bluuebunny/crossref_metadata_2025_split huggingface dataset:
Antagonism of Cell Adhesion by an α-Catenin Mutant, and of the Wnt-signaling Pathway by α-Catenin in Xenopus Embryos
Authors: Sehgal Ravinder N.M. , Gumbiner Barry M. , Reichardt Louis F. 
Published: July 2002

In Xenopus laevis development, β-catenin plays an important role in the Wnt-signaling pathway by establishing the Nieuwkoop center, which in turn leads to specification of the dorsoventral axis. Cadherins are essential for embryonic morphogenesis since they mediate calcium-dependent cell–cell adhesion and can modulate β-catenin signaling. α-catenin links β-catenin to the actin-based cytoskeleton. To study the role of endogenous α-catenin in early development, we have made deletion mutants of αN-catenin. The binding domain of β-catenin has been mapped to the NH2-terminal 210 amino acids of αN-catenin. Overexpression of mutants lacking the COOH-terminal 230 amino acids causes severe developmental defects that reflect impaired calcium-dependent blastomere adhesion. Lack of normal adhesive interactions results in a loss of the blastocoel in early embryos and ripping of the ectodermal layer during gastrulation. The phenotypes of the dominant-negative mutants can be rescued by coexpressing full-length αN-catenin or a mutant of β-catenin that lacks the internal armadillo repeats.
We next show that coexpression of αN-catenin antagonizes the dorsalizing effects of β-catenin and Xwnt-8. This can be seen phenotypically, or by studying the effects of expression on the downstream homeobox gene Siamois. Thus, α-catenin is essential for proper morphogenesis of the embryo and may act as a regulator of the intracellular β-catenin signaling pathway in vivo.
Operator versions of the Kantorovich inequality
Authors: Spain P. 
Published: July 2002

The Operator Kantorovich Inequality
\[

(

R
2

−

r
2

)

u
∗

(

a
∗

a
)

u
≤

R
2

(

u
∗

a
∗

u
)
(

u
∗

a
u
)

(R^2 - r^2) \, u^* (a^* a) \, u \le R^2 \, (u^* a^* u) (u^* a u)

\]
holds for a wide class of operators

a
a

on a Hilbert space

H

\mathcal {H}

and all operators

u
:

K

→

H

u: \mathcal {K}\to \mathcal {H}

for which

[
a
]

u

[a] \, u

is a partial isometry,

[
a
]

[a]

being the range projection of

a
.

a.
The Hom-spaces between projective functors
Authors: Backelin Erik 
Published: July 2002

The category of projective functors on a block of the category

O

(

g

)

\mathcal O(\mathfrak g)

of Bernstein, Gelfand and Gelfand, over a complex semisimple Lie algebra

g

\mathfrak g

, embeds to a corresponding block of the category

O

(

g

×

g

)

\mathcal O(\mathfrak g \times \mathfrak g)

. In this paper we give a nice description of the object

V
V

in

O

(

g

×

g

)

\mathcal O(\mathfrak g \times \mathfrak g)

corresponding to the identity functor; we show that

V
V

is isomorphic to the module of invariants, under the diagonal action of the center

Z

\mathcal Z

of the universal enveloping algebra of

g

\mathfrak g

, in the so-called anti-dominant projective. As an application we use Soergel’s theory about modules over the coinvariant algebra

C
C

, of the Weyl group, to describe the space of homomorphisms of two projective functors

T
T

and

T
′

T’

. We show that there exists a natural

C
C

-bimodule structure on

Hom

{
Functors
}

⁡
(
T
,

T
′

)

\operatorname {Hom}_{\{\operatorname {Functors}\}}(T, T’)

such that this space becomes free as a left (and right)

C
C

-module and that evaluation induces a canonical isomorphism

k

⊗
C

Hom

{
Functors
}

⁡
(
T
,

T
′

)
≅

Hom

O

(

g

)

⁡
(
T
(

M
e

)
,

T
′

(

M
e

)
)

k \otimes _C \operatorname {Hom}_{\{\operatorname {Functors}\}} (T, T’) \cong \operatorname {Hom}_{\mathcal O(\mathfrak g)}(T(M_e), T’(M_e))

