bluuebunny/crossref_metadata_2025 huggingface dataset:
Effect of the 5-HT2A/2C Receptor Agonist DOI on Female Rat Sexual Behavior
Authors: Rössler Anne-Sophie , Bernabé Jacque , Denys Pierre , Alexandre Laurent , Giuliano François
Published: March 2006

Introduction

Female rats display a repertoire of behaviors during a sexual encounter with a male, including sexually receptive (the lordosis response) and proceptive (darts and hops, and ear wigglings) behaviors.

Aim

We investigated the effects of subcutaneous injection of the 5-HT2A/2C receptor agonist (2,5-dimethoxy-4-idophenyl)-2-aminopropane hydrochloride (DOI) on sexual behaviors of ovariectomized female rat hormonally supplemented with estradiol benzoate (10 µg) and progesterone (250 µg).

Methods

Both female and male sexual behaviors were observed for 10 minutes (pretest). Then females were injected with the treatment and after a 10-minute delay replaced with the same male for a 30-minute mating test (posttreatment period).

Results

DOI (0.5 and 1 mg/kg) significantly increased the number of darts and hops/mounts. In contrast, no significant differences in ear wigglings/mounts were observed. In addition, DOI failed to modify sexual receptivity.

Conclusion

These data suggest that 5-HT2A/2C receptors are important in the regulation of female proceptivity.
What Can Prevalence Studies Tell Us About Female Sexual Difficulty and Dysfunction?
Authors: Hayes Richard D. , Bennett Catherine M. , Fairley Christopher K. , Dennerstein Lorraine
Published: March 2006

Introduction

Many recent studies have investigated the prevalence of female sexual difficulty/dysfunction.

Aim

Investigate female sexual difficulty/dysfunction using data from prevalence studies.

Methods

We reviewed published prevalence studies excluding those that had not included each category of sexual difficulty (desire, arousal, orgasm, and pain), were based on convenience sampling, or had a response rate <50% or a sample size <100.

Main Outcome Measures

For each study we used the prevalence of any sexual difficulty as the denominator and calculated the proportion of women reporting each type of difficulty. For each category of sexual difficulty we used the prevalence of that difficulty lasting 1 month or more as the denominator and calculated the proportion of difficulties lasting several months or more and 6 months or more.

Results

Only 11 of 1,248 studies identified met our inclusion criteria. These studies used different measures of sexual dysfunction, so generating a simple summary prevalence was not possible. However, we observed consistent patterns in the published data. Among women with any sexual difficulty, on average, 64% (range 16–75%) experienced desire difficulty, 35% (range 16– 48%) experienced orgasm difficulty, 31% (range 12–64%) experienced arousal difficulty, and 26% (range 7–58%) experienced sexual pain. Of the sexual difficulties that occurred for 1 month or more in the previous year, 62–89% persisted for at least several months and 25–28% persisted for 6 months or more. Two studies investigated distress. Only a proportion of women with sexual difficulty were distressed by it (21–67%).

Conclusions

Desire difficulty is the most common sexual difficulty experienced by women. While the majority of difficulties last for less than 6 months, up to a third persist for 6 months or more. Sexual difficulties do not always cause distress. Consequently, prevalence estimates will vary depending on the time frame specified by researchers and whether distress is included in these estimates.
Antibiotic Treatment Can Delay Ejaculation in Patients with Premature Ejaculation and Chronic Bacterial Prostatitis
Authors: El-Nashaar AbdelRahman , Shamloul Rany
Published: March 2006

Introduction

Premature ejaculation (PE) is regarded as the most common male sexual disorder. Previous studies reported that prostatic inflammation was highly prevalent in PE. However, the effect of antibiotic treatment of cases with PE and chronic prostatitis has not been extensively investigated.

Aim

To examine the effect of antibiotic treatment in delaying ejaculation in patients with PE and chronic prostatitis.

Methods

A total of 145 consecutive men attending of secondary premature ejaculation (SPE) were included in this study. Sequential microbiologic specimens were obtained from urine and prostatic fluid. Antibiotics were given for 1 month according to the results of their culture and sensitivity test. All patients were instructed to follow up with our clinic monthly for at least 4 months. At the end of the 4-month follow-up, another prostatic secretion analysis was performed.

Results

Based on expressed prostatic secretion culture and white blood cell (WBC) count, 94 (64.8%) were having chronic bacterial prostatitis. The remaining 51 (35.2%) patients had negative WBC count. Of the 94 patients with SPE and chronic bacterial prostatitis, 20 patients were left untreated and considered as a control group. All 74 patients with PE and chronic prostatitis continued the 1-month treatment duration. Following 1-month antibiotic treatment, all 74 patients with initially positive cultures had sterile final cultures (P < 0.05). Sixty-two (83.9%) patients showed increases in their ejaculatory latency time and reported good control of their ejaculation and were considered treatment responsive. None of the control group patients experienced any improvement either in their prostatic infection condition or in their ejaculation time. The follow-up of treatment-responsive patients (N = 62) revealed no recurrence of PE with negative prostatic culture.

