bluuebunny/crossref_metadata_2025_split huggingface dataset:
Flight distance of dairy cows and its relationship to daily routine management procedures and productivity
Authors: UETAKE Katsuji , MORITA Shieru , HOSHIBA Shinji , TANAKA Toshio 
Published: March 2003

ABSTRACTThe objectives of this study were to determine to what extent the flight distance of cows to humans was influenced by sire and management procedures before and after maturity, and whether there was a correlation between the flight distance and productivity on commercial dairy farms. Flight distance of 84 Holstein cows, the stockperson's daily routine management procedures and production performance were recorded repeatedly on eight commercial dairy farms. The management procedures for the animals at the suckling, growing, lactating and dry stages were classified into four categories by degree of tactile interactions between the stockperson and the animal: hand procedures with touch on (category A), nearby (category B) and apart (category C) from the animal, and machinery procedures (category D). There was no apparent sire effect on flight distance (P = 0.08), whereas the flight distance ranged from 1.17 ± 0.86 to 4.47 ± 2.01 m by farm (P < 0.01), and gradually shortened with repetition (P < 0.05). Regression analysis indicated that the length of time of category B at the suckling stage and category B at the dry stage accounted for 37% and 32% of the variation in flight distance, respectively. As for the total time of the four procedure categories, growing stage was the prime predictor of flight distance, which accounted for 36% of the variation. Flight distance tended to correlate with the first calving age (r = 0.66, P = 0.07). These results suggest the importance of non‐producing periods, before maturity and during the dry period, on the subsequent and lifelong advantages of a good relationship between the stockperson and their animals.
Changes in the amount of proteins, glycogen and lipids in porcine oocytes during in vitro meiotic maturation
Authors: NIIMURA Sueo , TAKANO Hiroko , ONISHI Akira , HOSOE Misa 
Published: March 2003

ABSTRACTChanges in the cytoplasmic inclusions during meiotic maturation were histochemically examined in cultured porcine oocytes. The oocytes contained a small amount of protein and glycogen granules throughout the maturation culture, as well as Sudanophilic lipids composed of small, medium and large droplets. Soon after collection, the amount of Sudanophilic lipid droplets of small and medium size was small and there were 167 ± 11.2 large droplets. After being cultured for 22 h, the number of large lipid droplets decreased remarkably, while the number of small and medium ones increased. There were no differences in the number of Sudanophilic lipid droplets of different sizes between ovulated oocytes and the oocytes cultured for 44 h. The oocytes always contained a large amount of neutral fats and lipoids, but not cholesterols. In the oocytes cultured for 22 h with olomoucine, both the resumption of nuclear maturation and the decrease in the size of the Sudanophilic lipid droplets were inhibited. From the present findings, it appears that the change in the size of the Sudanophilic lipid droplets in the cytoplasm of porcine oocytes is closely related to nuclear maturation.
Molecular cloning, nucleotide sequence and characteristics of a xylanase gene (xynA) from Ruminococcus albus 7
Authors: NAKAMURA Mutsumi , NAGAMINE Takafumi , TAKENAKA Akio , AMINOV Rustem I. , OGATA Koretsugu , TAJIMA Kiyoshi , MATSUI Hiroki , BENNO Yoshimi , ITABASHI Hisao 
Published: March 2003

ABSTRACTA 2.6‐kb DNA fragment encoding a xylanase gene (xynA) was cloned from the rumen hemicellulolytic bacterium Ruminococcus albus 7. The deduced primary structure of the protein (XynA) was divided into a signal peptide region and 3 domains. Domain A was identified as a family 11 (G) catalytic domain, but one amino acid residue was replaced by another in an active site signature 1 of family 11. Domain B is a stabilizing domain for the catalytic domains of families 10 and 11. Deletion of domain B reduced stability of the xylanase at high temperature and at high and low pH. Domain B may be useful for protein engineering of xylanase. Domain C has sequence similarity to deacetylases and NodB proteins.
Purification and characterization of an angiotensin I‐converting enzyme inhibitory peptide derived from porcine troponin C
Authors: KATAYAMA Kazunori , TOMATSU Makoto , FUCHU Hidetaka , SUGIYAMA Masaaki , KAWAHARA Satoshi , YAMAUCHI Kiyoshi , KAWAMURA Yukio , MUGURUMA Michio 
Published: March 2003

