Stage-related Differences Research Articles

Age-dependent effects of metformin on human oligodendrocyte lineage cell ensheathment capacity.

Metformin restores the myelination potential of aged rat A2B5+ oligodendrocyte progenitor cells and may enhance recovery in children with post-radiation brain injury. Human late progenitor cells (O4+A2B5+) have a superior capacity to ensheath nanofibres compared to mature oligodendrocytes, with cells from paediatric sources exceeding adults. In this study, we assessed the effects of metformin on ensheathment capacity of human adult and paediatric progenitors and mature oligodendrocytes and related differences to transcriptional changes. A2B5+ progenitors and mature cells, derived from surgical tissues by immune-magnetic separation, were assessed for ensheathment capacity in nanofibre plates over 2 weeks. Metformin (10 µM every other day) was added to selected cultures. RNA was extracted from treated and control cultures after 2 days. For all ages, ensheathment by progenitors exceeded mature oligodendrocytes. Metformin enhanced ensheathment by adult donor cells but reduced ensheathment by paediatric cells. Metformin marginally increased cell death in paediatric progenitors. Metformin-induced changes in gene expression are distinct for each cell type. Adult progenitors showed up-regulation of pathways involved in the process of outgrowth and promoting lipid biosynthesis. Paediatric progenitors showed a relatively greater proportion of down- versus up-regulated pathways, these involved cell morphology, development and synaptic transmission. Metformin-induced AMP-activated protein kinase activation in all cell types; AMP-activated protein kinase inhibitor BML-275 reduced functional metformin effects only with adult cells. Our results indicate age and differentiation stage-related differences in human oligodendroglia lineage cells in response to metformin. Clinical trials for demyelinating conditions will indicate how these differences translate in vivo.

Microanatomy and ultrastructure of the nervous system of adult Renicola parvicaudatus (Digenea: Renicolidae).

The digenean complex life cycle includes various morphological forms with different locomotory and behavioral activities, and the functional specialization of their nervous system is of importance for the transmission of these parasites. Adult digeneans acquire many adaptive features associated with the final settlement in a vertebrate host. Our study describes the general morphology and ultrastructure of the nervous system of the adult renicolid digenean Renicola parvicaudatus parasitizing the renal tubules of herring gulls. Using immunocytochemical and electron microscopic methods, we identified the distinctive characteristics of ganglia and synapses in the studied species. A comparative analysis of the organization of the nervous system of adult individuals and their continuously-swimming stylet cercariae revealed a number of stage-related differences in the composition of ganglia, the distribution of serotonin- and FMRFamide-immunoreactive neurons, the cytomorphology of neuron somata and free sensory endings. Thus, in adults, the presence of FMRFamide-positive neuron somata, accessory muscle bundles in the ganglionic cortex, and eight types of neuronal vesicles was detected, but no glia-like elements were identified. Their neurons are characterized by a larger volume of cytoplasm and also show greater ultrastructural diversity. Although the sensory papillae of adults do not vary in their external morphology as much as those of larvae, their sensory bulbs are more diverse in cytomorphology. Following our previous data on the "support" cell processes related to various tissues of the larvae and considered as glia-like structures, we also briefly present the identified features of the parenchyma, attachment organs and excretory system of adult individuals. The excretory system of adult R. parvicaudatus is characterized by the presence of unique terminal cells with several flame tufts, which are not typical either for the larvae of this species or for other digeneans studied so far. We also used molecular phylogenetic analysis to clarify species identification.

