A three‐dimensional numerical model investigation of the impact of submerged macrophytes on flow dynamics in a large fluvial lake

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Candida vanriji nova species a new yeast from Swedish soils

Summary A new species of Candida is described: it was isolated from soils of Sweden. This species is named Candida vanriji nova species in honour of Mrs. N. W. Kreger-Van Rij of the C. B. S. of Delft.     

The production of caproic and butyric acids by the methane fermentation of ethyl alcohol

Summary A fermentation of ethyl alcohol under the influence of Methanobacterium Omelianskii and an associated spore-forming bacterium is described in which the alcohol is converted into acetic, butyric and caproic acids. At the same time there occurs a reduction of carbon dioxide to methane. The data provide direct evidence for the formation of butyric and caproic acids by a condensation of a C₂-compound which probably is acetaldehyde.Division of Plant Nutrition, University of California, Berkeley, California. The author takes great pleasure in expressing his indebtedness to Prof. A. J. Kluyver for extending the hospitality of the Delft laboratory and for his interest, encouragement and advice during the progress of the work.     

The Growth ofSaccharomycopsis Guttulata

Summary A medium containing an extract of rabbit stomach contents for the growth ofSaccharomycopsis guttulata (Robin) Schi?nning is described. Growth characteristics and tentative fermentation and carbon assimilation patterns are reported. Nitrate assimilation could not be determined with the media available. Sporulation has been observed on artificial media. The growth promoting substance is heat stable and non dialysable, it appears to be destroyed by precipitation of protein from the active extract solution. The possibility of transferringS. guttulata to the genusSaccharomyces and discarding the genusSaccharomycopsis is discussed. A culture ofSaccharomycopsis guttulata has been deposited at the Centraalbureau voor Schimmelcultures, Delft.     

Saccharomyces vafer andS. inconspicuus spp.n.

During the re-examination of cultures deposited with the Yeast Division of the Centraalbureau voor Schimmelcultures, Delft, representatives of two hitherto undescribed species of the genusSaccharomyces were encountered.     

Die systematische Stellung vonTheligonum

Ohne ZusammenfassungDen Anstoß zu der vorliegenden Arbeit gab Herr Dr. P.Kooiman, Delft, durch eine briefliche Anfrage, ob es möglich wäre, fürTheligonum einen besseren Platz zu finden als bei denMyrtales. An dieser Stelle möchte ich ihm für seine Anregung und für die Zusendung fixierten Materials vonTheligonum herzlich danken.Ferner bin ich Herrn Prof. Dr. F.Ehrendorfer, Direktor des Botanischen Institutes der Universität Wien, für sein lebhaftes Interesse an dieser Arbeit und für alle mir gewährten Hilfsmittel des Institutes zu besonderem Dank verpflichtet.     

The isolation ofChromatium Okenii and its behaviour in different media

Summary An enrichment culture ofChromatium Okenii, obtained from mud of a ditch at Delft, was used for isolation of this species. The bacteria of the strain, isolated by making 5 successive shake cultures in an agar medium were, however, less than half the size ofChr. Okenii when cultivated under the same conditions as the bacteria in the original culture.By variation of the culture conditions for the pure strain, it appeared that in a mineral medium containing fairly high concentrations of sodium thiosulphate and fairly low concentrations of sodium malate, bacteria developed of nearly the same size as present in the enrichment culture. This supports the view ofWinogradsky that media of this type offer the most natural conditions to purple sulphur bacteria.It is, therefore, evident thatChr. Okenii is a highly pleomorphic species, and the consequences hereof for the differentiation of species within the genusChromatium were discussed.     

