bluuebunny/crossref_metadata_2025 huggingface dataset:
Testosterone Levels Correlate With Grade Group 5 Prostate Cancer: Another Step Toward Personalized Medicine
Authors: Capogrosso Paolo , Ventimiglia Eugenio , Moschini Marco , Boeri Luca , Farina Elena , Finocchio Nadia , Gandaglia Giorgio , Fossati Nicola , Briganti Alberto , Montorsi Franscesco , Salonia Andrea
Published: October 2016

BACKGROUND

Controversial results have shown a significant association with either low or high total testosterone (tT) levels and high risk prostate cancer (PCa). We tested the relationship between circulating tT and grade group 5 (G5) PCa at radical prostatectomy (RP) in patients with preoperative low‐ to intermediate‐risk disease.

METHODS

Serum sex hormones were assessed the day before RP in a cohort of 846 patients with low‐ to intermediate‐risk PCa. Patients were segregated using the new 5‐tiered Gleason grade groups. Restricted cubic spline functions and logistic regression analyses tested the association between sex hormones and G5 PCa. Differences in potential predictive accuracy (PA) were assessed for tT and prostate‐specific antigen (PSA) levels.

RESULTS

Overall, 27 men (3.2%) had G5 PCa at RP, and this group had higher PSA values than patients with G1–G4 PCa (P = 0.02). The groups did not differ in terms of preoperative mean hormonal values. Both low and high circulating tT values depicted a nonlinear U‐shaped correlation with G5 PCa at RP. The lowest and highest (10th and 90th percentiles) tT values and biopsy PCa grade emerged as multivariable independent predictors of G5 PCa at RP (all P < 0.05). PA for G5 PCa did not differ between tT (area under the curve [AUC] 0.631) and PSA (AUC 0.636).

CONCLUSIONS

Circulating tT was a significant predictor of G5 PCa at RP in patients with preoperative low‐ to intermediate‐risk disease. Preoperative tT and PSA values showed similar PA for the most aggressive disease, confirming a potential role for circulating androgens in preoperative risk assessment of PCa patients. Prostate 77:234–241, 2017. © 2016 Wiley Periodicals, Inc.
Predicting Prostate Cancer Recurrence After Radical Prostatectomy
Authors: Jeffers Abra , Sochat Vanessa , Kattan Michael W. , Yu Changhong , Melcon Erin , Yamoah Kosi , Rebbeck Timothy R. , Whittemore Alice S.
Published: October 2016

BACKGROUND

Prostate cancer prognosis is variable, and management decisions involve balancing patients’ risks of recurrence and recurrence‐free death. Moreover, the roles of body mass index (BMI) and race in risk of recurrence are controversial [1,2]. To address these issues, we developed and cross‐validated RAPS (Risks After Prostate Surgery), a personal prediction model for biochemical recurrence (BCR) within 10 years of radical prostatectomy (RP) that includes BMI and race as possible predictors, and recurrence‐free death as a competing risk.

METHODS

RAPS uses a patient's risk factors at surgery to assign him a recurrence probability based on statistical learning methods applied to a cohort of 1,276 patients undergoing RP at the University of Pennsylvania. We compared the performance of RAPS to that of an existing model with respect to calibration (by comparing observed and predicted outcomes), and discrimination (using the area under the receiver operating characteristic curve (AUC)).

RESULTS

RAPS’ cross‐validated BCR predictions provided better calibration than those of an existing model that underestimated patients’ risks. Discrimination was similar for the two models, with BCR AUCs of 0.793, 95% confidence interval (0.766–0.820) for RAPS, and 0.780 (0.745–0.815) for the existing model. RAPS’ most important BCR predictors were tumor grade, preoperative prostate‐specific antigen (PSA) level and BMI; race was less important [3]. RAPS’ predictions can be obtained online at https://predict.shinyapps.io/raps.

CONCLUSION

RAPS’ cross‐validated BCR predictions were better calibrated than those of an existing model, and BMI information contributed substantially to these predictions. RAPS predictions for recurrence‐free death were limited by lack of co‐morbidity data; however the model provides a simple framework for extension to include such data. Its use and extension should facilitate decision strategies for post‐RP prostate cancer management. Prostate 77:291–298, 2017. © 2016 Wiley Periodicals, Inc.
The np Chart with Guaranteed In‐control Average Run Lengths
Authors: Faraz Alireza , Heuchenne Cédric , Saniga Erwin
Published: October 2016

We evaluate the in‐control performance of the np‐control chart with estimated parameter conditional on the Phase I sample. We then apply the bootstrap method to adjust the control chart limits to guarantee the desired in‐control average run length (ARL0) value in the monitoring stage. The adjusted limits ensure that the ARL0 would take a value greater than the desired value (say, B) with a certain specified probability, that is, Pr(ARL0 > B) = 1 − ρ. The results indicate that adjusting control limits is not always necessary. We present a method to design control charts such that in control and out of control run lengths are guaranteed with pre specified probabilities. This method is an improvement of the classical statistical design approach employing constraints on in control and out of control ARL because, with this approach, there is a substantial probability that the actual run length in control may be too small. In addition, using the ARL approach may result in an actual out of control run length that is too large. Some numerical examples illustrate the efficacy of this design method. Copyright © 2016 John Wiley & Sons, Ltd.
Methanol adducts leading to the identification of a reactive aldehyde metabolite of CPAQOP in human liver microsomes by ultra‐high‐performance liquid chromatography/mass spectrometry
Authors: Martin Scott , Lenz Eva M. , Smith Robin , Temesi David G. , Orton Alexandra L. , Clench Malcolm R.
Published: October 2016

