bluuebunny/crossref_metadata_2025 huggingface dataset:
The Parameter-Fitness Landscape of
lexA
Autoregulation in Escherichia coli
Authors: Kozuch Beverley C. , Shaffer Marla G. , Culyba Matthew J.
Published: August 2020

Feedback mechanisms are critical to control physiological responses. In gene regulation, one important example, termed negative autoregulation (NAR), occurs when a transcription factor (TF) inhibits its own production. NAR is common across the tree of life, enabling rapid homeostatic control of gene expression. NAR behavior can be described in accordance with its core biochemical parameters, but how constrained these parameters are by evolution is unclear. Here, we describe a model genetic network controlled by an NAR circuit within the bacterium
Escherichia coli
and elucidate these constraints by experimentally changing a key parameter and measuring its effect on circuit response and fitness. This analysis yielded a parameter-fitness landscape representing the genetic network, providing a window into what gene-environment conditions favor evolution of this regulatory strategy.
Fifteen-minute consultation: The toddler’s fracture
Authors: Wijtzes Nils , Jacob Hannah , Knight Katie , Thust Steffi , Hann Gayle
Published: August 2020

The toddler’s fracture is a distinct entity among tibial shaft fractures. It is defined as a minimally displaced or undisplaced spiral fracture, usually affecting the distal shaft of the tibia, with an intact fibula. They are often difficult to diagnose due to the absence of witnessed trauma and because initial radiographs may appear normal. Moreover, the presenting complaint (a non-weight bearing child) has a wide differential diagnosis. A detailed history and examination, together with additional imaging and other investigations, is crucial to diagnose a toddler’s fracture. Analgesia and immobilisation are the mainstays of treatment, with follow-up in fracture clinic recommended. Inflicted injury (Note: this article will use the term inflicted injury which is also called non-accidental injury. In the field of safeguarding, there is a move away from using the term ‘non-accidental injury’ due to misinterpretation of the term as being less serious than ‘abusive injury’ and that in child protection reports the term can be easily misread or mistyped as ‘accidental’ injury) should always be considered when red flags for child abuse are present. In this article, we aim to cover the differential diagnoses for toddler’s fracture including indicators that might suggest an inflicted injury.
Parvovirus B19 infection masquerading as relapsed acute lymphoblastic leukaemia following haematopoietic stem cell transplantation
Authors: Larkin Trisha , Li Peng , Horn Biljana
Published: August 2020

A 7-year-old boy presented with a constellation of bone pain, a skeletal lesion, and pancytopenia after undergoing allogeneic haematopoietic stem cell transplantation for recurrent acute B-cell lymphoblastic leukaemia. Investigations to rule out leukaemia recurrence were unremarkable. Due to presence of maturation arrest in erythropoiesis with giant pronormoblasts and aberrant intranuclear inclusions on a bone marrow aspirate, parvovirus B19 (PVB-19) staining was completed and confirmed the diagnosis of disseminated PVB-19. Though PVB-19 infection after solid organ transplantation was reported in the literature as early as 1986, acquired PVB-19 viremia presenting with a solitary bone lesion is a novel presentation in paediatrics.
Chronic hospital nurse understaffing meets COVID-19: an observational study
Authors: Lasater Karen B , Aiken Linda H , Sloane Douglas M , French Rachel , Martin Brendan , Reneau Kyrani , Alexander Maryann , McHugh Matthew D
Published: August 2020

Introduction

Efforts to enact nurse staffing legislation often lack timely, local evidence about how specific policies could directly impact the public’s health. Despite numerous studies indicating better staffing is associated with more favourable patient outcomes, only one US state (California) sets patient-to-nurse staffing standards. To inform staffing legislation actively under consideration in two other US states (New York, Illinois), we sought to determine whether staffing varies across hospitals and the consequences for patient outcomes. Coincidentally, data collection occurred just prior to the COVID-19 outbreak; thus, these data also provide a real-time example of the public health implications of chronic hospital nurse understaffing.

Methods

Survey data from nurses and patients in 254 hospitals in New York and Illinois between December 2019 and February 2020 document associations of nurse staffing with care quality, patient experiences and nurse burnout.

Results

Mean staffing in medical-surgical units varied from 3.3 to 9.7 patients per nurse, with the worst mean staffing in New York City. Over half the nurses in both states experienced high burnout. Half gave their hospitals unfavourable safety grades and two-thirds would not definitely recommend their hospitals. One-third of patients rated their hospitals less than excellent and would not definitely recommend it to others. After adjusting for confounding factors, each additional patient per nurse increased odds of nurses and per cent of patients giving unfavourable reports; ORs ranged from 1.15 to 1.52 for nurses on medical-surgical units and from 1.32 to 3.63 for nurses on intensive care units.

