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AbstractWe provide the first assessment of regional water chemistry and plankton (phytoplankton and crustacean zooplankton) for a suite of lakes near the Sutton River region of the north-central Hudson Bay Lowlands (HBL). We use ordination analyses to examine the spatial variation in water chemistry and plankton across lakes, and to explore the factors that may explain this variation. Based on data collected during summer from 2009 to 2011, we found that in addition to geology, water chemistry was strongly influenced by a lake’s proximity to salt water and the degree of permafrost development within its catchment. Phytoplankton composition varied across lakes based on differences in water depth and nutrient concentrations, with non-filamentous cyanobacteria and chlorophytes more common in shallow lakes, and deeper lakes dominated by planktonic diatoms or filamentous cyanophytes. Crustacean zooplankton community composition and richness in the HBL lakes was similar to communities found in Ontario lakes in more temperate regions within the Precambrian Shield. These baseline data provide a foundation upon which future surveys in this climatically sensitive region may be compared.

AbstractA multi-proxy paleolimnological survey was performed on 13 lakes in the Hudson Bay Lowlands (HBL) of northern Ontario in order to provide a regional analysis of recent environmental changes in this poorly studied sub-Arctic region. In contrast to the amplified warming experienced by most of the circumpolar Arctic since the mid-19th century, the climate of the Hudson Bay (HB) region has remained relatively cool and stable for hundreds of years. However, since approximately the 1990s, the HBL has experienced rapid and large increases in air temperature and declines in sea ice. Diatom, cladoceran, and chironomid remains preserved in the recent (surface) and pre-1850 sediments of 13 lakes were used to examine whether this new climate regime has resulted in species assemblage changes across multiple trophic levels. Our results indicate clear limnological responses to warming among the freshwater biota of HBL lakes; however, the magnitude of this change varied among both biological indicators and sites. As expected, diatoms exhibited the greatest degree of change, closely followed by chironomids, with relatively little change observed among cladoceran assemblages. Planktonic diatoms were more common in modern assemblages, often including plankters that were previously not recorded in the bottom sediments, and in fact all indicator groups recorded a change in benthic/littoral taxa in the recent sediments indicative of warming-induced increases in habitat availability due to decreased lake ice cover.

The Gravity Recovery and Climate Experiment (GRACE) twin-satellite gravimetry mission has been monitoring time-varying changes of the Earth's gravitational field on a near-global scale since 2002. One of the environmentally important signals to be detected is temporal variations induced by changes in the distribution of terrestrial water storage (i.e., hydrology). Since water is one of Australia's precious resources, it is logical to monitor its distribution, and GRACE offers one such opportunity. The second and fourth releases (referred to as RL02 and RL04) of the 'standard' monthly GRACE solutions with respect to their annual mean are analysed. When compared to rainfall data over the same time period, GRACE is shown to detect hydrological signals over Australia, with the RL04 data showing better results. However, the relatively small hydrological signal typical for much of Australia is obscured by deficiencies in the standard GRACE data processing and filtering methods. Spectral leakage of oceanic mass changes also still contaminates the small hydrological signals typical over land. It is therefore recommended that Australia-focussed reprocessing of GRACE data is needed for useful hydrological signals to be extracted. Naturally, this will have to be verified by independent 'in situ' external sources such as rainfall, soil moisture and groundwater borehole piezometer data over Australia.

In der Prozessindustrie nehmen in Folge des globalen Wettbewerbsdrucks die Anforderungen an die Leistungsfähigkeit gerührter Reaktoren zu. Diesem Trend kann durch die Optimierung und Anpassung der Rührsysteme an individuelle Betriebssituationen genügt werden. An Hand von Beispielen zu den einzelnen Grundrühraufgaben wird veranschaulicht, welches Potenzial die industrielle Rührtechnik zur Erfüllung dieser Anforderungen zu bieten hat.

