Recent studies suggest that meta-learning may provide an original solution to an enduring puzzle about whether neural networks can explain compositionality – in particular, by raising the prospect that compositionality can be understood as an emergent property of an inner-loop learning algorithm. We elaborate on this hypothesis and consider its empirical predictions regarding the neural mechanisms and development of human compositionality.

The Classic Maya polities of Baking Pot and Lower Dover developed along two dramatically different trajectories. At Baking Pot, the capital and associated apical elite regime grew concomitantly with surrounding populations over a thousand-year period. The smaller polity of Lower Dover, in contrast, formed when a Late Classic political center was established by an emergent apical elite regime amidst several long-established intermediate elite-headed districts. The different trajectories through which these polities formed should have clear implications for residential size variability. We employ the Gini coefficient to measure variability in household volume to compare patterns of residential size differentiation between the two polities. The Gini coefficients, while similar, suggest greater differentiation in residential size at Baking Pot than at Lower Dover, likely related to the centralized control of labor by the ruling elite at Baking Pot. While the Gini coefficient is synonymous with measuring wealth inequalities, we suggest that in the Classic period Belize River Valley, residential size was more reflective of labor control.

Recent excavations at the ancient Maya minor center of Tutu Uitz Na in the Belize River Valley revealed an especially large—about 20 million shells—Middle Preclassic (900–300 BC) shell deposit underlying the plaza. Although marine shell species make up a small percentage of the assemblage, most shells are Pachychilus spp., a common freshwater snail known in the southern Maya Lowlands as jute. This report describes the architectural context and assemblage of the deposit and compares it to similar examples in the region. We propose that the Tutu Uitz Na deposit provides one of the earliest examples of depictions of the Maya primordial sea in an architectural context.

Bibliometric methods were used to analyse the major research trends, themes and topics over the last 30 years in the parasitology discipline. The tools used were SciMAT, VOSviewer and SWIFT-Review in conjunction with the parasitology literature contained in the MEDLINE, Web of Science, Scopus and Dimensions databases. The analyses show that the major research themes are dynamic and continually changing with time, although some themes identified based on keywords such as malaria, nematode, epidemiology and phylogeny are consistently referenced over time. We note the major impact of countries like Brazil has had on the literature of parasitology research. The increase in recent times of research productivity on ‘antiparasitics’ is discussed, as well as the change in emphasis on different antiparasitic drugs and insecticides over time. In summary, innovation in parasitology is global, extensive, multidisciplinary, constantly evolving and closely aligned with the availability of technology.

Indicators are necessary to monitor national progress toward commitments made to the Convention on Biological Diversity (CBD), but countries often struggle to mobilize quantitative indicators for many biodiversity targets. Assessing the extent to which countries are using measurable indicators from global and national sources by surveying 5th National Reports to the CBD, we found that nationally generated indicators were used 11 times more frequently than global indicators and only one-fifth of indicators matched those recommended by the CBD, suggesting that countries and indicator experts should work more closely to agree upon measurable, scalable, fit-for-purpose indicators for the next generation of CBD targets.

Objectives: The objective of this study was to evaluate the feasibility and implementation of a standardized medically supervised concussion protocol established between a city-wide AAA hockey league and a multi-disciplinary concussion program. Methods: We conducted a retrospective review of injury surveillance, clinical and healthcare utilization data from all athletes evaluated and managed through the Winnipeg AAA Hockey concussion protocol during the 2016-2017 season. We also conducted post-season email surveys of head coaches and parents responsible for athletes who competed in the same season. Results: During the 2016-2017 season, 28 athletes were evaluated through the medically supervised concussion protocol, with two athletes undergoing evaluation for repeat injuries (a total of 30 suspected injuries and consultations). In all, 96.7% of the athletes managed through the concussion protocol were captured by the league-designated Concussion Protocol Coordinator and 100% of eligible athletes underwent complete medical follow-up and clearance to return to full hockey activities. Although 90% of responding head coaches and 91% of parents were aware of the concussion protocol, survey results suggest that some athletes who sustained suspected concussions were not managed through the protocol. Head coaches and parents also indicated that athlete education and communication between medical and sport stakeholders were other elements of the concussion protocol that could be improved. Conclusion: Successful implementation of a medically supervised concussion protocol for youth hockey requires clear communication between sport stakeholders and timely access to multi-disciplinary experts in traumatic brain and spine injuries. Standardized concussion protocols for youth sports may benefit from periodic evaluations by sport stakeholders and incorporation of national guideline best practices and resources.

Understanding the composition of clay-rich sediments and their transportation into proximal marine basins allows us to better decipher hydroclimatic changes before and within the Palaeocene–Eocene Thermal Maximum (PETM). Only a limited number of such studies exists from the North Sea Basin, which was proximal to the volcanic activity and early rifting hypothesized to have triggered the PETM. The present study examines core material from well 22/10a-4, UK North Sea, as it exhibits an exceptionally expanded and almost stratigraphically complete fine-grained sedimentary sequence suitable for high-resolution analysis.

