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Effect of acute experimental hand pain on left-right discrimination response latency for hand recognition
No full textBackground: Recent work has indicated that acute experimental pain affects left-right discrimination latency. This phenomenon highlights an effect of pain on the cortex that may have significant clinical importance in the form of pain state assessment. However, to date only limited study has further qualified this effect. A more thorough understanding of the magnitude and characteristics of this phenomenon is needed to determine its potential clinical utility.Objective: This study aimed to closely replicate previous studies investigating response latency changes for left-right discrimination judgements as a result of acute experimental pain.Methods: Twenty-two right-handed participants (n = 11 female, n = 11 male) free from pain, analgesia use, pain-related conditions, upper limb trauma/conditions, visual impairment, and dyslexia took part in this study. Participants completed a hand left-right discrimination judgement task before, during, and after an experimental pain stimulus was delivered to each hand separately. Experimental pain was achieved using an intramuscular injection of hypertonic (5%) saline into the thenar eminence of the left and right hands. Mean response times for the left-right discrimination task were determined and compared for pain location (right, left), pain condition (before, during, after), and image laterality (right, left). Pain intensity was rated at 20 s intervals during each left-right discrimination task.Results: A main effect of pain condition (p = 0.028) confirmed that pain intensity was significantly higher in the during pain condition compared to the before pain and after pain conditions. A main effect of image laterality (p = 0.002) further showed that response latency for right-hand pain was significantly shorter compared to left-hand pain. No significant interaction between the factors pain location and image laterality (p = 0.086) was found. For right-hand pain, response latencies for the unaffected hand were, however, descriptively greater compared to the affected hand, and this was not the case for left-hand pain. Furthermore, no main effect of pain stimulus or of pain location on response times was found (p = 1.00 and p = 0.202, respectively).Conclusion: Our results were not consistent with previous hand left-right discrimination response latency results and may cast doubt on the attentional bias hypothesis that is currently considered to underpin response latency changes during acute experimental hand pain. Individual responses to pain, subsets of participants, and differing mental rotation strategies during the left-right discrimination task may have influenced the results
A review of protocols for the experimental release of kelp (Laminariales) zoospores
No full textKelps (order Laminariales) are foundation species in temperate and arctic seas globally, but they are in decline in many places. Laminarian kelp have an alternation of generations and this poses challenges for experimental studies due to the difficulties in achieving zoospore release and gametophyte growth. Here, we review and synthesize the protocols that have been used to induce zoospore release in kelps to identify commonalities and provide guidance on best practices. We found 171 papers, where zoospore release was induced in four kelp families from 35 different ecoregions. The most commonly treated family was Laminariaceae, followed by Lessoniaceae and the most studied ecoregion was Central Chile, followed by the Southern California Bight. Zoospore release generally involved three steps: a pretreatment which included cleaning of the reproductive tissue to eliminate epiphytic organisms, followed by desiccation of the tissue, and finally a postdesiccation immersion of the reproductive material in a seawater medium for zoospore release. Despite these commonalities, there was a high degree of variation in the detail within each of these steps, even among studies within genera and from the same ecoregions. This suggests either that zoospore release may be relatively insensitive across the Laminariales or that little methods optimization has been undertaken. We suggest that greater attention to standardization of protocols and reporting of methodology and optimization would improve comparisons of kelp zoospore release across species and locations and facilitate a broader understanding of this key, but understudied life history stage
From multi-target anticoagulants to DOACs, and intrinsic coagulation factor inhibitors
No full textFrom the 1940s to 1990s, heparin and warfarin have been the main anticoagulants for the prevention and treatment of thrombotic events. Since then, LMWHs and fondaparinux proved effective in clinical trials, with better pharmacokinetic profiles and no monitoring requirements. Developed in the early 21st century, DOACs have comparable efficacy to LMWHs, but increase bleeding risk, as the anticoagulant targets (FIIa, FXa) are also essential for physiological hemostasis. In contrast, selective inhibition of the intrinsic coagulation pathway may be a promising strategy for safer antithrombotic treatment. FXII, FXI and FIX inhibitors have produced favorable results in preclinical studies. Notably, intrinsic F.Xase is another promising candidate target, yet to be systematically evaluated. Here, we review the development of anticoagulants, including recent research on intrinsic F.Xase inhibitors, and the revision of coagulation models over time. Studies support optimism for future diversification of anticoagulants, which could offer more reliable and patient-specific therapy
Antimony speciation and mobility during Fe(II)-induced transformation of humic acid-antimony(V)-iron(III) coprecipitates*
