Cytokinin Accumulation and an Altered Ethylene Response Mediate the Pleiotropic Phenotype of the Pea Nodulation Mutant R50 (\u3cem\u3esym16\u3c/em\u3e)

R50 (sym16), a pleiotropic mutant of Pisum sativum L., is short, has thickened internodes and roots, and has a reduced number of lateral roots and nodules. Its low nodule phenotype can be restored with the application of ethylene inhibitors; furthermore, it can be mimicked by applying cytokinins (CKs) to the roots of the parent line #8216;Sparkle’. Here, we report on the etiolation phenotypes of R50 and ‘Sparkle’, and on the interactive roles of ethylene and CKs in these lines. R50 displayed an altered etiolation phenotype, as it was shorter and thicker, and had more developed leaves than dark-grown ‘Sparkle’. Shoot morphological differences induced by exogenous ethylene or CKs were found to be less severe for R50. Ethylene inhibitor application induced root and shoot elongation and encouraged apical hook opening in both etiolated lines. Liquid chromatography–tandem mass spectrometry analysis indicated that CK concentrations in R50 were higher than in ‘Sparkle’, particularly in mature shoots where the levels were maintained at elevated concentrations. These differences indicate a reduction in the CK catabolism of R50. The accumulation of CKs can be directly related to several traits of R50, with the reduced number of nodules and altered shoot ethylene response being likely indirect effects

Feasibility study of a hand guided robotic drill for cochleostomy

The concept of a hand guided robotic drill has been inspired by an automated, arm supported robotic drill recently applied in clinical practice to produce cochleostomies without penetrating the endosteum ready for inserting cochlear electrodes. The smart tactile sensing scheme within the drill enables precise control of the state of interaction between tissues and tools in real-time. This paper reports development studies of the hand guided robotic drill where the same consistent outcomes, augmentation of surgeon control and skill, and similar reduction of induced disturbances on the hearing organ are achieved. The device operates with differing presentation of tissues resulting from variation in anatomy and demonstrates the ability to control or avoid penetration of tissue layers as required and to respond to intended rather than involuntary motion of the surgeon operator. The advantage of hand guided over an arm supported system is that it offers flexibility in adjusting the drilling trajectory. This can be important to initiate cutting on a hard convex tissue surface without slipping and then to proceed on the desired trajectory after cutting has commenced. The results for trials on phantoms show that drill unit compliance is an important factor in the design

Neural precursor cells derived from induced pluripotent stem cells exhibit reduced susceptibility to infection with a neurotropic coronavirus.

The present study examines the susceptibility of mouse induced pluripotent stem cell-derived neural precursor cells (iPSC-NPCs) to infection with the neurotropic JHM strain of mouse hepatitis virus (JHMV). Similar to NPCs derived from striatum of day 1 postnatal GFP-transgenic mice (GFP-NPCs), iPSC-derived NPCs (iPSC-NPCs) are able to differentiate into terminal neural cell types and express MHC class I and II in response to IFN-γ treatment. However, in contrast to postnatally-derived NPCs, iPSC-NPCs express low levels of carcinoembryonic antigen-cell adhesion molecule 1a (CEACAM1a), the surface receptor for JHMV, and are less susceptible to infection and virus-induced cytopathic effects. The relevance of this in terms of therapeutic application of NPCs resistant to viral infection is discussed

Common themes in nutrient acquisition by plant symbiotic microbes, described by the Gene Ontology

A critical function for symbionts is the acquisition of nutrients from their host. Relationships between hosts and symbionts range from biotrophic mutualism to necrotrophic parasitism, with a corresponding range of structures to facilitate nutrient flow between host and symbiont. Here, we review common themes among the nutrient acquisition strategies of a range of plant symbiotic microorganisms, including mutualistic symbionts, biotrophic pathogens that feed from living tissue, necrotrophic pathogens that kill host tissue, and hemibiotrophic pathogens that switch from biotrophy to necrotrophy. We show how Gene Ontology (GO) terms developed by the Plant-Associated Microbe Gene Ontology (PAMGO) Consortium can be used for describing commonalities in nutrient acquisition among diverse plant symbionts. Where appropriate, parallels found among animal symbionts are also highlighted

More Options, Fewer Students: Joint Physics and Chemistry Courses at Mount Royal University

Mount Royal University is a new University with only a few majors in the sciences. This limits the number of students interested in chemistry and physics courses and makes it difficult to run advanced courses in these areas. We have responded to this problem by designing joint courses in Thermodynamics, Quantum Mechanics, and Solid State that count for credit as either a chemistry course or a physics course. Students in the courses were interviewed in order to determine whether the difficulty level and balance of topics in the courses was appropriate. This short and tweet will discuss the design decisions and problems with a higher-level multidisciplinary course, as well as some feedback gleaned from student interviews. A newer joint course involving both nuclear science and policy studies will also be described briefly

THE ORIGIN OF \u3ci\u3eCHUBUTOLITHES\u3c/i\u3e IHERING, ICHNOFOSSILS FROM THE EOCENE AND OLIGOCENE OF CHUBUT PROVINCE, ARGENTINA

ABSTRACT-The distinctive trace fossil Chubutolithes gaimanensis n. ichnosp. occurs in Casamayoran (early Eocene) and Colhuehaupian (late Oligocene) alluvial rocks of the Sarmiento Formation in eastern Chubut Province, Argentina. Though known for nearly 70 years, its origin has remained obscure. Examination of new specimens and comparisons with modem analogs demonstrate that specimens of Chubutolithes represent the fossil nests of a mud-dauber (Hymenoptera: Sphecidae). Virtually identical nests are constructed today by mud-daubers in areas as disparate as southern Santa Cruz Province, Argentina, and Nebraska, confirming that quite similar trace fossils can be produced by several different taxa in a higher taxonomic clade. No satisfactory ethological term exists for trace fossils that, like Chubutolithes, were constructed by organisms above, rather than within, a substrate or medium. The new term aedificichnia is proposed. Chubutolithes occurs in alluvial paleosols and is associated with a large terrestrial ichnofauna. These trace fossils include the nests of scarab beetles, compound nests of social insects, and burrows of earthworms

A Monographic Revision Of The Genus \u3ci\u3eHoplopyga\u3c/i\u3e Thomson, 1880 (Coleoptera: Scarabaeidae: Cetoniinae: Gymnetini)

A comprehensive revision of the genus Hoplopyga Thomson, 1880 is presented. Eighteen species are redescribed, and two new species are described. A key for identification, distribution maps, and images of the 20 species are provided. Hoplopyga ruteri Antoine is removed from the genus and placed in junior synonymy with Macrocranius similis Schürhoff. Lectotypes are designated for Hoplopyga brasiliensis (Gory and Percheron), Hoplopyga corumbana Schürhoff, and Hoplopyga multipunctata (Gory and Percheron). The following new synonymies are established: Hoplopyga lucidiventris (Thomson) is Hoplopyga foeda (Schaum); Hoplopyga spurca (Janson) is Hoplopyga liturata (Olivier); Hoplopyga monacha (Gory and Percheron) and Hoplopyga rubida (Gory and Percheron) are Hoplopyga singularis (Gory and Percheron). Hoplopyga pseudomiliaris Shaughney and Ratcliffe from Guatemala and Hoplopyga riparia Shaughney and Ratcliffe from Peru and Brazil are described as new species