bluuebunny/crossref_metadata_2025_split huggingface dataset:
Gradients in vegetation cover, structure and species richness of Nama‐Karoo shrublands in relation to distance from livestock watering points
Authors: TODD SIMON W. 
Published: March 2006

Summary

Gradients of animal impact known as piospheres tend to develop around artificial watering points, particularly in arid zones. Such grazing gradients represent a potential opportunity for differentiating the long‐term effects of livestock activity from other environmental patterns. In this study, the impact of watering point provision on the plant cover, species richness and community structure of Karoo shrublands, South Africa, was investigated in the context of the evolutionary history and current grazing management practices of the region.
The impacts of watering point provision were investigated by sampling plant cover and composition along transects placed at set distances, ranging from 10 m to 2200 m, from 11 watering points.
Karoo vegetation cover and structure are relatively resilient to livestock grazing. Karoo plant diversity, as measured by species richness, evenness and dominance, was not as resilient. Twice as many species decreased as increased near watering points. The majority of species that decreased were regarded as being highly palatable to livestock. Heavy grazing, leading to death or repeated reproductive failure, is the most likely mechanism leading to the decline of such species.
The highly disturbed area immediately adjacent to watering points was dominated by forbs and contained a large proportion of alien species. Adjacent to this was a zone dominated by widespread shrub species of medium to low palatability. Areas most distant from watering points contained a greater proportion of species known to be highly palatable to livestock. The ability of dominant Karoo shrubs to tolerate heavy grazing may have allowed rangeland managers to maintain stocking rates above that which can be tolerated by the majority of species but which are supported by a minority of grazing‐tolerant species.
Synthesis and applications. Highly palatable species are more abundant in areas distant from water points. Larger paddocks therefore provide a refuge for sensitive species that might otherwise be lost from the rangeland as a whole. Species that tend to occur away from watering points represent potentially useful indicators of grazing pressure. The use of these species as indicators of rangeland condition among landowners should be promoted.
To graze or not to graze? Sheep, voles, forestry and nature conservation in the British uplands
Authors: EVANS DARREN M. , REDPATH STEPHEN M. , ELSTON DAVID A. , EVANS SHARON A. , MITCHELL RUTH J. , DENNIS PETER 
Published: March 2006

Summary

The British uplands are internationally important for their unique plant and bird communities. They have considerable economic, nature conservation, landscape, aesthetic and tourism‐related value and as a result are under a variety of different pressures, most notably from sheep farming, shooting interests, commercial forestry and conservation interests.
In order to optimize biodiversity in the uplands, the challenge is to find how to balance the different land‐use pressures. One key upland species that is potentially affected by livestock grazing, and is of considerable interest to both foresters and nature conservationists, is the field vole Microtus agrestis. Relaxation of livestock grazing can result in an increase in vole numbers. This in turn could have both positive and negative implications for biodiversity as (i) field voles are a major source of prey for other species and (ii) they are a cause of damage to newly planted trees and potentially damaging in areas of native woodland regeneration.
A replicated, randomized block experiment, consisting of six replicates of four livestock grazing treatments, was established in 2003 (with baseline data collected in 2002). This enabled us to examine the effects of livestock grazing on field vole abundance.
We have demonstrated experimentally for the first time that livestock grazing pressure affects the abundance of field voles (as measured by a vole sign index) in the uplands. In the first year of the experiment, immediate treatment effects were detectable, with a lower abundance of voles in the conventionally grazed treatment compared with those in the ungrazed treatment, and with intermediate vole abundances in the lightly grazed treatments. The significant treatment effects became more apparent in 2004, with a higher abundance of voles in the extensively grazed mixed treatment (i.e. sheep and cattle) than in the extensively grazed treatment that contained only sheep.
Synthesis and applications. In order to maximize biodiversity in the uplands, our results suggest that low intensity livestock grazing, used in a novel ways, could be a useful management tool to reduce vole abundance (and hence subsequent tree damage) compared with excluding livestock from young plantations completely. Furthermore, vole abundance would be higher at low grazing intensity compared with conventional stocking rates, thus still providing food for raptors and other vole‐eating vertebrates. Indeed, low‐intensity sheep and mixed livestock grazing might improve prey availability as a direct consequence of increased heterogeneity in vegetation structure. Our results suggest that it may be possible to maintain the open character of moorland habitats, and benefit key upland species generally, by reducing sheep grazing pressure and introducing low‐intensity mixed livestock grazing throughout the uplands.
Modes of imprinted gene action in learning disability
Authors: Isles A. R. , Humby T. 
Published: March 2006

