ICES coordinated acoustic survey of ICES divisions IIIa, IVa, IVb AND Via (North) 2002 Results and long term trends

Six surveys were carried out during late June and July covering most of the continental shelf north of 54oN in the North Sea and to the west of Scotland to a northern limit of 62oN. The eastern edge of the survey area was bounded by the Norwegian and Danish, Swedish and German coasts, and to the west by the shelf edge between 200 and 400 m depth. The surveys are reported individually in the report of the planning group for herring surveys, and a combined report has been prepared from the data from all surveys. The combined survey results provide spatial distributions of herring abundance by number and biomass at age by statistical rectangle; and distributions of mean weight and fraction mature at age. The estimates of North Sea autumn spawning herring are consistent with previous years at 2.9 million tonnes and 17,200 million herring. The survey also shows two exceptional year classes of herring (the 1998 and 2000 year classes) in the North Sea, which is consistent with the observation of exceptionally large year classes observed in the MIK and IBTS surveys. The estimates of Western Baltic spring spawning herring SSB are 255,000 tonnes and 2.9 millions (Table 2) and show a large increase compared with the previous year. The Western Baltic survey produces a rather noisy signal but the indications are of a stock that is higher now than between 1996 to 2000. The West of Scotland survey estimates of 548,000 tonnes and 2,900 million and shows the high 1995 year class again this year. The 1998 year class now (3 ring) is also a large one. Total adult mortality shows much lower mortality than last year (0.1 compared to 0.5 ) but the mean mortality over the last 4 years has been 0.3: this is consistent with the 2002 assessment that the stock is lightly exploited. The overall time series of abundance by age from 1989 to 2002 are summarised by simple models describing the spatial distribution over time. The changes over time with latitude, longitude and area occupied are compared with changes in abundance

Survey design and analysis procedures: a comprehensive review of good practice

This paper provides a major review of acoustic survey and-data analysis procedures, it has been prepared as a result of discussions in the FAST working group of ICES. A review of published literature is combined with an assessment of methodology. A consideration of information available a priori and its impact on the choice of survey area and survey design is presented. The subject of predetermined survey tracks using both systematic and random strategies is addressed, indicating the assumptions implied by these choices. Adaptive strategies that might be required for mobile or less predictable spatia1 distributions are discussed along with the advantages and the costs of an adaptive approach. The methods of determining of stock species composition are examined. The methods for assessing the degree of homogeneity species size and proportion are presented. The important choice of averaging method i.e. how the samples provide information on the true density within an area is examined. Sources of error within the estimate are discussed. Firstly, methods for computing the spatial sampling error are examined, and secondly, a summary of other sources of error is presented. A appraisal of these errors is presented and provides an intrinsic error analysis. Finally a brief comparison of the results of acoustic surveys with the results of other techniques is presented. Throughout the paper the assumptions implicit in each choice are discussed, and appropriate selections of survey design and analysis methods are presented in tabular form. The paper concludes with a summary of recommended procedures

Speed breeding in growth chambers and glasshouses for crop breeding and model plant research

‘Speed breeding’ (SB) shortens the breeding cycle and accelerates crop research through rapid generation advancement. SB can be carried out in numerous ways, one of which involves extending the duration of plants’ daily exposure to light, combined with early seed harvest, to cycle quickly from seed to seed, thereby reducing the generation times for some long-day (LD) or day-neutral crops. In this protocol, we present glasshouse and growth chamber–based SB approaches with supporting data from experimentation with several crops. We describe the conditions that promote the rapid growth of bread wheat, durum wheat, barley, oat, various Brassica species, chickpea, pea, grass pea, quinoa and Brachypodium distachyon. Points of flexibility within the protocols are highlighted, including how plant density can be increased to efficiently scale up plant numbers for single-seed descent (SSD). In addition, instructions are provided on how to perform SB on a small scale in a benchtop growth cabinet, enabling optimization of parameters at a low cost

Laser writing of coherent colour centres in diamond

Optically active point defects in crystals have gained widespread attention as photonic systems that can find use in quantum information technologies [1,2]. However challenges remain in the placing of individual defects at desired locations, an essential element of device fabrication. Here we report the controlled generation of single nitrogen-vacancy (NV) centres in diamond using laser writing [3]. The use of aberration correction in the writing optics allows precise positioning of vacancies within the diamond crystal, and subsequent annealing produces single NV centres with up to 45% success probability, within about 200 nm of the desired position. Selected NV centres fabricated by this method display stable, coherent optical transitions at cryogenic temperatures, a pre-requisite for the creation of distributed quantum networks of solid-state qubits. The results illustrate the potential of laser writing as a new tool for defect engineering in quantum technologies