ABSTRACTTo search for a novel angiotensin I‐converting enzyme (ACE) inhibitory peptide, porcine skeletal troponin was hydrolyzed with pepsin. This hydrolysate showed ACE inhibitory activity, and was applied to various kinds of chromatography to separate an active peptide. Analysis using a protein sequencer identified this peptide as RMLGQTPTK (9mer). This sequence was estimated to occur at the 44–52 position of troponin C, and its 50% inhibitory protein concentration (IC50) was 34 µM. RMLGQTP (7mer), a partial peptide of 9mer, showed activity with an IC50 of 503 µM. RP‐HPLC analysis of a reaction mixture of 9mer and ACE showed that 9mer was slowly hydrolyzed by ACE. On the other hand, 7mer was rapidly hydrolyzed by ACE. Activity of 9mer was reduced as its hydrolysis by ACE proceeded. To estimate the resistance of 9mer to digestive proteases after oral administration, it was reacted with pepsin, α‐chymotrypsin, or trypsin. In each of these reaction mixtures, a significant amount of 9mer remained as a substrate after digestion. Remaining ACE inhibitory activity was close to that of 9mer. These results suggest that 9mer might not be digested after oral administration, because of its relatively high resistance to digestive proteases. Therefore, 9mer might be expected to work well in vivo as an ACE inhibitor.
Methane emissions from wetlands and their relationship with vascular plants: an Arctic example
Authors: Joabsson Anna , Christensen Torben Røjle 
Published: March 2003

AbstractThis paper investigates the relationship between vascular plant production and CH4 emissions from an arctic wet tundra ecosystem in north‐east Greenland. Light intensity was manipulated by shading during three consecutive growing seasons (1998–2000). The shading treatment resulted in lower carbon cycling in the ecosystem as mean seasonal net ecosystem exchange (NEE) decreased from −336 to −196 mg CO2 m−2 h−1 and from −476 to −212 mg CO2 m−2 h−1 in 1999 and 2000, respectively, and total ecosystem respiration decreased from 125 to 94 mg CO2 m−2 h−1 in 1999 and from 409 to 306 mg CO2 m−2 h−1 in 2000. Seasonal mean CH4 emissions in controls and shaded plots were, respectively, 6.5 and 4.5 mg CH4 m−2 h−1 in 1999 and 8.3 and 6.2 mg CH4 m−2 h−1 in 2000. We found that CH4 emission was sensitive to NEE and carbon turnover, and it is reasonable to assume that the correlation was due to a combined effect of vegetative CH4 transport and substrate quality coupled to vascular plant production. Total above‐ground biomass was correlated to mean seasonal CH4 emission, but separation into species showed that plant‐mediated CH4 transport was highly species dependent. Potential CH4 production peaked at the same depth as maximum root density (5–15 cm) and treatment differences further suggest that substrate quality was negatively affected by decreased NEE in the shaded plots. The concentration of dissolved CH4 decreased in the control plots as the growing season progressed while it was relatively stable in the shaded plots. This suggests that a progressively better developed root system in the controls increased the capacity to transport CH4 from the soil to the atmosphere. In conclusion, vascular plant photosynthetic rate and subsequent allocation of recently fixed carbon to below‐ground structures seemed to influence both vegetative CH4 transport and substrate quality.
Carbon dynamics within agricultural and native sites in the loess region of western Iowa
Authors: Manies K. L. , Harden J. W. , Kramer L. , Parton W. J. 
Published: March 2003

AbstractIn order to quantify the historical changes in carbon storage that result from agricultural conversion, this study compared the carbon dynamics of two sites in the loess region of Iowa: a native prairie and a cropland. Field data were obtained to determine present‐day carbon storage and its variability within a landscape (a stable ridgetop vs. eroding upper‐midslope vs. depositional lower slope). Models were used to recreate the historical carbon budget of these sites and determine the cropland's potential to be a net CO2 source or sink, relative to the atmosphere.Regardless of slope position, the cropland site contains approximately half the amount of carbon as prairie. Variability in soil carbon storage within a site as a consequence of slope position is as large or larger (variations of 200–300%) than temporal variation (∼200% at all slope positions). The most extreme difference in soil carbon storage between the cropland and prairie sites is found in the soil at the upper‐midslope, which is the area of greatest erosion. The models estimate that 93–172% of the carbon in the original topsoil has been lost from the cropland's eroding midslope. Much of this carbon is derived from deeper soil horizons. Either a small sink or strong source of carbon to the atmosphere is created, depending on the fate of the eroded sediment and its associated carbon.
Response of wheat canopy CO2 and water gas‐exchange to soil water content under ambient and elevated CO2
Authors: Mitchell Rowan A. C. , Mitchell Valerie J. , Lawlor David W. 
Published: March 2003

