A stochastic programming approach to resource-constrained assignment problems

We address the resource-constrained generalizations of the assignment problem with uncertain resource capacities, where the resource capacities have an unknown distribution that can be sampled. We propose three stochastic programming-based formulations that can be used to solve this problem, and provide exact and approximate solution techniques for the resulting models. We also present numerical results for a large set of numerical problems. The results indicate that the solutions obtained using the stochastic programming approaches perform significantly better than those obtained using expected values of capacities in a deterministic solution strategy. In addition, stochastic-programming-based approximations are computationally as efficient as deterministic techniques

Diffusion tensor imaging of cervical spinal cord: A quantitative diagnostic tool in cervical spondylotic myelopathy

Background: Diffusion tensor imaging (DTI) is a novel magnetic resonance imaging (MRI) technique potentially able to evaluate the microscopic structural organization of white matter fibers. Aim: This study aimed to compare fractional anisotropy (FA) and apparent diffusion coefficient (ADC) values obtained by DTI in stenotic versus nonstenotic cervical spinal segments of patients with clinical and neurological evidence of cervical spondylotic myelopathy (CSM). Materials and Methods: This prospective study included 21 patients with CSM but without T2 changes on conventional MRI. Diffusion tensor (DT) images from the stenotic and nonstenotic segments of the subjects were obtained. FA and ADC values were estimated and compared with stenotic versus nonstenotic segments. Statistical Analysis: Paired t-test was used [Statistical Package for the Social Sciences (SPSS) 12.0]. Results: In the most stenotic segments, the mean FA value was significantly lower (0.4228 ± 0.1090 vs 0.6884 ± 0.0075, P < 0.001) and the mean ADC value was significantly higher (1.312 ± 0.2405 vs 0.9183 ± 0.1477, P < 0.001) when compared to nonstenotic segments. In addition, there was a negative correlation between FA and ADC values (r = 0.63, P = 0.002). Conclusions: DTI of the cervical spine seems to be a promising novel imaging modality in patients with CSM. Advances in Knowledge: DTI may offer increased diagnostic sensitivity as compared to standard MRI and enables earlier detection of the disease

Be Suggested According to Age and Sex?

Purpose: The aims of this study were to assess the prevalence of nocturia and nocturnal polyuria (NP) and to define new cutoff values according to age and sex for both conditions.Methods: Data from a population-based prevalence survey conducted among a random sample of 2,128 adults were analyzed in this study. Participants were requested to fill out a questionnaire including the International Continence Society (ICS) definitions of lower urinary tract symptoms and the International Consultation on Incontinence Questionnaire - Short Form. Additionally, a 1-day bladder diary was given to each individual. The participants were divided into 5 age groups. The prevalence of nocturia was calculated based on definitions of nocturia as >= 1 voiding episodes, >= 2 episodes, and >= 3 episodes. NP was evaluated according to the ICS definition. The mean +/- standard errors and 95th percentile values were calculated in each group as new cutoff values for NP.Results: The prevalence of nocturia was estimated as 28.4%, 17.6%, and 8.9% for >= 1, >= 2, and >= 3 voiding episodes each night, respectively. When nocturia was defined as 2 or more voiding episodes at night, the prevalence decreased significantly. The mean NP index was 29.4% +/- 15.0% in men and 23.1% +/- 11.8% in women. For the age groups of = 60 years, the new cutoff values for the diagnosis of NP were calculated as 48%, 69%, and 59% for men and 41%, 50%, and 42% for women, respectively.Conclusions: We found that the definition of nocturia was still controversial and that waking up once for voiding might be within the normal spectrum of behavior. The definition of NP should be modified, and new cutoff values should be defined using the data presented in our study and in other forthcoming studies

