bluuebunny/crossref_metadata_2025 huggingface dataset:
Propuesta de un sistema neuro-DBR y su aplicación en la predicción de la serie de tiempo de Lorenz
Authors: Morales Laguado Lina , Espitia Cuchango Helbert , Soriano Méndez José
Published: June 2016

Este artículo propone la predicción de la serie de tiempo Lorenz usando un nuevo método conocido como sistema Neuro-DBR y su comparación, con un diseño Neurodifuso convencional. La técnica Neuro-DBR es el resultado de la unión de las redes neuronales y la metodología de Defuzificación basada en relaciones booleanas (DBR). La teoría DBR pretende facilitar la implementación de una inferencia difusa y mejorar el tiempo de procesamiento de los sistemas difusos, para obtener a su vez, un buen desempeño. Los sistemas Neuro-DBR tratan de explotar la complementariedad que existe entre ambas técnicas, aprovechando las ventajas y eludiendo las desventajas de cada una de ellas. En una primera parte, se presenta el algoritmo de entrenamiento Neuro-DBR propuesto para identificar sistemas no lineales. Después, se presenta el diseño del identificador para las Ecuaciones de Lorenz, usando un sistema Neuro-DBR y comparándolo con un diseño Neurodifuso convencional mediante la raíz del error cuadrático medio (RMSE), y el coeficiente de correlación (IC), como índices de desempeño. Los resultados obtenidos con el sistema propuesto, muestran la reducción del tiempo de entrenamiento y cálculo computacional. La teoría relacionada con lógica y conjuntos booleanos es una buena herramienta para diseñar de automatismos y sistemas digitales; una variación con la cual se busca mejorar los sistemas basados en automatismos consiste en emplear conjuntos difusos en lugar de booleanos. Lo anterior se realiza con el objetivo de tener una acción continua en el actuador del automatismo. Al realizar esta variación y aplicar la metodología de diseño de los sistemas de automatismos, aparecen los sistemas de inferencia difusa basados en relaciones booleanas.
Modelado con redes de Petri e implementación con GRAFCET de un sistema de manufactura flexible con procesos concurrentes y recursos compartidos
Authors: Castellanos Arias Johanna Stella , Solaque Guzmán Leonardo Enrique
Published: June 2016

En este trabajo, se presenta el modelado de un Sistema de Manufactura Flexible (SMF), con procesos concurrentes y recursos compartidos mediante Sistemas a Eventos Discretos (SED), específicamente Redes de Petri (RdP), y GRAFCET. El SMF se plantea como un modelo hipotético que se modela con una RdP con el objeto de identificar su dinámica y hallar la secuencia óptima de funcionamiento del sistema. Se desarrolló un modelo matemático que permite estimar el vector de tiempo acumulado de un proceso modelado mediante una RdP, el cual constituye la base para hallar la mejor secuencia posible del sistema modelado. Por último, se realizó una implementación en el Laboratorio de Automatización de la Universidad Militar Nueva Granada, que simula el funcionamiento del SMF modelado por un montaje electrohidroneumático controlado con GRAFCET mediante PLC.
The MINT Countries: A Regression Analysis of the Selected Economic Features
Authors: Kokotović Filip , Kurečić Petar
Published: June 2016

The BRIC countries – Brazil, Russia, India, and China – are being considered as potential powerhouses of the world economy. These countries have formalized their cooperation, and later, with the joining of South Africa, became the BRICS. They are often perceived as proponents of a multipolar world, choosing multipolarity over unipolarity, and supporting political institutions and organizations, at the same time creating alternative financial institutions to the hegemonic ones (the IMF and the World Bank), still dominated by the developed economies of the Western countries. So, what about a different group of countries, called the MINT countries or simply the MINTs that are emerging, growing economies, are heterogeneous as BRICS, but not nearly as large and powerful, and are located on four different continents, with no formal cooperation between themselves such as the BRICS? This article analyses the basic economic trends in the MINT countries by analyzing the linear relationship between GDP as the dependent variable and household consumption, foreign direct investment and government consumption as the independent variables. The general model is as follows: Δ log GDPt = α0 + α1 Δ log FDIt + α2 Δ log PCt + α3 Δ log GCt +εt. The analysis was conducted using ordinary least squares (OLS) regression. By conducting this analysis, it is possible to conclude that the MINT countries have significant differences in regards to the statistical relevance of the chosen independent variables. One of the rare common traits of these four economies is that FDI does not seem to have a statistically significant impact on their development. This article concludes that the MINT countries may have a significant role in international relations as regional powers, but they do not have the economic or political traits necessary to challenge the BRICS countries significantly.
The Impact of National Environment of a Company on Its Financial Policy
Authors: Belanová Katarína
Published: June 2016

