577 research outputs found
Ultradian, circadian and seasonal rhythms in cortisol secretion and adrenal responsiveness to ACTH and yarding in unrestrained red deer (Cervus elaphus) stags
Seasonal changes in the activity and responsiveness of the adrenal gland in red deer (Cervus elaphus) stags were quantified by measuring 24 h endogenous cortisol secretory profiles and plasma cortisol responses to either administration of exogenous ACTH or a standardised stressor during November (period of velvet growth), February (pre-rut), April (mid-rut) and July (post-rut) (southern hemisphere) using a remote blood sampling device (DracPac). Ultradian rhythms in the concentration of plasma cortisol were observed resulting from the episodic secretion of cortisol from the adrenal cortex at a mean rate of 0.8 pulses/h. Circadian rhythms in plasma cortisol concentrations were also found in 11 out of the 20 complete 24 h profiles (mean amplitude, 3.8+/-1.4 ng/ml). Seasonal rhythms in mean 24 h plasma cortisol concentrations and cortisol pulse parameters were also observed. Mean 24 h plasma cortisol concentrations were higher in November (12.5+/-1.0 ng/ml) than in February (6.3+/-1.0 ng/ml), April (4.0+/-1.0 ng/ml) or July (4.2+/-1. 0 ng/ml). Cortisol pulse height, nadir and amplitude were all significantly higher in November than at other times of the year (P<0.01). Peak cortisol concentrations following infusion of ACTH(1-24) (0.04 IU kg(-1)) were higher (P<0.05) in November (55.8+/-2.7 ng/ml) and lower (P<0.001) in April (33.7+/-1.8 ng/ml) than those in February and July (48.7+/-2.0 ng/ml and 45.4+/-2.0 ng/ml respectively). The area under the cortisol response curve was significantly smaller (P<0.05) in April (266.6+/-15.3 ng/ml/190 min) than at other times of the year (February, 366.1+/-15.3 ng/ml/190 min; July, 340.7+/-15.3 ng/ml/190 min and November, 387.8+/-21.2 ng/ml/190 min). These data demonstrate that the adrenal gland of the red deer stag exhibits ultradian, circadian and seasonal rhythms in activity, and that its responsiveness to ACTH varies with season. November, a period of reproductive quiescence in the southern hemisphere, with new antler growth and rapid weight gain, is associated with higher mean plasma cortisol concentrations and a greater responsiveness to exogenous ACTH. In contrast, the breeding season is associated with lower adrenal activity and responsiveness
Association between family history and mismatch repair in colorectal cancer
BACKGROUND AND AIMS: Germline mutations in mismatch repair (MMR) genes cause a greatly increased
risk of cancer of the gastrointestinal and female reproductive tracts (hereditary non-polyposis colorectal
cancer (HNPCC)). Loss of MMR expression is common in colorectal cancer (CRC) overall. Such loss is
assumed to be acquired predominantly, although a population of CRC cases will include individuals with
unrecognised MMR mutations. This study examines the association between MMR gene expression and
family history of cancer among the CRC population.
METHODS: Individuals with CRC were identified from two well characterised populations: (1) consecutive
hospital patients (n = 644) and (2) a population based cases series (n = 249). CRC was examined for
expression of hMLH1 and hMSH2 using immunohistochemistry, and expression was related to family history using logistic regression.
RESULTS: hMLH1 and hMSH2 expression was assessed in 732 CRCs with 8% showing loss of expression.
No association was seen overall for hMLH1 or hMSH2 expression and family history of CRC. Loss of
hMSH2 was predicted by family history of extracolonic cancer (odds ratio (OR) 5.78 (95% confidence
interval (CI) 0.95â35.18)) and family history suggestive of HNPCC (OR 27.84 (95% CI 4.37â177.56)).
Loss of hMLH1 was not predicted by family history of extracolonic cancer or a family history suggestive of
HNPCC but was for a family history of at least two affected relatives (OR 4.88 (95% CI 1.25â19.03)).
CONCLUSIONS: Individuals with hMSH2 deficient CRC in the general population exhibit a family history and
other characteristics suggestive of HNPCC, and may carry germline MMR mutations. Loss of hMLH1 is only
associated with a strong family history of extracolonic cancer at older ages, suggesting a novel mechanism
of susceptibility
Postweaning maternal care increases male chimpanzee reproductive success
International audienceHumans are unusual among animals for continuing to provision and care for their offspring until adulthood. This "prolonged dependency" is considered key for the evolution of other notable human traits, such as large brains, complex societies, and extended postreproductive lifespans. Prolonged dependency must therefore have evolved under conditions in which reproductive success is gained with parental investment and diminished with early parental loss. We tested this idea using data from wild chimpanzees, which have similarly extended immature years as humans and prolonged mother-offspring associations. Males who lost their mothers after weaning but before maturity began reproducing later and had lower average reproductive success. Thus, persistent motherimmature son associations seem vital for enhancing male reproductive success, although mothers barely provision sons after weaning. We posit that these associations lead to social gains, crucial for successful reproduction in complex social societies, and offer insights into the evolution of prolonged dependency
Achieving cleaner water for UN sustainable development goal 6 with natural processes: Challenges and the future.
