cssi/SciSciGPT-SciSciNet huggingface dataset:
Ultrasensitive Open-Ended Coaxial Cable-Based Microwave Resonator Learns to Sense Impacts

This article presents an ultrasensitive open-ended hollow coaxial cable resonator (OE-HCCR) that was trained to detect impact events that occurred in the surrounding space through machine learning (ML) techniques. First, inspired by the well-known mass-based accelerometer, for the first time, we propose an OE-HCCR-based accelerometer with the addition of an inertial mass block as the element responsive to acceleration. The OE-HCCR is formed by a metal shorting post welded at the RF input end and the open end of the cable. The instantaneous displacements of the mass block mounted at the endface of the cable due to accelerations lead to variations of the gap distance between the mass block and the endface of the coaxial line, which can be accurately metered by the coaxial resonating structure. Impact events that occur in the surrounding space of the OE-HCCR result in vibrations transmitted to the OE-HCCR system and thereby measured by the OE-HCCR. Second, we demonstrated that employing ML algorithms to analyze the transient responses from the OE-HCCR makes unambiguous mappings between the transient responses of the OE-HCCR and the sources of vibrations possible, due to the ultrahigh sensitivity of the OE-HCCR and the spatial anisotropy of matter in the surrounding space. The preliminary results demonstrate the feasibility of using ML-assisted OE-HCCR system for locating impact events and recognizing different impactor implements that caused the impact events.
Some congenital diseases may just show up later.

Citation:Hurvitz MS, Bhattacharjee R. Some congenital diseases may just show up later. J Clin Sleep Med. 2020;16(11):1835–1836.
Radiosurgery for cerebral dural arteriovenous fistulas

Abstract Intracranial dural arteriovenous fistulas (dAVFs) can be divided into aggressive and nonaggressive subtypes by their presentation and venous outflow. Stereotactic radiosurgery is a minimally invasive treatment option for cerebral dAVF with an excellent safety profile and moderately high eventual obliteration rates for appropriately chosen patients. Radiosurgery is predominantly utilized for cases of nonaggressive dAVF or for patients in whom endovascular or surgical treatment is at an unacceptably high risk; however, the main limitation of radiosurgery is the latency period. This chapter reviews stereotactic radiosurgery for cerebral dAVFs including common indications and considerations.
Systematic Evaluation of Carbon Hosts for High-Energy Rechargeable Lithium-Metal Batteries

Rechargeable lithium (Li)-metal batteries have great potential for high energy and low cost, but poor Li anode stability remains a challenge. Carbon host structures have been widely studied; howeve...
Charge transfer-mediated sensitization of lanthanide dopants by perovskite quantum dots

The electronically isolated f-orbitals of Ln3+ ions endow these species ultranarrow (atom-like) emission with a long lifetime, which are suitable for the optical generation and propagation of spin qubits, even after the coordination inside the semiconductor matrices. To overcome the low extinction coefficient of the Ln3+ ions, indirect sensitization of Ln3+ ions via energy transfer from the perovskite quantum dots (QDs) is performed through partial substitution of the perovskite matrix with Ln3+ ions. Here, we suggest a charge transfer type intermediate is involved in the energy transfer process, rather than utilizing conventional Forster or Dexter energy transfer. By comparing the static and dynamic process of the perovskite QDs doped with seven different Ln3+ species, we find that only Ln3+ species with low Ln2+ formation energy further advances the non-radiative recombination of the QDs’ delocalized charge carriers, which can potentially sensitize the Ln3+ excited states. The formation of the Ln2+ state naturally implies that energy transfer proceeds through sequential electron and hole transfer. The general mechanistic understanding of Ln3+ dopant sensitization opens the door for targeting multiple emission wavelengths by choosing the right combination of host matrices and Ln3+ species.
Dividends Essentially Equivalent to Redemption: The Taxation of Bootstrap Stock Acquisitions

Funding for the sale of an interest in a profitable closely held corporation often comes from two sources: the buyer and the corporation itself. Such a bootstrap stock acquisition may take one of three forms. Two possible forms involve a distribution by a corporation to a selling shareholder: The corporation may either redeem a portion of the selling shareholder's stock or distribute a dividend to the selling shareholder. The redemption or dividend distribution may be in cash, or in other property. A distribution to a selling shareholder may be taxed to a buyer (either a purchaser or a continuing shareholder) as a constructive dividend, on the theory that the buyer purchased all of the seller's stock and then received a dividend distribution from the corporation. The distribution is then treated as part of the amount realized by the seffing shareholder on the sale of stock to the buyer. The distribution may instead be taxed to the selling shareholder as a dividend or as a redemption of a portion of his stock.
Hormone Action in Human Breast Cancer Estrogen Regulation of Specific Proteins

