A critical review of methods of studying fish feeding based on analysis of stomach contents: application to elasmobranch fishes

1997 ◽  
Vol 54 (3) ◽  
pp. 726-738 ◽  
Author(s):  
E Cortés
Keyword(s):  
Stomach Content ◽  
Critical Review ◽  
Graphical Representation ◽  
Statistical Tests ◽  
Rank Correlation ◽  
Stomach Contents ◽  
Real Data ◽  
Daily Ration ◽  
Fish Feeding ◽  
Elasmobranch Fishes

Using real data sets of elasmobranch fishes as examples, this paper presents a critical review of selected methods and statistical approaches used in fish feeding studies and makes recommendations on the application of such methodology. The percent index of relative importance is proposed as a standardized measure in dietary analyses, and a three-dimensional graphical representation of the diet is introduced. Multiway contingency table (log-linear) analysis is recommended to test for dietary variations. Caution is advised when using rank correlation to study dietary overlap and parametric tests when stomach content data do not satisfy parametric assumptions. Sampling gear type, experimental design, and statistical tests can affect results on diel feeding chronology, and stomach content weights do not suffice to interpret diel feeding chronology. On the basis of sampling requirements and model assumptions, the Diana and Olson-Mullen methods appear to be the most appropriate approaches for estimating daily ration in sharks. Use of resampling techniques is highly desirable because they provide a measure of the error in daily ration estimates. Using several criteria to evaluate the best-fitting model of gastric evacuation in fishes is also strongly advocated. Overall, increased consolidation of methods and analyses is recommended to facilitate comparative studies.

Efektivitas Komunikasi Pendamping Corporate Social Responsibility (CSR)

2020 ◽  
Vol 4 (6) ◽  
pp. 894
Author(s):  
Yara Falmira Dianira
Keyword(s):  
Statistical Tests ◽  
Rank Correlation ◽  
Communication Effectiveness ◽  
Message Content ◽  
Sources Of Information ◽  
Source Information ◽  
Spearman Rank Correlation ◽  
Level Of Understanding ◽  
Corporate Social

ABSTRACT An important factor for the success of a CSR program is effective communication. Communication will be effective if it has an impact. If the information is conveyed based on the needs, then the communication will be effective. This study aims to analyze the factors which are related to the effectiveness of CSR communication. This study used a census method to approach 37 participants who received CSR programs. The Data analysis used the Spearman rank correlation for the statistical tests. The results showed that there was a correlation between factors that have the strength of CSR companion communication (level of attractiveness of the companion, quality of message content, and sources of information) which have real communication at the level of understanding of the participants of the Kertajaya Creative Destination (KCD) CSR program. In addition, there is a real correlation the factors that have the strength of CSR companion communication (the level of credibility of the companion, the source information, and the level of the recipient) and having communication at the level of attitudes of participants in the Kertajaya Creative Destination (KCD) CSR program. However, there is no real correlation between CSR companion communication factors and participant actions.Keywords :communication effectiveness, CSR, elements of communication. ABSTRAK Faktor penting dari keberhasilan program CSR adalah komunikasi yang efektif. Komunikasi dikatakan efektif jika menimbulkan dampak. Bila informasi tersampaikan sesuai dengan kebutuhan, maka komunikasi yang dijalankan efektif. Penelitian ini bertujuan untuk menganalisis efektivitas komunikasi pendamping CSR. Penelitian ini menggunakan pendekatan sensus terhadap 37 orang peserta penerima program CSR. Analisis data menggunakan uji statistik korelasi rank Spearman. Hasil penelitian menunjukkan bahwa terdapat hubungan nyata antara faktor efektivitas komunikasi pendamping CSR (derajat daya tarik pendamping, kualaitas isi pesan, dan sumber informasi)  dengan efektivitas komunikasi pada tingkat pemahaman peserta program CSR Kertajaya Creative Destination (KCD). Selain itu, terdapat hubungan nyata antara faktor efektivitas komunikasi pendamping CSR (tingkat kredibilitas pendamping, sumber informasi, dan tingkat penerima) dengan efektivitas komunikasi pada tingkat sikap peserta program CSR Kertajaya Creative Destination (KCD). Namun, tidak terdapat hubungan nyata antara faktor efektivitas komunikasi pendamping CSR dengan tindakan peserta. Kata Kunci : CSR, efektivitas komunikasi, unsur-unsur komunikasi.

