Finding a suitable system scale to optimize program performance on software DSM systems

Recently, software distributed shared memory systems have successfully provided an easy user interface to parallel user applications on distributed systems. In order to prompt program performance, most of DSM systems usually were greedy to utilize all of available processors in a computer network to execute user programs. However, using more processors to execute programs cannot necessarily guarantee to obtain better program performance. The overhead of paralleling programs is increased by the addition in the number of processors used for program execution. If the performance gain from program parallel cannot compensate for the overhead, increasing the number of execution processors will result in performance degradation and resource waste. In this paper, we proposed a mechanism to dynamically find a suitable system scale to optimize performance for DSM applications according to run-time information. The experimental results show that the proposed mechanism can precisely predict the processor number that will result in the best performance and then effectively optimize the performance of the test applications by adapting system scale according to the predicted result. Yi-Chang Zhuang received his B.S., M.S. and Ph.D. degrees in electrical engineering from National Cheng Kung University in 1995, 1997, and 2004. He is currently working as an engineer at Industrial Technology Research Institute in Taiwan. His research interests include object-based storage, file systems, distributed systems, and grid computing. Jyh-Biau Chang is currently an assistant professor at the Information Management Department of Leader University in Taiwan. He received his B.S., M.S. and Ph.D. degrees from Electrical Engineering Department of National Cheng Kung University in 1994, 1996, and 2005. His research interest is focused on cluster and grid computing, parallel and distributed system, and operating system. Tyng-Yeu Liang is currently an assistant professor who teaches and studies at Department of Electrical Engineering, National Kaohsiung University of Applied Sciences in Taiwan. He received his B.S., M.S. and Ph.D. degrees from National Cheng Kung University in 1992, 1994, and 2000. His study is interested in cluster and grid computing, image processing and multimedia. Ce-Kuen Shieh currently is a professor at the Electrical Engineering Department of National Cheng Kung University in Taiwan. He is also the chief of computation center at National Cheng Kung University. He received his Ph.D. degree from the Department of Electrical Engineering of National Cheng Kung University in 1988. He was the chairman of the Electrical Engineering Department of National Cheng Kung University from 2002 to 2005. His research interest is focused on computer network, and parallel and distributed system. Laurence T. Yang is a professor at the Department of Computer Science, St. Francis Xavier University, Canada. His research includes high performance computing and networking, embedded systems, ubiquitous/pervasive computing and intelligence, and autonomic and trusted computing.     