, where

M
e

M_e

denotes the dominant Verma module in the block and

k
k

is the complex numbers.
PHYSEAN: PHYsical SEquence ANalysis for the identification of
protein domains on the basis of physical and chemical properties of
amino acids
Authors: Ladunga Istvan 
Published: July 2002

Abstract
Motivation: PHYSEAN predicts protein classes with highly variable sequences on the basis of their physical, chemical and biological characteristics such as diverse hydrophobicity, structural propensity and steric properties. These characteristics, calculated from multiple positions in a sequence, may be conserved even between sequences that fail to produce alignments at any acceptable level of statistical significance. PHYSEAN complements methods that require sequence alignments (BLAST, FASTA, dynamic programming) by adding less residue- and position-specific physicochemical information on the protein or the domain.
Results: We predict proteins or their domains like signal peptides using physical, chemical, geometric, and biological properties of the 20 amino acids. This comprehensive set of properties may cover the diagnostic functional and structural aspects of a domain or a protein class. We automatically select and weight a subset of properties so as to discriminate between, e.g., signal peptides and amino-termini of cytosolic proteins with the lowest number of incorrect predictions. This optimal selection of properties and their weights significantly decreases the number of incorrect predictions as compared to any single property or any combination of unweighted properties. Weights have been optimized by high-performance linear programming models that systematically find the optimal solution from among an astronomic number of property/weight combinations. PHYSEAN’s performance is demonstrated by highly accurate predictions of signal peptides (the vehicles for protein transport across membranes) and their cleavage sites. The results indicate reliable predictions are possible even in the lack of sequence conservation using an automated physical and chemical analysis of proteins.
Availability: The source code for the prediction program will be available for collaborators.
Contact: Steve_Ladunga@sbphrd.com
Subunit composition of a bicomponent toxin: Staphylococcal leukocidin forms an octameric transmembrane pore
Authors: Miles George , Movileanu Liviu , Bayley Hagan 
Published: July 2002

AbstractStaphylococcal leukocidin pores are formed by the obligatory interaction of two distinct polypeptides, one of class F and one of class S, making them unique in the family of β‐barrel pore‐forming toxins (β‐PFTs). By contrast, other β‐PFTs form homo‐oligomeric pores; for example, the staphylococcal α‐hemolysin (αHL) pore is a homoheptamer. Here, we deduce the subunit composition of a leukocidin pore by two independent methods: gel shift electrophoresis and site‐specific chemical modification during single‐channel recording. Four LukF and four LukS subunits coassemble to form an octamer. This result in part explains properties of the leukocidin pore, such as its high conductance compared to the αHL pore. It is also pertinent to the mechanism of assembly of β‐PFT pores and suggests new possibilities for engineering these proteins.
Study on influence of air cleaner on room dispersion field and its optimal placement using adjoint concentration
Authors: Kikumoto Hideki , Ooka Ryozo 
Published: November 2022

AbstractBased on the assumption of a nonuniform pollutant concentration distribution and stochastic determination of pollutant sources and receptors in indoor space, this study shows how to formulate the expected pollutant concentration observed by the receptors in the presence of an air cleaner, using adjoint concentration and parameters related to probability of pollutants passing through the cleaner. Using this formulation, the structure of the concentration reduction effect of the cleaner and its optimal placement are discussed. The studies with the formulation are also conducted under the assumption of instantaneous uniform diffusion and for a problem in one‐dimensional space.
Metabolic Recycling Enhances Proliferation in MYC‐Transformed Lymphoma B Cells
Authors: Zhang Cissy , Hoang Giang , Attarwala Nabeel , Cooper Arthur J. L. , Asaka Ryoichi , Le Anne 
Published: November 2022