How do estrogens regulate mammary tumor growth and function? Researchers have been pondering this question ever since breast tumor regression was reported in premenopausal patients following oophorectomy (Beatson, 1896). However, systematic exploitation of endocrine ablative surgery did not occur until the 1950s when Huggins and Dao (1954) obtained 38 clinical remissions after performing 100 ovariectomies for palliation of advanced breast cancer. A similar result occurred with adrenalectomy (Huggins and Bergenstal, 1952) and patients responding to this surgery were found to concentrate [3H]hexestrol in their metastases (Folca et al., 1961). Jensen et al. (1967) and Terenius (1968) then observed that the clinical response to endocrine therapy was correlated with specific binding of estradiol by certain human breast tumor biopsy specimens. This observation and the discovery of a high-affinity receptor protein for estradiol in the cytoplasm of target cells (loft and Gorski, 1966) led to the widespread use of an estrogen receptor (ER) assay to identify hormone-responsive breast tumors (McGuire et al., 1975). Subsequent studies have shown that approximately two-thirds of all breast tumor biopsy specimens contain estrogen receptors, and, of these tumors, that about half respond to ablative and additive endocrine therapies (Edwards et al., 1979). Furthermore, ER analysis of the primary tumor can predict response to endocrine therapy if inaccessible metastatic disease develops.
Human immunodeficiency virus reverse transcriptase. Effect of primer length on template-primer binding.

Poly(rA).oligo(dT)n binding to human immunodeficiency virus type-1 reverse transcriptase heterodimer (p66-p51) was primer length-dependent. The estimated Kd for (n = 10-14) was 20-30 nM and for (n = 16-20) was 0.11-0.14 nM. Gel electrophoretic analysis of the patterns of primer extension was consistent with an abrupt change in the Kd between a primer length of 14 and 16 nucleotides. Further, the rate constant for dissociation of the reverse transcriptase-template-primer complex was determined from steady state kinetics and enzyme-template-primer trapping experiments to be independent of primer length. Thus, the abrupt change in Kd was most likely due to a change in the rate constant for formation of the reverse transcriptase-template-primer complex. A similar shift in the Kd for template-primer binding was observed with poly(dA).oligo(dT)n. Reverse transcriptase homodimer (p66) catalyzed the incorporation of dTMP into poly(rA).oligo(dT)n with the same primer length dependence observed for the heterodimer. In contrast, binding of the p51 homodimer to poly(rA).oligo(dT)n was independent of primer length. Thus, the RNase H domain may contribute to reverse transcriptase heterodimer or p66 homodimer binding to template-primers in which the primer length is greater than 14 nucleotides.
Posterior subscapular approach to the brachial plexus

The posterior subscapular approach to the brachial plexus is commonly indicated in patients with neural entrapment (neurogenic thoracic outlet syndrome, especially when associated with a large C7 transverse process or cervical rib) and paraspinal tumors or lacerating injuries involving the spinal nerves close to the spine. This approach is also preferred in patients with previous anterior neck operations and/or morbid obesity. We describe the anatomy and operative technique of this approach, which has been used by the senior author (DGK) for the past 25 years.
The question of sperm DNA fragmentation testing in the male infertility work-up: a response to Professor Lewis' commentary

A response to the Commentary 'Should sperm DNA fragmentation testing be included in the male infertility work-up?' by Professor Sheena Lewis.
Examples of Duality

In 1934, in his book entitled “Hypothese du continu” [35], Sierpinski collected a number of examples of dual propositions (in the restricted sense, since Erdos’s theorem had not yet been proved). Here we shall discuss three of these pairs, in some cases modifying the statement slightly. In each case, the propositions have been proved up to now only with the aid of the continuum hypothesis. Hence the duals follow without loss from the duality principle. Because they depend on the continuum hypothesis, we shall designate them as “propositions” rather than as “theorems.”
An automated data collection system for membrane transport experiments

Abstract This work presents a direct experimental examination of the linear phenomenological flux equations from the thermodynamics of irreversible processes for membrane transport. Results are given which confirm Onsager reciprocity in a NaClH2O—anion exchange membrane system with concentration and hydrostatic pressure differences. Data for isothermal, non-steady-state experiments are collected from a computerized and automated membrane transport apparatus. For the first time, the solvent and solute flux equations are solved simultaneously, and the four phenomenological transport coefficients are obtained from a single experiment using an ellipsoid algorithm for non-linear programming. It appears that the dependence of the L coefficients on the logarithmic mean transmembrane concentration, cse, is more important than the role of the water flux as an indicator of the limit of the linear region for membrane transport processes. Only in those experiments where cse was held nearly constant was Onsager reciprocity obtained.
Duncan V. Louisiana: How Bigotry in the Bayou Led to the Federal Regulation of State Juries

