Fast and friendly: The role of vocal cues in adolescents' responses to and perceptions of peer provocation.

Adolescents self-report using different strategies to respond to peer provocation. However, we have a limited understanding of how these responses are behaviorally enacted and perceived by peers. This study examined the extent to which adolescents' self-reported responses to peer provocation (i.e., aggressive, assertive, and withdrawn) predicted how their vocal enactments of standardized responses to peer provocation were perceived by other adolescents. Three vocal cues relevant to the communication of emotional intent-average pitch, average intensity, and speech rate-were explored as moderators of these associations. Adolescent speakers (n = 39; Mage = 12.67; 66.7% girls) completed a self-report measure of how they would choose to respond to scenarios involving peer provocation; they also enacted standardized vocal responses to hypothetical peer provocation scenarios. Recordings of speakers' vocal responses were presented to a separate sample of adolescent listeners (n = 129; Mage = 12.12; 52.7% girls) in an online listening task. Speakers who self-reported greater use of assertive response strategies enacted standardized vocal responses that were rated as significantly friendlier by listeners. Vocal responses enacted with faster speech rates were also rated as significantly friendlier by listeners. Speakers' self-reported use of aggression and withdrawal was not significantly related to listeners' ratings of their standardized vocal responses. These findings suggest that adolescents may be perceived differently by their peers depending on the way in which their response is enacted; specifically, faster speech rate may be perceived as friendlier and thus de-escalate peer conflict. Future studies should consider not only what youth say and/or do when responding to peer provocation but also how they say it.

Symbiosis islands of Loteae-nodulating Mesorhizobium comprise three radiating lineages with concordant nod gene complements and nodulation host-range groupings.

Mesorhizobium is a genus of soil bacteria, some isolates of which form an endosymbiotic relationship with diverse legumes of the Loteae tribe. The symbiotic genes of these mesorhizobia are generally carried on integrative and conjugative elements termed symbiosis islands (ICESyms). Mesorhizobium strains that nodulate Lotus spp. have been divided into host-range groupings. Group I (GI) strains nodulate L. corniculatus and L. japonicus ecotype Gifu, while group II (GII) strains have a broader host range, which includes L. pedunculatus. To identify the basis of this extended host range, and better understand Mesorhizobium and ICESym genomics, the genomes of eight Mesorhizobium strains were completed using hybrid long- and short-read assembly. Bioinformatic comparison with previously sequenced mesorhizobia genomes indicated host range was not predicted by Mesorhizobium genospecies but rather by the evolutionary relationship between ICESym symbiotic regions. Three radiating lineages of Loteae ICESyms were identified on this basis, which correlate with Lotus spp. host-range grouping and have lineage-specific nod gene complements. Pangenomic analysis of the completed GI and GII ICESyms identified 155 core genes (on average 30.1 % of a given ICESym). Individual GI or GII ICESyms carried diverse accessory genes with an average of 34.6 % of genes unique to a given ICESym. Identification and comparative analysis of NodD symbiotic regulatory motifs - nod boxes - identified 21 branches across the NodD regulons. Four of these branches were associated with seven genes unique to the five GII ICESyms. The nod boxes preceding the host-range gene nodZ in GI and GII ICESyms were disparate, suggesting regulation of nodZ may differ between GI and GII ICESyms. The broad host-range determinant(s) of GII ICESyms that confer nodulation of L. pedunculatus are likely present amongst the 53 GII-unique genes identified.

Multiple introductions of methicillin-resistant Staphylococcus aureus ST612 into Western Australia associated both with human and equine reservoirs.

Staphylococcus aureus is a serious human and animal pathogen. Multilocus sequence type 612 (ST612) is the dominant methicillin-resistant S. aureus (MRSA) clone in certain South African hospitals and is sporadically isolated from horses and horse-associated veterinarians in Australia. Colonisation and infection by ST612-MRSA is increasing in Western Australia. Whole-genome sequencing was performed for 51 isolates of ST612-MRSA from Western Australian patients and healthcare workers, South African hospital patients, Australian veterinarians and New South Wales horses. Core genome phylogenies suggested that Australian equine and veterinarian-associated ST612-MRSA were monophyletic. Individual Western Australian isolates grouped either with this equine-associated lineage or more diverse lineages related to those in South African hospitals. Bioinformatic analyses of the complete ST612-MRSA reference genome SVH7513 confirmed that ST612-MRSA was closely related to ST8 USA500 MRSA. Common use of rifampicin in South Africa and equine veterinarian practice may favour ST612-MRSA in these settings. Humans and horses colonised with ST612-MRSA are potential reservoirs for MRSA in Australia.