NEUROTROPIC PROPERTIES OF RETROVIRUSES IN THE CONTEXT OF ANXIETY-DEPRESSIVE AND COGNITIVE DISORDERS IN HIV-POSITIVE PATIENTS

The aim: a comprehensive assessment and comparison of the prevalence of undiagnosed anxiety-depressive and cognitive symptoms in HIV-positive individuals at different stages of the disease who have been undergoing treatment for an extended period. Materials and methods According to the criteria of the scientific project, 71 HIV-positive individuals undergoing outpatient treatment with a compensated condition were involved. To explore dependencies on clinical stages (ClSt) of HIV infection and search for gender differences, the study was divided into 2 stages, respectively. The research included the collection of epidemiological and clinical-anamnestic data, as well as laboratory studies. Clinical-psychopathological and psychometric methods were used. Inclusion criteria for the study were HIV-positive status, receiving ART for more than 6 months, adulthood, and voluntary consent to participate. The obtained information was statistically processed by mathematical methods of statistics, using ANOVA criteria, Student's t-test, etc. Elements of neurocognitive and anxiety-depressive symptomatology were considered, utilizing GAD-7, HADS, and MMSE scales. Results: In patients of different groups in the first stage of the study, a gradually increasing level of anxiety and cognitive impairments was identified, depending on the stage of HIV infection. In the second stage of the study, gender and stage-related differences in anxiety and cognitive disorders were found in patients of all groups. Conclusions. Individuals in the first clinical stage (I ClSt) exhibited the least anxiety-depressive and cognitive disorders, indicating emotional and cognitive stability at this stage of HIV infection. HIV-infected individuals in the second and third clinical stages (II and III ClSt) demonstrated a progressive tendency toward anxious and depressive disorders, indicating a stage-dependent relationship to the progression of the disease. Patients in the fourth clinical stage (IV ClSt) showed the most pronounced anxious, depressive, and cognitive symptoms, which may be associated with the duration of the illness and antiretroviral therapy (ART). Research results in the female group (Group A1) suggest their lower susceptibility to disorders compared to males (Group A2) in the early stages of HIV infection. In the later stages (III-IV), it was found that women had pronounced anxious and depressive disorders (Group B1), while men exhibited signs of cognitive and depressive disorders (Group B2).

0708 Stage-dependent Differences in Central Sleep Apnea (CSA) Predominate in remedē System Pivotal Trial Participants

Abstract Introduction Differences in neuroventilatory control can impact the type and severity of sleep disordered breathing between non-REM and REM sleep. We examined the distribution of central apneic episodes in polysomnograms from subjects with predominantly central sleep apnea, who received phrenic nerve stimulation. Methods Baseline in-lab polysomnograms from patients enrolled in the remedē System Pivotal Trial were scored by a central core laboratory (n=151). Participants with predominantly CSA were enrolled if the apnea-hypopnea index (AHI)≥20/hr, the central apnea index (CAI) exceeded the obstructive apnea index (OAI), and the OAI did not exceed 20% of the total AHI. This post-hoc analysis compared sleep apnea indices in REM and non-REM sleep in those with ≥5 minutes REM sleep (n=131). Within-patient median non-REM - REM differences were calculated and compared. Results REM sleep time was 40 [Q1=28, Q3=64] minutes, and non-REM sleep time was 301 [Q1=269,Q3=344] minutes. AHI in REM sleep was 22/hr [Q1=9,Q3=44] and was 46/hr (Q1=33,Q3=60) in non-REM sleep, yielding a within-patient difference between non-REM and REM sleep of 22/hr ([Q1=6, Q3=34], p<.001). CAI in REM was only 4/hr (Q1=0, Q3=11), but in non-REM was 25/hr [Q1=16,Q3=43] with all patients having a CAI≥5/hr during non-REM. In REM, 70% had a CAI>0/hr and 46% had a CAI ≥5/hr. The CAI difference between non-REM and REM sleep was 18/hr [Q1=10, Q3=30; p<.001]. The OAI and mixed apnea index (MAI) differed by <1/hr (p=0.235 and <.001, respectively). Of note, the hypopnea index [HI] did not differ between REM and non-REM sleep (12/hr [Q1=2,Q3=22] vs. 11/hr [Q1=4, Q3=20], respectively, p=0.273), yet hypopneas constituted a greater proportion of total AHI during REM compared to non-REM sleep. Conclusion Among subjects with predominantly CSA, the prevalence and severity of CSA was greater in non-REM than REM sleep, yet low-level CSA persisted in REM sleep. Stage-related differences in CAI but not OAI, MAI or HI can be attributed to alterations in ventilatory rather than upper airway control in this CSA cohort. These differences in the type and severity of sleep disordered breathing episodes comprise a key diagnostic signature, for which specific CSA therapeutic strategies are indicated. Support (If Any) ZOLL Respicardia, Inc. and NIH R01 HL144859

