Sampling and Reconstruction of Graph Signals via Weak Submodularity and Semidefinite Relaxation

We study the problem of sampling a bandlimited graph signal in the presence of noise, where the objective is to select a node subset of prescribed cardinality that minimizes the signal reconstruction mean squared error (MSE). To that end, we formulate the task at hand as the minimization of MSE subject to binary constraints, and approximate the resulting NP-hard problem via semidefinite programming (SDP) relaxation. Moreover, we provide an alternative formulation based on maximizing a monotone weak submodular function and propose a randomized-greedy algorithm to find a sub-optimal subset. We then derive a worst-case performance guarantee on the MSE returned by the randomized greedy algorithm for general non-stationary graph signals. The efficacy of the proposed methods is illustrated through numerical simulations on synthetic and real-world graphs. Notably, the randomized greedy algorithm yields an order-of-magnitude speedup over state-of-the-art greedy sampling schemes, while incurring only a marginal MSE performance loss

Investigating the level of moral distress and its related factors among nurses in mazandaran burn center

Background and purpose: Moral distress is a common phenomenon in nursing professional and burn nurses are constantly faced with making different moral decisions for patients who are in terrible conditions. Therefore, nurses in burn units experience moral distress as mental tension. This study was conducted to determine the severity of moral distress and the factors associated with that in burn nurses. Materials and methods: A descriptive- analytical study was conducted using census sampling on 172 nurses working in Mazandaran burn center, 2014. Data was collected through identifying demographic and occupational characteristics of the nurses (using relevant questionnaires) and Corley’s Moral Distress Scale. Data analysis was performed applying Mann-Whitney and Kruskal-Wallis test. Results: The mean score for moral distress was 105.65±52.39 which indicates a moderate level experienced by nurses. Kruskal-Wallis test showed a significant positive correlation between educational level and level of moral distress (P=0.011). There was no significant association between moral distress and other individual and professional characteristics (P>0.05). Conclusion: Moral distress is accompanied by many complications that have direct effects on nurses’ professional practice. Therefore, nurse managers should consider this issue and plan for programs on appropriate coping strategies. © 2015, Mazandaran University of Medical Sciences. All rights reserved

The comparison of knee joint position sense in soccer player, volleyball player and non-athlete men

زمینه و هدف: حس عمقی و تعادل از عوامل موثر بر ارتقای عملکرد و پیشگیری از آسیب‌های ورزشی اند، اما تأثیر شرکت در فعالیت‌های ورزشی مختلف بر این حس کمتر مطالعه شده است؛ بنابراین این مطالعه با هدف مقایسه حس وضعیت مفصل زانو در مردان فوتبالیست، والیبالیست و غیر ورزشکار انجام شده است. روش بررسی: در این مطالعه مقطعی 45 نفر آزمودنی شامل 15 نفر فوتبالیست، 15 نفر والیبالیست و 15 نفر غیر ورزشکار شرکت کردند. حس وضعیت مفصل زانوی پای غالب این آزمودنی‌ها از طریق بازسازی زوایای 15،30 و 60 درجه فلکشن با چشمان بسته و در زنجیره حرکتی بسته با استفاده از الکتروگونیامتر ارزیابی شد. به منظور تحلیل داده‌ها از آزمون تحلیل واریانس یک سویه و آزمون تعقیبی توکی استفاده شد. یافته‌ها: نتایج نشان داد میانگین خطای مطلق در بازسازی زاویه 60 درجه، در والیبالیست ها به طور معنی داری از خطای مطلق فوتبالیست ‌ها و غیر ورزشکاران کمتر است (p0.05). نتیجه گیری: والیبالیست ها در بازسازی زاویه 60 درجه دارای حس وضعیت مفصل زانوی بهتری هستند. احتمالاً تمرینات پلایومتریک خصوصاً تمرینات پرش- فرود با وزن بدن به بهبود حس وضعیت مفصل زانو کمک می‌کند

A proximal femur aneurysmal bone cyst resulting in amputation: A rare case report

Aneurysmal bone cyst (ABC) is blood filled expansile cystic lesion that most commonly occurs in patients during the second decade of their lives. Traditionally it has been described as a benign lesion but can be locally aggressive and result in the destruction of the involved bone. Treatment methods include surgical excision and curettage with or without bone grafting. We report a proximal femur aneurysmal bone cyst, which resulted in the amputation of the lower extremity, even though all available classic methods of treatment were applied for it. © 2015 Tehran University of Medical Sciences. All rights reserved

An Examination of the Errors Committed by Iranian MA Students in their Translation of Advertisement Slogans Based on Keshavarz’s Taxonomy of Errors

The present work is an attempt to reveal the nature of translating advertisement slogans over two different cultures by investigating the errors that will occur by Iranian MA translation students in translating a corpus of advertisements from English into Persian and vice versa. The sample of this study consisted of sixty MA students of translation studies who were randomly selected from three Azad university branches (Fars Science and Research branch, Tehran Science and Research and Bandar Abbas Azad University). The instruments used for data collection included a questionnaire consisted of eight advertising slogans in English and seven in Persian for products that were internationally marketed. The statistical procedure to analyze the data was Chi-square procedure to illustrate the frequency and percentage of errors occurrence. The results demonstrated that the ratio of wrong answers in the two languages is not the same. Generally, participants committed more errors in the translation of the Persian advertisement slogans comparing to English ones. Most errors participants committed in Persian translation slogans were related to grammatical and lexical interferences and most errors participants committed in English translation slogans were related to misunderstanding and misinterpretation of semantic and pragmatic aspects of the slogans