cssi/SciSciGPT-SciSciNet huggingface dataset:
Effect of sympathectomy on extracellular potassium ionic activity and blood flow in experimental spinal cord contusion

Contusion injury of cat spinal cords causes a rapid loss of evoked potential transmission across the impact site. We have previously shown that this initial loss of action potential conduction is transient and recovers partially within an hour after injury, often diminishing 2–4 h later when white matter blood flow decreases from pre-injury levels of< 12ml/100 g/min to< 6ml/100 g/min. The causes of the initial and delayed loss of evoked potentials are not well understood. Although K+ release has been suggested to cause action potential blockade in spinal injury neither the levels nor time course of K+ shifts have been shown. We used K+-selective microelectrodes to record extracellular K+ activity in contused thoracic spinal white matter, comparing K+ changes with loss and recovery of somatosensory-evoked potentials and local blood flow measured by the hydrogen clearance technique. If K+ plays a role in the initial evoked potential loss, extracellular K+ should rapidly increase to levels sufficient to block action potential conduction and clear with a time course relating to evoked potentials recovery. The paravertebral sympathetic ganglia were ablated in some cats, a procedure which we have shown to prevent post-traumatic ischemia and the delayed loss in evoked potentials. If ischemia causes the delayed loss of evoked potentials by increase in extracellular K+, we should observe this is untreated injured cats but not in sympathectomized cats. In 5 cats subjected to 400 g·cm contusions, extracellular K+ in the thoracic lateral columns rose rapidly from normal pre-injury levels (3–4 mM) to a mean of 54 mM, clearing with an exponential half-time of 45 min. In 5 sympathectomized cats, extracellular K+ rose to 47 mM, clearing with a half-time of 35 min. In 5 cats that were not injured, extracellular K+ and blood flow did not change significantly. In all injured cats, evoked potentials were rapidly lost after contusion but partially recovered at 1–2 h with normalization of extracellular K+. Extracellular K+ did not again transcend 15 mM even after blood flow below 6 ml/100 g/min. Blood flow fell below 6 ml/100 g/min only after extracellular K+ returned to< 15mM. The magnitude and time course of the extracellular K+ changes can thus account for the pattern of evoked potential loss and recovery in spinal contusion. However, the delayed loss of evoked potentials cannot be related to increases in extracellular K+. With exception of a slightly faster K+ clearance rate, we found no dramatic differences in the extracellular K+ behavior between sympathectomized and untreated cats. The finding that blood flow did not fall until extracellular K+ returned below 15 mM suggests that the ionic derangements may prevent vasoconstriction for the first 1–2 h after injury.
Toward an understanding of how teachers change during school reform: Considerations for educational leadership and school improvement

As the concept of distributed leadership and its concomitant organizational structures become more prevalent in schools, studying how teacher capacity can be enhanced and can be used as a catalyst for reform is important. This article documents the nature of how the implementation of a research-validated reform influenced what teachers thought about their own teaching, student achievement, and expectations. A case study approach documented the experiences of elementary school teachers in a high poverty, historically low-performing elementary school as they implemented a researched-validated instructional reform targeting the most at-risk students in the school. The teachers experienced significant professional growth that encompassed self-doubt, resistance, acceptance, and finally advocacy. Implications for the practices that define educational leadership and school improvement are discussed in light of how successful reform can improve teacher capacity.
Fashion in Context: Apparel Styles Worn by Young Women in the United States and South Korea in the 1970s:

! e purposes of our study were to examine and compare the styles adopted by young women in the United States and South Korea in the 1970s and to interpret the reasons for the similarities and di" erences within the historical and cultural context. Fi# een women from each culture who were college students in the 1970s were interviewed. Respondents from both cultures reported that relatively casual and comfortable styles were prevalent, re$ ecting women’s changing roles. U.S. apparel styles, however, were more casual and comfortable, whereas Korean styles remained relatively feminine and formal. In the United States, individualism and masculinity were dominant cultural values that in$ uenced styles and behaviors concerning dress. Koreans held onto collectivism and femininity, yet underwent the process of melding traditional and newly adopted values due to Western in$ uences. ! is study furthers understanding of U.S. and Korean social changes through dress during the 1970s and the dynamic interplay of fashion 1 and value changes.
Rhabdomyolysis and acute renal failure following radical perineal prostatectomy

Rhabdomyolysis and acute renal failure can be a rare but serious complication resulting from compromising operative positions following some urologic and gynecologic procedures. We report a lethal case of rhabdomyolysis following radical perineal prostatectomy. The possibility of this complication must be considered prior to performing any operation in the exaggerated lithotomy position. Prevention, early diagnosis, and aggressive treatment are the keys to a successful recovery.
Purification and molecular characterization of a novel diadenosine 5′,5′′′-P1,P4-tetraphosphate phosphorylase from Mycobacterium tuberculosis H37Rv

