bluuebunny/crossref_metadata_2025 huggingface dataset:
Social Investment Policies in Chile and Latin America: Towards Equal Opportunities for Women and Children?
Authors: STAAB SILKE
Published: April 2010

Social investment ideas are increasingly permeating social and care policy-making in Latin America. In this article, I analyse a variety of instruments which have been used to ‘invest in children’ across a range of Latin American countries to then zoom in on Chile, where early childhood education and care have attained a prominent place on the welfare agenda in recent years. This policy interest materialised in ‘Chile Grows With You’, an integrated child development strategy whose title resonates strongly with the global narrative on social investment. Engaging with the programme's aim of creating ‘equal opportunities from the cradle’, I discuss the transformative potential and the limitations of childcare service expansion in a highly unequal context.
Does the public think it is reasonable to wait for more evidence before funding innovative health technologies? The case of PET scanning in Ontario
Authors: Chafe Roger , Merali Farhan , Laupacis Andreas , Levinson Wendy , Martin Doug
Published: April 2010

Objectives:Many innovative health technologies do not have a sufficient evidence-base to allow for adequate assessment of their benefits. Funders in several countries have been exploring arrangements that allow for temporary or partial coverage of these technologies, but only as part of a further evaluation. The public's support of arrangements that restrict access to innovative technology until sufficient evidence is available is crucial if these arrangements are going to remain viable. The project's other objective is to examine the lay public's views on a case in which patients’ publicly funded access to an innovative health technology is being delayed until there is sufficient evidence to justify a coverage decision. The case considered is the Ontario (Canada) government's decision to restrict access to positron emission tomography (PET) scans until further evidence becomes available.

Methods:The case was deliberated on by twenty-six members of theToronto Health Policy Citizens' Council, with a follow-up survey administered to individual council members.

Results:The majority of council members agreed that the approach taken by the government was reasonable and in the best interests of its citizens. The council did express concerns regarding certain aspects of the case, including about the length of time it is taking to obtain further evidence.

Conclusions:Public support for arrangements that limit access to new technologies will likely vary depending on the details of the specific arrangement being proposed. Deliberative public dialogue can be effectively used to identify cases the general public is most likely to support.
Keys to a successful and sustainable telemedicine program
Authors: Whitten Pamela , Holtz Bree , Nguyen Lianh
Published: April 2010

Objectives: The aim of this study was to determine organizational characteristics evident in successful telemedicine programs. The study proposed four research questions to identify the key organizational characteristics for successful telemedicine programs.

Methods: Data were collected through an online survey using modified unified theory of acceptance and use of technology (UTAUT) and organizational change readiness (ORC) validated assessments.

Results: Using the UTAUT instrument and the ORC assessment, themes of successful telemedicine programs emerged. Overarching themes of successful programs included being formally structured, forward thinking, seeking to improve the quality of patient care, and being financially stable.

Conclusions: This research provides a data-driven understanding of organizational issues that serve to maximize a telemedicine program's ability to achieve the overall goals and mission of a healthcare organization.
Measuring the influence of colleagues on a consultant team's use of breast conserving surgery
Authors: Hoy Andrew R. , Patrick Hannah , Campbell Bruce , Lyratzopoulos Georgios
Published: April 2010

Objectives: The aim of this study was to examine potential reasons why the use of breast conserving surgery (BCS) for breast cancer varies substantially between hospital teams in England, and in particular to examine whether colleague influence has a role in influencing BCS rates locally.

Methods: Routinely collected Hospital Episode Statistics (HES) data relating to 420 surgical teams in England who performed more than ten breast cancer operations during the financial year 2006/07 were used to identify predictors of team BCS use. Team BCS rates (as a proportion of all types of breast excision surgery) were subject to a regression analysis that incorporated, as independent variables, a range of patient, organizational, and local demographic factors, as well as the BCS rate of colleagues working alongside them in the same hospitals(s).

Results: After adjusting for the effects of other variables, BCS use by colleagues working in the same hospital(s) was a significant predictor of a team's own BCS rate (standardized b = 0.224; p < .001), denoting a typical 3 percent increase in a team's BCS rate for every 10 percent increase in the BCS rate of colleagues.

Conclusions: The practice of colleagues seems to have a measurable influence upon a surgical team's BCS usage. Guidance from HTA organizations can set national standards about the use of new techniques and innovations, but dissemination can be either slowed down or accelerated by the influence of local colleagues. A strategy of disseminating guidance through professional networks or “local champions” could be a powerful avenue for change.
Budget impact analysis of trastuzumab in early breast cancer: A hospital district perspective
Authors: Purmonen Timo T. , Auvinen Päivi K. , Martikainen Janne A.
Published: April 2010

Objectives:Adjuvant trastuzumab is widely used in HER2-positive (HER2+) early breast cancer, and despite its cost-effectiveness, it causes substantial costs for health care. The purpose of the study was to develop a tool for estimating the budget impact of new cancer treatments. With this tool, we were able to estimate the budget impact of adjuvant trastuzumab, as well as the probability of staying within a given budget constraint.

