bluuebunny/crossref_metadata_2025 huggingface dataset:
Interactive effects of iron and temperature on the growth of Fragilariopsis cylindrus
Authors: Jabre Loay , Bertrand Erin M.
Published: May 2020

Iron and temperature are important drivers controlling phytoplankton growth in the Southern Ocean (SO). Most studies examining phytoplankton responses to these variables consider them independently, testing responses to changing temperature under constant iron and vice versa. Consequently, we lack a phenomenological and mechanistic understanding of how concurrent changes in these variables influence primary productivity. Here, we used a matrix of three temperatures and eight iron levels to examine changes in growth rate, photophysiology, and size in Fragilariopsis cylindrus. Temperature and iron interactively influenced growth; warming decreased iron demand, allowing cells to maintain half‐maximal growth rate at lower iron concentrations. We also observed possible mechanisms underpinning this phenomenon: warming increased light‐harvesting cross section and reduced cell size, thereby increasing light energy availability and iron uptake efficiency. These results suggest that interactive iron‐warming effects could lead to larger increases in SO phytoplankton growth than those currently predicted by marine ecosystem models.
Endogenous research and development spillovers and asymmetric firms
Authors: Poyago‐Theotoky Joanna , Talerngsri Teerasuwannajak Khemarat
Published: May 2020

We examine an asymmetric research and development (R&D) duopoly, where firms differ in their research and development productivity, one firm being technologically advanced. We find that both firms can benefit and increase their profitability by entering into a voluntary information sharing agreement despite their asymmetry and highlight the conditions needed for such an agreement to take place.
CSF NFL in a Longitudinally Assessed PD Cohort: Age Effects and Cognitive Trajectories
Authors: Lerche Stefanie , Wurster Isabel , Röben Benjamin , Zimmermann Milan , Machetanz Gerrit , Wiethoff Sarah , Dehnert Monique , Rietschel Lea , Riebenbauer Benjamin , Deuschle Christian , Stransky Elke , Lieplt‐Scarfone Inga , Gasser Thomas , Brockmann Kathrin
Published: May 2020

Background

Neurofilament light protein is an unspecific biofluid marker that reflects the extent of neuronal/axonal damage and thereby offers the chance monitor disease severity and progression. The objective of this study was to investigate cerebrospinal fluid (CSF) levels of neurofilament light protein in Parkinson’s disease (PD) patients with clinical trajectories of motor and cognitive function longitudinally.

Methods

CSF neurofilament light protein levels were assessed in 371 PDsporadic, 126 genetic PD patients (91 PDGBA, 8 PDLRRK2, 21 PDPRKN/PINK1/DJ1_heterozygous, 6 PDPRKN/PINK1/DJ1_homozygous), and 71 healthy controls. Participants were followed up longitudinally for up to 8 years.

Results

At baseline, mean CSF neurofilament light protein levels were highest in PD patients with cognitive impairment (Montreal Cognitive Assessment score ≤ 25; 1207 pg/mL) but also higher in PD patients with normal cognitive function (757 pg/mL) compared with healthy controls (593 pg/mL; P ≤ 0.001). In healthy controls and in PD patients older age was associated with higher CSF levels of neurofilament light protein (P ≤ 0.001). In PD patients, male gender, older age at onset, longer disease duration, higher Hoehn and Yahr stages, higher UPDRS‐III scores, and lower Montreal Cognitive Assessment scores were associated with higher CSF levels of neurofilament light protein (P < 0.01). In patients who developed cognitive impairment during study, CSF neurofilament light protein levels prior to conversion to cognitive impairment were not significantly different compared with CSF neurofilament light protein levels of patients who remained cognitively normal.

Conclusions

Increased CSF levels of neurofilament light protein are associated with cognitive decline and motor impairment in PD. However, this increase seems not a very early event and does not mark the conversion to cognitive impairment beforehand. Therefore, the predictive value needs to be discussed critically. © 2020 International Parkinson and Movement Disorder Society
Advances in drug development for targeted therapies for glioblastoma
Authors: Yan Ge , Wang Yunfu , Chen Jincao , Zheng Wenzhong , Liu Changzhen , Chen Shi , Wang Lianrong , Luo Jie , Li Zhiqiang
Published: May 2020

Glioblastoma is the most aggressive primary brain tumor in adults. The prognosis of patients with primary glioblastoma treated with the current standard of care, tumor resection followed by radiation therapy and auxiliary temozolomide, remains poor. Integrative genomic analyses have identified essential core signaling pathways and frequent genetic aberrations, which provide potential drug targets for glioblastoma treatment. Drugs against these therapeutic targets have been developed rapidly in recent years. Although some have shown promising effects on models in preclinical studies, many have shown only modest efficacy in clinical trials. New therapeutic strategies and potent drugs are urgently needed to improve the prognosis of patients with glioblastoma. The goal of this review is to summarize the current advances in drug development for targeted glioblastoma therapies and to reveal the major challenges encountered in clinical trials or treatment. This study will provide new perspectives for future studies of targeted therapeutic drug development and provide insights into the clinical treatment of glioblastoma.
Effect of base fluids on thermo‐physical properties of SiO2 nanofluids and development of new correlations
Authors: Kumar Vandrangi Seshu , Hassan Suhaimi , Sharma Korada Viswanath , Akilu Suleiman , Emani Sampath , Nabipour Narjes
Published: May 2020

