Some applications of linear algebraic methods in combinatorics

In this note, we intend to produce all latin squares from one of them using suitable move which is defined by small trades and do the similar work on 4-cycle systems. These problems, reformulate as finding basis for the kernel of special matrices, representef to some graphs

Vitamin B12 supplementation in end stage renal diseases : A systematic review

Acknowledgements The authors wish to thank Hossein Ansari, Javad Tarrahi, Dr. Sakineh Shabbidar and Dr. Hadi Tabibi for their technical and valuable comments.Peer reviewedPublisher PD

Ideology and Ethics of Transitional Entrepreneurs: Legitimacy, Soft Law, and Overcoming a Distressed Economy

Purpose – Transitional entrepreneurship in distressed economies is a fairly new concept with respect to new ventures in such challenging economic environments. Formal institutional voids are sometimes held up as a reason for the difficulties present in distressed economies, along with exogenous shocks and other upheavals. In this research, the authors seek to contribute empirically and theoretically as to ways in which formal institutions voids can be filled by a culture developed by transitional entrepreneurs. Indeed, in transition economies, formal institutions need to be enhanced by informal institutions to control corruption and other misbehavior by authorities. Iranian economists emphasize these essential reforms to be able to manage current difficulties, yet top down policies cannot help transitional entrepreneurs benefit from the country’s value adding cultural heritage to informally address this. To study this, qualitative research methods were used to interpret transitional entrepreneurs’ ideology and ethical routines as the ingredients of a commercial culture that can establish soft law that substitutes for formal institutions. This helps to reduce the disfunctionality of formal institutions in distressed economies. Design/methodology/approach – A thematic analysis interviewing key Iranian entrepreneurs and economists is conducted. Also based on an interpretive paradigm, a hermeneutic cycle has been carried out on selected texts. Results have been verified throughout related literature as to come up with a solid synthesized interpreted outcome. Findings – This paper contributes to theory from a new perspective by discussing transitional entrepreneurship and navigating a distressed economy; in which, ideology and ethics as the ingredients of soft law (Newman and Posner, 2018) are discussed as the base to further develop a commercial culture that fills voids of formal institutions. The formal–informal institutional cycle in distressed economies as the major difficulty entrepreneurs face (Peng and Luo, 2000) is important, because they try to increasingly enhance their move toward a market orientation (Bruton et al., 2008). The authors contribute as to how transitional entrepreneurs can complete this process of adaptation and also the fact that those informal institutions do actually respond to those adaptations. The other contribution is to enrich theories about institutions from the point of view of culture. Knowing these facts helps transitional entrepreneurs, because in distressed communities, formal institutions’ function has an important effect on economic performance (Amoros, 2009). This research’s contributions shed light to help government leaders understand the pros and cons of their actions forced on the industry. As it has been characterized in this research, it can turn in to new formal set of legitimacies (Ahlstrom et al., 2008) to root out corruption and help set the economy on a path to innovation and new venture creation. Originality/value – Transitional entrepreneurs can depend on the less formal cultural-cognitive aspect of ethics and ideology. These entrepreneurs can be working on the burgeoning private sector, who want to connect with the outside effectively to overcome an economy in distress. Transitional entrepreneurs may face governmental institutional intermediaries as a barrier. Formal intermediaries tend to benefit from inefficiencies caused by hierarchal orders and will improve informality in order to overcome difficulties. In this research, institutional theory from the third pillar of the cultural-cognitive sheds light on transitional entrepreneurship in distressed economies, where inquiry is to fill voids of formal institutions as a process of possible linking between new generated soft law derived by beliefs, ideology and professional morality in order to influence (old) legitimacies. The research’s focus evolves on values transitional entrepreneurs utilize to build informal institutions and then impact further on formal institutions to handle distressed communities. This theoretical background expands on subsections to define conceptual building blocks for the study, essential aspects such as individuals as transitional entrepreneurs, the values they utilize to generate soft law, informal institutions and soft law, to manage voids in formal institutions and legitimacy building aspects in policy agenda setting for transitional entrepreneurship in distressed economies

Diagnostic accuracy of conventional, digital and Cone Beam CT in vertical root fracture detection

