Sorting Out the Details: The Roles of a Novel GlyGly-CTERM Domain, Rhombosortase, and the Type II Secretion System in Surface Localization of a Vibrio cholerae serine protease, VesB.

Some proteins carry recognition motifs that allow them to be sorted into different compartments of the cell. In Gram-positive bacteria, proteins with the LPXTG sorting motif are localized to the cell surface where they are attached to peptidoglycan by a membrane bound cysteine protease called sortase. The work presented here entails a novel Gram-negative sorting mechanism that includes the rhombosortase protease and the C-terminal recognition motif, GlyGly-CTERM. GlyGly-CTERM domains contain serines and glycines, followed by a stretch of hydrophobic and positively charged residues. The composition of this domain makes it an ideal candidate to span the membrane and serve as a possible substrate for rhombosortase, a rhomboid-like protease. Rhomboid proteases are intramembrane serine proteases that cleave substrates with a single transmembrane domain that contains helix-destabilizing residues. With this information, we postulated that rhombosortase cleaves and promotes cell surface association of GlyGly-CTERM containing proteins similar to sortase. In order to test this hypothesis, the GlyGly-CTERM containing protein Vibrio extracellular serine protease B (VesB) was utilized. VesB contains an N-terminal signal peptide, a protease domain that includes the propeptide and the catalytic triad, and a C-terminal domain with the GlyGly-CTERM extension. VesB is a trypsin-like serine protease that has an apparent preference for arginine and cleaves both peptides and intact proteins. Using activity assays, western blotting, proteomic analysis and fluorescent microscopy, these studies showed that the type II secretion (T2S) system is responsible for outer membrane translocation of VesB, while rhombosortase promotes its surface retention by cleaving the GlyGly-CTERM domain and perhaps further modifying the newly generated C-terminus of VesB. It was demonstrated that native VesB in a rhombosortase mutant and VesB produced without its GlyGly-CTERM domain were inactive and no longer cell-associated. This latter finding suggests that removal of the N-terminal propeptide and thereby activation of VesB occurs on the cell surface. Taken together, rhombosortase cleaves and promotes cell surface retention of the GlyGly-CTERM domain containing protein, VesB, thereby highlighting a novel protein sorting mechanism in Gram-negative bacteria.PhDMicrobiology & ImmunologyUniversity of Michigan, Horace H. Rackham School of Graduate Studieshttp://deepblue.lib.umich.edu/bitstream/2027.42/108933/1/sgadwal_1.pd

Extreme Physics via X-rays from Black Holes and `Neutron' Stars

A combination of microchannel plate optics and a 32x32 pixel microcalorimeter would allow the successor to the Rossi XTE to explore new domains of spectroscopic timing in a MIDEX class mission. With ~10 times the area and ~100 times the spectral resolution of the PCA (and 10 times that of silicon detectors) such a mission would be able to explore redshifts and plasma conditions in weak line features over a wide range of celestial sources. This would allow several tests of basic physics, both QED/QCD and GR.Comment: 3 pages, 0 figures; for procedings of the `2nd International Conference on Particle and Fundamental Physics in Space

Exploring Two Phases of Design-by-Analogy "Multiple Solutions" and "Multiple Analogies"

Idea generation and design-by-analogy are core parts of design. Designers need tools to assist them in developing creative and innovative ideas. Analogy is one such tool that helps designers solve design problems. It is a stimulus that helps generate innovative solutions to a design problem. It is used to generate novel ideas by transferring information (i.e. mapping elements) from a known domain (base) to an unknown domain (target). Multiple solutions can be developed based on a single analog and designers derive principles of design from the analogs (products) they experience. There is little research that discusses creating multiple solutions from a single analog or how multiple analogs can assist designers in mapping high level principles of design. Multiple paths are available to improve the design-by-analogy process and help designers understand the process better. This thesis explores two phases of design-by-analogy in which designers have difficulty generating multiple inferences from a single source analog and identifying high level principles given multiple example analogs in the presence of noise. Two hypotheses are proposed to explore the importance of analogies in design. 1. A lone designer is able to generate multiple inferences from a single source analog when instructed to do so. 2. The mapping of high level principles increases with the increase in the number of example analogs and decreases with the amount of noise. Two experiments, "Multiple Solutions" and "Multiple Analogies" are conducted to answer the proposed research questions and to understand how designers can become better analogical reasoners. The results from the "Multiple Solutions" experiment show that engineers, when directed to, can create multiple solutions from a single analog. Results from the "Multiple Analogies" experiment also satisfy the hypothesis that the mapping of high level principles increases with an increase in the number of analogs and decreases with distracters. A significant interaction is also observed between these two factors. The results indicate more future work with a greater sample size

