cssi/SciSciGPT-SciSciNet huggingface dataset:
Why Write an Exposé of Rigoberta Menchú

In the introduction, where the most casual reader could not miss it, David Stoll says of Rigoberta Menchu's (Burgos-Debray, 1984) book, "There is no doubt about [her] most important points: that a dictatorship massacred thousands of indigenous peasants, that the victims included half of Rigoberta's immediate family, that she fled to Mexico to save her life, and that she joined a revolutionary movement to liberate her country" (1998: vii). She is only misleading or wrong about the "situation of her family and village life before the war" (1998: vii) and about having witnessed some of the incidents she describes. He adds, "Most of the pressure that forced the army and the government to negotiate [with the guerrillas, leading to a peace accord at the end of 1996] came from abroad, and it was generated by human rights imagery" (1998: 8) in which Rigoberta's book played an extremely important role (1998: 11). After these concessions, he asks, "If Rigoberta is fundamentally right about what the army did, if her story expresses a larger truth about the violence, why dissect a personal account that is inevitably selective?" (1998: viv). He answers his question with the following four points: First, the catastrophes that befell Rigoberta's family, her village, and other indigenous villages in western Guatemala were brought on by the revolutionary guerrillas as much as by the army. In the particular case of Rigoberta's village, Rigoberta's father, Vicente, appears to have invited the guerrillas there-or at least to have received them warmly.' Hence the targeting of his family by the army was quite natural. In the case of Vicente Menchu's death in a conflagration at the Spanish embassy, it may be that the victims (who were protesting army murders of their relatives) immolated themselves.2 More generally, guerrillas pursue "a high-risk strategy that usually ends in defeat and disillusion, after sacrificing peasants to romantic images of
Detection of antisperm-antibodies in patients with primary testicular cancer.

Summary Serum antisperm-antibodies have been noted to develop as a result of various types of testicular pathology and injury. Their presence sometimes correlates with impaired fertility. We examined 52 patients with non-seminomatous low-stage testicular cancer for the presence of serum antisperm-antibodies to determine whether or not auto-immunity is a factor in the depressed fertility known to exist in these patients. Twenty-one per cent were discovered to have serum antisperm-antibodies using an immunofluorescent technique.
Preradiation chemotherapy for newly diagnosed childhood brain tumors. A modified phase II trial

A poor-risk population of children with primary malignant central nervous system (CNS) tumors, other than gliomas, can be identified by their young age, by the presence of disease dissemination at diagnosis, and possibly by subtotal resection of the primary tumor. These children require at least neuraxis radiation therapy and possibly chemotherapy for disease control. Unfortunately, once neuraxis radiation is administered, tolerance of subsequent chemotherapy is limited. The authors have explored a multimodal treatment approach in 14 poor-risk patients initially consisting of a modified Phase II chemotherapy trial followed by neuraxis radiation. The diagnoses were medulloblastoma (5), pineoblastoma (3), cerebral primitive neuroectodermal tumor (3), germinoma (2), and choroid plexus carcinoma (1). Eleven patients had disseminated CNS disease, and two had bone marrow involvement at diagnosis. Nine patients received 2 courses of intravenous cyclophosphamide (80 mg/kg) alone over 8 weeks, and five others received three daily doses of intrathecal Ara-C (50 mg/m2) and oral hydroxyurea (40 mg/kg) with each course of cyclophosphamide. There were four complete responses (two dysgerminomas, one pineoblastoma, and one primitive neuroectodermal tumor), one partial response (medulloblastoma), and three mixed responses (two medulloblastomas, one pineoblastoma) to chemotherapy alone, for a response rate of 57%. Twelve patients subsequently tolerated the planned dose of neuraxis radiation. The median survival of all patients was 11 months, and seven of eight deaths were related to recurrent disease. The hematologic toxicity was appreciable, and one death resulted from gram-negative septicemia. Through the use of this type of Phase II trial, valuable information can be obtained on the response rates to specific chemotherapy agents administered prior to radiation. Although cyclophosphamide alone was an active agent in this context, these treatment regimens did not have an important affect on survival.
Clinical prognostic factors in surgically treated stage IIIA-N2 non-small cell lung cancer: analysis of the literature

There remains controversy on the prognostic value of several common clinical factors in NSCLC patients with resected N2-disease. The aim of this paper is to give a comprehensive overview of the available data on this issue. Literature data on surgically treated N2-NSCLC-patients from 1980-1995, peer reviewed and listed in Index Medicus, were analysed. Reported and calculated or estimated survival data were indexed. Eighteen series were selected: in 12 of them, direct comparisons between survival curves of subgroups are reported; six contained sufficient data to make comparisons of survivors at 5 years; three of them also made a multivariate Cox model. The analysis of prognostic factors in a single study was often hampered by the limited number of patients. Nonetheless, it could be concluded that patients with a clinical N0- or N1-status (so-called unforeseen N2) do better. There was no clear difference between patients undergoing lobectomy or pneumonectomy. There was strong evidence that N2-patients with a less advanced primary tumour (T-stage) have a better prognosis, and this is the case for all operable T-stages (T1 versus T2, T1 versus T3, T2 versus T3). Squamous cell type was a favourable prognostic factor, as was the presence of only one metastatic mediastinal lymph node station or absence of metastases to the subcarinal nodes. There was some evidence that the presence of extracapsular spread in metastatic MLN is an unfavourable finding. Stratification for these prognostic factors could help in the planning of future trials on combined modality treatment in N2-NSCLC.
Do warning displays predict striking behavior in a viperid snake, the cottonmouth (Agkistrodon piscivorus)?

