Multilevel Case Research Articles

Participatory multi-objective optimization for planning dense and green cities

The consideration of urban ecosystem services becomes increasingly important when planning compact cities. We implement a multi-objective optimization approach to support decision-makers in their efforts to develop green and dense cities. Embedded in a participatory process, the applied genetic algorithm allows us to assess spatial tradeoffs between urban ecosystem services and compactness. The optimization model is embedded in a decision support system for interactive analysis and communication of the results, facilitating the engagement of planners to support sustainable development. We illustrate the process in a multi-level case study in Singapore, a tropical city state aiming to pursue its distinct greening strategy. The whole process, from the problem definition to the obtained solution set, is evaluated using a feedback loop with stakeholders. Using this approach, we identify robust and best-suited urban development locations as well as temporal prioritization schemes evolving around future public transportation nodes.

Governance Challenges at the Interface of Food Security and Biodiversity Conservation: A Multi-Level Case Study from Ethiopia

Ensuring food security while also protecting biodiversity requires a governance system that can address intra- and intersectoral complexity. In this paper, we sought to explore the governance challenges surrounding food security and biodiversity conservation through an empirical study in Jimma zone, southwestern Ethiopia. We used bottom-up snowball sampling to identify stakeholders and then held semi-structured interviews with 177 stakeholders across multiple levels of governance. We also conducted 24 focus group discussions with local people. Data were transcribed and thematically analyzed for its contents. Challenges in the structure of institutions and policy incoherence were the key challenges identified for the governance of food security and biodiversity conservation. The challenges around institutional structure included incompatibilities of the nature of governing institutions with the complexity inherent within and between the two sectors examined. Incoherences in policy goals, instruments, and contradictions of policy output relative to the actual problems of food security and biodiversity further hampered effective governance of food security and biodiversity conservation. Notably, many of the challenges that influenced an individual sector also posed a challenge for the integrated governance of food security and biodiversity conservation, often in a more pronounced way. Based on our findings, we argue that governance in our case study area requires a more integrated and collaborative approach that pays attention to institutional interplay in order to ensure institutional fit and consistency across policy goals.

A closed-form solution to multi-level image thresholding

This paper proposes an analytical formulation relying on the least square error. Similar results were also found for the cross correlation, within-class, and between-class variance. At first, a continuous distribution is hypothesized (for derivation purposes only) to produced a modified form of the well-known OTSU method. This hypothesis is “identical” to Otsu in terms of output performance and the need for an exhaustive search. However, apart from being derived from the continuous form, the proposed scheme requires less computational power. It turns out that the optimum threshold equals the average of the adjacent regions’ means. For some images, the scheme can result in multi-level thresholdeds. A direct form was then suggested to obtain a non-exhaustive solution. The idea is simply to approximate the non-continuous error function (used by the least square formulation and OTSU) with a forth order polynomial defined in the normalized gray intensity range [0,1]. The optimum threshold can then be found as a function of the roots of a second order polynomial whose coefficients are the solution of a 2x2 linear system. The performance of the proposed non-exhaustive solution is slightly inferior to OTSU in general, however; some images produced improved performance. Nevertheless, The proposed scheme can be easily generalized to the multi-level case without the need for an exhaustive search. For n+1 levels (i.e. n thresholds), the output is obtained by solving an nxn linear system followed by finding the roots of a n-order polynomial. The computational cost is clearly superior to the exhaustive search. In addition, as validated with some images, the performance is encouraging. Extension to the general clustering case is highly envolved with the exception of the two-level case (for any dimension) that has been successfully derived in this work.

Multilevel Spectral Coarsening for Graph Laplacian Problems with Application to Reservoir Simulation

We extend previously developed two-level coarsening procedures for graph Laplacian problems written in a mixed saddle point form to the fully recursive multilevel case. The resulting hierarchy of d...

Hospital managers’ perspectives with implementing quality improvement measures and a new regulatory framework: a qualitative case study

A new regulatory framework to support local quality and safety efforts in hospitals was introduced to the Norwegian healthcare system in 2017. This study aimed to investigate hospital managers’ perspectives...

Thoracic myeloradiculopathy due to multilevel ossification of ligamentum flavum

Ossification of ligamentum flavum (OLF) is calcification of the ligamentum flavum, which might narrow the spinal canal and causes myeloradiculopathy. This condition mainly affects the lower thoracal segment. Published reports on OLF are mostly from East Asia. There was only one Indonesian OLF case that had been published. The majority of OLF involves a single level only. This is the first Indonesian case-report on multilevel OLF. Through this case report, we aim to describe the natural history of the patient and our treatment strategy in managing the multilevel OLF case.
 Delayed time to surgery is the key contributory factor in unfavorable surgical outcome in thoracic OLF. Choosing an appropriate surgical procedure is important. The neurological symptoms of the patient may not improve or worsen when an inadequate surgical procedure is used.

