bluuebunny/crossref_metadata_2025 huggingface dataset:
Additive manufacture of anti-biofouling inserts for marine applications
Authors: Leary Martin , Piola Richard , Shimeta Jeff , Toppi Steven , Mayson Scott , McMillan Matthew , Brandt Milan
Published: April 2016

Purpose

Biofouling of marine vessels results in significant operational costs, as well as the bio-security risk associated with the transport of marine pests. Biofouling is particularly rapid in sea-chest water intakes due to elevated temperatures and circulating flow. Inspection challenges are exacerbated, as sea chests are difficult to inspect and clean. This paper aims to present a method that utilises the flexibility and low-batch capabilities of additive manufacture to manufacture custom sea-chest inserts that eliminate circulating flow and increase the uniformity of shear stress distributions to enable more constant ablation of anti-biofouling coatings.

Design/methodology/approach

An automated design procedure has been developed to optimise sea-chest insert geometry to achieve desirable flow characteristics, while eliminating the necessity for support material in FDM manufacture – thereby significantly reducing build cost and time.

Findings

Numerical flow simulation confirms that the fluid-flow approximation is robust for optimising sea-chest insert geometry. Insert geometry can be manipulated to enable support-free additive manufacture; however, as the threshold angle for support-free manufacture increases, the set of feasible sea-chest aspect ratios decreases.

Research limitations/implications

The surface of revolution that defines the optimal insert geometry may result in features that are not compatible with additive manufacture constraints. An alternate geometry is proposed that may be more useful in practice without compromising anti-biofouling properties.

Practical implications

Marine sea-chest biofouling results in significant negative environmental and economic consequence. The method developed in this paper can reduce the negative impact of sea-chest biofouling.

Social implications

Marine sea-chest biofouling results in significant resource consumption and emissions. The method developed in this paper can reduce the negative impact of sea-chest biofouling.

Originality/value

The method presented in this paper provides an entirely original opportunity to utilise additive manufacture to mitigate the effects of marine biofouling.
Experimental investigations for development of Nylon6-Al-Al2O3 alternative FDM filament
Authors: Singh Boparai Kamaljit , Singh Rupinder , Singh Harwinder
Published: April 2016

Purpose

The purpose of this paper is to fabricate Nylon6-Al-Al2O3-based alternative fused deposition modeling process (FDM) feedstock filament in place of commercial acrylonitrile butadiene styrene (ABS) filament (having required rheological and mechanical properties) for rapid manufacturing (RM) and rapid tooling (RT) applications. The detailed steps for fabrication of alternative FDM feedstock filament (as per field application) with relatively low manufacturing cost and tailor-made properties have been highlighted.

Design/methodology/approach

The rheological and mechanical suitability of nylon6-Al-Al2O3 feedstock filament has been investigated experimentally. The approach is to predict and incorporate essential properties such as flow rate, flexibility, stiffness and mechanical strength at processing conditions and compared with commercial ABS material. The proportions of various constituents have been varied to modify and improve rheological behavior and mechanical properties of alternative FDM feedstock filament.

Findings

The alternative material of feed stock filament was successfully developed and loaded in commercial FDM setup without changing any hardware and software. The result of study suggests that the newly developed composite material filament has relatively poor mechanical properties but have highly thermal stability and wear resistant as compared to ABS filament and hence can be used for tailor-made applications.

Research limitations/implications

In this work, no additive was added for improving the bond formation of metal and polymeric materials. The newly developed filament was prepared on single screw extruder. For more uniform mixing of metal and polymeric materials, further studies may be conducted on twin screw extruder. Also, for the present research work, the testing of newly developed filament has been limited up to mechanical testing, which may be extended to chemical and thermal analysis to understand thermal stability and degradation mechanism of newly developed composite material.

Practical implications

The proportion of filler material (Al-Al2O3) in Nylon6 matrix was set as a constraint, which was adjusted based upon melt flow index of original equipment manufacturer developed material (ABS), and temperature conditions were available at FDM nozzle (so that hardware and software system of commercial FDM setup need not to be altered).

Originality/value

The present approach outlined selection, processing, fabrication and testing procedure for alternate feedstock filament, which fulfills the necessary requirements of FDM process and has been customized for RT and RM applications. This work highlights mechanical strength evaluation of feedstock filament (which is necessary before the loading of material in FDM system). The potential applications of this investigation include RM of functional parts, tailor-made grinding tools for dentists and RT of metal matrix composite having complex geometry.
Wear behavior of FDM parts fabricated by composite material feed stock filament
Authors: Singh Boparai Kamaljit , Singh Rupinder , Singh Harwinder
Published: April 2016

Purpose

In this study the friction and wear behavior of fused deposition modeling (FDM) parts fabricated with composite material and acrylonitrile butadiene
styrene (ABS) material feedstock filament were realized and compared under dry sliding conditions.

Design/methodology/approach

The tests were performed by applying the load of 5, 10, 15 and 20 N with sliding velocity of 0.63 m/s for the duration of 5 and 10 min at room temperature.

Findings

The results highlight various wear mechanisms such as adhesion, abrasion and fatigue during the investigation. It was observed that the wear volume, friction force, friction co-efficient and temperature were sensitive to the applied load and time duration. The composite material showed a remarkable improvement in wear properties as compared to the ABS material.

