cssi/SciSciGPT-SciSciNet huggingface dataset:
Science in and for space

Space technology has not changed the fundamental character of scientific development, but it has created many demands on science and has hastened many investigations that otherwise might not receive prompt attention A great deal is being said these days about the “impact” of space exploration on science. “Impact” is a harsh word, which perhaps explains the extent to which it has become fashionable in these harsh times. I have not consulted my dictionary because, having driven an automobile in heavy traffic for many years, I have direct physical experience with the word. I know what it means. In fact, all of us who have followed the accounts of the embryonic stages of lunar exploration in the form of the Ranger series obviously know what the commentator meant when he triumphantly shouted “Impact!” after an exciting sequence of pictures closer and closer to the surface of the moon.
The Obligate Mutualist Wigglesworthia glossinidia Influences Reproduction, Digestion, and Immunity Processes of Its Host, the Tsetse Fly

Tsetse flies (Diptera: Glossinidae) are vectors for trypanosome parasites, the agents of the deadly sleeping sickness disease in Africa. Tsetse also harbor two maternally transmitted enteric mutualist endosymbionts: the primary intracellular obligate Wigglesworthia glossinidia and the secondary commensal Sodalis glossinidius. Both endosymbionts are transmitted to the intrauterine progeny through the milk gland secretions of the viviparous female. We administered various antibiotics either continuously by per os supplementation of the host blood meal diet or discretely by hemocoelic injections into fertile females in an effort to selectively eliminate the symbionts to study their individual functions. A symbiont-specific PCR amplification assay and fluorescence in situ hybridization analysis were used to evaluate symbiont infection outcomes. Tetracycline and rifampin treatments eliminated all tsetse symbionts but reduced the fecundity of the treated females. Ampicillin treatments did not affect the intracellular Wigglesworthia localized in the bacteriome organ and retained female fecundity. The resulting progeny of ampicillin-treated females, however, lacked Wigglesworthia but still harbored the commensal Sodalis. Our results confirm the presence of two physiologically distinct Wigglesworthia populations: the bacteriome-localized Wigglesworthia involved with nutritional symbiosis and free-living Wigglesworthia in the milk gland organ responsible for maternal transmission to the progeny. We evaluated the reproductive fitness, longevity, digestion, and vectorial competence of flies that were devoid of Wigglesworthia. The absence of Wigglesworthia completely abolished the fertility of females but not that of males. Both the male and female Wigglesworthia-free adult progeny displayed longevity costs and were significantly compromised in their blood meal digestion ability. Finally, while the vectorial competence of the young newly hatched adults without Wigglesworthia was comparable to that of their wild-type counterparts, older flies displayed higher susceptibility to trypanosome infections, indicating a role for the mutualistic symbiosis in host immunobiology. The ability to rear adult tsetse that lack the obligate Wigglesworthia endosymbionts will now enable functional investigations into this ancient symbiosis.
Hippocampal Physiology, Structure and Function and the Neuroscience of Schizophrenia: A Unified Account of Declarative Memory Deficits, Working Memory Deficits and Schizophrenic Symptoms

Memory impairment is a consistent feature of the schizophrenic syndrome. Hippocampal dysfunction has also been consistently demonstrated. This review will discuss neurophysiological and neuroanatomical aspects of memory formation and how they relate to memory impairment in schizophrenia. An understanding of the cellular physiology and connectivity of the hippocampus with other regions can also aid in understanding the relationship between schizophrenic declarative or relational memory deficits, working memory deficits and the clinical symptoms of the syndrome.
HALE STAIN FOR SIALIC ACID-CONTAINING MUCINS : Adaptation to Electron Microscopy

The feasibility of using the Hale stain to identify cellular sialic acid-containing mucins by electron microscopy was investigated. Three kinds of mouse ascites tumor cells were fixed in neutral buffered formalin, exposed to fresh colloidal ferric oxide, treated with potassium ferrocyanide, imbedded in Selectron, and sectioned for electron microscopy. Additional staining with uranyl acetate and potassium permanganate was done after sectioning in order to increase contrast. Those cells known to be coated with sialomucin showed deposits of electron-opaque ferric ferrocyanide crystals in the areas where sialomucin concentrations were expected. When these cells were treated with neuraminidase beforehand, these deposits did not appear. It was concluded that, with the precautions and modifications described, the Hale stain can be successfully combined with electron microscopy to identify sialomucin.
Integrated ethanol production and utilization system for small farms

Abstract Small on-farm ethanol production and utilization systems can be improved to the point of energy and economic feasibility. Test runs have been made utilizing a wood gasifier to provide the heat for both cooking and distillation. A 70% reduction in energy cost is obtained when compared with fossil fuels. Improvements in fermentation procedures with corn gave ethanol concentrations of 9–10% (wv −1 ) in 48 h. Even higher concentrations (12–13% wv −1 ) can be obtained with waste type supplements to the corn, with only slight increases (12–24 h) in fermentation times.
Cancer: The complex seeds of metastasis

Analyses of prostate-cancer metastases reveal a complex cellular architecture, and show that secondary sites can be seeded by multiple cell populations derived from both the primary tumour and other metastases. See Letter p.353 Gunes Gundem et al. have mapped the subclonal composition of human prostate tumours and their metastases, thus establishing the evolutionary history behind the development and spread of these cancers. Importantly, they find that metastases could be re-seeded multiple times, and spread from one site of metastasis to another was frequently seen. This work sheds new light on the origin of the vast diversity of genetic and epigenetic alterations that can be seen within tumours and between primary tumours and metastases, and illustrates the clinical challenge of cancer therapy with targeted drugs.
Dissociation constant measurement using combination tapered fiber-optic biosensor (CTFOB) dip-probes.

