Structural Defenses Research Articles

Proposed Technique for Estimating Rainwater Storage Tank Locations Using Vulnerability Analysis of Critical Flooding Nodes

Even if a pumping station, which is a representative structural flood defense facility, operates optimally, flooding occurs at certain nodes in the drainage area. In other words, even if rainwater pumping stations and rainwater storage tank, which are structural flood defense measures, operate at maximum, it is necessary to review areas where overflow occurs. Therefore, in areas where it is impossible to protect against inland flooding using structural flood defense measures alone, new flood defense measures are required. In this study, based on previous research on rainwater pumping station operation techniques to reduce critical flooding, the Daelim 3 region was divided into 45 basic areas and vulnerability analysis techniques were applied to select the location of rainwater storage tank for effective flood defense. A possible technique is presented in this paper. As a result of the study, sub-region 1 had the highest impact index value, so installing a rainwater storage tank was calculated to be more effective in preventing floods than installing a rainwater storage tank in other sub-regions. The priority-estimation technique for flood defense facilities presented in this study can be effective in establishing plans for flood control structures other than rainwater storage tank.

Bioinspired Hierarchical T Structures for Tunable Wettability and Droplet Manipulation by Facile and Scalable Nanoimprinting.

Developing surfaces that effectively repel low-surface-tension liquids with tunable adhesive properties remains a pivotal challenge. Micronano hierarchical re-entrant structures emerge as a promising solution, offering a robust structural defense against liquid penetration, minimizing area fraction, and creating narrow gaps that generate substantial upward Laplace pressure. However, the absence of an efficient, scalable, and tunable construction method has impeded their widespread applications. Here, drawing inspiration from springtail epidermal structures, octopus suckers, and rose petals, we present a scalable manufacturing strategy for artificial micronano hierarchical T-shaped structures. This strategy employs double-transfer UV-curing nanoimprint lithography to form nanostructures on microstructured surfaces, offering high structural tunability. This approach enables precise control over topography, feature size, and arrangement of nano- and microscale sections, resulting in superamphiphobic surfaces that exhibit high contact angles (>150°) and tunable adhesive forces for low-surface-energy liquids. These surfaces can be applied to droplet-based microreactors, programmable droplet-transfer systems, and self-cleaning surfaces suitable for various liquids, particularly those with low surface tension. Remarkably, we have also succeeded in fabricating the hierarchical structures on flexible and transparent substrates. We demonstrate the advantages of this strategy in the fabrication of hierarchical micronanostructures, opening up a wide range of potential applications.

Exploring the interplay between host plant structural defences and origin on behavioural and life‐history traits of two Neotropical danaines

AbstractFactors that mediate insect herbivore sabotaging behaviour of host plant latex defences remain under debate. The most prominent hypothesis suggests that the anatomy of the host plant's laticifers determines trenching or vein‐cutting behaviour, but there are inconsistencies in the literature. In addition to latex, other plant defences have been shown to affect plant natural enemies, but experimental studies comparing the effects of multiple defences on herbivore performance and behaviour are scarce. In this study, we investigated the anatomy of the laticifers of Calotropis procera (Aiton) W.T. Aiton (Apocynaceae), an exotic milkweed of southeastern Brazil, as well as the sabotaging behaviour of larvae of southern monarch, Danaus erippus (Cramer), and queen butterfly, Danaus gilippus (Cramer) (Lepidoptera: Nymphalidae) on this host plant. We also reviewed the sabotaging behaviour of larvae reared on the native milkweed Asclepias curassavica L. (Apocynaceae) from previous studies, as well as the description of the anatomy of its laticifers. As we found no correspondence between sabotaging behaviour of southern monarchs and queens and the anatomy of the host plants' laticifers, we tested whether structural defences of C. procera leaves (latex, waxes and trichomes) affected sabotaging behaviour and larval performance of southern monarch larvae. The structural barriers of this well‐defended host affected larvae in different ways: Southern monarchs developed more slowly on control leaves than on leaves from which wax had been removed, and only latex removal reduced the frequency of sabotaging behaviour. Regardless of the defence removal treatment, frequencies of trenching behaviour decreased and vein‐cutting behaviour increased as larvae developed. Overall, our results show that several factors in addition to the anatomy of laticifers affect sabotaging behaviour of southern monarchs and queens, including larval ontogeny, danaine species and latex outflow. This evidence suggests a behavioural plasticity in the sabotaging behaviour of larvae of both southern monarchs and queens.

