cssi/SciSciGPT-SciSciNet huggingface dataset:
Potential Role of Regulatory T Cells in Mother-to-Child Transmission of HIV.

BACKGROUND Mother-to-child transmission of HIV-1 occurs in a minority of HIVinfected mother-infant pairs, even without any interventions. The mechanisms that protect the majority of HIV-exposed infants from infection are unclear. T regulatory cells (Treg) have important immunomodulatory functions, but their role in the fetus as well as in mother-to-child transmission of HIV is under-studied. METHODS We studied available cryopreserved peripheral blood mononuclear cells from HIVexposed infants from the Breastfeeding, Antiretrovirals and Nutrition (BAN) Study cohort in Malawi: 64 infants were HIV-uninfected and 28 infants were HIV-infected at birth. We quantified the frequency of Treg cells (CD4+CD25+FoxP3+), and activated CD4+ and CD8+ T cells (CD38+ HLADR+) by flow cytometry at birth, 6 weeks and 6, 9 and 12 months of age. Descriptive statistics were performed to describe the distributions of these lymphocyte markers according to the HIV infection status; and Student's t tests and Wilcoxon-Rank Sum tests were performed to compare HIVinfected and uninfected infants. RESULTS T cell activation increased rapidly in the first 6 weeks of life, more pronounced on CD8+ T cells; a further increase in activation was observed at the time of weaning from breastfeeding at 6 months of age. In contrast, the frequency of Treg was stable over the first 6 weeks of life (median, 0.5%), slightly decreased between 6 weeks and 6 months (median at 6 months, 0.3%) and then slightly increased between 6 months (time of weaning) and 12 months of age (median, 0.45%). HIVinfected infants had significantly higher frequencies of activated T cells than uninfected infants (P < 0.01). At the time of birth, HIV-exposed uninfected infants had higher levels of Treg, compared to infants infected in utero, even though this did not reach statistical significance in this small sample size (P = 0.08). CONCLUSION This study provides initial evidence that Treg may play a role in preventing mother-tochild transmission of HIV, likely by suppressing immune activation in the fetus and infant, and needs to be substantiated in a larger study. Better characterization of the role of Treg in fetal and neonatal immunity may provide a valuable complementary approach to achieve eradication of mother-to-child transmission of HIV.
Occipitocervical Osteotomies and Interfacet Grafts for Reduction of Occipitocervical Kyphosis and Basilar Invagination.

Background Occipitocervical congenital pathologies involving instability of the atlantoaxial joint and basilar invagination are challenging to treat owing to the complex anatomy involving neurovascular structures at the skull base and the high-risk nature of surgery close to the brainstem. Case Description A patient presented with Alagille syndrome with multiple segmentation/fusion anomalies of the cervical spine and craniocervical junction, including fusion of the skull base and occipital condyles and partial assimilation of the C1 anterior ring and C2 dens. The head was anteriorly displaced, with C2 located immediately below the foramen magnum. There was significant kyphotic angulation due to nonunion of the base of the dens and the body of C2. The patient underwent occipitocervical osteotomies and occiput-C2 interfacet grafts for reduction of occipitocervical kyphosis along with foramen magnum decompression and occiput-C6 fusion. The patient had significant neurologic improvement and sustained improved craniocervical alignment on last follow-up. Conclusions In patients with atlantoaxial instability with basilar invagination, posterior facet release, local distraction, and placement of cortical bone interbody grafts with occipitocervical fusion may be instrumental in reducing craniocervical kyphosis and compression by allowing anterior translation of the upper cervical spine relative to the skull. This method may be a safe and effective posterior-only approach for brainstem/spinal cord decompression for patients with complex craniocervical congenital malformations.
The inhibition of cellular toxicity of amyloid-beta by dissociated transthyretin

Abstract The protective effect of transthyretin (TTR) on cellular toxicity of amyloid-beta (Aβ) has been previously reported. TTR is a tetrameric carrier of thyroxine in blood and cerebrospinal fluid, whose pathogenic aggregation causes systemic amyloidosis. In contrast, many reports have shown that TTR binds amyloid-beta (Aβ), associated with Alzheimer’s disease, alters its aggregation, and inhibits its toxicity both in vitro and in vivo. In this study, we question whether TTR amyloidogenic ability and its anti-amyloid inhibitory effect are associated. Our results indicate that the dissociation of the TTR tetramer, required for its amyloid pathogenesis, is also necessary to prevent cellular toxicity from Aβ oligomers. These findings suggest that the Aβ binding site of TTR may be hidden in its tetrameric form. Aided by computational docking and peptide screening, we identified a TTR segment that is capable of altering Aβ aggregation and toxicity, mimicking TTR cellular protection. This segment inhibits Aβ oligomer formation and also promotes the formation of nontoxic, non-amyloid, amorphous aggregates which are more sensitive to protease digestion. This segment also inhibits seeding of Aβ catalyzed by Aβ fibrils extracted from the brain of an Alzheimer’s patient. Our results suggest that mimicking the inhibitory effect of TTR with peptide-based therapeutics represents an additional avenue to explore for the treatment of Alzheimer’s disease. Significance statement The pathological landmarks of Alzheimer’s disease are the formation of amyloid plaques and neurofibrillary tangles. Amyloid plaques contain fibrous structures made of aggregated amyloid-beta (Aβ). In 1982, Shirahama and colleagues observed the presence of transthyretin (TTR) in these plaques. TTR is a tetrameric protein whose aggregation causes transthyretin amyloidosis. However, TTR protects Aβ from aggregating and causing toxicity to neurons. In this study, we show that the dissociation of TTR tetramers is required to inhibit cellular toxicity caused by Aβ. In addition, we identified a minimum segment of TTR that inhibits Aβ aggregation and cellular toxicity by the formation of amorphous aggregates that are sensitive to proteases, similar to the natural effect of TTR found by others in vivo.
Diagnosis and Management of Intratubular Germ Cell Neoplasia in Situ: A Systematic Review.

