler equations and a pressure-dependent reaction mechanism. Results demonstrate a significant reduction in the initiation length of ODWs with the addition of an expansion wave ahead of the wedge, contrasting with the absence of detonation wave initiation on a wedge lacking an expansion wave. A theoretical model, based on expansion wave and shock wave relations, along with constant volume combustion theory, elucidates the underlying mechanism of reinforcement. The model reveals that crossing the expansion wave elevates the fluid's Mach number and locally enlarges the flow deflection angle on the wedge surface, without altering the wedge's structure. Furthermore, post-shock temperature increases and pressure decreases compared to the wedge not encountering an expansion wave. The heightened temperature predominantly triggers ODW initiation, thus reinforcing the process. Theoretical analyses indicate the reinforcement's greater efficacy at lower inflow temperatures and lower inflow Mach numbers, suggesting the expansion wave's suitability for initiation in the early flight stages of an aircraft equipped with oblique detonation wave engines.

Flow characteristics and propulsive performance of oblique detonation waves induced by a transverse jet

The initiation of oblique detonation waves (ODWs) is a key component of the successful application of oblique detonation wave engines (ODWEs). This paper numerically investigates the initiation of ODWs under the active control of a transverse jet by solving the two-dimensional multi-species Euler equations, focusing on the morphology of the flow fields as well as the relationship between the flow structures and propulsive performance using the concept of thrust potential. Active jet control significantly shortens the initiation length of the ODW. The results reveal that the jet-induced flow field shows four typical patterns depending on the jet momentum flux ratio and wedge angle: shock-induced combustion, a type I pattern, a type II pattern, and a type I-II pattern. For the jet-induced ODW flow field, the propulsive performance declines as the momentum flux ratio increases when the wedge angle is certain. The larger the wedge angle, the greater the magnitude of the decline. The thrust of the flow field consists of two main components: the thrust generated by the mixture that passes first through the oblique shock wave and then through the detonation wave, and the thrust generated by the mixture that passes directly through the ODW front. Since the ODW upstream front has a larger wave angle, the flow loss of the mixture passes through the ODW upstream front is higher and the thrust potential is lower. This work could guide the active control of the initiation of ODWs at low flow losses.

Morphophysiological and biochemical responses of photoperiodic and temperature manipulations on growth and quality of cut stems of chrysanthemum

ABSTRACT The cut stem quality of Chrysanthemum varieties (Yellow Delight, Reagan Emperor, Reagan White, Shova and Punjab Shyamli) were evaluated in response to photoperiodic manipulations through Early planting (P1), Early planting with artificial short days (SDs) (P2) and Normal planting (P3). Cut stem length increased by 25.54% under P2 (79.77 cm) as compared to P3 (59.40 cm), whereas the number of flowers remained at par. Planting time and artificial SDs significantly influenced biochemical and morphological differentials. Membrane stability index (78.21), total soluble sugars (87.29 mg g−1 FW), total soluble proteins (90.85 mg g−1 FW), proline (17.57 mg g−1 FW) and peroxidase activity (16.37 Δ in absorbance min−1 g−1 FW) of Yellow Delight under P2 contributed to 1.39 times increase in its cut stem length over P3 and made it fit for P1 and P2 planting. Punjab Shyamli and Reagan Emperor exhibited luxuriant vegetative growth, whereas quality of Reagan White and Shova improved under P2. Principal component analysis revealed that days to bud initiation, days to flowering, peroxidase activity, membrane stability index, proline at bud initiation and cut stem length contributed significantly to variation (60.48%) among treatments. Moreover, cut stem length, correlated positively with days to bud initiation and flowering, TSS and peroxidase activity, leaf area and SLA, suggesting their importance in breeding for off-season flowering and quality enhancement.

