Growth, production and quality of pineapple in response to herbicide use

In pineapple fields, weed competition is exacerbated by the fact that the crop is small and has a very slow vegetative development. The objective of this study was to determine the effects of herbicides on growth, yield and quality of pineapple, cultivar 'Pérola'. The experimental design was in randomized blocks with four treatments and four replications. Treatments consisted of weeding by hoe and the herbicides diuron; fluazifop-p-butyl and atrazine + S-metolachlor applied in post-emergence. The characteristics evaluated monthly during the vegetative stage were stem diameter, D-leaf length, number of leaves, number of emitted leaves and percentage of natural floral induction. In the reproductive phase, evaluations were made of average fruit weight (g) with and without crown, fruits length and diameter, number of slip, slip-sucker and sucker type seedlings, determination of soluble solids and pH in the pulp. There was no effect of herbicide treatment on the vegetative growth characteristics. Stem diameter increased until 330 days after planting, showing a decrease after this period. The D-leaf grew over time in all treatments, although phytotoxicity symptoms were observed after the first application of herbicides. The traits evaluated on the reproductive phase showed no significant differences in response to treatments. Therefore, the use of diuron fluazifop-p-butyl and atrazine + S-metolachlor did not affect growth, yield and fruit quality of pineapple, cultivar 'Pérola'.

Persistence of tracer in the application site -a potential confounding factor in nerve regeneration studies

Selective reinnervation of peripheral targets after nerve injury might be assessed by injecting a first tracer in a target before nerve injury to label the original neuronal population, and applying a second tracer after the regeneration period to label the regenerated population. However, altered uptake of tracer, fading, and cell death may interfere with the results. Furthermore, if the first tracer injected remains in the target tissue, available for 're-uptake' by misdirected regenerating axons, which originally innervated another region, then the identification of the original population would be confused. With the aim of studying this problem, the sciatic nerve of adult rats was sectioned and sutured. After 3 days, to allow the distal axon to degenerate avoiding immediate retrograde transport, one of the dyes: Fast Blue (FB), Fluoro-Gold (FG) or Diamidino Yellow (DY), was injected into the tibial branch of the sciatic nerve, or in the skin of one of the denervated digits. Rats survived 2-3 months. The results showed labelled dorsal root ganglion (DRG) cells and motoneurones, indicating that late re-uptake of a first tracer occurs. This phenomenon must be considered when the model of sequential labelling is used for studying the accuracy of peripheral reinnervation.

Long-term persistence of immunity induced by OVA-coupled gas-filled microbubble vaccination partially protects mice against infection by OVA-expressing Listeria.

Vaccination aims at generating memory immune responses able to protect individuals against pathogenic challenges over long periods of time. Subunit vaccine formulations based on safe, but poorly immunogenic, antigenic entities must be combined with adjuvant molecules to make them efficient against infections. We have previously shown that gas-filled microbubbles (MB) are potent antigen-delivery systems. This study compares the ability of various ovalbumin-associated MB (OVA-MB) formulations to induce antigen-specific memory immune responses and evaluates long-term protection toward bacterial infections. When initially testing dendritic cells reactivity to MB constituents, palmitic acid exhibited the highest degree of activation. Subcutaneous immunization of naïve wild-type mice with the OVA-MB formulation comprising the highest palmitic acid content and devoid of PEG2000 was found to trigger the more pronounced Th1-type response, as reflected by robust IFN-γ and IL-2 production. Both T cell and antibody responses persisted for at least 6 months after immunization. At that time, systemic infection with OVA-expressing Listeria monocytgenes was performed. Partial protection of vaccinated mice was demonstrated by reduction of the bacterial load in both the spleen and liver. We conclude that antigen-bound MB exhibit promising properties as a vaccine candidate ensuring prolonged maintenance of protective immunity.

Post-partum persistence of abnormal circadian pattern of blood pressure after preeclampsia [109-POS]

OBJECTIVES: Blunted nocturnal dip of blood pressure (BP) and reversed circadian rhythm have been described in preeclampsia (PE). Non-dipper status and preeclampsia are both associated with an increased risk of cardiovascular disease later in life. Complete recovery of BP in PE is reported to occur over a variable period of time. Twenty-four hours-ambulatory blood pressure measurement (ABPM) in the post-partum follow-up after a PE has not been described. The aim of this study was to assess 24h-ambulatory blood pressure pattern after a PE and to determine the prevalence of non-dipper status, nocturnal hypertension, white coat hypertension and masked hypertension. METHODS: This is an observational, prospective study on women who suffered from a preeclampsia. A 24h-ABPM was done 6 weeks post-partum at the Hypertension Unit of the University Hospitals of Geneva, concomitantly with a clinical and biological evaluation. RESULTS: Forty-five women were included in a preliminary analysis. Mean age was 33±6years, 57.3% were Caucasian, mean BMI before pregnancy was 24±5kg/m(2). Office and ambulatory BP are shown in Table 1. Prevalence of nocturnal hypertension was high and half of the women had no nocturnal dipping. The diagnosis of hypertension based on office BP was discordant with the diagnosis based on ABPM in 25% of women. CONCLUSIONS: The prevalence of increased nighttime BP and abnormal BP pattern is high at 6weeks post-partum in preeclamptic women. Early assessment of BP with ABPM after preeclampsia allows an early identification of women with persistent circadian abnormalities who might be at increased risk. It also provides a more accurate assessment than office BP. DISCLOSURES: A. Ditisheim: None. B. Ponte: None. G. Wuerzner: None. M. Burnier: None. M. Boulvain: None. A. Pechère-Bertschi: None.