Purpose:We performed a systematic review of studies assessing the diagnosis and effectiveness of management strategies for germ cell neoplasia in situ.Materials and Methods:Paired investigators ind...
Patterns of malformation associated with esophageal atresia/tracheoesophageal fistula: A retrospective single center study

Esophageal atresia/tracheoesophageal fistula (EA/TEF) is one of the most common gastrointestinal birth defects. It can occur in isolation or in association with other birth defects or genetic syndromes. We retrospectively reviewed the EA/TEF cases evaluated at Rady Children's Hospital San Diego (San Diego, CA) between 2007 and 2016. Data were collected for 157 patients. The majority of patients (105, 66.8%) had an associated major malformation present, and 52 patients (33.1%) had isolated EA/TEF. The patients with associated malformations were distributed as follows: 16 patients (10.2%) had a known genetic syndrome (the most common being Trisomy 21 in 11 patients); six patients (3.8%) had a suspected genetic syndrome; one patient had a suspected teratogenic syndrome (diabetic embryopathy); 30 patients had VACTERL association (19.1%); 32 patients had a "partial VACTERL" association (only two VACTERL-type defects without other malformation); nine patients (5.7%) had one additional non-VACTERL-type birth defect, two patients had VACTERL-type defects plus auricular malformations; and nine patients (5.7%) were classified as "unknown syndrome." A classification of the patterns of malformation of patients with congenital EA/TEF is proposed based on reviewing the data of this relatively large and phenotypically diverse patient group.
Dislocation density-based plasticity model from massive discrete dislocation dynamics database

Abstract We present a dislocation density-based strain hardening model for single crystal copper through a systematic coarse-graining analysis of more than 200 discrete dislocation dynamics (DDD) simulations of plastic deformation under uniaxial tension. The proposed constitutive model has two components: a generalized Taylor relation connecting resolved shear stresses to dislocation densities on individual slip systems, and a generalized Kocks-Mecking model for dislocation multiplication. The DDD data strongly suggests a logarithmic dependence of flow stress on the plastic shear strain rate on each slip system, and, equivalently, an exponential dependence of the plastic shear strain rate on the resolved shear stress. Hence the proposed generalized Taylor relation subsumes the Orowan relation for plastic flow. The DDD data also calls for a correction to the Kocks-Mecking model of dislocation multiplication to account for the increase of dislocation density on slip systems with negligible plastic shear strain rate. This is accomplished by allowing the multiplication rate on each slip system to include contributions from the plastic strain rates of the two coplanar slip systems. The resulting constitutive model successfully captures the strain hardening rate dependence on the loading orientation as predicted by the DDD simulations, which is also consistent with existing experiments.
Computational time-resolved imaging, single-photon sensing, and non-line-of-sight imaging

Emerging detector technologies are capable of ultrafast capture of single photons, enabling imaging at the speed of light. Not only can these detectors be used for imaging at essentially trillion frame-per-second rates, but combining them with computational algorithms has given rise to unprecedented new imaging capabilities. Computational time-resolved imaging has enabled new techniques for 3D imaging, light transport analysis, imaging around corners or behind occluders, and imaging through scattering media such as fog, murky water, or human tissue. With applications in autonomous navigation, robotic vision, human-computer interaction, and more, this is an area of rapidly growing interest. In this course, we provide an introduction to computational time-resolved imaging and single photon sensing with a focus on hardware, applications, and algorithms. We describe various types of emerging single-photon detectors, including single-photon avalanche diodes and avalanche photodiodes, which are among the most popular time-resolved detectors. Physically accurate models for these detectors are described, including modeling parameters and noise statistics used in most computational algorithms. From the application side, we discuss the use of ultrafast active illumination for 3D imaging and transient imaging, and we describe the state of the art in non-line-of-sight imaging, which requires modelling and inverting the propagation and scattering of light from a visible surface to a hidden object and back. We describe time-resolved computational algorithms used in each of these applications and offer insights on potential future directions.
Validation of the Polar Team Pro System for Sprint Speed With Ice Hockey Players.

