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Mature mammalian hearts possess very limited regenerative potential. The irreversible cardiomyocyte loss after heart injury can lead to heart failure and death. Pluripotent stem cells (PSCs) can differentiate into cardiomyocytes for cardiac repair, but there are obstacles to their clinical application. Among these obstacles is their potential for post-transplant rejection. Although human amniotic fluid-derived stem cells (hAFSCs) are immune privileged, they cannot induce cardiac differentiation. Thus, we generated hAFSC-derived induced PSCs (hAFSC-iPSCs) and used a Wnt-modulating differentiation protocol for the cardiac differentiation of hAFSC-iPSCs. In vitro studies using flow cytometry, immunofluorescence staining, and patch-clamp electrophysiological study, were performed to identify the characteristics of hAFSC-iPSC-derived cardiomyocytes (hAFSC-iPSC-CMs). We injected hAFSC-iPSC-CMs intramuscularly into rat infarcted hearts to evaluate the therapeutic potential of hAFSC-iPSC-CM transplantation. At day 21 of differentiation, the hAFSC-iPSC-CMs expressed cardiac-specific marker (cardiac troponin T), presented cardiomyocyte-specific electrophysiological properties, and contracted spontaneously. Importantly, these hAFSC-iPSC-CMs demonstrated low major histocompatibility complex (MHC) class I antigen expression and the absence of MHC class II antigens, indicating their low immunogenicity. The intramyocardial transplantation of hAFSC-iPSC-CMs restored cardiac function, partially remuscularized the injured region, and reduced fibrosis in the rat infarcted hearts. Therefore, hAFSC-iPSCs are potential candidates for the repair of infarcted myocardium.

Cardiovascular disease is the leading cause of deaths worldwide, claiming an estimated total of 17.9 million lives each year, of which one-third of the people are under the age of 70 years. Since adult cardiomyocytes fail to regenerate, the heart loses the ability to repair itself after an injury, making patients with heart disease suffer from poor prognosis. Pluripotent stem cells have the ability to differentiate into cardiomyocytes in vitro through a well-established process, which is a new advancement in cardiac regeneration therapy. However, pluripotent stem cell-derived cardiomyocytes have certain drawbacks, such as the risk of arrhythmia and immune incompatibility. Thus, amniotic fluid stem cells (AFSCs), a relatively novel source of stem cells, have been exploited for their ability of pluripotent differentiation. In addition, since AFSCs are weakly positive for the major histocompatibility class II molecules, they may have high immune tolerance. In summary, the possibility of development of cardiomyocytes from AFSCs, as well as their transplantation in host cells to produce mechanical contraction, has been discussed. Thus, this review article highlights the progress of AFSC therapy and its application in the treatment of heart diseases in recent years.

The fusion research activities at Southwestern Institute of Physics (SWIP) include the HL-2A & HL-2M tokamak programs, fusion reactor design and materials, along with key fusion technologies including R&D on ITER procurement packages. This paper presents the progress of fusion technology at SWIP, including the ITER first wall and blanket, Chinese helium cooled ceramic breeder test blanket module (HCCB–TBM) for ITER, gas injection system and gas discharge cleaning system, as well as the recent activities on reactor materials and R&D related to advanced divertor. The final design for ITER first wall and blanket shielding blocks allocated to SWIP have been completed, and were validated by recent tests. Major manufacturing technologies, such as forging, deep drilling, explosion bonding and deep laser welding, have been successfully demonstrated. Furthermore, the conceptual design of CN–HCCB–TBM has been completed, the related materials’ preparation, mock-up manufacturing and tests have been implemented. The tungsten divertor has been studied with various bonding and coating technologies. Meanwhile, highlights of functional material for TBM, oxides and carbides dispersion strengthened (ODS, CDS) reduced activation ferritic/martensitic (RAFM) steel, vanadium and tungsten alloys are also presented.