This essay tells the fascinating story of Duncan v. Louisiana, 391 U.S. 145 (1968), the case in which the United States Supreme Court held that the Constitution guaranteed to state defendants the right to a jury trial. The conflict between parish officials and Gary Duncan grew out of the violent response of white residents to school desegregation, and grew into a fight for the rights of minority citizens to secure legal counsel of their choice. The decision also became the focus of one of the most fundamental controversies in constitutional law, a decision in which the justices openly debated how federal guarantees should be applied against the states. The Court's selective incorporation approach in Duncan, hardly controversial now, was an explosive state's rights issue at the time. As Justice Brennan later wrote, it was in Duncan that the Court attempted to explain the theoretical basis for its decisions requiring the states to adhere to certain provisions of the Bill while excluding others. Duncan's holding that the Due Process Clause limits a state's power to deny jury trials was a key element of the Warren Court's expansive efforts to ensure that the criminal process would not be used as a weapon against those struggling to assert their civil rights. Post-Duncan developments, including Blakely v. Washington, are also discussed.
SNiPer: Improved SNP genotype calling for Affymetrix 10K GeneChip microarray data

Background High throughput microarray-based single nucleotide polymorphism (SNP) genotyping has revolutionized the way genome-wide linkage scans and association analyses are performed. One of the key features of the array-based GeneChip® Mapping 10K Array from Affymetrix is the automated SNP calling algorithm. The Affymetrix algorithm was trained on a database of ethnically diverse DNA samples to create SNP call zones that are used as static models to make genotype calls for experimental data. We describe here the implementation of clustering algorithms on large training datasets resulting in improved SNP call rates on the 10K GeneChip.
Mass Near the Sun

I review the dynamical measurements of mass in the solar neighborhood and show that, within I kpc, ∼ 40% is unaccounted for by known stars and gas. I discuss several interpretations of the data including the’ standard model’ where the extra mass is due to a spherical dark halo. I argue that the evidence for a radically different picture of an ultra-flat distribution is at least as compelling as the standard model.
A New Calculus for the Treatment of Optical SystemsII. Proof of Three General Equivalence Theorems

The general theory developed in Part I is used to prove three equivalence theorems about optical systems of the type under discussion. We prove that any optical system which contains only retardation plates and rotators is optically equivalent to a system containing only two plates—one a retardation plate, and the other a rotator. We then prove an exactly analogous theorem for systems containing only partial polarizers and rotators. Finally, it is proved that the most general optical system which contains any number of all three types of plates is optically equivalent to a system containing at most four plates—two retardation plates, one partial polarizer, and one rotator.
The Role of OX40 Ligand Interactions in the Development of the Th2 Response to the Gastrointestinal Nematode Parasite Heligmosomoides polygyrus

In these studies, we examined the effects of OX40 ligand (OX40L) deficiency on the development of Th2 cells during the Th2 immune response to the intestinal nematode parasite Heligmosomoides polygyrus. Elevations in IL-4 production and total and Ag-specific serum IgE levels were partially inhibited during both the primary and memory immune responses to H. polygyrus in OX40L(-/-) mice. The host-protective memory response was compromised in OX40L(-/-) mice, as decreased worm expulsion and increased egg production were observed compared with H. polygyrus-inoculated OX40L(+/+) mice. To further examine the nature of the IL-4 defect during priming, adoptively transferred DO11.10 T cells were analyzed in the context of the H. polygyrus response. Although Ag-specific T cell IL-4 production was reduced in the OX40L(-/-) mice following immunization with OVA peptide plus H. polygyrus, Ag-specific T cell expansion, cell cycle progression, CXCR5 expression, and migration were comparable between OX40L(+/+) and OX40L(-/-) mice inoculated with OVA and H. polygyrus. These studies suggest an important role for OX40/OX40L interactions in specifically promoting IL-4 production, as well as associated IgE elevations, in Th2 responses to H. polygyrus. However, OX40L interactions were not required for serum IgG1 elevations, increases in germinal center formation, and Ag-specific Th2 cell expansion and migration to the B cell zone.
Identification of Bexarotene as a PPAR Antagonist with HDX

The retinoid x receptors (RXRs) are the pharmacological target of Bexarotene, an antineoplastic agent indicated for the treatment of cutaneous T cell lymphoma (CTCL). The RXRs form heterodimers with several nuclear receptors (NRs), including peroxisome proliferator-activated receptor gamma (PPARγ), to regulate target gene expression through cooperative recruitment of transcriptional machinery. Here we have applied hydrogen/deuterium exchange (HDX) mass spectrometry to characterize the effects of Bexarotene on the conformational plasticity of the intact RXRα:PPARγ heterodimer. Interestingly, addition of Bexarotene to PPARγ in the absence of RXRα induced protection from solvent exchange, suggesting direct receptor binding. This observation was confirmed using a competitive binding assay. Furthermore, Bexarotene functioned as a PPARγ antagonist able to alter rosiglitazone induced transactivation in a cell based promoter:reporter transactivation assay. Together these results highlight the complex polypharmacology of lipophilic NR targeted small molecules and the utility of HDX for identifying and characterizing these interactions.
Ultrasonic sensor to characterize wood pulp during refining.

