cssi/SciSciGPT-SciSciNet huggingface dataset:
Approximation Properties of Laplace-Type Estimators

The Laplace-type estimator (LTE) is a simulation-based alternative to the classical extremum estimator that has gained popularity in applied research. We show that even though the estimator has desirable asymptotic properties, in small samples the point estimate provided by LTE may not necessarily converge to the extremum of the sample objective function. Furthermore, we suggest a simple test to verify if the estimator converges. We illustrate these results by estimating a prototype dynamic stochastic general equilibrium model widely used in macroeconomics research.
3D Commutation-Loop Design Methodology for a Silicon-Carbide Based 15 kW, 380:480 V Matrix Converter with PCB Aluminum Nitride Cooling Inlay

Wide-bandgap devices like silicon-carbide (SiC) MOSFETs and gallium nitride (GaN) HEMTs feature fast switching speed, low switching losses, and higher operating temperatures. However, with the high di/dt and dv/dt slew rates, even small stray inductances and capacitances can lead to greater overvoltages and ringing during switching transients. Therefore, commutation loop parasitics are critical for SiC and GaN implementations. This paper details the theoretical analysis, and finite element analysis (FEA) simulation comparisons of different 3D Printed Circuit Board (PCB) layout strategies developed for a 15 kW SiC three-phase matrix converter. A discussion and evaluation of device cooling methods to increase the power density of the converter is also included, where each method defines specific constraints on the PCB layout design. Specifically, the use of PCB thermal vias and embedded Aluminum Nitride (AlN) ceramic inserts is evaluated. The latter resulting in a total power loop inductance of 22.8 nH, including device parasitics, and a thermal resistance of 2.7 °C/W.
Passive stiffness of fibrotic skeletal muscle in mdx mice relates to collagen architecture.

Key points The amount of fibrotic material in dystrophic mouse muscles relates to contractile function, but not passive function. Collagen fibres in skeletal muscle are associated with increased passive muscle stiffness in fibrotic muscles. The alignment of collagen is independently associated with passive stiffness in dystrophic skeletal muscles. These outcomes demonstrate that collagen architecture rather than collagen content should be a target of anti-fibrotic therapies to treat muscle stiffness. Abstract Fibrosis is prominent in many skeletal muscle pathologies including dystrophies, neurological disorders, cachexia, chronic kidney disease, sarcopenia and metabolic disorders. Fibrosis in muscle is associated with decreased contractile forces and increased passive stiffness that limits joint mobility leading to contractures. However, the assumption that more fibrotic material is directly related to decreased function has not held true. Here we utilize novel measurement of extracellular matrix (ECM) and collagen architecture to relate ECM form to muscle function. We used mdx mice, a model for Duchenne muscular dystrophy that becomes fibrotic, and wildtype mice. In this model, extensor digitorum longus (EDL) muscle was significantly stiffer, but with similar total collagen, while the soleus muscle did not change stiffness, but increased collagen. The stiffness of the EDL was associated with increased collagen crosslinking as determined by collagen solubility. Measurement of ECM alignment using polarized light microscopy showed a robust relationship between stiffness and alignment for wildtype muscle that broke down in mdx muscles. Direct visualization of large collagen fibres with second harmonic generation imaging revealed their relative abundance in stiff muscles. Collagen fibre alignment was linked to stiffness across all muscles investigated and the most significant factor in a multiple linear regression-based model of muscle stiffness from ECM parameters. This work establishes novel characteristics of skeletal muscle ECM architecture and provides evidence for a mechanical function of collagen fibres in muscle. This finding suggests that anti-fibrotic strategies to enhance muscle function and excessive stiffness should target large collagen fibres and their alignment rather than total collagen.
Glia and Orofacial Pain: Progress and Future Directions

Orofacial pain is a universal predicament, afflicting millions of individuals worldwide. Research on the molecular mechanisms of orofacial pain has predominately focused on the role of neurons underlying nociception. However, aside from neural mechanisms, non-neuronal cells, such as Schwann cells and satellite ganglion cells in the peripheral nervous system, and microglia and astrocytes in the central nervous system, are important players in both peripheral and central processing of pain in the orofacial region. This review highlights recent molecular and cellular findings of the glia involvement and glia-neuron interactions in four common orofacial pain conditions such as headache, dental pulp injury, temporomandibular joint dysfunction/inflammation, and head and neck cancer. We will discuss the remaining questions and future directions on glial involvement in these four orofacial pain conditions.
Abstract 1085: PD-L1-mediated resistance to chemotherapy is overcome by an irreversible JNK inhibitor in colorectal cancer cells

