bluuebunny/crossref_metadata_2025 huggingface dataset:
Patient‐reported extremity symptoms after robot‐assisted laparoscopic cystectomy
Authors: Johansson Veronica Ramirez , von Vogelsang Ann‐Christin
Published: January 2019

Aims and objectives

To describe patient‐reported extremity symptoms after robot‐assisted laparoscopic cystectomy in patients with bladder cancer.

Background

Preventive activities for remaining patient safety due to correct positioning play an important part in perioperative nursing care.Extremity injuries are well‐known after prolonged surgery, especially in robot‐assisted urologic surgery in the steep Trendelenburg position. The risk of injury increases due to patient‐related and operative risk factors.

Methods

A quantitative prospective observational study was conducted. Patients were followed up with the QuickDASH (Disabilities in the Arm, Shoulder and Hand), Lower Extremity Functional Scale (LEFS) and a study‐specific questionnaire 7–10 days and monthly, up to six months after surgery in patients with extremity symptoms. The study adheres to STROBE (strengthening the reporting of observational studies in epidemiology) guidelines, see Supporting information File S1.

Results

Out of the 94 included participants, 46.8% (n = 44) experienced extremity symptoms 7–10 days after surgery. Pain, numbness and weakness were the most frequent symptoms. There was a discrepancy between the patients reported symptoms and the documentation in the patient records. Only 13.6% (n = 3) of the reported pain was documented, respectively 27.5% (n = 11) of other symptoms.

Conclusion

A large proportion of the patients report postoperative extremity symptoms after robot‐assisted laparoscopic cystectomy. Prevention of complications in the perioperative setting, are together with follow‐ups, important nursing activities for maintaining patient safety and may both prevent and detect postoperative extremity symptoms and injuries.

Relevance to clinical practice

This study reveals the need of accurate documentation regarding extremity symptoms in digital patient records, as well as continuous follow‐ups during the hospital stay and after hospital discharge to enable detection of treatable extremity injuries. The result of this study also indicates the importance of nursing activities such as evidence‐based positioning guidelines in the operating theatre for optimal positioning.
The Effect of the Application Sequence of Casein Phosphopeptide‐Amorphous Calcium Phosphate Paste on the Shear Bond Strength of Etch‐and‐Rinse Resin Cements to Dentin
Authors: Doozandeh Maryam , Shafiei Fereshteh , Ghasempoor Pezhman , Dashti Mohammad Hossein
Published: January 2019

Purpose

To evaluate the effect of the application sequence of casein phosphopeptide‐amorphous calcium phosphate (CPP‐ACP) paste (MI paste) on shear bond strength (SBS) of 2 etch‐and‐rinse resin cements to dentin.

Materials and Methods

Sixty extracted human maxillary premolars were cut to expose the mid‐coronal dentin surfaces. The teeth were randomly divided into 6 groups (n = 10), based on the resin cement used and CPP‐ACP application. In groups 1‐3, Excite DSC/Variolink II and in groups 2‐4, One‐Step Plus/Duolink was bonded to dentin. There were 3 groups for each cement as follows: with no treatment as a control; 3‐minute application of CPP‐ACP before acid etching (CPP‐ACP/Etching); 3‐minute application of CPP‐ACP after acid etching (Etching/CPP‐ACP). After storage in distilled water at 37°C for 24 hours, SBS test was performed. Data were analyzed with 2‐way ANOVA and post‐hoc Tukey test (α = 0.05).

Results

CPP‐ACP application on the dentin before and after acid etching significantly decreased the SBS of OS/Duolink (13.60 and 14.71 MPa, respectively vs. control; 21.21 MPa, p < 0.001); however, it did not influence the SBS of Excite DSC/Variolink II (25.14 MPa) before acid etching (27.37 MPa) or after acid etching (26.41 MPa, p > 0.388). The application sequence of CPP‐ACP did not influence the SBS of etch‐and‐rinse resin cements evaluated.

Conclusion

CPP‐ACP applications may lower the SBS in some etch‐and‐rinse resin cements, and timing of applications makes no difference.
Clinical description of Corynebacterium urealyticum urinary tract infections in 11 dogs and 10 cats
Authors: Maurey C. , Boulouis H.‐J. , Canonne‐Guibert M. , Benchekroun G.
Published: January 2019

Objectives

To examine the clinical signs, laboratory findings, possible predisposing factors, antimicrobial sensitivity and outcomes of dogs and cats diagnosed with urinary tract infection caused by Corynebacterium urealyticum.

Materials and Methods

Retrospective, observational study of dogs and cats that were diagnosed with urinary tract infection caused by C. urealyticum.

Results

This report concerns a total of 11 dogs and 10 cats. All cats had a history of urethral catheterisation, and six cats had undergone urological surgery before diagnosis of this specific infection. Dogs had history of neurogenic urinary incontinence (n=5), urethral catheterisation (n=4), urological surgery (n=4), lower urinary tract disease (n=2) or prostatic disease (n=1). In seven animals, previous urine culture was negative. Median urine pH was 8.6 (interquartile range 7.5 to 9), and 19 animals had pyuria and struvite crystalluria. Encrusted cystitis was diagnosed by abdominal ultrasound in nine animals. All but one isolate were resistant to at least three antimicrobial classes. Thirteen isolates were sensitive to tetracyclines. There was bacterial and clinical resolution of the infection in nine dogs and seven cats. Two animals died from sepsis and two cats were euthanased because of clinical deterioration.

