Coastal freshwater wetlands squeezed between migrating salt marshes and working lands

Creative solutions are needed to sustain the diversity of coastal wetland ecosystems as sea levels rise.

Are nitrogen and carbon cycle processes impacted by common stream antibiotics? A comparative assessment of single vs. mixture exposures

A variety of antibiotics are ubiquitous in all freshwater ecosystems that receive wastewater. A wide variety of antibiotics have been developed to kill problematic bacteria and fungi through targeted application, and their use has contributed significantly to public health and livestock management. Unfortunately, a substantial fraction of the antibiotics applied to humans, pets and livestock end up in wastewater, and ultimately many of these chemicals enter freshwater ecosystems. The effect of adding chemicals that are intentionally designed to kill microbes, on freshwater microbial communities remains poorly understood. There are reasons to be concerned, as microbes play an essential role in nutrient uptake, carbon fixation and denitrification in freshwater ecosystems. Chemicals that reduce or alter freshwater microbial communities might reduce their capacity to degrade the excess nutrients and organic matter that characterize wastewater. We performed a laboratory experiment in which we exposed microbial community from unexposed stream sediments to three commonly detected antibiotics found in urban wastewater and urban streams (sulfamethoxazole, danofloxacin, and erythromycin). We assessed how the form and concentration of inorganic nitrogen, microbial carbon, and nitrogen cycling processes changed in response to environmentally relevant doses (10 μg/L) of each of these antibiotics individually and in combination. We expected to find that all antibiotics suppressed rates of microbial mineralization and nitrogen transformations and we anticipated that this suppression of microbial activity would be greatest in the combined treatment. Contrary to our expectations we measured few significant changes in microbially mediated functions in response to our experimental antibiotic dosing. We found no difference in functional gene abundance of key nitrogen cycling genes nosZ, mcrA, nirK, and amoA genes, and we measured no treatment effects on NO3- uptake or N2O, N2, CH4, CO2 production over the course of our seven-day experiment. In the mixture treatment, we measured significant increases in NH4+ concentrations over the first 24 hours of the experiment, which were indistinguishable from controls within six hours. Our results suggest remarkable community resistance to pressure antibiotic exposure poses on naïve stream sediments.

Outdoor urban nanomaterials: The emergence of a new, integrated, and critical field of study

Engineered nanomaterials (ENMs) are currently widely incorporated in the outdoor urban environmental fabric and numerous new applications and products containing ENMs are expected in the future. As has been shown repeatedly, products containing ENMs have the potential, at some point in their lifetime, to release ENMs into their surrounding environment. However, the expanding body in environmental nanomaterial research has not yet shifted toward ENMs in the context of the complex outdoor urban environment. This is especially surprising because the world's human populations are on a steady march toward more and more urbanization and technological development, accompanied with increased applications for ENMs in the outdoor urban environment. Our objective for this paper is therefore to review, assess, and provide new information in this emerging field. We provide an overview of nanomaterials (NMs, encompassing both ENMs and incidental nanomaterials, INMs) that are likely to be released in the urban environment from outdoor sources by discussing 1) the applications of ENMs that may lead to release of ENMs in urban areas, 2) the recently published data on the release of ENMs from novel nano-enabled applications in the outdoor urban environment, 3) the available literature on the occurrence of INMs in the atmosphere and within/on dust particles, and 4) the potential pathways and fate of NMs in the outdoor urban environment. This review is then followed by three case studies demonstrating the importance of NMs in the outdoor urban environment. The first and second case studies illustrate the occurrence of NMs in urban dust and stormwater ponds, respectively, whereas the third case study discusses the lessons learned from the release of NMs (e.g. Pt, ph and Rh) from automotive vehicle catalytic convertors. This article ends with a discussion of the research priorities needed to advance this emerging field of "outdoor urban nanomaterials" and to assess the potential risks of NMs in the context of urban environments.

Microchemical analysis of selenium in otoliths of two West Virginia fishes captured near mountaintop removal coal mining operations

Otoliths, calcified inner ear structures, were collected from creek chubs (Semotilus atromaculatus) and green sunfish (Lepomis cyanellus) living in mountaintop mining-impacted and reference streams and analyzed for selenium (Se) content using laser ablation-inductively coupled mass spectrometry. Significant differences in otolith Se were found between the 2 fish species. Results from the present study suggest that a retrospective reconstruction of Se concentrations in muscle can be derived from Se concentrations in otoliths in creek chub but not green sunfish, exemplifying the importance of species differences when determining partitioning of Se among specific tissues. Green sunfish otoliths from all sites contained background (<1 μg/g) or low (1-4 μg/g) average concentrations of whole-otolith Se. In contrast, creek chub otoliths from the historically mined site contained much higher (≥5 μg/g) concentrations of Se than for the same species in the unmined site or for the green sunfish. These data suggest that body burdens of Se in fish can vary considerably over time and that both the timing of sampling and species choice could heavily influence Se assessments.