The enhanced thermal properties are the prominent objective behind the usage of nanofluids. Hence, it is necessary to study the base/nanofluid physical properties at various conditions. This article projects the experimental results of thermal conductivity and viscosity of two different nanofluids. The ratio was considered as 60:40 and 40:40 by volume in water and ethylene glycol, respectively. The preparation of nanofluids was started by scattering SiO2 nanoparticles in EG and “water” (W) blended in “60:40” (60EGW) and “40:60” (40EGW) ratio by volume. The regression analysis was conducted with available data, and correlations were formulated for thermal properties. The nanofluids were used in evaluating “viscosity” and “thermal conductivity” experimentally. From the results, the SiO2 particles have achieved an enhancement of 34% and 32% in thermal conductivity with the two base fluids. Similarly, an enhancement of 102% and 62% was reported in viscosity. Hence, it can be observed that SiO2 nanofluids in 40EGW nanofluid are better heat transfer fluids when compared with SiO2 in 60EGW nanofluid.
Dynamics of antibody levels: Asymptotic properties
Authors: Pichór Katarzyna , Rudnicki Ryszard
Published: May 2020

We study properties of a piecewise deterministic Markov process modeling the changes in concentration of specific antibodies. The evolution of densities of the process is described by a stochastic semigroup. The long‐time behavior of this semigroup is studied. In particular, we prove theorems on its asymptotic stability.
Broadband circularly polarized edge feed rectangular dielectric resonator antenna using effective glueless technique
Authors: Meher Priya Ranjan , Behera Bikash Ranjan , Mishra Sanjeev Kumar
Published: May 2020

In this article, a broadband circularly polarized rectangular dielectric resonator antenna (CP‐RDRA) is explored and reported. The proposed antenna comprises of rectangular dielectric resonator (DR) made up of aluminum oxide placed on a Rogers RT‐5880 substrate and fed by a 50‐Ω microstrip line with a partial ground plane. Microstrip line feed is placed at the right edge of rectangular DR to excite orthogonal fields, which achieves circular polarization (CP). The proposed antenna is fabricated and characterized. The measured −10 dB impedance bandwidth and 3 dB axial bandwidth are obtained as 5.44 GHz (5.79‐11.23 GHz) and 2.93 GHz (6.08‐9.01 GHz), respectively. The peak realized gain and antenna efficiency are obtained to be 4.62 dBi and 94%, respectively, in the desired frequency band. In addition, the proposed CP‐RDRA is also realized using a new technique of glueless concept to achieve mechanical stability that also enhances the axial bandwidth without affecting the radiation characteristics. It is observed from the results that the proposed antenna can be a potential candidate for C‐band and X‐band in satellite communication systems.
Design of planar inverted‐F antenna pair with reflectors for near‐field power transfer
Authors: Lin Ding‐Bing , Wu Ifong , Huang Pei‐Chuan
Published: May 2020

In this article, a planar inverted‐F antenna (PIFA) pair with reflectors for near‐field power transfer at a frequency of 2.45 GHz is proposed. In order to enhance efficiency of power transmission and reduce electromagnetic wave leaked to free space due to the power transmission, the reflectors are installed around the transmitting and receiving antenna pair except on the open side. The transmitting antenna is designed with high impedance characteristics to prevent the radiated electromagnetic wave to free space when the antenna is waiting for the power transmission. The receiving antenna is designed for Wi‐Fi and also functions as an antenna for energy harvesting at a frequency of 2.4 GHz when the antenna operates solely. Furthermore, the L‐shaped slot is added on the FR‐4 substrate of the receiving antenna as a harmonic rejection filter (HRF) used to suppress reradiation of the higher order harmonics and improve the conversion efficiency. The conversion efficiency of the proposed transmitting and receiving antenna pair is 79.4% when the input RF power is 23 dBm.
MRI‐compatibility study of a PET‐insert based on a low‐profile detection front‐end with submillimeter spatial resolution
Authors: Moghadam Narjes , Bouchard Jonathan , Espagnet Romain , Fontaine Réjean , Lecomte Roger
Published: May 2020

Purpose

The LabPET II detection module is a potential candidate to create an magnetic resonance imaging (MRI) compatible positron emission tomography (PET)‐insert with submillimeter spatial resolution for small animal applications. However, the feasibility of such an insert is hampered by the large radial size of the LabPET II front‐end electronics and by components containing ferromagnetic materials. In this paper, a new low‐profile front‐end design based on the LabPET II architecture, called “low‐profile detection module,” is investigated.

Materials and methods

The performance of the low‐profile detection module in the presence of MRI‐like RF signals and gradient coil pulses was independently examined. The baseline of the analog signal, its RMS noise level, and the energy resolution, determined by a dual time‐over‐threshold (dTOT) method for each pixel of the new low‐profile detection module, was measured in the presence of RF signals at different frequencies equivalent to the Larmor frequency of 3, 7, and 9.4 T MRI. The same parameters were investigated in the presence of a gradient coil switching at frequencies from 10 to 100 kHz. The performance of the low‐profile detection module inside a 7 T MRI and its effects on an MR image have also been studied using gradient echo sequences. The same measurements were repeated for the shielded low‐profile detection module, inside and outside the MRI.

Results

Our results show that pulses in both the kilohertz and megahertz ranges cause up to 50% increase in the noise level of the baseline (DC analog signal at the output of the shaper filter) and up to 17% degradation in TOT energy resolution. By inserting a conducting composite layer as shielding around the low‐profile detection module, these degrading effects were avoided. The performance measurement of the low‐profile PET detection module inside a 7 T small animal MRI scanner confirmed that the shielded low‐profile detection module behavior was similar inside and outside the MRI bore. In addition, gradient echo images of a water‐filled phantom without and with the shielded and unshielded low‐profile detection modules were acquired. The results demonstrated no evidence of artifacts in the MR image, either due to eddy currents or ferromagnetic materials with the shielded modules.

