Cocksfoot (Dactylis glomerata L.) seed production : a thesis presented in partial fulfilment of the requirements for the degree of Master of Agricultural Science at Massey University

Seed yield reduction due to variation in genotype, management, and incidence of diseases is common and well documented in grass seed crops. Two New Zealand cultivars (Grasslands Wana, Grasslands Kara) and two Japanese (Akimidori Makibamidori) cocksfoot cultivars from a three year old stand (sown in September 1991) at Grassland Aorangi Research Farm in the Manawatu were evaluated for their seed yielding capacity. In addition these cultivars were evaluated to determine the effectiveness of bactericide (Streptomycin), nematicide (Vydate/Oxamyl) or a combinations of bactericide and nematicide to determine their effect on seed yield with traditional Fungicide (Folicur) application being used as a control. The unit plot size was 1.2 X 3.0 m2, with each plot containing 4 rows. randomized block design with two factors (cultivar and pesticide) was utilized with 4 replications. In each cultivar pesticide were sprayed in four replicates from each block. The New Zealand cultivar Wana outyielded the other three cultivar and produced about 23%, 32%, and 70% higher pure seed/unit area than that cvs Kara, Makibamidori and Akimidori respectively. The ability of cv Wana to outyield other cultivar was largely due to its ability to produce a greater numbers of fertile tillers and higher number of florets/head. Seed yields in the New Zealand cultivar Kara and the Japanese cultivar Makibamidori were similar but significantly higher than cv Akimidori. The significantly higher seed yield of cv Kara was due largely to its significantly higher seed weight than the other cultivars. Similarly the higher seed yield in cv Makibamidori compared to Akimidori was mainly due to higher seed weight. The lower pure seed yield in cv Akimidori was apparently due to lack of proper photoperiodic effect or cold temperature during anthesis and its earlier seed developing resulted in more empty florets than the New Zealand cultivar and cv Makibamidori. Fertile tiller numbers spikelets/ head and florets/ head were significantly higher in cv Wana compared to the other 3 cultivars. However, the TSW was low. The TSW was highest in cv Kara. Highest recovery of pure seed was obtained from cv Wana in screen and blown fraction. Highest pure seed was obtained from cv Makibamidori in clean seed fractions. Foliar disease intensity in all the four cultivars was found to be similar at all 3 stages of plant growth although disease levels were generally low. Percentage purity in clean seed as well as in different cleaning fractions varied depending on cultivar but cv Akimidori was always ranked lowest. Seed germination percentage in single and in multiple florets was higher in cv Akimidori compared to the other 3 cultivars. Different cultivars reacted differently to the application of pesticide. Cultivar Wana produced the highest yield 103 g pure seed/m2 in the Fungicide (Folicur) treatment compared to 55, 38 and 22 g/m2 in cv. Kara, Makibamidori and Akimidori respectively. However all cultivars produced lower yields following the application of Streptomycin. Seed yield in cv Akimidori was not affected by any pesticide application. The lower yield in Streptomycin treatments was mainly due its phytotoxic effect on leaf tissue. Seed yield in Fungicide, Vydate and in V+S treated plots was similar but significantly better than in Streptomycin treated plots. Fertile tiller numbers were also similar in these treatments but spikelet and total floret numbers were higher in the V+S treatment than in the Fungicide treatment. TSW and florets/ spikelets was not affected by pesticide application. The recovery of pure seed was always lowest in the Streptomycin treatment in all fractions of machine cleaning of seed but was higher in V+S than Fungicide treatment, particularly in the machine clean fraction. However, the recovery of pure seed from the screen fraction did not vary significantly. Over all the foliar disease severity was low in Fungicide and V+S treatment and highest in Vydate treatment at maturity but no difference during vegetative growth or at peak flowering. The percent purity varied only in the air screen fraction but was high in the Vydate treatment. Seed germination was high in all pesticide treatments and being above 90% in term of single florets and 85% in multiple florets with minor improvement in V+S treatment both in single and multiple florets and in Fungicide treatment with multiple florets only. The second trial involved only one cultivar (cv Tekapo) and involved 4 plots from each block with 3 different types of fungicide Alto (cyproconazole), Bavistin (carbendazim), and Bravo (chlorothalonil) applied from flower initiation to harvest maturity at intervals of 14 to 21 day. No effect of fungicide occurred in seed yield or in yield components. Disease severity varied significantly only at harvest maturity and was lowest in Alto treated plots (2.75) compared to the control (4.25). However, no difference occurred in assessment at the vegetative stages or at peak flowering. No significant effect of fungicide was observed in terms of seed cleaning. The percentage purity was found higher in Alto and Bravo treated plots. Germination results were well above accepted levels (90%) in all fungicide treatments with Bavistin treatments being particularly useful

