bluuebunny/crossref_metadata_2025 huggingface dataset:
Novel Mobile App Allows for Fast and Validated Intraoperative Assessment of Otolaryngology Residents
Authors: Kozin Elliott D. , Bohnen Jordan D. , George Brian C. , Justicz Natalie , Colaianni C. Alessandra , Duarte Maria , Gray Stacey T.
Published: January 2017

Evaluation of resident operative skills is challenging in the fast‐paced operating room environment and limited by lack of validated assessment metrics. We describe a smartphone‐based app that enables rapid assessment of operative skills. Accreditation Council for Graduate Medical Education (ACGME) otolaryngology taxonomy surgical procedures (n = 593) were uploaded to the software platform. The app was piloted over 1 month. Outcomes included (1) completion of evaluation, (2) time spent completing the evaluation, and (3) quantification of case complexity, operative autonomy, and performance. During the study, 12 of 12 procedures, corresponding to 3 paired evaluated by the resident/attending dyad. Mean ± SD time of evaluation completion was 98.0 ± 24.2 and 123.0 ± 14.0 seconds for the resident and attending, respectively. Mean time between resident and attending evaluation completion was 27.9 ± 26.8 seconds. Resident and attending scores for case complexity, operative autonomy, and performance were strongly correlated (P <. 0001). Rapid evaluation of resident intraoperative performance is feasible using smartphone‐based technology.
Sonographic Reference Values for Fetal Transverse Cerebellar Diameter in the Second and Third Trimesters in a Nigerian Population
Authors: Eze Charles Ugwoke , Onwuzu Queendaline Ebere , Nwadike Innocent Uchechukwu
Published: January 2017

This study aimed to establish reference values of fetal transverse cerebellar diameter (TCD) in a Nigerian population. A cross-sectional convenience study was carried out between June 2013 and May 2014 in Enugu, Nigeria. The sonographic examinations were performed on 697 pregnant women with gestational ages between 14 and 40 weeks. The TCD measurements were obtained from the proximal outer margin to the distal outer margin of cerebellum. The women’s last menstrual period, femur length, biparietal diameter, head circumference, and abdominal circumference were also recorded. The mean (standard deviation) TCD increased from 13.6 (2.2) mm to 27.3 (2.6) mm and 28.9 (2.0) mm to 42.9 (2.0) mm in the second and third trimesters, respectively. The relationship of TCD with gestational age obtained from last menstrual period, femur length, biparietal diameter, head circumference, and abdominal circumference was determined. The TCD had a strong correlation with gestational age ( r = .93; P < .05). Reference values for TCD were established for those patients who attended this clinic. This is a likely data set to use for future research that could focus on similar practices and in other regions of the country for possible generation of a nationwide nomogram.
Diagnosis of Urethral Stricture on Dynamic Voiding Transvaginal Sonourethrography
Authors: Bhatt Shuchi , Goel Mohit , Gupta Arun , Tandon Anupama , Roy Satarupa
Published: January 2017

Urethral stricture in a woman is a difficult diagnosis to establish due to its rarity and clinical resemblance to bladder outlet obstruction. Imaging is used to differentiate between the various bladder, urethral, and extrinsic causes of obstruction with the standard voiding cystourethrographic examination but with little success in female patients. The following case presents complete urethral stricture in a woman, which was detected with transvaginal sonography. Transvaginal sonography is not a common modality used to assess female urethral anatomy. The urinary bladder is comfortably distended, unlike in transvaginal sonography for gynecologic indications. Urethral evaluations can be carried out while the patient strains in an attempt to void the urinary bladder. As the normal proximal urethra distends with the antegrade flow of urine during straining, the urethral caliber and wall can be evaluated to assess the level, cause, and severity of obstruction. Sonography provides the unique ability to capture a dynamic assessment of the urethra for a reasonable length of time, without the use of ionizing radiation.
The Sonographer’s Role in HCAHPS and Value-Based Purchasing
Authors: Barymon Deanna
Published: January 2017

Health care reimbursements are changing from a medical care-based scale to a pay-for-performance system. The Value-Based Purchasing Program uses clinical quality indicators along with the Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) survey as part of an incentive program for hospitals to gain reimbursements based on the patient care experience. Although clinical quality indicators are often outside of a sonographer’s scope of practice, several of the HCAHPS items are a routine part of a sonographer’s daily duties, such as communication and responsiveness to the patient and cleanliness of the facility. Providing education concerning HCAHPS and Value-Based Purchasing to clinical sonographers, as well as student sonographers, will improve patient interactions and assist hospitals in gaining reimbursements.
Sonographic Evaluation of Fractures in Children
Authors: Wang Crystal C. , Linden Kadine L. , Otero Hansel J.
Published: January 2017