Conclusion

A low‐profile detection module based on the LabPET II technology was shown to be a viable candidate as a PET‐insert for simultaneous PET/MRI applications considering its thin radial size and its EMI immunity due to placing it between two electronic boards. In comparison to the standard LabPET II detection module, it provides better performance in the presence of electromagnetic interferences, but a shielding layer is still required. When properly shielded, the proposed low‐profile detection module can be operated inside an MRI without degrading the PET count rate or the MRI performance.
Personal values in adolescence and sense of coherence in adulthood: A cross‐sectional study based on a retrospective recall
Authors: Yasuma Naonori , Watanabe Kazuhiro , Nishi Daisuke , Kawakami Norito
Published: May 2020

Aims

The purpose of this study is to retrospectively examine the association between personal values in adolescence and sense of coherence (SOC) in adulthood.

Methods

J‐SHINE data from wave 1 (2010) and wave 3 (2017) were used in this study. We retrospectively measured personal values at age 15 in 2017 in two ways: (a) value priorities developed from Schwartz's theory of basic values; and (b) the commitment to values measured by Personal Values Questionnaire II (PVQ‐II). Multiple regression analysis was used to estimate the association.

Results

Having a value priority of belief, pursuing one's interest, enduring active challenges, cherishing family and friends, and having a commitment to values in adolescence were significantly and positively associated, while avoiding causing trouble was significantly and negatively associated with SOC in adulthood.

Conclusions

Personal values in adolescence may be associated with SOC in adulthood. Research of personal values in adolescence could contribute to the understanding the development of SOC.
Severe Obesity as an Independent Risk Factor for COVID‐19 Mortality in Hospitalized Patients Younger than 50
Authors: Klang Eyal , Kassim Gassan , Soffer Shelly , Freeman Robert , Levin Matthew A. , Reich David L.
Published: May 2020

Objective

Coronavirus disease 2019 (COVID‐19) continues to spread, and younger patients are also being critically affected. This study analyzed obesity as an independent risk factor for mortality in hospitalized patients younger than 50.

Methods

This study retrospectively analyzed data of patients with COVID‐19 who were hospitalized to a large academic hospital system in New York City between March 1, 2020, and May 17, 2020. Data included demographics, comorbidities, BMI, and smoking status. Obesity groups included the following: BMI of 30 to < 40 kg/m2 and BMI ≥ 40 kg/m2. Multivariable logistic regression models identified variables independently associated with mortality in patients younger and older than 50.

Results

Overall, 3,406 patients were included; 572 (17.0%) patients were younger than 50. In the younger age group, 60 (10.5%) patients died. In the older age group, 1,076 (38.0%) patients died. For the younger population, BMI ≥ 40 was independently associated with mortality (adjusted odds ratio 5.1; 95% CI: 2.3‐11.1). For the older population, BMI ≥ 40 was also independently associated with mortality to a lesser extent (adjusted odds ratio 1.6; 95% CI: 1.2‐2.3).

Conclusions

This study demonstrates that hospitalized patients younger than 50 with severe obesity are more likely to die of COVID‐19. This is particularly relevant in the Western world, where obesity rates are high.
Remdesivir: Review of Pharmacology, Pre‐clinical Data, and Emerging Clinical Experience for COVID‐19
Authors: Jorgensen Sarah C.J. , Kebriaei Razieh , Dresser Linda D.
Published: May 2020

The global pandemic of novel coronavirus disease 2019 (COVID‐19) caused by severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) has created an urgent need for effective antivirals. Remdesivir (formerly GS‐5734) is a nucleoside analogue pro‐drug currently being evaluated in COVID‐19 clinical trials. Its unique structural features allow high concentrations of the active triphosphate metabolite to be delivered intracellularly and it evades proofreading to successfully inhibit viral RNA synthesis. In pre‐clinical models, remdesivir has demonstrated potent antiviral activity against diverse human and zoonotic β‐coronaviruses, including SARS‐CoV‐2. In this article, we critically review available data on remdesivir with an emphasis on biochemistry, pharmacology, pharmacokinetics, and in vitro activity against coronaviruses as well as clinical experience and current progress in COVID‐19 clinical trials.
Pediatric pulmonology year in review 2019: Sleep medicine
Authors: Afolabi‐Brown Olufunke , Tapia Ignacio E.
Published: May 2020

Pediatric Pulmonology publishes original research, review articles as well as case reports on a wide variety of pediatric respiratory disorders. In this article, we summarize the past year's publications in sleep medicine and we review selected literature from other journals within this field. Articles highlighted are topics on risk factors of sleep‐disordered breathing, diagnosis, and treatment of obstructive sleep apnea as well as the utility of polysomnography in various complex conditions.
A systematic review of MAKO‐assisted unicompartmental knee arthroplasty
Authors: Lin Jiyan , Yan Shigui , Ye Zhaoming , Zhao Xiang
Published: May 2020

