On covers of cyclic acts over monoids

In (Bull. Lond. Math. Soc. 33:385–390, 2001) Bican, Bashir and Enochs finally solved a long standing conjecture in module theory that all modules over a unitary ring have a flat cover. The only substantial work on covers of acts over monoids seems to be that of Isbell (Semigroup Forum 2:95–118, 1971), Fountain (Proc. Edinb. Math. Soc. (2) 20:87–93, 1976) and Kilp (Semigroup Forum 53:225–229, 1996) who only consider projective covers. To our knowledge the situation for flat covers of acts has not been addressed and this paper is an attempt to initiate such a study. We consider almost exclusively covers of cyclic acts and restrict our attention to strongly flat and condition (P) covers. We give a necessary and sufficient condition for the existence of such covers and for a monoid to have the property that all its cyclic right acts have a strongly flat cover (resp. (P)-cover). We give numerous classes of monoids that satisfy these conditions and we also show that there are monoids that do not satisfy this condition in the strongly flat case. We give a new necessary and sufficient condition for a cyclic act to have a projective cover and provide a new proof of one of Isbell’s classic results concerning projective covers. We show also that condition (P) covers are not unique, unlike the situation for projective covers

Modelling batting expertise from the perspective of high performance coaches

Cricket coaching literature on developing batting expertise has largely focused on the individual, and typically, technical features of batting. Research in cricket batting has addressed developmental factors of expertise (Weissensteiner, et al., 2009) or the perceptual advantage of expert batters (Muller & Abernethy, 2006). Little attention has been paid to the importance of the individual-environment relationship in expert behaviour. In order to address this missing ingredient, one on one, in-depth, semi- structured interviews were undertaken by the primary researcher with eight high performance coaches (e.g., international or state) who were purposely sampled from Cricket Australia or State Cricket associations. Six of these coaches had played international cricket as batsmen, one played state level and one a first grade player. Interviews were transcribed verbatim and coded separately by the first and second author after each interview. The third author then reviewed all codes and provided feedback. Strategies used to enhance validity included; sampling coaches of different high performance levels and retrospective member checking with coaches. Key themes that emerged include expert's superior knowledge of, and attunement to internal (e.g., emotions) and external (e.g. pitch type, field settings) information. This informs their intentions, perceptions and actions to achieve the task goal at any game moment. A skilful batter has time to execute their action and is in ‘rhythm’ with the bowler through attunement to specifying information sources. Experts also adapt to and manipulate the performance environment. Self-evaluative processes, through between-ball routines provide opportunity to reflect, re-evaluate and plan for the next delivery. Examples include; changing stance, forcing field changes or manipulating bowler’s emotions. These results highlight the importance of capturing the experiential knowledge of high performance coaches that cannot be obtained through traditional laboratory based studies. For cricket batting coaches, this work emphasizes the importance of designing learning environments that enable players to better understand their own performance in the context of emergent dynamic game-based constraints

Evaluating a 12-week games-based training program to improve cricket batting skill

Although a constraints-led approach (CLA) to skill acquisition is different from teaching games for understanding (Renshaw et al., 2015), the theoretical underpinnings of CLA can be utilized when designing games-based training approaches. This study examined whether a games-based training design, underpinned by CLA, was more effective at developing cricket batting skill than a more traditional technically focused coaching approach. Sixteen under-15 skilled cricket batters participated in a 12-week intervention study and were randomly allocated to a traditional or experimental training group. The experimental group participated in activities with manipulated rules, equipment, and outcome goals, while the traditional group focused on optimizing technical batting skill processes. Both groups completed two 2-hr sessions per week, bookended by a pre-intervention and post-intervention batting skills test. This test involved facing 18 balls delivered by bowlers, with the number of successful scoring shots, total runs scored, attacking strokes played, and quality of bat–ball contact recorded. An analysis of variance was used to examine between and within-group differences over time. The experimental group (CLA) demonstrated an increased number of successful scoring shots (3.88 vs. 6.63), and increased number of runs scored (11.63 vs. 20.7), and an improvement in the quality of bat–ball contact (1.26 vs. 1.52) after intervention, while there was no change in the number of attacking strokes played (72.37% vs. 74.63%). These numbers were significantly greater than those for the traditional group, which revealed no changes in the number of successful scoring shots played (4.62 vs. 3.75), the number of runs scored (10.25 vs. 10.00), the quality of bat–ball contact (1.26 vs. 1.29), or attacking strokes played (77.78% vs. 78.87%). Skilled U15 players significantly improved facets of their batting using a games-based training approach, while a more traditional training approach did not lead to improvements. Training using a systematic approach to manipulating constraints is suggested to benefit the overall development of a batter

Alternate wet/dry irrigation in rice cultivation: a practical way to save water and control malaria and Japanese encephalitis?

