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Samantha L Rumschlag, Michelle D Boone
The result of pathogen exposures may depend upon trade-offs in energetic demands for immune responses against host growth and survival. Environmental conditions may influence these trade-offs by affecting host size, or trade-offs may change across seasons, altering impacts of pathogens. We exposed northern leopard frog Lithobates pipiens tadpoles to different larval environments (low leaf litter, high density of conspecifics, atrazine, caged fish, or controls) that influenced size at metamorphosis. Subsequently, we exposed metamorphs to Batrachochytrium dendrobatidis (Bd), a fungal pathogen, just after metamorphosis and/or prior to overwintering 12 wk later...
October 16, 2018: Diseases of Aquatic Organisms
Marine Fau, Loïc Villier
The complete ontogenetic development of an asteroid skeleton has never been described formally for any species. Here, we describe in detail the post-metamorphic ontogeny of Zoroaster fulgens Thomson, 1873. The major novelty of our work is the description of patterns of plate addition, the ontogeny of the internal ossicles, as well as the variability of ossicles according to their position along series. Seven specimens collected in the Rockall Basin (North Atlantic) were dissected with bleach and their anatomy was documented using a scanning electron microscope...
November 2018: Journal of Anatomy
Yihong Zhou, Majors J Badgett, Ron Orlando, Judith H Willis
Anopheles gambiae devotes over 2% of its protein coding genes to its 298 structural cuticular proteins (CPs). This paper provides new LC-MS/MS data on two adult structures, proboscises and palps, as well as three larval samples - 4th instar larvae, just their terminal segment, and a preparation enriched in their tracheae. These data were combined with our previously published results of proteins from five other adult structures, whole adults, and two preparations chosen for their relatively clean cuticle, the larval head capsules left behind after ecdysis and the pupal cuticles left behind after adult eclosion...
September 29, 2018: Insect Biochemistry and Molecular Biology
Peter A Cawood, Chris J Hawkesworth, Sergei A Pisarevsky, Bruno Dhuime, Fabio A Capitanio, Oliver Nebel
Plate tectonics, involving a globally linked system of lateral motion of rigid surface plates, is a characteristic feature of our planet, but estimates of how long it has been the modus operandi of lithospheric formation and interactions range from the Hadean to the Neoproterozoic. In this paper, we review sedimentary, igneous and metamorphic proxies along with palaeomagnetic data to infer both the development of rigid lithospheric plates and their independent relative motion, and conclude that significant changes in Earth behaviour occurred in the mid- to late Archaean, between 3...
October 1, 2018: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
J S Kayode, Y Yusup, M N M Nawawi, K S Ariffin, A E Kalil, M G Tagwa
Energy Dispersive X-ray Analysis, EDX mapping, Scanning Electron Microscope, SEM, together with X-ray Fluorescence Analysis, XRF, was carried out to extract the needed data from some metamorphic rock samples in part of the Nigerian Southwestern Precambrian Basement Complex, NSPBC. The foremost aim is to obtain the detail subsurface geological structures of the rocks within the area and to enhanced understanding of the processes and the types of metamorphic evolution in the area. The techniques involved qualitative and quantitative data analysis of the major, minor and radioactive elements present in the samples of rocks analyzed...
October 2018: Data in Brief
Urtzi Enriquez-Urzelai, Antonio S Palacio, Natalia Mendez, Martina Sacco, Alfredo G Nicieza
Adaptation to warming climates could counteract the effects of global warming. Thus, understanding how species cope with contrasting climates may inform us about their potential for thermal adaptation and which processes may hamper that ability (e.g. evolutionary trade-offs, phenology, or behavioural thermoregulation). In addition to temperature, time constraints may also exert important selective pressures. Here we compare the thermal sensitivity of locomotion of metamorphic and adult European common frogs (Rana temporaria) originating from populations along an elevational gradient...
September 26, 2018: Journal of Evolutionary Biology
Leesa M Keogh, Aimee J Silla, Michael S McFadden, Phillip G Byrne
Carotenoids are known for their antioxidant capacity and are considered to play an important role in vertebrate growth and development. However, evidence for their beneficial effects remains limited, possibly because very few studies have tested for dose effects across different life stages. The present study investigated the effect of various doses of dietary beta-carotene supplements on the growth and development of larval and post-metamorphic Booroolong frogs ( Litoria booroolongensis ). Larval and post-metamorphic basal diets (containing 0...
