4,831 research outputs found
A BIOECONOMIC ANALYSIS OF THE NORWEGIAN SPRING SPAWNING HERRING (NSSH) STOCK
A biological model belonging to the Beverton-Holt age-structured family for the Norwegian spring spawning herring (Clupea harengus) (NSSH) is simulated, the outcome of which compares well with actual data on the fishery. This model is then combined with an economic model to help investigate how optimal a management policy of constant fishing mortality will be for a fishery such as the NSSH, which has a highly fluctuating stock biomass. For the range of constant values of fishing mortality explored, and a simulation time horizon of 20 years, a constant fishing mortality of 0.15 turns out to be economically optimal. It should be noted that this result is sensitive to variations in the assumptions underlying key variables of the fishery. For example, when a constant rather than variable recruitment was assumed, a different optimal fishing mortality rate was obtained.bioeconomic model, herring optimal management, Resource /Energy Economics and Policy, Q57, Q22, Q28,
ON THE DYNAMICS OF COMMERCIAL FISHING AND PARAMETER IDENTIFICATION
This paper has two main objectives. The first is to develop a dynamic model of commercial fisheries different from most existing models that assume optimizing behavior. The industry is assumed to have a well-defined index of performance. Based upon this index, the decision to invest or not is made. We do not, however, assume that the industry or firm is efficient or optimal in its operations. The second is that a new approach of fitting model dynamics to time series data is employed to simultaneously estimate the poorly known initial conditions and parameters of nonlinear fisheries dynamics. The approach is a data assimilation technique known as the variational adjoint method. Estimation of the poorly known initial conditions is one of the attractive features of the variational adjoint method.Resource /Energy Economics and Policy,
Komunikasi sebagai Upaya untuk Membangun Ketahanan Keluarga dalam Kajian Teori Nilai Etik
Keluarga merupakan fondasi utama bagi pembentukan karakter dan peran masing-masing anggotanya. Di samping itu, keluargajuga berperan utama terhadap pola interaksi yang ada di dalam kehidupan masyarakat. Namun, perkembangan dan perubahanyang terjadi pada masyarakat pun dapat mempengaruhi pola kehidupan keluarga. Dewasa ini, perkembangan ilmu pengetahuan dan teknologi mampu mempengaruhi bentuk struktur kehidupan masyarakat ke arah “masyarakat modern”, yang salah satu dampaknya berpengaruh terhadap struktur yang ditandai dengan terbatasnya tingkat intensitas pertemuan antar anggota keluarga karena tingginya aktivitas di luar rumah tangga, seperti; anak yang sekolah atau kuliah di luar kota, suami-istri yang berkarir, suami yang bekerja di luar kota, dan sebaliknya. Lebih lanjut, karena perkembangan alat komunikasi yang semakin maju, maka hal tersebut dapat dijadikan sebagai salah satu sarana untuk membangun ketahanan keluarga. Oleh karena itu, artikel ini akan coba menelaah sistem komunikasi sebagai unsur yang signifikan untuk membangun ketahanan keluarga melalui pendekatan historis (historical contex) dan pendekatan sosiologis, di mana pemaparannya dengan cara memadukan, mendeskripsikan, dan kemudian menganalisis fenomena sosial—pola kehidupan keluarga modern, perubahan dan perkembangan teknologi, komunikasi—menggunakan teori nilai etik melalui beberapa kaidah komunikasi Islam sebagai nilai berkomunikasi di dalam keluarga. Sehingga, apabila ditinjau dari “teori nilai etik” yang dikembangkan oleh Rahman, dapat diperoleh kesimpulan, bahwa terdapat beberapa unsur hubungan yang sangat erat terhadap prinsip-prinsip komunikasi Islam, perkembangan struktur keluarga, dan ketahanan keluarga sebagai jalan untuk membangun keluarga yang sakinah, mawaddah dan rahmah.Kata kunci: Komunikasi, Keluarga, Ketahanan Keluarga, Teori Nilai Eti
Epidemiology of antibiotic resistance in culture-positive hospitalized patients in selected hospitals in Khartoum, Sudan
Objective: To study the prevelence of antibiotic resistance and the prevalent bacterial isolates in hospitalized patients in Khartoum hospitals.
Materials & Methods: A cross-sectional prevalence study was carried out during the period of April–November 2015 in Khartoum; 226 bacterial cultures were included. Identification of isolates using standard biochemical tests and antibiotic susceptibilities were determined using disc diffusion method. Results were interpreted according to the standards of the British society of antimicrobial chemotherapy.
