Anatomy of an agricultural antagonist: Feeding complex structure and function of three xylem sap-feeding insects illuminated with synchrotron-based 3D imaging.

Many insects feed on xylem or phloem sap of vascular plants. Although physical damage to the plant is minimal, the process of insect feeding can transmit lethal viruses and bacterial pathogens. Disparities between insect-mediated pathogen transmission efficiency have been identified among xylem sap-feeding insects; however, the mechanistic drivers of these trends are unclear. Identifying and understanding the structural factors and associated integrated functional components that may ultimately determine these disparities are critical for managing plant diseases. Here, we applied synchrotron-based X-ray microcomputed tomography to digitally reconstruct the morphology of three xylem sap-feeding insect vectors of plant pathogens: Graphocephala atropunctata (blue-green sharpshooter; Hemiptera, Cicadellidae) and Homalodisca vitripennis (glassy-winged sharpshooter; Hemiptera, Cicadellidae), and the spittlebug Philaenus spumarius (meadow spittlebug; Hemiptera, Aphrophoridae). The application of this technique revealed previously undescribed anatomical features of these organisms, such as key components of the salivary complex. The visualization of the 3D structure of the precibarial valve led to new insights into the mechanism of how this structure functions. Morphological disparities with functional implications between taxa were highlighted as well, including the morphology and volume of the cibarial dilator musculature responsible for extracting xylem sap, which has implications for force application capabilities. These morphological insights will be used to target analyses illuminating functional differences in feeding behavior.

Back to life: Techniques for developing high-quality 3D reconstructions of plants and animals from digitized specimens.

Expanded use of 3D imaging in organismal biology and paleontology has substantially enhanced the ability to visualize and analyze specimens. These techniques have improved our understanding of the anatomy of many taxa, and the integration of downstream computational tools applied to 3D datasets have broadened the range of analyses that can be performed (e.g., finite element analyses, geometric morphometrics, biomechanical modeling, physical modeling using 3D printing). However, morphological analyses inevitably present challenges, particularly in fossil taxa where taphonomic or preservational artifacts distort and reduce the fidelity of the original morphology through shearing, compression, and disarticulation, for example. Here, we present a compilation of techniques to build high-quality 3D digital models of extant and fossil taxa from 3D imaging data using freely available software for students and educators. Our case studies and associated step-by-step supplementary tutorials present instructions for working with reconstructions of plants and animals to directly address and resolve common issues with 3D imaging data. The strategies demonstrated here optimize scientific accuracy and computational efficiency and can be applied to a broad range of taxa.

A permineralized Early Cretaceous lycopsid from China and the evolution of crown clubmosses.

Lycopodiaceae are one of three surviving families of lycopsids, a lineage of vascular plants with a fossil history dating to at least the Early Devonian or perhaps the Late Silurian (c. 415 Ma). Many fossils have been linked to crown Lycopodiaceae, but the lack of well-preserved material has hindered definitive recognition of this group in the paleobotanical record. New, exceptionally well-preserved permineralized lycopsid fossils from the Early Cretaceous (125.6 ± 1.0 Ma) of Inner Mongolia, China, were examined in detail using acetate peel and micro-computed tomography techniques. The anatomy of extant Lycopodiaceae was analyzed for comparison using fluorescence microscopy. Phylogenetic relationships of the new fossil to extant Lycopodiaceae were evaluated using parsimony and maximum likelihood analyses. Lycopodicaulis oellgaardii gen. et sp. nov. provides the earliest unequivocal and best-documented evidence of crown Lycopodiaceae and Lycopodioideae, based on anatomically-preserved fossil material. Recognition of Lycopodicaulis in Asia during the Early Cretaceous indicates the presence of crown Lycopodiaceae at this time, and striking similarities of stem anatomy with extant species provide a framework for the understanding of the interaction of branching and vascular anatomy in crown-group lycopsids.

Crab in amber reveals an early colonization of nonmarine environments during the Cretaceous.

Amber fossils provide snapshots of the anatomy, biology, and ecology of extinct organisms that are otherwise inaccessible. The best-known fossils in amber are terrestrial arthropods­principally insects­whereas aquatic organisms are rarely represented. Here, we present the first record of true crabs (Brachyura) in amber­from the Cretaceous of Myanmar [~100 to 99 million years (Ma)]. The new fossil preserves large compound eyes, delicate mouthparts, and even gills. This modern-looking crab is nested within crown Eubrachyura, or "higher" true crabs, which includes the majority of brachyuran species living today. The fossil appears to have been trapped in a brackish or freshwater setting near a coastal to fluvio-estuarine environment, bridging the gap between the predicted molecular divergence of nonmarine crabs (~130 Ma) and their younger fossil record (latest Cretaceous and Paleogene, ~75 to 50 Ma) while providing a reliable calibration point for molecular divergence time estimates for higher crown eubrachyurans.