Conclusion

Successful eradication of causative organisms in patients with PE and chronic prostatitis may lead to marked improvement in intravaginal ejaculatory latency time and ejaculatory control.
Stromal cell‐derived factor 1 (SDF1) genetic polymorphism in a sample of healthy individuals, seronegative individuals exposed to human immunodeficiency virus type 1 (HIV‐1) and patients infected with HIV‐1 from the Brazilian population
Authors: Reiche E. M. V. , Watanabe M. A. E. , Bonametti A. M. , Morimoto H. K. , Morimoto A. A. , Wiechmann S. L. , Matsuo T. , Miranda H. C. , Reiche F. V. , Oliveira K. B.
Published: March 2006

The interaction of viral and host factors is believed to determine not only the risk for initial human immunodeficiency virus type 1 (HIV‐1) acquisition but also the course of the infection. Genetic polymorphisms in the chemokine receptors and their ligands were related to the susceptibility and resistance to HIV‐1 infection. A polymorphism in the conserved 3′ untranslated region of the stromal cell‐derived factor‐1 (SDF1) gene, which encodes a ligand of the CXCR4 receptor, has been related either to delayed progression to AIDS or to rapid disease progression and death. Global, regional, and ethnic distributions of frequencies of SDF1 genotypes and of the SDF1–3′A allele vary significantly. Although the HIV‐1 epidemic is increasing in Brazil, little information about the frequencies of host genetic mutations related to HIV/AIDS resistance in the Brazilian population has been reported. To address this question, this study was carried out in order to determine the frequencies of the SDF1 polymorphism and the SDF1‐3′A allele on 1061 genomic DNA samples purified from peripheral blood cells of 136 healthy individuals (group 1), 147 HIV‐1‐exposed seronegative individuals (group 2), 161 HIV‐1‐infected asymptomatic individuals and with CD4+ T‐cells count  350 mm−3 (group 3), and 617 HIV‐1‐infected individuals with AIDS and/or CD4+ T‐cells count < 350 mm−3 (group 4). The frequencies of the SDF1–3′A homozygous mutation were 3.7%, 6.1%, 4.3%, and 5.3% among groups 1, 2, 3, and 4, respectively (P = 0.5120). The overall frequency of the SDF1‐3′A allele was 0. 1984 and did not differ among the four groups (P = 0.2744). The results underscore the global distribution of the SDF1 polymorphism and the hypothesis that the SDF1‐3′A allele, itself, may not be sufficient to prevent the risk of HIV‐1 infection and may be not related to the progression of the disease in the Brazilian population.
Excitation of g modes in Wolf—Rayet stars by a deep opacity bump
Authors: Townsend R. H. D. , MacDonald J.
Published: March 2006

We examine the stability of ℓ= 1 and ℓ= 2 g modes in a pair of nitrogen-rich Wolf–Rayet stellar models characterized by differing hydrogen abundances. We find that modes with intermediate radial orders are destabilized by a κ mechanism operating on an opacity bump at an envelope temperature of log T≈ 6.25. This ‘deep opacity bump’ is due primarily to L-shell bound–free transitions of iron. Periods of the unstable modes span ∼11–21 h in the model containing some hydrogen, and ∼3–12 h in the hydrogen-depleted model. Based on the latter finding, we suggest that self-excited g modes may be the source of the 9.8-h periodic variation of WR 123 recently reported by Lefèvre et al.
Mapping memorials for Edith Cavell on the colonial edge
Authors: Pickles Katie
Published: March 2006

Abstract:  This paper identifies and explains the pattern of memorialization in New Zealand for English nurse Edith Cavell, arguing that while the influences of empire and colonial mimicry provided a strong overarching framework, local context and parochial expressions were also strong at the colonial edge. In 1915 Cavell was executed by the occupying German forces in Belgium for her resistance work. The general transnational pattern of remembrance that resulted from the huge reaction to her death is explained. The paper then turns to the New Zealand memorialization of Cavell. With reference to monuments for other medical women, and addressing where Cavell does not appear in the landscape, the last section contextualizes Cavell's New Zealand memorialization.
Seafarer's gaze: Queen Street business and Auckland's archipelago, 1908
Authors: Winder Gordon M.
Published: March 2006

Abstract:  In 1908 Auckland City was the commercial hub for a small and remote provincial economy and cannot have supported more than modest, locally orientated enterprises. This paper argues that such a view is conditioned by a ‘landlubber's gaze’. By envisaging a seafarer alighting on the City's wharves from a 1908 steamship to encounter the city's commercial heart, it demonstrates that Queen Street opened to a maritime world where Auckland enterprises enjoyed extensive networks and markets. Indeed, Auckland's ‘floating world’ rivalled its ‘residential world’. Such an approach may force us to recast Auckland Province in archipelago and network terms.
Grassland utopia and Silent Spring: Rereading the agrichemical revolution in New Zealand
Authors: Wildblood‐Crawford Bruce
Published: March 2006

Abstract:  This paper explores the post‐World War II ‘green revolution’ in agricultural chemicals and its representation in Service, a New Zealand chemical industry journal. In particular, I describe how various ‘texts’ within the journal constructed the revolution largely in utopian terms. Critically rereading these texts reveals the extent to which chemical use in agriculture was tied to post‐war discourses of unwavering optimism about science, technology and progress.
Resource management and Māori attitudes to water in southern New Zealand
Authors: Williams Jim
Published: March 2006