AbstractThe nature of the interaction between drought and elevated CO2 partial pressure (pCa) is critically important for the effects of global change on crops. Some crop models assume that the relative responses of transpiration and photosynthesis to soil water deficit are unaltered by elevated pCa, while others predict decreased sensitivity to drought at elevated pCa. These assumptions were tested by measuring canopy photosynthesis and transpiration in spring wheat (cv. Minaret) stands grown in boxes with 100 L rooting volume. Plants were grown under controlled environments with constant light (300 µmol m−2 s−1) at ambient (36 Pa) or elevated (68 Pa) pCa and were well watered throughout growth or had a controlled decline in soil water starting at ear emergence. Drought decreased final aboveground biomass (−15%) and grain yield (−19%) while elevated pCa increased biomass (+24%) and grain yield (+29%) and there was no significant interaction. Elevated pCa increased canopy photosynthesis by 15% on average for both water regimes and increased dark respiration per unit ground area in well‐watered plants, but not drought‐grown ones. Canopy transpiration and photosynthesis were decreased in drought‐grown plants relative to well‐watered plants after about 20–25 days from the start of the drought. Elevated pCa decreased transpiration only slightly during drought, but canopy photosynthesis continued to be stimulated so that net growth per unit water transpired increased by 21%. The effect of drought on canopy photosynthesis was not the consequence of a loss of photosynthetic capacity initially, as photosynthesis continued to be stimulated proportionately by a fixed increase in irradiance. Drought began to decrease canopy transpiration below a relative plant‐available soil water content of 0.6 and canopy photosynthesis and growth below 0.4. The shape of these responses were unaffected by pCa, supporting the simple assumption used in some models that they are independent of pCa.
Soil carbon stocks and land use change: a meta analysis
Authors: Guo L. B. , Gifford R. M. 
Published: March 2003

AbstractThe effects of land use change on soil carbon stocks are of concern in the context of international policy agendas on greenhouse gas emissions mitigation. This paper reviews the literature for the influence of land use changes on soil C stocks and reports the results of a meta analysis of these data from 74 publications. The meta analysis indicates that soil C stocks decline after land use changes from pasture to plantation (−10%), native forest to plantation (−13%), native forest to crop (−42%), and pasture to crop (−59%). Soil C stocks increase after land use changes from native forest to pasture (+ 8%), crop to pasture (+ 19%), crop to plantation (+ 18%), and crop to secondary forest (+ 53%). Wherever one of the land use changes decreased soil C, the reverse process usually increased soil carbon andvice versa. As the quantity of available data is not large and the methodologies used are diverse, the conclusions drawn must be regarded as working hypotheses from which to design future targeted investigations that broaden the database. Within some land use changes there were, however, sufficient examples to explore the role of other factors contributing to the above conclusions. One outcome of the meta analysis, especially worthy of further investigation in the context of carbon sink strategies for greenhouse gas mitigation, is that broadleaf tree plantations placed onto prior native forest or pastures did not affect soil C stocks whereas pine plantations reduced soil C stocks by 12–15%.
Coaction of DNA topoisomerase IIIα and a RecQ homologue during the germ‐line mitosis in Caenorhabditis elegans
Authors: Kim You‐Chan , Lee Min‐Ho , Ryu Sung‐Shin , Kim Ji‐Hoon , Koo Hyeon‐Sook 
Published: March 2003

AbstractBackground: Among the four RecQ homologues predicted from the Caenorhabditis elegans genomic DNA sequence, T04A11.6 is most similar to Bloom syndrome’s protein in humans. To investigate a possible interaction of the protein with topoisomerase IIIα (TOP3α), as observed between TOP3 and RecQ homologues in yeast and human, the top3α gene expression was suppressed by RNA interference (RNAi) in the him‐6(e1104) C. elegans strain which is mutated in T04A11.6 (F. Mueller & C. Wicky, personal communication).Results: Germ cells in the gonads of the progeny him‐6(e1104);top3α(RNAi) showed severe chromosomal abnormalities and were arrested during mitosis with a subsequent failure in meiotic entry. Most of the aberrant chromosomes were stained by the TUNEL assay but not by the SYTO12 dye, suggesting extensive DNA breaks not associated with apoptosis. The phenotypes in the germ cells of him‐6(e1104);top3α(RNAi) were also observed in the progeny produced by double RNA interference of the top3α and him‐6 gene expression, though at a reduced level. The over‐expressed TOP3α and Him‐6 proteins showed specific physical interaction in vitro, in agreement with the genetic interaction in C. elegans.Conclusion: In C. elegans, TOP3α and the RecQ homologue (T04A11.6) contribute to genome stability during germ‐line mitosis, probably by acting in a complex.
Neurohormonal influences on maintenance and reversal of two‐kidney one‐clip renal hypertension
Authors: NystrÖm H. C. , Jia J. , Johansson M. , Lambert G. , BergstrÖm G. 
Published: March 2003

