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Soil aggregation physically protects soil organic matter and promotes soil carbon persistence through microaggregate formation and organo-mineral associations. Tillage is a ubiquitous disturbance to arable soil that disrupts aggregation, thus affecting microbial resource availability, soil microhabitat conditions, and microbial interactions. We investigated how tillage affects bacterial community composition of soil microaggregate fractions (53–250 µm), specifically the free microaggregate fraction in bulk soil, and the occluded microaggregate fraction from within macroaggregates, using two long-term tillage vs. no-tillage experiments in southern WI, U.S., that represent two different silt loam soils (Alfisol and Mollisol). We applied 16S rRNA gene amplicon sequencing to characterize the effects of tillage on microaggregate bacterial communities by relating compositional changes and ecological community assembly patterns to various tillage-driven changes in the soil environment, including aggregate size distribution and carbon content. Tillage homogenized soil bacterial communities, as quantified by increased compositional similarity at both within-plot and between-plot scales, and community assembly was increasingly influenced by homogenizing dispersal with tillage. We did not identify major distinctions between bacterial communities of the free and occluded microaggregate fractions, thus highlighting how soil microaggregates readily shift between these operationally defined fractions in temperate annual cropping systems, where the soil environment is subject to drastic seasonal changes that are exacerbated by tillage. With this study, we improve our understanding of the microbial response to soil disturbance, and thus the potential mechanisms through which disturbances like tillage affect soil carbon persistence.HighlightsTillage homogenized soil bacterial communities, within and between plotsHomogenizing dispersal drove community assembly under tillageFree and occluded microaggregate fractions hosted similar communities

It is important for the surgeon to determine the position of the CI electrode array during and after its placement within the cochlea. Most preferably, this should be within the scala tympani to obtain the best audiological outcome. Thus, misplacement into the scala vestibuli or tip fold-over should be prevented. Since there are different ways to ensure proper positioning of the electrode array within the scala tympani (e.g., intraoperative radiography, electrophysiological recordings), our study was aimed at detecting intraoperative electrophysiologic characteristics to better understand the mechanisms of those electrode tip fold-overs. In a multi-centric, retrospective case–control series, patients with a postoperatively by radiography detected tip fold-over in perimodiolar electrodes were included. The point of fold-over (i.e., the electrode position) was determined and the intraoperative Auto-NRT recordings were analysed and evaluated. Four patients were found to have an electrode tip fold-over (out of 85 implantees). Significant changes of the Auto-NRT recordings were not detected. All tip fold-overs occurred in the most apical part of the electrodes. Cochlear implantation for hearing impaired patients plays a decisive role in modern auditory rehabilitation. Perimodiolar electrode arrays may fold over during the insertion and, hence, could have a negative impact on audiological outcome. Characteristic electrophysiologic changes to possibly predict this were not found in our series.

Accurate estimation of nitrogen (N) balance (a measure of potential N losses) in producer fields requires information on grain N concentration (GNC) to estimate grain-N removal, which is rarely measured by producers. The objectives of this study were to (i) examine the degree to which variation in GNC can affect estimation of grain-N removal, (ii) identify major factors influencing GNC, and (iii) develop a predictive model to estimate GNC, analyzing the uncertainty in predicted grain-N removal at field and regional levels. We compiled GNC data from published literature and unpublished databases using explicit criteria to only include experiments that portray the environments and dominant management practices where maize is grown in the US North Central region, which accounts for one-third of global maize production. We assessed GNC variation using regression tree analysis and evaluated the ability of the resulting model to estimate grain-N removal relative to the current approach using a fixed GNC. Across all site-year-treatment cases, GNC averaged 1.15%, ranging from 0.76 to 1.66%. At any given grain yield, GNC varied substantially and resulted in large variation in estimated grain-N removal and N balance. However, compared with GNC, yield differences explained much more variability in grain-N removal. Our regression tree model accounted for 35% of the variation in GNC, and returned physiologically meaningful associations with mean air temperature and water balance in July (i.e., silking) and August (i.e., grain filling), and with N fertilizer rate. The predictive model has a slight advantage over the typical approach based on a fixed GNC for estimating grain-N removal for individual site-years (root mean square error: 17 versus 21 kg N ha−1, respectively). Estimates of grain-N removal with both approaches were more reliable when aggregated at climate-soil domain level relative to estimates for individual site-years.