Fractures and suspected fractures are common causes for pediatric visits to the emergency department. Initial evaluation routinely includes imaging in the form of radiographs. Additional imaging modalities including sonography and magnetic resonance are used as problem-solving tools. Sonography has been reported to perform well when compared with radiography in multiple anatomies from the skull and nasal bones to the upper and lower extremities. In addition, sonography presents unique advantages including lack of ionizing radiation, cross-sectional coverage, evaluation of soft tissue injury, and the possibility of imaging the contralateral side. This article reviews the applications, advantages, disadvantages, technique, and performance of sonography in the imaging of fractures in children.
After Eden: Envy and the defences against anxiety paradigm
Authors: Stein Mark
Published: January 2017

Envy has the potential for substantial destructiveness in social systems. Despite its fundamental place in the Kleinian psychoanalytic study of individuals, for several decades, envy has been virtually excluded from psychoanalytic studies of social systems. This paper focuses on this omission, arguing that the Kleinian school established a paradigm focusing on 'social systems as a defence against anxiety'. The implicit delimiting of this paradigm has allowed no room for envy: envy is quite distinct from anxiety; and it is not defensive, involving unwarranted attacks instead. In recent years, envy has emerged as the existing paradigm's anomaly. It is argued here that a new paradigm which has conceptual space for the notion of 'social systems as an envious attack' is required. Group, organizational and societal examples are offered to exemplify the dangerous and malignant potential of envy in such social systems.
Crowds, context and identity: Dynamic categorization processes in the 'poll tax riot'
Authors: Stott Clifford , Drury John
Published: January 2017

Reicher has recently developed the social identity model of crowd behaviour based on self-categorization theory (SCT). This model begins to tackle the thorny theoretical problems posed by the dynamic nature of crowd action (Reicher, 1996b). The present paper describes an ethnographic study of a crowd event in which there were changes in the inter-group relationships over time. It is suggested that the laboratory evidence in support of SCT is complemented by ethnographic research of this type. By exploring situations in which definitions of context and/or categories are not purposefully manipulated, we can demonstrate the explanatory power of a dynamic and interactive approach to social categorization.
Measures of five aspects of affective well-being at work
Authors: Daniels Kevin
Published: January 2017

Validation evidence is provided for scales that measure five aspects of affective well-being in relation to the work context: anxiety-comfort, depression-pleasure, bored-enthusiastic, tiredness-vigour and angry-placid. Confirmatory factor analysis is used to test four alternative structures for the items in the scales in two samples (n = 871, n = 1915). Analyses in both samples support one structure. The final scales have acceptable internal reliability. The unique explanatory power of each scale is suggested by partial correlations with theoretically related variables. Confirmatory factor analysis indicates that the five factor solution has a better fit with the data than other first order solutions with fewer factors. Second order factor analysis shows that two superordinate factors, corresponding to negative and positive affect, can account for the relationships amongst the five first order factors.
Trust and inter-organizational networking
Authors: Newell Susan , Swan Jacky
Published: January 2017

Inter-organizational and multi-functional networking are increasingly portrayed as new and potentially more effective forms of organization, especially where innovation is important. This is as true for academic work undertaken within universities as it is for business organizations; multi-disciplinary and inter-institutional collaboration being specified as highly desirable by the major research funding bodies. Integrating mechanisms are essential if such networks are to be effective in co-ordinating the work of a diverse range of partners. Importantly, they are required for the development of trust. Thus, the literature stresses that trust between the parties is central to the effective operation of such networks. This paper explores the evolution of trust within a particular inter-university, multi-disciplinary research team, and develops a model depicting the development and interrelation of different types of trust within this network. The difficulties this research network experienced in developing trust raise a more general question about the effectiveness of interdisciplinary research.
Intra- and inter-justice relationships: Assessing the direction
Authors: Robbins Tina , Summers Timothy P. , Miller Janice L.
Published: January 2017

This field study used structural equation modeling to investigate the relationships among: (1) distributive and procedural justice; (2) justice components and organizational commitment; and (3) justice components and behaviors/behavioral intentions. The results suggest that, over time, procedural justice judgments are likely to influence perceptions of distributive justice, but not vice versa. In addition, the results suggest that both distributive justice and procedural justice have reciprocal relationships with commitment and turnover intentions, although in some cases they are contingent on lagged effects. Relationships between procedural justice and behaviors (i.e. compliance, performance) were unidirectional, significant only in the justice-to-behavior direction.
How do people become empowered? A case study of union activists
Authors: Kaminski Michelle , Kaufman Jeffrey S. , Graubarth Robin , Robins Thomas G.
Published: January 2017

