- Abundance and community composition of comammox bacteria in different ecosystems by a universal primer set. [Journal Article]
- STSci Total Environ 2019 Jul 09; 691:146-155
- Complete ammonia oxidizing bacteria (CAOB) have been recognized as a new member of ammonia-oxidizing microorganisms (AOMs) due to its single-step nitrification capability. However, the abundance and …
Complete ammonia oxidizing bacteria (CAOB) have been recognized as a new member of ammonia-oxidizing microorganisms (AOMs) due to its single-step nitrification capability. However, the abundance and diversity of CAOB in environmental ecosystems were still far from known owing to the lack of specific molecular marker. Herein, a universal primer set specifically targeting both clades of CAOB amoA gene with high specificity and coverage was successfully designed. Intriguingly, real-time quantitative PCR tests revealed that CAOB were ubiquitous and unexpectedly abundant in agricultural soils, river sediments, intertidal zones, drinking water and wastewater treatment systems. Phylogenetic analysis indicated that clade A existed in all the five types of ecosystems, while clade B were only detected in soil and sediment samples. Four sub-clusters were further classified within clade A, in which N. nitrosa cluster dominated CAOB amoA in activated sludge samples while the new recognized soil cluster was the primary constitute in soils. Moreover, the niche specialization between different CAOB species and the environmental conditions were supposed to be the primary driven force to shape the diversity and community of CAOB. This study provided a strong evidence in support of the ubiquities and high abundances of CAOB in various environmental ecosystems and highlighted the significance of including CAOB as the new member of AOMs to re-evaluate the biogeochemical nitrogen cycle.
- The impact of three types of writing intervention on students' writing quality. [Journal Article]
- PlosPLoS One 2019; 14(7):e0218099
- Students' writing constitutes a topic of major concern due to its importance in school and in daily life. To mitigate students' writing problems, school-based interventions have been implemented in t…
Students' writing constitutes a topic of major concern due to its importance in school and in daily life. To mitigate students' writing problems, school-based interventions have been implemented in the past, but there is still a need to examine the effectiveness of different types of writing interventions that use robust design methodologies. Hence, the present study followed a longitudinal cluster-randomized controlled design using a multilevel modeling analysis with 370 fourth-grade students (nested in 20 classes). The classes were randomly assigned to four conditions: one comparison group and three writing types of writing interventions (i.e., week-journals, Self-Regulation Strategy Development (SRSD) instruction and SRSD plus Self-Regulated Learning (SRL) program using a story-tool), with five classes participating in each condition. Data supports our hypothesis by showing differences between the treatment groups in students' writing quality over time. Globally, the improvement of students' writing quality throughout time is related to the level of specialization of the writing interventions implemented. This is an important finding with strong implications for educational practice. Week-journals and writing activities can be easily implemented in classrooms and provides an opportunity to promote students' writing quality. Still, students who participated in the instructional programs (i.e., SRSD and SRSD plus story-tool) exhibited higher writing quality than the students who wrote week-journals. Current data did not find statistical significant differences between results from the two instructional writing tools.
- Playing out Liem's Paradox: Opportunistic Piscivory across Lake Tanganyikan Cichlids. [Journal Article]
- ANAm Nat 2019; 194(2):260-267
- Trophic specialization is a key feature of the diversity of cichlid fish adaptive radiations. However, K. F. Liem observed that even species with highly specialized trophic morphologies have dietary …
Trophic specialization is a key feature of the diversity of cichlid fish adaptive radiations. However, K. F. Liem observed that even species with highly specialized trophic morphologies have dietary flexibility, enabling them to exploit episodic food resources opportunistically. Evidence for dietary flexibility comes largely from laboratory studies, and it is unclear whether cichlid fishes undergo diet shifts in the wild. We report observations of diet switching by multiple cichlid species in Lake Tanganyika as a consequence of unusual concentrations of schooling juvenile clupeid fishes. Fish species with varying degrees of trophic specialization converged on a single prey: juvenile sardines that are also endemic to Lake Tanganyika (Stolothrissa tanganicae and Limnothrissa miodon). We provide evidence for cichlid species acting as jacks-of-all-trades and discuss this evidence in the framework of Liem's classic paradox: that trophic specialization does not preclude dietary flexibility.