Background Colorectal cancers (CRCs) are intrinsically drug resistant tumors with frequent low or absent tumor cell PD-L1 expression. Previously, we reported that PD-L1 depletion in CRC cells can confer chemoresistance. Given that JNK signaling has been implicated in cell survival and drug resistance in CRC cells, we examined the role of JNK and its regulation in chemoresistance in CRC cells with loss of PD-L1. Materials & MethodsHuman CRC cell lines (RKO, DLD1 and HCT15) were utilized and parental and PD-L1 knockout/knockdown cells were generated. Cells were treated with a JNK1-3 inhibitor (JNK-IN-8) alone or combined with a MEK1/2 inhibitor (cobimetinib), CPT-11 or oxaliplatin. Protein/protein interaction was analyzed by immunoprecipitation (IP); protein/RNA interaction was analyzed by RNA IP assay. RNA level and half life were measured by QRT-PCR. Apoptosis was measured by cleaved caspase-3 and quantified by Annexin V labeling using FACS. Colony formation assay was performed. ResultsPD-L1 depletion in CRC cells was shown to enhance JNK activity that was due to reduced mRNA stability of the upstream CYLD deubiquitinase. Since PD-L1 competes with the ribonuclease EXOSC10 for binding to CYLD mRNA, loss of PD-L1 increases the interaction of EXOSC10 and CYLD mRNA resulting in its ribonuclease-mediated degradation and activation of JNK signaling. JNK activation increased BIM phosphorylation at Thr116 that promotes its sequestration by MCL-1 and BCL-2. Notably, a selective and irreversible JNK1-3 inhibitor (JNK-IN-8) reduces BIMThr116 phosphorylation and can release BIM from its sequestration by MCL-1 and BCL-2 to promote apoptosis. Furthermore, use of JNK-IN-8, an MCL-1 antagonist (AZD5991), or their combination in tumor cells lacking PD-L1 is shown to promote apoptosis and reduce long-term clonogenic survival induced by multiple anti-cancer drugs. As confirmation, knockdown of PD-L1 can confer drug resistance in a human colon cancer-derived organoid model that can be reversed by JNK-IN-8. Conclusion Tumor cells with low or absent PD-L1 expression show increased JNK activity that promotes BIM sequestration by MCL-1/BCL-2 to confer multiple drug resistance that can be reversed by a JNK inhibitor. Citation Format: Frank A. Sinicrope, Lei Sun, Arpad Patai, Tara L. Hogenson, Martin E. Fernandez-Zapico, Bo Qin. PD-L1-mediated resistance to chemotherapy is overcome by an irreversible JNK inhibitor in colorectal cancer cells [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2021; 2021 Apr 10-15 and May 17-21. Philadelphia (PA): AACR; Cancer Res 2021;81(13_Suppl):Abstract nr 1085.
The Impacts Of U.S. Right To Work Laws On Wages, Free Riding, And Unionization

This paper uses state fixed effect models and a Synthetic Control design with Current Population Survey (CPS) data to identify the impact of state Right-to-Work (RTW) laws on wages, benefits, and union status among private and public sector workers. Despite a modest effect of RTW laws on wages, results suggest RTW laws differentially affect benefits, proxied by employer health insurance contributions. RTW laws are associated with substantial increases in free riding (40 percent in the private sector and 35 percent in the public sector) and decreases in union membership and coverage in the private sector (20 percent and 16 percent, respectively). A Synthetic Control design for Wisconsin indicates RTW legislation is associated with declines in membership and coverage in the state's public sector (29 percent) and private sector (40 percent). The evidence supports theoretical predictions that RTW laws result in union decline through increased free riding, though effects are sector-dependent.
An Update on Brazilian Trading Companies and Export Credit

Because of its pressing balance-of-payments problems, Brazil has made exportation of manufactured goods a high priority. Since the economics of Brazil's foreign trade is constantly changing, so are the rules and policies governing export activities, including, inter alia, institutions, procedures, financing and incentives. This brief comment depicts an important Brazilian export institution, the "trading company," and summarizes the current status of the "export credit."
Supply Chain Integration and the SCOR Model

The Supply Chain Operations Reference (SCOR) model has been widely adopted in many companies. Anecdotal evidence and trade journals have reported significant improvements after firms have adopted the SCOR model. Although practitioners have been enthusiastic about implementing and using the SCOR model in their operations, the SCOR model has not been empirically validated. The purpose of this study is to empirically validate the SCOR model (i.e., test the structure of the SCOR model). Data from 125 North American manufacturing firms were collected. The results show that the relationships among the supply chain processes in the SCOR model are generally supported. The Plan process has significant positive influence on the Source, Make, and Deliver processes. The Source process has significant positive influence on the Make process and the Make process has significant positive influence on the Deliver process. The Source process mediates the impact of the Plan process on the Make process and the Make process mediates the impact of the Plan process on the Deliver process. The findings provide managers with empirical evidence that the SCOR model is in fact valid.
Randomized Time-Space Tradeoffs for Directed Graph Connectivity

We present a spectrum of randomized time-space tradeoffs for solving directed graph connectivity or STCONN in small space. We use a strategy parameterized by a parameter k that uses k pebbles and performs short random walks of length \(n^{\frac{1}{k}}\) using a probabilistic counter. We use this to get a family of algorithms that ranges between log2 n and log n in space and 2\(^{{\rm log^2}n}\) and n n in running time. Our approach allows us to look at Savitch’s algorithm and the random walk algorithm as two extremes of the same basic divide and conquer strategy.
What’s Wrong with Pink Pearls and Cornrow Braids? Employee Dress Codes and the Semiotic Performance of Race and Gender in the Workplace