Unicompartmental knee arthroplasty (UKA), which has many potential advantages compared with total knee arthroplasty, was widely used across the world in recent years. The introduction of the robot systems greatly makes up for the defects of the conventional UKA surgery such as higher complication rates and revision rates. MAKO system, a new image‐guided robot system relies on a preoperative computed tomography scan to assist in preoperative mapping and planning, offers an opportunity to improve the outcome of UKA surgeries. In order to have a more comprehensive and in‐depth understanding of MAKO‐assisted UKA, the studies on MAKO‐assisted UKA were summarized. MAKO‐assisted UKA is better than conventional UKA surgery on implant accuracy, soft tissue balance, patient function scores and satisfaction, complications rates, and learning curve in short‐term outcome; however, the mid‐term and long‐term outcomes of MAKO‐assisted UKA need to be further studied.
Projections of the Aldous chain on binary trees: Intertwining and consistency
Authors: Forman Noah , Pal Soumik , Rizzolo Douglas , Winkel Matthias
Published: May 2020

Consider the Aldous Markov chain on the space of rooted binary trees with n labeled leaves in which at each transition a uniform random leaf is deleted and reattached to a uniform random edge. Now, fix 1 ≤ k<n and project the leaf mass onto the subtree spanned by the first k leaves. This yields a binary tree with edge weights that we call a “decorated k‐tree with total mass n.” We introduce label swapping dynamics for the Aldous chain so that, when it runs in stationarity, the decorated k‐trees evolve as Markov chains themselves, and are projectively consistent over k. The construction of projectively consistent chains is a crucial step in the construction of the Aldous diffusion on continuum trees by the present authors, which is the n→∞ continuum analog of the Aldous chain and will be taken up elsewhere.
Optimized serial expansion of human induced pluripotent stem cells using low-density inoculation to generate clinically relevant quantities in vertical-wheel bioreactors
Authors: Borys Breanna S. , So Tania , Colter James , Dang Tiffany , Roberts Erin L. , Revay Tamas , Larijani Leila , Krawetz Roman , Lewis Ian , Argiropoulos Bob , Rancourt Derrick E. , Jung Sunghoon , Hashimura Yas , Lee Brian , Kallos Michael S.
Published: May 2020

Human induced pluripotent stem cells (hiPSCs) have generated a great deal of attention owing to their capacity for self-renewal and differentiation into the three germ layers of the body. Their discovery has facilitated a new era in biomedicine for understanding human development, drug screening, disease modeling, and cell therapy while reducing ethical issues and risks of immune rejection associated with traditional embryonic stem cells. Bioreactor-based processes have been the method of choice for the efficient expansion and differentiation of stem cells in controlled environments. Current protocols for the expansion of hiPSCs use horizontal impeller, paddle, or rocking wave mixing method bioreactors which require large static cell culture starting populations and achieve only moderate cell fold increases. This study focused on optimizing inoculation, agitation, oxygen, and nutrient availability for the culture of hiPSCs as aggregates in single-use, low-shear, vertical-wheel bioreactors. Under optimized conditions, we achieved an expansion of more than 30-fold in 6 days using a small starting population of cells and minimal media resources throughout. Importantly, we showed that that this optimized bioreactor expansion protocol could be replicated over four serial passages resulting in a cumulative cell expansion of 1.06E6-fold in 28 days. Cells from the final day of the serial passage were of high quality, maintaining a normal karyotype, pluripotent marker staining, and the ability to form teratomas in vivo. These findings demonstrate that a vertical-wheel bioreactor-based bioprocess can provide optimal conditions for efficient, rapid generation of high-quality hiPSCs to meet the demands for clinical manufacturing of therapeutic cell products.

Significance statement This study has developed a new method to grow human induced pluripotent stem cells in large quantities through serial passaging in vertical-wheel bioreactors. Cells were cultured from small starting numbers, in optimized conditions, resulting in economical, reproducible culture techniques for high-quality populations. These advances will have significant economic and practical applications in stem cell therapies.
Stabilization of Poly(Vinyl Chloride) Containing Captopril Tin Complexes against Degradation upon Exposure to Ultraviolet Light
Authors: Majeed Alabbas , Yousif Emad , El‐Hiti Gamal A. , Ahmed Dina S. , Ahmed Ahmed A.
Published: May 2020

Poly(vinyl chloride) (PVC) is commonly used in many industrial applications. Ultraviolet (UV) radiation causes undesirable changes to PVC properties. Therefore, PVC should be protected from radiation to increase its lifetime for outdoor applications. Here, new organotin complexes containing captopril were synthesized for use as low‐concentration additives to enhance PVC photostability. Reacting captopril with the appropriate organotin chloride or dibutyltin oxide gave the corresponding organotin complex in 63% to 89% yield. Captopril tin complexes (0.5 wt%) were added to PVC solution and thin films were produced. The films were irradiated with UV light for 300 hours. The formation of specific functional groups and reduction in weight and molecular weight were monitored during irradiation. In addition, the surface morphology was checked pre before and after irradiation. The results confirmed that undesirable changes in the PVC films occurred to a lower extent in the presence of captopril tin complexes. These additives function as UV absorbers, scavengers for hydrogen chloride, and decomposers for peroxide and coordinate well with the PVC chains. The triphenyltin complex was the best inhibitor of PVC photodegradation, which is likely due to its high aromatic content.
Changes in Crystallization Behaviors of Poly(Vinyl Alcohol) Induced by Water Content
Authors: Xiang Aimin , Lv Chang , Zhou Hongfu
Published: May 2020