In this study, Rv2613c, a protein that is encoded by the open reading frame Rv2613c in Mycobacterium tuberculosis H37Rv, was expressed, purified, and characterized for the first time. The amino acid sequence of Rv2613c contained a histidine triad (HIT) motif consisting of H-phi-H-phi-H-phi-phi, where phi is a hydrophobic amino acid. This motif has been reported to be the characteristic feature of several diadenosine 5',5'''-P(1),P(4)-tetraphosphate (Ap4A) hydrolases that catalyze Ap4A to adenosine 5'-triphosphate (ATP) and adenosine monophosphate (AMP) or 2 adenosine 5'-diphosphate (ADP). However, enzymatic activity analyses for Rv2613c revealed that Ap4A was converted to ATP and ADP, but not AMP, indicating that Rv2613c has Ap4A phosphorylase activity rather than Ap4A hydrolase activity. The Ap4A phosphorylase activity has been reported for proteins containing a characteristic H-X-H-X-Q-phi-phi motif. However, no such motif was found in Rv2613c. In addition, the amino acid sequence of Rv2613c was significantly shorter compared to other proteins with Ap4A phosphorylase activity, indicating that the primary structure of Rv2613c differs from those of previously reported Ap4A phosphorylases. Kinetic analysis revealed that the K(m) values for Ap4A and phosphate were 0.10 and 0.94mM, respectively. Some enzymatic properties of Rv2613c, such as optimum pH and temperature, and bivalent metal ion requirement, were similar to those of previously reported yeast Ap4A phosphorylases. Unlike yeast Ap4A phosphorylases, Rv2613c did not catalyze the reverse phosphorolysis reaction. Taken together, it is suggested that Rv2613c is a unique protein, which has Ap4A phosphorylase activity with an HIT motif.
Correlates of nonmedical use of stimulants and methamphetamine use in a national sample

Abstract Background Despite chemical similarities, ADHD stimulants and methamphetamine have distinct use patterns in the community. This study compared the characteristics of nonmedical ADHD stimulants users and methamphetamine users in a household sample. Methods In data from the 2009–2011 National Survey on Drug Use and Health, adult and adolescent stimulant users were categorized into three mutually exclusive subgroups: nonmedical ADHD stimulant users only (STM users), methamphetamine users (METH users), and both nonmedical ADHD stimulant and methamphetamine users (STM/METH users). Multivariate logistic regression analyses identified the substance comorbidity, mental health, and deviant behavior characteristics associated with these three groups. Results Compared to adolescent STM users, STM/METH users were more likely to be female, younger and uninsured while METH users were more likely to be younger, in a minority group and from a higher-income family. Compared to adult STM users, METH and STM/METH users were more likely to be male, older, uninsured, no longer married, and to be from rural areas. Adolescent METH users were more likely than STM users to report illegal drug use while adult METH users were less likely to report prescription drug use than their STM user counterparts. Overall, adult and adolescent STM/METH users were more likely to report substance use, mental health problems and deviant behaviors compared to STM users. Conclusion The characteristics of STM users differ from METH and STM/METH users, and their associations with substance use and psychiatric comorbidities differ by age. Findings have implications for understanding the risks for stimulant use in different age subgroups.
Integral sorption in glassy polymers

A new theory is developed for integral sorption and desorption processes in glassy polymers. The theory can describe both case II diffusion and the classical case of Fickian diffusion. Predictions of the theory are compared with general experimental observations.
Socioemotional Selectivity Theory and the Macrodynamics of Friendship: The Role of Friendship Style and Communication in Friendship across the Lifespan

This manuscript examines the relationships among friendship style and several relational variables across three different age cohorts from a socioemotional selectivity theory perspective. Participants (N = 144) from three age groups were asked to evaluate a significant friendship in terms of quality of talk, level of emotional support, and perceptions of homophily. The results indicated that individuals with discerning friendship styles had longer friendships than people with independent or acquisitive styles. In addition, older individuals were more likely to have a discerning friendship style. The data were inconsistent with any significant differences for homophily. Those with a discerning friendship style reported higher levels of emotional support than either independents or acquisitives. Acquisitives had the highest evaluations of the quality of talk followed by discerning and then independents. The results provide some support for socioemotional selectivity theory, although several limitations and ...
The Mechanism of Simulated Torsade de Pointes in a Computer Model of Propagated Excitation

Mechanism of Torsade de Pointes. A computer model that simulated propagation, nonuniform cycle length dependent recovery of excitability, and slow propagation during incomplete recovery in cardiac muscle has been shown to exhibit behavior similar to torsade de pointes. The conditions required in the model resembled those in long QT syndromes with regionally prolonged ventricular repolarization. In the model, premature excitation of a path with relatively short refractory periods resulted in sequential reentry of that path from a region with longer refractory periods. Sites of reentry become progressively more distal to the site of initiation. The episodes terminated spontaneously when reentrant excitation reached the end of unclosed paths or collided in closed paths. Each reentry site moved away from its initial position in the short recovery path because the distance traversed by propagation in that path exceeded the distance at which reentry occurred via the longer recovery region. The migrating sites of reentry resulted in changing QRS waveform in calculated electrocardiograms including changing QRS polarity when calculated from appropriate sites. Variations of the basic behavior occurred with nonuniform distribution of refractory periods within relatively short and long refractory period regions and included unidirectional progression of reentry sites and multiple circuits of reentry in closed paths. Termination of serial reentry at times other than those when activation reached the end of unclosed paths or collided in closed paths also occurred with nonuniform distribution of refractory periods. Findings provide a plausible explanation for the changing QRS waveform, spontaneous termination, and association of torsade de pointes with long QT syndromes but do not elucidate the mechanism of initiation of the tachyarrhythmia.
Remarks on approximate fixed points

