Reducing overfishing and recovering overfished fish stocks is a challenging and important global problem. Rebuilding targets are essential ingredients for guiding overfished stocks to recovery. Having robust estimates of rebuilding... more
Reducing overfishing and recovering overfished fish stocks is a challenging and important global problem. Rebuilding targets are essential ingredients for guiding overfished stocks to recovery. Having robust estimates of rebuilding targets is likely a necessary condition for effective long-term management of fishery resources. In this paper, we show how Bayesian model averaging can be applied to estimate rebuilding targets under alternative hypotheses about stockrecruitment dynamics. Using alternative hypotheses about stockrecruitment dynamics and environmental variation is important because using only a single hypothesis can lead to substantially different reference points and policy implications. The alternative hypotheses are augmented with prior information collected from meta-analyses of stockrecruitment data to construct a set of age-structured production models. We illustrate our approach using three overfished New England groundfish stocks. We fit alternative model likeli...
Demand forecasting is one of the main challenges for retailers and wholesalers in any industry. Proper demand forecasting gives business valuable information about potential profits and helps managers in taking targeted decisions on... more
Demand forecasting is one of the main challenges for retailers and wholesalers in any industry. Proper demand forecasting gives business valuable information about potential profits and helps managers in taking targeted decisions on business growth strategies. Nowadays almost all organizations use different data sources or databases for nearly every aspect of their operations so that the knowledge on products on sale belongs to several independent views. The methodology described in this paper addresses the issue of product demand forecasting in fashion industry exploiting a multi-view learning approach. In particular, we show how the integration and connection among multiple views improves results accuracy. In real-life applications not all the views are usually available before a product is put on the market but the utility of a proper demand forecasting increases if the prediction is available before the product launch. We show that missing views can be reconstructed by means of common latent factors; in particular, this paper presents a learning procedure that describes the connection between different views. This connection allows data integration from multiple sources and can be extended to the special case of partial data representation. The nearest neighbors in the latent space play a special role for this process and for a general improvement of the forecast quality. We experimented the proposed methodology on real fashion retail sales showing that multi-view latent learning provides a system that is able to reconstruct satisfactorily non yet available views and can be used to predict the volumes of sales well before the goods are put on the market.
Aim This study investigated the use of stable δ13C and δ18O isotopes in the sagittal otolith carbonate of narrow-barred Spanish mackerel, Scomberomorus commerson, as indicators of population structure across Australia.Location Samples... more
Aim This study investigated the use of stable δ13C and δ18O isotopes in the sagittal otolith carbonate of narrow-barred Spanish mackerel, Scomberomorus commerson, as indicators of population structure across Australia.Location Samples were collected from 25 locations extending from the lower west coast of Western Australia (30°), across northern Australian waters, and to the east coast of Australia (18°) covering a coastline length of approximately 9500 km, including samples from Indonesia.Methods The stable δ13C and δ18O isotopes in the sagittal otolith carbonate of S. commerson were analysed using standard mass spectrometric techniques. The isotope ratios across northern Australian subregions were subjected to an agglomerative hierarchical cluster analysis to define subregions. Isotope ratios within each of the subregions were compared to assess population structure across Australia.Results Cluster analysis separated samples into four subregions: central Western Australia, north Western Australia, northern Australia and the Gulf of Carpentaria and eastern Australia. Isotope signatures for fish from a number of sampling sites from across Australia and Indonesia were significantly different, indicating population separation. No significant differences were found in otolith isotope ratios between sampling times (no temporal variation).Main conclusions Significant differences in the isotopic signatures of S. commerson demonstrate that there is unlikely to be any substantial movement of fish among these spatially discrete adult assemblages. The lack of temporal variation among otolith isotope ratios indicates that S. commerson populations do not undergo longshore spatial shifts in distribution during their life history. The temporal persistence of spatially explicit stable isotopic signatures indicates that, at these spatial scales, the population units sampled comprise functionally distinct management units or separate ‘stocks’ for many of the purposes of fisheries management. The spatial subdivision evident among populations of S. commerson across northern and western Australia indicates that it may be advantageous to consider S. commerson population dynamics and fisheries management from a metapopulation perspective (at least at the regional level).
