bluuebunny/crossref_metadata_2025 huggingface dataset:
A Marcus-Hush perspective on adiabatic singlet fission
Authors: Schmidt Timothy W.
Published: August 2019

Singlet fission is a process whereby a bichromophoric system crosses from an excitonically coupled singlet state to a singlet-coupled triplet pair state. If the electronic structure is described locally, then the process may be described by a formal exchange of electrons. As such, it lends itself to a treatment rooted in the Marcus-Hush description of electron transfer. Here, we use ab initio and density functional electronic structure theories to reveal a Marcus-Hush perspective on singlet fission and propose experiments to probe singlet fission in the spirit of photo-induced electron transfer.
Ultra-local model-based control of the square-back Ahmed body wake flow
Authors: Plumejeau Baptiste , Delprat Sébastien , Keirsbulck Laurent , Lippert Marc , Abassi Wafik
Published: August 2019

This paper presents a new model-free control approach applied to a dynamical fluidic system. The main objective is to evaluate the ability of this closed-loop control technique to control the bistability of a turbulent wake flow past to a square-back Ahmed body. This bistable behavior occurs for some configurations depending mainly on the ground clearance. Due to the unsteady position of the wake vortex cores, the bistable phenomenon is responsible of a strong variation of the lateral force (drift force) and of a slight drag increase. Consequently, mitigating the wake symmetry-breaking modes can induce a substantial drag reduction. The feedback controller controls the drift using its ultralocal approximation and the estimation of its dynamics. The control signal is then applied to lateral blower actuators to suppress the spanwise bistability. The drift force is used as feedback to sense the wake flow, and concomitant velocity, forces, and pressure measurements are performed at a nominal Reynolds number of Reh = 2.86 × 105 to quantify and demonstrate the effectiveness of the present closed-loop control. Results show that for various actuation velocity ratios, the bistability suppression can lead to a drag reduction up to 2.5% with an energy consumption evaluated to be less than 0.6% of the aerodynamic power saving for the worst investigated case.
High-energy X-ray radiography investigation on the ejecta physics of laser shock-loaded tin
Authors: He Weihua , Xi Tao , Shui Min , Yu Minghai , Zhao Yongqiang , Wu Yuchi , Gu Yuqiu , Chu Genbai , Xin Jianting
Published: August 2019

This study is devoted to the high-energy X-ray radiography investigation on the ejecta physics of laser shock-loaded tin. The ejecta were generated via laser shock loaded tin under sequential shock-breakout pressures by high-power nanosecond lasers. A high-energy X-ray (50∼200keV) source was created to radiograph the high dense ejecta. Due to its strong penetration, high-quality radiograph images were obtained with detailed inner information and topology structure of ejecta. The areal density distribution and total mass of ejecta were further inferred. It was found that the ejecta from laser shock-loaded tin under sequential pressures show obvious difference in density distribution between the samples in a solid state and in a melt-on-release state. In addition, the total mass of ejecta was demonstrated to increase sharply when the breakout pressure is larger than the onset of melt-on-release for tin. Such increase inferred a solid-liquid phase transition of ejecta production mechanism.
Using quadrature and an iterative eigensolver to compute fine-structure ro-vibrational levels of Van der Waals complexes: NH(Σ−3)–He, O2(Σg−3)–Ar, and O2(Σg−3)–He
Authors: Wang Xiao-Gang , Carrington Tucker
Published: August 2019

We introduce a new method for computing spectra of molecules for which a spin-spin term in the Hamiltonian has an important effect. In previous calculations, matrix elements of the spin-spin term and of the potential were obtained by expanding the potential and using analytic equations in terms of 3–j symbols. Instead, we use quadrature. Quadrature is simple and makes it possible to do calculations with a general potential and without using the Wigner-Eckart theorem. In previous calculations, the Hamiltonian matrix was built and diagonalized. Instead, we use an iterative eigensolver. It makes it easy to work with a large basis. The ideas are tested by computing energy levels of NH(3Σ−)–He, O2(Σg−3)–Ar, and O2(Σg−3)–He.
Oscillation resonances and anisotropic damping of the motion of acoustically levitated droplets in single-axis acoustic levitators
Authors: Tsujino Soichiro , Sato Yohei , Takeda Yasushi , Tomizaki Takashi
Published: August 2019

The positional stability of acoustically levitated droplets in air and the settling time of droplet positions on loading are important for precision applications of acoustic levitation. We therefore study their dependence on ultrasound pressure for droplets with diameters 0.01–0.2 times the acoustic wavelength in a single-axis acoustic levitator operating at 39 kHz. We find that the observed resonance frequencies agree well with theory. However, the damping coefficients of the oscillations exhibit large anisotropy, and their dependence on the droplet size deviates greatly from the behavior expected from the Stokes coefficient. These results suggest that acoustic streaming plays an important role in the motion of acoustically levitated droplets.
Wall pressure and secondary-flow origination in a square duct
Authors: Dai Yi-Jun , Xu Chun-Xiao
Published: August 2019