Abstract A mapping f from a topological space X to a metric space ( M , d ) is said to be r -continuous ( r > 0 ) if for any x ∈ X there exists a neighborhood U x of x such that diam ( f ( U x ) ) ≤ r . In 1961 Victor Klee proved that an r -continuous self-mapping of a compact convex subset of a Banach space always has a γ -invariant point for any γ > r . Recently H.X. Phu extended Klee’s result to mappings that are ‘almost’ r -continuous. In this note we extend Phu’s result to compact hyperconvex spaces and to geodesically bounded complete R -trees. We also extend Klee’s stability result to certain geodesic spaces.
The Two-Shaft Industrial Gas Turbine Goes to Sea — Again

This paper gives a brief summary of the experience of the first industrial gas turbine ship, the John Sergeant, then enumerates the basic characteristics of the heavy duty gas turbine and the philosophy employed in the design. The unique features of the second-stage variable area turbine nozzle, its effects on performance, and particularly the flexible control it affords in conjunction with the controllable and reversible pitch propeller, are discussed. The philosophy of design of the solid state control, protection and sequential systems are outlined, as are the experiences to date with a number of industrial gas turbines of the two-shaft, off-shore and heavy fuel varieties. It concludes by discussing some of the considerations for burning residual fuel and boil-off from liquefied natural gas.Copyright © 1971 by ASME
Temperature effects on zooplankton respiration

Abstract 1. 1. Respiration rates were measured for adult female egg-carrying Daphnia pulex at 5, 10, 15, 20, 25, and 30°C and for Daphnia magna in similar life history stages at 5, 10, 15, 20, and 25°C. 2. 2. Respiration rates increased at increasing temperatures for both species with the rates for D. pulex being consistently greater than and increasing approximately one and one-half times faster than rates for D. magna. 3. 3. The regression equation for respiration of D. pulex was log Y = 0.08796 + 0.03862X and of D. magna was log Y = −0.08363 + 0.03940X where Y equals respiration in μl O2/mg dry wt/hr and X equals temperature in °C (5 ⩽ X ⩽ 30 for D. pulex and 5 ⩽ X ⩽ 25 for D. magna). 4. 4. Respiration rate functions were correlated with habitats, distribution, and upper temperature tolerance levels of both species.
Fish Abundance and Population Stability in a Reservoir Tailwater and an Unregulated Headwater Stream

Abstract Fish abundance and population stability were compared in the tailwater and in an unregulated tributary of Barren River Lake, a flood control reservoir in south central Kentucky. Fish abundance was greater in the tailwater near the dam and was dominated by three species common in the reservoir: gizzard shad (Dorosoma cepedianum), bluegills (Lepomis macrochirus), and white crappies (Pomoxis annularis). Three riverine suckers were less abundant in the tailwater than in the unregulated stream: northern hog suckers (Hypentelium nigricans), black redhorse (Moxostoma duquesnei), and golden redhorse (Moxostoma erythrurum). The fish populations in the tailwater, particularly common carp (Cyprinus carpio), northern hog suckers, black redhorse, and golden redhorse, were less stable than those in the unregulated stream. Population stability is defined as the extent to which fish remain in a stream section. This study suggests that the occurrence of reservoir species in the tailwater was the result of fish pa...
Teaching of ethics in biomedical engineering

The teaching of ethics in biomedical engineering is discussed with particular reference to the teaching of ethical principles in the B.S. Biomedical Engineering program at Louisiana Tech University. Consideration is given to such issues as organ transplantation and artificial organs, conducting research in new biomedical technology, the costs of health care, and developing and regulating new technology. >
Theoretical analysis of NO formation near the primary reaction zone in methane combustion

The complete kinetics of the CH4-air reaction are used to study the details of NO formation near the primary reaction zone. The species and energy conservation equations are used in the analysis, however, diffusion and heat conduction within the reaction zone are neglected. The overshoot of the concentrations of the radicals O, OH, and H over their post flame equilibrium values appears to explain the phenomenon of "prompt NO" due to the very high NO formation rate near the flame for values of the equivalence ratio ~b ~ 1.1. The effects of flame parameters on this radical overshoot are investigated. In addition, the results of the equilibrium theory, which has been used by previous authors to compute NO formation, have been compared in the detailed kinetic calculations. Computations with and without HO2 reactions, which may influence NO production through their effect on radical recombination, were compared.
Dynamic graph models