The document reports a novel method of measuring dissociation constant ( k D ) of antibody-antigen interaction using evanescent wave based combination tapered fiber-optic biosensor (CTFOB) dip-probes. The method was demonstrated by measuring the dissociation constant of human Interleukin-6 (IL-6) and anti-IL-6 interaction. Sandwich immunoassay was used to generate fluorescence signal proportional to antigen-antibody conjugate pairs. A portable CCD based spectrometer setup was used to record spectral profile of the fluorescence signal. The measured value of dissociation constant k D for IL-6 and capture anti-IL-6 (clone MQ2-13A5) antibodies at room temperature is588 ±19 pM .
Converging lower bounds to the photonic bandgap edges

A photonic band gap is determined by its boundaries, which are frequently computed by the Rayleigh-Ritz method, with the plane wave or the finite element basis functions. This method produces a sequence of upper bounds. Since there are no error estimates available on these approximations, the extent of the band gap is not accurately determined, particularly as this method is also known to suffer from a poor rate of convergence for the cases of interest. We adopt the method of intermediate problems to develop a procedure to calculate the lower bounds to the photonic band gap edges. The lower and the upper bounds supplement each other to determine a band gap with arbitrary accuracy, which is essential for designing the photonic band gap material. Computation of the lower bounds requires only slightly more effort than the upper bounds to produce the approximations with comparable accuracy. An alternative method to determine upper bounds is also developed in the process.
Navier-Stokes computations for circulation controlled airfoils

Navier-Stokes computations of subsonic to transonic flow past airfoils with augmented lift due to rearward jet blowing over a curved trailing edge are presented. The approach uses a spiral grid topology. Solutions are obtained using a Navier-Stokes code which employs an implicit finite difference method, an algebraic turbulence model, and developments which improve stability, convergence, and accuracy. Results are compared against experiments for no jet blowing and moderate jet pressures and demonstrate the capability to compute these complicated flows.
Entry in Local Telecommunication Markets

In this paper, we explore the determinants of recent entry into local exchange service, and the role that regulatory policies have had in aiding this policy objective. Our results suggest that the 1996 Telecommunications Act did lead to some entry, but that strategic non-price behavior by incumbents may have offset this impact to some extent. We also find that regulatory policies and market fundamentals play an important role in determining entry. Clearly, market size (measured in various ways) is an important determinant of entry, while there is empirical support for the role of more flexible regulatory mechanisms in promoting new entry.
Hybrid Male Sterility in Crosses Between Field and Laboratory Strains of Anopheles quadrimaculatus (Say) (Diptera: Culicidae)

Hybridization experiments involving matings between nine geographic strains and a laboratory strain (ORL) of Anopheles quadrimaculatus (Say) revealed the existence of two genetically distinct forms of this species. Matings between some individuals (designated type A) of each of the geographic strains produced normal, fertile progeny. However, a second type (designated type B), which was genetically incompatible to the ORL strain, was found in three natural populations. Crosses between type B males and ORL females resulted in high mortality of male progeny in the pupal stage, and all surviving adult male progeny were sterile. The reciprocal cross produced a normal 1:1 sex ratio, and all of the hybrid male progeny were sterile. Female progeny of type B × ORL matings (in both directions) were semisterile. Hybrid females, when backcrossed to either type A or type B males, produced egg batches with lower percent hatch than in the F1 crosses. Male sterility persisted in the backcross progeny. It is concluded, on the basis of mating compatibility to the ORL strain, that type A and type B individuals are genetically incompatible and that populations of each type are reproductively isolated. Samples of adult males collected from two of the three sites were found to be fertile, suggesting that hybridization in nature occurs rarely, if at all. These results and the results of concurrent studies on allozymes and chromosomes led to the conclusion that type A and type B represent sympatrically occurring sibling species, tentatively designated A. quadrimaculatus species A and A. quadrimaculatus species B.
Synthesis, characterization and reactivity of crown ether adducts of barium carboxylates: Ba(O2CCH3)2(18-crown-6)·4H2O and Ba(O2C(CH2)4CO2)(18-crown-6)·8H2O