Genetic markers on BTA14 predictive for residual feed intake in beef steers and their effects on carcass and meat quality traits

With the high cost of feed for animal production, genetic selection for animals that metabolize feed more efficiently could result in substantial cost savings for cattle producers. The purpose of this study was to identify DNA markers predictive for differences among cattle for traits associated with feed efficiency. Crossbred steers were fed a high‐corn diet for 140 days and average daily feed intake (ADFI), average daily gain (ADG), and residual feed intake (RFI) phenotypes were obtained. A region on chromosome 14 was previously associated with RFI in this population of animals. To develop markers with the highest utility for predicting an animal's genetic potential for RFI, we genotyped additional markers within this chromosomal region. These polymorphisms were genotyped on the same animals (n = 1066) and tested for association with ADFI, ADG and RFI. Six markers within this region were associated with RFI (P ≤ 0.05). After conservative correction for multiple testing, one marker at 25.09 Mb remained significant (P = 0.02) and is responsible for 3.6% of the RFI phenotypic variation in this population of animals. Several of these markers were also significant for ADG, although none were significant after correction. Marker alleles with positive effects on ADG corresponded to lower RFI, suggesting an effect increasing growth without increasing feed intake. All markers were also assessed for their effects on meat quality and carcass traits. All of the markers associated with RFI were associated with adjusted fat thickness (AFT, P ≤ 0.009) and three were also associated with hot carcass weight (HCW, P ≤ 0.003). Marker alleles associated with lower RFI were also associated with reduced AFT, and if they were associated for HCW, the effect was an increase in weight. These markers may be useful as prediction tools for animals that utilize feed more efficiently; however, validation with additional populations of cattle is required.     

Stimulatory effect of cycloheximide on the infection of hyacinth and tulip bulbs byPenicillium sp.

Treating scooped out bulbs of hyacinths (Hyacinthus orientalis L. cv. ‘Lady Derby’, cv. ‘Pink Pearl’, cv. ‘Delft Blue’) and tulips (Tulipa gesneriana hort. cv. ‘Oxford’) with cycloheximide stimulated strongly the infection of the tissues of the bulbs byPenicillium sp. The possible mechanism of such an activity of cycloheximide is discussed.     

Procalcitonin as a prognostic marker in patients with acute myocardial infarction

Background: Procalcitonin is involved in the inflammatory response and is associated with adverse prognosis in certain conditions.

Aims: To investigate the association between procalcitonin and major adverse cardiac events (MACE), left ventricular (LV) function and remodelling following acute myocardial infarction (AMI).

Methods: Plasma procalcitonin was measured in 977 patients with AMI. Subjects were followed for MACE (median 671 days). A subgroup underwent echocardiography at discharge and follow-up LV function and volume assessment.

Results: Procalcitonin was associated with MACE on uni- and multivariable analysis. Kaplan–Meier assessment revealed an adverse outcome in subjects with procalcitonin above the median. Procalcitonin was related to markers of LV dysfunction and remodelling.

Conclusion: Procalcitonin is associated with MACE, LV dysfunction and remodelling post-AMI.     

Morphological and chemical components of resistance to pod borer, Helicoverpa armigera in wild relatives of pigeonpea

Host plant resistance is an important component for minimizing the losses due to the pod borer, Helicoverpa armigera, which is the most devastating pest of pigeonpea. An understanding of different morphological and biochemical components of resistance is essential for developing strategies to breed for resistance to insect pests. Therefore, we studied the morphological and biochemical components associated with expression of resistance to H. armigera in wild relatives of pigeonpea to identify accessions with a diverse combination of characteristics associated with resistance to this pest. Among the wild relatives, oviposition non-preference was an important component of resistance in Cajanus scarabaeoides, while heavy egg-laying was recorded on C. cajanifolius (ICPW 28) and Rhynchosia bracteata (ICPW 214). Accessions belonging to R. aurea, C. scarabaeoides, C. sericeus, C. acutifolius, and Flemingia bracteata showed high levels of resistance to H. armigera, while C. cajanifolius was as susceptible as the susceptible check, ICPL 87. Glandular trichomes (type A) on the calyxes and pods were associated with susceptibility to H. armigera, while the non-glandular trichomes (trichome type C and D) were associated with resistance to this insect. Expression of resistance to H. armigera was also associated with low amounts of sugars and high amounts of tannins and polyphenols. Accessions of wild relatives of pigeonpea with non-glandular trichomes (type C and D) or low densities of glandular trichomes (type A), and high amounts of polyphenols and tannins may be used in wide hybridization to develop pigeonpea cultivars with resistance to H. armigera. Handling editor: Robert Glinwood     