American employers frequently impose dress and grooming restrictions on their employees, and courts routinely uphold their decisions to discipline and even fire workers for violating these dress codes. Workplace dress codes thus serve as a focus for contestation over the visual representation and performance of personal identity. The representation and performance of race and gender—two of the core social identities in contemporary American culture—is achieved in part through elaborate semiotic style codes in dress and grooming. The cases discussed in this chapter demonstrate worker resistance to dress codes that force them to perform core identity attributes in ways that contradict their individual sense of identity. By insisting that the performance on the job of identities such as race and gender by their workers is a matter for the employer to determine, courts are asserting the primacy for the workers of their identity as “employees” over their individualized racial and gender identities. Far from being about trivial matters of personal taste or style, conflict between employers and employees over dress codes serves both as an arena for worker resistance to employer assertions of control over the construction and performance of their “true selves” and as a prime site for cultural contests over the meaning and instantiation of race and gender identities more generally in the modern world.
Cu diffusion barrier: Graphene benchmarked to TaN for ultimate interconnect scaling

The advantages of graphene diffusion barrier are studied and benchmarked to the industry-standard barrier material TaN for the first time. Even when the wire width is scaled to 10 nm, the effective resistivity of the Cu interconnect is maintained near the intrinsic value of Cu using a 3 A single layer graphene (SLG) barrier. In the time dependent dielectric breakdown (TDDB) test, 4 nm multi-layer graphene (MLG) gives 6.5X shorter mean time to fail (MTTF) than 4 nm TaN. However, when the barrier thickness is reduced, 3 A single-layer graphene (SLG) gives 3.3X longer MTTF than 2 nm TaN, showing that SLG has better scaling potential. The influences of SLG grain size and various transfer methods are presented for further improving the SLG barrier performance.
RoboCup 2002 Small-Size League Review

The RoboCup challenge, to build soccer playing robots able to compete against the best human soccer players, is a goal well beyond our current levels of robot technology. Our current competition structure, with its various leagues, aims to step towards this goal by focusing on different aspects of the RoboCup problem. In the small-size league, global perception allows us to focus primarily on single and multi-robot control and multi-robot teamwork.
Ca2+-calmodulin tubulin kinase system and its role in mediating the Ca2+ signal in brain.

Publisher Summary Ca 2+ plays a major role in the function of nervous tissue. Calmodulin is a major Ca 2+ receptor protein in brain and other tissues and has been shown to modulate the effects of Ca 2+ on several important enzyme systems. Ca 2+ -calmodulin protein phosphorylation, especially the tubulin kinase system, provides an important mechanism for regulating synaptic activity. Tubulin has been identified as a major substrate for the calmodulin kinase system and this major cytoskeletal protein may provide an important insight into how Ca 2+ dynamically alters synaptic function. The phosphorylation of tubulin by the Ca 2+ kinase results in a marked allosteric alteration in the tubulin molecule resulting in the formation of very stable tubulin aggregates that form microfilaments. Thus, Ca 2+ can produce marked changes in the physicochemical properties of tubulin through the action of the calmodulin tubulin kinase system. This system provides an attractive biochemical model for converting the Ca 2+ signal into molecular change. The evidence for the role of Ca 2+ kinases and specifically the tubulin kinase system in synaptic modulation is discussed in the chapter.
Ebola virus outbreak, updates on current therapeutic strategies

Summary Filoviruses are enveloped negative-sense single-stranded RNA viruses, which include Ebola and Marburg viruses, known to cause hemorrhagic fever in humans with a case fatality of up to 90%. There have been several Ebola virus outbreaks since the first outbreak in the Democratic Republic of Congo in 1976 of which, the recent 2013–2015 epidemic in Guinea, Liberia, and Sierra Leone is the largest in recorded history. Within a few months of the start of the outbreak in December 2013, thousands of infected cases were reported with a significant number of deaths. As of March 2015, according to the Centers for Disease Control and Prevention, there have been nearly 25 000 suspected cases, with 15 000 confirmed by laboratory testing, and over 10 000 deaths. The large number of cases and the high mortality rate, combined with the lack of effective Food and Drug Administration-approved treatments, necessitate the development of potent and safe therapeutic measures to combat the current and future outbreaks. Since the beginning of the outbreak, there have been considerable efforts to develop and characterize protective measures including vaccines and antiviral small molecules, and some have proven effective in vitro and in animal models. Most recently, a cocktail of monoclonal antibodies has been shown to be highly effective in protecting non-human primates from Ebola virus infection. In this review, we will discuss what is known about the nature of the virus, phylogenetic classification, genomic organization and replication, disease transmission, and viral entry and highlight the current approaches and efforts, in the development of therapeutics, to control the outbreak. Copyright © 2015 John Wiley & Sons, Ltd.
Desmopressin, Von Willebrand Factor and Surgery

The synthetic vasopressin analogue desmopressin acetate (DDAVP) can induce a broad spectrum of physiological reactions that have hematological consequences. These include release of tissue plasminogen activator, depletion of plasminogen activator inhibitor, and activation of plasminogen1-3. Also, DDAVP can benefit hemostasis by stimulating the secretion of factor VIII coagulant protein (FVIII: C)/von Willebrand factor (vWF) from endogenous storage sites1. The latter hemostatic property forms the basis for the widespread therapeutic use of DDAVP to treat mild hemophilia and mild von Willebrand’s disease4, 5. DDAVP also benefits hemostasis by an unknown mechanism in many hematological and nonhematological diseases, including congenital and acquired platelet defects6,7-8, and surgical bleeding9,10, where FVIII: C/vWF concentrations are in the normal range.
Increased cytotoxicity and reversal of resistance to cis-diamminedichloro-platinum(II) with entrapment of cis-Bis-neodecanoato-trans-R,R-1,2-diaminocyclohexaneplatinum (II) in multilamellar lipid vesicles.

