cssi/SciSciGPT-SciSciNet huggingface dataset:
Explaining category-related effects in the retrieval of conceptual and lexical knowledge for concrete entities: operationalization and analysis of factors

Category-related effects in the retrieval of conceptual and lexical knowledge for concrete entities have been well documented in lesion studies, and also with functional imaging and electrophysiological approaches. For example, brain-damaged subjects may be impaired in the ability to recognize or to name animals but not tools, or the opposite pattern may obtain. One reason for these dissociations is that different patterns of defects tend to be caused by distinct lesion profiles, suggesting a relative tendency for certain neural systems to be involved in category-related knowledge. But we and others have also hypothesized that a variety of traits of concrete entities co-determine category-related dissociations. Such traits ('factors') include homomorphy (similarity of form), familiarity, value to perceiver, manipulability, characteristic motion, characteristic sensory modality of transaction (vision, touch, hearing), and typical age of acquisition. It is our view that the mix of factors relative to different conceptual categories plays a key role in the neuroanatomical distribution of records for those different categories, and is thus behind the systematic correlations between certain retrieval defects and damage to certain neural systems [12, 52]. In this study, we operationalized these factors and analyzed their intercorrelations. Stimuli were slides of 215 items from the conceptual categories of animals, fruits/vegetables, tools/utensils, vehicles, and musical instruments. The factors were operationalized on the basis of ratings obtained from 227 normal control subjects and on the basis of computer analyses of the digitized outlines of the stimuli. Principal components analysis revealed that 81% of the variability across items could be accounted for by three components: Component 1 (practically useful, common items): high value to perceiver, tactile mode of transaction, high familiarity, low age of acquisition; Component 2 (homomorphic, non-manipulable items): high homomorphy, low characteristic motion and manipulability; Component 3 (items with characteristic sound): hearing mode of transaction, highly distinctive sounds. In another analysis, we found that the categories of animals versus tools/utensils differed significantly on the factors of homomorphy, familiarity, value, manipulability, characteristic motion, and touch. The factor structure we identified in this study may help explain category-related performance defects in brain-damaged subjects. The results lend support to our proposal that systematic differences in physical characteristics and contextual specification of concrete entities constitute a driving force behind the regionalization of neural systems related to the acquisition and retrieval of conceptual and lexical knowledge.
Economic and Social Indicators for the Farm Sector: Discussion

The topic of this session, the measurement of the social and the economic welfare of the farm sector, is extremely important at a time when major changes in the farm sector and in agricultural policy are being discussed. We had hoped to come here to discuss two papers which would make important intellectual contributions to this field. Unfortunately, our expectations were not realized, and we were somewhat disappointed in the papers. In our judgment, neither of these papers is of sufficient scope or depth to pass the peer review of a reputable journal; however, the issues raised by these papers are important and deserve discussion.
On the Transformation of light into Heat in Solids. I

Starting from the analogy between a crystal and molecule, it is shown that the electronic excitation, forming the first step in the process of light absorption, is not confined to a particular atom, but is diluted between all of them in the form of "excitation waves," similar to sound waves which are used to describe the heat motion in the same crystal. Owing to the interaction between the atoms the excitation state is split up into substates whose number is equal to the number of atoms $n$ (excitation multiplet). By superposing several excitation waves "excitation packets" can be constructed representing the travelling of the excitation state from one atom to another. To each excitation sub-state there corresponds a definite crystal structure (lattice constant, vibration frequencies) slightly different from that of the normal, and giving rise to slightly different vibrational states. This influence of the excitation on the vibrational states provides an indirect coupling between them, which allows the excitation energy to be shared between a few hundred heat-oscillators with practically no direct coupling nor anharmonicity in a radiationless transition which forms the second state of the process of light absorption.
Conversion of laser phase noise to amplitude noise in a resonant atomic vapor: The role of laser linewidth

When laser light propagates through a resonant medium, the transmitted beam can exhibit excess intensity noise [amplitude modulation (AM)]. In a semiclassical description of the phenomenon, laser phase noise (PM) induces fluctuations in the medium's electric susceptibility, which in turn cause fluctuations in the transmitted intensity. The process provides an efficient means for PM-to-AM conversion, and intuition suggests that large linewidth lasers should exhibit much greater PM-to-AM conversion than narrow linewidth lasers. Here we measure the relative intensity noise (RIN) for two diode lasers whose linewidths $\ensuremath{\Delta}{\ensuremath{\nu}}_{L}$ differ by more than ${10}^{2},$ after the lasers have propagated through a resonant rubidium vapor. Though the RIN of the narrow linewidth laser is only reduced by a factor of about 6 compared to the broad linewidth laser, our results are nonetheless consistent with numerical simulations of the PM-to-AM conversion process. In particular, both computation and analytical theory indicate that RIN is a nonlinear function of $\ensuremath{\Delta}{\ensuremath{\nu}}_{L}.$ For single-mode laser linewidths less than the atomic dephasing rate, RIN increases like $\sqrt{\ensuremath{\Delta}{\ensuremath{\nu}}_{L}},$ while for linewidths greater than the atomic dephasing rate RIN is a decreasing function of $\ensuremath{\Delta}{\ensuremath{\nu}}_{L}.$
Characterization of some biological specimens using TEM and SEM

