cssi/SciSciGPT-SciSciNet huggingface dataset:
Pseudomonas capsici sp. nov., a plant-pathogenic bacterium isolated from pepper leaf in Georgia, USA.

Three phytopathogenic bacterial strains (Pc19-1T, Pc19-2 and Pc19-3) were isolated from seedlings displaying water-soaked, dark brown-to-black, necrotic lesions on pepper (Capsicum annuum) leaves in Georgia, USA. Upon isolation on King's medium B, light cream-coloured colonies were observed and a diffusible fluorescent pigment was visible under ultraviolet light. Analysis of their 16S rRNA gene sequences showed that they belonged to the genus Pseudomonas, with the highest similarity to Pseudomonas cichorii ATCC 10857T (99.7 %). The fatty acid analysis revealed that the majority of the fatty acids were summed feature 3 (C16 : 1 ω7c/C16 : 1 ω6c), C16 : 0 and summed feature 8 (C18 : 1 ω7c/C18 : 1 ω6c). Phylogenomic analyses based on whole genome sequences demonstrated that the pepper strains belonged to the Pseudomonas syringae complex with P. cichorii as their closest neighbour, and formed a separate monophyletic clade from other species. Between the pepper strains and P. cichorii, the average nucleotide identity values were 91.3 %. Furthermore, the digital DNA-DNA hybridization values of the pepper strains when compared to their closest relatives, including P. cichorii, were 45.2 % or less. In addition, biochemical and physiological features were examined in this study and the results indicate that the pepper strains represent a novel Pseudomonas species. Therefore, we propose a new species Pseudomonas capsici sp. nov., with Pc19-1T (=CFBP 8884T=LMG 32209T) as the type strain. The DNA G+C content of the strain Pc19-1T is 58.4 mol%.
Characteristics and Space Distribution of Stars in the Bulge of the Milky Way

Stars in Baade’s Window at b = -4° are described. They are old, metal rich, and have a velocity dispersion greater than 100 km/sec. Their colors are unlike those of any other group of stars. Stars in other windows between b = -3 and -12° differ systematically from those in Baade’s Window. The differences are best understood if they are caused by a metallicity gradient in the bulge. The distribution of surface brightness or surface density over the bulge has a much steeper falloff than that seen in other galaxies or in the very center of the Milky Way itself. It is now possible to link together stars in the immediate vicinity of the nucleus with those that are several hundred parsecs out. Understanding this linkage will help in understanding the history and evolution of stars throughout the bulge and that part of the inner disk with which it overlaps.
Females without reflux symptoms or gastroesophageal reflux disease have less distal esophageal acid exposure than males without reflux symptoms or gastroesophageal reflux disease.

SUMMARY Ambulatory 24-hour esophageal pH monitoring is the gold standard examination to assess esophageal acid exposure. Gender-related variation is a well-recognized physiologic phenomenon in health and disease. To date, limited gender-specific 24-hour esophageal pH monitoring data are available. The aim of this study was to obtain values of esophageal pH monitoring in males and females without reflux symptoms or gastroesophageal reflux disease (GERD) to determine if gender variation exists in esophageal acid exposure among individuals without these factors. Twenty-four-hour dual esophageal pH monitoring was performed in male and female volunteers without reflux symptoms or GERD. Values for total number of reflux episodes, episodes longer than 5 minutes, total reflux time in minutes, % time with pH below 4, and longest reflux episode in the proximal/distal esophagus were obtained and recorded for both groups. The distal channel was placed 5 cm and proximal channel 15 cm above the manometrically determined lower esophageal sphincter. Means were compared using an independent sample t-test. Sixty-seven males and 69 females were enrolled. All subjects completed esophageal 24-hour pH monitoring without difficulty. There was no age or body mass difference between groups. Females had significantly fewer reflux episodes at both esophageal measuring sites and, significantly less total reflux time and % time with pH below 4 in the distal esophagus than males. All other parameters were similar. Significant gender-related differences exist in esophageal acid exposure, especially in the distal esophagus in individuals without reflux symptoms or GERD. These differences underscore the need for gender-specific reference values for 24-hour pH monitoring, allowing for an accurate evaluation of esophageal acid exposure in symptomatic patients.
On the persistence of rationing following liberalization: a theory for economies in transition

Abstract Many economic theorists and policy makers argue that a rapid liberalization in which prices are allowed to equilibrate supply and demand is critical for a successful transition in the formerly socialist economies. Yet, despite the advantages of market clearing prices, many local governments in these economies have kept their prices for basic goods low and induced rationing in the state sector. This paper develops a theory explaining why a local government chooses either a low state price that induces rationing or a higher price that clears the market. The theory predicts that a necessary condition for a local government representing its constituents' interests to set a market clearing price is that the private sector is monopolistic. While a market clearing price in the state sector curtails private monopoly power, it also implies that the state price is higher than in the rationing regime. It is shown that a local government's marginal benefit of restraining private monopoly power is higher than the marginal costs of higher state prices when there is an increase in either state sector costs or private capacity. This implies that a local government is more prone to set a market clearing price as its costs increase and as private capacity grows. Furthermore, when there are at least two private firms and the private sector is monopolistic, a local government that sets a market clearing price also stabilizes private sector pricing.
Scattering and color crosstalk in photorefractive correlation

