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Roosting habits of disk-winged bats, especially Thyroptera discifera
Get PDFRoosting habits of disk-winged bats of the genus Thyroptera (Chiroptera: Thyropteridae) have been unknown to very poorly known except for those of the commonly encountered T. tricolor. Many secondary literature publications state that roosting habits of Thyroptera in general are those of tricolor, known to roost almost exclusively in vertical, unfurling large leaves, especially of native Heliconia and introduced banana (genus Musa). However, so far as known, no other species of Thyroptera chooses such roosts. Until 1993, the only species of Thyroptera known were tricolor and discifera—they had been the only two known for 139 years. During this long period, the unique roosting habits of tricolor often were attributed to the genus as a whole, as sometimes still happens today. Now there are three more known species—lavali, devivoi, and wynneae. In this paper, we correct misconceptions concerning roosting habits in Thyroptera, summarize what is known for all five species, and provide the first detailed observations on roosting in discifera. Thyroptera discifera has been found roosting attached to the underside of a palm leaflet or leaflets in Brazil and in conically curled portions of dead banana leaves in Costa Rica.
Los hábitos de selección de refugios de los murciélagos de ventosas del género Thyroptera (Chiroptera: Thyropteridae) han sido desconocidos o muy poco conocidos, con excepción a los hábitos de T. tricolor, que es la especie que se encuentra comúnmente. Muchas publicaciones de literatura secundaria afirman que los hábitos de selección de refugio de los Thyroptera en general son los mismos que los de tricolor, que son conocidos por descansar casi exclusivamente en hojas grandes verticales y parcialmente enrolladas, especialmente hojas de Heliconia nativa y banano introducido (género Musa). Sin embargo, por el momento no se conoce ninguna otra especie de Thyroptera que elija este tipo de refugio. Hasta 1993, las únicas especies de Thyroptera conocidas eran tricolor y discifera y habían sido las únicas dos especies conocidas durante 139 años. Durante este largo período, los hábitos particulares de selección de refugios de tricolor frecuentemente se atribuyeron a todo género, como a veces todavía sucede hoy en día. Actualmente se conocen tres especies más en este género: lavali, devivoi y wynneae. En este artículo, corregimos los conceptos erróneos sobre selección de refugios en Thyroptera, resumimos lo que se conoce de las cinco especies y brindamos las primeras observaciones detalladas sobre la selección de refugios de discifera. Thyroptera discifera se ha encontrado descansando adherido a la parte inferior de un folíolo o folíolos de palma en Brasil y en porciones de hojas muertas de plátano enrolladas cónicamente en Costa Rica
Internally-Cured Low-Cracking High-Performance Concrete (IC-LC-HPC) Bridge Decks: Durability and Cracking Performance
Get PDFThe laboratory portion of this study investigates the effects of internal curing (IC) water in pre-wetted lightweight aggregates (LWA) between 8.2 and 9.0% and between 12.0 and 13.1% by weight of binder and total internal (TI) water in all aggregates between 3.4 and 12.5% by weight of binder on freeze-thaw durability, scaling resistance, shrinkage, and ion transport properties of concrete mixtures with different binder compositions (100% portland cement or a ternary composition with 30% slag cement and 3% silica fume as partial replacements for portland cement [by total weight of cementitious materials]), paste as a percentage of concrete volume (23.7, 24.6, 26.7, or 33.7%), and water-to-cementitious material ratios (w/cm, 0.45 or 0.41). Normalweight aggregates consisted of three types of coarse aggregates and river sand.
The results show that for paste contents between 23.7 and 33.7% of concrete volume, the freeze-thaw durability of internally-cured concrete mixtures is a function of the percentage of IC water by the weight of binder, rather than total IC water per unit volume of concrete; all IC mixtures assessed for freeze-thaw durability in accordance with ASTM C666-Procedure A exhibited durability factors below 90% and failed the freeze-thaw test and would not be considered acceptable under MnDOT specifications, while some mixtures at w/c ratio of 0.45 and all mixtures at a w/c ratio of 0.41satisfied the requirements of ASTM C666-Procedure B and KTMR-22 and would be considered acceptable under KDOT specifications. The results also demonstrate that the freeze-thaw resistance of the mixtures decreased markedly when the TI water exceeded 12.0% by the weight of binder. Scaling test results show that as the paste content increases from 23.7 to 33.7%, the scaling resistance of the specimens decreases. At a w/cm ratio of 0.45 and a paste content of 23.7%, mixtures with an IC water content of 8.8% passed the scaling test; at a w/cm ratio of 0.41 and a paste content of 23.7%, mixtures with IC water contents less than or equal to 13% passed the scaling test. None of the mixtures with a paste content of 33.7% passed the scaling test at either w/cm ratio. Moreover, for a given binder composition and type of coarse aggregate, increased TI water resulted in higher scaling resistance. The type of coarse aggregate also had effects on scaling resistance. The ternary mixtures with granite as the coarse aggregate, had lower mass losses than the ternary mixtures with low-absorption limestone and similar quantities of TI water. As the TI water content increased, shrinkage decreased for concretes with both binder compositions. Mixtures with IC water exhibited more expansion at the end of the curing period than mixtures with no IC water. Increases in the TI water content in mixtures did not affect the rapid chloride permeability or surface resistivity measurements, while the binder composition did, with the ternary mixtures, on average, showing higher and lower SRM and RCP values, respectively, than mixtures containing 100% portland cement.
