Studies on the processing of New Zealand grapefruit juice : a thesis presented in partial fulfilment of the requirements for the degree of Master of Technology in Food Technology at Massey University

The likely origin of the New Zealand grapefruit (NZGF) is discussed and present and future trends in its production and utilisation presented. Early and late season samples of NZGF juice were analysed for the presence of the enzymes pectinesterase, polygalacturonase and ascorbic acid oxidase, no trace of the latter two being found. Samples of juice from NZGF harvested at regular intervals from July until December 1973 were analysed for yield, total soluble solids, titratable acidity, pH, pectinesterase activity, and ascorbic acid content. The average yield of juice obtained (35.6% w/w) was significantly lower than that reported from overseas for true grapefruit. The level of total soluble solids remained fairly constant in the range 12.0 to 12.6%, while the pH of the juice increased throughout the season from 2.95 to 3.40. The titratable acidity was within the range 1.0 to 2.0 grams of citric acid per 100 ml of juice, while the Brix : acid ratio varied from 5.02 to 10.03. The level of pectinesterase in the juice (which increased as the season progressed) was comparable with that found in overseas citrus juices, while the level of ascorbic acid in the juice declined over the season from 32.4 to 23.2 mg/100 ml, in agreement with overseas trends. With the exception of yield, the compositional characteristics of NZGP juice reported here do not differ markedly from overseas grapefruit juices. The important role which pectinesterase plays in the destabilisation of citrus juice cloud is outlined and possible methods for inactivating the enzyme are described. As the application of heat is the only method in commercial use, factors affecting and methods for studying the thermal inactivation of enzymes are discussed. As the major objection to most of these methods is the way in which the heating and cooling lags are evaluated, a new method which adequately describes these thermal lags has been developed for determining the thermal resistance of pectinesterase in NZGP juice. A digital computer was programmed to determine (using a trial and error technique) the constants in two expressions which relate the equivalent effect of unsteady state heating and cooling of NZGF juice to the inactivation of pectinesterase. One expression assumed that the rate of inactivation was exponentially related to temperature; in this case the constant was the z value. The other expression assumed that the rate was related to temperature according to the Arrhenius equation, in which case the constant was the activation energy. The two constants were evaluated for both low and high pH juice. It was found that the latter expression using the Arrhenius equation described the change in rate of inactivation with temperature more adequately than the former expression. From these expressions the times required at different temperatures to inactivate pectinesterase in NZGP juice of varying pH were calculated. The application of these results to the industrial processing of NZGP juice is discussed

Emission within a Damped Lyman Alpha Absorption Trough: the Complex Sight Line Towards Q2059-360

We present new spectroscopic observations of the quasar Q2059-360, confirming the existence of an emission feature within the Damped Lyman Alpha (DLA) absorption trough. By observing also at slit positions offset from the quasar, we show that the emission is spatially extended by at least a few arcseconds, and hence confirm that the feature seen must be due to emission rather than unusual absorption characteristics. We find that the DLA trough is very close in redshift to the broad Lyman~$\alpha$ emission line of the QSO, with the result that the DLA absorption removes much of the peak region of that line. Despite the similarity of the redshifts of the DLA and the QSO, the lack of high-ionization lines of the DLA system and the unresolved widths of the corresponding metal lines indicate that the DLA cloud is not an associated system. The emission feature has a large velocity offset of +490 km/s with respect to the DLA system, and is resolved in velocity, comprising two components with a separation of ~ 300 km/s. We consider three possibilities: (1) Both emission and absorption occur within an object similar to the high redshift Lyman-break galaxies; (2) The emission feature arises from an object distinct from both the DLA absorber and the QSO, perhaps a young star-forming galaxy or a proto-galactic clump. It could be associated with the DLA absorber and perhaps the QSO in a compact group or cluster; (3) The redshifts are such that the emission feature could be due to Narrow Line Region filaments of the QSO, if the DLA absorption covers a sufficiently small angular size to allow the filaments to be seen beyond the edge of the DLA cloud.Comment: 10 pages, 6 figures. Accepted for publication in MNRA

