bluuebunny/crossref_metadata_2025_split huggingface dataset:
Effect of muscle‐derived stem cells on the restoration of corpora cavernosa smooth muscle and erectile function in the aged rat
Authors: Nolazco Gaby , Kovanecz Istvan , Vernet Dolores , Gelfand Robert A. , Tsao James , Ferrini Monica G. , Magee Thomas , Rajfer Jacob , Gonzalez‐Cadavid Nestor F. 
Published: February 2008

OBJECTIVETo determine whether skeletal muscle‐derived stem cells (MDSCs) convert into smooth muscle cells (SMCs) bothin vitroandin vivo, and in so doing ameliorate the erectile dysfunction (ED) of aged rats, and whether endogenous stem cells are present in the rat corpora cavernosa.MATERIALS AND METHODSMDSCs were obtained from mouse muscle, and shown by immunocytochemistry for α‐smooth muscle actin (αSMA) to originatein vitroin myofibroblasts and SMCs, discriminating SMCs by calponin 1 expression.In vivothese MDSCs, labelled with 4′,6‐diamidino‐2‐phenylindole, were implanted into the corpora cavernosa of young adult (5‐month old) and aged (20‐month old) rats for 2 and 4 weeks. Histological changes were assessed by immunohistochemistry and quantitative Western blot. Functional changes were determined by electrical field stimulation (EFS) of the cavernosal nerve.RESULTSThe exogenous cells replicated and converted into SMCs, as shown in corporal tissue sections by confocal immunofluorescence microscopy for proliferating cell nuclear antigen (PCNA), αSMA, and smoothelin, and also by Western blot for αSMA and PCNA. MDSC differentiation was confirmed by the activation of the αSMA promoter‐linked β‐galactosidase in transfected cells, bothin vitroand after implantation in the corpora. Putative endogenous stem cells were shown in corporal tissue sections and Western blots by detecting CD34 and a possible Sca1 variant. EFS showed that implanted MDSCs raised in aged rats the maximal intracavernosal pressure/mean arterial pressure levels above (2 weeks) or up to (4 weeks) those of young adult rats.CONCLUSIONSMDSCs implanted into the corpora cavernosa of aged rats converted into SMCs and corrected ED, and endogenous cells expressing stem cell markers were also found in untreated tissue. This suggests that exogenous stem cell implantation and/or endogenous stem cell modulation might be viable therapeutic approaches for ageing‐related ED.
The assessment of oxidative stress in infertile patients with varicocele
Authors: Sakamoto Yuichi , Ishikawa Tomomoto , Kondo Yutaka , Yamaguchi Kohei , Fujisawa Masato 
Published: February 2008

OBJECTIVESTo assess oxidative stress markers, antioxidant capacity and cytokines in seminal plasma from infertile patients with varicocele, and to investigate seminal oxidative status and sperm DNA damage after varicocelectomy.PATIENTS, SUBJECTS AND METHODSThe records were retrospectively evaluated for 28 azoospermic, 30 oligospermic (15 with varicocele and 15 without) and 30 patients with normal semen characteristics (15 with varicocele and 15 without). The mean (sd) age of the men was 32.4 (5.6) years; all men with varicocele had a unilateral or bilateral microsurgical subinguinal varicocelectomy. The level of nitric oxide (NO), 8‐hydroxy‐2′‐deoxyguanosine (8‐OHdG), hexanoyl‐lysine (HEL), superoxide dismutase (SOD) activity, interleukin (IL)‐6, IL‐8 and tumour necrosis factor‐α in seminal plasma were measured. In addition, sperm DNA fragmentation was analysed before and 6 months after varicocelectomy.RESULTSAzoospermic and oligospermic patients had a significantly higher HEL concentration and SOD activity in seminal plasma; those with varicocele had a significantly higher NO, HEL, and SOD activity in seminal plasma. There was a significant increase in sperm concentration and reduction in NO, HEL, 8‐OHdG level and SOD activity after varicocelectomy. Oligospermic patients with varicocele had a significantly higher IL‐6 level in seminal plasma, and there was a significant reduction after varicocelectomy. The percentage of apoptosis‐positive sperm decreased significantly after varicocelectomy.CONCLUSIONSThis study indicates that the seminal plasma of patients with varicocele is under excessive oxidative stress, and partly even in patients with normospermia, and that varicocelectomy reduces oxidative stress in seminal plasma and ameliorates sperm DNA damage.
Sperm DNA fragmentation in subfertile men: the effect on the outcome of intracytoplasmic sperm injection and correlation with sperm variables
Authors: Nicopoullos James D.M. , Gilling‐Smith Carole , Almeida Paula A. , Homa Sheryl , Norman‐Taylor Julian Q. , Ramsay Jonathan W.A. 
Published: February 2008

