The production, isolation, and characterization of a grisein-like sideromycin complex

Streplomyces griscus var. X-2455 produces an antibiotic complex which is active in vitro against a number of gram-positive and gram-negative bacteria and in mice against systemic infections caused by K, pneumoniae and D, pneumoniac. In view of the favorable chemotherapeutic index and the broad in vitro spectrum of crude concentrates, isolation of the pure antibiotic complex and the individual constituents was undertaken. The antibiotics referred to as Ho 5-2667, Ro 7-7730, and Ho 7-7731 can be differentiated by tle, ultraviolet light absorption spectra, and in vitro antibacterial activities. They all contain iron and may be classified as sideromycins. From antibiotic concentrates an antibacterially inactive substance was isolated and identified as N-acetyltyramine.     

Larvicidal potential of the polyol sweeteners erythritol and xylitol in two filth fly species

The house fly, Musca domestica (L.) (Diptera: Muscidae), and the stable fly, Stomoxys calcitrans (L.) (Diptera: Muscidae), are two filth flies responsible for significant economic losses in animal production. Although some chemical control products target adults of both species, differences in mouthpart morphology and behavior necessitates distinct modalities for each. For these reasons, larvicides are an attractive means of chemical control. We assessed the potential of the polyol sweeteners erythritol and xylitol as larvicides to the house fly and stable fly. LC₅₀ values of erythritol against 2^nd instar larvae were 34.94 mg/g media (house fly) and 22.10 mg/g media (stable fly). For xylitol, LC₅₀ values were 74.91 mg/g media (house fly) and 41.58 mg/g media (stable fly). When given a choice, neither species showed a preference for ovipositing in media treated with either sweetener at various concentrations or in media without sweetener. Significantly lower development from egg to adult was observed when the 2^nd instar LC₅₀ equivalent of each sweetener was present in the media compared to controls. Erythritol and xylitol both have larvicidal qualities, however their effective concentrations would necessitate creative product formulation and deployment methods to control all stages of developing flies.     

Mn versus Al in Layered Oxide Cathodes in Lithium‐Ion Batteries: A Comprehensive Evaluation on Long‐Term Cyclability

Nickel‐rich layered oxide cathodes with the composition LiNi_1?x?yCo_xMn_yO₂ (NCM, (1?x?y) ≥ 0.6) are under intense scrutiny recently to contend with commercial LiNi_0.8Co_0.15Al_0.05O₂ (NCA) for high‐energy‐density batteries for electric vehicles. However, a comprehensive assessment of their electrochemical durability is currently lacking. Herein, two in‐house cathodes, LiNi_0.8Co_0.15Al_0.05O₂ and LiNi_0.7Co_0.15Mn_0.15O₂, are investigated in a high‐voltage graphite full cell over 1500 charge‐discharge cycles (≈5–10 year service life in vehicles). Despite a lower nickel content, NCM shows more performance deterioration than NCA. Critical underlying degradation processes, including chemical, structural, and mechanical aspects, are analyzed via an arsenal of characterization techniques. Overall, Mn substitution appears far less effective than Al in suppressing active mass dissolution and irreversible phase transitions of the layered oxide cathodes. The active mass dissolution (and crossover) accelerates capacity decline with sustained parasitic reactions on the graphite anode, while the phase transitions are primarily responsible for cell resistance increase and voltage fade. With Al doping, on the other hand, secondary particle pulverization is the more limiting factor for long‐term cyclability compared to Mn. These results establish a fundamental guideline for designing high‐performing Ni‐rich NCM cathodes as a compelling alternative to NCA and other compositions for electric vehicle applications.     

