001, for travel >6 weeks) The prevalence of TD was also highly a

001, for travel >6 weeks). The prevalence of TD was also highly associated with duration of travel: 19.6% of short-term (2 weeks or less) travelers developed diarrhea, versus 29.8% of longer-term (greater than 2 weeks) travelers (p = 0.024). We found no difference in the

overall rates of illness for vaccinated travelers versus nonvaccinated travelers, although 91% of travelers received pre-travel vaccination. GSK1120212 clinical trial The study was not powered or designed to assess vaccine efficacy in the prevention of overall illness. The travel cohort was divided into quartiles based on the interval from their travel visit until their departure (1–2, 2–4, 4–6, and >6 weeks). There was no statistical difference noted between the quartiles regarding the lead time from clinic visit to departure and

the relative rates of illness. Qualitative response data, such as the usefulness of Ibrutinib the pre-travel visit and counseling was also evaluated. Respondents were asked to rate the quality of pre-travel advice given to them on a 4-point scale from “none of it helpful” (=1) to “all of it helpful” (=4); of the responders, 92.2% found “most” or “all” of the travel advice to be helpful. Results of our retrospective survey analysis reveal that high rates of self-reported illness in returning travelers remain a significant issue. The overall rate of illness in travelers with developing countries as destinations averaged 20% among our convenience cohort, regardless of the continent visited. A comprehensive review by Steffen[5] of prior studies reported a historic rate of up to 77% for general illness occurring in travelers to developing countries. Although illness

rates in our study were lower than in the Steffen review, and lower than in several other cohort studies,[6-9] they still are relatively high considering that all of these individuals sought pre-travel counseling. In contrast to previously published survey studies, we did not find statistically different illness rates among our travelers going Glutathione peroxidase to Asia, Africa, Central America, and South America.[6, 7] The most striking finding was a strong association between the duration of travel and the incidence of general illness and severe illness as defined above. Long-term travelers (in our study we defined long term as greater than 4 weeks) had more than twice the rates of illness and TD than did our short-term travelers (Figure 2). These illness rates are comparable to an earlier travel survey study of Swedish travelers, which showed a significant correlation (OR = 3.2) between illness and travel duration of greater than 4 weeks.[9] Similarly, a study by Winer and Alkan also noted a significant effect of trip duration on likelihood of illness, although the mean duration of travel in their population was much longer at 14.7 weeks.

We used data from the HIV Research Network

(HIVRN), a con

We used data from the HIV Research Network

(HIVRN), a consortium of sites (see Appendix) that provide primary and subspecialty care to HIV-infected patients in 14 cities throughout the USA. To participate in the HIVRN, a site had to have a minimum data set including the patients’ age, sex, race, HIV transmission risk factor, AIDS-defining illnesses, CD4 Selleck CHIR 99021 cell count, HIV-1 RNA level and use of antiretroviral medication. Eleven HIVRN sites that treated adult HIV-infected patients, nine with academic affiliations, also collected data on resource utilization and in-patient ICD-9 codes. Data from 10 of these sites, located in the Northeastern (six sites), Western (two), Midwestern (one) and Southern (one) USA, were included in the analysis. One nonacademic site discontinued participation in the HIVRN during this period and was excluded from analyses. All adult HIV-infected patients (≥18 years old) at these 10 sites with at least one out-patient visit between 2000 and 2008 were eligible for inclusion in the study. Each site abstracted the data elements described above from electronic or paper

records. After removal of identifying information, the sites sent the abstracted data Selleckchem Alectinib to a data co-ordinating centre in an electronic format. For this analysis, data collection encompassed the period from 1 January 2000 to 31 December 2008, as recorded by the date of encounter, not the date of billing or claim payment. Development, maintenance and use