Street Drug Use among Emergency Patients in a Public Hospital in Turkey

Background: Country-specific numbers of street drug (SD) users are well documented. However, little data exists regarding these patients’ clinical presentations and outcomes in the emergency department (ED). Therefore,management of these patients in the emergency setting is still a subject of debate. Objectives: The aim of this study is to determine the symptoms and signs of SD users presenting to the ED, and to report the substances, treatments, and outcomes. Materials and Methods: In this single-center study, symptoms, clinical findings, diagnoses, and outcomes of patients who reported to have used SDs or were diagnosed as SD users were investigated within a 1-year study period. Chi-square and Mann-Whitney U tests were performed to compare independent variables. Results: Mean age of the 425 study patients was 25 ± 9 years (range: 12-64 years), and 6.1% (n = 26) of the patients were females. SDs used before presentation to the ED were mostly synthetic cannabinoids and “ecstasy.” Overall prevalence of SD user admissions in ED was 0.24%. The most common presenting complaint was weakness/faintness in 21.1% (n = 90). Depressed level of consciousness was the most common physical sign (33.3%, n = 142). Incidences of altered mental status were significantly higher among ecstasy and/or bonsai users (n = 14, 27.5%; P = 0.027 and n = 46, 64.8%; P &lt; 0.001, respectively), compared to other SD users. While 23.1% (n = 98) of the SD users did not warrant any medical intervention, 6.6% of the users (n = 28) underwent advanced life support. Conclusions: Selfreported SD users were mostly young males who were treated symptomatically and discharged. Almost one-third-mostly ecstasy and bonsai users-had depressed level of consciousness and required resuscitation.Keywords: Adverse drug effect, cannabis, ecstasy, emergency medicine, street drug use

An ioMRI-assisted case of cervical intramedullary diffuse glioma resection

Zafer Orkun Toktas,1,2 Baran Yilmaz,1 Murat Şakir Ekşi,1,3 Lei Wang,2,4 Akin Akakin,1 Yasin Yener,5 Murat Konakcı,6 Emre Ayan,7 Turker Kılıc,1 Deniz Konya,1,2 Yang D Teng2,4 1Department of Neurosurgery, Bah&ccedil;eşehir University Medical Faculty, Istanbul, Turkey; 2Departments of Physical Medicine and Rehabilitation and Neurosurgery, Harvard Medical School, Boston, MA, USA; 3Department of Orthopedic Surgery, University of California at San Francisco, San Francisco, CA, USA; 4Division of Spinal Cord Injury Research, Veterans Affairs Healthcare System, Boston, MA, USA; 5Department of Anesthesiology, G&ouml;ztepe Medikal Park Hospital, Istanbul, Turkey; 6Department of Anesthesiology, Bah&ccedil;eşehir University Medical Faculty, Istanbul, Turkey; 7Department of Radiology, G&ouml;ztepe Medical Park, Istanbul, Turkey Purpose: To date, application of intraoperative magnetic resonance imaging (ioMRI) to enhance surgical quality for spinal intramedullary neoplastic lesions has been rarely reported. Moreover, in developing countries or regions, ioMRI accessibility remains very limited. This report describes a technology design of high-field ioMRI accessible for multioperation rooms via a case presentation of an imaging-assisted surgical excision of human cervical spinal cord diffuse glioma.Patient and methods: The patient was a 44-year-old woman with symptomatic and progressive C2&ndash;5 intramedullary diffuse glioma (IDG). Our ioMRI system was designed and arranged with accessibility to multiple operation rooms, which was used to assure more complete spinal cord or brain tumor removal. The intraoperational diagnostic aspects and the system setup technical details are presented for future applications of the system in hospitals where a designated ioMRI suite is not available.Results: After a conventionally defined complete removal of C2&ndash;C5 IDG using a well-established surgical approach, ioMRI examination was able to detect residual tumor tissues that were indistinguishable under the surgical microscope. The IDG clusters were subsequently excised. The operation regimen resulted in a gross total elimination of the tumor, which enabled the patient to show very satisfactory postsurgery recovery and prognosis.Conclusion: ioMRI-assisted surgical removal of cervical spinal cord diffuse glioma should be systematically developed and applied to enhance therapeutic efficacy. The reported logistic flow of operating room tasks and imaging technical management are innovative for performing the tumor removal procedures in hospitals where designated ioMRI surgical suites do not exist. Critically, we emphasize implementation of stringent quality control measures for patient transportation safety and contamination prevention in establishing and maintaining such a system. Keywords: intraoperative imaging, spine, spinal cord, glioma, residual tumor, decompressio