The effect of different compost applications in organic production of lettuce (Lactuca sativa L.)

It is well-known that compost and manure applications to all kinds of soils if these organic materials are mature and composted under favorable conditions result in improved soil fertility and crop production in terms of yield and quality, but because manure is expensive in our region and the application of in-farm production compost for organic lands and farms of Turkey is limited, there is a great and urgent need for demonstrate compost using advantages to soil fertility, plant yield-quality and food safety (Kir 2006). Vegetables account for only approximately 2% of total organic production in Turkey, but there is great potential for growth of organic production for both export and domestic consumption of organic products in our country. Lettuce (Lactuca sativa L.) is one of the most important species for testing effects of compost applications because of its sensitivity related with phyto-toxic effects of compost (Fuchs et al. 2008) and very important to find out productivity and sustainable production levels in crop production. It is obtained from the results at the end of the first two-year trials, respectively of the three year-planned research under organic management (framework of regulations of EU and Turkey) that (1) the artificial organic materials sourced from farms can be composted and applied to lettuce production to get a great profit in terms of environment and economic aspects of organic lettuce production significantly, (2) promising improvement of industry of compost production can be expected, (3) Organic lettuce can be consumed as microbiologically safe, (4) high quality lettuce production can be attained by using compost

SOM Loss and Soil Quality in the Clear Creek, IA

The Clear Creek, IA Experimental Watershed (CCEW), which drains to the Iowa River, experiences severe surface erosion due to a combination of high slopes, erodible soils, and extensive agriculture. Concurrent with soil loss is the removal of Soil Organic Matter (SOM). High values of SOM have been related to soil quality; therefore, excessive SOM loss corresponds to degrading soil health. Soil quality assessments are important tools for evaluating management practices in agricultural systems; however, it is difficult to measure soil quality directly at the watershed scale because it varies with a number of site-specific soil characteristics. The coupling of soil surveys with GIS and Non-Point Source computer simulation models will effectively forecast the impacts of ever-changing management practices on soil quality at the watershed scale in less time. NPS models can be extended to evaluate the movement of additional particle-bound constituents like SOM, by incorporating erosion rates and enrichment ratios. The ANNualized AGricultural Non-Point Source pollution modeling system (AnnAGNPS) was used to evaluate upland erosion, enrichment ratios, and SOM loss at the watershed scale in the headwaters of the CCEW using current crop rotations. Gross erosion rates averaged 7.73 MT/ha/yr for individual cells within the watershed. In addition, enrichment ratios, which were determined using gross and net erosion values from AnnAGNPS, were coupled with an organic matter coverage map of the watershed to determine an SOM loss of0.41 MT/ha/yr, which was similar to the loss rates determined by AnnAGNPS (0.29 MT/ ha/yr). To understand the state of soil health in this watershed, the NRCS Soil Conditioning Index (SCI) was determined for the watershed. The average SCI for the watershed was 0.38, which suggests improving soil health conditions. This improvement is most probably due to conservation practices like reduced tillage

PHR: A parallel hierarchical radiosity system with dynamic load balancing

In this paper, we present a parallel system called PHR for computing hierarchical radiosity solutions of complex scenes. The system is targeted for multi-processor architectures with distributed memory. The system evaluates and subdivides the interactions level by level in a breadth first fashion, and the interactions are redistributed at the end of each level to keep load balanced. In order to allow interactions freely travel across processors, all the patch data is replicated on all the processors. Hence, the system favors load balancing at the expense of increased communication volume. However, the results show that the overhead of communication is negligible compared with total execution time. We obtained a speed-up of 25 for 32 processors in our test scenes. © 2005 Springer Science + Business Media, Inc

54/07/28 Why Don\u27t Police Quiz Top Suspect: An Editorial

This editorial, published two days after the conclusion of the Coroner\u27s Inquest, describes Sam as a proven liar who is being shielded by his family and demands that he be taken to police headquarters for further questioning. It declares that if average people\u27 were involved in this murder it would have been cleaned up long ago.https://engagedscholarship.csuohio.edu/sheppard_maxwell_articles/1004/thumbnail.jp

Relationships of Polychlorinated Biphenyls and Dichlorodiphenyldichloroethylene (p,p’-DDE) with Testosterone Levels in Adolescent Males

Background: Concern persists over endocrine-disrupting effects of persistent organic pollutants (POPs) on human growth and sexual maturation. Potential effects of toxicant exposures on testosterone levels during puberty are not well characterized. Objectives: In this study we evaluated the relationship between toxicants [polychlorinated biphenyls (PCBs), dichlorodiphenyldichloroethylene (p,p´-DDE), hexachlorobenzene (HCB), and lead] and testosterone levels among 127 Akwesasne Mohawk males 10 to \u3c 17 years of age with documented toxicant exposures. Methods: Data were collected between February 1996 and January 2000. Fasting blood specimens were collected before breakfast by trained Akwesasne Mohawk staff. Multivariable regression models were used to estimates associations between toxicants and serum testosterone, adjusted for other toxicants, Tanner stage, and potential confounders. Results: The sum of 16 PCB congeners (Σ16PCBs) that were detected in ≥ 50% of the population was significantly and negatively associated with serum testosterone levels, such that a 10% change in exposure was associated with a 5.6% decrease in testosterone (95% CI: –10.8, –0.5%). Of the 16 congeners, the more persistent ones (Σ8PerPCBs) were related to testosterone, whereas the less persistent ones, possibly reflecting more recent exposure, were not. When PCB congeners were subgrouped, the association was significant for the sum of eight more persistent PCBs (5.7% decrease; 95% CI: –11, –0.4%), and stronger than the sum of six less persistent congeners (3.1% decrease; 95% CI: –7.2, 0.9%). p,p´-DDE was positively but not significantly associated with serum testosterone (5.2% increase with a 10% increase in exposure; 95% CI: –0.5, 10.9%). Neither lead nor HCB was significantly associated with testosterone levels. Conclusions: Exposure to PCBs, particularly the more highly persistent congeners, may negatively influence testosterone levels among adolescent males. The positive relationship between p,p´-DDE and testosterone indicates that not all POPs act similarly

MicroRNA-218 instructs proper assembly of hippocampal networks

The assembly of the mammalian brain is orchestrated by temporally coordinated waves of gene expression. Post-transcriptional regulation by microRNAs (miRNAs) is a key aspect of this program. Indeed, deletion of neuron-enriched miRNAs induces strong developmental phenotypes, and miRNA levels are altered in patients with neurodevelopmental disorders. However, the mechanisms used by miRNAs to instruct brain development remain largely unexplored. Here, we identified miR-218 as a critical regulator of hippocampal assembly. MiR-218 is highly expressed in the hippocampus and enriched in both excitatory principal neurons (PNs) and GABAergic inhibitory interneurons (INs). Early life inhibition of miR-218 results in an adult brain with a predisposition to seizures. Changes in gene expression in the absence of miR-218 suggest that network assembly is impaired. Indeed, we find that miR-218 inhibition results in the disruption of early depolarizing GABAergic signaling, structural defects in dendritic spines, and altered intrinsic membrane excitability. Conditional knockout of Mir218-2 in INs, but not PNs, is sufficient to recapitulate long-term instability. Finally, de-repressing Kif21b and Syt13, two miR-218 targets, phenocopies the effects on early synchronous network activity induced by miR-218 inhibition. Taken together, the data suggest that miR-218 orchestrates formative events in PNs and INs to produce stable networks