bluuebunny/crossref_metadata_2025 huggingface dataset:
Diets of Frugivorous Bats in Montane Rain Forest and Coffee Plantations in Southeastern Chiapas, Mexico
Authors: García‐Estrada Carlos , Damon Anne , Sánchez‐Hernández Cornelio , Soto‐Pinto Lorena , Ibarra‐Núñez Guillermo
Published: November 2011

Frugivorous are one of the main diaspore dispersers in tropical ecosystems, particularly in open areas and sites in the early stages of ecological succession. Frugivorous bat species respond differentially to habitat modification, and in the context of their diaspore dispersal functions it is important to understand species' ecological requirements. We compared the diversity of diaspores, obtained from fecal samples and from fruits carried by frugivorous bats, among five shaded coffee plantations under different management regimes and a montane rain forest in southeastern Chiapas, Mexico. At each site, bats were captured every 2 mo from March 2004 to July 2005, using six mist‐nets, during two consecutive nights. We captured 2589 individuals from 18 frugivorous species, from which we collected 969 fecal samples, containing 42 diaspore species associated with early and late successional plants. Although, we captured more frugivorous bat species in montane rain forest, the number of diaspore species in this site (N=14) was not significantly different from the coffee plantations under different management regimes (16–24). In montane rain forest, Sturnira ludovici fed mainly on Piper auritum, but in coffee plantations ate Peperomia sp., Saurauia madrensis, Solanum chrysotrichum and Solanum diphyllum. Artibeus jamaicensis and Artibeus intermedius feed mostly Cecropia obtusifolia and Ficus cookii in all coffee plantations. We suggest that the presence of frugivorous bats in shaded coffee plantations is favored by trees and shrubs associated with secondary and introduced vegetation that farmers have allowed to grow within or around the plantations.
Bird Assemblages in Anthropogenic Habitats: Identifying a Suitability Gradient for Native Species in the Atlantic Forest
Authors: Zurita Gustavo A. , Bellocq Maria I.
Published: November 2011

Traditional approaches to the study of species persistence in fragmented landscapes generally consider a binary classification of habitat being suitable or unsuitable; however, the range of human‐modified habitats within a region may offer a gradient of habitat suitability (or conservation value) for species. We identified such a gradient by comparing bird assemblages among contrasting land uses (pine plantations of different age, annual crops, clear cuts and cattle pastures) in the Upper Parana Atlantic forest. Bird assemblages and vegetation structure were characterized in an extensive area of 4400 km2 in Argentina and Paraguay during the breeding seasons of 2005–2010. Similarity of bird assemblages between anthropogenic habitats and the native forest and the proportion of forest species increased with vegetation vertical structure, while the proportion of open‐area species decreased. As a consequence, mature tree plantations were the most suitable habitats for forest species and were mainly used by frugivores and bark insectivores. In contrast, open habitats were the least suitable habitat for forest species and were used primarily by insectivores. Human‐created habitats that are structurally complex can be used by a subset of forest species, and may improve functional connectivity and mitigate edge effects. The conservation of large tracks of native forests, however, is critical for the long‐term persistence of the entire bird assemblage, especially for native forest dependent species.
Spillover of Insects from Rain Forest into Adjacent Oil Palm Plantations
Authors: Lucey Jennifer M. , Hill Jane K.
Published: November 2011

Conversion of natural forest to oil palm plantations is a major threat to biodiversity inSoutheastAsia. The retention of natural forest habitats within plantations has been proposed as a method to reduce biodiversity losses in agricultural areas, and we examined whether forest areas resulted in spillover of species into adjacent oil palm plantations. We sampled ants and butterflies along two 2‐km transects across an ecotone from plantation into adjacent forest inSabah,MalaysianBorneo. Species richness of both taxa was reduced in plantations, but to a greater extent in butterflies (54% reduction) than in ants (25% reduction). Butterfly diversity increased in plantations with increasing proximity to forest primarily due to spillover of ‘vagrant’ forest species (whose larval host plants do not occur in plantations), although richness of species that could potentially breed in plantations also increased near to forest. By contrast, ants showed no spillover effects and were less sensitive to land‐use changes, with much higher levels of similarity in species assemblages across habitats than for butterflies. Our results for butterflies suggest that despite the negative impacts of plantations on diversity, proximity to forest could improve diversity in adjacent plantations for some taxa. Spillover of forest species implies that retaining forest areas within plantations may be important for facilitating dispersal of some species through the landscape.
Pyrophthalones as Blue Wavelength Absorbers in Thermoplastic Media
Authors: Natarajan Arunkumar , Burns Andrew , Takemori Michael , Jain Sumeet , Boden Eugene , Vasudevan Vinodkumar , Puthamane Kiran , Naik Shantaram N. , Kuriakose George
Published: November 2011

We have explored the utility of pyrophthalones as violet‐blue light filtering dyes in polymer matrices for wavelengths below 450 nm. Further, we have investigated the photodegradation of these molecules in thermoplastic media and the mechanisms behind their degradation. Finally, a range of additives have been explored to improve the photostability of these molecules to achieve the desired performance.
Influence of Application Amount on Sunscreen Photodegradation in in vitro Sun Protection Factor Evaluation: Proposal of A Skin‐Mimicking Substrate
Authors: Miura Yoshimasa , Hirao Tetsuji , Hatao Masato
Published: November 2011

