bluuebunny/crossref_metadata_2025 huggingface dataset:
Energy Decompositions for Moist Boussinesq and Anelastic Equations with Phase Changes
Authors: Marsico David H. , Smith Leslie M. , Stechmann Samuel N.
Published: September 2019

To define a conserved energy for an atmosphere with phase changes of water (such as vapor and liquid), motivation in the past has come from generalizations of dry energies—in particular, from gravitational potential energy ρgz. Here a new definition of moist energy is introduced, and it generalizes another form of dry potential energy, proportional to θ2, which is valuable since it is manifestly quadratic and positive definite. The moist potential energy here is piecewise quadratic and can be decomposed into three parts, proportional to bu2Hu, bs2Hs, and M2Hu, which represent, respectively, buoyant energies and a moist latent energy that is released upon a change of phase. The Heaviside functions Hu and Hs indicate the unsaturated and saturated phases, respectively. The M2 energy is also associated with an additional eigenmode that arises for a moist atmosphere but not a dry atmosphere. Both the Boussinesq and anelastic equations are examined, and similar energy decompositions are shown in both cases, although the anelastic energy is not quadratic. Extensions that include cloud microphysics are also discussed, such as the Kessler warm-rain scheme. As an application, empirical orthogonal function (EOF) analysis is considered, using a piecewise quadratic moist energy as a weighted energy in contrast to the standard L2 energy. By incorporating information about phase changes into the energy, the leading EOF modes become fundamentally different and capture the variability of the cloud layer rather than the dry subcloud layer.
Model-Based Probable Maximum Precipitation Estimation: How to Estimate the Worst-Case Scenario Induced by Atmospheric Rivers?
Authors: Toride Kinya , Iseri Yoshihiko , Warner Michael D. , Frans Chris D. , Duren Angela M. , England John F. , Kavvas M. Levent
Published: September 2019

The concept of probable maximum precipitation (PMP) is widely used for the design and risk assessment of water resource infrastructure. Despite its importance, past attempts to estimate PMP have not investigated the realism of design maximum storms from a meteorological perspective. This study investigates estimating PMP with realistically maximized storms in a Pacific Northwest region dominated by atmospheric rivers (ARs) using numerical weather models (NWMs). The moisture maximization and storm transposition methods used in NWM-based PMP estimates are examined. We use integrated water vapor transport as a criterion to modify water vapor only at the modeling boundary crossing the path of ARs, whereas existing methods maximize relative humidity at all initial/boundary conditions. It is found that saturation of the entire modeling boundaries can produce unrealistic atmospheric conditions and does not necessarily maximize precipitation over a watershed due to storm structure, stability, and topography. The proposed method creates more realistic atmospheric fields and more severe precipitation. The simultaneous optimization of moisture content and location of storms is also considered to rigorously estimate the most extreme precipitation. Among the 20 most severe storms during 1980–2016, the AR event during 5–9 February 1996 produces the largest 72-h basin-average precipitation when maximized with our method (defined as PMP of this study), in which precipitation is intensified by 1.9 times with a 0.7° shift south and a 30% increase in AR moisture. The 24-, 48-, and 72-h PMP estimates are found to be at least 70 mm lower than the Hydrometeorological Reports estimates regardless of duration.
Machine Learning–Based Blending of Satellite and Reanalysis Precipitation Datasets: A Multiregional Tropical Complex Terrain Evaluation
Authors: Ehsan Bhuiyan Md. Abul , Nikolopoulos Efthymios I. , Anagnostou Emmanouil N.
Published: September 2019

This study evaluates a machine learning–based precipitation ensemble technique (MLPET) over three mountainous tropical regions. The technique, based on quantile regression forests, integrates global satellite precipitation datasets from CMORPH, PERSIANN, GSMaP (V6), and 3B42 (V7) and an atmospheric reanalysis precipitation product (EI_GPCC) with daily soil moisture, specific humidity, and terrain elevation datasets. The complex terrain study areas include the Peruvian and Colombian Andes in South America and the Blue Nile in East Africa. Evaluation is performed at a daily time scale and 0.25° spatial resolution based on 13 years (2000–12) of reference rainfall data derived from dense in situ rain gauge networks. The technique is evaluated using K-fold, separately in each region, and leave-one-region-out validation experiments. Comparison of MLPET with the individual satellite and reanalysis precipitation datasets used for the blending and the recent Multi-Source Weighted-Ensemble Precipitation (MSWEP) global precipitation product exhibited improved systematic and random error statistics for all regions. In addition, it is shown that observations are encapsulated well within the ensemble envelope generated by the blending technique.
Wind-Driven Processes Controlling Oceanic Heat Delivery to the Amundsen Sea, Antarctica
Authors: Dotto Tiago S. , Naveira Garabato Alberto C. , Bacon Sheldon , Holland Paul R. , Kimura Satoshi , Firing Yvonne L. , Tsamados Michel , Wåhlin Anna K. , Jenkins Adrian
Published: September 2019

