cssi/SciSciGPT-SciSciNet huggingface dataset:
Contribution of buried aspartic acid to the stability of the PDZ2 protein

Abstract Statistical analysis of protein structures shows that buried aspartic acid residues on average form 2.5 to 3 hydrogen bonds and/or 0.8 potential ionic interactions with other protein groups. To estimate the energetic contribution of such buried groups to the Gibbs free energy of proteins, we measured the effects of amino acid substitutions of D56 in a model protein PDZ2 on its stability. We used temperature-induced unfolding monitored by DSC and denaturant-induced unfolding monitored by the changes in fluorescence intensity. We find that all substitutions of D56 lead to protein unfolding, thus suggesting that this buried hydrogen bonded aspartic acid has a significant contribution to the stability. To quantify the changes in the Gibbs free energy, one of the variants, D56N was stabilized by addition of the protective osmolyte TMAO. Comparison of the stability of the D56N variant with the wild-type PDZ2 in the presence and absence of TMAO allowed us to estimate the contribution of D56 to the protein stability to be 18 kJ · mol−1. These findings are discussed in terms of contribution of buried ionizable groups to protein stability.
Does Virtual Colonoscopy Have a Major Role in Population-Based Screening?

In summary, technical advances in the performance of VC are occurring at a very rapid pace. These technical improvements will undoubtedly improve the polyp detection rate and reduce false-positive and false-negative examinations. The concept of VC is clearly attractive and the general public is enamored with everything that has an association with virtual reality. As other articles in this issue have revealed, there are many techniques in development to help stratify patients at risk for colon cancer. As we begin to focus our health care resources on those at highest risk, the less need there is for inexpensive, broadly based screening techniques. Clearly, those patients at high risk for having polyps are better served by colonoscopy because of its therapeutic potential. That being said, in the view of this author, if a virtual preparation can be achieved and the cost of VC can be kept relatively low, then this technique will become part of our mainstream clinical practice. If an immaculate colon preparation must be performed and if the costs reflect standard abdominal and pelvic CT rather than a special reduced cost for VC, then it is doubtful that there will be any significant impact from this technology
Filtration Artifacts Caused by Overloading Membrane Filters

The conventional practice of using 0.45 or 0.40 microm membranes to distinguish between the particulate and dissolved phases in natural waters neglects the importance of colloids. Many of the colloids in natural waters pass through 0.45 or 0.40 microm membranes, but a significant fraction at the upper end of the colloidal particle size range is retained. Membrane clogging during filtration decreases the effective pore size and can cause the retention of increasing amounts of colloids. This filtration artifact can cause serious errors in sampling and in assigning trace metals to various particle size classes. We evaluated the effect of membrane loading for two common membrane types (0.45 microm Millipore Durapore and 0.40 microm Nuclepore) on the retention of colloidal Fe, Al, Mn, and OM in three Connecticut rivers. In addition, we used a 1.0 microm Nuclepore membrane to estimate the amount of colloids in the 0.40-1.0 microm size fraction that are retained by membranes during conventional filtration. All samples were collected with clean techniques, and all filtrations were carried out in a class 100 clean room. A peristaltic pump, set at an initial flow rate of 120 mL/min, was used to pump samples through 47 mm diameter inline Teflon filter holders. Back pressure and flow rate were monitored during filtration, and both are good indicators for the onset of membrane clogging. The results show a consistent correlation between increasing back pressure and decreasing concentration of colloidal Fe and sometimes Al, Mn, and OM in the filtrate for all membrane types. Although the shape of the loading-retention curves varied dramatically by site and by membrane type, the essential relationship between back pressure, flow rate, and filtration artifacts during membrane clogging remained the same.
Hypoxic "second hit" in leukocytes from trauma patients: Modulation of the immune response by histone deacetylase inhibition.

Abstract Introduction: Histone deacetylase inhibitors (HDACI), can improve survival after lethal hemorrhagic shock, and modulate the inflammatory response after hemorrhage/lipopolysaccharide (LPS). The current experiments were designed to study the effects of HDACI after hemorrhage and severe hypoxia. Methods: Splenic leukocytes from trauma and non-trauma patients ( n = 4–5/group) were exposed to severe hypoxia with/without suberoylanilide hydroxamic acid (SAHA, 400 nM) for 8 h. Cytokines were measured by ELISA and RT-PCR, and hypoxia inducible factor (HIF)-1a and heme oxygenase (HO)-1 by Western blot. Results: After hemorrhage and hypoxia, SAHA increased IL-1b gene (4.7 ± 1.2-fold) and protein expression (2.1 ± 0.6-fold) in trauma splenic leukocytes. It also reduced IL-10 gene expression (0.6 ± 0.2-fold), but did not alter TNFa or IL-6 levels. This unexpected pro-inflammatory response may be due to a decrease in HIF-1a and HO-1 protein levels. Conclusions: In this model of severe hypoxia, treatment with SAHA increased the inflammatory response in trauma leukocytes, possibly through inhibition of the HIF-1/HO-1 pathway. Splenic leukocytes from non-trauma patients were variably affected by SAHA. Taken in context with the known anti-inflammatory properties of HDACI after hemorrhage/LPS, these findings suggest that the immune-modulating functions of HDACI are dependent on the type and severity of both the priming injury and subsequent insult.
Sigmatropic rearrangement of sulfur and nitrogen allylic ylides studied by ab initio methods

