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A “counter-driver” shock tube was developed. In this device, two counter drivers are actuated with an appropriate delay time to generate the interaction between a shock wave and a flow in the opposite direction which is induced by another shock wave. The conditions for the counter drivers can be set independently. Each driver is activated by a separate electrically controlled diaphragm rupture device, in which a pneumatic piston drives a rupture needle with a temporal jitter of better than 1.1 ms. Operation demonstrations were conducted to evaluate the practical performance.

RESUMO. As magnitudes dos principais sismos da serie de Joao Câmara de 1986-1987 foram calculadas com estacoes regionais e telessismicas. Correcoes das estacoes foram determinadas permitindo obter-se valores de magnitudes mais homogeneos e com menores desvios padrao. De agosto de 1986 a fevereiro de 1987, 30 sismos tiveram magnitudes maiores ou iguais a 3,5. A magnitude do maior sismo da serie (30/11/86 as 05:19:48) foi m = 5,03 ± 0,05. Uma relacao empirica entre magnitude e duracao do sinal (m = c 1 log D + c 3 ) na estacao JC01, em Joao Câmara, foi estabelecida permitindo um calculo mais rapido de magnitude de microtremores. Para duracoes medidas ate 1 mm pico-a-pico no sismograma, c 1 = 2,05 e c 3 = –1,61 para m ? 2. O exame das relacoes frequencia-magnitude (log N = a – b m) indica que o coeficiente c 1 deve ser menor para magnitudes abaixo de 2, aproximadamente. Para a atividade geral de Joao Câmara, foi encontrado um valor tipico do parâmetro b de 1,12 ± 0,04. Nao foi observada variacao significativa no valor de b antes e depois do maior sismo de 30/11/1986. Palavras-chave: terremoto, onda de cauda, correcoes de estacao, Rio Grande do Norte. DETERMINATION OF MAGNITUDES AND MAGNITUDE-FREQUENCY RELATION FOR THE EARTHQUAKES OF JOAO CÂMARA, RN ABSTRACT. Magnitudes of the major events of the 1986-1987 Joao Câmara earthquake swarm were calculated with regional and teleseismic stations. Station corrections were determined allowing more homogeneous magnitudes with smaller standard deviations. From August 1986 to February 1987, 30 events had magnitudes greater than 3.5. The largest (November 30, 1986 at 05:19:48) had m = 5.03 ± 0.05. An empirical relation between magnitude, m, and signal duration, D, (m = c 1 log D + c 3 ) at the local station JC01 was established allowing quick estimates of magnitudes for microearthquakes. For durations measured from the P arrival to coda amplitude of 1 mm peak-to-peak, c 1 = 2.05 and c 3 = –1.61 for magnitudes greater than about 2. The study of the frequency-magnitude relation (log N = a – b m) shows that the coefficient c 1 must be smaller for magnitudes less than about 2. For the whole activity of Joao Câmara, a typical b-value of 1.12 ± 0.04 was found. No significant variation was observed in the b-value before and after the main event of November 30, 1986. Keywords: earthquake, coda wave, station corrections, Rio Grande do Norte State.

A commercial rAAV manufacturing process needs to provide a safe product at high yield, be easily scalable, regulatory-compliant, and have reasonable cost of goods. Considerations for process development include not only product quantity and quality, but also ease of obtaining equipment, performing validation, and demonstrating control. In these regards, it is usually efficient to make use of proven technologies for more established areas of manufacturing, such as cell culture and purification methods used by the recombinant protein/monoclonal antibody industry. We have focused on stable mammalian producer cell lines with adenovirus type 5 helper virus as a means of achieving these goals. This review describes our current approach for generating producer cell clones and designing a scalable, regulatory-compliant vector production and purification process that addresses any product safety concerns relating to helper virus. To date, a producer cell line-based manufacturing process has been implemented at the 250-liter production scale, with no foreseeable impediments to scaling up to commercial vector manufacturing in 2000-liter bioreactors or larger.