Impact of malathion toxicity on the oxidative stress parameters of the black soldier fly Hermetia illucens (Linnaeus, 1758) (Diptera: Stratiomyidae)

The black soldier fly larvae (BSFL) may serve as a promising tool in the animals feed production industry. The input organic wastes may be contaminated by insecticides that affect both the insect’s mass rearing, and the animals feed process. Therefore, in the current study the assessment of oxidative stress parameters of the black soldier fly (BSF) were investigated to quantify the deleterious effect of malathion-contaminated kitchen waste (1:1 vegetable: fruit waste) container on the insect. The different developmental stages of insect (adult and larva) were exposed to different concentrations (0, 0.005, 0.01, 0.015, and 0.02 mg/mL) of malathion. The results showed that the mean value of the reactive oxygen species (ROS), which included hydrogen peroxide (H2O2) and superoxide anion radicals (O2•-) concentrations were lower in larval stage than in adults, in all treated groups (0, 0.005, 0.01, 0.015, and 0.02 mg/mL malathion concentration). Also, the protein carbonyls amount and lipid peroxides levels were decreased in the 0.02 mg/mL Malathion compared to the control values. However, the cluster analysis revealed slight dissimilar patterns for control insects and the highest malathion concentration (0.02 mg/ml). These stage-related differences could occur from the different growth dynamic functions of larvae and adults. The larvae were distinguished by robust growth, and significant oxygen consumption. The results verified that oxidative stress parameters, especially protein carbonyls and α, α-diphenyl-β-picrylhydrazyl (DPPH) were promising, cheap, quick and cost-effective applications for determining the macromolecules damage, and antioxidant ability of H. illucens enclosed with malathion exposure. These findings described that malathion application induces macromolecules damage mediated through oxidative stress injury.

Sex- and Developmental Stage-Related Differences in the Hepatic Transcriptome of Japanese Quail (Coturnix japonica) Exposed to 17β-Trenbolone.

Endocrine-disrupting chemicals can cause transcriptomic changes that may disrupt biological processes associated with reproductive function including metabolism, transport, and cell growth. We investigated effects from in ovo and dietary exposure to 17β-trenbolone (at 0, 1, and 10 ppm) on the Japanese quail (Coturnix japonica) hepatic transcriptome. Our objectives were to identify differentially expressed hepatic genes, assess perturbations of biological pathways, and examine sex- and developmental stage-related differences. The number of significantly differentially expressed genes was higher in embryos than in adults. Male embryos exhibited greater differential gene expression than female embryos, whereas in adults, males and females exhibited similar numbers of differentially expressed genes (>2-fold). Vitellogenin and apovitellenin-1 were up-regulated in male adults exposed to 10 ppm 17β-trenbolone, and these birds also exhibited indications of immunomodulation. Functional grouping of differentially expressed genes identified processes including metabolism and transport of biomolecules, enzyme activity, and extracellular matrix interactions. Pathway enrichment analyses identified as perturbed peroxisome proliferator-activated receptor pathway, cardiac muscle contraction, gluconeogenesis, growth factor signaling, focal adhesion, and bile acid biosynthesis. One of the primary uses of 17β-trenbolone is that of a growth promoter, and these results identify effects on mechanistic pathways related to steroidogenesis, cell proliferation, differentiation, growth, and metabolism of lipids and proteins. Environ Toxicol Chem 2021;40:2559-2570. © 2021 SETAC. This article has been contributed to by US Government employees and their work is in the public domain in the USA.