This paper aims at a comparative study of several measures to compensate for gross errors in kinematic orbit data. It starts with a simulation study on the influence of a single outlier in the orbit data on the gravity field solution. It is shown that even a single outlier can degrade the resulting gravity field solution considerably. To compensate for outliers, two different strategies are investigated: wavelet filters, which detect and eliminate gross errors, and robust estimators, which due to an iterative downweighting gradually ignore those observations that lead to large residuals. Both methods are applied in the scope of the analysis of a 2-year kinematic CHAMP (challenging minisatellite payload) orbit data set. In various real data studies, robust estimators outperform wavelet filters in terms of resolution of the derived gravity field solution. This superior performance is at the cost of computational load, as robust estimators are implemented iteratively and require the solution of large sets of linear equations several times.This paper aims at a comparative study of several measures to compensate for gross errors in kinematic orbit data. It starts with a simulation study on the influence of a single outlier in the orbit data on the gravity field solution. It is shown that even a single outlier can degrade the resulting gravity field solution considerably. To compensate for outliers, two different strategies are investigated: wavelet filters, which detect and eliminate gross errors, and robust estimators, which due to an iterative downweighting gradually ignore those observations that lead to large residuals. Both methods are applied in the scope of the analysis of a 2-year kinematic CHAMP (challenging minisatellite payload) orbit data set. In various real data studies, robust estimators outperform wavelet filters in terms of resolution of the derived gravity field solution. This superior performance is at the cost of computational load, as robust estimators are implemented iteratively and require the solution of large sets of linear equations several times.

Summary: Experiments were conducted to determine the effects of brassinosteroids on microspore embryogenesis in Brassica species. Two compounds, 24-epibrassinolide (EBR) and brassinolide (BL), were evaluated. An increase in embryogenesis was observed in all Brassica napus lines evaluated, including Topas 4079 and several recalcitrant cultivars: Garrison, Westar, and Allons. Microspore embryogenesis, calculated as the number of embryos at 21 d of culture, was increased in the recalcitrant cultivars up to 12 times that of the control. An increase in microspore embryogenesis was also observed for B. juncea when EBR or BL was added to the culture medium. In constrast, no significant increases in embryogenesis was observed for several other Brassica species evaluated (i.e. B. carinata, B. nigra, and B. rapa). The addition of brassinosteroids to the induction media did not affect the subsequent conversion of the embryos to plantlets, but did appear to influence chromosome doubling.

Summary: Embryo development is a very key phase in the life cycle of seed plants. At maturity, the embryo contains the complete machinery to elaborate the entire plant body. While the embryogenic process is an innate feature of the zygote, gametic and somatic cells can undergo embryogenesis under the appropriate culture conditions. Embryogenesis is a highly regulated process and the use of mutants, especially in Arabidopsis, has allowed the identification of genes regulating pattern formation during this process. The use of such mutants has revealed the eritical roles of auxin levels and transport in the establishment of embryo axis. Root and shoot apical meristem function and integrity, have been defined by examination of genes involved in their identity and function. Further knowledge of the molecular and biochemical aspects of zygotic embryogenesis should contribute to our understanding of the underlying regulatory pathways and networks and also provide critical insights into unique totipotent features of the plant cell.

Abstract. At present, the modelling of terrain edges from discrete data clouds {x,y,z} is one of the ‘hot topics’ in the processing of laser scanning data. This paper proposes two different methods for the three-dimensional modelling of terrain edges. Common to both methods is the idea to describe the terrain edge as the intersection line of two surface patches zi=z(x,y), i=1,2. The first method is based on numerical integration of a differential equation describing the intersection line. The second method uses the snakes algorithm for the identification of the terrain edge. Both methods are tested for synthetic and real-world data examples, which shows that they are suitable for the practical extraction of edges from laser scanning data.

Abstract. The GRACE mission has substantiated the low–low satellite-to-satellite tracking (LL-SST) concept. The LL-SST configuration can be combined with the previously realized high–low SST concept in the CHAMP mission to provide a much higher accuracy. The line of sight (LOS) acceleration difference between the GRACE satellite pair, the simplest form of the combined observable, is mostly used for mapping the global gravity field of the Earth in terms of spherical harmonic coefficients. As an alternative observable, a linear combination of the gravitational gradient tensor components is proposed. Being a one-point function and having a direct relation with the field geometry (curvature of the field at the point) are two noteworthy achievements of the alternative formulation. In addition, using an observation quantity that is related to the second-instead of the first-order derivatives of the gravitational potential amplifies the high-frequency part of the signal. Since the transition from the first- to the second-order derivatives includes the application of a finite-differences scheme, the high-frequency part of the noise is also amplified. Nevertheless, due to the different spectral behaviour of signal and noise, in the end the second-order approach leads to improved gravitational field resolution. Mathematical formulae for the gradiometry approach, for both linear and higher-degree approximations, are derived. The proposed approach is implemented for recovery of the global gravitational field and the results are compared with those of LOS acceleration differences. Moreover, LOS acceleration difference residuals are calculated, which are at the level of a few tenths of mGal. Error analysis shows that the residuals of the estimated degree variances are less than 10-3. Furthermore, the gravity anomaly residuals are less than 2 mGal for most points on the Earth.

