How do authors' perceptions of their papers compare with co-authors' perceptions and peer-review decisions?

How do author perceptions match up to the outcomes of the peer-review process and perceptions of others? In a top-tier computer science conference (NeurIPS 2021) with more than 23,000 submitting authors and 9,000 submitted papers, we surveyed the authors on three questions: (i) their predicted probability of acceptance for each of their papers, (ii) their perceived ranking of their own papers based on scientific contribution, and (iii) the change in their perception about their own papers after seeing the reviews. The salient results are: (1) Authors had roughly a three-fold overestimate of the acceptance probability of their papers: The median prediction was 70% for an approximately 25% acceptance rate. (2) Female authors exhibited a marginally higher (statistically significant) miscalibration than male authors; predictions of authors invited to serve as meta-reviewers or reviewers were similarly calibrated, but better than authors who were not invited to review.

Calcitic Prisms of The Giant Seashell Pinna Nobilis Form Light Guide Arrays.

The shells of the Pinnidae family are based on a double layer of single-crystal-like calcitic prisms and inner aragonitic nacre, a structure known for its outstanding mechanical performance. However, on the posterior side, shells are missing the nacreous layer, which raises the question of whether there can be any functional role in giving up this mechanical performance. Here, it is demonstrated that the prismatic part of the Pinna nobilis shell exhibits unusual optical properties, whereby each prism acts as an individual optical fiber guiding the ambient light to the inner shell cavity by total internal reflection.

A Brief History of Biomineralization Studies.

Biomineralization is the process by which living organisms produce minerals. Although the term is recent (∼1970), the study of internal and external skeleton mineralization is older. This article describes the history of biomineralization studies.

Structure and Composition of the Eggshell of a Passerine Bird, (Linnaeus, 1758).

The mineral composition of eggshells is assumed to be a conserved phylogenetic feature. Avian eggshells are composed of calcite, whereas those of taxa within Chelonia are aragonitic. Yet, the eggshells of a passerine bird were reported to be made of aragonite.

Prism substructures in the shell of (Linnaeus, 1758), Mollusca - Evidence for a three-dimensional pulsed-growth model.

In the shells of the Pelecypods belonging to the Pinnidae family, the calcareous prismatic units of the outer layer are long-standing references for biomineralization studies. To elucidate how the mechanism of prism formation enables both shell elongation and thickness increase, a top-down structural analysis of these classical "simple prisms" has been carried out, taking advantage of shell sampling on actively mineralizing animals. Particular attention was paid to the morphological and structural patterns of the calcareous units sequentially produced at the margins of the growth lamellae.

Breaking the long-standing morphological paradigm: Individual prisms in the pearl oyster shell grow perpendicular to the c-axis of calcite.

Cross-sections of calcitic prismatic layers in mollusk shells, cut perpendicular to growth direction, reveal well-defined polygonal shapes of individual "grains" clearly visible by light and electron microscopy. For several kinds of shells, it was shown that the average number of edges in an individual prism approaches six during the growth process. Taking into account the rhombohedral symmetry of calcite, often presented in hexagonal axes, all this led to the long-standing opinion that calcitic prisms grow along the c-axis of calcite.

Biomineralization in modern avian calcified eggshells: similarity versus diversity.

Avian eggshells are composed of several layers made of organic compounds and a mineral phase (calcite), and the general structure is basically the same in all species. A comparison of the structure, crystallography, and chemical composition shows that despite an overall similarity, each species has its own structure, crystallinity, and composition. Eggshells are a perfect example of the crystallographic versus biological concept of the formation and growth mechanisms of calcareous biominerals: the spherulitic-columnar structure is described as "a typical case of competitive crystal growth", but it is also said that the eggshell matrix components regulate eggshell mineralization.

Structure and composition of Unio pictorum shell: arguments for the diversity of the nacroprismatic arrangement in molluscs.

Mollusc shells are complex organomineral structures, the arrangement and composition depending on the species. Most studies are dedicated to shells composed of an aragonite nacreous and a calcite prismatic layer, so the nacreous prismatic model based on Pinctada and Atrina-Pinna. Here, we studied the micro- and nanostructure, the mineralogy and composition of a nacroprismatic bivalve species: Unio pictorum.