AbstractBackground  It is now widely acknowledged that there may be a genetic contribution to learning disability and neuropsychiatric disorders, stemming from evidence provided by family, twin and adoption studies, and from explicit syndromic conditions. Recently it has been recognized that in some cases the presentation of genetic syndromes (or discrete aspects of disorders) is dependent on the sex of the transmitting parent. Such ‘parent‐of‐origin effects’ can be explained by a number of genetic mechanisms, a predominant one of which is genomic imprinting. Genomic imprinting refers to the parent of origin‐specific epigenetic marking of an allele of a gene, such that for some genes it is mainly the maternally inherited allele only that is expressed, whereas for others expression occurs mainly from the paternal copy.Methods  Here we discuss the contribution of imprinted genes to mental dysfunction and learning disability, using clinical examples of association studies and explicit imprinting disorders (with particular emphasis to Angelman and Prader–Willi syndromes), and evidence from animal work.Results  Clinical and animal studies strongly suggest that imprinted genes contribute to brain functioning, and when the genes or epigenetic processes are disrupted, this can give rise to neuropsychiatric problems. Another system to which imprinted genes provide a large contribute is the placenta and foetal development. Epidemiological studies suggest that this is also a key area in which dysregulation can give rise to learning difficulties.Conclusions  Disruption of imprinted genes, or the epigenetic processes controlling them, can contribute to learning disability. These effects can be divided into two types: direct effects, such as those seen in explicit imprinting disorders such as Angelman and Prader–Willi syndromes, and indirect effects as manifest via changes in foetal programming.
Clinical significance of hiatal hernia in the development of gastroesophageal reflux after distal gastrectomy for cancer of the stomach
Authors: Fujiwara Yoshinori , Nakao Koji , Inoue Takashi , Koishi Kenji , Nishio Yoshimasa , Yagyu Ryuichirou , Nakagawa Kazuhiko , Yamamura Takehira 
Published: March 2006

AbstractBackground and Aims:  The relationship between gastroesophageal reflux disease and sliding hernia is controversial, especially following distal partial gastrectomy in patients with gastric cancer. The aim of this study was to examine the relationship between gastroesophageal reflux disease and sliding hernia of the esophagus after distal gastrectomy using the gastroesophageal scintigraphy and endoscopy.Methods:  Forty‐five distal gastrectomy patients diagnosed with cancer of the stomach were studied. Twenty‐five patients presented with reflux symptoms, such as heartburn and/or regurgitation and 20 patients exhibited no reflux symptoms. All of the patients were examined by gastroesophageal scintigraphy and their reflux indices were determined. Thirty‐eight of the patients underwent upper endoscopy and both sliding hernias and reflux symptoms were classified as mild or severe.Results:  Sliding hernias were diagnosed in all of the subjects and 65.8% of the patients exhibited reflux symptoms. Evidence of endoscopic esophagitis was noted in only 39.5% of the patients. The reflux indices for the mild and severe hernia groups were 5.03 ± 2.2 and 10.3 ± 6.4, respectively (P < 0.05). More severely symptomatic esophagitis was prevalent in the severe hernia group in comparison to the mild group (P < 0.05).Conclusion:  The results suggest that the onset of gastroesophageal reflux after distal gastrectomy is induced by the surgical procedures and that hiatal hernia may be an important factor in the etiology of reflux esophagitis.
Ultrasonographic evaluation of gallbladder functions in patients with irritable bowel syndrome
Authors: Güçlü Mustafa , Pourbagher Ali , Serin Ender , Kul Kemal , Özer Birol , Cosar Arif , Içer M Okan , Gür Gürden , Boyacioglu Sedat 
Published: March 2006