Abstract The rearrangement of sulfur and nitrogen ylides was studied by ab initio methods. For nitrogen allylic ylides two mechanisms for the rearrangement were considered. One mechanism includes the dissociation of the two ionic parts of the ylide, the allyl anion and the cation with a heteroatom; these are intimate ion pairs and recombine into a product. The other reaction mechanism involves concerted bond breaking and formation of a new bond. The study was performed by evaluating the bond orders of the reactant and the transition structures and the activation barriers. The concerted mechanism was preserved. The same theoretical approach was applied to the study of sulfur allylic ylides. The selectivity of the reaction was studied by considering bond orders and activation barriers. It was concluded that sulfur ylides are more reactive than nitrogen ylides, and that the endo stereochemistry of the transition structure is preferred.
Immune and nonimmune clinical correlates of chronic renal allograft rejection

ECENT improvements in immunosuppression have led to a dramatic increase in short- and long-term renal allograft survival. Unfortunately, the rate of graft loss in the late posttransplant period has remained virtually unchanged. With current, excellent, short-term survival rates, future improvements in graft survival will depend on reducing the rate of late graft failure. Most allograft failure after the first posttransplant year is attributable to either death with a functioning kidney or chronic rejection (CREJ). Histologically, CREJ is most often characterized by interstitial fibrosis, glomerular sclerosis, and a distinctive fihrointimal proliferation in intrarenal arteries. Although the pathogenesis of CREJ is unknown, it has been useful to hypothesize that both immune and nonimmune mechanisms may play a role in the vascular, glomcrular, and interstitial injury. Clinical correlates of CREJ can also he considered to he immune and nonimmune, although distinctions between the two arc often blurred. Among putative immune risk factors, major histocompatihility mismatches (MHC) appear to correlate with the rate of late graft failure. In a recent single-center study, we reported that DR mismatches correlated with graft loss to CREJ (85% confirmed by histology).’ However, when acute rejection (AREJ) episodes were taken into account in a multivariate model, the effect of DR mismatching was no longer statistically significant. Many studies have reported that AREJ is a risk factor for CREJ. We found, however, that not all AREJ leads to CREJ. In particular, AREJ episodes occurring within the first 3 months after transplantation were not an independent risk factor for CREJ in multivariate analysis.’ Whether immunosuppression per se influences CREJ has been controversial. The lack of evidence that cyclosporine (CsA) alters the rate of late graft failure has prompted us to systematically withdraw CsA in stable patients after the first posttransplant year.’ In our center, routine CsA withdrawal does not appear to adversely affect long-term allograft survival. Similarly, a meta-analysis of randomized controlled trials failed to demonstrate even a trend toward any affect on graft survival of elective CsA withdrawal.’ It seems
Toward Preventing Future Tragedies: Mass Killings on College Campuses, Public Health, and Threat/Risk Assessment

Prevention of psychological injuries is important in the broader area of psychological injuries and the law. One area that is particularly prominent in this respect involves the serious violence that has occurred on some college campuses recently. The safety of those on our campuses is important. In certain respects, colleges and universities (“colleges” will refer to both in this article) function as a haven from the pressures and expectations of the broader society, providing a setting in which youth can learn, mature, and prepare to assume adult roles. In other respects, they reflect some of the same financial and performance pressures that students will face in the personal and professional roles they assume upon graduating. But it remains essential that colleges provide a safe environment in which undergraduates mature intellectually and emotionally in pursuit of an undergraduate degree, and others train to receive advanced degrees. The functioning of a civilized society depends in part upon a continuing supply of educated citizens and professionals who train in colleges. Colleges have several characteristics that make them vulnerable to violence and crime. First, most campuses are not only open, but completely open. Anyone can enter the campus, without identification or a reason to be there. Second, since the student body is typically comprised almost exclusively of people in the age range that is associated with the highest levels of crime and violence (Bureau of Justice Statistics, http://www.ojp.usdoj.gov/bjs,
The membrane affinities of the aliphatic amino acid side chains in an alpha-helical context are independent of membrane immersion depth.

Understanding, predicting, and designing the binding of peptides and proteins to bilayers require quantifying the intrinsic propensities of individual amino acid residues to bind membranes as a function of structural context and bilayer depth. A host−guest study was performed using the peptide host named helix5 in order to determine the membrane affinities of the aliphatic side chains both in an α-helical context and as a function of bilayer depth. Use of the α-helical host with a constrained geometry allowed the placement of guest sites at three different depths in bilayers and minimized secondary structural changes due to guest substitutions. Circular dichroism and electron paramagnetic resonance (EPR) were used to characterize the aqueous and bilayer-bound structures of the peptide variants. EPR was also used to measure the bilayer−water partition constants of the peptide variants, and the ΔΔGtr values (relative to Gly) of the aliphatic amino acid side chains were subsequently calculated. Surprisingly,...
Pharmacokinetic interaction between intravenous phenytoin and amiodarone in healthy volunteers