Abstract:  Pre‐contact Māori regarded land and water as a single entity, with a common regime of resource management practices. Underpinning these was a world‐view that involved unique spiritual concepts, the most important of which was mauri: the notion that a body of water had its own life‐force. Waters were classified according to the state of their mauri. The paper outlines traditional approaches and how they are applied today.
Historical Auckland on foot
Authors: Winder Gordon M. , Henry Matthew
Published: March 2006

Abstract:  This paper discusses three walking tour guides prepared for the 12th International Conference of Historical Geographers. It argues that the guides are innovative in terms of format, content and ironic sensibility. It construes them as devices for re‐imagining Auckland's urban heritage.
Expected Annual Emergency Miles per Ambulance: An Indicator for Measuring Availability of Emergency Medical Services Resources
Authors: Patterson P.Daniel , Probst Janice C. , Moore Charity G.
Published: March 2006

ABSTRACT: 
Context: To ensure equitable access to prehospital care, as recommended by the Rural and Frontier Emergency Medical Services (EMS) Agenda for the Future, policymakers will need a uniform measure of EMS infrastructure. Purpose and Methods: This paper proposes a county‐level indicator of EMS resource availability that takes into consideration existing EMS resources (ambulances), population health and demographics, and geographic factors. The indicator, the EXpected annual emergency miles per AMBulance (EXAMB), provides a basis for comparing ambulance availability across counties within states. A method for calculating the EXAMB indicator is demonstrated using data from 5 states. Findings: The EXAMB indicator was negatively correlated with ambulance availability per 100,000 population in 4 of the 5 states in the study. The indicator was positively correlated with rurality in 3 states. In Mississippi, South Carolina, and Wyoming, whole‐county health professional shortage areas had median EXAMB values 45%–81% higher than those of the non–health professional shortage areas counties. Conclusions: Future research should explore the relationship of the EXAMB to EMS outcomes, with the ultimate goal of developing a nationally recognized indicator of “adequate” EMS resource availability.
Prevalence and Trends in Smoking: A National Rural Study
Authors: Doescher Mark P. , Jackson J. Elizabeth , Jerant Anthony , Gary Hart L.
Published: March 2006

ABSTRACT: 
Context: Cigarette smoking is the leading preventable cause of death in the United States. Purpose: To estimate the prevalence of and recent trends in smoking among adults by type of rural location and by state. Methods: Random‐digit telephone survey of adults aged 18 years or older who participated in the Behavioral Risk Factor Surveillance System in 1994‐1996 (n = 342,055) and 2000‐2001 (n = 385,384). The main outcome measure was current cigarette smoking, defined as persons who smoke every day or some days, while nonsmokers were those who smoke not at all or reported never having smoked as many as 100 cigarettes. Findings: The prevalence of smoking changed little from the mid‐1990s; in 2000‐2001, it was 22.0% in urban areas, 24.9% in rural adjacent areas, 24.0% in large rural nonadjacent areas, and 24.9% in small rural nonadjacent areas. For rural locations combined, smoking prevalence was not below the 12% goal of Healthy People 2010 for any state, although the 12.5% prevalence in rural Utah approached this target. Prevalence was ≥28% for rural residents of Kentucky, Ohio, and Indiana. Since the mid‐1990s, the prevalence of smoking for rural respondents decreased by more than 2 percentage points in 6 states: California, Connecticut, Maryland, North Carolina, Tennessee, and Utah. However, it increased by 2 percentage points or more in 10 states: Alabama, Delaware, Georgia, Massachusetts, Michigan, Mississippi, New Hampshire, Oklahoma, South Carolina, and Texas. Conclusions: Smoking remains a refractory public health problem. Better ways to curb smoking in rural America are needed.
Antitobacco Media Awareness of Rural Youth Compared to Suburban and Urban Youth in Indiana
Authors: Zollinger Terrell W. , Saywell Robert M. , Overgaard Amanda D. , Przybylski Michael J. , Dutta‐Bergman Mohan
Published: March 2006

ABSTRACT: 
Purpose: This study examined the awareness and impact of antitobacco media messages among rural, suburban, and urban youth. Method: Self‐administered questionnaires were received from 1,622, 1,059, and 1,177 middle school (sixth, seventh, and eighth grade) students in rural, suburban, and urban locations, respectively. Logistic regression compared media awareness and impact among the groups, controlling for grade, gender, race, and smoking behavior. Results: Compared to rural youth, suburban youth were more likely to recall media messages about the dangerous health effects of tobacco use (odds ratio [OR] = 1.94) and have their personal choice to use tobacco affected by the messages (OR = 1.85). Suburban and urban youth more often recalled antitobacco messages (OR = 2.00 and 2.15), reported that the messages made them think about the dangers of tobacco use (OR = 2.02 and 1.47), believed that these ads prevent youth from initiating tobacco use (OR = 3.21 and 1.46) and stop youth from using tobacco (OR = 2.25 and 1.47), and recalled seeing specific campaign television ads (OR = 3.72 and 3.57). Urban youth were more likely to recall specific campaign messages on the radio (OR = 1.58). Neither suburban nor urban youth differed from the rural youth on whether the campaign‐specific radio and television ads made them think about not using tobacco. Conclusions: The results support the need for targeting antitobacco media announcements to youth, based on their residence.
Rural‐Urban Differences in Colon Cancer Risk in Blacks and Whites: The North Carolina Colon Cancer Study
Authors: Kinney Anita Yeomans , Harrell Janna , Slattery Marty , Martin Christopher , Sandler Robert S.
Published: March 2006