Many organizations are interested in empowerment, believing that empowered workers will be more effective in reaching their goals. What does it mean to be empowered, and how do people achieve this state? Using qualitative data, we applied the developmental model proposed by Kieffer to a sample of 14 worker-trainers. We found that Kieffer's model worked well with this sample, with some modification. One is that workers did not have to feel personally threatened in order to become activists, as did Kieffer's original sample. A second is that not all workers followed the four stages in the order proposed. Our data also suggested that worker-trainers who had reached a more advanced stage of empowerment were more successful at their task. Finally, based on the model, we also highlight ways to design interventions to help people further develop their stage of empowerment.
Coping with change: The contribution of postdichotomous ontologies
Authors: Beech Nicholas , Cairns George
Published: January 2017

This article seeks to conceptualize interactions surrounding organizational change. Four ideal types of reality(ies) are presented here using the metaphor of language. Actors' representations of experience are presented in order to illustrate these concepts. We argue that types 1 and 2, which are epitomized by dichotomous thought, are unlikely to provide adequate managerial insight in coping with complex change, whereas types 3 and 4, which are typified by 'postdichotomous' thought, hold greater possibilities as frameworks for coping with such social situations. The concept of 'coping', as opposed to 'managing', as a way of 'acting thinkingly' in and around organizational change is explored.
Power and emotion in organizational learning
Authors: Vince Russ
Published: January 2017

This article explores the difference between learning in an organization and organizational learning. I construct a conceptual framework for understanding organizational learning at an organizational level of analysis. This framework is based on the proposition that organizational learning is visible in the organizational dynamics created from the interaction between politics (power relations) and emotion within an organization. Using a combination of psychodynamic theory and reflections on the politics of organizing I develop the idea that organizations are learning when the 'establishment' that is being created through the very process of organizing can be identified and critically reflected upon. I use a case example of a change initiative within Hyder PLC, a multinational company, to identify organizational dynamics that limit organizational learning. In the final part of the article, I discuss the conclusions that emerged from the case example and the implications of these conclusions for the theory and practice of organizational learning.
Managerial behavior in a multiplex role system
Authors: Valcour P. Monique
Published: January 2017

This article uses ethnographic data gathered from a parent cooperative nursery school to examine the strategies managers use to resolve role conflict in a multiplex role system, that is, a setting in which the relationship between managers and the people they supervise is based on more than one set of roles. In the organization under study, teachers functioned as both managers of, and service providers to, the parent volunteers they were charged with supervising. Parents' volunteer worker role was subject to conflict with and interruption by the expectations of their organizational client role, which constrained teachers' ability to direct parents' work in the classroom. Managerial effectiveness required responding to the demands and expectations of both sets of roles through a process of adaptive self-regulation. Teachers used several discrepancy detection strategies to gather information on parent volunteers' relative role salience, role transition readiness, and volunteer skills. Based on the information obtained, they devised discrepancy reduction strategies to focus parents' attention on the desired role for task performance and to reduce discrepancies between parents' expectations for managerial behavior and their own actions. The most effective teachers were able to develop personal relationships with parent volunteers, elicit knowledge about parents' role expectations and capabilities, and respond to the expectations of parents' multiple roles on an individualized basis.
The politics of imagined stability: A psychodynamic understanding of change at Hyder plc
Authors: Vince Russ
Published: January 2017

The aim of this article is to show how psychodynamic theory and its application can inform the management of change in organizations. The article outlines a psychodynamic framework for the management of change, emphasizing the interrelation between individual and collective emotional experience and power relations. The phrase a politics of imagined stability is used to describe the role that social and strategic politics play in the perpetuation of emotions and fantasies that have an impact on organizing. The framework involves understanding how the organization is imagined, experienced and maintained through the influence of social and strategic politics, as well as the resulting emotional and political relations within which attempts at change have to be managed. The conceptual framework is illustrated and developed through a case example from Hyder plc, formerly the largest private company in Wales, UK. The discussion and conclusion outline the articles contribution to knowledge concerning psychodynamic thinking and the management of change.
Leadership and negative capability
Authors: Simpson Peter F , French Robert , Harvey Charles E
Published: January 2017

Our aim in this article is to explore and explain the concept of 'negative capability', in the context of the current resurgence of interest in organizational leadership. We suggest that negative capability can create an intermediate space that enables one to continue to think in difficult situations. Where positive capability supports 'decisive action', negative capability supports 'reflective inaction', that is, the ability to resist dispersing into defensive routines when leading at the limits of one's knowledge, resources and trust. The development of negative capability is discussed but it is suggested that its status is problematic in the context of a societal and organizational culture dominated by control and performativity. The practice of negative capability is illustrated throughout the article, using a case study of the leadership of an international joint venture.
When theories become tools: Toward a framework for pragmatic validity
Authors: Worren Nicolay Am , Moore Karl , Elliott Richard
Published: January 2017

