bluuebunny/crossref_metadata_2025 huggingface dataset:
The effect of photoperiod regimes on daily RNA:DNA ratio rhythms in Chinese soft-shelled turtles (Pelodiscus sinensis)
Authors: Ji Fangshuo , Liu Haiyan , Li Chao , Yang Zhencai
Published: May 2017

The ratio of RNA to DNA is widely used to reflect instantaneous animal growth; however, little is known about its daily variation. Photoperiod can modify expression of internal clocks, providing animals with the flexibility to adapt to variable environments. This study focused on the influence of photoperiod regimes on the daily variation of RNA:DNA ratio in Pelodiscus sinensis. We randomly divided 260 turtles into four groups: constant dark (0L), 8 h light with 16 h dark (8L), 12 h light with 12 h dark (12L), and 16 h light with 8 h dark (16L). Turtles were housed under specific photoperiods for 15 days (fed for first 10 days then starved for 5 days), thereafter we sampled the tissues every 2 h for 24 h. We dissected forelimb muscles and measured the concentration of isolated RNA and DNA. There were rhythmic variations in the RNA:DNA ratio, even in turtles under continuous darkness, indicating that P. sinensis has circadian RNA:DNA ratio rhythms, and the rhythms were likely controlled by internal clocks. Additionally, the acrophase was advanced by two hours in constant darkness in contrast to the other three photoperiods, indicating that the photoperiod considerably modified the rhythm set by the internal clocks. Notably, the RNA:DNA ratio differed between photoperiod regimes, with 0L > 16L > 8L ≈ 12L, indicating the photoperiod may be a seasonal indicator for turtles to synchronize their physiological processes with environmental variations.
The spatial-and-ethological population structure, cooperation, and the evolution of sociality in rodents
Authors: Gromov Vladimir S.
Published: May 2017

There are two types of complex social units — aggregations and family groups — in rodent populations, with an essential difference in their social organization. The impact of ecological factors on the evolution of sociality in rodents (the transition from solitary towards family-group lifestyle) is still unclear. The inter-specific comparative analysis based on quantification of social traits related to the spatial-and-ethological population structure and cooperation allows author to propose a new conceptual approach to the assessment of differences between the species under consideration in terms of the evolution of sociality. A new conceptual model of the evolution of sociality in rodents should incorporate ecological conditions and social factors, including cooperation, operating as a complex of selective forces promoting formation of family groups.
The Role of African Regional Organizations in the Promotion and Protection of Foreign Investment
Authors: Denters Erik , Gazzini Tarcisio
Published: May 2017

A complex, fragmented and heterogeneous network of domestic and international legal instruments promotes and protects foreign investment in Africa. While bilateral treaties seem to be increasingly unpopular, regionalism is clearly on the rise in the continent. The article examines how regional treaties have contributed to upgrade the current regulation of foreign investment. From this perspective, Africa can be seen as a normative laboratory. Regional treaties, most prominently those concluded within the Economic Community of West African States (ECOWAS) and the Southern African Development Community (SADC), contain several important novelties meant to rebalance the rights and obligations of the various stakeholders as well as to safeguard host State policy space. The content of these treaties has been brought more in line with the evolution of international law, especially with regard to the protection of the environment, social and human rights, transparency, corruption, public scrutiny, economic development, and corporate responsibility.
Fair and Equitable Treatment and (Full) Protection and Security in African Investment Treaties Between Generality and Contextual Specificity
Authors: De Brabandere Eric
Published: May 2017

This article seeks to test whether African investment treaties present a specific approach – i.e. distinct from the North-American and Western Hemisphere – to fair and equitable treatment (FET) and (full) protection and security (FPS). The first main argument is that the concepts of FET and FPS are not substantially impacted by the mere fact of being included in investment agreements to which African States are party. The second main argument is that the understanding, interpretation and definitions of these concepts within Africa is not fundamentally different than in other regions. Thirdly, notwithstanding the similarity in the wording of these standards of treatment in African investment treaties, there may still be room for taking into account the specific circumstances of the States in which the investment is made, including the level of development of the host State.
Archetypal Analysis: Mining Weather and Climate Extremes
Authors: Hannachi A. , Trendafilov N.
Published: May 2017

Conventional analysis methods in weather and climate science (e.g., EOF analysis) exhibit a number of drawbacks including scaling and mixing. These methods focus mostly on the bulk of the probability distribution of the system in state space and overlook its tail. This paper explores a different method, the archetypal analysis (AA), which focuses precisely on the extremes. AA seeks to approximate the convex hull of the data in state space by finding “corners” that represent “pure” types or archetypes through computing mixture weight matrices. The method is quite new in climate science, although it has been around for about two decades in pattern recognition. It encompasses, in particular, the virtues of EOFs and clustering. The method is presented along with a new manifold-based optimization algorithm that optimizes for the weights simultaneously, unlike the conventional multistep algorithm based on the alternating constrained least squares. The paper discusses the numerical solution and then applies it to the monthly sea surface temperature (SST) from HadISST and to the Asian summer monsoon (ASM) using sea level pressure (SLP) from ERA-40 over the Asian monsoon region. The application to SST reveals, in particular, three archetypes, namely, El Niño, La Niña, and a third pattern representing the western boundary currents. The latter archetype shows a particular trend in the last few decades. The application to the ASM SLP anomalies yields archetypes that are consistent with the ASM regimes found in the literature. Merits and weaknesses of the method along with possible future development are also discussed.
The Effects of Gendered Occupational Roles on Men’s and Women’s Workplace Authority: Evidence from Microfinance
Authors: Doering Laura , Thébaud Sarah
Published: May 2017

