(c) 2008 Elsevier Ireland Ltd. All rights reserved.”
“Understanding the folding of centromere DNA in the maximally condensed methaphase chromosome remains a basic challenge in cell biology. We propose here a set of structural models with a graphical presentation of alphoid higher order repeat (HOR)

distribution in the centromere folding, based on the assumption of encryption key for microtubule-centromere interaction which arises from chromosomespecific crystal-like structure of HORs. Specific HOR leads to a characteristic geometrical pattern which may be responsible for individual microtubule to recognize a specific structure of centromere in each chromosome. (c) 2008 Elsevier BTSA1 Ltd. All rights reserved.”
“Recently it has been shown that fructose-1,6-diphosphate see more (FDP) has dose-dependent anticonvulsant

activity in rat models of acute generalized motor seizures induced with chemical convulsants. The present study asked whether FDP also has activity in an epileptic brain after oral administration and activity against non-convulsive seizures. Animals (n = 14) were administered pilocarpine to induce status epilepticus. Several weeks later, these animals had spontaneous seizures and a baseline rate of seizure frequency was determined over a 6-day period. Animals were then continued without treatment (n = 8) or 0.5% FDP was added to the drinking water (n = 6). In animals treated with FDP the seizures completely stopped after 7 days. Removal of FDP from the water resulted in the return of seizure activity in 4 of the 6 animals by 16 days of observation. To induce non-convulsive seizures, animals (n = 6) received a single injection of gamma-butyrolactone (GBL, 100 mg/kg i.p.). All animals had spike-wave activity recorded in the cortex within minutes after GBL administration. Administration of a single injection of FDP (500 g/kg i.p.) had no effect on the baseline cortical activity, nor on the spike-wave activity induced by

GBL (n = 5). These experiments suggest that oral administration of FDP may have utility in the treatment of partial or generalized convulsive seizure disorders, but not absence seizures. (c) 2008 Elsevier Ireland Ltd. All rights reserved.”
“We 3-mercaptopyruvate sulfurtransferase analyse a model of mate choice when males differ in reproductive quality and provide care for their offspring. Females choose males on the basis of the success they will obtain from breeding with them and a male chooses his care time on the basis of his quality so as to maximise his long-term rate of reproductive success. We use this model to establish whether high-quality males should devote a longer period of care to their broods than low-quality males and whether females obtain greater reproductive Success from mating with higher quality males. We give sufficient conditions for optimal care times to decrease with increasing male quality.

The results reported from Gerard ARRY-162 datasheet et al. [18] indicated that during the primary phase of active infection, C. trachomatis obtains the energy essential for EB to RB transformation, and also for metabolism, from host cells via ATP/ADP exchange. Through active growth of the RB, the organisms acquire ATP not only from the host, but also via their own glycolytic and pentose phosphate pathways. Gerard et al. (2002) showed that throughout the initial phase of monocyte infection, prior to the complete establishment of persistence, C. trachomatis cells utilized both ATP/ADP exchange and their own pathways to support metabolic

needs, even though the overall metabolic rate in the organisms was relatively low. However, when persistence has been established, the only source of ATP seemed to be the host [18]. That is, mRNA for glycolytic and pentose phosphate pathway enzymes were absent or severely reduced, suggesting that these systems were partially, if not completely, shut down during persistence. Therefore, C. trachomatis seems to be only partial energy parasites on their hosts during active growth, however during persistent infection, the organisms appear to be completely dependent on the host for ATP. Most notably in our current project, pyk and yggV were strongly down-regulated (3-fold and 10-fold respectively) Evofosfamide price following supplementation with estradiol, which

may selleck chemicals contribute to a reduction in the rate of glycolysis biosynthesis during persistence. Two other well known chlamydial persistence genes (cydA, cydB), which play a part in the electron transport system were also down-regulated (8-fold and 4-fold respectively) in the presence of estradiol. The

other key persistence-suggestive change was observed at the morphological level. It has been previously reported by several authors [13, 23, 24] that chlamydiae show abnormal morphology under persistence conditions. We analysed both un-exposed as well as hormone-exposed C. trachomatis infected ECC-1 cell cultures using Transmission Arachidonate 15-lipoxygenase Electron Microscope (TEM) analysis (Figure 1). Under normal cell culture conditions (ie cell culture media supplemented with FCS) we observed normal chlamydial inclusion growth and development as depicted by a mixture of characteristic RBs and EBs of normal size and shape (Figure 1, Panel A). By comparison, when we grew the chlamydiae in charcoal stripped foetal calf serum (hormone free media), supplemented with estradiol, we observed typical chlamydial persistence inclusions containing aberrant, enlarged RBs which had not differentiated into EBs (Figure 1, Panel C). The morphological features that we observed associated with hormone-mediated persistence demonstrate similarities to those observed by others for persistence induced by IFN-γ and penicillin. Figure 1 Transmission electron micrographs of C.