Variation terminologique en francophonie. Élaboration d’un modèle d’analyse des facteurs d’implantation terminologique

2017 ◽  
Author(s):  
◽  
Minchai Kim
Keyword(s):  
Correlation Analysis ◽  
Statistical Tests ◽  
Rank Correlation ◽  
Decisive Role ◽  
European Countries ◽  
French Language ◽  
Hypothetical Model ◽  
Moderator Variables ◽  
Spearman’S Rank Correlation ◽  
Significant Difference

Our research aims to elucidate the factors that influence the terminological implantation of a term by proposing a new typology of those factors with a method revealing how their mechanism causes terminological variation in French-language ICT. We accomplish this through an analysis of four Francophone communities: France, Quebec, Belgium, and Switzerland. After establishing a new typology, which encompasses the terminological, socio-terminological, psycho-terminological, and extra-terminological factors, we propose a hypothetical model of their mechanism by introducing three statistical concepts—dependent, independent, and moderator variables—to elucidate these factors’ relationships. We verify our model in two steps. First, for the analysis of terminological and socio- terminological factors, we examine the relations between each factor and terminological implantation of 256 French ICT terms. For this, we begin by coding the terms according to a criterion established for each factor. We then carry out a correlation analysis with Spearman’s rank correlation. Second, we analyse the psycho-terminological and extra-terminological factors with statistical tests on the answers to our questionnaire, which show significant differences between these four linguistic communities. Our analysis confirms a significant difference between the three European countries and Quebec in the mechanism of the terminological implantation factors and we conclude that the psycho-terminological and extra-terminological factors play a decisive role in this difference, which we identify as diatopic.

scholarly journals Stomach Content of Tillapia zilli and Oreochromis nilocticus from Wanzun River, Lavun Local Government, Niger State Nigeria

2021 ◽  
pp. 15-20
Author(s):  
Y. M. Mohammed ◽  
M. D. Abubakar ◽  
A. M. Muhammad ◽  
A. S. Muhammad ◽  
B. L. Umar ◽  
...  
Keyword(s):  
Fish Species ◽  
Stomach Content ◽  
Stomach Contents ◽  
Empty Stomach ◽  
Plant Materials ◽  
Individual Fish ◽  
Fish Samples ◽  
Commercially Important ◽  
Fish Remains ◽  
The One

This study was conducted to investigate the stomach contents of two commercially important fish species (Tilapia zilli and Oreochromis nilocticus)  from Wanzun River, Northcentral Nigeria using frequency of occurrence and volumetric methods between January to April 2019. Fish samples were collected monthly with help of Fishermen using various fishing nets and traps. One hundred (100) individual fish of each species were collected and their stomach contents were examined. The results obtained expressed in mean percentage indicated that out of the one hundred (100) individual fish of each species examined,Twelve (12%) fish had an empty stomach contents in Tilapia zilli, and out of the 100 samples examined, Seventeen (17%) fish had an empty stomach content in Oreochromis nilocticus. The stomach contents of both Tilapia zilli and Oreochromis nilocticus consist of detritus, insects, fish remains. Algae/protozoans plant materials and molluscs. Both fish species are omnivorous feeders and occupy the same ecological niche.The study reveals the importance of algae, fish, insects and plant materials as food for fishes and they form important part in the diet of the species examined.

scholarly journals Probability Models and Statistical Tests for Extreme Precipitation Based on Generalized Negative Binomial Distributions

Mathematics ◽  
2020 ◽  
Vol 8 (4) ◽  
pp. 604 ◽  
Author(s):  
Victor Korolev ◽  
Andrey Gorshenin
Keyword(s):  
Negative Binomial ◽  
Daily Precipitation ◽  
Global Climate ◽  
Statistical Tests ◽  
Real Data ◽  
Total Precipitation ◽  
Climate Trends ◽  
Probability Models ◽  
Precipitation Volume ◽  
Precipitation Total

Mathematical models are proposed for statistical regularities of maximum daily precipitation within a wet period and total precipitation volume per wet period. The proposed models are based on the generalized negative binomial (GNB) distribution of the duration of a wet period. The GNB distribution is a mixed Poisson distribution, the mixing distribution being generalized gamma (GG). The GNB distribution demonstrates excellent fit with real data of durations of wet periods measured in days. By means of limit theorems for statistics constructed from samples with random sizes having the GNB distribution, asymptotic approximations are proposed for the distributions of maximum daily precipitation volume within a wet period and total precipitation volume for a wet period. It is shown that the exponent power parameter in the mixing GG distribution matches slow global climate trends. The bounds for the accuracy of the proposed approximations are presented. Several tests for daily precipitation, total precipitation volume and precipitation intensities to be abnormally extremal are proposed and compared to the traditional PoT-method. The results of the application of this test to real data are presented.

