cssi/SciSciGPT-SciSciNet huggingface dataset:
A tale of two generations: Maternal skin color and adverse birth outcomes in Black/African American women.

Abstract We examined how sociopolitical context (marked by generational cohort) and maternal skin color interacted to influence preterm delivery (PTD) rates in sample of Black women. Data were from 1410 Black women, ages 18–45 years, residing in Metropolitan Detroit, MI enrolled (2009–2011) in the Life-course Influences on Fetal Environments (LIFE) Study. Because we hypothesized that generational differences marked by changes in the sociopolitical context would influence exposure to racism, we categorized women into two cohorts by maternal birth year: a) Generation X, 1964–1983 and b) Millennial, 1984–1993. Descriptive results showed similar PTD rates by generational cohort, Generation X: 16.3% vs. Millennials: 16.1%. Yet, within each generation, PTD rates varied by women's skin tone (categorized: light, medium, and dark brown). Poisson regression models confirmed a significant interaction between generational cohort and maternal skin tone predicting PTD (P = 0.001); suggesting a salubrious association between light brown skin tone (compared to medium and dark) and PTD for Generation X. However, Millennials with medium and dark brown skin experienced lower PTD rates than their light Millennial counterparts. Research should consider sociopolitical context and the salience of skin tone bias when investigating racial health disparities, including those in perinatal health.
Are CSF CXCL13 concentrations solely dependent on intrathecal production? A commentary on "Chemokine CXCL13 in serum, CSF, and blood-CSF barrier function".

Pilz et al. (Fluids Barriers CNS 17:7; 2020) investigated how CSF CXCL13 concentrations are influenced by CXCL13 serum concentrations and blood-CSF barrier (BCSFB) function, comparing the impact of serum CXCL13 levels and Qalbumin (CSF albumin/serum albumin) on CSF CXCL13 among patients with CNS inflammation categorized as CXCL13 negative, low, medium, or high. Among all CXCL13 groups, their results showed no correlation between CSF CXCL13 concentrations and serum CXCL13 or Qalbumin. The authors argue that, in contrast to other proteins, CXCL13 passage across the BCSFB does not occur, regardless of BCSFB function, and is instead solely influenced by intrathecal production. In contrast to the authors’ findings, in our studies including both non-inflammatory neurological disorders (NIND; n = 62) and multiple sclerosis (MS) patients we observed a significant correlation between serum CXCL13 concentrations and CSF CXCL13 concentrations. We review several observations which may underlie these contrasting results, including (1) the impact of serum CXCL13 concentrations on CSF CXCL13 in patients with lower intrathecal CXCL13 production and thus lower CXCL13 concentrations (i.e. NIND and MS), (2) the proposed diffusion dynamics of the small molecule CXCL13 across the BCSFB, and (3) differing definitions of negative versus elevated CSF CXCL13 concentrations determined by an assay’s relative sensitivity. In conclusion, we argue that for patients with moderately elevated CSF CXCL13 concentrations, serum CXCL13 concentrations influence CSF CXCL13 levels, and thus the appropriate corrections including incorporation of CSF/serum ratios and Qalbumin values should be utilized.
Multi-Season Reproduction and Pastoralist Production Strategies: New Approaches to Birth Seasonality from the South Caucasus Region

Current debates about pastoralists’ role in the development of complex forms of political organization in the ancient Near East and the Caucasus revolve around questions about pastoralist productio...
Three-Dimensional Modeling of the Structural Microenvironment in Post-Traumatic War Wounds.

The development of post-traumatic heterotopic ossification (HO) is a common, undesirable sequela in patients with high-energy (war-related) extremity injuries. While inflammatory and osteoinductive signaling pathways are known to be involved in the development and progression of post-traumatic HO, features of the structural microenvironment within which the ectopic bone begins to form remain poorly understood. Thus, increasing our knowledge of molecular and structural changes within the healing wound may help elucidate the pathogenesis of post-traumatic HO and aid in the development of specific treatment and/or prevention strategies. In this study, we performed high-resolution microscopy and biochemical analysis of tissues obtained from traumatic war wounds to characterize changes in the structural microenvironment. In addition, using an electrospinning approach, we modeled this microenvironment to reconstitute a three-dimensional type I collagen scaffold with non-woven, randomly oriented nanofibers where we evaluated the performance of primary mesenchymal progenitor cells. We found that traumatic war wounds are characterized by a disorganized, densely fibrotic collagen I matrix that influences progenitor cells adhesion, proliferation and osteogenic differentiation potential. Altogether, these results suggest that the structural microenvironment present in traumatic war wounds has the potential to contribute to the development of post-traumatic HO. Our findings may support novel treatment strategies directed towards modifying the structural microenvironment after traumatic injury.
Multiple Testing of Causal Hypotheses

