bluuebunny/crossref_metadata_2025 huggingface dataset:
Maternal Body Mass Index and Regional Anaesthesia Use at Term: Prevalence and Complications
Authors: Biel Frances M. , Marshall Nicole E. , Snowden Jonathan M.
Published: August 2017

Background

There is an evidence gap regarding the use of regional anaesthesia (epidural, spinal, or combined epidural/spinal anaesthesia) and associated complications by maternal body mass index (BMI). We examine associations between regional anaesthesia, mode of delivery, and regional anaesthesia complications by pre‐pregnancy BMI categories among term deliveries.

Methods

Retrospective cohort study of births in California, 2007‐2010, utilizing linked birth certificate data and patient discharge data. Outcomes were mode of delivery (among laboured deliveries) and select regional anaesthesia complications. Multivariable Poisson regression was used to adjust for maternal characteristics.

Results

In women undergoing labour (i.e. laboured delivery), women with higher BMI categories were more likely to receive regional analgesia in a dose–response fashion (adjusted risk ratio [RR] 1.10, 95% confidence interval [CI] 1.10, 1.11 for primiparous women with category I obesity), and in those receiving regional anaesthesia, were less likely to deliver vaginally (e.g. RR 0.85, 95% CI 0.84, 0.85 for the same category of women). Regional anaesthesia complications displayed a complex relationship with maternal BMI, with women in intermediate obesity categories having decreased odds as compared to normal‐weight women, and women in the highest BMI category having a twofold increased risk of complications (RR 2.34, 95% CI 1.37, 4.02 for primiparous women).

Conclusion

Labouring women in higher BMI categories were more likely to receive regional anaesthesia and more likely to deliver via caesarean compared to normal weight women and women without regional anaesthesia. Rates of anaesthesia complications were highest among women in the highest BMI category.
Multiplex Network Analysis for Complex Governance Systems Using Surveys and Online Behavior
Authors: Hayes Adam L. , Scott Tyler A.
Published: August 2017

Text analysis, web scraping, and other computational techniques enable policy network researchers to efficiently obtain objective measures of network connections. However, the extent to which these observational methods differ from traditional survey instrument‐based measures remains an open question. Focusing on a large regional policy network of 221 organizations, this study compares a measure of collaboration generated via survey instrument to two different measures based upon internet hyperlinks and Twitter interactions between network actors. We address two questions: (1) To what extent do objective network measures based upon observed online interactions and subjective measures based upon self‐reported relationships reveal the same inter‐organizational partnerships and structural network dynamics? and (2) How useful are online network measures for supplementing survey‐based network measures? We find a significant, but substantively small, correlation between survey‐based measures and online interactions. Thus, online network measures may complement survey‐based measures, but likely reflect different aspects of the overall policy network. We conclude by discussing the potential for multiplex measures of policy networks that draw upon multiple measures to more fully understand policy network landscapes. These results bridge and help to contextualize prior work on policy network measures and virtual policy networks within the broader context of complex governance systems.
A Naturalist Ontology of Instantiation
Authors: Cumpa Javier
Published: August 2017

The aim of this paper is to defend a naturalistic approach to instantiation and the Principle of Instantiation. I argue that the instantiation of an ordinary property F consists of two coordinated relationships at the levels of the manifest and scientific images, namely, constituency and entailment. Also, I offer an account of the Principle of Instantiation related to this conception of instantiation based on the notion of scientific prediction.
Genotype and attachment technique influence the growth and survival of line nursery corals
Authors: Goergen Elizabeth A. , Ostroff Zachary , Gilliam David S.
Published: August 2017

The Caribbean staghorn coral, Acropora cervicornis, was once a dominant habitat creating coral, but its populations have declined dramatically in recent decades. Numerous restoration efforts now utilize coral gardening techniques to cultivate this species, growing colonies on fixed structures or from line/suspended nurseries. Line nurseries have become increasingly popular because of their small footprint and ease of use, replacing fixed structures in many nurseries. To evaluate the efficacy of the line technique, this study evaluated growth, condition, and survivorship of A. cervicornis nursery colonies of three distinct genotypes grown via two line nursery techniques (suspended and direct line attachment [vertical]). Direct line attachment of nursery colonies resulted in poor survival (43%) and growth (9.5 ± 1.33 cm/year), whereas suspended culture had 100% survival and increased growth (61.1 ± 4.19 cm/year). Suspended culture had significantly reduced disease prevalence and prevented colony predation. Suspended coral growth was also comparable to a neighboring fixed structure nursery (55.2 ± 7.86 cm/year), and found to be as effective in propagating corals as fixed structures.
Rapid understory plant recovery following forest floor protection on temporary drilling pads
Authors: Jones Caren E. , Bachmann Sascha , Lieffers Victor J. , Landhäusser Simon M.
Published: August 2017