Conclusions

Hospital nurses were burned out and working in understaffed conditions in the weeks prior to the first wave of COVID-19 cases, posing risks to the public’s health. Such risks could be addressed by safe nurse staffing policies currently under consideration.
British Thoracic Society Quality Standards for outpatient management of pulmonary embolism
Authors: Condliffe Robin , Albert Paul , Alikhan Raza , Gee Emma , Horner Daniel , Hunter Laura , Jacobs Phillip , Limbrey Rachel , Newnham Michael , Preston Wendy , Patel Sheena , Smith Laura-Jane , Suntharalingam Jay
Published: August 2020

Introduction

The purpose of the quality standards document is to provide healthcare professionals, commissioners, service providers and patients with a guide to standards of care that should be met for outpatient management of pulmonary embolism in the UK, together with measurable markers of good practice. Quality statements are based on the British Thoracic Society (BTS) Guideline for the Initial Outpatient Management of Pulmonary Embolism.

Methods

Development of BTS Quality Standards follows the BTS process of quality standard production based on the National Institute for Health and Care Excellence process manual for the development of quality standards.

Results

Six quality statements have been developed, each describing a standard of care for the outpatient management of pulmonary embolism in the UK, together with measurable markers of good practice.

Discussion

BTS Quality Standards for Outpatient Management of Pulmonary Embolism form a key part of the range of supporting materials that the society produces to assist in the dissemination and implementation of a guideline’s recommendations.
Complication rate of ultrasound-guided paravertebral block for breast surgery
Authors: Niesen Adam D , Jacob Adam K , Law Luke A , Sviggum Hans P , Johnson Rebecca L
Published: August 2020

Background and objectives

Thoracic paravertebral blockade is often used as an anesthetic and/or analgesic technique for breast surgery. With ultrasound guidance, the rate of complications is speculated to be lower than when using landmark-based techniques. This investigation aimed to quantify the incidence of pleural puncture and pneumothorax following non-continuous ultrasound-guided thoracic paravertebral blockade for breast surgery.

Methods

Patients who received thoracic paravertebral blockade for breast surgery were identified by retrospective query of our institution’s electronic database over a 5-year period. Data collected included patient demographics, level of block, type and volume of local anesthetic, occurrence of pleural puncture, occurrence of pneumothorax, evidence of local anesthetic toxicity, and patient vital signs. The incidence of block complications, including pleural puncture, pneumothorax, and local anesthetic toxicity, were ascertained.

Results

529 patients underwent 2163 thoracic paravertebral injections. Zero pleural punctures were identified during block performance; however, two patients were found to have a pneumothorax on postoperative chest X-ray (3.6 per 1000 surgeries, 95% CI 0.5 to 13.6; 0.9 per 1000 levels blocked, 95% CI 0.1 to 3.3). There were no cases of local anesthetic systemic toxicity or associated lipid emulsion therapy administration.

Conclusions

Pneumothorax following non-continuous ultrasound-guided thoracic paravertebral block using a parasagittal approach is an uncommon occurrence, with a similar rate to pneumothorax following breast surgery alone.
Static liquefaction behaviour of gold mine tailings
Authors: Riveros Guillermo A. , Sadrekarimi Abouzar
Published: August 2020

Static liquefaction failure of tailings impoundments has been a persistent issue for the mining industry for many decades. In this study, the monotonic shearing response and instability of gold tailings are examined through a series of constant-volume and drained direct simple shear tests on slurry-deposited and moist-tamped specimens. The experiments were carried out on both the silt and the sand tailings produced at the mill and separated for use in dam construction. Laboratory shear wave velocity measurements made by means of bender element tests were also used to relate the shearing response and strength of the tailings to an in situ geophysical measurement. Specimen fabric differences produced by the different preparation methods do not translate into significant differences in the critical state line, liquefaction triggering or post-liquefaction strength for the sand tailings. Additionally, common trends of undrained yield and post-liquefaction strength ratios with state parameter were observed for both the sand and the silt tailings despite their different fines contents. An empirical method to evaluate the onset of instability and the post-liquefaction strength of the tailings using shear wave velocity is proposed.
Role of 7-chloro-4-(phenylselanyl) quinoline in the treatment of oxaliplatin-induced hepatic toxicity in mice
Authors: Lemos Briana B. , Motta Ketlyn P. da , Paltian Jaini J. , Reis Angélica S. , Blödorn Gustavo B. , Soares Mauro P. , Alves Diego , Luchese Cristiane , Wilhelm Ethel A.
Published: August 2020

There is an increasing incidence of hepatotoxicity induced by oxaliplatin (OXA); therefore, researchers’ attention has been drawn to therapeutic alternatives that may decrease OXA-induced hepatotoxicity. Studies indicate that oxidative stress plays a major role in OXA-induced liver injury. As several pharmacological effects of 7-chloro-4-(phenylselanyl) quinole (4-PSQ) involve its antioxidant action, the hypothesis that this organoselenium compound could be promising for the treatment or prevention of hepatotoxicity induced by treatment with OXA was investigated. To test this hypothesis, male Swiss mice received OXA (10 mg·kg–1) on days 0 and 2, followed by oral administration of 4-PSQ (1 mg·kg–1) on days 2 to 14. 4-PSQ reduced the plasma aspartate, and alanine aminotransferase activity increased by exposure to OXA. The histopathological examination of the liver showed that 4-PSQ markedly improved OXA-induced hepatic injury. In addition, treatment with 4-PSQ reduced the oxidation of lipids and proteins (thiobarbituric acid reactive species levels and protein carbonyl content) and attenuated the increase of hepatic catalase and glutathione peroxidase activity caused by OXA. The inhibition of hepatic δ-aminolevulinic dehydratase activity induced by OXA was reverted by 4-PSQ. In conclusion, results indicate that 4-PSQ may be a good therapeutic strategy for attenuating OXA-induced liver damage.
Functional differentiation of nitrate-reducing isolates regulated by long-term fertilization in a rice paddy soil
Authors: Chen Xing , Liu Yi , Liu Chunmei , Zhang Wenzhao , Qin Hongling , Sheng Rong , Wei Wenxue
Published: August 2020

