cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of acute hypoxia on metabolism and ventilation in awake piglets

Abstract We studied the effect of acute sustained hypoxia on ventilation (V e ) and oxygen consumption (V O 2 ) over one hour during quiet wakefulness in young (6 days) and older (6 weeks) piglets in thermoneutral conditions during baseline, moderate hypoxia(Pa O 2 ≈ 45 mmHg). During severe hypoxia, ventilation and pH increased while Pa CO 2 decreased in both age groups. Blood gas changes(↓PA CO 2 , ↑pH), but not ventilatory changes, were greater in the older piglets(P O 2 decreased similarly (− 30%) whileV e /V O 2 rose over 160% in both age groups. During moderate hypoxia, changes in blood gas, V e , andV O 2 were in similar direction, but smaller in magnitude. We conclude that: (1) changes in blood gases andV O 2 are amplified by maturation and severity of hypoxia and (2) blood gas changes are greater in older vs young piglets despite similar ventilatory responses suggesting maturational differences in CO 2 production or dead space ventilation.
Regulation of α-Helical Coiled-coil Dimerization in Chicken Skeletal Muscle Light Meromyosin *

The dimerization specificity of the light meromyosin (LMM) domain of chicken neonatal and adult myosin isoforms was analyzed by metal chelation chromatography. Our results show that neonatal and adult LMMs associate preferentially, although not exclusively, as homodimeric coiled-coils. Using chimeric LMM constructs combining neonatal and adult sequences, we observed that a stretch of 183 amino acids of sequence identity at the N terminus of the LMM was sufficient to allow the adult LMM to dimerize in a non-selective manner. In contrast, sequence identity in the remaining C-terminal 465 amino acids had only a modest effect on the dimerization selectivity of the adult isoform. Sequence identity at the N terminus also promoted dimerization of the neonatal LMM to a greater degree than sequence identity at the C terminus. However, the N terminus had only a partial effect on the dimerization specificity of the neonatal sequence, and residues distributed throughout the LMM were capable of affecting dimerization selectivity of this isoform. These results indicated that dimerization preference of the neonatal and adult isoforms was affected to a different extent by sequence identity at a given region of the LMM.
Beyond Bosnia: Contextualizing the Politics of Southeastern Europe.

are covered in comparative politics surveys of Eastern Europe, the region usually receives far less space on the syllabus than the more developed "northern tier" states of Poland, the Czech Republic, Hungary, and Slovakia. However, there are compelling reasons for bringing the study of Europe's southeast into the mainstream of comparative politics and for making the region a focus of undergraduate and graduate courses. In the first place, the region provides many cases of issues of pressing interest to comparativists: identity politics, nationalism, mass mobilization, state-building, and regime change, among many others. Moreover, the difficult transitions experienced in the Balkans are clearly the rule rather than the exception in Eastern Europe. Indeed, the southeast is a far more representative example of post-communism than the northern tier states. The four "Visegrad" countries, in which foreign interest and investment have been highest, are actually rather unreliable indicators of the key challenges confronting post-communist states; with the exception of Slovakia, none of these countries faces the major problems bedeviling states in most other parts of the former communist world.
Regulation, Role, and Targeting of Akt in Cancer

The serine-threonine kinase AKT, also known as protein kinase B (PKB), was identified in 1977 as the proto-oncogene of the v-Akt oncogenic murine thymoma virus. Subsequent research has demonstrated that genetic events activating Akt occur in most types of cancer. Activation of Akt promotes many of the processes critical to the malignant phenotype. Thus, Akt is an attractive therapeutic target for cancer. However, its critical role in many physiologic processes suggests that achieving an acceptable therapeutic index with Akt inhibitors may be a challenge. In Journal of Clinical Oncology, Yap et al report the results of, to our knowledge, the first-in-man phase I clinical trial of Akt inhibitor MK-2206. In addition to determining the maximum-tolerated dose of MK-2206, the study included a pharmacodynamic analysis of hair follicles in the majority of patients, and of paired tumor biopsies in a maximum-tolerated dose expansion cohort. The results provide strong evidence that significant inhibition of Akt is feasible in patients. However, limited single-agent antitumor activity was observed. This Understanding the Pathway report will highlight the current understanding of the role and regulation of Akt signaling in cancer and the implications for further development of therapeutic strategies against this critical signaling node. Akt is a member of the AGC family of protein kinases. Akt has three isoforms: Akt1 (also known as PKB ), Akt2 (PKB ), and Akt3 (PKB ). Akt1 and Akt2 are expressed in most tissue types; Akt3 expression is generally restricted to neuronal tissue and the testes. The three isoforms share over 80% homology and are characterized by three conserved functional domains: an amino-terminal pleckstrin homology (PH) domain that regulates intracellular trafficking of the protein, a central catalytic domain, and a carboxy-terminal regulatory domain. Activation of all three Akt isoforms is dependent on phosphatidylinositol 3-kinase (PI3K). PI3K is stimulated by a variety of signals, including growth factor and G protein–coupled receptors on the cell surface. Activation of PI3K results in the generation of 3 phosphorylated phosphatidylinositols in the cell membrane, which recruit Akt and other PH domain–containing proteins to the cell membrane. At the cell membrane, Akt comes into proximity with PDK1, another PH domain–containing serine-threonine kinase, which phosphorylates Akt at the Thr308 residue of its catalytic domain. The activated conformation of Akt is further stabilized by phosphorylation at the Ser473 residue, either by the mammalian target of rapamycin complex 2 in response to growth factor stimulation or by
Why does slug length correlate with speed during migration inDictyostelium discoideum

