Some physiological effects of the herbicide bromacil (5-bromo-3-sec-butyl-6-methyluracil) on Asparagus officinalis L. : a thesis presented in partial fulfilment of the requirements for the degree of Master of Science at Massey University

The root-absorbed, photosynthesis-inhibiting herbicide bromacil (5-bromo-3-sec-butyl-6-methyluracil) was applied in sand culture to tissue-cultured 18-month-old Mary Washington 500W clone of Asparagus officinalis L. grown under controlled environmental conditions. Dose-response characteristics were determined and ED₂⁰ and ED⁵⁰ values computed by regression analysis for several parameters for asparagus plants exposed to a single application of 0, 2, 4, 8, 16, 32, 64, 128, 256, and 512 p.p.m. bromacil in non-draining pots. The results of this initial broad spectrum studies revealed a drastic decline in visually assessed foliage damage score, shoot growth and root fresh weight, and an increase in shoot death at relatively low concentrations. Good dose-response characteristics were obtained, and time-course data showed that the rate and severity of effects increased with increasing dose. The ED⁵⁰ values 18 days after treatment were: visually assessed damage score, 2.7 p.p.m.; shoot growth, 25 p.p.m.; shoot death, 4.6 p.p.m.; and root fresh weight, 2.1 p.p.m. A catalogue of colour plates showing visual phytotoxic effects was compiled. The injury symptoms observed were: yellowing of cladophyll tips followed by bleaching with the effects extending towards the base, cladophyll tipping and progressive cladophyll death leading to shoot death. Equal increment dose-response experiments were conducted at 0, 2, 4, 6, and 8 p.p.m. bromacil, using a portable fluorometer (Model SF-10) to obtain fluorescence emission measurements. The results showed a dramatic decline in the initial rise in fluorescence yield from the cladophyll tips 156 hours after treatment. The ED⁵⁰ value was computed to be 2.3 p.p.m. Fluorescence emission measurements from cladophyll tips from excised shoots placed in bromacil solution at the same concentrations showed a dramatic decline in fluorescence yield within 17 hours indicating that uptake and translocation was more rapid without the roots. No significant changes in chlorophyll a, chlorophyll b and total chlorophyll concentrations, as determined by 80% acetone extraction technique, were evident in the samples in which a dramatic decline in fluorescence yield occurred. The results of this study, conducted under controlled environmental conditions, showed that the asparagus clone tested readily absorbed bromacil through its roots and translocated it to the foliage causing severe initial damage to the photosynthetic apparatus followed by detrimental effects on other parameters such as shoot growth, root fresh weight and shoot death. Even at a bromacil concentration of 2 p.p.m. the asparagus plants were found to susceptible to herbicide damage

Determinants Of Online Purchase For Agroproducts Among Pasarborong.Com Customers

Online-purchasing for agricultural products in Malaysia is not well received, despite the encouragement by the government and local vendors. This study examines the online purchasing behavior of consumers for selected agricultural products in Malaysia. The research objectives are: to document the profile of online shoppers; to document the types of products that are being purchased online; to determine the consumers behavior towards online purchasing; and to analyze factors affecting online purchases. An online survey was posted at www.geocities.com/sothy_46 . The survey focused only on online shoppers for agro products. Notice of the survey was posted through www.pasarbong.com website. The notice was also sent to the customers through www.parksononline.com.my and www.egroceries.com.my. A total of 46 participants responded. The data were analyzed using mean average, factor analysis, gap analysis and linear regression. Descriptive statistics was used to describe the respondent profile, consumer’s behavior and their beliefs of online purchasing of selected agro- products such as mean average. Factor analysis was used to uncover the dimension of the beliefs of online marketing for selected agro- products. Gap Analysis refers to the activity of studying the differences between standards and the delivery of those standards. Linear Regression model was used to predict the relationship between dependent variable of happy dealing online to independent variables used in the factor analysis. The results showed that a majority of the respondent used e-commerce to purchase services such as, providing reservation/booking online and online banking rather than to purchase goods. The survey also included questions to determine the consumers’ expectation before they first purchase online as well as their perception after they had made online purchases. In general, the experience of the respondents was not up to their expectation. Based on factor analysis, there are five factors which influenced consumer’s perception towards online marketing. They are after sales services, communication, product attribute, satisfaction and delivery. The regression analysis also found that some factors were significant in influencing the level of consumers’ satisfaction regarding online purchasing

Improvement of dye-sensitized solar cells toward the broader light harvesting of the solar spectrum

Dye-sensitized solar cells (DSSCs) have been extensively evolved for the past two decades in order to improve their cell performance. From the commercialization point of view, the overall solar to electrical energy conversion efficiency should compete with other solar cells. But, due to structural restrictions of DSSC using the liquid electrolyte and a space requirement between two electrodes, the direct tandem construction of DSSCs by stacking of repeating units is highly limited. In this feature article, important research trials to overcome these barriers and a recent research trend to improve the light harvesting strategies mainly panchromatic engineering, various tandem approaches such as parallel tandem, series tandem, p-n tandem etc., have been briefly reviewed.close271

