bluuebunny/crossref_metadata_2025 huggingface dataset:
A Learning Framework for Winner-Take-All Networks with Stochastic Synapses
Authors: Mostafa Hesham , Cauwenberghs Gert
Published: April 2018

Many recent generative models make use of neural networks to transform the probability distribution of a simple low-dimensional noise process into the complex distribution of the data. This raises the question of whether biological networks operate along similar principles to implement a probabilistic model of the environment through transformations of intrinsic noise processes. The intrinsic neural and synaptic noise processes in biological networks, however, are quite different from the noise processes used in current abstract generative networks. This, together with the discrete nature of spikes and local circuit interactions among the neurons, raises several difficulties when using recent generative modeling frameworks to train biologically motivated models. In this letter, we show that a biologically motivated model based on multilayer winner-take-all circuits and stochastic synapses admits an approximate analytical description. This allows us to use the proposed networks in a variational learning setting where stochastic backpropagation is used to optimize a lower bound on the data log likelihood, thereby learning a generative model of the data. We illustrate the generality of the proposed networks and learning technique by using them in a structured output prediction task and a semisupervised learning task. Our results extend the domain of application of modern stochastic network architectures to networks where synaptic transmission failure is the principal noise mechanism.
A Theory of Sequence Indexing and Working Memory in Recurrent Neural Networks
Authors: Frady E. Paxon , Kleyko Denis , Sommer Friedrich T.
Published: April 2018

To accommodate structured approaches of neural computation, we propose a class of recurrent neural networks for indexing and storing sequences of symbols or analog data vectors. These networks with randomized input weights and orthogonal recurrent weights implement coding principles previously described in vector symbolic architectures (VSA) and leverage properties of reservoir computing. In general, the storage in reservoir computing is lossy, and crosstalk noise limits the retrieval accuracy and information capacity. A novel theory to optimize memory performance in such networks is presented and compared with simulation experiments. The theory describes linear readout of analog data and readout with winner-take-all error correction of symbolic data as proposed in VSA models. We find that diverse VSA models from the literature have universal performance properties, which are superior to what previous analyses predicted. Further, we propose novel VSA models with the statistically optimal Wiener filter in the readout that exhibit much higher information capacity, in particular for storing analog data.

The theory we present also applies to memory buffers, networks with gradual forgetting, which can operate on infinite data streams without memory overflow. Interestingly, we find that different forgetting mechanisms, such as attenuating recurrent weights or neural nonlinearities, produce very similar behavior if the forgetting time constants are matched. Such models exhibit extensive capacity when their forgetting time constant is optimized for given noise conditions and network size. These results enable the design of new types of VSA models for the online processing of data streams.
A Computational Account of the Role of Cochlear Nucleus and Inferior Colliculus in Stabilizing Auditory Nerve Firing for Auditory Category Learning
Authors: Higgins Irina , Stringer Simon , Schnupp Jan
Published: April 2018

It is well known that auditory nerve (AN) fibers overcome bandwidth limitations through the volley principle, a form of multiplexing. What is less well known is that the volley principle introduces a degree of unpredictability into AN neural firing patterns that may be affecting even simple stimulus categorization learning. We use a physiologically grounded, unsupervised spiking neural network model of the auditory brain with spike time dependent plasticity learning to demonstrate that plastic auditory cortex is unable to learn even simple auditory object categories when exposed to the raw AN firing input without subcortical preprocessing. We then demonstrate the importance of nonplastic subcortical preprocessing within the cochlear nucleus and the inferior colliculus for stabilizing and denoising AN responses. Such preprocessing enables the plastic auditory cortex to learn efficient robust representations of the auditory object categories. The biological realism of our model makes it suitable for generating neurophysiologically testable hypotheses.
The Evolution and Impact of a Meteorological Outreach Program for Public Safety Officials: An Update on the Oklahoma Mesonet’s OK-First Program
Authors: Hocker James E. , Melvin Andrea D. , Kloesel Kevin A. , Fiebrich Christopher A. , Hill Robert W. , Smith Richard D. , Piltz Steven F.
Published: April 2018

Since 1997, the Oklahoma Mesonet (the state’s automated mesoscale weather station network) has served a community of more than 1,400 public safety officials (emergency managers, fire officials, law enforcement, etc.) across Oklahoma through a weather data and training program called Oklahoma’s First-Response Information Resource System using Telecommunications (OK-First). OK-First provides free weather and radar data interpretation classes to eligible public safety officials and, following successful completion of training, password-protected access to weather data tools including a website and software. The objective of OK-First when it began was to fill significant gaps in weather product training and data access for Oklahoma’s public safety community. Though the core mission remains the same 20 years later, many aspects of OK-First have evolved over time, including participant membership, training curriculum, formats of training, training requirements, website and software technology, and program feedback. The purpose of this paper is to provide an update on the Mesonet’s OK-First program, with a particular focus on training, tools, and the impact it has had on the public safety community.
Climate Model Assessment of Changes in Winter–Spring Streamflow Timing over North America
Authors: Kam Jonghun , Knutson Thomas R. , Milly P. C. D.
Published: April 2018

