cssi/SciSciGPT-SciSciNet huggingface dataset:
Fine Particulate Organic Material at Meadview During the Project MOHAVE Summer Intensive Study

The Brigham Young University (BYU) organic sampling system (BOSS) and the high flow rate multi-system BYU organic sampling system (BIG BOSS), which use multichannel diffusion denuder sampling techniques, were both used to collect samples of atmospheric fine particulate organic material. Both systems were used at the Meadview sampling site located at the western boundary of the Grand Canyon National Park in northwestern Arizona for the Project MOHAVE summer intensive sampling program in August 1992. The concentrations of total fine particulate carbonaceous material determined by temperature programmed volatilization for BOSS collocated replicate samples were in agreement with an uncertainty of ±14%. A comparable agreement was seen between the BOSS and BIG BOSS samples. Carbonaceous material collected by the second of two sequential quartz filters was shown to have originated from organic material lost from particles during sampling. About one-half of the fine particulate organic material was lost from particles during sample collection. These semi-volatile organic compounds lost from particles during sampling were characterized by GC/MS analysis. The concentrations of n-alkanes, n-fatty acids, n-fatty methyl esters, and phthalic acid as a function of fine particulate size were obtained for compounds both retained by and lost from particles during sampling. The possible sources of fine particulate semi-volatile organic material collected at Meadview, and the particle size distribution of fine particulate organic material, n-alkanes, n-fatty acids, and n-fatty esters are discussed.
Exchange Approximations Used in the Energy-Band Calculations of Metals

The use of different exchange approximations in the self-consistent energy-band calculations for a metal (Cu) is shown to yield different one-electron eigenvalue spectra. Specifically, when an energy-dependent exchange potential proposed by Liberman was used, the resulting bandwidths ($s\ensuremath{-}p$, $d$) were much wider than those obtained with the ${\ensuremath{\rho}}^{\frac{1}{3}}$ exchange operator. Also it is shown that when the energy-dependent exchange operator is screened, as in the Bohm-Pines theory, the resulting bandwidths were considerably narrowed. Although the "${\ensuremath{\rho}}^{\frac{1}{3}}$" operator and the screened-exchange operator yielded similar results, the variation of the screening parameter did not correspond to a variation of the $\ensuremath{\alpha}$ parameter of the "${\ensuremath{\rho}}^{\frac{1}{3}}$" method. Use of the screened-exchange operator appears to yield a reasonable band structure.
Enzyme regulation as an approach to interference with polyamine biosynthesis — an alternative to enzyme inhibition

Abstract The progress reviewed here would seem to validate the regulatory approach to interference with polyamine biosynthesis as an antiproliferative strategy. To our knowledge, this is the first example, among anticancer drugs, of pharmacological intervention of a biochemical pathway based strictly on regulatory control. Several features of polyamine biology naturally favor this approach and may account for its relative success. These include (a) the nature of the regulatory mechanisms themselves, (b) the exquisite sensitivity of the pathway to regulatory control, (c) the rapid turnover of ODC and AdoMetDC, (d) the different structural specificity of ODC and AdoMetDC regulation versus growth-dependent functions, and (e) the direct dependence of growth on sustained polyamine biosynthesis. As such, the regulatory approach to interference with polyamine biosynthesis offers several advantages over the use of specific enzyme inhibitors (Table 10). Of these, perhaps, the more significant are the facts that more than one enzyme can be simultaneously and specifically suppressed and that compensatory mechanisms, which otherwise counter the effects of enzyme inhibitors (11), are not invoked. We are encouraged by the concurrence of in vitro mechanistic findings with the predictions of the hypothesis for the regulatory approach and by the in vitro and in vivo growth inhibitory effects of the analogs against murine leukemia. One disadvantage of the regulatory analogs, such as BESm, has been that, as with specific polyamine inhibitors such as DFMO, analog-induced polyamine depletion results in cytostatic growth inhibition. While this response may help to minimize host toxicities, it clearly compromises antitumor activity. An intriguing exception to this generality has recently been found among human lung carcinoma cell lines. Previously, Luk et al. (93, 94) and others (95) reported that, among a spectrum of human lung carcinoma lines, small cell carcinoma was exquisitely sensitive to the ODC inhibitor, DFMO. Not only did these cells display a cessation of growth but also an inability to survive during DFMO-induced polyamine depletion. Studies extending these findings to long term maintenance therapy in human small cell lung carcinoma implants in athymic mice revealed sustained growth inhibition of the tumor for longer than one year (96). Casero et al. (97) now find that human large cell carcinoma, which is otherwise refractory to chemotherapeutic intervention, displays a cytotoxic response in vitro to polyamine depletion induced by BES or BESm but not by DFMO. These findings suggest cytotoxic susceptibility to polyamine depletion appears to be agent and cell type specific. Based on these leads, current and future efforts will attempt to identify and exploit these specificities.
FOOD RESERVES IN RELATION TO OTHER FACTORS LIMITING THE GROWTH OF GRASSES