Purification of a n-BuOH-soluble partition of the MeOH extract of Morinda citrifolia (Noni) fruits led to the isolation of two new iridoid glucosides, 6α-hydroxyadoxoside (1) and 6β,7β-epoxy-8-epi-splendoside (2), as well as 17 known compounds, americanin A (3), narcissoside (4), asperuloside, asperulosidic acid, borreriagenin, citrifolinin B epimer a, citrifolinin B epimer b, cytidine, deacetylasperuloside, dehydromethoxygaertneroside, epi-dihydrocornin, d-glucose,  d-mannitol, methyl α-d-fructofuranoside, methyl β-d-fructofuranoside, nicotifloroside, and β-sitosterol 3-O-β-d-glucopyranoside. The structures of the new compounds were determined by spectroscopic data interpretation. Compound 4, borreriagenin, cytidine, deacetylasperuloside, dehydromethoxygaertneroside, epi-dihydrocornin, methyl α-d-fructofuranoside, and methyl β-d-fructofuranoside were isolated for the first time from M. citrifolia. The antioxidant activity was evaluated for all isolates in terms of both DPPH and ONOO^- bioassays. The neolignan, americanin A (3), was found to be a potent antioxidant in these assays.

A new method for the modelling of irregularly sampled surfaces is presented. The surfaces under consideration allow discontinuities of the first and higher derivatives. The method discussed is a generalization of the so called snakes approximation method. The variational problem, which is part of the snakes modelling, turns out to be the weighted sum of a membrane and a thin-plate-spline kernel. The variational problem is solved by the direct method using scaled and shifted Gaussians as base functions. The efficiency of the proposed method is demonstrated for a set of laser-scanning data.

Abstract We have previously isolated a CCAAT-binding factor B subunit gene (BnCBF-B) from Brassica napus that is widely expressed in different plant tissues and whose role is still unknown. To investigate the importance of this transcription factor subunit in plant reproductive tissues, we targeted antisense BnCBF-B transcripts to the tapetum of transgenic B. napus plants. Of the 24 independent transformants, 13 yielded reduced quantities of viable pollen, of which five were unable to produce the elongated siliques indicative of normal seed set. The decrease in pollen viability probably resulted from the precocious degeneration of the tapetal cell layer observed in these plants. Surprisingly, the male-sterile phenotype was also accompanied by a decrease in female fertility, which could be due to the expression of the antisense BnCBF-B transcripts in the female reproductive structures of the transgenic plants. These results suggest that the BnCBF-B gene plays a critical non-redundant role in plant reproductive tissues.

Thermal analysis combined with mass spectrometry was applied to radiocarbon dating procedures (age determination of carbon containing samples) to determine the optimal temperature range for the reduction of CO2over metallic cobalt of various particle sizes. Experiments were carried out to show the different catalytic activities of cobalt of particle sizes 1, 1–45 and 44 µm. The morphology of the cobalt samples and the deposited carbon were investigated. The quantification of CH4and CO formed during the reduction of CO2was done by means of pulse thermal analysis.

Abstract:  The use of adhesives with low gas permeability in packaging microcomponents provides a simple, low-cost alternative to the standard techniques for hermetic packaging. The permeability to helium of various epoxy resin adhesives was determined by means of a mass spectrometer in reference specimens of defined dimensions. The adhesive with the lowest permeability to helium was chosen to bond an evacuated LIGA gyrometer package (flatpack, volume=1.4 cm3). For comparison, a few packages were closed by laser welding. Subsequently, the pressure rise in the sealed packages due to gas permeation and desorption from the walls was measured by the integrated microsensor, and the permeation rate was determined. The permeation rates of as low as 10−17 m3/s achieved in bonded packages are comparable to those measured in laser welded packages.

Leider besteht für diesen Artikel keine Zusammenfassung. Als Einstieg stellen wir den Textanfang zur Verfügung. Jungianer stehen nicht in der Tradition empirischer Psychotherapieforschung. Sie fühlen sich eher der Individualität ihrer Patienten verpflichtet und sind daher gegenüber den Ergebnissen der empirischen Psychotherapieforschung mit dem Anspruch nach Generalisierbarkeit meist skeptisch eingestellt. Mit dieser skeptischen Einstellung stehen die Jungianer allerdings nicht alleine. Auch anderere psychoanalytische Schulrichtungen sind nur zögerlich und unter dem wachsenden Druck der Gesundheitsadministration bereit, die Qualität ihrer Behandlungen empirisch zu überprüfen.

