A cascaded two-step Kalman filter for estimation of human body segment orientation using MEMS-IMU.

Orientation of human body segments is an important quantity in many biomechanical analyses. To get robust and drift-free 3-D orientation, raw data from miniature body worn MEMS-based inertial measurement units (IMU) should be blended in a Kalman filter. Aiming at less computational cost, this work presents a novel cascaded two-step Kalman filter orientation estimation algorithm. Tilt angles are estimated in the first step of the proposed cascaded Kalman filter. The estimated tilt angles are passed to the second step of the filter for yaw angle calculation. The orientation results are benchmarked against the ones from a highly accurate tactical grade IMU. Experimental results reveal that the proposed algorithm provides robust orientation estimation in both kinematically and magnetically disturbed conditions.

Immunization of sheep against GnRH early in life: effects on reproductive function and hormones in ewes.

Groups of Merino ewe lambs were immunized against GnRH either soon after birth (prepubertal) or around puberty (peripubertal) with a prototype commercial preparation and were studied over the following 2 years to determine the long-term effects on reproductive development, function and hormone concentrations. At least 60% of the GnRH-immunized ewes in either treatment group did not experience oestrus and possessed small uteri and small ovaries that lacked follicular development. Growth rates of immunized and control ewes were similar throughout the study. Compared with the increase in plasma LH and FSH concentrations with age in control ewes, the concentrations of these hormones in immunized animals were lower and remained relatively constant from 46 to 90 weeks of age. Plasma FSH concentrations were particularly suppressed in immunized ewes and were significantly (P < 0.05) lower than the control values of 61 and 90 weeks of age. LH release after injection of 1 microgram GnRH at 90 weeks of age was either absent or suppressed in immunized ewes compared with controls. The findings suggest that the lack of GnRH stimulation and consequent deprivation of gonadotrophins, early in the life of ewes, may result in some degree of permanent impairment of hypothalamic and/or pituitary function.

Immunization of sheep against GnRH early in life: effects on reproductive function and hormones in rams.

Groups of Merino ram lambs were immunized against GnRH either soon after birth (prepubertal) or around puberty (peripubertal) with a prototype commercial preparation and studied over the following 2 years to determine the long-term effects of such immunization on reproductive development, function and hormone concentrations. The treatment was equally effective in suppressing reproductive function and hormones when given at either time. Growth rates of immunized and controls rams were similar throughout the study. Prepubertal immunization delayed testicular growth until the rams were at least 27 weeks of age and some rams had subnormally sized testes even at 115 weeks of age. After peripubertal immunization, the mass of the testes declined and remained regressed until the rams were from 51 to 90 weeks old. There was a significant correlation between total testicular mass at 115 weeks of age and duration (weeks) of suppression of testicular growth (prepubertal, r = -0.7375; peripubertal, r = -0.7132, P < 0.001). Prepubertal immunization markedly delayed separation of the penis from the prepuce. The immunized rams did not display sexual activity until their total testicular mass reached at least 70 g. In control and immunized rams with testicular mass > 100 g, the semen did not differ in the percentage of spermatozoa that were unstained (live), of normal morphology, or showed progressive movement. Compared with the increase in plasma LH and FSH concentrations with age in control rams, the concentrations of these hormones in the immunized animals were lower and remained relatively constant from 46 to 90 weeks of age.(ABSTRACT TRUNCATED AT 250 WORDS)

Effect of immunization against melatonin on seasonal fleece growth in feral goats.

Four vaccination protocols were utilized to investigate the effects of immunoneutralizing circulating melatonin on the annual cashmere growth cycle and cashmere production in Australian feral goats. A fluctuating anti-melatonin antibody response, achieved by repeated booster vaccinations, resulted in an acceleration of the growth cycle in goats which exhibited a significant immune response, compared to sham-immunized controls. Responding goats showed two cycles of cashmere length growth in the first 16 months and increased annual cashmere production in the first year. However, in the second year, these effects were no longer apparent, suggesting either some form of desensitization to melatonin, or a diminished response due to declining antibody titre. The effects of immunization were observed in both sexes; the effect on cashmere length was greater in wethers than in does. Cashmere fibre growth in response to a continuously declining plane of specific antibody showed increased cycle frequency, albeit with a decreased amplitude; guard hair growth cycles were affected to a much lesser extent. Small transient peaks of specific immunity at the summer or winter solstice were without significant effect on cashmere growth. Immunization to provoke a persistent anti-melatonin antibody response at the winter solstice resulted in significantly increased greasy fleece weight, % cashmere yield, and mass of cashmere produced, but no change in fibre diameter in both sexes. Thus the timing of cashmere growth cycles in goats may be, at least transiently, altered by appropriately timed immunization against melatonin. The mechanism of pineal-mediated regulation of cashmere growth cycles may involve (i) entrainment of an endogenous rhythm by melatonin, or (ii) seasonal alteration of cashmere follicle sensitivity to the effect of melatonin.