UN Sustainable Development Goal 6 aims to achieve clean water for all. Access to clean water is a basic human right but can be costly and challenging. Using natural processes to provide cleaner water for treatment is a cost effective, and often beneficial to other ecosystem services, method. Unfortunately, there are a number of barriers to the implementation of natural processes for cleaner water such as the difficulty of funding these nature-based solutions which is linked to the requirement of accurate valuation. Once funded, partnership with land practitioners is important to ensure that detrimental impacts are not experienced elsewhere and to ensure that these natural processes such as ponds and constructed wetlands are maintained and managed appropriately. The future in the United Kingdom and Europe, in general, is optimistic despite the large funding gap for nature-based solutions overall. Green finance, essentially a loan or investment to support environmentally-friendly activities, has been developed to funnel money towards sustainable investments with an environmental focus, and the percentage of world wealth spent on such investments has increased
Genomic heterogeneity and prevalence of hepandensovirus in Penaeus esculentus from Western Australia, and P. merguiensis from the Gulf of Carpentaria, Australia
Decapod Hepandensovirus 1 (HDV), formerly known as hepatopancreatic parvovirus, has been associated with stunting, lowered production and outright mortalities in prawns in aquaculture. Despite the fact that broodstock are sourced and aquaculture farms are planned in the regions of northern and Western Australia, data on these parvoviruses from this region are limited. The prevalence of HDV in Penaeus esculentus and Penaeus merguiensis is moderate (34â51%) in southern Western Australia, Exmouth Gulf and the Gulf of Carpentaria but statistically higher (P < 0.05) in Shark Bay (82%). We speculate this is due to the topography of Shark Bay combined with the currents of the Indian Ocean gyre (IOG). Despite an on average 8â12% genomic heterogeneity, the nucleotide sequences of HDV in WA most closely align with HDV in regions associated with the IOG; Thailand, India, Tanzania, Madagascar; eastern Asia, Korea and less commonly, with sequences from the eastern coast of Australia. This potentially changes the paradigm of a single strain of HDV being ubiquitous in Australia and there was little risk in moving broodstock from WA to the eastern states, so there was no testing of broodstock for HDV. There is no strong evidence to clarify whether the strain of HDV in WA P. esculentus came from either itsâ nearest genetic relatives, P. monodon or P. semisulcatus or from P. merguiensis from the Solanderian province of Australia. P. esculentus HDV appears to be most related to strains within the IOG. The HDV nucleotide heterogeneity of wild prawns contrasts strongly to studies undertaken with prawns from aquaculture where genetic selection may have occurred
The application of high temporal resolution data in river catchment modelling and management strategies
Modelling changes in river water quality, and by extension developing river management strategies, has historically been reliant on empirical data collected at relatively low temporal resolutions. With access to data collected at higher temporal resolutions, this study investigated how these new dataset types could be employed to assess the precision and accuracy of two phosphorus (P) load apportionment models (LAMs) developed on lower resolution empirical data. Predictions were made of point and diffuse sources of P across ten different sampling scenarios. Sampling resolution ranged from hourly to monthly through the use of 2000 newly created datasets from high frequency P and discharge data collected from a eutrophic river draining a 9.48 km2 catchment. Outputs from the two LAMs were found to differ significantly in the P load apportionment (51.4% versus 4.6% from point sources) with reducing precision and increasing bias as sampling frequency decreased. Residual analysis identified a large deviation from observed data at high flows. This deviation affected the apportionment of P from diffuse sources in particular. The study demonstrated the potential problems in developing empirical models such as LAMs based on temporally relatively poorly-resolved data (the level of resolution that is available for the majority of catchments). When these models are applied ad hoc and outside an expert modelling framework using extant datasets of lower resolution, interpretations of their outputs could potentially reduce the effectiveness of management decisions aimed at improving water quality
Chimpanzee vowel-like sounds and voice quality suggest formant space expansion through the hominoid lineage
The origins of human speech are obscure; it is still unclear what aspects are unique to our species or shared with our evolutionary cousins, in part due to a lack of common framework for comparison. We asked what chimpanzee and human vocal production acoustics have in common. We examined visible supra-laryngeal articulators of four major chimpanzee vocalizations (hoos, grunts, barks, screams) and their associated acoustic structures, using techniques from human phonetic and animal communication analysis. Data were collected from wild adult chimpanzees, TaĂŻ National Park, Ivory Coast. Both discriminant and principal component classification procedures revealed classification of call types. Discriminating acoustic features include voice quality and formant structure, mirroring phonetic features in human speech. Chimpanzee lip and jaw articulation variables also offered similar discrimination of call types. Formant maps distinguished call types with different vowel-like sounds. Comparing our results with published primate data, humans show less F1âF2 correlation and further expansion of the vowel space, particularly for [i] sounds. Unlike recent studies suggesting monkeys achieve human vowel space, we conclude from our results that supra-laryngeal articulatory capacities show moderate evolutionary change, with vowel space expansion continuing through hominoid evolution. Studies on more primate species will be required to substantiate this.This article is part of the theme issue âVoice modulation: from origin and mechanism to social impact (Part II)â