Methods:The created model-based evaluation tool was used to explore the budget impact of trastuzumab in early breast cancer in a single Finnish hospital district with 250,000 inhabitants. The used model took into account the number of patients, HER2+ prevalence, length and cost of treatment, and the effectiveness of the therapy. Probabilistic sensitivity analysis and alternative case scenarios were performed to ensure the robustness of the results.

Results:Introduction of adjuvant trastuzumab caused substantial costs for a relatively small hospital district. In base-case analysis the 4-year net budget impact was €1.3 million. The trastuzumab acquisition costs were partially offset by the reduction in costs associated with the treatment of cancer recurrence and metastatic disease.

Conclusions:Budget impact analyses provide important information about the overall economic impact of new treatments, and thus offer complementary information to cost-effectiveness analyses. Inclusion of treatment outcomes and probabilistic sensitivity analysis provides more realistic estimates of the net budget impact. The length of trastuzumab treatment has a strong effect on the budget impact.
Technology on probation
Authors: van der Wilt Gert J.
Published: April 2010

One of the key tasks of governments and their advisory bodies is to decide what the nature and quality of the evidence should be which they use to support their policies. Evidence, as pointed out by Valerie Miké, is inherently incomplete, provisional, and subject to refutation (4). So when are we justified to presume sufficient value of a healthcare technology, warranting its public provision and funding?
Telemedicine in acute stroke management: Systematic review
Authors: Johansson Tim , Wild Claudia
Published: April 2010

Objectives: Stroke is the third largest cause of death and a major factor in permanent disability. Disparities in access to healthcare services exist due to geographical barriers and limited resources. Rural locations often lack the resources for adequate acute stroke care. Telestroke is intended to enable the transfer of knowledge of acute stroke management to areas with limited neurological services. The objective of this study is to assess the feasibility, acceptability, and treatment delivery reliability of telemedicine systems in acute stroke management.

Methods: A systematic review was undertaken.

Results: Eighteen studies were included in this systematic review. Telestroke services have been reported to lead to better functional health outcomes, including reduced mortality and dependency, compared with conventional care. Most studies report that systemic tissue plasminogen activator (tPA) treatment increased in hospitals providing telestroke services, although patients were often transferred to a stroke center for continuing monitoring and surveillance. Patients and healthcare providers reported high levels of satisfaction. There was limited evidence regarding the impact on resource utilization and cost-effectiveness.

Conclusions: Telemedicine systems can be safe, feasible, and acceptable in acute stroke management. Telestroke is associated with increased delivery of tPA. The lack of standardized measuring and reporting of resources and health outcomes hinder comparisons between telestroke networks and the determination of best practices. More research is needed to explore the clinical and economic impact of telemedicine technologies in acute stroke management, so as to support policy makers in making informed decisions.
HTA in the United Kingdom: Response
Authors: Drummond Michael , Banta David
Published: April 2010

Professor Gabbay says he is dismayed that our article on the history of HTA in a recent special issue makes so little mention of the NHS HTA Programme, He calls this “a puzzling oversight,” which “would both surprise and disappoint the thousands . . . who have been involved in some way or another.” It was not our intention to underplay the role of the program, nor to disappoint the thousands of participants. Rather, there was a considerable amount of material to cover and a limited amount of space to do it in. Any history of HTA in the United Kingdom is inevitably a personal reflection, and it is understandable that Professor Gabbay's own account would put the program more center-stage, given his role as former director.
Policy brief on improving access to artemisinin-based combination therapies for malaria in the East African community
Authors: Nabudere Harriet , Upunda Gabriel L. , Juma Malick
Published: April 2010

The World Health Organization (WHO) since June 1998 has advocated for the use of artemisinin-based combination therapies (ACTs) in countries where Plasmodium falciparum malaria is resistant to traditional antimalarial therapies such as chloroquine, sulfadoxine-pyrimethamine, and amodiaquine (19;22). In 2006, WHO released evidence-based guidelines for the treatment of malaria backed by findings from various scientific studies (21). During the period between 2002 and 2006, all the five East African states Tanzania, Kenya, Uganda, Rwanda, and Burundi changed their national antimalarial treatment policies to use ACTs as first-line treatments for uncomplicated falciparum malaria and commenced with deployment of the drugs in the state-managed health facilities (12–15). To scale up the use of ACTs in the East African region to combat malaria and speed up progress toward the sixth Millennium Development Goal, a combination of delivery, financial, and governance arrangements tailored to national or subnational contexts needs to be considered.
EVIPNet Africa's first series of policy briefs to support evidence-informed policymaking
Authors: Lavis John N. , Panisset Ulysses
Published: April 2010

EVIPNet (Evidence-Informed Policy Network) Africa—a network of World Health Organization (WHO)-sponsored knowledge-translation (KT) platforms in seven sub-Saharan African countries—was launched at a meeting in Brazzaville, Congo, in March 2006 (1;2). EVIPNet Africa can trace its origins to resolutions from both the Ministerial Summit on Health Research (November 2004) and the World Health Assembly (May 2005) (10;11), the spirit of which was re-affirmed at the Global Ministerial Forum on Research for Health (November 2008) (13). The World Health Assembly called for “establishing or strengthening mechanisms to transfer knowledge in support of evidence-based public health and health care delivery systems and evidence-based related policies” (10). EVIPNet Africa can trace its inspiration to a more local development: the preparatory work that led to the establishment of the East African Community–sponsored Regional East African Community Health (REACH) Policy initiative, a KT platform involving Kenya, Tanzania, and Uganda (and more recently Burundi and Rwanda as well). REACH Policy is now part of the EVIPNet Africa family.
Risk factors for multidrug-resistant Escherichia coli rectal colonization of dogs on admission to a veterinary hospital
Authors: GIBSON J. S. , MORTON J. M. , COBBOLD R. N. , FILIPPICH L. J. , TROTT D. J.
Published: April 2010