The gendering of occupational roles affects a variety of outcomes for workers and organizations. We examine how the gender of an initial role occupant influences the authority enjoyed by individuals who subsequently fill that role. We use data from a microfinance bank in Central America to examine how working initially with a male or female loan manager shapes borrowers’ compliance with future managers’ directives. First, we show that borrowers originally paired with female managers continue to be less compliant with subsequent managers, regardless of subsequent managers’ gender. Next, we demonstrate how compliance is shaped by the gender-typing of the role and the gender of the individual who fills that role. We find that men enjoy significantly greater compliance in male-typed roles, but male and female managers experience similar levels of compliance in female-typed roles. Further analyses reveal that these gendered patterns become especially pronounced after managers demonstrate their authority by disciplining borrowers. Overall, we show how quickly gendered expectations become inscribed into occupational roles, and we identify their lasting organizational consequences. More broadly, we suggest authority mechanisms that may contribute to the “stalled” gender revolution in the workplace.
Paradoxical Processes Impeding Public Management Reform Implementation: Perspectives of Management Consultants
Authors: Kuna Shani
Published: May 2017

While the literature highlights the complexity of new public management (NPM) reform implementation, relatively little is known about these processes from the perspective of management consultants. Based on two complementary approaches, change management theory and paradox theory, this exploratory study seeks to understand the role of management consultants in identifying impediments to reform implementation and their potential contribution to addressing implementation challenges. In-depth interviews were conducted with external management consultants specializing in public management reform implementation in Israel. The findings expose the paradoxical nature of the cycles which emerge, as new practices of efficiency implemented under NPM generate counter-practices of deficiency. Management consultants assist public managers in acquiring leadership skills for managing paradoxes. The study may contribute to our understanding of why reforms often fail and how public managers can confront such challenges. Theoretical insights and practical implications are discussed.
Age Diversity in the Workplace: The Effect of Relational Age Within Supervisor–Employee Dyads on Employees’ Work Engagement
Authors: Yang Jie , Matz-Costa Christina
Published: May 2017

Although having a younger supervisor or a supervisor of a similar age runs counter to the traditional older supervisor–younger subordinate norm, it is becoming increasingly common in the 21st-century workplace. The current study uses theories of relational demography and relational norms as well as Selective Optimization with Compensation theory and the job demands-resources model to understand how relational age within supervisor–employee dyads influences workers’ engagement. Cross-sectional data from a multiworksite (U.S.-based) sample of 2,195 workers aged 18 to 81 years were used to estimate ordinary least squares regression models. After accounting for a variety of factors that could influence engagement levels (i.e., demographics, health status, and job or personal resources), findings indicated that employees with similar-age supervisors were less engaged than employees with older supervisors. Moreover, while employees who did not know the ages of their supervisors were just as engaged as employees with older supervisors. Implications for engaging an age-diverse workforce are discussed.
Teaching Psychology and Law
Authors: Zelechoski Amanda D. , Riggs Romaine Christina L. , Wolbransky Melinda
Published: May 2017

Given the recent proliferation of undergraduate psychology and law courses, there is an increased need to empirically evaluate effective methods of teaching psycholegal material. The current study used a between- and within-subject design across four higher education institutions ( N = 291 students) to evaluate the effectiveness of incorporating experiential learning activities in undergraduate psychology and law courses. Students who participated in the experiential activities performed significantly better than did control students on exam questions related to some, but not all, of the activities. In addition, experiential students consistently rated aspects of the course as more enjoyable than did control students. Results suggest that the inclusion of experiential learning activities has the potential to improve student performance and increase interest and motivation.
A Framework for Treatment Decision Making at Prostate Cancer Recurrence
Authors: Lange Jane M. , Trock Bruce J. , Gulati Roman , Etzioni Ruth
Published: May 2017