Widely used polymethylmethacrylate substrates for in vitro sun protection factor (SPF) testing of sunscreens do not mimic the rough surface structure of skin, and in addition, sample loading is less than that used in in vivo SPF testing (2.00 mg cm−2). We have developed a skin‐mimicking substrate (SMS), which has furrows and ridges on its surface, like human skin. A comparison of the photodegradation profiles of sunscreens on commercially available substrates (including SMS) at the recommended application amounts, and on SMS at various application amounts showed that the photodegradation rate of photounstable sunscreen was dependent on the application amount being higher at lower application amounts. SMS at the recommended application amount of 2.00 mg cm−2 provided in vitro SPF values that were comparable with in vivo SPF values. Our results confirm that, in order to develop a reliable in vitro SPF method, which is consistent with in vivo SPF determination, it is important to use the same application amount of sample as in the in vivo method, in order to take proper account of sunscreen photostability.
Modeling and Verification of Melanin Concentration on Human Skin Type
Authors: Karsten Aletta E. , Smit Jacoba E.
Published: November 2011

Lasers are used in the minimalistic or noninvasive diagnosis and treatment of skin disorders. Less laser light reaches the deeper skin layers in dark skin types, due to its higher epidermal melanin concentration compared with lighter skin. Laser–tissue interaction modeling software can correct for this by adapting the dose applied to the skin. This necessitates an easy and reliable method to determine the skin’s type. Noninvasive measurement of the skin’s melanin content is the best method. However, access to samples of all skin types is often limited and skin‐like phantoms are used instead. This study’s objective is to compare experimentally measured absorption features of liquid skin‐like phantoms representing Skin Types I–VI with a realistic skin computational model component of ASAP®. Sample UV–VIS transmittance spectra were measured from 370 to 900 nm and compared with simulated results from ASAP® using the same optical parameters. Results indicated nonmonotonic absorption features towards shorter wavelengths, which may allow for more accurate ways of determining melanin concentration and expected absorption through the epidermal layer. This suggests possible use in representing optical characteristics of real skin. However, a more comprehensive model and phantoms are necessary to account for the effects of sun exposure.
Prevalence of and risk factors for abnormal ankle–brachial index in patients with type 2 diabetes
Authors: LI Xiang , WANG Yu‐zheng , YANG Xiao‐ping , XU Zhang‐rong
Published: November 2011

Background:  The aim of the present study was to examine abnormalities in the ankle–brachial index (ABI) and related risk factors in patients with type 2 diabetes.

Methods:  Between September 2003 and June 2010, the ABI was determined in 3924 outpatients attending the Diabetes Center of the People’s Liberation Army 306th Hospital. In addition, demographic and laboratory data were collected. The risk factors for an abnormal ABI were determined using univariate and stepwise logistic regression analysis.

Results:  The ABI was normal (0.91–1.3) in 93.1% of patients, low (<0.9) in 5.2%, and high (>1.3) in 1.7%. The prevalence of abnormal lower ABI was greater in elderly (≥ 65 years) patients (12.2%) than in younger (< 65 years) patients (3.6%). Using normal ABI as the reference, low ABI in younger patients was found to be independently associated with HbA1c, the urinary albumin:creatinine ratio, diabetic peripheral neuropathy, diabetic retinopathy, and cerebrovascular disease. A low ABI in elderly patients was found to be independently associated with age, smoking, HbA1c, uric acid, total cholesterol, diabetic peripheral neuropathy, diabetic retinopathy, diabetic nephropathy and cerebrovascular disease. A high ABI in younger patients was associated with being male.

Conclusions:  The prevalence of an abnormal ABI was high in patients with type 2 diabetes, especially elderly patients. Early identification and intensive treatment are needed to improve the quality of life and overall prognosis of patients with type 2 diabetes.
Quantifying individual variation in reaction norms: how study design affects the accuracy, precision and power of random regression models
Authors: van de Pol Martijn
Published: November 2011

1. Quantifying individual heterogeneity in plasticity is becoming common in studies of evolutionary ecology, climate change ecology and animal personality. Individual variation in reaction norms is typically quantified using random effects in a mixed modelling framework. However, little is known about what sampling effort and design provide sufficient accuracy, precision and power.

2. I developed ‘odprism’, an easy‐to‐use software package for the statistical language R, which can be used to investigate the accuracy, precision and power of random regression models for various types of data structures. Moreover, I conducted simulations to derive rules‐of‐thumb for four design decisions that biologists often face.

3. First, I investigated the trade‐off between sampling many individuals a few times versus sampling few individuals often. Generally, at least 40 individuals should be sampled with a total sample size of at least 1000 to obtain accurate and precise estimates of individual variation in elevation and slopes of linear reaction norms and their correlation. Contrasting a previous recommendation, it is worthwhile to bias the ratio of number of individuals over replicates towards sampling more individuals.

4. Second, I considered how the range of environmental conditions over which individuals are sampled affects the optimal sampling strategy. I show that when all individuals experience the same conditions during a sampling event, sampling each individual only twice should be strictly avoided.

5. Third, I examined the case where the number of replicates per individual is constrained by their lifespan, as is common when sampling annual traits in the wild. I show that for a given sampling effort, it is much easier to detect individual variation in reaction norms for long‐lived than for short‐lived species.

6. Fourth, I investigated the performance of random regression models when studying traits under selection. Reassuringly, directional viability selection barely caused any bias in estimates of variance components.

