Second world record for two Calvatia species (Agaricaceae: Basidiomycota)

Calvatia is a genus of gasteroid fungi, comprising about 47 species worldwide. In this paper we report the second worldwide occurrence of two poorly known species of Calvatia, recorded in the Cerrado biome of Brazil: C. oblongispora and C. nodulata. Detailed morphological descriptions and illustrations, including scanning electron micrographs of hyphae and basidiospores are provided, as well a discussion on their taxonomy and geographic distribution.

William K. Ovalle PhD, Patrick C. Nahirney PhD Netter's Essential Histology: With Correlated Histopathology (Netter Basic Science) 3rd Edition

With strong correlations between gross anatomy and the microanatomy of structures, Netter’s Essential Histology, 3rd Edition, is the perfect text for today’s evolving medical education. Concise and easy to use, it integrates gross anatomy and embryology with classic histology slides and state-of-the-art scanning electron microscopy, offering a clear, visual understanding of this complex subject. Additional histopathology images, more clinical boxes, and new histopathology content ensure that this textbook-atlas clearly presents the most indispensable histologic concepts and their clinical relevance.Helps you recognize both normal and diseased structures at the microscopic level with the aid of succinct explanatory text as well as numerous clinical boxes. Features more histopathology content and additional clinical boxes to increase your knowledge of pathophysiology and clinical relevance. Includes high-quality light and electron micrographs, including enhanced and colorized electron micrographs that show ultra-structures in 3D, side by side with classic Netter illustrations that link your knowledge of anatomy and cell biology to what is seen in the micrographs. Provides online access to author-narrated video overviews of each chapter, plus Zoomify images and Virtual Slides that include histopathology and can be viewed at different magnifications.

Geometric frustration in the myosin superlattice of vertebrate muscle

Geometric frustration results from an incompatibility between minimum energy arrangements and the geometry of a system, and gives rise to interesting and novel phenomena. Here, we report geometric frustration in a native biological macromolecular system---vertebrate muscle. We analyse the disorder in the myosin filament rotations in the myofibrils of vertebrate striated (skeletal and cardiac) muscle, as seen in thin-section electron micrographs, and show that the distribution of rotations corresponds to an archetypical geometrically frustrated system---the triangular Ising antiferromagnet. Spatial correlations are evident out to at least six lattice spacings. The results demonstrate that geometric frustration can drive the development of structure in complex biological systems, and may have implications for the nature of the actin--myosin interactions involved in muscle contraction. Identification of the distribution of myosin filament rotations with an Ising model allows the extensive results on the latter to be applied to this system. It shows how local interactions (between adjacent myosin filaments) can determine long-range order and, conversely, how observations of long-range order (such as patterns seen in electron micrographs) can be used to estimate the energetics of these local interactions. Furthermore, since diffraction by a disordered system is a function of the second-order statistics, the derived correlations allow more accurate diffraction calculations, which can aid in interpretation of X-ray diffraction data from muscle specimens for structural analysis.

Low kindlin-3 levels in osteoclasts of kindlin-3 hypomorphic mice result in osteopetrosis due to leaky sealing zones

Osteoclasts form special integrin-mediated adhesion structures called sealing zones that enable them to adhere to and resorb bone. Sealing zones consist of densely packed podosomes tightly inter-connected by actin fibers. Their formation requires the presence of the hematopoietic integrin regulator kindlin-3. In this study, we investigated osteoclasts and their adhesion structures in kindlin-3 hypomorphic mice expressing only 5-10% of kindlin-3. Low kindlin-3 expression reduces integrin activity, results in impaired osteoclast adhesion and signaling, and delays cell spreading. Despite these defects, in vitro generated kindlin-3-hypomorphic osteoclast-like cells arrange their podosomes into adhesion patches and belts but their podosome and actin organization is abnormal. Remarkably, kindlin-3-hypomorphic osteoclasts form sealing zones when cultured on calcified matrix in vitro and on bone surface in vivo. However, functional assays, immunohistochemical staining and electron micrographs of bone sections showed that they fail to seal the resorption lacunae properly, which is required for secreted proteinases to digest bone matrix. This results in mild osteopetrosis. Our study reveals a new, hitherto understudied function of kindlin-3 as an essential organizer of integrin-mediated adhesion structures, such as sealing zones.

Foraminiferal art through the ages

ABSTRACT Foraminifera are single-celled organisms with and without shells (tests). They have an abundant fossil record over the past 545 million years and presence in modern oceans. The art of forams is dominated by hand-drawn scientific illustrations to scanning electron microscopic images done over the past 455 years, providing vital knowledge about shelled forams. From 1665 to 1835, forams were assigned to micro-invertebrates rather than single-celled forms. With more than 75,000 publications and nearly 50,000 described species of forams, illustrations must number more than 200,000. The illustrations include a range from simple line drawings through shaded ink and pencil renderings, sometimes even colored, to photographs and scanning electron micrographs. Forams also appear in other art forms: The Pyramids at Giza in Egypt, hand-sized models, jewelry, flooring, stamps, coins, sculptures, and a Chinese Foraminiferal Sculpture Park. Foraminiferal art, although very abundant in many forms, has not caught the attention of many people outside of foraminiferology.

