bluuebunny/crossref_metadata_2025 huggingface dataset:
Direct profiling and imaging of plant metabolites in intact tissues by using colloidal graphite‐assisted laser desorption ionization mass spectrometry
Authors: Cha Sangwon , Zhang Hui , Ilarslan Hilal I. , Wurtele Eve Syrkin , Brachova Libuse , Nikolau Basil J. , Yeung Edward S.
Published: April 2008

Laser desorption/ionization (LDI)‐based imaging mass spectrometry (MS) has been applied to several biological systems to obtain information about both the identities of the major chemical species and their localization. Colloidal graphite‐assisted LDI (GALDI) MS imaging was introduced for the imaging of small molecules such as phospholipids, cerebrosides, oligosaccharides, flavonoids, and other secondary metabolites with high spatial homogeneity due to finely dispersed particles. Mass profiles and images of Arabidopsis thaliana have been recorded directly from various plant surfaces and cross sections. The main targeted metabolites were flavonoids and cuticular waxes, both of which are important in many aspects of functional genomics, proteomics, and metabolomics. The mass spectral profiles revealed tissue‐specific accumulation of flavonoids in flowers and petals. In addition, many other location‐specific ions were observed. The location and the degree of light‐induced accumulation of flavonoids in stem sections were successfully probed by GALDI MS.
CRY1 inhibits COP1‐mediated degradation of BIT1, a MYB transcription factor, to activate blue light‐dependent gene expression in Arabidopsis
Authors: Hong Sung Hyun , Kim Hyo Jung , Ryu Jong Sang , Choi Hyunmo , Jeong Suyeong , Shin Jieun , Choi Giltsu , Nam Hong Gil
Published: April 2008

Cryptochromes (CRY) are one of the two major classes of photoreceptors that perceive light stimuli in the UV‐A to blue light region and they are involved in multiple aspects of plant growth and development. However, knowledge regarding their signaling transduction components and mechanisms remains limited. Here, we report that a MYB transcription factor Blue Insensitive Trait 1 (BIT1), plays an important role in controlling blue light responses. Hypocotyl growth responses indicate that BIT1 functions as a positive element in blue light signaling, since BIT1 antisense and knock‐out lines show a reduced light response in blue light. BIT1 controls blue light‐dependent expression of various genes such as PsbS, a member of the light‐harvesting complex gene family. A transactivation assay showed that BIT1 regulates promoter activity of PsbS in a blue light‐dependent manner and that it requires CRY1 for activation of the PsbS promoter. BIT1 undergoes degradation in darkness and CRY1 functions to stabilize BIT1 in a blue light‐dependent manner. In contrast, COP1 binds to BIT1 and mediates its degradation. We propose that the PsbS promoter is activated in blue light via the blue light‐dependent stabilization of BIT1 by CRY1, while in darkness BIT1 is degraded by COP1‐mediated proteolysis.
Cysteinyl‐leukotrienes in nasal lavage fluid in children with asthma
Authors: Singer Florian , Horak Friedrich , Friesenbichler Waltraud , Schneider Barbara , Szépfalusi Zsolt , Frischer Thomas
Published: April 2008

The aim of this study was to investigate repeatability of cysteinyl‐leukotrienes (cys‐LT) measurements in nasal lavage fluid (NLF) and to determine if cys‐LT levels in NLF are related to asthma severity in children. As a second outcome, we investigated if cys‐LT in NLF reflect lower airway inflammation as assessed by exhaled NO measurement. To assess the repeatability of cys‐LT measurements, two NLF samples were obtained from eight healthy controls 24 h apart. Sixty‐nine asthmatic children (mean age; range: 12.8; 7.3–17.7 yr), which were grouped according to asthma severity were studied cross‐sectionally on one occasion. Cys‐LT in NLF were analyzed using a specific enzyme immunoassay, exhaled NO, and pulmonary function parameters were measured. The coefficient of repeatability for the repeated cys‐LT measurements was 1.45 pg/ml. Cys‐LT levels in NLF differed significantly between asthma severity groups (p < 0.001): mild intermittent: [median (IQR)] 6.88 pg/ml (2.00–27.87); mild persistent: 21.09 pg/ml (4.50–84.67); and moderate persistent asthmatics: 36.41 pg/ml (11.03–118.40). Concentration of cys‐LT in NLF and exhaled NO was positively correlated (r = 0.85; p < 0.001). In conclusion, concentration of cys‐LT in NLF correlates with asthma severity in children and is related to lower airway inflammation.
Crops and genotypes differ in efficiency of potassium uptake and use
Authors: Rengel Zed , Damon Paul M.
Published: April 2008