AbstractRelapses negatively impact cancer patient survival due to the tumorigenesis ability of surviving cancer cells post‐therapy. Efforts are needed to better understand and combat this problem. This study hypothesized that dead cell debris post‐radiation therapy creates an advantageous microenvironment rich in metabolic materials promoting the growth of remaining live cancer cells. In this study, live cancer cells are co‐cultured with dead cancer cells eradicated by UV radiation to mimic a post‐therapy environment. Isotopic labeling metabolomics is used to investigate the metabolic behavior of cancer cells grown in a post‐radiation‐therapy environment. It is found that post‐UV‐eradicated dead cancer cells serve as nutritional sources of “off‐the‐shelf” and precursor metabolites for surviving cancer cells. The surviving cancer cells then take up these metabolites, integrate and upregulate multiple vital metabolic processes, thereby significantly increasing growth in vitro and probably in vivo beyond their intrinsic fast‐growing characteristics. Importantly, this active metabolite uptake behavior is only observed in oncogenic but not in non‐oncogenic cells, presenting opportunities for therapeutic approaches to interrupt the active uptake process of oncogenic cells without affecting normal cells. The process by which living cancer cells re‐use vital metabolites released by dead cancer cells post‐therapy is coined in this study as “metabolic recycling” of oncogenic cells.
Direct Visualization of Magnetic Correlations in Frustrated Spinel ZnFe2O4
Authors: Sandemann Jonas Ruby , Grønbech Thomas Bjørn Egede , Støckler Kristoffer Andreas Holm , Ye Feng , Chakoumakos Bryan C. , Iversen Bo Brummerstedt 
Published: November 2022

AbstractMagnetic materials with the spinel structure (A2+B3+2O4) form the core of numerous magnetic devices, and ZnFe2O4constitutes a peculiar example where the nature of the magnetism is still unresolved. Susceptibility measurements revealed a cusp aroundTc = 13 K resembling an antiferromagnetic transition, despite the positive Curie–Weiss temperature determined to be ΘCW = 102.8(1) K. Bifurcation of field‐cooled and zero‐field‐cooled data belowTcin conjunction with a frequency dependence of the peak position and a non‐zero imaginary component belowTcshows it is in fact associated with a spin‐glass transition. Highly structured magnetic diffuse neutron scattering from single crystals develops between 50 K and 25 K revealing the presence of magnetic disorder which is correlated in nature. Here, the 3D‐mΔPDF method is used to visualize the local magnetic ordering preferences, and ferromagnetic nearest‐neighbor and antiferromagnetic third nearest‐neighbor correlations are shown to be dominant. Their temperature dependence is extraordinary with some flipping in sign and a strongly varying correlation length. The correlations can be explained by orbital interaction mechanisms for the magnetic pathways and a preferred spin cluster. This study demonstrates the power of the 3D‐mΔPDF method in visualizing complex quantum phenomena thereby providing a way to obtain an atomic‐scale understanding of magnetic frustration.
Switchable Polyacrylonitrile‐Copolymer for Melt‐Processing and Thermal Carbonization—3D Printing of Carbon Supercapacitor Electrodes with High Capacitance
Authors: Usselmann Michael , Bansmann Joachim , Kuehne Alexander J. C. 
Published: November 2022

AbstractPolyacrylonitrile (PAN) represents the most widely used precursor for carbon fibers and carbon materials. Carbon materials stand out with their high mechanical performance, but they also show excellent electrical conductivity and high surface area. These properties render carbon materials suitable as electrode material for fuel cells, batteries, and supercapacitors. However, PAN has to be processed from solution before being thermally converted to carbon, limiting its final format to fibers, films, and non‐wovens. Here, a PAN‐copolymer with an intrinsic plasticizer is presented to reduce the melting temperature and avoid undesired entering of the thermal carbonization regime. This plasticizer enables melt extrusion‐based additive manufacturing (EAM). The plasticizer in the PAN‐copolymer can be switched to increase the melting temperature after processing, allowing the 3D‐melt‐printed workpiece to be thermally carbonized after EAM. Melt‐processing of the PAN copolymer extends the freedom‐in‐design of carbon materials to mold‐free rapid prototyping, in the absence of solvents, which enables more economic and sustainable manufacturing processes. As an example for the capability of this material system, open meshed carbon electrodes are printed for supercapacitors that are metal‐ and binder‐free with an optimized thickness of 1.5 mm and a capacitance of up to 387 mF cm−2.
Observation of Plasmoelectric Effect in Plasmonic Zirconium Nitride
Authors: Ishii Satoshi , Yu Min‐Wen , Chen Kuo‐Ping , Nagao Tadaaki 
Published: November 2022