A preliminary study of immunological castration in colts.

This study tested the effectiveness of a conjugated GnRH vaccine for stimulating antibody production, suppressing testosterone secretion and depressing testicular development in yearling colts. Two colts were allocated to each of three groups, (1) control, (2) subcutaneous and (3) intramuscular vaccinations. Two injections of the vaccine were given 11 weeks apart. Liveweight gain was not affected by vaccination but plasma testosterone concentrations in the treated colts were suppressed and their antibody titres to GnRH were greater than 1:1000. Testicular development in the treated colts also was retarded at this time, which was approximately 28 weeks after the first injection. Semen samples, containing spermatozoa, were collected from all the colts prior to their castration at the end of the investigation. Antibody titres and testosterone concentrations in the treated colts had returned to levels similar to those of the controls by the end of the experiment. The testes of the vaccinated colts were still smaller than those of the controls on castration but were, nevertheless, increasing in size. Morphometric analysis of testicular histology and daily sperm production data indicated that the testes of the treated colts were recovering and would probably have regained normal function had they been left in situ.

Immunization of ovariectomized ewes against progesterone, oestrogen or cortisol to detect effects of adrenal steroids on reproduction.

Ovariectomized ewes were immunized against cortisol, oestrogen or progesterone to determine whether steroids of non-ovarian origin occur in sufficient amounts to influence the reproductive system. Ewes immunized against oestrogen (oestrone + oestradiol) had smaller uteri (P less than 0.05) and a lower concentration of oestradiol in uterine tissue (P less than 0.05), while the adrenal gland was heavier (P less than 0.05). In the peripheral plasma of immunized ewes, the concentration of FSH, but not LH, was increased (P less than 0.05). Ewes immunized against cortisol also had smaller uteri (P less than 0.05) and heavier adrenal glands (P less than 0.05), but gonadotrophins and the concentration of oestradiol in the uterus were unaffected. Immunization against progesterone, or injection with synthetic glucocorticoids, did not affect any of the characteristics measured. We conclude that the adrenal gland of the ewes produced sufficient oestrogen or aromatizable androgen to have significant effects on the reproductive system. In contrast, adrenal production of progesterone did not produce detectable biological effects. Immunization against cortisol did affect the reproductive system, but the mechanism of this action could not be determined.

Vaxstrate: an anti-reproductive vaccine for cattle.

This paper describes the development of a vaccine for the prevention of pregnancy in female cattle. The vaccine is based on the established principle that antibodies to the hypothalamic releasing hormone, gonadotrophin releasing hormone (GnRH) block the action of GnRH on pituitary secretion of luteinizing hormone and follicle stimulating hormone, leading to gonadal atrophy in mammals. The vaccine comprises an immunogenic GnRH:ovalbumin conjugate formulated in a novel double adjuvant system and is administered in a two-dose treatment regimen. Field trials have confirmed efficacy and the product, Vaxstrate, has now been registered and commercialized.

Gonadotrophin secretion and ovarian responses in prepubertal heifers actively immunized against androstenedione and oestradiol-17 beta.

Groups of heifer calves received a primary immunization against androstenedione (Group A; N = 11) or oestradiol-17 beta (Group E; N = 10) at 3 months of age and booster injections on 5 occasions at 2- to 3-month intervals. Controls (Group C, N = 11) were immunized against human serum albumin alone using the same protocol. Immunity was achieved against both steroids as judged by the secondary antisteroid antibody titres in Group A (1126 +/- 261; reciprocal of titre) and Group E (10,357 +/- 4067) heifers. In Groups A and E there was a general decline in the respective peak antibody titres after successive booster injections. From 3 to 9 months of age mean plasma concentrations of LH were higher (P less than 0.05) in Group E heifers (0.89 +/- 0.08 ng/ml) than in Group C (0.46 +/- 0.03 ng/ml) and Group A (0.59 +/- 0.05 ng/ml) heifers which did not differ from one another. There were no differences between groups in plasma FSH concentrations. At 10 months of age the LH response to exogenous LHRH was of higher (P less than 0.05) amplitude for heifers in Group E (2.59 +/- 0.56 ng/ml) than for those in Groups C (0.61 +/- 0.07 ng/ml) and A (1.04 +/- 0.22 ng/ml). Elevated plasma progesterone concentrations at 5 months of age were shown by 2 heifers in Group C, 10 in Group A, and 6 in Group E. From 8 to 14 months of age a consistently higher proportion of Group A heifers exhibited elevated progesterone compared with Group C and Group E heifers. After ovarian synchronization and booster injection at 15 months of age a corpus luteum was present in 2 heifers in Group C, 7 in Group A and none in Group E. The ovaries of Group A heifers were different from those of Groups C and E and were characterized by greater numbers of 2-4 mm follicles. It is concluded that active immunization against gonadal steroids influences both LH secretion and ovarian function in prepubertal heifers. Early increases in ovarian activity in androstenedione-immunized heifers are maintained after puberty and may therefore confer some lifetime reproductive advantages.

