Characterization of a Phosphonate-Specific Cytidylyltransferase

Antibiotic resistance is a major global health concern that requires new therapeutic approaches. Furthermore, a lack of narrow spectrum antibiotics on the market produces unintended consequences with respect to changes in our microbial make up. Phosphonates are reduced versions of phosphates that possess a C-P bond which is more resistant to enzymatic and chemical degradation. The role of phosphonate containing macromolecules (e.g. cell surface polysaccharides) remains enigmatic, however their presence suggests that they may confer an advantage. The biosynthesis of phosphonate-containing macromolecules is unknown, but a pathway is proposed involving aLicC type cytidylyltransferase-catalyzed conjugation to a phosphonate followed by a LicD type phosphotransferase- catalyzed attachment to a macromolecule. This proposed pathway is analogous to the partially characterized phosphocholine (PC) tailoring pathway in teichoic acid biosynthesis in Streptococcus pneumoniae. In this study, the LicC homolog PngC from Atopobium rimae (Ari-PngC) was purified and its activity was compared to LicC from S. pneumoniae (Spn-LicC). Significantly, Ari-PngC preferred the phosphonate substrate 2-aminoethylphosphonate (AEP) over PC, and vice versa for Spn-LicC. Specifically, the KM and kcat values for Spn-LicC towards PC were 0.020 ±0.011 mM and 1.52 ± 0.243 s-1 respectively, yielding kcat/KM of 77.9 M-1 s-1. In contrast, the KM value for Spn-LicC towards AEP was 0.318 ± 0.126 mM and kcat of 0.722 ± 0.053 s-1, yielding kcat/km of 2.27 M-1 s-1 and revealing a 34-fold preference for PC. The opposite was seen for Ari-PngC, where AEP gave a KM value of 0.011 ± 0.001 mM , kcat of 2.72 ± 0.079 s-1 and kcat/KM of 239 M-1 s-1, while towards PC Ari-PngC yielded specificity constants of 1.67 and 0.74 when modelled by the Michaelis-Menten or substrate inhibition equation, respectively. Regardless of the correct fit, PngC clearly preferred AEP over PC. Overall, these results establish clear substrate selectivity of phosphonate versus PC tailoring pathways and set the stage for developing narrow spectrum antimicrobials

Lignin and lignin-acetoderivative oxidative degradation into valuable aromatic aldehydes

本项工作研究了木质素的转化以及其副产品(乙酸基衍生物)转变为高附加值的芳香醛，乙酸基衍生物在碱性条件下催化氧化降解的动力学方程等问题。竹材木质素被转化为高附加值的芳香醛和乙酸基衍生物。在铜作为催化剂的条件下，香草乙酮被转化为香草醛。另外，乙酰丁香酮首次转化为丁香醛，从而通过降解木质素氧化过程中的副产物来提高整个过程的价值。本文用GC-MS分析得到了一种可靠的一致的相对影响因子法来定量木质素和乙酸衍生物。竹材木质素的总产率接近9.5%，且香草醛的产率为55%，其中90%以上来自于香草乙酮。来源于木质素，通过降解乙酸衍生物而得到高附加值的芳香醛分为两步反应。文章首次研究了120-150℃条件下香草...The main objective of this work was to study the transformation of lignin and its by-products (acetoderivatives) into valuable aromatic aldehydes as well as the kinetics of acetoderivative degradation during the alkaline catalytic oxidation. Bamboo lignin was transformed into valuable aromatic aldehydes and acetoderivatives. Vanillin was recovered from acetovanillone with the application of copper...学位：工程硕士院系专业：化学化工学院_化学工程学号：2042013115452

An Assessment of Workplace Bullying Practice and its Effect to Teachers Performance in Tanzania. A Case Study of Selected Secondary School at Temeke Municipality

Workplace bullying has become a problem that is too costly to ignore. Many studies indicate that workplace bullying leads to pain, mental distress, physical illness, emotional harm, and career damage. The focus of this study on workplace bullying provides an opportunity to understand workplace bullying practice and its effect to Teacher’s performance in Tanzania. A case study of selected secondary School at Temeke Municipality. The study sample comprised of 80 respondents. Closed questionnaire data which were collected through questionnaire were analyzed by SPSS using descriptive analysis. Data which were collected through interview method were analysed by content analysis. The respondents were sampled using simple random and purposive sampling technique. The findings indicate that bullying practice is very common in education system. The findings indicate that teachers are bullied in the form of delaying their payment, promotion, delay of release to study and inappropriate special duty among teachers. The study recommends to reviewing the Human Resources structure and leadership especially at regional and district level. There should be regular training, workshops and seminars to train education officials on the effect of workplace bullying to the development of education. The framework for an external expert panel to investigate serious allegations of bullying and harassment among teachers should be developed. Teachers should be awarded according to their acknowledge and contribution in education development. Teachers should be promoted and paid their arrears on time

Numerical simulation of colloidal dispersion filtration: description of critical flux and comparison with experimental results