Taking advantage of the fact that static electricity in plastic Petri dishes will produce very long, thin migrating slugs ofDictyostelium discoideum, it was shown that these slugs moved particularly rapidly. This is consistent with the demonstration of Inouye and Takeuchi that speed varies with length for slugs migrating on agar. Based on these observations it is suggested that slug speed is controlled by both the resistance at the tip and some factor that correlates With slug size, such as the concentration of endogenously produced ammonia
ULTRA-LIGHT EARPHONES IMPROVE NEONATAL BRAINSTEM AUDITORY EVOKED RESPONSE (BAER) TESTING

Detection of BAER waveforms in the neonatal ICU is hampered by the large size of the typical "pediatric earphone" normally used (TDH-39). Earphone size prevents adequate stability of sound intensity under all ICU conditions without disrupting or handling the infant during a BAER test. Also, large speaker coils must operate at higher currents; this induces stimulus artifacts which distort the cochlear microphonic and the auditory nerve response components (CM and Wave I). This is especially true at the intensities needed to test infants. We found that essentially the same BAER waveform, without significant stimulus artifacts, is produced using miniture ultra-lightweight earphones made with samarium cobalt magnets (<0.2 oz.) (Sony or Recoton). To insure reproducibility of click intensity, the earphone was mounted in a standard feeding nipple that had cotton stuffed loosely in the nipple stem. An "acoustic chamber" formed by the application of micropore tape placed around the nipple flange permitted the earphone to rest lightly over the external auditory canal without introducing mechanical distortions. These methods allowed us to test reliably all infants in isolettes, head boxes and on ventilators without the need to handle the infant excessively during data acquisition. We believe that these simple and inexpensive earphones significantly improve results obtained from BAER tests performed in the Neonatal ICU.
Nonconservative forcing and diffusion in refractive optical traps

Refractive optical trapping forces can be nonconservative in the vicinity of a stable equilibrium point even in the absence of radiation pressure. We discuss how nonconservative 3D force fields reduce, near an equilibrium point, to circular forcing in a plane; a simple model of such forcing is the refractive trapping of a sphere by four rays. We discuss in general the diffusion of an anisotropically trapped, circularly forced particle and obtain its spectrum of motion. Equipartition of potential energy holds, even though the nonconservative flow does not follow equipotentials of the trap. We find that the dissipated nonconservative power is proportional to temperature, providing a mechanism for runaway heating instability in traps.
The nature of the requirement of Saccharomyces carlsbergensis for vitamin B6.

Abstract Saccharomyces carlsbergensis 4228, an organism widely used for determination of vitamin B6, grows well without this vitamin if thiamine is also omitted from the basal medium, and an inoculum grown in a thiamine-low medium is used. Thiamine inhibits growth when added to such a medium. The thiazole moiety of thiamine, but not the pyrimidine, is also inhibitory, but less so than thiamine itself. Growth inhibition by thiamine is prevented by vitamin B6. At low concentrations of thiamine, the amount of vitamin B6 required for growth increases with the thiamine concentration; at concentrations of thiamine above 1 μg./10 ml. the vitamin B6 requirement for growth remains essentially constant. Since these higher concentrations of thiamine have been used in methods that utilize this organism for determination of vitamin B6 (1,2), the validity of these methods is confirmed. In the presence of thiamine, growth was also permitted by additions of the thiamine antagonist, neopyrithiamine. In this case, however, the relationship was fully competitive; i.e., the amount of neopyrithiamine required for growth increased regularly with the thiamine concentration. At concentrations considerably higher than those required for growth, neopyrithiamine again inhibited growth, and this inhibition was prevented by an increase in the thiamine concentration. Thus neopyrithiamine acts by lowering the effective thiamine concentration to subinhibitory levels; if excessive amounts are used, it prevents essential metabolic functions of thiamine and itself becomes toxic. The mechanism by which vitamin B6 prevents thiamine toxicity is not known. The appearance of a requirement for certain growth factors because of inhibitory effects of other metabolically important compounds, rather than because of an intrinsic inability of the organism to synthesize the growth factor, may be much more common than the few recorded instances of this phenomenon indicate.
The rationale for aluminum absorption control in early stages of alzheimer disease

Abstract The role of aluminum as a link in the chain of events leading to progressive degeneration of the brain and dementia has been tested by lowering the postprandial aluminum peak in the serum. The progression of symptoms has been slowed down indicating that aluminum plays a role in the multifactorial etiology of Alzheimer Disease.
Adenoviral ElA-associated protein p300 as a functional homologue of the transcriptional co-activator CBP