OBJECTIVETo present the first UK data on sperm DNA fragmentation levels in subfertile men and fertile controls, the correlation with semen variables, and to assess the effect on the outcome of intracytoplasmic sperm injection (ICSI).PATIENTS, SUBJECTS AND METHODSIn all, 56 subfertile men undergoing ICSI (28 with positive and 28 with a negative outcome for paternity) and 10 control fertile semen donors were recruited. The sperm DNA fragmentation index (DFI) was assessed on raw pre‐preparation samples using the sperm chromatin structure assay. A mean of 5212 sperm were analysed per sample and DFI data are presented by fertility status, ICSI outcome and correlated with semen variables (assessed using World Health Organisation criteria).RESULTSTotal DFI was significantly higher in subfertile men than in fertile controls (mean and median of 22.8% and 17.0% vs 8.4% and 5.0%; P < 0.001), as was the proportion of both moderate DFI (16.4% and 13.0% vs 6.4% and 4.0%; P = 0.001) and high DFI (6.2% and 6.1 vs 2.0% and 1.0%; P = 0.01). This difference remained significant when the control men were compared only with the subfertile men with successful paternity. There was no significant difference in DFI in the subfertile men when analysed by ICSI outcome (mean and median of 24.5% and 17.0% vs 22.3% and 21.0% for successful and unsuccessful cycles, respectively; P = 0.94). There was a positive statistically significant correlation (r = 0.37; P = 0.02) between the DFI and sperm morphology.CONCLUSIONSThis study confirms a relationship between male subfertility and sperm DFI; we discuss the correct role for genetic testing of sperm in the evaluation of subfertile men. Although DNA fragmentation data might help to decide a suitable treatment, once it is decided to proceed with ICSI, DFI levels have no effect on the outcome.
Androgens and bladder outlet obstruction: a correlation with pressure‐flow variables in a preliminary study
Authors: Koritsiadis George , Stravodimos Konstantinos , Mitropoulos Dionisios , Doumanis Grigorios , Fokitis Ioannis , Koritsiadis Sotirios , Constantinides Constantinos 
Published: February 2008

OBJECTIVESTo determine the relationship between androgens, lower urinary tract symptoms (LUTS) and urodynamic variables of bladder outlet obstruction (BOO) in patients with LUTS/benign prostatic hyperplasia (BPH), as androgens are important in the pathogenesis of LUTS.PATIENTS AND METHODSTwenty‐five men with symptomatic BPH were enrolled in the study and had a complete urodynamic investigation, establishing BOO. Age, prostate‐specific antigen level, prostate volume and postvoid residual volume were recorded and the International Prostate Symptom Score (IPSS) was estimated. Detrusor pressure at maximum flow (PdetQmax), at urethral closure (PdetCl, the pressure at the end of urinary flow) and maximum detrusor pressure (Pdetmax) was recorded, while detrusor overactivity (DO) was noted when present. Blood samples were collected to measure total testosterone (T), and free T (FT) was calculated. Patients were grouped according to FT levels as low (<72 pg/mL) and normal (FT ≥72 pg/mL).RESULTSTen patients had a low FT level, with a mean (sd) of 54.3 (16.5) pg/mL, and 15 a normal level of FT, of 90.5 (11) pg/mL. FT was negatively correlated with PdetCl, and PdetQmax; the mean PdetCl and PdetQmax differed significantly between patients with low and normal FT levels. Fourteen patients had DO and they had significantly lower levels of FT than those with no DO. All patients with a FT level of <60 pg/mL had DO, and the presence of instability differed significantly from the rest of the group.CONCLUSIONSLow T levels in clinical BOO correlated negatively with PdetCl and PdetQmax, while promoting DO. Androgen seems to have an ameliorating role in lower urinary tract function.
REDISTRIBUTION AND FREE TRADE IN AGRICULTURE: ARE THEY COMPLEMENTARY?
Authors: Sarkar Abhirup 
Published: February 2008