Results: Eight bacterial species were isolated: Staphylococcus aureus, Enterococcus faecalis, Streptococcus spp., Klebsiella pneumoniae, Pseudomonas spp., Escherichia coli, Proteus spp., and Acinetobacter spp. S. aureus was the most prevalent, the majority of which were resistant to methicillin/oxacillin (MRSA). Cultures in our study were mainly from urine (36.7%), blood samples (37.2%), and wound cultures (19%). More than 90% of the tested isolates were resistant to cefuroxime; 54% and 73.8% of Gram-positive and Gram-negative isolates, respectively, were resistant to ceftazidime. Furthermore, there was a high meropenem resistance among Gram-negative isolates tested. Multi-resistant Acinetobacter spp. as well as vancomycin-resistant S. aureus was isolated. Gram-negative isolates showed good susceptibilities to aminoglycosides as well as ciprofloxacin. However, the high resistance rate to these antibiotics was observed in Gram-positive isolates in these hospitals.
Conclusion: Methicillin-resistant S. aureus was the most prevalent organism. Gramnegative isolates showed good susceptibilities to aminoglycosides and ciprofloxacin. There were high resistance rates to cefuroxime, ceftazidime, and meropenem. Five vancomycin-resistant S. aureus were identified
Non-destructive Method of Leaf Area Estimation for Oleander (Nerium oleander L.) Cultivated in the Iraqi Kurdistan Region
This study was conducted in the Iraqi Kurdistan region in January 2014 to determine the individual leaf area of oleander (Nerium oleander L.) by easy, accurate, inexpensive, and nondestructive method. Simple, multiple and exponential regression analyses were used by length (L) and width (W) and their combinations as independent variables and with leaf area as dependent variable to determine more accurate models (high coefficient of determination and less MSE). The results showed that the best fitting models that show more accurate estimation of oleander leaf area, compared to other models, were the simple linear regression that depends on length multiple width for Koya and Erbil cities and the total leaves of the two cities plants. On the other hand, the best fitting multiple linear equations were those which depend on square length and square width for Koya city and the total leaves of the two cities plants, whereas for Erbil city the best model was that depends on leaves with square length and width. Multiple linear regressions were the more accurate among the models, followed by simple linear regression, whereas the exponential model had the lowest accuracy. All coefficients of regressions values were found to be significant at the P < 0.0001 level
Blockchain for Transforming International Trade: Bangladesh Perspective
Blockchain is one of the key pillars of the fourth industrial revolution and blockchain become an enormous excitement in many industries including the international trade ecosystem. As we move forward to the fourth industrial revolution, the digitalization of the traditional international trade process is vital. Research on blockchain technology in the field of international trade is very limited. The purpose of this qualitative study is to look at the blockchain application in the field of international trade for Bangladesh perspective. To find out a comprehensive view of blockchain in the international trade ecosystem, in-depth primary interview with relevant stakeholders was taken in addition to analyzing secondary data. The study found that blockchain can transform many parts of the existing international trade process in Bangladesh including customs, trade document management, trade method, payment, transport document, certifications and combating fraudulent activities.
Strategi Public Relations dalam Pengembangan Brand Image Sekolah di Sekolah Dasar Islam Terpadu (SDIT) Kota Samarinda
Public relation is an important aspect within the process of building positive image for an organization. Selecting appropriate strategy, therefore, must be applied very carefully since it determines the success or failure of the organization in the long run. This paper, thus, aims at explaining the strategy of public relation applied by Cordova Integral Islamic Elementary School in Samarinda in building a positive brand image that suits its’ long-term objectives. Utilizing qualitative approach, this paper finds out that Cordova Integral Islamic Elementary School in Samarinda applies four strategy such as research-listening, planning-decision, communication-action, and evaluation.Keywords: Image brand, organizational strategy, and public relation
Dynamic properties of crushed glass and tyre rubber in unbound pavement applications
Flexible pavements consist of treated unbound materials between the surface, typically bituminous, and the natural subgrade layer. A laboratory study was conducted to assess the dynamic behavior under the influence of repeated loads of the two most common global waste materials for their performance as road materials. The study investigated the behavior and properties of crushed rock (R) blended with waste glass (G) and tyre rubber (T) and evaluated them as alternatives to natural unbound materials. Preliminary tests included Modified Proctor compaction and Particle Size Distribution tests (before and after the compaction stage), and a more specialised test to determine the resilient modulus (Mr) and the permanent deformation values; the Repeated Triaxial Load Test (RLTT). The mixtures were prepared at different percentages of the whole specimen's total dry weight: from 12 to 45 % waste glass, and from 5 to 15 % tyre rubber. To simulate typical in situ materials, the mixtures were also prepared at the lower target moisture contents of 70% and 80% of OMC. The moisture content and the dry density after the RLTT were measured. Results showed a positive correlation between permanent deformation and glass content, while glass content can improve Mr value of rock specimens by up to 50%. Under RLTT, the addition of tyre rubber to crushed rock decreased permanent deformation
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