Extreme Elongation Research Articles

The Cervical Osteology of Okapia johnstoni and Giraffa camelopardalis.

Giraffidae is the only family of ruminants that is represented by two extant species; Okapia johnstoni and Giraffa camelopardalis. Of these taxa, O. johnstoni represents a typical short-necked ungulate, and G. camelopardalis exemplifies the most extreme cervical elongation seen in any ruminant. We utilize these two species to provide a comprehensive anatomic description of the cervical vertebrae. In addition, we compare the serial morphologic characteristics of the okapi and giraffe cervical vertebrae, and report on several osteologic differences seen between the two taxa. The giraffe neck appears to exhibit homogenization of C3-C7; the position of the dorsal tubercle, thickness of the cranial articular process, shape of the ventral vertebral body, and orientation of the ventral tubercle are constant throughout these vertebrae, whereas these features are serially variable in the okapi. We also report on several specializations of the giraffe C7, which we believe relates to an atypical cervico-thoracic junction, corresponding to the substantial neck lengthening. The morphologic differences exhibited between the okapi and giraffe cervical vertebrae have implications on the function of the necks relating to both fighting and feeding.

Microaxicon-generated photonic nanojets

We report on the calculations of optical radiation scattering at micrometer-sized conical-shape dielectric particles (microaxicons) with special attention given to the specific spatially localized near-field area constituting a photonic nanojet (PNJ). By virtue of finite-difference time-domain simulations we show for the first time, to the best our knowledge, that the PNJ produced by a microaxicon of specific spatial orientation can exhibit extreme axial elongation up to ∼25λ (at defined intensity level) while retaining high peak intensity and subwavelength transverse width.

Ground-state and rotational properties of a two-component Bose–Einstein condensate in a harmonic plus quartic trap

We consider a two-component Bose–Einstein condensate under extreme elongation in a harmonic plus quartic trap. The ground-state and rotational properties of such a system are numerically studied as a function of intra- and inter-component contact interactions, and of the rotational frequency. For the nonrotational case, we obtain the exact phase diagram showing the ground-state density distributions as contact-interactions varied. For both slowly and ultrarapidly rotational cases, we demonstrate that the vortex configurations depend strongly on the relative strength of the contact interactions, as well as on the rotational frequency. The controllable system may be used to investigate the interplay of interaction and rotation, and to explore more exotic quantum phases.

Metabolomic and transcriptomic insights into how cotton fiber transitions to secondary wall synthesis, represses lignification, and prolongs elongation.

BackgroundThe morphogenesis of single-celled cotton fiber includes extreme elongation and staged cell wall differentiation. Designing strategies for improving cotton fiber for textiles and other uses relies on uncovering the related regulatory mechanisms. In this research we compared the transcriptomes and metabolomes of two Gossypium genotypes, Gossypium barbadense cv Phytogen 800 and G. hirsutum cv Deltapine 90. When grown in parallel, the two types of fiber developed similarly except for prolonged fiber elongation in the G. barbadense cultivar. The data were collected from isolated fibers between 10 to 28 days post anthesis (DPA) representing: primary wall synthesis to support elongation; transitional cell wall remodeling; and secondary wall cellulose synthesis, which was accompanied by continuing elongation only in G. barbadense fiber.ResultsOf 206 identified fiber metabolites, 205 were held in common between the two genotypes. Approximately 38,000 transcripts were expressed in the fiber of each genotype, and these were mapped to the reference set and interpreted by homology to known genes. The developmental changes in the transcriptomes and the metabolomes were compared within and across genotypes with several novel implications. Transitional cell wall remodeling is a distinct stable developmental stage lasting at least four days (18 to 21 DPA). Expression of selected cell wall related transcripts was similar between genotypes, but cellulose synthase gene expression patterns were more complex than expected. Lignification was transcriptionally repressed in both genotypes. Oxidative stress was lower in the fiber of G. barbadense cv Phytogen 800 as compared to G. hirsutum cv Deltapine 90. Correspondingly, the G. barbadense cultivar had enhanced capacity for management of reactive oxygen species during its prolonged elongation period, as indicated by a 138-fold increase in ascorbate concentration at 28 DPA.ConclusionsThe parallel data on deep-sequencing transcriptomics and non-targeted metabolomics for two genotypes of single-celled cotton fiber showed that a discrete developmental stage of transitional cell wall remodeling occurs before secondary wall cellulose synthesis begins. The data showed how lignification can be transcriptionally repressed during secondary cell wall synthesis, and they implicated enhanced capacity to manage reactive oxygen species through the ascorbate-glutathione cycle as a positive contributor to fiber length.Electronic supplementary materialThe online version of this article (doi:10.1186/s12864-015-1708-9) contains supplementary material, which is available to authorized users.