Research limitations/implications

The investigations reported in the present research work is based on comparative analysis (of composite material and ABS material feedstock filament). The results may be different in practical applications because of different operating conditions.

Practical implications

The parts fabricated with proposed composite material feedstock filament are highly wear resistant than basic ABS filament. This may lead to the development of better wear resistance components for numerous field applications.

Originality/value

The potential of this research work is to fabricate FDM parts with composite material feedstock filament to cater need of wear resistant industrial components.
Structural optimization of printed structures by self-organized relaxation
Authors: Zocca Andrea , Gomes Cynthia , Linow Ulf , Marx Heidi , Melcher Jörg , Colombo Paolo , Günster Jens
Published: April 2016

Purpose

This paper aims to present an additive manufacturing-based approach in which a new strategy for a thermally activated local melting and material flow, which results in densification of printed structures, is introduced.

Design/methodology/approach

For enabling this self-organized relaxation of printed objects by the viscous flow of material, two interconnected structures are printed simultaneously in one printing process, namely, Structure A actually representing the three dimensional object to be built and Structure B acting as a material reservoir for infiltrating Structure A. In an additional process step, subsequent to the printing job, an increase in the objects’ temperature results in the melting of the material reservoir B and infiltration of structure A.

Findings

A thermally activated local melting of the polymethylsilsesquioxane results in densification of the printed structures and the local formation of structures with minimum surface area.

Originality/value

The present work introduces an approach for the local relaxation of printed three-dimensional structures by the viscous flow of the printed material, without the loss of structural integrity of the structure itself. This approach is not restricted only to the materials used, but also offers a more general strategy for printing dense structures with a surface finish far beyond the volumetric resolution of the 3D printing process.
3D printing: a useful tool for the fabrication of artificial electromagnetic (EM) medium
Authors: Tian Xiaoyong , Yin Ming , Li Dichen
Published: April 2016

Purpose

Artificial electromagnetic (EM) medium and devices are designed with integrated micro- and macro-structures depending on the EM transmittance performance, which is difficult to fabricate by the conventional processes. Three-dimensional (3D) printing provides a new solution for the delicate artificial EM medium. This paper aims to first review the applications of 3D printing in the fabrication of EM medium briefly, mainly focusing on photonic crystals, metamaterials and gradient index (GRIN) devices. Then, a new design and fabrication strategy is proposed for the EM medium based on the 3D printing process, which was verified by the implementation of a 3D 90o Eaton lens based on GRIN metamaterials.

Design/methodology/approach

A new design and manufacturing strategy driven by the physical (EM transmittance) performance is proposed to illustrate the realization procedures of EM medium based device with controllable micro- and macro-structures. Stereolithography-based 3D printing process is used to obtain the designed EM device, an GRIN Eaton lens. The EM transmittance of the Eaton lens was validated experimentally and by simulation.

Findings

A 3D 90o Eaton lens was realized based on GRIN metamaterials structure according to the proposed design and manufacturing strategy, which had the broadband (12-18 GHz) and low loss characteristic. The feasibility of 3D printing for the artificial EM medium and GRIN devices has been verified for the further real applications in the industries.

Originality/value

The applications of 3D printing in artificial EM medium and devices were systematically reviewed. A new design strategy driven by physical performance for the EM device was proposed and validated by the firstly 3D printed 3D Eaton lens.
Forest structure along a 600 km transect of natural disturbances and seasonality gradients in central‐southern Amazonia
Authors: Schietti Juliana , Martins Demétrius , Emilio Thaise , Souza Priscila F. , Levis Carolina , Baccaro Fabricio B. , Pinto José Luiz Purri da Veiga , Moulatlet Gabriel M. , Stark Scott C. , Sarmento Kelly , de Araújo R. Nazaré O. , Costa Flávia R. C. , Schöngart Jochen , Quesada Carlos A. , Saleska Scott R. , Tomasella Javier , Magnusson William E.
Published: April 2016

A negative relationship between stand biomass and the density of stems is expected to develop during the self‐thinning process in resource‐limited forests; this leads to a large proportion of the total biomass occurring in large trees. Nevertheless, frequent disturbance regimes can reduce self‐thinning and the accumulation of large trees.

We investigated size–density relationships and the contribution of large trees (dbh ≥ 70 cm) to stand biomass in 55 1‐ha plots along a 600 km transect in central‐southern Amazonia. The effects of natural‐disturbance gradients (frequency of storms and soil characteristics) and seasonality on forest‐structure components (density of stems and mean individual mass) and stand biomass were examined.

Contrary to self‐thinning predictions, stand biomass increased in forests with higher stem densities. Large trees contained only an average of 5% of stand biomass, and half of the stand biomass was represented by small trees with diameters < 27 cm. These findings indicate that persistent or strong disturbance plays a critical role in forest structure and biomass in the central‐southern Amazon. Frequent storms were identified as an important source of disturbance in the region. Forests under higher frequency of storms had trees with lower individual mass and higher stem packing. More physically restrictive soils seem to magnify the effects of exogenous disturbances limiting individual tree size.