Over regions where snowmelt runoff substantially contributes to winter–spring streamflows, warming can accelerate snowmelt and reduce dry-season streamflows. However, conclusive detection of changes and attribution to anthropogenic forcing is hindered by the brevity of observational records, model uncertainty, and uncertainty concerning internal variability. In this study, the detection/attribution of changes in midlatitude North American winter–spring streamflow timing is examined using nine global climate models under multiple forcing scenarios. Robustness across models, start/end dates for trends, and assumptions about internal variability are evaluated. Marginal evidence for an emerging detectable anthropogenic influence (according to four or five of nine models) is found in the north-central United States, where winter–spring streamflows have been starting earlier. Weaker indications of detectable anthropogenic influence (three of nine models) are found in the mountainous western United States/southwestern Canada and in the extreme northeastern United States/Canadian Maritimes. In the former region, a recent shift toward later streamflows has rendered the full-record trend toward earlier streamflows only marginally significant, with possible implications for previously published climate change detection findings for streamflow timing in this region. In the latter region, no forced model shows as large a shift toward earlier streamflow timing as the detectable observed shift. In other (including warm, snow free) regions, observed trends are typically not detectable, although in the U.S. central plains we find detectable delays in streamflow, which are inconsistent with forced model experiments.
Khasi hills and Khasi culture: Reconnection in Kynpham Sing Nongkynrih’s The Yearning of Seeds
Authors: Chakraborty Sayantan
Published: April 2018

This article attempts a post-pastoral reading of Kynpham Sing Nongkynrih’s The Yearning of Seeds through the concept of reconnection in the context of contemporary socio-political and environmental conditions of Meghalaya. The traditional Khasi belief system considers the physical environment as sacred, but at the present time the Khasi Hills are experiencing reckless plundering of natural resources as commodities for consumption. Nongkynrih probes deeply into the present relationship between the Khasi Hills and the Khasi culture, and engages in a complex negotiation with this society and its environment. This negotiation leads to the realization of the need for establishing a renewed relationship between the Khasi Hills and the Khasi culture in the present context of a changing environment and the withering of the traditional culture. A post-pastoral reading of Nongkynrih’s poems exposes the complexity of the negotiation that leads to this realization, of a new sense of Khasi experience and identity.
A multi-target compiler for CML-DEVS
Authors: Cristiá Maximiliano , Hollmann Diego A. , Frydman Claudia
Published: April 2018

Discrete Event System Specification (DEVS) is a modular and hierarchical formalism for system modeling and simulation. DEVS models can be mathematically described; simulation is performed by tools called concrete simulators. Concerning atomic DEVS models, each concrete simulator has its own input language which is, essentially, a general-purpose programming language (such as Java or C++). Hence, once engineers have written the mathematical model, they need to manually translate it into the input language of the concrete simulator of their choice. In this paper we present a multi-target compiler for atomic DEVS models written in CML-DEVS, a mathematics-based DEVS modeling language. This multi-target compiler is able to compile a CML-DEVS model to the input languages of the PowerDEVS and DEVS-Suite concrete simulators. In this way, the CML-DEVS compiler frees engineers from the manual translation of their mathematical models. In fact, the same mathematical model can be simulated on both simulators by simply recompiling the model. The CML-DEVS multi-target compiler can be easily extended to produce code for other concrete simulators.
Bringing the street back in: Considering strategy, contingency and relative good fortune in street children’s access to paid work in Accra
Authors: Mizen Phil
Published: April 2018

A sociology of street children has emerged defined by its rejection of the dominant narratives of child welfare organisations that identify the street as the root cause of children’s immiseration and improper socialisation. In its place, sociological analysis has undermined the value of conceptualising street children as a coherent group on the street and in a parallel move has looked to conceptually reposition street children away from assumptions of passivity and neglect, towards a foundational insistence that the starting place for analysis is the positioning of street children as active and strategic social agents. It is the adequacy of this latter concern that is the focus of this article. By reintroducing the location of children within the social relations of the informal street economy, this article draws upon extensive and long-term qualitative research examining the lives of street children in Accra, Ghana. The argument here is that sociological notions of strategic action and efficacious agency seem ill-suited to accounting for the dilemmas and difficulties that street children’s quests for paid work inevitably involve. Rather, it is relative good fortune within the radical uncertainty of the social relations of the informal street economy that seems much more appropriate to accounting for how these children are integrated into work.
Digital territories: Google maps as a political technique in the re-making of urban informality
Authors: Luque-Ayala Andrés , Neves Maia Flávia
Published: April 2018