Conners, RT, Whitehead, PN, Dodds, FT, Schott, KD, and Quick, MC. Validation of the polar team pro system for sprint speed with ice hockey players. J Strength Cond Res XX(X): 000-000, 2020-Commercially available player tracking sensors such as the Polar Team Pro system (PTPS) have been used to monitor athlete performance. Use during ice hockey practices and games has resulted in seemingly plausible and valid values for internal metrics (heart rate); however, external metrics (distance, speed, and acceleration) seem sporadic and counterintuitive. To determine the validity of the PTPS for measuring sprint speed with collegiate hockey players, 15 NCAA Division I male athletes (21.86 ± 1.04 years, 175.86 ± 6.78 cm, 80.58 ± 4.44 kg) participated in the study. Subjects wore a PTPS strap, at the level of the xiphoid process, and performed 2 sprints of 15.24 m (blue line to blue line) and 35.05 m (red line to the far blue line) in 3 conditions: indoor ice skating, indoor running, and outdoor running. Timing gates (TG) were used to determine sprint times, which allowed for manual calculation of speed. Speed values from the PTPS and TG were compared using paired-samples t-tests, and an alpha level of 0.05, 2-sided, was set a priori as a significance level. For indoor ice skating, PTPS significantly underestimated speeds at both distances (p < 0.001). However, PTPS significantly overestimated speeds for indoor and outdoor sprints at both distances (p ≤ 0.001). The PTPS is not accurate for measuring short-distance linear sprint speed or linear sprint speed during indoor ice skating. The inconsistency in speed values needs to be taken into consideration when using the system for science-based training because inaccurate speed values may negatively affect other external performance metrics provided by PTPS.
Where Self-Interest Trumps Ideology: Liberal Homeowners and Local Opposition to Housing Development

How much does self-interest drive Americans’ policy attitudes? Survey research typically finds that self-interest’s role is minimal. Such conclusions are typically reached by examining attitudes to...
Functional performance in a virtual reality task with differential executive functional loads

Abstract We presented a Virtual Reality (VR)-based functional task with three executive functional load levels and examined some aspects of this task using performance data of young healthy adults. We named the task the modified version of kitchen test (MVKT) from the Virtual Reality Functional Capacity Assessment Tool (VRFCAT). A sample of 42 participants (age M ​= ​20.95, SD ​= ​2.66; 69.05% female; 85.71% right handedness) completed MVKT and took a questionnaire regarding user experience and strategy use. First, we have evidence for good user experience. Chunking, visual and verbal strategies were reported to be used by most participants. Second, working memory capacity cannot fully predict performance in young healthy adults. This lack of meaningful relationship between the two was consistent across all three levels. Finally, we investigated the impact of executive functional load on the task performance. Quantitative analysis showed that performance declined as the load increased. Process analysis demonstrated that executive functional load impacted the sequential patterns of process, supporting the notion that people completed the task by proceeding down different paths to performance. We hope that by presenting our work, we have highlighted the unique characteristics of VR-based functional assessment to researchers who are interested in these methods.
Initial Study of Information Literacy Content in Engineering and Technology Job Postings

The goal of this research category work-in-progress study is to investigate the information literacy needs and expectations of employers who hire new engineering and technology graduates, through content analysis of job postings. It seeks to answer two questions: (1) Which information sources do employers expect engineering and technology graduates to know and to use on the job and (2) in what ways are new engineering and technology hires expected to interact with information?A collection of 1502 entry-level job postings aimed at undergraduate engineering and engineering technology students was gathered from a university career center database for the time period May 2017 to May 2018. Three researchers coded a sample of the job postings to calibrate and to develop a code book consisting of the types of information mentioned (journal articles, laws and regulations, technical requirements and specifications, product literature, technical reports, patents, and technical standards and codes) and specific ways of interacting with information (gathering, learning, evaluating, using, managing, creating, and communicating). Next, each researcher utilized NVivo to analyze a subset of the postings using the code book. The researchers will conduct additional analysis in order to make sure the data is reliably coded, but some trends are already obvious.Preliminary results suggest that employers often place their emphasis on different sources of information than those traditionally emphasized in academic settings. Job postings that deal with information sources list experience with standards and codes, both in general and citing specific organizations or documents, as the most common information source requirement. In contrast, journal articles and conference proceedings, often the focus of IL instruction, are barely mentioned in this data set. These findings indicate the need for a new approach to information literacy by engineering educators and librarians to better align with workplace information use.
Extracellular vesicles Transfer Polarized Mitochondria and Increase Cellular Energetics in Ischemic Endothelial Cells