Propagation instabilities of the oblique detonation wave in partially prevaporized n-heptane sprays

Two-dimensional oblique detonation wave (ODW) propagations in partially prevaporized n-heptane sprays are numerically simulated with a skeletal chemical mechanism. The influences of the droplet diameter and total equivalence on oblique detonation are considered. The initiation length is found to increase first and then decrease with increasing initial droplet diameter, and the effect of droplet size is maximized when the initial droplet diameter is approximately $10\ \mathrm {\mu } {\rm m}$ . As the initial droplet diameter varies, unsteady and steady ODWs are observed. In the cases of unsteady ODWs, temperature gradients and non-uniform distributions of the reactant mixture due to droplet evaporation lead to formation of unsteady detonation propagation, therefore leading to fluctuations in the initiation length. The fluctuations in initiation length decrease as the pre-evaporation gas equivalence ratio increases for the unsteady cases. The results further suggest that the relationship between the evaporation layer thickness along the streamline and the corresponding theoretical initiation length can be used to identify an unsteady or steady ODW in cases with large droplets that evaporate behind an oblique shock wave or ODW under the effects of different initial droplet diameters.

Quantifying noise effects in optical measures of excited state transport.

Time-resolved microscopy is a widely used approach for imaging and quantifying charge and energy transport in functional materials. While it is generally recognized that resolving small diffusion lengths is limited by measurement noise, the impacts of noise have not been systematically assessed or quantified. This article reports modeling efforts to elucidate the impact of noise on optical probes of transport. Excited state population distributions, modeled as Gaussians with additive white noise typical of experimental conditions, are subject to decay and diffusive evolution. Using a conventional composite least-squares fitting algorithm, the resulting diffusion constant estimates are compared with the model input parameter. The results show that heteroscedasticity (i.e., time-varying noise levels), insufficient spatial and/or temporal resolution, and small diffusion lengths relative to the magnitude of noise lead to a surprising degree of imprecision under moderate experimental parameters. Moreover, the compounding influence of low initial contrast and small diffusion length leads to systematic overestimation of diffusion coefficients. Each of these issues is quantitatively analyzed herein, and experimental approaches to mitigate them are proposed. General guidelines for experimentalists to rapidly assess measurement precision are provided, as is an open-source tool for customizable evaluation of noise effects on time-resolved microscopy transport measurements.

Edible Soft Actuators Based on Konjac Glucomannan for Underwater Operation

Soft robots are being increasingly developed and deployed for underwater applications such as exploration, monitoring, and rescue owing to their innate compliance, mechanical and chemical stability, and waterproof properties. However, they are still predominantly manufactured using silicones and acrylic elastomers, which pose environmental risks due to their limited biodegradability. To tackle this issue, a method for manufacturing water‐resistant, liquid‐driven soft actuators made from a novel type of konjac glucomannan (KGM) is presented, which is plant‐derived, insoluble, and edible. The material offers impressive stretchability, reaching up to 67.2% of its initial length, surpassing previous related work, and withstands over a 1000 cycles of tensile stress. Using this material, we develop soft actuators that can bend up to 47.1°, and the maximum blocking force of 0.1 N is achieved with a pressure input of 20 kPa. A gripper that is capable of grasping various objects underwater is also evaluated. In essence, this article introduces a sustainable and environmentally friendly alternative to conventional soft robotic materials, paving the way for innovative and eco‐conscious underwater applications. The utilization of edible, water‐resistant materials like konjac provides a promising solution to reduce pollution and mitigate negative environmental impacts associated with traditional underwater soft robots.

Effect of initial crack length, cross-head speed, and quenching on the fracture toughness of HDPE with and without UV stabilizers

Effect of initial crack length, cross-head speed, and quenching on the fracture toughness of HDPE with and without UV stabilizers

Admission avoidance hospital at home.