Cytochrome b5 involvement in cytochrome P450 monooxygenase activities in house fly microsomes

The involvement of cytochrome b₅ in different cytochrome P450 monooxygenase and palmitoyl CoA desaturase activities in microsomes from insecticide-resistant (LPR) house flies was determined using a specific polyclonal antiserum developed against house fly cytochrome b₅. Anti-b₅ antiserum inhibited the reduction of cytochrome b₅ by NADH-cytochrome b₅ reductase. The antiserum also inhibited palmitoyl CoA desaturase, methoxycoumarin-O-demethylase (MCOD), ethoxycoumarin-O-deethylase (ECOD), and benzo[a]pyrene hydroxylase (aromatic hydrocarbon hydroxylase, AHH) activities. However, methoxyresorufin-O-demethylase (MROD) and ethoxyresorufin-O-deethy-lase (EROD) activities were not affected by this antiserum. These results demonstrate that cytochrome b₅ is involved in fatty acyl CoA desaturase activities and in certain cytochrome P450 monooxygenase activities (i.e., MCOD, ECOD, and AHH) in LPR house fly microsomes. Other cytochrome P450 monooxygenase activities (i.e., MROD and EROD) may not require cytochrome b₅. The results suggest that cytochrome b₅ involvement with cytochrome P450 monooxygenase activities is dependent upon the cytochrome P450 isoform involved. © 1994 Wiley-Liss, Inc.     

Effect of water activity and relative air humidity on the growth of Penicillium chrysogenum thom, Aspergillus repens (Corda) Sacc., and Trichoderma viride Pers. isolated from living spaces

Original data on the growth parameters of the fungi Penicillium chrysogenum Thom, Aspergillus repens (Corda) Sacc., and Trichoderma viride Pers. isolated from living spaces in Moscow are presented. Spore germination, fungal growth, and the radial growth rate of the colonies were investigated upon cultivation on agarized nutrient media with different water activity (a_w) values. Spore germination and fungal growth were studied in house dust under laboratory conditions at different relative air humidity (RH). It was shown that, at decreased a_w and RH, the spore germination time increased, as did the period from germination to mycelium and conidia formation, while the radial growth rate of colonies decreased. House dust was found to be a suitable growth substrate for A. repens and P. chrysogenum, supporting their complete life cycle. It was suggested that house dust is unsuitable as a substrate for the growth of T. viride. The a_w and RH ranges for development of these micromycetes were determined. On this basis, the A. repens, P. chrysogenum, and T. viride strains isolated from living spaces were identified as xerophilic, xerotolerant, and hygrophilic ones, respectively.     

Aqueous silicate complexes in wheat, Triticum aestivum L.

The chemical speciation of silicon in xylem exudate from wheat (Triticum aestivum L.) was examined by ²⁹Si NMR spectroscopy. Wheat plants were grown to maturity in silicon‐free nutrient medium, and then transferred to a solution containing 0.02 mm ²⁹Si‐enriched silicic acid. After 30 min the shoots were excised and xylem exudate was collected. Within 10 min the Si concentration of the xylem exudate reached values greatly in excess of that of the starting nutrient solution, eventually reaching levels as high as 8 mm . Silicon‐29 nuclear magnetic resonance spectra indicated the existence of only two Si‐containing species in the xylem exudate, mono and disilicic acid (H₄SiO₄^o and (HO)₃Si(µ‐O)Si(OH)₃^o) in a ratio of approximately 7 : 1. Significantly, there was no evidence of organosilicate complexes. Nevertheless, the efficiency by which the plant concentrates aqueous silicon indicates active mechanisms of silicon transport across root cell membranes.     

Moult-related reduction of aerobic scope in passerine birds

It is well established that the nutrient and energy requirements of birds increase substantially during moult, but it is not known if these increased demands affect their aerobic capacity. We quantified the absolute aerobic scope of house and Spanish sparrows, Passer domesticus and P. hispaniolensis, respectively, before and during sequential stages of their moult period. The absolute aerobic scope (AAS) is the difference between maximum metabolic rate (MMR) during peak locomotor activities and minimum resting metabolic rate (RMR_min), thus representing the amount of aerobic power above that committed to maintenance needs available for other activities. As expected, RMR_min increased over the moult period by up to 40 and 63% in house and Spanish sparrows, respectively. Surprisingly, the maximum metabolic rates also decreased during moult in both species, declining as much as 25 and 38% compared with pre-moult values of house and Spanish sparrows, respectively. The concurrent changes in RMR_min and MMR during moult resulted in significant decreases in AAS, being up to 32 and 47% lower than pre-moult levels of house and Spanish sparrows, respectively, during moult stages having substantial feather replacement. We argue that the combination of reduced flight efficiency due to loss of wing feathers and reduced aerobic capacity places moulting birds at greater risk of predation. Such performance constraints likely contribute to most birds temporally separating moult from annual events requiring peak physiological capacity such as breeding and migration.

