Transmissions: Element 120 Portable
RIGGING HARDWARE AND ACCESSORIESThanks to the elegant mechanical design the AX12C can be easily transported, while the integrated suspension system makes its deployment very fast and simple. Each unit comes with two aluminum brackets and four pins that allows multiple array elements to be easily combined either together or with the matching SW2100A subwoofer. The brackets allow two inter-cabinet angles of 0 and 2.A complete range of accessories for transport, installation and connections are available.
Transmissions: Element 120 Portable
The Galaxy Trek portable lavalier microphone system is powered by long lasting internal lithium batteries located in both the transmitter and receiver. Charging is quick and easy with the included micro USB cable. The system also includes two adapter cables for both Android and Apple iOS smart devices.
It is commonly assumed that the horizontal transfer of most bacterial chromosomal genes is limited, in contrast to the frequent transfer observed for typical mobile genetic elements. However, this view has been recently challenged by the discovery of lateral transduction in Staphylococcus aureus, where temperate phages can drive the transfer of large chromosomal regions at extremely high frequencies. Here, we analyse previously published as well as new datasets to compare horizontal gene transfer rates mediated by different mechanisms in S. aureus and Salmonella enterica. We find that the horizontal transfer of core chromosomal genes via lateral transduction can be more efficient than the transfer of classical mobile genetic elements via conjugation or generalized transduction. These results raise questions about our definition of mobile genetic elements, and the potential roles played by lateral transduction in bacterial evolution.
Phages and their counterparts, the phage-inducible chromosomal islands (PICIs)8,9,10 are also key components of the mobilome and are important mediators of HGT. These elements readily transmit between host bacteria, where they can integrate into the bacterial chromosome and replicate passively during cell division. As new residents of a host cell, they can offer lysogenic immunity against phage superinfection or they can bestow important virulence phenotypes by introducing genes for toxins and colonisation factors11,12. In addition to mobilising their own DNA, phages can also mediate the exchange of bacterial DNA at very low frequencies through the processes of specialised and generalised transduction (ST and GT). Specialised transducing particles transmit restricted parts of the host chromosome, and they are formed by irregular prophage excision events that result in hybrid phage genomes that include bacterial DNA adjacent to phage attachment sites13,14. GT can transmit any bacterial DNA, and it occurs when host DNA is packaged into capsids at the expense of phage DNA to form transducing particles that inject their DNA cargo into a new host cell, where it can recombine into the host chromosome or exist as a plasmid13,15. GT is primarily mediated by pac-type phages, which package DNA by the headful mechanism. DNA packaging into transducing particles is initiated by the phage small terminase (TerS) at pseudo-pac (ppac) sites, which are sequences that resemble phage pac sites. These motifs are scattered throughout bacterial chromosomal and plasmid DNA and are recognised with varying frequencies that reflect their level of homology with bone fide pac sites13.
While the mobilome seemed to be well defined, the broader concept of genetic mobility in bacteria is no longer well defined, as it has recently been upended by the discovery of the third and most powerful mode of phage-mediated DNA transfer: lateral transduction (LT)16. The LT mechanism begins with early in situ prophage replication, which creates multiple integrated prophages for genomic redundancy. Some prophages excise and enter the productive lytic cycle, while others serve as substrates for in situ DNA packaging from their embedded pac sites, which are recognised far more efficiently than ppac sites (used in GT). When the first headful of DNA has been reached, the processive terminase enzyme continues to fill many more capsids with bacterial chromosome, which are subsequently transferred at high frequencies16 (Fig. 1) and can then be integrated into the recipient genome by homologous recombination (HR). We propose here that when the full impact of this mechanism is considered, the classical dichotomy of portable MGEs and immobile chromosomes will no longer hold true because chromosomal genes can be mobilised at frequencies equal to or higher than elements normally regarded as mobile. To explore this idea, we looked to Staphylococcus aureus and Salmonella spp. as our reference organisms because their MGEs have been widely studied and they serve as model organisms for the mechanism of LT. We show that, via phage-mediated lateral transduction, the mobility of core genes in bacterial chromosomes can exceed that of elements classically considered to be mobile.