7. Random regression models are inherently data hungry, and reviewing the literature shows that particularly behavioural studies have low sampling effort. Therefore, the software and rules‐of‐thumbs I identified for designing reaction‐norm studies should help researchers make more informed choices, which likely improve the reliability and interpretation of plasticity studies.
Factors Driving Potential Ammonia Oxidation in Canadian Arctic Ecosystems: Does Spatial Scale Matter?
Authors: Banerjee Samiran , Siciliano Steven D.
Published: November 2011

Ammonia oxidation is a major process in nitrogen cycling, and it plays a key role in nitrogen limited soil ecosystems such as those in the arctic. Although mm-scale spatial dependency of ammonia oxidizers has been investigated, little is known about the field-scale spatial dependency of aerobic ammonia oxidation processes and ammonia-oxidizing archaeal and bacterial communities, particularly in arctic soils. The purpose of this study was to explore the drivers of ammonia oxidation at the field scale in cryosols (soils with permafrost within 1 m of the surface). We measured aerobic ammonia oxidation potential (both autotrophic and heterotrophic) and functional gene abundance (bacterial
amoA
and archaeal
amoA
) in 279 soil samples collected from three arctic ecosystems. The variability associated with quantifying genes was substantially less than the spatial variability observed in these soils, suggesting that molecular methods can be used reliably evaluate spatial dependency in arctic ecosystems. Ammonia-oxidizing archaeal and bacterial communities and aerobic ammonia oxidation were spatially autocorrelated. Gene abundances were spatially structured within 4 m, whereas biochemical processes were structured within 40 m. Ammonia oxidation was driven at small scales (<1m) by moisture and total organic carbon, whereas gene abundance and other edaphic factors drove ammonia oxidation at medium (1 to 10 m) and large (10 to 100 m) scales. In these arctic soils heterotrophs contributed between 29 and 47% of total ammonia oxidation potential. The spatial scale for aerobic ammonia oxidation genes differed from potential ammonia oxidation, suggesting that in arctic ecosystems edaphic, rather than genetic, factors are an important control on ammonia oxidation.
Differential Protection of Cry1Fa Toxin against Spodoptera frugiperda Larval Gut Proteases by Cadherin Orthologs Correlates with Increased Synergism
Authors: Rahman Khalidur , Abdullah Mohd Amir F. , Ambati Suresh , Taylor Milton D. , Adang Michael J.
Published: November 2011

The Cry proteins produced byBacillus thuringiensis(Bt) are the most widely used biopesticides effective against a range of crop pests and disease vectors. Like chemical pesticides, development of resistance is the primary threat to the long-term efficacy of Bt toxins. Recently discovered cadherin-based Bt Cry synergists showed the potential to augment resistance management by improving efficacy of Cry toxins. However, the mode of action of Bt Cry synergists is thus far unclear. Here we elucidate the mechanism of cadherin-based Cry toxin synergism utilizing two cadherin peptides,Spodoptera frugiperdaCad (SfCad) andManduca sextaCad (MsCad), which differentially enhance Cry1Fa toxicity toSpodoptera frugiperdaneonates. We show that differential SfCad- and MsCad-mediated protection of Cry1Fa toxin in theSpodoptera frugiperdamidgut correlates with differential Cry1Fa toxicity enhancement. Both peptides exhibited high affinity for Cry1Fa toxin and an increased rate of Cry1Fa-induced pore formation inS. frugiperda. However, only SfCad bound theS. frugiperdabrush border membrane vesicle and more effectively prolonged the stability of Cry1Fa toxin in the gut, explaining higher Cry1Fa enhancement by this peptide. This study shows that cadherin fragments may enhanceB. thuringiensistoxicity by at least two different mechanisms or a combination thereof: (i) protection of Cry toxin from protease degradation in the insect midgut and (ii) enhancement of pore-forming ability of Cry toxin.
Cow Teat Skin, a Potential Source of Diverse Microbial Populations for Cheese Production
Authors: Verdier-Metz Isabelle , Gagne Geneviève , Bornes Stéphanie , Monsallier Françoise , Veisseire Philippe , Delbès-Paus Céline , Montel Marie-Christine
Published: November 2011

The diversity of the microbial community on cow teat skin was evaluated using a culture-dependent method based on the use of different dairy-specific media, followed by the identification of isolates by 16S rRNA gene sequencing. This was combined with a direct molecular approach by cloning and 16S rRNA gene sequencing. This study highlighted the large diversity of the bacterial community that may be found on teat skin, where 79.8% of clones corresponded to various unidentified species as well as 66 identified species, mainly belonging to those commonly found in raw milk (
Enterococcus
,
Pediococcus
,
Enterobacter
,
Pantoea
,
Aerococcus
, and
Staphylococcus
). Several of them, such as nonstarter lactic acid bacteria (NSLAB),
Staphylococcus
, and
Actinobacteria
, may contribute to the development of the sensory characteristics of cheese during ripening. Therefore, teat skin could be an interesting source or vector of biodiversity for milk. Variations of microbial counts and diversity between the farms studied have been observed. Moreover,
Staphylococcus auricularis
,
Staphylococcus devriesei
,
Staphylococcus arlettae
,
Streptococcus bovis
,
Streptococcus equinus
,
Clavibacter michiganensis
,
Coprococcus catus
, or
Arthrobacter gandavensis
commensal bacteria of teat skin and teat canal, as well as human skin, are not common in milk, suggesting that there is a breakdown of microbial flow from animal to milk. It would then be interesting to thoroughly study this microbial flow from teat to milk.
Distinct Transcriptional Profiles and Phenotypes Exhibited by Escherichia coli O157:H7 Isolates Related to the 2006 Spinach-Associated Outbreak
Authors: Parker Craig T. , Kyle Jennifer L. , Huynh Steven , Carter Michelle Q. , Brandl Maria T. , Mandrell Robert E.
Published: November 2011