Recombinant adeno-associated viral vectors (rAAV) are being developed as gene therapy delivery vehicles and as genetic vaccines, and some of the most scaleable manufacturing methods for rAAV use live adenovirus to induce production. One aspect of establishing safety of rAAV products is therefore demonstrating adequate and reliable clearance of this helper virus by the vector purification process. The ICH Q5A regulatory guidance on viral safety provides recommendations for process design and characterization of viral clearance for recombinant proteins, and these principles were adapted to a rAAV serotype 1 purification process for clinical vectors. Specific objectives were to achieve overall adenovirus clearance factors significantly greater than input levels by using orthogonal separation and inactivation methods, and to segregate adenovirus from downstream operations by positioning a robust clearance step early in the process. Analytical tools for process development and characterization addressed problematic in-process samples, and a viral clearance validation study was performed using adenovirus and two non-specific model viruses. Overall clearance factors determined were >23 LRV for adenovirus, 11 LRV for BVDV, and >23 LRV for AMuLV.

Northeastern Brazil is, within the present knowledge of historical and instrumental seismicity, one the most seismic active areas in intraplate South America. Seismic activity in the region has occurred mainly around the Potiguar basin. This seismicity includes earthquake swarms characterized by instrumentally-recorded events ≤ 5.2 mb and paleoseismic events ≥ 7.0. Our study concentrates in the Joao Câmara (JC) epicentral area, where an earthquake swarm composed of more than 40,000 aftershocks occurred mainly from 1986 to 1990 along the Samambaia fault; 14 of which had mb > 4.0 and two of which had 5.1 and 5.0 mb. We describe and compare this aftershock sequence with the present-day stress field and the tectonic fabric in an attempt to understand fault geometry and local control of seismogenic faulting. Earthquake data indicate that seismicity decreased steadily from 1986 to 1998. We selected 2,746 epicenters, which provided a high-quality and precise dataset. It indicates that the fault trends 37° azimuth, dips 76°–80° to NW, and forms an alignment ∼ 27 km long that cuts across the NNE–SSW-trending ductile Precambrian fabric. The depth of these events ranged from ∼ 1 km to ∼ 9 km. The fault forms an echelon array of three main left-bend segments: one in the northern and two in the southern part of the fault. A low-seismicity zone, which marks a contractional bend, occurs between the northern and southern segments. Focal mechanisms indicate that the area is under an E–W-oriented compression, which led to strike–slip shear along the Samambaia fault with a small normal component. The fault is at 53° to the maximum compression and is severely misoriented for reactivation under the present-day stress field. The seismicity, however, spatially coincides with a brittle fabric composed of quartz veins and silicified-fault zones. We conclude that the Samambaia fault is a discontinuous and reactivated structure marked at the surface by a well-defined brittle fabric, which is associated with silica-rich fluids.

One of the most important seismic areas in Brazil is the northeastern region with earthquake activity occurring mainly in the exposed Precambrian basement around the Potiguar Mesozoic marginal basin. Since 1986, temporary seismographic networks have been deployed at many sites near the border of the Potiguar basin and also further inland. This instrumental effort has allowed a better understanding of the seismicity patterns and crustal stresses in the region. The seismicity in NE Brazil occurs mainly in swarms (lasting from months to many years) with shallow earthquakes (depths

New sensors have been developed for simultaneous monitoring and visualisation of risk conditions for mining applications to achieve an advanced safety management scheme using ‘colour of light’ as a key technology of the proposed method. These sensors are designed and built based on the new monitoring concept called onsite visualisation. They are capable of: 1) sensing data; and 2) visually outputting the measurement results simultaneously by using Light Emitting Diode (LED) for workers. In this paper two new methods for visualising deformation or force in rock supporting structures, such as rockbolts or ground anchors are reviewed. Firstly a colour of light is used as the principal indicator of deformation or force in the rockbolt or ground anchor. An additional set of stiff cable and spring is used along with rockbolt or ground anchor so that the deformation can be easily measured. The measured deformation can then be translated into colour of light using a colour-filter switch. The use of this method is suited to underground spaces for ease in visual identification. Secondly, the number of plastic optical fibres receiving sunlight becomes the principal indicator of deformation or force in rock supporting structure. A specially designed mechanical switch is set on a ground anchor head. As the force changes the tendon changes its length, which then is transferred to the shift of light blocking the metal shield panel. When the shield panel moves the number of plastic optical fibres receiving sunlight changes, from which approximate values of the anchor force can be identified. Once this sensor is set, long term observation of anchor forces (limited to observation during daytime only) becomes possible without using electricity. Some experiences in using these new tools are presented and their potential in mining applications are discussed.

