187 research outputs found

    Pemanfaatan Teknologi Informasi untuk Sistem Informasi Manajemen Sekolah: Studi Kasus pada SMA 78 Jakarta

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    Databases to manage data related to student and school are required to support the implemented information technology applications. This study aims to analyze and design a database system that supports the school management information systems, especially for SMA 78 Jakarta as a case study. Included in the system are the students and teachers data management, the management of school tuition, and the management of learning materials and assignments for students. This research uses data collection methods, with a literature study, questionnaires, interviews, observation, and studying the data obtained from the school. Analyses were performed on the results of questionnaires, interviews and observations to identify user needs. The design used conceptual and logical database system design. The result achieved is the application for school management information system that can be used by students, teachers and school officials in supporting learning process and school administration. The developed application is expected to be a medium for students and teachers to share information in teaching and learning activities and administrative processes

    Impact of reactive surfaces on the abiotic reaction between nitrite and ferrous iron and associated nitrogen and oxygen isotope dynamics

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    Anaerobic nitrate-dependent Fe(II) oxidation (NDFeO) is widespread in various aquatic environments and plays a major role in iron and nitrogen redox dynamics. However, evidence for truly enzymatic, autotrophic NDFeO remains limited, with alternative explanations involving the coupling of heterotrophic denitrification with the abiotic oxidation of structurally bound or aqueous Fe(II) by reactive intermediate nitrogen (N) species (chemodenitrification). The extent to which chemodenitrification is caused (or enhanced) by ex vivo surface catalytic effects has not been directly tested to date. To determine whether the presence of either an Fe(II)-bearing mineral or dead biomass (DB) catalyses chemodenitrification, two different sets of anoxic batch experiments were conducted: 2 mM Fe(II) was added to a low-phosphate medium, resulting in the precipitation of vivianite (Fe3(PO4)2), to which 2 mM nitrite (NO−2) was later added, with or without an autoclaved cell suspension (∼1.96×108 cells mL−1) of Shewanella oneidensis MR-1. Concentrations of nitrite (NO−2), nitrous oxide (N2O), and iron (Fe2+, Fetot) were monitored over time in both set-ups to assess the impact of Fe(II) minerals and/or DB as catalysts of chemodenitrification. In addition, the natural-abundance isotope ratios of NO−2 and N2O (δ15N and δ18O) were analysed to constrain the associated isotope effects. Up to 90 % of the Fe(II) was oxidized in the presence of DB, whereas only ∼65 % of the Fe(II) was oxidized under mineral-only conditions, suggesting an overall lower reactivity of the mineral-only set-up. Similarly, the average NO−2 reduction rate in the mineral-only experiments (0.004±0.003 mmol L−1 d−1) was much lower than in the experiments with both mineral and DB (0.053±0.013 mmol L−1 d−1), as was N2O production (204.02±60.29 nmol L−1 d−1). The N2O yield per mole NO−2 reduced was higher in the mineral-only set-ups (4 %) than in the experiments with DB (1 %), suggesting the catalysis-dependent differential formation of NO. N-NO−2 isotope ratio measurements indicated a clear difference between both experimental conditions: in contrast to the marked 15N isotope enrichment during active NO−2 reduction (15εNO2=+10.3 ‰) observed in the presence of DB, NO−2 loss in the mineral-only experiments exhibited only a small N isotope effect (<+1 ‰). The NO−2-O isotope effect was very low in both set-ups (18εNO2 <1 ‰), which was most likely due to substantial O isotope exchange with ambient water. Moreover, under low-turnover conditions (i.e. in the mineral-only experiments as well as initially in experiments with DB), the observed NO−2 isotope systematics suggest, transiently, a small inverse isotope effect (i.e. decreasing NO−2 δ15N and δ18O with decreasing concentrations), which was possibly related to transitory surface complexation mechanisms. Site preference (SP) of the 15N isotopes in the linear N2O molecule for both set-ups ranged between 0 ‰ and 14 ‰, which was notably lower than the values previously reported for chemodenitrification. Our results imply that chemodenitrification is dependent on the available reactive surfaces and that the NO−2 (rather than the N2O) isotope signatures may be useful for distinguishing between chemodenitrification catalysed by minerals, chemodenitrification catalysed by dead microbial biomass, and possibly true enzymatic NDFeO

    Impact of reactive surfaces on the abiotic reaction between nitrite and ferrous iron and associated nitrogen and oxygen isotope dynamics