The first wall (FW) is key component for ITER and the Chinese DEMO—the China Fusion Engineering Test Reactor (CFETR). It faces burning plasma and has a high heat flux (HHF) surface load. Critical issues and key technologies for manufacturing the ITER and CFETR FW are discussed with regards to thermal fatigue performance, Be/CuCrZr and W/reduced activation ferritic/martensitic (RAFM) steel bonding, material properties and failure mechanisms. Design improvement of the hypervapotron cooling channel and the joint interface structure was done, which increases the thermal fatigue lifetime of the enhanced heat flux (EHF) ITER FW by more than one order of magnitude as indicated by thermo-mechanical analysis. Small mock-ups and full-size EHF FW fingers were manufactured by qualified technologies in sequence. An HHF test of the small mock-ups showed that Be tile size and defects at the Be/CuCrZr interface have a great effect on the fatigue lifetime. Manufacturing tests showed a thick oxygen-free Cu interlayer could provide a good solution for the interface cracking issue. An ITER EHF FW semi-prototype was manufactured with additional two full-size finger pairs that successfully survived the demanding HHF test at 4.7 and 5.9 MW m−2. Various manufacturing technologies for joining W/RAFM steel for the CFETR FW have been studied, including a TiN coating at the interface as a tritium permeation barrier. Hot iso-static pressed W/RAFM steel joints showed a higher bonding strength than brazing joints but varied a lot with the interlayer metals. Further studies are required to optimize the technologies.

A surface layer with a depth-dependent nanocrystalline microstructure was formed on reduced activation ferrite-martensitic (RAFM) steel by means of surface mechanical attrition treatment (SMAT). Equiaxed nano-sized grains in the surface layer were characterized by XRD, SEM and TEM, and the result indicated that the grain size decreased gradually with increasing deformation strain and strain rate. Compared with the size and number of carbides in the matrix, smaller and fewer carbides were detected in the SMAT layer, which indicated the refining and dissolving process of carbide during the drastic deformation in the SMAT process. Sub-grain boundaries (sub-GB) and high dense dislocation walls (DDWs) in ferrite were found in deformation layer, and dislocation accumulation, rearrangement and annihilation during the drastic deformation were discussed in detail. Both TEM images and XRD results demonstrate that the nanocrystalline layer has excellent thermal stability after annealing at 823 K.

The helium-cooled ceramic breeder (HCCB) test blanket module (TBM) is the primary option of the Chinese TBM program. Current progress on the design and R&D for Chinese helium-cooled ceramic breeder TBM (CN HCCB TBM) in China is presented. The main updated design and related R&D of CN HCCB TBM are introduced briefly. The mock-up fabrication and component tests for Chinese test blanket module are being carried out. Recent status of the components and fabrication technology development is also reported. The neutron multiplier Be pebbles, tritium breeder Li4SiO4 pebbles, and structure material CFL-1 are being prepared in the laboratory scale. The fabrication of 1/3 sized mock-up and construction of a He test loop are being carried out. The key technology development is proceeding to the large scale mock-up fabrication and demonstration tests toward on ITER testing.

China is a member of the ITER program and is developing her own materials for its shielding and test blanket modules. The materials include vacuum-hot-pressing (VHP) Be, CuCrZr alloy, 316L(N) and China low activation ferritic/martensitic (CLF-1) steels. Joining technologies including Be/Cu hot isostatic pressing (HIP) and electron beam (EB) weldability of 316L(N) were investigated. Chinese VHP-Be showed good properties, with BeO content and ductility that satisfy the ITER requirements. Be/Cu mock-ups were fabricated for Be qualification tests at simulated ITER vertical displacement event (VDE) and heat flux cycling conditions. Fine microstructure and good mechanical strength of the CuCrZr alloy were achieved by a pre-forging treatment, while the weldability of 316L(N) by EB was demonstrated for welding depths varying from 5 to 80 mm. Fine microstructure, high strength, and good ductility were achieved in CLF-1 steel by an optimized normalizing, tempering and aging procedure.

In this paper, the influence of smelting processes on precipitation behaviors and mechanical properties of CLF-1 (China low activation ferrite) steel was investigated. Mechanical properties of CLF-1 steels melted by vacuum induction melting (VIM, CS25 steel) and vacuum induction melting followed by consumable electrode remelting (VIM + ESR, CS350 steel) had been studied. The results indicated that the steels showed similar values of hardness and tensile strength, however, creep properties of CLF-1 steel were obviously improved by VIM + ESR process. M(23)C(6) and M(7)C(3) Carbides were precipitated in the CS25 steel, and M(23)C(6) carbides were precipitated in CS350 steel after high-temperature tempering at 1013 K for 90 min. Creep properties of CS25 steel were shown to be dramatically deteriorated by the existence of rod M(7)C(3) precipitates, which was due to W macrosegregation in the CS25 steel melted by VIM. M(7)C(3) was replaced by M(23)C(6) after ageing at 823 K for 5000 h. (C) 2010 Elsevier B.V. All rights reserved.