Seismic monitoring of the Açu reservoir (31-m depth, 2.4 × 109 m3 in volume), in Rio Grande do Norte State, Northeastern Brazil, started in 1987 about 2 years after impoundment. The largest earthquake so far (magnitude 2.8) occurred in August 1994. From 1987 to 1989, the monthly number of induced events had a clear correlation with the water level, with a 3-month delay, and the activity occurred mainly inside the reservoir. Although no preimpoundment monitoring had been carried out, the correlation of the water level and the seismicity strongly suggests the activity was induced by pore pressure diffusion. Since 1990, the activity migrated toward the border of the reservoir, and the number of events no longer correlated with the water level. A seismographic network was deployed around the reservoir during two field campaigns (1989 and 1990/91), showing that the activity occurred preferentially with strike-slip mechanisms on NE oriented faults. The E-W orientation of the P axes, parallel to the regional maximum horizontal stress, and the presence of many NE trending faults and fractures in the Precambrian basement near the reservoir, suggest that the probably induced seismicity was a typical case of water pore pressure facilitating earthquake occurrence in pre-existing zones of weakness under high regional stresses.

Interaction between a shock wave and turbulence gives challenging research problems. Interactions between a shock wave and a vortex or a flow element of the same kind have been studied in various manner.[1-8] Impacts of a shock wave to turbulence intensity is investigated by Honkan et al.[1] and Barre et al.[2]. On the other hand, the impact of isotropic turbulence on a shock wave has been studied mainly numerically[8]. Experimental data of shock wave and isotropic turbulence are currently insufficient. The purpose of this study is to obtain experimental data on the relationship between a post-shock overpressure and characteristics of isotropic turbulence.

The effect of vesnarinone (OPC-8212), an orally active positive inotropic agent was studied in tracheal muscle isolated from guinea pigs, and the mechanism of its action was analyzed. Vesnarinone (10(-6)-10(-4) M) caused a concentration-dependent relaxation of tracheal muscle pre-contracted by 10(-4) M histamine. The potency of the relaxing effect of vesnarinone was greater than that of theophylline; the pD2 values for vesnarinone and theophylline were 4.9 and 4.5, respectively. Vesnarinone reduced the high-K(+)-induced contracture of depolarized tracheal muscle non-competitively (pD'2 = 3.7). Vesnarinone at the low concentration of 3 x 10(-6) M shifted the concentration-response curve for isoproterenol in a parallel fashion to the left. Vesnarinone additively acted on the relaxing effect of isobutyl methyl xanthine. Propranolol (10(-5) M) and reserpine pre-treatment (5 mg/kg, i.p., 24 hr) had no effect on the relaxing effect of vesnarinone. These results suggested that vesnarinone elevated the intracellular cyclic AMP level via phosphodiesterase inhibition, resulting in the tracheal muscle relaxation.

Two new quinoidal dimers, a new naphthohydroquinone anhydride, a known naphthoic acid ester derivative and two known benzoic acid derivatives were isolated from the chloroform fraction of a chloroform-methanol (1:1) extract of Rubia cordifolia L. The identification of these compounds was based on spectral analysis.

Phytochemical study of the aerial parts of Maerua crassifolia Forssk. resulted in the isolation and identification of kaempferol, quercetin, quercetin-3-0-arabinopyranoside, kaempferol-3-0-galactorhamnoside, rutin, lyoniresinol-3-0-glucopyranoside and stachydrine. These compounds were isolated and identified from this plant for the first time. The identification was based on physical, chemical and spectral studies including UV, IR, 1H-NMR ,13NMR and MS spectra.

