bluuebunny/crossref_metadata_2025 huggingface dataset:
Reproduction of Lake Trout Morphotypes at Isle Royale in Northern Lake Superior
Authors: Goetz Frederick , Sitar Shawn , Jasonowicz Andy , Seider Michael
Published: January 2017

The reproductive biology of male and female lean, siscowet, redfin, and humper Lake Trout Salvelinus namaycush was assessed by measuring the gonadosomatic index (GSI) and by histological analysis of the gonads over 2 years from spring to fall at sites surrounding Isle Royale National Park, Lake Superior. Whole livers, otoliths, and ovaries were also collected to measure hepatosomatic index (HSI), age, and fecundity. In general, GSIs increased from spring to summer in male and female siscowets, leans, redfins, and humpers, and this was accompanied by a large increase in the number of vitellogenic (>2.0 mm) follicles in females. Postspawned ovaries and regressing testes were predominant in all morphotypes by October but were also observed in September, indicating that some spawning occurred at least by September. Further, preovulatory siscowet females (GSIs > 10) and siscowet males with fully mature and even regressing testes were observed in the spring and summer, indicating that spawning occurs at least in the spring and fall in siscowets at Isle Royale. For all morphotypes, average male HSIs were significantly lower than female HSIs. Absolute fecundity was positively related to size and age for all morphotypes. Humpers had the lowest absolute fecundity. Leans, redfins, and siscowets had similar fecundity relationships. The results conclusively demonstrate that deepwater siscowet Lake Trout reproduce at least during the spring and fall at Isle Royale and that leans, humpers, and redfins reproduce during the fall. In lakes that exhibit sympatric populations of deepwater and shallow‐water ecotypes of Arctic Char Salvelinus alpinus, the deepwater form also spawns in both spring and fall. Our data and those on Arctic Char suggest that there is an adaptive strategy for maintaining alternative spawning times in the deepwater ecotypes in these populations.

Received June 20, 2016; accepted November 2, 2016 Published online January 31, 2017
Overview of ultrasonic shot peening
Authors: Yin Fei , Rakita Milan , Hu Shan , Han Qingyou
Published: January 2017

Ultrasonic shot peening (USP) is acknowledged as an effective surface treatment method to enhance the mechanical performance of materials by inducing compressive residual stress in solid metals and alloys. This article overviews recent researches from our group at Purdue University on the USP in the aspects of modelling the kinetics of the shots, predicting the surface topography of the peened samples and producing the nanostructured grains on the solid metals and alloys. Research results suggest that finite element method and the developed calculation algorithm can be used for the surface morphology prediction and the USP is capable of surface nanocrystallisation and grain refinement on solid metals. For instance, the topic of the biological enhancement for metallic bio-implant materials via the USP was discussed as well according to our preliminary investigations. The related researches in these topics are discussed and some possible addresses for future study in these fields are drawn and underlined.
Price Asymmetry in the U.S. Pork Marketing Channel
Authors: Boyd Milton S. , Brorsen B. Wade
Published: January 2017

This paper tests the existence of price asymmetry within the U.S. pork marketing channel using an asymmetric pricing model. Asymmetry is tested both for the sum of price adjustments and the speed of price adjustments. Results show that wholesale (packer) prices respond similarly to farm price decreases and increases. Also, there is no significant difference between retailers' response to wholesale price increases and their response to wholesale price decreases.
Radiation hydrodynamic simulations of a super-Eddington accretor as a model for ultra-luminous sources
Authors: Ogawa Takumi , Mineshige Shin , Kawashima Tomohisa , Ohsuga Ken , Hashizume Katsuya
Published: January 2017

We perform two-dimensional radiation hydrodynamic (RHD) simulations of super-Eddington accretion flow and the accompanying outflow to investigate how they will be observed from various viewing directions. We consider gas flow around a 10 M⊙ black hole for mass injection rates of $\skew4\dot{M}_{\rm inj}/{\skew4\dot{M}_{\rm Edd}}=10^{2}$, 103, and 104 (in units of $\dot{M}_{\rm Edd}\equiv L_{\rm Edd}/c^2$, with LEdd and c being the Eddington luminosity and the speed of light, respectively), and solve gas dynamics and radiation transfer around the black hole, taking into account inverse Compton scattering. We confirm the tendency that the higher the mass accretion rate is, the larger the relative importance of outflow over accretion flow becomes. The observational appearance of the super-Eddington flow is distinct, depending on whether it is viewed from the edge-on direction or from the face-on direction. This is because nearly edge-on observers can only see the outer, cooler (∼106 K) surface of the inner, vertically inflated part of the flow. Observational properties are briefly discussed in the context of the ultra-luminous X-ray sources (ULXs), the extreme ULXs (E-ULXs), and the ultra-luminous supersoft sources (ULSs). We find that the extremely high luminosities of E-ULXs (L ∼ 1041 erg s−1) can be explained when the flow on to the black hole with ≳20 M⊙ with a very high accretion rate, ${\dot{m}}_{\,\rm acc} (\equiv {{\dot{M}}_{\,\rm acc}/ {\dot{M}}_{\,\rm Edd}}) \gtrsim {10^{3}}$, is observed from the nearly face-on direction. The high luminosity (∼1039 erg s−1) and the very soft blackbody-like spectra with temperatures around 0.1 keV, which are observed in the ULSs, can be explained if the super-Eddington flow with ${\dot{m}}_{\rm acc} \sim 10^{2}$–103 is viewed from large viewing angles, θ ≳ 30°.
The translation elongation cycle—capturing multiple states by cryo-electron microscopy
Authors: Frank Joachim
Published: January 2017