Clinical Significance

Urinary tract infection caused by C. urealyticum should be suspected in animals with pre‐existing urinary disorders, especially if urine is alkaline and there is struvite crystalluria, negative routine urine culture and encrusted cystitis.
Footprints of adaptive evolution revealed by whole Z chromosomes haplotypes in flycatchers
Authors: Nadachowska‐Brzyska Krystyna , Burri Reto , Ellegren Hans
Published: January 2019

Detecting positive selection using genomic data is critical to understanding the role of adaptive evolution. Of particular interest in this context is sex chromosomes since they are thought to play a special role in local adaptation and speciation. We sought to circumvent the challenges associated with statistical phasing when using haplotype‐based statistics in sweep scans by benefitting from that whole chromosome haplotypes of the sex chromosomes can be obtained by resequencing of individuals of the hemizygous sex. We analyzed whole Z chromosome haplotypes from 100 females from several populations of four black and white flycatcher species (in birds, females are ZW and males ZZ). Based on integrated haplotype score (iHS) and number of segregating sites by length (nSL) statistics, we found strong and frequent haplotype structure in several regions of the Z chromosome in each species. Most of these sweep signals were population‐specific, with essentially no evidence for regions under selection shared among species. Some completed sweeps were revealed by the cross‐population extended haplotype homozygosity (XP‐EHH) statistic. Importantly, by using statistically phased Z chromosome data from resequencing of males, we failed to recover the signals of selection detected in analyses based on whole chromosome haplotypes from females; instead, what likely represent false signals of selection were frequently seen. This highlights the power issues in statistical phasing and cautions against conclusions from selection scans using such data. The detection of frequent selective sweeps on the avian Z chromosome supports a large role of sex chromosomes in adaptive evolution.
Attraction of the sandfly Lutzomyia longipalpis to possible biomarker compounds from dogs infected with Leishmania infantum
Authors: Magalhães‐Junior J. T. , Oliva‐Filho A. De A. , Novais H. O. , Mesquita P. R. R. , M. Rodrigues F. , Pinto M. C. , Barrouin‐Melo S. M.
Published: January 2019

Lutzomyia longipalpis (Diptera: Psychodidae) is the primary vector of Leishmania infantum (Kinetoplastida: Trypanosomatidae) in the Americas. Studies have been carried out to identify new alternatives for monitoring and controlling this sandfly species, particularly with the use of chemical baits. The attractiveness of odours emitted by foxes and alcohols found in some plants has already been demonstrated in laboratory tests with Lu. longipalpis. However, no studies have evaluated the responses of these insects to volatile organic compounds (VOCs) emitted by dogs. The present study was carried out to investigate the effects on Lu. longipalpis of individual and blends of VOCs identified in hair from dogs infected with L. infantum. Effects in male and female Lu. longipalpis were assessed using wind tunnel methodology. Individual compounds including octanal, nonanal, decanal and heptadecane showed capacity for activating and/or attracting male Lu. longipalpis. Only decanal and nonanal showed effects on females. The combination of octanal, decanal and heptadecane increased activation and attraction behaviour in male sandflies, as did the blend of octanal and decanal. These findings indicate that VOCs emitted by dogs may be an interesting source of new attractants of sandflies.
Overweight and obesity among adults in the Gulf States: A systematic literature review of correlates of weight, weight‐related behaviours, and interventions
Authors: Balhareth Abdulaziz , Meertens Ree , Kremers Stef , Sleddens Ester
Published: January 2019

Obesity has increased to an epidemic level in the Gulf States. This systematic review is the first to explore the scientific evidence on correlates and interventions for overweight (body mass index [BMI] ≥ 25) or weight‐related behaviours in the region. A systematic search of peer‐reviewed articles was conducted using PubMed and PsycINFO. Ninety‐one studies were eligible for this review including 84 correlate studies and seven intervention studies. Correlate studies of overweight focused on sociodemographic factors, physical activity, and dietary habits. Low physical activity, sedentary behaviour, and unhealthy dietary habits were associated with overweight. The most‐reported sociodemographic correlates of overweight were increased age, being married, low education, urban residence, and unemployment. Correlate studies of physical activity and dietary behaviours mostly focused on sociodemographic variables. Being female and increased age (the latter less consistently) were associated with low physical activity. Interventions were very heterogeneous with respect to the target group, intensity, and behavioural strategies used. The effectiveness of interventions was difficult to evaluate because of the chosen study design or outcome measure, the small sample size, or high attrition rate. Few studies have investigated sociocognitive and environmental determinants of weight‐related behaviours. Such information is crucial to developing health promotion initiatives that target those weight‐related behaviours.
TCP transcription factors interact with ZED1‐related kinases as components of the temperature‐regulated immunity
Authors: Wang Zhicai , Cui Dayong , Liu Cheng , Zhao Jingbo , Liu Jing , Liu Na , Tang Dingzhong , Hu Yuxin
Published: January 2019

