Regulation of hepatic malic enzyme by perfluorodecanoic acid

Perfluorodecanoic acid (PFDA) administration to adult male rats increased both the activity of hepatic malic enzyme and liver weight in a dose-dependent manner. Hepatomegaly and augmented activity of malic enzyme in liver were apparent within one day following PFDA administration and reached a plateau by three days posttreatment. Malic enzyme quantity per liver in PFDA-treated rats was elevated within one day following dosing and increased continually throughout five days posttreatment. Administration of PFDA to rats in the fed state also led to an increase in the specific activity of hepatic malic enzyme that peaked at three days following dosing. When compared to the fed condition, rats fasted for 48 hours had a decrease in both relative liver weight and the quantity of supernatant protein per liver. The total activity (U/liver) and specific activity of malic enzyme in the liver were also reduced in the fasted state. During the 24 hours after treatment in rats fasted for 48 hours, the body weight as well as the absolute and relative liver weight of animals receiving vehicle declined continuously in the absence of feed. Following the administration of PFDA to fasted rats, body weight was maintained until eight hours posttreatment but then declined at a rate similar to that found with the vehicle-treated group. Absolute and relative liver weight in PFDA-treated rats were increased significantly at eight hours posttreatment when compared to those receiving vehicle, and this increment was maintained throughout the rest of the 24 hours following dosing. While the activity and enzyme content of hepatic malic enzyme decreased in the vehicle-treated group, administration of PFDA to rats fasted for 48 hours prevented their decline. The specific activity of hepatic malic enzyme in 48 hours fasted rats receiving PFDA was also elevated significantly at 16 hours posttreatment. Thus, the administration of PFDA to the adult male rat in both the fed and fasted nutritional states was found to regulate hepatic malic enzyme by not only increasing enzyme quantity but also by augmenting the specific activity, (ie, catalytic state) of the enzyme.     

Two closely linked tomato HKT coding genes are positional candidates for the major tomato QTL involved in Na+/K+ homeostasis

The location of major quantitative trait loci (QTL) contributing to stem and leaf [Na⁺] and [K⁺] was previously reported in chromosome 7 using two connected populations of recombinant inbred lines (RILs) of tomato. HKT1;1 and HKT1;2, two tomato Na⁺‐selective class I‐HKT transporters, were found to be closely linked, where the maximum logarithm of odds (LOD) score for these QTLs located. When a chromosome 7 linkage map based on 278 single‐nucleotide polymorphisms (SNPs) was used, the maximum LOD score position was only 35 kb from HKT1;1 and HKT1;2. Their expression patterns and phenotypic effects were further investigated in two near‐isogenic lines (NILs): 157‐14 (double homozygote for the cheesmaniae alleles) and 157‐17 (double homozygote for the lycopersicum alleles). The expression pattern for the HKT1;1 and HKT1;2 alleles was complex, possibly because of differences in their promoter sequences. High salinity had very little effect on root dry and fresh weight and consequently on the plant dry weight of NIL 157‐14 in comparison with 157‐17. A significant difference between NILs was also found for [K⁺] and the [Na⁺]/[K⁺] ratio in leaf and stem but not for [Na⁺] arising a disagreement with the corresponding RIL population. Their association with leaf [Na⁺] and salt tolerance in tomato is also discussed.     

Lion,Ungulate, and Visitor Reactions to Playbacks of Lion Roars at Zoo Atlanta

Felids in captivity are often inactive and elusive in zoos, leading to a frustrating visitor experience. Eight roars were recorded from an adult male lion and played back over speakers as auditory enrichment to benefit the lions while simultaneously enhancing the zoo visitor experience. In addition, ungulates in an adjacent exhibit were observed to ensure that the novel location and increased frequency of roars did not lead to a stress or fear response. The male lion in this study roared more in the playback phase than in the baseline phases while not increasing any behaviors that would indicate compromised welfare. In addition, zoo visitors remained at the lion exhibit longer during playback. The nearby ungulates never exhibited any reactions stronger than orienting to playbacks, identical to their reactions to live roars. Therefore, naturalistic playbacks of lion roars are a potential form of auditory enrichment that leads to more instances of live lion roars and enhances the visitor experience without increasing the stress levels of nearby ungulates or the lion themselves, who might interpret the roar as that of an intruder.     

eBird: engaging birders in science and conservation

How do you successfully engage an audience in a citizen-science project? The processes developed by eBird (www.ebird.org), a fast-growing web-based tool that now gathers millions of bird observations per month, offers a model.     

Production of endothelial progenitor cells obtained from human Wharton's jelly using different culture conditions

Endothelial progenitor cells (EPC) participate in revascularization and angiogenesis. EPC can be cultured in vitro from mononuclear cells of peripheral blood, umbilical cord blood or bone marrow; they also can be transdifferentiated from mesenchymal stem cells (MSC). We isolated EPCs from Wharton's jelly (WJ) using two methods. The first method was by obtaining MSC from WJ and characterizing them by flow cytometry and their adipogenic and osteogenic differentiation, then applying endothelial growth differentiating media. The second method was by direct culture of cells derived from WJ into endothelial differentiating media. EPCs were characterized by morphology, Dil-LDL uptake/UEA-1 immunostaining and testing the expression of endothelial markers by flow cytometry and RT-PCR. We found that MSC derived from WJ differentiated into endothelial-like cells using simple culture conditions with endothelium induction agents in the medium.     

