Size Selectivity of Diamond and Square Mesh Codends in Pelagic Herring Trawls: Only Small Herring Will Notice the Difference

1992 ◽  
Vol 49 (10) ◽  
pp. 2104-2117 ◽  
Author(s):  
Petri Suuronen ◽  
Russell B. Millar
Keyword(s):  
Relative Size ◽  
Mesh Size ◽  
The Other ◽  
Size Selectivity ◽  
The Difference ◽  
Catch Rates ◽  
Two Sides ◽  
High Catch

A twin codend trawl was fished in the northern Baltic to study the size selectivity of square mesh and diamond mesh codends of 36-mm nominal mesh size. For each codend, 15 hauls were completed with a small mesh (20 mm) codend deployed on the other side of the trawl. The relative size of the catches in the two sides of the trawl varied considerably from haul to haul (the separator section was not operating properly) and selection curves were estimated from each individual haul using a method that incorporated the differences in catching efficiency of the two sides. The length of 50% retention decreased with increased catch for both the diamond and square mesh codends, although in neither case was this relationship statistically significant. Selection curves fitted to the combined haul data were asymmetric. The square mesh codend retained significantly less small herring than the diamond mesh codend, and for larger herring the two codends had similar selectivity. In both codends, most escapes occurred at the front of the catch bulge, from the upper side of the codend. At high catch rates, mesh blockage was observed for several metres ahead of the catch bulge during the later part of the tow.

Introduction

2017 ◽  
Author(s):  
David M. Kaplan
Keyword(s):  
Climate Change ◽  
Environmental Impacts ◽  
Philosophy Of Technology ◽  
Environmental Issues ◽  
Environmental Philosophy ◽  
The Other ◽  
Natural Environments ◽  
The World ◽  
The Difference ◽  
Two Sides

Environmental philosophy and philosophy of technology have a lot in common. Both fields explore the positive and negative aspects of human modifications of the world. Both question the limits of technology in relation to natural environments, animals, plants, and food. Both examine if human making and doing is compatible with nature or wholly different from it. And both examine the difference between what is considered to be natural and artificial. Technology and the environment further intersect in a number of issues, such as climate change, sustainability, geo-engineering, and agriculture. The reason for the overlap is fundamental: Environmental issues inevitably involve technology, and technologies inevitably have environmental impacts. Technology and the environment are like two sides of the same coin: Each is fully understood only in relation to the other. Yet, despite the ample overlap of questions concerning technology and the environment, the two philosophical fields have developed in relative isolation from each other. Even when philosophers in each field address themselves to similar concerns, the research tends to be parallel rather than intersecting, and the literatures remain foreign to one another. These divergent paths are unfortunate. Philosophers from each field have a lot to contribute to the other....

scholarly journals On the difference of structure between the human membrana tympani and that of the elephant

1833 ◽  
Vol 2 ◽  
pp. 181-181
Keyword(s):  
Great Distance ◽  
The Other ◽  
Middle Line ◽  
Inner Surface ◽  
Oval Form ◽  
The Difference ◽  
Human Ear ◽  
Musical Sounds ◽  
Two Sides

In an elephant three weeks old, the membrana tympani was of an oval form, 1½ inch long, and 1 1/3 broad. The muscular fibres lie upon its inner surface, and terminate by an attachment to the point and two sides of the malleus, so that one portion of the fibres is short, and the other more than double their length. From this structure the elephant cannot adapt its ear to musical sounds in the same manner the human ear does; but in Sir Everard’s opinion, it is enabled by the long fibres to hear sounds at a great distance. In regard to musical sounds, high notes scarcely excite its attention, but it listens to the lower ones with apparent satisfaction. In neat cattle, and in the deer, the membrana tympani is oval, and the structure approximates to that in the elephant. In the horse, the hare, and the cat, the handle of the malleus lies in the middle line, so that the fibres on the two sides are equal, and the organ appears similarly constructed in the whole of the feline tribe.

The ‘teat order’ of suckling pigs: 3. Relation to competition within litters

1979 ◽  
Vol 92 (2) ◽  
pp. 257-261 ◽  
Author(s):  
D. Fraser ◽  
B. K. Thompson ◽  
D. K. Ferguson ◽  
R. L. Darroch
Keyword(s):  
Post Partum ◽  
Relative Size ◽  
Rank Correlation ◽  
The Other ◽  
Initial Weight ◽  
The Third ◽  
Weight Difference ◽  
The Difference ◽  
Selection Of

SummaryPiglets in litters, paired according to farrowing date, were redistributed during the first day after birth according to two schemes. In scheme AC–BD, one sow of the pair received the heaviest and the third heaviest quarters of the combined litters (based on weight post partum), while the other sow received the second heaviest and the lightest quarters. In scheme AB–CD, one sow received the heavier half, and the other the lighter half of the piglets. After 3 weeks under scheme AB–CD, the weight difference between the second and third quarters had become reversed, while under scheme AC–BD the difference was preserved. There was no evidence of a corresponding interaction in the selection of anterior or posterior teats. The rank correlation of the piglets' initial weight and suckling position was low for most sows. No marked differences were observed between fostered and unfostered piglets in the weight measures or suckling position. It is concluded that the growth of the piglets was influenced by the relative size of their litter-mates after redistribution, but that little of the effect could be explained by competition for the anterior teats.

