Magnetic control assembly reports

Results are summarized of the qualification level vibration tests performed on the magnet control assembly (MCA) for Nimbus and ERTS satellites. The MCA electronics and probe units have demonstrated the capability to survive qualification sinusoidal and random vibration levels. The functional testing indicated normal operation of the units after each axis of vibration. Visual inspection indicated no evidence of degradation. Post vibration acceptance testing verified normal operation of the MCA

The Structure of Urinary Catheter Encrusting Bacterial Biofilms

A major complication of long-term urethral catheterization is catheter blockage by encrustation. We have examined 20 encrusted catheters and in each case crystal formation was associated with the presence of bacterial biofilms on the luminal surfaces. Scanning electron microscopy and X-ray microanalysis indicated the presence of struvite and hydroxyapatite in the biofilms. Urease producing bacteria were colonizing 16 of the catheters. Proteus mirabilis was the commonest species being recovered from ten of the catheters. These results support the hypothesis that catheter encrustation has a similar etiology to that of infection-induced urinary stones and confirm that the important target for any attempt to control catheter encrustations is Pr. mirabilis

Green Manures or Fertilizer Nitrogen for Corn?

How much nitrogen does a legume green-manure crop contribute to the soil? What influence does it have on the yields of the following corn crop? How does this compare with side-dressed applications of fertilizer nitrogen

Biocide Activity against Urinary Catheter Pathogens

Antimicrobial effects of essential oils against bacteria associated with urinary catheter infection was assessed. Tests were performed on 14 different bacterial species cultured either planktonically or as biofilms. Biofilms were found to be up to 8-fold more tolerant of the test agents. Higher antimicrobial tolerance was also evident in tests conducted in artificial urine. Eugenol exhibited higher antimicrobial effects against both planktonic cells and biofilms than did terpinen, tea tree oil, and cineole

Spin Read-out of the Motion of Levitated Electrically Rotated Diamonds

Recent advancements with trapped nano- and micro-particles have enabled the exploration of motional states on unprecedented scales. Rotational degrees of freedom stand out due to their intrinsic non-linearity and their coupling with internal spin degrees of freedom, opening up possibilities for gyroscopy and magnetometry applications and the creation of macroscopic quantum superpositions. However, current techniques for fast and reliable rotation of particles with internal spins face challenges, such as optical absorption and heating issues. Here, to address this gap, we demonstrate electrically driven rotation of micro-particles levitating in Paul traps. We show that micro-particles can be set to rotate stably at 150,000 rpm by operating in a hitherto unexplored parametrically driven regime using the particle electric quadrupolar moment. Moreover, the spin states of nitrogen-vacancy centers in diamonds undergoing full rotation were successfully controlled, allowing accurate angular trajectory reconstruction and demonstrating high rotational stability over extended periods. These achievements mark progress toward interfacing full rotation with internal magnetic degrees of freedom in micron-scale objects. In particular, it extends significantly the type of particles that can be rotated, such as ferromagnets, which offers direct implications for the study of large gyromagnetic effects at the micro-scale

Biofilm Mediated Calculus Formation in the Urinary Tract

Mineralization and subsequent calculus formation is a common complication of biofilm infections. In the urinary tract, these infected calculi often arise from infections by urease-producing bacteria. Ammonia, liberated by bacterial urease activity, increases urine pH, resulting in the precipitation of Ca and Mg as carbonateapatite {Ca10(PO4,CO3)6(OH,CO3)2} and struvite (NH4MgP04·6H2O). These minerals become entrapped in the organic matrix which surrounds the infecting organisms and ultimately grow into mature calculi. When the causative organisms grow on urinary catheters and stents, the resulting mineralization can partially or completely obstruct urine flow. Mineralization may also exacerbate tissue damage, lead to a Joss of kidney function, and aid in the dissemination of microorganisms into deeper tissues. Several factors influence mineral formation and growth during struvite urolithiasis. These include host factors such as urine chemistry and anatomy of the urinary tract, the presence and characteristics of any foreign objects such as catheters, and bacterial factors such as the type of organisms present and their virulence factors. This review will address these and other factors which influence biofilm mineralization and calculus formation in the urinary tract

Interactions among Amazon land use, forests and climate: prospects for a near-term forest tipping point

Some model experiments predict a large-scale substitution of Amazon forest by savannah-like vegetation by the end of the twenty-first century. Expanding global demands for biofuels and grains, positive feedbacks in the Amazon forest fire regime and drought may drive a faster process of forest degradation that could lead to a near-term forest dieback. Rising worldwide demands for biofuel and meat are creating powerful new incentives for agro-industrial expansion into Amazon forest regions. Forest fires, drought and logging increase susceptibility to further burning while deforestation and smoke can inhibit rainfall, exacerbating fire risk. If sea surface temperature anomalies (such as El Niño episodes) and associated Amazon droughts of the last decade continue into the future, approximately 55% of the forests of the Amazon will be cleared, logged, damaged by drought or burned over the next 20 years, emitting 15–26 Pg of carbon to the atmosphere. Several important trends could prevent a near-term dieback. As fire-sensitive investments accumulate in the landscape, property holders use less fire and invest more in fire control. Commodity markets are demanding higher environmental performance from farmers and cattle ranchers. Protected areas have been established in the pathway of expanding agricultural frontiers. Finally, emerging carbon market incentives for reductions in deforestation could support these trends

