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DIETARY DIVERSITY and NUTRITIONAL STATUS OF INFANT AND YOUNG CHILDREN AGED 6 - 23 MONTHS AT BARDAGHAT MUNICIPALITY IN NAWALPARASI DISTRICT - NEPAL.
No full textThis presentation was from 6th Annual scientific Symposium in Nepal
Environmental Enteric Dysfunction, Aflatoxin Exposure, and Poor Growth Outcomes in Uganda.
No full textThis presentation, given at the First Scientific Symposium in Uganda, uses data collected by the Nutrition Innovation Lab
Annual linear growth velocities of preschool children by age and sex in the Terai of Nepal: A three-year cohort study.
No full textThe poster was presented in ASN 2018
Silk Fiber Films for the Slow and Continuous Release of Tetracycline and Doxycycline
No full textAbstract: Aim: To assess the potential use of silk-based films for the slow and continuous release of tetracycline and doxycycline for use in periodontal or other surgical procedures. Hypothesis: We hypothesize that silk-based films will allow for long-term release of antibiotics. Material and Method: Tetracycline and doxycycline were mixed, at various concentrations, with the silk solution. Antibiotic loaded silk fiber films were incubated with Streptococcus mutans cultures to assess the release of the antibiotics. Chlorhexidine was used as a positive control and plain silk films without antibiotic as a negative control. Bacterial growth inhibition was measured spectrophotometrically after each consecutive 24-hour incubation period. The number of colony forming units (CFUs) was determined to validate growth inhibition. Results: Tetracycline and doxycycline-loaded silk fiber films inhibited S. mutans growth in a concentration and time-dependent manner. Tetracycline with the concentrations of 0.375, 0.75 and 1.5 mg/mL inhibited S. mutans growth with noticeable release up to three, four and five days, respectively. Doxycycline with the concentrations of 0.375, 0.75 and 1.5 mg/mL inhibited S. mutans growth up to six, ten and eleven days, respectively. The colony forming units for the 1.5 mg/mL doxycycline and tetracycline exposed S. mutans cultures were 1.2x106 and 1.8x106 CFUs/mL, respectively, which are markedly less compared to the uninhibited control cultures which contained 3.5x109 CFUs/mL. Conclusions: We concluded that tetracycline and doxycycline can be successfully loaded into silk fiber films and inhibited bacterial growth with significant release up to five days for tetracycline and eleven days for doxycycline. Our data implies that silk fiber loaded films can be used as a medium for the localized delivery of antibiotics during periodontal and oral surgeries.Thesis (M.S.)--Tufts University, 2018.Submitted to the Dept. of Dental Medicine.Advisor: Driss Zoukhri.Committee: Gerard Kugel, Tofool Alghanem, Sarah E. Pagni, and Aidee N. Herman.Keyword: Dentistry
Application of Whole Genome Sequencing and Bioinformatics Tools to Investigate Novel Interactions in DNA Repair in Drosophila melanogaster
No full textAbstract: An organism's genome is constantly exposed to endogenous and exogenous forms of damage. If left unrepaired, DNA damage can pose a threat to the regulation and function of genes located near the site of the lesion. To address the multiple types of DNA damage that accumulate on a daily basis, organisms have evolved specific pathways to deal with each one. Although most of these pathways have been studied for multiple years or even decades, there are still many interactions and mechanisms that have yet to be elucidated. In recent years, the study of genomes and their maintenance has changed significantly thanks to drastic improvements to DNA sequencing technologies and the corresponding data analysis tools. In the work described here, whole genome sequencing (WGS) and bioinformatic data analysis were used to address two research questions, each of which focused on investigating DNA repair proteins and their roles in DNA repair and genomic stability in Drosophila melanogaster. First, I investigated the cause of a synthetic larval lethality, which was discovered after creating double mutants for two conserved helicases: DmBlm and DmHelQ. Second, I analyzed mutants obtained from an ethyl-methane sulfonate (EMS) mutagenesis screen that was conducted in a trans-lesion synthesis (TLS)-deficient background, in order to elucidate genes and interactions involved in the template-switching (TS) pathway of DNA damage tolerance (DDT). For both projects, I applied a single bioinformatic pipeline to WGS data, which led to the identification of strong candidates for causative variants in each.Thesis (M.S.)--Tufts University, 2018.Submitted to the Dept. of Biology.Advisor: Mitch McVey.Committee: Sergei Mirkin, Erik Dopman, and Stephen Fuchs.Keywords: Molecular biology, Genetics, and Bioinformatics
Risky Business: Advising Foreign Security Forces and the need for Smart Partnership
No full textAbstract: In the post World War Two era, the United States has regularly supported advisory mission to organize, train, equip, rebuild and advise foreign security forces. Today the conventional military of the United States are continually called upon to train a wide variety of foreign security forces ranging from conventional military units to police forces. Examinations of the U.S. Security Force Assistance (SFA) campaigns since World War II illuminates the broader roles and missions that the Department of Defense, the Department of State and other U.S. government entities have placed in the support of host nation foreign security forces through training and equipping. Due to the sensitive politico-military nature of these campaigns, decision-making in and oversight of these campaigns usually resides with the President and senior policy makers of departments as well as the statutory members to the National Security Council. This dissertation examines the policy and strategy of U.S. security force assistance campaigns within a host nation. The central question o this research is what factors best explain the success and failure of U.S. SFA campaigns in support of a host nation's security forces? This study provides generalizations about how the United States provides support to the organization, training, equipping, rebuilding and advising of a foreign security force. More specifically, it examines the U.S. historical experience to find evidence of a SFA campaign's strategic effectiveness and what variables pertinent to decision making at the national level explain that effectiveness. This dissertation closes with recommendations on the policy, strategy and implementation of security force assistance campaigns. This study draws from an interdisciplinary body of literature to build a theoretical model known as smart partnership to describe past experience and prescribe future strategy development and implementation of support to security force assistance missions. This model is tested against three cases: U.S. SFA efforts in El Salvador from 1979-1989, U.S. SFA efforts in Kosovo from 1999-2009, and U.S. SFA efforts in Iraq from 2003-2011.Thesis (Ph.D.)--Tufts University, 2018.Submitted to the Dept. of Diplomacy, History, and Politics.Advisor: Richard Shultz, Jr..Committee: Antonia Chayes, and Robert Pfaltzgraff.Keyword: International relations
Trading frictions in Indian village economies.
