cssi/SciSciGPT-SciSciNet huggingface dataset:
Woody understory response to changes in overstory density: thinning in Allegheny hardwoods.

Understanding the effects of silvicultural treatments on understory vegetation is important in predicting the consequences of such treatments, not only on regeneration but also on wildlife habitat, visual qualities, and recreation. We sought to develop an empirical model of understory response that could be generalized to other forest types. We analyzed understory populations of tree species for 15 years following thinning to different residual relative densities in 50- to 55-year-old Allegheny hardwoods. The average number of stems 1 ft (0.3 m) tall to 1 in (2.5 cm) dbh increased for 3 to 5 years after thinning and then leveled-off or decreased after 10 or 15 years. The greatest density of understory stems developed at low residual density. In stems 1 to 3 ft (0.3 to 0.9 m) tall, the densities of shade-tolerant species were unresponsive to thinning while the shade-intolerant were most responsive. The shade-intolerant and -intermediate species increased in importance over time in the more heavily thinned treatments. In the 3 ft (0.9 m) tall to 1 in (2.5 cm) dbh size class, shade-intolerant and -intermediate species were more responsive to thinning than tolerant species, but shade-tolerant species remained more important numerically throughout the study. Ingrowth to > 1 in diameter classes was greatest by shade-tolerant stems, increased over time, and was enhanced by thinning. We used repeated measures analysis of variance to model the number of stems in these three size classes and three shade-tolerance classes as a function of residual relative density at thinning and time since treatment. These models explained 0.08 to 0.80 of the variation in stem numbers, depending on the size and tolerance class. These descriptions might be improved by reference to prior conditions of the regeneration or interfering herbaceous competition, but a model that required this information would not be capable of predicting responses to future treatments.
Glycoprotein synthesis in cells infected with vaccinia virus III. Purification and biosynthesis of the virion glycoprotein

A 2-step procedure was used for the purification of the vaccinia virion glycoprotein. The glycoprotein was purified according to molecular weight by SDS-polyacrylamide gel electrophoresis and then separated from three similar molecular weight proteins by SDS-hydroxylapatite chromatography. Peptide maps of tryptic digests indicated that the proteins separated by chromatography had different amino acid sequences. The molecular weight of the virion glycoprotein, determined by electrophoresis at several gel concentrations was approximately 38,500. Attempts were made to use trypsin as a probe to locate the glycoprotein within the virion. Although the glycoprotein was degraded or released by treatment of virions with trypsin under conditions in which lipid was not removed, DNA was not liberated and no loss in plaque-forming units was detected, the proteolytic activity was not selective enough for precise localization. Radioisotopic labeling experiments were carried out to determine the relative time of synthesis of the glycoprotein. These studies suggested that both the polypeptide and carbohydrate portions were formed primarily after the onset of viral DNA synthesis.
Getting blood from bone: An emerging understanding of the role that osteoblasts play in regulating hematopoietic stem cells within their niche

Blood and bone are dynamic tissues that are continuously renewed throughout life. Early observations based upon the proximity of bone and hematopoietic progenitor populations in marrow suggested that interactions between skeletal and hematopoietic elements are likely to be crucial in the development and function of each system. As a result of these morphologic observations, several groups have demonstrated that the osteoblasts play an important role in hematopoiesis by serving as a specific local microenvironment, or niche, for hematopoietic stem cells. Significant new developments in this area of active investigation have emerged since our last examination of this area in 2005. Here we discuss these new insights into the function and morphology of the hematopoietic stem cell niche, with a particular focus on cells of the osteoblastic lineage.
Calcium-Activated Myosin V Closes the Drosophila Pupil

Approximately 40 years ago, an elegant automatic-gain control was revealed in compound eye photoreceptors: In bright light, an assembly of small pigment granules migrates to the cytoplasmic face of the photosensitive membrane organelle, the rhabdomere, where they attenuate waveguide propagation along the rhabdomere. This migration results in a "longitudinal pupil" that reduces rhodopsin exposure by a factor of 0.8 log units. Light-induced elevation of cytosolic free Ca(2+) triggers the migration of pigment granules, and pigment granules fail to migrate in a mutant deficient in photoactivated TRP calcium channels. However, the mechanism that moves photoreceptor pigment granules remains elusive. Are the granules actively pulled toward the rhabdomere upon light, or are they instead actively pulled into the cytoplasm in the absence of light? Here we show that Ca(2+)-activated Myosin V (MyoV) pulls pigment granules to the rhabdomere. Thus, one of MyoV's several functions is also as a sensory-adaptation motor. In vitro, Ca(2+) both activates and inhibits MyoV motility; in vivo, its role is undetermined. This first demonstration of an in vivo role for Ca(2+) in MyoV activity shows that in Drosophila photoreceptors, Ca(2+) stimulates MyoV motility.
Initial Hardening in Quenched Gold

