Archaeal ammonia oxidizers respond to soil factors at smaller spatial scales than the overall archaeal community does in a high Arctic polar oasis

Archaea are ubiquitous and highly abundant in Arctic soils. Because of their oligotrophic nature, archaea play an important role in biogeochemical processes in nutrient-limited Arctic soils. With the existing knowledge of high archaeal abundance and functional potential in Arctic soils, this study employed terminal restriction fragment length polymorphism (t-RFLP) profiling and geostatistical analysis to explore spatial dependency and edaphic determinants of the overall archaeal (ARC) and ammonia-oxidizing archaeal (AOA) communities in a high Arctic polar oasis soil. ARC communities were spatially dependent at the 2–5 m scale (P < 0.05), whereas AOA communities were dependent at the �1 m scale (P < 0.0001). Soil moisture, pH, and total carbon content were key edaphic factors driving both the ARC and AOA community structure. However, AOA evenness had simultaneous correlations with dissolved organic nitrogen and mineral nitrogen, indicating a possible niche differentiation for AOA in which dry mineral and wet organic soil microsites support different AOA genotypes. Richness, evenness, and diversity indices of both ARC and AOA communities showed high spatial dependency along the landscape and resembled scaling of edaphic factors. The spatial link between archaeal community structure and soil resources found in this study has implications for predictive understanding of archaea-driven processes in polar oases

The whole genome sequence of the Mediterranean fruit fly, Ceratitis capitata (Wiedemann), reveals insights into the biology and adaptive evolution of a highly invasive pest species

The Mediterranean fruit fly (medfly), Ceratitis capitata, is a major destructive insect pest due to its broad host range, which includes hundreds of fruits and vegetables. It exhibits a unique ability to invade and adapt to ecological niches throughout tropical and subtropical regions of the world, though medfly infestations have been prevented and controlled by the sterile insect technique (SIT) as part of integrated pest management programs (IPMs). The genetic analysis and manipulation of medfly has been subject to intensive study in an effort to improve SIT efficacy and other aspects of IPM control

Common variants at ABCA7, MS4A6A/MS4A4E, EPHA1, CD33 and CD2AP are associated with Alzheimer's disease

We sought to identify new susceptibility loci for Alzheimer's disease through a staged association study (GERAD+) and by testing suggestive loci reported by the Alzheimer's Disease Genetic Consortium (ADGC) in a companion paper. We undertook a combined analysis of four genome-wide association datasets (stage 1) and identified ten newly associated variants with P ≤ 1 × 10−5. We tested these variants for association in an independent sample (stage 2). Three SNPs at two loci replicated and showed evidence for association in a further sample (stage 3). Meta-analyses of all data provided compelling evidence that ABCA7 (rs3764650, meta P = 4.5 × 10−17; including ADGC data, meta P = 5.0 × 10−21) and the MS4A gene cluster (rs610932, meta P = 1.8 × 10−14; including ADGC data, meta P = 1.2 × 10−16) are new Alzheimer's disease susceptibility loci. We also found independent evidence for association for three loci reported by the ADGC, which, when combined, showed genome-wide significance: CD2AP (GERAD+, P = 8.0 × 10−4; including ADGC data, meta P = 8.6 × 10−9), CD33 (GERAD+, P = 2.2 × 10−4; including ADGC data, meta P = 1.6 × 10−9) and EPHA1 (GERAD+, P = 3.4 × 10−4; including ADGC data, meta P = 6.0 × 10−10)

Genome-wide Analyses Identify KIF5A as a Novel ALS Gene

To identify novel genes associated with ALS, we undertook two lines of investigation. We carried out a genome-wide association study comparing 20,806 ALS cases and 59,804 controls. Independently, we performed a rare variant burden analysis comparing 1,138 index familial ALS cases and 19,494 controls. Through both approaches, we identified kinesin family member 5A (KIF5A) as a novel gene associated with ALS. Interestingly, mutations predominantly in the N-terminal motor domain of KIF5A are causative for two neurodegenerative diseases: hereditary spastic paraplegia (SPG10) and Charcot-Marie-Tooth type 2 (CMT2). In contrast, ALS-associated mutations are primarily located at the C-terminal cargo-binding tail domain and patients harboring loss-of-function mutations displayed an extended survival relative to typical ALS cases. Taken together, these results broaden the phenotype spectrum resulting from mutations in KIF5A and strengthen the role of cytoskeletal defects in the pathogenesis of ALS.Peer reviewe