Rationale

The incubation of CPAQOP (1‐[(2R)‐2‐[[4‐[3‐chloro‐4‐(2‐pyridyloxy)anilino]quinazolin‐5‐yl]oxymethyl]‐1‐piperidyl]‐2‐hydroxy) with human liver microsomes generated several metabolites that highlighted the hydroxyacetamide side chain was a major site of metabolism for the molecule. The metabolites were derived predominantly from oxidative biotransformations; however, two unexpected products were detected by liquid chromatography/ultraviolet/mass spectrometry (LC/UV/MS) and identified as methanol adducts. This observation prompted further LC/MS investigations into their formation.

Methods

Three separate incubations of CPAQOP were conducted in human liver microsomes; Naïve, fortified with methoxyamine and fortified with glutathione. Separation was achieved via ultra‐high‐performance liquid chromatography with either methanol or acetonitrile gradients containing formic acid. MS analysis was conducted by electrospray ionisation LTQ Orbitrap mass spectrometry acquiring accurate mass full scan, data‐dependent MS2 and all ion fragmentation.

Results

No methanol adducts were detected by MS when acetonitrile was used in the mobile phase instead of methanol, verifying that a metabolite was reacting with methanol on column. Although this reactive metabolite could not be isolated or structurally characterised by LC/MS directly, product ion spectra of the methanol adducts confirmed addition of methanol on the hydroxyacetamide side chain. Additional experiments using methoxyamine showed the disappearance of the two methanol adducts and appearance of a methoxyamine adduct, confirming the presence of an aldhyde. Product ion spectra of the methoxyamine adduct confirmed addition of methoxyamine to the hydroxyacetamide side chain.

Conclusions

The proposed bioactivation of CPAQOP occurred via the reactive aldehyde intermediate, which readily reacted with methanol in the mobile phase to form a pair of isomeric hemiacetal methanol adducts. In acidified methanol the equilibrium favoured the methanol adduct and in acidified acetonitrile it favoured the hydrate; therefore, the reactive aldehyde metabolite was not detected and could not be structurally characterised directly. Copyright © 2016 John Wiley & Sons, Ltd.
An Interactive System for Fine Motor Rehabilitation
Authors: Posada-Gómez Ruben , Montaño-Murillo Roberto A. , Martínez-Sibaja Albino , Alor-Hernández Giner , Aguilar-Lasserre Alberto A. , Reyes-Fernández Miriam C.
Published: October 2016

Purpose:

One of the most important aspects in neuromotor rehabilitation is the need of feedback for patients. The rehabilitation system’s efficiency relies on the therapist’s judgment; the therapist tells the patient whether he/she is performing the exercises correctly. This process may be quite subjective, because it depends on the therapist’s personal opinion. On the other hand, recent studies have shown that vibrotactile biofeedback can improve the effectiveness of interaction as it is a very helpful tool in the physiological process of neuromotor rehabilitation.

Design:

We designed an interactive system focused on rehabilitation of the upper limbs using active markers and image processing, which consists of drawing activities in both augment and virtual reality.

Methods:

The system gives the user a correction through multimodal stimuli feedback (vibrotactile, visual, and sound stimulus) and force measurement to let the patients know if they are not achieving the tasks’ goals.

Findings:

The developed system could be used by nursing assistants to better help patients. The purpose of this system was assisting patients with injuries in shoulders, elbows, or wrists, providing an audio-vibrotactile feedback as a factor of correction in the movements of the patient. To examine our system, 11 participants were asked to participate in an experiment where they performed activities focused to strengthen their fine motor movements.

Conclusions and Clinical Relevance:

Results showed show that patients’ fine motor skills improved 10% on average by comparing their error rates throughout the sessions.
Dynamic reconfiguration of cloud application architectures
Authors: Zúñiga‐Prieto Miguel , González‐Huerta Javier , Insfran Emilio , Abrahão Silvia
Published: October 2016

Service‐based cloud applications are software systems that continuously evolve to satisfy new user requirements and technological changes. This kind of applications also require elasticity, scalability, and high availability, which means that deployment of new functionalities or architectural adaptations to fulfill service level agreements (SLAs) should be performed while the application is in execution. Dynamic architectural reconfiguration is essential to minimize system disruptions while new or modified services are being integrated into existing cloud applications. Thus, cloud applications should be developed following principles that support dynamic reconfiguration of services, and also tools to automate these reconfigurations at runtime are needed. This paper presents an extension of a model‐driven method for dynamic and incremental architecture reconfiguration of cloud services that allows developers to specify new services as software increments, and the tool to generate the implementation code for the services integration logic and the deployment and architectural reconfiguration scripts specific to the cloud environment in which the service will be deployed (e.g., Microsoft Azure). We also report the results of a quasi‐experiment that empirically validate our method. It was conducted to evaluate their perceived ease of use, perceived usefulness, and perceived intention to use. The results show that the participants perceive the method to be useful, and they also expressed their intention to use the method in the future. Although further experiments must be carried out to corroborate these results, the method has proven to be a promising architectural reconfiguration process for cloud applications in the context of agile and incremental development processes. Copyright © 2016 John Wiley & Sons, Ltd.
A Network‐Based Analysis of Team Coordination and Shared Cognition in Systems Engineering
Authors: Avnet Mark S.
Published: October 2016

