FiberBlender: A Realistic Computer Model of Nerve Bundles for Simulating and Validating the Acquisition of Diffusion Tensor Imaging

Diffusion Tensor Imaging (DTI) is a powerful medical imaging technique that provides a unique method to investigate the structure and connectivity of neural pathways. DTI is a special magnetic resonance imaging (MRI) modality that combines the principles of magnetic resonance with molecular diffusion to trace the motion of water molecules. In the central nervous system, where nerve fibers are packed in highly-directional bundles, these molecules diffuse along the orientation of the fibers. Hence, characterizing the motion of water with DTI delivers a non-invasive in vivo technique to capture the connectivity of nerves themselves. Despite its promises and successful clinical applications for nearly thirty years, problems with validation and interpretation of measurements still persist. Most validation studies attempt to generate ground-truth data from animal models, phantoms, and computer models. This dissertation proposes a novel validation system, FiberBlender, capable of reproducing three-dimensional fiber structures and simulating the diffusion of water molecules to generate ground-truth synthetic DTI data. In particular FiberBlender contributes to: (i) creating more biologically accurate representations of fiber bundles with the inclusion of myelin and glial cells, (ii) examining the effect of demyelination and gliosis on DTI measurements, (iii) optimizing acquisition sequences, and (iv) evaluating the performance of multi-tensor models for the study of crossing fibers. FiberBlender strays away from the “one size fits all” approach taken by previous studies and uses computer algorithms in conjunction with some limited manual operations to produce brain-like geometries that take into account the random spatial location of axons and correct distributions of axon diameters, myelin to axon radius, and myelin to glia ratio. In this way no two models are the same and the system is capable of generating structures that can potentially represent any region of the brain and encompass the heterogeneity between human subjects. This feature is essential for optimization as the performance of DTI acquisition sequences may vary among subjects and the type of scanner used. In addition to better accuracy, the system offers a high degree of flexibility as the geometry can be modified to simulate events that cause drastic changes to the fiber structure. Specially, this dissertation looks at demyelination (an extensive loss of myelin volume), gliosis (a proliferation of glial cells), and axon compaction (a condensation of axons due to a loss of total brain volume) to determine their effects on the observed DTI signal. Simulation results confirm that axon compaction and partial remyelination have similar characteristics. Results also show that some standard clinically used acquisition sequences are incapable of capturing the effects of demyelination, gliosis and compaction when performing longitudinal studies. A novel sequence optimization technique based on Shannon entropy and mutual information is proposed to better capture demyelination. Optimized sequences are tested on a number of non-identical models to confirm their validity and can be used to improve the quality of DTI diagnostics. Finally this work looks at crossing fibers for the validation of multi-tensor models in their ability to characterize crossing diffusion profiles. The performance of multi-tensor models from CHARMED, Q-ball and spherical deconvolution that are widely used in both research and clinical settings are evaluated against ground-truth data generated with FiberBlender. The study is performed on a number of different crossing geometries and preliminary results show that the CHARMED model is the most comprehensive approach

A Dynamic Approach to Pose Invariant Face Identification Using Cellular Simultaneous Recurrent Networks

Face recognition is a widely covered and desirable research field that produced multiple techniques and different approaches. Most of them have severe limitations with pose variations or face rotation. The immediate goal of this thesis is to deal with pose variations by implementing a face recognition system using a Cellular Simultaneous Recurrent Network (CSRN). The CSRN is a novel bio-inspired recurrent neural network that mimics reinforcement learning in the brain. The recognition task is defined as an identification problem on image sequences. The goal is to correctly match a set of unknown pose distorted probe face sequences with a set of known gallery sequences. This system comprises of a pre-processing stage for face and feature extraction and a recognition stage to perform the identification. The face detection algorithm is based on the scale-space method combined with facial structural knowledge. These steps include extraction of key landmark points and motion unit vectors that describe movement of face sequqnces. The identification process applies Eigenface and PCA and reduces each image to a pattern vector used as input for the CSRN. In the training phase the CSRN learns the temporal information contained in image sequences. In the testing phase the network predicts the output pattern and finds similarity with a test input pattern indicating a match or mismatch.Previous applications of a CSRN system in face recognition have shown promise. The first objective of this research is to evaluate those prior implementations of CSRN-based pose invariant face recognition in video images with large scale databases. The publicly available VidTIMIT Audio-Video face dataset provides all the sequences needed for this study. The second objective is to modify a few well know standard face recognition algorithms to handle pose invariant face recognition for appropriate benchmarking with the CSRN. The final objective is to further improve CSRN face recognition by introducing motion units which can be used to capture the direction and intensity of movement of feature points in a rotating fac