Complete Genome Sequence of a Staphylococcus aureus Sequence Type 612 Isolate from an Australian Horse.

Staphylococcus aureus is a serious pathogen of humans and animals. Multilocus sequence type 612 is dominant and highly virulent in South African hospitals but relatively uncommon elsewhere. We present the complete genome sequence of methicillin-resistant Staphylococcus aureus strain SVH7513, isolated from a horse at a veterinary clinic in New South Wales, Australia.

Survival of antibiotic resistant bacteria following artificial solar radiation of secondary wastewater effluent.

Urban wastewater treatment plant effluents represent one of the major emission sources of antibiotic-resistant bacteria (ARB) in natural aquatic environments. In this study, the effect of artificial solar radiation on total culturable heterotrophic bacteria and ARB (including amoxicillin-resistant, ciprofloxacin-resistant, rifampicin-resistant, sulfamethoxazole-resistant, and tetracycline-resistant bacteria) present in secondary effluent was investigated. Artificial solar radiation was effective in inactivating the majority of environmental bacteria, however, the proportion of strains with ciprofloxacin-resistance and rifampicin-resistance increased in the surviving populations. Isolates of Pseudomonas putida, Serratia marcescens, and Stenotrophomonas maltophilia nosocomial pathogens were identified as resistant to solar radiation and to at least three antibiotics. Draft genome sequencing and typing revealed isolates carrying multiple resistance genes; where S. maltophilia (resistant to all studied antibiotics) sequence type was similar to strains isolated in blood infections. Results from this study confirm that solar radiation reduces total bacterial load in secondary effluent, but may indirectly increase the relative abundance of ARB.

Draft Genome Sequence of Acidihalobacter ferrooxidans DSM 14175 (Strain V8), a New Iron- and Sulfur-Oxidizing, Halotolerant, Acidophilic Species.

The use of halotolerant acidophiles for bioleaching provides a biotechnical approach for the extraction of metals from regions where high salinity exists in the ores and source water. Here, we describe the first draft genome of a new species of a halotolerant and iron- and sulfur-oxidizing acidophile, Acidihalobacter ferrooxidans DSM 14175 (strain V8).

Draft Genome Sequence of the Acidophilic, Halotolerant, and Iron/Sulfur-Oxidizing Acidihalobacter prosperus DSM 14174 (Strain V6).

The principal genomic features of Acidihalobacter prosperus DSM 14174 (strain V6) are presented here. This is a mesophilic, halotolerant, and iron/sulfur-oxidizing acidophile that was isolated from seawater at Vulcano, Italy. It has potential for use in biomining applications in regions where high salinity exists in the source water and ores.

An updated view of plasmid conjugation and mobilization in Staphylococcus.

The horizontal gene transfer facilitated by mobile genetic elements impacts almost all areas of bacterial evolution, including the accretion and dissemination of antimicrobial-resistance genes in the human and animal pathogen Staphylococcus aureus. Genome surveys of staphylococcal plasmids have revealed an unexpected paucity of conjugation and mobilization loci, perhaps suggesting that conjugation plays only a minor role in the evolution of this genus. In this letter we present the DNA sequences of historically documented staphylococcal conjugative plasmids and highlight that at least 3 distinct and widely distributed families of conjugative plasmids currently contribute to the dissemination of antimicrobial resistance in Staphylococcus. We also review the recently documented "relaxase-in trans" mechanism of conjugative mobilization facilitated by conjugative plasmids pWBG749 and pSK41, and discuss how this may facilitate the horizontal transmission of around 90% of plasmids that were previously considered non-mobilizable. Finally, we enumerate unique sequenced S. aureus plasmids with a potential mechanism of mobilization and predict that at least 80% of all non-conjugative S. aureus plasmids are mobilizable by at least one mechanism. We suggest that a greater research focus on the molecular biology of conjugation is essential if we are to recognize gene-transfer mechanisms from our increasingly in silico analyses.

