The Effects of Selected Sugars on the Rheological Properties of Rehydrated Vital Gluten

Solutions of four common sugars, sucrose, maltose, glucose, and fructose were individually mixed with rehydrated vital gluten. The mixtures were then subjected to a standard baking test and to rheological examination. In both instances the addition of sugar significantly altered stress-strain relationships. The viscosity and extensibility of all the mixtures containing sugar were greater than that of the pure gluten. This suggests that the sugars had peptized the gluten and inhibited its thermal coagulation during baking. Significant differences between the action of individual sugars could not be ascertained, however. A Maxwell model for visoelastic behavior was found to fit the rheological data quite well within experimental limits. Meaningful comparisons between experimentally measured coefficients for viscosity and shear moduli and literature values were difficult because of differences in purity and sources of the gluten. However, the measured elastic moduli were an order of magnitude greater than those reported earlier for gluten in wheat flour doughs. This was attributed to a higher purity of the test gluten and to a better testing technique than had been used heretofore

Mortality surveillance and verbal autopsy strategies: experiences, challenges and lessons learnt in Papua New Guinea.

Full notification of deaths and compilation of good quality cause of death data are core, sequential and essential components of a functional civil registration and vital statistics (CRVS) system. In collaboration with the Government of Papua New Guinea (PNG), trial mortality surveillance activities were established at sites in Alotau District in Milne Bay Province, Tambul-Nebilyer District in Western Highlands Province and Talasea District in West New Britain Province.Provincial Health Authorities trialled strategies to improve completeness of death notification and implement an automated verbal autopsy methodology, including use of different notification agents and paper or mobile phone methods. Completeness of death notification improved from virtually 0% to 20% in Talasea, 25% and 75% using mobile phone and paper notification strategies, respectively, in Alotau, and 69% in Tambul-Nebilyer. We discuss the challenges and lessons learnt with implementing these activities in PNG, including logistical considerations and incentives.Our experience indicates that strategies to maximise completeness of notification should be tailored to the local context, which in PNG includes significant geographical, cultural and political diversity. We report that health workers have great potential to improve the CRVS programme in PNG through managing the collection of notification and verbal autopsy data. In light of our findings, and in consultation with the main government CRVS stakeholders and the National CRVS Committee, we make recommendations regarding the requirements at each level of the health system to optimise mortality surveillance in order to generate the essential health intelligence required for policy and planning

Bile-salt stimulated lipase polymorphisms do not associate with HCV susceptibility

Bile-salt stimulate lipase (BSSL) is a glycoprotein found in human milk and blood that can potently bind DC-SIGN. The BSSL gene is highly polymorphic with a variant number of O-linked glycosylated 11 amino acid repeats at the C-terminus of the protein, encoded in exon 11 of the gene. It has been shown that certain BSSL genotypes associate with decreased HIV-1 transmission in vitro and decreased HIV-1 disease progression. The protein forms dimers and individuals possessing one high (typically 14–21) and one low (typically 7–11) number of repeat domains has been shown to have stronger binding of BSSL to DC-SIGN and HIV-1 inhibitory activity in vitro. Since we previously demonstrated that SNPs within the DC-SIGN gene can associate with risk of HCV sexual transmission and which can be linked to diminished DC-SIGN gene expression we aimed to identify whether BSSL polymorphisms associated similarly through differential binding to DC-SIGN. DNA was isolated from the HIV-1 infected MSM cohort (MOSAIC) composed of HCV multiple exposed uninfected (MEU) (N = 30) and multiple exposed HCV infected (MEI) (N = 32) individuals and from the Amsterdam cohort studies (ACS) intravenous drug using (IDU) cohort (22 MEI and 40 MEU). The numbers of repeats in exon 11 were determined by PCR with repeat distributions compared between MEI and MEU. No statistical significant difference in the copy number of exon 11 repeats, or combinations of, in the BSSL gene was observed when comparing HCV infected MEI with MEU, thus the exon 11 repeat copy number in the BSSL gene does not affect HCV susceptibility

Integrating Sequencing Technologies in Personal Genomics: Optimal Low Cost Reconstruction of Structural Variants

The goal of human genome re-sequencing is obtaining an accurate assembly of an individual's genome. Recently, there has been great excitement in the development of many technologies for this (e.g. medium and short read sequencing from companies such as 454 and SOLiD, and high-density oligo-arrays from Affymetrix and NimbelGen), with even more expected to appear. The costs and sensitivities of these technologies differ considerably from each other. As an important goal of personal genomics is to reduce the cost of re-sequencing to an affordable point, it is worthwhile to consider optimally integrating technologies. Here, we build a simulation toolbox that will help us optimally combine different technologies for genome re-sequencing, especially in reconstructing large structural variants (SVs). SV reconstruction is considered the most challenging step in human genome re-sequencing. (It is sometimes even harder than de novo assembly of small genomes because of the duplications and repetitive sequences in the human genome.) To this end, we formulate canonical problems that are representative of issues in reconstruction and are of small enough scale to be computationally tractable and simulatable. Using semi-realistic simulations, we show how we can combine different technologies to optimally solve the assembly at low cost. With mapability maps, our simulations efficiently handle the inhomogeneous repeat-containing structure of the human genome and the computational complexity of practical assembly algorithms. They quantitatively show how combining different read lengths is more cost-effective than using one length, how an optimal mixed sequencing strategy for reconstructing large novel SVs usually also gives accurate detection of SNPs/indels, how paired-end reads can improve reconstruction efficiency, and how adding in arrays is more efficient than just sequencing for disentangling some complex SVs. Our strategy should facilitate the sequencing of human genomes at maximum accuracy and low cost

