bluuebunny/crossref_metadata_2025_split huggingface dataset:
Rab11fip5 regulates telencephalon development via ephrinB1 recycling
Authors: Yoon Jaeho , Garo Jerlin , Lee Moonsup , Sun Jian , Hwang Yoo-Seok , Daar Ira O. 
Published: January 2021

ABSTRACT
Rab11 family-interacting protein 5 (Rab11fip5) is an adaptor protein that binds to the small GTPase Rab11, which has an important function in endosome recycling and trafficking of cellular proteins to the plasma membrane. Rab11fip5 is involved in many cellular processes, such as cytoskeleton rearrangement, iron uptake and exocytosis in neuroendocrine cells, and is also known as a candidate gene for autism-spectrum disorder. However, the role of Rab11fip5 during early embryonic development is not clearly understood. In this study, we identified Rab11fip5 as a protein that interacts with ephrinB1, a transmembrane ligand for Eph receptors. The PDZ binding motif in ephrinB1 and the Rab-binding domain in Rab11fip5 are necessary for their interaction in a complex. EphrinB1 and Rab11fip5 display overlapping expression in the telencephalon of developing amphibian embryos. The loss of Rab11fip5 function causes a reduction in telencephalon size and a decrease in the expression level of ephrinB1. Moreover, morpholino oligonucleotide-mediated knockdown of Rab11fip5 decreases cell proliferation in the telencephalon. The overexpression of ephrinB1 rescues these defects, suggesting that ephrinB1 recycling by the Rab11/Rab11fip5 complex is crucial for proper telencephalon development.
Caenorhabditis elegans establishes germline versus soma by balancing inherited histone methylation
Authors: Carpenter Brandon S. , Lee Teresa W. , Plott Caroline F. , Rodriguez Juan D. , Brockett Jovan S. , Myrick Dexter A. , Katz David J. 
Published: January 2021

ABSTRACT
Formation of a zygote is coupled with extensive epigenetic reprogramming to enable appropriate inheritance of histone methylation and prevent developmental delays. In Caenorhabditis elegans, this reprogramming is mediated by the H3K4me2 demethylase SPR-5 and the H3K9 methyltransferase, MET-2. In contrast, the H3K36 methyltransferase MES-4 maintains H3K36me2/3 at germline genes between generations to facilitate re-establishment of the germline. To determine whether the MES-4 germline inheritance pathway antagonizes spr-5; met-2 reprogramming, we examined the interaction between these two pathways. We found that the developmental delay of spr-5; met-2 mutant progeny is associated with ectopic H3K36me3 and the ectopic expression of MES-4-targeted germline genes in somatic tissues. Furthermore, the developmental delay is dependent upon MES-4 and the H3K4 methyltransferase, SET-2. We propose that MES-4 prevents crucial germline genes from being repressed by antagonizing maternal spr-5; met-2 reprogramming. Thus, the balance of inherited histone modifications is necessary to distinguish germline versus soma and prevent developmental delay.
This article has an associated ‘The people behind the papers’ interview.
Dynein-dynactin segregate meiotic chromosomes in C. elegans spermatocytes
Authors: Barbosa Daniel J. , Teixeira Vanessa , Duro Joana , Carvalho Ana X. , Gassmann Reto 
Published: January 2021