"Meni je to normalno" Crvena maska Lupusa koji se kao bolest nametnuo i postao dio mene kao moj sastavni dio, dok svako prikrivanje tog su života postaje maskiranje i svojevrsna maska. Skrivena iza maske normalnog lica, ulazim u lik običnog čovjeka, tako skrivena moja pojava ne izaziva pažnju. To crvenilo je teško suzbiti. Pojačava se uslijed više temperature okoline, izloženosti suncu, emotivnim angažmanom i uzbuđenjem. Maska koja se stvara na licu postaje tako neodvojivi identitetski znak. Skrivanje iza maske lica zdravog organizma omogućuje nevidljivost, život inkognito, bez neželjene pažnje.

Agriculture in the Midwest region of the United States is based on intensive corn (Zea mays L.) production that provides food, feed, and fuel. Crop rotation is a vital management option for improved yield and environment preservation. Three rotation systems—continuous corn (CC), corn–soybean (Glycine max [L.] Merr.; CS), and corn–soybean–wheat (Triticum aestivum L.; CSW)—were selected to study their effects on grain yields and carbon (C) and nitrogen (N) accumulation and partitioning within corn grain, stover, and cob plant components. The experiment was conducted at three pre-established crop rotation experiments located at three sites in Wisconsin. Biomass sampling was performed in four consecutive years (2011 to 2014). Analysis of variance showed differences in location for most variables, an effect of crop rotation on stover biomass and stover C, and an interaction effect between location and rotation on soybean grain yield. Averaged across years and locations, final corn and soybean grain yield increased with rotation complexity where corn in the CSW rotation had 15% and 8% greater yield than CC and CS rotation, respectively. Overall, the biomass distribution among corn plant parts was 52%, 41%, and 7% for grain, stover, and cob, respectively. Stover and cobs harvested from corn grown in monoculture produced approximately 11% (0.54 Mg C ha−1) less C than corn grown in either CS or CSW rotation. Across rotations, the accumulation of N in plant tissues was not significantly different. However, these results show that crop rotation can increase grain yield and biomass C and partially offset the difference in soil C, which is expected to be greater under CC.

Prohexadione-calcium (PHD) can enhance establishment of alfalfa (Medicago sativa L.) interseeded into silage corn (Zea mays L.), but optimal application rates and timing for this growth regulator are unknown. Two experiments examined how single or split applications of 0.25 to 1.0 kg a.i. ha–¹ of PHD applied to 15 or 25 cm tall glyphosate-resistant alfalfa seedlings influenced growth, stand density, and yield of alfalfa and corn compared to untreated controls. The PHD treatments reduced seedling top growth by 13 to 32% and increased stand density of alfalfa by 19 to 81% in three out of four locations and alfalfa dry matter yield by 4 to 23% in two out of four locations the following year. Alfalfa responses were not consistently influenced by the rate and timing of PHD application, but higher rates proved advantageous under conditions that impaired alfalfa seedling survival under corn. Application of PHD on alfalfa had little or no effect on corn heights and yields. Corn population and alfalfa seeding rates influenced corn silage yield and alfalfa stand counts in at least one location, but these factors had little effect on crop responses to PHD. Combined 2-yr yields of corn followed by alfalfa were 12% greater for the interseeding system than for solo-seeded corn followed by spring seeded alfalfa. Overall, a single application of 0.5 to 1.0 kg a.i. ha–¹ of PHD on 15 to 25 cm tall alfalfa proved effective for improving stand density and occasionally first year yield of glyphosate-resistant alfalfa.