Cultivars with increased efficiency of uptake and utilization of soil nutrients are likely to have positive environmental effects through reduced usage of chemicals in agriculture. This review assesses the available literature on differential uptake and utilization efficiency of K in farming systems. Large areas of agricultural land in the world are deficient in K (e.g. 3/4 of paddy soils in China, 2/3 of the wheatbelt in Southern Australia), with export in agricultural produce (especially hay) and leaching (especially in sandy soils) contributing to lowering of K content in the soil. The capacity of a genotype to grow and yield well in soils low in available K is K efficiency. Genotypic differences in efficiency of K uptake and utilization have been reported for all major economically important plants. The K‐efficient phenotype is a complex one comprising a mixture of uptake and utilization efficiency mechanisms. Differential exudation of organic compounds to facilitate release of non‐exchangeable K is one of the mechanisms of differential K uptake efficiency. Genotypes efficient in K uptake may have a larger surface area of contact between roots and soil and increased uptake at the root–soil interface to maintain a larger diffusive gradient towards roots. Better translocation of K into different organs, greater capacity to maintain cytosolic K+ concentration within optimal ranges and increased capacity to substitute Na+ for K+ are the main mechanisms underlying K utilization efficiency. Further breeding for increased K efficiency will be dependent on identification of suitable markers and compounding of efficiency mechanisms into locally adapted germplasm.
Antral mass due to cytomegalovirus infection requiring gastrectomy in a liver transplant recipient
Authors: Lladó L. , Castellote J. , Fabregat J. , Carratalà J. , Serrano T. , Ramos E. , Torras J. , Rafecas A.
Published: April 2008

Abstract: The incidence of cytomegalovirus (CMV) infection after liver transplantation (LT) has decreased in recent years. Advances in immunosuppression and CMV prophylaxis have improved the management of CMV disease. Organ involvement is infrequent and gastrointestinal CMV disease is quite rare. Few cases of an antral mass due to CMV infection have been described; those reported to date have mostly been in patients with acquired immunodeficiency syndrome. We describe a case of a CMV‐seronegative liver transplant patient who received a seropositive liver graft. Owing to gastrointestinal complaints, CMV prophylaxis was stopped one month after LT. The patient developed an antral mass due to CMV infection and an anastomotic biliary stricture. Antigenemia became negative with ganciclovir, but this treatment did not eliminate the mass. Ganciclovir resistance was ruled out as well as other causes of antral mass, especially malignancy. The patient finally required gastrectomy and hepaticojejunostomy. We conclude that CMV disease is less common today but should be included in the diagnosis of gastrointestinal mass after transplantation.
Gene expression of AGS cells stimulated with released proteins by Helicobacter pylori
Authors: Kim Nayoung , Park Woong‐Yang , Kim Jung Mogg , Park Ji Hyun , Kim Joo Sung , Jung Hyun Chae , Song In Sung
Published: April 2008

Background and Aim:  Interactions between released proteins by Helicobacter pylori (H. pylori) and the cells of gastric epithelium to which it adheres may contribute to gastric inflammation and epithelial damage. The present study was performed to evaluate the gene expression of AGS gastric cancer cells stimulated with released proteins by H. pylori.

Methods:  Gene expression of AGS cells to the stimulation by H. pylori‐released proteins (G27 strain) were monitored using oligonucleotide microarrays.

Results:  Eighty‐eight genes (0.88%) and eight genes (0.08%) were up‐ or downregulated, respectively, by treating AGS cells with H. pylori‐released proteins but not by H. pylori adhesion after 12 h of coculture. Out of the selected 40 up‐ and five downregulated genes, 29 upregulated genes classified as general RNA polymerase II transcription factor activity (GTF2B, PPARGC1A), SH3/SH2 adaptor activity (CRKL), transferase activity (ACLY, CRKL, PIGC, PLK4), and oxidoreductase activity (IDH1) were confirmed to be upregulated by released proteins and not by H. pylori adhesion by real‐time reverse transcription–polymerase chain reaction. When the concentrated H. pylori‐cultured supernatant prepared by our protocol was treated by boiling, the upregulations of 26 of these 29 genes (89.7%) except for CD160, ZNF268, and PSAT1 disappeared. This confirmed that most of these upregulations were caused by released proteins.

Conclusion:  Host genes involving transcription, signaling and stress are significantly modulated by the proteins released by H. pylori. This might strengthen the gastroduodenal pathogenesis induced by H. pylori.
Endoscopic mucosal resection: Not only therapeutic, but a diagnostic procedure for sessile gastric polyps
Authors: Szalóki Tibor , Tóth Veronika , Németh István , Tiszlavicz László , Lonovics János , Czakó László
Published: April 2008

Background and Aims:  Histological examination of specimens obtained by forceps biopsy sampling of gastric lesions is of limited accuracy, and their management on this basis is therefore controversial. Endoscopic mucosal resection (EMR) was initially developed in Japan for the resection of early gastric cancer (EGC). The potential use of EMR as a diagnostic tool has been suggested. The aims of the present study were to assess the value of forceps biopsy sampling in establishing the correct diagnosis revealed by EMR and to evaluate the efficacy of EMR.

Methods:  Fifty‐six subjects with sessile gastric polyps of epithelial origin, at least 0.5 cm in diameter, and not associated with polyposis syndromes, were included. Following forceps biopsy sampling, EMR was performed with an inject‐and‐cut technique or with cap‐fitted methods. The histological results on the forceps biopsy and the resected specimens were analyzed.

Results:  Histology on the resected specimens revealed neoplastic lesions in 34 cases, including seven EGC, and there were hyperplastic‐inflammatory lesions in 21 cases. Complete agreement between the previous histological results of the forceps biopsy samples and the resected specimens was seen in only 76.7% of the lesions. Altogether, the sensitivity and specificity of the forceps biopsy procedure for diagnosing neoplastic lesions were 87.5% (95% confidence interval [CI] = 76.0–98.9%) and 65.2% (95% CI = 45.7–84.7), respectively. A clinically relevant discrimination between neoplastic and non‐neoplastic lesions was not achieved in seven cases. No complications, such as perforation or massive bleeding necessitating surgical treatment, were encountered. EMR was considered complete in five patients. None of the EGC recurred during the mean 38‐month (6–72) follow up.

