Nutrient turnover studies in alpine ecosystems

Summary Two plant communities, both dominated by Carex sempervirens but growing at different altitudes of the Northern Calcareous Alp region (IS: 600 m; KS: 1200 m) and one Carex ferruginea — dominated community (KC: 1200 m) are compared as to changes in dry matter, nitrogen, phosphorus, and potassium content of living and dead overground and underground phytomass.The soils of the montanic sites KS and KC are better provided with water and the three nutrients than that of the prealpine site IS. KC has the highest potassium content in the soil and in the phytomass.The dry matter increase (g/m²) of the living overground phytomass during the growing season is about 200 in IS, 360 in KS, and 340 in KC with maxima of 365 in IS, 550 in KS and 375 in KC.The increase of dead overground phytomass is highest in KS, indicating that the total annual overground production exceeds the mere increase in living parts. Furthermore, there is an increase of underground phytomass in KS and KC. The average ratio of total underground/living overground phytomass is 4.6 in IS, 3.7 in KS, but 7.5 in KC.The annual fluctuation of nitrogen (g/m²) in the living overground phytomass increases from 2.5 in IS to 3.8 in KS and to 5.9 in KC. For KS and KC these values approach the nitrogen mineralization values of the soils observed during the growing season. There is an obvious increase of nitrogen in the underground phytomass of KS and KC toward the end of the growing season. It is concluded that in KC, there is a more pronounced annual oscillation of nitrogen between overground and underground phytomass, which is not observed in IS, and which in KS is intermediate.     

Periodicity of DNA in exons

Background  

The periodic pattern of DNA in exons is a known phenomenon. It was suggested that one of the initial causes of periodicity could be the universal (RNY) _n pattern (R = A or G, Y = C or U, N = any base) of ancient RNA. Two major questions were addressed in this paper. Firstly, the cause of DNA periodicity, which was investigated by comparisons between real and simulated coding sequences. Secondly, quantification of DNA periodicity was made using an evolutionary algorithm, which was not previously used for such purposes.     

Associations of Polymorphisms in Four Candidate Genes with Carcass and/or Meat-Quality Traits in Two Meat-Type Chicken Lines

The associations between polymorphisms of five genes, calpain 1 ( CAPN1 ), follicle stimulating hormone beta (FSHB), follicle stimulating hormone receptor (FSHR), peroxisome proliferator-activated receptor gamma (PPARG), and retinol binding protein 7 (RBP7), and live weight, carcass composition, and meat-quality traits were estimated from two meat-type chickens lines (n = 311). Except for the variants of the FSHR gene, 11 SNPs of the other four genes and two diplotypes of PPARG were associated with one or more traits excluding shear factor (SF). SNP C31566680T of the CAPN1 gene was significantly associated with live weight (LW) carcass traits. The SNP A4580859C of FSHB gene was significantly associated with breast muscle weight (BrW) and LW. One of the PPARG SNPs, C5070948T, was associated with intramuscular fat content in breast (IMF _br ). Diplotype P1 of the PPARG gene was significantly associated with LW and all carcass traits. P3 were significantly associated with abdominal fat weight (AbFW). SNPs in RBP7 were only associated with BrW. These results indicate that the four genes were associated with these traits and have promise as genetic markers for future marker-assisted selection. Supplementary materials for this paper are available online.     

海南石斛化学成分研究

为了解海南石斛(Dendrobium hainanense Rolfe)的化学成分,采用色谱技术从海南石斛茎叶中分离得到14个化合物,经波谱分析分别鉴定为:2,6-二甲氧基对苯醌(1)、(+)-dehydrovomifoliol(2)、blumenol A(3)、2,7-二羟基-3,4-二甲氧基-9,10-二氢菲(4)、2,7-二羟基-3,4-二甲氧基菲(5)、3,7-二羟基-2,4-二甲氧基菲(6)、3-羟基-2,4,7-三甲氧基-9,10-二氢菲(7)、3-羟基-2,4,7-三甲氧基菲(8)、3,4,7-三羟基-2-甲氧基菲(9)、3,7-二羟基-2,4-二甲氧基-9,10-二氢菲(10)、(+)-lyoniresinol(11)、丁香脂素(12)、denchrysan A(13)和nobilone(14)。这些化合物均为首次从海南石斛中分离得到。活性测试结果表明化合物4~6、8~9、11和14对乙酰胆碱酯酶有抑制活性。     

