scholarly journals Available Information for Estimating Reproductive Potential of Northwest Atlantic Groundfish Stocks

2003 ◽  
Vol 33 ◽  
pp. 1-21 ◽  
Author(s):  
J Tomkiewicz ◽  
M J Morgan ◽  
J Burnett ◽  
F Saborido-Rey
Keyword(s):  
Reproductive Potential ◽  
Northwest Atlantic ◽  
Available Information

A mathematical model of fertilization failure and early embryonic mortality in sheep

1977 ◽  
Vol 89 (2) ◽  
pp. 309-317 ◽  
Author(s):  
P. A. Geisler ◽  
J. E. Newton ◽  
A. E. Mohan
Keyword(s):  
Mathematical Model ◽  
Reproductive Potential ◽  
Embryonic Mortality ◽  
Experimental Results ◽  
Fertilization Failure ◽  
Early Embryonic Mortality ◽  
Available Information

SummaryThe reproductive potential of a sheep system is much reduced by the failure of released ova to be fertilized and to survive to parturition. This paper looks at currently available information on fertilization failure and early embryonic deaths. Separate hypotheses are proposed for fertilization and for early embryonic mortality. For fertilization, the hypothesis is that a ewe that mates with a ram will end up with either all or none of her released ova fertilized. For embryonic mortality, the hypothesis is that the survival of a fertilized ovum depends only on how many ova were released with it and is independent of the survival or death of those released with it. A mathematical model is constructed on these hypotheses and its predictions are compared with published experimental results of other workers.

scholarly journals Did population collapse influence individual fecundity of Northwest Atlantic cod?

2007 ◽  
Vol 64 (7) ◽  
pp. 1338-1347 ◽  
Author(s):  
J. C. Stares ◽  
R. M. Rideout ◽  
M. J. Morgan ◽  
J. Brattey
Keyword(s):  
Egg Production ◽  
Gadus Morhua ◽  
Atlantic Cod ◽  
Reproductive Potential ◽  
Population Recovery ◽  
Potential Fecundity ◽  
Northwest Atlantic ◽  
Population Collapse ◽  
Variable Nature ◽  
Individual Fecundity

Abstract Stares, J. C., Rideout, R. M., Morgan, M. J., and Brattey, J. 2007. Did population collapse influence individual fecundity of Northwest Atlantic cod? – ICES Journal of Marine Science, 64:1338 –1347. We examined the influence of population collapse on individual potential fecundity and total population egg production (TEP) of three northwest Atlantic cod (Gadus morhua) populations: northern cod (Divisions 2J3KL), southern Grand Bank cod (NAFO Divisions 3NO), and southern Newfoundland cod (Subdivision 3Ps). Fecundity at length increased in conjunction with population collapse for two (3NO, 3Ps) of the three populations. Subsequent moderate population recovery between the 1990s and 2000s in 3Ps was accompanied by a decrease in fecundity at length. A large decrease in fecundity at length for 3NO during the same time period, despite little or no population recovery, coupled with the fact that there was no obvious difference in fish condition between the two time periods, suggested that density-independent factors could be contributing to the changes in fecundity. Use of pre-collapse fecundity–length relationships to estimate TEP in the post-collapse period resulted in underestimation of TEP by as much as 30% in 3NO and 46% in 3Ps, whereas in 2J3KL, TEP was overestimated by as much as 18%. Although the results do not fully support the hypothesis of an inverse relationship between population size and fecundity, they do demonstrate the variable nature of cod fecundity which, if not accounted for, can lead to erroneous perceptions of stock reproductive potential.

Temporal Changes in the Reproductive Potential of Female Harp Seals (Pagophilus groenlandicus)

1981 ◽  
Vol 38 (5) ◽  
pp. 495-503 ◽  
Author(s):  
W. Don Bowen ◽  
Charles K. Capstick ◽  
David E. Sergeant
Keyword(s):  
Density Dependence ◽  
Population Size ◽  
Empirical Data ◽  
Reproductive Potential ◽  
Fertility Rate ◽  
Harp Seal ◽  
Northwest Atlantic ◽  
Pagophilus Groenlandicus ◽  
Age Of Maturity ◽  
Biological Sampling

The Northwest Atlantic harp seal (Pagophilus groenlandicus) population declined by more than 50% between 1952 and the early 1970s. Biological sampling of female reproductive tracts began in 1951 and has continued to the present. We reexamined the extent to which mean age of maturity and fertility rate have changed as population size declined. Mean age of maturity declined from ~ 6.2 yr in 1952 to 4.5 yr in 1979. During this same period fertility rate increased from 85 to 94%. Both parameters have changed concurrently with a decline in numbers. Although it is likely that density-dependent mechanisms are involved, empirical data are lacking.Key words: harp seals, Pagophilus groenlandicus; maturity, fertility, density-dependence