ABSTRACTThe purpose of the paper is to look at the welfare effects of trade in agricultural goods in a less developed country where the agricultural market is controlled by a handful of large farmers. It is shown that the success of trade reform depends on the distribution of output between large and small farmers and the success of land reform leading to redistribution from the large to the small farmers depends on trade reform. In other words, if undertaken in isolation, each reform might lead to a fall in welfare, but if jointly undertaken, they will lead to an increase in welfare. Thus the two reforms are complementary.
THE OPTIMAL LIFETIME OF ASSETS UNDER UNCERTAINTY IN THE RATE OF EMBODIED TECHNICAL CHANGE
Authors: Bitros George C. 
Published: February 2008

ABSTRACTI investigate the effects of uncertainty regarding the rate of embodied technical change on the lifetime of assets using a model where: (1) technical change increases continuously the productivity of producers’ durables, (2) potential competition induces firms to pass all benefits from productivity improvements to consumers, and (3) the mean and the variance are considered sufficient statistics to describe the probability distribution of technological change. I find that in general this type of uncertainty shortens the optimal lifetime of assets. However, the robustness of the results under alternative specifications of the probability distribution of technological change remains an open question.
BALANCE OF PAYMENTS‐CONSTRAINED GROWTH IN DEVELOPING COUNTRIES: A THEORETICAL PERSPECTIVE
Authors: Alleyne Dillon , Francis Alfred A. 
Published: February 2008

ABSTRACTThe paper clarifies some issues raised in the basic model of balance of payments‐constrained growth due to Thirlwall and later extensions by Thirlwall and Hussain and Moreno‐Brid. The model is also adapted to include both interest payments and net transfers. The latter variable has become very important to many developing countries and brings a new dimension to the analysis. Very importantly, net transfers are positively related to foreign income and negatively related to domestic income. Thus, the paper accounts for dynamic feedback effects, between net transfers, domestic and world income.
Cellulose biosynthesis and deposition in higher plants
Authors: Taylor Neil G. 
Published: February 2008

SummaryThe plant cell wall is central to plant development. Cellulose is a major component of plant cell walls, and is the world's most abundant biopolymer. Cellulose contains apparently simple linear chains of glucose residues, but these chains aggregate to form immensely strong microfibrils. It is the physical properties of these microfibrils that, when laid down in an organized manner, are responsible for both oriented cell elongation during plant growth and the strength required to maintain an upright growth habit. Despite the importance of cellulose, only recently have we started to unravel details of its synthesis. Mutational analysis has allowed us to identify some of the proteins involved in its synthesis at the plasma membrane, and to define a set of cellulose synthase enzymes essential for cellulose synthesis. These proteins are organized into a very large plasma membrane‐localized protein complex. The way in which this protein complex is regulated and directed is central in depositing cellulose microfibrils in the wall in the correct orientation, which is essential for directional cell growth. Recent developments have given us clues as to how cellulose synthesis and deposition is regulated, an understanding of which is essential if we are to manipulate cell wall composition.

Contents

Summary
1

I.
Introduction
2

II.
Structure of cellulose
2

III.
Cellulose synthase
2

IV.
Mutations affecting cellulose synthesis
4

V.
Cellulose synthase complex assembly
6

VI.
Transcriptomic approaches to identify genes involved in cellulose synthesis
7

VII.
Purification of the cellulose synthase complex
8

VIII.
Regulation of cellulose synthesis
8

IX.
Feedback responses to cell wall defects
9

X.
Regulation of orientation of cellulose deposition
10

XI.
Cellulose as a source of renewable energy
10

XII.
Conclusions
11

Acknowledgements
11

References
11
Effects of ploughing frequency and compost on soil aggregate stability in a cotton–maize (Gossypium hirsutum‐Zea mays) rotation in Burkina Faso
Authors: Ouattara K. , Ouattara B. , Nyberg G. , Sédogo M. P. , Malmer A. 
Published: February 2008

