Evolutionary traces of miniaturization in a giant—Comparative anatomy of brain and brain nerves in Bathochordaeus stygius (Tunicata, Appendicularia)

Appendicularia comprises 70 marine, invertebrate, chordate species. Appendicularians play important ecological and evolutionary roles, yet their morphological disparity remains understudied. Most appendicularians are small, develop rapidly, and with a stereotyped cell lineage, leading to the hypothesis that Appendicularia derived progenetically from an ascidian-like ancestor. Here, we describe the detailed anatomy of the central nervous system of Bathochordaeus stygius, a giant appendicularian from the mesopelagic. We show that the brain consists of a forebrain with on average smaller and more uniform cells and a hindbrain, in which cell shapes and sizes vary to a greater extent. Cell count for the brain was 102. We demonstrate the presence of three paired brain nerves. Brain nerve 1 traces into the epidermis of the upper lip region and consists of several fibers with some supportive bulb cells in its course. Brain nerve 2 innervates oral sensory organs and brain nerve 3 innervates the ciliary ring of the gill slits and lateral epidermis. Brain nerve 3 is asymmetric, with the right nerve consisting of two neurites originating posterior to the left one that contains three neurites. Similarities and differences to the anatomy of the brain of the model species Oikopleura dioica are discussed. We interpret the small number of cells in the brain of B. stygius as an evolutionary trace of miniaturization and conclude that giant appendicularians evolved from a small, progenetic ancestor that secondarily increased in size within Appendicularia.Deutsche Forschungsgemeinschaft http://dx.doi.org/10.13039/501100001659David and Lucile Packard Foundation http://dx.doi.org/10.13039/100000008Peer Reviewe

Large-scale Graphitic Thin Films Synthesized on Ni and Transferred to Insulators: Structural and Electronic Properties

We present a comprehensive study of the structural and electronic properties of ultrathin films containing graphene layers synthesized by chemical vapor deposition (CVD) based surface segregation on polycrystalline Ni foils then transferred onto insulating SiO2/Si substrates. Films of size up to several mm's have been synthesized. Structural characterizations by atomic force microscopy (AFM), scanning tunneling microscopy (STM), cross-sectional transmission electron microscopy (XTEM) and Raman spectroscopy confirm that such large scale graphitic thin films (GTF) contain both thick graphite regions and thin regions of few layer graphene. The films also contain many wrinkles, with sharply-bent tips and dislocations revealed by XTEM, yielding insights on the growth and buckling processes of the GTF. Measurements on mm-scale back-gated transistor devices fabricated from the transferred GTF show ambipolar field effect with resistance modulation ~50% and carrier mobilities reaching ~2000 cm^2/Vs. We also demonstrate quantum transport of carriers with phase coherence length over 0.2 $\mu$m from the observation of 2D weak localization in low temperature magneto-transport measurements. Our results show that despite the non-uniformity and surface roughness, such large-scale, flexible thin films can have electronic properties promising for device applications.Comment: This version (as published) contains additional data, such as cross sectional TEM image

Control and Characterization of Individual Grains and Grain Boundaries in Graphene Grown by Chemical Vapor Deposition

The strong interest in graphene has motivated the scalable production of high quality graphene and graphene devices. Since large-scale graphene films synthesized to date are typically polycrystalline, it is important to characterize and control grain boundaries, generally believed to degrade graphene quality. Here we study single-crystal graphene grains synthesized by ambient CVD on polycrystalline Cu, and show how individual boundaries between coalescing grains affect graphene's electronic properties. The graphene grains show no definite epitaxial relationship with the Cu substrate, and can cross Cu grain boundaries. The edges of these grains are found to be predominantly parallel to zigzag directions. We show that grain boundaries give a significant Raman "D" peak, impede electrical transport, and induce prominent weak localization indicative of intervalley scattering in graphene. Finally, we demonstrate an approach using pre-patterned growth seeds to control graphene nucleation, opening a route towards scalable fabrication of single-crystal graphene devices without grain boundaries.Comment: New version with additional data. Accepted by Nature Material

The Indo-European flyway: Opportunities and constraints reflected by Common Rosefinches breeding across Europe

