bluuebunny/crossref_metadata_2025_split huggingface dataset:
A multiobjective short‐term optimal operation model for a cascade system of reservoirs considering the impact on long‐term energy production
Authors: Xu Bin , Zhong Ping‐An , Stanko Zachary , Zhao Yunfa , Yeh William W.‐G. 
Published: April 2015

AbstractThis paper examines the impact of short‐term operation on long‐term energy production. We propose a multiobjective optimization model for the short‐term, daily operation of a system of cascade reservoirs. The two objectives considered in the daily model are: (1) minimizing the total amount of water released and (2) maximizing the stored energy in the system. Optimizing short‐term operation without considering its impact on long‐term energy production does not guarantee maximum energy production in the system. Therefore, a major goal of this paper is to identify desirable short‐term operation strategies that, at the same time, optimize long‐term energy production. First, we solve the daily model for 1 month (30 days) using a nondominated genetic algorithm (NSGAII). We then use the nondominated solutions obtained by NSGAII to assess the impact on long‐term energy production using a monthly model. We use historical monthly inflows to characterize the inflow variability. We apply the proposed methodology to the Qingjiang cascade system of reservoirs in China. The results show: (1) in average hydrology scenarios, the solution maximizing stored energy produces the most overall long‐term energy production; (2) in moderately wet hydrology scenarios, the solution minimizing water released outperforms the maximizing stored energy solution; and (3) when extremely wet hydrology scenarios are expected, a compromise solution is the best strategy.
Protein Folding in Vivo
Authors: Georgescauld Florian , Hartl Franz‐Ulrich 
Published: April 2015

AbstractProteins are composed of linear chains of amino acids. Upon synthesis in the cell, most proteins must rapidly acquire a specific three‐dimensional structure, a process known as folding, before they can perform their various biological functions. Productive folding is often competed by aggregation, owing to the high macromolecular crowding of the cellular environment. Moreover, the process of translation increases the danger of misfolding, as incomplete nascent polypeptides are not yet able to fold into stable structures in many cases. To avoid these off‐pathway reactions, a class of proteins called molecular chaperones has evolved in all organisms. They interact with nascent or stress‐denatured polypeptides, prevent their aggregation and assist in folding and assembly processes, often in an ATP‐regulated manner. These functions are especially important in conditions of cell stress, and their failure is linked with the manifestation of numerous age‐dependent degenerative diseases.Key ConceptsMolecular chaperones are proteins that mediate folding and assembly of other proteins, without being components of the final folded or assembled structures.Molecular chaperones prevent the potentially toxic aggregation of newly synthesised polypeptides during translation and when mature proteins unfold during stress conditions or ageing.Hsp70 chaperones act as a hub in the proteostasis network by assisting protein folding and conformational maintenance and by distributing client proteins to other chaperones for correct folding.The chaperonins mediate the folding of proteins with complex topologies and kinetically frustrated folding pathways.
Mammalian Embryo:HoxGenes
Authors: Nolte Christof , Alexander Tara B , Krumlauf Robb 
Published: April 2015

AbstractHoxgenes are evolutionarily conserved transcription factors that play important roles in establishing the basic body plan of animals. Mammals have 39Hoxgenes clustered into four chromosomal complexes. This gene family regulates the regional character and patterning of diverse structures along the anterior–posterior (A/P) axis of the embryo. Nested patterns ofHoxgene expression generate a Hox combinatorial protein code that orchestrates the morphogenesis of structures in the nervous system, axial skeleton, limbs, intestine and many other tissues. In light of their key role in regulating morphogenesis across animal species, modulation ofHoxexpression or function over the course of evolution is believed to have been important in generating diversity.Key ConceptsAxial patterning is the process that generates different regional characteristics during the development of a tissue, such as the nervous system or skeleton.Hoxgenes encode a family of transcription factors that regulate the identity of structures along the anterior–posterior (A/P) axis of embryos.Co‐linearity is the correlation between the order ofHoxgenes along a chromosome and their expression along the axis of an embryo.The collection of Hox proteins expressed in a region provides a combinatorial code for specifying diversity.Posterior prevalence is a model for explaining why some Hox proteins dominate over others when they are co‐expressed.Selector genes control the identity of a tissue.Homeotic transformation is the conversion of one structure into another due to loss or gain of selector gene activity.Segmentation subdivides a developing tissue, such as the hindbrain or skeleton, into repeating units that ultimately generate different structures along an axis.Subfunctionalisation is the partitioning of function and regulation between duplicated genes compared with the ancestral gene.Changes inHoxexpression or function may be important for generating differences in structures during evolution of vertebrates.Cooption refers to the redeployment or coupling of a common molecular pathway to multiple patterning processes.
Astroviruses
Authors: Schultz‐Cherry Stacey 
Published: April 2015