It

can be seen that two series of films are only composed of TiN or TiAlN phase, while www.selleckchem.com/products/ferrostatin-1-fer-1.html no SiN x phase is detected. Veprek had attributed the absence of SiN x phase to its amorphous characteristic [4]. Actually, it can also be explained by low content of SiN x phase. Figure 1a,b indicates that TiN/SiN x and TiAlN/SiN x nanocomposite films both present (200) preferred orientation. With the increase of Si content, the intensities of TiN and TiAlN (200) diffraction peaks firstly increase and then decrease, suggesting that the crystallinity for TiN and TiAlN phases initially improves and then deteriorates. The TiN/SiN x and TiAlN/SiN x films exhibit the highest crystallinity when Si/Ti (or Si/Ti0.7Al0.3) ratio is 4:21 and 3:22, respectively. Figure 1 XRD patterns of (a) TiN/SiN x and (b) TiAlN/SiN x nanocomposite films with different Si content. The influence of Si content on crystallinity throws doubt upon the nc-TiN/a-SiN x model proposed by Veprek [3, 4]. If SiN x phase exists as amorphous state, the increase of Si/Ti ratio from 1:24 to 5:20 (SiN x fraction

accordingly rises from 4 to 20 at.%) only leads to thickening of amorphous SiN x interface, which cannot Selleck Blasticidin S improve the crystallization degree of film, but lowers it due to the increasing impeditive effect selleck compound on TiN growth. In addition, as amorphous SiN x interfacial phase thickens, TiN and TiAlN phases cannot only present (200) orientation, but may also grow along other directions owing to the randomicity of triclocarban crystallite growth [10]. Therefore, whether SiN x interfacial phase

is amorphous deserves to be further deliberated. In fact, the effect of Si content on crystallinity of TiN/SiN x and TiAlN/SiN x films brings into our mind the influence of amorphous modulation layer thickness on the crystallization degree of nanomultilayered films, such as TiN/SiC [11], TiAlN/SiO2[12], and CrAlN/SiN x [13]. In these nanomultilayered film systems, with the increase of amorphous layer thickness, the crystallization degree of films firstly increases and then decreases, which can be attributed to two facts. On one hand, the initial increase of amorphous layer thickness could not only crystallize the amorphous layer and grew epitaxially with crystal layer, but also the newly deposited crystal layer could grow epitaxially on crystallized amorphous layer, leading to the ‘mutual promotion effect’ of growth in nanomultilayers and improvement of crystallization integrity. The thicker the crystallized amorphous layer thickness is, the higher the crystallization degree of the nanomultilayered film. On the other hand, with further increase of amorphous layer thickness, the amorphous layers cannot keep the crystallization state and change back into the amorphous state, which destructs epitaxial growth structure and decreases the crystallization integrity of the nanomultilayer.

The three most abundant bacterial classes in the tomato fruit surface environments compared in this study were Gamma, Alpha and Betaproteobacteria. These were also found in higher abundance in the phyllosphere

of other plant species, although the relative abundances for these classes vary [16–18, 27]. Genera here found in high abundance in the tomato fruit surface, such as Pantoea and Enterobacter, are buy MM-102 also abundant in the phyllosphere of certain Atlantic Pictilisib molecular weight rainforest tree species and cottonwood, indicating a wide distribution across different plant species [16, 18]. Bacterial genera found in our 2009 fruit surface samples were also identified among the culturable bacteria on leaves of field-grown tomatoes, including Pseudomonas, Pantoea, Sphingomonas, Massilia, Xhantomonas and Curtobacterium [32]. Two additional genera, Burkholderia and Leuconostoc, showed high abundance in our study. Burkholderia was the most abundant genus in our groundwater samples, representing 75% of the sequences, and might have been introduced in the environment through groundwater applications. Leuconostoc has been previously described as the predominant lactic acid bacteria on tomato fruit buy LY2874455 surfaces [33]. Similar bacterial classes and genera were found in high abundance in samples collected in 2008 and 2009, with the largest differences corresponding

