bluuebunny/crossref_metadata_2025 huggingface dataset:
The plasmids of Chlamydia trachomatis and Chlamydophila pneumoniae (N16): accurate determination of copy number and the paradoxical effect of plasmid-curing agents
Authors: Pickett Mark A. , Everson J. Sylvia , Pead Patrick J. , Clarke Ian N.
Published: March 2005

A 7·5 kbp cryptic plasmid is found in almost all isolates ofChlamydia trachomatis. Real-time PCR assays, using TaqMan chemistry, were set up to quantify accurately both the chlamydial plasmid and the single copy, chromosomalomcBgene in the infectious, elementary bodies (EBs) ofC. trachomatisL1 440. Plasmid copy number was also determined in the EBs of six other lymphogranuloma venereum (LGV) isolates (serovars L1–L3), ten trachoma isolates (serovars A–C) and nine urogenital isolates (serovars D–J). The results indicated an average plasmid copy number of 4·0±0·8 (mean±95 % confidence interval) plasmids per chromosome. During the chlamydial developmental cycle, up to 7·6 plasmids per chromosome were detected, indicating an increased plasmid copy number in the actively replicating reticulate bodies. Attempts to eliminate the plasmid from strain L1 440 using the plasmid-curing agents ethidium bromide, acridine orange or imipramine/novobiocin led to a paradoxical increase in plasmid copy number. It is speculated that the stress induced by chemical curing agents may stimulate the activity of plasmid-encoded replication (Rep) proteins. In contrast toC. trachomatis, only a single isolate ofChlamydophila pneumoniaebears a plasmid.C. pneumoniaestrain N16 supports a 7·4 kbp plasmid in which ORF1, encoding one of the putative Rep proteins, is disrupted by a deletion and split into two smaller ORFs. Similar assay techniques revealed 1·3±0·2 plasmids per chromosome (mean±95 % confidence interval) in EBs of this strain. These findings are in agreement with the hypothesis that the ORF1-encoded protein is involved in, but not essential for, plasmid replication and control of copy number.
Inhibitory mechanisms in autism spectrum disorders: typical selective inhibition of location versus facilitated perceptual processing
Authors: Brian J.A. , Tipper S.P. , Weaver B. , Bryson S.E.
Published: March 2005

Background:  This study examined the inhibitory control mechanisms of selective attention in autism spectrum disorders. Two issues were engaged: First, we extend previous findings of normal inhibition of distractor identity in autism by examining whether inhibition of spatial location is also spared. The second issue concerns the selectivity of inhibition. In non‐clinical participants inhibition is selectively directed to the properties of the distractor that compete for the control of action; we examined whether individuals with autism also show normal selectivity of inhibition.

Method:  A negative priming task was used to examine selective spatial inhibition in participants with autism relative to matched non‐clinical controls.

Results:  We discovered that inhibition of distractor spatial location is within normal limits in autism, as is the ability to selectively direct inhibition to task‐relevant stimulus features. In addition, we unexpectedly found that the irrelevant perceptual feature of colour produced a facilitation effect in autism, which has not been observed previously in typical controls.

Conclusions:  Evidence of colour facilitation implicates more fluent, but presumably less adaptive, perceptual processes in autism.
Distinct patterns in alpine vegetation around dens of the Arctic fox
Authors: Henrik Bruun Hans , Österdahl Sofia , Moen Jon , Angerbjörn Anders
Published: March 2005

The arctic fox Alopex lagopus excavates its dens in gravely ridges and hillocks, and creates a local environment quite distinct from the surrounding tundra or heath landscape. In northern Sweden, the vegetation of 18 dens of the arctic fox was investigated, as well as reference areas off the dens but in geologically and topographically similar locations. The species composition showed considerable differences between den and reference areas, with grasses and forbs occurring more abundantly on the dens, and evergreen dwarf‐shrubs occurring more in reference areas. The effect of the foxes’ activities is thought to be either through mechanical soil disturbance, or through nutrient enrichment via scats, urine, and carcasses. This was expected to result in differences in plant traits with key functional roles in resource acquisition and regeneration, when comparing dens with reference areas. We hypothesised that the community mean of specific leaf area (SLA) would differ if nutrient enrichment was the more important effect, and that seed weight, inversely proportional to seed number per ramet and hence dispersal ability, would differ if soil disturbance was the more important effect. Specific leaf area showed a significant difference, indicating nutrient enrichment to be the most important effect of the arctic fox on the vegetation on its dens. Arctic foxes act as ecosystems engineers on a small scale, maintaining niches for relatively short‐lived nutrient demanding species on their dens in spite of the dominance of long‐lived ericaceous dwarf‐shrubs in the landscape matrix. Thus, foxes contribute to the maintenance of species richness on the landscape level.
Antenatal care in the capital city of Cambodia: Current situation and impact on obstetric outcome
Authors: Fujita Noriko , Matsui Mitsuaki , Srey Sopha , Po Chin Samuth , Uong Sokhan , Koum Kanal
Published: March 2005

Aims: To analyze the situation of antenatal care (ANC) attendance in the capital of Cambodia, Phnom Penh, and the effect of ANC attendance on delivery and newborn outcome, in order to establish a strategy for ANC in the national reproductive health program in Cambodia.