ABSTRACT: Context:Geographic and racial variations in cancer incidence have been observed. Studies of colorectal carcinoma indicate a higher incidence and mortality rate for blacks than for whites in the United States.Purpose:We evaluated the effect of rural versus urban residence on colon cancer risk and stage of disease at diagnosis in blacks and whites.Methods:Interviews were conducted with 558 colon cancer cases and 952 controls enrolled in the North Carolina Colon Cancer Study, a population‐based case‐control study of blacks and whites residing in 33 contiguous counties.Findings:Residence in a rural area was associated with increased colon cancer risk (odds ratio, 1.4; 95% confidence interval, 1.1‐1.8). This association was no longer significant after controlling for recent use of colorectal cancer screening tests (odds ratio, 1.2; 95% confidence interval, 0.9‐1.6). Risk estimates were not modified by race nor were they markedly different for extent of disease at diagnosis. However, colorectal cancer screening rates were lower for blacks than for whites.Conclusion:Our findings suggest that rural blacks and whites are at increased risk of colon cancer regardless of stage of disease at diagnosis than their urban counterparts; this relationship may be mediated by screening behavior.
Technology, Job Satisfaction, and Retention: Rural Mental Health Practitioners
Authors: Meyer Deborah
Published: March 2006

ABSTRACT: 
Context: Job satisfaction as it relates to retention of mental health professionals is a major problem in rural areas. Several authors have suggested that technology can positively influence job satisfaction and thus improve retention. Objectives: This study examined technology use and technology expertise in relationship to job satisfaction. It is based on a theoretical framework that asserts as technology use increases, communication among providers and access to educational and consultative resources increase as well, resulting in a boost in professional support and a reduction in isolation. Methods: Surveys were sent to 320 providers in rural southeast Ohio; 163 returned usable surveys. Findings: There was a statistically significant relationship between the combination of technology use and expertise and job satisfaction. Use alone, however, was not significant. Despite the fact that over 90% of respondents had access to both a computer and the Internet, just 45% used technology to communicate with peers and nearly 96% indicated that they never or rarely used the Internet for educational programs. Conclusions: The results challenge the assertion that technology plays a major role in job satisfaction and rural retention since access and perceived expertise did not guarantee technology usage. Decisions to stay or leave a rural practice involve a complex array of factors. Technology, with its ability to link providers to resources outside the geographic bounds of an individual's practice, may play a role, but since its adoption can be costly in both time and money, future studies need to determine its place in the retention model.
Physical Activity Among Rural Older Adults With Diabetes
Authors: Arcury Thomas A. , Snively Beverly M. , Bell Ronny A. , Smith Shannon L. , Stafford Jeanette M. , Wetmore‐Arkader Lindsay K. , Quandt Sara A.
Published: March 2006

ABSTRACT: 
Purpose: This analysis describes physical activity levels and factors associated with physical activity in an ethnically diverse (African American, Native American, white) sample of rural older adults with diabetes. Method: Data were collected using a population‐based, cross‐sectional stratified random sample survey of 701 community‐dwelling elders with diabetes completed in 2 rural North Carolina counties. Outcome measures were as follows: first, physical activity in the past year, and second, days physically active in the prior week (0‐7). Potential correlates included personal and health characteristics and were evaluated for statistical significance using logistic regression models. Findings: About half (52.5%) of the participants stated that they had engaged in physical activity in the past year. Among those, 42.5% stated that they had no days with at least 30 minutes of continuous physical activity in the prior week, while 21.5% reported daily physical activity. Common activities were walking and housework. Correlates of physical activity in the past year and days active in the prior week included measures of physical health and mobility. Conclusions: Physical activity in this ethnically diverse sample of rural elders with diabetes is limited. Effort must be invested to increase physical activity in these groups.
Family Perspectives on Pathways to Mental Health Care for Children and Youth in Rural Communities
Authors: Boydell Katherine M. , Pong Raymond , Volpe Tiziana , Tilleczek Kate , Wilson Elizabeth , Lemieux Sandy
Published: March 2006

ABSTRACT: 
Context: There is insufficient literature documenting the mental health experiences and needs of rural communities, and a lack of focus on children in particular. This is of concern given that up to 20% of children and youth suffer from a diagnosable mental health problem. Purpose: This study examines issues of access to mental health care for children and youth in rural communities from the family perspective. Methods: In‐depth interviews were conducted in rural Ontario, Canada, with 30 parents of children aged 3‐17 who had been diagnosed with emotional and behavioral disorders. Findings: Interview data indicate 3 overall thematic areas that describe the main barriers and facilitators to care. These include personal, systemic, and environmental factors. Family members are constantly negotiating ongoing tension, struggle, and contradiction vis‐à‐vis their attempts to access and provide mental health care. Most factors identified as barriers are also, under different circumstances, facilitators. Analysis clustered around the contrasts, contradictions, and paradoxes present throughout the interviews. Conclusions: The route to mental health care for children in rural communities is complex, dynamic, and nonlinear, with multiple roadblocks. Although faced with multiple roadblocks, there are also several factors that help minimize these barriers.
Na+ and pH dependence of proline and β‐alanine absorption in rat small intestine
Authors: Iñigo C. , Barber A. , Lostao M. P.
Published: March 2006

Aims:  Early characterization of intestinal absorption of imino acids in mammals has demonstrated the existence of a Na+‐dependent, Cl−‐independent transport system in rat small intestine, which is the only carrier for β‐alanine. Based on the substrate selectivity, it was proposed that the Proton Amino Acid Transporter 1 (PAT1) could be the same as this imino acid carrier. The present study characterizes the pH and Na+ dependence of proline and β‐alanine uptake in rat small intestine.