Tricalysia dubia (Rubiaceae), an evergreen shrub or tree, is widely distributed in Taiwan, the southern parts of China and Japan. From the leaves of this plants, unique rearranged ent-kaurane glycosides A – G, and the ent-kaurane glycosides H – O, have been isolated. In our presentation, six rearranged ent-kaurane diterpenes, tricalysiolides A – F [1], tricalysiamides A – D [2], tricalysiolide H, tricalysiones A and B [3], and a known diterpene, cafestol from the wood of this plant are reported, especially their cytotoxic activity against P388 leukemia cells in mice as well as the structure elucidation using spectral analyses and chemical methods. References: [1] Nishimura, K. et al. (2006), Tetrahedron, 62, 1512. [2] (2007) J. Nat. Prod., in press. [3] (2007) Tetrahedron, in press.

[1] In the Joao Câmara area, NE Brazil, seismic anisotropy has been interpreted as the result of either Precambrian ductile fabric or stress-aligned, fluid-filled grain boundary caused by high pore fluid pressures. The first interpretation is based on the fact that the direction of the fastest S wave splitting agrees with the north-south trending Precambrian fabric. The second interpretation, related to the extensive dilatancy anisotropy (EDA), is based on the stress field orientation and on the assumption that the pore fluid pressure in the region is high enough to modify microcrack distribution and cause S wave polarization to become parallel to the north-south oriented minimum horizontal stress SHmin. Here we address this question by investigating this ambiguity. We have analyzed the seismicity in the Acu dam area, ∼150 km west of Joao Câmara, over a 3-year period. In the Acu area, the northeast-southwest trending ductile Precambrian fabric is not parallel or orthogonal to the east-west trending, maximum horizontal stress SHmax. We combined the interpretation of fastest S wave polarizations, their time delays, and fabric orientation measured in the field with side-looking airborne radar imagery taken before the lake impoundment. Thus we discriminate between (1) stress-aligned fluid-filled cracks, (2) high pore pressure fluids modifying the microcrack distribution and therefore causing 90° flips, and (3) fabric or “paleostrain” as causes for the observed S wave anisotropy. Our main result indicates that the direction of the fastest S wave polarization in the Acu dam area agrees with the northeast-southwest trending fabric (∼N40°E). EDA or 90°Flips control of seismic anisotropy, if occurring in Acu, have minor effects.

The Tucunduba Dam is about 290 km West of Fortaleza, in Ceará state. The seismic monitoring of the area, with a local network, began on June 11, 1997, soon after the occurrence of an event with magnitude 3.2 m b on June 09, 1997. The monitoring was done with one analog station (used for magnitude measurement and statistical control of the activity) and seven digital stations. The digital three-component stations were operated from June to November 1997. In this work, the data collected during digital monitoring was analyzed to determine hypocenters and focal mechanism. To determine the hypocenters, we used a half-space model, whose parameters were 5.95 km/s, for P-wave velocities, and 1.69 for the ratio between P and S-wave velocities. The active zone was nearly 1 km long, with depth between 4.5 and 5.2 km. With 16 events recorded in the same six stations, we determined the direction of the fault plane (NE-SW). The fault mechanism is strike-slip with a small normal component. The dip was estimated to be 65ºSE using composite focal mechanisms and 80ºSE from the P/S amplitudes ratios. Preliminary estimates of maximum horizontal compressive stress, from the P-axis direction, were in agreement with Ferreira et al.(1998). The small difference is probably due to influence of the sedimentary basin on the regional stress. The active area is in accordance with seismicity described by Assumpção (1998). O Açude Tucunduba está localizado no município de Senador Sá, a aproximadamente 290 km a oeste de Fortaleza - CE. O monitoramento sísmico da região foi realizado com uma rede sismográfica local e teve início em 11 de junho de 1997, logo após a ocorrência de um evento com magnitude 3,2 m b, no dia 09 de junho de 1997. A rede era composta de uma estação analógica (utilizada na determinação da magnitude e no controle estatístico da atividade) e sete estações digitais. As estações digitais, com três componentes cada, operaram no período de junho a novembro de 1997. Neste trabalho foram analisados os dados coletados pelas estações digitais objetivando a determinação de hipocentros e mecanismos focais. Para determinação hipocentral, usamos um modelo de semi-espaço, de parâmetros iguais a 5,95 km/s, para a velocidade da onda P, e 1,69, para a razão entre as velocidades das ondas P e S. A zona ativa era de aproximadamente 1 km de extensão e a profundidade variando de 4,5 a 5,2 km. Com um conjunto de 16 sismos, registrados na mesmas seis estações, foi determinado um plano de falha (NE-SW) com um mecanismo focal transcorrente e uma pequena componente normal. O mergulho foi estimado para está entre 65ºSE, usando o mecanismo focal composto e 80ºSE, através da razão das amplitudes P/S. Estimativas preliminares do esforço máximo compressivo horizontal, a partir da direção do eixo-P, estão de acordo com Ferreira et al. (1998). A pequena diferença pode ser devido à influência da bacia sedimentar no esforço regional. O comportamento da atividade está de acordo com a sismicidade descrita por Assumpção (1998).

