Impacts of hurricanes and disease on Diadema antillarum in shallow water reef and mangrove locations in St John, USVI.

The 1983-1984 mortality event of the long-spined sea urchin Diadema antillarum reduced their population by up to 99% and was accompanied by a phase shift from coral dominated to algal dominated reefs in the Caribbean. Modest rebounds of D. antillarum populations in the Caribbean have been noted, and here we document the impacts of two major hurricanes (2017, Irma and Maria) and the 2022 disease outbreak on populations of D. antillarum found by targeted surveys in the urchin zone at nine fringing reef and three mangrove sites on St. John, USVI. D. antillarum populations at the reef sites had declined by 66% five months after the hurricanes but showed significant recovery just one year later. The impact of recent disease on these populations was much more profound, with all reef populations exhibiting a significant decline (96.4% overall). Fifteen months after the disease was first noted, D. antillarum at reef sites exhibited a modest yet significant recovery (15% pre-disease density). D. antillarum populations in mangrove sites were impacted by the hurricanes but exhibited much higher density than reef sites after the disease outbreak, suggesting that at D. antillarum in some locations may be less vulnerable to disease.

Tick Species Composition, Collection Rates, and Phenology Provide Insights into Tick-Borne Disease Ecology in Virginia.

To better understand tick ecology in Virginia and the increasing Lyme disease incidence in western Virginia, a comparative phenological study was conducted in which monthly collections were performed at twelve sampling locations in southwestern Virginia (high Lyme disease incidence) and 18 equivalent sampling locations in southeastern Virginia (low Lyme disease incidence) for one year. In western Virginia, we also explored the effect of elevation on collection rates of Ixodes scapularis Say (Acari: Ixodidae) and Amblyomma americanum (L.) (Acari: Ixodidae). In total, 35,438 ticks were collected (33,106 A. americanum; 2,052 I. scapularis; 134 Ixodes affinis Neumann [Acari: Ixodidae]; 84 Dermacentor variabilis [Say] [Acari: Ixodidae]; 49 Dermacentor albipictus [Packard] [Acari: Ixodidae]; 10 Haemaphysalis leporispalustris [Packard] [Acari: Ixodidae]; 2 Ixodes brunneus Koch [Acari: Ixodidae]; 1 Haemaphysalis longicornis Neumann [Acari: Ixodidae]). Within southwestern Virginia, Ixodes scapularis collection rates were not influenced by elevation, unlike A. americanum which were collected more frequently at lower elevations (e.g., below 500 m). Notably, I. scapularis larvae and nymphs were commonly collected in southwestern Virginia (indicating that they were questing on or above the leaf litter) but not in southeastern Virginia. Questing on or above the leaf litter is primarily associated with northern populations of I. scapularis. These findings may support the hypothesis that I. scapularis from the northeastern United States are migrating into western Virginia and contributing to the higher incidence of Lyme disease in this region. This comparative phenological study underscores the value of these types of studies and the need for additional research to further understand the rapidly changing tick-borne disease dynamics in Virginia.

Repeated detection of microbes in beverages dispensed from soda fountain machines and the effect of flushing on microbial density.

Few studies have examined patterns of microbial contamination in soda fountain beverages. In this study, patterns of microbial contamination in beverages dispensed from soda fountain machines (SFMs) sampled in June 2009 and then again 13 months later were compared. Over 70% of beverages contained microbes in both years, suggesting that contamination of beverages dispensed from SFMs can continue for long periods of time. In addition, the impact of disinfecting the dispensing nozzles and plastic tubing of SFMs, as well as the impact of machine use on microbial contamination was assessed. Managers from 26 establishments (fast-food and convenience stores) were interviewed about their SFM disinfecting practices and no correlation was found between the self-reported disinfecting practices and levels of microbial contamination in beverages dispensed from SFMs. Furthermore, in a direct study of two SFMs with an established disinfecting regimen, CFU/mL in beverages increased significantly immediately after disinfecting of plastic tubing yet returned to pre-disinfecting concentrations within 11 days. These results suggest that disinfecting may disturb microbial communities, resulting in increased planktonic microbes, but not the ultimate removal of communities themselves. Additionally, samples of a sugar and a diet soda were collected from 15 different SFMs before and after dispensing of ~0.95 L (the approximate size of a large beverage cup). Samples collected before dispensing this volume had significantly higher microbial counts than those collected after, suggesting that planktonic microbes in the beverage lines had been reduced by flushing. As there are currently no regulations regarding the disinfecting of SFM tubing or periodic inspections of beverages dispensed from SFMs, it would be valuable for consumers to encourage increased surveillance of SFMs, and to dispense some beverage before filling their cups.

The role of corticosterone in supporting migratory lipogenesis in the dark-eyed Junco, Junco hyemalis: a model for central and peripheral regulation.

The functional role of corticosterone (CORT) in regulating migratory hyperphagia and lipogenesis was investigated in an annual migrant, the dark-eyed junco (Junco hyemalis). Intraperitoneal injections of either dexamethasone (9 microg DXM/500 microL of 5% EtOH in saline, n=10) to inhibit an increase in baseline CORT or saline (5% EtOH, n=9) were given every 48 h for 15 d after transfer from short (10.5L:13.5D) to long (15.5L:8.5D) days. Food intake, body mass, furcular fat deposition scores, and nocturnal migratory activity were recorded for 29 d after photostimulation. Both groups showed the same increase in daily food intake over the study period (DXM=52%, control=41%). Controls began to increase baseline CORT and mass about 2 wk after photostimulation. DXM-treated birds maintained low CORT and did not increase mass or CORT until injections ceased, at which time they gained mass at the same rate shown earlier by controls. DXM-treated birds did not show greater levels of migratory activity despite experiencing an increase in energy intake during the CORT-inhibited period. Collectively, the results support the migration modulation hypothesis, illustrating how an increase in baseline CORT is needed to support the development of migratory condition. We address the apparent conflict with earlier studies on CORT and migratory food intake and propose a model in which migratory hyperphagia is supported by changes in centrally regulated responses to CORT that can occur even if CORT remains low and lipogenesis is regulated predominantly by peripheral mechanisms that require an increase in baseline CORT.