bluuebunny/crossref_metadata_2025_split huggingface dataset:
Pollen and Resource Limitation in Veratrum nigrum L. (Liliaceae), an Andromonoecious Herb
Authors: Liao Wan‐Jin , Song Qing‐Fa , Zhang Da‐Yong 
Published: December 2006

AbstractPollen limitation and resource limitation were invoked to account for the pattern that flowering plants produce more flowers and ovules than fruits and seeds. This study aimed to determine their relative importance in Veratrum nigrum, a self‐compatible, perennial, andromonoecious herb. In order to determine whether female production was limited by pollen grains on stigmas or by available resources, we performed supplemental hand pollination in three populations, male‐flower‐bud removal in three other populations, and emasculation of hermaphroditic flowers in still another population, resulting in a total of seven populations experimentally manipulated. Across the three populations, supplemental hand pollination did not significantly increase fruit set, seed number per fruit, and total seed production per individual, nor did emasculation of hermaphroditic flowers. Taken together, our results suggest that pollen grains deposited on stigmas were abundant enough to fertilize all the ovules. Male‐flower‐bud removal significantly increased the mean size of hermaphroditic flowers in all three populations. Female reproductive success was increased in one population, but not in the other two populations possibly due to heavy flower/seed predation. We concluded that the female reproductive success of V. nigrum was not limited by pollen grains but by available resources, which is consistent with Bateman's principle. Furthermore, the female reproduction increase of male‐flower‐bud removal individuals might suggest a trade‐off between male and female sexual functions.(Managing editor: Wei Wang)
Complementation and Expression Analysis ofSoRab1AandSoRab2Ain Sugarcane Demonstrates Their Functional Diversification
Authors: Zhang Jia‐Ming , Sylvester Anne W , Li Ding‐Qin , Sun Xue‐Piao 
Published: December 2006

AbstractMammalian and plant Rab1 and Rab2 are small GTPases that regulate vesicle trafficking in the endoplasmic reticulum (ER) to Golgi compartments. Little is known about their functional diversification or potential interaction. We cloned sugarcane(Saccharum officinarumL.)Rab1AandRab2Agenes and studied their functional differences by expression and complementation experiments. We found differential expression of the two genes during sugarcane leaf development:SoRab2Aexpression declined from the dividing base to the maturing tip of the growing leaves, whereasSoRab1Awas constitutively expressed, suggesting that SoRab2A is required for cell division and expansion and SoRab1A is required for cells at all developmental stages. We used a yeast temperature sensitiveypt1‐A136Dmutant strain to further investigate these shared and unique functions. Ypt1 is a small GTPase that regulates vesicle transport in the same cellular location as Rab1 and Rab2. NeitherSoRab1AnorSoRab2Aalone could restore the growth of the mutant at restrictive temperatures whenSoRab1AandSoRab2Awere transformed separately. However,SoRab1Atransformants maintained normal morphology and viability at non‐permissive temperature, and resumed growth when returned to permissive temperature, whereasSoRab2Atransformants died at non‐permissive temperature, suggesting that SoRab1A function is required for a cell's viability. Mutant growth was fully restored whenSoRab1AandSoRab2Awere co‐transformed, indicating thatSoRab1AandSoRab2Acomplement each other and they both are needed to restore the function ofypt1‐A136D.These results demonstrate thatSoRab1AandSoRab2Aserve distinct but overlapping functions, mostly by regulating the transportation of different sets of proteins.(Managing editor: Li‐Hui Zhao)
Ecophysiological Response of Plants to Combined Pollution from Heavy‐duty Vehicles and Industrial Emissions in Higher Humidity
Authors: Cui Hong‐Xia , Jiang Gao‐Ming , Niu Shu‐Li , Jiang Chuang‐Dao , Liu Mei‐Zhen , Yu Shun‐Li , Gao Lei‐Ming 
Published: December 2006

