Great Variation In Size Research Articles

Sexual dimorphism in the three-dimensional detailed crown structure of maxillary first premolars

Maxillary first premolars have a unique shape because of their curvature features, positional relationship of the cusps, and most prominent points, making them different from other teeth. This study aimed to quantitatively analyze the detailed three-dimensional morphometric structure of maxillary first premolars and sexual dimorphism. The study participants were 60 elementary and junior high school students (30 boys and 30 girls) in Japan. The distance between landmarks was measured using the three-dimensional coordinates of plaster casts, and the data collected was statistically analyzed. Sexual dimorphism was greater in the lingual cusp, showing greater variation in size than the buccal cusp. Boys exhibited significantly larger relative distances in the mesiodistal and buccolingual directions than girls; particularly, regarding mesiodistal diameter of the central groove, mesial slope of the buccal cusp, and distal slope of the lingual cusp. These results may be due to a slight difference in the timing of secondary enamel knots between boys and girls during the developmental stage, which was reflected in the sexual dimorphism of the completed teeth. Curvature features, cusp positions, and most prominent points were considered individual traits because they were not interrelated. Subtle differences during the developmental stage may lead to sexual dimorphism of the completed crown. Furthermore, the morphological characteristics of the maxillary first premolars may be related to their location in the dental arch.

Atomization of Cocoa Honey Using Whey Protein Isolate to Produce a Dry Formulation with Improved Shelf Life for Industrial Application.

Cocoa honey, a by-product obtained during the processing of cocoa, is a juice rich in pectin, organic acids, minerals and phenolic compounds with antioxidant properties. Fresh cocoa honey is quickly fermented due to its high content of reducing sugars, such as fructose and glucose, which limits its shelf life. Currently, cocoa honey is only commercialized in frozen form, as logistical challenges prevent the wide distribution or export of this by-product for applications in the market of sweets, jellies, beverages, confectionery, and nutraceutical foods among others. Spray-drying technology is a viable prospect for the large-scale stabilization of products such as cocoa honey, with less heat exposure compared to other conventional drying methods. This work aimed to evaluate the efficacy of drying adjuvants for a rapid removal of the water present in cocoa honey via atomization, since this process minimizes the effects of glass transition temperature (Tg) related to materials with high sugar contents. Physical parameters such as the moisture content, hygroscopicity, particle size, and yield of the products obtained were determined. Cocoa honey presented 85.3 ± 0.20 g/100 g of moisture. The formulations successfully decreased moisture content, which was lower than 11.72 ± 0.08 g/100 g in the formulations. Water activity ranged between 0.1464 ± 0.0043 and 0.1562 ± 0.029, with no significant difference between the formulations. The hygroscopicity of cocoa honey powders ranged from 29.29 to 29.87 g of water/100 g of cocoa honey. The combination of 20% maltodextrin and 1% whey protein isolate (WPI) led to the best yield, resulting in a free-flowing powder as the final product. On the other hand, the formulation composed of maltodextrin and whey protein isolate in the ratio of 29:1, respectively, led to the most stable product, with less loss of phenolic compounds during the drying process (6.04%). Regarding particle diameter, 90% of the accumulated distribution did not exceed 57 μm. The greatest dispersion of particles occurs in the Ma20W10 formulation with a span of 2.72, inferring greater variation in size between small (7.01 ± 0.06 μm), medium (18.25 ± 0.37 μm), and large (56.65 ± 1.17 μm) particles. The use of whey protein isolate as an adjuvant proved to be an efficient drying process in the production of cocoa honey powder, and was also advantageous for enriching the nutritional content of the final product due to its protein origin. Furthermore, the combination of spray-drying technology and the use of whey protein isolate as adjuvant led to a free-flowing cocoa honey powder with an adequate particle size and benefits in terms of shelf-life extension, providing new opportunities for the commercialization of cocoa honey as an ingredient for the food industry, with benefits for the circular economy.

Distinct Cholesterol Localization in Glioblastoma Multiforme Revealed by Mass Spectrometry Imaging.