AbstractThe factors involved in maintenance and reversal of mean arterial blood pressure (MAP) in the chronic two‐kidney one‐clip hypertensive rat (2K1C‐RHR) are still debated. The reduction in MAP after reversal of 2K1C hypertension has been ascribed either to release of a renal medullary depressor hormone (RMDH) or suppression of the renin–angiotensin and/or sympathetic nervous system. We studied in conscious rats: (i) The effects of angiotensin II receptor blockade (ARB; candesartan), sympathetic blockade (propranolol and phentolamine) or a combination on MAP in 6‐week long 2K1C‐RHR; (ii) The effects of reversal of 2K1C hypertension by removal of the constricting clip (unclipping, UC) or nephrectomy (Nx) on MAP, plasma renin activity (PRA) and noradrenaline (NA) spillover rates. The results show that: (i) MAP in the 2K1C‐RHR was almost normalized by ARB but not significantly affected by the sympathetic blockade. The combination was not more effective than ARB alone; (ii) UC and Nx reduced MAP in 2K1C to similar levels as ARB. No significant changes in PRA or catecholamines could be detected in UC and Nx groups. We conclude that hypertension in 2K1C‐RHR is maintained by the renin–angiotensin system without much contribution from the sympathetic nervous system. Furthermore, we found no evidence that UC of our model of 2K1C was associated with a generalized decrease in sympathetic tone or substantial release of RMDH from the unclipped kidney. Thus, we conclude that in the present model of 2K1C, both maintenance and reversal of hypertension are controlled by the renin–angiotensin system.
Clenbuterol induces expression of multiple myosin heavy chain isoforms in rat soleus fibres
Authors: Oishi Y. , Imoto K. , Ogata T. , Taniguchi K. , Matsumoto H. , Roy R. R. 
Published: March 2003

ABSTRACTClenbuterol, a β2‐agonist, administration results in hypertrophy of fast fibres and an increase in the fast myosin heavy chain (MHC) composition of both fast and slow muscles. The present study was designed to determine the phenotypic response at the single fibre level. Clenbuterol was added to the drinking water (30 mg L−1) of adult male Wistar rats for 4 weeks. Single fibres from the soleus muscle of control (10 rats; 555 fibres) and clenbuterol‐treated (10 rats; 577 fibres) were dissected and their MHC isoform composition was determined using sodium dodecyl sulphate–polyacrylamide gel electrophoresis analysis. Body, heart, and soleus weights were 9, 24, and 27% higher in clenbuterol‐treated than control rats. The mean cross‐sectional areas of fast and slow/fast hybrid fibres were ∼64 and ∼74% larger in the clenbuterol‐treated than control rats, whereas the size of the slow fibres were similar in the two groups. Fibres from control soleus showed three MHC patterns: pure type I (84%), pure type IIa (4%), and type I + IIa (12%) MHC. Some fibres from clenbuterol‐treated soleus showed a de novo expression of type IIx MHC resulting in the following fibre type proportions: pure type I (62%), pure type IIa (2%), type I + IIa (26%), type I + IIa + IIx (6%), and type IIa + IIx (1%). In those fibres containing multiple MHCs, there was a shift towards the faster MHC isoforms after clenbuterol treatment. These data indicate that clenbuterol results in muscle fibre hypertrophy, stimulates a de novo expression of type IIx MHC and increases the percentage of fibres containing multiple MHC isoforms in the rat soleus muscle. These phenotypic changes at the single fibre level are consistent with a clenbuterol‐related shift in the functional properties of the soleus towards those observed in a faster muscle.
Distribution of monocarboxylate transporter isoforms MCT1, MCT2 and MCT4 in porcine muscles
Authors: Sepponen K. , Koho N. , Puolanne E. , Ruusunen M. , Pösö A. R. 
Published: March 2003

