Miracle-dz/UniFAR-FTUs huggingface dataset:
Structure‐Activity Analyses of β‐Amyloid Peptides: Contributions of the β25–35 Region to Aggregation and Neurotoxicity

Abstract: The neurodegeneration of Alzheimer's disease has been theorized to be mediated, at least in part, by insoluble aggregates of β‐amyloid protein that are widely distributed in the form of plaques throughout brain regions affected by the disease. Previous studies by our laboratory and others have demonstrated that the neurotoxicity of β‐amyloid in vitro is dependent upon its spontaneous adoption of an aggregated structure. In this study, we report extensive structure‐activity analyses of a series of peptides derived from both the proposed active fragment of β‐amyloid, β25–35, and the full‐length protein, β1–42. We examine the effects of amino acid residue deletions and substitutions on the ability of β‐amyloid peptides to both form sedimentable aggregates and induce toxicity in cultured hippocampal neurons. We observe that significant levels of peptide aggregation are always associated with significant β‐amyloid‐induced neurotoxicity. Further, both N‐ and C‐terminal regions of β25–35 appear to contribute to these processes. In particular, significant disruption of peptide aggregation and toxicity result from alterations in the β33–35 region. In β1–42 peptides, aggregation disruption is evidenced by changes in both electrophoresis profiles and fibril morphology visualized at the light and electron microscope levels. Using circular dichroism analysis in a subset of peptides, we observed classic features of β‐sheet secondary structure in aggregating, toxic β‐amyloid peptides but not in nonaggregating, nontoxic β‐amyloid peptides. Together, these data further define the primary and secondary structures of β‐amyloid that are involved in its in vitro assembly into neurotoxic peptide aggregates and may underlie both its pathological deposition and subsequent degenerative effects in Alzheimer's disease.
Nutritional evaluation of very low glucosinolate canola meal

Two very low glucosinolate (VLG) canola meals from crop years 1987 and 1988 (CM; 1.66 and 0.53 μmol g−1) and two Tobin CM (B. campestris) (10.71 and 15.62 μmol g−1) were evaluated in experiments with pigs. In exp. 1, 1987 Tobin CM, VLG-CM and soybean meal (SBM) were compared in individually fed meal and pelleted diets. Daily gains from 23 to 57 kg were similar for the CMs (VLG-CM 662 g, Tobin CM 645 g) but lower than those obtained with SBM (730 g; P < 0.01). Daily feed intakes of pigs fed CM were lower than for those fed SBM (P < 0.05). Plasma thyroxine (T4) levels were similar for SBM and VLG-CM and were above those from pigs fed Tobin (P < 0.05) CM. Triiodothyronine (T3) levels were lower for VLG-CM than for SBM (P < 0.05) and the T3 value for Tobin CM was intermediate. Pelleting enhanced T3 (0.70 vs 0.94 ng mL−1) and T4 (50 vs. 60 ng mL−1) levels with all protein supplements (P < 0.01). In exp. 2, similar diets were fed ad libitum. Daily gains for SBM were greater than for Tobin CM (803 vs. 744, P < 0.
Phytotoxicity of Clippings from Creeping Bentgrass Treated with Glyphosate1

Recent advances in genetic engineering have led to the development of glyphosate-resistant (GR) crops for genetic markers and selective weed control. The effects of glyphosate residue on turfgrass clippings could be toxic to non-GR species. The objective of this experiment was to determine whether glyphosate would retain activity within clippings of creeping bentgrass when applied to Kentucky bluegrass and perennial ryegrass. Greenhouse-grown ‘Penncross’ and GR ‘ASR-368’ were treated with glyphosate at 2.24 kg/ha. Clippings were collected 1, 3, 7, and 12 d after application and applied to greenhouse-grown Kentucky bluegrass and perennial ryegrass. Kentucky bluegrass and perennial ryegrass dry weight and percent cover were reduced by clippings receiving glyphosate that were harvested 1 and 3 d after glyphosate application from both susceptible and resistant creeping bentgrass. Results indicate that glyphosate remains active in clippings for up to 3 d after treatment within creeping bentgrass clippings. Glyphosate-applied creeping bentgrass clippings will need to be managed to prevent injury to susceptible species. Nomenclature: Glyphosate; creeping bentgrass, Agrostis stolonifera L. ; Kentucky bluegrass, Poa pratensis L. ; perennial ryegrass, Lolium perenne L. Additional index words: Clippings, glyphosate, mulch, turfgrass. Abbreviations: DAT, days after treatment; GR, glyphosate resistant; GRCB-G, glyphosate-resistant creeping bentgrass treated with glyphosate; PCB-G, Penncross creeping bentgrass treated with glyphosate; PCB-UTC, Penncross creeping bentgrass untreated control; UTC, untreated control.
Loss of rRNA loci in autotetraploid Parnassia palustris (Celastraceae)