A novel sensor concept has been developed for measuring the consistency, the degree of refining, the water retention value (WRV), and the consistency of wood pulp during the refining process. The measurement time is less than 5 minutes and the sensor can operate in a slip-stream of the process line or as an at-line instrument. The consistency is obtained from a calibration, in which the attenuation of ultrasound through the pulp suspension is measured as a function of the solids weight percentage. The degree of refining and the WRV are determined from settling measurements. The settling of a pulp suspension (consistency less than 0.5 Wt%) is observed, after the mixer that keeps the pulp uniformly distributed is turned off. The attenuation of ultrasound as a function of time is recorded and these data show a peak, after a certain delay, defined as the “peak time.” The degree of refining increases with the peak time, as demonstrated by measuring pulp samples with different degrees of refining. The WRV can be determined using the relative peak time, defined as the ratio T2/T1, where T1 is an initial value of the peak time and T2 is the value after additional refining. This methodmore » offers an additional WRV test for the industry, because the freeness test is not specific for the WRV.« less
Service learning: Where is the emphasis?

Abstract Service learning is a teaching-learning method that is becoming popular, particularly in the community health arena. It helps students "connect the dots" between the areas of study and actual lived experiences, but beyond these findings, results are anecdotal. The ultimate question for faculty who design nursing curricula to consider is the purpose and goal of the service learning component within their program.
Behavioral treatment of chronic insomnia in older adults: does nocturia matter?

Objective To evaluate the impact of nocturia on the therapeutic response of chronic insomnia to behavioral treatment in older adults. Methods Secondary analysis of a randomized clinical trial designed to assess the efficacy of brief behavioral treatment of insomnia (BBTI) vs. an information-only control (IC) in 79 community-dwelling older adults with chronic insomnia. For the current analysis, participants were stratified into 2 groups: those with self-reported nocturia at baseline i.e., ≥ 1 void/night (N = 30; 16 IC, 14 BBTI) and those without nocturia (N = 49; 24 IC, 25 BBTI). We then determined the impact of BBTI on sleep, sleep quality, and nocturia as assessed by self-report, actigraphy, and polysomnography. Results Individuals without baseline nocturia responded well to BBTI with significant decrease in sleep latency, wake after sleep onset, and total sleep time assessed by sleep diary and actigraphy; these changes were significantly greater than those in the IC group. In comparison, changes in the same sleep parameters among participants with nocturia were not significantly different from the IC control. Although BBTI showed significant improvement in sleep quality in groups with and without nocturia (as assessed by PSQI and sleep diary), the effect size of these improvements was larger in those without nocturia than in those with nocturia (PSQI d = 0.82 vs. 0.53, diary sleep quality d = 0.83 vs. 0.51). Conclusions These secondary analyses suggest that brief behavioral treatment of insomnia may be more efficacious in improving insomnia in participants without nocturia. Addressing nocturia may improve the efficacy of behavioral insomnia treatment.
Some effects of pulsed CO2 laser heating of silica

Abstract Silicon dioxide glass (silica) has been irradiated with pulsed multi-mode CO2 laser light at wavelengths at 9.3 and 10.6 μm. These wavelengths fall within the restrahlen bands of silica. Electron paramagentic resonance spectra of irradiated samples contain the E′1 component (singly charged oxygen vacancies) which was not observed prior to irradiation. Dissolving the surfaces of irradiated samples with HF decreases the intensity of the E′1 component. The concentration of E′1 centers decreases with distance from the irradiated surfaces. The profile of concentration versus depth obtained by successive HF etching treatments shows a decrease by a factory of 3 between the surface and a depth of 0.2 μm. a constant concentration to a depth of 1 μm and then a decrease below detectable limits at 2 μm. An approximate calculation of temperature produced by the laser pulse at 9.3 and 10.6 μm shows that temperatures > 2000 K were produced at depths ∼ 0.5 μm. The high concentration of E′1 centers is attributed to the production of oxygen vacancies by high temperatures produced by the laser pulses and the subsequent rapid cooling.
Culture and child welfare: Insights from New Zealand

This article examines child welfare practices under New Zealand’s Children, Young Persons, and Their Families Act of 1989. Insights offered by New Zealand’s experiences fall under four interrelated areas: the recognition of culture, the meaning of family and belonging, partnership with families, and the issues surrounding support and supervision.
Variability of the point spread function in the water column