The effects of dispersed vacancies on mechanical properties were examined in as-quenched gold single crystals. A quench from 1000 °C produced an initial hardening of ≈200 p/mm2 at 4.2 °K. This hardening increased with the quenching temperature and could be approximated by a linear or square root dependence on the vacancy concentration. The extent of the easy glide region was found to increase without a significant change in the work-hardening coefficient. No yield drop was generated by the quench. The quenching effects were found to decrease with the test temperature below − 70 °C. The experimental results were interpreted in terms of hardening due to dispersed vacancies and/or small vacancy clusters. The kinetics of the aging at room temperature were also followed by yield stress measurements at liquid helium temperature. Der Einflus isolierter Leerstellen auf die mechanischen Eigenschaften wurde in abgeschreckten Gold-Einkristallen untersucht. Abschrecken von 1000 °C ruft bei 4,2 °K eine Anfangsverfestigung von ≈ 200 p/mm2 hervor. Die Verfestigung steigt mit der Temperatur an und kann durch eine lineare oder Wurzelabhangigkeit von der Leerstellenkonzentration angenahert werden. Es wurde gefunden, das das Ausmas der Bereiche mit leichter Gleitung ohne wesentliche anderungen des Verfestigungskoeffizienten ansteigt. Durch das Abschrecken wurde kein Abfall der Streckgrenze erzeugt. Die Temperungseffekte nehmen unterhalb −70 °C mit der Versuchstemperatur ab. Die experimentellen Ergebnisse werden mit der Verfestigung durch isolierte Leerstellen und/oder kleine Leerstellenagglomerate erklart. Nach einer Alterungskinetik bei Zimmertemperatur wurden Messungen der Streckgrenze bei der Temperatur des flussigen Heliums ebenfalls durchgefuhrt.
Measure of Nonlinearity for Estimation

Nonlinearity, among other factors, is often the root cause of difficulties in nonlinear problems. It is important to quantify a problem's degree of nonlinearity to decide a proper solution. For example, a full-blown nonlinear filter is needed in general if the estimation problem is highly nonlinear, but a quasi-linear filter (e.g., an extended Kalman filter) is sufficient for a weakly nonlinear case. This paper first surveys various measures of nonlinearity (MoNs) for different applications. For nonlinear estimation, we conclude that these MoNs are not suitable and a better measure is needed. In view of this, we propose a general MoN for estimation. It measures the mean-square closeness between a point and a subspace in a functional space. Properties and computation of this measure are studied. Numerical examples of static models for parameter estimation and dynamic models for process estimation are given to illustrate our measure.
Smoke and Mirrors: Inverting the Discourse on Tobacco

Abstract: Understanding the mechanisms that construct and maintain the taken-for-granted, “common sense” understandings of everyday life is an essential prerequisite for reconfiguring conditions in more progressive directions. Highlighting particular moments, when these processes can be made visible, and drawing appropriate insights from such interrogations is useful not only for illuminating the fundamental malleability of “common sense” (itself a crucial element of change), but also for providing suggestive strategies and tactics for effectuating change. Here the construction and reconstruction of the “common sense” around tobacco is offered as an instructive case.
The Multiple Causes of Multiple Sclerosis: The Importance of Age of Infections in Childhood

The geographic distribution of multiple sclerosis (MS) may relate to the age of inital exposure and degree of sensitization to common viruses or bacteria which have proteins with epitopes (antigenic determinants) which are homologous with potentially encephalitogenic peptides in central myelin proteins, such as basic protein and proteolipid protein. Comparable homologies may exist for the as-yet-undefined nonencephalitogenic myelin antigen(s) which evoke demyelinating factors (probably complement-fixing antibodies). Many of these homologous epitopes occur in microorganisms that also possess adjuvant activity for evoking not only the sensitized T-cells but also the antibodies that cross-react with the target antigens in central myelin. If sufficient sensitization to myelin basic protein or proteolipid protein occurs, especially in infections of young adults, the individual develops acute disseminated encephalomyelitis, exactly comparable to ordinary acute experimental allergic encephalomyelitis (EAE). If v...
Four-dimensional heteronuclear triple-resonance NMR of isotopically enriched proteins for sequential assignment of backbone atoms