ABSTRACT
The microtubule motor cytoplasmic dynein 1 (dynein) and its essential activator dynactin have conserved roles in spindle assembly and positioning during female meiosis and mitosis, but their contribution to male meiosis remains poorly understood. Here, we characterize the G33S mutation in the C. elegans dynactin subunit DNC-1, which corresponds to G59S in human p150Glued that causes motor neuron disease. In spermatocytes, dnc-1(G33S) delays spindle assembly and penetrantly inhibits anaphase spindle elongation in meiosis I, which prevents the segregation of homologous chromosomes. By contrast, chromosomes segregate without errors in the early dnc-1(G33S) embryo. Deletion of the DNC-1 N-terminus shows that defective meiosis in dnc-1(G33S) spermatocytes is not due to the inability of DNC-1 to interact with microtubules. Instead, our results suggest that the DNC-1(G33S) protein, which is aggregation prone in vitro, is less stable in spermatocytes than the early embryo, resulting in different phenotypic severity in the two dividing tissues. Thus, the dnc-1(G33S) mutant reveals that dynein-dynactin drive meiotic chromosome segregation in spermatocytes and illustrates that the extent to which protein misfolding leads to loss of function can vary significantly between cell types.
The Murphy number: how pitch moment of inertia dictates quadrupedal walking and running energetics
Authors: Polet Delyle T. 
Published: January 2021

ABSTRACT
Many quadrupedal mammals transition from a four-beat walk to a two-beat run (e.g. trot), but some transition to a four-beat run (e.g. amble). Recent analysis shows that a two-beat run minimizes work only for animals with a small pitch moment of inertia (MOI), though empirical MOI were not reported. It was also unclear whether MOI affects gait energetics at slow speeds. Here, I show that a particular normalization of the pitch moment of inertia (the Murphy number) has opposite effects on walking and running energetics. During walking, simultaneous forelimb and hindlimb contacts dampen pitching energy, favouring a four-beat gait that can distribute expensive transfer of support. However, the required pitching of a four-beat walk becomes more expensive as Murphy number increases. Using trajectory optimization of a simple model, I show that both the walking and slow running strategies used by dogs, horses, giraffes and elephants can be explained by work optimization under their specific Murphy numbers. Rotational dynamics have been largely ignored in quadrupedal locomotion, but appear to be a central factor in gait selection.
Efficient high-voltage protection in the electric catfish
Authors: Welzel Georg , Schuster Stefan 
Published: January 2021

ABSTRACTFor thousands of years, starting with detailed accounts from ancient Egypt, the African electric catfish (Malapteruridae) has been renowned for its ability to hunt and to defend itself with powerful electric shocks. Surprisingly, the degree to which electric catfish are protected against their own or external electric shocks, how specific any protection would be to the species-specific waveform and whether a discharging catfish has to actively prepare for the onset of its high-voltage discharges has never been analysed. Here, we used digital high-speed video to record catfish during their own discharges or as they were exposed to external discharges, employing goldfish to carefully calibrate the efficiency of all discharges. Electric catfish show a remarkable degree of protection against high voltages: both self-produced and external electric shocks that heavily affected control goldfish failed to evoke involuntary muscle contraction or to affect sensorimotor processing. Even a commercial electrofishing device, set to efficiently immobilise and narcotise fish, failed to have any effect on the electric catfish. Our findings rule out several protective mechanisms and demonstrate a highly efficient and versatile shielding whose nature is presently unclear.
A Statistical Learning Approach to Personalization in Revenue Management
Authors: Chen Xi , Owen Zachary , Pixton Clark , Simchi-Levi David 
Published: January 2021

We consider a logit model-based framework for modeling joint pricing and assortment decisions that take into account customer features. This model provides a significant advantage when one has insufficient data for any one customer and wishes to generalize learning about one customer’s preferences to the population. Under this model, we study the statistical learning task of model fitting from a static store of precollected customer data. This setting, in contrast to the popular learning and earning paradigm, represents the situation many business teams encounter in which their data collection abilities have outstripped their data analysis capabilities. In this learning setting, we establish finite-sample convergence guarantees on the model parameters. The parameter convergence guarantees are then extended to out-of-sample performance guarantees in terms of revenue, in the form of a high-probability bound on the gap between the expected revenue of the best action taken under the estimated parameters and the revenue generated by a decision maker with full knowledge of the choice model. We further discuss practical implications of these bounds. We demonstrate the personalization approach using ticket purchase data from an airline carrier. This paper was accepted by J. George Shanthikumar, Management Science Special Section on Data-Driven Prescriptive Analytics.
Cheap Talk on Freelance Platforms
Authors: Ke T. Tony , Zhu Yuting 
Published: January 2021

