The first paper dealing with the geology of the Korean Peninsula is & ulcorner; Geologische Skizze von Korea ] written by a German geologist, Carl Christian Gottsche, in 1886. This article delves into the historical background of Gottsche's visit to Korea, his activities in Korea, and evaluation on & ulcorner; Geologische Skizze von Korea ] . During the latter half of 19th Century, the Joseon Dynasty experienced an era of transformation owing to the dissolution of Confucianism -based traditional society, invasions of oriental and occidental powers, and inevitable conflict between conservative and progressive groups. The Joseon Dynasty attempted to improve diplomatic relations and trades with foreign countries and accordingly invited a foreign advisor, Paul M & ouml;llendorff, who played a crucial role in the field of foreign affairs and economic development of the Joseon Dynasty during his tenure. M & ouml;llendorff realized the importance of mining exploration for economic development and subsequently invited Prof. Gottsche of the University of Tokyo for geological survey of the Korean Peninsula. In 1884, Gottsche investigated the Korean Peninsula for five months and published the paper, & ulcorner; Geologische Skizze von Korea ] . Gottsche was not able to understand clearly the nature and geologic ages of rocks of the Korean Peninsula, apparently due to the short period of survey. Nonetheless the paper can be treated to be of great significance in generating for the first time the geologic system and geologic map of the Korean Peninsula.

Redlichia nobilis Walcott, 1905 occurs in the Gurangri Formation of the Mungyeong Group, a lithostratigraphic unit of the Cambrian-Ordovician Joseon Supergroup in the Taebaeksan Basin, South Korea. The R. nobilis Zone of the formation is correlated with the Lungwangmiaoan Stage and the middle part of the Duyunian Stage of North and South China regional chronostratigraphic scheme, respectively. It corresponds to middle Stage 4 of Cambrian Series 2 in international chronostratigraphic chart. R. nobilis, which is regarded as the oldest trilobite in South Korea, is estimated to be 512 to 510.4 million years old. The specimens of R. nobilis are preserved on the bedding plane as deformed due to structural movement occurred in the Mungyeong area. It is observed in the outcrop that the cleavage plane intersects the bedding plane almost at right angle, forming intersection lineation parallel to fold axis. The cleavage plane can be generally defined as the XY plane and the lineation as the Y axis of strain ellipse on the bedding plane, and thus, the bedding plane corresponds to the YZ plane. The strain analysis using Mohr circle was performed to estimate strain ratio of the deformed specimens. Strain ratio (R) of the deformed specimens calculated ranges from 2.18 to 2.20, with the average of 2.19. The value is considered strongly reliable because the strain ratio of a combined strain marker consisting of a deformed specimen and elliptical structure (probably concretion) around the specimen is 2.18, nearly identical to the R values of other deformed specimens. Morphologic restoration of shape and size was conducted under no longitudinal strain along Y axis because structures indicative of stretching or shortening along the lineation are not observed in the outcrop and those indicative of shortening along the Z axis and thickening along the X axis are observed in thin section. The deformed specimens were restored into an undeformed state using a digital graphic software by only applying the R value perpendicular to the lineation for each specimen. R. nobilis, based on its restored morphology, is characterized by having anteriorly diagonal preocular sutures that are about 120% more apart than palpebral sutures, a hypostome that is fused with rostral plate and has two pairs of short spines (one pair along the lateral margin and the other at postero-lateral corner), 15 thoracic segments with a long axial spine on the 11th (from the anterior) segment, and a small sub-elliptical pygidium with three axial rings and sagittal furrow.