The Point Spread Function (PSF) is an importantproperty in predicting beam propagation and imaging system performance. An instrument to measure the in situ PSF of ocean water has been built and PSF profiles obtained. This instrument consists of two parts, a flashlamp with cosine emission characteristics, and an imaging solid state camera system. The camera system includes a thermoelectrically cooled CCD array with over 50dB of dynamic range. This allows the camera to measure the steeply peaked PSF over short (lOm) to long (80 m) ranges. Measurements of the PSF in three different locations are presented. One location was a coastal station off San Diego where the water column exhibited a well defmed shallow (approximately 30 meter) mixed layer with a particulate maximum (defined by a maximum in beam attenuation) at the bottom of this layer. During these measurements the PSF was highly variable with depth, as was to be expected due to the dependence of the PSF on particle concentration and size distribution. In the second example the water column was almost homogeneous (as evidenced in the beam attenuation profiles). Hence, the PSF showed very little dependence on depth. Measurements of the variation of the PSF with range are also presented. A simple relationship of the variation of the PSF with angle and optical path length is presented.
An equation of state for square-well and Lennard–Jones fluids based on lattice theory

Abstract Van der Waals theory predicts that the attractive contribution to the compressibility factor is proportional to the inverse of temperature and volume. However, there are deviations from this linear behavior caused by both molecular attractions and molecular repulsions. Here, deviations from linearity due to repulsions are predicted by first order perturbation theory and deviations due to attractions are predicted by an approximate solution to the 3D Ising problem. The close agreement between U/Umean-field for lattice and off-lattice systems is used to derive a new analytic EOS for off-lattice systems which shows very good agreement with simulation data for square-well (SW) and Lennard–Jones (LJ) fluids. While the structures of lattice and off-lattice systems are very different, we show that the non-randomness due to molecular attractions of lattice and off-lattice fluids are fundamentally the same. Because the lattice theory can be generalized to multi-component mixtures without additional assumptions, the model can be extended rigorously to mixtures, i.e., no empirical mixing rules are introduced. The EOS is applied to mixtures of hard-sphere (HS) and square-well (SW) molecules, as well as to SW mixtures with different well depths. The application to highly non-random mixtures of HS and SW mixtures shows very good agreement in internal energy results and fair agreement in compressibility factor calculations. A comparison to the second-order perturbation term for mixtures shows good agreement whereas van der Waals one fluid theory shows large deviations. Second virial coefficients for SW and LJ molecules also are described very accurately with the new approach.
CHRONIC DISEASE OF THE LIVER ASSOCIATED WITH SYSTEMIC SCLERODERMA.

Of 727 patients with systemic scleroderma, 8 had evidence of serious hepatic disease. This low incidence hardly suggests a relationship between the diffuse cutaneous sclerotic process and the chronic hepatic disease, although the association should always be looked for. It is not possible to exclude hepatitis and malnutrition as causative factors of the hepatic disease, although the histologic appearance did not suggest the latter. The hepatic disease usually developed insidiously after years of involvement by the sclerotic process. Similar disease of the liver previously noted in other related diffuse processes, such as lupus erythematosus, and the overlapping of these diffuse processes, particularly as noted in the first case, are further suggestive of a possible etiologic relationship. Special studies of the ascitic fluid in one instance presented some direct evidence to support the concept that hepatic involvement was primary and not secondary to other causes such as cardiac involvement in scleroderma. Finally, it should be emphasized again that postnecrotic cirrhosis is a morphologic and not an etiologic diagnosis and may result from many diverse causes. Careful study of the liver and its function in future instances of diffuse systemic disease such as scleroderma and lupus erythematosus may shed further light on this relationship.
Toxicity of Indian Mustard and Allyl Isothiocyanate to Masked Chafer Beetle Larvae

Abstract Alternatives for control of soil-inhabiting pests are needed due to the phase-out of methyl bromide. One possible alternative is using the pesticidal properties of compounds released by ma...
Lasers in chemistry

Abstract This article reviews the programme of laser research and development being carried out in the Chemistry Division of the US Naval Research Laboratory. It discusses its impact on the overall laser field, particularly in research on chemical lasers, dynamics of laser processes, and laser-promoted chemical reactions. The future direction of laser research and laser applications in the Chemistry Division is outlined and a few specific experiments either under way or planned are described.
Electron microscopy of monomolecular films

SUMMARY Calcium stearate monomolecular films were examined by electron microscopy using replica techniques. The effects of two evaporants, palladium and platinum, on the structure of Langmuir-Blodgett monolayers and multilayers were investigated. The fine structure appears to be altered unless precautions are taken to minimize the radiation heat transfer during the shadow-casting procedure. The structural features of deposited monolayers are also influenced by the underlying solid substrate.
Comparison of nondominant- and dominant-hand performances on the Copy portion of the Rey Complex Figure Test (RCFT)