Since the 1970s, when major improvements to the water quality were made, the River Thames has been subject to a high-profile project aimed at restoring Atlantic salmon to the catchment. Whilst initially successful, with hundreds of salmon... more
Since the 1970s, when major improvements to the water quality were made, the River Thames has been subject to a high-profile project aimed at restoring Atlantic salmon to the catchment. Whilst initially successful, with hundreds of salmon returning each year in the late 1980s, the number of adults returning to the river has declined steeply again in recent years, reaching a low in 2005 when no salmon were recorded. Using a baseline of genetic information gathered from 3830 salmon from throughout their southern European range, and incorporating samples from the hatchery fish used to stock the Thames, all 10 tagged hatchery fish captured in 2003 and all 16 returning untagged adult salmon captured between 2005 and 2008 were assigned to their most likely river of origin. The results suggest that untagged salmon currently ascending the river originate not from exogenous fish stocked into the Thames, but predominantly from other rivers in southern England. This highlights the potential for natural processes of recolonisation to operate in rivers where salmon have become locally extirpated. These findings also underscore several important considerations when undertaking species restoration projects: (i) previous causes of declines must be sufficiently ameliorated to allow new/translocated individuals to thrive, (ii) introduced individuals should originate from a stock that is closely related to the extirpated population, according to the principles of contemporary conservation biology, and (iii) dispersal and gene-flow from neighbouring populations may play a significant role in establishing new populations.► Despite an intensive hatchery stocking programme, since 2005 no hatchery reared salmon have been caught in the Thames. ► Genetic assignment analysis indicates that wild salmon ascending the Thames originate from other rivers in southern England. ► Wild salmon returning to the Thames between 2005 and 2008 do not originate from exogenous fish stocked into the Thames. ► Such straying highlights the potential for natural recolonisation of rivers where salmon have become locally extirpated. ► Our findings highlight the futility of long-term stocking without corresponding improvements in habitat and water quality.
Inventory is often the largest priced asset of a business after the fixed asset. Keeping the inventory also means keeping a tab on the realizable value, market value of all the stocks, stock in production and finished stock. This paper... more
Inventory is often the largest priced asset of a business after the fixed asset. Keeping the inventory also means keeping a tab on the realizable value, market value of all the stocks, stock in production and finished stock. This paper explores the challenges of manual inventory management system for supermarkets and infers solutions to the current challenges by designing a computerized inventory management system to order and update the stocks. The main method used for this research work is interview. Data were collected from 5 heterogeneous supermarkets and used as a tool for obtaining facts. When the goods were supplied the update of the stocks were being taken from time to time. The finding shows the challenges facing the manual system of inventory management system; the manual system requires everyday counting of items in the inventory, human errors are very prevalent during counting and recording and in case of disaster like fire or flood or poor communication, all the manual ...
تعد البورصة من أهم الآليات التي تساعد الدول على جذب الاستثمار إليها من جهة وتمويل الاستثمارات المتواجدة بها من جهة أخرى، وهو ما دفع إلى تحليل دور بورصة الجزائر في هذا المجال. وقد هدفت الدراسة إلى التعرف على مدى التأثير التي تفرضه بورصة... more
تعد البورصة من أهم الآليات التي تساعد الدول على جذب الاستثمار إليها من جهة وتمويل الاستثمارات المتواجدة بها من جهة أخرى، وهو ما دفع إلى تحليل دور بورصة الجزائر في هذا المجال. وقد هدفت الدراسة إلى التعرف على مدى التأثير التي تفرضه بورصة الجزائر في استقطاب الاستثمارات، وللوصول إلى ذلك تم الاعتماد على المنهجين الوصفي والتحليلي. وقد توصلت الدراسة إلى أن بورصة الجزائر، وبالرغم من قدم تاريخ إنشائها، إلا أنها لا تزال ترتب ضمن أضعف البورصات العالمية والعربية حيث أن حجم التداول بها لا يزال ضعيفا مقارنة بالمعدلات العالمية، كما أنها لا تستقطب إلا خمس مؤسسات جزائرية دون تسجيل مؤسسات أجنبية، ولا حتى حركة نشطة فعلية من قبل مؤسسات جزائرية أخرى. The stock market is one of the most important mechanisms that help countries to attract investment on the one hand, and financing of existing investments on the other hand, which prompted to examine the role of Algeria stock exchange in this area. The study aimed to identify the extent of the impact imposed by the Algeria stock exchange in attracting investments. To reach this aim, the study relied on the descriptive and analytical approaches, and it has concluded that the Algeria Stock Exchange still arranged within the weaker global and Arab stock exchanges where the volume of trading is still weak compared with international rates. It also do not attract only five Algerian companies without foreign companies registered, not even a real active movement by other Algerian companies.