The immediate applied significance of the pronouncements of Liebig (1840) with reference to mineral nutrition of plants, not only gave rise to profound changes in soil culture and crop husbandry, but also furnished the basis of the present fertilizer industry. The classic work of Sachs, Pfeffer, Klebs and others on the organic nutrition of plants, however, has not been utilized to full advantage. Fairly recently (1918) Kraus and Kraybill (12) have attempted to redirect attention to such studies, and many important contributions have been made by such workers as Harvey (9), Murneek (14), Nightingale (17), Roberts (25), Janssen (11), Leukel (13), Tiedjens (28), Albert (1), Nelson (16), Welton (29), Morris (30), and others. Unlike mineral nutrients, the carbohydrates and other organic foods cannot at present be supplied to green plants in a commercial way. They must be elaborated by the living plant itself. The plant producer can vary cultural procedures, however, so that the formation, utilization, storage and destruction of such materials may be controlled or directed and crop production be more or less precisely regulated with reference to quality and yields. Such cultural practices include defoliations by cuttings, pruning and grazing ; fertilization, especially with nitrogenous fertilizers; etiolation by shading or other limitations of light; irrigation and combinations of these treatments. Food reserves as they are discussed in this paper may be regarded in a general way as those organic compounds which are synthesized and maintained in forms capable of being subsequently utilized by the plant in the performance of its various functions. They are labile materials. They involve so great a variety of organic compounds that present chemical technique and knowledge afford a clue of identification and understanding to but relatively few of them. They represent an accumulation or surplus of materials in excess of the immediate requirements of the plant for growth and maintenance. Their utilization is, essentially, most abundant in an environment favorable for growth extension and in those meristematic regions of the plant where the metabolism is most active. Generally, their storage occurs during periods when the accretions in dry weight are most rapid.
Mutarotase (aldose-1-epimerase) catalyzed anomerization of glucose-6-phosphate

Abstract Data obtained by direct polarimetric analysis show that glucose-6-phosphate is a mutarotase (aldose-1-epimerase) substrate; that the enzyme is most active against glucose-6-phosphate at slightly acid pH; and that the monoanion form of glucose-6-phosphate is probably the form involved with mutarotase.
Experimental Observation of Sommerfeld and Brillouin Precursors in the Microwave Domain

An experimental investigation of transient electromagnetic wave propagation in the microwave frequency range related to the theoretical investigation of Sommerfeld and Brillouin is reported. Both the Sommerfeld and Brillouin precursors are shown experimentally.
Intravenous vs. intraprostatic administration of N-methyl-N-nitrosourea to induce prostate cancer in rats.

To develop an improved model of human prostate cancer, 16-wk-old Wistar rats were treated orally for 18 days with the antiandrogen, flutamide (50 mg/kg body weight[BW]/day), weight followed by 3 days of s.c. testosterone (100 mg/kg BW). These were the only treatments the control animals received (Group 1, n = 10). On the day after the third testosterone injection, N-methyl-N-nitorsourea (MNU) was administered via the tail vein at a dose of 50 mg/kg BW (Groups 2, n = 40 and 3, n = 20); in some rats, a second dose was delivered by the same route 22 wk later (Group 3). A smaller dose of MNU (15 mg/kg BW) was administered intraprostatically Group 4, n = 20) to a fourth group. In Groups 2, 3, and 4, silastic capsules containing testosterone were implanted s.c. approximately every 6 wk beginning 1 wk post-MNU. Accessory sex gland tumors arose in MNU-treated rats in Group 2 (12/40, 30%), Group 3 (8/20 40%), and Group 4 (8/20, 40%); 90% were macroscopic (25/28). There were no neoplasms in these organs in the control rats (Group 1, 0/10). These accessory sex gland neoplasms were adenocarcinomas or undifferentiated carcinomas which appeared to be derived from the prostate based on location and histological characteristics, although the size and spread of some of the tumors precluded definitive localization of the tissue of origin. The incidence of these neoplasms was similar in rats given a single dose of MNU intraprostatically or two doses of MNU i.v., but the animals treated intraprostatically maintained higher body weights and developed fewer extraneous tumors. The average (± SD) latent period for clinical or postmortem detection of prostate neoplasia after MNU was shortest in the rats given two i.v. doses (39 ± 3 wk) compared with the single i.v. dose (45 ± 6 wk) or an intraprostatic dose (56 ± 7 wk). In 57% of the cases (16/28), the prostate tumors metastasized to distant sites. An activating point mutation was detected in codon 12 of the Ki-ras oncogene in the MNU-induced primary prostate tumors (8/10 examined), and metastases arising from these prostate tumors (2/3) but was absent in normal prostate tissue (0/6). This study demonstrates that two systemic doses of MNU increase the incidence and decrease the latency of prostate neoplasms compared with a single dose, and that a single dose of MNU injected intraprostatically induces prostate adenocarcinoma without many of the other tumors and weight loss typically found after i.v. administration. © 1995 Wiley-Liss, Inc.
High-field 75As NMR study of arsenic oxysalts