The characterization of restriction endonucleases: the work of Hamilton Smith

Purification of the HhaII Restriction Endonuclease from an Overproducer Escherichia coli Clone(Kelly, S., Kaddurah-Daouk, R., and Smith, H. O. (1985) J. Biol. Chem. 260, 15339–15344)Catalytic Properties of the HhaII Restriction Endonuclease(Kaddurah-Daouk, R., Cho, P., and Smith, H. O. (1985) J. Biol. Chem. 260, 15345–15351)Hamilton Othanel Smith was born in 1931 in New York City. In 1937, he and his family moved to Champaign-Urbana, Illinois, because his father had joined the faculty of the department of education at the University of Illinois. As a boy, Smith was interested in chemistry, electricity, and electronics, and he spent many hours with his brother in their basement laboratory, which was stocked with supplies purchased from their paper route earnings. Smith attended a small college preparatory school called the University Laboratory High School and graduated in 3 years largely due to his science teacher who allowed him to complete chemistry and physics during the summer.Open in a separate windowHamilton O. SmithAfter finishing high school, Smith enrolled at the University of Illinois, majoring in mathematics. During his sophomore year, his brother showed him a book on mathematical modeling of central nervous system circuits by Nicolas Rashevsky. This caught his interest, and after transferring to the University of California, Berkeley, Smith immersed himself in courses in cell physiology, biochemistry, and biology. A guest lecture by Journal of Biological Chemistry (JBC) Classic author George Wald (1) describing his studies of retinal biochemistry soon converted Smith into a devoted student of visual physiology and eventually motivated him to apply to medical school.In 1952, Smith began his studies at the Johns Hopkins University Medical School. He received his M.D. 4 years later and went to Barnes Hospital in St. Louis for a medical internship. However, in 1957, Smith was called up in the Doctor Draft and joined the U.S. Navy. He finished his Navy service in 1959 and moved to Detroit to begin a medical residency training at the Henry Ford Hospital. There he became interested in bacteriophage and decided that this would be the focus of his research.So, in 1962, Smith began his research career with Myron Levine in the department of human genetics at the University of Michigan in Ann Arbor. He and Levine carried out a series of studies demonstrating the sequential action of the phage P22 C-genes, which controlled lysogenization. They also discovered the gene controlling prophage attachment, now known as the int gene, and carried out a study of defective transducing particles formed after induction of int mutant prophage.In 1967, Smith joined the faculty of Johns Hopkins University as an assistant professor of microbiology and continued his bacteriophage research. A year later, working with Thomas J. Kelly, Jr. and Kent W. Wilcox, Smith isolated and characterized the first Type II restriction endonuclease (HindII) from Haemophilus influenzae and determined the sequence of its cleavage site (2, 3). In recognition of this discovery, he was awarded the 1978 Nobel Prize in Physiology or Medicine with Werner Arber and Daniel Nathans.These studies led to Smith''s subsequent research on DNA methylases and nucleases in H. influenzae. The two JBC Classics reprinted here detail Smith''s efforts to discover the rules governing sequence recognition in the Type II restriction endonuclease HhaII via x-ray crystallography. To facilitate these studies, Smith and his colleagues engineered a two-plasmid system in Escherichia coli that overproduced HhaII on induction with isopropylthiogalactoside (IPTG). The first paper describes the induction characteristics of the two-plasmid overproducer clone and purification of the endonuclease. The second paper, published back-to-back with the first, details the catalytic properties of the endonuclease. Smith used two methods to follow the reactions: 1) gel electrophoretic analysis of nicked circular and linear DNA products, and 2) release of ³²P-labeled inorganic phosphate from specifically labeled HhaII sites in a reaction coupled with bacterial alkaline phosphatase. Smith''s two-plasmid system eventually allowed him to obtain crystals of the HhaII endonuclease with a heptanucleotide DNA duplex (4).Smith served on the faculty at Johns Hopkins for 30 years before retiring as American Cancer Society Distinguished Research Professor Emeritus of Molecular Biology and Genetics in 1998. In 1993, he accepted an appointment to the scientific advisory council of The Institute for Genomic Research, which led to his collaboration with J. Craig Venter in the sequencing of H. influenzae by whole genome shotgun sequencing and assembly. Five years later, Smith joined Celera Genomics, where he was senior director of DNA Resources and aided in the sequencing of the Drosophila and human genomes. In 2005, he co-founded Synthetic Genomics, an off-shoot of Celera. He also serves as scientific director of the Synthetic Biology & Biological Energy Groups at the J. Craig Venter Institute. In addition to the Nobel Prize, Smith has received several honors including election to the National Academy of Sciences in 1980.¹     

Robert Alexander Falla K.B.E., C.M.G., M.A., D.Sc., F.R.S.N.Z.

Abstract

On 23 February 1979 Sir Robert Falla collapsed and died at his home in Eastbourne. He was 77. His sudden death came as a great shock to his multitude of friends and colleagues, many of whom were still sharing with Sir Robert a deep sense of loss at the death on 31 May 1978, shortly after the couple's golden wedding anniversary, of his charming wife Molly.     