Molecular dynamics simulation of self-assembled nanocubes in methanol

Molecular dynamics simulations were performed for the hexameric nanocubes of methylated (1₆) and demethylated (2₆) gear-shaped amphiphiles in pure methanol to reveal the difference in structural fluctuation between 1₆ and 2₆. Within our simulation time of 2.0 ns, the cubic structure of 1₆ in methanol is maintained, whereas that of 2₆ is collapsed. We found that the triple π-stacking moieties consisting of the three 3-pyridyl groups in 2₆ are more fluctuated than those in 1₆. This suggests that methyl groups serve to reduce structural fluctuation for nanocubes. We also found that the existence of the solvent molecules near the nanocube is an important factor for the collapse of the 2₆ structure.     

The insight of in vitro and in silico studies on cholinesterase inhibitors from the roots of Cimicifuga dahurica (Turcz.) Maxim.

Cholinesterases (ChEs) are enzymes that break down neurotransmitters associated with cognitive function and memory. We isolated cinnamic acids (1 and 2), indolinones (3 and 4), and cycloartane triterpenoid derivatives (5–19) from the roots of Cimicifuga dahurica (Turcz.) Maxim. by chromatography. These compounds were evaluated for their inhibitory activity toward ChEs. Compound 1 was determined to have an IC₅₀ value of 16.7?±?1.9?μM, and to act as a competitive inhibitor of acetylcholinesterase (AChE). Compounds 3, 4 and 14 were found to be noncompetitive with IC₅₀ values of 13.8?±?1.5 and 6.5?±?2.5?μM, and competitive with an IC₅₀ value of 22.6?±?0.4?μM, respectively, against butyrylcholinesterase (BuChE). Our molecular simulation suggested each key amino acid, Tyr337 of AChE and Asn228 of BuChE, which were corresponded with potential inhibitors 1, and 3 and 4, respectively. Compounds 1 and 4 were revealed to be promising compounds for inhibition of AChEs and BuChEs, respectively.     

Art in the Making

Abstract

Jan Adkins, Letterbox: The Art and History of Letters, Walker: New York, 1981, 48 pages, $10.95.

Michael Kehoe, The Puzzle of Books, Carolrhoda Books, Minneapolis, 1982, unpaged, $6.95.

Linda Bourke, Handmade Abc: A Manual Alphabet, Addison-Wesley: Reading, Mass., 1981, unpaged, $6.95.

Linda Bourke, Signs of a Friend, Addison-Wesley: Reading, Mass., 1982, unpaged, $2.95 (paper).

Philip Newth, Roly Goes Exploring, Philomel Books: New York, 1981, unpaged, $12.95 (spiral bound).

Tomas Gonzales (text by J. R. Kesselman and F. Peterson), I CAN USE TOOLS, Elsevier/Nelson: New York, 1981, unpaged, $6.25 (boards).

Harvey Weiss, Hammer and Saw, Crowell: New York, 1981, 80 pages, $9.00.

Gail Gibbons, Tool Book, Holiday House: New York, 1982, unpaged, n.p.i.

Harvey Weiss, Model Building: And How to Make Them, Thomas Crowell: New York, 1979, 96 pages, $7.95.

Paul Berman, Make-Believe Empire: A How-to Book, Atheneum: New York, 1982, 88 pages, $8.95.

Evaline Ness, Four Rooms From the Metropolitan Museum of Art, Scribners: New York, 1977, unpaged, $6.95.

Alan Rose, Build Your Own Taj Mahal, Perigee: New York, 1981, unpaged, $7.95.

Les Walker, Housebuilding for Children, The Overlook Press: New York, 1977, 175 pages, $10.00.

Jose Aruego and Ariane Dewey (story by Natalie S. Carlson), Marie Louise and Christopher at The Carnival, Scribners: New York, 1981, unpaged, $11.95

Beverley Gooding (Kenneth Grahame), Wayfarers All from The Wind in the Willows, Scribners: New York, 1981, 32 pages, $11.95.

Shawn Rice (text by Paul Rice and Peter Mayle), AS DEAD AS A DODO, Godine: Boston, 1981, unpaged, $10.95.     