During the work cycle of elongation, the ribosome, a molecular machine of vast complexity, exists in a large number of states distinguished by constellation of its subunits, its subunit domains and binding partners. Single-particle cryogenic electron microscopy (cryo-EM), developed over the past 40 years, is uniquely suited to determine the structure of molecular machines in their native states. With the emergence, 10 years ago, of unsupervised clustering techniques in the analysis of single-particle data, it has been possible to determine multiple structures from a sample containing ribosomes equilibrating in different thermally accessible states. In addition, recent advances in detector technology have made it possible to reach near-atomic resolution for some of these states. With these capabilities, single-particle cryo-EM has been at the forefront of exploring ribosome dynamics during its functional cycle, along with single-molecule fluorescence resonance energy transfer and molecular dynamics computations, offering insights into molecular architecture uniquely honed by evolution to capitalize on thermal energy in the ambient environment.

This article is part of the themed issue ‘Perspectives on the ribosome’.
A recent intermezzo at the Ribosome Club
Authors: Pavlov Michael Y. , Liljas Anders , Ehrenberg Måns
Published: January 2017

Two sets of ribosome structures have recently led to two different interpretations of what limits the accuracy of codon translation by transfer RNAs. In this review, inspired by this intermezzo at the Ribosome Club, we briefly discuss accuracy amplification by energy driven proofreading and its implementation in genetic code translation. We further discuss general ways by which the monitoring bases of 16S rRNA may enhance the ultimate accuracy (
d
-values) and how the codon translation accuracy is reduced by the actions of Mg
2+
ions and the presence of error inducing aminoglycoside antibiotics. We demonstrate that complete freezing-in of cognate-like tautomeric states of ribosome-bound nucleotide bases in transfer RNA or messenger RNA is not compatible with recent experiments on initial codon selection by transfer RNA in ternary complex with elongation factor Tu and GTP. From these considerations, we suggest that the sets of 30S subunit structures from the Ramakrishnan group and 70S structures from the Yusupov/Yusupova group may, after all, reflect two sides of the same coin and how the structurally based intermezzo at the Ribosome Club may be resolved simply by taking the dynamic aspects of ribosome function into account.

This article is part of the themed issue ‘Perspectives on the ribosome’.
Application of the particle swarm optimization method for the analysis of wide-angle X-ray diffraction curves of semicrystalline polymers
Authors: Rabiej Małgorzata
Published: January 2017

The analysis of wide-angle X-ray diffraction curves of semicrystalline polymers is connected with a thorough decomposition of these curves into crystalline peaks and amorphous components. A reliable and unambiguous decomposition is the most important step in calculation of the crystallinity of polymers. This work presents a new algorithm dedicated to this aim, which is based on the particle swarm optimization (PSO) method. The PSO method is one of the most effective optimization techniques that employs a random choice as a tool for going through the solution space and searching for the global solution. The action of the PSO algorithm imitates the behaviour of a bird flock or a fish school. In the system elaborated in this work the original PSO algorithm has been equipped with several heuristics. The role of heuristics is performed by procedures which orient the search of the solution space using additional information. In this paper it is shown that this algorithm is faster to converge and more efficiently performs a multi-criterial optimization compared with other algorithms used for this purpose to date.
Nondestructive separation of residual stress and composition gradients in thin films by angle- and energy-dispersive X-ray diffraction. II. Experimental validation
Authors: Klaus Manuela , Genzel Christoph , García José
Published: January 2017

The different approaches for separating residual stress and composition gradients introduced in the first part of this series [Klaus & Genzel (2017). J. Appl. Cryst.
50, 252–264] are demonstrated with the experimental example of a graded Ti(C,N) coating layer deposited by a modified high-temperature chemical vapour deposition process on a cemented carbide substrate. The coating layer features a depth gradient in the lattice parameter d_{\psi ^*}^{hkl} in the strain-free direction of the biaxial stress state, ψ*,hkl
, and tensile residual stresses σ|| which are nearly uniform over the coating thickness but drop down significantly towards the free surface. On the assumption that the out-of-plane stress component σ33 can be neglected, the d_{\psi ^*}^{hkl} gradient is related to the variation in the chemical composition with depth. Therefore, the example considered here corresponds to case (d) of possible combinations of residual stress and composition gradients discussed in the first part of this series. The comparison of the results achieved by means of the different methods reveals the importance of choosing appropriate experimental conditions that fit best to the sample to be investigated. For the case of thin-film analysis, it is shown that the X-ray information depth is the crucial parameter which should match the film thickness.
Crystallization and X-ray crystallographic analysis of recombinant TylP, a putative γ-butyrolactone receptor protein fromStreptomyces fradiae
Authors: Mohd-Sharif Nurhikmah , Shaibullah Sofiyah , Givajothi Vasanthakumar , Tan Cheng-Seng , Ho Kok Lian , Teh Aik-Hong , Baharum Syarul Nataqain , Waterman Jitka , Ng Chyan Leong
Published: January 2017