This study aimed to identify risk factors for intestinal colonization with multidrug-resistant (MDR) E. coli in dogs on admission to a veterinary teaching hospital. Exposures to potential risk factors, including prior treatments, hospitalizations and interventions during the 42 days prior to admission were assessed for 82 case admissions and 82 time-matched controls in a retrospective prevalence-based case-control study of 20 months duration. On multivariable analyses, risk of MDR E. coli colonization on admission was increased with prior hospitalization for 4–7 days and >7 days relative to shorter periods, and in dogs that had prior diagnostic imaging techniques. Univariable analyses indicated that risk was increased following prior treatment with several antimicrobial agents. However, on multivariable analysis, administration of fluoroquinolones was associated with increased risk but risk did not appear to increase following administration of other antimicrobials. These results can inform management of canine patients and infection control procedures to mitigate the risk of clinical disease due to MDR bacteria in hospitalized dogs.
Development of excitatory and inhibitory neurotransmitters in transitory cholinergic neurons, starburst amacrine cells, and GABAergic amacrine cells of rabbit retina, with implications for previsual and visual development of retinal ganglion cells
Authors: FAMIGLIETTI EDWARD V. , SUNDQUIST SARAH J.
Published: April 2010

Starburst amacrine cells (SACs), the only acetylcholine (ACh)-releasing amacrine cells (ACs) in adult rabbit retina, contain GABA and are key elements in the retina’s directionally selective (DS) mechanism. Unlike many other GABAergic ACs, they use glutamic acid decarboxlyase (GAD)67, not GAD65, to synthesize GABA. Using immunocytochemistry, we demonstrate the apoptosis at birth (P0) of transitory putative ACs that exhibit immunoreactivity (IR) for the ACh-synthetic enzyme choline acetyltransferase (ChAT), GAD67, and the GABA transporter, GAT1. Only a few intact, displaced ChAT-immunoreactive SAC bodies are detected at P0. At P2, ChAT-IR is detected in the two narrowly stratified substrata of starburst dendrites in the inner plexiform layer (IPL). Quantitative analysis reveals that in the first postnatal week, only a small fraction of SACs cells express ChAT- and GABA-IR. Not until the end of the second week are they expressed in all SACs. At P0, a three-tiered stratification of GABA-IR is present in the IPL, entirely different from the adult pattern of seven substrata, emerging at P3–P4, and optimally visualized at P13. At P0, GAD65 is detectable in normally placed AC bodies. At P1, GAD65-IR appears in dendrites of nonstarburst GABAergic ACs, and by P5 is robust in the adult pattern of four substrata in the IPL. GAD65-IR never co-localizes with ChAT-IR. In a temporal comparison of our data with physiological, pharmacological, and ultrastructural studies, we suggest that transitory ChAT-immunoreactive cells share with SACs production of stage II (nicotinic) waves of previsual synchronous activity in ganglion cells (GCs). Further, we conclude that (1) GAD65-immunoreactive, non-SAC GABAergic ACs are the most likely candidates responsible for the suppression of stage III (muscarinic/AMPA-kainate) waves and (2) DS responses first appear in DS GCs, when about 50% of SACs express ChAT- and GABA-IR, and in 100% of DS GCs, when expression occurs in all SACs.
The response dynamics of rabbit retinal ganglion cells to simulated blur
Authors: RISNER MICHAEL L. , AMTHOR FRANKLIN R. , GAWNE TIMOTHY J.
Published: April 2010

Retinal ganglion cells (RGCs) are highly sensitive to changes in contrast, which is crucial for the detection of edges in a visual scene. However, in the natural environment, edges do not just vary in contrast, but edges also vary in the degree of blur, which can be caused by distance from the plane of fixation, motion, and shadows. Hence, blur is as much a characteristic of an edge as luminance contrast, yet its effects on the responses of RGCs are largely unexplored.

We examined the responses of rabbit RGCs to sharp edges varying by contrast and also to high-contrast edges varying by blur. The width of the blur profile ranged from 0.73 to 13.05 deg of visual angle. For most RGCs, blurring a high-contrast edge produced the same pattern of reduction of response strength and increase in latency as decreasing the contrast of a sharp edge. In support of this, we found a significant correlation between the amount of blur required to reduce the response by 50% and the size of the receptive fields, suggesting that blur may operate by reducing the range of luminance values within the receptive field. These RGCs cannot individually encode for blur, and blur could only be estimated by comparing the responses of populations of neurons with different receptive field sizes. However, some RGCs showed a different pattern of changes in latency and magnitude with changes in contrast and blur; these neurons could encode blur directly.