Prognostic and Predictive Values of Mismatch Repair Deficiency in Non-Metastatic Colorectal Cancer.

Simple SummaryA subset of colorectal cancers (CRCs) displays deficient DNA mismatch repair (dMMR) that leads to microsatellite instability (MSI). These tumors have distinct clinicopathological features and have been associated with a more favorable prognosis. Knowledge of mismatch repair (MMR) status has important implications for disease diagnosis, surgical intervention, and adjuvant treatment decisions.Colorectal cancer (CRC) is the third most commonly diagnosed cancer worldwide. Universal MMR/MSI testing is standard of care for all patients with newly diagnosed CRC based on multi-society guidelines in the United States. Such testing is intended to identify patients with Lynch Syndrome due to a germline mutation in an MMR gene, but also detects those with sporadic dMMR/MSI-high CRCs. The prognostic utility of MMR/MSI status in non-metastatic colorectal cancer has been studied extensively, yet more limited data are available for its predictive utility. Results have not been entirely consistent due to potential stage-related differences and limited numbers of dMMR/MSI-H patients included in the studies. In this review, we summarize the current evidence for the prognostic and predictive value of dMMR/MSI-H in non-metastatic CRC, and discuss the use of this biomarker for patient management and treatment decisions in clinical practice.

The influence of stage of illness on functional outcomes after psychological treatment in bipolar disorder: A systematic review.

The aim of this study was to advance understanding of stage of illness in bipolar disorder (BD), by interrogating the literature for evidence of an influence of stage of illness on functional (ie non-symptom) outcomes following psychosocial intervention. A systematic literature search following PRISMA guidelines was conducted to identify empirical studies of psychosocial interventions for established BD. To investigate stage as a predictor of three functional outcomes (general/social functioning, cognitive functioning and quality of life [QoL]), study samples were dichotomised into earlier and later stage using proxy measures identified in existing staging models. Findings were integrated using data-based convergent synthesis. A total of 88 analyses from 62 studies were identified. Synthesis across studies suggested that psychosocial intervention was more likely to be effective for general functioning outcomes earlier in the course of established BD. No stage-related differences were found for cognitive or QoL outcomes. Exploratory investigations found some evidence of an interaction between specific intervention type and stage of illness in predicting outcomes. A novel systematic review provided preliminary evidence that benefits general/social functioning may be more pronounced in earlier versus later stages of established BD. The review also generated hypotheses about a potential three-way interaction, whereby specific psychosocial interventions may be best placed to target functional outcomes in earlier versus later stage BD. The strength of conclusions is limited by the overall low-quality and significant heterogeneity of studies. Further research is urgently required to understand the impact of illness stage on the effectiveness of psychosocial interventions.

Sex and sex-related differences in gamete development progression impinge on biomarker responsiveness in sentinel mussels

In marine pollution monitoring, the biomarkers recorded in sentinel organisms are influenced by natural confounding factors that may jeopardise their interpretation. Among these confounding factors, little is known about the influence of sex along the annual reproductive cycle. The present investigation aims at contributing to understand how sex and sex-related differences in gamete development progression impinge on biomarker baseline values and on biomarker responsiveness to pollution in sentinel mussels. Mussels (Mytilus galloprovincialis) were collected from a relatively clean locality and from a chronically polluted site in the Basque Coast (Bay of Biscay) in January, April, August and November. Sex and gametogenesis stages were determined for each mussel. Tissue concentration of metals and PAHs was analysed. A battery of biomarkers was investigated: cytochrome c oxidase, pyruvate kinase and phosphoenolpyruvate carboxykinase enzyme activities; levels of protein carbonyls, malondialdehyde and 4-hydroxy-2-nonenal; lysosomal enlargement and membrane stability; intracellular neutral lipid accumulation; cell type composition and thinning of the digestive gland epithelium; and survival-in-air. Sex- and reproductive stage-related differences were found in bioaccumulation and in the values and responsiveness of most of the biomarkers. However, the patterns of sex-related differences were not consistent across all biomarkers. The differences in the biomarker responses between females and males also depended on the season, reflecting the progression of the gametogenesis cycle. Thus, selecting mussels of one specific sex does not seem to be a crucial requisite to carry out biomarker-based monitoring; yet, it is highly recommended to identify sex condition and gamete developmental stage of each mussel to test for the potentially confounding effects of sex, reproductive status and sex-related variability along the reproductive cycle.

