Mortality and blood loss by blue swimmer crabs (Portunus pelagicus) after simulated capture and discarding from gillnets

Two laboratory experiments were carried out to quantify the mortality and physiological responses of juvenile blue swimmer crabs (Portunus pelagicus) after simulated gillnet entanglement, air exposure, disentanglement, and discarding. In both experiments, all but control blue swimmer crabs were entangled in 1-m(2) gillnet panels for 1 h, exposed to air for 2 min, subjected to various treatments of disentanglement ranging between the forceful removal of none, one, two, and four appendages, then "discarded" into individual experimental tanks and monitored for 10 d. In Experiment 1, mortalities were associated with the number of appendages removed and the occurrence of unsealed wounds. In Experiment 2, live blue swimmer crabs were sampled for blood at 2 min and 6, 24, and 72 h post-discarding to test for the effects of disentanglement and appendage removal on total haemocyte counts, clotting times, protein levels (by refractive index), and blood ion concentrations. Compared with blue swimmer crabs that had sealed or no wounds, those with unsealed wounds had lower total haemocyte counts, protein, and calcium concentrations and increased clotting ties and magnesium and sodium levels. Induced autotomy, as opposed to the arbitrary, forceful removal of a appendages has the potential to minimize the mortality and stress of discarded, juvenile blue swimmer crabs.

Loss ratio of the EDF scheduling policy with early discarding technique

This paper considers a firm real-time M/M/1 system, where jobs have stochastic deadlines till the end of service. A method for approximately specifying the loss ratio of the earliest-deadline-first scheduling policy along with exit control through the early discarding technique is presented. This approximation uses the arrival rate and the mean relative deadline, normalized with respect to the mean service time, for exponential and uniform distributions of relative deadlines. Simulations show that the maximum approximation error is less than 4% and 2% for the two distributions, respectively, for a wide range of arrival rates and mean relative deadlines. (C) 2013 Elsevier B.V. All rights reserved.

Discarding Like Pieces

The guideline of ‘discarding like men’ to estimate the merit of a chess position is well known. This note compares it with some statistics.

By-catch and discarding practices in five Algarve (southern Portugal) metiers

The catches and discards of trawlers, seiners and trammel netters were studied in the Algarve (southern Portugal) using observers onboard commercial fishing vessels. Species diversity was high, with 236 species recorded as occasionally, frequently or regularly discarded. Mean discard rates per trip were 0.13, 0.20, 0.27, 0.62 and 0.70, respectively, for trammel nets, demersal purse seines, pelagic purse seines, fish trawls and crustacean trawls, with high variability in terms of discard volume and discard rate, This was especially so for se ncrs where from 0 to 100% of the total catch might be discarded. No significant relationships were found between discard quantity or discard rate and characteristics of the fishing vessels sampled within each metier (total length, TAB, hp, kW). Based on the above discard rates and the official landings, it was estimated that in 1996, Algarve trawlers discarded 9000-13000 tonnes (t) while seiners discarded 5500-8200 t. Discarding practices in these fisheries are reviewed and the reasons for discarding are presented by species and metier basis. The results support the need for more studies on the factors contributing to discarding, variability in discard quantities and rates, the fate of discards and their importance to the marine ecosystem, and on ways of reducing by-catch and discarding in these fisheries.

Detection and prevention of distributed denial of services attacks by collaborative effort of software agents, first prototype implementation

Distributed Denial of Services DDoS, attacks has become one of the biggest threats for resources over Internet. Purpose of these attacks is to make servers deny from providing services to legitimate users. These attacks are also used for occupying media bandwidth. Currently intrusion detection systems can just detect the attacks but cannot prevent / track the location of intruders. Some schemes also prevent the attacks by simply discarding attack packets, which saves victim from attack, but still network bandwidth is wasted. In our opinion, DDoS requires a distributed solution to save wastage of resources. The paper, presents a system that helps us not only in detecting such attacks but also helps in tracing and blocking (to save the bandwidth as well) the multiple intruders using Intelligent Software Agents. The system gives dynamic response and can be integrated with the existing network defense systems without disturbing existing Internet model. We have implemented an agent based networking monitoring system in this regard.

Geologically ancient DNA: fact or artefact?