Abstract Arsenic is an important environmental hazard, but there have been few NMR investigations of its molecular scale structure and dynamics, due principally to the large quadrupole moment of 75As and consequent large quadrupole couplings. We examine here the potential of existing, single-field solid-state NMR technology to investigate solids containing arsenate and arsenite oxyanions. The results show that current techniques have significant potential for arsenates that do not contain both protonated H x As O 4 - ( 3 - x ) groups and structural water molecules, but that the quadrupole couplings for the arsenites examined here are large enough that interpretation of the spectra is difficult, even at 21.1 T. Compounds that contain both structural H2O molecules and protonated arsenate groups do not yield resolvable signal, likely a result of T2 effects related to a combination of strong quadrupolar interactions and proton exchange. Spin-echo experiments at 11.7 and 14.1 T were effective for Li3AsO4 and CsH2AsO4, as were whole-pattern spikelet experiments for arsenate oxide (As2O5) at 17.6 and 21.1 T. The central transition resonance of Ca3(AsO4)2·8H2O is ∼6 MHz broad and required a non-conventional, histogram-style spikelet method at high field to improve acquisition efficiency. This approach reduces the acquisition time due to the sensitivity enhancement of the spikelet sequence and a reduction in the number of frequency increments required to map the resonance. Despite the large quadrupole couplings, we have identified a correlation between the 75As isotropic chemical shift and the electronegativity of the next-nearest neighbor cation in arsenate compounds.
The permeability of the corneal endothelium to fluorescein in the normal human eye

Endothelial permeability to fluorescein was measured as part of fluorophotometric studies of aqueous humor flow in 112 normal subjects whose ages span six decades. The permeability was 2.4 ± 0.9 × 10-4 cm/min (mean ± SD). Females had a slightly higher permeability than males. No correlation between age and permeability was noted. The precision of this method of measurement was estimated to be ± 22%.
A unified setting for sequencing, ranking, and selection algorithms for combinatorial objects

The recurrent construction of combinatorial objects proceeds in steps at each of which we modify the partially constructed object by certain elementary operations such as adjunction of a new element, relabeling, etc. The end result of this sequence of decisions is then available, and this subset, permutation, tree, etc. is called the output combinatorial object. It is, of course, just a record of the totality of decisions which were made during its construction, and if it seems profitable to do so, we may regard that sequence of decisions as being itself the combinatorial object, whatever the final presentation may be. Then any natural setting which we construct for dealing with the sequence of decisions itself will ultimately result in procedures for processing the objects. The theory of directed graphs offers such a setting, and from it we are able to present algorithms which deal simultaneously with many families of objects. The prototype of this situation is perhaps the binomial identity
A review of techniques available for estimating short-term NO2 concentrations.

The Environmental Protection Agency is reviewing the need for a short-term NO2 standard based on an averaging time of three hours or less. State Implementation plans and New Source Reviews will require air quality simulation techniques capable of estimating ambient NO2 concentrations. There is a need for multi-source (urban) models and for point source models. A review of currently available techniques for the estimation of NO2 concentrations resulting from NOx point sources is presented. The available methods include simple screening techniques and refined reactive plume models. The screening techniques first use a standard gaussian dispersion model to estimate the maximum 1 hr NOx concentration caused by the source. The second step involves estimating the fraction of this NO* concentration occurring as NO2. Reactive plume models numerically simulate the simultaneous effects of dispersion and chemistry on NO2 concentrations. Organic as well as inorganic reactions are incorporated. Reactive plume models s...
Contesting immigrant voice in Istanbul: Mass media, verbal play, immigrant channels

Abstract This study analyzes mass media and intertextuality in the mediation of communities in a modern Turkish megalopolis. It focuses on a weekly television series and its differential reception by the general Turkish public and an immigrant community whose heritage and dialect are central aspects of the program. The series appropriates a narrative adaptation of “Fiddler on the Roof” to construct a nostalgic frame for imagining earlier Turkish village life. I examine lateral circulation of greeting and leave-taking formula from the weekly television series in the larger urban society, and argue that the choice of these for recirculation is motivated by the political and social polarization implicated in other contemporaneous greeting and leave-taking formula within general Turkish society. At the same time I document counter-recontextualizations of discourse fragments by immigrants in Istanbul who insist that they not be consigned to the distant past evoked by the series. The different meaning of the non-standard dialect for the television series and for the immigrant community – a central misunderstanding – motivates a series of public actions on the part of an immigrant association whose members use internet sites, newspaper editorials and televised annual musical performances to air carefully measured counter-claims regarding their Balkan heritage and their place within the larger Turkish society.
National Cancer Data Base/Surveillance Epidemiology and End Results: potential insensitive-measure bias.