Absenteeism and Labour Turnover in Selected Ontario Industries

Les employeurs considèrent l'absentéisme et le roulement de la main-d'oeuvre comme un des plus sérieux problèmes des relations du travail qui puissent affecter les entreprises en Ontario. C'est ce qu'indique une enquête récente du ministère du travail de cette province.Bien qu'elles soient conscientes du caractère grave de ces problèmes, bien peu d'entreprises compilent actuellement des statistiques sur l'absentéisme et le roulement de la main-d' oeuvre. Moins de vingt-cinq pour cent d'entre ellesont cherché à en découvrir les causes profondes et moins de dix pour cent ont pris des mesures pour les circonscrire.Le premier objectif de cette enquête était d'accumuler des données sur l'ampleur de l'absentéisme et du roulement de la main-d'oeuvre grâce auxquelles les entreprises pouvaient individuellement échanger leur expérience sur ces deux problèmes importants. L'étude fournit aussi des renseignements sur l'étendue, la nature et l'impact relatifs de ces « problèmes humains » dans l'industrie.Se fondant sur les données recueillies, il est possible de dégager un certain nombre d'observations générales. En premier lieu, étant donné leur seule ampleur et la perception que les employeurs ont de leur gravité, il est évident que l'absentéisme et le roulement de la main-d'oeuvre sont des problèmes sérieux et passablement hors de contrôle pour une proportion significative des répondants.En second lieu, parce que cette situation est courante dans toutes les régions et toutes les industries, la nature des problèmes diffère considérablement, en particulier d'une industrie à l'autre. Par exemple, une bonne part de l'activité économique reposant sur les industries primaires s'effectue dans des régions isolées et est sujette à des fluctuations saisonnières et cycliques considérables. Par contre, la plupart des industries de transformation et les services se trouvent dans les districts urbains et ils sont moins touchés par ces deux facteurs.Finalement, tandis qu'il est évident que ces problèmes tendent à devenir de plus en plus marqués dans certaines régions de la province et dans certaines industries, le grand écart des taux d'absentéisme et de virement de la main-d'oeuvre parmi les établissements d'une région donnée ou d'un groupe d'industries semble indiquer qu'une bonne part des difficultés se posent aux établissements considérés individuellement.Cette constatation présente un état d'inquiétude particulier lorsqu'on l'oppose à la perception qu'ont les employeurs des causes profondes et des solutions qu'ils proposent à l'absentéisme et au roulement de la main-d'oeuvre. Alors qu'un certain nombre d'entreprises se rendent compte que les conditions d'emploi, les taux de salaires, les types de direction etc. favorisent l'absentéisme et le roulement de la main-d'oeuvre, beaucoup d'autres considèrent qu'ils sont la résultante de facteurs qui leur échappent, y inclus un manque d'éthique professionnelle et les problèmes personnels de leurs employés. Cette attitude se traduit par le manque d'action concrète pour les circonscrire et les résoudre.Même si les cadres de cette enquête ne vont pas jusqu'à démontrer jusqu'à quel point ce problème relatif aux ressources humaines peut être corrigé par les employeurs, la diminution des taux d'absentéisme et de roulement de la main-d'oeuvre obtenue par les entreprises qui ont pris des mesures pour améliorer les conditions de travail et le climat de l'établissement indiquent que beaucoup de progrès pourrait s'accomplir si les employeurs apportaient plus d'attention et plus de soin à l'administration des ressources humaines.The primary objective of this survey is therefore to collect enough data to in order that comparisons of absenteeism and labour turnover can be made within various regions and industries in Ontario. The study also provides general information on the extent, nature and relative importance of various human problems

Le conflit fédéral-provincial au Canada : raisons et solutions

The author seeks to identify why Canada, as a country, has not faired out well in recent years and finds that the source of our problems lie deep in the mechanisms of federal-provincial relations. Four factors make these relations difficult : the differences flowing from distinct ethnic and linguistic origins, inadequacy of various institutions of our central government, the unclear and uneasy balance of federal-provincial powers and the extent of activity by our governments that are pressing at the outer limits of their jurisdictions

Does Border Enforcement Protect U.S. Workers from Illegal Immigration?