Methods: This was a health facility‐based retrospective cohort study. Background factors (education, household income, and parity) were obtained through interview, and obstetric information (cesarean section, low birth‐weight, and maternal complications) were collected from the medical records of women who delivered during 1 month at all the public and private health facilities in Phnom Penh. Relations were analyzed between the number of ANC visits, background factors, and obstetric outcome.

Results: A total of 1204 responses were received from Phnom Penh residents, representing 84% of the estimated number of deliveries in the city. Of these, 89% were from public health facilities. Low educational level, low household income, and multiparity were risk factors for ANC attendance. There was no association between the number of ANC attendances and obstetric outcome.

Conclusions: Our study has shown that Phnom Penh residents have good access to ANC and delivery care. Low socioeconomic factors are risk factors to ANC. The number of ANC visits had no association with poor perinatal outcome, but further study on quality of ANC and its impact on obstetric outcome is needed. Within the limited resources, safe motherhood strategies need to be targeted to the rural area and to the poor in order to increase access to ANC and delivery care.
Pantoprazole provides rapid and sustained symptomatic relief in patients treated for erosive oesophagitis
Authors: Bochenek W. J. , Mack M. E. , Fraga P. D. , Metz D. C.
Published: March 2005

Background : Effective symptom control is a primary concern of most heartburn suffers.

Aim : To compare the safety and efficacy of pantoprazole, placebo and the H2 antagonist nizatidine in relieving symptoms in patients with erosive oesophagitis.

Methods : Data from two randomized, double‐blind studies were pooled. Patients received pantoprazole 10, 20 or 40 mg, or placebo daily (study 1, n = 603), or pantoprazole 20 or 40 mg daily or 150‐mg nizatidine b.d. (study 2, n = 243) for either 4 or 8 weeks. Endoscopy was performed at baseline, week 4 and week 8. Persistent absence of symptoms was defined as the first day that no symptoms were reported by the patient on that day or any subsequent study day.

Results : A significantly higher percentage (P < 0.05) of pantoprazole patients reported elimination of all symptoms by week 8. Daytime heartburn, night‐time heartburn and regurgitation were significantly better controlled with pantoprazole (with a dose–response at most time‐points). Absence of symptoms was a powerful predictor of healing; presence of symptoms correlated poorly.

Conclusion : Pantoprazole is more effective than placebo or nizatidine for controlling heartburn and acid regurgitation in patients with erosive oesophagitis. Relief of GERD symptoms is highly predictive of healing of erosive oesophagitis at 4 and 8 weeks.
Symptomatic gastro‐oesophageal reflux, arousals and sleep quality in patients undergoing polysomnography for possible obstructive sleep apnoea
Authors: Guda N. , Partington S. , Vakil N.
Published: March 2005

Introduction: Nocturnal acid reflux is common and could disturb sleep by causing arousals that fragment sleep.

Aim: To determine the prevalence of gastro‐oesophageal reflux symptoms and their association with arousals, stages of sleep and quality of life in patients undergoing evaluation for excessive daytime sleepiness and obstructive sleep apnoea.

Methods: Ninety‐four consecutive patients with excessive daytime sleepiness were prospectively studied. Patients completed the gastrointestinal symptom rating scale, a validated symptom questionnaire for reflux disease and a disease‐specific quality of life questionnaire, the sleep apnoea quality of life index and then underwent overnight polysomnography, which was read in a blinded manner.

Results: There were 40 males and 54 females with a mean age of 47 ± 13 years. Reflux symptoms were present in 63 of the 94 (67%) patients. Patients with reflux symptoms had significantly more arousals from sleep 43 ± 70/h than those without (20 ± 24/h;P =0.03). The sleep duration during the second stage of sleep was shorter (44 ± 21%) for those with reflux symptoms than those without (52 ± 12%;P = 0.03). Patients with reflux spent significantly shorter periods in stage II sleep (44 ± 21%) than those without (52 ± 12%;P = 0.03). The sleep‐related quality of life score in patients with gastro‐oesophageal reflux (3.1 ± 1.1) was significantly lower than in patients without reflux (3.7 ± 1.0;P = 0.02). Regression analysis demonstrated a significant inverse correlation between quality of life and reflux symptom score (P =0.002) and total spontaneous arousals (P = 0.04).

Conclusions: Gastro‐oesophageal reflux is common in patients with sleep disorders, is associated with increased arousal, decreased durations spent in the deeper stages of sleep and poorer sleep‐related quality of life.
Frequency of the canine leucocyte adhesion deficiency (CLAD) mutation among Irish red setters in Germany
Authors: Pfeiffer I. , Brenig B.
Published: March 2005

Canine leucocyte adhesion deficiency (CLAD) is an autosomal recessive hereditary disease occurring among Irish red setters. The genetic defect causative for this disorder was recently identified as a missense mutation in theITGB2gene. Irish red setters with one copy of the mutant gene appear normal, while dogs with two copies of the mutant gene manifest the disease. The present report describes the analysis of the single nucleotide polymorphism in 289 Irish red setters by DNA sequencing. The frequency of CLAD carriers in Germany is 11%.
Architectural constraint in fruit production of Crotalaria spectabilis (Fabaceae)
Authors: PRITCHARD KATIE , EDWARDS WILL
Published: March 2005