Methods:  Intestinal uptake of radiolabelled l‐proline or β‐alanine was measured in brush border membrane vesicles and everted intestinal rings, in the presence and absence of Na+ and at different pH values.

Results:  The existence of an inwardly directed H+ gradient in the absence of Na+ enhanced the initial entry of proline and β‐alanine in brush border membrane vesicles, that reached a transient overshoot with maximal value around 30 s. In the absence of pH gradient, no overshoot was shown. In entire tissue, there was an increase of proline and β‐alanine uptake at acidic pH that was higher in the presence of Na+ than in its absence. This ion dependence and pH effect of the amino acids uptake also increased with the incubation period. Substrate inhibition studies confirmed that intestinal proline absorption in rat occurs mainly by system B and PAT1‐like transporter.

Conclusions:  There is a Na+‐independent, H+‐dependent transporter of amino acids at the apical membrane of the rat enterocytes.
Shoot herbivory on the invasive plant, Centaurea maculosa, does not reduce its competitive effects on conspecifics and natives
Authors: A. Newingham Beth , M. Callaway Ragan
Published: March 2006

Herbivory can have negative, positive, or no effect on plants. However, insect biological control assumes that herbivory will negatively affect the weed and release natives from competition. Centaurea maculosa, an invader in North America, is tolerant to herbivory, and under some conditions, herbivory may increase its competitive effects on natives. Therefore, we investigated two hypotheses: 1) herbivory stimulates compensatory growth by C. maculosa, which increases its competitive effects, and 2) herbivory stimulates the allelopathic effect of C. maculosa. In the greenhouse, Trichoplusia ni shoot herbivory reduced C. maculosa biomass when shoot damage exceeded 40% of the total original leaf area. Conspecific neighbors had no effect on C. maculosa biomass, and the presence of the natives Festuca idahoensis and F. scabrella had a positive effect on C. maculosa. Neighbors did not alter the effects of shoot herbivory. More importantly, even intense shoot herbivory on C. maculosa did not benefit neighboring plants. In a field experiment, clipping 50% of C. maculosa aboveground biomass in the early summer and again in the late summer reduced final biomass by 40% at the end of the season; however, this clipping did not affect total biomass production or reproductive output. Festuca idahoensis neighbors did not increase the effects of clipping, and aboveground damage to C. maculosa did not release F. idahoensis from competition. In the greenhouse we used activated carbon to adsorb allelochemicals, which reduced the competitive effects of C. maculosa on F. idahoensis but not on F. scabrella or other C. maculosa. However, we found no increase in the allelopathic effects of C. maculosa after shoot herbivory. In summary, our results correspond with others indicating that exceptionally high intensities of herbivory are required to suppress C. maculosa growth and reproduction; however, even intense herbivory on C. maculosa does not insure that native bunchgrasses will benefit.
Decreased reproductive investment of female threespine stickleback Gasterosteus aculeatus infected with the cestode Schistocephalus solidus: parasite adaptation, host adaptation, or side effect?
Authors: T. Schultz Eric , Topper Michelle , C. Heins David
Published: March 2006

Parasitic infections may cause alterations in host life history, including changes in reproductive investment (absolute amount of energy allocated to reproduction) and reproductive effort (proportion of available energy allocated to reproduction). Such changes in host life history may reflect: 1) a parasite tactic: the parasite adaptively manipulates energy flow within the host so that the host is induced to make a reduction in reproductive effort and reproductive investment, making more energy available to the parasite; 2) no tactic: there is no change in host reproductive effort and reproductive investment simply decreases as a side effect of the parasite depleting host energy stores; 3) a host tactic: the host adaptively increases reproductive effort in the face of infection and loss of body condition, reproductive investment possibly being reduced despite the increased reproductive effort. Females in Alaskan lake populations of threespine sticklebacks (Gasterosteus aculeatus) are capable of clutch production when parasitized by the cestode Schistocephalus solidus despite large relative parasite masses. We analyzed the somatic energy reserves, maturation stage and ovarian mass of female sticklebacks collected from an Alaska lake during a single reproductive season. We found that parasitized females were less likely to carry fully‐matured gametes, had smaller ovarian masses, and had lower somatic energy stores than unparasitized females. The relationship between reproductive investment and energy storage did not differ between parasitized and unparasitized females. Thus, reproductive effort did not change in response to parasitic infection. We conclude there was no indication of either a parasite tactic or a host tactic. Simple nutrient theft is involved in the parasite's influence on host reproduction, consistent with an earlier hypothesis that reproductive curtailment in threespine sticklebacks is a side effect.
Do autumn leaf colours serve as a reproductive insurance against sucking herbivores?
Authors: Sinkkonen Aki
Published: March 2006

