Further Observations on Breeding of Dermochelys coriacea in Australia

1984 ◽  
Vol 11 (3) ◽  
pp. 567 ◽  
Author(s):  
CJ Limpus ◽  
NC McCachlan ◽  
JD Miller
Keyword(s):  
Gas Exchange ◽  
Hatching Success ◽  
Fine Sand ◽  
Dermochelys Coriacea ◽  
Leatherback Turtle ◽  
Mean Size ◽  
The Mean ◽  
High Level ◽  
Embryonic Death

In Australia, breeding of the cosmopolitan leatherback turtle, Dermochelys coriacea, is concentrated on 22.3 km of beach near Wreck Rock (24�19'S., 151�58'E.) in south-east Queensland. Up to three females nest there in most years. The mean size of 14 clutches was 82.79; the mean hatching success was 15.3% for clutches on the beach and 51.8% for these moved to dunes near the laboratory. The high level of failure is attributed to early embryonic death, probably caused by the fine sand, when damp, restricting gas exchange round the eggs.

Influence of Egg Characteristics on Survival, Growth and Feeding in Larval Walleye (Stizostedion vitreum)

1989 ◽  
Vol 46 (3) ◽  
pp. 516-521 ◽  
Author(s):  
G. E. E. Moodie ◽  
N. L. Loadman ◽  
M. D. Wiegand ◽  
J. A. Mathias
Keyword(s):  
Fatty Acids ◽  
Mortality Rate ◽  
Growth Rates ◽  
Egg Size ◽  
The Other ◽  
Stizostedion Vitreum ◽  
Mean Size ◽  
Survival And Growth ◽  
The Mean ◽  
High Level

A subsample of eggs from 109 walleye (Stizostedion vitreum) from Crean Lake, Saskatchewan, was sieved soon after fertilization to yield four groups of eggs ranging in size from 4.86 to 5.62 mm3. Overall egg size tended to correspond to yolk and oil volumes. At hatching, larvae from the eggs with the least yolk and oil were significantly shorter than larvae from all other egg groups. At the end of the experiment, 13 d after hatching, the larvae from the eggs with the most yolk were significantly larger than larvae from the other egg groups. Differences in the mean amount of food ingested by larvae were related to initial egg size. The yolk of the smallest eggs was deficient in the (n-3) series of polyunsaturated fatty acids. Larvae from these small eggs had a high level of major body deformities and a mortality rate which reached 100% by day 10. Small egg size in itself did not appear disadvantageous; larvae from a different stock (Lake of the Prairies, Manitoba) which produced eggs with a mean size less than that of the smallest sieved eggs, had survival and growth rates comparable with those of the larger Crean Lake eggs.

Aeolian Sand Size on the Surface of the Northern Foothill of Yinshan Mountain

2014 ◽  
Vol 668-669 ◽  
pp. 1499-1508
Author(s):  
Hong Tao Jiang ◽  
Chun Rong Guo ◽  
Chun Xing Hai ◽  
Jun Xiu Liu ◽  
Yun Hu Xie ◽  
...  
Keyword(s):  
Grain Size ◽  
Fine Sand ◽  
Aeolian Sand ◽  
Size Characteristic ◽  
Different Seasons ◽  
Mean Size ◽  
The Mean ◽  
Soil Flux ◽  
The Vertical Distribution ◽  
Grain Size Parameters

Sand samplers were laid out in the grassland in the northern foot of Yinshan Mountain for collecting soil flux samples from 0 to 1.5m height above the surface from Mar, 1, 2008 to Feb,29,2009.Grain size parameters proposed by Folk and Ward, including average, SD, skewness and kurtosis of grain size were used. The vertical distribution of grain size characteristic of sediments trapped by sand samplers in different seasons was analyzed by using electrical mirror technology. The results indicated that size of aeolian sand in desert steppe is mainly sand and silt. The content of coarse silt, very fine sand and medium sand are 20~60%,10~30% and 10~20%,respectively,in the sediment–for all seasons. As height increased, the content of sand decreased while silt increased and the mean size of particle changed from fine sand to very fine sand. The mean diameter of particle ranged from 2.4~4.2and standard deviation ranged from 0.7~1.5Skewness is positive with the value ranges from 0 to 0.2,while Kurtosis mainly concentrated on 0.7 to 1.3.

scholarly journals Flow of River Tigris and its Effect on the Bed Sediment within Baghdad, Iraq

2015 ◽  
Vol 5 (1) ◽  
Author(s):  
Nadhir Al-Ansari ◽  
Ammar A. Ali ◽  
Qusay Al-Suhail ◽  
Sven Knutsson
Keyword(s):  
Cross Sections ◽  
Fine Sand ◽  
Bed Sediment ◽  
Sediment Characteristics ◽  
Bed Elevation ◽  
Tigris River ◽  
Median Size ◽  
Mean Size ◽  
Major River ◽  
The Mean