Long Term Clinical Outcomes Of Multi-Level Spinal SBRT For Vertebral Metastases

Currently, sSBRT is commonly limited to solitary, 2 contiguous or 3 non-contiguous vertebral levels because of concerns regarding setup accuracy, efficacy, and toxicity when 2-3 non-contiguous levels are treated. There is, however, a paucity of data regarding the clinical outcomes of multilevel sSBRT. LC and toxicity are particularly important endpoints to ensure that standard clinical target volume (CTV), planning target volume (PTV), and planning organ-at-risk volume (PRV) expansions are appropriate in the multilevel setting. We sought to compare efficacy and toxicities of single- vs multilevel (≥2-5) treatment in a cohort of patients with malignant spinal tumors. Radioresistant histologies, Bilsky grade 0 to 1 epidural spinal cord compression,5 and a life expectancy >6 mo. are treated by SBRT. Single level and Multi-level spinal SBRT are defined as sSBRT delivered to a malignant lesion spanning single and ≥2 contiguous vertebral levels. All patients underwent treatment rigid immobilization for C1-D4 targets / body fix immobilization for D5 and below targets. For intact cases, GTVs were delineated using the registered T1-weighted precontrast and postcontrast MRI sequences, with reference to additional diagnostic studies (PET and perfusion MRI). CTVs were expanded 2mm circumferentially to create PTVs, with the goal of≥95% PTV coverage with ≥100% of the prescription dose. For cord delineation done on either CT myelography / T2-weighted MRI fused to the planning CT with 1-mm cord PRV. The same PTV and PRV expansions were used regardless of surgical status or number of treated vertebral levels. All patients underwent multi-isocenter VMAT planning using dual arcs and treatment delivered on C-Arm Linac using 6 DOF robotics with pretreatment, Intrafraction and posttreatment imaging. We analyzed consecutive cases of sSBRT treated from 2013 to 2017. Time-to event outcomes for single-level and multilevel cases were compared using mixed effect Cox models and differences in toxicity rates were evaluated using linear mixed effect models. All models incorporate a patient-level random intercept to account for any within patient. There were 101 single-level and 84 multilevel sSBRT cases (2-5 continuous vertebral levels). One-year LC was 95% vs 85%, respectively. After adjusting for baseline covariates, dose delivered, and accounting for within-patient correlation, there was no significant difference in time to local failure (hazard ratio, HR 1.79 [0.59-5.4]; P = .30). Pain improved in 83.5% of the 139 initially symptomatic tumors. There were no significant differences in grade 2+ acute or late toxicities between single-level and multilevel sSBRT Multilevel sSBRT provides high rates of LC, similar to single-level treatment, without need for larger planning volume margins. Efforts to improve prognostication and case selection for multilevel sSBRT are warranted to ensure that the benefits of improved LC over palliative radiation are justified.

On Multigrid Methods for Solving Two-Dimensional Boundary-Value Problems

Various methods for constructing algebraic multigrid type methods for solving multidimensional boundary-value problems are considered. Two-level iterative algorithms in Krylov subspaces based on approximating the Schur complement obtained by eliminating the edge nodes of the coarse grid are described on the example of two-dimensional rectangular grids. Some aspects of extending the methods proposed to the multilevel case, to nested triangular grids, and also to three-dimensional grids are discussed. A comparison with the classical multigrid methods based on using smoothing, restriction (aggregation), coarse-grid correction, and prolongation is provided. The efficiency of the algorithms suggested is demonstrated by numerical results for some model problems.

Enacting quality improvement in ten European hospitals: a dualities approach

BackgroundHospitals undertake numerous initiatives searching to improve the quality of care they provide, but these efforts are often disappointing. Current models guiding improvement tend to undervalue the tensional nature of hospitals. Applying a dualities approach that is sensitive to tensions inherent to hospitals’ quest for improved quality, this article aims to identify which organizational dualities managers should particularly pay attention to.MethodsA set of cross-national, multi-level case studies was conducted involving 383 semi-structured interviews and 803 h of non-participant observation of key meetings and shadowing of staff in ten purposively sampled hospitals in five European countries (England, the Netherlands, Portugal, Sweden, and Norway).ResultsSix dualities that describe the quest for improved quality, each embracing a seemingly contradictory feature were identified: plural consensus, distributed connectedness, orchestrated emergence, formalized fluidity, patient coreness, and cautious generativeness.ConclusionsWe advocate for a move from the usual sequential and project-based and systemic thinking about quality improvement to the development of meta-capabilities to balance the simultaneous operation of opposing ideas or concepts. Doing so will help hospital managers to deal with major challenges of change inherent to quality improvement initiatives.

