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The interaction between planets and stellar winds can lead to atmospheric loss and is, thus, important for the evolution of planetary atmospheres 1 . The planets in our Solar System typically interact with the solar wind, whose velocity is at a large angle to the embedded stellar magnetic field. For planets without an intrinsic magnetic field, this interaction creates an induced magnetosphere and a bow shock in front of the planet 2 . However, when the angle between the solar wind velocity and the solar wind magnetic field (cone angle) is small, the interaction is very different 3 . Here we show that when the cone angle is small at Mars, the induced magnetosphere degenerates. There is no shock on the dayside, only weak flank shocks. A cross-flow plume appears and the ambipolar field drives planetary ions upstream. Hybrid simulations with a 4° cone angle show agreement with observations by the Mars Atmosphere and Volatile Evolution mission 4 and Mars Express 5 . Degenerate, induced magnetospheres are complex and not yet explored objects. It remains to be studied what the secondary effects are on processes like atmospheric loss through ion escape., (© 2024. The Author(s).)

We present initial analysis and conclusions from plasma observations made during the reported "Mars plume event" of March - April 2012. During this period, multiple independent amateur observers detected a localized, high-altitude "plume" over the Martian dawn terminator [Sanchez-Lavega et al., Nature, 2015, doi:10.1038/nature14162], the cause of which remains to be explained. The estimated brightness of the plume exceeds that expected for auroral emissions, and its projected altitude greatly exceeds that at which clouds are expected to form. We report on in-situ measurements of ionospheric plasma density and solar wind parameters throughout this interval made by Mars Express, obtained over the same surface region, but at the opposing terminator. Measurements in the ionosphere at the corresponding location frequently show a disturbed structure, though this is not atypical for such regions with intense crustal magnetic fields. We tentatively conclude that the formation and/or transport of this plume to the altitudes where it was observed could be due in part to the result of a large interplanetary coronal mass ejection (ICME) encountering the Martian system. Interestingly, we note that the only similar plume detection in May 1997 may also have been associated with a large ICME impact at Mars.

In open or video-assisted thoracic surgery, injury to one to four intercostal sensory nerves is a well-recognized complication. This nerve damage is a well-defined cause for chronic postoperative pain. In this discussion, the motor innervation of the rectus abdominis muscle with the T7 to T12 intercostal nerves has been neglected. Paralysis of rectus abdominis might pose significant burden on patients, delay recovery, and thus warrants exploration.

Carrying a heavy backpack exerts compression on shoulders, with the potential to cause brachial plexopathy. We evaluated the incidence and predisposing factors of compression plexopathy of the shoulder region in 152,095 military conscripts, hypothesizing that a low body mass index and poor physical fitness predispose to the plexus lesion. Reports of conscripts with neural lesions of the upper arm associated with load carriage were reviewed retrospectively for details associated with the condition onset, symptoms, signs, nerve conduction studies, and electromyographic examinations. Height, weight, and physical fitness scores were obtained from their military training data. The incidence of neural compression after shoulder load carriage in Finnish soldiers was 53.7 (95% confidence interval, 39.5-67.8) per 100,000 conscripts per year. The long thoracic nerve was affected in 19, the axillary nerve in 13, the suprascapular nerve in seven, and the musculocutaneous nerve in six patients. Four patients (7%) had hereditary neuropathy with susceptibility to pressure palsies (HNPP). Symptoms were induced by lighter loads in patients with HNPP. Vulnerability to brachial plexopathy was not predictable from body structure or physical fitness level. To prevent these lesions, awareness of the condition and its symptoms should be increased and backpack designs should be improved.

Objective: To characterise the activation of the contra- and ipsilateral primary somatosensory cortex (SI) after tactile stimulation of the face., Methods: Trigeminal somatosensory evoked magnetic fields (TSEFs) were recorded after tactile stimulation of the lower lip, cheek, chin and forehead in 11 healthy subjects. The responses were determined visually from the waveforms and modelled with equivalent current dipoles (ECDs)., Results: Contralateral SI responses were evoked in all subjects after lip stimulation, and in 91% and 64% after right and left cheek, 73% and 82% after chin and 64% and 27% after forehead stimulation. The responses usually showed an early double-peak wave pattern, the underlying sources localising to the SI. In addition, altogether 37 ipsilateral SI responses were evoked in eight subjects. Fourteen of these responses were amenable to ECD modelling and localised to ipsilateral SI., Conclusions: Tactile stimulation of the lip area reliably activates the contralateral SI in normal subjects, but the success rate for other trigeminal areas is lower. Ipsilateral responses can be present after stimulation of any of the trigeminal branches in normal subjects., Significance: Recording of TSEFs after tactile stimulation of particularly the lip area provides a non-invasive technique to study the function of the trigeminal nerve.