We tested the relative influences of plant architecture and whole plant resources as mechanisms for setting flower and fruit production in Crotalaria spectabilis Roth. (Fabaceae). We also examined the effects of plant architecture and competition between flowers and whether low probability of female function in late flowers was associated with an increased allocation to male function. In control plants, we found a significant relationship between the cross‐sectional area of a stem supplying an inflorescence and the number of flowers and fruits produced. Furthermore, the location of successful fruit production was non‐random and heavily biased to early opening flowers. In contrast, we found no evidence that fruit to flower ratios in C. spectabilis were altered as a result of environmental resources. The removal of early opening flowers was associated with fruit production in later opening ones, indicating that the capability of producing fruits did not differ between flowers, independent of their time of opening. In conjunction with non‐random transition probabilities, allocation to male function was greater in later opening flowers than in early opening ones. Taken together, our results support the hypothesis that plant architectural limitations and inflorescence developmental ontogeny are principal determinants of how many fruits will be produced and where fruit production will occur, and that these factors influence sex allocation between flowers within inflorescences.
Life‐history monographs of Japanese plants. 2: Trillium camschatcense Ker‐Gawl. (Trilliaceae)
Authors: OHARA MASASHI , KAWANO SHOICHI
Published: March 2005

The life‐history characteristics and demography of Trillium camschatcense (Trilliaceae) were studied and are described here. T. camschatcense, a typical polycarpic perennial, is a representative of the spring plants growing in temperate broad‐leaved deciduous forests in the lowlands of Hokkaido and northern Honshu, and adjacent Far East regions. Flowering takes place in early to late April. T. camschatcense typically has three white petals and three sepals, is primarily pollinated by bumblebees (Bombus and Andrena spp.) and beetles (Carpophilus and Aphthonaltica spp.), with pollen/ovule ratios of 2200, and is a conditional outbreeder. Occasional inbreeders are also known in the north‐eastern populations of Hokkaido. Capsules mature in late summer, late July to August. Light‐brown seeds, 2–3 mm long, with a soft juicy elaiosome containing sugars such as fructose, glucose and saccharose attracts ants and beetles, but only ants are effective dispersal agents for Trillium seeds. Our long‐term monitoring study has continued for 25 years from 1980 to 2004, and most of the flowering individuals turned out to be extremely long‐lived, at ages of well over 20 years. Notably, frequent switches in growth stages occur, not only proceeding from the single‐leaf sterile stage to the three‐leaved sterile‐stage but also reverting to earlier growth stages.
Clinical and pathological responses of progestin therapy for non‐atypical endometrial hyperplasia: A prospective study
Authors: Rattanachaiyanont Manee , Angsuwathana Surasak , Techatrisak Kitirat , Tanmahasamut Prasong , Indhavivadhana Suchada , Leerasiri Pichai
Published: March 2005

Aims: To evaluate the clinical and pathological responses and factors predicting non‐responders to various progestins currently prescribed for the treatment of non‐atypical endometrial hyperplasia.

Methods: A prospective observational study was conducted in the Gynecologic Endocrinology Unit, Faculty of Medicine, Siriraj Hospital, Thailand, from 1998 to 2003. A 6‐month course of progestin therapy was offered to all patients. The clinical response was evaluated from the vaginal bleeding pattern during the first 4 months of treatment. The pathological response was evaluated from the histopathology of the endometrium after completion of the 6‐month therapy.

Results: Of 250 registered patients, the number of cases qualified for the evaluation of the clinical and pathological response were 198 and 134 cases, respectively, revealing the overall clinical and pathological response rates of 93.4% and 92.5%, respectively. Among 13 clinical non‐responders, 84.6% might have associated pelvic pathology. Among 10 pathological non‐responders, three had surgical treatment, and progressive disease was found in one case. Significant factors predicting clinical non‐responders included a history of prior bleeding (odds ratio [OR] = 8.79, 95% confidence interval [CI] = 1.63, 47.53), the presence of associated pelvic pathology (OR = 25.52, 95% CI = 3.21, 203.01), and treatment using progestins other than medroxyprogesterone acetate. Factors predicting pathological non‐responders were not statistically significant.

Conclusions: The current regimens of progestin therapy for non‐atypical endometrial hyperplasia have high response rates. Patients who fail to have a clinical response should be evaluated for associated pelvic pathology. Follow‐up endometrial biopsy should be offered to the patients, because 7.5% have persistent or progressive lesions, necessitating aggressive treatment.
Cigarette smoking and the risk of ovarian cancer in the Japanese population: Findings from the Japanese Collaborate Cohort study
Authors: Niwa Yoshimitsu , Wakai Kenji , Suzuki Sadao , Tamakoshi Koji , Lin Yingsong , Yatsuya Hiroshi , Kondo Takaaki , Nishio Kazuko , Yamamoto Akio , Tokudome Shinkan , Hamajima Nobuyuki , Toyoshima Hideaki , Tamakoshi Akiko ,   for the JACC Study Group
Published: March 2005

Aim:The many studies into the relation between cigarette smoking and the risk of ovarian cancer have produced inconsistent results. Here we investigated this relation using data from the Japan Collaborative Cohort Study for Evaluation of Cancer Risk, initiated in 1988.