Interspinous Device Implant and Sopraspinous Ligament Removal: An Alternative Approach for Low Back Pain Syndrome Persistence: Our Experience after 2 Years

Introduction Low-back pain syndrome is, up to date, one of the most common cause of inability, especially for young-adult people. In 20% of cases, patients have a degenerative disc disease associated with radiculopathy due to neuroforamen diameter reduction and lumbar soft-stenosis. Interspinous devices were extensively used in the treatment of this pathology, with different outcomes. Material and Methods An observational study was conducted comparing the interspinous device implant only, according to the standard technique, versus the devices implant together with a supraspinous ligament removal. Since April 2012, 81 patients with low-back pain and foraminal “soft” stenosis were enrolled and divided into two groups, homogeneous for age, sex, and disease severity (clinically and instrumentally assessed). Before surgery, all patients were subjected to medical therapy for at least 6 months without any clinical benefit. A total of 39 patients (group A, control) underwent interspinous devices implant only, according to the standard technique and 42 patients (group B) underwent device implant and supraspinous ligament removal. A clinical follow-up was performed at month 1, 3, 6, 12, and 24 by mean of visual analog scale (VAS), neurogenic claudication outcome score (NCOS), and Oswestry low back pain disability questionnaire (OLBPDQ). A radiographic control was obtained at month 1 and 6 (dynamic radiographic studies included). A MRI was done at month 6. The data were analyzed by mean of the Kaplan–Meier curve (results yielding a p value < 0.05 were considered statistically significant). Results Until month 12, slight differences in VAS, NCOS, and OLBPDQ values were noticed between the two groups, but these scores was significantly higher in group B at month 24. Furthermore, radiographic evaluation showed a more significant neural foramina height recovery (mean value: 23 ± 3% vs. 41 ± 3%, respectively, in groups A and B). Although the supraspinous ligament is removed, there is not iatrogenic instability risk, because the device produces an immediate mechanical stability and a consequent intervertebral fusion. At follow-up there were no “fixation failure” and none patient underwent revision surgery. The standard technique provides the intraspinous ligament incision only and the devices positioning in the space between the spinous processes. In our opinion, this approach represents only a partial approach. Although the device implant is useful for radiculopathy resolution, usually low back could decrease, but in many cases only at the beginning. In fact the device may produce a supraspinous ligament extreme elongation, through to the intervertebral distraction. The nociceptors are abnormally stimulated and the back pain can reappear or in some cases persist. Conclusion This approach is able to definitively resolve both radiculopathy and low-back pain. This is an effective technique in terms of safety and efficacy, capable to provide a structural and functional correction, without back pain persistence risk, due to supraspinous ligament extreme elongation.

Feeding in billfishes: inferring the role of the rostrum from a biomechanical standpoint.