Mebendazole Monotherapy and Long-Term Disease Control in Metastatic Adrenocortical Carcinoma

ObjectiveTo describe successful long-term tumor control in metastatic adrenocortical carcinoma, a relatively rare tumor with limited treatment options outside of surgery.MethodsWe present the clinical, radiologic, and pathologic findings in a patient with failure of or intolerance to conventional treatments for metastatic adrenocortical carcinoma.ResultsA 48-year-old man with adrenocortical carcinoma had disease progression with systemic therapies including mitotane, 5-fluorouracil, streptozotocin, bevacizumab, and external beam radiation therapy. Treatment with all chemotherapeutic drugs was ceased, and he was prescribed mebendazole, 100 mg twice daily, as a single agent. His metastases initially regressed and subsequently remained stable. While receiving mebendazole as a sole treatment for 19 months, his disease remained stable. He did not experience any clinically significant adverse effects, and his quality of life was satisfactory. His disease subsequently progressed after 24 months of mebendazole monotherapy.ConclusionMebendazole may achieve long-term disease control of metastatic adrenocortical carcinoma. It is well tolerated and the associated adverse effects are minor. (Endocr Pract. 2011;17:e59-e62)     

Linnaeus as an Economic Botanist

Summary

The interest of Carl Linnaeus (1707–1778) in the uses of plants as manifested in his travel books and dissertations was much influenced by the urge of his country, war-impoverished Sweden, for national recovery and self-sufficiency. His official Swedish journeys of 1741–1749 were primarily economic surveys, giving much attention to locally used dye-plants. The dissertation Pan Suecicus (1749) details experimental feeding of cattle, pigs, sheep and goats with native Swedish plants: it also represents an important stage in the development of the Linnaean binomial method for naming species.     

On Building Parallel &; Grid Applications: Component Technology and Distributed Services

Software Component Frameworks are well known in the commercial business application world and now this technology is being explored with great interest as a way to build large-scale scientific applications on parallel computers. In the case of Grid systems, the current architectural model is based on the emerging web services framework. In this paper we describe progress that has been made on the Common Component Architecture model (CCA) and discuss its success and limitations when applied to problems in Grid computing. Our primary conclusion is that a component model fits very well with a services-oriented Grid, but the model of composition must allow for a very dynamic (both in space and in time) control of composition. We note that this adds a new dimension to conventional service workflow and it extends the “Inversion of Control” aspects of most component systems. Dennis Gannon is a professor of Computer Science at Indiana University. He received his Ph.D. in Computer Science from the University of Illinois in 1980 and his Ph.D. in Mathematics from the University of California in 1974. From 1980 to 1985, he was on the faculty at Purdue University. His research interests include software tools for high performance distributed systems and problem solving environments for scientific computation. Sriram Krishnan received his Ph.D. in Computer Science from Indiana University in 2004. He is currently in the Grid Development Group at the San Diego Supercomputer Center where he is working on designing a Web services based architecture for biomedical applications that is secure and scalable, and is conducive to the creation of complex workflows. He received my undergraduate degree in Computer Engineering from the University of Mumbai, India. Liang Fang is a Ph.D. student in Computer Science at Indiana University. His research interests include Grid computing, Web services, portals, their security and scalability issues. He is a Research Assistant in Computer Science at Indiana University, currently responsible for investigating authorization and other security solutions to the project of Linked Environments for Atmospheric Discovery (LEAD). Gopi Kandaswamy is a Ph.D. student in the Computer Science Department at Indiana University where he is current a Research Assistant. His research interests include Web services and workflow systems for the Grid. Yogesh Simmhan received his B.E. degree in Computer Science from Madras University, India in 2000, and is a doctoral candidate in Computer Science at Indiana University. He is currently working as a Research Assistant at Indiana University, investigating data management issues in the LEAD project. His interests lie in data provenance for workflow systems and its use in data quality estimation. Aleksander Slominski is a Ph.D. student in the Computer Science at Indiana University. His research interests include Grid and Web Services, streaming XML Pull Parsing and performance, Grid security, asynchronous messaging, events, and notifications brokers, component technologies, and workflow composition. He is currently working as a Research Assistant investigating creation and execution of dynamic workflows using Grid Process Execution Language (GPEL) based on WS-BPEL.     

