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While foraging or during social interactions, animals may benefit from judging relative quantity. Individuals may select larger prey or a patch with more food and, likewise, it may pay to track the number and type of individuals and social interactions. We tested for spontaneous quantity discrimination in the gidgee skink (Egernia stokesii), a family-living lizard. Lizards were presented with food quantities differing in number or size and were able to select the larger quantity of food items when they differed in number but not when items differed in size. We show, for the first time, superior spontaneous discrimination of items differing in number over size in a lizard species, which contrasts with previous findings. Our simple method, however, did not include controls for the use of continuous quantities, and further tests are required to determine the role of such information during quantity discrimination. Our results provide support for the use of the parallel individuation system for the discrimination of small quantities (four or fewer items). Lizards might, however, still use the approximate number system if items in larger quantities (more than four) are presented. Overall, we uncovered evidence that species might possess specific cognitive abilities potentially adapted to their niche with respect to quantity information (discrete and/or continuous) and the processing system used when judging quantities. Importantly, our results highlight the need for testing multiple species using similar testing procedures to gain a better understanding of the underlying causes leading to differences across species.

While foraging or during social interactions, animals may benefit from judging relative quantity. Individuals may select larger prey or a patch with more food and, likewise, it may pay to track the number and type of individuals and social interactions. We tested for spontaneous quantity discrimination in the gidgee skink (Egernia stokesii), a family-living lizard. Lizards were presented with food quantities differing in number or size and were able to select the larger quantity of food items when they differed in number but not when items differed in size. We show, for the first time, superior spontaneous discrimination of items differing in number over size in a lizard species, which contrasts with previous findings. Our simple method, however, did not include controls for the use of continuous quantities, and further tests are required to determine the role of such information during quantity discrimination. Our results provide support for the use of the parallel individuation system for the discrimination of small quantities (four or fewer items). Lizards might, however, still use the approximate number system if items in larger quantities (more than four) are presented. Overall, we uncovered evidence that species might possess specific cognitive abilities potentially adapted to their niche with respect to quantity information (discrete and/or continuous) and the processing system used when judging quantities. Importantly, our results highlight the need for testing multiple species using similar testing procedures to gain a better understanding of the underlying causes leading to differences across species.

Objective To study the effects of antenatal perineal massage on subsequent perineal outcomes at delivery. Design A randomised, single-blind prospective study. Setting Department of Obstetrics and Gynaecology, Watford General Hospital. Participants Eight hundred and sixty-one nulliparous women with singleton pregnancy and fulfilling criteria for entry to the trial between June 1994 and October 1995. Results Comparison of the group assigned to massage with the group assigned to no massage showed a reduction of 6.1% in second or third degree tears or episiotomies. This corresponded to tear rates of 75.1% in the no-massage group and 69.0% in the massage group (P= 0.073). There was a corresponding reduction in instrumental deliveries from 40.9% to 34.6% (P= 0.094). After adjustment for mother's age and infant's birthweight these reductions achieved statistical significance (P= 0.024 and P= 0.034, respectively). Analysis by mother's age showed a much larger benefit due to massage in those aged 30 and over and a smaller benefit in those under 30. Conclusion Antenatal perineal massage appears to have some benefit in reducing second or third degree tears or episiotomies and instrumental deliveries. This effect was stronger in the age group 30 years and above.

Waterbirth is an increasingly popular choice for women. There are approximately 300 waterbirths at the Edgware Birth Centre each year. Trusts need to have robust evidence-based guidelines in place and there is now a great deal of evidence about this way of birth. Waterbirth dopplers are essential equipment to enable fetal monitoring which is comfortable for the mother and convenient for the midwife. A torch and mirror are also useful tools for the midwife and mother as they encourage the essential hands-off technique required for this type of birth. Workshops are useful ways to inform parents about the advantages and disadvantages of waterbirth. Midwives need to be trained in this technique and workshops and reflection are useful ways to support and inform midwives.