Perhaps the most striking feature of billfishes is the extreme elongation of the premaxillary bones forming their rostra. Surprisingly, the exact role of this structure in feeding is still controversial. The goal of this study is to investigate the use of the rostrum from a functional, biomechanical and morphological standpoint to ultimately infer its possible role during feeding. Using beam theory, experimental and theoretical loading tests were performed on the rostra from two morphologically different billfish, the blue marlin (Makaira nigricans) and the swordfish (Xiphias gladius). Two loading regimes were applied (dorsoventral and lateral) to simulate possible striking behaviors. Histological samples and material properties of the rostra were obtained along their lengths to further characterize structure and mechanical performance. Intraspecific results show similar stress distributions for most regions of the rostra, suggesting that this structure may be designed to withstand continuous loadings with no particular region of stress concentration. Although material stiffness increased distally, flexural stiffness increased proximally owing to higher second moment of area. The blue marlin rostrum was stiffer and resisted considerably higher loads for both loading planes compared with that of the swordfish. However, when a continuous load along the rostrum was considered, simulating the rostrum swinging through the water, swordfish exhibited lower stress and drag during lateral loading. Our combined results suggest that the swordfish rostrum is suited for lateral swiping to incapacitate their prey, whereas the blue marlin rostrum is better suited to strike prey from a wider variety of directions.

The cranial anatomy of the neornithischian dinosaur Thescelosaurus neglectus.

Though the dinosaur Thescelosaurus neglectus was first described in 1913 and is known from the relatively fossiliferous Lance and Hell Creek formations in the Western Interior Basin of North America, the cranial anatomy of this species remains poorly understood. The only cranial material confidently referred to this species are three fragmentary bones preserved with the paratype, hindering attempts to understand the systematic relationships of this taxon within Neornithischia. Here the cranial anatomy of T. neglectus is fully described for the first time based on two specimens that include well-preserved cranial material (NCSM 15728 and TLAM.BA.2014.027.0001). Visual inspection of exposed cranial elements of these specimens is supplemented by detailed CT data from NCSM 15728 that enabled the examination of otherwise unexposed surfaces, facilitating a complete description of the cranial anatomy of this species. The skull of T. neglectus displays a unique combination of plesiomorphic and apomorphic traits. The premaxillary and ‘cheek’ tooth morphologies are relatively derived, though less so than the condition seen in basal iguanodontians, suggesting that the high tooth count present in the premaxillae, maxillae, and dentaries may be related to the extreme elongation of the skull of this species rather than a retention of the plesiomorphic condition. The morphology of the braincase most closely resembles the iguanodontians Dryosaurus and Dysalotosaurus, especially with regard to the morphology of the prootic. One autapomorphic feature is recognized for the first time, along with several additional cranial features that differentiate this species from the closely related and contemporaneous Thescelosaurus assiniboiensis. Published phylogenetic hypotheses of neornithischian dinosaur relationships often differ in the placement of the North American taxon Parksosaurus, with some recovering a close relationship with Thescelosaurus and others with the South American taxon Gasparinisaura, but never both at the same time. The new morphological observations presented herein, combined with re-examination of the holotype of Parksosaurus, suggest that Parksosaurus shares a closer relationship with Thescelosaurus than with Gasparinisaura, and that many of the features previously cited to support a relationship with the latter taxon are either also present in Thescelosaurus, are artifacts of preservation, or are the result of incomplete preparation and inaccurate interpretation of specimens. Additionally, the overall morphology of the skull and lower jaws of both Thescelosaurus and Parksosaurus also closely resemble the Asian taxa Changchunsaurus and Haya, though the interrelationships of these taxa have yet to be tested in a phylogenetic analysis that includes these new morphological data for T. neglectus.

Male‐biased sexual size dimorphism and sex ratio in the New Zealand Giraffe Weevil, Lasiorhynchus barbicornis (Fabricius, 1775) (Coleoptera: Brentidae)

AbstractBoth the sex ratio and the extent of sexual size dimorphism (SSD) can have important implications for the mating system of a species. In particular, the sex that is limited (generally the female) is often the subject of intense competition, which can drive changes in behaviour and morphology to increase the competitive ability of the more abundant sex. The New Zealand giraffe weevil, Lasiorhynchus barbicornis (Fabricius, 1775), is a large and charismatic species found across much of New Zealand, but very little is known about its natural history. We determined the population structure and ecology of L. barbicornis from a single wild population over 3 years. L. barbicornis was found to be highly abundant in the warmer months, between November and May, but showed a peak in abundance in February and March in each year. The sex ratio was consistently male‐biased throughout the breeding season (mean sex ratio between seasons 0.59 ± 0.02). Univariate and multivariate analyses showed that L. barbicornis is highly sexually size‐dimorphic mostly because of the extreme elongation of the rostrum of the male. All body parts of the males were also found to be more variable in size than those of the females, particularly head length, as shown by higher coefficients of variation. There was, however, no significant seasonal variation in SSD. These data are crucial to gain an understanding of the ecology and of factors driving the mating system in this species. The male‐biased sex ratio and SSD are key components of L. barbicornis ecology and are likely to have driven the highly competitive, defence‐based mating system observed.

