Predicting reference points and associated uncertainty from life histories for risk and status assessment

To assess status of fish populations and the risks of overexploitation, management bodies compare fishing mortality rates and abundance estimates with reference points (RP). Generic, “data-poor” methods for estimating RP are garnering attention because they are faster and cheaper to implement than those based on extensive life history data. Yet data-poor RP are subject to many unquantified uncertainties. Here, we predict fishing mortality RP based on five levels of increasingly comprehensive data, to quantify effects of parameter and structural uncertainty on RP. Level I RP (least data) are estimated solely from species' maximum size and generic life history relationships, while level V RP (most data) are estimated from population-specific growth and maturity data. By estimating RP at all five data levels, for each of 12 North Sea populations, we demonstrate marked changes in the median RP values, and to a lesser extent uncertainty, when growth parameters come from data rather than life history relationships. As a simple rule, halving the median level I RP gives almost 90% probability that a level V median RP is not exceeded. RP and uncertainty were substantially affected by assumed gear selectivity; plausible changes in selectivity had a greater effect on RP than adding level V data. Calculations of RP using data for successive individual years from 1984 to 2014 showed that the median RP based on data for any given year would often fall outside the range of uncertainty for RP based on data from earlier or later years. This highlighted the benefits of frequent RP updates when suitable data are available. Our approach provides a quantitative method to inform risk-based management and decisions about acceptable targets for data collection and quality. Ultimately, however, the utility and extent of adoption of data-poor methods for estimating RP will depend on the risk aversion of managers

Analysis Of Ecotourism Income Organic Vegetables On Agroforestri Land Of Kidul Pujon Village Kecamatan Pujon, Malang District

Abstract: The purposes of this study is to determine the increase and development of income through organic vegetable ecotourism on agroforestry land. This research was conducted in Pujon Kidul Village, Tulungrejo Hamlet in June - October 2018.The approach taken is participatory rural assessment, modification of Participatory Rural Appraisal / PRA in agroforestry farmers. The technique of determining respondents in this study uses purposive sampling.Intensive results of agroforestry (agrisilviculture) analysis, average agroforestry farmer income from carrot vegetable crops reached Rp.5568,750, - / harvest, large red chili reached Rp.6,160,000, - / harvest, cabbage reached Rp.2,220,000, - / harvest , mustard reached Rp. 3,077,778, - / harvest, shallot reached Rp. 8,350,000 / harvest, leek onion reached Rp 2,258,333, - / harvest, cayenne reached Rp 9,833,333, - / harvest, brongkoli reached Rp. 4,800,000, - / harvest, and eggplant reach Rp. 195,238, - / harvest. The average farmer income for agroforestry received revenue reaching Rp. 13,603,488, with total costs reaching Rp. 4,468,247, and the average profit reached Rp. 935,242. B / C Ratio value of 3.34. With these average profits, farmers have the potential in terms of economic improvement for forest farmers to live well. The production of Perhutani gum has an average land area of 10.5 ha. From that area it produces sap 267.1 Kg / Ha. The average income from the sale of sap reaches Rp 801.257, - / Ha. The existing stands are P. merksuii with an average diameter of 15.35 cm, average stand height of 15.35 meters, and the average number of stands per hectare as many as 403.95 trees.Farmers need to increase existing land intensification by paying attention to the level of development of agroforestry land so that it can provide optimum ecological and economicimpacts to the community

Analisis Kelayakan Finansial Usaha Perikanan Tangkap dengan Alat Tangkap Trammel Net di Kabupaten Rembang

Penelitian ini bertujuan untuk mengetahui karakteristik usaha perikanan tangkap trammel net dan untuk menganalisis kelayakan usaha sisi finansial dari usaha perikanan tangkap trammel net di Kabupaten Rembang. Variabel kelayakan usaha finansial yang diteliti dalam penelitian ini adalah NPV (net present value), IRR (internal rate of return), dan payback periods. Penelitian ini menggunakan kombinasi data primer dan sekunder. Hasil penelitian menunjukkan bahwa usaha perikanan tangkap trammel net di Kabupaten Rembang merupakan usaha berskala mikro, dengan nilai investasi perahu rata-rata sebesar Rp 22,3 juta, nilai investasi alat tangkap rata-rata sebesar Rp 5,05 juta, dan nilai investasi mesin rata-rata sebesar Rp 4,92 juta, sedangkan biaya perawatan aset rata-rata sebesar Rp. 4,10 juta/tahun, biaya BBM rata-rata sebesar Rp. 12,96 juta/tahun, biaya es rata-rata sebesar Rp. 0,99 juta/tahun, biaya perbekalan rata-rata sebesar Rp. 6,40 juta/tahun dan raman kotor rata-rata sebesar Rp. 42,31 juta/tahun. Selain itu, juga dapat diambil kesimpulan bahwa usaha perikanan tangkap trammel net di Kabupaten Rembang bersifat feasible karena NPV bernilai positif (Rp 44,3 juta) dalam 10 tahun periode operasi penangkapan ikan, IRR (52%) lebih besar dari suku bunga yang ditetapkan dan payback periods (2,77 tahun) lebih cepat dari target waktu yang ditetapkan. This research aims to identified a characteristic of fishing business using trammel net and to analysed a financial feasibilty study to fishing business using trammel net in Regency of Rembang. Variable of research were NPV, IRR and payback periods. This research also used a primary and secondary data. This research proved if fishing business used trammel net in Rembang Regency could classify in micro-business, with investment cost average are Rp 22.3 million to boat, Rp 5.05 million to trammel net, and Rp 4.92 million to machine. Fishing business used trammel net in Rembang Regency also need Rp. 4.10 million/year to average of maintenance cost, Rp. 12.96 million/year to average of energy cost, Rp. 0.99 million/year to average of ice procurement cost, and Rp. 6.40 million/year to average of accomodation cost. The average of gross income in fishing business using trammel net was Rp. 42.31 million/year. This research proved if fishing business used trammel net was feasible, value of NPV was positive (Rp 44.3 million) in 10 years business operation, IRR (52%) greater than the target and payback periods (2.77 years) faster than the target

Ruddlesden-Popper Phase in Two-Dimensional Inorganic Halide Perovskites: A Plausible Model and the Supporting Observations.