In response to climate change, there is a need to adopt more resilient cropping systems for increased productivity. In this study, three corn (Zea mays L.)-based rotations—continuous corn (CC), corn–soybean (Glycine max [L.] Merr.; CS), and corn–soybean–wheat (Triticum aestivum L.; CSW), where all residues were retained on the field after harvest—were selected to study their effects on soil properties at three managed sites in Wisconsin—Arlington, Lancaster, and Marshfield. Soil core samples were collected at four depths (0 to 10, 10 to 20, 20 to 40, and 40 to 60 cm) in 2011. In 2013 and 2015, soil core samples were collected at the two top depths. Soil water retention (WR), plant available water (PAW), bulk density (BD), soil carbon (C), soil nitrogen (N), and C/N ratio were evaluated. Water retention was determined from 0 to 10 and 10 to 20 cm depths at five different matric potentials (Ψ = 0, −5, −10, −33, and −1,500 kPa). There was a significant location × depth interaction across soil properties, which could be associated with differences in management among locations. Averaged across location, CC and CSW rotations had greater water content and PAW across WR tensions than CS rotation at 0 to 10 cm depth, while no differences existed at 10 to 20 cm depth. Crop rotations had similar BD across locations and depths (1.37 to 1.41 g cm−3). A significant three-way location × depth × rotation interaction for C and N amount was affected with generally higher C and N amount in CSW rotation at Lancaster and smaller differences among crop rotations at Arlington and Marshfield. Observed low soil C/N ratio values (

Fungal diseases can have a detrimental impact on soybean and corn yield. Foliar fungicides are used to manage fungal diseases and minimize yield loss, along with cultural practices like tillage and crop rotation. Prophylactic foliar fungicide use does not consistently increase yield for corn and soybean, especially when disease pressures are low. Also, there are concerns about the impact of fungicides on non-target organisms, including fungi living in the soil. We tested the effects of tillage, crop rotation, and foliar fungicide use on corn grain and soybean seed yield over three growing seasons. For both crops, rotation was key to achieving high yields, although there was an interaction of tillage × crop rotation for soybean and crop rotation × fungicide for corn. For soybean seed yield, both foliar fungicide treatments showed a small yield increase over untreated plots. Additionally, we assessed bulk soil fungal communities in a subset of treatments (crop rotation and fungicide treatments in no-till plots), using ITS sequencing and PLFA-FAME. We observed distinct fungal communities in the continuously cropped treatments, while annually rotated communities were very similar. There was also greater overall microbial biomass and a higher relative abundance of arbuscular mycorrhizae fungi associated with continuous corn. There were no differences in soil fungal communities or microbial biomass associated with foliar fungicide treatments. Based on our findings, we recommend that farmers use integrated pest management strategies to manage fungal diseases, which may include fungicide applications, if they are justified by economic disease thresholds or prediction tools.

A method for the selective cross-dimerization of terminal aryl alkynes with propargyl alcohols to afford linear (E)-enynol products is reported. The complex [Pd(μ-κ2-O,O-OAc)(κ2-C,P-(t-Bu)2PCH2C(Me)2CH2)]2 selectively affords (E)-5-aryl-2-en-4-yn-1-ol products in good yields under mild conditions with high chemo-, regio-, and stereoselectivity. In contrast, previously reported examples of this reaction afford the branched 4-aryl-2-hydroxymethanol-1-buten-3-yne. Propargyl amides are also selectively cross-dimerized, but with lower regioselectivity for the linear enyne. The method has been applied to the synthesis of (E)-5-phenyl-2-penten-4-yn-1ol, which is a precursor to type 2 diabetes drug candidate NNC 61-4655, in 72% yield from phenylacetylene and propargyl alcohol. The palladacycle precatalyst reacts with aryl alkynes to afford the first example of a dimeric palladacycle complex with a μ-κ2-C1,C1-bound acetylide ligand. This complex is observed during the catalytic reaction and is a competent precatalyst.