TylP is one of five regulatory proteins involved in the regulation of antibiotic (tylosin) production, morphological and physiological differentiation inStreptomyces fradiae. Its function is similar to those of various γ-butyrolactone receptor proteins. In this report, N-terminally His-tagged recombinant TylP protein (rTylP) was overproduced inEscherichia coliand purified to homogeneity. The rTylP protein was crystallized from a reservoir solution comprising 34%(v/v) ethylene glycol and 5%(v/v) glycerol. The protein crystals diffracted X-rays to 3.05 Å resolution and belonged to the trigonal space groupP3121, with unit-cell parametersa=b= 126.62,c= 95.63 Å.
Crystal structures ofN2,N3,N5,N6-tetrakis(pyridin-2-ylmethyl)pyrazine-2,3,5,6-tetracarboxamide andN2,N3,N5,N6-tetrakis(pyridin-4-ylmethyl)pyrazine-2,3,5,6-tetracarboxamide
Authors: Cati Dilovan S. , Stoeckli-Evans Helen
Published: January 2017

The title compounds, C32H28N10O4· unknown solvent, (I), and C32H28N10O4, (II), are pyrazine-2,3,5,6-tetracarboxamide derivatives. In (I), the substituents are (pyridin-2-ylmethyl)carboxamide, while in (II), the substituents are (pyridin-4-ylmethyl)carboxamide. Both compounds crystallize in the monoclinic space groupP21/n, withZ′ = 1 for (I), andZ′ = 0.5 for (II). The whole molecule of (II) is generated by inversion symmetry, the pyrazine ring being situated about a center of inversion. In (I), the four pyridine rings are inclined to the pyrazine ring by 83.9 (2), 82.16 (18), 82.73 (19) and 17.65 (19)°. This last dihedral angle involves a pyridine ring that is linked to the adjacent carboxamide O atom by an intramolecular C—H...O hydrogen bond. In compound (II), the unique pyridine rings are inclined to the pyrazine ring by 33.3 (3) and 81.71 (10)°. There are two symmetrical intramolecular C—H...O hydrogen bonds present in (II). In the crystal of (I), molecules are linked by N—H...O and N—H...N hydrogen bonds, forming layers parallel to (10-1). The layers are linked by C—H...O and C—H...N hydrogen bonds, forming a three-dimensional framework. In the crystal of (II), molecules are linked by N—H...N hydrogen bonds, forming chains propagating along the [010] direction. The chains are linked by a weaker N—H...N hydrogen bond, forming layers parallel to the (101) plane, which are in turn linked by C—H...O hydrogen bonds, forming a three-dimensional structure. In the crystal of compound (I), a region of disordered electron density was treated with the SQUEEZE routine inPLATON[Spek (2015).Acta Cryst. C71, 9–18]. Their contribution was not taken into account during refinement. In compound (II), one of the pyridine rings is positionally disordered, and the refined occupancy ratio for the disordered Car—Car—Npyatoms is 0.58 (3):0.42 (3).
Crystal structures of 2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]-N-(naphthalen-1-yl)acetamide and 2-[(4,6-diaminopyrimidin-2-yl)sulfanyl]-N-(4-fluorophenyl)acetamide
Authors: Subasri S. , Kumar Timiri Ajay , Sinha Barij Nayan , Jayaprakash Venkatesan , Viswanathan Vijayan , Velmurugan Devadasan
Published: January 2017

The title compounds, C16H15N5OS, (I), and C12H12FN5OS, (II), are [(diaminopyrimidine)sulfanyl]acetamide derivatives. In (I), the pyrimidine ring is inclined to the naphthalene ring system by 55.5 (1)°, while in (II), the pyrimidine ring is inclined to the benzene ring by 58.93 (8)°. In (II), there is an intramolecular N—H...N hydrogen bond and a short C—H...O contact. In the crystals of (I) and (II), molecules are linked by pairs of N—H...N hydrogen bonds, forming inversion dimers withR22(8) ring motifs. In the crystal of (I), the dimers are linked by bifurcated N—H...(O,O) and C—H...O hydrogen bonds, forming layers parallel to (100). In the crystal of (II), the dimers are linked by N—H...O hydrogen bonds, also forming layers parallel to (100). The layers are linked by C—H...F hydrogen bonds, forming a three-dimensional architecture.
Drops forming in inkjet printing of flexible electronic circuits
Authors: Tomaszewski Grzegorz , Potencki Jerzy
Published: January 2017

Purpose

This paper aims to study drop formation in piezoelectric industrial printheads during the inkjet printing processes. It presents how the piezoelectric printhead forms drops of nanoparticle ink and how the problems with different values of drop parameters may influence the printed pattern’ defects and quality.

Design/methodology/approach

A piezoelectric printhead with 128 nozzles was activated to operate in a controlled manner, and the droplets ejected from the nozzles were observed during falling and analysed in the printview system. The effect of varying the values of drop parameters on print quality and pattern defects has been analysed and discussed.

Findings

The obtained results allow the identification of the sources of the technological problems in obtaining repeatable performance drops with the desired properties, and indicate the importance of choosing the appropriate individually chosen strategy of controlling the printing for each individual application to get good-quality and free-from-defects patterns.