Abstract Objectives. Abstraction of data from National Cancer Data Base (NCDB)/Surveillance Epidemiology and End Results (SEER) for reasons other than incidence, mortality, and patterns of care has risen. A potential problem with these data is that insensitive-measure bias can exist because of possible inaccuracies in hospital tumor registry staging. The purpose of this study is to assess the accuracy of tumor registry staging from six community hospitals. Methods. Staging of 103 consecutive cancers operated on by a gynecologic oncologist (one of the authors) as a surgical consultant to a gynecologist or surgeon was reviewed. Hospital tumor registry staging forms were arbitrarily assigned to be completed by the nongynecologic oncologist versus the gynecologic oncologist by the medical records department. The authors reassessed cancer staging by medical chart review. The tumor registry staging was compared with the actual staging as determined by the authors. Major staging violations were defined as errors that would significantly change stage enough to alter prognosis or change recommended adjuvant treatment. All other violations were defined as minor. Results. Twenty-eight (27%) cancers were staged by the gynecologic oncologist and 75 (73%) by nongynecologic oncologists. Eighty (78%) cancers were endometrial and 14 (13%) ovarian. Eighty-three (81%) tumors were stage I or II. Major staging violations occurred in 0% of cancers staged by the gynecologic oncologist and 22% (16/75) by a nongynecologic oncologist ( P = 0.002). Minor staging violations occurred in 14% (4/28) of cancers staged by the gynecologic oncologist and 42% (32/75) by a nongynecologic oncologist ( P = 0.005). Minor violations were due to omission of histologic subtype and/or grade. Conclusion. The 22% major staging violation rate represents significant insensitive-measure bias. If additional studies produce similar results, abstraction of data from NCDB/SEER for reasons other than incidence, mortality, and patterns of care cannot be accepted as evidence-based scientific medicine.
Advances in the Surgical Management of Low-Grade Glioma

Over the past 2 decades, extent of resection has emerged as a significant prognostic factor in patients with low-grade gliomas (LGGs). Greater extent of resection has been shown to improve overall survival, progression-free survival, and time to malignant transformation. The operative goal in most LGG cases is to maximize extent of resection, while avoiding postoperative neurologic deficits. Several advanced surgical techniques have been developed in an attempt to better achieve maximal safe resection. Intraoperative magnetic resonance imaging, fluorescence-guided surgery, intraoperative functional pathway mapping, and neuronavigation are some of the most commonly used techniques with multiple studies to support their efficacy in glioma surgery. By using these techniques either alone or in combination, patients harboring LGGs have a better prognosis with less surgical morbidity following tumor resection.
Basic fibroblast growth factor treatment delays age-related photoreceptor degeneration in Fischer 344 rats.

Abstract This study was undertaken to investigate the potential of basic fibroblast growth factor (bFGF) to delay photoreceptor cell loss in retinas of Fischer 344 rats which exhibit an age-related peripheral retinopathy. Eight male 16-month-old Fischer 344 rats were injected intravitreally with 2.0 μg bFGF in the right eye, while the vehicle was injected into the left eye and all rats were killed at two months post-injection. Eight other Fischer rats were injected with either bFGF or vehicle at 16 and again at 18 months, then killed two months later. After enucleation, eyes were processed for light and electron microscopic and morphometric analyses. The distance from the ora serrata to the point where the outer nuclear layer (ONL) in the superior retina was two cells in thickness, called the die-back zone, that represents the extent of the peripheral retinopathy, was compared in bFGF- and vehicle-injected Fischer rats. These measurements revealed that the die-back zone in retinas of eyes injected twice with bFGF was significantly reduced ( P P >0.05) in this degeneration zone in retinas of 18-month-old rats that received a single-bFGF injection when compared to retinas of respective vehicle-injected rats. In addition, the ONL at 2 and 3 mm from the ora serrata in the superior retina of bFGF-injected 20-month-old Fischer rats was significantly thicker than corresponding regions in retinas of vehicle-control rats. Furthermore, the photoreceptor cells in the superior retina of 20-month-old rats which received two injections of bFGF had normal-appearing inner and outer segments, while the few photoreceptors had short inner and outer segments in vehicle-injected retinas of Fisher rats. These findings reveal that injections of bFGF into eyes of Fischer 344 rats significantly delays the progress of photoreceptor cell degeneration suggesting that exogenous bFGF may act as a survival-promoting factor in these aged retinas.
Prompt corrective action and bank efforts to recover from undercapitalization

Abstract This study empirically examines the likelihood and timing of bank recoveries from positions of undercapitalization. Our findings indicate that: (1) There appears to be only a limited capacity for banks to ‘correct’ positions of undercapitalization by growth limitations or dividend restrictions; (2) the impact of profitability on recovery is greater the longer a bank remains undercapitalized; and (3) equity infusions are the primary mechanism by which banks can recapitalize quickly. This evidence is relevant to regulators in their implementation of the FDIC Improvement Act of 1991, which requires that undercapitalized banks take ‘prompt corrective actions’ to recapitalize quickly under threat of early closure.
Efflux of red cell water into buffered hypertonic solutions.