The current business world is a subject of constant changes, which are caused by the growing instability of business environment, both in national and global scale. The paper deals with one of these two parts, namely with the national environment. It consists of factors and conditions that arise independently from the will of the company. The company can not influence the conditions; it can only adjust to them that means to use potential opportunities or avoid threats. The aim of the paper is to present those parts of the social surroundings, which have the most significant influence on the financial decisions of a company. Regarding this, we analyze the development of the basic macroeconomic indicators of the Slovak Republic.
Sustainable initiatives in marginal rural areas of Serbia: A case study of Dimitrovgrad municipality
Authors: Rodriguez Juan-Pablo
Published: June 2016

his paper is based on a 2009 case study research on the role and impacts of rural initiatives in Dimitrovgrad, South-eastern Serbia region. This area is of interest, because of local efforts to conserve autochthonous livestock breeds,andtheworkofsmallholdersandindependent professionals involved farming and rural tourism activities. The research used participant visits to initiative places, drawing on farm visits, meetings with stakeholders and analysis of secondary information. The study highlights that local organizations are running without link to initiatives.Although, Serbia country has well structured rural developments programs, those still are harmonising.Thus, throughActor-Network approach is suggested which turn around a farm manager. This may represent to all stakeholders with initiatives (on-farm and non-farm). Besides, local food products issues from initiatives may reconnect providers and consumers, revaluing local food products. However, is necessary the institutional and organizational involvement to encourage the initiatives. Furthermore, to promote touristic places, by an integrated rural tourism approach it may involve all stakeholders to promote local products and issues from initiatives. Indirectly it may create local employs.
The future role of agriculture in multifunctional rural development
Authors: Kovtun Elena , Gnatyshak Kateryna , Chornenka Lyudmyla
Published: June 2016

This paper is focused on analysis and evaluation of the future role of agriculture in multifunctional rural development in Ukraine and also reviewing of the significant basic factors which have influence on it.
Dutch, Hungarian and German dairy farms technical efficiency comparison
Authors: Kovács Krisztián , Emvalomatis Grigorios
Published: June 2016

The abolishment of the dairy quota system in the EU is expected to increase competition across dairy farms in Europe. Assuming a common price for milk in the EU, only the most efficient farms will survive in the new environment. The main objective of the paper is to compare dairy farms in Germany, The Netherlands and Hungary about their technical efficiency. In the first part of the research, the efficiency is measured by partial efficiency indexes using one dimensional efficiency measuring. In the second part, the Data Envelopment Analysis (DEA) have to be used to measure efficiency in a multidimensional space, using six inputs and two outputs. It appears from the results that the highest efficiency farms are in the Netherlands, and then Germany and Hungary follow. If we want to eliminate the low sample size effect, we can assume a common frontier, which decreases the efficiency scores a bit, and makes the Hungarian results more reliable. With respect the abolishment of the dairy quota system, our results suggest that the Dutch farms are the most efficient, thus probably they will increase their production after the quota system. But because the size of the country we cannot expect dramatic changes in the European Dairy market. The Germans farms efficiency is lower, but their efficiency is also lower, so we won’t expect high increase about the dairy supply. The Hungarian dairy sector is not so efficient like the Dutch, and the size of the sector has also small among the European countries, thus if they want to survive the quota system demolishing, they have to increase their technical efficiency.
Exploitation of relations among the players of the mutton product cycle
Authors: Cehla Béla , Kovács Sándor , Nábrádi András
Published: June 2016

The continuous weakening of Hungarian sheep sector and its low effectiveness in terms of value added have posed crucial problems in recent years.The focal problem has been partially caused by economic and market problems.Among these issues, mostly the poor mutton supply chain gives rise to difficulties; therefore the present study seeks to reveal the factors/input variables which predominantly influence the generation of value added. We have constructed a model for the mutton product cycle to represent the relations of phases but mutton trade is not included.The most significant aim of our investigation was to identify the volume of value added generated during processing in various phases of the product cycle and the change of which inputs affected this volume. The received findings suggested that in case of capital uniformity the output of processing was mostly influenced by sheep progeny on the bottom level of the mutton product cycle.
Future role of agriculture in multifunctional development of rural areas
Authors: Runowski Henryk , Zietara Wojciech
Published: June 2016

In the paper the changes in agriculture in terms of falling share of agriculture in gross domestic product and decrease in the share of persons employed in agriculture in total employment in Poland and selected countries are discussed.The main driver of these changes is a faster pace of development of non-agricultural activities and continually deteriorating relations between the costs of production factors and prices of agricultural products. The rate of growth in labor costs and prices of the means of production for agriculture is much faster than the rate of increase in prices of agricultural products.This causes the decline in profitability of agricultural production which increases the size of farms. The pace is dependent on the level of economic development of the country. The study also identified trends in the structure of farms, functions and systems of agriculture in the generational perspective. The polarization of the farms will deepen.A strong group of commodity farms and a group of so-called self – subsistence social farms will emerge. Agriculture in Poland will have a dual nature. In addition to the production function and social services agriculture will expand the scope of service functions for the environment and society.
Safety and security in the age of global tourism
Authors: Kővári István , Zimányi Krisztina
Published: June 2016

Safety and security have always been indispensable condition for travel and tourism. Research and education also has to face the issues of security and safety in tourism in order to prepare future specialists of the industry by incorporating new results of research to academic curricula.
Comparative analysis of menus in the Northern and Southern Great Plain touristic regions
Authors: Sándor Dénes
Published: June 2016