We consider a large decentralized freelance platform where buyers with private information about their quality preferences are matched with freelancers that differ in quality. When posting their job requests, buyers can report their quality preferences via cheap talk, which influences freelancers’ application and pricing strategies. By exaggerating one’s quality preference, a buyer attracts not only more applications from freelancers, but also those with higher quality, at the cost of a higher expected price. We find that it is always an equilibrium for the buyers to report their quality preferences truthfully when they cannot renegotiate with freelancers on their asking prices after getting matched. On the other hand, when postmatch renegotiation is allowed and buyers have relatively high bargaining power, low-type buyers may strategically exaggerate their quality preferences, and subsequently after getting matched, costly signal their true type and bargain for lower prices. From a platform design perspective, our analysis implies that the option of renegotiation, designed to facilitate postmatch information transmission, may backfire by giving rise to buyers’ prematch opportunistic behaviors of information distortion. This paper was accepted by Joshua Gans, business strategy.
Turning the Tables in Research and Development Licensing Contracts
Authors: Taneri Niyazi , Crama Pascale 
Published: January 2021

Research and development (R&D) collaborations between an innovator and her partner are often undertaken when neither party can bring the product to market individually, which precludes value creation without a joint effort. Yet, the uncertain nature of R&D complicates the monitoring of effort, and the resulting moral hazard reduces a collaboration’s value. Either party can avoid this outcome by acquiring the capability that is missing and then taking sole ownership of the project. That approach involves two types of risks: one related to whether the other party’s capability will be acquired and one related to how well it will be implemented (if acquired). We find that the extent of these two risks determines the optimality of delaying contracting or of signing contracts with buyout and buyback options, a baseball arbitration clause, or a novel reciprocal option. Baseball arbitration and reciprocal option clauses are unique in two ways. First, unlike typical options with predetermined strike prices, they allow either party to determine the buyout price at the time of their offer. Second, they allow the offer’s recipient to “turn the tables” on the other party. Although baseball arbitration and reciprocal option contracts both address inefficient joint development and product allocation, they exhibit their own inefficiencies that stem from the two parties’ strategic behavior. The best choice of contract is determined by trade-offs between these inefficiencies. Our model explores the similarities between the baseball arbitration and reciprocal option clauses, and we propose a modification to the reciprocal option contract that would increase its profitability. This paper was accepted by Terry Taylor, operations management.
Delegating Innovation Projects with Deadline: Committed vs. Flexible Stopping
Authors: Rahmani Morvarid , Ramachandran Karthik 
Published: January 2021

In many contexts such as product design and development, advertising, and scouting for technical solutions, clients seek the expertise of external providers to generate innovative solutions for their business problems. Because innovation projects are beset with uncertainty, they often require multiple iterations of ideation and evaluation. Although some clients make a commitment to take the first feasible solution from the provider, other clients retain the flexibility to seek more solutions until they decide to stop the project. Which of these policies is the better way to delegate an innovation project? To answer this question, we develop game-theoretic models that capture two salient aspects of delegated innovation projects: a deadline for the project and dynamic effort adjustment by the provider. We show that the flexible stopping policy, despite its intuitive appeal, may not always benefit the client. Specifically, the committed stopping policy is optimal when the provider is highly capable of generating solutions and when the client’s cost of evaluating solutions is in an intermediate range. In such situations, the committed stopping policy provides a stronger incentive to the provider to exert costly effort early on, which improves the quality of initial solutions. Considering endogenous payments, we show that the committed policy not only mitigates the provider’s tendency to postpone effort but also does so with a smaller payment. This paper was accepted by Serguei Netessine, operations management.
One-stage revision is as effective as two-stage revision for chronic culture-negative periprosthetic joint infection after total hip and knee arthroplasty
Authors: van den Kieboom Janna , Tirumala Venkatsaiakhil , Box Hayden , Oganesyan Ruben , Klemt Christian , Kwon Young-Min 
Published: January 2021

