Peripheral androgen levels in the male brush-tail possum (Trichosurus vulpecula)

1985 ◽  
Vol 105 (1) ◽  
pp. 63-70 ◽  
Author(s):  
J. D. Curlewis ◽  
G. M. Stone
Keyword(s):  
Breeding Season ◽  
Sampling Period ◽  
Sampling Procedure ◽  
Seasonal Effect ◽  
Poor Correlation ◽  
Time Intervals ◽  
Progressive Decline ◽  
Collection Period ◽  
Initial Blood ◽  
Androgen Levels

ABSTRACT Radioimmunoassays were established for the measurement of total androgens and the specific measurement of testosterone and 5α-dihydrotestosterone in peripheral plasma of the brush-tail possum. Androgen concentrations were measured in blood collected from indwelling jugular cannulae (i) to determine whether the normal pattern of androgen secretion in this species was episodic and (ii) to attempt to relate total androgen and the pattern of testosterone secretion to the changes previously reported in prostatic, but not epididymal, weight in the breeding season. Blood was collected from restrained animals at varying time-intervals during daylight hours and darkness. Despite an apparent good adaptation to the sampling procedure there was generally a progressive decline in plasma androgen level during the collection period. This was true for animals bled during or out of the breeding season. There was no significant seasonal effect on the androgen concentration in the initial blood sample. When less restraint was used, two of three animals showed fluctuations in androgen levels over the 7-h sampling period. Testosterone levels in blood obtained by cardiac puncture were four- to nine-fold higher than those of 5α-dihydrotestosterone but levels of these androgens in samples obtained during the breeding season were not significantly different from those obtained out of season. The results do not argue for a pulsatile release of testosterone in the possum but do demonstrate a marked capacity for changes in the peripheral androgen concentration. There was a poor correlation between testosterone and 5α-dihydrotestosterone levels and prostatic weight. J. Endocr. (1985) 105, 63–70

THE DURATION OF THE BREEDING SEASON OF FOUR BREEDS OF SHEEP

1974 ◽  
Vol 54 (3) ◽  
pp. 389-392 ◽  
Author(s):  
J. J. DUFOUR
Keyword(s):  
Sexual Activity ◽  
Breeding Season ◽  
Estrous Cycles ◽  
Progressive Decline ◽  
Daily Exposure ◽  
Almost All

Three breeds of sheep (Dorset, Leicester, and Suffolk) and a crossbred line from these breeds (DLS) were observed throughout 1 yr to determine their sexual activity by daily exposure of the ewes to vasectomized rams. The DLS and Dorset ewes exhibited their first estrus earlier in the year (P < 0.01) and stopped cycling later than the Leicester and Suffolk ewes (P < 0.01). The duration of the breeding season in the DLS ewes was 20 days (P > 0.05) longer than in the Dorsets and 70 and 115 days (P < 0.01) longer than in the Leicester and Suffolk ewes, respectively. The percentage of Dorset and DLS ewes showing one or more estrous periods increased progressively from June to reach 100% in September for both breeds. The Suffolk and Leicester ewes commenced to cycle in late August and by September almost all ewes had shown an estrous period. The progressive decline in estrous activity became evident first with the Suffolk in January, then with the Dorset and Leicester in February and with the DLS in March. The Dorset, DLS and Leicester ewes had longer estrous cycles than the Suffolk ewes. Within ewes, length of estrous cycles was highly repeatable for all breeds. False estrus and silent estrus occurred in 1.0 and 3.9% of the estrous periods, respectively. Over successive estrous cycles, length of estrous cycles increased significantly.

scholarly journals Winter Androgen Levels and Wattle Size in Male Common Pheasants

The Condor ◽  
2000 ◽  
Vol 102 (1) ◽  
pp. 193-197 ◽  
Author(s):  
Anna Papeschi ◽  
Federica Briganti ◽  
Francesco DessÌ-Fulgheri
Keyword(s):  
Breeding Season ◽  
Phasianus Colchicus ◽  
Hormone Levels ◽  
Male Trait ◽  
High Level Group ◽  
High Level ◽  
Level Group ◽  
Androgen Levels ◽  
Normally Distributed