Significance of lignin and fungal markers in the Devonian (407 Ma) Rhynie Chert.

The Rhynie Chert (Lower Devonian, Scotland) hosts a remarkably well-preserved early terrestrial ecosystem. Organisms including plants, fungi, arthropods, and bacteria were rapidly silicified due to inundation by silica-rich hot spring fluids. Exceptional molecular preservation has been noted by many authors, including some of the oldest evidence of lignin in the fossil record. The evolution of lignin was a critical factor in the diversification of land plants, providing structural support and defense against herbivores and microbes. However, the timing of the evolution of lignin decay processes remains unclear. Studies placing this event near the end of the Carboniferous are contradicted by evidence for fungal pathogenesis in Devonian plant fossils, including from the Rhynie Chert. We conducted organic geochemical analyses on a Rhynie Chert sample, including hydropyrolysis (HyPy) of kerogen and high-resolution mass spectrometric mapping of a thin section, to elucidate the relationship between lignin and the potential fungal marker perylene. HyPy of kerogen showed an increase in relative abundance of perylene supporting its entrapment within the silicate matrix of the chert. Lignin monomers were isolated through an alkaline oxidation process, showing a distribution dominated by H-type monomers. G- and S-type monomers were also detected, preserved by rapid silicification. Polycyclic aromatic hydrocarbons including perylene, a known marker for lignin-degrading fungi, were also concentrated in the kerogen and found to be localized within silicified plant fragments. Our results strongly link perylene in the Rhynie Chert to the activity of phytopathogenic fungi, demonstrating the importance of fungal degradation processes as far back as the Early Devonian.

Understanding Adolescent Mental Health in the COVID-19 Era: A Psychodynamic Approach.

This cross-sectional, case-control study aimed to explore the psychodynamic characteristics that influenced adolescents' mental health during the COVID-19 pandemic. Personality structure impairments, psychodynamic conflicts, defense styles, and mental health issues were examined using the OPD-Structure- and Conflict-Questionnaires, the Defense Style Questionnaire, and the Patient Health Questionnaire in adolescents before (n = 288) and after (n = 451) the COVID-19 pandemic in Germany. Adolescents with mental health issues exhibited greater impairments in personality structure, more immature defense styles, and higher levels of psychodynamic conflicts both before and after the pandemic onset. Comparisons between pre-pandemic and pandemic samples indicated a lower level of the conflict of taking care of oneself versus being cared for in passive mode among adolescents during the pandemic. In-depth analysis of adolescents with mental health issues from the pandemic group revealed significant associations between personality structure impairments and a maladaptive defense style with somatoform, depressive, anxiety, eating, and alcohol use disorders. The findings provide clinically relevant insights into the psychodynamic factors that contributed to the psychological vulnerability of adolescents during the COVID-19 pandemic. These insights can guide the development of targeted psychodynamic interventions to support adolescents' mental health in similar future crises.

Assessing coupled human-flood interactions using LiDAR geostatistics and neighbourhood analyses

The paper integrates well-established methods from other spheres of flood risk assessment in a novel way to explore the currently poorly understood Safe Development Paradox (SDP) phenomenon in coastal settings. The study contributes to addressing this knowledge gap based on insights from contrasting UK case studies: Portsmouth, Weston-super-Mare, and Southport. Differential analysis of historic LiDAR Digital Surface Models (DSMs) was used to identify temporal changes in the urban landscape to create a DSM of Difference (DoD), representing elevation change between two locations over time. Geostatistical testing, specifically t-tests, were then used to infer statistical significance of changes in urban development. The findings reveal a consistent pattern: following completion or improvement of large-scale structural coastal flood defences, there is subsequent, and statistically significant, increases in urban development within/near flood-exposed areas across all three case studies, contrary to the limited flood-exposed development in neighbouring settlements, with no comparable defences constructed during the same period. On average, new urban development occurs approximately 2 years after the completion of coastal flood defence projects. The study emphasises the importance of context-specific and neighbourhood analyses, considering settlement size, economy, and extraneous factors influencing the nature of development to better understand the SDP’s long-term implications.