The background of the study is based on previous studies dealing with the areas of Transdanubia and Central Hungary. Those works have proved the hypothesis of author that local ingredients and dishes represent minimum role on menus. The question is how similar or different the choice of menus of Northern and Southern Great Plain is from the previously examined areas of Hungary.Additional questions may also arise in terms of the usage of local ingredients available near catering units. This piece of work has studied several menus of Northern and Southern Great Plain, Hungary. The material was collected from different types of restaurants, ‘csárda’-s and inns. The methodology was two-tier: data collecting on the one hand, and the detailed examination of differences between the catering units on the other hand: the number of dishes, the right order of dishes, the appearance of local ingredients and dishes, the consideration of seasonality, the usage of different cooking methods and group of dishes. The study reflects the main problems of countryside restaurants in Hungary. Only a minimum number of dishes could be connected to local dishes out of more thousands.All in all, dishes are not as precise and perfect as the ‘old ones’used to be; that is why it is important for every expert to keep traditions alive in daily routines and by way of strategic means too.
Globalisation of commercial theme parks case: The Walt Disney Company
Authors: De Groote Patrick
Published: June 2016

In this contribution we focus on the globalisation of commercial theme parks with Walt Disney Company as the best known case study. After definitions and historical background of theme parks, we analyse the visitors key factors. For the Walt Disney Cie we start with some historical facts, we set up a SWOT-analysis and focus then on Euro Disneyland Paris, the biggest theme park of Europe.
New types of tourism and tourism marketing in the post-industrial world
Authors: Árva László , Deli-Gray Zsuzsa
Published: June 2016

At the end of the 20th century in the most developed countries economy and society went through profound transformation. The emerging post-industrial society can be characterised by the dominance of service industry, more leisure time of the population, higher disposable income and more conscious consumers. These conscious consumers are more and more quality orientated and reject undifferentiated mass products. New customers of tourism and hospitality industry are not only more affluent – so less price conscious – and more quality orientated but they are also seeking activity, participation, fantasy, and experience. These new types of tourists are interested rather in aesthetic aspects of life and are seeking highly differentiated, personalised experience. In the following article the authors, professors of the French ESSCA business school overview theoretical aspects of new, post-Fordist tourism demand and present examples of the new tourism and hospitality products having emerged in the developed countries during the last years.
Changing patterns in hotel room demand – case study of the Aquaticum Debrecen Thermal and Wellness Hotel
Authors: Hevessy Gábor
Published: June 2016

Aquaticum Debrecen Thermal and Wellness Hotel is a very successful lodging property not only in Debrecen but also in the Northern Great Plain Region and in the Eastern part of Hungary and in point of fact in Hungary. In the past years Aquaticum Thermal and Wellness Hotel has been the leader in the region by revenue per available rooms (RevPAR). RevPAR indicates the overall performance of properties, accordingly it is the most commonly used statistical indicator in comparison to competitors in Hotel industry. In the past years, demand for Hotel rooms has changed. This changing has several signs. For instance the occupancy rate, the rate of domestic and foreign guests, the nationality of foreign guests, the time between booking and travelling, and many other demand patterns have changed. During the last year, the changing has been accelerated by the global economic crisis. Guests are waiting with their bookings hoping for better rates and last minute offers. The forecast of demand became much harder than ever before. These forecasts are basic ingredients of the revenue management systems, which systems are in use or will be in use by Hungarian Hotels. These systems are necessary to keep RevPAR at a higher level and to help Hotels to achieve better performance.
Networking on the utilization of local natural resources
Authors: Herbály-Hekli Katalin
Published: June 2016

Together with its partners, Szolnok College is planning to evaluate a new project for networking on the utilization of local natural resources. This project is based on a research work (using the findings of the surveys completed by the representatives of hosts living in the eastern part of Hungary). The project itself is based on the adaptation of the theory of tourism into practice by presenting existing natural values in the supply portfolio of tourist service providers. A unique natural environment can be found alongside a 120 km-long stretch of River Tisza. These natural values interlink and complete each other with respect to Lake Tisza and River Tisza. Regions and settlements situated further from the specified settlements are also rich in natural values which guests will definitely be pleased to get acquainted with. The six landscape centres (including LHH regions) alongside river Tisza (in the two regions) symbolise the interdependent system of the sample area of the project while a single landscape centre in the Pásztó Minor Region embodies a unique character. A register will be prepared for each landscape centre containing unique natural values that can be involved in the tourist supply and handicraft/economic activities (e.g. basket weaving, floodplain economy) that are or can be built on these natural values. A pictorial English/German-Hungarian professional dictionary summarises the distinctive nature of landscape centres. The education material demonstrating the registers is going to be developed both in conventional and electronic form; its spatial IT appearance on the Internet is considered a special feature. The education material will be supplemented with other information currently missing such as those related to environmentally friendly economy, and the legal context. The methodology allows the adaptation of the method in other regions, even in the whole country. The new qualifying and benchmarking system and the trademark managed by a profession-specific cluster that strengthens network co-operation and controls the development guarantee the achievement of high quality tourism.
The Dilemma of the TVET Teacher in Developing Countries in the 21st Century
Authors: Edwin Obwoge Makworo
Published: June 2016