Extracellular vesicles (EVs) such as exosomes (EXOs) and microvesicles (MVs) are promising carriers for the delivery of biologic drugs such as nucleic acids and proteins. We have demonstrated, for the first time, that EVs derived from hCMEC/D3: a human brain endothelial cell (BEC) line transfer polarized mitochondria to recipient BECs in culture and to neurons in mice acute brain cortical and hippocampal slices. This mitochondrial transfer increased ATP levels by 100 to 200-fold (relative to untreated cells) in the recipient BECs exposed to oxygen-glucose deprivation, an in vitro model of cerebral ischemia. Our previous studies suggested that EXOs, the smaller vesicle subpopulation, derived from a macrophage cell line (RAW264.7) load more exogenous plasmid DNA compared to the larger MVs and the RAW-derived EXOs also demonstrated greater transfection in the recipient BECs compared to EXOs derived from the homotypic hCMEC/D3 BECs. Proteomic analysis of EVs indicated that RAW-EVs are preferentially enriched with proteins that are involved in the trafficking of DNA-containing particles from the cytoplasm towards the nucleus. Intriguingly, although the heterotypic macrophage-derived EVs demonstrated increased transfection in the recipient BECs; the homotypic, BEC-derived EVs demonstrated a greater selectivity to transfer polarized mitochondria and increase endothelial cell survival under ischemic conditions. HighlightsO_LIEVs transfer polarized mitochondria to endothelial cells and acute brain slices C_LIO_LIMitochondrial transfer increased ATP in ischemic brain endothelial cells (BECs) C_LIO_LIBEC-EVs demonstrate greater mitochondrial transfer to recipient BECs C_LIO_LIMacrophage-derived EVs are better DNA transfection agents in recipient BECs C_LIO_LIMacrophage-EVs are enriched in proteins associated with nuclear trafficking of DNA C_LI
GAGrank: Software for Glycosaminoglycan Sequence Ranking Using a Bipartite Graph Model.

Abstract The sulfated glycosaminoglycans (GAGs) are long, linear polysaccharide chains that are typically found as the glycan portion of proteoglycans. These GAGs are characterized by repeating disaccharide units with variable sulfation and acetylation patterns along the chain. GAG length and modification patterns have profound impacts on growth factor signaling mechanisms central to numerous physiological processes. Electron activated dissociation tandem mass spectrometry is a very effective technique for assigning the structures of GAG saccharides; however, manual interpretation of the resulting complex tandem mass spectra is a difficult and time-consuming process that drives the development of computational methods for accurate and efficient sequencing. We have recently published GAGfinder, the first peak picking and elemental composition assignment algorithm specifically designed for GAG tandem mass spectra. Here, we present GAGrank, a novel network-based method for determining GAG structure using information extracted from tandem mass spectra using GAGfinder. GAGrank is based on Google’s PageRank algorithm for ranking websites for search engine output. In particular, it is an implementation of BiRank, an extension of PageRank for bipartite networks. In our implementation, the two partitions comprise every possible sequence for a given GAG composition and the tandem MS fragments found using GAGfinder. Sequences are given a higher ranking if they link to many important fragments. Using the simulated annealing probabilistic optimization technique, we optimized GAGrank’s parameters on ten training sequences. We then validated GAGrank’s performance on three validation sequences. We also demonstrated GAGrank’s ability to sequence isomeric mixtures using two mixtures at five different ratios.
Disparities in digital access among American rural and urban households and implications for telemedicine-based services.

Purpose To examine characteristics associated with disparities in digital access (i.e., access to high-speed Internet via a computer or smartphone) in American rural and urban households given that digital access has a direct impact on access to telemedicine-based services. Methods Using the 2019 American Community Survey, we analyzed the proportions of geographic area, race/ethnicity, and socioeconomic status according to device and high-speed Internet access. Maximum likelihood logit estimators estimated how these factors influenced device and high-speed Internet access. Findings Of 105,312,959 households, 32.29% were without a desktop or laptop computer with high-speed Internet (WDW), 21.51% were without a smartphone with a data plan for wireless Internet (WSW), and 14.02% were without any digital access (WDA). Nonmetropolitan households were significantly more likely to be WDA than metropolitan households (odds ratio [OR] = 1.87; 95% confidence interval [CI]: 1.83-1.91). Relative to non-Hispanic Whites, non-Hispanic Blacks (OR = 1.60; 95% CI: 1.56-1.64), American Indian or Alaska natives (OR = 2.00; 95% CI: 1.82-2.19), or Hispanics (OR = 1.70; 95% CI: 1.66-1.74) were significantly more likely to be WDA. When compared to households with private health insurance coverage, households WDA were significantly more likely to have no insurance (OR = 2.44; 95% CI: 2.36-2.53) or public insurance coverage (OR = 3.78; 95% CI: 3.70-3.86). Households with any digital access reported higher income and more family members living at home. Using the same predictors, similar findings were reported for households WDW or WSW. Conclusions Significant disparities in digital access exist among nonmetropolitan households, racial/ethnic minority households, and lower-income households. The lack of digital access has implications for the accessibility of health care services via telemedicine and thus could exacerbate health disparities.
Polarity establishment requires dynamic actin in fucoid zygotes