A new species of Tinna (Hemiptera: Heteroptera: Reduviidae) from Nigeria

Tinna schoenitzeri sp. nov. (Hemiptera: Heteroptera: Reduviidae: Emesinae: Leistarchini) is described from Nigeria. Digital macrophotographs and scanning electron micrographs of the new species are given.

A revision of the genus Pachyrhinus Schӧnherr 1823 (Coleoptera: Curculionidae, Entiminae) in the Nearctic Region

The North American species of the broad-nosed weevil genus Pachyrhinus Schönherr 1823 (Coleoptera: Curculionidae, Entiminae) are revised. Three species of Pachyrhinus are here recognized in North America: P. elegans (Couper 1865), P. californicus (Horn 1876), and P. cinereus (Casey 1888). Pachyrhinus lateralis (Casey 1888) and P. miscix (Fall 1901) are here designated as synonyms of P. elegans. Pachyrhinus crassicornis (Casey 1888) and P. albidus (Fall 1901) are here designated synonyms of P. cinereus (Casey 1888) The previously proposed synonymy of P. ferrugineus (Casey 1888) with P. californicus was confirmed. This revision includes detailed images of diagnostic characters as well as scanning electron micrographs of scale morphology for all species. A key to the Nearctic species of Pachyrhinus is provided. All Nearctic species of Pachyrhinus are considered minor pests of Pinus spp. [Pinaceae].

Studies in Oberonia, 9: Lessons from excess names in Oberonia for Orchidaceae systematics, including a revision of the Oberonia Sect. Scytoxiphium

The reasons for excess names in microfloral orchids such as Oberonia Lindl. can be traced to poor scholarship (e.g., failure to review the literature, ignoring expert advice), typological thinking, and erroneous assumption of microendemism. Some extraordinarily poor descriptions, including some from the 21st century, can be termed “taxonomic vandalism”. The outdated reliance on drawings as opposed to z-stacked photographs and scanning electron micrographs poses further problems due to an abundance of demonstrable problems with drawings. The Oberonia sect. Scytoxiphium Schltr. with eight described species is reduced to one species, Oberonia heliophila Rchb.f.; it is illustrated by original drawings, live photographs and scanning electron microscope images. The distribution is extended from Java through Micronesia and Samoa. The species occurs predominantly from 0–500 m, less frequently to 900 m, and possibly to even 1900 m. It flowers throughout the year. Keywords/Palabras clave: Oberonia, Oberonia sect. Scytoxiphium, revision, revisión, synonymies, sinonimias, taxonomic vandalism, vandalismo taxonómico

Micrarchaeota are covered by a proteinaceous S-Layer

In previous publications, it was hypothesized that Micrarchaeota cells are covered by two individual membrane systems. This study proofs that at least the recently cultivated “Candidatus Micrarchaeum harzensis A_DKE” possesses an S-layer covering its cytoplasmic membrane. The potential S-layer protein was found to be among the proteins with the highest abundance in A_DKE and in silico characterization of its primary structure indicated homologies to other known S-layer proteins. Homologs of this protein were found in other Micrarchaeota genomes, which raises the question, whether the ability to form an S-layer is a common trait within this phylum. The S-layer protein seems to be glycosylated and the Micrarchaeum expresses genes for N-glycosylation under cultivation conditions, despite not being able to synthesize carbohydrates. Electron micrographs of freeze-etched samples of a previously described co-culture, containing Micrarchaeum A_DKE and a Thermoplasmatales member as its host organism, verified the hypothesis of an S-layer on the surface of A_DKE. Both organisms are clearly distinguishable by cell size, shape and surface structure.

Computational analysis of the effects of nitrogen source and sin1 knockout on biosilica morphology in the model diatom Thalassiosira pseudonana

Morphogenesis of the silica based cell walls of diatoms, a large group of microalgae, is a paradigm for the self-assembly of complex 3D nano- and microscale patterned inorganic materials. In recent years, loss-of-function studies using genetic manipulation were successfully applied for the identification of genes that guide silica morphogenesis in diatoms. These studies revealed that the loss of one gene can affect multiple morphological parameters, and the morphological changes can be rather subtle being blurred by natural variations in morphology even within the same clone. Both factors severely hamper the identification of morphological mutants using subjective by-eye inspection of electron micrographs. Here we have developed automated image analysis for objectively quantifying the morphology of ridge networks and pore densities from numerous electron micrographs of diatom biosilica. This study demonstrated differences in ridge network morphology and pore density in diatoms growing on ammonium rather than nitrate as the sole nitrogen source. Furthermore, it revealed shortcomings in previous by-eye evaluation of the biosilica phenotype of the silicanin-1 knockout mutant. We anticipate that the computational methods established in the present work will be invaluable for unraveling genotype–phenotype correlations in diatom biosilica morphogenesis.