A computational study on the role of noncovalent interactions in the stability of polymer/graphene nanocomposites.

Understanding the interaction between graphene and polymers is of essential interest when designing novel nanocomposites with reinforced mechanical and electrical properties. In this computational study, the interaction of pristine graphene (PG) and graphene oxide (GO) with a series of functional groups, representative of the functionalised buildings blocks occurring in different polymers, and attached to aliphatic and aromatic chains, is analyzed using dispersion-corrected semi-empirical methods (PM6-D3H4X) and density functional theory calculations with empirical dispersion corrections. Functional groups include alkyl, hydroxyl, aldehyde, carboxyl, amino and nitro groups, and the binding energies of these groups with graphene derivatives (PG and GO) are determined.

High-resolution structural and elemental analyses of calcium storage structures synthesized by the noble crayfish Astacus astacus.

During premolt, crayfish develop deposits of calcium ions, called gastroliths, in their stomach wall. The stored calcium is used for the calcification of parts of the skeleton regularly renewed for allowing growth. Structural and molecular analyses of gastroliths have been primarily performed on three crayfish species, Orconectes virilis, Procambarus clarkii, and more recently, Cherax quadricarinatus.

Calcium Deposits in the Crayfish, Cherax quadricarinatus: Microstructure Versus Elemental Distribution.

The crayfish Cherax quadricarinatus stores calcium ions, easily mobilizable after molting, for calcifying parts of the new exoskeleton. They are chiefly stored as amorphous calcium carbonate (ACC) during each premolt in a pair of gastroliths synthesized in the stomach wall. How calcium carbonate is stabilized in the amorphous state in such a biocomposite remains speculative.

Comparison of the structure, crystallography and composition of eggshells of the guinea fowl and graylag goose.

The structure and composition of the eggshells of two commercial species (guinea fowl and greylag goose) have been studied. Thin sections and scanning electron microcopy show the similarity of the overall structure, but the relative thickness of the layers differs in these two taxa. Atomic force microscopy shows that the different layers are composed of rounded, heterogeneous granules, the diameter of which is between 50 and 100 nm, with a thin cortex.

Electron microscope analyses of the bio-silica basal spicule from the Monorhaphis chuni sponge.

We report on a structural analysis of several basal spicules of the deep-sea silica sponge Monorhaphis chuni by electron microscope techniques supported by a precise focused ion beam (FIB) target preparation. To get a deeper understanding of the spicules length growth, we concentrated our investigation onto the apical segments of two selected spicules with apparently different growth states and studied in detail permanent and temporary growth structures in the central compact silica axial cylinder (AC) as well as the structure of the organic axial filament (AF) in its center. The new findings concern the following morphology features: (i) at the tip we could identify thin silica layers, which overgrow as a tongue-like feature the front face of the AC and completely fuse during the subsequent growth state.

Identifying predation on rodent teeth through structure and composition: A case from Morocco.

Predation by nocturnal birds of prey is one of the most frequent modes leading to the concentration of rodents in fossil assemblages. This mode of accumulation leaves characteristic surface alterations on bones and teeth. In order to evaluate and characterize the effects of these pre-diagenesis alterations on rodent fossil samples, we have carried out microstructural and chemical analyses on incisors collected from present day Moroccan wild animals and owl pellets.

Self-similar mesostructure evolution of the growing mollusc shell reminiscent of thermodynamically driven grain growth.

Significant progress has been made in understanding the interaction between mineral precursors and organic components leading to material formation and structuring in biomineralizing systems. The mesostructure of biological materials, such as the outer calcitic shell of molluscs, is characterized by many parameters and the question arises as to what extent they all are, or need to be, controlled biologically. Here, we analyse the three-dimensional structure of the calcite-based prismatic layer of Pinna nobilis, the giant Mediterranean fan mussel, using high-resolution synchrotron-based microtomography.

A perfectly periodic three-dimensional protein/silica mesoporous structure produced by an organism.