In this article we discuss the characteristics of knowledge that lead to practical utility. We first review previous efforts at identifying the characteristics of useful knowledge. These contributions are grouped into three perspectives according to which representational mode they imply: propositional, narrative, or visual. We develop a framework for pragmatic validity that encompasses knowledge represented in all three modes. However, we also note an over-reliance on the propositional mode in academia, which contrasts with a preference for narrative and visual knowledge among practitioners. Explicit and propositional knowledge are key criteria for achieving scientific validity, but more ambiguous knowledge serves important functions in organizational life and may thus possess pragmatic validity. We highlight the role of conceptual models expressed in a visual format, a representational mode that has received little attention in the literature. We end with suggestions for further research that may extend the notion of pragmatic validity and lead to a more refined framework for the development of useful knowledge.
Thinking about doing: On learning from experience and the flight from thinking
Authors: Levine David P
Published: January 2017

This article explores the relationship between learning, thinking, and doing. A case study of a course in group dynamics is presented, and the desire of students in that course to learn about groups simply by being in a group is considered. The article argues that the desire to learn simply by having an experience expresses a conservative impulse. If all we have is an experience, all we can learn is the inevitability of repeating it. This makes learning from experience the enemy of creativity as its purpose is not to discover what might be, but to assure the reproduction of what is. Learning from experience in this sense means failing to learn from experience. Failure to learn from experience is linked to fear of thinking. When the group is imagined to be a refuge from thinking, appeal to learning by doing expresses the need to replace learning with belonging.
Writing (Across) Europe: On Writing Spaces and Writing Practices
Authors: Gregson Nicky A , Simonsen Kirsten , Vaiou Dina
Published: January 2017

In this paper we explore how existing, loosely geographical, English-language journals constitute Europe within their writing/publishing spaces. Focusing on two sets of journals - British/British-North American and those which are explicitly (pro) European in their orientation/content - we show how some of these journals appear to write contemporary Europe out of their spaces, casting Europe instead through the homogenizing lens of 19th-century colonialism. By contrast, others make more or less space for contemporary Europe but construe this as a transparent space; to be written about and framed by distant, dislocated commentator-viewers, whose power to comment and frame is regulated by their location within specific European geographical communities. Correspondingly, we argue that these journal spaces are both constituted through a centre-margin imaginary and constitutive of this power-geometry. This situation is argued to reflect academic working practices that are largely national or within-culture rather than cross-culture, and to reproduce dominant (Northern/Western) representations of Europe. In the final section of the paper, drawing on some of our own experiences, we consider how cross-cultural writing practices have the potential to disrupt this power geometry.
European Integration and New Forms of Uneven Development: But Not the End of Territorially Distinctive Capitalisms in Europe
Authors: Hudson Ray
Published: January 2017

Historically, capitalism developed territorially specific forms in Europe. The project of the European Union can be seen as one that seeks to erode this specificity. There is evidence of a tendency towards regulatory convergence but also of counter-tendencies, partly a product of the contradictory character of EU expansion and deepening economic integration. The end product has been a multiscalar system of governance and regulation, conjoining the EU, national and sub-national scales. There is also some evidence of convergence in national economic structures and performance. However, there is no evidence of convergence in economic performance and structures at sub-national levels. The legacies of past uneven development, allied to the effects of intensified market competition as companies seek to exploit differences between places, have produced new forms of uneven development.
Reshaping London's Economic Governance: The Role of the London Development Agency
Authors: Syrett Stephen , Baldock Robert
Published: January 2017

The shift towards network forms of urban and regional governance operating in a multi-level manner across different spatial scales and sectors is now well observed. For London, the system of network governance that developed from the 1980s appeared poorly positioned to respond to the particular challenges faced by world cities of retaining international competitiveness and dealing with increased social polarization. The restoration of pan-London strategic governance in 2000 initiated a phase of intense evolution in economic governance as the result of the creation of a Mayor and associated agency, the London Development Agency (LDA), to take the lead role for economic development and regeneration activity in the capital. This article analyses the emerging governance arrangements within London to illustrate the evolutionary and path-dependent nature of change through the interaction of national political and constitutional contexts, local conditions and wider processes of global change. The article argues that the potential of reinvigorated city-level economic governance within London is heavily constrained by the manner in which power was devolved by the central state. In its attempts to provide a strategic, lead role for London's economic development, the Mayor and the LDA must operate within a network governance system characterized by strong central control and a reliance on a complex array of partners operating across scales and sectors to deliver its economic strategy.
A computational treatment of generalized reference
Authors: Hausser Roland
Published: January 2017

Purpose

Medieval logic defined reference as a relation between language and objects in the world. Recently, however, the term ``representational token'' has been used instead of language (Reimer and Michaelson in The stanford encyclopedia of philosophy: winter 2014 edition. http://plato.stanford.edu/entries/reference/, 2014). This allows for reference with and without language. In a similar vein, Database Semantics (DBS) has implemented concept-based reference as a matching between two contents. If a content is attached to a language surface it is called the literal meaning$$_{1}$$

1

of the surface.