ABSTRACT We present the of recording and reading color matched spatial filters in photorefractive LiNbO3 crystals. Detailed analysis and experimental results on the degrading effects encountered areprovided as well as techniques to reduce those effects. Topics discussed include color cross talk, crystal thickness effects, scattering, and wavelength selectivity. I. Introduction One of the strengths of optical signal processing is its ability to process information using multiple wavelengths in parallel so that large data sets can be processed at high speeds. Coherent optical sy stems capable of efficiently processing color signals in parallel are being developed. Concurrently,developments in photorefractive materials have lead to numerous applications of optical systems toreal-time image processing. Researchers have demonstrated storage capacities of thousands of holograms in volume photorefractive crystals such as LiNbO3". This large storage capacity makes the photorefractive crystal an implicit choice for recording multiple matched spatial filters (MSFts) ina pattern recognition sy stem. With suitable spatial light modulators and output detectors, a real-timecolor matched spatial filtering sy stem can be realized.
Single-Incision Laparoscopic Cholecystectomy: A Surgeon’s Initial Experience with 56 Consecutive Cases and a Review of the Literature

We describe the results of a single surgeon’s initial experience with single-incision laparoscopic cholecystectomy through his first 56 cases and provide a brief literature review on the development of this technique. Through a 2-cm vertical transumbilical incision, three 5-mm ports were placed using the Veress technique. One extracorporeal suture was utilized to provide cephalad retraction of the fundus, and a roticulating instrument grasping the infundibulum provided lateral retraction. The hilum was dissected, and the cystic duct and artery were clipped and divided. One 5-mm port was upgraded to a 10-mm port to allow the introduction of a retrieval bag, and the gallbladder was removed from the abdomen. Of 56 patients, 54 successfully underwent a single-incision laparoscopic cholecystectomy. Two patients required conversion to either a conventional laparoscopic cholecystectomy or open cholecystectomy. The average age was 41 years (18–77) and the average BMI, 30.2 kg/m2 (18.5–44.6). Mean operative time was 80 min (41–186). Length of stay was 0.3 days (0–2). The complication rate was 3/56 (5.4%). Our results suggest that single-incision laparoscopic cholecystectomy is a safe and effective alternative to four-port laparoscopic cholecystectomy that provides surgeons with an alternative minimally invasive surgical option and the ability to hide the surgical incision within the umbilicus.
On the total input of Antarctic waters to the deep ocean: A preliminary estimate from chlorofluorocarbon measurements

[1] Deep ocean inventories of dissolved chlorofluorocarbon-11 (CFC-11) along representative sections off Antarctica provide the first estimate of the overall strength of all dense water sources in the Southern Ocean. Their formation rates are reported for three density layers that span the main water masses involved in the lower limb of the Thermohaline Circulation (THC). The bottom layer is supplied via sinking of Antarctic Bottom Water (AABW) produced at a few continental shelves. The middle layer receives the offshore injection of ventilated Modified Circumpolar Deep Water (MCDW) produced along much of the lengthy Antarctic Slope Front. The top layer is ventilated by northward export of Antarctic Surface Water into the Upper Circumpolar Deep Water of the Antarctic Circumpolar Current. Average Southern Ocean inputs to the upper two layers of the deep ocean for the 1970-1990 period are derived on the basis of the CFC-11 distributions along meridional sections, the mean CFC-11 saturations of all water mass ingredients, and the inferred mixing leading to production of dense source waters. About 5.4 ± 1.7 Sv (1 Sv = 10 6 m 3 s -1 ) of near-freezing Shelf Water ventilate the bottom layer, and 4.7 ± 1.7 Sv and 3.6 ± 1.3 Sv of cold Antarctic Surface Water ventilate the middle and top layers. Therefore the total contribution of ventilated Southern Ocean waters to the lower limb of the global THC is about 14 Sv. This is close to the about 17 Sv estimated for North Atlantic near-surface sources from CFC-11 inventories. Their entrainment of 7.4 ± 2.4 Sv of CFC-poor subsurface Lower Circumpolar Deep Water during the formation and sinking of AABW and MCDW raises the total Southern Ocean input to the deep ocean to about 21 Sv.
The Temperature of Interstellar Iron Grains

In order for catalytic reactions to occur in interstellar dust clouds, it is necessary for the temperature of the grains to be about an order of magnitude hotter than usually calculated for grains of dielectric materials. However, transition metal (e.g., iron) grains should be fairly abundant, and because they absorb strongly in the visible and ultraviolet regions of the interstellar radiation field, they have equilibrium temperatures ∼ 133 K. This was determined by a new method which utilizes ‘Semi-Empirical’ free electron theory parameters in the infrared, coupled with a reiteration scheme which takes into consideration the change of conductivity of the iron with temperature.
The Political and Demographic Predictors of Candidate Emergence in City Council Elections