The elevation of ambient temperature generally inhibits plant immunity, but the molecular regulations of immunity by ambient temperature in plants are largely elusive. We previously reported that the Arabidopsis HOPZ‐ETI‐DEFICIENT 1 (ZED1)‐related kinases (ZRKs) mediate the temperature‐sensitive immunity by inhibiting the transcription of SUPPRESSOR OF NPR1‐1, CONSTITUTIVE 1 (SNC1). Here, we further demonstrate that the nucleus‐localized ZED1 and ZRKs facilitate such inhibitory role in associating with the TEOSINTE BRANCHED1, CYCLOIDEA AND PROLIFERATING CELL FACTOR (TCP) transcription factors. We show that some of TCP members could physically interact with ZRKs and are induced by elevated temperature. Disruption of TCPs leads to a mild autoimmune phenotype, whereas overexpression of the TCP15 could suppress the autoimmunity activated by the overexpressed SNC1 in the snc1‐2. These findings demonstrate that the TCP transcription factors associate with nuclear ZRK as components of the temperature‐regulated immunity, which discloses a possible molecular mechanism underlying the regulation of immunity by ambient temperature in plants.
Injustice and the right to punish
Authors: Duus‐Otterström Göran , Kelly Erin I.
Published: January 2019

Injustice can undermine the standing states have to blame criminal offenders, and this raises a difficulty for a range of punishment theories that depend on a state's moral authority. When a state lacks the moral authority that flows from political legitimacy, its right to punish criminal lawbreakers cannot depend on a systematic claim about the legitimacy of the law. Instead, an unjust state is permitted to punish only criminal acts whose wrongness is established directly by morality, and only when criminal guilt is established through legal procedures that meet minimal standards of fairness. These restrictions narrow the proper scope of criminal law and invalidate popular rationales for punishment that construe punishment as blame.
A Time‐Based Policy for Empty Container Management by Consignees
Authors: Legros Benjamin , Bouchery Yann , Fransoo Jan
Published: January 2019

Despite the many advantages of containerization for goods transportation, the management of empty containers is a major disadvantage, driving costly repositioning operations. We investigate the potential for consignees to manage an inventory of empty containers at their location so as to enable direct reuse of these containers by consignors located in the surroundings. One difficulty is that the detention fees imposed by shipping companies under merchant haulage are nonlinear. Moreover, cleaning and related activities might be necessary if the consignee keeps some empties. These difficulties incentivize consignees to immediately return containers to the sea terminal. Contrary to this practice, we show that managing containers via time‐based threshold policies can save costs. Without cleaning costs, we prove that a time‐based policy with a timeout return time is optimal. We next develop a policy improvement approach to include the cleaning costs in the analysis. This results in a two‐thresholds time‐based policy where the two time thresholds control the admission into and rejection out of the inventory. We next analyze the impact of this proactive management on the level of direct container reuse. This practice enables a high level of direct reuse. It also reduces container repositioning costs. Yet, the incentive to implement our policy varies a lot from one setting to another. In particular, low cleaning costs or high repositioning costs lead to significant costs improvement when implementing our policy. Finally, we further explore if the incentive could be made stronger by modifying the structure and/or purpose of the detention costs.
The interplay of friends and parents in adolescents’ daily lives: Towards a dynamic view of social support
Authors: Schacter Hannah L. , Margolin Gayla
Published: January 2019

This daily diary study investigated the interplay of perceived friend and parent support in adolescents’ everyday lives. Specifically, we tested the interactive effects of friend and parent support on adolescent well‐being at both the intra‐ and inter‐individual level. A diverse sample of 119 adolescents (Mage = 15.36) completed diary reports for 2 weeks. Multivariate multilevel models demonstrated that on days adolescents felt more supported by their friends or parents, they experienced increases in their happiness and social connectedness. Additionally, parent support emerged as a protective factor for youth lacking friend support, although patterns differed at the intra‐ vs. inter‐individual level. The findings underscore the dynamic nature of social support in adolescents’ daily lives and highlight the interactive roles of friends and parents in promoting youth well‐being.
Epidemiología y caracterización general de los tumores cerebrales primarios en el adulto
Authors: Ocampo Navia Maria Isabel , Gómez Vega Juan Carlos , Feo Lee Oscar Hernando
Published: January 2019

Los tumores primarios del sistema nervioso representaron aproximadamente el 1,4 % de los nuevos diagnósticos de cáncer en 2015 y causan el 2,6 % de las muertes por cáncer. Estos tienen una mayor implicación clínica en la población infantil y en adultos jóvenes; y su incidencia disminuye con la edad. Los tumores más frecuentes en los adultos incluyen meningiomas, gliomas y tumores pituitarios. En este artículo se hace una revisión actualizada sobre la epidemiología de los tumores primarios del sistema nervioso, así como las principales características y actualizaciones en el manejo de los tumores más prevalentes en la población adulta.
Enfoque diagnóstico del paciente con rubor facial transitorio en atención primaria
Authors: Vivas Prieto José Manuel , Caballero Vera Sandra Virginia , Echeverry Ramírez Mateo
Published: January 2019