The advent of novel techniques using the Transmission and Scanning Electron Microscopes improved observation on various biological specimens to characterize them. We studied some biological specimens using Transmission and Scanning Electron Microscopes. We followed negative staining technique with Phosphotungstic acid using bacterial culture of Bacillus subtilis. Negative staining is very convenient technique to view the structural morphology of different samples including bacteria, phage viruses and filaments in a cell. We could observe the bacterial cell wall and flagellum very well when trapped the negative stained biofilm from bacterial culture on a TEM grid. We cut ultra thin sections from the fixed root tips of Pisum sativum (Garden pea). Root tips were pre fixed with osmium tetroxide and post fixed with uranium acetate and placed in the BEEM capsule for block making. The ultrathin sections on the grid under TEM showed the granular chromatin in the nucleus. The protein bodies and large vacuoles with the storage materials were conspicuous. We followed fixation, critical point drying and sputter coating with gold to view the tissues with SEM after placing on stubs. SEM view of the leaf surface of a dangerous weed Tragia hispida showed the surface trichomes. These trichomes when break on touching releases poisonous content causing skin irritation. The cultured tissue from in vitro culture of Albizia lebbeck, a tree revealed the regenerative structures including leaf buds and stomata on the tissue surface. SEM and TEM allow investigating the minute details characteristic morphological features that can be used for classroom teaching.
Asian/Pacific Islander Women in Medical Education: Personal and Professional Challenges.

Purpose: The purpose of this qualitative study was to identify the complex issues facing Asian/Pacific Islander (API) women students at one Midwestern medical school as they subjectively experience their medical training. Of particular interest was how students navigated family influences, career planning, and ethnic and gender stereotypes. Summary: Sixty-five percent of the students reported that their parents exerted various degrees of encouragement or pressure to enter medicine. The remaining students said that the decision was entirely theirs (20%) or that the decision had been made for them (15%). Many reported the larger Asian "community" as a source of influence. A slight majority of students thought they were perceived by faculty as being "quiet," often too quiet. With only 1 exception, all of the students believed that their cultural identity influenced their specialty choice. Stressors reported by students centered on competition, achievement, and formation of intimate relationships (i.e., datin...
Effects of bison on willow and cottonwood in northern Yellowstone National Park

On the northern ungulate winter range of Yellowstone Park, willow (Salix spp.) and cottonwood (Populus angustifolia and Populus balsamifera) have increased in height and cover in some places since the reintroduction of wolves (Canis lupus) and the subsequent changes in elk (Cervus elaphus) behavior and population densities. However, in the Lamar Valley, an important part of this winter range, many plants are still intensively browsed and recruitment has been limited. As elk numbers have declined and their distribution has changed in recent years, bison (Bison bison) have increased on the northern range. To distinguish bison effects from those of elk, we measured browsing that occurred in summer. We found average summer browse rates of 84% for willow and 54% for cottonwood seedlings in the summer of 2010, demonstrating that bison have become significant browsers in the Lamar Valley. Plants were increasing in size except where intensively browsed by bison, suggesting that a release from elk browsing has occurred, and that a trophic cascade is occurring from wolves to plants, mediated by both elk and bison. Release of bison from competition with elk, low levels of predation on bison, and lack of opportunity for migration and range expansion may be factors contributing to a high concentration of bison, with resulting effects on plant communities and biodiversity.
Bilirubin levels in subarachnoid clot and effects on canine arterial smooth muscle cells.

Previous studies have suggested that bilirubin is a potential contributor to cerebral vasospasm. The purpose of this investigation was to determine whether bilirubin accrues in subarachnoid clot, whether its vasoconstrictive effect could involve a direct action on arterial smooth muscle cells, and, if so, whether bilirubin affects their Ca2+ uptake. Subarachnoid clots were analyzed for bilirubin using high-performance liquid chromatography. The length and 45Ca2+ uptake of vascular smooth muscle cells enzymatically dissociated from canine carotid arteries were measured before and after exposure to bilirubin solution. Additional experiments were conducted on cultured smooth muscle cells from canine basilar artery and on ATP-depleted cardiac myocytes. Mean +/- SE bilirubin concentration in experimental clot was 263 +/- 35.7 mumol/L. Vascular smooth muscle cells exposed to bilirubin showed progressive shortening (P < .01) and an increased uptake of 45Ca2+ (P < .001). Contraction was prevented by Ca(2+)-free media but not by verapamil. Experiments with heart myocytes showed that bilirubin caused an increased uptake of 45Ca2+ but not of [14C]sucrose. The results indicate that bilirubin accrues in subarachnoid clot, that it exerts a direct constrictive effect on arterial smooth muscle cells, and that this effect is associated with an increased uptake of Ca2+. Studies on heart myocytes suggest that the Ca2+ uptake induced by bilirubin could be due to a selective increase in membrane permeability to Ca2+.
Effect of strain amplitude on fatigue in copper single crystals