Buffered NaCl solutions hypertonic to rabbit serum were prepared and freezing point depressions of each determined after dilution with measured amounts of water. Freezing point depression of these dilutions was a linear function of the amount of water added. One ml. of rabbit red cells was added to each 4 ml. of the hypertonic solutions and after incubation at 38°C. for 30 minutes the mixture was centrifuged and a freezing point depression determined on the supernatant fluid. The amount of water added to the hypertonic solutions by the red cells was calcuated from this freezing point depression. For each decrease in the freezing point of -0.093°C. of the surrounding solution red cells gave up approximately 5 ml. of water per 100 ml. of red cells in the range of -0.560 to -0.930°C. Beyond -0.930°C. the amount of water given up by 100 ml. of red cells fits best a parabolic equation. The maximum of this equation occurred at a freezing point of the hypertonic solution of -2.001°C. at which time the maximum amount of water leaving the red cells would be 39.9 ml. per 100 ml. of red cells. The data suggest that only about 43 per cent of the red cell water is available for exchange into solutions of increasing tonicity.
Correspondence re: Kawano N, Inayama Y, Nagashima Y, Miyagi Y, Uemura H, Saitoh K, et al. Desmoplastic small round-cell tumor of the paratesticular region: report of an adult case with demonstration of EWS and WT1 gene fusion using paraffin-embedded tissue. Mod Pathol 1999;12:729-34.

Correspondence Re: Kawano N, Inayama Y, Nagashima Y, Miyagi Y, Uemura H, Saitoh K, et al. Desmoplastic Small Round-Cell Tumor of the Paratesticular Region: Report of an Adult Case with Demonstration of EWS and WT1 Gene Fusion using Paraffin-Embedded Tissue. Mod Pathol 1999;12:729–34.
A review of regression diagnostics for behavioral research

Influential data points can affect the results of a regression analysis; for example, the usual sum mary statistics and tests of significance may be misleading. The importance of regression diagnostics in detecting influential points is discussed, and five statistics are recommended for the applied researcher. The suggested diagnostics were used on a small dataset to detect an influen tial data point, and the effects were analyzed. Colinearity-based diagnostics also are discussed and illustrated on the same dataset. The non- robustness of the least squares estimates in the presence of influential points is emphasized. Diagnostics for multiple influential points, multi variate regression, multicolinearity, nonlinear regression, and other multivariate procedures also are discussed.
Vestibular and cochlear efferent neurons in the monkey identified by immunocytochemical methods.

Abstract Attempts were made to identify vestibular (VEN) and cochlear (CEN) efferent neurons in the squirrel monkey using retrograde transport of horseradish peroxidase (HRP) and immunocytochemical methods. HRP implants in the ampulla of the lateral semicircular duct retrogradely labeled cells of VEN bilaterally and some cells of CEN. VEN located lateral to the rostral part of the abducens nucleus formed a compact collection of cells, all of which were immunoreactive only to antisera for choline acetyltransferase (ChAT). CEN, identified by immunoreactivity to ChAT were located at the hilus of the lateral superior olive (LSO), along the lateral border of the LSO and sparsely near lateral parts of the ventral trapezoid nucleus (VTN). A small number of cells and fibers near the border of the VTN and lateral to the LSO were immunoreactive for leucine enkephalin (L-ENK). Fibers immunoreactive for L-ENK also were identified in the hilus of the LSO. No cells of the superior olivary complex were immunoreactive for antisera to ChAT, L-ENK, substance P, γ-aminobutyric acid or glutamic acid decar☐ylase. Cells of VEN and CEN can be identified by their immunoreactivity to ChAT, and some cells and fibers of CEN also contain L-ENK.
Determining the Causes of Seasonal Variation in Pavement Friction: Observational Study with Datapave 3.0 Database

Large amounts of money are spent by departments of transportation to provide adequate pavement skid resistance, yet the mechanics of pavement friction are poorly characterized and not fully understood. Seasonal variations in skid resistance are often observed, and in some cases these variations may be large enough to significantly affect highway safety. This paper assesses two common theories for the cause of seasonal variations in skid resistance from the perspective of the conservation of energy to understand their influence on highway skid resistance. One theory states that the seasonal variations in skid resistance occur because snowfall removal operations increase microtexture, which is then worn away throughout the summer. The other theory states that seasonal variations are caused by seasonal differences in pavement temperature. This paper analyzes the Datapave 3.0 friction data to examine the extent to which snowfall removal operations and pavement temperatures influence highway skid resistance. T...
Congenital polyp of the verumontanum

A congenital polyp of the verumontanum in a 5-year-old boy with urinary retention is presented. The diagnosis was made by voiding cystourethrogram.
The problem of moments on polytopes and other bounded regions

Abstract The problem of moments is considered for polytopes in R d and other bounded regions specified piecewise by curves of the form c1x1α1+⋯+cdxdαd=c0. Necessary and sufficient conditions are suggested by a simple geometric observation. For some choices of c1,…,cd and α1,…,αd, these conditions reduce to the conditions of Hausdorff for the unit interval, of Hildebrandt and Schoenberg for the unit square and of Dale for the unit simplex in R 2 , whereas for other choices new conditions are required. The proofs are obtained using probabilistic techniques.
Copyright Policies and the Deciphering of Fair Use in the Creation of Reserves at University Libraries

This paper stems from the results of a systematic study of research library policy regarding application and interpretation of copyright law to reserves and electronic reserves. A thorough legal framework is provided from which the study's results are interpreted, and suggestions for research library compliance are provided.
Health Research in Africa: Priorities, Promise, and Performance

I am delighted to participate at this conference because it gives me the opportunity of acknowledging the contributions of individuals, institutions and agencies who have dedicated their skills and resources to the fight against death, disease, and disability in developing countries. I am particularly pleased to join in congratulating Dr. Ken Warren, not only for his direct contributions as a research scientist on tropical diseases, but more importantly for his inspiration and support, which has encouraged and enabled many others to work on these problems. I have been asked specifically to provide an African perspective and I would like to examine the subject of health research in Africa by reviewing the subject in three historical periods: (a) the colonial era, (b) the post-independence period, and (c) the future.
Phenylephrine-induced antinociception: investigations of potential neural and endocrine bases.