El rubor facial transitorio se define como una sensación de calor, acompañada de enrojecimiento de la piel, causada por una respuesta vasomotora con el resultante incremento en el flujo sanguíneo regional, debido a la acción directa de diferentes mediadores liberados por los nervios. Los cuadros pueden ser episódicos o constantes y se relacionan con respuestas fisiológicas y con patologías de origen benigno y maligno. El objetivo de la revisión es realizar un abordaje racional de esta condición en el escenario de atención primaria, con el fin de llegar a un diagnóstico precoz y completo, abordando los principales diagnósticos diferenciales asociados con esta condición.
Modeling Crane-Induced Ship Motion Using the Moving Frame Method
Authors: Alexander Jacobsen Jardim Paulo , Tore Rein Jan , Haveland Øystein , Rykkje Thorstein R. , Impelluso Thomas J.
Published: January 2019

A decline in oil-related revenues challenges Norway to focus on new types of offshore installations. Often, ship-mounted crane systems transfer cargo or crew onto offshore installations such as floating windmills. This project analyzes the motion of a ship induced by an onboard crane in operation using a new theoretical approach to dynamics: the moving frame method (MFM). The MFM draws upon Lie group theory and Cartan's moving frames. This, together with a compact notation from geometrical physics, makes it possible to extract the equations of motion, expeditiously. While others have applied aspects of these mathematical tools, the notation presented here brings these methods together; it is accessible, programmable, and simple. In the MFM, the notation for multibody dynamics and single body dynamics is the same; for two-dimensional (2D) and three-dimensional (3D), the same. Most importantly, this paper presents a restricted variation of the angular velocity to use in Hamilton's principle. This work accounts for the masses and geometry of all components, interactive motor couples and prepares for buoyancy forces and added mass. This research solves the equations numerically using a relatively simple numerical integration scheme. Then, the Cayley–Hamilton theorem and Rodriguez's formula reconstruct the rotation matrix for the ship. Furthermore, this work displays the rotating ship in 3D, viewable on mobile devices. This paper presents the results qualitatively as a 3D simulation. This research demonstrates that the MFM is suitable for the analysis of “smart ships,” as the next step in this work.
Deceleration Performance and Parameter Influence Analysis of the Control Rod Hydraulic Deceleration Device for Control Rod Hydraulic Drive System
Authors: Benke Qin , Leishi Li , Hanliang Bo
Published: January 2019

Control rod hydraulic drive system (CRHDS), which is invented by INET, Tsinghua University, is a new type of internal control rod drive technology. Control rod hydraulic deceleration device (CRHDD), which consists of the plug, the hydraulic deceleration cylinder, etc., is one of the main components of the CRHDS. The CRHDD performs the rod dropping deceleration function through the interworking of the plug and the deceleration cylinder, which is filled with water, and reduces the rod dropping peak acceleration and the impact force acting upon the control rod to prevent the control rod cruciform blade from being deformed or damaged. The working mechanism of the CRHDD is presented and analyzed. The theoretical model of the control rod dropping process, which is based upon force analysis of the control rod during scram process, three-dimensional flow field analysis, and flow resistance calculation of the hydraulic deceleration cylinder, the kinematics and dynamics analysis of the control rod, is built whose results are compared and validated by the CRHDS scram test results. Then the model is used to analyze the influence of the key parameters, including the fuel case gap, the plug design clearance, the working temperature, etc. on the CRHDD working performance. The research results can give guidance for the design and optimization of the CRHDD.
Density functional theory study on the fluorination reactions of silicon and silicon dioxide surfaces using different fluorine-containing molecules
Authors: Chowdhury Tanzia , Hidayat Romel , Mayangsari Tirta Rona , Gu Jiyeon , Kim Hye-Lee , Jung Jongwan , Lee Won-Jun
Published: January 2019

The authors report the reaction mechanism of the initial fluorination process on the H-terminated Si and the OH-terminated SiO2 surfaces with HF, CF4, CHF3, NF3, and ClF3. The reaction process in which a fluorine atom in a gas molecule dissociates Si–OH or Si–H surface group to form Si-F bonds is modeled and simulated by density functional theory calculations using a slab surface model. The physisorption and the chemisorption of all gases on the SiO2 surface are exothermic. However, the activation energy for chemisorption varies depending on the molecule. HF demonstrates the lowest activation energy of 0.18 eV, while CF4 has the highest value of 6.32 eV. In the case of the Si surface, the physisorption and the chemisorption of all gases are also exothermic reactions. ClF3 and NF3 exhibit near zero activation energies of 0.02 and 0.04 eV, whereas CHF3 has the highest value of 2.33 eV. Their calculation results explain the mechanism of the vapor phase etching of Si and SiO2.
Electromagnetic field visualization in virtual reality
Authors: Franklin J. , Ryder Andrew
Published: January 2019

We developed two virtual reality demonstrations for electromagnetism. For statics, we use spherical building blocks and superposition to calculate the electric field of a user-generated configuration of charge. The electric field information is displayed on a three-dimensional grid using vector arrows. A second demonstration displays field information for electromagnetic fields generated by a particle moving along a user-generated path (at arbitrary speed). We used the Unity game creation engine to efficiently develop the demonstrations, and tested them on an HTC Vive VR headset with handheld controllers.
Manual timing in physics experiments: Error and uncertainty
Authors: Faux David A. , Godolphin Janet
Published: January 2019