Abstract The compounds Ba(O2CCH3)2(18-crown-6)·nH2O and Ba(O2C(CH2)4CO2)(18-crown-6)·nH2O were prepared by the reaction between barium carbonate and the appropriate organic acid in the presence of 18-crown-6. These compounds were characterized by a variety of spectroscopic and analytical methods which showed that various hydrates could be formed. The species Ba(O2CCH3)2(18-crown-6)·4H2O(1) and Ba(O2C(CH2)4CO2) (18-crown-6)·8H2O (2) were structurally characterized by single-crystal X-ray diffraction. In the solid state compound 1 was comprised of a Ba atom in the center of the 18-crown-6 ring with chelating acetate ligands being in the axial positions of the equitorial coordination plane. Water molecules were hydrogen bonded to the oxygen atoms of the acetate ligands. Compound 2 is an infinite polymer in the solid state with the Ba atom also in the center of the 18-crown-6 ring with each carboxylate group chelating to one Ba and each adipate bridging through the second carboxylate group of the dicarboxylate to another Ba atom. Compound 1 crystallizes in the monoclinic space group P21/c with cell dimensions of a = 9.512(1) A , b = 7.811(1) A , c = 16.906(1) A , s = 99.049(8)°, V = 1240.5(3) A 3 and Z = 2 . Compound 2 crystallizes in the triclinic space group P 1 with cell dimensions of a = 8.525(1) A , b = 9.769(1) A , c = 10.200(1) A , α = 106.59(1)°, s = 90.37(1)°, γ = 110.34(1)°, V = 757.4(1) A 3 and Z = 1 . Compounds 1 and 2 thermally decompose to evolve the 18-crown-6 ligand intact at approximately 200°C, prior to the thermal decomposition of the carboxylate ligand to form BaCO3. Compounds 1 or 2 were mixed with Ti(O-i-Pr)4 in ethanol, spin coated onto Pt substrates and heated to 400°C followed by annealing at 700°C for 1 h in air. Coumpound 1 resulted in formation of a mixture of BaTiO3, BaCO3 and TiO2, while 2 produced only BaCO3 films. The difference in reactivity of 1 and 2 may be connected to the availability of a thermal window for ester elimination as indicated by the TGA results.
SU-FF-T-299: Validation of a Monte Carlo Algorithm for Simulation of Dispersion Due to Scattering of a Monoenergetic Proton Beam

Purpose: A multi-leaf collimator is being designed as part of a collaborative effort to build a regional protontherapy facility. The Monte Carlo framework GEANT4 has been chosen to assist in this design by simulating the effects of changing the width of the leaves as well as the distance to the patient. The present work focuses on the validation of the current algorithm by comparing the range of the proton beam and lateral penumbra it produces with published data. Method and Materials: Several experimental setups have been simulated according to the data currently available for comparison. All configurations include a monoenergetic beam and a right-angled water parallelepiped where the deposited energy is sampled. We report here the specific results obtained from a variety of independent setups including a pencil beam and a 5 cm by 5 cm square beam. The proton ranges obtained for different energies are compared to tabulated ICRU values. Parameters associated with the multiple scattering dispersion of the beam are compared to published experimental data. In addition to that we compare lateral penumbra results obtained in a more realistic beam line configuration to experimental data published by the Orsay Center for Protontherapy. Results: The proton ranges produced agree with the ICRU values for all simulated energies. The level of reproducibility of multiple scattering effects for all the different beam profiles is adequate when compared to reference values published by Szymaowski et al. The lateral penumbra produced by our beam line simulation satisfactorily corresponds to the behavior described by Oozeer et al. Conclusion: GEANT4 is a promising tool for assisting in the design of the MLC. Our implementations reproduce to the extent presently needed, not only proton ranges but also multiple scattering and lateral penumbra effects.
PRESSURE-INDUCED DEFORMATION OF THE CYTOCHROME P450CAM ACTIVE SITE

The reaction of cytochrome P450cam with aryldiazenes (ArNNH) yields σ-bonded iron−aryl (Fe−aryl) complexes. Oxidation of the complexes causes regioselective migration of the aryl group from the iron to the porphyrin nitrogens. The influence of high pressure on the formation and rearrangement of the Fe−aryl complexes is reported here. The natural logarithm of the rate of formation of the Fe−phenyl complex decreases linearly with pressure with a volume of activation of 38.2 mL mol-1. The Fe−phenyl, Fe−(2-naphthyl), and Fe−(p-biphenyl) complexes are stable at atmospheric pressure but decompose in a pressure-dependent manner at pressures above 1500 (Fe−phenyl) or 2500 bar (Fe−(2-naphthyl) or Fe−(p-biphenyl)). This pressure-induced decomposition results in formation of the N-arylprotoporphyrin IX adducts. The N-aryl porphyrin regioisomer patterns obtained by pressure-induced migration of the aryl groups (NB:NA:NC:ND, Ph, 10:14:33:43; 2-naphthyl, 12:13:37:38; p-biphenyl, 15:15:33:37) differ from those obtained ...
Prostate Brachytherapy: The “Can't Miss” Approach for Patients Undergoing Definitive Radiation for Prostate Cancer?