A primary problem in causal inference is the following: From a set of time course data, such as that generated by gene expression microarrays, is it possible to infer all significant causal relationships between the elements described by this data? In prior work [2], we have proposed a framework that combines notions of causality in philosophy, with the algorithmic approaches built on model checking and statistical techniques for multiple hypotheses testing. The causal relationships can be then described in terms of temporal logic formulas, reframing the problem in terms of model checking. The logic used, PCTL, allows description of both the time between cause and effect and the probability of this relationship being observed. Borrowing from philosophy, we define prima facie causes in terms of probability raising, and then determine genuine causality by computing the average difference a prima facie cause makes to the occurrence of its effect, given each of the other prima facie causes of that effect. However, it faces many interesting issues confronted in statistical theories of hypotheses testing, namely, given these causal formulas with their associated probabilities and our average computed differences, instead of choosing an arbitrary threshold, how do we decide which are “significant”? To address this problem rigorously, we use the concepts of multiple hypothesis testing (treating each causal relationship as a hypothesis), and false discovery control. In particular, we apply the empirical Bayesian formulation proposed by Efron in [1]. This method uses an empirical rather than theoretical null, which has been shown to be better equipped for cases where the test statistics are dependent - as may be true in the case of complex causal structures.
Functional Neural Pathways for Vocalization in the Domestic Cat

The domestic cat has been a companion of man for a very long time. However, until very recently, little was known about the structure, function and natural history of the vocalizations of the domestic cat This is particularly surprising as animal vocalizations in general have been the subject of intensive research by ethologists, and very significant advances have been made with respect to the neural mechanisms of avian vocalization (Konishi, 1985: Andrew, 1974).
RSA/Rabin least significant bits are \( \tfrac{1} {2} + \tfrac{1} {{poly \left( {\log N} \right)}} \) secure (Extended Abstract)

We prove that RSA least significant bit is \( \tfrac{1} {2} + \tfrac{1} {{log^c N}} \) secure, for any constant c (where N is the RSA modulus). This means that an adversary, given the ciphertext, cannot guess the least significant bit of the plaintext with probability better than \( \tfrac{1} {2} + \tfrac{1} {{log^c N}} \), unless he can break RSA.
Optical properties of troponin, tropomyosin, and relaxing protein of rabbit skeletal muscle.

Optical rotatory dispersion (ORD), circular dichroism (CD), ultraviolet absorption, the fluorescence of troponin, tropomyosin, and relaxing protein were used as probes to detect structural changes resulting from the binding of troponin with tropomyosin to form a complex called relaxing protein. In the wave length region from 250 to 190 nm, ORD and CD spectra show that all the apparent band positions of the three proteins studied are similar to those reported for helical polypeptides. The helical contents estimated from ORD and CD troughs are 42, 97, and 72% for troponin, tropomyosin, and relaxing protein, respectively. In the ultraviolet region of the ORD and CD spectra, no change was observed in the secondary structure upon complexing troponin and tropomyosin. In addition, a stoichiometry of 1:1 by weight is indicated since a mixture of troponin and tropomyosin yielded a spectrum which superimposes on that observed for relaxing protein. On the other hand, the CD spectra in the aromatic region (300 to 250 nm) indicate that the aromatic chromophores of either troponin or tropomyosin are perturbed. From an over-all change in the band intensities and from the disappearance of the positive 295 nm band upon binding of troponin to tropomyosin, it is suggested that the environment of the aromatic chromophores has been significantly modified. A perturbation associated with the binding of troponin to tropomyosin was also detected in the absorption spectrum. No change in the ionization constants for the phenolic groups of the tyrosine residues was observed upon formation of the relaxing protein. On the other hand, a shift of the fluorescence emission maximum of relaxing protein during storage suggests that tryptophan residues are perturbed in relaxing protein. It is, therefore, concluded that the perturbation of the aromatic residues results from a change in tryptophan rather than in the tyrosine residue environment.
Imagining a Stata / Python Combination

There are occasions when a task is difficult in Stata, but fairly easy in a more general programming language. Python is a popular language for a range of uses. It is easy to use, has many high ]quality packages, and programs can be written relatively quickly. Is there any advantage in combining Stata and Python within a single interface? Stata already offers support for user-written programs, which allow extensive control over calculations, but somewhat less control over graphics. Also, except for specifying output, the user has minimal programmatic control over the user interface. Python can be used in a way that allows more control over the interface and graphics, and in so doing provide a roundabout method for satisfying some user requests (e.g., transparency levels in graphics and the ability to clear the results window). My talk will explore these ideas, present a possible method for combining Stata and Python, and give examples to demonstrate how this combination might be useful.
Model predictive control of apoptosis in mammalian cell cultures