Previous work has demonstrated that actin plays important roles in axis establishment and polar growth in fucoid zygotes. Distinct actin arrays are associated with fertilization, polarization, growth, and division, and agents that depolymerize actin filaments (cytochalasins, latrunculin B) perturb these stages of the first cell cycle. Rearrangements of actin arrays could be accomplished by transport of intact filaments and/or by actin dynamics involving depolymerization of the old array and polymerization of a new array. To investigate the requirement for dynamic actin during early development, we utilized the actin-stabilizing agent jasplakinolide. Immunofluorescence of actin arrays showed that treatment with 1–10 μM jasplakinolide stabilized existing arrays and induced polymerization of new filaments. In young zygotes, a cortical actin patch at the rhizoid pole was stabilized, and in some cells supernumerary patches were formed. In older zygotes that had initiated tip growth, massive filament assembly occurred in the rhizoid apex, and to a lesser degree in the perinuclear region. Treatment disrupted polarity establishment, polar secretion, tip growth, spindle alignment, and cytokinesis but did not affect the maintenance of an established axis, mitosis, or cell cycle progression. This study suggests that dynamic actin is required for polarization, growth, and division. Rearrangements in actin structures during the first cell cycle are likely mediated by actin depolymerization within old arrays and polymerization of new arrays.
The effects of radiation on schedule-controlled responding and quinpirole-induced yawning (839.6)

A previous report noted that rats receiving head-only radiation exposure displayed neurobehavioral deficits on the rodent psychomotor vigilance task (rPVT), including changes in accuracy and premature responding. These changes were only apparent in a subset of irradiated rats, such that radiation-sensitive and radiation-insensitive groups emerged. Group specific changes in levels of the dopamine D2 receptor and dopamine transporter (DAT) protein were also evident, in addition to differential sensitivity to the rate-decreasing effects of quinpirole on schedule-controlled responding. To better understand DA system differences in radiation sensitivity, a cohort of rats was trained to perform the rPVT and then trained on a fixed-ratio 30 fixed-interval 2-min schedule of reinforcement; dopaminergic compounds were administered prior to the FR-FI session to determine the rate-altering effects of these drugs in individual subjects. A second cohort of rats was trained to perform the rPVT and was then observed for ...
VHDL Modeling of Optoelectronic Interconnect Networks

High performance computer and communication systems of today demands improvements in communication delay and connectivity. Optoelectronic interconnect is well recognized as a technology to provide the necessary improvement. However the complexity of optoelectronic systems is motivating a need for CAD tools which can simulate electronic and optoelectronic device and circuit behaviors simultaneously and at multiple levels of abstraction. This paper describes VHDL modeling of optical signals and integrated optical waveguides which enables seamless integration of mixed electronic/optoelectronic simulations in an established electronic design automation environment.
Conservative Surgery and Radiation Therapy as Treatment for Patients with Early Breast Cancer: Treatment Policy at the Harvard Joint Center for Radiation Therapy

The combination of conservative surgery and radiation therapy has become a more widely employed treatment approach for patients with early breast cancer. Cooperation between the surgeon, radiologist, pathologist, radiation therapist and medical oncologist is critical in obtaining good results using this approach. In this article, we summarize the treatment policy at the Harvard Joint Center for Radiation Therapy with concentration on treatment techniques and their appropriate application.
Equilateral distribution of ovarian tumors.

Abstract A series of 862 ovarian tumors was evaluated. There was no statistical difference in the number of cases involving the left and right ovaries. There appears to be no advantage in removal of one ovary over its opposite as a means of further decreasing the incidence of subsequent ovarian tumors.
Insights into the effect of dilute acid, hot water or alkaline pretreatment on the cellulose accessible surface area and the overall porosity of Populus

Pretreatment is known to make biomass more reactive to cellulase by altering the chemical compositions as well as physical structures of biomass. Simons’ staining technique along with mercury porosimetry was applied on the acid, neutral, and alkaline pretreated materials to measure the accessible surface area of cellulose and pore size distribution of Populus. The results indicated that acid pretreatment is much more effective than water and alkaline pretreatment in terms of cellulose accessibility increase. Further investigation suggests that lignin does not dictate cellulose accessibility to the extent that hemicellulose does, but it does restrict xylan accessibility which in turn controls the access of cellulase to cellulose. The most interesting finding is that severe acid pretreatment significantly decreases the average pore size, i.e. 90% average size decrease could be observed after 60 min dilute acid pretreatment at 160 °C; however, the nano-pore space formed between the coated microfibrils increased after pretreatment, especially with the acid pretreatment, suggesting that this particular type of biomass porosity is probably the most fundamental barrier to effective enzymatic hydrolysis.
Fabrication of conductive polyaniline hydrogel using porogen leaching and projection microstereolithography