A stock market, equity market or share market is the aggregation of buyers and sellers (a loose network of economic transactions, not a physical facility or discrete entity) of stocks (also called shares); these may include securities... more
A stock market, equity market or share market is the aggregation of buyers and sellers (a loose network of economic transactions, not a physical facility or discrete entity) of stocks (also called shares); these may include securities listed on a stock exchange as well as those only traded privately.
We find evidence of significant price manipulation at the stock level by hedge funds on critical reporting dates. Stocks in the top quartile by hedge fund holdings exhibit abnormal returns of 30 basis points in the last day of the month... more
We find evidence of significant price manipulation at the stock level by hedge funds on critical reporting dates. Stocks in the top quartile by hedge fund holdings exhibit abnormal returns of 30 basis points in the last day of the month and a reversal of 25 basis points in the following day. Using intraday data, we show that a significant
Models capable of estimating losses in future earthquakes are of fundamental importance for emergency planners and for the insurance and reinsurance industries. One of the main ingredients in a loss model is an accurate, transparent and... more
Models capable of estimating losses in future earthquakes are of fundamental importance for emergency planners and for the insurance and reinsurance industries. One of the main ingredients in a loss model is an accurate, transparent and conceptually sound algorithm to assess the seismic vulnerability of the building stock and indeed many tools and methodologies have been proposed over the past 30 years for this purpose. This paper takes a look at some of the most significant contributions in the field of vulnerability assessment and identifies the key advantages and disadvantages of these procedures in order to distinguish the main characteristics of an ideal methodology.
Growth of homogenous sized groups was studied in captive populations of Senegalese sole (Solea senegalensis Kaup) juveniles. An initial sole population was graded and three different sole stocks were obtained according to their respective... more
Growth of homogenous sized groups was studied in captive populations of Senegalese sole (Solea senegalensis Kaup) juveniles. An initial sole population was graded and three different sole stocks were obtained according to their respective size to form the homogenous ...
The Guinea Current Large Marine Ecosystem (GCLME) extending from Bissagos Island (Guinea Bissau) in the north to Cabinda (Angola) in the south defines the shared transboundary waters off the coast of western Africa, which embodies some of... more
The Guinea Current Large Marine Ecosystem (GCLME) extending from Bissagos Island (Guinea Bissau) in the north to Cabinda (Angola) in the south defines the shared transboundary waters off the coast of western Africa, which embodies some of the major coastal upwelling sub-ecosystems of the world and is an important centre of marine biodiversity and marine food production. The GCLME is characterized by distinctive bathymetry, hydrography, chemistry, and trophodynamics and represents the number 28 Large Marine Ecosystem (LME) ranked among the most productive coastal and offshore waters in the world with rich fishery resources. However, over-exploitation of fisheries, pollution from domestic and industry sources, habitat destruction and poorly planned and managed coastal developments and near-shore activities are resulting in a rapid depletion of the rich fisheries resources and degradation of vulnerable coastal and offshore habitats putting the economies, productivity and health of the populace at risk. Recognizing the urgency of the fisheries decline and the environmental and socio-economic consequences for the region, the 16 countries bordering the ecosystem have mobilized complementary resources to the funding from the Global Environment Facility and United Nations Industrial Development Organization to implement priority management actions agreed in the preliminary Strategic Action Programme for the recovery of depleted fish stocks and restoration of degraded habitats for the advancement of the achievement of the World Summit on Sustainable Development (WSSD) Johannesburg Plan of Implementation targets for recovery of fish stocks.
The present research investigates the effects of cash conversion cycle on economic value added among companies listed on Tehran's stock exchange. The sample of study includes 118 companies. The multivariate-regression method has been used... more
The present research investigates the effects of cash conversion cycle on economic value added among companies listed on Tehran's stock exchange. The sample of study includes 118 companies. The multivariate-regression method has been used for analysis of research hypotheses. Results indicated that a reverse and statistically significant relationship exists between companies' cash conversion cycle and their economic value added. In other words, by reducing the length of cash conversion cycle within reasonable limits, companies are able to increase their economic value added.