Nisusiidae is a rhynchonelliform brachiopod family that was widely distributed in low‐latitude regions during the middle Cambrian (Stage 3 of Series 2 to the Drumian Stage of the Miaolingian Series). Cladistic analysis of 24 nisusiid species including two species from South Korea ( Nisusia paucicostellata and Nisusiidae gen. et sp. indet.) demonstrates that the nisusiids consist of two sister clades (Clade 1 and 2) whose common ancestor was derived from a paraphyletic ‘basal’ group. Non‐spinose taxa are all included in Clade 1, while spinose Nisusia species are found throughout the three groups including Clade 1, indicating paraphyly of Nisusia . The optimized ancestral area(s) are assigned to internal nodes of the taxon area cladogram using both the Fitch algorithm and the DIVALIKE+J model of BioGeoBEARS, and then the relationship between cladogenetic area transition types and palaeogeographical areas is examined using the ‘area‐transition count’ method. Of 10 possible cladogenetic area transitions, which are combinations of range contraction (C), expansion (E), switch (S) and no range change (N), six (CC, CE, CN, EN, NN and NS) are observed in the two optimization results. It is proposed that the nisusiids originated in Laurentia as a strongly spinose form and dispersed into high‐latitude peri‐Gondwana during Stage 3 and then strongly diversified into other areas during Stage 4, and that non‐spinose forms evolved later, mainly in Laurentia. The nisusiid palaeobiogeographical pattern is interpreted to reflect distributional range changes that were probably caused by palaeo‐oceanic currents with the aid of island arcs as stepping stones, and pumice, produced by volcanic activity, as the means of dispersal.

The Permo-Triassic adakitic magmatism in the southern Korean Peninsula preserves important tectonomagmatic records along the East Asian continental margin. In this study, we present SHRIMP/LA–MC–ICPMS U-Pb zircon ages and Hf isotope signature with whole-rock geochemical compositions of the Middle Permian to Middle Triassic granitoid gneiss-granitoid suites and the Middle to Late Triassic plutonic rocks in the southeastern Korean Peninsula. The former yields three age groups of ca. 272–263 Ma, ca. 258–251 Ma and ca. 243–240 Ma, respectively. The latter group yields ca. 237–216 Ma ages, indicating a long term magmatism that lasted from the Middle Permian to late Triassic. The granitoid gneiss-granitoid suites have chemical compositions similar to high silica adakitic rocks, showing high SiO2 (59.55–73.97 wt.%), Na2O (3.55–5.30 wt.%), Sr/Y (30–401), and La/YbN (11–173), and low MgO (0.18–1.82 wt.%), Y (2–14 ppm) and YbN (2–7). These rocks are peraluminous with high Ba and Sr, and show relatively high K2O contents and K2O/Na2O ratios (> 0.7), with positive correlation between La/YbN vs. Sr/Y ratios and high initial Sr ratios. These features reflect different contribution of the slab-derived adakite melts that interacted with peridotitic mantle in the metasomatized mantle wedge and the Middle Paleoproterozoic lower crustal basement of the Yeongnam Massif. On the contrary, the Triassic alkaline magmatism in the Yeongnam Massif is alternatively interpreted either by a tectonic switch to the extension-dominated arc system or by a delamination of an overthickened arc. The results from this study offer important evidence for a common subduction-accretion system existed between the North and South China Cratons and microcontinents between them along margins of the East Asian continental blocks, with different plate interaction in different locations generating distinct magmatic suites.

The Neoproterozoic metasedimentary successions and igneous suites in the central Korean Peninsula provide important insights into the tectonic evolution of East Asia. Here we report detailed detrital zircon U-Pb age data from the Neoproterozoic metasedimentary successions as well as geochemical data on the early Neoproterozoic rift-related plutonic rocks. Our results together with the available data from the central Korean Peninsula, lead to the following inferences. (1) Regional sedimentation in the early Neoproterozoic (ca. 1000-920 Ma) as a result of the late Paleoproterozoic to early Neoproterozoic intracratonic rifting. (2) Arc magmatism in the southern periphery of the central Korean Peninsula in the early Neoproterozoic (ca. 913-895 Ma and ca. 865-770 Ma). (3) Back-arc magmatism in the inland area of the central Korean Peninsula in the early Neoproterozoic (ca. 888-852 Ma). (4) Magmatism and sedimentation in the early Neoproterozoic (ca. 765-720 Ma) due to early Neoproterozoic back-arc and intracratonic rifting. The early-Neoproterozoic geological and tectonic events in the central Korean Peninsula correlate with those in the southeastern part of the North China Craton. The spatial and temporal similarities and discrepancies in the early Neoproterozoic geological records of the Sino-Korean continent mark the tectonic evolution within a continental inland (the southeastern part of the North China Craton) and a continental margin (the central Korean Peninsula).

In order to maximize the utility of future studies of trilobite ontogeny, we propose a set of standard practices that relate to the collection, nomenclature, description, depiction, and interpretation of ontogenetic series inferred from articulated specimens belonging to individual species. In some cases, these suggestions may also apply to ontogenetic studies of other fossilized taxa.