AnonPri: A Secure Anonymous Private Authentication Protocol for RFID Systems

Privacy preservation in RFID systems is a very important issue in modern day world. Privacy activists have been worried about the invasion of user privacy while using various RFID systems and services. Hence, significant efforts have been made to design RFID systems that preserve users\u27 privacy. Majority of the privacy preserving protocols for RFID systems require the reader to search all tags in the system in order to identify a single RFID tag which not efficient for large scale systems. In order to achieve high-speed authentication in large-scale RFID systems, researchers propose tree-based approaches, in which any pair of tags share a number of key components. Another technique is to perform group-based authentication that improves the tradeoff between scalability and privacy by dividing the tags into a number of groups. This novel authentication scheme ensures privacy of the tags. However, the level of privacy provided by the scheme decreases as more and more tags are compromised. To address this issue, in this paper, we propose a group based anonymous private authentication protocol (AnonPri) that provides higher level of privacy than the above mentioned group based scheme and achieves better efficiency (in terms of providing privacy) than the approaches that prompt the reader to perform an exhaustive search. Our protocol guarantees that the adversary cannot link the tag responses even if she can learn the identifier of the tags. Our evaluation results demonstrates that the level of privacy provided by AnonPri is higher than that of the group based authentication technique

AnonPri: A Secure Anonymous Private Authentication Protocol for RFID Systems

Privacy preservation in RFID systems is a very important issue in modern day world. Privacy activists have been worried about the invasion of user privacy while using various RFID systems and services. Hence, significant efforts have been made to design RFID systems that preserve users\u27 privacy. Majority of the privacy preserving protocols for RFID systems require the reader to search all tags in the system in order to identify a single RFID tag which not efficient for large scale systems. In order to achieve high-speed authentication in large-scale RFID systems, researchers propose tree-based approaches, in which any pair of tags share a number of key components. Another technique is to perform group-based authentication that improves the tradeoff between scalability and privacy by dividing the tags into a number of groups. This novel authentication scheme ensures privacy of the tags. However, the level of privacy provided by the scheme decreases as more and more tags are compromised. To address this issue, in this paper, we propose a group based anonymous private authentication protocol (AnonPri) that provides higher level of privacy than the above mentioned group based scheme and achieves better efficiency (in terms of providing privacy) than the approaches that prompt the reader to perform an exhaustive search. Our protocol guarantees that the adversary cannot link the tag responses even if she can learn the identifier of the tags. Our evaluation results demonstrates that the level of privacy provided by AnonPri is higher than that of the group based authentication technique

Evaluation and validation of passive aeration simultaneous nitrification and denitrification (PASND) in a biofilm reactor for Low-Energy wastewater treatment