In this issue, Williams et al (1) publish their single-institution experience comparing biochemical outcomes in intermediateand high-risk prostate cancer patients based on whether they received 3-dimensional conformal external beam radiation therapy (EBRT) alone versus a combination of external beam radiation therapy to the prostate and seminal vesicles together with a highdose-rate (HDR) brachytherapy boost. With a median follow-up time of just over 5 years, they were able to demonstrate improved biochemical control for those patients who received HDR brachytherapy as a component of their treatment (5-year rates: 79.8% vs 70.9%, P< .01). The detected benefits in this analysis were largely attributed to the high biologic equivalent dose (BED) achieved with the large individual fraction sizes delivered with HDR brachytherapy. In this study, a relatively modest (by HDR criteria) hypofractionation scheme of 19.5 Gy delivered in 3 treatment fractions separated by a minimum of 6 hours was used. Certainly, more aggressive HDR dosing regimens have been used with significantly higher BEDs than are reported in this analysis (2, 3). But numeric dose, fractionation schedules, and alpha-beta ratios are not the only factors involved when outcomes between EBRT and brachytherapy are compared. Comparisons predicated on biologic interactions of dose with target tissues are entirely reliant on the assumption that the target tissues, in fact, receive the prescribed dose. Uncertainty and variability in daily prostate anatomy has been well documented (4, 5) and forms the basis for the now widespread practice of image guided radiation therapy (IGRT). The argument in favor of using complex IGRT techniques is that the increased confidence and accuracy in dose delivery results in decreased volumes of adjacent rectum and bladder exposed to doses likely to cause toxicity or long-term complications. This allows for safe dose escalation to the prostate. Although multiple
Trypanosoma cruzi: ability of T-cell-enriched and -depleted lymphocyte populations to passively protect mice.

Abstract T-Cells and a T-cell-depleted population were prepared from the spleens of C3H mice immunized with epimastigotes of the Brazil strain of Trypanosoma cruzi. Both populations of cells, as well as unfractionated spleen cells, were capable of reducing parasitemias and protecting against death when transferred to susceptible C3H mice 24 hr before challenge with 104 Brazil strain trypomastigotes. The immune T-cell-depleted subpopulation was, on an equal cell basis, more effective in engendering resistance than the immune T-cell subpopulation. Protection could also be transferred with unfractionated immune spleen cells if the cells were given within 8 days following challenge of recipient mice. Transfer after 8 days led to significantly reduced parasitemias but all mice died.
Differences in vaginal microbiome in African American women versus women of European ancestry

Women of European ancestry are more likely to harbour a Lactobacillus-dominated microbiome, whereas African American women are more likely to exhibit a diverse microbial profile. African American women are also twice as likely to be diagnosed with bacterial vaginosis and are twice as likely to experience preterm birth. The objective of this study was to further characterize and contrast the vaginal microbial profiles in African American versus European ancestry women. Through the Vaginal Human Microbiome Project at Virginia Commonwealth University, 16S rRNA gene sequence analysis was used to compare the microbiomes of vaginal samples from 1268 African American women and 416 women of European ancestry. The results confirmed significant differences in the vaginal microbiomes of the two groups and identified several taxa relevant to these differences. Major community types were dominated by Gardnerella vaginalis and the uncultivated bacterial vaginosis-associated bacterium-1 (BVAB1) that were common among African Americans. Moreover, the prevalence of multiple bacterial taxa that are associated with microbial invasion of the amniotic cavity and preterm birth, including Mycoplasma, Gardnerella, Prevotella and Sneathia, differed between the two ethnic groups. We investigated the contributions of intrinsic and extrinsic factors, including pregnancy, body mass index, diet, smoking and alcohol use, number of sexual partners, and household income, to vaginal community composition. Ethnicity, pregnancy and alcohol use correlated significantly with the relative abundance of bacterial vaginosis-associated species. Trends between microbial profiles and smoking and number of sexual partners were observed; however, these associations were not statistically significant. These results support and extend previous findings that there are significant differences in the vaginal microbiome related to ethnicity and demonstrate that these differences are pronounced even in healthy women.
Percivall Pott: Tuberculous spondylitis

Abstract Tuberculous spondylitis, also known as Pott's disease, is an entity that produces a characteristic kyphotic deformity, and was described by Sir Percivall Pott in 1779 and 1782. The majority of his patients were infants and young children. Although the incidence of tuberculosis in the industrialized world has since declined dramatically, the number of cases of extrapulmonary disease, though small, has remained relatively unchanged. In developing countries, spondylitis is still generally a disease of children, but in Europe and North America, it more commonly involves older adults. Pott's spondylitis represents a reactivation of latent disease, frequently years after the initial infection. Clinical findings include complaints of back pain and symptoms of fever, chills, weight loss, malaise, and fatigue. Characteristically a late finding, paraplegia is occasionally the initial indicator of spinal involvement. There is an average delay of a year between the onset of symptoms and patient presentation. Plain spinal radiographs usually are the initial diagnostic modality utilized. Computed tomography scanning and magnetic resonance imaging can be used to further define the process. The differential diagnosis includes neoplasm, pyogenic or disseminated fungal infection, and sarcoid arthritis.
PROGONADOTROPIC SERA OF ANIMALS TREATED WITH HYPOPHYSEAL EXTRACTS

IN 1936 WE (1, 2) reported that the serum obtained from rats which had been treated with chronic implantation of pituitaries of the same species, enhanced the gonadotropic action of such hypohyses when both were ad′ ministered subcutaneously in separate sites to immature female rats. The serum of normal rats did not produce this effect and the experimental serum alone did not induce gonadal stimulation. Augmentative activity was also induced in the serum of rats treated with an extract of rat pituitaries in place of the implants (3) Subsequent to our first report, Collip (4) and Rowlands (5) have reported that the serum of sheep treated with sheep pituitary extract exhibits an enhancing effect on the gonadotropic action of this extract in immature female rats. The latter investigator found, as we had found with the rat serum, that the serum of the treated sheep possessed
Innominate artery occlusive disease: management with central reconstructive techniques.