Fertilization can cause obvious shifts in nitrate-reducing community composition in agricultural ecosystems; however, little is known about the behaviors and functional characters of isolated nitrate reducers adapted to a specific environment. In this study, 849 nitrate-reducing bacteria were isolated from various fertilization treatments in a long-term paddy field experiment; the isolates were further characterized in functions with both culture-dependent and independent methodologies. The results showed that CK (no fertilizer) treatment had four genera with even relative abundance, whereas the other three treatments had their own predominant genera with Chromobacterium in nitrogen (N) fertilizer, Serratia in NPK (nitrogen, phosphorus, and potassium fertilizer) and Enterobacter in NPKC treatment (NPK plus rice straw). The isolates of Serratia and Enterobacter grew faster and produced significantly more nitrites than those of Chromobacterium and Burkholderia in the normal growth medium, suggesting that the dominant isolates from nutrient-rich environment, such as NPK and NPKC treatments, are better adapted to high nutritional conditions. On the contrary, the strains of Chromobacterium and Burkholderia possessed stronger nitrite production ability in comparison with the isolates of Serratia and Enterobacter in the diluted growth medium, indicating that the selected isolates from CK and N treatments have the capability to develop under nutrient-limiting conditions. Our results indicated that the behaviors and functions of nitrate reducers appears to be important in adapting to their dwelling habitats.
A review of natural disturbances to inform implementation of ecological forestry in Nova Scotia, Canada
Authors: Taylor Anthony R. , MacLean David A. , Neily Peter D. , Stewart Bruce , Quigley Eugene , Basquill Sean P. , Boone Celia K. , Gilby Derek , Pulsifer Mark
Published: August 2020

Like many jurisdictions across North America, the province of Nova Scotia (NS) is faced with the challenge of restoring its forests to a more natural, presettlement state through implementation of ecological forestry. At the core of ecological forestry is the idea that natural forest structures and processes may be approximated by designing management practices that emulate natural disturbances. Successful natural disturbance emulation depends on fundamental knowledge of disturbance characteristics, including identification of specific disturbance agents, their spatial extent, severity, and return interval. To date, no comprehensive synthesis of existing data has been undertaken to document the natural disturbance regime of NS forests, limiting the application of natural disturbance emulation. Using over 300 years of documents and available data, we identified the main natural disturbance agents that affect NS forests and characterized their regimes. Overall, fire, wind (predominantly hurricanes), and outbreaks of spruce budworm (Choristoneura fumiferana (Clemens)) are the most important disturbance agents, causing substantial areas of low- (<30% mortality), moderate- (30%–60%), and high- (>60%) severity disturbance. While characterization of natural historic fire is challenging, due to past human ignitions and suppression, we estimated that the mean annual disturbance rate of moderate- to high-severity fire ranged between 0.17% and 0.4%·year−1 (return interval of 250–600 years), depending on ecosystem type. Hurricanes make landfall in NS, on average, every 7 years, resulting in wide-scale (>500 ha) forest damage. While hurricane track and damage severity vary widely among storms, the return interval of low- to high-severity damage is 700–1250 years (0.14%–0.08%·year−1). Conversely, the return interval of host-specific spruce budworm outbreaks is much shorter (<50 years) but more periodic, causing wide-scale, low- to high-severity damage to spruce–fir forests every 30–40 years. Further disturbance agents such as other insects (e.g., spruce beetle), diseases, ice storms, drought, and mammals can be locally important and (or) detrimental to individual tree species but contribute little to overall disturbance in NS. Climate change is expected to significantly alter the disturbance regime of NS, affecting current disturbances (e.g., increased fire) and driving the introduction of novel agents (e.g., hemlock wooly adelgid), and continued monitoring is needed to understand these changes.
QCD sum rule studies on the $$s s {\bar{s}} {\bar{s}}$$ tetraquark states of $$J^{PC} = 0^{-+}$$
Authors: Dong Rui-Rui , Su Niu , Chen Hua-Xing , Cui Er-Liang , Zhou Zhi-Yong
Published: August 2020