Abstract We report the results of morphological and hormonal measurements of 101 male Common Pheasants (Phasianus colchicus) captured during winter and at the beginning of the breeding season in order to identify correlates of ornament size. Androgen levels in January were bimodally distributed with one group with low hormone levels and a second group with high levels. In February, log transformed androgen levels were normally distributed, with all males showing values similar to the high-level group in January. Wattle size was positively correlated with androgens in January but not in February, suggesting that this male trait can indicate the ability of quality males to start earlier androgen production.

scholarly journals Effect of exogenous progesterone treatment on ovarian steroid hormones and oxidant and antioxidant biomarkers during peak and low breeding seasons in dromedary she-camel

2019 ◽  
Vol 12 (4) ◽  
pp. 542-552
Author(s):  
Amal M. Abo El-Maaty ◽  
Ragab H. Mohamed ◽  
Heba F. Hozyen ◽  
Adel M. El-Kattan ◽  
Mona A. Mahmoud ◽  
...  
Keyword(s):  
Steroid Hormones ◽  
Breeding Season ◽  
Management Tool ◽  
Seasonal Effect ◽  
Glutathione S Transferase ◽  
Sod Activity ◽  
Blood Concentrations ◽  
Exogenous Progesterone ◽  
Antioxidant Markers ◽  
Breeding Seasons

Background: Research about the effects of progesterone (P4) and the relationship of P4 to oxidative stress has been achieved in ruminants but not enough in camels Aim: This study evaluated the effect of exogenous P4 hormone using CIDR for 7 days on blood concentrations of steroid hormones and oxidative status of dromedary she-camels during peak and low breeding seasons. Materials and Methods: The present work was conducted on ten dark dromedary she-camels which were synchronized using a controlled internal drug release (CIDR) for 7 days as a reproductive management tool during peak breeding (November-April) and low breeding season (May-October). The blood samples were collected each other day from CIDR insertion until the end of experiment 5 days after the removal of CIDR. Camels were examined for P4, estradiol (E2), and testosterone (T) as well as malondialdehyde (MDA) as indicator of lipid peroxidation and nitric oxide, superoxide dismutase (SOD), and glutathione-S-transferase as antioxidant markers. Results: Results revealed that P4 was higher during peak breeding season than low breeding season. While the levels of P4 increased during CIDR insertion and declined at CIDR removal and thereafter during breeding season, its concentrations declined after CIDR application during the non-breeding season. On the other hand, blood E2 and testosterone levels decreased after CIDR insertion in both high and low breeding seasons with higher serum E2 concentrations during the peak than the low breeding season. MDA concentrations and SOD activities were significantly (p<0.05) high on day 3 after CIDR insertion during the breeding and non-breeding seasons. During both the seasons, GSH levels decreased after CIDR removal in camels. However, MDA was lower during non-breeding season than high breeding season with no seasonal effect on SOD activity. Conclusion: Exogenous P4 treatment through CIDR in dromedary camels could be more efficient during breeding season than non-breeding season, and effects on circulating oxidant/antioxidant biomarkers and their return to normal levels might refer to the adaptation of camels to CIDR by modulating their oxidant and antioxidant levels.

scholarly journals Signal Processing and Sampling Method for Obtaining Time Series Corresponding to Higher Order Derivatives

2010 ◽  
Vol 2010 ◽  
pp. 1-9 ◽  
Author(s):  
Andreea Sterian ◽  
Alexandru Toma
Keyword(s):  
Time Series ◽  
Dynamic System ◽  
Sampling Procedure ◽  
Higher Order ◽  
Time Interval ◽  
Limited Time ◽  
Time Intervals ◽  
Oscillating Systems ◽  
Robust Computation ◽  
Derivatives Of

For modeling and controlling dynamic phenomena it is important to establish with higher accuracy some significant quantities corresponding to the dynamic system. For fast phenomena, such significant quantities are represented by the derivatives of the received signals. In case of advanced computer modeling, the received signal should be filtered and converted into a time series corresponding to the estimated values for the dynamic system through a sampling procedure. This paper will show that present-day methods for computing in a robust manner the first derivative of a received signal (using an oscillating system working on a limited time interval and a supplementary differentiation method) can be extended to the robust computation of higher order derivatives of the received signal by using a specific set of second-order oscillating systems (working also on limited time intervals) so as estimative values for higher-order derivatives are to be directly generated (avoiding the necessity of additional differentiation or amplifying procedures, which represent a source of supplementary errors in present-day methods).

