22,209 research outputs found
Flower and fruit development in processing tomatoes : a thesis presented in partial fulfilment of the requirements for the degree of Master of Horticultural Science in Vegetable Production at Massey University
Processing tomato crops are mechanically harvested from a single destructive harvest. The timing of this harvest to coincide with the maximum yield of factory grade fruit is of considerable importance to the efficiency of the field operation. There is a lack of information regarding where the factory grade fruit is produced on the plant and for how long the yield of factory grade fruit is maintained at its maximum level in the field. Two experiments were carried out in the Manawatu using the processing cultivars Castlehye 1204 Improved and UC 82B. The first experiment determined the time of flowering of all the flowers on the plant, the trusses in which these flowers were to be found and the position of these trusses on the plant. 132 days after planting all the plants were harvested and the number and position on the plant of the flowers which set fruit was determined. A normal distribution was found to satisfactorily describe the relationship between the number of flowers reaching anthesis and time. Plants on average carried up to 37 trusses. 65% of the yield was carried on the first 10 trusses to flower with 95% of the yield carried on the first 20 trusses to flower. The efficiency of trusses in producing fruit varied from 66% with the earlier flowering trusses down to negligible levels. Plants had up to 8 main order laterals and together with their attached sub laterals each carried from 4-5 trusses. The efficiency of flowering decreased with the position of the truss up the lateral. It was suggested that the competition between trusses for assimilates is far more important within laterals than between laterals. These results have implications for both crop management and plant breeding programmes. In the second experiment 9 successional destructive harvests were carried out commencing at the first sign of coloured fruit. Ethryl was not applied to the crop. The yield of red and factory grade fruit was found to peak sharply over time. The normal distribution curve was found to satisfactorily describe the relationship between time and the yield of both red and factory grade fruit and fruit numbers of these grades of fruit. Harvesting one week earlier or one week later than the optimum harvest date resulted in a loss of factory grade fruit of from 10-15 tonnes per hectare. The major cause for this rapid fall in yield from the optimum was due to an increase in the yield of red rotten fruit. In fact over half of the total number of fruit had rotted by 136 days after planting. This included a significant number of green fruit. The magnitude of this loss was only apparent because successional harvests were carried out. The total yield of fruit (all grades) was maintained over a considerable period as the loss in fruit numbers was balanced by the increase in mean fruit weight of the crop. The mean fruit weight of fruit did not increase once they had coloured. The percent soluble solids of red fruit decreased the week following any significant amount of rainfall. In the light of this research the effect of ethryl on the maturity characteristics of processing tomato crops needs to be re-examined by the use of successional harvests. Reliable techniques also need to be developed to predict the time of optimum harvest as these results suggest that it is much shorter than is commonly thought. The importance of fruit rots in reducing yields and thus effecting the length of the optimum harvest period is also apparent and is another area of research which requires further study. In the first experiment, the Normal Distribution Curve was found to describe the frequency of flower anthesis versus time relationship in two processing tomato cultivars; Castlehye 1204 Improved and UC 82B. Early fruit setting flowers acted as a strong sink as 90% of the final yield was carried on the first 18 trusses. Yield contributing trusses followed a pattern of increasing distance from the root system the later they flowered. Competition for photosynthate was mainly within laterals but also there was some between lateral competition. Flower trusses exhibited decreasing efficiencies in producing red fruit the later first flower anthesis occurred on the flower truss. In the second experiment, the yield of Factory Grade tomato fruit from the same two processing tomato cultivars peaked sharply over time. Harvesting one week earlier or later than the optimum harvest date resulted in a Factory Grade yield loss of up to 10-15 t ha-1for both cultivars.