We also tested whether the response of a RGC to a blurred edge was linear, that is, whether the response of a neuron to a sharp edge was equal to the response to a blurred edge plus the response to the missing spatial components that were the difference between a sharp and blurred edge. Brisk-sustained cells were more linear; however, brisk-transient cells exhibited both linear and nonlinear behavior.
Six different roles for crossover inhibition in the retina: Correcting the nonlinearities of synaptic transmission
Authors: WERBLIN FRANK S.
Published: April 2010

Early retinal studies categorized ganglion cell behavior as either linear or nonlinear and rectifying as represented by the familiar X- and Y-type ganglion cells in cat. Nonlinear behavior is in large part a consequence of the rectifying nonlinearities inherent in synaptic transmission. These nonlinear signals underlie many special functions in retinal processing, including motion detection, motion in motion, and local edge detection. But linear behavior is also required for some visual processing tasks. For these tasks, the inherently nonlinear signals are “linearized” by “crossover inhibition.” Linearization utilizes a circuitry whereby nonlinear ON inhibition adds with nonlinear OFF excitation or ON excitation adds with OFF inhibition to generate a more linear postsynaptic voltage response. Crossover inhibition has now been measured in most bipolar, amacrine, and ganglion cells. Functionally crossover inhibition enhances edge detection, allows ganglion cells to recognize luminance-neutral patterns with their receptive fields, permits ganglion cells to distinguish contrast from luminance, and maintains a more constant conductance during the light response. In some cases, crossover extends the operating range of cone-driven OFF ganglion cells into the scotopic levels. Crossover inhibition is also found in neurons of the lateral geniculate nucleus and V1.
Effect of polyphenols on the intestinal and placental transport of some bioactive compounds
Authors: Martel Fátima , Monteiro Rosário , Calhau Conceição
Published: April 2010

Polyphenols are a group of widely distributed phytochemicals present in most foods of vegetable origin. A growing number of biological effects have been attributed to these molecules in the past few years and only recently has their interference with the transport capacity of epithelial barriers received attention. This review will present data obtained concerning the effect of polyphenols upon the transport of some compounds (organic cations, glucose and the vitamins thiamin and folic acid) at the intestinal and placental barriers. Important conclusions can be drawn: (i) different classes of polyphenols affect transport of these bioactive compounds at the intestinal epithelia and the placenta; (ii) different compounds belonging to the same phenolic family often possess opposite effects upon transport of a given molecule; (iii) the acute and chronic/short-term and long-term exposures to polyphenols do not produce parallel results and, therefore, care should be taken when extrapolating results; (iv) the effect of polyphenolics in combination may be very different from the expected ones taking into account the effect of each of these compounds alone, and so care should be taken when speculating on the effect of a drink based on the effect of one component only; (v) care should be taken in drawing conclusions for alcoholic beverages from results obtained with ethanol alone. Although most of the data reviewed in the present paper refer toin vitroexperiments with cell-culture systems, these studies raise a concern about possible changes in the bioavailability of substrates upon concomitant ingestion of polyphenols.
Emerging obesity and dietary habits among James Bay Cree youth
Authors: Khalil Cynthia Bou , Johnson-Down Louise , Egeland Grace M
Published: April 2010

Objective

To describe dietary habits and extent of overweight and obesity among Cree youth.

Design

Dietary intake and habits were assessed by a 24 h recall and FFQ as part of a cross-sectional survey.

Setting

Three Cree communities in northern Québec, Canada.

Subjects

A total of 125 youth aged 9–18 years.

Results

Overall 67·6 % of the study population was either at risk of overweight or overweight. Over 98 % had a usual saturated fat intake over 10 % of energy while 65 % had a lower consumption of fruit/vegetables and 95 % had a lower consumption of milk and milk products than recommended by Canada’s Food Guide. The majority (96·8 %) consumed high-fat foods (>40 % of total energy as fat), which accounted for 39 % of total energy intake (EI). Similarly, 92·8 % consumed high-sugar food and beverages (>25 % of total energy as sugar), which accounted for 12·8 % of total EI. Furthermore, 95 % of the youth had a Healthy Eating Index (HEI) below the recommended score of 80 or above. Certain measures of diet quality (traditional food (TF) consumption, HEI and vegetables and fruit consumption) were significantly correlated with adiposity measures.

Conclusions

A high prevalence of low-diet quality was found with a high degree of sugar and fat intake and a low consumption of vegetables/fruit and milk/milk alternates and any weekly TF. Dietary interventions are sorely needed.
Tracking excess weight and obesity from childhood to young adulthood: a 12-year prospective cohort study in Slovenia
Authors: Starc Gregor , Strel Janko
Published: April 2010

Objective

The objective was to examine the tracking of obesity from childhood to young adulthood in Slovenia.

Subjects

A subsample included 4833 children from the Slovenian national sample (n21 777) who were included in the SLOFIT monitoring system from 1997 to 2008, with complete data at 7 years and 18 years.

Design

A 12-year prospective cohort study. Height, weight and triceps skinfold thickness (TSF) were measured at 7, 11, 14 and 18 years. The BMI cut-off points of the International Obesity Taskforce were used to identify excess weight and obesity.