We apply the method of QCD sum rules to study the $$s s {\bar{s}} {\bar{s}}$$sss¯s¯ tetraquark states of $$J^{PC} = 0^{-+}$$JPC=0-+. We construct all the relevant $$s s {\bar{s}} {\bar{s}}$$sss¯s¯ tetraquark currents, and find that there are only two independent ones. We use them to further construct two weakly-correlated mixed currents. One of them leads to reliable QCD sum rule results and the mass is extracted to be $$2.51^{+0.15}_{-0.12}$$2.51-0.12+0.15 GeV, suggesting that the X(2370) or the X(2500) can be explained as the $$ss{\bar{s}}{\bar{s}}$$sss¯s¯ tetraquark state of $$J^{PC} = 0^{-+}$$JPC=0-+. To verify this interpretation, we propose to further study the $$\pi \pi /K {\bar{K}}$$ππ/KK¯ invariant mass spectra of the $$J/\psi \rightarrow \gamma \pi \pi \eta ^\prime /\gamma K {\bar{K}} \eta ^\prime $$J/ψ→γππη′/γKK¯η′ decays in BESIII to examine whether there exists the $$f_0(980)$$f0(980) resonance.
DETERMINANTS OF CREDIT RISK: A COMPARATIVE ANALYSIS BETWEEN ISLAMIC AND CONVENTIONAL BANKS IN BANGLADESH
Authors: KABIR MD. NURUL , DULAL MIAH MOHAMMAD , HUDA RUBAIYA NADIA
Published: August 2020

The paper investigates the determinants of credit risk of Islamic and conventional banks in Bangladesh. In so doing, it collects data from 30 private commercial banks comprising of seven Islamic banks and 23 conventional banks for the period 2001–2018. Collected data are analyzed using GMM estimation technique. This method is perceived to be robust because it reduces the endogeneity problem that exists in the panel data set. Analysis of data shows that among the macro-economic variables, GDP growth decreases credit risk, whereas real interest rate and inflation increase credit risk. Bank-specific variables prove that both clusters of banks suffer from adverse selection and moral hazard problems. Results also indicate that competition has a risk-enhancing effect on banks, which supports the competition-fragility nexus. Further analysis shows that board size and board independence affect the credit risk of both clusters of banks. Findings of this study suggest some policy implications from macro, bank and governance perspectives. Specifically, banks should adopt ‘speed limit’ policy to reduce the poor quality loan. Also, competition in the banking industry should be regulated. Finally, central bank should maintain uniform capital adequacy ratio for both clusters of banks. Although this study is limited to private commercial banks in Bangladesh, the results can be generalized for other emerging economies.
FORECASTING FOREIGN EXCHANGE RESERVES USING BAYESIAN MODEL AVERAGING-NAÏVE BAYES
Authors: SALAS BELÉN , ALAMINOS DAVID , FERNÁNDEZ-GÁMEZ MANUEL A. , CALLEJÓN ÁNGELA
Published: August 2020

Foreign exchange reserves are used by governments to balance international payments and make stable the exchange rate. Numerous works have developed models to predict foreign exchange reserves; however, the existing models have limitations and the literature demands more research on the subject given that the accuracy of the models is still poor, and they have only been used for emerging countries. This paper presents a new prediction model of foreign exchange reserves for both emerging countries and developed countries, applying a method of Bayesian model averaging-Naïve Bayes, which shows better precision results than the individual classifier. Our model has a great potential impact on the adequacy of macroeconomic policy against the risks derived from balance of payment crises providing tools that help to achieve financial stability on a global level.
On the limiting energy of the collision of elementary particles close to horizon of the rotating black hole
Authors: Grib A. A. , Pavlov Yu. V.
Published: August 2020

Arguments are given for the conclusion that the energy of collision of two ultrarelativistic elementary particles due to gravitational radiation cannot exceed the Planck value. Comparison of the gravitational and electromagnetic radiation for charged particles close to the horizon of Kerr black hole is made. If for trans-Planckian energy the black hole can arise it is shown that the energy growth used in scattering for interaction of particles is still limited.
Analyzing the association between dose-volume parameters and radiation-induced brain edema in patients with brain tumor receiving stereotactic radiosurgery
Authors: Hsieh Yang-Wei , Shieh Chin-Shiuh , Huang Tai-Lin , Yeh Shyh-An , Tseng Yi-Kuan , Chao Pei-Ju , Tseng Chin-Dar , Huang Yu-Jie , Lee Tsair-Fwu
Published: August 2020

In this paper, three-dimensional images were used to analyze the association between dose-volume parameters and radiation-induced brain edema in patients with a brain tumor after receiving stereotactic radiosurgery (SRS). The computed tomography (CT), magnetic resonance images (MRI) and treatment parameters were transferred through the treatment planning system (Multiplan, version 5.1.3). The correlation between the dose of radiation therapy and brain edema was evaluated by image processing methods, such as image normalization, registration, filtering, segmentation, and feature extraction. The association was evaluated by volume index and intersection index. The study results suggest that the volume receiving radiation dose above 30% of the prescribed dose is highly associated with the brain edema in brain tumor patients after SRS. The small number of patients limits the study. Further investigation with larger populations and long-term epidemiological studies are required.
Design the encoder inspection system based on the voltage wave form using finite impulse response (FIR) filter
Authors: Viet Dang-Thai
Published: August 2020

