Sweet Corn Plastic Mulch Comparison

Early sweet corn production is enhanced by use of clear plastic mulch. Some growers use this practice on their earliest plantings to gain a market advantage and higher price. In cool, wet springs the practice is highly profitable. In central and northern Iowa, the years with a yield advantage more than offset the costs for years with no gain. There are many color plastic choices with various advertised benefits such as increased soil temperature and reflective radiation that speeds plant growth and development. The sweet corn research is designed to evaluate a few color mulches that are reported to affect corn growth and development—specifically, the sugar content of the kernel at harvest. The blue is supposed to enhance photosynthesis and improve translocation of carbohydrates (sucrose) to the developing kernel. As sweet corn is harvested in the immature stage (as opposed to field corn) it is thought there might be a sugar boost (some Canadian work was indecisive). The mulches were manufactured using pigment resins of a proprietary nature that change the wavelength of reflective radiation – blue and red. Thus, we measured the reflective radiation to see if that is true. Some plastics are included that affect soil temperature more than reflective radiation (i.e, the olive and clear). Increasing soil temperature and resultant enhanced shoot growth and leaf surface area may have more to do with photosynthesis and sugar production than specific reflective radiation

Creating a microcosm to examine salinity tolerance of \u3cem\u3eEscherichia coli\u3cem\u3e in beach sand

Escherichia coli (E. coli) is a gram-negative bacteria species that thrives in a variety of environments around the world. Due to its widespread prevalence, it is commonly used as an indicator for fecal pollution and other pathogens. One place where it is not often looked for is oceanic beaches because E. coli is inhibited by salt. However, recent research has shown that E. coli often thrives in sand at many oceanic beaches. To determine how it persists in sand, we created a microcosm simulating the intertidal zone of an oceanic beach. Using this microcosm, we examined how varying levels of salinity (0-6%) affect the persistence of E. coli in these sandy environments. We found that there was a negative correlation between increasing salinity and the most probable number of E. coli colony forming units, which suggests that E. coli is being inhibited by salinity to a degree. However, we still found that E. coli was able to persist at all salt concentrations including those that exceed normal oceanic salinity. Collectively, our findings suggest that E. coli may be able to persist on sandy beaches despite the stress of salinity and may be a useful tool in the future for assessing thes

Determination of phylo-group diversity of \u3cem\u3eEscherichia coli\u3c/em\u3e in environmental sand samples collected from a South Carolina beach

Escherichia coli (E. coli) is a common bacterial species that can persist in many environments found around the world. One environment where it can be found that is of particular concern is an oceanic beach, where it can serve as an indicator of both fecal and microbial pollution. While the majority of strains of E. coli are non-pathogenic to humans, some phylo-groups are associated with virulent strains and could cause disease. Therefore, it is of critical concern that we determine where this E. coli is coming from and whether it is potentially harmful to human health and well-being. In this study, we attempted to answer this question by using a newly developed molecular technique, which allows us to identify which phylo-groups environmental isolates of E. coli belong to. Classification into phylo-groups can help infer the source of the pollution. For this analysis, we collected sand samples from Folly Beach, SC, which is one of the most visited beaches in the Southeastern US. In our analysis, we identified environmental isolates of E. coli that differ from the lab strain and belong to two distinct phylo-groups including phylo-group A, which is likely from human fecal contamination and phylo-group B1, which is likely from a domesticated and/or wild animal source. The same molecular technique was altered to test for virulence factors of E. coli, and all isolates showed a band corresponding to a virulence factor, but further analysis is needed to determine the validity of this technique. Collectively, our findings indicate that multiple types of E. coli are able to persist in these environments and that more research is needed to determine whether these strains are of public health concern

A Source for Feature-Based Attention in the Prefrontal Cortex

In cluttered scenes, we can use feature-based attention to quickly locate a target object. To understand how feature attention is used to find and select objects for action, we focused on the ventral prearcuate (VPA) region of prefrontal cortex. In a visual search task, VPA cells responded selectively to search cues, maintained their feature selectivity throughout the delay and subsequent saccades, and discriminated the search target in their receptive fields with a time course earlier than in FEF or IT cortex. Inactivation of VPA impaired the animals' ability to find targets, and simultaneous recordings in FEF revealed that the effects of feature attention were eliminated while leaving the effects of spatial attention in FEF intact. Altogether, the results suggest that VPA neurons compute the locations of objects with the features sought and send this information to FEF to guide eye movements to those relevant stimuli.National Eye Institute (Grant EY017921)National Science Foundation (U.S.) (Grant CCF 1317348