Simultaneous inversion for crustal thickness and anisotropy by multiphase splitting analysis of receiver functions

2020 ◽  
Vol 223 (3) ◽  
pp. 2009-2026
Author(s):  
Frederik Link ◽  
Georg Rümpker ◽  
Ayoub Kaviani
Keyword(s):  
Statistical Tests ◽  
Real Data ◽  
Crustal Thickness ◽  
Receiver Functions ◽  
S Wave ◽  
Arrival Times ◽  
Simultaneous Inversion ◽  
Correction Scheme ◽  
Converted Phases ◽  
Two Phases

SUMMARY We present a technique to derive robust estimates for the crustal thickness and elastic properties, including anisotropy, from shear wave splitting of converted phases in receiver functions. We combine stacking procedures with a correction scheme for the splitting effect of the crustal converted Ps-phase and its first reverberation, the PpPs-phase, where we also allow for a predefined dipping Moho. The incorporation of two phases stabilizes the analysis procedure and allows to simultaneously solve for the crustal thickness, the ratio of average P- to S-wave velocities, the percentage of anisotropy and the fast-axis direction. The stacking is based on arrival times and polarizations computed using a ray-based algorithm. Synthetic tests show the robustness of the technique and its applicability to tectonic settings where dip of the Moho is significant. These tests also demonstrate that the effects of a dipping layer boundary may overprint a possible anisotropic signature. To constrain the uncertainty of our results we perform statistical tests based on a bootstrapping approach. We distinguish between different model classes by comparing the coherency of the stacked amplitudes after moveout correction. We apply the new technique to real-data examples from different tectonic regimes and show that coherency of the stacked receiver functions can be improved, when anisotropy and a dipping Moho are included in the analysis. The examples underline the advantages of statistical analyses when dealing with stacking procedures and potentially ambiguous solutions.

scholarly journals The Use of Statistical Tests to Calibrate the Black-Scholes Asset Dynamics Model Applied to Pricing Options with Uncertain Volatility

2012 ◽  
Vol 2012 ◽  
pp. 1-20 ◽  
Author(s):  
Lorella Fatone ◽  
Francesca Mariani ◽  
Maria Cristina Recchioni ◽  
Francesco Zirilli
Keyword(s):  
Statistical Tests ◽  
Statistical Significance ◽  
Asset Price ◽  
Real Data ◽  
Dynamics Model ◽  
Stochastic Dynamical Systems ◽  
Pricing Options ◽  
Black Scholes ◽  
Uncertain Volatility ◽  
Two Parameters

A new method for calibrating the Black-Scholes asset price dynamics model is proposed. The data used to test the calibration problem included observations of asset prices over a finite set of (known) equispaced discrete time values. Statistical tests were used to estimate the statistical significance of the two parameters of the Black-Scholes model: the volatility and the drift. The effects of these estimates on the option pricing problem were investigated. In particular, the pricing of an option with uncertain volatility in the Black-Scholes framework was revisited, and a statistical significance was associated with the price intervals determined using the Black-Scholes-Barenblatt equations. Numerical experiments involving synthetic and real data were presented. The real data considered were the daily closing values of the S&P500 index and the associated European call and put option prices in the year 2005. The method proposed here for calibrating the Black-Scholes dynamics model could be extended to other science and engineering models that may be expressed in terms of stochastic dynamical systems.

Diel variation of stomach contents of North Sea cod (Gadus morhua) during a 24-h fishing survey: an analysis using generalized additive models

2000 ◽  
Vol 57 (12) ◽  
pp. 2363-2367 ◽  
Author(s):  
Sara A Adlerstein ◽  
Henny C Welleman
Keyword(s):  
North Sea ◽  
Stomach Content ◽  
Gadus Morhua ◽  
Generalized Additive Models ◽  
Stomach Contents ◽  
Additive Models ◽  
Large Prey ◽  
Diel Variation ◽  
The North ◽  
The North Sea

Results show that the weight of cod (Gadus morhua) stomach contents sampled in the North Sea varies significantly within 24 h. To determine whether feeding varied with time, over 1100 cod stomachs were collected around the clock between 7 and 18 May 1984 in two areas in the central North Sea thought to be representative for feeding studies. Here we investigate temporal feeding patterns based on the analysis of stomach-content data, using generalized additive models (GAMs). Results show significant variation of content weight and indicate morning and evening peaks. The relative peak importance differed between and within areas. We propose that differences are due to diet composition, namely, prey size and diel availability. Cod fed primarily on molluscs, mainly ocean quahog (Cyprina islandica), crustaceans, sandeels (Ammodytes spp.), haddock (Melanogrammus aeglefinus), herring (Clupea harrengus), and several flatfish species. In one area, the diet was dominated by fish, relatively large prey that perform diel vertical migration, and in the other by invertebrates, smaller prey that are digested faster. The diel pattern was more pronounced where invertebrate prey were dominant. Generalisation of results and implications for predation-mortality estimates based on data from the North Sea Stomach Content Database, used to implement multispecies models in the region, are discussed.

