We found 47 articles for "Central Asia"
We found 47 articles for "Central Asia"
The boreal forest of Alberta, Canada is important breeding habitat for North American songbirds. Thousands of oil and gas wellsites exist in this region that have been actively reclaimed since the 1960s. Limited information exists on how songbirds respond to regeneration of wellsites following reclamation. Methods that provide spatially accurate data are required to determine impacts of these small disturbances characteristic of energy sector on songbirds. Acoustic localization can be used to determine singing locations, based on time of arrival differences of songs to an array of microphones. We used acoustic localization to determine the assemblage of songbirds on 12 reclaimed wellsites ranging from 7 to 49 years since reclamation, and how the similarity of this assemblage to 12 control mature forest sites (greater than 80 years old) changed with increasing canopy cover on the wellsite. Songbird community composition became more similar to mature forest as canopy cover increased on reclaimed wellsites. Results from this study suggest that wellsite reclamation practices are allowing for initial suitable vegetation recovery, however more research on the effectiveness of different strategies at promoting regeneration of wellsites and subsequent impact on songbird communities is required.
In recent years, China has evidently become a significant actor in the Arctic – a region located around the circumpolar north comprising territories of eight states and the Arctic Ocean. In 2013, China’s achievement of observer status at the Arctic Council – the high level inter-governmental forum of these eight circumpolar states – provided the country with legitimacy in its growing engagement with the Arctic region and its actors. A number of interests in the region motivates this engagement, most crucially that the Arctic is a resource rich region full of potential to further boost China’s local economy. The region contains, among other resources, approximately one-fourth of world’s undiscovered oil and gas resources. The increased melting of sea ice in the Arctic Ocean as a result of global warming is gradually opening access to water routes, and the region itself. The Arctic sea routes, in particular the Northern Sea Route (NSR), have already been identified as crucial navigation routes for China to expand its Belt and Road Initiative (BRI) to the Arctic. The expansion is now widely known as the Silk Road on the Ice or the Polar Silk Road wherein China closely cooperates with Russia and other Arctic states to promote the infrastructural development to operationalise the NSR. China’s investments in a number of projects are making the country an influential actor in the Arctic region. As such, China’s Arctic engagement is at times perceived as an attempt to enhance its ambitions, not only in terms of its economic interests, but also to move a step further towards gaining great power status in world politics. While China firmly commits to respect the sensitive environmental considerations existing in the Arctic and the sovereignty of the Arctic states, it also explicitly highlights its legitimate rights under international law, i.e., freedom of navigation through the Arctic sea routes. In this context, the following article explores the extension of China’s Silk Road Economic Belt to the Arctic vis-á-vis the possible geopolitical dynamics, and whether China’s increasing engagement in the Arctic accelerates its political ambition to expand its great power status.
Regional cooperation and integration are among the most important trends in contemporary international relations. The Central Asian republics of Kazakhstan, Kyrgyzstan, Tajikistan, Turkmenistan, and Uzbekistan have joined pre-eminent international organizations and institutions, such as the UN and OSCE. However, there are challenges, similarities and contradictions within the multilateral relationships in Central Asia (such as the Commonwealth of Independent States (CIS), Collective Security Treaty Organization (CSTO), Eurasian Economic Union (EEU), Shanghai Cooperation Organization (SCO), the Silk Road Economic Belt, Central Asia plus USA (C5+1), the EU strategy, Central Asia plus Japan, Central Asia–Republic of Korea and others). Moreover, there are link between local–regional–global processes in Central Asia. Descriptions and explanations must take into account particular local and regional situations, as well as internal and regional economies, cultures, and politics. Transformations are affected by the competitive international environment. Current and future Central Asian transformation will be prompted by interlinking local, regional, transregional, and global issues and challenges.
Biodiversity monitoring and assessment across a variety of gradients, could be achieved with the aid of the ecoacoustics discipline. Acoustic monitoring approaches can provide results regarding the species richness of birds, bats, frogs and insects including cicadas (Cicadoidea) and katydids (Tettigoniidae) with results similar to the ones provided by classical ecological methods (e.g. visual point count methods). The risk of extinction of several species has led to the creation of the Natura 2000 Network in the European Union’s territory. Greece provides a number of 202 Special Protection Areas (SPA’s) and 241 Sites of Community Importance (SCI), 239 of which are considered as Special Areas of Conservation (SAC). The specific areas provide both, an opportunity for ecoacoustics practice and an opportunity for ecoacoustic research. Even though the specific field of ecology has proven to be a valuable biodiversity assessment tool, areas that provide a variety of ecoacoustic events are yet to be documented. The goal of the specific article is to highlight these special conservation areas and propose a monitoring network using the non-invasive approach of ecoacoustics. For the specific research, the Greek protected areas were visualized in order to highlight sonotopes and soundtopes worthy of future research. Finally, in order to highlight the neglected issue of background noise regarding conservation efforts, the Kalloni’s salt pans were selected as a case study area. Noise measurements and sound recordings were conducted. Furthermore, noise and sound maps were created, in order to visualize the effects of noise.