Legislative scholars have shown that candidates emerge when political conditions are most favorable. The topic of candidate emergence in city council elections is addressed using data collected on all 50 of Chicago’s wards from 1979 to 1995. The results show that wards with open seats or vulnerable incumbents on the ballot generally have a larger and more politically experienced crop of candidates than other wards. The findings also reveal that wards with higher concentrations of black residents have significantly larger and more politically experienced candidate pools than wards with fewer blacks. Explanations for these findings are discussed.
“They Arrested Me for Loving a Schoolgirl”: Ethnography, HIV, and A Feminist Assessment of the Age of Consent Law as a Gender-based Structural Intervention in Uganda

Abstract In 1990 women’s rights activists in Uganda successfully lobbied to amend the Defilement Law, raising the age of sexual consent for adolescent females from fourteen to eighteen years old and increasing the maximum sentence to death by hanging. The amendment can be considered a macro-level intervention designed to address the social and health inequalities affecting young women and girls, particularly their disproportionately high rate of HIV as compared to their male counterparts. While the intention of the law and aggressive campaign was to prosecute “sugar daddies” and “pedophiles,” the average age of men charged with defilement was twenty-one years old and many were believe to be “boyfriends” in consensual sexual liaisons with the alleged victims. This article uses court records, case studies, and longitudinal ethnographic data gathered in east-central Uganda to examine the impact of the age of consent law at national and local levels, and specifically what the disjunctures between national intentions and local uses reveal about conflicting views about sexual privilege and rights. I argue that existing class, gender, and age hierarchies have shaped how the Defilement Law has been applied locally, such that despite the stated aim of “protecting” young women, the law reinstates patriarchal privilege (especially against men of lower social class) while simultaneously increasing the regulation of adolescent female sexuality and undermining their autonomy. This paper demonstrates how ethnography and critical gender theory—which emphasizes the intersectionality of gender, age, and class in the (re)production of inequalities—can be used to examine consequences of macro-level interventions in ways that may be undetected in conventional public health evaluation techniques but that are crucial for designing and modifying effective interventions.
Pulmonary gangrene as a complication of mucormycosis

Pulmonary gangrene, a rare complication of pneumonia occurs when vascular thrombosis leads to necrosis of a large portion of lung. The devitalized lung is then sloughed into a cavity, resulting in a characteristic radiographic appearance. The previously reported cases of pulmonary gangrene have been associated with either bacterial or tuberculous pneumonia; the authors describe a case resulting from mucormycosis. In addition to the plain-film findings, the computed tomographic (CT) appearance is described.
Programming dynamically reconfigurable open systems with SALSA

Applications running on the Internet, or on limited-resource devices, need to be able to adapt to changes in their execution environment at run-time. Current languages and systems fall short of enabling developers to migrate and reconfigure application sub-components at program-execution time.In this paper, we describe essential aspects of the design and implementation of SALSA, an actor-based language for mobile and Internet computing. SALSA simplifies programming dynamically reconfigurable, open applications by providing universal names, active objects, and migration. Moreover, SALSA introduces three language mechanisms to help programmers coordinate asynchronous, mobile computations: token-passing continuations, join continuations and first-class continuations.We provide some examples which illustrate how SALSA programs are not only dynamically reconfigurable and open, but also much more concise and easier to follow than comparable Java code. Furthermore, we provide empirical results which show SALSA's performance to be better than Java code using an actor library, and which illustrate the difference between local, local area, and wide area communication and migration. Finally, we discuss the implementation of our preprocessor which translates SALSA code into Java.
Should I stay or should I go? A mixed methods study examining the factors influencing foster parents' decisions to continue or discontinue providing foster care

Abstract The recent economic recession has resulted in dramatic cuts to child welfare programs and services. Licensed foster homes represent an essential component of the child welfare system as these families provide for the care and safety of children during times when their own families are not able to do so. Despite the important role foster parents serve, little attention has been given to understand what impacts their decision about whether to continue fostering. This is especially important when considering the context of recent economic stressors on families and on the systems on which families rely. The purpose of this study was to understand what factors impact a parent's likelihood of continuing fostering. To accomplish this objective, a mixed methods concurrent triangulation design was conducted by sending an online survey to foster parents in one state located in the southwest. Findings based on this sample of 649 foster parents suggest foster families' intentions to continue fostering are positively impacted by their own intrinsic rewards and motivations, satisfaction with fostering, locus of control, and level of emotional and practical supports. Reduction in reimbursement rates, decreases in the amount of quality services available for foster children and for foster families, difficulty navigating the system, and individual-level family changes were cited as reasons foster parents would consider discontinuing fostering. Open-ended responses offer increased understanding about how these factors are perceived by respondents to impact their ability to continue to provide for our nation's most vulnerable children.
The effect of CGX-1007 and CI-1041, novel NMDA receptor antagonists, on NMDA receptor-mediated EPSCs

