bluuebunny/crossref_metadata_2025 huggingface dataset:
The use of impedance threshold devices in spontaneously breathing, hypotensive trauma patients
Authors: James RH , Henning DCW , Smith JE
Published: September 2014

Impedance threshold devices are a novel therapeutic option to increase blood pressure in the spontaneously breathing, hypotensive, trauma patient. They have multiple potential mechanisms of action. The most important is their ability to induce a more negative intrathoracic pressure during inspiration. They achieve this by the presence of a series of valves. These valves only open once the patient has generated a more negative intrathoracic pressure than is normally required for inspiration to occur. This negative intrathoracic pressure is thought to increase venous return and therefore cardiac output and subsequently blood pressure. This narrative review examines the evidence pertaining to the use of these devices in spontaneously breathing, hypotensive, trauma patients. While the literature supports the ability of these devices to increase systolic blood pressure in both animal and human models of hypotension, and more recently in patients with true pathological hypotension, potential flaws are discussed, and several key questions that have not been addressed by studies to date are highlighted. Notwithstanding these problems, impedance threshold devices may have a role in hypotensive trauma patients, particularly during the pre-hospital phase of care when available resources limit treatment options. Further work is required to prove both their clinical effectiveness and safety.
Procedural sedation and analgesia in the emergency department
Authors: Jacques Keith G , Dewar Alistair , Gray Alasdair , Kerslake Dean , Leal Alexis , Open Michele
Published: September 2014

Procedural sedation and analgesia (PSA) is a core part of modern emergency department (ED) care allowing the rapid provision of important procedures. The safe delivery of a PSA service requires an appropriately staffed and equipped environment backed up by an ongoing system of training, audit and review. Topics covered in this review include: the evidence relating to the agents used; patient care before, during and after the procedure; the outcomes of ED PSA; and, the special considerations relating to PSA in children.
Organizational learning in the implementation and adoption of national electronic health records: Case studies of two hospitals participating in the National Programme for Information Technology in England
Authors: Takian Amirhossein , Sheikh Aziz , Barber Nicholas
Published: September 2014

Objective:

To explore the role of organizational learning in enabling implementation and supporting adoption of electronic health record systems into two English hospitals.

Methods and setting:

In the course of conducting our prospective and sociotechnical evaluation of the implementation and adoption of electronic health record into 12 “early adopter” hospitals across England, we identified two hospitals implementing virtually identical versions of the same “off-the-shelf” software (Millennium) within a comparable timeframe. We undertook a longitudinal qualitative case study–based analysis of these two hospitals (referred to hereafter as Alpha and Omega) and their implementation experiences. Data included the following: 63 in-depth interviews with various groups of internal and external stakeholders; 41-h on-site observation; and content analysis of 218 documents of various types. Analysis was both inductive and deductive, the latter being informed by the “sociotechnical changing” theoretical perspective.

Results:

Although Alpha and Omega shared a number of contextual similarities, our evaluation revealed fundamental differences in visions of electronic health record and the implementation strategy between the hospitals, which resulted in distinct local consequences of electronic health record implementation and impacted adoption. Both hospitals did not, during our evaluation, see the hoped-for benefits to the organization as a result of the introduction of electronic health record, such as speeding-up tasks. Nonetheless, the Millennium software worked out to be easier to use at Omega. Interorganizational learning was at the heart of this difference.

Conclusion:

Despite the turbulent overall national “roll out” of electronic health record systems into the English hospitals, considerable opportunities for organizational learning were offered by sequential delivery of the electronic health record software into “early adopter” hospitals. We argue that understanding the process of organizational learning and its enabling factors has the potential to support efforts at implementing national electronic health record implementation endeavors.
Dynamic model and behavior of viscoelastic beam based on the absolute nodal coordinate formulation
Authors: Zhao Chunzhang , Yu Haidong , Lin Zhongqin , Zhao Yong
Published: September 2014

Viscoelastic material is widely used in mechanisms and its properties have a great influence on the dynamic behaviors of structures. In this study, a modified viscoelastic constitutive model is developed by introducing the nonlinear strain–displacement relation of materials to the classical Kelvin–Voigt model. The new model can be implemented into the finite element absolute nodal coordinate formulation directly, which can be applied to investigate the large rotation and the large deformation problem. The mass matrix and the viscoelastic stiffness matrix of a two-dimensional viscoelastic beam with shear deformation are derived with the absolute nodal coordinate formulation. The dynamic model of the beam is presented based on Newton equations. The dynamic equations are transformed from a set of differential algebraic equations to a set of first-order ordinary differential equations, which are calculated by using the fourth-order explicit Runge–Kutta method. A free falling flexible pendulum is employed to study the correlation between the dynamic behaviors of structures and the mechanical behaviors of materials. The results indicate that the modified constitutive model is able to describe the nonlinear deformation behavior of the structure, which undergoes large rotation and large deformation. The flexible deformation of the beam is related to the elastic modulus, the density and the viscosity coefficient of the material. The viscous behavior of material reduces the elastic deformation of the structure during its movement, which is beneficial to the kinematic accuracy of the multibody system.
The insertion and deletion (I28005D) polymorphism of the angiotensin I converting enzyme gene is a risk factor for osteoarthritis in an Asian Indian population
Authors: Poornima Subhadra , Subramanyam Krishna , Khan Imran Ali , Hasan Qurratulain
Published: September 2014