Ultrastructural Alterations in Hela Cells Induced by Spider Venom

1967 ◽  
Vol 25 ◽  
pp. 20-21
Author(s):  
Dale E. McClendon ◽  
Paul N. Morgan ◽  
Bernard L. Soloff
Keyword(s):  
Growth Medium ◽  
Mammalian Cells ◽  
Carcinoma Cells ◽  
Venom Protein ◽  
Sterile Saline ◽  
Carbon Coated ◽  
Available Information ◽  
Loxosceles Reclusa ◽  
Essential Growth ◽  
Solution Cultures

It has been observed that minute amounts of venom from the brown recluse spider, Loxosceles reclusa, are capable of producing cytotoxic changes in cultures of certain mammalian cells (Morgan and Felton, 1965). Since there is little available information concerning the effect of venoms on susceptible cells, we have attempted to characterize, at the electron microscope level, the cytotoxic changes produced by the venom of this spider.Cultures of human epithelial carcinoma cells, strain HeLa, were initiated on sterile, carbon coated coverslips contained in Leighton tubes. Each culture was seeded with approximately 1x105 cells contained in 1.5 ml of a modified Eagle's minimum essential growth medium prepared in Hank's balanced salt solution. Cultures were incubated at 36° C. for three days prior to the addition of venom. The venom was collected from female brown recluse spiders and diluted in sterile saline. Protein determinations on the venom-were made according to the spectrophotometric method of Waddell (1956). Approximately 10 μg venom protein per ml of fresh medium was added to each culture after discarding the old growth medium. Control cultures were treated similarly, except that no venom was added. All cultures were reincubated at 36° C.

Eds Of Radioactive Particles By Self-Induced Fluorescence

1990 ◽  
Vol 48 (2) ◽  
pp. 238-239
Author(s):  
Gregory L. Finch ◽  
Richard G. Cuddihy
Keyword(s):  
Electron Beam Irradiation ◽  
Nuclear Reactor ◽  
X Rays ◽  
Reactor Accident ◽  
Internal Radiation ◽  
X Ray ◽  
External Sources ◽  
X Irradiation ◽  
Available Information ◽  
Individual Particles

The elemental composition of individual particles is commonly measured by using energydispersive spectroscopic microanalysis (EDS) of samples excited with electron beam irradiation. Similarly, several investigators have characterized particles by using external monochromatic X-irradiation rather than electrons. However, there is little available information describing measurements of particulate characteristic X rays produced not from external sources of radiation, but rather from internal radiation contained within the particle itself. Here, we describe the low-energy (< 20 KeV) characteristic X-ray spectra produced by internal radiation self-excitation of two general types of particulate samples; individual radioactive particles produced during the Chernobyl nuclear reactor accident and radioactive fused aluminosilicate particles (FAP). In addition, we compare these spectra with those generated by conventional EDS.Approximately thirty radioactive particle samples from the Chernobyl accident were on a sample of wood that was near the reactor when the accident occurred. Individual particles still on the wood were microdissected from the bulk matrix after bulk autoradiography.

The Multiple Faces of Risk-Taking

2016 ◽  
Vol 32 (1) ◽  
pp. 17-38 ◽  
Author(s):  
Florian Schmitz ◽  
Karsten Manske ◽  
Franzis Preckel ◽  
Oliver Wilhelm
Keyword(s):  
Risk Taking ◽  
Basic Research ◽  
Formal Models ◽  
Experimental Paradigm ◽  
Nomological Network ◽  
Balloon Analogue Risk Task ◽  
Parameter Recovery ◽  
Task Specificity ◽  
Available Information ◽  
Criterion Variables

Abstract. The Balloon-Analogue Risk Task (BART; Lejuez et al., 2002 ) is one of the most popular behavioral tasks suggested to assess risk-taking in the laboratory. Previous research has shown that the conventionally computed score is predictive, but neglects available information in the data. We suggest a number of alternative scores that are motivated by theories of risk-taking and that exploit more of the available data. These scores can be grouped around (1) risk-taking, (2) task performance, (3) impulsive decision making, and (4) reinforcement sequence modulation. Their theoretical rationale is detailed and their validity is tested within the nomological network of risk-taking, deviance, and scholastic achievement. Two multivariate studies were conducted with youths (n = 435) and with adolescents/young adults (n = 316). Additionally, we tested formal models suggested for the BART that decompose observed behavior into a set of meaningful parameters. A simulation study with parameter recovery was conducted, and the data from the two studies were reanalyzed using the models. Most scores were reliable and differentially predictive of criterion variables and may be used in basic research. However, task specificity and the generally moderate validity do not warrant use of the experimental paradigm for diagnostic purposes.

