Belize Blue Carbon: Establishing a national carbon stock estimate for mangrove ecosystems.

Mangrove ecosystems are among the most economically and ecologically valuable marine environments in the world. Mangroves are effective at long-term carbon storage within their sediments and are estimated to hold 12 billion metric tons of carbon worldwide. These ecosystems are therefore vitally important for carbon sequestration and, by extension, climate change mitigation. As part of the Paris Agreement, participating countries agree to provide plans to reduce their carbon emissions, or nationally determined contributions (NDCs). However, despite mangroves being recognized as important nature-based solutions, many countries still lack national data on carbon stocks and must use global or regional averages, which may not be sufficiently accurate. Here, we present the national carbon stock estimate of mangrove ecosystems for the NDC of Belize, acquired through a collaborative approach involving government agencies and NGOs. We conducted a comprehensive sampling of mangroves across the country, including a range of mangrove ecotypes. The mean total ecosystem carbon stock (TECS) for the nation was 444.1 ± 21.0 Mg C ha-1, with 74.4 ± 6.2 Mg C ha-1 in biomass stocks, and 369.7 ± 17.7 Mg C ha-1 in sediment stocks. Combining these data with a recent mapping effort, we provide the first national comprehensive mangrove carbon stock estimate of 25.7 Tg C. The national mean from this study varies from previous global analyses, which can under- or overestimate TECS by as much as 0.6 Tg C and 16.5 Tg C, respectively, depending on the study. These data supported the NDC update of Belize, and can be used to inform the country's mangrove protection and restoration commitments. The collaborative approach of this work should serve as a blueprint for other countries seeking to conserve natural blue carbon sinks as a strategy to achieve their climate targets.

Development of the materials analysis and particle probe for Proto-MPEX.

The Prototype Material Plasma Exposure eXperiment (Proto-MPEX) is a linear plasma device being used in plasma source research and development (R&D) for the proposed MPEX. Once the R&D is completed, this device can also be used to perform plasma-material interaction studies. To perform these studies, a new materials analysis and particle probe (MAPP) has been constructed. The MAPP's components are a sample holder and manipulator and a custom vacuum chamber with ports to facilitate surface chemistry diagnostics. The MAPP's overall design enables rapid sample turnaround and in vacuo surface characterization. The surface analysis vacuum chamber has ports for x-ray photoelectron spectroscopy, thermal desorption spectroscopy, back-scatter ion scattering spectroscopy, forward-scatter ion scattering spectroscopy, and direct recoil spectroscopy. The sample manipulator and holder is a Lesker/UHV Multi-Centre Analytical Stage, which is used to place the samples in the exposure region of the Proto-MPEX or the analysis position in the MAPP vacuum chamber. The sample holder has a heating capability of up to 1200 °C for heated exposure and for desorption studies. In this work, we present the MAPP's design and the first tungsten sample exposure with ex situ analysis that shows a surface deposition layer on the exposed target, highlighting the need for additional in situ measurements on the Proto-MPEX.

Agreement between arterial and peripheral venous lactate levels in the ED: A systematic review.

BACKGROUND: In the Emergency Department, lactate measurement is a useful tool to risk-stratify critically ill patients. However, it is unclear whether arterial or peripheral venous lactate levels can be used interchangeably for this purpose. In this systematic review, we provide an overview of studies investigating the agreement between arterial and peripheral venous lactate levels in the Emergency Department. METHODS: PubMed, Embase, the Cochrane Central Register of Controlled Trials/Wiley, Web of Science/Clarivate Analytics, and references of selected articles were assessed for all studies comparing arterial and peripheral venous lactate levels in adult patients in the emergency department. Two reviewers independently screened all potentially relevant titles and abstracts for eligibility using a standardized data-worksheet. RESULTS: Nine studies were included. Peripheral venous lactate levels tend to be higher than arterial lactate levels with mean differences ranging from 0.18 mmol/l to 1.06 mmol/l. Importantly, poorer agreement occurs in hyperlactatemia. At a cut-of level of 1.6 mmol/l, peripheral venous lactate can rule out arterial hyperlactatemia with a sensitivity between 94% and 100%. At a cut off value of 2 mmol/l, sensitivities of 97% and 100% were found. CONCLUSION: Agreement between arterial and peripheral venous lactate is poor in hyperlactatemia, making peripheral venous lactate an unreliable parameter to use interchangeably in the ED. In clinical practice, peripheral venous lactate can be used as a screening tool to rule out arterial hyperlactatemia at a cut-off value of 2 mmol/l. However, hyperlactatemia should be confirmed using arterial sampling in case of a peripheral venous lactate level > 2 mmol/l.

Keeping safe. Continuous glucose monitoring (CGM) in persons with Type 1 diabetes and impaired awareness of hypoglycaemia: a qualitative study.

