Jupiter's Low-Altitude Auroral Zones: Fields, Particles, Plasma Waves, and Density Depletions

The Juno spacecraft's polar orbits have enabled direct sampling of Jupiter's low-altitude auroral field lines. While various data sets have identified unique features over Jupiter's main aurora, they are yet to be analyzed altogether to determine how they can be reconciled and fit into the bigger picture of Jupiter's auroral generation mechanisms. Jupiter's main aurora has been classified into distinct "zones", based on repeatable signatures found in energetic electron and proton spectra. We combine fields, particles, and plasma wave data sets to analyze Zone-I and Zone-II, which are suggested to carry upward and downward field-aligned currents, respectively. We find Zone-I to have well-defined boundaries across all data sets. H⁺ and/or H₃ ⁺ cyclotron waves are commonly observed in Zone-I in the presence of energetic upward H⁺ beams and downward energetic electron beams. Zone-II, on the other hand, does not have a clear poleward boundary with the polar cap, and its signatures are more sporadic. Large-amplitude solitary waves, which are reminiscent of those ubiquitous in Earth's downward current region, are a key feature of Zone-II. Alfvénic fluctuations are most prominent in the diffuse aurora and are repeatedly found to diminish in Zone-I and Zone-II, likely due to dissipation, at higher altitudes, to energize auroral electrons. Finally, we identify significant electron density depletions, by up to 2 orders of magnitude, in Zone-I, and discuss their important implications for the development of parallel potentials, Alfvénic dissipation, and radio wave generation.

In Search of Subsurface Oceans Within the Uranian Moons

The Galileo mission to Jupiter discovered magnetic signatures associated with hidden subsurface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate from electrically conductive layers within the moons and are driven by Jupiter's strong time-varying magnetic field. The ice giants and their moons are also ideal laboratories for magnetic induction studies. Both Uranus and Neptune have a strongly tilted magnetic axis with respect to their spin axis, creating a dynamic and strongly variable magnetic field environment at the orbits of their major moons. Although Voyager 2 visited the ice giants in the 1980s, it did not pass close enough to any of the moons to detect magnetic induction signatures. However, Voyager 2 revealed that some of these moons exhibit surface features that hint at recent geologically activity, possibly associated with subsurface oceans. Future missions to the ice giants may therefore be capable of discovering subsurface oceans, thereby adding to the family of known "ocean worlds" in our Solar System. Here, we assess magnetic induction as a technique for investigating subsurface oceans within the major moons of Uranus. Furthermore, we establish the ability to distinguish induction responses created by different interior characteristics that tie into the induction response: ocean thickness, conductivity and depth, and ionospheric conductance. The results reported here demonstrate the possibility of single-pass ocean detection and constrained characterization within the moons of Miranda, Ariel, and Umbriel, and provide guidance for magnetometer selection and trajectory design for future missions to Uranus.

In Search of Subsurface Oceans Within the Uranian Moons

The Galileo mission to Jupiter discovered magnetic signatures associated with hidden subsurface oceans at the moons Europa and Callisto using the phenomenon of magnetic induction. These induced magnetic fields originate from electrically conductive layers within the moons and are driven by Jupiter's strong time-varying magnetic field. The ice giants and their moons are also ideal laboratories for magnetic induction studies. Both Uranus and Neptune have a strongly tilted magnetic axis with respect to their spin axis, creating a dynamic and strongly variable magnetic field environment at the orbits of their major moons. Although Voyager 2 visited the ice giants in the 1980s, it did not pass close enough to any of the moons to detect magnetic induction signatures. However, Voyager 2 revealed that some of these moons exhibit surface features that hint at recent geologically activity, possibly associated with subsurface oceans. Future missions to the ice giants may therefore be capable of discovering subsurface oceans, thereby adding to the family of known "ocean worlds" in our Solar System. Here, we assess magnetic induction as a technique for investigating subsurface oceans within the major moons of Uranus. Furthermore, we establish the ability to distinguish induction responses created by different interior characteristics that tie into the induction response: ocean thickness, conductivity and depth, and ionospheric conductance. The results reported here demonstrate the possibility of single-pass ocean detection and constrained characterization within the moons of Miranda, Ariel, and Umbriel, and provide guidance for magnetometer selection and trajectory design for future missions to Uranus.