Although autumn leaf colours of deciduous trees have been shown to protect against photo‐oxidative damage, they are sometimes seen as signals to pests and predators. Here I modify the coevolution hypothesis of autumn leaf colours. I suggest that much of the within‐population variation in autumn leaf colours can be explained by differences in the allocation of resources to sexual reproduction. According to the novel hypothesis, reproductively active woody plants produce early and intense autumn leaf colours in order to protect seeds and other reproductive tissues from pests that lay eggs in the autumn. If many seeds mature at times of leaf senescence or during the next summer, a woody plant will reallocate plenty of nitrogen to seeds. If sucking insects reproduce on such hosts, their flightless offspring will suffer poor‐quality food after the ripening of seeds. Before this, however, insects will probably concentrate around the ripening seeds to forage on nitrogen‐rich veins. This will decline the quality and quantity of developing seeds. If, on the other hand, insects are able to recognize reproductively active plants while laying eggs in the autumn, both the insects and the plants benefit. The flightless offspring of insects feeds on plants that supply sufficiently nitrogen for longer than reproducing plants do, while these optimise their reproduction by avoiding pests, which also contributes to the abundance of specialist pests. Hence, I suppose that while physiological factors are the origin of autumnal colour changes of deciduous leaves, the visible cue utilized by insects has evolved several times to an honest signal that reveals the unsuitability of the potential host in the near future. The reproductive insurance hypothesis may help us to understand why bright autumn leaf colours are rare among herbaceous plants, and why plants at high altitudes and latitudes are often brightly coloured in autumn.
P2Y1and P2Y2receptor distribution varies along the human placental vascular tree: role of nucleotides in vascular tone regulation
Authors: Buvinic Sonja , Poblete M. Inés , Donoso M. Verónica , Delpiano Ana María , Briones René , Miranda Ramiro , Huidobro‐Toro J. Pablo
Published: March 2006

The expression of purinergic P2Y receptors (P2YRs) along the cord, superficial chorionic vessels and cotyledons of the human placenta was analysed and functional assays were performed to determine their vasomotor activity. Immunoblots for the P2Y1R and P2Y2R revealed a 6‐ to 8‐fold increase in receptor expression from the cord to the chorionic or cotyledon vessels. In the cord and chorionic vessels the receptor distribution was mainly in the smooth muscle, whereas in the cotyledon vessels these receptors were equally distributed between the endothelium and smooth muscle cells. An exception was the P2Y2R at the umbilical artery, which was distributed as in the cotyledon. mRNA coding for the P2Y1R and P2Y2R were detected by RT‐PCR and the mRNA coding for the P2Y4R, P2Y6R and P2Y11R was also identified. Application of 2‐MeSADP and uridine triphosphate (UTP), preferential P2Y1R and P2Y2R ligands, respectively, resulted in contraction of isolated rings from umbilical and chorionic vessels. The vasoconstriction was blocked in a concentration‐dependent manner by 10–100 nmindomethacin or 10 nmGR32191, suggesting the involvement of thromboxane receptors. MRS 2179, a selective P2Y1R antagonist, reduced the 2‐MeSADP‐ but not the UTP‐evoked contractions. Perfusion of cotyledons with 2‐MeSADP or UTP evoked concentration‐dependent reductions in perfusion pressure mediated by the NO–cGMP pathway. Blockade of NO synthase abolished the vasodilatation and the rise in luminal NO elicited by either agonist. MRS 2179 antagonized the dilatation and rise in luminal NO evoked by 2‐MeSADP but not by UTP. In summary, P2Y1R and P2Y2R are unevenly distributed along the human placental vascular tree; both receptors are coupled to different signalling pathways in the cord/chorionic vesselsversusthe cotyledon leading to opposing vasomotor responses.
Oestrogen and weight loss decrease isoproterenol‐induced Fos immunoreactivity and angiotensin type 1 mRNA in the subfornical organ of female rats
Authors: Krause Eric G. , Curtis Kathleen S. , Stincic Todd L. , Markle Jason P. , Contreras Robert J.
Published: March 2006

Studies from our laboratory and others show that oestrogen reduces angiotensin II (Ang II)‐induced water intake by ovariectomized rats. Elimination of endogenous oestrogen by ovariectomy causes weight gain that can be reversed or prevented by oestrogen replacement. Changes in body weight modify cardiovascular responses to Ang II but whether such changes have similar effects on central and behavioural responses to Ang II is unknown. The goal of this study was to evaluate the contributions of oestrogen and weight loss to isoproterenol (isoprenaline; Iso)‐induced Fos immunoreactivity (IR) and to angiotensin type 1 (AT1) receptor mRNA in forebrain regions implicated in the control of fluid balance. Isoproterenol significantly increased Fos IR in the hypothalamic paraventricular and supraoptic nuclei, the subfornical organ (SFO), and the organum vasculosum of the lamina terminalis, but had no effect on AT1 mRNA expression. However, both Iso‐induced Fos IR and the AT1 mRNA were attenuated in the SFO of the oestrogen and weight loss groups compared with that of the control group. Consequently, we examined the effect of weight loss on Iso‐induced water intake and plasma renin activity (PRA) and found that weight loss decreased water intake after Iso, but had no effect on PRA. Thus, we propose that weight loss decreases Ang II‐elicited water intake in the female rat by down‐regulating the expression of the AT1 receptor.
Novel role of 26RFa, a hypothalamic RFamide orexigenic peptide, as putative regulator of the gonadotropic axis
Authors: Navarro V. M. , Fernández‐Fernández R. , Nogueiras R. , Vigo E. , Tovar S. , Chartrel N. , Le Marec O. , Leprince J. , Aguilar E. , Pinilla L. , Dieguez C. , Vaudry H. , Tena‐Sempere M.
Published: March 2006