Research in graph theory has focused on studying the structure of graphs with the assumption that they are static. However, in many applications, the graphs that arise change with time, i.e., they are dynamic in nature. This is especially true of applications involving graph models in computer science. We present an expository study of dynamic graphs with the main driving force being practical applications. We first develop a formal classification of dynamic graphs. This taxonomy in the form of generalizations and extensions will in turn suggest new areas of application. Next, we discuss areas where dynamic graphs arise in computer science such as compilers, databases, fault-tolerance, artificial intelligence, and computer networks. Finally, we propose approaches that can be used for studying dynamic graphs. The main objective in any study of dynamic graphs should be to 1.(i) extend results developed for static graph theory to dynamic graphs, 2.(ii) study the properties that describe how a dynamic graph changes, 3.(iii) investigate problems and issues in dynamic graph theory that are raised by practical applications of dynamic graphs in computer science.
Smoking, oral contraceptives, and serum lipid and lipoprotein levels in youths.

Abstract To examine the effect of smoking on cardiovascular risk factors in youth, we examined 3,145 children ages 8–17 years (88% of the eligible geographic population; 65% white and 35% black) for serum lipids and lipoproteins, anthropometry, and other risk factors, administered a smoking questionnaire (including questions on oral contraceptives for older girls), and validated the smoking history with plasma thiocyanate levels. For the 78% of examined children with complete data, the coefficient of partial correlation between smoking and fasting serum α-lipoprotein (controlling for age) was significantly negative only in white girls ( P P P P P P P
Using the Optical Probe Methyl Orange To Determine the Role of Surfactant and Alcohol Chain Length in the Association of 1-Alkanols with Alkyltrimethylammonium Bromide Micelles

We have used the optical probe methyl orange to characterize the interaction of primary alcohol additives with micelles assembled from a series of alkyltrimethylammonium bromide (CnTAB) surfactants...
Molecular characterization of the vir regulon of Agrobacterium tumefaciens: complete nucleotide sequence and gene organization of the 28.63-kbp regulon cloned as a single unit.

Abstract The entire vir regulon of Agrobacterium tumefaciens was subcloned and the complete 28.6-kbp nucleotide sequence was determined. The regulon was cloned as a single unit into two replicons, one of which replicates at a high copy number in this bacterium, and a second which has broad-host-range features to replicate in other Gram-negative bacteria. These vir region plasmids are able to confer in trans the processing and transfer activities on a second plasmid containing the T-DNA. In the high copy number vir region plasmid pUCD2614, a moderate increase in basal vir gene expression was observed as judged by virE::cat fusion expression assays relative to the wild-type control plasmid. Furthermore, higher efficiencies of tobacco leaf disk transformation were observed than with the widely used vir helper plasmid pAL4404. The nucleotide sequence studies showed that the vir region consists of 28,631 bp comprising 24 open reading frames which encode proteins involved in tumorigenicity. Two open reading frames not previously characterized, virH and ORF5, were uncovered within the virD virE intervening spacer region. Together these studies more completely characterize the structure and function of the vir regulon.
An updated pest risk assessment for spread of Erwinia amylovora and fire blight via commercial apple fruit

The phytosanitary risk associated with the movement of export-quality apple fruit to countries where fire blight does not occur is reassessed based upon additional data available since 1998 and clarification or correction of previously misinterpreted data present in the literature. The low epiphytic fitness of Erwinia amylovora (Ea) on apple fruit, the documented low incidence of viable Ea populations on mature apple fruit and the lack of a documented pathway by which susceptible host material could become infected from fruit-borne inoculum remain unchanged, and support the view that movement of Ea via commercial apple fruit is highly unlikely. With this new information, we updated a previously published model to re-estimate the likelihood of fire blight outbreaks in new areas because of commercial fruit shipment. This likelihood decreased in every scenario, and ranged from one outbreak in 5217 years to one in 753,144 years. By using the corrected and newly published data and by making assumptions based upon documented pathogen biology, the model gives more robust statistical support to the opinion that the risk of importing Ea on commercial apple fruit and the concomitant risk of establishing new outbreaks of fire blight is so small as to be insignificant.
Measurement of group velocity dispersion of solvents using 2-cycle femtosecond pulses: Experiment and theory

Second and third-order dispersion for water, methanol, cyclohexane, carbon tetrachloride, dimethyl sulfoxide, toluene and carbon disulfide are measured with high accuracy and precision in the range of 700-900 nm using two-cycle long femtosecond laser pulses. The ratio between second and third-order dispersion, which is predicted to vary linearly, is experimentally confirmed and this observation is examined theoretically. A method to predict second and third-order dispersion of unknown transparent media with accuracy that is comparable to the best experimental methods is proposed and tested. The information provided is important for applications of ultrafast lasers in science, medicine and industry.
Cost-effectiveness of elective induction of labor at 41 weeks in nulliparous women.