Decoupling of Deforestation and Soy Production in the Southern Amazon During the Late 2000s

From 2006-2010 deforestation in the Amazon frontier state of Mato Grosso decreased to 30% of its historical average (1996-2005) while agricultural production reached an all time high, achieving the oft-cited objective of increasing production while maintaining forest cover. This study combines satellite data with government deforestation and production statistics to assess land-use transitions and potential market and policy drivers associated with these trends. In the forested region of the state, increased soy production from 2001-2005 was entirely due to cropland expansion into previously cleared areas (74%) or forests (26%). From 2006-2010, 78% of production increases were due to expansion (22% to yield increases), with 91% on previously cleared land. Cropland expansion fell from 10% to 2% of deforestation between the two periods, with pasture expansion accounting for most remaining deforestation. Declining deforestation coincided with a collapse of commodity markets and implementation of policy measures to reduce deforestation. Soybean profitability has since increased to pre-2006 levels while deforestation continued to decline, suggesting that anti-deforestation measures may have influenced the agricultural sector. We found little evidence of leakage of soy expansion into cerrado in Mato Grosso or forests in neighboring Amazon states during the late 2000s, although leakage to more distant regions is possible. This study provides empirical evidence that reduced deforestation and increased agricultural production can occur simultaneously in tropical forest frontiers through productive use of already cleared lands. It remains uncertain whether government and industry-led policies can contain deforestation when market conditions again favor a boom in agricultural expansion

Chemistry, transport and dry deposition of trace gases in the boundary layer over the tropical Atlantic Ocean and the Guyanas during the GABRIEL field campaign

We present a comparison of different Lagrangian and chemical box model calculations with measurement data obtained during the GABRIEL campaign over the tropical Atlantic Ocean and the Amazon rainforest in the Guyanas, October 2005. Lagrangian modelling of boundary layer (BL) air constrained by measurements is used to derive a horizontal gradient (≈5.6 pmol/mol km<sup>−1</sup>) of CO from the ocean to the rainforest (east to west). This is significantly smaller than that derived from the measurements (16–48 pmol/mol km<sup>−1</sup>), indicating that photochemical production from organic precursors alone cannot explain the observed strong gradient. It appears that HCHO is overestimated by the Lagrangian and chemical box models, which include dry deposition but not exchange with the free troposphere (FT). The relatively short lifetime of HCHO implies substantial BL-FT exchange. The mixing-in of FT air affected by African and South American biomass burning at an estimated rate of 0.12 h<sup>−1</sup> increases the CO and decreases the HCHO mixing ratios, improving agreement with measurements. A mean deposition velocity of 1.35 cm/s for H<sub>2</sub>O<sub>2</sub> over the ocean as well as over the rainforest is deduced assuming BL-FT exchange adequate to the results for CO. The measured increase of the organic peroxides from the ocean to the rainforest (≈0.66 nmol/mol d<sup>−1</sup>) is significantly overestimated by the Lagrangian model, even when using high values for the deposition velocity and the entrainment rate. Our results point at either heterogeneous loss of organic peroxides and/or their radical precursors, underestimated photodissociation or missing reaction paths of peroxy radicals not forming peroxides in isoprene chemistry. We calculate a mean integrated daytime net ozone production (NOP) in the BL of (0.2±5.9) nmol/mol (ocean) and (2.4±2.1) nmol/mol (rainforest). The NOP strongly correlates with NO and has a positive tendency in the boundary layer over the rainforest

Hydroxyl radicals in the tropical troposphere over the Suriname rainforest: airborne measurements

Direct measurements of OH and HO<sub>2</sub> over a tropical rainforest were made for the first time during the GABRIEL campaign in October 2005, deploying the custom-built HORUS instrument (HydrOxyl Radical measurement Unit based on fluorescence Spectroscopy), adapted to fly in a Learjet wingpod. Biogenic hydrocarbon emissions were expected to strongly reduce the OH and HO<sub>2</sub> mixing ratios as the air is transported from the ocean over the forest. However, surprisingly high mixing ratios of both OH and HO<sub>2</sub> were encountered in the boundary layer over the rainforest. <br><br> The HORUS instrumentation and calibration methods are described in detail and the measurement results obtained are discussed. The extensive dataset collected during GABRIEL, including measurements of many other trace gases and photolysis frequencies, has been used to quantify the main sources and sinks of OH. Comparison of these measurement-derived formation and loss rates of OH indicates strong previously overlooked recycling of OH in the boundary layer over the tropical rainforest, occurring in chorus with isoprene emission