To determine the mechanism of the amiodarone-phenytoin interaction, seven healthy male subjects were given intravenous phenytoin, 5 mg/kg, before (phase I) and after (phase II) 3 weeks of oral amiodarone, 200 mg/day. Serum AUC increased from 245 +/- 37.6 to 342 +/- 87.3 mg.hr/L (p = 0.007); area under the first moment curve increased from 5666 +/- 1003 to 11,632 +/- 4198 mg.hr2/L (p = 0.008); the time-averaged total body clearance decreased from 1.57 +/- 0.3 to 1.17 +/- 0.33 L/hr (p = 0.0004); and the apparent elimination half-life increased from 16.1 +/- 1.32 to 22.6 +/- 3.8 hours (p = 0.001) for phenytoin during phase II. The volume of distribution at steady state and the unbound fraction for phenytoin remained unchanged. However, the formation of p-hydroxyphenytoin as a function of serum phenytoin concentration decreased during phase II. These findings suggest that amiodarone inhibits phenytoin metabolism. These observations also suggest that phenytoin doses will need to be reduced when coadministered with amiodarone. The magnitude of this reduction is difficult to predict because of the saturable pharmacokinetics of phenytoin, and therapeutic monitoring is recommended if amiodarone is added to the phenytoin regimen.
The effects of interpersonal relationship and character gender on adolescents' resolutions of moral dilemmas

Abstract An experimental study using two forms of the Defining Issues Test [Rest, J. R. (1979). Revised manual for the Defining Issues Test. Minneapolis: Moral Research Project, University of Minnesota.], modified to present either a high degree of relationship among characters or a low degree of relationship among characters, was conducted with 114 college students. The gender of the characters in the dilemmas was also systematically varied. Both male and female students evidenced principled (Stages 5 and 6) reasoning more often when dilemma characters were male than when story characters were female. Participant gender and relationship condition were significant factors in the frequency of Stage 4 reasoning. Male students in the low-relationship condition evidenced Stage 4 (“Law and order”) reasoning most often when story characters were male, while male students, like female students in all conditions, showed Stage 4 reasoning more often when female characters were presented in the high-relationship condition. The degree to which moral decisions were supportive of an affected character revealed more support when story characters were female than when they were male. Results indicate that even in hypothetical situations, moral judgments vary with the gender of the person being judged and to some degree with the relationships among those involved in the dilemma. These findings are consistent with a view that multiple, equally valid approaches to moral judgment might exist and affect the development of male and female students differently.
Formation of a Dirhenium Carbene Complex from Reaction of (η5-C5H4Li)Re(CO)3 with (η5-C5H5)Re(CO)3

The ring-metalated complex (η5-C5H4Li)Re(CO)3 generated by reaction of (η5-C5H5)Re(CO)3 with n-BuLi in THF at −78 °C reacted with additional (η5-C5H5)Re(CO)3 to produce the dirhenium acyl anion (η5...
Irradiation of bacterial luciferase in vivo.

The fading of in vivo luminescence which is characteristically displayed by resting cell suspensions of the luminous bacteria Photobacterium fischeri is partly accounted for by a gradual loss of active luciferase. This luminescence is further diminished by exposure of such suspensions to gamma radiation, but the irradiated cells yield more, rather than less, active luciferase than do cells of the non-irradiated suspension. These and similar results with menadione-treated cells indicate that, while luciferase is gradually inactivated by its catalysis of light production, it can resist inactivation by radiation better than can some component of its supporting metabolism.
A Dual-Band Telemetry Transmitter for Broadcast Satellite Applications

The advent of domestic communications satellites that operate at C-band and Ku-band for the telemetry downlink has generated the requirement for a dual-band transmitter operating at three distinct frequencies and in four related modes of power output. The design and configuration of such a transmitter are discussed with consideration given to the application of GaAs FET devices to frequency multiplication and to power amplification within transmitter modules. The modular, lightweight design has been approached through a series of trade-offs that resulted in minimum power consumption during each mode of operation.
On the Contact Problem of an Inflated Spherical Nonlinear Membrane

The contact problem of an inflated spherical nonlinear elastic membrane between two large rigid plates is formulated in terms of three first-order ordinary differential equations for the region where the spherical membrane is not in contact with the rigid plates. The constraint condition introduced by the rigid plate on part of the spherical membrane reduces the number of governing equations to two for the contact region. A general stress-strain relation for the spherical membrane is used in the formulation. The results presented in this paper assume that the material behavior of the spherical membrane is that described by the Mooney model. Nonlinear spring characteristics and the instability phenomena of the inflated membrane are discussed.
The Value of Distillers Feeds for Milk Production

Summary In two experiments Holstein cows produced an average of 2.6lb. more 4 per cent fat-corrected milk daily on a concentrate mixture containing corn distillers dried grains with solubles and 1.6lb. more with corn distillers dried solubles than on a similar mixture containing corn gluten feed and soybean oil meal as the principal protein supplement to oats and barley. Rye distillers dried grains with solubles gave results approximately equal to corn gluten feed in a single study. Analyses of variance of the results of the two studies showed that the differences in production approached significance at the 5 per cent level. The authors believe the results suggest that corn gluten feed probably is not as efficient as a protein supplement to barley and oats for milk production as corn distillers dried grains.
Characterization of solution processed, p-doped films using hole-only devices and organic field-effect transistors

