cssi/SciSciGPT-SciSciNet huggingface dataset:
Profitability Maps as an Input for Site-Specific Management Decision Making

For over a decade, farmers have been collecting site-specific yield data. Many have formed doubts about this investment because of their inability to directly apply this information as feedback for improving management. The objective of this case-study analysis was to investigate how site-specific decisions can be improved by transforming a long-term multiple-crop yield-map dataset into profit maps that contain economic thresholds representing profitability zones. Ten years (1993-2002) of cleaned yield map data [4, 5, and 1 yr for corn (Zea mays L.), soybean [Glycine max (L.) Merr.], and grain sorghum (Sorghum bicolor L.), respectively] were collected for a 35.6-ha claypan-soil field in Missouri. Actual input costs and crop prices, published custom rates for field operations, and region-specific land rental prices were used to transform yield maps into profitability maps by year, by crop, and overall for 10 yr. Profit maps revealed large field areas where net profit was negative, largely due to negative profit from corn production on areas where topsoil was eroded. The areal extent and degree to which other unique field features affected profitability, such as a tree line and a drainage way, are discussed. This analysis demonstrates how changing yield into profitability metrics can help a producer consider and then decide on different management options. We explore how assessment and exploratory analysis with profitability mapping supports multiple aspects of the decision process, including identification, development, and selection. The decision process discussed supports a producer's need to manage fields with incomplete information and where satisficing rather than optimizing behavior often occurs. This analysis demonstrated how profit mapping can be of value for a producer and provides impetus for the precision agriculture community to consider profit mapping protocols and standards.
Experience of programming beauty: some patterns of programming aesthetics

Abstract There is, in the folklore of computer science, a strong suggestion that programs and the processes of programming can be beautiful. Surprisingly, these same issues of programming aesthetics have not been a focus of empirical research, to date. The purpose of the present work is to begin to address programming aesthetics from a ‘non-folklore’ perspective. Related literature is reviewed and an exploratory empirical study of programming aesthetics is described. The results of this study suggest that patterns of programming aesthetics share common features with patterns of aesthetics in other domains. In particular, programs which are familiar, highly structured, and contain suggestions of hidden information tend to be aesthetically pleasing. Novelty also appears to enhance the aesthetic character of programs.
The High‐Pressure Characterization of Energetic Materials: 2‐Methyl‐5‐Nitramino‐2H‐Tetrazole

The isothermal structural properties, equation of state, and vibrational dynamics of 2MNT were studied under high-pressure using synchrotron XRD and optical Raman and IR microspectroscopy. Analysis of the XRD patterns revealed no indication of a phase transition to near 15 GPa and the pressure-volume isotherm remained smooth to 15 GPa. Near 15 GPa, significant sample damage was observed from the X-ray beam which precluded the acquisition of patterns above this pressure. XRD and Raman spectroscopic measurements showed the monoclinic ambient condition phase of 2MNT remains the dominant phase to near 20 GPa, although a shift of the NO{sub 2} IR active vibrational modes to lower frequencies suggested a subtle geometry modification not reflected in the XRD data.
Oxazole phosphonic acids as fructose 1,6-bisphosphatase inhibitors with potent glucose-lowering activity

To discover an alternative heterocyclic scaffold to the thiazole series of FBPase inhibitors such as thiazole 1, oxazoles were investigated to see if replacing the sulfur of the thiazole scaffold with an oxygen is tolerated. Numerous oxazoles with a phosphonic group linked by both 2,5-furandiyl and –COOCH2– groups were prepared and several oxazoles were discovered to have similar potency as thiazole 1. For example, oxazole 3.10 has an IC50 of 70 nM and lowered blood glucose in normal fasted rats by 61%.
Post-Stratification: A Modeler's Perspective

Abstract Post-stratification is a common technique in survey analysis for incorporating population distributions of variables into survey estimates. The basic technique divides the sample into post-strata, and computes a post-stratification weight w ih = rP h /r h for each sample case in post-stratum h, where r h is the number of survey respondents in post-stratum h, P h is the population proportion from a census, and r is the respondent sample size. Survey estimates, such as functions of means and totals, then weight cases by w h . Variants and extensions of the method include truncation of the weights to avoid excessive variability and raking to a set of two or more univariate marginal distributions. Literature on post-stratification is limited and has mainly taken the randomization (or design-based) perspective, where inference is based on the sampling distribution with population values held fixed. This article develops Bayesian model-based theory for the method. A basic normal post-stratification mod...
Differences in mitochondrial movement and morphology in young and mature primary cortical neurons in culture

Mitochondria have many roles critical to the function of neurons including the generation of ATP and regulation of intracellular Ca2+. Mitochondrial movement is highly dynamic in neurons and is thought to direct mitochondria to specific cellular regions of increased need and to transport damaged or old mitochondria to autophagosomes. Morphology also varies between individual mitochondria and is modulated by fusion and fission proteins such as mitofusin-1 and dynamin-related protein-1, respectively. Although mitochondrial movement and morphology are thought to be modulated to best meet cellular demands, few regulatory signals have been identified. In this study, we examined how the different cellular environments of synaptically immature and mature rat cortical neurons affect mitochondrial movement, morphology, distribution and function. In younger cells, mitochondria were more mobile, were shorter, occupied a smaller percentage of neuronal processes, and expressed greater mitofusin-1 and lower dynamin-related protein-1 protein levels compared with older cells. However, the number of mitochondria per mum of neuronal process, mitochondrial membrane potential and the amount of basally sequestered mitochondrial Ca2+ were similar. Our results suggest that while mitochondria in young neurons are functionally similar to mature neurons, their enhanced motility may permit faster energy dispersal for cellular demands, such as synaptogenesis. As cells mature, mitochondria in the processes may then elongate and reduce their motility for long-term support of synaptic structures.
Adverse effects of chorionic villus sampling: a meta-analysis.