of the database are approved by the Institutional Review Board of the Johns Hopkins University School of Medicine, which serves as the data co-ordinating centre, as well as the Institutional Review Boards of each of the participating institutions. Because bacteraemia is nearly always treated in in-patient settings, we focused on hospital admissions data recorded at each study site. Each click here HIVRN site reported dates of admission and discharge and all ICD-9 codes associated with an in-patient episode. Any text descriptions were translated to ICD-9 codes. All in-patient episodes were reviewed, starting from 1 January 2000 or the patient’s first recorded out-patient visit to the HIV clinic, whichever came later, and ending at date of death or 31 December 2008, whichever came first. ICD-9 codes were examined to identify all in-patient cases of bacteraemia or septicaemia during the study period. The ICD-9 code for septicaemia (038.XX) intrinsically includes the organism of interest whereas the ICD-9 code for bacteraemia (790.7) does not include an organism. Therefore, in these cases we used the second ICD-9 code (041.XX), which indicates the organism causing bacteraemia. Table 1 shows the classification of bacteraemia/septicaemia episodes in terms of types of organisms and their mapping to ICD-9 codes. In addition, analyses also included a small number of episodes associated with Salmonella (003.1) and Listeriosis (027.0).

Jiang and J-Y Kim, unpublished data) Past studies have used AA

Jiang and J.-Y. Kim, unpublished data). Past studies have used AAV-GFP virus for in vivo imaging following stereotaxic injection into mice and monkeys (Stettler et al., 2006; Lowery et al., 2009). Local injection has the benefit of eliminating background fluorescence from distant projection neurons, but at the cost of having less control over the density of labeled cells due to a sharp gradient in transduction from the site of injection. Neonatal transduction provides improved

consistency Selleckchem Epacadostat in the expression pattern, and offers a serviceable alternative to Thy1-XFP lines (Feng et al., 2000), particularly when working with models that already require multiple transgenes or modified alleles. Viral transgenesis also Selleckchem Proteasome inhibitor provides access to neurons not labeled in the Thy1-XFP mice, notably Purkinje cells of the cerebellum, which in the past have required acute injection of synthetic dyes for morphological study in vivo (Gobel & Helmchen, 2007). Given the high plasticity of cerebellar circuitry and the progressive but poorly understood degeneration

of Purkinje neurons in many inherited ataxias (Boyden et al., 2004; Carlson et al., 2009), chronic in vivo imaging of these arbors during motor learning and disease will likely grant new insight into cerebellar function and dysfunction. Combined with the potential to genetically manipulate the labeled neurons, neonatal viral transduction opens the possibility for experiments probing the relationship between targeted proteins, dendritic morphology, and neuronal function within single cells of the intact brain (O’Connor et al., 2009). Although this technique has many advantages over past methods, several limitations should be noted. First, as mentioned above, the small packaging size of AAV limits the length and number of transgenes that can be co-expressed. In some situations this can be overcome by trans-splicing of co-injected viruses, but this may not

be possible in every setting (Lai et al., 2005; Ghosh & Duan, 2007). Second, widespread transduction may not be ideal when more restricted expression is needed. Where available, spatial or cell-type specificity could be attained using Cre-dependent flex-signal viruses (Atasoy et al., 2008) with Cre-expressing transgenic Thymidine kinase lines (e.g. nagy.mshri.on.ca/). In other cases, selectivity might be achieved using an intersectional strategy of complementary elements introduced on co-injected viruses (Dymecki et al., 2010; Haubensak et al., 2010; Fujimoto et al., 2011). Third, the level of viral gene expression varies between cells due to differences in the multiplicity of infection inherent in viral transgenesis. This fluctuation may complicate some studies of neuronal function, but may be lessened at extremes of high and low titers where infection can be maximised or dilution-limited to a single particle.

At the moment, in S medicae, only the genes actSR have been repo

At the moment, in S. medicae, only the genes actSR have been reported to be necessary for the induction of the adaptive ATR (Glenn et al., 1999). A careful analysis of target genes regulated by this two-component system might shed light on the conditions required, along with the cellular processes that need to be activated, for the ATR in S. meliloti to take place. Although the stability and influence of the ATR on acid tolerance has already been

characterized in rhizobia (O’Hara & Glenn, 1994; Dilworth et al., 1999), no data were available at that time on the effect selleck of the adapted state on symbiosis. To this end, we have shown here that the ATR confers a clear advantage on the rhizobia in the nodulation of the host roots under acidic conditions. From the practical point of view, the results presented here open a new avenue toward the possibility of using acid-adapted (ATR+) rhizobia as inoculants for acidic soils. Such a possibility would point to a consideration of such adapted rhizobia as candidates for an economically sound and biosafe alternative for the improvement of legume inoculation under acidic stress. It will certainly require new experiments with microcosms, and especially in the open field, to evaluate the performance of ATR+ rhizobia Obeticholic Acid concentration within natural soil environments. In addition, new investigations will be necessary that should

be aimed at characterizing the appropriate conditions for stabilizing the positive symbiotic properties of ATR+ rhizobia in long-lasting inoculant formulations. This investigation was supported by grants PIP5701, PICT14562, and PICT31937 to A.L.; and PICT2003-32915, PICT2006-404, and PIP2009-2474 to M.F.D.P., M.P. M.F.D.P., M.P., E.J., and A.L.

