cssi/SciSciGPT-SciSciNet huggingface dataset:
Fixation techniques in revision spine surgery

Abstract The purpose of this chapter is to provide a detailed description of the intra-operative technical steps required for advanced reconstructive procedures used for revising failed or incomplete spine surgery. There is a growing incidence of primary, and with it, revision spine surgery. Fixation often becomes a challenge with increasing population age, comorbidities, and multiple attempts at instrumentation. Herein we detail: screw cementation, quad rod constructs, dural scar resection, PJK prevention, and navigation and robotics. This work provides working descriptions of techniques that may be of use to practitioners of complex spine surgery.
Topological complexity of unordered configuration spaces of certain graphs

Abstract The unordered configuration space of n points on a graph Γ, denoted here by UC n ( Γ ) , can be viewed as the space of all configurations of n unlabeled robots on a system of one-dimensional tracks, which is interpreted as a graph Γ. The topology of these spaces is related to the number of vertices of degree greater than 2; this number is denoted by m ( Γ ) . We discuss a combinatorial approach to compute the topological complexity of a “discretized” version of this space, UD n ( Γ ) , and give results for certain classes of graphs. In the first case, we show that for a large class of graphs, as long as the number of robots is at least 2 m ( Γ ) , then TC ( UD n ( Γ ) ) = 2 m ( Γ ) + 1 . In the second, we show that as long as the number of robots is at most half the number of vertex-disjoint cycles in Γ, we have TC ( UD n ( Γ ) ) = 2 n + 1 .
The effect of transfer to adult transplant care on kidney function and immunosuppressant drug level variability in pediatric kidney transplant recipients.

Adolescent age at time of transplant has been recognized as a risk factor for renal allograft loss. Increased risk for graft failure may persist from adolescence to young adulthood. Transfer of care is hypothesized as a risk factor for non-adherence and graft loss. We explored whether kidney allograft function declined at an accelerated rate after transfer of care to adult transplant centers and whether coefficient of variation of tacrolimus (CV TAC) trough levels predicted allograft loss. Single-center, retrospective chart review was performed for pediatric kidney transplant recipients who received transplants between 1999 and 2011. Change in eGFR pre- and post-transfer was performed via a linear mixed-effects model. CV TAC was calculated in transplant recipients with TAC data pre- and post-transfer. t test was performed to determine the difference between means of CV TAC in subjects with and without allograft loss following transfer of care. Of the 138 subjects who transferred to adult care, 47 subjects with data pre- and post-transfer demonstrated a decrease in the rate of eGFR decline post-transfer from 8.0 mL/min/1.73 m2 per year to 2.1 mL/min/1.73 m2 per year, an ~80% decrease in eGFR decline post-transfer (P = 0.01). Twenty-four subjects had CV TAC data pre- and post-transfer of care. Pretransfer CV TAC for subjects with allograft loss post-transfer was significantly higher than in subjects without allograft loss (49% vs 26%, P < 0.05). Transfer of care was not independently associated with acceleration in eGFR decline. CV TAC may aid in identifying patients at risk for allograft loss post-transfer.
Sexual Harassment Prevention after #MeToo: Employers’ need to Reevaluate

The complex problem of workplace sexual harassment has now been put in sharper focus by the publicity of high-profile cases and the advent of the #MeToo movement, both of which have educated victims and motivated them to assert their civil rights. Employers can anticipate an increase in reported incidents and will need to reevaluate the sufficiency of their current anti-harassment policies, reporting procedures and support training to prevent sexual harassment. Employers’ should not stop there but should include efforts to create a culture of respect to prevent incidences of sexual harassment in the first place.
Limited Utility of Circulating Cell-Free DNA Integrity as a Diagnostic Tool for Differentiating Between Malignant and Benign Thyroid Nodules With Indeterminate Cytology (Bethesda Category III)