In 2006, a large outbreak of
Escherichia coli
O157:H7 was linked to the consumption of ready-to-eat bagged baby spinach in the United States. The likely sources of preharvest spinach contamination were soil and water that became contaminated via cattle or feral pigs in the proximity of the spinach fields. In this study, we compared the transcriptional profiles of 12
E. coli
O157:H7 isolates that possess the same two-enzyme pulsed-field gel electrophoresis (PFGE) profile and are related temporally or geographically to the above outbreak. These
E. coli
O157:H7 isolates included three clinical isolates, five isolates from separate bags of spinach, and single isolates from pasture soil, river water, cow feces, and a feral pig. The three clinical isolates and two spinach bag isolates grown in cultures to stationary phase showed decreased expression of many σ
S
-regulated genes, including
gadA
,
osmE
,
osmY
, and
katE
, compared with the soil, water, cow, feral pig, and the other three spinach bag isolates. The decreased expression of these σ
S
-regulated genes was correlated with the decreased resistance of the isolates to acid stress, osmotic stress, and oxidative stress but increases in scavenging ability. We also observed that intraisolate variability was much more pronounced among the clinical and spinach isolates than among the environmental isolates. Together, the transcriptional and phenotypic differences of the spinach outbreak isolates of
E. coli
O157:H7 support the hypothesis that some variants within the spinach bag retained characteristics of the preharvest isolates, whereas other variants with altered gene expression and phenotypes infected the human host.
Metagenomic Analysis of Stress Genes in Microbial Mat Communities from Antarctica and the High Arctic
Authors: Varin Thibault , Lovejoy Connie , Jungblut Anne D. , Vincent Warwick F. , Corbeil Jacques
Published: November 2011

Polar and alpine microbial communities experience a variety of environmental stresses, including perennial cold and freezing; however, knowledge of genomic responses to such conditions is still rudimentary. We analyzed the metagenomes of cyanobacterial mats from Arctic and Antarctic ice shelves, using high-throughput pyrosequencing to test the hypotheses that consortia from these extreme polar habitats were similar in terms of major phyla and subphyla and consequently in their potential responses to environmental stresses. Statistical comparisons of the protein-coding genes showed similarities between the mats from the two poles, with the majority of genes derived fromProteobacteriaandCyanobacteria; however, the relative proportions differed, with cyanobacterial genes more prevalent in the Antarctic mat metagenome. Other differences included a higher representation ofActinobacteriaandAlphaproteobacteriain the Arctic metagenomes, which may reflect the greater access to diasporas from both adjacent ice-free lands and the open ocean. Genes coding for functional responses to environmental stress (exopolysaccharides, cold shock proteins, and membrane modifications) were found in all of the metagenomes. However, in keeping with the greater exposure of the Arctic to long-range pollutants, sequences assigned to copper homeostasis genes were statistically (30%) more abundant in the Arctic samples. In contrast, more reads matching the sigma B genes were identified in the Antarctic mat, likely reflecting the more severe osmotic stress during freeze-up of the Antarctic ponds. This study underscores the presence of diverse mechanisms of adaptation to cold and other stresses in polar mats, consistent with the proportional representation of major bacterial groups.
Functions of the Duplicated
hik31
Operons in Central Metabolism and Responses to Light, Dark, and Carbon Sources in Synechocystis sp. Strain PCC 6803
Authors: Nagarajan Sowmya , Sherman Debra M. , Shaw Isaac , Sherman Louis A.
Published: November 2011

There are two closely related
hik31
operons involved in signal transduction on the chromosome and the pSYSX plasmid in the cyanobacterium
Synechocystis
sp. strain PCC 6803. We studied the growth, cell morphology, and gene expression in operon and
hik
mutants for both copies, under different growth conditions, to examine whether the duplicated copies have the same or different functions and gene targets and whether they are similarly regulated. Phenotype analysis suggested that both operons regulated common and separate targets in the light and the dark. The chromosomal operon was involved in the negative control of autotrophic events, whereas the plasmid operon was involved in the positive control of heterotrophic events. Both the plasmid and double operon mutant cells were larger and had division defects. The growth data also showed a regulatory role for the chromosomal
hik
gene under high-CO
2
conditions and the plasmid operon under low-O
2
conditions. Metal stress experiments indicated a role for the chromosomal
hik
gene and operon in mediating Zn and Cd tolerance, the plasmid operon in Co tolerance, and the chromosomal operon and plasmid
hik
gene in Ni tolerance. We conclude that both operons are differentially and temporally regulated. We suggest that the chromosomal operon is the primarily expressed copy and the plasmid operon acts as a backup to maintain appropriate gene dosages. Both operons share an integrated regulatory relationship and are induced in high light, in glucose, and in active cell growth. Additionally, the plasmid operon is induced in the dark with or without glucose.
E622, a Miniature, Virulence-Associated Mobile Element
Authors: Stavrinides John , Kirzinger Morgan W. B. , Beasley Federico C. , Guttman David S.
Published: November 2011