Publisher Summary Model predictive control (MPC) was implemented to control starvation-induced apoptosis in Chinese hamster ovary (CHO) cells. Apoptosis or Programmed Cell Death (PCD) is characterized by enzymatic and cellular machinery in which the cells engage in an orderly pattern of events that lead to death by suicide. In this, classical kinetic models were extended to account for apoptotic cell death. A series of batch-type fermentations were run to obtain a specific apoptotic death rate. The amino acids that played a key role in the onset of apoptosis were identified by performing a neural-network-based sensitivity analysis. By the estimation of the number of viable cells using extended Kalman filter (EKF), the concentration of apoptotic dead cells (PADCs) could be monitored online. The estimated PADCs were used for online model predictive control. Based on the prediction of PADCs two-sample intervals ahead, corrective control actions were taken to minimize apoptotic death in the bioreactor. The manipulated variables were the flow rates of glutamine, cysteine, and tyrosine. The output variable was the concentration of apoptotic dead cells in the bioreactor.
Tornado solutions for semilinear elliptic equations in ℝ²: Applications

We show partial regularity of bounded positive solutions of some semilinear elliptic equations Δu= f(u) in domains of R 2 . As a consequence, there exists a large variety of nonnegative singular solutions to these equations. These equations have previously been studied from the point of view of free boundary problems, where solutions additionally are stable for a variational problem, which we do not assume.
Type 2 diabetes as a protein misfolding disease

Type 2 diabetes (T2D) is a highly prevalent and chronic metabolic disorder. Recent evidence suggests that formation of toxic aggregates of the islet amyloid polypeptide (IAPP) might contribute to β-cell dysfunction and disease. However, the mechanism of protein aggregation and associated toxicity remains unclear. Misfolding, aggregation, and accumulation of diverse proteins in various organs is the hallmark of the group of protein misfolding disorders (PMDs), including highly prevalent illnesses affecting the central nervous system (CNS) such as Alzheimer's disease (AD) and Parkinson's disease (PD). In this review we discuss the current understanding of the mechanisms implicated in the formation of protein aggregates in the endocrine pancreas and associated toxicity in the light of the long-standing knowledge from neurodegenerative disorders associated with protein misfolding.
Guiding team projects for juniors

A semester-long group project course is described. This course teaches design and project management to prepare students for a senior-level design course sequence carried out individually. The rationale for using groups (teams) and a Socratic design approach is discussed. The paper discusses the sequence of topics and activities over the semester including team-building exercises, group in-class exercises, group lab exercises, design review sessions and lectures. The final product evaluation time is discussed. Group dynamics and personality problems as well as final evaluations are also presented. The students' performance relative to others not having taken the course cannot be evaluated at this time since this group of students has not completed the senior design courses. The teachers' assessments are given as well as plans for future changes.
Closed-loop control over wireless networks

This article includes an implementation of an 802.11b wireless control loop with high communication rates and a timing scheme that uses clock driven sensing and actuation with event-driven control. The timing scheme was implemented using standard PCs and an 802.11b peer-to-peer wireless network. The control scheme was scaled up to a multimode multiplant arrangement with coordination among loops. To examine the wireless control loop performance, we use the rotating base variation of the linear inverted pendulum. Using the wireless control loop, we can examine a number of the characteristics of UDP data transmission over 802.11b.
Examining Mathematics Teacher Content Knowledge: Policy and Practice

This study examines mathematics teacher content knowledge in terms of state and national policymaker recommendations, college coursework and the Mathematics Texas Examination of Educator Standards (TExES) score. Results indicate differences between state and national policy recommendations and college degrees in mathematics. A statistically significant negative relationship between college coursework and the test domains was found for Algebra (p = −.456), Geometry (p = −.442), Probability and Statistics (p = −.421), and Discrete Mathematics (p = −.674). Although teacher candidates completed many mathematics courses, the fail rate for the Mathematics TExES was a quarter of teachers. Policymakers are asked to consider the validity for contents test which align poorly with college degrees in mathematics.
Respiration and substrate transport rates as well as reactive oxygen species production distinguish mitochondria from brain and liver

Aberrant mitochondrial function, including excessive reactive oxygen species (ROS) production, has been implicated in the pathogenesis of human diseases. The use of mitochondrial inhibitors to ascertain the sites in the electron transport chain (ETC) resulting in altered ROS production can be an important tool. However, the response of mouse mitochondria to ETC inhibitors has not been thoroughly assessed. Here we set out to characterize the differences in phenotypic response to ETC inhibitors between the more energetically demanding brain mitochondria and less energetically demanding liver mitochondria in commonly utilized C57BL/6J mice. We show that in contrast to brain mitochondria, inhibiting distally within complex I or within complex III does not increase liver mitochondrial ROS production supported by complex I substrates, and liver mitochondrial ROS production supported by complex II substrates occurred primarily independent of membrane potential. Complex I, II, and III enzymatic activities and membrane potential were equivalent between liver and brain and responded to ETC. inhibitors similarly. Brain mitochondria exhibited an approximately two-fold increase in complex I and II supported respiration compared with liver mitochondria while exhibiting similar responses to inhibitors. Elevated NADH transport and heightened complex II–III coupled activity accounted for increased complex I and II supported respiration, respectively in brain mitochondria. We conclude that important mechanistic differences exist between mouse liver and brain mitochondria and that mouse mitochondria exhibit phenotypic differences compared with mitochondria from other species.
Harnessing peer potency: Predicting positive outcomes from social capital affinity and online engagement with participatory websites