Abstract A study of two varieties of Parnassia palustris L. var. palustris and var. condensata Travis & Wheldon (Celastraceae) by means of fluorescent in situ hybridisation has shown that autotetraploid populations of both taxa display the same number of 18S–26S rDNA loci as their diploid counterparts, rather than double the complement. Mitotic preparations of diploid and tetraploid var. palustris revealed six (five in one tetraploid accession) sites of hybridisation, whereas in both diploid and tetraploid var. condensata four sites were detected. Each site was located in a subtelomeric position on a separate chromosome. These findings contrast with most previous studies of autopolyploids, in which numbers of such loci have been reported to be twice that found in the diploid genome.
Applicability of full inversion tillage to semi-natural grassland restoration on ex-arable land

The application of full inversion tillage (FIT) for the creation of semi-natural grasslands on ex-arable land raises the question of its influence on the availability of soil mineral nutrients as increased soil fertility may cause competitive exclusion of the target plant species. This work is an attempt to answer how FIT influences the availability of N, P, K and Mg and associated soil properties and accordingly how to use this method so that elevated nutrients availability during the establishment of semi-natural grassland species could be avoided. An experiment was conducted in 2-ha area of abandoned fields in east Poland, on Rendzic, Cambic Leptosol and Mollic Gleysol. The area was divided into 8-m-wide strips, every second of which was subjected to FIT; 19 pairs of permanent plots were regularly allocated across the area, each pair containing a plot located on a cultivated strip and a plot on the neighbouring control strip. The comparison of soil properties within the pairs resulted in no significant differences, except for a lower K status in the FIT plots. Presumably FIT did not change the soil conditions in a way which could affect the intensity of the inter-specific competition in a newly created plant community.
Análise do mercado brasileiro de celulose, 1969-2005

The wood pulp and paper sector contributes significantly for the Brazilian economy . The knowledge of the wood pulp market structure is important for production planning, commercialization and forecast for the sector. The main objective of the present study it to specify and estimate the domestic supply and demand of wood pulp, as well as the export supply and demand functions, in the period from 1969 to 2005. The results provided by' the two-stage least squares method (TSLS) indicated that domestic and export supply and demand of wood pulp are price inelastic. The domestic demand is inelastic in relation to income while the export demand is elastic in relation to income. The domestic supply is more affected by changes in machinery and equipment prices. The export supply is affected by changes in production and domestic demand while the export demand is affected by changes in the income of the importing countries.
Growth, diet, movement, and abundance of adult banded kokopu (Galaxias fasciatus) in five Coromandel, New Zealand streams

Abstract Banded kokopu populations were surveyed seasonally over 1 year in five Coromandel streams to determine the influence of food supply on diet, growth, abundance, and movement. Streams with high benthic invertebrate abundance and drift of aquatic origin had high fish abundance. However, terrestrial drift was the dominant food for adult banded kokopu over all seasons and streams, on average comprising 75% of their diet by number and 89% by weight. Annual growth rates of tagged individuals ranged from 3 mm to 16.5 mm, with smaller fish growing faster than large fish. Low growth rates of large fish were consistent with the recapture of a fish that had only grown from 195 mm to 215 mm in 7 years. Our observations confirmed the strong association between banded kokopu, pool habitat, and cover, and also indicated that high fish abundance restricted growth rates and movement and increased interaction.
Determination of phytic acid in cereals - a brief review.

