The effect of dietary antioxidants on lipofuscin accumulation in the crustacean brain

Lipofuscin accumulation is associated with ageing at the subcellular level. A strong correlation between lipofuscin and age has been found in crustaceans using histological techniques. This association has been proposed as the basis for a methodology to age crustaceans and in some cases lipofuscin levels were found to be better correlated with age than size. The experiment presented here was designed to test the potential effect of diet, in particular dietary antioxidants, on lipofuscin accumulation and age estimation.The shrimp, Penaeus japonicus, was reared in an aquaculture facility and fed commercial pellets with modified vitamins C and E contents. One group was fed with levels of vitamins C and E of 1000 and 150 mg/kg, respectively, and another group with 2500 and 5000 mg/kg, respectively. The experiment started when the shrimp were 19 weeks old. Samples were obtained at this point and at ages 33 and 43 weeks. Lipofuscin was measured in the nerve cords (antennal neuropils and oesophageal connectives) in an area adjacent to the brain.Dietary antioxidants significantly affected lipofuscin levels. High vitamin content in the diet resulted in lower percentage of the observed area covered with lipofuscin, lower lipofuscin granule density and lower average granule size. Gender had no effect on any of these variables and granule size did not significantly change within each treatment. Lipofuscin area and granule density increased with age in both vitamin treatments.These results suggest that age estimation using lipofuscin indices may be biased when: (1) wild populations are dispersed over diverse environments; (2) the age estimation of wild individuals is based on the results obtained using laboratory-reared individuals.     

Structure and luminescence of copper(I) cyanide-amine and -sulfide networks

Copper(I) cyanide reacts with various liquid amines and sulfides (L) under solvent-less conditions to form (CuCN)L_n, n = 0.5, 0.57, 0.75, 0.8, 1, 1.25, 1.5, 2. New X-ray structures are reported for L = Py (Py = pyridine, n = 0.57), 2-MePy (n = 1), 3-EtPy (n = 1.5), 2-ClPy (n = 1), 3-ClPy (n = 2), 3-MeOPy (n = 2), 4-^tBuPy (n = 1.5), piperidine (n = 1.25), N-methylmorpholine (n = 1), N,N-dimethylcyclohexylamine (n = 1), 1-methylimidazole (n = 3), Me₂S (n = 1), and tetrahydrothiophene (n = 1). The amine structures (except for the monomeric 1-methylimidazole complex) reveal 1D CuCN chains decorated with 0-2 L per metal atom. Chain structures observed include zigzag, helical and figure-8 helical. The CuCN-sulfide structures show sulfur-bridging of CuCN chains. In some cases (CuCN)L_?1.5 species are transformed to (CuCN)L under vacuum. Thermal analysis shows facile release of ligand, yielding CuCN. Most of the (CuCN)L_n products are photoluminescent, emitting in the visible region. In some cases, coordination of very similar amines results in remarkably different emission spectra.     

Estimation of nuclear DNA content in Nasturtium R. Br. by flow cytometry

The most common and widespread species of Nasturtium in central Europe are the tetraploid Nasturtium officinale (2n = 4x = 32), the octoploid Nasturtium microphyllum (2n = 8x = 64), and their hexaploid hybrid Nasturtium × sterile (2n = 6x = 48). For the first time, flow cytometry was used to measure the genome size (2C DNA content) of these taxa. The highest nuclear DNA content was found in the octoploid N. microphyllum (2C = 1.43 pg) and the lowest in the tetraploid N. officinale (2C = 0.76 pg). Some differences in the amount of nuclear DNA were observed for the hexaploid N. × sterile (2C = 1.09-1.12 pg). Genome size analysis was thus proposed as a very useful tool for the identification of species of Nasturtium in their vegetative stage.     