Background: Analysis of plasma circulating cell-free DNA integrity (cfDI) has emerged as a promising tool in the diagnosis of malignant vs. benign tumors. There is limited data on the role of cfDI in thyroid cancer. The goal of this study was to analyze cfDI as a biomarker of malignancy in patients with cytologically indeterminate thyroid nodules. Methods: The cfDI was measured in the plasma of patients with cytologically indeterminate thyroid nodules. All patients underwent plasma collection within 24-72 h before surgical treatment for thyroid nodules. Additionally, samples were collected from seven patients via the vein draining the thyroid and peripheral vein during surgery. Quantitative real-time PCR was performed on the isolated cell-free DNA using two different primer sets (115 and 247 bp) to amplify consensus ALU sequences. The cfDI was calculated as the ratio of ALU247 to ALU115. Results: All data are given as median [25th-75th percentile]. The study group consisted of 67 patients with 100 nodules, 80.6% (54/67) women, aged 43 [33-60] years. There was no difference in cfDI between 29 patients with benign nodules (0.49 [0.41-0.59]) and 38 patients with malignant lesions (0.45 [0.36-0.57], p = 0.19). There was no difference in cfDI in the vein draining the thyroid (0.47 [0.24-1.05]) and peripheral vein (0.48 [0.36-0.56], p = 0.44). In comparison to thyroid cancer patients, patients with benign nodules were characterized by significantly higher concentrations of ALU115 (1,064 [529-2,960] vs. 411 [27-1,049] ng/ml; p = 0.002) and ALU247 (548 [276-1,894] vs. 170 [17-540] ng/ml; p = 0.0005), most likely because benign tumors were larger (3, [1.8-4.1 cm]) than malignant lesions (0.7 [0.23-1.45], p < 0.0001). Women had significantly lower cfDI (0.45 [0.27-0.54]) than men (0.56 [0.44-0.8], p = 0.011). Conclusion: The cfDI measured in the vein draining the thyroid is similar to the cfDI measured in the antecubital vein, validating cfDI measurements by peripheral liquid biopsy. Analysis of cfDI needs to be stratified by patients gender. In contrast to its diagnostic utility in aggressive cancers, cfDI has limited utility as a biomarker of malignancy in cytologically indeterminate thyroid nodules.
Action Fluency Facilitates Perceptual Discrimination

Perception and action interact in nearly every moment of daily life. Previous studies have demonstrated not only that perceptual input shapes action but also that various factors associated with action-including individual abilities and biomechanical costs-influence perceptual decisions. However, it is unknown how action fluency affects the sensitivity of early-stage visual perception, such as orientation. To address this question, we used a dual-task paradigm: Participants prepared an action (e.g., grasping), while concurrently performing an orientation-change-detection task. We demonstrated that as actions became more fluent (e.g., as grasping errors decreased), perceptual-discrimination performance also improved. Importantly, we found that grasping training prior to discrimination enhanced subsequent perceptual sensitivity, supporting the notion of a reciprocal relation between perception and action.
Outpatient Management of COVID-19: Rapid Evidence Review

Common presenting symptoms of coronavirus disease 2019 include fever, dry cough, shortness of breath, and fatigue. However, patients may have a wide range of symptoms representing a spectrum of mild to severe illness. Symptoms in children tend to be milder and may include fever, cough, and feeding difficulty. The incubation period is two to 14 days, although symptoms typically appear within five days of exposure. Multiple testing modalities exist, but infection should be confirmed by polymerase chain reaction testing using a nasopharyngeal swab. There are no evidence- based treatments appropriate for use in the outpatient setting; management is supportive and should include education about isolation. In hospitalized patients, remdesivir should be considered to reduce time to recovery, and low-dose dexamethasone should be considered in patients who require supplemental oxygen. Overall, 85% of patients have mild illness, whereas 14% have severe disease requiring hospitalization, including 5% who require admission to an intensive care unit. Predictors of severe disease include increasing age, comorbidities, lymphopenia, neutrophilia, leukocytosis, low oxygen saturation, and increased levels of C-reactive protein, d-dimer, transaminases, and lactate dehydrogenase.
Mindsets in the clinic: Applying mindset theory to clinical psychology

Beliefs about the malleability of attributes, also known as mindsets, have been studied for decades in social-personality psychology and education. Here, I review the many applications of mindset theory to clinical psychology and psychotherapy. First, I review social psychological and cognitive neuroscience evidence that mindsets and mindset-related messages are, to a large extent, focused on emotional tolerance. Specifically, the growth mindset, or the belief that attributes are malleable, encourages confronting and tolerating anxiety, frustration, and disappointment in healthy and adaptive ways that promote resilience, whereas the fixed mindset and related messages discourage the experience of these emotions and often leads to helplessness. Second, I review the emerging research on the anxiety mindset and discuss its relevance to clinical work. A model is proposed illustrating connections between mindsets, emotion regulation strategies, treatment preferences, and outcomes. Case examples are used to illustrate practical applications. I conclude that mindsets can inform psychotherapy, research, and public policy.
Psychological factors among Appalachian women with abnormal Pap results.

PURPOSE Women who receive an abnormal Pap result may experience negative psychological factors. The purpose of this study is to assess the baseline occurrence of negative psychological factors and evaluate the relationships between psychological factors and demographic characteristics among Appalachian women who received abnormal Pap results. METHODS We conducted a secondary analysis of data collected from Appalachia Kentucky women (N = 521) ages ≥18 enrolled in an intervention. Data included sociodemographics, Beck depression and anxiety inventories, fatalism, and personal control measures. Multiple variable logistic regression was used to investigate the association between demographics and psychological factors. FINDINGS Participants were predominantly White (96.2%), with mean age 28.93 ± 11.03 years, and the majority (77%) had yearly income below $20,000. Depression was reported by 34.6% (n = 173); 10% (n = 50) experienced moderate or severe anxiety; 20.6% (n = 107) had fatalistic beliefs; and 55.1% (n = 289) believed they lacked personal control over cancer. Women with lower income had higher occurrence of depression (P = .003). Women with moderate to severe anxiety were significantly older than those with low to moderate depression (34.44 vs 28.34, P < .001). Controlling for other variables, as age increased, the odds of fatalistic beliefs increased, OR (95%) = 1.042 (1.022, 1.062). When education level increased, the odds of fatalistic beliefs decreased, OR (95%) = 0.873 (0.800, 0.952). CONCLUSIONS Given the high occurrence of depression, anxiety, and fatalistic beliefs among this population, health care providers should assess for underlying mental health diagnoses and psychological distress during each patient encounter and provide recommendations to address them.
Improved inference of tandem domain duplications