to the unclassified sequences. Several different reasons could account for this variation, including differences in DNA extraction, sequencing sample preparation and primers used in both years, as well as potential growing season effects. Of special interest is the high proportion of sequences identified Tideglusib as Enterobacteriaceae, given that this family includes important human pathogenic bacteria like Salmonella and E. coli. Similar representation of this family was obtained in the phyllosphere of Trichilia spp. and Pinus ponderosa, but not in that of Campomanesia xanthocarpa [16, 27]. The high adaptability of this family to

the tomato fruit surface environment might be associated to the higher risk of disease outbreaks associated with this crop. Differences between fruit surface environments do not appear to be linked to the water applications, indicating that plant conditions allow for only some of the bacterial groups present in water to establish themselves. Similar results were obtained when the fruit surface communities living on apple trees under conventional and organic management were compared, where only low abundance groups differed between the two environments [17]. Similarly, no effect on the levels of fecal and total coliforms was observed when reclaimed water with higher coliform counts, and well water were sprayed on six horticultural crops [14].

Blood glucose and insulin levels were determined with glucose challenge (2g/kg glucose infusion) and without (basal). A randomized, double-blind, cross-over clinical trial in 12 Entospletinib solubility dmso non-diabetic men was performed to approve the effect of RT on serum glucose and insulin levels, as well as cardiovascular parameters. Subjects reported to the lab on 2 different mornings separated by 1 to 2 weeks, and ingested 75 g of dextrose in solution. 15 min before ingestion, men

ingested either 2 g of RT or placebo. Blood samples were collected before ingestion of the RT and placebo, and several time points after dextrose administration. Results It was shown that the aqueous extract of RT lowered the blood glucose level in both animals and humans (albeit non-statistically). The area under the blood glucose curve (AUC) was significantly decreased after oral administration of aqueous RTE to non-fasted Wistar rats (19,000 rel. AUC vs. 30,000 rel. AUC, n=8, APR-246 mw p<0.001). For serum glucose, no condition (p=0.19) or condition x time

(p=0.99) effect was noted in the clinical trial. Similar findings were noted for insulin. However, a time effect was noted (p<0.0001), with values at the 15 and 30 min blood collection times higher than pre-ingestion. Additionally, a potential positive impact of RTE administration on certain cardiovascular parameters was noted. Conclusion The aqueous extract of RT is a promising and safe (lack of potentially harmful estragole and methyleugenol) ingredient for consideration in the development of functional foods or dietary and sports supplements with anti-hyperglycemic

activity. In this context, a study investigating the potential of RT to increase serum insulin concentration while reducing blood glucose level for a given amount of glucose ingestion after an endurance exercise bout is ongoing. Thus, RT might also act as a “recovery agent”.”
“Background ISSN recommendations for individuals Alpelisib manufacturer involved in a general fitness program are to ingest 25-35 kcal/kg/day consisting of 3-5 g/kg of carbohydrate and ≤30% of total calories from fat. Additionally, the ISSN recommends that individuals engaged in resistance-training should ingest 1.4-2.0 g/kg/d of protein and to ingest some protein after exercise. This study examined whether nutritional counseling and post-workout supplementation affects dietary intake during training. Methods Eleven trained men (25±5 yrs, why 180±6 cm, 82±12 kg, 14±3 %fat, training 7±4 years, 3±2 days/wk) were provided nutritional counseling by a dietitian prior to participating in a supervised resistance-training program (4 days/wk). A supplement containing 40g carbohydrate, 20g protein, and 3.5g fat was provided post-exercise. Diet records were obtained at 0, 3, 7, & 11 weeks while DEXA determined body composition, 1RM bench press, and 1RM squat measurements were obtained at 0, 4, 8, & 12 wks. Data were analyzed by ANOVA with repeated measures and are presented as means ± standard deviations.

The remainder of the paper is arranged as follows. The next

section briefly explains the construction of MD simulation www.selleckchem.com/products/Cyt387.html models and introduces the indentation process parameters for the simulation cases. Thereafter, the simulation results under dry indentation and wet indentation are compiled. They include the comparisons of load–displacement curves, calculated hardness and Young’s modulus values, the distributions of friction and normal forces along the indenter/work interface, and stress distribution within the work material. Finally, conclusions are drawn in the final section. Methods Three-dimensional (3D) MD simulation models are constructed to study the indentation processes on single-crystal copper by a half-cylinder diamond indenter. Go6983 cost For wet indentation, water molecules are added to fill the gap between the indenter and the work material in the system. For dry indentation, no water molecules are added. We employ LAMMPS, an open-source software developed by Sandia