Origin and foraging ecology of male loggerhead sea turtles from southern Brazil revealed by genetic and stable isotope analysis

The southwestern Atlantic Ocean (SWA) represents an important foraging ground for loggerhead sea turtles (Caretta caretta). Most studies at the region have focused on adult females and juveniles, and little is known about males. Here, we present the first insights about origin and foraging ecology of male loggerheads from the SWA, by integrating genetic and stable isotope analysis (SIA). Skin samples were obtained from 26 males stranded along the southern coast of Brazil (from 31°21′S–51°05′W to 33°44′S–53°22′W), from February 2014 to March 2017. Samples of potential food sources (benthic and pelagic organisms) were also collected for SIA. A fragment of the mitochondrial DNA control region was sequenced and a Bayesian Mixed Stock Analysis was performed to estimate natal origins of male loggerheads. Bayesian Stable Isotope Mixing Models were fitted to assess the relative contribution of different food sources assimilated by males. Most males exhibit endemic haplotypes from Brazilian rookeries, followed by a low frequency of a haplotype from the North Atlantic and the Mediterranean Sea, as well as olive ridley (Lepidochelys olivaea) haplotype, showing hybridization. SIA showed life stage-related differences in feeding and habitat use by male loggerheads, with benthic invertebrates dominating the diet of adults, while pelagic prey items dominated the diet of juveniles. Our findings demonstrate the importance of southern Brazil neritic and oceanic habitats for male loggerheads and highlight the value of this area for the maintenance of SWA reproductive management units, which are the main contributors to these feeding aggregations.

Three-dimensional longitudinal evaluation of facial mimicry in orthognathic class III surgery

The effect of bimaxillary orthognathic surgery on facial mimicry was assessed longitudinally in 15 patients with dentoskeletal class III facial dysmorphism (seven men, eight women, mean age 28 years). The patients were analysed pre-surgery and at 6, 12, and 24 months post-surgery while performing verbal (five vowels) and non-verbal (open and closed mouth smile, lip purse) soft tissue facial movements. The three-dimensional motions of right and left nasogenian, crista philtri, cheilion, and lower lip landmarks were detected by an optoelectronic instrument, and a total mobility index was obtained. Differences between the sides were quantified by the symmetry index. Patient values were compared to those collected previously from healthy volunteers by computing z-scores. On average, no significant differences were found in the mobility of the buccal soft tissues at 24 months after surgery (ANOVA P-value, range 0.075–0.808), with positive median z-scores (pooled mean value close to 0.6). Symmetry indices ranged around the control reference values, showing no stage-related differences (Friedman test P-value, range 0.252–0.937), and exceeding 90% for all movements at 24 months after surgery. Bimaxillary osteotomy does not compromise facial mimicry in either verbal or non-verbal facial movements.

Joint effects of chlorpyrifos and mancozeb on the terrestrial isopod Porcellionides pruinosus: A multiple biomarker approach.