Parallel evolution of novelties: extremely long intromittent organs in the leaf beetle subfamily Criocerinae

Extreme elongation of a part of the intromittent organ, the flagellum, has occurred several times in Criocerinae (Chrysomelidae). These leaf beetles have acquired a specialized pocket to store the flagellum in the abdominal cavity, at the same time allowing a quick control of movements of this structure during copulation. We investigated the morphogenesis of the intromittent organs of species with and without a flagellum to discuss the evolutionary background of parallel evolution of novel structures. We found that the specialized pocket is formed by the invagination of an epidermal layer and a resultant rotation of the primary gonopore. Invagination itself is a well-known phenomenon in morphogenetic processes, which leads us to hypothesize that the novelty is formed by co-opting a previously acquired genetic system. A large open-space is present within the intromittent organ during the entire morphogenesis in species without a flagellum, and the invagination in the species with a flagellum grows in the corresponding area. This means that there are no physical impediments for the growth of a large pocket. In addition the sites of muscular attachments in the species with a flagellum are also different from those without it. The differentiation of muscles is completed immediately before adult emergence, which means the muscles are adjustable during the entire morphogenesis in this group. Simple modifications probably based on a co-option of previously acquired genetic systems, the potential space for adding a new element, and an adjustable factor in morphogenesis of the intromittent organ facilitate the parallel evolution of the extreme elongation.

Why sauropods had long necks; and why giraffes have short necks.

The necks of the sauropod dinosaurs reached 15 m in length: six times longer than that of the world record giraffe and five times longer than those of all other terrestrial animals. Several anatomical features enabled this extreme elongation, including: absolutely large body size and quadrupedal stance providing a stable platform for a long neck; a small, light head that did not orally process food; cervical vertebrae that were both numerous and individually elongate; an efficient air-sac-based respiratory system; and distinctive cervical architecture. Relevant features of sauropod cervical vertebrae include: pneumatic chambers that enabled the bone to be positioned in a mechanically efficient way within the envelope; and muscular attachments of varying importance to the neural spines, epipophyses and cervical ribs. Other long-necked tetrapods lacked important features of sauropods, preventing the evolution of longer necks: for example, giraffes have relatively small torsos and large, heavy heads, share the usual mammalian constraint of only seven cervical vertebrae, and lack an air-sac system and pneumatic bones. Among non-sauropods, their saurischian relatives the theropod dinosaurs seem to have been best placed to evolve long necks, and indeed their necks probably surpassed those of giraffes. But 150 million years of evolution did not suffice for them to exceed a relatively modest 2.5 m.

Abstract TP212: Basilar Artery Diameter Is an Independent Predictor Of Incident Cardiovascular Disease

Background and purpose: Basilar arterial dolichoectasia, is extreme dilatation and elongation of the basilar artery (BA), is associated with intracranial bleeding, stroke mortality, and cardiovascular death. However, the association between moderate dilatation of the BA and subsequent cardiovascular events remains unclear. The study aims to clarify whether the BA diameter is an independent predictor of incident cardiovascular events. Methods: The study subjects comprised 493 outpatients aged 50 years or older with atherosclerotic risk factors, who underwent brain magnetic resonance imaging (MRI). The short axis of the BA diameter, cerebral infarcts, hemorrhagic lesions, the severity of deep white matter hyperintensities (DWMH), and intracranial steno-occlusive lesions were assessed with MRI and MR angiography. We prospectively evaluated the association between BA diameter and incident cardiovascular events such as cerebrovascular events, coronary heart events, and peripheral arterial events. The Kaplan-Meier method was used to analyze survival, and Cox regression models were used to examine prognostic variables. Results: The BA diameter ranged from 1.1 to 5.2 mm, and only 0.8% of the total patients had dolichoectasia. In the mean follow-up of 6.0 years, 91 patients developed cardiovascular events. BA diameter was independently associated with the cardiovascular events after adjusting for risk factors, stroke lesions, intracranial arterial steno-occlusion, and DWMH. Patients with large BA diameter (>2.7 mm) developed more cardiovascular events compared with those with small BA diameter (≤2.7 mm) (log-rank test; p <0.001). Among the cardiovascular events, BA diameter was most strongly associated with coronary heart events; however, it was not independently associated with cerebrovascular events. Conclusion: BA diameter is independently associated with incident cardiovascular events in high-risk patients. BA diameter could be a new predictive marker of cardiovascular events.