Road accidents and falls often result in injury to the dominant hand; however, few studies have evaluated whether the use of the nondominant hand confounds pen and paper assessments. This study used a counterbalanced within-subjects design to assess the copy accuracy on the Rey Complex Figure Test (RCFT) of 154 undergraduates using both their right and left hands. Handedness was determined using Briggs and Nebes's (1975) revision of Annett's Handedness Questionnaire. Two independent scorers used objective scoring criteria (Meyers & Meyers, 1995) with high interscorer reliability. Performance differences were statistically but not clinically significant. Nondominant- and dominant-hand performances did not differ from normative data: A total of 78.9% scored above the impairment cutoff score using the nondominant hand compared to 83.7% using their dominant hand. In the event an individual's dominant hand is compromised, performance using the nondominant hand on the RCFT could produce scores within the normat...
Growth chart curves do not describe individual growth biology

Growth reference tables present statistical distributions of size for age of individuals within a sample or population. As summaries of phenotypic variability at the group level, they document that individuals grow by different rates during similar time frames. The data are commonly fitted by mathematical functions to produce the convex curves of percentile distributions useful for infant and childhood growth monitoring. In this form, the growth chart appears to be a frame of reference for judging how well an individual infant/child is progressing through time by comparison with peers across ages. This has led to the assumption that individuals should track in these channels during growth. The interpolated lines between the statistical distributions of size for age at the level of the population do not, however, represent how individuals grow. Growing is an individual process characterized by nonlinear episodic saltatory increments that result in shifting size relationships among similarly aged peers over short time intervals. Data from a prospective, longitudinal study of infants illustrate the poor performance of growth chart curves as representations of individual growth. Clarification of the paradigms supporting perceptions of normal growth patterns is useful both practically and theoretically: growth chart patterns have important clinical sequelae when this informs feeding recommendations. Further characterization of individual growth patterns will contribute to increased understanding of both individual growth biology and the nature of adaptability.
The invasive weed Ventenata dubia is a host of Barley yellow dwarf virus with implications for an endangered grassland habitat

Summary Ventenata dubia (African wiregrass), a winter annual weed, is a non-native species invading grasslands, rangelands and pastures throughout the USA. Limited information is available on its suitability as a host to pathogens and insects in its invaded range. The barley/cereal yellow dwarf virus (B/CYDV) complex occurs ubiquitously in Poaceae species. In non-managed grasslands, BYDV infection influences competitive dynamics between native and invasive grasses and facilitates invasion by non-native annual weeds. The Palouse prairie of south-eastern Washington and northern Idaho, USA, is an endangered ecosystem. Surveys of V. dubia in Palouse prairie and neighbouring Conservation Reserve Program (CRP) habitats were conducted to determine whether B/CYDV viral species are present. Laboratory tests examined the suitability of V. dubia to host BYDV-PAV and serve as an inoculum source. Plant growth and weight parameters were measured to gauge the impact of BYDV-PAV on V. dubia. Infection of V. dubia in Palouse prairie and CRP habitats with two species of BYDV, PAV and SGV, was detected for the first time. The ability of BYDV-PAV to infect V. dubia in the laboratory and transmission from infected V. dubia to barley were demonstrated. BYDV-PAV-infected V. dubia showed reductions in plant height, number of leaves and tillers per plant, and above-ground dry weight, suggesting that V. dubia is sensitive to BYDV. Results demonstrate that V. dubia is a host to BYDV and may serve as a virus inoculum source with potential implications for its management, competitive dynamics between invasive and native grasses and future conservation of endangered grasslands.
Segmented shape memory alloy actuators using hysteresis loop control

A new approach to the design and control of shape memory alloy (SMA) actuators is presented. SMA wires are divided into many segments and their thermal states are controlled individually as a group of finite state machines. Instead of driving a current to the entire SMA wire and controlling the wire length based on the analog strain–temperature characteristics, the new method controls the binary state (hot or cold) of individual segments and thereby the total displacement is proportional to the length of the heated segments, i.e. austenite phase. Although the thermomechanical properties of SMA are highly nonlinear and uncertain with a prominent hysteresis, segmented binary control is robust and stable, providing characteristics similar to a stepping motor. However, the heating and cooling of each segment to its bi-stable states entail longer time and larger energy for transition. In this paper, an efficient method for improving the speed of response and power consumption is developed by exploiting the inherent hysteresis of SMA. Instead of keeping the extreme temperatures continuously, the temperatures return to intermediate 'hold' temperatures closer to room temperature but sufficient to keep constant phase. Coordination of the multitude of segments having independent thermal states allows for faster response with little latency time even for thick SMA wires. Based on stress dependent thermomechanical characteristics, the hold temperature satisfying a given stress margin is obtained. The new control method is implemented using the Peltier effect thermoelectric devices for selective segment-by-segment heating and cooling. Experiments demonstrate the effectiveness of the proposed method.
Cardiac Sarcotubular Vesicles: EFFECTS OF IONS, OUABAIN AND ACETYLSTROPHANTHIDIN