The N-methyl-D-aspartate (NMDA) receptor-gated ion channel is comprised of at least one NR1 subunit and any of four NR2 subunits (NR2A-D). The NR2 subunit confers different pharmacological and kinetic properties to the receptor. CGX-1007 (Conantokin G), a 17-amino acid polypeptide isolated from the venom of Conus geographus, is a novel NMDA receptor antagonist that is thought to be selective for the NR2B subunit. CGX-1007 has been reported to have highly potent, broad-spectrum anticonvulsant activity in animal seizure models. CI-1041 is an investigational compound, which also possesses anticonvulsant activity and has been shown to be highly selective for NR2B containing NMDA receptors. Although both CI-1041 and CGX-1007 are reportedly NR2B specific antagonists, they differ in their ability to block amygdala-kindled seizures, suggesting that the mechanism of action of these compounds differs. The present study was designed to test the hypothesis that CI-1041 and CGX-1007 would differentially modulate the function of NMDA receptors at excitatory synapses. Using the whole cell patch clamp technique, CGX-1007 and CI-1041 were found to block CA1 pyramidal cell, NMDA receptor-mediated excitatory postsynaptic currents (N-EPSCs) in a concentration-dependent manner in hippocampal slices from P4-P6 animals. In contrast, only CGX-1007 decreased NMDA receptor-mediated EPSC peak amplitude in slices from adult animals. The CGX-1007 block of peak amplitude was accompanied by a similar concentration-dependent decrease in decay kinetics of NMDA receptor-mediated EPSCs. These results suggest that while CI-1041 may be selective for NMDA receptors containing the NR2B subunit, CGX-1007 appears to be less selective than previously reported.
Examining the effects of fragmentation on genetic variation in Platanthera leucophaea (Orchidaceae): Inferences from allozyme and random amplified polymorphic DNA markers

Species that have become rare or endangered due to human disturbance are at increased risk of extinction as a result of environmental, demographic, and genetic stochasticity. Smaller populations, which can be typical of endangered species, are especially vulnerable to loss of variation through stochastic events. For 10 populations of Platanthera leucophaea (Nuttall) Lindley (Orchidaceae), a threatened species, genetic variation at allozyme and random amplified polymorphic DNA (RAPD) loci was measured to assess the potential effects of fragmentation and reduced population size on the future viability of populations. Allozymes revealed very low levels of diversity (AP = 1.18; PP = 12%; HO = 0.008) and high levels of population differentiation (FST = 0.75). Additionally, inbreeding coefficients were very high in five of the 10 populations surveyed, due largely to the fixation of alternative alleles at two loci in different populations. In contrast, every individual displayed a unique RAPD fingerprint, yielding higher levels of polymorphism (PP = 45%) and gene diversity (Nei's H = 0.159). Estimates of population differentiation based on RAPD are moderate as measured by amova (ΦST = 0.21), Wright's F-statistics (GST = 0.26), or Shannon's information index (Hamong = 0.30). However, genetic and geographic distances are not significantly correlated, suggesting a lack of interpopulation gene flow and/or genetic drift within populations. Population size is not a good predictor of genetic variation in the present study, and it is hypothesized that plant dormancy patterns and chaotic fluctuations in population size from year to year may buffer against stochastic events, especially in small populations.
Performance of pig heart after 30 or 120 minutes hypothermic arrest

The effect of the duration of hypothermic (T = 15°C) potassium cardioplegic arrest and ischemia on the heart was determined by measuring the response of the isolated in situ pig heart to 180 min of perfusion (n = 12) to provide appropriate control values for the study of 30 (n = 25) or 120 (n = 27) min of ischemia, followed by 60 min of reperfusion. In some of these animals, myocardial tissue samples were obtained for measurement of adenosine triphosphate (ATP) and creatine phosphate (CP), (6 in the perfusion group, 7 in the 30 min of ischemia and 60 min of reperfusion group and 15 in the 120 min of ischemia and 60 min of reperfusion group). In the remaining animals, measurements of either left ventricular performance (LVP), myocardial oxygen metabolism (MVO2) or plasma creatine kinase (CK) were obtained (6 in the prolonged perfusion group, 12 in the 120 min of ischemia and 60 min of reperfusion group, [6 LVP and MVO2 and 6 CK] and 18 in the 30 min of ischemia and 60 min of reperfusion group [13 LVP, 17 MVO2 and 6 CK]). During prolonged perfusion, left ventricular performance, expressed as developed pressure, ΔP, fell from an initial value of 175 ± 36 to 128 ± 19 mm Hg at 30 min of perfusion, followed by a more gradual decline to a final value of 113 ± 8 mm Hg at 180 min of perfusion. These decreases were not significantly lower than the initial value. The percentage of myocardial extraction declined in a similar manner, but coronary blood flow was constant over this interval. The primary effect of 30 or 120 min of ischemia was to reduce left ventricular developed pressure, ΔP, during reperfusion to more than 70% of the corresponding value in the control group (these differences were statistically significant) which suggests that prolonging the period of ischemia did not cause further deterioration of cardiac performance. The plasma concentration of CK rose in the control group of hearts subjected to prolonged perfusion from an initial value of 35 ± 6 to a final value of 59 ± 8 IU/liter (P < 0.05). While plasma CK increased during reperfusion in both ischemia/ reperfusion groups, these values were not significantly higher from prearrest values. Thus hypothermic cardioplegic ischemia of this duration did not appear to result in tissue necrosis, but there was a significant reduction in left ventricular performance which was independent of the duration of ischemia between the limits of 30 and 120 min.
A general form for solvable linear time varying singular systems of differential equations

A canonical form is derived for all linear solvable systems $E(t)x'(t) + F(t)x(t) = f(t)$ with sufficiently smooth coefficients E, F Using this form it is shown that for all smooth enough solvable ...
Electron microscopic analysis of DNA replication in main band and satellite DNAs of Drosophila virilis.