Aim The configuration of the earth's landmasses influences global weather systems and spatiotemporal resource availability, thereby shaping biogeographical patterns and migratory routes of animals. Here, we aim to identify potential migratory barriers and corridors, as well as general migration strategies within the understudied Indo-European flyway.Location Europe, Central Asia.Major taxon studied Common rosefinches.Methods We used a combination of theoretical optimization modelling and empirical tracking of Common Rosefinches (Carpodacus erythrinus) breeding across a large latitudinal gradient in Europe. First, we identified optimal migration routes driven by wind and resource availability along the Indo-European flyway. Second, we tracked rosefinches from five breeding populations using light-level geolocators. Finally, we compared to what extent empirical tracks overlapped with the modelled optimal routes.ResultsIn autumn, theoretical wind driven migration routes formed a broad-front corridor connecting Europe and the Indian Subcontinent while the theoretical resource driven routes formed a distinct north-south divide. The latter pattern also reflected the rosefinch tracks with all but the most southerly breeding birds making a northern detour towards non-breeding sites in Pakistan and India. In spring, the resource availability model predicted a similar migratory divide, however, the southern route seemed relatively more favourable and closely matched with the optimal wind driven migration routes. Spring tracking data showed larger overlap with the modelled wind driven migration routes compared to the resource driven routes.Main conclusionsOptimal wind and resource driven migration routes along the Indo-European flyway are seasonally specific and to a large extend do not overlap with one another. Under these conditions, migratory birds adopt seasonally distinct migration strategies following energy minimization strategy in autumn, driven by resource availability, and time minimizing strategy in spring, driven by wind conditions. Our optimal migration models can be applied worldwide and used to validate against empirical data to explain large-scale biogeographic pattern of migratory animals.</p

Case Reports1. A Late Presentation of Loeys-Dietz Syndrome: Beware of TGFβ Receptor Mutations in Benign Joint Hypermobility

Background: Thoracic aortic aneurysms (TAA) and dissections are not uncommon causes of sudden death in young adults. Loeys-Dietz syndrome (LDS) is a rare, recently described, autosomal dominant, connective tissue disease characterized by aggressive arterial aneurysms, resulting from mutations in the transforming growth factor beta (TGFβ) receptor genes TGFBR1 and TGFBR2. Mean age at death is 26.1 years, most often due to aortic dissection. We report an unusually late presentation of LDS, diagnosed following elective surgery in a female with a long history of joint hypermobility. Methods: A 51-year-old Caucasian lady complained of chest pain and headache following a dural leak from spinal anaesthesia for an elective ankle arthroscopy. CT scan and echocardiography demonstrated a dilated aortic root and significant aortic regurgitation. MRA demonstrated aortic tortuosity, an infrarenal aortic aneurysm and aneurysms in the left renal and right internal mammary arteries. She underwent aortic root repair and aortic valve replacement. She had a background of long-standing joint pains secondary to hypermobility, easy bruising, unusual fracture susceptibility and mild bronchiectasis. She had one healthy child age 32, after which she suffered a uterine prolapse. Examination revealed mild Marfanoid features. Uvula, skin and ophthalmological examination was normal. Results: Fibrillin-1 testing for Marfan syndrome (MFS) was negative. Detection of a c.1270G > C (p.Gly424Arg) TGFBR2 mutation confirmed the diagnosis of LDS. Losartan was started for vascular protection. Conclusions: LDS is a severe inherited vasculopathy that usually presents in childhood. It is characterized by aortic root dilatation and ascending aneurysms. There is a higher risk of aortic dissection compared with MFS. Clinical features overlap with MFS and Ehlers Danlos syndrome Type IV, but differentiating dysmorphogenic features include ocular hypertelorism, bifid uvula and cleft palate. Echocardiography and MRA or CT scanning from head to pelvis is recommended to establish the extent of vascular involvement. Management involves early surgical intervention, including early valve-sparing aortic root replacement, genetic counselling and close monitoring in pregnancy. Despite being caused by loss of function mutations in either TGFβ receptor, paradoxical activation of TGFβ signalling is seen, suggesting that TGFβ antagonism may confer disease modifying effects similar to those observed in MFS. TGFβ antagonism can be achieved with angiotensin antagonists, such as Losartan, which is able to delay aortic aneurysm development in preclinical models and in patients with MFS. Our case emphasizes the importance of timely recognition of vasculopathy syndromes in patients with hypermobility and the need for early surgical intervention. It also highlights their heterogeneity and the potential for late presentation. Disclosures: The authors have declared no conflicts of interes