Technology is a very dynamic commodity and keeping up with the ever changing trends in various technologies is an issue of great concern for many technologists in the 21st century. Technology changes every 18 months and hence the practitioners need to keep up with the pace in order to remain relevant. The Technical and Vocational Education and Training (TVET) sector is often most affected since it trains technologists for the industrial sector in most developed and developing economies. The TVET instructor always finds himself in a dilemma since skills get obsolete quickly yet he has to continue delivering content in area of specialty. As the industrial sectors demands change, so should the skills of the TVET instructor change to match the ever changing trends of the industry. In most developing countries, there are no set out mechanisms of re-skilling the TVET instructor to keep him updated with the latest technologies in the private sector. This paper reviews literature on the dilemma of the TVET instructor in the 21st century and make recommendations for implementation in developing countries.
E-Learning in TVET: An Opportunity for Developing Countries
Authors: Edwin Obwoge Makworo , Stela Kwamboka Okemwa
Published: June 2016

Education systems in the world today are undergoing major shifts in their delivery systems to be able to accommodate shifting demands in the lifestyles of people. ICT has greatly influenced the way institutions operate in reaching and providing services to their clients. Many educational institutions have adapted their situations to meet the work demands and changing trends in education by adopting e-learning as a mechanism to reach the students who may have no time to sit in class due to their nature of work. TVET systems in Africa are slowly and steadily also starting to move towards implementing e-learning in their teaching learning process. This paper gives insight into the potential and situation of e-learning in TVET institutions in developing countries in Africa and points out major recommendations on how to improve in order to inform policy makers and other stakeholders in the TVET sector.
Educational Tourism’s Product Strategy at Batur Global Geopark, Kintamani - Bali
Authors: Arcana Komang Trisna Pratiwi , Wiweka Kadek
Published: June 2016

Educational tourism is one of tourism type from the form of alternative tourism that has been developed between the conventional tourism era and modern tourism era. Generally, alternative tourism tends to develop according to sustainability principals. The packaging of tourism destination potential, Batur Global Geopark into educational tourism is a fundamental step of tourism product’s diversification in Bali. Therefore, the tourism potential in Batur-caldera Bali is supporting to be developed or packaged as an educational tourism, which is in accordance with Global Geopark Network (GGN) objectives. This study combines the quantitative and qualitative methodologies (multi-method), which are presented in the form of descriptions. The information will be analysed to determine the strengths, weaknesses, opportunities and threats (SWOT). It formulated appropriate educational tourism product strategies by the elements; attraction, accessibilities, amenities, a supporting organisation (ancillary), activity, available package and community involvement. Furthermore, this study will also identify the factors of strengths, weaknesses, opportunities, and challenges of educational tourism product development in the tourist area of Batur Global Geopark.
Functional and Cognitive Impairment, Frailty, and Adverse Health Outcomes in Older Patients Reaching ESRD—A Systematic Review
Authors: Kallenberg Marije H. , Kleinveld Hilda A. , Dekker Friedo W. , van Munster Barbara C. , Rabelink Ton J. , van Buren Marjolijn , Mooijaart Simon P.
Published: June 2016

Background and objectives

Older patients reaching ESRD have a higher risk of adverse health outcomes. We aimed to determine the association of functional and cognitive impairment and frailty with adverse health outcomes in patients reaching ESRD. Understanding these associations could ultimately lead to prediction models to guide tailored treatment decisions or preventive interventions.

Design, setting, participants, & measurements

We searched MEDLINE, Embase, Web of Science, CENTRAL, CINAHL, PsycINFO, and COCHRANE for original studies published until February 8, 2016 reporting on the association of functional or cognitive impairment or frailty with adverse health outcome after follow-up in patients reaching ESRD either with or without RRT.

Results

Of 7451 identified citations, we included 30 articles that reported on 35 associations. Mean age was >60 years old in 73% of the studies, and geriatric conditions were highly prevalent. Twenty-four studies (80%) reported on functional impairment, seven (23%) reported on cognitive impairment, and four (13%) reported on frailty. Mortality was the main outcome measure in 29 studies (97%), and one study assessed functional status trajectory. In 34 of 35 (97%) associations reported, functional or cognitive impairment or frailty was significantly and independently associated with adverse health outcomes. The majority of studies (83%) were conducted in selected patient populations, mainly patients on incident dialysis.

Conclusions

Functional and cognitive impairment and frailty in patients reaching ESRD are highly prevalent and strongly and independently associated with adverse health outcomes, and they may, therefore, be useful for risk stratification. More research into their prognostic value is needed.
Transtentorial transcollateral sulcus approach to the ventricular atrium: an endoscope-assisted anatomical study
Authors: Jeelani Yasser , Gokoglu Abdulkerim , Anor Tomer , Al-Mefty Ossama , Cohen Alan R.
Published: June 2016

OBJECTIVE

Conventional approaches to the atrium of the lateral ventricle may be associated with complications related to direct cortical injury or brain retraction. The authors describe a novel approach to the atrium through a retrosigmoid transtentorial transcollateral sulcus corridor.

METHODS

Bilateral retrosigmoid craniotomies were performed on 4 formalin-fixed, colored latex–injected human cadaver heads (a total of 8 approaches). Microsurgical dissections were performed under 3× to 24× magnification, and endoscopic visualization was provided by 0° and 30° rigid endoscope lens systems. Image guidance was provided by coupling an electromagnetic tracking system with an open source software platform. Objective measurements on cortical thickness traversed and total depth of exposure were recorded. Additionally, the basal occipitotemporal surfaces of 10 separate cerebral hemisphere specimens were examined to define the surface topography of sulci and gyri, with attention to the appearance and anatomical patterns and variations of the collateral sulcus and the surrounding gyri.