     

Studies on Biological Activity of Cyclic Imide Compounds

The structure-activity relationships of l-phenylpyrrolidine-2,5-dione derivatives were investigated on Sclerotinia sclerotiorum by the agar dilution method. In addition, several representative compounds were tested for antimicrobial spectra in vitro with 15 pathogenic microbes and for foliage protection activity in green house tests with rice blast, rice brown spot, rice sheath blight and kidney bean stem rot. It was found that 3,5-dihalo-substituents on the benzene moiety are essential to high antifungal activity against Sclerotinia sclerotiorum. Generally, l-(3′,5′-dihalophenyl)pyrrolidine-2,5-diones are active against Corticiaceae, Dematiaceae, Pleosporaceae and Sclerotiniaceae, especially active against Sclerotinia sclerotiorum and Botrytis cinerea (the conidia form of Sclerotinia fuckeliana). N-(3,5-Dichlorophenyl)itaconimide showed a peculiarly broad antimicrobial spectrum. In green house tests, these compounds showed high activity against rice brown spot, rice sheath blight and kidney bean stem rot. Results of green house tests on the above-mentioned diseases correlate fairly well with those of in vitro tests.     

Microgeographic structure of Anopheles gambiae in western Kenya based on mtDNA and microsatellite loci

The population genetic structure of the Anopheles gambiae in western Kenya was studied using length variation at five microsatellite loci and sequence variation in a 648-nt mtDNA fragment. Mosquitoes were collected from houses in villages spanning up to 50 km distance, The following questions were answered, (i) Are mosquitoes in a house more related genetically to each other than mosquitoes between houses? (ii) What degree of genetic differentiation occurs on these geographical scales? (iii) How consistent are the results obtained with both types of genetic markers? At the house level, no differentiation was detected by F_ST and R_ST, and the band sharing index test revealed no significant associations of alleles across loci. Likewise, indices of kinship based on mtDNA haplotypes in houses were even lower than in the pooled sample. Therefore, the hypothesis that mosquitoes in a house are more related genetically was rejected. At increasing geographical scales, microsatellite allele distributions were similar among all population samples and no subdivision of the gene pool was detected by F_ST or R_ST. Likewise, estimates of haplotype divergence of mtDNA between populations were not higher than the within population estimates, and mtDNA-based F_ST values were not significantly different from zero. That sequence variation in mtDNA provided matching results with microsatellite loci (while high genetic variation was observed in all loci), suggested that this pattern represents the whole genome. The minimum area associated with a deme of A. gambiae in western Kenya is therefore larger than 50 km in diameter.     

Urea and thiourea transport in Aspergillus nidulans

Wild-type Aspergillus nidulans has an active transport system specific for urea which concentrates urea at least 50-fold relative to the extracellular concentration. It is substrate concentration dependent, with an apparent K _m of 3×10^–5 m for urea. Competition studies and the properties of mutants indicate that thiourea is taken up by the same system as urea. Thiourea is toxic at 5mm to wild-type cells of Aspergillus nidulans. Mutants, designated ureA1 to ureA16, resistant to thiourea have been isolated, and transport assays and growth tests show that they are specifically impaired in urea transport. The mutant ureA1 has a higher K _m value than the wild type for thiourea uptake. The ureA locus has been assigned to linkage group VIII. ureA1 is recessive for thiourea resistance while semidominant for the low uptake characteristic. The urea uptake system is under nitrogen regulation, with l-glutamine as the probable effector. The mutants, meaA8 and gdhA1, which are insensitive to ammonium control of many nitrogen-regulated metabolic systems, are also insensitive to ammonium control of urea uptake, but both are sensitive to l-glutamine regulation.Formerly at the Department of Genetics, University of Glasgow, Glasgow, Scotland.     

