Impact of Irrigation Applications at Soil Moisture Deficits on Plant Development and Yield of Indeterminate and Determinate Soybean Varieties

As the Mississippi River Alluvial Aquifer declines, it is the duty of soybean producers to become more efficient irrigators. Research was established in 2012 and 2013 in the Mississippi Delta to evaluate plant development and yield of an indeterminate soybean variety with irrigation initiated at the R1 producer standard and compared to initiation timings at the R2, R4, and R5 growth stages once a 2” deficit was reached according to the FAO-56 Penman-Monteith model. Research was also conducted to evaluate seeding rates in irrigated and non-irrigated systems in Starkville and Stoneville, MS in 2013 and 2014. These data indicate that delaying irrigation initiation beyond R1 did not adversely affect yield, and in some instances even provided a small yield increase. Irrigation did show consistent yield benefit regardless of initiation timing over a non-irrigated system. No optimum seeding rate in terms of yield or net return was observed across site years

High-aluminum-affinity silica is a nanoparticle that seeds secondary aluminosilicate formation.

Despite the importance and abundance of aluminosilicates throughout our natural surroundings, their formation at neutral pH is, surprisingly, a matter of considerable debate. From our experiments in dilute aluminum and silica containing solutions (pH ~ 7) we previously identified a silica polymer with an extraordinarily high affinity for aluminium ions (high-aluminum-affinity silica polymer, HSP). Here, further characterization shows that HSP is a colloid of approximately 2.4 nm in diameter with a mean specific surface area of about 1,000 m(2) g(-1) and it competes effectively with transferrin for Al(III) binding. Aluminum binding to HSP strongly inhibited its decomposition whilst the reaction rate constant for the formation of the β-silicomolybdic acid complex indicated a diameter between 3.6 and 4.1 nm for these aluminum-containing nanoparticles. Similarly, high resolution microscopic analysis of the air dried aluminum-containing silica colloid solution revealed 3.9 ± 1.3 nm sized crystalline Al-rich silica nanoparticles (ASP) with an estimated Al:Si ratio of between 2 and 3 which is close to the range of secondary aluminosilicates such as imogolite. Thus the high-aluminum-affinity silica polymer is a nanoparticle that seeds early aluminosilicate formation through highly competitive binding of Al(III) ions. In niche environments, especially in vivo, this may serve as an alternative mechanism to polyhydroxy Al(III) species binding monomeric silica to form early phase, non-toxic aluminosilicates

Resilience, mental health and urban migrants: a narrative review

The file attached to this record is the author's final peer reviewed version. The Publisher's final version can be found by following the DOI link.The purpose of this paper is to provide a narrative review of the literature on mental health resilience and other positive mental health capacities of urban and internal migrants. The methodology for this narrative review included a search of articles published up to 2017. The abstracts were screened and relevant articles studied and discussed. Literature on the particular mental health challenges of urban migrants in India was also studied. References found in the literature relating to neuro-urbanism were also followed up to explore broader historical and conceptual contexts. Several key sources and resources for mental health resilience were identified – including familial and community networks and individual hope or optimism. Nevertheless, much of the literature tends to focus at the level of the individual person, even though ecological systems theory would suggest that mental health resilience is better understood as multi-layered i.e. relevant to, and impacted by, communities and broader societal and environmental contexts. This paper provides insight into an aspect of migrant mental health that has tended to be overlooked hitherto: the mental health resilience and positive mental health capacities of urban migrants. This is particularly relevant where professional ‘expert’ mental health provision for internal migrant communities is absent or unaffordable. Previous work has tended to focus predominantly on mental health risk factors, despite growing awareness that focusing on risk factors along can lead to an over-reliance on top-down expert-led interventions and overlook positive capacities for mental health that are sometimes possessed by individuals and their communities

Genotoxic capacity of Cd/Se semiconductor quantum dots with differing surface chemistries.