The secondary flow of Prandtl’s second kind is a typical feature of turbulent flow in a duct with a noncircular cross section. In this paper, we proposed a physical mechanism on the formation of the secondary flow by analyzing the momentum balance along selected paths. The blocking effects of intersecting walls cause the pressure at the corner to be higher than that at the wall midpoint. Driven by the pressure gradient, fluids above the wall flow away from the corner, complemented by an inflow toward the corner along the diagonal. The proposed mechanism is confirmed using data from direct numerical simulation with the friction Reynolds number Reτ up to 900.
Enhanced thermal sensitivity of MEMS bolometers integrated with nanometer-scale hole array structures
Authors: Zhang Ya , Qiu Boqi , Nagai Naomi , Nomura Masahiro , Volz Sebastian , Hirakawa Kazuhiko
Published: August 2019

We have fabricated two-dimensional nanometer-scale hole array structures on GaAs doubly-clamped microelectromechanical system (MEMS) beam resonators to modulate their thermal properties. Owing to the reduction in the thermal conductance of the MEMS beams by introducing the hole array structures, the nano-porous MEMS bolometers show 2-3 times larger thermal sensitivities than the unpatterned reference sample. Furthermore, since the heat capacitance of the MEMS beams is also reduced by introducing the hole array, the thermal decay time of the patterned MEMS beams is increased only by about 30-50%, demonstrating the effectiveness of the hole array structures for enhancing the thermal sensitivities of bolometers without significantly deteriorating their operation bandwidths.
Study on impulse quenching based multichamber arc quenching structure
Authors: Li Zijian , Wang Jufeng , Zhou Xin , Huang Shangshi , Xia Zhijian
Published: August 2019

In order to reduce the lightning trip-out rate of grid power lines, a kind of impulse quenching based multichamber arc quenching structure (IQBMAS) is developed by the authors. This kind of MAS can attract the lightning impulse arc into its arc quenching channel and truncate the impulse arc into multiple parts rapidly. In this case, the impulse arc will not develop into steady power frequency current, so the lightning trip-out can be avoided. In this paper, simulations and experiments are conducted to verify the arc-quenching effect of IQBMAS on the basis of expounding the operating principle of IQBMAS, establishing the arc model in the channel as well as deriving the relevant numerical equations. The test result shows that IQBMAS can extinguish the power frequency arc of 10 kV lines within 1.5 ms with no reignition.
Multiband sparse signal reconstruction through direct one-bit sampling
Authors: Chen Yu , Zhao Yijiu , Huang Jianguo , Zheng Yanze
Published: August 2019

Compressive sensing (CS) aims at decreasing sampling rate to reduce the needed number of samples. On the other hand, the one-bit CS is proposed to reduce the quantization bit. In this paper, we proposed a one-bit CS system aiming at acquiring the multiband sparse signal which is a very popular signal model in wireless communication, especially in cognitive radio. This proposed system, called direct one-bit sampler (DOS), is simple in hardware implementation, and it consists of only a comparator working at Nyquist rate. In the stage of signal reconstruction, it can be equivalent to a special multicoset sampler which is a popular scheme in CS. Moreover, we propose an enhanced binary iterative hard thresholding (BIHT), a popular one-bit recovery algorithm, to deal with the multiple measurement vectors in the one-bit CS framework. Both the theoretical model and experimental results demonstrate that the proposed DOS, with the help of the enhanced BIHT, can not only accurately recover the positions of active subbands of the multiband sparse signal but also roughly estimate the power of each active subband.
Discharge-driven seasonal pattern of ionic solutes, suspended sediment and water clarity for a tropical savanna river in northern Australia
Authors: Townsend S. A.
Published: August 2019

River water quality is driven primarily by discharge and a catchment’s natural and anthropogenic features. In this study, the underpinning role of discharge in driving water quality is examined for an Australian tropical savanna river. The seventh-order Daly River has a near-natural discharge regime and catchment that is highly weathered, and has low topographic relief, with most of its natural vegetation retained. Four discharge periods are defined according to surface and groundwater water source, and the magnitude and frequency of run-off events. On a seasonal scale, the river’s water quality reflected the mix of water sources. These comprised extremes of high surface water-driven discharge, high suspended sediment concentrations and low water clarity during the wet season, and low groundwater-fed discharge during the dry season with high water clarity. The suspended sediment concentration of run-off events during the dry-to-wet transition and the wet season were directly and inversely related to event maximum discharge respectively, suggesting the exhaustion of sediment supply to the river during the wet season. Variability associated with the discharge–water quality relationships was attributed to water source, hysteresis and event magnitude and timing. Suspended sediment yields and concentrations were relatively low compared with more anthropogenically affected Australian savanna catchments.
A role for S-nitrosylation of the SUMO-conjugating enzyme SCE1 in plant immunity
Authors: Skelly Michael J. , Malik Saad I. , Le Bihan Thierry , Bo Yuan , Jiang Jihong , Spoel Steven H. , Loake Gary J.
Published: August 2019

Significance

S-nitrosylation, the addition of a nitric oxide (NO) moiety to a reactive protein cysteine (Cys) thiol to form an S-nitrosothiol (SNO), is emerging as a pivotal redox-based, posttranslational modification (PTM) during plant immune function. However, the Cys target sites of NO bioactivity and the associated consequences on cellular signaling are not well defined. Our findings suggest that S-nitrosylation of small ubiquitin-like modifier (SUMO)-conjugating enzyme 1 (SCE1) at Cys139 controls SUMOylation, a protein-based PTM that negatively regulates plant immunity through conjugation of SUMO1/2. This Cys is evolutionary conserved and specifically S-nitrosylated in the human homolog, UBC9, implying that this mechanism might be conserved across phylogenetic kingdoms.
Forecasting failure locations in 2-dimensional disordered lattices
Authors: Berthier Estelle , Porter Mason A. , Daniels Karen E.
Published: August 2019

