Recent financial innovations : courses, consequences for the payments system, and implications for monetary control

An abstract for this article is not availableFinancial markets ; Competition

Patterns of Reef Fish Larval Supply to Petroleum Platforms in the Northern Gulf of Mexico.

Surveys of ichthyoplankton assemblages were conducted from four oil and gas platforms located in the northern Gulf of Mexico from November 1994 through July 1997. Diurnal collections, supplemented with light trap collections from the surface and -20 m depth, were taken quarterly during 1994 and 1995. Quarterly ichthyoplankton sampling at dawn and dusk only during 1996 and 1997 were supplemented with surface lighted plankton net collections. Of the 36,676 individuals collected, epipelagic (neretic and oceanic Clupeiformes, neretic Carangidae and Lutjanidae, as well as oceanic Scombridae) and mesopelagic (Myctophidae and Gonostomatidae) families comprised the majority of the ichthyoplankton. Reef-dependent (e.g., Pomacentridae, Labridae, and Acanthuridae) families that dominated the adult fish communities at the platforms were either absent or very rare from both ichthyoplankton and light trap collections. Large-scale water mass movements, which primarily determine the transport of planktonic organisms as well as the linkage between potential source (natural reefs, hard bottom banks, and other platform structures) and sinks (platform artificial reef sites) were investigated with blended TOPEX/POSEIDON and ERS-2 radar altimetry. Serranid larvae collected from the plankton were aged by use of sagittal otoliths in order to estimate their transit time from natal source areas. Transit time in the plankton averaged 14.5 days. Seasonal transport envelopes showed that recruitment to mid-shelf and shelf-break platforms were influenced primarily by mesoscale warm-core and cold-core eddies. Within these seasonal envelopes, the numbers of artificial reef platforms potentially serving as source locations for recruitment greatly outnumbered the natural reef sites. Scuba diver and remotely operated vehicle surveys of juvenile and adult stage reef-dependent species were also conducted on the mid-shelf and shelf-break platforms. These were compared to underwater video footage of natural reef sites (National Marine Fisheries Service, SEAMAP fish trap/video gear) in order to establish correspondence between the taxa supplied to the platforms and the surrounding hard-bottom communities. Bray-Curtis similarity cluster analysis and multidimensional scaling of adult and juvenile reef-dependent fish communities showed that platform habitats had a biological character more like natural reef sites found in the eastern Gulf of Mexico, where little recruitment was shown to originate

A NOVEL PATH LOSS FORECAST MODEL TO SUPPORT DIGITAL TWINS FOR HIGH FREQUENCY COMMUNICATIONS NETWORKS

The need for long-distance High Frequency (HF) communications in the 3-30 MHz frequency range seemed to diminish at the end of the 20th century with the advent of space-based communications and the spread of fiber optic-connected digital networks. Renewed interest in HF has emerged as an enabler for operations in austere locations and for its ability to serve as a redundant link when space-based and terrestrial communication channels fail. Communications system designers can create a “digital twin” system to explore the operational advantages and constraints of the new capability. Existing wireless channel models can adequately simulate communication channel conditions with enough fidelity to support digital twin simulations, but only when the transmitter and receiver have clear line of sight or a relatively simple multi-path reflection between them. With over-the-horizon communications, the received signal depends on refractions of the transmitted signal through ionospheric layers. The time-varying nature of the free electron density of the ionosphere affects the resulting path loss between the transmitter and receiver and is difficult to model over several days. This dissertation examined previous efforts to characterize the ionosphere and to develop HF propagation models, including the Voice of America Coverage Analysis Prediction (VOACAP) tool, to support path loss forecasts. Analysis of data from the Weak Signal Propagation Reporter Network (WSPRnet), showed an average Root Mean Squared Error (RMSE) of 12.9 dB between VOACAP predictions and actual propagation reports on the WSPRnet system. To address the significant error in VOACAP forecasts, alternative predictive models were developed, including the Forecasting Ionosphere-Induced Path Loss (FIIPL) model and evaluated against one month of WSPRnet data collected at eight geographically distributed sites. The FIIPL model leveraged a machine learning algorithm, Long Short Term Memory, to generate predictions that reduced the SNR errors to an average of 4.0 dB RMSE. These results could support more accurate 24-hour predictions and provides an accurate model of the channel conditions for digital twin simulations. Advisor: Hamid R. Sharif-Kashan

