353 research outputs found
Quantifying fishing activity targeting subsea pipelines by commercial trap fishers
No full textOver 1400 km of oil and gas pipeline infrastructure exists within the boundaries of the Pilbara Trap Managed Fishery (PTMF) operating on the North West Shelf of Australia. Some of this infrastructure has reached the end of its operational life and requires decommissioning. Location and speed data collected from 2008 to 2018 using vessel monitoring systems onboard all trap fishing vessels (n = 3) operating in the PTMF were used to understand how fishing activity near pipelines has changed through time, and to identify the best predictive variables to explain hours spent fishing km−2 week−1. The proportion of fishing activity within 200 m of a pipeline increased over the survey decade and averaged 4.2% across all years. Hours spent fishing km−2 within 200 m of any pipeline was found to be 8.0 h km−2, ~ 11.4 times more than that recorded, on average, for the remaining area of the PTMF (0.7 h km−2), and ~ 4.6 times more than the western portion of the PTMP (1.7 h km−2) where all pipeline infrastructure exists. Fishing activity within 1 km of pipelines increased after their installation, and hence time since installation was the best predictor of fishing. This study demonstrated that trap fishers in the PTMF allocate a small proportion of their time targeting pipeline infrastructure, with the area close to a pipeline experiencing a relatively greater magnitude of fishing than that elsewhere in the PTMF. As such, the results of this study provide decision makers with an understanding of the intrinsic value of this infrastructure to trap fishers
Accurate single-shot measurement technique for the spectral distribution of GeV electron beams from a laser wakefield accelerator
No full text© 2019 Author(s).We present a technique, based on a dipole magnet spectrometer containing multiple scintillation screens, to accurately characterize the spectral distribution of a GeV electron beam generated by laser wakefield acceleration (LWFA). An optimization algorithm, along with a numerical code, was developed for trajectory tracking and reconstructing the electron beam angle, divergence, and energy spectrum with a single-shot measurement. The code was validated by comparing the results with the Monte-Carlo simulation of electron beam trajectories. We applied the method to analyze data obtained from laser wakefield acceleration experiments performed using a multi-Petawatt laser to accelerate electron beams to multi-GeV energy. Our technique offers a high degree of accuracy to faithfully characterize electron beams with the nonnegligible shot-to-shot beam pointing fluctuations, particularly in the state-of-the-art multi-GeV LWFA experiments performed to push the energy frontier11sciescopu
Select works. With the portrait of the author.
No full textThe Vicar of Wakefield.--Poems.--Dramas.Mode of access: Internet.Cogswell
Pension Provision and Retirement Saving: Lessons from the United Kingdom
No full textWe describe the trajectory of pension reform in the United Kingdom, which has focussed on keeping the cost of public pension programmes down during a period of steady population ageing whilst attempting to maintain an adequate minimum level of income security for low income households in retirement. Instruments for achieving these aims have been to target public benefits on low income households, permitting individuals to opt out of the second tier of the public programme into private retirement accounts, and the use of tax incentives to encourage additional private retirement saving. Frequent reforms to the pension programme raise the question of whether households can make reasonable private retirement saving provision in the light of growing complexity and potential shortcomings in individual decision-making. This paper sheds some light on these issues.pensions, social security, retirement saving
El diario de Priscilla Scott-Ellis: enfermera en tiempo de guerra
No full textIntroduction:The use of letters, diaries and other sort of personal documents in historical research is a common andsolidly accepted practice among historians.Objective: To study the development of nursing in Spain during the Civil War, within the national zone, through the analysis the diary of Priscilla Scott-Ellis, as well as to analyse Priscilla's extraordinary personality within her personal-historical context.Methodology: A qualitative-descriptive research method was adopted, which facilitated the discovering, selection and classification of historical data, whose interpretation will help to enlighten the history of war nursing during the Spanish Civil War.Results: The information obtained though the analysis of the diary was classified within two main categories: a) Data related to the study of war nursing during the Spanish Civil War, and b) data concerning the life of Priscilla Scott-Ellis in Spain, both in the front and in the rearguard. In addition, a number of specific subcategories were established in order to assist the process of data codification and interpretation.Conclusions: The diary of Priscilla Scott-Ellis, edited by Raymond Carr, constitutes a valuable source of information on war nursing in Spain during the Civil War, revealing the exceptional personality of its young author
