Increased flavin synthesis in yeasts utilizing hydrocarbons]

Comparative studies of the process of possible overproduction of flavins by cultures with different flavinogenous activity grown on media with hydrocarbons and glucose have been carried out. The strains with a high flavinogenous activity, Candida guilliermondii and Torulopsis famata O-3, produced more flavins on media containing hydrocarbons than the cultures with a low flavinogenous activity. At a high content of iron in the medium, which is unfavourable for overproduction of riboflavin the rate of flavinogenesis is higher on hydrocarbons than on sugars, especially on alkanes with a longer chain in the strain O-3. Under the conditions of iron deficiency, the activity of flavinogenesis is higher on glucose in the case of both cultures. Iron deficiency in media containing hydrocarbons and their oxygenated derivative (cetyl alcohol, palmitic and acetic acids) has no such effect on the production of flavin by T. famata O-3 as in the glucose containing media. On media with ethanol, overproduction of the vitamin by the strain O-3 obeys the same relationships as on media with glucose. Possible factors that may have effect on the elevated synthesis are discussed.     

Differential survival of male and female partially resistant horn flies (Diptera: Muscidae) on steers treated with permethrin

Males and females from a heterozygous, resistant strain (SR) of the horn fly, Haematobia irritans (L.), were tested for survival until reproductive maturity on steers with ear tags in outdoor, screened enclosures and on steers sprayed on the neck in an indoor isolation room. After 6 d, female SR flies on outdoor steers with one tag had 10 times greater survival than males; almost no SR flies on steers with two ear tags survived. Survival of male and female SR flies on steers sprayed on the neck was reduced during the first 24 h, but not thereafter. Lower survival of males compared with females on treated steers reflected differential survival of the sexes during exposure to treated cloths in a laboratory bioassay. Hair samples from neck, back, rump, and lower legs of steers with ear tags in outdoor pens were tested for toxicity to the SR flies. These bioassays indicated high localization of insecticide on the neck of steers with ear tags.     

Effects of corticotropin releasing hormone on appetitive behaviors.

Corticotropin releasing hormone (CRH) is a 41-residue hypothalamic neuropeptide that has been shown to have potent behavioral effects in animals and has been implicated in clinical disorders in man. This review focuses on those aspects of the behavioral effects of CRH related to food-associated behaviors. The effects of CRH on food intake are compared with its effects on performances maintained by food presentation, and contrasted with the effects of CRH on performances maintained by other events. The effects of CRH antagonists and drugs that interact with the behavioral effects of CRH are also reviewed, particularly with respect to their direct effects on food intake. Lastly, data assessing the effects of CRH administration on central neurotransmitter levels are presented and compared with levels seen in clinical populations. The effect of CRH on food intake seen in animals is consistent with a putative role for CRH in clinical syndromes where appetite suppression is apparent. Since some of the effects of CRH on food intake are subject to pharmacological intervention, strategies directed at peptidergic mechanisms of psychiatric disorders should be explored.     

Effects of kaolin particle film on oviposition,larval mining,and infestation of cotton by pink bollworm (Lepidoptera: Gelechiidae)

We tested effects of kaolin particle film on oviposition, larval mining, and infestation of cotton by pink bollworm, Pectinophora gossypiella (Saunders) (Lepidoptera: Gelechiidae), in the laboratory, greenhouse, and field. In laboratory choice tests, females laid seven times more eggs on untreated bolls than on bolls treated with kaolin. When neonates were put on bolls in the laboratory, each boll with a treated and untreated half, larvae and mines were found 24 h later on the untreated half but not on the treated half. In oviposition choice tests with whole plants in the greenhouse, females laid four times more eggs on untreated plants than on treated plants and the number of eggs on bolls was five times higher for untreated plants than for treated plants. Kaolin treatments altered the distribution of eggs among plant parts, with untreated bolls receiving a higher percentage than treated bolls, whereas the opposite occurred for petioles. In field tests, treatment with kaolin alone reduced the proportion of bolls infested with pink bollworm, but a mixture of kaolin and the pyrethroid lambda-cyhalothrin was most effective. The results suggest that kaolin particle film may be useful against pink bollworm, particularly in conjunction with other control tactics.     

