cssi/SciSciGPT-SciSciNet huggingface dataset:
Epidural hematoma secondary to a rupture of a synovial cyst

Abstract Background content With modern advances in imaging studies, synovial cysts are becoming more evident as a common component of erosive lumbar degenerative disc disease causing spinal stenosis and radiculopathy. Whereas hemorrhage can occur inside the cyst and is reported, rupture causing epidural hematoma is a rare complication and finding of this disorder. Purpose To report a rare clinical presentation of a synovial cyst and spinal stenosis, where rupture of the cyst leads to an early cauda equina syndrome. Study design Case report with a review of literature. Methods Clinical history, physical findings, and magnetic resonance imaging studies of a patient with an intraspinal synovial cyst at L4-5 1 week before a sudden worsening of symptoms are reported. Results A case report is presented of a male with a known synovial cyst at L4-5, presenting initially with neurogenic claudication. This patient developed sudden worsening of symptoms with bilateral lower extremity pain, weakness, and radiculopathy with difficult voiding. The patient had developed an epidural hematoma, secondary to rupture of a synovial cyst, documented at surgical decompression. Conclusions Although synovial cyst associated with erosive facet and erosive degenerative disc disease are common, rupture of the cyst is not. A case report of a ruptured synovial cyst leading to an early cauda equina syndrome is presented. This case illustrates the spectrum of clinical features and presentations possible with spinal stenosis complicated by lumbar synovial cyst formation.
Propagation dynamics of controllable cross-talk in double-ladder system

We theoretically and experimentally investigate the propagation dynamics and controllability of cross-talk between two probes in a double-ladder system via interplay of X(1) and X(3) processes.
Measurements of a distributed file system

We analyzed the user-level file access patterns and caching behavior of the Sprite distributed file system. The first part of our analysis repeated a study done in 1985 of the: BSD UNIX file system. We found that file throughput has increased by a factor of 20 to an average of 8 Kbytes per second per active user over 10-minute intervals, and that the use of process migration for load sharing increased burst rates by another factor of six. Also, many more very large (multi-megabyte) files are in use today than in 1985. The second part of our analysis measured the behavior of Sprite's main-memory file caches. Client-level caches average about 7 Mbytes in size (about one-quarter to one-third of main memory) and filter out about 50% of the traffic between clients and servers. 35% of the remaining server traffic is caused by paging, even on workstations with large memories. We found that client cache consistency is needed to prevent stale data errors, but that it is not invoked often enough to degrade overall system performance.
Stimulated Brillouin Scattering in Liquids

Stimulated Brillouin scattering in various liquids is examined in a transverse resonator and in a backward-wave oscillator. Comparison with elementary resonator theory indicates that the data are in satisfactory agreement for many liquids. The theoretical picture for the unstable backward-wave configuration is complicated by phonon transit-time effects, but even here the results establish guidelines for the theory. It is found necessary to discard the results for some liquids because of self-focusing and other nonlinear processes which interfere with the Brillouin effect.
Controlled and comparative trials with valproate: United States.

Valproic acid (VPA) was released for general use in the United States in 1978. Since that time the use of VPA has steadily grown, and considerable literature on valproate from the United States has resulted. Despite this fact, however, very few studies that were either well controlled or compared the efficacy of VPA with that of another standard anticonvulsant drug have been published from this country.
Temperature dependant flash memory erase transient simulation (Part II)

We present a detailed and accurate physics based transient simulation for modeling flash memory erasing at ambient and non-ambient temperatures. Typical cells are erased by moving electrons from the floating gate to the drain, source or substrate. Part 1 of this paper derives the equations used to model substrate erasing. This paper addresses drain erase modeling using a simulation based on the solution to Poisson's equation with temperature as an independent variable. The goal of this paper is to demonstrate the derivation of an accurate erase simulation and show the effects of temperature on the threshold voltage during the erase process. Several papers have been published on this topic but fail to present detailed derivations and none using this exact set of equations to model the temperature dependent erasing process.
Alice without a looking glass: Blind people and body image

This paper is a study of blind people's 'body image'. Starting with the hypothesis that-without mirrors for visual surveillance-blind people's sense of their bodies and selves are 'embodied' (focused on corporeal experience rather than on appearance), this article examines what blind people know about their bodies, how they imagine their bodies, how their identities relate to their blindness, and how they experience their bodies. From interviews with 13 blind people in England (one adult woman, nine female adolescents, and three male adolescents), several conclusions are drawn about each of the above areas of enquiry (knowledge, self-image, identity, and experience). The most significant result to emerge is a refutation of the initial hypothesis: blind people are by and large quite concerned with their appearance (they are extremely self-conscious) and place very little emphasis on their corporeal experiences.
R2 Library Review

The R2 Library is an electronic book product designed by Rittenhouse Book Distributors for medicine, nursing, and allied health professionals. This article describes the contents and features of the Library, as well as appraises the navigation and searching functions. This article also notes special features of the R2 Library, such as an institutional administration module and an individual user section called My R2.
Effects of nadolol on blood pressure, sleep efficiency, and sleep stages