This article examines the mobilisation of spatial media technologies for digitally mapping informal settlements. It argues that digital mapping operates politically through a re-configuration of circulation, power, and territorial formations. Drawing on Stuart Elden’s understanding of territory, where space is ‘rendered’ as a political category, the coming together of digital mapping and the geoweb is uncovered as a political technique re-making territory through computational logics – operating as a calculative practice that, beyond simply representing space, is productive of the political spatiality that characterises territory. The article is based on an analysis of recent attempts by ICT corporates, particularly Google, to map favelas in Rio de Janeiro, Brazil, critically examining the claim that digitally mapping informal settlements is a mechanism for socio-economic inclusion. Providing a counterargument to claims around the power of digital maps to incorporate favelas, provide recognition, legitimacy, visibility and citizenship, we discuss how in the interface between digital and urban worlds, territory as a political space is constructed through economic incorporation. In doing so, the article unpacks the spatial politics of digital and smart urbanisms and the emerging sovereignties of digital territories, particularly in the context of the tension between inclusion and exclusion experienced by those who live in informal settlements in cities in the global South.
Caffeine does not affect susceptibility to cortical spreading depolarization in mice
Authors: Yalcin Nilufer , Chen Shih-Pin , Yu Esther S , Liu Tzu-Ting , Yen Jiin-Cherng , Atalay Yahya B , Qin Tao , Celik Furkan , van den Maagdenberg Arn MJM , Moskowitz Michael A , Ayata Cenk , Eikermann-Haerter Katharina
Published: April 2018

Several factors that modulate migraine, a common primary headache disorder, also affect susceptibility to cortical spreading depolarization (CSD). CSD is a wave of neuronal and glial depolarization and thought to underlie the migraine aura and possibly headache. Here, we tested whether caffeine, known to alleviate or trigger headache after acute exposure or chronic use/withdrawal, respectively, modulates CSD. We injected C57BL/6J mice with caffeine (30, 60, or 120 mg/kg; i.p.) once ( acute) or twice per day for one or two weeks ( chronic). Susceptibility to CSD was evaluated by measuring the electrical CSD threshold and by assessing KCl-induced CSD. Simultaneous laser Doppler flowmetry was used to assess CSD-induced cortical blood flow changes. Recordings were performed 15 min after caffeine/vehicle administration, or 24 h after the last dose of chronic caffeine in the withdrawal group. The latter paradigm was also tested in mice carrying the familial hemiplegic migraine type 1 R192Q missense mutation, considered a valid migraine model. Neither acute/chronic administration nor withdrawal of caffeine affected CSD susceptibility or related cortical blood flow changes, either in WT or R192Q mice. Hence, adverse or beneficial effects of caffeine on headache seem unrelated to CSD pathophysiology, consistent with the non-migrainous clinical presentation of caffeine-related headache.
Investigation of Broad Autism Phenotype Traits as Measured by the 26-Item Autism Quotient
Authors: Camodeca Amy , Hosack Alexandra , Todd Kylie Q.
Published: April 2018

The extant literature regarding psychometric properties of measures of subclinical adult autism traits is sparse. The current study investigated the validity and internal consistency reliability of the 26-item Autism Quotient (AQ-26), a self-report measure of autism traits, in a nonclinical young adult sample. Results indicated significantly better model fit with an 18-item measure (AQ-18), with optimal fit indices. Otherwise, AQ-18 and AQ-26 findings were similar and are discussed together. A three-factor model best fit the data. Scores demonstrated similar correlations in expected directions with the Empathy Quotient and Broad Autism Phenotype (BAP) Questionnaire. Expected differences were also observed when college major, gender, and BAP/non-BAP groups were compared. Despite somewhat weaker evidence for the 26/18-Details/Patterns factor, findings indicate that the AQ-26 and AQ-18 are promising measures of the three traits of subclinical autism spectrum symptomatology.
Does Increasing Mobile Device Coverage Reduce Heterogeneity in Completing Web Surveys on Smartphones?
Authors: Gummer Tobias , Quoß Franziska , Roßmann Joss
Published: April 2018

Mobile coverage recently has reached an all-time high, and in most countries, high-speed Internet connections are widely available. Due to technological development, smartphones and tablets have become increasingly popular. Accordingly, we have observed an increasing use of mobile devices to complete web surveys and, hence, survey methodologists have shifted their attention to the challenges that stem from this development. The present study investigated whether the growing use of smartphones has decreased how systematically this choice of device varies between groups of respondents (i.e., how selective smartphone usage for completing web surveys is). We collected a data set of 18,520 respondents from 18 web surveys that were fielded in Germany between 2012 and 2016. Based on these data, we show that while the use of smartphones to complete web surveys has considerably increased over time, selectivity with respect to using this device has remained stable.
An Agent-Based Modeling and Simulation Approach to Commodity Markets
Authors: Giulioni Gianfranco
Published: April 2018

The present work provides an open-source, agent-based behavioral model primarily addressed to the dynamics associated with the commodities spot price formation, as well as variations and contrast patterns belonging to the exchanged quantity. The framework can flexibly be used for several commodities, but it has to be integrated and qualified with the modelization of producers’ and buyers’ behavior when used for the analysis of a specific commodity, stock, or group of merchandise. Due to the fact that various commodities or consumer artifacts are perceived and treated differently in several diverse contexts, the intended tasks or functions are mainly entrusted to those experts in the specific fields, who would find the software tool we designed a good starting point for their investigations. Toward achieving this aim, open-source code is provided along with detailed documentation on how to use, further develop, and enhance the present features of the proposed agent-based modeling and simulation software. This is publicly available at https://github.com/gfgprojects/cms
Input–Output Table for India 2013–2014: Based on the New Series of National Accounts Statistics and Supply and the Use Table
Authors: Singh Kanhaiya , Saluja M.R.
Published: April 2018