Group size, sex and age composition of chital (Axis axis) and sambar (Rusa unicolor) in a deciduous habitat of Western Ghats

Knowledge of the social structure of a population is important for a range of fundamental and applied purposes. Group characteristics and population structure of chital (Axis axis) and sambar (Rusa unicolor) were studied in a deciduous habitat of Mudumalai Tiger Reserve, Western Ghats, India, during 2008-2009. Vehicle transects were monitored monthly to gather information on group-size and age-sex composition of chital and sambar. The average mean group size and crowding for chital and sambar was 13.1 ± 0.5 (n = 1020), 3.6 ± 0.2 (n = 377) and 33.3, 11.0 respectively. The average adult male:adult female:fawn ratio was 63.4:100:22.3 (n = 9391) and 43.9:100:23.7 (n = 1023) in chital and sambar respectively. The mean group size of chital and sambar varied significantly between seasons (Kruskal-Wallis test, p = <0.001). Peak fawning season was observed from February to May for chital and May to August for sambar. Group's sex-age composition influenced group formation in both species between seasons at different level. Adult male and fawn were the important predicting variables of change in group size. Skewed female sex ratio was probably due to selective male predation by large predators. Although fawning occurred throughout the year, both species showed seasonality in fawning. The above mentioned patterns differed between species depending upon their ecological adaptation in foraging strategies and habitat preference.     

Heat tolerance, behavioural temperature selection and temperature-dependent respiration in larval Octopus huttoni

This study reports temperature effects on paralarvae from a benthic octopus species, Octopus huttoni, found throughout New Zealand and temperate Australia. We quantified the thermal tolerance, thermal preference and temperature-dependent respiration rates in 1-5 days old paralarvae. Thermal stress (1 °C increase h⁻¹) and thermal selection (∼10-24 °C vertical gradient) experiments were conducted with paralarvae reared for 4 days at 16 °C. In addition, measurement of oxygen consumption at 10, 15, 20 and 25 °C was made for paralarvae aged 1, 4 and 5 days using microrespirometry. Onset of spasms, rigour (CT_max) and mortality (upper lethal limit) occurred for 50% of experimental animals at, respectively, 26.0±0.2 °C, 27.8±0.2 °C and 31.4±0.1 °C. The upper, 23.1±0.2 °C, and lower, 15.0±1.7 °C, temperatures actively avoided by paralarvae correspond with the temperature range over which normal behaviours were observed in the thermal stress experiments. Over the temperature range of 10 °C-25 °C, respiration rates, standardized for an individual larva, increased with age, from 54.0 to 165.2 nmol larvae⁻¹ h⁻¹ in one-day old larvae to 40.1-99.4 nmol h⁻¹ at five days. Older larvae showed a lesser response to increased temperature: the effect of increasing temperature from 20 to 25 °C (Q₁₀) on 5 days old larvae (Q₁₀=1.35) was lower when compared with the 1 day old larvae (Q₁₀=1.68). The lower Q₁₀ in older larvae may reflect age-related changes in metabolic processes or a greater scope of older larvae to respond to thermal stress such as by reducing activity. Collectively, our data indicate that temperatures >25 °C may be a critical temperature. Further studies on the population-level variation in thermal tolerance in this species are warranted to predict how continued increases in ocean temperature will limit O. huttoni at early larval stages across the range of this species.     

Distribution of repetitive DNA sequences in chromosomes of five opisthorchid species (Trematoda, Opisthorchiidae)