AbstractCropping systems have a strong influence on soil structural characteristics, including aggregate stability. An experiment combining compost (Co) and mineral fertilizer inputs with different tillage frequencies was conducted in a cotton–maize rotation system on two soil types (Lixisol and Luvisol) in Burkina Faso. The objective was to investigate an alternative soil fertility management regime that protects soil structure for cotton and maize production. We tested the hypothesis that organic fertilizer applications and reduced ploughing frequency can improve aggregate stability. The effects of reduced tillage (RT; ox‐ploughing/hand hoe scarifying the next year) and annual ox‐ploughing (AP) combined with Co and no compost (nCo) applications on the stability of soil aggregates subjected to wet sieving, were assessed. In the second year of the experiment (maize), the macroaggregate stability in the RT plots was 87% higher than in the AP plots on the Lixisol, 26% higher on the Luvisol. In the third year (cotton) the difference in treatment effects was less. The treatments influenced macroaggregate stability in the year of scarification, and the microaggregate stability in the year they were ploughed. We concluded that a soil management regime, with ploughing only every second year and with compost as well as mineral fertilizer inputs, is appropriate to replace the common practice of annual ploughing with application of mineral fertilizers in this cotton–maize cropping system.
Do elevated soil concentrations of metals affect the diversity and activity of soil invertebrates in the long‐term?
Authors: Creamer R. E. , Rimmer D. L. , Black H. I. J. 
Published: February 2008

AbstractThis study aimed to elucidate the response of diversity and activity of soil invertebrates to elevated soil metal concentrations that were a result of sewage sludge application. Field sampling of soil invertebrates was carried out from 2002 to 2004 at an experimental site established in 1982 to test the effects on crop production of metal contamination from sewage sludge applications with elevated concentrations of zinc (Zn), copper (Cu) and nickel (Ni) with certain treatments exceeding the current UK statutory limits for the safe use of sludge on land. At metal concentrations within the limits, none of the invertebrates sampled showed adverse effects on their abundance or overall community diversity (from Shannon–Weiner index). At concentrations above the limits, individual taxa showed sensitivity to different metals, but overall diversity was not affected. Earthworm abundance was significantly reduced at total Cu concentrations at and above 176 mg kg−1, while nematode and enchytraeid abundances were sensitive to Cu and high Zn concentrations. Correspondingly, litter decomposition was lower in Zn and Cu treatments although there was no direct relationship between decomposition and soil invertebrate abundance or diversity. Such enduring changes in both soil biodiversity and biological activity around the current UK regulatory limits warrant further investigation to determine whether they indicate detrimental damage to soil functioning over the long‐term.
Methods for estimating types of soil organic carbon and their application to surveys of UK urban areas
Authors: Rawlins B. G. , Vane C. H. , Kim A. W. , Tye A. M. , Kemp S. J. , Bellamy P. H. 
Published: February 2008

AbstractThe occurrence of substantial quantities of black carbon (BC) in urban soil due to local dispersal following incomplete combustion of fossil fuel complicates the determination of labile soil organic carbon (SOC). Estimates of SOC content were made from loss on ignition (LOI) analyses undertaken on samples (0–15 cm depth) from comprehensive soil geochemical surveys of three UK urban areas. We randomly selected 10 samples from each decile of the LOI distribution for each of the surveys of Coventry (n = 808), Stoke‐on‐Trent (n = 737) and Glasgow (n = 1382) to investigate the proportions of labile SOC and BC. We determined their total organic carbon (TOC) and BC contents, and by difference the labile SOC content, and investigated the linear relationship of the latter with SOC estimates based on LOI analyses. There was no evidence for a difference in the slope of the regression for the three urban areas. We then used a linear regression of labile SOC based on LOI analyses (r2 = 0.81) to predict labile SOC for all survey samples from the three urban areas. We attribute the significantly higher median BC concentrations in Glasgow (1.77%, compared with 0.46 and 0.59% in Coventry and Stoke‐on‐Trent) to greater dispersal of coal ash across the former. An analysis of the 30 samples showed that LOI at 450 °C accounts for a consistent proportion of BC in each sample (r2 = 0.97). Differences between TOC (combustion at 1050 °C after removal of inorganic carbon) and an LOI estimate of SOC may be a cost‐effective method for estimation of BC. Previous approaches to estimation of urban SOC contents based on half the mean SOC content of the equivalent associations under pasture, underestimate the empirical mean value.
Assessing scale effects on modelled soil organic carbon contents as a result of land use change in Belgium
Authors: Dendoncker N. , Van Wesemael B. , Smith P. , Lettens S. , Roelandt C. , Rounsevell M. 
Published: February 2008