are members of the Research Career of CONICET. The authors are grateful to Dr Donald F. Haggerty for editing the manuscript. “
“Streptomycetes Sitaxentan comprise very important industrial bacteria, producing two-thirds of all clinically relevant secondary metabolites. They are mycelial microorganisms with complex developmental cycles that include programmed cell death (PCD) and sporulation. Industrial fermentations are usually performed in liquid cultures (large bioreactors), conditions in which Streptomyces strains generally do not sporulate, and it was traditionally assumed that there was no differentiation. In this work, we review the current knowledge on Streptomyces pre-sporulation stages of Streptomyces differentiation. “
“Microbiology has experienced examples of highly productive researchers who have gone beyond just interpreting their experimental results with hypotheses and published nonsense that was readily recognized as such by readers. Although the most discussed cases of this pathology come from physics, studies of single-celled microorganisms, virology, and immunology have provided many examples. Five cases are described here along with some generalizations.

Approximately two-thirds of all individuals did not exhibit HAND,

Approximately two-thirds of all individuals did not exhibit HAND, and with this bias the method favours accuracy in prediction of this group. However, the preference for HIV management is to predict those with HAND with the extra expense related to extensive neurological testing of those without HAND outweighed by availability of treatment check details to those with NP impairment. We therefore weighted prediction of those with HAND to at least 70% accuracy by duplicating the data from 30 randomly chosen individuals with

HAND and adding these to the original data set. The application of SVM to a data set consists of two steps. The first, called the ‘training phase’, consists of using the SVM on a subset of the data to determine optimal values of the parameters w and γ. The second, called the ‘testing phase’, involves applying this choice of parameters to the remainder of the data set to determine the accuracy of the procedure. The accuracy of the training phase is the percentage of data points within the training set that have . The accuracy of the testing phase is similarly defined. The this website training and testing

phases were conducted using two-thirds of the data randomly chosen for the training set and the remaining one-third for the testing set. As these methods require the selection of tuning parameters such as v in the SVM formulation above, a preliminary training and testing phase was first carried out to determine the tuning parameters

and predictor coefficients w that achieved Liothyronine Sodium maximal testing efficacy. The tuning parameters required in the pq−SVM method were calculated over the grid where [27,28]. The steps of randomly choosing two-thirds of the data for training, the calculation of optimal parameters over the grid of values, and the choice of tuning parameters and predictor coefficients that achieve maximal testing efficiency were then repeated 1000 times. The aim of the repeated simulations was to ensure that there were scenarios that achieved a range of predictive capabilities for those without NP impairment, as we wished to limit the number of false positives. The optimal predictor coefficients for each scenario were determined from the best of these 1000 simulations that also achieved at least 70% efficiency (or closest to this constraint) in predicting those with impairment and those without. We applied the SVM with feature selection to the data for the 97 HIV-positive individuals with advanced disease, 36 of whom had been assessed as having HAND, while the remainder were assessed as not having HAND.

This phenomenon is one of the

This phenomenon is one of the check details major mechanisms of HGT (Llosa & de la Cruz, 2005). According to their transfer ability, conjugative plasmids may be grouped into two categories comprising self-transmissible or mobilizable replicons. The self-transmissible plasmids contain two DNA regions: (1) MOB, which carries genetic information essential for the processing of conjugative DNA, and (2) mating pair formation (MPF), encoding a membrane-associated complex, which is a type 4 secretion system that forms the mating channel (Smillie et al., 2010). Mobilizable plasmids carry only the MOB

module, and their transfer requires an MPF provided by another genetic element co-residing in the cell, that is, a self-transmissible plasmid or integrative and conjugative element, ICE (Smillie et al., 2010). MOB systems are highly conserved and widespread among plasmids (including small cryptic types) commonly found in bacterial isolates (e.g. Bartosik et al., 2002). In this study, we analyzed three small cryptic NHR plasmids (pIGMS31, pIGMS32, and pIGRK) of a pathogenic strain of Klebsiella pneumoniae. The analyses revealed that the plasmids