Warning displays are defined as signals designed to intimidate predators or indicate a proclivity to fight. However, support for the idea that warning behaviors signal an intent to fight is largely based on anecdotes and isolated observations, and a complete understanding of antipredator behavior will only be achieved if specific hypotheses are experimentally tested. Herein, we tested in a North American viperid snake, the cottonmouth (Agkistrodon piscivorus (Lacepede, 1789)), the hypothesis that warning displays serve as a reliable signal to potential predators that a snake will strike. The cottonmouth exhibits two stereotypical warning displays during predator confrontation, i.e., mouth gaping and tail vibrations, making it an ideal study organism to experimentally test the relationship between warning displays and defensive striking. To test this idea, we recorded the sequence of defensive behavior — gaping, tail vibrating, and striking — of cottonmouths towards a standardized predatory stimulus in the...
Tetrazole‐based, Anhydrous Proton Exchange Membranes for Fuel Cells

A tetrazole-based polymer electrolyte membrane showed high conductivity at 20-120°C under dry conditions, offering the potential to dramatically simplify fuel cells for many applications over a wide temperature range without the need for cumbersome humidification and pressurization.
Segmented K-Space Cine Breath-Hold Cardiovascular MR Imaging: Part 1. Principles and Technique

Several well-established MR techniques are routinely used for evaluation of the heart and great vessels. Tl-weighted spin-echo images gated to the cardiac cycle provide black-blood images of the heart and vessels. Spin-echo images provide good anatomic detail, but imaging times are relatively long (approximately 5–7 min, depending on the heart rate). In addition, the images are static: only a single cardiac phase is typically acquired during this interval to avoid excessively long imaging times. Cine image acquisition often provides essential information about the cardiac chambers and flowing blood—information complementatary to the anatomic information provided on T1-weighted spin-echo images. A cine sequence of the heart consists of multiple static images that are rapidly displayed in a continuous loop. Most often, gradient-recalled echo pulse sequences are used to provide bright-blood cine images of the heart and vessels. Standard gradient-recalled echo sequences require 3–5 min to produce a cine acquisition of one to four image slices using either retrospective on prospective cardiac gating [1]. Segmented K-space cardiac sequences were described by Atkinson and Edelman [2] and allow 12–18 phases of the cardiac cycle (referred to later in this article as movie frames of a cine sequence) to be acquired in a single breath-hold using prospective cardiac gating. Segmented K-space acquisitions have been used extensively in research protocols—for example, in conjunction with MR tagging techniques [3]—although they have been less frequently used in clinical studies [4]. Commercial implementations of the pulse sequence are becoming more widely available. This essay reviews segmented K-space acquisition and illustrates different modes of application of this method for rapidly obtaining cardiac cine sequences.
Radar networking in Collaborative Adaptive Sensing of Atmosphere: State of the art and research challenges

Collaborative Adaptive Sensing of the Atmosphere (CASA), in which a network of small weather radars collaborates in real time, has emerged as the preferred alternative for accurately detecting and tracking hazardous weather phenomena such as tornados. We address data transport and multi-sensor data fusion solutions proposed in context of CASA, focusing on their ability to support streaming and data pull modes of radar data access. How CASA can leverage emerging technologies, such as Named Data Networking (NDN), virtualization, and cloud computing to meet the performance, quality of service, and resource utilization requirements in a scalable manner are addressed. Open issues and research challenges for realizing the true potential of large-scale CASA networks are considered.
TMG catalyzed cyclopropanation of cyclopentenone. Illustration by a simple synthesis of bicyclo[3.1.0]hexane-2-one derivatives

The catalytic preparation of bicyclo[3.1.0]hexane-2-one-6-carboxylic acid ethyl ester 1 is described by cyclopropanation of cyclopentenone using 1,1,3,3-tetramethylguanidine (TMG) as a catalyst in high yield and high diastereoselectivity. This process has been applied to an efficient synthesis of the important intermediate, β-hydroxyl cyclopentanone 2.
Excimer laser-induced perturbation spectroscopy: an approach to biosensing