National Laboratory [21], to carry out the simulation computation. Figure 1 shows the schematic of MD simulation models for Fedratinib cell line dry and wet indentations. The dimension of the copper work material is 247 × 216 × 70 Å3 (X, Y, and Z directions, respectively) for all simulation cases, and it consists of 306,000 copper atoms. The copper indentation surface is a (1 1 1) plane. The indenter has a radius of 50 Å, consisting of 46,000 carbon atoms. At the initial stage, the offset distance between the indenter and the work material is 5 Å. For wet indentation cases, the entire indenter is submerged in water, so both the

indenter and the work material are in contact with water. In this case, 90,324 water atoms are contained in the system, including 60,216 hydrogen atoms and 30,108 oxygen atoms. Meanwhile, two special layers are defined in the copper work material, namely a thermal layer and a fixed layer. The fixed layer is located at the bottom of the work material, and it acts as a base to avoid Monoiodotyrosine any movement of the work material. The thermal layer is located right above the fixed layer, and it acts as a heat sink to maintain the temperature of the simulation system. In addition, since the simulation size is extremely small, a periodic boundary condition is applied along the Z direction so that the simulation box is replicated throughout the space to form an infinite lattice. This can effectively mitigate a spurious size effect when investigating the behavior of an isolated system. Figure 1 Schematic of MD simulation models for (a) dry nano-indentation and (b) wet nano-indentation. In this study, we compare wet nano-indentation with dry nano-indentation by focusing on the tool/material interaction and process performances. Meanwhile, we consider the potential effect of indentation speed by including three levels of indentation speed. As a result, six simulation cases are created. Table 1 presents the detailed parameters of the six cases.

Appl Surf Sci 2008, 254:5403–5407.CrossRef 22. Cho S, Ma J, Kim Y, Sun Y, Wong GKL, Ketterson JB: Photoluminescence and ultraviolet lasing of polycrystalline ZnO thin films prepared by the oxidation of the metallic Zn. Appl Phys Lett 1999, 75:2761–2763.CrossRef 23. Alves E, Rita E, Wahl U, Correia JG, Monteiro T, Soares J, Boemare C: Lattice site location and optical activity of Er implanted #AZD5363 nmr randurls[1|1|,|CHEM1|]# ZnO. Nucl Instrum Meth B 2003, 206:1047–1051.CrossRef 24. Auret FD, Goodman SA, Hayes M, Legodi MJ, Van Laarhoven HA, Look DC: Electrical characterization of 1.8 MeV proton-bombarded ZnO. Appl Phys Lett 2001, 79:3074–3076.CrossRef 25. Lorenz K, Alves E, Wendler E, Bilani O, Wesch

W, Hayes M: Damage formation and annealing at low temperatures in ion implanted ZnO. Appl Phys Lett 2005, 87:191904.CrossRef 26. Krishna GSK458 mouse R, Baranwal V, Katharria YS, Kabiraj D, Tripathi A, Singh F, Khan SA, Pandey AC, Kanjilal D: Nanostructure formation on zinc oxide

film by ion bombardment. Nucl Instrum Meth B 2006, 244:78–80.CrossRef 27. Liao L, Zhang Z, Yang Y, Yan B, Cao HT, Chen LL, Li GP, Wu T, Shen ZX, Tay BK, Yu T, Sun XW: Tunable transport properties of n-type ZnO nanowires by Ti plasma immersion ion implantation. J Appl Phys 2008, 104:076104.CrossRef 28. Panigrahy B, Aslam M, Bahadur D: Controlled optical and magnetic properties of ZnO nanorods by Ar ion irradiation. Appl Phys Lett 2011, 98:183109.CrossRef 29. Chang L-W, Sung Y-C, Yeh J-W, Shih HC: Enhanced optoelectronic performance from the Ti-doped ZnO nanowires. J Appl Phys 2011, 109:074318.CrossRef 30. Wang DF, Lu HB, Li JC, Wu Y, Tian Y, Lee YP: Effects of low-energy hydrogen

