scholarly journals Status Pemanfaatan Perikanan Tuna Madidihang (Thunnus albacares) Berdasarkan Model Biologi Schaefer

2018 ◽  
Vol 9 (1) ◽  
pp. 65
Author(s):  
Abgusta Fajri Wiranata ◽  
Budy - Wiryawan ◽  
Sugeng Hari Wisudo ◽  
Nimmi - Zulbainarni
Keyword(s):  
Linear Regression ◽  
Population Growth ◽  
Growth Function ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Quadratic Regression ◽  
Maximum Production ◽  
The Difference ◽  
Tuna Fishery

<p><em>There are two types of population growth function  of the basic formulation of Schaefer’s biology model, however in this study there is a difference in form and value of “r” as one of a biology parameter.   In addition  to the difference in the method by calculating the process of a and b coefficient. The calculating process of a and b coefficient in Schaefer’s biology model was conducted through linear regression which has not yet been exact.  This is  due to  the model itself which is quadratic. Therefore to provide the solution is through quadratic process. The linear regression shows the value of f<sub>msy</sub></em> and <em>Y<sub>msy </sub>1.40 and 1.34 times smaller than quadratic process respectively. Based on the two graphs from the calculating process of a and b coefficient, it can be concluded that the utilization of yellowfin tuna fishery was still not optimal. According to the result based on the linear and quadratic regression, the maximum production of yellowfin tuna  can be increased to 664,037 and 877,340 kg.</em></p><p class="TubuhTulisanAll"><strong><em>Keywords:</em></strong><strong><em> </em></strong><em>Population growth function, Schaefer’s Biology Model,</em><em> </em><em>Utilization status</em>, <em>Yellowfin tuna</em></p><p class="TubuhTulisanAll"><em><br /></em></p><p align="center"><strong>ABSTRAK</strong></p><p>Dua jenis fungsi pertumbuhan populasi menjadi dasar pembentukan model biologi Schaefer, namun dalam kajian ini terdapat perbedaan dalam bentuk dan nilai <em>r</em> sebagai parameter biologi ditambah juga berdasarkan perbedaan metode perhitungan koefisien <em>a</em> dan <em>b</em>. Metode perhitungan koefisien <em>a</em> dan <em>b</em> model biologi Schaefer melalui regresi linear masih kurang tepat, karena model biologi Schaefer berbentuk kuadratik, sehingga penyelesaiannya harus melalui proses kuadratik. Nilai <em>f<sub>msy</sub></em> dan <em>Y<sub>msy</sub></em> dari proses regresi linear memiliki nilai 1,40 dan 1,34 kali lebih rendah dari proses kuadratik. Berdasarkan kedua kurva dari kedua metode perhitungan koefisien <em>a</em> dan <em>b</em>, maka status pemanfaatan perikanan tuna madidihang diduga masih belum optimal. Sehingga berdasarkan proses regresi linear dan kuadratik, maka produksi maksimal tuna madidihang masih dapat ditingkatkan sampai dengan 664.037 dan 877.340 kg.</p><p><strong>Kata kunci:</strong>  Fungsi pertumbuhan populasi, Model biologi Schaefer, Status pemanfaatan Tuna madidihang</p>

RELEASE OF NON-EXCHANGEABLE SOIL POTASSIUM BY RESIN-EQUILIBRATION AND ITS SIGNIFICANCE FOR CROP GROWTH

1962 ◽  
Vol 42 (2) ◽  
pp. 266-272 ◽  
Author(s):  
T. E. Barber ◽  
B. C. Matthews
Keyword(s):  
Linear Regression ◽  
Ammonium Acetate ◽  
Cation Exchange Resin ◽  
Yield Response ◽  
Exchangeable Potassium ◽  
Quadratic Regression ◽  
Potassium Fertilizer ◽  
Crop Response ◽  
Soil Potassium ◽  
The Difference

The non-exchangeable potassium released by soil after equilibration with cation-exchange resin was determined by extraction of the mixture with neutral ammonium acetate at room temperature and compared with a similar extraction in the absence of resin. The difference obtained following a 2-day equilibration period was called moderately-available potassium.Simple linear regression of yield on exchangeable potassium or exchangeable plus moderately-available potassium accounted for only 16 and 27 per cent respectively of the variability in yield response of corn, wheat, oats and potatoes to potassium fertilizer in the field. Multiple linear regression of yield on exchangeable and moderately-available potassium accounted for an average of 37 per cent of the variation in crop response; but a multiple quadratic regression of Log (100-per cent yield) on exchangeable and moderately-available potassium accounted for an average of 56 per cent of the variability in Log (100-per cent yield). Multiple quadratic regression of absolute yield or per cent yield on exchangeable and moderately-available potassium accounted for 46 and 50 per cent, respectively, of the variability in crop response to potassium fertilizer.