AbstractRiver Tigris is a major river in Iraq. Sediment at the bed of the river within a reach of about 18 km from the center of Baghdad upstream was investigated. Sixty five cross sections were surveyed, and 46 sediment samples were collected and analyzed. It was noticed that fine sand was dominant in the bed (90.74%). The average median size within the reach was 2.49 phi (0.177 mm), while the mean size was 2.58 phi (0.16 mm). In addition, the sediments were moderately sorted, fine skewed and leptokurtic. The size of the bed sediment decreased relative to previous investigations due to the construction of the Adhaim dam on tributary, which used to be the main sediment supplier to the Tigris River before entering Baghdad. Furthermore, the discharge of the Tigris River for the period 1983–2013 (715 m3/s) decreased by about 40% and 30%since 1983when compared with the periods 1931–1956 (1208 m3/s) and 1956–1980 (1015 m3/s), respectively, due to climate change and construction of dams upstream from Baghdad. This has decreased the capacity and the competence of the river. The bed elevation has increased compared to previous surveys. Itwas noticed that dredging operations and obstructions (e.g. fallen bridges and islands) have disturbed the flow of the river and sediment characteristics in several sites.

Effect of egg location and respiratory gas concentrations on developmental success in nests of the leatherback turtle, Dermochelys coriacea

2005 ◽  
Vol 53 (5) ◽  
pp. 289 ◽  
Author(s):  
Cameron R. Ralph ◽  
Richard D. Reina ◽  
Bryan P. Wallace ◽  
Paul R. Sotherland ◽  
James R. Spotila ◽  
...  
Keyword(s):  
Carbon Dioxide ◽  
Spatial Variation ◽  
Oxygen Tension ◽  
Late Stage ◽  
Hatching Success ◽  
Early Death ◽  
Carbon Dioxide Tension ◽  
Dermochelys Coriacea ◽  
Late Death ◽  
Embryonic Death

Hatching success of leatherback turtles, Dermochelys coriacea, is typically ~50%, but the reasons for embryonic death are unknown. We investigated the distribution of egg failure within 16 developing nests to determine whether spatial position or respiratory environment was associated with embryonic death. We measured oxygen and carbon dioxide partial pressures during incubation to investigate whether any spatial variation in developmental success was associated with regions of hypoxia or hypercapnia. Eggs in the centre of nests had a significantly lower mean hatching success (42.1 ± 7.6%) than eggs in the intermediate (66.1 ± 5.3%) and peripheral (69.8 ± 3.5%) regions. Of those eggs that died, there were no significant differences in the timing of early- and late-stage embryonic death in central (77.6 ± 7.2% early death, 17.3 ± 8.2% late death) and peripheral (80.8 ± 10.1% early death, 14.7 ± 5.8% late death) regions. Oxygen tension in all regions of nests was significantly lower and carbon dioxide tension was significantly higher than in control nests by Day 35 of incubation. Although spatial variation in respiratory gases was detected, it did not appear to explain spatially variable developmental success because late-stage embryonic death did not increase in the central region where oxygen tension was lowest and carbon dioxide tension was highest.

scholarly journals Embryonic Death Is Linked to Maternal Identity in the Leatherback Turtle (Dermochelys coriacea)

PLoS ONE ◽  
2011 ◽  
Vol 6 (6) ◽  
pp. e21038 ◽  
Author(s):  
Anthony R. Rafferty ◽  
Pilar Santidrián Tomillo ◽  
James R. Spotila ◽  
Frank V. Paladino ◽  
Richard D. Reina
Keyword(s):  
Dermochelys Coriacea ◽  
Maternal Identity ◽  
Leatherback Turtle ◽  
Embryonic Death

DFT Benchmark Study of the O--O Bond Dissociation Energy in Peroxides Validated with High-Level Ab-Initio Calculations

2019 ◽  
Author(s):  
Danilo Carmona ◽  
Pablo Jaque ◽  
Esteban Vöhringer-Martinez
Keyword(s):  
Reference Value ◽  
Basis Set ◽  
Basis Sets ◽  
Mean Deviation ◽  
Bond Dissociation ◽  
Dissociation Energies ◽  
The Mean ◽  
Experimental Values ◽  
High Level ◽  
Almost All

