Cross-Sectional Imaging Evaluation of Congenital Temporal Bone Anomalies: What Each Radiologist Should Know.

Hearing loss in pediatric age group is associated with many congenital temporal bone disorders. Aberrant development of various ear structures leads into either conductive or sensorineural hearing loss. Knowledge of the embryology and anatomical details of various compartments of the ear help better understanding of such disorders. In general, abnormalities of external and middle ears result in conductive hearing loss. Whereas abnormalities of inner ear structures lead into sensorineural hearing loss. These abnormalities could occur as isolated or part of syndromes. Temporal bone disorders are a significant cause of morbidity and developmental delays in children. Imaging evaluation of children presented with hearing loss is paramount in early diagnosis and proper management planning. Our aim is to briefly discuss embryology and anatomy of the pediatric petrous temporal bones. The characteristic imaging features of commonly encountered congenital temporal bone disorders and their associated syndromes will be discussed.

Multi-modality imaging evaluation of the dorsal arachnoid web.

PURPOSE: Dorsal arachnoid web (DAW) is a rare intradural abnormality which is associated with progressive myelopathy. Our objective was to review multi-modality imaging techniques demonstrating the scalpel sign appearance in evaluation of DAW. METHODS: We retrospectively reviewed various imaging modalities of patients found to have DAW at our institution during January 2015 to February 2020. Five patients underwent surgical decompression with pathological correlation. The remaining patients were presumptively diagnosed based on the characteristic finding of scalpel sign. Clinical data were evaluated and correlated to imaging findings. All imaging modalities demonstrated the characteristic scalpel sign. RESULTS: Sixteen patients (10 females, and six males) with multi-imaging modalities were evaluated. Their mean age was 52 year (range 23-74 years). Fifteen patients underwent conventional spine MRI. Further high-resolution MR imaging techniques, e.g. 3D T2 myelographic sequence, were utilized with two patients. MRI spine CSF flow study was performed to evaluate the flow dynamic across the arachnoid web in one patient. Eight patients were evaluated with CT myelogram. Syrinx formation was discovered in seven (44%) patients; five (71%) of them underwent surgical resection and decompression. Two patients underwent successful catheter-directed fenestration of the web with clinical improvement. We found a statically significant positive correlation between the degree of cord displacement and compression with syrinx formation (r = 0.55 and 0.65 with p-value of 0.03 and 0.009, respectively). CONCLUSION: DAW has characteristic scalpel sign independent of imaging modality. Multi-modality imaging evaluation of DAW is helpful for evaluation and surgical planning.

A Prospective Observational Study of High-Dose Intrathecal Diamorphine in Laparoscopic Bariatric Surgery: a Single-Centre Experience.

BACKGROUND: Post-operative pain management following laparoscopic bariatric surgery can be challenging. There are concerns regarding the use of opioids. The rate of cardiorespiratory problems following neuraxial opioids is unclear. There is little published data on their use in bariatric surgery. This study aimed to assess technique feasibility, pain outcomes, patient acceptability, and the side effects and complications of a 'high-dose' (1.0 mg) intrathecal diamorphine technique for patients undergoing primary laparoscopic bariatric surgery. MATERIALS AND METHODS: Fifty patients were included. Eleven patients (22%) had a diagnosis of OSA. All patients had a spinal anaesthetic with 2.0 mL of 0.25% isobaric bupivacaine containing 1.0 mg diamorphine. General anaesthesia followed together with multi-modal analgesia and anti-emesis. Post-operative pain scores, complications, and side effects in the first 24 h post-operative period were documented. Patients were followed up 6 to 8 weeks after discharge. RESULTS: All patients had a working spinal anaesthetic with thirty-nine insertions (78%) on the first attempt. Pain scores were similar to previously published data where they were found to be superior to a non-spinal analgesic regime. The median 24 h post-operative oral morphine equivalent consumption was 5 mg. Eight patients (16%) required urinary catheterisation. Four patients (8%) complained of pruritus. Eighteen patients (36%) had post-operative nausea or vomiting. Thirty-three patients (66%) responded to the follow-up request. Thirty of the thirty-three patients (91%) stated they would have the spinal anaesthetic again. CONCLUSION: We have demonstrated that neuraxial blockade is a simple, practical, and feasible technique to adopt. Our case series demonstrated a high level of patient acceptability.