RESULTS

The retrosigmoid approach allowed for clear visualization of the basal occipitotemporal surface. The collateral sulcus was identified and permitted easy endoscopic access to the ventricular atrium. The conical corridor thus obtained provided an average base working area of 3.9 cm2 at an average depth of 4.5 cm. The mean cortical thickness traversed to enter the ventricle was 1.4 cm. The intraventricular anatomy of the ipsilateral ventricle was defined clearly in all 8 exposures in this manner. The anatomy of the basal occipitotemporal surface, observed in a total of 18 hemispheres, showed a consistent pattern, with the collateral sulcus abutted by the parahippocampal gyrus medially, and the fusiform and lingual gyrus laterally. The collateral sulcus was found to be caudally bifurcated in 14 of the 18 specimens.

CONCLUSIONS

The retrosigmoid supracerebellar transtentorial transcollateral sulcus approach is technically feasible. This approach has the potential advantage of providing a short and direct path to the atrium, hence avoiding violation of deep neurovascular structures and preserving eloquent areas. Although this approach appears unconventional, it may provide a minimally invasive option for the surgical management of selected lesions within the atrium of the lateral ventricle.
Radiation exposure in spine surgery using an image-guided system based on intraoperative cone-beam computed tomography: analysis of 107 consecutive cases
Authors: Costa Francesco , Tosi Giovanni , Attuati Luca , Cardia Andrea , Ortolina Alessandro , Grimaldi Marco , Galbusera Fabio , Fornari Maurizio
Published: June 2016

OBJECTIVE

The O-arm system in spine surgery allows greater accuracy, lower rate of screw misplacement, and reduced surgical time. Some concerns have been postulated regarding the radiation doses to patients and surgeons. To the best of the authors' knowledge, most of the studies in the literature were performed with the use of phantoms. The authors present data regarding radiation exposure of the surgeon and operating room (OR) staff in a consecutive series of patients undergoing spine surgery.

METHODS

Radiation exposure data were collected in a series of 107 patients who underwent spine surgery using the O-arm system. The doses received by the surgeon and the staff were collected using electronic dosimeters.

RESULTS

All patients underwent 1–3 scans. The mean radiation dose to the patients was 5.15 mSv (range 1.48–7.64 mSv). The mean dose registered for the scan operator was 0.005 μSv (range 0.00–0.03 μSv) while the other members of the surgical team positioned outside the OR received 0 μSv.

CONCLUSIONS

The O-arm system exposes patients to a higher radiation dose than standard fluoroscopy. However, considering the clear advantages of this system, this adjunctive dose can be considered acceptable. Moreover, the effective dose to the patient can be reduced using collimation or minimizing the parameters of the O-arm system used in this paper. The exposure to operators is essentially negligible when radioprotective garments and protocols are adopted as recommended by the International Commission on Radiological Protection.
Single-unit analysis of the human posterior hypothalamus and red nucleus during deep brain stimulation for aggressivity
Authors: Micieli Robert , Rios Adriana Lucia Lopez , Aguilar Ricardo Plata , Posada Luis Fernando Botero , Hutchison William D.
Published: June 2016

OBJECTIVE

Deep brain stimulation (DBS) of the posterior hypothalamus (PH) has been reported to be effective for aggressive behavior in a number of isolated cases. Few of these case studies have analyzed single-unit recordings in the human PH and none have quantitatively analyzed single units in the red nucleus (RN). The authors report on the properties of ongoing neuronal discharges in bilateral trajectories targeting the PH and the effectiveness of DBS of the PH as a treatment for aggressive behavior.

METHODS

DBS electrodes were surgically implanted in the PH of 1 awake patient with Sotos syndrome and 3 other anesthetized patients with treatment-resistant aggressivity. Intraoperative extracellular recordings were obtained from the ventral thalamus, PH, and RN and analyzed offline to discriminate single units and measure firing rates and firing patterns. Target location was based on the stereotactic coordinates used by Sano et al. in their 1970 study and the location of the dorsal border of the RN.

RESULTS

A total of 138 units were analyzed from the 4 patients. Most of the PH units had a slow, irregular discharge (mean [± SD] 4.5 ± 2.7 Hz, n = 68) but some units also had a higher discharge rate (16.7 ± 4.7 Hz, n = 15). Two populations of neurons were observed in the ventral thalamic region as well, one with a high firing rate (mean 16.5 ± 6.5 Hz, n = 5) and one with a low firing rate (mean 4.6 ± 2.8 Hz, n = 6). RN units had a regular firing rate with a mean of 20.4 ± 9.9 Hz and displayed periods of oscillatory activity in the beta range. PH units displayed a prolonged period of inhibition following microstimulation compared with RN units that were not inhibited. Patients under anesthesia showed a trend for lower firing rates in the PH but not in the RN. All 4 patients displayed a reduction in their aggressive behavior after surgery.