This study involved data from a survey of a representative sample of 1417 US Internet users investigating positive outcomes from three types of participatory websites: social networking sites, e-commerce sites, and content communities (i.e. news organizations and content sharing sites). The findings indicate that the experience of flow (intense engagement in and enjoyment of an activity) promotes satisfaction with and affirmation for such websites as well as perceived focused and incidental knowledge-gain from them. Social capital affinity (sympathy marked by community of interest, and likeness based on weak ties) was found to strongly facilitate the experience of flow. Thus, the findings underscore the potency of online peers in terms of enhancing a variety of Internet experiences.
The Fulcher Bands of HD and D 2

First an account is given of the production and photography under high dispersion of the molecular spectra of ${\mathrm{H}}_{2}$, HD and ${\mathrm{D}}_{2}$ from the ultraviolet to the infrared. Besides the HD and ${\mathrm{D}}_{2}$ lines many new ${\mathrm{H}}_{2}$ lines were found. The Fulcher bands ($1s\ensuremath{\sigma}\ifmmode\cdot\else\textperiodcentered\fi{}3p\ensuremath{\pi}^{3}\ensuremath{\Pi}\ensuremath{\rightarrow}1s\ensuremath{\sigma}\ifmmode\cdot\else\textperiodcentered\fi{}2s\ensuremath{\sigma}^{3}\ensuremath{\Sigma}$ transitions) are given and the constants of these bands compared for the three isotopic molecules. One component of the higher vibrational levels of the initial state is predissociated. From this it follows that the heat of dissociation of the normal molecule must lie between 4.43 and 4.52 volts.
On calculating residuated approximations

For an order-preserving map f : L → Q between two complete lattices L and Q, there exists a largest residuated map ρf under f, which is called the residuated approximation of f. Andreka, Greechie, and Strecker introduced the notion of the shadow σf of f Iterations of the shadow are called the umbral mappings. The umbral mappings form a decreasing net that converges to the residuated approximation ρf of f. The umbral number uf of f is the smallest ordinal number α such that the equation \({\sigma^{(\alpha)}_{f} = \rho_{f}}\) holds. In order to speed up the computation of the umbral number uf of f and find some relation between the structure of L and uf, we present the concept of the order skeleton of a lattice \({L, \tilde{L} = L/\sim}\), determined by a certain congruence relation ~ on L where each equivalence class [x] is the maximal autonomous chain containing x. If [x] is finite for each \({x \in L}\), then \({L_{o} := \{ \Lambda [x]\,|\, x \in L \}}\) is a join-subcomplete sub-semilattice of L isomorphic to the order skeleton \({\tilde{L}}\) of L; for every order-preserving mapping f : L → Q from such a lattice L to a complete lattice Q, we define fo : Lo → Q by \({f_{o} := f|_{{L}_{o}}}\) and prove that \({u_{f} = u_{{f}_{o}}}\). For a lattice L with no infinite chains, the order skeleton \({\tilde{L}}\) of L is distributive if and only if the shadow σf of f is residuated for every complete lattice Q and every mapping f : L → Q. Related topics are discussed.
No-hole k -tuple ( r + 1)-distant colorings

Abstract We study the existence and efficiency of the no-hole k-tuple (r + 1)-distant colorings of a graph, or Nkr-colorings. More specifically, we want to assign a set of k positive integers (the k-tuple requirement) to each vertex of a graph such that adjacent vertices must get numbers at least (r + 1) apart (the (r + 1)-distant requirement), and in addition, the set of all used numbers is a consecutive set (the no-hole requirement). The case k = 1 was studied by Roberts (1993) and Sakai and Wang (1993).
Salt intak assessment by questionnaire and urinary sodium excretion

Abstract A questionnaire designed to assess salt intake was distributed to a sample of 113 healthy female subjects. The questionnaire was validated with 36 subjects collecting complete 24-h urine samples (analysed for sodium) for 7 days, along with sing pre-weighed table and cooking salt pots. Intake was well predicted for table salt use (r=0.67), cooking use (r=0.57), nondiscretionary intake (r=0.65), and total salt intake (r=0.61). The test-retest reliability for the estimate of total intake was good (r=0.75). Measured total salt intake for the 36 subjects was found to be 7.4g NaCl/day, with only 11% from discretionary salt use. Mean questionnaire estimates agreed closely with the measured values.
Dietary Management of Milk Intolerance

Purpose: Milk intolerance in young children is one of the commonest food intolerances seen by paediatricians. In principle, the treatment is simple, but the process of dietary elimination, choosing an appropriate milk substitute and maintaining nutritional adequacy, is no easy task. Design: Market survey and discussion. Method: The history, allergenicity, safety, nutritional adequacy, acceptability, availability and cost of all common milk substitutes used in the UK and the nutritional status of children on milk-free diets are reviewed. Results: There is no ideal milk substitute for the treatment of milk intolerance. Soya infant formulas are cheap and palatable, but there are concerns over their relative allergenicity and phytoestrogen concentration, although the health implications of the latter are still unclear. Extensively hydrolysed formulas have been available for over 40 years and are widely used by paediatricians in the UK as a first-line milk substitute in infancy. However, there are few well-con...
Spatial learning deficits in mice lacking A-type K(+) channel subunits