The exposure to pesticides by nontarget soil biota has long been regarded as a serious downside of modern agricultural regimes and the subject of heated debate. Of utmost relevance is the exposure to pesticide mixtures because their effects have been shown to not necessarily reflect the individual toxicity of their components, and even the simple addition of effects may lead to consequences not clearly anticipated. In the present study, a multiple biomarker approach was employed to identify the mechanistic and time effects underlying several single and mixture treatments of chlorpyrifos (CPF) and mancozeb (MCZ) in juveniles and adults of the terrestrial isopod Porcellionides pruinosus. The effects of the individual pesticides and the mixtures at recommended doses were mostly transitory under these controlled conditions and one-pulse exposure. Whereas imbalances were identified on detoxification and oxidative stress-related enzymes, the isopods generally showed the ability to recover through the end of the experiment. However, juveniles displayed greater vulnerability than adults. Most of the differences between life stages occurred in energy-related parameters where distinct performances and stress-handling behaviors were observed, suggesting higher metabolic costs to juveniles. Our results stress that understanding the time dependence of the underlying mechanisms governing the joint effects of the pesticides can help in assessing and anticipating the effects of the pesticide mixtures. Moreover, we emphasize the importance of taking life stage-related differences into consideration when evaluating the environmental risks of pesticides and pesticide mixtures. Environ Toxicol Chem 2018;37:1446-1457. © 2018 SETAC.

Follicular expression of pro-inflammatory cytokines tumour necrosis factor-α (TNFα), interleukin 6 (IL6) and their receptors in cattle: TNFα, IL6 and macrophages suppress thecal androgen production in vitro.

Pro-inflammatory cytokines secreted by macrophages and other cell types are implicated as intraovarian factors affecting different aspects of ovarian function including follicle and corpus luteum 'turnover', steroidogenesis and angiogenesis. Here, we compared granulosal (GC) and thecal (TC) expression of TNF, IL6 and their receptors (TNFRSF1A, TNFRSF1B and IL6R) during bovine antral follicle development; all five mRNA transcripts were detected in both GC and TC and statistically significant cell-type and follicle stage-related differences were evident. Since few studies have examined cytokine actions on TC steroidogenesis, we cultured TC under conditions that retain a non-luteinized 'follicular' phenotype and treated them with TNFα and IL6 under basal and LH-stimulated conditions. Both TNFα and IL6 suppressed androgen secretion concomitantly with CYP17A1 and LHCGR mRNA expression. In addition, TNFα reduced INSL3, HSD3B1 and NOS3 expression but increased NOS2 expression. IL6 also reduced LHCGR and STAR expression but did not affect HSD3B1, INSL3, NOS2 or NOS3 expression. As macrophages are a prominent source of these cytokines in vivo, we next co-cultured TC with macrophages and observed an abolition of LH-induced androgen production accompanied by a reduction in CYP17A1, INSL3, LHCGR, STAR, CYP11A1 and HSD3B1 expression. Exposure of TC to bacterial lipopolysaccharide also blocked LH-induced androgen secretion, an effect reduced by a toll-like receptor blocker (TAK242). Collectively, the results support an inhibitory action of macrophages on thecal androgen production, likely mediated by their secretion of pro-inflammatory cytokines that downregulate the expression of LHCGR, CYP17A1 and INSL3. Bovine theca interna cells can also detect and respond directly to lipopolysaccharide.

Life stage-related differences in fatty acid composition of an obligate ectoparasite, the deer ked (Lipoptena cervi)—Influence of blood meals and gender

