RESUMO
The songs of seven grasshopper species of subfamily Gomphocerinae from Russia, Ukraine, Georgia, and Kazakhstan were studied. We analysed not only the sound, but also the stridulatory movements of the hind legs to more entirely describe the songs. In Mesasippuskozhevnikovi, Chorthippusmacrocerus, and C.hammarstroemi, the legs are moved in a relatively simple pattern; four other species, Myrmeleotettixpalpalis, Stenobothrusnewskii, C.pullus, and Megaulacobothrusaethalinus demonstrate more complex leg movements. In six of the seven species studied, the courtship songs contain more sound elements than the calling songs. The highest number of courtship sound elements was found in M.palpalis and M.aethalinus. The different parts of a remarkably long stridulatory file in M.aethalinus are thought to participate in the production of different sound elements. The songs in S.newskii are shown for the first time. This species produces sound not only by common stridulation but also by wing beats. A relationship of S.newskii to some other species of the genus Stenobothrus, which are able to crepitate, is discussed. We also analyse the frequency spectra of the songs. A maximum energy of the song power spectra in six species studied lies in ultrasound range (higher than 20 kHz). In only M.aethalinus, the main peaks in the song power spectra lie lower than 20 kHz. The courtship behaviour in M.palpalis, C.macrocerus, and C.hammarstroemi was shown to include conspicuous visual display (movements of antennae, palps and the whole body).
RESUMO
PURPOSE: The prevalence of dry eye disease (DED) is rising among visual display terminal (VDT) users, a trend that correlates with the growing use of digital devices. The prevalence of VDT-associated DED is reported based on dry eye questionnaires; however, VDT's impact on tear film parameters is less understood. METHODS: A review of published literature on both the alterations in tear film observed in VDT users and the impact of various interventions on their tear film. RESULTS: Most studies show reduction in tear stability as well as reduction in the blink rate. The role of lacrimal gland hypofunction in visual display terminal (VDT) users is a subject of ongoing debate. Schirmer test values typically exceed the 10 mm threshold, suggesting normal tear production, and tear osmolarity remains within normal ranges but VDT users consistently present with lower Schirmer values compared to non-VDT users. The effects on Meibomian glands and mucin levels need more research as the numbers studied are small. Very few studies have analysed mucin levels in VDT users with reports of normal or reduced values. Even asymptomatic users can have tear film instability; hence, the diagnostic criteria need to be formulated and validated. Different interventions such as neurostimulation, blink improving apps, eyelid warming devices, moist goggles, and lubricants have been explored in VDT users but without a control arm and in asymptomatic VDT users in most studies. CONCLUSION: The alterations have been observed on aqueous, lipid and mucin components of the tear film, although the extent of the impact is variable across studies. There is urgent need of well-designed studies for studying the tear film changes and management options for the upcoming lifestyle epidemic in VDT users.