19 research outputs found

    Hyaluronan Hydrogels: Rheology and Stability in Relation to the Type/Level of Biopolymer Chemical Modification

    Get PDF
    BDDE (1,4-butanediol-diglycidylether)-crosslinked hyaluronan (HA) hydrogels are widely used for dermo-aesthetic purposes. The rheology and stability of the gels under physiological conditions greatly affect their clinical indications and outcomes. To date, no studies investigating how these features are related to the chemistry of the polymeric network have been reported. Here, four available HA-BDDE hydrogels were studied to determine how and to what extent their rheology and stability with respect to enzymatic hydrolysis relate to the type and degree of HA structural modification.1 H-/13 C-NMR analyses were associated for the quantification of the “true” HA chemical derivatization level, discriminating between HA that was effectively crosslinked by BDDE, and branched HA with BDDE that was anchored on one side. The rheology was measured conventionally and during hydration in a physiological medium. Sensitivity to bovine testicular hyaluronidase was quantified. The correlation between NMR data and gel rheology/stability was evaluated. The study indicated that (1) the gels greatly differed in the amounts of branched, crosslinked, and overall modified HA, with most of the HA being branched; (2) unexpectedly, the conventionally measured rheological properties did not correlate with the chemical data; (3) the gels’ ranking in terms of rheology was greatly affected by hydration; (4) the rheology of the hydrated gels was quantitatively correlated with the amount of crosslinked HA, whereas the correlations with the total HA modification level and with the degree of branched HA were less significant; (5) increasing HA derivatization/crosslinking over 9/3 mol% did not enhance the stability with respect to hyaluronidases. These results broaden our knowledge of these gels and provide valuable information for improving their design and characterization

    Movements and spatial use of odontocetes in the western main Hawaiian Islands: results from satellite-tagging and photo-identification off Kaua‘i and Ni‘ihau in July/August 2011

    Get PDF
    Although considerable information is available on residency patterns and spatial use of odontocetes in the eastern half of the Hawai‘i Range Complex (HRC), much less is known about odontocetes in the western half of the HRC. In the second year of a three-year effort in the western main Hawaiian Islands we undertook surveys off Kaua‘i and Ni‘ihau in July/August 2011, to examine spatial use and residency patterns using satellite tags, to provide visual verification of acoustically-detected odontocetes on the Pacific Missile Range Facility (PMRF), and to obtain individual identification photographs and biopsy samples for assessment of population identity and structure. During 18 days of field effort we covered 1,972 km of trackline and had 65 encounters with five species of odontocetes. Twenty-four of the encounters, of three species, were cued by acoustic detections from the Marine Mammal Monitoring on Navy Ranges (M3R) system, thus providing species verifications for future use of the M3R system on the PMRF range. During the 65 encounters we obtained 22,645 photos for individual and species identification, and collected 48 biopsy samples for genetic analyses. One encounter with a group of four killer whales was only the second encounter with this species in 12 years of directed field surveys in Hawaiian waters. Photos from that encounter were compared to our photo-identification catalog but no matches were found, further suggesting that there is no population of this species resident to the Hawaiian Islands. There were three encounters with a lone pantropical spotted dolphin, each time in association with a group of spinner dolphins. Photos of this individual matched to a spotted dolphin identified off Kaua‘i in 2004 and in 2005, both times with spinner dolphins, suggesting this individual may be part of a long-term association with spinner dolphins. Four satellite tags were deployed; three on rough-toothed dolphins and one on a bottlenose dolphin. These are the first tag deployments on either species in Hawaiian waters and the first deployments of satellite tags on free-ranging rough-toothed dolphins anywhere in the world. Rough-toothed dolphin tag data were obtained over periods from 7.6 to 18.5 days. Over these periods the three rough-toothed dolphins moved cumulative horizontal distances ranging from 573 to 1,295 km, yet remained an average distance from the tagging locations of from 10.4 to 13.9 km. Median depths used by the three rough-toothed dolphins ranged from 816 to 1,107 m, with median distance from shore ranging from 11.6 to 12.2 km. Two of the three individuals had been previously photo-identified off Kaua‘i (in 2007 or 2008), and all link by association with the resident population from Kaua‘i and Ni‘ihau. Movement and habitat use data were obtained over a 34-day period for the satellite-tagged bottlenose dolphin. During this time the individual remained associated with the island of Kaua‘i using waters with a median depth of 82 m. Although this individual had not been previously photo-identified, others from the group it was in had been previously documented off Kaua‘i and/or Ni‘ihau in 2003-2005, suggesting it is part of the island-resident population. Overall these efforts provide the first unbiased movement and habitat use data for both species in Hawaiian waters.Grant No. N00244-10-1-004