Genetic and Taxonomic Diversity of the House Mouse Mus musculus from the Asian Part of the Former Soviet Union

Genetic diversity of the house mouse Mus musculus from 12 local populations (n = 65) of the central and eastern parts of the former Soviet Union was examined using RAPD–PCR. About 400 loci were identified, encompassing approximately 500 kb of the mouse genome. Genetic diversity was assessed using NTSYS, POPGENE, TFPGA, and TREECON software programs. In general, the house mouse sample from the regions examined was characterized by moderate genetic variation: polymorphism P = 95.6%, P ₉₉ = 60.7%, P ₉₅ = 24.2%; heterozygosity H = 0.089; the mean observed number of alleles n _a = 1.97; effective number of alleles n _e = 1.13; intrapopulation differentiation _S = 0.387; gene diversity h = 0.09. Individual local populations displayed different levels of genetic isolation: the genetic subdivision index G _st varied from 0.086 to 0.324 at gene flow Nm varying from 5.3 to 1.05, while the interpopulation genetic distance D _N ranged from 0.059 to 0.186. Most of the genetic diversity of the total sample resided within the local populations: H _S = 0.06, total gene diversity H _T = 0.09. The exact test for differentiation, however, did not confirm the affiliation of all the mice examined to one population: ² = 1446, d.f. = 724, P = 0.000. Molecular markers specific to four subspecies (musculus, castaneus, gansuensis, and wagneri) were identified. Moreover, in some cases the populations and individual animals exhibited traits of different subspecies, suggesting their introgressive hybridization. It was demonstrated that the house mouse fauna on the territories investigated was characterized by the prevalence of musculus-specific markers, while gansuensis-specific markers ranked second. The castaneus-specific markers were highly frequent in the Far East, but almost absent in Central Asia, where wagneri-specific markers were detected. It was suggested that house mice from Turkmenistan could belong to one of the southern subspecies, which had not deeply penetrated into the Asian fauna of the former Soviet Union. In phenogenetic (UPGMA) and phylogenetic (NJ) reconstructions this form with the high bootstrap support was placed at the tree base, while the isolation of other clusters was not statistically significant. It is thus likely that the house mice from Turkmenistan are closest to the ancestral form of the genus Mus on the territory of the former Soviet Union.     

Altered S5 and S20 ribosomal proteins in revertants of an alanyl-tRNA synthetase mutant of Escherichia coli

Summary An active transport system specific for ammonium and methylammonium is decribed in wild type cells of Aspergillus nidulans. This system has a Km of less than 5x10^-5 M for ammonium as measured by the uptake of ¹⁵NH⁺ ₄ and a Km of 2x10^-5 M and apparent Vmax of 11 nanomoles/min/mg dry weight for methylammonium, by the uptake of ¹⁴C methylammonium. The system concentrates methylammonium at least 120-fold and is probably regulated by the concentration of internal ammonium.Cells of the mutant strain DER-3 possess a reduced rate of ammonium and methylammonium transport under all conditions tested. DER-3 is a double mutant, one mutation being allelic with meaA8 and designated meaA21, the other is unlinked to meaA and designated mod meaA. The heterozygous diploid DER3/+ has wild type transport, indicating that the mutations are recessive. Cells of the mutant strain amrA1 have impaired transport of ammonium and methylammonium, but only under some conditions. amrA1 is recessive. The possible defects of these mutants are discussed.     

The House Fly Attractants in Mushrooms

A house fly attracting substance, referred to as D₃ in the preceeding paper,¹⁾ was identified with 1,3-diolein.

Among the related compounds, 1- and 2-monoolein and α,ω-glycol monooleate with the formula: CH₃(CH₂)₇CH=CH(CH₂)₇COO(CH₂)_nOH (n≦6), were found to have activities ten times that of 1,3-diolein.     

