bluuebunny/crossref_metadata_2025_split huggingface dataset:
Estrogen modulates sexually dimorphic contextual fear extinction in rats through estrogen receptor β
Authors: Chang Yao‐Ju , Yang Chih‐Hao , Liang Ying‐Ching , Yeh Che‐Ming , Huang Chiung‐Chun , Hsu Kuei‐Sen 
Published: March 2009

AbstractFemales and males are different in brain and behavior. These sex differences occur early during development due to a combination of genetic and hormonal factors and continue throughout the lifespan. Previous studies revealed that male rats exhibited significantly higher levels of contextual fear memory than female rats. However, it remains unknown whether a sex difference exists in the contextual fear extinction. To address this issue, male, normally cycling female, and ovariectomized (OVX) female Sprague‐Dawley rats were subjected to contextual fear conditioning and extinction trials. Here we report that although male rats exhibited higher levels of freezing than cycling female rats after contextual fear conditioning, female rats subjected to conditioning in the proestrus and estrus stage exhibited an enhancement of fear extinction than male rats. An estrogen receptor (ER) β agonist diarylpropionitrile but not an ERα agonist propyl‐pyrazole‐triol administration also enhanced extinction of contextual fear in OVX female rats, suggesting that estrogen‐mediated facilitation of extinction involves the activation of ERβ. Intrahippocampal injection of estradiol or diarylpropionitrile before extinction training in OVX female rats remarkably reduced the levels of freezing response during extinction trials. In addition, the locomotion or anxiety state of female rats does not vary across the ovarian cycle. These results reveal a crucial role for estrogen in mediating sexually dimorphic contextual fear extinction, and that estrogen‐mediated enhancement of fear extinction involves the activation of ERβ. © 2009 Wiley‐Liss, Inc.
Glutamate spillover augments GABA synthesis and release from axodendritic synapses in rat hippocampus
Authors: Stafford Misty M. , Brown Molly N. , Mishra Puneet , Stanwood Gregg D. , Mathews Gregory C. 
Published: March 2009

AbstractTight coupling between gamma‐aminobutyric acid (GABA) synthesis and vesicle filling suggests that the presynaptic supply of precursor glutamate could dynamically regulate inhibitory synapses. Although the neuronal glutamate transporter excitatory amino acid transporter 3 (EAAT3) has been proposed to mediate such a metabolic role, highly efficient astrocytic uptake of synaptically released glutamate normally maintains low‐extracellular glutamate levels. We examined whether axodendritic inhibitory synapses instratum radiatumof hippocampal area CA1, which are closely positioned among excitatory glutamatergic synapses, are regulated by synaptic glutamate release via presynaptic uptake. Under conditions of spatially and temporally coordinated release of glutamate and GABA within pyramidal cell dendrites, blocking glial glutamate uptake enhanced quantal release of GABA in a transporter‐dependent manner. These physiological findings correlated with immunohistochemical studies revealing expression of EAAT3 by interneurons and uptake of D‐asparate into putative axodendritic inhibitory terminals only when glial uptake was blocked. These results indicate that spillover of glutamate between adjacent excitatory and inhibitory synapses can occur under conditions when glial uptake incompletely clears synaptically released glutamate. Our anatomical studies also suggest that perisomatic inhibitory synapses, unlike synapses within dendritic layers of hippocampus, are not capable of glutamate uptake and therefore transporter‐mediated dynamic regulation of inhibition is a unique feature of axodendritic synapses that may play a role in maintaining a homeostatic balance of inhibition and excitation. © 2009 Wiley‐Liss, Inc.
Application of the fuzzy‐oil‐drop model to membrane protein simulation
Authors: Zobnina Veronica , Roterman Irena 
Published: March 2009

AbstractThe analysis of structural properties and biological activity of membrane proteins requires long lasting simulation of molecular dynamics. The large number of atoms present in protein molecule, membrane (phospholipids), and water environment makes the simulation of large scale. The implementation of simplified model representing the natural environment for membrane proteins is presented and compared with the vacuum simulation and simulation in the presence of water molecules and membrane phospholipids presented explicite. The comparative structural analysis and computational times for these three models makes the simplified model promising. Proteins 2009. © 2009 Wiley‐Liss, Inc.
Electrochemically initiated tagging of thiols using an electrospray ionization based liquid microjunction surface sampling probe two‐electrode cell
Authors: Van Berkel Gary J. , Kertesz Vilmos 
Published: March 2009