This paper presents a network‐based approach for analyzing team coordination and shared cognition in engineering design teams. The research setting is an Integrated Concurrent Engineering (ICE) laboratory in which teams of approximately 20 engineers are collocated to conduct rapid conceptual design of scientific spacecraft. A design structure matrix (DSM) of expected interactions is constructed from technical information flow data, and DSM representations of reported interactions are created using survey data from 10 ICE design teams. A comparative analysis of expected and reported interactions is used to calculate a metric of team coordination called socio‐technical congruence (STC). To examine shared cognition, pairwise shared mental models (SMMs) are measured using pre‐ and post‐session surveys on system design drivers. Shared knowledge networks (SMMs as edges) are constructed, and team learning is measured as the change in network structure over time. Analysis reveals statistically significant correlations between team learning and each of three technical attributes (system development time, launch mass, and mission concept maturity) and between team learning and team coordination. These results indicate that team members learn most from each other when working on difficult or unfamiliar problems and when expected and reported interactions are aligned. The paper concludes that team coordination and the design product in ICE are not necessarily directly related to each other but that both are related to shared cognition. Although this study focuses on conceptual design, it lays the foundation for future work examining the role of team coordination and shared cognition in full‐scale system development programs.
Evaluation of the Antioxidant Activity of Copper(II) Complexes containing Tris‐(hydroxymethyl)aminomethane (TRIS) Units
Authors: Canabarro Cibele M. , Ceolin Joice , Siqueira Josiéli D. , Iglesias Bernardo A. , Manzoni de Oliveira Gelson , Back Davi F. , Campos Patrick T.
Published: October 2016

The structural analysis and the SOD‐like activity of CuII complexes [(Cu)(C16H18N3O5)]ClO4 (1) and [(Cu)4(C36H52N8O12)] (2) are described with ligands obtained from the condensation of picolinaldehyde and 2‐formylpyrrole with tris(hydroxymethyl)aminomethane (TRIS). Finally, complex 1 catalyzes the dismutation of superoxide efficiently with IC50 values in the range of 0.43 micromolar solution, evaluated through the inhibition of the photoreduction of nitro blue tetrazolium (NBT) (superoxide dismutase assay).
1,2,4‐Triazol‐5‐ylidenes versus Imidazol‐2‐ylidenes for the Stabilization of Phosphorus(I) Cations
Authors: Elnajjar Fawzia O. , Binder Justin F. , Kosnik Stephanie C. , Macdonald Charles L. B.
Published: October 2016

The synthesis and characterization of a series of 1,4‐dialkyl‐1,2,4‐triazolium iodide and tetraphenylborate salts featuring methyl, ethyl, and isopropyl substituents and their use as precursors, in conjunction with triphosphenium reagents, to generate 1,4‐dialkyl‐1,2,4‐triazol‐5‐ylidene‐stabilized phosphorus(I) ions is described. The use of tetraphenyl borate salts of both reagents produces the most pure products. The structural and spectroscopic features of the products are compared to those of analogous ions featuring 1,3‐imidazol‐2‐ylidene ligands.
Isolation and Reactivity of a Frustrated N‐Heterocyclic Carbene‐Borane
Authors: Winkler Andrea , Freytag Matthias , Jones Peter G. , Tamm Matthias
Published: October 2016

The synthesis of the frustrated carbene‐borane 4‐(9‐borabicyclo[3.3.1]nona‐9‐yl)‐1,3‐di‐tert‐butylimidazolin‐2‐ylidene (6) was accomplished by deprotonation of the N‐heterocyclic carbene (NHC) 1,3‐di‐tert‐butylimidazolin‐2‐ylidene (1) at the 4‐position with n‐butyllithium, followed by addition of 9‐chloro‐9‐borabicyclo[3.3.1]nonane (BBN‐Cl). The abnormal carbene‐borane adduct 5, with the BBN‐Cl moiety at the 4‐position, was obtained from the reaction of 1 with BBN‐Cl; however, its conversion into 6 by treatment with K[N(SiMe3)2] (potassium hexamethyldisilazide, KHMDS) was not achieved. The reactions of 6 with the rhodium(I) complexes [Rh(COD)Cl]2 (COD = 1,4‐cyclooctadiene) and [Rh(CO)2Cl]2 afforded the complexes cis‐[(6)Rh(COD)Cl] (7) and cis‐[(6)Rh(CO)2Cl] (8), with the latter allowing assessment of the σ‐donor/π‐acceptor properties of 6 by IR spectroscopy. The reactivity of 6 towards carbon dioxide, phenylacetylene and acetonitrile was studied, affording the labile adduct 6·CO2 (9), whereas irreversible deprotonation and formation of the imidazolium phenylalkynylborate 10 and the imidazolium cyanomethylborate 11 was observed for PhCCH and CH3CN. The molecular structures of 5, 7, 8, 10, and 11 were established by X‐ray diffraction analyses.
Transforming Boolean equalities into constraints
Authors: Antoy Sergio , Hanus Michael
Published: October 2016