Quantitative Newmod-for-Windows™-modelled clay mineral assemblages, rather than traditional semi-quantitative estimates, are dominated by smectite-rich, interlayered illite-smectite that probably developed from volcanogenic deposits on continental landmasses. Soil development before the PETM is consistent with the existence of a seasonal tropical climate with a prolonged dry season. A striking rise and fall of kaolinite content within the PETM onset, prior to the principal carbon-isotope excursion, is reported here. This variation is interpreted as a signal of an enhanced hydrologic cycle producing an increase in erosionally derived kaolinite, followed by a dampening of this detrital source as sea-levels rose. Global variations in PETM kaolinite concentrations are consistent with a latitudinal shift in patterns of precipitation in models of global warming.

Purpose: To examine the safety and tolerability of clinical graded aerobic treadmill testing in recovering adolescent moderate and severe traumatic brain injury (TBI) patients referred to a multidisciplinary pediatric concussion program. Methods: We completed a retrospective case series of two moderate and five severe TBI patients (mean age, 17.3 years) who underwent initial Buffalo Concussion Treadmill Testing at a mean time of 71.6 days (range, 55-87) postinjury. Results: Six patients completed one graded aerobic treadmill test each and one patient underwent initial and repeat testing. There were no complications. Five initial treadmill tests were completely tolerated and allowed an accurate assessment of exercise tolerance. Two initial tests were terminated early by the treatment team because of neurological and cardiorespiratory limitations. As a result of testing, two patients were cleared for aerobic exercise as tolerated and four patients were treated with individually tailored submaximal aerobic exercise programs resulting in subjective improvement in residual symptoms and/or exercise tolerance. Repeat treadmill testing in one patient performed after 1 month of treatment with submaximal aerobic exercise prescription was suggestive of improved exercise tolerance. One patient was able to tolerate aerobic exercise following surgery for posterior glottic stenosis. Conclusions: Preliminary results suggest that graded aerobic treadmill testing is a safe, well tolerated, and clinically useful tool to assess exercise tolerance in appropriately selected adolescent patients with TBI. Future prospective studies are needed to evaluate the effect of tailored submaximal aerobic exercise prescription on exercise tolerance and patient outcomes in recovering adolescent moderate and severe TBI patients.

Results from identical experiments conducted at Headland, AL, and Plains, GA, from 1980 through 1982 show insecticide treatment had little effect on soybean [Glycine max (L.) Merr. ‘Coker 237′] growth and morphology. Maximum insecticide applications increased soybean seed weight in two of five trials. Soybeans maintained free of sicklepod (Cassia obtusifolia L. ♯3 CASOB) for 4 weeks after emergence produced yields equal to those receiving season-long control in all trials, and 2-week control was equal to season-long maintenance in three trials. Length of weed interference-free maintenance did not affect soybean height. The number of pods per plant and seed weight were decreased when there was no control. Sicklepod shoot fresh weight and numbers decreased as the weed-free period increased from 0 weeks through the season. Row spacing had no effect on soybean height or seed size; however, the number of pods per plant was higher in 80- than in 40-cm rows. Row spacing influenced yield in only one trial where 20-cm rows outyielded 40-cm rows. A significant interaction occurred between the weed-free period and row spacing in two trials. Soybeans in 20-cm rows outyielded those in 40- and 80-cm rows when sicklepod was not controlled (i.e., 0 weeks interference-free maintenance).

The ability of the Utah energy-balance and snowmelt model (UEB) to simulate decline in snow water equivalent (SWE) at an extreme location was assessed. Field data were collected at Paternoster Valley, Signy Island, South Orkney Islands (60°43′S) during the austral summer of 1996–97. This is the first application of UEB in a maritime Antarctic site. UEB is a physically based snow melt model using a lumped snow-pack representation with primary state variables SWE and snow pack-energy content (U). Meteorological inputs are air temperature, wind speed, humidity, precipitation and total incoming solar and longwave radiation. The Paternoster Valley catchment was subdivided into eight non-contiguous terrain classes for sampling and modelling using a geographical information system (GIS). Simulations of SWE in each of these classes were compared พ with field observations. It is shown that initial U and snow-surface thermal conductance (Ks) affect model simulations. Good approximations of SWE depletion are obtained using measured incoming solar radiation to drive the model but there are shortcomings in the characterization of long wave radiation and sensible-heat fluxes.

The Southern Ocean is the largest of the high-nutrient, low-chlorophyll (HNLC) regions of the world ocean. Phytoplankton production fails to utilise completely the pool of inorganic nutrients in the euphotic zone, giving rise to low phytoplankton bio-mass and leaving relatively high summer nutrient concentrations. This enigma is of considerable significance for our understanding of the role of the oceans in the global carbon cycle. Various limiting factors have been considered: low light, low temperature, absence of necessary trace elements, grazing pressure and other means of biomass removal.