Le dossier Vavilov

Vavilov’s dossier. Gould revived the memory of N.I. Vavilov, a victim of the Stalinian system and misjudged among occidental evolutionists. His contribution is impressive in applied research (phytogeography, his list of world-wide plant resources, a unique collection of germplasms intact and always available) as well as in theoretical research work on artificial selection, immunitary relationships between parasite and plant, the bases of his Law of homologous series in hereditary variations, and centers of origin of cultivated plants. Darwinian concept of natural selection were essential for him, but he considered that the evolutionary changes were not only produced by random variations, but by preset channels, recognising the internal constraints of heredity. His heritage has always been maintained in his Institutes. His Evolutionary theories are now confirmed by molecular genetics and systematics. S.J. Gould was the first to revive Vavilov’s memory and scientific importance. During his studies on the gastropod Cerion Gould recognised the balance between external and internal constraints in Evolution. To cite this article: M. Debrenne, F. Debrenne, C. R. Palevol 2 (2003).     

Spatial patterns of Smith fir alpine treelines on the south-eastern Tibetan Plateau support that contingent local conditions drive recent treeline patterns

Background: Recent work has shown little change in the position of the Smith fir treeline on the south-eastern Tibetan Plateau in response to global warming. However, the relationship between tree distribution patterns within the treeline ecotone and low responsiveness is unknown, and additional constraints than climate might be major drivers of these patterns (e.g. microsite availability for regeneration).

Aims: To characterise the spatial patterns of Smith fir alpine treelines and to infer the underlying processes driving their dynamics.

Methods: We investigated spatial patterns of Smith fir trees across two treeline ecotones in the Sygera Mountains, south-eastern Tibetan Plateau. The O(r)-ring statistic was used to analyse the univariate and bivariate spatial point patterns of three size classes (adults, juveniles and seedlings).

Results: Mature trees presented random spatial patterns. Clusters of juveniles and seedlings colonised areas not occupied by mature trees. Seedlings were clustered and established preferentially near juvenile firs, Rhododendron mats and over moss–lichen and organic matter substrates, indicating the importance of microsite availability for successful Smith fir recruitment.

Conclusions: Local factors such as microsite availability may play a major role in driving recent Smith fir treeline patterns and determine the lack of significant warming-induced upward shifts of these ecotones.     

The Art Collector

Abstract

The initiating point of this paper was an article in AEPR by Peter J. Smith in March/April 2003. At the end of the article, Peter J. Smith provides a short answer.     

Studying effects of different protonation states of His11 and His102 in ribose-5-phosphate isomerase of Trypanosoma cruzi: an example of cooperative behavior

Abstract

The Trypanosoma cruzi ribose-5-phosphate isomerase B (TcRpiB) is a crucial piece in the pentose phosphate pathway and thus is a potential drug target for treatment of Chagas’ disease. TcRpiB residues, such as Cys69, Asp45, Glu149 and Pro47, have confirmed their roles in substrate recognition, catalytic reaction and binding site conformation. However, the joint performance of His11 and His102, in the D-ribose-5-phosphate (R5P) in the catalysis is not well understood. In this work, we probed the influence of different protonation states of His11 and His102 on the behavior of the ligand R5P using molecular dynamics simulations, network analysis and thermodynamic integration. Simulations revealed that a protonated His11 combined with a neutral His102 (His11⁺?His102) was able to stabilize the ligand R5P in the binding site. Moreover, calculated relative free energy differences showed that when protonated His11 was coupled to a neutral His102 an exergonic process takes place. On the other hand, neutral His11 combined with a protonated His102 (His11?His102⁺), sampled conformations that resembled the catalyzed product D-ribulose-5-phosphate (Ru5P). Network analysis also demonstrated some peculiarities for these systems with some negatively correlated nodes in the binding site for His11?His102⁺, and exclusive suboptimal paths for His11⁺?His102. Therefore, the combined approach presented in this paper proposes two suitable protonation states for the TcRpiB catalytic mechanism, where an extra proton in either histidines might favor R5P binding or influence isomerization reaction to Ru5P. Our results may guide further in silico drug discovery studies.