Although functional as well as logic languages use equality to discriminate between logically different cases, the operational meaning of equality is different in such languages. Functional languages reduce equational expressions to their Boolean
values, True or False, logic languages use unification to check the validity only and fail otherwise. Consequently, the language Curry, which amalgamates functional and logic programming features, offers two kinds of equational expressions so that the programmer has to distinguish between these uses. We show that this distinction can be avoided by providing an analysis and transformation method that automatically selects the appropriate operation. Without this distinction in source programs, the language design can be simplified and the execution of programs can be optimized. As a consequence, we show that one kind of equational expressions is sufficient and unification is nothing else than an optimization of Boolean equality.
Robotic Site Adjusted Levator Transection for Carcinoma of the Rectum: A Modification of the Existing Cylindrical Abdominoperineal Resection for Eccentrically Located Tumors
Authors: Pai Ajit , Eftaiha Saleh Mohamed , Melich George , Park John J. , Lin Pey‐yi Kevin , Prasad Leela M. , Marecik Slawomir J.
Published: October 2016

Background

Today, extralevator abdominoperineal resection is the standard of care for low rectal cancers with sphincter involvement or location precluding anastomosis. This procedure, while effective from an oncologic point of view, is morbid, with a high incidence of wound complications and genitourinary, and sexual dysfunction. We present a modification of this procedure via a robotic approach, which maintains the radicality while reducing the soft tissue loss and potentially the morbidity.

Methods

Over a 2‐year period, five patients (four men and one woman) with eccentric low rectal cancers following neoadjuvant chemoradiation underwent a robot‐assisted modified abdominoperineal resection with wide levator transection on the tumor side and conservative levator division on the opposite side. These patients were prospectively followed. Perioperative outcomes, pathologic specimen measures, wound‐related problems, and local and systemic recurrences were documented and analyzed.

Results

All procedures were successfully completed without conversion. Average body mass index was 32 kg/m2. The mean operative time and blood loss were 370 min and 130 ml, respectively. All specimens had an intact mesorectal envelope with no tumor perforations, and the mean lymph node yield was 16. There were no urinary complications or perineal wound infections. At a median follow‐up of 14 months, all patients remain disease‐free.

Conclusions

Modified robotic cylindrical abdominoperineal resection with site adjusted levator transection for rectal cancer is an oncologically sound operation in eccentrically located tumors. It maintains the radicality of conventional extralevator abdominoperineal resection, while also reducing the soft tissue loss and thereby potentially the morbidity.
Chylous Ascites Management After Pancreatic Surgery
Authors: Tabchouri Nicolas , Frampas Eric , Marques Frederic , Blanchard Claire , Jirka Adam , Regenet Nicolas
Published: October 2016

Background

Postoperative chylous ascites (CA) following pancreatic surgery is uncommon. If left untreated, it leads to malnutrition, immunodeficiency and increased postoperative morbidity and mortality. The aim of this study was to seek out risk factors associated with CA onset and conservative treatment (CT) failure in order to determine better management of CA following pancreatic resection.

Materials and methods

All consecutive patients who underwent pancreatic surgery between 2004 and 2014 were reviewed retrospectively. Main demographic, clinical and pathological data were searched for CA risk factors. Patients with CA successfully treated with CT alone were compared to those requiring additional bipedal lymphangiography (BPLAG) in order to seek out risk factors associated with CT failure.

Results

Fifteen patients (2.4 %) developed CA after pancreatic surgery. Para‐aortic lymph node sampling and early enteral feeding were found to be independent risk factors for postoperative CA (OR 6.36, p = 0.024 and OR 12.18, p = 0.02, respectively). CT was successful in ten patients, and five patients required additional BPLAG to achieve CA resolution. Statistical analysis revealed no significant risk factors for CT failure, including total lymph node count (p = 0.196), para‐aortic lymph node sampling (p = 0.661) or maximum chyle loss per day (p = 0.758).

Conclusions

Owing to postoperative CA rarity, there is no consensus in treatment. Early on, CT should be attempted in all patients with CA. BPLAG is a safe and efficient procedure that should be discussed earlier in the step‐up therapeutic management.
A Retrospective One‐Year Estimation of the Volume and Nature of Surgical and Anaesthetic Services Delivered to the Populations of the Fako Division of the South‐West Region of Cameroon: An Urgent Call for Action
Authors: Chichom‐Mefire Alain , Mbome Njie Victor , Verla Vincent , Atashili Julius
Published: October 2016

Background

Surgery‐related conditions account for the majority of admissions in primary referral hospitals in Sub‐Saharan Africa. The role of surgery in the reduction of global disease burden is well recognized, but there is a great qualitative and quantitative disparity in the delivery of surgical and anaesthetic services between countries. This study aims at estimating the nature and volume of surgery delivered in an entire administrative division of Cameroon.

Methods

In this retrospective survey conducted during the year 2013, we used a standard tool to analyse the infrastructure and human resources involved in the delivery of surgical and anaesthetic services in the Fako division in the south‐west region of Cameroon. We also estimated the nature and volume of surgical services as a rate per catchment population.

Results

Public, private and mission hospital contributed equally to the delivery of surgical services in the Fako. For every 100,000 people, there were <5 operative rooms. A total of 2460 surgical interventions were performed by 2.2 surgeons, 1.1 gynaecologists and 0.3 anaesthetists. These surgical interventions consisted mostly of minor and emergency procedures. Neurosurgery, paediatric, thoracic and endocrine surgery were almost non‐existent.