During filtration via membrane processes, colloids accumulate at the porous surface leading to fouling phenomena. In this study, a rigorous simulation of momentum and mass transfer using CFD modelling has been developed to describe such an accumulation during cross flow filtration. These simulations integrate detailed modeling of physicochemical properties specific to colloidal dispersions (because of the surface interactions (repulsive and attractive) occurring between the colloids particles). These interactions are accounted for via the experimental variation of the colloidal osmotic pressure with volume fraction (associated with a variation in the diffusion coefficient) which are fitted by a relationship integrated into the CFD code. It contains a description of the colloidal phase transition leading to the formation of a condensed phase (deposit or gel layer) from the accumulated dispersed phase (concentration polarization). It is then possible to determine the critical flux which separates filtration conditions below which mass accumulation is reversible (in the dispersed phase) and above which it is irreversible (in the condensed phase). The computed value of critical flux is compared with that determined experimentally for a dispersion of latex particles

CASSANDRA: drug gene association prediction via text mining and ontologies

The amount of biomedical literature has been increasing rapidly during the last decade. Text mining techniques can harness this large-scale data, shed light onto complex drug mechanisms, and extract relation information that can support computational polypharmacology. In this work, we introduce CASSANDRA, a fully corpus-based and unsupervised algorithm which uses the MEDLINE indexed titles and abstracts to infer drug gene associations and assist drug repositioning. CASSANDRA measures the Pointwise Mutual Information (PMI) between biomedical terms derived from Gene Ontology (GO) and Medical Subject Headings (MeSH). Based on the PMI scores, drug and gene profiles are generated and candidate drug gene associations are inferred when computing the relatedness of their profiles. Results show that an Area Under the Curve (AUC) of up to 0.88 can be achieved. The algorithm can successfully identify direct drug gene associations with high precision and prioritize them over indirect drug gene associations. Validation shows that the statistically derived profiles from literature perform as good as (and at times better than) the manually curated profiles. In addition, we examine CASSANDRA’s potential towards drug repositioning. For all FDA-approved drugs repositioned over the last 5 years, we generate profiles from publications before 2009 and show that the new indications rank high in these profiles. In summary, co-occurrence based profiles derived from the biomedical literature can accurately predict drug gene associations and provide insights onto potential repositioning cases

Los anglicismos en el español de la economía y los negocios

http://tartu.ester.ee/record=b2694491~S1*es

Stimulating private sector to provide SMART solutions for rural water supply

After limited success with supply-driven approaches, government of Uganda is pursuing a self supply approach to water, sanitation and hygiene (WASH) services through the private sector. This paper highlights the strategies and lessons learned by World Vision Uganda (WVU) in implementing a comprehensive self supply market-based approach to water services that encompassed all the four pillars of self supply. Private enterprises were identified in a competitive and fun process and trained to provide sustainable market-based appropriate and reliable technologies (SMART) for water supply. WVU conducted awareness and demand creation campaigns on self supply using low-cost water technologies. Private enterprises and households signed contracts. Low cost technologies promoted were Baptist drilling and rope pumps for boreholes. The results showed that households are willing to pay for their own water supply if there are appropriate and affordable water supply technologies

Pemisahan Berkas Perkara (Splitsing) pada Tindak Pidana Korupsi Proyek Hambalang (Studi Putusan Nomor 62/Pid.Sus/TPK /2013/PN.Jkt.Pst.)

Kesejahteraan umum sebagai salah satu tujuan negara, dalam upaya pencapaiannya diperlukan suatu alat yaitu keuangan negara. Korupsi merupakan penyakit utama penghambat tercapainya kesejahteraan umum yang berbasis pada keuangan negara. Metode yang digunakan dalam penelitian ini adalah yuridis normatif dengan pendekatan perundangundangan. Spesifikasi penelitian yang digunakan adalah deskriptif analisis. Data yang digunakan adalah data sekunder yang berupa peraturan perundangundangan, buku-buku literatur, putusan hakim, dan situs-situs internet. Dalam mengumpulan data sekunder digunakan metode studi kepustakaan dan dalam menganalisis data sekunder digunakan metode normatif kualitatif. Permasalahan yang akan dibahas adalah mengenai penggunaan cara penyusunan berkas perkara dengan pemisahan berkas perkara (splitsing) dalam perkara tindak pidana korupsi Hambalang, serta konsekuensi yang akan terjadi dari dilakukannya pemisahan berkas perkara (splitsing) tersebut. Penegakkan hukum terhadap tindak pidana korupsi dalam hal kurangnya alat bukti saksi suatu delik penyertaan, salah satu contohnya ialah perkara tindak pidana korupsi proyek pusat pendidikan, Pelatihan dan Sekolah Olahraga Nasional (P3SON) Hambalang. Beberapa faktor yang mempengaruhi pertimbangan penuntut umum dalam melakukan pemisahan berkas perkara atau splitsing, serta menjadi dasar penyidik memecah perkara ialah perbuatan tindak pidana tersebut dilakukan tanpa adanya saksi dan/atau kurang didukung adanya alat bukti yang sah lainnya; pelaku tindak pidana tersebut terdiri dari beberapa orang, selain itu splitsing juga meringankan tugas jaksa penuntut umum dalam menyusun tuntutan dengan dipecahnya suatu perkara, agar dapat diperoleh berkas perkara yang sempurna, akan tetapi dilakukannya splitsing bukan tanpa resiko. Beberapa hal yang merupakan konsekuensi dari dilakukannya splitsing ialah Perbedaan penerapan hukum; Pelanggaran hak memungkiri (azas non self incrimination); pelanggaran asas praduga tak bersalah (presumption of innocence) dan kaburnya unsur penyertaan (deelneming)