Encoder is the measurement device that plays an important role in the electronic industry. In the process of manufacturing, the current mechanical testing methods are not of very high accuracy or are having problems in data processing algorithms. In this paper, the author represents a method for the testing mechanical work of an encoder product by measuring the torque induced by rotating the encoder. The advantages of this method are the high accuracy, stability and low cost. The accuracy of this method can go upto 95–98%. The measurement system uses LabView software as the data processing application and NI instruments as the data acquisition tools.
Decay of correlation rate in the mean field limit of point vortices ensembles
Authors: Grotto Francesco , Romito Marco
Published: August 2020

We consider the Mean Field limit of Gibbsian ensembles of 2-dimensional (2D) point vortices on the torus. It is a classical result that in such limit correlations functions converge to 1, that is, point vortices decorrelate: We compute the rate at which this convergence takes place by means of Gaussian integration techniques, inspired by the correspondence between the 2D Coulomb gas and the Sine-Gordon Euclidean field theory.
ASIE
Authors: Kang Ziyang , Wang Lei , Guo Shasha , Gong Rui , Li Shiming , Deng Yu , Xu Weixia
Published: August 2020

Neuromorphic computing based on spiking neural network (SNN) shows good energy-efficiency. However, it is inefficient for SNN to perform the convolution based on frame. It may contain a lot of redundant information in the frame. The output of Dynamic Vision Sensors (DVS) is a stream event based on Address Event Representation (AER). The asynchronous nature of AER events makes the event-based convolution reflect the characteristics of SNN low energy consumption. This article presents an SNN hardware inference engine based on an asynchronous Processing Element (PE) array with AER events as input. The engine uses a convolution algorithm based on AER events. This design also uses distributed storage in the PE array to store the state of neurons to reduce the cost of memory access. The experimental results show that the design can achieve a recognition accuracy of 98.0% for the MNIST AER dataset. The design can perform the reference process more efficiently in the case where the accuracy of the loss is negligible. During the filling and draining processes of the systolic array, the number of active PE units in our PE array is reduced and, thus, the average power consumption per PE unit is drastically decreased.
Inter-kernel Reuse-aware Thread Block Scheduling
Authors: Huzaifa Muhammad , Alsop Johnathan , Mahmoud Abdulrahman , Salvador Giordano , Sinclair Matthew D. , Adve Sarita V.
Published: August 2020

As GPUs have become more programmable, their performance and energy benefits have made them increasingly popular. However, while GPU compute units continue to improve in performance, on-chip memories lag behind and data accesses are becoming increasingly expensive in performance and energy. Emerging GPU coherence protocols can mitigate this bottleneck by exploiting data reuse in GPU caches across kernel boundaries. Unfortunately, current GPU thread block schedulers are typically not designed to expose such reuse. This article proposes new hardware thread block schedulers that optimize inter-kernel reuse while using work stealing to preserve load balance. Our schedulers are simple, decentralized, and have extremely low overhead. Compared to a baseline round-robin scheduler, the best performing scheduler reduces average execution time and energy by 19% and 11%, respectively, in regular applications, and 10% and 8%, respectively, in irregular applications.
Energy-Efficient GPU L2 Cache Design Using Instruction-Level Data Locality Similarity
Authors: Tan Jingweijia , Yan Kaige , Song Shuaiwen Leon , Fu Xin
Published: August 2020

This article presents a novel energy-efficient cache design for massively parallel, throughput-oriented architectures like GPUs. Unlike L1 data cache on modern GPUs, L2 cache shared by all of the streaming multiprocessors is not the primary performance bottleneck, but it does consume a large amount of chip energy. We observe that L2 cache is significantly underutilized by spending 95.6% of the time storing useless data. If such “dead time” on L2 is identified and reduced, L2’s energy efficiency can be drastically improved. Fortunately, we discover that the SIMT programming model of GPUs provides a unique feature among threads: instruction-level data locality similarity, which can be used to accurately predict the data re-reference counts at L2 cache block level. We propose a simple design that leverages this
Lo
cality
S
imilarity to build an energy-efficient GPU L2
Cache
, named
LoSCache
. Specifically, LoSCache uses the data locality information from a small group of cooperative thread arrays to dynamically predict the L2-level data re-reference counts of the remaining cooperative thread arrays. After that, specific L2 cache lines can be powered off if they are predicted to be “dead” after certain accesses. Experimental results on a wide range of applications demonstrate that our proposed design can significantly reduce the L2 cache energy by an average of 64% with only 0.5% performance loss. In addition, LoSCache is cost effective, independent of the scheduling policies, and compatible with the state-of-the-art L1 cache designs for additional energy savings.
CoNFV
Authors: Zhang Xuzhi , Shao Xiaozhe , Provelengios George , Dumpala Naveen Kumar , Gao Lixin , Tessier Russell
Published: August 2020