Conclusions

The volume of surgery delivered in the Fako is far below the minimum rates required to meet up with the most basic requirements of the populations. It is likely that most of these surgical needs are left unattended. A community‐based assessment of unmet surgical needs is necessary to accurately estimate the magnitude of the problem and guide surgical capacity improvements.
Global Neighborhoods: Beyond the Multiethnic Metropolis
Authors: Zhang Wenquan , Logan John R.
Published: October 2016

Neighborhoods where blacks and whites live in integrated settings alongside Hispanics and Asians represent a new phenomenon in the United States. These “global neighborhoods” have previously been identified in the nation’s most diverse metropolitan centers. This study examines the full range of metropolitan areas to ask whether similar processes are occurring in other parts of the country. Is there evidence of stable racial integration in places that lack such diversity? What are the paths of neighborhood change in areas with few Hispanic or Asian residents, or areas where Hispanics are the principal minority group, or where there is no large minority presence at all? We distinguish four types of metropolitan regions: white, white/black, white/Hispanic/Asian, and multiethnic. These regions necessarily differ greatly in neighborhood composition, but some similar trajectories of neighborhood change are found in all of them. The results provide new evidence of the effect of Hispanic and Asian presence on black-white segregation in all parts of the country.
Medical Pathologies and Hut Guardians’ Ability to Provide First Aid in Mountain Huts: A Prospective Observational Study
Authors: Blancher Marc , Colonna d’Istria Jérôme , Coste Amandine , Saint Guilhem Philippine , Pierre Antoine , Clausier Flora , Debaty Guillaume , Bosson Jean Luc , Briot Raphaël , Bouzat Pierre
Published: October 2016

Objective

To describe the resources for medical condition management in mountain huts and the epidemiology of such events.

Methods

We conducted a 3-step study from April 2013 to August 2014 in French mountain huts. The first step consisted of collecting data regarding the first aid equipment available in mountain huts. The second step consisted of a qualitative evaluation of the mountain hut guardian’s role in medical situations through semistructured interviews. Finally, a prospective observational study was conducted in the summer season to collect all medical events (MEs) that occurred during that period.

Results

Out of 164 hut guardians, 141 (86%) had a basic life support diploma. An automatic external defibrillator was available in 41 (26%) huts, and 148 huts (98%) were equipped with a first aid kit. According to semistructured interviews, hut guardians played a valuable role in first aid assistance. Regarding the observational study, 306 people requested the hut guardian’s help for medical reasons in 87 of the 126 huts included. A total of 501 MEs for approximately 56,000 hikers (0.85%) were reported, with 280 MEs (56%) involving medical pathologies and 221 (44%) MEs involving trauma-related injuries.

Conclusions

MEs had low prevalence, but the hut guardian played a valuable role as a first aid responder.
Semiparametric cross entropy for rare-event simulation
Authors: Botev Z. I. , Ridder A. , Rojas-Nandayapa L.
Published: October 2016

The cross entropy is a well-known adaptive importance sampling method which requires estimating an optimal importance sampling distribution within a parametric class. In this paper we analyze an alternative version of the cross entropy, where the importance sampling distribution is selected instead within a general semiparametric class of distributions. We show that the semiparametric cross entropy method delivers efficient estimators in a wide variety of rare-event problems. We illustrate the favourable performance of the method with numerical experiments.
Bit flipping and time to recover
Authors: Muratov Anton , Zuyev Sergei
Published: October 2016

We call `bits' a sequence of devices indexed by positive integers, where every device can be in two states: 0 (idle) and 1 (active). Start from the `ground state' of the system when all bits are in 0-state. In our first binary flipping (BF) model the evolution of the system behaves as follows. At each time step choose one bit from a given distribution P on the positive integers independently of anything else, then flip the state of this bit to the opposite state. In our second damaged bits (DB) model a `damaged' state is added: each selected idling bit changes to active, but selecting an active bit changes its state to damaged in which it then stays forever. In both models we analyse the recurrence of the system's ground state when no bits are active. We present sufficient conditions for both the BF and DB models to show recurrent or transient behaviour, depending on the properties of the distribution P. We provide a bound for fractional moments of the return time to the ground state for the BF model, and prove a central limit theorem for the number of active bits for both models.
Ergodicity of age-dependent inventory control systems
Authors: Olsson Fredrik , Turova Tatyana S.
Published: October 2016

We consider continuous review inventory systems with general doubly stochastic Poisson demand. In this specific case the demand rate, experienced by the system, varies as a function of the age of the oldest unit in the system. It is known that the stationary distributions of the ages in such models often have a strikingly simple form. In particular, they exhibit a typical feature of a Poisson process: given the age of the oldest unit the remaining ages are uniform. The model we treat here generalizes some known inventory models dealing with partial backorders, perishable items, and emergency replenishment. We derive the limiting joint density of the ages of the units in the system by solving partial differential equations. We also answer the question of the uniqueness of the stationary distributions which was not addressed in the related literature.
Quantile sensitivity estimation for dependent sequences
Authors: Jiang Guangxin , Fu Michael C.
Published: October 2016

In this paper we estimate quantile sensitivities for dependent sequences via infinitesimal perturbation analysis, and prove asymptotic unbiasedness, weak consistency, and a central limit theorem for the estimators under some mild conditions. Two common cases, the regenerative setting and ϕ-mixing, are analyzed further, and a new batched estimator is constructed based on regenerative cycles for regenerative processes. Two numerical examples, the G/G/1 queue and the Ornstein–Uhlenbeck process, are given to show the effectiveness of the estimator.
One-component regular variation and graphical modeling of extremes
Authors: Hitz Adrien , Evans Robin
Published: October 2016