Water as the low‐cost, environmentally friendly, easily obtained plasticizer was used widely in the preparation of poly(vinyl alcohol) (PVA) products. However, few researches were done to investigate the effect of water content on the crystallization behaviors of PVA. The water content in various PVA films was controlled by drying in a vacuum oven at different time and was determined by thermogravimetric analysis. The changes in crystallization behaviors of PVA affected by water content were investigated using differential scanning calorimeter, Fourier transform infrared spectra, and X‐ray diffraction. The wafer thickness and nonisothermal crystallization kinetics of various PVA films were also studied. The corresponding results showed that the crystallinity of various PVA films increased and then stabilized as the drying time increased. The distribution of wafer thickness in PVA films became narrow, and their wafer thickness value became small. The decrease of water content in PVA films promoted the crystallization rate, because the movement ability of PVA molecular chains was enhanced by the decrement in hydration hydrogen bonds in various PVA films.
The prospects of quantum computing in computational molecular biology
Authors: Outeiral Carlos , Strahm Martin , Shi Jiye , Morris Garrett M. , Benjamin Simon C. , Deane Charlotte M.
Published: May 2020

Quantum computers can in principle solve certain problems exponentially more quickly than their classical counterparts. We have not yet reached the advent of useful quantum computation, but when we do, it will affect nearly all scientific disciplines. In this review, we examine how current quantum algorithms could revolutionize computational biology and bioinformatics. There are potential benefits across the entire field, from the ability to process vast amounts of information and run machine learning algorithms far more efficiently, to algorithms for quantum simulation that are poised to improve computational calculations in drug discovery, to quantum algorithms for optimization that may advance fields from protein structure prediction to network analysis. However, these exciting prospects are susceptible to “hype,” and it is also important to recognize the caveats and challenges in this new technology. Our aim is to introduce the promise and limitations of emerging quantum computing technologies in the areas of computational molecular biology and bioinformatics.

This article is categorized under:

Structure and Mechanism > Computational Biochemistry and Biophysics

Data Science > Computer Algorithms and Programming

Electronic Structure Theory > Ab Initio Electronic Structure Methods
Phase‐separated bacterial ribonucleoprotein bodies organize mRNA decay
Authors: Muthunayake Nisansala S. , Tomares Dylan T. , Childers W. Seth , Schrader Jared M.
Published: May 2020

In bacteria, mRNA decay is controlled by megadalton scale macromolecular assemblies called, “RNA degradosomes,” composed of nucleases and other RNA decay associated proteins. Recent advances in bacterial cell biology have shown that RNA degradosomes can assemble into phase‐separated structures, termed bacterial ribonucleoprotein bodies (BR‐bodies), with many analogous properties to eukaryotic processing bodies and stress granules. This review will highlight the functional role that BR‐bodies play in the mRNA decay process through its organization into a membraneless organelle in the bacterial cytoplasm. This review will also highlight the phylogenetic distribution of BR‐bodies across bacterial species, which suggests that these phase‐separated structures are broadly distributed across bacteria, and in evolutionarily related mitochondria and chloroplasts.

This article is categorized under:

RNA Turnover and Surveillance > Turnover/Surveillance Mechanisms

RNA Interactions with Proteins and Other Molecules > RNA–Protein Complexes

RNA Export and Localization > RNA Localization

RNA Turnover and Surveillance > Regulation of RNA Stability
Impact of oxygen availability on heterologous geneexpression and polypeptide secretion dynamics in Yarrowia lipolytica‐based protein production platforms
Authors: Gorczyca Maria , Kaźmierczak Jan , Steels Sebastien , Fickers Patrick , Celińska Ewelina
Published: May 2020

Industrially relevant traits of Yarrowia lipolytica, like high growth rate, capacity to grow at high cell density or to synthesize biomolecules with high productivities, strongly rely on sufficient oxygen provision. Although the impact of oxygen availability (OA) on the physiology of Y. lipolytica has been already studied, its influence on recombinant protein (rProt) synthesis and secretion has been largely neglected to date. With the aim to fill this gap, a fluorescent reporter protein (yellow fluorescent protein [YFP]) was used herein as a proxy to follow simultaneously rProt synthesis and secretion in Y. lipolytica under different OAs. This study covers the analysis of the reporter gene expression through reverse transcription quantitative polymerase chain reaction, polypeptide synthesis and its retention‐to‐secretion ratio using flow cytometry and fluorymetry during shake flasks and bioreactor cultivations under different OA. The results gathered demonstrate that OA has a dramatic impact on the kinetics of intracellular and extracellular YFP accumulation. Higher rProt production and secretion were favoured under high OA, and were largely related to OA and not to cell growth. Our observations also suggest the existence of some upper limit of secretory protein accumulation inside the cells above which massive secretion is initiated. Moreover, at low OA, the first bottleneck in rProt synthesis occurs as early as at transcription level, which could results from a lower availability of transcriptional machinery elements. Finally, using flow cytometry and bioreactor cultivations, we highlighted that ovoid cells are generally more efficient in terms of rProt synthesis.
Resummation for the field-theoretical derivation of the negative magnetoresistance
Authors: Fukushima Kenji , Hidaka Yoshimasa
Published: May 2020

Abstract

We show detailed derivation of the electric conductivity of quark matter at finite temperature and density under a magnetic field. We especially focus on the longitudinal electric conductivity along the magnetic direction and establish the field-theoretical description of the negative magnetoresistance as observed in chiral materials. With increasing magnetic field our microscopic calculation leads to changing behavior from approximately quadratic to asymptotically linear dependence of the electric conductivity, while the magnetic dependence is quadratic in the conventional relaxation time approximation. The presented formulation founds a firm basis for the physical interpretation of the negative magnetoresistance in terms of the particle and the hydrodynamic contributions, as well as it offers general methodology applicable for various transport coefficients.
Real-time corrections to the effective potential
Authors: Pimentel Guilherme L. , Stout John
Published: May 2020