Latitudinal and temporal comparisons of the reproductive biology and growth of snapper, Pagrus auratus (Sparidae), in Western Australia
No full textThis study focused on obtaining sound quantitative data on the reproductive biology, length and age compositions and growth of the snapper Pagrus auratus in the waters off Carnarvon at ca 25oS and Perth at ca 32oS on the west coast of Australia and at ca 34oS on the south coast of Western Australia. Sampling thus encompassed both sub-tropical and temperate waters and the geographical range within which this species is abundant in Western Australia. The resultant data were used to explore the ways in which the biological characteristics of P. auratus differ with latitude and thus water temperature. An intensive sampling regime for eggs and spawning individuals of P. auratus was conducted in Cockburn Sound, a large marine embayment in the Perth region at ca 32oS. The resultant data were used to elucidate where and when spawning occurs in this large marine embayment and to determine more precisely the factors that influence the timing of spawning. The implications of the results presented in this thesis for the management of P. auratus, a species that has been subjected to very heavy fishing pressure in recent years, are discussed.
The time and duration of spawning of P. auratus in the subtropical waters of Carnarvon differed markedly from those recorded for this sparid in the temperate and cooler waters of the Perth and the south coast regions. Spawning at Carnarvon occurred predominantly in the five months between late autumn (May) and mid spring (September), whereas it took place mainly in the three months between mid spring (October) and early summer (December) in the Perth region. Spawning of P. auratus on the south coast occurred predominantly in October and November in 2003 and 2004 and scarcely at all in 2005. Gonadal recrudescence was thus initiated when water temperatures were close to their maximum but declining in Carnarvon, and close to their minima and rising in the Perth and south coast regions, respectively. The prevalence of fully mature and spawning females in all three regions was greatest in those months when water temperatures lay between 19 and 21oC. Collation of the data in this thesis and those provided in the literature for other populations showed that the spawning period was related to latitude, occurring far earlier in sub-tropical than temperate waters.
The females and males attained maturity at a far smaller total length (L50) in the Carnarvon region, i.e. 378 and 353 mm, respectively, than in the Perth region, 585 and 566 mm, respectively, and also the south coast region, i.e. 600 and 586 mm. The trends exhibited by the age at maturity parallel those for length, with the A50s for the two sexes increasing from ca 4 years in Carnarvon to ca 5.6 years in the Perth region and nearly 7 years in the south coast region. The L50 and A50 at maturity thus both increased with increasing latitude.
Marginal increment analysis demonstrated that, irrespective of the number of opaque zones in the otoliths of P. auratus, a single such opaque zone is laid down each year in these otoliths. Furthermore, the trends exhibited by the monthly marginal increments showed that the opaque zone is laid down predominantly in winter in the subtropical waters of Carnarvon, as opposed to mainly in spring in the temperate waters of the Perth and south coast regions. Thus, the timing of formation of the opaque zone in the otoliths of P. auratus along the Western Australian coast is not related to the trends exhibited by water temperature, but, in both the Carnvarvon and Perth regions, was coincident with the timing of spawning.
The maximum total lengths recorded for females and males in the Carnarvon region, i.e. 864 and 840 mm, respectively, were considerably less than the corresponding values of 1051 and 1056 mm in the Perth region, and 1083 and 1099 mm in the south coast region. Growth in the Perth and south coast regions was greater than in Carnarvon, as is reflected in, for example, the respective lengths of 820, 720 and 610 mm for females at 10 years of age, as determined from the von Bertalanffy growth equations.