Setting

The survey was conducted in Slovenian primary and secondary schools from 1988 to 2008 but only the data from the measurements in 1997, 2001, 2004 and 2008 are presented.

Results

Height, weight and BMI at 18 years were well predicted from childhood and became more predictable with age, while TSF was not. Obese and overweight children had the greatest risk of becoming obese or overweight young adults. The history of their weight shows that 40·0 % of males and 48·6 % of females who were obese at 18 years had already been obese at 7 years.

Conclusions

Overweight or obese Slovenian children are more likely to become overweight or obese adolescents and young adults than reported in other similar European and American studies, which indicates the need for early prevention and treatment of excess weight and obesity.
Vitamin D supplementation in young children: associations with Theory of Planned Behaviour variables, descriptive norms, moral norms and habits
Authors: de Nooijer Jascha , Onnink Monique , van Assema Patricia
Published: April 2010

Objective

In the Netherlands, a supplementation of 10 μg vitamin D is recommended for children (aged 0–4 years), given that vitamin D contributes to the development of healthy bones and deficiency during childhood is a risk factor for osteoporosis at a later age. However, only 60 % of the Dutch children receive sufficient vitamin D supplementation a day. In order to develop interventions to improve supplementation intake, it is necessary to gain insight into the behaviour of parents in giving their children vitamin D supplementation and its association with variables of the Theory of Planned Behaviour, moral and descriptive norms and habits.

Design

A cross-sectional survey to assess present supplementation-related behaviour, knowledge, received information, intention, attitude, subjective norm, perceived behavioural control, moral norm, descriptive norm and habit.

Setting

Data obtained from a representative Internet Panel by means of electronic questionnaires.

Subjects

Parents (n 270) of children aged 0–4 years.

Results

Half of the parents (48·9 %) gave their child sufficient vitamin D supplementation. Giving the supplement at a fixed time, a positive intention and habit were significantly associated with actual behaviour. The higher age of the child, first-born status, a fixed time for taking vitamin supplementation, descriptive norm and moral obligation were significantly associated with intention.

Conclusions

These results indicate that because many parents do not give their children adequate vitamin D supplementation, the promotion of supplementation during the first years of life is a necessity. Effective yet simple strategies should be developed, focused on improving moral obligation, descriptive norms and habit formation.
Contamination of basaltic lava by seawater: Evidence found in a lava pillar from Axial Seamount, Juan de Fuca Ridge
Authors: Schiffman Peter , Zierenberg Robert , Chadwick William W. , Clague David A. , Lowenstern Jacob
Published: April 2010

A lava pillar formed during the 1998 eruption at Axial Seamount exhibits compositional and textural evidence for contamination by seawater under magmatic conditions. Glass immediately adjacent to anastomosing microfractures within 1 cm of the inner pillar wall is oxidized and significantly enriched in Na and Cl and depleted in Fe and K with respect to that in glassy selvages from the unaffected outer pillar wall. The affected glass contains up to 1 wt % Cl and is enriched by ∼2 wt % Na2O relative to unaffected glass, consistent with a nearly 1:1 (molar) incorporation of NaCl. Glass bordering the Cl‐enriched glass in the inner pillar wall is depleted in Na but enriched in K. The presence of tiny (<10 μm) grains of Cu‐Fe sulfides and Fe sulfides as well as elemental Ni, Ag, and Au in the Na‐depleted, K‐enriched glass of the inner pillar wall implies significant reduction of this glass, presumably by hydrogen generated during seawater contamination and oxidation of lava adjacent to microfractures. We interpret the compositional anomalies we see in the glass of the interior pillar wall as caused by rapid incorporation of seawater into the still‐molten lava during pillar growth, probably on the time scale of seconds to minutes. Only one of seven examined lava pillars shows this effect, and we interpret that seawater has to be trapped in contact with molten lava (inside the lava pillar, in this case) to produce the effects we see. Thus, under the right conditions, seawater contamination of lavas during submarine eruptions is one means by which the oceanic crust can sequester Cl during its global flux cycle. However, since very few recent lava flows have been examined in similar detail, the global significance of this process in effecting Earth's Cl budget remains uncertain.
Basin‐scale water system operations with uncertain future climate conditions: Methodology and case studies
Authors: Vicuna Sebastian , Dracup John A. , Lund Jay R. , Dale Larry L. , Maurer Edwin P.
Published: April 2010

The old and useful paradigm used by water resource engineers, that hydrology in a given place is stationary, and hence it is sufficient to look into the past to plan for the future, does not hold anymore, according to climate change projections. This becomes especially true in snow‐dominated regions like California, where not only the magnitude but also the timing of streamflow could be affected by changes in precipitation and temperature. To plan and operate water resources systems at the basin scale, it is necessary to develop new tools that are suited for this nonstationary world. In this paper we develop an optimization algorithm that can be used for different studies related to climate change and water resources management. Three applications of this algorithm are developed for the Merced River basin. The first of these gives an assessment of the climate change effects on the operations of this basin considering an adaptive management strategy embedded in the optimization algorithm. In a second application we explore different long‐term adaptation strategies intended to mitigate the effects of climate change. A final application is developed to determine how beneficial it is to build a new reservoir considering explicitly the uncertainty about future climate projections.
Dissimilatory reduction of nitrate in seawater by a Methylophaga strain containing two highly divergent narG sequences
Authors: Auclair Julie , Lépine François , Parent Serge , Villemur Richard
Published: April 2010