Metamorphosis and diet often influence fatty acid (FA) signatures (FAS) of insects. We investigated FAS in a hematophagous ectoparasite, the deer ked (Lipoptena cervi). Deer keds shed their wings upon attachment on the host and, thus, the FAS of an individual blood-fed imago/pupa in the fur of its host can be traced back to the blood FA profile of a single moose (Alces alces). Host blood and different life stages of deer keds were investigated for FA by gas chromatography. The FAS of life stages resembled each other more closely than the diet. Blood meals modified the FAS of both sexes but the FAS of the blood-fed females were closer to those of the prepupae/pupae. The parasitizing males had higher proportions of major saturated FA (SFA) and polyunsaturated FA (PUFA) than the females, which contained more monounsaturated FA (MUFA) with higher ratios of n-3/n-6 PUFA and unsaturated FA (UFA)/SFA. The proportions of 16:1n-7 were <1% in the blood but 18% (males) and 29% (females) in the blood-fed keds. Allocation of lipids to offspring by the females and possible accumulation of PUFA in male reproductive organs may have induced these sex-related differences. MUFA percentages and UFA/SFA ratios increased while SFA and many PUFA decreased from the reproducing females to the pupae. The diapausing pupae displayed lowered n-3/n-6 PUFA ratios and could have mobilized 16:0 and 18:3n-3 for the most fundamental metabolic processes. In conclusion, FAS are modified through the life stages of the deer ked possibly due to their different FA requirements.

Environmental- and growth stage-related differences in the susceptibility of terrestrial isopods to UV radiation

Global environmental changes are nowadays one of the most important issues affecting terrestrial ecosystems. One of its most significant expressions is the increasing ultraviolet radiation (UVR) arising from the human-induced depletion in ozone layer. Therefore, to investigate the effects of UVR on the terrestrial isopod Porcellionides pruinosus a multiple biomarker approach was carried out. Two experiments were performed in order to analyze the importance of the exposure environment and the growth stage on the UV-induced damages. First, adult individuals were exposed to UVR in three exposure environments (soil, soil with leaves, and plaster). Thereafter, three growth stages using soil as the exposure condition were tested. Integrated biomarker responses (IBR) suggested that UV effects were higher in plaster, and mostly identified by changes in acetylcholinesterase and glutathione-S-transferases activities, lipid peroxidation rates, and total energy available. The effects in soil and soil with leaves were not so clear. In the growth stages’ experiment, juveniles and pre-adults were found to be more affected than adults, with the greatest differences between irradiated and non-irradiated isopods occurring in energy-related parameters. Our findings suggest that soil surface-living macrofauna may be prone to deleterious effects caused by UVR, highlighting the importance of taking the media of exposure and growth stage in account.

Functional connectivity in slow-wave sleep: identification of synchronous cortical activity during wakefulness and sleep using time series analysis of electroencephalographic data

Sleep is a behavioral state ideal for studying functional connectivity because it minimizes many sources of between-subject variability that confound waking analyses. This is particularly important for potential connectivity studies in mental illness where cognitive ability, internal milieu and active psychotic symptoms can vary widely across subjects. We, therefore, sought to adapt techniques applied to magnetoencephalography for use in high-density electroencephalography (EEG), the gold-standard in brain-recording methods during sleep. Autoregressive integrative moving average modeling was used to reduce spurious correlations between recording sites (electrodes) in order to identify functional networks. We hypothesized that identified network characteristics would be similar to those found with magnetoencephalography, and would demonstrate sleep stage-related differences in a control population. We analysed 60-s segments of low-artifact data from seven healthy human subjects during wakefulness and sleep. EEG analysis of eyes-closed wakefulness revealed widespread nearest-neighbor positive synchronous interactions, similar to magnetoencephalography, though less consistent across subjects. Rapid eye movement sleep demonstrated positive synchronous interactions akin to wakefulness but weaker. Slow-wave sleep (SWS), instead, showed strong positive interactions in a large left fronto-temporal-parietal cluster markedly more consistent across subjects. Comparison of connectivity from early SWS to SWS from a later sleep cycle indicated sleep-related reduction in connectivity in this region. The consistency of functional connectivity during SWS within and across subjects suggests this may be a promising technique for comparing functional connectivity between mental illness and health.