Meta-analysis is a popular tool for combining evidence from several related studies. The technique is usually used to combine randomized clinical trials, case-control studies or prospective studies where each study has its own exposed and unexposed groups. By including separate 'study effects' (either fixed or random), one can combine information about differences between control and exposed groups, while still allowing for study heterogeneity. In this paper, we extend existing methods to combine studies of disparate designs, where some studies do not include concurrent controls. We apply the methods to a meta-analysis of the association of prenatal testing via chorionic villus sampling with the occurrence of terminal transverse limb defects.
An essential role for Rxrα in the development of Th2 responses

A viable hypomorphic allele of mouse retinoid X receptor α (Rxrα) was created by random germline mutagenesis. The mutation (I273N) alters the ligand binding and heterodimerization domain, and causes a 90% decline in ligand-inducible transactivation. Homozygotes develop progressive alopecia and dermal cysts, and progressive exaggeration of Th1 and loss of Th2 responses to antigen. Th1 skewing is directly caused by aberrant function of both antigen-presenting cells and naive CD4 T cells; the predominant Th1 response to antigen is attributable to decreased suppression of regulatory T cells in mutant mouse. Dietary depletion of vitamin A in Th2-prone wild-type mice mimics the immune phenotype caused by the mutation. Hence, RXRα plays an important post-developmental role in the regulation of adaptive immune responses, and provides a plausible link between nutritional environment and the type of adaptive response that results from immunization. See accompanying commentary http://dx.doi.org/10.1002/eji.200535588
Studies on the control of myelinogenesis. II. Evidence for neuronal regulation of myelin production

Summary Tritiated thymidine has been used as a nuclear marker to trace the origin of Schwann cells, sited in the distal stump of a severed unmyelinated nerve, which are able to elaborate myelin around axons regenerating from an anastomosed proximal stump of a severed myelinated nerve. Two types of cross-anastomosis experiments were performed in young, adult rats: (1) the proximal stump of a myelinated sternohyoid nerve was labeled (5 mCi/kg body weight) selectively over a 4-day period of predetermined maximal thymidine uptake and two days later, after flushing the animal repeatedly with cold thymidine, the unmyelinated cervical sympathetic trunk was transected and its unlabeled distal stump linked to the proximal stump of the labeled sternohyoid nerve: (2) the distal stump of an unmyelinated cervical sympathetic trunk was labeled selectively over a 5-day period of predetermined maximal uptake and two days later, after flushing with cold thymidine, the myelinated sternohyoid nerve was severed and its unlabeled proximal stump linked to the labeled distal stump of the cervical sympathetic trunk. The fate of the labeled cells in each type of anastomosis was determined 3 weeks later by autoradiography and liquid scintillation spectrometry. In the first type, a small amount of label had migrated from proximal stumps but labeled Schwann cells were not found in successfully anastomosed distal stumps. In the second type, labeled Schwann cells were seen in the cervical sympathetic trunk in association with myelinated and non-myelinated axons regenerating from the sternohyoid nerve. These data suggest that the presence or absence of myelin formation by a Schwann cell is controlled by some property of the axon with which it is associated. Putative mechanisms underlying neuronal control of myelinogenesis are discussed.
Photosynthetic oxygen evolution: changes in magnetism of the water-oxidizing enzyme

Changes in magnetic susceptibility produced by single-turnover flashes of light have been measured for the first time for four of the oxidation states, so-called S states, produced during oxygen evolution in Photosystem II (PSII) complexes of spinach. The data reveal new insights into the structure and bonding of the manganese cluster responsible for catalysis of water oxidation. In samples that have been dark adapted for 15 min or longer to favor population of the resting S{sub 1} state, a train of six flashes increases the paramagnetism on flashes 1, 3, and 5, while no or small increases are observed on flashes 2, 4, and 6. Advancement to the S{sub 1} state does not restore the dark level of S{sub 1} magnetism. This is due to two effects: formation of net paramagnetism from O{sub 2} release on the S{sub 4} {yields} S{sub 0} reaction (scavengeable by glucose oxidase) and a large increase in magnetism for the S{sub 1}(resting) {yields} S{sub 2} reaction, which is not restored without dark readaptation. Comparison of these data with models proposed for the structure of the manganese site reveals that models in which oxidation of substrate water occurs prior to S{sub 4} or oxidation of magneticallymore » isolated Mn ions cannot account for the susceptibility changes observed. The large increase of 17 {mu}{sub B}{sup 2}/PSII observed for the S{sub 1} (resting) {yields} S{sub 2} oxidation is opposite in sign to the decrease in paramagnetism reported for oxidation of synthetic Mn dimers containing the {mu}{sub 2}-oxo-di-{mu}{sub 2}-carboxylato and di-{mu}{sub 2}-oxo-{mu}{sub 2}-carboxylato bridges undergoing the oxidation Mn{sub 2}(III,III) {yields} Mn{sub 2}(III,IV).« less
The Ultrastructural Interface of Bone Crystals and Organic Matrix in Woven and Lamellar Endochondral Bone