Glioblastoma multiforme (GBM) is the most common and aggressive brain tumor in adults and is highly resistant to chemo- and radiotherapies. GBM has been associated with alterations in lipid contents, but lipid metabolism reprogramming in tumor cells is not fully elucidated. One of the key hurdles is to localize the lipid species that are correlated with tumor growth and invasion. A better understanding of the localization of abnormal lipid metabolism and its vulnerabilities may open up to novel therapeutic approaches. Here, we use time-of-flight secondary ion mass spectrometry (ToF-SIMS) to spatially probe the lipid composition in a GBM biopsy from two regions with different histopathologies: one region with most cells of uniform size and shape, the homogeneous part, and the other with cells showing a great variation in size and shape, the heterogeneous part. Our results reveal elevated levels of cholesterol, diacylglycerols, and some phosphatidylethanolamine in the homogeneous part, while the heterogeneous part was dominated by a variety of fatty acids, phosphatidylcholine, and phosphatidylinositol species. We also observed a high expression of cholesterol in the homogeneous tumor region to be associated with large cells but not with macrophages. Our findings suggest that ToF-SIMS can distinguish in lipid distribution between parts within a human GBM tumor, which can be linked to different molecular mechanisms.

Properties of Pinus sp. pellets prepared after in-line pre-compaction with torrefaction

Pelletizing and torrefaction increase biomass energy density, generating a more homogeneous fuel with lower moisture, enabling it to burn in equipment with high energy efficiency. This work evaluated the quality of pellets made from wood particles that had been densified and torrefied in an extruder-type system. Particles of the Pinus sp. wood were torrefied at 200, 250, and 300 °C for six minutes and then compacted to produce pellets. The physical, chemical, and mechanical properties of these pellets were evaluated and compared with standard ones. Torrefaction modified the pellets properties by increasing ash, fixed carbon, higher heating value, and the energy density, while reducing the volatile matter and equilibrium moisture content. The mechanical durability of the pellets was lower than that defined by the European, German, and American standards. The torrefaction pre-compaction route with torrefied particles at a temperature of 300 °C was the most efficient for energetic use, compared to the in natura biomass. The latter has negative aspects such as great variation in size (length and diameter) and density besides high moisture content.

Left Anterior Descending Coronary Artery Ligation for Ischemia-reperfusion Research: Model Improvement via Technical Modifications and Quality Control.

Coronary heart disease is the leading cause of death globally. Complete cessation of blood flow in coronary arteries causes ST-segment elevation myocardial infarction (STEMI), resulting in cardiogenic shock and fatal arrhythmia, which are associated with high mortality. Primary coronary intervention (PCI) for recanalizing the coronary artery significantly improves the outcomes of STEMI, but advancements made in shortening the door-to-balloon time have failed to reduce in-hospital mortality, suggesting that additional therapeutic strategies are required. Left anterior descending coronary artery (LAD) ligation in rats is an animal model for acute myocardial IR research that is comparable to the clinical scenario in which rapid coronary recanalization through PCI is used for STEMI; however, PCI-induced STEMI is a technically challenging and complicated operation associated with high mortality and great variation in infarction size. We identified the ideal position for LAD ligation, created a gadget to control a snare loop, and supported a modified surgical maneuver, thereby reducing tissue damage, to establish a reliable and reproducible acute myocardial ischemia-reperfusion (IR) research protocol for rats. We also propose a method for validating the quality of study results, which is a critical step for determining the accuracy of subsequent biochemical analyses.

Acorn production of introduced Quercus rubra is more strongly impacted by the weather than by the forest site (a case study from Poland)

Recognition of the seed crop size and the periodicity of abundant seed production is essential for the management and control of introduced tree species. Here we studied acorn production of the North American northern red oak, Quercus rubra – the most common commercially important and invasive alien tree in European forests. A four-year (2017-2020) study conducted in even-aged Q. rubra stands, planted 55-60 years ago in sites of coniferous, mixed, and deciduous forests in central Poland, revealed a great variation in size of premature and mature acorn yields both among stands within the same year and among years for the same stand. However, each year numerous acorns of the introduced oak entered existing ecosystems, and the supply of mature propagules was more stable in the studied forests than in the Q. rubra native range. The total acorn crop was correlated significantly with the forest site, however, the forest site had a weaker effect on Q. rubra masting than the weather. Increases in abortion of acorns and decreases in mature acorn crops were preceded by reproduction-inhibiting weather events, and lower crops of mature acorns were correlated with abundant premature acorn abscission. In reaction to the weather, the phenology of premature and mature acorn shedding was very variable in subsequent years, but it was synchronized in time among all forest sites studied. The size of seed crop at the stand level was shaped by acorn crops of the highly-productive trees, and their identification within stands can be crucial for both effective management and control of Q. rubra in European forests.

