Memory-encoding vibrations in a disconnecting air bubble

Many nonlinear processes, such as the propagation of waves over an ocean or the transmission of light pulses down an optical fibre1, are integrable in the sense that the dynamics has as many conserved quantities as there are independent variables. The result is a time evolution that retains a complete memory of the initial state. In contrast, the nonlinear dynamics near a finite-time singularity, in which physical quantities such as pressure or velocity diverge at a point in time, is believed to evolve towards a universal form, one independent of the initial state2. The break-up of a water drop in air3 or a viscous liquid inside an immiscible oil4,5 are processes that conform to this second scenario. These opposing scenarios collide in the nonlinearity produced by the formation of a finite-time singularity that is also integrable. We demonstrate here that the result is a novel dynamics with a dual character

Assessment of anti-sperm antibodies in couples after testicular sperm extraction

Purpose: Testicular spermatozoa can be retrieved successfully by the testicular sperm extraction (TESE) procedure and used for intracytoplasmic sperm injection. Disruption in the blood-testis barrier can lead to the production of antisperm antibodies (ASA). The aim of this prospective study was to investigate the frequency of ASA formation in couples after TESE procedure. Methods: Thirty-seven couples were included in the study at the Urology Clinic of the Dr. Zekai Tahir Burak Women’s Health Training and Research Hospital. History, physical examination, spermiogram, and endocrine profiles were obtained for all male patients. All the male patients in this study had been diagnosed with nonobstructive azoospermia (NOA) and underwent microdissection TESE. Secondary and tertiary cases were also included in the study. Serum samples were obtained from all 74 patients before TESE, and at three and 12 months after TESE. Serum ASA levels were determined. ANOVA was performed for statistical analysis for serum Follicle-Stimulating Hormone (FSH), testosterone and testicular volume. P < 0.05 was considered significant. Results: There were no differences in the testicular volumes, serum FSH and testosterone levels before and after TESE. None of the patients or their partners developed significant levels of ASA as a result of the TESE procedure. Conclusion: TESE procedure does not cause ASA production in either males or their female partners

The entrainment of air by water jet impinging on a free surface

10.1007/s00348-005-0965-9Experiments in Fluids393496-504EXFL

Characterization of the interaction of two oscillating bubbles near a thin elastic membrane

10.1007/s00348-012-1389-yExperiments in Fluids5361723-1735EXFL