Abstract Background. The purpose of this study was to review our experience with central vascular reconstruction for innominate artery occlusive disease. Eighteen patients underwent central reconstruction for innominate artery (IA) occlusive disease during an 8-year period (1986 to 1994). Mean age was 59 years (range, 36 to 77 years). Women outnumbered men 12 to 6. All patients had symptoms including amaurosis fugax 55%, transient ischemic attacks 44%, vertebrobasilar insufficiency 44%, and arm claudication 33%. The IA was occluded in three patients and stenotic in 15. Three patients underwent previous extrathoracic bypass procedures for IA lesions that failed. Methods. Operations performed through a median sternotomy included aortocarotid bypass with reimplantation of the subclavian (n = 10) and aortoinnominate bypass (n = 7). Transection and oversewing of the IA was performed in all but one patient, in whom ligation of the IA was performed. One patient with severe chronic obstructive pulmonary disease and previous coronary artery bypass grafting underwent retrograde-transluminal IA angioplasty with endovascular stent placement via a carotid approach. Four patients underwent concomitant carotid endarterectomy. Two patients underwent concomitant coronary artery bypass grafting at the time of IA reconstruction. Results. There was one operative death from myocardial infarction. Perioperative morbidity included dysrrhythmia (three), respiratory insufficiency (three), subendocardial myocardial infarction (two), cerebrovascular accident with complete recovery (two), hemorrhage (one), and acute graft occlusion (one). All grafts remained patent at a mean follow-up of 21 months (range, 8 to 60 months). The only patient who underwent ligation of the IA required a subsequent revision of the IA to transection and oversewing for an embolic event at 4 months status-post aortocarotid bypass. The patient who underwent angioplasty remained asymptomatic with a patent IA at 12 months. Average length of stay for transthoracic repair was 14 days and for transluminal angioplasty 2 days. Conclusions. Innominate artery bypass based on the ascending aorta is effective in providing relief of symptoms and has a high patency rate. Because of the significant morbidity, these procedures should be reserved for patients with symptoms. The IA should be transected and oversewn to prevent recurrent embolism. Transcarotid, retrograde angioplasty provides an alternative approach to stenotic lesions located in the IA or proximal common carotid artery. An aggressive approach directed at defining coronary artery disease is an invaluable adjunct to the proper treatment of this patient population.
MIM and Cortactin Antagonism Regulates Ciliogenesis and Hedgehog Signaling

The primary cilium is critical for transducing Sonic hedgehog (Shh) signaling, but the mechanisms of its transient assembly are poorly understood. Previously we showed that the actin regulatory protein Missing-in-Metastasis (MIM) regulates Shh signaling, but the nature of MIM's role was unknown. Here we show that MIM is required at the basal body of mesenchymal cells for cilia maintenance, Shh responsiveness, and de novo hair follicle formation. MIM knockdown results in increased Src kinase activity and subsequent hyperphosphorylation of the actin regulator Cortactin. Importantly, inhibition of Src or depletion of Cortactin compensates for the cilia defect in MIM knockdown cells, whereas overexpression of Src or phospho-mimetic Cortactin is sufficient to inhibit ciliogenesis. Our results suggest that MIM promotes ciliogenesis by antagonizing Src-dependent phosphorylation of Cortactin and describe a mechanism linking regulation of the actin cytoskeleton with ciliogenesis and Shh signaling during tissue regeneration.
On the performance of a DS/SS system in a band-limited multipath environment

Direct sequence spread spectrum systems for band limited multipath channels are considered. The trade off between processing gain and intersymbol interference with various fixed bandwidths is investigated. Two chip waveforms, rectangular and raised cosine, are examined for both deterministic and random spreading sequences. The performance measure of interest is signal to interference ratio (SIR). A general expression for SIR that applies to a broad spectrum of cases is derived. The numerical results suggest that though a larger number of chips per bit results in more intersymbol interference due to bandwidth limitations, the increased interference suppression capability is able to overcome the degradation and yields a better performance. >
Disinhibitory recruitment of NMDA receptor pathways in retina