Methylophaga spp. are methylotrophs commonly associated with marine environments and have been defined as strict aerobic methylotrophs. They have been shown previously to represent 50–70% of the bacterial population in the biofilm of the methanol-fed denitrification reactor treating a large seawater aquarium at the Montreal Biodome. It was therefore surprising to find such a high concentration of Methylophaga spp. in anoxic conditions. In this study, we showed by cultivation-independent and -dependent approaches that one Methylophaga strain present in the anoxic biofilm is involved in the denitrification process. DNA stable-isotope probing (SIP) experiments in which the biofilm was cultured under denitrifying conditions with 13C-methanol have revealed the enrichment of one particular taxon. By screening a 16S ribosomal RNA gene library derived from a 13C-DNA fraction of the SIP gradients, 62% of the library was composed of one sequence affiliated with the genus Methylophaga. One strain, named JAM1, representing this Methylophaga species was isolated. It grows aerobically but also under denitrifying conditions by reducing nitrate into nitrite. The nitrate-reducing activity was correlated with the presence and the expression of two highly divergent narG genes (narG1 and narG2). narG1 showed a high percentage of identity with the corresponding part of narG found in Thiobacillus denitrificans, which suggests a recent acquisition of narG in strain JAM1 by horizontal gene transfer. This study provides the first direct evidence of the adaptation of a Methylophaga species to an oxygen-limited environment.
A Pilot Randomized Controlled Trial of a Clinic and Home‐Based Behavioral Intervention to Decrease Obesity in Preschoolers
Authors: Stark Lori J. , Spear Stephanie , Boles Richard , Kuhl Elizabeth , Ratcliff Megan , Scharf Cindy , Bolling Christopher , Rausch Joseph
Published: April 2010

We evaluated the efficacy of a 6‐month clinic and home‐based behavioral intervention (Learning about Activity and Understanding Nutrition for Child Health; LAUNCH) to reduce obesity in preschool children ≥95th BMI percentile compared to enhanced standard of care (Pediatrician Counseling; PC). LAUNCH was a family‐based behavioral intervention that taught parents to use child behavior management strategies to increase healthy eating and activity for their children and themselves. PC presented the same diet and activity recommendations, but was delivered in a one‐time PC session. Eighteen children aged 2–5 years (mean 4.71 ± 1.01) with an average BMI percentile of 98 (±1.60) and an overweight parent were randomized to LAUNCH or PC. Assessments were conducted at baseline, 6 months (end of LAUNCH treatment) and 12 months (6 months following LAUNCH treatment). LAUNCH showed a significantly greater decrease on the primary outcomes of child at month 6 (post‐treatment) BMI z (−0.59 ± 0.17), BMI percentile (−2.4 ± 1.0), and weight gain (−2.7 kg ± 1.2) than PC and this difference was maintained at follow‐up (month 12). LAUNCH parents also had a significantly greater weight loss (−5.5 kg ± 0.9) at month 6 and 12 (−8.0 kg ± 3.5) than PC parents. Based on the data from this small sample, an intensive intervention that includes child behavior management strategies to improve healthy eating and activity appears more promising in reducing preschool obesity than a low intensity intervention that is typical of treatment that could be delivered in primary care.
Migration Surrogates and Their Association With Obesity Among Within‐Country Migrants
Authors: Bernabe‐Ortiz Antonio , Gilman Robert H. , Smeeth Liam , Miranda J. Jaime
Published: April 2010

Limited studies have evaluated the link between acculturation and health outcomes of within‐country migrants. The objective of this study was to evaluate whether well‐known acculturation surrogates were associated with obesity among Peruvian rural‐to‐urban migrants. We performed a cross‐sectional survey, the PERU MIGRANT study, using single‐stage random sampling. Evaluation included weight, height, and waist circumference (WC) as well as acculturation surrogates. Obesity was assessed using BMI and WC. Length of residence, age at migration, language proficiency, and language preferences (Spanish or Quechua) were assessed in logistic regression models to calculate odd ratios and 95% confidence intervals adjusting for potential confounders. A total of 589 rural‐to‐urban migrants were enrolled. The mean age was 47.8 (s.d.: 11.7, range: 30–92), and 280 (47.5%) were men. Obesity prevalence assessed using BMI was 30.4% among women and 10.7% among men (P < 0.001), whereas abdominal obesity assessed using WC was 29.1% among women and 19.1% among men (P < 0.01). Obesity was associated with older age at first migration, language speaking proficiency, and language preferences. The association between obesity and acculturation surrogates is variable in this population. Thus, acculturation per se can explore positive channels associated with better health outcomes. The patterns shown in this report suggest a more complex association for these factors.
Relationship between hydrogen content and magnetic properties of diamondlike carbon produced by the rf plasma-enhanced chemical vapor deposition method
Authors: Saito Tetsuji , Terashima Keiichi , Utsushikawa Yoshio
Published: April 2010