No full textAntimony, as the Sb(V) species, often occurs in oxic soils and sediments as coprecipitates with poorly-crystalline Fe(III)-bearing minerals. It is common for these Sb(V)-Fe(III) coprecipitates to also contain varying quantities of co-occurring humic acid (HA). When exposed to reducing conditions, the production of Fe(II) may cause the initial metastable HA-Sb(V)-Fe(III) phases to undergo rapid transformations to more stable phases, thereby potentially influencing the geochemical behavior of coprecipitated Sb(V). However, little is known about the impacts of this transformation on the mobility and speciation of Sb. In this study, we reacted synthetic HA-Sb(V)-Fe(III) coprecipitates (Fe:Sb ratio = 4, and C:Fe molar ratios = 0, 0.3, 0.8 and 1.3) with 0, 1 or 10 mM Fe(II) under O2-free conditions at pH 7.0 for 15 days. Fe K-edge EXAFS spectroscopy revealed that solid-phase Fe(III) in the initial coprecipitates contained a mixture of ∼4/5 ferrihydrite (Fe10O14(OH)2) and ∼1/5 tripuhyite (FeSbO4), regardless of the corresponding amount of coprecipitated HA. Tripuhyite persisted throughout the full experiment duration, while ferrihydrite was partially replaced by goethite (FeOOH) when either 1 or 10 mM Fe(II)aq was added to the coprecipitates. The greatest level of goethite formation (∼55% of solid-phase Fe) was observed in the HA-free/10 mM Fe(II)aq treatment, with ferrihydrite transformation being partially attenuated at higher levels of HA. Mobilisation of aqueous Sb was the greatest for 1 mM Fe(II) treatments at high HA:Fe ratios. Sb K-edge XANES spectroscopy showed that the largest reduction of Sb(V) to Sb(III) (∼37%) and the greatest repartitioning of Sb to the mineral surface (∼7.9–9.8%) occurred in the coprecipitates with the highest HA contents in the presence of 10 mM Fe(II). The results indicate that the amount of HA in HA-Sb(V)-Fe(III) coprecipitates can greatly influence mobility and speciation of Sb in Fe(II)-rich conditions. The results of this study provide new insights into alterations in Sb mobility and retention in response to Fe cycling under organic matter-rich reducing conditions
Carbon dynamics in plants, debris and soil in different vegetation types and management systems
No full textThis thesis evaluated the biological and ecological conditions associated with carbon sequestration in different vegetation types, as well as assessed some effects of land use change and silvicultural management. Average carbon sequestration in undisturbed and disturbed (selectively logged) rainforests corresponded to 1,487 and 1,261 tCO2e- ha-1 respectively, being the vegetation type with the largest sink potential. Land use conversion from pastures to hardwood plantations increased carbon storage, where E. dunnii and C. citriodora unthinned stands stored 588 and 630 tCO2e- ha-1 respectively, i.e. 18% more sequestered carbon than thinned stands, and 73-85% more than adjacent pastures (340 tCO2e- ha-1)
Are methane emissions from mangrove stems a cryptic carbon loss pathway? Insights from a catastrophic forest mortality
No full textGrowing evidence indicates that tree‐stem methane (CH4) emissions may be an important and unaccounted‐for component of local, regional and global carbon (C) budgets. Studies to date have focused on upland and freshwater swamp‐forests; however, no data on tree‐stem fluxes from estuarine species currently exist. Here we provide the first‐ever mangrove tree‐stem CH4 flux measurements from \u3e50 trees (n = 230 measurements), in both standing dead and living forest, from a region suffering a recent large‐scale climate‐driven dieback event (Gulf of Carpentaria, Australia). Average CH4 emissions from standing dead mangrove tree‐stems was 249.2 ± 41.0 μmol m−2 d−1 and was eight‐fold higher than from living mangrove tree‐stems (37.5 ± 5.8 μmol m−2 d−1). The average CH4 flux from tree‐stem bases (c. 10 cm aboveground) was 1071.1 ± 210.4 and 96.8 ± 27.7 μmol m−2 d−1 from dead and living stands respectively. Sediment CH4 fluxes and redox potentials did not differ significantly between living and dead stands. Our results suggest both dead and living tree‐stems act as CH4 conduits to the atmosphere, bypassing potential sedimentary oxidation processes. Although large uncertainties exist when upscaling data from small‐scale temporal measurements, we estimated that dead mangrove tree‐stem emissions may account for c. 26% of the net ecosystem CH4 flux
Identification of SNP loci and candidate genes related to four important fatty acid composition in Brassica napus using genome wide association study
No full textRapeseed oil (canola, Brassica napus L.) is an important healthy vegetable oil throughout the world, the nutritional and economical value of which largely depends on its seed fatty acid composition. In this study, based on 201,187 SNP markers developed from the SLAF-seq (specific locus amplified fragment sequencing), a genome wide association study of four important fatty acid content traits (erucic acid, oleic acid, linoleic acid and linolenic acid) in a panel of 300 inbred lines of rapeseed in two environments (JXAU and JXRIS) was carried out. A total of 148 SNP loci significantly associated with these traits were detected by MLM model analysis respectively, and 30 SNP loci on A08 and C03 chromosomes were detected in three traits of erucic acid, oleic acid and linoleic acid contents simultaneously. Furthermore, 108 highly favorable alleles for increasing oleic acid and linoleic acid content, also for decreasing erucic acid content simultaneously were observed. By a basic local alignment search tool (BLAST) search with in a distance of 100 Kb around these significantly SNP-trait associations, we identified 20 orthologs of the functional candidate genes related to fatty acid biosynthesis, including the known vital fatty acid biosynthesis genes of BnaA.FAE1 and BnaC. FAE1 on the A08 and C03 chromosomes, and other potential candidate genes involving in the fatty acid biosynthesis pathway, such as the orthologs genes of FAD2, LACS09, KCS17, CER4, TT16 and ACBP5. This study lays a basis for uncovering the genetic variations and the improvement of fatty acid composition in B. napus