Variability in the heat delivery by Circumpolar Deep Water (CDW) is responsible for modulating the basal melting of the Amundsen Sea ice shelves. However, the mechanisms controlling the CDW inflow to the region’s continental shelf remain little understood. Here, a high-resolution regional model is used to assess the processes governing heat delivery to the Amundsen Sea. The key mechanisms are identified by decomposing CDW temperature variability into two components associated with 1) changes in the depth of isopycnals [heave (HVE)], and 2) changes in the temperature of isopycnals [water mass property changes (WMP)]. In the Dotson–Getz trough, CDW temperature variability is primarily associated with WMP. The deeper thermocline and shallower shelf break hinder CDW access to that trough, and CDW inflow is regulated by the uplift of isopycnals at the shelf break—which is itself controlled by wind-driven variations in the speed of an undercurrent flowing eastward along the continental slope. In contrast, CDW temperature variability in the Pine Island–Thwaites trough is mainly linked to HVE. The shallower thermocline and deeper shelf break there permit CDW to persistently access the continental shelf. CDW temperature in the area responds to wind-driven modulation of the water mass on-shelf volume by changes in the rate of inflow across the shelf break and in Ekman pumping-induced vertical displacement of isopycnals within the shelf. The western and eastern Amundsen Sea thus represent distinct regimes, in which wind forcing governs CDW-mediated heat delivery via different dynamics.
Mesoscale to Microscale Simulations over Complex Terrain with the Immersed Boundary Method in the Weather Research and Forecasting Model
Authors: Wiersema David J. , Lundquist Katherine A. , Chow Fotini Katopodes
Published: September 2019

Improvements to the Weather Research and Forecasting (WRF) Model are made to enable multiscale simulations over highly complex terrain with dynamically downscaled boundary conditions from the mesoscale to the microscale. Over steep terrain, the WRF Model develops numerical errors that are due to grid deformation of the terrain-following coordinates. An alternative coordinate system, the immersed boundary method (IBM), has been implemented into WRF, allowing for simulations over highly complex terrain; however, the new coordinate system precluded nesting within mesoscale simulations using WRF’s native terrain-following coordinates. Here, the immersed boundary method and WRF’s grid-nesting framework are modified to seamlessly work together. This improved framework for the first time allows for large-eddy simulation over complex (urban) terrain with IBM to be nested within a typical mesoscale WRF simulation. Simulations of the Joint Urban 2003 field campaign in Oklahoma City, Oklahoma, are performed using a multiscale five-domain nested configuration, spanning horizontal grid resolutions from 6 km to 2 m. These are compared with microscale-only simulations with idealized lateral boundary conditions and with observations of wind speed/direction and SF6 concentrations from a controlled release from intensive observation period 3. The multiscale simulation, which is configured independent of local observations, shows similar model skill predicting wind speed/direction and improved skill predicting SF6 concentrations when compared with the idealized simulations, which require use of observations to set mean flow conditions. Use of this improved multiscale framework shows promise for enabling large-eddy simulation over highly complex terrain with dynamically downscaled boundary conditions from mesoscale models.
A Case Study of Terrain Influences on Upscale Convective Growth of a Supercell
Authors: Mulholland Jake P. , Nesbitt Stephen W. , Trapp Robert J.
Published: September 2019

Satellite- and ground-based radar observations have shown that the northern half of Argentina, South America, is a region susceptible to rapid upscale growth of deep moist convection into larger organized mesoscale convective systems (MCSs). In particular, the complex terrain of the Sierras de Córdoba is hypothesized to be vital to this upscale-growth process. A canonical orographic supercell-to-MCS transition case study was analyzed to determine the influence that complex terrain had on processes governing upscale convective growth. High-resolution numerical modeling experiments were conducted in which the terrain height of the Sierras de Córdoba was systematically modified by raising or lowering the elevation of terrain above 1000 m. The alteration of the terrain lead to both direct and indirect effects on storm morphology. A direct effect included terrain blocking of cold pools, whereas indirect effects included terrain-induced variations in pertinent storm environmental parameters (e.g., vertical wind shear, convective available potential energy). When the terrain was raised, low-level and deep-layer vertical wind shear increased, mixed-layer convective available potential energy decreased, deep moist convection initiated earlier, and cold pools were blocked and generally became stronger and deeper. The reverse occurred when the terrain was lowered, resulting in a weaker supercell that did not grow upscale into an MCS. The control simulation supercell displayed the deepest cold pool and correspondingly fastest transition from supercell to MCS, potentially revealing that the unique terrain configuration of the Sierras de Córdoba was supportive of the observed rapid upscale convective growth of this orographic supercell.
A New Path for U.S. Climate Politics: Choosing Policies That Mobilize Business for Decarbonization
Authors: Meckling Jonas
Published: September 2019

What policies could mobilize business support for progressive and durable national climate policy in the United States? I examine the climate policy experiences of U.S. states and propose that a national clean energy standard combined with carefully allocated public investment in clean energy infrastructure and innovation could mobilize economic interests in support of decarbonization. Further, I argue that the more entrenched clean energy and infrastructure become, the more likely it becomes that comprehensive climate policies can be passed in the future. This includes performance and deployment mandates beyond the electricity industry, including in the transport and building sectors. These initial steps may also help to build a winning coalition for progressive federal carbon pricing, as opposed to an accommodative coalition in support of weak carbon pricing.
Repair of the Protruding Lobule
Authors: Raunig Hermann , Hamilton Grant S.
Published: September 2019

Background:

In this paper, the author describes a novel step-by-step setback procedure for correcting protruding lobules; the success of correcting protruding lobules depends on the nature and severity of the auricular lobule deformity. Although the auricular lobules occupy small areas on either side of the head, protruding or misshapen lobules exert a significant and sometimes exaggerated disfiguring influence on the otherwise aesthetically pleasing appearance of the ears. Because the lobule is a soft structure without a cartilage skeleton, the correction of a protruding ear and lobule is always a challenge.