Mesozoic cupules and the origin of the angiosperm second integument.

The second integument of the angiosperm ovule is unique among seed plants, with developmental genetics that are distinct from those of the inner integument1. Understanding how the second integument should be compared to structures in other seed plants is therefore crucial to resolving the long-standing question of the origin of angiosperms2-6. Attention has focused on several extinct plants with recurved cupules that are reminiscent of the anatropous organization of the basic bitegmic ovules of angiosperms1-6, but interpretations have been hampered by inadequate information on the relevant fossils. Here we describe abundant exceptionally well-preserved recurved cupules from a newly discovered silicified peat dating to the Early Cretaceous epoch (around 125.6 million years ago) in Inner Mongolia, China. The new material, combined with re-examination of potentially related fossils, indicates that the recurved cupules of several groups of Mesozoic plants are all fundamentally comparable, and that their structure is consistent with the recurved form and development of the second integument in the bitegmic anatropous ovules of angiosperms. Recognition of these angiosperm relatives (angiophytes) provides a partial answer to the question of angiosperm origins, will help to focus future work on seed plant phylogenetics and has important implications for ideas on the origin of the angiosperm carpel.

Arm waving in stylophoran echinoderms: three-dimensional mobility analysis illuminates cornute locomotion.

The locomotion strategies of fossil invertebrates are typically interpreted on the basis of morphological descriptions. However, it has been shown that homologous structures with disparate morphologies in extant invertebrates do not necessarily correlate with differences in their locomotory capability. Here, we present a new methodology for analysing locomotion in fossil invertebrates with a rigid skeleton through an investigation of a cornute stylophoran, an extinct fossil echinoderm with enigmatic morphology that has made its mode of locomotion difficult to reconstruct. We determined the range of motion of a stylophoran arm based on digitized three-dimensional morphology of an early Ordovician form, Phyllocystis crassimarginata. Our analysis showed that efficient arm-forward epifaunal locomotion based on dorsoventral movements, as previously hypothesized for cornute stylophorans, was not possible for this taxon; locomotion driven primarily by lateral movement of the proximal aulacophore was more likely. Three-dimensional digital modelling provides an objective and rigorous methodology for illuminating the movement capabilities and locomotion strategies of fossil invertebrates.

Decentralized Control Mechanism for Determination of Moving Direction in Brittle Stars With Penta-Radially Symmetric Body.

A brittle star, an echinoderm with penta-radially symmetric body, can make decisions about its moving direction and move adapting to various circumstances despite lacking a central nervous system and instead possessing a rather simple distributed nervous system. In this study, we aimed to elucidate the essential control mechanism underlying the determination of moving direction in brittle stars. Based on behavioral findings on brittle stars whose nervous systems were lesioned in various ways, we propose a phenomenological mathematical model. We demonstrate via simulations that the proposed model can well reproduce the behavioral findings. Our findings not only provide insights into the mechanism for the determination of moving direction in brittle stars, but also help understand the essential mechanism underlying autonomous behaviors of animals. Moreover, they will pave the way for developing fully autonomous robots that can make decisions by themselves and move adaptively under various circumstances.

The function of the ophiuroid nerve ring: how a decentralized nervous system controls coordinated locomotion.

Echinoderms lack a centralized nervous control system, yet each extant echinoderm class has evolved unique and effective strategies for locomotion. Brittle stars (Ophiuroidea) stride swiftly over the seafloor by coordinating motions of their five muscular arms. Their arms consist of many repeating segments, requiring them to use a complex control system to coordinate motions among segments and between arms. We conducted in vivo experiments with brittle stars to analyze the functional role of the nerve ring, which connects the nerves in each arm. These experiments were designed to determine how the ophiuroid nervous system performs complex decision making and locomotory actions under decentralized control. Our results show that brittle star arms must be connected by the nerve ring for coordinated locomotion, but information can travel bidirectionally around the nerve ring so that it circumvents the severance. Evidence presented indicates that ophiuroids rely on adjacent nerve ring connections for sustained periodic movements. The number of arms connected via the nerve ring is correlated positively with the likelihood that the animal will show coordinated locomotion, indicating that integrated nerve ring tissue is critical for control. The results of the experiments should provide a basis for the advancement of complex artificial decentralized systems.