Kv4.2-mediated A-type K(+) channels in dendrites act to dampen back-propagating action potentials, constrain coincidence detection, and modify synaptic properties. Because of naturally high concentrations in the hippocampus, genetic deletion of this protein results in enhanced CA1 dendritic excitability and a broader signal integration time window with potential implications for spatial learning. In this investigation, we tested Kv4.2 knockout mice in the Morris water maze to assess their spatial reference acquisition and recall abilities. These mice demonstrated prolonged latencies and pathlength to reach a hidden platform during learning trials that was correlated to a decreased use of spatial search strategies in favor of repetitive looping. Knockout mice also showed no preference for target areas in recall-based probe trials but were less impaired by a switch in the platform location at the start of reversal learning. We discuss the possibility that these behavior discrepancies may be attributable to an enhancement in synaptic plasticity and loss of selectivity among synaptic pathways bearing different information into the CA1 region. © 2010 Wiley Periodicals, Inc.
Organizational ownership, competitive intensity, and firm performance: An empirical study of the Indian manufacturing sector

Emerging countries are using privatization as a key strategy in their drive to become free market economies. Although these ownership changes are rapidly gaining prominence, the academic literature has been equivocal about the performance benefits of private vs. state ownership. The lack of clarity in findings can be largely traced to the underspecification of the models that prior studies have examined. Specifically, prior studies have mostly ignored the central role of competitive rivalry. This paper proposes a model that centers around the interactive, inseparable effects of ownership and competitive rivalry on firm performance. Results of the empirical examination set in India show that competitive intensity moderates the relationship between ownership and performance. Copyright © 2001 John Wiley & Sons, Ltd.
Moment-Conserving Techniques for Warm Cloud Microphysical Computation. Part II. Model Testing and Results

Abstract A model of an ascending parcel of air is used to evaluate and demonstrate the accuracy and utility of moment-conserving numerical techniques in cloud microphysical simulations. The sensitivity of the results to parameters of the computer code which might affect accuracy is evaluated. Discrepancies in the evolution of radar reflectivity are found to be satisfactorily small since the vertical displacement of equivalent radar reflectivities is shown to be within typical cloud model grid spacings. The collection calculation results are compared to a known solution and the condensation algorithm is tested by a comparison with a Lagrangian simulation. Simulations employing a maritime and two continental CCN distributions illuminate various features of the techniques employed. One of the continental cases is used to show the sensitivity of the evolution of large drops to the values of linear collision efficiency.
A statistical approach to distributed edge sensor detection

Edge sensor detection is often used in identifying regions that are affected by various factors in wireless sensor networks. A statistical methodology based on distributed detection theory and the Neyman-Pearson criterion is developed for edge sensor detection in this research. The input sensor statistics are assumed to be identically independently distributed in our framework. Edge regions and sensors are determined using a hypothesis test, where the observation model for each hypothesis is derived. A sub-optimal distributed detection scheme, which is optimal among detectors having the same test at all local sensors, and the way of choosing the optimal operating point are described. The condition under which the proposed scheme outperforms the optimum detector based on a single sensor is presented. Furthermore, the noisy channel effect is considered, and a method to overcome this noisy effect is addressed. The performance of the proposed distributed edge sensor detection scheme is studied via computer simulation, where the ROC curves are used to demonstrate the tradeoff between the cost (in terms of the sensor density) and detection accuracy.
SC-21TRIM3, A HUMAN ORTHOLOG OF DROSOPHILA BRAT, MAINTAINS ASYMMETRIC CELL DIVISION OF GLIOMA STEM CELLS BY REGULATING c-MYC AND NOTCH1