Oil sands exploration fragments the boreal landscape by constructing numerous drilling pads to assess underground petroleum reserves. Reclamation of these pads is challenging and slow, particularly for forest understory species. We investigated the feasibility of accelerated forest understory restoration on these temporary pads by taking advantage of the propagule bank and clonal regeneration strategy of many boreal plants. We covered and protected the forest floor (FF) with subsoil during winter pad construction. This forest floor protection (FFP) method was then compared with the current practice of stripping off, stockpiling, and then replacing the FF during the reclamation phase (rollback, RB) and to conventional clearcut (CC) harvesting. In the first growing season, surface disturbance as well as richness and cover of plant regeneration was evaluated; vegetation assessment was repeated in the fifth growing season. Although there were some slight differences between the communities in the FFP and CC treatments, likely associated with varying levels of residual slash and subsoil material, there were striking differences between the communities in the RB and FFP treatments. In addition, while establishment of deciduous tree species was similar between the FFP and CC treatments, there were very few trees found in the RB treatment. The study indicates that protection and careful uncovering of the FF during temporary drilling pad construction should be a technique of choice for forest reclamation used in the boreal forest. However, as RB will still play a part in the reclamation of these sites, management intervention will be required to achieve reclamation goals.
Bumble bee colony growth and reproduction on reclaimed surface coal mines
Authors: Lanterman Jessie , Goodell Karen
Published: August 2017

Reclamation of coal mine lands in the eastern United States creates pockets of grassland habitat in an otherwise predominantly forested region. These sites may represent an opportunity for pollinator conservation if they provide valuable foraging habitat for wild bees. To determine site characteristics that influence bee success on reclamation lands, we monitored growth and reproduction of 24 commercially reared bumble bee (Bombus impatiens) colonies placed on 12 former coal mines (aged 2 to 30+ years post‐reclamation) in Ohio, U.S.A. Twenty colonies survived the duration of the experiment (May–August 2014). All colonies produced both new queens (mean 21.0 ± 37.0 SD) and males (36.5 ± 36.5), in proportion to overall colony size. Results of generalized linear models indicate that colony growth and reproduction increased with floral diversity and species turnover, and declined with site area and the proportion of forest in the surrounding landscape. The sex ratio of reproductive offspring was significantly more male‐biased on sites with low flower diversity, underscoring the importance of floral diversity for meeting the higher resource demands of queen production. Floral resource composition and consistency were influenced by site age and surrounding landscape. Older sites had higher floral diversity and species turnover throughout the season than younger sites, and included high‐quality native bee forage plants. We discuss the implications of this study for reclamation project managers seeking to promote bee reproduction and conservation.
VEGF synthesis is induced by prostacyclin and TGF‐β in distal lung fibroblasts from COPD patients and control subjects: Implications for pulmonary vascular remodelling
Authors: Westergren‐Thorsson Gunilla , Bagher Mariam , Andersson‐Sjöland Annika , Thiman Lena , Löfdahl Claes‐Göran , Hallgren Oskar , Bjermer Leif , Larsson‐Callerfelt Anna‐Karin
Published: August 2017

ABSTRACT

Background and objective

Involvement of pulmonary vascular remodelling is a characteristic sign in COPD. Vascular mediators such as vascular endothelial growth factor (VEGF) and prostacyclin may regulate fibroblast activity. The objective was to study the synthesis of VEGF and interactions with prostacyclin and transforming growth factor (TGF)‐β1 in lung fibroblasts from patients with COPD and healthy control subjects. To further explore the autocrine role of synthesized VEGF on fibroblast activity, studies were performed in human lung fibroblasts (HFL‐1).

Methods

Primary distal lung fibroblast cultures were established from healthy individuals and from COPD patients (GOLD stage IV). Lung fibroblasts were stimulated with the prostacyclin analogue iloprost and the profibrotic stimuli TGF‐β1. VEGF synthesis was measured in the cell culture medium. Changes in proliferation rate, migration and synthesis of the extracellular matrix (ECM) proteins proteoglycans were analysed after stimulations with VEGF‐A isoform 165 (VEGF165; 1–10 000 pg/mL) in HFL‐1.

Results

Iloprost and TGF‐β1 significantly increased VEGF synthesis in both fibroblasts from COPD patients and control subjects. TGF‐β1‐induced VEGF synthesis was significantly reduced by the cyclooxygenase inhibitor indomethacin in fibroblasts from COPD patients. VEGF significantly increased proliferation rate and migration capacity in HFL‐1. VEGF also significantly increased synthesis of the ECM proteins biglycan and perlecan. The VEGF receptors (VEGFR), VEGFR1, VEGFR2 and VEGFR3, were all expressed in primary lung fibroblasts and HFL‐1.

Conclusion

VEGF is synthesized in high amounts by distal lung fibroblasts and may have a crucial role in ongoing vascular remodelling processes in the distal lung compartments.
Identifying foreign suppliers in U.S. import data
Authors: Kamal Fariha , Monarch Ryan
Published: August 2017

Relationships between firms and their foreign suppliers are the foundation of international trade, but data limitations and reliability concerns make studying such relationships challenging. We evaluate and enhance supplier information in U.S. import data and present new facts about importer–exporter relationships. Count of foreign exporters from U.S. import data tends to exceed those from source country data, especially from China. The pattern of U.S. imports from origin countries changes substantially by tracing trade back to the supplier's location instead. Related‐party relationships trade more, while larger countries have more relationships.
Two‐Aggregate Games: Demonstration Using a Production–Appropriation Model
Authors: Cornes Richard , Hartley Roger , Tamura Yuji
Published: August 2017

We expand the scope of the two‐aggregate method by applying it to a situation in which many heterogeneous players are free to contribute to both aggregates. Such situations naturally arise in various resource allocation problems. Hence, our method is useful in many applications. A production–appropriation model is employed to illustrate how the problem of establishing the Nash equilibrium can be reduced from solving n>2 best‐response functions in n unknowns to solving two consistency conditions in two unknowns. We then conduct a comparative static exercise that the conventional approach could not handle easily, if at all, to demonstrate the power of our method.
Body language reading of emotion in schizophrenia: Associations with symptoms and functional outcome
Authors: Engelstad Katharina Nymo , Sundet Kjetil S. , Andreassen Ole A. , Vaskinn Anja
Published: August 2017