Genomes of opisthorchid species are characterized by small size, suggesting a reduced amount of repetitive DNA in their genomes. Distribution of repetitive DNA sequences in the chromosomes of five species of the family Opisthorchiidae (Opisthorchis felineus 2n = 14 (Rivolta, 1884), Opisthorchis viverrini 2n = 12 (Poirier, 1886), Metorchis xanthosomus 2n = 14 (Creplin, 1846), Metorchis bilis 2n = 14 (Braun, 1890), Clonorchis sinensis 2n = 14 (Cobbold, 1875)) was studied with C- and AgNOR-banding, generation of microdissected DNA probes from individual chromosomes and fluorescent in situ hybridization on mitotic and meiotic chromosomes. Small-sized C-bands were discovered in pericentric regions of chromosomes. Ag-NOR staining of opisthorchid chromosomes and FISH with ribosomal DNA probe showed that karyotypes of all studied species were characterized by the only nucleolus organizer region in one of small chromosomes. The generation of DNA probes from chromosomes 1 and 2 of O. felineus and M. xanthosomus was performed with chromosome microdissection followed by DOP-PCR. FISH of obtained microdissected DNA probes on chromosomes of these species revealed chromosome specific DNA repeats in pericentric C-bands. It was also shown that microdissected DNA probes generated from chromosomes could be used as the Whole Chromosome Painting Probes without suppression of repetitive DNA hybridization. Chromosome painting using microdissected chromosome specific DNA probes showed the overall repeat distribution in opisthorchid chromosomes.     

Assessing the validity of stylets as ageing tools in Octopus pallidus

A method to age octopus was determined through the quantification of growth increments within the stylet structure (highly reduced internal shells). To validate the periodicity of the increments, stylets were analysed from known-age laboratory-raised Octopus pallidus. The animals, which ranged from 3 to 8 months old, were exposed either to a simulated natural or to constant temperature regime. Transverse stylet sections were embedded in thermo-plastic cement and ground until a thin section was achieved. A pre-hatch region and first post-hatch increment was identified in the stylet microstructure. The number of increments, across all ages and temperature treatments, was in remarkably close agreement to age (number of days), clearly demonstrating that stylet increments are deposited daily throughout the lifecycle of O. pallidus. Morphometric analyses of the stylet indicated that increments were laid down regularly during stylet growth and that stylets grew in concert with body size, further supporting daily periodicity. This study successfully validates daily increments in stylets and thus demonstrate a method to age octopus, therefore, potentially having critical implications for future octopus research and the effective management of stocks worldwide.     

Molecular detection of Leishmania infection in sand flies in border line of Iran–Turkmenistan: Restricted and permissive vectors

A molecular study was carried out to incriminate sand fly vectors of cutaneous leishmaniasis (CL) in rural areas of Sarakhs district, Khorassane-Razavi Province, northeastern Iran, in 2011. Sand flies of Sergentomyia with three species and Phlebotomus with six species respectively comprised 73.3% and 26.7% of the specimens. Phlebotomus papatasi was the most common Phlebotomine species in outdoor and indoor resting places. Leishmania infection was found at least in 17 (22%) specimens including Ph. papatasi (n = 9 pool samples), Phlebotomus caucasicus (n = 6), Phlebotomus alexandri (n = 1), and Sergentomyia sintoni (n = 1). The parasites were found comprised Leishmania major (n = 5), Leishmania turanica (n = 10), and Leishmania gerbilli (n = 4). Infection of Ph. papatasi with both L. major and L. turanica supporting the new suggestion indicating that it is not restricted only with L. major. Circulation of L. major by Ph. alexandri, and both L. gerbilli and L. turanica by Ph. caucasicus, in addition to previous data indicating the ability of Ph. alexandri to circulate Leishmania infantum and Leishmania donovani, and Ph. caucasicus to circulate L. major, suggests that these two species can be permissive vectors. The results suggest that Ph. papatasi and Ph. alexandri are the primary and secondary vectors of CL where circulating L. major between human and reservoirs, whereas Ph. caucasicus is circulating L. turanica and L. gerbilli between the rodents in the region.     