Ice giant system exploration in the 2020s: an introduction

The international planetary science community met in London in January 2020, united in the goal of realizing the first dedicated robotic mission to the distant ice giants, Uranus and Neptune, as the only major class of solar system planet yet to be comprehensively explored. Ice-giant-sized worlds appear to be a common outcome of the planet formation process, and pose unique and extreme tests to our understanding of exotic water-rich planetary interiors, dynamic and frigid atmospheres, complex magnetospheric configurations, geologically-rich icy satellites (both natural and captured), and delicate planetary rings. This article introduces a special issue on ice giant system exploration at the start of the 2020s. We review the scientific potential and existing mission design concepts for an ambitious international partnership for exploring Uranus and/or Neptune in the coming decades. This article is part of a discussion meeting issue 'Future exploration of ice giant systems'.

A review of the in situ probe designs from recent Ice Giant mission concept studies

For the Ice Giants, atmospheric entry probes provide critical measurements not attainable via remote observations. Including the 2013-2022 NASA Planetary Decadal Survey, there have been at least five comprehensive atmospheric probe engineering design studies performed in recent years by NASA and ESA. International science definition teams have assessed the science requirements, and each recommended similar measurements and payloads to meet science goals with current instrument technology. The probe system concept has matured and converged on general design parameters that indicate the probe would include a 1-meter class aeroshell and have a mass around 350 to 400-kg. Probe battery sizes vary, depending on the duration of a post-release coast phase, and assumptions about heaters and instrument power needs. The various mission concepts demonstrate the need for advanced power and thermal protection system development. The many completed studies show an Ice Giant mission with an in situ probe is feasible and would be welcomed by the international science community.

Development of HyBeacon® probes for the forensic detection of Panthera, rhinoceros, and pangolin species

The Illegal Wildlife Trade (IWT) represents a multi-billion dollar black-market industry whereby wild species are illegally taken from their natural environment and sold. A common question asked by wildlife forensic scientists pertains to species and/or genus identity, which currently requires multi-step processing. Our work details the development of three HyBeacon® probes, used for the presumptive detection of rhinoceros, pangolin and key target species in the Panthera genus. The approach can be performed in a single tube using melt curve analysis and provide rapid assessment of sample identity. Using synthetic DNA of representative species, early data suggest the approach is sensitive enough to achieve species identification with <10 cells. Future development and assay validation can allow the rapid screening of multiple seized items before confirmatory DNA sequencing.

Defining end user requirements for a field-based molecular detection system for wildlife forensic investigations

The increasing use of non-laboratory-based DNA and protein detection methods promise to provide rapid investigative intelligence and support sample prioritisation. Primarily developed for human forensic or medical applications, current systems may also show utility in the field of wildlife forensic science. However, it is currently unknown whether the requirements of the wildlife forensic community can be met by current non-laboratory based tools. Given the diverse array of stakeholders and sample types commonly encountered, it is necessary to first identify the needs of the community and then try and map their needs to current instrumentation. By using a market research style questionnaire, this study identified key requirements for a non-laboratory-based system following feedback from the wildlife forensic community. Data showed that there is strong support for field-based detection methods while highlighting concerns including contamination risks and reduced quality assurance associated with non-laboratory testing. Key species and applications were identified alongside hurdles to implementation and adoption. Broadly, the requirements align with many of the developmental drivers that have led to the rise of in-field portable detection instrumentation, specifically rapid detection within one hour, ease-of-use, and ≥95% accuracy. Several existing platforms exist that met some of the identified requirements but not all. With further collaboration between industry partners and the wildlife forensic community it is possible that new field-based systems can be developed and applied routinely.

Quasiperpendicular High Mach Number Shocks

Shock waves exist throughout the Universe and are fundamental to understanding the nature of collisionless plasmas. Reformation is a process, driven by microphysics, which typically occurs at high Mach number supercritical shocks. While ongoing studies have investigated this process extensively both theoretically and via simulations, their observations remain few and far between. In this Letter we present a study of very high Mach number shocks in a parameter space that has been poorly explored and we identify reformation using in situ magnetic field observations from the Cassini spacecraft at 10 AU. This has given us an insight into quasiperpendicular shocks across 2 orders of magnitude in Alfvén Mach number (M_{A}) which could potentially bridge the gap between modest terrestrial shocks and more exotic astrophysical shocks. For the first time, we show evidence for cyclic reformation controlled by specular ion reflection occurring at the predicted time scale of ~0.3τ_{c}, where τ_{c} is the ion gyroperiod. In addition, we experimentally reveal the relationship between reformation and M_{A} and focus on the magnetic structure of such shocks to further show that for the same M_{A}, a reforming shock exhibits stronger magnetic field amplification than a shock that is not reforming.