Background. Of the 50,000 men in the US who elect for radical prostatectomy for prostate cancer, 24% to 40% will have a prostate-specific antigen (PSA) recurrence (PSA-R) within 10 years. Deciding whether to administer salvage therapy (ST) at PSA-R presents challenges, as treatment reduces the risk of progression to clinical metastasis but incurs unnecessary side effects should the man die before metastasis. We have developed a new harm–benefit framework using a clinical cohort to inform shared decision making between patients and physicians at PSA-R. Methods. Records of 1,045 Johns Hopkins University Hospital patients diagnosed between 1984 and 2013 who had PSA-R following radical prostatectomy were analyzed using marginal structural models to estimate the baseline risk of metastasis and the effect of ST (radiation therapy with or without hormone therapy) while accounting for selection into ST on the basis of PSA growth. The estimated model predicts the harm–benefit tradeoffs of ST within patient subgroups. The benefit of ST is the absolute reduction in the risk of metastasis within 10 years; the harm is the frequency of cancers that would not have metastasized in the patient’s lifetime in the absence of ST (overtreatment). Results. The adjusted hazard ratio associated with ST was 0.41 (95% CI, 0.31 to 0.55). Providing ST to all men at PSA-R reduced the risk of metastasis from 43% to 23% but led to 31% of men being overtreated (harm/benefit = 31/(43−23) = 1.6). Providing ST to men with Gleason score >7 reduced the risk of metastasis from 67% to 39%, with 13% of men being overtreated (harm/benefit = 13/(67−39) = 0.5). Conclusions. A quantitative framework that evaluates primary harms and benefits of ST after PSA-R will facilitate informed decision making. Immediate ST may be more appropriate in patient subgroups at elevated risk of metastasis.
Marketing
Authors: Shultz Clifford J.
Published: May 2017

This invited commentary is a reflection on and response to an essay on “The Long Macro View”, by Robert Lusch, who articulated key themes of human, societal and marketing evolution, and challenges marketing scholars to consider ways to reduce costs inflicted by prolific human activity, particularly (marketing) exchange. Those costs cumulatively pose existential threats to humanity; they also present opportunities, which potentially can be redressed by better understanding of conflict resolution theory, relevant marketing applications to reduce social conflict, and guidance by complementary macromarketing precepts. Consistent with some ideas in the aforementioned essay, the author of this commentary argues for constructive engagement by individuals, organizations and governments via institutional entrepreneurship, which is crucial to enhance the efficiency, effectiveness, fairness and sustainability of a complex and increasingly global macromarketing system, and the well-being and long-term survival of Homo Sapiens.
School Refusal Assessment Scale–Revised Chilean Version: Factorial Invariance and Latent Means Differences Across Gender and Age
Authors: Gonzálvez Carolina , Kearney Christopher A. , Lagos-San Martín Nelly , Sanmartín Ricardo , Vicent María , Inglés Cándido J. , García-Fernández José M.
Published: May 2017

The School Refusal Assessment Scale–Revised (SRAS-R) is a self-report measure designed to assess four functional factors of school refusal behavior: avoidance of stimuli that provoke negative affectivity (Factor I), escape from aversive social and/or evaluative situations (Factor II), pursuit of attention from significant others (Factor III), and pursuit of tangible reinforcement outside of school (Factor IV). The aim was to analyze the scale’s factorial invariance and latent means differences across gender and age in a sample of 2,678 Chilean adolescents aged 13 to 17 years ( M = 15.23; SD = 1.26). The hypothesized model revealed the best-fit model and remained invariant across gender and age. Good internal consistency was obtained for the four factors (.75, .72, .77, and .71). Latent means differences were found across gender and age.
Healthcare leadership and applied philosophy: An essential resource
Authors: Fistein Elizabeth , Malloy David Cruise
Published: May 2017

As healthcare professionals we are committed to the efficient and effective operation of our institutions. Bureaucratic structures, rules, regulations, policies, and of course, measurements, are the tools-at-hand. While there is nothing inherently pernicious about efficient, effective, and measured institutions, we argue what is critically missing in this environment is humanity and authenticity at the cost of meaningful work. The solutions we offer are found in the realm of philosophy and in particular that branch of philosophy that deals with first principles - what is a nurse; what is a patient; what is a hospital?
Transformations in Prison Subculture and Adjustment to Imprisonment in Post-Soviet Lithuanian Penitentiary Institutions
Authors: Vaičiūnienė Rūta , Tereškinas Artūras
Published: May 2017

As in other post-Soviet countries, carceral collectivism characterizes penal institutions in Lithuania. In these institutions, prisoners’ interactions are minimally controlled and convicts are responsible for the maintenance of order; hence, the informal rules of the criminal subculture prevail in Lithuanian correctional facilities. In this article, we examine the prison subculture and adaptation to imprisonment as a significant part of inmates’ social world in post-Soviet Lithuania. By using semi-structured interviews with male prisoners, semi-structured interviews with prison staff, and data from the inmates’ criminal records, we conceptualize both men’s adaptation to imprisonment and current transformations in the Lithuanian prison subculture. As our research shows, the importance of this subculture has decreased in recent years. This process has been influenced by structural changes such as stronger administrative control of convicts, their differentiation and division into smaller groups that limit their mutual contacts, and convicts’ motivation to obtain parole and participate in various rehabilitation programs. The prison subculture has also experienced transformations because of the increasing impact of financial resources on social life, subcultural rules, and interprisoner relationships. Despite these processes, the subculture still plays an important role in inmates’ attempts to choose different daily coping styles and types of adaptation to imprisonment. In this article, we argue that in reforming post-Soviet correctional institutions, a gradual transition to the system of individual cell–type confinement with some remaining elements of collective imprisonment would be desirable.
Vitamin D Status and Supplementation in Employer-Sponsored Wellness Program
Authors: Kaufman Harvey W. , Chen Zhen
Published: May 2017

Purpose:

To assess the response to information about vitamin D status by participants enrolled in employer-sponsored wellness programs.