AIM: To further our understanding of individual use and experience of continuous glucose monitoring (CGM) in adults with Type 1 diabetes and impaired awareness of hypoglycaemia, we conducted a qualitative study supplementary to a randomized controlled trial, using semi-structured interviews. METHODS: Twenty-three participants of the IN CONTROL trial were interviewed within 4 weeks after the last study visit. The interview centred around experiences of CGM, taking into account the person's expectations prior to the trial. The interview was semi-structured, using open-ended questions and, if needed, prompts were offered to elicit further responses. Using thematic analysis, the interview transcripts were coded independently by three members of the research team. The consolidated criteria for reporting qualitative research (COREQ) were followed. RESULTS: Overall, CGM was experienced as helpful in gaining more insight into glucose variability, and temporarily improved sense of control, reduced distress and made participants less dependent on others. However, some participants experienced confrontation with CGM output as intrusive, while some reported frustration due to failing technique and difficulty trusting the device. Participants reported active and passive self-management behaviours mirroring individual differences in attitudes and coping styles. CONCLUSIONS: In adults with Type 1 diabetes at risk of recurrent hypoglycaemia due to impaired awareness of hypoglycaemia, CGM use enhances a sense of control and safety for most, but not all. Future studies should further explore differential use of CGM in this population in the context of active and passive self-management styles.

Lysosomal cysteine proteases and antigen presentation.

Lysosomal proteinases are involved in two critical stages of MHC class II-mediated antigen presentation, i.e., degradation of invariant chain, a chaperone molecule critical for MHC class II assembly and transport, and generation of class II-binding peptides in the endocytic compartment. We found that two lysosomal cysteine proteinases, cathepsins S and L, were found to be differentially expressed in different types of "professional" and "nonprofessional" antigen presenting cells, including B cells, macrophages, specialized thymic epithelium, intestinal epithelium, and dendritic cells. In this chapter, our recent studies on the role of cathepsin S and L in MHC class II-mediated antigen processing and presentation in these cells types are highlighted.

Cathepsin S regulates the expression of cathepsin L and the turnover of gamma-interferon-inducible lysosomal thiol reductase in B lymphocytes.

Loading of antigenic peptide fragments on major histocompatibility complex class II molecules is essential for generation of CD4(+) T cell responses and occurs after cathepsin-mediated degradation of the invariant chain chaperone molecule. Cathepsins are expressed differentially in antigen presenting cells, and mice deficient in cathepsin S or cathepsin L exhibit severely impaired antigen presentation in peripheral lymphoid organs and the thymus, respectively. To determine whether these defects are due solely to the block in invariant chain cleavage, we used cathepsin-deficient B cells to examine the role of cathepsins S and B in the degradation of other molecules important in the class II presentation pathway. Our data indicate that neither cathepsin S nor B is critical for H-2M degradation or processing of precursor gamma-interferon-inducible lysosomal thiol reductase (GILT) to a mature thiol reductase, but suggest a role for cathepsin S in the turnover of mature GILT and in regulating levels of mature cathepsin L protein in B cells. Despite the presence of mature cathepsin L protein, no enzyme activity could be detected in B cells or dendritic cells. These experiments suggest a novel mechanism by which these functionally important enzymes may be regulated.

Fas ligand costimulates the in vivo proliferation of CD8+ T cells.

Fas ligand (FasL/CD95L/APO-1L) is one of a growing number of TNF family members whose triggering costimulates maximal proliferation of activated T cells. In this study we show that maximal Ag-dependent accumulation of transferred TCR-transgenic CD8(+) T cells requires Fas (CD95/APO-1) expression by the adoptive hosts. Additionally, adoptively transferred FasL(+) CD8(+) T cells demonstrate a 2-fold advantage in Ag-driven expansion over their FasL(-)counterparts. This study illustrates the in vivo role of TCR-dependent FasL costimulation in the Ag-specific proliferation of both heterogeneous and homogeneous populations of primary CD8(+) T cells and long-term CTL lines. Thus, cross-linking FasL on naive and Ag-experienced CD8(+) T cells whose Ag-specific TCRs are engaged is required to drive maximal cellular proliferation in vivo.

Down-regulation of the orphan nuclear receptor ROR gamma t is essential for T lymphocyte maturation.

Thymocyte development is a tightly regulated process. CD4+CD8+ double-positive (DP) immature thymocytes exhibit distinct phenotypic features from mature T cells; they express only 10% of surface TCR that are found on mature T cells and do not proliferate and produce IL-2 in response to stimulation. In this report we show that transgenic expression of the orphan nuclear receptor ROR gamma t in mature T cells down-regulates their surface TCR expression. The ROR gamma t transgene inhibits IL-2 production by mature T cells, and this inhibition may be partially due to the inhibitory effect of ROR gamma t on c-Rel transcription. Furthermore, ectopic expression of ROR gamma t inhibits the proliferation of mature and immature T cells. These results, together with its predominant expression in DP thymocytes, suggest that ROR gamma t controls these distinct phenotypic features of DP thymocytes. Our data suggest that down-regulation of ROR gamma t expression in thymocytes is essential for their maturation.

