bluuebunny/crossref_metadata_2025_split huggingface dataset:
Identification of areas of very high biodiversity value to achieve the EU Biodiversity Strategy for 2030 key commitments
Authors: Miu Iulia V. , Rozylowicz Laurentiu , Popescu Viorel D. , Anastasiu Paulina 
Published: September 2020

Background
The European Union strives to increase protected areas of the EU terrestrial surface to 30% by year 2030, of which one third should be strictly protected. Designation of the Natura 2000 network, the backbone of nature protection in the EU, was mostly an expert-opinion process with little systematic conservation planning. The designation of the Natura 2000 network in Romania followed the same non-systematic approach, resulting in a suboptimal representation of invertebrates and plants. To help identify areas with very high biodiversity without repeating past planning missteps, we present a reproducible example of spatial prioritization using Romania’s current terrestrial Natura 2000 network and coarse-scale terrestrial species occurrence.

Methods
We used 371 terrestrial Natura 2000 Sites of Community Importance (Natura 2000 SCI), designated to protect 164 terrestrial species listed under Annex II of Habitats Directive in Romania in our spatial prioritization analyses (marine Natura 2000 sites and species were excluded). Species occurrences in terrestrial Natura 2000 sites were aggregated at a Universal Traverse Mercator spatial resolution of 1 km2. To identify priority terrestrial Natura 2000 sites for species conservation, and to explore if the Romanian Natura 2000 network sufficiently represents species included in Annex II of Habitats Directive, we used Zonation v4, a decision support software tool for spatial conservation planning. We carried out the analyses nationwide (all Natura 2000 sites) as well as separately for each biogeographic region (i.e., Alpine, Continental, Pannonian, Steppic and Black Sea).

Results
The results of spatial prioritization of terrestrial Natura 2000 vary greatly by planning scenario. The performance of national-level planning of top priorities is minimal. On average, when 33% of the landscape of Natura 2000 sites is protected, only 20% of the distribution of species listed in Annex II of Habitats Directive are protected. As a consequence, the representation of species by priority terrestrial Natura 2000 sites is lessened when compared to the initial set of species. When planning by taxonomic group, the top-priority areas include only 10% of invertebrate distribution in Natura 2000. When selecting top-priority areas by biogeographical region, there are significantly fewer gap species than in the national level and by taxa scenarios; thusly, the scenario outperforms the national-level prioritization. The designation of strictly protected areas as required by the EU Biodiversity Strategy for 2030 should be followed by setting clear objectives, including a good representation of species and habitats at the biogeographical region level.
Range extensions for the hidden-ear frog (Cyclorana cryptotis) and Main’s frog (Cyclorana maini) in the Davenport Murchison Ranges bioregion, Northern Territory
Authors: Clancy Matthew J. , Littlefair Etienne L. 
Published: September 2020

ABSTRACT
Anurans inhabiting Australia’s semi-arid and arid zones display eruptive breeding patterns. They emerge in large numbers to reproduce after significant rainfall before burrowing deep underground, where they remain concealed for extensive periods until favourable conditions return. This cryptic life history hinders documentation of the natural history and ecology of arid adapted amphibians of Australia. Fundamental information for some species such as geographic distribution thus remains uncertain. Here, we report range extensions for two species of Cyclorana. Cyclorana are a genus of 14 burrowing frog species that occupy arid, semi-arid and monsoonal regions of Australia. We document a 188 km southerly range extension of Cyclorana cryptotis, and an 88 km northerly extension for Cyclorana maini; both within the Davenport Murchison Ranges bioregion of the Northern Territory. Our observation of C. cryptotis is significant as it is the first record of the species in the Davenport Murchison Ranges bioregion.
Neural Control of Birdsong
Authors: Burke Jessica E , Schmidt Marc F 
Published: September 2020