In our study, we attempt to produce a more up-to-date input–output (I-O) table for India based on the supply and use table (SUT) of the economy and the new series of National Accounts Statistics (NAS). The resulting table has been used to estimate output multipliers for 25 sectors, and these have been compared with multipliers from the last set of I-O officially estimated for the country in 2007–2008. A key difference between the two sets of tables is the inclusion of inputs in the public administration sector in the more recent one, as a result of which the Type-I multiplier of this sector is greater than one in the latter table compared to one in the former. For the same reason, the Type-II multipliers obtained from the 2013–2014 I-O table are broadly higher than those obtained from the 2007–2008 I-O table. Validation has also been done by comparing gross value added (GVA) as a basic price obtained from the national accounts data for 2013–2014 with the GVA arrived at from the constructed I-O table.

JEL Classification: C-67, E01
Subphenotyping and Classification of Cleft Lip and Alveolus in Adult Unoperated Patients
Authors: Vermeij-Keers Christl , Rozendaal Anna M. , Luijsterburg Antonius J. M. , Latief Benny S. , Lekkas Costas , Kragt Lea , Ongkosuwito Edwin M.
Published: April 2018

Objective:

Previously, a new embryological classification was introduced subdividing oral clefts into fusion and/or differentiation defects. This subdivision was used to classify all subphenotypes of cleft lip with or without alveolus (CL±A). Subsequently, it was investigated whether further morphological grading of incomplete CLs is clinically relevant, and which alveolar part is deficient in fusion/differentiation defects.

Design:

Observational cohort study.

Setting:

Three hundred fifty adult unoperated Indonesian cleft patients presented themselves for operation. Cephalograms, dental casts, and intraoral and extraoral photographs—eligible for the present study—were used to determine morphological severity of CL±A.

Patients:

Patients with unilateral or bilateral clefts of the primary palate only were included.

Main Outcome Measures:

Clefts were classified—according to developmental mechanisms and timing in embryogenesis—as fusion and/or differentiation defects. Grades of incomplete CLs were related to the severity of alveolar clefts (CAs) and hypoplasia, and permanent dentition was used to investigate which alveolar part is deficient in fusion/differentiation defects.

Results:

One hundred eight adult patients were included. All subphenotypes—96 unilateral and 12 bilateral clefts—could be classified into differentiation (79%), fusion (17%), fusion-differentiation (2%), or fusion and differentiation (2%) defects. The various grades of incomplete CLs were related to associated CAs and hypoplasia, and all alveolar deformities were located in the premaxillae.

Conclusions:

This study showed that all CL±A including the Simonart bands can be classified, that further morphological grading of incomplete CLs is clinically relevant, and that the premaxilla forms the deficient part in alveolar deformities.
Teachers’ Perspectives on the Impact of Cleft Lip and/or Palate During the School Years
Authors: Stock Nicola Marie , Ridley Matthew , Guest Ella
Published: April 2018

Background:

Cleft lip and/or palate (CL/P) poses many challenges for those affected throughout the school years, with recent studies pointing to a trend in poor educational outcomes. Previous research has highlighted the important role that teachers play in supporting young people with chronic health conditions yet studies in the field of CL/P suggest that teachers may lack knowledge of the condition, and underestimate pupils’ academic ability. Qualitative investigation of the impact of CL/P from the teacher’s perspective may provide additional insight as well as potential suggestions for improving the school experience for affected pupils.

Methods:

Twenty UK preschool, primary, and secondary school teachers with experience of teaching pupils with CL/P completed an open-ended survey, eliciting qualitative data.

Results:

Qualitative content analysis was performed. Data were presented under 5 key headings: Knowledge of CL/P and its effects, perceived impact of CL/P on education, teachers’ training needs, delivery of training, and impact of CL/P on teachers. Teachers were able to identify a number of potential social, emotional, and treatment-related challenges within the school setting, yet did not believe that CL/P would have a long-term impact on pupils’ educational achievement. Participating teachers reported that cleft-specific training and access to relevant resources would be highly beneficial.