AbstractA plasmonic nanostructure forming a metal‐semiconductor interface generates electric potential by optical illumination. Grounded plasmonic nanostructures can also generate electric potentials based on the recently demonstrated plasmoelectric effect that allows all metallic photoelectric devices to be fabricated and is capable of generating negative and positive potentials at off‐resonance by merely tuning the illumination wavelength. However, to date, the plasmoelectric effect has been observed only with gold and silver. In this study, the generation of plasmoelectric effect by zirconium nitride (ZrN) is experimentally demonstrated, which is a nonmetallic plasmonic material. The Kelvin probe force microscope measurements demonstrate that ZrN nanodisk arrays fabricated through e‐beam lithography and dry etching exhibit characteristic potential sign changes of the plasmoelectric potential. The features of the wavelength‐dependent potential shifts in the experiments agree with the numerical calculations. It is anticipated that the plasmoelectric effect can be observed in other non‐metallic plasmonic materials and these studies may lead to robust photoelectric devices working at off‐resonances.
Structurally Tailored Hierarchical Cu Current Collector with Selective Inward Growth of Lithium for High‐Performance Lithium Metal Batteries
Authors: Yang Inyeong , Jeong Ji‐hun , Seok Jae Young , Kim Sanha 
Published: November 2022

AbstractLi‐metal is gaining attention as a next generation anode active material, of which the primary attribute is its energy density. However, Li dendrite formation is the primary challenge. Herein, a design strategy with increased structural dimensions and hierarchy for Li‐metal anode is investigated to stabilize the dendrite formation for extending the cycle life with high reversibility. For this, diverse structural current collectors (CCs) are fabricated by manipulating structural design in different length scales and characterized as a Li‐metal anode. The hierarchy (i.e., nanostructures inside the microcavities) can not only reduce the current density on entire anode surface but also concentrate the local electrical field onto inner surfaces of the microstructures, inducing preferential Li nucleation inside microcavities and promoting confined growth of Li. It is confirmed that introduction of structural hierarchy can enhance the cycle life by 364% and the preservation of coulombic efficiency > 90% by 266%. The design strategy is extended by exploring a practical one‐step fabrication of the hierarchical CC with even greater performance via the inward growth mechanism. This work elucidates the mechanism of inward Li growth using tailored surface geometries for Li dendrite suppression, which can be a guideline for designing structured anode CCs for Li‐metal batteries.
Fish seed and feed value chains analysis and their critical factors for aquaculture development in Tanzania
Authors: Shoko Amon Paul , Limbu Samwel Mchele , Ulotu Eusebia Ernest , Shayo Salome Daniel , Silas Mathew Ogalo , Chimatiro Sloans K. , Madalla Nazael Amos , Tamatamah Rashid Adam 
Published: November 2022

AbstractSeeds and feeds are among the most important inputs required for sustainable aquaculture industry development in any country worldwide. However, the value chain analysis of seeds and feeds in most developing countries including Tanzania has not been mapped, and the key actors are not identified and characterized. To address this knowledge gap, we mapped the fish seed and feed value chains in Morogoro, Dar es Salaam, Coast and Lindi regions in Tanzania, evaluated their performances, analyzed their contributions to aquaculture growth and finally assessed the critical factors impending aquaculture development before proposing appropriate strategies for upgrading. We found that the fish seed value chain comprised broodstock suppliers, seed producers, seed marketers, traders and fish farmers. Tilapia (Oreochromis sp.) and African sharptooth catfish (Clarias gariepinus) seeds produced were primarily sold to farmers at an advanced fry stage (1 to 5 g) at a price ranging from USD 0.09 to 0.13 and USD 0.22 to 0.27, respectively. The feed value chain consisted of suppliers, producers, importers, traders and fish farmers. The feeds produced were powdered, compressed and extruded pellets and granules sold at an average price of USD 2.50/kg. The seed and feed value chains in the four regions drive the aquaculture development and employ 137 and 109 people, respectively. The fish farming was mainly affected by insufficient seeds and feeds; inadequate extension services, inadequate technical skills in seed and feed production; limited farming equipment; insufficient capital and limited access to market. We propose increasing seed and feed production through collaborative research between researchers and the private sector, enhancing delivery of extension services to all fish farmers, providing fiscal incentives to hatchery and feed investors, organizing hatchery owners into associations, and undertaking marketing awareness campaign for aquaculture growth in the country for food, income and employment generation.
Continuous flow photocatalytic reactor using TiO2‐coated foams, modeling and experimental operating mode
Authors: Goetz Vincent , Dezani Chloé , Ribeiro Enrique , Caliot Cyril , Plantard Gael 
Published: November 2022