Summary Phytic acid is the major storage form for phosphorus in the cereal grains. It exists in the form of mixed salts of Ca–Mg–K (i.e. phytate), and occurs in many locations within the kernel. This form of phosphorus is not available to monogastric animals, including humans, because they lack the enzyme phytase in their digestive tract. In order to permit a better understanding of the functions and heritability of phytic acid, a literature search was conducted to review the development of procedures for the determination of phytic acid. Starting from a basic method of precipitation as insoluble ferric phytate in acid solution, the techniques for the determination of phytic acid have progressed through many kinds of instrumental methods such as colorimetric, synchronous fluorescence, isotachophoresis, high-performance ionic chromatography, and high-performance liquid chromatography.
Water status and carbohydrate pools in tulip bulbs during dormancy release

Summary • Changes in the physical state of cellular water and its interrelations with carbohydrate metabolism were studied during preplanting storage of tulip bulbs (Tulipa gesneriana‘Apeldoorn’). • Magnetic resonance imaging, light and scanning electron microscopy and high-performance anion exchange chromatography with pulsed amperometric detection were used to follow time-dependent changes during bulb storage at 17 or 20°C (nonchilled) or 4°C (chilled). • No visible differences in scale structure and central bud development were observed microscopically between chilled and nonchilled bulbs. However, the scales of the chilled bulbs exhibited higher water content, faster starch degradation and increased concentrations of sucrose and ethanol-soluble fructan. Quantitative measurements of magnetization transfer (MT) indicated a smaller fraction of a solid or a restricted-mobility proton pool in the scales of the chilled bulbs. By contrast, the MT effect was significantly higher in the central bud of the chilled than in the nonchilled bulbs. • Degradation of storage polysaccharides to low-molecular-weight sugar molecules during release from dormancy could be accompanied by local release of water molecules tightly bound to the polysaccharide granules into the bulk water, or by an influx of free water molecules due to increased osmotic potential caused by the raised sugar concentration, or by a combination of both effects.
Testing the suitability of the Nepal-Somers stand table projection method for Eucalyptus grandis plantations in South Africa

This study presents an application of a stand table projection method for varying stand densities of Eucalyptus grandis in South Africa. The projections of diameter at breast height (dbh) class frequencies are compatible with future values of basal area and stem number per hectare. The application requires an individual tree dbh growth function, a current stand table, and estimates of future basal area, and tree survival. The resulting stand table is adjusted by an algorithm that guarantees that the future stand table is compatible either with observed or predicted values of basal area and stem number per hectare. The results, based on a relatively small experimental dataset, are satisfactory. However, further work based on a larger dataset is required to evaluate the general suitability of the method for stand table projection of Eucalyptus grandis in South Africa, especially regarding variable site conditions. The particular contribution of this study is the fact that we were able to demonstrate the suitability of the Nepal and Somers stand table projection method for a unique dataset from a very densitysensitive Correlated Curve Trend spacing trial. We also made an attempt to present a comprehensive example of a projection to facilitate practical application of this method in the KwaZulu-Natal coastal plain of South Africa.
Old and new host-parasitoid associations: parasitism of the invasive fruit fly Bactrocera invadens (Diptera: Tephritidae) and five African fruit fly species by Fopius arisanus, an Asian opiine parasitoid

Abstract Fopius arisanus (Sonan), a solitary koinobiont endoparasitoid of fruit flies, was introduced for testing and final release against the recently discovered species Bactrocera invadens Drew, Tsuruta and White in Africa. Laboratory experiments were conducted to assess host preference, host acceptability for oviposition, and physiological suitability of B. invadens and five other indigenous tephritid fruit fly species, namely, Ceratitis capitata (Wiedemann) (Diptera: Tephritidae), C. cosyra (Walker), C. rosa Karsch, C. fasciventris (Bezzi), and C. anonae Graham. Females of F. arisanus visited all host egg patches, but showed a stronger preference to eggs of B. invadens, which was also most accepted for oviposition. Successful development of parasitoid progenies varied greatly across hosts, with B. invadens yielding the highest parasitoid progeny and C. fasciventris yielding no F. arisanus progeny. Most of the parasitoid eggs laid in C. rosa and C. fasciventris were encapsulated. Sex ratio was not influenced by host species and it was female biased in all hosts that produced parasitoid progeny. Fopius arisanus was able to establish a new association with C. capitata, C. cosyra and to a lesser extent C. anonae. The results are discussed in the light of the potential use of F. arisanus as a biological control agent of B. invadens.
Alterations in NF-κB function in transgenic epithelial tissue demonstrate a growth inhibitory role for NF-κB