Still childless at the age of 28 to 40 years: a cross-sectional study of Swedish women's and men's reproductive intentions

BACKGROUND

Delayed childbearing is associated with adverse reproductive outcomes. Our aim was to investigate Swedish women's and men's childbearing intentions at the age of 28, 32, 36 and 40 years, in terms of: (1) time point for a first child, (2) number of children, and (3) reasons for not yet having children.

METHODS

Cross-sectional data from the Swedish Young Adult Panel Study, including 365 childless women and 356 childless men aged 28, 32, 36 and 40 years who responded to a questionnaire in 2009. Descriptive and multivariate logistic regression analyses were conducted.

RESULTS

Most 28- and 32-year-olds intended to have children, but only 32% of women and 37% of men aged 36/40 years (merged), many of whom still postponed childbearing. Reasons for remaining childless differed by age. Most prominent in the 36/40-year-olds were: lack of a partner (women 60%, men 59%), no desire for children (women 44%, men 44%), not mature enough (women 29%, men 35%), and wanting to do other things before starting a family (women 26%, men 33%). The 36/40-year-olds had the highest odds for infertility problems (OR 3.8; CI 95% 1.8-7.9) and lacking a suitable partner (OR 1.8 CI 95% 1.1-3.0), and lower odds for reasons related to work and financial situation.

CONCLUSIONS

Many childless 36- and 40-year-olds intended to have children but seemed to overestimate their fecundity. The most prominent reasons for being childless were: not having wanted children up to now, lack of a partner, infertility problems, and prioritising an independent life.

Estimating above-ground carbon biomass in a newly restored coastal plain wetland using remote sensing

Developing accurate but inexpensive methods for estimating above-ground carbon biomass is an important technical challenge that must be overcome before a carbon offset market can be successfully implemented in the United States. Previous studies have shown that LiDAR (light detection and ranging) is well-suited for modeling above-ground biomass in mature forests; however, there has been little previous research on the ability of LiDAR to model above-ground biomass in areas with young, aggrading vegetation. This study compared the abilities of discrete-return LiDAR and high resolution optical imagery to model above-ground carbon biomass at a young restored forested wetland site in eastern North Carolina. We found that the optical imagery model explained more of the observed variation in carbon biomass than the LiDAR model (adj-R(2) values of 0.34 and 0.18 respectively; root mean squared errors of 0.14 Mg C/ha and 0.17 Mg C/ha respectively). Optical imagery was also better able to predict high and low biomass extremes than the LiDAR model. Combining both the optical and LiDAR improved upon the optical model but only marginally (adj-R(2) of 0.37). These results suggest that the ability of discrete-return LiDAR to model above-ground biomass may be rather limited in areas with young, small trees and that high spatial resolution optical imagery may be the better tool in such areas.

Lymphocyte reconstitution following allogeneic hematopoietic stem cell transplantation: a retrospective study including 148 patients

Here we investigated the influence of parameters known before hematopoietic stem cell transplantation (HSCT) as well as the relevance of graft-versus-host disease (GvHD) and cytomegalovirus (CMV) reactivation on post transplant lymphocyte reconstitution in 148 patients treated in our institution between 1996 and 2003. Median patient age was 42 (19-68) years, HSCT followed standard high dose (n=91) or reduced-intensity conditioning regimens (n=57) with bone marrow (BM, n=67) or peripheral blood stem cells (PBSC, n=81) from related (n=71) or unrelated (n=77) donors. In the first months, we observed a partially faster reconstitution of CD3+4+, CD3+8+ and CD4+45RA+ T cells in patients following peripheral blood stem cell transplantation when compared to bone marrow transplantation. Prolonged CD3+4+ and CD4+45RA+ lymphopenia was noted after unrelated donor HSCT and GvHD prophylaxis containing anti-T-lymphocyte globulin. Lymphocyte subset counts in patients older than the median age were comparable to those in patients transplanted at a younger age and not influenced by the conditioning regimen. CD3+8+ T cell reconstitution was strongly correlated with CMV reactivation, but not significantly affected by CMV serostatus before HSCT. Incidence or extent of GvHD did not significantly influence lymphocyte reconstitution. Therefore, the source of graft is the most predictive parameter in early lymphocyte reconstitution, but the differences in lymphocyte recovery completely resolved within the first year after HSCT.