The development of new smart sensing methodologies that provide improved sensitivity and/or specificity for rapid and accurate biosensing is highly desirable for in situ and in vivo cancer screening and detection of biological pathogens. However, to date clinical applications of cancer sensing schemes have been for the most part limited by the large patient-to- patient variations in optical response (e.g. fluorescence or Raman signals), as well as by the large variation in background signal levels. A novel biosensing scheme is presented that is based on our recent research showing that the biological matrix may be altered by low intensity (i.e., below the ablation threshold) ultraviolet radiation (primarily 193 to 213 nm) such that the intrinsic fluorescence response is perturbed. Specifically, a sequential combination of optical probing (e.g. fluorescence emission), UV photochemical perturbation, and repeat optical probing is explored as a new spectral dimension based on difference spectroscopy. It is expected that the response is strongly coupled to the local biomolecular matrix. Because the same targeted material is optically probed both before and after perturbation with the UV light source, the resulting differential response may help mitigate variations in the absolute optical response. Preliminary data is presented using imaging mode and spectroscopy modes for several organic matrices as a proof of concept.
A Fault-Tolerant Network Protocol for Real-Time Communications

We present a network access protocol suitable for use in real-time applications. It features high throughput, bounded message delay, tolerance of failed nodes, automatic resynchronization when failed nodes are revived, deadlock avoidance, and high reliability. The protocol is ideally suited for a bus topology and fiber-optic media. Measured performance data is provided from an implementation of 45 nodes operating on a 10-Mbps fiber-optic bus.
Resonant multiwave-mixing spectra of gas-phase sodium: Nonperturbative calculations.

We perform nonperturbative calculations of resonant multiwave mixing of two high-intensity laser beams of different frequencies both for a general three-level system and for the 3 {sup 2}{ital S}{sub 1/2}--3 {sup 2}{ital P}{sub 1/2} electronic resonance of the sodium atom. Our calculations proceed by direct numerical integration of the density-matrix equations and subsequent Fourier analysis of the calculated time-dependent density-matrix elements. We examine the case where two nearly degenerate input beams are each detuned many collisional linewidths from electronic resonance, and the frequency difference between the input beams is tuned through a ground-state resonance. Unlike previous high-intensity analyses, each input beam can be resonant with numerous transitions simultaneously; for a three-level system, we refer to this as an M-type'' system, in analogy with {Lambda}- and V-type systems. Calculated four-, six-, and eight-wave-mixing spectra exhibit subharmonic resonances of the type observed experimentally by Trebino and Rahn (Opt. Lett. 12, 912 (1987)). The three-level system is studied to gain insight into the physics of these subharmonic resonances. For more quantitative comparison with experiment, we use a model that includes the 16 Zeeman and hyperfine states in the 3 {sup 2}{ital S}{sub 1/2} and the 3 {sup 2}{ital P}{sub 1/2} levels, and accountsmore » for arbitrary linear polarization of the input laser radiation. The relative intensities of the resonance features in the calculated multiwave-mixing spectra show good agreement with experiment. These resonance features broaden and shift as laser intensity increases, as predicted for four-wave-mixing processes in previous, less general high-intensity analyses. Both theory and experiment also show additional resonant features in the eight-wave-mixing spectra that appear at very high intensity.« less
Catalytic gasification of coal for the production of fuel cell feedstock

Fuel cell technology is advancing rapidly. This creates a critical need for economical hydrogen production. Proper levels of H2 and CH2 for fuel cell feed could result from catalytic gasification of low-rank coal. Bench-scale steam gasification catalyst testing was carried out on Illinois No. 6 bituminous and Center North Dakota lignite coals with catalysts containing Fe, Ni, Ca, or K and some combinations of these. All of the catalysts tested showed a modest catalytic effect with both coals, ranging from negligible to nearly 30-fold increase in reaction rate. Nickel and iron enhanced the rate slightly, while increasing methane concentration.
Solubilized extracellular matrix from brain and urinary bladder elicits distinct functional and phenotypic responses in macrophages

Extracellular matrix (ECM) derived from a variety of source tissues has been successfully used to facilitate tissue reconstruction. The recent development of solubilized forms of ECM advances the therapeutic potential of these biomaterials. Isolated, soluble components of ECM and matricryptic peptides have been shown to bias macrophages toward a regulatory and constructive (M2-like) phenotype. However, the majority of studies described thus far have utilized anatomically and morphologically similar gastrointestinal derived ECMs (small intestine, esophagus, urinary bladder, etc.) and a small subset of macrophage markers (CD206, CD86, CCR7) to describe them. The present study evaluated the effect of solubilized ECM derived from molecularly diverse source tissues (brain and urinary bladder) upon primary macrophage phenotype and function. Results showed that solubilized urinary bladder ECM (U-ECM) up-regulated macrophage PGE2 secretion and suppressed traditional pro-inflammatory factor secretion, consistent with an M2-like phenotype. The hyaluronic acid (HA) component in solubilized U-ECM played an important role in mediating this response. Brain ECM (B-ECM) elicited a pro-inflammatory (M1-like) macrophage response and contained almost no HA. These findings suggest that the molecular composition of the source tissue ECM plays an important role in influencing macrophage function and phenotype.
Applications of hyperspectral remote sensing and GIS for assessing forest health and air pollution