Objective To investigate the cost-effectiveness of elective induction of labor at 41 weeks in nulliparous women. Study Design A decision analytic model comparing induction of labor at 41 weeks vs expectant management with antenatal testing until 42 weeks in nulliparas was designed. Baseline assumptions were derived from the literature as well as from analysis of the National Birth Cohort dataset and included an intrauterine fetal demise rate of 0.12% in the 41st week and a cesarean rate of 27% in women induced at 41 weeks. One-way and multiway sensitivity analyses were conducted to examine the robustness of the findings. Results Compared with expectant management, induction of labor is cost-effective with an incremental cost of $10,945 per quality-adjusted life year gained. Induction of labor at 41 weeks also resulted in a lower rate of adverse obstetric outcomes, including neonatal demise, shoulder dystocia, meconium aspiration syndrome, and severe perineal lacerations. Conclusion Elective induction of labor at 41 weeks is cost-effective and improves outcomes.
Deformation Spaces Associated to Compact Hyperbolic Manifolds

In this paper we take a first step toward understanding representations of cocompact lattices in SO(n,1) into arbitrary Lie groups by studying the deformations of rational representations — see Proposition 5.1 for a rather general existence result. This proposition has a number of algebraic applications. For example, we remark that such deformations show that the Margulis Super-Rigidity Theorem, see [30], cannot be extended to the rank 1 case. We remark also that if Γ ⊂ SO(n,1) is one of the standard arithmetic examples described in Section 7 then Γ has a faithful representation ρ′ in SO(n+1), the Galois conjugate of the uniformization representation, and Proposition 5.1 may be used to deform the direct sum of ρ′ and the trivial representation in SO(n+2) thereby constructing non-trivial families of irreducible orthogonal representations of Γ. However, most of this paper is devoted to studying certain spaces of representations which are of interest in differential geometry in a sense which we now explain.
ABORTION, AUTONOMY, AND CONTROL OVER ONE'S BODY

It is often thought that if a developing human being is considered a “person” from the beginning, then it would follow that abortion (at any time) would be impermissible. For, after all, a person has a stringent right to life, and because life is a prerequisite for enjoying any other goods, it is plausible that the right to life is a “basic” or “fundamental” one, not easily overridden by other considerations. The right to life, it would seem, could not be outweighed by another individual's preferences, even preferences about what should happen in or to her body.
Quaternary chronostratigraphy and stable isotope paleoecology of Big Bone Lick, Kentucky, USA

Abstract Big Bone Lick (BBL) in northern Kentucky, USA has been a critical geologic site in the historical development of North American Quaternary vertebrate paleontology since the 1700s. Sedimentology, geoarcheology, paleontology, accelerator mass spectrometry radiocarbon and optically stimulated luminescence dating, and stable carbon and nitrogen isotope analyses were undertaken to develop a chronostratigraphy and history of erosion and deposition for the site to provide a foundation for understanding taphonomy, and species extinction and adaptation to periods of climatic and environmental change. Three geomorphic surfaces are recognized at BBL representing significant periods of floodplain aggradation since the last glacial maximum (26.5–19 ka) dating to the Oldest Dryas (Tazewell, 25–19 ka), the Older Dryas (Cary, 14–12 ka), and late Holocene (5 ka to the present). Unconformities suggest significant periods of degradation during the transitions from cold and dry to warm and moist climates from the Oldest Dryas (Tazewell) to Bolling Oscillation, from the Older Dryas (Cary) to the Allerod, and from the Younger Dryas (Valders) to the Holocene Climatic Optimum. Increased anthropogenic activities since ~ 5 ka may have increased soil upland erosion and floodplain aggradation. Stable isotopes demonstrate that the landscape has been dominated by C3 vegetation since the last glacial maximum.
Detection of congenital heart disease in the first trimester of pregnancy

Abstract In this chapter we review the current status of early detection of congenital heart disease in the first trimester of pregnancy. There is an increasing demand for earlier diagnosis of congenital heart disease. Early fetal echocardiography is feasible and there are a number of complex diagnoses that can be made in early pregnancy. At present a follow-up second trimester ultrasound is required in all cases of on-going pregnancies. Early fetal echocardiography should be considered for fetuses at risk. For fetuses with an increased NT measurement, early fetal echocardiography should be reserved for those with a normal karyotype. Routine screening for structural heart disease should continue to be performed in the second trimester. Programs specializing in the early diagnosis of congenital heart disease should be confined to a small number of highly specialized institutions.
IMPAIRMENT OF NASAL Na + TRANSPORT IN VERY PRETERM INFANTS WITH RESPIRATORY DISTRESS SYNDROME (RDS). • 1982

IMPAIRMENT OF NASAL Na + TRANSPORT IN VERY PRETERM INFANTS WITH RESPIRATORY DISTRESS SYNDROME (RDS). • 1982
Research or Rhetoric? A Response to Wilcox and Nock