Design:

A self-reported health risk assessment questionnaire was used to categorize vitamin D supplementation.

Participants:

A total of 50 209 participants of 12 employer-sponsored wellness programs that included vitamin D testing and services provided by Quest Diagnostics in 2014 and 2015.

Measures:

Vitamin D status based on laboratory testing results and responses to vitamin D supplementation in a health risk assessment questionnaire for initial and subsequent years.

Results:

Among 50 209 participants, 29% had deficient and 37% had suboptimal levels of vitamin D. Many participants appeared to act counter to their informed vitamin D status by starting supplements when vitamin D level was initially optimal (20%) or discontinuing supplements when vitamin D level was initially deficient (36%). Three-quarters of participants who had deficient or suboptimal vitamin D levels and were not taking supplements in 2014 continued not taking supplements in 2015.

Conclusion:

Deficient and suboptimal vitamin D levels remain prevalent in a working-age population. Many participants do not seem to be taking appropriate actions after receiving vitamin D testing results. Accordingly, employer-sponsored wellness programs have an opportunity to better educate participants.
In-vivo analysis of ankle joint movement for patient-specific kinematic characterization
Authors: Ferraresi Carlo , De Benedictis Carlo , Franco Walter , Maffiodo Daniela , Leardini Alberto
Published: May 2017

In this article, a method for the experimental in-vivo characterization of the ankle kinematics is proposed. The method is meant to improve personalization of various ankle joint treatments, such as surgical decision-making or design and application of an orthosis, possibly to increase their effectiveness. This characterization in fact would make the treatments more compatible with the specific patient’s joint physiological conditions. This article describes the experimental procedure and the analytical method adopted, based on the instantaneous and mean helical axis theories. The results obtained in this experimental analysis reveal that more accurate techniques are necessary for a robust in-vivo assessment of the tibio-talar axis of rotation.
Ethical dilemmas during cardiac arrest incidents in the patient’s home
Authors: Karlsson Mattias , Karlsson Niclas , Hilli Yvonne
Published: May 2017

Background:

The majority (70%) of cardiac arrests in Sweden are experienced in the patient’s home. In these situations, the ambulance nurses may encounter several ethical dilemmas.

Aim:

The aim was to investigate Swedish specialist ambulance nurses’ experiences of ethical dilemmas associated with cardiac arrest situations in adult patients’ homes.

Methods:

Nine interviews were conducted with specialist ambulance nurses at four different ambulance stations in the southeast region of Sweden. Data were analysed using content analysis.

Ethical considerations:

Ethical principles mandated by the Swedish Research Council were carefully followed during the whole process.

Findings:

Two main themes with six sub-themes were identified: The scene – creating a sheltered space for caring and Ethical decision-making. The results showed that ethical dilemmas might occur when trying to create a sheltered space to preserve the patients’ integrity and dignity. A dilemma could be whether or not to invite significant others to be present during the medical treatment. Ethical decision-making was dependent on good communication and ethical reasoning among all parties. In certain situations, decisions were made not to commence or to terminate care despite guidelines. The decision was guided by combining the medical/nursing perspectives and ethical competence with respect to the human being’s dignity and a will to do good for the patient. The nurses followed the voice of their heart and had the courage to be truly human.

Conclusion:

The ambulance nurses were guided by their ethos, including the basic motive to care for the patient, to alleviate suffering, to confirm the patient’s dignity and to serve life and health.
Theory of Mind and Empathy in Children With ADHD
Authors: Maoz Hagai , Gvirts Hila Z. , Sheffer Maya , Bloch Yuval
Published: May 2017

Objective: The current study compared empathy and theory of mind (ToM) between children with ADHD and healthy controls, and assessed changes in ToM among children with ADHD following administration of methylphenidate (MPH). Method: Twenty-four children with ADHD (mean age = 10.3 years) were compared with 36 healthy controls. All children completed the interpersonal reactivity index (IRI), a self-reported empathy questionnaire, and performed the “faux-pas” recognition task (FPR). Children with ADHD performed the task with and without MPH. Results: Children with ADHD showed significantly lower levels of self-reported empathy on most IRI subscales. FPR scores were significantly lower in children with ADHD and were improved, following the administration of MPH, to a level equal to that found in healthy controls. Conclusion: Children with ADHD show impaired self-reported empathy and FPR when compared with healthy controls. Stimulants improve FPR in children with ADHD to a level equal to that in healthy controls.
Queer contestation of neoliberal and heteronormative moral geographies during #occupygezi
Authors: Erol Ali E
Published: May 2017

During the summer of 2013, Turkey witnessed the largest protest movement in the history of the republic. The protests began with environmentalist concerns to save a public park in central Istanbul, Gezi Park, from becoming a shopping mall. However, in a matter of days, the protests turned into a reaction against what many protestors perceived to be the authoritarian rule of the prime minister at the time. While the mainstream protest discourses focused on reacting against such perceptions, which produced sexist and heterosexist discourses, queer discourses were centered on celebrating coexistence and diversity through resistance. Drawing on literatures of queer theory that focus on queer space and moral geography, this article builds on Foucault’s notion of heterotopic space. Using queer linguistics to investigate blog posts that were written at the time of the protest by queer individuals who were taking part in protest, this article investigates the ways in which queer discourses construct the moral geography of the Gezi Park and at the same time challenge neoliberal and heteronormative moral geographies.
Embodiment in qualitative research: collage making with migrant, refugee and asylum seeking women
Authors: Vacchelli Elena
Published: May 2017