The objective of this project is the assessment of air pollution impacts on conifer health in the Sierra Nevada of California, USA and the Pyrenees of Catalonia, Spain using remote sensing indices of forest health in conjunction with GIS analyses of the variability various stressors across natural landscape gradients. The Ozone Injury Index (OII) field metric applied to P. ponderosa and P. jeffreyi in the USA and adapted to P. uncinata in Spain included chlorotic mottling, needle retention, needle length, and crown depth. Species-level classifications of AVIRIS and CASI hyperspectral imagery were all near 80% overall accuracy for the target bioindicator species. Combining remote sensing indices with GIS variables related to microsite ozone uptake variability produced improved regressions for Catalonia (R2=0.68, p&#60;0.0001) and California (R2=0.56, p&#60;0.0001). Multiple regression models for the ozone injury visual component (VI) alone performed much better than the full OII in Catalonia combining the remote sensing index PRI and a three year average of ambient ozone (R2=0.56, p&#60;0.0001) and better still when including GIS variables (R2=0.77, p&#60;0.0001).
On t∞ quasi-similarity of linear systems

Conti defined t∞ similarity of systems (1)x′=tA(t)xand (2)y′=B(t)y, and showed that it is an equivalence relation which preserves uniform and strict stability. Here the definition is weakened by imposing less stringent integrability conditions, some in terms of perhaps conditionally convergent improper integrals, on the matrix function relating A and B. The extended relation, t∞ quasi-similarity, is not symmetric or transitive; however, it is shown that if (2) is t∞ quasi-similar to (1)and (1)is uniformly, uniformly asymptotically, or strictly stable, then so is (2).Results are also given concerning linear asymptotic equilibrium of (2)in the case where (1)is stricly stable or has linear asymptotic equilibrium.
The decomposition of tungsten-chromium solid solution

Abstract The mechanism of solid solution decomposition within the chemical spinodal boundary was investigated for the tungsten-chromium system. Two alloys were solution treated, quenched, and aged at various temperatures inside the chemical spinodal boundary. It was concluded from X-ray and metallographie evidence that tungsten-chromium alloys do not decompose by a spinodal mechanism. The decomposition process was found to be one of nucleation and growth. This observation is in agreement with Cahn's (4) theory of the effect of strain energy on the occurrence of spinodal decomposition.
Neurocognitive changes after carotid revascularization: a review of the current literature.

Abstract Objective The objective of this study was to review the current literature evaluating the effect of carotid revascularization on neurocognitive function. Methods A PubMed search was performed using the following keywords: carotid surgery, carotid stenosis, cognition, and cognition disorders. Bibliographies were cross referenced and related-articles searches were performed once an article of interest had been identified. Results Twenty-two studies have been identified from the literature since 1998. Seventeen articles evaluated carotid endarterectomy (CEA), four evaluated carotid stenting, and one compared CEA to stenting. Eight studies found improvements in mood and/or cognition after revascularization, 11 studies showed mixed results, and 3 studies found declines. Conclusions There is no consensus within the current literature as to the effect of carotid revascularization on neurocognitive function. Further research—with attention to laterality of neurocognitive effects, patients' symptomatology at the time of presentation, the role of perioperative embolization, and trial design including adequate control groups and comparison between open surgery and stenting factors—is necessary in order to clarify the effects of carotid revascularization on cognition.
Should a Good Healthcare Professional Be (at Least a Little) Callous

The term “callous” has not, to this point, been studied empirically or considered philosophically in the context of healthcare professionalism. It should be, however, because its uses seem peculiar. Sometimes “callous” is used to suggest that becoming callous confers a benefit of some protection against emotional distress, which might be considered expedient in the healthcare work environment. But, “callous” also refers to a person's unappealing demeanor of hardened insensitivity. The tension between these different moral connotations of “callous” prompts several empirical, psychological, and moral questions; I introduce and entertain a few here. I also suggest a distinction between callousness and inurement and argue for why this distinction is important to appreciate and uphold in health professions education.
Commentary on ‘Optimization of experimental parameters for the EPR detection of the cellulosic radical in irradiated foodstuffs’

Summary After many interlaboratory trials, several EPR methods for the detection of irradiated foods are being prepared as standard protocols. The works of Goodman et al. (1994) and Raffi et al. (1992) present conflicting general recommendations for optimum parameter sets in the EPR protocols. Here we demonstrate the shortcomings of recommending general parameter sets for the varying types of food samples and the different spectrometer configurations employed to examine them.
Alignment layer relaxation—a technique for assessing thermal transitions in polymer films

Abstract We introduce a method for assessing the glass transition temperature (Tg) of thin polymer films. The technique may be applied to any polymer film that can effect liquid crystal alignment, and is demonstrated here for a commercial polyamide-imide. The method leverages the ability of the polymer film to align nematic liquid crystals on its surface, when that surface has been prepared by mechanical brushing. Relaxation of the alignment layer, brought about by thermal cycling through Tg, is seen to affect liquid crystal alignment, and thus serve as a Tg indicator. The technique reveals a three-order-of-magnitude change in the measured property. The method allows the assessment of that portion of the film responsible for aligning liquid crystals, and provides an indication of the efficacy of alignment. Our results imply that the relaxation of the surface in Probimide 32 occurs over a range of temperatures, and relaxation is not complete until the film is heated to a temperature above the glass transition of the bulk polymer.
Tricuspid valve repair for biopsy-induced regurgitation after cardiac transplantation