Significance

Disordered lattices are used widely for mechanical applications because they are lightweight and robust. Due to their heterogeneous structure, it is a complicated task to understand and forecast their progressive degradation. To safely use these materials and design structures with optimized mechanical properties, it is crucial to understand where failures occur. We show that a simple test that consists of comparing the importance of a beam with respect to the other beams in a lattice permits a successful forecast of the locations of failures. It allows one to consider only a small fraction of the beams as likely failure locations. Our approach also provides a roadmap for studies of failures in other spatial networks.
Application of antihelix antibodies in protein structure determination
Authors: Kim Ji Won , Kim Songwon , Lee Haerim , Cho Geunyoung , Kim Sun Chang , Lee Hayyoung , Jin Mi Sun , Lee Jie-Oh
Published: August 2019

Antibodies are indispensable tools in protein engineering and structural biology. Antibodies suitable for structural studies should recognize the 3-dimensional (3D) conformations of target proteins. Generating such antibodies and characterizing their complexes with antigens take a significant amount of time and effort. Here, we show that we can expand the application of well-characterized antibodies by “transplanting” the epitopes that they recognize to proteins with completely different structures and sequences. Previously, several antibodies have been shown to recognize the alpha-helical conformation of antigenic peptides. We demonstrate that these antibodies can be made to bind to a variety of unrelated “off-target” proteins by modifying amino acids in the preexisting alpha helices of such proteins. Using X-ray crystallography, we determined the structures of the engineered protein–antibody complexes. All of the antibodies bound to the epitope-transplanted proteins, forming accurately predictable structures. Furthermore, we showed that binding of these antihelix antibodies to the engineered target proteins can modulate their catalytic activities by trapping them in selected functional states. Our method is simple and efficient, and it will have applications in protein X-ray crystallography, electron microscopy, and nanotechnology.
Metalloprotease inhibitor TIMP proteins control FGF-2 bioavailability and regulate skeletal growth
Authors: Saw Sanjay , Aiken Alison , Fang Hui , McKee Trevor D. , Bregant Sarah , Sanchez Otto , Chen Yan , Weiss Ashley , Dickson Brendan C. , Czarny Bertrand , Sinha Ankit , Fosang Amanda , Dive Vincent , Waterhouse Paul D. , Kislinger Thomas , Khokha Rama
Published: August 2019

Regulated growth plate activity is essential for postnatal bone development and body stature, yet the systems regulating epiphyseal fusion are poorly understood. Here, we show that the tissue inhibitors of metalloprotease (TIMP) gene family is essential for normal bone growth after birth. Whole-body quadruple-knockout mice lacking all four TIMPs have growth plate closure in long bones, precipitating limb shortening, epiphyseal distortion, and widespread chondrodysplasia. We identify TIMP/FGF-2/IHH as a novel nexus underlying bone lengthening where TIMPs negatively regulate the release of FGF-2 from chondrocytes to allow IHH expression. Using a knock-in approach that combines MMP-resistant or ADAMTS-resistant aggrecans with TIMP deficiency, we uncouple growth plate activity in axial and appendicular bones. Thus, natural metalloprotease inhibitors are crucial regulators of chondrocyte maturation program, growth plate integrity, and skeletal proportionality. Furthermore, individual and combinatorial TIMP-deficient mice demonstrate the redundancy of metalloprotease inhibitor function in embryonic and postnatal development.
A stochastic model of ion channel cluster formation in the plasma membrane
Authors: Sato Daisuke , Hernández-Hernández Gonzalo , Matsumoto Collin , Tajada Sendoa , Moreno Claudia M. , Dixon Rose E. , O’Dwyer Samantha , Navedo Manuel F. , Trimmer James S. , Clancy Colleen E. , Binder Marc D. , Santana L. Fernando
Published: August 2019

Ion channels are often found arranged into dense clusters in the plasma membranes of excitable cells, but the mechanisms underlying the formation and maintenance of these functional aggregates are unknown. Here, we tested the hypothesis that channel clustering is the consequence of a stochastic self-assembly process and propose a model by which channel clusters are formed and regulated in size. Our hypothesis is based on statistical analyses of the size distributions of the channel clusters we measured in neurons, ventricular myocytes, arterial smooth muscle, and heterologous cells, which in all cases were described by exponential functions, indicative of a Poisson process (i.e., clusters form in a continuous, independent, and memory-less fashion). We were able to reproduce the observed cluster distributions of five different types of channels in the membrane of excitable and tsA-201 cells in simulations using a computer model in which channels are “delivered” to the membrane at randomly assigned locations. The model’s three parameters represent channel cluster nucleation, growth, and removal probabilities, the values of which were estimated based on our experimental measurements. We also determined the time course of cluster formation and membrane dwell time for CaV1.2 and TRPV4 channels expressed in tsA-201 cells to constrain our model. In addition, we elaborated a more complex version of our model that incorporated a self-regulating feedback mechanism to shape channel cluster formation. The strong inference we make from our results is that CaV1.2, CaV1.3, BK, and TRPV4 proteins are all randomly inserted into the plasma membranes of excitable cells and that they form homogeneous clusters that increase in size until they reach a steady state. Further, it appears likely that cluster size for a diverse set of membrane-bound proteins and a wide range of cell types is regulated by a common feedback mechanism.
The mesospheric sodium layer and its impact on the LGS parameters
Authors: Djaidri F. , Moussaoui N.
Published: August 2019