Conclusions:  Forceps biopsy is not fully representative of the entire lesion, and a simple biopsy may therefore lead to a faulty differentiation between neoplastic and non‐neoplastic lesions. EMR proposes diagnostic and staging advantage in assessing patients with EGC as compared to forceps biopsy, because it provides more intact mucosa and submucosa for histological analysis. Sessile gastric polyps should be fully resected by EMR for a final diagnosis and (depending on the lesion size and type) possibly definitive treatment.
Risk factors of lymph node metastasis in T1 esophageal squamous cell carcinoma
Authors: Kim Dong Uk , Lee Jun Haeng , Min Byung‐Hoon , Shim Sang Goon , Chang Dong Kyung , Kim Young‐Ho , Rhee Poong‐Lyul , Kim Jae J , Rhee Jong Chul , Kim Kyoung‐Mee , Shim Young Mog
Published: April 2008

Background and Aim:  To perform endoscopic mucosal resection (EMR) for T1 esophageal cancer, it is essential to estimate the lymph node status exactly. In order to evaluate the feasibility of EMR for esophageal cancers, we evaluated the clinicopathological features of T1 esophageal squamous carcinomas with an emphasis on the risk factors and distribution patterns of lymph node metastasis.

Methods:  From 1994 to 2006, a total of 200 patients with T1 esophageal carcinoma were treated surgically in our institution. Among them, clinicopathological features were evaluated for 197 consecutive patients with T1 squamous cell carcinoma.

Results:  The frequency of lymph node involvement was 6.25% (4/64) in mucosal cancers and 29.3% (39/133) in submucosal cancers (P < 0.001). In patients with M1 (n = 32) and M2 (n = 14) cancers, no lymph node metastasis was found. In multivariate analysis, size larger than 20 mm, endoscopically non‐flat type, and endo‐lymphatic invasion were significant independent risk factors for lymph node metastasis. The differentiation of tumor cell was not a risk factor for lymph node metastasis.

Conclusions:  We suggest that EMR may be attempted for flat superficial squamous esophageal cancers smaller than 20 mm. After EMR, careful histological examination is mandatory.
Disturbed gastrointestinal motility and decreased interstitial cells of Cajal in diabetic db/db mice
Authors: Yamamoto Takahiro , Watabe Kenji , Nakahara Masanori , Ogiyama Hideharu , Kiyohara Tatsuya , Tsutsui Shusaku , Tamura Shinji , Shinomura Yasuhisa , Hayashi Norio
Published: April 2008

Background and Aim:  Diabetes mellitus (DM) often causes gastrointestinal dysmotility. Interstitial cells of Cajal (ICC), which express c‐kit receptor tyrosine kinase (KIT), are considered the pacemaker cells for gastrointestinal movement. The present study was designed to determine the role of ICC in the pathogenesis of gastroenteropathy in type 2 DM.

Methods:  We examined C57BL/KsJ‐db/db mice as a model for type 2 DM. Gastrointestinal motility was evaluated by measuring gastric emptying, whole gut transit time, and isometric tension of the isolated small intestine. The area of KIT‐positive cells in the gastrointestinal tract was examined by image analysis of fluorescent immunohistochemistry. The mRNA expression of KIT ligand, stem cell factor (SCF), in the gastrointestinal tract was quantified by real‐time reverse transcription–polymerase chain reaction (RT‐PCR).

Results:  Compared with 12‐week‐old db/+m control mice, diabetic db/db mice of the same age exhibited delayed gastric emptying, prolonged whole gut transit time, irregular frequency of isometric tension in the small intestine, smaller areas of KIT‐positive cells in the antrum, small intestine, and colon, and lower mRNA expression levels of SCF in the small intestine and colon.

Conclusions:  We demonstrated disturbed gastrointestinal motility in db/db mice with reduced areas of ICC and expression of SCF. Our results suggest the involvement of ICC in the gastroenteropathy of type 2 DM.
Clinicopathological features of gastric cancer detected by endoscopy as part of annual health checkup
Authors: Aida Kayo , Yoshikawa Hiroyuki , Mochizuki Chihiro , Mori Atsuyoshi , Muto Shigeki , Fukuda Takanori , Otsuki Makoto
Published: April 2008

Background and Aim:  Upper gastrointestinal endoscopy is generally accepted as the gold standard for the clinical evaluation of gastric cancer (GC). However, the efficacy of endoscopic screening for asymptomatic GC remains controversial. The present study is designed to clarify the efficacy of endoscopic screening for the detection of early GC by investigating the clinicopathological features.

Methods:  A total of 17 522 patients who had underwent endoscopic screening as a part of their annual health checkup at the Seirei Center for Health Promotion and Preventive Medicine between April 2002 and March 2006 were enrolled in this study. We investigated the clinicopathological findings of GC detected by endoscopy. Furthermore, in accordance with the screening interval at our center, patients with GC were categorized into two groups: group A, patients with repeated endoscopic screening within the last 2 years, and group B, patients without endoscopic screening within the last 2 years.