Abstract A study of fatigue in copper single crystals of [100] axial orientation has been made. The crystals were run in alternating torsion at surface shear strains between ±0.001 and ±0.011. A sharp break in the S-N curve dividing it into a low amplitude (F) region and high amplitude (H) region together with metallographic changes is evidence for different fatigue mechanisms in the two regions. In the F-region slip on primary systems dominates the fatigue progress. In the H-region interaction of slip systems is important. The formation of deformation bands and appearance of secondary slip for cyclic straining in this range show characteristics similar to those of unidirectional straining.
Role of protogen in the oxidation of pyruvic acid.

SummaryProtogen has been found to be essential for the acetylation reaction, but not for the oxidative phase, of pyruvate oxidation, when assayed in a purified pyruvic oxidase preparation from the ciliate Tetrahymena geleii S.
Imaging of Small Airway Disease (SAD)

This article comprehensively reviews and illustrates the imaging features of small airway diseases. The authors discuss the imaging findings of small airway diseases in general and how to differentiate them from other findings that can be confused with small airway diseases. The authors also discuss the features that aid in diagnosing specific diseases that affect the small airways.
Loss of high-frequency brain electrical response to thiopental administration in alzheimer's-type dementia

Abnormal brain regions generate proportionately less high-frequency (beta) activity than nonpathological regions, a phenomenon accentuated by barbiturate administration. Using quantitative electroencephalography we examined power in the 20- to 28-Hz band in patients with dementia of the Alzheimer's type (DAT), vascular dementia (VaD), and normal elderly controls (CON) following an IV bolus of thiopental (0.5 mg/kg). Compared to both CON and VaD subjects, DAT subjects showed a marked loss of beta power elicited across the cortex, with largest differences noted in the frontal region. Losses were most significant for the peak response recorded at 30 to 90 s postinjection and persisted during the 5-minute follow-up period. We hypothesize that differences in this electrocerebral response reflect differences in the underlying neuropathology of DAT and VaD subjects. A thiopental challenge may be well suited for the in vivo assessment of brain function in dementias characterized by prominent cortical pathology.
Short-term memory in children with sickle cell disease: executive versus modality-specific processing deficits.

Abstract Prior research has identified a number of areas of cognitive deficit among children with sickle cell disease (SCD), including decrements in memory span and working memory. The present study examined short-term memory span and working memory performance among children with SCD ( n = 25) and demographically matched comparison children ( n = 25) using digit span, spatial span, and the self-ordered pointing test. Children with SCD showed difficulties only for digit span-backward. Additional cognitive ability measures administered indicated auditory processing was an area of deficit related to digit span-backward performance. The study suggests that modality specific deficits are one factor in short-term memory span for children with SCD. The cause of this deficit is unclear, but may involve both central and peripheral components of auditory processing.
INCIDENCE AND SEVERITY OF ROTAVIRUS AND ESCHERICHIA COLI DIARRHOEA IN RURAL BANGLADESH: Implications for Vaccine Development

In a 1 year study of diarrhoea in a village in rural Bangladesh, enterotoxigenic Escherichia coli (ETEC) were the most frequently detected enteropathogens; shigellae were the second most commonly detected enteropathogens and rotaviruses the third. ETEC and rotavirus were found in 31% of diarrhoea episodes experienced by children aged less than 2 years and in 70% of episodes associated with dehydration. Furthermore these two pathogens were identified in the stools of 77% of young children with life-threatening dehydration seen at a diarrhoea treatment centre. The association of ETEC and rotavirus with such a substantial proportion of cases of dehydrating diarrhoea suggests that immunoprophylaxis to reduce the high incidence of deaths from diarrhoea in developing countries may be feasible and that vaccine development should concentrate on these two enteropathogens.
CYCLOSPORINE, FK-506, RAPAMYCIN, AND OTHER IMMUNOMODULATORS

Immunomodulatory agents represent a unique group of therapies that are not biologics and have relatively specific, noncytotoxic effects on the immune system. Cyclosporine has been the most widely tested of the immunomodulatory agents and shown efficacy in a variety of autoimmune diseases as well as monotherapy in established rheumatoid arthritis. FK-506 and rapamycin, agents similar to cyclosporine, are being tested in human transplantation, with only arthritis studies having been done in animals. Tilomisole, imuthiol, and mycophenolate mofetil have been studied in limited rheumatoid arthritis trials with positive effects. Although more specific and with manageable short-term side effects, this group of therapies requires more studies to establish their efficacy and long-term safety.
California Court-Connected Mediation: Appreciating the Influence of Power and Processes

In this article, the author discusses the complex relational dynamics involved with child custody recommending counseling processes in California court-connected mediation sessions. The mediation process is viewed through a systemic lens, which allows for the appreciation of reflexive and recursive elements of power inherently present with all participants. A brief exploration is provided of how this reflexive use of power by participants influences the model of mediation used. Finally, suggestions for process improvements are made along with suggestions for areas of future research.
Some Applications of Order Statistics to Multivariate Analysis II