CYP84 is a recently identified family of cytochrome P450-dependent mono-oxygenases defined by a putative ferulate-5-hydroxylase (F5H) from Arabidopsis. Until recently F5H has been thought to catalyze the hydroxylation of ferulate to 5-OH ferulate en route to sinapic acid. Sinapine, a sinapate-derived ester in the seeds, is antinutritional and a target for elimination in canola meal. We have isolated three F5H-like genes (BNF5H1-3) from a cultivated Brassica napus, whose amphidiploid progenitor is considered to have arisen from a fusion of the diploids Brassica rapa and Brassica oleracea. Two cultivated varieties of the diploids were also found to contain BNF5H3 and additionally either BNF5H1 or BNF5H2, respectively. Whereas all three are >90% identical in their coding sequence, BNF5H1 and BNF5H2 are closer to each other than to BNF5H3. This and additional data suggest that the two groups of genes have diverged in an ancestor of the diploids. B. napus showed maximal F5H expression in the stems, least in the seeds, and subtle differences among the expression profiles of the three genes elsewhere. Transgenic B. napus with cauliflower mosaic virus 35S-antisense BNF5H contained up to 40% less sinapine, from 9.0 +/- 0.3 mg in the controls to 5.3 +/- 0.3 mg g(-1) seed. F5H from Arabidopsis and a similar enzyme from sweetgum (Liquidamber styraciflua) has recently been shown to have coniferaldehyde hydroxylase activity instead of F5H activity. Thus the supply of 5-OH coniferaldehyde or 5-OH ferulate has a bearing on sinapine accumulation in canola seeds.

Abstract.: The use of wavelets for the solution of convolution equations is studied as a possible alternative to the well-established Fast Fourier Transform (FFT) technique. Two possible solution strategies are investigated: (1) The use of wavelets for the representation of both the given data and the unknown solution. This leads to an algorithm with good de-noising and data-compression properties. In terms of computational efficiency this algorithm is inferior to FFT. (2) The use of wavelets for the representation of the unknown solution and of so-called vaguelettes for the representations of the given data. This leads to an algorithm which is even faster than FFT.

Glycinebetaine (betaine) affords osmoprotection in bacteria, plants and animals, and protects cell components against harsh conditions in vitro. This and a compelling body of other evidence have encouraged the engineering of betaine production in plants lacking it. We have installed the metabolic step for oxidation of choline, a ubiquitous substance, to betaine in three diverse species, Arabidopsis, Brassica napus, and tobacco (Nicotiana tabacum), by constitutive expression of a bacterial choline oxidase gene. The highest levels of betaine in independent transgenics were 18.6, 12.8, and 13 micromol g(-1) dry weight, respectively, values 10- to 20-fold lower than the levels found in natural betaine producers. However, choline-fed transgenic plants synthesized substantially more betaine. Increasing the choline supplementation further enhanced betaine synthesis, up to 613 micromol g(-1) dry weight in Arabidopsis, 250 micromol g(-1) dry weight in B. napus, and 80 micromol g(-1) dry weight in tobacco. These studies demonstrate the need to enhance the endogenous choline supply to support accumulation of physiologically relevant amounts of betaine. A moderate stress tolerance was noted in some but not all betaine-producing transgenic lines based on relative shoot growth. Furthermore, the responses to stresses such as salinity, drought, and freezing were variable among the three species.

High resolution vibrational spectra of the tetrahalogeno-closo-1,2-diphosphahexaboranes P2B4X4, X = Cl, Br have been measured at low temperatures (20 - 60 K). The boron-halogen stretching vibrations are observed below 370 cm-1while the P-P valence vibrations are found at 414 (Cl) and 372 cm-1(Br). Due to the presence of the boron isotopes 10B and 11B the P-P stretching vibrations and the cage modes in the region of 550 to 1200 cm-1are split. Based on the crystallographic data of P2B4C14normal coordinate analyses have been performed. Using a set of 16 force constants (e.g. fd(PP) = 1.35 (X = Cl) and 1.20 (Br), fd(BB) = 1.30 / 1.65 (Cl) and 1.45 /1.60 (Br), fd(BX) = 4.40 (Cl) and 3.53 (Br) mdyn / Å) a good agreement of observed and calculated frequencies has been achieved.