Endochondral bone consists of three calcified regions: calcified cartilage, woven bone, and lamellar bone. Woven or immature bone begins when osteoblastic extrusions or buds calcify; from initial calcification loci, bone crystals grow radially to form spheroidal bone nodules. Nodules eventually coalesce into bone seams. Lamellar bone develops as a sequel to the calcification of cartilage or woven bone. Hydroxyapatite grows into lamellar bone and then is oriented parallel to collagen. Except for the stage of cartilage calcification, intramembranous and endochondral osteogenesis are similar.
Interaction of atrial natriuretic polypeptide and angiotensin II on protooncogene expression and vascular cell growth.

Abstract Recent evidence suggests that vasoconstrictive substances, including angiotensin II (Ang II), may function as a vascular smooth muscle growth promoting substance and may contribute to vascular hypertrophy in hypertension. Atrial natriuretic polypeptide (ANP) is known to be a physiological antagonist to Ang II in blood pressure and fluid homeostasis. Moreover, we have demonstrated that ANP can attenuate Ang II's action on vascular hypertrophy. In this study, we investigated the potential molecular mechanisms for the interaction of ANP and Ang II on vascular cell growth. Ang II dose-dependently induced RNA synthesis in post confluent cultured rat aortic smooth muscle (RASM) cells. ANP (10−7M) inhibited the hypertrophic effect of Ang II at the concentration of 10−10 – 10−8M but exerted no effect on the action of higher doses (10−7 – 10−6M) of Ang II. Ang II (10−9 – 10−8M) and a protein kinase C activator, phorbol 12-myristate 13-acetate (PMA, 10−8M) rapidly induced c-fos as well as c-Jun and Jun-B mRNA expression in RASM cells. ANP (10−7M) itself had no apparent effect on the expression of these protooncogenes. Furthermore, ANP did not inhibit the induction of these protooncogenes by Ang II or PMA. Paradoxically, ANP (10−7M) significantly enhanced c-fos mRNA expression induced by Ang II and PMA. However, the chloramphenicol acetyl transferase (CAT) assay using a CAT expression vector containing the AP-1 binding element showed that ANP had no effect on the basal and PMA-stimulated AP-1 activity in transfected RASM cells. We conclude, therefore, that the inhibitory effect of ANP on the growth of vascular smooth muscle cells in vitro does not occur through the regulation of these protooncogene expressions.
Quantum wells and superlattices in strong time-dependent fields.

The behavior of electrons in quantum semiconductor structures interacting with strong far-infrared laser radiation is discussed, under circumstances where quantum tunneling is important. The systematic appearance of avoided crossings in the quasienergy spectrum of a two-state system is related to the frequency spectrum of radiation scattered from a laser-driven double well. The application of the adiabatic approximation to a periodically forced superlattice explains the collapse of quasienergy minibands and leads to the prediction of a possible inhibition of wave-packet spreading.
Ni and CO: more surprises

Recent structural studies of acetyl-coenzyme A synthase/carbon monoxide dehydrogenase from Moorella thermoacetica revealed a unique Cu-Ni-[Fe4-S4] active site. New data now indicate that active enzyme contains a Ni-Ni-[Fe4-S4] site. Novel chemistry is posited for the central Ni atom of this enzyme, which utilizes the toxic gas CO as a catalytic intermediate.
Torres Naharro’s Rhetorical Skirmish in Comedia Himenea

Bartolome de Torres Naharro’s (1485–1530) most well known comedy to the modern reader is his Himenea (1516?). There are outstanding similarities between this work and works that would be written by the later dramaturges, especially Lope de Vega. In Torres Naharro’s plays, a wide range of characters appear, each generally speaking in a register appropriate to his or her station. Another notable use of language is Torres Naharro’s deployment of formal rhetoric in the work. I demonstrate that throughout the play, characters often use the precepts expounded in classical rhetoric in an attempt to persuade or convince other characters of their guilt or innocence (the judicial genre) or to convince others to follow a course of action (the deliberative genre). I conclude that far from being a casual or accidental characteristic of the work, these highly stylized rhetorical passages, the context in which they are delivered and the effect that they have lead the spectator to consider the very nature of rhetoric. Torres Naharro consciously exposes the seamy underside of rhetoric and exposes its weaknesses—the inherent corruptibility of the art by the unscrupulous, and rhetoric’s ultimate failure even when expertly deployed.
Biomethanation in Guyana

In 1980, eight family digesters were built in Guyana with sponsorship and supervision of the Latin-American Energy Organization (OLADE). This programme collapsed in 1983 because of the high costs of the construction materials and the lack of trained personnel to manage and operate the systems. In 1985 an agreement with China led to the construction of six digesters, the training of 15 persons in biogas construction techniques and of another 30 persons in operation and management techniques. This agreement finally led to 21 operational digesters. In the future the emphasis will be given to the development of medium size, industrial or commercial digesters. Opportunities exist in the large livestock farms away from the energy supply, the national distilleries and for the biomethanation of aquatic weeds infesting the waterways.
Sudden infant death syndrome: a failure of compensatory cerebellar mechanisms?