Major General William Farrar Smith: critic of defeat and engineer of victory

Major General William Farrar Smith (1824-1903) played several key roles that contributed to Federal success in the Civil War. as a division commander and chief of engineers, Smith twice saved the Union Army from disastrous defeats. He also served as an important military critic of the tactical incompetence of fellow Union generals.;Smith\u27s first major Civil War contribution came as a division commander during the Peninsula campaign of 1862. at White Oak Swamp, his strong stand held back the pursuit of the Confederates and enabled the Army of the Potomac to reach its new supply base.;Smith commanded the Sixth Corps at Fredericksburg. Shocked by General Burnside\u27s wasteful attempts to take Marye\u27s Heights, Smith wrote to President Lincoln condemning Burnside\u27s plans. Burnside\u27s humiliating mud march in January 1863 validated Smith\u27s criticisms. But because of his indiscretion, and his friendship with General McClellan, who was under fire from Congressional Republicans, Smith was relieved of command and denied promotion to major general.;In October, as the chief engineer of the Army of the Cumberland, Smith made one of his greatest contributions to the war effort. The Confederates had nearly invested the Union Army at Chattanooga. But Smith devised and implemented a plan which restored Chattanooga\u27s communications and enabled the important city to be held.;General Grant was impressed with Smith and made him Eighteenth Corps commander. Smith\u27s success at the battle of Petersburg and his skills as a tactician led Grant to place the troops of the Army of the James under his command. Shortly afterwards, however, Grant became convinced that Smith\u27s censure of General Meade\u27s attack at Cold Harbor was directed at him. to end this criticism, Grant relieved Smith of command in July 1864. Nevertheless, on March 13, 1865, Congress recognized Smith\u27s distinguished service by brevetting him a major general. A thorough examination of his life and writings gives a revealing account of the war and offers a partial explanation of why the North took four years to defeat the South

Data from: Checkerboard score-area relationships reveal spatial scales of plant community structure

Identifying the spatial scale at which particular mechanisms influence plant community assembly is crucial to understanding the mechanisms structuring communities. It has long been recognized that many elements of community structure are sensitive to area; however the majority of studies examining patterns of community structure use a single relatively small sampling area. As different assembly mechanisms likely cause patterns at different scales we investigate how plant species co-occurrence patterns change with sampling unit scale. We use the checkerboard score as an index of species segregation, and examine species C-score-sampling area patterns in two ways. First, we show via numerical simulation that the C-score-area relationship is necessarily hump shaped with respect to sample plot area. Second we examine empirical C-score-area relationships in arctic tundra, grassland, boreal forest, and tropical forest communities. The minimum sampling scale where species co-occurrence patterns were significantly different from the null model expectation was at 0.1 m2 in the tundra, 0.2 m2 in grassland, and 0.2 Ha in both the boreal and tropical forests. Species were most segregated in their co-occurrence (maximum C-score) at 0.3 m2 in the tundra (0.54 m by 0.54 m quadrats), 1.5 m2 in the grassland (1.2 by 1.2 m quadrats), 0.26 Ha in the tropical forest (71 m by 71 m quadrats), and a maximum was not reached at the largest sampling scale of 1.4 Ha in the boreal forest. The most important finding is that the dominant scales of community structure in these systems are large relative to plant body size, and hence we infer that the dominant mechanisms structuring these communities must be at similarly large scales. This provides a method for identifying the spatial scales at which communities are maximally structured; ecologists can use this information to develop hypotheses and experiments to test scale-specific mechanisms that structure communities