Dispersion pattern and sampling plan for Asian citrus psyllid, Diaphorina citri Kuwayama (Hemiptera: Psyllidae) in a citrus orchard

The ecology of the psyllid and its spatial distribution as the basis for the development of a reliable sampling plan are very important. The abundance and spatial distribution of Diaphorina citri (Hemiptera: Psyllidae) were studied in a commercial citrus orchard in southwestern Sarawak, Malaysia from April 2013 to December 2014. The spatial distribution of D. citri eggs, nymphs and adults were analysed using Taylor’s power law and Iwao’s patchiness regression. Taylor’s power law fitted the data better and produced higher values of R2 than Iwao’s regression model but did not work well with the egg populations. Based on both regression models, the field dispersion patterns of D. citri eggs, nymphs and adults were aggregated among flush shoots in individual trees as indicated by the regression slopes that were significantly >1. By homogeneity tests on both regression methods, the slopes of Taylor’s power law and Iwao’s regression model did not differ significantly for the D. citri population on honey tangerine for both years. The minimum number of flush shoots per tree required for estimates of D. citri densities varied from 2, 4 and 6 flush shoots for adults, nymphs and eggs, respectively, for the average density of each developmental stage obtained during our studies. Prediction suggested that a sampling plan consisting of 10 trees with the optimum number of six flush shoots per tree was required for a reasonably accurate density estimation of the three life stages of D. citri acceptable enough for population studies and pest management program in citrus orchards

Foraminiferal evidence for the intensification of the east Australia current during the LGM

Abstrac

An Economic and Statistical Analysis of Selected Structural Characteristics of Louisiana Agricultural Sector and Its Impact on Resource Situations.

This study focuses on the importance of structural change in the farm sector and its interactive relationship with the nonfarm sector. This relationship was exemplified through an overview and trend analysis of the structural change and resource adjustments that have occurred in the farming areas in Louisiana between 1959 and 1982. Extrapolative forecasting techniques, such as trend extrapolation, Markov Process, negative exponential and age cohort analysis, were used to project changes in farm numbers to the year 2000. The results show declining farm numbers and the continuation of present trends. Large and medium size farms will increase while small and hobby farms will decrease in number. Evaluation results show that trend extrapolation and Markov Process provide better projections than the other two techniques when judged on the basis of mean squared error and mean absolute error. The impacts of selected structural determinants on farm numbers and resource adjustments were estimated by econometric models. Sector interdependency through intersector flow of goods and services formed the conceptual framework of the models. The determinants have a significant impact on structural transformation and resource adjustments in the farm and nonfarm sectors. However, the impacts on different size categories were varied due to differences in the natural resource base, enterprise mix, geographic characteristics, and demographic distribution of the area. Impact multipliers show positive relationships between farm numbers, farm employment and farm earnings. However, negative relationships were estimated for nonfarm employment, nonfarm earnings and total earnings in selected farming areas. The model assumed no area interaction and internalized all resource adjustments which brought about the trade-off effect. Average profit per farm appears to be most promising in promoting economic growth since it has a positive impact on employment, earnings and personal income in all farming areas. Farm earnings were found to have a positive impact on consumption expenditures, nonfarm earnings, total employment, area population and indirectly affects the number of nonbasic business establishments

Knowledge Management and IT Project Success: A Meta-analytic Review

There are fragmented and contradictory findings in relation to the factors influencing IT project success. The aim of this study is to examine the antecedents of IT project success. A meta-analytic review was undertaken using the Comprehensive Meta-Analysis Software. A systematic review of the literature identified 612 articles on IT project success. Of these, 46 articles used a range of constructs in studying IT project success. The meta-analytic review resulted in 24 antecedents of IT project success. The result could be explained by adopting a knowledge management perspective as the antecedents (such as team environment, team process, team integration and social factors) were necessary for the creation, storage and transfer of knowledge in leading to IT project success. Theoretical and practical implications are discussed in relation to understanding the contributions of knowledge management to IT project success

Seasonal Abundance and Suppression of Fruit-Piercing Moth Eudocima phalonia (L.) in a Citrus Orchard in Sarawak

Seasonal population of the fruit-piercing moths Eudocima spp. was monitored throughout the citrus growing seasons in a citrus orchard and in site adjacent to secondary forest from July 2007 to June 2009. The moth was detected practically throughout the year with activity lowest during the wet months (September-February) when fruits are still available and while highest during the dry months (May-June) which also coincided with the main fruiting season. The effects of an nC24 horticultural mineral oil (HMO) on the citrus fruit damage caused by fruit-piecing moths was also determined. The percent fruit damage was significantly lowest (P≤0.05) in HMO-treated plots (8.4), followed by Dimethoate-treated plots (11.6) and untreated plots (22.5). However, there was no significant difference between HMO and Dimethoate treated plots indicating HMO is effective in reducing percent fruit damage