Results:  Thirty‐nine GC (mean age of patients: 62.2 ± 8.0 years, 36 males and three females) were detected in total (0.22%). The proportion of early GC was 87.2%. Notable differences between groups A and B were not found in the rate of early GC (P = 0.6342). However, eight of 27 cases (29.6%) in group A were treated by endoscopic resection, but none in group B (P = 0.0344). In six of 26 cases (23.1%) in group A, the recorded images from the previous endoscopic examination indicated some macroscopic abnormalities at the same location, suggesting GC or premalignant lesions.

Conclusion:  Endoscopic screening is useful for detecting GC at the early stages, and repeated examinations at short‐time intervals contribute to the detection of resectable lesions by endoscopy. Further studies are needed to decrease the false negative rate of endoscopic screening.
Malnutrition in end stage liver disease: Recommendations and nutritional support
Authors: Tsiaousi Eleni T , Hatzitolios Apostolos I , Trygonis Sotirios K , Savopoulos Christos G
Published: April 2008

Malnutrition has increasingly been acknowledged as an important prognostic factor which can influence the clinical outcome of patients suffering from end‐stage liver disease (ESLD). Despite the fact that malnutrition is not included in the Child–Pugh classification, its presence should alert clinicians to the same extent as do other complications, such as ascites and hepatic encephalopathy. The pathophysiological mechanisms and the clinical conditions that drive cirrhotic patients to an ill‐balanced metabolic state are multiple and they intertwine. Inadequate offer of nutrients, the hypermetabolic state in cirrhosis, the diminished synthetic capacity of the liver and the impaired absorption of nutrients are the main reasons that disrupt the metabolic balance in ESLD. Identifying patients that are approaching the state of malnutrition by simple and easily applied methods is necessary in order to provide nutritional support to those that need it most. According to the European Society for Clinical Nutrition and Metabolism, simple bedside methods such as Subjective Global Assessment and anthropometric parameters are reliable in assessing the nutritional state of cirrhotic patients. Correcting the nutrient deficit of the affected patients is mandatory. Avoidance of alcohol and excess fat and ingestion of 4–6 meals/day containing carbohydrates and protein are the most common recommendations. In severe malnutrition, initiation of enteral feeding and/or use of special formulae such as branched‐chain amino acid‐enriched nutrient mixtures are often recommended. Enteral nutrition improves nutritional status and liver function, reduces complications, prolongs survival and is therefore indicated.
On the relationship between methane production and oxidation by anaerobic methanotrophic communities from cold seeps of the Gulf of Mexico
Authors: Orcutt Beth! , Samarkin Vladimir , Boetius Antje , Joye Samantha
Published: April 2008

The anaerobic oxidation of methane (AOM) in the marine subsurface is a significant sink for methane in the environment, yet our understanding of its regulation and dynamics is still incomplete. Relatively few groups of microorganisms consume methane in subsurface environments – namely the anaerobic methanotrophic archaea (ANME clades 1, 2 and 3), which are phylogenetically related to methanogenic archaea. Anaerobic oxidation of methane presumably proceeds via a ‘reversed’ methanogenic pathway. The ANME are generally associated with sulfate‐reducing bacteria (SRB) and sulfate is the only documented final electron acceptor for AOM in marine sediments. Our comparative study explored the coupling of AOM with sulfate reduction (SR) and methane generation (MOG) in microbial communities from Gulf of Mexico cold seep sediments that were naturally enriched with methane and other hydrocarbons. These sediments harbour a variety of ANME clades and SRB. Following enrichment under an atmosphere of methane, AOM fuelled 50–100% of SR, even in sediment slurries containing petroleum‐associated hydrocarbons and organic matter. In the presence of methane and sulfate, the investigated microbial communities produce methane at a small fraction (∼10%) of the AOM rate. Anaerobic oxidation of methane, MOG and SR rates decreased significantly with decreasing concentration of methane, and in the presence of the SR inhibitor molybdate, but reacted differently to the MOG inhibitor 2‐bromoethanesulfonate (BES). The addition of acetate, a possible breakdown product of petroleum in situ and a potential intermediate in AOM/SR syntrophy, did not suppress AOM activity; rather acetate stimulated microbial activity in oily sediment slurries.
Bacterial ectosymbionts and virulence silencing in a Fusarium oxysporum strain
Authors: Minerdi Daniela , Moretti Marino , Gilardi Giovanna , Barberio Claudia , Gullino Maria Lodovica , Garibaldi Angelo
Published: April 2008