The problem of inferring the distribution of a random vector given that its norm is large requires modeling a homogeneous limiting density. We suggest an approach based on graphical models which is suitable for high-dimensional vectors. We introduce the notion of one-component regular variation to describe a function that is regularly varying in its first component. We extend the representation and Karamata's theorem to one-component regularly varying functions, probability distributions and densities, and explain why these results are fundamental in multivariate extreme-value theory. We then generalize the Hammersley–Clifford theorem to relate asymptotic conditional independence to a factorization of the limiting density, and use it to model multivariate tails.
Renewal approximation for the absorption time of a decreasing Markov chain
Authors: Alsmeyer Gerold , Marynych Alexander
Published: October 2016

We consider a Markov chain (Mn)n≥0 on the set ℕ0 of nonnegative integers which is eventually decreasing, i.e. ℙ{Mn+1<Mn  |  Mn≥a}=1 for some a∈ℕ and all n≥0. We are interested in the asymptotic behavior of the law of the stopping time T=T(a)≔inf{k∈ℕ0:  Mk<a} under ℙn≔ℙ (·  |  M0=n) as n→∞. Assuming that the decrements of (Mn)n≥0 given M0=n possess a kind of stationarity for large n, we derive sufficient conditions for the convergence in the minimal Lp-distance of ℙn(T−an)∕bn∈·) to some nondegenerate, proper law and give an explicit form of the constants an and bn.
The SEIS model, or, the contact process with a latent stage
Authors: Foxall Eric
Published: October 2016

The susceptible→exposed→infectious→susceptible (SEIS) model is well known in mathematical epidemiology as a model of infection in which there is a latent period between the moment of infection and the onset of infectiousness. The compartment model is well studied, but the corresponding particle system has so far received no attention. For the particle system model in one spatial dimension, we give upper and lower bounds on the critical values, prove convergence of critical values in the limit of small and large latent time, and identify a limiting process to which the SEIS model converges in the limit of large latent time.
Longest paths in random Apollonian networks and largest r-ary subtrees of random d-ary recursive trees
Authors: Collevecchio Andrea , Mehrabian Abbas , Wormald Nick
Published: October 2016

Let r and d be positive integers with r<d. Consider a random d-ary tree constructed as follows. Start with a single vertex, and in each time-step choose a uniformly random leaf and give it d newly created offspring. Let 𝒯d,t be the tree produced after t steps. We show that there exists a fixed δ<1 depending on d and r such that almost surely for all large t, every r-ary subtree of 𝒯d,t has less than tδ vertices. The proof involves analysis that also yields a related result. Consider the following iterative construction of a random planar triangulation. Start with a triangle embedded in the plane. In each step, choose a bounded face uniformly at random, add a vertex inside that face and join it to the vertices of the face. In this way, one face is destroyed and three new faces are created. After t steps, we obtain a random triangulated plane graph with t+3 vertices, which is called a random Apollonian network. We prove that there exists a fixed δ<1, such that eventually every path in this graph has length less than t𝛿, which verifies a conjecture of Cooper and Frieze (2015).
1H magnetic resonance spectroscopy evidence for occipital involvement in treatment-naive paediatric obsessive–compulsive disorder
Authors: Ljungberg Maria , Nilsson Marie K. L. , Melin Karin , Jönsson Lars , Carlsson Arvid , Carlsson Åsa , Forssell-Aronsson Eva , Ivarsson Tord , Carlsson Maria , Starck Göran
Published: October 2016

Objective

Obsessive–compulsive disorder (OCD) is a chronic psychiatric disorder leading to considerable distress and disability. Therapies are effective in a majority of paediatric patients, however, many only get partial response. It is therefore important to study the underlying pathophysiology of the disorder.

Methods

1H magnetic resonance spectroscopy (MRS) was used to study the concentration of brain metabolites in four different locations (cingulate gyrus and sulcus, occipital cortex, thalamus and right caudate nucleus). Treatment-naive children and adolescents with OCD (13 subjects) were compared with a group of healthy age- and gender-matched subjects (11 subjects). Multivariate analyses were performed on the concentration values.

Results

No separation between controls and patients was found. However, a correlation between metabolite concentrations and symptom severity as measured with the Children’s Yale-Brown Obsessive–Compulsive Scale (CY-BOCS) was found. Strongest was the correlation with the CY-BOCS obsession subscore and aspartate and choline in the caudate nucleus (positively correlated with obsessions), lipids at 2 and 0.9 ppm in thalamus, and occipital glutamate+glutamine, N-acetylaspartate and myo-inosytol (negatively correlated with obsessions).

Conclusions

The observed correlations between 1H MRS and CY-BOCS in treatment-naive patients further supports an occipital involvement in OCD. The results are consistent with our previous study on adult OCD patients. The 1H MRS data were not supportive of a separation between the patient and control groups.
Glial cells as key elements in the pathophysiology and treatment of bipolar disorder
Authors: Keshavarz Mojtaba
Published: October 2016

Objective

The exact pathophysiology of bipolar disorder (BD) is not yet fully understood, and there are many questions in this area which should be answered. This review aims to discuss the roles of glial cells in the pathophysiology of BD and their contribution to the mechanism of action of mood-stabilising drugs.