The length and age compositions in the Carnarvon and south coast regions were essentially unimodal, whereas those in the Perth region were bimodal. However, the 'mode' in the length-frequency distribution for the south coast region was located well to the right of that in the Carnarvon region, reflecting relatively lower contributions by individuals of the age cohorts of 3 to 6 years. The marked bimodality in the length-frequency distribution for P. auratus in the Perth region was due to the presence of a group of mainly smaller individuals caught outside Cockburn Sound and another of mainly larger individuals that were caught in Cockburn Sound and which formed part of a spawning aggregation in that embayment.
The proportion of fish > 10 years old in the Carnarvon region declined markedly between 2003 and the following two years, presumably reflecting the effect of heavy fishing pressure. This contributed to the decision by fisheries managers to reduced the TAC in those waters after 2003. Age-frequency data demonstrated that annual recruitment success in Cockburn Sound varied greatly, with the 1991, 1992 and 1996 year classes being particularly strong, and recognizing that the relative numbers of the first two year classes did decline progressively between 2002 and 2004. Annual recruitment was particularly variable in the south coast region, with the catches of the 1996 year class dominating the samples.
The relative number of early stage P. auratus eggs in ichthyoplankton samples collected from Cockburn sound on each of four new moons during the spawning seasons of four consecutive years peaked in November in three of those years, i.e. 2001, 2003 and 2004, and in November/December in the remaining year, i.e. 2002. This showed that spawning in this embayment peaked during these months, at which times the mean sea surface temperatures ranged only from 19 to 20oC.
The prevalence of spawning fraction females in sequential samples demonstrated that spawning peaks at the new and, to a lesser extent, full moons. This helps account for the strong positive correlation between spawning fraction and tidal regime, with spawning being greatest when the tidal range is greatest.
Spawning times, back-calculated from the ages of the eggs collected during ichthyoplankton surveys in Cockburn Sound on each of 16 new moons within the spawning periods of four successive years, demonstrated that, in this embayment, P. auratus spawns at night and within the first three hours of the onset of the ebb tide. The distribution of egg concentrations on the 16 new moons showed that, each year, spawning occurred firstly in the north-eastern area of Cockburn Sound and then in the middle and finally north-western areas of this embayment.
In the Perth region, the marine embayments of Cockburn and Warnbro Sound act as nursery areas for P. auratus during the first two years of life. The majority of 2 to 5 year old fish and a large proportion of the 6 year old fish occupy the marine waters outside the embayments. The remaining 6 year old and almost all of the older fish begin to move in September into particularly Cockburn Sound, where they form relatively large spawning aggregations between October and December, before undergoing a massive emigration from this embayment in December/January. The limited returns from fish that were tagged in Cockburn Sound and were subsequently caught outside this embayment indicate that, following spawning, P. auratus does not tend to move in a particular direction.