DNA was isolated from pre-blastoderm embryos of Drosophila virilis and fractionated by CsCl centrifugation. Fractions containing main band or satellite DNAs were examined by electron microscopy for replicating structures. Replication of main band DNA proceeded from many sites on a chromosome. Two classes of presumptive replicating molecules with more than one site of replication were seen in main band DNA. The first class contained one or more clusters of small eyes (all eyes less than or equal to 900 bases in size), whereas the second class was comprised of molecules with eyes of larger sizes. Many cluster-to-cluster distances in molecules in the first class and many eye-to-eye distances in molecules in the second class were equal to about 4000 bases or multiples thereof. These data are consistent with the following model. Replication in main band DNA is initiated by activation of 2 to 12 closely spaced origins. These clusters of origins are spaced at regular intervals along the chromosome and eventually fuse to produce larger eyes which are also spaced in a regular manner. Regular spacing of initiation sites is true for at least short stretches of the chromosome. However, it is possible that these regularly spaced sites are themselves part of a larger pattern of chromosome organization. Like the replication of main band DNA, that of satellite DNA proceeded, at least in part, by a chromosomal fork mechanism. However, linear replicating molecules were about five times less common in satellite than in main band DNA. As in main band DNA, single-stranded regions at fork junctions were small in comparison to those described in prokaryotes. There was no evidence for either clustering of initiation sites or regular spacing of eyes in satellite DNA. Thus, the organization of initiation sites appeared different in the two classes of DNA. In addition to conventional linear replicating molecules, structures were seen in satellite DNA which could be involved in extrachromosomal replication of some satellite sequences. However, these structures could also be explained by breakage of replicating molecules followed by reassociation of single-stranded regions.
MOLECULAR CHANGES DURING THE PHOTOOXIDATION OF α‐CRYSTALLIN IN THE PRESENCE OF UROPORPHYRIN

Singlet oxygen reacts preferentially with three amino acids in proteins, His, Trp and Met. In order to study the specific molecular events that result from such oxidations, calf alpha-crystallin was photooxidized in the presence of uroporphyrin and the reactions were investigated by high performance liquid chromatography peptide mapping using a photodiode array detector followed by fast atom bombardment mass spectrometry (FAB-MS). From these studies, the following conclusions can be inferred: (1) Upon photooxidation residue Met-68 of the B chain is oxidized to Met sulfoxide, whereas residue Trp-60 remains intact. (2) Two of the 16 His residues in alpha-crystallin are photooxidized with an apparent pKa of ca 7.0 (3) FAB-MS analysis suggests that residue Lys-166 close to the C-terminal end of the A chain forms a cross-link with the His-7 residue close to the N-terminal end of the A chain. This may be either an inter- or intramolecular cross-link.
Characterization of an inhaled toluene drug discrimination in mice: Effect of exposure conditions and route of administration

The drug discrimination procedure in animals has been extensively utilized to model the abuse related, subjective effects of drugs in humans, but it has seldom been used to examine abused volatile inhalants like toluene. The present study sought to characterize the temporal aspects of toluene's discriminative stimulus as well assess toluene blood concentrations under identical exposure conditions. B6SJLF1/J mice were trained to discriminate 10 min of exposure to 6000 ppm inhaled toluene vapor from air. Toluene vapor concentration dependently substituted for the training exposure condition with longer exposures to equivalent concentrations producing greater substitution than shorter exposures. Toluene's discriminative stimulus effects dissipated completely by 60 min after the cessation of exposure. Injected liquid toluene dose-dependently substituted for toluene vapor as well as augmenting the discriminative stimulus effects of inhaled toluene. Toluene blood concentrations measured under several exposure conditions which produced full substitution were all nearly identical suggesting that the concentration of toluene in the animal tissues at the time of testing determined discriminative performance. These results indicate that the discriminative stimulus effects of inhaled toluene vapor are likely mediated by CNS effects rather than by its pronounced peripheral stimulus effects.
A new flap in the dog containing a vascularized rib graft--the latissimus dorsi myoosteocutaneous flap.