Penicillin acylase in the synthesis of aminothiazole cefalosporins

Summary Cefotiam (7) and cefotaxime (8) are obtained by penicillin acylase hydrolysis of (5) and (6), prepared, in turn, by chemical condensation of 7-DIMAT (3) and 7-ACA (4), respectively, with N-phenacetyl-2-aminothiazol-4-yl acetic acids (1) and (2).     

Art in the Making

Abstract

There's Pigs and Pigs: Erik Blegvad, The Three Little Pigs, Atheneum: New York, 1980, 32 pages, $8.95.

There's Pigs and Pigs: Joseph Jacobs, The Story of the Three Little Pigs (illust. by Lorinda B. Cauley), Putnam: New York, 1980, unpaged, $8.95.

There's Pigs and Pigs: Margaret Wise Brown (illust. by Ann Strugnell), Once Upon a Time in a Pigpen, Addison-Wesley: Reading, Mass., 1980, 64 pages, $10.95.

There's Pigs and Pigs: Miska Miles (illust. by Leslie Morrill), This Little Pig, Dutton: New York, 1980, unpaged, $6.95.

Picture Books: William Steig, Gorky Rising, Farrar, Strauss &; Giroux: New York, 1980, unpaged, $10.95.

Picture Books: Charles Keeping, Willie's Fire-Engine, Oxford University: New York, 1980, unpaged, $10.95 (boards).

Picture Books: Lydia Pender (illust. by Judith Cowell), The Useless Donkeys, Warne: New York, 1979, unpaged, $9.95.

Picture Books: Lillie D. Chaffin (illust. by Lloyd Bloom), We Be Warm Till Springtime Comes, Macmillan: New York, 1980, unpaged, $9.95.

Picture Books: Kate Canning, A Painted Tale, Barrons: Woodbury, N.Y.: 1979, unpaged, $6.95 (boards).

Historical Explorations: Maurice Boutet de Monvel, Joan of Arc, Viking: New York, 1980, 55 pages, $12.95.

Historical Explorations: Mitsumasa, Anno, Anno's Medieval World, Philomel Books: New York, 1980, 48 pages, $9.99.

Historical Explorations: Peter Spier, People, Doubleday: New York, 1980, unpaged, $10.00.

Historical Explorations: John S. Goodall, An Edwardian Season, Atheneum: New York, 1980, unpaged, $7.95.

Historical Explorations: Miriam Schlein (illust. by Erik Hilgert), I, Tut, Four Winds Press: New York, 1979, unpaged, $7.95.     

Azocasein assay for alkaline protease in complex fermentation broth

Summary An azocasein assay has been developed for determination of alkaline protease in fermentation broth from a complex substrate containing ca. 50 g/l protein which to a high degree interferes with azocasein. Methods described in the literature have been found inaccurate as results deviate ca. 50% from true activity, so one of the methods is modified in order to eliminate interference. Proportionality between the relative azocasein concentration and the deviation from true activity is found. An azocasein concentration of 350 mg azocasein per ml sample gives satisfactory results with an accuracy of ±5%. Application of a standard addition method also improves the accuracy, but is laborious and less precise.Abbreviations a true enzyme activity - a _s activity determined from standard curve - AU Anson unit - c _A/T relative azocasein concentration (mg azocasein per mg total protein) - r ratio between measured and true enzyme activity - RD relative deviation from true value (%) - RSD relative standard deviation (%) - TCA trichloroacetic acid     

Cosynthesis of erythromycin A N-oxide by mutants ofSaccharopolyspora erythraea blocked in erythromycin production

The production of erythromycin A (1) and free erythronolide B (2) inSaccharopolyspora erythraea BTCC-2 is accompanied by formation of erythromycin A N-oxide (3) and other minor components, the ratio of yields of1 and3 being 97:3. Erythromycin-blocked mutants of type I (impaired in some unidentified steps prior to lactone synthesis) and type II (accumulating only2) cosynthesized both1 and the accompanying metabolites, but the ratio of1 and3 changed to 70:30. In pure cultures of type I, exogenous2 was converted to1 and minor components in ratios typical of the strain BTCC-2, whereas mutants of type II were effective convertors of1 to3.     