Miniature inverted terminal repeat elements (MITEs) are nonautonomous mobile elements that have a significant impact on bacterial evolution. Here we characterize E622, a 611-bp virulence-associated MITE from
Pseudomonas syringae
, which contains no coding region but has almost perfect 168-bp inverted repeats. Using an antibiotic coupling assay, we show that E622 is transposable and can mobilize an antibiotic resistance gene contained between its borders. Its predicted parent element, designated Tn
E622
, has a typical transposon structure with a three-gene operon, consisting of resolvase, integrase, and
exeA
-like genes, which is bounded by the same terminal inverted repeats as E622. A broader genome level survey of the E622/Tn
E622
inverted repeats identified homologs in
Pseudomonas
,
Salmonella
,
Shewanella
,
Erwinia
,
Pantoea
, and the cyanobacteria
Nostoc
and
Cyanothece
, many of which appear to encompass known virulence genes, including genes encoding toxins, enzymes, and type III secreted effectors. Its association with niche-specific genetic determinants, along with its persistence and evolutionary diversification, indicates that this mobile element family has played a prominent role in the evolution of many agriculturally and clinically relevant pathogenic bacteria.
Evidence that the Folate-Dependent Proteins YgfZ and MnmEG Have Opposing Effects on Growth and on Activity of the Iron-Sulfur Enzyme MiaB
Authors: Waller Jeffrey C. , Ellens Kenneth W. , Hasnain Ghulam , Alvarez Sophie , Rocca James R. , Hanson Andrew D.
Published: November 2011

The folate-dependent protein YgfZ of
Escherichia coli
participates in the synthesis and repair of iron-sulfur (Fe-S) clusters; it belongs to a family of enzymes that use folate to capture formaldehyde units. Ablation of
ygfZ
is known to reduce growth, to increase sensitivity to oxidative stress, and to lower the activities of MiaB and other Fe-S enzymes. It has been reported that the growth phenotype can be suppressed by disrupting the tRNA modification gene
mnmE
. We first confirmed the latter observation using deletions in a simpler, more defined genetic background. We then showed that deleting
mnmE
substantially restores MiaB activity in
ygfZ
deletant cells and that overexpressing MnmE with its partner MnmG exacerbates the growth and MiaB activity phenotypes of the
ygfZ
deletant. MnmE, with MnmG, normally mediates a folate-dependent transfer of a formaldehyde unit to tRNA, and the MnmEG-mediated effects on the phenotypes of the Δ
ygfZ
mutant apparently require folate, as evidenced by the effect of eliminating all folates by deleting
folE
. The expression of YgfZ was unaffected by deleting
mnmE
or overexpressing MnmEG or by folate status. Since formaldehyde transfer is a potential link between MnmEG and YgfZ, we inactivated formaldehyde detoxification by deleting
frmA
. This deletion had little effect on growth or MiaB activity in the Δ
ygfZ
strain in the presence of formaldehyde, making it unlikely that formaldehyde alone connects the actions of MnmEG and YgfZ. A more plausible explanation is that MnmEG erroneously transfers a folate-bound formaldehyde unit to MiaB and that YgfZ reverses this.
Current and long-term spousal caregiving and onset of cardiovascular disease
Authors: Capistrant Beatrix Davoli , Moon J Robin , Berkman Lisa F , Glymour M Maria
Published: November 2011

Background

Prior evidence suggests that caregiving may increase risk of cardiovascular disease (CVD) onset. This association has never been examined in a nationally (USA) representative sample, and prior studies could not fully control for socioeconomic confounders. This paper seeks to estimate the association between spousal caregiving and incident CVD in older Americans.

Methods

Married, CVD-free Health and Retirement Study respondents aged 50+ years (n=8472) were followed up to 8 years (1669 new stroke or heart disease diagnoses). Current caregiving exposure was defined as assisting a spouse with basic or instrumental activities of daily living ≥14 h/week according to the care recipients' report in the most recent prior biennial survey; we define providing ≥14 h/week of care at two consecutive biennial surveys as ‘long-term caregiving’. Inverse probability weighted discrete-time hazard models with time-updated exposure and covariate information (including socioeconomic and cardiovascular risk factors) were used to estimate the effect of caregiving on incident CVD.

Results

Caregiving significantly predicted CVD incidence (HR=1.35, 95% CI 1.06 to 1.68) in the population overall. Long-term caregiving was associated with double the risk of CVD onset (HR=1.95, 95% CI 1.19 to 3.18). This association for long-term care givers varied significantly by race (p<0.01): caregiving predicted CVD onset for white (HR=2.37, 95% CI 1.43 to 3.92) but not for non-white (HR=0.28, 95% CI 0.06 to 1.28).

Conclusions

Spousal caregiving independently predicted risk of CVD in a large sample of US adults. There was significant evidence that the effect for long-term care givers differs for non-whites and white.
Understanding the link between environmental exposures and health: does the exposome promise too much?: Figure 1
Authors: Peters Annette , Hoek Gerard , Katsouyanni Klea
Published: November 2011