The effects of nadolol (20 and 80 mg) on blood pressure and sleep parameters were assessed in six patients with mild hypertension. A 32-night experimental protocol in the sleep laboratory was instituted consisting of four placebo-baseline nights followed by 4 weeks of drug administration. Both doses of nadolol had a clear-cut and consistent lowering effect on blood pressure throughout the night and during the day, with a greater reduction noted with the 80 mg dose. In fact, blood pressure values were reduced to normotensive levels. Neither dose had a disrupting effect on sleep, whereas the 80 mg dose improved sleep efficiency and also had a rapid eye movement-enhancing effect. This absence of sleep-disrupting effects is attributed to nadolol's low level of lipophilicity and lack of intrinsic sympathomimetic activity. The clinical significance of the lack of sleep disruption and possible improvement of sleep with nadolol is discussed in light of the well-recognized sleep disturbances produced by other β-blockers. Clinical Pharmacology and Therapeutics (1988) 43, 655–662; doi:10.1038/clpt.1988.91
Development of Future Habitat Suitability Models for the Swift fox (Vulpes velox) in the American Southwest

The Swift fox (Vupes velox) is a habitat specialist species of short or mixed grass prairie. We used bioclimatic envelope models and habitat suitability models under three future climate scenarios (based on CO2 emission rates) from "www.climatewizard.org":http://www.climatewizard.org to fit species distribution models, using the maximum entropy method. Current suitable habitat for the swift fox covers an area of 161,984 km2. Under the future climate scenarios the habitat decreases by 27% in the low emission scenario, 63% for medium emissions, and 53% in the high emissions scenario. This decrease in suitable habitat corresponded to an overall decrease in total grassland landcover. The current total area of grassland is 423,440 km2. Under the future climate scenarios the grassland decreased by 12% in the low emissions scenario, 24% for medium emissions, and 16% in the high emissions scenario.
Greening the Optical Backbone Network: A Traffic Engineering Approach

Since telecom networks consume a large (and increasing) amount of energy, "green" strategies are desirable to help Service Providers (SP) operate their networks and provision services more energy-efficiently. In this study, we focus on operating optical backbone networks with green strategies. We consider a typical optical backbone network architecture, and minimize the Operational Power for service provisioning following a Traffic Engineering (TE) approach. Service provisioning is schematically decomposed as multiple serial operations, and power efficiency is analyzed for both optical bypass and traffic grooming. We propose a novel auxiliary graph, which can capture the flow of operations and their associated power. Based on the auxiliary graph, we present a Power-Aware scheme that minimizes the Operational Power. Simulation results show reduced power consumption by our scheme, in comparison to a generic traffic grooming approach.
Cor pulmonale in cystic fibrosis of the pancreas

Observations of vital capacity and cardiac hemodynamics were made on 21 patients with cystic fibrosis. The data suggest that severity of disease, vital capacity, and response of Pa O 2 to breathing 100 per cent oxygen may provide useful information in the recognition of cor pulmonale.
Hydrolysis of cellobiose by immobilized β-glucosidase entrapped in maintenance-free gel spheres

A crude preparation of Aspergillus niger β-glucosidase (27.5 cello-biase U/mg protein at 40°C, pH 5.0) was immobilized on concanavalin A-Sepharose (CAS). The cellobiase activity of the immobilized enzyme was 1334 U/mg dried CAS or 108 U/mL CAS gel. The β-glucosidase-CAS complex was entrapped within crosslinked propylene glycol alginate/bone-geletin gel spheres that possessed between 0.67 and 2.35 cellobiase U/mL spheres, depending on their size. The effect of cellobiose concentration (10–300 mM) on the activity of native, immobilized, and gel-entrapped enzyme was determined. It was shown that concentrations of cellobiose between 10 and 180 mM were not inhibitory to the entrapped enzyme, although inhibition was found to occur with the native and immobilized enzyme. Exogenous ion addition was not necessary to maintain the structural integrity of the spheres, which were stable for 4 d at 40°C.
La Bette noire de Balzac

La Comedie humaine aurait aussi bien pu etre intitulee la Comedie animale, les metaphores zoologiques etant si nombreuses. Si le Pere Goriot est souvent considere comme le roman pivotai de l'œuvre balzacienne, la Cousine Bette — homonymie aidant — pourrait jouer un role equivalent dans cette Comedie animale. Il suffit de consulter XAvant-propos, de la Comedie humaine pour trouver confirmation du theme animalier. Dans le troisieme paragraphe — qui consiste en une phrase — Balzac declare que l'idee de son œuvre "vint d'une comparaison entre l'Humanite et l'Animalite". L'auteur va plus loin en affirmant non plus l'existence de deux especes distinctes, l 'homo sapiens et l'animal, mais d'une seule: "il n'y a qu'un animal. Le createur ne s'est servi que d'un seul et meme patron pour tous les etres organises." L'homme n'est alors qu'une des especes animales, et non plus l'etre superieur et central, l'homo faber des especes vivantes; la societe, a son tour, n'est plus qu'une des variantes de la nature: "la societe ressemblait a la nature. La societe ne fait-elle pas de l'homme, suivant les milieux ou son action se deploie, autant d'hommes differents qu'il y a de varietes en zoologie?" L'humanite et l'animalite ne sont plus deux especes paralleles (dans le sens strict du terme: qui se cotoient sans jamais se rencontrer) ou meme asymptotiques mais bien au contraire convergentes puisque "l'Animalite se transborde dans l'Humanite par un immense courant de vie".
Mesoscale synchrony in quaking aspen establishment across the interior western US