The Staphylococcal genomic islands (GI) νSaα, vSaβ, and vSaγ are pathogenicity islands of DNA located within the S. aureus chromosome that encode a wide variety of genes involved in Staphylococcal virulence, including enterotoxins, serine proteases and leukotoxins22. Carriage of vSaα and vSaβ occurs widely among S. aureus strains23, with many strains also harbouring the third GI, vSaγ24. The absence of vSaγ from some strains strongly suggests that these elements have been obtained by S. aureus via HGT, with vSaγ being the most recent acquisition. Until recently, however, no mechanism had been ascribed that was able to satisfactorily explain how this widely spread TE could occur in nature. We believe that the discovery of LT provides an elegant mechanism explaining how such transfers can be facilitated at high frequency. Our reasoning for this is twofold: firstly, it is striking that each of the GIs is located in the S. aureus chromosome such that it is close to a prophage integration site (attB) in the direction of phage packaging, permitting compatibility with packaging and transfer via phage-mediated LT: vSaα is located downstream of the Sa6 prophage attB, compatible with packaging into HF3; vSaγ is located close (within two headfuls) to Sa7 attB, and is also compatible with packaging from Sa4 (HF4-5) and Sa1 (HF7) prophage attachment sites; while vSaβ is located close to attachment sites Sa8 (HF1-2), Sa5 (HF2-3), as well as Sa3 (HF5-6)16. Secondly, two recent studies have demonstrated a role for staphylococcal prophages in the transduction of the GI24,25. Notably, the first of these studies showed transduction of vSaβ mediated by a prophage integrated at the Sa8 attachment site adjacent to the island. In this study, the authors describe phage-mediated transduction of the island via a complex double transduction event, where they speculate that overlapping sections of DNA from multiple transducing particles result in the transfer of vSaβ via HR25. It is interesting, however, that the authors describe transducing particles containing phage-vSaβ hybrid sections of DNA, a feature that is now known to be observed in HF1 of LT particles, suggesting the potential involvement of LT in the process of vSaβ mobilisation. In addition, the authors found a positive correlation between the presence of both vSaβ and a phage localised adjacent to the island among a panel of bovine S. aureus isolates, further suggesting a potential role for phage-mediated LT in the dissemination of this GI.
Source data is available in the accompanying excel file. For all data derived from published literature, the source is indicated as a citation in the manuscript. Accession numbers relating to each element analysed are included in the manuscript (Tables 1 and 3), where they were available. Source data are provided with this paper.
If you use a portable electronic device while you drive (except to call 911 or to contact medical, fire or police personnel about an emergency), you can receive a traffic ticket and be subject to a fine and a surcharge.
Conviction of a cell phone use, portable electronic device use or a texting violation will also result in points being added to your DMV driving record. If you receive 11 points in an 18 month period, your driver license may be suspended. To learn more, see About the NY State Driver Point System.
An antenna structure includes a main radiation element, a first feeding element, a first additional radiation element, a dielectric substrate, and a ground plane. A first signal source is coupled through the first feeding element to a first side of the main radiation element. The first additional radiation element is coupled to a second side of the main radiation element. A first slot is formed between the first additional radiation element and the main radiation element. The second side is different from the first side. The dielectric substrate has a first surface and a second surface which are opposite to each other. The main radiation element, the first feeding element, and the first additional radiation element are disposed on the first surface of the dielectric substrate. The ground plane is adjacent to the second surface of the dielectric substrate.
3. The antenna structure as claimed in claim 1, wherein the main radiation element substantially has a rectangular shape or a square shape with a first corner, a second corner, a third corner, and a fourth corner.
5. The antenna structure as claimed in claim 3, wherein the first additional radiation element has a first end coupled to the first corner of the main radiation element, and a second end coupled to the second corner of the main radiation element.
6. The antenna structure as claimed in claim 1, wherein the first additional radiation element comprises a body portion, a first connection portion, and a second connection portion, and the body portion is coupled between the first connection portion and the second connection portion.