AbstractPollution can be aggravated in industrial areas if traffic exhausts are mixed with industrial emissions under high humidity conditions. Plants growing in such environments may suffer from severe stress. The impact of vehicle emissions on urban vegetation in an industrial area in Qingdao, China, was investigated by studying seven plant species at visible, physiological and chemical levels. The traits of plant species in certain environmental conditions were compared between a clear area, Badaguan (BDG), and polluted area, Roadside (RS). We found that foliar sulfur uptake for all species was not significantly high at RS compared with BDG, although the sulfur content of atmosphere and surface soils at RS were much higher than those at BDG. For Ailanthus altissima Swingle, the content of foliar pigment and net photosynthesis rate (PN) decreased by 20%. Meanwhile, leaves became incrassate and no visible leaf damage was noted, suggesting this species could adapt well to pollution. A 50% decrease in PN occurred in Hibiscus syriacus L., but there was no statistical change in content of chlorophyll a and b and water uptake. Also, thickened leaves may prevent the pollutant from permeation. Foliar water content was still at a low level, although a water compensation mechanism was established for Fraxinus chinensis Rosb. reflected by low water potential and high water use efficiency. More adversely, a 65% decrease in PN happened inevitably with the significant decomposition of photosynthetic pigments, which exhibited visible damage. We also noted in one evergreen species (Magnolia grandiflora L.) that water absorption driven by low water potential should be helpful to supply water loss induced by strong stomatal transpiration and maintain normal growth. Furthermore, photosynthetic pigment content did not decline statistically, but supported a stable net assimilation. Two herbaceous species, Poa annua L. and Ophiopogon japonicus Ker‐Gawl., were very tolerant to adverse stress compared to other woody species, especially in assimilation through a compensatory increase in leaf area. A more remarkable decline in PN (decrease 80%) was noted in the exotic but widespread species, Platanus orientalis L., with serious etiolation and withering being exhibited on the whole canopy. Our results suggested, special for woody species, that most native species are more tolerant to pollution and therefore should to be broadly used in a humid urban industrial environment with heavy‐duty vehicle emissions.(Managing editor: Ya‐Qin Han)
Inhibition of
Plasmodium falciparum
Choline Kinase by Hexadecyltrimethylammonium Bromide: a Possible Antimalarial Mechanism
Authors: Choubey Vinay , Maity Pallab , Guha Mithu , Kumar Sanjay , Srivastava Kumkum , Puri Sunil Kumar , Bandyopadhyay Uday 
Published: December 2006

ABSTRACT

Choline kinase is the first enzyme in the Kennedy pathway (CDP-choline pathway) for the biosynthesis of the most essential phospholipid, phosphatidylcholine, in
Plasmodium falciparum
. In addition, choline kinase also plays a pivotal role in trapping essential polar head group choline inside the malaria parasite. Recently,
Plasmodium falciparum
choline kinase (PfCK) has been cloned, overexpressed, and purified. However, the function of this enzyme in parasite growth and survival has not been evaluated owing to the lack of a suitable inhibitor. Purified recombinant PfCK enabled us to identify an inhibitor of PfCK, hexadecyltrimethylammonium bromide (HDTAB), which has a very close structural resemblance to hexadecylphosphocholine (miltefosin), the well-known antiproliferative and antileishmanial drug. HDTAB inhibited PfCK in a dose-dependent manner and offered very potent antimalarial activity in vitro against
Plasmodium falciparum
. Moreover, HDTAB exhibited profound antimalarial activity in vivo against the rodent malaria parasite
Plasmodium yoelii
(N-67 strain). Interestingly, parasites at the trophozoite and schizont stages were found to be particularly sensitive to HDTAB. The stage-specific antimalarial effect of HDTAB correlated well with the expression pattern of PfCK in
P. falciparum
, which was observed by reverse transcription-PCR and immunofluorescence microscopy. Furthermore, the antimalarial activity of HDTAB paralleled the decrease in phosphatidylcholine content, which was found to correlate with the decreased phosphocholine generation. These results suggest that inhibition of choline kinase by HDTAB leads to decreased phosphocholine, which in turn causes a decrease in phosphatidylcholine biosynthesis, resulting in death of the parasite.
Emergence and Dissemination of
Enterobacteriaceae
Isolates Producing CTX-M-1-Like Enzymes in Spain Are Associated with IncFII (CTX-M-15) and Broad-Host-Range (CTX-M-1, -3, and -32) Plasmids
Authors: Novais Ângela , Cantón Rafael , Moreira Raquel , Peixe Luísa , Baquero Fernando , Coque Teresa M. 
Published: December 2006

ABSTRACT

The spread of CTX-M-1-like enzymes in Spain is associated with particular plasmids of broad-host-range IncN (
bla
CTX-M-32
,
bla
CTX-M-1
), IncL/M (
bla
CTX-M-1
), and IncA/C
2
(
bla
CTX-M-3
) or narrow-host-range IncFII (
bla
CTX-M-15
). The identical genetic surroundings of
bla
CTX-M-32
and
bla
CTX-M-1
and their locations on related 40-kb IncN plasmids indicate the in vivo evolution of this element.
Concentration-Dependent Effects of Caspofungin on the Metabolic Activity of
Aspergillus
Species
Authors: Antachopoulos Charalampos , Meletiadis Joseph , Sein Tin , Roilides Emmanuel , Walsh Thomas J. 
Published: December 2006