Asymmetries observed in Saturn's magnetopause geometry

For over 10 years, the Cassini spacecraft has patrolled Saturn's magnetosphere and observed its magnetopause boundary over a wide range of prevailing solar wind and interior plasma conditions. We now have data that enable us to resolve a significant dawn-dusk asymmetry and find that the magnetosphere extends farther from the planet on the dawnside of the planet by 7 ± 1%. In addition, an opposing dawn-dusk asymmetry in the suprathermal plasma pressure adjacent to the magnetopause has been observed. This probably acts to reduce the size asymmetry and may explain the discrepancy between the degree of asymmetry found here and a similar asymmetry found by Kivelson and Jia (2014) using MHD simulations. Finally, these observations sample a wide range of season, allowing the "intrinsic" polar flattening (14 ± 1%) caused by the magnetodisc to be separated from the seasonally induced north-south asymmetry in the magnetopause shape found theoretically (5 ± 1% when the planet's magnetic dipole is tilted away from the Sun by 10-17°).

Internally driven large-scale changes in the size of Saturn's magnetosphere

Saturn's magnetic field acts as an obstacle to solar wind flow, deflecting plasma around the planet and forming a cavity known as the magnetosphere. The magnetopause defines the boundary between the planetary and solar dominated regimes, and so is strongly influenced by the variable nature of pressure sources both outside and within. Following from Pilkington et al. (2014), crossings of the magnetopause are identified using 7 years of magnetic field and particle data from the Cassini spacecraft and providing unprecedented spatial coverage of the magnetopause boundary. These observations reveal a dynamical interaction where, in addition to the external influence of the solar wind dynamic pressure, internal drivers, and hot plasma dynamics in particular can take almost complete control of the system's dayside shape and size, essentially defying the solar wind conditions. The magnetopause can move by up to 10-15 planetary radii at constant solar wind dynamic pressure, corresponding to relatively "plasma-loaded" or "plasma-depleted" states, defined in terms of the internal suprathermal plasma pressure.

Mycobacteria distenct from Mycobacterium avium subsp. paratuberculosis isolated from the faeces of ruminants possess IS900-like sequences detectable IS900 polymerase chain reaction: implications for diagnosis

PCR targeting the 5' end of IS 900 has been considered specific for identification of Mycobacterium avium subsp. paratuberculosis and is frequently applied to confirm the presence of this organism in the diagnosis of Johne's disease. IS 900 PCR has also been applied to studies of the aetiology of Crohn's disease. Mycobacterium spp. isolated from the faeces of 3 clinically normal animals in 2 Australian states appeared not to be M. paratuberculosis but were positive by IS 900 PCR. The isolates were characterized using mycobactin dependency, biochemical tests, IS 900 and 16 S rRNA sequencing and restriction fragment length polymorphism (RFLP) using IS 900 as probe. DNA sequencing confirmed that the isolates had between 71% and 79% homology with M. paratuberculosis in the region of IS 900 amplified, were most closely related to Mycobacterium scrofulaceum, and confirmed the usefulness of restriction enzyme analysis of amplified product to identify the false positive results. RFLP analysis with Bst Ell detected three to five copies of the IS 900 -like element in the isolates. These were located in molecular weight fragments that were clearly different to IS 900 in previously characterized strains of M. paratuberculosis. It is likely that these isolates are environmental mycobacteria. Southern blotting with an internal probe is unlikely to provide differentiation of M. paratuberculosis from these organisms. We recommend the adoption of restriction endonuclease analysis of IS 900 PCR product as a routine precaution to prevent the reporting of false positive IS 900 PCR results.

Written Communication With Survivors of Sexual Abuse: Use of Letters in Therapy

1. Written therapeutic communication with clients can have a lasting impact by enhancing themes of a therapy session, commenting on strengths, and highlighting changes. 2. Therapeutic letters can be used to validate the sexual abuse survivor's experience, offer commendation, provide information, normalize day-to-day living, encourage reflection, and seek clarification. 3. The use of therapeutic letters is consistent with a family systems nursing approach to practice, in which the nurse focuses on strengths and resources, interactions, and reciprocity during contact with the patient.