ion implantation on optical properties of ZnO nanowires. Mater Res Bull 2009, 44:41–44.CrossRef 31. Sadek AZ, Wlodarski W, Li YX, Yu W, Li X, Yu X, Kalantar-zadeh K: A ZnO nanorod based layered ZnO/64° YX LiNbO 3 SAW hydrogen gas sensor. Thin Solid Films 2007, 515:8705–8708.CrossRef 32. Sadek AZ, Wlodarski W, Shin Protirelin K, Kaner RB, Kalantar-zadeh K: A polyaniline/WO 3 nanofiber composite-based ZnO/64° YX LiNbO3 SAW hydrogen gas sensor. Synth Met 2008, 158:29–32.CrossRef 33. Chen Y, Bagnall DM, Koh H-j, Park K-t, Hiraga K, Zhu Z, Yao T: Plasma assisted molecular beam epitaxy of ZnO on c -plane sapphire: growth and characterization. J Appl Phys 1998, 84:3912–3918.CrossRef 34. Vlasenko LS, Watkins GD: Optical detection of electron paramagnetic resonance in room-temperature electron-irradiated ZnO. Phys Rev B 2005, 71:125210.CrossRef 35. Vanheusden K, Seager CH, Warren WL, Tallant DR, Voigt JA: Correlation between photoluminescence and oxygen vacancies in ZnO phosphors. Appl Phys Lett 1996, 68:403–405.CrossRef 36. Wu XL, Siu GG, Fu CL, Ong HC: Photoluminescence and cathodoluminescence studies of stoichiometric and oxygen-deficient ZnO films. Appl Phys Lett 2001, 78:2285–2287.CrossRef 37.

In both, the recognition of pathogen-associated molecular patterns (PAMPs) by Toll receptors (insects) and Toll-like receptors (mammals) results in the production of antimicrobial peptides [23]. Furthermore, insect hemocytes and mammalian neutrophils can both engulf and kill most invading microorganisms [24]. Insects are also afforded protection from microorganisms through the coagulation and melanization of hemolymph, but they do not have an adaptive

immune system. In addition to biological similarities, several logistical issues contribute to the recent adoption of insects as alternative hosts for bacterial pathogens. Insects can be readily obtained, housed, and cared for at considerable cost savings compared to mammals. Moreover, the use of insects is not governed by animal use regulations or committees find more and even very large-scale experiments using insects are considered ethically acceptable. As a possible insect alternative to mammalian models of infection, we tested several B. pseudomallei, B. mallei, and B. thailandensis strains against juvenile Madagascar hissing cockroaches (MH cockroaches) obtained from a commercial vendor (Carolina Biological Supply Company). MH cockroaches are readily available, easily cultured, and reproduce rapidly. They are larger than wax moth larvae, slow moving compared to other species of cockroaches, and have a substantive carapace. These characteristics make them easier to manipulate

and inoculate with known numbers of bacteria compared with other species of insects commonly used for similar Buspirone HCl studies. MH cockroaches thrive at Selleck GDC 941 37°C, a characteristic that is essential for the analysis of mammalian pathogens. In this study, we found the MH cockroach to be a suitable surrogate host for B. pseudomallei, B. mallei, and B. thailandensis. Burkholderia type VI secretion https://www.selleckchem.com/products/i-bet-762.html system mutants were attenuated in MH cockroaches, which is consistent with what is seen in rodent models of infection [9, 25]. B. pseudomallei multiplied inside MH cockroach hemocytes and may be the primary mechanism by which this pathogen avoids elimination by the MH cockroach innate immune system. The results suggest that MH cockroaches are a good

alternative to mammals for the study of Burkholderia species and possibly other mammalian pathogens. Results and discussion B. pseudomallei is virulent in the MH cockroach and T6SS-1 mutants exhibit attenuated virulence In an attempt to determine if the MH cockroach might serve as a surrogate host for B. pseudomallei, we challenged juvenile MH cockroaches (Figure 1) with K96243 and T6SS mutant derivatives. T6SS-1 is a critical virulence determinant for B. pseudomallei in the hamster model of infection [9], while T6SS-2, T6SS-3, T6SS-4, T6SS-5, and T6SS-6 are dispensable for virulence in hamsters. Groups of eight MH cockroaches were challenged by the intra-abdominal route with 101-105 bacteria and deaths were recorded for 5 days at 37°C (Figure 2).

