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The arrangements of particles and forces in granular materials have a complex organization on multiple spatial scales that range from local structures to mesoscale and system-wide ones. This multiscale organization can affect how a material responds or reconfigures when exposed to external perturbations or loading. The theoretical study of particle-level, force-chain, domain and bulk properties requires the development and application of appropriate physical, mathematical, statistical and computational frameworks. Traditionally, granular materials have been investigated using particulate or continuum models, each of which tends to be implicitly agnostic to multiscale organization. Recently, tools from network science have emerged as powerful approaches for probing and characterizing heterogeneous architectures across different scales in complex systems, and a diverse set of methods have yielded fascinating insights into granular materials. In this article, we review work on network-based approaches to studying granular matter and explore the potential of such frameworks to provide a useful description of these systems and to enhance understanding of their underlying physics. We also outline a few open questions and highlight particularly promising future directions in the analysis and design of granular matter and other kinds of material networks.

The article reports on a cross-school collaboration which allowed children to create their own virtual neighbourhood called The Street by involving them in a series of literacy based activities. It discusses the key features of the 21st Century Literacies and the focus on the renewed English and Computing curricula, improvements in engagement and motivation, and teaching students wrote digitally and their ownership and investment in the project that added value to the learning.

Optically transparent immersion liquids with refractive index (n∼1.77) to match the sapphire-based aplanatic numerical aperture increasing lens (aNAIL) are necessary for achieving deep 3D imaging with high spatial resolution. We report that antimony tribromide (SbBr_3) salt dissolved in liquid diiodomethane (CH_2I_2) provides a new high refractive index immersion liquid for optics applications. The refractive index is tunable from n=1.74 (pure) to n=1.873 (saturated), by adjusting either salt concentration or temperature; this allows it to match (or even exceed) the refractive index of sapphire. Importantly, the solution gives excellent light transmittance in the ultraviolet to near-infrared range, an improvement over commercially available immersion liquids. This refractive-index-matched immersion liquid formulation has enabled us to develop a sapphire-based aNAIL objective that has both high numerical aperture (NA=1.17) and long working distance (WD=12  mm). This opens up new possibilities for deep 3D imaging with high spatial resolution.

The article offers the author's insights on the photographic learning stories, considering its effectiveness in capturing the learning of children. She says that a photographic learning story presents a series of snapshots of a group of children or a child which are captured while different activities are being executed. She adds that with a photographic learning story, children are able to combine experiences of texts from school and home into their literacy encounters through dramatic play.

Abstract: Observers tend to remember seeing a greater expanse of a scene than was shown (boundary extension [BE]). Is undivided visual attention necessary for BE? In Experiment 1, 108 observers viewed photographs with superimposed numerals (2s and 5s). Each appeared for 750 msec, followed by a masked interval and a test picture (same, closer up, or wider angled). Test pictures were rated as the same, closer, or wider angled on a 5-point scale. Visual attention was manipulated with a search task: The observers reported the number of 5s (zero, one, or two). The observers performed search only, picture rating only, or both (giving search priority). Search accuracy was unaffected by condition. BE occurred in both conditions but was greater with divided attention. The results were replicated using incidental BE tests (Experiments 2 and 3). We propose that anticipatory representation of layout occurs automatically during scene perception, with focal attention serving to constrain the boundary error.

Abstract: Recognition memory is usually regarded as a judgment based on trace strength or familiarity. But recognition may also be accomplished by constraining retrieval so that only sought after information comes to mind (source-constrained retrieval). We introduce amemory-for-foils paradigm that provides evidence for source-constrained retrieval in recognition memory (Experiment 1) and source memory (Experiment 2). In this paradigm, subjects studied words under deep or shallow encoding conditions and were given a memory test (recognition or source) that required them to discriminate between new items (foils) and either deep or shallow targets. A final recognition test was used to examine memory for the foils. In both experiments, foil memory was superior when subjects attempted to retrieve deep rather than shallow targets on the earlier test. These findings support a sourceconstrained retrieval view of cognitive control by demonstrating qualitative differences in the basis for memory performance.