Crop simulation models are used at the field scale to estimate crop yield potential, optimize current management, and benchmark input-use efficiency. At issue is the ability of crop models to predict local and regional actual yield and total production without need of site-year specific calibration of internal parameters associated with fundamental physiological processes. In this study, a well-validated maize simulation model was used to estimate yield potential for 45 locations across the U.S. Corn Belt, including both irrigated and rainfed environments, during four years (2011–2014) that encompassed diverse weather conditions. Simulations were based on measured weather data, dominant soil properties, and key management practices at each location (including sowing date, hybrid maturity, and plant density). The same set of internal model parameters were used across all site-years. Simulated yields were upscaled from locations to larger spatial domains (county, agricultural district, state, and region), following a bottom-up approach based on a climate zone scheme and distribution of maize harvested area. Simulated yields were compared against actual yields reported at each spatial level, both in absolute terms as well as deviations from long-term averages. Similar comparisons were performed for total maize production, estimated as the product of simulated yields and official statistics on maize harvested area in each year. At county-level, the relationship between simulated and actual yield was better described by a curvilinear model, with decreasing agreement at higher yields (>12 Mg ha−1). Comparison of actual and simulated yield anomalies, as estimated from the yearly yield deviations from the long-term actual and simulated average yield, indicated a linear relationship at county-level. In both cases (absolute yields and yield anomalies comparisons), the agreement increased with increasing spatial aggregation (from county to region). An approach based on long-term actual and simulated yields and year-specific simulated yield allowed estimation of actual yield with a high degree of accuracy at county level (RMSE ≤ 18%), even in years with highly favorable weather or severe drought. Estimates of total production, which are of greatest interest to buyers and sellers in the market, were also in close agreement with actual production (RMSE ≤ 22%). The approach proposed here to estimate yield and production can complement other approaches that rely on surveys, field crop cuttings, and empirical statistical methods and serve as basis for in-season yield and production forecasts.

Nitrous oxide (N2O) is a potent greenhouse gas with implication for climate change. Agriculture accounts for 10% of all greenhouse gas emissions in the United States, but 75% of the country's N2O emissions. In the absence of PRE herbicides, weeds compete with soybean for available soil moisture and inorganic N, and may reduce N2O emissions relative to a weed-free environment. However, after weeds are killed with a POST herbicide, the dead weed residues may stimulate N2O emissions by increasing soil moisture and supplying carbon and nitrogen to microbial denitrifiers. Wider soybean rows often have more weed biomass, and as a result, row width may further impact how weeds influence N2O emissions. To determine this relationship, field studies were conducted in 2013 and 2014 in Arlington, WI. A two-by-two factorial treatment structure of weed management (PRE + POST vs. POST-only) and row width (38 or 76 cm) was arranged in a randomized complete block design with four replications. N2O fluxes were measured from static gas sampling chambers at least weekly starting 2 wk after planting until mid-September, and were compared for the periods before and after weed termination using a repeated measures analysis. N2O fluxes were not influenced by theweedbywidthinteraction orwidthbefore termination, after termination, or for the full duration of the study at P ≤ 0.05. Interestingly, we observed that POST-only treatments had lower fluxes on the sampling day immediately prior to POST application (P = 0.0002), but this was the only incidence whereweedinfluenced N2O fluxes, and overall, average fluxes from PRE + POST and POST-only treatments were not different for any period of the study. Soybean yield was not influenced bywidth(P = 0.6018) orweedbywidth(P = 0.5825), but yield was 650 kg ha−1higher in the PRE + POST than POST-only treatments (P = 0.0007). These results indicate that herbicide management strategy does not influence N2O emissions from soybean, and the use of a PRE herbicide prevents soybean yield loss.

Atrazine has been used for control of many weeds, primarily broadleaf weeds, in U.S. corn fields since 1957. Recently, the adoption of glyphosate-resistant corn hybrids have led to glyphosate eclipsing atrazine as the most commonly used herbicide in corn production. However, the evolution and spread of glyphosate-resistant weeds is a major concern. Atrazine use in Wisconsin is prohibited in 102 areas encompassing 0.49 million ha where total chlorinated residues were found in drinking water wells at concentrations > 3 μg L−1. Atrazine has been prohibited in many of those areas for > 10 yr, providing an opportunity to evaluate weed community composition differences due to herbicide regulation. In question, has the abundance of broadleaf weeds increased, coupled with an increased reliance on glyphosate, where atrazine use has been discontinued? To answer this, an online questionnaire was distributed to Wisconsin growers in June and then weeds present in 343 fields in late July through mid-September in 2012 and 2013 were counted. Data were summarized for frequency, uniformity, density, and relative abundance to compare weed community composition in fields with discontinued vs. recent atrazine use. Growers used glyphosate in 70 vs. 54% of fields with discontinued vs. recent atrazine use, respectively (P = 0.021). Moreover, broadleaf weeds were found more frequently, (73 vs. 61%; P = 0.03), they had 50% greater in-field uniformity (P = 0.002), and density was 0.4 vs. 0.19 plants m−2(i.e., twofold greater; P < 0.0001) in discontinued vs. recent atrazine-use fields. Changes were most evident with troublesome glyphosate-resistant broadleaf weeds such asAmaranthusspecies and giant ragweed. In conclusion, weed community composition consisted of more broadleaf weeds in fields where atrazine has not been used in the recent decade coupled with greater glyphosate use. These results provide evidence of negative long-term implications for glyphosate resistance where growers increased reliance on glyphosate in place of atrazine.

