The global ocean is a significant sink for anthropogenic carbon (Cant), absorbing roughly a third of human CO2 emitted over the industrial period. Robust estimates of the magnitude and variability of ...the storage and distribution of Cant in the ocean are therefore important for understanding the human impact on climate. In this synthesis we review observational and model-based estimates of the storage and transport of Cant in the ocean. We pay particular attention to the uncertainties and potential biases inherent in different inference schemes. On a global scale, three data-based estimates of the distribution and inventory of Cant are now available. While the inventories are found to agree within their uncertainty, there are considerable differences in the spatial distribution. We also present a review of the progress made in the application of inverse and data assimilation techniques which combine ocean interior estimates of Cant with numerical ocean circulation models. Such methods are especially useful for estimating the air–sea flux and interior transport of Cant, quantities that are otherwise difficult to observe directly. However, the results are found to be highly dependent on modeled circulation, with the spread due to different ocean models at least as large as that from the different observational methods used to estimate Cant. Our review also highlights the importance of repeat measurements of hydrographic and biogeochemical parameters to estimate the storage of Cant on decadal timescales in the presence of the variability in circulation that is neglected by other approaches. Data-based Cant estimates provide important constraints on forward ocean models, which exhibit both broad similarities and regional errors relative to the observational fields. A compilation of inventories of Cant gives us a "best" estimate of the global ocean inventory of anthropogenic carbon in 2010 of 155 ± 31 PgC (±20% uncertainty). This estimate includes a broad range of values, suggesting that a combination of approaches is necessary in order to achieve a robust quantification of the ocean sink of anthropogenic CO2.
Glial-cell line derived neurotrophic factor (GDNF) bound to its co-receptor GFRα1 stimulates the RET receptor tyrosine kinase, promoting neuronal survival and neuroprotection. The GDNF-GFRα1 complex ...also supports synaptic cell adhesion independently of RET. Here, we describe the structure of a decameric GDNF-GFRα1 assembly determined by crystallography and electron microscopy, revealing two GFRα1 pentamers bridged by five GDNF dimers. We reconsitituted the assembly between adhering liposomes and used cryo-electron tomography to visualize how the complex fulfils its membrane adhesion function. The GFRα1:GFRα1 pentameric interface was further validated both in vitro by native PAGE and in cellulo by cell-clustering and dendritic spine assays. Finally, we provide biochemical and cell-based evidence that RET and heparan sulfate cooperate to prevent assembly of the adhesion complex by competing for the adhesion interface. Our results provide a mechanistic framework to understand GDNF-driven cell adhesion, its relationship to trophic signalling, and the central role played by GFRα1.
Aim
To identify the diagnostic accuracy of gingival crevicular fluid (GCF) candidate biomarkers to discriminate periodontitis from the inflamed and healthy sites, and to compare the performance of ...two independent matrix metalloproteinase (MMP)‐8 immunoassays.
Materials and Methods
Cross sectional study. GCF (N = 58 sites) was collected from healthy, gingivitis and chronic periodontitis volunteers and analysed for levels of azurocidin, chemokine ligand 5, MPO, TIMP‐1 MMP‐13 and MMP‐14 by ELISA or activity assays. MMP‐8 was assayed by immunofluorometric assay (IFMA) and ELISA. Statistical analysis was performed using linear mixed‐effects models and Bayesian statistics in R and Stata V11.
Results
MMP‐8, MPO, azurocidin and total MMP‐13 and MMP‐14 were higher in periodontitis compared to gingivitis and healthy sites (p < 0.05). A very high correlation between MPO and MMP‐8 was evident in the periodontitis group (r = 0.95, p < 0.0001). MPO, azurocidin and total levels of MMP‐8, MMP‐13 and MMP‐14 showed high diagnostic accuracy (≥0.90), but only MMP‐8 and MPO were significantly higher in the periodontitis versus gingivitis sites. MMP‐8 determined by IFMA correlated more strongly with periodontal status and showed higher diagnostic accuracy than ELISA.
Conclusions
MPO and collagenolytic MMPs are highly discriminatory biomarkers for site‐specific diagnosis of periodontitis. The comparison of two quantitative MMP‐8 methods demonstrated IFMA to be more accurate than ELISA.