Childhood adversity and parent perceptions of child resilience

Abstract Background Adverse childhood experiences (ACEs) negatively impact health throughout the life course. For children exposed to ACEs, resilience may be particularly important. However, the literature regarding resilience, particularly the self-regulation aspect of resilience, is not often described in children with ACEs. Additionally, family and community factors that might help promote resilience in childhood may be further elucidated. We aimed to describe the relationship between ACEs and parent-perceived resilience in children and examine the child, family, and community-level factors associated with child resilience. Methods Using the US-based, 2011–2012 National Survey of Children’s Health, we examined adverse childhood experiences (NSCH-ACEs) as the main exposure. Affirmative answers to adverse experiences generated a total parent-reported NSCH-ACE score. Bivariate and multivariable logistic regression models were constructed for parent-perceived child resilience and its association with ACEs, controlling for child, family, and neighborhood-level factors. Results Among 62,200 US children 6–17 years old, 47% had 0 ACEs, 26% had 1 ACE, 19% had 2–3 ACEs, and 8% had 4 or more ACEs. Child resilience was associated with ACEs in a dose-dependent relationship: as ACEs increased, the probability of resilience decreased. This relationship persisted after controlling for child, family, and community factors. Specific community factors, such as neighborhood safety (p < .001), neighborhood amenities (e.g., libraries, parks) (p < .01) and mentorship (p < .05), were associated with significantly higher adjusted probabilities of resilience, when compared to peers without these specific community factors. Conclusions While ACEs are common and may be difficult to prevent, there may be opportunities for health care providers, child welfare professionals, and policymakers to strengthen children and families by supporting community-based activities, programs, and policies that promote resilience in vulnerable children and communities in which they live.https://deepblue.lib.umich.edu/bitstream/2027.42/144527/1/12887_2018_Article_1170.pd

A Source for Feature-Based Attention in the Prefrontal Cortex

SummaryIn cluttered scenes, we can use feature-based attention to quickly locate a target object. To understand how feature attention is used to find and select objects for action, we focused on the ventral prearcuate (VPA) region of prefrontal cortex. In a visual search task, VPA cells responded selectively to search cues, maintained their feature selectivity throughout the delay and subsequent saccades, and discriminated the search target in their receptive fields with a time course earlier than in FEF or IT cortex. Inactivation of VPA impaired the animals’ ability to find targets, and simultaneous recordings in FEF revealed that the effects of feature attention were eliminated while leaving the effects of spatial attention in FEF intact. Altogether, the results suggest that VPA neurons compute the locations of objects with the features sought and send this information to FEF to guide eye movements to those relevant stimuli

Network size, structure and mutualism dependence affect the propensity for plant-pollinator extinction cascades

1. Pollinator network structure arising from the extent and strength of interspecific mutualistic interactions can promote species persistence and community robustness. However, environmental change may re-organise network structure limiting capacity to absorb or resist shocks and increasing species extinctions. 2. We investigated if habitat disturbance and the level of mutualism dependence between species affected the robustness of insect–flower visitation networks Following a recently developed Stochastic Co-extinction Model (SCM), we ran simulations to produce the number of extinction episodes (cascade degree), which we correlated with network structure in undisturbed and disturbed habitat. We also explicitly modelled whether a species’ intrinsic dependence on mutualism affected the propensity for extinction cascades in the network. 3. Habitat disturbance generated a gradient in network structure with those from disturbed sites being less connected, but more speciose and so larger. Controlling for network size (z-score standardisation against the null model) revealed that disturbed networks had disproportionately low linkage density, high specialisation, fewer insect visitors per plant species (vulnerability) and lower nestedness (NODF). 4. This network structure gradient driven by disturbance increased and decreased different aspects of robustness to simulated plant extinction. Disturbance decreased the risk that an initial insect extinction would follow a plant species loss. Although, this effect disappeared when network size and connectance were standardised, suggesting the lower connectance of disturbed networks increased robustness to an initial secondary extinction. 5. However, if a secondary extinction occurred then networks from disturbed habitat were more prone to large co-extinction cascades, likely resulting from a greater chance of extinction in these larger, speciose networks. Conversely, when species mutualism dependency was explicit in the SCM simulations the disturbed networks were disproportionately more robust to very large co-extinction cascades, potentially caused by non-random patterns of interaction between species differing in dependence on mutualism. 6. Our results showed disturbance altered the size and the distribution of interspecific interactions in the networks to affect their robustness to co-extinction cascades. Controlling for effects due to network size and the interspecific variation in demographic dependence on mutualism can improve insight into properties conferring the structural robustness of networks to environmental changes

An investigation of polymorphisms in the 17q11.2-12 CC chemokine gene cluster for association with multiple sclerosis in Australians

BACKGROUND: Multiple sclerosis (MS) is a disorder of the central nervous system (CNS) characterised by inflammation and neuronal degeneration. It is believed to result from the complex interaction of a number of genes, each with modest effect. Chemokines are vital to the migration of cells to sites of inflammation, including the CNS, and many are implicated in MS pathogenesis. Most of the CC chemokine genes are encoded in a cluster on chromosome 17q11.2-12, which has been identified in a number of genome wide screens as being potentially associated with MS. METHODS: We conducted a two-stage analysis to investigate the chemokine gene cluster for association with MS. After sequencing the chemokine genes in several DNA pools to identify common polymorphisms, 12 candidate single-nucleotide polymorphisms (SNPs) were genotyped in a cohort of Australian MS trio families. RESULTS: Marginally significant (uncorrected) transmission distortion was identified for four of the SNPs after stratification for several factors. We also identified marginally significant (uncorrected) transmission distortion for haplotypes encompassing the CCL2 and CCL11 genes, using two independent cohorts, which was consistent with recent reports from another group. CONCLUSION: Our results implicate several chemokines as possibly being associated with MS susceptibility, and given that chemokines and their receptors are suitable targets for therapeutic agents, further investigation is warranted in this region