The 265K nuclear protein CBP was initially identified as a co-activator for the protein kinase A (PKA)-phosphorylated form of the transcription factor CREB. The domains in CBP that are involved in CREB binding and transcriptional activation are highly related to the adenoviral E1A-associated cellular protein p300 (refs 2, 3), and to two hypothetical proteins from Caenorhabditis elegans, R10E11.1 and K03H1.10 (refs 4 and 5, respectively), whose functions are unknown. Here, we show that CBP and p300 have similar binding affinity for the PKA-phosphorylated form of CREB, and that p300 can substitute for CBP in potentiating CREB-activated gene expression. We find that E1A binds to CBP through a domain conserved with p300 and represses the CREB-dependent co-activator functions of both CBP and p300. Our results indicate that the gene repression and cell immortalization functions associated with E1A involve the inactivation of a family of related proteins that normally participate in second-messenger-regulated gene expression.
Cultivating the Self in Cyberspace: The Use of Personal Blogs among Buddhist Priests

This research attempts to understand the Internet religious practices from the immanent perspective. Since previous research on this subject has been mainly transcendental, this study offers a challenging view using a different perspective. The exploration of cultivating the self in cyberspace revealed that the degree of self-cultivation varies contingent upon the given conditions and the technologies that the priests practice to interact with them. This research has a potential to further the exploration of the interaction of cyberspace and the inner self, expanding the boundary of the study beyond online religious practices. When cyberspace and the self are understood in the plane of consistency, the range of the study about the engagement of the self in the new media can be opened out. Understanding the notions of the process of territorializing intensities and technologies of the self, the engagement of the self in cyberspace can be more specifically developed.
Ionic and non-ionic compounds in the germination of spores of bacillus megaterium texas

Germination requirements of suspensions of spores of Bacillus megaterium, Texas strain, an “l-alanine-inosine type”, have been examined employing a decrease in optical density as the criterion of germination. In deionized water, l-alanine and inosine were devoid of germinative powers. They were effective only in conjunction with any one of a large variety of salts. Data are given for germination by the monovalent and divalent alkali metal chlorides. The potassium halides were germinative; potassium fluoride was the best. Salts of organic acids, including fatty acids and polycarboxylic acids, were germinative. The need for inosine could be bypassed by various salts, e.g., ammonium propionate or salts of dipicolinic acid. Also, l-alanine was replaceable by a variety of amino acids, provided suitable ions were present. In the presence of magnesium chloride, sodium dipicolinate could substitute for either inosine or l-alanine, but not both. Salts of n-hexylamine and n-heptylamine bypassed the need for both l-alanine and inosine. A primary role for ions in germination is proposed and a secondary, augmentative action is attributed to l-alanine and inosine.
Marketing AIDS Prevention: The Differential Impact Hypothesis Versus Identification Effects

Social marketing may be used to change people's AIDS risk perceptions. Two competing hypotheses address those perceptions. First, the impersonal impact hypothesis proposes that mass communication affects judgments of societal risk while interpersonal communication affects judgments of personal risk. Second, the differential impact hypothesis proposes that the media affect personal risk judgments when the message involves a personalized depiction. Identification is proposed as the mechanism. These predictions were investigated in two studies of Magic Johnson's announcement that he was HIV positive. The first study compared the effects of naturally occurring mass and interpersonal communication. The second study assigned students to watch tapes of the news story or to participate in interpersonal discussion. The results are generally inconsistent with the differential impact hypothesis. Because respondents’ identification with Magic Johnson was a determinant and mediator of social and personal concern in both studies, the results support the importance of the identification process.
Cognitive Therapy: A Well‐Thought‐Out Strategy

Designing strategies for nursing care is a complex process. Carefully evaluating the nature of the client's problem is a beginning step in the eventual design of a strategy. In this case a careful review of the problem of depression led to the discovery of faulty reasoning mechanisms used by clients who experience depressive episodes. Once the theoretical roots of the problem become clear, the design of the strategy is a natural progression. The success or failure of a strategy is measured by research. The author uses selective examples to describe how various aspects of cognitive therapy can be incorporated into the client's plan of care.
HIV-Related Cognitive Dysfunction: Implications for Aging and Social Work

Half of adults with HIV experience HIV-Associated Neurocognitive Disorder (HAND). HIV infects microglial and macrophages in the brain, resulting in a neurotoxic environment that inhibits the function of neurons, thus impairing cognition. Social workers require an understanding of how HIV-related cognitive dysfunction develops within the larger context of mental illness, substance use, and socioeconomic status. This article briefly reviews the clinical diagnosis of HAND and some interrelated neurobiological and psychosocial factors. Research implications for improving cognition are important as one considers: (1) The impact of the aging process on cognition and (2) the growing number of older adults with HIV.
Oncoapoptosis: a novel molecular therapeutic for cancer treatment.