Conclusions:

Acting as a platform for future research, this exploratory study provides insight into the challenges faced by teachers and offers suggestions for how to improve teachers’ understanding of CL/P, and their confidence in dealing with cleft-related issues.
Medication Use in Women and Men With Sudden Unexpected Death
Authors: Patel Sonalie , Conover Mitchell M. , Joodi Golsa , Chen Sarah , Simpson Ross J. , Deyo Zachariah M.
Published: April 2018

Background: In Wake County, NC, sudden unexpected death accounts for 10% to 15% of all natural deaths in individuals 18 to 64 years old. Medications such as aspirin, angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, statins, and β-blockers are recommended in guidelines to reduce cardiovascular events and even sudden death (β-blockers). However, guidelines are often underpracticed, even in high-risk patients, with noted disparities in women. Objective: We assessed the relation between prescription of evidence-based medications and sudden unexpected death in Wake County, NC. Methods: We analyzed 399 cases of sudden unexpected death for the time period March 1, 2013 to February 28, 2015 in Wake County, NC. Medications were assessed from available medical examiner reports and medical records and grouped using the third level of the Anatomical Therapeutic Chemical Classification System (ATC) codes. This study was reviewed and exempt by the University of North Carolina’s institutional review board. Results: Among 126 female and 273 male victims, women were prescribed more medications overall than men (6.5 vs 4.3, P = 0.001); however, the use of guideline-directed therapies was not different between genders in the chronic conditions associated with sudden death. Overall, there was remarkably low use of evidence-based medications. Conclusions: Our findings highlight the need to improve prescribing of evidence-based medications and to further explore the relationship between undertreatment and sudden unexpected death.
Rust and dust: Materiality and the feel of memory at Camp des Milles
Authors: Sumartojo Shanti , Graves Matthew
Published: April 2018

In this article, the authors explore the potential of state-sponsored memory sites to engender multi-chronological and sensorial accounts of the past, and create new meanings for visitors in doing so. They do this by recounting first-hand experiences of the Camp des Milles, a Second World War internment and deportation camp in the south of France, near Aix-en-Provence. Inaugurated in 2012, in addition to being an official lieu de mémoire, Camp des Milles also has an explicit pedagogical function in seeking to raise awareness of racism and anti-Semitism, and how to combat it. The article hinges on accounts of a visit to the site and accompanying photographs, which together provide an empirical starting point for a series of linked concepts that frame their arguments. Beginning with Manning’s notion of the ‘minor gesture’ ( The Minor Gesture, 2016), the authors build on recent work on more-than-representational approaches to memory and place, and draw in explorations of materiality and industrial ruins. Overall, they call for a more subtle and atmospheric understanding of state-sponsored memory sites, an understanding that attends to the emergent experiences people have in them, which allow us to understand their affective impact more clearly, and thus their potential to promulgate and intensify their messages.
On the concept of action in the study of interaction
Authors: Enfield NJ , Sidnell Jack
Published: April 2018

What is the relation between words and action? How does a person decide, based on what someone is saying, what would be an appropriate response? We argue that (1) every move combines independent semiotic features, to be interpreted under an assumption that social behavior is goal directed; (2) responding to actions is not equivalent to describing them; and (3) describing actions invokes rights and duties for which people are explicitly accountable. We conclude that interaction does not involve a ‘binning’ procedure in which the stream of conduct is sorted into discrete action types. Our argument is grounded in data from recordings of talk-in-interaction.
Comparative study of diesel engine cylinder deactivation transition strategies
Authors: Allen Cody M , Gosala Dheeraj B , Shaver Gregory M , McCarthy James
Published: April 2018

Cylinder deactivation is an effective strategy to improve diesel engine fuel efficiency and aftertreatment thermal management when implemented through deactivation of both fueling and valve motion for a set of cylinders. Brake power is maintained by injecting additional fuel into the remaining activated cylinders. The initial deactivation of cylinders can be accomplished in various ways, the two most common options being to trap freshly inducted charge in the deactivated cylinders or to trap combusted gases in the deactivated cylinders. The choice of trapping strategy dictates the in-cylinder pressure characteristics of the deactivated cylinders and has potential to affect torque, oil consumption, and emissions upon reactivation. The effort described here compares these trapping strategies through examination of in-cylinder pressures following deactivation. Proponents of each trapping strategy exist; however, the results discussed here suggest no significant performance differences. As an example, the in-cylinder pressures of both trapping strategies converge as quickly as seven cycles, less than 1 s, after deactivation at curb idle conditions.
Bursera copallifera Extracts Have Cytotoxic and Migration-Inhibitory Effects in Breast Cancer Cell Lines
Authors: Domínguez Fabiola , Maycotte Paola , Acosta-Casique Adilene , Rodríguez-Rodríguez Sofía , Moreno Diego A. , Ferreres Federico , Flores-Alonso Juan Carlos , Delgado-López María Guadalupe , Pérez-Santos Martín , Anaya-Ruiz Maricruz
Published: April 2018