Forests in areas with longer dry seasons had lower stem densities; however, individual mass was higher in these areas. These structural components of biomass seem to counterbalance each other in generating total stand biomass. Seasonality affected forest structural components but not stand biomass.

Synthesis. Forests of central‐southern Amazonia are not resource limited and accumulate most part of their biomass in small‐ to mid‐sized trees. The effects of environmental gradients on specific structural components of stand biomass differ such that strong positive effects on one component can mitigate strong negative effects on other component. Future work on the determinants of stand biomass should investigate forest structure and the contributions of individual components to stand biomass.
A trait‐based approach to bacterial biofilms in soil
Authors: Lennon Jay T. , Lehmkuhl Brent K.
Published: April 2016

A trait‐based approach focuses on attributes of taxa that influence the structure and function of communities. Biofilm production is a common trait among microorganisms in a wide range of environmental, engineered, and host‐associated ecosystems. Here, we usedPseudomonas aeruginosato link biofilm production to moisture availability, a common stressor for microorganisms in soil. First, we demonstrate that biofilm production is a response trait that influences the desiccation phenotype by increasing survivorship, shifting the niche space, and reducing the minimum water potential needed to sustain a net‐positive growth rate (Ψ*). Although the allocation of resources to biofilms is thought to be costly, we found no evidence for a trade‐off between fitness and biofilm production along a soil moisture gradient. Second, we demonstrated that biofilm production is an effect trait. Specifically, biofilm production increased water retention in soils that were exposed to a series of drying and rewetting cycles. Although this form of niche construction should affect species interactions, we found no evidence that the benefits of biofilm production were extended to another co‐occurring soil bacterium. Together, our results support the view that biofilm production is an important trait that may contribute to the distribution, abundance, and functioning of microorganisms in soils.
Segregation of nod‐containing and nod‐deficient bradyrhizobia as endosymbionts of Arachis hypogaea and as endophytes of Oryza sativa in intercropped fields of Bengal Basin, India
Authors: Guha Sohini , Sarkar Monolina , Ganguly Pritha , Uddin Md Raihan , Mandal Sukhendu , DasGupta Maitrayee
Published: April 2016

Bradyrhizobial invasion in dalbergoid legumes like Arachis hypogaea and endophytic bacterial invasions in non‐legumes like Oryza sativa occur through epidermal cracks. Here, we show that there is no overlap between the bradyrhizobial consortia that endosymbiotically and endophytically colonise these plants. To minimise contrast due to phylogeographic isolation, strains were collected from Arachis/Oryza intercropped fields and a total of 17 bradyrhizobia from Arachis (WBAH) and 13 from Oryza (WBOS) were investigated. 16SrRNA and concatenated dnaK‐glnII‐recA phylogeny clustered the nodABC‐positive WBAH and nodABC‐deficient WBOS strains in two distinct clades. The in‐field segregation is reproducible under controlled conditions which limits the factors that influence their competitive exclusion. While WBAH renodulated Arachis successfully, WBOS nodulated in an inefficient manner. Thus, Arachis, like other Aeschynomene legumes support nod‐independent symbiosis that was ineffectual in natural fields. In Oryza, WBOS recolonised endophytically and promoted its growth. WBAH however caused severe chlorosis that was completely overcome when coinfected with WBOS. This explains the exclusive recovery of WBOS in Oryza in natural fields and suggests Nod‐factors to have a role in counterselection of WBAH. Finally, canonical soxY1 and thiosulphate oxidation could only be detected in WBOS indicating loss of metabolic traits in WBAH with adaptation of symbiotic lifestyle.
Type II NADH:quinone oxidoreductase family: phylogenetic distribution, structural diversity and evolutionary divergences
Authors: Marreiros Bruno C. , Sena Filipa V. , Sousa Filipe M. , Batista Ana P. , Pereira Manuela M.
Published: April 2016

Type II NADH:quinone oxidoreductases (NDH‐2s) are membrane proteins, crucial for the catabolic metabolism, because they contribute to the maintenance of the NADH/NAD+ balance. In several pathogenic bacteria and protists, NDH‐2s are the only enzymes performing respiratory NADH:quinone oxidoreductase activity. For this reason and for being considered absent in mammals, NDH‐2s were proposed as suitable targets for novel antimicrobial therapies. We selected all sequences of genes encoding NDH‐2s from fully sequenced genomes present in the KEGG database. These genes were present in 61% of the 1805 species belonging to Eukarya (83%), Bacteria (60%) and Archaea (32%). Notably sequences from mammal species including humans were retrieved in our selection as NDH‐2s. The data obtained and the already available information allowed systematizing several properties of NDH‐2s: (i) the existence of additional sequence motifs with putative regulatory functions, (ii) specificity towards NADH or NADPH and (iii) the type of quinone binding motif. We observed that NDH‐2 family distribution is not congruent with the taxonomic tree, suggesting different origins for the eukaryotic sequences and possible lateral gene transfer among prokaryotes. We note the absence of genes coding for NDH‐2 in anaerobic phyla and the presence of multiple copies in several genomes, specifically in cyanobacteria. These observations inspired us to propose a metabolic hypothesis for the appearance of NDH‐2s.
Urban Political Ecologies and Children's Geographies: Queering Urban Ecologies of Childhood
Authors: Shillington Laura J. , Murnaghan Ann Marie F.
Published: April 2016