AbstractBackground:  The aim of the present study was to evaluate gallbladder function in irritable bowel syndrome (IBS) patients.Methods:  The functions of gallbladder were investigated every 30 min for 4 h. In addition, ejection fraction of the gallbladder was calculated from the fasting and post‐prandial volumes.Results:  In IBS patients and healthy controls, fasting gallbladder volumes were 19.64 ± 3.09 mL and 20.04 ± 1.82 mL, and residual volumes after 3 h were 3.36 ± 6.82 mL and 9.74 ± 1.50 mL. Except for the residual volume after 3 h, all these results were not statistically significant. Residual volume after 3 h was statistically significantly lower in the IBS patients than in the controls (P < 0.001). Ejection fraction of the gallbladder was significantly higher in the IBS patients than in the controls (84% vs 55%, P < 0.001).Conclusions:  Gallbladder contraction in patients with IBS was not different from that of a control group at post‐prandial second hour but was signigicantly more pronounced at the end of 3 h when compared with controls. Ejection fraction of the gallbladder was higher in IBS patients when compared with controls.
Association between hepatitis A virus and Helicobacter pylori in a developing country: The saga continues
Authors: Bizri Abdul Rahman N , Nuwayhid Iman A , Hamadeh Ghassan N , Steitieh Souzan W , Choukair Ali M , Musharrafieh Umayya M 
Published: March 2006

AbstractBackground:   The epidemiologic association between Helicobacter pylori and hepatitis A virus (HAV) has been evaluated by various different groups with conflicting conclusions. The aim of the present study was to determine the prevalence of HAV and H. pylori infection among adolescents attending high schools in Lebanon, and to identify the sociodemographic factors associated with their prevalence, individually and concurrently.Methods:   Nine hundred and two school students 14–18 years of age were selected randomly from 30 schools scattered all over Lebanon and tested for IgG antibodies against hepatitis A and H. pylori. Each student received a copy of a self‐administered questionnaire to be completed by his/her parents inquiring about demographics, history of immunization, and prior viral hepatitis illness in the student. Bivariate analysis examined the association between different sociodemographic variables and prior HAV or H. pylori infection, and multivariate regression analysis was done to determine the factors independently associated with prior infection.Results:   Using ELISA the seroprevalence of antibodies against HAV was 71.3% as compared to 61.6% for anti‐H. pylori. A total of 9.1% of those tested were negative for both agents. A multinomial regression analysis revealed that place of residence in relation to district or urban versus rural areas, in addition to mothers’ education, were important determinants for the incidence of both agents.Conclusion:   The low number of subjects negative for both H. pylori and HAV antibodies in Lebanon is indicative of their high prevalence in the country. It is possible that this high prevalence reflects an age‐specific prevalence rather than a true association.
Expression of gamma‐aminobutyric acid and glutamic acid decarboxylases in rat descending colon and their relation to epithelial differentiation
Authors: WANG Fang Yu , ZHU Ren Min , MAEMURA Kentaro , HIRATA Ichiro , KATSU Ken‐ichi , WATANABE Masahito 
Published: March 2006

OBJECTIVE:  To detect the expression of gamma‐aminobutyric acid (GABA) and glutamic acid decarboxylases (GADs; including two isoforms GAD65 and GAD67) in the epithelial growth zones of the descending colon in rats, and to investigate their relation to epithelial differentiation and proliferation.METHODS:  The expression of GABA and GADs in rat descending colon was investigated by immunofluorescent staining and confocal laser scanning techniques, and goblet cells were further investigated by wheat‐germ agglutinin histochemistry. In addition, GAD65 and GAD67 mRNAs were also detected by reverse transcription‐polymerase chain reaction. Furthermore, evaluation of cell kinetics in colonic epithelia was conducted by ABC immunostaining using a monoclonal antibody against proliferating cell nuclear antigen (PCNA).RESULTS:  Immunoreactive GABA and GADs were distributed in the upper third of the crypts and at the luminal surface in the rat descending colon. Strong staining for GABA and GADs was localized mainly in the cytoplasm of epithelial cells near the neck of the crypts and along the luminal surface. In addition, GABA and GAD65 were also detected at the lamina propria in colonic mucosa. No staining for GABA or GADs was found in goblet cells. GAD65 and GAD67 mRNAs were identified in homogenates of rat descending colon. PCNA labeled nuclei were found in the lower two‐thirds of the crypts.CONCLUSIONS:  The expression of GABA and GADs in the maturation and function zones of rat descending colon suggests that GABA may be involved in the differentiation of colonic epithelial cells.
Effect of change in an inhibitory neurotransmitter of the myenteric plexus on the pathogenetic mechanism of irritable bowel syndrome subgroups in rat models
Authors: XU Jun Rong , LUO Jin Yan , SHANG Lei , KONG Wu Ming 
Published: March 2006