Methods:A self‐administered questionnaire on smoking habits and other risk factors for cancer was completed by 34 639 Japanese women. After 7.6 years of follow up, 39 cases of ovarian cancer were available  for analyses. Cox proportional‐hazards models were used to compute relative risks (RR) and to adjust for confounders.

Results:Relative to those who had never smoked, the RR of ovarian cancer were 1.63 (95% confidence interval [CI] = 0.21–12.50) for former smokers and 2.27 (95% CI = 0.85–6.08) for current smokers. Among current smokers, the RR were 1.48 (95% CI = 0.20–10.92), 5.56 (95% CI = 1.68–19.06), and 1.86 (95% CI = 0.25–14.30) among women who smoked <10, 10–19, and at least 20 pack‐years ([number of cigarettes smoked per day/20] × number of years subject has smoked), respectively, relative to those who had never smoked. A test for trend was statistically significant (P = 0.044).

Conclusions:These data indicate that cigarette smoking increases the risk of developing ovarian cancer in the Japanese population.
Evolutionary consequences of gender plasticity in genetically dimorphic breeding systems
Authors: Delph Lynda F. , Wolf Diana E.
Published: March 2005

A functional view of gender helps evolutionary biologists evaluate the mechanisms underlying breeding‐system evolution. Evolutionary pathways from hermaphroditism to dioecy include the intermediate breeding systems of gynodioecy and androdioecy. These pathways start with the invasion of unisexual mutants, females or males, respectively, followed by alteration of the hermaphrodites to allocate more to the sexual function that the unisexuals lack. Eventually, hermaphrodites become unisexual and dioecy has evolved. Some species evolving along these pathways stop short of completing this second step, or even revert back from dioecy. We evaluate the hypothesis that gender plasticity is involved in these transitions to and from dioecy. Evidence from studies of subdioecious species that have evolved along the gynodioecy pathway suggests that gender plasticity occurs and stabilizes subdioecy by lowering the cost of producing seed. Factors influencing species evolving toward androdioecy, or reverting to androdioecy from dioecy, appear to be more varied and include reproductive assurance, herbivory and gender plasticity. In general, gender specialization appears to be favored in resource‐poor environments regardless of which pathway is taken to dioecy.
Health Policy Roundtable—View from the State Legislature: Translating Research into Policy
Authors: Folz Christina E.
Published: March 2005

This roundtable examines the role of health services research from the perspective of the state legislature. Four research and policy experts—each of whom is a current or former legislator—explore how research can be translated effectively into state health policy, and how researchers and legislators can communicate clearly with one another and engage in productive collaborations.
How Much Is Postacute Care Use Affected by Its Availability?
Authors: Buntin Melinda Beeuwkes , Garten Anita Datar , Paddock Susan , Saliba Debra , Totten Mark , Escarce José J.
Published: March 2005

Objective. To assess the relative impact of clinical factors versus nonclinical factors—such as postacute care (PAC) supply—in determining whether patients receive care from skilled nursing facilities (SNFs) or inpatient rehabilitation facilities (IRFs) after discharge from acute care.

Data Sources and Study Setting. Medicare acute hospital, IRF, and SNF claims provided data on PAC choices; predictors of site of PAC chosen were generated from Medicare claims, provider of services, enrollment file, and Area Resource File data.

Study Design. We used multinomial logit models to predict PAC use by elderly patients after hospitalizations for stroke, hip fractures, or lower extremity joint replacements.

Data Collection/Extraction Methods. A file was constructed linking acute and postacute utilization data for all medicare patients hospitalized in 1999.

Principal Findings. PAC availability is a more powerful predictor of PAC use than the clinical characteristics in many of our models. The effects of distance to providers and supply of providers are particularly clear in the choice between IRF and SNF care. The farther away the nearest IRF is, and the closer the nearest SNF is, the less likely a patient is to go to an IRF. Similarly, the fewer IRFs, and the more SNFs, there are in the patient's area the less likely the patient is to go to an IRF. In addition, if the hospital from which the patient is discharged has a related IRF or a related SNF the patient is more likely to go there.

Conclusions. We find that the availability of PAC is a major determinant of whether patients use such care and which type of PAC facility they use. Further research is needed in order to evaluate whether these findings indicate that a greater supply of PAC leads to both higher use of institutional care and better outcomes—or whether it leads to unwarranted expenditures of resources and delays in returning patients to their homes.
Acidic Conditions Enhance Bactericidal Effects of Sodium Bisulfite on Helicobacter pylori
Authors: Murano Akiyuki , Morinaga Naoko , Iwamaru Yoshifumi , Yahiro Kinnosuke , Tagashira Motoyuki , Moss Joel , Tanzawa Hideki , Noda Masatoshi
Published: March 2005

Background.  The Brucella broth medium, which is often used for the cultivation of microaerobic bacteria including Helicobacter pylori. It contains sodium bisulfite to decrease oxygen content in the medium. The growth of H. pylori, however, is inhibited by sodium bisulfite. In this study, the effect of sodium bisulfite was compared with several antioxidants and quantified under acidic conditions, mimicking the gastric environment.

Methods.  Growth of H. pylori in the presence of several antioxidants was evaluated at OD655 nm. Effect of sodium bisulfite on H. pylori under acidic conditions was evaluated by measuring colony forming units (cfu).