contain different MOB modules, which function in a wide range Venetoclax order of hosts. This strongly suggests that NHR mobilizable plasmids (similarly as BHR replicons) may play a very important role in the dissemination of genetic information in HGT. Klebsiella pneumoniae 287-w (isolated from the throat of an infant hospitalized in The Children’s Memorial Health Institute in Warsaw) was the host strain of the plasmids pIGMS31, pIGMS32, and pIGRK. The following Escherichia coli strains were employed: (1) DH5α, in plasmid construction (Hanahan, 1983); (2) DH5αR (rifampicin resistant), as a recipient in bi-parental mating (Bartosik et al. 2002); (3) NM522, as a host for plasmids in in vitro transposition (Stratagene); (4)

S17-1, as a donor in bi-parental mating (Simon et al., 1983); and (5) TG1, in plasmid construction. The following rifampicin- or Thymidylate synthase streptomycin-resistant strains were used in the host range analysis: (1) Agrobacterium tumefaciens LBA1010 (Rifr; Koekman et al., 1982); (2) Brevundimonas sp. LM18R (Rifr); (3) Paracoccus aminovorans JCM 7685 (Rifr); and (4) Rhizobium etli CE3 (Strr; Noel et al., 1984) – all members of the Alphaproteobacteria; as well as (4) Serratia sp. OS9 (Gammaproteobacteria; Drewniak et al., 2008, 2010). Bacteria were grown in lysogeny broth (LB) medium (Sambrook & Russell, 2001) or TY medium (R. etli) (Beringer, 1974) at 37 °C (E. coli) or 30 °C (other strains). When necessary, the medium was supplemented with antibiotics at the following concentrations: ampicillin – 100 μg mL−1; kanamycin – 50 μg mL−1; rifampicin – 50 μg mL−1; streptomycin – 50 μg mL−1 (E. coli S17-1) or 100 μg mL−1 (R. etli CE3); and tetracycline – 20 μg mL−1. The plasmids used in this study are listed in Table 1.

0% to the 16S

0% to the 16S www.selleckchem.com/products/AC-220.html rRNA gene sequence of strain MSSRF38T. The topology of the phylogenetic tree built using the maximum-parsimony algorithm was similar to those of the tree constructed using neighbour-joining analysis (Fig. 1). Recently, sequencing of housekeeping genes has been proved to be useful to determine the phylogenetic relationships among microorganisms. For the family Vibrionaceae, different loci, for example gapA, gyrB, recA, rpoA, pyrH, atpA and dnaJ, have been studied in the search for a useful phylogenetic marker capable of delineating Vibrio species (Thompson et al.,

2005; Ramesh Kumar & Nair, 2007; Sawabe et al., 2007; Rameshkumar et al., 2008). For the present analysis, we used four housekeeping genes, ftsZ, gyrB, gapA and mreB, in order to verify the taxonomic position of strain MSSRF38T. The phylogenetic tree based on ftsZ, gyrB,

gapA and mreB gene sequences confirmed the clustering of strain MSSRF38T along with the type strains of species of the V. gazogenes group with high bootstrap support values and revealed its distinct phylogenetic position (Figs S1–S4). Furthermore, sequence analysis of ftsZ, gyrB, gapA and mreB genes showed that strain MSSRF38T had relatively low gene similarities (<92%, <87%, <90% and <86%) to its closest relatives (Table 1), as all these similarity values were lower than the intraspecies variation in the genus Vibrio (Sawabe et al., 2007), indicating a separate species status for strain MSSRF38T. In addition, a multigene phylogenetic tree was constructed for strain MSSRF38T using these four genes (mreB, gyrB, gapA and ftsZ). This analysis also showed that the selleck screening library strain MSSRF38T occupies a distinct phylogenetic position by not clustering with any type strain of the V. gazogenes group (Fig. 2). This result again reinforced our conclusion that strain MSSRF38T deserves the status of a separate species. Supporting our taxonomic conclusion on strain MSSRF38T, the level