Research limitations/implications

Because of the chosen research method (arbitrary selected printhead type and ink manufacturer), this study could have limited universality. Authors encourage the study of other kinds of piezoelectric heads or other conductive inks.

Practical implications

This study includes practically useful applications for users to improve the inkjet print quality.

Originality/value

This study presents results of original empirical research works on problems of the drops forming in the inkjet printing process, and finally, it identifies problems that must be resolved to disseminate this technology.
Making the sale
Authors: Fox Robert
Published: January 2017

Purpose

This study aims to explore the use of the conversion rate metric as well as A/B testing which is complimentary to that measurement for the improvement of exposing and increasing usage of library digital services.

Design/methodology/approach

This column is a viewpoint piece. A literature search was performed as well as ideas from cited books.

Findings

There are no findings to speak of.

Originality/value

The use of certain marketing techniques such as the conversion rate and the use of user experience testing such as A/B analysis has the potential to increase the ability of libraries to objectively measure the impact of their online services and increase the efficacy of those services.
Positioning and change in a hospital ward
Authors: Kjaerbeck Susanne
Published: January 2017

Purpose

This paper focuses on communication about hygiene in a hospital ward and with the relevant infection control organization. The purpose of this paper is to examine the function of the hygiene coordinator as a key change agent and the communicative challenges and role conflicts implied in her practice. The author suggests strategies for improving communication on hygiene on ward level.

Design/methodology/approach

The empirical material consists of interviews and recordings of communicative events in relation to a breakout of dangerous bacteria in the ward. Change communication is used as a contextualizing frame of understanding, and positioning theory and analysis are applied to shed light upon the core challenges of communicating as a change agent when the coordinator’s professional position and collegial relations do not support it.

Findings

It is shown how these challenges are connected to positional dilemmas regarding professional hierarchies and collegial relations. In order to have the hygiene coordinator gain authority and achieve empowerment in her function, additional documentation and training are needed, and communication efforts between the department management and the hygiene coordinator need strengthening. Furthermore, the hygiene area should be connected to the hospital’s overarching purpose of saving lives.

Originality/value

These findings point to the importance of taking communication on the departmental level into consideration in relation to change strategies, and they highlight the centrality of strategic positioning practices in a work environment which is organized in professional groups and according to distributed responsibilities.
Strategy development through interview technique from narrative therapy
Authors: Kryger Anders
Published: January 2017

Purpose

The purpose of this paper is to demonstrate the successful strategy formulation process of a new purchasing department at an international engineering group.

Design/methodology/approach

The strategy formulation was co-created by the department manager and employees at a storytelling workshop, facilitated with interview technique from narrative therapy, and later authorized by the business area director. The organizational intervention preceded the scholarly inquiry.

Findings

Employees’ retrospective storytelling about working at the company enabled them to formulate a joint mission statement using words and expressions from their own stories. Prospective storytelling enabled them to formulate a joint medium- and long-term vision and a corresponding action plan. This paper proposes interview technique from narrative therapy as a new practice-oriented strategic management tool and calls for further experimentation in rethinking best practices in strategy development.

Originality/value

Introducing narrative therapy interview technique in an organizational context is valuable because it may facilitate affinity of employees to strategy through storytelling thus contributing to contextualized strategy formulation and paving the way for subsequent implementation. This “from practice to research” approach can serve as inspiration for action researchers interested in driving organizational change.
Strategic renewal in times of environmental scarcity
Authors: Al Humaidan Saleh , Sabatier Valerie
Published: January 2017

Purpose

The purpose of this paper is to analyze how strategic renewal occurs in large incumbent newspaper companies facing a specific context of environment scarcity (i.e. environmental dissolution (the market gradually changing in size and scope)). Within the media industry, the Kingdom of Saudi Arabia (KSA) offers a particularly interesting research setting because the number of competitors in the regional market is regulated by the government; consequently, the incumbent firms face the same local environment. This situation offers the possibility to shed light on how the orientation of the top management team (TMT) of the firm influences the strategic renewal and the traditional business model of the firm.

Design/methodology/approach

The strategic renewal of the three largest incumbents of the print newspapers in KSA over 12 years (from 2000 to 2012) was analyzed with a qualitative approach (archival data and 30 interviews with the TMTs of each company and with external observers). A two-step analysis of within-case analysis and cross-case analysis was used.

Findings

Building on Schmittet al.’s (2016) framework, it was empirically found that depending on the orientation of the TMT, the managerial perception of the firm’s environment within the same scarcity situation leads to different strategic renewal responses. The findings demonstrate that internally oriented TMTs engage in incremental business model changes, while externally oriented TMTs engage in disruptive business model changes. However, management’s attitude toward technology has been neglected in the literature so far, and it was concluded that technology plays a mediating role in strategy renewal.

Research limitations/implications

Recent research on strategic renewal in times of environmental scarcity has built on both population ecology and strategic choice literatures and has argued that varying CEO perceptions can lead to very different strategic responses. Other research on business models has started to explore the role of technology in business model evolution. In the context of environmental dissolution, it can be argued that the attitude of the TMT toward technology has a mediating role in business model evolution.

