A method of age determination in Lucilia cuprina (Wied.) (Diptera, Calliphoridae) using cyclic changes in the female reproductive system

1974 ◽  
Vol 64 (3) ◽  
pp. 365-370 ◽  
Author(s):  
W. G. Vogt ◽  
T. L. Woodburn ◽  
Marina Tyndale-Biscoe
Keyword(s):  
Age Determination ◽  
Ovarian Cycle ◽  
Reproductive Age ◽  
Lucilia Cuprina ◽  
Egg Formation ◽  
Temperature Regimes ◽  
Minimum Age ◽  
Time Required ◽  
Cyclic Changes ◽  
Oviposition Sites

AbstractThe stage of egg formation and density of follicular relics enable Lucilia cuprina (Wied.) females to be sorted into 16 ovarian stages, covering the period from emergence to the beginning of the fourth ovarian cycle. The correspondence between the actual age of a fly and its stage of ovarian development was determined at constant temperatures. Where developmental delays were absent, “reproductive age” gave reliable estimates of actual age under both constant and fluctuating temperature regimes. In the field protein shortages and lack of oviposition sites may prolong the time required to complete each ovarian cycle, and flies will be older than their ovaries would indicate. In practice the ovarian stages described provide estimates of minimum age for L. cuprina females.

HISTOMORPHOLOGICAL CHANGES IN THE BRAIN IN RELATION TO OVARIAN CYCLE OF FRESHWATER CRAB, BARYTELPHUSA CUNICULARIS

2017 ◽  
Vol 23 (1) ◽  
Author(s):  
C.A. JAWALE
Keyword(s):  
Staining Intensity ◽  
Neurosecretory Cells ◽  
Ovarian Cycle ◽  
Secretory Product ◽  
Freshwater Crab ◽  
Intensity Index ◽  
Cytoplasmic Material ◽  
Histomorphological Changes ◽  
Cyclic Changes ◽  
The Brain

Ovarian maturation by neurosecretory cells in the brain of freshwater crab, Barytelphusa cunicularis have been examined. The histological scrutiny of the brain of Barytelphusa cunicularis related with three types (A, B and C) of neurosecretory cells, which are classified on the basis of size, shape and tinctorial characters. All these types of cells marked annual cyclic changes of cytoplasmic material in association with ovarian cycle. The activity of these cells has been correlated with the ovarian cycle. They are distinguishable by their size, nature locations, shape, nucleus position, cell measure and the secretory product in the cytoplasm. The result indicates that the neurosecretory A, B and C cells of the brain seen involved in the process of mating ovulation. The neurosecretory materials staining intensity index of these cells is described.

scholarly journals Hipparcos subdwarfs and globular cluster ages: towards reliable absolute ages

1997 ◽  
Vol 189 ◽  
pp. 433-438 ◽  
Author(s):  
F. Pont ◽  
M. Mayor ◽  
C. Turon
Keyword(s):  
Globular Cluster ◽  
Globular Clusters ◽  
Large Fraction ◽  
Age Determination ◽  
Colour Scale ◽  
Minimum Age ◽  
Age Of The Universe ◽  
Robust Prediction ◽  
The Universe ◽  
Cluster Age

The maximum age of galactic globular clusters provides the best observational constraint on the minimum age of the Universe. One of the main “missing link” in the globular cluster age determination has been the lack of a precise calibration, with local subdwarfs, of the position of the subdwarf sequence at different [Fe/H].Hipparcos data may change this situation. As many precise parallaxes become available for local subdwarfs, the distance to globular clusters can be estimated directly from ZAMS fitting to the subdwarf locus. The ages can then be inferred from the turnoff luminosity (a robust prediction of stellar evolution models), rather than using secondary indicators such as Horizontal-Branch position, or indicators depending on the uncertain colour scale such as turnoff colour.Combining Hipparcos parallaxes with [Fe/H] values determined with the CORAVEL spectrometer, we are studying the position of the subdwarfs in the Colour-Magnitude Diagram from a sample of more than 900 subdwarf candidates. Preliminary results are presented here. It is shown that the distances of many subdwarfs had been underestimated in previous studies, mainly because a large fraction of them is in fact evolved off the main sequence into the turnoff or the subgiant branch.