Thoracic pressure and nasal patency

Maximum nasal flow rate in the right and left nostrils was simultaneously determined during expiration with the help of two flowmeters in 10 healthy subjects in different postures and in two patients, one with Horner's syndrome and the other with facial palsy. It was found that pressure on the hemithorax from any surface (i.e., lateral, anterior, posterior, or superior) leads to reduced patency of the ipsilateral nostril but increased patency of the nostril on the opposite site. In the patient with Horner's syndrome, the nostril on the affected side remained blocked even on compression of the opposite hemithorax, and in the one with facial nerve palsy, the nostril on the affected side remained patent despite compression of the hemithorax on that side. The findings suggest that compression of hemithorax leads to changes in the congestion of the nasal mucosa that may be mediated through autonomic nerves.     

A comparison of features and the microbial constitution of the fresh feces of pigs fed diets supplemented with or without dietary microbes

The features and the constitution of the microbial population of fresh feces were compared between pigs fed a diet supplemented with dietary microbes and pigs given nonsupplemented diets. The former were reared on farm C and the latter on farms A and B. The concentrations of ammonia-N, indole, and skatole of fresh feces were not significantly different between pigs reared on farm C and those raised on farms A and B, but the concentrations of ammonia-N and the skatole of fresh feces were significantly different between pigs reared on farms A and B. The total VFA (volatile fatty acids) concentration of fresh feces in pigs on farm C was slightly lower than in those on farms A and B. Moreover, the molar proportion of the acetic acid in feces in pigs on farm C was lower; inversely, that of propionic and butyric acids was higher in comparison with those on farms A and B. No differences were evident in the total viable counts of feces among pigs reared on the three different farms. Clostridium perfringens was abundant in feces of pigs raised on farms A and B, but it was not detected in pigs reared on farm C. Megasphaerae, bifidobacteria, and clostridia except for C. perfringens were more abundant in the feces of pigs fed a diet supplemented with dietary microbes on farm C, compared with pigs given the nonsupplemented diets on farms A and B.     

高山森林林窗和生长基质对苔藓植物氮和磷含量的影响

苔藓在森林生态系统养分富集和循环方面有重要作用,苔藓植物在氮磷循环中的作用可能受到森林更新和生长基质的影响.为理解苔藓在森林生态系统养分循环中的作用,研究了高山森林不同位置(林窗中心、林窗边缘、林下)和不同生长基质(活立木、倒木、枯立木、大枯枝、根桩、地表)上的苔藓植物氮磷含量.结果表明:地表苔藓氮含量(3.12 mg·g^-1)显著低于其他生长基质上的苔藓,尽管枯立木附生苔藓氮含量高达17.41 mg·g^-1,但倒木、大枯枝、枯立木和活立木苔藓氮含量差异不显著;最高(1.09 mg·g^-1)和最低(0.61 mg·g^-1)的磷含量分别出现在森林地表和枯立木的苔藓,且森林地表的苔藓磷含量显著高于其他生长基质上的苔藓,但倒木、大枯枝、根桩和活立木上的苔藓磷含量差异不显著.林窗位置显著影响了倒木和大枯枝上的苔藓氮、磷含量,林窗内倒木和大枯枝上的苔藓氮、磷含量显著高于林窗边缘.粗木质残体的类型、腐烂等级对苔藓氮、磷含量的影响存在差异,两者交互作用的影响显著;第Ⅴ腐烂等级倒木上的苔藓氮含量显著高于其他腐烂等级;第Ⅲ腐烂等级大枯枝上的苔藓氮含量显著高于其他腐烂等级;第Ⅱ腐烂等级倒木上的苔藓磷含量显著高于其他腐烂等级;第Ⅳ腐烂等级枯立木上的苔藓磷含量显著高于其他腐烂等级.可见,森林林窗更新和粗木质残体腐解过程会影响苔藓植物的氮、磷含量,同时影响森林生态系统的养分循环过程.     