The use of transformed cell substrates for prophylactic vaccine manufacturing is widely debated. Extensive characterization is required to address the suitability of neoplastic cell substrates for vaccine manufacture. The HeLa-based cell substrate used in the manufacture of a prophylactic rAAV-HIV vaccine, AAV2-gagPR delta RT (tgAAC09) was tested in vivo for its tumor-forming potential, the oncogenic potential of its high molecular weight DNA and the potential presence of occult oncogenic adventitious agents. This data from these in vivo studies, in conjunction with prion gene and protein characterization, cell and viral clearance studies and quantity of residual host-cell DNA levels in the purified tgAAC09 vaccine, were used to establish what we believe to be an acceptable safety profile for the vaccine manufacturing process. The tumor-producing dose in 50% of the animals was consistent with that in a published report from FDA staff for HeLa cells. High molecular weight cellular DNA was not oncogenic and no occult oncogenic agents were detected by testing in nude mice and newborn rodent models, respectively. Endogenous prion protein was also normal and genomic sequence analysis detected no mutations associated with increased risk of prion disease. In addition, the purification process used to produce this vaccine candidate removed all detectable cells (clearance of greater than 22 log10), viral clearance study showed 6-17 log10 clearance of three model viruses and host-cell DNA in the bulk product was less than 100pg host-cell DNA per dose of 3 x 10(11) DNase resistant particles (DRP) of the vaccine. Taken together, the data from the in vivo and in vitro tests that were performed to characterize the HeLa based producer cell line (T3B12-5B) and HeLa S3 cells support the use of these cells as substrates for the manufacture of a purified rAAV-HIV vaccine candidate. The data also supports the ability of the process, employing the HeLa cell substrate, used to manufacture the rAAV-HIV vaccine to produce a product as free of adventitious agents as current testing procedures can document. Safety of the rAAV-HIV vaccine is currently being assessed in a Phase I clinical trial.

An associative DNN (digital neural network) called SANNET, which is based on code and graph theories, is presented. Each neuron is an exclusive-OR unit. In the learning process, all node syndromes from all neurons are constrained to be zero, and a binary 'current' code that expresses a loop on each subnetwork is generated on the basis of the orthogonality of loops and cutsets. Only information on the tree is stored in each subnetwork. In the associative process, the incomplete code on the cotree of each subnetwork is corrected to the complete code according to the error-correcting capacity. SANNET has structural redundancy, sparsity, cellular structure, high concurrency, variable code length, robustness, testability, reliability, logical neurons, unions of logic and storage elements, no crosstalk, high speed, and a unique solution. The SANNET can be fabricated as a CMOS gate array. It can be applied to recognition and classification in which the recognized items are expressed by feature vectors with different lengths. Some simulation results for pattern completion are given. >