ABSTRACT Harter (1979) summarized applications of order statistics to multivariate analysis up through 1949. The present paper covers the period 1950–1959. References in the two papers were selected from the first and second volumes, respectively, of the author's chronological annotated bibliography on order statistics [Harter (1978, 1983)]. Tintner (1950a) established formal relations between four special types of multivariate analysis: (1) canonical correlation, (2) principal components, (3) weighted regression, and (4) discriminant analysis, all of which depend on ordered roots of determinantal equations. During the decade 1950–1959, numerous authors contributed to distribution theory and/or computational methods for ordered roots and their applications to multivariate analysis. Test criteria for (i) multivariate analysis of variance, (ii) comparison of variance–covariance matrices, and (iii) multiple independence of groups of variates when the parent population is multivariate normal were usually deri...
Evidence that A8947 enhances pancreas growth via a trypsin inhibitor mechanism.

A8947 is a member of the sulfonyl urea class of compounds and is the active ingredient in a commercial broad leaf herbicide. This compound has been shown to produce pancreatic hypertrophy in rats, mice, and dogs. The objectives of this study were to investigate the mechanism(s) for the A8947 induction of pancreatic acinar cell hypertrophy and proliferation and to evaluate whether these pancreatic changes are reversible. A8947 was fed to male Crl:CD BR rats for up to 28 days (0, 300, 10,000, 30,000 ppm) or 56 days (0, 30,000 ppm). Rats were terminated on Test Days 7, 14, and 28 to assess the time course and dose response for the A8947-induced pancreatic changes, while rats terminated on Test Day 56 were used to assesss the reversibility of the pancreas effects at 30,000 ppm A8947. A8947 produced significant increases in pancreatic weight and acinar cell proliferation and diffuse acinar cell hypertrophy in 7 days at 10,000 and 30,000 ppm dose levels. By Day 14, absolute pancreas weights in the 10,000 and 30,000 ppm groups were maximally increased and remained at these levels throughout the study. In contrast, acinar cell proliferation in the 30,000 ppm group was still elevated at Test Day 14, but attenuated relative to the 7-day response, and returned to control levels by Test Day 28. No effects were observed at 300 ppm after a 28-day exposure period, while complete reversibility of A8947-induced pancreatic effects was demonstrated at 30,000 ppm following a 1-month recovery period (Test Day 56). Cholecystokinin (CCK) levels were increased by A8947 and closely followed the time course for pancreatic changes. MK-329, a specific CCKA receptor antagonist, completely ablated the ability of 30,000 ppm A8947 to increase pancreas weight following 7 days of exposure. A8947 did not bind the CCKA receptor in a receptor competition assay, negating any potential agonist mechanism. A8947 did, however, inhibit trypsin in vitro, suggesting a mechanism of action similar to that of raw soy protein, in which trypsin inhibition in vivo results in increased CCK levels followed by pancreatic acinar cell hypertrophy and proliferation.
Double Regge pole exchange and K−p backward scattering☆

Abstract An estimate of the double Regge exchange contribution to dσ/du (K−p) at u=0 suggests that a break in the energy dependence from the presently observed s−10 to an s−3 behavior should occur at about 5 GeV/c. Further tests of the model are discussed.
Symmetric‐key block cipher for image and text cryptography

Public-key cryptography has been widely accepted as the method in which data is encrypted, using algorithms such as the widely known and popularly used RSA algorithm. However, management of the public-key and its storage is an on-going issue. To avoid these problems the symmetric-key approach can be taken, where there is only one key and it must be kept secret. Presented in this paper is a new cipher based on symmetric-key cryptography, called the NASA/Kennedy Cipher (N/KC), and further designed as a block cipher using 128-bit blocks. The minimum key size is set at 128 bits with a maximum allowable of 2048 bits, modulus 2. The main focus of this work is encryption of image data for the purpose of protecting intellectual properties. However, empirical results are presented on N/KC's ability of encrypting and decrypting text data in the form of vectors and documents as well. © 2005 Wiley Periodicals, Inc. Int J Imaging Syst Technol, 15, 178–188, 2005
Biological applications of resonance Raman spectroscopy: haem proteins

Resonance Raman spectroscopy involves laser excitation within an absorption band of the sample. Certain vibrational modes, those which couple to the electronic transition, exhibit greatly increased Raman scattering in the resulting spectrum. Sensitivity approaches that of absorption spectrophotometry, while the high resolution characteristic of vibrational spectroscopy is preserved, even in solution at room temperature. If the resonant electronic transition is associated with a site of biological activity, then the technique offers a sensitive probe for structural features of the site. Haem proteins afford particularly informative resonance Raman spectra, with a rich assortment of porphyrin ring vibrations, which can be classified and analysed via their symmetry properties. Certain of these frequencies are sensitive to the structural concomitants of spin- and oxidation-state changes of the haem group. These can be used to monitor the structural consequences of ligation or electron transfer in haem proteins.
Transcriptional regulation of α-cell differentiation

