Historical changes (1905-2005) in external phosphorus loads to Loch Leven, Scotland, UK

This article reviews historical changes in the total phosphorus (TP) inputs to Loch Leven, Scotland, UK. Data derived from palaeolimnological records suggest that inputs in the early 1900s were about 6 t TP year-1 (0.45 g TP m-2 year-1). By 1985, this had risen to about 20 t TP year-1 (1.5 g TP m-2 year-1) due to increases in runoff from agricultural land and discharges from point sources. By the late 1970s, increased TP inputs were causing serious degradation of lake water quality. Most noticeably, there had been an increase in cyanobacterial blooms. A catchment management plan was implemented in the early 1990s. This resulted in a 60% reduction in the annual TP input between 1985 (20 t TP year-1/1.5 g TP m-2 year-1) and 1995 (8 t TP year-1/0.6 g TP m-2 year-1). The main reduction was associated with better control of point source discharges, but attempts were also made to reduce inputs from diffuse sources. The reduction in external TP loading to the lake led to a marked decline in TP retention by the lake each year

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Department of ChemistryRu-based sensitizers (N719, N3, black dye, etc.) have been developed continuously and reached an efficiency of ~11.7% under AM 1.5G irradiation (1000 W/m2). However, these Ru-based sensitizers are not adequate to commercialization because of a stability issue and a need of thick TiO2 film for a high power conversion efficiency (PCE). Therefore, we designed and synthesized total four organic sensitizers by varying functional groups ondonor moieties to understand the structure-property relationship of the solar cell devices, ranging from the stability to the efficiency in thin TiO2 film system. First, all the sensitizers were composed of dithieno[3,2-b:2',3'-d]thiophene (DTT) as a ??-conjugated bridge for a strong stability against external environment. Second, three sensitizers (TP-1, TP-2 and TP-3) containedthe proton (control group), the methoxygroup, and the carbazole group on donor moieties respectively. TP-2 with methoxy groups achieved thehighest PCE of 8.70%and exhibited stronger thermal and light stability than TP-1 and TP-3which can be attributed to the good electron donating ability. However, TP-2 showed the lowest water stability.On the other hands, TP-3 with carbazole groups showed a relatively low PCE of 7.40%.TP-3 alsoexhibited weak thermal and light stabilitybecause 3,6-position of carbazole were easily oxidized by external energy but achieved the highest water stabilitypresumably bythe strong hydrophobicity of carbazole groups. Based on the observation, we postulated protecting role of functional groups on donors (TPA) and themselves was vital to determine the stability.Therefore, TP-4 with a 2-ethylhexyloxy group was designed and synthesized for protecting oxygen on alkoxy group. As a result, TP-4 achieved high stabilitiesin terms of thermal, light and water stability and aPCE as high as 7.80%due to the strong electron donating ability as shown in the methoxy group of TP-2.ope

Trend Analysis of Teenage Pregnancy in Nigeria (1961-2013): How Effective is the Contraceptive Use Campaign

Teenage pregnancy (TP) is a recurrent global and public health problem. It poses both social and health challenges. Considering the massive campaign on the use of modern contraceptives to prevent TP in recent decades, we assessed trends in TP in Nigeria between 1961 and 2013. Pregnancy and contraception history of 70,811 women who were at least 20 years old when the Nigerian DHS was conducted in 1990, 2003, 2008, and 2013 respectively were used for the study, and descriptive statistics, time analysis techniques and multiple logistic regression were used to analyze the data at 5% significance level. The overall prevalence of TP between 1961 and 2013 was 49.5% which fluctuated insignificantly during the studied period. The TP prevalence among women who entered adulthood in 1961 was 39.2%; it peaked in 1978 at 58.9% before its unsteady decline to 39.6% in 2012, and then rose sharply to 55.6% in 2013. We predicted TP prevalence as 49.0%, 49.9% and 51.0% in 2014, 2015 and 2016 respectively. The odds of TP were over 4 times higher in the North East and 5 times higher in the North West than in the South West. Teenagers with no education had higher odds of TP and it was higher among teenagers from the poorest households (OR=5.64, 95% CI: 5.36-5.94). Rather than reducing with the worldwide acknowledged increase in contraceptive campaigns, TP increased over the years studied. As far as TP is concerned in Nigeria, the impact of the campaign on MC use is far from being effective. To achieve the objective of fewer TPs, fewer resources should be spent on access to contraception and instead diverted to areas more likely to achieve results such as improvements in educational achievement amongst girls

Spatiotemporal Neurodynamics Underlying Internally and Externally Driven Temporal Prediction: A High Spatial Resolution ERP Study

Temporal prediction (TP) is a flexible and dynamic cognitive ability. Depending on the internal or external nature of information exploited to generate TP, distinct cognitive and brain mechanisms are engaged with the same final goal of reducing uncertainty about the future. In this study, we investigated the specific brain mechanisms involved in internally and externally driven TP. To this end, we employed an experimental paradigm purposely designed to elicit and compare externally and internally driven TP and a combined approach based on the application of a distributed source reconstruction modeling on a high spatial resolution electrophysiological data array. Specific spatiotemporal ERP signatures were identified, with significant modulation of contingent negative variation and frontal late sustained positivity in external and internal TP contexts, respectively. These different electrophysiological patterns were supported by the engagement of distinct neural networks, including a left sensorimotor and a prefrontal circuit for externally and internally driven TP, respectively

Selenoxopropadienylidene (CCCSe) as a bridging ligand

The reaction of [W(≡CC≡CSiMe3)(CO)2(Tp*)] (Tp* = hydrotris(3,5-dimethylpyrazol-1-yl)borate) with [nBu4N]F and selenium in the presence of [RuCl(PPh3)2(η-C5H5)] affords a mixture of the tricarbido complex [WRu(μ-CCC)(CO)2(PPh3)2(η-C5H5)(Tp*)] and the selenoxopropadienylidene (C3Se) complex [WRu(μ-CCCSe)(CO)2(PPh3)2(η-C5H5)(Tp*)], both of which were structurally characterized. The formation of the bimetallic C3Se complex is consistent with the intermediacy of the salt [nBu4N] [W(≡CC≡CSe)(CO)2(Tp*)], which could be observed spectroscopically and computationally interrogated, but not yet isolated.This work was supported by the Australian Research Council (DP130102598 and DP110101611)