Abstract

Non-perturbatively generated effective potentials play an extremely useful and often critical role in string and inflationary model building. These potentials are typically computed by methods that assume the system is in equilibrium. For systems out of equilibrium, like an inflaton rolling down its potential, there are corrections to the semi-classical evolution due to transient phenomena. We provide a new qualitative and quantitative understanding of non-perturbative effects in real time for a wide class of toy quantum mechanical models. We derive an effective Schrödinger equation that does not rely on any notion of equilibrium and captures the low-energy dynamics supposedly described by the effective potential. We find that there are potentially large corrections to this potential that are not captured by standard equilibrium techniques, and quantify when these corrections significantly alter the effective dynamics.
Radiative corrections to the lepton flavor mixing in dense matter
Authors: Zhu Jing-yu
Published: May 2020

Abstract

One-loop radiative corrections will lead to a small difference between the matter potentials developed by ν

μ
and ντ when they travel in a medium. By including such radiative corrections, we derive the exact expressions of the corresponding effective mass- squared differences and the moduli square of the lepton flavor mixing matrix elements

$$ {\left|{\tilde{U}}_{\alpha i}\right|}^2 $$

U
˜

αi

2

(for α = e, μ, τ and i = 1, 2, 3) in matter in the standard three-flavor mixing scheme and focus on their asymptotic behaviors when the matter density is very big (i.e., the matter effect parameter

$$ A\equiv 2\sqrt{2}{G}_{\mathrm{F}}{N}_eE $$

A
≡
2

2

G
F

N
e

E

is very big). Different from the non-trivial fixed value of

$$ {\left|{\tilde{U}}_{\alpha i}\right|}^2 $$

U
˜

αi

2

in the A → ∞ limit in the case without radiative corrections, we get

$$ {\left|{\tilde{U}}_{\alpha i}\right|}^2 $$

U
˜

αi

2

= 0 or 1 under this extreme condition. The radiative corrections can significantly affect the lepton flavor mixing in dense matter, which are numerically and analytically discussed in detail. Furthermore, we also extend the discussion to the (3 + 1) active-sterile neutrino mixing scheme.
Anomaly interplay in U(2) gauge theories
Authors: Davighi Joe , Lohitsiri Nakarin
Published: May 2020

Abstract

We discuss anomaly cancellation in U(2) gauge theories in four dimensions. For a U(2) gauge theory defined with a spin structure, the vanishing of the bordism group

$$ {\Omega}_5^{\mathrm{Spin}} $$

Ω
5
Spin

(BU(2)) implies that there can be no global anomalies, in contrast to the related case of an SU(2) gauge theory. We show explicitly that the familiar SU(2) global anomaly is replaced by a local anomaly when SU(2) is embedded in U(2). There must be an even number of fermions with isospin 2r + 1/2, for r ∈ ℤ≥0, for this local anomaly to cancel. The case of a U(2) theory defined without a choice of spin structure but rather using a spin-U(2) structure, which is possible when all fermions (bosons) have half-integer (integer) isospin and odd (even) U(1) charge, is more subtle. We find that the recently-discovered ‘new SU(2) global anomaly’ is also equivalent, though only at the level of the partition function, to a perturbative anomaly in the U(2) theory, which is this time a combination of a mixed gauge anomaly with a gauge-gravity anomaly. This perturbative anomaly vanishes if there is an even number of fermions with isospin 4r + 3/2, for r ∈ ℤ≥0, recovering the condition for cancelling the new SU(2) anomaly. Alternatively, this perturbative anomaly can be cancelled by a Wess-Zumino term, leaving a low-energy theory with a global anomaly, which can itself be cancelled by coupling to topological degrees of freedom.
Boundary correlators in WZW model on AdS2
Authors: Beccaria Matteo , Jiang Hongliang , Tseytlin Arkady A.
Published: May 2020

Abstract

Boundary correlators of elementary fields in some 2d conformal field theories defined on AdS2 have a particularly simple structure. For example, the correlators of the Liouville scalar happen to be the same as the correlators of the chiral component of the stress tensor on a plane restricted to the real line. Here we show that an analogous relation is true also in the WZW model: boundary correlators of the WZW scalars have the same structure as the correlators of chiral Kac-Moody currents. This is checked at the level of the tree and one-loop Witten diagrams in AdS2. We also compute some tree-level correlators in a generic σ-model defined on AdS2 and show that they simplify only in the WZW case where an extra Kac-Moody symmetry appears. In particular, the terms in 4- point correlators having logarithmic dependence on 1d cross-ratio cancel only at the WZW point. One motivation behind this work is to learn how to compute AdS2 loop corrections in 2d models with derivative interactions related to the study of correlators of operators on Wilson loops in string theory in AdS.
Reflected entropy, symmetries and free fermions
Authors: Bueno Pablo , Casini Horacio
Published: May 2020