Introduction:

Angiotensin I converting enzyme (ACE) insertion and deletion (I/D) polymorphism has been implicated in the pathogenesis of osteoarthritis (OA). In recent years, numerous genetic factors have been identified and implicated in OA. In this Asian Indian population-based study, we aimed to evaluate the relationship between ACE (I28005D) gene polymorphism and primary OA. We performed a case-control association study to identify and explore the correlation between clinically, radiologically diagnosed individuals with primary knee OA and the ACE I/D polymorphism.

Methods:

Genomic DNA was isolated from 200 samples, including 100 OA cases and 100 healthy volunteers. DNA was amplified by polymerase chain reaction (PCR) using I and D allele-specific primers. PCR products were assessed via UV visualization of products electrophoresed on 2% agarose gels.

Results:

The groups differed significantly in genotype distributions ( p < 0.05). The primary knee OA group showed a considerably higher incidence of the DD genotype and the D allele compared to the control group (OR = 2.14, 95% CI: 1.10–4.15, p = 0.02 and OR = 2.08, 95% CI: 1.39–3.10, p = 0.0003).

Conclusion:

The ACE gene polymorphism I28005D was found to be associated with primary knee OA in Asian Indian populations. This is the first study in India to report that the ACE gene polymorphism is a risk factor for early onset primary knee OA.
Spatial planning in cross-border regions: A systems-theoretical perspective
Authors: Jacobs Joren
Published: September 2014

Most scholarship in spatial planning presupposes an established institutional setting, where a specific legal framework is in place, one is accustomed to certain procedures and routines, and planning has a certain (national) history. In cross-border regions, however, this becomes problematic as different institutional settings clash. Combining systems and organizational theory, this article constructs a theoretical perspective on planning, explicitly conceptualizing differences, that is, boundaries, in institutional settings. This sheds new light on the prospects and realities of spatial planning across national borders. National borders double the complexity of spatial planning, and organizations working in cross-border spatial planning need to take this into account by acknowledging their own and others’ organizational boundaries as well.
A conversation between Noel Timms and a US social work practitioner, nascent sociologist
Authors: Bell Steph
Published: September 2014

In this section essay, I engage in a conversation with Timms’ (1967) A Sociological Approach to Social Problems, 50 years after its initial publication, from the perspective of an experienced social work practitioner and nascent sociologist. I use, and build on, Timms’ work in three areas, considering: the usefulness of a sociological approach to social problems for social work, the integration of critical-reflexivity in social science scholarship, and how a sociological approach to social problems can inform analysis of social work practice experience, particularly in terms of being an agent of social change or social control.
Stainless steel/nitinol braid coronary stents: Braiding structure stability and cut section treatment evaluation
Authors: Ueng Kwo-Chang , Wen Shih-Peng , Lou Ching-Wen , Lin Jia-Horng
Published: September 2014

This study proposes braid coronary stents with a form of reticular tube by using a braiding technique. Stainless steel fibers with a diameter of 0.08 mm and nitinol fibers are braided with various tooth numbers on the take-up gear and a specified tooth number on the braid gear with a hollow braiding technique in order to have different braiding angles. The resulting braids are then immersed in a polyvinyl alcohol solution in a custom-made mold to form braid coronary stents. A stereomicroscope is used to observe the cut section, a scanning electron microscope is used to examine the treatment for sharp points of the fibers, and Image Pro Plus software is used to analyze braiding angles and metal cover rate. The experiment results show that braiding angle influences the braiding structure; in addition, the larger the braiding angle, the less easily the fiber interaction points move. The immersion in polyvinyl alcohol solution can effectively bond the fiber interaction points, resulting in a better braiding structure. Metal cover rates are all below 20.9%. This study successfully creates novel braid coronary stents.
Troubling Dissemination
Authors: Knight Linda , Cumming Tamara
Published: September 2014

Salons became popular in Europe in 17th century as sites of philosophic and literary conversation. A group of female academics interested in Deleuzian theories experimented with the salon to challenge presentation and dissemination norms that hierarchize and centralize the human. For Deleuze and Guattari, assemblages are shifting and decentering, so how might assemblages of chairs, tables, bodies, lights, and space help to trouble thinking about the methodological conventions around academic disseminations? The authors discuss the salon as a critical-cultural site: Cumming presents Deleuze and play-dough, an exploration of how the playful dissemination format of the salon prompted a re-reading of a methodological vignette from earlier research. Knight, an arts-based researcher, uses video art as a creative methodology to examine conceptualizations of rhizomes and assemblages at the salon as a dissemination site. The authors conclude that the salon, as a critical, cultural site disrupts hierarchized ways of approaching and presenting research.
Trace element status and zinc homeostasis differ in breast and formula-fed piglets
Authors: Ronis Martin JJ , Miousse Isabelle R , Mason Andrew Z , Sharma Neha , Blackburn Michael L , Badger Thomas M
Published: September 2014

