cssi/SciSciGPT-SciSciNet huggingface dataset:
Mechanically resolving noncovalent bonds using acoustic radiation force

The resolution of molecular bonds and subsequent selective control of their binding are of great significance in chemistry and biology. We have developed a method based on the use of acoustic radiation force to precisely dissociate noncovalent molecular bonds. The acoustic radiation force is produced by extremely low-power ultrasound waves and is mediated by magnetic particles. We successfully distinguished the binding of antibodies of different subclasses and the binding of DNA duplexes with a single-base-pair difference. In contrast to most ultrasound applications in chemistry, the sonication probe is noninvasive and requires a sample volume of only a few microliters. Our method is thus viable for noninvasive and accurate control of molecular bonds that are widely encountered in biochemistry.
Assessing Pulmonary Arterial Hypertension in Infants With Severe Chronic Lung Disease of Infancy: A Role for a Pulmonary Artery Catheter?

The treatment of pulmonary arterial hypertension (PAH) associated with chronic lung disease of infancy (CLDI) is becoming commonplace. However, an optimal approach to the monitoring of this treatment has not been clearly established, and data suggest that such therapy may not be without risk. This study assessed the feasibility and safety of pulmonary artery catheter (PAC) placement and its role in the management of PAH associated with CLDI. The medical records of 12 infants with CLDI requiring chronic mechanical ventilation who underwent PAC monitoring were reviewed. Data analyzed included demographics, hemodynamic data, PAH pharmacological therapy, respiratory support, echocardiographic data, sedation level, complications related to PAC use, and mortality. In this analysis, PAC placement and monitoring was found to be feasible, appeared safe, and was associated with the ability to wean inspired oxygen, decrease sedation, and titrate PAH therapy without untoward effect. However, no definitive conclusions can be drawn from this report given its small sample size and uncontrolled, retrospective design. It is hoped that these data will renew interest in PAC monitoring for CLDI and foster prospective study where its true value can be ascertained.
Identification of predictor and filter parameters by ARMA methods

The present paper describes procedures for recursive joint identification of the parameters of mixed autoregressive-moving-average models and for the determination of their order. The procedures given are subsequently extended to joint the estimation of the transition and the covariance parameters of single output and multi-output Kalman—Bucy filters in cases where both input and measurement noise sequences exist.
Quality of care: an overdue agenda.

In this issue of Pediatrics , Horbar and his colleagues1 report on variations in mortality across 62 of the neonatal intensive care units (NICUs) participating in the Vermont Oxford Network in 1991 and/or 1992. The fact that NICUs experience substantial variation in their mortality and complication rates in ways that are not explained by the distribution of the basic characteristics of the patient population like birth weight, gestational age, race, and gender is now a well-documented phenomenon.2-4 The difficulty has been in establishing the source of this variation. In this report, the investigators examine two potential sources of variation: the volume of patients as a proxy for experience, and presence of a training program as a marker of a teaching hospital. The concern about these particular factors reflects the rapid increase in the number of smaller NICUs in community hospitals outside the traditional large tertiary centers.5Although they find significant variability in mortality controlling for a broader array of risk factors, neither volume nor the presence of a residency program influences this variation. An older literature supports the conclusion of a survival advantage to infants born in a hospital with an NICU compared with hospitals without such units,6-8 but comparisons among hospitals with NICUs is much more recent. In this very limited literature, the results obtained by Horbar et al1 are somewhat at variance with two prior studies. In the study of Tarnow-Mordi and his colleagues,9 teaching hospitals perform better than nonteaching hospitals. The latter also appear …
Actin cytoskeleton redox proteome oxidation by cadmium

Epidemiological studies associate environmental cadmium (Cd) exposure with the risk of lung diseases. Although mechanisms are not fully elucidated, several studies demonstrate Cd effects on actin and actin-associated proteins. In a recent study of Cd at concentrations similar to environmental exposures, we found that redox-dependent inflammatory signaling by NF-κB was sensitive to the actin-disrupting agent, cytochalasin D. The goal of the present study was to use mass spectrometry-based redox proteomics to investigate Cd effects on the actin cytoskeleton proteome and related functional pathways in lung cells at low environmental concentrations. The results showed that Cd under conditions that did not alter total protein thiols or glutathione redox state caused significant oxidation of peptidyl Cys of proteins regulating actin cytoskeleton. Immunofluorescence microscopy of lung fibroblasts and pulmonary artery endothelial cells showed that low-dose Cd exposure stimulated filamentous actin formation and nuclear localization of destrin, an actin-depolymerizing factor. Taken together, the results show that redox states of peptidyl Cys in proteins associated with actin cytoskeleton pathways are selectively oxidized in lung by Cd at levels thought to occur from environmental exposure.
The Pathogenesis of β2‐Microglobulin–Induced Bone Lesions in Dialysis‐Related Amyloidosis