Abstract: A genomic clone, Pis G363, containing the Brassica napus stigma-expressed gene Pis 63-2 was isolated and sequenced. The coding region of Pis G363 does not possess introns and shows 82% identity to the nucleotide sequence of a gene from Arabidopsis BAC clone T01B08. A 2-kb promoter fragment from Pis G363 was fused to the coding sequence of the marker enzyme β-glucuronidase (GUS) and introduced into tobacco via Agrobacterium-mediated transformation. The promoter fragment directed expression of the GUS gene in the stigma of transgenic tobacco. Some transformants also showed relatively low GUS activity in the pollen.

The TraM proteins encoded by F-like plasmids are sequence specific DNA binding proteins that are essential for conjugative DNA transfer. We investigated the quarternary structure and the DNA binding properties of the TraM wild-type protein of the resistance plasmid R1 and two mutant forms thereof. Size-exclusion chromatography and differential scanning calorimetry showed that purified TraM protein (amino acids 2-127) forms stable tetramers in solution. A truncated version of the protein termed TraMM26 (amino acids 2-56) forms dimers. Thus, the dimerization and tetramerization domains can be assigned to the N-terminal and C-terminal domains of TraM, respectively. Further analyses using chemical cross-linking and light scattering corroborated the preferentially tetrameric nature of the protein but also suggest that TraM has a tendency to form higher aggregates. Band-shift and fluorescence spectroscopy investigations of TraM-DNA complexes revealed that the TraM protein is also tetrameric when bound to its minimal DNA binding site. The deduced binding constant in the range of 10(8) M(-1) demonstrated a very strong binding of TraM to its preferred DNA sequence. Secondary structure analysis based on CD measurements showed that TraM is mainly alpha-helical with a significant increase in alpha-helicity (48 to 58%) upon DNA-binding, indicating an induced fit mechanism.

Thermal analysis combined with mass spectrometry was applied to radiocarbon dating procedures (age determination of carbon-containing samples). Experiments carried out under an oxygen atmosphere were used to determine carbon content and combustion range of soil and wood samples. Composition of the shell sample and its decomposition were investigated. The quantification of CO2formed by the oxidation of carbon was done by the application of pulse thermal analysis. Experiments carried out under an inert atmosphere determined the combustion range of coal with CuO as an oxygen source. To eliminate a possible source of contamination in the radiocarbon dating procedures the adsorption of CO2by CuO was investigated.

Recently, FFT techniques are frequently applied for local gravity field modeling. Compared to FFT wavelet transformation has some advantages: — higher numerical efficiency, — data compression.

We have used a complementation assay to test for activities required for the splicing of pre‐mRNA in vitro. During the hypotonic lysis of HeLa cells, two components are released from the nuclei that specifically stimulate splicing in an extract prepared from washed nuclei. The two activities separate during chromatography on DEAE‐Sepharose. One of these activities [splicing factor (SF)2] co‐purified through several steps with the lariat debranching enzyme and with a nuclease which degrades the linear portion of lariat RNAs. These enzymes could, however, be separated from SF2 by chromatography on heparin‐Sepharose. SF2 fractionates as a single protein with an apparent mol. wt. of 50 000. SF2 is resistant to mild heat treatment and to treatment with micrococcal nuclease, but it is inactivated by N‐ethylmaleimide, suggesting that it is a protein which is not associated with an essential RNA component. When SF2 is absent in a complementation assay, the generation of both intermediates and final products of the splicing reaction is completely abolished. Thus, SF2 functions in an early step of the splicing process.

Incubation of SP6 generated mouse histone H4 mRNA precursors in nuclear extracts of HeLa cells yields processed mRNA species which end on the 3′ adenosine of the conserved terminal ACCA sequence not unlike ten different histone mRNAs isolated from sea urchin embryos which end either on the 3′ C or A. In the presence of 20 mM EDTA, the cleaved off 3′ spacer portions of the RNA transcripts are readily detected, hence the 3′ ends of histone mRNAs arise as a consequence of endonucleolytic cleavage(s) of the precursor RNA. The in vitro cleavage reaction is specifically inhibited by human antisera of the Sm‐serotype, but not by control sera and can be rescued by the addition of a preparation of partially purified small nuclear RNPs to the antibody‐depleted extract. Interestingly, the snRNP preparation is sufficient to elicit 3′ processing of pre‐mRNA in the absence of added nuclear extract.