Transient flow-driven distortion of a nematic liquid crystal in channel flow with dissipative weak planar anchoring.

Motivated by the one-drop-filling (ODF) method for the industrial manufacturing of liquid crystal displays, we analyze the pressure-driven flow of a nematic in a channel with dissipative weak planar anchoring at the boundaries of the channel. We obtain quasisteady asymptotic solutions for the director angle and the velocity in the limit of small Leslie angle, in which case the key parameters are the Ericksen number and the anchoring strength parameter. In the limit of large Ericksen number, the solution for the director angle has narrow reorientational boundary layers and a narrow reorientational internal layer separated by two outer regions in which the director is aligned at the positive Leslie angle in the lower half of the channel and the negative Leslie angle in the upper half of the channel. On the other hand, in the limit of small Ericksen number, the solution for the director angle is dominated by splay elastic effects with viscous effects appearing at first order. As the Ericksen number varies, there is a continuous transition between these asymptotic behaviors, and in fact the two asymptotic solutions capture the behavior rather well for all values of the Ericksen number. The steady-state value of the director angle at the boundaries and the timescale of the evolution toward this steady-state value in the asymptotic limits of large and small Ericksen number are determined. In particular, using estimated parameter values for the ODF method, it is found that the boundary director rotation timescale is substantially shorter than the timescale of the ODF method, suggesting that there is sufficient time for significant transient flow-driven distortion of the nematic molecules at the substrates from their required orientation to occur.

Nuclear singlet relaxation by scalar relaxation of the second kind in the slow-fluctuation regime.

The singlet state of nuclear spin-1/2 pairs is protected against many common relaxation mechanisms. Singlet order, which is defined as the population difference between the nuclear singlet and triplet states, usually decays more slowly than the nuclear magnetization. Nevertheless, some decay mechanisms for nuclear singlet order persist. One such mechanism is called scalar relaxation of the second kind (SR2K) and involves the relaxation of additional nuclei ("third spins") which have scalar couplings to the spin-1/2 pair. This mechanism requires a difference between the couplings of at least one third spin with the two members of the spin-1/2 pair, and depends on the longitudinal relaxation time of the third spin. The SR2K mechanism of nuclear singlet relaxation has previously been examined in the case where the relaxation rate of the additional spins is on the time scale of the nuclear Larmor frequency. In this paper, we consider a different regime, in which the longitudinal relaxation of the third spins is on a similar time scale to the J-coupling between the members of the spin pair. This regime is often encountered when the spin-1/2 pair has scalar couplings to nearby deuterium nuclei. We show that the SR2K mechanism may be suppressed in this regime by applying a radiofrequency field which is resonant either with the members of the spin pair, or with the third spins. These phenomena are analyzed theoretically and by numerical simulations, and demonstrated experimentally on a diester of [13C2, 2H2]-labeled fumarate in solution.

Validation of the evaluation capacity in organizations questionnaire.

The purpose of this study was to test the construct validity of the Evaluation Capacity in Organizations Questionnaire (ECOQ). Conceptually, the ECOQ examines the role of evaluation in organizational development and, most notably in organizational learning. In this model, evaluation capacity building (ECB) initiatives are assumed to contribute to the development of a culture of systematic self-assessment and reflection, which, in turn, leads to increased organizational learning. Our sample consisted of internal evaluators within the federal, provincial or municipal government, not-for-profit organizations, private firms, and colleges or universities in Canada. Exploratory factor analysis (EFA) and latent path analysis (LPA) were conducted to better understand the underlying structural aspect of the organizational capacity to do and use evaluation construct as measured by the ECOQ. The results of our study indicate that the ECOQ effectively assesses an organization's capacity to do and use evaluation. Furthermore, evidence provided by the LPA statistical analysis suggests that an organization's capacity to learn is enhanced by the relationships among the various factors. Implications of using a validated model of an organization's capacity to do and use evaluations in both research and practice are discussed.