Aims Removal of infected components and culture-directed antibiotics are important for the successful treatment of chronic periprosthetic joint infection (PJI). However, as many as 27% of chronic PJI patients yield negative culture results. Although culture negativity has been thought of as a contraindication to one-stage revision, data supporting this assertion are limited. The aim of our study was to report on the clinical outcomes for one-stage and two-stage exchange arthroplasty performed in patients with chronic culture-negative PJI. Methods A total of 105 consecutive patients who underwent revision arthroplasty for chronic culture-negative PJI were retrospectively evaluated. One-stage revision arthroplasty was performed in 30 patients, while 75 patients underwent two-stage exchange, with a minimum of one year's follow-up. Reinfection, re-revision for septic and aseptic reasons, amputation, readmission, mortality, and length of stay were compared between the two treatment strategies. Results The patient demographic characteristics did not differ significantly between the groups. At a mean follow-up of 4.2 years, the treatment failure for reinfection for one-stage and two-stage revision was five (16.7%) and 15 patients (20.0%) (p = 0.691), and for septic re-revision was four (13.3%) and 11 patients (14.7%) (p = 0.863), respectively. No significant differences were observed between one-stage and two-stage revision for 30- 60- and 90-day readmissions (10.0% vs 8.0%; p = 0.714; 16.7% vs 9.3%; p = 0.325; and 26.7% vs 10.7%; p = 0.074), one-year mortality (3.3% vs 4.0%; p > 0.999), and amputation (3.3% vs 1.3%; p = 0.496). Conclusion In this non-randomized study, one-stage revision arthroplasty demonstrated similar outcomes including reinfection, re-revision, and readmission rates for the treatment of chronic culture-negative PJI after TKA and THA compared to two-stage revision. This suggests culture negativity may not be a contraindication to one-stage revision arthroplasty for chronic culture-negative PJI in selected patients. Cite this article: Bone Joint J 2021;103-B(3):515–521.
A Novel Method of Electric Scooter Torque Estimation Using the Space Vector Modulation Control
Authors: Hichem Chergui , Abdelfatah Nasri , Kayisli Korhan 
Published: January 2021

In recent years, there are many studies have been conducted in the field of light electric vehicles, especially electric scooters. These are preferred in large urban areas that are crowded with cars and cause traffic congestion in the European and Asian continents. In this study, the three-wheel electric scooter contained two BLDC motors that drove the rear wheels and, each of these motors were controlled independently via an electronic differential. This paper aims to implement a Space Vector Modulation for the Direct Torque Control unit (SVM-DTC) of the BLDC wheel-motor of each driving wheel. The proposed system had been designed and simulated by using the MATLAB/SIMULINK environment. The performance of the overall system (scooter stability control system - energy storage system -power quality, etc.) with using SVM-DTC control was compared with the classical Direct Torque Control (DTC) algorithm by using the same electric scooter model. The obtained results showed clearly the improvement made by the proposed control loop system at different stages, where it could reduce the THD of the stator current from 30.99% to 6.16%,as well as it was able to achieve more than 0.2% of the charging state of the battery in 18 seconds only.
Palliative intraarterial chemoradiotherapy as a method of choice in the treatment of unresectable oropharyngeal tumors: a clinical case
Authors: Lutovinin R. V. , Oshchepkov V. N. , Shubina Yu. A. , Kokareva V. V. 
Published: January 2021