Reduced expression of β2 integrin genes in rat peripheral leukocytes by inhibiting postprandial hyperglycemia

β(2) integrins (CD11s/CD18) promote the attachment of leukocytes to vascular endothelial cells. We performed in this study sucrose loading to rats with moderate postprandial hyperglycemia with/without once-daily dosing of the α-glucosidase inhibitor, miglitol, for 4 days under 4-h fasting conditions. The streptozotocin (STZ)-treated rats showed moderate postprandial hyperglycemia on days 1 and 4. The gene expression was higher for CD11a with fasting and 3-h postprandial on day 1, and with fasting on day 4, for CD11b with fasting on day 1 and 3-h postprandial on day 4, and for CD18 with fasting on days 1 and 4 in peripheral leukocytes from the STZ-treated rats than in peripheral leukocytes from the saline-treated rats. Miglitol reduced postprandial hyperglycemia and the gene expression of CD11a with fasting and of CD11b 3-h postprandial on day 4. These results indicate that inhibiting postprandial hyperglycemia reduced the mRNA expression of β(2) integrins in peripheral leukocytes of moderately postprandial hyperglycemic rats.     

覆盖旱作水稻群体发育特征分析

通过田间试验,研究了不同覆盖旱作水稻处理与水作处理水稻的群体生育特征。结果表明,旱作水稻营养生长期较水作长,叶片变短、变窄,群体LAI变小,光合生产能力下降,最终粒数变少、粒重变轻,不同旱作处理之间表现为地膜覆盖旱作处理分蘖发生多,成穗率低,穗分化和籽粒形成与灌浆时间缩短,半腐解秸秆覆盖旱作和裸地旱作分蘖发生少,成穗率高,穗分化时间缩短,籽粒形成与灌浆的时间延长,产量表现为水作处理>地膜覆盖旱作>半腐解秸秆覆盖旱作>裸地旱作。     

Repellency of a kaolin particle film,Surround, and a mineral oil,Sunspray oil,to silverleaf whitefly (Homoptera: Aleyrodidae) on melon in the laboratory

Surround, a kaolin-based particle film formulation, and Sunspray oil, a mineral oil, were evaluated alone or in combination in choice and no-choice laboratory assays on melon leaves for repellency to adults of the silverleaf whitefly, Bemisia argentifolii Bellows & Perring. In no-choice tests, the number of adults and eggs on leaves did not significantly differ among the three treatments and the water control when materials were applied to either the tipper or lower leaf surface. Significantly fewer adults and eggs were found on treated leaves compared with water when materials were applied to both leaf surfaces. Application of Surround did not affect the oviposition pattern, with 80.2-88.5% eggs oviposited on lower surface. However, whiteflies oviposited more eggs (53.1-63.8%) on the upper compared with the lower surface when Sunspray oil or Surround + Sunspray oil was applied on the lower leaf surface and both leaf surfaces. When whiteflies were allowed to choose among leaves treated with different materials on the same leaf surface(s), significantly fewer adults and eggs were found on treated leaves compared with water-treated leaves, and more adults and eggs were found on leaves when the materials were applied to tipper versus lower or both surfaces. Leaves treated with materials on both leaf surfaces had fewer whiteflies compared with leaves treated on the upper or lower surface. When whiteflies were allowed to choose among leaves treated with materials versus water-treated leaves in a 6:3 or an 8:1 ratio, significantly fewer adults and eggs were found on leaves treated with treatment materials compared with water, regardless of which leaf surface(s) were treated. No significant synergistic or additive effect was detected in Surround + Sunspray oil compared with either material used separately.     