Abstract We report a solution processed, p-doped film consisting of the organic materials 4,4′,4″-tris(3-methylphenylphenylamino)triphenylamine (MTDATA) as the electron donor and 2-(3-(adamantan-1-yl)propyl)-3,5,6-trifluorotetracyanoquinodimethane (F3TCNQ-Adl) as the electron acceptor. UV–vis–NIR absorption spectra identified the presence of a charge transfer complex between the donor and acceptor in the doped films. Field-effect transistors were used to characterize charge transport properties of the films, yielding mobility values. Upon doping, mobility increased and then slightly decreased while carrier concentration increased by two orders of magnitude, which in tandem leads to conductivity increasing from 4 × 10 −10 S/cm when undoped to 2 × 10 −7 S/cm at 30 mol% F3TCNQ-Adl. The hole density was calculated based on mobility values extracted from OFET data and conductivity values extracted from bulk I – V data for the MTDATA: x mol% F3TCNQ-Sdl films. These films were then shown to function as the hole injection/hole transport layer in a phosphorescent blue OLED.
Subpicosecond all-optical modulation using the optical stark effect in a nonlinear directional coupler

All-optical modulation in a GaAs/AlGaAs multiple quantum well nonlinear directional coupler is observed at room temperature using femtosecond pulses. The ultrafast (< 1 ps) response and recovery of the device is attributed to the optical Stark effect. All-optical switching in various nonlinear optical devices is of interest because of its possible application in high-speed photonic switches. In semiconductor devices, which exploit the relatively large optical nonlinearities near a semiconductor bandedge, the source of the nonlinearity is typically the presence of free carriers photoexcited by a temporally short pump (i.e. control) beam. Previously we have demonstrated all-optical switching both in a GaAs/AlGaAs multiple quantum well (MQW) nonlinear etalon, as well as in a MQW nonlinear directional coupler (NLDC) using real carrier excitations to generate the nonlinearities. In both cases the device has a response which follows the pulse, and a recovery time which was limited to ≈10ns by the recombination and the diffusion of the photo-generated carriers. Recently, the operation of a nonlinear etalon with a subpicosecond recovery time was demonstrated. This was accomplished by using femtosecond pulses tuned in the semiconductor's transparency region to generate instantaneous nonlinearities which were present only while the pump travelled through the etalon. In this case the source of the optical nonlinearity was the now well known optical Stark effect. Here we report the first observation of ultrafast switching, including < 1ps recovery time, in a GaAs/AlGaAs NLDC. We believe the optically-induced temporally-short index change responsible for this fast switching is generated by the optical Stark effect.
Real-time performance of commercial Intel-based VME Controllers for the CODA data acquisition system

We have evaluated the performance of several Intel-based VME Controllers for the use in the data acquisition systems (DAQs) at Jefferson Lab. For the 12 GeV upgrade, PPC-based VME controllers running vxWorks will be replaced with those that are Intel-based running Linux. Their task will be facilitated by the use of FPGAs on the VME modules to perform trigger logic and communicating trigger information over serial and fiber connections through the DAQ. The need for a hard realtime operating system on the VME controller is removed from the equation as the readout of the digitized data from the VME modules (using VME-2eSST) is done in a threaded environment with multiple CPU cores while digitization takes place in the buffered, pipelined system. In this paper we briefly discuss a bench setup for evaluating a VME Controller and its kernel and user space environment. We present results from baseline testing of various models from different vendors using different Linux kernels, including results from a kernel compiled with the CONFIG_PREEMPT_RT patch.
Decreased Wound Contraction With Fibrin Glue—Treated Skin Grafts

• Skin grafts can be used effectively to inhibit wound contraction. A critical element of this inhibition is the adherence of the graft to the wound bed. Fibrin glue has been shown to increase the adherence of skin grafts to wound beds. We therefore devised an experiment to determine the effect of fibrin glue on skin graft inhibition of wound contraction. Two 2.5 × 2.5-cm full-thickness defects were created on the dorsa of 15 Sprague-Dawley rats. Thirty partial-thickness grafts were harvested from isogeneric donor animals using a brown dermatome. Prior to grafting, one full-thickness defect, each animal received 0.2 mL of fibrin glue (Immuno AG, Vienna, Austria). The adjacent wound served as the control and received 0.2 mL of normal saline. Grafts were applied, sutured, and protected with an occlusive dressing. The size of graft sites treated with fibrin glue or normal saline was determined at the time of graft application and thereafter at 3-day intervals for 21 days using standardized photographic techniques. The percentage of change from initial wound size at each point was recorded for each group. Graft sites treated with fibrin glue contracted less than the controls from the ninth postgraft day to the completion of the study. The mechanism by which fibrin glue inhibits wound contraction may be related to increased adherence of grafts to the underlying wound bed. As an adjunct in skin grafting, fibrin glue may offer certain advantages that are not achieved by suturing alone. ( Arch Surg . 1992;127:404-406)
Effects of attractive versus repulsive vibrotactile instructional cues during motion replication tasks