The accuracy of several multiple sequence alignment programs for proteins

Background  

There have been many algorithms and software programs implemented for the inference of multiple sequence alignments of protein and DNA sequences. The "true" alignment is usually unknown due to the incomplete knowledge of the evolutionary history of the sequences, making it difficult to gauge the relative accuracy of the programs.     

Microbial population dynamics on Golden Delicious apples from bud to harvest and effect of fungicide applications

The microbial population dynamics on apples cv. Golden Delicious were analysed every 15 days between bud and harvest in a fully replicated experiment in northern Spain in 1994 and 1995. The total microbial populations varied with developmental stage, and with prevailing climatic conditions. The predominant mycroflora were the filamentous fungi Cladosporium and Alternaria spp. and white and pink yeasts. Other genera isolated included mainly species of Epicoccum, Fusarium and Acremonium. However, the most important post-harvest pathogens Penicillium expansum and Botrytis cinerea were seldom isolated from ripening apples. Maximum total filamentous fungal populations occurred after fruit set and during early ripening [2 × 10⁴cfu (colony-forming units) g^-1 approximately] while those of bacteria were maximum at bud stage (3.5 × 10⁵and 3.0 × 10⁴ cfu g^-1 in 1994 and 1995 respectively). White yeasts were more numerous than pink yeasts. Endophytic infection of apple buds by Alternaria spp., responsible for core rot, was found in almost all bud tissue. By contrast, Cladosporium spp. were initially isolated later from 12.5–50% of tissue samples during blooming and fruit set. The impact of a four-spray fungicide regime during apple development significantly decreased the total filamentous fungal populations in both years, and that of Cladosporium spp. in 1994. However, bacterial populations were often higher on apples from fungicide-treated plots. Fungicide sprays decreased populations of Cladosporium, Alternaria and white yeasts for a maximum of up to 15–30 days after application. Fungicide application had little effect on endophytic infection of apples by Alternaria spp. between bud and harvest.     

Role of external calcium in homeostasis of intracellular pH in the cyanobacterium Anabaena sp. strain PCC7120 exposed to low pH

The role of external Ca²⁺ in the homeostasis of intracellular pH (pHi) of Anabaena sp. strain PCC7120 in response to a decrease in the external pH (pHex) has been studied in cell suspensions. Increase in cytoplasmic pH after acid shock is dependent on the presence of Ca²⁺ in the medium. The observed Ca²⁺-mediated alkalization of the cytoplasm depends on the extent of the shift in external pH. Acid pH shifts resulted in an increased permeability of the cytoplasmic membrane to protons, which could be reversed by increasing the concentration of Ca²⁺ in the medium. Thus, the ability of Ca²⁺ to increase cytoplasmic pH might be correlated with an inhibition of net proton uptake by increasing concentrations of external Ca²⁺ under these conditions. This combined response resulted in the generation and maintenance of a larger pH gradient (ΔpH) at acid external pH values. All Ca²⁺ channel blockers tested, such as verapamil and LaCl₃, inhibited the observed Ca²⁺-mediated response. On the other hand, the Ca ionophore calcimycin (compound A23187) was agonistic, and stimulated both cytoplasmic alkalization and inhibition of net proton uptake. The protonophorous uncoupler carbonylcyanide m -chlorophenyl hydrazone, inhibited this Ca²⁺-mediated response, whereas monensin, an inhibitor of the Na⁺/H⁺ antiporter, had no significant effect. The results of the present study suggest that an influx of Ca²⁺ from the extracellular space is required for the regulation of cytoplasmic pH in Anabaena sp. strain PCC7120 exposed to low external pH values.     

Diagnostic criteria for diabetes revisited: making use of combined criteria

Background  

Existing cut-offs for fasting plasma glucose (FPG) and post-load glucose (2hPG) criteria are not equivalent in the diagnosis of diabetes and glucose intolerance. Adjusting cut-offs of single measurements have not helped so we undertook this project to see if they could be complementary.     

TASTE GROUP THRESHOLDS AND SENSORY EVALUATION OF SPANISH WINE VINEGARS

Wine vinegar is a product obtained from wine acidification which contains at least 5% by wt. of acetic acid, in general without any additives or colorings.
Aspects studied in this work include: the determination of the taste group thresholds (geometric mean of the individual best-estimate thresholds "BET") of two different acids (citric and acetic acids) in aqueous solution and spanish vinegars produced from table and sherry wines. The results obtained suggest that wine vinegar can be considered something more than just an acidulant agent.
In order to evaluate differences among wine vinegars, discriminant tests for twenty-five spanish vinegars (sherry, table and flavored vinegars) were applied. Six of the twelve attributes freely chosen by assessors allowed grouping of the spanish wine vinegars according to their sensory aspects.