Methods:

Protruding lobule abnormalities stem from deformities of the cauda helicis (cartilaginous helical tail) of the auricular lobule, soft tissue, and/or a shortage of anterior skin; however, the abnormalities are usually a combination of all of the above. Therefore, surgical procedures should address all of the causes of lobule deformity and preserve as much tissue and blood supply as possible. Achieving a successful intervention depends on reducing the tension that affects the entire lobule.

Results:

This is a retrospective analysis of 660 patients who had otoplasty performed by the first author between January 2010 and December 2017. Correction of the ear lobule was needed in 398 (60.3%) patients. Of these, 44.6% patients were male, 55.4% female and the average age was 9 years (range 4-18 years). In this patient cohort, 356 (89.4%) required bilateral and 42 (10.5%) unilateral ear lobule correction. Standardized pre- and postoperative images were recorded for each patient.

Conclusion:

The goal of a setback procedure is a natural and harmonious auricular lobule appearance that is achieved through simple, optimal surgery that addresses all of the features of the auricular anatomy.
Unmet Respite Needs of Children With Medical Technology Dependence
Authors: Sobotka Sarah A. , Lynch Emma , Quinn Michael T. , Awadalla Saria S. , Agrawal Rishi K. , Peek Monica E.
Published: September 2019

Children with medical technology dependency (MTD) require a medical device to compensate for a vital body function and substantial nursing care. As such, they require constant high-level supervision. Respite care provides caregivers with a temporary break, and is associated with reduced stress; however, there are often barriers. The study utilizes mixed methodology with the National Survey of Children with Special Health Care Needs (NS-CSHCN) and semistructured interviews with state-wide care coordinators to understand the gap for respite care services. Fifty-nine percent of parents who needed respite care received none. Parents of older children with MTD were more likely to report respite needs. Care coordinators described that home health shortages created barriers to respite care utilization, and the lack of respite care can lead to hospital readmission. Although respite care is a vital resource to support families of children with MTD, it is infrequently available, which can have severe consequences.
Exploring Trust in Self-Driving Vehicles Through Text Analysis
Authors: Lee John D. , Kolodge Kristin
Published: September 2019

Objective

This study examined attitudes toward self-driving vehicles and the factors motivating those attitudes.

Background

Self-driving vehicles represent potentially transformative technology, but achieving this potential depends on consumers’ attitudes. Ratings from surveys estimate these attitudes, and open-ended comments provide an opportunity to understand their basis.

Method

A nationally representative sample of 7,947 drivers in 2016 and 8,517 drivers in 2017 completed the J.D. Power U.S. Tech Choice StudySM, which included a rating for level of trust with self-driving vehicles and associated open-ended comments. These open-ended comments are qualitative data that can be analyzed quantitatively using structural topic modeling. Structural topic modeling identifies common themes, extracts prototypical comments for each theme, and assesses how the survey year and rating affect the prevalence of these themes.

Results

Structural topic modeling identified 13 topics, such as “Tested for a long time,” which was strongly associated with positive ratings, and “Hacking & glitches,” which was strongly associated with negative ratings. The topics of “Self-driving accidents” and “Trust when mature” were more prominent in 2017 compared with 2016.

Conclusion

Structural topic modeling reveals reasons underlying consumer attitudes toward vehicle automation. These reasons align with elements typically associated with trust in automation, as well as elements that mediate perceived risk, such as the desire for control as well as societal, relational, and experiential bases of trust.

Application

The analysis informs the debate concerning how safe is safe enough for automated vehicles and provides initial indicators of what makes such vehicles feel safe and trusted.
Single-walled carbon nanotubes–polyaniline composites: Synthesis and field-emission analysis
Authors: Ansari Nagma , Shumaila  , Lone Mohd Yaseen , Ali Javid , Husain M , Husain Samina
Published: September 2019