The Normal Distribution Curve was found to describe the relationship between Factory Grade fruit weight and number over time for both cultivars. Both red and coloured fruit weight were also found to follow the Normal Distribution. Over half of the total number of fruit rotted by 136 days after planting. Percentage Soluble Solids of red fruit decreased as rainfall increased in the week preceding harvest, with the converse also shown to apply
Finite size corrections in random matrix theory and Odlyzko's data set for the Riemann zeros
Odlyzko has computed a data set listing more than successive Riemann
zeros, starting at a zero number beyond . The data set relates to
random matrix theory since, according to the Montgomery-Odlyzko law, the
statistical properties of the large Riemann zeros agree with the statistical
properties of the eigenvalues of large random Hermitian matrices. Moreover,
Keating and Snaith, and then Bogomolny and collaborators, have used random unitary matrices to analyse deviations from this law. We contribute
to this line of study in two ways. First, we point out that a natural process
to apply to the data set is to thin it by deleting each member independently
with some specified probability, and we proceed to compute empirical two-point
correlation functions and nearest neighbour spacings in this setting. Second,
we show how to characterise the order correction term to the spacing
distribution for random unitary matrices in terms of a second order
differential equation with coefficients that are Painlev\'e transcendents, and
where the thinning parameter appears only in the boundary condition. This
equation can be solved numerically using a power series method. Comparison with
the Riemann zero data shows accurate agreement.Comment: 22 pages, 10 figures, Version 2 added some new references in
bibliography, Version 3 corrected the scaling on the spacing distribution and
some typo
Earth's middle age
This research was funded through Natural Environment Research Council (grant NE/J021822/1) and the APC was paid through the RCUK OA block grant.Earth's middle age, extending from 1.7 to 0.75 Ga, was characterized by environmental, evolutionary, and lithospheric stability that contrasts with the dramatic changes in preceding and succeeding eras. The period is marked by a paucity of preserved passive margins, an absence of a significant Sr anomaly in the paleoseawater record and in the εHf(t) in detrital zircon, a lack of orogenic gold and volcanic-hosted massive sulfide deposits, and an absence of glacial deposits and iron formations. In contrast, anorthosites and kindred bodies are well developed and major pulses of Mo and Cu mineralization, including the world's largest examples of these deposits, are features of this period. These trends are attributed to a relatively stable continental assemblage that was initiated during assembly of the Nuna supercontinent by ca. 1.7 Ga and continued until breakup of its closely related successor, Rodinia, ca. 0.75 Ga. The overall low abundance of passive margins is consistent with a stable continental configuration, which also provided a framework for environmental and evolutionary stability. A series of convergent margin accretionary orogens developed along the edge of the supercontinent. Abundant anorthosites and related rocks developed inboard of the plate margin. Their temporal distribution appears to link with the secular cooling of the mantle, at which time the overlying continental lithosphere was strong enough to be thickened and to support the emplacement of large plutons into the crust, yet the underlying mantle was still warm enough to result in widespread melting of the lower thickened crust.Publisher PDFPeer reviewe
Temporal relations between mineral deposits and global tectonic cycles
Natural Environment Research Council (grant NE/J021822/1) supported this research.Mineral deposits are heterogeneously distributed in both space and time, with variations reflecting tectonic setting, evolving environmental conditions, as in the atmosphere and hydrosphere, and secular changes in the Earth’s thermal history. The distribution of deposit types whose settings are tied to plate margin processes (e.g. orogenic gold, volcanic-hosted massive sulphide, Mississippi valley type Pb–Zn deposits) correlates well with the supercontinent cycle, whereas deposits related to intra-cratonic settings and mantle-driven igneous events, such as Ni–Cu–PGE deposits, lack a clear association. The episodic distribution of deposits tied to the supercontinent cycle is accentuated by selective preservation and biasing of rock units and events during supercontinent assembly, a process that encases the deposit within the assembled supercontinent and isolates it from subsequent removal and recycling at plate margins.Publisher PD
A music index of periodicals for the last six months of 1948.