Methods

Referring with a content (as a representational token), regardless of whether or not it is attached to a surface, leads to a generalized notion of reference. An example of reference without language is identifying a current nonlanguage recognition with something seen before. Another example is identifying a nonlanguage recognition with an earlier language content, e.g. something read (for example, in a guide book) or heard about.

Results

In addition to the concept-based reference mechanism of (i) symbols [We follow the terminology used by Peirce (CP 2.228, 2.229, 5.473) for his theory of signs.] (“Reference by matching (symbol)” section), natural language uses the reference mechanisms of (ii) indexicals (“Reference by pointing (indexical)” section) based on pointers, and of (iii) names (“Reference by baptism (name)” section) based on acts of generalized baptism. A fourth kind of reference is co-reference (“Reference by address (coreference)” section), based on identity implemented by means of an address; it occurs as a variant of referring with indexicals and symbols, and is the foundation of name-based reference.

Conclusions

This paper systematically reconstructs the mechanisms of reference as they function with and without language in an agent-based computational framework. Language-dependent surfaces play a role only in the automatic word form recognition of the hear mode and the automatic word form production of the speak mode. In conclusion, the agent-based reconstruction of reference is applied to the medieval distinction between de dicto and de re (“De dicto/de re” section).
An analysis of the evaluation contexts in academic discourse
Authors: Xu Xiaoyu , Nesi Hilary
Published: January 2017

This paper develops a new framework to examine the use of ‘evaluation resources’ in research discourse. In previous studies of evaluative resources, two distinct, although interwoven, types of context have been identified: 1) the real world where evaluation resources are used to describe situations, and 2) the research world studying the real world, where they are used to engage readers and open up debate. In this paper, we will propose three context types: 1) the research world, where the choice of evaluation must be affected by the writer’s argumentative intention, 2) the real world where the choice of evaluation is affected by the writer’s argumentative intention, and 3) the real world where the choice of evaluation is not affected by the writer’s argumentative intention. This distinction helps us identify more rigorously those evaluative resources that are relevant to arguments. It will also enable us to explore and quantify the way evaluation functions across contexts.
Biomaterials and tissue engineering for scar management in wound care
Authors: Rahimnejad Maedeh , Derakhshanfar Soroosh , Zhong Wen
Published: January 2017

Scars are a natural and unavoidable result from most wound repair procedures and the body’s physiological healing response. However, they scars can cause considerable functional impairment and emotional and social distress. There are different forms of treatments that have been adopted to manage or eliminate scar formation. This review covers the latest research in the past decade on using either natural agents or synthetic biomaterials in treatments for scar reduction.
Opportunities and pitfalls in surface-wave interpretation
Authors: Schuster Gerard T. , Li Jing , Lu Kai , Metwally Ahmed , AlTheyab Abdullah , Hanafy Sherif
Published: January 2017

Many explorationists think of surface waves as the most damaging noise in land seismic data. Thus, much effort is spent in designing geophone arrays and filtering methods that attenuate these noisy events. It is now becoming apparent that surface waves can be a valuable ally in characterizing the near-surface geology. This review aims to find out how the interpreter can exploit some of the many opportunities available in surface waves recorded in land seismic data. For example, the dispersion curves associated with surface waves can be inverted to give the S-wave velocity tomogram, the common-offset gathers can reveal the presence of near-surface faults or velocity anomalies, and back-scattered surface waves can be migrated to detect the location of near-surface faults. However, the main limitation of surface waves is that they are typically sensitive to S-wave velocity variations no deeper than approximately half to one-third the dominant wavelength. For many exploration surveys, this limits the depth of investigation to be no deeper than approximately 0.5–1.0 km.
Modeling the interaction between presalt seamounts and gravitational failure in salt-bearing passive margins: The Messinian case in the northwestern Mediterranean Basin
Authors: Ferrer Oriol , Gratacós Oscar , Roca Eduard , Muñoz Josep Anton
Published: January 2017

The northwest Mediterranean Basin includes a thick Messinian salt sequence composed of three evaporitic units. From these, the intermediate unit, which is dominantly composed of halite, acted as a gravitational detachment favoring the downslope failure of the overlying sediments in a thin-skinned deformation regime. As a result, the structure of the margin is characterized by an upper extensional domain with basinward-dipping listric normal faults and a lower contractional domain that accommodates upslope extension by folding, salt inflation, or diapir squeezing. Lower to middle Miocene volcanic seamounts (presalt reliefs) located at the upper extensional domain locally disrupted the evaporitic units and produced salt flow perturbations. They acted as passive buttresses during the gravitational failure modifying the structural zonation of the margin. Using an experimental approach (sandbox models), we analyze the role played by seamounts during the kinematic evolution of passive margins and how they alter salt flow and suprasalt deformation during gravitational gliding. The experiments found that the seamounts locally interrupt the structural zonation of the margin because they hindered downdip salt flow during early deformation. Seamounts initially compartmentalize the margin architecture, resulting in the development of two gravitational subsystems with two extensional/contractional pairs that are subsequently reconnected when the accumulation of salt analog upslope of the relief is enough to overthrust it. From this point onward, the cover is passively translated downslope as a regional system. The changes in the viscous layer flow velocity related to the dip differences between the flanks and edges of the seamount determine the kinematic evolution of this system. Our experiments also provide geometric constraints to consider during interpretation of these structures, which are commonly poorly imaged in seismic data.
The significance of switch in convergence direction in the Alborz Mountains, northern Iran: Insights from scaled analogue modeling
Authors: Shahpasandzadeh Majid , Koyi Hemin , Nilfouroushan Faramarz
Published: January 2017