Differences in trace element composition and bioavailability between breast milk and infant formulas may affect metal homeostasis in neonates. However, there is a paucity of controlled studies in this area. Here, piglets were fed soy infant formula (soy), cow’s milk formula (milk), or were allowed to suckle from the sow from PND2 to PND21. Serum iron concentrations were higher in formula-fed compared to breastfed piglets ( P < 0.05). Serum zinc values were higher in milk compared to breastfed or soy groups ( P < 0.05). Zinc transporter Zip4 mRNA was elevated in small intestine of the soy compared to breastfed group ( P < 0.05). Transporter Znt1 mRNA was greater in small intestine of both formula-fed groups and in liver of the milk compared to the breastfed group ( P < 0.05). Metallothionein Mt1 mRNA expression was higher in small intestine and liver of milk compared to breastfed and soy groups ( P < 0.05). In liver, metallothionein protein levels and protein bound zinc were also highly elevated in the milk compared to other groups ( P < 0.05). mRNA encoding the hepatic zinc-regulated gene Gclc was higher in the milk than soy group ( P < 0.05). ChIP assay revealed increased binding of the zinc-regulated transcription factor MTF1 to the promoters of hepatic Mt3 and Gclc genes in the milk compared to the soy group. These data provide evidence that trace element status differs in breastfed, milk-fed, and soy-fed piglets and that despite similar levels of dietary supplementation, allows strong causal inference that significant differences in serum zinc after cow’s milk formula compared to soy formula consumption result in compensatory changes in expression of zinc transporters, binding proteins, and zinc-regulated genes.
Plagiarism in the academic context: A study of Iranian EFL learners
Authors: Ahmadi Alireza
Published: September 2014

The present study was an attempt to shed light on the status of plagiarism in the Iranian academic context. It tried to survey the EFL learners’ perceptions of and reasons for different types of plagiarism. To this end, 132 EFL learners from different Iranian universities took part in the study. The data were collected through using a questionnaire specifically designed to gather information on plagiarism. The results indicated that plagiarism is quite common in the Iranian EFL context as different types of plagiarism are employed by the students. Many students were found not to have a negative attitude toward plagiarism. The results also indicated that gender, marital status and occupational status did not have a significant effect on plagiarism, whereas academic level, field of study, and age played a significant role in this regard.
Contribution to system failure occurrence prediction and to system remaining useful life estimation based on oil field data
Authors: Vališ David , Žák Libor , Pokora Ondřej
Published: September 2014

At present, numerous approaches are devoted to monitoring a system state. Their intention is to determine the current state of a system and predict reliability parameters for the future. This article addresses one of the several possible approaches that allows us to determine a system technical state on the basis of diagnostic data. These diagnostic data are from the area of tribiodagnostics, namely, engine oil. The article examines iron and lead particles that are selected deliberately with respect to their origin in kinematic parts of the system and their degree of correlation with operation measures. The particles occur in oil during both operating time and calendar time development. To model their occurrence during operation time, we have used, in the first part of the article, a mathematical regression method to set parameters. In the second part, we have applied a diffusion model based on a Wiener process. The results confirm that we are able to estimate the residual technical life of a system. Moreover, the results enable us to schedule properly the intervals of preventive maintenance (oil change) and to plan a mission/operation. This results in optimising life cycle costs. It is assumed that the potential of the diagnostic data will be extracted by other approaches and methods. In the subsequent work, it will be useful to determine specific interval values of optimised preventive maintenance.
Diverticulitis in the Young
Authors: Kijsirichareanchai Kunut , Mankongpaisarnrung Charoen , Sutamtewagul Grerk , Nugent Kenneth , Rakvit Ariwan
Published: September 2014

Background: Colonic diverticulitis is relatively uncommon in young patients, especially those younger than 40 years. We compared demographic data, clinical presentation, management, and clinical course of diverticulitis in patients ≤40 years old compared with patients >40 years old. Methods: This study included all patients who presented to the emergency department with a diagnosis of diverticulitis between October 1, 2009 and September 30, 2010. Patients were divided into 2 groups: group 1 (≤40 years old) and group 2 (>40 years old). Demographic characteristics, clinical presentation and management, and short-term outcomes were compared. Results: Ninety-four patients were included in the study (37 patients in group 1 and 57 patients in group 2). A higher percentage of obese and Hispanic men was found in group 1 ( P > .05). The rate of discharge from the emergency department was significantly higher in group 1 (56.8% in group 1 vs 7.0% in group 2, P < .01). Group 2 patients had a shorter median length of stay than group 1 patients (3.1 vs 5.7 days, P = .16). There were no differences in vital signs, laboratory data (including complete blood count and basic metabolic panel), and in-hospital mortality rates between the 2 groups. Conclusions: This study demonstrates that young Hispanic men develop diverticulitis and that this diagnosis needs to be considered when they present to emergency rooms with abdominal symptoms. A longitudinal study is needed to determine the long-term outcomes in these patients and to investigate the pathogenesis.
Racial Crime Stereotypes and Offender Juvenility
Authors: Pickett Justin T. , Welch Kelly , Chiricos Ted , Gertz Marc
Published: September 2014

