Hydrogen-atom transfer in open-shell organometallic chemistry: the reactivity of Rh(II)(cod) and Ir(II)(cod) radicals.

A series of new metalloradical rhodium and iridium complexes [M(II)(cod)(N-ligand)](2+) in the uncommon oxidation state +II were synthesized by one-electron oxidation of their [M(I)(cod)(N-ligand)](+) precursors (M=Rh, Ir; cod=(Z,Z)-1,5-cyclooctadiene; and N-ligand is a podal bis(pyridyl)amine ligand: N,N-bis(2-pyridylmethyl)amine (dpa), N-(2-pyridylmethyl)-N-(6-methyl-2-pyridylmethyl)amine (pla), or N-benzyl-N,N-bis(6-methyl-2-pyridylmethyl)amine (Bn-dla). EPR spectroscopy, X-ray diffraction, and DFT calculations reveal that each of these [M(II)(cod)(N-ligand)](2+) species adopts a square-pyramidal geometry with the two cod double bonds and the two pyridine fragments in the basal plane and the N(amine) donor at the apical position. The unpaired electron of these species mainly resides at the metal center, but the apical N(amine) donor also carries a considerable fraction of the total spin density (15-18 %).

Interruption of Wnt signaling attenuates the onset of pressure overload-induced cardiac hypertrophy.

The hypertrophic response of the heart has been recognized recently as the net result of activation of prohypertrophic and antihypertrophic pathways. Here we report the involvement of the Wnt/Frizzled pathway in the onset of cardiac hypertrophy development. Stimulation of the Wnt/Frizzled pathway activates the disheveled (Dvl) protein.

PCB congener profiles in nestling tree swallows and their insect prey.

Tree swallows (Tachycineta bicolor) are widely used as indicators of local polychlorinated biphenyl (PCB) contamination in North America. Although determining total PCB residues in tissues is useful in environmental monitoring, analysis of PCB congener profiles may reveal sources of contamination and thus prove to be a more refined tool to track contaminants through the food web. To show how differences in PCB congener patterns in birds can be linked to the PCB patterns in their prey, we evaluated PCB congeners in tissues of tree swallow nestlings and their insect prey using principal component analysis and Euclidean similarities.

Cognitive mechanisms of social anxiety reduction: an examination of specificity and temporality.

Cognitive theories posit that exposure-based treatments exert their effect on social anxiety by modifying judgmental biases. The present study provides a conservative test of the relative roles of changes in judgmental biases in governing social anxiety reduction and addresses several limitations of previous research. Longitudinal, within-subjects analysis of data from 53 adults with a Diagnostic and Statistical Manual of Mental Disorders (4th ed.

Transient AT1 receptor-inhibition in prehypertensive spontaneously hypertensive rats results in maintained cardiac protection until advanced age.

Objective: In young spontaneously hypertensive rats (SHR), transient angiotensin II type 1 receptor (AT1R) blockade decreases blood pressure for a prolonged period. We tested the hypothesis that transient AT1R blockade in SHR leads to cardiac protection until advanced age.

Method: Wistar-Kyoto rats, SHR and transiently losartan-treated SHR (SHR-Los) (20 mg/kg per day; weeks 4-8 of age) were followed up until week 72 (n=9 each group), including repeated echocardiography, radiotelemetric investigations and 24-h urine collection.

Influence of a TiCl4 post-treatment on nanocrystalline TiO2 films in dye-sensitized solar cells.

In this study, the influence of the TiCl(4) post-treatment on nanocrystalline TiO(2) films as electrodes in dye-sensitized solar cells is investigated and compared to nontreated films. As a result of this post-treatment cell efficiencies are improved, due to higher photocurrents. On a microscopic scale TiO(2) particle growth on the order of 1 nm is observed.

Rhodium-mediated stereoselective polymerization of "carbenes".

Unprecedented rhodium-catalyzed stereoselective polymerization of "carbenes" from ethyl diazoacetate (EDA) to give high molecular mass poly(ethyl 2-ylidene-acetate) is described. The mononuclear, neutral [(N,O-ligand)M(I)(cod)] (M = Rh, Ir) catalytic precursors for this reaction are characterized by (among others) single-crystal X-ray diffraction. These species mediate formation of a new type of polymers from EDA: carbon-chain polymers functionalized with a polar substituent at each carbon of the polymer backbone.

Brood patches of American kestrels altered by experimental exposure to PCBs.