Glutamate release at bipolar to ganglion cell synapses activates NMDA and AMPA/kainic acid (KA) ionotropic glutamate receptors. Their relative strength determines the output signals of the retina. We found that this balance is tightly regulated by presynaptic inhibition that preferentially suppresses NMDA receptor (NMDAR) activation. In transient ON-OFF neurons, block of GABA and glycine feedback enhanced total NMDAR charge by 35-fold in the ON response and 9-fold in the OFF compared with a 1.7-fold enhancement of AMPA/KA receptors. Blocking only glycine receptors enhanced the NMDAR excitatory postsynaptic current 10-fold in the ON and 2-fold in the OFF pathway. Blocking GABAA or GABAC receptors (GABACRs or GABAARs) produced small changes in total NMDAR charge. When both GABAARs and GABACRs were blocked, the total NMDAR charge increased ninefold in the ON and fivefold in the OFF pathway. This exposed a strong GABACR feedback to bipolar cells that was suppressed by serial amacrine cell synapses mediated by GABAARs. The results indicate that NMDAR currents are large but latent, held in check by dual GABA and glycine presynaptic inhibition. One example of this controlled NMDAR activation is the cross talk between ON and OFF pathways. Blocking the ON pathway increased NMDAR relative strength in the OFF pathway. Stimulus prolongation similarly increased the NMDAR relative strength in the OFF response. This NMDAR enhancement was produced by a diminution in GABA and glycine feedback. Thus the retinal network recruits NMDAR pathways through presynaptic disinhibition.
Dimensional variations of castings and moulds in the ceramic mould casting process

Abstract Ceramic mould casting process produces high precision castings at a relatively low cost for the production of small number of parts, making it particularly suitable for producing moulds and dies. There is a constant demand for improving the process capabilities including dimensional accuracy and consistency. In this study, dimensional changes and variability of ceramic moulds and steel castings (P20) have been investigated using a pyramid-shaped part. It was shown that the accuracy of the ceramic mould plays a dominant role in obtaining tight casting tolerances. It was also shown that the dimension, location and orientation of a feature on the part had significant effects on the overall linear dimensional changes as well as the dimensional variability of the ceramic mould and the casting. The complex dependence of dimensional variations on feature orientation and location on the part has been discussed on the basis of asynchronous burning on the mould cavity surface at different locations during the burning-out process.
Optical label swapping using payload envelope detection circuits

Optical label swapping of 10-Gb/s nonreturn-to-zero (NRZ) labels attached to 40-Gb/s return-to-zero payloads is demonstrated using payload envelope detection (PED) circuits based on 40-Gb/s clock recovery with nanosecond locking time. The circuits generate a digital envelope signal representing the payload location without having to process the 40-Gb/s data. The low-frequency PED signal, which is generated from the recovered 40-GHz packet clock by a radio-frequency mixer, can be utilized to erase/rewrite the label through traveling-wave electroabsorption modulators. This approach does not require active timing control to erase the label. Nearly penalty-free rewriting of a new 10-Gb/s NRZ label was demonstrated.
JOBS IN HARLEM: A STATISTICAL ANALYSIS

This paper had its origin in the War on Poverty. We were analyzing the economy of Central Harlem in connection with an action project of the Office of Economic Opportunity. One of our tasks was to evaluate the possibility of increasing local employment and raising living standards by stimulating locally owned enterprise. For this purpose, it was obviously desirable to know at the outset how many jobs were actually located within Harlem and how the black community compared in that respect with other neighborhoods outside the central business district. We also hoped to go beyond straightforward description to measure, by means of multiple regression techniques, the forces that determine the job level within Manhattan neighborhoods. Specifically, we wanted to see whether the racial composition of a neighborhood has any discernible effect on the number of local jobs. Finally, we believed that analysis would reveal some of the interconnections between job levels in the major industries and trades within neighborhoods.
Testing of the Toyota Avensis DPNR at U.S. EPA-NVFEL

An advanced prototype of the Toyota Avensis light-duty diesel vehicle equipped with a version of Toyota’s DPNR exhaust emission control system was tested at the U.S. EPA – NVFEL facility. The vehicle is under development by Toyota Motor Corporation for introduction in Europe. While this particular model is not anticipated to be offered for sale in the U.S., EPA evaluated the vehicle to gauge the current state of light-duty diesel vehicle technology. The vehicle was tested using a low sulfur (6 ppm) diesel fuel with a cetane number that was improved to near typical European levels (~50 cetane). Emission levels over the FTP75 consistent with U.S. Federal Light-Duty Tier 2 emission standards were achieved at levels of fuel economy that are competitive with current light-duty diesel passenger vehicles offered for sale in the U.S. The vehicle was tested with relatively low accumulated mileage. Further testing at 50,000-120,000 accumulated miles will be necessary to determine the long-term durability of the emission control system.
The Middle Scoria sequence: A Holocene violent strombolian, subplinian and phreatomagmatic eruption of Okmok volcano, Alaska

The Middle Scoria deposit represents an explosive eruption of basaltic andesite magma (54 wt. % SiO2) from Okmok volcano during mid-Holocene time. The pattern of dispersal and characteristics of the ejecta indicate that the eruption opened explosively, with ash textural evidence for a limited degree of phreatomagmatism. The second phase of the eruption produced thick vesicular scoria deposits with grain texture, size and dispersal characteristics that indicate it was violent strombolian to subplinian in style. The third eruptive phase produced deposits with a shift towards grain shapes that are dense, blocky, and poorly vesicular, and intermittent surge layers, indicating later transitions between magmatic (violent strombolian) to phreatomagmatic (vulcanian) eruptive styles. Isopach maps yield bulk volume estimates that range from 0.06 to 0.43 km3, with ~ 0.04 to 0.25 km3 total DRE. The associated column heights and mass discharge values calculated from isopleth maps of individual Middle Scoria layers are 8.5 – 14 km and 0.4 to 45 × 106 kg/s. The Middle Scoria tephras are enriched in plagioclase microlites that have the textural characteristics of rapid magma ascent and relatively high degrees of effective undercooling. Those textures probably reflect the rapid magma ascent accompanying the violent strombolian and subplinian phases of the eruption. In the later stages of the eruption, the plagioclase microlite number densities decrease and textures include more tabular plagioclase, indicating a slowing of the ascent rate. The findings on the Middle Scoria are consistent with other explosive mafic eruptions, and show that outside of the two large caldera-forming eruptions, Okmok is also capable of producing violent mafic eruptions, marked by varying degrees of phreatomagmatism.
Method for predicting the maximum reliable angle to use in the monostatic-to-bistatic equivalence theorem