Our aim was to explore how body language reading of emotion relates to neurocognition, symptoms and functional outcome in schizophrenia. Fifty‐four individuals with schizophrenia and eighty‐four healthy controls participated in the study. Emotion perception was assessed with a point‐light display (PLD) task, the Emotion in Biological Motion (EmoBio) test, neurocognition was measured with the MATRICS Consensus Cognitive Battery (MCCB), and functioning was indexed by one measure of functional capacity and by one self‐report questionnaire. Clinical symptoms were assessed with a five factor Positive and Negative Syndrome Scale (PANSS) symptoms model. Participants with schizophrenia had impaired body language reading of emotions compared to healthy controls (Cohen's d = 0.69). In participants with schizophrenia, emotion perception was associated with neurocognition (r = 0.42), functional capacity (r = 0.27) and disorganization symptoms (r = –0.27). Mediation analyses showed that disorganization symptoms mediated the effects of emotion perception and neurocognition, respectively, on social functional capacity. These results suggest that in individuals with schizophrenia, reduced emotion perception from body movements has negative consequences for functional outcome, but that the effect is mediated through disorganization symptoms.
The psychometric properties of the Portuguese version of the Personality Inventory for DSM‐5
Authors: Pires Rute , Sousa Ferreira Ana , Guedes David
Published: August 2017

The DSM‐5 Section III proposes a hybrid dimensional‐categorical model of conceptualizing personality and its disorders that includes assessment of impairments in personality functioning (criterion A) and maladaptive personality traits (criterion B). The Personality Inventory for the DSM‐5 is a new dimensional tool, composed of 220 items organized into 25 facets that delineate five higher order domains of clinically relevant personality differences, and was developed to operationalize the DSM‐5 model of pathological personality traits. The current studies address the internal consistency (study 1), the test‐retest reliability (study 2) and the criterion validity (studies 3 and 4) of the Portuguese version of the PID‐5 in samples of native speaking psychology students. Results indicated good internal consistency reliabilities and good temporal stability reliabilities for the majority of the PID‐5 traits. The correlational pattern of the PID‐5 traits with two measures of personality was in accordance with theoretical expectations and showed its concurrent validity.
Accounting for job satisfaction: Examining the interplay of person and situation
Authors: Elfstrand Corlin Tinna , Kazemi Ali
Published: August 2017

In the present study, we investigate the interplay of personality traits (i.e., person) in frontline care staff in nursing homes and the way they relate to the residents (i.e., situation) to account for their job satisfaction. Participants completed a survey including Mini‐IPIP tapping the five‐factor model of personality, Individualized Care Inventory tapping four aspects of person‐centered care and job satisfaction. The results revealed that staff scoring high on neuroticism experienced less job satisfaction. This relationship was partly accounted for by resident autonomy, suggesting that part of the adverse influence of neuroticism on job satisfaction may be mitigated by organizations providing a supportive care environment. In contrast, staff scoring high on agreeableness experienced higher job satisfaction. This relationship was accounted for by another aspect of person‐centered care, that is, knowing the person. This suggests that agreeableness in a sense facilitated adjustment of acts of care toward the unique needs and preferences of residents and this partly explained why the more agreeable the staff was the more they felt satisfied at work. In sum, effects of personality traits on job satisfaction in care staff are partially mediated by the perception of working conditions and care policy and to the extent that a certain personality trait affects whether the staff have a positive or negative perception of the way they relate to the residents, they will experience, respectively, higher or a lower job satisfaction. This finding has implications for how to combine a focus on delivering person‐centered care with improving personal job satisfaction.
Emergency Department Recognition of Mental Disorders and Short‐Term Risk of Repeat Self‐Harm Among Young People Enrolled in Medicaid
Authors: Bridge Jeffrey A. , Olfson Mark , Fontanella Cynthia A. , Marcus Steven C.
Published: August 2017

Previous studies of adults have shown protective associations between clinical recognition of a mental disorder in the emergency department and short‐term risk of repeat self‐harm. Similar studies of young self‐harm patients are lacking. We conducted a retrospective longitudinal cohort analysis of national Medicaid claims data in patients aged 10–19 years with self‐harm who were discharged from emergency departments to the community (N = 2,703). Emergency department mental disorder recognition was not associated with a significant change in repeat self‐harm visits during the 30‐day follow‐up period. Future studies should assess whether other aspects of emergency care influence short‐term risk of repeat self‐harm.
Interoceptive Deficits, Nonsuicidal Self‐Injury, and Suicide Attempts Among Women with Eating Disorders
Authors: Dodd Dorian R. , Smith April R. , Forrest Lauren N. , Witte Tracy K. , Bodell Lindsay , Bartlett Mary , Siegfried Nicole , Goodwin Natalie
Published: August 2017