Abstract Concern and debate about the condition of quaking aspen in the intermountain West of North America have led to many studies examining aspen recruitment at local to landscape scales. Patterns of aspen mortality and recruitment may reflect local conditions, or may show broad synchrony if regional-scale drivers are important. This paper aggregates historical aspen establishment data from 12 case studies from nine locations in a meta-analysis of emergent patterns of aspen dynamics at sub-continental or mesoscales (104–106 km2). Aspen establishment data were reported in multiple forms among studies, so the meta-analysis included two approaches (1) a quantitative analysis of percent aspen establishment in decadal time bins for 1820–1999 for six studies that reported data in a format suited for this approach and (2) a qualitative ranking of 19th and 20th century peaks in aspen establishment for all 12 studies. Aspen forests ranging from Wyoming to northern Arizona experienced two peaks in establishment between 1820 and the 1980s. The first peak began in the 1860s, reached its maximum in the 1880s, and gradually declined to an end the 1910s. The second peak began abruptly in the 1970s and continued through the 1980s. I speculate that the late-1800s peak in aspen recruitment was driven primarily by the occurrence of the last historical fires throughout the intermountain West and that the 1970s and 1980s peak was driven by improved moisture conditions brought about by a shift to a positive phase of the Pacific Decadal Oscillation and a persistent negative phase of the Atlantic Multidecadal Oscillation. The overarching implication of large-scale synchrony in aspen dynamics is that current aspen ecosystem condition is not solely the result of local-scale histories of browsing or fire, but is more likely the interwoven legacy of these local factors combined with broad factors such as climate and Euro-American settlement.
The kinetics of methyl bromide hydrate formation

Abstract The rate of formation of methyl bromide hydrate in a continuous stirred tank reactor has been measured under conditions in which the ΔT driving force, the degree of agitation, the salt concentration in the aqueous phase, the volume fraction of liquid methyl bromide present and the fraction of solids present in the slurry were all varied. As long as the agitation intensity is over 0.01 hp/gal and there is at least 3 volume % liquid methyl bromide present in the reactor, the hydrate formation rate appears to be controlled mainly by the kinetics of the interfacial reaction to form crystals. Under these conditions only 10% to 25% of the total driving force is used to boil the refrigerant while the remainder is consumed by the interfacial reaction. This is in contrast to the butane freezing process where nearly all the ΔT is consumed by boiling of the refrigerant. With a slurry solids concentration of 15% and a ΔT of 2.5°C specific reaction rates are over 60 lbs of water solidified per hour per ft3 of slurry.
Deep-ultraviolet resonance Raman spectroscopy for chemical sensing

Resonance Raman spectroscopy is an emerging spectroscopy tool capable of highly specific and highly sensitive analysis of biological molecules in solutions. The complexity of experimental set-up and reliance on laser sources with very short life-time and very high maintenance requirement were always considered the major bottle-neck problem on the way of wide spread of applications of deep-UV Raman spectroscopy in biology and medicine. In this report, we present the design of a very inexpensive system based on a diode-pumped solid-state laser system capable of performing Raman analysis in the deep UV.
Detonation initiation behind an accelerating shock wave

The propagation of an incident step shock wave through a convergent channel containing an explosive gaseous mixture has been studied both theoretically and experimentally. It is shown that under the proper conditions the first appearance of rapid heat release in the mixture will occur near the accelerating shock wave by strictly homogeneous reaction kinetic processes. The subsequent appearance of detonation is observed experimentally but its development has not been discussed quantitatively since the present theory only predicts the location of the first initiation point.
The mod-2 cohomology of metacyclic 2-groups

In this paper we will compute the cohomology rings of the title as algebras over the Steenrod algebra A2. In so doing we introduce an extremely useful application of the Eilenberg-Moore spectral sequence suggested by Lambe. The cohomology calculations have been known for some time for certain special classes of these groups. This background material may be found in [3]. We wish to handle the calculations systematically and with regard to the Steenrod algebra. We summarize our results in
Response to Letter Regarding Article, “Selecting a Noninvasive Imaging Study After an Inconclusive Exercise Test”