2018: Conservation Physiology
S Chafino, D López-Escardó, G Benelli, H Kovac, E Casacuberta, X Franch-Marro, J Kathirithamby, D Martín
Holometaboly is a key evolutionary innovation that has facilitated the spectacular radiation of insects. Despite the undeniable advantage of complete metamorphosis, the female of some holometabolous species have lost the typical holometabolous development through neoteny. In Xenos vesparum Rossi (Strepsiptera: Stylopidae), a derived species of the holometabolous endoparasitic order Strepsiptera, neotenic females reach sexual maturity without the pupal and the imaginal stages, thus retaining their larval morphology (with the exception of the anterior part of the body or cephalothorax), while males undergo normal pupal-based metamorphosis...
September 21, 2018: Scientific Reports
Douglas J Fort, Michael B Mathis, Patrick D Guiney, John A Weeks
A 150-day post-metamorphosis (dpm) partial lifecycle study exposing Silurana tropicalis to <0.03 (control), 0.06, 0.13 0.25, 0.5 and 1.0 mg/L perfluorooctanesulfonate (PFOS) was conducted. A subset of specimens from the control and each treatment were evaluated at metamorphic completion. A significant increase in the median metamorphosis time was observed in the 1.0 mg/L PFOS treatment relative to the control. A modest increase in the occurrence, but not severity, of mild follicular hypertrophy was found in thyroid glands from organisms exposed to the 0...
September 14, 2018: Journal of Applied Toxicology: JAT
Huijuan Li, Qi Li, Hong Yu, Shaojun Du
Pacific oyster (Crassostrea gigas) is a sessile bivalve living in the intertidal zone. It has become an attractive model for developmental studies due to its metamorphic transition from a mobile planktonic larvae to a sessile adults. To determine the effect of metamorphosis on muscle development in oyster larvae, we characterized myogenesis during larval development and metamorphosis by phalloidin staining which labels filamentous actin filaments. Our data revealed a dynamic pattern of myogenesis during embryonic and larval development...
September 5, 2018: Comparative Biochemistry and Physiology. Part B, Biochemistry & Molecular Biology
Sara J McClelland, Randall J Bendis, Rick A Relyea, Sarah K Woodley
Widespread use of pesticides often contaminates natural habitats, exposing nontarget organisms to pesticides that were designed to control pest populations. Even low levels of pesticides can affect aquatic communities both directly and indirectly. Previous work has shown that trace amounts of the pesticide chlorpyrifos altered tadpole morphology and neurodevelopment in artificial ponds (mesocosms). To determine whether effects resulted from direct chlorpyrifos exposure or from disruption of the food web due to a pesticide-induced decline in zooplankton, we examined the impacts of chlorpyrifos on amphibian development in the presence of chlorpyrifos-resistant zooplankton, a key component of the aquatic trophic community...
October 2018: Environmental Toxicology and Chemistry
V M Emelyanov, N A Kalyuzhnyy, S A Mintairov, M Z Shvarts
Spectroscopic reflectometry was used within 700-1600 nm wavelength range to investigate dispersion curves for In0.06 Al0.94 As, In0.06 Al0.1 Ga0.84 As, and In0.06 Ga0.94 As layers, which constituted the purpose-made metamorphic InAlGaAs/GaAs Bragg reflector (BR). The procedure for determining the refractive index based on analyzing variations in cross-correlation coefficient obtained for reflection coefficient calculated and experimental dependences is presented. The sensitivity of the proposed method for variations in refractive index was investigated depending on the number of BR periods, the extinction coefficient of the layers of BR, and the wavelength range with respect to the main reflection maximum...
September 3, 2018: Optics Express
Henrik H Svensen, Sergei Frolov, Grigorii G Akhmanov, Alexander G Polozov, Dougal A Jerram, Olga V Shiganova, Nikolay V Melnikov, Karthik Iyer, Sverre Planke
On its way to the surface, the Siberian Traps magma created a complex sub-volcanic plumbing system. This resulted in a large-scale sill emplacement within the Tunguska Basin and subsequent release of sediment-derived volatiles during contact metamorphism. The distribution of sills and the released sediment-stored gas volume is, however, poorly constrained. In this paper, results from a study of nearly 300 deep boreholes intersecting sills are presented. The results show that sills with thicknesses above 100 m are abundant throughout the upper part of the sedimentary succession...