Effects of two acanthocephalan species on the reproduction of Hyalella patagonica (Amphipoda, Hyalellidae) in an Andean Patagonian Lake (Argentina)

The aim of the present study was to evaluate alterations in the reproduction induced by acanthellae and cystacanths of the acanthocephalans Acanthocephalus tumescens and Corynosoma sp. in the amphipod Hyalella patagonica from Lake Mascardi. Specimens of H. patagonica were separated in two categories: paired amphipods (joined specimens during precopulatory mate guarding period until fertilization) and unpaired amphipods (alone specimens). Different analyses were performed: first with paired (n = 406) and unpaired (n = 375) amphipods, and second only with female amphipods (n = 1949), that were classified into three categories (without internal oocytes and eggs, only with internal oocytes, and with eggs). Also, carotenoid extraction was performed of amphipods uninfected (n = 75) and infected (n = 105) by cystacanths of Corynosoma sp. Unpaired amphipods had significantly higher prevalence of cystacanths of both acanthocephalan species than paired ones; but such differences were not found in prevalence of acanthellae. Female amphipods without internal oocytes and eggs showed significantly higher prevalence of cystacanths of both acanthocephalan species than the two other female categories; while females with eggs had significantly higher prevalence of A. tumescens acanthellae. Amphipods infected by Corynosoma sp. showed lower carotenoid concentration than uninfected ones. In Lake Mascardi, there is indirect evidence of both reduced mating success and female fecundity of H. patagonica provoked by both cystacanths species (A. tumescens and Corynosoma sp.). However, infections by acanthellae seem to have no effects.     

Early life-history processes in benthic octopus: Relationships between temperature, feeding, food conversion, and growth in juvenile Octopus pallidus

Initial growth in cephalopods is exponential, making early life-history critical in determining growth trajectories. Few captive studies have however examined the early life-history of cephalopods in fluctuating temperatures as would be encountered in the wild. This study investigates the relationship between early growth and the significant factors affecting growth, namely food intake, food conversion and fluctuating environmental temperatures. Pale octopus (Octopus pallidus) hatchlings were reared in captivity under either a warming or cooling temperature regime. Individual variations and periodicity in feeding rates (F_r), food conversion rates (C_r), growth rates (G_r), and the relationship between these variables and temperature were examined weekly. Food conversion rates were variable between individuals but also within individual octopus, which exhibited large fluctuations in C_r over time, exceeding 100% d^− 1 in one instance. Although individual F_r, C_r and G_r displayed fluctuations over time, there was no evidence of periodicity for any of the variables. Changes in temperature were not significantly correlated to changes in F_r, C_r or G_r. Feeding rate did not appear to influence growth rate or food conversion rate. Food conversion rate was negatively correlated to feeding rate in the same week, and positively correlated to growth rate. Short periods of low or no food consumption were common and the high values obtained for food conversion rate for some individuals suggest that octopus can grow substantially with little or no food intake. Individual variability observed in octopus growth may be dependent on the growth mechanism involved, specifically a fine balance between the continuous hyperplasic and hypertrophic growth found in cephalopods.     

Chemical implantation of Group 4 cations on silica via cyclopentadienyl- and N,N-dialkylcarbamato derivatives

Chemical implantation of Group 4 cations [Ti(III), Ti(IV), Zr(IV), Hf(IV)] has been carried out under mild conditions by the reaction of polycyclopentadienyl- (MCp_n; M = Ti, n = 3, 4; M = Zr, Hf, n = 4), mixed cyclopentadienyl/N,N-dialkylcarbamato (ML_x(O₂CNEt₂)_y; M = Ti, L = Cp, C₅Me₅ (Cp*), x = 2, y = 1; M = Hf, L = Cp, x = 1, y = 3), and N,N-dialkylcarbamato (M(O₂CNR₂)_n, M = Ti, n = 3, R = ⁱPr; M = Ti, Hf, n = 4, R = Et; M = Zr, n = 4, R = ⁱPr) derivatives, with the silanol groups of amorphous silica. Cyclopentadiene/pentamethylcyclopentadiene and/or carbon dioxide and the secondary amine are released in the process. The amount of implanted cations depends on the metal and on the ligands, the pentamethylcyclopentadienyl complex being less reactive than the unsubstituted congener. The starting complexes and the final products have been characterized by EPR or by ¹³C CP-MAS NMR spectroscopy.     