Dialysis-related amyloidosis (DRA), also referred to as beta(2)-microglobulin amyloidosis (A beta(2)M), is an important cause of morbidity in patients with chronic renal failure and in those who are on dialysis. Although DRA deposits from affected joints have been characterized as a unique amyloid fibril protein, beta(2)M, less is known about the pathologic role of beta(2)M as a mediator of bone and joint disease. Potential mechanisms for beta(2)M pathologic interaction in bone include bone growth factors, cytokines, and advanced glycation end products (AGEs). It appears that DRA is the result of a complex interaction between bone resorption and surrounding tissue destruction culminating in beta(2)M deposition and amyloid formation. More work is required to elucidate the relationship between beta(2)M accumulation and progressive tissue destruction.
Stability of association of 1-O-octadecyl-2-O-methyl-sn-glycero-3-phosphocholine with liposomes is composition dependent.

The ether lipid, 1- O -octadecyl-2- O -methyl-sn-glycero-3-phosphocholine (ET-18-OCH 3 ), has anticancer activity, but it has serious side-effects, including hemolysis, which prevent its optimal use. We surmised if ET-18-OCH 3 could be stably associated with liposomes, less free ET-18-OCH 3 would be available for lytic interaction with red cells. Liposome composition variables investigated included acyl chain saturation, phospholipid head group and mole ratio of Chol and ET-18-OCH 3 . It was found that attenuation of hemolysis was strongly liposome composition dependent. Some ET-18-OCH 3 liposome compositions were minimally hemolytic. For example, whereas the HI 5 (drug concentration required to cause 5% human red cell lysis) was 5–6 μ M for free ET-18-OCH 3 , it was approximately 250 μ M for DOPC (dioleoylphosphatidylcholine):Chol (cholesterol):DOPE-GA (glutaric acid derivatized DOPE):ET-18-OCH 3 , (4:3:1:2) and 640 μ M for DOPE (dioleyolphosphatidylethanolamine):Chol:DOPE-GA:ET-18-OCH 3 (4:3:1:2) liposomes. Efflux of carboxyfluorescein (CF) from liposomes and Langmuir trough determinations of mean molecular area of lipids in monolayers (MMAM) were used as indicators of membrane packing and stability. Incorporation of ET-18-OCH 3 in liposomes reduced the MMAM. Reduction in CF permeation was correlated with reduction in hemolysis. The most stable liposomes included components, such as cholesterol, DOPC and DOPE, which have complementary shapes to ET-18-OCH 3 .
Analysis of the elements of attention: A neuropsychological approach

A model for conceptualizing the components or elements of attention is presented. The model substitutes for the diffuse and global concept of “attention” a group of four processes and links them to a putative system of cerebral structures. Data in support of the model are presented; they are derived from neuropsychological test scores obtained from two samples, the first consisting of 203 adult neuropsychiatric patients and normal control subjects, and the second, an epidemiologically-based sample of 435 elementary school children. Principal components analyses of test scores from these two populations yielded similar results: a set of independent elements of attention that are assayed by different tests. This work presents a heuristic for clinical research in which the measurement of attention is essential.
The realities of risk, the nature of hope, and the role of science: A response to Cook and VandeCreek.

A response is offered to the critiques of both Cook and VandeCreek. Among the points emphasized are the simple realities of risk with suicidal patients, existing empirical research with informed consent in both clinical psychology and other health care areas, as well as the persistence of common myths in clinical practice with suicidal patients. Although empirical science provides a firm foundation to much of what is proposed, it is critical for practitioners to recognize and respond to the ethical demands for openness and transparency with high-risk clients in an effort to achieve shared responsibility in care. (PsycINFO Database Record (c) 2010 APA, all rights reserved). Language: en
Scopolamine and food-reinforced behavior in the rat