This article draws on the creative methods deployed in the course of a research project aimed at mapping community-based mental health service provision and other specific services migrant, refugee and asylum seeking women regularly access in London. Although the study made use of a mixed method research design, only the art-based approach deployed as part of the focus groups is discussed. The article contributes to developing embodied research methods in that it explores the bodily engagement of research participants in making a collage and unpacks the implications of this approach for collecting qualitative data involving experiential activity. The body plays a central role in generating qualitative data through the making of the collage and collage-making represents an embodied experience suggesting that how we feel, how we perceive, how we relate to our own bodies and the place they have in the order of things – is contextual, gendered, relational, historically and culturally situated.
Accounting, Finance & Executive Compensation
Authors: Mills Roger
Published: May 2017

Is the misuse of stock options the cause of corporate failures such as Enron or WorldCom? Or are they a major factor in the success of tech Giants such as Microsoft? And if so, how can they be used properly and misuse prevented? In this Manager Update, Roger Mills answers these questions as well as shedding new light on the issue of executive compensation.
Driving Markets and Market Growth
Authors: Foreman Susan
Published: May 2017

The growth of a business is one of the key priorities of the marketing function. But how can companies coninue to grow through a focus on marketing? And what can managers do to ensure this happens? It is argued here that, in order to grow, companies should move from being market driven to driving markets themselves. In practice, this means a multidisciplinary approach that draws on branding, customer relationships and understanding trends.
Organisational Commitment
Authors: Mcbain Richard
Published: May 2017

Organisational commitment has long been established as a key factor leading to organisational success. But how can you define commitment and what components make it up? How do new working enviroments such as the setting up of call centres affect commitment? Critically, what can managers do to enhance commitment in these and more traditional environments? An approach based on mentoring may provide some of the answers.
Ethical considerations in qualitative case study research recruiting participants with profound intellectual disabilities
Authors: Haines David
Published: May 2017

Drawing on the author’s experience carrying out qualitative research in the field of occupational therapy with people with intellectual disabilities, this article explores ethical issues inherent in ethnographic and case study research, where study designs can evolve over time. Such qualitative methodologies can enable deep understanding of research topics, but detailed description of methods and of the range of potential experiences participants may have is necessary to ensure that they are fully informed and ethics committees satisfied. Thorough consideration is required of ethical issues related to topic relevance and design, recruitment, collection of data and portrayal of participants in the eventual case report. The article illustrates a way in which research of this type can be explained and justified, including how recruitment can be achieved of participants likely to lack capacity to consent to participation themselves.
Effect of BGM Accuracy on the Clinical Performance of CGM: An In-Silico Study
Authors: Campos-Náñez Enrique , Breton Marc D.
Published: May 2017

Background:

Standard management of type 1 diabetes (T1D) relies on blood glucose monitoring based on a range of technologies from self-monitoring of blood glucose (BGM) to continuous glucose monitoring (CGM). Even as CGM technology matures, patients utilize BGM for calibration and dosing. The question of how the accuracy of both technologies interact is still not well understood.

Methods:

We use a recently developed data-driven simulation approach to characterize the relationship between CGM and BGM accuracy especially how BGM accuracy impacts CGM performance in four different use cases with increasing levels of reliance on twice daily calibrated CGM. Simulations are used to estimate clinical outcomes and isolate CGM and BGM accuracy characteristics that drive performance.

Results:

Our results indicate that meter (BGM) accuracy, and more specifically systematic positive or negative bias, has a significant effect on clinical performance (HbA1c and severe hypoglycemia events) in all use-cases generated for twice daily calibrated CGMs. Moreover, CGM sensor accuracy can amplify or mitigate, but not eliminate these effects.

Conclusion:

As a system, BGM and CGM and their mode of use (use-case) interact to determine clinical outcomes. Clinical outcomes (eg, HbA1c, severe hypoglycemia, time in range) can be closely approximated by linear relationships with two BGM accuracy characteristics, namely error and bias. In turn, the coefficients of this linear relationship are determined by the use-case and by CGM accuracy (MARD).
Nursing Informatics: Ethical Considerations for Adopting Electronic Records
Authors: Wilburn Amber
Published: May 2017

School districts are commonly adopting electronic storage systems, including electronic health records. Included in this adoption is a move toward cloud-based record storage systems to handle the increasing volumes of data. Deciding which system to adopt is especially difficult in times of tightening school district budgets. While there are several options to consider, including the outright purchase of a proprietary system or choosing one of a relatively new group of free programs, lead nurses must work to ensure that student information is protected and that any chosen system complies with privacy laws. This article provides a case study and presents legal and ethical considerations related to maintaining the privacy of health records in the school setting.
A Hierarchical Integration of Person-Centered Comorbidity Models: Structure, Stability, and Transition Over Time
Authors: Kim Hyunsik , Eaton Nicholas R.
Published: May 2017

