566 research outputs found
Introduction
This collection seeks to encourage new ways of thinking about the connections and tensions between sexual politics, citizenship and belonging by bringing together a diverse range of critical interventions within sexuality and gender studies. The book is organised around three interlinked thematic areas, focusing on sexual citizenship, nationalism and international borders (section 1); sexuality and ârace â (section 2); and sexuality and religion (section 3). In revisiting notions of sexual citizenship and belonging, contributors engage with topical debates about âsexual nationalismâ, or the construction of western/European nations as exceptional in terms of attitudes to sexual and gender equality vis-Ă -vis an uncivilised, racialized âOtherâ.
The collection explores macro-level perspectives by attending to the broader geopolitical and socio-legal structures within which competing claims to citizenship and belonging are played out; at the same time, micro-level perspectives are utilised to explore the interplay between sexuality and âraceâ, nation, ethnicity and religious identities, both in individualsâ lived experiences and in activism and forms of collective belonging. Geographically, the collection has a prevalently European focus, yet contributions explore a range of trans-national spatial dimensions that exceed the boundaries of âEuropeâ and of European nation-states. They consider, for example, links between former European imperial powers and their former colonies; the construction of a European âcoreâ and its âperipheriesâ in discourses on sexual and reproductive rights; and forms of belonging shaped by migration from within and outside âfortress Europeâ
Far-field Unlabelled Super-Resolution Imaging with Superoscillatory Illumination
Unlabelled super-resolution is the next grand challenge in imaging. Stimulated emission depletion and single-molecule microscopies have revolutionised the life sciences but are still limited by the need for reporters (labels) embedded within the sample. While the Veselago-Pendry âsuper-lensâ using a negative-index metamaterial is a promising idea for imaging beyond the diffraction limit, there are substantial technological challenges to its realisation. Another route to far-field subwavelength focusing is using optical superoscillations: engineered interference of multiple coherent waves creating an, in principle, arbitrarily small hotspot. Here we demonstrate microscopy with superoscillatory illumination of the object and describe its underlying principles. We show that far-field images taken with superoscillatory
illumination are themselves superoscillatory and hence can reveal fine structural details of the object that are lost in conventional far-field imaging. We show that the resolution of a superoscillatory microscope is determined by the size of the hotspot, rather than the bandwidth of the optical instrument. We demonstrate high-frame-rate polarisation-contrast imaging of unmodified living cells with resolution significantly exceeding that achievable with conventional instruments. This non-algorithmic, low-phototoxicity imaging technology is a powerful tool both for biological research and for super-resolution imaging of samples that do not allow labelling, such as the interior of silicon chips
Summer circumpolar acoustic occurrence and call rates of Ross, Ommatophoca rossii, and leopard, Hydrurga leptonyx, seals in the Southern Ocean
DATA AVAILABILITY STATEMENT : The full dataset from the Scientific Committee on Antarctic Research cruise is available on the Dryad data repository (https://doi.org/10.5061/dryad.rr4xgxd79). Acoustic data from International Whaling Commissionâs Southern Ocean Whale and Ecosystem Research cruises are available upon request from the International Whaling Commissionâs offices.Two of the Antarctic pack ice seals, Ross, Ommatophoca rossii, and leopard, Hydrurga leptonyx, seals, are extremely difficult
to study via traditional visual survey techniques, yet are ideal for an acoustic survey as they are highly vociferous and
produce an array of underwater sounds during the austral summer. To determine their acoustic occurrence in the Antarctic
pack ice, we use their calls, detected within 680 acoustic recordings made between 1999 and 2009 as part of two multinational
programmes. Siren calls of Ross seals were detected mainly in January, and 9.88 calls per minute from low siren calls was
the highest call rate for this species. High numbers of Ross seal calls were detected close to the ice edge in areas between
0° and 20° E and 60° and 130° E, suggesting these are important summer habitats. Leopard seal calls were detected mainly
in December and January, and December had the highest percentage of calls. Call rate of 11.93 calls per minute from low
double trills was the highest call rate for leopard seals. Leopard seal calls were detected throughout the Southern Ocean with
more calls detected throughout the pack ice. There was little spatio-temporal overlap in call occurrence of Ross and leopard
seals, but both species were more vocally active during the day. Longitude and latitude were the most important predictors