No full textThis paper presents evidence of trading frictions in rural Indian villages. I first introduced a new seed variety to a random subset of farmers in 82 villages. I then allowed the new variety to diffuse through farmer-to-farmer trading in a random half of villages. This mode of exchange is compared with demand that was approximated by selling the same seeds directly to farmers in the other half of villages. I find that direct trading between farmers leads to substantial under-adoption when compared to door-to-door sales — suggesting that trading frictions exist and represent a barrier to technological diffusion. Caste identity explains some, but not all, of this puzzle. Specifically, farmers sharing the same surname or belonging to the same subcaste as the original seed recipients adopt at higher rates when farmers trade amongst themselves. Overall, the trading frictions in farmer-to-farmer exchange are severe enough to make door-to-door sales cost effective
Anthropometry and Clinical Assessment for research.
No full textThis presentation was given at First National Workshop in Nepal
Research and Learning USAID.
No full textThis presentation was given at First National Workshop in Nepal
Multiscale Design and Synthesis of Bioinspired Protein/Mineral Systems
No full textAbstract: Natural systems often outperform synthetic materials for their heterogeneous hierarchical architectures. These biological composites are usually comprised of soft and hard phases in complex pattern and structures, with dimension ranging from nanoscale to macroscale, although built in ambient environments from limited components. The resulting systems enable distinct integration of strength and toughness, leading to elegant structures with tissue-specific functions. For example, continuous macroscale gradients present at the osteochondral tissue interface with nano-/micro-scale patterns, reflect complex biological functions and involve changes in extracellular matrix (ECM) composition, cell types and mechanical properties. To mimic these natural gradient hierarchical architectures, this dissertation provides bioinspired mineralization strategies to create novel protein/mineral composite systems via hierarchical assembly of nano-building blocks onto polymeric templates. Silk protein-based composites, coupled with selective peptides R5 with mineralization domains, were created to mimic the soft-to-hard transition in osteochondral interfaces. The gradient composites supported continuous transition in composition and structural and mechanical properties corresponding to the spatial concentration gradient of the mineralization domains. The biocompatible and biodegradable gradient silicified silk/R5 composites promoted and regulated osteogenic and chondrogenic differentiation of human mesenchymal stem cells in an osteoinductive and chondroinductive environment in vitro, respectively, in a manner consistent with the cellularity and ECM gradients at osteochondral interfaces. In addition, natural composites are usually complex and anisotropic at the microscopic scale. Well-designed micropatterns present in native tissues and organs involve changes in ECM compositions, cell types and mechanical properties to reflect complex biological functions. However, the design and fabrication of these micropatterns in vitro to meet task-specific biomedical applications remains a challenge. In this dissertation, I also present a de novo design strategy to code bio-functional micropatterns to engineer cell alignment through integration of aqueous-peptide inkjet printing and site-specific biomineralization. Inkjet printing allows for the direct writing of macroscopic R5 peptide patterns with microscale resolution on the surface of silk hydrogels. This is combined with in situ biomineralization of the R5 peptide for site-specific growth of silica nanoparticles on the micropatterns, while avoiding the use of harsh chemicals or complex processing. The resulting mineralized micropatterned systems were used to align human mesenchymal stem cells and bovine serum albumin in vitro. In conclusion, this dissertation explored the feasibility of using silk as a template to combine selective mineralization domains to mimic the hierarchical architecture in biological systems from the molecular level to microscale and ultimately macroscale. The bioinspired multiscale design of mineral assembles on polymeric templates offers a useful approach to develop complex heterogeneous organic/inorganic composites for a wide range of applications in tissue engineering and regenerative medicine, especially osteochondral tissue engineering.Thesis (Ph.D.)--Tufts University, 2018.Submitted to the Dept. of Chemical and Biological Engineering.Advisor: David Kaplan.Committee: Gordana Vunjak-Novakovic, Qiaobing Xu, and Ayse Asatekin.Keyword: Chemical engineering