Association between temperament related traits and single nucleotide polymorphisms in the serotonin and oxytocin systems in Merino sheep

Animal temperament is defined as the consistent behavioral and physiological differences that are seen between individuals in response to the same stressor. Neurotransmitter systems, like serotonin and oxytocin in the central nervous system, underlie variation in behavioral traits in humans and other animals. Variations like single nucleotide polymorphisms (SNPs) in the genes for tryptophan 5-hydroxylase (TPH2), the serotonin transporter (SLC6A4), the serotonin receptor (HTR2A), and the oxytocin receptor (OXTR) are associated with behavioral phenotype in humans. Thus, the objective of this study was to identify SNPs in those genes and to test if those variations are associated with the temperament in Merino sheep. Using ewes from the University of Western Australia temperament flock, which has been selected on emotional reactivity for more than 20 generations, eight SNPs (rs107856757, rs107856818, rs107856856 and rs107857156 in TPH2, rs20917091 in SLC6A4, rs17196799 and rs17193181 in HTR2A, and rs17664565 in OXTR) were found to be distributed differently between calm and nervous sheep. These eight SNPs were then genotyped in 260 sheep from a flock that has never been selected on emotional reactivity, followed by the estimation of the behavioral traits of those 260 sheep using an arena test and an isolation box test. We found that several SNPs in TPH2 (rs107856757, rs107856818, rs107856856 and rs107857156) were in strong linkage disequilibrium, and all were associated with behavioral phenotype in the nonselected sheep. Similarly, rs17196799 in HTR2A was also associated with the behavioral phenotype.     

Induction of ajmalicine formation and related enzyme activities in Catharanthus roseus cells: effect of inoculum density

In Catharanthus roseus cell cultures the time courses of four enzyme activities, tryptophan decarboxylase (TDC), strictosidine synthase (SSS), geraniol-10-hydroxylase (G10H) and anthranilate synthase (AS), and alkaloid accumulation were compared under two different culture conditions (low-inoculum density and high-inoculum density on induction medium) and a control on growth medium. In growth medium a transient increase in TDC activity was first observed after which G10H reached its maximum activity; only tryptamine accumulated, no ajmalicine could be detected. Apparently, a concerted induction of enzyme activities is required for ajmalicine formation. Cells inoculated in induction medium showed such a concerted induction of AS, TDC and G10H activities. After 30 days the low-density culture had accumulated six times more ajmalicine (in moles/g) than the high-density culture. Thus, increase in biomass concentration (high-density cultures) did not enhance the total alkaloid production. The major differences observed in enzyme levels between high-and low-density cultures were in the AS and TDC activities, which were two to three times higher in the low-density culture, indicating that there is a positive correlation between ajmalicine formation and AS and TDC activities.Biotechnology Delft Leiden, Project Group Plant Cell Biotechnology Correspondence to: R. Verpoorte     

Role of nitric oxide in the reperfusion induced injury in hyperthyroid rat hearts

We recently reported that hyperthyroidism affects the heart response to ischemia/reperfusion. A significant tachycardia during reperfusion was associated with an increase in the oxidative stress of hearts from T₃-treated animals. In the present study we checked the possible role of nitric oxide (NO) in this major stress induced by the hyperthyroid state. We compared the functional recovery from ischemia/reperfusion of Langendorff preparations from euthyroid (E) and hyperthyroid (H, ten daily intraperitoneal injections of T₃, 10 μg/100 g body weight) rats, in the presence and in the absence of 0.2 mM N^ω-nitro-L-arginine (L-NNA). At the end of the ischemia/reperfusion protocol (10 min preischemic perfusion, 20 min global ischemia, 30 min reperfusion) lipid peroxidation, antioxidant capacity (C_A) and susceptibility to in vitro oxidative stress were determined on heart homogenates. The main effect of hyperthyroidism on the reperfusion functional response was confirmed to be a strong tachycardic response (154% recovery at 25 min reperfusion) accompanied by a low recovery in both left ventricular diastolic pressure (LVDP) and left ventricular dP/dt_max. This functional response was associated with a reduction in C_A and an increase in both lipid peroxidation and susceptibility to oxidative stress. Perfusion of hearts with L-NNA per se had small but significant negative chronotropic and positive inotropic effects on preischemic performance of euthyroid rat hearts only. More importantly, L-NNA perfusion completely blocked the reperfusion tachycardic response in the hyperthyroid rats. Concomitantly, myocardium oxidative state (lipid peroxidation, C_A and in vitro susceptibility to oxidative stress) of L-NNA perfused hearts was similar to that of E animals. These results suggest that the higher reperfusion-induced injury occurring in hyperthyroid animals is associated with overproduction of nitric oxide.     