Admission avoidance hospital at home provides active treatment by healthcare professionals in the patient's home for a condition that would otherwise require acute hospital inpatient care, and always for a limited time period. This is the fourth update of this review. To determine the effectiveness and cost of managing patients with admission avoidance hospital at home compared with inpatient hospital care. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and CINAHL on 24 February 2022, and checked the reference lists of eligible articles. We sought ongoing and unpublished studies by searching ClinicalTrials.gov and WHO ICTRP, and by contacting providers and researchers involved in the field. Randomised controlled trials recruiting participants aged 18 years and over. Studies comparing admission avoidance hospital at home with acute hospital inpatient care. We followed the standard methodological procedures expected by Cochrane and the Effective Practice and Organisation of Care (EPOC) Group. We performed meta-analysis for trials that compared similar interventions, reported comparable outcomes with sufficient data, and used individual patient data when available. We used the GRADE approach to assess the certainty of the body of evidence for the most important outcomes. We included 20 randomised controlled trials with a total of 3100 participants; four trials recruited participants with chronic obstructive pulmonary disease; two trials recruited participants recovering from a stroke; seven trials recruited participants with an acute medical condition who were mainly older; and the remaining trials recruited participants with a mix of conditions. We assessed the majority of the included studies as at low risk of selection, detection, and attrition bias, and unclear for selective reporting and performance bias. For an older population, admission avoidance hospital at home probably makes little or no difference on mortality at six months' follow-up (risk ratio (RR) 0.88, 95% confidence interval (CI) 0.68 to 1.13; P = 0.30; I2 = 0%; 5 trials, 1502 participants; moderate-certainty evidence); little or no difference on the likelihood of being readmitted to hospital after discharge from hospital at home or inpatient care within 3 to 12 months' follow-up (RR 1.14, 95% CI 0.97 to 1.34; P = 0.11; I2 = 41%; 8 trials, 1757 participants; moderate-certainty evidence); and probably reduces the likelihood of living in residential care at six months' follow-up (RR 0.53, 95% CI 0.41 to 0.69; P < 0.001; I2 = 67%; 4 trials, 1271 participants; moderate-certainty evidence). Hospital at home probably results in little to no difference in patient's self-reported health status (2006 patients; moderate-certainty evidence). Satisfaction with health care received may be improved with admission avoidance hospital at home (1812 participants; low-certainty evidence); few studies reported the effect on caregivers. Hospital at home reduced the initial average hospital length of stay (2036 participants; low-certainty evidence), which ranged from 4.1 to 18.5 days in the hospital group and 1.2 to 5.1 days in the hospital at home group. Hospital at home length of stay ranged from an average of 3 to 20.7 days (hospital at home group only). Admission avoidance hospital at home probably reduces costs to the health service compared with hospital admission (2148 participants; moderate-certainty evidence), though by a range of different amounts and using different methods to cost resource use, and there is some evidence that it decreases overall societal costs to six months' follow-up. Admission avoidance hospital at home, with the option of transfer to hospital, may provide an effective alternative to inpatient care for a select group of older people who have been referred for hospital admission. The intervention probably makes little or no difference to patient health outcomes; may improve satisfaction; probably reduces the likelihood of relocating to residential care; and probably decreases costs.

Plant-based carotenoid supplementation: Growth, feed utilization efficiency, and coloration in false clownfish (Amphiprion ocellaris)

The false clownfish (Amphiprion ocellaris) is a prominent species in the marine ornamental trade, valued for its vibrant orange-red coloration. However, aquaculture-bred individuals often exhibit less intense coloration than their wild counterparts, presenting a challenge for both breeders and aquarists. This study evaluates the effects of carotenoid-enriched diets, sourced from natural ingredients such as pumpkin, bell pepper, carrot, and gac, as well as a synthetic source like astaxanthin, on the coloration and growth of false clownfish. In a controlled experiment, juvenile fish with an initial average length of 3.21 ± 0.03 cm and weight of 0.61 ± 0.02 g were allocated to 60-liter tanks and fed the experimental diets over a 75-day trial period. Carotenoid supplementation was standardized at 250 mg/kg across diets, with a control group receiving no added carotenoids. The experimental design was completely randomized, involving three replicates per dietary treatment. The results indicated that diets supplemented with gac and bell pepper significantly enhanced growth and feed efficiency (p &lt; 0.05). Notably, the skin redness intensity (a* value) was increased by 75.73% in the gac-supplemented group, 89.20% in the bell pepper group, and 91.99% in the astaxanthin group, relative to the control (p &lt; 0.05). Additionally, carotenoid deposition in the integument was significantly higher in all supplemented groups, with an increase of 83.74% in the astaxanthin group, 89.59% in the gac group, and 98.43% in the bell pepper group, compared to the control (p &lt; 0.05). These findings suggest that natural carotenoids, particularly from gac and bell pepper, can be effective alternatives to synthetic astaxanthin, potentially improving the attractiveness and commercial value of captive-bred false clownfish and alleviating the exploitation of wild populations.