We thank Schuster et al for their interest in our clinician update article,1 and for their thoughtful comments. We believe that many low-risk patients who are able to exercise and have a normal baseline ECG can be effectively evaluated with exercise treadmill testing. In our institution, despite the availability of many advanced imaging modalities, exercise treadmill testing remains the most commonly performed initial test for this patient population, an approach that is also supported by current guidelines.2,3 Although we certainly agree that the diagnostic accuracy of ECG changes to detect ischemia is lower than other noninvasive techniques, it is important to note …
New high-performance PtSi IRCCD and its electrical shutter operation

In this work the design and performance of a 537 (H) x505 (V) -element PtSi Schottky-barrier diode (SBD) IRCCD are described. To downsize the JR camera, the pixel size of the IRCCD has been reduced to 15.2mx11.8jtm. The package size of the IRCCD is l4mmxl4mm. The reduction of the pixel size causes a decrease in thermal sensitivity. However, the noise equivalent temperature difference (NETD) of the IRCCD is less than 0.13°C, because the transfer conversion gain from the electrons to the voltage has been increased, by decreasing the capacitance of its FDA. Furthermore, the NETD can be decreased to 0.1 1°C by increasing the platinum deposition temperature to 340°C. The IRCCD has an electrical shutter function with which the exposure time can be varied from 1/500 second to 1/5000 second. In addition, the IRCCD has a mixed-signal-mode shutter function, which was developed to expand the dynamic range. The mixed-signal-mode shutter function is performed by mixing the signal electrons of two kinds of pixels, one shuttered and the other unshuttered. The IRCCD also has a temperature monitor diode on a chip to control the cooling system of the JR camera. However, inclusion of this diode causes an increase in the fixed pattern noise. To reduce this noise, the monitor diode is forward biased for only a moment for temperature measurement. Keywords: PtSi SBD IRCCD, downsizing, electrical shutter, temperature monitor diode
Neuroimaging in Mild Traumatic Brain Injury

Neuroimaging in mild traumatic brain injury (mTBI) is reviewed. While computed tomography remains the acute standard for neuroimaging of mTBI, it is only sensitive to gross abnormalities and is typically performed as a measure to rule out more serious and life-threatening injury. Magnetic resonance imaging (MRI), especially at field strength of 3.0 T, is the follow-up neuroimaging standard for assessing potential underlying structural injury to the brain. Several MRI sequences are particularly sensitive to subtle hemorrhagic lesions and signal abnormalities in white matter, sensitive enough to detect pathology when present in mTBI. Clinical correlation of neuropsychological outcome with neuroimaging findings is discussed along with the future potential for functional neuroimaging in evaluating the mTBI patient.
Efficacy of a brief acute neurobehavioural intervention following traumatic brain injury: a preliminary investigation.

Primary objective: To evaluate the effectiveness of a brief acute neurobehavioural intervention, the First Steps Acute Neurobehavioural and Cognitive Intervention (FANCI), with persons who have traumatic brain injury (TBI).Research design: Prospective, controlled, repeated measures design.Methods and procedures: Seventy-two patients in acute TBI rehabilitation participated either as FANCI subjects or as control participants who watched videos to control for time and attention. Outcome measures included the Neurobehavioural Rating Scale-Revised (NRS-R), Functional Independence Measure (FIM™), a FANCI Learning Assessment (LA) and the Satisfaction with Life Scale (SWLS).Main outcomes and results: In comparison with controls, FANCI participants had significantly greater neurobehavioural (cognitive, emotional and behavioural) as well as FIM motor improvements. Significantly greater learning occurred and persisted over time for FANCI subjects as compared to controls. Pre-treatment cognitive and neurobehavioural...
Is there an intrinsic linear term in the specific heat of YBa2Cu3O7

Abstract A reanalysis of specific-heat data suggests the existence of an intrinsic contribution to the linear term of the order of 2 mJ/mole. K 2 in YBCO. On the basis of comparison with other high-T c oxide superconductors it appears that the intrinsic contribution may be unique to YBCO, and therefore probably associated with the CuO chains.
Radiometric determination of thorium, uranium and potassium in basalts and in two magmatic differentiation series

Abstract Thorium, uranium and potassium contents of basalts and other basic rocks have been measured by gamma-ray spectrometry. The ratios of Th/K, U/K and Th/U are constant within one order of magnitude in a wide variety of rock types. The averages for basalts are: Th/K × 104 = 2.8, U/K × 104 = 0.60 and Th/U = 4.8. Some tendency exists, however, for increase in these ratios with igneous differentiation, as shown by investigations of the Duluth and Southern California intrusive sequences. The Th/U ratio is particularly low in tholeiites (1·6) from the orogenically active Japanese area and is also lower in the basic rocks of the Duluth and Southern California sequences than in most basalts. Apparently the process which leads to the formation of magma in orogenic areas causes removal of thorium, potassium and to a lesser extent, uranium from source materials before intrusion or eruption. Close relationship between potassium content and Th/U ratio in basic rocks from widely separated areas, however, suggests that the subcrust in which basic magmas originate is compositionally uniform and differences between the compositions of primary basalt magmas are probably the result of local processes.
Medically unresponsive foot pain treated successfully with acupuncture