Abstract

Exploiting the split property of quantum field theories (QFTs), a notion of von Neumann entropy associated to pairs of spatial subregions has been recently proposed both in the holographic context — where it has been argued to be related to the entanglement wedge cross section — and for general QFTs. We argue that the definition of this “reflected entropy” can be canonically generalized in a way which is particularly suitable for orbifold theories — those obtained by restricting the full algebra of operators to those which are neutral under a global symmetry group. This turns out to be given by the full-theory reflected entropy minus an entropy associated to the expectation value of the “twist” operator implementing the symmetry operation. Then we show that the reflected entropy for Gaussian fermion systems can be simply written in terms of correlation functions and we evaluate it numerically for two intervals in the case of a two-dimensional Dirac field as a function of the conformal cross-ratio. Finally, we explain how the aforementioned twist operators can be constructed and we compute the corresponding expectation value and reflected entropy numerically in the case of the ℤ2 bosonic subalgebra of the Dirac field.
A universal Schwarzian sector in two-dimensional conformal field theories
Authors: Ghosh Animik , Maxfield Henry , Turiaci Gustavo J.
Published: May 2020

Abstract

We show that an extremely generic class of two-dimensional conformal field theories (CFTs) contains a sector described by the Schwarzian theory. This applies to theories with no additional symmetries and large central charge, but does not require a holographic dual. Specifically, we use bootstrap methods to show that in the grand canonical ensemble, at low temperature with a chemical potential sourcing large angular momentum, the density of states and correlation functions are determined by the Schwarzian theory, up to parametrically small corrections. In particular, we compute out-of-time-order correlators in a controlled approximation. For holographic theories, these results have a gravitational interpretation in terms of large, near-extremal rotating BTZ black holes, which have a near horizon throat with nearly AdS2 × S
1 geometry. The Schwarzian describes strongly coupled gravitational dynamics in the throat, which can be reduced to Jackiw-Teitelboim (JT) gravity interacting with a U(1) field associated to transverse rotations, coupled to matter. We match the physics in the throat to observables at the AdS3 boundary, reproducing the CFT results.
Complete Hamiltonian for spinning binary systems at first post-Minkowskian order
Authors: Chung Ming-Zhi , Huang Yu-tin , Kim Jung-Wook , Lee Sangmin
Published: May 2020

Abstract

Building upon recent progress in applying on-shell amplitude techniques to classical observables in general relativity, we propose a closed-form formula for the conservative Hamiltonian of a spinning binary system at the 1st post-Minkowskian (1PM) order. It is applicable for general compact spinning bodies with arbitrary spin multipole moments. The formula is linear in gravitational constant by definition, but exact to all orders in momentum and spin expansions. At each spin order, our formula implies that the spin-dependence and momentum dependence factorize almost completely. We expand our formula in momentum and compare the terms with 1PM parts of the post-Newtonian computations in the literature. Up to canonical transformations, our results agree perfectly with all previous ones. We also compare our formula for black hole to that derived from a spinning test-body near a Kerr black hole via the effective one-body mapping, and find perfect agreement.
A landscape of orientifold vacua
Authors: Carta Federico , Moritz Jakob , Westphal Alexander
Published: May 2020

Abstract

We present a vast landscape of O3/O7 orientifolds that descends from the famous set of complete intersection Calabi-Yau threefolds (CICY). We give distributions of topological data relevant for phenomenology such as the orientifold-odd Hodge numbers, the D3-tadpole, and multiplicities of O3 and O7-planes. Somewhat surprisingly, almost all of these orientifolds have conifold singularities whose deformation branches are projected out by the orientifolding. However, they can be resolved, so most of the orientifolds actually descend from a much larger and possibly new set of CY threefolds that can be reached from the CICYs via conifold transitions. We observe an interesting class of

$$ \mathcal{N} $$

N

= 1 geometric transitions involving colliding O-planes. Finally, as an application, we use our dataset to produce examples of orientifolds that satisfy the topological requirements for the existence of ultra-light throat axions (thraxions) as proposed in [1]. The database can be accessed here: www.desy.de/∼westphal/orientifold webpage/cicy orientifolds.html.
Diacylglycerol kinase and phospholipase D inhibitors alter the cellular lipidome and endosomal sorting towards the Golgi apparatus
Authors: Lingelem Anne Berit Dyve , Kavaliauskiene Simona , Halsne Ruth , Klokk Tove Irene , Surma Michal A. , Klose Christian , Skotland Tore , Sandvig Kirsten
Published: May 2020

The membrane lipids diacylglycerol (DAG) and phosphatidic acid (PA) are important second messengers that can regulate membrane transport by recruiting proteins to the membrane and by altering biophysical membrane properties. DAG and PA are involved in the transport from the Golgi apparatus to endosomes, and we have here investigated whether changes in these lipids might be important for regulation of transport to the Golgi using the protein toxin ricin. Modulation of DAG and PA levels using DAG kinase (DGK) and phospholipase D (PLD) inhibitors gave a strong increase in retrograde ricin transport, but had little impact on ricin recycling or degradation. Inhibitor treatment strongly affected the endosome morphology, increasing endosomal tubulation and size. Furthermore, ricin was present in these tubular structures together with proteins known to regulate retrograde transport. Using siRNA to knock down different isoforms of PLD and DGK, we found that several isoforms of PLD and DGK are involved in regulating ricin transport to the Golgi. Finally, by performing lipidomic analysis we found that the DGK inhibitor gave a weak, but expected, increase in DAG levels, while the PLD inhibitor gave a strong and unexpected increase in DAG levels, showing that it is important to perform lipidomic analysis when using inhibitors of lipid metabolism.
Functions Preserving the Biadditivity
Authors: Łukasik Radosław , Wójcik Paweł
Published: May 2020