Any two-dimensional NMR experiment that involves a relay step to transfer magnetization between two nuclei via an intermediate nucleus can be converted into a three-dimensional experiment where the third axis provides the resonance frequency of the intermediate spin. Indeed, many of the 3D experiments proposed so far are constructed according to this principle and have popular 2D relay analogs. For example, the 3D heteronuclear NOESY-HMQC (I-3) HMQC-COSY (4), HOHAHA-HMQC (5), and ROESY-HMQC (6) experiments are very similar to their 2D counterparts ( 6-1 I ) . Similarly, the 3D homonuclear NOESY-HOHAHA / TOCSY experiments ( 12, 13) are directly related to analogous 2D experiments (14, 15). Here we show an example where a 3D relay pulse scheme is advantageously converted into a 4D experiment. Recently, it has been demonstrated that four-dimensional NMR is a feasible and very practical approach for simultaneously reducing overlap and obtaining additional information regarding NOE interactions between amide and aliphatic protons ( 16). The 4D experiment described in this paper is of a different type and can be considered the analog of a previously published 3D relay experiment, known as HCA(CO)N ( I7,18). The new 4D experiment yields the combined information that can be obtained from the 3D HCA(CO)N experiment, and a 3D experiment known as HCACO, removing ambiguities that may be present in each of the corresponding 3D spectra. The HCA(CO)N 3D spectrum correlates the Ha and Ca resonances of one amino acid residue in a protein with the 15N resonance of the next residue, using the carbonyl resonance (CO) as an intermediate nucleus to transfer coherence from Ccu to “N, and vice versa. The HCACO spectrum correlates intraresidue Ha, Ca, and CO chemical shifts. Both 3D and 4D experiments require a protein that is labeled uniformly at a high level (>90%) with both “N and 13C. In the 4D experiment, named HCACON, the four frequency coordinates of a resonance are determined by the intraresidue HCY ( F4), Ca (Pi ), and CO ( F2) shifts and the i5N shift ( F3) of the next residue. The pulse sequence of this experiment is sketched in Fig. 1. The magnetization transfer pathway that gives rise to the desired resonances
An Equation to Simplify Correction of Range Restricted Standard Deviations and Correlations when the Population Variance is Unknown

Estimates of population, or unrestricted, variance are generally required to correct correlations for restriction in range. Several articles have been concerned with the advantages of being able to correct correlations for variables that are restricted in range but for which the population variance is not known. Methods previously suggested use a tabled function, as per Cohen (1959), to estimate the population variance. This article presents an empirically derived formula that permits an accurate determination of corrections without the use of a table.
Avoiding the "streetlight effect": tracking by exploring likelihood modes

Classic methods for Bayesian inference effectively constrain search to lie within regions of significant probability of the temporal prior. This is efficient with an accurate dynamics model, but otherwise is prone to ignore significant peaks in the true posterior. A more accurate posterior estimate can be obtained by explicitly finding modes of the likelihood function and combining them with a weak temporal prior. In our approach, modes are found using efficient example-based matching followed by local refinement to find peaks and estimate peak bandwidth. By reweighting these peaks according to the temporal prior we obtain an estimate of the full posterior model. We show comparative results on real and synthetic images in a high degree of freedom articulated tracking task.
Large-Scale Experimental Studies of Structural Control Algorithms for Structures with Magnetorheological Dampers Using Real-Time Hybrid Simulation

AbstractReal-time hybrid simulations using large-scale magnetorheological (MR) dampers were conducted to evaluate the performance of various structural control strategies to control the seismic response of a three-story steel-frame building. Magnetorheological dampers were installed in the building to limit the story drift to less than 1.5% under the design-basis earthquake (DBE). The laboratory specimens, referred to as experimental substructures, were two individual MR dampers, with the remainder of the building modeled as a nonlinear analytical substructure. The experimental technique enables an ensemble of ground motions to be applied to the building, resulting in various levels of damage, without the need to repair the experimental substructures because the damage will be within the analytical substructure. Five different damper control algorithms, including passive and semiactive control algorithms, were selected. An ensemble of five ground motions scaled to the DBE was used for the real-time hybrid...
Reconstituted P2/Myelin-Lipid Multilayers

A complex forms when bovine P2 protein is added to single-bilayer vesicles created by sonicating myelin lipids. The complex was studied by biochemical analysis, freeze-fracture (FF) and thin-section electron microscopy (EM), and by X-ray diffraction. Smaller amounts of P2 cause the vesicles to aggregate and fuse whereas larger amounts (greater than or equal to 4 wt%) cause multilayers to form. Binding saturates at 15 wt% P2. FF EM shows that large, flat multilayers form within 15 min of addition of P2. Only smooth fracture faces are seen, as expected for a peripheral membrane protein. X-ray diffraction shows a constant repeating distance in the multilayers: 86.0 +/- 0.7 A between the centers of bilayers in the range 4 wt% less than or equal to P2/(P2 + lipid) less than or equal to 15 wt%. Assuming a 53 A-thick bilayer, the space between bilayers is 33 A wide. This is a wider space than for myelin basic protein (MBP) (20-25 A wide). The respective widths are consistent with a compact, globular structure for P2 and a flattened shape for MBP. Calculated electron-density profiles of the lipids with and without P2 reveal the protein largely in the interbilayer spaces, with a small part possibly inserted into the lipid headgroup layers. The different proportions of P2 in the sciatic nerve of various species are tentatively correlated with the different average widths observed by X-ray diffraction for the cytoplasmic space (major period line) between bilayers in the respective sciatic myelins.
Exokernel: an operating system architecture for application-level resource management