AbstractIn songbirds, singing is a learned behaviour that displays a remarkable level of acoustic and temporal complexity. It is controlled by a well‐defined neural circuit, known as the song system, which receives highly processed auditory information from specialised higher‐order auditory areas. Over the past decade, sophisticated new song analysis tools coupled with the ability to actively record from and manipulate the activity of specific neural circuits in adult and juvenile singing birds have revealed many fundamental insights into the neural mechanisms that underlie vocal production, song acquisition and the storage of auditory memories. Some of these advances include an understanding of how sleep drives song learning and how circuits homologous to the mammalian basal ganglia generate the motor variability that enables sensorimotor learning. The tractable nature of this system along with its similarities to human speech make birdsong a unique model for understanding the neural bases of vocal production and motor learning.Key ConceptsSong is a behaviour whose acoustic and temporal features can be precisely quantified and used to track vocal learning.The song system is a specialised neural circuit that is necessary for song production and sensorimotor learning.Neurons in the descending motor pathway produce short (approximately 5 ms) bursts of action potentials that are time locked to specific time points in song, forming a sparse code that controls much of the song's acoustic and temporal structure.The portion of the song system necessary for song production is organised as a recurrent pathway with structures in the thalamus and respiratory brainstem projecting back up to the forebrain.Juvenile song is initially highly variable. With age, song becomes more stereotyped converging onto a stable ‘crystallised’ song. This form of learning requires both that the bird be exposed to a tutor song and be able to hear himself sing.Sleep plays an important role in song learning by allowing for offline rehearsal of motor commands both within the motor cortical pathway as well as in the syringeal muscles.The auditory forebrain processes auditory information necessary for song learning and likely contains the circuits responsible for storing the song template.Auditory feedback is necessary for song maintenance in adults and experimental manipulation of this feedback induces plasticity of the ‘crystallised’ adult song.The basal ganglia provide the source of the motor variability that allows for vocal exploration in both juvenile and adult songbirds.Dopaminergic inputs to the basal ganglia send performance evaluation signals that bias vocal exploration in an adaptive, feedback‐dependent direction. This circuit feature likely extends to other motor behaviours like learning to play a sport or an instrument.
Acetylcholine
Authors: Oliver Devyn , Francis Michael M 
Published: September 2020

AbstractFrom the discovery of ‘Vagusstoff’ (vagus substance) came a Nobel Prize and the sprouting of many neurological breakthroughs and insights into the chemical acetylcholine. Acetylcholine (ACh), a versatile synaptic compound, is evolutionarily conserved and present in all animals. The ancient role of acetylcholine in cell–cell communication and cellular modulation was expanded in metazoans to include neuron–neuron and neuro‐muscular signalling. ACh is widely expressed, present in the central nervous system (CNS), the peripheral nervous system (PNS) and in nonneuronal cells. Deficits in ACh‐mediated processes contribute to a variety of neuromuscular and neurodegenerative diseases, including myasthenia gravis and Alzheimer disease. Nicotine in tobacco products mimics acetylcholine's actions in the brain, causing nicotine dependence in smokers. The development of new experimental tools in the mammalian nervous system and studies of conserved mechanisms in invertebrate models have enhanced our understanding of acetylcholine function.Key ConceptsAcetylcholine is an evolutionarily conserved signalling molecule.Acetylcholine performs diverse functions in the central nervous system, peripheral nervous system and in nonneuronal cells.Nicotine, toxins and insecticides target parts of acetylcholine pathways.Dysfunctions in acetylcholine signalling underlie neuromuscular diseases such as myasthenia gravis and are associated with neurodegenerative diseases such as Alzheimer disease.Invertebrate model systems offer experimental strengths to address lingering questions about neuronal and non‐neuronal mechanisms of acetylcholine function.
Bacterial Plasmids
Authors: Thomas Christopher M , Summers David 
Published: September 2020

Abstract

Plasmids are nonessential genetic elements that can maintain accessory genetic information and facilitate infectious spread of the genes they carry. They regulate their own replication and transmission and were largely responsible for the proliferation of antibiotic resistance during the second half of the twentieth century.

Key Concepts

By definition, a plasmid is an autonomously replicating nonessential genetic element.

Plasmids are classified by the relatedness of their backbone functions which are responsible for replication, stable inheritance and transfer.

All plasmids encode a mechanism that inhibits plasmid replication when its copy number rises and the genes that achieve this can be inserted into a vector that can displace the plasmid by blocking its replication.