Integrating morphology and in vivo skeletal mobility with digital models to infer function in brittle star arms.

Brittle stars (Phylum Echinodermata, Class Ophiuroidea) have evolved rapid locomotion employing muscle and skeletal elements within their (usually) five arms to apply forces in a manner analogous to that of vertebrates. Inferring the inner workings of the arm has been difficult as the skeleton is internal and many of the ossicles are sub-millimeter in size. Advances in 3D visualization and technology have made the study of movement in ophiuroids possible. We developed six virtual 3D skeletal models to demonstrate the potential range of motion of the main arm ossicles, known as vertebrae, and six virtual 3D skeletal models of non-vertebral ossicles. These models revealed the joint center and relative position of the arm ossicles during near-maximal range of motion. The models also provide a platform for the comparative evaluation of functional capabilities between disparate ophiuroid arm morphologies. We made observations on specimens of Ophioderma brevispina and Ophiothrix angulata. As these two taxa exemplify two major morphological categories of ophiuroid vertebrae, they provide a basis for an initial assessment of the functional consequences of these disparate vertebral morphologies. These models suggest potential differences in the structure of the intervertebral articulations in these two species, implying disparities in arm flexion mechanics. We also evaluated the differences in the range of motion between segments in the proximal and distal halves of the arm length in a specimen of O. brevispina, and found that the morphology of vertebrae in the distal portion of the arm allows for higher mobility than in the proximal portion. Our models of non-vertebral ossicles show that they rotate further in the direction of movement than the vertebrae themselves in order to accommodate arm flexion. These findings raise doubts over previous hypotheses regarding the functional consequences of ophiuroid arm disparity. Our study demonstrates the value of integrating experimental data and visualization of articulated structures when making functional interpretations instead of relying on observations of vertebral or segmental morphology alone. This methodological framework can be applied to other ophiuroid taxa to enable comparative functional analyses. It will also facilitate biomechanical analyses of other invertebrate groups to illuminate how appendage or locomotor function evolved.

Water vascular system architecture in an Ordovician ophiuroid.

Understanding the water vascular system (WVS) in early fossil echinoderms is critical to elucidating the evolution of this system in extant forms. Here we present the first report of the internal morphology of the water vascular system of a stem ophiuroid. The radial canals are internal to the arm, but protected dorsally by a plate separate to the ambulacrals. The canals zig-zag with no evidence of constrictions, corresponding to sphincters, which control pairs of tube feet in extant ophiuroids. The morphology suggests that the unpaired tube feet must have operated individually, and relied on the elasticity of the radial canals, lateral valves and tube foot musculature alone for extension and retraction. This arrangement differs radically from that in extant ophiuroids, revealing a previously unknown Palaeozoic configuration.

Epidemiology of Emergency Medical Services (EMS) Utilization in Four Indian Emergency Departments.

Introduction Without a universal Emergency Medical Services (EMS) system in India, data on the epidemiology of patients who utilize EMS are limited. This retrospective chart review aimed to quantify and describe the burden of disease and patient demographics of patients who arrived by EMS to four Indian emergency departments (EDs) in order to inform a national EMS curriculum. METHODS: A retrospective chart review was performed on patients transported by EMS over a three-month period in 2014 to four private EDs in India. A total of 17,541 patient records were sampled from the four sites over the study period. Of these records, 1,723 arrived by EMS and so were included for further review. RESULTS: A range of 1.4%-19.4% of ED patients utilized EMS to get to the ED. The majority of EMS patients were male (59%-64%) and adult or geriatric (93%-99%). The most common chief complaints and ED diagnoses were neurological, pulmonary, cardiovascular, gastrointestinal, trauma, and infectious disease. CONCLUSIONS: Neurological, pulmonary, cardiovascular, gastrointestinal, trauma, and infectious disease are the most common problems found in patients transported by EMS in India. Adult and geriatric male patients are the most common EMS utilizers. Emergency Medical Services curricula should emphasize these knowledge areas and skills. Wijesekera O , Reed A , Chastain PS , Biggs S , Clark EG , Kole T , Chakrapani AT , Ashish N , Rajhans P , Breaud AH , Jacquet GA . Epidemiology of Emergency Medical Services (EMS) utilization in four Indian emergency departments. Prehosp Disaster Med. 2016;31(6):675-679.

Acute care needs in an Indian emergency department: A retrospective analysis.

