Cold War in Asia: China's Involvement in the Korean and Vietnam War

As essential components of the Cold War, the Korean War and the Vietnam War have played significant roles in global policy among the Western forces under the leadership of the United States and the Eastern bloc led by the Soviet Union in the 20th century. Communist China, founded in 1949, was also part of the countries behind the Iron Curtain and provided substantial support to North Korea and North Vietnam in their fight against their ideological enemies. Despite the extensive research by scholars on the Korean War and the Vietnam War, as well as China’s role in both of these wars, it is interesting to know whether China’s role and attitude had changed from one war to the other. This thesis examines and compares China’s military interference in the Korean War in the beginning of the 1950s with its involvement more than ten years later in the Vietnam War through the investigation of China’s motives to enter the wars and their ways of support in connection with the development of foreign relations. While contrasting China’s role and involvement in Korea and Vietnam, similarities, but also major differences become distinguishable. This thesis argues that these major differences indicate a Chinese rethinking about a possible involvement in Vietnam because of China’s domestic problems and its foreign policy developments at that time

Application of Peptides Containing the Cleavage Sequence of Pro-TNFα in Assessing TACE Activity of Whole Cells

Tumor necrosis factor-α (TNFα) is presumably shed from cell membranes by TNFα-cleaving enzyme (TACE). The peptides SPLAQAVRSSSR and Dabcyl-LAQAVRSSSR-Edans, each encompassing the cleavage sequence of pro-TNFα recognized by TACE, were applied to intact umbilical vein endothelium (HUVEC), peripheral blood leukocytes (PBL) and the mast cell line HMC-1, which express TACE, to homogenates of rat heart tissue and to membrane and cytoplasmic extracts of PBL. Formation of SPLAQA (specific cleavage) was determined by HPLC, while cleavage (specific plus non-specific) of Dabcyl-TNFα-Edans was followed over time by measuring fluorescence. Participation of TACE was assessed from inhibition due to the drug TAPI-2. Incubation with recombinant human TACE gave specific cleavage, fully inhibitable by TAPI-2 (IC50<0.1 μM). HUVEC rapidly degraded TNFα-peptide, but in a non-specific manner (no SPLAQA detectable) and 50 μM TAPI-2 was without effect. Fluorescence was evoked when Dabcyl- LAQAVRSSSR-Edans was incubated with HMC-1 or PBL and also with cytoplasmic and membrane fractions of lysed PBL, but in no case was there significant inhibition by TAPI-2. However, marginal (10%) inhibition of fluorescence by 50 μM TAPI-2 was observed with homogenized heart tissue. This contained TACE, about 75% of which was without the inhibitory cysteine switch (Western blot). In conclusion, simple peptide analogs of pro-TNFα cannot be employed as substrates for measuring membrane TACE activity, largely due to extensive non-specific proteolytic cleavage by whole cells and cell extracts

Dynamic changes in connexin expression correlate with key events in the wound healing process.

Wound healing is a complex process requiring communication for the precise co-ordination of different cell types. The role of extracellular communication through growth factors in the wound healing process has been extensively documented, but the role of direct intercellular communication via gap junctions has scarcely been investigated. We have examined the dynamics of gap junction protein (Connexins 26, 30, 31.1 and 43) expression in the murine epidermis and dermis during wound healing, and we show that connexin expression is extremely plastic between 6 hours and 12 days post-wounding. The immediate response (6 h) to wounding is to downregulate all connexins in the epidermis, but thereafter the expression profile of each connexin changes dramatically. Here, we correlate the changing patterns of connexin expression with key events in the wound healing process

Release of TNF-α during myocardial reperfusion depends on oxidative stress and is prevented by mast cell stabilizers

Objectives: Our study sought to elucidate the role of oxidative stress for shedding of tumor necrosis factor-α (TNF-α) and for activating TNF-α-converting enzyme (TACE). Background: TNF-α, a central inflammatory cytokine, is discussed as one of the mediators of reperfusion injury. Shedding of membrane-bound pro-TNF-α is thought to be largely due to TNF-α-converting enzyme (TACE). Methods: Release of TNF-α and TACE dependency were studied in isolated rat hearts and in the human mast cell line HMC-1. Results: In reperfused hearts, interstitial release of TNF-α occurred in two phases (2–10 and >45 min). It depended on the presence of oxygen during reperfusion and was attenuated by reduced glutathione. Infusion of the oxidants H2O2 or HOCl elicited release in non-ischemic hearts. TNF-α release was inhibited in hearts treated with degranulation inhibitors ketotifen or cromoglycate, suggesting mast cells as major source for myocardial TNF-α. This was confirmed by tissue staining. Post-ischemic release of histamine, however, did not parallel that of TNF-α. Heart tissue contained mainly mature TACE. HMC-1 expressed abundant pro-TACE and cleaved the pro-TNF-α-peptide Ac-SPLAQAVRSSSR-NH2. However, cleavage was nonspecific and only partly inhibited by TACE inhibitor TAPI-2 (10–100 μmol/l), while it was stimulated by H2O2 and HOCl and fully blocked by the nonspecific metalloprotease inhibitor o-phenanthroline. Conclusions: The mechanism underlying TNF-α release from post-ischemic myocardium is oxidation-dependent but largely independent of activation of TACE. Mast cell stabilizers may be useful in preventing TNF-α release during reperfusion