Traditional operating systems limit the performance, flexibility, and functionality of applications by fixing the interface and implementation of operating system abstractions such as interprocess communication and virtual memory. The exokernel operating system architecture addresses this problem by providing application-level management of physical resources. In the exokernel architecture, a small kernel securely exports all hardware resources through a low-level interface to untrusted library operating systems. Library operating systems use this interface to implement system objects and policies. This separation of resource protection from management allows application-specific customization of traditional operating system abstractions by extending, specializing, or even replacing libraries. We have implemented a prototype exokemel operating system. Measurements show that most primitive kernel operations (such as exception handling and protected control transfer) are ten to 100 times faster than in Ultrix, a mature monolithic UNIX operating system. In addition, we demonstrate that an exokernel allows applications to control machine resources in ways not possible in traditional operating systems. For instance, virtual memory and interprocess communication abstractions are implemented entirely within an application-level library. Measurements show that application-level virtual memory and interprocess communication primitives are five to 40 times faster than Ultrix's kernel primitives. Compared to state-of-the-art implementations from the literature, the prototype exokernel system is at least five times faster on operations such as exception dispatching and interprocess communication.
Cotranslational Integration of Soybean (Glycine max) Oil Body Membrane Protein Oleosin into Microsomal Membranes

Storage triglycerides in oil seeds are sequestered in discrete organelles termed oil bodies. They are bounded by a monolayer of phospholipids in which a few distinct proteins (oleosins) are embedded. Synthesis of soybean (Glycine max) 24-kD oleosin was analyzed by in vitro transcription and translation in reticulocyte lysate in the presence of canine microsomes. Our results show that 24-kD oleosin is cotranslationally integrated into microsomal membranes. We demonstrate that oleosin is integrated into a bilayer membrane in preference to the oil body monolayer membrane, indicating that oleosin is synthesized on the endoplasmic reticulum (ER). A new model of oil body assembly involving a conformational change through initial association with the ER membrane is proposed.
Establishing Commonality Versus Affirming Distinctiveness: Patterns of Personality Judgments in China and the United States

We predicted that members of Chinese groups would tend to express personality judgments that establish commonalities among members, whereas members of American groups would tend to express judgments that affirm how members differ. We had groups of five acquaintances (23 groups at one U.S. university, 28 groups at three Chinese universities) rate their own and each other’s traits and subjected the round-robin data to social relations model and social accuracy model analyses. As hypothesized, Chinese were more likely to portray their peers as similar to themselves and to each other as indicated by greater perceived self-other similarity and less variance in target ratings; conversely, Americans were more likely to express a shared understanding of what distinguished each group member from others, as indicated by greater distinctive agreement and target variance (consensus). Collectivistic values mediated effects of country on perceived similarity; individualistic values mediated effects of country on consen...
Loss of international medical experiences: knowledge, attitudes and skills at risk

Background Despite the great influence International Medical Experiences (IMs) can have on young physicians and their impact on patients and communities, they are not offered in all training programs and are at risk of being reduced in some due to stringent guidelines for funding of graduate medical education.
Improving Veterans Affairs services by embracing a communitarian model for mental health providers.

Working as a mental health professional in the Veterans Affairs (VA) health care system can be very rewarding. Providers have the privilege of caring for America’s heroes, many opportunities to learn and implement evidence-based practices, and the ability to work in interdisciplinary teams. However, providers also face some unique challenges. VA leadership and staff can embrace a communitarian approach to professional ethics by creating opportunities for mental health professionals to engage in mutual awareness, support, and accountability. The author describes five ideas for infusing this model at VA facilities to support and strengthen the mental health workforce.
Azimuth/elevation direction finding using regular array geometries

The authors consider the problem of extending the estimation of signal parameters via rotational invariance techniques (ESPRIT) algorithm for multiple source, cochannel direction finding to the two-dimensional case (e.g., azimuth and elevation angle estimation). Two algorithms are presented, one based on the optimal (minimal variance) subspace fitting formulation of ESPRIT, and the other based on an approximation to it. The algorithms are applicable to antenna arrays composed of identical subarrays displaced in two dimensions, such as uniform rectangular phased arrays. Simulation results illustrating the relative performance of the algorithms are also presented. >
Investigating patient exclusion bias in meta-analysis

