First record of the cleptoparasitic bee genus Sphecodes from Puerto Rico (Hymenoptera: Halictidae)

This is the publisher's version, also available electronically from https://journals.ku.edu/index.php/melittology/article/view/4781.The cleptoparasitic bee genus Sphecodes Latreille (Halictinae: Halictini) is recorded from Puerto Rico for the first time. Sphecodes (Austrosphecodes) tainoi Engel was previously known from western Cuba but is here recorded from a series of males and females captured in south-central, central, and western Puerto Rico. Images of the species are provided along with brief remarks on observed variations and possible future directions of study into their natural history

FE analysis and experimental determination of a shaft deflection under three-point loading

Increasing industrial demand for new products including advanced production technology leads to substantial natural resources consumption. Furthermore, huge environmental pollution and emerging environmental legislation motivate the machine tools industry as one of the major resource consumers on a global scale to develop methods for more sustainable use of the Earth's resources. Machine tools re-engineering concerning design and failure analysis is an approach by which outdated machines are upgraded and restored to like-new machines. To evaluate the mechanical failure of the used machine components and to ensure their reliable future performance, it is essential to make material, design, and surface investigations. In this paper, an experimental approach based on the principle of a three-point bending test is presented to evaluate the shaft elastic behavior under loading. Moreover, finite element analysis and numerical integration method are used to determine the maximum linear deflection and bending stress of the shaft. Subsequently, a comparison between the results is made. In conclusion, it was found that the measured bending deflection and stress were well close to the admissible design values. Therefore, the shaft can be used again in the second life cycle. However, based on previous surface tests conducted, the shaft surface needs re-carburizing and refining treatments to ensure the reliable performance of the surface

Comunicação entre profissionais de saúde e familiares de pacientes pediátricos no contexto da internação hospitalar

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Poly-l/dl-lactic acid films functionalized with collagen IV as carrier substrata for corneal epithelial stem cells

Limbal epithelial stem cells (LESCs) are responsible for the renewal of corneal epithelium. Cultivated limbal epithelial transplantation is the current treatment of choice for restoring the loss or dysfunction of LESCs. To perform this procedure, a substratum is necessary for in vitro culturing of limbal epithelial cells and their subsequent transplantation onto the ocular surface. In this work, we evaluated poly-L/DL-lactic acid 70:30 (PLA) films functionalized with type IV collagen (col IV) as potential in vitro carrier substrata for LESCs. We first demonstrated that PLA-col IV films were biocompatible and suitable for the proliferation of human corneal epithelial cells. Subsequently, limbal epithelial cell suspensions, isolated from human limbal rings, were cultivated using culture medium that did not contain animal components. The cells adhered significantly faster to PLA-col IV films than to tissue culture plastic (TCP). The mRNA expression levels for the LESC specific markers, K15, P63α and ABCG2 were similar or greater (significantly in the case of K15) in limbal epithelial cells cultured on PLA-col IV films than limbal epithelial cells cultured on TCP. The percentage of cells expressing the corneal (K3, K12) and the LESC (P63α, ABCG2) specific markers was similar for both substrata. These results suggest that the PLA-col IV films promoted LESC attachment and helped to maintain their undifferentiated stem cell phenotype. Consequently, these substrata offer an alternative for the transplantation of limbal cells onto the ocular surface.This work was supported by the Carlos III National Institute of Health, Spain (CIBER-BBN and Spanish Network on Cell Therapy, (TerCel RD12/0019/0036), MINECO/FEDER, EU), and the Castilla y León Regional Government, Spain (Regional Center for Regenerative Medicine and Cell Therapy, SAN673/VA/28/08 and SAN126/VA11/09)

Snowmass Early Career: The Key Initiatives Organization

In April 2020, the 2019 and 2020 American Physical Society's Division of Particles and Fields (APS DPF) Early Career Executive Committee (ECEC) members were tasked with organizing the formation of a representative body for High-Energy Physics (HEP) early career members for the Snowmass process by the DPF Executive Committee. Here, we outline the structure we developed and the process we followed to help provide context and guidance for future early career Snowmass efforts. Our organization was composed of a cross-frontier branch with committees on Inreach, Diversity Equity and Inclusion, Survey, and Long Term Organizational Planning; in addition to the Frontier Coordination branch, formed by committees responsible for liaising with each Frontier. Throughout this document, the authors reflect on the triumphs and pitfalls of a program created from nothing over a very short period of time, by people with good intentions, who had no prior experience in building such an organization. Through this exercise of reflecting, we sometimes find that we would recommend a different path to our future selves. Insomuch as there are things to find fault with, it is in the robustness of the systems we built and refined.Comment: contribution to Snowmass 2021, 16 pages, 0 figure

Orquestar ayudas para el aprendizaje colaborativo: herramientas, guiones y retroalimentaciones.