MOTIVATION Protein domain duplications are a major contributor to the functional diversification of protein families. These duplications can occur one at a time through single domain duplications, or as tandem duplications where several consecutive domains are duplicated together as part of a single evolutionary event. Existing methods for inferring domain-level evolutionary events are based on reconciling domain trees with gene trees. While some formulations consider multiple domain duplications, they do not explicitly model tandem duplications; this leads to inaccurate inference of which domains duplicated together over the course of evolution. RESULTS Here, we introduce a reconciliation-based framework that considers the relative positions of domains within extant sequences. We use this information to uncover tandem domain duplications within the evolutionary history of these genes. We devise an integer linear programming approach that solves our problem exactly, and a heuristic approach that works well in practice. We perform extensive simulation studies to demonstrate that our approaches can accurately uncover single and tandem domain duplications, and additionally test our approach on a well-studied orthogroup where lineage-specific domain expansions exhibit varying and complex domain duplication patterns. AVAILABILITY AND IMPLEMENTATION Code is available on github at https://github.com/Singh-Lab/TandemDuplications. SUPPLEMENTARY INFORMATION Supplementary data are available at Bioinformatics online.
Dynamic Channel Allocation for Real-Time Connections in Highway Macrocellular Networks

The wide deployment of multimedia services in third generation wireless networks will require handoff designs that can simultaneously reduce the blocking probability of handoff requests and decrease the handoff delay. Reducing the handoff blocking probability is needed to prevent frequent call dropping of real-time VBR/VCR connections and decreasing the delay associated with handoff is needed to prevent QoS degradation for multimedia traffic. In this paper, we present a channel assignment/reassignment scheme for highway cellular networks that achieves both requirements. The scheme can be used to deliver real-time data to a large segment of global highways, namely, highways in which the radio channels used in a given cell cannot be simultaneously used in the two neighboring cells to its left and to its right. The scheme possesses the desirable features of real-time algorithms: the execution time per handoff request has a constant time complexity, the number of transmitted messages per request is small, and the space overhead is also O(1). The scheme uses a non-compact initial assignment of nominal channels to neighboring cells and utilizes a set of pointers in each base station to implement an efficient channel assignment and reassignment strategy. The resulting approach greatly simplifies the selection process and avoids the expensive computation and message exchanges typically needed by dynamic channel allocation schemes. The low communication overhead of the scheme can be further reduced via control thresholds. Performance simulation results show that the scheme achieves low blocking probability and is therefore suitable for handling handoffs of real-time connections in highway cellular networks.
Director Communications and the Uneasy Relationship Between the Fiduciary Duty of Disclosure and the Anti-Fraud Provisions of the Federal Securities Laws

This Article addresses a conflict between the fiduciary duty of disclosure under state law and the anti-fraud provisions of the federal securities laws. In the Securities Litigation Uniform Standards Act of 1998, Congress balanced the federal interest of discouraging frivolous securities litigation against the need of the states to regulate the conduct of corporate directors. In the Uniform Act, Congress preempted most state securities fraud class actions, but also specifically preserved state claims based on the fiduciary duty of disclosure as enunciated by the Delaware courts at the time of enactment. At that time, the Delaware courts had limited the fiduciary duty of disclosure to communications made when the corporation was seeking some sort of shareholder action, such as a shareholder's decision to vote or tender his securities. In other words, the fiduciary duty of disclosure would not attach if a misleading statement appeared in a corporate press release or public document made to the market generally. Congress drafted the so-called "Delaware carve-out" to reflect this distinction: under the Uniform Act, actions based on the fiduciary duty of disclosure are preserved only if shareholder action has been requested by the corporation. After the passage of the Uniform Act, however, the Delaware Supreme Court expanded the scope of the fiduciary duty of disclosure to reach all communications made by directors, whether shareholder action had been requested or not. Thus, following the Malone v. Brincat case, the Uniform Act preempts certain class actions based on a breach of fiduciary duty of disclosure, prohibiting the Delaware courts from holding directors of Delaware corporations liable for even flagrant breaches of their fiduciary duty of disclosure. This Article argues that Congress should amend the Delaware carve-out to preserve all actions based on a breach of fiduciary duty of disclosure, including actions based on misleading communications made to the market generally. It demonstrates that this approach will protect Delaware's strong interest in regulating the conduct of directors of corporations organized under its corporate statute without undercutting the important policies of the Uniform Act.
Complexity Theory of Neural Networks and Classification Problems