Therapeutic outcomes of combining cryotherapy,chemotherapy and DC-CIK immunotherapy in the treatment of metastatic non-small cell lung cancer

Currently there are no effective therapies for the treatment of metastatic non-small cell lung cancer (NSCLC). Here, we conducted a retrospective study of 161 patients to evaluate the therapeutic effects of combining cryosurgery, chemotherapy and dendritic cell-activated cytokine-induced killer cells (DC-CIK) immunotherapy. The overall survival (OS) after diagnosis of metastatic NSCLC to patient death was assessed during a 5-years follow-up period. OS of patients who received comprehensive cryotherapy was (median OS, 20 months; n = 86) significantly longer than that of patients who did not received cryotherapy (median OS, 10 months; n = 75; P < 0.0001). Five treatment combinations were selected: chemotherapy (n = 44); chemo-immunotherapy (n = 31); cryo-chemotherapy (n = 32); cryo-immunotherapy (n = 21); and cryo-chemo-immunotherapy (n = 33). A combination of cryotherapy with either chemotherapy or immunotherapy lead to significantly longer OS (18 months and 17 months, respectively) compared to chemotherapy and chemo-immunotherapy (8.5 months and 12 months, respectively; P < 0.001); however, the median OS of patients who underwent cryo-chemo-immunotherapy was significantly longer (27 months) compared to the other treatment programs (P < 0.001). In conclusion, a combination of cryotherapy, chemotherapy and DC-CIK immunotherapy proved the best treatment option for metastatic NSCLC in this group of patients.     

Characteristics of the spermathecal contents of old and young honeybee queens

Sperm are often stored, for a long time after mating, in females of various animal species. In case of the queen honeybee (Apis mellifera), sperm remain fertile for several years in the spermatheca. Little information is available regarding the effect of long-term storage of sperm on its fertility. To evaluate this, enzymes and/or sperm have been analysed from the spermatheca of 75 queens of various ages (0 year Y0, n = 14; one year Y1, n = 14; two years Y2, n = 7; virgin queen VQ, n = 40) and semen samples have been taken from 46 drones. The sperm from the spermatheca of older queens move more slowly (F = 11.45, P < 0.0001) and show different movement patterns (Chi² = 90.0, P < 0.0001) from those of the other groups. The spermatheca content of differently aged mated queens differ significantly with respect to the activities of lactate dehydrogenase (F = 3.37, P < 0.05), citrate synthase (F = 6.24, P < 0.005) and arginine kinase (F = 9.44, P < 0.0006). Glyceraldehyde 3-phosphate dehydrogenase (F = 0.10, P = 0.91) does not differ significantly. The results suggest considerable changes in the energy metabolic profile of the spermatheca tissue, of the sperm or of both during sperm storage.     

Glycoprotein 60 diversity in C. hominis and C. parvum causing human cryptosporidiosis in NSW, Australia

Management and control of cryptosporidiosis in human requires knowledge of Cryptosporidium species contributing to human disease. Markers that are able to provide information below the species level have become important tools for source tracking. Using the hypervariable surface antigen, glycoprotein 60 (GP60), C. hominis (n = 37) and C. parvum (n = 32) isolates from cryptosporidiosis cases in New South Wales, Australia, were characterised. Extensive variation was observed within this locus and the isolates could be divided into 8 families and 24 different subtypes. The subtypes identified have global distributions and indicate that anthroponotic and zoonotic transmission routes contribute to sporadic human cryptosporidiosis in NSW.     