Atrazine is an important herbicide for broadleaf weed control in corn. Use rates have declined in many corn production systems due to environmental concerns and the availability of other effective herbicides, especially glyphosate in glyphosate-resistant hybrids. However, using multiple effective herbicide modes of action is ever more important because occurrence of herbicide-resistant weeds is increasing. An experiment to compare application timings of reduced rates of atrazine to benefit resistance management in broadleaf weeds while protecting corn yield was conducted in Wisconsin across four site-years in 2012 and 2013. Herbicide treatments consisted of five atrazine rate and timing combinations and three POST base herbicides: glyphosate, glufosinate, and tembotrione. Metolachlor was applied PRE at 2.1 kg ai ha−1 for grass control in all treatments. A linear regression model estimated that atrazine rates ≥ 1.0 kg ai ha−1 applied PRE would prevent exposure of common lambsquarters plants to POST herbicides, but giant ragweed and velvetleaf exposure was not influenced by timing. Corn yield was also not influenced by atrazine rate and timing combinations at the α = 0.05 level; however, at P = 0.06, corn yield was greater for atrazine applied PRE at 1.1 kg ha−1 than for atrazine applied PRE at 0.5 kg ha−1, POST at 1.1 kg ha−1, or not at all. In summary, higher rates of atrazine applied PRE may improve yield, as reported by others, but this study concludes reduced rates of atrazine (i.e., ≤ 1.1 kg ha−1) applied to corn in a POST tank mixture combination provided more consistent control of giant ragweed, velvetleaf, and common lambsquarters compared with atrazine applied PRE. This information should help direct atrazine application timing applied POST when applied at low rates to improve proactive herbicide resistance management.

Hintergrund Bisphosphonate (BP) werden seit vielen Jahren sehr wirksam in der Therapie der schweren Osteoporose sowie in der Therapie maligner Grunderkrankungen, v. a. bei Knochenmetastasen, angewandt. Im Jahr 2003 wurde erstmals ein moglicher Zusammenhang zwischen einer Bisphosphonat-Therapie und dem Auftreten von Osteonekrosen des Kieferbereichs beschrieben. Bei der Bisphosphonat-assoziierten Kiefernekrose („bisphosphonate-related osteonecrosis of the jaws“, BRONJ) handelt es sich um ein auserst schwer therapierbares Krankheitsbild. In manchen Fallen ist der Allgemeinzustand der Patienten durch das maligne Grundleiden so stark beeintrachtigt, dass nur minimal-invasive Eingriffe moglich sind. Histopathologisch liegt eine akute bis chronische, sequestrierende Osteomyelitis vor, die verschiedene Areale des Kiefers betrifft und ausgedehnte Knochenresektionen notwendig machen kann. Aus diesem Grund kann diese Erkrankung teilweise mutilierend sein, nachhaltig Funktion und Asthetik des orofazialen Systems beeintrachtigen und damit deutlich die Lebensqualitat der Patienten vermindern. Ausloser der BRONJ sind zum Grosteil Zahnextraktionen ohne lokalplastische Deckung der Knochenwunde, ebenso ist eine Entstehung durch Mikrotraumata (z. B. Prothesendruckstellen) moglich.

To achieve low write current in high density Spin Transfer Torque Magnetic Random Access Memory (STT-MRAM) arrays, it is important to understand and co-optimize the different kinds of device switching currents, governed by different materials parameters. We demonstrate that double magnetic tunnel junctions (DMTJs) lower the switching current threshold I c0 by a factor of two when compared to conventional single MTJs. In single MTJs, the overdrive required to reach a write-error rate (WER) of 1E-6 was reduced by materials optimization from 53% to 29% a write-error rate (WER) of 1E-6 by materials optimization. Ultra-low switching current of 8 µA at WER = 1E-9 was achieved in an 11 nm MTJ with 10 ns write pulses.