SPATIAL COMPARISONS OF POPULATIONS OF AN INDIGENOUS LIMPET SCUTELLASTRA ARGENVILLEI AND AN ALIEN MUSSEL MYTILUS GALLOPROVINCIALIS ALONG A GRADIENT OF WAVE ENERGY

In the 1970s, the Mediterranean mussel Mytilus galloprovincialis invaded the South African coast and spread rapidly to dominate much of the West Coast, indicating either the opportunity to occupy a vacant niche or its superior competitive capability over indigenous species. In Namaqualand on the West Coast it appears to compete with a large indigenous limpet, Scutellastra argenvillei, which is capable of forming dense, almost monospecific stands low on the shore. A survey on the Namaqualand coast indicated that the abundance of M. galloprovincialis changes with wave exposure. At wave-exposed locations, the mussel covered up to 90&#37 of the primary substratum, whereas in semi-exposed situations it was never abundant. As the cover of M. galloprovincialis increased, the abundance and size of S. argenvillei on rock declined and it became confined to patches within a matrix of mussel bed. Both species were absent from sheltered shores and diminished where wave action was extreme. Comparisons with previous surveys indicated that exposed sites now largely covered by the alien mussel were once dominated by dense populations of the limpet. Therefore, the results of this survey provide circumstantial correlative evidence of a competitive interaction between M. galloprovincialis and S. argenvillei, and suggest that wave action mediates the strength of this interaction. The presence of mussel beds provides a novel settlement and living substratum for recruits and juveniles of S. argenvillei, albeit at much lower densities than in limpet patches. Adult limpets were virtually excluded from the mussel beds owing to their large size, which indicates the unsuitability of this habitat as a replacement substratum after competitive exclusion from primary rock space.Afr. J. mar. Sci. 25: 195–21

The Relationship of Drawing, Writing, Literacy and Math in Kindergarten Children

This study supports and extends previous research that suggests there is a relationship between picture naming and a variety of other factors that impact early literacy. The study explores the picture naming/representing ability of kindergarteners (n = 20), their ability to name and draw pictures of objects they could and could not immediately identify, and their early literacy and math assessments. Significant results were found for 1) drawing ratings and alphabet writing, and 2) alphabet writing, geometric shape sorting, and rhyming. Relationships between kindergarteners’ picturing naming and drawing and their early literacy assessment performance are explored

TEMPORAL CHANGES IN AN INTERACTION BETWEEN AN INDIGENOUS LIMPET SCUTELLASTRA ARGENVILLEI AND AN ALIEN MUSSEL MYTILUS GALLOPROVINCIALIS: EFFECTS OF WAVE EXPOSURE

A previous survey of 15 sites off the Namaqualand coast on the west coast of South Africa provided evidence of a competitive interaction between an alien mussel Mytilus galloprovincialis and an indigenous limpet Scutellastra argenvillei, and indicated that wave action mediates the strength of this interaction. In this study, the temporal persistence of these patterns was tested by selecting six sites, ranging from sheltered to very exposed, and monitoring them over a two-year period. The patterns remained consistent over time. Both S. argenvillei and M. galloprovincialis were perpetually absent from the most sheltered site. The limpet consistently dominated rock space at the semi-exposed site where mussel cover was always low. At exposed sites, M. galloprovincialis was dominant but its percentage cover varied temporally as a result of wave action, creating free space and allowing temporary expansion of limpet patches. However, with time the mussel recolonized the cleared rock space and repeatedly displaced the limpet from it. This provides additional observational evidence of competition for space between the alien invader and the indigenous limpet. It is concluded that S. argenvillei has a spatial refuge from M. galloprovincialis in areas with moderate wave action. However, the limpet is likely to become locally extinct on exposed shores because mussels outcompete it there and rapidly recolonize patches from which they have been temporarily eliminated by wave action.Afr. J. mar. Sci. 25: 213–22

Searching for the extra-tidal stars of globular clusters using high-dimensional analysis and a core particle spray code

Three-body interactions can eject stars from the core of a globular cluster, causing them to enter the Galactic halo as extra-tidal stars. While finding extra-tidal stars is imperative for understanding cluster evolution, connecting isolated extra-tidal field stars back to their birth cluster is extremely difficult. In this work, we present a new methodology consisting of high-dimensional data analysis and a particle spray code to identify extra-tidal stars of any Galactic globular cluster using M3 as a case study. Using the t-Stochastic Neighbour Embedding (t-SNE) and Uniform Manifold Approximation and Projection (UMAP) machine learning dimensionality reduction algorithms, we first identify a set of 103 extra-tidal candidates in the APOGEE DR17 data catalogue with chemical abundances similar to M3 stars. To confirm each candidate's extra-tidal nature, we introduce Corespray; a new Python-based three-body particle spray code that simulates extra-tidal stars for any Galactic globular cluster. Using Gaia EDR3 proper motions and APOGEE DR17 radial velocities, we apply multivariate Gaussian modelling and an extreme deconvolution to identify the extra-tidal candidates that are more likely to be associated with a distribution of Corespray-simulated M3 extra-tidal stars than the field. Through these methods, we identify 13 new high-probability extra-tidal stars of M3. Future applications of Corespray will yield better understandings of core dynamics, star formation histories and binary fractions in globular clusters.Comment: 15 pages, 8 figures, 2 tables. Submitted to Monthly Notices of the Royal Astronomical Societ