Kajian Psikoanalisis Sigmund Freud Berbasis Novel Karya Tulus Setiyadi untuk Menangani Kecemasan

Anxiety is one of the most common psychological problems experienced by everyone. The novel Kasrimpet Piweling and Puspita Rinengga by Tulus Setiyadi is one of the literary works that raises the issue of anxiety for its characters. Therefore, this research will discuss the anxiety of the main character in the novels Kasrimpet Piweling and Puspita Rinengga by Tulus Setiyadi using the psychoanalytic view proposed by Sigmund Freud. This research aims to explain the anxiety experienced by the main character in both novels. The theory used in this research is Sigmund Freud's psychoanalysis theory. Data collection with literature study method using library techniques, reading, recording and classification. Data analysis is done by looking at the personality structure, anxiety and ego defense mechanisms used by the characters. This type of research is literary research using descriptive method. The research data are in the form of words, phrases, clauses, sentences, narration from the narrator, characters' speech, and characters' actions related to ego defense mechanisms in Kasrimpet Piweling and Puspita Rinengga novels. The data collection techniques in this research are as follows: (1) conducting a literature study, (2) reading and understanding the novel, (3) marking the parts of the novel that indicate id, ego, and super ego (4) identifying the main characters and additional characters in the novel, (5) recording the data in the novel.

Lactiplantibacillus plantarum IS-10506 Enhances Tight Junction Integrity in Bronchial Epithelium: An Experimental Study

BACKGROUND: Airway epithelium constitutes the initial structural defense against inhaled allergens, with its integrity primarily maintained through the formation of tight junctions (TJ) consisting of claudins, occludins, and zonula occludens (ZO). Currently, the effects of probiotics on airway TJ remain unclear. Therefore, this study was conducted to explore the impact of Lactiplantibacillus plantarum IS-10506, a native probiotic from Indonesia, on bronchial epithelial TJ in a mouse model of allergic airway inflammation.METHODS: Twenty-four BALB/c mice were randomly assigned to three groups: negative control, positive control subjected to Dermatophagoides pteryonissinus (Der p) sensitization and challenge, and treatment group exposed to Der p and administered L. plantarum IS-10506 since one week before sensitization up to three weeks after. The expression levels of claudin-18, occludin, and ZO-1 were investigated through immunohistochemistry analysis and quantified based on the immunoreactive score (IRS). RESULTS: The results of this study demonstrated that L. plantarum IS-10506 significantly enhanced the expressions of claudin-18, occludin, and ZO-1 (p<0.05).CONCLUSION: These findings underscore the probiotic's role in fortifying the integrity of airway TJ.KEYWORDS: allergic inflammation, probiotic Lactiplantibacillus plantarum, immunology, respiratory system, tight junction, occludin, claudin, zonula occludens

Linking fine root lifespan to root chemical and morphological traits—A global analysis

Fine root lifespan is a critical trait associated with contrasting root strategies of resource acquisition and protection. Yet, its position within the multidimensional "root economics space" synthesizing global root economics strategies is largely uncertain, and it is rarely represented in frameworks integrating plant trait variations. Here, we compiled the most comprehensive dataset of absorptive median root lifespan (MRL) data including 98 observations from 79 woody species using (mini-)rhizotrons across 40 sites and linked MRL to other plant traits to address questions of the regulators of MRL at large spatial scales. We demonstrate that MRL not only decreases with plant investment in root nitrogen (associated with more metabolically active tissues) but also increases with construction of larger diameter roots which is often associated with greater plant reliance on mycorrhizal symbionts. Although theories linking organ structure and function suggest that root traits should play a role in modulating MRL, we found no correlation between root traits associated with structural defense (root tissue density and specific root length) and MRL. Moreover, fine root and leaf lifespan were globally unrelated, except among evergreen species, suggesting contrasting evolutionary selection between leaves and roots facing contrasting environmental influences above vs. belowground. At large geographic scales, MRL was typically longer at sites with lower mean annual temperature and higher mean annual precipitation. Overall, this synthesis uncovered several key ecophysiological covariates and environmental drivers of MRL, highlighting broad avenues for accurate parametrization of global biogeochemical models and the understanding of ecosystem response to global climate change.