Diamondlike carbon (DLC) films were prepared by the rf plasma-enhanced chemical vapor deposition method. The DLC films exhibited ferromagnetic behavior when prepared at 500 W, but diamagnetic behavior when prepared at 900 W. Electron spin resonance studies revealed that the spin density of the ferromagnetic specimen was much higher than that of the diamagnetic specimen. Although no significant difference was found in Raman and x-ray photoelectron spectroscopy studies, a difference in hydrogen content was revealed in elastic recoil detection analysis (ERDA) studies. It was found that the hydrogen content of the ferromagnetic DLC film was 30% higher than that of the diamagnetic film. The origin of the magnetization in the ferromagnetic film is therefore considered to be attributable to the difference in the hydrogen content.
Electron response to collisionless magnetic reconnection
Authors: Perona A. , Eriksson L.-G. , Grasso D.
Published: April 2010

A gyrokinetic test particle code, based on a relativistic Hamiltonian guiding-center formulation, has been developed in order to investigate the behavior of an electron population during a collisionless magnetic reconnection event. The reconstruction of the electron distribution function allows for a detailed comparison between the fluid quantities and the corresponding kinetic moments. Numerical simulations show that, during the linear stage, the growth rates are in agreement, the kinetic density evolves according to the fluid vorticity, and the parallel kinetic temperature remains uniformly distributed in the spatial domain. Only during the nonlinear stage, hotter regions are observed in the magnetic island. The rise in the temperature is associated with a deformation of the electron distribution function, which, however, does not present highly energetic or relativistic tails. This result provides a preliminary indication to which phase of the process the fluid reconnection model assumption of isothermal electrons is valid.
A new optical front-end compensation technique for suppression of spurious signal in photoreflectance spectroscopy using an antiphase signal
Authors: Li Q. , Tan H. H. , Jagadish C.
Published: April 2010

A new optical front-end compensation technique to suppress the unwanted, spurious signal in photoreflectance (PR) spectroscopy is developed. In this approach an optical compensation signal, which is amplitude-matched to and in antiphase to the spurious signal, is introduced and directed to the photodetector. The combination of the compensation signal and the spurious signal results in a dc output from the photodetector which is thereafter suppressed by the lock-in amplifier, leaving only the true PR signal to be recovered and amplified. A high spurious signal suppression efficiency is demonstrated and the advantages of the technique are discussed.
Replica exchange simulation method using temperature and solvent viscosity
Authors: Nguyen Phuong H.
Published: April 2010

We propose an efficient and simple method for fast conformational sampling by introducing the solvent viscosity as a parameter to the conventional temperature replica exchange molecular dynamics (T-REMD) simulation method. The method, named V-REMD (V stands for viscosity), uses both low solvent viscosity and high temperature to enhance sampling for each replica; therefore it requires fewer replicas than the T-REMD method. To reduce the solvent viscosity by a factor of λ in a molecular dynamics simulation, one can simply reduce the mass of solvent molecules by a factor of λ2. This makes the method as simple as the conventional method. Moreover, thermodynamic and conformational properties of structures in replicas are still useful as long as one has sufficiently sampled the Boltzmann ensemble. The advantage of the present method has been demonstrated with the simulations of the trialanine, deca-alanine, and a 16-residue β-hairpin peptides. It shows that the method could reduce the number of replicas by a factor of 1.5 to 2 as compared with the T-REMD method.
Combined effect of the density and velocity gradients in the combination of Kelvin–Helmholtz and Rayleigh–Taylor instabilities
Authors: Wang L. F. , Ye W. H. , Li Y. J.
Published: April 2010

We have derived explicit analytic formulas for the linear growth rate and the frequency in the combination of Kelvin–Helmholtz (KH) and Rayleigh–Taylor (RT) instabilities in fluids with continuous density and velocity profiles. It is found that the density gradient effect (i.e., the density transition layer) decreases the linear growth rate in the RT instability (RTI), especially for the short perturbation wavelength. The linear growth rate for the KH instability (KHI) is increased by the density gradient effect but decreased by the velocity gradient effect (i.e., the velocity transition layer). The frequency in the KHI is reduced by both the density gradient effect and the velocity gradient effect. In most cases, both the linear growth rate and the frequency are decreased by the combination of density and velocity transition layers, i.e., the combined effect of density and velocity gradients stabilizes the KHI. The density gradient effect has an opposite influence on the linear growth rates of the RTI and KHI. Therefore, in real system, there is a competition between the growths of the RTI and KHI which plays an important role in the material transport or mixture. If the widths of density and velocity transition layers have the same dimensionless values, the combined linear growth rate in the combination of KHI and RTI increases with the acceleration but decreases with the width of density (velocity) transition layer.
Communications: Photoinitiated bond dissociation of bromoiodomethane in solution: Comparison of one-photon and two-photon excitations and the formation of iso-CH2Br–I and iso-CH2I–Br
Authors: Tang Kuo-Chun , Peng Jian , Spears Kenneth G. , Sension Roseanne J.
Published: April 2010