People with eating disorders (EDs) have an elevated risk for both nonsuicidal self‐injury (NSSI) and suicide compared to the general population. This study tests two theoretically derived models examining interoceptive deficits as a risk factor for NSSI, and examining interoceptive deficits, NSSI, fearlessness about death, and pain tolerance as risk factors for suicide. Ninety‐six adult, treatment‐seeking women with EDs completed self‐report questionnaires at a single time point. Interoceptive deficits were significantly associated with NSSI, and NSSI was in turn associated with both pain tolerance and fearlessness about death. Further, pain tolerance was in turn associated with past suicide attempts, although fearlessness about death was not associated with suicide attempts. Interoceptive deficits had a direct association with fearlessness about death but not pain tolerance. Results regarding the relation between interoceptive deficits and suicide attempts were mixed, yet overall suggest that interoceptive deficits are related to suicide attempts largely indirectly, through the effects of mediating variables such as NSSI, fearlessness about death, and pain tolerance. Results suggest that interoceptive deficits and pain tolerance merit further investigation as potential risk factors for fatal and nonfatal self‐harm among individuals with EDs.
New Social Program Participation During the Great Recession: The Case of SNAP*
Authors: Grieger Lloyd
Published: August 2017

Objectives

It is unknown if the explosion in Supplemental Nutrition Assistance Program (SNAP) usage during the Great Recession was due to an inflow of new participants or instead because former participants cycled back into the program. It is also unknown if the profiles of new and return participants differed on a set of core demographic characteristics, including race/ethnicity, gender, education, age, household configuration, and location.

Methods

I examine the complete adult SNAP participation histories for a nationally representative cross‐section of 7,680 individuals at the end of the Great Recession. Data are from the Panel Study of Income Dynamics with observations spanning the period 1968–2010.

Results

A large number of adult SNAP participants used the program for the first time during the Great Recession. New participants were not solely young adults and often originated from groups not typically associated with social program participation, such as: whites, suburbanites, and the highly educated. Repeat participants had varying program histories prior to the recession. Some spent a substantial portion of adulthood receiving program benefits while most others were only sporadic participants.

Conclusions

The findings demonstrate that SNAP was very successful in reaching the many new types of people who were exposed to the risk of poverty as a result of the economic downturn.
A CRY–BIC negative‐feedback circuitry regulating blue light sensitivity of Arabidopsis
Authors: Wang Xu , Wang Qin , Han Yun‐Jeong , Liu Qing , Gu Lianfeng , Yang Zhaohe , Su Jun , Liu Bobin , Zuo Zecheng , He Wenjin , Wang Jian , Liu Bin , Matsui Minami , Kim Jeong‐Il , Oka Yoshito , Lin Chentao
Published: August 2017

Cryptochromes are blue light receptors that regulate various light responses in plants. Arabidopsis cryptochrome 1 (CRY1) and cryptochrome 2 (CRY2) mediate blue light inhibition of hypocotyl elongation and long‐day (LD) promotion of floral initiation. It has been reported recently that two negative regulators of Arabidopsis cryptochromes, Blue light Inhibitors of Cryptochromes 1 and 2 (BIC1 and BIC2), inhibit cryptochrome function by blocking blue light‐dependent cryptochrome dimerization. However, it remained unclear how cryptochromes regulate the BIC gene activity. Here we show that cryptochromes mediate light activation of transcription of the BIC genes, by suppressing the activity of CONSTITUTIVE PHOTOMORPHOGENIC 1 (COP1), resulting in activation of the transcription activator ELONGATED HYPOCOTYL 5 (HY5) that is associated with chromatins of the BIC promoters. These results demonstrate a CRY–BIC negative‐feedback circuitry that regulates the activity of each other. Surprisingly, phytochromes also mediate light activation of BIC transcription, suggesting a novel photoreceptor co‐action mechanism to sustain blue light sensitivity of plants under the broad spectra of solar radiation in nature.
The in vitro antibacterial activity of incomplete iron salt of polyacrylic acid against Pseudomonas aeruginosa, meticillin‐resistant Staphylococcus pseudintermedius and meticillin‐resistant S. aureus
Authors: Solc Meghan K. , Weese J. Scott , Jazic Edward
Published: August 2017

Background

The incomplete iron salt of polyacrylic acid (IIS‐PAA) has been used for its haemostatic, wound healing and antibacterial properties in human patients. IIS‐PAA is a water‐soluble, acidic, hydrophilic polymer that is active at pH 2.9–4.0.

Hypotheses/Objectives

To evaluate the antibacterial effect of IIS‐PAA against Pseudomonas aeruginosa, meticillin‐resistant Staphylococcus pseudintermedius (MRSP) and meticillin‐resistant S. aureus (MRSA).

Methods

This was a prospective, nonblinded in vitro study. Sixty canine isolates of P. aeruginosa, MRSP and MRSA were included. Minimum inhibitory concentrations (MICs) of IIS‐PAA were determined by agar dilution on Mueller–Hinton agar using testing concentrations ranging from 0.0625–0.4% (raw material 100%) and based on Clinical and Laboratory Standards Institute guidelines.

Results

The median MIC for P. aeruginosa was 0.2% (range 0.2–0.3%), mean 0.2% and standard deviation (SD) of 0.018%. The median MIC for MRSP was 0.05% (0.025–0.1%), mean 0.058% and SD 0.022%, and the median MIC for MRSA was 0.1% (0.00625–0.4%), mean 0.126% and SD 0.080%. There were significant differences in MICs between the three bacteria types with MICs highest for Pseudomonas and lowest for MRSP (all P < 0.0001).