Communicated by Ramaswamy H. Sarma     

Finding Hamiltonian paths in tournaments on clusters

This paper presents a general methodology for the communication-efficient parallelization of graph algorithms using the divide-and-conquer approach and shows that this class of problems can be solved in cluster environments with good communication efficiency. Specifically, the first practical parallel algorithm, based on a general coarse-grained model, for finding Hamiltonian paths in tournaments is presented. On any such parallel machines, this algorithm uses only (3log p+1), where p is the number of processors, communication rounds, which is independent of the tournament size, and can reuse the existing linear-time algorithm in the sequential setting. For theoretical completeness, the algorithm is revised for fine-grained models, where the ratio of computation and communication throughputs is low or the local memory size, , of each individual processor is extremely limited for any , solving the problem with O(log p) communication rounds, while the hidden constant grows with the scalability factor 1/∊. Experiments have been carried out on a Linux cluster of 32 Sun Ultra5 computers and an SGI Origin 2000 with 32 R10000 processors. The algorithm performance on the Linux Cluster reaches 75% of the performance on the SGI Origin 2000 when the tournament size is about one million. Computational resources and technical support are provided by the Center for Computational Research (CCR) at the State University of New York at Buffalo. Chun-Hsi Huang received his Ph.D. degree in Computer Science from the State University of New York at Buffalo in 2001. His is currently an Assistant Professor of Computer Science and Engineering at the University of Connecticut. His interests include High Performance Parallel Computing, Cluster and Grid Computing, Biomedical and Health Informatics, Algorithm Design and Analysis, Experimental Algorithms and Computational Biology. Sanguthevar Rajasekaran received his Ph.D. degree in Computer Science from Harvard University in 1988. Currently he is the UTC Chair Professor of Computer Science and Engineering at the University of Connecticut and the Director of Booth Engineering Center for Advanced Technologies (BECAT). His research interests include Parallel Algorithms, Bioinformatics, Data Mining, Randomized Computing, Computer Simulations, and Combinatorial Optimization. Laurence Tianruo Yang received is Ph.D. degree in Computer Science from the Oxford University. He is currently a professor of Computer Science of the St. Francis Xavier University in Canada. His research interests include high-performance computing, embedded systems, computer archtecture and high-speed networking. Xin He received his Ph.D. degree in Computer Science from the Ohio State University in 1987. He is currently Professor of Computer Science and Engineering at the State University of New York at Buffalo. His research interests include Algorithms, Data Structures, Combinatorics and Computational Geometry.     

Hypercalcemia and Local Production of Parathyroid Hormone-Related Protein by a Perisellar Rhabdomyosarcoma After Remote Pituitary Irradiation

ObjectiveTo describe a case of metastatic rhabdomyosarcoma originating from the sphenoid sinus in a patient previously treated with conventional irradiation for a prolactinoma, presenting as hypercalcemia in the setting of a normal level of serum parathyroid hormone-related protein (PTHrP).MethodsWe report the case of a patient who underwent remote pituitary irradiation for a prolactinoma and then presented decades later with hypercalcemia of unknown cause. His clinical course, the initial biochemical and radiologic investigations, and the results of examination of pathology specimens are reviewed.ResultsThe patient was found to have a mass in the sphenoid sinus. The pathologic features were consistent with alveolar rhabdomyosarcoma. Although he had a normal serum PTHrP level, staining of his tumor with an antibody against PTHrP revealed local production of PTHrP at the tumor margins. His bone marrow biopsy specimen showed 100% involvement with rhabdomyosarcoma.ConclusionPTHrP staining of pathology specimens might explain hypercalcemia of undetermined cause in patients with a known malignant lesion, in whom elevated serum PTHrP levels cannot be demonstrated. (Endocr Pract. 2005;11:184-189)     

The international sea‐bed authority without U.S. participation

Abstract

This paper focuses on the political dynamics of the International Sea‐Bed Authority‐on what is likely to happen if and when the Law of the Sea Treaty comes into effect without U.S. participation in the development of an international organization intended to be universal and permanent. The author has drawn heavily on his experience as Permanent Representative to UNESCO 1973–1977, and from service on delegations to numerous international conferences. His point of view tends to place great importance on the political role and structure of international organizations.     