ABSTRACT

The minimum effective concentration (MEC) used to assess the in vitro antifungal activity of caspofungin against
Aspergillus
spp. is a qualitative endpoint requiring microscopic examination of hyphae. We therefore developed a tool for the quantitative assessment of caspofungin activity against
Aspergillus
spp. at clinically applicable concentrations. Susceptibility to caspofungin (0.008 to 8 μg/ml) was studied for 9
A. fumigatus
, 8
A. flavus
, and 12
A. terreus
isolates based on the Clinical and Laboratory Standards Institute M38-A protocol. After 48 h of incubation, the MEC was defined microscopically, and metabolic activity assessed with a modified XTT assay, using 100 μg of the tetrazolium salt XTT/ml and 6.25 μM menadione. A significant reduction in metabolic activity was demonstrated at the MEC (0.25 to 0.5 μg/ml) for all
Aspergillus
spp. and was more pronounced for
A. flavus
(median metabolic activity, 25% of control) compared to
A. fumigatus
and
A. terreus
(median metabolism, 42 and 53%, respectively), allowing determination of MEC with the XTT assay (93 to 100% agreement with microscopic MEC). Fungal metabolism tended to reach the lowest levels (median, 17 to 38% of control) one to two dilutions higher than the MEC, at the minimum metabolic activity concentration (MMC). For 5 of 9
A. fumigatus
isolates, 6 of 12
A. terreus
isolates, and 1 of 8
A. flavus
isolates, a paradoxical increase in metabolism was observed at concentrations greater than the MMC. Sigmoid (
E
max
) or bell-shaped models described accurately (median
R
2
= 0.97) the concentration-dependent metabolic changes in the absence or presence, respectively, of paradoxical response. Assessment of metabolic activity may provide useful quantitative endpoints for in vitro studies of caspofungin against
Aspergillus
spp.
Comparative Pharmacokinetics of Voriconazole Administered Orally as either Crushed or Whole Tablets
Authors: Dodds Ashley E. S. , Zaas A. K. , Fang A. F. , Damle B. , Perfect J. R. 
Published: December 2006

ABSTRACT
Voriconazole is a triazole antifungal agent used to treat serious, invasive fungal infections including aspergillosis and candidemia. Limitations with existing formulations of voriconazole including restricted utility in patients with renal dysfunction (intravenous preparation) and the unavailability of an oral suspension in some countries make the administration of crushed tablets desirable in many clinical scenarios. However, concerns that this approach may alter the systemic absorption of voriconazole exist. Therefore, an open-label, randomized, two-way crossover comparative pharmacokinetic (PK) study using healthy volunteers was performed to compare these methods of tablet administration. In a random sequence, subjects received voriconazole tablets either crushed or whole. The voriconazole dose was 400 mg every 12 h for 1 day orally followed by 200 mg every 12 h orally for 5.5 days. Study periods were separated by 7 days. PK parameters were determined by the noncompartmental method. An equivalence approach with no-effect boundaries of 80 to 125% was used to assess bioequivalence. Twenty healthy subjects (10 males; aged 20 to 43 years) were enrolled in and completed the study. The adjusted mean areas under the plasma concentration-time curve from 0 to τ, where τ equals 12 h, for the crushed and whole tablet groups were 9,793 and 11,164 ng · h/ml, respectively (ratio, 87.72; 90% confidence interval [CI], 80.97, 95.04). The ratio of the maximum concentration of drug in serum for the crushed tablet versus whole tablet arms was 94.94 (90% CI, 86.51, 104.22). The only difference noted between groups was a slightly faster time to maximum concentration of drug in serum when subjects received crushed tablets, 0.5 h versus 1.5 h (90% CI, −0.75, −0.25). Treatment-related adverse events occurred in 12 subjects receiving whole tablets and 9 subjects receiving crushed tablets; all were mild. The administration of crushed voriconazole tablets is bioequivalent to whole-tablet administration.
Deletion of the
Trypanosoma brucei
Superoxide Dismutase Gene
sodb1
Increases Sensitivity to Nifurtimox and Benznidazole
Authors: Prathalingham S. Radhika , Wilkinson Shane R. , Horn David , Kelly John M. 
Published: December 2006