Possible affinity between linkage groups V and XIII of the house mouse

Summary A possible quasi-linkage 4. is reported between linkage groups V and XIII of the house mouse. This places the centromere nearS _p if it is assumed that quasi-linkage effects are caused by the segregation of unlike centromeres. However, interference is more intense in this region than is expected for a centromeric region. There is some evidence from linkage group V data that interference in the house mouse is more intense than inDrosophila or maize. If this is true, a centromere in the region ofS _p would not be in disagreement with the interference data.     

Hybrid speciation in sparrows II: a role for sex chromosomes?

Homoploid hybrid speciation in animals is poorly understood, mainly because of the scarcity of well‐documented cases. Here, we present the results of a multilocus sequence analysis on the house sparrow (Passer domesticus), Spanish sparrow (P. hispaniolensis) and their proposed hybrid descendant, the Italian sparrow (P. italiae). The Italian sparrow is shown to be genetically intermediate between the house sparrow and Spanish sparrow, exhibiting genealogical discordance and a mosaic pattern of alleles derived from either of the putative parental species. The average variation on the Z chromosome was significantly reduced compared with autosomal variation in the putative parental species, the house sparrow and Spanish sparrow. Additionally, divergence between the two species was elevated on the Z chromosome relative to the autosomes. This pattern of variation and divergence is consistent with reduced introgression of Z‐linked genes and/or a faster‐Z effect (increased rate of adaptive divergence on the Z). F_ST‐outlier tests were consistent with the faster‐Z hypothesis: two of five Z‐linked loci (CHD1Z and PLAA) were identified as candidates for being subject to positive, divergent selection in the putative parental species. Interestingly, the two latter genes showed a mosaic pattern in the (hybrid) Italian sparrow; that is, the Italian sparrow was found to be fixed for Spanish sparrow alleles at CHD1Z and to mainly have house sparrow alleles at PLAA. Preliminary evidence presented in this study thus suggests that sex chromosomes may play a significant role in this case of homoploid hybrid speciation.     

A Kinetic Theory of First Order Cyclical Processes—Phytochrome Controlled Red Light Induced Cereal Leaf Unfolding Compared with Theory

The phytochrome controlled unfolding of cereal leaves was studied as a function of irradiation time and light intensity (narrowband red light) over a wide energy range (5 decades). With different intensities, a family of similarly shaped response curves appear with distinct time-dependent maxima and minima. A theoretical kinetic model based upon a cyclical phytochrome photoconversion scheme has been calculated by us. The theoretical calculations and the experimental findings are in excellent agreement. The same model explains the early photoresponses (first maxima) as an effect of one active phytochrome form, P₂, and the delayed photoresponses as an effect of a second active form P_n. The active transitory form, P₂ (although it may not be the primary product), is formed upon light absorption from P₁. The P₂ decays by a first order dark reaction through several inactive intermediates to P_n (active). The effect of the intermediates is mainly to delay the production of the second active product. It is possible to identify the two active products, P₂ and P_n, as P_fr and P*_fr, respectively. The presented cyclical phytochrome reaction scheme is a special case of a general first order kinetic cycle which includes all possible feed back loops. The latter scheme also has been calculated and programmed since it has a more general application.     

Maternal–foetal genomic conflict and speciation: no evidence for hybrid placental dysplasia in crosses between two house mouse subspecies

Interspecific hybridization between closely related mammalian species, including various species of the genus Mus, is commonly associated with abnormal growth of the placenta and hybrid foetuses, a phenomenon known as hybrid placental dysplasia (HPD). The role of HPD in speciation is anticipated but still poorly understood. Here, we studied placental and foetal growth in F₁ crosses between four inbred mouse strains derived from two house mouse subspecies, Mus musculus musculus and Mus musculus domesticus. These subspecies are in the early stage of speciation and still hybridize in nature. In accordance with the maternal–foetal genomic conflict hypothesis, we found different parental influences on placental and foetal development, with placental weight most affected by the father's body weight and foetal weight by the mother's body weight. After removing the effects of parents’ body weight, we did not find any significant differences in foetal or placental weights between intra‐subspecific and inter‐subspecific F₁ crosses. Nevertheless, we found that the variability in placental weight in inter‐subspecific crosses is linked to the X chromosome, similarly as for HPD in interspecific mouse crosses. Our results suggest that maternal–foetal genomic conflict occurs in the house mouse system, but has not yet diverged sufficiently to cause abnormalities in placental and foetal growth in inter‐subspecific crosses. HPD is thus unlikely to contribute to speciation in the house mouse system. However, we cannot rule out that it might have contributed to other speciation events in the genus Mus, where differences in the levels of polyandry exist between the species.     