Computer Modelling Studies on the Mechanism of Action of Ribonuclease T1

Abstract

The mechanism of action of ribonuclease (RNase) T₁ is still a matter of considerable debate as the results of x-ray, 2-D nmr and site-directed mutagenesis studies disagree regarding the role of the catalytically important residues. Hence computer modelling studies were carried out by energy minimisation of the complexes of RNase T₁ and some of its mutants (His40Ala, His40Lys, and Glu58Ala) with the substrate guanyl cytosine (GpC), and of native RNase T₁ with the reaction intermediate guanosine 2′, 3′-cyclic phosphate (G>p). The puckering of the guanosine ribose moiety in the minimum energy conformer of the RNase T₁ - GpC (substrate) complex was found to be O4′-endo and not C3′-endo as in the RNase T₁ - 3′-guanylic acid (inhibitor/product) complex. A possible scheme for the mechanism of action of RNase T₁ has been proposed on the basis of the arrangement of the catalytically important amino acid residues His40, Glu58, Arg77, and His92 around the guanosine ribose and the phosphate moiety in the RNase T₁ - GpC and RNase T₁ - G>p complexes. In this scheme, Glu58 serves as the general base group and His92 as the general acid group in the transphosphorylation step. His40 may be essential for stabilising the negatively charged phosphate moiety in the enzyme-transition state complex.     

Providing QoS in Bluetooth

Bluetooth polling, also referred to as Bluetooth MAC scheduling or intra-piconet scheduling, is the mechanism that schedules the traffic between the participants in a Bluetooth network. Hence, this mechanism is highly determining with respect to the delay packets experience in a Bluetooth network. In this paper, we present a polling mechanism that provides delay guarantees in an efficient manner, and we evaluate this polling mechanism by means of simulation. It is shown that this polling mechanism is able to provide delay guarantees while saving as much as possible resources, which can be used for transmission of best effort traffic or for retransmissions.Rachid Ait Yaiz (1974) received his BS in Electrical Engineering from the Technische Hogeschool Arnhem, the Netherlands, in 1996 and his MSc in Electrical Engineering from the University of Twente, the Netherlands, in 1999. He received his Ph.D. in Telecommunications from the same university in 2004. Currently, he works for TNO Telecom. His research interests include mobile and wireless networks, and he is particularly interested in the area of quality of service over mobile and wireless networks.Geert Heijenk (1965) received his MSc in Computer Science from University of Twente, the Netherlands, in 1988. He worked as a research staff member at the same university and received his Ph.D. in Telecommunications in 1995. He has also held a part-time position as researcher at KPN research, the Netherlands, from 1989 until 1991. From 1995 until 2003, he was with Ericsson EuroLab Netherlands, first as a senior strategic engineer, and since 1999 as a research department manager. From 1998 until 2003 he was also a part-time senior researcher at the University of Twente. Currently, he is a full-time associate professor at the same university. His research interests include mobile and wireless networks, resource management, and quality of service.     

Rhabdomyolysis after Withdrawal of Thyroid Hormone in a Patient with Papillary Thyroid Cancer

ObjectiveTo report a case of rhabdomyolysis presenting with severe hyperkalemia after withdrawal of thyroid hormone in a patient with differentiated thyroid cancer.MethodsWe describe the clinical and laboratory findings of the study patient and review the relevant literature.ResultsA 54-year-old man with progressive generalized weakness and myalgias presented with acute renal failure and hyperkalemia. He had undergone total thyroidectomy for papillary thyroid cancer 6 weeks earlier and had discontinued thyroid hormone 2 weeks before his current presentation in preparation for thyroid remnant ablation. He had a history of multiple colon and small-bowel resections for familial adenomatous polyposis and desmoid tumor. He was severely dehydrated on examination. Laboratory tests results included the following values: creatine phosphokinase, 5265 U/L (reference range, 52-336 U/L); creatinine, 2.1 mg/dL; potassium, > 8.0 mEq/L; and thyrotropin, 92.2 mIU/L. His condition was diagnosed as rhabdomyolysis, and his fluid deficit and hyperkalemia were treated aggressively. Cardiac status remained stable, and both acute renal failure and hyperkalemia improved. He then received remnant ablation, and thyroid hormone was restarted. His muscle complaints resolved over the following 3 months.ConclusionsHypothyroidism-induced rhabdomyolysis can occur during thyroid hormone withdrawal and can present with life-threatening hyperkalemia. Patients undergoing thyroid hormone withdrawal should be assessed for risk of rhabdomyolysis, and preventive strategies should be implemented, including prevention of dehydration.The use of recombinant thyrotropin, rather than thyroid hormone withdrawal, should be considered in those who are at high risk for such complications. (Endocr Pract. 2008;14:1023-1026)     