Conclusions

IIS‐PAA had in vitro antibacterial activity against three important bacterial pathogens. Further studies of IIS‐PAA are indicated to assess the potential clinical benefit and in vitro studies to investigate the spectrum of anti‐bacterial activity and mode of action.
A novel jig arm to measure tibial plateau angle during tibial plateau leveling osteotomy
Authors: Restle Kyle N. , Biskup Jeffery J.
Published: August 2017

Objective

To determine the ability of a novel device attached to the proximal tibial plateau leveling osteotomy (TPLO) jig pin to accurately predict intraoperative change in tibial plateau angle (TPA).

Study design

In vitro cadaveric study.

Sample population

Left hindlimbs of adult dogs (n = 9).

Methods

A modified Slocum tibial plateau leveling (TPL) jig with the Rotational Osteotomy Measuring Arm (ROMA) was placed on the tibia and a radial TPLO osteotomy was performed. Based on preoperative radiographic TPA measurements, the proximal segment was rotated using the traditional method of marking points on the osteotomy a specified distance apart. After rotation, the predicted TPA was recorded based on the ROMA. Postoperative TPA was measured on radiographs. The ability of the ROMA to predict postoperative TPA was compared to that of the traditional method.

Results

The average final TPA achieved with the traditional method was 6.4° (range, 3.0‐10.0°). The ROMA predicted a final TPA of 5.8° (range, 3.8‐10.1°). No significant difference was found between the TPA predicted based on the traditional method and ROMA method.

Conclusion

The ROMA may be an alternative to the traditional method of measuring proximal segment rotation during TPLO procedure.

Clinical relevance

Performing a TPLO with the ROMA may accurately predict the postoperative TPA while eliminating the need for measuring chord length, making reference marks, or referencing TPA charts for various osteotomy blade sizes.
Renal denervation decreases susceptibility of the heart to ventricular fibrillation in a canine model of chronic kidney disease
Authors: Tang Xiaotie , Shi Lang , Cui Xuebin , Yu Yang , Qi Ting , Chen Cheng , Tang Xianglei
Published: August 2017

New Findings

What is the central question of this study?

Renal denervation (RDN) has been shown to be effective and safe, resulting in better control of blood pressure and an improvement in left ventricular hypertrophy in chronic kidney disease (CKD) patients. Ventricular arrhythmias and sudden cardiac death are common causes of death in CKD patients, but previous studies pay almost no attention to the effects of RDN on the risk of ventricular fibrillation associated with CKD.

What is the main finding and its importance?

Renal denervation could decrease susceptibility of the heart to ventricular fibrillation in a canine CKD model. Improvement of left ventricular hypertrophy, sympathetic activation and inflammation by RDN may be responsible for its beneficial effects.

Renal denervation (RDN) has been shown to have therapeutic value in patients with chronic kidney disease (CKD). The aim of this study was to investigate whether RDN could decrease the susceptibility of the heart to ventricular fibrillation in a canine model of CKD. Twenty‐one dogs were used. Chronic kidney disease was produced by subtotal nephrectomy in 16 dogs with RDN treatment (CKD + RDN group, n = 8) or sham RDN (CKD group, n = 8). Another five dogs underwent sham operation and sham RDN to serve as controls (CTR group). Parameters of renal function, blood pressure, echocardiography, ECG, noradrenaline and inflammation were measured at baseline and 6 weeks after the surgical procedure. The ventricular fibrillation threshold (VFT) was determined at the end of the study. Subtotal nephrectomy successfully induced a canine CKD model. When compared with the CTR group, subtotal nephrectomy in the CKD group significantly elevated blood pressure; increased the left ventricular mass, end‐diastolic left ventricular internal dimension, left ventricular end‐diastolic posterior wall thickness and end‐diastolic interventricular septum thickness; prolonged the QT interval, corrected QT interval, the interval from the peak to the end of the T wave (Tp‐e) and the corrected Tp‐e interval; and increased the QT dispersion and the Tp‐e/QT ratio; decreased the VFT; and increased the serum concentrations of noradrenaline, C‐reactive protein and interleukin‐6. Renal denervation significantly attenuated these changes induced by CKD. The study demonstrated that RDN could decrease the susceptibility of the heart to ventricular fibrillation in this CKD model. Improvement of left ventricular hypertrophy, sympathetic activation and inflammation by RDN may be responsible for its beneficial effects.
Door Latch Failure Risk Identification Using Virtual Testing Methods
Authors: Friedman Keith , Bui Khanh , Hutchinson John
Published: August 2017

Vehicle door latch performance testing presently utilizes uniaxial quasi-static loading conditions. Current technology enables sophisticated virtual testing of a broad range of systems. Door latch failures have been observed in vehicles under a variety of conditions. Typically, these conditions involve multi-axis loading conditions. The loading conditions presented during rollovers on passenger vehicle side door latches have not been published. Rollover crash test results, rollover crashes, and physical Federal Motor Vehicle Safety Standard (FMVSS) 206 latch testing results are reviewed. The creation and validation of a passenger vehicle door latch model is described. The multi-axis loading conditions observed in virtual rollover testing at the latch location are characterized and applied to the virtual testing of a latch in the secondary latch position. The results are then compared with crash test and real world rollover results for the same latch. The results indicate that a door latch that meets the secondary latch position requirements may fail at loads substantially below the FMVSS 206 uniaxial failure loads. In the side impact mode, risks associated with door handle designs and the potential for inertial release can be considered prior to manufacturing with virtual testing. An example case showing the effects of material and spring selection illustrates the potential issues that can be detected in advance of manufacturing. The findings suggest the need for re-examining the relevance of existing door latch testing practices in light of the prevalence of rollover impacts and other impact conditions in today's vehicle fleet environment.
Nonlinear Dynamics of Flexible Rotors Supported on Journal Bearings—Part II: Numerical Bearing Model
Authors: Miraskari Mohammad , Hemmati Farzad , Gadala Mohamed S.
Published: August 2017