Mg-3Al-1Zn-1Ca 合金の圧延加工による結晶粒微細化と高強度化

The AZX (X = calcium) series of magnesium alloys have recently been developed as lightweight incombustible alloys for use in automotive and railway vehicles. However, magnesium alloys containing Ca show inferior plastic deformation and poor formability. The tensile properties of rolled and annealed samples of Mg-3Al-1Zn-1Ca (AZX311) alloy were examined. Sheets of this alloy subjected to a rolling process of three passes at 473 K without reheating showed a 0.2% proof stress of 361 MPa and a tensile strength of 373 MPa. The high strength of the AZX311 alloy sheet was the result of the effective grinding of compounds and their fine dispersal in the magnesium phases, which occurred during rolling deformation and grain refinement. After annealing, the growth of compounds and grains was improved without extreme elongation, but the strength of the compounds was maintained owing to their fine dispersion. The thermal stability of this alloy was improved by adding only 1 mass% elemental Ca.

Common Mechanism for Superplastic Deformation in Different Classes of Materials

An earlier proposal is generalized to explain superplasticity in different classes of materials and grain size ranges. A definition of “superplasticity” as due to a unique physical mechanism, rather than in terms of extreme elongations and/ or strain rate sensitivity index, m, being more than or equal to 0.30 emerges.

Extreme cervical elongation after sacrohysteropexy

We present a case of extreme cervical elongation with a cervix of 12 cm after an unusual operation in which the uterine corpus was directly fixed to the promontory, and which became symptomatic after 8 years. The possible pathophysiology of cervical elongation is discussed. Diagnosing a case of severe cervical elongation can be important in the pre-operative evaluation. It can alter the operative plan to a uterus-sparing technique or it can alert the surgeon to a difficult entry in the abdominal cavity during vaginal hysterectomy.

New Dromaeosaurids (Dinosauria: Theropoda) from the Lower Cretaceous of Utah, and the Evolution of the Dromaeosaurid Tail

BackgroundThe Yellow Cat Member of the Cedar Mountain Formation (Early Cretaceous, Barremian? – Aptian) of Utah has yielded a rich theropod fauna, including the coelurosaur Nedcolbertia justinhofmanni, the therizinosauroid Falcarius utahensis, the troodontid Geminiraptor suarezarum, and the dromaeosaurid Utahraptor ostrommaysorum. Recent excavation has uncovered three new dromaeosaurid specimens. One specimen, which we designate the holotype of the new genus and species Yurgovuchia doellingi, is represented by a partial axial skeleton and a partial left pubis. A second specimen consists of a right pubis and a possibly associated radius. The third specimen consists of a tail skeleton that is unique among known Cedar Mountain dromaeosaurids.Methodology/Principal Findings Y. doellingi resembles Utahraptor ostrommaysorum in that its caudal prezygapophyses are elongated but not to the degree present in most dromaeosaurids. The specimen represented by the right pubis exhibits a pronounced pubic tubercle, a velociraptorine trait that is absent in Y. doellingi. The specimen represented by the tail skeleton exhibits the extreme elongation of the caudal prezygapophyses that is typical of most dromaeosaurids. Here we perform a phylogenetic analysis to determine the phylogenetic position of Y. doellingi. Using the resulting phylogeny as a framework, we trace changes in character states of the tail across Coelurosauria to elucidate the evolution of the dromaeosaurid tail.Conclusions/SignificanceThe new specimens add to the known diversity of Dromaeosauridae and to the known diversity within the Yellow Cat paleofauna. Phylogenetic analysis places Y. doellingi in a clade with Utahraptor, Achillobator, and Dromaeosaurus. Character state distribution indicates that the presence of intermediate-length caudal prezygapophyses in that clade is not an evolutionarily precursor to extreme prezygapophyseal elongation but represents a secondary shortening of caudal prezygapophyses. It appears to represent part of a trend within Dromaeosauridae that couples an increase in tail flexibility with increasing size.