Captive breeding (n = 25 pairs) and nonbreeding (n = 25) American kestrels were exposed to a mixture of polychlorinated biphenyls (PCBs) (Aroclor 1248:1254:1260) through their diet of day-old cockerels. Kestrels ingested approximately 7 mg/kg body weight each day of PCBs, and this dosage resulted in environmentally relevant total PCB residues in eggs (geometric mean of 34.1 microg/g).

Examination of the decline in fear and disgust during exposure to threat-relevant stimuli in blood-injection-injury phobia.

In the present study, participants (N=22) displaying marked fear of blood-injection-injury (BII) stimuli were provided 30 min of in vivo exposure to threat-relevant stimuli, during which time their fear and disgust levels were repeatedly assessed. Growth curve analyses were then conducted to examine the decay slopes in both fear and disgust and their relationship. Results indicated that exposure led to significant declines in fear and disgust across trials.

Proteus mirabilis spondylodiscitis complicating a urinary tract infection.

Infectious spondylodiscitis results from local or haematogenous infection by microorganisms of intervertebral disc spaces, vertebral bodies and surrounding structures. Haematogenous invasion may follow urosepsis. We report on a case of septic spondylodiscitis following urosepsis with Proteus mirabilis, a frequently isolated microorganism in urinary tract infections but rarely in spondylodiscitis.

Kidney transplantation without prior dialysis in children: the Eurotransplant experience.

Kidney transplantation without prior dialysis may prevent dialysis-associated morbidity. We analyzed the outcome of 1113 first kidney transplants in children performed between 1990 and 2000 in the Eurotransplant community. Enlistment for a deceased donor kidney before start of dialysis (127/895, 14%) made dialysis redundant in 55% of cases.

Disrupted bone metabolism in contaminant-exposed white storks (Ciconia ciconia) in southwestern Spain.

In 1998, the Aznalcóllar mine tailings dyke in southwestern Spain broke, flooding the Agrio-Guadiamar river system with acid tailings up to the borders of one of the largest breeding colonies of white storks in the western Palearctic, Dehesa de Abajo. Over the following years, a high proportion of nestlings developed leg defects not seen before the spill, prompting this study. Nestlings with deformed legs had significantly lower plasma phosphorous (P) and higher Ca:P ratios than non-deformed cohorts in the first two years, but in the third year, when more, younger birds were studied, plasma P ranged from much higher to much lower in the affected colony compared with reference birds.

Dysfunction of lower urinary tract in renal transplant children with nephrologic disease.

Objectives: To investigate the relationship between dysfunction of the lower urinary tract after renal transplantation and renal transplant function in children with an underlying nephrologic disease.

Methods: The research group consisted of 21 renal transplant children (12 girls and 9 boys, mean age 13.5 years, range 6 to 18) with an underlying nephrologic disease.

Biologically relevant effects of mRNA amplification on gene expression profiles.

Background: Gene expression microarray technology permits the analysis of global gene expression profiles. The amount of sample needed limits the use of small excision biopsies and/or needle biopsies from human or animal tissues. Linear amplification techniques have been developed to increase the amount of sample derived cDNA.

Augmentation of exposure therapy with D-cycloserine for social anxiety disorder.

Context: Social anxiety disorder (SAD) is common and debilitating. Although exposure therapy is one of the most effective forms of psychotherapy for this disorder, many patients remain symptomatic. Fear reduction in exposure therapy is similar to extinction learning, and early clinical data with specific phobias suggest that the treatment effects of exposure therapy for SAD may be enhanced with d-cycloserine, an agonist at the glutamatergic N-methyl-d-aspartate receptor.

The efficacy of videotape feedback for enhancing the effects of exposure-based treatment for social anxiety disorder: a controlled investigation.

Correcting patients' faulty beliefs concerning social evaluative threats is the hallmark of cognitive-behavioral treatment of social anxiety disorder. The current study examined the efficacy of two videotape feedback procedures as adjuncts to exposure-based treatment. Participants suffering from social phobia (N=77) were randomly assigned to one of four conditions: (a) credible placebo treatment (PLA); (b) exposure + no feedback (EXP); (c) exposure + videotape feedback of performance (PER); or (d) exposure + videotape feedback of audience responses (AUD).

Spatial, temporal, and dietary determinants of organic contaminants in nestling tree swallows in Point Pelee National Park, Ontario, Canada.