Computationally Efficient Blind-Adaptive Algorithms for Multi-Antennal Systems

Multi-input multi-output (MIMO) systems are expected to playa crucial role in future wireless communications and a significant increase of interest in all aspects of MIMO system design has been seen in the past decade. The primary interest of this thesis is in the receiver part of the MIMO system. In this area, continuous interest has been shown in developing blind-adaptive decoding algorithms. While blind decoding algorithms improve data throughput by enabling the system de:signer to replace training symbols with data, they also tend to perform robustly against any environment disturbances, compared to their training-based counterparts. On the other hand, considering the fact that the wireless end user environment is becoming increasingly mobile, adaptive algorithms have the ability to improve the performance of a system regardless of whether it is a blind system or a training-based one. The primary difficulty faced by blind and adaptive algorithms is that they generally are computationally intense. In this thesis, we develop semi-blind and blind decoding algorithms that are adaptive in nature as well as computationally efficient for multi-antenna systems. First, we consider the problem of channel tracking for MIMO communication systems where the MIMO channel is time-varying. We consider a class of MIMO systems where orthogonal space-time block codes (OSTBCs) are used as the underlying space-time coding schemes. For a general MIMO system with any number of transmitting and receiving antenna combinations, a two-step MIMO channel tracking algorithm is proposed. As the first step, Kalman filtering is used to obtain an initial channel estimate for the current block based on the channel estimates obtained for previous blocks. Then, in the second step, the so-obtained initial channel estimate is refined using a decision-directed iterative method. We show that, due to specific properties of orthogonal space-time block codes, both the Kalman filter and the decision-directed algorithm can be significantly simplified. Then, we extend the above receiver for MIMO-OFDM systems and propose a computationally efficient semi-blind receiver for MIMO systems in frequency-selective channels. Further, for the proposed receivers, we have derived theoretical performance analysis in terms of probability of error. Assuming the knowledge of the transmitted symbols for the first block, we have derived the instantaneous signal to interference and noise ratio (SINR) for consecutive transmission blocks in the absence of training, by exploiting Kalman filtering to track the channel in a decision-directed mode. Later, we extend the the theoretical performance limit comparisons for time-domain vs. frequency-domain channel tracking for MIMO-OFDM systems. Further, we study the advantage of adaptive channel tracking algorithms in comptype pilot aided channel estimation schemes in practical MIMO-OFDM systems. After that, an efficient sequential Monte-Carlo (SMC) algorithm is developed for blind detection in MIMO systems where OSTBCs are used as the underlying space-time coding scheme. The proposed algorithm employs Rao-Blackwellization strategy to marginalize out the (unwanted) channel coefficients and uses optimal importance function to generate samples to propagate the posterior distribution. The algorithm is blind in the sense that, unlike the earlier ones, the transmission of training symbols is not required by this scheme. The marginalization involves the computation of (hundreds of) Kalman filters running in parallel resulting in intense computer requirement. We show that, the marginalization step can be significantly simplified for the speci1ied problem under no additional assumptions - resulting in huge computational savings. Further, we extend this result to frequency selective channels and propose a novel and efficient SMC receiver for MIMO-OFDM systems. Finally, a novel adaptive algorithm is presented for directional MIMO systems. Specifically, the problem of direction of arrivall (DOA) tracking of an unknown time-varying number of mobile sources is considered. The challenging part of the problem is the unknown, time-varying number of sources that demand a combination of source enumeration techniques and sequential state estimation methods to track the time-varying number of DOAs. In this thesis, we transform the problem into a novel state-space model, and, by employing probability hypothesis density (PHD) filtering technique, propose a simple algorithm that is able to track the number of sources as well as the corresponding directions of arrivals. In addition to the fact that the proposed algorithm is simple and easier to implement, simulation results show that, the PHD implementation yields superior performance over competing schemes in tracking rapidly varying number of targets.Doctor of Philosophy (PhD

Evaluation of long-term outcomes after anterior cruciate ligament reconstruction. Operative methods, clinical and radiological findings, and their relationship to patient-reported acceptable knee function