Abstract A new island flap is described in the dog which is based upon the subscapular vessels and contains latissimus dorsi muscle, overlying skin and a segment of posterior rib. The posterior rib graft is vascularized by perforating vessels which connect the overlying skin and muscle to the posterior intercostal vessels. The rib segment is supplied by the medullary branch off the posterior intercostal artery. This flap was elevated in 10 dogs. Adequate blood supply to the rib was indicated by the observation of blood flow in the posterior intercostal vessels, by bleeding from the medulla of the rib, by routine histologic examination of the rib, and by tetracycline binding to amorphous calcium phosphate. Similar perforating vessels between the latissimus dorsi muscle and the posterior intercostal vessels have been found in primates and humans. This flap may have clinical application when an island or free composite tissue transfer is needed to reconstruct a defect requiring skin, bone, and possibly muscle.
Crystal structures of the active site mutant (Arg‐243 → Ala) in the T and R allosteric states of pig kidney fructose‐1,6‐bisphosphatase expressed in escherichia coli

The active site of pig kidney fructose-1,6-bisphosphatase (EC 3.1.3.11) is shared between subunits, Arg-243 of one chain interacting with fructose-1,6-bisphosphate or fructose-2,6-bisphosphate in the active site of an adjacent chain. In this study, we present the X-ray structures of the mutant version of the enzyme with Arg-243 replaced by alanine, crystallized in both T and R allosteric states. Kinetic characteristics of the altered enzyme showed the magnesium binding and inhibition by AMP differed slightly; affinity for the substrate fructose-1,6-bisphosphate was reduced 10-fold and affinity for the inhibitor fructose-2,6-bisphosphate was reduced 1,000-fold (Giroux E, Williams MK, Kantrowitz ER, 1994, J Biol Chem 269:31404-31409). The X-ray structures show no major changes in the organization of the active site compared with wild-type enzyme, and the structures confirm predictions of molecular dynamics simulations involving Lys-269 and Lys-274. Comparison of two independent models of the T form structures have revealed small but significant changes in the conformation of the bound AMP molecules and small reorganization of the active site correlated with the presence of the inhibitor. The differences in kinetic properties of the mutant enzyme indicate the key importance of Arg-243 in the function of fructose-1,6-bisphosphatase. Calculations using the X-ray structures of the Arg-243-->Ala enzyme suggest that the role of Arg-243 in the wild-type enzyme is predominantly electrostatic in nature.
Direct effects of dobutamine on the coronary microcirculation: comparison with adenosine using myocardial contrast echocardiography

Abstract The direct effects of dobutamine on capillary blood volume (VOL) and blood flow velocity (VEL) are not known. We hypothesized that these would be more similar to that of adenosine because of its effects on the β 2 receptors on the coronary circulation. A total of 9 open-chest anesthetized dogs were studied after placement of 2 noncritical stenoses at rest and during separate intracoronary administrations of 5 μg/kg −1 /min −1 of adenosine and 2 μg/kg −1 /min −1 of dobutamine. VOL and VEL were measured using myocardial contrast echocardiography, wall thickening with 2-dimensional echocardiography, and myocardial blood flow (MBF) with radiolabeled microspheres. Dobutamine increased the rate-pressure product significantly, whereas adenosine had no effect on the rate-pressure product. In the normal myocardium, adenosine had no effect on VOL and increases in MBF were all a result of increases in VEL. Dobutamine also caused mostly an increase in VEL and only a 30% increase in VOL indicating modest capillary recruitment. In the bed with stenosis both drugs attenuated increase in MBF by the same amount, which was associated with an attenuation in the increase in VEL secondary to a 15% increase in capillary resistance because of capillary derecruitment. The MBF-wall thickening relation was described for both drugs by the same function: y=1 − exp(x) with wall thickening being significantly higher for dobutamine compared with adenosine for each level of MBF. We conclude that the increase in MBF in the normal myocardium with intracoronary dobutamine occurs mostly from an increase in VEL rather than from an increase in VOL. In the bed with a noncritical stenosis, the increases in MBF and VEL are similar for both drugs. Similar to intracoronary adenosine, intracoronary dobutamine also caused capillary derecruitment distal to a noncritical coronary stenosis.
Theoretical Studies of the Coordination and Stability of Divalent Cations in ZSM-5

The coordination of divalent metal cations to ZSM-5 has been investigated using gradient-corrected density functional theory (DFT). Coordination at both isolated charge-exchange sites and pairs of charge-exchange sites was considered for Co2+, Cu2+, Fe2+, Ni2+, Pd2+, Pt2+, Ru2+, Rh2+, and Zn2+. Thermodynamic calculations of the stability of M2+ to reduction to M0 and demetalation to form MOx particles were also carried out. The results indicate that Cu2+, Co2+, Fe2+, and Ni2+ are coordinated preferentially to five-membered rings containing two Al atoms, which are located on the walls of the sinusoidal channels, whereas Pd2+, Pt2+, Ru2+, Rh2+, and Zn2+ are coordinated preferentially to six-membered rings located on the walls of the sinusoidal channels. Examination of the stability of dimer cations of the form [M−O−M]2+ shows that such structures are not generally stable to hydrolysis, with the possible exception of [Cu−O−Cu]2+. The findings of these calculations are in good general agreement with experimen...
In-process angle measurement and control for flexible sheet metal manufacture

A new method of controlling springback in small-radius pressbrake bending operations has been developed. This method provides a more accurate bending process, necessary for the further development of precision, small-lot sheet metal assembly manufacture. The pursuit of this research has led to the development of an inexpensive, high-resolution, on-line angle sensor. In addition, a simplified analytic model of the bending process was developed to predict springback in terms of material and tooling geometry variables. Finally, a springback control system has been developed with demonstrated accuracy of one-third of a degree in right-angle bends for cold-rolled steel samples covering a range of material properties.
Adaptive 2D Holographic Associative Processor