SUMMARYResearch into the mechanisms that control the initiation and development of wool follicles has been severely hampered by the inaccessibility of fetal skin in utero. The aims of this study were to determine whether ovine fetal skin, when grafted onto the athymic nude mouse (nu/nu), could be maintained outside the uterine environment and, if so, whether it would retain its ability to initiate and develop wool follicles capable of producing wool fibres.Skin was removed from the mid-side region of ovine fetuses on days 45, 55, 65, 75, 85 and 95 of gestation, and transferred to graft beds prepared on anaesthetized nude mice. After developing for 20 days on the recipients, the grafts were excised for histological examination. Control ovine fetal skin was also obtained at the above times and from fetuses on days 105 and 115, and similarly processed for histological examination.Fetal skin at all ages was successfully grafted onto nude mice; 90% of all grafts were accepted and maintained by the recipients. Follicle initiation and/or development occurred in all grafts, including those formed from day 45 fetal skin, collected and grafted prior to follicle initiation in vivo. The number of follicles in grafted skin was reduced compared to that in control fetal skin of equivalent age; however, follicle development was generally accelerated. Follicle initiation and development occurred predominantly in the peripheral zone of the grafts. Some of the follicles present in the skin at grafting were lost due to the grafting procedure, while others continued to develop and produce wool fibres. Follicle development varied considerably between grafts. All grafted skin exhibited premature loss of the periderm layer and cornification of the epidermis, probably in response to the exposure of the skin surface to the atmosphere. There was a notable absence of both arrector pili muscles and sweat glands associated with graft follicles, and a retardation of sebaceous gland development.The grafting technique developed in this study has enabled ovine fetal skin to be maintained outside the uterine environment for extended periods of time and may provide an improved means for future investigation of wool follicle initiation and development.

SUMMARYThe study investigated the effects of chronic elevation or suppression of circulating prolactin levels on seasonal wool growth in Romney sheep. Ewes (n = 10/group) were housed indoors under natural lighting (latitude 34 °S) and received either 50 mg bromocriptine i.m./ewe/28 days (Group B), 1 mg spiperone s.c./ewe/day (Group S) or no treatment (Group C) commencing in summer. Wool growth and liveweight were measured every 4 weeks and venous blood samples were collected for prolactin determination. Plasma prolactin levels (mean±s.E.) in Group C exhibited a gradual seasonal decline from 121±29 ng/ml to 35±9 ng/ml. Bromocriptine suppressed prolactin levels rapidly from a pretreatment value of 118±2 ng/ml to below 12±7 ng/ml for the duration of the study. Prolactin levels in Group S were not significantly higher than Group C, with the exception of the first 14 days following the initial treatment. A seasonal reduction in wool growth of c. 25% was observed in all groups; however, no significant treatment effect was evident. Mean liveweight of all animals increased from 50·4±0·8 to 56·8±0·7 kg during the study. These results indicate that perturbation of the annual cyclic secretion of prolactin does not affect wool growth in the Romney ewe.

Recent studies from within our laboratory have demonstrated a causal relationship between capacitation-associated surface phosphotyrosine expression and the ability of mouse spermatozoa to recognize the oocyte and engage in sperm-zona pellucida interaction. In the studies described herein we have sought to investigate the signaling pathways that underpin the tyrosine phosphorylation of sperm surface protein targets and validate the physiological significance of these pathways in relation to sperm-zona pellucida adhesion. Through selective pharmacological inhibition we have demonstrated that surface phosphotyrosine expression is unlikely to be mediated by the canonical cAMP-dependent protein kinase A (PKA) signaling cascade that has been most widely studied in relation to sperm capacitation. Rather, it appears to be primarily driven by the extracellular signal-regulated kinase (ERK) module of the mitogen-activated protein kinase (MAPK) pathway. Consistent with this notion, the main components of the ERK module (RAS, RAF1, MEK, and ERK1/2) were localized to the periacrosomal region of the head of mature mouse spermatozoa and their phosphorylation status within this region of the cell was positively modulated by capacitation. Furthermore, inhibition of several elements of this pathway suppressed sperm surface phosphotyrosine expression and induced a concomitant reduction sperm-zona pellucida interaction. Collectively, these data highlight a previously unappreciated role of the ERK module in the modification of the sperm surface during capacitation to render these cells functionally competent to engage in the process of fertilization.