This article focuses on the material and discursive constructions of nature and children in the city. While dominant representations and idealizations of nature and childhood depend on the binary logic of the nature/culture and rural/urban divide, there is also a simplification and romanticization of nature in children's geographies and a lack of children and their spaces in urban political ecology. We argue that children and nature in cities need to be removed from a binary model of being and attended to in more nuanced ways in urban political ecology and children's geographies. In this regard, we suggest that both nature and children in cities need to be queered. We need to ask how the production of urban spaces (re)creates particular romantic and idealized relations with natures that reify the binaries between nature/culture, and male/female through a heteronormative framework. The purpose of this article is to bring the critical nature–society theories of urban political ecology into conversation with work in children's geographies that explores the ‘nature' of childhood, and in doing so queer the relationship between children and nature. Drawing on research on queer ecologies, and queered childhoods, we aim to provide a framework to rethink and queer both nature and children in cities.
The Reliability of Pattern Classification in Bloodstain Pattern Analysis, Part 1: Bloodstain Patterns on Rigid Non‐absorbent Surfaces
Authors: Taylor Michael C. , Laber Terry L. , Kish Paul E. , Owens Glynn , Osborne Nikola K. P.
Published: April 2016

This study was designed to produce the first baseline measure of reliability in bloodstain pattern classification. A panel of experienced bloodstain pattern analysts examined over 400 spatter patterns on three rigid non‐absorbent surfaces. The patterns varied in spatter type and extent. A case summary accompanied each pattern that either contained neutral information, information to suggest the correct pattern (i.e., was positively biasing), or information to suggest an incorrect pattern (i.e., was negatively biasing). Across the variables under examination, 13% of classifications were erroneous. Generally speaking, where the pattern was more difficult to recognize (e.g., limited staining extent or a patterned substrate), analysts became more conservative in their judgment, opting to be inconclusive. Incorrect classifications increased as a function of the negatively biasing contextual information. The implications of the findings for practice are discussed.
HOW JUDGES THINK ABOUT RACIAL DISPARITIES: SITUATIONAL DECISION‐MAKING IN THE CRIMINAL JUSTICE SYSTEM*
Authors: CLAIR MATTHEW , WINTER ALIX S.
Published: April 2016

Researchers have theorized how judges’ decision‐making may result in the disproportionate presence of Blacks and Latinos in the criminal justice system. Yet, we have little evidence about how judges make sense of these disparities and what, if anything, they do to address them. By drawing on 59 interviews with state judges in a Northeastern state, we describe, and trace the implications of, judges’ understandings of racial disparities at arraignment, plea hearings, jury selection, and sentencing. Most judges in our sample attribute disparities, in part, to differential treatment by themselves and/or other criminal justice officials, whereas some judges attribute disparities only to the disparate impact of poverty and differences in offending rates. To address disparities, judges report employing two categories of strategies: noninterventionist and interventionist. Noninterventionist strategies concern only a judge's own differential treatment, whereas interventionist strategies concern other actors’ possible differential treatment, as well as the disparate impact of poverty and facially neutral laws. We reveal how the use of noninterventionist strategies by most judges unintentionally reproduces disparities. Through our examination of judges’ understandings of racial disparities throughout the court process, we enhance understandings of American racial inequality and theorize a situational approach to decision‐making in organizational contexts.
Enzymatic Synthesis of l‐Ascorbyl Fatty Acid Esters Under Ultrasonic Irradiation and Comparison of Their Antioxidant Activity and Stability
Authors: Jiang Chen , Lu Yuyun , Li Zhuo , Li Cunzhi , Yan Rian
Published: April 2016

A series of novel l‐ascorbyl fatty acid esters were synthesized by catalization of Novozym® 435 under ultrasonic irradiation and characterized by infrared spectroscopy, electrospray ionization mass spectra, and nuclear magnetic resonance. Their properties especially antioxidant activity and stability were investigated. The results showed that the reducing power, the scavenging activity of hydroxyl radical and 2,2‐diphenyl‐1‐picrylhydrazyl radical were decreased with the increase of the number of carbon atoms in fatty acid. The hydroxyl radical scavenging activity and reducing power of l‐ascorbyl saturated fatty acid esters were better than that of tert‐butylhydroquinone. The induction period in lipid oxidation of l‐ascorbyl saturated fatty acid esters and tert‐butylhydroquinone were longer than that of l‐ascorbyl unsaturated fatty acid esters and l‐ascorbic acid both in soybean oil and lard. Besides, the l‐ascorbyl fatty acid esters showed different stabilities in different conditions by comparing with l‐ascorbic acid, and the l‐ascorbyl saturated fatty acid esters were more stable than l‐ascorbyl unsaturated fatty acid esters in ethanol solution.
Recycling Irrigation Reservoir Stratification and Implications for Crop Health and Production
Authors: Zhang Haibo , Richardson Patricia A. , Belayneh Bruk E. , Ristvey Andrew , Lea‐Cox John , Copes Warren E. , Moorman Gary W. , Hong Chuanxue
Published: April 2016