The switch in direction of convergence between Central Iran and the Eurasian Plate is believed to have a significant impact on the structural style in the Alborz Mountains, in the north of Iran. To understand the deformation pattern and investigate the influence of the South Caspian Basin kinematics since the middle Miocene on the structural styles and active tectonics of the Alborz Mountains, a series of scaled analogue models were prepared, in which passively layered loose sand simulating the sedimentary units were subjected to orthogonal and subsequently oblique shortening by a rigid indenter. Model results indicate that during the shortening, an arcuate-shaped foreland-vergent imbricate stack forms in front of the indenter. The orthogonal shortening is characterized by a prevailing right-lateral and left-lateral oblique-slip motion in the east and west of the model, respectively. This shift in kinematics contradicts the proposed preneotectonic (orthogonal) model of the Alborz. However, during oblique shortening, model results show that deformation is mainly accommodated by left-lateral transpression within the sand wedge and internal deformation. Oblique shortening is consistently accommodated by continued left-lateral motion on the west-northwest-trending oblique thrusts, whereas the east–west-trending thrusts and the preexisting east-northeast-trending right-lateral oblique thrusts reactivate as left-lateral oblique faults. Precise monitoring of the model surface also illustrates partitioning of shortening into the foreland-vergent left-lateral thrusting in the south and hinterland-vergent back thrusting in the north. These model results are generally consistent with field observations and GPS data of structure and kinematics of the Alborz Mountains.
Dynamic analysis of the mesenchymal-epithelial transition of blood-brain barrier forming glia inDrosophila
Authors: Schwabe Tina , Li Xiaoling , Gaul Ulrike
Published: January 2017

During development, many epithelia are formed by a mesenchymal-epithelial transition (MET). Here, we examine the major stages and underlying mechanisms of MET during blood-brain barrier formation in Drosophila. We show that contact with the basal lamina is essential for the growth of the barrier-forming subperineurial glia (SPG). Septate junctions (SJs), which provide insulation of the paracellular space, are not required for MET, but are necessary for the establishment of polarized SPG membrane compartments. In vivo time-lapse imaging reveals that the Moody GPCR signalling pathway regulates SPG cell growth and shape, with different levels of signalling causing distinct phenotypes. Timely, well-coordinated SPG growth is essential for the uniform insertion of SJs and thus the insulating function of the barrier. To our knowledge, this is the first dynamic in vivo analysis of all stages in the formation of a secondary epithelium and of the key role trimeric G protein signalling plays in this important morphogenetic process.
Developmental differences in dynamic muscle-tendon behavior: implications for movement efficiency
Authors: Waugh C. M. , Korff T. , Blazevich A. J.
Published: January 2017

Children perform cyclic motor tasks less efficiently than adults, however the mechanisms underlying such differences are not fully understood. One mechanism that may contribute these age-related differences is a differential contribution of muscles and tendons to a given muscle tendon unit (MTU) excursion. The aims of this study were to a) compare muscle and tendon excursion between children and adults performing vertical hopping, and b) determine if children and adults choose a hopping frequency that maximizes movement efficiency, based on the utilization of energy-saving mechanisms. 12 children (8.8±0.3 y) and 12 adults (26.0±2.1 y) performed 20 s of two-legged hopping at a self-selected frequency and at 1.33, 2.00, 2.67 and 3.33 Hz. Gastrocnemius medialis MTU excursion was estimated from kinematic data and muscle and tendon excursions were derived using a combination of 3D-motion capture and ultrasonography. Optimum hopping frequency was determined as the frequency which maximized surrogate measures of elastic energy storage potential of the tendon and minimized muscle excursion. Adults presented a significantly greater potential for elastic energy storage in combination with lower muscle excursion than children at their self-selected frequency, suggesting that children do not utilize these energy-saving mechanisms as effectively as adults. However, tendon elastic energy storage was maximized and muscle excursion minimized at preferred frequency both in children and adults, indicating that children may select their preferred hopping frequency based on the same criteria as adults. These findings increase our understanding of the mechanisms contributing to the higher energy cost of movement performance in children, and have implications for the interpretation of age-related differences in complex task performance.
Ultraviolet and yellow reflectance but not fluorescence is important for visual discrimination of conspecifics by Heliconius erato
Authors: Finkbeiner Susan D. , Fishman Dmitry A. , Osorio Daniel , Briscoe Adriana D.
Published: January 2017