of DNA relatedness between strain MSSRF38T and V. ruber DSM 16370T was 27.4% not (27.8%) and that between strain MSSRF38T and V. rhizosphaerae DSM 18581T was 12.1% (17.4%). The values in parentheses are the results of measurements in duplicate. This level of DNA relatedness is well below the recommended 70% genomic relatedness used to delineate species (Wayne et al., 1987). It can be concluded that strain MSSRF38T does not belong to those species. Because it was found that species with <97% similarity at the 16S rRNA gene sequence level show <70% genomic relatedness (Stackebrandt & Goebel, 1994), DNA–DNA hybridization with the type strains of other species of the V. gazogenes group was not included. Our study further confirms the fact that Vibrio strains that have housekeeping gene similarities lower than 95% (recA, pyrH, rpoA, mreB, gyrB, gapA and ftsZ) will have <70% DNA–DNA similarity (Thompson et al., 2004, 2005; Ramesh Kumar & Nair, 2007; Sawabe et al.

There is considerable variability in early visual cortical geomet

There is considerable variability in early visual cortical geometry between individuals, and locations for which reliable C1 components can be elicited are participant-specific (Kelly et al., 2008). However, we did have to present stimuli in the same stimulus locations for all participants to this website be able to examine the topographic distribution of attentional modulation. Therefore, not all stimulus locations were optimal for observing C1 modulations. The amplitude in the time-frame of the early components was extracted for each participant by use of the mean of a 20-ms window (C1)

and a 30-ms window (P1) centered on the peak of the grand average. For C1, the time range was 65–85 ms, and for P1 it was 110–140 ms. These amplitudes

Galunisertib ic50 were analysed with repeated measures anova (spss v.21.0), with attention (attended/unattended) and spotlight (split/non-split) as factors, and location (inner/outer) as a covariate. An important aspect of providing evidence for a divided spotlight of attention is to examine the ‘landscape’ of attentional modulation during the task (Jans et al., 2010). In the current study, we examined the topographic distribution of attentional suppression for the different experimental conditions, because enhancing and suppressive effects of attention are tightly linked very (Pinsk et al., 2004; Frey et al., 2010). Brain oscillations in the alpha (8–14 Hz) range are known to index attentional suppression of regions of visual space (Foxe et al., 1998; Worden et al., 2000; Romei et al., 2010; Foxe & Snyder, 2011), and the topography of alpha power reflects which part of visual space needs to be ignored (Rihs et al., 2007). As experimental trials were > 2 s in length, we were able to analyse alpha amplitude and its topography concurrently with evoked activity. Alpha oscillations are not expected

to be differentially affected by the m-sequence, as the flickering was present in all conditions, and only task demands were varied. For determination of alpha amplitude, EEG trial data were filtered between 8 and 13 Hz by use of a fourth-order Butterworth filter. These band-pass-filtered data were Hilbert-transformed, and the absolute value was taken. We removed the first and last 100 ms of data of each trial, because these contained edge artefacts of the filter. For each time-point, the average of all different conditions was used as the baseline. For the display of alpha topographies, the remaining 1.9 s was averaged in order to yield one amplitude value per channel and trial. Alpha topographies were normalised (z-score) for every participant, and the grand average of z-scores across participants was displayed.

1), streptococcal culture

1), streptococcal culture JNK inhibitor supernatants were harvested

by centrifugation exactly at the mid log phase (A600 = 0.6–0.7) (Svensson et al., 2002). In addition, to ensure the absence of the zymogene (40 kDa) and active form (28 kDa) of the SpeB protease, the proteins of mid log phase culture supernatants were precipitated using 100% trichloroacetic acid and were evaluated by standard 12% SDS-PAGE and Coomassie blue staining (Svensson et al., 2002). The culture supernatants were subsequently filtered through 0.22-μm filter (Whatman, Germany) and stored at −70 °C until use. For each colorimetric assay, 50 μL of the culture supernatant was incubated at 37 °C with 100 μL 50 mM Tris–HCl, pH 7.4 in microplate containing 50 μg mL−1 of human Plg (Sigma) for 15 min. The S-2251 substrate (50 μL of 2.5 mM) was added, and absorbance was measured at 405 nm every 5 min for 60 min. Each assay was performed in duplicate, both in the presence and absence of Plg/S-2251. Assays containing the intact (unused) THB media and culture supernatants of the reference strains were also employed as negative and positive controls, respectively. Serial dilutions of Streptase® (CSL, Behring, Germany), a commercial SK, were used to prepare the standard curve for