Glioma stem cells, capable of self-renewal and multipotent differentiation, influence neoplastic growth by a dynamic balance between symmetric and asymmetric cell division. Growth is favored by a shift to symmetric division in which greater numbers of self-renewing cells emerge, as opposed to asymmetric division, which generates one stem and one differentiated cell. Drosophila Brain Tumor (Brat) protein is a critical driver of asymmetric division and differentiation, and neuroblast cells devoid of Brat undergo symmetric cell division to generate self-renewing cells that result in the brat mutant phenotype. Using a brat RNAi driven by the neuroblast specific promoter inscuteable in Drosophila model, we demonstrated accumulation of proliferative neuroblasts using inscuteable driven RFP. brat RNAi driven with eyeless promoter in Drosophila eye also induced eye overgrowth. Reduced Brat in these settings was associated with upregulation of Notch protein, suggesting a suppressive role on Notch signaling by Brat. Brat also has been shown to promote asymmetric cell division through post-transcriptional suppression of dMyc, although detailed mechanisms are lacking. We have shown that TRIM3, a human ortholog of Drosophila brat, is deleted in more than 25% of glioblastomas (GBMs). We have demonstrated that expression of TRIM3 in GBM-derived neurospheres significantly reduces proliferation, neurosphere formation, and the expression of stem cell markers CD133, NESTIN and NANOG. In GBM stem cells, expression of TRIM3 leads to a greater percentage undergoing asymmetric cell division. As with Brat in Drosophila, TRIM3 suppresses c-MYC expression and activity. We provide evidence that TRIM3, an E3 ubiquitin ligase, binds with and ubiquitinates c-MYC protein, resulting in its degradation. Subsequent attenuation of c-MYC expression inhibits proliferation and self-renewal. Altogether, our current data support a critical role of TRIM3 in maintaining asymmetric cell division of glioma stem cells by regulating c-MYC and NOTCH1.
Transport During Hot Embossing Micro-Manufacturing Studied via Stylus Profilometry and SEM

This work investigates processing parameters affecting replicated feature size during hot embossing micro-manufacturing. Silicon micromachined masters were heated and pressed into polymer layers of different thermophysical properties. Imprinting with loads ranging from 20–35 MPa, load rates from 1–15 MPa/sec, load times from 90–115 sec, and imprint temperatures at, below, and above the polymer glass transition temperature (Tg ) replicated features in polymer with varying degrees of conformity. Replicated features were measured by profilometry and inspected by scanning electron microscopy, revealing polymer feature heights ranging from 25–100% conformal matching of silicon master features and polymer feature widths closely matching the period of features on the silicon master. Statistical analysis determined replicated feature height was positively dependent on tip sharpness, master feature height, temperature, and load rate while negatively dependent on master feature width. Replicated feature width was found to depend positively on master feature height and width, temperature, load rate, and load time. Optimization of imprint parameters during hot embossing micro/nano-manufacturing can possibly lead to a high-throughput manufacturing process offering nanometer resolution.Copyright © 2003 by ASME
Three mechanistic steps detected by FRET after presynaptic filament formation in homologous recombination. ATP hydrolysis required for release of oligonucleotide heteroduplex product from RecA.

The Escherichia coli RecA protein promotes DNA strand exchange in homologous recombination and recombinational DNA repair. Stopped-flow kinetics and fluorescence resonance energy transfer (FRET) were used to study RecA-mediated strand exchange between a 30-bp duplex DNA and a homologous single-stranded 50mer. In our standard assay, one end of the dsDNA helix was labeled at apposing 5‘ and 3‘ ends with hexachlorofluorescein and fluorescein, respectively. Strand exchange was monitored by the increase in fluorescence emission resulting upon displacement of the fluorescein-labeled strand from the initial duplex. The potential advantages of FRET in study of strand exchange are that it noninvasively measures real-time kinetics in the previously inaccessible millisecond time regime and offers great sensitivity. The oligonucleotide substrates model short-range mechanistic effects that might occur within a localized region of the ternary complex formed between RecA and long DNA molecules during strand exchange. Re...
Viral respiratory infections in children with technology dependence and neuromuscular disorders.

Background: Viral acute respiratory infections represent a significant cause of morbidity and mortality across all ages, especially in patients with chronic underlying conditions. Although recognized anecdotally, the risks of viral infection to those children with chronic underlying conditions rendering them technology dependent, or to those children with neuromuscular disorders, have not been well studied. Methods: Studies of children with underlying conditions that result in technology dependence and those with neuromuscular disorders who required hospitalization for respiratory syncytial virus infection are reviewed. Additionally surveys of physician perceptions toward risk factors for severe viral illness and prevention in this population of patients are reported. Possible mechanisms to explain the increased risk of disease severity with viral respiratory infections are explored as well. Results: Current or recent use of supplemental oxygen is associated with more severe disease in children with chronic underlying conditions, especially bronchopulmonary dysplasia. Supplemental oxygen use may be a marker for several factors known to increase the severity of viral respiratory illnesses. Children with neuromuscular weakness are also likely to experience more severe disease, most likely resulting from compromised airway clearance. Conclusions: Although the number of children who are technology-dependent or have severe neuromuscular weakness is small, their risk of severe disease after viral respiratory infection may be similar to that of premature infants or other high risk groups. A better understanding of the factors responsible for severe viral disease in these children would help create better strategies for treatment and prevention.
Simple sling incision for the treatment of iatrogenic urethral obstruction.