The choice of communal Oviposition sites by the Australian sheep blowfly. Lucilia cuprina.

1958 ◽  
Vol 6 (3) ◽  
pp. 241 ◽  
Author(s):  
L Vartib-Browne
Keyword(s):  
Lucilia Cuprina ◽  
High Humidity ◽  
Cotton Wool ◽  
Secondary Importance ◽  
Australian Sheep ◽  
Large Groups ◽  
Oviposition Sites

Large groups of eggs representing the oviposition of a number of females of Lucilia cuprina are frequently found on fleece preparations. Females were shown to have a preference for ovipositing in cavities in the fleece, especially those near the moist cotton-wool plugs. The cavities are primarily attractive as places of high humidity and low illuminance. Of secondary importance is the preference of females for laying at places where other females are already ovipositing.

scholarly journals Functional requirement of AgRP and NPY neurons in ovarian cycle-dependent regulation of food intake

2009 ◽  
Vol 106 (37) ◽  
pp. 15932-15937 ◽  
Author(s):  
Louise E. Olofsson ◽  
Andrew A. Pierce ◽  
Allison W. Xu
Keyword(s):  
Food Intake ◽  
Estrous Cycle ◽  
Estrogen Receptor Alpha ◽  
Ovarian Cycle ◽  
Central Administration ◽  
Related Protein ◽  
17Β Estradiol ◽  
Cycle Dependent ◽  
Cyclic Changes ◽  
Agouti Related Protein

In female mammals including rodents and humans, feeding decreases during the periovulatory period of the ovarian cycle, which coincides with a surge in circulating estrogen levels. Ovariectomy increases food intake, which can be normalized by estrogen treatment at a dose and frequency mimicking those during the estrous cycle. Furthermore, administration of estrogen to rodents potently inhibits food intake. Despite these well-known effects of estrogen, neuronal subtypes that mediate estrogen's anorexigenic effects have not been identified. In this study, we show that changes in hypothalamic expression of agouti-related protein (Agrp) and neuropeptide Y (Npy) coincide with the cyclic changes in feeding across the estrous cycle. These cyclic changes in feeding are abolished in mice with degenerated AgRP neurons even though these mice cycle normally. Central administration of 17β-estradiol (E2) decreases food intake in controls but not in mice lacking the AgRP neurons. Furthermore, E2 treatment suppresses fasting-induced c-Fos activation in AgRP and NPY neurons and blunts the refeeding response. Surprisingly, although estrogen receptor alpha (ERα) is the key mediator of estrogen's anorexigenic effects, we find that expression of ERα is completely excluded from AgRP and NPY neurons in the mouse hypothalamus, suggesting that estrogen may regulate these neurons indirectly via presynaptic neurons that express ERα. This study indicates that neurons coexpressing AgRP and NPY are functionally required for the cyclic changes in feeding across estrous cycle and that AgRP and NPY neurons are essential mediators of estrogen's anorexigenic function.

The Analysis Of Minimum Marriage Age Determination In Indonesia And Other Islamic Countries

2018 ◽  
Vol 16 (2) ◽  
pp. 148
Author(s):  
Nur Azizah
Keyword(s):  
Research Method ◽  
Age Determination ◽  
Marriage Age ◽  
Islamic Country ◽  
Muslim Countries ◽  
The World ◽  
Islamic Countries ◽  
Minimum Age ◽  
Age Of Marriage

The age of marriage is always a polemic in the household. This is based on the view that the age of marriage that is not mature mentally, physically, psychologically, and education is susceptible to unstable attitudes in taking policies or decisions. So that it is feared that they have not been able to respond to problems in the marriage. Indonesia is a country with Muslims as a major population regulating the minimum age of marriage, as well as Muslim countries in the world. The research method used is the juridicalnormative approach. There are someconclusions obtained. First, the Shari'a does not explicitly set a minimum age for marriage, but legal age and understanding are elements that must be fulfilled for prospective brides, and especially for husbands who are positioned as heads of families. Second, every Islamic country, including Indonesia, has different rules regarding the minimum age of marriage, but the purpose of the restriction remains the same, which is to form a partner who is physically and resourcefully ready to build a sakinah household.Keywords: Rules; Age; Marriage