A multicenter pilot external quality assessment programme to assess the quality of molecular detection of Chlamydophila pneumoniae and Mycoplasma pneumoniae

An external quality assessment (EQA) panel consisting of a total of 13 samples in broncho alveolar lavage (BAL) or transport medium was prepared to assess the proficiency of laboratories in the correct detection of Chlamydophila pneumoniae and Mycoplasma pneumoniae by nucleic acid amplification techniques (NAATs) (6 samples containing various concentrations (4.9-490 inclusion forming units (IFU)/ml) of C. pneumoniae, 5 samples containing various concentrations (20-5000 color-changing units (CCU)/ml) of M. pneumoniae and 2 samples negative for both).Seventy-nine laboratories from 18 countries participated in this EQA study. Sixty-four datasets were returned for C. pneumoniae (n = 5 conventional commercial, n = 10 conventional in-house, n = 4 real-time commercial, n = 43 real-time in-house, and n = 2 SDA). Sixty-seven datasets were obtained for M. pneumoniae (n = 5 conventional commercial, n = 10 conventional in-house, n = 4 real-time commercial, n = 46 real-time in-house, and n = 2 strand displacement amplification (SDA)). For the total panels, correct results per sample varied between 95.3% and 100% for C. pneumoniae and between 53.7% and 95.5% for M. pneumoniae. In general, commercial conventional NAATs showed possible sensitivity issues when compared to conventional in-house NAATs for both organisms. On the other hand, real-time commercial NAATs scored better than real-time in-house assays in terms of sensitivity for both organisms. For C. pneumoniae and M. pneumoniae, 0.8% and 2.2% true false-positive results and 1.9% and 2.0% false positives were reported in the samples spiked with the other organism.Analysis of the data for C. pneumoniae showed that the concentrations used were easily detectable by the vast majority of participants. The percentage of correct qualitative results for M. pneumoniae demonstrated that the concentrations included in this panel proved challenging for a number of participants.     

Semicircular canal system in early primates

Mammals with more rapid and agile locomotion have larger semicircular canals relative to body mass than species that move more slowly. Measurements of semicircular canals in extant mammals with known locomotor behaviours can provide a basis for testing hypotheses about locomotion in fossil primates that is independent of postcranial remains, and a means of reconstructing locomotor behaviour in species known only from cranial material. Semicircular canal radii were measured using ultra high resolution X-ray CT data for 9 stem primates (“plesiadapiforms”; n = 11), 7 adapoids (n = 12), 4 omomyoids (n = 5), and the possible omomyoid Rooneyia viejaensis (n = 1). These were compared with a modern sample (210 species including 91 primates) with known locomotor behaviours. The predicted locomotor agilities for extinct primates generally follow expectations based on known postcrania for those taxa. “Plesiadapiforms” and adapids have relatively small semicircular canals, suggesting they practiced less agile locomotion than other fossil primates in the sample, which is consistent with reconstructions of them as less specialized for leaping. The derived notharctid adapoids (excluding Cantius) and all omomyoids sampled have relatively larger semicircular canals, suggesting that they were more agile, with Microchoerus in particular being reconstructed as having had very jerky locomotion with relatively high magnitude accelerations of the head. Rooneyia viejaensis is reconstructed as having been similarly agile to omomyids and derived notharctid adapoids, which suggests that when postcranial material is found for this species it will exhibit features for some leaping behaviour, or for a locomotor mode requiring a similar degree of agility.     

Association of the Ser326Cys polymorphism in the OGG1 gene with type 2 DM

The association of the Ser326Cys polymorphism of the 8-oxoguanine glycosylase 1 (OGG1) gene with type 2 diabetes was examined using a Japanese population (n (M/W): 4585 (2085/2500); age: 62.6 ± 10.9 years). HbA1c levels and frequency of diabetic subjects were significantly higher in subjects with genotypes with Cys allele than in those without (p = 0.032 and 0.037, respectively). Multiple logistic regression analysis showed that genotypes with Cys allele were significantly associated with diabetes (OR: 1.32, p = 0.0289). In subjects whose glucose tolerance was classified by FPG and 2-h PG (n = 1.634), the association was more substantial (genotypes with Cys allele vs. without, OR: 1.70, p = 0.0059; genotypes Cys/Cys vs. Ser/Ser, OR: 2.19, p = 0.0008). In subjects with genotype Ser/Ser, the insulin secretion index, HOMA-β, increased in the subjects with glucose intolerance and decreased in the subjects with diabetes, while, in subjects with genotypes Ser/Cys + Cys/Cys, HOMA-β decreased as the glucose tolerance progressed (p for trend = 0.010).     