Abstract

Astroviruses are positive‐sense, single‐stranded RNA viruses encoding three open reading frames. However, the exact number of processed proteins remains unknown. Originally identified as a common cause of childhood diarrhoea, especially in children under 2 years of age, astroviruses are now recognised as an infection of diverse mammals and birds. Disease can range from asymptomatic to mild, self‐limiting gastroenteritis, as well as nephritis, hepatitis and encephalitis in certain host species. Astrovirus pathogenicity and immune response is only poorly characterised and may differ between mammalian and avian species. Given the wide host range and extensive genetic diversity among species, it is not surprising that classifying astrovirus family members remains a challenge. In this article, the current knowledge of astroviruses is reviewed, including their replication, viral evolution, pathogenesis and immune response.

Key Concepts

The
Astroviridae
are a complex family of emerging viruses.

Astrovirus pathogenesis and host immune responses remain an underexplored area of investigation.

Astroviruses may be more prevalent in humans than previously recognised.

Astroviridae
classification and nomenclature for newly identified genotypes are needed.

Astroviruses are associated with more than gastroenteritis.
Zebrafish as an Experimental Organism
Authors: Bielen Holger 
Published: April 2015

Abstract

Over the last 20 years, the popularity of the zebrafish model has grown more rapidly than any other vertebrate model, and by now the zebrafish is used for virtually all disciplines of biological and medical research. New sophisticated advances in gene editing, transgenesis, 3D‐imaging and behavioural assay design have been established successfully and complemented the ‘tool box’ to make the zebrafish one of the most powerful vertebrate model organisms. There is now information available on expression of over 12 000 genes and about 1000 mutant phenotypes. The latest high‐quality sequence assembly of the zebrafish genome allows in‐depth comparative genomic analysis which will further enhance the use of zebrafish as a model for human diseases. Together with the previously established techniques such as forward genetics, cell‐transplantation, ‐ablation and ‐extraction, which can now be used for new generation sequencing analysis with temporal‐spatial precision, the zebrafish provides an outstanding
in vivo
vertebrate model to study development and human disease.

Key Concepts

The advantages of the zebrafish model include rapid development, short generation time, large number of offspring and transparency of the embryos

The zebrafish has become an excellent genetic model organism, amenable to forward genetic screens, targeted mutagenesis and efficient transgenesis

Using the zebrafish as a research model for developmental biology, regeneration, chemical screens and disease will expand our knowledge in basic and clinical research
D
e
G
raaf,
R
egnier
Authors: van Ruler Han 
Published: April 2015

Abstract
Regnier de Graaf (1641–1673) was a Dutch anatomist, experimental physiologist and innovative theorist, who received his medical training at Leiden University during a particularly creative period of methodological improvements in the field. Continuing his physiological studies even as a practitioner in Delft, de Graaf personally cultivated a scientific attitude to medical and biological questions that would bring him lasting fame, especially for his description of the female reproductive organs and his interpretation of the nature of mammalian ovaries. The term ‘Graafian follicle’, which stands for a mature ovarian follicle containing a ripened ovum, is derived from his name.
Hemichordates: Development
Authors: Miyamoto Norio , Wada Hiroshi 
Published: April 2015