AbstractThis paper reports on the conversion of a liquid microjunction surface sampling probe (LMJ‐SSP) into a two‐electrode electrochemical cell using a conductive sample surface and the probe as the two electrodes with an appropriate battery powered circuit. With this LMJ‐SSP, two‐electrode cell arrangement, tagging of analyte thiol functionalities (in this case peptide cysteine residues) with hydroquinone tags was initiated electrochemically using a hydroquinone‐doped solution when the analyte either was initially in solution or was sampled from a surface. Efficient tagging (∼90%), at flow rates of 5–10 µL/min, could be achieved for up to at least two cysteines on a peptide. The high tagging efficiency observed was explained with a simple kinetic model. In general, the incorporation of a two‐electrode electrochemical cell, or other multiple electrode arrangement, into the LMJ‐SSP is expected to add to the versatility of this approach for surface sampling and ionization coupled with mass spectrometric detection. Published in 2009 by John Wiley & Sons, Ltd.
Sugar Cane Policosanols do not Reduce LDL Oxidation in Hypercholesterolemic Individuals
Authors: Kassis Amira N. , Kubow Stan , Jones Peter J. H. 
Published: March 2009

AbstractSugar cane policosanols (SCP) have been shown to exert antioxidant properties in various studies conducted in Cuba. Independent studies have since reported no significant effect of SCP consumption on oxidized LDL levels. The objective of the present study was to confirm the effects of Cuban SCP on LDL oxidation using a high‐precision capture ELISA procedure in hypercholesterolemic individuals. Twenty‐one otherwise healthy hypercholesterolemic men and post‐menopausal women participated in a randomized double blind crossover study where they received 10 mg/day of policosanol or a placebo incorporated in margarine as an evening snack for a period of 28 days. Subjects maintained their usual dietary and exercise habits throughout the duration of the study. Blood was collected on the first as well as the last 2 days of the trial. LDL oxidation was measured from plasma using a solid phase two‐site enzyme immunoassay. A lack of effect of SCP was observed on LDL cholesterol levels, as well as no difference in LDL oxidation between the SCP treatment and placebo at the end of the intervention period. Subject body weights remained stable throughout the study and showed no significant correlation with LDL oxidation levels. Absolute levels of plasma LDL cholesterol were significantly (P < 0.05) correlated with plasma concentrations of oxidized LDL. The findings of the present study suggest that SCP do not significantly affect LDL oxidation. Our results align with results of recent policosanol research questioning the efficacy of these natural extracts as cardio‐protective agents.
ELEMENTARY PROOFS OF VARIOUS FACTS ABOUT 3-CORES
Authors: HIRSCHHORN MICHAEL D. , SELLERS JAMES A. 
Published: March 2009

AbstractUsing elementary means, we derive an explicit formula for a3(n), the number of 3-core partitions of n, in terms of the prime factorization of 3n+1. Based on this result, we are able to prove several infinite families of arithmetic results involving a3(n), one of which specializes to the recent result of Baruah and Berndt which states that, for all n≥0, a3(4n+1)=a3(n).
The pantothenic acid content of poultry feeding stuffs
Authors: Bondi A. , Etinger R. , Meyer H. 
Published: March 2009

A suitable modification of the microbiological method for assaying pantothenic acid was developed and the pantothenic acid content in various kinds of poultry-feeding stuffs determined by its use. To assure quantitative liberation of the total amount of the pantothenic acid from the samples it is recommended to digest the samples first with Clarase.Pantothenic acid content was determined in poultry feeds of animal origin, such as fish-meal, meat-scrap, liver-meal and different kinds of milk-powder. It is remarkable that different kinds of fish-meal differ markedly in their pantothenic acid content.
Mortality, weight and body measurements at birth of Dairy Shorthorn calves
Authors: Braude R. , Walker D. M. 
Published: March 2009