Methods To investigate how excluding patients from trials can affect the results of both trials and meta-analyses, we used 14 meta-analyses of individual patient data (IPD) that addressed therapeutic questions in cancer. These included 133 randomized controlled trials (RCT) and 21 905 patients. We explored whether exclusions were related to trial characteristics and categorized the reasons for exclusions. For each RCT and meta-analysis, we compared results of an intention-to-treat analysis of all randomized patients with an analysis based on those patients included in the investigators’ analysis. Results In all, 92 trials (69%) excluded between 0.3 and 38% of patients randomized. Trials excluding patients tended to be older and larger than those that did not. Most patients were excluded because of ineligibility or protocol violations. Exclusions varied substantially by meta-analysis, more patients tending to be excluded from the treatment arm. Comparing trial analyses there was no clear indication that exclusion of patients altered the results more in favour of either treatment or control. However, comparing meta-analysis results, there was a tendency for those based on ‘included’ patients to favour the research treatment (P = 0.03). Inconsistency of trial results was often increased as a result of the investigators’ exclusions. Conclusions Trials, systematic reviews, and meta-analyses may be prone to bias associated with post-randomization exclusion of patients. Wherever possible, the level of such exclusions should be taken into account when assessing the potential for bias in trials, systematic reviews, and meta-analyses. Ideally, trials, systematic reviews, and meta-analyses should be based on all randomized patients.
The Drosophila Metastasis Suppressor Gene Nm23 Homolog, awd, Regulates Epithelial Integrity during Oogenesis

The expression levels of the metastasis suppressor gene Nm23 have been shown to correlate positively or inversely with prognosis in different cancer cohorts. This indicates that Nm23 may be needed at different expression levels and may function differently in various tissues. Here we report a novel epithelial function of the Drosophila melanogaster homolog of human Nm23, abnormal wing discs (awd). We show a dynamic expression pattern of the Awd protein during morphogenesis of the Drosophila follicle cells during oogenesis. Loss-of-function awd mutant cells result in the accumulation and spreading of adherens junction components, such as Drosophila E-cadherin, β-catenin/Armadillo, and α-spectrin, and the disruption of epithelial integrity, including breaking up of the epithelial sheet and piling up of follicle cells. In contrast, overexpression of awd diminishes adherens junction components and induces a mesenchymal-cell-like cell shape change. The gain-of-function phenotype is consistent with a potential oncogenic function of this metastasis suppressor gene. Interestingly, we demonstrate that the epithelial function of awd is mediated by Rab5 and show that the Rab5 expression level is downregulated in awd mutant cells. Therefore, awd modulates the level and localization of adherens junction components via endocytosis. This is the first demonstration of an in vivo function of Nm23 family genes in regulating epithelial morphogenesis.
Resistance to ankle dorsiflexion in hemiparetic stroke patients

The purpose of this study was to measure, compare, and correlate on both the paretic and nonparetic sides of 20 hemiparetic stroke patients, the resistance of the ankle to dorsiflexion with the knee extended and the knee flexed. While resistance to ankle dorsiflexion was measured, the electromyographic (EMG) activity of the ankle plantar flexor muscles was monitored. EMG activitywas virtually nonexistent, except in two of the patients tested. An analysis of variance demonstrated that the resistance to dorsiflexion was significantly greater on the paretic side and with the knee extended. Resistance with the knee extended on the paretic side was significantly correlated with time since onset. The resistances of the ankle of each side with the knee in each position were significantly correlated. The results suggest that the triceps surae muscle group of the paretic side is hypoextensible compared to that of the nonparetic side. The hypoextensibility may contribute to the difficulty that stroke patients have ...
DaVinci: dynamically adaptive virtual networks for a customized internet

Running multiple virtual networks, customized for different performance objectives, is a promising way to support diverse applications over a shared substrate. Despite being simple, a static division of resources between virtual networks can be highly inefficient, while dynamic resource allocation runs the risk of instability. This paper uses optimization theory to show that adaptive resource allocation can be stable and can maximize the aggregate performance across the virtual networks. In the DaVinci architecture, each substrate link periodically reassigns bandwidth shares between its virtual links; while at a smaller timescale, each virtual network runs a distributed protocol that maximizes its own performance objective independently. Numerical experiments with a mix of delay-sensitive and throughput-sensitive traffic show that the bandwidth shares converge quickly to the optimal values. We demonstrate that running several custom protocols in parallel and allocating resource adaptively can be more efficient, more flexible, and easier to manage than a compromise "one-size-fits-all" design.
Evidence for Involvement of BH3-Only Proapoptotic Members in Adenovirus-Induced Apoptosis