AbstractHemichordates are marine invertebrates consisting of two distinct groups: the solitary enteropneusts, or acorn worms (comprising a few hundred species), and the colonial and tube‐dwelling pterobranchs (comprising 20 or so species). Phylogenetically, hemichordates are the sister group to echinoderms, together composing the Ambulacraria, and share some features with chordates. Hemichordates are thus considered key organisms for addressing the origins of deuterostome and chordate body plans. Unlike the other deuterostome models including echinoderms and chordates, however, information about the developmental biology of this group is limited. Recent improvements in the accessibility of embryos, functional tool development and genomic resources from several model organisms have yielded important information on the cellular and genetic mechanisms of embryogenesis and organogenesis in hemichordates. Comparisons of hemichordates and other deuterostomes permit identification of the common ancestor of deuterostomes and help elucidate the origin of the chordate body plan.Key ConceptsHemichordate developmental biology is key to elucidating the origin of chordates and the early evolution of deuterostomes.Descriptive and comparative studies using novel model species provide new insights into hemichordate evolution and diversity.Establishment of genetic resources and experimental methods drive the molecular developmental biology of hemichordates.Hemichordates and chordates show a conserved anteroposterior patterning mechanism.Hemichordate research indicates that inversion of the dorsoventral axis occurred in the chordate lineage.Gill slits of hemichordates and chordates are almost certainly homologous.The stomochord of hemichordates and the notochord of chordates share some genetic features, but are unlikely to be homologous.The origin of the tubular nervous system predates the diversification of hemichordates and chordates, but the homology of the collar nerve cord and neural tube still requires resolution.
Obesity: Genetics
Authors: Grant Struan FA , McCormack Shana E 
Published: April 2015

Abstract

Obesity is a disorder of energy balance. In obese individuals, there is excess body fat accumulation, which can lead to myriad health problems. The dysregulation of energy intake (appetite) and energy expenditure (activity) in obesity remains incompletely understood, but studies in humans and in model systems clearly demonstrate a strong genetic component to this condition. Within the past decade, major progress has been made in characterising the genetic component of obesity, with genome‐wide association studies revealing the most loci, including identifying the strongest association signal harboured within the
FTO
gene. Such studies have thus provided greater insight into the aetiology of this complex trait and are aiding in making diagnostic and therapeutic inroads into this common health concern.

Key Concepts

Obesity is characterised by an accumulation of excess adipose tissue that has myriad adverse health effects in virtually every organ system.

The rising global prevalence of obesity, particularly in developing nations and in children, is worrisome and incompletely understood.

Despite clear environmental contributions to disease risk, obesity is highly heritable.

In so‐called ‘syndromic’ genetic forms of obesity, genetic changes lead to obesity along with involvement of other organ systems. In ‘non‐syndromic’ obesity, genetic changes lead to an obesity‐predominant phenotype. Animal models of these conditions have led to important insights on the hypothalamic control of appetite.

Technological advances have led to the ability to perform genome‐wide association studies and identify novel genes and pathways related to obesity.

The complex interaction between genetics/epigenetics and myriad factors including the microbiome, diet/environment, physical activity and circadian rhythm may hold clues as to what individualised therapeutics may improve prevention and treatment of this highly morbid condition.
C
harles
B
.
D
avenport
Authors: Sohasky Kate E 
Published: April 2015

Abstract
Charles Benedict Davenport (1866–1944) was one of the most prominent public figures of the eugenics movement in the early decades of the twentieth century in the United States. Trained as a morphologist, biologist and geneticist, he is most remembered for his eugenic studies. Under his direction of Cold Spring Harbor Laboratory on Long Island, New York, the research conducted by the laboratory's Eugenics Record Office supported the early eugenics movement by serving as the leading repository of eugenic information and as a primary centre for the training of eugenic field workers.
DNA
Methylation: Enzymology
Authors: Jurkowska Renata Z , Jeltsch Albert 
Published: April 2015

Abstract

Methylated bases (C5‐methylcytosine, N4‐methylcytosine and N6‐methyladenine) are found in the DNA of most species, where they play important biological roles. There exist two families of DNA methyltransferases with specificity for methylation of the C5 position of cytosine or exocyclic amino groups of cytosine or adenine. They all use
S
‐adenosyl‐l‐methionine as the methyl group donor and contain a catalytic domain with a similar fold. In bacteria, methylation of DNA is used to distinguish self and foreign DNA, to direct post‐replicative mismatch repair, co‐ordinate DNA replication and cell cycle and for regulation of gene expression. In vertebrates, DNA methylation is established by three DNA methyltransferases (Dnmt1, Dnmt3a and Dnmt3b) in a cell‐type‐specific pattern, mainly at the CG sites. It functions as an epigenetic mark and is involved in the regulation of chromatin accessibility in many biological contexts. Bacterial DNA methyltransferases are mainly directed by the DNA sequence of their target site, whereas mammalian and plant Dnmts are recruited and regulated by several factors and other epigenetic signals, including modification of histone tails or RNA molecules.