Person-centered analyses of mental disorder comorbidity typically identify a single optimal latent group structure. We took an alternate approach, modeling every estimable comorbidity class model in a nationally representative sample ( N = 34,653) and integrating them into a single overarching hierarchy, providing a full multilevel accounting of various person-centered comorbidity structures. We then investigated the structural stability of this hierarchy across two waves of data collection, and the stability of, and transition between, comorbidity classes over time using latent transition analysis. Findings suggested that comorbidity classes were structured into an interpretable hierarchy. Evidence for robust structural stability of the hierarchy over time was found, regardless of assessment time points and diagnostic time frames used. Latent transition analysis provided evidence for both continuity and change of comorbidity group membership. We discuss how person- and variable-centered models provide complementary perspectives toward empirically supported classification.
Correlation Between Lumbopelvic and Sagittal Parameters and Health-Related Quality of Life in Adults With Lumbosacral Spondylolisthesis
Authors: Gussous Yazeed , Theologis Alexander A. , Demb Joshua B. , Tangtiphaiboontana Jennifer , Berven Sigurd
Published: May 2017

Study Design:

Secondary analysis of prospective, multicenter data.

Objective:

To evaluate impact of sagittal parameters on health-related quality of life (HRQoL) in adults with lumbosacral spondylolisthesis.

Methods:

Adults with unoperated lumbosacral spondylolisthesis were identified in the Spinal Deformity Study Group database. Pearson’s correlations were calculated between SF-12 (Short Form–12)/Scoliosis Research Society–30 (SRS-30) scores and radiographic parameters (C7 sagittal vertical axis [SVA] deviation, T1 pelvic angle, pelvic tilt [PT], pelvic incidence, sacral slope, slip angle, Meyerding slip grade, Labelle classification). Main effects linear regression models measured association between individual health status measures and individual radiographic predictor variables.

Results:

Forty-five patients were analyzed (male, 15; female, 30; average age 40.5 ± 18.7 years; 14 low-grade, 31 high-grade). For low-grade slips, SVA had strong negative correlations with SF-12 mental component score (MCS), SRS-30 appearance, mental, and satisfaction domains ( r = −0.57, r = −0.60, r = −0.58, r = −0.53, respectively; P < .05). For high-grade slips, slip angle had a moderate negative correlation with SF-12 MCS ( r = −0.36; P = .05) and SVA had strong negative correlations with SF-12 physical component score (PCS), SRS-30 appearance and activity domains ( r = −0.48, r = −0.48, r = −0.45; P < .05) and a moderate negative correlation with SRS-30 total ( r = −0.37; P < .05). T1 pelvic angle had a moderate negative correlation with SF-12 PCS and SRS-30 appearance ( r = −0.37, r = −0.36; P ≤ .05). For every 1° increase in PT, there was a 0.04-point decrease in SRS appearance, 0.05-point decrease in SRS activity, 0.06-point decrease in SRS satisfaction, and 0.04-point decrease in SRS total score ( P < .05).

Conclusion:

Lumbosacral spondylolisthesis in adults negatively affects HRQoL. Multiple radiographic sagittal parameters negatively affect HRQoLs for patients with low- and high-grade slips. Improvement of sagittal parameters is an important goal of surgery for adults with lumbosacral spondylolisthesis.
Use of Intraoperative Ultrasound During Spinal Surgery
Authors: Vasudeva Viren S. , Abd-El-Barr Muhammad , Pompeu Yuri A. , Karhade Aditya , Groff Michael W. , Lu Yi
Published: May 2017

Study Design:

Review and technical report.

Objective:

Intraoperative ultrasound has been used by spine surgeons since the early 1980s. Since that time, more advanced modes of intraoperative imaging and navigation have become widely available. Although the use of ultrasound during spine surgery has fallen out of favor, it remains the only true real-time imaging modality that allows surgeons to visualize soft tissue anatomy instantly and continuously while operating. It is our objective to demonstrate that for this reason, ultrasound is a useful adjunctive technique for spine surgeons, especially when approaching intradural lesions or when addressing pathology in the ventral spinal canal via a posterior approach.

Methods:

Using PubMed, the existing literature regarding the use of intraoperative ultrasound during spinal surgery was evaluated. Also, surgical case logs were reviewed to identify spinal operations during which intraoperative ultrasound was used. Illustrative cases were selected and reviewed in detail.

Results:

This article provides a brief review of the history of intraoperative ultrasound in spine surgery and describes certain surgical scenarios during which this technique might be useful. Several illustrative cases are provided from our own experience.

Conclusions:

Surgeons should consider the use of intraoperative ultrasound when approaching intradural lesions or when addressing pathology ventral to the thecal sac via a posterior approach.
Should We Label All Synovial Cysts as Unstable?
Authors: Kulkarni Arvind G. , Dutta Shumayou , Dhruv Abhilash , Bassi Anupreet
Published: May 2017

Study Design:

Retrospective study.

Objective:

To analyze the various anatomical parameters that influence segmental stability in patients suffering from lumbar intra spinal cysts (LISCs) and to determine the outcome of microscopic unilateral laminotomy and cystectomy.