Multilayered, feedforward neural network techniques have been proposed for a variety of classification and recognition problems ranging from speech to sonar signal processing problems. It is generally assumed that the underlying application does not need to be modeled very much and that an artificial neural network solution can be obtained instead by training from empirical data with little or no a priori information about the application. We argue that the right network architecture is fundamental for a good solution to exist and the class of network architectures forms a basis for a complexity theory of classification problems. An abstraction of this notion of complexity leads to ideas similar to Kolmogorov's minimum length description criterion, entropy and k-widths. We will present some basic results on this measure of complexity. From this point of view, artificial neural network solutions to real engineering problems may not ameliorate the difficulties of classification problems, but rather obscure and postpone them. In particular, we doubt that the design of neural networks for solving interesting nontrivial engineering problems will be any easier than other large scale engineering design problems (such as in aerodynamics and semiconductor device modeling).
Information Acquisition Through Customer Voting Systems

We study the use of customer voting systems that enable information acquisition from strategic customers to improve pricing and product development decisions. In these systems, the firm presents customers with a product design and gives them the opportunity to cast a vote on this design, a vote that has costs and benefits. For example, voting may be cumbersome, but those that vote in favor of a design may be eligible for a discount if and when the design gets developed. Customers vote and the firm interprets the voting outcome to discern customer interest in the product, and to advise on further development and/or pricing of the product. We model the interactions between the rm and strategic customers in such systems as a game of incomplete information with voting embedded as a subgame. Our analysis shows that the design and effectiveness of a voting system depends crucially on the intended use of the acquired information. When the acquired information is used to advise on development decisions, where rm and customer interests are aligned, voting systems that reward voters with discounts on subsequent purchase of products, in effect incentivizing voting in favor of products, can elicit information from customers and improve profit. On the other hand, when the information is used to set prices, a decision where firm and customer interests are misaligned, such systems are ineffective. In these cases, voting systems that effectively incentivize customers to vote against products or those that partially limit the firm's future price flexibility should instead be used to acquire information. While both solutions improve firm profit, the former is preferred for high-value products, while the latter is preferred when voting involves less effort. Based on data for two representative products in the home decor industry, we find that these systems may increase gross product profits by up to 50% for development and by 20-30% for pricing.
StarLight: Next-Generation Communication Services, Exchanges, and Global Facilities

Abstract Communication services, architecture, and technologies are rapidly evolving in response to application demand and research innovation. These changes are motivating a fundamentally new approach to the design and provisioning of services, facilities, and infrastructure. Traditionally, such resources have been designed and implemented as centralized fixed utility services, with almost no options for specialization and customization, especially by processes at the network edge. Supporting infrastructure has been created and deployed much like buildings are constructed, using a set of highly defined plans, resulting in hardened structures intended to exist basically unchanged for many years. However, this approach leads to severe restrictions on the creation, deployment, enhancement, and customization of services. Furthermore, this approach does not recognize the inherent potential of digital resources for affecting ongoing improvements through rapid continual change and for specialization and customization. Consequently, a new communication design model is being created, implemented in prototype, and placed into production at select sites around the world. This new model is based on multiple emerging trends in advanced network research. This model supports a much broader range of communication services than traditional systems and highly versatile functionality by providing a structural programmable framework. This structure encapsulates network resources as addressable modules that can be discovered, integrated, and customized to create many different types of communication services in advance or dynamically, in direct response to changing requirements.
Glass Sealing in Planar SOFC Stacks and Chemical Stability of Seal Interfaces

In intermediate temperature planar SOFC stacks, the interconnect, which is typically made from cost-effective oxidation resistant high temperature alloys, is typically sealed to the ceramic PEN (Positive electrode-Electrolyte-Negative electrode) by a sealing glass. To maintain the structural stability and minimize the degradation of stack performance, the sealing glass has to be chemically compatible with the PEN and alloy interconnects. In the present study, the chemical compatibility of a barium-calcium-aluminosilicate (BCAS) based glass-ceramic (specifically developed as a sealant in SOFC stacks) with a number of selected oxidation resistant high temperature alloys, as well as the YSZ electrolyte, was evaluated. This paper reports the results of that study, with a particular focus on Crofer22 APU, a new ferritic stainless steel that was developed specifically for SOFC interconnect applications.
High consequence systems phenomenological characterization: A tutorial

Effective and efficient risk management processes include the use of modeling and simulation during the concept exploration phase as part of the technology and risk assessment activities, with testing and evaluation tasks occurring in later design development phases. However, some safety requirements and design architectures may be dominated by the low probability/high consequence, previously unknown or uncharacterized vulnerabilities that require very early testing to characterize and efficiently mitigate. Failure to address these unique risks has led to catastrophic systems failures including the Space Shuttle Challenger, Deepwater Horizon, the Fukushima nuclear reactor, and Katrina levee failures. Discovering and addressing these risks later in the design and development process can be very costly or even lead to project cancellation. This paper presents a framework for the risk management process adoption of early hazard phenomenology testing to inform the technical risk assessment, requirements definition, and conceptual design. A case study of the lightning design vulnerability of the insensitive high explosives being used in construction, demolition, and defense industries will be presented to examine the impact of this vulnerability testing during the concept exploration phase of the design effort. ©2013 Wiley Periodicals, Inc. Syst Eng 16:
Pedestrian evacuation simulation