In the present article we have ascertained the presence of a consortium of ectosymbiotic bacteria belonging to Serratia, Achromobacter, Bacillus and Stenotrophomonas genera associated to the mycelium of the antagonistic Fusarium oxysporum MSA 35 [wild‐type (WT) strain]. Morphological characterization carried out on the WT strain, on the F. oxysporum MSA 35 without ectosymbionts [cured (CU) strain] and on the pathogenic F. oxysporum f.sp. lactucae (Fuslat 10) showed that the ectosymbionts, present only in the WT strain, caused a depleted production of micro conidia and aerial hyphae, and a change in shape and dimension of the latter. Virulence tests showed that the cured Fusarium was a pathogenic strain and, as shown by polymerase chain reaction and microscope analysis, pathogenicity was correlated with the capability of the cured hyphae of penetrating lettuce roots. Accordingly, the hyphae of the WT strain were impaired in entering the plant roots. Typing experiments provided evidence that both CU and WT strains belong to F. oxysporum f.sp. lactucae. This implies that the antagonistic effect of WT Fusarium is not a fungal trait, but it is due to the interaction with the ectosymbiotic bacteria. Expression analysis showed that fmk1, chsV and pl1 genes involved in F. oxysporum pathogenicity are not expressed in the WT strain whereas they are expressed in the cured fungus. These results, together with the hyphal characteristics, suggest that the inability of WT strain to penetrate the plant roots could be due to alterations in the expression profile of cell wall‐degrading enzymes. In conclusion, we demonstrated a modulation of F. oxysporum gene expression in response to the interaction with the ectosymbiotic bacteria. Preliminary researches indicated that the presence of bacteria attached to the hyphae of antagonistic F. oxysporum is not an isolated phenomenon. Further investigations are necessary to better understand the rule and the diffusion of ectosymbiotic bacteria among antagonistic Fusarium.
Is there an alternative to pad tests? Correlation of subjective variables of severity of urinary loss to the 1‐h pad test in women with stress urinary incontinence
Authors: Franco Anna Virginia M. , Lee Frank , Fynes Michelle M.
Published: April 2008

OBJECTIVE

To compare the 1‐h pad test in women who have urodynamically confirmed stress incontinence (USI) with a patient‐based 3‐point symptom severity scale and validated quality of life (QoL) questionnaires.

PATIENTS AND METHODS

In all, 98 women with USI were prospectively recruited; all had a 1‐h pad test and completed the validated disease‐specific QoL questionnaires, including short forms of the International Consultation on Incontinence Questionnaire (ICIQ‐SF), Urogenital Distress Inventory (UDI‐6), and Incontinence Impact Questionnaire (IIQ‐7). In addition, the severity of incontinence was determined using the Stamey grading scale, a visual analogue scale (VAS) score, and a patient‐based 3‐point symptom severity scale.

RESULTS

The VAS, symptom severity scale, Stamey grade, UDI‐6, and IIQ‐7 failed to correlate significantly with the 1‐h pad test. Only the ICIQ‐SF correlated significantly with this test.

CONCLUSION

The ICIQ‐SF is easy to administer and, in this study, correlated best with the 1‐h pad test in women with pure primary or secondary USI. It incorporates both symptom severity and QoL variables. We recommend its routine use in clinical practice.
Accuracy of life tables in predicting overall survival in patients after radical prostatectomy
Authors: Walz Jochen , Suardi Nazareno , Shariat Shahrokh F. , Jeldres Claudio , Perrotte Paul , Graefen Markus , Widmer Hughes , Arjane Philippe , Valiquette Luc , Hutterer Georg , Saad Fred , Karakiewicz Pierre I.
Published: April 2008

OBJECTIVE

To test the accuracy of life tables (LT), the standard tool for predicting life‐expectancy (LE), but the accuracy of which is unknown in patients with prostate cancer, where the 10‐year LE is a widely accepted threshold for the delivery of definitive therapy.

PATIENTS AND METHODS

We tested the accuracy of predictions of LE from LT in 9678 men treated with radical prostatectomy (RP) for prostate cancer. The predictions of LE from LT at 10 years after RP were compared to Kaplan Meier‐derived 10‐year survival values. Moreover, the accuracy of LT predictions was quantified in a Cox‐regression using Harrell’s concordance index. To control for the effect of prostate cancer mortality, analyses were repeated in a subset of 5955 patients with no evidence of disease recurrence. Additional stratification schemes were applied to control for age and comorbidity.

RESULTS

At RP, the median age was 64 years, the median Charlson Comorbidity Index (CCI) was 1 and the median LT‐derived LE was 16 years. The median actuarial survival was not reached (mean 12.4 years). In the whole group the LT‐predicted 10‐year survival was 96.8%, vs an observed of 75.3%. In men with no disease recurrence the LT‐predicted survival was 97.3%, vs 81.1% observed. After age and CCI stratification, LT overestimated the 10‐year survival the most in those aged 65–69 years and in patients with CCI scores of >2.

CONCLUSION

The overestimation of LE can lead to overtreatment of prostate cancer, especially in those men who die early from other causes.
Imperfect Competition and Growth with Entrepreneurial Risk
Authors: Clemens Christiane
Published: April 2008

This paper analyzes an overlapping generations endogenous growth model of occupational choice under risk in a two-sector economy with intermediate and final goods. Agents choose between business ownership in the monopolistically competitive intermediate goods industry or employment as a worker in this sector. Firm-specific profits are stochastic. Occupational choice under risk endogenizes the number of firms and products in the intermediate goods industry. The analysis shows that economic performance and growth both depend on the entrepreneurship rate and are inefficiently low compared with an economy with perfect markets for pooling risks. Monopolistic competition partly offsets the negative income effects from a too low level of entrepreneurial risk-taking.
Active ageing policies in the Czech Republic and Poland
Authors: Perek‐Białas Jolanta , Ruzik Anna , Vidovićová Lucie
Published: April 2008

