How Reliable are Growth Back-Calculations Based on Otoliths?

1990 ◽  
Vol 47 (11) ◽  
pp. 2219-2227 ◽  
Author(s):  
Steven E. Campana
Keyword(s):  
Somatic Growth ◽  
Growth Effect ◽  
Fish Otolith ◽  
Stochastic Error ◽  
Individual Fish ◽  
Back Calculation ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Slow Growing

Growth back-calculations from otoliths assume that the relationship between fish and otolith length is linear through time. The final (or observed) individual fish-otolith ratios are then combined to prepare a fish-otolith regression for the population, upon which the subsequent back-calculations are based. However, recent studies have demonstrated that the fish:otolith size ratio varies systematically with somatic growth rate, resulting in relatively large otoliths in slow-growing fish. Such a growth effect will result in a fitted fish-otolith regression which differs significantly from that of the mean of the individual fish-otolith slopes. Fraser–Lee growth back-calculations made from such a regression consistently underestimate previous lengths at age. The bias may explain the apparent ubiquity of Lee's phenomenon. Back-calculation bias was eliminated through use of an algorithm defining individual fish-otolith trajectories and a biologically determined, rather than a statistically estimated, intercept. Adaptations of the biological intercept back-calculations procedure accurately predicted previous lengths in the presence of both stochastic error and time-varying growth rates. When used to reevaluate some published back-calculations, the biological intercept procedure resulted in more accurate values than those previously estimated, and reduced or eliminated the presence of Lee's phenomenon.

scholarly journals Sex-specific growth effects in protogynous hermaphrodites

2004 ◽  
Vol 61 (3) ◽  
pp. 323-327 ◽  
Author(s):  
Philip L Munday ◽  
Alyson L Hodges ◽  
J Howard Choat ◽  
Nick Gust
Keyword(s):  
Specific Growth ◽  
Somatic Growth ◽  
Early Life History ◽  
Age Effect ◽  
Growth Effect ◽  
Otolith Growth ◽  
Precise Relationship ◽  
Size At Age ◽  
The Relationship ◽  
Slow Growing

We demonstrate sex-specific decoupling of otolith growth and somatic growth in two species of protogynous parrotfishes, Scarus frenatus and Chlorurus sordidus. Otoliths of both species increased in size consistently through life, even though somatic growth rate decreased with age (age effect). Furthermore, in S. frenatus, otoliths from terminal males were smaller than otoliths from females, despite males being larger than females of the same age. This demonstrates the presence of a sex-specific growth effect, where otoliths of fast-growing individuals (males) are smaller than otoliths of slow-growing individuals (females). The sex-specific growth effect for S. frenatus was most pronounced during the early life history, which suggests that only the fastest-growing females change sex to male. A sex-specific growth effect was also evident in C. sordidus, although it was not statistically significant because of greater variation in the otolith size of terminal males of this species. Our results demonstrate that the relationship between otolith and somatic growth can vary dramatically between the sexes. This will make it difficult to back-calculate size at age in protogynous species, or to conduct sex-specific back-calculations in gonochoristic species, unless the precise relationship between otolith and somatic growth is known for each sex.

Comparison of Otolith-Based Back-Calculation Methods to Determine Individual Growth Histories of Larval Striped Bass, Morone saxatilis

1992 ◽  
Vol 49 (7) ◽  
pp. 1439-1454 ◽  
Author(s):  
David H. Secor ◽  
John Mark Dean
Keyword(s):  
Striped Bass ◽  
Somatic Growth ◽  
Morone Saxatilis ◽  
Growth Effect ◽  
Individual Growth ◽  
Quadratic Model ◽  
Calculation Methods ◽  
Otolith Growth ◽  
Experimental Proof ◽  
Back Calculation

In rearing studies on 6- to 22-d-old larval striped bass, Morone saxatilis, we applied several back-calculation methods to known-growth larvae. A growth effect occurred on otolith diameter – standard length relationships, where slower growing larvae had relatively larger otoliths. Otolith growth was less affected by feeding regime than was somatic growth. Due to the conservative nature of otolith growth, proportional based (Biological Intercept Method) and simple linear regression methods linearized somatic growth transitions and did not estimate periods of negative growth. A quadratic regression method which used age as an additional predictor resulted in the accurate back-calculation of size at age in all groups of laboratory-reared larvae. However, when model coefficients were applied to a test population of pond-reared larvae, the quadratic model performed poorly. While differences in relative otolith size between pond- and laboratory-reared larvae could be ascribed to a temperature effect, the inability to apply the model also indicates a problem specific to regression-based methods. Theoretical rationale and experimental proof provided evidence for the inclusion of age in back-calculation models, but parameterization will have to occur for each field application.