The transport of calcium through the membranes of the sarcoplasmic reticulum plays an important role in the relaxation-contraction cycle of the heart. To study and characterize this system, fragmented sarcotubular vesicles from dog hearts were prepared by ultracentrifugation. The fraction between 15,000 and 40,000 g was partially purified by gradient centrifugation. Calcium accumulation by the vesicles in the presence of ATP, Mg, 45 Ca, and oxalate was studied. The rate of calcium uptake increased with the ATP concentration and was not affected by changes in K or Na concentration nor by substitution of isosmotic amounts of sucrose for 75% of the Na ions. Splitting of ATP was increased upon substitution of sucrose. In aged preparations of vesicles, ouabain or acetylstrophanthidin decreased the rate of their calcium accumulation and partially reversed the inhibition of myofibrillar ATPase by the vesicles. It is suggested that the partial inhibition of calcium uptake increases the concentraton of free calcium, and thus makes more calcium available for contraction of the myofibril.
Does Technology Drive History? The Dilemma of Technological Determinism . Edited by Meritt Roe Smith and Leo Marx. Cambridge, Massachusetts: The MIT Press, 1994. xv, 280 pp. $35 hardbound, $16.95 paperback.

These thirteen essays explore a crucial historical question that has been notoriously hard to pin down: To what extent, and by what means, does a society's technology determine its political, social, economic, and cultural forms?Karl Marx launched the modern debate on determinism with his provocative remark that "the hand-mill gives you society with the feudal lord; the steam-mill, society with the industrial capitalist," and a classic article by Robert Heilbroner (reprinted here) renewed the debate within the context of the history of technology. This book clarifies the debate and carries it forward.Marx's position has become embedded in our culture, in the form of constant reminders as to how our fast-changing technologies will alter our lives. Yet historians who have looked closely at where technologies really come from generally support the proposition that technologies are not autonomous but are social products, susceptible to democratic controls. The issue is crucial for democratic theory. These essays tackle it head-on, offering a deep look at all the shadings of determinism and assessing determinist models in a wide variety of historical contexts.Contributors : Bruce Bimber. Richard W. Bulliet. Robert L. Heilbroner. Thomas P. Hughes. Leo Marx. Thomas J. Misa. Peter C. Perdue. Philip Scranton. Merritt Roe Smith. Michael L. Smith. John M. Staudenmaier. Rosalind Williams.
The Benefits of a Comprehensive, Integrated, and Granular Data System for Community and Technical College Institutional Research.

A comprehensive, integrated, and granular data system provides significant benefits for a state system institutional research office.
Toxicity of Co2+: implications for lateral line studies.

It has been reported that superficial neuromasts, a type of lateral line organ, mediate rheotaxis in fish. These studies used Co2+ at 2 mmol l–1 for 3 h to ablate the entire lateral line system. The recommended concentration is 0.1 mmol l–1. The present study shows that at 2 mmol l–1 Co2+ is highly toxic to blind Mexican cave fish. Fish exposed to this concentration died in less than 17 h, and produced copious mucus. No control fish died. No cobalt treated fish died after 3 h exposure, but cobalt-treated fish swam about their aquaria faster than control fish and tended to swim at the surface. Hence, both survival and behavior were changed by the excessive concentration of Co2+.
Three-dimensional structure of the diphtheria toxin repressor in complex with divalent cation co-repressors

Abstract Background: When Corynebacterium diphtheriae encounters an environment with a low concentration of iron ions, it initiates the synthesis of several virulence factors, including diphtheria toxin. The diphtheria toxin repressor (DtxR) plays a key role in this iron–dependent, global regulatory system and is the prototype for a new family of iron –dependent repressor proteins in Gram-positive bacteria. This study aimed to increase understanding of the general regulatory principles of cation binding to DtxR. Results The crystal structure of dimeric DtxR holo-repressor in complex with different transition metals shows that each subunit comprises an amino-terminal DNA–binding domain, an interface domain (which contains two metal-binding sites) and a third, very flexible carboxy-terminal domain. Each DNA–binding domain contains a helix–turn–helix motif and has a topology which is very similar to catabolite gene activator protein (CAP). Molecular modeling suggests that bound DNA adopts a bent conformation with helices α 3 of DtxR interacting with the major grooves. The two metal-binding sites lie ∼10 A apart. Binding site 2 is positioned at a potential hinge region between the DNA–binding and interface domains. Residues 98–108 appear to be crucial for the functioning of the repressor; these provide four of the ligands of the two metal-binding sites and three residues at the other side of the helix which are at the heart of the dimer interface. Conclusion The crystal structure of the DtxR holo-repressor suggests that the divalent cation co–repressor controls motions of the DNA-binding domain. In this way the metal co–repressor governs the distance between operator recognition elements in the two subunits and, consequently, DNA recognition.
Consistency test of double ionization of helium by photons and charged particles