Many cancer cells refractory to radiation treatment and chemotherapy proliferate due to loss of intrinsic programmed cell death (apoptosis) regulation. Consequently, the resolution of these cancers are many times outside the management capabilities of conventional therapeutics. We have developed a replication defective herpes simplex virus system which triggers apoptosis specifically in transformed human cells, termed oncoapoptosis. Susceptibility to virus induced cell death is dependent on the p53 protein status in the tumor cells, indicating specific targeting of the treatment. Primary cells which produce functional p53 are resistant to oncoapoptotic killing but not to apoptosis induced by nonviral environmental factors. Thus, induction of apoptosis by nonreplicating virus is a feasible molecular therapeutic approach for killing human cancer cells. Our findings have important implications in designing novel virus-based anticancer strategies. © 2009 IUBMB IUBMB Life, 62(2): 87–91, 2010
Wheat Stem Sawfly Parasites, Collyria calcitrator and Pediobius nigritarsis, in Eastern United States

From 1935–38 Collyria calcitrator (Gravenhorst), a parasite of the European wheat stem sawfly, Cephus pygmaeus (L.), was released in Eastern United States by the USDA but not recovered until 1957, when adults of Collyria calcitrator were collected near Moorestown, N. J. and southeastern Pennsylvania. In 1962–63 a survey of wheat fields in Northeastern States showed that C. calcitrator was distributed throughout the range of Cephus pygmaeus and parasitized a high percentage of the larvae of this species but apparently did not attack the closely related black grain stem sawfly, Cephus tabidus (F.), as recorded in Europe. About 5% of the C. pygmaeus and 18% of the C. tabidus were parasitized by Pediobius nigritarsis (Thomson). Multiple parasitism of C. pygmaeus larvae by Collyria calcitrator and P. nigritarsis was observed. P. nigritarsis may be superior and supersede C. calcitrator when both attack the same host. Cephus pygmaeus has declined as a pest since Collyria calcitrator was introduced, but this decline may be only coincidental, since Cephus tabidus also has decreased in importance.
Refining our understanding of oceanic biogeochemistry and ecosystem functioning

On societally relevant time scales (e.g., decades to centuries), oceanic biological processes sequester large quantities of atmospheric carbon, thereby modulating C02 concentrations in the lower atmosphere [IPCC, 2001]. The complex physical and biogeochemical interactions that regulate carbon fluxes between the atmosphere and the surface ocean— apparently random physical events, fluctuations in community structure and function, natural climate cycles, and long-term changes in anthropogenic forcing—are best studied within the framework of ocean time-series observations. Such thinking led in 1988 to the initiation of the U.S. JGOFS (Joint Global Ocean Flux Study) time-series programs in the subtropical North Atlantic (BATS = Bermuda Atlantic Time-series Study) and North Pacific (HOT = Hawaii Ocean Time-series), and motivates continuing observations into the foreseeable future. After 14 years of intensive physical, biological, and biogeochemical sampling in these regions, the paradigms that initially guided our understanding and research of ocean ecosystems have been found wanting, and new perspectives have emerged to provide a stimulating foundation for continued investigations.
The applicability of second harmonic generation for in situ measurement of induction time of selected crystallization systems

The nonlinear optical technique of second harmonic generation (SHG) is introduced as a novel technique for monitoring particle formation in batch crystallizations. SHG is more sensitive and is less prone to interference than turbidometric methods. The studies presented show the applicability of SHG as a method for in situ measuring the induction time of a number of noncentrosymmetric crystal systems.
A particle model of fluid sloshing

A fluid is modelled here from a particle point of view. The forces used are attraction, repulsion, and gravity. Sloshing effects, due to particle displacement and particle influx, are demonstrated.
Thermal denaturation of DNA for immunochemical staining of incorporated bromodeoxyuridine (BrdUrd): Critical factors that affect the amount of fluorescence and the shape of BrdUrd/DNA histogram

Significant inter- and intraexperimental variations of the relative antibromodeoxyuridine fluorescence were found during measurement of DNA synthesis rates using flow cytometric analysis of 5-bromodeoxyuridine (BrdUrd)-labeled cells with an anti-BrdUrd antibody. Fluctuations in other endpoints associated with levels of denaturation (integrity of DNA and cell size) were also observed to vary widely among samples that were otherwise thought to have been treated identically. Therefore, the denaturation step has been carefully re-examined, and several critical factors were identified that influence the denaturation and subsequent binding of the anti-BrdUrd to the labeled DNA. These factors include cell density, volume of water, and pH of the sample during heating. Appropriate adjustments are now included in the protocol, resulting in more consistent anti-Brd-Urd measurements in the face of routine (and sometimes necessary) experimental variations.
Shifting to the World Englishes Paradigm by Way of the Translingual Approach: Code‐Meshing as a Necessary Means of Transforming Composition Pedagogy