Plants from the Bursera genus are widely distributed in the tropical dry forests of Mexico. In traditional medicine, extracts from different species of Bursera have been used for a wide range of biological activities, including the treatment of cancer-related symptoms. Compounds present in the Bursera genus include lignans, flavonoids, steroids, short-chain aliphatic alkanes, acetates, alcohols, ketones, and terpenoids. In some instances, secondary metabolites of these classes of compounds may induce cytotoxicity, and therefore we sought to investigate the effects of B. copallifera leaf extracts in breast cancer cell lines to evaluate their potential therapeutic value for the treatment of breast cancer, one of the most prevalent types of cancer in women worldwide. Two B. copallifera leaf extracts exerted cytotoxic effects on both the MCF7 and MDA-MB-231 breast cancer cell line models. The cytotoxic effect was more evident in the MDA-MB-231 triple negative cell line inhibiting also the migration of these cells. We identified hydroxycinnamic acid and flavonol derivatives as major phenolic components of the extracts. Our results strongly suggest a potential use of the Bursera leaf extracts rich in phenolic compounds, their individual phenolic compounds, or their combinations for the treatment of breast cancer.
Repair of TEVAR-Associated Type A Dissection in the Elderly Is Possible With Reasonable Morbidity and Mortality
Authors: Kornberger Angela , Petar Risteski , El Beyrouti Hazem , Khalil Mahmud , Burck Iris , Halloum Nancy , Beiras-Fernandez Andres , Vahl Christian-Friedrich
Published: April 2018

Background:

Type A aortic dissection (AAD) is a devastating complication of thoracic endovascular repair (TEVAR). In elderly patients, surgery for AAD carries considerable morbidity and mortality. Repair of AAD after previous TEVAR is an even greater challenge as it usually requires the arch to be addressed and a preexisting stent graft to be included into the aortic repair.

Methods:

A case series of 5 elderly patients who presented with acute AAD after previous TEVAR was reviewed. In 4 cases, there was retrograde AAD with involvement of the arch and stent graft. In 1 patient, intraoperative inspection showed no involvement of the arch. Three underwent ascending and subtotal arch replacement in moderate hypothermic circulatory arrest with selective cerebral perfusion. In 1 case, concomitant tricuspid valve repair was performed. The patient without involvement of the arch underwent emergent replacement of the ascending aorta in deep hypothermic circulatory arrest, and in the oldest, aged 88 years, surgery was limited to wrapping of the ascending aorta as an on-pump beating salvage procedure.

Results:

Four (80%) of 5 patients survived and were discharged after an intensive care unit stay of 17.45 ± 15.98 days and a hospital stay of 26.0 ± 10.98 days. Mortality was 20%. All survivors were discharged with appropriate rehabilitation potential and without lasting neurological disabilities.
Base of Aircraft Data–based operating cost prediction of arrival flight delay under short-term weather
Authors: Zhang Ming , Liu Kai , Kong Xianglu , Zhang Ming
Published: April 2018

In the pre-tactical phase of air traffic flow management, flights in terminal airspace generate plans, such as rerouting and holding, as influenced by the weather. Hence, the new flight rerouting and holding path should be confirmed by combining the original flight plan and the short-term weather radar map. Decision-making for rerouting and holding should consider not only flight safety but also the operating cost of flight delay acquired through accurate calculation. A specific fuel consumption model of leveling and descending phases of arrival aircraft in Base of Aircraft Data database was used in this article. Arrival route was divided into several leveling and descending legs, and the fuel consumption model of the arrival flight established. Delay time and fuel costs of the arrival flight attributed to the execution of a rerouting strategy and holding procedure were calculated, respectively. The operating cost prediction model of flight delay in the terminal area with consideration of the aircraft model and arrival route were established, and decision-making support was provided for diverted operation in the terminal in relation to flight delay cost. Finally, arrival routes in the terminal area in Shanghai were subdivided into different flight legs. The delay cost of the main aircraft model was calculated and a comparative analysis of arrival delay cost obtained through theoretical calculation and quick access recorder of the actual flight data was conducted. The results indicated that the proposed prediction model of flight delay cost could provide a relatively accurate basis for decision-making in aviation operation.
Blood Transfusion During Total Ankle Arthroplasty Is Associated With Increased In-Hospital Complications and Costs
Authors: Ewing Michael A. , Huntley Samuel R. , Baker Dustin K. , Smith Kenneth S. , Hudson Parke W. , McGwin Gerald , Ponce Brent A. , Johnson Michael D.
Published: April 2018

Introduction. Total ankle arthroplasty (TAA) is an increasingly used, effective treatment for end-stage ankle arthritis. Although numerous studies have associated blood transfusion with complications following hip and knee arthroplasty, its effects following TAA are largely unknown. This study uses data from a large, nationally representative database to estimate the association between blood transfusion and inpatient complications and hospital costs following TAA. Methods. Using the Nationwide Inpatient Sample (NIS) database from 2004 to 2014, 25 412 patients who underwent TAA were identified, with 286 (1.1%) receiving a blood transfusion. Univariate analysis assessed patient and hospital factors associated with blood transfusion following TAA. Results. Patients requiring blood transfusion were more likely to be female, African American, Medicare recipients, and treated in nonteaching hospitals. Average length of stay for patients following transfusion was 3.0 days longer, while average inpatient cost was increased by approximately 50%. Patients who received blood transfusion were significantly more likely to suffer from congestive heart failure, peripheral vascular disease, hypothyroidism, coagulation disorder, or anemia. Acute renal failure was significantly more common among patients receiving blood transfusion ( P < .001). Conclusion. Blood transfusions following TAA are infrequent and are associated with multiple medical comorbidities, increased complications, longer hospital stays, and increased overall cost.