Conducting hydrogels represent a new generation of “smart” biomaterials which combine the favorable biocompatibility properties of hydrogels and electrical properties of organic conductors, and would potentially lead to the development of new biointerfaces with controllable properties. Currently, conductive hydrogels are synthesized by either adding conducting particles to, or polymerizing conducting polymer monomers within, hydrogel matrix, however challenges in processing limit their applications in functional devices. In this work, a poly(ethylene glycol) diacrylate–polyaniline (PEGda–PANI) conductive hydrogel is developed using interfacial polymerization process. In this process, aniline monomers polymerize at the organic/water interface between hexane media and hydrophilic PEGda hydrogel networks. PANI chains become hydrophilic with acid doping and migrate into aqueous phase confined within PEGda networks. The synthesized PEGda–PANI hydrogel has acceptable mechanical, electrical and biocompatible properties. Traditional fabrication methods including process-driven salt-leaching and design-driven projection stereolithography were used to develop 3D scaffolds using PEGda–PANI hydrogels. This methodology can be potentially extended to a wide variety of fabrication techniques to develop hydrogels with complex geometries and next-generation functional biointerfaces.
Memory Replay in the Hippocampus

The hippocampus is required for the encoding, consolidation, and retrieval of episodic memories, but the neural mechanisms underlying these processes are still not well understood. Apart from place field activity, hippocampal neurons exhibit replay of past experience during sharp-wave ripples (SWRs), which involve sequential reactivation of hippocampal place cells representing previously experienced behavioral trajectories on a fast timescale. Replay during SWRs occurs both during slow-wave sleep and in the awake state, especially during periods of relative immobility. Repetition of stored memory patterns on a compressed timescale during replay is ideally suited to promote memory consolidation in distributed hippocampal–neocortical circuits. Further, since memory replay during SWRs has the capacity to recreate patterns of activity associated with past experience in hippocampal–neocortical circuits, it is also well suited to support memory retrieval. Thus, a common physiological mechanism, memory replay during SWRs, may underlie the consolidation and retrieval functions of the hippocampus.
An active-learning laboratory on respiratory devices

Abstract Objective To implement and evaluate an active-learning laboratory activity designed to teach second-year pharmacy students about the appropriate use of various respiratory devices including proper inhalation technique, device maintenance, and counseling points. Methods The laboratory session was divided into four small-group teaching stations: (1) nebulizers, (2) chronic obstructive pulmonary disease (COPD) exacerbation case and HandiHaler ® , (3) dry powder inhalers, and (4) metered dose inhalers and spacers. Students completed a pre-assessment and a post-assessment to measure changes in their respiratory device knowledge and confidence. McNemar's test and a paired t -test were used to determine statistical significance. Results Both the pre- and the post-assessments were completed by 131 of the 133 students enrolled (98.5%). The average score on pre-assessment knowledge-based questions was 52.7% (range: 10–90%). The post-assessment average score improved to 86.6% (range: 30–100%). Student's confidence improved in all of the four areas. All knowledge and confidence improvements were statistically significant (p Conclusion An active-learning approach facilitated students' gain in knowledge, confidence, and experience with the various devices used to deliver respiratory medications.
Effects of stream discharge, alluvial depth and bar amplitude on hyporheic flow in pool-riffle channels

[1] Hyporheic flow results from the interaction between streamflow and channel morphology and is an important component of stream ecosystems because it enhances water and solute exchange between the river and its bed. Hyporheic flow in pool-riffle channels is particularly complex because of three-dimensional topography that spans a range of partially to fully submerged conditions, inducing both static and dynamic head variations. Hence, these channels exhibit transitional conditions of streambed pressure and hyporheic flow compared to previous studies of fully submerged, two-dimensional bed forms. Here, we conduct a series of three-dimensional simulations to investigate the effects of bed topography, depth of alluvium, and stream discharge on hyporheic flow in pool-riffle reaches with variable bed form submergence, and we propose three empirical formulae to predict the mean depth of hyporheic exchange and characteristic values of the residence time distribution (mean and standard deviation). Hyporheic exchange is predicted with a three-dimensional pumping model, and hyporheic flow is modeled as a Darcy flow. We find that the hyporheic residence time is well approximated by a lognormal distribution for both partially and entirely submerged pool-riffle topography, with the parameters of the distribution defined by the mean and variance of the log-transformed residence time. Depth of alluvium has a substantial effect on hyporheic flow when alluvial depth is less than a third of the bed form wavelength for the conditions examined.
Restorative encoding memory integrative neural device: “REMIND”

Construction and application of a neural prosthesis device that enhances existing and replaces lost memory capacity in humans is the focus of research described here in rodents. A unique approach for the analysis and application of neural population firing has been developed to decipher the pattern in which information is successfully encoded by the hippocampus where mnemonic accuracy is critical. A nonlinear dynamic multi-input multi-output (MIMO) model is utilized to extract memory relevant firing patterns in CA3 and CA1 and to predict online what the consequences of the encoded firing patterns reflect for subsequent information retrieval for successful performance of delayed-nonmatch-to-sample (DNMS) memory task in rodents. The MIMO model has been tested successfully in a number of different contexts, each of which produced improved performance by a) utilizing online predicted codes to regulate task difficulty, b) employing electrical stimulation of CA1 output areas in the same pattern as successful cell firing, c) employing electrical stimulation to recover cell firing compromised by pharmacological agents and d) transferring and improving performance in naive animals using the same stimulation patterns that are effective in fully trained animals. The results in rodents formed the basis for extension of the MIMO model to nonhuman primates in the same type of memory task that is now being tested in the last step prior to its application in humans.
Direct ESR and spin trapping methods for the detection and identification of radical fragments in Nafion membranes and model compounds exposed to oxygen radicals

