Understanding soil nitrogen supply: organic matter quality and quantity

The soil organic matter (SOM) contents of organic and conventionally farmed soils were compared. Whilst the quantity of SOM was found to be similar with both systems, the quality of SOM differed in respect of higher amounts of N released by the organic soils under anaerobic incubation. This indicated a greater potential rate of mineralization and suggested that the inherent fertility of the organic soils had been improve

FGF2 promotes Msx2 stimulated PC‐1 expression via Frs2/MAPK signaling

PC‐1 is an enzymatic generator of pyrophosphate and a critical regulator of tissue mineralization. We previously showed that fibroblast growth factor‐2 (FGF2) specifically induces PC‐1 expression in calvarial pre‐osteoblasts and that this occurs via a transcriptional mechanism involving Runx2. Because aberrant FGF signaling and Msx2 activity result in similar craniofacial skeletal defects and because Msx2 is an established regulator of osteoblastic gene expression, here we investigate Msx2 as an additional mediator of PC‐1 gene expression. mRNA analysis and experiments utilizing PC‐1 gene promoter/luciferase reporter constructs demonstrate that Msx2 promotes transcription of the PC‐1 gene downstream of FGF2. Results indicate that both Msx2 and Runx2 are recruited to a conserved core Msx2 binding site within the PC‐1 gene promoter upon FGF2 stimulation, and that Msx2 and Runx2 function together to induce PC‐1 gene expression in osteoblastic cells. Here we show that FGF signaling promotes Msx2 transcriptional activity on the PC‐1 gene promoter via the Frs2/MAPK signaling pathway. To our knowledge, this is the first report of Msx2 functioning as a transcriptional enhancer downstream of FGF2 in calvarial pre‐osteoblasts. As activating mutations in FGF receptors and Msx2 result in similar craniofacial skeletal disorders, our findings support the idea that FGF signaling and Msx2 activity influence cranial osteogenesis via the same molecular mechanism. J. Cell. Biochem. 111: 1346–1358, 2010. © 2010 Wiley‐Liss, Inc.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/92096/1/22861_ftp.pd

Omni-gravity Hydroponics for Space Exploration

As part of the NASA Plant Water Management technology demonstration experiments, a capillary fluidics hydroponic system that can function in a variety of gravity environments has been developed and tested for crop production in space. A passive liquid delivery method is employed that drastically reduces the number of contaminable moving parts providing a high reliability solution requiring minimal resources for operation. The terrestrial, lunar, and Martian environments are managed in a gravity-dominated mode, while the low-gravity transit and orbit environments are managed in a capillary fluidics mode, where the role of gravity is replaced by the equally passive effects of surface tension, conduit shape, and wettability. The unique considerations for priming, germination, aeration, nutrient supply, root accommodation, layout, crew interaction, etc. are highlighted. Design guides for system function are provided along with high Technology Readiness Level demonstrations of the system during terrestrial and drop tower tests. Long duration tests are planned on short schedule aboard the International Space Station in 2019

Demographics and Functional Outcome of Toe Fractures

Toe fractures are common; however, there are few data on demographics and functional outcome. We studied outcomes in 339 consecutive patients with toe fractures treated between January 2006 and September 2008. Two hundred and sixty-four patients, aged 16 to 75, were mailed an outcome questionnaire, and overall subjective satisfaction with the outcome of treatment was measured using a visual analog scale (VAS). Most frequently affected were the first (38%) and fifth (30%) toes, and most (75.6%) of the fractures were caused by stubbing or crush injury. More than 95% of the fractures were displaced less than 2 mm, and all of the fractures were treated conservatively. The questionnaire was returned by 141 (53%) patients with a median follow-up of 27 months. Respondents were female in 57.4% of cases and had a median age of 45 years. The median AOFAS score was 100 (P25, P75= 93,100) points; the median VAS was 10 (P25, P75= 8, 10) points. Univariate regression analysis revealed no statistically significant associations between outcome and the particular toe or phalanx involved, number of fractured toes, fracture type and location, articular involvement, gender, age, body mass index, smoking habits, and the presence of diabetes mellitus. Satisfaction VAS was dependent on age (P = .047) and gender (P = .049) in the multivariate analysis. The AOFAS midfoot score was not influenced by any of the covariates. This is the first epidemiological investigation using 2 outcome-scoring systems to determine function and satisfaction following treatment of toe fractures