Chemokinetic accumulation of human neutrophils on immune complex-coated substrata: analysis at a boundary

The locomotory behavior of human blood neutrophil leukocytes was studied at a boundary between two surfaces with different chemokinetic properties. This was achieved by time-lapse cinematography of neutrophils moving on coverslips coated with BSA, then part-coated with immune complexes by adding anti-BSA IgG with a straight-line boundary between the BSA and the immune complexes. Cell locomotion was filmed in microscopic fields bisected by the boundary, and kinetic behavior was assessed by comparing speed (orthokinesis), turning behavior (klinokinesis), and the rate of diffusion of the cells on each side of the boundary, using a recently described mathematical analysis of kinesis. In the absence of serum or complement, the proportion of motile cells and their speed and rate of diffusion were greater on BSA than on antiBSA, but there was no consistent difference in turning behavior between cells on the two surfaces. The immune complexes were therefore negatively chemokinetic in comparison with BSA, and this resulted from a negative orthokinesis with little or no contribution from klinokinesis. As would be predicted theoretically, this resulted in gradual accumulation of cells on the immune complexes even in the absence of a chemotactic factor. In further studies, a parallel plate flow chamber was used to show that, under conditions of flow, neutrophils accumulated much more rapidly on a surface coated with BSA- anti-BSA than on BSA alone. Moreover, neutrophils on immune complex- coated surfaces lost their ability to form rosettes with IgG-coated erythrocytes. This suggests that neutrophils on immune complex-coated surfaces redistribute their Fc receptors (RFc gamma) to the under surface, and that the lowered speed of locomotion is due to tethering of neutrophils by substratum-bound IgG-Fc.     

Cell cultivation on porous titanium implants with various structures

The paper presents data on the cultivation of human dermal fibroblasts and rabbit mesenchymal stromal cells on two types of porous titanium implants, i.e., those with irregular pores formed by pressed titanium particles and those with regular pores formed by the cohesion of one-size titanium particles inside the implant. The goal of this study was to determine what type of titanium implant porosity ensured its strongest interaction with cells. Cells were cultivated on implants for 7 days. During this period, they formed a confluent monolayer on the implant surface. Cells grown on titanium implants were monitored by scanning electron microscopy. Fibroblasts interaction with implants depended on the implant porosity structure. On implants with irregular pores cells were more spread. On implants with regular pores fibroblasts enveloped particles and were only occasionally bound with neighboring particles by small outgrowths. There was no tight interaction of particles inside the implant. In implants formed by pressed particles, cells grow not only on surface, but also in the depth of the implant. Thus, we suppose that a tighter interaction of cells with the titanium implant and, supposedly, tissues with the implant in the organism will take place in the variant when the implant structure is formed by pressed titanium particles, i.e., cellular interaction was observed inside the implant. In implants with irregular pores, cells grew both on the surface and in the depth. Thus, cells exhibited more adequate interactions with irregular pore titanium implants in vitro and hopefully the same interaction will be true in tissues after the implantation of the prosthesis into the organism.     

Cladistic information in phylogenetic definitions and designated phylogenetic contexts for the use of taxon names

A phylogenetic definition of a taxon name associates that name with a clade through its reference to a particular ancestor and all of its descendants. Depending on one's perspective, phylogenetic definitions name either clades on the one true, but unknown, phylogeny, or components on cladograms (clades on hypotheses regarding the true phylogeny). Phylogenetic definitions do not contain enough information to identify components without a reference cladogram. As a result, (1) if clades are equated with components on cladograms, a phylogenetic definition may associate a taxon name with different clades on different cladograms, and (2) the inclusiveness, diagnostic synapomorphies, and distribution in time and space of the clade with a particular name can differ markedly depending on the phylogenetic hypothesis one chooses to adopt. This potentially unacceptable lability in the clade to which a name refers can be avoided by using a taxon name in conjunction with only phylogenetic hypotheses on which specific taxa are related in a particular fashion. This designated phylogenetic context can be described in an n-taxon statement that would be appended to the phylogenetic definition. Use of the taxon name would be considered inappropriate in conjunction with cladograms on which the relationships contradict those in the n-taxon statement. Whereas phylogenetic definitions stabilize the meaning of taxon names, designated phylogenetic contexts would stabilize the usage of those names.     

