The Role of Sweet Potato Resistance in the Population Dynamics and Development of Meloidogyne Incognita.

Root-knot nematode populations endemic to Louisiana soils were identified to species and race. Meloidogyne incognita (Kofoid and White) Chitwood, (MI) accounted for 97 percent of the populations identified. Of the M. incognita species 55 percent were Race 1, 38 percent Race 3, and 7 percent Race 4. Meloidogyne javanica represented 3 percent of the populations studied. Populations were compared to the M. incognita used in the LSU sweet potato breeding program (MIS) for their virulence on the susceptible \u27Centennial\u27 and resistant \u27Jasper\u27, \u27Jewel\u27, and L4-73. The populations varied in virulence to the sweet potato cultivars with some populations being more virulent than the MIS population. Several populations appeared capable of overcoming resistance exhibited by the sweet potato cultivars. The life cycle of MIS was studied on \u27Centennial\u27, \u27Jasper\u27, \u27Jewel\u27, and W-51. Varietal resistance did not inhibit the initial rate of juvenile penetration, but did reduce the number of juveniles that reached maturity. Resistance reduced the number of juveniles that reached maturity; however, the rate of nematode development was more rapid in the resistant \u27Jewel\u27 than the other cultivars. The effect of MIS on the growth of \u27Centennial\u27 and \u27Jasper\u27 was studied in field plots artifically infested with initial population densities (Pi) ranging from 0-10,000 MIS eggs per 500 cc of soil. Population dynamics were similar on both cultivars; however, higher mid season counts were recorded from \u27Centennial\u27 than from \u27Jasper\u27. The highest Pi levels did not produce the highest mid season counts. Initial Pi levels had similar effects on the growth of \u27Centennial\u27 and \u27Jasper\u27 sweet potatoes. Pi levels were negatively correlated with marketable roots produced and root weight, but positively correlated with total cracked roots, percent cracked roots, and cracking severity ratings. \u27Jasper\u27 was able to tolerate significantly higher Pi levels with better yields and root quality than \u27Centennial\u27. The incidence of cracking of the fleshy root was apparent on both cultivars at low Pi levels

A modified bacterial one-hybrid system yields improved quantitative models of transcription factor specificity

We examine the use of high-throughput sequencing on binding sites recovered using a bacterial one-hybrid (B1H) system and find that improved models of transcription factor (TF) binding specificity can be obtained compared to standard methods of sequencing a small subset of the selected clones. We can obtain even more accurate binding models using a modified version of B1H selection method with constrained variation (CV-B1H). However, achieving these improved models using CV-B1H data required the development of a new method of analysis—GRaMS (Growth Rate Modeling of Specificity)—that estimates bacterial growth rates as a function of the quality of the recognition sequence. We benchmark these different methods of motif discovery using Zif268, a well-characterized C2H2 zinc-finger TF on both a 28 bp randomized library for the standard B1H method and on 6 bp randomized library for the CV-B1H method for which 45 different experimental conditions were tested: five time points and three different IPTG and 3-AT concentrations. We find that GRaMS analysis is robust to the different experimental parameters whereas other analysis methods give widely varying results depending on the conditions of the experiment. Finally, we demonstrate that the CV-B1H assay can be performed in liquid media, which produces recognition models that are similar in quality to sequences recovered from selection on solid media

Putting food in the driver’s seat: aligning food-systems policy to advance sustainability, health, and security

Food is a basic need, but seldom a basic policy area. Food systems are widely governed by disconnected policies distributed across a range of sectors including agriculture, education, health, environment, economy, and security. Failure to align food system strategies often results in these disparate policies operating at cross-purposes. Conventional food production and consumption practices contribute to biodiversity decline and climate change, cause diet-related health problems, are associated with worker exploitation, and create national security risks. Drawing on agroecology for cohesive national food strategies can provide benefits across all these sectors: supporting public health, environmental sustainability, economic stability, social cohesion, and national security and sovereignty

Multilevel Selection in Models of Prebiotic Evolution II: A Direct Comparison of Compartmentalization and Spatial Self-Organization