We have tested deletion and substitution mutants of bovine poly(A) polymerase, and have identified a small region that overlaps with a nuclear localization signal and binds to the RNA primer. Systematic mutagenesis of carboxylic amino acids led to the identification of three aspartates that are essential for catalysis. Sequence and secondary structure comparisons of regions surrounding these aspartates with sequences of other polymerases revealed a significant homology to the palm structure of DNA polymerase beta, terminal deoxynucleotidyltransferase and DNA polymerase IV of Saccharomyces cerevisiae, all members of the family X of polymerases. This homology extends as far as cca: tRNA nucleotidyltransferase and streptomycin adenylyltransferase, an antibiotic resistance factor.

cDNA clones encoding mammalian poly(A) polymerase were isolated with probes generated by the polymerase chain reaction based on amino acid sequences derived from the purified enzyme. A bovine cDNA clone was obtained encoding a protein of 82 kDa. Expression in Escherichia coli resulted in the appearance of a poly(A) polymerase activity that was dependent on the addition of the purified specificity factor CPF and the presence of the polyadenylation signal AAUAAA in the RNA substrate. The activity copurified with a polypeptide of the expected size. A second class of cDNAs encoded a polypeptide of 43 kDa which was closely related to the N‐terminal half of the 82 kDa protein. Northern blots showed two mRNAs of 4.2 and 2.4 kb that probably correspond to the two classes of cDNAs, as well as a third band of 1.3 kb. The sequence of the N‐terminal half of bovine poly(A) polymerase is 47% identical with the amino acid sequence of the corresponding part of yeast poly(A) polymerase. Homologies to other proteins are of uncertain significance.

Cleavage and polyadenylation factor (CPF) is required for the cleavage as well as for the subsequent polyadenylation reaction during 3′ processing of messenger RNA precursors. Here, we have investigated the interaction of CPF and poly(A) polymerase with short RNA substrates. CPF activates poly(A) polymerase to elongate RNA primers carrying the canonical hexamer recognition signal AAUAAA. CPF specifically binds to such RNA as shown by gel mobility shift assays and competition experiments. Upon binding of CPF, two polypeptides of 35 kDa and 160 kDa can be covalently crosslinked to the RNA by irradiation with UV light. These polypeptides may correspond to the smallest and the largest subunit contained in purified CPF fractions. In addition, chemical modification‐exclusion experiments demonstrate that CPF interacts directly with the AAUAAA recognition signal in the RNA. The entire hexamer signal is involved in binding of CPF since modification of any of its bases interferes with complex formation.

Polyadenylation of mRNA precursors by poly(A) polymerase depends on two specificity factors and their recognition sequences. These are cleavage and polyadenylation specificity factor (CPSF), recognizing the polyadenylation signal AAUAAA, and poly(A) binding protein II (PAB II), interacting with the growing poly(A) tail. Their effects are independent of ATP and an RNA 5′‐cap. Analysis of RNA‐protein interactions by non‐denaturing gel electrophoresis shows that CPSF, PAB II and poly(A) polymerase form a quaternary complex with the substrate RNA that transiently stabilizes the binding of poly(A) polymerase to the RNA 3′‐end. Only the complex formed from all three proteins is competent for the processive synthesis of a full‐length poly(A) tail.

We have investigated the formation of splicing complexes in vitro on mRNA precursors (pre‐mRNAs) containing two introns. Sucrose gradient sedimentation analysis revealed that the double‐intron substrate becomes associated with 60S structures, which are larger than the 50S splicing complexes we previously observed with single‐intron pre‐mRNA precursors. We have demonstrated that the 60S complex represents the assembly of two single splicing complexes on the individual introns by conversion of the 60S double splicing complexes into single 50S spliceosomes by oligodeoxynucleotide directed RNase H cleavage of the double‐intron pre‐mRNAs within the middle exon. In addition, we have observed by native gel electrophoresis a transient double ‘pre‐splicing’ complex analogous to the 35S ‘pre‐splicing’ complex previously found with single‐intron pre‐mRNAs. Our results indicate that splicing complexes can form independently and simultaneously on the individual introns of multi‐intron pre‐mRNAs and that the assembly of these multiple spliceosomes proceeds with the same stepwise pathway observed for single‐intron RNAs.