Natural plasmids have evolved a variety of systems to ensure that they are inherited stably including addiction systems that prevent growth of bacteria that lose the plasmid.

Many plasmids can spread from one bacterium to another by a replicative transfer process that donates a copy to the new cell while leaving at least one copy in the donor cell.

Plasmids can be pictured as cargo trains with the backbone functions represented as the engines that drive the system and different mobile DNA as the trucks that can join the engine and the phenotypic markers as the cargo carried by the trucks.
Phycology
Authors: Borowitzka Michael A 
Published: September 2020

Abstract

Phycology is the study of algae. However, just what algae are is difficult to define, because they belong to many different and diverse taxonomic groups and include both prokaryotic and eukaryotic representatives. Broadly speaking, the algae comprise all, mainly aquatic, plants and plant‐like chlorophyll
a
‐containing organisms that can use light energy to fix carbon from atmospheric carbon dioxide (CO
2
) and evolve oxygen, but which are not specialised land plants like mosses, ferns, coniferous trees and flowering plants. This is a negative definition, but it serves its purpose. Besides being a principal source of oxygen, algae are important primary producers in many, mainly aquatic, habitats. The prokaryotic Cyanobacteria are important as nitrogen fixers, converting N
2
to organic nitrogen. The algae are the source of a number of important commercial products and molecules and are also used in wastewater treatment, as animal feed and as fertilisers.

Key Concepts

Phycology is the study of algae.

The algae are a very diverse group of plants and plant‐like organisms, but which are not specialised land plants like mosses, ferns, coniferous trees and flowering plants.

The algae include both prokaryotic and eukaryotic organisms.

Algae are key providers of oxygen on earth and are the basis of aquatic food webs.

Algae have a wide range of commercial applications.

Endosymbiosis has played an important part in the evolution of the algae.
Synapsida (Extinct Mammal Relatives)
Authors: Sues Hans‐Dieter 
Published: September 2020

Abstract

In the phylogenetic system, the Synapsida include Mammalia and all other amniotes more closely related to Mammalia than to Reptilia. The most characteristic feature is the presence of a single large opening behind the orbit on either side of the skull. This opening is small in basal synapsids but increases in size in later, more derived forms including mammals. Nonmammalian synapsids form an extensive series of taxa that are successively more closely related to mammals and thus are now often referred to as stem‐mammals or ancient mammal relatives. They range from the Late Carboniferous to the Early Cretaceous. Crown‐group mammals (which include all present‐day mammals) are first known from the Middle Jurassic. Synapsida and Reptilia are now considered two entirely distinct evolutionary lineages of Amniota with a common ancestor in the Carboniferous.

Key Concepts

Synapsida is one of the two principal groups of Amniota.

Synapsida comprises mammals and all extinct taxa more closely related to mammals than to reptiles including birds.

Synapsids form a distinct evolutionary lineage from reptiles.

There was a gradual evolutionary acquisition of mammal‐like features during synapsid evolution.

The ear bones of mammals developed from the bones at the back of the lower jaw in their antecedents.
Taste: Cellular Basis
Authors: Roper Stephen D 
Published: September 2020

Abstract

Taste buds are the peripheral end organs of the gustatory system. Several thousand of these sensory organs are distributed throughout the oral cavity. Each taste bud consists of up to 100 cells that detect food chemicals and transmit this information to sensory afferent fibres that connect taste buds to the hindbrain. Individual taste buds detect many compounds, including those that elicit sweet, salty, bitter, sour, umami and perhaps other perceptions. There is no taste map on the tongue. Sensory receptor cells in taste buds transduce taste stimuli using G protein‐coupled taste receptors and ion channels. Gustatory stimulation causes the taste bud cells to secrete neurotransmitters, including ATP and serotonin, that excite sensory afferent fibres as well as mediate cell–cell (paracrine) interactions within a taste bud. Taste information travels from the hindbrain to cortical centres where the signals are integrated with olfaction to generate perception of flavours.

Key Concepts

Taste buds respond to chemical compounds found in foods and beverages.

Taste buds consist of many cells that are dedicated to sensing multiple tastes, including sweet, sour, salty, bitter and umami.

There is no taste map on the tongue.