1. Records of mortality of Dairy Shorthorn heifer calves in the N.I.R.D. herd from 1924 to 1946 were analysed and show a total loss of 16·3%. Losses due to abortions amounted to 5·1%, to stillbirths 6·3%, and post-natal losses in calves up to 6 months of age, 4·8%.2. The mean adjusted length of gestation period for 230 Dairy Shorthorn cows was 285·6 days.3. Calves carried longer were heavier at birth, the average increase in weight amounting to 0·91 lb. per day of gestation.4. The adjusted mean birth weight of the calves was 81·68 lb. Bull calves are carried longer than heifer calves by about 1·68 days and they are heavier at birth by about 3·29 lb.5. The birth weight of 111 heifer calves born between 1940 and 1947 was 79·9 lb. as compared with the value obtained before the war of 87·0 lb. for 285 heifer calves.Some factors affecting the weight of the calf at birth were studied; including the effect of artificial mating.
The growth of lambs before and after birth in relation to the level of nutrition
Authors: Wallace L. R. 
Published: March 2009

SUMMARYIn the investigation described in this third part of the work, we have studied the effect of imposing two extreme levels of diet upon the pregnant ewe during two periods, one of early and one of late, gestation. In order to build up a comprehensive picture of the effect of these treatments we have been concerned, first, with the changes that they have wrought in the tissues and organs of the mother's body; secondly, with the effect upon the growth and development of the genital tract and its major components, and lastly with the way in which the growth of the tissues and organs of the foetus have responded to the different nutritive levels. While the latter has been our primary concern, the former have been studied in some detail so that we may view the effects produced as a whole, and gain an understanding of any competition that may have occurred between maternal and foetal tissues.
The changing of treatments in a long-term trial
Authors: Pearce S. C. , Taylor J. 
Published: March 2009

SUMMARYThe changing of treatments during the course of an experiment is discussed both from the point of view of designing trials in which changes are anticipated and of modifying trials that have fulfilled their original purpose. Cases are distinguished according to whether the interactions of original and new treatments are or are not important and recommendations are made for each case.We are indebted to Miss J. M. S. Thom for preparing the diagrams fot publication.
The effects of singling and advancing season on the composition of thousand-headed kale
Authors: Jones D. J. C. 
Published: March 2009

1. Five varieties of thousand-headed kale, grown in singled and unsingled plots, were sampled three times during the winter at monthly intervals. The plants were divided into leaf, top half of the stem and bottom half. Dry matter, the proximate constituents and minerals were determined in the samples.2. The differences in the composition of the leaf and stem of the plant were similar to those found previously and the top half of the stem was intermediate in composition between the leaf and the bottom half of the stem for all the constituents except potassium.3. The proportions of the various constituents occurring in the three portions of the plant were calculated and considered in terms of the incomplete utilization of the crop by grazing animals.4. There were significant increases in the percentage of dry matter in all three portions of the plant as the season advanced. The only other significant changes in composition with advancing season were in the leaf in which the levels of crude protein, crude fibre, ash, calcium, phosphorus and sulphate varied.5. Singling the crop had no significant effects on its composition, but there was a tendency for the stems of the singled crop to be lower in crude fibre and higher in crude protein and several of the minerals.6. There were very few differences in the composition of the varieties. They were mainly due to the higher mineral levels in one variety.7. Samples of the two halves of the stem of thousand-headed kale were divided into their main tissues, e.g. rind, xylem and marrow. These were analysed in the same manner as the samples in the main investigation. The results were used in an attempt to explain the effects of singling, advancing season and variety in terms of different ratios of these tissues.
Comparison of three practical rations for growing pigs
Authors: Braude R. , Lyon Marilyn R. , Rowell J. G. 
Published: March 2009

A co-ordinated trial has been carried out at twenty-six centres to compare the effects of three practical rations on performance and carcass quality of fattening pigs. The simplest of these was the ‘Shinfield ration’ (SR) and this was compared with the more elaborate National Pig Progeny Testing Station rations, the ‘old’ ration (OPT) as used until January 1963 and the ‘new’ ration (NPT) as used since January 1963.The OPT ration was significantly worse than the SR and NPT rations in respect of growth rate and food conversion. The simpler and cheaper SR ration did not differ significantly from the NPT ration. Ration differences were not significant for any carcass measurements.
A study of the voluntary intake of food and water and the lactation performance of cows given diets of varying roughage contentad libitum
Authors: Owen J. B. , Miller E. L. , Bridge P. S. 
Published: March 2009