Evaluation of Wireless Sensor Networks Technologies

Wireless sensor networks represent a new technology that has emerged from developments in ultra low power microcontrollers and sophisticated low cost wireless data devices. Their small size and power consumption allow a number of independent ‘nodes’ (known as Motes) to be distributed in the field, all capable of ad-hoc networking and multihop message transmission. New routing algorithms allow remote data to be passed reliably through the network to a final control point. This occurs within the constraints of low power RF transmissions in a congested 2.4GHz radio spectrum. Wireless sensor network nodes are suitable for applications requiring long term autonomous operation, away from mains power supplies, such as environmental or health monitoring. To achieve this, sophisticated power management techniques must be used, with the units remaining ‘asleep’ in ultra low power mode for long periods of time. The main aim of this research described in this thesis is first to review the area and then to evaluate one of the current hardware platforms and the popular software used with it called TinyOS. Therefore this research uses a hardware platform designed from University of Berkeley, called the TmoteSky. Practical work has been carried out in different scenarios. Using Java tools running on a PC, and customized applications running on the Motes, data has been captured, together with information showing topology configuration and adaptive routing of the network and radio link quality information. Results show that the technology is promising for distributed data acquisition applications, although in time critical monitoring systems new power management schemes and networking protocols to improve latency in the system will be required

Minimum-Energy Exploration and Coverage for Robotic Systems

This dissertation is concerned with the question of autonomously and efficiently exploring three-dimensional environments. Hence, three robotics problems are studied in this work: the motion planning problem, the coverage problem and the exploration problem. The work provides a better understanding of motion and exploration problems with regard to their mathematical formulation and computational complexity, and proposes solutions in the form of algorithms capable of being implemented on a wide range of robotic systems.Because robots generally operate on a limited power source, the primary focus is on minimizing energy while moving or navigating in the environment. Many approaches address motion planning in the literature, however few attempt to provide a motion that aims at reducing the amount of energy expended during that process. We present a new approach, we call integral-squared torque approximation, that can be integrated with existing motion planners to find low-energy and collision-free paths in the robot\u27s configuration space.The robotics coverage problem has many real-world applications such as removing landmines or surveilling an area. We prove that this problem is inherently difficult to solve in its general case, and we provide an approach that is shown to be probabilistically complete, and that aims at minimizing a cost function (such as energy.) The remainder of the dissertation focuses on minimum-energy exploration, and offers a novel formulation for the problem. The formulation can be directly applied to compare exploration algorithms. In addition, an approach that aims at reducing energy during the exploration process is presented, and is shown through simulation to perform better than existing algorithms