Sugar Content and Warning Criteria Evaluation for Popular Sugar-Sweetened Beverages in Taipei, Taiwan.

Sugar intake may increase the risk of obesity, cardiovascular disease, diabetes, and dental caries. In Taiwan, people frequently consume sugar-sweetened beverages (SSBs). This study explored the energy and sugar content of Taiwanese SSBs and evaluated them using the Chilean warning label system (>70 kcal/100 mL and >5 g sugar/100 mL) and the World Health Organization (WHO) sugar guideline (≤25 g sugar). A total of 341 SSBs with volumes ≤600 mL were analyzed. No significant differences were observed in sugar per serving among different types of SSBs, but a great variation in portion size (i.e., package size for individual consumption) was noted. The energy and sugar ratios per serving were lower in soft drinks and coffee and tea containing >1 serving than in those containing only one serving. The calorie and sugar ratios per portion were higher in all types of SSBs containing >1 serving per portion than in those containing exactly one serving. Approximately 70.0% of Taiwanese SSBs were classified as high sugar according to the Chilean criteria, and 41.6% of SSBs exceeded the WHO guideline. Moreover, 40.8% of SSBs that were not considered as high sugar according to the Chilean criteria contained >25 g sugar per portion. For individual consumption, it is more clear that nutrition labeling is based on portion rather than serving. Evaluating SSBs on sugar/portion rather than sugar/100 mL will help consumers make better choices.

Thermal behavior evaluation of benzoxazine reinforced withmacadamiabiomass composites

AbstractRecently, to improve the properties, reduce the amount of polymeric materials, the time of disposal in landfills and the cost of composite parts, the incorporation of vegetal biomass was considered. In this study, composites with 10% and 20% v/v of benzoxazine resins and macadamia nutshell (50#) were made via hand layup within naturabiomass and hydrothermally treated (121°C/45 min in an autoclave). Thermogravimetry indicates that the initial temperature of biomass degradation (209°C) allows it to be used with the resin (oven curing at 190°C). The enthalpies obtained from the DSC indicate that the percentage of cure increased with the biomass. FT‐IR tests indicate that the hydrothermal treatment collapsed part of the lignin and extracted lignocellulosic material. There was no significant modification of the glass transition temperature obtained in DMA and TMA with the introduction of biomass. Optical microscopy showed that the treated reinforcement showed a greater variation in size forming lumps. Based on these results, these composites can be used in the replacement of synthetic composites, contributing to a decrease in the consumption of petroleum derivatives and with this, reducing the disposal in landfills and dumps.

The size and shape of parasitic larvae of naiads (Unionidae) are not dependent on female size

The naiads, large freshwater mussels (Unionida), have very long life spans, are large-bodied, and produce thousands to millions of larvae (glochidia) which typically must attach to host fish tissues to metamorphose into a juvenile mussel. Glochidia develop within a female's marsupial gill demibranch, thus their number is restricted by female size. However, larger mussels acquire more energy, which could be invested in either larger-sized glochidia, in a more glochidia, or a combination of both. The high level of host specialization seen in many naiads may constrain glochidial size and shape around a narrow optimum, while naiads that use a wide range of host fishes may be predicted to possess greater plasticity in glochidial morphology. In this paper, we investigated the relationship between maternal body size and progeny body size and shape, aided by modern digital microscopy. We analyzed the between- and within- species variation of glochidia size and shape relative to female size in four widespread species of European naiads: Anodonta anatina, Anodonta cygnea, Unio crassus and Unio tumidus. Whereas the total reproductive output is collinear with female body size, substantial differences between species in glochidia size were found within genus Anodonta, but not genus Unio where glochidial size is remarkably consistent. The glochidial shape, however, differed within both Unio and Anodonta. We interpret this constant within-species glochidial size in Unio as reflecting a constraint imposed by the likelihood of successful transmission onto and off from a narrow range of hosts, whereas their shape seems to be less constrained. The Anodonta species, inhabiting a wide spectrum of habitats and using more than twice the number of fish hosts than Unio spp., have larger glochidia with greater variation in size and shape. Our results suggest that measures of glochidial variability may also serve as an indicator of host specificity in other naiads.

