An investigation of the properties of cardiac muscle and purkinje tissue

Although it is nearly 70 years since ':'Taller (1887) first recorded the human electrocardiogram, there is still a divergence of opinion among various workers as to the genesis of the electrocardiogram. It is generally agreed, however, that one of the principal factors involved is the order in which the various parts of the heart are excited. The finer details of the manner in which-the excitation wave spreads both in the auricles and in the ventricles are still not clear and therefore various assumptions have had to be made in regard to this for the analysis of the electrocardiogram.The purpose of this study was to investigate certain aspects of the spread of excitation in cardiac tissues as it relates to the genesis of the electrocardiogram. This entailed an investigation of some fundamental properties of these tissues. In Part I of the thesis, observations on the monophasic action potentials from different species of mammalian hearts, recorded by means of a Ling -Gerard intra- cellular microelectrode are described. This part is in general a correlative study of the monophasic action potential and the electrocardiogram obtained from the same animal.Structurally, the heart is complex in that (1) it is a syncytium, (2) there are several muscle bands running in different directions which form the walls of the atria and the ventricles and (3) a specialised conducting tissue is widely distributed in the ventricular walls and sometimes in the atria. An investigation of the spread of - 2 - excitation in the heart would have to take into account these structural characteristics of the pathway. ,Part II describes observations on the structural aspects of the subject.It is also difficult to really understand the spread of excitation in the heart until some knowledge has been ob- tained about the rate of conduction in the various cell types making up the excitable tissues of the cardiac musculature. As will be clear from the review in Part III, this property has never been studied adequately. Particular attention has therefore been paid to this aspect of the subject in the present study and this investigation is described in Part III.Various theories of the genesis of the electrocardio- gram have been advanced as our knowledge of the manner of spread of excitation in the heart has increased. The de- velopment of ideas regarding the spread of excitation in the mammalian heart has provided a general background to the present studies and it has therefore been briefly reviewed. ThÈ. literature on the subject is so extensive that to give a complete review is neither possible nor relevant to the present study. Only those papers which in one tray or other relate to the observations made in this investigation have been included in the survey. Early work has been reviewed by Gaskell, (1900), Erlanger, (1913) and by Davies & Francis, (19)66). The literature on the genesis of the electro- cardiogram has been extensively reviewed by Katz, (1928, 1947)

A Western-Fed Diet Increases Plasma HDL and LDL-Cholesterol Levels in ApoD–/– Mice

Objective Plasma apolipoprotein (apo)D, a ubiquitously expressed protein that binds small hydrophobic ligands, is found mainly on HDL particles. According to studies of human genetics and lipid disorders, plasma apoD levels positively correlate with HDL-cholesterol and apoAI levels. Thus, we tested the hypothesis that apoD was a regulator of HDL metabolism. Methods & Results We compared the plasma lipid and lipoprotein profiles of wild-type (WT) C57BL/6 mice with apoD−/− mice on a C57BL/6 background after receiving a high fat-high cholesterol diet for 12 weeks. ApoD−/− mice had higher HDL-cholesterol levels (61±13-apoD−/− vs. 52±10-WT-males; 37±11-apoD−/− vs. 22±2 WT-female) than WT mice with sex-specific changes in total plasma levels of cholesterol and other lipids. Compared to WT, the HDL of apoD−/− mice showed an increase in large, lipid-rich HDL particles and according to size various quantities and sizes of LDL particles. Plasma levels of lecithin:cholesterol acyltransferase in the control and apoD−/− mice were not different, however, plasma phospholipid transfer protein activity was modestly elevated (+10%) only in male apoD−/− mice. An in vivo HDL metabolism experiment with isolated Western-fed apoD−/− HDL particles showed that female apoD−/− mice had a 36% decrease in the fractional catabolic rate of HDL cholesteryl ester. Hepatic SR-BI and LDLR protein levels were significantly decreased; accordingly, LDL-cholesterol and apoB levels were increased in female mice. Conclusion In the context of a high fat-high cholesterol diet, apoD deficiency in female mice is associated with increases in both plasma HDL and LDL-cholesterol levels, reflecting changes in expression of SR-BI and LDL receptors, which may impact diet-induced atherosclerosis