SUMMARYTwelve Friesian heifers were given four dietary treatments from 2 months before first calving to the end of the first lactation. Two of the treatments involved thead libitumfeeding of a complete diet consisting of a basal concentrate meal of rolled barley with supplements, incorporated into a mixture with either hay or barley straw both coarsely ground and included at a level of 25 % of the complete mix. In the other two treatments either the hay or the straw was givenad libitumin the long form and the concentrate mix fedad libitumfrom a separate self-feeder.Full records were kept of the intake of food and water, the output and quality of the milk and of live weight. Detailed measurements were made of various aspects of rumen function using one cow on each treatment fitted with a cannula. Rumen samples were also obtained from non-fistulated cows by stomach tube.The intake of long roughage, particularly straw, by the cow, when offered in conjunction with a separate supply of the concentrate mix, was very low and led to serious falls in milk butterfat content. Where the roughage was incorporated into the complete diet normal butterfat levels were maintained. However, apart from the depressed butterfat levels on the two long roughage treatments the health and condition of the cows remained good.The very low intake of long straw was associated with a smaller volume of liquid in the rumen, a reduced rate of flow of liquid leaving the rumen, a lower proportion of acetic and butyric acids and a greater proportion of propionic acid in the rumen liquor and finally with a higher blood glucose content. The inclusion of milled roughage resulted in values within the normal range for volume of liquid in the rumen, flow rate of liquid from the rumen, V.F.A. proportions in the rumen liquor and blood glucose.The intake of both food and water over the productive cycle showed a consistent pattern for all cows. Food intake reached its lowest point around calving followed by a sharp rise to a peak in the 4th month after calving and then a gradual but increasing decline. Water intake followed a similar pattern but the fluctuation was greater and the peak consumption occurred in the 3rd month of lactation. Water intake was more closely associated with D.M. intake than with milk output.The efficiency of utilization of the complete diets containing the milled roughages is discussed in relation to comparable data from cattle fed conventionally.
Shorn and unshorn Awassi sheep IV. Skin temperature and changes in temperature and humidity in the fleece and its surface
Authors: Eyal E. 
Published: March 2009

1. A comparison was made between the skin temperature, humidity and temperature within and on the surface of the fleece of unshorn and shorn sheep. This study was conducted during various seasons of the year, at different environmental temperatures, while sheep were maintained in the shade or subjected to direct sunlight.2. Accompanying the rise of ambient temperature (in the shade) from 10 to 43° C. there was an increase in skin temperature from 34 to 40° C. and from 28 to 40° C. of the unshorn and shorn sheep, respectively.3. The relationship between the rise in skin temperature and that of ambient temperature was not linear, but showed a stepwise pattern in which the ‘breaks’ occurred at similar environmental temperatures for both groups, although skin temperatures of shorn sheep were lower than the unshorn.4. The diurnal change in skin temperature of the shorn sheep was similar to that of the ambient temperature. The decrease in skin temperature of unshorn sheep sometimes lagged behind the fall in environmental temperature. The seasonal variations between summer and winter were more significant in shorn than in unshorn sheep.5. Fleece surface temperatures measured at the same ambient temperatures ranged between 13 and42° C. and 16·5–39·5° C. in the unshorn and shorn sheep, respectively. In the break points of the rise in skin temperature, there occurred a drop in temperature gradients between the skin and fleece surface. This probably indicates a rise in thermal conductivity of the fleece at these points.6. The temperature gradient per unit of fleece thickness is inversely related to the depth of fleece and is greater the nearer to the skin.7. With exposure to the sun, skin temperatures of both groups greatly increased and occasionally reached 47° C. Under these conditions the differences between shorn and unshorn groups were not consistent.8. Fleece temperatures of unshorn sheep increased greatly upon exposure to the sun. The maximal temperatures were recorded midway between the fleece surface and skin. These temperatures generally reached 55° C. and sometimes even exceeded 60° C.9. At ambient temperatures of 30–35° C. the vapour pressure close to the skin of unshorn sheep ranged between 35–40 mm. Hg. With shorn sheep, however, the vapour pressure close to the skin was similar to that of the environment. In Yotvata there was a rise in vapour pressure close to the skin when the ambient temperature increased to 40–43° C. This rise in humidity was paralleled by a rise of vapour pressure throughout the wool. It was not linear but rather showed a ‘step-wise’ pattern.10. The vapour pressure in fleece and near the skin of sheep subjected to direct sunlight increased considerably (up to 80 mm. Hg). This rise showed a wave-like curve with various degrees of persistency. Appearance of fluid on the skin of Awassi sheep was observed on several occasions.
The threonine requirement of the weanling pig
Authors: Evans R. E. 
Published: March 2009

