367 research outputs found
Sensitivity of the mussel Mytilus edulis to substrate‑borne vibration in relation to anthropogenically generated noise
© 2015 Inter-Research. Many anthropogenic activities in the oceans involve direct contact with the seabed (for example pile driving), creating radiating particle motion waves. However, the consequences of these waveforms to marine organisms are largely unknown and there is little information on the ability of invertebrates to detect vibration, or indeed the acoustic component of the signal. We quantified sensitivity of the marine bivalve Mytilus edulis to substrate-borne vibration by exposure to vibration under controlled conditions. Sinusoidal excitation by tonal signals at frequencies within the range 5 to 410 Hz was applied during the tests, using the 'staircase' method of threshold determination. Thresholds were related to mussel size and to seabed vibration data produced by anthropogenic activities. Clear behavioural changes were observed in response to the vibration stimulus. Thresholds ranged from 0.06 to 0.55 m s -2 (acceleration, root mean squared), with valve closure used as the behavioural indicator of reception and response. Thresholds were shown to be within the range of vibrations measured in the vicinity of anthropogenic operations such as pile driving and blasting. The responses show that vibration is likely to impact the overall fitness of both individuals and mussel beds of M. edulis due to disruption of natural valve periodicity, which may have ecosystem and commercial implications. The observed data provide a valuable first step to understanding the impacts of such vibration upon a key coastal and estuarine invertebrate which lives near industrial and construction activity, and illustrate that the role of seabed vibration should not be underestimated when assessing the impacts of noise pollution
Research Notes : Genetic linkage analysis
The Rj2 gene (Caldwell, 1966), which conditions ineffective nodulation wtth strains of the cl and 122 serogroup of Rhizobium japonicum (Kirchner) Buhanan, and the Rj4 gene (Vest and Caldwell, 1972), conditioning an inef-fective nodulation response with rhizobial strain 61 of the Beltsville Culture Collection R. japonicum, were tested for linkage association with the gene L1 (black pod). The rj1 gene (Williams and Lynch, 1954), conditon-. ing a non-nodulating response with a broad spectrum of strains of R. Japonicum, was tested for linkage with the gene fr (roots nonfluorescent in UV light) and L1 (black pod). The gene y9 (chlorophyll defective) was tested for possible linkage with the genes ln (narrow leaf), and P1 (glabrous). The P1 gene was also tested for linkage with the gene fr
Research notes: Genetic analysis of factors controlling nodulation response in soybeans
Two of the genes controlling nodulation response in soybeans were tested for linkage associations with genes controlling pubescence color (T) and flower color (W1 ), chlorophyll deficiency (y9 ) and absence of pubescence (P). The rj1 gene (W1lliams and Lynch, 1954) in homozygous recessive condition results in a non-nodulating phenotype with a broad spectrum of Rhizobium japonicum strains. The dominant gene, Rj4 (Vest and Caldwell, 1972) conditions an ineffective nodulation response when inoculated specifically with R. japonicum strain 61 of the Beltsville Culture Collection
Exposure of benthic invertebrates to sediment vibration: From laboratory experiments to outdoor simulated pile-driving
This is the final version of the article. Available from Acoustical Society of America via the DOI in this record.Fourth International Conference on the Effects of Noise on Aquatic Life, Dublin, Ireland, 10-16 July 2016Activities directly interacting with the seabed, such as pile-driving, can produce vibrations that have the potential to impact benthic invertebrates within their vicinity. This stimuli may interfere with crucial behaviors such as foraging and predator avoidance, and the sensitivity to vibration is largely unknown. Here, the responsiveness of benthic invertebrates to sediment vibration is discussed in relation to laboratory and semi-field trials with two marine species: the mussel (Mytilus edulis) and hermit crab (Pagurus bernhardus). Sensory threshold curves were produced for both species in controlled laboratory conditions, followed by small-scale pile-driving exposures in the field. The merits of behavioral indicators are discussed, in addition to using physiological measures, as a method of determining reception and measuring responses. The measurement and sensors required for sediment vibration quantification are also discussed. Response and threshold data were related to measurements taken in the vicinity of anthropogenic sources, allowing a link between responsiveness and actual operations. The impact of pile-driving on sediment-dwelling invertebrates has received relatively little research, yet the data here suggest that such activities are likely to impact key coastal species which play important roles within the marine environment.LR would like to thank the organizers and sponsors of the 2016 conference for