Environmental exposures affecting human health range from complex mixtures, such as environmental tobacco smoke, ambient particulate matter air pollution and chlorination by products in drinking water, to hazardous chemicals, such as lead, and polycyclic aromatic hydrocarbons, such as benz(a)pyrene. The exposome has been proposed to complement the genome and be the totality of all environmental exposures of an individual over his or her lifetime. However, if measurements of the exposome in biological samples are the sole tool for exposure assessment there are a number of limitations. First, it has limited utility for fully capturing the impact of complex mixtures such environmental tobacco smoke or particulate matter air pollution. Second, a number of relevant environmental exposures such as noise, heat or electromagnetic fields do not have direct correlates as metabolites or protein adducts, but there is important evidence linking them with health effects. Third, functional genomic changes are likely in many instances to be both a susceptibility factor and a marker of internal doses in response to environmental exposures. Fourth, internal dose measurements of environmental exposures might have lost the distinct signature of the relevant sources. This paper emphasises the obligation of environmental epidemiology to provide robust evidence to assist timely and sufficient protection of vulnerable subgroups of populations from environmental hazards. Therefore, in applying the exposome concept to environmental health problems, a strong link with the external environment needs to be maintained.
Mode Order Dependent Q-Spoiling Behavior in a Coated Cylindrical Microcavity Laser
Authors: Moon Hee-Jong
Published: November 2011

Mode order dependent Q-spoiling of lasing was investigated in a dielectric inner-coated cylindrical capillary filled with a dye-doped liquid. The behavior of blue-shift of lasing spectra with the coating thickness was highly dependent on the mode order. The measured quality factors Q's were quantitatively compared with those deduced from a Wentzel–Kramers–Brillouin (WKB) approximation model and a simplified multiple scattering formalism.
Heat Resistant Transparent Flexible Film Obtained from Two Tetraphenylphosphonium Modified Smectites with Different Particle Size
Authors: Kawasaki Kazunori , Ebina Takeo , Hanaoka Taka-aki , Tsuda Hajime , Motegi Katsumi
Published: November 2011

Transparent clay films were prepared using tetraphenyl phosphonium (TPP) modified smectites (TPP-SA, TPP-HE, and TPP-SA-HE), which were prepared by ion exchange of either synthetic saponite (SA) or synthetic hectorite (HE) as well as a mixture of these two kinds of smectites (SA-HE) with TPP-bromide (TPP-Br). Uniform liquid dispersions of these TPP-smectites were successfully prepared by adding N,N-dimethylformamide (DMF) to hydrous gels of TPP-smectites. Finally, transparent self-supported films of about 30 µm thickness were prepared by casting these dispersions. From the optical studies, it was confirmed that the transparent clay films maintained their optical transparency in the visible range even after annealing at 350 °C for an hour. Particularly, haze value of the TPP-SA-HE film decreased by one-third compared to TPP-SA, and it was also confirmed that the flexibility of TPP-SA-HE film was better than that of TPP-HE. From the cross-sectional scanning electron microscope (SEM) images, it was confirmed that TPP-SA film has large voids, which causes scattering of light compared to TPP-HE. Finally, the average void size was reduced by mixing these two TPP-smectites with different particle size.
Effects of a Cylindrical Cavity on the Etendue of a Light Source
Authors: Lee Ui-Hyung , Ju Young-Gu
Published: November 2011

This paper proposes that the cylindrical cavity around a circular light source can decrease the divergence angle without changing the emission energy and source size. This result can provide a way to reduce the etendue of the light source by scrambling the rays inside the cavity with a lossless scattering surface. The experiment demonstrated that the metallic cavity around the surface source reduced the divergence angle. However, the metallic surface also absorbed quite a large portion of the light energy. The Lambertian nature of the sidewall surface changed the directions of the rays into horizontal directions. It increased the number of reflections inside the cavity and amplified the small amount of absorption at a single reflection. This effect of the cavity on the etendue of the light source can contribute to providing more design flexibility in various lighting applications.
Endothelial dysfunction as a cellular mechanism for vascular failure
Authors: Hirase Tetsuaki , Node Koichi
Published: November 2011

The regulation of vascular tone, vascular permeability, and thromboresistance is essential to maintain blood circulation and therefore tissue environments under physiological conditions. Atherogenic stimuli, including diabetes, dyslipidemia, and oxidative stress, induce vascular dysfunction, leading to atherosclerosis, which is a key pathological basis for cardiovascular diseases such as ischemic heart disease and stroke. We have proposed a novel concept termed “vascular failure” to comprehensively recognize the vascular dysfunction that contributes to the development of cardiovascular diseases. Vascular endothelial cells form the vascular endothelium as a monolayer that covers the vascular lumen and serves as an interface between circulating blood and immune cells. Endothelial cells regulate vascular function in collaboration with smooth muscle cells. Endothelial dysfunction under pathophysiological conditions contributes to the development of vascular dysfunction. Here, we address the barrier function and microtubule function of endothelial cells. Endothelial barrier function, mediated by cell-to-cell junctions between endothelial cells, is regulated by small GTPases and kinases. Microtubule function, regulated by the acetylation of tubulin, a component of the microtubules, is a target of atherogenic stimuli. The elucidation of the molecular mechanisms of endothelial dysfunction as a cellular mechanism for vascular failure could provide novel therapeutic targets of cardiovascular diseases.
Aldosterone-induced brain MAPK signaling and sympathetic excitation are angiotensin II type-1 receptor dependent
Authors: Zhang Zhi-Hua , Yu Yang , Wei Shun-Guang , Felder Robert B.
Published: November 2011

