North Atlantic right whales (Eubalaena glacialis) ignore ships but respond to alerting stimuli

Author Posting. © Royal Society, 2004. This article is posted here by permission of Royal Society for personal use, not for redistribution. The definitive version was published in Proceedings of the Royal Society of London B 271 (2004): 227-231, doi:10.1098/rspb.2003.2570.North Atlantic right whales were extensively hunted during the whaling era and have not recovered. One of the primary factors inhibiting their recovery is anthropogenic mortality caused by ship strikes. To assess risk factors involved in ship strikes, we used a multi-sensor acoustic recording tag to measure the responses of whales to passing ships and experimentally tested their responses to controlled sound exposures, which included recordings of ship noise, the social sounds of conspecifics and a signal designed to alert the whales. The whales reacted strongly to the alert signal, they reacted mildly to the social sounds of conspecifics, but they showed no such responses to the sounds of approaching vessels as well as actual vessels. Whales responded to the alert by swimming strongly to the surface, a response likely to increase rather than decrease the risk of collision.Funding for this work was provided by the Fisheries Service of the US National Oceanic and Atmospheric Administration (contract no. NA87RJ0445), and was conducted under NOAA Fisheries permit to conduct scientific research no. 1014 issued to Dr Scott Kraus and Canadian Department of Fisheries and Oceans permits 2001-559 and 2002-568

Long-acting antituberculous therapeutic nanoparticles target macrophage endosomes.

Eradication of Mycobacterium tuberculosis (MTB) infection requires daily administration of combinations of rifampin (RIF), isoniazid [isonicotinylhydrazine (INH)], pyrazinamide, and ethambutol, among other drug therapies. To facilitate and optimize MTB therapeutic selections, a mononuclear phagocyte (MP; monocyte, macrophage, and dendritic cell)-targeted drug delivery strategy was developed. Long-acting nanoformulations of RIF and an INH derivative, pentenyl-INH (INHP), were prepared, and their physicochemical properties were evaluated. This included the evaluation of MP particle uptake and retention, cell viability, and antimicrobial efficacy. Drug levels reached 6 μg/10(6) cells in human monocyte-derived macrophages (MDMs) for nanoparticle treatments compared with 0.1 μg/10(6) cells for native drugs. High RIF and INHP levels were retained in MDM for \u3e15 d following nanoparticle loading. Rapid loss of native drugs was observed in cells and culture fluids within 24 h. Antimicrobial activities were determined against Mycobacterium smegmatis (M. smegmatis). Coadministration of nanoformulated RIF and INHP provided a 6-fold increase in therapeutic efficacy compared with equivalent concentrations of native drugs. Notably, nanoformulated RIF and INHP were found to be localized in recycling and late MDM endosomal compartments. These were the same compartments that contained the pathogen. Our results demonstrate the potential of antimicrobial nanomedicines to simplify MTB drug regimens

Why whales are big but not bigger : physiological drivers and ecological limits in the age of ocean giants

This research was funded in part by grants from the National Science Foundation (IOS-1656676, IOS-1656656; OPP-1644209 and 07-39483), the Office of Naval Research (N000141612477), and a Terman Fellowship from Stanford University. All procedures in USA were conducted under approval of the National Marine Fisheries Service (Permits 781-1824, 16163, 14809, 16111, 19116, 15271, 20430), Canada DFO SARA/MML 2010-01/SARA-106B, National Marine Sanctuaries (MULTI-2017-007), Antarctic Conservation Act (2009-014, 2015-011) and institutional IACUC committee protocols. Fieldwork, data collection and data processing for M. densirostris were funded by the Office of Naval Research grants N00014-07-10988, N00014-07-11023, N00014-08-10990, N00014-18-1-2062, and 00014-15-1-2553, and the U.S. Strategic Environmental Research and Development Program Grant SI-1539. PLT gratefully acknowledges funding from funding the MASTS pooling initiative (The Marine Alliance for Science and Technology for Scotland). MASTS is funded by the Scottish Funding Council (HR09011) and contributing institutions.The largest animals are marine filter feeders, but the underlying mechanism of their large size remains unexplained. We measured feeding performance and prey quality to demonstrate how whale gigantism is driven by the interplay of prey abundance and harvesting mechanisms that increase prey capture rates and energy intake. The foraging efficiency of toothed whales that feed on single prey is constrained by the abundance of large prey, whereas filter-feeding baleen whales seasonally exploit vast swarms of small prey at high efficiencies. Given temporally and spatially aggregated prey, filter feeding provides an evolutionary pathway to extremes in body size that are not available to lineages that must feed on one prey at a time. Maximum size in filter feeders is likely constrained by prey availability across space and time.PostprintPeer reviewe

