Women's Voices and Experiences of the Hill-Thomas Hearings

As activist research, this study of women's experiences of the Hill-Thomas hearings was conducted within three weeks of the Senate Judiciary Committee hearings on Anita Hill's charges of sexual harassment by Supreme Court nominee Clarence Thomas. Unlike polls at the time, interviews of 100 Detroit-area women (65 percent white, 35 percent African American) revealed a msyority of strong support for Hill, a default category of support for Thomas, age rather than race as predictor of strong support for Hill or Thomas, and responses of anger and pain from women across the board. The study brings out strengths and challenges of activist research.     

10-Undecanhydroxamic acid, a hydroxamate derivative of the undecanoic acid, has strong antimicrobial activity through a mechanism that limits iron availability

Undecanoic acid (UDA) is a fatty acid with significant antimycotic activity. In this work we have synthesized 10-undecanhydroxamic acid, a hydroxamate derivative of the UDA, and tested its antimicrobial activity on different microorganisms. Our results demonstrate that this compound has higher efficacy than UDA against a variety of fungi and bacteria. Analysis of the intracellular concentration of protein involved in iron transport in Salmonella enterica serovar Typhimurium suggests that its antimicrobial effect actually relies on the ability to chelate iron ions, providing an efficient mechanism to interfere with microbial growth.     

Occurrence and patterns of antibiotic resistance in vertebrates off the Northeastern United States coast

The prevalence of antibiotic-resistant bacteria in the marine environment is a growing concern, but the degree to which marine mammals, seabirds and fish harbor these organisms is not well documented. This project sought to identify the occurrence and patterns of antibiotic resistance in bacteria isolated from vertebrates of coastal waters in the northeastern United States. Four hundred and seventy-two isolates of clinical interest were tested for resistance to a suite of 16 antibiotics. Fifty-eight percent were resistant to at least one antibiotic, while 43% were resistant to multiple antibiotics. A multiple antibiotic resistance index value ≥0.2 was observed in 38% of the resistant pathogens, suggesting exposure of the animals to bacteria from significantly contaminated sites. Groups of antibiotics were identified for which bacterial resistance commonly co-occurred. Antibiotic resistance was more widespread in bacteria isolated from seabirds than marine mammals, and was more widespread in stranded or bycaught marine mammals than live marine mammals. Structuring of resistance patterns based on sample type (live/stranded/bycaught) but not animal group (mammal/bird/fish) was observed. These data indicate that antibiotic resistance is widespread in marine vertebrates, and they may be important reservoirs of antibiotic-resistant bacteria in the marine environment.     

Shrub encroachment can reverse desertification in semi-arid Mediterranean grasslands

The worldwide phenomenon of shrub encroachment in grass-dominated dryland ecosystems is commonly associated with desertification. Studies of the purported desertification effects associated with shrub encroachment are often restricted to relatively few study areas, and document a narrow range of possible impacts upon biota and ecosystem processes. We conducted a study in degraded Mediterranean grasslands dominated by Stipa tenacissima to simultaneously evaluate the effects of shrub encroachment on the structure and composition of multiple biotic community components, and on various indicators of ecosystem function. Shrub encroachment enhanced vascular plant richness, biomass of fungi, actinomycetes and other bacteria, and was linked with greater soil fertility and N mineralization rates. While shrub encroachment may be a widespread phenomenon in drylands, an interpretation that this is an expression of desertification is not universal. Our results suggest that shrub establishment may be an important step in the reversal of desertification processes in the Mediterranean region.     

Effect of Salmonella vaccination of breeder chickens on contamination of broiler chicken carcasses in integrated poultry operations

While measures to control carcass contamination with Salmonella at the processing plant have been implemented with some success, on-farm interventions that reduce Salmonella prevalence in meat birds entering the processing plant have not translated well on a commercial scale. We determined the impact of Salmonella vaccination on commercial poultry operations by monitoring four vaccinated and four nonvaccinated breeder (parental) chicken flocks and comparing Salmonella prevalences in these flocks and their broiler, meat bird progeny. For one poultry company, their young breeders were vaccinated by using a live-attenuated Salmonella enterica serovar Typhimurium vaccine (Megan VAC-1) followed by a killed Salmonella bacterin consisting of S. enterica serovar Berta and S. enterica serovar Kentucky. The other participating poultry company did not vaccinate their breeders or broilers. The analysis revealed that vaccinated hens had a lower prevalence of Salmonella in the ceca (38.3% versus 64.2%; P < 0.001) and the reproductive tracts (14.22% versus 51.7%; P < 0.001). We also observed a lower Salmonella prevalence in broiler chicks (18.1% versus 33.5%; P < 0.001), acquired from vaccinated breeders, when placed at the broiler farms contracted with the poultry company. Broiler chicken farms populated with chicks from vaccinated breeders also tended to have fewer environmental samples containing Salmonella (14.4% versus 30.1%; P < 0.001). There was a lower Salmonella prevalence in broilers entering the processing plants (23.4% versus 33.5%; P < 0.001) for the poultry company that utilized this Salmonella vaccination program for its breeders. Investigation of other company-associated factors did not indicate that the difference between companies could be attributed to measures other than the vaccination program.     