The dominant mechanism(s) for populating the outskirts of star clusters with neutron star binaries

It has been argued that heavy binaries composed of neutron stars (NSs) and millisecond pulsars (MSPs) can end up in the outskirts of star clusters via an interaction with a massive black hole (BH) binary expelling them from the core. We argue here, however, that this mechanism will rarely account for such observed objects. Only for primary masses $\lesssim$ 100 M$_{\odot}$ and a narrow range of orbital separations should a BH-BH binary be both dynamically hard and produce a sufficiently low recoil velocity to retain the NS binary in the cluster. Hence, BH binaries are in general likely to eject NSs from clusters. We explore several alternative mechanisms that would cause NS/MSP binaries to be observed in the outskirts of their host clusters after a Hubble time. The most likely mechanism is a three-body interaction involving the NS/MSP binary and a normal star. We compare to Monte Carlo simulations of cluster evolution for the globular clusters NGC 6752 and 47 Tuc, and show that the models not only confirm that normal three-body interactions involving all stellar-mass objects are the dominant mechanism for putting NS/MSP binaries into the cluster outskirts, they also reproduce the observed NS/MSP binary radial distributions without needing to invoke the presence of a massive BH binary. Higher central densities and an episode of core-collapse can broaden the radial distributions of NSs/MSPs and NS/MSP binaries due to three-body interactions, making these clusters more likely to host NSs in the cluster outskirts.Comment: 13 pages, 7 figures, 2 tables, submitted to MNRA

Chronic Overlapping Pain Conditions and Long-Term Opioid Treatment

OBJECTIVES: One in 5 people in the United States lives with chronic pain. Many patients with chronic pain experience a subset of specific co-occurring pain conditions that may share a common pain mechanism and that have been designated as chronic overlapping pain conditions (COPCs). Little is known about chronic opioid prescribing patterns among patients with COPCs in primary care settings, especially among socioeconomically vulnerable patients. This study aims to evaluate opioid prescribing among patients with COPCs in US community health centers and to identify individual COPCs and their combinations that are associated with long-term opioid treatment (LOT). STUDY DESIGN: Retrospective cohort study. METHODS: We conducted analyses of more than 1 million patients 18 years and older based on electronic health record data from 449 US community health centers across 17 states between January 1, 2009, and December 31, 2018. Logistic regression models were used to assess the relationship between COPCs and LOT. RESULTS: Individuals with COPCs were prescribed LOT 4 times more often than individuals without a COPC (16.9% vs 4.0%). The presence of chronic low back pain, migraine headache, fibromyalgia, or irritable bowel syndrome combined with any of the other COPCs increased the odds of LOT prescribing compared with the presence of a single COPC. CONCLUSIONS: Although LOT prescribing has declined over time, it remains relatively high among patients with certain COPCs and for those with multiple COPCs. These study findings suggest target populations for future interventions to manage chronic pain among socioeconomically vulnerable patients

Complex interplays between limpets and alien species in South Africa: multispecies interactions, zonation and size effects

Integrating observations and experiments, we address the progressive effects of three alien species, the mussels Mytilus galloprovincialis and Semimytilus patagonicus, and the barnacle Balanus glandula, on limpet species in South Africa. We describe four aspects: (1) Interactions among algae, the limpet Scutellastra granularis and M. galloprovincialis. (2) The influences of B. glandula on S. granularis and on the periwinkle Afrolittorina knysnaensis. (3) Transformation of the zonation of S. granularis by the successive arrival of these three aliens. (4) Assessment of how effective the published predictors of the effects of M. galloprovincialis have been when applied to S. patagonicus. We conclude: (a) Scutellastra granularis improves mussel survival and condition by regulating algae that would otherwise overgrow and smother the mussels. (b) Balanus glandula has largely occupied the upper half of rocky shores, and at high densities depletes or eliminates suitable bare-rock habitat for S. granularis. However, it has positive effects on another gastropod, A. knysnaensis. (c) Mytilus galloprovincialis dominates the midshore and has positive effects on the recruitment of S. granularis, but negatively influences adults of this limpet, so that its size composition, density, reproductive output and zonation are all altered by this mussel. (d) Semimytilus patagonicus presents different challenges to those created by M. galloprovincialis, settling at much greater densities, lower down the shore, and reaching smaller maximum sizes. Rather than generating a favourable habitat for epizootic S. granularis recruits and juveniles, it almost completely excludes that limpet. We conclude that the influences of alien species are not readily predictable, depending on the nature of the invader and recipient species, environmental conditions and complex interactions among species. Collectively, the three alien species now cover almost all zones on wave-exposed rocky shores, completing the ‘zonation squeeze’ on limpets, but are less influential on wave-sheltered shores and in years when recruitment is low