Sex bias in biopsy samples collected from free-ranging dolphins

Author Posting. © The Author(s), 2009. This is the author's version of the work. It is posted here by permission of Springer for personal use, not for redistribution. The definitive version was published in European Journal of Wildlife Research 56 (2010): 151-158, doi:10.1007/s10344-009-0299-7.Biological samples of free-ranging dolphins are increasingly used to gain information on population structure and ecology. In small cetaceans, the gender of individuals usually cannot be determined at sea, and population sex ratio has to be inferred indirectly. We used molecular sexing to determine the gender of 340 biopsy samples of bottlenose dolphins, Tursiops truncatus, spotted dolphins, Stenella frontalis, and common dolphins, Delphinus delphis, collected around the Azores and Madeira. Sex ratio was globally skewed in favor of males, and differed between species and archipelagos. Skew was probably influenced by the selectivity of biopsy collectors and seasonal or year-round predominance of males in natural populations. Skew was also influenced by sampling duration and intensity. In the Azores, when several samples were successively collected within the same group, the proportion of female samples decreased as a function of sample order. This trend indicated a tendency for females to increasingly avoid the boat while samples were being collected. It showed that males and females reacted differently to the perturbation caused by the biopsy sampling process (i.e. sample collection and driving style).Portuguese Foundation for Science and Technology (FCT) and the FEDER program for funding the CETAMARH (POCTI/BSE/38991/01) and the GOLFINICHO (POCI/BIA-BDE/61009/2004) projects, S.Q.'s post-doctoral grants (IMAR/FCT- PDOC-006/2001-MoleGen and SFRH/BPD/19680/2004), M.A.S.'s doctoral (SFRH/BD/8609/2002) and post-doctoral (SFRH/BPD/29841/2006) grants, S.M.'s investigation assistant grant (CETAMARHII/POCTI/BSE/38991/2001) and I.C.'s investigation assistant grants (IMAR/FCT/GOLFINICHO/001/2005 and IMAR/FCT/GOLFINICHO/004/2006). FCT for its pluri-annual funding to Research Unit #531 and the EU funded program Interreg IIIb for funding the MACETUS project (MAC/4.2/M10) as well as R.P. and S.M.’s grants (IMAR/INTERREGIIIb/MACETUS/MAC1/2)

Super-Aggregations of Krill and Humpback Whales in Wilhelmina Bay, Antarctic Peninsula

Ecological relationships of krill and whales have not been explored in the Western Antarctic Peninsula (WAP), and have only rarely been studied elsewhere in the Southern Ocean. In the austral autumn we observed an extremely high density (5.1 whales per km2) of humpback whales (Megaptera novaeangliae) feeding on a super-aggregation of Antarctic krill (Euphausia superba) in Wilhelmina Bay. The krill biomass was approximately 2 million tons, distributed over an area of 100 km2 at densities of up to 2000 individuals m−3; reports of such ‘super-aggregations’ of krill have been absent in the scientific literature for >20 years. Retentive circulation patterns in the Bay entrained phytoplankton and meso-zooplankton that were grazed by the krill. Tagged whales rested during daylight hours and fed intensively throughout the night as krill migrated toward the surface. We infer that the previously unstudied WAP embayments are important foraging areas for whales during autumn and, furthermore, that meso-scale variation in the distribution of whales and their prey are important features of this system. Recent decreases in the abundance of Antarctic krill around the WAP have been linked to reductions in sea ice, mediated by rapid climate change in this area. At the same time, baleen whale populations in the Southern Ocean, which feed primarily on krill, are recovering from past exploitation. Consideration of these features and the effects of climate change on krill dynamics are critical to managing both krill harvests and the recovery of baleen whales in the Southern Ocean

Pathogenesis of HIV in the Central Nervous System

HIV can infect the brain and impair central nervous system (CNS) function. Combination antiretroviral therapy (cART) has not eradicated CNS complications. HIV-associated neurocognitive disorders (HAND) remain common despite cART, although attenuated in severity. This may result from a combination of factors including inadequate treatment of HIV reservoirs such as circulating monocytes and glia, decreased effectiveness of cART in CNS, concurrent illnesses, stimulant use, and factors associated with prescribed drugs, including antiretrovirals. This review highlights recent investigations of HIV-related CNS injury with emphasis on cART-era neuropathological mechanisms in the context of both US and international settings