The role of liposome entrapment in modulating the cytotoxicity of a lipophilic cisplatin derivative was assessed. cis-Bis-neodecanoato-trans-R,R-1,2-diaminocyclohexaneplatinum++ +(II) (NDDP) was tested in suspension (free NDDP) or entrapped in multilamellar vesicles composed of dimyristoylphosphatidyl choline and dimyristoylphosphatidyl glycerol (L-NDDP). Against LoVo colon carcinoma cells sensitive to cisplatin, L-NDDP was two times more cytotoxic in vitro than free NDDP and cisplatin (Do 7 microM for L-NDDP, 15 microM for free NDDP, and 16 microM for cisplatin). Against LoVo cells resistant to a concentration of 3 micrograms/ml of cisplatin, L-NDDP was three times more cytotoxic than free NDDP and cisplatin (Do 14 microM for L-NDDP, 45 microM for free NDDP, and 48 microM for cisplatin). In in vivo studies, free NDDP was less potent and less active than L-NDDP against i.p. L-1210 leukemia (free NDDP, optimum %T/C 148 at a dose of 75 mg/kg; L-NDDP, optimum %T/C 185 at a dose of 25 mg/kg) and i.p. L1210/PDD leukemia (free NDDP, optimum %T/C 128 at a dose of 50 mg/kg on Days 1, 5, and 9; L-NDDP, optimum %T/C 200 at a dose of 12.5 mg/kg on Days 1, 5, and 9). Free NDDP administered i.v. was inactive against liver metastases of M5076 reticulosarcoma (%T/C 102) while L-NDDP showed significant activity (%T/C 140). The single dose i.v. LD50 in mice of free NDDP and L-NDDP were similar (79.4 mg/kg for free NDDP and 64.5 mg/kg for L-NDDP). These studies show that NDDP is a liposome-dependent drug since it can only be satisfactorily formulated in the liposomal form and since the liposomal carrier plays a crucial role in determining its antitumor activity.
Dynamic characteristics and fast load following of 5-kW class tubular solid oxide fuel cell/micro-gas turbine hybrid systems

SUMMARY Combining solid oxide fuel cell and gas turbine (SOFC/GT) system is a promising concept for future clean and efficient power generation. An SOFC/GT system exploits the complementary features of the two power plants, where the GT recuperates the energy in the SOFC exhaust stream and thereby boosts the overall system efficiency. Through model-based transient analysis, however, it is shown that the intricate coupling dynamics make the transient load following very challenging. The purpose of this study is to examine the load-following capability of 5-kW class SOFC/micro-GT hybrid systems in two different configurations: single-shaft and dual-shaft GT designs. An optimal load-following operation scheme, aimed at achieving a proper trade-off between high steady-state efficiency and fast transient response is developed through model-based dynamic analysis and optimization. Simulation results are reported to illustrate the effectiveness of the proposed optimal scheme. Copyright © 2013 John Wiley & Sons, Ltd.
TU‐A‐BRA‐04: Choreographing Couch and Collimator in Volumetric Modulated Arc Therapy

Purpose: The Trilogy® MX (Varian Medical Systems) supports simultaneous motion of the couch, gantry and collimator during volumetric modulated arc therapy (VMAT). This study investigates the feasibility and potential advantages of treating CNStumors using VMAT with such capabilities. Method and Materials: To guide the selection of couch, gantry and collimator trajectories, a score function estimates the geometric overlap between tumor and organs at risk (OAR) for each couch/gantry combination. An initial set of beam trajectory candidates includes couch and gantry combinations, that correspond to minima found in a search of the overlap score map excluding zones of collision and long beam paths through the patient. This set is clustered into multiple continuous arcs subject to mechanical limitations. Following determination of couch/gantry trajectories, a principal component analysis finds the collimator angle at each beam orientation that minimizes residual tumor‐OAR overlap. A purpose‐developed VMAT optimization algorithm determines the optimal MLC position and MU for control points within each arc. A planning study of seven CNS patients compared trajectory VMAT with dynamic gantry, leaf, couch and collimatormotion (Tra‐VMAT), standard non‐coplanar VMAT (Std‐VMAT, no couch/collimator motion within subarcs), and non‐coplanar IMRT plans. Results: Tra‐VMAT yields improved tumor dose conformality, lowered maximum dose to optic nerve, brainstem and chiasm, by 6%, 1.8%, 0.9%, 1.3%, respectively, relative to Std‐VMAT. Tra‐VMAT also yields higher PTV minimum dose, reduced maximum dose to chiasm, optic nerve, and cochlea, and reduced cochlea mean dose, by 4.4%, 1.5%, 6.4%, 10.2%, 8.9%, respectively, relative to IMRT. Tra‐VMAT average beam‐on time is comparable to Std‐VMAT, but significantly (42%) less compared to IMRT.Conclusion: Optimized couch/collimator trajectories can be integrated with VMAT. Trajectory VMAT, with improved mechanical flexibility, results in better dosimetric properties and improved treatment efficiency in the treatment of CNStumors. Conflict of Interest: Sponsered by Varian Medical System
LEARNING BY INSTRUCTION OR SELECTION: IMPLICATIONS FOR PATTERNS OF GEOGRAPHIC VARIATION IN BIRD SONG