Pagrus auratus stocks are heavily exploited in offshore, oceanic waters and in embayments, such as Cockburn Sound, where they are particularly susceptible to capture because of the tendency of this species to form spawning aggregations in these same easily accessible locations each year. The data obtained during this thesis show that the L50 at maturity of females and males in temperate waters, i.e. nearly 600 mm, is far greater than the current minimum legal length (MLL) of 410 mm TL. There is thus a need to increase the MLL and/or reduce fishing pressure on immature individuals in open waters. However, the effectiveness of an increase in the MLL may be limited because there is evidence that P. auratus suffers from fishing-induced barotrauma. Closures of specific areas during the spawning season of P. auratus, such as those that have been applied in Cockburn Sound and Shark Bay, are potentially a very effective method for reducing the effects of heavy fishing on spawning individuals
Fish assemblages associated with natural and anthropogenically-modified habitats in a marine embayment: Comparison of baited videos and opera-house traps
No full textMarine embayments and estuaries play an important role in the ecology and life history of many fish species. Cockburn Sound is one of a relative paucity of marine embayments on the west coast of Australia. Its sheltered waters and close proximity to a capital city have resulted in anthropogenic intrusion and extensive seascape modification. This study aimed to compare the sampling efficiencies of baited videos and fish traps in determining the relative abundance and diversity of temperate demersal fish species associated with naturally occurring (seagrass, limestone outcrops and soft sediment) and modified (rockwall and dredge channel) habitats in Cockburn Sound. Baited videos sampled a greater range of species in higher total and mean abundances than fish traps. This larger amount of data collected by baited videos allowed for greater discrimination of fish assemblages between habitats. The markedly higher diversity and abundances of fish associated with seagrass and limestone outcrops, and the fact that these habitats are very limited within Cockburn Sound, suggests they play an important role in the fish ecology of this embayment. Fish assemblages associated with modified habitats comprised a subset of species in lower abundances when compared to natural habitats with similar physical characteristics. This suggests modified habitats may not have provided the necessary resource requirements (e.g. shelter and/or diet) for some species, resulting in alterations to the natural trophic structure and interspecific interactions. Baited videos provided a more efficient and non-extractive method for comparing fish assemblages and habitat associations of smaller bodied species and juveniles in a turbid environment
Meta-stereotypes, social image and help seeking:dependency-related meta-stereotypes reduce help-seeking behaviour
No full textPeople who need help can be reluctant to seek it. This can be due to social image concerns. Here, we investigate if these concerns may be prompted by a salient negative meta-stereotype: the belief that one's group is judged negatively by another group. Specifically, we researched group members' help-seeking behaviour in the context of a dependency-related meta-stereotype. In a two-condition study (N=45), we manipulated participants' belief that their national group was judged dependent by a significant out-group. We then examined their subsequent help-seeking behaviour on a real-world task. Participants whose social identity as a group member was salient showed greater reluctance to seek help when the meta-stereotype was made prominent compared with when it was not. This suggests that, in a context where social image and social identity concerns are relevant, group members are willing to sacrifice the possibility of accessing needed help in order to avoid confirming a negative stereotype of their group. The implications of these results for helping transactions and community development are discussed
Keyword Co-articulatory Boundary Segmentation of the CRM Speech Corpus
No full textcrmSegmentCallColorDigitNow_v1 contains segmentation data for the CRM speech corpus [R. Bolia, W. Nelson, M. Ericson, and B. Simpson, “A speech corpus for multitalker communications research,” Journal of the Acoustical Society of America, vol. 107, pp. 1065-1066, 2000.] Each line of the file corresponds to one of the corpus utterances and contains the ID of the Talker, the audio filename, the sample frequency, and the start and stop sample indices for the Callsign, Color, Digit, and Now words. For example, the fourth line of the data
Talker: 0, Filename: 000003, SampleFreq: 44100, CallStart: 10557, CallStop: 26975, ColorStart: 40317, ColorStop: 48910, DigitStart: 52218, DigitStop: 63916, NowStart: 67223, NowStop: 79767
lists the samples indices for CallStart (10557), CallStop (26975), ..., NowStop (79767) for the file 000003.wav from Talker 0, where the first two elements in the filename indicate Callsign (0-7), the next two elements indicate Color (0-3), and the final two elements indicate Digit (0-7).
The results were obtained by pre-segmenting the data using a combination of acoustic features. Fine-tuning of the segmentation was performed by a single listener (the author, G. Wakefield) with particular emphasis placed on minimizing the co-articulatory "leakage" at the segment boundaries. It should be emphasized that these particular segment boundaries, particularly for the word offsets, are often judgment calls and are typically based on whether the following phoneme can be predicted on the basis of the current segmentation.Office of Naval Research (N00014-10-1-0152, N00014-13-1-0358)http://deepblue.lib.umich.edu/bitstream/2027.42/108223/1/crmSegmentCallColorDigitNow_v1.txtDescription of crmSegmentCallColorDigitNow_v1.txt : Dataset with explanatory heade
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