Studies continue to report ancient DNA sequences and viable microbial cells that are many millions of years old. In this paper we evaluate some of the most extravagant claims of geologically ancient DNA. We conclude that although exciting, the reports suffer from inadequate experimental setup and insufficient authentication of results. Consequently, it remains doubtful whether amplifiable DNA sequences and viable bacteria can survive over geological timescales. To enhance the credibility of future studies and assist in discarding false-positive results, we propose a rigorous set of authentication criteria for work with geologically ancient DNA.

Combining multiple sensor modalities for a localisation robust to smoke

This paper proposes an approach to obtain a localisation that is robust to smoke by exploiting multiple sensing modalities: visual and infrared (IR) cameras. This localisation is based on a state-of-the-art visual SLAM algorithm. First, we show that a reasonably accurate localisation can be obtained in the presence of smoke by using only an IR camera, a sensor that is hardly affected by smoke, contrary to a visual camera (operating in the visible spectrum). Second, we demonstrate that improved results can be obtained by combining the information from the two sensor modalities (visual and IR cameras). Third, we show that by detecting the impact of smoke on the visual images using a data quality metric, we can anticipate and mitigate the degradation in performance of the localisation by discarding the most affected data. The experimental validation presents multiple trajectories estimated by the various methods considered, all thoroughly compared to an accurate dGPS/INS reference.

The French polisher and the unsentimental interior

In January 2011 a swollen Brisbane River broke its banks flooding riverside houses and buildings. The river’s water spread and rose up through storm water drains inundating some 20 000 houses in low-lying land. As the water receded those residents affected by the floods returned to their homes to assess the damage. While some people breathed a sigh of relief others were devastated by the overwhelming damage to their homes and personal belongings. Over the next few weeks the landscape of Brisbane was altered not merely by the mud and debris left by the torrent of water, but by the piles of domestic contents occupying Brisbane streets. Beds, toys, cabinets, plasterboard, tiles and household furniture lined curbsides waiting for collection. Later they would accumulate in public parks and sports centres to await disposal, momentarily creating an unsettling landscape of discarded domestic interiors. While most houses remained standing the heart breaking repercussions were evident in their interiority. Thousands of volunteers flocked to help those affected by the floods to purge the damage left by the water – removing wall and floor linings, discarding furniture and spoilt belongings. In her paper on Hurricane Katrina, Julieanna Preston wrote, ‘What anthropological evidence would we find as we followed their migration – heaps left by the side of the road, the physical weight overcoming the personal value…’ For many of the post flood restored homes and buildings entire interiors have been replaced, eradicating any trace of the significant event that disturbed them only months earlier. There were artifacts that would have survived the floods - furniture of solid timber – these were discarded and with them the patina that marked an important event in history. The patina is beyond technological reproducibility, and as Walter Benjamin writes, this being the whole premise of genuineness. It is the role of the French Polisher to maintain the true wear of the artefact for it is the patina that is most valuable in its ability to narrate the history of a piece. In 2012 two separate exhibitions in Brisbane will take place to display a selected collection of flood-damaged artefacts. This orchestrated way to commemorate the damage left by floods may be a method to compensate for the haste in which the damage was purged from the city. This need for exhibiting damaged artifacts illustrates Andreas Huyssen’s point that "…today memory is understood as a mode of re-presentation and as belonging to the present." This research looks at the dying trade of the French Polisher through conversations and a visual study of flood damaged furniture. The research also investigates the personal loss of artifacts through intimate stories shared by flood victims. This paper seeks to understand why so much was discarded and celebrate what remains.

Spatial and temporal variation and effects of changes in management in discard rates from the commercial reef line fishery of the Great Barrier Reef, Australia

Discarding in commercially exploited fisheries has received considerable attention in the last decade, though only more recently in Australia. The Reef Line fishery (RLF) of the Great Barrier Reef (GBR) in Australia is a large-scale multi-sector, multi-species, highly regulated hook and line fishery with the potential for high levels of discarding. We used a range of data sources to estimate discard rates and discard quantities for the two main target groups of the RLF, the coral trout, Plectropomus spp, and the red throat emperor, Lethrinus miniatus, and investigated possible effects on discarding of recent changes in management of the fishery. Fleet-wide estimates of total annual quantities discarded from 1989 to 2003 were 292-622 t and 33-95 t for coral trout and red throat emperor, respectively. Hypothetical scenarios of high-grading after the introduction of a total allowable commercial catch for coral trout resulted in increases in discard quantities up to 3895 t, while no high-grading still meant 421 t were discarded. Increasing the minimum size limit of red throat emperor from 35 to 38 cm also increased discards to an estimated 103 t. We provide spatially and temporally explicit estimates of discarding for the two most important species in the GBR RLF of Australia to demonstrate the importance of accounting for regional variation in quantification of discarding. Effects of management changes on discarding are also highlighted. This study provides a template for exploring discarding levels for other species in the RLF and elsewhere.