With the recent 9--11 catastrophe many questions arose about the WTC's building evacuation procedures. Later it was revealed that elevator malfunctions and poorly planned alternate exit routes had contributed to high number of losses of life on that day. The Stationhouse fire in Warwick, RI, in 2003, also provoked the rise of interest in evacuation studies after video footage confirmed that the lack of safety exits and poor placement and marking of the existing ones had cost the lives of dozens of Rhode-Islanders. These and other incidents, like the Chicago Nightclub Fire, have made corporations such as the Ryan Center and T. F. Green Airport decide to research pedestrian evacuation in hazardous and non-hazardous scenarios in the hope of developing safer and more effective evacuation routes for existing building, and safer buildings in the future.
Downscaling humidity with Localized Constructed Analogs (LOCA) over the conterminous United States

Humidity is important to climate impacts in hydrology, agriculture, ecology, energy demand, and human health and comfort. Nonetheless humidity is not available in some widely-used archives of statistically downscaled climate projections for the western U.S. In this work the Localized Constructed Analogs (LOCA) statistical downscaling method is used to downscale specific humidity to a 1°/16° grid over the conterminous U.S. and the results compared to observations. LOCA reproduces observed monthly climatological values with a mean error of ~0.5 % and RMS error of ~2 %. Extreme (1-day in 1- and 20-years) maximum values (relevant to human health and energy demand) are within ~5 % of observed, while extreme minimum values (relevant to agriculture and wildfire) are within ~15 %. The asymmetry between extreme maximum and minimum errors is largely due to residual errors in the bias correction of extreme minimum values. The temporal standard deviations of downscaled daily specific humidity values have a mean error of ~1 % and RMS error of ~3 %. LOCA increases spatial coherence in the final downscaled field by ~13 %, but the downscaled coherence depends on the spatial coherence in the data being downscaled, which is not addressed by bias correction. Temporal correlations between daily, monthly, and annual time series of the original and downscaled data typically yield values >0.98. LOCA captures the observed correlations between temperature and specific humidity even when the two are downscaled independently.
Skin, Biomechanics of

This article provides a background description of skin and discusses the mechanical properties of skin. Keywords: skin; biomechanics; microstructure; collagen; elastin; anisotropy
Two different effects of mutation on the binding of folate antagonists by a microbial dihydrofolate reductase.

Abstract Two types of mutant dihydrofolate reductase (5,6,7,8-tetrahydrofolate: NADP + oxidoreductase, EC 1.5.1.3) with altered inhibitor binding have been identified with antifolate-resistant strains of Diplococcus pneumoniae . One class (mutant Type A) exhibits a small decrease in affinity for 4-aminofolate analogs (about 3-fold higher average K i ). The estimated K i for binding of aminopterin and amethopterin by the wild-type enzyme is somewhat less than 10 −10 . There is also a small decrease in affinity for dihydrofolate (1.5–2 fold higher K m ) and an increase in affinity for NADPH (2–4-fold lower K m ). The mutations which determine this class of enzyme are distributed at 4 distinct sites within the dihydrofolate reductase structural gene. A second class (mutant Type B) of mutant enzyme shows a marked decrease in affinity for 4-aminofolate analogs (50–100-fold higher K i ) and a shift in pH optimum for dihydrofolate reduction from 7.3 to 6.7. The mutations, which determine these enzymic effects, are clustered at one region of the structural gene. Binding of folate to the wild-type enzyme was almost 10 6 -fold less than that of the 4-aminofolates, aminopterin and amethopterin. Binding of folate by mutant and wild-type enzymes was not dependent on pH within the range of 5.9 to 9.5. Binding of aminopterin by the wild-type enzyme was independent of pH within the range of 5.9 to 7.4, but decreased at pH levels above and below this range. The binding by a B mutant enzyme shows a somewhat greater dependence on ph within the same range. A discussion of these results in terms of the possible mode of binding of the pyrimidine moiety of these pteridine analogs is presented. Two related 2,4-diaminopyrimidines (NSC-110 180 and NSC-110 191) bearing both aminobenzoyl and aspartyl moieties were bound to the mutant and wild-type enzymes to nearly the same extent as the 4-aminofolates. The 5-aryl diaminopyridine, trimethoprim ( K i = 3.7·10 −9 ) was bound better than the related pyrimethamine ( K i = 2.46·10 −8 ) to A mutant and wildtype enzymes. Binding to a B mutant enzyme was reduced only 5-fold for pyrimethamine, but 100-fold for trimethoprim.
One of Nature's Macromolecular Machines Demystified