Stratified epithelium contains a mitotically active basal layer of cells that cease proliferating, then migrate outwards and undergo terminal differentiation. The control of this process, which is abnormal in cutaneous neoplasia and inflammation, is not well understood. In normal epidermis, NF-κB proteins were found to exist in the cytoplasm of basal cells and then to localize in the nuclei of suprabasal cells, suggesting a role for NF-κB in the switch from proliferation to growth arrest and differentiation. Functional blockade of NF-κB by expressing dominant-negative NF-κB inhibitory proteins in transgenic murine and human epidermis produced hyperplastic epithelium in vivo. Consistent with this, application of a pharmacologic inhibitor of NF-κB to intact skin induced epidermal hyperplasia. In contrast, overexpression of active p50 and p65 NF-κB subunits in transgenic epithelium produced hypoplasia and growth inhibition. These data suggest that spatially restricted NF-κB activation occurs in stratified epithelium and indicate that NF-κB activation in this tissue, in contrast to its role in other settings, is important for cellular growth inhibition.
The use of a covariance analysis to compare derived linear regressions in stocking rate trials

An analysis of covariance allows statistical comparison of derived data. However, it has not as yet been related to the Jones and Sandland (1974) model. In this paper the analysis of variance is therefore assessed in terms of relationships which are used in the Jones and Sandland model. If this method of analysis is used, four to six stocking rates are recommended in order to ensure that statistical significance is meaningful. Keywords: covariance analyses|linear regressions|stocking rates|analyses|statistical analyses|models|grazing|pastures|animal performance|KwaZulu Natal Province|methods|treatments
Carbamate and Synthetic Pyrethroid Insecticides for Control of Organophosphate-Resistant Southern Chinch Bugs (Heteroptera: Lygaeidae)

Tests conducted on residential lawns in southern Florida confirmed resistance to the organophosphate insecticide, chlorpyrifos, in Blissus insularis Barber. A carbamate, propoxur, and two synthetic pyrethroids, fenvalerate and pennethrin, provided good control of the resistant southern chinch bug populations.
Inter-Nest Variability in the Egg to Hatchling Mass Ratio in the Common Pochard Aythya ferina: Does Female Body Mass Matter?

Abstract. Offspring survival and subsequent fitness are assumed to increase with offspring size. Although the relationship between egg size and young size in birds has attracted considerable scientific attention, to our knowledge no study so far has investigated differences among nests with respect to this relationship. The aim of this study was to find out 1) whether some inter-nest variation in the egg mass — young mass relationship exists among nests of Common Pochards, and 2) whether such a variation could be attributed to the body mass of the female measured in the last 5 days of incubation. Egg mass explained a higher portion of the variability in young mass in nests of heavier females. Those females produced smaller young for eggs of a given size. We suggest a trade-off between current and future reproduction as being the evolutionary mechanism underlying the relationship between female body mass and hatchling body mass.
Evaluation of the nutritional quality of “Tom Brown” weaning diets

The nutritional quality of “Tom Brown” weaning diet was assessed in this study. “Tom Brown” diet was prepared from the combination of equal proportions of ground maize, groundnut, soybean and guinea corn. The nutritional quality of “Tom Brown” was evaluated from its total nitrogen and protein contents, compared to the contents in Basal and Reference diets. Also, the diets were fed to rats for 10 days to assess the protein quality of the diets. The results showed that the total nitrogen and protein contents of Tom Brown were significantly higher (P 0.05) from those obtained for rats on reference diet. The weight change obtained for rats on “Tom Brown” was insignificantly higher (P>0.05) than that obtained for rats on reference diet. The results of this study showed that “Tom Brown” is generally of higher nutritional quality compared to those of other diets. KEYWORDS: Nutritional quality, “Tom Brown” weaning diet.
The zonal expression of α‐fetoprotein transgenes in the livers of adult mice