A Case of Thoracic Spondylosis Deformans and Multilevel Instrumented Spinal Fusion in an 84-Year-Old Male

Spondylosis deformans is a type of spinal claw osteophytosis which can be found on the anterolateral vertebral bodies of any region, and which consists of protrusions of intervertebral disc tissue covered by a bony shell. We report here a case of thoracic spondylosis deformans and multilevel instrumented fusion found during routine dissection of a cadaver. Theories of the etiology of this condition are reviewed in general, and with respect to this specific case and the potential interaction of the presenting comorbidities. The clinical implications of these osteophytes, including musculoskeletal and visceral sequelae, are also discussed.

Implications of self-managing teams for the HRM function

PurposeOrganisations increasingly implement self-managing teams (SMTs) to empower their employees. By drawing from the HRM process model and multilevel thinking, this paper explores how the HRM function changes in terms of actors and activities when introducing SMTs.Design/methodology/approachAn in-depth, multilevel case study was conducted at a large healthcare organisation in The Netherlands, making use of 70 interviews, document analysis and observations.FindingsThe findings show that SMTs transform the HRM function by changing the responsibilities of teams, HRM professionals and line managers in the implementation of HRM activities. The analysis shows that many HRM responsibilities are devolved to SMTs, which are supported by the HRM department.Research limitations/implicationsThese changes in the HRM function influence the HRM implementation process and provide all actors with new roles and activities. Based on these findings, this paper presents an inductive model of HRM implementation.Practical implicationsThe findings help HRM practitioners to transform the HRM function when deciding to introduce SMTs.Originality/valueThis article is one of the first that empirically explores how the HRM function changes as a consequence of introducing SMTs. This is important because more and more organisations are adopting SMTs, while knowledge about the role of HRM is lacking.

Application of Zero-profile Spacer in the Treatment of Three-level Cervical Spondylotic Myelopathy: 5-year Follow-up Results.

A retrospective study. To assess the long-term results of zero-profile spacer for 3-level anterior cervical discectomy and fusion (ACDF). Although widely used, there are still controversies about the long-term results of zero-profile spacer, especially in multilevel cases. Cases received 3-level ACDF for cervical spondylotic myelopathy (CSM) using either zero-profile spacer (n = 27) (ZP Group), or plate and cages (n = 34) (PC Group), and with 5-year follow-up were reviewed. Neurological function and life quality were assessed by modified Japanese Orthopaedic Association (mJOA) score, Neck Disability Index (NDI), and Short-Form 36 (SF-36) score. Disc height, cervical lordosis, fusion rate, and surgical complications were observed. Neurological recovery and life quality improvement were similar in both groups. Disc height and cervical lordosis (C2-7 Cobb angle) were well restored after operations, but lost in both groups during follow-up. Loss of correction (LOC) in disc height was larger in ZP Group (11.38% vs 5.71%, P < 0.05) at 5-year follow-up. LOC of cervical lordosis in ZP group constantly grew from 11.28% to 48.13% during 5-year follow-up, significantly higher than that in the PC group (from 7.43% to 14.01%) (P < 0.05). The rate of postoperative dysphagia was no statistical difference between the two groups, and symptoms were all disappeared within 1 year. There were 10 levels of adjacent segment degeneration (1 in ZP Group, and 10 in PC Group, P = 0.02). Cage subsidence (11 of 81 levels, 13.58%) and screw migration (2 of 81 levels, 2.47%) were only observed in the ZP Group. The migrated screws in one case were surgically removed. Fusion was achieved in all cases. In long-term follow-up of 3-level ACDF for CSM, zero-profile spacer has the similar clinical results, but loss of correction of disc height and cervical alignment were significantly higher, compared with anterior plate and cages. 3.