CONCLUSIONS

During PH DBS, microelectrode recordings can provide an additional mechanism to help identify the PH target and surrounding structures to be avoided such as the RN. PH units can be distinguished from ventral thalamic units based on their response to focal microstimulation. The RN has a characteristic higher firing rate and a pattern of beta oscillations in the spike trains. The effect of the anesthetic administered should be considered when using microelectrode recordings. The results of this study, along with previous reports, suggest that PH DBS may be an effective treatment for aggression.
Incidence of intraoperative seizures during motor evoked potential monitoring in a large cohort of patients undergoing different surgical procedures
Authors: Ulkatan Sedat , Jaramillo Ana Maria , Téllez Maria J. , Kim Jinu , Deletis Vedran , Seidel Kathleen
Published: June 2016

OBJECTIVE

The purpose of this study was to investigate the incidence of seizures during the intraoperative monitoring of motor evoked potentials (MEPs) elicited by electrical brain stimulation in a wide spectrum of surgeries such as those of the orthopedic spine, spinal cord, and peripheral nerves, interventional radiology procedures, and craniotomies for supra- and infratentorial tumors and vascular lesions.

METHODS

The authors retrospectively analyzed data from 4179 consecutive patients who underwent surgery or an interventional radiology procedure with MEP monitoring.

RESULTS

Of 4179 patients, only 32 (0.8%) had 1 or more intraoperative seizures. The incidence of seizures in cranial procedures, including craniotomies and interventional neuroradiology, was 1.8%. In craniotomies in which transcranial electrical stimulation (TES) was applied to elicit MEPs, the incidence of seizures was 0.7% (6/850). When direct cortical stimulation was additionally applied, the incidence of seizures increased to 5.4% (23/422). Patients undergoing craniotomies for the excision of extraaxial brain tumors, particularly meningiomas (15 patients), exhibited the highest risk of developing an intraoperative seizure (16 patients). The incidence of seizures in orthopedic spine surgeries was 0.2% (3/1664). None of the patients who underwent surgery for conditions of the spinal cord, neck, or peripheral nerves or who underwent cranial or noncranial interventional radiology procedures had intraoperative seizures elicited by TES during MEP monitoring.

CONCLUSIONS

In this largest such study to date, the authors report the incidence of intraoperative seizures in patients who underwent MEP monitoring during a wide spectrum of surgeries such as those of the orthopedic spine, spinal cord, and peripheral nerves, interventional radiology procedures, and craniotomies for supra- and infratentorial tumors and vascular lesions. The low incidence of seizures induced by electrical brain stimulation, particularly short-train TES, demonstrates that MEP monitoring is a safe technique that should not be avoided due to the risk of inducing seizures.
Neurosurgery at the University of Miami
Authors: Alberga Linda , Menendez Ingrid , Landy Howard J. , Morcos Jacques J. , Levi Allan D.
Published: June 2016

The Department of Neurological Surgery at the University of Miami/Jackson Memorial Hospital's legacy of patient care, teaching, and research in the neurosciences extends over a period of 50 years. The department's founder was Dr. David Reynolds. The subsequent chairman, Dr. Hubert Rosomoff, formed a solid foundation that helped put the department on the map. Drs. Barth Green and Roberto Heros, the immediate past chair and co-chairman, garnered both national and international attention for the department. Dr. Green focused his career on complex spine and spinal cord disorders, and was pivotal in creating the world's largest research center for spinal cord injuries. Dr. Heros is a master educator and pioneer neurovascular surgeon, as well as a former president of several neurosurgical national and international organizations. In aggregate, the department has made major contributions to the foundations of neurosurgery.
CT-based morphometric analysis of the occipital condyle: focus on occipital condyle screw insertion
Authors: Zhou Jinsong , Espinoza Orías Alejandro A. , Kang Xia , He Jade , Zhang Zhihai , Inoue Nozomu , An Howard S.
Published: June 2016

OBJECTIVE

The segmental occipital condyle screw (OCS) is an alternative fixation technique in occipitocervical fusion. A thorough morphological study of the occipital condyle (OC) is critical for OCS placement. The authors set out to introduce a more precise CT-based method for morphometric analysis of the OC as it pertains to the placement of the segmental OCS, and they describe a novel preoperative simulation method for screw placement. Two new clinically relevant parameters, the height available for the OCS and the warning depth, are proposed.

METHODS

CT data sets from 27 fresh-frozen human cadaveric occipitocervical spines were used. All measurements were performed using a commercially available 3D reconstruction software package. The length, width, and sagittal angle of the condyle were measured in the axial plane at the base of the OC. The height of the OC and the height available for the segmental OCS were measured in the reconstructed oblique sagittal plane, fitting the ideal trajectory of the OCS recommended in the literature. The placement of a 3.5-mm-diameter screw that had the longest length of bicortical purchase was simulated into the OC in the oblique sagittal plane, with the screw path not being blocked by the occiput and not violating the hypoglossal canal cranially or the atlantooccipital joint caudally. The length of the simulated screw was recorded. The warning depth was measured as the shortest distance from the entry point of the screw to the posterior border of the hypoglossal canal.