Toxic Heliconius butterflies have yellow hindwing bars that – unlike their closest relatives – reflect ultraviolet (UV) and long wavelength light, and also fluoresce. The pigment in the yellow scales is 3-hydroxy-DL-kynurenine (3-OHK), found also in the hair and scales of a variety of animals. In other butterflies like pierids with color schemes characterized by independent sources of variation in UV and human-visible yellow/orange, behavioral experiments have generally implicated the UV component as most relevant to mate choice. This has not been addressed in Heliconius butterflies, where variation exists in analogous color components, but moreover where fluorescence due to 3-OHK could also contribute to yellow wing coloration. In addition, the potential cost due to predator visibility is largely unknown for the analogous well-studied pierid butterfly species. In field studies with butterfly paper models we show that both UV and 3-OHK yellow act as signals for H. erato but attack rates by birds do not differ significantly between the models. Furthermore, measurement of the quantum yield and reflectance spectra of 3-OHK indicates that fluorescence does not contribute to the visual signal under broad-spectrum illumination. Our results suggest that the use of 3-OHK pigmentation instead of ancestral yellow was driven by sexual selection rather than predation.
RNA-binding specificity landscape of the pentatricopeptide repeat protein PPR10
Authors: Miranda Rafael G. , Rojas Margarita , Montgomery Michael P. , Gribbin Kyle P. , Barkan Alice
Published: January 2017

Pentatricopeptide repeat (PPR) proteins comprise a large family of helical repeat proteins that influence gene expression in mitochondria and chloroplasts. PPR tracts can bind RNA via a modular one repeat–one nucleotide mechanism in which the nucleotide is specified by the identities of several amino acids in each repeat. This mode of recognition, the so-called PPR code, offers opportunities for the prediction of native PPR binding sites and the design of proteins to bind specified RNAs. However, a deep understanding of the parameters that dictate the affinity and specificity of PPR–RNA interactions is necessary to realize these goals. We report a comprehensive analysis of the sequence specificity of PPR10, a protein that binds similar RNA sequences of ∼18 nucleotides (nt) near the chloroplast atpH and psaJ genes in maize. We assessed the contribution of each nucleotide in the atpH binding site to PPR10 affinity in vitro by analyzing the effects of single-nucleotide changes at each position. In a complementary approach, the RNAs bound by PPR10 from partially randomized RNA pools were analyzed by deep sequencing. The results revealed three patches in which nucleotide identity has a major impact on binding affinity. These include 5 nt for which protein contacts were not observed in a PPR10–RNA crystal structure and 4 nt that are not explained by current views of the PPR code. These findings highlight aspects of PPR–RNA interactions that pose challenges for binding site prediction and design.
Analysis of Dental Maturation in Relation to Sagittal Jaw Relationships
Authors: Durka-Zając Magdalena , Derwich Marcin , Mituś-Kenig Maria , Łoboda Magdalena , Pawłowska Elżbieta
Published: January 2017

Background: The degree of mineralization of permanent tooth germs in dental age assessment has been an area of interest among many authors for years. However, only recently have researchers attempted to determine the potential interdependencies between dental age and jaw relationships. The aim of this work was to compare dental maturation in patients with skeletal Class II to patients with skeletal Classes I and III.

Material/Methods: The study involved 150 patients who sought orthodontic treatment. Dental age was assessed from panoramic radiographs using the Demirjian’s method. Skeletal class was evaluated according to the value of the ANPg angle from the Björk’s analysis. We used the analysis of variance (ANOVA) and the Student’s t-test.

Results: The mean dental age in patients with skeletal Class III was significantly higher than the mean dental age in patients with skeletal Class II (p<0.0005). A correlation between the dental age and chronological age was established. The weakest correlation was seen between the dental age and skeletal Class II. Among patients with skeletal Class II, the strongest correlation was found between chronological age and the formation of the germ of the second lower premolar (r=0.67; p<0.001).

Conclusions: Dental age among patients with skeletal Class II was the lowest.
Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies
Authors: Mayne E. , Memarzadeh A. , Raut P. , Arora A. , Khanduja V.
Published: January 2017

Objectives

The aim of this study was to systematically review the literature on measurement of muscle strength in patients with femoroacetabular impingement (FAI) and other pathologies and to suggest guidelines to standardise protocols for future research in the field.

Methods

The Cochrane and PubMed libraries were searched for any publications using the terms ‘hip’, ‘muscle’, ‘strength’, and ‘measurement’ in the ‘Title, Abstract, Keywords’ field. A further search was performed using the terms ‘femoroacetabular’ or ‘impingement’. The search was limited to recent literature only.