The atmospheric turbulence limits the angular resolution of telescopes of tens of meters to that of a telescope of 20 cm diameter. Large telescopes, such as the VLT and the E-ELT, have adopted the Adaptive Optics (AO) system to reduce the undesirable effects of turbulence. The implantation of the technology of “sodium-LGSs” is essential to increase the performances of the AO. The generation of “sodium-LGSs” is the result of the fluorescence of mesospheric Na atoms located between 80 to 105 km of altitude. The laser beam sent from the ground is tuned to the wavelength 589 nm; excites the D2 line of Na. The backscattered light gives necessary information on atmospheric turbulence and their effects on the incoming wave front of an astronomical object. The mesospheric sodium layer is characterized by the abundance of Na, the centroid height and the thickness of the layer. Their behaviors affect the variations of parameters of the “sodium-LGSs”, such as the Return Flux and the elongation of the spot. The characterization of this layer is necessary in order to optimize the performance of the “LGSs-AO” system. We present semi-empirical models based on experimental measurements. These models explain the variations in the abundance and height of the centroid of the sodium layer.
The Horizon Problem
Authors: Lakhal Bahia Si , Guezmir Ameur
Published: August 2019

The standard model of cosmology describes relatively in a satisfactory way, the major stages of the evolution of the observable universe, over time. Despite its success, it presents some problems that constitute a puzzle nowadays. Among them, we cite the horizon problem, which is the purpose of this paper to study and present the different solutions that are available in the literature.

The inflationary model, originally introduced by A. Guth in 1981, was designed to solve the horizon, flatness and entropy problems. Since then, we are faced now with more than 200 inflationary models. However, space missions, for to test the validity of some cosmological models (Planck 2013, 2015…) show that the universe follows the simplest proposed inflationary theories.

In this work, we will study some models proposed as a solution to the horizon problem.
Comparison of Microwave-Assisted Digestion and Consensus Open-Vessel Digestion Procedures for Evaluation of Metalliferous Airborne Particulate Matter
Authors: Schwank Tobias , Pitzke Katrin , Gusbeth Krista , Ashley Kevin , Breuer Dietmar
Published: August 2019

Metal occupational exposure limits mainly focus on total content of the respective metals of interest. The methods applied for trace metal analysis in occupational health and safety laboratories are usually standardized to pragmatic consensus digestion schemes, ensuring comparability of results. The objective of the present study entailed the evaluation of a recently developed HNO3-only microwave-assisted digestion procedure by comparison with the German consensus hot-block digestion and other national digestion schemes. An inter-laboratory comparison test with participation of nine national occupational health and safety laboratories from Europe and North America was organized. For adequate emulation of what workers are at risk of inhaling four different industrial metal processing workplace dusts (electronic recycling, high-speed steel grinding, cylinder head cleaning, and battery combustion ash) were homogenized and sieved to the particle size < 100 µm diameter at IFA. The participants were asked to process air sample-typical amounts according to the German hot-plate technique, the IFA microwave-assisted digestion scheme as well as their national or in-house conventional digestion method for airborne dust and analyze for Cd, Co, Cr, Co, Fe, Mg, Ni, Pb, and Zn. Recoveries (relative to consensus open-vessel digestion) obtained for the new IFA microwave-assisted digestion were between 88 and 114% and relative reproducibility standard deviations were <10% for most metals of interest. The in-house digestion procedures applied varied widely but (whether microwave, hot block, or open vessel) yielded comparable results for the predominantly elemental alloy type dusts supplied. Results become more diverse for the combustion dust, especially if a combination of microwave-assisted digestion procedures with high temperatures and hydrofluoric acid is applied. ISO 15202-2 is currently being revised; this digestion procedure will be included as a possible variant in annex 2.
The Timor Sea Conciliation under Article 298 and Annex V of UNCLOS: A Critique
Authors: Liao Xuexia
Published: August 2019

This paper studies the first compulsory conciliation proceeding under Article 298 and Annex V of the United Nations Convention on the Law of the Sea. It assesses the competence and conciliation proceedings in a comprehensive manner, with a view to understanding how conciliation may contribute to settling maritime boundary disputes. This paper reviews the conciliation commission’s interpretation of Article 281, Article 298(1)(a)(i) and other relevant provisions of Annex V to UNCLOS, and discusses the question of whether a pre-existing treaty between the parties can preclude resort to compulsory conciliation under Article 298(1)(a)(i), a question largely left unanswered by the commission. Furthermore, this paper examines the conciliation proceedings and the outcomes in the light of the law of maritime delimitation.
Healthcare Workers’ Strategies for Doffing Personal Protective Equipment
Authors: Baloh Jure , Reisinger Heather Schacht , Dukes Kimberly , da Silva Jaqueline Pereira , Salehi Hugh P , Ward Melissa , Chasco Emily E , Pennathur Priyadarshini R , Herwaldt Loreen
Published: August 2019

Background

Personal protective equipment (PPE) helps protect healthcare workers (HCWs) from pathogens and prevents cross-contamination. PPE effectiveness is often undermined by inappropriate doffing methods. Our knowledge of how HCWs approach doffing PPE in practice is limited. In this qualitative study, we examine HCWs’ perspectives about doffing PPE.