Condition bias of hunter-shot mallards (Anas platyrhynchos)

1986 ◽  
Vol 64 (3) ◽  
pp. 599-601 ◽  
Author(s):  
Hamilton Greenwood ◽  
Robert G. Clark ◽  
Patrick J. Weatherhead
Keyword(s):  
Anas Platyrhynchos ◽  
Sampling Period ◽  
Poor Condition ◽  
Collection Period ◽  
The Mean ◽  
Using Data ◽  
Band Recovery

We tested the hypothesis that hunters using decoys disproportionately shot ducks in poor condition. We compared weights of 316 hunter-shot mallards (Anas platyrhynchos) with those of 156 mallards we collected by jump or pass shooting at a roost. Data were subdivided by age, sex, and sampling period. In support of the hypothesis, in 11 of 12 comparisons, hunter-shot ducks weighed less than ducks collected at the roost and those differences were significant for five of the seven largest samples. Also consistent with the hypothesis, weights of hunter-shot birds were less variable than weights of birds collected at the roost in 9 of 12 comparisons. Through the fall collection period, the mean weight of ducks shot by hunters remained constant, while the weight of ducks sampled at the roost increased by 5.4%. Our results support the argument that caution must be exercised when using data from hunter-shot waterfowl for management programs based on band-recovery analysis or for any other purpose for which a condition bias could influence the interpretation of those data.

Influence of ischemia on tissue androgens in eugonadal and androgen-deprived men treated with prostatectomy.

2013 ◽  
Vol 31 (6_suppl) ◽  
pp. 118-118 ◽  
Author(s):  
Robert B. Montgomery ◽  
Michael Christopher Risk ◽  
Daniel W. Lin ◽  
Alvin M. Matsumoto ◽  
Brett Marck ◽  
...  
Keyword(s):  
Linear Trend ◽  
Clinical Trial Design ◽  
Prostate Tissue ◽  
Lhrh Agonist ◽  
Time Intervals ◽  
Stable Measure ◽  
Ischemic Time ◽  
Treatment Groups ◽  
One Way Anova ◽  
Androgen Levels

118 Background: Optimizing tissue androgen suppression may provide a higher rate of complete pathologic response in patients with localized prostate cancer (PCa). The ability to accurately assess tissue androgens may be influenced by ischemic time and catabolism after devascularization. This study was performed to determine if ischemia influences tissue androgen in eugonadal men and in men treated with various types of neoadjuvant androgen deprivation (ADT). Methods: Eugonadal men (n=12) or men treated with neoadjuvant ADT using LHRH agonist and Casodex or LHRH agonist with Dutasteride, Casodex or all three with Ketoconazole (n=34) underwent prostatectomy for localized PCa. Tissue was acquired by needle biopsy at the time of ligation of the vascular pedicles, at prostate removal and at 30 minutes after prostate removal. Prostate tissue was flash-frozen and tissue dihydrotestosterone (DHT) and testosterone (T) were determined by LC/MS/MS. Change in tissue androgens from clamp was assessed at each time point. Trends in androgen levels were assessed by ANOVA for eugonadal men and within each treatment group Results: Average time from clamp to removal was 23 minutes (± 8) and from removal to subsequent biopsy 32 minutes (± 2). There was no evidence for a significant change in T or DHT over the time intervals tested (one way ANOVA p>0.05 for all measures) except in patients treated with LHRH agonist and Casodex alone. In this group of patients, T declined by 34%by the time of prostate removal, and by 83% at 30 minutes after removal when compared to levels at clamp (one way ANOVA p=0.017, test for linear trend =0.007). In all other treatment groups, both T and DHT were stable for 60 minutes. Conclusions: Assessment of DHT levels in prostate tissue at prostatectomy is not compromised by ischemia. Tissue sampling from 30-60 minutes after vascular clamping yields a stable measure of tissue DHT in the majority of patients. In the absence of SRD5A blockade, testosterone sampling in castrate men is sensitive to ischemia, and delayed sampling underestimates tissue androgen levels due to ischemia-related metabolism. These results lend important insight into clinical trial design and translational endpoints.