During and shortly after the 2017 Pohang Earthquake (Mw 5.4), sand blows were observed around the epicenter for the first time since the beginning of instrumental seismic recording in South Korea. We carried out field surveys plus satellite and drone imagery analyses, resulting in observation of approximately 600 sand blows on Quaternary sediment cover in this area. Most were observed within 3 km of the epicenter, with the farthest being 15 km away. In order to investigate the ground’s susceptibility to liquefaction, we conducted a trench study of a 30 m-long sand blow in a rice field 1 km from the earthquake epicenter. The physical characteristics of the liquified sediments (grain size, impermeable barriers, saturation, and low overburden pressure) closely matched the optimum ground conditions for liquefaction. Additionally, we found a series of soft sediment deformation structures (SSDSs) within the trench walls, such as load structures and water-escaped structures. The latter were vertically connected to sand blows on the surface, reflecting seismogenic liquefaction involving subsurface deformation during sand blow formation. This genetic linkage suggests that SSDS research would be useful for identifying prehistoric damage-inducing earthquakes (Mw > 5.0) in South Korea because SSDSs have a lower formation threshold and higher preservational potential than geomorphic markers formed by surface ruptures. Thus, future combined studies of Quaternary surface faults and SSDSs are required to provide reliable paleoseismological information in Korea.

Fossilized growth series provide rare glimpses into the development of ancient organisms, illustrating descriptively how size and shape changed through ontogeny. Occasionally fossil preservation is such that it is feasible to test alternative possibilities about how ancient development was regulated. Here we apply inferred developmental parameters pertaining to size, shape, and segmentation in the abundant and well-preserved 429 Myr old trilobite Aulacopleura koninckii that we have investigated previously to reconstruct the post-embryonic ontogeny of this ancient arthropod. Our published morphometric analyses associated with model testing have shown that: specification of the adult number of trunk segments (polymorphic in this species) was determined precociously in ontogeny; that growth regulation was targeted (i.e., compensatory), such that each developmental stage exhibited comparable variance in size and shape; and that growth gradients operating along the main body axis, both during juvenile and adult ontogeny, resulted from a form of growth control based on positional specification. While such developmental features are common among extant organisms, our results represent the oldest evidence for them within Metazoa. Herein, the novel reconstruction of the development of Aulacopleura koninckii permits visualization of patterns of relative and absolute growth and segmentation as never before possible for a fossilized arthropod ontogeny. By conducting morphometric analysis of appropriate data sets it is thus possible to move beyond descriptive ontogenetic studies and to address questions of high interest for evolutionary developmental biology using data from fossils, which can help elucidate both how developmental processes themselves evolve and how they affect the evolution of organismal body patterning. By extending similar analyses to other cases of exceptional preservation of fossilized ontogeny, we can anticipate beginning to realize the research program of "paleo-evo-devo."

The Early to Middle Mesozoic basins, distributed sporadically over the Korean Peninsula, preserve important records of the tectonic history of some of the major orogenic belts in East Asia. Here we present a comprehensive study of the structural, geochemical, geochronological, and paleontological features of a volcano-sedimentary package, belonging to the Oseosan Volcanic Complex of the Early to Middle Mesozoic Chungnam Basin, within the Mesozoic subduction-collision orogen in the southwestern Korean Peninsula. The zircon U-Pb data from rhyolitic volcanic rocks of the complex suggest Early to Middle Jurassic emplacement age of ca. 178-172 Ma, harmonious with plant fossil taxa found from the overlying tuffaceous sedimentary rock. The geochemical data for the rhyolitic volcanic rocks are indicative of volcanic arc setting, implying that the Chungnam Basin has experienced an infra-arc subsidence during the basin-expanding stage by subduction of the Paleo-Pacific (Izanagi) Plate. The Jurassic arc-related Oseosan Volcanic Complex was structurally stacked by the older Late Triassic to Early Jurassic post-collisional basin-fill of the Nampo Group by the Jangsan fault during basin inversion. The Late Jurassic to Early Cretaceous K-feldspar and illite K-Ar ages marked the timing of inversion tectonics, contemporaneous with the magmatic quiescence in the southern Korean Peninsula, likely due to flat lying or low-angle subduction. The basin evolution history preserved in the Mesozoic Chungnam Basin reflects a Mesozoic orogenic cycle from post-collision to subduction in the southwestern Korean Peninsula. This, in turn, provides a better understanding of the spatial and temporal changes in Mesozoic tectonic environments along the East Asian continental margin.