SK Ribociclib datasheet activity. Optical densities were plotted against time, and activity rates were determined from linear portion of the curve. The level of SK activity in each bacterial culture supernatant was converted to IU mL−1 using the standard curve. The PCR product of a representative of each digestion pattern (Fig. 1) was selected for nucleotide sequencing. DNA sequencing data were used for alignment studies and restriction site mapping via application Rutecarpine of the Molecular Evolutionary Genetic Analysis (mega 4) analytical package (Tamura et al., 2007). Difference in SK activities among GAS and GCS/GGS groups was determined using the one-way

anova test. The Kruskal–Wallis analysis of variance was employed to calculate the level of significance of SK activity among variants. All statistical analyses were carried out using spss version 16.0 (SPSS, Inc., Chicago, IL). A value of P < 0.05 was considered significant. PCR-based amplification of the sk-V1 region produced the expected 339-bp fragments (Fig. 1). Digestion of the PCR products (sk-V1) by MluI, PvuII, DraI and DdeI restriction enzymes also provided exactly the earlier described restriction patterns of the DNA fragments (Tewodros et al., 1996) (Fig. 1, Supporting Information, Table S1). The reference strains GCS/GGS and NZ131 were classified as sk5 and sk1, respectively, as expected. In total, 21 sk allelic variants were detected among strains investigated in our study (Fig. 2). Besides the several previously reported sk allelic variants of GAS and GCS/GGS isolates (Tewodros et al.

parahaemolyticus is c 30 nm and 15 nm for the lateral filament (

parahaemolyticus is c. 30 nm and 15 nm for the lateral filament (McCarter, 2004). In contrast, type IV pili are much thinner and show a diameter that ranges between 50 and 80 Å (Craig et al., 2004). We also analyzed the ion preference for the rotation of both flagella. This was achieved by including amiloride in 0.3% or 0.5% soft agar plates. At 0.3% agar, motility is mediated by the polar ERK inhibitor solubility dmso flagellum and it is drastically reduced by amiloride, indicating that the polar flagellum is driven by Na+ ions. In contrast at 0.5% agar, motility in the presence of

amiloride was slightly reduced, suggesting that at this agar concentration, V. shilonii swarms using mainly lateral flagella. Hence, presumably, protons drive lateral flagella, given that swarming is insensitive to the presence of amiloride. As mentioned, the presence of lateral flagella correlates with an increase in density at an agar concentration of 0.5%; however, the alternative use of Na+ and H+ gradients for cell motility in V. shilonii is an issue that remains to be further explored. In this work, we also analyzed the subunit composition of the isolated HBB

complex of the polar flagellum of this bacterium. The internal sequences of eight flagellar proteins were obtained by MS. These correspond to three different flagellins (FlaA, FlaB and FlaC), the hook protein (FlgE), the PARP activation L-ring protein (FlgH), the MS-ring protein (FliF), a rod protein (FlgG) and the Na+-driven motor component (MotY). The genes encoding these proteins were identified in the complete genome of V. shilonii. We determined

that six of these sequences are encoded by genes located in what we have named flagellar region I. FlgG is encoded in flagellar region III and MotY is encoded by a gene in an unlinked region. The finding that the polar flagellum contains an FlgG from a different Nintedanib (BIBF 1120) flagellar locus was unexpected, given that flagellar region I also includes an flgG gene. Furthermore, the FlgG protein encoded in region I shows 95% similarity to FlgG from the polar flagellum of V. parahaemolyticus, whereas FlgG encoded in region III shows a lower similarity (66%). It remains to be elucidated whether other components of the polar flagellum could be encoded in region III. In this regard, it should be noted that flagellar region I does not include genes homologous to pomA and pomB. The motor proteins of the polar flagellum may correspond to those encoded in the flagellar region III or may be encoded by a bicistronic operon, which is unlinked to the flagellar regions described above and spans from positions 4 290 113 to 4 291 852 (see Fig. S1). According to our sequence analysis, the flagellar genes located in region II are highly similar to lateral flagellar genes that have been characterized previously in other Vibrio species. Hence, the lateral flagellum of V. shilonii would presumably be encoded by flagellar genes located in region II (2 985 403–3 021 130) (Fig. S1).