The role of season, habitat, host age, and sex on gill parasites of Lepomis gibbosus (L.)

1978 ◽  
Vol 56 (6) ◽  
pp. 1247-1250 ◽  
Author(s):  
George Hanek ◽  
C. H. Fernando
Keyword(s):  
Sampling Period ◽  
Parasite Load ◽  
Seasonal Effect ◽  
Lepomis Gibbosus ◽  
Host Age ◽  
West Lake ◽  
Prince Edward County ◽  
Host Sex ◽  
Gill Parasites ◽  
Age And Sex

One thousand and forty pumpkinseeds (Lepomis gibbosus (L.)) were collected from May 1970 through October 1972 from the Bay of Quinte, Ontario. Also, 1018 specimens of the same host were collected during the same sampling period from West Lake, Prince Edward County, Ontario.Data were collected on three groups of gill parasites, Monogenea (seven species), Copepoda (three species), and glochidia (one species). The data, treated synecologically, were analysed using a two-factor ANOVA and Duncan's multiple range test. The roles of season, habitat, host age, and sex on parasite load were analysed. Host sex was found to have no effect on the three groups of parasites. The abundance of parasites increased with host age (P < 0.001). A marked seasonal effect was noted for all three groups of parasites (P < 0.001), all three being most abundant during the summer period. A eutrophic habitat, West Lake, was found significantly more favourable (P < 0.001) for all three parasitic groups.

Discretizors and Interpolators for Five-Axis CNC Machines

1999 ◽  
Vol 122 (1) ◽  
pp. 191-197 ◽  
Author(s):  
Radha Sarma ◽  
Aarthi Rao
Keyword(s):  
Discrete Time ◽  
Sampling Period ◽  
Cnc Machine ◽  
Time Intervals ◽  
New Techniques ◽  
Cnc Machines ◽  
Complex Curves ◽  
Computer Numerically Controlled ◽  
Five Axis

Discretization and interpolation of curves are two frequently adopted practices when machining complex curves using computer numerically controlled (CNC) machines. Both practices stem from the need to sample curves at discrete time intervals corresponding to the sampling period of the CNC machine. This paper proposes new techniques for discretization and interpolation that account for the change of tool orientations in five-axis machining. First, the method for discretization proposed in this paper is based on sampling the curves such that specified contour, feedrate, and orientation errors are not exceeded. Second, the interpolator proposed in this paper will be able to avoid excessive angular speeds arising from sampling the curves based on the feedrate alone. [S1087-1357(00)01401-5]

scholarly journals Heavy Metals Content in Foliar Litter and Branches of Quercus petraea (Matt.) Liebl. and Quercus robur L. Observed at Two ICP Forests Monitoring Plots

2019 ◽  
Vol 10 (2) ◽  
pp. 151-157
Author(s):  
Srđan Stojnić ◽  
Saša Orlović ◽  
Aleksandar Tepavac ◽  
Lazar Kesić ◽  
Zoran Galić ◽  
...  
Keyword(s):  
Heavy Metals ◽  
Plant Material ◽  
Quercus Robur ◽  
Sampling Period ◽  
Atomic Absorption Spectrophotometry ◽  
Quercus Petraea ◽  
Sampling Procedure ◽  
Natural Forests ◽  
Icp Forests ◽  
Quercus Species