A study of 67 patients with chronic foot pain treated with an average 4 to 5 acupuncture sessions, demonstrated excellent objective and subjective relief in 50. Clinical records were searched to find the number of medication prescriptions and physical therapy treatments given in the year prior to the start of acupuncture treatment, and these figures were compared to those for the subsequent year. A standard, paired Meridian approach in 16 patients was compared to a simple 5 point treatment in 51. This simple method appears superior. Therapy failed (<25% benefit) in 13%. It was effective in 3 out of 5 with reflex sympathetic dystrophy symptoms in the foot. A beneficial response to acupuncture was statistically less likely (P=0.04) in patients with major trauma or surgery to the foot.
Butterfly Automorphisms and Edge Faults

This paper obtains all the automorphisms of a wrapped Butterfly network of degree n using an algebraic model. It also investigates the translation of butterfly edges by automorphisms. It proposes a new strategy for algorithm mappings on an architecture with faulty edges. This strategy essentially consists of finding an automorphism that would map the faulty edges to the free edges in the graph. Having a set of n2^ (n+1) well defined simple automorphisms which translate graph edges deterministically, makes this a very powerful technique for dealing with edge faults. We illustrate the technique by mapping Hamilton cycle on the butterfly under various edge fault scenarios.
Treatments patterns of vulvar cancer in the elderly

Abstract Objective : To evaluate treatment patterns of vulvar cancer in patients over 80 years. Material and Methods : Between 1979 and 1999, the Geneva Tumor Registry identified 230 women with vulvar cancer. Treatment of patients over 80 years and younger were compared. Kaplan-Meier analysis was used to determine disease specific cumulative survival. Results : Young women are more likely to present in situ lesions compared to their older counterparts. Majority of vulvar cancers were observed in women ⩾80 ( p 0.001 ) at more advanced stages. Elderly women have either no treatment, either unconventional or inadequate treatments. The Mantel-Haentzel analysis shows a 23.4 OR (IC (95%) 2.9–186.6) of not being treated if the patient is over 80. Specific 5-years survival was 93% in stage I, compared to 21% in stage IV. Conclusion : Patients over 80 years are diagnosed at more advanced stages. Less aggressive treatments decrease outcome.
Monitoring Invasive Species: Detecting Purple Loosestrife and Evaluating Biocontrol along the Niobrara River, Nebraska

Geospatial tools and techniques are playing important roles in determining the location and spatial extents of invasive species infestations and in evaluating the performances of various management activities aimed at controlling their spread. In this study, hyperspectral image processing techniques were used to map purple loosestrife and to assess the effectiveness of biological control agents in controlling its infestations along the Niobrara River in Nebraska. Validation based on field survey showed an overall map accuracy of 82.1% and comparison with in situ data on biocontrol release indicated that biocontrol agents were effective in the areas where they were released.
Identification of 17,20β,21-trihydroxy-4-pregnen-3-one (20β-S) receptor binding and membrane progestin receptor alpha on southern flounder sperm (Paralichthys lethostigma) and their likely role in 20β-S stimulation of sperm hypermotility.

Abstract The existence of direct progestin actions on teleost sperm to stimulate hypermotility is not widely acknowledged because it has only been demonstrated in members of the family Sciaenidae. In the present study, progestin stimulation of sperm hypermotility was investigated in a non-sciaenid, southern flounder, and the potential role of membrane progestin receptor alpha (mPRα or Paqr7b) in mediating this action was examined. The major progestin produced in vitro by flounder testicular fragments co-migrated with 17,20β,21-trihydroxy-4-pregnen-3-one (20β-S) during thin-layer chromatography. Treatment of flounder sperm with 5 nM-100 nM 20β-S significantly increased sperm velocity in vitro , whereas 17,20β-dihydroxy-4-pregnen-3-one and other steroids were ineffective. A single class of high affinity ( K d 22.95 nM), saturable, limited-capacity binding sites ( B max 0.013 nM) specific for 20β-S was identified on sperm membranes. Treatment of sperm membranes with guanosine 5′-(3- O -thio)triphosphate reduced [ 3 H]-20β-S binding, suggesting the 20β-S receptor couples to a G protein. The membrane adenylyl cyclase inhibitor 2′,5′-dideoxyadenosine blocked 20β-S-induced sperm hypermotility, indicating 20β-S activates stimulatory G proteins. Finally, flounder paqr7b was cloned and characterized from testicular tissues. The Paqr7b protein is expressed on the midpiece of flounder sperm and is more abundant in individuals with high sperm motility than low motility donors. These findings suggest that 20β-S stimulates sperm hypermotility in flounder through activation of stimulatory G proteins, likely through Paqr7b. The finding that progestins directly stimulate sperm hypermotility in a flatfish, a highly derived species not belonging to the teleost family Sciaenidae, suggests this phenomenon is widespread among advanced fishes.
A murine leukemia virus mutant with a temperature-sensitive defect in membrane glycoprotein synthesis