Inhibition of Real-Time PCR in DNA Extracts from Aquifer Sediment

Variation in inhibition of real-time PCR was investigated with DNA extracts from 50 aquifer sediment core samples of 5 cm length collected through a 2.5 meter vertical profile across a landfill leachate plume. The inhibition was quantified using an internal control of the green fluorescent protein ( gfp ) gene, which was spiked into the real-time PCR reactions. The inhibition was investigated at two gfp gene concentrations: at 1.7 · 10 ⁷ gfp gene copies/g sediment (5.1 · 10 ⁴ gfp gene copies/PCR reaction) and at 1.7 · 10 ⁵ gfp gene copies/g sediment (5.1 · 10 ² gfp gene copies/PCR reaction). Despite the low TOC content of the sediment (average 0.4 mg C/g dw) the average real-time PCR response was partially inhibited, compared to a reference (pure water), at both high and low gfp concentrations. The relative amplification (reference = 1) was 0.85 ± 0.20 (high) and 0.66 ± 0.23 (low), showing significantly (P < 0.05) stronger inhibition at the lower target gene concentration. The inhibition of the real-time PCR did not show a systematic variation in the vertical profile related to plume position but variations were significant on a small scale of 5–15 cm depth intervals. One of the 50 samples failed to produce a signal with either concentration of the gfp internal control and three other samples inhibited real-time PCR at both high and low gfp concentration. These 4 samples, which were the samples with the highest inhibition, were the only DNA extracts with a visible brown colouration, indicating contents of humic-like substances. Elevated absorbance at 400 nm of these samples also indicated that humic-like substances were responsible for inhibition. However, other factors not associated with either absorbance or TOC may have contributed to the inhibition in less inhibited samples since the variation in real-time PCR response could not be sufficiently explained by absorbance or TOC. The results of this study suggest that an internal control is needed in real-time PCR reactions with DNA from environmental samples due to variation in inhibition to correctly quantify the number of target genes, especially at low target gene concentrations, when dilution of DNA extracts is not practical.     

Chemical constituents isolated from Paeonia lactiflora roots and their neuroprotective activity against oxidative stress in vitro

The methanolic extract of Paeonia lactiflora roots significantly protected primary cultures of rat cortical cells exposed to oxidative stress induced by H₂O₂. Seven monoterpenes, paeonilactone-B (1), paeonilactone-C (2), paeoniflorigenone (3), benzoylpaeoniflorin (4), paeoniflorin (5), oxypaeoniflorin (6) and albiflorin (7), were isolated by bioactivity-guided fractionation and further separation using chromatographic techniques. Among them, compounds 2 and 4 significantly protected primary cultures of rat cortical cells against H₂O₂-induced neurotoxicity.     

专项整治对综合医院抗菌药物使用强度的影响

??????? 目的 探讨抗菌药物临床应用专项整治活动对综合医院住院患者抗菌药物使用强度的影响。方法 以限定日剂量（DDD）为单位,对某综合性医院在实施专项整治前、后住院患者抗菌药物使用强度（AUD）进行统计、分析。结果 专项整治活动降低了住院患者累计AUD值,大环内酯类等药物AUD明显下降,第二代、第三代和第四代头孢菌素和不同管理级别抗菌药物AUD均下降。但还存在用药集中、注射用头孢哌酮钠舒巴坦钠AUD下降不明显等问题。结论 专项整治有效降低了综合医院住院患者AUD,但与卫生行政部门标准仍存在差距,应进一步加强管理。     

Spectral responses and chromatic processing in the dragonfly lamina

The dragonfly Hemicordulia tau has five spectral classes of photoreceptor which drive five lamina monopolars, m1-m5. The monopolars encode spectral information. Here, spectral coding by m2, m4 and m5 are described. m2 is the most sensitive to dim light. m4 and m5 are less sensitive than m2, and so we call them photopic cells. The effects of selective adaptation of receptor inputs to m4 and m5 are unusual. For example, in m4 adaptation of the green receptor suppresses the UV input, but green sensitivity is unaffected, while green adaptation of m5 increases its green sensitivity. In m5 the dark adapted spectral tuning resembles the 520 nm receptor, but on adaptation to 430 nm light this narrows markedly. Adaptation either of green or of UV receptor input to m2 and m4 modifies the time course of responses both to green and to UV, implying that changes in the time courses of monopolar responses with adaptation state do not directly reflect receptor responses (Fig. 2). Finally, the antagonistic surround of m2 is UV sensitive, and of m4 green sensitive (Fig. 3).Abbreviations LMC large monopolar cell - LVF long visual fibre - rf receptive field - SVF short visual fibre     