Tricuspid regurgitation is a recognized complication of cardiac transplantation. Damage to the tricuspid valve and subvalvar apparatus has been suggested as a possible cause. We have repaired the tricuspid valves of 2 patients in whom severely symptomatic tricuspid regurgitation developed after transplantation. Gore-Tex sutures were used to replace ruptured chordae anchoring the septal and posterior leaflets. The repair was supported with a Carpentier-Edwards ring. The repairs remain durable at 2 year and 3 years. Both patients demonstrated a similar lesion that we believe to be characteristic of endomyocardial biopsy-induced tricuspid regurgitation.
Molecular Basis for Subtype-specific Desensitization of Inhibitory Adenosine Receptors ANALYSIS OF A CHIMERIC A1-A3 ADENOSINE RECEPTOR

Abstract The differing effects of short-term agonist exposure on the two inhibitory adenosine receptor (AR) subtypes have been examined using Chinese hamster ovary cells stably expressing the hemagglutinin epitope-tagged human A1AR and rat A3AR. Under conditions in which exposure of transfected cells to 5 μM (−)-(R)-N6-(phenylisopropyl)adenosine resulted in the functional desensitization and phosphorylation of the A3AR, neither property was exhibited by the A1AR. However, a stably expressed chimeric A1-A3AR, termed A1CT3AR, in which the C-terminal domain of the A1AR distal to its predicted palmitoylation site was replaced by the corresponding region of the A3AR, was able to undergo functional desensitization and agonist-stimulated phosphorylation in a manner similar to that exhibited by the A3AR. Moreover, purified G-protein-coupled receptor kinases 2, 3, and 5 were each capable of enhancing the agonist-dependent phosphorylation of the A3AR and A1CT3AR in vitro. Taken together, these data demonstrate that the C-terminal domain of the A3AR distal to its predicted palmitoylation site is responsible for this receptor's ability to undergo a rapid agonist-dependent desensitization and are consistent with a model in which phosphorylation of the A3AR within this domain by one or more G-protein-coupled receptor kinases initiates the desensitization process.
Leukemic blasts with the paroxysmal nocturnal hemoglobinuria phenotype in children with acute lymphoblastic leukemia.

It has been proposed that genomic instability is essential to account for the multiplicity of mutations often seen in malignancies. Using the X-linked PIG-A gene as a sentinel gene for spontaneous inactivating somatic mutations, we previously showed that healthy individuals harbor granulocytes with the PIG-A mutant (paroxysmal nocturnal hemoglobinuria) phenotype at a median frequency ( f ) of ∼12 × 10 −6 . Herein, we used a similar approach to determine f in blast cells derived from 19 individuals with acute lymphoblastic leukemia (ALL) and in immortalized Epstein-Barr virus–transformed B-cell cultures (human B-lymphoblastoid cell lines) from 19 healthy donors. The B-lymphoblastoid cell lines exhibited a unimodal distribution, with a median f value of 11 × 10 −6 . In contrast, analysis of the f values for the ALL samples revealed at least two distinct populations: one population, representing approximately half of the samples ( n = 10), had a median f value of 13 × 10 −6 , and the remaining samples ( n = 9) had a median f value of 566 × 10 −6 . We conclude that in ALL, there are two distinct phenotypes with respect to hypermutability, which we hypothesize will correlate with the number of pathogenic mutations required to produce the leukemia.
Statistical timing optimization of combinational logic circuits

High performance circuit design is becoming increasingly important in VLSI design. The most important problem faced in the design of these circuits is to meet a certain performance level. In the past few years CAD algorithms and tools have been well developed that improve the performance of logic circuits in the sense that the worst case delay is minimized. However, manufacturers recognize that worst case delay models are typically pessimistic and the manufactured ICs will have a range of performances reflecting the manufacturing variations. Thus, the real problem that needs to be solved in the performance optimization of these circuits is to maximize the percentage of fabricated circuits that will achieve a certain performance level, as opposed to minimizing the worst case delay which has been the focus thus far. We develop methods to improve the statistical timing behavior of a combinational logic circuit, given probability distributions for the gate and wire delays. This work uses a statistical timing analysis technique developed earlier to drive timing optimization in the right direction to achieve a prescribed goal with the least area overhead. >
Broadcast Scheduling With Latency and Redundancy Analysis for Cognitive Radio Networks