In this paper, we examine the impact of government enforcement of the U.S.-Mexican border on wages in the border regions of the United States and Mexico. The U.S. Border Patrol polices U.S. boundaries, seeking to apprehend any individual attempting to enter the United States illegally. These efforts are concentrated on the Mexican border, as most illegal immigrants embark from a Mexican border city and choose a U.S. border state as their final destination. We examine labor markets in southern California, southwestern Texas, and Mexican cities on the U.S.-Mexico border. For each region, we have high-frequency time-series data on wages and on the number of person hours that the U.S. Border Patrol spends policing border areas. For a range of empirical specifications and definitions of regional labor markets, we find little impact of border enforcement on wages in U.S. border cities and a moderate negative impact of border enforcement on wages in Mexican border cities. These findings are consistent with two hypothesis: (1) border enforcement has a minimal impact on illegal immigration, or (2) immigration from Mexico has a minimal impact on wages in U.S. border cities.

Simulating a dual beam combiner at SUSI for narrow-angle astrometry

The Sydney University Stellar Interferometer (SUSI) has two beam combiners, i.e. the Precision Astronomical Visible Observations (PAVO) and the Microarcsecond University of Sydney Companion Astrometry (MUSCA). The primary beam combiner, PAVO, can be operated independently and is typically used to measure properties of binary stars of less than 50 milliarc- sec (mas) separation and the angular diameters of single stars. On the other hand, MUSCA was recently installed and must be used in tandem with the for- mer. It is dedicated for microarcsecond precision narrow-angle astrometry of close binary stars. The performance evaluation and development of the data reduction pipeline for the new setup was assisted by an in-house computer simulation tool developed for this and related purposes. This paper describes the framework of the simulation tool, simulations carried out to evaluate the performance of each beam combiner and the expected astrometric precision of the dual beam combiner setup, both at SUSI and possible future sites.Comment: 28 pages, 23 figures, accepted for publication in Experimental Astronomy. The final publication is available at http://link.springer.co

A low cost scheme for high precision dual-wavelength laser metrology

A novel method capable of delivering relative optical path length metrology with nanometer precision is demonstrated. Unlike conventional dual-wavelength metrology which employs heterodyne detection, the method developed in this work utilizes direct detection of interference fringes of two He-Ne lasers as well as a less precise stepper motor open-loop position control system to perform its measurement. Although the method may be applicable to a variety of circumstances, the specific application where this metrology is essential is in an astrometric optical long baseline stellar interferometer dedicated to precise measurement of stellar positions. In our example application of this metrology to a narrow-angle astrometric interferometer, measurement of nanometer precision could be achieved without frequency-stabilized lasers although the use of such lasers would extend the range of optical path length the metrology can accurately measure. Implementation of the method requires very little additional optics or electronics, thus minimizing cost and effort of implementation. Furthermore, the optical path traversed by the metrology lasers is identical with that of the starlight or science beams, even down to using the same photodetectors, thereby minimizing the non-common-path between metrology and science channels.Comment: 17 pages, 4 figures, accepted for publication in Applied Optic

The development of a geriatric postgraduate education assessment instrument using a modified Delphi procedure

There is currently wide variation in the structure and content of higher medical training in geriatric medicine across Europe and no common framework within which existing efforts can be compared. We set out to develop an audit tool to compare training between countries. An initial review of indexed and grey literature was used to develop an audit tool which was used as the basis of an Internet-based modified Delphi process incorporating the views of 14 expert geriatricians from across Europe. Items in the audit tool were included or excluded when supported by ≥75% or <50% of respondents, respectively. Items supported by 50–74% of respondents were carried forward with additional suggestions and modifications included following Round 1. Thirteen experts representing 12 countries responded to both rounds. 40/45 items were supported at Round 1. Five items were carried forward. A further 13 elements were introduced for consideration at Round 2. Consensus was gained after the second round. The final tool describes 52 items across four domains: general considerations, topics referring to knowledge in patient care, different roles that should be considered in medical training and topics regarding assessment. The resulting tool can be used as a basis for comparing higher medical training programmes in geriatric medicine between countries. Individual countries can use this to audit current practice. At an European Union level, the insights gained through such audit will form the basis of future work to develop an agreed postgraduate curriculum in the specialty