The distribution and ecology of the Gammaridea (Crustacea : Amphipoda) of the lower Chesapeake estuaries

Gammarid amphipods of three tidal rivers entering Chesapeake Bay were studied for ten months, particularly in the York River where 40 species were record during the period. Several species moved up or down the rivers with changing salinity. The more abundant species had longer breeding seasons. The number of described species from lower Chesapeake Bay is now 42 and the presence of 10 undescribed species and of several which bracket the region indicates that much remains to be learned about amphipods in the Bay. Nineteen of these have a boreal affinity and seven are limited to the Virginian subprovince. A reference to the most recent significant work on each species is given and a key is included as an appendix

STATUS PENGELOLAAN PERIKANAN DENGAN PENDEKATAN EKOSISTEM: APLIKASI PADA NELAYAN KECIL KEPULAUAN KEI BESAR KABUPATEN MALUKU TENGGARA (WPPNRI 718)

This study aims to analyze the status of fisheries management based on the EAFM (Ecosystem Approach for Fisheries Management) approach and to recommend improvements to fisheries management based on the results of the EAFM assessment. This research was conducted from October to November 2021 in nine villages (ohoi) which are included in 4 sub-districts on Kei Besar Island Southeast Maluku Regency. Data were collected in several ways, including interviews with household and institutional fisheries, observation, and literature studies regarding 30 indicators in six EAFM domains. The status of fisheries management using the ecosystem approach in the Kei Besar Islands is categorized as good with a total aggregate value of 61.25 (light green) obtained based on management status per domainas follows: 1. Fish resource is categorized as good; 2. The habitat/ecosystem is categorized as average; 3. Fishing techniques are categorized as average; 4. Social is categorized as good; 5. Economic is categorized as good; and 6. Institutional is categorized as good. Management improvements should focus on: 1. Habitat and ecosystem domain, precisely the status of seagrass and mangrove ecosystems; 2. Fishing techniques domain on indicators such as fishing capacity and fishing effort, suitability of functions and size of vessels, and certification of fishing vessel crews; 3. Social domain on stakeholder participation indicators; and 4. Economic domain on household income indicators (RTP) by considering other domains and indicators.   ABSTRAK Penelitian bertujuan untuk menganalisis status pengelolaan perikanan berdasarkan pendekatan EAFM (Ecosystem Approach for Fisheries Management) serta merekomendasikan perbaikan pengelolaan perikanan berdasarkan hasil penilaian EAFM. Penelitian ini dilakukan pada bulan Oktober – Nopember 2021 pada 9 ohoi/desa yang termasuk dalam 4 kecamatan yang berada pada Pulau Kei Besar Kabupaten Maluku Tenggara. Pengumpulan data dilakukan melalui wawancara rumah tangga perikanan dan kelembagaan, observasi serta studi literatur terhadap 30 indikator pada enam domain EAFM. Status pengelolaan perikanan dengan pendekatan ekosistem di Kepulauan Kei besar Kabupaten Maluku Tenggara berada pada kategori baik dengan nilai agregat total sebesar 61,25 (hijau muda) yang diperoleh berdasarkan status pengelolaan per domain, masing-masing: 1. Domain sumberdaya ikan dalam kategori baik; 2. Domain habitat/ekosistem dalam kategori sedang; 3. Domain teknik penangkapan ikan dalam kategori sedang; 4. Domain sosial dalam kategori baik; 5. Domain ekonomi dalam kategori baik; dan 6. Domain kelembagaan dalam kategori baik. Upaya perbaikan pengelolaan harus lebih difokuskan pada: 1. Domain habitat dan ekosistem khususnya status ekosistem lamun dan mangrove; 2. Domain teknik penangkapan ikan pada indikator kapasitas perikanan dan upaya penangkapan, kesesuaian fungsi dan ukuran kapal, serta sertifikasi awak kapal perikanan; 3. Domain sosial pada indikator partisipasi pemangku kepentingan; dan 4. Domain ekonomi pada indikator pendapatan rumah tangga (RTP) dengan atau harus mempertimbangkan domain dan indikator lainnya. Kata Kunci: EAFM, sumberdaya ikan, nelayan, sosial ekonomi, Pulau Kei Besa

Strategy in space flight experiments

The main topics of the workshop were the evaluation of both the need for flight testing of solar array hardware and the opportunities for such testing. Spacecraft charging effects, array dynamics, cost-effectiveness, and methods of flight planning were also discussed