This article deals with active ageing as a policy concept and its meanings in different cultures. We describe the Czech Republic and Poland, formerly communist states that experienced economic and political transitions in the 1990s and joined the European Union in 2004. Both countries are demographically similar, with ageing populations, but their understanding of active ageing as a policy issue are quite different. The methodology used was a meta‐analysis of expert interviews and consultations. The results show that there is no comprehensive policy towards active ageing in Poland and the Czech Republic does not have an overall systemic vision based on the principles of active ageing. The debate on activity in old age focuses on labour market employment activity, neglecting most of the issues of social services, care‐giving or just plain leisure. The lack of institutional mechanisms, fiscal limitations, discriminatory socio‐cultural perceptions and an unfavourable economic climate have all constituted barriers to implementing active ageing strategies in the period analysed. However, it seems that the problem has been noticed and that demographic changes and the attitudes of the elderly in the future could bring forth a more wide‐ranging discussion on active ageing.
Autonomy as a balance of freedom and equality
Authors: Premat Christophe
Published: April 2008

Social inequalities are not due to the process of socialisation itself, but to the amplification of inequalities existing in a pre‐human state where there were no shared values and meanings. This state is fictitious in so far as human beings owe their humanity and their survival to a process of imposed social norms. As social subjects, they are incapable of surviving outside a social relationship. Using this anthropological basis two types of societies can be distinguished: heteronomous societies that justify inequality by a set of beliefs in the superiority of some beings over others, and autonomous societies that have formulated the abstract idea of equality of rights and conditions. Autonomy is the recognition that equality of conditions must be developed as part of a social compact that needs to be reinvented in every period in order to correct inequalities that persist in the welfare state. From this standpoint, inequalities drive social creativity, because individuals constantly need to create new institutions that are able to reduce the weight and injustice of such inequalities. This view avoids a utopian vision of equality that would negate a basic characteristic of human beings, namely, their power of creativity.
Rural market imperfections and the role of institutions in collective action to improve markets for the poor
Authors: Shiferaw Bekele , Obare Gideon , Muricho Geoffrey
Published: April 2008

Many countries in sub‐Saharan Africa have liberalized markets to improve efficiency and enhance market linkages for smallholder farmers. The expected positive response by the private sector in areas with limited market infrastructure has however been very limited. The functioning of markets is constrained by high transaction costs and coordination problems along the production‐to‐consumption value chain. New kinds of institutional arrangements are needed to reduce these costs and fill the vacuum left when governments withdrew from markets in the era of structural adjustments. One of these institutional innovations has been the strengthening of producer organizations and formation of collective marketing groups as instruments to remedy pervasive market failures in rural economies. The analysis presented here with a case study from eastern Kenya has shown that marketing groups pay 20–25% higher prices than other buyers to farmers while participation was also positively correlated with adoption of improved dryland legume varieties, crops not targeted by the formal extension system. However the effectiveness of marketing groups is undermined by external shocks and structural constraints that limit the volume of trade and access to capital and information, and require investments in complementary institutions and coordination mechanisms to exploit scale economies. Successful groups have shown high levels of collective action in the form of increased participatory decision making, member contributions and initial start‐up capital. Failure to pay on delivery, resulting from lack of capital credit, is a major constraint that stifles competitiveness of marketing groups relative to other buyers. These findings call for interventions that improve governance and participation; mechanisms for improving access to operating capital; and effective strategies for risk management and enhancing the business skills of farmer marketing groups.
Dissemination of food crops with nutritional benefits: Adoption and disadoption of soybeans in Togo and Benin
Authors: Wendland Kelly J. , Sills Erin O.
Published: April 2008

To combat high rates of malnutrition in sub‐Saharan Africa, the UN Millennium Project has called for increased emphasis on technologies that explicitly link agricultural and nutritional components. While there is a large literature on the factors that influence household decisions to adopt new agricultural technologies with economic or environmental benefits, less is known about the factors that determine the uptake and continued use of agricultural technologies promoted exclusively for their health benefits. Using data from a 2004 survey in the Tamberma region of Togo and Benin, we identify factors that influence the adoption and disadoption of soybeans — a crop being promoted throughout West Africa for its high protein content. Similar to the literature on adoption of other sustainable agriculture technologies, we find that household preferences, resource endowments, and risk and uncertainty affect household decisions about soybeans. However, by analyzing decisions about initial uptake and continued cultivation separately, we uncover the importance of intrahousehold dynamics and experience with the soybean crop. To successfully address malnutrition through new agricultural technologies, researchers and rural extension agents should take a disaggregated view of technology adoption, seeking to identify and tailor their outreach to the different factors important at different stages of the dissemination process.
Effects of high‐frequency stimulation on epileptiform activity in vitro: ON/OFF control paradigm
Authors: Su Yuzhuo , Radman Thomas , Vaynshteyn Jake , Parra Lucas C. , Bikson Marom
Published: April 2008

Summary

Purpose: To determine the effects of high‐frequency electrical stimulation on electrographic seizure activity during and after stimulation (ON‐effect and OFF‐effect).

Methods: The modulation and suppression of epileptiform activity during (ON‐effect) and after (OFF‐effect) high‐frequency electrical stimulation was investigated using the high‐K+ and picrotoxin hippocampal slice epilepsy models. Uniform sinusoidal fields (50 Hz) were applied with various intensity levels for 1 min across brain slices. Extracellular and intracellular activity were monitored during and after stimulation.

