Authors:I. Lamprecht, C. Maierhofer, and M. Röllig
Thermal investigations using infrared (IR) thermometry and false colour
thermography were carried out on flowering plants in the Botanical Garden
of Berlin and in a private garden. Special interest went to phototropic plants
that orient their blossoms towards a light source (mainly the sun) and within
this group to solar trackers (heliotropism) that follow the path of the sun
during the day. Best known among the latter is the sunflower. Bowl shaped
flowers comparable to satellite disks focus the solar radiation effectively
on their centre, resulting in a warming of the female organs at that point.
Temperature differences above ambient can be as high as 10.7 K with a mean
value of 6.0 K. Pollinating insects were often observed sun-basking in the
bowls or on the flower disks attracted by energetic rewards in form of nectar
A new method is
introduced to agricultural practice for measuring the living active root of the
plants. The measured root capacitance is interpreted in electro-chemical
principles. In addition to the electrochemical interpretation of the
measurements we aimed to find a non-wounding electrode instead of the needle
plant electrode. Another reason for dealing with the tweezer plant electrode
was to decrease the relatively high standard deviation of the root capacitance
readings due to the relatively high uncertainty of hitting the xylem with the
needle plant electrode. To improve and standardize the contact between the
tweezer plant electrode and the stem a high electrical conductivity gel
(UNIGEL) was applied on the stem before clipping the tweezers. Experiments for the root capacitance
measurements were made in temperature and light controlled climate chambers
(Conviron, Canada) in 2 litre plastic pots filled with 4:1 soil:sand mixture
and water culture. Comparison of the root
capacitances of five-week old sunflower plants measured with the needle and the
tweezer plant electrodes proved identical in water culture and capillary water
saturated soil. However, the applicability of the tweezer plant electrode needs
further study for other plants and environmental conditions. The effect of
measurement frequency on root capacitance and resistance with the HP4284A
impedance bridge was also studied to see the effectiveness of polarization
(Figure 1). From Figure 1 it can be seen
that root capacitance decreased at frequencies above 1 kHz, while it increased
up to the dielectric constant of water at lower frequencies. An interpretation
of measurable root capacitance in the soil-plant system is given using separate
measured plant tissue and soil capacitances. We established that root
capacitance in the soil-plant system approximates the capacitance of the root
tissue. Good correlation was found
between root capacitance and the calculated root surface area (RA) for
sunflower plants (Figure 2). The GW
LCR-814 was found suitable for making root capacitance measurements. Finally,
further experimental work is needed to collect information for the more general
and extended applicability of the method before it becomes a routine tool in
ecological and agricultural practice.
Authors:Carmen Solcan, Dorina Timofte, Viorel Floristean, Stuart Carter, and Gheorghe Solcan
A study was conducted to evaluate the nephrotoxic effect of ochratoxin A (OTA) in broiler chickens. Forty Ross 308 broilers (6 days old) were divided into two groups: one group received daily, by gavage, ochratoxin A at a daily dose of 50 μg/kg body weight for up to 21 days, while the control group received only diluent (sunflower oil). After 21 days, the chickens were euthanised and the kidneys removed for analysis by histopathology and immunohistochemistry to detect an anti-apoptotic marker (Bcl-2), and by transmission electron microscopy. Macroscopically the kidneys were enlarged, showing degeneration and gout deposits. Histologically, glomerulonephrosis and tubulonephrosis were common lesions in all chicks. In two of the five chicks exposed to OTA for 21 days, focal tubular cell proliferation, multiple adenoma-like structures and Bcl-2-positive epithelial cells were identified in layers of the renal papilla and in convoluted tubules. Transmission electron microscopy of the proximal convoluted tubules identified abnormal forms of mitochondria. The nephrotoxic effect of ochratoxicosis in chickens is probably due to carcinogenic changes induced in the epithelial tissues.