In their essay "'Her' Marriage after the Revolutions," Wilcox and Nock reprise their recent Social Forces article where they drew several unsubstantiated conclusions about predictors of wives' marital happiness (Wilcox and Nock, 2006). These skewed conclusions paved the way for media commentators to spin Wilcox and Nock's research into exaggerated headlines such as "The Return of the Happy Housewife" and "Desperate Feminist Wives" (O'Rourke, 2006; Tierney, 2006). Focusing on Wilcox and Nock's research?rather than their rhetoric?paints a much different picture.
Direct-transition analysis of new photoemission data for palladium

Abstract The Gilat-Raubenheimer integration procedure has been generalized to the calculation of photoemission energy distributions arising from direct interband transitions. A detailed application to Pd successfully explains the main features of new photoemission data ( d -band structure at 0.15, 1.2, 2.2 and 3.5 eV below the Fermi level), thus suggesting that nondirect transitions need not be invoked.
DOCKing ligands into receptors: The test case of α-chymotrypsin

Abstract Structures of 103 ligands previously tested as inhibitors of chymotrypsin catalysis were docked into the active site of the enzyme by use of the dock computer program. The goodness of fit was evaluated according to an approximate Lennard-Jones potential scoring routine. A statistical analysis indicated that dock correctly ranked the database when viewed in terms of a contingency table of four categories: true positives, false positives, true negatives, and false negatives. Eight of the top ten scoring molecules in the computerized docking procedure had been previously reported to be effective competitive inhibitors of chymotrypsin. This agreement between the computer predictions and experimental observations was encouraging and suggests that the dock computer program may be useful in evaluating other receptors for potential binding ligands.
Gene transfer to the intestinal tract: a new approach using selective injection of the superior mesenteric artery.

ABSTRACT Gene transfer to the intestinal tract has many potential applications, including complementation of single gene disorders, genetic immunization, and ectopic production of therapeutic molecules. Because the intralumenal approach to vector administration has not been highly successful, we tested whether the circulation can be used as a route to transfer genes to intestinal cells. The superior mesenteric artery (SMA) and vein (SMV) of adult Lewis rats were isolated and an adenoviral vector expressing the Escherichia coli LacZ gene was injected into the SMA. In one set of experiments, both vessels remained patent throughout the entire procedure. In a second group of animals, both vessels were occluded by clamping the SMA 1 cm distal to the injection site and the SMV proximal to the portal vein. In the absence of vascular clamps, gene transfer was evident throughout the small bowel, localized near the serosal surface within the muscularis propria. Occlusion of the SMA and SMV limited gene delivery to ...
Enabling Self-Management by Using Model-Based Design Space Exploration

Reconfiguration and self-management are important properties for systems that operate in hazardous and uncontrolled environments, such as inter-planetary space. These systems need a reconfiguration mechanism that provides recovery from individual component failures as well as the ability to dynamically adapt to evolving mission goals. One way to provide this functionality is to define a model of alternative system configurations and allow the system to choose the current configuration based on its current state, including environmental parameters and goals. The primary difficulties with this approach are (1) the state space of configurations can grow very large, which can make explicit enumeration infeasible, and (2) the component failures and evolving system goals must be somehow encoded in the system configuration model. This paper describes an online reconfiguration method based on model-based design-space exploration. We symbolically encode the set of valid system configurations and assert the current system state and goals as symbolic constraints. Our initial work indicates that this method scales and is capable of providing effective online dynamic reconfiguration.
Effect of Simultaneous Violations of Essential /g=t/-Equivalence and Uncorrelated Error on Coefficient /g=a/

Coefficient a, an estimate of the classical reliability coefficient, was evaluated under violations of two classical test theory assumptions: essential r-equivalence and uncorrelated errors. The interactive effects of both violations were explored using computer simulated true and error scores with known properties. As correlations among true scores decreased from 1, or essential -r-equivalence was systematically violated, a progressively underestimated the classical reliability coefficient. Simultaneously, as error score correlations increased from 0, the underestimation was attenuated and a became an inflated overestimate of the classical reliability coefficient. Although it is generally accepted that true score assumptions can be tested using confirmatory factor analysis (CFA), the research literature indicates that it is impossible, or at least extremely difficult, to empirically assess uncorrelated error with cross-sectional (as compared to longitudinal) data. Nevertheless, it is shown here that CFA ...
Candida albicans morphogenesis is influenced by estrogen.

Conversion of Candida albicans from yeast to mycelial growth is believed to be associated with the organism's virulence. We investigated the role of mammalian hormones in initiating this transformation. Three clinical isolates of Candida albicans were tested for their ability to produce germ tubes under various conditions. Controlled hormonal conditions were provided by stripping rabbit serum with activated charcoal. Steroid compounds under investigation were added back to the stripped serum and yeast were inoculated into the test materials. Microscopic counts of germinated versus ungerminated cells were used as an indicator of morphogenic transformation. The percent of yeast cells germinating was profoundly reduced in stripped compared to unstripped serum. The addition of 1 μM estradiol, cholesterol or testosterone only slightly increased levels of germination above that seen in controls. Estradiol at concentrations 100 times less, however, proved a strong inducer of germination. Cholesterol did not synergize germination when combined with estradiol and the alpha isomer of estradiol had almost no activity as an inducer of morphogenic change in Candida albicans. We conclude that beta estradiol was a morphogenic inducer in three clinical isolates of Candida albicans but only at concentrations typical in vivo.
Elevated Temperature n + -p Hg 0.8 Cd 0.2 Te Photodiodes For Moderate Bandwidth Infrared Heterodyne Applications