Male hooded rats were food-deprived and trained to barpress on a fixed ratio schedule in which every 25th bar press was reinforced (FR25) with liquid food. Three 5-min nonreinforced (SΔ) periods were imposed at the beginning, middle, and end of the session. Under the anticholinergic drug, scopolamine, the rate of barpressing did not differ significantly from control, but there was a significant delay in the onset of barpressing. Scopolamine-treated animals did not receive reinforcement until well into the FR25 period. The peripheral control drug, methyl scopolamine, did not cause a delay in the onset of barpressing. In addition, scopolamine, but not methyl scopolamine, caused a change in the topography of FR performance; the pauses typical of FR performance were frequently omitted or delayed. Finally, scopolamine, but not methyl scopolamine, caused a significant increase in the rate of barpressing during the second and third SΔ periods.
A single-pour horizontal gel electrophoresis apparatus

Abstract An apparatus is presented which allows rapid gel casting and employs non-platinum electrodes.
Social context influences the vocalizations of a home-raised African Grey parrot (Psittacus erithacus erithacus).

Home-raised African Grey parrots (Psittacus erithacus erithacus) exhibit strong social bonding with their human companions. We examined how 1 parrot’s vocal production (speech and nonword sounds) changed with social context with respect to descriptive measures of the vocalizations and their thematic content. We videotaped the parrot in 4 social conditions: subject home alone, subject and owner in the same room, owner in a separate room within hearing range, and owner and experimenter conversing in the same room as the parrot but ignoring her. Linguistic analysis revealed the parrot’s repertoire consisted of 278 “units” ranging in length from 1 to 8 words or sounds. Rate of vocalization and vocabulary richness (i.e., the number of different units used) differed significantly, and many vocalizations were context-specific. For example, when her owner was in the room and willing to reciprocate communication, the parrot was more likely to use units that, in English, would be considered solicitations for vocal interaction (e.g., “Cosmo wanna talk”). When she and her owner were in separate rooms, the subject was significantly more likely to use units that referenced her spatial location and that of her owner (e.g., “Where are you”), suggesting she uses specific units as an adaptation of the wild parrot contact call. These results challenge the notion that parrots only imitate speech and raise interesting questions regarding the role of social interaction in learning and communicative competence in an avian species.
Carbon−Hydrogen Bond Activation in Hydridotris(pyrazolyl)borate Complexes of Iridium

Methylene chloride solutions of the tris(1-pyrazolyl)borate (Tp) complexes TpIr(PPh3)(C2H4) or TpIr(C2H4)2 react with excess PPh3 via activation of a pyrazole C−H bond to form equilibrium mixtures ...
SOCIODEMOGRAPHIC RISK FACTORS TO DISEASE CONTROL IN CHILDREN WITH DIABETES.557

This study examined the independent and interactive effects of Ethnicity and SES on disease control in children and adolescents with diabetes. Other variables of interest included family structure and IQ of the child, since both of these variables have been associated with poorer metabolic control. Subjects were matched for and stratified by Ethnicity and SES. Three dependent variables were chosen to evaluate the disease control of the study participants, including HbA1 values averaged over the 2.5 years prior to study participation, number of hospitalizations, and number of hypoglycemic blackouts. Family Structure, IQ, and SES, but not Ethnicity, were the primary risk factors to disease control. Children from low-income families were in poorer metabolic control and experienced more episodes of hypoglycemic blackouts than did children from middle income families. In addition, children with IQ scores within or below the low average range of abilities were in poorer metabolic control than children with average or above IQ scores. The effects of family structure interacted with SES and IQ. Children from middle-class, two-parent families were in better metabolic control than all other groups and children with below average intellectual abilities from single-parent families were in poorer metabolic control than all other groups. These results indicate that it is not ethnicity, but other factors often confounded with ethnic status, that may pose a risk to disease status of children and adolescents with diabetes.
Virus-Tumor Synergism

More than 30 mouse tumors are associated with virus-like agents that may readily be detected by enzymic techniques. Radiation and chemically induced tumors do not ordinarily give evidence of such activity. The present report is of experiments in which a synergistic effect has been observed to occur when animals were inoculated with both the filtrable agent and a virus-free tumor. Synergism was shown by accelerated growth of the tumor and by elevation of a glycolytic enzyme (lactic dehydrogenase) in the host plasma
The emerging role of number theory in exactly solvable models in lattice statistical mechanics

Abstract We review the Baxter model, the hard hexagon model and their multistate generalizations from a point of view that stresses the connection with modular functions and additive number theory. It is shown, for example, that various physical quantities in the hard hexagon model are all expressible in terms of modular functions. The use of Rogers-Ramanujan type identities in solvable models is also reviewed.
Molecular and cytologic studies of Ehlers-Danlos syndrome type VIII