Authors:J. Belovai, R. Romvári, H. Fébel, M. Mézes, D. Bánáti, and A. Szabó
Replacement of animal fat with plant oils is a very popular research field, due to the increasing prevalence of cardiovascular diseases in association with saturated fatty acid consumption. The aim of this study was to reduce amount of pig backfat in a meat product (Párizsi) and to partially replace it with soybean- (SBL) or sunflower lecithin (SFL). Between the samples difference was realized in fatty acid (FA) profile, mostly in total n6 FA content. The replacement also altered the colour compared to the control. The oxidative stability (MDA) analysis showed that SBL was more prone towards preparation technology (10 nmol MDA/g) than the Sfl(9 nmol MDA/g). The lecithin appeared as foreign taste based on the sensory test. The aromatic difference, as assessed with electronic nose, was clearly detectable between Sfland SBL. The increasing supplementation levels were also properly distinguished with discriminant analysis within the SBL and Sflseries. Summarized, Sflwas found to be a better antioxidant, but SBL improved the FA profile into a more favourable state. The lecithin-replacement made unlikeness in the taste compared to the control.
Authors:Erika Tóth, Tamás Tauber, Balázs Wirth, Marcell Nikolausz, Márton Palatinszky, Peter Schumann, and Károly Márialigeti
The effect of several easily degradable substrates, such as protein, starch and sunflower oil was investigated on the bacterial community of a laboratory-scale biogas model system. Besides measuring gas yield, Denaturing Gradient Gel Electrophoresis (DGGE), Phospholipids Fatty Acid Analysis (PLFA) for Bacteria and T-RFLP analysis of the mcrA gene for Archaea were used. The community of the examined biogas reactors adapted to the new substrates through a robust physiological reaction followed by moderate community abundance shifts. Gas yield data clearly demonstrated the physiological adaptation to substrate shifts. Statistical analysis of DNA and chemotaxonomic biomarkers revealed community abundance changes. Sequences gained from DGGE bands showed the dominance of the phyla Bacteroidetes and the presence of Firmicutes (Clostridia) and Thermotogae. This was supported by the detection of large amounts of branched 15-carbon non-hydroxy fatty acids in PLFA profiles, as common PLFA markers of the Bacteroidetes group. Minor abundance ratios changes were observed in the case of Archaea in accordance with changes of the fed substrates.
Observations of the flight of the western corn rootworm (WCR) were made necessary by its appearance and settling in 2004 and by the possibilities of control. Therefore studies were carried out using Pherocon AM traps in a 111,1 ha maize stand sown after sunflower. The 6 traps were placed at the edge and in the inside of the field, respectively. The influence of the meteorological elements on flight was determined by comparing the temperature and precipitation to the flight of WCR adults.The results obtained with the traps unambiguously pointed to the late summer, one-peak adult flight of the WCR. The rather late mass flight can be attributed to the influence of climatic factors. Toward the end of the vegetation cycle of maize, beside the appearance in high individual numbers (an average of 141 and 142 adults trapped a week) the proportion of gravid females (25–28% on 29 July; 38–42% on 5 August) was found to increase in the area, which forecasts a mass appearance of the next year’s generation. The traps at the edge of the field caught a higher number of adults than those in the inside [averages of the trapping controls for traps at the edge: 3,00 (trap 1.); 2,67 (trap 2.); 3,44 (trap 3.); 2,78 (trap 4), while for the inner traps: equally 4,56 (trap 5.,6.)] Toward the end of flight the difference decreased.
Authors:K. Szentmihályi, A. Blázovics, I. Kocsis, Edit Fehér, B. Lakatos, and Péter Vinkler
The metabolic alteration of fatty liver causes significant changes in the composition of bile fluid secreted by epithelial liver cells. These processes include both organic molecular and inorganic ion content changes in bile juice as well. In this work ion concentration differences of bile fluid in experimental hyperlipidemic rats compared to normal ones were monitored. Fatty liver in young male Wistar albino rats was induced by 2% cholesterol, 20% sunflower oil and 0.5% cholic acid added to the normal food and 3% alcoholic water was administered to rats for 9 days. The development of hyperlipidemy was detected by measuring serum parameters and fatty liver was proved by morphological investigations. The ion concentrations of bile fluid samples were determined by ICP-OES (inductively coupled plasma optical emission spectrometry). The bile fluid samples were digested with a mixture of HNO3 and H2 O2 . The results show that the concentration of calcium and phosphorus in bile juice increased significantly in hyperlipidemic rats compared to the control. Significant concentration changes have also been detected for chromium and manganese. The changes in metal ion metabolism also point to the damage of liver cells owing to metal complex evacuation.