Effect of anti-oestradiol-17B antibodies on the reproductive response of ewes superovulated with PMSG.

A field experiment was conducted to examine the effect of anti-oestradiol-17B antibody titre on the oestrous and ovulatory responses of ewes to low (600 i.u.) or high (1200 i.u.) doses of pregnant mare's serum gonadotrophin (PMSG). Merino ewes were treated with intravaginal sponges and were subsequently used as vehicle-treated controls or were immunized to produce reciprocal anti-oestradiol-17B antibody titres less than 1000 or greater than 1000. Ewes were then treated with PMSG and the incidence of oestrus and ovulation, ovulation rate, and yield of embryos recorded. Treatment of immune ewes with 1200 i.u. PMSG resulted in both a higher proportion of ewes ovulating and a higher ovulation rate than in immune ewes treated with 600 i.u. (86% v. 67% and 13.4 v. 6.0 respectively). As anti-oestradiol-17B titres increased there was a reduction in the proportion of ewes exhibiting oestrus. The proportion of ewes ovulating decreased as antibody increased in ewes treated with 600 i.u. PMSG but not in those treated with 1200 i.u., suggesting an increased positive feedback of oestradiol with high PMSG doses. Fertilization rates were highest at the lower PMSG dose (68% v. 42%) and increased with increasing titre. Overall, there was no increase in ovulation rate or in yield of embryos over control values from either low (less than 1000) or high (greater than 1000) antibody titres.

Ovarian response to PMSG and GnRH in ewes immunised against oestradiol-17 beta.

Forty-six adult merino ewes were immunised against oestradiol-17 beta-6 carbomethyloxime:human serum albumin and 48 comparable ewes were used as controls in an experiment to study the effects of gonadotrophin releasing hormone (GnRH) on ovulatory responses after treatment with pregnant mare's serum gonadotrophin (PMSG). All the ewes were treated with progestogen sponges for 14 days and received 1500 iu PMSG on the 12th day. Twenty-four control and 24 immunised ewes received 25 micrograms GnRH 21.5 hours and 23 hours after the sponges were withdrawn. Plasma samples were collected between 17 and 50 hours after the sponges were withdrawn and assayed for luteinising hormone (LH). Immunisation reduced the proportion of ewes which ovulated and their rate of ovulation. Injection of GnRH increased the proportion of immunised ewes ovulating (P less than 0.0005) and their rate of ovulation (P less than 0.0001). More unovulated follicles were observed in immunised ewes regardless of GnRH treatment (P less than 0.0001). The rate of recovery of eggs was reduced after immunisation. Treatment with GnRH produced a surge of LH of equal magnitude in the control and immunised ewes although not as many immunised ewes ovulated.

Reproductive hormone secretion and testicular growth in bull calves actively immunized against testosterone and oestradiol-17 beta.

Groups of bull calves received a primary immunization against testosterone (Group T; N = 7) or oestradiol-17 beta (Group E; N = 9) at 3 months of age and booster injections on four occasions at approximately 2 month intervals. Controls (Group C, N = 7) were immunized against human serum albumin alone using the same protocol. Immunity was achieved against both steroids as judged by the secondary antisteroid antibody titres in Group T (730 +/- 231; reciprocal of titre) and Group E (12,205 +/- 4366) bulls; however, peak antibody titres generally declined with successive booster injections. Mean plasma concentrations of LH, FSH and testosterone during the period from 3 to 10 months of age were higher (P less than 0.05) in Group T bulls than in Groups C and E. Group T bulls had larger testes compared with controls from 6 months of age onwards. At castration at 14 months of age, testes of Group T bulls were heavier (P less than 0.05) than those of Groups C and E (179 +/- 13, 145 +/- 8 and 147 +/- 6 g, respectively). At 10 months of age, there were no differences among treatment groups in LH responses to LHRH, but the testosterone responses were greater (P less than 0.05) in bulls in Group T (26.2 +/- 4.9 ng/ml) and Group E (16.6 +/- 1.8 ng/ml) compared with those in Group C (6.9 +/- 0.6 ng/ml). Testosterone responses to hCG determined at 13 months of age were also greater (P less than 0.05) in Groups T and E relative to controls. At 14 months of age daily sperm production rates per bull (X 10(-9)) were higher (P less than 0.10) in Group T bulls (2.2 +/- 0.1) than those in Groups C (1.6 +/- 0.2) and E (1.6 +/- 0.1). These results indicate that early immunity against testosterone is associated with increased gonadotrophin secretion and accelerated growth of the testes in prepubertal bulls. Also, chronic immunity against testosterone or oestradiol-17 beta enhances the steroidogenic response of bull testes to gonadotrophic stimulation. If the above responses observed in young bulls are shown to be sustained, then immunity against gonadal steroids early in life may confer some reproductive advantage in mature animals.