scholarly journals SEBARAN HASIL TANGKAPAN MADIDIHANG (Thunnus albacares Bonnaterre, 1788) DI SAMUDERA HINDIA BAGIAN TIMUR

2015 ◽  
Vol 21 (2) ◽  
pp. 79
Author(s):  
Arief Wujdi ◽  
Ririk Kartika Sulistyaningsih ◽  
Fathur Rochman
Keyword(s):  
Good Condition ◽  
Monitoring Program ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Fishing Industry ◽  
Program Monitoring ◽  
Mentawai Islands ◽  
Management Measure ◽  
Tuna Fishery ◽  
Tuna Longline

<p>Ikan Madidihang (Thunnus albacares Bobbaterre, 1788) merupakan salah satu komoditaspenting bagi industri perikanan di Indonesia dimana hasil tangkapannya merupakan yang tertinggi dibandingkan jenis tuna lainnya. Saat ini, kondisi stok madidihang berada dalam kondisi yang baik. Namun, untuk menjaga kelangsungan pemantaatan stok ikan tuna, diperlukan upaya pengelolaan sumber daya tuna. Penelitian ini bertujuan untuk mengetahui distribusi laju tangkap madidihang di Samudera Hindia Bagian Timur. Pengumpulan data dilakukan oleh pemantau ilmiah pada kapal rawai tuna komersial yang berbasis di Benoa, Pelabuhanratu dan Bungus dari Agustus 2005 sampai Desember 2013; serta program monitoring pendaratan tuna yang berbasis di Benoa tahun 2010-2013. Hasil penelitian menunjukkan bahwa laju pancing bervariasi secara bulanan dan tahunan. Rata-rata bulanan laju pancing tertinggi terjadi pada Mei (0,17 ekor/100 pancing) dan terendah pada Februari (0,01 ekor/100 pancing), sedangkan rata-rata laju pancing tahunan tertinggi pada 2006 (0,11 ekor/100 pancing) dan terendah pada 2011 (0,06 ekor/100 pancing). Rata-rata laju pancing tahunan cenderung mengalami penurunan sebesar 29,48%/ tahun. Ikan madidihang tertangkap oleh rawai tuna Indonesia tersebar dari 0°-34° LS dan 76°-134° BT. Sebaran spasial laju pancing tertinggi berada di sekitar Kepulauan Mentawai dan selatan Jawa Timur hingga Nusa Tenggara.</p><p><br /><em>Yellowfin tuna (Thunnus albacares Bobbaterre, 1788) is one of the important commodity for the fishing industry in Indonesia because it has the highest catches compared with other tunas. Nowadays, the yellowfin stock is currently in good condition (not overfished and not subject to overfishing). However, management measure was required to support sustainability of tuna fishery. This study aims to determine the hook rate distribution of yellowfin tuna in the Eastern Indian Ocean. Data was obtained by scientific observers on commercial tuna longline vessels, mainly based in Benoa, Palabuhan Ratu and Bungus Fihing Port, from August 2005 to November 2013; </em><em>also monitoring program of tuna catches mainly landed in Benoa during 2010 to 2013. The results showed that the hook rate of yellowfin tuna was varied monthly and yearly. The highest of monthly </em><em>average CPUE occurred in May (0,17 fish/100 hooks) and the lowest were in February (0,01 fish/100 hooks), while the highest annually CPUE also occurred in 2006 (0,11 fish/100 hooks) and the lowest in 2011 (0,06 fish/100 hooks). CPUE also has declining with 29,48%/year. Distribution of yellowfin tuna caught by Indonesia tuna longline spreads from 0°-34° S dan 76°-134° E. The highest CPUE was around Mentawai islands and also in south coast of East Java to Nusa Tenggara.</em></p>

The Issue of Sustainability in Third World Food Production (The Distinguishedl Lecture)

1992 ◽  
Vol 31 (4I) ◽  
pp. 511-534
Author(s):  
Winfried Von Urff
Keyword(s):  
Developing Countries ◽  
Population Growth ◽  
Food Production ◽  
Third World ◽  
Total Population ◽  
Absolute Number ◽  
Comprehensive Analysis ◽  
World Food ◽  
The Absolute ◽  
The Difference

In spite of the fact that food production in developing countries doubled over the last 25 years undernutrition is still widely spread. At the beginning of the eighties, according to FAO, 335 to 494 million people in developing countries suffered from serious undernutrition the difference being due to different concepts to determine undernutrition on which scientist were unable to find a consensus.) Unfortunately there is no recent comprehensive analysis of the food situation comparable to those of previous World Food Surveys but it can be taken for sure that the absolute number of undernourished has increased. According to unofficial FAO sources a figure of 870 million was estimated for 1990 (22 percent of the total population in developing countries) using the same concept that led to the figure of 494 million in 1979-81 (23 percent of the total population in developing countries) which means that most probably the number of undernourished increased at a rate slightly less than population growth.