Energy storage plays a critical role in facilitating penetration of renewable energy and reducing carbon emission of conventional energy system. Among various energy storage technologies, thermal storage allows energy to be stored in form of heat or cold so that it can be used, later on, for heating and cooling purposes as well as for power generation. Development of highly efficient and cost-effective thermal storage materials as well as the corresponding devices has attracted much attention. Composite materials based on latent heat storage (LHS) have shown great potential for many thermal storage applications. This paper firstly elaborates the recent progress in the study of micro-structured LHS composite materials in light of three different types of material synthesis methods including incorporation, impregnation and microencapsulation. Detailed discussions about morphology, performance enhancement of thermal storage and heat transfer, and various applications are carried out for current micro-structured LHS composite materials. The latest study progress in macro-structured LHS devices are then summarized, which includes the structural design of devices, optimization of heat transfer and device efficiency, as well as the performance of the devices with different storage media. Lastly, opportunities for future work are identified.
Soundscape analysis is a potentially powerful tool in ecosystem monitoring. Ecoacoustic metrics, including the Acoustic Complexity Index (ACI) and Acoustic Entropy (H), were originally developed for terrestrial ecosystems and are now increasingly being applied to investigate the biodiversity, habitat complexity and health of marine systems, with mixed results. To elucidate the efficacy of applying these metrics to marine soundscapes, their sensitivity to variations in call rate and call type were evaluated using a combination of field data and synthetic recordings. In soundscapes dominated by impulsive broadband snapping shrimp sounds, ACI increased non-linearly with increased snapping rate (∼100–3500 snaps/min), with a percent range of variation (∼40–50%) that exceeds that reported in most studies. H, however, decreased only slightly (∼0.04 units) in response to these same snap rate changes. The response of these metrics to changes in the rate of broadband snapping was not strongly influenced by the spectral resolution of the analysis. For soundscapes dominated by harmonic fish calls, increased rates of calling (∼5–120 calls/min) led to decreased ACI (∼20–40% range of variation) when coarse spectral resolutions (Δf = 94 or 47 Hz) were used in the analysis, but ACI increased (∼20% range of variation) when a finer resolution (Δf = 23 Hz) was employed. Regardless of spectral resolution used in the analysis, H decreased (∼0.20 units) in response to increased rates of harmonic calling. These results show that ACI and H can be modulated strongly by variations in the activity of a single sound-producing species, with additional sensitivity to call type and the resolution of the analysis. Variations in ACI and H, therefore, cannot be assumed to track call diversity, and the utility of these metrics as ecological indicators in marine environments may be limited.
In response to anthropogenic noise, many bird species adjust their song frequency, presumably to optimize song transmission and overcome noise masking. But the costs of song adjustments may outweigh the benefits during different stages of breeding, depending on the locations of potential receivers. Selection might favor unpaired males to alter their songs because they sing to attract females that may be widely dispersed, whereas paired males might not if mates and neighbors are primary receivers of their song. We hypothesized male house wrens (Troglodytes aedon) respond differently to noise depending on their pairing status. To test our hypothesis we synthesized pink noise, which mimics anthropogenic noise, and played it at three intensities in territories of paired and unpaired focal males. We recorded their songs and analyzed whether song structure varied with pairing status and noise treatment. To validate our study design, we tested whether noise playback affected measurement of spectral song traits and changed noise levels within territories of focal males. Consistent with our predictions, unpaired males sang differently than paired males, giving longer songs at higher rates. Contrary to predictions, paired males changed their songs by increasing peak frequency during high intensity noise playback, whereas unpaired males did not. If adjusting song frequency in noise is beneficial for long-distance communication we would have expected unpaired males to change their songs in response to noise. By adjusting song frequency, paired males reduce masking and produce a song that is easier to hear. However, if females prefer low frequency song, then unpaired males may be constrained by female preference. Alternatively, if noise adjustments are learned and vary with experience or quality, unpaired males in our study population may be younger, less experienced, or lower quality males.
Owing to its excellent thermal and mechanical properties of graphene, graphene-based composites have attracted tremendous research interest in recent years. In particular, graphene with high thermal conductivity becomes an important and promising filler in composites for thermal management. This critical review focus on the recent advances in graphene-based composites with high thermal conductivity. After the introduction of thermal conductive mechanisms of graphene-based composites, the fabrication methods of graphene-based composites are summarized. Then we also discuss currently researches of various graphene-based composites such as graphene/thermoplastic composites and graphene/thermoset composites. Herein, the mechanisms, preparation, and properties of graphene-based composites are discussed along with detailed examples from the scientific literature and the guidance are provided on the fabrication of composites with high thermal conductivity.