AbstractThis article aims to build a modeling and simulating tool of the operation of a continuous flow heterogeneous photocatalysis reactor. Continuous flow is well‐known in reactor engineering for allowing advanced control of reactor and scaling‐up with great confidence, but little research has addressed it's potential for this kind of application. In developing this model, particular attention was paid to the coupling which occurs at local scale between the radiative transfer and the reaction kinetics of advanced oxidation of a target organic micro‐pollutant. The solution of the radiative transfer equation by Monte Carlo method was applied to a photocatalyst supported on a macroporous ceramic foam forming an efficient 3D support. After identification of the kinetic law of degradation, the dynamic simulation model was validated through comparison with a series of experiments performed for different but constant irradiations and for variable irradiations approaching, in term of intensity and dynamics, natural solar radiation.
Modulating acid site spatial location of Zn/ZSM‐5 catalyst to boost the stable aromatization of hexane
Authors: Yan Hao , Ren Delun , Li Zhiqiang , Chen Junshu , Zhang Xinyang , Wang Yanhao , Duan Gongzheng , Feng Xiang , Zhou Xin , Liu Yibin , Chen Xiaobo , Yang Chaohe 
Published: November 2022

AbstractEngineering acid site spatial location of zeolite catalyst harbors tremendous potential to boost catalytic performance but still remains a grand challenge for aromatization reaction. Herein, we successfully manipulate acid site spatial location inside the ZSM‐5 channels to promote the hexane aromatization via the simple SiO2 coating treatment. Multi‐techniques demonstrated that the medium strong L acid in the channel originated from the Si(Al)OZn structure is mainly retained in the Zn/ZSM‐5‐Si catalyst by covering the acid sites outside the channel. Surprisingly, there is a good linear relationship between BTEX yield and this medium strong L acid content. Based on the reaction kinetics, in situ FT‐IR and theoretical calculations, it is found that the L acid with confinement effect served as the main active site could prominently enhance the cyclization of propene intermediate and the dehydrogenation of cycloalkane due to the strong affinity between the C/H and ZnOx, and control the desorption of BTEX (mainly benzene, toluene, ethylbenzene, and p‐xylene) by weakening the binding of hydrogen proton to π electrons. Compared with the ordinary Zn/ZSM‐5 catalyst, the yield of BTEX is increased by nearly 10%, and the Zn/ZSM‐5‐Si catalyst exhibits excellent anti coking deactivation ability. This strategy together with mechanistic results may pave the rational design of efficient Zn/ZSM‐5 catalysts for aromatization reaction.
Identification of causal effects of neuroanatomy on cognitive decline requires modeling unobserved confounders
Authors: Pölsterl Sebastian , Wachinger Christian ,   the Alzheimer's Disease Neuroimaging Initiative,   the Japanese Alzheimer's Disease Neuroimaging Initiative
Published: November 2022

AbstractIntroductionCarrying out a randomized controlled trial to estimate the causal effects of regional brain atrophy due to Alzheimer's disease (AD) is impossible. Instead, we must estimate causal effects from observational data. However, this generally requires knowing and having recorded all confounders, which is often unrealistic.MethodsWe provide an approach that leverages the dependencies among multiple neuroanatomical measures to estimate causal effects from observational neuroimaging data without the need to know and record all confounders.ResultsOur analyses of subjects from the Alzheimer's Disease Neuroimaging Initiative demonstrate that using our approach results in biologically meaningful conclusions, whereas ignoring unobserved confounding yields results that conflict with established knowledge on cognitive decline due to AD.DiscussionThe findings provide evidence that the impact of unobserved confounding can be substantial. To ensure trustworthy scientific insights, future AD research can account for unobserved confounding via the proposed approach.