Study of Speed-Flow Relationships on Individual Freeway Lanes

1997 ◽  
Vol 1591 (1) ◽  
pp. 7-13 ◽  
Author(s):  
V. F. Hurdle ◽  
Mark I. Merlo ◽  
Doug Robertson
Keyword(s):  
Practical Interest ◽  
Linear Functions ◽  
Highway Capacity ◽  
Highway Capacity Manual ◽  
Speed Flow ◽  
High Flows ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Very High

Many researchers have examined the form of the relationship between speed and flow on freeways. However, these researchers have concentrated on relationships for the freeway as a whole instead of on individual lanes. In this study, the relationship was examined for each of the three lanes at two locations on Highway 401 in metropolitan Toronto. It proved possible to accurately describe the mean speed in each lane with simple linear functions over the range of flows of most practical interest. Cubic functions provided comparable results over a wider range of flows, but it appears unlikely that the very high and very low flows are of sufficient interest to justify the added complexity. When an attempt was made to examine the relationship between speed and flow for the entire roadway, the linear functions were not adequate, but cubic functions performed reasonably well. However, the details of the full roadway curves are quite different from those of the curves described in the 1994 Highway Capacity Manual. In particular, the curves described in the manual are much steeper than the Highway 401 curves at high flows, implying a much more rapid loss of performance as flow approaches capacity than was observed. The full roadway curves are also surprisingly different from the curves for the individual lanes.

Monitoring Training Volume Through Maximal Number of Repetitions or Velocity-Based Approach

2020 ◽  
pp. 1-8
Author(s):  
Miguel Sánchez-Moreno ◽  
Gonçalo Rendeiro-Pinho ◽  
Pedro V. Mil-Homens ◽  
Fernando Pareja-Blanco
Keyword(s):  
Coefficient Of Variation ◽  
Bench Press ◽  
Interindividual Variability ◽  
Load Condition ◽  
Velocity Relationship ◽  
The Mean ◽  
Monitoring Training ◽  
The Individual ◽  
The Relationship ◽  
Level Of Effort

Purpose: This study aimed (1) to analyze the interindividual variability in the maximal number of repetitions (MNR) performed against a given relative load (percentage of 1-repetition maximum [%1RM]) and (2) to examine the relationship between the velocity loss (VL) magnitude and the percentage of completed repetitions with regard to the MNR (%Rep), when the %1RM is based on individual load–velocity relationships. Methods: Following an assessment of 1RM strength and individual load–velocity relationships, 14 resistance-trained men completed 5 MNR tests against loads of 50%, 60%, 70%, 80%, and 90% 1RM in the Smith machine bench-press exercise. The relative loads were determined from the individual load–velocity relationship. Results: Individual relationships between load and velocity displayed coefficients of determination (R2) ranging from .986 to .998. The MNR showed an interindividual coefficient of variation ranging from 8.6% to 33.1%, increasing as the %1RM increased. The relationship between %Rep and the magnitude of VL showed a general R2 of .92 to .94 between 50% and 80% 1RM, which decreased to .80 for 90% 1RM. The mean individual R2 values were between .97 and .99 for all loading conditions. The %Rep when a given percentage of VL was reached showed interindividual coefficient of variation values ranging from 5% to 20%, decreasing as the %Rep increased in each load condition. Conclusions: Setting a number of repetitions had acceptable interindividual variability, with moderate relative loads being adjusted based on the individual load–velocity relationship. However, to provide a more homogeneous level of effort between athletes, the VL approach should be considered, mainly when using individual VL–%Rep relationships.