In this article, we report a facile synthesis and comparative analysis of field emission behavior of polyaniline (PANI)-coated as-received and annealed single-walled carbon nanotube (SWCNT) films by in-situ polymerization and ex-situ synthesis routes, respectively. Amongst all the samples, the sample prepared by in-situ polymerization method with more fraction of annealed SWCNTs in the composite gave an enhanced field emission characteristics with E to = 3 V/μm and β = 1.2 × 104 probably because of good formation of pi-pi non-covalent bonds between the SWCNTs and PANI represented by pi-pi interaction between the quinoid rings of PANI and π bond of the SWCNTs lattice. A significant increase in the threshold field is observed after annealing and doping of nanocomposite films. Field emission behavior of as-prepared nanocomposite samples are also analyzed and discussed with two PANI forms: micro-PANI particles and PANI nanofibers. It is also speculated that PANI may have helped in lowering the overall work function of the composite structure which gave an enhanced field emission. The stability of all the samples are also presented and it is analyzed that nanocomposite sample films synthesized by in-situ polymerization method showed a stability for at least 8 h. The surface morphology analysis by field emission scanning electron microscopy of nanocomposite sample films reveal an increase in SWCNTs diameter upon PANI wrapping. The high-resolution transmission electron microscopy and Raman spectra and X-ray diffraction analysis are also presented.
Does Watching This Make Me Feel Ashamed or Angry? An Examination of Latino Americans’ Responses to Immigration Coverage
Authors: Figueroa-Caballero Andrea , Mastro Dana
Published: September 2019

Content analyses of U.S. English-language news coverage of immigration indicate that these stories are laden with negative, threatening messages and have an almost exclusive focus on Latino immigrants. However, little is known regarding how non-immigrant Latinos process and interpret these messages. The current survey of adult non-immigrant Latinos living in the United States addresses this question by applying insights from the rejection-identification model and research on vicarious shame. Based on this research, experiencing group shame in response to immigration news should drive Latinos to distance themselves from this identity, leading to greater affiliation with American identity (to maintain a positive self-concept) and stronger support for restrictive immigration policies (to mitigate the potential threats). Alternatively, experiencing anger in response to this coverage should result in less distancing from the shared Latino identity (i.e., greater affiliation), prompting decreased association with American identity and less support for restrictive immigration policies. Results from the mediation model tested here found support for predictions stemming from both vicarious shame and rejection-identification assumptions, indicating that they represent distinct pathways to views on immigration attitudes and identity management. Furthermore, in line with social identity theory, Mexican Americans (vs. non-Mexican Latinos) were more likely to distance from the immigration message and perceive immigration coverage to depict negative beliefs others hold about their ethnic group (owing to the disproportionate emphasis on Mexicans in this coverage). Results are discussed in terms of the implications for group standing as well as the importance of legitimacy of media messages in this context.
Unpacking commercial gentrification in central Paris
Authors: Bantman-Masum Eve
Published: September 2019

This article documents the complex course of commercial upgrading in four neighbourhoods of central Paris, a slow process in which transnational flows and state intervention play an outsized role. The data was collected at 20 independent coffee shops located in the West 11th district and supplemented by long-term observation of the business mix evolution. The article focuses on the impact of geographic mobility – including migration and residential tourism – in the rapid development of upmarket alternatives to French cafes and bistros. It goes on to explain how political intervention/deregulation facilitated capital investment in commercial real estate. It then discusses the culturally informed perceptions that helped define desirable forms of consumption for France. The article demonstrates the extent to which cross-border flows influenced commercial gentrification, and calls for further research into the complex interplay of local, transnational, private and public forces driving urban change.
The Citation Practices of the High Court of Australia, 1905–2015
Authors: Smyth Russell , Nielsen Ingrid
Published: September 2019

We provide an empirical study of the High Court’s citation to case law and secondary sources at decade intervals between 1905 and 2015. We document trends in the number and type of citations over time, both for the Court as a whole and for the individual Justices. We find that in each of the sample years between 1905 and 1975, the Court cited relatively few authorities and for most of this period the majority of citations were to the Court’s own previous decisions or to decisions of the English courts. However, over the last four sample years—1985, 1995, 2005 and 2015—the Court cited more authority. The Court cited an increasing proportion of its own previous decisions over this period as well as a higher proportion of authority from a more diverse range of sources, including secondary sources, largely at the expense of citations to English cases. We conclude that this reflects the emergence of a distinct Australian common law with the High Court as its final arbitrator.
A parametric study to numerically analyze the formation damage effect
Authors: Davarpanah Afshin , Mirshekari Behnam , Razmjoo Armin
Published: September 2019

Spontaneous countercurrent imbibition is one of the essential parameters in the study of formation damage effect in hydrocarbon reservoirs when the drilling fluid is contacted with the drilled formation. Formation damage is considered as one of the harmful phenomena which would seriously affect the efficiency of drilling performances. In this paper, a numerical model was proposed to analyze the main parameters which have profoundly impacted the formation damage. Based on the following parameters of porosity, permeability, water saturation, oil viscosity, pressure drop, contact time, and capillary pressure which were performed in the proposed model, the dominant influence of each parameter was evaluated in more detail. Regarding the high expenditures of scanning electron microscopy and CT scan in petroleum industries, the proposed analytical model would be beneficial instead of spending vast expenditures of experimental evaluation. Subsequently, to provide the accuracy of the model, a set of experimental CT scan data were used to validate the proposed model, and according to the results of this study, it is evident that the proposed model results are in a good agreement with the laboratory data.
Private Pension Systems Built on Precarious Foundations: A Cohort Study of Labor-Force Trajectories in Chile
Authors: Madero-Cabib Ignacio , Biehl Andres , Sehnbruch Kirsten , Calvo Esteban , Bertranou Fabio
Published: September 2019