Are larger termite mounds more resistant to fire? A study of two southern African termites (Isoptera: Termitidae)

AbstractTermites are resistant to fire, a common disturbance in the world's savannas, but most explanations for how termites resist fire are speculative. Some researchers have suggested that the mounds of some termite species can serve as a structural defence against direct fire mortality. Because mound structure is related to thermoregulation, and larger mounds have more stable internal temperatures, larger mounds may confer greater fire resistance. Fire also causes indirect mortality to termites by removing food sources, which may give an advantage to larger mounds as they have superior food provisioning and storage ability. Using natural fires, we measured mound size and colony survival of two southern African termite species (Trinervitermes trinervoides and Amitermes sp.) in plots recently burnt (<4 months after fire), recovering from fire (1–2 years after fire), or unburnt (>3 years after fire). Burn status and mound size were each significant factors in colony survival. Recent fire was associated with the lowest survival, and larger mounds with greater survival. There is some evidence that larger mounds are generally more resistant to fire, especially the long term, indirect effects, but sample sizes were not adequate to confirm this.

Induced Resistance Mechanism in Plant and Its Importance in Agriculture

The search for a successful and efficient natural phenomenon of induced resistance in plants was prompted by the harmful effects that chemical pesticides and their degradation products had on the environment and human health. Ray was the first to identify plant resistance to diseases in 1901. When arabidopsis plants were injected with the pathogenic bacteria Pseudomonas fluorescens, which colonises roots, induced resistance was initially observed in these plants. There are two different kinds of induced resistance: induced biochemical defense and induced structural defense. Biochemical defense includes phytoalexins, PR-proteins, and secondary metabolites; structural defense includes cytoplasmic reactions, cell wall defense structure, and histological defense structure (development of cork layers, abscission layer, and tylose). Induced systemic resistance (ISR) and systemic acquired resistance (SAR) are the foundation of the induced resistance process. While the defense mechanism in ISR is mediated by jasmonic acid and ethylene and additionally triggered by non-pathognic rhizobacteria (Pseudomonas fluorescens), the defense mechanism in SAR is salicyclic mediated, namely alterations in gene expression. Plants can develop resistance to specific diseases by applying exogenous doses of 2, 6-dichloroisonicotonic acid and benzo-thiadiazole-7-carbothioic acid S-methyl ester (BTH). Induced resistance in plants, while still poorly understood, offers up new possibilities for plant protection and presents a viable strategy for sustainable agriculture and environmentally friendly disease control. It continues to be a problem for both basic and practical research.

Mechanism of Plant Resistance to Insects, Weeds and Pathogens

Plants are primary producers and a food source for many heterotrophic phytophagous organisms. They are affected by different biotic and abiotic environmental stress. Insects, fungi, bacteria, viruses, nematodes, and other pests are biotic factors that significantly reduce crop productivity. Naturally, plants protect themselves from pest attacks by developing different morphological, structural, and biochemical defense mechanisms. However, our understanding of these defensive mechanisms is still limited. Hence, the objective of this paper is to review the mechanism of plant resistance to insects, weeds, and pathogens to know the relevant defense or resistance mechanisms of plants against pests. Many morphological characteristics contribute to plant resistance to insect pests. These include trichomes, surface waxes and hardness of plant tissues, thickening of cell walls and cuticles, the rapid proliferation of tissues, anatomical changes in plant organs, and color and shape of plant parts. The chemical composition of the host plant affects the behavior and adaptation of the herbivore and the host plant. These chemicals can be physiological inhibitors or nutritional deficiencies. Secondary metabolites are compounds that decrease the palatability of the plant tissues in which they are produced but have no effect on a plant's regular growth and development. Plants defend themselves against pathogens by a combination of weapons termed host resistance which is a structural and biochemical defense mechanism and they also defend from weeds by producing allelochemicals. Thus, plants have developed multiple resistance mechanisms to protect against pests. These resistance mechanisms could be an important tool for pest management by reducing the dose of chemicals used in pest control, resulting in a minimal effect of the chemicals on the environment. Also, these resistance mechanisms are compatible with other control methods that act as one of the components of integrated pest management methods to reduce the damage caused by pests.