ABSTRACT

It has been more than 25 years since it was first reported that nifurtimox and benznidazole promote superoxide production in trypanosomes. However, there has been no direct evidence of an association between the drug-induced free radicals and trypanocidal activity. Here, we identify a superoxide dismutase required to protect
Trypanosoma brucei
from drug-generated superoxide.
Aerobic Removal of Technetium by a Marine
Halomonas
Strain
Authors: Fujimoto Ken , Morita Takami 
Published: December 2006

ABSTRACT

A novel strain of
Halomonas
(Tc-202), which has the capability of removing Tc(VII) from solid- and aqueous-phase material aerobically, was isolated from the marine environment. Tc-202 removed 55% of the total
99
Tc in solutions at 15°C by reducing Tc(VII) to Tc(V), but other
Halomonas
strains did not.
Identification of a Putative Operon Involved in Fructooligosaccharide Utilization by
Lactobacillus paracasei
Authors: Goh Yong Jun , Zhang Chaomei , Benson Andrew K. , Schlegel Vicki , Lee Jong-Hwa , Hutkins Robert W. 
Published: December 2006

ABSTRACT

The growth and activity of some
Lactobacillus
and
Bifidobacterium
strains are stimulated by the presence of nondigestible fructooligosaccharides (FOS), which are selectively fermented by specific intestinal bacteria. Consumption of FOS, therefore, enriches for those bacteria that possess metabolic pathways necessary for FOS metabolism. In this study, a DNA microarray consisting of 7,680 random genomic library fragments of
Lactobacillus paracasei
1195 was used to examine genes involved in the utilization of FOS in this organism. Differential expression profiles between cells grown on FOS and those grown on glucose provided a basis for identifying genes specifically induced by FOS. Several of the FOS-induced genes shared sequence identity with genes encoding β-fructosidases and components of phosphoenolpyruvate-dependent phosphotransferase systems (PTS). These genes were organized in a putative operon, designated the
fos
operon, that may play an essential role in FOS utilization. The complete 7,631-bp nucleotide sequence of the putative
fos
operon was determined and consists of
fosABCDXE
genes, which encode a putative fructose/mannose PTS (FosABCDX) and a β-fructosidase precursor (FosE). The latter contains an N-terminal signal peptide sequence and cell wall sorting signals at the C-terminal region, suggesting its localization at the cell wall. Inactivation of the
fosE
gene led to impaired growth on FOS and other β-fructose-linked carbohydrates. Transcriptional analysis by reverse transcriptase PCR suggested that
fosABCDXE
was cotranscribed as a single mRNA during growth on FOS. Expression array analysis revealed that when glucose was added to FOS-grown cells, transcription of the FOS-induced genes was repressed, indicating that FOS metabolism is subject to catabolite regulation.
Diversity of Ammonia-Oxidizing Archaea and Bacteria in the Sediments of a Hypernutrified Subtropical Estuary: Bahía del Tóbari, Mexico
Authors: Beman J. Michael , Francis Christopher A. 
Published: December 2006

ABSTRACTNitrification within estuarine sediments plays an important role in the nitrogen cycle, both at the global scale and in individual estuaries. Although bacteria were once thought to be solely responsible for catalyzing the first and rate-limiting step of this process, several recent studies have suggested that mesophilicCrenarchaeotaare capable of performing ammonia oxidation. Here we examine the diversity (richness and community composition) of ammonia-oxidizing archaea (AOA) and bacteria (AOB) within sediments of Bahía del Tóbari, a hypernutrified estuary receiving substantial amounts of ammonium in agricultural runoff. Using PCR primers designed to specifically target the archaeal ammonia monooxygenase α-subunit (amoA) gene, we found AOA to be present at five sampling sites within this estuary and at two sampling time points (January and October 2004). In contrast, the bacterialamoAgene was PCR amplifiable from only 40% of samples. BacterialamoAlibraries were dominated by a few widely distributedNitrosomonas-like sequence types, whereas AOA diversity showed significant variation in both richness and community composition. AOA communities nevertheless exhibited consistent spatial structuring, with two distinct end member assemblages recovered from the interior and the mouths of the estuary and a mixed assemblage from an intermediate site. These findings represent the first detailed examination of archaealamoAdiversity in estuarine sediments and demonstrate that diverse communities ofCrenarchaeotacapable of ammonia oxidation are present within estuaries, where they may be actively involved in nitrification.
Quantification and Stability of Human Adenoviruses and Polyomavirus JCPyV in Wastewater Matrices
Authors: Bofill-Mas Silvia , Albinana-Gimenez Nestor , Clemente-Casares Pilar , Hundesa Ayalkibet , Rodriguez-Manzano Jesus , Allard Annika , Calvo Miquel , Girones Rosina 
Published: December 2006