The dynamics of nitrogen uptake by phytoplankton are of particular importance. Classically, nitrate mixed into the surface layer during winter provides the nitrogen pool for growth in the spring bloom. Some organic material is exported to depth, whilst the remainder is recycled, providing ammonium and other reduced species as nitrogenous substrates for growth during the remainder of the season. The oxidation state of the inorganic nitrogen supply thus identifies new and recycled carbon fixation. Whilst this is convenient “shorthand” for the nitrogen nutrition of carbon export in much of the ocean, it is an inappropriate model for the Southern Ocean. Here, nitrate and ammonium use are simultaneous, and nitrate is never exhausted by the annual phytoplankton production.

We speculate that a range of environmental factors combine to make the large pool of nitrate partially inaccessible to phytoplankton. in addition to the documented effects of low iron availability and high ammonium concentrations, the low temperatures characteristic of the Southern Ocean may decrease nitrate availability because of the increased energetic overheads in its uptake and reduction. This in turn makes ammonium an important nitrogenous substrate, and its production by zooplankton and heterotrophic microorganisms is an important component of the plankton nitrogen cycle. There is some evidence that ammonium production by large grazing animals may stimulate phytoplankton growth. Microbial removal of nitrogen from sedimenting phytoplankton cells may result in local decoupling between the carbon and nitrogen cycles, allowing some reduced nitrogen to remain in the euphotic zone whilst carbon is exported to depth.

In this article, we conduct a review of introduced and enacted youth concussion legislation in Canada and present a conceptual framework and recommendations for future youth sport concussion laws. We conducted online searches of federal, provincial, and territorial legislatures to identify youth concussion bills that were introduced or successfully enacted into law. Internet searches were carried out from July 26 and 27, 2016. Online searches identified six youth concussion bills that were introduced in provincial legislatures, including two in Ontario and Nova Scotia and one each in British Columbia and Quebec. One of these bills (Ontario Bill 149, Rowan’s Law Advisory Committee Act, 2016) was enacted into provincial law; it is not actual concussion legislation, but rather a framework for possible enactment of legislation. Two bills have been introduced in federal parliament but neither bill has been enacted into law. At present, there is no provincial or federal concussion legislation that directly legislates concussion education, prevention, management, or policy in youth sports in Canada. The conceptual framework and recommendations presented here should be used to guide the design and implementation of future youth sport concussion laws in Canada.

Objectives: To summarize the clinical characteristics and outcomes of pediatric sports-related concussion (SRC) patients who were evaluated and managed at a multidisciplinary pediatric concussion program and examine the healthcare resources and personnel required to meet the needs of this patient population. Methods: We conducted a retrospective review of all pediatric SRC patients referred to the Pan Am Concussion Program from September 1st, 2013 to May 25th, 2015. Initial assessments and diagnoses were carried out by a single neurosurgeon. Return-to-Play decision-making was carried out by the multidisciplinary team. Results: 604 patients, including 423 pediatric SRC patients were evaluated at the Pan Am Concussion Program during the study period. The mean age of study patients was 14.30 years (SD: 2.32, range 7-19 years); 252 (59.57%) were males. Hockey (182; 43.03%) and soccer (60; 14.18%) were the most commonly played sports at the time of injury. Overall, 294 (69.50%) of SRC patients met the clinical criteria for concussion recovery, while 75 (17.73%) were lost to follow-up, and 53 (12.53%) remained in active treatment at the end of the study period. The median duration of symptoms among the 261 acute SRC patients with complete follow-up was 23 days (IQR: 15, 36). Overall, 25.30% of pediatric SRC patients underwent at least one diagnostic imaging test and 32.62% received referral to another member of our multidisciplinary clinical team. Conclusion: Comprehensive care of pediatric SRC patients requires access to appropriate diagnostic resources and the multidisciplinary collaboration of experts with national and provincially-recognized training in TBI.

The positive effects of dietary fibre on health are now widely recognised; however, our understanding of the mechanisms involved in producing such benefits remains unclear. There are even uncertainties about how dietary fibre in plant foods should be defined and analysed. This review attempts to clarify the confusion regarding the mechanisms of action of dietary fibre and deals with current knowledge on the wide variety of dietary fibre materials, comprising mainly of NSP that are not digested by enzymes of the gastrointestinal (GI) tract. These non-digestible materials range from intact cell walls of plant tissues to individual polysaccharide solutions often used in mechanistic studies. We discuss how the structure and properties of fibre are affected during food processing and how this can impact on nutrient digestibility. Dietary fibre can have multiple effects on GI function, including GI transit time and increased digesta viscosity, thereby affecting flow and mixing behaviour. Moreover, cell wall encapsulation influences macronutrient digestibility through limited access to digestive enzymes and/or substrate and product release. Moreover, encapsulation of starch can limit the extent of gelatinisation during hydrothermal processing of plant foods. Emphasis is placed on the effects of diverse forms of fibre on rates and extents of starch and lipid digestion, and how it is important that a better understanding of such interactions with respect to the physiology and biochemistry of digestion is needed. In conclusion, we point to areas of further investigation that are expected to contribute to realisation of the full potential of dietary fibre on health and well-being of humans.