Abstract Acute hypertensive states can produce antinociception, largely via unknown mechanisms. The aim of the present series of experiments was to examine potential hormonal and neural bases of analgesia induced by i.v. infusion of the pressor (hypertensive) agent phenylephrine. All rats were implanted with right jugular and left carotid cannulae for phenylephrine infusion and blood pressure/heart rate monitoring, respectively, and were tested approximately 24 h later in the unanesthetized state. The tail-flick test was used to measure responsivity prior to, during, and after phenylephrine infusion. Potential adrenal and pituitary contributions to phenylephrine-induced antinociception were examined, respectively, by physical disruption of adrenal blood flow and pharmacological suppression of pituitary activation. Acute block of all adrenal hormones, via closure at the time of testing of pre-implanted adrenal ligatures, did not block phenylephrine antinociception. However, pharmacological suppression of pituitary activation via pretreatment with the synthetic glucocorticoid dexamethasone abolished phenylephrine antinociception. Intriguingly, dexamethasone had no noticeable effect on urination prior to phenylephrine administration, yet only dexamethasone-treated rats exhibited copious urination during phenylephrine infusion. This suggests that the hypertensive agent phenylephrine releases vasopressin from the posterior pituitary terminals of the paraventricular hypothalamus (PVH) in a dexamethasone-suppressible manner, possibly via the known baroreceptor-nucleus tractus solitarius (NTS)-PVH link. Since (1) bilateral lesions of the spinal cord dorsolateral funiculus (DLF) were shown in the current study to abolish phenylephrine antinociception, (2) PVH is known to send vasopresinergic projections to the spinal cord via the DLF, and (3) intrathecal vasopressin produces antinociception via V1-like vasopressin receptors, the effect of an intrathecal V1 vasopressin antagonist was tested on phenylephrine-induced antinociception. The V1 vasopressin antagonist blocked phenylephrine antinociception, suggesting that phenylephrine antinociception may be mediated by a baroreceptor-NTS-PVH-DLF circuit leading to vasopressin release at spinal levels.
Performance Measurements of Pavement Matting Systems by Full-Scale Testing over Differing Soil Strengths

The focus of this work was to evaluate the use of commercially available matting systems to sustain C-130 and C-17 transport aircraft loads over soil bases having different California bearing ratio (CBR) ranges. Test sections were constructed using three range of CBR: high (CBR=40–50), medium (CBR=8–10), and low (CBR=5–6). Testing began with the C-130 load cart and six different matting systems. The C-130 was the lesser of the two aircraft loads examined and this initial testing was used as an "elimination round" for the various matting systems chosen. Matting systems deemed suitable for the C-130 were further tested under the C-17 load cart. Systems were evaluated based on logistical and assembly requirements, mat damage sustained during traffic, and accumulated deformation of the mats and soil during traffic. The latter are shown in line plots of passes versus plastic rut formation. Summary information on each matting system tested and the test sections themselves is presented. Conclusions on the matting systems tested and their application are discussed.
The epithelial tight junction: structure, function and preliminary biochemical characterization.

The tight junction, or zonula occludens (ZO), forms a semi-permeable barrier in the paracellular pathway in most vertebrate epithelia. The ZO is the apical-most member of a series of intercellular junctions, collectively known as the junctional complex, found at the interface of the apical and lateral cell surface. This structure not only restricts movement of substances around the cells, but may also serve as a ‘fence’ acting to maintain the cell surface compositional polarity characteristic of epithelial cells. The morphology and physiology of the ZO have been well documented and are briefly reviewed here. The biochemistry of this important intercellular junction remains largely unknown, although a tight junction-specific polypeptide called ‘ZO-1’ has recently been identified. Preliminary observations regarding the role of this peripheral phosphoprotein in the biology of the ZO are presented.
Normal childhood developmental patterns in skull bone marrow by MR imaging.

To establish the normal developmental pattern of skull bone marrow in children by MR imaging, sagittal T1-weighted MR skull images of 324 normal children (newborn to 18 years) were reviewed. Bone marrow intensity was assigned four gradations as compared with that of muscle and fat on the same image. Bone marrow became isointense with fat (yellow marrow) at a mean age ±S.E.M. (in years) of 8.5±0.24 in sphenoid, 9.1±0.29 in mandible, 9.3±0.28 in hard palate, 9.7±0.26 in frontal, 11.0±0.26 in squamous occiput, 11.5±0.28 in parietal, and 11.9±0.24 in basiocciput. There is a strong correlation between age and marrow intensity by Spearman analysis (p<0.001): hard palate 0.64, mandible 0.61, parietal 0.42, sphenoid 0.70, cervical spine 0.50, basi-occiput 0.58 and occiput 0.52. Two consistent overall patterns of red-yellow marrow conversion were observed. Bone marrow became isointense with fat prior to pneumatization of the paranasal sinuses. Marrow conversion in the bones of the face occurred before those of the calvarium in a specific pattern. There was no significant sex difference in the pattern or rate of marrow conversion. These normative data are necessary to evaluate the immature skull by MR imaging in disease states.
The structure of limit measures and their supports on topological semigroups