Combined effect of polystyrene nanoplastic and di-n-butyl phthalate on testicular health of male Swiss albino mice: analysis of sperm-related parameters and potential toxic effects.

Plastics, especially polystyrene nanoplastic particles (PSNPs), are known for their durability and absorption properties, allowing them to interact with environmental pollutants such as di-n-butyl phthalate (DBP). Previous research has highlighted the potential of these particles as carriers for various pollutants, emphasizing the need to understand their environmental impact comprehensively. This study focuses on the subchronic exposure of male Swiss albino mice to PSNP and DBP, aiming to investigate their reproductive toxicity between these pollutants in mammalian models. The primary objective of this study is to examine the reproductive toxicity resulting from simultaneous exposure to PSNP and DBP in male Swiss albino mice. The study aims to analyze sperm parameters, measure antioxidant enzyme activity, and conduct histopathological and morphometric examinations of the testis. By investigating the individual and combined effects of PSNP and DBP, the study seeks to gain insights into their impact on the reproductive profile of male mice, emphasizing potential synergistic interactions between these environmental pollutants. Male Swiss albino mice were subjected to subchronic exposure (60days) of PSNP (0.2mg/m, 50nm size) and DBP (900mg/kg bw), both individually and in combination. Various parameters, including sperm parameters, antioxidant enzyme activity, histopathological changes, and morphometric characteristics of the testis, were evaluated. The Johnsen scoring system and histomorphometric parameters were employed for a comprehensive assessment of spermatogenesis and testicular structure. The study revealed non-lethal effects within the tested doses of PSNP and DBP alone and in combination, showing reductions in body weight gain and testis weight compared to the control. Individual exposures and the combination group exhibited adverse effects on sperm parameters, with the combination exposure demonstrating more severe outcomes. Structural abnormalities, including vascular congestion, Leydig cell hyperplasia, and the extensive congestion in tunica albuginea along with both ST and Leydig cell damage, were observed in the testis, underscoring the reproductive toxicity potential of PSNP and DBP. The Johnsen scoring system and histomorphometric parameters confirmed these findings, providing interconnected results aligning with observed structural abnormalities. The study concludes that simultaneous exposure to PSNP and DBP induces reproductive toxicity in male Swiss albino mice. The combination of these environmental pollutants leads to more severe disruptions in sperm parameters, testicular structure, and antioxidant defense mechanisms compared to individual exposures. The findings emphasize the importance of understanding the interactive mechanisms between different environmental pollutants and their collective impact on male reproductive health. The use of the Johnsen scoring system and histomorphometric parameters provides a comprehensive evaluation of spermatogenesis and testicular structure, contributing valuable insights to the field of environmental toxicology.

Study on structural damage mechanisms and defence of rectangular closed-section simplified hull girders with thinner plates under near-field underwater explosions

Understanding the damage mechanisms of typical ship structures under fatal underwater explosion loads is crucial for developing effective defensive measures. To provide references for enhancing the survivability of ships, this paper conducts analyses of the damage mechanisms of simplified hull girders (SHGs) using a combination of experimental and simulation methods, and proposes targeted structural improvements. Initially, two types of thin-walled rectangular closed-section SHGs are subjected to near-field underwater explosion experiments. Corresponding simulation models are established, and the validity of the computational results is verified. The progressive damage processes of SHGs in hogging and sagging are examined from a structural perspective. Furthermore, the thin-walled plate deformation transfer processes are analyzed. Finally, based on the analyzed damage mechanisms, targeted defensive structures for overall damage are designed. The study results show that enhancing the anti-deformation capability of the upper and lower edges of the side plates can effectively improve the overall bending resistance of the SHG.

Adaptation of an arthropod predator to a challenging environment is associated with a loss of a genome-wide plastic transcriptional response.