This paper presents the results of the first CO2 laser heterodyne measurements performed on boron implanted n+-p Hg0.8Cd0.2Te photodiodes. The measured data shows that this type of device structure is capable, of achieving bandwidths -20 of approximately 475 to 725 MHz and noise equivalent powers of 3.2 x 10-20 at 77 K and 1.0 x 10-19 W/Hz at 145 K.© (1980) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Choline oxidase and endogenous respiration in liver homogenates from x-irradiated rats.

Abstract Whole body x-irradiation of male adult rats caused a marked increase in the endogenous respiration of liver homogenized in 0.039 M sodium and potassium phosphate buffer, apparently with a lowered measurable liver choline oxidase activity. These effects are evident 6 hr. after exposure to x-rays, with x-ray dosages as low as 200 r. measured in air. These phenomena are reversible with sublethal doses and irreversible with lethal amounts of radiation. At 6 hr. following exposure to 400 r. or more of x-rays, the in vitro breakdown of the choline oxidase activity is less than in homogenates from control rats. Choline oxidase, but not endogenous oxygen uptake, of rat kidney apparently is increased in activity 18 hr. after rats are exposed to 800 r., and is decreased after 72 hr. following exposure. The implications of these findings are discussed.
Gonadal dysfunction in morbidly obese adolescent girls.

Objective To describe gonadal dysfunction and evaluate polycystic ovary syndrome (PCOS) and its association with metabolic syndrome (MeS) among girls in a morbidly obese adolescent population. Design In a cross-sectional study of 174 girls, height, weight, waist circumference, Tanner stage, reproductive hormones, carbohydrate and lipid markers, drug use, and menstrual history were obtained at baseline. Exclusion criteria were menarcheal age Setting University medical center outpatient clinic. Patient(s) Ninety-eight girls ages 13–19.6 years, Tanner 5, average body mass index of 46.6 kg/m2, menarche at 11.4 years, and average menarcheal age of 5 years. Intervention(s) None. Main Outcome Measure(s) Polycystic ovary syndrome and MeS. Result(s) Ninety-eight girls were divided into four groups: PCOS by National Institutes of Health criteria (PCOSN, n = 24), irregular menses only (n = 25), elevated T (≥55 ng/dL) only (n = 6), and obese controls (n = 43). Metabolic syndrome by modified Cook criteria affected 32 girls or 33% overall: 6 of 24 PCOSN, 7 of 25 irregular menses only, 4 of 6 elevated T only, and 15 of 43 obese controls. Polycystic ovary syndrome by National Institutes of Health criteria and its individual components were not associated with MeS after adjusting for body mass index. Conclusion(s) Unlike obese adults, PCOSN and its individual components were not associated with MeS in the untreated morbidly obese adolescent population.
Persistent plus disease after laser in retinopathy of prematurity with tetralogy of Fallot.

PurposeWe present a patient with retinopathy of prematurity (ROP) who received panretinal photocoagulation (PRP), but in whom plus disease developed, likely secondary to a complicated cardiovascula...
A spatial representation system for mobile robots

A two dimensional spatial representation system is presented which makes efficient use of distance information for accomplishing common mobile robot tasks. Ways to use the representation for route planning, positioning, and execution monitoring are presented. The representation is very space efficient, and all the transformations to be performed on it are computationally tractable.
Engineering Information Assurance for Critical Infrastructures: The DITSCAP Automation Study

Recent advances in information technology have transformed the way in which mission-critical services get delivered and are evaluated today. These services are heavily and increasingly relying on an interdependent crossed network of critical information infrastructures, spanning from private to government sectors. In order to enable such infrastructures to efficiently mitigate risks, optimize their security posture and evaluate their information assurance (IA) practices, we identify the need for a structured and comprehensive methodology for IA-aware critical infrastructure protection. In this paper, we focus on the automation study of the Department of Defense Information Technology Security Certification and Accreditation Process (DITSCAP) that is a standard for certifying and accrediting the information networks that comprise of the Defense Information Infrastructure (DII). We attempt to generalize a course of actions in DITSCAP that motivate our design principles and modeling techniques, supported by their theoretical backgrounds and demonstrable prototype interfaces to establish their appropriateness.
Giardia lamblia infections in adult mice

An adult mouse-Giardia lamblia model was developed and used to study host-parasite interactions, including antigenic variation. The H7/1 clone of isolate GS infected mice consistently and produced infections in 14 mouse strains tested. Infection patterns were mouse strain and Giardia isolate dependent. Antigenic variation occurred in immunocompetent mice but not in mice with severe combined immunodeficiency.
Madam & Eve: The Politics of Race and Postcolonial Television in South Africa