The purpose of this study was to detect expression of genes related to egg production in Taiwan Country chickens by suppression subtractive hybridization. Liver samples of mRNA extraction from two Taiwan Country chicken strains (L2 and B), originated from the same population but with very distinct egg production rates after long-term selection for egg and meat production respectively. Two-way subtraction was performed. The hepatic cDNA from the low egg production chickens (B) was subtracted from the hepatic cDNA from the high egg production strain (L2). The reversed subtraction (L2 from B) was also performed. The resulting differentially expressed gene fragments were cloned and sequenced. We sequenced 288 clones from the forward subtraction and 96 clones from the reverse subtraction. These genes were subjected to further screening to confirm the differential expression between the two genetic breeds of chickens. The apolipoprotein B (apoB) was expressed to a greater extent in the liver of the L2 than in the B line chickens. The 5-aminoimidazole- 4-carboxamide ribonucleotide formyltransferase/IMP cyclohydrolase (PURH) was expressed to a greater extent in the liver of the B than in the L2 strain chickens. We demonstrated that both apoB and PURH were more highly expressed in the liver than that in other tissues (muscle, ovary, and oviduct) in laying Taiwan Country chickens. Taken together, these data suggest that after the selection for egg production, expression of apoB and PURH genes were also changed. Whether the changed expression of these genes is directly related to egg production is not known, but these two genes may be useful markers for egg laying performance in Taiwan Country chickens.

Memory latency dominates the performance of many applications on modern processors, despite advances in caches and prefetching techniques. Numerous prefetching techniques, both in hardware and software, try to alleviate the memory bottleneck. One such technique, known as helper threading improves single-thread performance on a simultaneous multithreaded architecture (SMT), which shares processor resources, including caches, among logical threads. It uses otherwise idle hardware thread contexts to execute speculative threads on behalf of the main thread. Helper threading accelerates a program by exploiting a processor's multithreading capability to run assist threads. Based on the helper threading usage model, virtual multithreading (VMT), a form of switch-on-event user-level multithreading, can improve performance for real-world workloads with a wall-clock speedup of 5.0 to 38.5 percent

BACKGROUND: High circulating interleukin (IL)-18 level predicts a higher hospitalization rate among dialysis patients, possibly through cardiovascular mechanisms; however, whether higher IL-18 level is associated with mortality in dialysis patients is less clear. In addition, its impacts on left ventricular (LV) function are also unknown. We conducted a cohort study to examine the impacts of IL-18 level on LV function and prognosis among clinically stable hemodialysis patients. METHODS: Clinically stable patients undergoing maintenance hemodialysis (≥ 3 months) were prospectively enrolled from December 2008 to January 2009, and were followed up for 31 months. The enrolled patients (41% male, 66.4 ± 10.9 years of age) received 2-dimensional echocardiography and myocardial deformation (strain) analysis, including LV peak systolic longitudinal strain (GLS) and circumferential strain (CS). Laboratory measurements were also performed. Cox regression analysis was used to investigate prognostic factors. RESULTS: Seventy-five patients were stratified into 2 groups by the median value of IL-18 (654.2 pg/ml). Between these 2 groups, there was no significant difference in baseline characteristics including LV ejection fraction. The high IL-18 group had a worse LV systolic function as demonstrated by reduced GLS and CS. Seventeen patients (22.7%) died during the follow-up period. Multivariate Cox regression analysis showed that low serum albumin, the presence of hypertension, high serum IL-18, and less negative GLS (>-15%) were independently associated with all-cause mortality. No significant interaction between IL-18 and less negative GLS was noted in the final Cox model. CONCLUSION: Hemodialysis patients with high IL-18 levels tend to have worse LV systolic function and higher mortality rate. However, elevated serum IL-18 level is predictive of poor prognosis among stable hemodialysis patients, independently of LV dysfunction. This suggests an additional value of IL-18 to echocardiographic study in predicting all-cause mortality, and IL-18 may be helpful in early risk stratification of hemodialysis patients.