Urban Squares in Late Bronze Age Ugarit: a Street View on Ancient Near Eastern Governance

Urban Squares in Late Bronze Age Ugarit: a Street View on Ancient Near Eastern Governance

Investigation of the activity of transposable elements and genes involved in their silencing in the newt Cynops orientalis, a species with a giant genome

Caudata is an order of amphibians with great variation in genome size, which can reach enormous dimensions in salamanders. In this work, we analysed the activity of transposable elements (TEs) in the transcriptomes obtained from female and male gonads of the Chinese fire-bellied newt, Cynops orientalis, a species with a genome about 12-fold larger than the human genome. We also compared these data with genomes of two basal sarcopterygians, coelacanth and lungfish. In the newt our findings highlighted a major impact of non-LTR retroelements and a greater total TE activity compared to the lungfish Protopterus annectens, an organism also characterized by a giant genome. This difference in TE activity might be due to the presence of young copies in newt in agreement also with the increase in the genome size, an event that occurred independently and later than lungfish. Moreover, the activity of 33 target genes encoding proteins involved in the TE host silencing mechanisms, such as Ago/Piwi and NuRD complex, was evaluated and compared between the three species analysed. These data revealed high transcriptional levels of the target genes in both newt and lungfish and confirmed the activity of NuRD complex genes in adults. Finally, phylogenetic analyses performed on PRDM9 and TRIM28 allowed increasing knowledge about the evolution of these two key genes of the NuRD complex silencing mechanism in vertebrates. Our results confirmed that the gigantism of the newt genomes may be attributed to the activity and accumulation of TEs.

Genomic insights into body size evolution in Carnivora support Peto\u2019s paradox

BackgroundThe range of body sizes in Carnivora is unparalleled in any other mammalian order—the heaviest species is 130,000 times heavier than the lightest and the longest species is 50 times longer than the shortest. However, the molecular mechanisms underlying these huge differences in body size have not been explored.ResultsHerein, we performed a comparative genomics analysis of 20 carnivores to explore the evolutionary basis of the order’s great variations in body size. Phylogenetic generalized least squares (PGLS) revealed that 337 genes were significantly related to both head body length and body mass; these genes were defined as body size associated genes (BSAGs). Fourteen positively-related BSAGs were found to be associated with obesity, and three of these were under rapid evolution in the extremely large carnivores, suggesting that these obesity-related BSAGs might have driven the body size expansion in carnivores. Interestingly, 100 BSAGs were statistically significantly enriched in cancer control in carnivores, and 15 of which were found to be under rapid evolution in extremely large carnivores. These results suggested that large carnivores might have evolved an effective mechanism to resist cancer, which could be regarded as molecular evidence to support Peto’s paradox. For small carnivores, we identified 15 rapidly evolving genes and found six genes with fixed amino acid changes that were reported to reduce body size.ConclusionsThis study brings new insights into the molecular mechanisms that drove the diversifying evolution of body size in carnivores, and provides new target genes for exploring the mysteries of body size evolution in mammals.

A Study on Surgical Implications and Variations of Suprameatal Spine and Other Landmarks on the Lateral Surface of Temporal Bone.

Mastoidectomy forms the main surgical procedure for eradication of disease in chronic otitis media. Such a surgery which contemplates a complete exenteration of all the tympano-mastoid cavities is rightly considered as a difficult one mainly because a large number of vitally important structures are crowded together in the small field of operation and there is always a risk of damaging them. It is therefore, extremely important that the otologist who would undertake this surgery be thorough with the details of the surgical relations of this region. Out of the various structures seen on the lateral surface of temporal bone one very important structure is the suprameatal spine. It is shown to have great variations in shape and size and has been a mystery to researchers due to the implications it is known to have on mastoid region anatomy. In this study we have evaluated the various types of suprameatal spine, prevalence of each type and the effect of each to other landmarks encountered during surgery and also the effect of mastoid pneumatisation on the same.

Coexistent Heteroblastic Needles of Adult Pinus canariensis C.Sm. ex DC. in Buch Trees Differ Structurally and Physiologically