Practical implications

In times of environmental dissolution – the traditional market of the firm changes not only in size but also in scope – strategic renewal is conditioned by the orientation of the TMT and its attitude toward technology. When the traditional business model of the firm is put under pressure by such changes, teams with an external orientation or an appetite for technology will be more likely able to engage in business model disruption.

Originality/value

The authors have had the opportunity to conduct case studies on three large newspapers companies in a country where the regulation is very strong and press freedom is not comparable to other European or North-American countries.
Predators regulate prey species sorting and spatial distribution in microbial landscapes
Authors: Livingston George , Fukumori Kayoko , Provete Diogo B. , Kawachi Masanobu , Takamura Noriko , Leibold Mathew A.
Published: January 2017

The role of predation in determining the metacommunity assembly model of prey communities is understudied relative to that of interspecific competition among prey. Previous work on metacommunity dynamics of competing species has shown that sorting by habitat patch type and spatial patterning can be affected by disturbances.

Microcosms offer a useful model system to test the effect of multi‐trophic interactions and disturbance on metacommunity dynamics. Here, we investigated the potential role of predators in enhancing or disrupting sorting and spatial pattern among prey in experimental landscapes.

We exposed multi‐trophic protist microcosm landscapes with one predator, two competing prey, two patch resource types, and localized dispersal to three disturbance regimes (none, low, and high). Then, we used variation partitioning and spatial clustering analysis to analyse the results.

In contrast with previous experiments that did not manipulate predators, we found that patch type did not structure prey communities very well. Instead, we found that it was the distribution of the predator that most strongly predicted the composition of the prey community.

The predator impacted species sorting by (1) preferentially consuming one prey, thereby acting as a strong local environmental driver, and by (2) indirectly magnifying the impact of patch food resources on the less preferred prey. The predator also enhanced spatial signal in the prey community because of its limited dispersal.

Our results indicate that predators can strongly influence prey species sorting and spatial patterning in metacommunities in ways that would otherwise be attributed to stochastic effects, such as dispersal limitation or demographic drift. Therefore, whenever possible, predators should be explicitly included as separate explanatory factors in variation partitioning analyses.
Stoichiometry of Prochlorococcus, Synechococcus, and small eukaryotic populations in the western North Atlantic Ocean
Authors: Baer Steven E. , Lomas Michael W. , Terpis Kristina X. , Mouginot Céline , Martiny Adam C.
Published: January 2017

In the North Atlantic Ocean, we found that natural populations of Prochlorococcus adhered to Redfield ratio dimensions when comparing cell quotas of carbon to nitrogen, but had flexible composition under nutrient and light stress, allowing for a broad range of cellular carbon‐ and nitrogen‐to‐phosphorus ratios. Synechococcus populations also exhibited a wide range of elemental stoichiometry, including carbon‐to‐nitrogen ratios and increased their carbon‐to‐phosphorus ratios in response to low dissolved phosphorus availability. Small eukaryotic populations tended to have lower carbon‐to‐phosphorus ratios than single cell cyanobacterial groups, with the exception of one group of samples, which highlights the importance of community composition when determining how biological diversity influences bulk particle stoichiometry. The ratio of dissolved nitrogen:phosphorus fluxes into the euphotic zone was not correlated to nitrogen:phosphorus cellular quotas. The lack of a homeostatic relationship implies that other mechanisms, such as species‐specific adaptation to oligotrophic phosphorus concentrations, control elemental particle ratios.
Outcomes of preoperative biliary drainage from a single tertiary center: Is there still a role for plastic stents?
Authors: Ma Michael Xiang , Chin Marcus Woon Soon , Jennings Melissa , Siah Chiang , Edmunds Simon
Published: January 2017

OBJECTIVES

Preoperative biliary drainage (PBD) can relieve symptoms of cholestasis, but carries risk of procedural complications. Metal stents have wider lumens and longer patency, although plastic stents (PS) remain in use. We reviewed the outcomes after PBD in patients with cholestasis.

METHODS

Patients with symptomatic cholestasis who were likely to wait for over 2 weeks before surgery and were thus treated with PBD between January 2011 and May 2015 were included. Patients were evaluated for stenting‐related complications, time interval to surgery, resection rate, improvement in bilirubin level and surgical complications.

RESULTS

Forty patients underwent PBD by endoscopic retrograde cholangiopancreatography (ERCP). Of these, 36 patients received the placement of PS, one received a metal stent and the remaining three required percutaneous drainage due to unsuccessful biliary cannulation. Serum bilirubin declined from 172 μmol/L (baseline) to 14 μmol/L at 30 days (P < 0.0001). Median time interval from ERCP to surgery in all patients was 5 weeks (range 2–36 weeks). Preoperative stenting‐related complications occurred in seven patients after a median of 3 weeks (range 1–6 weeks). Median time to surgery was similar in patients with and without stenting‐related complications (5 weeks vs 4 weeks, respectively, P = 0.33). Surgery was completed in 32 (80%) patients, with a post‐Whipple complication rate of 53%.