Los profesores constatamos reiteradamente que la forma de resolver las actividades grupales por parte de los estudiantes universitarios está muy alejada de un proceso de colaboración de alto nivel. Para ayudar a los estudiantes a desarrollar competencias de trabajo colaborativo se ha implementado una propuesta instruccional en cuatro clases (209 estudiantes), que orquesta diferentes tipos de ayuda a distintos planos. Globalmente, estudiantes y docentes valoran de forma positiva la experiencia

Long-term decline in nest survival of a ground-nesting shorebird on a tropical island

Tropical islands harbour a disproportionally high number of endemic species, which face increasing threats due to habitat loss, disturbance and introduced alien predators. Long-term demographic studies are needed to understand how such threats may impact on population productivity. We report an investigation of a key demographic parameter, nest survival, over a 13-year period in a small ground-nesting shorebird on the island of Maio (Cabo Verde). Similar to many tropical islands, Maio is expected to face increased tourism, disturbance, and potential loss of nesting habitats. We monitored over 700 nests of the largest, year-round resident breeding population of Kentish plover in the Atlantic Ocean archipelago. Our work produced three important findings. First, we show that nest survival differed among the major habitats of the main breeding site, the Salinas do Porto Inglˆes, because nests in the salt-extraction area had higher daily survival rates DSR = 0.9654 ± 0.0076 SE than nests in grasslands DSR = 0.9557 ± 0.0038 SE. The salt-extraction is a dynamic habitat that is naturally regulated by rainfall and sea water inflow and managed with traditional methods for salt-extraction. Kentish plovers breed on small islets surrounded by salty water where mammalian predators may have restricted access. Second, we found that breeding densities of plovers decreased from 0.11 nests/ha to 0.03 nests/ ha over 13 years. Last, we show that nest survival declined from 0.9784 ± 0.0107 in 2007 to 0.8967 ± 0.0401 in 2019. We suggest that the declining breeding density and nest survival may be driven by a combination of ecological factors including predation by native and introduced species, and by increased human disturbance. To help maintain sustainable levels of nest survival and to ensure long-term persistence of this Kentish plover population, we propose to incorporate traditional Salinas management into direct conservation actions, to reduce human disturbance and manage nest predators to help nest survival on tropical islands. Breeding success Demography Disturbance Nest predation Nest survival MacaronesiapublishedVersio

Dissolved carbon biogeochemistry and export in mangrove-dominated rivers of the Florida Everglades

The Shark and Harney rivers, located on the southwest coast of Florida, USA, originate in the freshwater, karstic marshes of the Everglades and flow through the largest contiguous mangrove forest in North America. In November 2010 and 2011, dissolved carbon source–sink dynamics was examined in these rivers during SF6 tracer release experiments. Approximately 80 % of the total dissolved carbon flux out of the Shark and Harney rivers during these experiments was in the form of inorganic carbon, either via air–water CO2 exchange or longitudinal flux of dissolved inorganic carbon (DIC) to the coastal ocean. Between 42 and 48 % of the total mangrove-derived DIC flux into the rivers was emitted to the atmosphere, with the remaining being discharged to the coastal ocean. Dissolved organic carbon (DOC) represented ca. 10 % of the total mangrove-derived dissolved carbon flux from the forests to the rivers. The sum of mangrove-derived DIC and DOC export from the forest to these rivers was estimated to be at least 18.9 to 24.5 mmol m−2 d−1, a rate lower than other independent estimates from Shark River and from other mangrove forests. Results from these experiments also suggest that in Shark and Harney rivers, mangrove contribution to the estuarine flux of dissolved carbon to the ocean is less than 10 %

An Extended Model for the Evolution of Prebiotic Homochirality: A Bottom-Up Approach to the Origin of Life

A generalized autocatalytic model for chiral polymerization is investigated in detail. Apart from enantiomeric cross-inhibition, the model allows for the autogenic (non-catalytic) formation of left and right-handed monomers from a substrate with reaction rates $\epsilon_L$ and $\epsilon_R$, respectively. The spatiotemporal evolution of the net chiral asymmetry is studied for models with several values of the maximum polymer length, N. For N=2, we study the validity of the adiabatic approximation often cited in the literature. We show that the approximation obtains the correct equilibrium values of the net chirality, but fails to reproduce the short time behavior. We show also that the autogenic term in the full N=2 model behaves as a control parameter in a chiral symmetry- breaking phase transition leading to full homochirality from racemic initial conditions. We study the dynamics of the N -> infinity model with symmetric ($\epsilon_L = \epsilon_R$) autogenic formation, showing that it only achieves homochirality for $\epsilon < \epsilon_c$, where $\epsilon_c$ is an N-dependent critical value. For $\epsilon \leq \epsilon_c$ we investigate the behavior of models with several values of N, showing that the net chiral asymmetry grows as tanh(N). We show that for a given symmetric autogenic reaction rate, the net chirality and the concentrations of chirally pure polymers increase with the maximum polymer length in the model. We briefly discuss the consequences of our results for the development of homochirality in prebiotic Earth and possible experimental verification of our findings