    Unexpected patterns of global population structure in melon-headed whales Peponocephala electra

    Get PDF
    Foraging specialization, environmental barriers, and social structure have driven the development of strong genetic differentiation within many marine species, including most of the large dolphin species commonly referred to as ‘blackfish’ (subfamily Globicephalinae). We used mitochondrial sequence data (mtDNA) and genotypes from 14 nuclear microsatellite loci (nDNA) to examine patterns of genetic population structure in melon-headed whales Peponocephala electra (MHWs), poorly known members of the blackfish family for which genetic structuring is unknown. MHWs are globally distributed in tropical and subtropical waters, and have formed resident populations around oceanic islands. They frequently mass strand, suggesting strong social cohesion within groups. Based on these characteristics, we hypothesized that MHWs would exhibit strong regional genetic differentiation, similar to that observed in other members of the Globicephalinae subfamily. Instead we found only moderate differentiation (median mtDNA ΩST = 0.204, median nDNA FST = 0.012) among populations both within and between ocean basins. Our results suggest that populations of MHWs that are resident to oceanic islands maintain a higher level of genetic connectivity than is seen in most other blackfish. MHWs may be more behaviorally similar to delphinids from the Delphininae subfamily (particularly the spinner dolphin Stenella longirostris), which are known to form coastal and island-associated resident populations that maintain genetic connectivity either through occasional long-distance dispersal or gene flow with larger pelagic populations. Our results suggest that differences in social organization may drive different patterns of population structure in social odontocete

    Near-Real-Time Acoustic Monitoring of Beaked Whales and Other Cetaceans Using a Seagliderℱ

    Get PDF
    In most areas, estimating the presence and distribution of cryptic marine mammal species, such as beaked whales, is extremely difficult using traditional observational techniques such as ship-based visual line transect surveys. Because acoustic methods permit detection of animals underwater, at night, and in poor weather conditions, passive acoustic observation has been used increasingly often over the last decade to study marine mammal distribution, abundance, and movements, as well as for mitigation of potentially harmful anthropogenic effects. However, there is demand for new, cost-effective tools that allow scientists to monitor areas of interest autonomously with high temporal and spatial resolution in near-real time. Here we describe an autonomous underwater vehicle – a glider – equipped with an acoustic sensor and onboard data processing capabilities to passively scan an area for marine mammals in near-real time. The glider was tested extensively off the west coast of the Island of Hawai'i, USA. The instrument covered approximately 390 km during three weeks at sea and collected a total of 194 h of acoustic data. Detections of beaked whales were successfully reported to shore in near-real time. Manual analysis of the recorded data revealed a high number of vocalizations of delphinids and sperm whales. Furthermore, the glider collected vocalizations of unknown origin very similar to those made by known species of beaked whales. The instrument developed here can be used to cost-effectively screen areas of interest for marine mammals for several months at a time. The near-real-time detection and reporting capabilities of the glider can help to protect marine mammals during potentially harmful anthropogenic activities such as seismic exploration for sub-sea fossil fuels or naval sonar exercises. Furthermore, the glider is capable of under-ice operation, allowing investigation of otherwise inaccessible polar environments that are critical habitats for many endangered marine mammal species

    Movements and Spatial Use of Odontocetes in the Western Main Hawaiian Islands: Results from Satellite-Tagging and Photo-Identification off Kaua'i and Ni'ihau in July/August 2011.