A metric is proposed that allows reliable prediction of the maximum bistatic angle for which the monostatic-to-bistatic equivalence theorem (MBET) can be used. Currently, the theorem leaves the term "sufficiently smooth" undefined, making selection of the maximum angle somewhat subjective. The proposed metric provides a quantitative evaluation of complexity/smoothness, and relates this to an angle limit based on an empirically derived statistical error profile. That is, the metric allows prediction of the maximum bistatic angle for which the MBET provides less than a 1.5 dB error at a confidence level of 95%. Although the metric is presently only demonstrated for two-dimensional (2D) objects at a single polarization and error value, sufficient experiments following the same process can easily extend the method to three-dimensional objects, arbitrary polarizations, and alternate error tolerances. Such a capability allows for optimization of either monostatic collections used for prediction of bistatic data sets, or bistatic computations interpolated to monostatic results.
Ethics and Evidence-Based Medicine: Fallibility and Responsibility in Clinical Science

There can be few better illustrations of why the term ‘evidence-based medicine’ is misleading than the title of Kenneth W Goodman's (no relation) thought-provoking book. The question has been asked many times, but what other sort of medicine is there? Medicine that is intentionally divorced from evidence is unworthy even of ethical consideration. It is the subtitle of the book that is the author's real subject—fallibility and responsibility in clinical science—though even that is wrongly phrased. Had the title been ‘The Ethics of Uncertainty in Clinical Medicine’, I would have started reading with less prejudice.
Efficient segmentation based on Eikonal and diffusion equations

Segmentation of regions of interest in an image has important applications in medical image analysis, particularly in computer aided diagnosis. Segmentation can enable further quantitative analysis of anatomical structures. We present efficient image segmentation schemes based on the solution of distinct partial differential equations (PDEs). For each known image region, a PDE is solved, the solution of which locally represents the weighted distance from a region known to have a certain segmentation label. To achieve this goal, we propose the use of two separate PDEs, the Eikonal equation and a diffusion equation. In each method, the segmentation labels are obtained by a competition criterion between the solutions to the PDEs corresponding to each region. We discuss how each method applies the concept of information propagation from the labelled image regions to the unknown image regions. Experimental results are presented on magnetic resonance, computed tomography, and ultrasound images and for both two-region and multi-region segmentation problems. These results demonstrate the high level of efficiency as well as the accuracy of the proposed methods.
Wearable Sensing for Bio-feedback in Human Robot Interaction

Human robot interaction is occurring more often in today’s society. Robots are being developed to perform a wide variety of tasks, many of which include or even depend on HRI. The three main categories of human robot interaction are human assistance and replacement, human cooperation, and social interaction. The purpose, actions, and overall structure and dynamics of these robots will vary greatly, even within their respective categories. While the many robot designs may vary greatly, feedback is one fundamental that will always improve performance. Many designs include built-in sensors that provide feedback regarding the state of the robot and its environment, but interacting with humans presents a new challenge. Biological feedback from an interacting human can be useful for robots during human interaction. The feedback can be used to increase the effectiveness and safety of a robot’s actions during interaction, which in turn will make humans more comfortable with the interaction. To achieve this, wearable sensors can be used to collect feedback. This chapter will discuss the varying types of interaction under development, and show how feedback from wearable sensors could greatly increase robot performance.
An Optimal Sequence-Based-Controller (OSBC) for a grid-connected three-phase photovoltaic HFL inverter

This paper presents discontinuous modeling and design of an Optimal Sequence-Based-Controller (OSBC) for a grid-connected isolated high-frequency-link (HFL) converter. The OSBC directly controls the switching sequences of the power devices without the need for an intermediate pulse-width modulator as in conventional power converter control schemes. OSBC is realized by solving an optimization problem, determining an optimal switching sequence (comprising a union of feasible sequences) and corresponding time horizon for each switching state of the sequence. Maximum Power Point Tracking (MPPT) is realized using the Perturb & Observe algorithm as embedded in a unified OSBC controller optimizing the overall efficiency of the PV + HFL inverter. The effect of optimizing various control parameters with slow and fast dynamics at different scales is demonstrated. The results are verified using Matlab simulation for a 3 kW, 40 V/208 V three-phase inverter.
Pacific Northwest regional AGU meeting

