Biomedical subjects

G M Jones

Publications and source records attributed to G M Jones.

184 records · Page 11Linked to original sources

PubMedDate not supplied

Terminology associated with vitrification and other cryopreservation procedures for oocytes and embryos.

Over the past 30 years many cryopreservation procedures have been applied to oocytes, embryos, sperm, ovarian and testicular tissue. Over this time many, often specialized, terms have been developed for all aspects of these procedures. This can make it difficult for readers who are not familiar with the terminology or protocols to compare and evaluate different procedures. This paper describes the main cryopreservation procedures, the terminology associated with them, and briefly explains the underlying physical, chemical and biological processes. The aim is to help readers understand and interpret other papers on slow cooling, rapid cooling, ultrarapid cooling and vitrification.

Cryopreservation↗

PubMedDate not supplied

Subjective detection of vertical acceleration: a velocity-dependent response?

Human subjective thresholds and directional sensitivity were investigated as a function of vertical linear acceleration with head erect. A hyperbolic (r=0.94) relation emerged between threshold latency and acceleration magnitude (range 0.005 to 0.06 g). This implies that detection was determined by attainment of a given velocity (21.6+/-2.65 cm/sec) rather than the acceleration magnitude per se. Re-analysis of previous data from horizontal accelerations conducted with head erect and supine revealed similar hyperbolic relations (r=0.98 in both cases) with velocity constants of 22.6+/-1.28 and 32.4+1.96 cm/sec respectively. From these findings it is inferred that with head erect (i.e. normal attitude re gravity) the thresholds to predominantly utricular (horizontal accel.) and saccular (vert. accel.) stimulation were similar (P greater than 0.7). However, with head "supine" the saccular threshold was increased to approx. 1.5Xnormal (P less than 0.001). The results also confirmed a previously reported difficulty in the subjective detection of the direction of vertical movement.

Acceleration↗

PubMedDate not supplied

Comparison of human subjective and oculomotor responses to sinusoidal vertical linear acceleration.

Human subjects were vertically oscillated in the dark over a frequency range of 1-0.02 HZ at peak-to-peak acceleration amplitudes of 0.2-0.6 g, using both a vertical movement simulator and real flight. Subjective tracking of the movement was unreliable and showed no systematic dependence of phase upon frequency. In contrast, reflex oculomotor response, although weak, clearly demonstrated progressive and substantial phase lag with increasing frequency. The similarity of this characteristic to that previously obtained from brainstem neural responses in cat suggests the oculomotor response was primarily of a vestibular origin. The in-flight studies demonstrated that head movement in a changing linear accelerative field, especially at 0.1 Ha, is highly provocative of motion sickness despite subthreshold angular movement of the aircraft.

Acceleration↗

PubMedDate not supplied

Working together in Peru--language needn't be a problem!

International, co-operative links between dental schools are an increasingly common occurrence, especially in relation to elective visits for under-graduates. However, in this feature for FDI World Norman Whitehouse and Gillian Jones from the Cardiff Dental School in Wales, UK, describe how they came to meet and assist Teresa Rios Caro in Peru, in rather different circumstances, and how language need not be a barrier when goodwill prevails.

Communication Barriers↗