Influence of Temperature on Population Development of Two Color Morphs of the Tobacco Aphid (Homoptera: Aphididae) on Flue-Cured Tobacco

1991 ◽  
Vol 26 (1) ◽  
pp. 33-38 ◽  
Author(s):  
T. David Reed ◽  
Paul J. Semtner
Keyword(s):  
Growth Parameters ◽  
Reproductive Age ◽  
Population Development ◽  
Influence Of Temperature ◽  
Temperature Regimes ◽  
Color Morphs ◽  
Myzus Nicotianae ◽  
Influence Of Temperature On ◽  
Population Growth Parameters ◽  
Tobacco Aphid

Tests were conducted at seven constant temperature regimes in controlled environmental chambers to compare population growth parameters of red and green morphs of the tobacco aphid, Myzus nicotianae Blackman. The optimal temperature for population development of both color morphs was 25°C. At 25°C and above, the red morph had three advantages over the green; most striking was the ability to survive to reproductive age. The red morph also developed faster and was more fecund than the green. Although neither morph reproduced at 32°C, longevity of the red morph was 120% greater. Results of this study may help to explain the disproportionate development of populations of the red morph in the field.

Dating of adularia and the relationship of hydrothermal events in the Lizard complex, Cornwall

1978 ◽  
Vol 115 (3) ◽  
pp. 211-214 ◽  
Author(s):  
A. F. Seager ◽  
F. J. Fitch ◽  
J. A. Miller
Keyword(s):  
Age Determination ◽  
Hydrothermal Activity ◽  
Minimum Age ◽  
Relationship Of ◽  
The Relationship ◽  
Apparent Age ◽  
Hydrothermal Event ◽  
Hydrothermal Veins

SummaryA new total degassing argon-40/argon-39 age determination is given for crystals of fresh adularia from hydrothermal veins within the amphibolites near Porthkerris Point, the Lizard, Cornwall. The apparent age of 211±2 Ma obtained is regarded as a close minimum age for crystallization of the adularia. There appears to have been only one phase of crystallization of primary hydrothermal adularia, about 210–220 Ma, in the granulites and amphibolites in the vicinity of Porthkerris Point and in the gabbro of Dean quarry. Another hydrothermal event occurred c. 160–170 Ma. Younger apparent ages have been attributed to hydrothermal activity at one or more subsequent periods.

The geochronological significance of argon-40/argon-39 age determinations on White Whin from the northern Pennine orefield

1968 ◽  
Vol 307 (1490) ◽  
pp. 251-266 ◽  
Keyword(s):  
Clay Minerals ◽  
Clay Mineral ◽  
Hydrothermal Alteration ◽  
Age Determination ◽  
Hydrothermal Activity ◽  
Work Support ◽  
Natural Isotope ◽  
Minimum Age ◽  
Widespread Phenomenon ◽  
Age Determinations

Controversy regarding the age and character of mineralization in the northern Pennine orefield is reviewed in the context of recent geological and geochronological research in the region, and a number of the unresolved problems are tabulated. A new method of potassium-argon radioisotopic age determination which utilizes the conversion of the natural isotope 39 K in a rock or mineral to the isotope 39 Ar by neutron irradi­ation is described in outline. This method avoids some of the limitations of conventional potassium-argon age determination, and, among other advantages, makes the measurement of the radioages of clay minerals possible. A geochronological and petrological investigation of White Whin samples from the northern Pennine orefield is reported in full, and eighteen new age determinations, mostly upon clay mineral concentrates are presented. The conclusions that can be drawn from this work support a hypothesis of repeated hydrothermal mineralizations within the area of the northern Pennine orefield: the first within the period 284 ± 40 My with subsequent maxima of hydrothermal activity occurring at intervals. At least two of these subsequent episodes have been identified: one around a minimum age of 230 My and another, very important episode occurring around 170 My. Comparison of these results with histograms of (1) all radio­ages of British rocks and (2) radioages from British dolerites and basalts only, suggests that episodic hydrothermal alteration of pre-existing rocks may be a widespread phenomenon in Britain.