Organisms in nature use sophisticated molecular machinery to synthesize polypeptides with useful medicinal properties. In her Perspective, Stubbe discusses work by Li et al ., published in the same issue (p. 1188), in which the components involved in the synthesis of microcin B17 by Escherichia coli are purified. Understanding the details of how such posttranslationally modified peptides are made may lead to the development of other novel molecules with antibiotic and antitumor properties.
Nonelastic Scattering Cross Sections for Fast Neutrons

Measurements have been made of the nonelastic cross sections of neutrons in Be, C, Al, Ti, Cr, Fe, Ni, Cu, Ag, Sn, Pb, and Bi. These cross sections include all processes except elastic scattering. The experiments have been carried out with monoenergetic neutrons of 3.5, 4.7, 7.1, 12.7, and 14.1 Mev. The neutrons were produced with a Van de Graaff accelerator using the nuclear reactions: ${\mathrm{T}}^{3}(p, n){\mathrm{He}}^{3}$, $\mathrm{D}(d, n){\mathrm{He}}^{3}$, and ${\mathrm{T}}^{3}(d, n){\mathrm{He}}^{4}$. Cross sections were determined from transmissions through spherical shells which were 3.8 cm in radius and 2 cm thick. A new type of neutron detector which gives energy information about neutrons and is insensitive to $\ensuremath{\gamma}$ radiation was placed at the center of the spherical shell and was used as a biased detector of neutrons. The results of these experiments show that the nonelastic neutron cross section for 12.7- and 14.1-Mev neutrons is nearly geometrical and is closely approximated by $\ensuremath{\sigma}=\ensuremath{\pi}{(R+\ensuremath{\lambda})}^{2}$, where $R=1.4\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}13}{A}^{\frac{1}{3}}$. The nonelastic cross sections are roughly constant in the energy range 5 to 14 Mev; below about 5 Mev the cross sections begin to decrease.The elastic cross sections can be obtained by subtracting the nonelastic cross sections from the total cross sections. The variations with energy of the nonelastic and elastic cross sections are quite different.Data with 12.7-Mev neutrons and low counter bias, give the relative number of $\ensuremath{\gamma}$ rays given off per inelastic collision of these neutrons. The number of $\ensuremath{\gamma}$ rays decreases rapidly with increasing atomic number and there are less than 5% as many $\ensuremath{\gamma}$ rays from Bi as from Al, Ti, Cr, and Fe.
Finite transmission zeros of linear time-invariant generalized state space systems

In this paper, the problem of finding inputs which generate zero outputs in linear time-invariant control systems of the form E(dx/dt) = Ax + Bu is considered where E and A are not necessarily square matrices. This problem is solved using the theory of matrix generalized inverses.
Developing A Knowledge-Base Of Phonetic Rules

This project explored a system for developing a knowledge-base of phonetic rules for use in a subsequent larger project for working with the speech impaired. The overall project needs several support knowledge bases including one for "normal" phonemes. The concern here was on developing a learning system for constructing this, incorporating the pronunciations of a range of normal speakers. Thirteen speakers were used, training the system on the 17 vowel sounds. The system was developed on a microcomputer (PC) which is likely to be the most readily available machine to users of the overall system. The results were partially successful - suggestions for further work and improvement are discussed.
Constraints on the Coevolution of Bacteria and Virulent Phage: A Model, Some Experiments, and Predictions for Natural Communities

One view of the coevolution of parasites and their hosts is that of a gene-for-gene arms race between host defenses and parasite counterdefenses. We have incorporated mutations into a model of the ecological interactions between bacteria and virulent phage to determine rates of mutation that would be consistent with this scenario. The model assumes an open habitat (e.g., a chemostat) in which virulent phage and sensitive bacteria can coexist. Equilibrium densities of bacteria and phage are inversely proportional to the efficiency with which phage irreversibly adsorb to their hosts. The absolute rate at which mutations appear is proportional to the product of habitat size, population density, rate of increase, and mutation rate. The bacterium Escherichia coli B readily evolved resistance to virulent phage T4 in our chemostat experiments. Approximately 100 h was required for the appearance, establishment, and attainment of a resource-limited population of these T4-resistant mutants; this time period is clos...
The Catalytic Role of Glutamate 151 in the Leucine Aminopeptidase from Aeromonas proteolytica