supporting her attendance for which she is extremely grateful. This study was partially
funded by a research award from the Malacological Society of London to LR. The
authors would also like to acknowledge Defra and NERC who funded the laboratory and
field work aspects respectively, and the staff at the OREC field site, Blyth
Quantifying the retention of emotions across story retellings
Story retelling is a fundamental medium for the transmission of information between individuals and among social groups. Besides conveying factual information, stories also contain affective information. Though natural language processing techniques have advanced considerably in recent years, the extent to which machines can be trained to identify and track emotions across retellings is unknown. This study leverages the powerful RoBERTa model, based on a transformer architecture, to derive emotion-rich story embeddings from a unique dataset of 25,728 story retellings. The initial stories were centered around five emotional events (joy, sadness, embarrassment, risk, and disgust—though the stories did not contain these emotion words) and three intensities (high, medium, and low). Our results indicate (1) that RoBERTa can identify emotions in stories it was not trained on, (2) that the five emotions and their intensities are preserved when they are transmitted in the form of retellings, (3) that the emotions in stories are increasingly well-preserved as they experience additional retellings, and (4) that among the five emotions, risk and disgust are least well-preserved, compared with joy, sadness, and embarrassment. This work is a first step toward quantifying situation-driven emotions with machines
HIV infection and aging: enhanced Interferon- and Tumor Necrosis Factor-alpha production by the CD8(+) CD28(-) T subset
BACKGROUND: T cells from HIV(+) and aged individuals show parallels in terms of suppressed proliferative activity and interleukin-2 (I1-2) production and an increased number of CD8(+) CD28(-) T cells. In order to compare cytokine production from T cells from these two states, CD4(+) and CD8(+) T cells from HIV(+) aged, and normal young donors (controls) were monitored for cytokine production by flow cytometry, quantitative PCR and ELISA upon activation by PMA and anti-CD3. In addition, the CD8(+) T cell subsets CD28(+) and CD28(-) from the HIV(+) and the aged groups were evaluated for cytokine production by flow cytometry, and compared with those from young controls. RESULTS: Flow cytometric analysis indicated that CD8(+) T cells from both HIV(+) and aged donors showed an increase of approximately 2–3 fold over controls in percentage of cells producing inflammatory cytokines IFN-γ and TNF-α. Similar analysis also revealed that the production of interleukins-4,6 and 10, production was very low (1–2% of cells) and unchanged in these cells. Quantitative PCR also showed a substantial increase (4–5 fold) in IFN-γ and TNF-α mRNA from HIV(+) and aged CD8(+) T cells, as did ELISA for secreted IFN-γ and TNF-α (2.3–4 fold). Flow cytometric analysis showed that the CD8(+) CD28(-) T cell subset accounts for approximately 80–86% of the IFN-γ and TNF-α production from the CD8(+) subset in the aged and HIV(+) states. The CD4(+) T cell, while not significantly changed in the HIV(+) or aged states in terms of IFN-γ production, showed a small but significant increase in TNF-α production in both states. CONCLUSIONS: Our data appear compatible with physiologic conditions existing in HIV(+) and aged individuals, i.e. elevated serum levels and elevated CD8(+) T cell production of IFN-γ and TNF-α. Thus, the capacity for increased production of cytokines IFN-γ and TNF-α in the aged individual by the dominant CD8(+) CD28(-) subset may have a profound influence on the clinical state by aggravating inflammatory pathologies such as rheumatoid arthritis, and possibly Alzheimer's disease and Crohn's disease. In AIDS, these cytokines may contribute to wasting and cachexia. We theorize that the predominant phenotypic change to the cytotoxic CD8(+) CD28(-) T cell subsets in both the HIV(+) and the aged states may reflect a natural "endpoint" in CD8(+) T cell differentiation induced after a lifetime of immune activity (toward viruses, etc) in the aged, and after a massive accelerated response to HIV in the HIV-positive individual
Effects of Syngenta Enogen Feed Corn containing an α-amylase trait on finishing cattle performance and carcass characteristics