The success of private pension systems to provide old-age security is mainly a function of continuous individual pension contributions linked to formal employment. Using a rich longitudinal dataset from Chile and employing sequence analysis, this study examines the pension contribution histories and formal employment pathways of a cohort of individuals who began their working lives simultaneously to the introduction of the Chilean private pension system in the early 1980s, which pioneered private-oriented pension reforms worldwide. Results show that more than half of the individuals from this cohort developed labor-force trajectories inconsistent with continuous pension contributions and formal employment, which particularly affects women and lower educated people. We conclude that policy and decision makers focused on aging topics should be aware of the increasing diversity and precariousness of labor-force trajectories when evaluating the performance and sustainability of both private and public pension regimes.
Democratic disillusionment? Desire for democracy after the Arab uprisings
Authors: Spierings Niels
Published: September 2019

Have the Arab uprisings influenced the desire for democracy in the Middle East and North Africa? This study presents a systematic explanation of the different impact the uprisings had on people’s desire for democracy across the region. It applies the relatively new consequence-based theory of democratic attitudes, and integrates the notion of deprivation into it. The expectations derived from this framework are tested empirically by examining data from 45 public opinion surveys in 11 Middle East and North Africa countries (2001–2014) and combining them with a systematic country-level case comparison. The study shows that the desire for democracy drops mainly in countries of major protest and initial political liberalization, but no substantial democratization (e.g. Egypt, Morocco) indeed, and that a lack of major protest or initial reform (e.g. Algeria, Yemen) ‘prevents’ disillusionment. The seemingly exceptional Lebanese and Tunisian cases also show the mechanism holds for specific groups in society: Lebanese Sunnis and the poorest Tunisians.
Meeting the educational needs of a gifted child: A parent’s narrative
Authors: Manasawala SA , Desai DN
Published: September 2019

India is currently focusing on providing education for all, and special population like the gifted is being neglected. This is evident in the case of Aditya (IQ 145), a 7-year-old boy, and his parents who after discovering that their child is gifted attempt to meet his unique educational needs. Despite evidence of Aditya qualifying in examination two grades above his age level, the school authorities neither offer acceleration nor provide appropriate resources. This study attempts to delineate the importance of combined efforts of parent, school, and the community in nurturing gifted children. Finally, the researcher makes a few recommendations for parents: (i) create support groups to share parenting experiences; (ii) explore online and local learning resources to educate themselves about giftedness and nurture their children; and (iii) identify mentors in the community or other parents who can support in meeting the educational needs of these children.
Economic Transformations in a Savara Village of Andhra Pradesh: Tamarind to Cashew
Authors: Sharma Bhallamudi V.
Published: September 2019

Even tribal communities in India living in relative geographic isolation have experienced significant transformations during the last 70 years. Many studies have investigated the impact of tribal development programmes on the socio-economic conditions of different tribal communities. However, few attempts to systematically re-study the same tribal village after some decades have been made. This article re-examines the transformation of different sources of income for a Savara village in Andhra Pradesh and specifically scrutinises the impact of cashew plantations promoted in 1983–5. Since the acceptance to undertake cashew plantation was a precondition for the Savara of Manapuram to achieve economic and language integration, the question becomes what have been the results after some decades. The article identifies many consequences for this community, not just a shift from tamarind to cashew.
Choroid plexus perfusion and intracranial cerebrospinal fluid changes after angiogenesis
Authors: Johnson Skylar E , McKnight Colin D , Lants Sarah K , Juttukonda Meher R , Fusco Matthew , Chitale Rohan , Donahue Paula C , Claassen Daniel O , Donahue Manus J
Published: September 2019

Recent studies have provided evidence that cortical brain ischemia may influence choroid plexus function, and such communication may be mediated by either traditional CSF circulation pathways and/or a possible glymphatic pathway. Here we investigated the hypothesis that improvements in arterial health following neoangiogenesis alter (i) intracranial CSF volume and (ii) choroid plexus perfusion in humans. CSF and tissue volume measurements were obtained from T1-weighted MRI, and cortical and choroid plexus perfusion were obtained from perfusion-weighted arterial spin labeling MRI, in patients with non-atherosclerotic intracranial stenosis (e.g. Moyamoya). Measurements were repeated after indirect surgical revascularization, which elicits cortical neoangiogenesis near the revascularization site ( n = 23; age = 41.8 ± 13.4 years), or in a cohort of participants at two time points without interval surgeries ( n = 10; age = 41.7 ± 10.7 years). Regression analyses were used to evaluate dependence of perfusion and volume on state (time 1 vs. 2). Post-surgery, neither CSF nor tissue volumes changed significantly. In surgical patients, cortical perfusion increased and choroid plexus perfusion decreased after surgery; in participants without surgeries, cortical perfusion reduced and choroid plexus perfusion increased between time points. Findings are discussed in the context of a homeostatic mechanism, whereby arterial health, paravascular flow, and/or ischemia can affect choroid plexus perfusion.
Quantification of cerebral blood flow in adults by contrast-enhanced near-infrared spectroscopy: Validation against MRI
Authors: Milej Daniel , He Lian , Abdalmalak Androu , Baker Wesley B , Anazodo Udunna C , Diop Mamadou , Dolui Sudipto , Kavuri Venkaiah C , Pavlosky William , Wang Lin , Balu Ramani , Detre John A , Amendolia Olivia , Quattrone Francis , Kofke W Andrew , Yodh Arjun G , St Lawrence Keith
Published: September 2019