In today’s rapidly urbanized and industrialized society, there is an increasing need for cost-effective and environmentally sustainable technologies for the removal of nutrients from the polluted water. Wastewater treatment principally relies on microorganisms for their ability to take up organic substrate and nutrients (i.e., nitrogen) from wastewater. The need for active aeration of the bulk wastewater to provide oxidation power to micro-organisms makes the wastewater treatment process extremely energy intensive. However, a recent study suggests that by exposing the biomass directly to air (passive aeration), the cost associated with aeration could be reduced. This thesis aimed to establish such a pas-sively aerated biofilm (to remove organics and nitrogen from wastewater) from activated sludge in order to investigate its real-world feasibility. To enable cost-effective removal of organic compounds, a biofilm enriched with glyco-gen accumulating organism (GAO) was developed by selective enrichment from acti-vated sludge using sequences of anaerobic flooding followed by aerobic exposure of the biofilm directly to the atmosphere. The transition of activated sludge to the GAO biofilm was completed within eight weeks of continuous selective operation. The GAO biofilm enabled anaerobic removal of organic carbon (biochemical oxygen demand or BOD) from wastewater which was stored intracellularly as poly-hydroxyalkanoate (PHA). The PHA was oxidized in the subsequent aerobic stage to regenerate the biofilm’s BOD stor-age capacity. With using acetate as synthetic BOD, the biofilm demonstrated efficient (>99%) and stable removal of organic carbon at an average rate of 256 mg BOD L-1 h-1. Long-term operation of the established GAO biofilm leads to the very low amount of excess sludge produced. This is of particular interest since sludge disposal cost is the second greatest operational expense in traditional wastewater treatment facilities. The av-erage excess sludge (volatile suspended solids or VSS) production rate was found to be 0.05 g VSS g-1 BOD removed which is about 10-times lower than that of activated sludge process. Factors such as the high biomass content (21.41 g VSS L-1 of reactor) and the low growth yield of GAO were found to be associated with little sludge production. In addition, a high number of a predatory protozoan (Tetramitus) was found inhabiting the biofilm that minimized sludge production by effectively grazing on cells. In order to allow next to organic carbon also nitrogen removal from wastewater, a hybrid biofilm system was developed by incorporating zeolite (an ion-exchange material) into the GAO biofilm and activated sludge as the sole source of nitrifying bacteria. During the anaerobic phase, zeolite adsorbed ammonium which was removed in the subsequent aer-obic stage by the combined action of nitrifying and GAO bacteria via simultaneous nitri-fication and denitrification (SND). The occurrence of SND under full atmospheric partial pressure was confirmed by trickling nitrate solution over the biofilm system which resulted in nitrate reduction in full atmospheric condition. Over four months of continu-ous operation, the biofilm reactor demonstrated sustained BOD (>90%) and nitrogen (about 70%) removal performance with a short hydraulic retention time (HRT) of 5 h (2 h anaerobic and 3 h aerobic phase). The inadequate nitrogen removal efficiency was attributed to the limited capacity (1.474 mg NH4+-N g-1) of the zeolite used in this study. However, a subsequent repeat treatment of the effluent in the same biofilm reactor re-sulted in about 96 % ammonium removal from wastewater. The capability of the GAO biofilm to treat high-strength (up to 4-times) wastewater was evaluated while keeping the same anaerobic duration (2 h). The amount of ammonium adsorbed onto zeolite was found to increase proportionally with influent feed concentration. However, the aerobic time required for zeolite regeneration was longer. Compared to single (1x) and double (2x) strength wastewater, the quadruple (4x) strength synthetic wastewater resulted in nitrite accumulation which took about 5 h (aerobic phase) for complete reduction. Similarly, the BOD removal rate of the biofilm system increased from 543 to 2308 mg L-1 h-1 for 1x and 4x strength wastewater, respectively. The in-creased uptake of BOD by GAO biofilm resulted in the improved storage of PHA (5.02 and 18.6 mmol L-1 for 1x and 4x wastewater, respectively) which contributed to the effi-cient regeneration of zeolite. The biofilm system showed its stability for the treatment of different strength wastewater over a period of 2-months operation suggesting the feasi-bility of 4x or more concentrated wastewater treatment using the proposed biofilm tech-nology with low aeration energy input. To further optimize nitrogen removal performance in the zeolite amended GAO biofilm, several anaerobic and aerobic phases were used while keeping the total treatment time the same (8 h). An increase in the treatment cycles from 2 to 8, increased the nitrogen removal efficiency from 79% to >99%. A simple numerical model was developed that could effectively explain the trends of nitrogen removal in multiple treatment cycles on the basis of the Langmuir ion-exchange isotherm. The main conclusion drawn from the study is that passively aerated GAO biofilm system can be established from standard activated sludge within a reasonable time. The amend-ment of the GAO biofilm by the addition of zeolite as an ammonium adsorbent enables nitrogen removal from wastewater. The proposed biofilm technology has the potential to reduce the energy cost associated with aeration while significantly improving nitrogen removal from high-strength wastewater