A Behavioral Process Approach to Information Acquisition in Nondurable Purchasing

1978 ◽  
Vol 15 (4) ◽  
pp. 532-544 ◽  
Author(s):  
Jacob Jacoby ◽  
Robert W. Chestnut ◽  
William A. Fisher
Keyword(s):  
Information Search ◽  
Information Acquisition ◽  
Consumer Information ◽  
Behavioral Process ◽  
The Mean ◽  
The Individual ◽  
Attitudinal Brand Loyalty ◽  
Available Information ◽  
Relationship Of ◽  
The Relationship

A behavioral process method was used to explore the relationship of individual difference factors to consumer information acquisition behavior. Findings included: (1) the mean proportion of available information actually acquired was 2%, and (2) information search was concentrated on six of the 35 available information dimensions; increased information acquisition was related (3) positively to the product's importance for the individual, (4) positively to being an optimizer rather than a satisficer, (5) positively to high amounts of past purchasing experience with the product, and (6) negatively to attitudinal brand loyalty.

scholarly journals Caregiver distress associated with behavioral and psychological symptoms in mild Alzheimer's disease

2010 ◽  
Vol 4 (3) ◽  
pp. 238-244 ◽  
Author(s):  
Ari Pedro Balieiro Jr. ◽  
Emmanuelle Silva Tavares Sobreira ◽  
Marina Ceres Silva Pena ◽  
José Humberto Silva-Filho ◽  
Francisco de Assis Carvalho do Vale
Keyword(s):  
Alzheimer’S Disease ◽  
Alzheimer's Disease ◽  
Psychological Symptoms ◽  
Time Behavior ◽  
Caregiver Distress ◽  
Night Time ◽  
The Mean ◽  
The Individual ◽  
The Relationship ◽  
Behavioral And Psychological Symptoms

Abstract The aim of this study was to analyze the relationship between Caregiver Distress and Behavioral and Psychological Symptoms in Dementias (BPSD) in mild Alzheimer's disease. Methods: Fifty patients and caregivers were interviewed using the Neuropsychiatric Inventory (NPI). Results: 96.0% of the patients had at least one BPSD. The mean NPI total score was 19.6 (SD=18.05; range=0-78) whereas the mean Caregiver Distress Index (CDI) total score was 11.5 (SD=10.41; range=0-40). For the individual symptoms, the weighted mean CDI was 2.8 (SD=1.58). All symptom CDI means were higher than 2.0 except for euphoria/elation (m=1.8; SD=1.49). There were correlations between CDI and derived measures (Frequency, Severity, FxS, and Amplitude) for all symptoms, except Disinhibition and Night-time behavior. Correlations ranged between 0.443 and 0.894, with significance at p<0.05. Conclusions: All the derived measures, including amplitude, were useful in at least some cases. The data suggests that CDI cannot be inferred from symptom presence or profile. Symptoms should be systematically investigated.

Relationship between Rated Degree of Familiarity with Individual Sentences and the Extent of Recall of Connected Discourse

1966 ◽  
Vol 19 (3_suppl) ◽  
pp. 1195-1202 ◽  
Author(s):  
John A. Mills ◽  
Alan Nicolas-Fanourakis
Keyword(s):  
Rating Scale ◽  
Interference Theory ◽  
Connected Discourse ◽  
Wide Range ◽  
The Mean ◽  
The Individual ◽  
The Relationship

An assessment was made of the strength and direction of the relationship between rated degree of familiarity for connected discourse and the extent of recall of such material. The experimental material consisted of two short passages of prose (a narrative and an argument) and of a rating scale containing all the sentences from these passages inserted randomly among other individual sentences selected from a wide range of sources. 20 Ss provided both recall scores for the passages (which were presented whole) and familiarity ratings for the sentences in the rating scale. When recall scores for the individual sentences were correlated with the mean ratings, a positive and significant value was found. The bearing of this finding on (he expectations of interference theory is discussed.

scholarly journals Personality and Motivation: A Correlation study among Sports Person

2019 ◽  
Vol 6 (4) ◽  
pp. 5-13
Author(s):  
M Keerthika ◽  
S Punithavathi
Keyword(s):  
Standard Deviation ◽  
Gender Difference ◽  
Correlation Coefficient ◽  
Significant Relationship ◽  
Correlation Study ◽  
Motivation Factors ◽  
The Mean ◽  
The Individual ◽  
Age Range ◽  
The Relationship