A Ruddlesden-Popper (RP) type structure is well-known in oxide perovskites and is related to many interesting properties such as superconductivity and ferroelectricity. However, the RP phase has not yet been discovered in inorganic halide perovskites. Here, we report the direct observation of unusual structure in two-dimensional CsPbBr3 nanosheets which could be interpreted as the RP phase based on model simulations. Structural details of the plausible RP domains and domain boundaries between the RP and conventional perovskite phases have been revealed on the atomic level using aberration-corrected scanning transmission electron microscopy. The finding marks a major advance toward future inorganic halide RP phase synthesis and theoretical modeling, as well as unraveling their structure-property relationship

PERBEDAAN PENDAPATAN PENANGKAPAN IKAN ANTARA KAPAL PURSE SEINE DAN KAPAL LINEFISHING (Sekoci) DI LOKASI RUMPON DI PERAIRAN TELUK PRIGI KECAMATAN WATULIMO KABUPATEN TRENGGALEK PROPINSI JAWA TIMUR

This research was done at Prigi area Watulimo Sub-district Trenggalek residence at February 5th to 10th 2007.\ud This research aimed to find out the difference of fishing income at rumpon location with ‘purse seine’ and ‘line fishing’ tool by using income analysis, BEP (Break Even Point), PPC (Payback Period Cost), R/C (Return Cost Ratio).\ud Method used in this research was survey method with simple random sampling. According to the sampling research method above, there cold be found 7 respondents from 115 and 7 respondents from 36 respondents from population database which has complete information that the researcher needed. Production data taken was one year period data in 2006.\ud In this fishing, modal used for ‘purse seine’ fishing tool from 7 respondents for Rp 374.514.185,71 and for ‘line fishing’ was Rp 115.723.571,43.\ud For one year maintenance of 7 ‘purse seine’ respondents Rp 19.750.000,- and line fishing Rp 11.025.000. Un-conditional cost or ‘Purse Seine’ variable cost Rp 186.760.700 and line fishing was Rp 153.021.642,86. Total ‘Purse Seine’ cost was Rp 206.517.700,- and line fishing for Rp 163.167.267,86.\ud From the average income research in one year from 7 ‘Purse Seine’ tool respondents, there got Rp 312.000.000 and ‘line fishing’ tool for Rp 209.462.571,43. ‘Purse Seine’ income from 7 respondents Rp 106.796.371,43\ud By using BEP (Break Even Point) calculation, could be found that average selling BEP from 7 ‘Purse Seine’ respondents Rp 44.807.669,22 per year, price BEP Rp 3.476,64 per kg, and production BEP Rp 41.306,14 kg per year. For ‘Line fishing’ average selling BEP Rp 41.377.972,04 per year, price BEP Rp 4.752,04 per kg, and production BEP Rp 27.331,58 kg per year.\ud From the calculation by using PPC (Payback Periods Cost) to find out investment return from 7 respondents ‘Purse Seine’ tool, there found average PPC value 5 year 75 days and ‘Line Fishing’ was 3 year 4 days.\ud For R/C (Return Cost Ratio) from 7 ‘Purse Seine’ respondents there found average R/C 1,45 and R/C 1,28 for ‘Line Fishing’. Both fishing tools showed that they had the same efficient level, since both of them had R/C value more than 1, but ‘Purse Seine’ was more efficient, since larger the tool, more efficient it was.\ud For the research, by 1 year analysis to maximize fishing result, there hoped for the ship-owner to use optimal production factor, but the inhibitions was climate and the water area condition which caused un-certainty in their operation

Equilibrium and equivariant triangulations of some small covers with minimum number of vertices

Small covers were introduced by Davis and Januszkiewicz in 1991. We introduce the notion of equilibrium triangulations for small covers. We study equilibrium and vertex minimal $\mathbb{Z}_2^2$-equivariant triangulations of $2$-dimensional small covers. We discuss vertex minimal equilibrium triangulations of $\mathbb{RP}^3 \# \mathbb{RP}^3$, $S^1 \times \mathbb{RP}^2$ and a nontrivial $S^1$ bundle over $\mathbb{RP}^2$. We construct some nice equilibrium triangulations of the real projective space $\mathbb{RP}^n$ with $2^n +n+1$ vertices. The main tool is the theory of small covers.Comment: 15 pages, 10 figures, minor changes, accepted for publication in Journal of the Ramanujan Mathematical Societ

Logical Algorithms meets CHR: A meta-complexity result for Constraint Handling Rules with rule priorities

This paper investigates the relationship between the Logical Algorithms language (LA) of Ganzinger and McAllester and Constraint Handling Rules (CHR). We present a translation schema from LA to CHR-rp: CHR with rule priorities, and show that the meta-complexity theorem for LA can be applied to a subset of CHR-rp via inverse translation. Inspired by the high-level implementation proposal for Logical Algorithm by Ganzinger and McAllester and based on a new scheduling algorithm, we propose an alternative implementation for CHR-rp that gives strong complexity guarantees and results in a new and accurate meta-complexity theorem for CHR-rp. It is furthermore shown that the translation from Logical Algorithms to CHR-rp combined with the new CHR-rp implementation, satisfies the required complexity for the Logical Algorithms meta-complexity result to hold.Comment: To appear in Theory and Practice of Logic Programming (TPLP