Great variation in shape and size between primary (juvenile) and secondary (adult) needles, so-called leaf-heteroblasty, occurs in several Pinus species. Most of them loss primary needles during the juvenile-to-adult transition of the tree. An exception to this is Pinus canariensis (a Canary Islands endemism) in which basal resprouting twigs of adult trees frequently wear both primary and secondary needles. Taking advantage of this extraordinary study-case-species, we conducted an exhaustive comparison of both needle types through quantitative analyses of needle anatomy, photochemical performance, gas exchange, and resistance to extreme dehydration and to extreme needle temperature. We hypothesized that primary needles would show lower investment to leaf structure but higher photosynthetical efficiency. Primary needles had less stomatal density and thicker and less wettable cuticles. In cross section, primary needles showed smaller structural fraction (e.g., percent of hypodermis, endodermis and vascular tissue) and higher fraction of photosynthetic parenchyma. Significant differences between primary and secondary needles were not found in net carbon assimilation not in their leaf mass area values. Interestingly, secondary needles showed higher electron transport rate, and they were additionally much more efficient in retaining water under severe and controlled desiccant conditions. When subjected to extreme temperatures (−10° to +50 °C), primary needles recovered better their photochemical efficiency than secondary needles, after +46° and +48 °C heat-shock treatments. Our results indicate that both needle types broaden the diversity of physiological responses against environmental constrains in basal twigs of adult P. canariensis trees. Considering that this is a fire-resistant and resprouting species, this advantage could be particularly useful after a drastic environmental change such a fire or a gap opening in the forest.

Paediatric Diagnostic Reference levels in low Resource Settings: A Guide for developing Country Practitioners with excerpts from ICRP 135

Background: The practical implementation of Diagnostic Reference Level in pediatric imaging is a complex task due to their unique individuality in terms of high sensitivity to radiation, varying body sizes and presenting pathology. Hence, good knowledge of medical technology, skill to perform patient dosimetry and to analyze mage quality is required.
 Purpose: To provide a guide on the methodological requirements for the establishment of Paediatric Diagnostic Reference Levels (PiDRLs) based on the revised and updated guidelines from the current ICRP publication 135 on Diagnostic Reference Levels (DRLs).
 Materials and method: An extensive review of the ICRP report Publication 135 on Diagnostic Reference levels in medical imaging with a focus on paediatric imaging and other related studies were undertaken. 
 Results: The ICRP report 135 updates and refines the recommendations of 2001. It highlights that the application of DRLs in paediatrics alone is not sufficient for the optimization of protection. Image quality must be evaluated. Quantities used for DRLs should be appropriate to the imaging modality being evaluated, assess the amount of ionizing radiation applied to perform a medical imaging task, and be measured directly. For interventional procedures, the complexity of the procedure may be considered in setting DRLs. DRLs shall not be used for individual patients or as trigger (alert or alarm) levels for individual patients. Appropriate weight bands (generally with 5 or 10 kg intervals) are recommended for establishing paediatric DRLs and should be promoted.
 Conclusion: The amount of radiation used for examinations of children can vary tremendously due to the great variation in patient size and weight from neonates to adult-sized adolescents. This variation in patient radiation dose is appropriate. However, variation in patient doses due to inappropriate technique or failure to child-size the imaging protocol is not appropriate. This forms the basis of the new ICRP guideline and should form the basis of developing PiDRLs.

Relationships Stretched Thin: Social Support Mobilization in Poverty

Research on how the poor “make ends meet” typically shows that they are able to do so by relying on dense support networks of family and close friends. Recent research suggests, however, that these networks play a limited role. This article examines the role of informal networks in how sixty-one households in Barcelona, Spain, cope with poverty. We use a mixed-methods design that combines structured network delineation with semistructured interviews about the processes of support mobilization. Findings show a great variation in network size and resource capacity among households and in the kinds of ties that offer support. Social support was regarded as essential among members of poor households, but mobilized networks were often insufficient for covering even the most basic needs, and prolonged network mobilization could cause strain and long-term conflict. This analysis suggests that support networks may help people to cope with income volatility while simultaneously increasing the potential for social exclusion and isolation.

Free-Hand Cervical Pedicle Screw Placement by Using Para-articular Minilaminotomy: Its Feasibility and Novice Neurosurgeons' Experience.

Study Design.:Retrospective study.Objective.:Cervical pedicle screw (CPS) placement is technically demanding because of the great variation in pedicle size, dimension, and angulations between cervical levels and patients and the lack of anatomical landmarks. This retrospective study was conducted to analyze novice neurosurgeons’ experience of CPS placement by using the technique with direct exposure of pedicle via para-articular minilaminotomy.Methods.:We retrospectively reviewed 78 CPSs in 22 consecutive patients performed by 2 surgeons. All pedicle screws were inserted under the direct visualization of the pedicle by using para-articular minilaminotomy without any fluoroscopic guidance. We analyzed the direction and grade of pedicle perforation on the postoperative computed tomography scan. The degree of perforation was classified as grade 0 to 3. Grades 0 and 1 were classified as the correct position and the others, as the incorrect position.Results.:In total, the correct position (grade 0 and 1) was found in 72 (92.3%) screws and the incorrect position (grade 2 and 3) in 6 (7.7%). Among the 16 pedicle perforations (grade 1, 2, and 3 perforations), the directions were lateral in 15 (93.8%) and superior in 1 (6.2%). There were no neurovascular complications related to CPS insertion.Conclusion.:Free-hand CPS placement by using para-articular minilaminotomy seems to be feasible and reproducible.