The development of the endocrine pancreas and the differentiation of its five cell types, α, β, δ, e and pancreatic polypeptide (PP) cells, are a highly complex and tightly regulated process. Proper differentiation and function of α- and β-cells are critical for blood glucose homeostasis. These processes are governed by multiple transcription factors and other signalling systems, and its dysregulation results in diabetes. The differentiation of α-cells and the maintenance of α-cell function can be influenced at several stages during development and in the maturing islet. Many transcription factors, such as neurogenin 3 (Ngn3), pancreatic duodenal homeobox 1 (Pdx1) and regulatory factor x6 (Rfx6), play a crucial role in the determination of the endocrine cell fate, while other transcription factors, such as aristaless-related homeobox (Arx) and forkhead box A2 (Foxa2), are implicated in the initial or terminal differentiation of α-cells. In vivo and in vitro studies have shown that preproglucagon transcription, and therefore the maintenance of α-cell function, is regulated by several factors, including forkhead box A1 (Foxa1), paired box 6 (Pax6), brain4 (Brn4) and islet-1 (Isl-1). Detailed information about the regulation of normal and abnormal α-cell differentiation gives insight into the pathogenesis of diabetes, identifies further targets for diabetes treatment and provides clues for the reprogramming of α- to β-cells for replacement therapy.
AN AMINO ACID DELETION ASSOCIATED WITH THE IgG4b ALLOTYPE OF HUMAN IgG4 MYELOMA PROTEINS

SUMMARY Comparative aminoacid sequence studies were done on chymotryptic peptides from the Fc fragments of IgG1, IgG2, IgG4a and IgG4b human myeloma proteins. Eleven peptides were positioned within the Fc fragments of IgG4 proteins. While leucine was present at position 309 of the Fc fragment of the IgG4a protein, it was absent from the Fc fragment of the IgG4b protein.
Major cation gradients in DSDP interstitial waters: the role of diffusive exchange between seawater and upper oceanic crust

Abstract Interstitial water analyses from DSDP Legs 1–53 were surveyed to identify sites at which the dominant process supporting gradients of major seawater cations is alteration of the underlying oceanic crust. Sites with thin sediment cover are generally without gradients: sites with appreciable sediment accumulation are generally with gradients. The transition is probably the result of cessation of convective circulation within the sediments. A model is developed for the diffusive flux through an accumulating, unreactive sedimentary layer supported by continued reaction within the crust. The model is consistent with the observations provided that convection within the crust extends to depths > 1 km and that convective flow within the sediments ends once 100–150 m of sediment accumulates. The model suggests a steady state gradient inversely proportional to the sedimentation rate: this dependence is apparent in the data, however, some variation in the reaction rate is also required. Fluxes of Mg and Na are systematically related to the flux of Ca which because of its mobility serves as a tracer of hydrolysis of the basalt. When the Ca flux is low, the Mg flux serves as the principal sink for alkalinity produced during basalt hydrolysis. When the Ca flux is high, the Mg flux becomes diffusion-limited and Nabearing alteration phases must form. The fluxes resulting from these alteration reactions exert little influence on either the chemistry of seawater or that of the upper crust.
Corporate philanthropic practices

Abstract We study corporate philanthropy using an original database that includes firm-level data on dollar giving, giving priorities, governance, and managerial involvement in giving programs. Results provide some support for the theory that giving enhances shareholder value, as firms in the same industry tend to adopt similar giving practices and firms that advertise more intensively also give more to charity. But much of our evidence indicates that agency costs play a prominent role in explaining corporate giving. Firms with larger boards of directors are associated with significantly more cash giving and with the establishment of corporate foundations. Consistent with effective monitoring by creditors, firms with higher debt-to-value ratios give less cash to charities and are less likely to establish foundations. The empirical work considers the impact of industry regulation on giving and controls for state philanthropy laws and fiduciary responsibility laws.
Electron pairing and single electron tunneling in mesoscopic superconductors

The number of electrons N on a mesoscopic metallic island in weak tunneling contact with an electron reservoir is a good quantum number, with small fluctuations. If the island is superconducting, there is a physical distinction between even and odd values of N, because of the electron pairing in the BCS ground state. If N is odd, there must be at least one quasiparticle excitation above the energy gap Δ, whereas if N is even, all electrons can be paired. Below a certain temperature T∗ (typically ∼0.2 Tc), this distinction leads to a free energy difference F0(T) favoring N=even. In this paper, the experimentally observed consequences of this parity-dependent free energy will be discussed.
Androgen stimulated chemotherapy in the dunning R-3327 prostatic adenocarcinoma