CONCLUSIONS

PBD using mostly PS was effective in reducing bilirubin levels and did not detrimentally affect time interval to surgery. Median time interval to stenting‐related complication occurred after 3 weeks, suggesting PS may be most useful for short‐term PBD.
Gamma Knife radiosurgery for brain metastases from gastrointestinal primary
Authors: Page Brandi R , Wang Edina C , White Lance , McTyre Emory , Peiffer Ann , Alistar Angela , Mu Frank , Loganathan Amritraj , Bourland John Daniel , Laxton Adrian W , Tatter Stephen B , Chan Michael D
Published: January 2017

Introduction

In this study, we assessed clinical outcomes of patients with brain metastases from a gastrointestinal (GI) primary cancer and patterns of failure after stereotactic radiosurgery including failure within the radiosurgical volume, distant failure and leptomeningeal failure (LMF). We also assessed other factors associated with the patients’ neurologic and extraneuraxial disease that may affect clinical outcomes.

Methods

We reviewed our institutional series of 62 consecutive patients with brain metastases treated with stereotactic radiosurgery, which included 17 patients with oesophageal, 44 patients with colorectal and one patient with anal canal primary. The median marginal dose to the radiosurgery volume was 17 Gy (range 10–24 Gy). Thirteen patients were treated with whole‐brain radiotherapy (WBRT) prior to GKS.

Results

The median dose delivered to the margin of the tumour was 17 Gy (range: 10–24 Gy). The median largest tumour diameter was 2.7 cm (range: 0.60–6.1 cm). The median overall survival (OS) was 7.1 months with a median follow‐up of 6.1 months and a range of 0–31.7 months. Freedom from local failure was 86.5% and 62.2% at 6 and 12 months respectively. Freedom from distant failure was 73.2% and 42.2% at 6 and 12 months, respectively, and 40% of patients died of neurologic death. LMF occurred in seven patients, all of whom had colorectal primaries. Multivariate analysis revealed that craniotomy for resection of brain metastasis (HR = 2.63, P < 0.02), an absence of extracranial disease (HR = 2.28, P < 0.03), and prolonged time to distant brain failure (HR = 2.85, P < 0.01) predicted for improved survival.

Conclusions

Colorectal cancer metastases tend to have a higher rate of leptomeningeal failure than other types of GI cancer metastases. Radiosurgical management of brain metastases from GI primary represents an acceptable management option. Neurologic death remains problematic.
Lipopolysaccharide promotes the development of murine endometriosis‐like lesions via the nuclear factor‐kappa B pathway
Authors: Azuma Yukihiro , Taniguchi Fuminori , Nakamura Kazuomi , Nagira Kei , Khine Yin Mon , Kiyama Tomoiki , Uegaki Takashi , Izawa Masao , Harada Tasuku
Published: January 2017

Problem

Is lipopolysaccharide (LPS) involved in the development of endometriosis?

Method of Study

BALB/c mice (n=69) were used for the murine endometriosis model. Mice with surgically induced endometriosis were injected with LPS intraperitoneally. After 4 weeks of LPS injections with or without the nuclear factor‐kappa B (NF‐κB) inhibitor, the extent of endometriosis‐like lesions was evaluated. Expression of inflammatory factors in the implants was evaluated using real‐time RT‐PCR. Cell proliferation, angiogenic activity, inflammation, and NF‐κB phosphorylation were assessed by immunohistochemical staining.

Results

Lipopolysaccharide increased total number, size, and mRNA expression of Ptgs‐2, Vegf, Ccl‐2, and Il‐6 in endometriosis‐like lesions. LPS also increased the percentage of Ki67‐positive cells and enhanced the intensity and rate of positive cells of CD3, F4/80, and PECAM. Intense expression of phospho‐NF‐κB p65 after LPS administration was observed. Treatment with the NF‐kB inhibitor negated these LPS‐induced effects.

Conclusion

LPS‐induced pelvic inflammation status enhanced the development of murine endometriosis‐like lesions via NF‐κB pathway.
To Revoke or Not Revoke? The Political Determinants of Executive Order Longevity
Authors: Thrower Sharece
Published: January 2017

Though many scholars study the formation of policy, less attention is given to its endurance. In this article, I seek to determine what contributes to the longevity of policy by examining the case of presidential unilateralism. While scholars widely recognize presidents’ ability to unilaterally make policy with executive orders, they largely do not account for how these same orders can be easily changed by subsequent administrations. To address this deficiency, I develop a theory of executive order duration based on both time‐invariant characteristics of the order and time‐variant changes in the political climate it faces. Using survival analysis to examine all orders revoked between 1937 and 2013, I find support for the theory. This study has implications for understanding the endurance of executive orders and other policy instruments as part of the law as well as understanding the strategic actions of policy makers given the transient nature of these tools.
Raised faecal calprotectin is associated with subsequent symptomatic relapse, in children and adolescents with inflammatory bowel disease in clinical remission
Authors: Diederen K. , Hoekman D. R. , Leek A. , Wolters V. M. , Hummel T. Z. , de Meij T. G. , Koot B. G. P. , Tabbers M. M. , Benninga M. A. , Kindermann A.
Published: January 2017

Background

Reliable data on inflammatory biomarkers for predicting relapse of paediatric inflammatory bowel disease (IBD) are lacking.

Aim

To investigate the predictive value of faecal calprotectin (FC) and CRP for symptomatic relapse in pediatric IBD in clinical remission.