Network function virtualization (NFV) is a powerful networking approach that leverages computing resources to perform a time-varying set of network processing functions. Although microprocessors can be used for this purpose, their performance limitations and lack of specialization present implementation challenges. In this article, we describe a new heterogeneous hardware-software NFV platform called CoNFV that provides scalability and programmability while supporting significant hardware-level parallelism and reconfiguration. Our computing platform takes advantage of both field-programmable gate arrays (FPGAs) and microprocessors to implement numerous virtual network functions (VNF) that can be dynamically customized to specific network flow needs. The most distinctive feature of our system is the use of global network state to coordinate NFV operations. Traffic management and hardware reconfiguration functions are performed by a global
coordinator
that allows for the rapid sharing of network function states and continuous evaluation of network function needs. With the help of state sharing mechanism offered by the coordinator, customer-defined VNF instances can be easily migrated between heterogeneous middleboxes as the network environment changes. A resource allocation and scheduling algorithm dynamically assesses resource deployments as network flows and conditions are updated. We show that our deployment algorithm can successfully reallocate FPGA and microprocessor resources in a fraction of a second in response to changes in network flow capacity and network security threats including intrusion.
Food Webs and Ecosystems: Linking Species Interactions to the Carbon Cycle
Authors: Schmitz Oswald J. , Leroux Shawn J.
Published: August 2020

All species within ecosystems contribute to regulating carbon cycling because of their functional integration into food webs. Yet carbon modeling and accounting still assumes that only plants, microbes, and invertebrate decomposer species are relevant to the carbon cycle. Our multifaceted review develops a case for considering a wider range of species, especially herbivorous and carnivorous wild animals. Animal control over carbon cycling is shaped by the animals’ stoichiometric needs and functional traits in relation to the stoichiometry and functional traits of their resources. Quantitative synthesis reveals that failing to consider these mechanisms can lead to serious inaccuracies in the carbon budget. Newer carbon-cycle models that consider food-web structure based on organismal functional traits and stoichiometry can offer mechanistically informed predictions about the magnitudes of animal effects that will help guide new empirical research aimed at developing a coherent understanding of the interactions and importance of all species within food webs.
Parallelism in Flower Evolution and Development
Authors: Wessinger Carolyn A. , Hileman Lena C.
Published: August 2020

Flower evolution is characterized by widespread repetition, with adaptations to pollinator environment evolving in parallel. Recent studies have expanded our understanding of the developmental basis of adaptive floral novelties—petal fusion, bilateral symmetry, heterostyly, and floral dimensions. In this article, we describe patterns of trait evolution and review developmental genetic mechanisms underlying floral novelties. We discuss the diversity of mechanisms for parallel adaptation, the evidence for constraints on these mechanisms, and how constraints help explain observed macroevolutionary patterns. We describe parallel evolution resulting from similarities at multiple hierarchical levels—genetic, developmental, morphological, functional—which indicate general principles in floral evolution, including the central role of hormone signaling. An emerging pattern is mutational bias that may contribute to rapid patterns of parallel evolution, especially if the derived trait can result from simple degenerative mutations. We argue that such mutational bias may be less likely to govern the evolution of novelties patterned by complex developmental pathways.
The Evolution of Mutualistic Dependence
Authors: Chomicki Guillaume , Kiers E. Toby , Renner Susanne S.
Published: August 2020

While the importance of mutualisms across the tree of life is recognized, it is not understood why some organisms evolve high levels of dependence on mutualistic partnerships, while other species remain autonomous or retain or regain minimal dependence on partners. We identify four main pathways leading to the evolution of mutualistic dependence. Then, we evaluate current evidence for three predictions: ( a) Mutualisms with different levels of dependence have distinct stabilizing mechanisms against exploitation and cheating, ( b) less dependent mutualists will return to autonomy more often than those that are highly dependent, and ( c) obligate mutualisms should be less context dependent than facultative ones. Although we find evidence supporting all three predictions, we stress that mutualistic partners follow diverse paths toward—and away from—dependence. We also highlight the need to better examine asymmetry in partner dependence. Recognizing how variation in dependence influences the stability, breakdown, and context dependence of mutualisms generates new hypotheses regarding how and why the benefits of mutualistic partnerships differ over time and space.
Honey as a Functional Food for Apis mellifera
Authors: Berenbaum May R. , Calla Bernarda
Published: August 2020

Although nectar is consumed, primarily as a supplemental food, by a broad range of insects spanning at least five orders, it is processed and stored by only a small number of species, most of which are bees and wasps in the superfamily Apoidea. Within this group, Apis mellifera has evolved remarkable adaptations facilitating nectar processing and storage; in doing so, this species utilizes the end product, honey, for diverse functions with few if any equivalents in other phytophagous insects. Honey and its phytochemical constituents, some of which likely derive from propolis, have functional significance in protecting honey bees against microbial pathogens, toxins, and cold stress, as well as in regulating development and adult longevity. The distinctive properties of A. mellifera honey appear to have arisen in multiple ways, including genome modification; partnerships with microbial symbionts; and evolution of specialized behaviors, including foraging for substances other than nectar. That honey making by A. mellifera involves incorporation of exogenous material other than nectar, as well as endogenous products such as antimicrobial peptides and royal jelly, suggests that regarding honey as little more than a source of carbohydrates for bees is a concept in need of revision.
Chemical Contamination of Drinking Water in Resource-Constrained Settings: Global Prevalence and Piloted Mitigation Strategies
Authors: Amrose Susan E. , Cherukumilli Katya , Wright Natasha C.
Published: August 2020