This study was undertaken to determine whether hormonal stimulation followed by chemotherapy with a cell-cycle specific agent would improve the effectiveness of the chemotherapy in a prostatic adenocarcinoma model. One hundred Copenhagen rats were randomised into 5 equal groups and injected subcutaneously with 2×107 cells of Dunning G strain prostatic adenocarcinoma. The groups were treated in the following fashion: 1. sham operated controls, 2. castration, 3. castration and methotrexate, 4. castration, testosterone and methotrexate and 5. castration and testosterone. When the tumours became palpable, all animals received the surgery to which they were randomised. Subsequent hormonal and chemotherapy was started 1 week thereafter. Therapy was given for 5 consecutive days followed by a 16-day recovery period and then continued in a cyclical fashion. Serial measurements of animal weights and tumour size were obtained. Analysis of tumour growth was restricted to the first 29 days of therapy because of a rapid decline in animal survival beyond that point. The group treated with castration, testosterone, and methotrexate inhibited tumour growth more than any other group and was the only group that was significantly different from control (P<0.05).
Determination of cannabidiol in plasma by electron-capture gas chromatography.

Abstract A procedure was developed for the analysis of cannabidiol (CBD) in blood plasma. Tetrahydrocannabidiol was used as an internal standard and was added prior to extraction. The plasma extracts were derivatized with pentafluorobenzyl bromide and the product purified on a mini-column of Florisil. The pentafluorobenzyl derivatives were then analyzed by gas chromatography on a 5% OV-225 column using an electron-capture detector. A detection limit of 50 ng CBD per ml of plasma was observed. The procedure was used to study the plasma level of CBD after its oral and intravenous administration to monkeys.
Relinquishing Infertility: The Work of Pregnancy for Infertile Couples:

Although infertility has been described as an experience with long-term implications for the well-being of couples affected by it, few studies have examined any part of the aftermath of infertility. This article describes the ways in which infertility shapes the pregnancy course in couples who have struggled to conceive. The findings are drawn from 162 interviews conducted with 60 couples (41 infertile and a comparison group of 19 fertile) expecting a child, who were participants in a longitudinal field study involving both childbearing and adopting couples. During the course of the study, 63 pregnancies were observed. The core variable distinguishing the infertile from the fertile couples' pregnancies was relinquishing infertility. Beyond this variable, infertility emerged as important, but only one of a number of factors altering the experience of contemporary childbearing.
Ex vivo renal artery reconstructions: indications and techniques.

Abstract Ex vivo renal artery surgery has been reported by several investigators and has extended the role of revascularization in the treatment of lesions previously managed by nephrectomy alone. Several techniques are available for use, and selection of the most appropriate method can be tailored to the specific anatomy being managed. Our total experience included 27 kidneys that have been managed by ex vivo renal artery reconstruction. Lesions managed in this manner include two kidneys with renal artery stenosis and renal tumors, one kidney with a congenital branch arteriovenous malformation, and 24 kidneys with branch occlusive or aneurysmal disease from fibromuscular dysplasia. Postoperative angiography was performed in 22 cases and defined successful revascularization without technical error in 20 cases. One operative death occurred as a result of myocardial infarction. One patient required reoperation to control bleeding, and two patients had temporary acute tubular necrosis during the postoperative period. Techniques employed included ex vivo repair with autotransplantation to the iliac system (six kidneys), mobilization and perfusion without transection of the renal vein (10 kidneys), and ex vivo perfusion and repair with replacement into the original renal fossa (11 kidneys). The authors believe this latter technique of reconstruction to be preferable to autotransplantation for the usual patient undergoing ex vivo repair of complex renovascular lesions. (J VASC SURG 1986;4:546-52.)
Changes in structure and cover of a common property pine forest in Guatemala, 1954-1996.

Concern about increasing rates of deforestation of tropical forests has resulted in investigations into the viability of local land-use practices and communal forms of governance. The majority of people in Guatemala live in regions where primary forests are absent. Several secondary forests in the highly populated highlands of Guatemala are communally managed forests, and people depend on forest products from these secondary forests for their livelihood. This study examines changes in forest structure and coverage of a native Pinus oocarpa Schiede communally managed forest in San Jose La Arada, Chiquimula in eastern Guatemala from 1954-1996. The pine forest is a municipal-communal property. The municipality has title to the land, however the forests are communal property. Neither forest committees in the villages nor municipal government regulations establish communal management of the pine forest; instead there are customary rules in the villages that guide forest extraction. People from the surrounding villages extract fuelwood, ocote (resin-rich wood harvested from the tree trunk and used for kindling) and timber from the pine forest. The P. oocarpa forest is situated in a seasonally dry region with nutrient-poor and highly eroded soils. Aerial photographs from 1954 and 1987 were compared to estimated changes in forest cover. Changes in forest structure are based on data collected from stand inventories conducted in 1987 and 1996. The pine forest was reduced in area by 14.4%, from 12.39 km 2 in 1954 to 10.61 km 2 in 1987. Additionally, stand density and basal area were reduced by 12% and 41%, respectively, from 1987-1996. Fuelwood and timber for domestic use were not extracted at a sustainable rate between 1954 and 1996 from the communally managed pine forest in this study. A sustainable-use management plan, in which all villages surrounding the forest participate, is recommended to provide future forest products for the villages.
Photoreceptor spectral sensitivities and color correction