OBJECTIVE:  In order to investigate the effect of change in an inhibitory neurotransmitter of the myenteric plexus on irritable bowel syndrome (IBS) subgroups, the amounts of nitric oxide (NO) in constipation‐predominant (C‐IBS) and diarrhea‐predominant (D‐IBS) IBS models in rats were studied.METHODS:  The D‐IBS model was created in rats by intracolonic instillation of acetic acid and by restraint stress. The D‐IBS control group underwent intracolonic instillation with saline instead. The C‐IBS model was created in rats by gastric instillation of 0–4°C cool water daily for 14 days. The C‐IBS control group underwent gastric instillation with saline instead. A blank control group was also made. Viscerosomatic sensitivity was assessed with electromyographic (EMG). Abdominal contractions induced by distension of a colonically inserted balloon (0–1.6 mL) was recorded in rats by implanting electrodes in the abdominal external oblique muscle. An India ink gastric instillation experiment was used to detect the bowel movement and fecal pellets formation. Histological analysis of colonic tissue was performed. Nicotinamide dinucleotide phosphate (NADPH)‐diaphorase staining was used to detect positive NO neurons in the myenteric plexus.RESULTS:  When the balloon was distended by high volume, there were significantly more contractions of abdominal muscle in D‐IBS compared with C‐IBS and the control groups (P < 0.05). When the balloon was distended by low volume, there were significantly fewer contractions of abdominal muscle in C‐IBS compared with D‐IBS and the control groups (P < 0.05). The wet weight and water content of the feces expelled by the rats in the C‐IBS and the C‐IBS control groups were significantly lower than those in the blank control group (P < 0.05). The time before the first black stool in the C‐IBS group was significantly longer than that in the blank control group and C‐IBS control group (P < 0.05). Histological analysis of the colon showed no colonic inflammation in any group. The number of NO‐positive neurons in the C‐IBS group was significantly greater than in the D‐IBS and control groups (P < 0.01), although there was no significant difference in the number of neurons between the D‐IBS and the control groups (P > 0.05).CONCLUSIONS:  Enhanced inhibitory neurotransmitter NO in the myenteric plexus of the colon is related to IBS subgroups, visceral sensitivity and motility dysfunction. The results reveal that NO plays a role in the pathogenetic mechanism of IBS subgroups.
Evaluating the role of serum elastase 1 in the diagnosis of pancreatic cancer
Authors: WU Dong , QIAN Jia Ming , DENG Rui Xue , JIANG Wei Jun , CHEN Yuan Jia , LIU Xiao Hong , LU Xing Hua 
Published: March 2006

OBJECTIVE:  To determine the normal value of serum elastase 1 in Chinese adults and evaluate its diagnostic value for pancreatic cancer.METHODS:  Serum elastase 1 and CA19‐9 were measured in 132 samples, including 39 patients with pancreatic cancer, 48 with other gastrointestinal malignancy, 24 with gastrointestinal benign disease and 21 healthy adults as normal control. Multiple statistical methods including receiver operating characteristics curve and discriminant analysis were employed.RESULTS:  The established normal range of serum elastase 1 in Chinese adults was found to be under 4.36 mg/L. Serum elastase 1 increased markedly in patients with pancreatic carcinoma of smaller size and/or located in the pancreatic head. The sensitivity, specificity and overall accuracy of elastase 1 for diagnosis of pancreatic cancer were 61.5%, 75.3% and 71.2%, respectively, as compared with 71.8%, 73.1% and 72.7% for CA19‐9. Discriminant analysis can improve the sensitivity and overall accuracy of elastase 1 to 82.0% and 74.2%, respectively, with a slight decline in the specificity to 71.0%.CONCLUSIONS:  The cutoff value of serum elastase 1 in normal Chinese adults is 4.36 mg/L. Serum elastase 1 is effective in the diagnosis of pancreatic cancer, especially for those of smaller size or in the pancreatic head. Use of appropriate statistical methods can help to make the diagnosis more accurate.
Diet and gastric cancer: a case–control study in Shanghai urban districts
Authors: FEI Su Juan , XIAO Shu Dong 
Published: March 2006