Cells infected with a temperature-sensitive mutant (ts-26) of Rauscher murine leukemia virus (R-MuLV) or with wild-type virus were labeled with 35S-methionine, and cell extracts were examined for radioactive polypeptides which could be precipitated by monospecific antisera to viral proteins. When shifted from permissive (31 degrees C) to nonpermissive (39 degrees C) temperature, cells infected with ts-26 rapidly begin to accumulate gPr90enr, the glycoprotein precursor to the membrane envelope glycoprotein gp70 and to the membrane-associated protein p15E. Simultaneously, formation of these mature virion proteins ceases. In addition, lactoperoxidase-catalyzed surface labeling with 125I--iodine indicates that the plasma membrane of cells infected with ts-26 becomes depleted of gp70 antigens at 39 degrees C. Nevertheless, at 39 degrees C these cells release defective MuLVs which lack gp70 and p15E but contain an outer membrane. The released particles also contain an aberrantly processed form of the major virion core protein p30, and many of these virion cores have an unusual immature crescent shape. It has previously been reported that cells infected with the ts-26 mutant of R-MuLV process a 65,000 dalton precursor (Pr65gag) of the virion core proteins more slowly at 39 degrees C than do cells infected with wild-type virus (Stephenson, Tronick and Aaronson, 1975). Although we have confirmed these results, this effect is relatively small and it is known that various alterations of MuLV assembly can lead secondarily to inhibited processing of Pr65gag. We propose that the ts-26 mutant has a primary temperature-sensitive defect in membrane glycoprotein synthesis and that this change causes pleiotropic effects on core morphogenesis.
High G MEMS integrated accelerometer

This paper describes the design and implementation of a surface micromachined accelerometer for measuring very high levels of acceleration (up to 50,000 G). Both the mechanical and electronic portions of the sensor were integrated on a single substrate using a process developed at Sandia National Laboratories. In this process, the mechanical components of the sensor were first fabricated at the bottom of a trench etched into the water substrate. The trench was then filled with oxide and sealed to protect the mechanical components during subsequent microelectronics processing. The wafer surface was then planarized in preparation for CMOS processing using Chemical Mechanical Polishing (CMP). Next, the CMOS electronics were fabricated on areas of the wafer adjacent to the embedded structures. Finally, the mechanical structures were released and the sensor tested. The mechanical structure of the sensor consisted of two polysilicon plate masses suspended by multiple springs (cantilevered beam structures) over corresponding polysilicon plates fixed to the substrate to form two parallel plate capacitors. The first polysilicon plate mass was suspended using compliant springs (cantilever beams) and acted as a variable capacitor during sensor acceleration. The second polysilicon plate mass was suspended using very stiff springs and acted as a fixed capacitormore » during acceleration. Acceleration was measured by comparing the capacitance of the variable capacitor (compliant suspension) with the fixed capacitance (stiff suspension).« less
Trash in cache: detecting eternally silent stores

The gap between processing and storage speeds remains a concern for computer system designers and application developers. This disparity can be bridged in part by eliminating unnecessary stores, thereby reducing the amount of traffic that flows from the processor and first-level caches to the slower components of the storage subsystem. Reducing the "write" traffic can improve program performance, save power, and increase the longevity of storage components that have limited write endurance. Techniques have been proposed and evaluated for identifying various classes of stores that can be silenced. A relatively unexplored class of such stores are those that would write data that is dirty, but dead. Such data appears as if it needs to be written back to memory from cache, yet it can be proven that the application can never subsequently access the data.In this paper, we suggest identifying garbage (trash) in cache, so that the dirty bytes associated with the trash need not be written to memory. We propose and evaluate a simple technique based on reference counting that finds a subset of these "eternally silent" (dead) stores. When applied to popular benchmarks, our results show that a significant fraction of the writes to memory can be silenced based on the impossibility of an application subsequently accessing the data.
A combined first-arrival travel time and reflection coherency optimization approach to velocity estimation

We present a nonlinear optimization method for two-dimensional velocity estimation in strongly heterogeneous media. We achieve this by designing a simulated-annealing algorithm to simultaneously maximize reflection coherency as well as minimize first-arrival travel time residuals. Relatively shallow velocity structure is constrained by first-arrival times, while coherency information from deeper reflections (if present' helps constrain deeper velocities. Prestack migration using the optimized velocities images reflections with greater continuity, compared with other velocity estimation methods. Using synthetic and real data we demonstrate that migrations through velocities obtained using our coherency criterion reconstruct basin-boundary structures more accurately than through those obtained using only first-arrival times. Images from shot gathers collected along COCORP Mojave line 5 across the Garlock fault in Cantil Valley, California show new evidence of links between Garlock fault branches and sub-horizontal structures in the upper crust. Imaging reflections and estimating velocities using coherency annealing is more effective and less expensive than picking reflection times from shot gathers recorded complex regions.
Creating a Public Space for Women in US Agriculture: Empowerment, Organization and Social Change