Analisis Pendayagunaan Tenaga Sarjana Kesehatan Masyarakat di Rumah Sakit Umum Pusat Dokter Kariadi Kota Semarang Tahun 2013

Pendayagunaan tenaga kesehatan adalah upaya pemerataan dan pemanfaatan serta pengembangan tenaga kesehatan.Pendayagunaan tenaga kesehatan, utamanya dalam rangka pemerataan tenaga kesehatan dilaksanakan sesuai dengan rencana kebutuhan tenaga kesehatan.RSUP Dokter Kariadi adalah rumah sakit pusat yang memiliki banyak tenaga kerja, salah satunya SKM.Kariadi harus mendayagunakan tenaganya untuk mendapatkan hasil kinerja yang optimal. Namun, terdapat kesenjangan antara uraian tugas dengan kompetensi SKM, sehingga perlu adanya pendayagunaan tenaga SKM. Tujuan pendayagunaan SKM adalah mengoptimalkan kinerja SKM agar uraian tugasdengan kompetensinya sesuai. Tujuan penelitian adalah menganalisis pendayagunaan tenaga SKM di RSUP Dokter Kariadi Kota Semarang yaitu variabelpenataan struktur organisasi, analisis jabatan, uraian tugas, persyaratan jabatan, standar kompetensi dan pendayagunaan tenaga SKM. Penelitian ini merupakan penelitian observasional. Jenis Penelitian yang dilakukan merupakan penelitian kualitatif dengan pendekatan deskriptif. Populasi yang diteliti adalah 4 informan utama terdiri dari Kepala Sumber Daya Manusia dan 3 tenaga SKM serta 1 informan triangulasi Direktur SDM dan Pendidikan. Hasil penelitian menunjukkan bahwa dalam penempatan SKM masihdi dasari pada kebutuhan belum disesuaikan dengan kompetensinya sehingga terjadi ketidaksesuaian uraian tugas dengan kemampuannya.Saran yang direkomendasikan yaitu: Pendayagunaan tenaga SKM harus menyesuaikan antara analisis jabatan, yang meliputi syaratjabatan, uraian tugas, kemudian harus menyesuaikan dengan kompetensi sehingga tidak terjadi kesenjanga

Mechanical rejuvenation and over-aging in the soft glassy rheology model

Mechanical rejuvenation and over-aging of glasses is investigated through stochastic simulations of the soft glassy rheology (SGR) model. Strain- and stress-controlled deformation cycles for a wide range of loading conditions are analyzed and compared to molecular dynamics simulations of a model polymer glass. Results indicate that deformation causes predominantly rejuvenation, whereas over-aging occurs only at very low temperature, small strains, and for high initial energy states. Although the creep compliance in the SGR model exhibits full aging independent of applied load, large stresses in the nonlinear creep regime cause configurational changes leading to rejuvenation of the relaxation time spectrum probed after a stress cycle. During recovery, however, the rejuvenated state rapidly returns to the original aging trajectory due to collective relaxations of the internal strain.Comment: 8 pages, 9 figure

The Political Economy of Myanmar's Transition

This is an Author's Original Manuscript of an article whose final and definitive form, the Version of Record, has been published in the JOURNAL OF CONTEMPORARY ASIA, 07 Feb 2013, copyright Taylor & Francis, available online at: http://www.tandfonline.com/10.1080/00472336.2013.764143.Since holding elections in 2010, Myanmar has transitioned from a direct military dictatorship to a formally democratic system and has embarked on a period of rapid economic reform. After two decades of military rule, the pace of change has startled almost everyone and led to a great deal of cautious optimism. To make sense of the transition and assess the case for optimism, this article explores the political economy of Myanmar's dual transition from state socialism to capitalism and from dictatorship to democracy. It analyses changes within Myanmar society from a critical political economy perspective in order to both situate these developments within broader regional trends and to evaluate the country's current trajectory. In particular, the emergence of state-mediated capitalism and politico-business complexes in Myanmar's borderlands are emphasised. These dynamics, which have empowered a narrow oligarchy, are less likely to be undone by the reform process than to fundamentally shape the contours of reform. Consequently, Myanmar's future may not be unlike those of other Southeast Asian states that have experienced similar developmental trajectories