MRI-based central sarcopenia negatively impacts the therapeutic effectiveness of single-segment lumbar fusion surgery in the elderly

Central sarcopenia is associated with the prognosis of various orthopedic surgeries in the elderly. This study aims to investigate its impact on the outcomes of single-segment lumbar fusion surgery in elderly patients. Retrospective analysis was conducted on 314 patients aged 60 to 80 who underwent single-segment posterior lumbar fusion surgery due to degenerative lumbar diseases. Patients were categorized into high psoas and L4 vertebral index (PLVI) and low PLVI groups according to the MRI-measured PLVI for central sarcopenia. Basic patient data, surgery-related parameters, functional assessments at preoperative and postoperative 3, 6, and 12 months, and X-ray-based fusion status were compared. The basic data of the two groups showed no significant differences. Parameters including the operative segment, preoperative hemoglobin levels, surgical duration, and intraoperative blood loss exhibited no significant variances. However, notable differences were observed in postoperative initial hemoglobin levels, transfusion requirements, and length of hospital stay between the two groups. During the postoperative follow-ups at 3, 6, and 12 months, the VAS scores for lower back pain and ODI scores in the lower PLVI group were significantly higher compared to the high PLVI group. Additionally, the EuroQoL 5D scores were notably lower in the low PLVI group. There were no significant differences between the groups in terms of leg pain VAS scores at each time point and the fusion status at 12 months postoperatively. MRI-based central sarcopenia has a negative impact on the therapeutic effectiveness following single-segment lumbar fusion surgery in elderly patients.

Dynamics of Taylor bubble under chemical reaction enhanced mass transfer in minichannel

Dynamics of Taylor bubble under chemical reaction enhanced mass transfer in minichannel

Impacts of geomechanical damage on waterflood-induced fracture propagation in deeply deposited tight oil reservoirs

Waterflood-induced fractures can enhance the production of deep tight oil reservoirs. However, if waterflood-induced fractures propagate fast, they connect injection wells to production wells earlier, inhibiting the production of tight oil reservoirs. In the present research, the fast propagation mechanism of waterflood-induced fractures was mainly investigated. The changes in sandstone mechanical properties by water were investigated by laboratory experiments, and the relationship of the geomechanical damage of sandstones with water saturation was quantified. Flow-geomechanics-coupled numerical simulations were performed to analyze the impacts of water flooding on stress distribution in a deeply deposited tight oil reservoir. Based on the fracture mechanics theory, the propagation length of the waterflood-induced fracture was calculated and the characteristics of waterflood-induced fracture propagation were analyzed. Experimental results revealed that water changed the mineral composition and microscopic structure of sandstones. This phenomenon decreased the Young’s modulus and tensile strength of sandstones and increased the Poisson’s ratio. The changing magnitude of these properties increased with the rise of water saturation, and the maximum changing magnitude reached 70%. The water saturation distribution became heterogeneous after waterflooding, causing a heterogeneous distribution of mechanical properties. The stress around the fracture tip and the fracture propagation length were significantly affected by these property changes. After the geomechanical damage, the fracture propagation pressure decreased by about 20%. Moreover, the initial fracture length enhanced the propagation length of the waterflood-induced fracture. These results suggest that the propagation of waterflood-induced fractures becomes more significant during waterflooding; thus, the injection pressure should be reduced to avoid fast fracture propagation.

Annihilation of electroweak dumbbells

We study the annihilation of electroweak dumbbells and the dependence of their dynamics on initial dumbbell length and twist. Untwisted dumbbells decay rapidly while maximally twisted dumbbells collapse to form a compact sphaleron-like object, before decaying into radiation. The decay products of a dumbbell include electromagnetic magnetic fields with energy that is a few percent of the initial energy. The magnetic field from the decay of twisted dumbbells carries magnetic helicity with magnitude that depends on the twist, and handedness that depends on the decay pathway.

