Fossil black smoker yields oxygen isotopic composition of Neoproterozoic seawater.

The evolution of the seawater oxygen isotopic composition (δ18O) through geological time remains controversial. Yet, the past δ18Oseawater is key to assess past seawater temperatures, providing insights into past climate change and life evolution. Here we provide a new and unprecedentedly precise δ18O value of -1.33 ± 0.98‰ for the Neoproterozoic bottom seawater supporting a constant oxygen isotope composition through time. We demonstrate that the Aït Ahmane ultramafic unit of the ca. 760 Ma Bou Azzer ophiolite (Morocco) host a fossil black smoker-type hydrothermal system. In this system we analyzed an untapped archive for the ocean oxygen isotopic composition consisting in pure magnetite veins directly precipitated from a Neoproterozoic seawater-derived fluid. Our results suggest that, while δ18Oseawater and submarine hydrothermal processes were likely similar to present day, Neoproterozoic oceans were 15-30 °C warmer on the eve of the Sturtian glaciation and the major life diversification that followed.

Stimulation of bone healing with interferential therapy.

Methods of electrical stimulation of bone are reviewed for a comparison with the use of interference currents and for a consideration of the possible merits of various methods. A summary is given of results of treatment of 38 patients with delayed or non-union and predisposition to non-union, and the technique used with Interferential Therapy is described in detail. Results are also given of a study of the effects of stimulation on 11 patients with acute fractures of the tibial shaft, compared with 11 closely matched patients with similar acute fractures who did not receive Interferential Therapy. The advantages of surgically non-invasive techniques are emphasised and recommendations are made for the use of interference currents prophylactically in specific cases.

Inferential therapy to promote union of mandibular fractures.

Non-union of mandibular fractures is uncommon, but when it does occur it requires protracted treatment including further surgery. Nine patients with factors known to predispose to non-union out of 150 consecutive mandibular fractures received interferential therapy (I.T.) during the fixation period; all fractures united satisfactorily. In a retrospective study of 150 consecutive mandibular fractures previously treated by the same surgeons without I.T., three fractures resulted in non-union requiring grafting. Thus the incidence of non-union was 0% when I.T. was used and 2% in the control group.

Interferential therapy.

Interferential Therapy is a "new-comer" to the field of physical medicine, but it is gradually acquiring a particular identity. As the name implies, a current is generated within the tissues as a result of the interaction of two separate circuits. It can therefore be appreciated that four electrodes are required, two for each circuit. The two currents generated by the unit are medium frequency currents in the 4000 cycle per second range. One of these can be varied so that it is slightly out of phase with the other in such a way that a low frequency beat is generated where the two currents cross within the tissues, and this is equal to the difference between the two medium frequencies. The interferential current produced is an evenly alternating sinusoidal one, without polar effects (Diagram 1). Its frequency can be varied from 0 to 100 or 150, depending on the unit. It is evident that such a current can be made to scan the tissues more deeply, more accurately and more widely than the old sinusoidal current, depending on the way electrodes are placed, to determine where the low frequency current will be produced. Further, it has less superficial sensory effect, provided it is applied correctly. It is undoubtedly an effective therapy for controlling pain.

Why do physical treatments relieve pain?

Those engaged in the clinical rather than the experimental field of medicine are constantly striving to improve their methods of relieving pain, using chemotherapy, surgery or physical therapy according to their particular specialization. This is hardly surprising, since all hospital departments, wards and private clinics are filled with a large proportion of patients seeking, primarily, relief from pain.

Report on the results of treatment of pain with the sustained sinusoidal current on 100 patients during 1964 and 1965.

The first report on the use of the Sinusoidal current in the treatment of pain was given to the Physiotherapy Society of South Australia in February, 1964. Twenty-six patients were treated; they all had post-traumatic pain with well defined local tenderness and/or hypersensitivity, and, in the case of the amputees, some phantom pains and jactitations as well. This method of treatment was described in the Australian Journal of Physiotherapy, December, 1964.