Background and Purpose: Due to the ability to uptake and accumulate heavy metals (HM) in their aboveground tissues, trees may be used for phytoremediation purposes, but also as bioindicators of environmental pollution. The aims of the present study were: a) to investigate the content and temporal variation of the studied HMs in different plant organs during the period of intensive leaf falling (September-October), in two species from genus Quercus; b) to evaluate the observed HMs content relative to plausible ranges of element concentration in foliar litter, as recommended by ICP Forests Foliar Co-ordinating Centre (IFFCC). Material and Methods: The contents of zinc (Zn), manganese (Mn), copper (Cu) and iron (Fe) were assessed in the litterfall (i.e. leaves and branches) of Quercus petraea (Matt.) Liebl. and Quercus robur L. grown at two ICP Forests Level II monitoring plots (Fruška Gora and Odžaci, Serbia). Plant material was sampled during September-October 2018 and analyzed by atomic absorption spectrophotometry. Results: Comparing the content of investigated HMs in foliar litter and branches of Q. robur and Q. petraea, notably higher concentrations of Mn and Fe have been observed in the foliage of both species, whereas Zn and Cu concentrations were higher in collected branch material of both of the above-mentioned tree species. The results further showed that, when compared to plausible ranges of element concentrations in foliar litter, given by ICP Forests Foliar Co-ordinating Centre (IFFCC), average concentrations of Fe and Zn in the leaves were within suggested limits, whereas certain concentrations of Mn and Cu exceeded the proposed ranges. Furthermore, the content of the studied HMs in plant material of both Quercus species significantly varied during sampling period. Conclusions: Although it was observed that concentrations of certain HMs were beyond plausible limits recommended by IFFCC, our results were in accordance with the findings of other authors who studied HMs content in Quercus species grown in natural forests. For that reason, these limits should be considered optionally, i.e. in the cases when the results significantly deviate from the suggested values. Moreover, we believe that the observed variation in the HMs content during sampling period is related to the sampling procedure commonly applied at ICP Forests monitoring plots, which is indirectly associated with the capacity of trees to accumulate HMs and their phenological properties.

scholarly journals Androgen receptors are only present in mesenchyme-derived dermal papilla cells of red deer (Cervus elaphus) neck follicles when raised androgens induce a mane in the breeding season

2001 ◽  
Vol 168 (3) ◽  
pp. 401-408 ◽  
Author(s):  
MJ Thornton ◽  
NA Hibberts ◽  
T Street ◽  
BR Brinklow ◽  
AS Loudon ◽  
...  
Keyword(s):  
Breeding Season ◽  
Cervus Elaphus ◽  
Red Deer ◽  
Androgen Receptors ◽  
Dermal Papilla ◽  
Nuclear Staining ◽  
Dermal Papilla Cells ◽  
High Affinity ◽  
Androgen Binding ◽  
Androgen Levels

Red deer stags produce an androgen-dependent mane of long hairs only in the breeding season; in the non-breeding season, when circulating androgen levels are low, the neck hair resembles the rest of the coat. This study was designed to determine whether androgen receptors are present in deer follicles throughout the year or only in the mane (neck) follicles when circulating testosterone levels are high in the breeding season. Although androgens regulate much human hair growth the mechanisms are not well understood; they are believed to act on the hair follicle epithelium via the mesenchyme-derived dermal papilla. The location of androgen receptors in the follicle was investigated by immunohistochemistry and androgen binding was measured biochemically in cultured dermal papilla cells derived from mane and flank follicles during the breeding season and from neck follicles during the non-breeding season. Immunohistochemistry of frozen skin sections using a polyclonal antibody to the androgen receptor localised nuclear staining only in the dermal papilla cells of mane follicles. Saturation analysis assays of 14 primary dermal papilla cell lines using [(3)H]-mibolerone demonstrated high-affinity, low-capacity androgen receptors were present only in mane (breeding season neck) cells; competition studies with other steroids confirmed the specificity of the receptors. Androgen receptors were not detectable in cells from either the breeding season flank nor the non-breeding season neck follicles. The unusual biological model offered by red deer of androgen-dependent hair being produced on the neck in the breeding, but not the non-breeding season, has allowed confirmation that androgen receptors are required in follicle dermal papilla cells for an androgen response; this concurs with previous human studies. In addition, the absence of receptors in the non-breeding season follicles demonstrates that receptors are not expressed unless the follicle is responding to androgens. Androgen receptors may be induced in mane follicles by seasonal changes in circulating hormone(s).

Sign in / Sign up

Export Citation Format

Share Document