Lythgoe (1979) reviews evidence that photoreceptor spectral sensitivities in certain species are matched to the animal’s environment. The possibility that photoreceptors are chosen to optimize visual performances leads to the question, what choices of photoreceptor spectral sensitivities are best for various visual tasks? In this paper I review and critique previous work concerning optimal choices of receptors for certain color vision tasks
Uses and Gratifications of the Web among Students

This study was designed to explore how some students in ten public schools view the WWW and how their attitudes and opinions affect their use of this new medium in an educational context. An exploratory principal components analysis of forty use statements resulted in an eight factor solution. Additionally, student responses to a computer-administered survey instrument were collected and analyzed revealing significant differences in the way that students describe their use of the WWW. Gender, grade level, and amount of time spent using the WWW were used to create between-group comparisons of the WWW use categories that made up the computer-administered survey instrument. The final phase of data analysis was a content analysis of sites visited by students. A total of 123,071 URLs were collected from the computers used to administer the computer survey instrument. These were reduced to a total of 500 sites that were reviewed by media specialists. Students were found to be visiting commercial sites at a much higher proportion than those in other domains. Also, the commercial sites received the lowest rating for “suitability for academic research” of all the domain names. And while students reported their purpose for using the WWW as “research and learning” fifty-two percent of the time, the coders found only twenty-seven percent of the sampled sites to be “suitable” for that purpose.
Oxidation of thioanisole by peroxomolybdate in assemblies of cetylpyridinium chloride and methyltri-n-octylammonium chloride

Methyltri-n-octylammonium chloride (Aliquat 336) is sparingly soluble in water but is readily soluble with a 2-fold excess of micellized cetylpyridinium chloride (CPyCl), and the mixtures show breaks in plots of surface tension or electrolytic conductance against concentration indicative of a critical micelle concentration slightly lower than that of CPyCl. Micellization markedly increases 35Cl and 14N NMR line widths of CPyCl, but addition of NaCl reduces the 35Cl line width and addition of Aliquat increases it. Mixing Aliquat and CPyCl has little effect on their 14N line widths. Ion pairing in alcohol mixtures also increases 35Cl line widths. In water these mixed assemblies behave similarly to micelles of CPyCl as regards effects on rates and equilibria of interconversion of tri- and tetraperoxomolybdate ions, and oxidation of thioanisole by the latter, although it is slightly slower than in micelles of CPyCl. Despite differences in the hydrophobic regions, and relationships between amphiphilic structur...
Clinical impact of transesophageal echocardiography in the diagnosis and management of infective endocarditis

Transesophageal echocardiography (TEE) has assumed a prominent role in the diagnosis and management of infective endocarditis (IE). The impact of negative TEE findings on the management of patients suspected of having IE is not clear. To better understand how a negative TEE examination would influence patient management, the medical records of 93 consecutive patients undergoing TEE to evaluate for IE were examined. The influence of TEE was assessed based on changes in diagnosis, antibiotic therapy, or the need for surgical intervention during hospitalization. The negative predictive value of TEE was found to be 100% in native valves and 90% in prosthetic valves. The overall impact of negative TEE findings was significant in terms of final diagnosis and duration of antibiotic therapy (a negative TEE resulted in 60% reduction in antibiotic duration, p = 0.0001). These findings suggest that in patients with native heart valves, a negative TEE examination virtually excludes IE. In patients with prosthetic valves, a negative TEE significantly decreases the likelihood of IE but does not completely exclude the diagnosis; therefore, in this setting, a negative finding should be closely correlated with the clinical course.
The photodetachment cross section of the negative hydrogen ion

The photoionization cross section of the hydrogen negative ion is computed using a discrete-basis-set expansion to represent both the ground and continuum states of the system. This discrete-basis-set representation is used to construct an approximation to the dynamic polarizability, which in turn is used in an analytical continuation procedure for complex values of the frequency. This "discretization" of the continuum makes the method potentially applicable to larger systems, and a study of the basis-set dependence is made. The final results are in good agreement with more elaborate calculations and with experimental results. The dynamic polarizability in the normal dispersion region is also computed. I. INTRODUCTION The photoionization cross section of the hydrogen negative ion has been the subject of several calculations since Wildt' first suggested that it could be responsible for the visible and infrared opacity in the atmosphere of cooler late spectral type stars. Ghandrasekhar' and his co-workers pioneered these studies in a series of papers investigating the dependence of the cross section on the accuracy of the bound-state wave function. They also investigated the effect of the central field approximation for the free state. ' The importance of,taking into account exchange effects in the free wave function was first investigated by John' using the Hart-Herzberg 20-parameter wave function for the ground state and the "1s"exchange approximation continuum function. A number of subsequent calculations have appeared. Geltman' employed the 70-parameter bound-state wave function of Schwartz and variationally determined symmetrized continuum functions, containing terms corresponding to excited states of the hydrogen atom. This allowed him to treat both correlation and distortion of the residual hydrogen atom. Doughty et al. ' employed a close-coupling approach for using a Hartree-Pock eigenfunction expansion for the continuum states which included up to 3d atomic orbitals of the hydrogen atom. Bell and Kingston' used the method of polarized orbitals to obtain a representation of the continuum. More recently Ajmera and Ghung' used the variational method of Kohn-Feshbach to obtain free-state wave functions. A recent review of the photodetachment of H was given by Risley. ' While many of the above calculations have produced good results for H, they are generally not easily extended to large systems, first because such highly accurate wave functions are not available for systems with more electrons, and secondly because the generation of continuum functions by the methods used above becomes very cumbersome '0 Our interest is in developing a method w'hich could be equally applied to larger systems. Thus we use highly accurate wave functions and methods practicable for polyatomic molecules, and w'e avoid
Abstract time-dependent transport equations☆