Manual digital timing devices such as stopwatches are ubiquitous in the education sector for experimental work where automated electronic timing is unavailable or impractical. The disadvantage of manual timing is that the experimenter introduces an additional systematic error and random uncertainty to a measurement that hitherto could only be approximated and which masks useful information on uncertainty due to variations in the physical conditions of the experiment. A model for the reaction time of a timekeeper using a stopwatch for a single anticipated visual stimulus of the type encountered in physics experiments is obtained from a set of 4304 reaction times from timekeepers at swimming competitions. The reaction time is found to be well modelled by the normal distribution N(ϵ, σ2) = N(0.11, 0.072) in units of seconds where ϵ and σ2 are the systematic error and variance for a single time measurement. Consistency between timekeepers is shown to be very good. The reaction time for a stopwatch-operated start and stop experiment can therefore be modelled by N(0, 0.102), assuming that the average reaction time is the same in both cases. This makes a significant contribution to the uncertainty of most manually timed measurements. This timing uncertainty can be subtracted out of the variation observed in repeat measurements in the real experiment to reveal the uncertainty solely associated with fluctuations in the physical conditions of the experiment.
The mysterious spinning cylinder—Rigid-body motion that is full of surprises
Authors: Jackson David P. , Huddy Julia , Baldoni Adam , Boyes William
Published: January 2019

We explore the steady-state rotational motion of a cylinder on a flat horizontal surface from a pedagogical perspective. We show that the cylinder's inclination angle depends on its rotational velocity in a surprisingly subtle manner, including both stable and unstable solutions as well as a forbidden region with no (real) solutions. Moreover, the cylinder's behavior undergoes a qualitative change as the aspect ratio decreases below a critical value. Using a high-speed video, we measure the inclination angle as a function of rotation speed and demonstrate good agreement with the theoretical predictions. All aspects of the analysis are well within the capabilities of undergraduate students, making this an ideal system to explore in courses or as an independent project.
First systematic assessment of dental growth and development in an archaic hominin (genus,
Homo
) from East Asia
Authors: Xing Song , Tafforeau Paul , O’Hara Mackie , Modesto-Mata Mario , Martín-Francés Laura , Martinón-Torres María , Zhang Limin , Schepartz Lynne A. , de Castro José María Bermúdez , Guatelli-Steinberg Debbie
Published: January 2019

An archaic
Homo
juvenile from the East Asian Middle-Late Pleistocene transition has surprisingly modern dental development.
Acclimation of methane emissions from rice paddy fields to straw addition
Authors: Jiang Yu , Qian Haoyu , Huang Shan , Zhang Xingyue , Wang Ling , Zhang Li , Shen Mingxing , Xiao Xiaoping , Chen Fu , Zhang Hailin , Lu Changying , Li Chao , Zhang Jun , Deng Aixing , van Groenigen Kees Jan , Zhang Weijian
Published: January 2019

The effects of straw incorporation on CH
4
emissions from rice fields decrease over time, due to increased CH
4
consumption in soil.
Learning agile and dynamic motor skills for legged robots
Authors: Hwangbo Jemin , Lee Joonho , Dosovitskiy Alexey , Bellicoso Dario , Tsounis Vassilios , Koltun Vladlen , Hutter Marco
Published: January 2019

A method for learning agile control policies uses simulated data to enable precise, efficient movements in a complex physical robot.
An engineered
E. coli
Nissle improves hyperammonemia and survival in mice and shows dose-dependent exposure in healthy humans
Authors: Kurtz Caroline B. , Millet Yves A. , Puurunen Marja K. , Perreault Mylène , Charbonneau Mark R. , Isabella Vincent M. , Kotula Jonathan W. , Antipov Eugene , Dagon Yossi , Denney William S. , Wagner David A. , West Kip A. , Degar Andrew J. , Brennan Aoife M. , Miller Paul F.
Published: January 2019

An engineered
E. coli
strain lowers blood ammonia, improves survival in models of hyperammonemia, and demonstrates safety in healthy volunteers.
BH3 mimetics: Weapons of cancer cell destruction
Authors: Chonghaile Tríona Ní
Published: January 2019

Specific MCL-1 inhibitor kills multiple myeloma and acute myeloid leukemia cells.
A Counterselectable Sucrose Sensitivity Marker Permits Efficient and Flexible Mutagenesis in
Streptococcus agalactiae
Authors: Hooven Thomas A. , Bonakdar Maryam , Chamby Anna B. , Ratner Adam J.
Published: January 2019

The ability to generate chromosomal mutations is fundamental to microbiology. Historically, however, GBS pathogenesis research has been made challenging by the relative genetic intractability of the organism. Generating a single knockout in GBS using traditional techniques can take many months, with highly variable success rates. Furthermore, traditional methods do not offer a straightforward way to generate single-base-pair polymorphisms or other subtle changes, especially to noncoding regions of the chromosome. We have developed a new sucrose counterselection-based method that permits rapid, efficient, and flexible GBS mutagenesis. Our technique requires no additional equipment beyond what is needed for traditional approaches. We believe that it will catalyze rapid advances in GBS genetics research by significantly easing the path to generating mutants.
The
Porphyromonas gingivalis
Hybrid Cluster Protein Hcp Is Required for Growth with Nitrite and Survival with Host Cells
Authors: Belvin B. Ross , Gui Qin , Hutcherson Justin A. , Lewis Janina P.
Published: January 2019