Methods

We critically reviewed the most recent advances regarding glial cell roles in the pathophysiology and treatment of BD and the neuroprotective and neurotrophic effects of these cells.

Results

Postmortem studies revealed a decrease in the glial cell number or density in the specific layers of prefrontal and anterior cingulate cortex in the patients with BD, whereas there was no difference in other brain regions, such as entorhinal cortex, amygdala and hippocampus. Astrocytes and oligodendrocytes were the most important glial types that were responsible for the glial reduction, but microglia activation rather than loss may be implicated in BD. The decreased number or density of glial cells may contribute to the pathological changes observed in neurons in the patients with BD. Alteration of specific neurotrophic factors such as glial cell line-derived neurotrophic factor and S100B may be an important feature of BD. Glial cells mediate the therapeutic effects of mood-stabilising agents in the treatment of BD.

Conclusion

Recent studies provide important evidence on the impairment of glial cells in the pathophysiology and treatment of BD. However, future controlled studies are necessary to elucidate different aspects of glial cells contribution to BD, and the mechanism of action of mood-stabilising drugs.
Political Corruption Traps
Authors: Klašnja Marko , Little Andrew T. , Tucker Joshua A.
Published: October 2016

Academics and policymakers recognize that there are serious costs associated with systemic corruption. Stubbornly, many countries or regions remain stuck in a high-corruption equilibrium—a “corruption trap.” Most existing theories concentrate on mutually reinforcing expectations of corrupt behavior among a fixed set of bureaucrats or politicians, implying that changing such expectations can lead to lower corruption. We develop models that more fully characterize thepoliticalnature of corruption traps by also analyzing the behavior of voters and entrants to politics, as well their interaction with incumbent politicians. We show that corruption traps can arise through strategic behavior of each set of actors, as well as through their interrelations. By linking politician, voter, and entrant behavior, we provide an explanation for why simply trying to change expectations among one set of actors is likely insufficient for eliminating corruption traps.
RESPONSE TO ‘SIMILARITY AND DIFFERENCE, CONTEXT AND TRADITION, IN CONTEMPORARY RELIGIOUS MOVEMENTS IN WEST AFRICA’ BY J. D. Y. PEEL
Authors: Obadare Ebenezer
Published: October 2016

In the immediate aftermath of ‘9/11’, it took very little for the axiom that adherents of evangelical Christianity and reformist Islam inhabit discrepant, permanently warring publics to solidify. With the very air laden with ‘the clash of civilizations’, the dominant narrative quickly became one of mutual antagonism, in which both religions were positioned as irreconcilably foundational in major global conflicts. As is often the case in such moments of heated contention, it was easy to overlook the counterintuitive fact that, in various parts of the world, especially in those communities where adherents of both faiths have lived in close proximity, there has always been a direct sharing and transfer of experiences in religious practices and evangelizing stratagems. Such ‘spiritual economies’ (cf. Rudnyckyj 2010) do not imply that theological differences are erased; they suggest, rather, that competing faiths, in their attempts to expand and preserve themselves, frequently cross boundaries to appropriate the other's devotional and conversionary strategies.
Does Participation Reinforce Patronage? Policy Preferences, Turnout and Class in Urban Ghana
Authors: Nathan Noah L.
Published: October 2016

Political competition is expected to become less particularistic as prosperity rises and a middle class emerges. But particularistic linkages persist despite rising wealth in urban Ghana. Politicians are unable to commit to campaign promises with voters who want large-scale public policies, many of whom are in the middle class. This creates incentives to avoid mobilizing many of these voters and to ignore their preferences. As a result, voters who want major public policies rather than patronage differentially refrain from participation, allowing poorer voters to dominate the electorate and party organizations. This may only reinforce politicians’ disincentives to make policy appeals, and stall the emergence of more policy-based electoral competition even as the middle class grows.
Therapeutic effect of Castellani's paint in patients with an itchy ear canal
Authors: Babakurban S Turkoglu , Topal O , Aydin E , Hizal E , Copur S , Ekici M Demirbilek
Published: October 2016

Objective:

To examine the effects of Castellani's paint on symptomatic relief and skin flora in patients with an itchy external ear canal.

Methods:

Subjective pruritus scores, and erythema and desquamation scores, were noted in 61 patients with an itchy external ear canal. External ear canal skin swabs were taken for bacterial and fungal cultures. Patients were then randomly divided into three groups: either Castellani's paint (group one) or steroid ear drops (group two) were instilled, or non-impacted cerumen was removed (group three). Patients were re-assessed at one month after the initial visit.

Results:

After treatment, subjective pruritus scores were significantly lower in all groups, erythema scores were significantly decreased in group one, and desquamation scores were significantly reduced in groups one and two, when compared with pre-treatment scores. Reproduction density of bacteria including normal flora was decreased in group one. However, the types of bacteria that constitute the normal flora of the external ear canal were unchanged.

Conclusion:

Castellani's paint can be administered safely, effectively and easily, without affecting the type of external ear canal skin bacteria, in patients with an itchy external ear canal.
Clinical and histopathological prognostic factors in locoregional advanced laryngeal cancer
Authors: Santos T S , Estêvão R , Antunes L , Certal V , Silva J C , Monteiro E
Published: October 2016

Objective:

To evaluate the clinical and histopathological factors affecting the prognosis of patients with squamous cell locoregional advanced laryngeal cancer.