Cognitive radio networks (CRNs) introduce a new communication paradigm that enables unlicensed users to opportunistically access spectrum bands assigned to licensed users. Interestingly, the broadcast problem, which is one of the most fundamental operations in CRNs, has not been well studied. Existing works for the broadcast issue in CRNs are heuristic solutions either without a performance guarantee or with performance far from the optimal solution. In this paper, we study the minimum-latency broadcast scheduling (MLBS) issue for CRNs. Our contributions are threefold. First, we propose a mixed broadcast scheduling (MBS) algorithm under the unit disk graph (UDG) model, denoted by MBS-UDG. MBS-UDG finishes a broadcast task by employing mixed unicast and broadcast communication modes in two phases. We show that the latency performance of MBS-UDG is $O(\hbar+\Delta_{T})$ when $\Delta_{T}\leq \hbox{1}/p$ or $O(\hbar+\log_{1-p}(\hbox{1}/p\Delta_{T}))$ when $\Delta_{T}>\hbox{1}/p$ , where $\hbar$ and $\Delta_{T}$ are the height and the maximum number of leaf nodes connected by a second user (SU)of the broadcasting tree, respectively, and $p$ is the spectrum opportunity for a secondary communication. Furthermore, the redundancy performance of MBS-UDG is analyzed. Second, we extend MBS-UDG to a more general MBS algorithm under the protocol interference model and analyze its latency and redundancy performance. Finally, simulations are conducted to validate MBS, which indicate that MBS significantly improves existing algorithms with respect to both latency and redundancy.
The internet, teenagers, and sexual health information: a cautionary tale

Although most Israeli teenagers have access to the web and many have used the internet to obtain health information, they do not have access to accurate and complete information about contraceptives on Hebrew language websites. Indeed other evidence suggests that teens do not use the web frequently for health information, they are wary of the information obtained from internet sites, and the search engines that they use may not lead them to the most helpful resources. While the internet has the capacity to provide teenagers with information which can assist them in preventing unintended pregnancy and sexually transmitted infections, interventions that address these challenges need to be developed and rigorously tested.
Factors Influencing the Occurrence of High Numbers of Iodine-Resistant Bacteria in Iodinated Swimming Pools

It has been shown that, although iodinated swimming-pool waters are usually free from coliform bacteria and enterococci, the total counts frequently become relatively high. Pseudomonas alcaligenes and Alcaligenes faecalis have been shown to account for most of these high counts. It was of interest, therefore, to compare the microbial flora of four alternately chlorinated and iodinated swimming pools. By means of the membrane filter method and suitable selective media, examinations were made for total viable counts, coliform bacteria, enterococci, staphylococci, Streptococcus salivarius, and P. aeruginosa. Colonies also were picked from membrane filters incubated on standard plate count agar and identified. The results showed that, although viable counts were significantly higher during the iodinated periods, the specific types of bacteria determined were either fewer than or the same as in chlorinated periods. During chlorination, the predominant microbial flora consisted of staphylococci and members of the genus Bacillus. During iodination, however, the P. alcaligenes-A. faecalis group accounted for 92 to 99% of the microbial flora. The accumulation of high numbers of these bacteria was shown to be due to their iodine resistance and their ability to grow rapidly in pool water in the absence of free iodine.
A Computational Study of the Flow Through a Vitreous Cutter

Vitrectomy is an ophthalmic microsurgical procedure that removes part or all of the vitreous humor from the eye. The procedure uses a vitreous cutter consisting of a narrow shaft with a small orifice at the end through which the humor is aspirated by an applied suction. An internal guillotine oscillates back and forth across the orifice to alter the local shear response of the humor. In this work, a computational study of the flow in a vitreous cutter is conducted in order to gain better understanding of the vitreous behavior and provide guidelines for a new vitreous cutter design. The flow of a Newtonian surrogate of vitreous in a two-dimensional analog geometry is investigated using a finite difference-based immersed boundary method with an algebraically formulated fractional-step method. A series of numerical experiments is performed to evaluate the impact of cutting rate, aspiration pressure, and opening/closing transition on the vitreous cutter flow rate and transorifice pressure variation during vitrectomy. The mean flow rate is observed to increase approximately linearly with aspiration pressure and also increase nearly linearly with duty cycle. A study of time-varying flow rate, velocity field, and vorticity illuminates the flow behavior during each phase of the cutting cycle and shows that the opening/closing transition plays a key role in improving the vitreous cutter's efficacy and minimizing the potential damage to surrounding tissue. The numerical results show similar trend in flow rate as previous in vitro experiments using water and balanced saline solution and also demonstrate that high duty cycle and slow opening/closing phases lead to high flow rate and minor disturbance to the eye during vitrectomy, which are the design requirements of an ideal vitreous cutter.
Intravenous immunoglobulin, HLA allele typing and HLAMatchmaker facilitate successful transplantation in highly sensitized pediatric renal allograft recipients

The use of intravenous immunoglobulin (IVIG) in sensiti- zed transplant candidates has resulted in reduced HLA antibody levels and shorter transplant wait times. In addition, the HLA- Matchmaker program has been used to identify acceptable mis- matches to permit transplantation in highly sensitized patients. We used IVIG desensitization in conjunction with high resolution HLA allele typing and HLAMatchmaker grading of donor offers to facilitate successful transplantation in two highly sensitized children who were awaiting second renal transplants. Both patients lost their initial transplant in <10 days to accelerated acute rejection, and were on dialysis for an average of 50 months with high panel reactive antibody (PRA) levels. They were started on monthly IVIG infusions (2 g/kg/dose). Within one wk following their third and fifth IVIG doses, both patients received a crossmatch compatible, deceased donor renal transplant selected by HLAMatchmaker as a suitable donor offer. Both patients remain rejection free with excellent renal function 19 and 15 months post-transplant, respectively. In conclu- sion, combining IVIG therapy and donor selection by HLA humoral epitope matching permitted successful transplantation of two highly sensitized children. Further studies in larger numbers of patients with longer follow-up are needed to determine the individual role played by, and relative importance of each component of this combined strategy.
Atlantooccipital disassociation: a case report.