Origin-of-transfer sequences facilitate mobilisation of non-conjugative antimicrobial-resistance plasmids in Staphylococcus aureus.

Staphylococcus aureus is a common cause of hospital, community and livestock-associated infections and is increasingly resistant to multiple antimicrobials. A significant proportion of antimicrobial-resistance genes are plasmid-borne, but only a minority of S. aureus plasmids encode proteins required for conjugative transfer or Mob relaxase proteins required for mobilisation. The pWBG749 family of S. aureus conjugative plasmids can facilitate the horizontal transfer of diverse antimicrobial-resistance plasmids that lack Mob genes. Here we reveal that these mobilisable plasmids carry copies of the pWBG749 origin-of-transfer (oriT) sequence and that these oriT sequences facilitate mobilisation by pWBG749. Sequences resembling the pWBG749 oriT were identified on half of all sequenced S. aureus plasmids, including the most prevalent large antimicrobial-resistance/virulence-gene plasmids, pIB485, pMW2 and pUSA300HOUMR. oriT sequences formed five subfamilies with distinct inverted-repeat-2 (IR2) sequences. pWBG749-family plasmids encoding each IR2 were identified and pWBG749 mobilisation was found to be specific for plasmids carrying matching IR2 sequences. Specificity of mobilisation was conferred by a putative ribbon-helix-helix-protein gene smpO. Several plasmids carried 2-3 oriT variants and pWBG749-mediated recombination occurred between distinct oriT sites during mobilisation. These observations suggest this relaxase-in trans mechanism of mobilisation by pWBG749-family plasmids is a common mechanism of plasmid dissemination in S. aureus.

Polycyclic aromatic hydrocarbon (PAH) emissions from a coal-fired pilot FBC system.

Due to the extensive amount of data suggesting the hazards of these compounds, 16 polycyclic aromatic hydrocarbons (PAHs) are on the Environmental Protection Agency (EPA) Priority Pollutant List. Emissions of these PAHs in the flue gas from the combustion of four coals were measured during four 1000h combustion runs using the 0.1MW heat-input (MWth) bench-scale fluidized bed combustor (FBC). An on-line sampling system was designed for the 16 PAHs, which consisted of a glass wool filter, condenser, glass fiber filter, Teflon filter, and a Tenax trap. The filters and Tenax were extracted by methylene chloride and hexane, respectively, followed by GC/MS analysis using the selective ion monitoring (SIM) mode. In this project, the effects of operating parameters, limestone addition, chlorine content in the coal, and Ca/S molar ratio on the emissions of PAHs were studied. The results indicated that the emissions of PAHs in an FBC system are primarily dependent on the combustion temperature and excess air ratio. The injection of secondary air with high velocity in the freeboard effectively reduces PAH emissions. The addition of extra limestone can promote the formation of PAHs in the FBC system. Chlorine in the coal can possibly lead to large benzene ring PAH formation during combustion. The total PAH emission increases with an increase in the sulfur content of coal. Incomplete combustion results in PAHs with four or more benzene rings. High efficiency combustion results in PAHs with two or three benzene rings.

Soluble polycyclic aromatic hydrocarbons in raw coals.

Polycyclic aromatic hydrocarbons (PAHs) are considered to be a group of compounds that pose potential health hazards since some PAHs are known carcinogens. During coal utilization processes, such as coal combustion and pyrolysis, PAHs released may be divided into two categories according to their formation pathways. One category is derived from complex chemical reactions and the other is from free PAHs transferred from the original coals. PAHs released from complex chemical reactions during combustion and pyrolysis have received considerable attention in recent years. However, free PAHs contained in raw coals have not been seriously considered as a source of these materials to be released during the utilization of coal. The goal of this study was to observe the relation between the content of PAHs in different coals and the elemental composition of the coals. In this study, eight bituminous coals with dry, ash-free carbon values varying from 65% to 90% were selected. Each coal was extracted with dichloromethane in a Soxhlet extractor for 6 h. The extracts were quantitatively analyzed with a gas chromatograph/mass spectrometer (GC-MS). More than 20 kinds of PAHs were identified. The total amount of PAHs determined varied from 1.2 to 28.3 mg/kg from the various coal types. The maximum total PAHs extracted was reached when the carbon content exceeded 84% by weight.