Methods

In this cross‐sectional cohort study, patients <18 years with Crohn's disease or ulcerative colitis in clinical remission ≥3 months were included. At baseline, clinical and biochemical disease activity were assessed using the abbreviated‐Pediatric Crohn's Disease Activity Index or Pediatric Ulcerative Colitis Activity Index, and FC and CRP respectively. Disease course over the subsequent 12 months was retrospectively assessed.

Results

In total, 114 patients (56% males; median age 14.9 years) were included. Baseline FC was higher in patients that developed symptomatic relapse [median (IQR), relapse 370 μg/g (86–1100) vs. remission 122 μg/g (40–344), P = 0.003]. Baseline FC was predictive of symptomatic relapse within 6 months [HR per 250 μg/g (95% CI): 1.46 (1.21–1.77), P < 0.001], with good predictive accuracy (AUC: 0.82). Optimal FC cut‐off was 350 μg/g, with positive and negative predictive value of 41% and 96%. Baseline CRP was higher in patients that developed symptomatic relapse [median (IQR), relapse 1.0 μg/g (0.6–5.0) vs. remission 1.0 μg/g (0.4–2.0), P = 0.033]. Baseline CRP was predictive of symptomatic relapse within 6 months from baseline [HR per 1 mg/L (95% CI): 1.10 (1.02–1.19), P = 0.011], with fair predictive accuracy (AUC: 0.72). Optimal CRP cut‐off was 1.0 mg/L, with positive and negative predictive value of 21% and 94%.

Conclusions

Faecal calprotectin and CRP are predictive of symptomatic relapse and may be valuable in management of paediatric IBD in clinical remission.
Population models and simulation methods: The case of the Spearman rank correlation
Authors: Astivia Oscar L. Olvera , Zumbo Bruno D.
Published: January 2017

The purpose of this paper is to highlight the importance of a population model in guiding the design and interpretation of simulation studies used to investigate the Spearman rank correlation. The Spearman rank correlation has been known for over a hundred years to applied researchers and methodologists alike and is one of the most widely used non‐parametric statistics. Still, certain misconceptions can be found, either explicitly or implicitly, in the published literature because a population definition for this statistic is rarely discussed within the social and behavioural sciences. By relying on copula distribution theory, a population model is presented for the Spearman rank correlation, and its properties are explored both theoretically and in a simulation study. Through the use of the Iman–Conover algorithm (which allows the user to specify the rank correlation as a population parameter), simulation studies from previously published articles are explored, and it is found that many of the conclusions purported in them regarding the nature of the Spearman correlation would change if the data‐generation mechanism better matched the simulation design. More specifically, issues such as small sample bias and lack of power of the t‐test and r‐to‐z Fisher transformation disappear when the rank correlation is calculated from data sampled where the rank correlation is the population parameter. A proof for the consistency of the sample estimate of the rank correlation is shown as well as the flexibility of the copula model to encompass results previously published in the mathematical literature.
Intellectual Disability and Developmental Risk: Promoting Intervention to Improve Child and Family Well‐Being
Authors: Crnic Keith A. , Neece Cameron L. , McIntyre Laura Lee , Blacher Jan , Baker Bruce L.
Published: January 2017

Initial intervention processes for children with intellectual disabilities (IDs) largely focused on direct efforts to impact core cognitive and academic deficits associated with the diagnosis. Recent research on risk processes in families of children with ID, however, has influenced new developmental system approaches to early intervention. Recent risk and resilience processes are reviewed that connect stress, family process, and the high rates of behavioral problems in children with ID that have substantial influence on child and family outcomes. These models are linked to emerging evidence‐based intervention processes that focus on strategic parent skill training and mindfulness interventions that reduce parental stress and create indirect benefits for children's behavioral competencies. A family‐focused developmental systems approach (M. J. Guralnick, 2011) is emphasized.
Principal–principal agency problems and stock price crash risk: Evidence from the split‐share structure reform in China
Authors: Sun Jian , Yuan Rongli , Cao Feng , Wang Baiqiang
Published: January 2017

Manuscript Type

Empirical

Research Question/Issue

On April 2005, the China Securities Regulatory Commission (CSRC) launched the split‐share structure reform to mitigate principal–principal agency problems. Using the reform as an exogenous shock, we examine the impact of principal–principal agency problems on stock price crash risk. Specifically, this study attempts to answer two questions: (1) Does the split‐share structure reform in China decrease stock price crash risk? (2) Is the above effect induced by the mitigation of principal–principal agency problems?

Research Findings/Insights

We find that the reform induces a significant decrease in crash risk after controlling for other predictors of crash risk, and this effect is more pronounced in firms with a higher proportion of shares held by controlling shareholders. Moreover, we find that the negative impact of the reform on stock price crash risk is more pronounced in firms with a high level of tunneling prior to the reform, which indicates that reform induces less tunneling, and adversely affects crash risk.

Theoretical/Academic Implications

This study contributes to the literature in two ways. First, this study constitutes the first effort to explore the determinants of stock price crash risk from the perspective of principal–principal agency problems. Second, this study enriches the growing literature on the economic consequences of the split‐share structure reform in China.