The mechanisms underlying failure in sudden infant death syndrome may involve inadequate compensatory motor responses to a hypotensive challenge; the insult may result from a shock-like sequence, or from a ventilatory challenge that leads to a hypotensive event. Structures ordinarily not considered in mediating breathing or cardiovascular control, especially cerebellar-related structures, may play a critical role in compensatory responses, and underlie the position-dependent risk for SIDS. Dysfunction in affected brain areas appears to arise prenatally from a compromised fetal environment, with a nicotinic component contributing to the deficient mechanism. Physiologic characteristics of infants who later succumb to SIDS, and cardiovascular events associated with the fatal scenario suggest a failure of interaction between somatomotor and autonomic control mechanisms in infants at risk for the syndrome. A failure of compensatory motor actions to overcome a profound hypotension, perhaps mediated by cerebellar mechanisms that regulate blood pressure, may underlie the fatal event.
Intestinal infection and toxin production by Clostridium botulinum as one cause of sudden infant death syndrome

The spontaneous production of botulinum toxin in the infant gut by ingested Clostridium botulinum organisms is the underlying cause of infant botulism, recognised as an infectious disease only in late 1976. Because of the recognition of the pathophysiology of this disease and because the known potency and action of botulinum toxin can lead to rapid respiratory arrest, it appeared possible that the in-vivo production of botulinum toxin could cause the sudden death of some infants. To test this hypothesis, serum, selected tissues, and bowel contents from 280 dead infants were examined for the presence of C. botulinum toxin and/or organsisms. We found C. botulinum organisms in 10 infants, all of whom died suddenly and unexpectedly. 9 of these deaths were classified by the forensic pathologist as sudden infant death syndrome (S.I.D.S. or crib death). In 2 of these 10 sudden deaths both C. botulinum organisms and botulinum toxin were identified, and from the spleen of 1, C. botulinum organisms were isolated. Faecal specimens from 160 age-matched healthy infants who served as controls in studies of inpatient infant botulism cases were negative for both C. botulinum organisms and toxin, except for one specimen that contained only C. botulinum type A organisms. The 9 S.I.D.S. cases with evidence of C. botulinum infection comprised 4.3% of the 211 S.I.D.S. cases examined over 12 months. These findings suggest that intestinal production of botulinum toxin by C. botulinum is one cause of S.I.D.S. The strikingly similar age-distribution of 62 inpatient infant botulism cases and the 211 S.I.D.S. cases is also consistent with this concept. The possibility that in-vivo production of botulinum toxin may account for a larger proportion of S.I.D.S. cases is discussed.
Synthesis of [13C4]furan

Furan is a liver toxicant and carcinogen in laboratory animals. [13C4]Furan was required for in vivo metabolism and mechanistic studies. It was prepared in five steps from commercially available [13C3]propargyl alcohol and [13C]paraformaldehyde. Copyright © 2005 John Wiley & Sons, Ltd.
Limitations of the equilibrium theory of countercurrent devices

In the analysis of countercurrent adsorption processes, an equilibrium theory in which local equilibrium between the fluid and the adsorbent phases is assumed has been used in the past to determine the composition of the pinch state that would be obtained for long columns. It is shown that this equilibrium theory is deficient and that certain mass transfer parameters, which are lost in the procedure by which the model equations for the equilibrium theory are formulated, can have a profound effect on the composition of the pinch.
On the questionable soundness of factoring ipsative data: A response to Saville & Willson (1991)

Saville & Willson (1991), in this journal, concluded, contrary to many researchers and methodologists, that ipsative scales can be soundly factored and can be viewed as equally valid alternatives to normative scales. We present evidence based on analysis of theoretical and actual data to demonstrate that ipsative scales, although sometimes highly correlated with their normative counterparts, cannot be factored and, when factored, result in predictable factor loading patterns not related to their normative counterparts' factor patterns, and, consequently, will result in invalid factor interpretations. An example is presented where ipsative scores are appropriately and successfully analysed using multinomial statistical techniques. These techniques are more appropriate for ipsative data because ipsative scores contain only categorical information across individuals.
Polarization of specular reflection and near-specular scattering by a rough surface

Polarization of specular reflection and near-specular scattering (NSS) by a randomly rough surface is investigated by the use of a Mueller matrix formulation. The collective effect by a rough surface on the average specular field results in reflectance loss and polarization, which can be explained by an effective medium theory. Effects of random NSS can be represented by a scattering matrix that is partially coherent and polarized. The incoherent and unpolarized part of scattering causes depolarization, and the coherent and polarized parts of scattering change the apparent polarization properties of specular reflection. Results of a simulation and least-squares fit of ellipsometric data to the models including the NSS effect, for a black anodized aluminum sample, are presented. Simultaneous least-squares fits for both ellipsometric data and reflectance data at multiple angles of incidence at three different wavelengths gave approximately the same rms roughness, which agrees with the profilometric values reported previously.
Experimental Investigations on the Coefficient of Restitution of Single Particles

