We hypothesized that the incubation for urethral gonorrhoea would be longer for men with oropharyngeal gonorrhoea than those without oropharyngeal gonorrhoea. We conducted a chart review of men who have sex with men with urethral gonorrhoea symptoms at a sexual health clinic between 2019 and 2021. The incubation period was defined as the number of days between men’s last sexual contact and onset of symptoms. We used a Mann–Whitney U test to compare differences in the median incubation for urethral gonorrhoea between men with and men without oropharyngeal gonorrhoea. There were 338 men with urethral symptoms (median age = 32 years; IQR: 28–39), and of these, 307 (90.1%) were tested for oropharyngeal gonorrhoea, of whom 124 (40.4%, 95% CI: 34.9–46.1) men had oropharyngeal and urethral gonorrhoea. We analyzed incubation data available for 190 (61.9%) of the 307 men, with 38.9% (74/190) testing positive for oropharyngeal gonorrhoea. The incubation for urethral gonorrhoea did not differ between 74 men (39%) with oropharyngeal gonorrhoea (median = 4 days; IQR: 2–6) and 116 men (61%) without oropharyngeal gonorrhoea (median = 2.5 days; IQR: 1–5) (p = 0.092). Research is needed to investigate gonorrhoea transmission from the oropharynx to the urethra.

Background: A significant proportion of glioblastoma multiforme (GBM) patients are considered for repeat resection, but evidence regarding best management remains elusive. Methods: An electronic portfolio of MR images of 37 cases of pathologically confirmed recurrent GBM with an accompanying clinical vignette was constructed. Surgical responders from various countries, training backgrounds, and years’ experience were asked for each case to select: their chosen management (repeat surgery, chemotherapy, radiation, or conservative), confidence in recommended management, and whether they would include the patient in a randomized trial that gave a 50% chance of re-operation. Responses were evaluated with kappa statistics and values interpreted according to Landis and Koch (0–0.2, slight; 0.21–0.4, fair; 0.41–0.6, moderate; 0.61–0.8, substantial; 0.81-1.0 perfect agreement). Results: 26 surgeons responded to the survey. Agreement regarding best management of recurrent GBM was slight, even when management options were dichotomized (repeat surgery vs. all others) (k=0.198 (95%CI 0.133-0.276). Country of practice, years’ experience, and training background did not improve agreement. Responders were willing to include more than 70% of patients in a randomized trial. Conclusions: Only slight agreement exists regarding the question of re-operation for patients with recurrent GBM. This supports the need for a randomized controlled trial.

In this paper, we describe the system design and capabilities of the Australian Square Kilometre Array Pathfinder (ASKAP) radio telescope at the conclusion of its construction project and commencement of science operations. ASKAP is one of the first radio telescopes to deploy phased array feed (PAF) technology on a large scale, giving it an instantaneous field of view that covers $31\,\textrm{deg}^{2}$ at $800\,\textrm{MHz}$. As a two-dimensional array of 36$\times$12 m antennas, with baselines ranging from 22 m to 6 km, ASKAP also has excellent snapshot imaging capability and 10 arcsec resolution. This, combined with 288 MHz of instantaneous bandwidth and a unique third axis of rotation on each antenna, gives ASKAP the capability to create high dynamic range images of large sky areas very quickly. It is an excellent telescope for surveys between 700 and $1800\,\textrm{MHz}$ and is expected to facilitate great advances in our understanding of galaxy formation, cosmology, and radio transients while opening new parameter space for discovery of the unknown.

Gravitational waves from coalescing neutron stars encode information about nuclear matter at extreme densities, inaccessible by laboratory experiments. The late inspiral is influenced by the presence of tides, which depend on the neutron star equation of state. Neutron star mergers are expected to often produce rapidly rotating remnant neutron stars that emit gravitational waves. These will provide clues to the extremely hot post-merger environment. This signature of nuclear matter in gravitational waves contains most information in the 2–4 kHz frequency band, which is outside of the most sensitive band of current detectors. We present the design concept and science case for a Neutron Star Extreme Matter Observatory (NEMO): a gravitational-wave interferometer optimised to study nuclear physics with merging neutron stars. The concept uses high-circulating laser power, quantum squeezing, and a detector topology specifically designed to achieve the high-frequency sensitivity necessary to probe nuclear matter using gravitational waves. Above 1 kHz, the proposed strain sensitivity is comparable to full third-generation detectors at a fraction of the cost. Such sensitivity changes expected event rates for detection of post-merger remnants from approximately one per few decades with two A+ detectors to a few per year and potentially allow for the first gravitational-wave observations of supernovae, isolated neutron stars, and other exotica.

NGC 7469 is a well-known type 1 AGN with a cirumnuclear star formation ring. It has previous detections of X-rays warm absorbers and an infrared biconical outflow. We analysed archival MUSE/VLT observations of this galaxy in order to look for an optical counterpart of these outflows. We report spatially resolved winds in the [O III] λ5007 emission line in two regimes: a high velocity regime possibly associated with the AGN and a slower one associated with the massive star formation of the ring. This slower regime is also detected with Hβ.