Low Dynamics, High Longevity and Persistence of Sessile Structural Species Dwelling on Mediterranean Coralligenous Outcrops

There is still limited understanding of the processes underlying benthic species dynamics in marine coastal habitats, which are of disproportionate importance in terms of productivity and biodiversity. The life-history traits of long-lived benthic species in these habitats are particularly poorly documented. In this study, we assessed decadal patterns of population dynamics for ten sponge and anthozoan species that play key structural roles in coralligenous outcrops (~25 m depth) in two areas of the NW Mediterranean Sea. This study was based on examination of a unique long-term photographic series, which allowed analysis of population dynamics over extensive spatial and time spans for the very first time. Specifically, 671 individuals were censused annually over periods of 25-, 15-, and 5-years. This long-term study quantitatively revealed a common life-history pattern among the ten studied species, despite the fact they present different growth forms. Low mortality rates (3.4% yr−1 for all species combined) and infrequent recruitment events (mean value of 3.1±0.5 SE recruits yr−1) provided only a very small fraction of the new colonies required to maintain population sizes. Overall, annual mortality and recruitment rates did not differ significantly among years; however, some species displayed important mortality events and recruitment pulses, indicating variability among species. Based on the growth rates of these 10 species, we projected their longevity and, obtained a mean estimated age of 25-200 years. Finally, the low to moderate turnover rates (mean value 0.80% yr−1) observed among the coralligenous species were in agreement with their low dynamics and persistence. These results offer solid baseline data and reveal that these habitats are among the most vulnerable to the current increases of anthropogenic disturbances.

Persistence of stapedial artery: a case report

Persistent stapedial artery is a rare congenital anomaly that occurs by a failure in the involution of such artery. Most patients with persistent stapedial artery are asymptomatic. The imaging diagnosis is made principally by means of multidetector computed tomography. In the present case, persistent stapedial artery was an incidental computed tomography finding. The authors discuss the embryogenesis, computed tomography findings and the importance of an early diagnosis of such anomaly.

Estudo da adsorção/dessorção do ácido 2,4 diclorofenoxiacético (2,4d) em solo na ausência e presença de matéria orgânica

The herbicides are being used in huge quantities for various porpouses. Once the herbicide finds its way into the environment, a major part of it comes in contact with soil. Humic substances are major organic constituents of soil. These substances may interact with herbicides in different modes and adsorption is probably the most important one. Adsorption will control the quantity of herbicide in the soil solution, and determines its persistence, leaching, mobility and bioavailability. In this work we studied the interaction between the herbicide 2,4D and soil in the presence and absence of organic matter. The methodology utilized for the determination of 2,4D was gas chromatography with eletron capture detector. The behavior of 2,4D was evaluated through Freundlich isotherms. It was verified that the herbicide 2,4D has a large adsorption in the humic acid .

Performance persistence of equity funds in the Russian stock market

This thesis investigates performance persistence among the equity funds investing in Russia during 2003-2007. Fund performance is measured using several methods including the Jensen alpha, the Fama-French 3- factor alpha, the Sharpe ratio and two of its variations. Moreover, we apply the Bayesian shrinkage estimation in performance measurement and evaluate its usefulness compared with the OLS 3-factor alphas. The pattern of performance persistence is analyzed using the Spearman rank correlation test, cross-sectional regression analysis and stacked return time series. Empirical results indicate that the Bayesian shrinkage estimates may provide better and more accurate estimates of fund performance compared with the OLS 3-factor alphas. Secondly, based on the results it seems that the degree of performance persistence is strongly related to length of the observation period. For the full sample period the results show strong signs of performance reversal whereas for the subperiod analysis the results indicate performance persistence during the most recent years.