Mammalian cells infected with human adenoviruses (Ads) undergo an apoptotic response as a result of expression of the viral E1A proteins, and this process is suppressed by the viral E1B-19K protein. The intermediary steps in the Ad-induced apoptosis pathway are not fully resolved. The apical step in the canonical mammalian apoptosis pathway involves functional activation of one or more of the BH3-only BCL-2 family proapoptotic proteins. Previous reports have suggested that Ad-induced apoptosis may be initiated at checkpoints downstream of the BH3-only proteins. Here, we undertook genetic and biochemical studies to determine the roles of BH3-only proteins in Ad-induced apoptosis. We examined the activities of the cellular antiapoptosis protein BCL-xL and its mutants expressed from the E1B region of the Ad5 genome. Our results showed efficient suppression of Ad-induced apoptosis by a BCL-xL mutant (mt1) deficient in interaction with multidomain proapoptotic proteins BAX and BAK but proficient in interaction with BH3-only proteins, suggesting a role for BH3-only proteins in the initiation of Ad-induced apoptosis. Further, the antiapoptotic activity of BCL-xL mt1 in Ad-infected cells was observed in spite of BAK activation as a consequence of MCL-1 degradation. Analysis of the mRNA levels of various BH3-only members by reverse transcription-PCR revealed prominent activation of the Bik gene. Further, the BIK protein was also modified into an apoptotically enhanced phosphorylated form during the viral infection. In addition to BIK, enhanced level of BIM was observed in Ad-infected cells. Between the two major E1A proteins coded by the 12S and 13S mRNAs, the 13S product appeared to contribute to the activation of these BH3-only members and apoptosis during viral infection. Depletion of BIK by the use of small interfering RNA reduced the level of Ad-induced apoptosis. Our results are consistent with a model that activation of the BH3-only members may initiate Ad-induced apoptosis.
MATING TYPE AND SPORULATION IN YEAST. II. MEIOSIS, RECOMBINATION, AND RADIATION SENSITIVITY IN AN αα DIPLOID WITH ALTERED SPORULATION CONTROL

ABSTRACT In wild-type S. cerevisiae , diploid cells must be heterozygous at the mating-type locus in order to sporulate. In the preceding paper, we described a number of mutants (CSP mutants), isolated from nonsporulating aa and αα parent strains, in which sporulation appeared to be uncoupled from control by mating type. The characterization of one of these mutants ( CSP1 ) is now extended to other processes controlled by mating type. This mutant is indistinguishable from αα cells and unlike a α cells for mating factor production and response, zygote formation, intragenic mitotic recombination, and for X-ray sensitivity. The mutant apparently undergoes a full round of DNA synthesis in sporulation medium, but with delayed kinetics. Only 20% of the cells complete sporulation. Among spores in completed asci, the frequency of both intra- and intergenic recombination is the same as it is for spores produced by a α cells. However, experiments in which cells were shifted from sporulation medium back to minimal growth medium gave a frequency of meiotic recombination between ade2 or leu2 heteroalleles only 25% to 29% as high for CSP1 αα diploid or CSP1 aa disomic cells as for a α diploid or disomic cells. Because the latter result, indicating recombination defectiveness, measured recombinant production in the entire cell population, whereas the result indicating normal recombination sampled only completed spores, we infer that all meiotic recombination events occurring in the population of CSP1 αα cells are concentrated in those few cells which complete sporulation. This high degree of correlation between meiotic recombination and the completion of meiosis and sporulation suggests that recombination may be required for proper meiotic chromosome segregation in yeast just as it appears to be in maize and in Drosophila
Is acute cardiac rejection a model of myocarditis in humans

Both acute cardiac rejection and acute idiopathic myocarditis may present with similar clinical signs, including heart failure. Morphologically, both may be defined as an inflammatory infiltrate (predominantly T lymphocytes) of the myocardium causing injury to adjacent myocytes. In both cases, the diffuse inflammatory infiltrate involves the endocardium, myocardium and pericardium. The morphological sequence of progression is similar. Acute rejection appears to be a good morphological model of myocarditis. From the acute rejection model it is known that myocardial damage must be diffuse and with considerable necrosis before heart failure occurs. It follows that patients suspected of having myocarditis and presenting in heart failure would be expected to have the equivalent of ‘moderate rejection’ and not a small focus of inflammatory cells on which the endomyocardial biopsy diagnosis of myocarditis is sometimes made. Such focal myocarditis may result in a clinical presentation of arrhythmias, but should not cause florid heart failure. If heart failure is present, other causes for it should be sought before a diagnosis of myocarditis is made.
Immunity of Allograft Rejection: An Overview

Transplantation between genetically disparate individuals of the same species evokes numerous changes in the host and the graft. In general, the outcome of a transplanted organ is determined by two closely interrelated components. The first component is the biology of the foreign graft (i.e., type of organ and its macro-and microenvironments, the anatomic location, the type of vascular connection, the circumstance surrounding organ harvest and transplant, and the genetic differences between the donor and the recipient). The second component is the nature and intensity of immune responses that develop in the recipient after encountering that specific foreign tissue. The immunity of allograft rejection involves a number of powerful, complex, interrelated, and well-orchestrated immune mechanisms and is only partially understood. This destructive immune response, if left unchecked, can and almost universally does, lead to complete destruction of the transplanted organ over time. This chapter offers an overview of the features and mechanisms of the immune system that work in concert to interact with and reject the organ allograft. Subsequent chapters will describe the role of distinct components that affect the immunology characteristic of the rejection response.
Adapting to multiple personalities: Cbl is also a RING finger ubiquitin ligase.