Recent theoretical advancements of the racial threat model of punitiveness suggest that because youthful offending has driven crime trends in recent decades, and because racially exclusive conceptions of childhood have historically structured public opinion on juvenile justice, Black criminal stereotypes may be especially consequential for attitudes toward juvenile punishments. Building on this work, the current study uses national survey data to examine whether the strength of the relationship between Black criminal stereotypes and support for punitive policies varies according to whether punishments are targeted toward juvenile delinquents or criminals in general. We find that Black criminal stereotypes are positively associated with punitive attitudes and that the magnitude of this effect is statistically identical in the cases of youth-specific and nonyouth-specific sanctions. Thus, the results suggest that racialized support for punitive crime policies is not influenced by the juvenility of the offender.
TiO2-coated nanostructures for dye photo-degradation in water
Authors: Scuderi Viviana , Impellizzeri Giuliana , Romano Lucia , Scuderi Mario , Nicotra Giuseppe , Bergum Kristin , Irrera Alessia , Svensson Bengt G , Privitera Vittorio
Published: September 2014

The photocatalytic efficiency of a thin-film TiO2-coated nanostructured template is studied by dye degradation in water. The nanostructured template was synthesized by metal-assisted wet etching of Si and used as substrate for the deposition of a thin film of TiO2 (10 nm thick) by atomic layer deposition. A complete structural characterization was made by scanning and transmission electron microscopies. The significant photocatalytic performance was evaluated by the degradation of two dyes in water: methylene blue and methyl orange. The relevance of the reported results is discussed, opening the route toward the application of the synthesized nanostructured TiO2 for water purification.
Oxidative stress mediated cytotoxicity of biologically synthesized silver nanoparticles in human lung epithelial adenocarcinoma cell line
Authors: Han Jae Woong , Gurunathan Sangiliyandi , Jeong Jae-Kyo , Choi Yun-Jung , Kwon Deug-Nam , Park Jin-Ki , Kim Jin-Hoi
Published: September 2014

The goal of the present study was to investigate the toxicity of biologically prepared small size of silver nanoparticles in human lung epithelial adenocarcinoma cells A549. Herein, we describe a facile method for the synthesis of silver nanoparticles by treating the supernatant from a culture of Escherichia coli with silver nitrate. The formation of silver nanoparticles was characterized using various analytical techniques. The results from UV-visible (UV-vis) spectroscopy and X-ray diffraction analysis show a characteristic strong resonance centered at 420 nm and a single crystalline nature, respectively. Fourier transform infrared spectroscopy confirmed the possible bio-molecules responsible for the reduction of silver from silver nitrate into nanoparticles. The particle size analyzer and transmission electron microscopy results suggest that silver nanoparticles are spherical in shape with an average diameter of 15 nm. The results derived from in vitro studies showed a concentration-dependent decrease in cell viability when A549 cells were exposed to silver nanoparticles. This decrease in cell viability corresponded to increased leakage of lactate dehydrogenase (LDH), increased intracellular reactive oxygen species generation (ROS), and decreased mitochondrial transmembrane potential (MTP). Furthermore, uptake and intracellular localization of silver nanoparticles were observed and were accompanied by accumulation of autophagosomes and autolysosomes in A549 cells. The results indicate that silver nanoparticles play a significant role in apoptosis. Interestingly, biologically synthesized silver nanoparticles showed more potent cytotoxicity at the concentrations tested compared to that shown by chemically synthesized silver nanoparticles. Therefore, our results demonstrated that human lung epithelial A549 cells could provide a valuable model to assess the cytotoxicity of silver nanoparticles.
Coincidence point theorems in quasi-metric spaces without assuming the mixed monotone property and consequences in G-metric spaces
Authors: Roldán-López-de-Hierro Antonio-Francisco , Karapınar Erdal , de la Sen Manuel
Published: September 2014

In this paper, we present some coincidence point theorems in the setting of quasi-metric spaces that can be applied to operators which not necessarily have the mixed monotone property. As a consequence, we particularize our results to the field of metric spaces, partially ordered metric spaces and G-metric spaces, obtaining some very recent results. Finally, we show how to use our main theorems to obtain coupled, tripled, quadrupled and multidimensional coincidence point results.
A fast multipole method for stellar dynamics
Authors: Dehnen Walter
Published: September 2014

The approximate computation of all gravitational forces between N interacting particles via the fast multipole method (FMM) can be made as accurate as direct summation, but requires less than
O
(
N
)
operations. FMM groups particles into spatially bounded cells and uses cell-cell interactions to approximate the force at any position within the sink cell by a Taylor expansion obtained from the multipole expansion of the source cell. By employing a novel estimate for the errors incurred in this process, I minimise the computational effort required for a given accuracy and obtain a well-behaved distribution of force errors. For relative force errors of ∼10−7, the computational costs exhibit an empirical scaling of
∝

N
0.87

. My implementation (running on a 16 core node) out-performs a GPU-based direct summation with comparable force errors for
N
≳