Song learning has evolved within several avian groups. Although its evolutionary advantage is not clear, it has been proposed that song learning may be advantageous in allowing birds to adapt their ...songs to the local acoustic environment. To test this hypothesis, we analysed patterns of song adjustment to noisy environments and explored their possible link to song learning. Bird vocalizations can be masked by low‐frequency noise, and birds respond to this by singing higher‐pitched songs. Most reports of this strategy involve oscines, a group of birds with learning‐based song variability, and it is doubtful whether species that lack song learning (e.g. suboscines) can adjust their songs to noisy environments. We address this question by comparing the degree of song adjustment to noise in a large sample of oscines (17 populations, 14 species) and suboscines (11 populations, 7 species), recorded in Brazil (Manaus, Brasilia and Curitiba) and Mexico City. We found a significantly stronger association between minimum song frequency and noise levels (effect size) in oscines than in suboscines, suggesting a tighter match in oscines between song transmission capacity and ambient acoustics. Suboscines may be more vulnerable to acoustic pollution than oscines and thus less capable of colonizing cities or acoustically novel habitats. Additionally, we found that species whose song frequency was more divergent between populations showed tighter noise–song frequency associations. Our results suggest that song learning and/or song plasticity allows adaptation to new habitats and that this selective advantage may be linked to the evolution of song learning and plasticity.
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•Spray application of mycoinsecticides produce transient colonization of plants.•Transient colonizations improve the control of Spodoptera littoralis larvae.•Spray applications and ...their transient colonizations produce additive effects.
The current work reports how spray application of entomopathogenic fungi on alfalfa, tomato and melon plants may cause an additional Spodoptera littoralis larvae mortality due to a temporal colonization of the leaves and subsequent ingestion of those leaves by the larvae. Most entomopathogenic fungi (EF) (Ascomycota: Hypocreales) endophytes seem to colonize their host plants in a non-systemic pattern, in which case at least a transient endophytic establishment of the fungus should be expected in treated areas after spray application. In this work, all strains were able to endophytically colonize roots, stems and leaves during the first 96h after inoculation. Whilst the treatment of S. littoralis larvae with a 108ml−1 conidial suspension resulted in moderate to high mortality rates for the Metarhizium brunneum EAMb 09/01-Su (41.7–50.0%) and Beauveria bassiana EABb 01/33-Su (66.7–76.6%) strains, respectively, an additive effect was detected when these larvae were also fed endophytically colonized alfalfa, tomato, and melon leaves, with mortality rates varying from 25.0% to 46.7% as a function of the host plant and total mortality rates in the combined treatment of 75–80% and 33–60% for B. bassiana and M. brunneum, respectively. Fungal outgrowth was not detected in any of the dead larvae feeding on colonized leaves, whereas traces of destruxin A were detected in 11% of the insects fed tomato discs endophytically colonized by M. brunneum. The combined effects of the fungal spray with the mortality caused by the feeding of insects on transient EF-colonized leaves have to be considered to estimate the real acute impact of field sprays with entomopathogenic fungi on chewing insects.
Brain metabolomics is an emerging field that complements the more traditional approaches of neuroscience. However, typical brain metabolomics workflows require that animals be sacrificed and tend to ...involve tedious sample preparation steps. Microdialysis, the standard technique to study brain metabolites in vivo, is encumbered by significant limitations in the analysis of hydrophobic metabolites, which are prone to adsorption losses on microdialysis equipment. An alternative sampling method suitable for in vivo brain studies is solid-phase microextraction (SPME). In SPME, a small probe coated with a biocompatible polymer is employed to extract/enrich analytes from biological matrices. In this work, we report the use of SPME and liquid chromatography–mass spectrometry for untargeted in vivo analysis of rodent’s brains after deep brain stimulation (DBS). First, metabolite changes occurring in brain hippocampi after application of 3 h of DBS to the animals’ prefrontal cortex were monitored with the proposed approach. As SPME allows for nonlethal sampling, the same group of animals was sampled again after 8 days of daily DBS therapy. After acute DBS, we detected changes in a broad range of metabolites, including the amino acid citrulline, which may reflect changes in nitric oxide production, as well as various phospho- and glycosphingolipids. Measurements conducted after chronic DBS showed a decrease in hippocampal corticosterone, indicating that DBS may have a regulatory effect in the hypothalamic–pituitary–adrenal axis. Our findings demonstrate the potential of in vivo SPME as a tool of scientific and clinical interest capable of revealing changes in a wide range of metabolites in brain tissue.