Abstract Direct electron spin resonance (ESR) and spin trapping methods are used in our laboratory in order to identify radical fragments in fluorinated membranes (Nafion) used in fuel cells and in model compounds when exposed to reactive oxygen species. Oxygen radicals were generated by the Fenton reaction, by the photo-Fenton method, and by UV-irradiation of aqueous H 2 O 2 solutions. Direct ESR detection led to the identification of fluorinated radical fragments in UV-irradiated Nafion neutralized by Cu(II), Fe(II), and Fe(III) cations and exposed to H 2 O 2 . In Nafion exposed to the Fenton reagent in the presence of DMPO (5,5-dimethyl-1-pyrroline) as the spin trap, radical adducts of hydroxyl and carbon-centered radicals (CCRs) were detected. A fluorinated model compound, perfluro-(2-ethoxyethane) sulfonic acid (CF 3 CF 2 OCF 2 CF 2 SO 3 H, PFEESA), that mimics the side chain of Nafion was chosen for study, with the goal to shed light on the more complicated degradation processes in the polymeric membranes. Analysis of the spin adducts obtained from UV-irradiated PFEESA in the presence of H 2 O 2 and MNP (2-methyl-2-nitrosopropane) as the spin trap suggested that the side chain of Nafion is a possible site of attack by oxygen radicals.
Making sense with thyroid hormone--the role of T(3) in auditory development.

In this Review, the authors discuss the auditory system as an example of how T3 is involved in the development of the sensory systems. Sensory defects in human genetic disorders featuring impaired T3 signalling are also outlined.
When is the Optimal Economic Rotation Longer than the Rotation of Maximum Sustained Yield

Abstract Contrary to the assertions of many, the rotation which maximizes the net present value of timber receipts may be longer than the rotation which maximizes average annual physical yield. This circumstance may arise even in a very simple economic model once regeneration and management costs are recognized. The most interesting situations arise with short rotation, fast growing species. Along with a theoretical comparison of the two rotation criteria, an example using Pinus patula plantations in Tanzania demonstrates the potential practical importance of this conclusion.
Nonlinear surface resistance in YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films

A complete characterization of the nonlinearity of the surface impedance Z/sub s/ of YBa/sub 2/Cu/sub 3/O/sub 7-x/ thin films is presented. Z/sub s/(H/sub rf/, the RF magnetic field), has been measured for H/sub rf/ from 0 to approximately 1 kOe vs. temperature from 4.2 K to critical temperature T/sub c/ and vs. frequency from 1.5 to 10 GHz, using a stripline resonator. The results are compared to a coupled-grain model. Good agreement is found for R/sub s/(H/sub rf/). The imaginary part of Z/sub s/(H/sub rf/), i.e. X/sub s/(H/sub rf/), however, does not fit the model. >
Blood donor eligibility, recruitment, and retention.

To study the motivation and actions of potential and active blood donors, a literature search, a limited survey, and associated analytic efforts were undertaken. It is estimated that 61 million of the 114 million age-eligible donors meet Red Cross criteria of health-eligibility. The 1971 donor participation rate, calculated as the percentage ratio of active donors to eligible donors, was estimated to be between 8 and 9 per cent. Total collections appear to be increasing at a stable rate of 1 per cent per year and 15 per cent of each year's collections apparently come from first-time donors. Thus, 14 per cent of those who donate blood in any given year must replace other donors who have stopped donating. Roughly 25 per cent of those who are health-eligible to donate blood have done so in the last ten years. Literature and survey analyses indicate that donor reaction rates are considerably underestimated by most collectors. A limited survey showed that the main reason for nonparticipation is fear, while common reasons for discontinuing participation are adverse reaction and medical disqualification.
Recent research quantifying anthropogenic CO2 emissions at the street scale within the urban domain

This paper provides a review of the need, challenges and recent research aimed at quantifying anthropogenic CO2 emissions for urban areas at spatial scales below the whole city, and sub-annual temporal scales. With whole-city CO2 emissions budget research as a starting point, suburban efforts must first clearly identify the accounting framework, sectoral boundaries, chemical form, spatial domain and the space/time resolution desired. The only efforts, to date, have performed analysis in a few North American cities utilizing a combination of true “bottom-up” and space/time downscaling techniques. Numerous challenges are faced when estimating CO2 emissions at these scales, including data availability, data idiosyncrasy and uncertainty quantification. Though cities in high-income countries are in possession of the needed data, data availability may pose far greater difficulties in other parts of the world. Because much of the data that is available does not possess uncertainty estimates, quantification of CO...
Quantitation of the frequency of immortalization of normal human diploid fibroblasts by SV40 large T-antigen