Abstract Aim:  Monocarboxylate transporters (MCT), which cotransport lactate anions and protons across cell membranes, are important for regulation of muscle pH. We measured amounts of MCT1, MCT2 and MCT4 by immunoblotting in five different porcine muscles, to study MCT‐isoform distribution both in oxidative and highly glycolytic muscles.Methods:  Samples from the longissimus dorsi, gluteus superficialis, semimembranosus, infraspinatus and masseter were taken from 18 slaughtered pigs.Results:  Oxidative capacity, estimated on the basis of the activities of lactate dehydrogenase (LDH), citrate synthase (CS) and 3‐OH‐acyl‐CoA dehydrogenase (HAD), was highest in the infraspinatus and masseter, and was very low in the gluteus, semimembranosus and longissimus dorsi. In all muscles, the amount of MCT1 was small but variable. The amount of MCT2 was more abundant in the glycolytic than in the oxidative muscles, while MCT4 was found in equal amounts in all muscles. MCT2, but not MCT4, correlated negatively with CS and HAD.Conclusions:  The results together with measured concentrations of lactate suggest that MCT2 may function as the housekeeping lactate transporter, preventing acidification especially in highly glycolytic muscles in which the capacity to oxidize lactate is low. The results also support the view that, as in other species, MCT4 would be important at high lactate concentrations that occur during stress.
Kinetic model of osmosis through semipermeable and solute‐permeable membranes
Authors: Kiil F. 
Published: March 2003

AbstractThe gas analogy of the van't Hoff equation for osmotic pressure Δπ = RT/, whereRis gas constant,Tabsolute temperature andmole volume of water, remained unexplained for a century because of a few misconceptions: (1) Use of supported membranes prevented the recognition that osmotic forces exert no effect on the solid membrane. During osmotic flow frictional force of solvent within membrane channels equals osmotic kinetic force π at the interface against the solution containing impermeant solute. (2) Retrograde diffusion of water is much less than osmotic flow even when dxin the gradient dc/dxapproaches zero. (3) The gas analogy was thought to be accidental. Actually, the internal kinetic pressure isP = RT/, because intermolecular forces cancel out at the liquid interface, just as within a gas. The kinetic osmotic pressure is the difference in solvent pressure across the interface: π = RT/–(RT/)X1 = (RT/)X2, where X1and X2are the mole fractions of water and impermeant solute, respectively. Integration gives π = –(RT/)lnX1, identical to the thermodynamic equation. This equation is correct up to 25 atmospheres, and up to 180 atmospheres by assuming that a sucrose molecule binds 4 and a glycerol molecule 2.5 water molecules. For solute‐permeable membranes, the reflection coefficient σ can be calculated by formulas proposed for ultrafiltration. Because the fraction (1–σ) of solute concentration behaves as solvent, osmosis may well proceed against the chemical potential gradient for water. The analogy to an ideal gas applies because π = –(RT/)lnX1is the small difference between enormous internal solvent pressures.
Sympathetic nerve activity in hypotension and orthostatic intolerance
Authors: Mano T. , Iwase S. 
Published: March 2003

AbstractAim:  The present paper reviews how changes in sympathetic nerve activity are related to hypotensive episodes and orthostatic intolerance in humans.Results:  It has been well documented that sympathetic neural traffic to skeletal muscles (muscle sympathetic nerve activity; MSNA) plays an essential role in maintaining blood pressure homeostasis mainly through baroreflex. The MSNA responded to gravitational loading from the head to the leg (+Gz) during passive head‐up tilt (HUT). Patients who suffered from orthostatic hypotension with or without syncope were classified into at least two groups; low and high responders of MSNA to orthostatic loading. The typical examples belonging to the former group were patients of multiple system atrophy who had very low basal sympathetic outflow to muscle which responded extremely poorly to HUT. Patients of multiple system atrophy presented also postprandial hypotension in which muscle sympathetic response to oral glucose administration was absent. The latter group was represented by subjects who manifested vasovagal syncope with normal or even higher muscle sympathetic response to HUT, which was suddenly withdrawn concomitantly with bradycardia and hypotension. Similar withdrawal of sympathetic nerve traffic to muscle was encounterd in a rare case of idiopathic non‐orthostatic episodic hypotension which accompanied bradycardia. The MSNA was suppressed by short‐term exposure to microgravity but was enhanced after long‐term exposure to microgravity. Orthostatic intolerance after long‐term exposure to microgravity was related to progressive reduction of muscle sympathetic response to orthostatic loading with impaired arterial baroreflex.Conclusion:  It is concluded that hypotensive episodes are closely related to poor or lack of muscle sympathetic outflow, but may depend on various neural mechanisms to induce it.