Using a speckle-tracking echocardiography (STE), we recently demonstrated that a left ventricular (LV) global longitudinal strain (GLS) ≥ −15% and the serum cardiac troponin T (cTnT) concentration are associated with mortality in stable hemodialysis patients with preserved LV ejection fraction (LVEF). In this study, we explored the relationship between cTnT and echocardiographic parameters and evaluated whether the prognostic value provided by cTnT is independent of a GLS ≥ −15% and vice versa. Eighty-eight stable hemodialysis patients with preserved LVEF were followed for 31 months. STE studies and measurements of cTnT were performed at baseline. CTnT concentration had a modest correlation with GLS (rs=0.44;P<0.001) but had a weak or nonsignificant correlation with other echocardiographic parameters. Adjusting for clinical parameters, hazard ratios for each increase of 0.01 ng/mL in cTnT, and a GLS ≥ −15% on mortality were 1.13 (P=0.009) and 3.09 (P=0.03) without significant interaction between cTnT and GLS ≥ −15%. In addition, an increased cTnT concentration, a GLS ≥ −15%, or their combination showed significant additional predictive value for mortality when included in models consisting of clinical parameters. Therefore, both cTnT and a GLS ≥ −15% are independent predictors of mortality and are useful for risk stratification.

Poly(styrene-co-acrylonitrile) (P(St-co-AN)) microspheres were prepared by emulsifier-free emulsion copolymerization of styrene and acrylonitrile. Presence of cyano groups on the surface of these microspheres was confirmed by X-ray Photoelectron Spectroscopic analysis. By the method of chemical metal deposition, nickel particles were formed and deposited on the surface of microspheres to form polymer metal composite microspheres which showed magnetic properties. Transmission electron microscope observation showed that nickel particles of small size (15–50 nm) were attached and distributed over the surface of P(St-co-AN) microspheres. X-ray diffraction proved that the nickel particles were in zerovalent state.

The relationship between somatic cell count (SCC), CMT, bacteria and milk composition in 111 samples from 14 milking Alpine, 9 Nubian, 12 Saanen and 26 milking Toggenburg does in Taiwan were determined. The results showed that the average SCCs were 800–3300 × 10 3 cells/ml for four breeds, but SCC and CMT scores were significantly different between breeds ( p Staphylococci (CNS) highest at 34.4% and Streptococci lowest at 9.4%; the total prevalence percentage was 43.4%. Highly significant ( p

The extent of variation in restriction sites within the spacers of the ribosomal RNA gene was determined for 36 important plant pathogenicPythiumspecies. The extent of intraspecific variation of twenty-two isolates representing threePythiumspecies collected from diverse hosts and geographical origins was also investigated. The ribosomal DNA internal transcribed spacer (ITS) regions were amplified by the polymerase chain reaction and digested with seven restriction enzymes. Length variations detected in this region ranged from 701 to 1103 base pairs. With a small number of exceptions, species could reliably be distinguished by restriction fragment length polymorphism (RFLP) analysis using four enzymes:CfoI,HinfI,MboI, andTaqI. Intraspecific variability was low. Data presented do not support the maintenance ofPythium aphanidermatumandPythium butlerias distinct species. Inferred relationships based on RFLP analysis of ITS regions were compared with those based on other characters; species with filamentous sporangia and those with globose sporangia were divided into two main branches. Sporangial form appears to be an important character. The correlation between molecular clusters and subgroups defined on the basis of sporangial form suggests an ancient differentiation of this characteristic.

Background Amniotic fluid-derived stem cells (AFSCs) are pluripotent with high renewal capacity and are not tumorigenic. We tested whether AFSCs can function as a cell source for therapeutic angiogenesis in a mouse hindlimb ischemia model. Methods Using a defined culture medium for endothelial lineage cells (ECs), we differentiated human AFSCs into AFSC-derived ECs (AFSC-ECs) in vitro , as evidenced by expression of EC markers, and capillary-like network formation on Matrigel. We assessed the in vivo therapeutic angiogenesis efficacy of AFSC-ECs in an athymic nude mouse model of hindlimb ischemia. One day after high ligation of the external iliac artery in athymic nude mice, AFSC-ECs were intramuscularly injected into ischemic limbs. Results The AFSC-ECs demonstrated endothelial cell characteristics in vitro . Four weeks later, AFSC-ECs transplantation significantly increased limb salvage (85%), compared to AFSCs (56%), human umbilical vein endothelial cells (HUVECs; 25%), or medium (0%). Laser Doppler perfusion analysis revealed that the ischemic/normal limb blood perfusion ratio significantly improved in the AFSC-EC group. AFSC-EC transplantation significantly increased capillary and arteriole densities as compared to AFSCs, HUVECs, and medium. Transplanted AFSC-ECs were incorporated into vessels in the ischemic region, as confirmed by immunofluorescent staining for human smooth muscle 22α or von Willebrand factor. Matrix metalloproteinase (MMP)-3 and MMP-9 expressions were significantly higher in AFSC-ECs. MMP-9 might activate angiogenesis by regulation of vascular endothelial growth factor. Conclusions Our study indicated that AFSC-EC transplantation improved limb salvage and blood perfusion by promoting neovascularization. Therefore, AFSC-ECs possess the potential for therapeutic angiogenesis.