Particle-based modeling approaches, such as the discrete element method, require the definition of accurate contact (collision) models. An essential parameter within these models is the coefficient...
Increased Diacylglycerol Content with Phospholipase C or Hormone Treatment: Inhibition of Phorbol Ester Binding and Induction of Phorbol Ester-Like Biological Responses

The purpose of these studies was to determine whether increased cellular diacylglycerol could modulate phorbol ester receptor properties, in order to demonstrate that diacylglycerol can interact with and modulate the phorbol ester receptor in intact cells. Treatment of GH4C1 cells with bacterial phospholipase C caused an increase in cellular diacylglycerol. This was accompanied by increased PRL secretion and decreased epidermal growth factor (EGF) binding, two responses that also occur with phorbol ester treatment of GH4C1 cells. Phospholipase C treatment led to decreased apparent affinity for phorbol esters with no change in receptor number when measured in intact cells. This is consistent with increased concentrations of a competitive inhibitor of phorbol ester binding in treated cultures. Phospholipase C treatment caused a change in subcellular distribution of phorbol ester receptors, another response characteristic of phorbol ester treatment. TRH is known to activate endogenous phospholipase C activit...
Monoamine depletion alters the entrainment and the response to light of the circadian activity rhythm in hamsters

Reduced amplitude, shorter free-running periods and desynchronization among a number of circadian rhythms are associated with advanced age in rodents. The response of the hamster circadian system to photic stimuli is also altered during senescence. Decreased monoamine levels, receptor sites and neuronal populations are commonly observed in the aging brain. The objective of the present study was to determine if monoamine depletion with reserpine in young hamsters induces changes in the circadian rhythm of locomotor activity similar to those that occur spontaneously with aging. Wheel-running activity of 12 young hamsters under a 14 h-light/10 h-dark cycle was continuously monitored. The total activity level, the times of activity onset, peak and offset and the duration of activity were determined during a 1-week period after vehicle treatment and for three 1-week periods after reserpine treatment (4 mg/kg). A second group of eight reserpine-treated and six vehicle-treated animals was kept in constant darkness (DD). The period of the circadian activity rhythm in DD and the phase-shifts after short light pulses at circadian time 19 (CT19) were determined in the control and reserpine-treated groups. Brain monoamines in the hypothalamus, striatum and pons/medulla after reserpine and vehicle treatment were determined by high-pressure liquid chromatography. The data were analyzed with x2 periodogram and one-way ANOVA followed by Duncan's post hoc test. Reserpine treatment significantly reduced total wheel-running activity and the monoamine levels in the hypothalamus, striatum and pons/medulla.(ABSTRACT TRUNCATED AT 250 WORDS)
Trace Level Detection of Compounds Related to the Chemical Weapons Convention by 1H-Detected 13C NMR Spectroscopy Executed with a Sensitivity-Enhanced, Cryogenic Probehead

Two-dimensional 1H-13C HSQC (heteronuclear single quantum correlation) and fast-HMQC (heteronuclear multiple quantum correlation) pulse sequences were implemented using a sensitivity-enhanced, cryogenic probehead for detecting compounds relevant to the Chemical Weapons Convention present in complex mixtures. The resulting methods demonstrated exceptional sensitivity for detecting the analytes at trace level concentrations. 1H-13C correlations of target analytes at < or = 25 microg/mL were easily detected in a sample where the 1H solvent signal was approximately 58,000-fold more intense than the analyte 1H signals. The problem of overlapping signals typically observed in conventional 1H spectroscopy was essentially eliminated, while 1H and 13C chemical shift information could be derived quickly and simultaneously from the resulting spectra. The fast-HMQC pulse sequences generated magnitude mode spectra suitable for detailed analysis in approximately 4.5 h and can be used in experiments to efficiently screen a large number of samples. The HSQC pulse sequences, on the other hand, required roughly twice the data acquisition time to produce suitable spectra. These spectra, however, were phase-sensitive, contained considerably more resolution in both dimensions, and proved to be superior for detecting analyte 1H-13C correlations. Furthermore, a HSQC spectrum collected with a multiplicity-edited pulse sequence provided additional structural information valuable for identifying target analytes. The HSQC pulse sequences are ideal for collecting high-quality data sets with overnight acquisitions and logically follow the use of fast-HMQC pulse sequences to rapidly screen samples for potential target analytes. Use of the pulse sequences considerably improves the performance of NMR spectroscopy as a complimentary technique for the screening, identification, and validation of chemical warfare agents and other small-molecule analytes present in complex mixtures and environmental samples.
Impact of receiver structure and timing offset on MIMO spatial multiplexing

Multiple antenna enhancements via symbol timing relative offsets (MAESTRO) was recently introduced as a scheme to improve the performance of a V-BLAST like multi-antenna system by introducing sub-symbol timing offsets between the transmit antennas. In this paper we address the role of receiver structure on performance and investigate the optimal choice of the time offset parameter. A similar timing offset V-BLAST scheme was also introduced by Shao et al., where the authors use a zero-forcing (ZF) receiver and conclude the system outperforms V-BLAST only for small block sizes. We show that the zero-forcing (ZF) receiver suggested by Shao et al. is deficient and is the main reason for some of the drawbacks observed by them. The optimal ZF receiver is derived, and along with the linear MMSE receiver, is shown to exhibit no such weaknesses. The problem of optimal offset is also examined and the optimal offset for a 2 times 2 MIMO system derived.
Ciliated Epidermal Cells in Non‐teleost Actinopterygian Fish