Methods:

A retrospective chart review was conducted of 121 patients with locoregional advanced laryngeal cancer, primarily treated with surgery from 2007 to 2011. Disease-free survival and overall survival rates were analysed as oncological outcomes. Prognostic variables, namely gender, pharyngeal invasion, pathological assessment of tumour and nodal stage, adjuvant therapy, margin status, nodal extracapsular extension, tumour differentiation, lymphovascular and perineural invasion, and predominant growth pattern, were also analysed.

Results:

One-year and three-year disease-free survival rates were 81.3 per cent and 63.5 per cent, respectively. One-year and three-year overall survival rates were 88.3 per cent and 61.4 per cent, respectively. Multivariate analysis showed that nodal extracapsular extension (p< 0.05) and an infiltrative growth pattern (p< 0.05) were associated with disease progression. Nodal extracapsular extension (p< 0.05) was associated with higher mortality.

Conclusion:

Nodal extracapsular extension and an infiltrative growth pattern were the main prognostic factors in locoregional advanced laryngeal cancer. The presence of pharyngeal invasion, pathologically confirmed node-positive stage 2–3 disease, close or microscopic positive margins, and lymphovascular and perineural invasion have a negative impact on prognosis.
Tracheal T-tube: a novel endoscopic insertion technique
Authors: Rahimah A Nor , Shahfi F I , Masaany M , Gazali N , Siti S H
Published: October 2016

Background:

Laryngotracheal stenosis is a complex condition of airway compromise involving either the larynx or trachea, or both.

Objectives:

This paper describes a new method of endoscopically inserting a silicone tracheal T-tube as treatment for laryngotracheal stenosis. The advantages of this method over previously described methods are discussed.
Post-tonsillectomy dietary advice: systematic review
Authors: Millington A J F , Gaunt A C , Phillips J S
Published: October 2016

Objective:

To determine if there is evidence that post-tonsillectomy dietary advice affects post-operative morbidity.

Method:

A systematic review was conducted of Embase, Medline, the Cumulative Index to Nursing and Allied Health Literature and PsycInfo, to November 2014.

Results:

Seventeen articles were included; their heterogeneous nature prevented meta-analysis. Of these, all three small, randomised studies showed no statistical difference in morbidity between restricted and non-restricted diets.

Conclusion:

Most post-tonsillectomy dietary advice is based on historical anecdotes and not rigorous scientific testing. The existing small-scale, randomised studies show no statistical difference in morbidity between non-restricted and restricted diets.
Critiquing the Bank: 60 Years of BNDES in the Academy
Authors: HANLEY ANNE G. , PIRES JULIO MANUEL , DE SOUZA MAURÍCIO JORGE PINTO , MARCONDES RENATO LEITE , DE FARIA ROSANE NUNES , SAKURAI SÉRGIO NARUHIKO
Published: October 2016

This article offers a critical analysis of scholarship produced about Brazil's Banco Nacional de Desenvolvimento Econômico e Social (BNDES) since its founding, in 1952, to 2013. BNDES has performed an important, if changing and sometimes controversial, role in Brazil's economic development over the past 60 years, especially as provider of long-term finance. This analysis of almost 1,000 texts highlights discussions about its initial organisation and mission and how the role and activities of the bank changed over time, guided by turbulent national political and economic contexts. In spite of the bank's institutional importance, however, the literature is more narrative than analytical and of limited scholarly impact, dominated as it is by the bank's authorship. We argue for independent, evidence-driven, critical analyses of the effectiveness of this important institution in promoting Brazil's economic and social development.
Interplay of hippocampal volume and hypothalamus-pituitary-adrenal axis function as markers of stress vulnerability in men at ultra-high risk for psychosis
Authors: Pruessner M. , Bechard-Evans L. , Pira S. , Joober R. , Collins D. L. , Pruessner J. C. , Malla A. K.
Published: October 2016

Background

Altered hypothalamus-pituitary-adrenal (HPA) axis function and reduced hippocampal volume (HV) are established correlates of stress vulnerability. We have previously shown an attenuated cortisol awakening response (CAR) and associations with HV specifically in male first-episode psychosis patients. Findings in individuals at ultra-high risk (UHR) for psychosis regarding these neurobiological markers are inconsistent, and assessment of their interplay, accounting for sex differences, could explain incongruent results.

Method

Study participants were 42 antipsychotic-naive UHR subjects (24 men) and 46 healthy community controls (23 men). Saliva samples for the assessment of CAR were collected at 0, 30 and 60 min after awakening. HV was determined from high-resolution structural magnetic resonance imaging scans using a semi-automatic segmentation protocol.

Results

Cortisol measures and HV were not significantly different between UHR subjects and controls in total, but repeated-measures multivariate regression analyses revealed reduced cortisol levels 60 min after awakening and smaller left HV in male UHR individuals. In UHR participants only, smaller left and right HV was significantly correlated with a smaller total CAR (ρ = 0.42, p = 0.036 and ρ = 0.44, p = 0.029, respectively), corresponding to 18% and 19% of shared variance (medium effect size).

Conclusions

Our findings suggest that HV reduction in individuals at UHR for psychosis is specific to men and linked to reduced post-awakening cortisol concentrations. Abnormalities in the neuroendocrine circuitry modulating stress vulnerability specifically in male UHR subjects might explain increased psychosis risk and disadvantageous illness outcomes in men compared to women.