We present a family with findings of Ehlers-Danlos syndrome type VIII and a presenile appearance due to decreased subcutaneous tissue with drawn skin, defective wound healing, contractures, and thin hair. To investigate this syndrome, we studied collagen production and the growth properties of cultured fibroblasts taken from affected relatives. We could not find evidence of a collagen defect or premature senescence of cultured fibroblasts, although the fibroblasts may have a decreased growth rate. We conclude that this family has findings of EDS VIII and premature aging and propose that this overlapping phenotype is due to a single pathogenetic mechanism. Our studies of collagen production and fibroblast replication did not discern this mechanism.
Exploration of Environmental and Genetic Risk Factors for Alzheimer's Disease: The Value of Cross-Cultural Studies

Advances in molecular genetics have revolutionized epidemiological research. It is now possible to combine the techniques of population genetics with research on risk factors to construct genetic-environmental interactive models that explain geographic-ethnic variations in disease rates. Cross-cultural studies involving populations from developing and developed countries offer a unique opportunity for constructing these models by providing a wide diversity of environmental exposures. Results from a comparative Indianapolis-Ibadan study suggest that Alzheimer's disease incidence rates are lower in Yoruba than in African Americans and that these lower rates may be due to a combination of genetic and environmental, primarily dietary, influences.
Computerized Design and Generation of Worm Gear Drives with Stable Bearing Contact and Low Transmission Errors

The authors propose a new approach for design and generation of low-noise, stable bearing contact gear drive with cylindrical worm. The approach is based on application of an oversized hob and varied plunging of worm generating tool. It is discovered that without plunging positive transmission errors occur (that are unacceptable for favorable conditions of force transmission). A predesigned parabolic function is provided that is able to absorb transmission errors caused by misalignment and reduce the level of vibrations, especially in the case of application of multi-thread worms. The developed approach is tested by computerized simulation of meshing and contact by the developed computer program. The investigation is accomplished for a worm-gear drive with the Klingelnberg type of the worm that is ground by a circular cone, but the proposed approach may be applied for other types of worm gear drives with cylindrical worms.
Molecular Cloning and Characterization of a Novel Retinoblastoma-Binding Protein ☆

We describe the isolation and characterization of a novel cDNA encoding a polypeptide that interacts in a yeast two-hybrid system as well as in mammalian cells with the retinoblastoma (RB) protein. This new protein, which we call Rim, consists of 897 amino acids, has two leucine zipper motifs, and has a LECEE sequence previously identified as an RB-binding domain. Rim also has an E1A/CtBP-binding motif and four putative nuclear localization signals. Rim mRNA is expressed ubiquitously at low levels in all human adult tissues tested and at much higher levels in several tumor cell lines. The Rim gene (HGMW-approved symbol RBBP8) is localized on human chromosome 18q11.2.
Professional service firm advantage: Establish work flow relationships

Intensifying competition, perceptions of low quality, rapid technological innovations all present business climates the piofessional service team must endeavor to overcome. One possible wav to do this is to have the orofessional service fm implement a sadsfaction chain approach. h e satisfaction chain is a method of reviewing, illustrating, and then managing critical links that lead ultimately to the service exchange or encounter. Despite the heavy emphasis on generating knowledge about the actual encounter itself, the aulhor maintains that another dimension is also important. Spe- cifically, care must.be taken to develop and nurture supplier and employee relationships that, taken together, build the foundation for successful service delivery.
Otolith fibers and terminals in chick vestibular nuclei.

The distribution of gravity-sensing, otolith afferent fibers and terminals was studied in the vestibular nuclei of 4–5-day hatchling chicks by using single and double labeling of fibers and terminals with biocytin conjugated to Alexa Fluor and confocal imaging. The vestibular nuclei are represented in a series of five transverse sections of the brainstem immunolabeled with MAP2. Saccular fibers entered the medulla posterior to and at the level of the posterior tangential vestibular nucleus and coursed through ventral parts, producing ascending and descending branches. Small saccular terminals contacted a few dendrites in the tangential nucleus. In contrast, small saccular terminals contacted many dendrites and a few neuron cell bodies in the ventrolateral vestibular nucleus, vestibulocerebellar nucleus, and descending vestibular nuclei. Utricular fibers coursed through ventral parts of the central tangential nucleus before bifurcating into ascending and descending branches. In the tangential nucleus, utricular fibers formed a few large axosomatic terminals (spoon terminals) and a few small terminals on dendrites. In addition, small utricular terminals contacted numerous dendrites and a few neuron cell bodies in the ventrolateral, vestibulocerebellar, and descending vestibular nuclei. Thus, there was negligible overlap in the distribution of the otolith nerves, although each otolith afferent shared common regions with the canal afferents, previously shown, suggesting that some second-order vestibular neurons process convergent inputs from otolith and canal afferents. Taken together with previous results, the present findings identify discrete regions of the chick vestibular nuclei where second-order vestibular neurons likely process directly convergent otolith and canal inputs. J. Comp. Neurol. 502:19–37, 2007. © 2007 Wiley-Liss, Inc.
Dehomogenization: reconstruction of moments of the spectral measure of the composite