Sibyls were prophetesses of the ancient Greek and Roman legends. The Cumaean Sibyl was the best known prophetess who oiered to sell her collection of nine books of prophecies ^ the `Sibylline Books' ^ to the Roman king Tarquinius Prisus. Having been denied her asking price for the collection, the Sibyl sequentially burned six of the nine books until King Tarquin oiered to pay four times the original asking price for the remaining three books. King Tarquin's refusal to purchase the books resulted in the permanent loss of most Sibylline prophecies. Perhaps the lost Sibylline prophecies would have foretold the discovery of Cbl ^ Sibyl's modern-day homonym. Unlike the Sibylline Books where twothirds of the pre-existing information was lost forever, our ¢rst encounter with Cbl began with the discovery of its N-terminal one-third (aa 1^357) in the form of oncogenic v-Cbl, residing in the genome of the Cas NS-1 murine retrovirus [1]. Our understanding of Cbl has since grown at an incredible rate. Not only were the remaining C-terminal two-thirds of Cbl found that were absent in v-Cbl [2], two new Cbl family members [3,4] and their homologues were also discovered in three other species [2,5,6]. We also learned that Cbl possesses a divergent SH2 domain in its N-terminus [7] and that this unusual SH2 domain complex binds to and functions as a negative regulator of receptor and cytoplasmic protein tyrosine kinases (PTK) (reviewed in [8^12]), perhaps by positioning the targeted phosphoproteins in close proximity to the RING ¢nger ubiquitin ligase domain [13]. This review will summarize our current knowledge of Cbl domain structures and their interactions with signaling proteins that may serve as targets or eiectors of Cbl.
Toward better case study research

Case study research can make important contributions to the field of professional communication if the research is carried out with rigor. The paper discusses inaccurate uses of the term "case study" and then presents ideas for conducting more rigorous case studies. Advantages and disadvantages are described, as well as typical techniques, such as interviews, logs, and visual and verbal protocols.
SURFING ON SOLITARY WAVES

The steady motion of a flat surfboard propelled by a solitary wave is considered. The shape of the free surface and the flow of the fluid are determined numerically by series truncation for flows without spray or splash. These flows all bifurcate from the uniform horizontal flow at the critical value of the Froude number. Various limiting cases of these special flows are described analytically. Flows past submerged hydrofoils are also discussed.
Functional signatificance of synaptic depression between cortical neurons

Intracortical synapses exhibit several forms of short-term plasticity that cause synaptic efficacy at any given time to depend on the previous history of presynaptic activity. We have measured synaptic transmission between layer 4 and layer 2/3 in slices of rat visual cortex and used the data to construct an accurate mathematical description of intracortical short-term synaptic plasticity. These data show rapid synaptic facilitation and three forms of synaptic depression differing in their rates of onset and recovery. The dominant effect seen is overall synaptic depression that causes steady-state synaptic efficacy to decrease as a function of presynaptic firing rate. At high rates, the steady-state efficacy is inversely proportional to firing rate which implies that cortical synapses do not convey information about the magnitude of sustained high firing rates. However, this same dependence means that, for transient signals, synapses convey information about fractional rather than absolute changes in presynaptic firing rates. We explore the functional significance of this result including its implications for spike-rate adaptation and mechanisms that produce directional selectivity in visually responsive neurons.
Behavioral ecology and optimality: Seeking alternative views

Abstract Compositional analysis were undertaken to understand if Tusayan Virgin Series ceramics were being traded between southern Nevada and the St. George Basin during the Pueblo III period to counteract the loss of a diverse resource base after the collapse of the trade networks with the Arizona Strip. This study suggests that Tusayan Virgin Series ceramics were not traded between the two regions and that ecological models of the economy may not fit preconceived notions of logical responses or optimality. The Uncertainty Avoidance Index is explored as a useful tool for understanding the psychological reasons behind less than optimal behavior.
Effect of Surface Gravity Waves on Near-Surface Atmospheric Turbulence

As the wind blows over the ocean surface, wind-waves are first generated as tiny ripples (gravity-capillary waves), and their spatial/temporal scales gradually increase with fetch. Once developed, these wind waves play a significant role in the air-sea fluxes of momentum and energy, and modify the near surface atmospheric turbulence and the mean wind profile. This coupled system of wind and waves occurs over a wide variety of spatial and temporal scales. The momentum and energy fluxes from wind to surface gravity waves are mostly determined by the wave-induced pressure, that is, the pressure component that is linearly correlated with the surface wave elevation, evaluated at the water surface. Our current predictive capability of this wave-induced pressure component is far from satisfactory because very little is known about the structure of the wavw-induced flow in the atmospheric surface layer or how this flow affects the structure of the surface-layer turbulence.
Regulation of alveolar macrophage and type II cell DNA synthesis: effects of ozone inhalation