A high-density and quick-turnaround macrocell design method for custom VLSIs is applied to a 500 k-transistor protocol control chip, resulting in a density of about 4000 transistors/mm/sup 2/ using 0.8- mu m BiCMOS technology. An automated adaptive macrocell and a short-time custom VLSI design methodology were developed to make the logic and physical design more adaptable by offering greater variety of bit width, word length, circuit type, and signal terminals. The adaptive macrocell generation procedure consists of a logical description and a physical description with minimum information on the composition of complete macrocells, suitable for all specific uses. The variables providing adaptability are parameterized in this procedure, which is hierarchically described by network information among leaf cells or submacrocells, together with their topological placement information, permitting the adaptive macrocell to be generated automatically. An example of an ALU (arithmetic logic unit) circuit generated as a data-path submacrocell is shown. To verify the effectiveness of the proposed method, various kinds of macrocells were generated and fabricated using the 0.8- mu m, double-metal BiCMOS technology. A packet communication control circuit supporting X.25-based layer 2 and 3 protocols, which was designed by this method, is presented. >

Silicon-on-insulator (SOI) devices have several advantages. Small parasitic capacitances make them useful for high-speed, low-power and low-voltage LSIs. SOI devices are soft-error free, latchup free, and have a high-density layout due to complete isolation. In this paper, we report a 0.25 /spl mu/m CMOS/SIMOX 300 kG gate array LSI using fully-depleted MOSFETs fabricated on a low-dose high-quality SIMOX substrate.

The switching speed of semiconductor devices and integrated circuits has already outpaced the capability of conventional measuring and testing instruments. This paper reviews recent progress in optical IC-probing technologies based on electro-optic sampling, which have become the laboratory standard. Diagnoses of state-of-the-art GaAs ICs such as HBTs and FETs are also demonstrated. >

The LSI has a re-routing banyan (RRB) type architecture that allows the construction of a nearly non-blocking network using a minimum number of switching elements. The 8/spl times/8 switch-chip architecture yields a 10/sup -8/ cell loss probability for a 0.9 offered load using 13 stages ofthe LSI in a 1 Tb/s RRB network. 0.25 /spl mu/m CMOS/SIMOX devices are used to increase chip bandwidth. The SSIs of the I/O and the 4:1 MUX circuit using CMOS/SIMOX exhibit 2.6 GHz operation, that is 1.4 times faster than bulk CMOS. In addition, a CMOS/SIMOX gate operated at 2.0 V dissipates 45 % less power than a bulk CMOS gate operated with the same propagation delay at 2.5 V. Thus, the CMOS/SIMOX device allows Gb/s interfaces as a part of a hundred-kilo-gate LSI with low power consumption. The circuit design reduces the number of gate fan-outs and wiring length. The design is especially effective in rising operating frequency owing to the fact that the source-drain (S/D) capacitance is one-third that of bulk CMOS.

Hydrogen storage alloy powders of rare-earth-based alloy-Ni systems (La-Ni, Mm-Ni-Co-Al, Mm-Ni-Co-Mn-Al; Mm = misch metal) were prepared by a reduction-diffusion process. The alloy powders were evaluated as a negative electrode in an Ni-metal hydride battery. The results are summarized as follows. (1) The alloy powder was obtained as fine particles of average particle diameter around 30 μm with smooth surface. (2) The alloy powder had uniform composition with a crystal structure of the CaCu5 type. (3) The alloy powder exhibited good hydrogen absorption-desorption properties. The pressure plateau was very flat, not needing heat treatment. (4) The electrode properties of Mn-containing alloy powders were the same as those of alloys produced by a conventional induction melting and heat treatment process.

Two new quinoidal dimers, a new naphthohydroquinone anhydride, a known naphthoic acid ester derivative and two known benzoic acid derivatives were isolated from the chloroform fraction of a chloroform-methanol (1:1) extract of Rubia cordifolia L. The identification of these compounds was based on spectral analysis.

A lot of anticancer agents have been isolated from natural sources, especially from microorganisms and plants. However, there is no special type of compounds for cancer therapy. Various types of substances are effective for various types of cancers and tumors: for instance, alkaloids, lignans, terpenes and steroids, etc. In this report, the authors will describe especially about higher plants.

High performance Sm/sub 2/Fe/sub 17/N/sub 3/ magnet powder is developed by a reduction and diffusion method. Typical remanence, coercivity and maximum energy product obtained are 1.40 T, 1.13 T and 323 kJ/m/sup 3/, respectively. Decreasing samarium content, oxygen content and the amount of /spl alpha/-Fe are found to be the important factors to realize high energy product.

