Binding of harvested bacterial exopolymers to the surface of calcite

Biologically produced exopolysaccharides (EPS) affect calcite dissolution and precipitation. In this study, natural alkaliphilic microbial isolates were collected from biofilms on historic limestone. The isolates were screened for their ability to produce significant quantities of EPS in cultures. The most productive isolates were identified by 16S rRNA sequence analysis as a close relative of Bacillus cereus. EPS with different chemical structures were harvested from the isolates. Isothermal titration calorimetry (ITC) was used to quantify the thermodynamics of binding by the harvested EPS to calcite. The binding was described by a Langmuir adsorption isotherm. Characterization of the EPS showed that binding strength to calcite depended on the chemical nature of the polymer.     

A Sharp Interface Model of Intermediate-Phase Growth Under the Influence of Electromigration

A sharp interface model has been developed to model intermediate-phase growth under the influence of electromigration in a binary system. Simulation results show that the phase growth rate depends on both the magnitude and the direction of the applied current. With the current density fixed, at early times, there is a parabolic growth behavior for the intermediate phase, while at longer times, there is a linear phase growth behavior when the electron flow aids diffusion of atoms; however, a limiting thickness is found when the electron flow hinders diffusion. Qualitative analysis shows that the longer time behavior also holds in a binary system with multiple intermediate phases present.     

Utility of the RT3 triaxial accelerometer in free living: An investigation of adherence and data loss

There is strong evidence for the protective effects of physical activity on chronic health problems. Activity monitors can objectively measure free living occupational and leisure time physical activity. Utility is an important consideration when determining the most appropriate monitor for specific populations and environments. Hours of activity data collected, the reasons for activity hours not being recorded, and how these two factors might change over time when using an activity monitor in free living are rarely reported. This study investigated user perceptions, adherence to minimal wear time and loss of data when using the RT3 activity monitor in 21 healthy adults, in a variety of occupations, over three (7 day) repeated weeks of measurement in free living. An activity diary verified each day of monitoring and a utility questionnaire explored participant perceptions on the usability of the RT3. The RT3 was worn for an average of 14 h daily with 90% of participants having complete data sets. In total 6535.8 and 6092.5 h of activity data were collected from the activity diary and the RT3 respectively. An estimated 443.3 h (6.7%) of activity data were not recorded by the RT3. Data loss was primarily due to battery malfunction (45.2%). Non-adherence to wear time accounted for 169.5 h (38.2%) of data loss, of which 14 h were due to occupational factors. The RT3 demonstrates good utility for free living activity measurement, however, technical issues and strategies to manage participant adherence require consideration with longitudinal and repeated measures studies.     

Northern Red Oak Glued-Laminated Timber Bridge

A 5-year program to monitor the performance of a red oak longitudinal girder, transverse deck glued-laminated (glulam) highway bridge is presented. The bridge design details, including preservative treatment results, are described. The live loading results indicate that the predicted and observed live load beam deflections agree to within 7% when the stiffness of the individual beam laminations is used as a predictor and a 10% increase in beam stiffness due to composite action between the deck panel and logitudinal girders is incorporated into the design. The dimensional stability of the deck panels over 3 years has been monitored and analyzed. Significant reflexive cracking of the asphaltic wearing surface has been observed at the interface between each red oak deck panel. This has been attributed to the gap provided between each panel during construction, to the placement of the waterproof membrane directly over the creosote-treated deck panels, and to improper mating of the deck panels to the beams during installation of the lag bolts. Long-term (3-year) dead load deflection measurements indicate that after approximately 1 year, dead load deflections remain nearly constant for the interior beams. Elevations of the lower surface of the two exterior beams fluctuate considerably and vary seasonally. There is no evidence of delamination of the girders or deck panels after 4 years. However, there is some evidence of delamination of the curbs and the tops of rail posts.     

Responses of immature pullets to repeated cycles of gradual increases and abrupt decreases in photoperiod

1. Growing pullets were reared on constant 8, 11 or 14 h photoperiods or given 12 daily increments of 30 min followed by an abrupt 6 h decrease in photoperiod in 14 d cycles from 2 d of age to sexual maturity. 2. Birds on the experimental lighting programme matured earlier than constant 8-h controls, later than 11-h controls but at the same age and body weight as constant 14-h controls. 3. Weight of the first egg was correlated with age at first egg. 4. It is assumed that potential advances in maturity for the experimental birds from the 30 min increments in photoperiod were cancelled by the retarding influences of 6 h decreases in photoperiod, resulting in their maturity being similar to that of birds reared on a constant daylength equal to the longest photoperiod reached during the cycle.     

以全球角度创造未来的景观设计学

1.关于美国景观设计师协会(ASLA) 100多年以前,景观设计学专业协会是基于社会管理和司法建立起来的,这两者的紧密结合成为了这个协会的灵魂.协会成员相信我们的世界会有新的活力.我们的专业教育,职业信念,以及良好的时机,所处的时代要求将我们的世界、我们的学科、我们的职业和我们的工作整合起来,构成一个有机体.     

Fluoxetine increases norepinephrine release in rat hypothalamus as measured by tissue levels of MHPG-SO4 and microdialysis in conscious rats

The selective serotonin uptake inhibitor fluoxetine (10 mg/kg i.p.) increased tissue levels of the norepinephrine metabolite 3-methoxy-4-hydroxyphenylethylene glycol sulfate (MHPG-SO4) in rat hypothalamus, indicating an increased release of norepinephrine. Microdialysis studies in conscious rats showed that fluoxetine (10 mg/kg i.p.) increased extracellular concentrations of norepinephrine as well as serotonin in the hypothalamus. In contrast, desipramine (10 mg/kg i.p.) increased extracellular concentration of norepinephrine but not serotonin in the hypothalamus. Consistent with its mechanism of being a selective serotonin uptake inhibitor, local perfusion of fluoxetine (10 microM) caused a 7-fold increase in hypothalamic extracellular serotonin and a small non-significant increase in extracellular norepinephrine. The subsequent systemic injection of fluoxetine (10 mg/kg s.c.) after local perfusion caused a 3-fold increase in extracellular norepinephrine, indicating that fluoxetine's action leading to an increase in extracellular norepinephrine was not occurring in the terminal areas of the hypothalamus but elsewhere in the brain, possibly cell bodies in the locus coeruleus.