Levels of Evidence: Level III: Retrospective, comparative study
The potential role of bioengineering and three-dimensional printing in curing global corneal blindness
Authors: Ludwig Parker E , Huff Trevor J , Zuniga Jorge M
Published: April 2018

An insufficiency of accessible allograft tissue for corneal transplantation leaves many impaired by untreated corneal disease. There is promise in the field of regenerative medicine for the development of autologous corneal tissue grafts or collagen-based scaffolds. Another approach is to create a suitable corneal implant that meets the refractive needs of the cornea and is integrated into the surrounding tissue but does not attempt to perfectly mimic the native cornea on a cellular level. Materials that have been investigated for use in the latter concept include natural polymers such as gelatin, semisynthetic polymers like gelatin methacrylate, and synthetic polymers. There are advantages and disadvantages inherent in natural and synthetic polymers: natural polymers are generally more biodegradable and biocompatible, while synthetic polymers typically provide greater control over the characteristics or property adjustment of the materials. Additive manufacturing could aid in the precision production of keratoprostheses and the personalization of implants.
Role of Frailty Scoring in the Assessment of Perioperative Mortality in Surgical Management of Tuberculous Spondylodiscitis in the Elderly
Authors: Shah Kunal , Kothari Manish , Nene Abhay
Published: April 2018

Study Design:

Retrospective study.

Objectives:

Treatment of spinal tuberculosis in the elderly involves consideration of compromised physiology, which often poses a clinical challenge to the surgeons to balance surgical safety versus deteriorating function. Frailty scoring has been reported as an effective tool to predict mortality and morbidity in cardiovascular surgery and recently in hip fractures. Its use in spinal surgery is scarcely reported.

Methods:

We included elderly patients operated for spinal tuberculosis. Demographic, clinical and radiological profile with operative details of instrumentation, blood loss, surgical duration and mortality were noted. Modified frailty score (MFS) was calculated for each patient. There were 26 patients (males 9, females 17) with a mean age of 73.2 years. The patients were divided into those with 30-day postoperative mortality (M) and those who survived (S). The null hypothesis was that the MFS was comparable in both the groups.

Results:

The M group had 5 patients (19.2%) and the S group consisted of 21 patients. There was no statistical difference between the groups with regard to mean age, sex, number of medical comorbidities, ASA (American Society of Anesthesiologists) grade, Frankel grade C or worse, blood loss, and operative time. The mean MFS in M group was 5 and in S group was 1.8, which was statistically significant ( P < .001).

Conclusions:

Higher MFS is associated with postoperative 30-day mortality in the elderly patients with spinal tuberculosis undergoing surgery. It can be used as a guide to predict 30-day postoperative mortality in these patients.
A Nuclear Complex? A Network Visualization of Japan’s Nuclear Industry and Regulatory Elite, 2006 to 2012
Authors: Dreiling Michael C. , Nakamura Tomoyasu
Published: April 2018

After the meltdown of the Fukushima Daiichi facility on March 11, 2011, in Japan, attempts by civil society actors to reroute the energy priorities of the country inevitably confronted obstacles in what scholars, activists, and journalists alike termed a nuclear complex. The authors’ original network data identify a dense field of overlapping executives and officials in Japan who forge long-term ties among the nuclear energy industry, the state, the leading business federation in Japan, nuclear scientists, and the national media. The authors use the Fruchterman-Reingold algorithm to present a large- n network visualization of these organizations and their ties in a manner that spatially distributes similar pairs of organizations proximate to one another.
A neuronal theory of sequential economic choice
Authors: Hayden Benjamin Y. , Moreno-Bote Rubén
Published: April 2018

Results of recent studies point towards a new framework for the neural bases of economic choice. The principles of this framework include the idea that evaluation is limited to a single option within the focus of attention and that we accept or reject that option relative to the entire set of alternatives. Rejection leads attention to a new option, although it can later switch back to a previously rejected one. The option to which a neuron’s firing rate refers is determined dynamically by attention and not stably by labelled lines. Value is always computed relative to the value of rejection. Comparison results not from explicit competition between discrete populations of neurons, but indirectly, as in a horse race, from the fact that the first option whose value crosses a threshold is selected. Consequently, comparison can occur within a single pool of neurons rather than by competition between two or more neuronal populations. The computations that constitute comparison thus occur at multiple levels, including premotor levels, simultaneously (i.e. the brain uses a distributed consensus), and not in discrete stages. This framework suggests a solution to a set of otherwise unresolved neuronal binding problems that result from the need to link options to values, comparisons to actions, and choices to outcomes.
How the Future of Sonography May Change the Outlook for Patients With Osteosarcoma
Authors: Hoya Stacey , Wogeman Linda , Allstadt Sara , King Glen
Published: April 2018