Background: Satisfactory and noninvasive diagnostic tools for coronary artery disease (CAD) are not available in hemodialysis patients. We aimed to elucidate a reliable tool to diagnose CAD in these patients. Methods: 102 hemodialysis patients received 2D speckle-tracking echocardiography with left ventricular (LV) strain analysis and blood tests for cardiac troponin T, high-sensitive C-reactive protein, interleukin (IL)-6, and IL-18. Results: The levels of biomarkers did not differ between patients with and without CAD. The factors associated with CAD were decreased circumferential strain, decreased global longitudinal strain, and the number of LV segments with decreased longitudinal strain. Logistic regression analyses showed that the number of LV segments with decreased longitudinal strain, over 6 segments, was strongly associated with CAD in hemodialysis patients (OR 12.08, 95% CI 3.724–39.209). Conclusions: The noninvasive modality of speckle-tracking echocardiography with strain analysis is efficient and objective for identifying CAD in hemodialysis patients.

Prorenin, the inactive biosynthetic precursor of renin, is proteolytically cleaved in the renal juxtaglomerular cells to renin. The activity of renin is rate-limiting for generation of angiotensin II in the circulation. We identified a renal thiol protease which activates and accurately cleaves the 43-amino acid prosegment of human recombinant prorenin. In the current studies, 6.5 mg of this protease was purified from human renal cortex using a three-step procedure dependent upon Leu-Leu-arginyl affinity chromatography. This represented an overall 766-fold purification and resulted in three protein bands on sodium dodecyl sulfate-polyacrylamide gel electrophoresis of molecular weights 30,000, 25,000, and 24,000. All three bands cross-reacted with an anti-human liver cathepsin B antibody upon immunoblot analysis; electrolution of each band and amino-terminal sequence analysis confirmed that the Mr 30,000 protein was mature cathepsin B and the Mr 25,000 and 24,000 bands were cathepsin B subunits. The pH optimum for the hydrolysis of pure human recombinant prorenin by pure renal cathepsin B was 6, and the Michaelis-Menten constant, Km, of the reaction was 1.4 x 10(-9) M. Immunostaining of human kidney using a sheep anti-human cathepsin B antibody demonstrated the presence of cathepsin B in the juxtaglomerular areas of the kidney, as well as in the renal proximal tubules. Electron microscopic immunohistochemistry using the same antibody demonstrated cathepsin B in dense secretory granules of the juxtaglomerular cells. Renin was also shown to be present in these granules. This study provides both biochemical and morphological evidence that renal cathepsin B is a human prorenin-processing enzyme.

Apart from the reported PLGA submicro- and microspheres with broad size distribution, we have successfully developed a methodology using nanoprecipitation to prepare different sizes of PLGA nanoparticles with narrow size distributions. The newly developed PLGA nanoparticles could be readily modified with hydrophilic biomaterials on their surface and entrap hydrophobic drugs into their interiors. The encapsulation of FITC inside PLGA nanoparticles displayed a controlled release of drug system. The surfaces of the FITC entrapped PLGA nanoparticles were conjugated with quantum dots to serve as bimodal imaging probes. For nuclear transport, combination of nuclear localization signal (NLS) and PLGA nanoparticles, PLGA nanoparticles could successfully enter into HeLa cells nuclei. From tissue uptake results, PLGA nanoparticles had more uptaken by brain and liver than other tissues. The iron oxide nanoparticles-conjugated PLGA nanoparticle showed high efficiency of relaxivities r2 and could be used as the powerful magnetic resonance imaging (MRI) agents.

The feasibility of using dual-gate GaAs FET as a frequency multiplier over the Ku-band with a good conversion gain has been demonstrated. Experimentally, it achieved 8dB conversion gain from frequency doubling at 12.6 GHz and 2.5 dB gain from frequency tripling at 12 GHz. Also it possesses a built-in variable gain control over 36 dB dynamic range.