Given a sequence of measures (μ n ) on a topological semigroupS, a measure λ onS is called a tail limit of (μ n ) if for some subsequence of integers (n i ),\(\mu _{k,n_i } = \mu _{k + 1} * \cdot \cdot \cdot *\mu _{n_i } \) converges weakly to ν k for allk and λ is a weak limit point of the sequence (ν k ). The main theorem of this paper characterizes the supports of the tail limits on compact completely simple semigroups. Some applications of the theorem and various open problems are discussed.
A New Fatigue Testing Apparatus Model and Parameter Identification

Recently, a novel fatigue testing rig was designed and constructed to investigate the interplay between a fatigue crack evolution and structural dynamics. The aim of this study is to build a simple nonlinear spring-mass-damper model for this testing apparatus and identify all related parameters. A set of forced vibration tests were conducted with different hardware configurations and excitation signals to understand dynamic properties of different components of the rig and present nonlinearities. The system parameters were identified using standard modal analysis and nonlinear system identification approaches.Copyright © 2010 by ASME
INTRAVENOUS AMIODARONE : ANOTHER OPTION IN THE ACUTE MANAGEMENT OF SUSTAINED VENTRICULAR TACHYARRHYTHMIAS

Two timely articles published in this volume of Circulation by Scheinman et al1 and Kowey et al2 present data from recently completed trials confirming the efficacy of intravenous amiodarone in life-threatening ventricular tachyarrhythmias. Intravenous amiodarone has recently received Food and Drug Administration approval for the acute treatment and prevention of ventricular fibrillation (VF) and hemodynamically destabilizing ventricular tachycardia (VT) refractory to other therapy. The above-mentioned two trials were performed in severely ill patients who had life-threatening ventricular arrhythmias not controlled by several other intravenous antiarrhythmics. The mean age of the patients in these studies was in the 60-year range, 75% of the patients were men, the mean ejection fraction was 31%, 81% had had a prior myocardial infarction, 19% were on ventilator support, and 23% were on balloon pump support. Therefore, these patients were elderly, had severe ischemic structural heart disease and left ventricular dysfunction, and all the patients had hemodynamically destabilizing VT, incessant VT, and/or VF. The poor prognosis of this population limited the study design: (1) it was unethical to consider a placebo control group; (2) supplemental bolus doses were permitted to prevent recurrence of ventricular tachyarrhythmias; (3) open-label therapy was permitted even after double-blind therapy in attempts to save patients from dying; and (4) given the limitations of the enrollment criteria, a large number of centers were required for enrollment. A prior study3 using doses of 500, 1000, and 2000 mg every 24 hours demonstrated that all of these doses were about equally effective in treating ventricular tachyarrhythmias. A dose-related increase in hypotension was noted at higher doses. Therefore, although intravenous amiodarone at these doses appeared to have some efficacy, no effective dose range had been established to guide dosing in …
Generalized Binomial Regression Model

The generalized negative binomial distribution has been found useful in fitting over-dispersed as well as under-dispersed count data. We define and study the generalized binomial regression model which is used to predict a count response variable affected by one or more explanatory variables. The methods of maximum likelihood and moments are given for estimating the model parameters. Approximate tests for the adequacy of the model are considered. The generalized binomial regression model has been applied to two observed data sets to which binomial regression model was applied earlier.
A novel anaerobic needle inoculator for strict obligate anaerobic bacteria

An inoculating needle for picking and transferring colonies of strict anaerobic bacteria was built. A self-refilling syringe was adapted to carry a stainless steel needle within the cannula, and a tee junction allowed continuous flushing with dioxygen-free gas.
Gemfibrozil-Warfarin Drug Interaction Resulting in Profound Hypoprothrombinemia

The following describes a patient on a stable regimen of warfarin who developed severe hypoprothrombinemia and bleeding 4 weeks after starting gemfibrozil. Despite a warning by the manufacturer, only one report of this interaction has been published in the literature. This interaction may be overlooked by clinicians, which may result in a serious bleeding risk for patients on warfarin.
Catecholaminergic systems in the zebrafish. I. Number, morphology, and histochemical characteristics of neurons in the locus coeruleus.