Sonography currently provides a variety of tools to support the diagnosis and treatment of osteosarcoma and, with the development of therapeutic ultrasound practices, could play an increasingly important role in the treatment of future patients with osteosarcoma. Currently, computed tomography, magnetic resonance imaging, and radiography are the preferred imaging modalities for bone lesions; treatment options for osteosarcoma primarily include highly toxic chemotherapies and surgeries that often result in limb loss. Unfortunately, osteosarcoma is rarely eliminated, and despite this, patients lose their lives after having a significant reduction in quality of life. Evolving therapies such as high-frequency focused ultrasound, ultrasound-enhanced delivery of photodynamic therapy, and low-intensity pulsed ultrasound may offer these patients an improved quality of life while also increasing efficacy of treatment. This canine case study illustrates the various ways in which sonography might contribute to the treatment plan for patients with osteosarcoma. It may provide a comparable model for the reimagining of treatment for future patients with osteosarcoma using a suite of therapeutic ultrasound applications.
Exposure to the gut microbiota drives distinct methylome and transcriptome changes in intestinal epithelial cells during postnatal development
Authors: Pan Wei-Hung , Sommer Felix , Falk-Paulsen Maren , Ulas Thomas , Best Lena , Fazio Antonella , Kachroo Priyadarshini , Luzius Anne , Jentzsch Marlene , Rehman Ateequr , Müller Fabian , Lengauer Thomas , Walter Jörn , Künzel Sven , Baines John F. , Schreiber Stefan , Franke Andre , Schultze Joachim L. , Bäckhed Fredrik , Rosenstiel Philip
Published: April 2018

Background

The interplay of epigenetic processes and the intestinal microbiota may play an important role in intestinal development and homeostasis. Previous studies have established that the microbiota regulates a large proportion of the intestinal epithelial transcriptome in the adult host, but microbial effects on DNA methylation and gene expression during early postnatal development are still poorly understood. Here, we sought to investigate the microbial effects on DNA methylation and the transcriptome of intestinal epithelial cells (IECs) during postnatal development.

Methods

We collected IECs from the small intestine of each of five 1-, 4- and 12 to 16-week-old mice representing the infant, juvenile, and adult states, raised either in the presence or absence of a microbiota. The DNA methylation profile was determined using reduced representation bisulfite sequencing (RRBS) and the epithelial transcriptome by RNA sequencing using paired samples from each individual mouse to analyze the link between microbiota, gene expression, and DNA methylation.

Results

We found that microbiota-dependent and -independent processes act together to shape the postnatal development of the transcriptome and DNA methylation signatures of IECs. The bacterial effect on the transcriptome increased over time, whereas most microbiota-dependent DNA methylation differences were detected already early after birth. Microbiota-responsive transcripts could be attributed to stage-specific cellular programs during postnatal development and regulated gene sets involved primarily immune pathways and metabolic processes. Integrated analysis of the methylome and transcriptome data identified 126 genomic loci at which coupled differential DNA methylation and RNA transcription were associated with the presence of intestinal microbiota. We validated a subset of differentially expressed and methylated genes in an independent mouse cohort, indicating the existence of microbiota-dependent “functional” methylation sites which may impact on long-term gene expression signatures in IECs.

Conclusions

Our study represents the first genome-wide analysis of microbiota-mediated effects on maturation of DNA methylation signatures and the transcriptional program of IECs after birth. It indicates that the gut microbiota dynamically modulates large portions of the epithelial transcriptome during postnatal development, but targets only a subset of microbially responsive genes through their DNA methylation status.
p53: emerging roles in stem cells, development and beyond
Authors: Jain Abhinav K. , Barton Michelle Craig
Published: April 2018

Most human cancers harbor mutations in the gene encoding p53. As a result, research on p53 in the past few decades has focused primarily on its role as a tumor suppressor. One consequence of this focus is that the functions of p53 in development have largely been ignored. However, recent advances, such as the genomic profiling of embryonic stem cells, have uncovered the significance and mechanisms of p53 functions in mammalian cell differentiation and development. As we review here, these recent findings reveal roles that complement the well-established roles for p53 in tumor suppression.
Axonal mRNA transport and translation at a glance
Authors: Sahoo Pabitra K. , Smith Deanna S. , Perrone-Bizzozero Nora , Twiss Jeffery L.
Published: April 2018

Localization and translation of mRNAs within different subcellular domains provides an important mechanism to spatially and temporally introduce new proteins in polarized cells. Neurons make use of this localized protein synthesis during initial growth, regeneration and functional maintenance of their axons. Although the first evidence for protein synthesis in axons dates back to 1960s, improved methodologies, including the ability to isolate axons to purity, highly sensitive RNA detection methods and imaging approaches, have shed new light on the complexity of the transcriptome of the axon and how it is regulated. Moreover, these efforts are now uncovering new roles for locally synthesized proteins in neurological diseases and injury responses. In this Cell Science at a Glance article and the accompanying poster, we provide an overview of how axonal mRNA transport and translation are regulated, and discuss their emerging links to neurological disorders and neural repair.