Recycling irrigation reservoirs (RIRs) are an emerging aquatic ecosystem and water resource of global significance. This study investigated the vertical distribution of water temperature, dissolved oxygen (DO), and pH in eight RIRs at two nurseries each in Virginia and Maryland from 2011 to 2014. Monomictic thermal stratification was observed from April to October in all RIRs, despite their shallow depths (0.75‐3.89 m). The strongest stratification had a top‐bottom temperature difference of 21.53°C. The top‐bottom temperature difference was positively correlated with water column depth, air temperature, and daily light integral (p < 0.05). Wind speed did not impact the thermal stratification, likely due to their relatively small surface areas. Thermal stratification affected the vertical distribution of DO and pH. The top‐bottom differences in DO and pH were greater during stratification periods than nonstratification periods. Water pH in all RIRs was higher at the top than at the bottom with the greatest difference of 4.16 units. Discovery and characterization of thermal stratification in RIRs helps understand water quality dynamics in this novel ecosystem and promote safe and productive water reuse for irrigation. Specifically, water withdrawal depths should be adjusted according to variations in temperature, DO, and pH during the stratification and nonstratification periods to mitigate pathogen risk and improve water treatment efficacy and crop production.
Explaining adoption and use of payment instruments by US consumers
Authors: Koulayev Sergei , Rysman Marc , Schuh Scott , Stavins Joanna
Published: April 2016

Motivated by recent policy intervention into payments markets, we develop and estimate a structural model of adoption and use of payment instruments by U.S. consumers. Our structural model differentiates between the adoption and use of payment instruments. We evaluate substitution among payment instruments and welfare implications. Cash is the most significant substitute to debit cards in retail settings, whereas checks are the most significant in bill‐pay settings. Furthermore, low income consumers lose proportionally more than high income consumers when debit cards become more expensive, whereas the reverse is true when credit cards do.
Spinoffs and clustering
Authors: Golman Russell , Klepper Steven
Published: April 2016

Geographic clustering of innovative industries is associated with the entry and success of spinoff firms. We develop a model to explain the multiple empirical patterns regarding cluster growth and spinoff formation and performance, without relying on agglomeration externalities. Clustering naturally follows from spinoffs locating near their parents. In our model, firms grow and spinoffs form through the discovery of new submarkets based on innovation. Rapid and successful innovation creates more opportunities for spinoff entry and drives a region's growth. Our model provides baseline estimates of levels of agglomeration that can be attributed to this process of innovation and spinoff formation.
Economic Incentives in Health Care: The Case of Assigning Patients as “Not Ready for Care”
Authors: Gu Megan , Johar Meliyanni
Published: April 2016

We study perverse incentives in health care using the case of waiting lists for non‐emergency procedures. “Not ready for care” (NRFC) status removes patients indefinitely from the lists, and may be misused to improve performance reports. We test whether NRFC rate increases with rewards for good performance. The hospital database is also uniquely linked to a large survey, allowing us to investigate pro‐rich priority in medical treatment, as richer patients are more likely to be paying patients. Overall, we find support for misusage of NRFC status. This result holds regardless of urgency, including to patients with the highest urgency for treatment.
Three Dadanitic inscriptions from al‐ʿUḏayb (oasis of al‐ʿUlā) and the occurrence of the word s¹ṭ
Authors: Hidalgo‐Chacón Díez María del Carmen
Published: April 2016

The purpose of this paper is to study three Dadanitic inscriptions from the area of al‐ʿUḏayb, north‐west of the oasis of al‐ʿUlā. Two of these have been published previously, AH 111 and U 63, and one is as yet unpublished, U unp. 75. This hitherto unpublished inscription reveals new grammatical features not found before in any other Dadanitic text: the personal name {Ṭ}nfs¹s¹ and the preposition ʿn in the ablative sense. But the most common characteristic of these three texts in opposition to all other Dadanitic inscriptions is the occurrence of the word s¹ṭ. The formulaic sequences in which it occurs are quite striking: AH 111/3–4: s¹ṭ s¹ṭ ḏʿmn; U 63/2–3: w s¹ṭ ḏʿmn; and U unp. 75/1–2: w s¹ṭ‐h s¹ṭ ʿnʿḏrʾl. This word can be interpreted as a substantive meaning ‘officer’ on the one hand, and as a verb from the same root with the sense of ‘to command’ on the other, depending on its etymology and the grammatical context of the texts. It should be noted that its interpretation as ‘officer’ appears only in connection with the place name Ḏʿmn.
Platelet rich plasma and dentine effect on sheep dental pulp cells regeneration/revitalization ability (in vitro)
Authors: Altaii M , Kaidonis X , Koblar S , Cathro P , Richards L
Published: April 2016

Background

Platelet rich plasma (PRP) has been proposed as a scaffold for pulp regeneration/revitalization instead of a blood clot. The aim of the following in vitro study was to evaluate the effect of PRP scaffold on proliferation, migration and differentiation of cultured ovine (sheep) dental pulp cells (ODPC) in the presence of dentine .

Methods

PRP was prepared by centrifuging blood at 140 g for 12 min. ODPC were cultured on PRP or platelet poor plasma (PPP) scaffolds with and without dentine discs. Cell proliferation, migration and differentiation rates were assessed.