Growth, size and age at maturity of the agile frog (Rana dalmatina) in an Iberian Peninsula population

The mean age of a population of agile frogs (Rana dalmatina) from the Iberian Peninsula was estimated using mark and recapture and skeletochronology. Life-history parameters, including growth rate, body length, age and size at maturity, sexual dimorphism and longevity, were studied. The regression between age and snout-vent length (SVL) was highly significant in both sexes. Males reached sexual maturity at two years of age, although sometimes they can reach it at only one year of age. The average SVL at maturity was 51.75 mm (standard error (SE) = 0.71; n = 45). Females reached sexual maturity at two years of age with an average SVL of 62.14 mm (SE = 2.20; n = 14). A subset of the female population reached sexual maturity at three years of age. Growth was rapid until sexual maturity was reached. There was an overlap of SVL between different age classes. Growth was continuous, fulfilling the conditions of Von Bertalanffy's model. The growth coefficient (K) was 0.840 in males and 0.625 in females. The maximum SVL was greater in females (73.00 mm) than in males (59.50 mm). Sexual dimorphism was significantly biased towards females in all age classes. The maximum longevity observed was 6 years in females and 8 years in males. Management strategies for agile frogs should take into account factors such as these life-history characteristics.     

Investigating social discrimination of group members by laying hens

Social relationships in domestic fowl are commonly assumed to rely on social recognition and its pre-requisite, discrimination of group-mates. If this is true, then the unnatural physical and social environments in which commercial laying hens are typically housed, when compared with those in which their progenitor species evolved, may compromise social function with consequent implications for welfare. Our aims were to determine whether adult hens can discriminate between unique pairs of familiar conspecifics, and to establish the most appropriate method for assessing this social discrimination. We investigated group-mate discrimination using two learning tasks in which there was bi-directional exchange of visual, auditory and olfactory information. Learning occurred in a Y-maze task (p < 0.003; n = 7/8) but not in an operant key-pecking task (p = 0.001; n = 1/10). A further experiment with the operant-trained hens examined whether failure was specific to the group-mate social discrimination or to the response task. Learning also failed to occur in this familiar/unfamiliar social discrimination task (p = 0.001; n = 1/10). Our findings demonstrate unequivocally that adult laying hens kept in small groups, under environmental conditions more consistent with those in which sensory capacities evolved, can discriminate group members: however, appropriate methods to demonstrate discrimination are crucial.     

Age-related dynamics of follicles and hormones during an induced ovulatory follicular wave in mares

An ovulatory follicular wave was induced by ablation of follicles ≥6 mm and treatment with prostaglandin F2α (PGF) on Day 10 (ovulation = Day 0). Follicle and hormone dynamics of the induced waves were compared among three age groups: young (5-6 y, n = 14 waves), intermediate (10-14 y, n = 16), and old (≥18 y, n = 15). During the common-growth phase of the induced wave (Days 12-17), diameter of the future ovulatory follicle was not different among ages, but the young group had more (P < 0.05) follicles that reached ≥10 mm. The number was correlated (r = +0.7; P < 0.0001) within mares between consecutive interovulatory intervals, indicating repeatability. Concentrations of LH increased in all age groups during Days 12-17, but were greatest (P < 0.002) in the young group and continued to be greater (P < 0.0001) throughout the ovulatory LH surge. During several days before Day −1, there were no age-related effects on systemic estradiol concentrations, diameter of the preovulatory follicle, or B-mode echo texture or color-Doppler signals of blood flow in the follicle wall. Interpretations were: (1) greater number of follicles in the young group reflected a greater follicle reserve, (2) greater LH concentrations throughout the ovulatory surge in the young group reflected a more positive response to an extraovarian/environmental influence after removal of the negative effect of progesterone, and (3) lower LH concentrations in the older groups were adequate for the preovulatory changes in the follicle.