Taste cells comprise a renewing cell population with taste cells having lifespans of 8–12 days.

There are 4 major types of cells in taste buds, each having a distinct function.

Gustatory stimulation causes taste bud cells to secrete ATP and serotonin.

Taste‐evoked ATP release is highly unusual: it is nonvesicular and involves secretion through large‐pore ion channels.

Cells within a taste bud communicate with each other during taste stimulation via paracrine synaptic interactions.

Gustatory signals transmitted to the brain cortex converge there with olfactory input to generate flavours.
Cell‐Free Vascular Grafts That Grow with the Host
Authors: Nasiri Bita , Row Sindhu , Smith Randall J. , Swartz Daniel D. , Andreadis Stelios T. 
Published: September 2020

AbstractCell‐free small diameter vascular grafts, based on small intestinal submucosa functionalized with heparin and vascular endothelial growth factor (VEGF) are manufactured and implanted successfully into the arterial system of neonatal lambs, where they remain patent and grow in size with the host to a similar extent and with similar rate as native arteries. Acellular tissue engineered vessels (A‐TEVs) integrate seamlessly into the native vasculature and develop confluent, functional endothelium that affords patency. The medial layer is infiltrated by smooth muscle cells, shows no signs of calcification, and develops contractile function. The vascular wall undergoes remarkable extracellular matrix remodeling exhibiting elastin fibers and even inner elastic lamina within six months. Taken together, the results suggest that VEGF‐based A‐TEVs may be suitable for treatment of congenital heart disorders to alleviate the need for repeated surgeries, which are currently standard practice.
Fundamentals and Applications of FluidFM Technology in Single‐Cell Studies
Authors: Saha Prithwidip , Duanis‐Assaf Tal , Reches Meital 
Published: September 2020

AbstractThis review describes the potential of FluidFM technology and its implementation in studying the interface between a single cell (prokaryote or eukaryote) and a surface or a surrounding area. A combination of microfluidics with conventional atomic force microscope (AFM) makes this platform efficient to address challenges associated with various biomolecular systems and biophysical activities down to single‐cell levels. Upon regulating the pressure through a microchanneled cantilever via a pressure controller, a wide range of studies are feasible. These include isolating and displacing a single living cell to measure the cell‐substrate and intercellular adhesion forces, intracellular injection of biomolecules as drug delivery systems, extraction of cellular fluid for downstream analyses, and characterization of cell structures to obtain the mechanical properties. For single‐cell adhesion experiments, the irreversible chemical‐based cell immobolization in conventional AFM has been replaced with the reversible pressure‐controlled approach in this platform; this not only reduces the experiment time—it also helps in performing serial and rapid measurement with improved statistics. This approach also ensures the retention of cell viability after each experiment.
Surface Patterning of Hydrogel Biomaterials to Probe and Direct Cell–Matrix Interactions
Authors: Munoz‐Robles Brizzia G. , Kopyeva Irina , DeForest Cole A. 
Published: September 2020

AbstractDue to their mechanical and structural similarity to native tissues, hydrogel biomaterials have gained tremendous popularity for applications in 3D tissue culture, therapeutic screening, disease modeling, and regenerative medicine. Recent advances in pre‐ and post‐synthetic processing have afforded anisotropic manipulation of the biochemical, mechanical, and topographical properties of biocompatible gels, increasingly in a dynamic and heterogeneous fashion that mimics natural processes in vivo. Herein, the current state of hydrogel surface patterning to investigate cellular interactions with the surrounding matrix is reviewed, both in techniques utilized and biological findings explored, and the perspective on proposed future directions for the field is offered.
α‐Funktionalisierung von Ketonen durch metallfreie elektrophile Aktivierung
Authors: Zawodny Wojciech , Teskey Christopher J. , Mishevska Magdalena , Völkl Martin , Maryasin Boris , González Leticia , Maulide Nuno 
Published: September 2020