Warm‐air advection, air mass transformation and fog causes rapid ice melt

Direct observations during intense warm-air advection over the East Siberian Sea reveal a period of rapid sea-ice melt. A semi-stationary, high-pressure system north of the Bering Strait forced northward advection of warm, moist air from the continent. Air-mass transfor-mation over melting sea ice formed a strong, surface-based temperature inversion in which dense fog formed. This induced a positive net longwave radiation at the surface, while reduc-ing net solar radiation only marginally; the inversion also resulted in downward turbulent heat flux. The sum of these processes enhanced the surface energy flux by an average of ~15 W m-2 for a week. Satellite images before and after the episode show sea-ice concentrations decreasing from > 90% to ~50% over a large area affected by the air-mass transformation. We argue that this rapid melt was triggered by the increased heat flux from the atmosphere due to the warm-air advection

Lessons for fisheries management from the EU cod recovery plan

The performance of the EU long-term management plan for cod stocks, in force since 2009, is analysed focusing on the human and institutional factors. The plan operates through landings quotas (TACs) and effort restrictions following a Harvest Control Rule, and deploys a novel instrument allowing Member States to ‘buy back’ or increase fishing effort for fleet segments engaged in cod-avoidance measures. The stipulated fishing mortality reductions have not been achieved. On the positive side, the ‘buy-back’ instrument has led to increased uptake of selective gear and implementation of permanent and real- time temporary closures. On the negative side, ignoring the dimension of fishers as reactive agents in the design, the impact assessment, and the annual implementation of the measures has contributed to the failure to adequately implement the plan and achieve its objectives.JRC.G.4-Maritime affair

Mead-halls of the Oiscingas: a new Kentish perspective on the Anglo-Saxon great hall complex phenomenon

Widely cited as a metaphor for the emergence of kingship in early medieval England, the great hall complex represents one of the most distinctive and evocative expressions of the Anglo-Saxon settlement record, yet interpretation of these sites remains underdeveloped and heavily weighted towards Yeavering. Inspired by the results of recent excavations at Lyminge, this paper undertakes a detailed comparative interrogation of three great hall complexes in Kent and exploits this new regional perspective to advance understanding of the agency and embodied meanings of these settlements as ‘theatres of power’. Explored through the thematic prisms of place, social memory and monumental hybridity, this examination leads to a new appreciation of the involvement of great hall sites in the genealogical strategies of 7th-century royal dynasties and a fresh perspective on how this remarkable yet short-lived monumental idiom was adapted to harness the symbolic capital of Romanitas

ICES coordinated acoustic survey of ICES divisions IIIa, IVa, IVb AND Via (North) 2002 Results and long term trends

Six surveys were carried out during late June and July covering most of the continental shelf north of 54oN in the North Sea and to the west of Scotland to a northern limit of 62oN. The eastern edge of the survey area was bounded by the Norwegian and Danish, Swedish and German coasts, and to the west by the shelf edge between 200 and 400 m depth. The surveys are reported individually in the report of the planning group for herring surveys, and a combined report has been prepared from the data from all surveys. The combined survey results provide spatial distributions of herring abundance by number and biomass at age by statistical rectangle; and distributions of mean weight and fraction mature at age. The estimates of North Sea autumn spawning herring are consistent with previous years at 2.9 million tonnes and 17,200 million herring. The survey also shows two exceptional year classes of herring (the 1998 and 2000 year classes) in the North Sea, which is consistent with the observation of exceptionally large year classes observed in the MIK and IBTS surveys. The estimates of Western Baltic spring spawning herring SSB are 255,000 tonnes and 2.9 millions (Table 2) and show a large increase compared with the previous year. The Western Baltic survey produces a rather noisy signal but the indications are of a stock that is higher now than between 1996 to 2000. The West of Scotland survey estimates of 548,000 tonnes and 2,900 million and shows the high 1995 year class again this year. The 1998 year class now (3 ring) is also a large one. Total adult mortality shows much lower mortality than last year (0.1 compared to 0.5 ) but the mean mortality over the last 4 years has been 0.3: this is consistent with the 2002 assessment that the stock is lightly exploited. The overall time series of abundance by age from 1989 to 2002 are summarised by simple models describing the spatial distribution over time. The changes over time with latitude, longitude and area occupied are compared with changes in abundance

Redirecting research efforts on the diversification-performance linkage: The search for synergy

We review the literature on the diversification-performance (D-P) relationship to a) propose that the time is ripe for a renewed attack on understanding the relationship between diversification and firm performance, and b) outline a new approach to attacking the question. Our paper makes four main contributions. First, through a review of the literature we establish the inherent complexities in the D-P relationship and the methodological challenges confronted by the literature in reaching its current conclusion of a non-linear relationship between diversification and performance. Second, we argue that to better guide managers the literature needs to develop along a complementary path – whereas past research has often focused on answering the big question of does diversification affect firm performance, this second path would focus more on identifying the precise micro-mechanisms through which diversification adds or subtracts value. Third, we outline a new approach to the investigation of this topic, based on (a) identifying the precise underlying mechanisms through which diversification affects performance; (b) identifying performance outcomes that are “proximate” to the mechanism that the researcher is studying, and (c) identifying an appropriate research design that can enable a causal claim. Finally, we outline a set of directions for future research