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    © The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Visser, A., Wankel, S. D., Niklaus, P. A., Byrne, J. M., Kappler, A. A., & Lehmann, M. F. Impact of reactive surfaces on the abiotic reaction between nitrite and ferrous iron and associated nitrogen and oxygen isotope dynamics. Biogeosciences, 17(16), (2020): 4355-4374, doi:10.5194/bg-17-4355-2020.Anaerobic nitrate-dependent Fe(II) oxidation (NDFeO) is widespread in various aquatic environments and plays a major role in iron and nitrogen redox dynamics. However, evidence for truly enzymatic, autotrophic NDFeO remains limited, with alternative explanations involving the coupling of heterotrophic denitrification with the abiotic oxidation of structurally bound or aqueous Fe(II) by reactive intermediate nitrogen (N) species (chemodenitrification). The extent to which chemodenitrification is caused (or enhanced) by ex vivo surface catalytic effects has not been directly tested to date. To determine whether the presence of either an Fe(II)-bearing mineral or dead biomass (DB) catalyses chemodenitrification, two different sets of anoxic batch experiments were conducted: 2 mM Fe(II) was added to a low-phosphate medium, resulting in the precipitation of vivianite (Fe3(PO4)2), to which 2 mM nitrite (NO−2) was later added, with or without an autoclaved cell suspension (∼1.96×108 cells mL−1) of Shewanella oneidensis MR-1. Concentrations of nitrite (NO−2), nitrous oxide (N2O), and iron (Fe2+, Fetot) were monitored over time in both set-ups to assess the impact of Fe(II) minerals and/or DB as catalysts of chemodenitrification. In addition, the natural-abundance isotope ratios of NO−2 and N2O (δ15N and δ18O) were analysed to constrain the associated isotope effects. Up to 90 % of the Fe(II) was oxidized in the presence of DB, whereas only ∼65 % of the Fe(II) was oxidized under mineral-only conditions, suggesting an overall lower reactivity of the mineral-only set-up. Similarly, the average NO−2 reduction rate in the mineral-only experiments (0.004±0.003 mmol L−1 d−1) was much lower than in the experiments with both mineral and DB (0.053±0.013 mmol L−1 d−1), as was N2O production (204.02±60.29 nmol L−1 d−1). The N2O yield per mole NO−2 reduced was higher in the mineral-only set-ups (4 %) than in the experiments with DB (1 %), suggesting the catalysis-dependent differential formation of NO. N-NO−2 isotope ratio measurements indicated a clear difference between both experimental conditions: in contrast to the marked 15N isotope enrichment during active NO−2 reduction (15εNO2=+10.3 ‰) observed in the presence of DB, NO−2 loss in the mineral-only experiments exhibited only a small N isotope effect (<+1 ‰). The NO−2-O isotope effect was very low in both set-ups (18εNO2 <1 ‰), which was most likely due to substantial O isotope exchange with ambient water. Moreover, under low-turnover conditions (i.e. in the mineral-only experiments as well as initially in experiments with DB), the observed NO−2 isotope systematics suggest, transiently, a small inverse isotope effect (i.e. decreasing NO−2 δ15N and δ18O with decreasing concentrations), which was possibly related to transitory surface complexation mechanisms. Site preference (SP) of the 15N isotopes in the linear N2O molecule for both set-ups ranged between 0 ‰ and 14 ‰, which was notably lower than the values previously reported for chemodenitrification. Our results imply that chemodenitrification is dependent on the available reactive surfaces and that the NO−2 (rather than the N2O) isotope signatures may be useful for distinguishing between chemodenitrification catalysed by minerals, chemodenitrification catalysed by dead microbial biomass, and possibly true enzymatic NDFeO.This research has been supported by the Deutsche Forschungsgemeinschaft (DFG; grant no. GRK 1708, “Molecular principles of bacterial survival strategies”) and the University of Basel, Switzerland

    Using the <i>Mus musculus</i> hybrid zone to assess covariation and genetic architecture of limb bone lengths

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    Two subspecies of the house mouse, Mus musculus domesticus and Mus musculus musculus, meet in a narrow contact zone across Europe. Mice in the hybrid zone are highly admixed, representing the full range of mixed ancestry from the two subspecies. Given the distinct morphologies of these subspecies, these natural hybrids can be used for genomewide association mapping at sufficiently high resolution to directly infer candidate genes. We focus here on limb bone length differences, which is of special interest for understanding the evolution of developmentally correlated traits. We used 172 first-generation descendants of wild-caught mice from the hybrid zone to measure the length of stylopod (humerus/femur), zeugopod (ulna/tibia) and autopod (metacarpal/metatarsal) elements in skeletal CT scans. We find phenotypic covariation between limb elements in the hybrids similar to patterns previously described in Mus musculus domesticus inbred strains, suggesting that the hybrid genotypes do not influence the covariation pattern in a major way. Mapping was performed using 143,592 SNPs and identified several genomic regions associated with length differences in each bone. Bone length was found to be highly polygenic. None of the candidate regions include the canonical genes known to control embryonic limb development. Instead, we are able to identify candidate genes with known roles in osteoblast differentiation and bone structure determination, as well as recently evolved genes of, as yet, unknown function. © 2018 John Wiley Sons Ltd

    Reversible Light-Induced Dimerization of Secondary Face Azobenzene-Functionalized β-Cyclodextrin Derivatives