AbstractDie durch Trifluormethansulfonsäureanhydrid vermittelte Aktivierung von Acetophenon führt zu außerordentlich elektrophilen Intermediaten, welche eine Vielzahl von Transformationen mit Nukleophilen eingehen können. Diese elektrophile Ketonaktivierung ermöglicht den Zugang zu α‐arylierten und α‐oxyaminierten Acetophenonen unter metallfreien Bedingungen in mittleren bis ausgezeichneten Ausbeuten und erweitert die Möglichkeiten zur Synthese von arylierten Morpholinen durch die Erzeugung von Vinylsulfoniumsalzen. Die Untersuchung der Reaktion am Computer bestätigte zudem das vorübergehende Vorhandensein von reaktiven Intermediaten, welche aus Vinyltrifluormethansulfonaten (Vinyltriflaten) enstehen, und die Rolle der Sauerstoffatome, welche in para‐Position des aromatischen Rings stehend diese stabilisieren.
Challenges and Opportunities in the Post‐Synthetic Modification of Interlocked Molecules
Authors: Waelès Philip , Gauthier Maxime , Coutrot Frédéric 
Published: September 2020

AbstractSeveral strategies have been successfully utilised to obtain a wide range of interlocked molecules. However, some interlocked compounds are still not obtained directly and/or efficiently from non‐interlocked components because the requisites for self‐assembly cannot always be enforced. To circumvent such a synthetic problem, a strategy that consists of synthesizing an isolable and storable interlocked building block in a step that precedes its modification is an appealing chemical route to more sophisticated interlocked molecules. Synthetic opportunities and challenges are closely linked to the fact that the mechanical bond might greatly affect the reactivity of a functionality of the encircled axle, but that the interlocked architecture needs to be preserved during the synthesis. Hence, the mechanical bond plays a fundamental role in the strategy employed. This Review focuses on the challenging post‐synthetic modifications of interlocked molecules, sometimes through cleavage of the axle's main chain, but always with conservation of the mechanical bond.
Nanomotors Sense Local Physicochemical Heterogeneities in Tumor Microenvironments**
Authors: Dasgupta Debayan , Pally Dharma , Saini Deepak K. , Bhat Ramray , Ghosh Ambarish 
Published: September 2020

AbstractThe invasion of cancer is brought about by continuous interaction of malignant cells with their surrounding tissue microenvironment. Investigating the remodeling of local extracellular matrix (ECM) by invading cells can thus provide fundamental insights into the dynamics of cancer progression. In this paper, we use an active untethered nanomechanical tool, realized as magnetically driven nanomotors, to locally probe a 3D tissue culture environment. We observed that nanomotors preferentially adhere to the cancer‐proximal ECM and magnitude of the adhesive force increased with cell lines of higher metastatic ability. We experimentally confirmed that sialic acid linkage specific to cancer‐secreted ECM makes it differently charged, which causes this adhesion. In an assay consisting of both cancerous and non‐cancerous epithelia, that mimics the in vivo histopathological milieu of a malignant breast tumor, we find that nanomotors preferentially decorate the region around the cancer cells.
Closed Shell Iron(IV) Oxo Complex with an Fe–O Triple Bond: Computational Design, Synthesis, and Reactivity
Authors: Andris Erik , Segers Koen , Mehara Jaya , Rulíšek Lubomír , Roithová Jana 
Published: September 2020

AbstractIron(IV)‐oxo intermediates in nature contain two unpaired electrons in the Fe–O antibonding orbitals, which are thought to contribute to their high reactivity. To challenge this hypothesis, we designed and synthesized closed‐shell singlet iron(IV) oxo complex [(quinisox)Fe(O)]+ (1+; quinisox‐H=(N‐(2‐(2‐isoxazoline‐3‐yl)phenyl)quinoline‐8‐carboxamide). We identified the quinisox ligand by DFT computational screening out of over 450 candidates. After the ligand synthesis, we detected 1+ in the gas phase and confirmed its spin state by visible and infrared photodissociation spectroscopy (IRPD). The Fe–O stretching frequency in 1+ is 960.5 cm−1, consistent with an Fe–O triple bond, which was also confirmed by multireference calculations. The unprecedented bond strength is accompanied by high gas‐phase reactivity of 1+ in oxygen atom transfer (OAT) and in proton‐coupled electron transfer reactions. This challenges the current view of the spin‐state driven reactivity of the Fe–O complexes.