Understanding trust between dairy farmers and other actors in the dairy chain, as well as the reciprocity norms among them are fundamental to encouraging collective action and decision-making to ...improve milk production and udder health. The objective of this study was to understand the relationships of trust between dairy farmers and other actors in the dairy chain related to udder health in the north of Antioquia. Mixed methods (cross-sectional and grounded theory) with a convergent triangulation design were used. A total of 216 dairy farmers participated in the quantitative component, and 17 dairy farmers and 9 veterinarians in the qualitative component, they were located in 9 milk-producing municipalities in the north of Antioquia. A characterization survey of the dairy farmers, a survey on reliability and udder health, an analysis of each farm's annual average BTSCC and CFU, and semi-structured interviews on the same topic were conducted. Problems were found in the biological indicators of udder health on the farms: BTSCC was poor for 67% of the dairy farmers, and CFU was poor for 22% of the dairy farmers. Veterinarians are the actors whom dairy farmers trust the most. Trust in dairy chain actors is complex, variable, and depends on many aspects. Trust representation, Socio-cultural Factors, Economic and Commercial Factors, Labor, Clinical and Laboratory Conditions of Milk, and Norms of Reciprocity constitute the categories of analysis when theorizing about trust and udder health. Each of the theoretical and emerging categories in this study describes actors, attitudes, behaviors, relationships between actors, and norms, allowing us to understand that trust between dairy farmers and other actors in the dairy chain in order to face the problems of udder health and milk production depends on technical processes, individual and collective human attitudes and behaviors, supply of services, political, regulative and economic determinants, the latter being transcendental in decision-making to invest in mastitis control and udder health care.
The hypothalamic-pituitary axis (HP axis) plays a critical and integrative role in the endocrine system control to maintain homeostasis. The HP axis is responsible for the hormonal events necessary ...to regulate the thyroid, adrenal glands, gonads, somatic growth, among other functions. Endocrine-disrupting chemicals (EDCs) are a worldwide public health concern. There is growing evidence that exposure to EDCs such as bisphenol A (BPA), some phthalates, polychlorinated biphenyls (PCBs), polybrominated diphenyl ethers (PBDEs) and biphenyls (PBBs), dichlorodiphenyltrichloroethane (DDT), tributyltin (TBT), and atrazine (ATR), is associated with HP axis abnormalities. EDCs act on hormone receptors and their downstream signaling pathways and can interfere with hormone synthesis, metabolism, and actions. Because the HP axis function is particularly sensitive to endogenous hormonal changes, disruptions by EDCs can alter HP axis proper function, leading to important endocrine irregularities. Here, we review the evidence that EDCs could directly affect the mammalian HP axis function.
The Mediterranean recluse spider, Loxosceles rufescens (Dufour, 1820) (Araneae: Sicariidae) is a cosmopolitan spider that has been introduced in many parts of the world. Its bite can be dangerous to ...humans. However, the potential distribution of this alien species, which is able to spread fairly quickly with human aid, is completely unknown. Using a combination of global and regional niche models, it is possible to analyse the spread of this species in relation to environmental conditions. This analysis found that the successful spreading of this species varies according to the region invaded. The majority of populations in Asia are stable and show niche conservatism, whereas in North America this spider is expected to be less successful in occupying niches that differ from those in its native region and that do not support its synanthropic way of living.
The global distribution of Loxosceles rufescens (Araneae: Sicariidae) was analysed by comparing global and regional niche models.
Temperature was important in both models: the highest contributor to the global model was ‘annual mean temperature’ (Bio1, 68.1%), whereas the most important variable in the regional models (including the native area) was ‘mean diurnal range’ (Bio2).
The global model predicted the probability of presence was highest (0.7–1.0) for Mediterranean North Africa and for Europe, high in invaded areas of Asia, and low and medium in the warmer climates of the U.S.A. (Florida) and southeastern Brazil.
To date, solid-phase microextraction (SPME) fibers used for in vivo bioanalysis can be too fragile and flexible, which limits suitability for direct tissue sampling. As a result, these devices often ...require a sheathing needle to prepuncture robust sample matrixes and protect the extraction phase from mechanical damage. To address this limitation, a new SPME device is herein presented which incorporates an extraction phase recessed into the body of a solid needle. This device requires no additional support or shielding during puncture events through protective tissue. The presented device was thoroughly tested, being fired at 90 m·s–1 through fish scales, forced through vial septa, and employed in a targeted study of polyunsaturated fatty acids in salmon where the protective outer skin was repetitively punctured during sampling. Finally, the recessed SPME device was applied to an on-site application for the tissue analysis of wild muskellunge. With this advancement, rapid, minimally invasive, and easily executed in vivo SPME is now possible opening the door to near endless sampling opportunities.
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