A characteristic reaction of the lung to inhaled ozone is an increase in the number of type II epithelial cells and alveolar macrophages (AMs). In the present study, we analyzed mechanisms regulating this response. Acute exposure of rats to ozone (2 parts/million, 3 h) induced expression of proliferating cell nuclear antigen, a marker of cellular proliferation, in both type II cells and AMs. This was maximum 48 h after ozone inhalation. Type II cells and AMs isolated from treated rats at this time also incorporated significantly more [3H]thymidine ([3H]TdR) than cells from control animals. When type II cells and AMs were cocultured, a synergistic increase in [3H]TdR uptake was observed. This appeared to be due to increased DNA synthesis by both cell types. Thus [3H]TdR incorporation by type II cells and AMs cocultured with mitomycin C-treated AMs and type II cells, respectively, was elevated compared with cells cultured alone. Type II cells and AMs plated onto tissue culture inserts, as well as culture supernatants from these cells, were found to stimulate DNA synthesis in AMs and type II cells, respectively. In addition, crude membrane preparations from these cells exhibited growth-promoting activity. Thus the mitogenic effects of both cell types appeared to be mediated by soluble factors and membrane-associated molecules. Ozone inhalation resulted in an increase in the mitogenic activity of AMs treated with mitomycin C and plated on tissue culture inserts toward type II cells and of type II cell culture supernatants toward AMs. These data suggest that type II cell and AM proliferation contributes to the regulation of the number of cells in the lung under normal homeostatic conditions and after ozone-induced injury. Moreover, type II cells and AMs produce paracrine mediators that contribute to cellular proliferative responses.
The Discfold Facies

The structure of the eastern portion of the area covered by Plate 1 can be described broadly as a homocline. Its dip is rather uniform to the east (Fig. 66), but its complexity varies drastically and discontinuously across strike. To the west it is relatively simple. As one walks from the crest of Svarthammer anticline on Falkfangerho eastward to Tyrikvamfjellet and Hogho, one passes steadily upward in the rock column from flagstone of the Indre Kam formation into schist and amphibolite of the Kam Tjern formation.
Increasing Manufacturing Productivity Using Human Factors Principles

Justifying the premium cost of applying human factors principles in the manufacturing workplace has been a major problem. The traditional, objective, cause-and-effect analyses are not applicable due to the lack of data. IBM Boulder developed an alternative – a subjective method of cost justification. Measurement of actual data has verified paybacks of the premium cost due to human factor considerations of less than one year. This paper discusses design highlights from having applied human factors principles to one manufacturing line.
A Critique of Methods in the Scholarship of Teaching and Learning in Philosophy

The goal in this article is to offer a vision for a scholarship of philosophical learning both that philosophers find plausible and helpful and that utilizes our disciplinary skills and knowledge to produce useful insights into how students learn philosophy. Doing so is a challenge because philosophers typically and historically conceive of our work as being properly done in the proverbial armchair, that is, done without being tied to empirical data. To begin, I look at how working from the armchair has typically led to three types of philosophy pedagogy research and I show ways that each can be done well and the limitations of each. Ultimately, I argue that, while useful and revealing in some ways, the techniques typically fail to illuminate where students are in their learning, habits, dispositions and skills. I then briefly explore the use of think alouds, arguing that they offer one viable path to a scholarship of learning in philosophy that allow philosophers to use our own disciplinary skills to make the thinking of our students visible in ways that will help us be clearer about where they are and where we are, so we can better determine how to help them improve. Keywords: methods, philosophy, pedagogy, think alouds, student learning, armchair philosophy, critique EDITORS' NOTE This article included embedded videos. To view the videos linked from within the PDF, download the PDF and click the links. If you stay within the preview page, you'll have to right-click the links and open them in a new window.
Rapid discovery of death ligands with one-bead-two-compound combinatorial library methods.

The one-bead-one-compound (OBOC) technology enables one to generate thousands to millions of chemical molecules on resin beads (90 μm diameter) such that each bead displays 1013 copies of the same chemical entity. Whole-cell binding assays have been developed to screen OBOC combinatorial libraries for ligands that bind to specific cell surface receptors. While very powerful, this screening method does not address the downstream cell signaling properties of the binding ligand. We have modified the OBOC technology by introducing a fixed known cell adhesion ligand to the outer layer of each bead. This one-bead-two-compound (OB2C) library configuration allows the bound cells to interact with the random immobilized chemical molecules on each bead. The bound cells can then be probed for specific cellular responses such as apoptosis and activation or inhibition of a specific cell signaling pathway. To validate this concept, an OB2C combinatorial library was created such that a random hexapeptide plus a high affi...
Widespread Distribution of Poliomyelitis in Households Attacked by the Disease.

SummaryA study of 4 households attacked by poliomyelitis provided evidence of widespread distribution of virus in the members of these units. There were 20 members in these households; 16 had poliomyelitis virus in their intestinal discharges; 7 had virus in the oropharynx.