OBJECTIVE:  The incidence rates of gastric cancer in Shanghai urban districts have been markedly declining over the past three decades. From 1972 to 2001 the age‐adjusted incidence rates of gastric cancer decreased from 62.0 to 32.5 per 100 000 in men and from 23.9 to 16.9 per 100 000 in women. This study aimed to investigate the relationship between environmental factors, in particular dietary factors, and the development of gastric cancer in those who lived in Shanghai urban districts for more than 15 years, and to explore the causes that led to the reduction of the incidence rates of gastric cancer in Shanghai.METHODS:  One hundred and eighty‐nine patients with gastric cancer and 567 age and sex‐matched controls were surveyed with a questionnaire. SPSS software package was used to perform the univariate and multivariate unconditional logistic regression analysis modeling.RESULTS:  Vitamin supplements, use of home refrigerators, high consumption of fresh fruits and vegetables, bean and dairy products, and good meal habits were protective factors against gastric cancer. However, family history of cancer, chronic gastric diseases, increased intake of salted, pickled, fried and smoked foods, poor meal habits, smoking and alcohol drinking were risk factors for gastric cancer.CONCLUSIONS:  The reduction of the incidence of gastric cancer in Shanghai urban district in the past three decades is closely related to environmental factors, in particular dietary factors and wide use of home refrigerators.
Analysis of gene expression profile in colon cancer using the Cancer Genome Anatomy Project and RNA interference
Authors: HUANG Zhi Gang , RAN Zhi Hua , LU Wei , XIAO Shu Dong 
Published: March 2006

OBJECTIVE:  To investigate the changes in the gene expression profile in colon cancer to further identify gene markers that may be useful in the management of this disease.METHODS:  Data from serial analysis of gene expression (SAGE) collected by the Cancer Genome Anatomy Project (CGAP) were used to detect the difference in gene expression between normal tissue and colon cancer, and were further confirmed in a sample of 20 patients using RT‐PCR. To identify the functions of differential genes in regulating the cell growth of colon cancer, RNA interference (RNAi) was used to block one of these genes in the colon cancer cell line HCT‐116.RESULTS:  Expression changes of greater than twofold in two SAGE libraries of colon cancer compared to two of normal tissue were observed for 216 tags of a total of 195 160 transcript tags (54 up‐regulated genes and 136 down‐regulated genes). Subsequent analysis of 17 genes by RT‐PCR confirmed the reliability of this analysis. RNAi‐mediated blockage of one of these genes, transforming growth factor (TGF)β1, significantly reduced the growth of a colon cancer cell line.CONCLUSIONS:  The combination of CGAP analysis and RNAi provides an excellent system to rapidly define the specific genes that are up‐regulated in cancer to impact the growth of cancer cells. Further study on these differential overexpressed genes may provide gene markers for the detection and treatment of colon cancer.
How prevalent are pH‐specialist diatoms? A reply to Telford et al. (2006)
Authors: Pither Jason , Aarssen Lonnie W. 
Published: March 2006

AbstractTelford, Vandvik and Birks (2006) (henceforth TVB) refute our conclusion (Pither & Aarssen 2005) that only a minority of fossil diatom taxa within a diverse regional assemblage are pH specialists. They argue that the null model we used exhibited high Type II error rates for both geographically rare taxa (i.e. few lakes occupied) and for acid‐optima taxa, and assert that many more taxa would have been designated specialist had we adequate statistical power, and had more acidic lakes been sampled. However, TVB base their conclusions upon the results of additional analyses, which assume a priori that all taxa are pH specialists. Experimental and observational evidence do not support this assumption. As such, we contend that TVBs criticisms are unjustified.