Although the periodontal pathogen
Porphyromonas gingivalis
must withstand high levels of nitrosative stress while in the oral cavity, the mechanisms of nitrosative stress defense are not well understood in this organism. Previously we showed that the transcriptional regulator HcpR plays a significant role in defense, and here we further defined its regulon.
The Polar Region of the HIV-1 Envelope Protein Determines Viral Fusion and Infectivity by Stabilizing the gp120-gp41 Association
Authors: Lu Wuxun , Chen Shuliang , Yu Jingyou , Behrens Ryan , Wiggins Joshua , Sherer Nathan , Liu Shan-Lu , Xiong Yong , Xiang Shi-Hua , Wu Li
Published: January 2019

Although extensive studies of the transmembrane unit (gp41) of HIV-1 Env have led to a fusion inhibitor clinically used to block viral entry, the functions of different domains of gp41 in HIV-1 fusion and infectivity are not fully elucidated. The polar region (PR) of gp41 has been proposed to participate in HIV-1 membrane fusion in biochemical analyses, but its role in viral entry and infectivity remain unclear. In our effort to characterize three nucleotide mutations of an HIV-1 RNA element that partially overlaps the PR coding sequence, we identified a novel function of the PR that determines viral fusion and infectivity. We further demonstrated the structural and functional impact of six PR mutations on HIV-1 Env stability, viral fusion, and infectivity. Our findings reveal the previously unappreciated function of the PR and the underlying mechanisms, highlighting the important role of the PR in regulating HIV-1 fusion and infectivity.
Effects of high-intensity interval training frequency on perceptual responses and future physical activity participation
Authors: Stavrinou Pinelopi S. , Bogdanis Gregory C. , Giannaki Christoforos D. , Terzis Gerasimos , Hadjicharalambous Marios
Published: January 2019

The effectiveness of high-intensity interval training (HIIT) in inducing positive physiological adaptations is well documented. However, its impact on perceptual responses and on future physical activity (PA) engagement is less evaluated. The present study aimed to examine the effects of HIIT frequency on perceptual responses, health-related quality of life (HRQOL), and its influence in future PA participation. Thirty-five inactive adults were randomly assigned to a control (CON) and to 2 training groups that performed HIIT (10 × 60 s cycling, ∼83% peak power output) for 2 (HIIT-2) or 3 (HIIT-3) times per week for 8 weeks. Following the HIIT intervention, exercise enjoyment, HRQOL, and the intention to implement HIIT in the future were evaluated. Eight weeks after cessation of training, follow-up evaluations of HRQOL and PA were performed. Following the intervention, both training frequencies induced high levels of enjoyment (HIIT-2: 6.0 ± 1.1, HIIT-3: 6.0 ± 1.1, scale 1–7), improved HRQOL (HIIT-2: p = 0.040; HIIT-3: p = 0.024), and reported intention to implement HIIT in the future (HIIT-3: 100%, HIIT-2: 93% of participants). At follow-up, HIIT-3 participants reported higher completion of HIIT compared with HIIT-2 and CON (p < 0.05). Both training groups sustained improved HRQOL and increased vigorous and total PA (p < 0.05). This study showed that performing HIIT either 2 or 3 times per week is an enjoyable exercise modality that promotes a sustainable increase in habitual PA levels and improves HRQOL. Moreover, the higher training frequency resulted in greater HIIT completion in the 8-week period following the cessation of training.
Delay-induced synchronization transition in a small-world neuronal network of FitzHugh–Nagumo neurons subjected to sine-Wiener bounded noise
Authors: Yao Yuangen , Yi Ming , Hou Dejia
Published: January 2019

Noise and delay are ubiquitous in brain and they have significant effects on neuronal network synchronization and even brain functions. Based on a small-world neuronal network of delayed FitzHugh–Nagumo (FHN) neurons subjected to sine-Wiener (SW) bounded noise, the effects of delay and SW noise on synchronization and synchronization transition are numerically investigated by calculating a synchronization measure R and plotting spatiotemporal patterns. The phenomenon of delay-induced synchronization transition is observed as delay [Formula: see text] is increased. And large self-correlation time and strength of SW noise can increase the number of delay-induced synchronization transition. In addition, delay-induced synchronization transition is robust against the change of topology structure of neuronal network and this phenomenon becomes much easier to see for small nearest neighbors k in the small-world network. Since synchronization transition may imply functional switch, our results may have important implications, and inspire future studies.
Steady-state Approximations
Authors: Dai Jim
Published: January 2019