Key Concepts

DNA methylation adds information to the DNA that is not encoded in the DNA sequence.

DNA methyltransferases use AdoMet as methyl group donor and flip their target base out of the DNA helix.

DNA methylation in bacteria reflects the sequence specificity of the bacterial methyltransferases, whereas eukaryotic enzymes are targeted and regulated by a network of different mechanisms.

Maintenance of mammalian DNA methylation patterns is mainly encoded in the palindromic nature of the CG site and is coupled to DNA replication.

Eukaryotic DNA methyltransferases are recruited by specific histone modifications generating a network of interconnected epigenetic signals.
Microtubule Plus‐End‐Tracking Proteins
Authors: Pereira Ana L , Maiato Helder 
Published: April 2015

Abstract

Microtubules are dynamic cytoskeletal components necessary for several intracellular processes, including cell division, differentiation, migration and intracellular transport. Microtubule plus‐end‐tracking proteins (+TIPs) consist of a highly diversified group of evolutionary conserved families of proteins that preferentially accumulate at the plus‐ends of microtubules. Importantly, +TIPs are capable of interacting with each other, which allows the establishment of complex protein networks greatly implicated in the regulation of microtubule behaviour. These networks play an important role mediating the interactions between microtubules and several cellular structures, such as membranes, kinetochores and the actin cytoskeleton, thereby influencing cellular architecture and coordinating diverse biological processes. For these reasons, +TIPs have been extensively studied, including the peculiar structural features allowing for the generation of networks, the mechanisms behind microtubule plus‐end‐tracking and their respective roles in the cell.

Key Concepts

+TIPs consist of an evolutionarily conserved, yet highly diversified group of proteins that preferentially accumulate at the plus‐end of microtubules regulating their dynamics.

In their structure +TIPs can comprise specialized domains fit to directly interact with tubulin, or able to bind proteins capable of autonomously associating with tubulin.

The establishment of +TIPs networks responsible for the regulation of microtubule dynamics is important for numerous biological processes in interphase and mitosis.
Synthesis of (−)‐Deoxynupharidine by Allenic Hydroxylamine Cyclisation
Authors: Bates Roderick W. , Lim Chia Juan , Collier Steven J. , Sukumaran Joly 
Published: April 2015

Abstract(−)‐Deoxynupharidine has been synthesised via an intermediate that can also be used for other Nuphar alkaloids. Significant steps include the optimised enzymatic resolution of an allenic alcohol, highly diastereoselective silver‐catalysed cyclisation of an allenic hydroxylamine, selective cross‐metathesis, diastereoselective intramolecular reductive amination, and stereoelectronically controlled enolate alkylation.
Strategy for Internal Labeling of Large RNAs with Minimal Perturbation by Using Fluorescent PNA
Authors: Schmitz Anita G. , Zelger‐Paulus Susann , Gasser Gilles , Sigel Roland K. O. 
Published: April 2015

AbstractFluorescence techniques for the investigation of biomolecules and their folding pathways require an efficient labeling strategy. A common method to internally label large RNAs involves the introduction of long loops for hybridization of fluorophore‐carrying DNA strands. Such loops often disturb the structure, and thus the functionality, of the RNA. Here we show, in a proof of concept study with a >600 nucleotide group II intron ribozyme, that the usage of the nucleic acid analogue peptide nucleic acid (PNA) is more efficient in several aspects, minimizing the required structural modifications of the RNA. We demonstrate by various methods, including smFRET, that much smaller concentrations and shorter PNAs can be applied, compared to DNA, for rapid and specific internal RNA labeling. The folding pathway and catalytic activity of this large ribozyme is only minimally affected by the PNA, but the background signal is significantly reduced.
Thermally Stabilized Cobalt‐Based Fischer–Tropsch Catalysts by Phosphorous Modification of Al2O3: Effect of Calcination Temperatures on Catalyst Stability
Authors: Woo Min Hee , Cho Jae Min , Jun Ki‐Won , Lee Yun Jo , Bae Jong Wook 
Published: April 2015