ABSTRACT
Human adenoviruses (HAdV) and human polyomavirus JCPyV have been previously proposed as indicators of fecal viral contamination in the environment. Different wastewater matrices have been analyzed by applying real-time quantitative PCR procedures for the presence, quantity, and stability of a wide diversity of excreted HAdV and JCPyV. High quantities of HAdV and JCPyV were detected in sewage, effluent wastewater, sludge, and biosolid samples. Both viruses showed high stability in urban sewage. These results confirm the suitability of both viruses as indicators of human fecal viral pollution.
Culture Conditions Determine the Balance between Two Different Exopolysaccharides Produced by
Lactobacillus pentosus
LPS26
Authors: Sánchez Jorge-Ignacio , Martínez Beatriz , Guillén Rafael , Jiménez-Díaz Rufino , Rodríguez Ana 
Published: December 2006

ABSTRACT

Lactobacillus pentosus
LPS26, isolated from a natural fermentation of green olives, produces a capsular polymer constituted of two exopolysaccharides (EPS): EPS A, a high-molecular-weight (high-
M
w
) polysaccharide (1.9 × 10
6
Da) composed of glucose and rhamnose (3:1), and EPS B, a low-
M
w
polysaccharide (3.3 × 10
4
Da) composed of glucose and mannose (3:1). Fermentation experiments in a chemically semidefined medium with different carbon sources (glucose, fructose, mannitol, and lactose) showed that all of them except fructose supported EPS A production rather than EPS B production. The influence of temperature and pH was further analyzed. As the temperature dropped, increased synthesis of both EPS was detected. The control of pH especially enhanced EPS B production. With regard to this, the maximum total EPS production (514 mg liter
−1
) was achieved at a suboptimal growth temperature (20°C) and pH 6.0. Continuous cultures showed that EPS A, synthesized mainly at low dilution rates, is clearly dependent on the growth rate, whereas EPS B synthesis was hardly affected. EPS production was also detected in supplemented skimmed milk, but no increase on the viscosity of the fermented milk was recorded. This could be linked to the high proportion of the low-
M
w
polysaccharide produced in these conditions in contrast to that observed in culture media. Overall, the present study shows that culture conditions have a clear impact on the type and concentration of EPS produced by strain LPS26, and consequently, these conditions should be carefully selected for optimization and application studies. Finally, it should be noted that this is, to our knowledge, the first report on EPS production by
L. pentosus
.
Identification of Human and Animal Adenoviruses and Polyomaviruses for Determination of Sources of Fecal Contamination in the Environment
Authors: Hundesa Ayalkibet , Maluquer de Motes Carlos , Bofill-Mas Silvia , Albinana-Gimenez Nestor , Girones Rosina 
Published: December 2006

ABSTRACT

The
Adenoviridae
and
Polyomaviridae
families comprise a wide diversity of viruses which may be excreted for long periods in feces or urine. In this study, a preliminary analysis of the prevalence in the environment and the potential usefulness as source-tracking tools of human and animal adenoviruses and polyomaviruses has been developed. Molecular assays based on PCR specifically targeting human adenoviruses (HAdV), porcine adenoviruses (PAdV), bovine adenoviruses (BAdV), and bovine polyomaviruses (BPyV) were applied to environmental samples including urban sewage, slaughterhouse, and river water samples. PAdV and BPyV were detected in a very high percentage of samples potentially affected by either porcine or bovine fecal contamination, respectively. However, BAdV were detected in only one sample, showing a lower prevalence than BPyV in the wastewater samples analyzed. The 22 slaughterhouse samples with fecal contamination of animal origin showed negative results for the presence of HAdV. The river water samples analyzed were positive for the presence of both human and animal adenoviruses and polyomaviruses, indicating the existence of diverse sources of contamination. The identities of the viruses detected were confirmed by analyses of the amplified sequences. All BPyV isolates showed a 97% similarity in nucleotide sequences. This is the first time that PAdV5, BAdV6, and BPyV have been reported to occur in environmental samples. Human and porcine adenoviruses and human and bovine polyomaviruses are proposed as tools for evaluating the presence of viral contamination and for tracking the origin of fecal/urine contamination in environmental samples.