This paper studies the problem of centralized dynamic channel assignment (DCA) in wireless cellular systems under space and time-varying channel demand. The objective is to minimize the number of channels required to satisfy demand while also satisfying co-channel interference constraints. Cumulative co-channel interference constraints govern channel reuse, via a threshold decision criterion based on the carrier-to-interference ratio. The paper makes two contributions. First, it provides an empirical bound on the difference between the minimal number of channels required based only on geographic reuse distance versus the cumulative interference case in the context of linearly increasing demand. The bound is characterized using only the reuse distance. It is obtained with an Integer Programming (IP) based strategy that uses channel assignments for one demand state to assign channels for the next state. Geographic locality constraints are applied to limit reassignments. The impact of cumulative interference constraints is observed to be small for small geographic localities. Second, the paper presents a new, fast DCA heuristic that is based on the characteristic channel reuse patterns used by the IP-based strategy. The heuristic and IP-based method yield similar results for the zero blocking condition. The DCA heuristic is applied to the problem of estimating the blocking probabilities of call arrivals modeled by a two state discrete-time Markov chain and uniformly distributed holding times. The blocking performance for an ensemble of spatial load imbalance distributions is uniquely characterized using the heuristic and IP solutions.

The devastating effects from cardiovascular disease are the largest contributors to employers' health care costs, insurance premiums, disability insurance, and worker's compensation. The purpose of this study was to establish baseline data regarding physiological outcomes comparing two participant groups in a corporate wellness program. Results suggest that a corporate wellness program can be beneficial in assisting employees to improve their health behaviors and outcomes.

Abstract: Subjects read 20 words and generated 20 others from definitions during a 40-item study phase. Production of each word was followed by an instruction to remember or to forget that word. In free recall, a direct test of memory, words that had been generated were recalled much better than words that had been read. The remember-forget instructional manipulation affected read words but not generated words. In speeded word reading, an indirect test of memory, all studied words showed priming, but read words showed more priming than generated words. Here, the effect of remember versus forget instructions appeared only for generated words. These dissociations of a direct and an indirect test indicate that two powerful encoding manipulations affect separable processes to which these tests are differentially sensitive.

Abstract: There are no panaceas and no shortcuts. Man is an amphibious being who lives simultaneously or successively in several universes: in the world of matter, the world of mind, the world of spirit; in the individual world and in the social world; in the homemade universe of his own artifacts, institutions, and imaginings, and in the given, the God-made universe of nature and grace. In the very nature of things none of the major problems confronting such a being can possibly be a simple problem. Those who seek simple solutions for complex problems may have the best of intentions; but unfortunately there is an original sin of the intellect in our habit of arbitrary oversimplification. Those who act without taking precautions against this vice of their intellectual nature doom themselves and their fellows to perpetual disappointment. (Aldous Huxley, 1953, p. 1.)

In acute toxicity tests, green algae Selenastrum capricornutum, diatoms Nitzschia palea, adult snails Physa gyrina, juvenile cladocerans Daphnia magna, larval midges Chironomus tentans, adult amphipods Gammarus minus, juvenile fathead minnows Pimephales promelas, and embryo-larva stages of rainbow trout Salmo gairdneri and largemouth bass Micropterus salmoides were exposed for 4 hours (algae), 48 hours (arthropods and snails), 96 hours (fathead minnows), 7 days (largemouth bass), and 27 days (rainbow trout) to two phenols (phenol and ß-naphthol), two azaarenes (quinoline and acridine), and two polycyclic aromatic hydrocarbons (naphthalene and phenanthrene) present in coal-derived oils. Median lethal or median effective concentrations (LC50s or EC50s) ranged from 0.03 mg/liter for phenanthrene and rainbow trout to 286.54 mg/liter for phenol and the green alga. The rainbow trout embryo-larva assay was the most sensitive of the test systems to all the chemicals except quinoline. For this last compound, systems with juvenile fathead minnows and largemouth bass embryos were the most sensitive. As test systems, fish embryos and larvae were the most sensitive, juvenile fathead minnows and arthropods had intermediate sensitivity, and algae and snails were the most resistant to the test compounds under the test conditions. Within each chemical class (phenols, azaarenes, and polycyclic aromatic hydrocarbons), toxicity increased with increased ring number except for the reversed relationship with the azaarenes and fathead minnows. Thus, ß-naphthol (two rings) was 2 to 45 times more toxic than phenol (one ring); acridine (three rings) was 7 to 27 times more toxic than quinoline (two rings); and phenanthrene (three rings) was 3 to 9 times more toxic than naphthalene (two rings). There was also a relationship between increases in toxicity and increases in the calculated octanol-water partition coefficients of the compounds. Received January 26, 1983 Accepted November 15, 1983