Gelsolin rs1078305 and rs10818524 polymorphisms were associated with risk of oral squamous cell carcinoma in a Chinese Han population

Background: Gelsolin (GSN) is one of the most abundant actin-binding proteins, and is involved in cancer development and progression.

Patients and methods: A hospital-based case-control study including 201 patients with OSCC and 199 healthy controls was conducted. Seventeen single-nucleotide polymorphisms (SNPs) of GSN were investigated by Sequenom Mass ARRAY and iPLEX-MALDI-TOF technology.

Results: Through comparison of the 17 SNPs on GSN gene between the two groups, SNP rs1078305 and rs10818524 were verified to be significantly associated with an increased risk of OSCC. For GSN rs1078305, the TT genotype was associated with increased risk for OSCC (OR?=?1.92, 95% CI?=?1.11–3.32, p?=?0.028). CT/TT variants were also associated with increased risk for OSCC compared to the CC genotype (OR?=?1.83, 95% CI?=?1.25–3.84, p?=?0.032).

Conclusion: The rs1078305 and rs10818524 SNPs of GSN were associated with increased risk for OSCC development in a Chinese Han population.     

MC1R variation and melanoma risk in the Swedish population in relation to clinical and pathological parameters

The genetic background of cutaneous malignant melanoma (CMM) includes both germ line aberrations in high‐penetrance genes, like CDKN2A, and allelic variation in low‐penetrance genes like the melanocortin‐1 receptor gene, MC1R. Red‐hair colour associated MC1R alleles (RHC) have been associated with red hair, fair skin and risk of CMM. We investigated MC1R and CDKN2A variation in relation to phenotype, clinical factors and CMM risk in the Swedish population. The study cohort consisted of sporadic primary melanoma patients, familial melanoma patients and a control group. An allele‐dose dependent increase in melanoma risk for carriers of variant MC1R alleles (after adjusting for phenotype), with an elevated risk among familial CMM patients, was observed. This elevated risk was found to be significantly associated with an increased frequency of dysplastic nevi (DN) among familial patients compared to sporadic patients. MC1R variation was found to be less frequent among acral lentiginous melanomas (ALM) and dependent on tumour localisation. No association was found between CDKN2A gene variants and general melanoma risk. Two new variants in the POMC gene were identified in red haired individuals without RHC alleles.     

Host race formation in the leaf-mining moth Acrocercops transecta (Lepidoptera: Gracillariidae)

Genetic differentiation in ecological traits plays an important role in the reproductive isolation of phytophagous insects. The present study aims to elucidate the genetic changes involved during the process of host shifts, by combining analyses for (1) host adaptations, (2) pre‐ and postmating isolation, and (3) phylogeney among populations, using a leaf‐mining moth, Acrocercops transecta. This species is associated with Juglans ailanthifolia and Lyonia ovalifolia. Transplantation of the larvae demonstrated that the Juglans‐associated population completely failed to survive on Lyonia, whereas the Lyonia‐associated population survived on Juglans as well as on Lyonia. Females of respective host‐associated populations oviposited on their natal host plant only. An mtDNA‐based phylogeny clearly separated the Lyonia‐associated population from the Juglandaceae‐associated population, and indicated that the Lyonia‐associated population once evolved from the Juglandaceae‐associated population. These results indicate that the processes of host shifting from juglandaceous species to Lyonia involved genetic changes both in larval ability to use host plants and in host preference of females. The derived Lyonia‐associated population has retained the potential to assimilate the ancestral host, Juglandaceae. Mating between the two host‐associated populations was successful for both directions of crossing, and there were no significant differences in egg hatchability between hybrids and control crosses. No adults emerged when the F₁ hybrid larvae were maintained on Lyonia; however, on Juglans the F₁ hybrid larvae grew to adulthood as well as in the control, suggesting a lack of genomic incompatibilities between the two host‐associated populations. In conclusion, the results showed that the two host‐associated populations are host races that are partially reproductively isolated, and that the differences in performance and preference function as strong barriers against gene flow between the host races. © 2008 The Linnean Society of London, Biological Journal of the Linnean Society, 2008, 93 , 135–145.     