Results: The ON‐effects of high‐frequency stimulation were highly variable across individual slices and models; ON‐effects included modulation of activity, pacing, partial suppression, or activity resembling spreading‐depression. On average, epileptic activity, measured as power in the extracellular fields, increased significantly during stimulation. Following the termination of electrical stimulation, a robust poststimulation suppression period was observed. This OFF suppression was observed even at relatively moderate stimulation intensities. The duration of OFF suppression increased with stimulation intensity, independent of ON‐effects. Antagonism of GABA
A
function did not directly effect OFF suppression duration.

Conclusions: The present results suggest that “rational” seizure control protocols using intermittent high‐frequency electrical stimulation should control for both ON and OFF effects.
Granule cell dispersion develops without neurogenesis and does not fully depend on astroglial cell generation in a mouse model of temporal lobe epilepsy
Authors: Nitta Naoki , Heinrich Christophe , Hirai Hisao , Suzuki Fumio
Published: April 2008

Purpose:  Granule cell dispersion (GCD) appears as a characteristic morphological feature of the mesial temporal lobe epilepsy (MTLE). It has been suggested that this phenomenon could be due to an increased neurogenesis in the dentate gyrus. However, this hypothesis is still debated and recent clinical and experimental studies have shown that neurogenesis is rather decreased in MTLE. To further determine the role of neural and astroglial cell generation in GCD we examined the consequences of aging and irradiation, which are known to reduce progenitor cells, in a mouse model of MTLE induced by intrahippocampal kainate (KA) injection.

Methods:  We injected KA in hippocampus of three different types of mice; (1) young adult, (2) aged, and (3) irradiated mice. Newly generated cells were labeled by Bromodeoxyuridine (BrdU) and were characterized by immunohistochemistry. The extent of GCD was compared among the three animal groups.

Results:  In young adult mice, BrdU‐labeled neurons as well as doublecortin‐ and NeuroD‐positive cells decreased progressively after KA injection whereas BrdU‐labeled astrocytes and microglias increased. In aged and irradiated mice, where basal neurogenesis was already strongly reduced, GCD developed after KA injection to the same extent as in young adult mice. However, augmentation of the BrdU‐labeled astrocytes after KA was less than 40% in irradiated mice in comparison to young and aged mice.

Conclusions:  Our data show that GCD occurs without neurogenesis. Furthermore GCD developed regardless of the degree of astroglial cell proliferation, suggesting that neural stem cell generation is not crucial for GCD.
The Informational Role of International Institutions and Domestic Politics
Authors: Fang Songying
Published: April 2008

Why did President Bush attempt to acquire a UN Security Council resolution authorizing the use of force before the war with Iraq, even though there was a substantial risk that his request would be rejected? This article presents a game‐theoretic model to investigate how international institutions can shape the behavior of democratic leaders by influencing domestic politics. While it seems unsurprising that unbiased leaders who are truly concerned about foreign policy outcomes would consult international institutions, the results show that biased leaders with private agendas can also be forced to behave like the unbiased type because of their electoral concerns. The equilibrium results are illustrated with the cases of U.S. use of force in international crises.
Enlightened Nation Building: The “Science of the Legislator” in Adam Smith and Rousseau
Authors: Hanley Ryan Patrick
Published: April 2008

Rousseau is famous as an advocate of the politics of “denaturing.” But attention to his conception of the “science of the legislator,” as developed in the Geneva Manuscript and his writings on Poland and Corsica, reveals a more moderate approach to statecraft. Here Rousseau claims that legislative science requires tempering commitment to principles of political right with sensitivity to actual political conditions—a claim that importantly and unexpectedly parallels the better known account of the science of the legislator developed by Adam Smith. In comparing these conceptions, this article draws three conclusions: first, Smith's and Rousseau's shared moderation reveals their common commitment to accommodating the passions and prejudices of modernity; second, their fundamental difference concerns not practical legislative methods but rather differing conceptions of natural justice and political right; and finally, their prudential approach to legislation helps clarify the specific types of “moderation” and “intelligence” required of contemporary nation builders.
Change, Continuity, and the Evolution of the Law
Authors: Maltzman Forrest , Shipan Charles R.
Published: April 2008

Congress regularly passes significant laws. Some of these laws continue in their initial form, with the original bargain struck by the enacting coalition untouched by any future laws; others are changed—strengthened or weakened—soon after passage. What accounts for this variation in the stability of laws, in the longevity of the original legislative agreement? We contend that political conditions at the time of enactment—in particular, the existence of divided government and the level of ideological disagreement between the House and Senate—influence the likelihood that a law will be amended. We demonstrate that laws originally crafted by diverse political coalitions are less durable than those crafted by strong, unified coalitions, which are in a position to entrench their preferred policies and protect them from future change. Furthermore, we show that the probability of a law being amended is affected by future political conditions, the actions of the judiciary, and factors specific to the law.
Proffering Pork: How Party Leaders Build Party Reputations in Brazil
Authors: Lyne Mona M.
Published: April 2008