Results.  Under neutral conditions, sodium bisulfite was a more potent suppressor of H. pylori. Resveratrol, a polyphenol found in wine, exhibited the most potent inhibitory activity. To quantify the effect of sodium bisulfite on H. pylori under acidic conditions, the bacteria were grown at 37 °C for 30 minutes in 0.15 mol/l HCl/KCl (pH 2.0) with or without urea and sodium bisulfite. Sodium bisulfite (0.5 mmol/l) did not affect the viability at neutral pH 7.0, however, it killed H. pylori under acidic conditions, even if urea, the key substance enabling H. pylori to survive under acidic conditions, was present. The bacteria, which had been incubated under acidic conditions in the presence of urea, could survive a subsequent 30 minute‐incubation at pH 2.0 without urea. Presence of sodium bisulfite, however, in the subsequent 30 minute‐incubation, killed the bacteria.

Conclusions.  The bactericidal effect of sodium bisulfite on H. pylori was greater under acidic conditions and independent of urease activity.
Serial plasma lactate concentrations in 68 puppies aged 4 to 80 days
Authors: McMichael Maureen A. , Lees George E. , Hennessey Jennifer , Sanders Mary , Boggess May
Published: March 2005

Objective:To determine a reference range for venous blood lactate concentrations in healthy neonatal dogs.

Design:A prospective cohort study.

Setting:All work was conducted at the College of Veterinary Medicine, Texas A&M University.

Animals:Clinically healthy dogs: 68 puppies and 30 adults.

Measurements and main results:A blood sample was collected from each puppy into lithium heparin via jugular venipuncture at 4, 10, 16, 28, 70, and 80 days of age. A single venous sample was collected from each adult dog. Lactate concentration in each sample was measured immediately using an automated analyzer. Two hundred seventy‐seven blood samples were analyzed. Blood lactate concentrations of adult dogs were 1.80±0.84 mmol/L (mean±SD). Mean blood lactate concentrations of puppies were significantly higher at 4, 10, 16, and 28 days of age compared with those of adult dogs. The reference range for lactate concentration for puppies at 4 days of age was 1.07–6.59, and for the puppies from 10 to 28 days of age was 0.80–4.60.

Conclusions:Assessment of perfusion can be challenging in neonates due to normal physiologic variation and small size. Measurement of lactate is rapid, minimally invasive, and has potential to be a useful marker of perfusion in neonatal dogs. However, lactate concentrations of neonatal dogs in this study were significantly higher than those of adult dogs. Reference ranges for venous lactate concentrations in adult dogs should not be used for puppies younger than 70 days of age.
Tumour angiogenesis: vascular growth and survival
Authors: GIATROMANOLAKI ALEXANDRA , SIVRIDIS EFTHIMIOS , KOUKOURAKIS MICHAEL I.
Published: March 2005

Angiogenesis starts at the edge of a malignant epithelial tumour concurrently with tumour cell invasion and stromatogenesis, i.e. the formation of specific connective tissue stroma amenable to easy penetration by endothelial and tumour cells. However, as the tumour continues its growth, the edge becomes the inner tumour area, and a new invading tumour front is formed by the multiplying malignant cells which outflank the initial edge. This process, which repeats itself again and again, forms the “relay race” model of tumour vascular growth and regression. At the heart of the tumour unfavourable environmental conditions prevail – hypoxia, acidity, lack of nutrients, failure of waste removal, and apoptosis rather than proliferation. Blood vessels and tumour cells are greatly decreased, but do not vanish, as tumour cells are shifting to anaerobic glycolysis, and blood vessels are turning into anti‐apoptotic pathways – vascular survival ability (VSA). Thus, assessing vascular density (VD) by simply counting “hot spots” at the edge of a tumour, where conditions are most favourable, is futile; it may reflect tumour angiogenic activity (TAA), but is not representative of genuine tumour vasculature. By combining vessel counts at the invading tumour front with those of the inner tumour areas a complete picture of tumour VD can be achieved. The thus formed four patterns of vascularization, designated as “edvin” (edge vsinner tumour area), are: edvin 1: low TAA/low VSA; edvin 4: high TAA/high VSA; edvin 2: low TAA/high VSA; and edvin 3: high TAA/low VSA. It is expected that this scheme will prove useful in the field of chemoradiotherapy and anti‐angiogenic treatment.
Lymphangiogenic growth factors as markers of tumor metastasis
Authors: STACKER STEVEN A. , WILLIAMS RICHARD A. , ACHEN MARC G.
Published: March 2005

Understanding the complex process of tumor metastasis is a problem which has challenged both clinician and scientist for well over 100 years. Defining molecular markers which reflect the metastatic potential of a tumor has also proved elusive. Recently, members of the vascular endothelial growth factor (VEGF) family of glycoproteins have been demonstrated to be potent mediators of both blood vessel and lymphatic vessel formation in the context of tumor biology. Experimental studies in animal models combined with extensive clinicopathological data provide a compelling case indicating that members of the VEGF family play a key role in the formation of metastases in a broad range of solid tumors. The question of whether VEGF signaling pathways can now serve as therapeutic targets alone, or in combination with other forms of anti‐cancer agents, needs to be addressed.
Embryo Aneuploidy Screening for Unexplained Recurrent Miscarriage: A Minireview
Authors: Rubio Carmen , Pehlivan Tugce , Rodrigo Lorena , Simón Carlos , Remohí Jose , Pellicer Antonio
Published: March 2005

Problem:  The aim of this study was to investigate the incidence of chromosomal abnormalities in unexplained recurrent miscarriage (RM) patients and assess the role of pre‐implantation genetic diagnosis (PGD) in preventing subsequent pregnancy loss and improving pregnancy outcome.