On the evaluation of social innovations and social enterprises: Recognizing and integrating two solitudes in the empirical knowledge base.

Social innovation (SI) is billed as a new way to address complex social problems. Interest in SI has intensified rapidly in the last decade, making it an important area of practice for evaluators, but a difficult one to navigate. Learning from developments in SI and evaluation approaches applied in SI contexts is challenging because of 'fuzzy' concepts and silos of activity and knowledge within SI communities. This study presents findings from a systematic review and integration of 41 empirical studies on evaluation in SI contexts. We identify two isolated conversations: one about 'social enterprises' (SEs) and the other about non-SE 'social innovations'. These conversations diverge in key areas, including engagement with evaluation scholarship, and in the reported purposes, approaches and use of evaluation. We identified striking differences with respect to degree of interest in collaborative approaches and facilitation of evaluation use. The findings speak to trends and debates in our field, for example how evaluation might reconcile divergent information needs in multilevel, cross-sectoral collaborations and respond to fluidity and change in innovative settings. Implications for practitioners and commissioners of evaluation include how evaluation is used in different contexts and the voice of evaluators (and the evaluation profession) in these conversations.

How Do Evaluators Differentiate Successful From Less-Than-Successful Experiences With Collaborative Approaches to Evaluation?

OBJECTIVES: In this exploratory study, we wanted to know how evaluators differentiate collaborative approaches to evaluation (CAE) perceived to be successful from those perceived to be less-than-successful. METHOD: In an online questionnaire survey, we obtained 320 responses from evaluators who practice CAE (i.e., evaluations on which program stakeholders coproduce evaluation knowledge). Respondents identified two specific CAE projects from their own experience-one they believed to be "highly successful" and another they considered "far less successful than [they] had hoped."-and offered their comments and reflections about them. They rated the respective evaluations on 5-point opinion and frequency scales about (i) antecedent stakeholder perspectives, (ii) the purposes and justifications for collaborative inquiry, and (iii) the form such inquiry takes. FINDINGS: The results showed that successful evaluations, relative to their less-than-successful counterparts, tended to reflect higher levels of agreement among stakeholders about the focal program; higher intentionality estimates of evaluation justification and espoused purposes; and wider ranges and deeper levels of stakeholder participation. No differences were found for control of technical decision-making, and evaluators tended to lead evaluation decision making, regardless of success condition. DISCUSSION: The results are discussed in terms of implications for ongoing research on CAE.

Peri-operative management of the obese surgical patient 2015: Association of Anaesthetists of Great Britain and Ireland Society for Obesity and Bariatric Anaesthesia.

Guidelines are presented for the organisational and clinical peri-operative management of anaesthesia and surgery for patients who are obese, along with a summary of the problems that obesity may cause peri-operatively. The advice presented is based on previously published advice, clinical studies and expert opinion.

Government and voluntary sector differences in organizational capacity to do and use evaluation.

Research on evaluation capacity is limited although a recent survey article on integrating evaluation into the organizational culture (Cousins, Goh, Clark, & Lee, 2004) revealed that interest in the topic is increasing. While knowledge about building the capacity to do evaluation has developed considerably, less is understood about building the organizational capacity to use evaluation. This article reports on the results of a pan-Canadian survey of evaluators working in organizations (internal evaluators or organization members with evaluation responsibility) conducted in 2007. Reliability across all constructs was high. Responses from government evaluators (N=160) were compared to responses from evaluators who work in the voluntary sector (N=89). The former were found to self-identify more highly as 'evaluators' (specialists) whereas the latter tended to identify as 'managers' (non-specialists). As a result, government evaluators had significantly higher self-reported levels of evaluation knowledge (both theory and practice); and they spent more time performing evaluation functions. However, irrespective of role, voluntary sector respondents rated their organizations more favorably than did their government sector counterparts with respect to the antecedents or conditions supporting evaluation capacity, and the capacity to use evaluation. Results are discussed in terms of their implications for evaluation practice and ongoing research.

Making program evaluation activities family-centered: a qualitative study.