Finite-Element Modeling of the Dynamic Behavior of a Crack-like Defect in an Internally Pressurized Thin-Walled Steel Cylinder

This article presents one part of a study on the dynamic deformation and fracture of sections of steel gas pipelines with an external crack-like defect under the action of internal pressure. This work was performed on the basis of finite-element simulations using a cylindrical shell model executed by ANSYS-19.2 on the example of the section of the steel gas pipeline “Beineu–Bozoy–Shymkent” in the Republic of Kazakhstan. The propagation of the incipient crack-like defect along the pipeline and the resulting dynamic fracture in its tip area were investigated. The options of pipeline loading by working and critical internal pressure were both considered. It was found that, within the time of 1.0 ms, the formed crack expanded in the circumferential direction up to the maximum value, which depended on the value of the internal pressure. A further growth of cracks occurred along the longitudinal direction. At the operating pressure, the initial length of the crack increased by a factor of 5.6, while the equivalent stresses increased by a factor of 1.53 within 3.5 ms. Within the time of 3.75 ms, the equivalent stresses stopped growing due to the gas decompression. Specifically, there was a stop to the crack growth along the longitudinal direction. Vice versa, at the maximum pressure, the pipeline fracture did not change qualitatively, while at the time of the process, it decreased up to 3.5 ms. The finite-element results of the stress–strain state and pipeline fracture in the crack tip area at the working pressure showed that, within the time of 1.0 ms, the distance between the crack walls reached 23 mm at the free edge. Conversely, within the time periods of 2.25 and 3.5 ms, it increased two and three times, respectively. The crack elongation in the longitudinal direction occurred 5.8 times with time. Together, within the time of 3.5 ms, the equivalent stresses increased twice, after which the growth of the crack stopped due to the gas decompression. Moreover, studies on the growth of the crack-like defect in its tip area at the maximum pressure showed that additional considerations on the pressure on the crack edges led to an increment of 3.6% of the crack length. The results of this work can be used for the development of measurements for operating gas pipelines in the field of structural reinforcement.

Height best predicts the optimal insertion length of orotracheal tubes in children

IntroductionAccurate formulae to predict the optimal insertion length of endotracheal tubes (ETT) are necessary for safe care and have been based on height, weight, age, and ETT size. We believe height best reflects the somatic growth of the trachea. Our goal is to compare a formula generated using height for optimal initial insertion length of ETT to previously published formulae based on height, weight, age, and ETT size.MethodsWe retrospectively reviewed chest radiographs over a two-year period where the head was assured in midline and midposition. We excluded children with conditions altering tracheal dimensions or stature, and scoliosis. We chose 2 cm above the carina to be the optimal insertion length of the ETT which was then correlated to height. We created linear regression equations and Bland-Altman plots.ResultsTwo hundred three orotracheally intubated children were included. The optimal ETT insertion length using the formula Height (cm)/8 + 3.4 had a high association with linear regression and Bland-Altman plots had the narrowest 95% limits of agreement as compared to previously published formulae.ConclusionsWe found optimal insertion length = Height (cm)/8 + 3.4 is more accurate as compared to commonly used formulae that are based on weight, age, or ETT size. This formula places the ETT 2 cm above the carina which should be safe until a chest radiograph is obtained. We find that the use of formulae that divide the height by 10 overestimates the depth of insertion in younger, smaller children and underestimates the depth of insertion in older children.

Limb lengthening and deformity correction in patients with severe fibular hemimelia: experience of the children's university hospital in Belgrade