We have investigated the assembly of complexes associated with in vitro cleavage and polyadenylation of synthetic pre‐mRNAs by native gel electrophoresis. Incubation of SP6‐generated pre‐mRNA containing the adenovirus L3 polyadenylation site in HeLa cell nuclear extract results in the rapid assembly of specific complexes. Formation of these complexes precedes the appearance of cleaved intermediates and polyadenylated products and is dependent on an intact polyadenylation signal within the pre‐mRNA. The specific complexes do not form on RNAs with point mutations in the AAUAAA sequence upstream of the L3 polyadenylation site. Furthermore, such mutant RNAs cannot compete for factors involved in the assembly of specific complexes on wild‐type pre‐mRNA. Upon complex formation a 67‐nucleotide region of the L3 pre‐mRNA is protected from RNase T1 digestion. This region contains both the upstream AAUAAA signal and the GU‐rich downstream sequences. Cleavage and polyadenylation occur within the specific complexes and the processed RNA is subsequently released. We propose that the assembly of specific complexes represents an essential step during pre‐mRNA 3′ end formation in vitro.

The resistance of µm-scaled contacts to heavily doped silicon was measured as a function of current and temperature. To kinds of characteristics were identified and modelled empirically. The first kind pertains to a pair of contacts to n-type silicon and is dominated by self heating. For contacts to p-type silicon the temperature and current dependence of the contact resistance is modelled very well by a new equivalent circuit, which consists of two diodes connected anti parallel. Both types of characteristics are verified by experimental data. Circuit properties are not affected significantly by the contact resistances.

The basic idea of this paper is to modify Poisson's integral for harmonic downward continuation into a convolution formula in the space domain. In this manner, the Fast Fourier Transform can be applied. The method is applied to airborne gravimetry, motivated especially by the Greenland survey. The accuracy of data continuation from the flight-level to the ground is analysed. In particular, the influence of latitudinal extension is investigated, since the introduced convolution formula is exact only for the mid-parallel of the analysed area. The results obtained justify the conclusion that the introduced method is applicable to processing of real data. Extended quadratic areas (up to 2500 km× 2500 km) in equitorial areas and (up to 500 km× 500 km in regions with latitudes about 75°) can reffectively be processed in one single procedure.

A clinical data system is under development at the Upjohn Company that will reduce the time lag from patient visit to data availability, data entry errors, and the amount of training required for system use. The system design allows generality for both the study monitor and the biostatistician, editing of the data before entry, simplified forms design, direct entry of textual responses without coding, and a reduced need for special programs. Interactive subsystems allow a user to describe a study to the system, generate tailor-made entry/edit programs for each study, update the data base, and produce ad hoc reports. The system is being implemented on top of a data base management system and runs on an IBM 370/148 under VM/CMS.