The second portion of the study involved the construction, crack surveys, and evaluation of 12 bridge decks (nine in Minnesota and three in Kansas) containing IC water and supplementary cementitious materials (SCMs) that were constructed between 2016 and 2021 following IC-LCHPC specifications (of Minnesota or Kansas) and two associated Control decks without IC. The decks were monolithic with the exception of three of the Minnesota decks, which had overlays. The results show that the use of overlays on bridge decks results in high crack densities and should be avoided. Low-cracking bridge decks require concrete with a paste content of 27.2% or less based on concrete volume. Paste contents above 27.2% correlate with increased cracking, and for decks with paste contents greater than 27.2%, the addition of IC and SCMs does not overcome the negative effects of high paste content. The results also indicate that the combination of low paste, internal curing, and good construction procedures offer the potential to reduce cracking. Under circumstances, good construction practices are needed for low-cracking decks. If poor construction practices are employed, even decks with low paste content and IC can exhibit high cracking and scaling damage
Understanding the social and community support experiences of sexual and gender minority individuals in 12-Step programs
Get PDFThis is an Accepted Manuscript of an article published by Taylor & Francis in Journal of Gay and Lesbian Social Services on 25 Jan 2023, available at: http://www.tandfonline.com/10.1080/10538720.2023.2172759.Sexual and gender minority individuals (e.g., gay, bisexual, non-binary, transgender; SGMI) are 2-6 times as likely as cisgender heterosexual individuals to experience alcohol or other substance use disorders. SGMI participate in 12-Step groups, such as Alcoholics Anonymous (AA), at high rates. Though social support is an established mechanism through which 12-Step programs support reductions in substance use, little is known about SGMI’s experiences of the social support in 12-Step programs. This qualitative study aims to understand the experiences of social and community support among SGMI involved in 12-Step programs. This study employed thematic analysis to interpret open-ended responses from 302 SGMI who had participated in 12-Step programs. Data was from The PRIDE Study, a large, national, online. longitudinal, cohort study of SGMI. Two themes emerged about how SGMI experienced social and community support in 12-Step programs: beneficial connections and harmful environments. Beneficial connections included a sense of community, shared experiences, and skills provision. Harmful environments included marginalization, oppression, violence, and bullying. This study highlights the variability of experiences of SGMI participating in 12-Step programs. These findings suggest that many SGMI may benefit from 12-Step programs but may need support in coping with potential harms that can emerge through participation
Effects of Total Internal Water Content on Freeze-Thaw Durability and Scaling Resistance of Internally-Cured Concrete
Get PDFThe effects of total internal (TI) water, provided by normalweight coarse and fine aggregates and pre-wetted fine lightweight aggregate (LWA), in the range of 6.8 to 17.3%, corresponding to internal curing (IC) water in the LWA ranging from 0 to 15.1%, by weight of cementitious materials, on the freeze-thaw durability and scaling resistance of 12 concrete mixtures are evaluated. Cementitious materials consist of portland cement only or portland cement with a 30% weight replacement by slag cement. The coarse aggregate consists of limestone (with an oven-dry absorption of 1.8%) or granite (with an oven-dry absorption of 0.6%), which provide 5.5 to 5.6% or 1.9% internal curing water by the weight of cementitious materials, respectively.