Alpha-conotoxin residues that interact at close range with gamma-tyrosine-111 and mutant delta-tyrosine-113 on the Torpedo nicotinic acetylcholine receptor

The alpha-conotoxins MI and GI display stronger affinities for the alphagamma agonist site on the Torpedo californica electrocyte nicotinic acetylcholine receptor (ACHR) than for the alphadelta agonist site, while alpha-conotoxin SI binds with the same affinity to both sites. Prior studies reported that the arginine at position 9 on GI and the tyrosine at position 111 on the receptor gamma subunit were responsible for the stronger alphagamma affinities of GI and MI, respectively. This study was undertaken to determine if the alpha-conotoxin midchain cationic residues interact with Torpedo gammaY111. The findings show that lysine 10 on MI is responsible for the alphagamma selectivity of MI and confirm the previously reported importance of R9 on GI and on the SI analogue, SIP9R. The results also show that gammaY111 contributes substantially to the selective alphagamma high affinity of all three peptides. Double-mutant cycle analyses reveal that, in the alphagamma site, K10 on MI and R9 on SIP9R interact with the aromatic ring of gammaY111 to stabilize the high-affinity complex, while in contrast, R9 on GI does not. The substitution of Y for R at position 113 on the delta subunit converts the alphadelta site into a high-affinity site for MI, GI, and SIP9R through the interacting of deltaY113 with K10 on MI and with R9 on both GI and SIP9R. The overall data show that the residues in the two sites with which MI interacts, other than at gamma111/delta113, are either the same or similar enough to exert equivalent effects on MI, indicating that MI binds in the same orientation at the alphagamma and alphadelta sites. Similar findings show that SIP9R probably also binds in the same orientation at the wild-type alphagamma and alphadelta sites. The finding that R9 on GI interacts closely with deltaR113Y but not with gammaY111 means that GI binds in different orientations at the alphagamma and alphadelta sites. This report also discusses the molecular basis of the difference in the MI high-affinity sites on Torpedo and embryonic mouse muscle ACHRs.     

基于SCI文献分析我国菌根学研究现状和发展方向

基于美国科学情报研究所(ISI)科学引文索引(Science Citation Index, SCI)数据库, 对1989~2007年期间我国发表的菌根研究论文进行检索, 并采用文献计量方法对所获资料进行统计和趋势分析。结果表明, 1989~2007年间, 我国菌根学研究呈现不断上升趋势, 尤其是2000年之后, 增长速度明显加快。但只有5.22%的论文发表于影响因子大于5的刊物, 在研究深度上仍需进一步加强。半数以上的研究论文与丛枝菌根研究有关, 研究重点主要集中在菌根对植物的生理效应, 菌根与植物抗性     

Differences between oligotrophic communities resulting from old-field succession in relation to bedrock

Dehesa ecosystems on granite and on slate clearly differ in soil characteristics. Our aim was to find out whether floristic composition differed too.we selected an equal number of plots, on both granite and slate, in different successional stages of development and at various ages after field abandonment (the youngest 15–20 years). Plots with rock-outcrops, which had never been cultivated, were also included in the study.The results showed that floristic differences between granite and slate communities were not detectable in the younger successional stages. However, they showed up with time and on stabilized grasslands became significant. But on plots with rock-outcrops the differences were not observable. This was undoubtedly influenced by the peculiar features of these plots, characterised by poor arid soils and surface parent material. In fact they did not show significant differences in the analysed soil parameters either.Species diversity and biomass showed a similar pattern of differences to floristic composition. The highest species diversity was found on plots with lower biomass (the youngest ones). The lowest biomass in conjunction with quite low species diversity was found on plots with rock-outcrops, which again is consistent with their peculiar features.     