The Development and Validation of a One Tier Diagnostic Assessment to Test Premedical Students\u27 Misconceptions about Traumatic Brain Injury

Since brain injury is common in the United States, it is important for health professionals and the public to have accurate knowledge about traumatic brain injury (TBI). Understanding misconceptions is important for health educators, nurses, and physicians, who work with TBI patients. While previous studies on misconceptions about TBI have been undertaken, these have not focused on pre-medical students, nor utilized validated assessments. The purpose of this study was to develop and validate a one tier diagnostic test with a confidence index to determine premedical students\u27 misconceptions about TBI. Using the theoretical framework suggested by Treagust (1986, 1988, and 1995), we developed and validated the Traumatic Brain Injury Knowledge Test (TBIKT) in two phases. The pilot trial, which was an open-ended assessment, had a total of 20 items and 37 participants. This open-ended assessment, along with the literature review, helped in constructing the final multiple choice assessment. The TBIKT (Appendix A) had 43 items with an additional item about students\u27 source of knowledge about TBI. Applying Classical Test Theory and an internal consistency definition for reliability to data from 38 participants, we found that the TBIKT can provide reliable and valid measures of students\u27 knowledge and misconceptions about TBI. Students showed misconceptions in identifying physical, cognitive, and emotional symptoms of TBI. This study also identified several misconceptions about TBI such as it is likely a TBI patient may wake up from the coma without any lasting effects , a TBI patient needs to take rest all of the time, even a little physical exercise may be harmful , and the patient can be completely cured if enough neurons are recruited to take over the loss of the damaged ones . Validity evidence and limitations of the TBIKT are discussed and suggestions for future studies are included

Three essays on agricultural supply analysis

The three essays of this dissertation focus estimating agricultural supply response to price. Using country-specific data and estimating both static and dynamic supply models, this dissertation research provides new estimates and perspectives on global agricultural supply response. The first essay examines the endogeneity of futures prices in supply analysis of four main agricultural crops namely corn, rice, wheat, and soybeans, by revisiting the recent literature that finds substantial endogeneity bias when global crop supply is regressed on futures prices. Our results indicate that the endogeneity of futures price does not affect the estimates of global crop supply responses but affects the estimates of the US crop supply responses. The second essay investigates how the short- and long-run global growing area of corn, soybeans, wheat, and rice respond to international crop output futures prices, price volatilities, and production cost changes by adopting a dynamic heterogeneous panel model. The results indicate that the short- and long-run elasticity estimates of growing-area response with respect to price are considerably lower than the estimates obtained using traditional models. The third essay examines the extent to which crop output prices received by producers and other factors explain changes in intensive and extensive agricultural land use of all crops globally produced. We adopt both static and dynamic panel models to analyze land use response and estimate the respective model using a first-differenced (FD) estimator and a dynamic panel generalized instrumental variable or generalized method of moments (GMM) estimator. The results from FD and dynamic panel GMM estimators indicate that of the total land use response to prices, the response at the intensive margin accounts for a 62-90% of the total response. These results imply that most of the growth in world harvested land 2004 to 2013 resulted from intensification rather than conversion of land that had not previously been cropped