Size differentiation in Finnish house sparrows follows Bergmann's rule with evidence of local adaptation

Bergmann's rule predicts that individuals are larger in more poleward populations and that this size gradient has an adaptive basis. Hence, phenotypic divergence in size traits between populations (P_ST) is expected to exceed the level of divergence by drift alone (F_ST). We measured 16 skeletal traits, body mass and wing length in 409 male and 296 female house sparrows Passer domesticus sampled in 12 populations throughout Finland, where the species has its northernmost European distributional margin. Morphometric differentiation across populations (P_ST) was compared with differentiation in 13 microsatellites (F_ST). We find that twelve traits phenotypically diverged more than F_ST in both sexes, and an additional two traits diverged in males. The phenotypic divergence exceeded F_ST in several traits to such a degree that findings were robust also to strong between‐population environmental effects. Divergence was particularly strong in dimensions of the bill, making it a strong candidate for the study of adaptive molecular genetic divergence. Divergent traits increased in size in more northern populations. We conclude that house sparrows show evidence of an adaptive latitudinal size gradient consistent with Bergmann's rule on the modest spatial scale of ca. 600 km.     

Simplified methods for monitoring petroleum‐contaminated ground water and soil vapor

Portable meters and simplified gas Chromatographic (GC) techniques were investigated for monitoring volatile hydrocarbon (HC), CO₂, and O₂, concentrations in groundwater, exhaust gases, and soil vapor during in situ remediation using soil vapor extraction (SVE) and air sparging (AS). Results of groundwater samples analyzed in‐house using a headspace technique compared well to split samples analyzed by a certified analytical laboratory (r² = 0.94). SVE exhaust gas HC and CO₂ concentrations measured using a GT201 portable HC/O₂ meter and a RA‐411A meter (GasTech), respectively, were highly correlated with in‐house laboratory GC analyses (r² = 0.91). O₂ concentrations fell in a small range and meter analyses were not well correlated with laboratory analyses. Results of soil gas monitoring were not as well correlated as those for exhaust gases for HC, CO₂, or O₂, perhaps due to environmental conditions such as changes in relative humidity or the wider range of soil gas values. Overall, the meters were good indicators of vapor contamination, they greatly simplified estimates of total HC mass removal, and they allowed estimates of the biological contribution to contaminant removal during the remediation process.     

Spatial variation in the evolutionary potential and constraints of basal metabolic rate and body mass in a wild bird

An organism's energy budget is strongly related to resource consumption, performance, and fitness. Hence, understanding the evolution of key energetic traits, such as basal metabolic rate (BMR), in natural populations is central for understanding life-history evolution and ecological processes. Here we used quantitative genetic analyses to study evolutionary potential of BMR in two insular populations of the house sparrow (Passer domesticus). We obtained measurements of BMR and body mass (M_b) from 911 house sparrows on the islands of Leka and Vega along the coast of Norway. These two populations were the source populations for translocations to create an additional third, admixed ‘common garden’ population in 2012. With the use of a novel genetic group animal model concomitant with a genetically determined pedigree, we differentiate genetic and environmental sources of variation, thereby providing insight into the effects of spatial population structure on evolutionary potential. We found that the evolutionary potential of BMR was similar in the two source populations, whereas the Vega population had a somewhat higher evolutionary potential of M_b than the Leka population. BMR was genetically correlated with M_b in both populations, and the conditional evolutionary potential of BMR (independent of body mass) was 41% (Leka) and 53% (Vega) lower than unconditional estimates. Overall, our results show that there is potential for BMR to evolve independently of M_b, but that selection on BMR and/or M_b may have different evolutionary consequences in different populations of the same species.