Structural and chemical plant defence traits may reduce the efficacy of biological control agents in integrated pest management. Breeding programmes have shown arthropod predators' potential to acclimate to challenging host plants. However, whether and how these predators adapt to novel plant environments remain unclear. Using the predatory mite Phytoseiulus persimilis - herbivorous mite Tetranychus urticae system in an experimental evolution setup, we studied the adaptation mechanisms to tomato and cucumber, plants that possess a distinct repertoire of defensive traits. Experimental evolution experiments on whole plants revealed that allowing P. persimilis to adapt to tomatoes led to an ~100% larger population size. Independent feeding assays showed that tomato- and cucumber-adapted prey reduced predator fecundity. The deleterious effect of ingesting low-quality prey persisted after adaptation of the predator to both cucumber and tomato. We demonstrated that jasmonic acid (JA)-dependent defences reduce prey quality by evaluating predator performance on prey fed on JA defence-deficient tomato plants. Transcriptomic profiling of the replicated P. persimilis lines showed that long-term propagation on tomato and cucumber plants produces distinctive gene-expression levels. Predator adaptation to tomatoes results in the loss of a large transcriptional response, in which predicted cuticle-building rather than detoxification pathways are affected. We showed that the adaptation of predatory arthropods to a novel, challenging plant does not necessarily occur via the prey, but rather through the physical environment of the plant. We provided first insights into the underlying molecular mechanisms. © 2023 Society of Chemical Industry.

Competition reduces structural defense in an invasive thistle in the field

AbstractInvasive thistles reduce the productivity of pastures and rangelands because their structural defenses make them unpalatable to grazing livestock. However, plants potentially alter their growth patterns, including their allocation of resources to defense, in response to the presence of competing vegetation. Understanding the effects of competition on the structural defense of problematic pasture weeds can inform management plans that reduce the economic harm caused by these pests. We grew musk thistle (Carduus nutans L., also commonly called nodding thistle) in a fully crossed factorial field experiment in a single abandoned pasture in 2017 with two experimental factors: the level of thistle infestation (1 thistle or 5, resulting in densities of 4 or 20 plants m−2) and the presence or absence of grazing (simulated by weekly trimming of competing vegetation). We assessed the effects of treatments on defense by counting prickles >3-mm long on leaves. Our analysis included leaf age and leaf size as covariates. Competition reduced the number of prickles present on leaves. Regression analysis showed that an increase from, for example, 50 g to 200 g of competing vegetation within 50 by 50 cm study plots reduced the expected average number of prickles on intermediate-aged leaves with average length 25.5 cm by 76.9 prickles per leaf, or 41%. This pattern was similar for leaves of all ages, although the oldest leaves generally had fewer prickles than younger leaves. We did not observe differences in defense structures between plants neighbored by conspecifics and those neighbored by other competitors. Carduus nutans has been previously managed using high densities of grazers, and this practice may be more likely to damage less-defended individuals such as those we observed in our treatments with competition. This finding suggests that maintaining competition in pastures may increase C. nutans vulnerability to grazing.

The phenylalanine ammonia-lyase inhibitor AIP induces rice defence against the root-knot nematode Meloidogyne graminicola.

The phenylalanine ammonia-lyase (PAL) enzyme catalyses the conversion of l-phenylalanine to trans-cinnamic acid. This conversion is the first step in phenylpropanoid biosynthesis in plants. The phenylpropanoid pathway produces diverse plant metabolites that play essential roles in various processes, including structural support and defence. Previous studies have shown that mutation of the PAL genes enhances disease susceptibility. Here, we investigated the functions of the rice PAL genes using 2-aminoindan-2-phosphonic acid (AIP), a strong competitive inhibitor of PAL enzymes. We show that the application of AIP can significantly reduce the PAL activity of rice crude protein extracts invitro. However, when AIP was applied to intact rice plants, it reduced infection of the root-knot nematode Meloidogyne graminicola. RNA-seq showed that AIP treatment resulted in a rapid but transient upregulation of defence-related genes in roots. Moreover, targeted metabolomics demonstrated higher levels of jasmonates and antimicrobial flavonoids and diterpenoids accumulating after AIP treatment. Furthermore, chemical inhibition of the jasmonate pathway abolished the effect of AIP on nematode infection. Our results show that disturbance of the phenylpropanoid pathway by the PAL inhibitor AIP induces defence in rice against M. graminicola by activating jasmonate-mediated defence.