Susceptibility loci for metabolic syndrome and metabolic components identified in Han Chinese: a multi‐stage genome‐wide association study

Metabolic syndrome (MetS), a cluster of metabolic disturbances that increase the risk for cardiovascular disease and diabetes, was because of genetic susceptibility and environmental risk factors. To identify the genetic variants associated with MetS and metabolic components, we conducted a genome‐wide association study followed by replications in totally 12,720 participants from the north, north‐eastern and eastern China. In combined analyses, independent of the top known signal at rs651821 on APOA5, we newly identified a secondary triglyceride‐associated signal at rs180326 on BUD13 (P_combined = 2.4 × 10⁻⁸). Notably, by an integrated analysis of the genotypes and the serum levels of APOA5, BUD13 and triglyceride, we observed that BUD13 was another potential mediator, besides APOA5, of the association between rs651821 and serum triglyceride. rs671 (ALDH2), an east Asian‐specific common variant, was found to be associated with MetS (P_combined = 9.7 × 10⁻²²) in Han Chinese. The effects of rs671 on metabolic components were more prominent in drinkers than in non‐drinkers. The replicated loci provided information on the genetic basis and mechanisms of MetS and metabolic components in Han Chinese.     

Serum copper levels and not zinc are positively associated with serum leptin concentrations in the healthy adult population

Leptin, the obesity gene protein product, is a hormone with multiple physiological functions in the human. However, there are few reports in the literature on its role in trace element metabolism in the normal population. Therefore, we investigated the association among serum leptin, zinc, copper, and zinc/copper ratio in 570 healthy men and women aged 15 yr and older. Serum leptin assay was done with a commercial enzymelinked immunosorbent assay kit; serum zinc and copper levels were measured by an atomic absorption spectrophotometer. Serum leptin was found to be positively associated with age (r=0.254, p<0.001), sex (r=0.406, p<0.001), body mass index (BMI) (r=0.553, p<0.001), and serum copper (r=0.419, p<0.001), but negatively associated with the zinc/copper ratio (r=−0.423, p<0.001). There was no significant association between serum leptin and zinc (r=−0.131, p>0.05). When the confounding effects of age, sex, and BMI were removed, serum leptin was still positively associated with serum copper (r=0.197, p=0.02) and the serum zinc/copper ratio (r=−0.182, p=0.03). These results suggest that copper and not zinc has an effect on serum leptin levels.     

Mapping the distribution of 3-hydroxylipins in the Mucorales using immunofluorescence microscopy

The distribution of endogenous 3-hydroxylipins (3-OH oxylipins) in representatives of the Mucorales was mapped using immunofluorescence microscopy. Strains of each of the following genera were examined: Absidia, Actinomucor, Cunninghamella, Mortierella (subgenus Micromucor), Mortierella (subgenus Mortierella), Mucor and Rhizomucor. Immunofluorescence microscopy was carried out using an antibody that was raised against 3R-hydroxy-5Z,8Z,11Z,14Z-eicosatetraenoic acid (3R-HETE), which cross-reacts with other 3-OH oxylipins. Subsequently, the occurrence and distribution of the antibody on the various reproductive stages of each fungus was noted. In Absidia, Actinomucor, Mortierella (subgenus Micromucor), Mucor and Rhizomucor, 3-OH oxylipins were found to be associated with the columellae and/or wall of the sporangium. In the representative of Cunninghamella, the 3-OH oxylipins were associated with the single-spored sporangiola. No 3-OH oxylipins were detected in the strains representing Mortierella (subgenus Mortierella).