AIMS:This prospective randomized controlled study evaluated the first-line use of a novel remotely monitored implantable loop recorder (ILR) in the initial investigation of unexplained syncope, and compared this to conventional therapy and a dedicated Syncope Clinic (SC).METHODS AND RESULTS:A total of 246 patients (mean age 70.3 years) were randomly allocated to conventional management, SC alone, ILR alone, or SC + ILR. Median follow-up was 20 months (IQR 15-25 months). Time to electrocardiogram (ECG) diagnosis was significantly shorter with ILR alone vs. conventional [hazard ratio (HR) 35.5, P = 0.0004] and with SC vs. conventional (HR 25.6, P = 0.002). Seventy-four per cent of first syncopal events documented in the SC groups occurred during provocative tilt testing. Twenty-two per cent of patients who received an ILR were found to have a bradycardia indication for permanent pacing, compared with 3% of patients who did not. Overall, more investigative tests were undertaken in the conventional group than in any other. Only patients who received an ILR had a significant increase in time to second syncope (P = 0.02), suggesting successful diagnosis and management of treatable causes of syncope.CONCLUSIONS:Implantable loop recorder monitoring achieved a more rapid diagnosis in unexplained syncope than usual care. Conventional management of syncope failed to achieve an ECG diagnosis despite a large number of investigative tests. Syncope Clinic and provocative tilt testing delivered a rapid ECG diagnosis, but did not prevent recurrent syncope. Implantable loop recorders offered rapid diagnosis, increased the likelihood of syncope being reported, demonstrated a high rate of intermittent bradycardia requiring pacing, and reduced recurrent syncope.

In Korea,trilobites are among the most intensively studied fossil groups in the past century and provide invaluable information about lower Paleozoic stratigraphy,paleogeography,and tectonics of the Korean Peninsula. Trilobites occur in the lower Paleozoic Joseon Supergroup of the Taebaeksan Basin which was part of the Sino-Korean Craton in the Paleozoic. The Joseon Supergroup is divided into the Taebaek,Yeongwol,and Mungyeong groups. The Taebaek and Yeongwol groups are richly fossiliferous,while the Mungyeong Group is poorly fossiliferous. Contrasting trilobite faunal contents of the Taebaek and Yeongwol groups resulted in two separate biostratigraphic schemes for the Cambrian–Ordovician of the Taebaeksan Basin. A total of 22 biozones or fossiliferous horizons were recognized in the Taebaek Group; 19 zones were established in the Yeongwol Group; and four biozones were known from the Mungyeong Group. These trilobite biozones of the Taebaeksan Basin indicate the Joseon Supergroup ranges in age from the Cambrian Series 2 to Middle Ordovician and can be correlated well with the formations of North China,South China,and Australia.

Recent morphometric analysis revealed a juvenile (meraspid) axial growth gradient in the trunk of the similar to 429 Myr old trilobite Aulacopleura koninckii that resulted from growth control based on positional specification, as is common among extant organisms. Here we explore axial growth gradients in the more anterior body region, the cephalon, and in the cephalon and trunk during subsequent development in the holaspid period. We detected an axial growth gradient in the cephalon in the meraspid period, flatter and opposite in direction to that of the trunk, which also persisted during the holaspid period. We also found an holaspid trunk growth gradient, with a different distribution of growth rates among segments than that of the meraspid period. These newly observed growth gradients are compatible with the mechanism of growth control inferred for the meraspid trunk. Thus, the same kind of growth control may have operated in both body regions and during the whole ontogeny of A. koninckii. This study, along with others on the same species that preceded it, show that morphometric analysis of appropriate data sets can address questions of high interest for evolutionary developmental biology using data from fossils. By revealing developmental features at deep nodes of the phylogenetic tree, these studies will elucidate both how developmental processes evolved and how they themselves affected the evolution of organismal body patterning.