Structure-function studies of interleukin 15 using site-specific mutagenesis, polyethylene glycol conjugation, and homology modeling.

Interleukin (IL)-15 is a multifunctional cytokine that shares many biological activities with IL-2. This functional overlap, as well as receptor binding subunits shared by IL-15 and IL-2, suggests tertiary structural similarities between these two cytokines. In this study, recombinant human IL-15 was PEGylated via lysine-specific conjugation chemistry in order to extend the circulation half-life of this cytokine. Although PEGylation did extend the beta-elimination circulation half-life of IL-15 by greater than 50-fold, the biological activity of polyethylene glycol (PEG)-IL-15 was significantly altered. Specifically, PEG-IL-15 lost its ability to stimulate the proliferation of CTLL but took on the properties of a specific IL-15 antagonist in vitro. In comparing sequence alignments and molecular models for IL-2 and IL-15, it was noted that lysine residues resided in regions of IL-15 that may have selectively disrupted receptor subunit binding. We hypothesized that PEGylation of IL-15 interferes with beta but not alpha receptor subunit binding, resulting in the IL-15 antagonist activity observed in vitro. The validity of this hypothesis was tested by engineering site-specific mutants of human IL-15 as suggested by the IL-15 model (IL-15D8S and IL-15Q108S block beta and gamma receptor subunit binding, respectively). As with PEG-IL-15, these mutants were unable to stimulate CTLL proliferation but were able to specifically inhibit the proliferation of CTLL in response to unmodified IL-15. These results supported our model of IL-15 and confirmed that interference of beta receptor subunit binding by adjacent PEGylation could be responsible for the altered biological activity observed for PEG-IL-15.

Adjustment of the interface detector (location 71) to the absolute number of mononuclear cells in the peripheral blood: no improvement of the collection efficiency of the Fenwal CS3000 plus during progenitor cell harvests.

Improvement of the collection efficiency (CE) of the Fenwal CS3000 plus in collecting circulating progenitor cells (CPC) might diminish the number of leukapheresis procedures (LP) required to obtain the CPC required to assure engraftment. We analyzed whether adjustment of the optical setting (location 71,L71) to the number of MNC present in the peripheral blood could enhance the CE of the MNC. Thirty-five patients underwent 121 LP with an adjusted L71. We compared the results retrospectively with 26 LP performed with a fixed L71 (1:100) in 12 patients. The CPC were mobilized with chemotherapy followed by subcutaneous administration of granulocyte colony-stimulating factor (G-CSF) in both groups. Adjustment of the L71 did neither improve the CE of the MNC, the estimated CE of CD34+ cells nor diminished granulocyte contamination. For the total 121 LP with an adjusted L71 and for the total 26 LP with a fixed L71 the mean CE of MNC were, respectively, 44.6 +/- 18.3% and 46.4 +/- 14%. The mean granulocyte contamination, determined by manual white blood cell differentiation, was 1.7 +/- 2.3% for the adjusted L71 group and 2.3 +/- 3 for the fixed L71 group. There was no difference in the median number of LP required to obtain 3 x 10(6) CD34+ cells/kg between both groups. We found a weak significant correlation between WBC and pre-LP MNC count and the CE of MNC (r = 0.36, P = 0.012, resp.r = 0.33, P = 0.023), but no correlation between the CE of MNC and the estimated CE of CD34+ cells (r = 0.24, P = 0.113). In conclusion, adjustment of the L71 to the MNC did not improve the CE of MNC of the Fenwal CS3000. The lack of correlation between the CE and MNC and the estimated CE of CD34+ cells should be further explored.

Cloning of a T cell growth factor that interacts with the beta chain of the interleukin-2 receptor.

A cytokine was identified that stimulated the proliferation of T lymphocytes, and a complementary DNA clone encoding this new T cell growth factor was isolated. The cytokine, designated interleukin-15 (IL-15), is produced by a wide variety of cells and tissues and shares many biological properties with IL-2. Monoclonal antibodies to the beta chain of the IL-2 receptor inhibited the biological activity of IL-15, and IL-15 competed for binding with IL-2, indicating that IL-15 uses components of the IL-2 receptor.

Stable and sensitive method for the simultaneous determination of N5-methyltetrahydrofolate, leucovorin, methotrexate and 7-hydroxymethotrexate in biological fluids.

A high-performance liquid chromatographic method for the determination of N5-methyltetrahydrofolic acid, leucovorin, methotrexate and 7-hydroxymethotrexate in plasma and liquor samples is presented. Gradient elution is used to increase the sensitivity. Four sample preparation methods were compared with respect to the stability of the injectable sample. Samples can be pretreated with a simple deproteinization method. For enhanced selectivity a solid-phase extraction procedure is described.

Formation constants of mercury(II) with some buffer/masking agents and the formation of mixed-ligand complexes.

Values are given for the formation constants of complexes of mercury(II) with some buffer/masking agents. The mixed-ligand complex formation of mercury(II)-chelates with other complexing agents has also been studied.