Hepatic metastases: interstitial laser photocoagulation with real-time US monitoring and dynamic CT evaluation of treatment

Fifty-five liver metastases in 21 patients were treated with interstitial laser photocoagulation (ILP). Tumors were irradiated with a neodymium yttrium aluminum garnet laser via optical fibers passed through 19-gauge needles inserted under ultrasound (US) guidance. Heating of the tumor was evident at real-time US as an expanding and coalescing echogenic zone around the needle tips. After ILP, dynamic computed tomography (CT) showed laser-induced necrosis as a new area of nonenhancement. Necrosis of tumor volume was more than 50% in 82% (45 of 55) of the tumors, and 100% necrosis was achieved in 38% (21 of 55). Metastases smaller than 4 cm in diameter were treated more effectively and required fewer treatment sessions than did those larger than 4 cm. Complications were minor and included severe pain in four cases, persistent pain for up to 10 days in 11 cases, and asymptomatic subcapsular hematoma (four cases) and pleural effusion (six cases) seen with CT. ILP is safe and effective for liver tumor destruction, and US and CT are useful in different aspects of treatment monitoring.

The extensometer--use in spontaneously ventilating awake volunteers

The extensometer is a new device with potential in the field of respiratory pattern analysis. This paper describes the physical principles upon which the extensometer depends and also assesses its performance as a noninvasive respiratory monitor in respect of its ability to measure tidal volume and to determine obstructive breathing patterns in awake volunteers in the supine position over a limited time period. Further developments of the device are outlined and the current status of torso transducers in anaesthesia and intensive care are discussed.

Endoscopic transthoracic sympathectomy for idiopathic upper limb hyperhidrosis

A 5-year experience of 51 endoscopic transthoracic dorsal sympathectomies for idiopathic palmar hyperhidrosis in 26 patients is presented. Fifty-two percent complained of excessive sweating over their hands, 28% of axillary sweating and 20% over both areas, with a mean duration of 10 years. The second, third and fourth thoracic ganglia and their interconnecting fibres on the affected side were ablated using diathermy cautery. Over a mean follow up time of 26 months, this procedure was successful in curing or improving intractable sweating in 92%. However, axillary sweating was less well controlled than in the palms with 20% of patients describing residual wetness in the axilla. Compensatory sweating (75%) and gustatory sweating (48%) were the commonest side effects; despite this, most patients were satisfied with the functional and cosmetic outcome. Other complications included a temporary Horner's syndrome in one patient, a pneumothorax in the immediate post-operative period in another and a unilateral non-infective reactionary pleural effusion in a third. Two patients developed recurrence of palmar hyperhidrosis within 6 months of surgery. One has been successfully treated by re-operation on the affected side. All patients complained of mild to moderate interscapular chest pain which was easily controlled by non-steroidal anti-inflammatory agents, and resolved within 7-10 days post-operatively. The technique of endoscope transthoracic sympathectomy is effective, relatively simple to perform and usually requires only an overnight stay. It is recommended as the surgical treatment of choice for upper limb hyperhidrosis unresponsive to conservative measures.

Interstitial laser hyperthermia: a new approach for treating liver metastases

The palliative management of hepatic metastases remains unsatisfactory. There is a need for a simple non invasive technique which can stop or retard the rate of tumour growth. In principle, Interstitial Laser hyperthermia may fulfil such a role. In experimental studies, this technique produced precise in situ necrosis within solid organs which healed safely. In a pilot feasibility study, we treated ten patients with a total of 18 hepatic metastases on 31 occasions using a percutaneous approach to achieve an overall objective response rate of 44%. The treatment proved simple to perform, was well tolerated and produced radiological evidence of necrosis in small metastases (diameter less than or equal to 3 cm). However, further research is required before the technique can be regarded as established. Its future role in most cases will be to control the growth of discrete hepatic metastases unsuitable for resection. In instances where the extent of necrosis can be matched accurately to tumour volume, the potential for cure exists.

Interstitial laser hyperthermia

Experimental studies have shown that once the appropriate laser parameters are defined, interstitial laser hyperthermia (ILH) can produce well-defined, predictable tissue necrosis in solid viscera which heal safely with little functional or structural sequelae. Preliminary clinical studies have illustrated that ILH is simple to perform, is well tolerated producing radiological and histological evidence of necrosis in liver, pancreatic, and breast cancer. Its future role in most cases will be palliative, controlling local tumour growth. Where the extent of necrosis can be matched accurately to tumour volume, the prospect for cure exists. Further research is necessary before ILH can be regarded as an established treatment and, in particular, its influence on patient survival is worthy of further evaluation.