Case Report Our air medical program received a request to respond to an industrial accident at a rock quarry 40 miles away from the base. A 37-year-old man had caught his left arm in a rock crusher, partially amputating it, and then he fell approximately 15 feet. The EMS crew found him lying on the ground supine and unresponsive. He had been fully immobilized on a long spine board and had a large bulky dressing on his left upper extremity with no active bleeding. On examination, his Glascow coma scale was 4, and he had some random eye movement. His extremities showed no spontaneous movement. He was breathing adequately with a heart rate of 130 and a palpated blood pressure of 70 mmHg. The crew decided to intubate him because of his mental status. A rapid sequence induction was performed with lidocaine, etomidate, and anectine; the patient was intubated on the first attempt. Further physical examination confirmed an amputation of his left upper ext remity at the elbow and revealed abrasions and subcutaneous emphysema on the left side of his chest with slightly diminished breath sounds on the left side. His amputated extremity had been placed in a bag and then into an ice cooler. En route to the trauma center, the crew placed a second large bore intravenous line, and one unit of packed red blood cells was started for sustained tachycardia and hypotension. The transport time was 19 minutes. On arrival at our ED, the patient initially was evaluated by the trauma service. His neurologic status was unchanged, his blood pressure was 109/41, and his heart rate was 112/rain. Portable chest x-ray film revealed a small hemopneumothorax on the left side, and a chest tube was inserted. A cross table C-spine and AP pelvis films also were taken. His humerus and shoulder films showed an amputation at the left elbow and widening of the AC joint. The reimplantation team was alerted, and the patient was taken to the CT scanner. CT scans of the patient's head and abdomen were negative, and he was admitted to the trauma ICU. Review of his cervical spine films revealed an AOD with a large hematoma posterior to the cervical spine and prever tebra l soft t issue swelling. Given the dismal prognosis of his injury, life support was withdrawn after consultation with his family. He died shortly thereafter.
Hepatitis B Virus and Hepatitis B Surface Antigen in Human Albumin Products

A collection of 1,985 lots of normal serum albumin (NSA) and 1,361 lots of plasma protein fraction (PPF) prepared between 1958 and 1974 were tested for the presence of hepatitis B surface antigen (HBsAg). Twenty-one per cent of NSA lots and 71 per cent of PPF lots were HBsAg-positive by radioimmunoassay. There was considerable variation in frequency of HBsAg-positive lots among the 17 different manufacturers of NSA and the six manufacturers of PPF. In general, those lots prepared from volunteer donor plasma and placental material demonstrated lower rates of HBsAg-positivity than those prepared from commercial donor plasma. A striking decrease in the prevalence of HBsAg-positive lots of both NSA and PPF occurred during the period 1971 to 1973, coincident with the onset of routine screening of all plasma for HBsAg. Although NSA and PPF can be HBsAg-positive, they probably do not transmit type B hepatitis. Serologic tests for HBsAg and antibody to HBsAg revealed that albumin products prepared from infectious, icterogenic plasma were infectious prior to pasteurization, but that they no longer transmitted type B hepatitis after heat treatment at 60 C for ten hours.
Plasma bile acid concentrations in patients with human immunodeficiency virus infection receiving protease inhibitor therapy: possible implications for hepatotoxicity.

Liver dysfunction and disease can result in elevations in plasma bile acid concentrations, as well as perturbations in the relative contribution of each bile acid to the total bile acid pool.1-8 Total bile acid concentrations and the cholic acid:chenodeoxycholic acid ratio are elevated in primary sclerosing cholangitis3-6 and cholestasis.5 Hepatotoxicity implicated from occupational and drug exposure has also been associated with elevations in total bile acid concentrations.9-13 Recently, we published the results of a clinical investigation conducted in 11 human immunodeficiency virus (HIV)–infected patients on the pharmacokinetics, safety, and efficacy of an antiretroviral regimen that included three protease inhibitors: amprenavir, ritonavir, and saquinavir.14 During that study, drug-induced hepatotoxicity was diagnosed in one of the 11 patients. In this current study, we used blood samples obtained from that study to determine whether the average plasma concentrations of individual bile acids of HIV-infected patients differ compared with a population of non–HIV-infected individuals, whether protease inhibitor therapy influences bile acid concentrations during a dosing interval, and whether elevations in total or individual plasma bile acid concentrations might be an early signal of drug-induced hepatotoxicity.
Reconstruction of the chin-lower cheek complex with a platysma myocutaneous flap.