Infrastructuring the Circular Economy

The circular economy (CE), and its focus on the cycling and regeneration of resources, necessitates both a reconfiguration of existing infrastructures and the creation of new infrastructures to facilitate these flows. In urban settings, CE is being realized at multiple levels, from within individual organizations to across peri-urban landscapes. While most attention in CE research and practice focuses on organizations, the scale and impact of many such efforts are limited because they fail to account for the diversity of resources, needs, and power structures across cities, consequently missing opportunities for adopting a more effective and inclusive CE. Reconfiguring hard infrastructures is necessary for material resource cycling, but intervening in soft infrastructures is also needed to enable more inclusive decision-making processes to activate these flows. Utilizing participatory action research methods at the intersection of industrial ecology and design, we developed a new framework and a model for considering and allocating the variety of resources that organizations utilize when creating value for themselves, society, and the planet. We use design prototyping methods to synthesize distributed knowledge and co-create hard and soft infrastructures in a multi-level case study focused on urban food producers and farmers markets from the City of Chicago. We discuss generalized lessons for “infrastructuring” the circular economy to bridge niche-level successes with larger system-level changes in cities.

Effects of gender mainstreaming efforts on rural transport institutions in Kenya

This paper reports on an investigation into the effects of gender mainstreaming efforts on the institutions that deliver and support rural transport infrastructure and services in Kenya. It comes at a time when the nation is implementing robust policies, supported by enabling legislative and institutional frameworks for gender mainstreaming as required by the Constitution of Kenya 2010. A multi-level case study was conducted at national and county levels where many institutions were surveyed. Qualitative and quantitative data were collected, covering gender analysis in staffing, decision-making and procurement for a sample of rural transport institutions. Results show that gender mainstreaming efforts have transformed rural transport institutions towards gender-responsive staffing, human-resource practices, budgeting, procurement and implementation of transport-related works. However, achieving the constitutional two-thirds affirmative action policy in staffing remains a challenge, more so in technical and decision-making bodies. The study found that the meaning and purpose of gender mainstreaming is not sufficiently understood by the majority of transport sector institutions. Additionally, gender-disaggregated data are neither readily available nor applied to rural transport programming and implementation. A change of strategy and long-term progressive efforts are required to realise gender equity in rural transport institutions in Kenya and beyond.

Bigflow: A General Optimization Layer for Distributed Computing Frameworks

As data volumes grow rapidly, distributed computations are widely employed in data-centers to provide cheap and efficient methods to process large-scale parallel datasets. Various computation models have been proposed to improve the abstraction of distributed datasets and hide the details of parallelism. However, most of them follow the single-layer partitioning method, which limits developers to express a multi-level partitioning operation succinctly. To overcome the problem, we present the NDD (Nested Distributed Dataset) data model. It is a more compact and expressive extension of Spark RDD (Resilient Distributed Dataset), in order to remove the burden on developers to manually write the logic for multi-level partitioning cases. Base on the NDD model, we develop an open-source framework called Bigflow, which serves as an optimization layer over computation engines from most widely used processing frameworks. With the help of Bigflow, some advanced optimization techniques, which may only be applied by experienced programmers manually, are enabled automatically in a distributed data processing job. Currently, Bigflow is processing about 3 PB data volumes daily in the data-centers of Baidu. According to customer experience, it can significantly save code length and improve performance over the intuitive programming style.

Local Control and Toxicity of Multilevel Spine Stereotactic Body Radiotherapy.

Spine stereotactic body radiotherapy (sSBRT) is commonly limited to 1 or 2 vertebral levels given a paucity of efficacy and toxicity data when more than 2 levels are treated. To prove our hypothesis that multilevel sSBRT could provide similar rates of local control (LC) (primary endpoint) and toxicity as single-level treatment using the same clinical target, planning target, and planning organ-at-risk volumes. We analyzed consecutive cases of sSBRT treated from 2013 to 2017. Time-to-event outcomes for single-level and multilevel cases were compared using mixed effect Cox models and differences in toxicity rates were evaluated using linear mixed effect models. All models incorporate a patient-level random intercept to account for any within-patient correlation across cases. There were 101 single-level and 84 multilevel sSBRT cases (2-7 continuous vertebral levels). One-year LC was 95% vs 85%, respectively. After adjusting for baseline covariates, dose delivered, and accounting for within-patient correlation, there was no significant difference in time to local failure (hazard ratio, HR 1.79 [0.59-5.4]; P=.30). Pain improved in 83.5% of the 139 initially symptomatic tumors. There were no significant differences in grade 2+acute or late toxicities between single-level and multilevel sSBRT. With rigorous patient immobilization, quality assurance, and image guidance, multilevel sSBRT provides high rates of LC, similar to single-level treatment, without need for larger planning volume margins. Efforts to improve prognostication and case selection for multilevel sSBRT are warranted to ensure that the benefits of improved LC over palliative radiation are justified.