Angiotensin II (ANG II)-induced mitogen-activated protein kinase (MAPK) signaling upregulates angiotensin II type-1 receptors (AT1R) in hypothalamic paraventricular nucleus (PVN) and contributes to AT1R-mediated sympathetic excitation in heart failure. Aldosterone has similar effects to increase AT1R expression in the PVN and sympathetic drive. The present study was undertaken to determine whether aldosterone also activates the sympathetic nervous system via MAPK signaling and, if so, whether its effect is independent of ANG II and AT1R. In anesthetized rats, a 4-h intravenous infusion of aldosterone induced increases ( P < 0.05) in phosphorylated (p-) p44/42 MAPK in PVN, PVN neuronal excitation, renal sympathetic nerve activity (RSNA), mean blood pressure (MBP), and heart rate (HR). Intracerebroventricular or bilateral PVN microinjection of the p44/42 MAPK inhibitor PD-98059 reduced the aldosterone-induced RSNA, HR, and MBP responses. Intracerebroventricular pretreatment (5 days earlier) with pooled small interfering RNAs targeting p44/42 MAPK reduced total and p-p44/42 MAPK, aldosterone-induced c-Fos expression in the PVN, and the aldosterone-induced increases in RSNA, HR, and MBP. Intracerebroventricular infusion of either the mineralocorticoid receptor antagonist RU-28318 or the AT1R antagonist losartan blocked aldosterone-induced phosphorylation of p44/42 MAPK and prevented the increases in RSNA, HR, and MBP. These data suggest that aldosterone-induced sympathetic excitation depends upon that AT1R-induced MAPK signaling in the brain. The short time course of this interaction suggests a nongenomic mechanism, perhaps via an aldosterone-induced transactivation of the AT1R as described in peripheral tissues.
Tempol modulates changes in xenobiotic permeability and occludin oligomeric assemblies at the blood-brain barrier during inflammatory pain
Authors: Lochhead Jeffrey J. , McCaffrey Gwen , Sanchez-Covarrubias Lucy , Finch Jessica D. , DeMarco Kristin M. , Quigley Colleen E. , Davis Thomas P. , Ronaldson Patrick T.
Published: November 2011

Our laboratory has shown that λ-carrageenan-induced peripheral inflammatory pain (CIP) can alter tight junction (TJ) protein expression and/or assembly leading to changes in blood-brain barrier xenobiotic permeability. However, the role of reactive oxygen species (ROS) and subsequent oxidative stress during CIP is unknown. ROS (i.e., superoxide) are known to cause cellular damage in response to pain/inflammation. Therefore, we examined oxidative stress-associated effects at the blood-brain barrier (BBB) in CIP rats. During CIP, increased staining of nitrosylated proteins was detected in hind paw tissue and enhanced presence of protein adducts containing 3-nitrotyrosine occurred at two molecular weights (i.e., 85 and 44 kDa) in brain microvessels. Tempol, a pharmacological ROS scavenger, attenuated formation of 3-nitrotyrosine-containing proteins in both the hind paw and in brain microvessels when administered 10 min before footpad injection of λ-carrageenan. Similarly, CIP increased 4-hydroxynoneal staining in brain microvessels and this effect was reduced by tempol. Brain permeability to [14C]sucrose and [3H]codeine was increased, and oligomeric assemblies of occludin, a critical TJ protein, were altered after 3 h CIP. Tempol attenuated both [14C]sucrose and [3H]codeine brain uptake as well as protected occludin oligomers from disruption in CIP animals, suggesting that ROS production/oxidative stress is involved in modulating BBB functional integrity during pain/inflammation. Interestingly, tempol administration reduced codeine analgesia in CIP animals, indicating that oxidative stress during pain/inflammation may affect opioid delivery to the brain and subsequent efficacy. Taken together, our data show for the first time that ROS pharmacological scavenging is a viable approach for maintaining BBB integrity and controlling central nervous system drug delivery during acute inflammatory pain.
Cell-to-cell coupling in engineered pairs of rat ventricular cardiomyocytes: relation between Cx43 immunofluorescence and intercellular electrical conductance
Authors: McCain Megan L. , Desplantez Thomas , Geisse Nicholas A. , Rothen-Rutishauser Barbara , Oberer Helene , Parker Kevin Kit , Kleber Andre G.
Published: November 2011

Gap junctions are composed of connexin (Cx) proteins, which mediate intercellular communication. Cx43 is the dominant Cx in ventricular myocardium, and Cx45 is present in trace amounts. Cx43 immunosignal has been associated with cell-to-cell coupling and electrical propagation, but no studies have directly correlated Cx43 immunosignal to electrical cell-to-cell conductance, gj, in ventricular cardiomyocyte pairs. To assess the correlation between Cx43 immunosignal and gj, we developed a method to determine both parameters from the same cell pair. Neonatal rat ventricular cardiomyocytes were seeded on micropatterned islands of fibronectin. This allowed formation of cell pairs with reproducible shapes and facilitated tracking of cell pair locations. Moreover, cell spreading was limited by the fibronectin pattern, which allowed us to increase cell height by reducing the surface area of the pattern. Whole cell dual voltage clamp was used to record gj of cell pairs after 3–5 days in culture. Fixation of cell pairs before removal of patch electrodes enabled preservation of cell morphology and offline identification of patched pairs. Subsequently, pairs were immunostained, and the volume of junctional Cx43 was quantified using confocal microscopy, image deconvolution, and three-dimensional reconstruction. Our results show a linear correlation between gj and Cx43 immunosignal within a range of 8–50 nS.
Prostaglandin E2enhances interleukin-8 production via EP4 receptor in human pulmonary microvascular endothelial cells
Authors: Aso Hiromichi , Ito Satoru , Mori Akemi , Morioka Masataka , Suganuma Nobukazu , Kondo Masashi , Imaizumi Kazuyoshi , Hasegawa Yoshinori
Published: November 2011