RESULTS

The mean length and width of the OC were found to be larger in males: 22.2 ± 1.7 mm and 12.1 ± 1.0 mm, respectively, overall (p < 0.0001 for both). The mean sagittal angle was 28.0° ± 4.9°. The height available for the OCS was significantly less than the height of the OC (6.2 ± 1.3 mm vs 9.4 ± 1.5 mm, p < 0.0001). The mean screw length (19.3 ± 1.9 mm) also presented significant sex-related differences: male greater than female (p = 0.0002). The mean warning depth was 7.5 ± 1.7 mm. In 7.4% of the samples, although the height of the OC was viable, the height available for the OCS was less than 4.5 mm, thus making screw placement impractical. For these cases, a new preoperative simulation method of the OCS placement was proposed. In 92.6% of the samples that could accommodate a 3.5-mm-diameter screw, 24.0% showed that the entry point of the simulated screw was covered by a small part of the C-1 posterosuperior joint rim.

CONCLUSIONS

The placement of the segmental OCS is feasible in most cases, but a thorough preoperative radiological analysis is essential and cannot be understated. The height available for the OCS is a more clinically relevant and precise parameter than the height of the OC to enable proper screw placement. The warning depth may be helpful for the placement of the OCS.
Re-irradiation stereotactic body radiotherapy for spinal metastases: a multi-institutional outcome analysis
Authors: Hashmi Ahmed , Guckenberger Matthias , Kersh Ron , Gerszten Peter C. , Mantel Frederick , Grills Inga S. , Flickinger John C. , Shin John H. , Fahim Daniel K. , Winey Brian , Oh Kevin , John Cho B. C. , Létourneau Daniel , Sheehan Jason , Sahgal Arjun
Published: June 2016

OBJECTIVE

This study is a multi-institutional pooled analysis specific to imaging-based local control of spinal metastases in patients previously treated with conventional external beam radiation therapy (cEBRT) and then treated with re-irradiation stereotactic body radiotherapy (SBRT) to the spine as salvage therapy, the largest such study to date.

METHODS

The authors reviewed cases involving 215 patients with 247 spinal target volumes treated at 7 institutions. Overall survival was calculated on a patient basis, while local control was calculated based on the spinal target volume treated, both using the Kaplan-Meier method. Local control was defined as imaging-based progression within the SBRT target volume. Equivalent dose in 2-Gy fractions (EQD2) was calculated for the cEBRT and SBRT course using an α/β of 10 for tumor and 2 for both spinal cord and cauda equina.

RESULTS

The median total dose/number of fractions of the initial cEBRT was 30 Gy/10. The median SBRT total dose and number of fractions were 18 Gy and 1, respectively. Sixty percent of spinal target volumes were treated with single-fraction SBRT (median, 16.6 Gy and EQD2/10 = 36.8 Gy), and 40% with multiple-fraction SBRT (median 24 Gy in 3 fractions, EQD2/10 = 36 Gy). The median time interval from cEBRT to re-irradiation SBRT was 13.5 months, and the median duration of patient follow-up was 8.1 months. Kaplan-Meier estimates of 6- and 12-month overall survival rates were 64% and 48%, respectively; 13% of patients suffered a local failure, and the 6- and 12-month local control rates were 93% and 83%, respectively. Multivariate analysis identified Karnofsky Performance Status (KPS) < 70 as a significant prognostic factor for worse overall survival, and single-fraction SBRT as a significant predictive factor for better local control. There were no cases of radiation myelopathy, and the vertebral compression fracture rate was 4.5%.

CONCLUSIONS

Re-irradiation spine SBRT is effective in yielding imaging-based local control with a clinically acceptable safety profile. A randomized trial would be required to determine the optimal fractionation.
Lateral interbody fusion combined with open posterior surgery for adult spinal deformity
Authors: Strom Russell G. , Bae Junseok , Mizutani Jun , Valone Frank , Ames Christopher P. , Deviren Vedat
Published: June 2016

OBJECTIVE

Lateral interbody fusion (LIF) with percutaneous screw fixation can treat adult spinal deformity (ASD) in the coronal plane, but sagittal correction is limited. The authors combined LIF with open posterior (OP) surgery using facet osteotomies and a rod-cantilever technique to enhance lumbar lordosis (LL). It is unclear how this hybrid strategy compares to OP surgery alone. The goal of this study was to evaluate the combination of LIF and OP surgery (LIF+OP) for ASD.

METHODS

All thoracolumbar ASD cases from 2009 to 2014 were reviewed. Patients with < 6 months follow-up, prior fusion, severe sagittal imbalance (sagittal vertical axis > 200 mm or pelvic incidence-LL > 40°), and those undergoing anterior lumbar interbody fusion were excluded. Deformity correction, complications, and outcomes were compared between LIF+OP and OP-only surgery patients.