The nonlinear stability of a flexible rotor-bearing system supported on finite length journal bearings is addressed. A perturbation method of the Reynolds lubrication equation is presented to calculate the bearing nonlinear dynamic coefficients, a treatment that is suitable to any bearing geometry. A mathematical model, nonlinear coefficient-based model, is proposed for the flexible rotor-bearing system for which the journal forces are represented through linear and nonlinear dynamic coefficients. The proposed model is then used for nonlinear stability analysis in the system. A shooting method is implemented to find the periodic solutions due to Hopf bifurcations. Monodromy matrix associated to the periodic solution is found at any operating point as a by-product of the shooting method. The eigenvalue analysis of the Monodromy matrix is then carried out to assess the bifurcation types and directions due to Hopf bifurcation in the system for speeds beyond the threshold speed of instability. Results show that models with finite coefficients have remarkably better agreement with experiments in identifying the boundary between bifurcation regions. Unbalance trajectories of the nonlinear system are shown to be capable of capturing sub- and super-harmonics which are absent in the linear model trajectories.
A New Parabolic Sliding Mode Filter Augmented by a Linear Low-Pass Filter and Its Application to Position Control
Authors: Aung Myo Thant Sin , Shi Zhan , Kikuuwe Ryo
Published: August 2017

This paper proposes a new sliding mode filter augmented by a linear low-pass filter (LPF) for mitigating the effect of high-frequency noise. It is based on the derivation of three new variants of Jin et al.'s (2012, “Real-Time Quadratic Sliding Mode Filter for Removing Noise,” Adv. Rob., 26(8–9), pp. 877–896) parabolic sliding mode filter (J-PSMF) and investigation on their frequency-response characteristics. The new filter is developed by augmenting one of the variants of J-PSMF by a second-order linear LPF. It has better balance between the noise attenuation and signal preservation than both linear LPFs and J-PSMF. The effectiveness of the new filter is experimentally evaluated on a direct current (DC) servomotor equipped with an optical encoder. This paper also shows the application of the proposed filter to a positioning system under PDD2 (proportional, derivative, and second derivative) control, which successfully realizes the noise attenuation and the nonovershooting response simultaneously.
Kinematic Locomotion Modes of Particle-Based Linear Chain Mechanisms
Authors: Alshorman Ahmad , Hurmuzlu Yildirim
Published: August 2017

Researchers often use mechanisms that consist of massless rods and concentrated masses in order to capture the dynamics of robotic locomotors. A kinematic prototyping tool that captures all possible locomotion modes of a given kinematic mechanism can be very useful in conceiving and designing such systems. Previously, we proposed a family of mechanisms that consist of two types of primitive building units: a single mass with a built-in revolute joint and a massless connection rod. This family starts from a single bouncing mass and progressively evolves into more complex generations. In this paper, we present a prototyping tool that generates all possible locomotion cycles of particle-based linear chain mechanisms. A new skip impact concept is introduced to describe the relative motion of the moving masses and the masses on the ground. Also, the paper represents a graphical user interface (GUI) that facilitates data input and the visualization of the locomotion modes.
Uncertainty and Disturbance Estimator-Based Robust Trajectory Tracking Control for a Quadrotor in a Global Positioning System-Denied Environment
Authors: Lu Qi , Ren Beibei , Parameswaran Siva , Zhong Qing-Chang
Published: August 2017

This paper addresses the problem of autonomous trajectory tracking control for a quadrotor in a global positioning system (GPS)-denied environment using only onboard sensing. To achieve that goal, it requires accurate estimation of quadrotor states followed by proper control actions. For the position estimation in a GPS-denied environment, an open source high speed optical flow sensor PX4FLOW is adopted. As for the quadrotor control, there are several challenges due to its highly nonlinear system dynamics, such as underactuation, coupling, model uncertainties, and external disturbances. To deal with those challenges, the cascaded inner–outer uncertainty and disturbance estimator (UDE)-based robust control scheme has been developed and applied to the attitude and position control of a quadrotor. Extensive real flight experiments, including attitude stabilization, hover, disturbance rejection, trajectory tracking, and comparison with the proportional–integral–derivative (PID) controller are carried out to demonstrate the effectiveness of the developed UDE-based controllers.
A Thin Elastic Membrane Conformed to a Soft and Rough Substrate Subjected to Stretching/Compression
Authors: Wang Liu , Qiao Shutao , Kabiri Ameri Shideh , Jeong Hyoyoung , Lu Nanshu
Published: August 2017