The twiddler syndrome results in retraction and coiling of the lead in the pacemaker pocket with subsequent pacemaker malfunction. If the lead׳s parameters are not affected, then the problem can be corrected by lead repositioning. We describe the first reported case of a dramatic pacemaker lead coiling with a double level of lead compromise, with one of them being intra-cardiac. This condition affected our treatment strategy, as the repositioning of the lead was unfeasible.

We present a case of concurrent subcutaneous ICD implantation in combination with a epicardial pacemaker in a patient with endocarditis and triple valve replacement. Judicious pre-planning of the surgery ensured no damage to the epicardial lead or interaction/ inteference between the leads of the 2 devices.

This paper reports the successive occurrence of Ptychagnostus sinicus Lu, 1957 and Ptychagnostus atavus (Tullberg, 1880) from the lower part of the Machari Formation, Yeongwol Group, Korea. Morphometric approaches of using the landmark and principal component analyses make it possible to differentiate P . sinicus from P . atavus with clarity: pygidia of P . sinicus have a relatively narrow M1, a transverse F2, and a weakly developed M2 tubercle, whereas those of P . atavus are characterized by a broadly arching M1, a chevron-shaped F2, and a prominent M2 tubercle. Recognition of P . atavus , for the first time in Korea, allows the determination of the base of the Drumian Stage in Korea and aids correlation with other parts of the world.

Journal of Cardiovascular ElectrophysiologyVolume 27, Issue 1 p. 131-133 Arrhythmia Rounds Consistent Inconsistency? Is There Pacemaker Malfunction? PAUL S.G. HONG M.R.C.P., PAUL S.G. HONG M.R.C.P. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaSearch for more papers by this authorGUY AMIT M.D., M.P.H., GUY AMIT M.D., M.P.H. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaSearch for more papers by this authorJEFF S. HEALEY M.D., F.H.R.S., JEFF S. HEALEY M.D., F.H.R.S. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaSearch for more papers by this authorSYAMKUMAR DIVAKARA MENON M.D., Corresponding Author SYAMKUMAR DIVAKARA MENON M.D. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaAddress for correspondence: S. Divakara Menon, HGH McMaster Clinic #518, 237 Barton Street East, Hamilton, Ontario, Canada. Fax: 19055771447; E-mail: [email protected]Search for more papers by this author PAUL S.G. HONG M.R.C.P., PAUL S.G. HONG M.R.C.P. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaSearch for more papers by this authorGUY AMIT M.D., M.P.H., GUY AMIT M.D., M.P.H. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaSearch for more papers by this authorJEFF S. HEALEY M.D., F.H.R.S., JEFF S. HEALEY M.D., F.H.R.S. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaSearch for more papers by this authorSYAMKUMAR DIVAKARA MENON M.D., Corresponding Author SYAMKUMAR DIVAKARA MENON M.D. Arrhythmia Services, Division of Cardiology, McMaster University and Hamilton Health Sciences, Hamilton, Ontario, CanadaAddress for correspondence: S. Divakara Menon, HGH McMaster Clinic #518, 237 Barton Street East, Hamilton, Ontario, Canada. Fax: 19055771447; E-mail: [email protected]Search for more papers by this author First published: 17 July 2015 https://doi.org/10.1111/jce.12757 Paul S.G. Hong is partially funded by the Dowager Countess Eleanor Peel Trust (Peel and Rothwell Jackson Travelling Fellowship), United Kingdom. Other authors: No disclosures. Read the full textAboutPDF ToolsRequest permissionExport citationAdd to favoritesTrack citation ShareShare Give accessShare full text accessShare full-text accessPlease review our Terms and Conditions of Use and check box below to share full-text version of article.I have read and accept the Wiley Online Library Terms and Conditions of UseShareable LinkUse the link below to share a full-text version of this article with your friends and colleagues. Learn more.Copy URL No abstract is available for this article. References 1Furman S, Reicher Reiss H, Escher DJW: Atrioventricular sequential pacing and pacemakers. Chest 1973; 63: 783- 789. 2Hayes DL, Friedman PA: Pacemaker and cardiac resynchronisation timing cycles and electrocardiography. Cardiac Pacing, Defibrillation and Resynchronization: A Clinical Approach, 2nd ed. NJ: Wiley-Blackwell; 2011. Volume27, Issue1January 2016Pages 131-133 ReferencesRelatedInformation