Male, Sprague-Dawley rats were fed l-amino acid diets that contained 0.4% l methionine and either 0, 0.2% (control), or 2.6% l-cysteine (free base) for 5 or 20 days. Hepatic cysteine dioxygenase activity in rats fed 2.6% cysteine was 5 and 3-times as great as in pair-fed control rats at 5 and 20 days, respectively. Cysteine sulfinate decarboxylase activity in liver of rats fed 2.6% cysteine for 20 days was about 40% of the pair-fed control level. The activity of cysteine sulfinate aminotransferase and the rate of cysteine desulfhydration were not influenced by dietary cysteine content. Rats that had been fed these diets for 5 days were intubated with 5 g of diet that contained either 0.2% or 2.6% l-[35S]cysteine. The 24-hour urinary excretion of total 35S, 35SO4, and [35S]taurine by rats that had been fed 2.6% cysteine for 5 days and intubated with 0.2% l-[35S]cysteine was 1.4-, 1.8-, and 2.4-fold, respectively, that of pair-fed control rats. About 2.1, 1.8, and 9.1 times as much 35S, 35SO/4, and [35S]taurine, respectively, were excreted by rats fed 2.6% cysteine for 5 days and intubated with 2.6% l-[35S]cysteine as was excreted by pair-fed control rats. Urinary excretion of these metabolites was not different between rats fed 0 and 0.2% cysteine. These results indicate that the cysteine sulfinate pathway plays a major regulatory role in the metabolism of excess cysteine.

Spatter particles ejected from the melt pool after melting of 316 L stainless steel by laser powder bed fusion additive manufacturing (LPBF), were found to contain morphologies not observed in as-atomized 316 L powder. This spatter consisted of large, spherical particles, highly dendritic surfaces, particles with caps of accreted liquid, and agglomerations of multiple individual particles fixed together by liquid ligaments prior to solidification. The focus of this study is on an additional, unique spatter morphology consisting of larger, spherical particles with surface oxide spots exhibiting a wide distribution of surface configurations, including organized patterning. Spatter particles with organized surface oxide patterns were characterized for surface and internal particle features using multiple imaging techniques. The following observations are made: 1) spots resided at the spatter particle surface and did not significantly penetrate the interior, 2) the spot(s) were amorphous and rich in Silicon (Si)-Manganese (Mn)-Oxygen (O), 3) a two-part Chromium (Cr)-O rich layer exists between the particle and spot, 4) Cr-O rich morphological features were present at the top surface of the spots, 5) the spatter particle composition was consistent with 316 L but appeared to decrease in Si content into the spatter particle away from a spot, and 6) small Si-rich spherical particles existed within the spatter particle interior.

BackgroundMalawi has achieved a remarkable feat in reducing its under-5 mortality in time to meet its MDG 4 target despite high levels of poverty, low female literacy rates, recurrent economic crises, a severe shortage of human resources for health, and poor health infrastructure. The country's community-based delivery platform (largely headed by Health Surveillance Assistants, or HSAs) has been well established since the 1960s, although their tasks and responsibilities have evolved from surveillance to health promotion and prevention, and more recently to include curative services. However, the role of and the form that community involvement takes in community-based service delivery in Malawi is unclear.DesignA qualitative rapid appraisal approach was utilised to explore the role of community involvement in the HSA programme in Malawi to better understand how the various community providers intersect to support the delivery of integrated community case management by HSAs. Twelve focus group discussions and 10 individual interviews were conducted with HSAs, HSA supervisors, mothers, members of village health committees (VHCs), senior Ministry of Health officials, district health teams, and implementing partners.ResultsOur findings reveal that HSAs are often deployed to areas outside of their village of residence as communities are not involved in selecting their own HSAs in Malawi. Despite this lack of involvement in selection, the high acceptance of the HSAs by community members and community accountability structures such as VHCs provide the programme with legitimacy and credibility.ConclusionsThis study provides insight into how community involvement plays out in the context of a government-managed professionalised community service delivery platform. It points to the need for further research to look at the impact of removing the role of HSA selection and deployment from the community and placing it at the central level.

Statistical Analysis for Structure-Activity Relationships. Daniels, K. L., Goyert, J. C, Strand, R. H., and Farrell, M. P. (1983). Fundam. Appl. Toxicol. 3: 350–352. The relationship between organic structure and biological activity (toxicity) is examined by statistically comparing concentration-response regression lines among structurally related compounds. Response data from acute toxicity tests are initially transformed to the logistic function while concentration data are transformed to the logarithm base 10 before being fit to a linear model using a weighted least squares analysis. A sequential approach is presented that uses statistical models for testing differences among related compounds. The approach first tests for the overall equality of regression lines (slopes and intercepts). If the regression lines are found to be different, another set of tests are conducted to determine if the slopes of the lines are equal (i.e. parallel). If the slopes are equal, multiple comparisons are made using Scheffe's procedure for determining which compounds differ in their intercepts. Relative toxicities are then estimated for various concentrations of particular compounds.