Scanning electron microscopy reveals the presence of ciliated epidermal cells that form halos around canal pores and pit lines of the mechanoreceptive lateral line system in two actinopterygian fish, Polypterus and Acipenser. Transmission electron microscopy shows that the cilia exhibit a typical 9 + 2 microtubule configuration and are not directionally polarized. The function, developmental origin and systematic significance of ciliated epidermal cells in actinopterygian fish are considered.
Dimerization and trapping of diazirinyl radicals

Computational and experimental methods have been utilized to examine the facile dimerization of diazirinyl radicals. Two potential dimers were investigated using density functional theory. Both were shown to have low-barrier reaction coordinates leading to formation of HCN and N2. A cross-over experiment was employed to establish the relative contributions of C–N and N–N dimers towards product formation. The N–N dimerization was found to be dominant under the current conditions, and the corresponding reaction coordinate energetics were further explored using coupled-cluster methods. A detailed mechanism for dimer decomposition is presented. The competition between unimolecular and bimolecular reactions of diazirinyl radicals is explored under high dilution conditions. The high reactivity of the diazirinyl radical as a nitrogen atom transfer agent suggests a possible bimolecular contribution for “prompt” NO formation in hydrocarbon combustion with diazirinyl radicals as intermediates.
Axonal transport: a dynamic view of neuronal structures

Abstract When a neurobiologist looks into the nervous system through his mind's eye he often sees a favorite nerve cell extending its axon over great distances within the organism. Whether this mental picture is of an alpha motor neuron, R-2 o f Aplysia, a pyramidal cell, or a Mauthner cell, it is almost always a static image because it has undoubtedly been derived through a histological procedure. However, hidden from view in this snapshot o f a frozen cell is an essential rhythm of life which first brought about this special neuronal architecture and which supports the continued existence of the axon, a slender process which may measure only a few microns in diameter but at the same time may be meters long. Here Raymond Lasek brings the dynamic aspects of axonal biology into focus.
The French revolution and British popular politics

(1993). The French revolution and British popular politics. History of European Ideas: Vol. 17, No. 5, pp. 665-667.
Lobeline, a potential pharmacotherapy for drug addiction, binds to μ opioid receptors and diminishes the effects of opioid receptor agonists

Abstract Lobeline diminishes the behavioral and neurochemical effects of nicotine and amphetamines, and is considered a potential pharmacotherapy for drug abuse and addiction. Lobeline has high affinity for nicotinic acetylcholine receptors and inhibits the function of vesicular monoamine and dopamine transporters. The present study investigated the less-explored interaction of lobeline and the endogenous opioid system. In guinea pig brain homogenates, lobeline displaced ( K i = 0.74 μM) the binding of [ 3 H]DAMGO [(D-Ala 2 , N -ME-Phe 4 , Gly 5 -ol)-enkephalin]. In a functional assay system comprised of MOR-1 μ opioid receptors and GIRK2 potassium channels expressed in Xenopus oocytes, lobeline had no effect on the resting current, but maximally inhibited (IC 50 = 1.1 μM) morphine- and DAMGO-activated potassium current in a concentration-dependent manner. In a second functional assay, lobeline-evoked [ 3 H]overflow from rat striatal slices preloaded with [ 3 H]dopamine was not blocked by naltrexone. Importantly, concentrations of lobeline (0.1–0.3 μM) that did not have intrinsic activity attenuated (∼50%) morphine-evoked [ 3 H]overflow. Overall, the results suggest that lobeline functions as a μ opioid receptor antagonist. The ability of lobeline to block psychostimulant effects may be mediated by opioid receptor antagonism, and lobeline could be investigated as a treatment for opiate addiction.
Enhanced cellular immune responses to SIV Gag by immunization with influenza and vaccinia virus recombinants

An effective vaccination strategy against human immunodeficiency virus type 1 (HIV-1) should include the induction of potent cellular immune responses against conserved HIV-1 antigens. We have generated five replication competent recombinant influenza viruses (rFlu/SIV Gag nos. 1-5) expressing different portions of Gag of simian immunodeficiency virus (SIV). Single intranasal immunizations in mice with each rFlu/SIV Gag viruses resulted in different degrees of protection against a challenge with recombinant vaccinia virus expressing SIV Gag. Immunized BALB/c mice had detectable CD8+ T cell responses specific for Gag peptide 185-199 when mice were vaccinated with rFlu/SIV Gag no. 3 virus, and for Gag peptides 281-295 and 285-299 when vaccinated with rFlu/SIV Gag no. 4 virus. Cellular immune responses against SIV Gag were further enhanced by a booster with a recombinant vaccinia virus expressing SIV Gag in both the spleen and local lymph node tissues, resulting in the induction of robust Gag-specific CD8+ T cell responses at both systemic and mucosal levels. We suggest that a prime-boost immunization regimen using recombinant influenza and vaccinia viruses expressing HIV Gag might represent an effective means to induce potent HIV-specific, protective CD8+ T cell responses.
Policy framework supporting youth aging-out of foster care through college: Review and recommendations