Results

ODPC cultured on PRP scaffold showed significantly greater proliferation rates, migration and mineralization compared with cells on PPP or without a scaffold. Dentine discs reduced the proliferation and mineralization potential of the cells.

Conclusions

A PRP scaffold has a positive effect on the proliferation, migration and differentiation of ODPC; however, dentine discs have an adverse effect on the activity of ODPC.
Differential effect of shade, water and soil type on emergence and early survival of three dominant species of the Atacama Desert
Authors: López Ramiro Pablo , Squeo Francisco A. , Gutiérrez Julio R.
Published: April 2016

Understanding the regeneration niche of species may allow us to gain insight into how communities are structured. In deserts, the regeneration niche is usually related to spaces beneath shrubs where shade cast by shrubs creates microenvironments that benefit seedlings and where even small amounts of rain may favour germination and establishment. Shade and water may also interact with different types of soils. However, species may have different requirements for germination and seedling survival. We could expect that shrub species with different drought tolerances exhibit different responses to the combination of these factors. We ask if responses of dominant species of the Atacama Desert to abiotic factors (shade, water and soil type) are related to their drought tolerance, a topic not exhaustively explored in shrubs growing in true deserts. We conducted two factorial experiments. The first one was designed to evaluate how shade (microhabitat) in combination with water may affect germination (emergence) and early survival. In the second experiment, we assessed the influence of shade in relation to soil type. Each species responded distinctively to the three variables under study, but in general, their emergence responses were more influenced by water (more water, greater emergence) than by microhabitat or soil type. Survival was influenced both by microhabitat and by water and was higher under shade and abundant water. Soil type affected only one of our species in terms of emergence. Species responses in general depended on their tolerance to stress. In one species, there was indication of a seed–seedling conflict. Our results show similar species responses to environmental constraints but also more or less unique responses that are related to their tolerance to drought and which may ultimately permit species coexistence. We found that shade may not be important for germination but may be crucial for survival in dry years.
Assessment of morbidity following regional nodal dissection in the axilla and groin for metastatic melanoma
Authors: Theodore Jane E. , Frankel Adam J. , Thomas Janine M. , Barbour Andrew P. , Bayley Gerard J. , Allan Christopher P. , Wagels Michael , Smithers B. Mark
Published: April 2016

Background

This study assessed and compared the morbidity of nodal dissection in the axilla and groin including sentinel lymph node biopsy (SLNB), completion lymph node dissection for a positive SLNB (CLND) and therapeutic lymph node dissection (TLND) with and without adjuvant radiotherapy (RT).

Methods

Patients who had nodal dissection in the axilla or groin for cutaneous melanoma over an 18‐year period (1995–2013) were prospectively documented on a database. The median follow‐up was nearly 3 years. Early complications and clinically relevant lymphoedema were retrospectively analysed to assess the incidence and differences between the region and type of nodal surgery.

Results

Included were 1521 patients following nodal dissection in the axilla (916 patients) and groin (605 patients). Less early complications occurred following SLNB in the axilla compared with the groin (5% versus 14%, P = 0.0001). Early complications were similar for CLND and TLND in the groin (49% versus 43%, P = 0.879) and axilla (28% versus 33%, P = 0.607). Moderate to severe lymphoedema rates were similar following axillary SLNB and CLND (6% versus 8%, P = 0.407). The lymphoedema rate for groin SLNB was lower than CLND (10% versus 20%, P = 0.063). No significant difference in lymphoedema rates followed CLND and TLND in each region. Following TLND, RT increased lymphoedema rates.

Conclusions

Morbidity may occur following SLNB with the groin having a higher rate of early complications and lymphoedema compared with the axilla. The morbidity following CLND and TLND were similar. Lymphoedema rates were increased following RT.
An international consensus report on a new algorithm for the management of infant diarrhoea
Authors: Lo Vecchio Andrea , Vandenplas Yvan , Benninga Marc , Broekaert Ilse , Falconer Jackie , Gottrand Frederic , Lifschitz Carlos , Lionetti Paolo , Orel Rok , Papadopoulou Alexandra , Ribes‐Koninckx Carmen , Salvatore Silvia , Shamir Raanan , Schäppi Michela , Staiano Annamaria , Szajewska Hania , Thapar Nikhil , Wilschanski Michael , Guarino Alfredo
Published: April 2016

Aim

Implementing international guidelines guarantees high standards of clinical care. A group of experts developed an algorithm to drive the management of common gastrointestinal symptoms in infancy by paediatricians and general practitioners.

Methods

The algorithm started from the evidence‐based recommendations of the European Society of Gastroenterology, Hepatology and Nutrition and the European Society of Pediatric Infectious Diseases and an updated review of the literature. We used the structured quantitative method of nominal group technique to reach a consensus.

Results

A practical algorithm for the management of infants with acute diarrhoea was designed based on the consensus reached for each statement. The management of an infant with acute diarrhoea should include a sequence of actions: (i) a semiquantitative estimate of infant dehydration through validated clinical scores, (ii) rehydration therapy and early refeeding with breast milk or regular formula and (iii) effective agents to reduce the severity and duration of the diarrhoea. Finally, in children with prolonged diarrhoea, the search for aetiology should include persistent infections or reinfections, cows' milk protein allergy and coeliac diseases. Lactose should always be withdrawn.