Method of Study:  Pre‐implantation genetic diagnosis was performed in 241 RM cycles and in 35 cycles in patients undergoing PGD for sex‐linked diseases (control group). Chromosomes 13, 16, 18, 21, 22, X and Y were analysed by fluorescence in situ hybridization.

Results:  The implantation and pregnancy rates in RM patients were 26.4 and 36.5% versus 20.6 and 29.0% in the control group, respectively. The percentage of abnormal embryos was significantly increased in RM patients compared with controls.

Conclusions:  Recurrent miscarriage is associated with a higher incidence of chromosomally abnormal embryos. In vitro fertilization (IVF) plus PGD is an important step in the management of these couples.
Effect of hydration and dehydration cycles on seed germination of Aster kantoensis (Compositae)
Authors: Kagaya Mitsuko , Tani Takashi , Kachi Naoki
Published: March 2005

Seeds of Aster kantoensis Kitamura (Compositae) were experimentally exposed to different cycles of hydration and dehydration: 3H1D (cycles of 3-d hydration and 1-d dehydration periods), 2H3D, 2H1D, 1H3D, 1H2D, and 1H1D. Under continuous hydration (control), all viable seeds germinated within 9 d. However, all viable seeds exposed to the 3H1D, 2H3D, and 2H1D cycles germinated within 36, 50, and 36 d of the start of the experiment, respectively. Not all viable seeds exposed to the 1H3D, 1H2D, and 1H1D cycles germinated during the experimental period. Compared with the control, the number of days required for 50% germination increased in seeds exposed to the hydrationdehydration treatments except for those seeds exposed to the 3H1D and 2H1D cycles. In addition, seeds treated with a 1-d hydration period required a larger number of cumulative hydration days for 50% germination than those seeds exposed to one of the other three treatments or the control. These results indicate that sporadic germination of A. kantoensis seeds during an extended period of several months in the gravelly flood plain where they are found results because the dispersed seeds are exposed to various cycles of hydration and dehydration depending upon the rainfall pattern and spatial heterogeneity of evaporation rates at the sand surface resulting from shading by gravel.Key words: Aster kantoensis, dehydration tolerance, gravelly flood plain, hydrationdehydration cycles, seed germination.
Assessing the potential for stock enhancement in the case of the Chesapeake Bay blue crab (Callinectes sapidus)
Authors: Davis Jana LD , Young-Williams Alicia C , Hines Anson H , Zohar Yonathan
Published: March 2005

In certain cases of severely depleted fishery stocks, combining stock enhancement with traditional management techniques may be a useful way of returning stocks to an exploitable size. The Chesapeake Bay stock of blue crabs (Callinectes sapidus) has declined over the past decade and appears to be recruitment-limited, making it an appropriate candidate for enhancement efforts. This study serves as a first step in determining whether large-scale enhancement of blue crab stocks is feasible. Four hatchery-raised cohorts of 4000  10 000 (25 000 in total) juvenile (630 mm carapace width, 5870 days old) crabs were released in upper Chesapeake Bay coves. Sixty days after release, these crabs constituted 22%79% of all crabs in the hatchery-crab size range (corresponding to an enhancement level of 28%366%). Crabs released earlier in the summer reached maturity at the age of 6 months, younger than their wild counterparts. Estimated survivorship to maturity was 16%20% for early-released crabs and 515% for late-released crabs. Late-released crabs, like wild crabs, had to overwinter before becoming mature. Our study suggests ways to improve success of hatchery-raised individuals that can be broadly applied across taxa. The results also contribute specifically to determining whether large-scale stock enhancement is possible in the case of the Chesapeake Bay blue crab.
Second-order relativistic corrections for the S(L=0) states in one- and two-electron atomic systems
Authors: Frolov Alexei M , Mitelut Catalin C , Zhong Zheng
Published: March 2005

An analytical approach is developed to compute the first- (~α2) and second-order (~α4) relativistic corrections in one- and two-electron atomic systems. The approach is based on the reduction of all operators to divergent (singular) and nondivergent (regular) parts. Then, we show that all the divergent parts from the differentmatrix elements cancel each other. The remaining expression contains only regular operators and its expectation value can be easily computed. Analysis of the S(L = 0) states in such systems is of specific interest since the corresponding operators for these states contain a large number of singularities. For one-electron systems the computed relativistic corrections coincide exactly with the appropriate result that follows from the Taylor expansion of the relativistic (i.e., Dirac) energy. We also discuss an alternative approach that allows one to cancel all singularities by using the so-called operator-compensation technique. This second approach is found to be very effective in applications of more complex systems, such as helium-like atoms and ions, H+2-like ions, and some exotic three-body systems.
Thermal conductivity of base-course materials
Authors: Côté Jean , Konrad Jean-Marie
Published: March 2005