Water management / Water scarcity / Water use efficiency / Water conservation / Irrigated farming / Waterborne diseases / Rice / Malaria / Disease vectors / Productivity / Flood irrigation / Environmental control / Climate / China / East Africa / India / Indonesia / Japan / Philippines / Portugal / USA

Acute hypoxia reduces plasma myostatin independent of hypoxic dose

Background: Muscle atrophy is seen ~ 25 % of patients with cardiopulmonary disorders, such as chronic obstructive pulmonary disorder and chronic heart failure. Multiple hypotheses exist for this loss, including inactivity, inflammation, malnutrition and hypoxia. Healthy individuals exposed to chronic hypobaric hypoxia also show wasting, suggesting hypoxia alone is sufficient to induce atrophy. Myostatin regulates muscle mass and may underlie hypoxic-induced atrophy. Our previous work suggests a decrease in plasma myostatin and increase in muscle myostatin following 10 hours of exposure to 12 % O2. Aims: To establish the effect of hypoxic dose on plasma myostatin concentration. Concentration of plasma myostatin following two doses of normobaric hypoxia (10.7 % and 12.3 % O2) in a randomised, single-blinded crossover design (n = 8 lowlanders, n = 1 Sherpa), with plasma collected pre (0 hours), post (2 hours) and 2 hours following (4 hours) exposure. Results: An effect of time was noted, plasma myostatin decreased at 4 hours but not 2 hours relative to 0 hours (p = 0.01; 0 hours = 3.26 [0.408] ng.mL-1, 2 hours = 3.33, [0.426] ng.mL-1, 4 hours = 2.92, [0.342] ng.mL-1). No difference in plasma myostatin response was seen between hypoxic conditions (10.7 % vs. 12.3 % O2). Myostatin reduction in the Sherpa case study was similar to the lowlander cohort. Conclusions: Decreased myostatin peptide expression suggests hypoxia in isolation is sufficient to challenge muscle homeostasis, independent of confounding factors seen in chronic cardiopulmonary disorders, in a manner consistent with our previous work. Decreased myostatin peptide may represent flux towards peripheral muscle, or a reduction to protect muscle mass. Chronic adaption to hypoxia does not appear to protect against this response, however larger cohorts are needed to confirm this. Future work will examine tissue changes in parallel with systemic effects

The Structure of the Littoral Invertebrate Communities of the Kosciuszko Region Lakes

The littoral macroinvertebrate assemblages of Lakes Albina, Blue, Club andCootapatamba in the Mt. Kosciuszko region were sampled by two methods: sweeps and cobble picks. Thirty-six species were collected with total abundance and species richness greatest in Lake Albina. Common species included themolluscs Pisidium kosciusko and Glacidorbis hedleyi, the crustaceans Metaphreatoicus australis and Neoniphragus n. sp., and an unidentified limnephidtrichoperan. Community structure was influenced by the nature of the substrate, with cobble sites having greater richness and abundance than boulder sites. The importance of the major taxonomic groups (crustaceans, insects and molluscs) varied with sampling method and among lakes. Crustaceans (isopods and amphipods) usually dominated in sweeps, with molluscs and insects varying in importance among lakes, while insects mostly dominated in cobble pick samples. Oligotrophic lakes are typically thought to be dominated by insects, however this study shows such lakes may appear to be dominated by insects or crustaceans depending on the sampling method used and the presence of fish

Long short-term memory language models with additive morphological features for automatic speech recognition

Abstract Models of morphologically rich languages suffer from data sparsity when words are treated as atomic units. Word-based lan-guage models cannot transfer knowledge from common word forms to rarer variant forms. Learning a continuous vector representa-tion of each morpheme allows a compositional model to represent a word as the sum of its constituent morphemes ’ vectors. Rare and unknown words containing common morphemes can thus be repre-sented with greater fidelity despite their sparsity. Our novel neural network language model integrates this additive morphological rep-resentation into a long short-term memory architecture, improving Russian speech recognition word error rates by 0.9 absolute, 4.4% relative, compared to a robust n–gram baseline model. Index Terms — language modeling, neural networks, long short-term memory, compositional morpholog

Excessive iron induces oxidative stress promoting cellular perturbations and insulin secretory dysfunction in MIN6 beta cells

Exposure to high levels of glucose and iron are co-related to reactive oxygen species (ROS) generation and dysregulation of insulin synthesis and secretion, although the precise mechanisms are not well clarified. The focus of this study was to examine the consequences of exposure to high iron levels on MIN6 β-cells. MIN6 pseudoislets were exposed to 20 µM (control) or 100 µM (high) iron at predefined glucose levels (5.5 mM and 11 mM) at various time points (3, 24, 48 & 72 h). Total iron content was estimated by a colourimetric ferrozine assay in presence or absence of transferrin-bound iron. Cell viability was assessed by a resazurin dye-based assay, and ROS mediated cellular oxidative stress was assessed by estimating malondialdehyde levels. β-cell iron absorption was de-termined by a ferritin immunoassay. Cellular insulin release and content was measured by an insu-lin immunoassay. Expression of SNAP-25, a key protein in the core SNARE complex that modulates vesicle exocytosis, was measured by immunoblotting. Our results demonstrate that exposure to high iron levels resulted in a 15-fold (48 h) and 4-fold (72 h) increase in cellular iron accumulation. These observations were consistent with data from oxidative stress analysis which demonstrated 2.69-fold higher levels of lipid peroxidation. Furthermore, exposure to supraphysiological (11 mM) levels of glucose and high iron (100 µM) at 72 h exerted the most detrimental effect on the MIN6 β-cell viability. The effect of high iron exposure on total cellular iron content was identical in the pres-ence or absence of transferrin. High iron exposure (100 µM) resulted in a decrease of MIN6 insulin secretion (64% reduction) as well as cellular insulin content (10% reduction). Finally, a significant reduction in MIN6 β-cell SNAP-25 protein expression was evident at 48 h upon exposure to 100 µM iron. Our data suggest that exposure to high iron and glucose concentrations results in cellular ox-idative damage and may initiate insulin secretory dysfunction in pancreatic β-cells by modulation of the exocytotic machinery