Recycling Aluminum

Students will investigate and compare the energy cost to produce aluminum products from aluminum ore and recycled aluminum. Students will perform an electrolysis activity to reinforce the idea that recycling metal requires less energy than mining and refining metals from their original source in the earth

El test de beneficio en los servicios intragrupo y su aplicabilidad en la normativa peruana del impuesto a la renta

Los grupos econ?micos multinacionales buscan optimizar su carga impositiva a trav?s de estructuras de negocio complejas que generan la erosi?n de la base imponible y el traslado de los beneficios fuera del pa?s de la gente. A fin de combatir dichos esquemas de planificaci?n, la Organizaci?n para la Cooperaci?n y el Desarrollo Econ?mico (OCDE) ha desarrollado el Plan BEPS. En el caso de los servicios intra-grupo la Acci?n 10 tiene como finalidad garantizar si los resultados de las operaciones intragrupo evaluadas desde la perspectiva de precios de transferencia generan valor econ?mico a la entidad usuaria del servicio. Este trabajo analiza la regulaci?n del test de beneficio en la legislaci?n peruana y si la misma es acorde con la propuesta planteada por la OCDE en la Acci?n 10 del plan BEPS y las directrices de precios de transferencia dadas por dicho organismo. Adem?s, se analiza y expone la problem?tica de la regulaci?n actual del test de beneficio y los aspectos que podr?an ser objeto de mejora por parte de la legislaci?n fiscal peruana

The i148m Pnpla3 polymorphism influences serum adiponectin in patients with fatty liver and healthy controls

BACKGROUND: Reduced adiponectin is implicated in the pathogenesis of nonalcoholic fatty liver disease (NAFLD) and steatohepatitis (NASH), and the I148M Patatin-like phospholipase domain-containing 3 (PNPLA3) polymorphism predisposes to NAFLD and liver damage progression in NASH and chronic hepatitis C (CHC) by still undefined mechanisms, possibly involving regulation of adipose tissue function. Aim of this study was to evaluate whether the I148M PNPLA3 polymorphism influences serum adiponectin in liver diseases and healthy controls. METHODS: To this end, we considered 144 consecutive Italian patients with NAFLD, 261 with CHC, 35 severely obese subjects, and 257 healthy controls with very low probability of steatosis, all with complete clinical and genetic characterization, including adiponectin (ADIPOQ) genotype. PNPLA3 rs738409 (I148M) and ADIPOQ genotypes were evaluated by Taqman assays, serum adiponectin by ELISA. Adiponectin mRNA levels were evaluated by quantitative real-time PCR in the visceral adipose tissue (VAT) of 35 obese subjects undergoing bariatric surgery. RESULTS: Adiponectin levels were independently associated with the risk of NAFLD and with the histological severity of the disease. Adiponectin levels decreased with the number of 148\u2009M PNPLA3 alleles at risk of NASH both in patients with NAFLD (p\u2009=\u20090.03), and in healthy subjects (p\u2009=\u20090.04). At multivariate analysis, PNPLA3 148\u2009M alleles were associated with low adiponectin levels (<6\u2009mg/ml, median value) independently of NAFLD diagnosis, age, gender, BMI, and ADIPOQ genotype (OR 1.67, 95% c.i. 1.07-2.1 for each 148\u2009M allele). The p.148\u2009M PNPLA3 variant was associated with decreased adiponectin mRNA levels in the VAT of obese patients (p\u2009<\u20090.05) even in the absence of NASH. In contrast, in CHC, characterized by adiponectin resistance, low adiponectin was associated with male gender and steatosis, but not with PNPLA3 and ADIPOQ genotypes and viral features. CONCLUSIONS: The I148M PNPLA3 variant is associated with adiponectin levels in patients with NAFLD and in healthy subjects, but in the presence of adiponectin resistance not in CHC patients. The I148M PNPLA3 genotype may represent a genetic determinant of serum adiponectin levels. Modulation of serum adiponectin might be involved in mediating the susceptibility to steatosis, NASH, and hepatocellular carcinoma in carriers of the 148\u2009M PNPLA3 variant without CHC, with potential therapeutic implications