Paediatric Diagnostic Reference levels in low Resource Settings: A Guide for Developing Country Practitioners with excerpts from ICRP

Background: The practical implementation of Diagnostic Reference Level in paediatric imaging is a complex task due to their unique individuality in terms of high sensitivity to radiation, varying body sizes and presenting pathology. Hence, good knowledge of medical technology, skill to perform patient dosimetry and to analyze mage quality is required. Purpose: To provide a guide on the methodological requirements for the establishment of Paediatric Diagnostic Reference Levels (PiDRLs) based on the revised and updated guidelines from the current ICRP publication 135 on Diagnostic Reference Levels (DRLs). Materials and method: An extensive review of the ICRP report Publication 135 on Diagnostic Reference levels in medical imaging with a focus on paediatric imaging and other related studies were undertaken. Results: The ICRP report 135 updates and refines the recommendations of 2001. It highlights that the application of DRLs in paediatrics alone is not sufficient for the optimization of protection. Image quality must be evaluated. Quantities used for DRLs should be appropriate to the imaging modality being evaluated, assess the amount of ionizing radiation applied to perform a medical imaging task, and be measured directly. For interventional procedures, the complexity of the procedure may be considered in setting DRLs. DRLs shall not be used for individual patients or as trigger (alert or alarm) levels for individual patients. Appropriate weight bands (generally with 5 or 10 kg intervals) are recommended for establishing paediatric DRLs and should be promoted. Conclusion: The amount of radiation used for examinations of children can vary tremendously due to great variation in patient size and weight from neonates to adult-sized adolescents. This variation in patient radiation dose is appropriate. However, variation in patient doses due to inappropriate technique or failure to child-size the imaging protocol is not appropriate. This forms the basis of the new ICRP guideline and should form the basis of developing PiDRLs.

Two - stages bloom of Margalefidinium cf. polykrikoides in a Mediterranean shallow bay (Ionian Sea, Italy)

The emergence of a red tide resulting in yellow-brownish discoloration of waters in Porto Cesareo bay (Italy) during July–August 2018 is reported. The species responsible for the bloom was the dinoflagellate Margalefidinium cf. polykrikoides. Cell densities reached 9.1 × 106 cells L−1 during the initial outbreak. A second peak was observed about three weeks later reaching 6.7 × 105 cells L−1. Study of live specimens showed great variation in cell size and shape. Different cyst morphotypes were found in the water samples and in the sediment. For the first time, we followed several stages of the life cycle of M. cf. polykrikoides in natural samples. Fish die-offs in the bay were not observed, however this high-density bloom may have caused consequences on the ecosystem (amount of mucilage on the beach) and in turn, on tourism that is the main activity in the area during the summer season.

Allometry and morphological trait relationship in the sexually dimorphic Chinese dobsonfly, Acanthacorydalisasiatica (Wood-Mason, 1884) (Megaloptera, Corydalidae).

Male insects with large weapons such as horns and elongate mandibles would be expected to invest more on such structures than other parts of the body for advantages in male to male competition for mating. In male genitalia, however, intermediate size provides a better fit for more females than small or large sizes, and such a male would leave more offspring regardless of their body size. These predictions were tested using a static allometry analysis between body size and other trait sizes. Acanthacorydalisasiatica is a large dobsonfly (Megalotera) and males have conspicuously large mandibles used as weapons. We examined the hypothesis that the male mandibles of this sexually dimorphic species are sexually selected to enlarge, whereas the male genitalia are stable to be intermediate regardless of a great variation in body size. The results, as predicted, showed positive allometry between male body size and mandible length but negative allometry between male body size and ectoproct length (a male grasping structure). Sperm are transferred through a small spermatophore attached externally to the female genital opening, so it may be evolutionarily unnecessary to develop an enlarged male genital size. In contrast, there may be a trade-off between male mandible size and wing length, because of negative allometry between body size and wing length in males but isometry between them in females.