Abstract The mechanism by which SV40 large T-antigen immortalizes human lung fibroblasts is not yet understood, and the frequency with which immortalization occurs is unknown. Here we report detailed studies of the kinetics of immortalization. Approximately 20–50% of individual T-antigen transfected clones of IMR-90 human lung fibroblasts are able to immortalize. The failure of some clones to immortalize is consistent with the hypothesis that in some cells the aneuploidy induced by T-antigen produces extra copies of the chromosome containing a factor that must be inactivated before immortalization occurs. Within immortalization-competent clones, the frequency of immortalization is about 3×10 −7 . This frequency is consistent with a mutational mechanism for the inactivation of the factor that causes crisis in T-antigen expressing cells.
CONCRETE MIXTURE PROPORTIONING WITH WATER-REDUCING ADMIXTURES TO ENHANCE DURABILITY : A QUANTITATIVE MODEL

Abstract Durable concrete is characterized as concrete with a low porosity, in which the individual grains of cement are tightly packed before initiation of hydration. Such concrete is typically characterized by a low water cement ratio, which is described herein on a volumetric, rather than a mass basis. Low water cement ratio is responsible for improved mechanical properties and for enhanced durability. It is shown, however, that use of a low water cement ratio necessitates either a sacrifice in workability, or the use of high cement content, neither a desirable consequence. The use of water-reducing admixtures is discussed as an alternative. The use of normal-, mid-, and high-range waterreducing admixtures is described in the context of a series of graphs based on the water demand relationships implicit in the ACI 211.1 procedure for proportioning mixtures. By introducing the concept of water-reducer ‘effectiveness’, these graphs can be used to describe the differences among normal, mid-range, and high-range water reducers, and can be used to illustrate the use of water reducers to reduce water content, reduce water cement ratio, and to increase workability.
Causality in the logic of decision

In recent years there has been an active debate between proponents of two different models of rational decision. One model is evidential decision theory, which is characterized by the fact that it holds the principle of maximizing expected utility to be appropriate whenever the states are probabilistically independent of the acts. The other model, causal decision theory, holds that the principle of maximizing expected utility is appropriate whenever the states are causally independent of the acts. The proponents of evidential decision theory include Richard Jeffrey and Ellery Eells, who claim that evidential decision theory has significant advantages over causal decision theory. In this paper I discuss the two main advantages which have been claimed for evidential decision theory, and show that in fact evidential decision theory does not possess either of these advantages.
TH‐A‐217BCD‐10: Feasibility of Performing 2D Mammography Using CNT Source Array Designed for Tomosynthesis

Purpose: Digital breast tomosynthesis (DBT) is the top rival of 2D mammography. Two common approaches to DBT are continuous and step‐and‐shoot tube motion; presenting problems with source motion blur and long scan time, respectively. Stationary DBT (s‐DBT) has the potential to overcome both issues. We recently developed an s‐DBT scanner utilizing a CNT(carbon nanotube) x‐ray source array, and demonstrated its enhanced spatial resolution and faster scanning speed. This work explores the possibility of expanding the capabilities of current CNT s‐DBT technology to 2D mammography when necessary. Methods: A testing chamber was configured to mimic the most recent iteration of the s‐DBT technology. Simulations of heat loading on the tungsten anode were conducted to predict the maximum power the anode could withstand. The minimum goal was to test if a single CNTcathode could output 50mAs in 4s, giving similar exposure of one traditional 2D view. Further testing explored the current limits of the cathodes.Results: Results show that a single CNTcathode can easily reach the minimum requirement for a 2D mammographyimage and can reliably administer up to 50mAs with a 3 second pulse width at 35kVp, which is an equivalent exposure to one 2D mammographyimage.Conclusions: A single CNTcathode in the electrode configuration of the current s‐DBT design can successfully administer enough current to perform a 2D mammography screening image. The heat loading on the anode was sufficient for this purpose, with the limiting factor being the current design of the CNTcathodes. This work is supported by the National Cancer Institute through the Carolina Center for CancerNanotechnology Excellence under grant number U54CA119343 and R01CA134598, the Lineberger Comprehensive Cancer Center and University Cancer Research Fund at UNC
Lens epithelium and radiation cataract. V. Observations on acid phosphatase and meridional row nuclear fragmentation.

Abstract The influence of X-radiation on acid phosphatase activity in differentiating meridional row cells of rat lens epithelia was examined by ultrastructural cytochemistry. X-ray doses of 10–12 Gy (1000–1200 rads) produced clearly observable nuclear and cytoplasmic damage at 13–19 hr postirradiation. In those cells, acid phosphatase reaction product was associated with much of the electron dense material of fragmented nuclei and various parts of the cytoplasm. In addition, many irradiated cells without observable damage were positive for reaction product. The presence of acid phosphatase activity in these otherwise normal-appearing cells is suggestive of more subtle radiation damage than that observed in the more severely damaged cells.
IL-7 comes of age

Kim and colleagues demonstrate that aging is associated with diminished numbers of IL-7Rα–expressing T cells and that these cells have decreased responsiveness to IL-7, with important implications for the clinical development of IL-7 as an immunomodulatory agent. Interleukin 7 (IL-7) is a