On 30 May 2012, Surrey and Sussex Health Protection Unit was called by five nurseries reporting children and staff with sudden onset vomiting approximately an hour after finishing their lunch that day. Over the following 24 h 50 further nurseries supplied by the same company reported cases of vomiting (182 children, 18 staff affected). Epidemiological investigations were undertaken in order to identify the cause of the outbreak and prevent further cases. Investigations demonstrated a nursery-level attack rate of 55 out of 87 nurseries (63·2%, 95% confidence interval 52·2–73·3). Microbiological tests confirmed the presence of Bacillus cereus in food and environmental samples from the catering company and one nursery. This was considered microbiologically and epidemiologically consistent with toxin from this bacterium causing the outbreak. Laboratory investigations showed that the conditions used by the caterer for soaking of pearl haricot beans (known as navy bean in the USA) used in one of the foods supplied to the nurseries prior to cooking, was likely to have provided sufficient growth and toxin production of B. cereus to cause illness. This large outbreak demonstrates the need for careful temperature control in food preparation.

The rapid rise in syphilis cases has prompted a number of public health campaigns to assist men who have sex with men (MSM) recognize and present early with symptoms. This study aimed to investigate the temporal trend of the duration of self-report symptoms and titre of rapid plasma reagin (RPR) in MSM with infectious syphilis. Seven hundred and sixty-one syphilis cases in MSM diagnosed at the Melbourne Sexual Health Centre (MSHC) from 2007–2013 were reviewed. Median duration of symptoms and RPR titres in each year were calculated. The median durations of symptoms with primary and secondary syphilis were 9 [interquartile range (IQR) 6–14] days and 14 (IQR 7–30) days, respectively. The overall median titre of RPR in secondary syphilis (median 128, IQR 64–256) was higher than in primary syphilis (median 4, IQR 1–32) and in early latent syphilis (median 32, IQR 4–64). The median duration of symptoms for primary syphilis, secondary syphilis and titre of RPR level did not change over time. Public health campaigns were not associated with a significant shorter time from onset of symptoms to treatment. Alternative strategies such as more frequent testing of MSM should be promoted to control the syphilis epidemic in Australia.

Chow and Mackauer (1984) recently reported on inter- and intraspecific larval competition between Aphidius smithi Sharma & Subba Rao and Praon pequodorum Viereck (Hymenoptera: Aphidiidae), when both were parasitizing the pea aphid, Acyrthosiphon pisum (Harris) (Homoptera: Aphididae). In interspecific competition, a 1st-instar Praon larva usually eliminated, by physical combat, an Aphidius larva that was up to 48 h older. However, circumstantial evidence suggested that once an Aphidius larva had reached an advanced stage of the final (4th) instar, it was able to complete development and pupate, even in the presence of a younger Praon competitor.

Superparasitism and multiple parasitism of the pea aphid, Acyrthosiphon pisum (Harris), by the solitary hymenopterous parasites Aphidius smithi Sharma & Subba Rao and Praon pequodorum Viereck were studied in the laboratory. In intraspecific competition, an older larva usually eliminated a younger one; exceptions to this rule depended on the relative age difference and developmental stage of the competitors. In interspecific competition, P. pequodorum was intrinsically superior to A. smithi, regardless of the latter's age. The stage of host parasitized and the number of competing larvae had no significant effect on the outcome of the contest. A. smithi females discriminated against aphids previously parasitized by a conspecific female or by P. pequodorum, the degree of oviposition restraint increasing with the time between ovipositions. P. pequodorum females attacked aphids already parasitized by A. smithi, regardless of the age of the Aphidius larva, but avoided oviposition when the aphid contained a Praon larva or embryo. The rate of embryonic development is shown as a major factor in contest-type competition between first-stage larvae.

AlGaN/GaN high electron mobility transistors (HEMTs) with a polarized Polyvinylidene difluoride (PVDF) film coated on the gate area exhibited significant changes in channel conductance upon exposure to different ambient pressures. The PVDF thin film was deposited on the gate region with an inkjet plotter. Next, the PDVF film was polarized with an electrode located 2 mm above the PVDF film at a bias voltage of 10 kV and 70 °C. Variations in ambient pressure induced changes in the charge in the polarized PVDF, leading to a change of surface charges on the gate region of the HEMT. Changes in the gate charge were amplified through the modulation of the drain current in the HEMT. By reversing the polarity of the polarized PVDF film, the drain current dependence on the pressure could be reversed. Our results indicate that HEMTs have potential for use as pressure sensors.

Low resistance ohmic contacts are difficult to form to p-type GaN and AlGaN due to the unavailability of growth methods for highly p-doped GaN and AlGaN. A p-type carbon-doped GaAs regrowth on p-GaN prior to ohmic metallization has been shown in previous work to improve contact resistance to p-GaN [13]. Applying the regrowth method to the p-base regions of npn structured bipolar transistors, AlGaN/GaN heterojunction bipolar transistors and GaN bipolar junction transistors have been demonstrated. GaN/AlGaN epilayers were grown with a molecular beam epitaxy system. Highly carbon-doped p-GaAs (1020 cm−3) was regrown on the devices (∼500 Å) in the base contact region by metal organic chemical vapor deposition after emitter mesa etching. Emitter and base mesa structures were formed by Inductively Coupled Plasma etching under low damage conditions with a Cl2/Ar chemistry. SiO2 was used for emitter sidewall formation to reduce leakage current to the emitter, as well as for a mask for GaAs base regrowth. Very high current densities were obtained for common base operation in both device types. The devices were operable at 250 °C.