The Mobile Instrument for Motion Instruction and Correction (MIMIC) enables an expert (i.e., physical therapist) to map his/her movements to a trainee (i.e., patient) in a hands-free fashion. MIMIC comprises an Expert Module (EM) and a Trainee Module (TM); both modules include six-degree-of-freedom inertial measurement units, microcontrollers, and batteries. The TM also includes actuators that provide the trainee with vibrotactile instructional cues. The estimated expert body motion information is transmitted wirelessly to the trainee; based on the computed difference between the motions of the expert and trainee, directional instructions are displayed to the trainee's skin via vibrotactile stimulation. This study examined anterior-posterior trunk movements using a simplified version of the MIMIC system in which only two actuators were used to provide feedback and pre-recorded target trajectories were used to represent ideal expert movements. The study was designed to investigate the effects of attractive versus repulsive vibrotactile instructional cues when the motion speed and task complexity were varied. Preliminary results (n = 12) suggest that repulsive vibrotactile instructional cues lead to the greatest correlation between expert and subject motion, the least time delay, and the least tilt error.
China's New Urban-Rural Divide and Pitfalls for the Chinese Economy

ABSTRACT This paper examines the widening urban-rural income gap in China which has existed since 1985, and its implications for the Chinese economy. I argue that the declining fiscal capacity of the central government and the ensuing central-local competition for revenues, a systematic urban bias in Chinese financial mechanisms, and the structural vulnerability of small peasant farmers in a transitional economy have all contributed to the growing disparity between urban and rural residents. The consequences of this growing urban-rural gap have begun to haunt the Chinese economy as it struggles to readjust from export-oriented growth to the boost of domestic demand.
Cryoembedding and sectioning of cochleas for immunocytochemistry and in situ hybridization

Current emphasis on biochemical and molecular aspects of cochlear anatomy underscores the necessity for high quality cryostat sections of the inner ear. The large volume of fluid space within the cochlea makes cryoembedding and sectioning of the organ more problematic than that of other, more homogeneous tissues. Our method for cryoembedding of cochleas for immunocytochemistry and in situ hybridization uses slow infiltration with increasing concentrations of sucrose followed by degassed embedding medium before final orientation and freezing. This method permits high quality cryosections to be cut which preserve overall structure and cellular resolution.
A Technique for Cardioplegic Infusion and Left Heart Venting during Coronary Artery Bypass Grafting

A method for administering cardioplegia and venting the left heart that utilizes a single cannula in the aortic root and minimizes the risk of air entering the left heart is presented. This technique permits precise control of flow and pressure of the cardioplegic solution. Left heart decompression is accomplished by siphon drainage with controlled negative pressure. This method effectively vents the left heart while preventing aspiration of air around the cannula insertion site or retrograde through an opened coronary artery with a nonocclusive proximal lesion during the construction of the distal anastomoses.
Young children with disabilities: Functional assessment by teachers

A number of limitations have contributed to long-standing problems of inappropriate categorization of children and inadequately defined populations in special education practice and research. Diagnostic ambiguity and overlap of categories have served to complicate communication about individual children and the design of appropriate interventions. There is a need for functional approaches to document child characteristics which build on conceptual models of disability and yield consistent terminology. This study examines the usefulness of assessing children's functional abilities as an alternative to existing categorical classifications in special education. The ABILITIES Index, a functional measure encompassing the domains of audition, behavior/social skills, intellectual functioning, limbs, intentional communication, tonicity, integrity of health, eyes, and structural status was scored for 108 children with disabilities receiving intervention services in center-based public preschools. Profiles for children revealed substantial intra and inter-individual variability. Exploratory hierarchical cluster analysis yielded a six-factor solution of subgroups sharing similar ability/disability profiles. Results supported the potential utility of an approach focusing on the classification of child characteristics rather than classification of children. Further research is needed to examine the utility of the ABILITIES Index to complement other assessment data in order to personalize intervention plans.
A Paradigm Shift Was Happening All Around Us

Thankfully, Ridley Scott's brilliant Super Bowl ad, proclaiming that 1984 won't be like 1984, heralded a Golden Age of Electronics instead of George Orwell's dyspeptic scenario. Apple's Macintosh debuted, Hewlett-Packard and its new LaserJet printer set record sales and profits for Silicon Valley companies, and I met Lynn Conway when we both joined the IEEE Spectrum Advisory Board. Although Conway was a bit shy and had held back from the limelight, I already “knew” her. As HP's Corporate Engineering Director, my job was to “know” the Valley. Operating a prototype Macintosh six months prior to introduction, I'd sparked Tom Whitney's Summerhill Partners' angel round that was the initial funding for Aldus Corporation and Pagemaker. I'd compared views with Xerox PARC's Warren Teitleman, both a Caltech classmate and a neighbor (with an Alto and then a Dorado by his home swimming pool). Warren and I had both known Carver Mead for 25 years. Mead was my senior advisor, urging me to join HP in 1962. By 1975, Mead and Conway were collaborating at PARC.
Adverse cardiovascular events temporally associated with ma huang, an herbal source of ephedrine.