Experience can have both instructive and selective effects on vocal development in song birds. Learning by instruction occurs when one male imitates the song of another. Learning by selection occurs when a male chooses one or more songs to retain in his repertoire based on interaction with other individuals. These models of learning make different predictions about the degree of microgeographic variation in song present in wild populations of birds. If males are instructed by their immediate territory neighbors, then the songs of territory neighbors should be more similar than are the songs of non-neighbors. In contrast, if males select a song for retention that was learned elsewhere in the dialect, the songs of neighbors should be no more similar than are the songs of non-neighbors sampled from the same dialect. We compared the songs of males sampled in two sedentary populations and four migratory populations of four subspecies of the white-crowned sparrow, Zonotrichia leucophrys. In the two sedentary nuttalli populations, males on neighboring territories sang very similar songs, indicating that males are instructed by their territory neighbors after they disperse short distances to their breeding territories. Learning by selection during territory establishment after natal dispersal appears to predominate in the four migratory populations: the songs of territory neighbors were no more similar than were the songs of non-neighbors. We conclude that the sedentary/migratory distinction in the annual cycle determines the form of vocal learning that occurs between territory neighbors.
Multivariate analysis of sedimentary environments using grain-size frequency distributions

Multivariate statistics were used to characterize and test the effectiveness of grain-size frequencies as environmental discriminators. Sediment from the following two depositional systems along eastern Lake Michigan were studied: (1) a closed system with respect to available grain sizes (Little Sable Point), and (2) an open system (Sleeping Bear Point-Manitou Passage). Principal components analysis shows that grain-size distributions are composed of two or more subgroups that reflect surface creep bedload, mixed suspension bedload, and uniform suspension. Discriminant function and principal latent vector analyses of the Little Sable Point environments show that, when available sediment is limited with respect to grain size (0.5 φto 3.0 φ), similar size distributions can occur in environments supposedly characterized by different energy conditions. Sediment in the Sleeping Bear Point-Manitou Passage system is not restricted to available grain sizes and the environments discriminated very well (α < 0.001). The grain-size distributions are such that they reflect differences in energy conditions within the environments. It is apparent that the grain sizes available to a depositional system control to a great extent the effectiveness of environmental discrimination.
Adenoviral-mediated expression of functional na+ channel β1 subunits tagged with a yellow fluorescent protein

Voltage-gated sodium (Na(+)) channels typically contain a pore-forming alpha subunit and one or two auxiliary beta subunits. Although initial characterization of known alpha and beta subunits has been facilitated by expression in heterologous cells, to understand fully the differences between individual subunits and the functional consequences of selective subunit expression, there is a need to acutely manipulate expression in cells that endogenously express Na(+) channels. To this end, we have constructed a recombinant adenovirus containing a cDNA for a mouse Na(+) channel beta1 subunit with a yellow fluorescent protein fused to its C-terminus (Ad-beta1-EYFP), and with fluorescence microscopy detected beta1-EYFP expression in primary cerebellar neurons and Chinese hamster ovary (CHO) cells upon transduction with this adenovirus, including expression in the plasma membrane. Consistent with this, patch clamp recordings confirmed that Na(+) currents in CHO cells expressing mouse Na(v)1.4 alpha subunits were appropriately modified by the viral-mediated expression of beta1-EYFP subunits. The results demonstrate that adenoviral-mediated gene delivery can be used effectively to express epitope-tagged Na(+) channel subunits with properties similar to wild-type subunits, and suggest that Ad-beta1-EYFP will be a useful reagent for investigating Na(+) channels in a variety of excitable cell types, including neurons.
Investigation of the flexibility of DNA using transient electric birefringence.

In the preceding article, a Monte Carlo analysis was presented which provides a quantitative numerical relationship between the rotational diffusion coefficients, as measured by the decay of optical anisotropy following an electric field pulse, and the flexibility (persistence length) of short, wormlike chains. In the present article, the results of the foregoing analysis are applied to the observed rates of decay of birefringence for a series of sequenced DNA fragments ranging in size from 104 to 910 base pairs. Under the conditions used in this study, the DNA fragments exist as native, duplex molecules. Furthermore, conditions are defined in which the observed relaxation times are not dependent on DNA concentration, field strength, or the duration of the pulse. It is pointed out that the ionic atmosphere associated with a wormlike polyion does not exert any significant (direct) influence on the rotational diffusion of the polyion and, therefore, that the rotational relaxation times are a true measure of the configurations of the DNA molecules in solution. Moreover, excluded-volume effects are shown not to be significant for the moderately short molecules employed in this study. The major conclusion of this study is that there is no strong ionic strength dependence of the persistence length for ionic strengths above 1 mM and that the persistence length, under conditions where electrostatic contributions are negligible, is approximately 500 A. For ionic strengths significantly lower than 1 mM, electrostatic contributions to the stiffness of DNA become significant.
Off-shell effects in scattering from the deuteron