Multilevel selection has been indicated as an essential factor for the evolution of complexity in interacting RNA-like replicator systems. There are two types of multilevel selection mechanisms: implicit and explicit. For implicit multilevel selection, spatial self-organization of replicator populations has been suggested, which leads to higher level selection among emergent mesoscopic spatial patterns (traveling waves). For explicit multilevel selection, compartmentalization of replicators by vesicles has been suggested, which leads to higher level evolutionary dynamics among explicitly imposed mesoscopic entities (protocells). Historically, these mechanisms have been given separate consideration for the interests on its own. Here, we make a direct comparison between spatial self-organization and compartmentalization in simulated RNA-like replicator systems. Firstly, we show that both mechanisms achieve the macroscopic stability of a replicator system through the evolutionary dynamics on mesoscopic entities that counteract that of microscopic entities. Secondly, we show that a striking difference exists between the two mechanisms regarding their possible influence on the long-term evolutionary dynamics, which happens under an emergent trade-off situation arising from the multilevel selection. The difference is explained in terms of the difference in the stability between self-organized mesoscopic entities and externally imposed mesoscopic entities. Thirdly, we show that a sharp transition happens in the long-term evolutionary dynamics of the compartmentalized system as a function of replicator mutation rate. Fourthly, the results imply that spatial self-organization can allow the evolution of stable folding in parasitic replicators without any specific functionality in the folding itself. Finally, the results are discussed in relation to the experimental synthesis of chemical Darwinian systems and to the multilevel selection theory of evolutionary biology in general. To conclude, novel evolutionary directions can emerge through interactions between the evolutionary dynamics on multiple levels of organization. Different multilevel selection mechanisms can produce a difference in the long-term evolutionary trend of identical microscopic entities

Inflammatory chemokine receptors regulate CD8+ T cell contraction and memory generation following infection

CD8+ T cells lacking CXCR3 and CCR5 expression have impaired contraction and generate an increased number of memory cells after virus infection

Effects of antiplatelet therapy on stroke risk by brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases: subgroup analyses of the RESTART randomised, open-label trial

Background Findings from the RESTART trial suggest that starting antiplatelet therapy might reduce the risk of recurrent symptomatic intracerebral haemorrhage compared with avoiding antiplatelet therapy. Brain imaging features of intracerebral haemorrhage and cerebral small vessel diseases (such as cerebral microbleeds) are associated with greater risks of recurrent intracerebral haemorrhage. We did subgroup analyses of the RESTART trial to explore whether these brain imaging features modify the effects of antiplatelet therapy

The use of chiropractors by older adults in the United States

<p>Abstract</p> <p>Background</p> <p>In a nationally representative sample of United States Medicare beneficiaries, we examined the extent of chiropractic use, factors associated with seeing a chiropractor, and predictors of the volume of chiropractic use among those having seen one.</p> <p>Methods</p> <p>We performed secondary analyses of baseline interview data on 4,310 self-respondents who were 70 years old or older when they first participated in the Survey on Assets and Health Dynamics Among the Oldest Old (AHEAD). The interview data were then linked to their Medicare claims. Multiple logistic and negative binomial regressions were used.</p> <p>Results</p> <p>The average annual rate of chiropractic use was 4.6%. During the four-year period (two years before and two years after each respondent's baseline interview), 10.3% had one or more visits to a chiropractor. African Americans and Hispanics, as well as those with multiple depressive symptoms and those who lived in counties with lower than average supplies of chiropractors were much less likely to use them. The use of chiropractors was much more likely among those who drank alcohol, had arthritis, reported pain, and were able to drive. Chiropractic services did not substitute for physician visits. Among those who had seen a chiropractor, the volume of chiropractic visits was lower for those who lived alone, had lower incomes, and poorer cognitive abilities, while it was greater for the overweight and those with lower body limitations.</p> <p>Conclusion</p> <p>Chiropractic use among older adults is less prevalent than has been consistently reported for the United States as a whole, and is most common among Whites, those reporting pain, and those with geographic, financial, and transportation access.</p

Common genetic variants in the CLDN2 and PRSS1-PRSS2 loci alter risk for alcohol-related and sporadic pancreatitis

Pancreatitis is a complex, progressively destructive inflammatory disorder. Alcohol was long thought to be the primary causative agent, but genetic contributions have been of interest since the discovery that rare PRSS1, CFTR, and SPINK1 variants were associated with pancreatitis risk. We now report two significant genome-wide associations identified and replicated at PRSS1-PRSS2 (1×10-12) and x-linked CLDN2 (p < 1×10-21) through a two-stage genome-wide study (Stage 1, 676 cases and 4507 controls; Stage 2, 910 cases and 4170 controls). The PRSS1 variant affects susceptibility by altering expression of the primary trypsinogen gene. The CLDN2 risk allele is associated with atypical localization of claudin-2 in pancreatic acinar cells. The homozygous (or hemizygous male) CLDN2 genotype confers the greatest risk, and its alleles interact with alcohol consumption to amplify risk. These results could partially explain the high frequency of alcohol-related pancreatitis in men – male hemizygous frequency is 0.26, female homozygote is 0.07