Abstract A college degree opens doors to higher paying and more stable employment. This holds particular importance for youth aging-out of foster care who must attain self-sufficiency with little or no family support. However, these youth have lower rates of college entrance, persistence, and completion than same-aged peers. Over the past 25 years, several major pieces of federal legislation have extended and increased support to youth aging-out of care who are pursuing a postsecondary degree. Although these laws have been important steps in the right direction, federal support ends too soon and variability in state policies and college-specific services leave many youth with inadequate support. Policy reform can further render postsecondary completion a viable, realistic expectation. Three recommendations to improve current legislation include: extend the Foster Care Independence Act (FCIA) funding to age 25, establish campus-based support programs funded through FCIA, and adjust Educational Training Voucher disbursements to reflect the changing cost of college.
Logarithmic laws for compressible turbulent boundary layers

Dimensional similarity arguments proposed by Millikan are used with the Morkovin hypothesis to deduce logarithmic laws for compressible turbulent boundary layers as an alternative to the traditional van Driest analysis. It is shown that an overlap exists between the wall layer and the defect layer, and this leads to logarithmic behavior in the overlap region. The von Karman constant is found to depend parametrically on the Mach number based on the friction velocity, the dimensionless total heat flux, and the specific heat ratio. Even though it remains constant at approximately 0.41 for a freestream Mach number range of 0 to 4.544 with adiabatic wall boundary conditions, it rises sharply as the Mach number increases significantly beyond 4.544. The intercept of the logarithmic law of the wall is found to depend on the Mach number based on the friction velocity, the dimensionless total heat flux, the Prandtl number evaluated at the wall, and the specific heat ratio. On the other hand, the intercept of the logarithmic defect law is parametric in the pressure gradient parameter and all of the aforementioned dimensionless variables except the Prandtl number. A skin friction law is also deduced for compressible boundary layers. The skin friction coefficientmore » is shown to depend on the momentum thickness Reynolds number, the wall temperature ratio, and all of the other parameters already mentioned. 26 refs.« less
Performance of Children with Good and Poor Articulation on Tasks of Tongue Placement

This study determined whether children could learn to replicate four positions of lingual-palatal contact with and without topical anesthesia that eliminated touch-pressure sensations. First-grade boys, nine with good articulation skills and nine with poor articulation skills, were used as subjects. Results suggest that individuals are able to learn nonspeech tasks of tongue positioning by relying on muscle spindles or deep receptors within the tongue, or both, or by relying on lingual touch-pressure or other surface receptors within the tongue, or, by a combination of deep and surface receptors of the tongue. Further, tongue positioning need not be dependent on touch-pressure or superficial tactile mechanisms. Children with relatively severe articulation problems performed more poorly on the tasks of precise tongue placement than children with good articulation skills. And finally, children with relatively severe articulation problems may be able to improve their initially poor performance on tongue plac...
Ant-dependent food plant selection by the mistletoe butterfly Ogyris amaryllis (Lycaenidae).

A quantitative study of the relationship between antoccupied mistletoes and oviposition by Ogyris amaryllis (Lycaenidae) revealed diet selection to be ant-dependent. Chemical toxins apparently prohibit the use of ant-occupied Lysiana plants. Nearly all of the 5106 censused eggs were laid on Amyema individuals with ants, independent of plant abundance or relative quality. On the average, only 32% of these nutritionally acceptable individuals were actually suitable for oviposition. The selection of Amyema maidenii with ants over nutritionally superior A. preissii without ants clearly identifies the secondary importance of food quality to O. amaryllis. Oviposition normally occurs after tactile stimulation by ants. Under experimental conditions without ants, females often laid clutches of 1–3 eggs, but significantly increased clutch size after contact with ants. Eggs laid in the presence of ants had lower parasitism rates than eggs laid away from ants.
The neural substrate for the pupillary light reflex in the pigeon (Columba livia)

The neural substrate of the pupillary light reflex in the pigeon was investigated using anatomical, stimulation, and lesion techniques. In birds, as in mammals, the sphincter pupillae muscle (which constricts the iris) is innervated by cells in the ciliary ganglion (Pilar and Tuttle, '82). These cells are in turn innervated by cells in the Edinger-Westphal nucleus (EW) (Cowan and Wenger, '68; Narayanan and Narayanan, '76; Lyman and Mugnaini, '80). The efferent link of the pupillary light reflex must therefore involve cells in EW. To study the central course of this reflex pathway, injections of horseradish peroxidase (HRP) were placed in EW. These injections labeled cells in a number of regions including a contralateral pretectal nucleus, area pretectalis (AP). Only a limited number of cells in AP project to EW. Injections of tritiated amino acids into AP labeled a discrete region of the contralateral EW. This projection is confined to a dorsolateral region of caudal EW and overlies the somata of approximately 100 cells. Tritiated proline was injected into the eye, and the results confirmed an earlier report (Reperant, '73) that AP receives retinal input from the contralateral eye. Immunohistochemical studies demonstrated fibers in AP that stained positively for Substance-P-like, enkephalin-like and tyrosine-hydroxylase-like immunoreactivity. Injections of HRP were placed in AP to examine the retinal ganglion cells mediating the reflex. Cells with an average diameter of approximately 14 μm (5–25 μm range) were labeled and averaged approximately 6 μm greater in diameter than the retinal ganglion cells (mean = 7.3 μm) labeled by an optic chiasm injection. The cells labeled by AP injections were distributed unevenly throughout the retina with a higher concentration in the central and temporal retina and a paucity in the red field and fovea. Our results demonstrate that AP receives input from a distinct sub-population of large retinal ganglion cells that comprises a very small percentage of the total population of retinal ganglion cells. Unilateral lesions of AP abolished the pupillary light reflex in the eye contralateral to the lesion; stimulation of AP elicited pupilloconstriction in the eye contralateral to the stimulation site. These results delineate the central course of the pupillary light reflex pathway in the pigeon and identify the retinal ganglion cells that subserve this reflex. They show that, at every point in the pathway, only a few cells mediate this simple reflex. These studies have allowed us to compare the pupillary light reflex pathway in the pigeon and monkey, and based on recent anatomical studies in the monkey (Steiger and Buttner-Ennever, '79; Magnuson et al., '80), we propose that the central course is similar in both species and that the projection from the pretectum to EW is entirely crossed.
Clinical Phonocardiography: Reversed (Paradoxic) Splitting of the Second Heart Sound in Aortic Stenosis