Methods

Thirty participants at a Midwestern academic hospital were recruited and assigned to 1 of 3 doffing simulation scenarios: 3 mask designs (n = 10), 2 gown designs (n = 10), or 2 glove designs (n = 10). Participants were instructed to doff PPE as they would in routine practice. Their performances were video-recorded and reviewed with participants. Semistructured interviews about their doffing approaches were conducted and audio-recorded, then transcribed and thematically analyzed.

Results

Three overarching themes were identified in interviews: doffing strategies, cognitive processes, and barriers and facilitators. Doffing strategies included doffing safely (minimizing self-contamination) and doffing expediently (eg, ripping PPE off). Cognitive processes during doffing largely pertained to tracking contaminated PPE surfaces, examining PPE design cues (eg, straps), or improvising based on prior experience from training or similar PPE designs. Doffing barriers and facilitators typically related to PPE design, such as PPE fit (or lack of it) and fastener type. Some participants also described personal barriers (eg, glasses, long hair); however, some PPE designs helped mitigate these barriers.

Conclusions

Efforts to improve HCWs’ doffing performance need to address HCWs’ preferences for both safety and expediency when using PPE, which has implications for PPE design, training approaches, and hospital policies and procedures.
Viral Shedding in Recipients of Live Attenuated Influenza Vaccine in the 2016–2017 and 2017–2018 Influenza Seasons in the United Kingdom
Authors: Jackson David , Pitcher Max , Hudson Chris , Andrews Nick , Southern Jo , Ellis Joanna , Höschler Katja , Pebody Richard , Turner Paul J , Miller Elizabeth , Zambon Maria
Published: August 2019

Background

The (H1N1)pdm09 live attenuated influenza vaccine (LAIV) strain was changed for the 2017–2018 influenza season to improve viral fitness, following poor protection against (H1N1)pdm09 viruses in 2015–2016. We conducted LAIV virus shedding studies to assess the effect of this change.

Methods

Children aged 2–18 years were recruited to receive LAIV in the 2016–2017 (n = 641) and 2017–2018 (n = 362) influenza seasons. Viruses from nasal swabs taken 1, 3, and 6 days postvaccination were quantified by reverse-transcription polymerase chain reaction and area under the curve titers were determined. Presence and quantity of shedding were compared between strains and seasons with adjustment for age and prior LAIV (n = 436), inactivated seasonal vaccine (n = 100), or (H1N1)pdm09 vaccine (n = 166) receipt.

Results

(H1N1)pdm09 detection (positivity) in 2016–2017 and 2017–2018 (11.2% and 3.9%, respectively) was lower than that of H3N2 (19.7% and 18.7%, respectively) and B/Victoria (28.9% and 33.9%, respectively). (H1N1)pdm09 positivity was higher in 2016–2017 than 2017–2018 (P = .005), but within shedding-positive participants, the (H1N1)pdm09 titer increased in 2017–2018 (P = .02). H3N2 and influenza B titers were similar between seasons. Positivity declined with age, and prior vaccination reduced the likelihood of shedding influenza B but not (H1N1)pdm09.

Conclusions

The (H1N1)pdm09 titer increased in 2017–2018, indicating more efficient virus replication in shedding-positive children than the 2016–2017 strain, although overall positivity was reduced. Age and vaccination history require consideration when correlating virus shedding and protection.

Clinical Trials Registration

NCT02143882, NCT02866942, and NCT03104790.
{1,2,3}-Restricted Connectivity of $(n,k)$-Enhanced Hypercubes
Authors: Yu Hui , Yang Jiejie , Lin Limei , Huang Yanze , Li Jine , Chen Riqing
Published: August 2019

The connectivity of a graph is a classic measure for fault tolerance of the network. Restricted connectivity measure is a crucial subject for a multiprocessor system’s ability to tolerate fault processors, and improves the connectivity measurement accuracy. Furthermore, if a network possesses a restricted connectivity property, it is more reliable with a lower vertex failure rate compared with other networks. The $\left (n,k\right )$-dimensional enhanced hypercube, denoted by $Q_{n,k}$, a variant of hypercube, which is a well-known interconnection network. In this paper, we analyze the fault tolerant properties for $\left (n,k\right )$-enhanced hypercube, and establish the $1$-restricted connectivity of $Q_{n,k} (n\ge k+1)$ and $\{2,3\}$-restricted connectivity of $(n,k)$-enhanced hypercube $Q_{n,k} (n=k+1)$. Furthermore, we propose the tight upper bound of $\{2,3\}$-restricted connectivity of $Q_{n,k} (n> k+1)$. Moreover, we show many figures to better illustrate the process of the proofs.
Ovarian damage from chemotherapy and current approaches to its protection
Authors: Spears N , Lopes F , Stefansdottir A , Rossi V , De Felici M , Anderson R A , Klinger F G
Published: August 2019

Background

Anti-cancer therapy is often a cause of premature ovarian insufficiency and infertility since the ovarian follicle reserve is extremely sensitive to the effects of chemotherapy and radiotherapy. While oocyte, embryo and ovarian cortex cryopreservation can help some women with cancer-induced infertility achieve pregnancy, the development of effective methods to protect ovarian function during chemotherapy would be a significant advantage.

Objective and rationale

This paper critically discusses the different damaging effects of the most common chemotherapeutic compounds on the ovary, in particular, the ovarian follicles and the molecular pathways that lead to that damage. The mechanisms through which fertility-protective agents might prevent chemotherapy drug-induced follicle loss are then reviewed.