This paper deals with the inverse homogenization or dehomogenization problem of recovering geometric information about the structure of a two-component composite medium from the effective complex permittivity of the composite. The approach is based on the reconstruction of moments of the spectral measure in the Stieltjes analytic representation of the effective property. The moments of the spectral measure are linked to n-point correlation functions of the structure of the composite and thus contain information about the microgeometry. We show that the moments can be uniquely recovered from the measurements of the effective property in a range of frequencies. Two methods of numerical reconstruction of the moments are developed and analyzed. One method, which is referred to as a direct method of moment reconstruction, is based on the solution of the Vandermonde system arising in series expansion of the Stieltjes integral. The second, indirect, method reformulates the problem and reduces it to the problem of reconstruction of the spectral function. This last problem is ill-posed and requires regularization. We show that even though the reconstructed spectral function can be quite sensitive to the choice of the regularization scheme, the moments of the spectral functions can be stably reconstructed. The applicability of these two methods in terms of the choice of data points is also discussed in this paper.
NAFLD may be a common underlying liver disease in patients with hepatocellular carcinoma in the United States

The incidence of hepatocellular carcinoma (HCC) in the United States is increasing, but the clinical characteristics of American patients with HCC have not been well described. The aims of this study were to determine the etiology of liver disease and short-term outcome among HCC patients presenting to a single center in the United States. One hundred five consecutive patients with HCC were studied; mean age was 59 years, 67% were men, and 76% were non-Hispanic white. The most common etiology of liver disease was hepatitis C (51%) and cryptogenic cirrhosis (29%). Half of the patients with cryptogenic cirrhosis had histologic or clinical features associated with nonalcoholic fatty liver disease (NAFLD). Fifty-three (50%) patients had HCC detected during surveillance (group I), whereas the remaining patients had symptomatic tumors (group II). Group I patients had smaller tumors (P =.01), were more likely to be eligible for surgical treatment (P =.005), and had a better median survival compared with patients in group II (P =.001). Patients with cryptogenic cirrhosis were less likely to have undergone HCC surveillance and had larger tumors at diagnosis. In conclusion, hepatitis C and cryptogenic liver disease are the most common etiologies of diseases in our patients with HCC. NAFLD accounted for at least 13% of the cases. Patients who underwent surveillance had smaller tumors and were more likely to be candidates for surgical or local ablative therapies. Because of the increasing incidence of NAFLD, further studies are needed to determine the risk of HCC in patients with NAFLD.
Systematics of North American and Greater Antillean Species of Embidopsocus (Psocoptera: Liposcelidae)

This paper treats all species of Embidopsocus known to the author from North America and the Greater Antilles. Three species, previously placed under the name E. laticeps Mockford, are recognized and are described as new. E. laticeps (s.s.) is redescribed to allow detailed comparison with the new species. The original description of E. laticeps refers only to the species in the now-restricted sense; Illinois and Cuban records refer to E. bousemani , n. sp., and E. cubanus , n. sp., respectively. E. femoralis (Badonnel) and E. thorntoni Badonnel are recorded from the region for the first time. The male of E. femoralis , previously unknown, is described. E. luteus Hagen, the generotype, is recorded for the first time from continental North America. A key to the species of the region is included.
Predictive isotope model connects microbes in culture and nature.

In PNAS, Wing and Halevy (1) present a new model that quantitatively describes the magnitude of sulfur isotope fractionation produced by dissimilatory microbial sulfate reduction (MSR). MSR is a major player in the global biogeochemical cycles and is responsible for the respiration of up to 30% of organic matter in marine sediments (2). This metabolism produces large isotope effects, in which the product, sulfide, is depleted in the heavy isotopes (33S, 34S, and 36S) relative to the most abundant isotope 32S (3), enriching modern seawater sulfate in 34S by about 21‰ (parts per thousand) compared with mantle sulfur. Sedimentary sulfur minerals preserve a record of this effect and are used to track changes in the sulfur isotope composition of seawater and the biogeochemical sulfur, carbon, and oxygen cycles through geologic time (4). Such reconstructions require an understanding of factors that control the magnitude of sulfur isotope effects and dictate the fractionation of sulfur isotopes by sulfate reducers under a range of growth conditions.
Cloud Resolving Modeling