Abstract Objectives To review a single-institution experience with sling incision to treat urethral obstruction resulting from pubovaginal sling placement. Urethrolysis involving full mobilization of the urethra has traditionally been used to treat urethral obstruction resulting from a pubovaginal sling. Recently, sling incision has been reported to be a technically simpler, less potentially morbid technique to relieve such obstruction. Methods The charts of 14 women with iatrogenic urethral obstruction from pubovaginal slings who were treated with simple sling incision were reviewed. Presenting symptoms and physical findings and outcomes (primarily resolution of obstructive and irritative symptoms, change in postvoid residual volume, and change in continence status) were evaluated. Results Eleven patients had a biologic sling and three a mid-urethral polypropylene mesh sling. All patients had either obstructive or irritative findings or retention and 10 of 14 had an elevated postvoid residual volume. The average follow-up was 12 months. Overall, 13 (93%) of 14 had complete or significant improvement of presenting complaints, and 1 (7%) eventually required formal urethrolysis. Of the 13 with resolution of presenting complaints, 3 had residual irritative symptoms. Although 3 (21%) of 14 had some element of recurrent stress urinary incontinence, only 1 (7%) required treatment. Conclusions Simple sling incision is an effective, technically simple, and safe treatment for women with iatrogenic urethral obstruction after placement of a pubovaginal sling. Its results are comparable to those of formal urethrolysis, and it may be considered as first-line treatment for iatrogenic obstruction after a sling procedure.
CRYSTALLINE INCLUSIONS IN THE NUCLEAR ENVELOPE AND GRANULAR ENDOPLASMIC RETICULUM OF THE FISH SPINAL CORD

Crystalline inclusions were found in the nuclear envelope and granular endoplasmic reticulum of spinal cord oligodendroglia of the common guppy (Poecilia reticulata) and the lungfish (Polypterus enlicheri). A considerably increased incidence of these inclusions was noted in guppies with congenital and hereditary (sex-linked, recessive) lordosis. Identical crystalline inclusions were observed in protoplasmic and fibrous astrocytes, ependymal cells, and capillary endothelial cells of the spinal cord of the lordotic fish. The oligodendroglia in these fish also revealed a prominent alteration of the endoplasmic reticulum and Golgi apparatus, with the accumulation of dense (secretion?) granules and large amounts of electron-opaque material in markedly dilated sacs of the endoplasmic reticulum. The authors postulate that this alteration is caused by a genetic defect in the control mechanism governing the elaboration of this material in the lordotic guppy, with subsequent stasis and crystallization of this material.
On the relaxation of a mismatching spheroid by prismatic loop punching

Keywords: Glass - Fiber Reinforcement ; Silver Compounds ; Titanium Metallography - Inclusions ; Silver Chloride ; Titanium and Alloys Note: Massachusetts Inst of Tech, Cambridge, United States0956716X (ISSN) Reference LMM-ARTICLE-1991-009View record in Scopus Record created on 2006-10-09, modified on 2017-05-10
MCF-7 and T47D human breast cancer cells contain a functional peroxisomal response

Peroxisome proliferator-activated receptors (PPARs) are ligand-activated nuclear receptors that regulate transcription of target genes. Since attempts have been made to correlate the ingestion of high-fat diets, itself a peroxisome proliferator, with the occurrence of breast cancer, we set about to determine if human breast cancer cells contained a functional PPAR. In this report we demonstrate the presence of an mRNA in two breast cancer cell lines (MCF-7 and T47D) which is specifically recognized by a mouse PPARgamma2 probe. Furthermore, in gel shift assays a consensus PPAR response element (PPRE) was specifically bound by nuclear extracts from MCF-7 cells and was further retarded by antibodies raised to mouse PPARgamma. Finally, when transfected with a PPRE-luciferase transcriptional reporter construct, transcription was increased in response to activators of PPAR and its dimmeric partner the retinoic acid X receptor (RXR). These data indicate that peroxisomal proliferators are capable of mediating transcription in human breast cells and suggest the possibility of a physiological role in the breast.
Sintering of nanoceramics

AbstractThere are two challenges in nanoceramic sintering: fully densifying the sintered body and maintaining the sintered grains at <100 nm size. This review examines the fundamental factors underlying nanoceramic sintering and the approaches to effectively utilise the sintering factors to advantage. Nanoceramic sintering techniques are divided into four categories: pressureless sintering, pressure sintering, electrically assisted sintering, and other sintering related techniques. Pressureless sintering has mainly evolved around modifying sintering schedules, improving nanoparticle packing characteristics, and using additives to tailor the diffusion rates. Pressure sintering, which includes hot pressing, hot isostatic pressing, and sinter forging, can effectively achieve full densification for nanostructured ceramics but microstructural inhomogeneity and sintered shape limitation are difficult to overcome. For electrically assisted sintering, many nanoceramics have been sintered to full density with spar...
Comparison of cytotoxicity mediated by human monocyte-macrophages and lymphocytes after prolonged in vitro incubation