All of the mixtures with the limestone coarse aggregate failed the test, with the average dynamic modulus of elasticity (EDYN) dropping below 95% of the initial value well before the 660 freeze-thaw cycles specified by the Kansas Department of Transportation, demonstrating that the limestone itself is susceptible to freeze-thaw damage. The mixtures containing granite coarse aggregate had an average relative EDYN above 95% of the initial value at 660 freezethaw cycles in the test of freeze-thaw durability at TI water contents up to 15.7% (corresponding to an IC water content of 13.4% from the LWA) by the weight of cementitious materials. The only mixture with granite coarse aggregate that failed the test had a 30% weight replacement of portland cement with slag cement and a TI water content of 17.3% by weight of the cementitious materials (corresponding to 15.1% IC water from LWA). This result indicates that it is possible to have too much internal curing water. In the scaling test, the mixtures with granite coarse aggregate, all of which contained LWA, had lower mass losses than mixtures with limestone coarse aggregate, although all but one of the 12 mixtures passed the test with a cumulative 56-day mass loss below 0.1 lb/ft2. For concrete with granite coarse aggregate, the mass loss increased slightly with increased TI water content when portland iv cement was used as the only cementitious material. When a 30% weight replacement of portland cement with slag cement was used, the mass loss increased for a TI water content above 12.5% (corresponding to 9.9% IC water from LWA), but remained below the failure limit, suggesting no benefits for a TI water content above 12.5% by the weight of cementitious materials. The mixtures with portland cement as the only cementitious material had lower mass losses than the mixtures with a 30% weight replacement of portland cement with slag cement for the same coarse aggregate. Pre-wetted fine lightweight aggregate (LWA) for internal curing (IC) should equal 7 to 8% by weight of cementitious materials. The results provide no evidence that it would be advantageous to stray much above these values and demonstrate that high TI/ IC water contents can be deleterious
On conditional belief functions in directed graphical models in the Dempster-Shafer theory
Get PDFThe primary goal is to define conditional belief functions in the Dempster-Shafer theory. We do so similarly to probability theory's notion of conditional probability tables. Conditional belief functions are necessary for constructing directed graphical belief function models in the same sense as conditional probability tables are necessary for constructing Bayesian networks. We provide examples of conditional belief functions, including those obtained by Smets' conditional embedding. Besides defining conditional belief functions, we state and prove a few basic properties of conditionals. In the belief-function literature, conditionals are defined starting from a joint belief function. Conditionals are then defined using the removal operator, an inverse of Dempster's combination operator. When such conditionals are well-defined belief functions, we show that our definition is equivalent to these definitions
Output force and ratio of laparoscopic graspers: an evaluation of operating room ergonomics
Get PDFBackground
“Laparoscopist's thumb,” or thenar paresthesia, can result from prolonged or excessive grip force during laparoscopy, as can more general syndromes, such as carpal tunnel syndrome. This is particularly relevant in gynecology, where laparoscopic procedures are standard. Although this method of injury is well known, there is a paucity of data to guide surgeons in selecting more efficient, ergonomic instruments.
Objective
This study compared the ratio of applied tissue force and required surgeon input in a sample of common ratcheting laparoscopic graspers in a small-handed surgeon, to provide potential metrics applicable to surgical ergonomics and surgeon instrument choice.
Study Design
Laparoscopic graspers with varied ratcheting mechanisms and tip shapes were evaluated. Brands included Snowden-Pencer, Covidien, Aesculap, and Ethicon. A Kocher was used as an open instrument comparison. Flexiforce A401 thin-film force sensors were used to measure applied forces. Data were collected and calibrated using an Arduino Uno microcontroller board with Arduino and MATLAB software. Single-handed, complete closure of each device’s ratcheting mechanism was performed 3 times. The maximum required input force in Newtons was recorded and averaged. The average output force was measured with a bare sensor and the same sensor between 2 different thicknesses of LifeLike BioTissue.
Results
The most ergonomic ratcheting grasper for a small-handed surgeon was identified by the output ratio: the highest output force relative to the required surgeon input (the most force for the least amount of effort). The Kocher required an average input force of 33.66 N, with its highest output ratio of 3.46 (112 N output). The Covidien Endo Grasp was the most ergonomic, with an output ratio of 0.96 on the bare force sensor (31.4 N output). The Snowden-Pencer Wavy grasper was the least ergonomic, with an output ratio of 0.06 when applied to the bare force sensor (5.9 N output). All graspers except for the Endo Grasp had improving output ratios as tissue thickness and subsequent grasper contact area increased. Input force above that provided by the ratcheting mechanisms did not increase output force in a clinically relevant amount for any of the instruments evaluated.