October 13, 2018: Philosophical Transactions. Series A, Mathematical, Physical, and Engineering Sciences
William K Milsom
The diversity of sites and surfaces that are utilized for gas transfer from air to blood in fish is remarkable. While a few species do utilize their gills for gas exchange in air, this is a rare occurrence and most air-breathing fish utilize other surfaces including air-breathing organs and lungs. At present almost nothing is known about the central sites that initiate and regulate air breathing although hypotheses can be put forward based on our rudimentary understanding of the sites involved in water breathing in lampreys and teleost fishes, and those involved in air breathing in pre-metamorphic anuran ampibians...
August 30, 2018: Acta Histochemica
Miroslav Klán, Petra Pokorná, David Havlíček, Ondřej Vik, Martin Racek, Jiří Plocek, Jan Hovorka
High concentrations of airborne asbestos in the ambient air are still a serious problem of air quality in numerous localities around the world. Since 2002, elevated concentrations of asbestos minerals of unknown origin have been detected in the ambient air of Pilsen, Czech Republic. To determine the asbestos fibre sources in this urban air, a systematic study was conducted. First, 14 bulk dust samples were collected in Pilsen at nine localities, and 6 bulk samples of construction aggregates for gravel production were collected in a quarry in the Pilsen-Litice district...
October 2018: Environmental Science and Pollution Research International
M V Yermokhin, N N Sushchik, V G Tabachishin, G S Kalacheva, A A Kolmakova, M I Gladyshev
The flow of long-chain polyunsaturated fatty acids (PUFAs) of the omega-3 family, namely, eicosapentaenoic acid (20:5n-3, EPA) and docosahexaenoic acid (22:6n-3, DHA), exported by amphibian metamorphs from water to terrestrial ecosystems in the Medveditsa River floodplain, was quantified for the first time. The total biomass export by three amphibian species (Pelobates fuscus, Bombina bombina, and Pelophylax ridibundus) per unit area of the lake surface was 0.594 g/m2 per year (as a mean for 2 years). The biomass flow per unit area of land was 0...
July 2018: Doklady. Biochemistry and Biophysics
Federico Lugli, Anna Cipriani, Valentina Tavaglione, Mirko Traversari, Stefano Benazzi
OBJECTIVES: In this work, we use Sr isotopes to analyze human hair and determine short-term movements of a contemporary human traveler and of early-modern individuals from an archaeological site (Roccapelago, Modena, Italy, 16th-18th century). MATERIALS AND METHODS: Analyses were performed using a Neptune MC-ICP-MS. We first set up and tested the procedure on scalp hair of a contemporary human, who spent some time between Brazil and Italy. We then analyzed the 87 Sr/86 Sr ratios of eight exceptionally well-preserved archaeological hair specimens associated with human mummies from Roccapelago...
August 29, 2018: American Journal of Physical Anthropology
Rose Upton, Simon Clulow, Michael J Mahony, John Clulow
Amphibians are the most threatened vertebrate class globally based on recent rates of decline and extinction. Sperm cryopreservation and other assisted reproductive technologies have the potential to help manage small and threatened populations and prevent extinctions. There are a growing number of reports of recovery of amphibian sperm after cryopreservation, but relatively few published reports of amphibian embryos generated from frozen sperm developing beyond metamorphosis to the adult stage and achieving sexual maturation...
2018: Conservation Physiology
Dong Cheng, Tingcai Cheng, Xi Yang, Quan Zhang, Jianfeng Fu, Tieshan Feng, Jiao Gong, Qingyou Xia
BACKGROUND: The silkworm, Bombyx mori, a typical representative of metamorphic insects, is of great agricultural and economic importance. The steroid hormone ecdysone (20-hydroxyecdysone, 20E) is the central regulator of insect developmental transitions, and its nuclear receptors are crucial for numerous biological processes, including reproduction, metabolism, and immunity. However, genome-wide DNA regulatory elements and the ecdysone receptor (EcR) that control these programs of gene expression are not well defined...
August 27, 2018: Epigenetics & Chromatin
Qiang Shi, Nailiang Sun, Honghong Kou, Hongyuan Wang, Hongfeng Zhao
Mercury is severely detrimental to organisms and is ubiquitous in both terrestrial and aquatic ecosystems. In the present study, we examined the effects of chronic mercury (Hg) exposure on metamorphosis, body size, thyroid microstructures, liver microstructural and ultrastructural features, and transcript levels of genes associated with lipid metabolism, oxidative stress and thyroid hormones signaling pathways of Chinese toad (Bufo gargarizans) tadpoles. Tadpoles were exposed to mercury concentrations at 0, 6, 12, 18, 24 and 30 µg/L from Gosner stage 26-42 of metamorphic climax...
August 23, 2018: Ecotoxicology and Environmental Safety
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