    Get PDF
    This report summarizes the second year of a three-year effort in the western main Hawaiian Islands to study the residency patterns and spatial use of odontocetes in the Hawaii Range Complex. Surveys were made off Kaua‘i and Ni‘ihau over eighteen days in July/August 2011, during which time there were 65 encounters with five species of odontocetes. Twenty-four of those encounters were cued by acoustic detections from the Marine Mammal Monitoring on Navy Ranges (M3R) system from the Pacific Missile Range Facility, thus providing species verifications of the acoustic system. Additionally, 22645 photographs for individual and species identification, and forty-eight biopsy samples for genetic analyses, were collected. Some highlights of the field work include: the first ever satellite tag deployments on free-ranging rough-toothed dolphins, and the first satellite tag deployment in Hawaiian waters of a bottlenose dolphin; only the second encounter with killer whales in twelve years of surveys in Hawaiian waters; and encounters with a lone pantropical spotted dolphin, always in association with a group of spinner dolphins, as has been similarly documented in 2004 and 2005. The latter two highlights suggest, respectively, that there is no resident Hawaiian killer whale population, and that this particular (at least) pantropical spotted dolphin has a long-term association with spinner dolphins. The first highlight has provided the first unbiased movement and habitat use data for both rough-toothed and bottlenose dolphins in Hawaiian waters.N00244-10-1-004

    Movement and spatial use of Odontocetes in the western main Hawaiian Islands: results of a three-year study off O'ahu and Kaua'i

    Get PDF
    Work was carried out by Cascadia Research Collective, Olympia, Washington 98501Understanding the impacts of anthropogenic activities on animal populations requires knowledge of their population structure, sizes and ranges. In Hawaiian waters this type of basic information has been lacking or is restricted to areas where conditions have been more favorable to research efforts, namely the eastern main Hawaiian Islands. As part of an effort to reduce uncertainty regarding the population, range and abundance of odontocetes in the western main Hawaiian Islands, and to help inform Navy impact assessments, we undertook small-boat based research efforts off O'ahu (2010) and Kaua'i (2011 & 2012). A variety of field methods were used, including photo-identification, collection of biopsy samples for genetic studies, and satellite tagging. There were 191 odontocete sightings, 183 identified to species. 102 biopsy samples were collected from 7 species. 30 satellite tags were deployed on 5 species: pygmy and false killer whales, bottlenose and rough-toothed dolphins, and short finned pilot whales. Our efforts substantially increased what is known in particular about the movements and habitat use of these 5 species of odontocetes in the western main Hawaiian Islands.CNO (N45) (N00244-10-1-0048

    Movements and spatial use of satellite tagged odontocetes in the western main Hawaiian Islands: results of field work undertaken off O'ahu in October 2010 and Kaua'i in February 2011

    Get PDF
    In the first year of a 3-year effort, surveys were made of odontocetes off Oahu and Kauai to examine spatial use and residency patterns in the western half of the Hawaii Range Complex using satellite tags, as well as obtaining individual identification photographs and biopsy samples for assessment of population identity and structure. 43 groups of 10 odontocete species were encountered, 15 satellite tags were deployed on 3 species, 39 genetic samples of 6 species and over 23000 photographs were obtained. Satellite tags were deployed on individuals in 2 groups of pygmy killer whales. Habitat use of the 2 groups differed substantially, and may be related to residency of the groups. Most individuals in one group had been previously photo-identified off Oahu. This group spent most of its time along the shores of Oahu, primarily in water 1000 m. Short-finned pilot whales were also tagged. Again, considerable variation in movement patterns and habitat use were observed: some groups remained close to the tagging area, suggesting residency; others ranged widely over varying depths. The differing ranging patterns may have implications for exposure and responses to Navy exercises.N00244-10-1-0048

    Serious game iDO: Towards better education in dementia care

    No full text
    We describe the iDO serious game developed during implementation of the Innovative Digital Training Opportunities on Dementia for Direct CareWorkers (IDO) project. The project targets formal and informal caregivers of persons with dementia in order to improve caregiver knowledge and competences skills with a non-traditional source of training. This paper describes the steps faced to define the iDO caregiver behavior improvement model, design of game mechanics, development of game art and game characters, and implementation of gameplay. Furthermore, it aimed to assess the direct impact of the game on caregivers (n = 48) and seniors with early signs of dementia (n = 14) in Lithuania measured with the Geriatric Depression Scale (GDS) and Dementia Attitudes Scale (DAS). The caregivers' GDS scores showed a decrease in negative answers from 13.4% (pre-game survey) to 5.2% (post-game survey). The seniors' GDS scores showed a decrease in negative answers from 24.9% (pre-game survey) to 10.9% (post-game survey). The overall DAS scores increased from 6.07 in the pre-game survey to 6.41 in the post-game survey, statistically significant for both caregivers and seniors (p < 0.001), respectively. We conclude that the game aroused positive moods and attitudes for future caregivers of persons with dementia, indicating a more relaxed status and a decreased fear in accomplishing the caring process
    corecore