We have performed a consistency test of recent data for the ratios of cross sections of double to single ionization of helium by photons and by fast charged particles. It is based on a relationship that connects the dipole and nondipole components of cross sections by charged particle impact to photoionization and Compton scattering, respectively. We find the high energy ratio {ital R}{sub {ital Z}} for charged particles to be a sensitive probe of the photoionization data near threshold. Using recent experimental data for photoionization, the asymptotic ratio {ital R}{sub {ital Z}} is found to range from 0.240{percent} to 0.295{percent}, as compared with direct experimental measurement of 0.26{percent}. {copyright} {ital 1996 The American Physical Society.}
Photomechanical Transcutaneous Delivery of Macromolecules

Transcutaneous drug delivery has been the subject of intensive research. In certain situations, rapid transcutaneous delivery is very desirable. A mechanical (stress) pulse generated by a single laser pulse was shown to transiently increase the permeability of the stratum corneum in vivo . The barrier function of the stratum corneum recovers within minutes. The increased permeability during these few minutes allows macromolecules to diffuse through the stratum corneum into the viable epidermis and dermis. Macromolecules (40 kDa dextran and 20 nm latex particles) were deposited into the skin using a photomechanical pulse generated by a single 23 ns laser pulse. This treatment can potentially be utilized in therapies that currently require occlusive dressings for hours or day(s).
Dynamic Performance and Modular Design of Redundant Macro-/Minimanipulators

This paper presents methodologies for the analysis and design of redundant manipulators, especially macro-/ministructures, for improved dynamic performance. Herein, the dynamic performance of a redundant manipulator is characterized by the end-effector inertial and acceleration properties. The belted inertia ellipsoid is used to characterize inertial properties, and the recently developed dynamic capability equations are used to analyze acceleration capability. The approach followed here is to design the ministructure to achieve the task performance and then to design the macrostructure to support and complement the ministructure, referred to here as modular design. The methodology is illustrated in the design of a six-degree-of-freedom planar manipulator.
Soleus H-reflex phase-dependent modulation during one-legged foot reaching and withdrawal in standing humans

The aim of this study was to establish the modulation pattern of the soleus H-reflex and excitability changes of interneurones mediating presynaptic inhibition from tibialis anterior to soleus Ia afferents when the right foot approached and withdrew from a step in standing humans. The task was conducted at 40 beats per minute, and this tempo corresponded to the rhythm of a half full movement cycle. Each subject was instructed not to load and not to move forward. Soleus H-reflexes were elicited once in every full movement cycle that lasted approximately 3s. The ipsilateral knee joint angle and activity of leg muscles were recorded through a twin-axis goniometer and surface EMG, respectively. In all subjects, the soleus H-reflex was modulated in a phase-dependent pattern. The H-reflex was significantly depressed during the approach phase of the motor task and when the foot was on the step, and facilitated during the withdrawal phase and when the foot was on the ground. The soleus H-reflex conditioned by common peroneal nerve stimulation at tibialis anterior motor threshold at a long conditioning test interval was increased during the withdrawal phase or while the foot was on the ground suggesting that presynaptic inhibition was decreased. In most subjects, knee extensor activity was small, while ankle flexors and extensors were active in a reciprocal pattern. This study provides evidence that the soleus H-reflex is modulated in a phasic pattern during one-legged foot reaching and withdrawal by changes occurring at a premotoneuronal level.
Cropping intensity enhances soil organic carbon and nitrogen in a no-till agroecosystem.

Soil organic C (SOC) has decreased under cultivated wheat (Triticum aestivum)-fallow (WF) in the central Great Plains. We evaluated the effect of no-till systems of WF, wheat-corn (Zea Mays)-fallow (WCF), wheat-corn-millet (Panicum miliaceum)-fallow, continuous cropping (CC) without monoculture, and perennial grass (G) on SOC and total N (TN) levels after 12 yr at three eastern Colorado locations. Locations have long-term precipitation averages of 420 mm but increase in potential evapotranspiration (PET) going from north to south. Within each PET location, cropping systems were imposed across a topographic sequence of summit, sideslope, and toeslope. Cropping intensity, slope position, and PET gradient (location) independently impacted SOC and TN to a 5-cm soil depth. Continuous cropping had 35 and 17% more SOC and TN, respectively, than the WF system. Cropping intensity still impacted SOC and TN when summed to 10 cm with CC > than WF. Soil organic C and TN increased 20% in the CC system compared with WF in the 0- to 10-cm depth. The greatest impact was found in the 0- to 2.5-cm layer, and decreased with depth. Soil organic C and TN levels at the high PET site were 50% less than at the low and medium PET sites, and toeslope soils were 30% greater than summit and sideslopes. Annualized stover biomass explained 80% of the variation in SOC and TN in the 0- to 10-cm soil profile. Cropping systems that eliminate summer fallowing are maximizing the amount of SOC and TN sequestered.