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    β-cyclodextrin (βCyD) derivatives equipped with aromatic appendages at the secondary face exhibit tailorable self-assembling capabilities. The aromatic modules can participate in inclusion phenomena and/or aromatic-aromatic interactions. Supramolecular species can thus form that, at their turn, can engage in further co-assembling with third components in a highly regulated manner; the design of nonviral gene delivery systems is an illustrative example. Endowing such systems with stimuli responsiveness while keeping diastereomeric purity and a low synthetic effort is a highly wanted advancement. Here, we show that an azobenzene moiety can be “clicked” to a single secondary O-2 position of βCyD affording 1,2,3-triazole-linked βCyD-azobenzene derivatives that undergo reversible light-controlled self-organization into dimers where the monomer components face their secondary rims. Their photoswitching and supramolecular properties have been thoroughly characterized by UV-vis absorption, induced circular dichroism, nuclear magnetic resonance, and computational techniques. As model processes, the formation of inclusion complexes between a water-soluble triazolylazobenzene derivative and βCyD as well as the assembly of native βCyD/βCyD-azobenzene derivative heterodimers have been investigated in parallel. The stability of the host-guest supramolecules has been challenged against the competitor guest adamantylamine and the decrease of the medium polarity using methanol-water mixtures. The collective data support that the E-configured βCyD-azobenzene derivatives, in aqueous solution, form dimers stabilized by the interplay of aromatic-aromatic and aromatic-βCyD cavity interactions after partial reciprocal inclusion. Photoswitching to the Z-isomer disrupts the dimers into monomeric species, offering opportunity for the spatiotemporal control of the organizational status by light.Ministerio de Ciencia e Innovación PID2019-105858RB-I00, PID2020-118403GB-I00, PID2020-118384GB-I00, PID2020-119130GB-I00Fondo Europeo de Desarrollo Regional PID2021-124247OB-C21Junta de Andalucía P20_00166, US-1380698, P12-FQM-1467Universidad de Sevilla FPU18/02922, FPU19/0436

    Circulating endothelial cell count: a reliable marker of endothelial damage in patients undergoing hematopoietic stem cell transplantation

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    The physio-pathologic interrelationships between endothelium and GvHD have been better elucidated and have led to definition of the entity 'endothelial GvHD' as an essential early phase prior to the clinical presentation of acute GvHD. Using the CellSearch system, we analyzed circulating endothelial cells (CEC) in 90 allogeneic hematopoietic stem cell transplantation (allo-HSCT) patients at the following time-points: T1 (pre-conditioning), T2 (pre-transplant), T3 (engraftment), T4 (onset of GvHD) and T5 (1 week after steroid treatment). Although CEC changes in allo-HSCT represent a dynamic phenomenon influenced by many variables (that is, conditioning, immunosuppressive treatments, engraftment syndrome and infections), we showed that CEC peaks were constantly seen at onset of acute GvHD and invariably returned to pre-transplant values after treatment response. Since we showed that CEC changes during allo-HSCT has rapid kinetics that may be easily missed if blood samples are drawn at pre-fixed time-points, we rather suggest an 'on demand' evaluation of CEC counts right at onset of GvHD clinical symptoms to possibly help differentiate GvHD from other non-endothelial complications. We confirm that CEC changes are a suitable biomarker to monitor endothelial damage in patients undergoing allo-transplantation and hold the potential to become a useful tool to support GvHD diagnosis (ClinicalTrials.gov NCT02064972).Bone Marrow Transplantation advance online publication, 11 September 2017; doi:10.1038/bmt.2017.194

    Multifactorial Analysis of Differences Between Sporadic Breast Cancers and Cancers Involving BRCA1 and BRCA2 Mutations

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    Background: We have previously demonstrated that breast cancers associated with inherited BRCA1 and BRCA2 gene mutations differ from each other in their histopathologic appearances and that each of these types differs from breast cancers in patients unselected for family history (i.e., sporadic cancers). We have now conducted a more detailed examination of cytologic and architectural features of these tumors. Methods: Specimens of tumor tissue (5-µm-thick sections) were examined independently by two pathologists, who were unaware of the case or control subject status, for the presence of cell mitosis, lymphocytic infiltration, continuous pushing margins, and solid sheets of cancer cells; cell nuclei, cell nucleoli, cell necrosis, and cell borders were also evaluated. The resulting data were combined with previously available information on tumor type and tumor grade and further evaluated by multifactorial analysis. All statistical tests are two-sided. Results: Cancers associated with BRCA1 mutations exhibited higher mitotic counts (P = .001), a greater proportion of the tumor with a continuous pushing margin (P<.0001), and more lymphocytic infiltration (P = .002) than sporadic (i.e., control) cancers. Cancers associated with BRCA2 mutations exhibited a higher score for tubule formation (fewer tubules) (P = .0002), a higher proportion of the tumor perimeter with a continuous pushing margin (P<.0001), and a lower mitotic count (P = .003) than control cancers. Conclusions: Our study has identified key features of the histologic phenotypes of breast cancers in carriers of mutant BRCA1 and BRCA2 genes. This information may improve the classification of breast cancers in individuals with a family history of the disease and may ultimately aid in the clinical management of patients. [J Natl Cancer Inst 1998;90:1138-45
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