10

5

.
Investigating the Effectiveness of an Educational Card Game for Learning How Human Immunology Is Regulated
Authors: Su TzuFen , Cheng Meng-Tzu , Lin Shu-Hua
Published: September 2014

This study was conducted in an attempt to investigate the effectiveness of an educational card game we developed for learning human immunology. Two semesters of evaluation were included to examine the impact of the game on students’ understanding and perceptions of the game-based instruction. Ninety-nine senior high school students (11th graders) were recruited for the first evaluation, and the second-semester group consisted of 72 students (also 11th graders). The results obtained indicate that students did learn from the educational card game. Moreover, students who learned from playing the game significantly outperformed their counterparts in terms of their understanding of the processes and connections among different lines of immunological defense (first semester: t = 2.92, p < 0.01; second semester: t = 3.45, p < 0.01) according to the qualitative analysis of an open-ended question. They generally had positive perceptions toward the game-based instruction and its learning efficiency, and they felt the game-based instruction was much more interesting than traditional didactic lectures (first semester: t = 2.79, p < 0.01; second semester: t = 2.41, p < 0.05). This finding is evidence that the educational card game has potential to facilitate students’ learning of how the immune system works. The implications and suggestions for future work are further discussed.
Beyond Punnett Squares: Student Word Association and Explanations of Phenotypic Variation through an Integrative Quantitative Genetics Unit Investigating Anthocyanin Inheritance and Expression inBrassica rapaFast Plants
Authors: Batzli Janet M. , Smith Amber R. , Williams Paul H. , McGee Seth A. , Dósa Katalin , Pfammatter Jesse
Published: September 2014

Genetics instruction in introductory biology is often confined to Mendelian genetics and avoids the complexities of variation in quantitative traits. Given the driving question “What determines variation in phenotype (Pv)? (Pv=Genotypic variation Gv + environmental variation Ev),” we developed a 4-wk unit for an inquiry-based laboratory course focused on the inheritance and expression of a quantitative trait in varying environments. We utilized Brassica rapa Fast Plants as a model organism to study variation in the phenotype anthocyanin pigment intensity. As an initial curriculum assessment, we used free word association to examine students’ cognitive structures before and after the unit and explanations in students’ final research posters with particular focus on variation (Pv = Gv + Ev). Comparison of pre- and postunit word frequency revealed a shift in words and a pattern of co-occurring concepts indicative of change in cognitive structure, with particular focus on “variation” as a proposed threshold concept and primary goal for students’ explanations. Given review of 53 posters, we found ∼50% of students capable of intermediate to high-level explanations combining both Gv and Ev influence on expression of anthocyanin intensity (Pv). While far from “plug and play,” this conceptually rich, inquiry-based unit holds promise for effective integration of quantitative and Mendelian genetics.
Identifying Key Features of Effective Active Learning: The Effects of Writing and Peer Discussion
Authors: Linton Debra L. , Pangle Wiline M. , Wyatt Kevin H. , Powell Karli N. , Sherwood Rachel E.
Published: September 2014

We investigated some of the key features of effective active learning by comparing the outcomes of three different methods of implementing active-learning exercises in a majors introductory biology course. Students completed activities in one of three treatments: discussion, writing, and discussion + writing. Treatments were rotated weekly between three sections taught by three different instructors in a full factorial design. The data set was analyzed by generalized linear mixed-effect models with three independent variables: student aptitude, treatment, and instructor, and three dependent (assessment) variables: change in score on pre- and postactivity clicker questions, and coding scores on in-class writing and exam essays. All independent variables had significant effects on student performance for at least one of the dependent variables. Students with higher aptitude scored higher on all assessments. Student scores were higher on exam essay questions when the activity was implemented with a writing component compared with peer discussion only. There was a significant effect of instructor, with instructors showing different degrees of effectiveness with active-learning techniques. We suggest that individual writing should be implemented as part of active learning whenever possible and that instructors may need training and practice to become effective with active learning.
Connections between Student Explanations and Arguments from Evidence about Plant Growth
Authors: Dauer Jenny M. , Doherty Jennifer H. , Freed Allison L. , Anderson Charles W.
Published: September 2014

We investigate how students connect explanations and arguments from evidence about plant growth and metabolism—two key practices described by the Next Generation Science Standards. This study reports analyses of interviews with 22 middle and high school students postinstruction, focusing on how their sense-making strategies led them to interpret—or misinterpret—scientific explanations and arguments from evidence. The principles of conservation of matter and energy can provide a framework for making sense of phenomena, but our results show that some students reasoned about plant growth as an action enabled by water, air, sunlight, and soil rather than a process of matter and energy transformation. These students reinterpreted the hypotheses and results of standard investigations of plant growth, such as van Helmont's experiment, to match their own understanding of how plants grow. Only the more advanced students consistently interpreted mass changes in plants or soil as evidence of movement of matter. We also observed that a higher degree of scaffolding during some of the interview questions allowed mid-level students to improve their responses. We describe our progress and challenges developing teaching materials with scaffolding to improve students’ understanding of plant growth and metabolism.
Peritubular Myoid Cells Participate in Male Mouse Spermatogonial Stem Cell Maintenance
Authors: Chen Liang-Yu , Brown Paula R. , Willis William B. , Eddy Edward M.
Published: September 2014