The 28th Annual Pacific Northwest Regional American Geophysical Union Meeting, September 13–20, 1981, was hosted by the Department of Geology at Central Washington University, Ellensburg, Washington. A total of 31 papers was presented to the 91 registrants in two general sessions. Topics included seismology, general geophysics, volcanology, hydrology, oceanography, and two special symposia: Tectonics of the Columbia Plateau and Neogene —Quaternary Faults of the Pacific Northwest' and ‘Studies of the Eruption of Mount Saint Helens.’ Before and after the formal meetings, several field conferences were conducted to examine the Neogene tectonics of the Coast Range (Bob Bentley, Al Niem, and Ray Wells, leaders); the Columbia River Gorge (Bob Bentley, Marv Beeson, and Terry Tolan, leaders); the western Columbia Plateau northsouth transect (Bob Bentley and Jim Anderson, leaders); Quaternary structures of the Toppenish Ridge anticline (Don Tahkeal, Newell Campbell, and Bob Bentley, leaders); the Umtanum imbricate fault zone and pre-Saddle Mountains unconformity near Priest Rapids Dam (Ed Price and Bob Bentley, leaders); and the Yakima anticlines in the Cle Elum-Wallula deformed zone between Ellensburg and Yakima (Bob Bentley, leader).
Hydrogen Sorption Behavior of the ScH2−LiBH4 System: Experimental Assesment of Chemical Destabilization Effects

The hydrogen storage reaction ScH_2 + 2LiBH_4 → ScB_2 + 2LiH + 4H_2 (8.91 wt %), based on the thermodynamic destabilization of LiBH_4, is predicted to have a reaction enthalpy of ΔH_(300K) = 34.1 kJ/mol H_2. The isothermal kinetic desorption behavior in this system was measured. At temperatures up to 450 °C, less than 5 wt % H_2 is released, which is only half of the theoretical capacity. Powder X-ray diffraction data indicate that LiBH_4 has decomposed into LiH in the final desorption product, but the data provide no evidence that ScH_2 has participated in the reaction. Magic angle spinning NMR (MAS NMR) results do not show that the expected ScB_2 equilibrium product phase has formed during desorption. While the addition of 2 mol % TiCl_3 catalyst does improve desorption kinetics at 280 °C, it does not otherwise assist the destabilization reaction. The calculated reaction enthalpy suggests that this system should be of interest at moderate temperatures, but the large heats of formation of the reactant phases in this system appear to play a critical role in determining overall kinetics. Furthermore, the formation of a Li_2B_(12)H_(12) intermediate phase was determined by MAS NMR, which is an undesirable stable product if reaction reversibility is to be accomplished.
Fear of aids among swingers

A total of 88 swingers in the U.S. responded to a questionnaire dealing with AIDS. Respondents were asked to indicate their level of fear of getting the HIV virus, how often they swing, how long they have swung, their reasons for (or not for) fearing AIDS, and if their sexual habits have changed because of the AIDS epidemic. The main prediction was that they would deny their risk of getting AIDS. This would be manifested in negative correlations between their fear level and both the time and frequency of swinging. Results were mixed. A majority had some fear of getting AIDS; knowing someone who had died from AIDS led to more fear; and a majority said they had changed their sexual habits, but less than 7% had actually quit swinging.
Influence of occupational socialization on the practices and perspectives of two inexperienced adventure educators

A relatively small number of researchers have found it interesting and useful to examine why and how persons choose to be and become adventure educators (AEs) and why they teach as they do. The implications of this knowledge are: (1) gaining insight into novice AEs' perceptions of what is required to provide in-depth and high quality instruction in adventure education; and hence, (2) the impact on the structure of AE training. The purpose of this study was to examine the influence of occupational socialization on two AEs with less than five years' experience. Data were collected using a variety of qualitative techniques while the AEs worked at two, week-long summer camps for elementary and middle school-aged children. They were analysed using standard interpretive methods. Results indicated that both AEs' acculturation led to them entering formal training without having had any structured teaching of adventure content modelled for them, suggesting, as has been found in physical education under similar cir...
Tooth Pulp Tissue Pressure and Hydraulic Permeability

The object of these experiments was to evaluate the hydrostatic pressure and hydraulic permeability of the tooth pulp in situ. A small hole was drilled through the enamel and dentin to the dentinal-pulpal junction in canines and third incisors of anesthetized dogs. A threaded cannula filled with mammalian Ringer's solution was screwed into the hole and connected to a microsyringe and a pressure transducer of very low compliance. Pressure was recorded when the cannula was first inserted into the hole; then small amounts of fluid were injected into the system or withdrawn from the system using the micro-syringe. The equilibrium pressure (Peq), measured after transients had disappeared, was fairly constant for a given tooth over long periods of time. Referred to tooth level (which was approximately heart level), Peq averaged 57 mm Hg (range 38 to 78 mm Hg) in the ten teeth tested. Superimposed upon the steady value was a random deviation (± 3 mm Hg), a hysteresis effect resulting in a higher pressure if the ...
On the number of multiplications necessary to compute a length-2 n DFT

The number of multiplications necessary and sufficient to compute a length-2nDFT is determined. The method of derivation is shown to apply to the multiplicative complexity results of Winograd for a length-pnDFT, for p an odd prime number. The multiplicative complexity of the one-dimensional DFT is summarized for many possible lengths.