Role of interstitial therapy in the treatment of liver cancer

Conventional palliative management of inoperable focal hepatic tumours remains unsatisfactory. Interstitial techniques such as cryotherapy, alcohol injection, low power laser hyperthermia and interstitial radiotherapy offer alternative approaches. Cryotherapy is an effective and precise technique for inducing tumour necrosis. It can only be performed at laparotomy making it relatively invasive and retreatment impractical. Alcohol is cheap and can be injected percutaneously. However, inhomogeneous distribution produces imprecise and nonreproducible lesions. Low power laser hyperthermia produces precise and reproducible areas of necrosis that are roughly spherical in shape. At present, this technique is most effective for small tumours. Interstitial radiotherapy remains the least evaluated of all the interstitial techniques. Unlike cryotherapy and low power laser hyperthermia, the biological effect of ethanol injection and interstitial radiotherapy cannot be monitored in real time by ultrasound. With the exception of cryotherapy, all methods can be applied percutaneously with low morbidity and mortality. None of these techniques is established, but they may offer the prospect of cure in cases where all areas of tumour can be positively identified and fully treated. However, in most instances the intention is to control the growth of relatively small discrete volumes of tumour within the hepatic parenchyma.

Sigmoid invasion as a late complication of mucinous cystadenoma of the appendix. Report of a case

A cystic mass arising from the right iliac fossa was an incidental finding at laparotomy and was treated conservatively after a biopsy had shown no evidence of malignancy. Nine years later the patient presented with shock and colonic bleeding. A large cystic lesion arising from the vermiform appendix and invading the sigmoid colon was found and excised. Histologic examination indicated that the underlying lesion was an inflamed mucinous cystadenoma of the appendix. Frank invasion of viscera by such lesions has not previously been described. Complications of such lesions and their association with other colonic neoplasms are discussed.

Hypernephroma presenting as a lump in the breast

The breast is an unusual site for metastatic disease--generally, the breast lesion appears some time after diagnosis of the primary malignancy. An instance of renal cell carcinoma in a 69 year old woman, which presented primarily as a breast lump, is described. This is only the third such case that has been reported in the literature.

Detection of pS2 messenger RNA in gynecological cancers

Estrogen-inducible pS2 mRNA was previously detected in human cancer cell lines the growth of which was sensitive to estrogen. In the present study, the expression of the pS2 gene was analyzed in 111 gynecological carcinomas. The pS2 message was detected in greatest abundance in 6 primary carcinomas of the ovary (6 of 29), 4 of these being mucinous cystadenocarcinomas. A secondary carcinoma of the ovary, and another of the omentum (1 of 4), also contained detectable levels of pS2 mRNA. Weak pS2 mRNA signals were occasionally observed in endometrial (2 of 55) and cervical carcinomas (2 of 33) as well. There was a poor correlation between estrogen receptor and pS2 mRNA in ovarian carcinomas.

Long-term recurrence patterns following proximal gastric vagotomy

Two hundred and forty-two consecutive patients were prospectively followed up following elective proximal gastric vagotomy (PGV) for duodenal, pyloric or prepyloric ulceration. There was no operative mortality and no case of lesser curve necrosis. Five to 15 years follow-up have been completed. One hundred and eighty-three patients were assessable (80% of survivors) and 29 of 33 symptomatic patients attended for endoscopy. Fourteen recurrent ulcers had been diagnosed previously and six new recurrences were diagnosed, giving a total recurrence rate of 11%. Seven of these were transient/innocuous and 13 (7%) were chronic/malevolent recurrences. The majority (70%) of recurrences occurred in the first 5 years of follow-up and only one recurrence occurred later than 10 years' follow-up. More than half (56%) of the operations were performed utilizing Burge intra-operative testing and 44% without Burge testing. No difference in recurrence rates was apparent between these two groups. In seven patients with pyloric or prepyloric ulceration, three (43%) developed a chronic recurrence. PGV is a safe, surgical treatment for duodenal ulceration, offering acceptable recurrence rates and a very low mortality and low incidence of side-effects. The majority of recurrences occur early in the follow-up period. Burge intra-operative testing provides no clear reduction in recurrence rates. PGV should not be used for pyloric or prepyloric ulceration.