We report on a simple and practical application of HARK, an easily available and portable system for bird song localization using an open-source software for robot audition HARK, to a deeper understanding of ecoacoustic dynamics of bird songs, focusing on a fine-scaled temporal analysis of song movement — song type dynamics in playback experiments. We extended HARKBird and constructed a system that enables us to conduct automatic playback and interactive experiments with different conditions, with a real-time recording and localization of sound sources. We investigate how playback of conspecific songs and playback patterns can affect vocalization of two types of songs and spatial movement of an individual of Japanese bush-warbler, showing quantitatively that there exist strong relationships between song type and spatial movement. We also simulated the ecoacoustic dynamics of the singing behavior of the focal individual using a software, termed Bird song explorer, which provides users a virtual experience of acoustic dynamics of bird songs using a 3D game platform Unity. Based on experimental results, we discuss how our approach can contribute to ecoacoustics in terms of two different roles of sounds: sounds as tools and subjects.
Background noise can have a substantial effect on communication signals, however far less is known about how natural soundscapes may influence hearing sensitivity. Here we compare the audiograms of 26 wild beluga whales measured in their natural environment to a series of ecoacoustic measurements within a primary portion of their Bristol Bay summer habitat, the Nushagak Estuary in Bristol Bay, AK, USA. Environmental acoustic measurements were made during 2012 and 2016 using two different methods: a moored recorder and drifter buoys. Environmental noise curves varied substantially. Drifter recordings from the middle of Nushgak Estuary had the highest spectrum levels during ebb tides with acoustic energy from sediment transport extending well into higher frequencies (ca. 60 kHz), likely due to rapidly moving tidal flow and shifting sediment in that location. Drifter recordings near the estuary mouth and shallow tidal flats were lower amplitude. Noise levels generally varied during drifts (in one case up to ca. 6 dB) reflecting acoustic cues available to the local belugas. The moored recorder showed a substantially different spectral profile, especially at lower frequencies, perhaps due to its attachment to a pier piling and subsequent pier noise. Hearing sensitivity varied by individual and thresholds often fell above 1/3 octave-band noise levels, but not overall noise spectral density. Audiograms of the most sensitive animals closely paralleled the lowest ambient noise power spectral density curves, suggesting that an animal’s auditory dynamic range may extend to include its habitat’s quietest conditions. These data suggest a cautious approach is necessary when estimating the sound-sensitivity of odontocetes found in quiet environments as they may have sensitive auditory abilities that allow for hearing within the lowest noise-level conditions. Further, lower level ambient noise conditions could provide a conservative estimate of the maximal sensitivity of some cetacean populations within specific environments.
The article looks at the processes, metaphors and politics of the “Silk Road” as an ideological concept and the ways in which “authenticity” is actively constructed, implemented and performed as a strategy for development by government, non-governmental agencies and business owners. Case studies from Uzbekistan, Tajikistan and Kazakhstan are touched upon and material from interviews, observations and examples from material culture presented. This project seeks to analyse: the culture of the textiles business in Central Asia and how this operates at the seams of national-ethnic identity within the Eurasian context; the formal and informal business practices of the everyday, operating within the discourses of economic development; and how consumer culture may be interrogated as a means for performing identity at the local and global perspectives. Contemporary intersectional approaches to understanding the business of textiles and fashion in Central Asia should redress the marginalisation of academic efforts across multiple disciplines to unite the region inwardly and outwardly and call for an integrated approach to considering both the cultural and economic value of handmade textiles, which acknowledges and makes visible the role of the artisan, the designer, the entrepreneur, the retailer and all the stages that exist in the value chain between production the final consumer. The precursors to the current framework of research necessarily lie in the work of scholars of development and industrialisation established during the Soviet period. Their expertise must be called upon to enrich the perspective presented here, which is focused on contemporary craftsmanship and enterprise in Central Asia and how current practices in design and business may offer fruitful opportunities for development of the New Silk Road project, both intellectually and economically.
Passive acoustic monitoring is a potentially valuable tool in biodiversity hotspots, where surveying can occur at large scales across land conversion types. However, in order to extract meaningful biological information from resulting enormous acoustic datasets, rapid analytical techniques are required. Here we tested the ability of a suite of acoustic indices to predict avian bioacoustic activity in recordings collected from the Western Ghats, a biodiversity hotspot in southwestern India. Recordings were collected at 28 sites in a range of land-use types, from tea, coffee, and cardamom plantations to remnant forest stands. Using 36 acoustic indices we developed random forest models to predict the richness, diversity, and total number of avian vocalizations observed in recordings. We found limited evidence that acoustic indices predict the richness and total number of avian species vocalizations in recordings (R2 < 0.51). However, acoustic indices predicted the diversity of avian species vocalizations with high accuracy (R2 = 0.64, mean squared error = 0.17). Index models predicted low and high diversity best, with the highest residuals for medium diversity values and when continuous biological sounds were present (e.g., insect sounds >8 sec). The acoustic complexity index and roughness index were the most important for predicting avian vocal diversity. Avian species richness was generally higher among shade-grown crops than in the open tea plantation. Our results suggest that models incorporating acoustic indices can accurately predict low and high avian species diversity from acoustic recordings. Thus, ecoacoustics could be an important contributor to biodiversity monitoring across landscapes like the Western Ghats, which are a complex mosaic of different land-use types and face continued changes in the future.