Silent Thyroiditis,Isolated Corticotropin Deficiency,and Alopecia Universalis in a Patient With Ulcerative Colitis and Elevated Levels of Plasma Factor VIII: An Unusual Case of Autoimmune Polyglandular Syndrome Type 3

ObjectiveTo describe an unusual case of autoimmune polyglandular syndrome (APS) type 3 and provide a brief review of the literature.MethodsWe present the clinical course and laboratory data of a patient with silent thyroiditis, isolated corticotropin (adrenocorticotropic hormone or ACTH) deficiency, alopecia universalis, and ulcerative colitis with an associated hypercoagulable state. The related literature is also reviewed briefly.ResultsA 43-year-old man who had a history of ulcerative colitis with an associated hypercoagulable state and alopecia universalis was referred to the endocrinology department for evaluation of fatigue and a mildly elevated level of thyrotropin (thyroid-stimulating hormone or TSH). He previously had mildly increased TSH levels, for which low-dose levothyroxine therapy had been prescribed. During use of this therapy, a suppressed TSH level developed, necessitating discontinuation of thyroid hormone therapy; a subsequent increase in TSH value was followed by a spontaneous return to euthyroidism. An ACTH stimulation test revealed adrenal insufficiency. His ACTH level was low, 21-hydroxylase antibodies were not present, and further testing demonstrated otherwise intact pituitary function. Magnetic resonance imaging of his pituitary gland showed normal findings. Treatment with hydrocortisone promptly decreased his fatigue. He was found to have an elevated factor VIII level as the cause of his hypercoagulable state. The patient continues to feel well with use of hydrocortisone therapy and has normal thyroid function.ConclusionThis patient’s components of APS type 3 have not been previously reported; thus, the complex nature of the APS variants is supported. (Endocr Pract. 2009;15:138-142)     

A cytological study of Pellia epiphylla (L.) Corda in Britain with reference to the status of Pellia borealis Lorbeer

Abstract

The history of Pellia borealis is outlined and its morphology compared with that of P. epiphylla. The techniques for preparing material for chromosome counts are described. Several gatherings of monoecious Pellia with large epidermal cells (P. borealis) were found to be haploid, n = 9. The size of the epidermal cells is shown to be valueless as a character for distinguishing the two species. It is concluded that only P. epiphylla should be retained as a species.

We wish to record our thanks to Dr S. Arnell for examining British material and for helpful correspondence; to Dr A. J. E. Smith for his valuable advice and criticism, and for the use of cytological facilities; and to all those who have contributed material of possible P. borealis.     

Sources of Thought Two 19th-century Chronobiologists: Thomas Laycock and Edward Smith

This article describes the works of two 19th-century chronobiologists. Thomas Laycock (1812-1876), who held the Chair of Medicine in Edinburgh from 1855-1876, published a series of seven articles in Lancet, all dedicated to periodicities in “vital phenomena.” Laycock considered the understanding of periodicities essential for the advancement of the treatment of diseases. Edward Smith (1818-1874) was a pioneer in experimental chronobiology. In his 1861 book entitled: Health and disease as influenced by daily, seasonal and other cyclical changes in the human, Smith summarized a large number of experiments in which he investigated the occurrence of periodicities in pulse rate, urine flow, urea excretion, and respiration. From his experimental results and those of others, Smith drew practical conclusions regarding patients' care, the timing of drug administration, and the design of night work.