scholarly journals Employing Minimum age model (MAM) and Finite mixture modeling (FMM) for OSL age determination of two important samples from Ira Trench of North Tehran Fault

2016 ◽  
Vol 43 (1) ◽  
pp. 38-47 ◽  
Author(s):  
Morteza Fattahi ◽  
Mariam Heidary ◽  
Mohammad Ghasemi
Keyword(s):  
Age Determination ◽  
Mixture Modeling ◽  
Finite Mixture Modeling ◽  
The North ◽  
North Eastern ◽  
Minimum Age ◽  
Age Model ◽  
Osl Age ◽  
Mosha Fault

Abstract Ira trench site is in a point where, the surface trace of North Tehran Fault (NTF) joins the Mosha Fault (MF) in the north-eastern margin of Tehran and can provide important paleosismological information for Tehran. The Ira trench, were divided into 6 packages (I to VI), described, according to their composition, relative and absolute ages. Package I consists of units 23, 25, 26, 27, 28, 29, 30 and 31. The whole package I mainly belongs to Holocene, and provides essential constraints for the recent paleoearthquake activity of the EMF and NTF zone. Therefore, finding accurate ages for the units of this package is very important. Three colluvial wedges (units 23, 26, 28) are present between 20 and 36.5 m north in package I, which are assigned to 3 episodes of activity on Fault 13. Central age model (CAM) provided OSL ages of 35.0 ± 6.1, 7.3 ± 1.3, 6.4 ± 0.9 and 56 ± 6.5 ka for units 23, 26, 28 and 29, respectively. The conflicting ages of 56 ± 6.5 and 35.0 ± 6.1 ka (for units 23 and 29, respectively) as compared to the underlying younger units suggest that these ages are overestimated. MAM provided OSL ages of 13.1 ± 4.3 and 3.5 ± 0.4 ka for units 23 and 29, respectively. The contribution of the new statistical age model of sample IRA4 to the paleoseismic data is discussed.

Cuticular bands as age criteria in the sheep blowfly Lucilia cuprina (Wied.) (Diptera, Calliphoridae)

1974 ◽  
Vol 64 (2) ◽  
pp. 161-174 ◽  
Author(s):  
Marina Tyndale-Biscoe ◽  
R. L. Kitching
Keyword(s):  
Developmental Delays ◽  
Threshold Value ◽  
Accurate Estimate ◽  
Lucilia Cuprina ◽  
Maximum Temperature ◽  
Protein Food ◽  
Maximum Width ◽  
Growth Bands ◽  
Temperature Records ◽  
Oviposition Sites

AbstractIn Lucilia cuprina (Wied.), cuticular bands are deposited most clearly on the mesothoracic post-phragmata, and up to ten such layers can be counted. The bands are deposited clearly only in response to fluctuating temperatures where the minimum temperature in a cycle falls below about 15·5°C. Growth bands are deposited whenever such a change in ambient temperature occurs and the deposition appears to show no inherent rhythmicity. The maximum width of the phragmata is more or less constant and the number of bands which can be distinguished depends upon how quickly the maximum width of the phragmata is reached. The rate of growth of the growth bands and their consequent width depends upon the maximum temperature experienced and the length of time the insect is maintained at that temperature in any cycle. Trials showed that the count of growth bands was an acceptable estimate of the actual age in days when temperatures rose 3·5°C or more above the threshold value of 15·5°C. With a greater temperature range, greater accuracy was achieved. The availability of protein food was shown to have little effect on the deposition of growth bands. A mean age in days was calculated for samples of field-caught flies of a uniformly young ovarian ‘age’ using the counts of growth bands and by working back in the temperature records from their sites of capture using the day-degrees method. Significant differences between the two estimates of age were taken to indicate the occurrence of developmental delays. These were attributable to shortages of protein food in the field and were associated with periods of drought. The method allows the demonstration that developmental delays have occurred but does not provide an accurate estimate of the duration of these delays. It does not permit the confident identification of delays imposed by shortages of oviposition sites.

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