Effect of immunization against progesterone on oestrus, cycle length, ovulation rate, luteal regression and LH secretion in the ewe.

The effects of active immunization against progesterone on reproductive activity were studied in Merino ewes. Immunization against progesterone caused a shortening (P less than 0.01) of the interval between ovulations from 17-18 days (controls) to between 6 and 10 days (immunized group); this was associated with a corresponding reduction in the interval between LH surges. The immunized ewes also had higher (P less than 0.05) ovulation rates (1.72) than controls (1.25) and exhibited a reduced (P less than 0.01) incidence of oestrus (26% v. 95%). Many immunized ewes continued to ovulate despite the persistence of corpora lutea from earlier ovulations which led to an accumulation on the ovaries of many corpora lutea of different ages. The frequency of LH pulses in ewes immunized against progesterone (1.8 +/- 0.2 pulses/4 h) was significantly (P less than 0.001) higher than that of control ewes (0.3 +/- 0.1 pulses/4 h). This study highlights the importance of progesterone in the control of oestrus, ovulation, ovulation rate, luteal regression and the secretion of LH in the ewe.

Fertilization and early embryonic development in androstenedione-immunized Merino ewes.

Ewes were immunized against androstenedione (Fecundin) and assigned to be mated 14 days (179 ewes Group C) or 25 days (174 ewes Group B) after a booster immunization with Fecundin. The anti-androstenedione titres at these times were 6790 and 3240 respectively (P less than 0.01). The remaining 169 ewes were untreated controls (Group A). Ewes were mated to entire rams (12 rams to 180 ewes) at their second oestrus after synchronization of oestrus. Immunization against androstenedione caused a shortening of the time from sponge removal to mating (Day 0) and a decrease in the percentage of ewes mated by the rams. Also, ovulation rate was increased after immunization (P less than 0.01), being 1.42, 2.16 and 1.93 for Groups A, C and B respectively. Egg recovery rates on Day 2 were lower in immunized ewes and there was some indication that fertilization rates were lowered. On Day 13 after mating a higher proportion of blastocysts was recovered from ewes in Group A than from those in Groups B and C. Immunization resulted in lower fertilization rates and smaller blastocysts with lower mitotic indexes (P less than 0.01). At Days 24-32 of pregnancy fetal weight was lower in the immunized ewes. At all sampling stages, the proportion of ewes pregnant (fertility) was lowered in immunized ewes. The results of the present study show that significant reproductive wastage occurs in androstenedione-immunized Merino ewes, with lower rates of embryo recovery and delayed embryonic development being found in comparison to controls.(ABSTRACT TRUNCATED AT 250 WORDS)

Polyploid cells in blastocysts and early fetuses from Australian Merino sheep.

Cytogenetic examination was made of 103 13-14-day-old blastocysts and 116 24-32-day-old fetuses from untreated and androstenedione-7-HSA-immunized Merino ewes. There were no differences in the chromosome composition of blastocysts or fetuses from treated or untreated ewes and so the data were combined. At Days 13-14 a 1N/2N mosaic and a 2N - 1/2N/4N mosaic embryo were observed. In addition, 52 of the blastocysts were 2N/4N mosaics, with 8 of these also containing 8N cells, and one blastocyst was a 2N/8N mosaic. No aneuploid fetuses were observed, but 80 of the 116 fetuses contained polyploid cells, including 4N, 6N and 8N cells. The polyploid cells observed in the blastocysts and fetuses should not be considered as abnormal cells as they appear to be a normal part of the developmental processes leading to trophoblast formation and fetal differentiation.

Use of a styrene-maleic anhydride copolymer as an adjuvant with testosterone-serum albumin immunogens and its application to increasing ovulation rate in the ewe.