RESULTS

LIF+OP (n = 32) and OP-only patients (n = 60) had similar baseline features and posterior fusion levels. On average, 3.8 LIFs were performed. Patients who underwent LIF+OP had less blood loss (1129 vs 1833 ml, p = 0.016) and lower durotomy rates (0% vs 23%, p = 0.002). Patients in the LIF+OP group required less ICU care (0.7 vs 2.8 days, p < 0.001) and inpatient rehabilitation (63% vs 87%, p = 0.015). The incidence of new leg pain, numbness, or weakness was similar between groups (28% vs 22%, p = 0.609). All leg symptoms resolved within 6 months, except in 1 OP-only patient. Follow-up duration was similar (28 vs 25 months, p = 0.462). LIF+OP patients had significantly less pseudarthrosis (6% vs 27%, p = 0.026) and greater improvement in visual analog scale back pain (mean decrease 4.0 vs 1.9, p = 0.046) and Oswestry Disability Index (mean decrease 21 vs 12, p = 0.035) scores. Lumbar coronal correction was greater with LIF+OP surgery (mean [± SD] 22° ± 13° vs 14° ± 13°, p = 0.010). LL restoration was 22° ± 13°, intermediately between OP-only with facet osteotomies (11° ± 7°, p < 0.001) and pedicle subtraction osteotomy (29° ± 10°, p = 0.045).

CONCLUSIONS

LIF+OP is an effective strategy for ASD of moderate severity. Compared with the authors' OP-only operations, LIF+OP was associated with faster recovery, fewer complications, and greater relief of pain and disability.
Challenges and Facilities in Health Sector in Bangladesh
Authors: Editor The
Published: June 2016

Abstract not availableBirdem Med J 2015; 5(1): 1-3
Maternal and Fetal Outcome in Patients with Pregestational Diabetes Mellitus and Gestational Diabetes Mellitus and Their Comparison with Non-diabetic Pregnancy
Authors: Naher Nurun , Chowdhury TA , Begum Rahima
Published: June 2016

Objectives: To describe the maternal and fetal outcome in pre-gestational diabetes mellitus and gestational diabetes mellitus and to compare with that of non-diabetic pregnancies.Methods: This cross-sectional study was done in the Department of Obstetrics and Gynaecology of BIRDEM over one year period. Study population were divided in three groups; Group A  pre-gestational diabetes, Group B  gestational diabetes and Group C  non-diabetic patients.Results: Each group had 50 patients. Majority of the patients were multigravida and delivery was at term. Caesarean section was common, 84% in group A, 76% in group B and 72% in group C. Post-partum haemorrage was the commonest maternal complication occurring in 24%, 22% and 22% cases in group A, B and C respectively. Common neonatal complications were respiratory distress syndrome (59.6%, 59.2% and 35% cases of group A, B and C respectively) and hyperbilirubinaemia (95.7%, 73.5% and 85% of cases of group A, B and C respectively). Neonatal hypoglycaemia occurred in 27.7% cases of group A and 18.4% cases of group B. No neonatal hypoglycaemia occurred in nondiabetic group.Conclusion: Incidence of post-partum haemorrhage, respiratory distress syndrome, neonatal hyperbilirubinaemia and hypoglycaemia were more in pre-gestational diabetes group than GDM group than non-diabetic group.Birdem Med J 2015; 5(1): 9-13
A Case of Pregnancy with Ebsteins Anomaly
Authors: Ruman Umme , Chowdhury Tanzeem Sabina , Maherunnessa - , Sultana Rebeka , Nargis Sohelee
Published: June 2016

26- years old multigravida ,developed palpitation and dizziness at 30th gestational weeks and was got admitted in BIRDEM hospital. Her ECG showed ST-depression (anteriors) .Echocardiogram revealed severe atrialized right ventricle, non-restrictive ASD secundum. She was diagnosed as a case of pregnancy with Ebsteins anomaly with ASD. At 34th gestational week, she underwent spontaneous pre-term labour and gave birth to a still born. She developed peripheral cyanosis during pregnancy which subsided few days after delivery.Birdem Med J 2015; 5(1): 46-49
Medical Quiz: Images Vol.5(1)
Authors: Saha Debasish Kumar
Published: June 2016

Abstract not availableBirdem Med J 2015; 5(1): 54
BIRDEM News Vol.5(1)
Authors: Editor The
Published: June 2016

Abstract not availableBirdem Med J 2015; 5(1): 56
From the Desk of the Executive Editor Vol.5(1)
Authors: Uddin Khwaia Nazim
Published: June 2016

Abstract not availableBirdem Med J 2015; 5(1): 63
Microalbumin: Urinary Biomarker of Cardiovascular Risk Assessment
Authors: Samad Tabassum , Haque Wasim Md Mohosin ul
Published: June 2016

Microalbuminuria is an early sign of vascular damage. Now-a-days it is considered as a predictor of worse outcome for both renal and cardiac patients. In this review we investigate the magnitude of relationship between microalbuminuria and incident coronary heart disease and mortality. Microalbuminuria is an independent predictor of coronary heart disease and all cause mortality. It is demonstrated that cardiovascular and renal risk is elevated even in the high normal range of microalbuminuria. Early detection of microalbuminuria, or therapies that prevent or delay the development of microalbuminuria, and all measures that prevent it, may help to prevent or delay cardiovascular eventsBirdem Med J 2015; 5(2): 98-103
Medical Quiz: Single Best Answer (SBA) Vol.5(2)
Authors: Saha Debasish Kumar , Saha Madhurima , Islam Reezwan
Published: June 2016

Abstract not availableBirdem Med J 2015; 5(2): 120
Medical Quiz: SBA  Answers Vol. 5(2)
Authors: Saha Debasish Kumar , Saha Madhurima , Islam Reezwan
Published: June 2016

Abstract not availableBirdem Med J 2015; 5(2): 72