Belowground insect herbivory induces systemic volatile emissions that strengthen neighbouring plant resistance aboveground.

Plants transmit ecologically relevant messages to neighbouring plants through chemical cues. For instance, insect herbivory triggers the production of herbivore-induced plant volatiles (HIPVs), which can enhance neighbouring plant defences. HIPVs are emitted from directly damaged plant tissues and from systemic, nondamaged tissues. Although volatile-mediated interplant interactions have been observed both above- and belowground, it remains unknown whether belowground herbivory induces systemic HIPVs aboveground that influence neighbouring plants. To explore how belowground herbivory affects interplant interactions aboveground, we characterised systemic HIPVs from squash induced by belowground striped cucumber beetle (Acalymma vittatum) larval herbivory. We exposed squash 'receiver plants' to systemic HIPVs or volatiles from nondamaged plants. We then measured herbivore resistance by challenging 'receiver plants' with aboveground-feeding herbivores: adult beetles (A. vittatum) or squash bugs (Anasa tristis). We discovered belowground-damaged plants emitted more (E)-ß-ocimene, a key volatile from the systemic HIPV blend, than nondamaged controls, and that exposure to systemic HIPVs enhanced neighbouring plant resistance to aboveground squash bugs, but not adult beetles. Further investigations into the mechanism of interplant interaction revealed ß-ocimene alone can elicit plant resistance against squash bugs. Overall, our findings reveal a novel form of volatile-mediated interactions between plants spanning across aboveground-belowground plant systems.

Tip link loss and recovery on chick short hair cells following intense exposure to sound.

Stereocilia tip links on chick short hair cells (SHCs) were counted in the 'patch' lesion produced by acoustic overstimulation. Tip links were also counted on tall hair cells (THCs) immediately superior to the lesion. Eight groups were studied with three exposed to intense sound for differing durations. Three other groups were allowed to recover from the longest exposure for different time periods. Tip link counts from non-exposed control hair cells came from two other groups. Chicks exposed for 4, 24 or 48 h to a 120-dB SPL 0.9-kHz pure tone showed SHC tip link loss of 30.3, 40.6, and 35.5%, respectively. Chicks exposed for 48 h were allowed to recover for 24, 96 or 288 h, and showed systematic tip link recovery to control levels. Tip link loss and recovery in THCs adjacent to the patch lesion were identical to that seen in SHCs. After 288 h of recovery, surviving SHCs were distinguished from newly regenerated SHCs in the patch lesion. A comparison of tip link presence in the surviving (74%) and regenerated (84%) SHCs revealed a significant difference. These results suggest that the process of tip link destruction and recovery following acoustic overstimulation is the same for THCs and SHCs. This observation is surprising based on differences in the degree of acoustic injury to THC and SHC regions of the papillae, and the difference between THC and SHC sensory hair bundle stimulation.

Preoperative sonographic and clinical characteristics as predictors of ovarian torsion.

OBJECTIVE: The purpose of this study was to determine the most closely associated sonographic and clinical characteristics of ovarian torsion. METHODS: The medical records and sonographic studies of 39 patients with pathologically proven ovarian torsion diagnosed at our institution from July 1, 2000, through December 31, 2005, were retrospectively reviewed. The volumes of the affected ovaries and ovary/mass complexes were compared with an age-appropriate standard. Statistical significance of the data was assessed by a likelihood ratio chi(2) analysis. RESULTS: All patients (100%) had a chief symptom of abdominal pain. Thirty-three (85%) reported vomiting; 22 (56%) had leukocytosis; and 7 (18%) had a documented elevated temperature. All affected ovaries and ovary/mass complexes were enlarged. Twenty-one (54%) had arterial flow on Doppler interrogation, and 18 (46%) had no arterial flow. Thirteen (33%) had venous flow, and 26 (67%) had no venous flow. Differences in the arterial and venous flow patterns between the premenarchal and reproductive age groups were not statistically significant. CONCLUSIONS: Abdominal pain, vomiting, ovarian enlargement, and absence of ovarian venous Doppler flow are the most frequently shown clinical and sonographic indicators of ovarian torsion. However, ovarian enlargement, even in the presence of arterial and venous Doppler flow, is the most commonly associated sonographic finding. Suspicion of ovarian torsion should be high in the setting of clinical symptoms and ovarian enlargement regardless of the presence or absence of an ovarian Doppler signal.