Conformability of bio-integrated electronics to soft and microscopically rough biotissues can enhance effective electronics–tissue interface adhesion and can facilitate signal/heat/mass transfer across the interface. When biotissues deform, for example, when skin stretches or heart beats, the deformation may lead to changes in conformability. Although a theory concerning just full conformability (FC) under deformation has been developed (i.e., the FC theory), there is no available theory for partially conformable (PC) systems subjected to deformation. Taking advantage of the path-independent feature of elastic deformation, we find that the total energy of a PC system subjected to stretching or compression can be analytically expressed and minimized. We discover that the FC theory is not sufficient in predicting FC and a full energy landscape obtained by our PC theory is needed for searching for the equilibrium. Our results reveal that stretching enhances conformability while compression degrades it. In addition to predicting the critical parameters to maintain FC under deformation, our PC theory can also be applied to predict the critical compressive strain beyond which FC is lost. Our theory has been validated by laminating poly(methyl methacrylate) (PMMA) membranes of different thicknesses on human skin and inducing skin deformation.
A Novel Iris Mechanism for Solar Thermal Receivers
Authors: Ophoff Cédric , Ozalp Nesrin
Published: August 2017

Variable aperture mechanisms are being used in many fields including medicine, electronics, fluid mechanics, and optics. The main design characteristics of these aperture concepts are the use of multiple blades regulating aperture area and consequently the incoming medium flow. Manufacturing complexities primarily depend on the concept geometry, material, and the process application requirements. Design of a variable aperture demands meticulous methodology and careful consideration of the application field. This paper provides an in-depth methodology on the design of a novel iris mechanism for temperature control in high temperature solar thermal receivers and solar reactors. Such methodology can be used as a guideline for iris mechanisms implemented in other applications as well as in design of different apparatuses exposed to high temperature. Optical simulations in present study have been performed to demonstrate enhanced performance of the iris mechanism over conventional Venetian blind shutter serving as optical attenuators in concentrating solar power systems. Results showed that optical absorption efficiency is improved by 14% while reradiation loss through the aperture is reduced by 2.3% when the iris mechanism is used. Correlation for adaptive control of aperture area was found through computational surface area measurement. Experimental testing with a 7 kW solar simulator at different power levels demonstrated the performance of the mechanism to maintain stable temperature under variable flux.
Vanadium, niobium and tantalum by XPS
Authors: Buabthong Pakpoom , Becerra Stasiewicz Natalie , Mitrovic Slobodan , Lewis Nathan S.
Published: August 2017

We present high-resolution XPS spectra of elemental vanadium, niobium and tantalum sputter-cleaned by Ar+ ions. The energy scales are shown without applying any corrections, and the position of the Fermi level was verified to be at zero binding energy within better than 0.1 eV, as determined from the Fermi edge measurement.
Nonlinearities and shear banding instability of polyacrylamide solutions under large amplitude oscillatory shear
Authors: Goudoulas Thomas B. , Pan Sharadwata , Germann Natalie
Published: August 2017

The response of semidilute entangled and salt-free solutions of aqueous polyacrylamide under large amplitude oscillatory shear deformations was studied in this work. We systemically probed the effects of four polymer concentrations from 5 to 15 wt. % and two molecular weights (5–6 and 18 M) at De > 1. The mitlaos software package was utilized to analyze the nonlinear moduli, among other nonlinear parameters. We found that the polymer concentration is the dominant parameter controlling the progression into the nonlinear regime. The trends of elastic decomposition indicate an intensive strain-rate softening behavior under high strain amplitudes. At high strain rates and at higher concentrations, however, a gradual transition from shear thickening to shear thinning could be noticed for the viscous dissipation. In addition, the effect of the measuring geometry was also considered, since the rheometer was coupled with a particle image velocimetry (PIV) system in the second part of this study. The PIV results suggest that the flow field is significantly altered during the oscillatory cycle. Banded profiles were observed for both molecular weights studied.
Multiplex quantitative assays indicate a need for reevaluating reported small-molecule TrkB agonists
Authors: Boltaev Umed , Meyer Yves , Tolibzoda Farangis , Jacques Teresa , Gassaway Madalee , Xu Qihong , Wagner Florence , Zhang Yan-Ling , Palmer Michelle , Holson Edward , Sames Dalibor
Published: August 2017

Quantitative assays suggest that several reported agonists of the receptor TrkB do not indeed activate TrkB signaling.
A systems approach for discovering linoleic acid derivatives that potentially mediate pain and itch
Authors: Ramsden Christopher E. , Domenichiello Anthony F. , Yuan Zhi-Xin , Sapio Matthew R. , Keyes Gregory S. , Mishra Santosh K. , Gross Jacklyn R. , Majchrzak-Hong Sharon , Zamora Daisy , Horowitz Mark S. , Davis John M. , Sorokin Alexander V. , Dey Amit , LaPaglia Danielle M. , Wheeler Joshua J. , Vasko Michael R. , Mehta Nehal N. , Mannes Andrew J. , Iadarola Michael J.
Published: August 2017

Linoleic acid derivatives that may cause itchiness and headache pain are identified.
The adaptor molecule RIAM integrates signaling events critical for integrin-mediated control of immune function and cancer progression
Authors: Patsoukis Nikolaos , Bardhan Kankana , Weaver Jessica D. , Sari Duygu , Torres-Gomez Alvaro , Li Lequn , Strauss Laura , Lafuente Esther M. , Boussiotis Vassiliki A.
Published: August 2017

Functional analyses of the adaptor molecule RIAM highlight the importance of integrin-mediated signaling in immune function and cancer biology.
Virally enhanced immunotherapy
Authors: Ferrarelli Leslie K.
Published: August 2017

A strategy combining immunotherapies with a tumor-targeted virus may be a new treatment option for glioblastoma patients.
Papers of note in
Nature
548
(7667)
Authors: Ferrarelli Leslie K.
Published: August 2017