Design considerations for an optical holographic associative memory for implementation of fuzzy cognitive maps are presented. The holographic associations are implemented in a photorefractive material to provide adaptive connection strengths. The difference equation governing adaption is developed based on the physics of hologram formation in photorefractive materials. An architecture and operating system that accommodates the requirements of fuzzy cognitive maps while utilizing the capabilities of photorefractive holography are presented.
A fast approximation of homogeneous stochastic combat

The stochastic combat model with arbitrary interkilling time distribution is more general than the deterministic Lanchester model or the exponential model [3]. Unfortunately, the exact analytical solution of the more general combat model requires a huge amount of computation time, which makes it practically impossible to use for battles beyond 4 on 4. An approximate solution for a class of homogeneous stochastic combats with arbitrary interkilling time distribution is developed in this study. A large number of randomly generated battles from a very general population have been used to evaluate the approximation algorithm for accuracy and computation time. The results indicate that the approximation algorithm is highly accurate and its computation speed is about 100 to 1000 times faster than the corresponding simulation to reach the same level of accuracy
Singlet oxygen-induced inhibition of cardiac sarcolemmal Na+K(+)-ATPase.

Abstract We investigated the susceptibility of sarcolemmal Na + K + -ATPase to singlet oxygen. The role of this enzyme is regulation of Na + concentration and thereby membrane potential. Inhibition of Na + pump would lead to intracellular Ca 2+ overload therefore further aggrevating the injury caused by free radicals. Incubation of isolated sarcolemmal vesicles with irradiated rose bengal (150 n m ) resulted in 86 ± 1% inhibition of Na + K + -ATPase activity and histidine (25–100 m m ) protected the enzyme in a dose-dependent fashion whereas SOD, catalase or mannitol (·OH radical scavenger) did not have any effect. Also, the inhibition of Na + K + -ATPase activity was dependent on rose bengal concentration, intensity of irradiation, duration of light exposure, showing that inhibition was directly related to amount of singlet oxygen generated. These results show that singlet oxygen may have significant disruptive effects on sarcolemmal function and may represent an important mechanism by which the oxidative injury to the myocardium induces arrhythmogenesis.
Aging and endothelial barrier function in culture: Effects of chronic exposure to fatty acid hydroperoxides and vitamin E

As the endothelium ages it may become more susceptible to damage by atherogenic plasma components such as toxic lipid oxidation products. Vitamin E (vit E) might prove to be anti-atherogenic by reducing oxidative injury. This study investigated the effects of age and chronic exposure to fatty acid hydroperoxides (OFA) and/or vit E on endothelial barrier function (EBF) and cell growth characteristics. Chronic exposure to 5 microM OFA for 40 passages resulted in an age-related decrease in EBF, while supplementation of OFA-treated cultures with 25 microM vit E protected against the OFA-mediated decrease in EBF, independent of cell age. Vit E treatment alone had no significant effect on EBF relative to control cultures. No changes in growth characteristics, i.e., total DNA or protein per culture, were noted, regardless of treatment, although total DNA per culture decreased with increasing culture passage. These results suggest that chronic oxidative stress decreases EBF, predisposing the artery to infiltration by blood components and subsequent atherogenesis and that vit E delays cumulative changes in EBF related to chronic OFA exposure.
Network effects of frequency dependent phase response curves

Phase response curves (PRCs) are experimentally obtainable measures of the effects of small perturbations to a neuron on the timing of its firing. The PRC assumes that the neuron is repetitively firing at a constant frequency and that the perturbation is small relative to the period of the oscillation. Theoretical and simulation results have shown that neurons whose PRCs show a region of phase delay for early stimulus phases and a region of phase advance for late stimulus phases, called Type II PRCs, tend to synchronize more readily when synaptically coupled than neurons whose PRCs show only phase advances at all stimulus phases, called Type I PRCs. It has not been determined if PRC-induced properties of synchronization continue to hold in networks where the neurons are not intrinsically oscillatory, the synaptic coupling is not uniform, and neurons receive multiple inputs during each spike cycle. To investigate the influence of the neuronal PRC on network dynamics, we consider the effects upon synchronization of changes in the amplitude of the PRC that occur with changes in intrinsic firing frequency of neurons in large, noisy, non-uniform networks. We show that as the average network firing frequency increases, networks consisting of neurons with Type I PRCs show an increase in synchronization over large ranges of synaptic connectivity parameters. This is expected, as an increase in average synaptic current leads to greater effective coupling among neurons. In contrast, networks of neurons with Type II PRCs show a decrease in synchronization as frequency increases, implicating the influence of frequency-dependent changes in the PRC upon network synchronization.
Unilateral vocal fold paralysis in premature infants after ligation of patent ductus arteriosus: vascular clip versus suture ligature.