Glutamate 151 has been proposed to act as the general acid/base during the peptide hydrolysis reaction catalyzed by the co-catalytic metallohydrolase from Aeromonas proteolytica (AAP). However, to date, no direct evidence has been reported for the role of Glu-151 during catalytic turnover by AAP. In order to elucidate the catalytic role of Glu-151, altered AAP enzymes have been prepared in which Glu-151 has been substituted with a glutamine, an alanine, and an aspartate. The Michaelis constant (K(m)) does not change upon substitution to aspartate or glutamine, but the rate of the reaction changes drastically in the following order: glutamate (100% activity), aspartate (0.05%), glutamine (0.004%), and alanine (0%). Examination of the pH dependence of the kinetic constants k(cat) and K(m) revealed a change in the pK(a) of a group that ionizes at pH 4.8 in recombinant leucine aminopeptidase (rAAP) to 4.2 for E151D-AAP. The remaining pK(a) values at 5.2, 7.5, and 9.9 do not change. Proton inventory studies indicate that one proton is transferred in the rate-limiting step of the reaction at pH 10.50 for both rAAP and E151D-AAP, but at pH 6.50 two protons and general solvation effects are responsible for the observed effects in the reaction catalyzed by rAAP and E151D-AAP, respectively. Based on these data, Glu-151 is intrinsically involved in the peptide hydrolysis reaction catalyzed by AAP and can be assigned the role of a general acid and base.
A parametric study of guided mechanical waves in windshields: a three-layer laminated structure

A parametric study of guided mechanical wave propagation in laminated safety glass (windshields) is presented. Laminated safety glass is considered a three layered structure modeled as a viscoelastic layer bonded by two elastic layers, i.e., glass plates. The interface between each of the two bonded layers is modeled as a bed of longitudinal and shear linear springs. The spring constants are estimated using surface analysis in conjunction with atomic force microscopy and profilometer analysis. Attenuation due to material absorption of the viscoelastic interlayer is considered while calculating the dispersion curves for the system. The dependence of phase and energy velocities, attenuation, and resonance frequencies, upon variations of material properties (e.g., modulus of elasticity, Poisson’s ratio, and longitudinal and shear ultrasonic material attenuation) is discussed. The relative physical dimensions (i.e., layer thickness variation of each layer) influence upon guided wave behavior is also presented and discussed. Results are applicable to any similar three-layer laminated structure.
Sperm maturation in the male reproductive tract: development of motility.

Rabbit spermatozoa were removed from various levels of the male reproductive tract. They were examined in Hanks' solution at room temperature with a phase contrast microscope and their motility characteristics were recorded cinematographically. Spermatozoa from the seminiferous tubules and ductuli efferentes show weak, vibratory movements with no forward progress. Little change in motility occurs until the sperm reach the flexure of the caput epididymidis where some are capable of moving more vigorously in a circular fashion. Samples from the distal caput epididymidis show a sudden increase in sperm activity and a consistent pattern of tight, circular movement. As the sperm traverse the corpus epididymidis, increasing numbers show progressive, forward movement with longitudinal rotation. The proportion of such sperm becomes significant only in samples from the upper cauda epididymidis and more distal regions. Sperm from the ductus deferens rarely retain the circular movement. It is concluded that rabbit spermatozoa undergo a distinct sequence of changes in their swimming movements as they mature in the epididymis. A similar change was noted in epididymal spermatozoa from the rat and guinea pig suggesting that this process is fundamental to sperm maturation in several species.
Electron Spin Resonance Absorption in Metals. I. Experimental

The electron spin resonance absorption in metals was investigated at 300 and 9000 Mc/sec, in the temperature range from 4\ifmmode^\circ\else\textdegree\fi{}K to 296\ifmmode^\circ\else\textdegree\fi{}K. The metals investigated were: Li, Na, K, Be, Mg, Al, Pd, W. Resonances were observed in Li, Na, Be, for which accurate $g$ values and relaxation times were obtained and compared with existing theories. K gave a signal only at 4\ifmmode^\circ\else\textdegree\fi{}K and 300 Mc/sec, with too poor a signal-to-noise ratio to make accurate measurements. No resonances were observed in Mg, Al, Pd, W. The line shapes predicted by Dyson's theory for the resonance absorption in metals were checked experimentally for different diffusion times and relaxation times. A satisfactory agreement between the theory and experiment is obtained for both the normal and the anomalous skin effect region.
The need to improve the formation of the modern academic employment contract

Faculty policy and procedure manuals are an integral part of academic employment contracts. Yet their importance is underestimated by instructors and educational institutions alike. They are usually referred to in crisis situations only, when the relationship between an educator and a school has begun to deteriorate. It is at this point that faculty allege a violation of their rights and turn to written documentation to support their contention. Colleges and universities, who as the drafters of these documents are thoroughly familiar with their contents, are forced to respond by using the handbooks as shields against legal claims. An academic's failure to review faculty manuals at the outset of employment experience leaves himself uninformed as to his rights as an employee and vulnerable to attacks regarding his responsibilities as a professional.
Persistent current distribution on the superconducting shield of the cioffi magnet

Abstract The superconducting magnet attributed to Cioffi1 employs a shield of sheet superconductor. In this paper the shielding effect is considered in detail as due to the induced persistent current distribution on the shield. The current distribution on shields of appropriate geometries is evaluated from the electromagnetic boundary conditions. Examination of Cioffi's original shielding geometry reveals several spots of singularly high current density. Critical phenomena at these spots may account for irreversible breakdown of the shielding action. A class of novel magnet geometries is proposed where the current density on the shield is uniform. Magnets of these geometries should function reversibly up to the critical field of the shielding superconductor.
From the Classroom to the Courtroom: Intelligent Design and the Constitution