Search methods

Articles published in English were searched on PubMed up to March 2019 using the following terms: ovary, fertility preservation, chemotherapy, follicle death, adjuvant therapy, cyclophosphamide, cisplatin, doxorubicin. Inclusion and exclusion criteria were applied to the analysis of the protective agents.

Outcomes

Recent studies reveal how chemotherapeutic drugs can affect the different cellular components of the ovary, causing rapid depletion of the ovarian follicular reserve. The three most commonly used drugs, cyclophosphamide, cisplatin and doxorubicin, cause premature ovarian insufficiency by inducing death and/or accelerated activation of primordial follicles and increased atresia of growing follicles. They also cause an increase in damage to blood vessels and the stromal compartment and increment inflammation. In the past 20 years, many compounds have been investigated as potential protective agents to counteract these adverse effects. The interactions of recently described fertility-protective agents with these damage pathways are discussed.

Wider implications

Understanding the mechanisms underlying the action of chemotherapy compounds on the various components of the ovary is essential for the development of efficient and targeted pharmacological therapies that could protect and prolong female fertility. While there are increasing preclinical investigations of potential fertility preserving adjuvants, there remains a lack of approaches that are being developed and tested clinically.
The Image Size of Iterated Rational Maps over Finite Fields
Authors: Juul Jamie
Published: August 2019

Let $\varphi : {{\mathbb{P}}}^1( {{\mathbb{F}}}_q)\to{{\mathbb{P}}}^1( {{\mathbb{F}}}_q)$ be a rational map of degree $d>1$ on a fixed finite field. We give asymptotic formulas for the size of image sets $\varphi ^n( {{\mathbb{P}}}^1( {{\mathbb{F}}}_q))$ as a function of $n$. This is done using properties of Galois groups of iterated maps, whose connection to the size of image sets is established via the Chebotarev Density Theorem. We apply our results in the following setting. For a rational map defined over a number field, consider the reduction of the map modulo each prime of the number field. We use our results to give explicit bounds on the proportion of periodic points in the residue fields.
Seshadri Constants for Curve Classes
Authors: Fulger Mihai
Published: August 2019

We develop a local positivity theory for movable curves on projective varieties similar to the classical Seshadri constants of nef divisors. We give analogues of the Seshadri ampleness criterion, of a characterization of the augmented base locus of a big and nef divisor, and of the interpretation of Seshadri constants as an asymptotic measure of jet separation. As application, we show in any characteristic that if $C$ is a smooth curve with ample normal bundle in a smooth projective variety then the class of $C$ is in the strict interior of the Mori cone. This was conjectured by Peternell and proved by Ottem and Lau in Characteristic 0.
Sensitivity of Human Papillomavirus (HPV) Lineage and Sublineage Variant Pseudoviruses to Neutralization by Nonavalent Vaccine Antibodies
Authors: Godi Anna , Kemp Troy J , Pinto Ligia A , Beddows Simon
Published: August 2019

Natural variants of human papillomavirus (HPV) are classified into lineages and sublineages based upon whole-genome sequence, but the impact of diversity on protein function is unclear. We investigated the susceptibility of 3–8 representative pseudovirus variants of HPV16, HPV18, HPV31, HPV33, HPV45, HPV52, and HPV58 to neutralization by nonavalent vaccine (Gardasil®9) sera. Many variants demonstrated significant differences in neutralization sensitivity from their consensus A/A1 variant but these were of a low magnitude. HPV52 D and HPV58 C variants exhibited >4-fold reduced sensitivities compared to their consensus A/A1 variant and should be considered distinct serotypes with respect to nonavalent vaccine-induced immunity.
Selenoprotein P as a significant regulator of pancreatic β cell function
Authors: Saito Yoshiro
Published: August 2019

Selenoprotein P (SeP; encoded by SELENOP) is selenium (Se)-rich plasma protein that is mainly produced in the liver. SeP functions as a Se-transport protein to deliver Se from the liver to other tissues, such as the brain and testis. The protein plays a pivotal role in Se metabolism and antioxidative defense, and it has been identified as a ‘hepatokine’ that causes insulin resistance in type 2 diabetes. SeP levels are increased in type 2 diabetes patients, and excess SeP impairs insulin signalling, promoting insulin resistance. Furthermore, increased levels of SeP disturb the functioning of pancreatic β cells and inhibit insulin secretion. This review focuses on the biological function of SeP and the molecular mechanisms associated with the adverse effects of excess SeP on pancreatic β cells’ function, particularly with respect to redox reactions. Interactions between the liver and pancreas are also discussed.
Stereotactic radiotherapy using the CyberKnife is effective for local control of bone metastases from differentiated thyroid cancer
Authors: Ishigaki Takayuki , Uruno Takashi , Sugino Kiminori , Masaki Chie , Akaishi Junko , Hames Kiyomi Y , Suzuki Akifumi , Tomoda Chisato , Matsuzu Kenichi , Ohkuwa Keiko , Kitagawa Wataru , Nagahama Mitsuji , Miyazaki Shinichiro , Ito Koichi
Published: August 2019