This paper situates women in the public space of US agriculture by chronicling the development of the Women Food and Agriculture Network (WFAN). WFAN has grown from concern about systemic problems in agriculture; the dissonance between agricultural policy and women’s knowledge and experiences; a desire to give voice to women on issues of food, agriculture, community and natural systems; and the belief in women’s capacity to engage in a strategic and embodied agricultural politics. WFAN’s emergence reflects the often inhospitable terrain and organizational challenges for women in agriculture. The author, as participant observer, constructs a partial, second-order interpretation of WFAN as a potential social movement organization (SMO). She evokes the notion of direct theory, suggesting that WFAN theorizes about social change through practice, that member-theorists and member-activists contribute to social knowledge. WFAN’s formative structures, processes and practices are shown to parallel those of SMOs, associations of persons challenging dominant social constructions of what is realistic, reasonable, and ethical.
Nonparametric Bayesian models for a spatial covariance

A crucial step in the analysis of spatial data is to estimate the spatial correlation function that determines the relationship between a spatial process at two locations. The standard approach to selecting the appropriate correlation function is to use prior knowledge or exploratory analysis, such as a variogram analysis, to select the correct parametric correlation function. Rather that selecting a particular parametric correlation function, we treat the covariance function as an unknown function to be estimated from the data. We propose a flexible prior for the correlation function to provide robustness to the choice of correlation function. We specify the prior for the correlation function using spectral methods and the Dirichlet process prior, which is a common prior for an unknown distribution function. Our model does not require Gaussian data or spatial locations on a regular grid. The approach is demonstrated using a simulation study as well as an analysis of California air pollution data.
Assessing the sensitivity of methods for estimating principal causal effects.

The framework of principal stratification provides a way to think about treatment effects conditional on post-randomization variables, such as level of compliance. In particular, the complier average causal effect (CACE) – the effect of the treatment for those individuals who would comply with their treatment assignment under either treatment condition – is often of substantive interest. However, estimation of the CACE is not always straightforward, with a variety of estimation procedures and underlying assumptions, but little advice to help researchers select between methods. In this article, we discuss and examine two methods that rely on very different assumptions to estimate the CACE: a maximum likelihood (‘joint’) method that assumes the ‘exclusion restriction,’ (ER) and a propensity score-based method that relies on ‘principal ignorability.’ We detail the assumptions underlying each approach, and assess each methods' sensitivity to both its own assumptions and those of the other method using both si...
A precise method for the determination of whole blood and plasma sulfhydryl groups.

Abstract A colorimetric method for the determination of total sulfhydryl content whole blood or plasma is presented. For whole blood, a mixture of fresh blood and 5,5′-dithiobis(2-nitrobenzoic acid) in diluted buffer is separated on a gel column into the yellow anion and the hemoglobin fraction. The plasma-DTNB mixture was read directly, and a correction for turbidity and/or color made after addition of N -ethylmaleimide. Results of a sample of human bloods are presented. The effects of several detergents yield high values of sulfhydryl in whole blood, which we believe to be artifactual. Studies of the stability of stored blood samples indicate that whole blood, but not plasma, can be kept refrigerated for several days without significant loss of sulfhydryl reaction.
Twisted non-Abelian determinants on Riemann supersurfaces

We calculate the twisted supersymmetric determinants that are necessary for the study of the propagation of spinning strings on arbitrary orbifolds. We calculate the degeneration behaviour of multiloop amplitudes for twisted internal sectors. We use this to derive the spectrum of dimensions of twist fields.
Cn3D: sequence and structure views for Entrez.

We thank the NCBI structure group for their work in testing Cn3D versions 2.0 and 2.5. We also thank Patrick Durand, Jim Ostell, Tatiana Tatusova, Denis Vakatov, David Wheeler and the NCBI software group for useful criticism and help with the software toolkit. We thank the NIH Intramural Research Program for support.
TIME-DISTANCE HELIOSEISMOLOGY: NOISE ESTIMATION

As in global helioseismology, the dominant source of noise in time-distance helioseismology measurements is realization noise due to the stochastic nature of the excitation mechanism of solar oscillations. Characterizing noise is important for the interpretation and inversion of time-distance measurements. In this paper we introduce a robust definition of travel time that can be applied to very noisy data. We then derive a simple model for the full covariance matrix of the travel-time measurements. This model depends only on the expectation value of the filtered power spectrum and assumes that solar oscillations are stationary and homogeneous on the solar surface. The validity of the model is confirmed through comparison with SOHO MDI measurements in a quiet-Sun region. We show that the correlation length of the noise in the travel times is about half the dominant wavelength of the filtered power spectrum. We also show that the signal-to-noise ratio in quiet-Sun travel-time maps increases roughly as the square root of the observation time and is at maximum for a distance near half the length scale of supergranulation.
Caregiver Mental Health and Potentially Harmful Caregiving Behavior: The Central Role of Caregiver Anger