Results

A total of 29 articles were reviewed to obtain information on a number of variables. These comprised the type of device used for measurement, rater standardisation, the type of movements tested, body positioning and comparative studies of muscle strength in FAI versus normal controls. The studies found that hip muscle strength is lower in patients with FAI; this is also true for the asymptomatic hip in patients with FAI.

Conclusions

Current literature on this subject is limited and examines multiple variables. Our recommendations for achieving reproducible results include stabilising the patient, measuring isometric movements and maximising standardisation by using a single tester and familiarising the participants with the protocol. Further work must be done to demonstrate the reliability of any new testing method. Cite this article: E. Mayne, A. Memarzadeh, P. Raut, A. Arora, V. Khanduja. Measuring hip muscle strength in patients with femoroacetabular impingement and other hip pathologies: A systematic review. Bone Joint Res 2017;6:66–72. DOI: 10.1302/2046-3758.61.BJR-2016-0081.
Effects of early‐life exposure to THIP on brainstem neuronal excitability in the Mecp2‐null mouse model of Rett syndrome before and after drug withdrawal
Authors: Zhong Weiwei , Johnson Christopher M. , Cui Ningren , Oginsky Max F. , Wu Yang , Jiang Chun
Published: January 2017

Rett syndrome (RTT) is mostly caused by mutations of the X‐linked MECP2 gene. Although the causal neuronal mechanisms are still unclear, accumulating experimental evidence obtained from Mecp2−/Y mice suggests that imbalanced excitation/inhibition in central neurons plays a major role. Several approaches may help to rebalance the excitation/inhibition, including agonists of GABAA receptors (GABAAR). Indeed, our previous studies have shown that early‐life exposure of Mecp2‐null mice to the extrasynaptic GABAAR agonist THIP alleviates several RTT‐like symptoms including breathing disorders, motor dysfunction, social behaviors, and lifespan. However, how the chronic THIP affects the Mecp2−/Y mice at the cellular level remains elusive. Here, we show that the THIP exposure in early lives markedly alleviated hyperexcitability of two types of brainstem neurons in Mecp2−/Y mice. In neurons of the locus coeruleus (LC), known to be involved in breathing regulation, the hyperexcitability showed clear age‐dependence, which was associated with age‐dependent deterioration of the RTT‐like breathing irregularities. Both the neuronal hyperexcitability and the breathing disorders were relieved with early THIP treatment. In neurons of the mesencephalic trigeminal nucleus (Me5), both the neuronal hyperexcitability and the changes in intrinsic membrane properties were alleviated with the THIP treatment in Mecp2‐null mice. The effects of THIP on both LC and Me5 neuronal excitability remained 1 week after withdrawal. Persistent alleviation of breathing abnormalities in Mecp2−/Y mice was also observed a week after THIP withdrawal. These results suggest that early‐life exposure to THIP, a potential therapeutic medicine, appears capable of controlling neuronal hyperexcitability in Mecp2−/Y mice, which occurs in the absence of THIP in the recording solution, lasts at least 1 week after withdrawal, and may contribute to the RTT‐like symptom mitigation.
Intracellular oxygen tension limits muscle contraction‐induced change in muscle oxygen consumption under hypoxic conditions during Hb‐free perfusion
Authors: Takakura Hisashi , Ojino Minoru , Jue Thomas , Yamada Tatsuya , Furuichi Yasuro , Hashimoto Takeshi , Iwase Satoshi , Masuda Kazumi
Published: January 2017

Under acute hypoxic conditions, the muscle oxygen uptake (mO2) during exercise is reduced by the restriction in oxygen‐supplied volume to the mitochondria within the peripheral tissue. This suggests the existence of a factor restricting the mO2 under hypoxic conditions at the peripheral tissue level. Therefore, this study set out to test the hypothesis that the restriction in mO2 is regulated by the net decrease in intracellular oxygen tension equilibrated with myoglobin oxygen saturation (∆PmbO2) during muscle contraction under hypoxic conditions. The hindlimb of male Wistar rats (8 weeks old, n = 5) was perfused with hemoglobin‐free Krebs–Henseleit buffer equilibrated with three different fractions of O2 gas: 95.0%O2, 71.3%O2, and 47.5%O2. The deoxygenated myoglobin (Mb) kinetics during muscle contraction were measured under each oxygen condition with a near‐infrared spectroscopy. The ∆[deoxy‐Mb] kinetics were converted to oxygen saturation of myoglobin (SmbO2), and the PmbO2 was then calculated based on the SmbO2 and the O2 dissociation curve of the Mb. The SmbO2 and PmbO2 at rest decreased with the decrease in O2 supply, and the muscle contraction caused a further decrease in SmbO2 and PmbO2 under all O2 conditions. The net increase in mO2 from the muscle contraction (∆mO2) gradually decreased as the ∆PmbO2 decreased during muscle contraction. The results of this study suggest that ΔPmbO2 is a key determinant of the ΔmO2.