Abstract We consider the abstract time-dependent linear transport equation as an initial-boundary value evolution problem in the Banach spaces Lp, 1 ⩽ p
In Vivo Detection of Cortical Plaques by MR Imaging in Patients with Multiple Sclerosis

BACKGROUND AND PURPOSE: In vivo detection of cortical lesions in patients with multiple sclerosis (MS) by MR imaging is hampered by several factors. Among them is the low contrast between small cortical lesions and surrounding cortical gray matter offered by present techniques. METHODS: T1-weighted 3D spoiled gradient-recalled-echo (SPGR) volumes and 2D fluid-attenuated inversion recovery (FLAIR) sequences of 22 patients with MS who had 12 monthly brain MR imaging examinations at 1.5T, using a quadrature head coil, were retrospectively analyzed. These serial studies were coregistered and averaged to generate a single high signal-to-noise ratio (SNR) mean image, which was used to identify cortical lesions. The means of 12 FLAIRs and SPGRs from 14 age- and sex-matched healthy volunteers were analyzed as well. RESULTS: No cortical lesions were found on images of healthy subjects. Eighty-six cortical lesions were identified in 13 (59.1%) patients, predominantly in the frontal lobe (73.3%); 23.3% of cortical lesions lay entirely in the cortex, whereas the remaining lesions invaded the white matter underneath. CONCLUSION: Averaging multiple SPGRs created a single high SNR volume, allowing identification of cortical lesions. Because data were obtained monthly for 1 year, the average image does not account for transient lesion activity. However, for cortical lesions that remained stable during this time, the findings are valid in demonstrating the importance of high SNR images for detecting cortical brain abnormalities in MS.
Improving MODFLOW's RIVER Package for Unsaturated Stream/Aquifer Flow

Saturated flow is typically assumed for seepage from a stream underlain by an alluvial aquifer. However, if the water table in an unconfined aquifer falls a sufficient distance below the streambed, the head losses in this less conductive layer will cause the region beneath the streambed to become unsaturated. Unsaturated flow transforms streams from constant head boundaries to constant flux boundaries, impacting not only the quantity of stream recharge but also biogeochemical transformations. The objective of this paper is to analyze the impact of unsaturated flow on stream/aquifer exchange. The modeling capabilities of one of the most commonly used groundwater flow models, MODFLOW, in simulating unsaturated stream/aquifer exchange is improved. The effects of unsaturated flow on MODFLOW predictions of aquifer drawdown and stream leakage are illustrated for hypothetical stream/aquifer systems.
Wavelet analysis of fractal point processes

The response patterns of chinchilla auditory nerve fibers were analyzed using the wavelet transform. Previous studies have shown that the responses display a fractal characteristic when observed over relatively long time intervals (>100-200 ms). Both spontaneous (non-driven) and acoustically driven responses of neurons in the auditory nerve display this behavior. The wavelet transform was used to quantify this fractal behavior by estimating the slope of the variance of the wavelet coefficients across several levels of resolution. The estimates were similar to the ones obtained using the Fano factor (variance to mean ratio of events). A wavelet analysis done on a doubly stochastic point process model of the responses of the auditory nerve gave similar results.
Detection of phototoxic activity in plant specimens associated with primary photosensitization in livestock using a simple microbiological test.

Ingestion of mushrooms is infrequently observed by owners and may be omitted from the initial history. When mushroom poisoning is suspected on the basis of histopathological lesions, additional history and tests may help to establish the diagnosis. Collection and identification of mushrooms from the animal’s environment will establish the types of mushrooms that the dog was potentially exposed to. Examination of vomitus, gastrointestinal contents, and/or feces for mushroom spores may provide definitive evidence of mushroom ingestion and possible identification of the genus and species. In human patients, early diagnosis is occasionally achieved by detection of amanitins in urine or other body fluids.” Due to delayed onset of clinical signs, patients usually receive only supportive and palliative treatment. The treatment for Amanita mushroom poisoning has recently been reviewed.” Unless treatment is initiated promptly after exposure and before significant amounts of toxin are absorbed, the final outcome of the case is dependent on the amount and type of mushroom ingested.