Kecendrungan Penyakit Tidak Menular dan Penelitiannya di Indonesia

Like other developing countries in the South East Asian region Indonesia is undergoing an epidemiological transition. Communicable diseases tend to decrease, while non-communicable diseases and accidents tend to increase. This epidemiologic transition is strongly influenced by demographic and "life style" factors. Risk factors as smoking high calorie and fat diet, mental stress and a sedentary life style will have an important impact on the increase of non-communicable diseases like cancer, heart disease, stroke and diabetes. Cardiovascular diseases are rare before 1960, but started to increase since the 1970\u27s. According to the health household surveys the prevalence of cardiovascular diseases increases from 1.1 per 1000 in 1972 to 5.9 per 1000 in 1980. A 5 year study (1976-1980) of hospital patients in Bali analyzed 1.339 in patients (12% of all inpatients) and found the following distribution : ischemic h.d. 32%, rheumatic h.d. 40%, pulmonic h.d. 18% hypertensive h.d. 4%, congenital h.d. 1% and other h.d. 5%. Community surveys of diabetes, found a prevalence of around 1.5% in adults. The most frequent complications of diabetes were : ischemic heart disease (20-25%), gangrene (2,4%), pulmonary tb (10-13%) and diabetic ketoacidosis (2.5-5%). Cancer incidence is estimated at 100 per 100.000 per year. A pathology based registry in 1988 recorded the following localisations : cervix (25.57%), breast (15.83%), lymphoid (12.52%), skin (11,46%), nasopharynx (7.8%), ovary (6,60%). Rectum (6.04%), connective tissue (5.82%), thyroid (4.43%), colon (3.9%). A study of cancer in 17 hospitals in Jakarta found the following cancers in men : lung liver, nasopharynx, lymphoma, rectum, leukemia, stomach, colon, larynx and pancreas in descending order of frequency. The most frequent cancers in women were located in the cervix, breast, ovary, lung, liver, nasopharynx, rectum, leukemia, lymphglands and colon. Hospital data showed that 60-80% of patients treated in mental hospitals are suffering from schizophrenia.A study of patients seeking treatment from health centres from that around 20% were experiencing psychological or mental problems. Several dental surveys found carries and periodental diseases in 60% of population surveyed. The highest frequency were found in the 35-44 year age group. According to the health household survey in 1980, accidents have caused 3,5% of all deaths. It is estimated that around 2.5 million accidents each year and around 10% of all hospital admissions are caused by accidents. About 40% of all accidents treated in hospitals are caused by traffic accidents, 35% of which are head trauma. Research on non-communicable diseases have to be undertaken to know the magnitude of the problems and develop methodologies to control the diseases, emphasizing behaviour change, environmental improvement and the use of appropriate technology. Diseases which require attention are cancer, cardiovascular diseases, endocrine diseases (diabetes, thyroid diseases, etc), dental and oral diseases, accidents and occupational diseases, mental diseases, neurological diseases, chronic respitory diseases, joint and rheumatic diseases, congenital/hereditary diseases, and diseases caused by radiation

On the semantic development of the deverbal noun formative -mA in early Turkic periods

Türk dilleri sondan eklemeli dillerden oluşan bir dil ailesi olarak yeni sözcük yapımında en eski yazılı kaynaklardan bu yana gözlemlendiği şekilde doğal olarak yapım eklerine başvurmuş ve başvurmaya da devam etmektedir. Buna mukabil sözcük yapımı konusu da hem tarihî hem de çağdaş Türk yazı dillerinde teveccüh görmüş bir konu olmayı sürdürür. Sözcük yapım çalışmalarının odaklandığı en önemli nokta ele alınan türemiş sözcüklerde kök/gövde ve türetimi gerçekleştiren yapım eklerinin birbiriyle tutarlılığı olagelmiştir. Bununla birlikte bir ekle türetilmiş sözcüklerin semantik olarak tasnif edilmeleri ikincil önemde bir konu olarak düşünülmüş olsa gerek ki semantik boyut ya çok kabaca (ör. soyut-somut, ad-sıfat) verilmiş ya da verilen semantik nitelikler çok dağınık şekilde bir arada sunulmuştur. Aynı durum ele alınacak -mA fiilden isim yapım eki için de geçerlidir. Bu bildiride -mA eki özelinde tarihî Türk yazı dillerinde (Eski, Orta ve Yeni Türkçe) söz konusu ekin semantik boyutunun gelişimi tarafımızca önerilen semantik tasnif üzerinde gösterilecek, aynı tasnif çağdaş Kırgız Türkçesi üzerinde uygulanarak tarihî süreç ile çağdaş bir Türk dilindeki durum karşılaştırılacaktır. Bu karşılaştırma neticesinde söz konusu ekin en eski örneklerde hiç görülmeyen “eylemin kavramsal adı” ve “eylemin kılıcısı” olma niteliğinin Orta Türkçeden itibaren ortaya çıkması ve adfiil olma yönü haricinde çağdaş Kırgız Türkçesinde de belirgin şekilde mevcut oluşu gibi bulgular okurla paylaşılacaktır

The Cerebellum’s Relationship to Language Function

The idea that the cerebellum impacts language function and development is currently supported by a small but increasing number of empirical studies. This theory is further strengthened by the recognized cerebellar-ponto-cerebellar connectivity between the left perisylvian cortex and the right cerebellar hemispheres, particularly lateral regions Crus I, Crus II, and VIIb. To study the relationship between tissue volumes of manually parecellated sub-regions of the cerebellum in structural MRI and a variety of receptive and expressive language measures, we looked at 18 typical individuals (aged 9-38 years). This initial data indicated a relationship between expressive language and the volume of lateral cerebellar sub-regions. To create a laterality index across regions, we calculated the volume of cerebellar sub-regions and determined difference= (right- left)/ (right+ left) for the Crus I, Crus II, and VIIb regions. These difference scores were then connected to language outcomes. Our results showed that better expressive language scores on the Clinical Evaluation of Language Fundamentals CELF-expressive; p \u3c .01) were predicted by greater volume of the right VIIb region, and greater volume of the right Crus I region was correlated with worse performance (p\u3c .01). The Crus II difference measure (p\u3e .05) yielded no associations. Though these findings are introductory, they may allow for the development of therapeutic methods for language recovery after cortical insult through better understanding of cerebellar function and its connections to language