Diffusion models and mean-field models have been used to approximate many stochastic dynamical systems. A functional strong law of large numbers or a functional central limit theorem justifies such an approximation. Such a result, however, does not justify the convergence of the equilibria of pre-limit systems to the equilibrium of a limit system. In this talk, I will touch on three recently developed methods for justifying equilibrium convergence in the setting of bandwidth sharing networks and multiclass queueing networks, with a focus on moment generating function method and the state-space-collapse. Based on joint works with Anton Braverman, Chang Cao, Masakiyo Miyazawa, and Xiangyu Zhang.
Delay Scaling in Many-Sources Wireless Networks without Queue State Information
Authors: Borst Sem , Zubeldia Martin
Published: January 2019

We examine a canonical scenario where several wireless data sources generate sporadic delay-sensitive messages that need to be transmitted to a common access point. The access point operates in a time-slotted fashion, and can instruct the various sources in each slot with what probability to transmit a message, if they have any. When several sources transmit simultaneously, the access point can detect a collision, but is unable to infer the identities of the sources involved. While the access point can use the channel activity observations to obtain estimates of the queue states at the various sources, it does not have any explicit queue length information otherwise. We explore the achievable delay performance in a regime where the number of sources n grows large while the relative load remains fixed. We establish that, under any medium access algorithm without queue state information, the average delay must be at least of the order of n slots when the load exceeds some threshold lambda* < 1. This demonstrates that bounded delay can only be achieved if a positive fraction of the system capacity is sacrificed. Furthermore, we introduce a scalable Two-Phase algorithm which achieves a delay upper bounded uniformly in n when the load is below e -1 , and a delay of the order of n slots when the load is between e -1 and 1. Additionally, this algorithm provides robustness against correlated source activity.
A Quantitative Evaluation of Contemporary GPU Simulation Methodology
Authors: Jain Akshay , Khairy Mahmoud , Rogers Timothy G.
Published: January 2019

Contemporary Graphics Processing Units (GPUs) are used to accelerate highly parallel compute workloads. For the last decade, researchers in academia and industry have used cycle-level GPU architecture simulators to evaluate future designs. This paper performs an in-depth analysis of commonly accepted GPU simulation methodology, examining the effect both the workload and the choice of instruction set architecture have on the accuracy of a widely-used simulation infrastructure, GPGPU-Sim. We analyze numerous aspects of the architecture, validating the simulation results against real hardware. Based on a characterized set of over 1700 GPU kernels, we demonstrate that while the relative accuracy of compute-intensive workloads is high, inaccuracies in modeling the memory system result in much higher error when memory performance is critical. We then perform a case study using a recently proposed GPU architecture modification, demonstrating that the cross-product of workload characteristics and instruction set architecture choice can have an affect on the predicted efficacy of the technique.
Asymptotically Optimal Load Balancing Topologies
Authors: Mukherjee Debankur , Borst Sem , van Leeuwaarden Johan S. H.
Published: January 2019

We consider a system of N ~servers inter-connected by some underlying graph topology~G N . Tasks with unit-mean exponential processing times arrive at the various servers as independent Poisson processes of rate lambda. Each incoming task is irrevocably assigned to whichever server has the smallest number of tasks among the one where it appears and its neighbors in G N . The above model arises in the context of load balancing in large-scale cloud networks and data centers, and has been extensively investigated in the case G N is a clique. Since the servers are exchangeable in that case, mean-field limits apply, and in particular it has been proved that for any lambda < 1, the fraction of servers with two or more tasks vanishes in the limit as N -> ınfty. For an arbitrary graph G N , mean-field techniques break down, complicating the analysis, and the queue length process tends to be worse than for a clique. Accordingly, a graph G N is said to be N -optimal or ∞N-optimal when the queue length process on G N is equivalent to that on a clique on an N -scale or ∞N-scale, respectively. We prove that if G N is an Erdos-Rényi random graph with average degree d(N), then with high probability it is N -optimal and ∞N-optimal if d(N) -> ınfty$ and d(N) / (∞N łog(N)) -> ınfty as N -> ınfty, respectively. This demonstrates that optimality can be maintained at N -scale and ∞N-scale while reducing the number of connections by nearly a factor N and ∞N/ łog(N) compared to a clique, provided the topology is suitably random. It is further shown that if G N contains Θ(N) bounded-degree nodes, then it cannot be N -optimal. In addition, we establish that an arbitrary graph G N is N -optimal when its minimum degree is N - o(N), and may not be N -optimal even when its minimum degree is c N + o(N) for any 0 < c < 1/2. Simulation experiments are conducted for various scenarios to corroborate the asymptotic results.
ACM Sigmetrics Performance Evaluation Review
Authors: Hegde Nidhi
Published: January 2019

This editorial announces a new series on diversity in the ACM Sigmetrics Performance Evaluation Review (PER). In several upcoming and future issues we will feature invited articles on diversity from authors in the performance evaluation community, but also from the larger Computing Science (CS) community. The articles will touch various aspects in CS including K-12 and post-secondary education, graduate studies, academic recruitment, industry perspectives, harassment issues, and gender, ethnicity, and racial bias.
SRPT for Multiserver Systems
Authors: Grosof Isaac , Scully Ziv , Harchol-Balter Mor
Published: January 2019

