Phosphorus and arsenic distributions in a seasonally-stratified, iron- and manganese-rich lake: microbiological and geochemical controls

Seasonal stratification in temperate lakes greater than a few metres deep provides conditions amenable to pronounced vertical zonation of redox chemistry. Such changes are particularly evident in eutrophic systems where high phytoplankton biomass often leads to seasonally-established anoxic hypolimnia and profound changes in geochemical conditions. In this study, we investigated the behaviour of trace elements in the water column of a seasonally-stratified, eutrophic lake. Two consecutive years of data from Lake Ngapouri, North Island, New Zealand, demonstrate the occurrence of highly correlated profiles of phosphorus (P), arsenic (As), iron (Fe) and manganese (Mn), all of which increased in concentration by 1-2 orders of magnitude within the anoxic hypolimnion. Stoichiometric and mass-balance considerations demonstrate that increases in alkalinity in hypolimnetic waters were consistent with observed changes in sulfate, Fe and Mn concentrations with depth, corresponding to dissimilatory reduction of sulfate, Fe(III) and Mn(IV) hydroxides. Thermodynamic constraints on Fe, Mn and Al solubility indicate that amorphous Fe(III), Mn(IV) hydroxides most probably controlled Fe and Mn in the surface mixed layer (~0 to 8 m) while Al(III) hydroxides were supersaturated throughout the entire system. Surface complexation modelling indicated that iron hydroxides (HFO) potentially dominated As speciation in the lake. It is likely that other colloidal phases such as allophanic clays also limited HPO42- activity, reducing competition for HAsO42- adsorption to iron hydroxides. This research highlights the coupling of P, As, Fe and Mn in Lake Ngapouri, and the apparent role of multiple colloidal phases in affecting P and As activity within overarching microbiological and geochemical processes

Attorneys and the California Athlete Agencies Act: The Toll of the Bill

Agents have become a rising force in the sports industry. Their increased role in contract negotiations has brought with it increased scandal. The authors analyze the problems with the regulations promulgated by the various player associations as well as the California Athlete Agencies Act. The authors focus on the efforts of the California Legislature to alleviate these problems by amending the Act with Senate Bill 11 this year. The authors applaud the amendment and state that, with more involvement by the player associations, the sports industry will be much improved

Towards an Adaptive OS Noise Mitigation Technique for Microbenchmarking on Apple Ipad Devices

This study investigates levels of Operating System (OS) noise on Apple iPad mobile devices. OS noise causes variations in application performance that interfere with microbenchmark results. OS noise manifests in collected data through extreme outliers and variations in skewness. Using our collected data, we develop an iterative, semi-automated outlier removal process for Apple iPad OS noise profiles. The profiles generated by outlier removal represent the first step toward an adaptive noise mitigation technique, which presents opportunities for use in microbenchmarking across other mobile platforms

Wellbeing Notebook: Implementing Wellbeing

Early in the naughties (90s) we asked the question \u27How do our client see us?\u27 The answer was clear - as a school that prioritised care and nurture. That gave us an opportunity to buy into that intentionally or try to change that. We decided to buy into that deeply

Who witnesses The Witness? Finding witnesses in The Witness is hard and sometimes impossible

We analyze the computational complexity of the many types of pencil-and-paper-style puzzles featured in the 2016 puzzle video game The Witness. In all puzzles, the goal is to draw a simple path in a rectangular grid graph from a start vertex to a destination vertex. The different puzzle types place different constraints on the path: preventing some edges from being visited (broken edges); forcing some edges or vertices to be visited (hexagons); forcing some cells to have certain numbers of incident path edges (triangles); or forcing the regions formed by the path to be partially monochromatic (squares), have exactly two special cells (stars), or be singly covered by given shapes (polyominoes) and/or negatively counting shapes (antipolyominoes). We show that any one of these clue types (except the first) is enough to make path finding NP-complete ("witnesses exist but are hard to find"), even for rectangular boards. Furthermore, we show that a final clue type (antibody), which necessarily "cancels" the effect of another clue in the same region, makes path finding $\Sigma_2$-complete ("witnesses do not exist"), even with a single antibody (combined with many anti/polyominoes), and the problem gets no harder with many antibodies. On the positive side, we give a polynomial-time algorithm for monomino clues, by reducing to hexagon clues on the boundary of the puzzle, even in the presence of broken edges, and solving "subset Hamiltonian path" for terminals on the boundary of an embedded planar graph in polynomial time.Comment: 72 pages, 59 figures. Revised proof of Lemma 3.5. A short version of this paper appeared at the 9th International Conference on Fun with Algorithms (FUN 2018

To Intervene or not to Intervene:Young adults’ views on When and How to Intervene in Online Harassment

Incidents of online harassment are increasing and can have significant consequences for victims. Witnesses (‘digital bystanders’) can be crucial in identifying and challenging harassment. This study considered when and how young adults intervene online, with the aim of understanding the applicability of existing theoretical models (i.e., Bystander Intervention Model; Response Decision-Making Framework). Thematic analysis of eight focus groups (UK community sample, N=67, 18-25 years) resulted in five themes: Noticing and Interpreting the Harassment, Perceived Responsibility for Helping, Consequences of Intervening, Perceived Ability to Make a Difference, and Deciding How to Help. The online context amplified offline preferences, such as greater preference for anonymity and perceived costs of intervention (e.g., social costs). Intervention strategies varied in visibility and effort, preferring ‘indirect’ micro-interventions focused on supporting victims. A new, merged model specific to digital bystanders is proposed, with implications for the design and messaging on Social Networking Sites (SNS) discussed

Endocrine, transcriptomic and social regulation of division of labor in honey bees

Division of labor is a central facet of complex societies. Task specialization by individual members of the society (theoretically) increases the overall productivity and the fitness of the group. The work presented in this dissertation extends existing knowledge about the regulation of task-related behavioral states at the level of the individual and social group by using the honeybee as a model organism. Chapter 1 reviews the extensive literature regarding the contribution of endocrine signaling (including endocrine-mediated transcriptional cascades) to division of labor in the social Hymenoptera. It also presents a theoretical framework for the evolution of division of labor via the cooption and neofunctionalization of endocrine-mediated signaling and transcription and suggests future lines of research to investigate these phenomena. Chapter 2 investigates the transcriptomic architecture underlying two of the tasks associated with division of labor (broodcare and foraging) using a novel combination of RNA sequencing and informatic analyses. In addition to identifying a key set of transcription factors (TFs) as putative regulators of broodcare or foraging behavior, it presents findings that suggest that coherent modules of coregulated genes are critical for task-related behavioral states. It thereby extends our understanding of how division of labor might be regulated at the transcriptomic level. Chapter 3 probes the regulatory logic underlying this architecture by investigating whether connections between TFs and their targets are labile. Using both bioinformatic analyses and RNAi coupled to behavioral assays and endocrine treatments, it presents significant evidence that the TF-target connectivity can be rewired as a function of behavioral state, social context and neuroendocrine state. This demonstrates how behavioral plasticity related to division of labor can arise at the transcriptomic level. Finally, Chapter 4 links division of labor to social networks involving trophallaxis (exchange of oral secretions and food). It shows that not only are task-related behaviors associated with differences in social interactivity, but that group-level social properties can be altered by hormone treatments that shift division of labor. Chapter 4 also demonstrates that certain emergent properties (such as information flow) are unaffected by such treatments and may represent core features of trophallactic communication in bees. As such, the findings presented in this chapter represent an important first step toward deciphering the role of direct communication in mediating division of labor