Although the Supreme Court of the United States has never developed a single clear test for determining what kinds of state action violate the Establishment Clause of the First Amendment, schools that attempt to teach or introduce intelligent design as a purportedly scientific alternative to evolution likely fall afoul of the First Amendment's commands. Under the Court's most relevant precedent, Edwards v. Aguillard, teaching intelligent design violates the Establishment Clause because, among other things, there is an enormous disconnect between the purpose of teaching intelligent design and its effect. Moreover, public school teachers do not possess any First Amendment right of academic freedom to disregard the clear instructions of a school principal or district not to teach or introduce intelligent design in their classrooms.
The relationship between calcium, MAP kinase, and DNA synthesis in the sea urchin egg at fertilization.

Fertilization releases the brake on the cell cycle and the egg completes meiosis and enters into S phase of the mitotic cell cycle. The MAP kinase pathway has been implicated in this process, but the precise role of MAP kinase in meiosis and the first mitotic cell cycle remains unknown and may differ according to species. Unlike the eggs of most animals, sea urchin eggs have completed meiosis prior to fertilization and are arrested at the pronuclear stage. Using both phosphorylation-state-specific antibodies and a MAP kinase activity assay, we observe that MAP kinase is phosphorylated and active in unfertilized sea urchin eggs and then dephosphorylated and inactivated by 15 min postinsemination. Further, Ca(2+) was both sufficient and necessary for this MAP kinase inactivation. Treatment of eggs with the Ca(2+) ionophore A23187 caused MAP kinase inactivation and triggered DNA synthesis. When the rise in intracellular Ca(2+) was inhibited by injection of a chelator, BAPTA or EGTA, the activity of MAP kinase remained high. Finally, inhibition of the MAP kinase signaling pathway by the specific MEK inhibitor PD98059 triggered DNA synthesis in unfertilized eggs. Thus, whenever MAP kinase activity is retained, DNA synthesis is inhibited while inactivation of MAP kinase correlates with initiation of DNA synthesis.
Control of reproduction in adult ewes and ewe lambs, and estimation of reproductive wastage in ewe lambs following treatment with progestagen impregnated sponges and PMSG

Abstract The progestagen impregnated sponge, used in conjunction with a dose of PMSG (Pregnant Mare's Serum Gonadotrophin), was evaluated as a practical method for the control of reproduction in adult ewes and ewe lambs. The method gave good results with adult ewes. The conception rate at the controlled oestrus was 59, 64 and 89% for ewes treated during April, July and October, respectively. Oestrus was effectively synchronized, during the breeding season, in Galway (G), 1 4 Finn 3 4 Galway ( 1 4 F), Finn × Galway (FG) and Finnish Landrace (FL) ewe lambs following hormone treatment. The lambing outcome, however, was very variable and depended to a large extent on the breed involved. The percentage of treated G, 1 4 F, FG and FL ewe lambs which actually lambed was 19, 45, 89 and 72, respectively. The causes of reproductive failure in hormone treated Galway ewe lambs were studied. In slaughter experiments, a high ovum fertilization rate (78%) was observed but only 39% of mated animals were pregnant at 26 days post coitum. The results of experiments involving reciprocal transfer of fertilized eggs between ewe lambs and adult ewes suggest that ova produced by Galway ewe lambs have an inherently low potential for continued development. It would appear that it is this, rather than any deleterious conditions in the reproductive tract, which is responsible for low conception rates observed in ewe lambs of this breed.
West Nile Virus Infections

Since its introduction to the United States in 1999, West Nile virus (WNV) has become endemic in North America and has emerged as the most common cause of epidemic meningoencephalitis in North America and the leading cause of arboviral encephalitis in the United States. West Nile virus is maintained in nature by cycling between mosquito vectors and bird hosts; humans are incidental hosts. Transmission to humans occurs predominantly after a bite from an infected mosquito but has also occurred via transfusion of blood products, via organ transplantation from infected donors, transplacentally, and percutaneously through occupational exposure. Approximately one of 150 patients develops central nervous system manifestations, including meningitis, encephalitis, and acute flaccid paralysis/poliomyelitis. Risk factors for neuroinvasive disease include older age and immunosuppression. Imaging findings are nonspecific, and cerebrospinal fluid findings include pleocytosis, elevated protein, and normal to decreased glucose. The diagnosis is made in most patients on serological examination. Reverse transcription polymerase chain reaction tests are useful to screen blood products and for surveillance of birds and mosquitoes. The pathological findings are typical of a viral meningoencephalitis and include microglial nodules, perivascular chronic inflammation, and variable neuronal loss with necrosis or neuronophagia. Treatment is largely supportive, and control of the mosquito vectors may reduce the incidence of human infections.