Conclusion

This algorithm provides an evidence‐based sequence of interventions to optimise the management of infants with acute diarrhoea.
Critical reappraisal of primary osseous composite sarcoma (malignant mesenchymoma) – analysis of four cases and literature review
Authors: Chow Louis T. C.
Published: April 2016

In accordance with recent terminology, it is proposed that malignant mesenchymoma should be renamed ‘composite sarcoma’ and defined as ‘a sarcoma composed of two or more cellular types each of which is sufficiently differentiated to permit clear recognition of its histogenetic type microscopically, immunohistochemically or ultrastructurally; excluding fibrosarcomatous and high‐grade pleomorphic undifferentiated sarcomatous component, dedifferentiated sarcoma and the combination of osteosarcoma and chondrosarcoma which is regarded as a single histogenetic type’. Four cases of primary osseous composite sarcoma (POCS) were identified among 928 primary bone sarcomas. Their age ranged from 10 to 87 years, peak incidence in the second decade with equal sex distribution. Most presented with pain, commonest in the knee, affecting the metaphysis, appearing radiologically as expansile infiltrative osteolytic lesions with cortical erosion, periosteal reaction, variable extent of osteoblastic areas and soft tissue extension. All contained variable amounts of conventional high‐grade osteosarcoma with or without chondrosarcoma component; the other constituents were liposarcoma, rhabdomyosarcoma and leiomyosarcoma. In all cases, Ki67 proliferative index was over 35%, there was no CDK4 and MDM2 amplification. The absence of low‐grade component supported the de novo origin of POCS rather than derivation from divergent dedifferentiation. The two older patients with hitherto undescribed osteoleiomyosarcoma died 2 and 10 months after operation, whereas the two younger with osteorhabdomyosarcoma and osteoliposarcoma enjoyed disease‐free survival at 16 and 6 years after chemotherapy despite the latter showing lung metastasis at presentation. Identification of the different lines of differentiation together with their approximate amounts and histological grades is therefore mandatory for POCS as multi‐agent chemotherapy catered for each sarcoma component might offer hope for long‐term disease‐free survival.
Syphilis epidemiology in 1994–2013, molecular epidemiological strain typing and determination of macrolide resistance in Treponema pallidum in 2013–2014 in Tuva Republic, Russia
Authors: Khairullin Rafil , Vorobyev Denis , Obukhov Andrey , Kuular Ural‐Herel , Kubanova Anna , Kubanov Alexey , Unemo Magnus
Published: April 2016

The incidence of syphilis in the Tuva Republic (geographical centre of Asia), Russia has been exceedingly high historically. No detailed examinations and no molecular investigations of Treponema pallidum strains transmitted in the Tuva Republic, or in general, in Russia, were published internationally. We examined the syphilis epidemiology in 1994–2013, and the molecular epidemiology and macrolide resistance in T. pallidum strains in 2013–2014 in the Tuva Republic. Among 95 mainly primary or secondary syphilis patients, the arp, tpr, tp0548 and 23S rRNA genes in 85 polA gene‐positive genital ulcer specimens were characterized. The syphilis incidence in Tuva Republic peaked in 1998 (1562), however declined to 177 in 2013. Among the 70 (82%) completely genotyped specimens, six molecular strain types were found. Strain type 14d/f accounted for 91%, but also 14c/f, 14d/g, 14b/f, 14i/f, 9d/f, and 4d/f were identified. Two (2.4%) specimens contained the 23S rRNA A2058G macrolide resistance mutation. This is the first internationally published typing study regarding T. pallidum in Russia, performed in the Tuva Republic with the highest syphilis incidence in Russia. The two molecular strain types 4d/f and 9d/f have previously been described only in Eastern and Northern China and for the first time, macrolide‐resistant syphilis was described in Russia.
Attitudes and knowledge of urethral catheters: a targeted educational intervention
Authors: Cohen Andrew , Nottingham Charles , Packiam Vignesh , Jaskowiak Nora , Gundeti Mohan
Published: April 2016

Objective

To assess the training of medical students and their confidence in urethral catheter placement, given growing evidence of unnecessary urology consults and iatrogenic injury.

Subjects and Methods

A third‐year medical school class was queried about their attitudes and knowledge of catheter placement before and after the Clinical Biennium. The Clinical Biennium introduces hands‐on skills prior to clinical clerkships. Urethral catheterisation is one of the skill stations that students rotate through, and urology residents provide a didactic session and supervised simulation. Confidence was self‐rated regarding catheter technique, knowledge, troubleshooting, and comfort with placement in the same and opposite gender. Factual questions were posed about proper insertion and malfunctioning catheters.

Results

In all, 92 students participated in the initial survey, 41% female and 59% male, and 87% of the students had never placed a catheter. Students desired high confidence in catheter skills (4.4/5). There were no significant differences in responses for those with a desire to pursue urology vs other specialties, or procedural fields compared with non‐procedural fields. Prior independent learning was reported by 38% of students and was a predictor for increased confidence across all domains (P < 0.05). In all, 16.7% of students initially identified proper male urethral insertion distance, which improved to 95.6% after the session. Student interest in urology modestly increased after the educational session (P = 0.028). At 3–6 months follow‐up, students had performed a median (interquartile range) of 4 (2–7) urethral catheter placements, and 74.2% of students rated training useful or extremely useful. Indeed, 54.8% desired more instruction. Knowledge assessment indicated that 93% of students retained comprehension of proper male urethral insertion distance. Clinical Foley training rarely contradicted instruction from the Clinical Biennium (6.5%). At all time‐points, medical student knowledge for troubleshooting catheters was low.