Sedimentologic zones that are differentiated by changes in lithology, mineralogy, chemical composition, and crystal morphology observable in scanning electron micrographs occur in Missouri high-alumina clay deposits. These properties and changes suggest that the high-alumina materials originated from Pennsylvanian-age, paludal sediments deposited in depressions underlying Paleozoic carbonate rocks. Alumina was relatively enriched in zones of the deposits by leaching of silica and of alkali and alkaline earth metals from the sediments. The most intense leaching occurred on the highest parts of the Ozark Dome. Diaspore is the predominant high-alumina mineral. Boehmite, although far less abundant than diapsore, may have paragenetically preceded diaspore in some deposits. Chlorite, presumably an Al-rich variety because the content of MgO is typically <0.5%, is also present. Li, which is sporadically present, is inferred to have accumulated in the chlorite which may be a proto-variety of cookeite. Because Li+and Al3+are similar in size, Li is inferred to have accompanied Al as a resistate element in contrast to K and Na which were leached from parent phyllosilicates. Седиментологические зоны, которые различаются изменениями в литологии, минералогии, химическом составе и морфологии кристаллов, наблюдаемыми при помощи сканирующего электронного микроскопа, встречаются в осадках глины с высоким содержанием глинозема в Миссури. Эти свойства и изменения предполагают, что материалы с высоким содержанием глинозема происходили их пенсильванского века, болотных осалков, осажденных в депресиях, лежащих в основе палеозойских карбонатных пород. Окись алюминия была относительно обогащена в зонах осадков путем выщелачивания кремнезема, а также щелочных и щелочнозе мельных металлов из осадков. Наиболее интенсивное выщелачивание происходило в самых высоких частях купола Озарк. Диаспор является доминирующим минералом с высоким содержанием глинозема. Бемит, хотя намного менее обильный, чем диаспор, мог парагенетически предшествовать диаспор в некоторых осадках. Хлорит, вероятно, тип обогащенный в Аl, потому что содержание МgO типично есть <0,05%, также присутствует. Li, который присутствует случайно, аккумулируется в хлорите, который может быть прототипом кукеита. Li+и Аl3+являются похожими по размеру и потому можно заключить, что. Li сопутствует Аl как прочный элемент в противоположность К и Na, которые выщелачиваются из исходных филлосиликатов. [Е.С.] Sedimentotogische Zonen, die durch Wechsel in der Lithologie, Mineralogie, chemischen Zusammensetzung und der Kristallographie in rasterelektronenmikroskopischen Aufnahmen zum Ausdruck kamen, treten in Al-reichen Tonvorkommen in Missouri auf. Diese Eigenschaften und Veränderungen deuten darauf hin, daß sich die Al-reichen Substanzen aus Sumpfablagerungen mit pennsylvanischem Alter gebildet haben, die in Senken in den darunterliegenden palöozoischen Karbonatgesteinen abgelagert worden sind. Das Aluminium wurde in Zonen dieser Vorkommen durch Auslaugung von Silizium und Alkalien sowie Erdalkalien aus den Sedimenten relativ angereichert. Die intensivste Auslaugung fand in den obersten Teilen des Ozark Dome statt. Diaspor ist das vorherrschende Al-reiche Mineral. Boehmit, obwohl wesentlich weniger häufig als Diaspor, könnte in einigen Vorkommen paragenetisch vor dem Diaspor entstanden sein. Chlorit ist ebenfalls vorhanden, wahrscheinlich eine Al-reiche Varietät, da der Gehalt an MgO (<0,5%) dafür spricht. Vom Li, das ab und zu vorhanden ist, wird angenommen, daß es im Chlorit angereichert wurde, der eine Varietät von Kookeit sein kännte. Da Li+und Al3+etwa gleich groß sind, nimmt man an, daß sich das Li zusammen mit dem Al als ein resistentes Element verhalten hat, während, im Gegensatz dazu, K und Na aus den Ausgangsschichtsilikaten ausgelaugt wurden. [U.W.] Des zones sédimentaires qui sont différenciées par des changements de lithologie, de minéralogie, de composition chimique et de morphologie de cristaux observables sur des micrographes à électrons se trouvent dans des dépôts d’argile à contenu élevé en alumine dans le Missouri. Ces propriétés et ces changements suggèrent que les matériaux riches en alumine ont trouvé leur origine pendant l’age Pennsylvanien, sédiments paluviens deposés dans des dépressions sous des roches carbonates paléozoiques. L’alumine était relativement enrichie dans les zones des dépôts par l’extraction de silice et d’alkalins et de metaux du sol alkalins des sédiments. L’extraction la plus intense s’est produite sur les parties les plus élevées de l’Ozark Dome. La diaspore est le minéral riche en alumine prédominant. Quoi que de loin moins abondant que la diaspore, la boéhmite peut avoir precédé la diaspore paragénétiquement dans quelques dépôts. La chlorite que l’on suppose être une sorte riche en Al parceque le contenu en MgO est typiquement <0,5%, est aussi présente. Li, qui est présent sporadiquement, est inféré avoir accumulé dans la chlorite qui pourrait être une proto-variété de cookéite. Parceque Li+et Al3+sont de taille similaire, on a inféré que Li a accompagné Al en tant qu’élément resistate en contraste avec K et Na qui ont été extraits des phyllosilicates parents. [D.J.]

Polyadenylation of mRNA precursors by poly(A) polymerase depends on two specificity factors and their recognition sequences. These are cleavage and polyadenylation specificity factor (CPSF), recognizing the polyadenylation signal AAUAAA, and poly(A) binding protein II (PAB II), interacting with the growing poly(A) tail. Their effects are independent of ATP and an RNA 5′‐cap. Analysis of RNA‐protein interactions by non‐denaturing gel electrophoresis shows that CPSF, PAB II and poly(A) polymerase form a quaternary complex with the substrate RNA that transiently stabilizes the binding of poly(A) polymerase to the RNA 3′‐end. Only the complex formed from all three proteins is competent for the processive synthesis of a full‐length poly(A) tail.