<div><div><div><p>Peroxides play a central role in many chemical and biological pro- cesses such as the Fenton reaction. The relevance of these compounds lies in the low stability of the O–O bond which upon dissociation results in radical species able to initiate various chemical or biological processes. In this work, a set of 64 DFT functional-basis set combinations has been validated in terms of their capability to describe bond dissociation energies (BDE) for the O–O bond in a database of 14 ROOH peroxides for which experimental values ofBDE are available. Moreover, the electronic contributions to the BDE were obtained for four of the peroxides and the anion H2O2− at the CBS limit at CCSD(T) level with Dunning’s basis sets up to triple–ζ quality provid- ing a reference value for the hydrogen peroxide anion as a model. Almost all the functionals considered here yielded mean absolute deviations around 5.0 kcal mol−1. The smallest values were observed for the ωB97 family and the Minnesota M11 functional with a marked basis set dependence. Despite the mean deviation, order relations among BDE experimental values of peroxides were also considered. The ωB97 family was able to reproduce the relations correctly whereas other functionals presented a marked dependence on the chemical nature of the R group. Interestingly, M11 functional did not show a very good agreement with the established order despite its good performance in the mean error. The obtained results support the use of similar validation strategies for proper prediction of BDE or other molecular properties by DF Tmethods in subsequent related studies.</p></div></div></div>

The way of value of Correlation of genomic DNA microsatellite loci and live weight of Chukchi reindeer

2020 ◽  
pp. 27-32
Author(s):  
V. Dodokhov ◽  
N. Pavlova ◽  
T. Rumyantseva ◽  
L. Kalashnikova
Keyword(s):  
Microsatellite Markers ◽  
Agricultural Production ◽  
Live Weight ◽  
Biodiversity Loss ◽  
Tribal Community ◽  
High Germination ◽  
Wide Range ◽  
The Mean ◽  
High Level ◽  
Dna Microsatellite

The article presents the genetic characteristic of the Chukchi reindeer breed. The object of the study was of the Chukchi reindeer. In recent years, the number of reindeer of the Chukchi breed has declined sharply. Reduced reindeer numbers could lead to biodiversity loss. The Chukchi breed of deer has good meat qualities, has high germination viability and is adapted in adverse tundra conditions of Yakutia. Herding of the Chukchi breed of deer in Yakutia are engaged only in the Nizhnekolymsky district. There are four generic communities and the largest of which is the agricultural production cooperative of nomadic tribal community «Turvaurgin», which was chosen to assess the genetic processes of breed using microsatellite markers: Rt6, BMS1788, Rt 30, Rt1, Rt9, FCB193, Rt7, BMS745, C 143, Rt24, OheQ, C217, C32, NVHRT16, T40, C276. It was found that microsatellite markers have a wide range of alleles and generally have a high informative value for identifying of genetic differences between animals and groups of animal. The number of identified alleles is one of the indicators of the genetic diversity of the population. The total number of detected alleles was 127. The Chukchi breed of deer is characterized by a high level of heterozygosity, and the random crossing system prevails over inbreeding in the population. On average, there were 7.9 alleles (Na) per locus, and the mean number of effective alleles (Ne) was 4.1. The index of fixation averaged 0.001. The polymorphism index (PIC) ranged from 0.217 to 0.946, with an average of 0.695.

Nutrient Concentrations in Soil Solution in an Alfisol under Grapefruit Production

HortScience ◽  
1998 ◽  
Vol 33 (3) ◽  
pp. 498d-498
Author(s):  
Z.L. He ◽  
A.K. Alva ◽  
D.V. Calvert ◽  
D.J. Banks ◽  
Y.C. Li
Keyword(s):  
Soil Solution ◽  
Fine Sand ◽  
Drainage Water ◽  
Tree Canopy ◽  
Nutrient Concentrations ◽  
Sour Orange ◽  
Parallel Study ◽  
Ph Measurements ◽  
The Mean ◽  
N Rates

A field experiment was conducted in a Riviera fine sand (Alfisol) with 25-year-old `White Marsh' grapefruit trees on Sour orange rootstock to monitor the downward transport of nutrients from fertilization practices. Fertilizer was applied as either dry granular broadcast (three applications/year) or fertigation (15 applications/year) at N rates of 56, 112, 168, and 336 kg/ha per year using a N:P:K blend (1.0:0.17:1.0). Soil solution was sampled bi-weekly from suction lysimeters, installed under the tree canopy, about 120 cm from the tree trunk, at two depths representing above (120 cm) and below (180 cm) the hard pan. The concentrations of K, Ca, and Mg were greater at the 180- than at 120-cm depth, whereas, the converse was true with respect to the concentration of P in soil solution. Over a 2-year period, the mean concentrations of P and K varied from 0.031-0.976 and 150-250 mg·L–1, respectively. Increased rate of fertilization also appeared to increase the concentrations of Ca and Mg in the soil solution. This could be due to effects of slight acidification of the soil with increased rates of ammonium form of N. A parallel study on pH measurements has shown evidence of soil acidification, under the tree canopy, with increased rates of ammonium fertilization. In a bedded grove, the soil solution above the hard pan is likely to seep into the water furrow, which is discharged into the drainage water.

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