This paper presents the results of a comprehensive laboratory study on the thermal conductivity of dense and broadly graded coarse base-course materials used in pavements. Materials were selected from eight quarries along the axis of the St. Lawrence River to include a variety of samples of different geological origins. Nearly 200 tests were performed in a thermal conductivity cell using Pyrex heat flux meters to characterize the relationships between the thermal conductivity of unfrozen and frozen samples and the waterice content. Sixteen tests were also performed on solid rock cylinders to characterize the influence of mineralogy on the thermal conductivity of solid particles from the selected quarries. The most widely used empirical prediction models for thermal conductivity of soils from the literature were found inappropriate to estimate the thermal conductivity of base-course materials. An improved model using the geometric mean method to compute the thermal conductivity for the solid particles and the saturated materials, a modified form of the geometric mean method to predict the thermal conductivity of dry materials, and empirical relationships to assess the normalized thermal conductivity of unfrozen and frozen base-course materials are presented. This new model predicted well the thermal conductivity for more than 150 unfrozen and frozen coarse sand and gravel samples from the literature. A step by step methodology is proposed to assess the thermal conductivity of base-course materials.Key words: base course, porosity, degree of saturation, mineralogy, unfrozenfrozen, thermal conductivity.
Rate-controlled cone penetration tests in permafrost
Authors: Buteau Sylvie , Fortier Richard , Allard Michel
Published: March 2005

Cone penetration tests (CPTs) were carried out in the summers of 1999 and 2000 in a permafrost mound near Umiujaq, in northern Quebec, Canada, to study the cryostratigraphy and assess the creep behaviour of permafrost. A new linear pushing system using an actuator technology was specifically designed and developed to accurately control the penetration rate of the cone in the permafrost. This system has a load capacity of about 113 kN at a maximum penetration rate of 1.5875 cm/s and a stroke of 120 cm and can provide constant penetration rates as low as 4 × 106 cm/s. It can be disassembled in pieces for easy hand transport and use in remote locations. Two different types of CPT were performed in the permafrost mound: stratigraphic profiling and creep test. The first type is a quasi-static CPT at a penetration rate of 0.1 cm/s, providing a stratigraphic profile of permafrost in terms of the measurement of penetrometer sensors as a function of depth. The second type is a series of quasi-static CPTs at incremental rates of penetration, from 104 to 102 cm/s, carried out in a homogeneous layer to study the creep behaviour of permafrost. Five distinct zones (unfrozen and frozen active layer, permafrost, cryotic but unfrozen ground, and perennially noncryotic ground) can be identified in the stratigraphic profiles. The creep exponents calculated from the creep tests range from 12 to 35 for the ice-poor frozen active layer and from 4 to 11 for the ice-rich permafrost. Key words: cone penetration test, permafrost, rate-controlled, creep behaviour, cryostratigraphy.
FRET-based voltage probes for confocal imaging: membrane potential oscillations throughout pancreatic islets
Authors: Kuznetsov Andrey , Bindokas Vytautas P. , Marks Jeremy D. , Philipson Louis H.
Published: March 2005

Insulin secretion is dependent on coordinated pancreatic islet physiology. In the present study, we found a way to overcome the limitations of cellular electrophysiology to optically determine cell membrane potential ( Vm) throughout an islet by using a fast voltage optical dye pair. Using laser scanning confocal microscopy (LSCM), we observed fluorescence (Förster) resonance energy transfer (FRET) with the fluorescent donor N-(6-chloro-7-hydroxycoumarin-3-carbonyl)-dimyristoylphosphatidyl-ethanolamine and the acceptor bis-(1,3-diethylthiobarbiturate) trimethine oxonol in the plasma membrane of essentially every cell within an islet. The FRET signal was approximately linear from Vm −70 to +50 mV with a 2.5-fold change in amplitude. We evaluated the responses of islet cells to glucose and tetraethylammonium. Essentially, every responding cell in a mouse islet displayed similar time-dependent changes in Vm. When Vm was measured simultaneously with intracellular Ca2+, all active cells showed tight coupling of Vm to islet cell Ca2+ changes. Our findings indicate that FRET-based, voltage-sensitive dyes used in conjunction with LSCM imaging could be extremely useful in studies of excitation-secretion coupling in intact islets of Langerhans.
A Structural Analysis of the Value-Added Effects of Enterprises: A Re-Assessment
Authors: Doamekpor Francois K.
Published: March 2005

This paper uses structural equation modeling to examine the effects of state-owned enterprises on the growth of output. Using a covariance matrix derived from cross-sectional data, it is shown through LISREL estimation modeling that total effects on output may not be completely negative as previously observed under other procedures. However, the use of the variable in an ordinary least squares framework in combination with other endogenous variables produces weak and negative results.
Comparing Moral Values in Western European Countries between 1981 and 1999. A Multiple Group Latent-Class Factor Approach
Authors: Moors Guy , Wennekers Charlotte
Published: March 2005

This paper compares moral values in 12 European countries based on data from three waves of the European Values Survey: 1981, 1990, and 1999. We question the validity of comparisons across cultures and in time if the structural equivalence in the measurement of values is not tested. A procedure is suggested to research equivalence in measurement within a latent-class factor approach. Multiple group analyses revealed that assuming a homogeneous measurement model is not justified. Rather patterns of partial homogeneity emerged in which country and period influenced moral issues independently from the effect of two group variables on the latent-class factors. As a result, country differences generally decreased when direct effects of country on the items were introduced, however without contradicting the comparisons from the homogeneous measurement model. Period differences decreased less after allowing direct effects of the former group variable on the items.
Global Transformation and Local Counter Movements: The Prospects for Democracy Under Neoliberalism
Authors: Udayagiri Mridula , Walton John
Published: March 2005