Survival of graded scallops amusium balloti in Queensland's (Australia) trawl fishery.

In the Queensland, Australia, scallop fishery, the scallop catch is graded at sea using a specially designed grading machine called a "tumbler." Experiments were conducted to determine the effect of repeated trawl capture, grading, and discarding on the survival of sublegal saucer scallops Amusium balloti. Scallops were caught within an area closed to commercial fishing and known to contain dense scallop beds. The trawled scallops were randomly divided into 2 groups, tumbled and control, and subjected to up to 4 tumbles and/or trawls before being caged for 2.5 days adjacent to the trawl grounds. Increased levels of both trawling and tumbling were found to decrease significantly the survival of sublegal scallops. Although 83% of scallops survived repeated intensive trawling (4 consecutive tows), survival fell to 64% when scallops were also graded using a commercial tumbler. Survival was high for both tumbled and control sublegal scallops after 1 trawl (97% and 98%, respectively).

Technical efficiency of blood component preparation in blood centres of 10 European countries

Various reasons, such as ethical issues in maintaining blood resources, growing costs, and strict requirements for safe blood, have increased the pressure for efficient use of resources in blood banking. The competence of blood establishments can be characterized by their ability to predict the volume of blood collection to be able to provide cellular blood components in a timely manner as dictated by hospital demand. The stochastically varying clinical need for platelets (PLTs) sets a specific challenge for balancing supply with requests. Labour has been proven a primary cost-driver and should be managed efficiently. International comparisons of blood banking could recognize inefficiencies and allow reallocation of resources. Seventeen blood centres from 10 countries in continental Europe, Great Britain, and Scandinavia participated in this study. The centres were national institutes (5), parts of the local Red Cross organisation (5), or integrated into university hospitals (7). This study focused on the departments of blood component preparation of the centres. The data were obtained retrospectively by computerized questionnaires completed via Internet for the years 2000-2002. The data were used in four original articles (numbered I through IV) that form the basis of this thesis. Non-parametric data envelopment analysis (DEA, II-IV) was applied to evaluate and compare the relative efficiency of blood component preparation. Several models were created using different input and output combinations. The focus of comparisons was on the technical efficiency (II-III) and the labour efficiency (I, IV). An empirical cost model was tested to evaluate the cost efficiency (IV). Purchasing power parities (PPP, IV) were used to adjust the costs of the working hours and to make the costs comparable among countries. The total annual number of whole blood (WB) collections varied from 8,880 to 290,352 in the centres (I). Significant variation was also observed in the annual volume of produced red blood cells (RBCs) and PLTs. The annual number of PLTs produced by any method varied from 2,788 to 104,622 units. In 2002, 73% of all PLTs were produced by the buffy coat (BC) method, 23% by aphaeresis and 4% by the platelet-rich plasma (PRP) method. The annual discard rate of PLTs varied from 3.9% to 31%. The mean discard rate (13%) remained in the same range throughout the study period and demonstrated similar levels and variation in 2003-2004 according to a specific follow-up question (14%, range 3.8%-24%). The annual PLT discard rates were, to some extent, associated with production volumes. The mean RBC discard rate was 4.5% (range 0.2%-7.7%). Technical efficiency showed marked variation (median 60%, range 41%-100%) among the centres (II). Compared to the efficient departments, the inefficient departments used excess labour resources (and probably) production equipment to produce RBCs and PLTs. Technical efficiency tended to be higher when the (theoretical) proportion of lost WB collections (total RBC+PLT loss) from all collections was low (III). The labour efficiency varied remarkably, from 25% to 100% (median 47%) when working hours were the only input (IV). Using the estimated total costs as the input (cost efficiency) revealed an even greater variation (13%-100%) and overall lower efficiency level compared to labour only as the input. In cost efficiency only, the savings potential (observed inefficiency) was more than 50% in 10 departments, whereas labour and cost savings potentials were both more than 50% in six departments. The association between department size and efficiency (scale efficiency) could not be verified statistically in the small sample. In conclusion, international evaluation of the technical efficiency in component preparation departments revealed remarkable variation. A suboptimal combination of manpower and production output levels was the major cause of inefficiency, and the efficiency did not directly relate to production volume. Evaluation of the reasons for discarding components may offer a novel approach to study efficiency. DEA was proven applicable in analyses including various factors as inputs and outputs. This study suggests that analytical models can be developed to serve as indicators of technical efficiency and promote improvements in the management of limited resources. The work also demonstrates the importance of integrating efficiency analysis into international comparisons of blood banking.