Abstract The effect on cytotoxicity of in vitro incubation of lymphocytes (L) and monocytemacrophages (MP) for 2 h or 24 h, either together (unseparated) or separated, was examined. The yield of MP decreased with prolonged incubation while similar numbers of viable L were obtained with 2 h and 24 h incubation. L and MP spontaneous cytotoxicity (SCT) declined with prolonged incubation. L ADCC increased after 24 h incubation of separated and unseparated cells. In contrast, MP ADCC increased only after incubation of L and MP together and not when MP were incubated separately for 24 h. These data support the hypothesis that circulating MP ADCC effector cells, and possibly L ADCC effector cells, are functionally immature, and by interaction with non-adherent mononuclear cells can be made more active or more numerous.
The Nucleus Accumbens as a Potential Target for Central Poststroke Pain

Although deep brain stimulation (DBS) has been found to be efficacious for some chronic pain syndromes, its usefulness in patients with central poststroke pain (CPSP) has been disappointing. The most common DBS targets for pain are the periventricular gray region (PVG) and the ventralis caudalis of the thalamus. Despite the limited success of DBS for CPSP, few alternative targets have been explored. The nucleus accumbens (NAC), a limbic structure within the ventral striatum that is involved in reward and pain processing, has emerged as an effective target for psychiatric disease. There is also evidence that it may be an effective target for pain. We describe a 72-year-old woman with a large right hemisphere infarct who subsequently experienced refractory left hemibody pain. She underwent placement of 3 electrodes in the right PVG, ventralis caudalis of the thalamus, and NAC. Individual stimulation of the NAC and PVG provided substantial improvement in pain rating. The patient underwent implantation of permanent electrodes in both targets, and combined stimulation has provided sustained pain relief at nearly 1 year after the procedure. These results suggest that the NAC may be an effective DBS target for CPSP.
Diagnosis and follow-up of Chlamydia trachomatis infections in the ED

The purpose of this study was to determine the impact on patient care and the cost effectiveness of testing for chlamydial infection in the emergency department. All patients tested for chlamydial infection in three emergency departments between October 1, 1993 and January 31, 1994 were retrospectively reviewed for charges and adequacy of therapy. In one hospital, the effectiveness of a call-back system to enhance proper therapy of inadequately treated patients was evaluated. Of 2,416 test results, 249 were positive, and 197 of these charts were available for review. All 16 male patients were treated appropriately at the initial visit; 105 of 181 female patients were inadequately treated at the initial visit. The charge to identify each patient inadequately treated was $981.22 ($103,000 for 105). Of the 28 inadequately treated patients receiving a follow-up call, 20 sought treatment. The high cost of testing patients cannot be justified without an adequate surveillance system to enhance proper follow-up treatment.
Ionic liquids with ammonium cations as lubricants or additives

A new class of more effective lubricants could lead to huge energy savings. Limited recent literature has suggested potential for using room-temperature ionic liquids as lubricants, however, only a few out of millions (or more) of species possible have been evaluated. In this study, a series of new protic alkylammonium ionic liquids were synthesized by neutralization and metathesis reactions, and have demonstrated promising lubricating properties as neat lubricants or lubricant additives, particularly for use with difficult-to-lubricate metals like aluminum. More than a 30% friction reduction was observed with ammonium-based ionic liquids compared to conventional hydrocarbon oils in reciprocating sliding tests of 52100 bearing steel on aluminum alloy 6061-T6511. The inherent polarity of ionic liquids is believed to provide strong adsorption to contact surfaces and can form a boundary lubricating film leading to friction and wear reductions. Other advantages of ionic liquids include (1) negligible volatility, (2) high thermal stability, (3) non-flammability, and (4) better intrinsic properties that may eliminate the need for more complex and expensive additive packages. With very flexible molecular structures, this new class of lubricants, particularly ammonium-based ionic liquids, can be tailored to fit a variety of applications.
Evidence for gastric intrinsic factor in the eel (Anguilla rostrata).

SummaryBy the everted intestinal sac technique, a crude homogenate of eel gastric mucosa was shown to enhance selectively the vitamin B12 uptake of the distal portion of the eel intestine. The active principal in ESH was nondialyzable and destroyed by boiling for 10 min. Weak binding of vitamin B12 to ESH was demonstrated. These findings suggest that a rudimentary intrinsic factor mechanism for vitamin B12 asborption is present in the eel.
An effective thermal circuit model for electro-thermal simulation of SOI analog circuits

A physics-based thermal circuit model is developed for electro-thermal simulation of SOI analog circuits. The circuit model integrates a non-isothermal device thermal circuit with interconnect thermal networks and is validated with high accuracy against finite element simulations in different layout structures. The non-isothermal circuit model is implemented in BSIMSOI to account for self-heating effect (SHE) in a Spice simulator, and applied to electro-thermal simulation of an SOI cascode current mirror constructed using different layouts. Effects of layout design on electric and thermal behaviors are investigated in detail. Influences of BOX thickness are also examined. It has been shown that the proposed non-isothermal approach is able to effectively account for influences of layout design, self-heating, high temperature gradients along the islands, interconnect temperature distributions, thermal coupling, and heat losses via BOX and interconnects, etc., in SOI current mirror structures. The model provides basic concepts and thermal circuits that can be extended to develop an effective model for electro-thermal simulation of SOI analog ICs.