This article compares Mexico and India’s experiences with neoliberalism to propose that the collapse of the developmentalist state generates countermovements. In both nations, neoliberalism is associated with the decline of the one-party dominant system, and a restructuring of civil society. Variations emerge in the timing of democratization in these countries. In India, democratization preceded neoliberal reforms, whereas in Mexico democratization followed neoliberal reforms, but in both cases democratization mitigates the effects of neoliberalism on civil society. Conclusions drawn from the comparative analysis of Mexico and India concur with Karl Polanyi’s proposition that there is a double movement of marketization and protectionist countermovements. The case studies suggest a pattern to these countermovements. Actors are confronted abruptly with threats to their well-being; not only economic threats but also environmental, political, and symbolic threats. The threatened value in each case is a former entitlement, typically a form of protection ensured by the state. Thus, even in the presence of countermovements, neoliberalism mediates a divergence of state and civil society relationships creating uncertain futures for democratic possibilities.
Tobacco Use in Intimate Spaces: Issues in the Study of Couple Dynamics
Authors: Bottorff Joan L. , Kalaw Cecilia , Johnson Joy L. , Stewart Miriam , Greaves Lorraine
Published: March 2005

Few guidelines exist for using qualitative research to examine couple dynamics in contexts complicated by strong social stigmas and wide-ranging patterns of interpersonal relationships. The purpose of this article is to describe the methodological and ethical issues that arose in an ongoing qualitative study focused on tobacco reduction in the context of couple relationships, and the strategies undertaken to deal with these challenges. The authors discuss their experiences with the following: recruitment in the context of social stigma and the potential for intracouple coercion, data collection and the implications of uncovering intimate dimensions of couples’ lives, the impact of the research process on mothers’ vulnerability, and the challenges of capturing shared, “dyad” experiences. These issues point to unique challenges in conducting qualitative research with couples and families and provide a useful base for similar studies.
Support Network Transformations in the First Stages of the Caregiver’s Career
Authors: Carpentier Normand , Ducharme Francine
Published: March 2005

The purpose of this article is to propose a method to facilitate analysis of the processes involved in the transformation of support networks for caregivers of persons with dementia. The authors are particularly interested in the preliminary phases of the caregiver’s career: the initial period ranging from the first manifestations of dementia to the confirmation of a diagnosis. This method combines the social network approach with narrative analysis. The authors discuss two cases to illustrate the concepts of density and clique to explain the maintenance and dissolution of the caregiver’s supportive relationships. This method shows significant potential, in that it will help researchers explore social mechanisms related to the development of supportive relationships.
An Application of the Transactional Model to the Analysis of Chronic Illness Narratives
Authors: Lee Andrea M. , Poole Gary
Published: March 2005

The authors’ aim in this study was to describe the chronic illness experience and its relationship to the concept to finding meaning. They conducted interviews using a narrative approach with 15 adults experiencing various chronic illnesses and analyzed narrative data using a combination of holistic-content and categorical-content approaches. The three major categories were the context of the chronic illness experience, personal reactions, and coping efforts. These categories were best interpreted in terms of a transactional model. The authors categorized finding meaning under cognitive coping strategies and described it as a strategy that was part of a larger coping repertoire.
Virtually He@lthy: The Impact of Internet Use on Disease Experience and the Doctor-Patient Relationship
Authors: Broom Alex
Published: March 2005

In the current study, the author explores the complex effects and contradictory roles of the Internet as a source of empowerment and control, and as a site of “risk management.” Drawing on a study of the Internet usage of Australian men with prostate cancer, the author investigates how access to information and online support affects men’s experiences of disease and, in particular, the possible implications of Internet-informed patients for the doctor-patient relationship. The data reveal that accessing information and/or support online can have a profound effect on men’s experiences of prostate cancer, providing a method of taking some control over their disease and limiting inhibitions experienced in face-to-face encounters. However, it is also clear that some medical specialists view Internet-informed patients as a challenge to their power within medical encounters and, as a result, employ disciplinary strategies that reinforce traditional patient roles and alienate patients who use the Internet.
Women Living With a History of Physical and/or Sexual Abuse, Substance Use, and Mental Health Problems
Authors: Nehls Nadine , Sallmann Jolanda
Published: March 2005

Most researchers have studied physical and/or sexual abuse, substance use, and mental health problems separately or as a dual diagnosis, and from a theory-driven, empirical perspective. In this study, the authors examined these three phenomena together and from a phenomenological perspective. Thirty women each participated in an individual interview about living with a history of physical and/or sexual abuse, substance use, and mental health problems. Using a hermeneutic approach, a team of researchers analyzed the transcribed interview texts. They identified three themes: (a) being thrown: the cycle of abuse; (b) living life fearfully: a restricted world; and (c) helping: hearing my story. The results are significant, in that they challenge current assumptions underlying health care for women with histories of physical and/or sexual abuse, substance use, and mental health problems.