The knowledge-based software reuse environment (KBSRE) for program development assists the user to familiarize himself with the domain application environment, to locate partially matched components from the reusable component library, to understand the life-cycle knowledge of a component, and to decompose a component when its subcomponents are available. The knowledge base was created by the frame based component representation method and a set of decomposition rules and sibling rules. The components are used to generate the new software system by component composition methods. This KBSRE is an open system which allows the implementor to modify the knowledge base, decomposition rules, and sibling rules with minimum efforts. Development of a virtual reality application is shown as an example. >

This paper examines the efficiency of the register stack engine (RSE) in the canonical Itanium architecture, and introduces novel optimization techniques to enhance the RSE performance. To minimize spills and fills of the physical register file, optimizations are applied to reduce internal fragmentation in statically allocated register stack frames. Through the use of dynamic register usage (DRU) and dead register value information (DVI), the processor can dynamically guide allocation and deallocation of register frames. Consequently, a speculatively allocated register frame with a dynamically determined frame size can be much smaller than the statically determined frame size, thus achieving minimum spills and fills. Using the register stack engine (RSE) in the canonical Itanium architecture as the baseline reference, we thoroughly study and gauge the tradeoffs of the RSE and the proposed optimizations using a set of SPEC CPU2000 benchmarks built with different compiler optimizations. A combination of frame allocation policies using the most frequent frame size and deallocation policies using dead register information proves to be highly effective. On average, a 71% reduction in aggregate spills and fills can be achieved over the baseline reference.

The performance of in-order execution Itanium/sup TM/ processors can suffer significantly due to cache misses. Two memory latency tolerance approaches can be applied for the Itanium processors. One uses an out-of-order (OOO) execution core; the other assumes multithreading support and exploits cache prefetching via speculative precomputation (SP). This paper evaluates and contrasts these two approaches. In addition, this paper assesses the effectiveness of combining the two approaches. For a select set of memory-intensive programs, an in-order SMT Itanium processor using speculative precomputation can achieve performance improvement (92%) comparable to that of an out-of-order design (87%). Applying both 000 and SP yields a total performance improvement of 141% over the baseline in-order machine. OOO tends to be effective in prefetching-for L1 misses; whereas SP is primarily good at covering L2 and L3 misses. Our analysis indicates that the two approaches can be redundant or complementary depending on the type of delinquent loads that each targets. Both approaches are effective on delinquent loads in the loop body; however only SP is effective on delinquent loads found in loop control code.

The stratospheric Aerosol and Gas Experiments (SAGE) I and II measure Mie, Rayleigh, and gaseous extinction profiles using the solar occultation technique. These global measurements yield ozone profiles with a vertical resolution of 1 km which have been routinely obtained for the periods from February 1979 to November 1981 (SAGE I) and October 1984 to the present (SAGE II). The long-term periodic behavior of the measured ozone is presented as well as case studies of the observed short-term spatial and temporal variability. A linear regression shows annual, semiannual, and quasi-biennial oscillation features at various altitudes and latitudes which, in general, agree with past work. Also, ozone, aerosol, and water vapor data are described for the Antarctic springtime, showing large variation relative to the vortex. Cross-sections in latitude and altitude and polar plots at various altitudes clearly delineate the ozone hole vertically and areally.

A new type of apparatus, which makes a continuous automatic record of the varying heights of the Kennelly-Heaviside layers over a long period of time, has been designed. The history and the preliminary experiments are mentioned briefly. Two models are described and illustrated. The first model is a fixed piece of radio-transmission laboratory equipment, designed for maximum flexibility in operation. The second model is a light, compact, portable recorder, designed for field use. An expedition was sent to New Hampshire during the total solar eclipse of August 31, 1932. Continuous records of layer heights were made during the entire week of the eclipse. The portion of the record obtained on the afternoon of August 31 shows definite, abnormal variations of large magnitude. The F layer record shows two high peaks, with a minimum at totality, accompanied by double refraction effects. The first peak occurs forty minutes before totality, and the second peak occurs forty minutes after totality. The observations agree with the measurements made by another field expedition, and with additional records made by the laboratory apparatus in Cambridge, Mass.

Anomalous avalanche and Gunn effect are observed in a one micron gate GaAs FET. Microwave circuit implications and the causes of formation are discussed. Several proven solutions in eliminating these undesired effects are also reported.