Broadband UV-visible femtosecond transient absorption spectroscopy was used to monitor the excited state photochemistry of CH2BrI following one-photon excitation at 266 or 271 nm and two-photon excitation at 395 or 405 nm in 2-butanol. The results for one-photon excitation agree with earlier studies in acetonitrile, showing clear formation of iso-CH2Br–I following cleavage of the C–I bond. In contrast, two-photon excitation at 395 nm results in the appearance of a blueshifted photoproduct absorption band assigned to formation of iso-CH2I–Br following cleavage of the C–Br bond. The results are discussed in the context of prior experimental and theoretical work and the prospects for optical control of bond cleavage.
Composite left/right-handed stacked hole arrays at submillimeter wavelengths
Authors: Wang Shengxiang , Garet Frédéric , Blary Karine , Croënne Charles , Lheurette Eric , Coutaz Jean-Louis , Lippens Didier
Published: April 2010

High-transmissivity composite left/right-handed uniaxial bulk metamaterials were fabricated in a multilayered dielectric/hole metal array technology and experimentally assessed at submillimeter wavelengths (0.4–0.9 THz) by time-domain spectroscopy. From the frequency dependence of the complex scattering parameters, we show the possibility to close the gap between the left- and right-handed dispersion branches by increasing the number of layers from 3 to 5. Such a demonstration paves the way of balance composite propagation characteristics with a gapless transition between the negative and positive values of refractive index at a frequency of 0.5 THz.
Rare frustration of optical supercontinuum generation
Authors: Solli D. R. , Ropers C. , Jalali B.
Published: April 2010

Recent work has shown that optical rogue waves, large bandwidth fluctuations following heavy-tailed statistics, can arise during spectral broadening by stochastic enhancement of nonlinearity. Here, we report the observation of a different form of extreme fluctuations in supercontinuum pulse trains: Pulses of unusually small spectral bandwidth following left-skewed heavy-tailed statistics. Displaying a pulse evolution strongly varying from that of large extremes in supercontinuum, these rogue events appear when spectral broadening is frustrated by competition between presolitonic features within the modulation-instability band. This suppression effect can also be externally induced with a weak control pulse.
Efficient visible to infrared quantum cutting through downconversion with the Er3+–Yb3+ couple in Cs3Y2Br9
Authors: Eilers J. J. , Biner D. , van Wijngaarden J. T. , Krämer K. , Güdel H.-U. , Meijerink A.
Published: April 2010

Downconversion of one visible photon to two near-infrared photons may increase the efficiency of c-Si solar cells by 30%. The lanthanide ion couple Er3+–Yb3+ is well known for efficient upconversion but for the reverse process, downconversion, fast multiphonon relaxation from the F47/2 level has been shown to compete with downconversion. Here we report efficient downconversion for the Er–Yb couple in Cs3Y2Br9. The low phonon energy in this bromide host suppresses multiphonon relaxation and efficient two step energy transfer from the F47/2 level of Er3+ is observed and results in strong 1000 nm emission from Yb3+. Based on emission spectra and luminescence life time measurements an intrinsic downconversion efficiency close to 200% is determined.
Reversible tuning of photonic crystal cavities using photochromic thin films
Authors: Sridharan Deepak , Waks Edo , Solomon Glenn , Fourkas John T.
Published: April 2010

We demonstrate reversible tuning of a photonic crystal cavity resonance using a thin photochromic film composed of spiropyran and polymethylmethacrylate that serves as a photosensitive cladding layer. Exposure of spiropyran to ultraviolet light results in smooth redshift of the cavity resonance that can be reversed by exposure to visible wavelength light. We achieve a reversible resonance shift of up to 2.7 nm, which can be performed locally on individual cavities. The resonance shift over multiple successive UV and visible light exposures is studied to determine the repeatability of the photochromic film.
Sedimentation equilibrium of colloidal platelets in an aligning magnetic field
Authors: Reich Hendrik , Schmidt Matthias
Published: April 2010

We consider colloidal platelets under the influence of gravity and an external aligning (magnetic) field. The system is studied using a fundamental measures density functional theory for model platelets of circular shape and vanishing thickness. In the gravity-free case, the bulk phase diagram exhibits paranematic-nematic phase coexistence that vanishes at an upper critical point upon increasing the strength of the aligning field. Equilibrium sedimentation profiles display a paranematic-nematic interface, which moves to smaller (larger) height upon increasing the strength of gravity (the aligning field). The density near the bottom of the system decreases upon increasing the strength of the aligning field at fixed strength of gravity. Using a simple model for the birefringence properties of equilibrium states, we simulate the color variation with height, as can be observed in samples between crossed polarizers.
Note: Dynamic point spread function for single and multiphoton fluorescence microscopy
Authors: Mondal Partha Pratim , Mandal Subhra , Diaspro Alberto
Published: April 2010

We propose and demonstrate a dynamic point spread function (PSF) for single and multiphoton fluorescence microscopy. The goal is to generate a PSF whose shape and size can be maneuvered from highly localized to elongated one, thereby allowing shallow-to-depth excitation capability during active imaging. The PSF is obtained by utilizing specially designed spatial filter and dynamically altering the filter parameters. We predict potential applications in nanobioimaging and fluorescence microscopy.