Inequalities in under-five mortality in Mozambique: differentials by region of residence and ethnic affiliation of the mother

OBJECTIVE

To explore regional and ethnic differentials in under-five mortality in Mozambique in relation to other determinants.

DESIGN

Retrospective follow-up study.

SETTING

Mozambique.

RESULTS

Compared to children of Xitsonga mother's, children of Emakua and Cisena mother's had a mortality risk of 1.47 (CI = 1.06-1.90) and 1.21 (CI = 1.00-1.62) respectively. The excess mortality risks were partly explained by demographic, household environment, socioeconomic factors including region of residence.

CONCLUSION

Ethnic affiliation of the mother (measured by the first language the mother spoke) was statistically associated with under-five mortality in Mozambique. Children of mothers of Emakua and Cisena ethnic affiliations and living in the North and Central regions had the worst survival chances. The relation between mother's ethnicity and under-five mortality was largely explained by demographic, socioeconomic and environmental factors.

Contribution of household environment factors to urban childhood mortality in Mozambique

OBJECTIVES

Household environment factors are known to be associated with child mortality in urban and rural areas of many developing countries. In Mozambique, no study to date has addressed this relationship. This study is aimed to access the contribution of household environment factors to urban childhood mortality in Mozambique.

DESIGN

Retrospective follow-up study.

SETTING

Urban Mozambique.

SUBJECTS

One thousand and forty eight children born in urban areas of Monzambique within five years of the 1997 Demographic and Health Survey.

METHODS

Cox regression analysis was performed on a sample of 1048 children born in urban areas of Mozambique within five years of the 1997 Demographic and Health Survey.

RESULTS

Children of mother's who lived in households with no toilet facility or with well as a source of drinking water had a high risk of dying compared to children who lived in households with flush toilet and piped water.

CONCLUSION

Type of toilet facility and source of drinking water play an important role in the risk of childhood mortality in urban areas of Mozambique and the relationship seems to be mediated partly by demographic and socioeconomic factors.

Biotransformation of insulin glargine after subcutaneous injection in healthy subjects

OBJECTIVE

It is important to establish pharmacokinetic or pharmacodynamic differences between novel insulin analogues and human insulin. This study examined the primary metabolic degradation products of insulin glargine (LANTUS) in humans.

DESIGN

In this single dose, open-label study, insulin glargine was administered subcutaneously at a dose of 0.6 IU/kg; placebo was administered to one control subject.

PATIENTS

Four healthy male subjects, plus one control subject, aged 18-50 years were enrolled in this study.

MEASUREMENTS

Following insulin glargine administration, blood glucose levels were clamped at the subjects' fasting concentration for 6 h and the amount of 20% glucose infused to maintain this baseline concentration was recorded. Metabolite profiling was performed in plasma and injection site tissue using HPLC and radioimmunoassay (RIA). Pharmacokinetics were evaluated by RIA of serum and plasma immunoreactive insulin levels. The primary pharmacodynamic measure was the glucose infusion rate (GIR). Safety was evaluated by measuring blood glucose concentrations during the clamp and adverse events were observed by the investigator or reported by the subject.

RESULTS

Metabolic profiling revealed a clear pattern: insulin glargine is metabolised by sequential cleavage at the carboxy terminus of the B chain, to yield products M1 and M2, which are both structurally similar to human insulin. These degradation products are present both at the injection site and in plasma.

CONCLUSION

Thus, during treatment with a subcutaneous injection of insulin glargine, metabolic degradation is likely to be initiated at the injection site and continued within the circulatory system.