In this paper we consider the generalization of the orthogonality equation. Let S be a semigroup, and let H, X be abelian groups. For two given biadditive functions $$A:S^2\rightarrow X$$

A
:

S
2

→
X

, $$B:H^2\rightarrow X$$

B
:

H
2

→
X

and for two unknown mappings $$f,g:S\rightarrow H$$

f
,
g
:
S
→
H

the functional equation $$\begin{aligned} B(f(x),g(y))=A(x,y) \end{aligned}$$

B
(
f
(
x
)
,
g
(
y
)
)
=
A
(
x
,
y
)

will be solved under quite natural assumptions. This extends the well-known characterization of the linear isometry.
Rhythmic episodes of heating and cooling control thermal stratification of two tropical high mountain lakes
Authors: Alcocer Javier , Roberson Jennifer , Oseguera Luis A. , Lewis William M.
Published: May 2020

Continuous temperature monitoring for two adjacent tropical crater lakes in Mexico at 4200 m amsl shows that the lakes have rhythmic episodes of heating and cooling with a duration of ~ 30 days during the warmest months. The episodes were caused by rise and decline of solar irradiance reaching the lake surface. One lake, El Sol, showed over each heating and cooling episode a stable mixed layer (~ 20 days) and a deeper layer with a weak thermal gradient. Temperatures below the mixed layer warmed progressively by eddy diffusion after the mixed layer formed. Stratification was followed by full mixing of the water column. Within the same crater, an adjacent second lake, La Luna, showed the same cycles of heating and cooling; it stratified daily but not over multiple days. The difference between the lakes (discontinuous polymictic, continuous polymictic) is explained by the lower transparency of El Sol, which led to greater heat uptake near the surface than the more transparent La Luna. Lower transparency of El Sol was caused by modest anthropogenic effects on total suspended solids and nutrient loading, i.e., small deviations from the natural condition of El Sol caused it to differ qualitatively from La Luna. Events observed in these lakes would not have been evident from weekly temperature records.
Harnessing the power of novel animal-free test methods for the development of COVID-19 drugs and vaccines
Authors: Busquet Francois , Hartung Thomas , Pallocca Giorgia , Rovida Costanza , Leist Marcel
Published: May 2020

The COVID-19-inducing virus, SARS-CoV2, is likely to remain a threat to human health unless efficient drugs or vaccines become available. Given the extent of the current pandemic (people in over one hundred countries infected) and its disastrous effect on world economy (associated with limitations of human rights), speedy drug discovery is critical. In this situation, past investments into the development of new (animal-free) approach methods (NAM) for drug safety, efficacy, and quality evaluation can be leveraged. For this, we provide an overview of repurposing ideas to shortcut drug development times. Animal-based testing would be too lengthy, and it largely fails, when a pathogen is species-specific or if the desired drug is based on specific features of human biology. Fortunately, industry has already largely shifted to NAM, and some public funding programs have advanced the development of animal-free technologies. For instance, NAM can predict genotoxicity (a major aspect of carcinogenicity) within days, human antibodies targeting virus epitopes can be generated in molecular biology laboratories within weeks, and various human cell-based organoids are available to test virus infectivity and the biological processes controlling them. The European Medicines Agency (EMA) has formed an expert group to pave the way for the use of such approaches for accelerated drug development. This situation illustrates the importance of diversification in drug discovery strategies and clearly shows the shortcomings of an approach that invests 95% of resources into a single technology (animal experimentation) in the face of challenges that require alternative approaches.
Realizing the Braided Temperley–Lieb–Jones C*-Tensor Categories as Hilbert C*-Modules
Authors: Aaserud Andreas Næs , Evans David E.
Published: May 2020

We associate to each Temperley–Lieb–Jones C*-tensor category$${\mathcal {T}}{\mathcal {L}}{\mathcal {J}}(\delta )$$TLJ(δ)with parameter$$\delta $$δin the discrete range$$\{2\cos (\pi /(k+2)):\,k=1,2,\ldots \}\cup \{2\}$${2cos(π/(k+2)):k=1,2,…}∪{2}a certain C*-algebra$${\mathcal {B}}$$Bof compact operators. We use the unitary braiding on$${\mathcal {T}}{\mathcal {L}}{\mathcal {J}}(\delta )$$TLJ(δ)to equip the category$$\mathrm {Mod}_{{\mathcal {B}}}$$ModBof (right) Hilbert$${\mathcal {B}}$$B-modules with the structure of a braided C*-tensor category. We show that$${\mathcal {T}}{\mathcal {L}}{\mathcal {J}}(\delta )$$TLJ(δ)is equivalent, as a braided C*-tensor category, to the full subcategory$$\mathrm {Mod}_{{\mathcal {B}}}^f$$ModBfof$$\mathrm {Mod}_{{\mathcal {B}}}$$ModBwhose objects are those modules which admit a finite orthonormal basis. Finally, we indicate how these considerations generalize to arbitrary finitely generated rigid braided C*-tensor categories.
C*-Algebras of Right LCM One-Relator Monoids and Artin–Tits Monoids of Finite Type
Authors: Li Xin , Omland Tron , Spielberg Jack
Published: May 2020

We study C*-algebras generated by left regular representations of right LCM one-relator monoids and Artin–Tits monoids of finite type. We obtain structural results concerning nuclearity, ideal structure and pure infiniteness. Moreover, we compute K-theory. Based on our K-theory results, we develop a new way of computing K-theory for certain group C*-algebras and crossed products.