Identifying the quality of life effects of urinary incontinence with depression in an Australian population

Background: To explore the additive effect of urinary incontinence, in people with comorbid depression, on health related quality of life. Methods: Males and females, 15 to 95 years (n = 3010, response rate 70.2%) were interviewed face to face in the 1998 Autumn South Australian Health Omnibus Survey. Results: Self-reported urinary incontinence was found in 20.3% (n=610), and depression as defined by the PRIME-MD in 15.2% (n=459) of the survey population. Urinary incontinence with comorbid depression was found in 4.3% of the overall population. Univariate analysis showed that respondents with urinary incontinence and comorbid depression were more likely to be aged between 15 and 34 years and never married when compared to those with incontinence only. Multivariate analysis demonstrated that in people with incontinence, the risk of having comorbid depression was increased by an overall health status of Fair or Poor, or the perception that their incontinence was moderately or very serious. Respondents reporting that they experienced incontinence with comorbid depression scored significantly lower than those experiencing incontinence without depression on all dimensions of the SF-36. The interaction of the presence of incontinence and the presence of depression was significantly associated with the dimensions of physical functioning. Conclusions: Depression and incontinence both reduce QOL. When they occur together there appears to be an additive effect which affects both physical and mental health, perhaps by increasing a person’s negative perceptions of their illness. Clinicians should identify and manage comorbid depression when treating patients who have incontinence to improve their overall QOL.Jodie C Avery, Nigel P Stocks, Paul Duggan, Annette J Braunack-Mayer, Anne W Taylor, Robert D Goldney and Alastair H MacLenna

Migratory routes and stopover behaviour in avian migration

Migratory birds, some small and light weight as matchboxes, engage in seasonal inter-continental journeys in order to take advantage of the long summer days and abundance of food at northern latitudes to breed and raise their young, and then escape the harsh winters by migrating to lower latitudes. This thesis deals with two important aspects of migration, the routes taken during migration and the birds’ behaviour at stopovers. The migratory routes are for many species unknown, whole or in part, and this is especially true for species that migrate nocturnally. At stopovers birds replenish fuel reserves that powers migratory flight, and studying how birds utilise stopovers is important in order to understand how migration is organised. In this thesis I have used modern tracking technology to study both continental wide movements of thrush nightingales (Luscinia luscinia) and common rosefinches (Carpodacus erythrinus) using small light-level geolocators, and smaller scale movements at a single stopover site of garden warblers (Sylvia borin) using miniature radio-transmitters. I have also studied the fuelling behaviour of garden warblers during autumn migration in the field and in the lab, and great reed warblers (Acrocephalus arundinaceus) at a stopover site on Crete during spring migration after the Sahara crossing. The thesis discusses the significance of several aspects of migration shown by the birds that would have been very difficult to detect without the aid of modern tracking technology, such as loop migration, prolonged stops during migration, multiple wintering sites, and nocturnal relocations at stopover sites. Studies carried out at stopover sites also show that garden warblers and great reed warblers can attain large fuel loads even at sites where they have no barrier to cross and this might be a result of good foraging conditions. The thesis also highlights the importance of combining different techniques when studying stopover behaviour to get reliable estimates on stopover durations and fuel deposition rates as well as the importance of choosing sites preferred by birds when planning stopover studies.At the time of the doctoral defense, the following papers were unpublished and had a status as follows: Paper 4: Manuscript. Paper 5: Manuscript.</p

Evaluation of the Minimal Auditory Capabilities (MAC) Test in Prelingual and Postlingual Hearing-Impaired Adults

The Minimal Auditory Capabilities (MAC) battery was used to evaluate the auditory performance of nine postlingual and ten prelingual adults with severe to profound hearing loss. Results suggest that degree of hearing loss overrides relative language skills as the primary factor affecting performance. The MAC battery appears promising as a tool for evaluating and monitoring both prelingual and postlingual adults using conventional hearing aids or cochlear implants