Thesis (M.M.)--Boston Universit
Differentiability of quadratic BSDEs generated by continuous martingales
In this paper we consider a class of BSDEs with drivers of quadratic growth,
on a stochastic basis generated by continuous local martingales. We first
derive the Markov property of a forward--backward system (FBSDE) if the
generating martingale is a strong Markov process. Then we establish the
differentiability of a FBSDE with respect to the initial value of its forward
component. This enables us to obtain the main result of this article, namely a
representation formula for the control component of its solution. The latter is
relevant in the context of securitization of random liabilities arising from
exogenous risk, which are optimally hedged by investment in a given financial
market with respect to exponential preferences. In a purely stochastic
formulation, the control process of the backward component of the FBSDE steers
the system into the random liability and describes its optimal derivative hedge
by investment in the capital market, the dynamics of which is given by the
forward component.Comment: Published in at http://dx.doi.org/10.1214/11-AAP769 the Annals of
Applied Probability (http://www.imstat.org/aap/) by the Institute of
Mathematical Statistics (http://www.imstat.org
The social context of school playground games: Sex and ethnic differences, and changes over time after entry to junior school
This short term longitudinal study examined activities at recess and peer relations. Interest was in changes over the school year, and the sex and ethnic mix of groups. Data came from systematic observations of 129 pupils (61 boys and 68 girls) aged 7-8 years. Results showed that peer interaction dominated recess. Ball games increased over the year, and chasing games decreased. Aggression was most common during vigorous play and conversation, but not ball games. Cleavage in boys' and girls' play and activity was common but not inevitable. Mixed sex play was not supported by particular game types. Boys’ game networks were larger than those of girls but there were no sex differences in active networks. There was little ethnic group segregation on playgrounds, and games became more integrated with time. Results indicate that playground activities can have a positive role in social relations between different ethnic groups
Understanding the differential benefits of training for the unemployed
[Abstract]: This study examined the connection between background variables (such as length of unemployment and number of previous training courses), contextual variables (perceptions of training climate), dispositional variables (positive affect and negative affect), and psychological outcomes for unemployed trainees who attended either a five week occupational skills training program (control group) or the same five week program with an additional two day intervention before the start of the program (treatment group). The trainees in both the treatment and control conditions were found to reduce their levels of psychological distress over the course of a five-week training program. Trainees in the treatment condition who started with the lowest levels of general self-efficacy and the highest levels of psychological distress showed the greatest improvements at time 2 (T2). The measures of length of unemployment, number of previous training courses, and the perceptions of the training climate (with one exception) did not account for any unique variance in either of the well-being measures at time 3 (T3). Positive and negative affect (PA and NA respectively) accounted for 30% of the variance in initial levels of general self-efficacy and 43% of the variance in initial levels of psychological distress. However, PA and NA measured at T1 did not account for any unique variance in the T3 levels of general self-efficacy and psychological distress, after the initial levels of each of the variables were controlled. It was concluded that components of dispositional affect are the main influence on how individuals perceive stimuli in the environment and subsequently regulate their emotional response
Recommended from our members
Body mass index and health care utilization in diabetic and nondiabetic individuals.
BackgroundAlthough controversial, most studies examining the relationship of body mass index (BMI) with mortality in diabetes suggest a paradox: the lowest risk category is above normal weight, versus normal weight in nondiabetic persons. One proposed explanation is greater morbidity of diabetes in normal weight persons. If this were so, it would suggest a health care utilization paradox in diabetes, paralleling the mortality paradox, yet no studies have examined this issue.ObjectiveTo compare the relationship of BMI with health care utilization in diabetic versus nondiabetic persons.DesignPopulation-based cross-sectional study.SubjectsAdults in the 2000-2011 Medical Expenditures Panel Surveys (N=120,389).MeasuresTotal health care expenditures, hospital utilization (≥1 admission), and emergency department utilization (≥1 visit). BMI (kg/m) categories were: <20 (underweight); 20 to <25 (normal); 25 to <30 (overweight); 30 to <35 (obese); and ≥35 (severely obese). Adjustors were age, sex, race/ethnicity, income, health insurance, education, smoking, co-morbidity, urbanicity, region, and year.ResultsAmong diabetic persons, adjusted mean total health care expenditures were significantly lower in obese versus normal weight persons (513-229, 95% CI, -2; P=0.052). Findings for hospital and emergency department utilization exhibited similar patterns.ConclusionsNormal weight diabetic persons used substantially more health care than their overweight and obese counterparts, a difference not observed in nondiabetic persons. These differences support the plausibility of a BMI mortality paradox related to greater morbidity of diabetes in normal weight than in heavier persons
- …