Determination of the distribution of water droplet sizes in butter and margarine using pulsed field gradient-NMR and confocal scanning laser microscopy : this thesis was presented in partial fulfillment of the requirements for [the] degree of Master of Science in Chemistry at Massey University

PFG-NMR has been used to determine the distribution of water droplets in emulsions. Especially, it has been used to measure the samples with high optical dense systems and highly viscous systems Butters and Margarines). To refine the method, the optimum measuring condition was investigated. It included delay time (Δ) between the field gradient pulses, τ null (τ0), gradient strength (G), water self-diffusion coefficients (D) and sampling techniques. Under the optimum conditions the water droplet size distributions of commercial butters, experimental butters and margarines were measured. Experimental results showed that PFG-NMR is an accurate, fast method to determine the water droplet size distributions of the butters and margarines. Also, it is can be used to investigate the properties of dispersed phase in emulsions. Especially, the method is suitable not only in the laboratory but also in the factory environment. The method was able to distinguish different distributions in butters of the same water content but with different manufacturing techniques. Differences in the distributions of water droplets were also obtained when comparing butters made by the same manufacturing technique but with different water contents. To confirm the results from PFG-NMR, confocal scanning laser microscopy (CSLM) was chosen to determine the droplet size distributions and the moisture contents of samples. Comparison between PFG-NMR and CSLM shows limitations in the latter techniques and its uses are limited

Construction of a novel fungal gus expression plasmid, and its evaluation in Aspergillus nidulans : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science in Genetics at Massey University

A GUS expression plasmid, pFunGus, was constructed containing a multi-cloning site for the insertion of gene regulatory elements, to be used in fungal reporter gene studies. A derivative of pFunGus (pFG-gpd) was constructed by the insertion of the gpdA promoter (glyceradehyde-3-phosphatc dehydrogenase) into the multi-cloning site of pFunGus for the assessment of the plasmid's transformation and expression properties in Aspergillus niduans. The correct construction of pFunGus and pFG-gpd was verified by analytical restriction digests and by its property of GUS expression in A. nidulans. The plasmid was integrated into the A. nidulans genome via cotransformation with the phleomycin resistance plasmid, pAN8-l. Transformation frequencies of between 3 and 250 transformants per µg of pAN8-l DNA were obtained. Initial screening for cotransformation yielded no pFG-gpd transformants. Attempts to improve cotransformation frequencies by optimisation of cotransformation conditions were unsuccessful. However, large scale screenings of transformants lead to cotransformants being isolated at a very low cotransformation frequency. Approximately 0.45% of pAN8-l transformants possessed the GUS phenotype. The eight pFG-gpd transformants obtained were analysed by Southern hybridisation. Six out of the eight transformants had a single copy integration. Of the remaining two transformants, one had three copies integrated at separate locations, one of which was disrupted, and the other had four copies integrated as tandem repeats, one of which was disrupted. All the transforming DNA appeared to be integrated ectopically. The physiology of the transformants was assessed by dry weight increase, colony extension and total protein content. These showed that the transformants biology was not significantly compromised by the transforming DNA. Finally, high levels of GUS expression were observed in all pFG-gpd transformants and the GUS expression per copy of the GUS expression cassette integrated into the genome was constant. These results showed that the transformed gene copy number determined the levels of gene activity rather than the position of integration in the genome. Overall these results demonstrate the potential application of the versatile GUS expression plasmid, pFunGus for reporter gene studies in filamentous fungi

Using NMR to Measure Fractal Dimensions

A comment is made on the recent PFG NMR measurements by Stallmach, et al. on water-saturated sands [Phys. Rev. Lett. 88, 105505 (2002)]. It is pointed out that the usual law for the time-dependent diffusion coefficient D(t) used by these authors is not valid for a fractal surface. It is shown that (1-D(t)/D0) \~ t^[(3-Ds)/2] at short times for a surface of fractal dimension Ds, where D0 is the bulk diffusion coefficient. Preliminary PFG NMR data on water saturated limestone and plastic beads are presented to illustrate this analysis.Comment: 1 page, 1 figur