A novel cytotoxic cyclic heptapeptide, yunnanin C (1), was isolated from the roots of Stellaria yunnanensis. The structure of 1, cyclo(-Gly-Ile-Gly-Phe-Tyr-Ser-Pro-), was elucidated from spectroscopic evidence and by chemical degradation.

Methanol and ethyl acetate extracts of Wang Bu Liu Xing (seeds of Vaccaria segetalis, Caryophyllaceae) and cyclic peptides (named segetalins A and B) obtained from the extracts were shown to have an estrogen-like activity.

Conformational analysis of antitumor cyclic pentapeptides, astins A (1) and C (3), was made by a combination of NMR and computational techniques. These results indicated that the backbone conformations of 1 and 3, with lower activity than astin B (2), were different from that of 2. The backbone conformation together with a cis 3,4-dichlorinated proline residue was considered to play an important role in the antitumor activities of astins.

A new peptide called astin J (1) was isolated from the roots of Aster tataricus. The structure was elucidated by spectroscopic methods and chemical transformation from a cyclic pentapeptide, astin C, isolated from A. tataricus to the analogous acyclic peptide, 2. Antileukemic activities of the series of acyclic peptides are also described.

SUMMARY One of the most important seismic areas in Brazil is the northeastern region with earthquake activity occurring mainly in the exposed Precambrian basement around the Potiguar Mesozoic marginal basin. Since 1986, temporary seismographic networks have been deployed at many sites near the border of the Potiguar basin and also further inland. This instrumental eVort has allowed a better understanding of the seismicity patterns and crustal stresses in the region. The seismicity in NE Brazil occurs mainly in swarms (lasting from months to many years) with shallow earthquakes (depths

Panax quinquefolium saponin (PQS) increases the contractibility of papillary muscle of guinea pigs during electrical stimulation with frequency of 1/8-1/64Hz (P0.05). In Krebs-Henseleit solution purged with gas containing 95% N2 and 5% CO2 regardless of containing glucose or not, PQS (0.3mg/kg) has the effect of anti-hypoxia and anti-glucose deficiency (P0.05, P0.01) in the electrical stimulation with frequency of 1/8-1/64Hz.

Several aromatic ring substituent modified RA derivatives were prepared from RA-VII (1), RA-V (8) and RA-II (11), and evaluated for cytotoxicity against P388 leukemia and KB cells. In terms of IC50 values, the C zeta methoxyl group of Tyr-3 greatly influenced the activities, while the substituents at the C zeta position of Tyr-6 were less important. One of the derivatives, Tyr-6-C zeta-deoxyRA-V (9, P388, IC50, 0.0025 micrograms/ml) was nearly as active as RA-VII (1, 0.0013 micrograms/ml), and also expressed promising anti-P388 in vivo activity (test/control = 171%, at 25 mg/kg).

The structure-activity relationship of a novel natural substance murrayaquinone-A and related compounds, was studied by evaluating their positive inotropic potencies on guinea-pig papillary muscle in Krebs-Henseleit solution. Among the selected eight compounds, menadione and plumbagin (aromatic methyl-p-quinone) induced a potent triphasic inotropic response, as reported previously for murrayaquinone-A. The order of potency of these active compounds was: plumbagin (pD2 = 6.40) greater menadione (pD2 = 5.70) greater than murrayaquinone-A (pD2 = 5.27). Demethyl derivatives of aromatic methyl-p-quinones (carbazolequinone, 1,4-naphthoquinone and 2-hydroxy-1,4-naphthoquinone) and methyl-benzoquinones (co-enzyme Q10 and 2-methyl-1,4-benzoquinone) did not produce any positive inotropic effect. It is concluded that the presence of the aromatic methyl-p-quinone skeleton is essential for the development of an inotropic response. A common mechanism for this positive inotropic effect is suggested by the fact that in all cases it was triphasic in nature and inhibited in anoxic conditions or by 2,4-dinitrophenol and dicumarol.