Abstract A simple model for scattering from a deuteron is studied. Within this model exact coupled channel solutions, including all multiple scattering series terms, are obtained for a fixed separation of the two scattering potentials. These solutions are compared with approximations which involve a spherically averaged or non-overlapping potential. Our results indicate that the non-negligible contributions arising from the overlapping potential region can be adequately reproduced by a combination of simple approximations thereby facilitating calculations of scattering from a more physical deuteron model.
A Lecture/Laboratory Course on Microcomputer-Based Medical Instrumentation

Most existing courses on computers in medicine study applications of minicomputers or large-scale mainframes. These courses typically emphasize data-base management or computer simulation of biological systems. At the University of Wisconsin-Madison, our course has evolved away from these applications and toward design of microcomputer-based medical instrumentation. To support this course, we have developed a textbook on this topic and a set of ten laboratory experiments that give the student hands-on experience with both hardware and software aspects of instrument design.
Phenylalanine alters the mean power frequency of electroencephalograms and plasma L-dopa in treated patients with phenylketonuria.

ABSTRACT: Phenylketonuria is a human model for the study of the effects of phenylalanine on brain function. We found previously a correlation between high blood phenylalanine, prolonged performance times on neuropsychological tests of higher integrative function, and decreased urinary dopamine in 10 patients. In this protocol we examine changes in triplicate of plasma dihydroxyphenylalanine (L-DOPA) and the mean power frequency of the electroencephalogram in eight additional older patients with phenylketonuria using longer intervals in a blinded, cross-over design. Mean power frequency was obtained by Fourier transform of the power spectrum from traditional eight channel electroencephalograms. Plasma L-DOPA was quantitated by radioenzymatic methods. In all patients statistically significant decreases were found in the mean power frequency of the electroencephalogram and in plasma L-DOPA when plasma L-phenylalanine increased. These findings were reversible and correlated in the reverse direction when plasma L-phenylalanine was reduced. Thus changes in the mean power frequency of electroencephalograms and circulating L-DOPA offer sensitive parameters of human brain function in vivo. These findings indicate reversible effects of elevated plasma phenylalanine on electrical function of the brain which may be mediated in part through inhibition of catecholamine synthesis.
If and When Sociology Becomes a Female Preserve

This article investigates recent data on the prevalence of women in the field of sociology in order to understand whether or not the discipline has become a female preserve. Data on the top sociology departments in the USA were collected in 2007. For each university, we document the number of full time, tenured and tenure-track faculty members and present the gendered makeup of the department. Our data present mixed findings with regard to the question of whether the field is tipping toward female. Women, overall, are underrepresented in the sociology programs sampled, but a larger percentage of women occupy tenured positions within the top liberal arts programs than at the top graduate programs. And, women occupy a slim majority of assistant professor positions but have lower numbers at higher academic ranks. We can say with reasonable certainty that, while the proportion of women doctorates and assistant professors indicate a feminization of sociology, the entire discipline has not yet tipped toward female.
Reproduction, feeding activity, and growth in the adult firebrat, Lepismodes inquilinus Newman (Thysanura, Lepismatidae)

Abstract Under optimal conditions, reproduction does not affect the rate of growth in female Lepisodes. In unmated male and female firebrats, an increase of weight after ecdysis is associated with a single phase of feeding activity, which terminates near the middle of the instar, coincident with the reconstruction of the midgut epithelium. In mated females, a greater increase in weight accompanies a more intense first phase of feeding, and at oviposition a short second phase of feeding commences. The weight of food consumed in this second phase is closely correlated with the weight of eggs laid, and evidently compensates for loss of reserves at oviposition.
Dose-dependent down-regulation of ß-adrenoceptors by isoproterenol in rat C6 glioma cells

Nano- and micromolar isoproterenol concentrations were compared by studying cyclic AMP, beta-adrenoceptor density and beta 1-adrenoceptor mRNA in rat C6 glioma cells. 1 microM isoproterenol significantly changed all parameters at 15-30 min. The beta 1-antagonist metoprolol attenuated the response. No effects of nanomolar isoproterenol on these early changes were observed, although the density of beta-adrenoceptors was significantly reduced beginning at 12 h. The results indicate a different process for beta-adrenoceptor desensitization in C6 cells following physiologically low agonist concentrations.
A Experimental Determination of the Velocity of Sound in Dry Carbon-Dioxide - Free Air and Methane at Temperatures Below the Ice-Point