Synthesis and properties of the tetrakis(trifluoromethyl)borate anion, [b(CF3)4]-: structure determination of Cs[B(CF3)4] by single-crystal X-ray diffraction

Salts of the tetrakis(trifluoromethyl)borate anion, M[B(CF3)4], M=Li, K, Cs, Ag, have been prepared by two different routes for the first time. The colorless compounds are thermally stable up to 425 C (Cs salt) and soluble in anhydrous HF, water, and most organic solvents. Single crystals of Cs[B(CF3)4] were grown from diethyl ether by diffusion of CH2Cl2 vapor into the solution. The molecular structure was obtained by single-crystal X-ray diffraction. Crystal data: rhombohedral space group R3m (no. 160); a =7.883(1), c=13.847(4) A: V=748.2 A3; Z=3; T=150K; R1=0.0118, wR2=0.0290. The internal bond parameters of the [B(CF3)4] ion were compared to those of the C(CF3)4 molecule. Due to a disorder of the anions in the cesium salt, it is not possible to distinguish between T and Td symmetry by X-ray diffraction experiments alone. However, a comprehensive IR and Raman study demonstrated that in the potassium and cesium salt as well as in aqueous solution, the anion exhibits T symmetry with all CF3 groups rotated off the staggered position required for Td symmetry. The vibrational study is supported by DFT calculations, which provide, in addition to the equilibrium structure and vibrational wavenumbers, estimates of IR and Raman band intensities. The anion is resistant against strong oxidizing (e.g., F2) as well as reducing agents (e.g., Na) and is not affected by nucleophiles like C2H5O or electrophiles such as H3O+. It is very weakly coordinating, as demonstrated by the low-equilibrium CO pressure over the [Ag(CO)x][B(CF3)4] (x=1, 2) co-adducts and the formation of [Ag(CO)x][B(CF3)4] (x=3,4) at higher CO pressure. The 11B, 13C, and 19F NMR data as well as the structural parameters of the anion are compared with those for other borates containing F, CN, and CF3 ligands.

Social differentials in the decline of child mortality in nineteenth century Stockholm

BACKGROUND

Mortality had declined dramatically by the end of the nineteenth century and the early twentieth century. Little is known about the development of social differentials in infant and child mortality in Stockholm at the turn of the century. This study investigates social differentials in child mortality during the years 1885, 1891 and 1910 in one parish in Stockholm.

METHODS

Individual entries from computerised records originally collected for civil registration purposes in Stockholm for 1878-1925 (the Roteman Archives) were analysed with respect to social class of the head of household and marital status of the mother for 36,718 children aged 0-14 years. Age- and cause-specific mortality rates were calculated for each year of study. Cox' regression analysis was used to analyse the mortality risk (relative rates (RRs) of mortality) by socioeconomic group and by marital status of the mother.

RESULTS

Child mortality rates were nearly halved between 1885 and 1910. Socioeconomic differentials in mortality between the four social classes emerged from 1891 as the overall mortality declined. The decline was sharpest in the upper and middle social classes. Children born out of wedlock had higher mortality rates than children of married mothers in all 3 years studied.

CONCLUSION

The social differentials in child mortality risk were substantial and the gradient emerged sharper from 1891 to 1910. The results are in line with studies from England and Wales, Germany and the USA for the same time period. The differentials mostly increased because of a greater decline in mortality among higher socioeconomic groups.

The Tetrakis(carbonyl)dioxoosmium(VI) Cation: trans-

The first carbonyl compound of a transition metal in the oxidation state +6 was obtained by reductive carbonylation of OsO(4) in SbF(5). Through the use of extensive IR, NMR, and UV/Vis spectroscopic studies as well as density functional calculations it was determined that the trans-[OsO(2)(CO)(4)](2+) cation adopts the octahedral structure shown in the picture with trans oxygen atoms.

Use of a historical register in social epidemiology: child mortality in Stockholm at the turn of the 19th century

This study describes the age- and cause-specific levels and social determinants of high child mortality in Stockholm around the turn of the century. The study is based on computerized individual level sociodemographic information and the death certificates of children aged 0-15 years residing in Maria parish in Stockholm during the years 1885, 1891 and 1910 (n = 36,718) from a historical register (the Roteman archives). The usefulness of such data for further studies in social epidemiology is discussed. Age-specific rates and major causes of death compared well with other studies. Low social class and being born out of wedlock increased the overall risk of death in early childhood. Data appear valid and may be useful in social epidemiology. Further analyses of data from the Roteman archives may contribute to the understanding of causes behind high levels of cause- specific child mortality and trends in mortality in relation to societal change.

Spontaneous perforation of the ureter: a rare complication of urolithiasis

The spontaneous rupture of the ureter is a rare condition. A case of a girl is reported with a spontaneous perforation caused by ureteral and renal calculi. The concomitant urinoma was drained and the ureter splinted with a double-J catheter. The calculi were destroyed by extracorporal piezoelectric lithotripsy without anesthesia.