Analisis Faktor Keberhasilan Inseminasi Buatan Pada Ternak Sapi Bali di Kecamatan Atambua Selatan Kabupaten Belu

This research was conducted in South Atambua District, Belu Regency for 5 months. The purpose of this study was to determine the success factors of artificial insemination of bali cattle in Atambua Selatan District. In this study using a survey method, data collection was done by interview and observation. The population of acceptors in this study amounted to 50 farmers with 523 cattle. The variables observed in this study were the characteristics of the breeder, the pattern of livestock rearing, the number of livestock ownership, Service Per Conception (S/C), Conception Rate (CR), and Calving Interval (CI). The results showed that the success rate of Artificial Insemination in Atambua Selatan District was based on Service per Conception with an average S/C value of 1.77; The Conception Rate is 48.63% and the Calving interval is 413.20 months. Factors that influence the success rate of Artificial Insemination in Atambua Selatan District based on Service Per Conception, Conception Rate and Calving interval, namely semen quality, inseminator skills, estrus detection and reporting estrus, AI techniques, feed quality and quantity.Penelitian ini dilaksanakan di Kecamatan Atambua Selatan, Kabupaten Belu selama 5 bulan. Tujuan dari penelitian ini adalah untuk mengetahui faktor-faktor keberhasilan Inseminasi Buatan Sapi Bali di Kecamatan Atambua Selatan. Penelitian ini menggunakan metode survey; pengumpulan data dilakukan dengan wawancara dan observasi. Populasi akseptor dalam penelitian ini berjumlah 50 peternak dengan jumlah ternak 523 ekor. Variabel yang diamati dalam penelitian ini adalah karakteristik peternak, pola pemeliharaan ternak, jumlah kepemilikan ternak, Service Per Conception (S/C), Conception Rate (CR), dan Calving Interval (CI). Hasil penelitian menunjukkan bahwa tingkat keberhasilan Inseminasi Buatan di Kecamatan Atambua Selatan berdasarkan Service per Conception dengan nilai S/C rata-rata 1,77, Conception Rate sebesar 48,63%, dan Calving Interval sebesar 413,20 bulan. Faktor-faktor yang mempengaruhi tingkat keberhasilan inseminasi buatan di Kecamatan Atambua Selatan berdasarkan Service Per Conception, Conception Rate, dan Calving Interval terdiri dari kualitas semen, keterampilan inseminator, deteksi birahi dan pelaporan birahi, teknik IB, serta kualitas dan kuantitas pakan

СУЧАСНИЙ СТАН ПІДГОТОВКИ МАЙБУТНЬОГО ВЧИТЕЛЯ ФІЗИКО-МАТЕМАТИЧНИХ ДИСЦИПЛІН ДО ГУРТКОВОЇ РОБОТИ У ЗАКЛАДАХ ОСВІТИ

In the article the reasons for updating the problem of training future teachers of physical and mathematical sciences circle to work in schools. Analyzed dissertation research as well as books and manuals relating to the training of teachers. Found that in modern pedagogical science paid insufficient attention to the preparation of future teachers of physical and mathematical disciplines of circle work.Key words: training future teachers, physical and mathematical disciplines, group, hobby groups work.У статті визначено причини актуалізації проблеми підготовки майбутнього вчителя фізико-математичних дисциплін до гурткової роботи у закладах освіти. Проаналізовано дисертаційні дослідження, а також підручники та навчальні посібники, які торкаються фахової підготовки педагога. Встановлено, що в сучасній педагогічній науці приділяється недостатня увага питанням підготовки майбутніх вчителів фізико-математичних дисциплін до організації гурткової роботи.Ключові слова: підготовка майбутнього вчителя, фізико-математичні дисципліни, гурток, гурткова робота