Introduction. Surgery is frequently preferable to therapy as it yields longer overall and recurrence-free survival. But surgery of locally advanced tumors of the oral cavity can not always guarantee preservation of oral functions. In the EORTC 24971 and RTOG 90-03 trials, effectiveness of conventional radiotherapy was demonstrated. Addition of brachytherapy allowed to double recurrence-free and overall survival. Implementation of proton therapy increased treatment safety. However, high cost of modern technology for radiotherapy limits its accessibility. Intra-arterial chemotherapy is characterized by lower toxicity. Additionally, it allows to create a pool for the 1st cycle of systemic circulation directly in the tumor and neighboring tissues, and a significant portion of the drug enters the draining lymph node replicating lymphogenic metastasis.The objective was to present a clinical case of successful treatment of inoperable squamous-cell carcinoma of the oropharynx using intra-arterial chemoradiotherapy.Clinical case. A patient sought medical help at the multidisciplinary clinical medical center “Medical City” where combination treatment was chosen: a course of chemoradiation therapy using an original approach combining external beam 3D-conformal radiotherapy and intraarterial chemotherapy. According to control computed tomography data, dynamics was described as partial response: 30 % reduction in marker lesions. The patient did not have any complaints and evaluated their quality of life as high which corresponded to the testing results.Conclusion. We have demonstrated benefits of intra-arterial chemoradiation therapy: low toxicity allows patients to receive a full course of radiotherapy without breaks and achieve high functional results. Considering palliative status of the patient, we did not aim to increase recurrence-free period but the objective of ensuring satisfactory quality of life was achieved. New, more physiological regimens of intra-arterial infusion will improve pharmacokinetic profile of chemotherapeutic drugs and will allow to achieve positive results.
The ctenophore <i>Beroe</i> cf. <i>ovata</i> in the Caspian Sea. The beginning of a new stage in the evolution of the Caspian ecosystem?
Authors: Vostokov S. V. , Gadzhiev A. A. , Vostokova A. S. , Rabazanov N. I. 
Published: January 2021

Aim. Analysis of the first data regarding the arrival of the predatory ctenophore Beroe cf. ovata in the Caspian Sea and assessment of possible effects of its introduction for the Caspian ecosystem.Material and Methods. The material was obtained in the deep-water region of the western shelf of the middle Caspian Sea in the first ten days of October 2020. Zooplankton samples were collected using a Juday plankton net (0.1 m2 opening, 180 μm mesh size). Large ctenophores were collected using a big cone plankton net (CB) with a 0.5 m2 opening, 500 μm mesh size. Samples were taken at five stations in the 0-40 m layer. Combs larger than 5 mm were counted and measured on board the ship. The number and size of small ctenophores, larvae and eggs were determined in zooplankton samples fixed with formalin to a final concentration of 4%.Results. The presence of a new alien Beroe cf. ovata was recorded in the Dagestan shelf waters of the Caspian Sea in the beginning of October 2020. The average number of Beroe cf. ovata for five stations was 22 ind/m2 and the biomass was 6.15 g/m2. Larvae and small individuals from 5 to 20 mm in size predominated. Mnemiopsis leidyi was absent in the area investigated. The structure of mesozooplankton was dominated by the small copepod Acartia tonsa, which accounted for 92% of the zooplankton community and 78% of its biomass.Conclusion. The size structure of the B. ovata population with a predominance of larvae and small individuals indicates a recently completed breeding cycle and adaptation of the ctenophore to the conditions of the Caspian Sea. The first impacts of the new invasive ctenophore on the population of M. leidyi were demonstrated. This event may be the beginning of a new stage in the evolution of the Caspian Sea ecosystem and the restoration of its bio resources affected by the invasion of Mnemiopsis leidyi. The structure of mesozooplankton with total dominance, in abundance and biomass, of the small copepod Acartia tonsa did not differ from that in the previous period, indicating that the Caspian zoocenosis did not respond to the short-term reduction of the impact of M. leidyi. A brief analysis of the history of the introduction of ctenophores to the Black and Caspian Seas is presented and their impact on ecosystems and biological resources of these seas is studied. Based on longterm observations of the invasive ctenophores' interactions in the Black Sea, the possible outcomes of the penetration of Beroe cf. ovata in the Caspian Sea are discussed.