Differentiated thyroid cancer (DTC) is associated with a good long-term prognosis, but bone metastases can adversely affect patients’ quality of life and survival. Stereotactic radiotherapy (SRT) can deliver high-dose irradiation to target lesions and it has been reported to be useful for various cancers. However, few studies have examined the efficacy of SRT for thyroid cancer. In the present study, the aim was to investigate the efficacy of SRT using the CyberKnife for bone metastases from DTC. From September 2013 to April 2018, SRT with the CyberKnife system was used to treat 60 bone metastases from DTC in 13 patients. The patients’ medical records were retrospectively reviewed to obtain information about the adverse events associated with SRT. Of the 60 lesions, 40 could be evaluated by follow-up CT for therapeutic effectiveness, and the RECIST criteria were used to assess the response. The cancers were papillary cancer in 3 patients, follicular cancer in 9 and poorly differentiated cancer in 1. SRT was delivered in 1–10 fractions, with a median dose of 27 Gy (range, 8–48 Gy). Adverse events were infrequent and mild. The median follow-up of the 40 lesions was 11 (range, 2–56) months. The responses were partial response in 2 lesions, stable disease in 37 lesions and progressive disease in 1 lesion, with a 1-year local control rate of 97.1%. The present study showed that SRT using the CyberKnife system was a feasible and effective treatment for bone metastases of DTC.
Secular dynamics of binaries in stellar clusters – II. Dynamical evolution
Authors: Hamilton Chris , Rafikov Roman R
Published: August 2019

Dense stellar clusters are natural sites for the origin and evolution of exotic objects such as relativistic binaries (potential gravitational wave sources) and blue stragglers. We investigate the secular dynamics of a binary system driven by the global tidal field of an axisymmetric stellar cluster in which the binary orbits. In a companion paper we developed a general Hamiltonian framework describing such systems. The effective (doubly-averaged) Hamiltonian derived there encapsulates all information about the tidal potential experienced by the binary in its orbit around the cluster in a single parameter Γ. Here we provide a thorough exploration of the phase-space of the corresponding secular problem as Γ is varied. We find that for Γ > 1/5 the phase-space structure and the evolution of binary orbital elements are qualitatively similar to the Lidov–Kozai problem. However, this is only one of four possible regimes, because the dynamics are qualitatively changed by bifurcations at Γ = 1/5, 0, −1/5. We show how the dynamics are altered in each regime and calculate characteristics such as the secular evolution time-scale and maximum possible eccentricity. We verify the predictions of our doubly-averaged formalism numerically and find it to be very accurate when its underlying assumptions are fulfilled, typically meaning that the secular time-scale should exceed the period of the binary around the cluster by ≳10–102 (depending on the cluster potential and binary orbit). Our results may be relevant for understanding the nature of a variety of exotic systems harboured by stellar clusters.
Hubble Frontier Field photometric catalogues of Abell 370 and RXC J2248.7−4431: multiwavelength photometry, photometric redshifts, and stellar properties
Authors: Bradač Maruša , Huang Kuang-Han , Fontana Adriano , Castellano Marco , Merlin Emiliano , Amorín Ricardo , Hoag Austin , Strait Victoria , Santini Paola , Ryan Russell E , Casertano Stefano , Lemaux Brian C , Lubin Lori M , Schmidt Kasper B , Schrabback Tim , Treu Tommaso , von der Linden Anja , Mason Charlotte A , Wang Xin
Published: August 2019

This paper presents multiwavelength photometric catalogues of the last two Hubble Frontier Fields (HFFs), the massive galaxy clusters Abell 370 and RXC J2248.7−4431. The photometry ranges from imaging performed on the Hubble Space Telescope to ground-based Very Large Telescope and Spitzer/Infrared Array Camera, in collaboration with the ASTRODEEP team, and using the ASTRODEEP pipeline. While the main purpose of this paper is to release the catalogues, we also perform, as a proof of concept, a brief analysis of z > 6 objects selected using dropout method, as well as spectroscopically confirmed sources and multiple images in both clusters. While dropout methods yield a sample of high-z galaxies, the addition of longer wavelength data reveals that as expected the samples have substantial contamination at the ∼30–45 per cent level by dusty galaxies at lower redshifts. Furthermore, we show that spectroscopic redshifts are still required to unambiguously determine redshifts of multiply imaged systems. Finally, the now publicly available ASTRODEEP catalogues were combined for all HFFs and used to explore stellar properties of a large sample of 20 000 galaxies across a large photometric redshift range. The powerful magnification provided by the HFF clusters allows for an exploration of the properties of galaxies with intrinsic stellar masses as low as M* ≳ 107 M⊙ and intrinsic star formation rates ∼0.1–1 M⊙ yr−1 at z > 6.
Can intrinsic alignments of elongated low-mass galaxies be used to map the cosmic web at high redshift?
Authors: Pandya Viraj , Primack Joel , Behroozi Peter , Dekel Avishai , Zhang Haowen , Eckholm Elliot , Faber Sandra M , Ferguson Henry C , Giavalisco Mauro , Guo Yicheng , Hathi Nimish , Kodra Dritan , Koekemoer Anton M , Koo David C , Newman Jeffrey , van der Wel Arjen
Published: August 2019