“English” classrooms in U.S. institutions of higher education are not linguistically homogeneous. It is not logical, ethical, or realistic to designate “standard” English as the only discourse acceptable for the writing classroom. This praxis-oriented article chronicles a U.S. composition instructor's process of re-envisioning a formerly monolingualist, unidirectional composition curriculum through a lens that acknowledges and celebrates the World Englishes paradigm. The revised curriculum is driven by the translingual approach to composition pedagogy, which understands hybridity and fluidity as the norms of language acquisition, usage, and development, and focuses on one of the approach's practical pedagogical applications: the code-meshing strategy of writing. The article provides an overview of the author's institutional context and offers observations about how the traditional monolingualist conceptual framework has marginalized and alienated students whose language practices do not fit within it. The article explains how the translingual approach to composition pedagogy, and specifically the teaching of code-meshing as a viable communicative tool, has contributed to positive changes in students' self-perceptions as language users in and out of the classroom. The article concludes with informed reflections, from the vantage point of a composition and TESOL teacher-scholar, on further ways that the World Englishes ethos might manifest in the paradigm of U.S. composition theory and instruction.
Nicotine induced proliferation and cytokine release in osteoblastic cells

Smoking has deleterious effects on osteoporosis and periodontitis both characterized by bone loss. Smoking also interferes with the protective effect that hormone replacement therapy (HRT) has on bone loss. Our study investigated two mechanisms by which smoking may affect bone metabolism: nicotine-induced proliferation and nicotine-induced cytokine secretion in osteoblasts. Two osteoblastic cell models were used: mouse osteoblasts derived from mouse calvaria and human osteoblasts. Thymidine incorporation and immunoassays were used to evaluate proliferation, interleukin 6 (IL-6) and tumor necrosis factor alpha (TNF-alpha) secretion. Parametric and nonparametric statistical analyses were used for comparisons. The results showed that nicotine induced stimulation and inhibition of proliferation in both osteoblastic cell models. In human osteoblasts, the proliferative and inhibitory effects were also donor dependent. Il-6 secretion showed different patterns in mouse and human osteoblasts. In mouse osteoblasts, nicotine significantly increased IL-6 secretion and estradiol significantly inhibited the nicotine-induced IL-6 release. In human osteoblasts, cells derived from one subject did not respond to nicotine. However, in the second sample, nicotine increased secretion of Il-6 but estradiol did not oppose this effect. In human osteoblasts, nicotine also induced an increase in the TNF-alpha secretion and estradiol opposed this increase. These results suggest that nicotine affects bone metabolism by modulating proliferation, and Il-6 and TNF-alpha secretion. These studies provide a possible explanation for differences in bone loss among subjects who smoke and offer a possible mechanism for the oppositional effect of smoking on HRT in subjects with bone loss.
Intestinal Helminths of the Granite Spiny Lizard (Sceloporus orcutti)

Examination of the intestinal tracts of 74 granite spiny lizards (Sceloporus orcutti) from Riverside County, California (USA) revealed infection with one cestode species Oochoristica scelopori (Anoplocephalidae) and one nematode species Spauligodon giganticus (Pharyngodonidae). Helminth prevalence was 24%. The presence of Oochoristica scelopori represents a new host record.
Evaluation of Police Training on LGBTQ Issues: Knowledge, Interpersonal Apprehension, and Self-Efficacy

The present study evaluates outcomes of a five-hour training session to prepare law enforcement personnel (LEP) to work effectively with LGBTQ individuals and communities. The training was developed collaboratively with the local police department, an LGBTQ community organization, a group of diversity trainers, and the researchers. Approximately 120 LEP participated in the training, and 81 completed pre- and post-test assessments of knowledge, self-efficacy, and interpersonal comfort with LGBTQ people. Paired-sample t-tests demonstrated significant increases in knowledge and confidence in using LGBTQ-affirming tactics on the job. No significant differences were found in participants’ comfort in working with LGBTQ community members. Implications for LEP training on LGBTQ issues and research in assessing LEP for behavioral and affective change are discussed.
Preimplantation Genetic Diagnosis: Implementation of Molecular Tests in the Clinical Laboratory

As molecular diagnostic testing becomes routine in the clinical laboratory, access to comprehensive care is becoming available to a much wider patient demographic. The tests described in this review can be applied to many couples seeking preimplantation genetic diagnosis for common genetic problems. Along with the wide range of applications, these tests can be quickly and easily added to a laboratory’s test menu without purchasing new instrumentation or reagents, and most laboratory personnel are already trained in these common techniques. Comparative genomic hybridization can determine chromosome copy number, thereby allowing for selection of chromosomally normal embryos. Polymerase chain reaction (PCR), combined with capillary electrophoresis testing for cystic fibrosis, can be applied to an increasing number of patients using parental haplotype microsatellite detection and implantation of carrier and unaffected embryos. b-thalassemia can be detected by common PCR techniques using established primers. Only homozygous embryos are excluded from transfer. Duchenne muscular dystrophy can also be detected in embryos by PCR-based methods along with sex determination allowing for all female and unaffected male embryos to be transferred. The novelty of each of these tests is that each can be performed on 1 biopsied blastomere in time for the embryo in question to be implanted in the same in vitro fertilization (IVF) cycle, preventing the potentially dangerous freeze and thaw of quality embryos. Here, we review 4 molecular diagnostic assays that are suitable for implementation in the clinical laboratory.
A NEW METHOD FOR STUDYING FRACTURES OF PORCELAIN ENAMELED SPECIMENS

A process is described which locates microscopic cracks in an enamel layer. This method shows great promise in the study of different types of fractures of porcelain enameled specimens. An analysis of the stress conditions in the enamel-iron-enamel system before, during, and after thermal shock is also included.
Role of auditory cortex in the acquisition of differential heart rate conditioning.