Melatonin improves the storage quality of rabbiteye blueberry (Vaccinium ashei) by affecting cuticular wax profile

Cuticular wax is the first line of structural defense for plants against external stresses. This study investigated the effects of melatonin (MT) on chemical composition and accumulation profile of wax, as well as fruit quality of rabbiteye blueberry during storage. The results indicated a significant reduction in the overall wax content during storage. Nevertheless, MT effectively delayed the decline, with a higher amount of 9.8% and 15.17% in the treated ‘Baldwin’ and ‘Garden Blue’ compared to their respective controls at 21st day of storage. The wax composition significantly varied depending on storage time, MT treatment, and cultivars. Additionally, MT markedly improved the fruit quality of rabbiteye blueberries. Correlation analysis revealed water loss and decay rates were negatively correlated with triterpenoids and fatty acids. Taken together, this study highlights the positive effects of post-harvest MT application on shelf life and fruit quality of blueberry by modifying the wax profile during storage.

A theoretical model for the oblique impact of fragments

A portion of the casing charge's fragments would strike the target plate and ricochet when it exploded close to or inside a steel structure, like a ship or manufacturing facility. Considering the high pressure, high temperature, and high strain rate during the impact, the kinematic characteristics of the ricochet fragment, such as ricochet velocities and ricochet angle, are challenging to describe using the existing methods. In this study, a novel theoretical model of ricochet fragment kinematics under oblique impact was proposed, and the corresponding initial assumptions and application conditions were presented. A series of oblique impact experiments was conducted to obtain the differences in kinematic characteristics under various impact velocities and impact angles. The parameters of the proposed theoretical model were determined. The accuracy of the theoretical model was verified by using 921A hull steel target plate. The average relative error and standard deviation of ricochet velocity were 7.4 % and 2.3 %, respectively, and the mean relative error and standard deviation of the ricochet angle are 11.2 % and 1.1 %, respectively. The results showed that the theoretical model can predict the ricochet velocity well, and the error of ricochet angle increased due to the different pile-up effect of different strength target plates, but it was still within the reasonable range. In addition, the effects of the impact velocity and angle on the ricochet velocity and angle were analyzed. When the impact angle was small, the ricochet angle and velocity were affected by both impact velocity and angle. When the impact angle increased to a certain Angle (>64.2°), the ricochet velocity only increased linearly with the impact velocity. The ricochet angle increased with the increase in the impact angle. When the impact velocity was less than 400 m/s, the ricochet angle increased with the increase in the impact velocity. When the velocity is greater than 400 m/s, the ricochet angle decreased with the increase in the impact velocity. When the impact angle was greater than 57° and the impact velocity was greater than 400 m/s, the ricochet angle was almost only related to the impact angle. The results indicate that the proposed model has good accuracy and can have high application value in terminal effects, safety engineering, and structural defense fields.

Comparison of feeding preferences of herbivorous fishes and the sea urchin Diadema antillarum in Little Cayman.

On Caribbean coral reefs, losses of two key groups of grazers, herbivorous fishes and Diadema antillarum, coincided with dramatic increases in macroalgae, which have contributed to decreases in the resilience of these coral reefs and continued low coral cover. In some locations, herbivorous reef fishes and D. antillarum populations have begun to recover, and reductions in macroalgal cover and abundance have followed. Harder to determine, and perhaps more important, are the combined grazing effects of herbivorous fishes and D. antillarum on the structure of macroalgal communities. Surprisingly few studies have examined the feeding preferences of D. antillarum for different macroalgal species, and there have been even fewer comparative studies between these different herbivore types. Accordingly, a series of in-situ and ex-situ feeding assays involving herbivorous fishes and D. antillarum were used to examine feeding preferences. Ten macrophytes representing palatable and chemically and/or structurally defended species were used in these assays, including nine macroalgae, and one seagrass. All species were eaten by at least one of the herbivores tested, although consumption varied greatly. All herbivores consumed significant portions of two red algae species while avoiding Halimeda tuna, which has both chemical and structural defenses. Herbivorous fishes mostly avoided chemically defended species while D. antillarum consumed less of the structurally defended algae. These results suggest complementarity and redundancy in feeding by these different types of herbivores indicating the most effective macroalgal control and subsequent restoration of degraded coral reefs may depend on the recovery of both herbivorous fishes and D. antillarum.