The close link between reproductive function and body energy stores relies on a complex neuroendocrine network of common regulatory signals, the nature of which is yet to be fully elucidated. Recently, 26RFa was identified in amphibians and mammals as a conserved hypothalamic neuropeptide of the RFamide family, with a potent orexigenic activity. Yet, despite its proposed role as hypophysiotropic factor, the function of 26RFa in the control of pituitary gonadotropins and, hence, of the reproductive axis remains unexplored. In the present study, the effects of 26RFa on gonadotropin secretion were evaluated in the rat by a combination of in vitro and in vivo approaches. At the pituitary, 26RFa dose‐dependently enhanced basal and gonadotropin‐releasing hormone (GnRH)‐stimulated luteinizing hormone (LH) secretion from male and cyclic female rats. This effect was mimicked by the active fragment 26RFa20–26, as well as by the related 43RFa peptide. Moreover, expression of the genes encoding 26RFa and its putative receptor, GPR103, was demonstrated in rat pituitary throughout postnatal development. In vivo, intracerebral injection of 26RFa evoked a significant increase in serum LH levels in cyclic and ovariectomized females; this response which was also observed after central injection of 26RFa20–26 and 43RFa peptides, as well as after systemic administration of 26RFa. Conversely, central and systemic injection of 26RFa failed to significantly modify gonadotropin secretion in adult male rats, even after repeated administration of the peptide. In summary, we present herein novel evidence for the potential role of the orexigenic peptide 26RFa in the control of the gonadotropic axis, thus suggesting its potential involvement in the joint control of energy balance and reproduction, especially in the female.
On the Spillover of Steady State Unbalance Response of a Rotating Shaft Under Velocity Feedback
Authors: Yang S. M. , Sheu G. J.
Published: March 2006

It has been stated that a uniform rotating shaft in the Rayleigh beam model has only a finite number of critical speeds and precession modes. This paper presents a controller design of optimal sensor/actuator location and feedback gain for steady state unbalance response of a rotating shaft operating in a speed range. For systems under order-limit constraint such that only part of the precession modes can be included in the reduced-order controller design, the system stability can be evaluated. The example of a hinged-hinged rotating shaft is employed to illustrate the controller design of velocity feedback in collocated and noncollocated senor/actuator configuration. Analyses show that the reduced-order controller not only guarantees the closed loop system stability but also effectively suppress the unbalance response.
Characterization of Intermittent Contact in Tapping-Mode Atomic Force Microscopy
Authors: Zhao Xiaopeng , Dankowicz Harry
Published: March 2006

Tapping-mode atomic force microscopy has wide applications for probing the nanoscale surface and subsurface properties of a variety of materials in a variety of environments. Strongly nonlinear effects due to large variations in the force field on the probe tip over very small length scales and the intermittency of contact with the sample, however, result in strong dynamical instabilities. These can result in a sudden loss of stability of low-contact-velocity oscillations of the atomic-force-microscope tip in favor of oscillations with high contact velocity, coexistence of stable oscillatory motions, and destructive, nonrepeatable, and unreliable characterization of the nanostructure. In this paper, dynamical systems tools for piecewise-smooth systems are employed to characterize the loss of stability and associated parameter-hysteresis phenomena.
Probing Gene Expression in Live Cells, One Protein Molecule at a Time
Authors: Yu Ji , Xiao Jie , Ren Xiaojia , Lao Kaiqin , Xie X. Sunney
Published: March 2006

We directly observed real-time production of single protein molecules in individual
Escherichia coli
cells. A fusion protein of a fast-maturing yellow fluorescent protein (YFP) and a membrane-targeting peptide was expressed under a repressed condition. The membrane-localized YFP can be detected with single-molecule sensitivity. We found that the protein molecules are produced in bursts, with each burst originating from a stochastically transcribed single messenger RNA molecule, and that protein copy numbers in the bursts follow a geometric distribution. The quantitative study of low-level gene expression demonstrates the potential of single-molecule experiments in elucidating the workings of fundamental biological processes in living cells.
Visualizing Picometric Quantum Ripples of Ultrafast Wave-Packet Interference
Authors: Katsuki Hiroyuki , Chiba Hisashi , Girard Bertrand , Meier Christoph , Ohmori Kenji
Published: March 2006

Interference fringes in vibrating molecules are a signature of quantum mechanics, but are often so short-lived and closely spaced that they elude visualization. We have experimentally visualized dynamical quantum interferences, which appear and disappear in less than 100 femtoseconds in the iodine molecule synchronously with the periodic crossing of two counterpropagating nuclear wave packets. The obtained images have picometer and femtosecond spatiotemporal resolution, representing a detailed picture of the quantum interference.
Response to Comment on "Ivory-billed Woodpecker (
Campephilus principalis
) Persists in Continental North America"
Authors: Fitzpatrick John W. , Lammertink Martjan , Luneau M. David , Gallagher Tim W. , Rosenberg Kenneth V.
Published: March 2006