A synthetic poly(styrene-maleic anhydride) copolymer of average molecular weight 470,000 potentiated a testosterone-binding antibody response during immunization of sheep with immunogenic testosterone-3-carboxymethyloxime-serum albumin conjugates. The copolymer had weaker immunostimulatory activity than Freund's complete adjuvant (FCA). The minimum effective dose of the copolymer was about 30 mg at which secondary but not primary immune responses could be detected by radioimmunoassay. There was a generally weak anamnestic response in immune sheep as secondary and teritary responses tended to decline promptly from peak values; tertiary antibody titres usually did not exceed secondaries. The use of the copolymer as a solution or emulsion had no apparent effect on its immunoadjuvant activity when administered intramuscularly but the soluble form was inactive when given intraperitoneally. The testosterone-binding antibody that was produced using either the copolymer or FCA had considerable sensitivity to deactivation by mercaptoethanol. The ovulation rate of a group of 20 Merino ewes following immunization with testosterone-serum albumin using the copolymer adjuvant was significantly higher than an equal group of untreated control ewes.

Seasonal changes in the sensitivity of ovine pineal beta-adrenoceptors to steroids.

Immunoneutralization of endogenous gonadal steroids has recently been shown to modify pineal beta-adrenoceptor function in intact Merino ewes. In the current study, interactions between gonadal steroids and these receptors have been further investigated. beta-Adrenoceptor density and binding affinity both showed time-related changes in ewes; the significance of these changes requires further study. Two observations, firstly modification of beta-adrenoceptor function by androstenedione and 17 beta-estradiol in ovariectomized, but not in intact ewes, and secondly that steroid-mediated effects on receptor density and binding affinity in the pineal of ovariectomized Merino ewes could be demonstrated during anestrus, but not during the breeding season for intact ewes, indicate that gonadal steroids may regulate pineal beta-adrenoceptor variables in Merino ewes. It is suggested that gonadal steroids may regulate ovine pineal function in ewes, and that the seasonal differences in sensitivity of luteinizing hormone release to steroid feedback may be mediated in part via effects on the pineal gland.

Occurrence of haploid and haploid/diploid mosaic embryos in untreated and androstenedione-immune Australian Merino sheep.

Chromosome counts were obtained from 73 out of 177 (41%) early cleavage-stage Merino embryos. A further 13 embryos were classified as probably diploid. Chromosome aberrations were found in 8 (11%) embryos, one of which was aneuploid and the remainder (9.6%) had euploid abnormalities. If the probable diploid embryos are included, the incidence of euploid aberrations falls to 8.1%. Of the abnormal embryos there was one aneuploid with 2N = 55, two haploids, four haploid/diploid mosaics and one zygote with 4 haploid metaphase plates. Two additional zygotes had 4 interphase pronuclei. Four of the euploid abnormalities were attributable to the entry of two or more spermatozoa and therefore polyspermy is the largest single factor leading to chromosomally aberrant embryos in this population of Merino ewes.

Ovarian response to PMSG treatment in ewes immunized against oestradiol-17 beta.

The effects of active immunization against oestradiol-17 beta on the ovarian response to pregnant mare serum gonadotrophin (PMSG) was investigated in Merino ewes. Immunized (79) and control (41) ewes were synchronized with intravaginal sponges, given either 750 or 1500 i.u. PMSG and then mated to rams or inseminated laparoscopically with fresh diluted semen. All control ewes mated naturally exhibited oestrus and 40 out of 41 control ewes ovulated. The ovulation rate was higher in the controls receiving 1500 i.u. PMSG than in those ewes which received 750 i.u. PMSG (10.2 v. 3.3). Immunization against oestradiol-17 beta resulted in antibody titres varying from 100 to more than 100 000 in plasma taken 1-4 days after mating. The ovarian response increased significantly in the lowest titre group (100-1000) in conjunction with stimulation with 1500 i.u. PMSG. In these ewes the ovulation rate increased over controls (16.7 v. 10.2) as did the total ovarian response, which includes follicles greater than 10 mm diameter (22.3 v. 11.1). The total ovarian response was also increased in those ewes given 750 i.u. PMSG which had titres in the 1000-10 000 and 10 000-100 000 range, but this was not accompanied by significant increases in the ovulation rate. In general, the higher titre levels (greater than 1000) were correlated with decreases in the proportion of ewes showing oestrus and ovulating and in the embryo recovery rate. The 1500 i.u. PMSG treatment group with the highest titres (greater than 10 000) also showed a significant drop in the ovulation rate as compared to the 1500 i.u. PMSG controls.