- The materials of mastication: material science of the humble tooth. [Journal Article]
- ICIntegr Comp Biol 2019 Jul 18
- Dental functional morphology, as a field, represents a confluence of materials science and biology. Modern methods in materials testing have been influential in driving the understanding of dental ti…
Dental functional morphology, as a field, represents a confluence of materials science and biology. Modern methods in materials testing have been influential in driving the understanding of dental tissues and tooth functionality. Here we present a review of dental enamel, the outermost tissue of teeth. Enamel is the hardest biological tissue and exhibits remarkable resilience even when faced with a variety mechanical threats. In the light of recent work, we progress the argument that the risk of mechanical degradation across multiple scales exhibits a strong and continued selection pressure on structural organization of enamel. The hierarchical nature of enamel structure presents a range of scale-dependent toughening mechanisms and provides a means by which natural selection can drive the specialization of this tissue from nanoscale reorganization to whole tooth morphology. There has been much learnt about the biomechanics of enamel recently, yet our understanding of the taxonomic diversity of this tissue is still lacking and may form an interesting avenue for future research.
- Lower Extremity Biomechanics Are Altered Across Maturation in Sport-Specialized Female Adolescent Athletes. [Journal Article]
- FPFront Pediatr 2019; 7:268
- Sport specialization is a growing trend in youth athletes and may contribute to increased injury risk. The neuromuscular deficits that often manifest during maturation in young, female athletes may b…
Sport specialization is a growing trend in youth athletes and may contribute to increased injury risk. The neuromuscular deficits that often manifest during maturation in young, female athletes may be exacerbated in athletes who specialize in a single sport. The purpose of this study was to investigate if sport specialization is associated with increased lower extremity biomechanical deficits pre- to post-puberty in adolescent female athletes. Seventy-nine sport-specialized female adolescent (Mean ± SD age = 13.4 ± 1.8 years) basketball, soccer, and volleyball athletes were identified and matched with seventy-nine multi-sport (soccer, basketball, and volleyball) female athletes from a database of 1,116 female adolescent basketball, soccer, and volleyball athletes who were enrolled in one of two large prospective, longitudinal studies. The athletes were assessed over two visits (Mean ± SD time = 724.5 ± 388.7 days) in which they were classified as pre-pubertal and post-pubertal, respectively. Separate 2 × 2 analyses of covariance were used to compare sport-specialized and multi-sport groups and dominant/non-dominant limbs with respect to pubertal changes in peak knee sagittal, frontal, and transverse plane joint angular measures and moments of force recorded while performing a drop vertical jump task. The sport-specialized group were found to exhibit significantly larger post-pubertal increases in peak knee abduction angle (p = 0.005) and knee abduction moment (p = 0.006), as well as a smaller increase in peak knee extensor moment (p = 0.032) during landing when compared to the multi-sport group. These biomechanical changes are indicative of potentially compromised neuromuscular control that may increase injury risk pre- to post-puberty in sport-specialized female athletes. Consideration of maturation status may be an important factor in assessing the injury risk profiles of adolescent athletes who specialize in sport.
- Trait-based plant ecology a flawed tool in climate studies? The leaf traits of wild olive that pattern with climate are not those routinely measured. [Journal Article]
- PlosPLoS One 2019; 14(7):e0219908
- Climate-related studies have generally focussed upon physiologically well-defined 'mechanistic' traits rather than 'functional' ones relating indirectly to resource capture. Nevertheless, field respo…
Climate-related studies have generally focussed upon physiologically well-defined 'mechanistic' traits rather than 'functional' ones relating indirectly to resource capture. Nevertheless, field responses to climate are likely to typically include both 'mechanistic' specialization to climatic extremes and 'functional' strategies that optimize resource acquisition during less climatically-severe periods. Here, this hypothesis was tested. Seventeen traits (six 'functional', six 'mechanistic' and five 'intermediate') were measured from 19 populations of oleaster (wild olive) along a climatic gradient in Morocco. Principal components analysis of the trait dataset identified size and the 'worldwide leaf economics spectrum' as PCA axes 1 and 2. However, contrary to our prediction, these axes, and commonly-measured 'functional' traits, were little correlated with climate. Instead, PCA 3, perhaps relating to water-use and succulence, together stomatal density, specific leaf water content and leaf shape, patterned with altitude, aridity, rainfall and temperature. We concluded that, at least for slow-growing species, such as oleaster, 'mechanistic' traits are key to identifying mechanisms of climatic restriction. Meaningful collaboration between 'mechanistic' and 'functional' disciplines provides the best way of improving our understanding of the global impacts of climate change on species distribution and performance.