About 100 years ago, the Austrian surgeon Gersunyl used a flap of neck skin with the underlying platysma muscle to close a through and through defect of the cheek. To our knowledge this is the earliest recorded use of the superiorly-based platysma myocutaneous flap. Thirty years later, Cole2y3 further demonstrated the usefulness of the flap to correct intraoral defects and shortly thereafter Kanaver used the flap to fill a soft tissue defect of the chin region and to treat syphilitic osteomyelitis of the mandible. In the 195Os, several head and neck cancer surgeons described cervical skin flaps to reconstruct defects of the chin and lower cheek.5p6 DesPrez and Kiehn7 modified the apron flap (cervical skin flap) by de-epithelializing its proximal portion and transposing the distal “paddle” to reconstruct the oral lining: in essence, they raised a large, superiorly-based platysma myocutaneous flap. Martin8 and Ellis9 suggested that the muscle be included in neck skin flaps elevated during radical neck dissection. The blood supply of the neck and skin was then studied in superiorly-based platysma myocutaneous “skin-paddle” flaps used to reconstruct intraoral defectslo and in systematic dissections and injection studies.” Cannon et al.12 reported that the one-stage platysma flap reconstruction was highly useful in 22 patients with intraoral
Growth factor signaling in lung morphogenetic centers: automaticity, stereotypy and symmetry.

Lung morphogenesis is stereotypic, both for lobation and for the first several generations of airways, implying mechanistic control by a well conserved, genetically hardwired developmental program. This program is not only directed by transcriptional factors and peptide growth factor signaling, but also co-opts and is modulated by physical forces. Peptide growth factors signal within repeating epithelial-mesenchymal temporospatial patterns that constitute morphogenetic centers, automatically directing millions of repetitive events during both stereotypic branching and nonstereotypic branching as well as alveolar surface expansion phases of lung development. Transduction of peptide growth factor signaling within these centers is finely regulated at multiple levels. These may include ligand expression, proteolytic activation of latent ligand, ligand bioavailability, ligand binding proteins and receptor affinity and presentation, receptor complex assembly and kinase activation, phosphorylation and activation of adapter and messenger protein complexes as well as downstream events and cross-talk both inside and outside the nucleus. Herein we review the critical Sonic Hedgehog, Fibroblast Growth Factor, Bone Morphogenetic Protein, Vascular Endothelial Growth Factor and Transforming Growth Factorβ signaling pathways and propose how they may be functionally coordinated within compound, highly regulated morphogenetic gradients that drive first stereotypic and then non-stereotypic, automatically repetitive, symmetrical as well as asymmetrical branching events in the lung.
Attempts to produce spike-and-wave complexes in the electrocorticogram of the rat.

SUMMARY The effects of several procedures for inducing spike-and-wave complexes in other experimental animals have been examined in the rat. Systemic convulsants, pentylenetetrazol, methionine sulfoximine and fluoroacetate, topical picrotoxin, and bilateral implants of cobalt produced the appearance of polyspike discharges in the ECoG. Topical application of conjugated estrogens to both frontal cortices elicited single spike-and-slow-wave complexes which did not repeat at 3 to 5 cps. These results suggest that the rat is not a suitable species for a detailed study of spike-and-wave production. RESUME On a pris en consideration chez les rats, les effets des differentes methodes deja utilisees chez d'autres animaux pour produire des complexes de pointe-onde. Les moyens suscep-tibles de provoquer des decharges de poly-pointes sur l'ECoG etaient les injections de substances convulsivantes, le pentylenetetrazol, la methionine sulphoximine et fluoroacetate, l'application de picrotoxine et l'implantation bilaterale de cobalt. Ces resultats suggerent que le rat n'est pas une espece appropriee pour une etude detaulee de la production de pointe-ondes. RESUMEN Se han examinado, en la rata, los efectos de diversos procedimientos utilizados en otros animales de experimentation, para inducir complejos punta-onda. Se registraron polipun-tas en el ECoG tras la administration sistemica de medicaciones convulsivogenas (pentilentetra-zol, metionina sulfoximina y Quoracetato) y tras la aplicacion topica de picrotoxina o la implantacidn bilateral de cobalto. La aplicacion topica de estrogenos conjugados en ambas cortezas frontales produjo complejos punta-onda lenta independientes que no mantienen las frecuencias de 3 a 5 ciclos por segundo. Estos resultados sugieren que la rata no es una especie adecuada para un estud10 detallado de la production de complejos punta-onda. ZUSAMMENFASSUNG Die Wirkungen verschiedener Verfahren, spike-wave-Komplexe imTierexperiment hervor-zurufen, wurden bei der Ratte untersucht. Systemische Convulsiva, Pentylentetrazol, Methioninsulphoximin und Fluoracetat, lokales Picrotoxin und bilaterale Kobaltimplantate verursachten polyspike-Entladungen im ECoG. Die lokale Applikationen konjugierter Ostro-gene auf den frontalen Cortex beider Seiten rief einzelne spike- und slow-wave-Komplexe her-vor, die sich nicht in einem 3 bis 5/sek.-Rhyth-mus wiederholten. Diese Ergebnisse lassen vermuten, dass die Ratte nicht das geeignete Tier ist, die spike-und-slow-Entstehung detail-liert zu untersuchen.