Variable use of polyadic grooming and its effect on access to social partners in wild chimpanzees and bonobos
In mammals, allogrooming is prominent in forming and maintaining social and cooperative relationships. Yet an animal's social time is constrained, which may limit its access to a large number of partners. Dunbar (1993, Behavioral and Brain Sciences, 16 (4), 681â694) proposed that human polyadic conversations, which allow access to several social partners simultaneously, evolved as a form of social grooming to circumvent this time constraint. In nonhuman primates, polyadic grooming (PG), in contrast to dyadic grooming, may similarly be a time-efficient way to maintain weak social relationships with many partners which can be important for group level cooperation. It remains unknown whether PG is used to fulfil specific cooperative needs by accessing numerous weakly bonded partners and increasing the number of partners accessed per unit of time. We compared the use and effect of PG between chimpanzees, Pan troglodytes, which are highly territorial and collaborative (especially males), and bonobos, Pan paniscus, which are less territorial and collaborative and in which females are the main co-operators. We carried out focal grooming observations in one bonobo and two chimpanzee communities in the wild. As predicted, chimpanzees engaged in more PG than bonobos. Surprisingly, males engaged in PG more than females in both species. While chimpanzees accessed more partners per minute of grooming than bonobos via dyadic grooming, PG increased the number of partners accessed per minute only in bonobos. Finally, chimpanzees primarily used PG with individuals who were close in rank and frequent grooming partners, whereas bonobos used PG with individuals who were distant in rank, close party associates and frequent grooming partners. We suggest that bonobo males use PG to enhance conspecific social tolerance and mate choice. The overall higher rate of PG in chimpanzees suggests that between-group competition may promote polyadic affiliation, which possibly reinforces group cohesion and coordination. © 2020 The Author
Bridging the Gap Between the Foreland and Hinterland II: Geochronology and Tectonic Setting of Ordovician Magmatism and Basin Formation on the Laurentian Margin of New England and Newfoundland
Ordovician strata of the Mohawk Valley and Taconic allochthon of New York and the Humber margin of Newfoundland record multiple magmatic and basin-forming episodes associated with the Taconic orogeny. Here we present new U-Pb zircon geochronology and whole rock geochemistry and neodymium isotopes from Early Paleozoic volcanic ashes and siliciclastic units on the northern Appalachian margin of Laurentia. Volcanic ashes in the Table Point Formation of Newfoundland and the Indian River Formation of the Taconic allochthon in New York yield dates between 466.16 ± 0.12 and 464.20 ± 0.13 Ma. Red, bioturbated slate of the Indian River Formation record a shift to more juvenile neodymium isotope values suggesting sedimentary contributions from the Taconic arc-system by 466 Ma. Eight ashes within the Trenton Group in the Mohawk Valley were dated between 452.63 ± 0.06 and 450.68 ± 0.12 Ma. These ashes contain zircon with Late Ordovician magmatic rims and 1.4 to 1.0 Ga xenocrystic cores that were inherited from Grenville basement, suggesting that the parent magmas erupted through the Laurentian margin. The new geochronological and geochemical data are integrated with a subsidence model and data from the hinterland to refine the tectonic model of the Taconic orogeny. Closure of the Iapetus Ocean by 475 Ma via collision of the peri-Gondwanan Moretown terrane with hyperextended distal fragments of the Laurentian margin is not clearly manifested on the autochthon or the Taconic allochthon other than an increase in sediment accumulation. Pro-foreland basins formed during the Middle Ordovician when these terranes were obducted onto the Laurentian margin. 466 to 464 Ma ashes on the Laurentian margin coincide with a late pulse of magmatism in both the Notre Dame arc in Newfoundland and the Shelburne Falls arc of New England that is potentially related to break-off of an east-dipping slab. Following slab reversal, by 455 Ma, the Bronson Hill arc was established on the new composite Laurentian margin. Thus, we conclude that Late Ordovician strata in the Mohawk Valley and Taconic allochthon of New York and on the Humber margin of Newfoundland were deposited in retro-foreland basins
B cells require DOCK8 to elicit and integrate T cell help when antigen is limiting
Dedicator of cytokinesis 8 (DOCK8) immunodeficiency syndrome is characterized by a failure of the germinal center response, a process involving the proliferation and positive selection of antigen-specific B cells. Here, we describe how DOCK8-deficient B cells are blocked at a light-zone checkpoint in the germinal centers of immunized mice, where they are unable to respond to T cellâdependent survival and selection signals and consequently differentiate into plasma cells or memory B cells. Although DOCK8-deficient B cells can acquire and present antigen to initiate activation of cognate T cells, integrin up-regulation, B cellâT cell conjugate formation, and costimulation are insufficient for sustained B cell and T cell activation when antigen availability is limited. Our findings provide an explanation for the failure of the humoral response in DOCK8 immunodeficiency syndrome and insight into how the level of available antigen modulates B cellâT cell cross-talk to fine-tune humoral immune responses and immunological memory
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