Peritubular myoid (PM) cells surround the seminiferous tubule and together with Sertoli cells form the cellular boundary of the spermatogonial stem cell (SSC) niche. However, it remains unclear what role PM cells have in determining the microenvironment in the niche required for maintenance of the ability of SSCs to undergo self-renewal and differentiation into spermatogonia. Mice with a targeted disruption of the androgen receptor gene (Ar) in PM cells experienced a progressive loss of spermatogonia, suggesting that PM cells require testosterone (T) action to produce factors influencing SSC maintenance in the niche. Other studies showed that glial cell line-derived neurotrophic factor (GDNF) is required for SSC self-renewal and differentiation of SSCs in vitro and in vivo. This led us to hypothesize that T-regulated GDNF expression by PM cells contributes to the maintenance of SSCs. This hypothesis was tested using an adult mouse PM cell primary culture system and germ cell transplantation. We found that T induced GDNF expression at the mRNA and protein levels in PM cells. Furthermore, when thymus cell antigen 1-positive spermatogonia isolated from neonatal mice were cocultured with PM cells with or without T and transplanted to the testes of germ cell-depleted mice, the number and length of transplant-derived colonies was increased considerably by in vitro T treatment. These results support the novel hypothesis that T-dependent regulation of GDNF expression in PM cells has a significant influence on the microenvironment of the niche and SSC maintenance.
The Israeli-Palestinian Negotiations: The US Framework for Peace Must Be Enforced
Authors: Ben-Meir Alon
Published: September 2014

There are many who doubt that the current Israeli-Palestinian negotiations will lead to a solution, in spite of US secretary of state John Kerry’s efforts and the presumed commitment to peace of Israeli prime minister Benjamin Netanyahu and Palestinian president Mahmoud Abbas. What has characterized the intractability of the conflict in the past, including the future of Jerusalem, the Palestinian refugees, Israel’s national security concerns, and, in particular, the psychological dimension behind these conflicting issues, still remain in play. That intractability has been further aggravated by a faulty framework for the 2014 negotiations, the absence of leadership, the continued public recrimination of each side toward the other, mutual distrust, and the lack of commitment to reach an agreement that of necessity requires mutually painful concessions. This essay proposes a number of mechanisms and corrective measures that could appreciably enhance the prospect of reaching a peace agreement. Undergirding these proposals is the need for the United States to put its foot down and warn both the Israelis and Palestinians that, unless they negotiate in earnest based on Kerry’s proposed framework, there will be serious consequences resulting from a reassessment of its bilateral relations with both parties.
The Greek Failing State and Its “Smart Power” Prospects: A Theoretical Approach
Authors: Litsas Spyridon N.
Published: September 2014

Since 2010 Greece has been between a rock and a hard place. In particular, since May 2010 the so-called troika (European Commission, International Monetary Fund, and European Central Bank) has provided financial support to Greece through an economic adjustment program while the Greek state is forced to undergo holistic austerity. This essay supports the view that Greece is a failing state: it suffers a systemic ailment and declines rapidly but has not yet reached its bottom. It can reemerge as a healthy state, but only if a “grand strategy” is applied. This essay scrutinizes the main reasons behind Greece’s dire condition and puts forward a “smart state” theory to explore ways to remedy the situation. The essay also suggests how Greece can exit from its labyrinth and emerge as a smart state.
Blessed Is He Who Considers the Human Rights Paradigm: Maltese Aid between Charity and Human Rights and between Catholicism and Secularism
Authors: Calleja-Ragonesi Isabelle , Khakee Anna , Pisani Maria
Published: September 2014

Malta became a donor country with European Union membership in 2004. Maltese organizations (most prominently—but not solely—those linked to the Catholic Church) had, however, been active in development overseas long before that date. This essay offers the first systematic, empirically grounded account of Maltese governmental and nongovernmental aid, based on official and unofficial statistical information on official development assistance levels and distribution; a database compiled by the authors covering nongovernmental Maltese development organizations; and an analysis of a sample of government- and nongovernment-funded projects. The essay analyzes the empirical material based on the dichotomy of charity-based versus humanrights-based development and examines how these two development paradigms overlap with—and differ from—the Catholic/secular divide within the Maltese aid landscape.
A dynamic analysis of muscle fusion in the chick embryo
Authors: Sieiro-Mosti Daniel , De La Celle Marie , Pelé Manuel , Marcelle Christophe
Published: September 2014