Two experiments evaluated the effects of feeding a new corn hybrid, containing an α-amylase enzyme trait, Syngenta Enogen Feed Corn (SYT-EFC), on feedlot performance and carcass characteristics at two locations. Experiment 1 utilized 300 calffed steers (298.5 ± 16.3 kg of BW) at the University of Nebraska–Lincoln Eastern Nebraska Research and Extension Center Mead, NE. Treatments were designed as a 2 × 2 + 1– factorial arrangement with factors consisting of 1) corn type (SYT-EFC or conventional [CON]) and 2) byproduct type (with or without Sweet Bran [SB]), or a BLEND of STY-EFC and CON without SB. In Exp. 2, 240 crossbred, calf-fed steers (287.6 ± 15.4 kg of BW) were utilized at the University of Nebraska–Lincoln Panhandle Research and Extension Center near Scottsbluff, NE. Steers were fed SYT-EFC, CON, BLEND, or CON with a commercial α-amylase enzyme supplement (CON-E). In Exp. 1, there was an interaction for ADG (P = 0.05) and G:F (P = 0.02). Steers fed SYT-EFC with SB had greater ADG and G:F than CON; however, in diets without SB, SYT-EFC and CON were not different resulting in a 10.1% change in G:F when steers were fed SYT-EFC in SB compared with CON and only 1.6% change between SYT-EFC and CON without SB. Energy values, based on performance data, resulted in a 6.5% and 8.3% change in NEm and NEg, respectively, for steers fed SYT-EFC and CON with SB and 1.6% change for both NEm and NEg for steers fed SYT-EFC and CON without SB. For the main effect of corn trait, steers fed SYT-EFC had greater marbling scores, fat depth, and calculated yield grade compared with CON (P ≤ 0.03). In diets without SB, there was no difference between SYT-EFC, CON, or BLEND for DMI, final BW, ADG, G:F, NEm, or NEg (P ≥ 0.35). In Exp. 2, cattle fed SYT-EFC, BLEND, or CON-E had greater final BW, ADG, and G:F than cattle fed CON (P ≤ 0.03). On average, NEm and NEg were 4.9% and 7.0% greater, respectively, for steers fed amylase enzyme treatments compared with CON (P ≤ 0.01). Hot carcass weights were greater in steers fed α-amylase treatments compared with CON (P \u3c 0.01). Feeding Syngenta Enogen Feed Corn, which contains an α-amylase enzyme trait, at both locations improved feed efficiency in finishing cattle diets containing WDGS or SB
Compellingly high SARS-CoV-2 susceptibility of Golden Syrian hamsters suggests multiple zoonotic infections of pet hamsters during the COVID-19 pandemic
Golden Syrian hamsters (Mesocricetus auratus) are used as a research model for severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2). Millions of Golden Syrian hamsters are also kept as pets in close contact to humans. To determine the minimum infective dose (MID) for assessing the zoonotic transmission risk, and to define the optimal infection dose for experimental studies, we orotracheally inoculated hamsters with SARS-CoV-2 doses from 1 * 105 to 1 * 10-4 tissue culture infectious dose 50 (TCID50). Body weight and virus shedding were monitored daily. 1 * 10-3 TCID50 was defined as the MID, and this was still sufficient to induce virus shedding at levels up to 102.75 TCID50/ml, equaling the estimated MID for humans. Virological and histological data revealed 1 * 102 TCID50 as the optimal dose for experimental infections. This compelling high susceptibility leading to productive infections in Golden Syrian hamsters must be considered as a potential source of SARS-CoV-2 infection for humans that come into close contact with pet hamsters
Using DNA metabarcoding to investigate diet and niche partitioning in the native European otter (Lutra lutra) and invasive American mink (Neovison vison)
In the UK, the native European otter ( Lutra lutra ) and invasive American mink ( Neovison vison ) have experienced concurrent declines and expansions. Currently, the otter is recovering from persecution and waterway pollution, whereas the mink is in decline due to population control and probable interspecific interaction with the otter. We explored the potential of DNA metabarcoding for investigating diet and niche partitioning between these mustelids. Otter spraints ( n = 171) and mink scats ( n = 19) collected from three sites (Malham Tarn, River Hull, and River Glaven) in northern and eastern England were screened for vertebrates using high-throughput sequencing. Otter diet mainly comprised aquatic fishes (81.0%) and amphibians (12.7%), whereas mink diet predominantly consisted of terrestrial birds (55.9%) and mammals (39.6%). The mink used a lower proportion (20%) of available prey ( n = 40 taxa) than the otter, and low niche overlap (0.267) was observed between these mustelids. Prey taxon richness of mink scats was lower than otter spraints, and beta diversity of prey communities was driven by taxon turnover (i.e. the otter and mink consumed different prey taxa). Considering otter diet only, prey taxon richness was higher in spraints from the River Hull catchment, and beta diversity of prey communities was driven by taxon turnover (i.e. the otter consumed different prey taxa at each site). Studies using morphological faecal analysis may misidentify the predator as well as prey items. Faecal DNA metabarcoding can resolve these issues and provide more accurate and detailed dietary information. When upscaled across multiple habitat types, DNA metabarcoding should greatly improve future understanding of resource use and niche overlap between the otter and mink
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