Conclusion
Laparoscopic graspers vary widely in their ability to provide reliable tissue force without requiring excessive input by the surgeon, and a point of diminishing returns often exists with increased surgeon input over designed ratcheting mechanisms. Output force and output ratio are potential quantitative measures of the efficiency of laparoscopic instruments. Providing users with this type of data could assist in optimizing instrument ergonomics
Data-driven prognosis of failure detection and prediction of lithium-ion batteries
Get PDFBattery prognostics and health management predictive models are essential components of safety and reliability protocols in battery management system frameworks. Overall, developing a robust and efficient fault diagnostic battery model that aligns with the current literature is an essential step in ensuring the safety of battery function. For this purpose, a multi-physics, multi-scale deterministic data-driven prognosis (DDP) is proposed that only relies on in situ measurements of data and estimates the failure based on the curvature information extracted from the system. Unlike traditional applications that require explicit expression of conservation principle to represent the system's behavior, the proposed method devices a local conservation functional in the neighborhood of each data point which is represented as the minimization of curvature in the system. Pursuing such a deterministic approach, DDP eliminates the need for offline training regimen by considering only two consecutive time instances to make the prognostication that are sufficient to extract the behavioral pattern of the system. The developed framework is then employed to analyze the health of lithium ion batteries by monitoring the performance and detecting faults within the system's behavior. Based on the outcomes, the DDP exhibits promising results in detection of anomaly and prognostication of batteries' failure
Advancing the central role of non-model biorepositories in predictive modeling of emerging pathogens
Get PDFPhysicochemical characterization of biological and synthetic forms of two lipid A-based TLR4 agonists
Get PDFToll-like receptor (TLR) agonists are recognized as potential immune-enhancing adjuvants and are included in several licensed vaccines. Monophosphoryl lipid A (MPL®, GlaxoSmithKline) is one such TLR4 agonist that has been approved for use in human vaccines, such as Cervarix and Shingrix. Due to the heterogeneous nature of biologically derived MPL and the need for safer and more potent adjuvants, our groups have developed the novel TLR4 agonist candidates, BECC438 and BECC470 using the Bacterial Enzymatic Combinatorial Chemistry (BECC) platform. BECC438 and BECC470 have been included in studies to test their adjuvant potential and found to be effective in vaccines against both viral and bacterial disease agents. Here, we report detailed biophysical characterization of BECC438 and BECC470 purified from a biological source (BECC438b and BECC470b, respectively) and synthesized chemically (BECC438s and BECC470s, respectively). Both BECC438s and BECC470s have identical acyl chain configurations, BECC438s is bis-phosphorylated and BECC470s is mono-phosphorylated with the removal of the 4′ phosphate moiety. We determined the phase transition temperatures for the acyl chains of BECC438b and BECC470b and found them to be different from those exhibited by their synthetic counterparts. Furthermore, the phosphate groups of BECC438b and BECC470b are more highly hydrated than are those of BECC438s and BECC470s. In addition to exploring the BECC molecules’ biophysical features in aqueous solution, we explored potential formulation of BECC438 and BECC470 with the aluminum-based adjuvant Alhydrogel and as part of an oil-in-water emulsion (Medimmune Emulsion or ME). All of the lipid A analogues could be fully absorbed to Alhydrogel or incorporated onto ME. Surprisingly, the BECC470s molecule, unlike the others, displayed a nearly baseline signal when monitored using a Limulus amebocyte lysate (LAL) endotoxin detection system. Despite this, it was shown to behave as an agonist for human and mouse TLR4 when tested using multiple cell-based systems. This work paves the way for further formulation optimization of two chemically defined TLR4 agonists that are showing great promise as vaccine adjuvants
Public Montessori Early Childhood Educators’ Perceptions of Psychological Needs Fulfillment
Get PDFAs attrition rates of teachers remain a concern and the establishment of Montessori public schools increases in the United States, studying the needs satisfaction of Montessori public school teachers is a way to address issues of retainment. This qualitative methods study used the Self-Determination Theory framework to guide an analysis of factors that impact the levels of autonomy, relatedness, and competence within a public Montessori school teacher’s work environment. This study gave public Montessori teachers an opportunity to share their stories and provide context to the issue of work satisfaction and dissatisfaction. Findings indicated that there are several factors and experiences that impact a public Montessori school teacher’s experience with autonomy, relatedness, and competence in their daily work. Additional findings are that these factors impact Montessori teachers on different levels: personal, school, and external. In analyzing these factors and level of impact, administrators and school districts can make sure that the work environments of public Montessori teachers are conducive