AbstractThis paper explores the influence of spatial scale on modelled projections of soil organic carbon (SOC) content. The effect of land use change (LUC) on future SOC stocks was estimated using the Rothamsted Carbon model for a small area of southern Belgium. The study assumed no management change and used a single climate change scenario. Three model experiments were used to identify how data scale affects predicted SOC stocks: (i) using European LUC datasets at a resolution of 10′ and assuming equal distribution of change within the study area, (ii) using more accurate regional data aggregated to the 10’ resolution, and (iii) using the regional data at a spatial resolution of 250 m. The results show that using coarse resolution (10′) data is inappropriate when modelling SOC changes in the study area as only the methods using precise data predict a change in SOC stocks similar to those reported in the literature. This is largely because of differences in model parameterisation. However, precisely locating LUC does not significantly affect the results. The model, using either pan‐European or region‐specific precise data predicts an average SOC increase of 1 t C ha−1 (1990–2050), mainly resulting from afforestation of 13% of agricultural land.
A critical examination of some common field tests to assess the acid‐sulphate condition in soils
Authors: Vegas‐Vilarrúbia T. , Baritto F. , Meleán G. 
Published: February 2008

AbstractAcid‐sulphate soils are of major environmental concern in many wetlands. Severe acidification episodes have occurred worldwide because of the oxidation of iron sulphides to sulphuric acid by human activities, and diverse techniques have been set up to determine the presence of acid‐sulphate soils. This paper evaluates the usefulness of four common easy‐to‐apply field survey tests for potential acid‐sulphate diagnosis in some Histosols and Entisols in wetlands: incomplete oxidation by fast air‐drying, incubation, fast oxidation with hydrogen peroxide, and the indirect determination of sulphide with lead acetate. Samples of 227 surface‐organic and underlying mineral soils of poorly drained Histosols and Entisols of the Orinoco river delta plain were tested. Results showed that for highly organic samples the interpretation of results obtained from the acid‐sulphate soil tests may be misleading, because they cannot be unambiguously related to the production of sulphuric acid derived from pyrite oxidation. Mineral samples yielded more reliable results. The incomplete oxidation by fast air‐drying test did not induce significant acidification either in organic or in mineral samples; the final pH values were dependent on the original pH values. The fast oxidation with hydrogen peroxide test was effective with mineral samples. During the incubation test, the slower rate of pH decrease and the final values obtained with the organic samples suggested retardation in the rate and amount of acid generation by pyrite oxidation because of the concurrent oxygen consumption by organic matter and bacterial activity. The indirect determination of sulphide with lead acetate yielded only qualitative results in organic samples, but worked well in mineral samples, indicating a higher content of pyrite intermediates. Effective estimation of the actual presence and potential for acidification of soil is important, in order to avoid excessive or inappropriate amelioration techniques to prevent acid production.
Spatial patterns and effects of soil organic carbon on grain productivity assessment in China
Authors: Ye L. , Tang H. , Zhu J. , Verdoodt A. , Van Ranst E. 
Published: February 2008

AbstractIn this paper, we present an assessment of the content and effects of cropland soil organic carbon (SOC) on grain productivity at the national scale in China using a Web‐based Land Evaluation System. Homogeneous 5 km × 5 km grid data sets of climate, crop, soil and management parameters were created and grain production in 2005 was simulated. Attempts were made to incorporate SOC into the land evaluation procedure and to quantify the potential effects of SOC deficiency on grain productivity. Results were statistically analysed and the modelling approach was validated. National cropland SOC maps were generated. At the national scale, the cropland SOC content averaged 1.20, 0.58, 0.41, 0.31 and 0.26% for the five 20‐cm sections consecutively from the surface downwards. At the regional scale it tended to decline slightly from northeast (1.63%) to southwest (1.11%). On average, 64% of grain yield was lost due to SOC deficiency for the humid provinces and 7% for the arid and sub‐arid ones. Soil management options are suggested based on the simulation results.