Objective To evaluate possible cardiovascular toxic effects associated with use of dietary supplements containing ma huang, an herbal source of ephedrine. • Methods : We reviewed the comprehensive database Adverse Reaction Monitoring System of the Food and Drug Administration, which included clinical records, investigative reports, and autopsy reports related to ma huang use. The main outcome measurements were stroke, myocardial infarction, and sudden death. Results From 1995 to 1997, 926 cases of possible ma huang toxicity were reported to the Food and Drug Administration. In 37 patients (23 women and 14 men with a mean ± SD age of 43±13 years), use of ma huang was temporally related to stroke (in 16), myocardial infarction (in 10), or sudden death (in 11). Autopsies performed in 7 of the 11 patients who experienced sudden death showed a normal heart in 1, coronary atherosclerosis in 3, and cardiomyopathies in 3. In 36 of the 37 patients, use of ma huang was reported to be within the manufacturers' dosing guidelines. Conclusions Analysis of the 37 patients indicates the following findings: (1) ma huang use is temporally related to stroke, myocardial infarction, and sudden death; (2) underlying heart or vascular disease is not a prerequisite for ma huang-related adverse events; and (3) the cardiovascular toxic effects associated with ma huang were not limited to massive doses. Although the pathogenesis of the cardiac toxic effects of ma huang remains incompletely defined, available observational and circumstantial evidence indicates that use of the substance may be associated with serious medical complications.
Evaluation of functions on microcomputers: rational approximation of kth roots

This paper describes the implementation of rational approximation algorithms for evaluation of kth roots in short wordlength machines. The emphasis is on maintaining full machine precision in computers that use fixed point, truncated binary arithmetic with at most 16 bits of wordlength. Included is a table of coefficients for evaluation of kth roots on a 16 bit machine with 3 ≤ k ≤ 11.
Biostratigraphy of Marine Triassic in Northern Alaska: ABSTRACT

Marine Triassic sedimentary rocks crop out in northern Alaska at scattered localities in a belt that extends from Cape Thompson and the DeLong Mountains on the west, eastward along the north front of the Brooks Range across the drainages of the Colville and Sagavanirktok rivers, and then northeastward to the Shublik and Romanzof Mountains of northeasternmost Alaska. Respective parts of this outcrop belt are designated as western (W), central (C), or eastern (E). Although highly condensed, especially on the west, the Triassic is nearly completely represented. From study of the U.S. Geological Survey collections, distinctive successive ammonoid and pectenacid bivalve faunas, with their ages and stratigraphic occurrences, are: (1) Otoceras of early Griesbachian and Ophiceras and Claraia stachei of late Griesbachian age, lower Ivishak Member of Sadlerochit formation (E); (2) Euflemingites romunderi fauna of early Smithian age, upper Ivishak Member of Sadlerochit formation (E) and "shale member of Shublik formation" (C); (3) Leiophyllites fauna of probable early Anisian age, "shale member of Shublik" (C and W?); (4) Daonella frami and/or D. degeeri of early Ladinian age, lower Shublik formation (E) and lower "chert member of Shublik" (C and W); (5) Leptochondria nationalis fauna of probably early Karnian age, middle of Shublik formation (E), correlative in part with Halobia cf. H. zitteli occurrences in "chert member of Shublik" (C and W); (6) Arctosirenites canadensis fauna of late Karnian age, middle of Shublik formation (E), correlative in part with Halobia cf. H. ornatissima occurrences in "chert member of Shublik" (C and W); (7) Monotis typica of early (?) and early middle Norian age, "Shublik formation" (W); (8) Monotis pinensis, M. obtusicostata, and/or Halobia fallax of middle Norian age, upper Shublik formation (E) and "limestone member of Shublik" (C and W); (9) Monotis ochotica ochotica and/or M. subcircularis of late Norian age, upper Shublik formation (E) and "limestone member of Shublik" (C and W); and (10) Monotis ochotica pachypleura of late Norian or younger Triassic age, uppermost "Shublik formation" (C and W). These faunas have much in common with those from along the Yukon River in east-central Alaska and from the Canadian Arctic Archipelago and eastern Asia, but they contrast strongly with Triassic faunas of southern Alaska and the Pacific margin of North America. End_of_Article - Last_Page 2504------------
Cell type specific inhibition of cAMP phosphodiesterase activity during terminal differentiation in Dictyostelium discoideum