The developmental regulation of the α‐fetoprotein (AFP) gene in liver results in high‐level expression in the fetus, followed by dramatic transcriptional repression after birth. We have examined the mouse AFP gene for transcriptional control sequences that may be involved in its postnatal repression in liver. We showed previously that removal of a DNA region between positions −250 base pairs (bp) and −838 bp of the AFP gene resulted in the persistence of expression of an AFP minigene in the postpartum liver of transgenic mice (Vacher and Tilghman, Science 250:1732–1735, 1990). This study examines the distribution of these transgene transcripts in liver using in situ hybridization. We show that there is a zonal distribution of minigene transcripts in the adult livers of these animals. Hepatocytes surrounding the central veins express high levels of minigene transcripts, while hepatocytes in the intermediate and portal areas contain few, if any, transcripts. Quantitative RNAse protection analysis shows a decrease in transgene RNA levels after birth, consistent with repression in all but a small subset of hepatocytes. These results indicate that repression in the pericentral hepatocytes is dependent upon the presence of a cis‐acting, negative‐regulatory domain, which is located between the enhancers and the proximal promoter of the AFP gene. In contrast, this domain is not essential for complete repression of AFP transgenes in the intermediate zone and periportal hepatocytes. © 1992 Wiley‐Liss, Inc.
Prey selection by the predatory leech Nephelopsis obscura in relation to three alternative models of foraging

Prey selection by a predatory leech, Nephelopsis obscura, was examined in a series of laboratory experiments. Two chironomids, Glyptotendipes paripes and Chironomus riparius, and the tubificid worm, Tubifex tubifex, were used as alternative prey. These three prey are all tube dwellers found in the same microhabit at the mud–water interface. The quality of each of the three prey types was estimated by their ability to promote the growth of the leeches. The two chironomids were much superior prey than Tubifex. Mixed diets did not improve growth. The selectivity of starved leeches offered equal densities of the two chironomids was not affected by the absolute abundance of prey. After 72 h the selectivity was biased toward Chironomous, the more mobile prey, and this bias increased with prey density. Varying the relative abundance of these two prey did not alter the selectivity of the leeches with a single exception. When Chironomus was the more abundant prey, selectivity was biased towards it, but this disapp.
Differential expression of CYP3A12 and CYP3A26 mRNAs in canine liver and intestine

The cytochrome P450 (CYP) 3A family is often considered the most important CYP subfamily with regard to drug metabolism in people. Certainly, CYP3A4 contributes to poor oral bioavailability of a number of drugs, and a tremendous amount of effort has been made in attempting to find an appropriate model system to predict the oral bioavailability of candidate drugs. The dog is a species widely used as a preclinical model for the evaluation of drug safety and pharmacokinetics. Compared with other species, little information is available on the tissue distribution of CYP enzymes. The purpose of this study was to determine the level of messenger RNA (mRNA) expression of the canine CYP3A subfamily (CYP3A12 and CYP3A26) in the liver and duodenum. Overall, expression of CYP3A mRNA was greater in the liver than in the duodenum. Hepatic expression of CYP3A26 was greater than CYP3A12 in all dogs, with CYP3A26 comprising 75.2% of the hepatic mRNA CYP3A pool. Conversely, duodenal expression of CYP3A12 was greater than CYP3A26 in all dogs, with CYP3A12 comprising 99.8% of the duodenal mRNA CYP3A pool. In summary, these results represent an important step toward the systematic comparison of human and canine CYP3A enzymes, particularly in relation to oral bioavailability of substrate drugs.
Problems in filtration fractionation of 14C primary productivity samples

Sources of error in the fractionation of 14C primary productivity samples were studied in the northern Baltic from 1984 to 1990. Acidification of the whole 14C sample followed by 24 h in open vials to remove 14CO2 (no bubbling) proved to be a simple, accurate, and precise (C.V. 6.9%, n = 128) method for measuring apparent net primary productivity (total organic 14C). In 1985, the total recovery of organic 14C with 0.2-µm cellulose acetate filters was 81% of the annual apparent net primary production. Different post-filtration treatments of the cellulose ester filters (rinsing, acidification) all gave significant unaccountable losses of up to 34% of organic 14C. No losses were recorded with glass-fiber filters. Excess release of dissolved organic 14C due to filtration was generally unimportant, as only minor quantitative or qualitative differences were found between the <0.2-µm filtrates of the whole and centrifuged samples.