The discovery of perfectly ordered 3D mesoporous protein/silica structure in the axial filament of the marine sponge Monorhaphis chuni is reported. The structure belongs to body-centered tetragonal symmetry system (a=9.88 nm, c=10.

Unusual micrometric calcite-aragonite interface in the abalone shell Haliotis (Mollusca, Gastropoda).

Species of Haliotis (abalone) show high variety in structure and mineralogy of the shell. One of the European species (Haliotis tuberculata) in particular has an unusual shell structure in which calcite and aragonite coexist at a microscale with small patches of aragonite embedded in larger calcitic zones. A detailed examination of the boundary between calcite and aragonite using analytical microscopies shows that the organic contents of calcite and aragonite differ.

Synchrotron-based photoelectron spectroscopy provides evidence for a molecular bond between calcium and mineralizing organic phases in invertebrate calcareous skeletons.

Organic compounds have been extracted from calcium carbonate skeletons produced by three invertebrate species belonging to distinct phyla. The soluble parts of these skeleton matrices were isolated and analysed by synchrotron-based X-ray spectroscopy (XPS). The presence of calcium associated with these organic materials was revealed in every sample studied, with important variations in Ca 2p binding energy from species to species.

Control of aragonite deposition in colonial corals by intra-skeletal macromolecules.

Scleractinian coral skeletons are composed mainly of aragonite in which a small percentage of organic matrix (OM) molecules is entrapped. It is well known that in corals the mineral deposition occurs in a biological confined nucleation site, but it is still unclear to what extent the calcification is controlled by OM molecules. Hence, the shape, size and organization of skeletal crystals from the fiber level through the colony architecture, were also attributed to factors as diverse as nucleation site mineral supersaturation and environmental factors in the habitat.

Effect of structural defects and chemical functionalisation on the intrinsic mechanical properties of graphene.

Due to its unique mechanical properties, graphene can be applied for reinforcement in nanocomposites. We analyse the Young's modulus of graphene at the semi-empirical PM6 level of theory. The internal forces are calculated and the Young's modulus is predicted for a finite graphene sheet when external strain is applied on the system.

Biogenic calcite granules--are brachiopods different?

Brachiopods are still one of the least studied groups of organisms in terms of biomineralization despite recent studies indicating the presence of highly complex biomineral structures, particularly in taxa with calcitic shells. Here, we analyze the nanostructure of calcite biominerals, fibers and semi-nacre tablets, in brachiopod shells by high-resolution scanning electron microscopy (SEM) and atomic force microscopy (AFM). We demonstrate that basic mechanisms of carbonate biomineralization are not uniform within the phylum, with semi-nacre tablets composed of spherical aggregates with sub-rounded granules and fibers composed of large, triangular or rod-like particles composed of small sub-rounded granules (40-60 nm).

In situ distribution and characterization of the organic content of the oyster shell Crassostrea gigas (Mollusca, Bivalvia).

Cultivation of commercial oysters is now facing the possible influence of global change in sea water composition, commonly referred to as "ocean acidification". In order to test the potential consequence of the predicted environmental changes, a cultivation experiment was carried out. The left and right valves of the oyster shell Crassostrea gigas differ in their structure; moreover, lenses of non compact layers are irregular.

A high resolution analysis of the structure and chemical composition of the calcareous corpuscles from Mesocestoides corti.

Mesocestoides corti (syn. vogae), similar to many other cestode platyhelminthes, contains abundant calcium carbonate structures called calcareous corpuscles. These concretions that may constitute as much as 40% of the dry weight of the body, and were proposed to form intracellularly in certain parenchymal cells.

Shell layers of the black-lip pearl oyster Pinctada margaritifera: matching microstructure and composition.

The nacre-prism transition of the mollusc shell Pinctada margaritifera was studied using scanning electron microscopy, electron probe micro-analysis (EPMA) and time-of-flight secondary ion mass spectrometry (TOF-SIMS). Mineralogical change is correlated with a change in organic matrix. Previous analyses had shown that sugars were involved in the transition layer (fibrous aragonite).