of Ross seal occurrence, and month of the year highly predicted leopard seal occurrence. This is the first study to examine
the circumpolar acoustic occurrence of Ross and leopard seals in the Southern Ocean pack ice.International Whaling Commissionâs Southern Ocean Whale
and Ecosystem Research cruises were conducted by the International
Whaling Commission, and the Scientific Committee on Antarctic
Research cruise was funded by the Antarctic Scientific Advisory Committee
(ASAC 552 and 1140), the Sea World Research and Rescue
Foundation Inc. and the Scott Foundation.http://link.springer.com/journal/300am2022Mammal Research Institut
Species-specific characteristics and individual variation of the bark call produced by male Australian fur seals (Arctocephalus pusillus doriferus)
Australian fur seals Arctocephalus pusillus doriferus are colonial breeding animals forming dense social groups during the breeding season. During this time, males establish and defend territories through physical conflicts, stereotyped posturing and vocalisations. While vocalisations are suggested to play an important role in male recognition systems, it has received little attention. Recordings of nine adult male Australian fur seals were made during the 2000 and 2001 breeding seasons at Kanowna Island (39° 10’S, 146° 18\u27 E), Bass Strait, Australia. The in-air bark vocalisations of territory-holding males were used to characterise the Bark Call and to determine whether males produce individually distinct calls, which could be used as a basis for vocal recognition. Seventeen frequency and temporal variables were measured from a total of 162 barks from nine individual males. The Bark Series was more reliably classified (83%) to the correct caller compared to the Bark Unit. This was assigned with less certainty (68%), although the classification was still relatively high. Findings from this study indicate that there is sufficient stereotypy within individual calls, and sufficient variation between them, to enable vocal recognition in male Australian fur seals.<br /
Individual variation in the pup attraction call produced by female Australian fur seals during early lactation
Otariid seals (fur seals and sea lions) are colonial breeders with large numbers of females giving birth on land during a synchronous breeding period. Once pups are born, females alternate between feeding their young ashore and foraging at sea. Upon return, both mother and pup must relocate each other and it is thought to be primarily facilitated by vocal recognition. Vocalizations of thirteen female Australian fur seals (Arctocephalus pusillus doriferus) were recorded during the breeding seasons of December 2000 and 2001, when pups are aged from newborns to one month. The pup attraction call was examined to determine whether females produce individually distinct calls which could be used by pups as a basis for vocal recognition. Potential for individual coding, discriminant function analysis (DFA), and classification and regression tree analysis were used to determine which call features were important in separating individuals. Using the results from all three analyses: F0, MIN F and DUR were considered important in separating individuals. In 76% of cases, the PAC was classified to the correct caller, using DFA, suggesting that there is sufficient stereotypy within individual calls, and sufficient variation between them, to enable vocal recognition by pups of this species.<br /
Trash removal methods for improved mechanical emptying of pit latrines using a screw auger
Trash in pit latrines is one of the largest challenges facing pit emptying technologies, including the powered auger (the Excrevator), developed for improved emptying in lower- and lower-middle income countries. This study focused on two trash removal methods in conjunction with pit emptying by the Excrevator: (1) simultaneous removal of trash with sludge and (2) manual trash removal prior to sludge removal. Simultaneous removal was tested by adding to the inlet of the Excrevator system two cutting heads designed to reduce the size of trash particles before entering the pipe and auger. Laboratory testing indicated that the auger will not provide the rotational speeds necessary for proper maceration of fibrous materials such as clothing, indicating that a separate maceration unit with higher rotational methods may be more appropriate. Four manual trash removal mechanisms were designed to improve on existing manual trash âfishingâ tools such as iron rods with fixed hooks. Two of these tools (the âclawâ and the âhookâ) showed promising laboratory results and were subsequently field tested in Mzuzu, Malawi. Both tools proved more efficient than the current tools used in the field and have potential for use in Malawi
Evolutionary predictors of mammalian home range size: body mass, diet and the environment