- [Performance of medical schools in Mexico: Results from the Examen Nacional para Aspirantes a Residencias Médicas]. [Journal Article]
- SPSalud Publica Mex 2019 Jul 17
- CONCLUSIONS: The ENARM results provide information on the performance of the FEM. Approximately one of every four applicants obtained scores lower than the approval threshold of any specialty.
- The development of Singapore nursing education system - challenges, opportunities and implications. [Journal Article]
- INInt Nurs Rev 2019 Jul 17
- CONCLUSIONS: There are three main challenges and opportunities for nursing education in Singapore: (1) the establishment of registered nurse preparatory education at the baccalaureate level, (2) the expansion of master's programmes for clinical specialization and (3) the need to increase nursing faculties through the growth of doctoral education.Singapore's nursing education has made a significant progress in its development since the 1990s. To advance nursing education, individual nurses, local nursing associations and academic institutions should be empowered to develop its own clinical, education and research capabilities to meet future healthcare challenges.
- Discovering Conserved Properties of Brain Organization Through Multimodal Integration and Interspecies Comparison. [Comment]
- JEJ Exp Neurosci 2019; 13:1179069519862047
- The primate cerebral cortex is broadly organized along hierarchical processing streams underpinned by corresponding variation in the brain's microstructure and interareal connectivity patterns. Fulch…
The primate cerebral cortex is broadly organized along hierarchical processing streams underpinned by corresponding variation in the brain's microstructure and interareal connectivity patterns. Fulcher et al. recently demonstrated that a similar organization exists in the mouse cortex by combining independent datasets of cytoarchitecture, gene expression, cell densities, and long-range axonal connectivity. Using the T1w:T2w magnetic resonance imaging map as a common spatial reference for data-driven comparison of cortical gradients between mouse and human, we highlighted a common hierarchical expression pattern of numerous brain-related genes, providing new understanding of how systematic structural variation shapes functional specialization in mammalian brains. Reflecting on these findings, here we discuss how open neuroscience datasets, combined with advanced neuroinformatics approaches, will be crucial in the ongoing search for organization principles of brain structure. We explore the promises and challenges of integrative studies and argue that a tighter collaboration between experimental, statistical, and theoretical neuroscientists is needed to drive progress further.
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- Enhancing nutrient recycling from excreta to meet crop nutrient needs in Sweden - a spatial analysis. [Journal Article]
- SRSci Rep 2019 Jul 16; 9(1):10264
- Increased recycling of nutrient-rich organic waste to meet crop nutrient needs is an essential component of a more sustainable food system. However, agricultural specialization continues to pose a si…
Increased recycling of nutrient-rich organic waste to meet crop nutrient needs is an essential component of a more sustainable food system. However, agricultural specialization continues to pose a significant challenge to balancing crop nutrient needs and the nutrient supply from animal manure and human excreta locally. For Sweden, this study found that recycling all excreta (in 2007) could meet up to 75% of crop nitrogen and 81% of phosphorus needs, but that this would exceed crop potassium needs by 51%. Recycling excreta within municipalities could meet 63% of crop P nutrient needs, but large regional differences and imbalances need to be corrected to avoid over or under fertilizing. Over 50% of the total nitrogen and phosphorus in excreta is contained in just 40% of municipalities, and those have a surplus of excreta nutrients compared to crop needs. Reallocation of surpluses (nationally optimized for phosphorus) towards deficit municipalities, would cost 192 million USD (for 24 079 km of truck travel). This is 3.7 times more than the total NPK fertilizer value being transported. These results indicate that Sweden could reduce its dependence on synthetic fertilizers through investments in excreta recycling, but this would likely require valuing also other recycling benefits.