Abstract Cyclic AMP phosphodiesterase (PDE) activity reaches a peak during the aggregation stage of development where it functions to regulate extracellular levels of cAMP. During the subsequent differentiation of the two cell types at the culmination stage, the activity reappears but only in stalk cells. We found that extracts from the culmination stage contained PDE which could be activated by preincubation with Mg 2+ and dithiothreitol (DTT), a treatment which is known to release an endogenous inhibitor from the aggregation stage enzyme. When the culmination stage extracts were subjected to chromatography on Biogel P300, two peaks of activity were eluted, PDE-I ( M r > 260,000) and PDE-II ( M r 100,000). Treatment of the fractions with Mg-DTT did not affect the low-molecular-weight enzyme but caused activation of the high-molecular-weight enzyme and the appearance of a third, intermediate form. Kinetic analysis of the two peaks revealed K m values for cAMP of 2 m M and 10 μ M for PDE-I and PDE-II, respectively. We tested the possibility that these forms of the enzyme might be distributed differently in the two cell types by measuring the K m for cAMP and the effect of Mg-DTT treatment on isolated sections of stalk and spore cells. The spore sections contained a high K m form of the enzyme (0.3 m M ) which was activated by preincubation with Mg · DTT whereas stalk sections contained a low K m form (3 μ M ) which was not affected by the activation treatment. We conclude that both cell types contain enzyme protein and that the apparent localization of PDE activity in stalk cells is due to the inhibition of activity in spore cells.
Relationship of air lead and blood lead for workers at an automobile battery factory.

Air lead and blood lead data, recorded over a period of 3 years for 972 employees at an automobile battery factory as part of a lead control program, were summarized and statistically analyzed. The air lead values were measured by mobile area samplers for approximately 2 years and then by personal samplers for approximately 1 year. Blood lead analyses were usually performed once a month for most of the workers. The trend in air lead levels was significantly upward in the 1st year and significantly downward in the 2nd year while the trend in blood lead levels was significantly downward in the 1st year and in the 3rd year. There were no other significant trends. To assess the relationship between air lead and blood lead, data were used whenever an air lead obtained by personal sampler was followed within 1 month by a blood lead on the same worker. The variables age, job tenure, and department identity were included in an analysis of covariance. Only air lead and departments were significant, accounting for 9% and 13% of the variance in blood lead, respectively. From these data 95% confidence limits were calculated for predicting blood leads from given air leads for an individual worker. These were 30–68 μg/100 ml at 200 μg/m3; 25–62 μg/ 100 ml at 100 μg/m3, and 22–60 μg/100 ml at 50 μg/m3.
Fetal rhesus monkey model of obstructive renal dysplasia

Fetal rhesus monkey model of obstructive renal dysplasia. Background Disorders of kidney development represent a major cause of renal failure and end-stage renal disease in the pediatric population. To understand further the prenatal pathogenesis of obstructive renal dysplasia, a fetal monkey model was developed using ultrasound-guided techniques. Methods Ureteropelvic obstruction ( N = 13) was induced during the early or late second trimester by the injection of purified guluronic alginate spheres. All fetuses were monitored sonographically, and then fetal tissues were removed at varying time points during the second and third trimesters. Results There was no evidence of oligohydramnios during the course of gestation, and the obstructed kidneys were typically progressively smaller than the contralateral (nonobstructed) kidneys when monitored sonographically over time. Obstructed kidneys displayed most features of renal dysplasia, including numerous cortical cysts of various sizes derived predominantly from collecting ducts and glomeruli. Mesenchymal changes included expansion of both the cortical and medullary interstitium, as well as mesenchymal-myocyte transformation, expressed as pericystic and peritubular fibromuscular collar formation. An important feature of this model was the disruption of normal glomerular development and architecture, associated with significant podocyte apoptosis, evident as early as the prevascularized S-shaped nephron. As in other models, collecting duct cell apoptosis was apparent, particularly in areas of cyst formation and cellular atrophy. Conclusions These results demonstrate the importance of this nonhuman primate model for exploring the pathophysiology of congenital obstructive uropathy and highlight the potential role of podocyte injury in determining long-term renal function associated with this condition.
The Effect of Video Feedback on the Social Behavior of an Adolescent With ADHD

Objective: The social functioning of adolescents with ADHD is characteristically impaired, yet almost no interventions effectively address the peer relationships of these youth. This study evaluate...
Health of Working Mothers and Their Children

Edited by Jacquelyn H. Flaskerud, RN, PhD, FAANSchool of Nursing, University of California, Los Angeles, CAIn an interview with Laura Rico, University of California, Irvine (UCI) Communications, Dr...
Artificial gravity--head movements during short-radius centrifugation: influence of cognitive effects.

Abstract Short-radius centrifugation is a potential countermeasure against the effects of prolonged weightlessness. Head movements in a rotating environment, however, induce serious side effects: inappropriate vestibular ocular reflexes (VOR), body-tilt illusions and motion sickness induced by cross-coupled accelerations on a rotating platform. These are well predicted by a semicircular canal model. The present study investigates cognitive effects on the inappropriate VOR and the illusory sensations experienced by subjects rotating on a short-radius centrifuge (SRC). Subjects ( N = 19 ) were placed supine on a rotating horizontal bed with their head at the center of rotation. To investigate the extent to which they could control their sensations voluntarily, subjects were asked alternatively to “fight” (i.e. to try to resist and suppress) those sensations, or to “go” with (i.e. try to enhance or, at least, acquiesce in) them. The only significant effect on the VOR of this cognitive intervention was to diminish the time constant characterizing the decay of the nystagmus in subjects who had performed the “go” (rather than the “fight”) trials. However, illusory sensations, as measured by reported subjective intensities, were significantly less intense during the “fight” than during the “go” trials. These measurements also verified an asymmetry in illusory sensation known from earlier experiments: the illusory sensations are greater when the head is rotated from right ear down (RED) to nose up (NU) posture than from NU to RED. The subjects habituated, modestly, to the rotation between their first and second sequences of trials, but showed no better (or worse) suppression of illusory sensations thereafter. No significant difference in habituation was observed between the “fight” and “go” trials.
Characteristic role of crosslinker on thermally induced volumetric contraction–expansion processes in poly(N‐isopropylacrylamide) networks and water systems