Peri conceptional association of the triad of hyperhomocsteinemia, hypothyroidism and impaired carbohydrate metabolism with recurrent pregnancy loss

Background: Recurrent pregnancy loss is a cause of great concern to the affected couple as well as the treating physician. We evaluated the periconceptional association of the triad of hyperhomocystienemia, hypothyroidism, and impaired carbohydrate metabolism with RPL and to identify the potential risk factors for RPL which are probably nutritional.Methods: Seven hundred ninety-six consecutive pregnancies with two or more abortions referring to our Infertility clinic were selected to be studied in a descriptive, prospective observational study in 2012-2014. All the pregnant women were subjected to routine blood tests/ examination/ imaging as per hospital protocols. All underwent TSH, FT4, GTT 75 gm (fasting and 2 h postprandial) as per routine antenatal workup. Additionally, fasting plasma homocysteine, antinuclear antibody, anti phospholipid antibody, anti- thyroid peroxidase antibody tests were performed for patients with RPL. All the patients were studied for the triad of hypothyroidism, hyperhomocysteinemia and impaired carbohydrate metabolism.Results: The incidence of RPL was found to be 5.65 %. Majority of women (51.1%) were in the age group 30-34 years. Majority of the women (55.6%) had 2 previous abortions. Majority of women (57.7%) had conceived normally. Majority of women (46.7%) had BMI<25. PCOS was reported in 28.9% women. HHcy, hypothyroidism and impaired carbohydrate metabolism was found in 78%, 73% and 73% women, respectively. The presence of two factors was reported in 60 to 65% women. 56% women reported the presence of the triad. About 7% of the patients underwent repeat abortion in second trimester of which 66.6% had the association of triad.Conclusions: Investigating these three factors in patients with RPL would help in early recognition, monitoring, and aggressive surveillance, which will help prevent obstetric complications. Simple nutritional correction may allow for better maternal and fetal programming and appropriate risk modulation

The two faces of ToxR: activator of ompU , co‐regulator of toxT in Vibrio cholerae

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87152/1/j.1365-2958.2011.07681.x.pdfhttp://deepblue.lib.umich.edu/bitstream/2027.42/87152/2/MMI_7681_sm_FigureS1_TableS1-2.pd

Study of Quality of life of family caregivers of hospitalized COVID-19 patients

Background: High morbidity and mortality due to this virus led to an international health crisis. Whereas frontline health workers, face problems due to increased work load, intense working schedule and increased chance of getting exposed to positive cases, the primary caregivers who are mostly family members and are indispensable in providing support to their member with illness in acute care settings, are also affected in various domains of their functioning. This affects their overall quality of life. Materials and Methods: This cross-sectional observational study was done at Sawai Man Singh and attached hospital, Jaipur. It included 45 caregivers of hospitalized COVID-19 patients. All subjects were evaluated by a general information sheet. WHOQOL-BREF was applied and statistical analysis done by SPSS 23. Results & Conclusion: Factors which were significantly associated with QOL and its domains were duration of illness, duration of hospitalization, severity of COVID-19 illness, occupation and marital status. Duration of illness and hospitalization can be reduced with early identification of illness and effective management which may improve QoL of caregivers. Also, there is need to rotate caregivers among family members and incorporating recreational activities for informal caregivers of Covid-19 patients to improve their Qo