Giant mud crab (Scylla serrata): Relative efficiencies of common baited traps and impacts on discards

This study was initiated in response to a scarcity of data on the efficiency, selectivity and discard mortality of baited traps to target Scylla serrata. Five replicates of four traps, including "hoop nets", rigid "wire pots", and collapsible "round" and "rectangular" pots were deployed for 3, 6 and 24 h in two Australian estuaries. Trapped S. serrata were "discarded" into cages and monitored with controls over 3 d. All S. serrata were assessed for damage, while subsets of immediately caught and monitored individuals had haemolymph constituents quantified as stress indices. All traps retained similar-sized (8.119.1 cm carapace width) S. serrata, with catches positively correlated to deployment duration. Round pots were the most efficient for S. serrata and fishmostly Acanthopagrus australis (3 mortality). Hoop nets were the least efficient and were often damaged. No S. serrata died, but 18 were wounded (biased towards hoop nets), typically involving a missing swimmeret. Physiological responses were mild and mostly affected by biological factors. The results validate discarding unwanted S. serrata for controlling exploitation, but larger mesh sizes or escape vents in pots and restrictions on hoop nets would minimise unnecessary catches, pollution and ghost fishing. © 2012 International Council for the Exploration of the Sea. Published by Oxford University Press. All rights reserved.

Damage and physiological stress to juvenile eastern rock lobster (Sagmariasus verreauxi) discarded after trapping and hand collection

Large numbers of Sagmariasus verreauxi are trapped and hand collected in Australia, but discarded due to size and quota restrictions, and under the unevaluated assumption of few impacts. To test the validity of enforced discarding, trapped and hand-collected S. verreauxi (49-143. mm carapace length - CL) were examined for external damage, placed into cages, transferred to aquaria and monitored (with controls) over three months. Haemolymph was non-repetitively sampled immediately and at one, three, and seven days to quantify stress. Most trapped (64%) and hand-collected (79%) specimens were undersized (<104. mm CL), with the latter method yielding broader ranges of sizes and moult stages. Within-trap Octopus tetricus predation caused the only mortalities (3.3%). Hand collection resulted in much greater antennae and pereopod loss than trapping (53 vs. 4%) but, compared to controls, both methods evoked benign physiological responses that resolved within a week. While most wounded S. verreauxi regenerated all or some missing appendages post-moult, their mean CLs were less than those from intact conspecifics. Simple strategies, including larger mesh sizes, and/or installing modifications to reduce bycatch in traps, careful hand collection, and appropriate release techniques might minimise impacts (including predation) to unwanted S. verreauxi, and help to control stock exploitation. © 2012 Elsevier B.V.

Novel melody line identification algorithm for polyphonic MIDI music

The problem of automatic melody line identification in a MIDI file plays an important role towards taking QBH systems to the next level. We present here, a novel algorithm to identify the melody line in a polyphonic MIDI file. A note pruning and track/channel ranking method is used to identify the melody line. We use results from musicology to derive certain simple heuristics for the note pruning stage. This helps in the robustness of the algorithm, by way of discarding "spurious" notes. A ranking based on the melodic information in each track/channel enables us to choose the melody line accurately. Our algorithm makes no assumption about MIDI performer specific parameters, is simple and achieves an accuracy of 97% in identifying the melody line correctly. This algorithm is currently being used by us in a QBH system built in our lab.

Multiple scales without center manifold reductions for delay differential equations near Hopf bifurcations

We study small perturbations of three linear Delay Differential Equations (DDEs) close to Hopf bifurcation points. In analytical treatments of such equations, many authors recommend a center manifold reduction as a first step. We demonstrate that the method of multiple scales, on simply discarding the infinitely many exponentially decaying components of the complementary solutions obtained at each stage of the approximation, can bypass the explicit center manifold calculation. Analytical approximations obtained for the DDEs studied closely match numerical solutions.