The Shortest Remaining Processing Time (SRPT) scheduling policy and variants thereof have been deployed in many computer systems, including web servers [5], networks [9], databases [3] and operating systems [1]. SRPT has also long been a topic of fascination for queueing theorists due to its optimality properties. In 1966, the mean response time for SRPT was first derived [11], and in 1968 SRPT was shown to minimize mean response time in both a stochastic sense and a worst-case sense [10]. However, these beautiful optimality results and the analysis of SRPT are only known for single-server systems. Almost nothing is known about SRPT in multiserver systems, such as the M/G/k, even for the case of just k = 2 servers.
Minimal-variance distributed scheduling under strict demands and deadlines
Authors: Nakahira Yorie , Ferragut Andres , Wierman Adam
Published: January 2019

Many modern schedulers can dynamically adjust their service capacity to match the incoming workload. At the same time, however, variability in service capacity often incurs operational and infrastructure costs. In this abstract, we characterize an optimal distributed algorithm that minimizes service capacity variability when scheduling jobs with deadlines. Specifically, we show that Exact Scheduling minimizes service capacity variance subject to strict demand and deadline requirements under stationary Poisson arrivals. Moreover, we show how close the performance of the optimal distributed algorithm is to that of the optimal centralized algorithm by deriving a competitive-ratio-like bound.
Fair Allocation of Heterogeneous and InterchangeableResources
Authors: Sun Xiao , Le Tan N. , Chowdhury Mosharaf , Liu Zhenhua
Published: January 2019

Motivated by the proliferation of heterogeneous processors such as multi-core CPUs, GPUs, TPUs, and other accelerators for machine learning, we formulate a novel multiinterchangeable resource allocation (MIRA) problem where some resources are interchangeable. The challenge is how to allocate interchangeable resources to users in a sharing system while maintaining desirable properties such as sharing incentive, Pareto efficiency, and envy-freeness. In this paper, we first show that existing algorithms, including the Dominant Resource Fairness used in production systems, fail to provide these properties for interchangeable resources. Then we characterize the tradeoff between performance and strategyproofness, and design the Budget-based (BUD) algorithm, which preserves Pareto efficiency, sharing incentive and envyfreeness while providing better performance over currently used algorithms.
A queueing-theoretic model for resource allocation in one-dimensional distributed analytics network?
Authors: Panigrahy Nitish K. , Basu Prithwish , Towsley Don , Swami Ananthram , Chan Kevin S. , Leung Kin K.
Published: January 2019

We consider the problem of allocating requesters of analytic tasks to resources on servers. We assume both requesters and servers are placed in a one dimensional line: [0,1) according to two Poisson processes with each server having finite capacity. Requesters communicate with servers under a noninterference wireless protocol. We consider a "Move to Right" (MTR) request allocation strategy where each requester is allocated to the nearest available server to its right. We start our analysis from a single resource per request scenario where each requester demands a single computational resource. We map this scenario to an M/M/1 queue or a bulk service M/M/1 queue depending on the server capacity. We compare the performance of the MTR strategy with the globally optimal strategy taking "expected distance traveled by a request" (request distance) as performance metric. Next, we extend our analysis to two resources per request scenario. We show that the behavior of MTR can be transformed into an equivalent fork-join queue problem. Numerical results are presented to validate the claim.
Stability of a standard decentralised medium access
Authors: Shneer Seva , Stolyar Alexander
Published: January 2019

We consider a stochastic queueing system modelling the behaviour of a wireless network with nodes employing a discrete-time version of the standard decentralised medium access algorithm. The system is unsaturated " each node receives an exogenous flow of packets at the rate ! packets per time slot. Each packet takes one slot to transmit, but neighbouring nodes cannot transmit simultaneously. The algorithm we study is standard in that: a node with empty queue does not compete for medium access; the access procedure by a node does not depend on its queue length, as long as it is non-zero. Two system topologies are considered, with nodes arranged in a circle and in a line. We prove that, for either topology, the system is stochastically stable under condition ! < 2/5. This result is intuitive for the circle topology as the throughput each node receives in a saturated system (with infinite queues) is equal to the so-called parking constant, which is larger than 2/5. (This fact, however, does not help to prove our result.) The result is not intuitive at all for the line topology as in a saturated system some nodes receive a throughput lower than 2/5.
Convex Prophet Inequalities
Authors: Qin Junjie , Rajagopal Ram , Vardi Shai , Wierman Adam
Published: January 2019

We introduce a new class of prophet inequalities-convex prophet inequalities-where a gambler observes a sequence of convex cost functions ci(xi) and is required to assign some fraction 0 ≤ xi ≤ 1 to each, such that the sum of assigned values is exactly 1. The goal of the gambler is to minimize the sum of the costs. We provide an optimal algorithm for this problem, a dynamic program, and show that it can be implemented in polynomial time when the cost functions are polynomial. We also precisely characterize the competitive ratio of the optimal algorithm in the case where the gambler has an outside option and there are polynomial costs, showing that it grows as Θ(np-1/l), where n is the number of stages, p is the degree of the polynomial costs and the coefficients of the cost functions are bounded by [l, u].
On Min-Max Optimization Over Large Data Sets
Authors: Ghosh Soumyadip , Squillante Mark S. , Wollega Ebisa D.
Published: January 2019

We consider a general min-max optimization formulation defined over a sample space X, probability distribution P on X