Sources of variability and comparability between salmonid stomach contents and isotopic analyses: study design lessons and recommendations

2011 ◽  
Vol 68 (1) ◽  
pp. 137-151 ◽  
Author(s):  
Mark R. Vinson ◽  
Phaedra Budy
Keyword(s):  
Stable Isotope ◽  
Study Design ◽  
Stomach Content ◽  
Stomach Contents ◽  
Stomach Content Analysis ◽  
Diet Overlap ◽  
Target Species ◽  
Relative Information ◽  
Isotopic Analyses ◽  
Diet Analyses

We compared sources of variability and cost in paired stomach content and stable isotope samples from three salmonid species collected in September 2001–2005 and describe the relative information provided by each method in terms of measuring diet overlap and food web study design. Based on diet analyses, diet overlap among brown trout, rainbow trout, and mountain whitefish was high, and we observed little variation in diets among years. In contrast, for sample sizes n ≥ 25, 95% confidence interval (CI) around mean δ15Ν and δ13C for the three target species did not overlap, and species, year, and fish size effects were significantly different, implying that these species likely consumed similar prey but in different proportions. Stable isotope processing costs were US$12 per sample, while stomach content analysis costs averaged US$25.49 ± $2.91 (95% CI) and ranged from US$1.50 for an empty stomach to US$291.50 for a sample with 2330 items. Precision in both δ15Ν and δ13C and mean diet overlap values based on stomach contents increased considerably up to a sample size of n = 10 and plateaued around n = 25, with little further increase in precision.

Daily ration and feeding activity of juvenile hake in the central Mediterranean Sea

2008 ◽  
Vol 88 (7) ◽  
pp. 1493-1501 ◽  
Author(s):  
P. Carpentieri ◽  
F. Colloca ◽  
G. Ardizzone
Keyword(s):  
Mediterranean Sea ◽  
Feeding Activity ◽  
Central Italy ◽  
Stomach Contents ◽  
Western Coast ◽  
Daily Ration ◽  
Gastric Evacuation ◽  
Central Mediterranean ◽  
Migratory Activity ◽  
Central Mediterranean Sea

We investigated daily ration, feeding rhythms and gastric evacuation rates of juvenile (<16 cm total length) European hake Merluccius merluccius, using stomach samples collected during four 24-hour trawl surveys carried out in 2001–2002 on the continental shelf-break (from 120 m to 160 m in depth) off the western coast of central Italy (central Mediterranean Sea). In each survey 8 hauls of 30 minutes were performed every three hours throughout the 24-hour period to cover the entire diel cycle. Diet of juvenile hake was mostly composed of the euphausiid Nyctiphanes couchii, showing a peak in stomach contents during early morning followed by a daytime decrease. Fullness index (%FI) was generally higher during sunrise when migratory activity ceased and juvenile hake return to the bottom after feeding. Concerning the hake abundance the highest density value was obtained in May during the recruitment period.Two independent daily ration estimates were produced. First, an empirical attempt to estimate the daily amount of food consumed was obtained by back-calculating the fresh weight of euphausiid prey ingested by juvenile hake. Estimated values ranged from 4.96–5.89% body wet weight (%BW). Second, the daily ration was computed applying the exponential gastric evacuation models proposed by Elliot & Persson (1978) and Eggers (1979). Daily ration values obtained using these consumption models produced a considerable (15–20%) underestimation of consumption rate for juvenile hake.

scholarly journals PERSEPSI PETANI ANGGOTA P3A TERHADAP PENGELOLAAN IRIGASI USAHATANI PADI SAWAH DI KELURAHAN MARGODADI KECAMATAN METRO SELATAN KOTA METRO

2020 ◽  
Vol 8 (2) ◽  
pp. 359
Author(s):  
Nadia Ulfa Armia ◽  
Dame Trully Gultom ◽  
Irwan Effendi
Keyword(s):  
Formal Education ◽  
Statistical Tests ◽  
Irrigation Management ◽  
Rank Correlation ◽  
Survey Method ◽  
Rice Farming ◽  
Spearman Rank Correlation ◽  
Spearman Rank ◽  
Nonparametric Statistical ◽  
Land Size

This study aims to determine the perceptions of P3A member farmers on irrigation management of rice farming and to analyze the factors related to the perception of the farmers on irrigation management of rice farming. This research was carried out in Margodadi Village South Metro Subdistrict Metro Regency with 65 respondents from P3A members participating in P3A activities. Data were collected through a survey method and analyzed descriptively and using nonparametric statistical tests of Spearman Rank Correlation. The results of this study indicated that the perceptions of P3A member farmers on irrigation management of rice farming is in the medium category. Factors related to the perceptions of P3A member farmers on irrigation management of rice farming are formal education, motivation, needs, rice farming experience, knowledge, social environment, support of related agencies, and land size. Meanwhile, unrelated factors are age and number of dependents.Key words: field irrigation management, perceptions, P3A

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