In this work, the degree of crosslinking on the volumetric contraction–expansion processes of hydrogels made of poly(N-isopropylacrylamide) (NIPA) (initial amount: Cm) with varied amount (z) of crosslinking agent methylene-bis-acrylamide (BIS) in reference to most commonly used NIPA gel that was synthesized with Cm = 700 mM and z = 8.6 mM was investigated by applying our recently developed pycnometry. We focused on characteristic role of four polymeric NIPA residues directly bonded to a single BIS molecule by evaluating the total volume of gels per four NIPA residues directly bonded to a BIS molecule, plus associated water [νsp(gel)(NIPA)bonded)(T)], and the corresponding number of water molecules per four NIPA residues [Ns(gel)(NIPA)bonded)(T)]. We elucidated how these quantities characteristically contribute to changes in the volumetric contraction–expansion processes of hydrogels. A comparison of these quantities with the corresponding quantities for (NIPA)unbonded residues clearly revealed a significant structural difference between (NIPA)bonded and (NIPA)unbonded. © 2009 Wiley Periodicals, Inc. J Appl Polym Sci, 2009
Electrohydrodynamic precipitator flow with a barbed plate discharge electrode

The nonuniform corona discharge in the wire-plate electrostatic precipitator results in a rotational electric body force which is a source of large-scale secondary flows and turbulence within the flow channel. The electrically induced flow causes large increases in diffusivities detrimental to the particle collection process. Since the electrode geometry and the structure of the corona discharge define the magnitude and character of the electric body force, it is theoretically possible to design a discharge electrode which minimizes electrohydrodynamic flow disturbances. As a first step in this direction, a novel planar electrode design in which electrical discharges are configured to reduce the inhomogeneities of the electric body force is experimentally studied in a negative polarity laboratory electrostatic precipitator. Hot-film anemometer measurements of the electrohydrodynamic turbulent velocity field downstream of the plate electrode are compared to those of a conventional wire-plate precipitator. ...
Poverty and Test Performance

AbstractStudents from poverty, as a group, never score or rank as high or higher on standardized tests as their wealthier peers. An analysis of data from national and international tests given since 2011 illustrates some of the deleterious effects of poverty on the standardized test output of American students.
Transmission imaging with a compact gamma camera: initial results for mammotomography

A dedicated single photon emission prototype imaging system is intended for fully 3D Application Specific Emission and Transmission Tomography (ASETT), where one specific application is dedicated breast imaging. In breast imaging, this dual-modality system may be useful for (1) improving detectability of low contrast lesions with X-ray CT imaging, (2) emission quantification using the transmission images, and (3) better interpretation of the reconstructed emission data by facilitating objective region selection. Each imaging component needs independent development, optimization and characterization. The prototype SPECT component using a NaI(Tl) based gamma camera has been built and initially evaluated with small, low contrast breast lesions; resolution and sampling issues ire under investigation with the arbitrary orbits possible with the hemispherical positioning capability.
The clinically unrecognized Q-wave myocardial infarction: what does it mean and what should we do?

Since the original description of clinically unrecognized myocardial infarction in 1912 by Herrick, several epidemiologic studies have shown that clinically unrecognized myocardial infarctions, as detected by the presence of abnormal Q waves on surveillance electrocardiograms, may represent between 20% and 40% of all myocardial infarctions. Importantly, these clinically unrecognized Q-wave myocardial infarctions carry a prognosis similar to those infarctions that are clinically recognized. Despite significant data describing the prevalence and adverse prognosis associated with clinically unrecognized Q-wave myocardial infarctions, there are several unresolved issues regarding the clinical entity of unrecognized Q-wave myocardial infarction. The prevalence estimates derived from epidemiologic studies vary substantially, a finding that is likely attributed to the heterogeneity in the definitions used. A gold standard for the definition of a clinically unrecognized Q-wave myocardial infarction does not exist, and multiple diagnostic criteria have been applied in epidemiologic studies. In addition, the reliance of Q waves on the electrocardiogram to establish the diagnosis limits the ability to identify clinically unrecognized non–Q-wave infarctions, which comprise a significant proportion of all myocardial infarctions. Alternatively, Q-wave abnormalities may be seen in a variety of conditions other than a myocardial infarction, including conduction abnormalities, ventricular hypertrophy, myocardial infiltration, anatomical rotation of the heart, and electrocardiographic lead placement errors. Not much is known regarding the predisposing conditions that are associated with clinically unrecognized Q-wave myocardial infarction. Although certain cardiac risk factors such as age, hypertension, and diabetes have been suggested to predispose to the development of unrecognized Q-wave myocardial infarctions, multivariable analyses suggest that these risk factors are simply the traditional risk factors for coronary