Disruption of OPR7 and OPR8 Reveals the Versatile Functions of Jasmonic Acid in Maize Development and Defense

Here, multiple functions of jasmonic acid (JA) in maize (Zea mays) are revealed by comprehensive analyses of JA-deficient mutants of the two oxo-phytodienoate reductase genes, OPR7 and OPR8. Single mutants produce wild-type levels of JA in most tissues, but the double mutant opr7 opr8 has dramatically reduced JA in all organs tested. opr7 opr8 displayed strong developmental defects, including formation of a feminized tassel, initiation of female reproductive buds at each node, and extreme elongation of ear shanks; these defects were rescued by exogenous JA. These data provide evidence that JA is required for male sex determination and suppression of female reproductive organ biogenesis. Moreover, opr7 opr8 exhibited delayed leaf senescence accompanied by reduced ethylene and abscisic acid levels and lack of anthocyanin pigmentation of brace roots. Remarkably, opr7 opr8 is nonviable in nonsterile soil and under field conditions due to extreme susceptibility to a root-rotting oomycete (Pythium spp), demonstrating that these genes are necessary for maize survival in nature. Supporting the importance of JA in insect defense, opr7 opr8 is susceptible to beet armyworm. Overall, this study provides strong genetic evidence for the global roles of JA in maize development and immunity to pathogens and insects.

Abstract 2961: Basilar Artery Diameter Is Associated With The Severity Of Cerebral Small-vessel Disease In Patients With Vascular Risk Factors

Background and purpose: Basilar arterial dolichoectasia (extreme enlargement and elongation) has been reported to be associated with cerebral small-vessel disease (CSVD) in stroke patients. The association of moderate dilatation of the basilar artery (BA) and CSVD or cerebrovascular risk factors is not clear. We analyzed BA diameter, stroke and white matter lesions, and other clinical factors in patients with atherosclerotic risk factors. Methods: The study subjects were 411 outpatients aged 50 or over who underwent brain magnetic resonance imaging (MRI) for clinical purposes. All patients had 1 or more atherosclerotic risk factors. The minor axis of the BA diameter was measured on the axial view of the T2-weighted MRI at midpons level. The location and size of the symptomatic and asymptomatic stroke lesions were evaluated. The severity of the deep white matter lesions were also assessed with Schelten’s score system by MRI. The anatomic variation in the posterior circle of Willis was assessed by MR angiography. Results: The diameter of BA was < 2.0 mm in 71 patients, 2.0 - 2.9 mm in 212 patients, 3.0 - 3.9 mm in 115 patients, 4.0 - 4.5 mm in 11 patients, and > 4.5 mm in 2 patients. In the univariate analysis, age, male gender, hypertension, low HDL cholesterol, the history of ischemic heart diseases, the presence of stroke lesions, and severity of deep white matter lesions were associated with BA diameter. Patients with infarctions ≤ 15 mm had larger size of BA than those with infarctions > 15 mm and those without infarctions. Patients with a bilateral adult-type posterior cerebral artery (PCA) had larger BA diameter than those with other types of PCA. In the multivariate regression analysis, male gender (P = 0.0002), the presence of stroke lesions (P = 0.009), severity of deep white matter lesions (P < 0.0001), and the variation in the posterior circle of Willis (P < 0.0001) were independently associated with BA diameter. Conclusion: BA diameter is associated with the severity of CSVD in high-risk patients. Dilatation process of BA and the development of CSVD may have common causes.