Review of operational indications on the design of facilities for radiopharmaceutical manufacturing in italy

2020 ◽  
Author(s):  
M.A. D’Avanzo ◽  
G.M. Contessa ◽  
G. Cocomello ◽  
M. Mattozzi ◽  
M. Pacilio ◽  
...  
Keyword(s):  
Ionizing Radiation ◽  
Design Stage ◽  
Safety Aspects ◽  
Scientific Institutions ◽  
Available Information

Purpose. In this article, the authors propose useful operational indications to approach in the best possible way the issues concerning the design of a facility for manufacturing radiopharmaceuticals, with focus on organizational and safety aspects. Methods. Several documents produced by authoritative bodies, national and international scientific institutions and associations were examined and referenced, to the purpose of reviewing all available information in the field. Results. Indications are gathered for the design stage, including the organization of accesses and routes and characteristics and requirements of premises and systems. Conclusions. Main goal is to guide the reader in evaluating and choosing the most suitable features and equipment to limit the risks due to ionizing radiation and to prevent contamination of the workers and the environment.

Cardiac arrhythmias related to psychiatric medication

2017 ◽  
Vol 36 (09) ◽  
pp. 747-750
Author(s):  
R. W. Freudenmann ◽  
C. Schönfeldt-Lecuona ◽  
B. J. Connemann ◽  
M. Gahr ◽  
M. Elsayed
Keyword(s):  
Cardiac Arrhythmias ◽  
Torsade De Pointes ◽  
General Medicine ◽  
Fold Increase ◽  
Cardiac Risk ◽  
Psychiatric Medication ◽  
Cardiac Side Effects ◽  
Torsade De Pointes Tachycardia ◽  
Multiple Drugs ◽  
Available Information

SummaryThis narrative review summarizes current available information about cardiac arrhythmias (QT prolongation, Torsade de pointes Tachycardia [TdP], sudden cardiac death) associated with psychiatric medication. Among the most commonly used antipsychotics, amisulpride and ziprasidone are most frequently associated with TdP. Treatment with some antidepressants (SSRIs, tricyclic antidepressants) is associated with a 5- to 6-fold increase in the incidence of out-of-hospital cardiac arrest. Lithium is associated with bradycardia, T-wave changes and AV-block; anxiolytics of the benzodiazepine group do usually not have cardiac side effects. The combination of multiple drugs (including medications from general medicine) that prolong the QT interval has a particularly high cardiac risk.

K-MEANS CLUSTERING ALGORITHM BASED CLASSIFICATION OF SOIL FERTILITY IN NORTH WEST NIGERIA

2020 ◽  
Vol 4 (2) ◽  
pp. 780-787
Author(s):  
Ibrahim Hassan Hayatu ◽  
Abdullahi Mohammed ◽  
Barroon Ahmad Isma’eel ◽  
Sahabi Yusuf Ali
Keyword(s):  
Soil Fertility ◽  
Crop Yield ◽  
Clustering Algorithm ◽  
Soil Samples ◽  
North West ◽  
R Programming ◽  
Available Information ◽  
Northwest Region ◽  
The Relationship

Soil fertility determines a plant's development process that guarantees food sufficiency and the security of lives and properties through bumper harvests. The fertility of soil varies according to regions, thereby determining the type of crops to be planted. However, there is no repository or any source of information about the fertility of the soil in any region in Nigeria especially the Northwest of the country. The only available information is soil samples with their attributes which gives little or no information to the average farmer. This has affected crop yield in all the regions, more particularly the Northwest region, thus resulting in lower food production.  Therefore, this study is aimed at classifying soil data based on their fertility in the Northwest region of Nigeria using R programming. Data were obtained from the department of soil science from Ahmadu Bello University, Zaria. The data contain 400 soil samples containing 13 attributes. The relationship between soil attributes was observed based on the data. K-means clustering algorithm was employed in analyzing soil fertility clusters. Four clusters were identified with cluster 1 having the highest fertility, followed by 2 and the fertility decreases with an increasing number of clusters. The identification of the most fertile clusters will guide farmers on where best to concentrate on when planting their crops in order to improve productivity and crop yield.

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