INTRODUCTION: Vertical root fracture (VRF) is a common failure in endodontically treated teeth. Due to VRF’s poor prognosis, a reliable and valid detection method is critical for treatment planning. Conventional and digital radiographs are limited in VRF detection. Recently, Cone Beam CT (CBCT) system has been introduced. This study aimed to compare the diagnostic accuracy of these three imaging modalities for VRF detection.MATERIALS & METHODS: One hundred and twenty extracted single-rooted teeth were selected and sectioned through cementoenamel junction. The roots were divided in two groups; group one consisted of 60 teeth with induced root fracture and group two had 60 teeth with no fracture. In the first group the crack was made by instron system. All samples were imaged by the three imaging modalities. Diagnostic accuracy was then compared with methylene blue dye detection method. Kappa was used for statistical analysis. RESULTS: CBCT showed the highest sensitivity (94.6%) and specificity (98.2%). Conventional radiography and digital radiography were not as accurate as CBCT.CONCLUSION: According to our study, CBCT seems to be better than conventional and digital radiography in detecting VRF and provides the most reliable data in comparison with the two other modalities

Leveraging Optimal Transport for Enhanced Offline Reinforcement Learning in Surgical Robotic Environments

Most Reinforcement Learning (RL) methods are traditionally studied in an active learning setting, where agents directly interact with their environments, observe action outcomes, and learn through trial and error. However, allowing partially trained agents to interact with real physical systems poses significant challenges, including high costs, safety risks, and the need for constant supervision. Offline RL addresses these cost and safety concerns by leveraging existing datasets and reducing the need for resource-intensive real-time interactions. Nevertheless, a substantial challenge lies in the demand for these datasets to be meticulously annotated with rewards. In this paper, we introduce Optimal Transport Reward (OTR) labelling, an innovative algorithm designed to assign rewards to offline trajectories, using a small number of high-quality expert demonstrations. The core principle of OTR involves employing Optimal Transport (OT) to calculate an optimal alignment between an unlabeled trajectory from the dataset and an expert demonstration. This alignment yields a similarity measure that is effectively interpreted as a reward signal. An offline RL algorithm can then utilize these reward signals to learn a policy. This approach circumvents the need for handcrafted rewards, unlocking the potential to harness vast datasets for policy learning. Leveraging the SurRoL simulation platform tailored for surgical robot learning, we generate datasets and employ them to train policies using the OTR algorithm. By demonstrating the efficacy of OTR in a different domain, we emphasize its versatility and its potential to expedite RL deployment across a wide range of fields.Comment: Preprin

Plasma Ammonia Levels in Newborns with Asphyxia

How to Cite This Article: Khalessi N, Khosravi N, Mirjafari M, Afsharkhas L. Plasma Ammonia Levels in Newborns with Asphyxia. Iran J Child Neurol. Winter 2016; 10(1):42-46.AbstractObjectivePerinatal asphyxia may result in hypoxic damage in various body organs, especially in the central nervous system. It could induce cascade of biochemical events leading to the cell death and metabolic changes, eventually may increase plasma ammonia levels. The purpose of this study was to determine the prevalence of hyperammonemia in neonates with asphyxia and to find the relationship between ammonia levels and severity of asphyxia.Material & MethodsIn this cross-sectional study, we included 100 neonates with perinatal asphyxia in the Neonatal Intensive Care Unit of Ali-Asghar Hospital, Iran University of Medical Science, Tehran, Iran in 2010-2011. All full term patients diagnosed of asphyxia were enrolled. The relationship between plasma ammonia levels and sex, gestational age, birth weight and severity of asphyxia were determined.Data were analyzed using SPSS software.ResultsFifty six percent of neonates were male. The mean gestational age was 38.0± 1.2 wk. Mean plasma ammonia level was 222 ± 100 μg/dl and 20% of the neonates had hyperammonemia. It was not associated with gender, gestational age, birth weight, and asphyxia severity. Six patients died and mean plasma ammonia levels was 206±122 μg/dl. In this group, there was no significant relation between plasma ammonia levels and severity of asphyxia. No significant different was seen between plasma ammonia in dead and lived neonates.ConclusionAccording to high prevalence of hyperammonemia in neonatal asphyxia, measurement of plasma ammonia levels, is suggested to improve management of asphyxia