Homology of the internal sac components in the leaf beetle subfamily criocerinae and evolutionary novelties related to the extremely elongated flagellum

Extremely elongated intromittent organs are found in a wide range of taxa, especially among insects. This phenomenon is generally thought to result from sexual selection, but it is predicted that limited storage space in the body cavity and the difficulty of using the elongated organs should have constrained the evolution of extreme elongation, neutralizing any selective advantage. Therefore, in groups with long intromittent organs, features that overcome these constraints may have evolved or coevolved together with intromittent organ elongation. Using a comparative morphological approach and outgroup comparisons, we identified potential constraints and key novelties that may neutralize such constraints in the leaf beetle subfamily Criocerinae. Observations of the internal sac structure throughout Criocerinae were performed. Comparing the results with preceding studies from outgroups, a ground plan of the criocerine internal sac was constructed. Our analysis also identified specific features that are always correlated with extreme elongation: the rotation of whole internal-sac sclerites and the possession of a pocket in which to store the elongated flagellum. The pocket is thought to be formed by the rotation of the sclerites, markedly altering internal sac shape from the criocerine ground plan. Onlythe clades that have acquired this derived state contain species with an elongated flagellum that distinctly exceeds the median lobe length. It is presumed that these character correlations evolved independently three times. The detected character correlations corroborate the hypothesis that there are latent adaptive constraints for the evolution of extremely elongated intromittent organs. The constraints may have been neutralized by the alteration from the criocerine ground plan resulting in the formation of a storage pocket. In conclusion, deviation from the criocerine ground plan is considered to be the evolutionary innovation that neutralized the latent adaptive constraints of flagellum elongation in the subfamily Criocerinae.

Texture Analysis for Determining the Rate Controlling Process in the Transient and Steady State Regions of Superplastic Flow

Even anisotropic superplastic flow, which is a result of an elongated grain shape and texture, can lead to extreme elongations to fracture (superplasticity). Therefore, to identify the mechanisms of deformation present during superplastic flow alone, the effects of the microstructure should be eliminated first. Using an Al 5083 alloy, in which an equi-axed microstructure is present from the beginning, it is shown that grain boundary sliding, accompanied by grain rotations, is the rate controlling mechanism.

Factors responsible for deep-sowing tolerance in wheat seedlings: varietal differences in cell proliferation and the co-ordinated synchronization of epidermal cell expansion and cortical cell division for the gibberellin-mediated elongation of first internodes

A wheat cultivar, Triticum aestivum 'Hong Mang Mai', shows tolerance to deep-sowing conditions by extreme elongation of the first internode, likely mediated by the gibberellin (GA) response. To understand factors involved in the response of this deep-sowing-tolerant cultivar, cell expansion and division that confer elongation on the first internodes of wheat seedlings were investigated. The lengths and numbers of epidermal and cortical cells of the first internodes in three wheat cultivars were measured. These parameters were compared in wheat seedlings treated with gibberellin A(3) (GA(3)) or an inhibitor of GA biosynthesis, uniconazole. The varietal differences in the elongation of the first internodes were due to differences in cell numbers resulting from the different abilities of cell division, but not cell expansion. In seedlings treated with GA(3), the first internode of 'Hong Mang Mai' was 2-fold longer than the control. The GA-stimulated elongation of the first internodes was attributed to 2-fold increases in the number of cortical cells and length of epidermal cells. The different GA-responses observed in these two tissues were also detected in other cultivars, although the response was much lower than that noted in 'Hong Mang Mai'. The seedlings treated with uniconazole exhibited reduced numbers of cortical cells and reduced lengths of epidermal cells, with both of these effects being more pronounced in 'Hong Mang Mai'. The deep-sowing-tolerant cultivar 'Hong Mang Mai' is able to elongate the first internode to a greater degree due to enhanced cell division and a heightened response to GA. In addition, cell expansion in the epidermis and cell division in the cortex are synchronized for the elongation of the first internodes. In response to GA, this well-co-ordinated synchronization yields the rapid elongation of the first internodes in wheat seedlings.