Modulation of Magnetospheric Substorm Frequency: Dipole Tilt and IMF By Effects

Substorm activity is heavily influenced by the Interplanetary Magnetic Field (IMF) Bz component and magnetospheric substorms occur most frequently when Bz is strongly negative. The substorm occurrence rate is also affected by the magnitude of the By component, but it is usually presumed that this contribution is independent of the sign of By. Using five independent substorm onset lists, we show that substorm activity does depend on the sign of By near the solstices. Specifically, we show that substorms occur more frequently when By and the dipole tilt angle Ψ have different signs as opposed to when they have the same sign. These results confirm that the magnetosphere exhibits an explicit dependence on the polarity of By for nonzero Ψ, as other recent studies have suggested, and imply variation in the dayside reconnection rate and/or the magnetotail response. On the other hand, we find no clear relationship between substorm intensity and By regardless of Ψ. Last, for the onset list based on identifying negative bays at auroral latitudes, we observe an overall trend of more frequent onsets for positive By, regardless of season. However, substorm frequency in the other four substorm lists does not exhibit an overall preference for positive By. We show that this phenomenon is very likely a consequence of the particular substorm identification method (i.e., identification of negative bays), which is affected by local ionospheric conditions that depend on By and Ψ.publishedVersio

Magnetic Effects of Plasma Pressure Gradients in the Upper F Region

The Swarm satellites fly at altitudes that at polar latitudes are generally assumed to only contain currents that are aligned with the local magnetic field. Therefore, disturbances along the main field direction are mainly signatures of auroral electrojet currents, with a relatively smooth structure due to the distance from the currents. Here we show that superimposed on this smooth signal is an irregular pattern of small perturbations, which are anticorrelated with the plasma density measured by the Langmuir probe. We show that the perturbations can be remarkably well reproduced by assuming they represent a j  × B force, which balances the plasma pressure gradient implied by the density variations. The associated diamagnetic current, previously reported to be most important near the equator, appears to be a ubiquitous phenomenon also at polar latitudes. A spectral analysis indicates that this effect dominates magnetic field intensity variations at small‐scale sizes of a few tens of kilometers.publishedVersio

Testing the mirror symmetry of Birkeland and ionospheric currents with respect to magnetic latitude, dipole tilt angle, and IMF By

It is often assumed that on average, polar ionospheric electrodynamics in the Northern and Southern Hemispheres are mirror symmetric or antisymmetric with respect to the interplanetary magnetic field By component and the dipole tilt angle ψ. For example, one might assume that the average Birkeland current density j at magnetic latitude λ is equal to the current density at magnetic latitude −λ if the signs of By and ψ are reversed and all other parameters are equal: j(λ, By, ψ, … ) = j(−λ, −By, −ψ, … ). This is a convenient assumption for empirical models, since it effectively doubles the amount of information that a measurement made in one hemisphere contains. In this study we use the Average Magnetic field and Polar current System (AMPS) model to quantify to what extent the assumption holds for Birkeland and ionospheric currents. The AMPS model is an empirical model based on Swarm and CHAMP magnetic field measurements, with no constraints on hemispheric symmetries, and with differences in main magnetic field geometry as well as biases in data point distributions in magnetic coordinates accounted for. We show that when averaged over IMF clock angle orientation, the total ionospheric divergence-free current in each hemisphere largely satisfies the mirror symmetry assumption. The same is true for the total Birkeland current in each hemisphere except during local winter, during which the Northern Hemisphere tends to dominate. We show that this local winter asymmetry is consistent with the average winter hemispheric asymmetry in total precipitating electron current derived from Fast Auroral SnapshoT (FAST) satellite observations. We attribute this and other more subtle deviations from symmetry to differences in sunlight distribution in magnetic coordinates, as well as magnetic field strength and its influence on ionospheric conductivity. Important departures from mirror symmetry also arise for some IMF clock angle orientations, particularly those for which IMF Bz > 0, as suggested by other recent studies.publishedVersio

Prospective Study Examining Clinical Outcomes Associated with a Negative Pressure Wound Therapy System and Barker’s Vacuum Packing Technique

Background The open abdomen has become a common procedure in the management of complex abdominal problems and has improved patient survival. The method of temporary abdominal closure (TAC) may play a role in patient outcome. Methods A prospective, observational, open-label study was performed to evaluate two TAC techniques in surgical and trauma patients requiring open abdomen management: Barker’s vacuum-packing technique (BVPT) and the ABTheraTM open abdomen negative pressure therapy system (NPWT). Study endpoints were days to and rate of 30-day primary fascial closure (PFC) and 30-day all-cause mortality. Results Altogether, 280 patients were enrolled from 20 study sites. Among them, 168 patients underwent at least 48 hours of consistent TAC therapy (111 NPWT, 57 BVPT). The two study groups were well matched demographically. Median days to PFC were 9 days for NPWT versus 12 days for BVPT (p = 0.12). The 30-day PFC rate was 69 % for NPWT and 51 % for BVPT (p = 0.03). The 30-day all-cause mortality was 14 % for NPWT and 30 % for BVPT (p = 0.01). Multivariate logistic regression analysis identified that patients treated with NPWT were significantly more likely to survive than the BVPT patients [odds ratio 3.17 (95 % confidence interval 1.22–8.26); p = 0.02] after controlling for age, severity of illness, and cumulative fluid administration. Conclusions Active NPWT is associated with significantly higher 30-day PFC rates and lower 30-day all-cause mortality among patients who require an open abdomen for at least 48 h during treatment for critical illness