Background Fibular hemimelia (FH) is a congenital disease manifested by valgus deformity and instability of the knee joint, shortening and deformity of the tibia, hypoplasia and deformities of the foot and ankle.The aim of this paper was to determine the efficacy of the strategy of separate reconstruction of the foot along with correction of tibia deformity, and then tibial lengthening in patients with FH of types 3 and 4 according to Paley.Methods This retrospective study is based on an analysis of the treatment of 12 children with severe FH. The patients, aged no older than 24 months, were treated for foot reconstruction along with correction of tibial deformity followed by a separate stage of tibial lengthening. Tibial lengthening was performed in the age 4.6 ± 1.2 years. The long-term result of treatment was evaluated at least 1 year after the end of tibial lengthening. Evaluation criteria after tibia lengthening were external osteosynthesis index, amount of lengthening, assessment of outcomes according to Lascombes. Walking ability was assessed using Gillette questionnaire.Results The approach we used gave excellent and good results in 83 % of cases after the first reconstructive stage. Complications and recurrences of deformities encountered during the first stage were eliminated during subsequent planned limb lengthening. The average magnitude of lengthening was 6.4 ± 2.4 cm (37.2 ± 12.4 % of the initial segment length). The index of external osteosynthesis was 22.9 ± 12.2 days/cm. Monofocal distraction osteosynthesis was used in 9 cases and bifocal osteosynthesis in three cases. The results of lengthening were classified by Lascombes as IA in 7 cases, IB in four cases, 2B in one case.Discussion In severe FH, the question of reconstruction or early amputation remains open. There are two opinions on the staging of reconstructive orthopedic surgery and tibial lengthening in young children with severe FH.Conclusion The strategy of reconstruction of the foot and ankle joint at an early age (16-24 months) in children with severe FH followed by lengthening of the lower leg (at the age of 4-6 years) proved to be effective and can be used when it is chosen by the patient's parents. In 3C type cases, the use of external fixation to correct the deformity and simultaneously lengthen the tibia at the first stage is an alternative reasonable strategy option.

Response of various carbon sources for in vitro culture establishment and shoot proliferation of banana cv. Chinichampa (AAB) through shoot tip

Bananas are one of the most important tropical fruits in the world market, a significant staple food and a major export commodity. In vitro propagated banana plants are steadily becoming the planting material of choice because of disease free, uniformity and the possibility of rapid multiplication. The present investigation was carried out at the tissue culture laboratory, Department of Horticulture, School of Agricultural Sciences, Nagaland University, Medziphema campus during the year 2019-2022. Data recorded for different parameters viz. days to greening, days required for multiple buds’ initiation, number of multiple buds produced per explant and length of multiple buds after 30 days were subjected to completely randomized design (CRD). The present study revealed the importance of various carbon sources and its role in micropropagation of banana through shoot tip culture. The minimum day to greening, multiple buds initiation and maximum length of multiple buds was observed in shoot proliferation medium supplemented (SPM S) with 30g sucrose. The highest number of multiple buds was recorded in shoot proliferation medium supplemented with 30g table sugar. The results indicate the significance of sucrose as carbon sources in micropropagation of banana. They improved plant regeneration and facilitated rapid multiplication of disease and virus free banana plantlets.

Paternal heat exposure affects progeny larval development in green-lipped mussels Perna canaliculus

The green-lipped mussel Perna canaliculus is critically important to the New Zealand aquaculture industry. However, the rise in marine heatwave (MHW) events poses an emerging threat to this industry through summer mortality events. This study investigated the potential for paternally mediated transgenerational plasticity to improve offspring performance under heat stress. We simulated a week-long MHW event, exposing male P. canaliculus broodstock to elevated (22°C) or ambient (17.5°C) temperatures immediately prior to spawning, and evaluated the effects of paternal heat exposure on successful development, size and acute thermal tolerance of their larvae that were also reared under ambient or elevated (20°C) temperatures through to completion of the lecithotrophic trochophore stage. Elevated paternal and larval temperatures both increased incidence of abnormal development, reducing larval yield, while initial D-veliger shell length was predominantly influenced by developmental temperature, with longer shells formed at 20°C. Veligers from heat-exposed fathers raised under 20°C showed a small, but significant, elevation in lethal tolerance 50 (LT50), the temperature at which 50% of the larvae are predicted to die, when exposed to an additional 1 h heat-shock. These results indicate that paternal heat exposure over a relatively short period can influence offspring performance in this species. The paternal exposure investigated showed limited positive effects on offspring thermal tolerance, which may be outweighed by the negative impact on larval development. As MHWs are forecasted to continue accelerating, understanding transgenerational effects of heat stress will be critical for maintaining high-quality hatchery yields through broodstock selection and may inform wild population forecasting models.