The purpose of this study was to assess the accuracy of absolute cerebral blood flow (CBF) measurements obtained by dynamic contrast-enhanced (DCE) near-infrared spectroscopy (NIRS) using indocyanine green as a perfusion contrast agent. For validation, CBF was measured independently using the MRI perfusion method arterial spin labeling (ASL). Data were acquired at two sites and under two flow conditions (normocapnia and hypercapnia). Depth sensitivity was enhanced using time-resolved detection, which was demonstrated in a separate set of experiments using a tourniquet to temporally impede scalp blood flow. A strong correlation between CBF measurements from ASL and DCE-NIRS was observed (slope = 0.99 ± 0.08, y-intercept = −1.7 ± 7.4 mL/100 g/min, and R2 = 0.88). Mean difference between the two techniques was 1.9 mL/100 g/min (95% confidence interval ranged from −15 to 19 mL/100g/min and the mean ASL CBF was 75.4 mL/100 g/min). Error analysis showed that structural information and baseline absorption coefficient were needed for optimal CBF reconstruction with DCE-NIRS. This study demonstrated that DCE-NIRS is sensitive to blood flow in the adult brain and can provide accurate CBF measurements with the appropriate modeling techniques.
Cerebrovascular effects of endothelin-1 investigated using high-resolution magnetic resonance imaging in healthy volunteers
Authors: Hougaard Anders , Younis Samaira , Iljazi Afrim , Haanes Kristian A , Lindberg Ulrich , Vestergaard Mark B , Amin Faisal M , Sugimoto Kazutaka , Kruse Lars S , Ayata Cenk , Ashina Messoud
Published: September 2019

Endothelin-1 (ET-1) is a highly potent vasoconstrictor peptide released from vascular endothelium. ET-1 plays a major role in cerebrovascular disorders and likely worsens the outcome of acute ischaemic stroke and aneurismal subarachnoid haemorrhage through vasoconstriction and cerebral blood flow (CBF) reduction. Disorders that increase the risk of stroke, including hypertension, diabetes mellitus, and acute myocardial infarction, are associated with increased plasma levels of ET-1. The in vivo human cerebrovascular effects of systemic ET-1 infusion have not previously been investigated. In a two-way crossover, randomized, double-blind design, we used advanced 3 tesla MRI methods to investigate the effects of high-dose intravenous ET-1 on intra- and extracranial artery circumferences, global and regional CBF, and cerebral metabolic rate of oxygen (CMRO2) in 14 healthy volunteers. Following ET-1 infusion, we observed a 14% increase of mean arterial blood pressure, a 5% decrease of middle cerebral artery (MCA) circumference, but no effects on extracerebral arteries and no effects on CBF or CMRO2. Collectively, the findings indicate MCA constriction secondarily to blood pressure increase and not due to a direct vasoconstrictor effect of ET-1. We suggest that, as opposed to ET-1 in the subarachnoid space, intravascular ET-1 does not exert direct cerebrovascular effects in humans.
General-purpose incremental covariance update and efficient belief space planning via a factor-graph propagation action tree
Authors: Kopitkov Dmitry , Indelman Vadim
Published: September 2019

Fast covariance calculation is required both for simultaneous localization and mapping (SLAM; e.g., in order to solve data association) and for evaluating the information-theoretic term for different candidate actions in belief space planning (BSP). In this article, we make two primary contributions. First, we develop a novel general-purpose incremental covariance update technique, which efficiently recovers specific covariance entries after any change in probabilistic inference, such as the introduction of new observations/variables or relinearization. Our approach is shown to recover them faster than other state-of-the-art methods. Second, we present a computationally efficient approach for BSP in high-dimensional state spaces, leveraging our incremental covariance update method. State-of-the-art BSP approaches perform belief propagation for each candidate action and then evaluate an objective function that typically includes an information-theoretic term, such as entropy or information gain. Yet, candidate actions often have similar parts (e.g., common trajectory parts), which are however evaluated separately for each candidate. Moreover, calculating the information-theoretic term involves a costly determinant computation of the entire information (covariance) matrix, which is [Formula: see text] with [Formula: see text] being dimension of the state or costly Schur complement operations if only marginal posterior covariance of certain variables is of interest. Our approach, rAMDL-Tree, extends our previous BSP method rAMDL, by exploiting incremental covariance calculation and performing calculation reuse between common parts of non-myopic candidate actions, such that these parts are evaluated only once, in contrast to existing approaches. To that end, we represent all candidate actions together in a single unified graphical model, which we introduce and call a factor-graph propagation (FGP) action tree. Each arrow (edge) of the FGP action tree represents a sub-action of one (or more) candidate action sequence(s) and in order to evaluate its information impact we require specific covariance entries of an intermediate belief represented by the tree’s vertex from which the edge is coming out (e.g., tail of the arrow). Overall, our approach has only a one-time calculation that depends on [Formula: see text], while evaluating action impact does not depend on [Formula: see text]. We perform a careful examination of our approaches in simulation, considering the problem of autonomous navigation in unknown environments, where rAMDL-Tree shows superior performance compared with rAMDL, while determining the same best actions.
A phase II trial of cabazitaxel as second line chemotherapy in relapsed locally advanced and/or metastatic carcinoma of the penis
Authors: Challapalli Amarnath , Pearson Sylvia , Mitra Anita V. , Coe Marc , Thomson Alastair , Elliott Tony , Kirkbride Peter , Pickering Lisa , Kirk Hannah , Foulstone Emily , Evans Heidi , Bravo Alicia , Bahl Amit K.
Published: September 2019

Objectives

To assess the efficacy and tolerability of cabazitaxel in relapsed penile cancer.