The locus coeruleus is a noradrenergic nucleus located in the isthmal tegmentum. In mammals, it contains several thousand neurons that have diverse projection patterns and contain various neuropentides. In fishes, this nucleus contains few neurons. This study attempts to define and quantify morphological types of locus coeruleus neurons, and search for neurochemical subpopulations in the zebrafish. In this fish, the locus coeruleus contains between 3 and 10neurons, and most nuclei contain between 5 and 8 cells. Nuclei in more inbred lines of fish have a narrower range of neurons. The difference in neuron number between the two sides of the same brain is small, but only 24% of the brains have identical numbers on both sides. These observations suggest that there is a two-step control of neuron number: the genetic constitution of the fish determines the approximate number of cells, while epigenetic factors determine the final number. Based on dendritic orientation, three types of cells are identified: (1) V type, neurons with only ventrally projecting dendrites; (2) L types, neurons with only laterally projecting dendrites; and (3) VL type, neurons with both ventrally and laterally projecting dendrites. Over 65% of the neurons are of the V type; some nuclei have V type; some nuclei have V type cells only. There is a correlation between the total number of neurons and the ratio of each cell type. In nuclei with five cells or fewer, over 80% of the neurons are V type; higher percentages of the other two types are seen in nuclei with 6 or more neurons. The dendritic morphology and orientation suggest that various types of neurons may receive different inputs. Cholinesterases are not detectable in locus coeruleus neurons. Immunocytochemical staining for a number of neuropeptides also fails to demonstrate detectable levels. Neuropeptide Y is present in some cell abutting the locus coeruleus, but these are probably not catecholamine-containing neurons. Some neurons contain choline-acetyltransferase. These observations suggest that locus coeruleus neurons of the zebradish may be morphologically and neurochemically heterogeneous. © 1994 Wiley-Liss, Inc.
An inequality relating the regulator and the discriminant of a number field

Abstract Let K be a number field of degree d with regulator R K and absolute discriminant D K . Let r ( K ) be the rank of the unit group in K , and let p ( K ) be the maximum of r ( k ) as k ranges over proper subfields of K . We prove R K > c d ( log γ d D K ) r(K)−ρ(K) for constants c d , γ d > 0 depending only on d .
Activity in Human Frontal Cortex Associated with Spatial Working Memory and Saccadic Behavior

We examined, with event-related fMRI, two hypotheses about the organization of human working memory function in frontal cortex: (1) that a region immediately anterior to the frontal eye fields (FEF) (superior frontal cortex, SFC) is specialized for spatial working memory (Courtney, et al., 1998); and (2) that dorsolateral prefrontal cortex (PFC) plays a privileged role in the manipulation of spatial stimuli held in working memory (Owen, et al., 1996; Petrides 1994). Our delayed-response task featured 2-D arrays of irregularly arranged squares that were highlighted serially in a random sequence. The Forward Memory condition required maintenance of the spatio-temporal sequence, the Manipulate Memory condition required reordering this sequence into a new spatially defined order, the Guided Saccade condition required saccades to highlighted squares in the array, but no memory, and the Free Saccade condition required self-paced, horizontal saccades. The comparison of fMRI signal intensity associated with 2-D saccade generation (Guided Saccades) versus fMRI signal intensity associated with the delay period of the working memorials condition revealed no evidence for greater working memory-related activity than saccade-related activity in SFC in any individual subject, nor at the level of the group, and greater 2-D saccade than delay-period activity in three of five subjects. These results fail to support the hypothesis that spatial working memory-related activity is represented preferentially in a region of SFC anterior to the FEF (Courtney, et al., 1998). The comparison of maintenance versus manipulation of spatio-temporal information in working memory revealed significantly greater activity associated with the latter in dorsolateral PFC, but not in ventrolateral PFC or in SFC. These results suggest that the delay-related function of SFC is limited to the maintenance of spatial information, and that this region does not support the nonmnemonic executive control functions supported by dorsolateral PFC. These results also indicate that the preferential recruitment of dorsolateral PFC for the manipulation of information held in working memory applies to tasks employing spatial stimuli, as well as to tasks employing verbal stimuli (D'Esposito, et al., 1999); Petrides et al., 1993; Postle et al., 1999).
Excitation of thin elastic membranes by momentum of laser light

Abstract We demonstrate here a technique of using short energetic infrared laser pulses for imparting of momentum to excite mechanical oscillations in thin elastic membranes of polystyrene. The experimentally measured frequencies of oscillation agreed well with calculated values for the normal modes. The method offers a convenient way of studying elastic properties in thin films.
Properties of a new liquid desiccant solution—Lithium chloride and calcium chloride mixture

Abstract Desiccants, broadly classified as solid and liquid desiccants, have the property of extracting and retaining moisture from air brought into contact with them. By using either type, moisture in the air is removed and the resulting dry air can be used for air-conditioning or drying purposes. Because of its properties, lithium chloride is the most stable liquid desiccant and has a large dehydration concentration (30% to 45%), but its cost is relatively high ($9.00–13.00 per kg). It is expected that lithium chloride will reduce the relative humidity to as low as 15%. Calcium chloride is the cheapest (45 cents per kg) and most readily available desiccant, but it has the disadvantage of being unstable depending on the air inlet conditions and the concentration of the desiccant in the solution. To stabilize calcium chloride and to decrease the high cost of lithium chloride, the two can be mixed in different weight combinations. The main objective of this research is to measure the physical properties of different combinations of this mixture such as density, viscosity, and vapor pressure which are necessary for analysis of heat and mass transfer in a packed tower desiccant-air contact system. The solubility of this new liquid desiccant under certain temperature-concentrations will also be studied.