The communication which follows inaugurates a new department in Diseases of the Chest entitled “Graphic Techniques in Cardiology.” This section will provide reports which document the clinical applicability of data obtained from the electrocardiogram, phonocardiogram, apexcardiogram, echocardiogram and other laboratory procedures. The format will consist of the presentation of specific, clinical problems which illustrate the unique contributions of certain graphic techniques. The subject for presentation this month is clinical phonocardiography; the application of phonocardiography in evaluation of aortic stenosis was prepared by Morton E. Tavel, M.D., author of the text, Clinical Phonocardiography and External Pulse Recording, Yearbook Medical Publishers, Chicago, 1967. Editor
Magnetic Moment Operator of the Relativistic Electron

We consider for the Dirac electron the operator $\stackrel{\ensuremath{\rightarrow}}{\mathrm{m}}=(\frac{1}{2})e\stackrel{\ensuremath{\rightarrow}}{\mathrm{x}}\ifmmode\times\else\texttimes\fi{}\stackrel{\stackrel{\ifmmode\bullet\else\textbullet\fi{}}{\ensuremath{\rightarrow}}}{x}$ in the Heisenberg representation, and prove, by separating the center-of-mass coordinate ${\stackrel{\ensuremath{\rightarrow}}{\mathrm{x}}}_{A}$ and the relative coordinate $\stackrel{\ensuremath{\rightarrow}}{\ensuremath{\xi}}$ of the charge with respect to the center of mass (i.e., Zitterbewegung), that the orbital angular momentum of the Zitterbewegung is equal to the spin with the correct $g$ factor 2. The odd and even parts of $\stackrel{\ensuremath{\rightarrow}}{\mathrm{m}}$ and the correct identification of the $\stackrel{\ensuremath{\rightarrow}}{\mathrm{L}}$ and $\stackrel{\ensuremath{\rightarrow}}{\mathrm{S}}$ operators are discussed.
The pure rotational spectrum of ZnCl (X2Σ+): Variations in zinc halide bonding

Abstract The radical ZnCl (X 2 Σ + ) has been studied using millimeter-wave direct-absorption techniques. Pure rotational spectra of 67 Zn 35 Cl, 66 Zn 37 Cl, 68 Zn 35 Cl, 64 Zn 35 Cl, 64 Zn 37 Cl, and 66 Zn 35 Cl were measured in the vibrational ground state and data were also recorded for the latter three in the v = 1 and v = 2 states. Every rotational transition was found to be split into a doublet due to spin–rotation interactions. For 67 Zn 35 Cl, each doublet exhibited additional splittings arising from hyperfine coupling of the 67 Zn ( I = 5/2) nucleus. Rotational, fine structure, and hyperfine constants have been determined from these data, and equilibrium parameters calculated. The equilibrium bond length of 64 Zn 35 Cl is found to be 2.13003305(24) A, in good agreement with recent theoretical predictions. Interpretation of hyperfine constants indicates that the 12σ orbital is ∼70% Zn(4s) in character, suggesting that the zinc chloride bond is relatively ionic.
Chronic caffeine consumption exacerbates hypertension in rats with polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is a common inherited disorder frequently associated with renal failure, hypertension, and other abnormalities. The present study determined whether chronic caffeine intake in an animal model of this disease would affect renal structure and function and blood pressure. Heterozygous male Han:Sprague-Dawley rats with ADPKD and normal littermates were provided with either tap water or solutions of caffeine to drink, starting at 1 month of age. When rats were aged 6 months, glomerular filtration rate (GFR) and mean arterial blood pressure (MAP) were measured under Inactin (Byk Gulden, Konstanz, Germany) anesthesia. Caffeine intake had no effect on GFR or cyst development in rats with PKD. MAP was greater in rats with PKD than normal rats and was increased more by caffeine. The hypertensive effect of chronic caffeine intake could not be ascribed to direct pressor effects of angiotensin II. Based on our finding that caffeine exacerbates hypertension in rats with PKD, it may be prudent for patients with ADPKD to limit coffee consumption to four or fewer cups of caffeinated coffee per day, pending studies of humans.