Life stage-related differences in susceptibility to acrylamide-induced neural and testicular toxicity

In order to assess age-dependence of susceptibility to acrylamide (ACR)-induced neural and testicular toxicity, 3- and 7-week-old male SD rats were given ACR at 0, 50, 100, or 200ppm in the drinking water for 4weeks, and the nervous and male reproductive systems were examined histopathologically. Testicular genotoxicity was evaluated with the comet assay and the micronucleus (MN) test. Glutathione S-transferase (GST) activity and glutathione (GSH) content in the liver and testis were also measured. In both young and adult animals, neurotoxicity was evident from 100ppm and increased in proportion to ACR intake per body weight. In the testis, marked degeneration and exfoliation, mainly of spermatids, were observed from 100ppm limited to young animals. The comet assay revealed ACR to significantly induce DNA damage from 100ppm in both life stages, while MNs were found only in young rats from 100ppm. The level of GST activity in the testis of young rats at the end of experiment was significantly lower than that of adult animals, regardless of the ACR treatment. There were no life stage-related differences in GSH contents in the liver and testis. These results suggest that susceptibility to neurotoxicity might not differ between young and adult rats when exposure levels are adjusted for body weight. Regarding testicular toxicity, young animals around puberty proved more susceptible than adult animals, possibly due to their lower level of testicular GST activity than that in adult animals.

Feeding and reproductive behaviour of pigeon slender louse, Columbicola columbae (Phthiraptera, Insecta, Ischnocera)

Columbicola columbae, the pigeon slender louse mostly feeds upon the barbules of feathers but in addition to this it also feeds upon skin scurf, epidermal scales, sheaths of growing feathers, pellicle of skin etc. C. columbae is exclusively keratin feeder and does not take host blood. Any sex or stage related difference in feeding habit has not been recorded. It neither harbours any triturating agent in the crop nor is involved in cannibalism or predation. C. columbae exhibits sub-feminal mating behaviour (i.e., the male is under the female). Completecopulation lasts about 10 hours. The louse prefers the wing and tail feathers for oviposition. The eggs are generally laid on the ventral surface of the first row of undercoverts of wing feathers. Every event that takes place prior to eclosion of nymph, the time required for detachment of operculum and the freeing of nymph has been noted during hatching.

The Role of Psychological Characteristics in Facilitating the Pathway to Elite Performance Part 2: Examining Environmental and Stage-Related Differences in Skills and Behaviors

MacNamara, Button, &amp; Collins (under review) proposed that if individuals are to fulfill their potential they must possess and systematically develop a specific set of skills (termed Psychological Characteristics of Developing Excellence or PCDEs) that allow them to interact effectively with the developmental opportunities they are afforded. Given the complexity of the developmental pathway, it may well be that different skills are needed at different stages of development and across different performance domains. Twenty-four elite participants from team sports, individual sports, and music were purposefully sampled from different domains and interviewed on their experiences of their own pathways to excellence. Results suggested that although PCDEs were important throughout development, the manner by which they were deployed depended on stage, domain, and the characteristics of the individual performer. These findings support proposals to systematically incorporate PCDEs into TID practices because these may be the key feature in maintaining progress toward excellence.

Mental health problems during puberty: Tanner stage-related differences in specific symptoms. The TRAILS study

The aim of this study was to investigate associations between specific mental health problems and pubertal stage in (pre)adolescents participating in the Dutch prospective cohort study TRAILS (first assessment: N = 2230, age 11.09 ± 0.56, 50.8% girls; second assessment: N = 2149, age 13.56 ± 0.53, 51.0% girls). Mental health was assessed by the Youth Self-Report, pubertal (Tanner) stage by parent-rated drawings of secondary sex characteristics. Overall, higher Tanner stages were related to more reported tiredness, irritability, rule-breaking behaviors, and substance use; and fewer fears and somatic complaints. Girls showed increases in social uncertainty, depressed mood, and worries; boys a decrease in self-criticism. Increasing problems during puberty were mostly related to the process of physical maturation, whereas decreasing problems were rather related to general age-related developments. Pubertal timing was associated with different symptoms than pubertal status or age. Puberty seems to affect girls more negatively than boys.