AbstractA phosphorous‐modified Al2O3 support was prepared by the impregnation method and applied for the preparation of cobalt‐based Fischer–Tropsch synthesis (FTS) catalysts (Co/P–Al2O3), which were calcined at different temperatures. The Co/P–Al2O3 showed a significant increase of thermal stability with a higher catalytic performance without severe deactivation even above a calcination temperature of 600 °C compared with the unmodified Co/Al2O3. These findings are explained by the suppressed cobalt aluminate formation and less pronounced aggregation of cobalt particles. The suppressed aggregation of cobalt particles is attributed to the localized presence of aluminum phosphate by forming a thermally stable metal–phosphorous oxo‐species on Al2O3 surfaces thus suppressing the migration of cobalt particles to the outer pore mouths of the support. These effects significantly enhance the catalytic activity with a higher thermal stability of the catalysts.
Recent Progress in Non‐Platinum Counter Electrode Materials for Dye‐Sensitized Solar Cells
Authors: Theerthagiri Jayaraman , Senthil Arumugam Raja , Madhavan Jagannathan , Maiyalagan Thandavarayan 
Published: April 2015

AbstractDye‐sensitized solar cells (DSSCs) have gained increasing attention with regard to photovoltaic devices, because of their low cost and simple fabrication methods; they are mostly investigated in indoor light‐harvesting and portable applications. The focus has been on three main parameters of photovoltaic devices, that is, lifetime, and cost effectiveness. A DSSC consists of four prominent components including a photoanode, a photosensitizer, a redox electrolyte, and a counter electrode. The counter electrode is a crucial component, in which triiodide is reduced to iodide by electrons flowing through the external circuit. An effective approach to improve the performance of a counter electrode is to enhance the power conversion efficiency and to reduce the cost of the device. Platinum‐coated conducting glass electrodes give the best performance, but their high cost and the scarcity of platinum restricts large‐scale application in DSSCs. This has prompted researchers to develop low‐costing platinum‐free electrodes for DSSCs. In this review, we focus mainly on counter electrode materials for the electrocatalytic redox reaction for the I−/${{\rm{I}}_{\rm{3}}^ - }$ electrolyte, and apart from this, other counter electrode materials for iodine‐free redox electrolytes are discussed. Different counter electrode materials are highlighted in different categories such as carbon materials, conducting polymers, oxide and sulfide materials, transition‐metal nitrides and carbides, and composite materials. The stability of counter electrodes in DSSCs is also presented.
Establishing the Coordination Chemistry of Antimony(V) Cations: Systematic Assessment of Ph4Sb(OTf) and Ph3Sb(OTf)2 as Lewis Acceptors
Authors: Robertson Alasdair P. M. , Chitnis Saurabh S. , Jenkins Hilary A. , McDonald Robert , Ferguson Michael J. , Burford Neil 
Published: April 2015

AbstractThe coordination chemistry of the stiboranes Ph4Sb(OTf) (1 a, OTf = OSO2CF3) and Ph3Sb(OTf)2 (3) with Lewis bases has been investigated. The significant steric encumbrance of the Sb center in 1 a precludes interaction with most ligands, but the relatively low steric demands of 4‐methylpyridine‐N‐oxide (OPyrMe) and OPMe3 enabled the characterization of [Ph4Sb(OPyrMe)][OTf] (2 a) and [Ph4Sb(OPMe3)][OTf] (2 b), rare examples of structurally characterized complexes of stibonium acceptors. In contrast, 3 was found to engage a variety of Lewis bases, forming stable isolable complexes of the form [Ph3Sb(donor)2][OTf]2 [donor=OPMe3 (6 a), OPCy3 (6 b, Cy=cyclohexyl), OPPh3 (6 c), OPyrMe (6 d)], [Ph3Sb(dmap)2(OTf)][OTf] (6 e, dmap=4‐(dimethylamino)pyridine) and [Ph3Sb(donor)(OTf)][OTf] [donor=1,10‐phenanthroline (7 a) or 2,2′‐bipy (7 b, bipy=bipyridine)]. These compounds exhibit significant structural diversity in the solid‐state, and undergo ligand exchange reactions in line with their assignment as coordination complexes. Compound 3 did not form stable complexes with phosphine donors, with reactions instead leading to redox processes yielding SbPh3 and products of phosphine oxidation.