The L-threonine requirement of the weanling pig is 0·45% of the air-dry food. This level supports as good growth and economy of food conversion and promotes as good retention of nitrogen as higher amounts.It is unlikely, when pigs are fed normal rations, that L-threonine will be the limiting essential amino acid.A comparison in the period 120–180 lb. live weight between diets supplying 0·47 and 0·87% L-lysine, respectively, showed no benefit from feeding the higher amount. It seems uneconomic to feed animal-protein to supply lysine after 1201b. live weight. The requirement can be met at less cost from vegetable sources.In conclusion, the author desires to express his indebtedness to Messrs V. Thurlbourn and R. D. Willis for taking charge of the experimental animals during the N-balance trial. Also to Mr E. A. Porter for his care of the pigs during the growth trial.
The effect of tilth on the emergence of spring oats
Authors: Thow R. F. 
Published: March 2009

1. A survey of commercial crops of spring oats suggested tilth as a major factor affecting emergence.2. In field experiments conducted on clay and sandy soils, the surface tilth was regarded as a population of aggregates characterized by size which was analysed by means of a five-point quadrat. A tilth index was calculated from the data thus obtained. Under the rough tilths on the clay soil emergence and tilth were directly related, but on the sandy soil there was an optimum degree of cultivation, the plots with the finest tilth had been over-cultivated and gave a low rate of emergence (Fig. 2).3. A greenhouse pot experiment examined the effect of a cover above the seed of 21 tilths, of varying proportions of 0·03–0·25 in., 0·25–1·25 in., 1·25–2·25 in. diameter aggregates, the soil below the seed being uniform in all treatments. This confirmed that emergence rates were higher under fine surface tilths than under very rough tilths (Fig. 3). An increase in the proportion of 0·03–0·25 in. fraction increased emergence regularly whereas an increase in the proportion of the 1·25–2·25 in. fraction reduced emergence regularly. The presence of 0·25–1·25 in. aggregates reduced emergence compared with that where 0·03–0·25 in. only were present, but the effect of an increase in the proportion was not regular (Fig. 4).4. A second greenhouse pot experiment compared the effect of 3 tilths above the seed and 2 irrigation treatments. The low emergence rate (58%) caused by a very rough tilth under restricted irrigation was raised to 86% by liberal irrigation.5. From the evidence of both pot experiments it is postulated that a covering tilth above the seed of 25% or more by weight of fine soil (0·03–0·25 in.) and not more than 40% of coarse aggregates (1·25–2·25 in.) will permit a rate of emergence of at least 80%.6. As the fine covering tilths in the pot experiment gave high rates of emergence as compared with rougher tilths, it is suggested that the low rate of emergence, on the sandy soil field experiments, was due to a lack of soil moisture induced by over-cultivation.
Residual value of superphosphate and rock phosphate on an acid soil II. Soil analysis and greenhouse experiments
Authors: Mattingly G. E. G. 
Published: March 2009

1. Analyses and a greenhouse experiment on soils taken from a field experiment to estimate residual values of phosphates were used to show changes in the amount and distribution of residual phosphate in the soil.2. Total and NaHCO2-soluble P were large in the top 0–3 in. of soil after applying superphosphate. Total P was large, but NaHCO3-soluble P much less, where rock phosphate had been applied in the field. Ploughing distributed total and NaHCO3-soluble P more uniformly through the 0–6 in. layer of soil.3. Soil analysis and crop yields in the greenhouse showed that the residual value of equal amounts of P2O5 as rock phosphate and superphosphate, three years after application, were very similar.4. At the end of the field experiment the sand fraction of the soil (2000–75 μ) contained about 80% of the phosphate that was applied as rock phosphate in this particle-size range.