Claims that the bird in the Luneau video is a normal pileated woodpecker are based on misrepresentations of a pileated's underwing pattern, interpretation of video artifacts as plumage pattern, and inaccurate models of takeoff and flight behavior. These claims are contradicted by experimental data and fail to explain evidence in the Luneau video of white dorsal plumage, distinctive flight behavior, and a perched woodpecker with white upper parts.
State-Dependent Learned Valuation Drives Choice in an Invertebrate
Authors: Pompilio Lorena , Kacelnik Alex , Behmer Spencer T.
Published: March 2006

Humans and other vertebrates occasionally show a preference for items remembered to be costly or experienced when the subject was in a poor condition (this is known as a sunk-costs fallacy or state-dependent valuation). Whether these mechanisms shared across vertebrates are the result of convergence toward an adaptive solution or evolutionary relicts reflecting common ancestral traits is unknown. Here we show that state-dependent valuation also occurs in an invertebrate, the desert locust
Schistocerca gregaria
(Orthoptera: Acrididae). Given the latter's phylogenetic and neurobiological distance from those groups in which the phenomenon was already known, we suggest that state-dependent valuation mechanisms are probably ecologically rational solutions to widespread problems of choice.
Dr. Strangelove Moves Mountains
Authors: Gusterson Hugh
Published: March 2006

Proving Grounds
. Project Plowshare and the Unrealized Dream of Nuclear Earthmoving.
By Scott Kirsch
. Rutgers University Press, New Brunswick, NJ, 2005. 272 pp. $39.95. ISBN 0-8135-3666-9.

The author explores the two-decades-long efforts of Edward Teller and others to promote the use of nuclear explosions to construct canals, dams, harbors, and quarries.
Genetic Diversity of the Q Fever Agent,Coxiella burnetii, Assessed by Microarray-Based Whole-Genome Comparisons
Authors: Beare Paul A. , Samuel James E. , Howe Dale , Virtaneva Kimmo , Porcella Stephen F. , Heinzen Robert A.
Published: March 2006

Coxiella burnetii, a gram-negative obligate intracellular bacterium, causes human Q fever and is considered a potential agent of bioterrorism. Distinct genomic groups ofC. burnetiiare revealed by restriction fragment-length polymorphisms (RFLP). Here we comprehensively define the genetic diversity ofC. burnetiiby hybridizing the genomes of 20 RFLP-grouped and four ungrouped isolates from disparate sources to a high-density custom Affymetrix GeneChip containing all open reading frames (ORFs) of the Nine Mile phase I (NMI) reference isolate. We confirmed the relatedness of RFLP-grouped isolates and showed that two ungrouped isolates represent distinct genomic groups. Isolates contained up to 20 genomic polymorphisms consisting of 1 to 18 ORFs each. These were mostly complete ORF deletions, although partial deletions, point mutations, and insertions were also identified. A total of 139 chromosomal and plasmid ORFs were polymorphic among allC. burnetiiisolates, representing ca. 7% of the NMI coding capacity. Approximately 67% of all deleted ORFs were hypothetical, while 9% were annotated in NMI as nonfunctional (e.g., frameshifted). The remaining deleted ORFs were associated with diverse cellular functions. The only deletions associated with isogenic NMI variants of attenuated virulence were previously described large deletions containing genes involved in lipopolysaccharide (LPS) biosynthesis, suggesting that these polymorphisms alone are responsible for the lower virulence of these variants. Interestingly, a variant of the Australia QD isolate producing truncated LPS had no detectable deletions, indicating LPS truncation can occur via small genetic changes. Our results provide new insight into the genetic diversity and virulence potential ofCoxiellaspecies.
Cross-Linked Peptidoglycan Mediates Lysostaphin Binding to the Cell Wall Envelope ofStaphylococcus aureus
Authors: Gründling Angelika , Schneewind Olaf
Published: March 2006

Staphylococcus simulansbv. staphylolyticus secretes lysostaphin, a bacteriocin that cleaves pentaglycine cross bridges in the cell wall ofStaphylococcus aureus. The C-terminal cell wall-targeting domain (CWT) of lysostaphin is required for selective binding of this bacteriocin toS. aureuscells; however, the molecular target for this was unknown. We used purified green fluorescent protein fused to CWT (GFP-CWT) to reveal species-specific association of the reporter with staphylococci. GFP-CWT boundS. aureuscells as well as purified peptidoglycan sacculi. The addition of cross-linked murein, disaccharides linked to interconnected wall peptides, blocked GFP-CWT binding to staphylococci, whereas murein monomers or lysostaphin-solubilized cell wall fragments did not.S. aureusstrain Newman variants lacking the capacity for synthesizing polysaccharide capsule (capFO), poly-N-acetylglucosamine (icaAC), lipoprotein (lgt), cell wall-anchored proteins (srtA), or the glycolipid anchor of lipoteichoic acid (ypfP) bound GFP-CWT similar to wild-type staphylococci. AtagOmutant strain, defective in the synthesis of polyribitol wall teichoic acid attached to the cell wall envelope, displayed increased GFP-CWT binding. In contrast, afemABmutation, reducing both the amount and the length of peptidoglycan cross-linking (monoglycine cross bridges), showed a dramatic reduction in GFP-CWT binding. Thus, the CWT domain of lysostaphin directs the bacteriocin to cross-linked peptidoglycan, which also serves as the substrate for its glycyl-glycine endopeptidase domain.