scholarly journals Feasibility study of assessing the Preclinical Alzheimer Cognitive Composite (PACC) score via videoconferencing

2021 ◽  
Author(s):  
Giulia Seghezzo ◽  
Yvonne Van Hoecke ◽  
Laura James ◽  
Donna Davoren ◽  
Elizabeth Williamson ◽  
...  
Keyword(s):  
Cognitive Impairment ◽  
Clinical Practice ◽  
Linear Regression ◽  
Multiple Linear Regression ◽  
Pearson Correlation ◽  
Cognitive Tests ◽  
Strong Positive Correlation ◽  
Pearson Correlation Coefficient ◽  
Face To Face ◽  
The Difference

Abstract Background The Preclinical Alzheimer Cognitive Composite (PACC) is a composite score which can detect the first signs of cognitive impairment, which can be of importance for research and clinical practice. It is designed to be administered in person; however, in-person assessments are costly, and are difficult during the current COVID-19 pandemic. Objective To assess the feasibility of performing the PACC assessment with videoconferencing, and to compare the validity of this remote PACC with the in-person PACC obtained previously. Methods Participants from the HEalth and Ageing Data IN the Game of football (HEADING) Study who had already undergone an in-person assessment were re-contacted and re-assessed remotely. The correlation between the two PACC scores was estimated. The difference between the two PACC scores was calculated and used in multiple linear regression to assess which variables were associated with a difference in PACC scores. Findings Of the 43 participants who were invited to this external study, 28 were re-assessed. The median duration in days between the in-person and the remote assessments was 236.5 days (7.9 months) (IQR 62.5). There was a strong positive correlation between the two assessments for the PACC score, with a Pearson correlation coefficient of 0·82 (95% CI 0·66, 0·98). The multiple linear regression found that the only predictor of the PACC difference was the time between assessments. Interpretation This study provides evidence on the feasibility of performing cognitive tests online, with the PACC tests being successfully administered through videoconferencing. This is relevant, especially during times when face-to-face assessments cannot be performed.

Ontogenetic changes in cutaneous and branchial ionocytes and morphology in yellowfin tuna (Thunnus albacares) larvae

2018 ◽  
Vol 189 (1) ◽  
pp. 81-95 ◽  
Author(s):  
Garfield T. Kwan ◽  
Jeanne B. Wexler ◽  
Nicholas C. Wegner ◽  
Martin Tresguerres
Keyword(s):  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Ontogenetic Changes

Extraction optimization and properties of collagen from yellowfin tuna (Thunnus albacares) dorsal skin

2008 ◽  
Vol 22 (5) ◽  
pp. 879-887 ◽  
Author(s):  
Jin-Wook Woo ◽  
Sung-Jae Yu ◽  
Seung-Mock Cho ◽  
Yang-Bong Lee ◽  
Seon-Bong Kim
Keyword(s):  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Dorsal Skin ◽  
Extraction Optimization

Exploitation and movements of yellowfin tuna (Thunnus albacares) and bigeye tuna (T. obesus) tagged in the north-western Coral Sea

1998 ◽  
Vol 49 (6) ◽  
pp. 475 ◽  
Author(s):  
John Hampton ◽  
John Gunn
Keyword(s):  
Seasonal Pattern ◽  
Yellowfin Tuna ◽  
Thunnus Albacares ◽  
Bigeye Tuna ◽  
Catch Per Unit Effort ◽  
The North ◽  
Coral Sea ◽  
Release Area ◽  
Seasonal Signal ◽  
North Western

Yellowfin tuna (Thunnus albacares) and bigeye tuna (T. obesus) were tagged and released in the north-western Coral Sea off northern Queensland in 1991 and 1992. Over the next five years, recaptures were reported by Australian longline vessels based in Cairns and fishing in the release area, and by industrial tuna fleets fishing in the adjacent western Pacific region, thus demonstrating clear links between the tuna stocks in these areas. Some southerly movements of yellowfin, in particular, further suggested links with stocks supporting the longline fishery in the south-eastern Australian Fishing Zone. Bigeye tuna tag returns and catch per unit effort by Cairns-based longliners showed a strong seasonal signal, peaking in mid year. Yellowfin tag-return data displayed a similar, but weaker, seasonal pattern. The data were analysed by use of tag-attrition models with seasonally variable catchability and with two assumptions regarding changes in targeting of the two species by longliners during the study. Under both assumptions, the local exploitation rates for yellowfin are low: about 0.07 in 1996. For bigeye, the local exploitation rate in 1996 may have been as high as 0.30, warranting a cautious approach to further fishery expansion in this area.

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