Two-level uncapacitated lot-sizing problem considering the financing cost of working capital requirement

During financial crisis, companies constantly need free cash flows to efficiently react to any uncertainty, thus ensuring solvency. Working capital requirement (WCR) has been recognized as a key factor for releasing tied up cash in companies. However, in literatures related to lot-sizing problem, WCR has only been studied in the single-level supply chain context. In this paper, we initially adopt WCR model for a multi-level case. A two-level (supplier-customer) model is established on the basis of the classic multi-level lot-sizing model integrated with WCR financing cost. To tackle this problem, we propose sequential and centralized approaches to solve the two-level case with a serial chain structure. The ZIO (Zero Inventory Ordering) property is further confirmed valid in both cases. This property allows us to establish a dynamic programming-based algorithm, which solves the problem in O(T4). Finally, numerical tests show differences in optimal plans obtained by both approaches and the influence of varying delays in payment on the WCR of both actors.

Anterior cervical corpectomy

Anterior cervical corpectomy and fusion serves as a powerful surgical technique in the treatment of complex cervical spine pathology including multilevel cervical myelopathy, cervical trauma, cervical infection, and neoplastic disease. Determining the optimal approach for treatment involves assessing the need for spinal cord decompression and restoration of structural stability. A number of factors or measurements have been described to assist in determining the best treatment approach for a given pathology. Similar anterior cervical techniques may be utilized whether performing a single or multilevel corpectomy although supplemental posterior instrumentation and fusion should be considered for multilevel corpectomy cases due to increased failure rates with anterior cervical plating alone. Attention to detail and an appropriate degree of vigilance can help surgeons minimize risk, recognize potential complications, and deliver optimal patient care in these often complex and challenging patients.

Feasibility and Outcomes of Tubular Decompression in Extreme Stenosis.

Retrospective cohort study. To report the feasibility, nuances, technical tips as well as outcomes of managing single-level grade D (extreme stenosis) and to compare the outcomes with nonextreme stenosis using the tubular retractor system. Minimally invasive decompression in extreme stenosis is a challenge due to technical difficulty, feasibility of adequate decompression, and a steep learning curve. Consecutive patients from January 2007 to January 2017 presenting with neurogenic claudication secondary to single-level spinal stenosis operated using tubular retractors were included in the study. The patients were divided into two groups; extreme-stenosis and nonextreme stenosis. The outcomes of surgery were evaluated and compared using visual analogue score (VAS) for leg and back pain, Oswestry disability index (ODI), and MacNab's criteria. A total of 325 patients (out of 446 patients after excluding the multilevel cases) fulfilled the inclusion criteria. One hundred forty patients were cases of extreme stenosis and 185 were nonextreme stenosis. The mean VAS for back and leg pain for extreme stenosis improved from 3.23 ± 1.30 to 2.15 ± 0.91 and 7.33 ± 0.78 to 1.66 ± 1.03 respectively as compared with nonextreme stenosis where the mean VAS for back and leg pain improved from 3.01 ± 1.15 to 1.86 ± 1.10 and 6.57 ± 1.00 to 1.54 ± 1.12 respectively. The mean ODI changed from 66.47 ± 7.53 to 19.95 ± 2.90 in extreme stenosis as compared with nonextreme stenosis where mean ODI changed from 59.05 ± 5.08 to 19.88 ± 2.67. As per MacNab's criteria 102 (of 120 patients) and 139 (of 157 patients) reported excellent and good outcomes in extreme and nonextreme stenosis respectively. Tubular decompression is feasible in patients with extreme-stenosis with no difference in the outcomes as well as complication rates when compared with a cohort of nonextreme stenosis. 3.

Talent designation in practice: an equation of high potential, performance and mobility

Effective identification of talent is a central element of talent management. Talk of talent often involves two distinct, yet interrelated dimensions: performance and potential. The talent management literature has however provided limited consideration both conceptually and empirically concerning the delimitation between these two dimensions. This paper looks to address this by examining how the talent construct is operationalised in practice. It considers two key research questions; what indicators of performance and potential are applied by key organisational stakeholders in discerning what talent is? What factors impact talent designation? We adopt a multilevel case study design encompassing 73 interviews with senior organisational leaders in three multinational hotel corporations. Our findings demonstrate that the dimensions of high performance and high potential were commonly spoken about when referring to talent. However, there was a substantial lack of clarity around potential with a conflation between it and performance common. Moreover, mobility emerged as a critical contextual factor in being labelled as talent or not. The paper contributes to talent management scholarship by providing a more nuanced approach in understanding how talent is enacted in practice in an underexplored empirical context.