Methods:

All patients that were surgically managed for a LISC between 2007 and 2013 with more than 3 years of follow-up were reviewed. Those without associated instability were evaluated for segmental mobility, segmental angulation, facet inclination, stage of disc degeneration, and level of involvement on MRI and dynamic radiographs. Outcomes of unilateral laminotomy and cystectomy were evaluated using VAS (Visual Analogue Score), ODI (Oswestry Disability Index), and Macnabs criteria. Dynamic radiographs were performed in all cases pre- and postoperatively and at the last follow-up.

Results:

Thirty patients were operated for a LISC between 2007 and 2013. The levels involved were L4-5(23), L3-4(4) and L5-S1(3). The mean facet angle was 42.6 (± 6.1) degrees. The stage of disc degeneration was scattered haphazardly across all the cases (Gr 2[17]; Gr 3[1]; Gr 4[8]; Gr 5[4]). VAS and ODI scores improved significantly in all patients. Mean follow-up was 46.5 months (36-96 months). No patient developed postoperative instability at the last follow-up.

Conclusions:

The coronal inclination of the facet joints, absence of radiological instability, and poor co-relation with stages of disc degeneration suggests the presence of adequate residual stability. In this study, stand-alone decompression for LISCs without instability had well sustained good/excellent outcomes. Fusion is recommended for LISCs with associated instability.
Biomechanical Stability of a Stand-Alone Interbody Spacer in Two-Level and Hybrid Cervical Fusion Constructs
Authors: Kang Daniel G. , Wagner Scott C. , Tracey Robert W. , Cody John P. , Gaume Rachel E. , Lehman Ronald A.
Published: May 2017

Study Design:

In vitro human cadaveric biomechanical analysis.

Objective:

To evaluate the segmental stability of a stand-alone spacer (SAS) device compared with the traditional anterior cervical plate (ACP) construct in the setting of a 2-level cervical fusion construct or as a hybrid construct adjacent to a previous 1-level ACP construct.

Methods:

Twelve human cadaveric cervical spines (C2-T1) were nondestructively tested with a custom 6-degree-of-freedom spine simulator under axial rotation (AR), flexion-extension (FE), and lateral bending (LB) at 1.5 N m loads. After intact analysis, each specimen underwent instrumentation and testing in the following 3 configurations, with each specimen randomized to the order of construct: (A) C5-7 SAS; (B) C5-6 ACP, and C6-7 SAS (hybrid); (C) C5-7 ACP. Full range of motion (ROM) data at C5-C7 was obtained and analyzed by each loading modality utilizing mean comparisons with repeated measures analysis of variance with Sidak correction for multiple comparisons.

Results:

Compared with the intact specimen, all tested constructs had significantly increased segmental stability at C5-C7 in AR and FE ROM, with no difference in LB ROM. At C5-C6, all test constructs again had increased segmental stability in FE ROM compared with intact (10.9° ± 4.4° Intact vs SAS 6.6° ± 3.2°, P < .001; vs.Hybrid 2.9° ± 2.0°, P = .005; vs ACP 2.1° ± 1.4°, P < .001), but had no difference in AR and LB ROM. Analysis of C6-C7 ROM demonstrated all test groups had significantly greater segmental stability in FE ROM compared with intact (9.6° ± 2.7° Intact vs SAS 5.0° ± 3.0°, P = .018; vs Hybrid 5.0° ± 2.7°, P = .018; vs ACP 4.4° ± 5.2°, P = .005). Only the hybrid and 2-level ACP constructs had increased stability at C6-C7 in AR ROM compared with intact, with no difference for all test groups in LB ROM. Comparison between test constructs demonstrated no difference in C5-C7 and C6-C7 segmental stability in all planes of motion. However, at C5-C6 comparison between test constructs found the 2-level SAS had significantly less segmental stability compared to the hybrid (6.6° ± 3.2° vs 2.9° ± 2.0°, P = .025) and ACP (6.6° ± 3.2° vs 2.1° ± 1.4°, P = .004).

Conclusions:

Our study found the currently tested SAS device may be a reasonable option as part of a 2-level hybrid construct, when used below an adjacent 1-level ACP, but should be used with careful consideration as a 2-level SAS construct. Consequences of decreased segmental stability in FE are unknown; however, optimal immediate fixation stability is an important surgical principle to avoid loss of fixation, segmental kyphosis, interbody graft subsidence, and pseudarthrosis.
Preoperative Computed Tomography Myelography Parameters as Predictors of Outcome in Patients With Degenerative Cervical Myelopathy: Results of a Systematic Review
Authors: Waly Feras J. , Abduljabbar Fahad H. , Fortin Maryse , Nooh Anas , Weber Michael
Published: May 2017

Study Design:

Systematic review.

Objectives:

To determine the preoperative computed tomography (CT) myelogram imaging parameters in patients diagnosed with degenerative cervical myelopathy (DCM) that correlate with severity of DCM and predict postoperative patients’ functional outcome.