Methods Patients Blood samples were obtained from 92 patients (50 men and 42 women, mean age 48.7 GSI-IX clinical trial ± 11.13) with squamous carcinoma of head and neck. Control samples consisted of age matched 124 cancer-free blood donors (63 men and 61 women, mean age 44.47 ± 19.24). Despite of 4 years younger controls then patients, there were not statistical differences in age of analyzed groups (P = 0.169). Prior to examination, the patients and control

subjects, did not receive medicaments like antibiotics or steroids. Patients enrolled to the examination were analyzed according to cancer staging system of the TNM Classification of Malignant Tumours that describes the extent of cancer in a patient’s body: T describes the size of the tumor and whether it has invaded Anti-infection inhibitor nearby tissue, N describes regional lymph nodes that are involved and M describes distant metastasis (spread of cancer from one body part to another). Within the control group selected subjects (52 cases) were classified as smokers for at least 10 years, up to 10 cigarettes per day. The selleck smoking attitude of head and neck cancer group was also analyzed for non-smoking patients, patients smoking 10 cigarettes per day for ten years, patients smoking 20 cigarettes per day for twenty years and patients smoking 20 cigarettes

per day for thirty years. All patients and controls subjects were recruited from three medical units of Head and Neck Neoplasm Surgery Departments, Medical University of Lodz, Poland. All subjects included into the study were unrelated Caucasians and inhibited Lodz district, Poland. The study was approved by the Local Ethic Committee and written consent was obtained from each patient or healthy blood out donor before enrolling into the study. Genotype determination Genomic DNA was isolated from blood cells

using Phenol-Chloroform extraction method. Genotypic analysis of the XRCC1 399 G > A polymorphism was determined by the PCR-based restriction fragment length polymorphism (PCR-RFLP) method, as described in detail earlier [28]. Briefly, PCR primers for the XRCC1 codon 194 (forward 5′-GCCCCGTCCCAGGTA-3′ and reverse 5′-AGCCCCAAGACCCTTTCATC-3′) were used to generate a 292 bp product containing the polymorphic sites. PCR primers for the XRCC1 codon 399 (forward 5′-TTGTGCTTTCTCTGTGTCCA-3′ and reverse 5′-TCCTCCAGCCTTTTCTGATA-3′) were used to generate a 615 bp product containing the polymorphic sites. The PCR was carried out in a MJ Research, INC thermal cycler, model PTC-100 (Waltham, MA, USA). The PCR reactions were carried out in a 20 μl volume of 20 pmol of each primer, 0.

Among them, Acinetobacter, Agrobacterium, Bacillus, and Pseudomonas species were commonly found at other arsenic-contaminated sites [16, 29, 30, 32–35]. To our knowledge, Janibacter, Micrococcus, Thauera, and Williamsia were novel arsenite-resistant

bacteria isolated in this study. We found that the high Vactosertib nmr arsenic TS site revealed a much higher diversity of arsenite-resistant bacteria and the resistance levels observed were also much higher than in isolates found in the intermediate and low arsenic-contaminated this website sites. It is a limitation that only one medium (CDM) was used for bacterial isolation which could result in the observed differences between sites. The 12 strains with arsenite MICs > 20 mM were all obtained from the high arsenic soil. Generally, it has been proposed that high arsenic contamination is likely to exert a strong selective pressure leading to low microbial diversity [16, 32]. However, the TS site used in our study had several hundred years of smelting history [36] which may result in the evolution of more bacterial species that were already well adapted at elevated arsenic concentrations. Moreover, Pennanen et al. [37] reported that

at long-term field sites, soil microbial communities have had time to adapt to metal and/or metalloid stress. Selleck BX-795 Turpeinen et al. [33] also found that the diversity of arsenic-resistant bacteria in higher arsenic-, chromium- and copper-contaminated soil was higher than that in less contaminated soil. These results suggested that microorganisms had been adapted to high arsenic stress and maintained their diversity in TS site after a long-term exposure to arsenic. The aoxB genes were detected in all of the five arsenite oxidizers but not in the non-arsenite oxidizers. This indicates that aoxB may be specific for most of the aerobic arsenite-oxidizing bacteria and useful for detecting arsenite-oxidizing microorganisms in the environment. Inskeep et al. [15] reported that arsenite oxidase

genes are widely present in different arsenite oxidizers and widespread in soil-water systems. We have enriched pristine soils with arsenite to isolate arsenite-oxidizing bacteria from non-contaminated 5-Fluoracil cell line soils but without success. To our knowledge, all of the cultured arsenite oxidizers obtained so far were isolated from arsenic-contaminated sites. Inskeep et al. [15] detected aoxB-like sequences from arsenic-contaminated environments but not from pristine soils indicating that arsenite oxidation is a major process in arsenic-contaminated environments. The expression level of aoxB could probably be applied to monitor environmental arsenic-contaminated levels. A phylogenetic analysis of the 5 arsenite oxidizers based on the 16S rRNA genes and the aoxB genes showed a similar phylogeny indicating genomic stability of the aoxB genes.