The fixed path acoustic interferometer has been used for the measurement of the velocity of sound in dry C${\mathrm{O}}_{2}$-free air and in methane between 90\ifmmode^\circ\else\textdegree\fi{}K and the ice point. Acoustic resonance in a limited column of gas, coupled to a driven X-cut quartz crystal of fundamental frequency of about 600 kc per sec., is produced by temperature variation. The procedure is such that differences in temperature readings, when the temperature is rising and when it is falling, are reduced to an amount in keeping with the other errors of measurement. No molecular acoustic dispersion has been observed so that the results are made available with especial reference to their value for computations of specific heats. The results are given, within experimental error, by the formulae: for air, ${v}^{2}=3.8762\ifmmode\times\else\texttimes\fi{}{10}^{2}T+806+1.8043\ifmmode\times\else\texttimes\fi{}{10}^{5}{T}^{\ensuremath{-}1}\ensuremath{-}2.0364\ifmmode\times\else\texttimes\fi{}{10}^{7}{T}^{\ensuremath{-}2}+3.007\ifmmode\times\else\texttimes\fi{}{10}^{\ensuremath{-}2}{T}^{2}$ and for methane, ${v}^{2}=6.6176\ifmmode\times\else\texttimes\fi{}{10}^{2}T+1.0016\ifmmode\times\else\texttimes\fi{}{10}^{6}{T}^{\ensuremath{-}1}\ensuremath{-}1.3846\ifmmode\times\else\texttimes\fi{}\ifmmode\times\else\texttimes\fi{}{10}^{8}{T}^{\ensuremath{-}2}$.
The effect of gold sodium thiomalate on copper binding to bovine serum albumin

Abstract Two drugs D-penicillamine and gold sodium thiomalate, used in the treatment of rheumatoid arthritis, removed copper(II) bound to bovine serum albumin as measured by a spectral change of the copper-albumin adduct. Utilizing the esterase activity of serum albumin and its inhibition by copper, it appears that the action of gold sodium thiomalate is indirect: serum albumin first reacted with the drug still bound copper, but addition of more drug did not remove it. Thus, the initial reaction of gold sodium thiomalate with albumin's free sulfhydryl group was required to make the thiomalate ligand available for reaction with copper bound at a different site.
What should students learn about complementary and alternative medicine

With thousands of complementary and alternative medicine (CAM) treatments currently being used in the United States today, it is challenging to design a concise body of CAM content which will fit into already overly full curricula for health care students. The purpose of this article is to outline key principles which 15 National Center for Complementary and Alternative Medicine-funded education programs found useful when developing CAM course-work and selecting CAM content. Three key guiding principles are discussed: teach foundational CAM competencies to give students a framework for learning about CAM; choose specific content on the basis of evidence, demographics and condition (what conditions are most appropriate for CAM therapies?); and finally, provide students with skills for future learning, including where to find reliable information about CAM and how to search the scientific literature and assess the results of CAM research. Most of the programs developed evidence-based guides to help students find reliable CAM resources. The cumulative experiences of the 15 programs have been compiled, and an annotated table outlining the most highly recommended resources about CAM is presented.
The Relative Contributions of Physical Structure and Cell Density to the Antibiotic Susceptibility of Bacteria in Biofilms

For many bacterial infections, noninherited mechanisms of resistance are responsible for extending the term of treatment and in some cases precluding its success. Among the most important of these noninherited mechanisms of resistance is the ability of bacteria to form biofilms. There is compelling evidence that bacteria within biofilms are more refractory to antibiotics than are planktonic cells. Not so clear, however, is the extent to which this resistance can be attributed to the structure of biofilms rather than the physiology and density of bacteria within them. To explore the contribution of the structure of biofilms to resistance in a quantitative way, we developed an assay that compares the antibiotic sensitivity of bacteria in biofilms to cells mechanically released from these structures. Our method, which we apply to Escherichia coli and Staphylococcus aureus each with antibiotics of five classes, controls for the density and physiological state of the treated bacteria. For most of the antibiotics tested, the bacteria in biofilms were no more resistant than the corresponding populations of planktonic cells of similar density. Our results, however, suggest that killing by gentamicin, streptomycin, and colistin is profoundly inhibited by the structure of biofilms; these drugs are substantially more effective in killing bacteria released from biofilms than cells within these structures.
Mechanisms for Metabolism of Ethanol to 1-Hydroxyethyl Radicals in Rat Liver Microsomes

Experiments have been designed to reevaluate mechanisms for metabolism of ethanol to 1-hydroxyethyl radicals (HER) in rat liver microsomes. The variables tested include addition of azide, catalase, superoxide dismutase, and deferoxamine, or use of phosphate or Tris buffers. The results indicate that several mechanisms of HER formation are possible, depending on the experimental conditions used to study this process. In the presence of phosphate buffer, which has been used extensively in spite of its ability to chelate iron, HER formation is quite sensitive to changes in hydrogen peroxide availability. These results suggest that Fenton-type reactions produced the oxidizing intermediate responsible for conversion of ethanol to a free radical in phosphate buffer. However, in Tris buffer, HER formation was inhibited markedly by addition of superoxide dismutase, whereas catalase or azide had little effect. These data indicate that the apparent mechanism of radical formation may be influenced by the choice of buffer used. HER formation was almost abolished by the combination of superoxide dismutase and deferoxamine in both buffers, suggesting little enzymatic HER formation by the cytochrome P450 enzymes. When changes in HER formation were compared with rates of ethanol oxidation, it was inferred that 25 to 50% of the acetaldehyde formed during microsomal ethanol oxidation under different experimental conditions could arise via the HER intermediate.
Microfracture and material removal in scratching of alumina