Afamin is synthesized by cerebrovascular endothelial cells and mediates α-tocopherol transport across an in vitro model of the blood–brain barrier

α-Tocopherol (αTocH), a member of the vitamin E family, is essential for normal neurological function. Despite the importance of αTocH transport into the CNS, transfer mechanisms across the blood–brain barrier (BBB) are not entirely clear. We here investigate whether afamin, a known αTocH-binding protein, contributes to αTocH transport across an in vitro model of the BBB consisting of primary porcine brain capillary endothelial cells (BCEC) and basolaterally cultured astrocytoma cells. Exogenously added afamin had no adverse effects on BCEC viability or barrier function and was transported across BCEC Transwell cultures. Furthermore, αTocH transport across polarized BCEC cultures to astrocytoma cells is facilitated by afamin, though to a lesser extent than by high-density lipoprotein-mediated transport, an essential and in vivo operating αTocH import pathway at the cerebrovasculature. We also demonstrate that porcine BCEC endogenously synthesize afamin. In line with these in vitro findings, afamin was detected by immunohistochemistry in porcine, human postmortem, and mouse brain, where prominent staining was observed almost exclusively in the cerebrovasculature. The demonstration of afamin mRNA expression in isolated brain capillaries suggests that afamin might be a new family member of binding/transport proteins contributing to αTocH homeostasis at the BBB in vivo .     

Microphthalmia, parkinsonism, and enhanced nociception in Pitx3 416insG mice

A new spontaneous mouse mutant was characterized by closed eyelids at weaning and without apparent eyes (provisional gene name, eyeless; provisional gene symbol, eyl). The mutation follows a recessive pattern of inheritance and was mapped to the region of chromosome 19 containing Pitx3. Genetic complementation tests using Pitx3 ^ak/+ mice confirmed eyl as a new allele of Pitx3 (Pitx3 ^eyl ). Sequencing of the Pitx3 gene in eyl mutants identified an inserted G after cDNA position 416 (416insG; exon 4). The shifted open reading frame is predicted to result in a hybrid protein still containing the Pitx3 homeobox, but followed by 121 new amino acids. The novel Pitx3 ^eyl/eyl mutants expressed ophthalmological and brain defects similar to Pitx3 ^ak/ak mice: microphthalmia or anophthalmia and loss of dopamine neurons of the substantia nigra. In addition, we observed in the homozygous eyeless mutants increased extramedullary hematopoiesis in the spleen, frequently liver steatosis, and reduced body weight. There were also several behavioral changes in the homozygous mutants, including reduced forelimb grip strength and increased nociception. In addition to these alterations in both sexes, we observed in female Pitx3 ^eyl/eyl mice increased anxiety-related behavior, reduced locomotor activity, reduced object exploration, and increased social contacts; however, we observed decreased anxiety-related behavior and increased arousal in males. Most of these defects identified in the new Pitx3 mutation are observed in Parkinson patients, making the Pitx3 ^eyl mutant a valuable new model. It is the first mouse mutant carrying a point mutation within the coding region of Pitx3.     

SMC6 is an essential gene in mice,but a hypomorphic mutant in the ATPase domain has a mild phenotype with a range of subtle abnormalities

Smc5-6 is a highly conserved protein complex related to cohesin and condensin involved in the structural maintenance of chromosomes. In yeasts the Smc5-6 complex is essential for proliferation and is involved in DNA repair and homologous recombination. siRNA depletion of genes involved in the Smc5-6 complex in cultured mammalian cells results in sensitivity to some DNA damaging agents. In order to gain further insight into its role in mammals we have generated mice mutated in the Smc6 gene. A complete knockout resulted in early embryonic lethality, demonstrating that this gene is essential in mammals. However, mutation of the highly conserved serine-994 to alanine in the ATP hydrolysis motif in the SMC6 C-terminal domain, resulted in mice with a surprisingly mild phenotype. With the neo gene selection marker in the intron following the mutation, resulting in reduced expression of the SMC6 gene, the mice were reduced in size, but fertile and had normal lifespans. When the neo gene was removed, the mice had normal size, but detailed phenotypic analysis revealed minor abnormalities in glucose tolerance, haematopoiesis, nociception and global gene expression patterns. Embryonic fibroblasts derived from the ser994 mutant mice were not sensitive to killing by a range of DNA damaging agents, but they were sensitive to the induction of sister chromatid exchanges induced by ultraviolet light or mitomycin C. They also accumulated more oxidative damage than wild-type cells.     

Separating Movement and Gravity Components in an Acceleration Signal and Implications for the Assessment of Human Daily Physical Activity

Introduction

Human body acceleration is often used as an indicator of daily physical activity in epidemiological research. Raw acceleration signals contain three basic components: movement, gravity, and noise. Separation of these becomes increasingly difficult during rotational movements. We aimed to evaluate five different methods (metrics) of processing acceleration signals on their ability to remove the gravitational component of acceleration during standardised mechanical movements and the implications for human daily physical activity assessment.

Methods

An industrial robot rotated accelerometers in the vertical plane. Radius, frequency, and angular range of motion were systematically varied. Three metrics (Euclidian norm minus one [ENMO], Euclidian norm of the high-pass filtered signals [HFEN], and HFEN plus Euclidean norm of low-pass filtered signals minus 1 g [HFEN₊]) were derived for each experimental condition and compared against the reference acceleration (forward kinematics) of the robot arm. We then compared metrics derived from human acceleration signals from the wrist and hip in 97 adults (22–65 yr), and wrist in 63 women (20–35 yr) in whom daily activity-related energy expenditure (PAEE) was available.

Results

In the robot experiment, HFEN₊ had lowest error during (vertical plane) rotations at an oscillating frequency higher than the filter cut-off frequency while for lower frequencies ENMO performed better. In the human experiments, metrics HFEN and ENMO on hip were most discrepant (within- and between-individual explained variance of 0.90 and 0.46, respectively). ENMO, HFEN and HFEN₊ explained 34%, 30% and 36% of the variance in daily PAEE, respectively, compared to 26% for a metric which did not attempt to remove the gravitational component (metric EN).

Conclusion

In conclusion, none of the metrics as evaluated systematically outperformed all other metrics across a wide range of standardised kinematic conditions. However, choice of metric explains different degrees of variance in daily human physical activity.