Quantum dots (QD) have unique electronic and optical properties promoting biotechnological advances. However, our understanding of the toxicological structure-activity relationships remains limited. This study aimed to determine the biological impact of varying nanomaterial surface chemistry by assessing the interaction of QD with either a negative (carboxyl), neutral (hexadecylamine; HDA) or positive (amine) polymer coating with human lymphoblastoid TK6 cells. Following QD physico-chemical characterisation, cellular uptake was quantified by optical and electron microscopy. Cytotoxicity was evaluated and genotoxicity was characterised using the micronucleus assay (gross chromosomal damage) and the HPRT forward mutation assay (point mutagenicity). Cellular damage mechanisms were also explored, focusing on oxidative stress and mitochondrial damage. Cell uptake, cytotoxicity and genotoxicity were found to be dependent on QD surface chemistry. Carboxyl-QD demonstrated the smallest agglomerate size and greatest cellular uptake, which correlated with a dose dependent increase in cytotoxicity and genotoxicity. Amine-QD induced minimal cellular damage, while HDA-QD promoted substantial induction of cell death and genotoxicity. However, HDA-QD were not internalised by the cells and the damage they caused was most likely due to free cadmium release caused by QD dissolution. Oxidative stress and induced mitochondrial reactive oxygen species were only partially associated with cytotoxicity and genotoxicity induced by the QD, hence were not the only mechanisms of importance. Colloidal stability, nanoparticle (NP) surface chemistry, cellular uptake levels and the intrinsic characteristics of the NPs are therefore critical parameters impacting genotoxicity induced by QD

Geometrical Finiteness, Holography, and the BTZ Black Hole

We show how a theorem of Sullivan provides a precise mathematical statement of a 3d holographic principle, that is, the hyperbolic structure of a certain class of 3d manifolds is completely determined in terms of the corresponding Teichmuller space of the boundary. We explore the consequences of this theorem in the context of the Euclidean BTZ black hole in three dimensions.Comment: 6 pages, Latex, Version to appear in Physical Review Letter

Prospectus, October 22, 1986

https://spark.parkland.edu/prospectus_1986/1026/thumbnail.jp

Cell type-dependent changes in CdSe/ZnS quantum dot uptake and toxic endpoints.

Toxicity of nanoparticles (NPs) is often correlated with the physicochemical characteristics of the materials. However, some discrepancies are noted in in-vitro studies on quantum dots (QDs) with similar physicochemical properties. This is partly related to variations in cell type. In this study, we show that epithelial (BEAS-2B), fibroblast (HFF-1), and lymphoblastoid (TK6) cells show different biological responses following exposure to QDs. These cells represented the 3 main portals of NP exposure: bronchial, skin, and circulatory. The uptake and toxicity of negatively and positively charged CdSe:ZnS QDs of the same core size but with different surface chemistries (carboxyl or amine polymer coatings) were investigated in full and reduced serum containing media following 1 and 3 cell cycles. Following thorough physicochemical characterization, cellular uptake, cytotoxicity, and gross chromosomal damage were measured. Cellular damage mechanisms in the form of reactive oxygen species and the expression of inflammatory cytokines IL-8 and TNF-α were assessed. QDs uptake and toxicity significantly varied in the different cell lines. BEAS-2B cells demonstrated the highest level of QDs uptake yet displayed a strong resilience with minimal genotoxicity following exposure to these NPs. In contrast, HFF-1 and TK6 cells were more susceptible to toxicity and genotoxicity, respectively, as a result of exposure to QDs. Thus, this study demonstrates that in addition to nanomaterial physicochemical characterization, a clear understanding of cell type-dependent variation in uptake coupled to the inherently different capacities of the cell types to cope with exposure to these exogenous materials are all required to predict genotoxicity

A British university case study of the transitional experiences of student-athletes

OBJECTIVES. Within Great Britain, increasing numbers of elite sport performers are attending higher education institutions. The current study presents an exploration of the transitional experiences of these individuals at a specific British university. Wylleman and Lavallee's (2004) developmental model on transitions faced by athletes and Stambulova's (1997, 2003) athletic career transition model were used to provide the theoretical foundation of inquiry. DESIGN AND METHOD. An instrumental case study design was adopted to provide an in-depth analysis of student-athletes’ experiences at a university. The case university was selected based on its provision of elite sport support services. To acquire a holistic understanding, interviews were conducted with current and recently graduated student-athletes from the university, and focus groups were run with university staff (viz. administrators, coaches, and support staff). Qualitative data were analyzed using a thematic framework approach. RESULTS. Elite student-athletes at the British university were found to experience simultaneous athletic, academic, psychological, and psychosocial transitions. To overcome the transitional demands, student-athletes were found to draw on a variety of internal (e.g., self-awareness) and external (e.g., academic flexibility) resources and to implement coping strategies (e.g., seeking social support). Potential barriers to successful transitions were also identified (e.g., parental overprotection). CONCLUSIONS. These findings advance the limited existing literature on British university student-athletes’ transitional experiences and suggestions are provided for how other universities can enhance provision for their elite student-athletes