Multiple-stage decisions in a marine central-place forager

Air-breathing marine animals face a complex set of physical challenges associated with diving that affect the decisions of how to optimize feeding. Baleen whales (Mysticeti) have evolved bulk-filter feeding mechanisms to efficiently feed on dense prey patches. Baleen whales are central place foragers where oxygen at the surface represents the central place and depth acts as the distance to prey. Although hypothesized that baleen whales will target the densest prey patches anywhere in the water column, how depth and density interact to influence foraging behaviour is poorly understood. We used multi-sensor archival tags and active acoustics to quantify Antarctic humpback whale foraging behaviour relative to prey. Our analyses reveal multi-stage foraging decisions driven by both krill depth and density. During daylight hours when whales did not feed, krill were found in deep high-density patches. As krill migrated vertically into larger and less dense patches near the surface, whales began to forage. During foraging bouts, we found that feeding rates (number of feeding lunges per hour) were greatest when prey was shallowest, and feeding rates decreased with increasing dive depth. This strategy is consistent with previous models of how air-breathing diving animals optimize foraging efficiency. Thus, humpback whales forage mainly when prey is more broadly distributed and shallower, presumably to minimize diving and searching costs and to increase feeding rates overall and thus foraging efficiency. Using direct measurements of feeding behaviour from animal-borne tags and prey availability from echosounders, our study demonstrates a multi-stage foraging process in a central place forager that we suggest acts to optimize overall efficiency by maximizing net energy gain over time. These data reveal a previously unrecognized level of complexity in predator–prey interactions and underscores the need to simultaneously measure prey distribution in marine central place forager studies.This is the publisher’s final pdf. The published article is copyrighted by The Royal Society and can be found at: http://rsos.royalsocietypublishing.org/Keywords: diving, predator-prey interactions, foraging decision

Krill Excretion Boosts Microbial Activity in the Southern Ocean

Antarctic krill are known to release large amounts of inorganic and organic nutrients to the water column. Here we test the role of krill excretion of dissolved products in stimulating heterotrophic bacteria on the basis of three experiments where ammonium and organic excretory products released by krill were added to bacterial assemblages, free of grazers. Our results demonstrate that the addition of krill excretion products (but not of ammonium alone), at levels expected in krill swarms, greatly stimulates bacteria resulting in an order-of-magnitude increase in growth and production. Furthermore, they suggest that bacterial growth rate in the Southern Ocean is suppressed well below their potential by resource limitation. Enhanced bacterial activity in the presence of krill, which are major sources of DOC in the Southern Ocean, would further increase recycling processes associated with krill activity, resulting in highly efficient krill-bacterial recycling that should be conducive to stimulating periods of high primary productivity in the Southern Ocean.This research is a contribution to projects ICEPOS (REN2002-04165-CO3-O2) and ATOS (POL2006-00550/CTM), funded by the Spanish Ministry of Science and Innovation

Scaling of maneuvering performance in baleen whales: larger whales outperform expectations

Despite their enormous size, whales make their living as voracious predators. To catch their much smaller, more maneuverable prey, they have developed several unique locomotor strategies that require high energetic input, high mechanical power output and a surprising degree of agility. To better understand how body size affects maneuverability at the largest scale, we used bio-logging data, aerial photogrammetry and a high-throughput approach to quantify the maneuvering performance of seven species of free-swimming baleen whale. We found that as body size increases, absolute maneuvering performance decreases: larger whales use lower accelerations and perform slower pitch-changes, rolls and turns than smaller species. We also found that baleen whales exhibit positive allometry of maneuvering performance: relative to their body size, larger whales use higher accelerations, and perform faster pitch-changes, rolls and certain types of turns than smaller species. However, not all maneuvers were impacted by body size in the same way, and we found that larger whales behaviorally adjust for their decreased agility by using turns that they can perform more effectively. The positive allometry of maneuvering performance suggests that large whales have compensated for their increased body size by evolving more effective control surfaces and by preferentially selecting maneuvers that play to their strengths.We thank the crews of many research vessels including the R/V John Martin, R/V Fluke, ARSV Laurence M. Gould, R/V Sanna, M/V Antonie, M/V Northern Song, the Cascadia Research Collective and the Shallow Marine Surveys Group; in particular, we thank John Douglas, Andrew Bell, Shaun Tomlinson, Steve Cartwright, Tony D'Aoust, Dennis Rogers, Kelly Newton, Heather Riley, Gina Rousa and Mark Rousa. We also thank Brandon L. Southall, Alison K. Stimpert and Stacy L. DeRuiter for their role in collecting data as part of the SOCAL-BRS project. We thank Matt S. Savoca, Julian Dale and Danuta M. Wisniewska for assistance with data collection. Finally, we thank John H. Kennedy, Michael A. Thompson and the NSF Office of Polar Programs.Ye