Dwelling on simple stimuli in visual search

Research and theories on visual search often focus on visual guidance to explain differences in search. Guidance is the tuning of attention to target features and facilitates search because distractors that do not show target features can be more effectively ignored (skipping). As a general rule, the better the guidance is, the more efficient search is. Correspondingly, behavioral experiments often interpreted differences in efficiency as reflecting varying degrees of attentional guidance. But other factors such as the time spent on processing a distractor (dwelling) or multiple visits to the same stimulus in a search display (revisiting) are also involved in determining search efficiency. While there is some research showing that dwelling and revisiting modulate search times in addition to skipping, the corresponding studies used complex naturalistic and category-defined stimuli. The present study tests whether results from prior research can be generalized to more simple stimuli, where target-distractor similarity, a strong factor influencing search performance, can be manipulated in a detailed fashion. Thus, in the present study, simple stimuli with varying degrees of target-distractor similarity were used to deliver conclusive evidence for the contribution of dwelling and revisiting to search performance. The results have theoretical and methodological implications: They imply that visual search models should not treat dwelling and revisiting as constants across varying levels of search efficiency and that behavioral search experiments are equivocal with respect to the responsible processing mechanisms underlying more versus less efficient search. We also suggest that eye-tracking methods may be used to disentangle different search components such as skipping, dwelling, and revisiting

Underlying physics of thermal actuation in composite MEMS

Integrated micro- and nano-electromechanical (N/MEMS) sensor and actuator technology has become increasingly important to any applications with parallel processes, which clearly provide advantages in fields such as e.g. high-speed imaging and precision metrology of large substrates. Although micro-fabrication processes for integrated technology are well-established, there remain several fundamental research questions regarding optimized design parameters for an improved performance of sensors and actuators. In this work we investigate the underlying physics of a thermal actuator of a composite MEMS structure for a selected range of design parameters such as e.g. layer thicknesses, number of layers, as well as material properties. We derive and present a one-dimensional heat conduction model of an M-layered composite slab and investigate the heat transfer across three layers using Green’s function. The work, although entirely theoretical here, finds direct meaning and implementation in our ongoing collaborative work on MEMS arrays for Atomic Force Microscopy (AFM)

Evaluation einer neuen Methode zur impliziten Erfassung semantischer Assoziationseffekte im Priming-Paradigma - ein Methodenvergleich am Beispiel des Altersstereotyps

Die kognitiven Wende löste in den 70er Jahren die Erfassung sozialer Stereotype durch Fragebogen in der kognitiven Sozialpsychologie durch das Priming-Paradigma ab. Ziel der Arbeit war es, aus der Analyse bisheriger Untersuchungen geeignete Kriterien für den Nachweis automatischer Aktivierung bei der Stereotyperfassung abzuleiten. Im Rahmen eines neuen experimentellen Ansatzes wurde deren Effektivität im Vergleich zu einer klassischen Vorgehensweise anhand des Altersstereotyps überprüft. Umfangreiche Voruntersuchungen dienten der technischen Operationalisierung am Computer und der Auswahl geeigneten Stimulusmaterials. Ziel der ersten Hauptuntersuchung war es, den Nachweis von Prime-Effekten mit Hilfe der neuen Methode der visuellen Target-Verfremdung zu erbringen. Die zweite Hauptuntersuchung wiederholte den Nachweis mit verbessertem Stimulusmaterial. Im dritten Experiment fand die Prüfung der methodischen Fragestellung in Form eines Vergleichs gefundener Prime-Effekte statt. Der Beitrag der Arbeit ist in der Evaluation einer neuen Methode zur impliziten Erfassung semantischer Assoziationseffekte im Priming-Paradigma zu sehen. Erreicht wurde eine Verbesserung der Messgenauigkeit im Vergleich zur bisherigen klassischen Methode, die auf die allmähliche Target-Darbietung zurückging. Es wird dadurch möglich, zukünftig den Assoziationsgrad bestimmter Charakteristika einer sozialen Kategorie genauer zu bestimmen. Das wesentliche inhaltliche Ergebnis liegt im Nachweis der Differenzierung semantischer und evaluativer Assoziationseffekte durch systematische Valenzkontrolle. Für das Altersstereotyp hat sich dieses Kriterium als bedeutsam für die Neukonzipierung bisheriger Befunde erwiesen, die mehrheitlich seine negative Konnotation betonen. Die Annahmen anderer Studien, welche den Begriff „alt“ als eine übergeordnete Kategorie für verschiedene Subtypen von Altersstereotypen betrachten, konnten durch die vorliegenden Befunde nicht bestätigt werden

Requirements: The Key to Sustainability

Software's critical role in society demands a paradigm shift in the software engineering mind-set. This shift's focus begins in requirements engineering. This article is part of a special issue on the Future of Software Engineering

Spezielle Silazanderivate von Digallan(4) und Diindan(4) mit Ga-Ga- bzw. In-In-Bindung

Al, Ga and In can easily be incorporated in the cyclic silazane (MeSi)2(NtBu)4H2(LH2) through formal substitution of the hydrogen atoms by the metallic elements. LAlMe, LAlCl, LGaCl, LInCl as well as the side product L(H)InCl2 are obtained in high yields. X-ray structure determinations confirm the molecules LAlMe and L(H)InCl2 to be polycyclic and the metallic atoms to be four-coordinated by intramolecular nitrogen donors. When LAlCl, LGaCl and LInCl are reduced by sodium naphthalene, in the two latter cases the formation of LGaGaL and LInInL is observed. An X-ray structure determination of LInInL shows an InIn bond of 2.768(1) A° with the two indium atoms being coordinated by three nitrogen atoms each (InN ranging from 2.12(1)-2.298(7) A°). LGaGaL and LInInL can be considered as the first amides of GaII and InII