Abstract Previous findings from our laboratory indicate that lesions of the auditory cortex disrupt the retention of differentially conditioned bradycardiac responses to tonal stimuli in rabbits. In the present experiment, the effect of lesions of the auditory cortex on the acquisition of differential bradycardiac conditioning was examined. The effect of lesions in the auditory cortex were compared to the effect produced by control lesions in the visual cortex. After 7 days of recovery, animals received 7 days of differential Pavlovian bradycardiac conditioning in which one tone (CS+) was paired with the unconditioned stimulus, and another tone (CS−) was never paired with the unconditioned stimulus. All animals demonstrated differential conditioning during the first 3 days of conditioning. On days 4–7, however, auditory cortex lesioned animals did not exhibit significant differential heart rate (HR) conditioning, whereas control animals with lesions in the visual cortex showed no loss of conditioning during this period. The loss of differential conditioning in animals with lesions in the auditory cortex appears to be due to an increase in the magnitude of the response to the CS−. These data support the hypothesis that the auditory cortex serves to inhibit the response to the CS− in differential conditioning of bradycardia to acoustic stimuli, and that the inhibition may be mediated by a descending corticothalamic or corticolimbic pathway.
NONLINEAR CIRCUIT MODEL OF LASER DIODES FOR LARGE-SIGNAL MICROWAVE PHOTONIC CAD

Abstract The laser diode nonlinear equivalent circuit model is developed to be integrated as part of a microwave computer-aided design (CAD) software. Single-mode rate equations are numerically solved using a harmonic balance (HB) simulator to predict performance of laser diodes. The laser diode physical parameters are first extracted by fitting these parameters to the measured I-V, L-I and frequency response curves. Analytically calculated photon densities are employed in the CAD simulation model as seed values for a faster convergence time. The laser diode CAD simulation results compare very well with the large-signal modulation measurements for a DH InGaAsP laser diode. Moreover, the simulated nonlinear behavior of a AlGaAs laser diode is compared against the published measured and SPICE predicted results to assess accuracy of this simulation package. Also, this laser diode CAD simulation achieves a faster convergence speed than other approaches using harmonic balance simulators.
A computational probabilistic model for creep-damaging solids

Abstract A computational probabilistic model for creep-damaging solids is presented which takes into account the effects of randomness in creep and creep-rupture properties observed in experimental data. The model is based upon concepts from continuum damage mechanics, using the well-known Kachanov creep damage model as a prototype, and assuming that various material parameters present in the problem may be considered as random variables. The mapping from the random parameter space to the solution space is computed using exact relations from probability theory. As an example, the distributions for the parameters in the model are estimated from experimental data and the probabilistic growth of creep damage in a thick-walled cylinder under internal pressure is computed.
Strain-aging in highly worked 316L stainless steel

The room temperature burst pressure of 316L stainless steel burst discs exhibited increases of about 10% over 90 days. This increase may be associated with a strain-aging phenomenon requiring the presence of carbon since tensile property instability in worked austenitic stainless steels has been reported.[1–5] The cold worked material directly beneath the score root on the burst disc could undergo the strain aging process, thus causing the observed increase in burst strength. Characterization and analysis were therefore undertaken to identify the controlling phenomena in the small heterogeneous volume that controls rupture of the burst disc. Optical metallography and magnetic measurements confirmed the presence of martensite. Nanoindentation hardness measurements were correlated with finite element simulation of the as-formed mechanical properties. A representative portion of the microstructure was then recreated through cold rolling, and subjected to real-time and accelerated thermal aging treatments and mechanical activation analysis. Saturation of strengthening was observed, and a low temperature martensite reversion anneal was found to prevent or reverse the aging process. The results are consistent with previous observations of strain aging, although in this instance the effects are observed over a 10,000-fold greater aging time. Aging mechanisms are discussed, incorporating the phenomenologies of activation enthalpy and aging kinetics. A model explaining the sensitivity of aging rate to extreme cold work-induced dislocation densities and cold work-induced vacancy content is proposed.
Contrasting Rock-Magnetic Characteristics of Two Upper Paleozoic Loessite-Paleosol Profiles