Practitioner/Policy Implications

We draw two important implications from our results. First, our findings highlight that regulatory intervention is an important way to enhance corporate governance. This is particularly beneficial in China, a transitional economy which may lag in terms of general protection of investors and information disclosure. Second, this study also confirms that minority shareholders and listed firms benefit from the reform. Both are crucial to the healthy development of the capital market in China.
Pigmented apocrine hamartoma of the vulva: A case report
Authors: Angelico Giuseppe , Gangemi Pietro , Caltabiano Rosario
Published: January 2017

We herein report a patient who clinically presented with a pigmented, flat plaque in the vulvar area. Histological examination showed a benign lesion mainly composed of tubular and cystic glands with apocrine differentiation. The most striking histological feature was the deposition of finely granular melanin pigment both in the epithelial cells and in the luminal surface of the glands. In addition, Melan‐A immunostaining showed the presence of numerous melanocytes within the lesion suggesting that the pigment deposition was secondary to colonization of the lesion by melanocytes. We therefore diagnosed this lesion as “pigmented apocrine hamartoma.” To the best of our knowledge only 3 cases of pigmented apocrine hamartoma have been reported in the literature so far.
Positive parenting predicts cortisol functioning six years later in young adults
Authors: Shirtcliff Elizabeth A. , Skinner Martie L. , Obasi Ezemenari M. , Haggerty Kevin P.
Published: January 2017

Research which indicates that adverse experiences influence hypothalamic‐pituitary‐adrenal (HPA) axis functioning illustrates the social environment ‘getting under the skin’. The present study extended this literature by examining whether positive social forces within the caregiving environment can also impact cortisol functioning. We conducted a prospective investigation of over 300 youth, half of whom were White and half were Black. Attachment, bonding and parental rewards for positive behaviors were observed or reported by the youth as an 8th grader. Twelve repeated measures of salivary cortisol were examined six years later when youth were young adults (mean age 20). Race differences were explored. Stronger attachment, bonding and teen‐reported positive parenting were predictive of high waking cortisol and steeper diurnal slopes six years later. This effect was nonlinear and additive, such that youth whose social contexts were characterized by the strongest attachment, bonding and rewarding parental relationships had the highest waking cortisol. When effects were moderated by race, findings were such that links of positive parenting with HPA functioning were more consistent for White than Black youth. Findings suggest that positive aspects of the caregiving environment can also ‘get under the skin’ and these effects are additive across a range of caregiving indices. These findings dovetail with an emerging literature on the powerful role of social support for shaping the body's stress response system and are interpreted as consistent with the Adaptive Calibration Model which suggests that cortisol regulation can have adaptive significance. A video abstract of this article can be viewed at: https://youtu.be/8evHXpt_TXM.
A rare cardiac tumor: Bronchogenic cyst of interatrial septum
Authors: Miwa Eriko , Tani Tomoko , Okada Yukikatsu , Furukawa Yutaka
Published: January 2017

Intracardiac bronchogenic cysts are uncommon congenital tumors, which rarely become symptomatic. We describe a rare case of bronchogenic cyst in the atrioventricular node. A 36‐year‐old man with third‐degree atrioventricular block was referred to our hospital. Transthoracic echocardiography revealed a cystic mass at the right atrial aspect of the low interatrial septum. He underwent surgical resection of the mass, and a permanent epicardium pacemaker was implanted. His postoperative course was uneventful. Microscopic examination showed a cyst surrounded by ciliated columnar epithelium and partially smooth muscle, and the histopathological diagnosis was bronchogenic cyst.
Changing views of nitrous oxide emissions from agricultural soil: key controlling processes and assessment at different spatial scales
Authors: Smith K. A.
Published: January 2017

Nitrous oxide, N2O, is the third most important of the long‐lived greenhouse gases, in terms of its contribution to global warming, and is expected to be the dominant cause of stratospheric ozone depletion this century. The concentration of N2O in the atmosphere was fairly constant until the beginning of the industrial age, but has gone up by 20% since. This is because of increased anthropogenic emissions, of which about 60% come from agricultural soil. The cause is the increased use of synthetic fertilizer nitrogen globally to meet the demands for increased production of food and biofuels. This review examines the isotopic evidence for this role of fertilizer N, the main mechanisms for microbial production of N2O in soil, the key soil physical and other variables that greatly affect the magnitude of emissions, and the spatial and temporal variation in emissions and the associated problems of measurement. The review also considers the methodology devised by the Intergovernmental Panel on Climate Change (IPCC) to enable countries to compile national inventories of their emissions, direct and indirect, that arise from anthropogenic activity related to agriculture and land use. This methodology also enables modellers to make ‘bottom‐up’ global estimates of N2O emissions. These estimates agree quite well at the global scale with ‘top‐down’ estimates based on the relation between reactive nitrogen newly introduced into agricultural ecosystems and increases in the global atmospheric concentration of N2O, but not with some recent regional‐scale emission measurements. The discrepancy may be related to problems of estimating indirect emissions. Top‐down estimates indicate that N2O emissions from crop‐based biofuels are too great to comply with national and international environmental regulations. Finally, possible future trends in emissions and possible mitigation measures are discussed.

Highlights

Evidence for increasing N2O in the atmosphere suggests it is caused by fertilizer N use.

Agreements and inconsistencies in assessments of N2O emissions are considered.

The main cause of increasing N2O is the use of synthetic N fertilizers on agricultural soil worldwide.

Indirect emissions from waters receiving leached N may be a major cause of assessment uncertainties.