scholarly journals Gillnet selectivity of the Indian oil sardine Sardinella longiceps fished in the Sea of Oman

2020 ◽  
Vol 24 ◽  
pp. 19
Author(s):  
Anesh Govender ◽  
Hamed Al-Oufi
Keyword(s):  
Relative Abundance ◽  
Mesh Size ◽  
Selection Function ◽  
Size Selectivity ◽  
Length Frequency ◽  
Frequency Distributions ◽  
Sardinella Longiceps ◽  
Log Normal ◽  
High Catch ◽  
Sea Of Oman

The size selectivity of drift gill-nets for Sardinella longiceps was investigated in the Sea of Oman using a range of nets between 3.3 and 5.7 cm stretched mesh size. All nets had a hanging ratio of 0.5. A total of 1 211 Indian oil sardines were caught in 5 experimental nets, the majority of which were retained by the 3.3, 3.8 and 4.5 cm mesh nets. Peak selectivity was reached at 14.9 cm FL for the 3.3 cm mesh size increasing to 16.9 cm for the 3.8 cm mesh size. The estimated and observed length frequency distributions were unimodal. A log-normal selection function indicated that the highest selectivity was obtained when the length class to mesh size (l:m ) ratio was 4.4. Sardinella longiceps's relative abundance was estimated to be the highest at 16.4 cm FL, with numbers decreasing beyond this peak. This would indicate that selectivity by gilling is optimal with a mesh size of 3.8 cm with nets having a hanging ratio of 0.5. This mesh size appears to satisfy two criteria:  high catch efficiency and protection of juveniles.

scholarly journals Estimating selectivity of experimental diamond (T0) and turned mesh (T90) codends in multi-species Mediterranean bottom trawl

2020 ◽  
Author(s):  
ANDREA PETETTA ◽  
BENT HERRMANN ◽  
MASSIMO VIRGILI ◽  
ROCCO De MARCO ◽  
GIOVANNI CANDUCI ◽  
...  
Keyword(s):  
Mesh Size ◽  
Bottom Trawl ◽  
Size Selectivity ◽  
Important Species ◽  
Trawl Fishery ◽  
The North ◽  
Common Squid ◽  
Commercially Important ◽  
The Mediterranean ◽  
The Difference

The effect of shifting from a diamond mesh codend (T0) to a 90° turned mesh codend (T90) on the size selectivity of seven commercially important species in the Mediterranean bottom trawl fishery was evaluated. During sea trials conducted in the north-western Adriatic, two experimental codends made of 54 mm nominal mesh size netting that differed only in mesh configuration were alternately mounted on the same trawl. Overall, the size selectivity was significantly improved for all the species analysed, shifting from T0 to T90. The difference in the average expected L50values between T90 and T0 was particularly marked in European hake (Merluccius merluccius, 21.26 vs 11.26 cm total length), common squid (Loligo vulgaris, 12.06 vs 7.88 cm mantle length) and mantis shrimp (Squilla mantis, 20.78 vs 13.35 mm carapace length). Both codends had an excessive size selectivity especially for red mullet (Mullus barbatus), Mediterranean horse mackerel (Trachurus mediterraneus) and whiting (Merlangius merlangus), thus involving a commercial loss. These findings demonstrate the efficiency of the T90 codend tested at excluding undersized specimens, especially of hake, whose average L50was above the minimum conservation reference size of 20 cm. The adoption of this practical and inexpensive solution could help improve the management of the demersal resources targeted by the Mediterranean bottom trawl fishery.

Enhancement of ADP-induced Platelet Aggregation by Adrenaline in Vivo and Its Prevention

1973 ◽  
Vol 29 (02) ◽  
pp. 490-498 ◽  
Author(s):  
Hiroh Yamazaki ◽  
Itsuro Kobayashi ◽  
Tadahiro Sano ◽  
Takio Shimamoto
Keyword(s):  
Platelet Count ◽  
Platelet Aggregation ◽  
Platelet Rich Plasma ◽  
The Other ◽  
Endothelial Surface ◽  
Important Interaction ◽  
Blood Coagulability ◽  
The Difference