BACKGROUND: Emergencies such as road traffic accidents (RTAs), acute myocardial infarction (AMI) and cerebrovascular accident (CVA) are the most common causes of death and disability in India. Robust emergency medicine (EM) services and proper education on acute care are necessary. In order to inform curriculum design for training programs, and to improve the quality of EM care in India, a better understanding of patient epidemiology and case burden presenting to the emergency department (ED) is needed. METHODS: This study is a retrospective chart review of cases presenting to the ED at Kerala Institute of Medical Sciences (KIMS), a private hospital in Trivandrum, Kerala, India, from November 1, 2011 to April 21, 2012 and from July 1, 2013 to December 21, 2013. De-identified charts were systematically sampled and reviewed. RESULTS: A total of 1 196 ED patient charts were analyzed. Of these patients, 55.35% (n=662) were male and 44.7% (n=534) were female. The majority (67.14%, n=803) were adults, while only 3.85% (n=46) were infants. The most common chief complaints were fever (21.5%, n=257), renal colic (7.3%, n=87), and dyspnea (6.9%, n=82). The most common ED diagnoses were gastrointestinal (15.5%, n=185), pulmonary (12.3%, n=147), tropical (11.1%, n=133), infectious disease and sepsis (9.9%, n=118), and trauma (8.4%, n=101). CONCLUSION: The patient demographics, diagnoses, and distribution of resources identified by this study can help guide and shape Indian EM training programs and faculty development to more accurately reflect the burden of acute disease in India.

The 'Tully monster' is a vertebrate.

Problematic fossils, extinct taxa of enigmatic morphology that cannot be assigned to a known major group, were once a major issue in palaeontology. A long-favoured solution to the 'problem of the problematica', particularly the 'weird wonders' of the Cambrian Burgess Shale, was to consider them representatives of extinct phyla. A combination of new evidence and modern approaches to phylogenetic analysis has now resolved the affinities of most of these forms. Perhaps the most notable exception is Tullimonstrum gregarium, popularly known as the Tully monster, a large soft-bodied organism from the late Carboniferous Mazon Creek biota (approximately 309-307 million years ago) of Illinois, USA, which was designated the official state fossil of Illinois in 1989. Its phylogenetic position has remained uncertain and it has been compared with nemerteans, polychaetes, gastropods, conodonts, and the stem arthropod Opabinia. Here we review the morphology of Tullimonstrum based on an analysis of more than 1,200 specimens. We find that the anterior proboscis ends in a buccal apparatus containing teeth, the eyes project laterally on a long rigid bar, and the elongate segmented body bears a caudal fin with dorsal and ventral lobes. We describe new evidence for a notochord, cartilaginous arcualia, gill pouches, articulations within the proboscis, and multiple tooth rows adjacent to the mouth. This combination of characters, supported by phylogenetic analysis, identifies Tullimonstrum as a vertebrate, and places it on the stem lineage to lampreys (Petromyzontida). In addition to increasing the known morphological disparity of extinct lampreys, a chordate affinity for T. gregarium resolves the nature of a soft-bodied fossil which has been debated for more than 50 years.

Headache improvement through TMD stabilization appliance and self-management therapies.

The purpose of this study was to assess headache response of unselected neurology clinic chronic headache patients to TMD stabilization appliance and self-management therapies, and to identify features of patients whose headaches are more likely to improve from these therapies. Twenty chronic headache patients in a nontreatment control period were provided appliance and self-management therapies, evaluated five weeks after therapy, and those who chose to continue using their appliances were evaluated three months later. The mean pretreatment Headache Disability Inventory (HDI) score of 64.5 suggested the headaches were severe. After five weeks, the mean HDI score decreased by 17 percent (p<0.003), headache medication consumption dropped by 18 percent (p<0.0001), and headache symptoms decreased by 19 percent (p<0.002). Comparing the three months with pretreatment follow-up, the fourteen participants who chose to continue using their appliances had a mean HDI score decrease of 23 percent (p<0.003), headache medication consumption drop of 46 percent (p<0.001), and headache symptom decrease of 39 percent (p<0.001). There was no correlation between response and headache type (p=0.722). These results suggest appliance and self-management therapies can be beneficial for many severe headache patients, irrespective of the headache type (tension-type, migraine without aura, and migraine with aura).

Health care decision-making for others--no easy answers.

This Article introduces a Symposium on the topic of advance medical directive. It provides a brief history of living wills, and then generally discusses the difficulties associated with clearly defining an individual's healthcare wishes in advance of the onset of health problems.