Synthesis,in vitro and in vivo antitumor and antiviral activity of novel 1-substituted benzimidazole derivatives

Abstract

A novel series of 5-nitro-1H-benzimidazole derivatives substituted at position 1 by heterocyclic rings was synthesized. Cytotoxicity and antiviral activity of the new compounds were tested. Compound 3 was more active than doxorubicin against A-549, HCT-116 and MCF-7. However, compound 3 showed no activity against human liver carcinoma Hep G-2 cell line. Compounds 9 and 17b (E) showed potency near to doxorubicin against the four cell lines. The acute toxicity of compound 9 on liver cancer induced in rats was determined in vivo. Interestingly, it showed restoration activity of liver function and pathology towards normal as compared to the cancer-bearing rats induced by DENA. Compounds 17a (Z), 17b (E) and 18a (Z) were the most promising compounds for their antiviral activity against rotavirus Wa strain.     

Evidence for Anaerobic CH 4 Oxidation in Freshwater Peatlands

This study involved in vitro assays of peat soil to investigate the occurrence, importance and potential mechanism(s) of anaerobic methane oxidation (AOM) in several northern peatlands ranging from ombrotrophic bog to minerotrophic fen. Although strong evidence suggests that AOM is linked to sulfate reduction in marine sediments, very little is known about AOM in freshwater systems such as northern peatlands, which have large methane (CH ₄ ) production and are a significant source of atmospheric CH ₄ . Our results showed a mean net AOM rate of 17 ± 2.6 nmol kg ^{? 1} s ^{? 1} with a maximum rate of 176 nmol kg ^{? 1} s ^{? 1} for a minerotrophic fen in central New York. AOM was demonstrated with three independent methods to verify our results: (a) additions of methanogenic inhibitors, (b) stable isotope enrichment ( ¹³ C-CH ₄ ), and (c) natural abundance stable isotope analysis ( ¹³ C-CH ₄ ). These experiments confirmed that AOM occurs simultaneously with methanogenesis, consumes a significant portion of gross CH ₄ production, and significantly fractionates C isotopes (～ ?127‰). Experiments using a variety of potential electron acceptors demonstrated that Fe(III) and SO₄ ^{2 ?} are not quantitatively important, while the role of NO ₃ ^? is uncertain and deserves more attention. The exact mechanism(s) for AOM in peat soils remains unclear; however the AOM rates reported in this study are similar to those reported for CH ₄ production and aerobic CH ₄ oxidation in northern peatlands, suggesting that AOM may be an important control on CH ₄ fluxes in northern peatland ecosystems.     

Chemical constituents isolated from Polygala japonica leaves and their inhibitory effect on nitric oxide production in vitro

A methanolic extract of dried leaves of Polygala japonica Houtt (Polygalaceae) significantly attenuated nitric oxide production in lipopolysaccharide-simulated BV2 microglia. Five anthraquinones chrysophanol (1), emodin (2), aloe-emodin (3), emodin 8-O-β-D-glucopyranoside (4) and trihydroxy anthraquinone (5), and four flavonoids kaempferol (6), chrysoeriol (7), kaempferol 3-gentiobioside (8) and isorhamnetin (9) were isolated from the methanolic extract using bioactivity-guided fractionation. Among them, compounds 1–4, 6 and 7 showed significant inhibitory effect on lipopolysaccharide-induced nitric oxide production in BV2 microglia at the concentrations ranging from 1.0 to 100.0 μM.     

Synthesis,spectral characterization,and in vitro antibacterial and antifungal activities of novel 1,3-thiazine-2-amines comprising morpholine nucleus

A collection of 4-(4-morpholinophenyl)-6-aryl-6H-1,3-thiazin-2-amines (20–28) were synthesized and their in vitro antimicrobial activity was investigated. Compound 21 against P. aeruginosa, 23 against B. subtilis, 24 against V. cholerae and P. aeruginosa, 26 against S. aureus and B. subtilis, 27 against B. subtilis and E. coli, and 28 against all tested bacterial strains exerted excellent antibacterial activity. Compound 20 against A. flavus and Rhizopus, 21, 26 against Rhizopus, 22, 27 against Mucor, 23 against A. flavus, 24 against both A. flavus and Mucor, 25 against all tested strains, and 28 against Rhizopus and M. gypseum exerted excellent antifungal activity.