The roles of ascospores and conidia of Pyrenopeziza brassicae in light leaf spot epidemics on winter oilseed rape (Brassica napus) in the UK

Ascospores of Pyrenopeziza brassicae were produced in apothecia (cup‐shaped ascomata) on oilseed rape debris. The conidia, which were morphologically identical to the ascospores, were produced in acervular conidiomata was greater than for lesions caused by ascospores. In June 2000, on the ground under a crop with light on the surface of living oilseed rape tissues. Ascospores were more infective than conidia on oilseed rape leaves. The proportion of lesions caused by conidia located on leaf veins leaf spot, numbers of petioles with apothecia decreased with increasing distance into the crop from the edge of pathways. Air‐borne ascospores of P. brassicae were first collected above debris of oilseed rape affected with light leaf spot on 5 October 1998 and 18 September 1999,12 or 23 days, respectively, after the debris had been exposed outdoors. P. brassicae conidia were first observed on leaves of winter oilseed rape on 6 January 1999 and 15 February 2000, respectively, after plots had been inoculated with debris in November 1998 and October 1999. In 1991/92, numbers of ascospores above a naturally infected crop were small from January to April and increased in June and July. P. brassicae conidia were first observed in February and the percentage plants with leaves, stems or pods with light leaf spot increased greatly in May and June. In 1992/93, in a crop inoculated with debris, numbers of airborne ascospores were small from October to January and increased from April to June. P. brassicae conidia were first observed on leaves in late November and light leaf spot was seen on stems and pods in March and June 1993, respectively.     

Estrogen effects on platelet-activating factor and platelet-activating factor acetylhydrolase activity in rat uterus during the late stages of pregnancy.

The platelet-activating factor (PAF) concentration of the uterus spontaneously increased during pregnancy. When 17alpha-ethynylestradiol (0.25 mg/kg) was administered subcutaneously to pregnant rats for 3 days starting on Day 17 of pregnancy, some rats delivered prematurely on Day 20. However, none of the vehicle-treated (80% dimethylsulfoxide and 20% ethanol) pregnant rats delivered prematurely. The PAF concentration of the uterus in pregnant rats treated with 17alpha-ethynylestradiol was significantly higher than in those treated with vehicle on Days 19 and 20. On the other hand, the specific activity of uterine PAF-acetylhydrolase (PAF-AH) in pregnant rats treated with 17alpha-ethynylestradiol was significantly lower than in those treated with vehicle on Days 19 and 20, and the plasma PAF-AH activity in pregnant rats treated with estrogen was also significantly lower than in treated with vehicle on Days 18, 19, and 20. These findings indicate that estrogen increases PAF concentrations in the rat uterus, and this was correlated with a decrease in PAF-AH in the uterus and plasma. The increase in PAF concentrations in the uterus may be related to premature delivery and labor caused by PAF's known effect on myometrial contraction.     

Efectos del uso del 17 β-estradiol y la genisteína en la enfermedad de Alzheimer en mujeres con menopausia

The use of 17 β-estradiol and genistein in women with menopause helps in the reduction of vasomotor symptoms and cognitive improvement. There is evidence on the use of certain flavonoids such as genistein, which has a potentially neuroprotective role in neurodegenerative diseases such as Alzheimer's. Scientific evidence on the effects of phytoestrogens and genistein during menopause and their effect on cognition are scarce, however, in the present review it was found that the intervention with 17 β-estradiol has positive effects on cognition in women with Alzheimer's disease. In addition, the use of genistein, daidzein or any supplement based on isoflavones may influence vasomotor symptoms. 17 β-estradiol supplements in women in early menopause and with some degree of cognitive impairment may have beneficial effects.