Despite its highly candidate‐centered electoral law, recent studies have shown that Brazilian party leaders are more powerful, and Brazilian parties are more unified, than alleged by long‐dominant scholarship. Examining post‐War and contemporary democracy in Brazil, governed by the same federal legislative electoral law, this article provides a controlled test of the role of leadership and electoral law in driving party unity. The combination of leadership intervention to enforce unity, increased unity, and partisan tides in contemporary Brazil, in contrast to an absence of leadership intervention, lower unity, and no partisan tides in the post‐War, provides strong support for the role of the leadership in generating unity, as emphasized in the collective action theory of party organization. The findings also suggest that a general theory of variation in party unity requires examining factors that lead to variation in party leaders' incentives to enforce unity, in addition to the current emphasis on backbenchers' incentives to defy the leadership.
Do Authoritarian Institutions Constrain? How Legislatures Affect Economic Growth and Investment
Authors: Wright Joseph
Published: April 2008

This article explores why authoritarian regimes create legislatures and then assesses their effect on economic growth and investment. In authoritarian regimes more dependent on domestic investment than natural resource revenue, the dictator creates a binding legislature as a credible constraint on the regime's confiscatory behavior. In regimes dependent on natural resource revenue, the nonbinding legislature serves as a mechanism for the dictator to bribe and split the opposition when he faces credible challenges to the regime. Using data from 121 authoritarian regimes from 1950 to 2002, the results indicate that binding legislatures have a positive impact on economic growth and domestic investment, while nonbinding legislatures have a negative impact on economic growth.
State Public Opinion, the Death Penalty, and the Practice of Electing Judges
Authors: Brace Paul , Boyea Brent D.
Published: April 2008

Do state supreme courts act impartially or are they swayed by public opinion? Do judicial elections influence judge behavior? To date these questions have received little direct attention due to the absence of comparable public opinion data in states and obstacles to collecting data necessary for comprehensive analysis of state supreme court outcomes. Advances in measurement, data archiving, and methodology now allow for consideration of the link between public opinion and judicial outcomes in the American states. The analysis presented considers public opinion's influence on the composition of courts (indirect effects) and its influence on judge votes in capital punishment cases (direct effects). In elective state supreme courts, public support for capital punishment influences the ideological composition of those courts and judge willingness to uphold death sentences. Notably, public support for capital punishment has no measurable effect on nonelective state supreme courts. On the highly salient issue of the death penalty, mass opinion and the institution of electing judges systematically influence court composition and judge behavior.
Race and the Recall: Racial and Ethnic Polarization in the California Recall Election
Authors: Segura Gary M. , Fraga Luis R.
Published: April 2008

In the 2003 recall election in California, Lt. Gov. Cruz Bustamante received more than 1.25 million fewer votes in the replacement election than votes cast against the recall of Gray Davis. A much smaller group voted “yes” on the recall but voted for Bustamante. The principal underlying explanation is racial and ethnic polarization. Using L.A. Times exit poll data, we compare the characteristics of voters who displayed the two unusual behavioral patterns with those who voted in more conventional ways. We find that Latinos and African Americans are far less likely than non‐Hispanic whites and Asian Americans to have defected from Bustamante given a “no” vote on the recall, and far more likely to have voted for Bustamante given a potentially strategic “yes” vote on the recall. The patterns of defection are consistent with racial polarization on Proposition 54, lending further credence to our claim that race and ethnicity persists as an important factor in vote choice, even in environments with a history of minority electoral success.
Who Fights? The Determinants of Participation in Civil War
Authors: Humphreys Macartan , Weinstein Jeremy M.
Published: April 2008

A range of seemingly rival theories attempt to explain why some individuals take extraordinary risks by choosing to participate in armed conflict. To date, however, competing accounts have typically not been grounded in systematic, empirical studies of the determinants of participation. In this article, we begin to fill this gap through an examination of the determinants of participation in insurgent and counterinsurgent factions in Sierra Leone's civil war. We find some support for all of the competing theories, suggesting that the rivalry between them is artificial and that theoretical work has insufficiently explored the interaction of various recruitment strategies. At the same time, the empirical results challenge standard interpretations of grievance‐based accounts of participation, as poverty, a lack of access to education, and political alienation predict participation in both rebellion and counterrebellion. Factors that are traditionally seen as indicators of grievance or frustration may instead proxy a for more general susceptibility to engage in violent action or a greater vulnerability to political manipulation by elites.
Multiple Imputation Methods for Treatment Noncompliance and Nonresponse in Randomized Clinical Trials
Authors: Taylor L. , Zhou X. H.
Published: April 2008

Summary Randomized clinical trials are a powerful tool for investigating causal treatment effects, but in human trials there are oftentimes problems of noncompliance which standard analyses, such as the intention‐to‐treat or as‐treated analysis, either ignore or incorporate in such a way that the resulting estimand is no longer a causal effect. One alternative to these analyses is the complier average causal effect (CACE) which estimates the average causal treatment effect among a subpopulation that would comply under any treatment assigned. We focus on the setting of a randomized clinical trial with crossover treatment noncompliance (e.g., control subjects could receive the intervention and intervention subjects could receive the control) and outcome nonresponse. In this article, we develop estimators for the CACE using multiple imputation methods, which have been successfully applied to a wide variety of missing data problems, but have not yet been applied to the potential outcomes setting of causal inference. Using simulated data we investigate the finite sample properties of these estimators as well as of competing procedures in a simple setting. Finally we illustrate our methods using a real randomized encouragement design study on the effectiveness of the influenza vaccine.