Prostaglandin E2(PGE2) is a bioactive prostanoid implicated in the inflammatory processes of acute lung injury/acute respiratory distress syndrome. This study investigated whether PGE2can induce production of interleukin (IL)-8, the major chemokine for neutrophil activation, from human pulmonary microvascular endothelial cells (HPMVECs). PGE2significantly enhanced IL-8 protein production with increases in IL-8 mRNA expression and intracellular cAMP levels. HPMVECs expressed only EP4 receptor mRNA. The PGE2effects were mimicked by a selective EP4 receptor agonist, ONO-AE1–329, and inhibited by a selective EP4 receptor antagonist, ONO-AE3–208, or a protein kinase A inhibitor, Rp-adenosine 3',5'-cyclic monophosphorothioate triethylamine salt. The specific agonist for EP1, EP2, or EP3 receptor did not induce IL-8 production. PGE2-induced IL-8 production was accompanied by p38 phosphorylation and was significantly inhibited by a p38 inhibitor, SB-203580, but not by an ERK1/2 inhibitor, U-0126, or a JNK inhibitor, SP-600125. Additionally, PGE2increased cyclooxygenase-2 expression with no change in constitutive cyclooxygenase-1 expression, suggesting possible involvement of an autocrine or paracrine manner. In conclusion, PGE2enhances IL-8 production via EP4 receptor coupled to Gsprotein in HPMVECs. Activation of the cAMP/protein kinase A pathway, followed by p38 activation, is essential for these mechanisms. Because neutrophils play a critical role in the inflammation of acute lung injury/acute respiratory distress syndrome, IL-8 released from the pulmonary microvasculature in response to PGE2may contribute to pathophysiology of this disease.
Metabolomic NMR Fingerprinting to Identify and Predict Survival of Patients with Metastatic Colorectal Cancer
Authors: Bertini Ivano , Cacciatore Stefano , Jensen Benny V. , Schou Jakob V. , Johansen Julia S. , Kruhøffer Mogens , Luchinat Claudio , Nielsen Dorte L. , Turano Paola
Published: November 2011

Earlier detection of patients with metastatic colorectal cancer (mCRC) might improve their treatment and survival outcomes. In this study, we used proton nuclear magnetic resonance (1H-NMR) to profile the serum metabolome in patients with mCRC and determine whether a disease signature may exist that is strong enough to predict overall survival (OS). In 153 patients with mCRC and 139 healthy subjects from three Danish hospitals, we profiled two independent sets of serum samples in a prospective phase II study. In the training set, 1H-NMR metabolomic profiling could discriminate patients with mCRC from healthy subjects with a cross-validated accuracy of 100%. In the validation set, 96.7% of subjects were correctly classified. Patients from the training set with maximally divergent OS were chosen to construct an OS predictor. After validation, patients predicted to have short OS had significantly reduced survival (HR, 3.4; 95% confidence interval, 2.06–5.50; P = 1.33 × 10−6). A number of metabolites concurred with the 1H-NMR fingerprint of mCRC, offering insights into mCRC metabolic pathways. Our findings establish that 1H-NMR profiling of patient serum can provide a strong metabolomic signature of mCRC and that analysis of this signature may offer an independent tool to predict OS. Cancer Res; 72(1); 356–64. ©2011 AACR.
Right Ventricular Injury in ST-Elevation Myocardial Infarction
Authors: Grothoff Matthias , Elpert Christian , Hoffmann Janine , Zachrau Johannes , Lehmkuhl Lukas , de Waha Suzanne , Desch Steffen , Eitel Ingo , Mende Meinhard , Thiele Holger , Gutberlet Matthias
Published: November 2011

Background—

Patients with right ventricular injury (RVI) complicating ST-elevation myocardial infarction (STEMI) have impaired prognosis, but it is unclear which patients are at risk of developing RVI. Cardiac magnetic resonance can identify these patients and might add important information on risk stratification, prognosis, and treatment. Aims were to determine the predictors and the prognostic significance of RVI assessed by wall motion abnormalities, edema, myocardial salvage index, and delayed enhancement in acute reperfused STEMI.

Methods and Results—

We studied 450 patients 1–4 days after primary angioplasty in STEMI. T2-weighted and delayed-enhancement cardiac magnetic resonance was used for visualizing edema and scar to calculate myocardial salvage index. Cine-imaging was performed to assess wall motion abnormalities, which, in combination with edema, were considered diagnostic for RVI. Patients with RVI were compared with matched patients with isolated left ventricular infarction. The primary end point was the occurrence of a major adverse cardiac event: a composite of death, reinfarction, and congestive heart failure after a median follow-up period of 20.9 months. RVI was present in 69 patients, and 41 of 69 showed myocardial necrosis. In a multivariable stepwise forward logistic regression analysis, a high RV myocardial mass (odds ratio, 2.06; 95% confidence interval, 1.18–3.58;
P
=0.012) and a low Thrombolysis In Myocardial Infarction flow before angioplasty (odds ratio, 0.50; 95% confidence interval, 0.32–0.76;
P
=0.011) were associated with RVI. Cox regression analysis revealed RVI as the most statistically significant predictor of time to major adverse cardiac events (hazard-ratio, 3.36; 95% confidence interval, 1.99–5.66;
P
<0.001).

Conclusions—

RVI detected by cardiac magnetic resonance is a strong and independent predictor of clinical outcome after acute reperfused STEMI.

Clinical Trial Registration—

URL:
http://www.clinicaltrials.gov
. Unique identifier: NCT01359306.