Distribution patterns of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) eggs, nymphs and adults in a Malaysian citrus orchard

Spatial distribution of eggs, nymphs and adults of Diaphorina citri (Hemiptera: Psyllidae) was studied in a commercial orchard in SW Sarawak, Malaysia, using mean–variance test, the index of dispersion, and the negative binomial distribution. To further ascertain and confirm the distribution pattern in the population of the psyllid, dispersion indices (index of mean crowding, Lloyd’s index of patchiness, Taylor’s power law and Iwao’s patchiness regression) were calculated. Measurable tests showed that distribution of eggs and nymphs in naturally occurring psyllid populations was highly aggregated, resulting from initially aggregated migration of adults and a contagious dispersion of them on flushes as the population density increased of metals in the present study can be used as suitable reference for future studies

Local oestrogen therapy modulates extracellular matrix and immune response in the vaginal tissue of post-menopausal women with severe pelvic organ prolapse

This study investigates the effect of local oestrogen therapy (LET) on the expression of proteins participating in collagen/elastin biogenesis and immune markers in vaginal tissues of post-menopausal women with severe pelvic organ prolapse (POP). Vaginal biopsies were collected from the anterior vaginal wall of informed and consented 52 post-menopausal women with severe POP undergoing total hysterectomy. Twenty-nine of the 52 women were treated with LET (in the form of vaginal oestrogen cream or tablet), while the remaining 23 untreated patients served as the controls. This study was approved by Sinai Health System REB. Vaginal tissue specimens were analysed for gene and protein expression using real-time RT-PCR and Luminex assays, protein localization and immune cell infiltration were assessed by immunohistochemistry. Forty-four cytokines were detected. We found that LET application: (a) significantly increased (P \u3c 0.05) gene and protein expression levels of extracellular matrix (ECM) structural proteins, collagen and elastin, as well as the expression of ECM maturation enzyme BMP1; (b) decreased protein expression level of ECM degradation enzymes MMP1, MMP2 and MMP3 accompanied by an increase in their tissue inhibitors, TIMP1 and TIMP4; (c) significantly increased (P \u3c 0.05) the gene and protein expression levels of 14 vaginal cytokines involved in leucocyte infiltration, which was confirmed by immunohistochemistry. Our results indicate that LET plays an important role in the activation of immune system within the local vaginal environment, limiting the undesirable ECM degradation, which supports the strengthening of vaginal ECM in post-menopausal women, therefore resisting menopause/age-related changes and inducing urogenital tract tissue regeneration

Incidence and spread of huanglongbing (HLB) or citrus greening disease in relation to the distribution and fluctuation of Diaphorina citri Kuwayama (Hemiptera: Psyllidae) population in a citrus orchard in Sarawak, Malaysia

Diaphorina citri Kuwayama is a very prolific and most efficient vector for the fast huanglonbing (HLB) transmission which has destroyed nearly all citrus orchards with the economic deficit of RM 6.5 million or USD 1.6 million in Malaysia. D. citri coupled with HLB is therefore the greatest obstacle to the financial development of a sustainable and viable citrus industry in Malaysia. The study was aimed to evaluate the spread of HLB disease vectored by D. citri in relation to its spatial distribution and flight activity in response to flush cycles in a healthy orchard. Four types of yellow traps used to monitor for flight activity of this disease vector were evaluated monthly between June 2011 and December 2012. Both vector populations and HLB disease symptoms were monitored regularly between 2011 and 2014. A molecular diagnostic technique, Polymerase chain reaction (PCR) procedures was used to confirm the presence of the bacterium in diseased trees. D. citri adult populations expanded exponentially amid durations of cyclic production of new flush growths. The highest number of adult D. citri was captured by Rebel brown-yellow traps followed by Bamboo pole and yellow sticky traps with significant differences during the rainy months with monthly rainfall between 581-919 mm from October 2011 to March 2012 while higher catches were obtained by Bamboo pole traps during the dry months with monthly rainfall from 374-458 mm between May – September 2012. Yellow traps provided an indication of adult abundance and flight activity. It took about 21 months for D. citri population to spread all over the entire citrus garden. Rates of HLB transmission were related to high vector populations and spread was related to dispersing adults. Levels of HLB infected trees as determined by PCR increased progressively from 2.4% to 19.3% and 42.2% within four years after planting. The activity of infective D. citri is the key to HLB disease spread in a citrus orchard