A bonded-interface sectioning technique is used to examine subsurface damage modes and to identify mechanisms of material removal in repeated single-point scratching of alumina as a function of grain size, load, and number of passes. In the fine grain alumina, the lateral and median crack system is observed, together with intergranular microcracks and intragrain twin/slip bands distributed within the plastic zone. The distributed form of damage, namely twin/slip bands and intergranular microcracks, are also observed in the coarse grain alumina; but no evidence is found for well-defined median and lateral cracks in this material. The mechanism of material removal in alumina is identified as grain dislodgement resulting from grain boundary microcracking, irrespective of the grain size. Extension of lateral cracks is found to contribute to the material removal process only in the fine grain alumina scratched under a large load and after several passes. A model for the microfracture-controlled material removal process is proposed that relates the volume of material removed to the applied load and material properties including grain size, elastic modulus, hardness, and short-crack toughness. Removal rate is shown to be proportional to grain sizeI1/2 and to loadP2. The model and the experimental results obtained in scratching are used to describe the action of an individual abrasive grit in grinding and other abrasive machining processes.
Action Attenuates the Effect of Visibility on Gesture Rates

Much evidence suggests that semantic characteristics of a message (e.g., the extent to which the message evokes thoughts of spatial or motor properties) and social characteristics of a speaking situation (e.g., whether there is a listener who can see the speaker) both influence how much speakers gesture. However, the Gesture as Simulated Action (GSA) framework (Hostetter & Alibali, ) predicts that these effects should not be independent but should interact such that the effect of visibility is lessened when a message evokes strong thoughts of action. This study tested this claim by comparing the gesture rates produced by speakers as they described 24 nouns that vary in how strongly they evoke thoughts of action. Further, half of the words were described with visibility between speaker and listener blocked. The results demonstrated a significant interaction as predicted by the GSA framework. Language: en
Glycoprotein biosynthesis: The characterization of two glycoprotein: Fucosyl transferases in HeLa cells☆☆☆

Abstract Two glycoprotein: fucosyl transferases that transfer fucose from GDP-fucose onto glycoprotein receptors were found in a Triton X-100 extract of HeLa cells. One enzyme, designated the fetuin:fucosyl transferase, utilizes as a receptor fetuin from which sialic acid and galactose were removed, thus leaving an available terminal N -acetylglucosamine residue. This enzyme has an optimum pH of 6.0, temperature optimum of 30 °, and requires Mg 2+ . The other enzyme designated the PSM: fucosyl transferase, utilizes as a receptor PSM from which sialic acid and fucose were removed leaving an available terminal galactose residue. This enzyme has an optimum pH of 6.8, temperature of 37 °, and does not require metal ion activation. Both enzymes showed a high degree of specificity when tested with various glycoprotein receptors. It was concluded that one enzyme was involved in formation of a fucosyl- N -acetylglucosamine linkage, probably 1–4, while the other enzyme recognized only galactose with probable formation of the α- l -fucosyl-(1–2)- O - d -galactose linkage found in blood group substances and porcine submaxillary glycoprotein. The galactose residues of fetuin and α 1 -glycoprotein were relatively inactive as receptors. Approximately 1.1–2.4% of the theoretical receptor sites reacted with GDP-fucose after 24-hr incubation. Both enzymes required macromolecular receptors; several mono- and disaccharides were nonfunctional as receptors. Both enzymes were were found in the smooth internal membranes containing the multienzyme group of glycosyl transferases involved in biosynthesis of the carbohydrate units of membrane glycoproteins. The fucosyl transferases are strongly bound to these membranes; dissociation with the detergent Triton X-100 solubilizes the enzymes. The detergent-solubilized enzymes were purified 11-fold by gel filtration on Sephadex G-200 followed by centrifugation at 300,000 g for 4 hr. The role of the fucosyl enzymes in the mechanism of glycoprotein biosynthesis is discussed. Of special interest in this regard is the synthesis of “artificial” glycoproteins illustrated by the replacement of the β-galactosyl-(1–4)- n -acetylglucosamine linkage present in native fetuin by the fucosyl- N -acetylglucosamine linkage formed with the fetuin:fucosyl transferase.
Introduction to biostatistics: Part 5, statistical inference techniques for hypothesis testing with nonparametric data

Specific statistical tests are used when the null hypothesis (H0) is to be tested using nonparametric nominal or ordinal data. With nominal data, experimental results are expressed by proportions or frequencies. Chi-square or related tests (the Fisher's exact test or the rows by columns test) are appropriate for testing H0 with nominal data. Ordinal data permit arrangement of statistical results by rank. Rank-order tests used to test H0 with ordinal data include the Mann-Whitney U, Kolmogorov-Smirnov, Wilcoxon, Kruskal-Wallis, and Friedman tests. The Kruskal-Wallis and Friedman tests permit multiple intergroup comparisons. Other rank-order tests permit only single intergroup comparisons. Specific details to guide the researcher in the proper selection of these tests are presented.