This week’s articles describe signals that underscore the development of taste sensation, T cell populations, and melanoma drug resistance.
Antimicrobial Activity of Ceftazidime-Avibactam Tested against Multidrug-Resistant Enterobacteriaceae and Pseudomonas aeruginosa Isolates from U.S. Medical Centers, 2013 to 2016
Authors: Sader Helio S. , Castanheira Mariana , Shortridge Dee , Mendes Rodrigo E. , Flamm Robert K.
Published: August 2017

The
in vitro
activity of ceftazidime-avibactam and many comparator agents was determined against various resistant subsets of organisms selected among 36,380
Enterobacteriaceae
and 7,868
Pseudomonas aeruginosa
isolates. The isolates were consecutively collected from 94 U.S. hospitals, and all isolates were tested for susceptibility by reference broth microdilution methods in a central monitoring laboratory (JMI Laboratories).
Enterobacteriaceae
isolates resistant to carbapenems (CRE) and/or ceftazidime-avibactam (MIC ≥ 16 μg/ml) were evaluated for the presence of genes encoding extended-spectrum β-lactamases and carbapenemases. Ceftazidime-avibactam inhibited >99.9% of all
Enterobacteriaceae
at the susceptible breakpoint of ≤8 μg/ml and was active against multidrug-resistant (MDR;
n
= 2,953; MIC
50/90
, 0.25/1 μg/ml; 99.2% susceptible), extensively drug-resistant (XDR;
n
= 448; MIC
50/90
, 0.5/2 μg/ml; 97.8% susceptible), and CRE (
n
= 513; MIC
50/90
, 0.5/2 μg/ml; 97.5% susceptible) isolates. Only 82.2% of MDR
Enterobacteriaceae
(
n
= 2,953) and 64.2% of ceftriaxone-nonsusceptible
Klebsiella pneumoniae
(
n
= 1,063) isolates were meropenem susceptible. Among
Enterobacter cloacae
(22.2% ceftazidime nonsusceptible), 99.8% of the isolates, including 99.3% of the ceftazidime-nonsusceptible isolates, were ceftazidime-avibactam susceptible. Only 23 of 36,380
Enterobacteriaceae
(0.06%) isolates were ceftazidime-avibactam nonsusceptible, including 9 metallo-β-lactamase producers and 2 KPC-producing strains with porin alteration; the remaining 12 strains showed negative results for all β-lactamases tested. Ceftazidime-avibactam showed potent activity against
P. aeruginosa
(MIC
50/90
, 2/4 μg/ml; 97.1% susceptible), including MDR (MIC
50/90
, 4/16 μg/ml; 86.5% susceptible) isolates, and inhibited 71.8% of isolates nonsusceptible to meropenem, piperacillin-tazobactam, and ceftazidime (
n
= 628). In summary, ceftazidime-avibactam demonstrated potent activity against a large collection (
n
= 44,248) of contemporary Gram-negative bacilli isolated from U.S. patients, including organisms resistant to most currently available agents, such as CRE and meropenem-nonsusceptible
P. aeruginosa
.
Pharmacokinetics, Tolerability, and Bacteriological Response of Rifampin Administered at 600, 900, and 1,200 Milligrams Daily in Patients with Pulmonary Tuberculosis
Authors: Aarnoutse R. E. , Kibiki G. S. , Reither K. , Semvua H. H. , Haraka F. , Mtabho C. M. , Mpagama S. G. , van den Boogaard J. , Sumari-de Boer I. M. , Magis-Escurra C. , Wattenberg M. , Logger J. G. M. , te Brake L. H. M. , Hoelscher M. , Gillespie S. H. , Colbers A. , Phillips P. P. J. , Plemper van Balen G. , Boeree M. J.
Published: August 2017

In a multiple-dose-ranging trial, we previously evaluated higher doses of rifampin in patients for 2 weeks. The objectives of the current study were to administer higher doses of rifampin for a longer period to compare the pharmacokinetics, safety/tolerability, and bacteriological activity of such regimens. In a double-blind, randomized, placebo-controlled, phase II clinical trial, 150 Tanzanian patients with tuberculosis (TB) were randomized to receive either 600 mg (approximately 10 mg/kg of body weight), 900 mg, or 1,200 mg rifampin combined with standard doses of isoniazid, pyrazinamide, and ethambutol administered daily for 2 months. Intensive pharmacokinetic sampling occurred in 63 patients after 6 weeks of treatment, and safety/tolerability was assessed. The bacteriological response was assessed by culture conversion in liquid and solid media. Geometric mean total exposures (area under the concentration-versus-time curve up to 24 h after the dose) were 24.6, 50.8, and 76.1 mg · h/liter in the 600-mg, 900-mg, and 1,200-mg groups, respectively, reflecting a nonlinear increase in exposure with the dose (
P
< 0.001). Grade 3 adverse events occurred in only 2 patients in the 600-mg arm, 4 patients in the 900-mg arm, and 5 patients in the 1,200-mg arm. No significant differences in the bacteriological response were observed. Higher daily doses of rifampin (900 and 1,200 mg) resulted in a more than proportional increase in rifampin exposure in plasma and were safe and well tolerated when combined with other first-line anti-TB drugs for 2 months, but they did not result in improved bacteriological responses in patients with pulmonary TB. These findings have warranted evaluation of even higher doses of rifampin in follow-up trials. (This study has been registered at ClinicalTrials.gov under identifier NCT00760149.)