SummaryThe authors previously reported a transient decrease in adhesive platelet count and an enhancement of blood coagulability after administration of a small amount of adrenaline (0.1-1 µg per Kg, i. v.) in man and rabbit. In such circumstances, the sensitivity of platelets to aggregation induced by ADP was studied by an optical density method. Five minutes after i. v. injection of 1 µg per Kg of adrenaline in 10 rabbits, intensity of platelet aggregation increased to 115.1 ± 4.9% (mean ± S. E.) by 10∼5 molar, 121.8 ± 7.8% by 3 × 10-6 molar and 129.4 ± 12.8% of the value before the injection by 10”6 molar ADP. The difference was statistically significant (P<0.01-0.05). The above change was not observed in each group of rabbits injected with saline, 1 µg per Kg of 1-noradrenaline or 0.1 and 10 µg per Kg of adrenaline. Also, it was prevented by oral administration of 10 mg per Kg of phenoxybenzamine or propranolol or aspirin or pyridinolcarbamate 3 hours before the challenge. On the other hand, the enhancement of ADP-induced platelet aggregation was not observed in vitro, when 10-5 or 3 × 10-6 molar and 129.4 ± 12.8% of the value before 10∼6 molar ADP was added to citrated platelet rich plasma (CPRP) of rabbit after incubation at 37°C for 30 second with 0.01, 0.1, 1, 10 or 100 µg per ml of adrenaline or noradrenaline. These results suggest an important interaction between endothelial surface and platelets in connection with the enhancement of ADP-induced platelet aggregation by adrenaline in vivo.

Eurasian "Theory of Economy Management" as an Organic Part of the Russian Economic School

2003 ◽  
pp. 95-110
Author(s):  
M. Voeykov
Keyword(s):  
Economic Development ◽  
Theoretical Model ◽  
Initial Step ◽  
State Regulation ◽  
Soviet Economy ◽  
The Other ◽  
Large Share ◽  
Organic Part ◽  
Two Sides ◽  
Enterprise Activity

The original version of "the theory of economy management", developed in the 1920s by Russian economists-emigrants who called themselves "Eurasians" (N. Trubetskoy, P. Savitskiy, etc.) is analyzed in the article. They considered this theory to be the basis of the original Russia's way of economic development. The Eurasian theory of economy management focuses on two sides of enterprise activity: managerial as well as social and moral. The Eurasians accepted the Soviet economy with the large share of state regulation as the initial step of development. On the other hand they paid much attention to the private sector activity. Eurasians developed a theoretical model of the mixed economy which can be attributed as the Russian economic school.

Energy Approximation

2017 ◽  
Author(s):  
Philip Isett
Keyword(s):  
Main Lemma ◽  
The Other ◽  
Coarse Scale ◽  
Continuous Solutions ◽  
Material Derivative ◽  
Energy Variation ◽  
Energy Approximation ◽  
The Difference ◽  
Derivatives Of

This chapter presents the equations and calculations for energy approximation. It establishes the estimates (261) and (262) of the Main Lemma (10.1) for continuous solutions; these estimates state that we are able to accurately prescribe the energy that the correction adds to the solution, as well as bound the difference between the time derivatives of these two quantities. The chapter also introduces the proposition for prescribing energy, followed by the relevant computations. Each integral contributing to the other term can be estimated. Another proposition for estimating control over the rate of energy variation is given. Finally, the coarse scale material derivative is considered.

Pengaruh Unsur Budaya Lokal dalam Ungkapan Berbahasa Perancis

Metahumaniora ◽  
2017 ◽  
Vol 7 (3) ◽  
pp. 378
Author(s):  
Vincentia Tri Handayani
Keyword(s):  
Mental Representation ◽  
Cultural Context ◽  
Oral Tradition ◽  
Minimal Element ◽  
The Other ◽  
Local Culture ◽  
Community Groups ◽  
Cultural Community ◽  
The Difference ◽  
Complex Words

AbstrakFolklor yang menghasilkan tradisi lisan merupakan perwujudan budaya yang lahirdari pengalaman kelompok masyarakat. Salah satu bentuk tradisi lisan adalah ungkapan yangmengandung unsur budaya lokal dalam konstruksinya yang tidak dimiliki budaya lainnya.Ungkapan idiomatis memberikan warna pada bahasa melalui penggambaran mental. Dalambahasa Perancis, ungkapan dapat berupa locution dan expression. Perbedaan motif acuansuatu ungkapan dapat terlihat dari pengaruh budaya masyarakat pengguna bahasa. Sebuahleksem tidak selalu didefinisikan melalui unsur minimal, tidak juga melalui kata-kata,baik kata dasar atau kata kompleks, namun dapat melalui kata-kata beku yang maknanyatetap. Hubungan analogis dari makna tambahan yang ada pada suatu leksem muncul dariidentifikasi semem yang sama. Semem tersebut mengarah pada term yang diasosiasikan danyang diperkaya melalui konteks (dalam ungkapan berhubungan dengan konteks budaya).Kata kunci: folklor, ungkapan, struktur, makna idiomatis, kebudayaanAbstractFolklore which produces the oral tradition is a cultural manifestation born out theexperience of community groups. One form of the oral tradition is a phrase that containsthe elements of local culture in its construction that is not owned the other culture. Theidiomatic phrase gives the color to the language through the mental representation. InFrench, the expression can consist of locution and expression. The difference motivesreference of an expression can be seen from the influence of the cultural community thelanguage users. A lexeme is not always defined through a minimal element, nor throughwords, either basic or complex words, but can be through the frost words whose meaningsare fixed. The analogical connection of the additional meanings is on a lexeme arises fromthe identification of the same meaning. The meaning ‘semem’ leads to the associated termsand which are enriched through the context (in idiom related to the cultural context).Keywords : folklore, idioms, structure, idiom meaning, cultureI PENDAHULUAN

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