Gallium nitride wafer epitaxy on large diameter substrates is critical for the future fabrication of large area UV linear or 2D imaging arrays, as well as for the economical production of other GaN-based devices. Typical group III-nitride deposition is now performed on 2-inch diameter or smaller sapphire substrates. Reported here are visible blind, UV GaN p-i-n photodetectors which have been fabricated on 3-inch diameter (0001) sapphire substrates by RF atomic nitrogen plasma MBE. The uniformity across the wafer of spectral responsivity and shunt resistance (R0) for the p-i-n photodetectors has been characterized. Spectral responsivity and 1/f noise as a function of temperature exceeding 250°C will be presented for the GaN p-i-n photodetectors. Spectral response with >0.17 A/W at peak wavelength and having 4-6 orders of magnitude visible rejection has been achieved. 1/f noise typically less than 10−14 A/Hz1/2 at room temperature also has been achieved with GaN p-i-n photodiodes. The results have been correlated with proposed models for dark current and 1/f noise in GaN diodes.

Gallium nitride wafer epitaxy on large diameter substrates is critical for the future fabrication of large area UV linear or 2D imaging arrays, as well as for the economical production of other GaN-based devices. Typical group III-nitride deposition is now performed on 2-inch diameter or smaller sapphire substrates. Reported here are visible blind, UV GaN p-in photodetectors which have been fabricated on 3-inch diameter (0001) sapphire substrates by RF atomic nitrogen plasma MBE. The uniformity across the wafer of spectral responsivity and shunt resistance (R0) for the p-i-n photodetectors has been characterized. Spectral responsivity and 1/f noise as a function of temperature exceeding 250°C will be presented for the GaN p-i-n photodetectors. Spectral response with >0.17 A/W at peak wavelength and having 4-6 orders of magnitude visible rejection has been achieved. 1/f noise typically less than 10-14 A/Hz1/2 at room temperature also has been achieved with GaN p-i-n photodiodes. The results have been correlated with proposed models for dark current and 1/f noise in GaN diodes.

A GaN/AlGaN heterojunction bipolar transistor has been fabricated using Cl2/Ar dry etching for mesa formation. As the hole concentration increases due to more efficient ionization of the Mg acceptors at elevated temperatures (> 250°C), the device shows improved gain. Future efforts should focus on methods for reducing base resistance, which are briefly summarized.

Rapid Thermal Annealing (RTA) is indispensable for the formation of ultra-shallow source/drain junctions. To improve the annealing conditions, a fundamental understanding of the influences on the diffusion/activation process is necessary. Ion implantations of 1 keV boron at a dose of Φ≈1 I.1015 cm-2 are annealed in a SHS2800E RTP-system under controlled concentrations of oxygen in nitrogen ambient (0-1 ppm up to 1%). Concentration-depth profiles, measured by Secondary Ion Mass Spectroscopy (SIMS), are simulated within the framework of the kickout model involving diffusion enhancement via supersaturation of silicon self-interstitials. The validity of this interpretation is supported by the simulated results which are in good agreement with expenimental data. After RTA for 10 s at 1050°C the junctions are varying within a range of 800Å to 1400Ådepending on the annealing ambient. The results of the simulation yield finite values of self-interstitial supersaturation as a function of the oxygen concentration.

Low dielectric constant insulators offer the potential of improved interconnection delay and conductor packing density in advanced ICs, both with current metallization schemes and with future technologies such as copper. While polymer materials are very promising in such applications, significant issues must be addressed before oxide-based materials are replaced in mainstream applications. This invited paper reviews the directions of our program, which has emphasized the use of vapor deposited polymers compatible with uniform deposition over large diameter wafers and copper metallization. Therefore, emphasis is placed on polymer material characteristics compatible with inlaid metal (ie. Dual Damascene) patterning.

KNbO3 possesses high nonlinear optical coefficients making it a promising material for frequency conversion of infrared light into the visible wavelength range using integrated optical devices. While epitaxial thin films of KNbO3 have previously been grown using ion beam sputtering, defects (i.e. grain boundaries, domains, surface roughness) in these films resulted in high optical losses and no measurable in-plane birefringence. Previous films were grown on MgO substrates, which have a >4% lattice mismatch with KNbO3. In the work reported here, we have grown films on MgO, MgA12O4, NdGaO3, and KTaO3 to investigate the role of lattice mismatch on the resulting film quality. Films have also been grown with and without oxygen ion assistance. The orientations, morphologies, and defects in the films were examined using x-ray diffraction and AFM to determine their relationships to the growth conditions and substrate lattice mismatch.