Skeletal muscle development, growth and regeneration depend upon the ability of muscle cells to fuse into multinucleated fibers. Surprisingly little is known about the cellular events that underlie fusion during amniote development. Here, we have developed novel molecular tools to characterize muscle cell fusion during chick embryo development. We show that all cell populations arising from somites fuse, but each with unique characteristics. Fusion in the trunk is slow and independent of fiber length. By contrast, the addition of nuclei in limb muscles is three times more rapid than in trunk and is tightly associated with fiber growth. A complex interaction takes place in the trunk, where primary myotome cells from the medial somite border rarely fuse to one another, but readily do so with anterior and posterior border cells. Conversely, resident muscle progenitors actively fuse with one another, but poorly with the primary myotome. In summary, this study unveils an unexpected variety of fusion behaviors in distinct embryonic domains that is likely to reflect a tight molecular control of muscle fusion in vertebrates.
The PAR complex controls the spatiotemporal dynamics of F-actin and the MTOC in directionally migrating leukocytes
Authors: Crespo Carolina Lage , Vernieri Claudio , Keller Philipp J. , Garrè Massimiliano , Bender Jeffrey R. , Wittbrodt Joachim , Pardi Ruggero
Published: September 2014

Inflammatory cells acquire a polarized phenotype to migrate toward sites of infection or injury. A conserved polarity complex comprising PAR-3, PAR-6, and atypical protein kinase C (aPKC) relays extracellular polarizing cues to control cytoskeletal and signaling networks affecting morphological and functional polarization. Yet, there is no evidence that myeloid cells use PAR signaling to migrate vectorially in 3D environments in vivo. Using genetically-encoded bioprobes and high-resolution live imaging we revealed the existence of F-actin oscillations in the trailing edge and constant MTOC repositioning to direct leukocyte migration in wounded medaka fish larvae. Genetic manipulation in live myeloid cells demonstrated that the catalytic activity of aPKC and the regulated interaction with PAR-3/PAR-6 are required for consistent F-actin oscillations, MTOC perinuclear mobility, aPKC repositioning and wound-directed migration upstream of Rho-kinase/ROCK/ROK activation. We propose that the PAR complex coordinately controls cytoskeletal changes affecting both traction force generation and directionality of leukocyte migration to sites of injury.
Shed syndecan-2 inhibits angiogenesis
Authors: De Rossi Giulia , Evans Alun R. , Kay Emma , Woodfin Abigail , McKay Tristan R. , Nourshargh Sussan , Whiteford James R.
Published: September 2014

Angiogenesis is essential for the development of a normal vasculature, tissue repair and reproduction, and also has roles in the progression of diseases such as cancer and rheumatoid arthritis. The heparan sulphate proteoglycan syndecan-2 is expressed on mesenchymal cells in the vasculature and, like the other members of its family, can be shed from the cell surface resulting in the release of its extracellular core protein. The purpose of this study was to establish whether shed syndecan-2 affects angiogenesis. We demonstrate that shed syndecan-2 regulates angiogenesis by inhibiting endothelial cell migration in human and rodent models and, as a result, reduces tumour growth. Furthermore, our findings show that these effects are mediated by the protein tyrosine phosphatase receptor CD148 (also known as PTPRJ) and this interaction corresponds with a decrease in active β1 integrin. Collectively, these data demonstrate an unexplored pathway for the regulation of new blood vessel formation and identify syndecan-2 as a therapeutic target in pathologies characterised by angiogenesis.
Integrins regulate epithelial cell differentiation by modulating Notch activity
Authors: Gómez-Lamarca M. Jesús , Cobreros-Reguera Laura , Ibáñez-Jiménez Beatriz , Palacios Isabel M. , Martín-Bermudo María D.
Published: September 2014

Coordinating exit from the cell cycle with differentiation is critical for proper development and tissue homeostasis. Failure to do so can lead to aberrant organogenesis and tumorigenesis. However, little is known about the developmental signals that regulate the cell cycle exit-to-differentiation switch. Signals downstream of two key developmental pathways, Notch and Salvador-Warts-Hippo (SWH), and of myosin activity regulate this switch during the development of the follicle cell epithelium of the Drosophila ovary. Here, we have identified a fourth player, the integrin signaling pathway. We find that elimination of integrin function blocks mitosis-to-endocycle switch and differentiation in posterior follicle cells (PFCs), via regulation of the CDK inhibitor dacapo. In addition, we show that integrin mutant PFCs show defective Notch signalling and endocytosis. Furthermore, integrins act in PFCs by modulating the activity of the Notch pathway, as reducing the amount of Hairless, the major antagonist of Notch, or misexpressing Notch intracellular domain rescues the cell cycle and differentiation defects. Altogether, our findings reveal a direct involvement of integrin signalling on the spatial and temporal regulation of epithelial cell differentiation during development.
Kidney Exchange with Long Chains: An Efficient Pricing Algorithm for Clearing Barter Exchanges with Branch-and-Price
Authors: Glorie Kristiaan M. , van de Klundert J. Joris , Wagelmans Albert P. M.
Published: September 2014

