Life without complex I: proteome analyses of an Arabidopsis mutant lacking the mitochondrial NADH dehydrogenase complex

The mitochondrial NADH dehydrogenase complex (complex I) is of particular importance for the respiratory chain in mitochondria. It is the major electron entry site for the mitochondrial electron transport chain (mETC) and therefore of great significance for mitochondrial ATP generation. We recently described an Arabidopsis thaliana double-mutant lacking the genes encoding the carbonic anhydrases CA1 and CA2, which both form part of a plant-specific 'carbonic anhydrase domain' of mitochondrial complex I. The mutant lacks complex I completely. Here we report extended analyses for systematically characterizing the proteome of the ca1ca2 mutant. Using various proteomic tools, we show that lack of complex I causes reorganization of the cellular respiration system. Reduced electron entry into the respiratory chain at the first segment of the mETC leads to induction of complexes II and IV as well as alternative oxidase. Increased electron entry at later segments of the mETC requires an increase in oxidation of organic substrates. This is reflected by higher abundance of proteins involved in glycolysis, the tricarboxylic acid cycle and branched-chain amino acid catabolism. Proteins involved in the light reaction of photosynthesis, the Calvin cycle, tetrapyrrole biosynthesis, and photorespiration are clearly reduced, contributing to the significant delay in growth and development of the double-mutant. Finally, enzymes involved in defense against reactive oxygen species and stress symptoms are much induced. These together with previously reported insights into the function of plant complex I, which were obtained by analysing other complex I mutants, are integrated in order to comprehensively describe 'life without complex I'.DFG/1186/Br1829/10–

Worm algorithms for the 3-state Potts model with magnetic field and chemical potential

We discuss worm algorithms for the 3-state Potts model with external field and chemical potential. The complex phase problem of this system can be overcome by using a flux representation where the new degrees of freedom are dimer and monomer variables. Working with this representation we discuss two different generalizations of the conventional Prokof'ev-Svistunov algorithm suitable for Monte Carlo simulations of the model at arbitrary chemical potential and evaluate their performance.Comment: 23 pages, 8 figure

An X-ray Microscopy Study of the Microstructural Effects on Thermal Conductivity in Cast Aluminum-Copper Compounds

A metallurgical joint between aluminum and copper established by compound casting provides for high thermal conductivity, which is required for lightweight cooling solutions in applications such as high-power light-emitting diodes or computer processors. If casting is employed in a silane-doped inert gas atmosphere whose oxygen partial pressure is adequate to extreme high vacuum, reoxidation of the active surfaces of aluminum and copper is prevented, and thus a metallurgical bond can be created directly between aluminum and copper. With this approach, thermal conductivities as high as 88.3 W/m·K were realized. In addition, X-ray microscopy was used to shed light on the microstructure–thermal property relationship. It is demonstrated that both porosity and non-bonded areas have a substantial impact on the thermophysical properties of the compound zone. Based on the data obtained, casting parameters can be developed that provide for defect-free bonding zones and optimal heat transfer between the joining partners

Sarcomas of the extremities and the pelvis: comparing local recurrence after incisional and after core-needle biopsy

BACKGROUND The degree of contamination of healthy tissue with tumor cells during a biopsy in bone or soft tissue sarcomas is clearly dependant on the type of biopsy. Some studies have confirmed a clinically relevant contamination of the biopsy tract after incisional biopsies, as opposed to core-needle biopsies. The aim of our prospective study was to evaluate the risk of local recurrence depending on the biopsy type in extremity and pelvis sarcomas. METHODS We included 162 patients with a minimum follow-up of 6 months after wide resection of extremity sarcomas. All diagnostic and therapeutic procedures were performed at a single, dedicated sarcoma center. The excision of the biopsy tract after an incisional biopsy was performed as a standard with all tumor resections. All patients received their follow-up after the conclusion of therapy at our center by means of regional MRI studies and, at a minimum, CT of the thorax to rule out pulmonary metastatic disease. The aim of the study was the evaluation of the influence of the biopsy type and of several other clinical factors on the rate of local recurrence and on the time of local recurrence-free survival. RESULTS One hundred sixty-two patients with bone or soft tissue tumors of the extremities and the pelvis underwent either an incisional or a core-needle biopsy of their tumor, with 70 sarcomas (43.2%) being located in the bone. 84.6% of all biopsies were performed as core-needle biopsies. The median follow-up time was 55.6 months, and 22 patients (13.6%) developed a local recurrence after a median time of 22.4 months. There were no significant differences between incisional and core-needle biopsy regarding the risk of local recurrence in our subgroup analysis with differentiation by kind of tissue, grading of the sarcoma, and perioperative multimodal therapy. CONCLUSIONS In a large and homogenous cohort of extremity and pelvic sarcomas, we did not find significant differences between the groups of incisional and core-needle biopsy regarding the risk of local recurrence. The excision of the biopsy tract after incisional biopsy in the context of the definitive tumor resection seems to be the decisive factor for this result

Oxygen-Free Compound Casting of Aluminum and Copper in a Silane-Doped Inert Gas Atmosphere: A New Approach to Increase Thermal Conductivity

Novel aluminum-copper compound castings devoid of oxide layers at the interface between the joining partners were developed in order to increase the thermal conductivity of the hybrid component. Due to the natural oxide layers of both aluminum and copper, metallurgical bonds between such bi-metal castings cannot be easily achieved in conventional processes. However, in an atmosphere comparable to extreme high vacuum created by using silane-doped inert gas, metallurgical bonds between the active surfaces of both aluminum and copper can be realized without additional coatings or fluxes. An intermetallic was created between aluminum and copper. Thus, very high thermal conductivities could be obtained for these hybrid castings, exceeding those of conventionally joined samples considerably. The intermetallic phase seams emerging between the joining partners were investigated using scanning electron microscopy and X-ray diffraction. The reduction of casting temperatures resulted in narrower intermetallic phase seams and these in turn in a much lower contact resistance between the two joining partners. This effect can be utilized for increasing the heat transfer capabilities of compound casting components employed for cooling heat sources such as high-power light-emitting diodes

Pennsylvania Folklife Vol. 37, No. 1

• Franklin in Fact and Fiction: The Double Perspective of Leland Baldwin • Jost Hite: From the Neckar to the Shenandoah • The Migration and Settlement of Pennsylvania Germans in Maryland, Virginia and North Carolina and Their Effects on the Landscape • Bethesda Evangelical Church in Farmers Mills: Fact and Folklore • The Tourist Bureau Shuns Me!https://digitalcommons.ursinus.edu/pafolklifemag/1117/thumbnail.jp