Updated Parkinson’s Disease Motor Subtypes Classification and Correlation to Cerebrospinal Homovanillic Acid and 5-Hydroxyindoleacetic Acid Levels

INTRODUCTION: Motor classifications of Parkinson\u27s Disease (PD) have been widely used. This paper aims to update a subtype classification using the MDS-UPDRS-III and determine if cerebrospinal neurotransmitter profiles (HVA and 5-HIAA) differ between these subtypes in a cohort from the Parkinson\u27s Progression Marker Initiative (PPMI). METHODS: UPDRS and MDS-UPDRS scores were collected for 20 PD patients. Akinetic-rigid (AR), Tremor-dominant (TD), and Mixed (MX) subtypes were calculated using a formula derived from UPDRS, and a new ratio was developed for subtyping patients with the MDS-UPDRS. This new formula was subsequently applied to 95 PD patients from the PPMI dataset, and subtyping was correlated to neurotransmitter levels. Data were analyzed using receiver operating characteristic models and ANOVA. RESULTS: Compared to previous UPDRS classifications, the new MDS-UPDRS TD/AR ratios produced significant areas under the curve (AUC) for each subtype. The optimal sensitivity and specificity cutoff scores were ≥0.82 for TD, ≤0.71 for AR, and \u3e0.71 and CONCLUSIONS: This MDS-UPDRS motor classification system provides a method to transition from the original UPDRS to the new MDS-UPDRS. It is a reliable and quantifiable subtyping tool for monitoring disease progression. The TD subtype is associated with lower motor scores and higher HVA levels, while the AR subtype is associated with higher motor scores and lower 5-HIAA levels

A Study of the Relationship Between Uric Acid and Substantia Nigra Brain Connectivity in Patients With REM Sleep Behavior Disorder and Parkinson’s Disease

Low levels of the natural antioxidant uric acid (UA) and the presence of REM sleep behavior disorder (RBD) are both associated with an increased likelihood of developing Parkinson’s disease (PD). RBD and PD are also accompanied by basal ganglia dysfunction including decreased nigrostriatal and nigrocortical resting state functional connectivity. Despite these independent findings, the relationship between UA and substantia nigra (SN) functional connectivity remains unknown. In the present study, voxelwise analysis of covariance was used in a cross-sectional design to explore the relationship between UA and whole-brain SN functional connectivity using the eyes-open resting state fMRI method in controls without RBD, patients with idiopathic RBD, and PD patients with and without RBD. The results showed that controls exhibited a positive relationship between UA and SN functional connectivity with left lingual gyrus. The positive relationship was reduced in patients with RBD and PD with RBD, and the relationship was found to be negative in PD patients. These results are the first to show differential relationships between UA and SN functional connectivity among controls, prodromal, and diagnosed PD patients in a ventral occipital region previously documented to be metabolically and structurally altered in RBD and PD. More investigation, including replication in longitudinal designs with larger samples, is needed to understand the pathophysiological significance of these changes

Exploring 4D Quantum Hall Physics with a 2D Topological Charge Pump

The discovery of topological states of matter has profoundly augmented our understanding of phase transitions in physical systems. Instead of local order parameters, topological phases are described by global topological invariants and are therefore robust against perturbations. A prominent example thereof is the two-dimensional integer quantum Hall effect. It is characterized by the first Chern number which manifests in the quantized Hall response induced by an external electric field. Generalizing the quantum Hall effect to four-dimensional systems leads to the appearance of a novel non-linear Hall response that is quantized as well, but described by a 4D topological invariant - the second Chern number. Here, we report on the first observation of a bulk response with intrinsic 4D topology and the measurement of the associated second Chern number. By implementing a 2D topological charge pump with ultracold bosonic atoms in an angled optical superlattice, we realize a dynamical version of the 4D integer quantum Hall effect. Using a small atom cloud as a local probe, we fully characterize the non-linear response of the system by in-situ imaging and site-resolved band mapping. Our findings pave the way to experimentally probe higher-dimensional quantum Hall systems, where new topological phases with exotic excitations are predicted