Chemical contamination of drinking water (including salinity) puts more than one billion people at risk of adverse health effects globally. Resource-constrained communities are the most affected and face unique challenges that require innovative safe water solutions. This review focuses on arsenic, fluoride, nitrates, lead, chromium, total dissolved solids, emerging organic contaminants, and, to a lesser extent, manganese, cadmium, selenium, and uranium. It covers contaminant prevalence, major health effects, and treatment technologies or avoidance strategies that have been proven effective in realistic water matrices and conditions. The review covers the levelized costs of water for pilot- and full-scale systems most relevant to resource-constrained communities, with a focus on component costs, including the costs of power systems, lifting water, waste management, and labor. These costs are not universally reported, but can be significant. The findingsare analyzed and discussed in the context of providing sustainable safe water solutions in resource-constrained settings.
Overqualification at Work: A Review and Synthesis of the Literature
Authors: Erdogan Berrin , Bauer Talya N.
Published: August 2020

Both perceived and objective measures of employee overqualification can impact job attitudes, various workplace behaviors, and work relationships. Utilizing motivation and capability-based theoretical approaches, this review summarizes research regarding the antecedents (demographic influences, personality traits, relational influences, job characteristics) and outcomes (individual health and well-being, turnover intentions and turnover, job performance, organizational citizenship behaviors, interpersonal relationships, innovative behaviors, counterproductive work behaviors, and career success) of overqualification. In addition, we review work done to date regarding the moderators and mediators of these relationships. Finally, we offer future directions for research.
Development of New Tuberculosis Drugs: Translation to Regimen Composition for Drug-Sensitive and Multidrug-Resistant Tuberculosis
Authors: Ernest Jacqueline P. , Strydom Natasha , Wang Qianwen , Zhang Nan , Nuermberger Eric , Dartois Véronique , Savic Rada M.
Published: August 2020

Tuberculosis (TB) kills more people than any other infectious disease. Challenges for developing better treatments include the complex pathology due to within-host immune dynamics, interpatient variability in disease severity and drug pharmacokinetics-pharmacodynamics (PK-PD), and the growing emergence of resistance. Model-informed drug development using quantitative and translational pharmacology has become increasingly recognized as a method capable of drug prioritization and regimen optimization to efficiently progress compounds through TB drug development phases. In this review, we examine translational models and tools, including plasma PK scaling, site-of-disease lesion PK, host-immune and bacteria interplay, combination PK-PD models of multidrug regimens, resistance formation, and integration of data across nonclinical and clinical phases.We propose a workflow that integrates these tools with computational platforms to identify drug combinations that have the potential to accelerate sterilization, reduce relapse rates, and limit the emergence of resistance.
Energy Band Alignment of Few-Monolayer WS2 and WSe2 with SiO2 Using Internal Photoemission Spectroscopy
Authors: Delie Gilles , Litwin Peter M. , McDonnell Stephen J. , Chiappe Daniele , Houssa Michel , Afanas’ev Valeri V.
Published: August 2020

Internal photoemission spectroscopy was used to determine the valence band top energy position in few-monolayer WS2 and WSe2 films directly synthesized on top of the SiO2 insulator. It is found that in WS2 the valence band top edge lies systematically higher (by 0.4–0.7 eV) in energy than that in WSe2. This unexpected trend is seen for several synthesis methods suggesting it to be the intrinsic property of these W-based layered dichalcogenides. At the same time, a change in the WS2 synthesis method from metal sulfurization to chemical vapor deposition leads to a ≈0.3 eV barrier change indicating a non-negligible impact of interface charges or dipoles. The influence of synthesis chemistry on the WSe2/SiO2 interface barrier appears to be marginal at least for the selenization and molecular-beam epitaxy growth methods.
Oxytocin’s anti-inflammatory and proimmune functions in COVID-19: a transcriptomic signature-based approach
Authors: Imami Ali S. , O’Donovan Sinead M. , Creeden Justin F. , Wu Xiaojun , Eby Hunter , McCullumsmith Cheryl B. , Uvnäs-Moberg Kerstin , McCullumsmith Robert E. , Andari Elissar
Published: August 2020