Abstract Rock magnetic results from paleosols in two North American Paleozoic loessite sequences, the Maroon Formation (Colorado) and the lower Cutler beds (Utah), indicate that bulk magnetic susceptibility (χb) variations can be complex. In Maroon Formation profiles, χb increases with increased pedogenic intensity and the major contributor to the augmentation of the χb signal is the ferrimagnetic susceptibility (χf). These trends are consistent with previous studies in which χb has been linked to climatically controlled pedogenesis. Thermal demagnetization of low-temperature saturation isothermal remanent magnetizations (SIRMs) indicates this increase correlates to a greater abundance of superparamagnetic (SP) grains, most likely magnetite, within the paleosols. The presence of coarser magnetite is indicated by the Verwey transition. In contrast, paleosols in the lower Cutler beds show a less predictable pattern in the χb signal. The paramagnetic χ (χp) and χf contribute to varying degrees to the χb within the loessite-paleosol couplets. Thermal demagnetization of low-temperature SIRMs indicates that both SP and coarser magnetite is present. There are no consistent patterns and often no significant variations in the amount of SP material within loessite-paleosol couplets. The thermal demagnetization curves for samples of the lower Cutler beds display a gradual decay of remanence and a weakly developed Verwey transition, both of which probably relate to maghemitization. Most paleosol and loessite samples differ in that there is more remanence-carrying material, predominantly hematite and some magnetite and maghemite, in the loessite. Rock-magnetic differences among loessite-paleosol couplets of the lower Cutler beds may relate to the heterogeneous distribution of pedogenic carbonate and/or to the presence of abundant hematite. This study shows that combining rock-magnetic techniques with sedimentologic evidence is important for deciphering the origin and preservation of χb patterns in ancient strata.
A Similarity-Based Aspect-Graph Approach to 3D Object Recognition

This paper describes a view-based method for recognizing 3D objects from 2D images. We employ an aspect-graph structure, where the aspects are not based on the singularities of visual mapping but are instead formed using a notion of shape similarity between views. Specifically, the viewing sphere is endowed with a metric of dis-similarity for each pair of views and the problem of aspect generation is viewed as a “segmentation” of the viewing sphere into homogeneous regions. The viewing sphere is sampled at regular (5 degree) intervals and the similarity metric is used in an iterative procedure to combine views into aspects with a prototype representing each aspect. This is done in a “region-growing” regime which stands in contrast to the usual “edge detection” styles to computing the aspect graph. The aspect growth is constrained such that two aspects of an object remain distinct under the given similarity metric. Once the database of 3D objects is organized as a set of aspects, and prototypes for these aspects for each object, unknown views of database objects are compared with the prototypes and the results are ordered by similarity. We use two similarity metrics for shape, one based on curve matching and the other based on matching shock graphs, which for a database of 64 objects and unknown views of objects from the database give a recall rate of (90.3%, 74.2%, 59.7%) and (95.2%, 69.0%, 57.5%), respectively, for the top three matchess cumulative recall rate based on the top three matches is 98% and 100%, respectively. The result of indexing unknown views of objects not in the database also produce intuitive matches. We also develop a hierarchical indexing scheme to prune unlikely objects at an early stage to improve the efficiency of indexing, resulting in savings of 35% at the top level and of 55% at the next level, cumulatively.
Roles of Pyruvate, NADH, and Mitochondrial Complex I in Redox Balance and Imbalance in β Cell Function and Dysfunction

Pancreatic β cells not only use glucose as an energy source, but also sense blood glucose levels for insulin secretion. While pyruvate and NADH metabolic pathways are known to be involved in regulating insulin secretion in response to glucose stimulation, the roles of many other components along the metabolic pathways remain poorly understood. Such is the case for mitochondrial complex I (NADH/ubiquinone oxidoreductase). It is known that normal complex I function is absolutely required for episodic insulin secretion after a meal, but the role of complex I in β cells in the diabetic pancreas remains to be investigated. In this paper, we review the roles of pyruvate, NADH, and complex I in insulin secretion and hypothesize that complex I plays a crucial role in the pathogenesis of β cell dysfunction in the diabetic pancreas. This hypothesis is based on the establishment that chronic hyperglycemia overloads complex I with NADH leading to enhanced complex I production of reactive oxygen species. As nearly all metabolic pathways are impaired in diabetes, understanding how complex I in the β cells copes with elevated levels of NADH in the diabetic pancreas may provide potential therapeutic strategies for diabetes.
Neurochemical analysis of focal ischemia in rats.

Background and Purpose: Increases in uric acid follow experimental stroke, which may be related to free radical formation by xanthine oxidase. The present study examined the time course of changes in xanthine and uric acid and their relationship to changes in the free radical scavengers glutathione, cysteine, and ascorbic acid. Methods: Focal ischemia was induced by occluding the middle cerebral artery, followed by transient occlusion of the common carotid arteries for 60 minutes. At varying time points, animals were sacrificed, and ischemic cortex was dissected. Neurochemical measurements were made by high-performance liquid chromatography with 16-sensor electrochemical detection. Results: Marked increases in uric acid were seen at all time points, with a maximal increase at 1 day and a persistent increase lasting up to 21 days. There were smaller reciprocal decreases in xanthine. Glutathione, cysteine, and ascorbic acid showed significant decreases, consistent with the generation of free radicals. Reductions in levels of cysteine and glutathione were significantly correlated with increases in uric acid levels. Conclusions: These findings confirm marked alterations in purine metabolism following focal ischemia and suggest that xanthine oxidase contributes to the generation of free radicals. (Stroke 1991;22:1548-1553)
Age differences in collaborative memory: the role of retrieval manipulations.