PURPOSE: This study explored ways in which program evaluation activities in pediatric rehabilitation settings can become congruent with family-centered service (FCS) philosophy. METHODS: Two Canadian pediatric rehabilitation centers participated in this study, which included focus groups with staff members and interviews with parents. RESULTS: Participants identified seven ways in which program evaluation practices could be made congruent with FCS. Suggestions included: (a) the inclusion of a diverse group of program recipients, (b) the use of processes that facilitate family involvement, (c) the recruitment of family champions, (d) the involvement of families in program development, (e) the establishment of evaluations that are relevant to families (f) the development of center-wide statements about family involvement in evaluation and (g) the compensation of families for their active participation in evaluation. CONCLUSION: For program evaluation practices to be useful and relevant, they should be improved and made consistent with FCS philosophy. Those evaluating pediatric rehabilitation programs need to use approaches and activities that respect the needs, characteristics, cultures and diversity of the program recipients. Such actions will help to improve the quality of care provided, the nature of program evaluation activities, as well as the overall level of FCS in pediatric rehabilitation settings.

A survey of program evaluation practices in family-centered pediatric rehabilitation settings.

Program evaluation is becoming increasingly important in pediatric rehabilitation settings that adhere to the family-centered service (FCS) philosophy. However, researchers know little about the specific evaluation activities occurring in these settings or the extent to which evaluators/service providers uphold FCS in their program evaluation activities. Through a questionnaire survey, this study aimed to document evaluators/service providers' perceptions of the level of program evaluation occurring in their Canadian pediatric rehabilitation centers. It also investigated the extent to which evaluators/service providers perceive program evaluation practices at their centers to be consistent with the FCS context of Canadian pediatric rehabilitation settings. The findings suggested that the amount of evaluation activities occurring within the respondents' centers is variable; that the majority of individuals working in program evaluation do not have formal training in it; and that the respondents' centers have limited resources for evaluation. The study also showed that staff members believe their centers' evaluation activities are somewhat consistent with FCS philosophy, but that improvements are needed.

When does a conceptual framework become a theory? Reflections from an accidental theorist.

In this short paper I reflect on the application of a program logic modeling approach to visualizing evaluation theory as it relates to practical participatory evaluation (PPE). The work of Hansen, Alkin and associates presented in this volume is well-thought out, carefully done, rigorous, and important. I found that their application of the approach resonated well with my understanding of PPE with a few notable exceptions. Specifically, the essence of the partnership aspect of the approach was underemphasized as was stakeholders' role in augmenting the credibility of evaluation findings and PPEs contribution to conceptual use. I then reminisce about the development and evolution of the participatory evaluation framework that we have been working with for so many years. I raise the point that we think of it as a theoretical framework to bound inquiry, not as an evaluation theory per se, which raises an interesting question: when does a theoretical framework become a theory?

Motion of the cerebellar tonsils in the foramen magnum during the cardiac cycle.

Tonsil motion was measured with cine MR imaging in patients clinically suspected of having Chiari I malformation. Cardiac-gated sagittal 2D fast imaging employing steady-state acquisition (2D FIESTA) was performed in 11 patients with a Chiari I malformation and in 6 subjects without tonsil ectopia. Tonsil motion was measured through the cardiac cycle with a pixel-shift program designed for that purpose. Tonsil displacements in patients with Chiari I and those with normal cerebellar tonsils were compared. In patients with Chiari I and subjects with normal cerebellar tonsils, 2D FIESTA showed small-amplitude tonsil movement in cephalad and caudad directions during the cardiac cycle. The average total magnitude of motion was 0.43 mm in subjects with normal tonsils (controls) and 0.57 mm in patients with Chiari malformations, 33% greater than that in controls. Tonsil motion was 0.61 mm in the patients with syringomyelia and 0.50 mm in those without it (22% difference).

Iodocyclization reactions for the desymmetrization of cyclohexa-1,4-dienes.

Fifteen examples are presented showing that various modes of cyclization (5-endo, 5-exo, 6-endo, 6-exo, and 7-endo) can be used for the desymmetrization of cyclohexa-1,4-dienes. All take place with complete diastereocontrol and good yield.