Effects of orbital occupancies on the neutrinoless beta-beta matrix element of 76Ge

In this work we use the recently measured neutron occupancies in the 76Ge and 76Se nuclei as a guideline to define the neutron quasiparticle states in the 1p0f0g shell. We define the proton quasiparticles by inspecting the odd-mass nuclei adjacent to 76Ge and 76Se. We insert the resulting quasiparticles in a proton-neutron quasiparticle random-phase approximation (pnQRPA) calculation of the nuclear matrix element of the neutrinoless double beta (0-nu-beta-beta) decay of 76Ge. A realistic model space and effective microscopic two-nucleon interactions are used. We include the nucleon-nucleon short-range correlations and other relevant corrections at the nucleon level. It is found that the resulting 0-nu-beta-beta matrix element is smaller than in the previous pnQRPA calculations, and closer to the recently reported shell-model results.Comment: To appear in Physics Letters

Combinations of LL-functions and Their Non-coincident Zeros for σ>1\sigma>1

The purpose of this note is to build upon work of Booker--Thorne and Righetti concerning zeros of algebraic combinations of $L$-functions. Namely, we show that two generic combinations of functions from a wide class of Euler products have non-coincident zeros in the half-plane $\sigma>1$.Comment: 6 page

Self-diffusion of polymers in cartilage as studied by pulsed field gradient NMR

Pulsed field gradient (PFG) nuclear magnetic resonance (NMR) was used to investigate the self-diffusion behaviour of polymers in cartilage. Polyethylene glycol and dextran with different molecular weights and in different concentrations were used as model compounds to mimic the diffusion behaviour of metabolites of cartilage. The polymer self-diffusion depends extremely on the observation time: The short-time self-diffusion coefficients (diffusion time Delta approximately 15 ms) are subjected to a rather non-specific obstruction effect that depends mainly on the molecular weights of the applied polymers as well as on the water content of the cartilage. The observed self-diffusion coefficients decrease with increasing molecular weights of the polymers and with a decreasing water content of the cartilage. In contrast, the long-time self-diffusion coefficients of the polymers in cartilage (diffusion time Delta approximately 600 ms) reflect the structural properties of the tissue. Measurements at different water contents, different molecular weights of the polymers and varying observation times suggest that primarily the collagenous network of cartilage but also the entanglements of the polymer chains themselves are responsible for the observed restricted diffusion. Additionally, anomalous restricted diffusion was shown to occur already in concentrated polymer solutions

Using action understanding to understand the left inferior parietal cortex in the human brain

Published in final edited form as: Brain Res. 2014 September 25; 1582: 64–76. doi:10.1016/j.brainres.2014.07.035.Humans have a sophisticated knowledge of the actions that can be performed with objects. In an fMRI study we tried to establish whether this depends on areas that are homologous with the inferior parietal cortex (area PFG) in macaque monkeys. Cells have been described in area PFG that discharge differentially depending upon whether the observer sees an object being brought to the mouth or put in a container. In our study the observers saw videos in which the use of different objects was demonstrated in pantomime; and after viewing the videos, the subject had to pick the object that was appropriate to the pantomime. We found a cluster of activated voxels in parietal areas PFop and PFt and this cluster was greater in the left hemisphere than in the right. We suggest a mechanism that could account for this asymmetry, relate our results to handedness and suggest that they shed light on the human syndrome of apraxia. Finally, we suggest that during the evolution of the hominids, this same pantomime mechanism could have been used to ‘name’ or request objects.We thank Steve Wise for very detailed comments on a draft of this paper. We thank Rogier Mars for help with identifying the areas that were activated in parietal cortex and for comments on a draft of this paper. Finally, we thank Michael Nahhas for help with the imaging figures. This work was supported in part by the NIH grant RO1NS064100 to LMV. (RO1NS064100 - NIH)Accepted manuscrip