The situation comedy Madam & Eve (2000-2005) debuted on e.tv, a free-to-air South African television channel, and emerged as one of the most popular local shows, even winning international recognit...
Macroscopic Approach to Biomass Transport

Bioheat transport principles can be used to find heat flux and temperature in biological systems and devices as a function of both position and time. If we are interested in spatial variations of heat flux or temperature in a system, then it is necessary to use a microscopic approach, as presented in Chaps. 10 and 11. However, in many situations spatial variations are not of interest. Instead, we might be interested in predicting the rate or the amount of energy that flows in or out of the system as a whole, or we might like to know how the total energy varies with time inside the system. In such cases, a macroscopic approach can be used to describe the accumulation of energy within the system or the flow of energy through a system. Take, for example, the flow of heat from a human arm through a layer of clothing. We found in Chap. 8 that the temperature in the layer varies with radial position in a nonlinear fashion. However, we are usually interested in the heat flux from the arm, not the temperature distribution in the clothing. To compute the heat flux we only need to know the thermal resistance of the clothing layer and the temperatures at the inside and outside surface. If an additional layer, with known thermal resistance, is added to the clothing ensemble, its effect on heat loss can be computed using a macroscopic approach.
In situ micro-spectroscopic investigation of lignin in poplar cell walls pretreated by maleic acid

In higher plant cells, lignin provides necessary physical support for plant growth and resistance to attack by microorganisms. For the same reason, lignin is considered to be a major impediment to the process of deconstructing biomass to simple sugars by hydrolytic enzymes. The in situ variation of lignin in plant cell walls is important for better understanding of the roles lignin play in biomass recalcitrance. A micro-spectroscopic approach combining stimulated Raman scattering microscopy and fluorescence lifetime imaging microscopy was employed to probe the physiochemical structure of lignin in poplar tracheid cell walls. Two forms of lignins were identified: loosely packed lignin, which had a long (4 ns) fluorescence lifetime and existed primarily in the secondary wall layers; and dense lignin, which had a short (0.5–1 ns) fluorescence lifetime and was present in all wall layers, including the cell corners, compound middle lamellae, and secondary wall. At low maleic acid concentration (0.025 and 0.05 M) pretreatment conditions, some of the dense lignin was modified to become more loosely packed. High acid concentration removed both dense and loosely packed lignins. These modified lignins reformed to make lignin–carbohydrate complex droplets containing either dense or loosely packed lignin (mostly from secondary walls) and were commonly observed on the cell wall surface. We have identified dense and loosely packed lignins in plant cell walls. During maleic acid pretreatment, both dense lignin droplets and loosely packed lignin droplets were formed. Maleic acid pretreatment more effectively removes loosely packed lignin in secondary walls which increases enzyme accessibility for digestion.
Surface selectivity in four-wave mixing: transient gratings as a theoretical and experimental example

A theoretical treatment of transient grating diffraction is derived for gratings that are spatially nonuniform in the direction perpendicular to the sample surface. This treatment is readily generalized to any four-wave mixing experiment. Both reflection and transmission geometries of diffraction are examined for the standard transient grating case, in which both grating excitation beams are incident upon the same side of the sample For samples in which the grating amplitude perpendicular to the sample surface varies slowly relative to the optical wavelength, the reflection geometry is shown to probe only the surface or the interface, while the transmission geometry probes the bulk of the sample. An experimental example using four transient grating geometries (two reflection, two transmission) is shown to yield significantly different temporal responses, illustrating the nature of the theoretical predictions. The sample is a thin molecular crystal upon a substrate Both electronic excitations (excitons) and wave-guided acoustic modes are generated and probed Distinct signals are obtained from the bulk, the crystal–substrate interface, and the free-crystal face. Model calculations are presented that illuminate the behavior of the experimental example.
Nutritive Value of Sorghum Silage as Influenced by Grain Content

Abstract Sterile hybrid sorghum silage, with and without rolled sorghum grain added at feeding, and two silages, with whole and rolled sorghum grain ensiled with the sterile forage, were compared in a growth trial with 200-kg Hereford steers, a digestion trial with 200-kg dairy steers, and a lactation trial with Holstein cows. Silage dry matter consumption was least with seedless silage and almost identical for the drier, grain-containing silages and the seedless silage-sorghum grain combination. Steers gained most on rations containing rolled grain, intermediate on silage containing whole grain, and least on the grainless silage. Milk production was greater when the grain was rolled, either ensiled or fed with the seedless silage, than for the rations containing seedless silage and silage containing whole grain which resulted in equal milk production. Calculated digestible energy for lactation was greater for the seedless and rolled grain silages than for either the whole grain silage or the mixture of seedless silage and rolled grain. Steers used the whole grain-containing silage least efficiently but used all treatments more efficiently than did lactating cows. Poor animal performance with the grainless silage was associated with poor intake related to low dry matter content rather than to low digestible energy.