Ortho‐ and paracortex can be differentiated in wool fibres by a methylene blue staining procedure. The procedure, though effective, is slow and tedious because of the method currently used for fibre preparation. The aim of this study was to simplify the fibre preparation technique. Wool fibre bundles, obtained from midside wool samples, were cleaned in solvent and dried. Cotton thread was tied to the tip of each fibre bundle which was then drawn through a length of fine Silastic tubing. The bundles were hardened by firstly soaking in nitrocellulose then chloroform. The tubing was removed from around the bundles, and the fibre bundles were dried, trimmed, and cut into lengths (10 mm) which were then immersed in molten paraffin, embedded in paraffin blocks, and sectioned. The fibre sections were stained using a methylene blue staining protocol. This technique has proved to be an efficient and effective means of identifying regions of ortho‐ and paracortex within wool fibres.

This study was undertaken to determine if there is a relationship between the fibre diameter measurement obtained from a skin section and that obtained from the corresponding wool fibres. A skin biopsy (1 cm diam.) was taken from the undipped midside of 29 fme‐woolled Merino sheep, under local anaesthetic. The fibres protruding from the biopsy were severed at the skin surface and fibre diameter measurements determined at intervals along their length. Fibre diameter was also measured in the skin sections prepared from the biopsies. The fibre diameter (mean ± SEM) from the skin sections (15.0 ± 0.2 μm) was significantly lower (P < 0.001) than the mean wool fibre diameter (19.2 ± 0.2 μm). Fibre diameters measured along the fibre bundles were highly correlated (0.81–0.88), whereas the correlations between fibre diameter from skin sections and wool were much lower (0.64). The lower fibre diameter obtained from skin sections is likely to result from the effect of sample preparation, though the effect o...

The length growth rate of fleece is routinely determined by measuring the length of wool grown between two bands of dye, each applied to the fleece at skin level at different times, normally weeks apart. The routine procedure uses a Durafur Black R dye solution, which can produce thick dye bands and may pose a health risk to both the operator and the sheep. The aim of this study was to develop a method for producing fine dye bands in wool, using a non‐toxic dye. Two 5 cm dye bands, one using Durafur Black R dye solution and the other using Schwarzkopf® hair dye cream were applied to the right midside of 14 Merino and 14 Border Leicester × Merino sheep. The dyes were applied at skin level, 9 weeks apart, from a 10 ml syringe using a shortened 21 gauge needle. The dye bands were removed at skin level 4 weeks following the application of the second dye band. The results of the study indicate that hair dye cream was easier and quicker to prepare and apply than the Durafur Black R dye solution, and pr...

A rapid method of excising skin biopsies, from skin blebs formed by a subcutaneous injection of anaesthetic, was investigated to determine the effect on wool follicle density measurements. Two biopsies were taken from the midside of 28 sheep using a trephine, one directly over the skin bleb and the second adjacent to it. Biopsy shrinkage as a result of fixation and histological processing was measured. Total follicle densities were determined and adjusted for biopsy shrinkage using a correction factor (area of skin section/area of the trephine). Biopsies taken over blebs had a greater sectional area (c. 9.3%) most likely because of distension of the skin during the collection of the biopsy, in comparison with their paired biopsy. This increase in the area of skin sampled, resulted in inaccurate correction factors and consequently artificially increased (c. 7.3%) follicle density measurements in biopsies sampled over blebs. The results of this study indicate that inaccurate follicle density measur...