Methods:

An electronic database search was performed using Ovid Medline and Embase. CT myelogram studies investigating the correlation between imaging characteristics and DCM severity or postoperative outcomes were included. Two independent reviewers performed citation screening, selection, qualitative assessment, and data extraction using an objective and blinded protocol.

Results:

A total of 5 studies (402 patients) were included in this review and investigated the role of preoperative CT myelogram parameters in predicting the functional outcome after surgical treatment of DCM. All studies were retrospective cohort studies. CT myelogram characteristics included the transverse area of the spinal cord at maximum level of compression, spinal canal narrowing, number of blocks, spinal canal diameter, and flattening ratio. There is low evidence suggesting that patients with a preoperative transverse area of the spinal cord >30 mm2 at the level of maximum compression have better postoperative recovery and outcome. We found no studies investigating the correlation between preoperative CT myelogram parameters and DCM severity.

Conclusions:

Patients with greater transverse area of spinal cord at the level of maximum compression on the preoperative CT myelogram are more likely to have better neurological outcome after surgery. There is insufficient evidence to suggest that any of the other CT myelogram parameters investigated are predictors of postoperative outcomes in patients with DCM.
Posterolateral Fusion Versus Interbody Fusion for Degenerative Spondylolisthesis: Systematic Review and Meta-Analysis
Authors: Campbell Ryan C. , Mobbs Ralph J. , Lu Victor M. , Xu Joshua , Rao Prashanth J. , Phan Kevin
Published: May 2017

Study Design:

Systematic review and meta-analysis.

Objective:

Current surgical management of degenerative spondylolisthesis (DS) involves decompression of the spinal canal followed by fusion with or without interbody. The additional functional and operative benefits derived from interbody inclusion has yet to be thoroughly established with a number of recent studies producing conflicting results. Thus, we aim to compare the functional and operative outcomes after fusion against interbody fusion in the treatment of DS.

Methods:

This systematic review of the literature comparing posterolateral fusion (PLF) and posterior lumbar interbody fusion (PLIF) outcomes in the treatment of DS was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. Electronic searches of 6 databases yielded 386 articles from database inception to July 2016, which were screening against established criteria for inclusion into this study.

Results:

A total of 6 studies, satisfied criteria and reported outcomes for 721 patients. Fusion alone was performed in 458 (63.5%) patients and interbody fusion was performed in 263 (36.5%) patients. Functional outcomes Oswestry Disability Index ( P = .29) and visual analog scale ( P = .13) were not statistically different between the 2 approaches. Furthermore, there was no significant inferiority between fusion alone and with interbody in terms of the operative outcomes of blood loss ( P = .38), reoperation rate ( P = .66), hospital stay ( P = .96), complication rate ( P = .78), or fusion rate ( P = .15).

Conclusions:

There was no statistically significant difference in functional and operative outcomes following fusion alone versus with interbody. Additional subgroup analysis of intrinsic DS features in future large, prospective, randomized controlled trials will improve the validity of these findings.
The Predictive Value of Preoperative Health-Related Quality-of-Life Scores on Postoperative Patient-Reported Outcome Scores in Lumbar Spine Surgery
Authors: Hey Hwee Weng Dennis , Luo Nan , Chin Sze Yung , Lau Eugene Tze Chun , Wang Pei , Kumar Naresh , Lau Leok-Lim , Ruiz John Nathaniel , Thambiah Joseph Shanthakumar , Liu Ka-Po Gabriel , Wong Hee-Kit
Published: May 2017

Study Design:

A single-center, retrospective cohort study.

Objective:

To predict patient-reported outcomes (PROs) using preoperative health-related quality-of-life (HRQoL) scores by quantifying the correlation between them, so as to aid selection of surgical candidates and preoperative counselling.

Methods:

All patients who underwent single-level elective lumbar spine surgery over a 2-year period were divided into 3 diagnosis groups: spondylolisthesis, spinal stenosis, and disc herniation. Patient characteristics and health scores (Oswestry Low Back Pain and Disability Index [ODI], EQ-5D, and Short Form-36 version 2 [SF-36v2]) were collected at 6 and 24 months and compared between the 3 diagnosis groups. Multivariate modelling was performed to investigate the predictive value of each parameter, particularly preoperative ODI and EQ-5D, on postoperative ODI and EQ-5D scores for all the patients.

Results:

ODI and EQ-5D at 6 and 24 months improved significantly for all patients, especially in the disc herniation group, compared to the baseline. The magnitude of improvement in ODI and EQ-5D was predictable using preoperative ODI, EQ-5D, and SF-36v2 Mental Component Score. At 6 months, 1-point baseline ODI predicts for 0.7-point increase in changed ODI, and a 0.01-point increase in baseline EQ-5D predicts for 0.01-point decrease in changed EQ-5D score. At 24 months, 1-point baseline ODI predicts for 1-point increase in changed ODI, and a 0.01-point increase in baseline EQ-5D predicts for 0.009-point decrease in changed EQ-5D. A younger age is shown to be a positive predictor of ODI at 24 months.

Conclusions:

Poorer baseline health scores predict greater improvement in postoperative PROs at 6 and 24 months after the surgery. HRQoL scores can be used to decide on surgery and in preoperative counselling.