DC-SIGN Polymorphisms Associated with Risk of Hepatitis C Virus Infection Among Men who Have Sex with Men but not Among Injecting Drug Users

We aimed to identify whether genetic polymorphisms within L-SIGN or DC-SIGN correlate with HCV susceptibility. An MSM and an IDU cohort of HCV cases and multiple-exposed uninfected controls were genotyped for numerous L-SIGN and DC-SIGN polymorphisms. DC-SIGN SNPs -139, -871 and -939 correlate with HCV acquisition in the MSM cohort only. When the same SNPs were introduced into a transcription activity assay they demonstrated a reduction in expression with predicted alteration in binding of transcription factors. DC-SIGN promoter SNPs correlate with risk of HCV acquisition via sexual but not IDU exposure, likely through modulation of mRNA expression levels

Asymmetric collimation : dosimetric characteristics, treatment planning algorithm, and clinical applications

Asymmetric collimation of photon beams produces non-trivial alterations in absolute output, depth dose and beam profile. The full potential of asymmetric collimation can only be realized with a proper treatment planning algorithm specific for asymmetric collimation. In this thesis the dosimetric characteristics of asymmetric fields are investigated and a new computation method for the dosimetry of asymmetric fields is described and implemented into an existing treatment planning algorithm. Based on this asymmetric field treatment planning algorithm, the clinical use of asymmetric fields in cancer treatment is investigated, and new treatment techniques for conformal therapy are developed. Dose calculation is verified with thermoluminescent dosimeters in a body phantom. An asymmetric field is referred to as an off-set radiation field whereby the central axis of the radiation field does not coincide with the collimator axis as the opposite pair of collimators no longer are equidistant from the collimator axis. Here, the corresponding symmetric field is a radiation field centered at the collimator axis with the opposite pair of collimators set equidistant from the collimator axis and to the largest asymmetric collimator setting. Usually the dose distribution in an asymmetric field is represented by some form of beam modeling. In this thesis, an analytical approach is proposed to account for the dose reduction when a corresponding symmetric field is collimated asymmetrically to a smaller asymmetric field. This is represented by a correction factor that uses the ratio of the equivalent field dose contributions between the asymmetric and symmetric fields. The same equation used in the expression of the correction factor can be used for a wide range of asymmetric field sizes, photon energies and linear accelerators. This correction factor will account for the reduction in scatter contributions within an asymmetric field, resulting in the dose profile of an asymmetric field resembling that of a wedged field. The output factors of some linear accelerators are dependent on the collimator settings and whether the upper or lower collimators are used to set the narrower dimension of a radiation field. In addition to this collimator exchange effect for symmetric fields, asymmetric fields are also found to exhibit some asymmetric collimator backscatter effect. The proposed correction factor is extended to account for these effects. A set of correction factors determined semi-empirically to account for the dose reduction in the penumbral region and outside the radiated field is established. Since these correction factors rely only on the output factors and the tissue maximum ratios, they can easily be implemented into an existing treatment planning system. There is no need to store either additional sets of asymmetric field profiles or databases for the implementation of these correction factors into an existing in-house treatment planning system. With this asymmetric field algorithm, the computation time is found to be 20 times faster than a commercial system. This computation method can also be generalized to the dose representation of a two-fold asymmetric field whereby both the field width and length are set asymmetrically, and the calculations are not limited to points lying on one of the principal planes. The dosimetric consequences of asymmetric fields on the dose delivery in clinical situations are investigated. Examples of the clinical use of asymmetric fields are given and the potential use of asymmetric fields in conformal therapy is demonstrated. An alternative head and neck conformal therapy is described, and the treatment plan is compared to the conventional technique. The dose distributions calculated for the standard and alternative techniques are confirmed with thermoluminescent dosimeters in a body phantom at selected dose points.Science, Faculty ofPhysics and Astronomy, Department ofGraduat

Whole blood donor deferral analysis at a center in Western India

<b>Introduction:</b> Deferrals lead to loss of precious whole blood donors (WBD) and blood units available for transfusion purposes. Knowledge of rate and causes of donor deferral can guide the recruitment strategy for WBD. <b>Aim:</b> To find the incidence and causes of deferral in Indian WBD and apply relevant findings to modify recruitment strategy for blood donors. <b>Materials and Methods:</b> Data for WBD presenting for donation in a blood center and outdoor camps over one and half year were analyzed retrospectively. National guidelines were used for selection and deferral of WBD. <b>Result:</b> 736 (11.6&#x0025;) WBD were deferred out of 6357 presenting for donation during the study period. Most (69.8&#x0025;) of the donors were deferred on physical examination and hemoglobin (Hb) testing. Most common reasons for deferral were low Hb (55.8&#x0025;), abnormal blood pressure (11.1&#x0025;), medication (6.9&#x0025;) and underweight donors (2.9&#x0025;). Significantly more volunteers were deferred than relative donors (13.97&#x0025; vs 5.80&#x0025;; <i>P</i>&lt;0.000). Females were found to have higher deferral rate than males (53.5&#x0025; vs 6.9&#x0025;; P=0.000) and higher odds ratio for deferral (15.4). Donors older than 40 years of age had significantly higher chance of being deferred (<i>P</i>&lt;0.05). <b>Discussion and Conclusion:</b> It is important to determine the rate and causes of WBD deferral to guide the recruitment and retention efforts at local, regional, and national level