Point Pelee National Park of Canada in southwestern Ontario, an important migratory route and vital breeding area for many birds, has localized areas of organochlorine (OC) pesticide contamination from agricultural production during the 1950s and 1960s. During 2001 and 2002, we investigated movement of persistent contaminants through the food web with the insectivorous tree swallow (Tachycineta bicolor) as a sentinel. The a priori site classifications, contaminated or reference, were based on soil residues of dichlorodiphenyltrichloroethane (DDT) and its breakdown products (sigmaDDT), dieldrin, and other OC pesticides.

Emotional vulnerability as a function of physical activity among individuals with panic disorder.

This investigation evaluated the association between physical inactivity and emotional vulnerability in panic disorder. Participants were 39 adults (69% females) with a primary diagnosis of panic disorder (with or without agoraphobia), recruited through the community. Consistent with prediction, current physical inactivity was significantly associated with greater levels of anxiety sensitivity and severity of panic disorder.

Waiting for a thoracic transplant in Eurotransplant.

The prospects of patients on the thoracic waiting list are governed by the chance of receiving an organ in time and by the outcome of the transplantation. The former probability is determined by a triad of disease severity, resource size and allocation rules. The aim of this study was to provide an objective description of the distributional effects of the thoracic allocation system in Eurotransplant.

Effects of oil sands tailings compounds and harsh weather on mortality rates, growth and detoxification efforts in nestling tree swallows (Tachycineta bicolor).

Oil sands mining companies in Alberta, Canada, are evaluating the feasibility of using wetlands to detoxify oil sands process material (OSPM) as a reclamation strategy. Reproductive success, nestling growth, survival and ethoxyresorufin-o-deethylase (EROD) activity were measured in tree swallows (Tachycineta bicolor) on experimental wetlands. In 2003, harsh weather triggered a widespread nestling die-off.

Organochlorine contamination and physiological responses in nestling tree swallows in Point Pelee National Park, Canada.

Point Pelee National Park in southwestern Ontario, Canada--a major migratory route and vital breeding area for many birds--has localized areas of organochlorine (OC) contamination from the 1950s and 1960s. During 2002, we investigated the effect of tissue OC contaminant levels on the physiology and growth of nestling tree swallows (Tachycineta bicolor). Polychlorinated biphenyl (PCB) contamination in the nestlings positively correlated with hepatic ethoxy-, benzyloxy-, and pentoxyresorufin-o-dealkylase enzyme activities and liver size.

Behavioral variation and its consequences during incubation for American kestrels exposed to polychlorinated biphenyls.

We investigated whether polychlorinated biphenyl (PCB) exposure in American kestrels (Falco sparverius) influenced incubation behavior and whether altered behavior could lead to poor reproductive success. Captive kestrels were fed a mixture of PCBs (Aroclors 1248:1254:1260) at an approximate daily dose of 7 mg/kg body weight, 1 month prior to pairing and throughout incubation. Behaviors of 23 control and 23 PCB-exposed pairs were monitored throughout incubation using an electronic balance in the nest box.

Substitution of a conserved alanine in the domain IIIS4-S5 linker of the cardiac sodium channel causes long QT syndrome.

Objective: Congenital long QT syndrome type 3 (LQT3) is an inherited cardiac arrhythmia disorder due to mutations in the cardiac sodium channel gene, SCN5A. Although most LQT3 mutations cause a persistent sodium current, increasing diversity in the disease mechanism is shown. Here we present the electrophysiological properties of the A1330T sodium channel mutation (DIIIS4-S5 linker).

Skeletal pathology in white storks (Ciconia ciconia) associated with heavy metal contamination in southwestern Spain.

In 1998, a mine tailings dyke in southwestern Spain broke, flooding the Agrio-Guadiamar river system with acid tailings up to the borders of one of the largest breeding colonies of white storks in the western Palearctic, Dehesa de Abajo. Over the following years, a high proportion of nestlings developed leg defects, prompting this study. Ten fledglings with leg deformities from the spill area were compared with 11 normal storks of the same year class from another region far from the spill.

Intragenerational mobility and mortality in Oslo: social selection versus social causation.

We investigate the relative importance of the selection and causation hypotheses of social inequalities in mortality, and estimate upper and lower bounds for the gender-specific mobility effects. For all inhabitants of Oslo aged 50-69 years in 1990, we knew their social class in 1960 and 1980 and whether they died between 1990 and 1994. Analysing these data with diagonal reference models, we found those moving upwards in the social hierarchy to have lower mortality rates than their class of origin but higher mortality rates than their class of destination.