There is evidence to indicate that pinealectomy may enhance wool growth in the sheep. The aim of this study was to determine the effect of pinealectomy on wool growth and wool follicle density in Merino sheep. Castrated Merino rams (4 months old) were either pinealectomized (P), sham-pinealectomized (S) or not treated (C). Wool growth on mid-side patches was measured every 4 weeks and follicle density was monitored in skin biopsies collected before treatment and at regular intervals for 60 weeks. Venous blood samples were taken on each of these occasions for prolactin analysis. Melatonin concentrations were determined in venous blood collected pre- and posttreatment from samples taken over a 24-hr period during the winter solstice. Pre- and posttreatment plasma melatonin levels (mean +/- SEM) 65 +/- 17 and13 pg/ml for P, 86 +/- 21 and 69 +/- 20 pg/ml for S, and 94 +/- 41 and 122 +/- 37 pg/ml for C, respectively, indicated that the pineal glands had been successfully removed. Wool growth, total follicle density and liveweight (mean +/- SEM) did not differ between treatment groups. Measurements at week 60 were 3.9 +/- 0.3, 4.1 +/- 0.2, and 3.8 +/- 0.3 gm clean wool/100 cm2; 66 +/- 6, 69 +/- 7, and 64 +/- 3 follicles/mm2; and 50.4 +/- 1.3, 50.8 +/- 1.4, and 52.6 +/- 1.1 kg liveweight for groups P, S, and C, respectively.(ABSTRACT TRUNCATED AT 250 WORDS)

The fleece of the Merino sheep is composed predominantly of wool fibres grown from secondary wool follicles. This study investigates the effects of melatonin and prolactin on the development of secondarv follicles in grafted ovine foetal skin. Skin from day 85 ovine foetuses was grafted onto nude mice, developed for 40 days and then excised. Mice received either 30 8g prolactin ip mouse-1 day-1 (P), one melatonin implant (Regulin�) sc mouse -1 (M), commencing at grafting or no further treatment (C). Wool follicle density and development were assessed in grafted skin and compared with day 125 control foetal skin. Cuticle structure of graft fibres was also examined and compared with those of day 125 foetuses. Total follicle density and the rate of follicle initiation were reduced in the grafts compared with control foetal skin. Total follicle density did not vary significantly between treatments, but the number of derived secondary follicles was greater in grafts from mice receiving prolactin (group P). Follicles in grafted skin were larger, produced medullated fibres, and were not grouped, in comparison with follicles in the control foetal skin. Epidermal thickness was greater in grafts than in control foetal skin. The cuticle structure of graft fibres from all groups was similar to the control wool fibres. These findings indicate that prolactin, but not melatonin, may be involved in the regulation of derived secondary follicle development.

The physiological role of placental lactogen (PL; chorionic somatomammotrophin) in the ewe has been investigated by infusion of ewes (n = 3) on day 131 of pregnancy with sufficient ovine PL (oPL) antibody to neutralize circulating oPL for at least 12 h. Effectiveness of the antibody neutralization was defined both in vitro and in vivo according to rigorous criteria. Control ewes (n = 3) were infused simultaneously with an equivalent amount of pooled goat gamma globulin. Since both sets of ewes had previously been catheterized with jugular, utero-ovarian and femoral vein catheters and a femoral arterial catheter, it was possible to measure whole body glucose kinetics as well as muscle and uterine glucose, free fatty acid (FFA) and 3-hydroxybutyrate extraction. In addition, plasma levels of insulin, GH, prolactin, insulin-like growth factor-I (IGF-I), IGF-II, progesterone and cholesterol were determined in femoral arterial samples. Neutralization of maternal oPL did not significantly affect whole body glucose metabolism, uterine and muscle glucose extraction, or 3-hydroxybutyrate extraction by muscle. A trend towards lower plasma FFA levels was observed after prolonged infusion, but was not statistically significant. However, plasma insulin levels rose significantly during antibody infusion after an early fall. These observations are rationalized in terms of the known requirements of ruminant metabolism during pregnancy, and contrasted with the accepted model for the role of human PL in the metabolic adjustments of pregnancy. No change in plasma IGF-I, IGF-II or GH was observed, providing no support for the concept that oPL is responsible for maternal somatomedin generation during pregnancy. Similarly, plasma prolactin did not differ between antibody-treated and control groups. Finally, antibody neutralization had no influence on either plasma progesterone or cholesterol, mitigating against a role for oPL in progesterone production during late pregnancy in the ewe. J. Endocr. (1985) 106, 377–386

An investigation of 1088 unrelated British people to look for an association between alleles of the Rhesus blood group system and those of the Gm system gave the result expected for totally independent loci.