Barter exchange markets are markets in which agents seek to directly trade their goods with each other. Exchanges occur in cycles or in chains in which each agent gives a good to the next agent. Kidney exchange is an important type of barter exchange market that allows incompatible patient–donor pairs to exchange kidneys so the involved patients can receive a transplant. The clearing problem is to find an allocation of donors to patients that is optimal with respect to multiple criteria. To achieve the best possible score on all criteria, long cycles and chains are often needed, particularly when there are many hard-to-match patients. In this paper we show why this may pose difficulties for existing approaches to the optimization of kidney exchanges. We then present a generic iterative branch-and-price algorithm that can deal effectively with multiple criteria, and we show how the pricing problem may be solved in polynomial time for a general class of criteria. Our algorithm is effective even for large, realistic patient–donor pools. Our approach and its effects are demonstrated by using simulations with kidney exchange data from the Netherlands and the United States.
Vascularised or non-vascularised autologous fibular grafting for the reconstruction of a diaphyseal bone defect after resection of a musculoskeletal tumour
Authors: Schuh R. , Panotopoulos J. , Puchner S. E. , Willegger M. , M. Hobusch G. , Windhager R. , Funovics P. T.
Published: September 2014

Resection of a primary sarcoma of the diaphysis of a long bone creates a large defect. The biological options for reconstruction include the use of a vascularised and non-vascularised fibular autograft.

The purpose of the present study was to compare these methods of reconstruction.

Between 1985 and 2007, 53 patients (26 male and 27 female) underwent biological reconstruction of a diaphyseal defect after resection of a primary sarcoma. Their mean age was 20.7 years (3.6 to 62.4). Of these, 26 (49 %) had a vascularised and 27 (51 %) a non-vascularised fibular autograft. Either method could have been used for any patient in the study. The mean follow-up was 52 months (12 to 259). Oncological, surgical and functional outcome were evaluated. Kaplan–Meier analysis was performed for graft survival with major complication as the end point.

At final follow-up, eight patients had died of disease. Primary union was achieved in 40 patients (75%); 22 (42%) with a vascularised fibular autograft and 18 (34%) a non-vascularised (p = 0.167). A total of 32 patients (60%) required revision surgery. Kaplan–Meier analysis revealed a mean survival without complication of 36 months (0.06 to 107.3, sd 9) for the vascularised group and 88 months (0.33 to 163.9, sd 16) for the non-vascularised group (p = 0.035).

Both groups seem to be reliable biological methods of reconstructing a diaphyseal bone defect. Vascularised autografts require more revisions mainly due to problems with wound healing in distal sites of tumour, such as the foot.

Cite this article: Bone Joint J 2014;96-B:1258–63.
Modified Pauwels’ intertrochanteric osteotomy in the management of nonunion of a femoral neck fracture following failed osteosynthesis
Authors: Magu N. K. , Singla R. , Rohilla R. , Gogna P. , Mukhopadhyay R. , Singh A.
Published: September 2014

We report the outcome of 39 patients who underwent a modified Pauwels’ intertrochanteric osteotomy for nonunion of a femoral neck fracture following failed osteosynthesis. There were 31 men and eight women with a mean age of 47.2 years (34 to 59). By Pauwels’ classification, there were 11 Type II fractures and 28 Type III fractures. The mean follow-up was 7.9 years (2 to 19). In the 11 patients whose initial treatment had been osteotomy, union was achieved in nine (81.8%). In 28 patients whose initial treatment had been with a lag screw or a dynamic hip screw, union was achieved in 27 (96.4%). Limb lengths were equalised in 14 of 16 patients (87.5%) with pre-operative shortening. The mean neck-shaft angle improved significantly from 100.5° (80° to 120°) to 131.6° (120° to 155°) (p = 0.004). The mean modified Harris hip score was 85.6 points (70 to 97) and the mean modified Merle d’Aubigné score was 14.3 (11 to 18). Good to excellent functional outcomes were achieved in 32 patients (88.8%). A modified Pauwels’ intertrochanteric osteotomy is a reliable method of treating ununited fractures of the femoral neck following failed osteosynthesis: coxa vara and shortening can also simultaneously be addressed.

Cite this article: Bone Joint J 2014;96-B:1198–1201.
Evaluation of the magnitude and location of Cam deformity using three dimensional CT analysis
Authors: Khan O. , Witt J.
Published: September 2014

The cam-type deformity in femoroacetabular impingement is a 3D deformity. Single measurements using radiographs, CT or MRI may not provide a true estimate of the magnitude of the deformity. We performed an analysis of the size and location of measurements of the alpha angle (α°) using a CT technique which could be applied to the 3D reconstructions of the hip. Analysis was undertaken in 42 patients (57 hips; 24 men and 18 women; mean age 38 years (16 to 58)) who had symptoms of femoroacetabular impingement related to a cam-type abnormality. An α° of > 50° was considered a significant indicator of cam-type impingement. Measurements of the α° were made at different points around the femoral head/neck junction at intervals of 30°: starting at the nine o’clock (posterior), ten, eleven and twelve o’clock (superior), one, two and ending at three o’clock (anterior) position.

The mean maximum increased α° was 64.6° (50.8° to 86°). The two o’clock position was the most common point to find an increased α° (53 hips; 93%), followed by one o’clock (48 hips; 84%). The largest α° for each hip was found most frequently at the two o’clock position (46%), followed by the one o’clock position (39%). Generally, raised α angles extend over three segments of the clock face.

Single measurements of the α°, whether pre- or post-operative, should be viewed with caution as they may not be representative of the true size of the deformity and not define whether adequate correction has been achieved following surgery.

Cite this article: Bone Joint J 2014;96-B:1167–71.