Hubble Space Telescope observations show that low-mass ($M_*=10^9\!-\!10^{10}\, \mathrm{M}_{\odot }$) galaxies at high redshift (z = 1.0–2.5) tend to be elongated (prolate) rather than disky (oblate) or spheroidal. This is explained in zoom-in cosmological hydrodynamical simulations by the fact that these galaxies are forming in cosmic web filaments where accretion happens preferentially along the direction of elongation. We ask whether the elongated morphology of these galaxies allows them to be used as effective tracers of cosmic web filaments at high redshift via their intrinsic alignments. Using mock light cones and spectroscopically confirmed galaxy pairs from the Cosmic Assembly Near-infared Deep Extragalactic Legacy Survey (CANDELS), we test two types of alignments: (1) between the galaxy major axis and the direction to nearby galaxies of any mass and (2) between the major axes of nearby pairs of low-mass, likely prolate, galaxies. The mock light cones predict strong signals in 3D real space, 3D redshift space, and 2D projected redshift space for both types of alignments (assuming prolate galaxy orientations are the same as those of their host prolate haloes), but we do not detect significant alignment signals in CANDELS observations. However, we show that spectroscopic redshifts have been obtained for only a small fraction of highly elongated galaxies, and accounting for spectroscopic incompleteness and redshift errors significantly degrades the 2D mock signal. This may partly explain the alignment discrepancy and highlights one of several avenues for future work.
On the dust temperatures of high-redshift galaxies
Authors: Liang Lichen , Feldmann Robert , Kereš Dušan , Scoville Nick Z , Hayward Christopher C , Faucher-Giguère Claude-André , Schreiber Corentin , Ma Xiangcheng , Hopkins Philip F , Quataert Eliot
Published: August 2019

Dust temperature is an important property of the interstellar medium (ISM) of galaxies. It is required when converting (sub)millimetre broad-band flux to total infrared luminosity (LIR), and hence star formation rate, in high-redshift galaxies. However, different definitions of dust temperatures have been used in the literature, leading to different physical interpretations of how ISM conditions change with, e.g. redshift and star formation rate. In this paper, we analyse the dust temperatures of massive ($M_{\rm star} \gt 10^{10}\, \mathrm{M}_{\odot }$) $z$ = 2–6 galaxies with the help of high-resolution cosmological simulations from the Feedback in Realistic Environments (fire) project. At $z$ ∼ 2, our simulations successfully predict dust temperatures in good agreement with observations. We find that dust temperatures based on the peak emission wavelength increase with redshift, in line with the higher star formation activity at higher redshift, and are strongly correlated with the specific star formation rate. In contrast, the mass-weighted dust temperature, which is required to accurately estimate the total dust mass, does not strongly evolve with redshift over $z$ = 2–6 at fixed IR luminosity but is tightly correlated with LIR at fixed $z$. We also analyse an ‘equivalent’ dust temperature for converting (sub)millimetre flux density to total IR luminosity, and provide a fitting formula as a function of redshift and dust-to-metal ratio. We find that galaxies of higher equivalent (or higher peak) dust temperature (‘warmer dust’) do not necessarily have higher mass-weighted temperatures. A ‘two-phase’ picture for interstellar dust can explain the different scaling relations of the various dust temperatures.
Modelling Kepler eclipsing binaries: homogeneous inference of orbital and stellar properties
Authors: Windemuth D , Agol E , Ali A , Kiefer F
Published: August 2019

We report on the properties of eclipsing binaries (EBs) from the Kepler mission with a newly developed photometric modelling code, which uses the light curve, spectral energy distribution of each binary, and stellar evolution models to infer stellar masses without the need for radial velocity (RV) measurements. We present solutions and posteriors to orbital and stellar parameters for 728 systems, forming the largest homogeneous catalogue of full Kepler binary parameter estimates to date. Using comparisons to published RV measurements, we demonstrate that the inferred properties (e.g. masses) are reliable for well-detached main-sequence (MS) binaries, which make up the majority of our sample. The fidelity of our inferred parameters degrades for a subset of systems not well described by input isochrones, such as short-period binaries that have undergone interactions, or binaries with post-MS components. Additionally, we identify 35 new systems which show evidence of eclipse timing variations, perhaps from apsidal motion due to binary tides or tertiary companions. We plan to subsequently use these models to search for and constrain the presence of circumbinary planets in Kepler EB systems.
Dark matter bars in spinning haloes
Authors: Collier Angela , Shlosman Isaac , Heller Clayton
Published: August 2019

We study non-linear response of spinning dark matter (DM) haloes to dynamic and secular evolution of stellar bars in the embedded galactic discs, using high-resolution numerical simulations. For a sequence of haloes with the cosmological spin parameter λ = 0–0.09, and a representative angular momentum distribution, we analyse evolution of induced DM bars amplitude and quantify parameters of the response as well as trapping of DM orbits and angular momentum transfer by the main and secondary resonances. We find that (1) maximal amplitude of DM bars depends strongly on λ, while that of the stellar bars is indifferent to λ; (2) efficiency of resonance trapping of DM orbits by the bar increases with λ, and so is the mass and the volume of DM bars; (3) contribution of resonance transfer of angular momentum to the DM halo increases with λ, and for larger spin, the DM halo ‘talks’ to itself, by moving the angular momentum to larger radii – this process is maintained by resonances; and (4) prograde and retrograde DM orbits play different roles in angular momentum transfer. The ‘active’ part of the halo extends well beyond the bar region, up to few times the bar length in equatorial plane and away from this plane. (5) We model evolution of discless DM haloes and haloes with frozen discs, and found them to be perfectly stable to any Fourier modes. Finally, further studies adopting a range of mass and specific angular momentum distributions of the DM halo will generalize the dependence of DM response on the halo spin and important implications for direct detection of DM and that of the associated stellar tracers, such as streamers.