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a worldwide pandemic, infecting over 16 million people worldwide with a significant mortality rate. However, there is no current Food and Drug Administration-approved drug that treats coronavirus disease 2019 (COVID-19). Damage to T lymphocytes along with the cytokine storm are important factors that lead to exacerbation of clinical cases. Here, we are proposing intravenous oxytocin (OXT) as a candidate for adjunctive therapy for COVID-19. OXT has anti-inflammatory and proimmune adaptive functions. Using the Library of Integrated Network-Based Cellular Signatures (LINCS), we used the transcriptomic signature for carbetocin, an OXT agonist, and compared it to gene knockdown signatures of inflammatory (such as interleukin IL-1β and IL-6) and proimmune markers (including T cell and macrophage cell markers like CD40 and ARG1). We found that carbetocin’s transcriptomic signature has a pattern of concordance with inflammation and immune marker knockdown signatures that are consistent with reduction of inflammation and promotion and sustaining of immune response. This suggests that carbetocin may have potent effects in modulating inflammation, attenuating T cell inhibition, and enhancing T cell activation. Our results also suggest that carbetocin is more effective at inducing immune cell responses than either lopinavir or hydroxychloroquine, both of which have been explored for the treatment of COVID-19.
A New Lifetime Exponential-X Family of Distributions with Applications to Reliability Data
Authors: Huo Xiaoyan , Khosa Saima K. , Ahmad Zubair , Almaspoor Zahra , Ilyas Muhammad , Aamir Muhammad
Published: August 2020

Modeling reliability data with nonmonotone hazards is a prominent research topic that is quite rich and still growing rapidly. Many studies have suggested introducing new families of distributions to modify the Weibull distribution to model the nonmonotone hazards. In the present study, we propose a new family of distributions called a new lifetime exponential-X family. A special submodel of the proposed family called a new lifetime exponential-Weibull distribution suitable for modeling reliability data with bathtub-shaped hazard rates is discussed. The maximum-likelihood estimators of the model parameters are obtained. A brief Monte Carlo simulation study is conducted to evaluate the performance of these estimators. For illustrative purposes, two real applications from reliability engineering with bathtub-shaped hazard functions are analyzed. The practical applications show that the proposed model provides better fits than the other nonnested models.
Parkinson’s Disease-Induced Zebrafish Models: Focussing on Oxidative Stress Implications and Sleep Processes
Authors: Robea Madalina-Andreea , Balmus Ioana-Miruna , Ciobica Alin , Strungaru Stefan , Plavan Gabriel , Gorgan Lucian Dragos , Savuca Alexandra , Nicoara Mircea
Published: August 2020

The complex yet not fully understood pathophysiology of Parkinson’s disease includes an important molecular component consisting of oxidative status changes, thus leading to oxidative stress occurrence. While no particular evidence has been reported that describes the relationship between oxidative stress and the molecular mechanisms behind Parkinson’s disease development, animal model studies has shown that oxidative stress induction could modulate Parkinson’s disease symptomatology. Despite the inability to perfectly replicate human disease in animals and despite that Parkinson’s disease has not been reported in any animal species, animal modeling is one of the most important tools in understanding the complex mechanisms of human disorders. In this way, this study is aimed at detailing this particular relationship and describing the molecular mechanisms underlying Parkinson’s disease in animal models, focusing on the potential advantages and disadvantages of zebrafish in this context. The information relevant to this topic was gathered using major scientific database research (PubMed, Google Scholar, Web of Science, and Scopus) based on related keywords and inclusion criteria. Thus, it was observed that oxidative stress possesses an important role in Parkinson’s disease as shown by numerous animal model studies, many of which are based on rodent experimental models. However, an emerging impact of the zebrafish model was observed in the research of Parkinson’s disease pathological mechanisms with regard to disease development factors and the cause-effect relationship between oxidative stress and comorbidities (such as depression, hyposmia, fatigue, sleep disturbances, and cognitive deficits) and also with regard to the pharmacological potential of antioxidant molecules in Parkinson’s disease treatment.
Elimination of the Impact Produced by DG Units on the Voltage Profile of Distribution Networks
Authors: Ouali Saad , Cherkaoui Abdeljabbar
Published: August 2020

In this paper, an alternative strategy for real-time control of active distribution network voltage is developed, not by controlling the bus voltage as in the various centralized, decentralized, and local approaches presented in literature but rather by only eliminating the impact produced by active and reactive power of distributed generation (DG) units on the voltage of all network nodes and keeping the traditional voltage control systems dealing with the same constraints of passive systems. In literature, voltage deterioration introduced by DGs has been reported as one of the main obstacles for the interconnection of large amounts of DG units to the existing networks. In this paper, the novel control strategy is based on a sensitivity formula developed to calculate the compensation needed for additional distributed flexible AC transmission system (D-FACTS) devices to push and pull the exact reactive power and to eliminate the impact produced by DGs on the network voltage profile. The criteria of the allocation of the var devices and the required network reinforcement are developed in this paper, considering all possible topology structures, and an innovative codification method is introduced to reduce the needed computation time and communication data to actualize the sensitivity coefficients and get the proposed control approach flexible with network topology reconfiguration. The risk of the conflict of the proposed control system with the traditional voltage equipment is reduced due to the fast capability of D-FACTS devices to regulate their reactive power in finer granularity. A case study of two meshed IEEE 15-bus feeders is introduced to compare the voltage behavior with and without the presence of DG units and to evaluate the total system losses. The proposed method could be used for the interconnection of the first generation units in emerging networks, which does not yet have an active voltage control strategy, as it could be used for DG units not able to be connected to existing centralized control systems and it could also be used as the principal voltage control strategy, with the extension for several neighboring units and the preservation of the traditional voltage control systems.