Conclusions

Medical students strive for high confidence in urethral catheter placement. Prior targeted education improves confidence and knowledge. Together with clinical experience, these effects are durable up to 6 months.
No One's Monopoly: Chilean Liberalism in the Post‐Independent Period, 1823–1830
Authors: OSSA JUAN LUIS
Published: April 2016

This article begins by arguing that military officer Ramón Freire and his successor, Francisco Antonio Pinto, advocated for a form of liberalism that, although supportive of individual rights, depended upon a centralised system of government. Then it claims that there was a consensus in Chile in the 1820s that the best political regime for the country was republicanism, and that differences between factions did not concentrate so much on ideological issues as on specific aspects of Chilean politics. These included the articles of the Constitution of 1828 that jeopardised the economic supremacy of landlords and debates regarding the limits of the freedom of the press. The third section of the article shows that ‘conservatives’ pushed for a freer Press Law than the ‘liberals’ at the end of the 1820s, thus proving that different liberal traditions emerged in Chile in the aftermath of independence. The conclusion of the article emphasises that liberalism in Chile was no one's monopoly.
Metaflammasome components in the human brain: a role in dementia with Alzheimer's pathology?
Authors: Taga Mariko , Minett Thais , Classey John , Matthews Fiona E. , Brayne Carol , Ince Paul G. , Nicoll James AR , Hugon Jacques , Boche Delphine ,   MRC CFAS
Published: April 2016

Epidemiological and genetic studies have identified metabolic disorders and inflammation as risk factors for Alzheimer's disease (AD). Evidence in obesity and type‐2 diabetes suggests a role for a metabolic inflammasome (“metaflammasome”) in mediating chronic inflammation in peripheral organs implicating IKKβ (inhibitor of nuclear factor kappa‐B kinase subunit beta), IRS1 (insulin receptor substrate 1), JNK (c‐jun N‐terminal kinase), and PKR (double‐stranded RNA protein kinase). We hypothesized that these proteins are expressed in the brain in response to metabolic risk factors in AD. Neocortex from 299 participants from the MRC Cognitive Function and Ageing Studies was analysed by immunohistochemistry for the expression of the phosphorylated (active) form of IKKβ [pSer176/180], IRS1 [pS312], JNK [pThr183/Tyr185] and PKR [pT451]. The data were analyzed to investigate whether the proteins were expressed together and in relation with metabolic disorders, dementia, Alzheimer's pathology and APOE genotype. We observed a change from a positive to a negative association between the proteins and hypertension according to the dementia status. Type‐2 diabetes was negatively related with the proteins among participants without dementia; whereas participants with dementia and AD pathology showed a positive association with JNK. A significant association between IKKβ and JNK in participants with dementia and AD pathology was observed, but not in those without dementia. Otherwise, weak to moderate associations were observed among the protein loads. The presence of dementia was significantly associated with JNK and negatively associated with IKKβ and IRS1. Cognitive scores showed a significant positive relationship with IKKβ and a negative with IRS1, JNK and PKR. The proteins were significantly associated with pathology in Alzheimer's participants with the relationship being inverse or not significant in participants without dementia. Expression of the proteins was not related to APOE genotype. These findings highlight a role for these proteins in AD pathophysiology but not necessarily as a complex.
Social anxiety and autism spectrum traits among adult FMR1 premutation carriers
Authors: López‐Mourelo O. , Mur E. , Madrigal I. , Alvarez‐Mora M.I. , Gómez‐Ansón B. , Pagonabarraga J. , Rodriguez‐Revenga L. , Milà M.
Published: April 2016

Behavioral symptoms and traits have been proposed as early markers in neurodegenerative diseases. The aim of this study was to evaluate social anxiety and autism in FMR1 premutation carriers using the Social Phobia Inventory (SPIN) and the Autism‐Spectrum Quotient (AQ) questionnaires. Fifty‐nine premutation carriers were compared with 50 controls. The SPIN test showed statistically significant differences between female but not male carriers. The AQ questionnaire found statistically significant differences between premutation carriers and controls in the total AQ as well as in the social skills and attention switching subdomains. A gender effect was only observed for the social skills subdomain. Spearman's correlation analysis revealed a moderately positive correlation with the total AQ scores as well as the social skills and communication subdomains. Our results show that fragile X‐associated tremor/ataxia syndrome (FXTAS) patients have higher AQ scores. Moreover, this is the first study to find statistically significant differences between FXTAS and no‐FXTAS premutation carriers in the communication and the imagination subdomains, suggesting that FXTAS patients present a broader autistic phenotype than premutation carriers without FXTAS. Based on our results, a wide range of behavioral/psychiatric traits should be included within the broader phenotypic presentation of individuals with the FMR1 premutation.