Methods

This Phase II single-arm trial was designed to recruit 17 patients with relapsed penile cancer. The primary endpoint was objective (complete + partial) response rate (ORR; Response Evaluation Criteria in Solid Tumours [RECIST] v1.1). Treatment comprised six 21-day cycles of cabazitaxel with restaging after cycles 2 and 4. The planned interim analysis was based upon the premise that if none of the first nine patients achieved ORR, trial would be stopped (α = 0.05, Simon’s 2-stage design).

Results

Nine patients were recruited from four UK centres between December 2014 and August 2016. The median age was 61 (range, 27–73.6) years, and seven patients had metastases. Patients received a median of two chemotherapy cycles (range, 2–5). None of the nine patients achieved ORR and the trial was stopped. Cabazitaxel was well tolerated with no dose reductions or delays. Three patients had grade 3/4 adverse events (anaemia, vomiting, or neutropenic sepsis). The median progression-free and overall survival were 1.3 and 5.6 months, respectively.

Conclusions

The trial did not reach the threshold for further continuation of single-agent cabazitaxel. However, the observed tolerability profile supports its further investigation in combination with other agents to improve patient outcomes.
Nonalcoholic Wernicke’s encephalopathy: a retrospective study of 17 cases
Authors: Yin Hongzhen , Xu Qiancheng , Cao Yingya , Qi Yupeng , Yu Tao , Lu Weihua
Published: September 2019

Objective

Nonalcoholic Wernicke’s encephalopathy (WE) is a devastating neuropsychiatric syndrome caused by thiamine deficiency. Although many case reports on WE have been published, more studies are required to guide the diagnosis and treatment of nonalcoholic WE.

Methods

We retrospectively studied patients who were diagnosed with WE in our hospital. Data on demographics, possible causes, phenomenology, and diagnostic and treatment delays were abstracted from medical records by chart reviews.

Results

Seventeen patients were diagnosed with nonalcoholic WE. Nonalcoholic WE had many causes, such as gastrointestinal surgery, gastrointestinal tract diseases, vomiting, and psychiatric diseases. Most patients presented with abnormal mental symptoms, including those in a coma.

Conclusion

In summary, we recommend using operational criteria to diagnose and treat nonalcoholic WE as early as possible to avoid misdiagnosis and treatment delays. Nonalcoholic WE remains a clinical diagnosis, and certain examinations are helpful for this diagnosis, such as measuring serum thiamine concentrations. We should focus on patients who present with abnormal mental symptoms, even those in a coma, and administer parenteral thiamine before any carbohydrate to reduce the high frequency of residual morbidity.
Outcomes of Revision Hip Arthroscopic Surgery: A Systematic Review and Meta-analysis
Authors: O’Connor Michaela , Steinl Gabrielle K. , Padaki Ajay S. , Duchman Kyle R. , Westermann Robert W. , Lynch T. Sean
Published: September 2019

Background:

While the indications for primary hip arthroscopic surgery in treating femoroacetabular abnormalities continue to be defined, the indications and outcomes for revision hip arthroscopic surgery remain ambiguous. However, revision hip arthroscopic surgery is performed in 5% to 14% of patients after their index procedure. While patient-reported outcomes (PROs) generally improve after revision procedures, the extent of their improvement is not well defined.

Purpose:

To determine the outcomes and efficacy of revision hip arthroscopic surgery in patients who remain symptomatic after their index procedure.

Study Design:

Meta-analysis and systematic review.

Methods:

The terms “hip arthroscopy,”“revisions,”“outcomes,” and “femoroacetabular impingement” were searched in PubMed, Web of Science, Scopus, Cochrane Library, and Google Scholar. After screening, 15 studies were included for review. In addition to hip-specific metrics, functional outcome measures were included. Pooled estimates and 95% CIs were calculated using inverse variance methods.

Results:

A total of 4765 hips in 4316 patients were identified. The most common indication for revision surgery was inadequate bony resection during the index procedure. Meta-analysis showed that all PROs improved significantly from baseline to final follow-up after revision hip arthroscopic surgery. Notably, the modified Harris Hip Score (mHHS) increased a mean of 17.20 points after revision hip arthroscopic surgery, the Hip Outcome Score–Activities of Daily Living (HOS-ADL) improved by 13.98, and the visual analog scale (VAS) for pain decreased by 3.16. However, when compared with primary hip arthroscopic surgery, the mean PRO scores after revision hip arthroscopic surgery were lower. After revision hip arthroscopic surgery, the rates of conversion to total hip arthroplasty ranged from 0% to 14.3%, and the rates of further arthroscopic revision ranged from 2% to 14%.