Objectives:We investigated risk factors associated with unilateral iatrogenic vocal fold paralysis (IVFP) in the context of ligation of patent ductus arteriosus (PDA) and compared the rates of paralysis between vascular clip and suture ligation procedures.Methods:We performed a prospective examination of infants with isolated PDA treated surgically during 1995 to 2005. Statistical significance was determined with a 2-tailed t-test.Results:Of 68 PDA ligations, 13 cases of left-sided IVFP were diagnosed, for an overall incidence of 19%. All cases of IVFP occurred in 55 infants who weighed less than 1 kg at birth. Suture ligature was used in 60% of all PDA ligation patients, and vascular clips in 40%. The incidence of IVFP in patients with vascular clips (19%) was similar to the incidence in those with suture ligature (20%). Hoarseness or stridor was present in 69% of patients with IVFP, compared to 17% of normal controls (p < 0.001). The rate of aspiration was not increased in the IVFP group; however, 15% o...
Optimal fully adaptive minimal wormhole routing for meshes

Abstract A deadlock-free fully adaptive minimal routing algorithm for meshes that is optimal in the number of virtual channels required and in the number of restrictions placed on the use of these virtual channels is presented. It is also proved that, ignoring symmetry, this routing algorithm is the only fully adaptive routing algorithm with uniform routers that achieves both of these goals. This new algorithm requires only 4n-2 virtual channels for an n-dimensional mesh. In addition, if more than the minimum number of virtual channels is available, the routing algorithm can use these additional channels with the fewest possible number of restrictions. The proofs are first presented for the 2D mesh and then generalized to n-dimensional meshes.
Transformed by Disappointment.

Karen E. Hall shares how weathering her own personal storms has helped her to guide her students to the learning opportunities inherent in their challenges.
edn1 and hand2 Interact in Early Regulation of Pharyngeal Arch Outgrowth during Zebrafish Development

Endothelin-1 (Edn1) signaling provides a critical input to development of the embryonic pharygneal arches and their skeletal derivatives, particularly the articulating joints and the ventral skeleton including the lower jaw. Previous work in zebrafish has mostly focused on the role of Edn1 in dorsal-ventral (DV) patterning, but Edn1 signaling must also regulate tissue size, for with severe loss of the pathway the ventral skeleton is not only mispatterned, but is also prominently hypoplastic – reduced in size. Here we use mutational analyses to show that in the early pharyngeal arches, ventral-specific edn1-mediated proliferation of neural crest derived cells is required for DV expansion and outgrowth, and that this positive regulation is counterbalanced by a negative one exerted through a pivotal, ventrally expressed Edn1-target gene, hand2. We also describe a new morphogenetic cell movement in the ventral first arch, sweeping cells anterior in the arch to the region where the lower jaw forms. This movement is negatively regulated by hand2 in an apparently edn1-independent fashion. These findings point to complexity of regulation by edn1 and hand2 at the earliest stages of pharyngeal arch development, in which control of growth and morphogenesis can be genetically separated.
Ab initio molecular orbital study of 1-methylsilatrane and model compounds

Abstract Ab initio molecular orbital calculations (3-21G∗) have been employed to explore bonding in two structures of 1-methylsilatrane: a solid-state structure based upon crystallographic data and a “gas-phase structure” in which the N-Si dative.bond has been artificially lengthened by 0.28 A. Despite the significant change in N-Si bond strength, there is very little change in calculated Mulliken charges. The utility of the 3-21G∗ calculations for this system was verified through comparison with 3-21G∗, 6-31G∗, other calculational studies and experimental data for NH3·SiF4, NH3·SiF(OH)3 and a variety of amine-borane adducts.
Soil management effects on entomopathogenic fungi during the transition to organic agriculture in a feed grain rotation

Abstract The growing demand for organic products creates opportunities for farmers. Information on the consequences of management practices can help farmers transition to organic and take advantage of these prospects. We examined the interaction between soil disturbance and initial cover crop on naturally occurring entomopathogenic fungi (EPF) during the 3-year transition to organic production in a feed grain rotation in central Pennsylvania. Our experiment included four systems comprised of a factorial combination of two levels of primary tillage (full vs. reduced) and two types of initial cover crop (timothy/clover vs. rye/vetch). The cropping sequence consisted of an initial cover crop, followed by soybean, and finally, maize. The entire experiment was replicated in time, with the initiation lagged by 1 year. We detected four species of EPF (Metarhizium anisopliae , Beauveria bassiana , Isaria fumosorosea , and Isaria farinosa ) by bioassay of soil samples collected four times during each field season. The latter three species were detected infrequently; therefore, we focused statistical analysis on M. anisopliae . Detection of M. anisopliae varied across sampling date, year in crop sequence, and experimental start, with no consistent trend across the 3-year transition period. M. anisopliae was isolated more frequently in the systems initiated with timothy/clover cover crops and utilizing full tillage; however, we only observed a tillage effect in one temporal replicate. M. anisopliae detection was negatively associated with soil moisture, organic matter, and zinc, sulfur, and copper concentrations in the soil. This study helps to inform farmers about management effects on soil function, specifically conservation biological control.
General relativistic solitons

A general relativistic and nontopological soliton is constructed by coupling a nonlinear scalar field to the standard gravitational field. Our results replicate the basic features of the special relativistic case: namely, a singularity-free lump with a discrete spectrum of eigensolutions. The central singularities and horizon that appear in the black hole solitons of string theory are not present.