In two experiments, we examined age differences in collaborative inhibition (reduced recall in pairs of people, relative to pooled individuals) across repeated retrieval attempts. Younger and older adults studied categorized word lists and were then given two consecutive recall tests and a recognition test. On the first recall test, the subjects were given free-report cued recall or forced-report cued recall instructions (Experiment 1) or free recall instructions (Experiment 2) and recalled the lists either alone or in collaboration with another subject of the same age group. Free-report cued recall and free recall instructions warned the subjects not to guess, whereas forcedreport cued recall instructions required them to guess. Collaborative inhibition was obtained for both younger and older adults on initial tests of free-report cued recall, forced-report cued recall, and free recall, showing that the effect generalizes across several tests for both younger and older adults. Collaborative inhibition did not persist on subsequent individual recall or recognition tests for list items. Older adults consistently falsely recalled and recognized items more than did younger adults, as had been found in previous studies. In addition, prior collaboration may exaggerate older adults’ tendency toward higher false alarms on a subsequent recognition test, but only after a free recall test. The results provide generality to the phenomenon of collaborative inhibition and can be explained by invoking concepts of strategy disruption and source monitoring.
Separation and Analvsis of APC Combination bv d Partition Chromatography

Abstract A method of separating and analyzing mixtures of phenacetin and caffeine suitable for the analysis of APC‐type combinations is presented. The separation is obtained by means of a simplified partition chromatographic column with water as the internal phase. The analysis of the eluate is achieved by a spectrophotometric method. Results found for known simple mixtures are superior to those obtained with previous methods.
Scintigraphic and clinical findings in the Standardbred metatarsophalangeal joint: 114 cases (1993–1995)

To correlate scintigraphic and clinical findings of the metatarsophalangeal joint (MTPJ) in Standardbreds, radiographic findings in horses with confirmed MTPJ lameness, and determine if stress reaction and more advanced bone remodelling occurred in the MTPJ, medical records of 114 Standardbreds admitted between September 1993 and April 1995 in which bone scintigraphy included standing lateral and plantar views of the metatarsophalangeal joint (MTPJ) were reviewed. Images obtained using a large field of view gamma camera were evaluated visually for location, definition and intensity of increased radioisotope uptake (IRU), which was graded as mild, moderate, or intense. Clinical history and lameness examination findings were recorded and, in horses with documented MTPJ lameness, radiographic examination included the 30 degree (down-angled) dorsolateral 45 degree plantaromedial view thought to be useful in evaluation of the plantarolateral condyle of the third metatarsal bone (MtIII). The most common abnormality, IRU of the plantarolateral aspect of MtIII, was seen in 67 horses, and horses were further classified according to scintigraphic and clinical findings. In 43 horses in which lameness was not localised to the MTPJ, mild (32 horses), moderate (10 horses), and intense (one horse) IRU of MtHII was found. In 24 horses with lameness localised to the MTPJ, moderate (18 horses) and intense (6 horses) IRU was found. Of 18 horses with moderate IRU of MtIII, 9 had radiographic evidence of abnormal bony remodelling of MtIII, whereas 5 of 6 horses with intense IRU had radiographic changes. In 12 horses with MTPJ lameness and radiographic evidence of bony remodelling without fracture, radiographic changes consisted of plantarolateral subchondral radiolucency and sclerosis (7 horses), radiolucency and osteochondrosis (one horse), and plantar MtIII sclerosis without radiolucency (4 horses). In 2 horses with moderate IRU and MTPJ lameness, radiographic evidence of radiolucency and MtIII fracture was found. Of 19 starters with MTPJ lameness and IRU of MtIII, 18 horses raced after diagnosis, but only 13 remained at the same racing class or improved. The results of this study suggest the most common scintigraphic abnormality of the MTPJ, IRU of the plantarolateral aspect of MtIII, may precede other stress-related changes, and in some horses is associated with a continuum of stress-related subchondral bone remodelling which results in lameness and later radiographic changes. Since 24 of 35 horses with moderate or intense IRU of MtIII had MTPJ lameness, and 5 of 7 horses with intense IRU of MtIII had lameness and radiographic evidence of abnormal remodelling, it was concluded that horses with advanced, scintigraphic findings are more likely to have lameness and radiographic evidence of subchondral bone damage.
Water Sorption, Glass Transition, and Microstructures of Refractance Window- and Freeze-Dried Mango (Philippine ''Carabao'' Var.) Powder

Water sorption isotherms, glass transition, and microstructures of Refractance Window (RW)– and freeze-dried Philippine “Carabao” mango powders were investigated. Water sorption isotherms were developed by the isopiestic method, while thermal transition of the powders, at various water activities (a w = 0.11–0.86), was determined using differential scanning calorimetry (DSC). The sorption isotherms of RW- and freeze-dried (FD) mango powders exhibited a type III sigmoidal curve, showing higher and lower adsorption capacities above and below 0.5 a w , respectively. A significant difference (p < 0.05) in water content of RW- and freeze-dried mango powders for equivalent water activities was obtained above 0.5 a w . The onset glass transition temperature (T gi ) of RW- and freeze-dried mango powder solids decreased as the water content increased. There were no significant differences (p ≥ 0.05) in T gi of RW- and freeze-dried mango powder solids at constant water activities, except for a w = 0.86. Microscop...