In this competitive world, it is essential to grab the sportive nature of sports persons. For different personality type of the individual the motive to engage in sports also varies from person to person. The aim of the present study is to determine the relationship between personality and motivation among sports persons and to identify the gender difference of personality and motivation factors. The sample of this study was 120 sports persons out of which 60 were males and 60 were females belonging to the age range of 18 -30 years. The mean, standard deviation and Pearson’s correlation coefficient were used for analysing the data. Results indicate that there is no significant relationship between Personality and Motivation type of sports persons.

scholarly journals The Relationship Between Intensity Indicators in Small-Sided Soccer Games

2015 ◽  
Vol 46 (1) ◽  
pp. 119-128 ◽  
Author(s):  
David Casamichana ◽  
Julen Castellano
Keyword(s):  
Heart Rate ◽  
External Load ◽  
Perceived Exertion ◽  
Internal Load ◽  
Heart Rate Monitors ◽  
The Mean ◽  
Gps Devices ◽  
The Individual ◽  
The Relationship ◽  
Mean Heart Rate

AbstractThe aim of the present study was to examine the relationship between different kinds of intensity indicators in small-sided soccer games. This descriptive correlational study included 14 semi-professional male soccer players (21.3 ± 2.3 years, 174 ± 4.0 cm, 73.4 ± 5.1 kg) from the same team. The players were monitored by means of heart rate monitors and GPS devices during 27 small-sided games of nine different formats, yielding a total of 217 recordings. After each game the Borg scale was used to give a rate of perceived exertion (RPE). The internal load indicators were the mean heart rate relative to the individual maximum (%HRmean) and the RPE, while those for the external load were the player load, total distance covered, distance covered in two intensity ranges (>18 km·h-1 and >21 km·h-1), and frequency of effort (in the same two intensity ranges). There was a significant moderate correlation (r=0.506) between the two internal load measurements (%HRmean and RPE). Although there were significant correlations of different degrees between various external load measurements, only the player load was significantly correlated with the internal load indicators (r=0.331 with %HRmean and r=0.218 with RPE). During training programes of this kind, it is necessary to consider a range of intensity indicators so as to obtain complementary information. This will enable coaches to more accurately assess the load imposed on players and therefore optimize the training process.

Analysis of post-weaning growth in pigs

1939 ◽  
Vol 29 (2) ◽  
pp. 274-294 ◽  
Author(s):  
A. D. Buchanan Smith ◽  
H. P. Donald
Keyword(s):  
Litter Size ◽  
Carcass Quality ◽  
Small Animals ◽  
Absolute Rate ◽  
Rate Of Growth ◽  
The Mean ◽  
The Individual ◽  
Relationship Of ◽  
The Relationship ◽  
Graphical Illustration

1. The post-weaning growth of 135 litters has been analysed with a view to determining the relationship of certain arbitrary subdivisions with each other. For this purpose, the weight increases during three periods of 28 days have been denned in two ways—first, by age, the periods being 10–14, 14–18, and 18–22 weeks, and secondly, by weight, the periods beginning at 40, 80 and 120 lb. and continuing as before for 4 weeks.2. When the periods are defined by age, the mean increase per pig per litter is affected by weaning weight, but not by litter size (Table III). The variability of the individual increases becomes greater as the pigs become older and heavier (that is, passing from one period to a later one), but less within a period as the rate of growth increases (Table IV). It was not affected by litter size.3. The distribution of individual weights became increasingly skew with age. This is regarded as a graphical illustration of the fact that while absolute rate of growth is increasing, initially small animals must fall farther and farther behind (Graph 3).4. The correlations between the average litter increases in different periods were calculated for litter sizes 6–11. In general, the coefficient for periods 1 and 2 was about 0·4, and for periods 2 and 3 about 0·6 (Table VI). This is interpreted to mean that, when judged by results over the whole time under observation, litters with a high correlation between the increases in weight during short periods are not properly comparable with those with a low correlation. By this method, differences in rate of growth having an important influence on carcass quality may be obscured.

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