ABSTRACT Aim Mammalian home range patterns provide information on spatial behaviour and ecological patterns, such as resource use, that is often used by conservation managers in a variety of contexts. However, there has been little research on home range patterns outside of the terrestrial environment, potentially limiting the relevance of current home range models for marine mammals, a group of particular conservation concern. To address this gap, we investigated how variation in mammalian home range size among marine and terrestrial species was related to diet, environment and body mass. Location Global. Methods We compiled data on home range size, environment (marine and terrestrial), diet and body mass from the literature and empirical studies to obtain a dataset covering 462 mammalian species. We then used phylogenetic regression analyses (to address non-independence between species) to examine the relative contribution of these factors to variation of home range size among species. Results Body size explained the majority of the difference in home range size among species (53-85%), with larger species occupying larger home ranges. The type of food exploited by species was also an important predictor of home range size (an additional 15% of variation), as was the environment, but to a much lesser degree (1.7%). Main conclusions The factors contributing to the evolution of home ranges are more complex than has been assumed. We demonstrate that diet and body size both influence home range patterns but differ in their relative contribution, and show that colonization of the marine environment has resulted in the expansion of home range size. Broad-scale models are often used to inform conservation strategies. We propose that future integrative models should incorporate the possibility of phylogenetic effects and a range of ecological variables, and that they should include species representative of the diversity within a group
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Density Can Be Misleading for Low-Density Species: Benefits of Passive Acoustic Monitoring
Climate-induced changes may be more substantial within the marine environment, where following ecological change is logistically difficult, and typically expensive. As marine animals tend to produce stereotyped, long-range signals, they are ideal for repeatable surveying. In this study we illustrate the potential for calling rates to be used as a tool for determining habitat quality by using an Antarctic pack-ice seal, the leopard seal, as a model. With an understanding of the vocal behavior of a species, their seasonal and diurnal patterns, sex and age-related differences, an underwater passive-acoustic survey conducted alongside a visual survey in an arc of 4,225 km across the Davis Sea, Eastern Antarctica, showed that while acoustic and visual surveys identified similar regions as having high densities, the acoustic surveys surprisingly identified the opposite regions as being 'critical' habitats. Density surveys of species that cannot be differentiated into population classes may be misleading because overall density can be a negative indicator of habitat quality. Under special circumstances acoustics can offer enormous advantage over traditional techniques and open up monitoring to regions that are remote, difficult and expensive to work within, no longer restricting long-term community assessment to resource-wealthy communities. As climatic change affects a broad range of organisms across geographic boundaries we propose that capitalizing on the significant advances in passive acoustic technology, alongside physical acoustics and population modeling, can help in addressing ecological questions more broadly
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Improving the sensitivity of cochlear implant integrity testing by recording electrode voltages with surface electrodes
Introduction: Identification of faults with the internal, implanted, part of a cochlear implant presents a challenge for the cochlear implant community. Advanced Bionics Ultra V1 devices are vulnerable to moisture ingress, a hard failure, resulting in reduced volume and clarity for the recipient. The manufacturer uses a trans-impedance test âElectrical Field Imagingâ to identify faulty Ultra V1 devices but reports the sensitivity of the test to be only 70â90%.
Methods: In our clinic we performed Electrode Voltage measurements with surface electrodes and have compared the two tests. Electrical Field imaging and Electrode Voltage (EV) measurements were available for 65 devices. Surface electrodes were attached to the earlobes and forehead and potentials measured in three montages: ipsilateral earlobe and forehead, contralateral earlobe and forehead, and both earlobes; voltages were extracted and relative voltages across the array were calculated.
Results: Relative EV were compared for the two earlobes montage and fitted to a third order polynomial function. A new criterion for identifying faulty devices was derived, with a deviation of N = 15) had a normal electrical field imaging test, whilst 17/50 devices which were abnormal had normal electrical field imaging and 33/50 which were abnormal had abnormal electrical field imaging.
Discussion: The REVs test was well-tolerated and carried out in a routine cochlear implant clinic. Together with test sensitivity and reliability this may make it a new routine assessment tool to aid in distinguishing hard and soft failures
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