Conclusion:

Inadequate bony resection represents the most common indication for revision hip arthroscopic surgery. PROs improve significantly after revision hip arthroscopic surgery but remain lower than those of patients undergoing primary hip arthroscopic surgery.
Extracorporeal Shockwave Therapy Accelerates the Healing of a Meniscal Tear in the Avascular Region in a Rat Model
Authors: Hashimoto Shogo , Ichinose Tsuyoshi , Ohsawa Takashi , Koibuchi Noriyuki , Chikuda Hirotaka
Published: September 2019

Background:

The treatment of meniscal tears in the avascular region remains a clinical challenge. Extracorporeal shockwave therapy (ESWT) is a minimally invasive, safe, and effective therapy for various orthopaedic disorders. However, the therapeutic effect of ESWT on meniscal tears has not been reported.

Purpose:

To evaluate the therapeutic effect of ESWT in the treatment of meniscal tears.

Study Design:

Controlled laboratory study.

Methods:

Twelve-week-old male Wistar rats were divided into 3 groups (normal, ESWT–, and ESWT+). The authors made a full-thickness 2-mm longitudinal tear in the avascular region of the anterior horn in the latter 2 groups. At 1 week after surgery, the ESWT+ group received 800 impulses of shockwave at 0.22-mJ/mm2 energy flux density in a single session. The authors performed a histological examination to evaluate meniscal healing (n = 10 for each group) and immunohistochemistry to analyze the expression of bromodeoxyuridine (BrdU; n = 5 for each group) and CCN family member 2/connective tissue growth factor (CCN2/CTGF; n = 5 for each group) at 2, 4, and 8 weeks after ESWT. The mRNA levels of CCN2, SOX 9, VEGF-a, aggrecan, Col1a2, and Col2a1 at the site of the meniscal tear at 4 weeks after ESWT were quantitatively evaluated by a real-time polymerase chain reaction (n = 5 for each group).

Results:

The meniscus healing scores in the ESWT+ group were significantly higher than those in the ESWT– group at 4 weeks and 8 weeks. The ratio of BrdU-positive cells was the highest in the ESWT+ group at all observation periods. The ratio of CCN2-positive cells was highest in the ESWT+ group at 4 and 8 weeks. In the ESWT+ group, real-time polymerase chain reaction revealed that the levels of CCN2, SOX9, aggrecan, and Col2a1 were upregulated (All significant data were P < .05).

Conclusion:

ESWT promoted the healing of meniscal tears in the avascular area. ESWT stimulated proliferation of meniscal cells and the upregulation of cartilage-repairing factors such as CCN2, with the upregulation of cartilage-specific extracellular matrix expression.

Clinical Relevance:

ESWT may be an effective therapeutic option that promotes meniscal healing in the avascular region.
Donor Site Evaluation After Osteochondral Autograft Transplantation for Capitellar Osteochondritis Dissecans
Authors: Matsuura Takeshi , Hashimoto Yusuke , Kinoshita Takuya , Nishino Kazuya , Nishida Yohei , Takigami Junsei , Katsuda Hiroshi , Shimada Nagakazu
Published: September 2019

Background:

Osteochondral autograft transplantation (OAT) for capitellar osteochondritis dissecans (OCD) requires harvesting of tissue from the asymptomatic knee joint. However, donor site morbidity (DSM) in such cases remains unclear.

Purpose:

To evaluate DSM and postoperative radiographic findings in patients undergoing OAT for advanced capitellar OCD.

Study Design:

Case series; Level of evidence, 4.

Methods:

Eighty-six juvenile athletes underwent OAT for advanced capitellar OCD. The 2000 International Knee Documentation Committee subjective score, rate of return to sports, and symptoms in the donor knee were assessed at a mean follow-up of 86 months (range, 28-185 months). Additionally, 49 of the 86 patients were assessed by radiographic and magnetic resonance imaging (MRI) findings of the knee donor site. DSM was defined according to the usual criterion (persistent symptoms for >1 year or the need for subsequent intervention) and a stricter criterion (the presence of any symptoms, such as effusion, patellofemoral complaints, crepitation, unspecified disturbance, stiffness, pain/instability during activities, and osteoarthritic change). The stricter criterion was also used to allocate patients into a DSM group and a no-DSM group.

Results:

Two and 11 patients were determined to have DSM according to the usual and stricter criteria, respectively. All patients returned to the competitive level of their sports. The mean International Knee Documentation Committee score was 99.0. MRI findings showed abnormal signal intensity in 17 patients (35%) and hypertrophic changes in 11 patients (22%) at the donor harvest sites. The MOCART (magnetic resonance observation of cartilage repair tissue) score was higher in the no-DSM group (mean, 68.2) than in the DSM group (mean, 52.9) ( P = .027).

Conclusion:

OAT for juvenile athletes with advanced capitellar OCD provided good clinical outcomes. The DSM rate was relatively low (2.3%) with the usual criterion but high (12.8%) with the stricter criterion. MRI showed an abnormal signal intensity and hypertrophy in some cases.