Purpose: Caregivers feeling stress and experiencing mental health problems can be at risk for engaging in abusive acts against elderly care recipients. Potentially harmful behavior (PHB) was used as a measure of caregivers ’ engagement in, or fear of engagement in, behavior that places dependent care recipients at risk of physical and/or psychological maltreatment and may be seen as an antecedent of, or a proxy for, identifi ably abusive behavior. The study examined the ability of anger to mediate and moderate the relations of depression, resentment, and anxiety with PBH. Design and Methods: Data are from the fi rst wave of the second Family Relationships in Late Life study of caregivers of communitydwelling elderly care recipients with whom they coreside. Caregivers ( N = 417) completed face-toface interviews. Results: Anger was found to mediate the relation between anxiety and PHB. Anger both mediates and moderates the relations of both depression and resentment with PHB in a dynamic way such that the mediating effect of anger increases substantially with increased scores on both depression and resentment. Implications: Identifying anger levels among caregivers who report symptoms of depression is warranted. Reducing depression in caregivers who report high levels of anger may result
Changes in tree species diversity after successive clearcuts in the Southern Appalachians

A 16 ha watershed in the Coweeta Basin was clearcut in 1939 and 1962. Vegetation was inventoried in 1934 and at about 7-year intervals to 1991. After the first clearcut, tree diversity remained high until after the second cut. Diversity based on density and basal area decreased significantly 14 years after the second clearcut and remained low through 1991. Diversity was highest in the early establishment stage of stand development, then declined at the intermediate stage with canopy closure. Evenness based on basal area declined more than evenness based on density because basal area of Liriodendron tulipifera increased substantially from 1977 to 1991. Trends in diversity were due to changes in evenness rather than changes in species richness.
Generalized fixed channel assignment in microcellular communication systems

Overlapping coverage areas of nearby base stations arise naturally in cellular communication systems-especially in small-cell, high-capacity microcellular configurations. Because of overlap, users may have access to channels at more than one base station. With an appropriate control strategy, this enhanced access can be used to improve teletraffic performance characteristics. The authors consider a generalized fixed channel assignment scheme with priority for hand-off calls. The scheme systematically accounts for and exploits coverage overlap in its channel assignment strategy. An analytically tractable model is developed for a linear array of cells, such as those that might be used along a highway. The effects of shadow fading are included. Overall performance characteristics that are computed account for both signal availability and channel availability. Blocking probability, forced termination probability, hand-off activity, and carried traffic are determined. >
Incremental learning in non-stationary environments with concept drift using a multiple classifier based approach

We outline an incremental learning algorithm designed for nonstationary environments where the underlying data distribution changes over time. With each dataset drawn from a new environment, we generate a new classifier. Classifiers are combined through dynamically weighted majority voting, where voting weights are determined based on classifiers? age and accuracy on current and past environments. The most recent and relevant classifiers are weighted higher, allowing the algorithm to appropriately adapt to drifting concepts. This algorithm does not discard prior classifiers, allowing efficient learning of potentially cyclical environments. The algorithm learns incrementally, i.e., without access to previous data. Finally, the algorithm can use any supervised classifier as its base model, including those not normally capable of incremental learning. We present the algorithm and its performance using different base learners in different environments with varying types of drift.
Chromatin Ionic Atmosphere Analyzed by a Mesoscale Electrostatic Approach

Characterizing the ionic distribution around chromatin is important for understanding the electrostatic forces governing chromatin structure and function. Here we develop an electrostatic model to handle multivalent ions and compute the ionic distribution around a mesoscale chromatin model as a function of conformation, number of nucleosome cores, and ionic strength and species using Poisson-Boltzmann theory. This approach enables us to visualize and measure the complex patterns of counterion condensation around chromatin by examining ionic densities, free energies, shielding charges, and correlations of shielding charges around the nucleosome core and various oligonucleosome conformations. We show that: counterions, especially divalent cations, predominantly condense around the nucleosomal and linker DNA, unburied regions of histone tails, and exposed chromatin surfaces; ionic screening is sensitively influenced by local and global conformations, with a wide ranging net nucleosome core screening charge (56–100e); and screening charge correlations reveal conformational flexibility and interactions among chromatin subunits, especially between the histone tails and parental nucleosome cores. These results provide complementary and detailed views of ionic effects on chromatin structure for modest computational resources. The electrostatic model developed here is applicable to other coarse-grained macromolecular complexes.
Mueller Matrix: An Experimental And Analytical Tool For Magneto-Optics

The operation of a photoelastic modulator (PEM) type ellipsometer is described in terms of Mueller matrix elements. The phase shift (5 and the relative amplitude attenuation ratio tan * between orthogonal polarization components are contained in the Mueller matrix elements and can be obtained through combinations of measured matrix elements. A phase shift measurement accuracy of ±0.2° has been obtained without calibration. A computer-controlled implementation is described along with simple algorithms to extract the ellipsometric constants. The Mueller matrix of a magneto-optic (MO) film medium system has been used along with the Mueller matrix for a "leaky" beamsplitter to form the Mueller matrix for an ideal MO read-back system. One of the Stokes parameters is proportional to the differential detection signal commonly used in MO data detection schemes.