The overarching theme of this thesis was to evaluate long-term clinical, subjective and radiological results after anterior cruciate ligament (ACL) reconstruction in regard to: different surgical methods, specifically anatomic single-bundle (SB) and double-bundle (DB) graft techniques (study II); changes in the Knee Osteoarthritis Outcome Score (KOOS) in mid- to long-term follow-up in relation to ACL injury with or without concomitant injuries (study I); tibial tunnel enlargement in anatomic SB and DB ACLR using biocomposite interference screws containing ß-tricalcium phosphate (ß-TCP) (study III); and the definition of the Patient Acceptable Symptom State (PASS) for the KOOS at 5-, 10- and 15- year follow-up in a Swedish population (Study IV). Study I demonstrated that patients with both concomitant meniscal and cartilage injuries reported worse KOOS scores at 10-year follow-up. Study II could not demonstrate any significant difference in any measure examined in the SB and DB ACLR methods. Study III showed 76% of SB patient radiographs did not reveal any tibial tunnel enlargement at 10-year followup compared to early postoperative images. This was the case in 69% of posterolateral (PL) tunnels and 63% of anteromedial tunnels in those participants that received DB ACLR. Study IV showed no change over time for PASS values for KOOS subscales, and that predictive modelling can reliably define PASS. The studies presented here demonstrated the largest depreciation in subjective outcomes via the KOOS at 10-year follow-up in those with concomitant meniscal and cartilage injuries when compared to 5-years previous, providing weight to the argument for performing ACLR before instability events cause concomitant injury; that there was no significant difference in rotational nor anteroposterior (AP) laxity between the SB and DB methods, with similar subjective and radiological OA measures, with the vast majority of radiographs from both cohorts not demonstrating any tunnel enlargement at 10-year follow-up. Finally, robust and reliable PASS cut-offs for the KOOS subscales were defined for 5-, 10- and 15- year follow-up in a Swedish population using a predictive modelling approach, demonstrating a lower PASS-Sports & Recreation cut-off than published data on an American -Norwegian population; suggesting it may not be possible to assume all populations adhere to the same PASS values for the KOOS

BLIND ADAPTIVE MULTIUSER DETECTION OVER TIME-VARYING TIME-DISPERSIVE CHANNELS

In this thesis, blind multiuser detection of Direct Sequence Code Division Multiple Access (DS-CDMA) signals over time-varying time-dispersive channels is considered. A number of methods for multiuser detection over time-dispersive channels have been proposed previously. Blind multiuser detection requires that the signature waveform of the desired user be reconstructed (blindly) at the receiver. In time-dispersive channels the knowledge of the channel order (length) is needed in order to reconstruct the signature waveform exactly. Previous works in this regard assumed the knowledge of the channel length or they considered an over estimated channel length. However, when the channel length assumed at the receiver differs from the actual one, the performance of the system can degrade significantly. Hence we propose a new multiple model approach that considers many channel-conditioned multiuser detectors in parallel in order to obtain a better estimate via soft decision, instead of making a hard decision about the channel length. We use the Interacting Multiple Model (IMM) estimator, which consists of multiple Kalman filters, to find a better overall estimate from the channel-conditioned filters. Further, in a time-varying environment, where the channel length varies with time, the proposed scheme tracks the channel order very well (without assuming known channel length), and hence performs better than previous methods. Simulation results show that the proposed method outperforms the existing ones in terms of signal to interference plus noise ratio and bit error rate in a time-varying channel.Master of Applied Science (MASc

Role overload, leader facilitation, workgroup support, employee recognition and turover intention among lecturers in private university colleges in Negeri Sembilan

Retaining talented lectures in Private Higher Education Institutions (PHEI) become an alarming issue for the PHEI’s managements. Lectures face many difficulties in private higher education institutions compare to public higher education institutions. Some scholars have come up with several factors that could provide the impact on turnover intention. However, studies on the impact of role overload, leader facilitation, workgroup support and employee recognition towards turnover intention specifically among PHEIs’ lectures were very limited. The objective of this study is to identify the role overload, leader facilitation, workgroup support and employee recognition that affect turnover intention among PHEIs lectures in Negeri Sembilan. Research data were obtained from two PHEIs in Negeri Sembilan; Inti International University Nilai and KTG Education Group in Mantin. Total five hypotheses were developed in this study. The quantitative research design used to collect the data. Information was collected through questionnaires and was analyzed by using Statistical Package for Social Science (SPSS) version 16.0. Total 152 respondents were involved in this study. Cross sectional research method has been used to synthesis less biased and more accurate result. This research applied descriptive statistics, reliability analysis and inferential analysis to determine the relationship among the variables. Based on the correlation analysis, it has found that role overload and turnover intention shows a positive relationship (r = .725**, p ≤ 0.01). Meanwhile, leader facilitation (r = -.669**, p ≤ 0.01), workgroup support (r = -.750**, p ≤ 0.01) and employee recognition (r = -.801**, p ≤ 0.01) shows negative relationship. The coefficient of determination value (R2 = 0.709) and indicated that role overload, leader facilitation, workgroup support and employee recognition have contributed 70% to the lecturers’ turnover intention in PHEI in Negeri Sembilan. Based on multiple regression analysis result, it has found that employee recognition (β -.420, p ≤0.00) has the most significant relationship and reported as high contributor for employee turnover intention. Meanwhile, the second highest contributing factor is role overload (β .232, p ≤0.04 ) and following by workgroup support (β -. 195, p ≤0.17). The factor that least contributed for employee turnover intention among (PHEI) in Negeri Sembilan is leader facilitation (β -.086, p ≤0.246). This research study has come up with appropriate suggestions for the (PHEI) management and insights for future researchers and for better researches. This research had fulfilled the objectives set earlier by the researcher