On performance persistence in emerging markets: Empirical evidence from Asia-Pacific

The purpose of this study is to investigate the performance persistence of international mutual funds, employing a data sample which includes 2,168 European mutual funds investing in Asia-Pacific region; Japan excluded. Also, a number of performance measures is tested and compared, and especially, this study tries to find out whether iterative Bayesian procedure can be used to provide more accurate predictions on future performance. Finally, this study examines whether the cross-section of mutual fund returns can be explained with simple accounting variables and market risk. To exclude the effect of the Asian currency crisis in 1997, the studied time period includes years from 1999 to 2007. The overall results showed significant performance persistence for repeating winners when performance was tested with contingency tables. Also the annualized alpha spreads between the top and bottom portfolios were more than ten percent at their highest. Nevertheless, the results do not confirm the improved prediction accuracy of the Bayesian alphas.

Rapid and accurate hplc-dad method for the determination of the herbicide bispyribac-sodium in surface water, and its validation

A new method is described for the determination of the herbicide bispyribac-sodium in surface water, especially from river and irrigated rice water samples. The method involves extraction in solid phase and quantification by high performance liquid chromatography with diode array detection (HPLC-DAD). After optimization of the extraction and separation parameters, the method was validated. The method presented average recoveries of 101.3 and 97.7%, under repeatability and intermediate precision conditions, respectively, with adequate precision (RSD from 0.9 to 7.5%). The method was applied for the determination of bispyribac-sodium in surface water samples with a limit of detection of 0.1 μg L-1.

GLOBAL AND LOCAL REACTIVITY DESCRIPTORS FOR PICLORAM HERBICIDE: A THEORETICAL QUANTUM STUDY

In this work, we studied the reactivity of picloram in the aqueous phase at the B3LYP/6-311++G(2d,2p) and MP2/6-311++G(2d,2p) levels of theory through global and local reactivity descriptors. The results obtained at the MP2 level indicate that the cationic form of picloram exhibits the highest hardness while the anionic form is the most nucleophilic. From the Fukui function values, the most reactive site for electrophilic and free radical attacks are on the nitrogen in the pyridine ring. The more reactive sites for nucleophilic attacks are located on the nitrogen atom of the amide group and on the carbon atoms located at positions 2 and 3 in the pyridine ring.

Atrazine bound residues formation and dissipation in subtropical soil under swine wastewater application

The effects of swine wastewater on atrazine dissipation and formation of bound residues in subtropical clay soil were investigated in this study. The experiment was carried out in laboratory, under room conditions, where samples of Rhodic Hapludox soil received 168.61 mg kg-1 of atrazine and were incubated for 60 days in the following treatments: T1 (sterilized soil + swine wastewater), T2 (sterilized soil + distilled water), T3 (Non sterilized soil + swine wastewater) and T4 (Non sterilized soil + distilled water). The extractable residues and bound residues of atrazine were extracted and analyzed by high performance liquid chromatography. The results showed no effect of swine wastewater on atrazine dissipation. However, the addition of swine wastewater favored the increase of bound residues, which can increase the persistence of atrazine in the environment and reduce its bioavailability.

Chasing performance persistence of hedge funds

The thesis examines the performance persistence of hedge funds using complement methodologies (namely cross-sectional regressions, quantile portfolio analysis and Spearman rank correlation test). In addition, six performance ranking metrics and six different combinations of selection and holding periods are compared. The data is gathered from HFI and Tremont databases covering over 14,000 hedge funds and time horizon is set from January 1996 to December 2007. The results suggest that there definitely exists performance persistence among hedge funds and the strength and existence of persistence vary among fund styles. The persistence depends on the metrics and combination of selection and prediction period applied. According to the results, the combination of 36-month selection and holding period outperforms other five period combinations in capturing performance persistence within the sample. Furthermore, model-free performance metrics capture persistence more sensitively than model-specific metrics. The study is the first one ever to use MVR as a performance ranking metric, and surprisingly MVR is more sensitive to detect persistence than other performance metrics employed.

Acute toxicity and histopathological alterations of Roundup® herbicide on "cachama blanca" (Piaractus brachypomus)

Acute toxicity of the glyphosate -N (phosphonomethyl) glycine- herbicide, Roundup®, in juveniles of cachama blanca, (Piaractus brachypomus), was evaluated and the histopathological lesions were assessed. The 96 h lethal concentration 50 was 97.47mg.L-1 (P<0.05). In the gill, necrotic and proliferative lesions were detected. In the liver, congestion, degenerative foci, hyaline droplets and lipidic vacuolization of the hepatocytes were observed. In the stomach mild hyperplasia of mucous cells was detected, which was also observed in the skin. In this latter tissue, a large increase in the thickness of the epidermis with necrotic lesions, infiltration of leukocytes and melanin pigment were observed. In the brain, degenerative foci of neuronal bodies in the telencephalon associated with gliosis and infiltration of eosinophilic granule cells/mast cells were shown. In conclusion, gills, liver, skin and brain are susceptible to Roundup®. Moreover, effects on the central nervous system could affect olfaction as well as individual and group behavior, the reproductive performance of the fish and hence have repercussions at the population level.