One of the most promising methods to test the representation of cloud processes used in climate models is to use observations together with cloud-resolving models (CRMs). CRMs use more sophisticated and realistic representations of cloud microphysical processes, and they can reasonably well resolve the time evolution, structure, and life cycles of clouds and cloud systems (with sizes ranging from about 2-200 km). CRMs also allow for explicit interaction between clouds, outgoing longwave (cooling) and incoming solar (heating) radiation, and ocean and land surface processes. Observations are required to initialize CRMs and to validate their results. This paper provides a brief discussion and review of the main characteristics of CRMs as well as some of their major applications. These include the use of CRMs to improve our understanding of: (1) convective organization, (2) cloud temperature and water vapor budgets, and convective momentum transport, (3) diurnal variation of precipitation processes, (4) radiative-convective quasi-equilibrium states, (5) cloud-chemistry interaction, (6) aerosol-precipitation interaction, and (7) improving moist processes in large-scale models. In addition, current and future developments and applications of CRMs will be presented.
Statistical correction and downscaling of chemical transport model ozone forecasts over Atlanta

The Regional Air Quality forecAST (RAQAST) model is a regional chemical transport modeling system for ozone and its precursors over the United States. Since the grid size is 70 by 70 km, forecasts cannot be made for a specific surface site. We use EPA monitoring stations from the Atlanta area to downscale and improve local forecasts using RAQAST outputs. We use the Model Diagnostic and Correction (MDC) approach. First, we regress the observations on the model outputs with an autoregressive noise component. Second, we regress the residuals of this first regression on variables associated with wind speed, precipitation amounts and the diurnal cycle. Deficiencies of 3-D model results are identified and corrected. Evaluation using measurements for a different period confirms that the statistically adjusted outputs reduce forecast errors by up to 25%.
Experiences in the treatment of certain urinary tract malignancies with supervoltage Roentgen therapy

Abstract 1. 1. Preoperative irradiation as an adjunct in the treatment of renal tumors is a definite step forward. 2. 2. Where possible, irradiation with the ultra short wave potential is definitely superior to medium voltage therapy. 3. 3. Postoperative irradiation alone does not enhance the prognosis. 4. 4. Adequate preoperative irradiation with limited postoperative irradiation argues for the best prognosis. 5. 5. Irradiation and operation in the presence of established metastasis is futile. 6. 6. Irradiation without surgery is futile. 7. 7. Transperitoneal extirpation of the irradiated tumor greatly facilitates the ease of operation. 8. 8. Under the above regime the curability of renal tumors is not asserted, but it is felt that the prognosis is more hopeful.
Ultrafast Measurements on Direct Photoinduced Electron Transfer in a Mixed Valence Complex

Abstract : In this paper, we report the first direct kinetic measurement of a MMCT optically induced et reaction, and compare the experimental results to theoretical predictions using experimentally estimated parameters. Our work is oriented, in part, toward evaluating contemporary theoretical models that explicitly consider the dramatic effect of solvation dynamics on et rates. In the last decade it has been established that et rates can be directly proportional to the time scale for solvent motion for simple systems in certain limits. The transient pump-probe apparatus has been described elsewhere. The laser source is an intermediate repetition rate (8.2kHz) amplified dye laser with 70fs pulse duration. The energy of the pump and probe pulses were typically 400 and 20 nj, respectively.
Appropriate experiences for the gifted science student

Giftedness in science can be enhanced by providing a variety of enrichment and acceleration activities for students.
Super strong effect of surface impurities on the resistance and Hall effect of quench condensed Cs films

Thin films of Cs, quench condensed onto a He cold quartz plate, possess electronic mean free paths which considerably exceed the film thicknesses. When theses films are covered in situ with sub monolayers of Au, Ag, In, Rh and Pb in the range between 0.01 and 1 monolayers the film resistance and the Hall constant increase dramatically. This corresponds to a scattering cross section of the surface impurities which is larger than 1 in units of Various models are explored to explain these unusual behavior. None yields a satisfactory explanation for this extremely strong effect of surface impurities on the resistance and the Hall effect.
Ectopic dendritic growth in mature pyramidal neurones in human ganglioside storage disease.

PYRAMIDAL CELLS are highly differentiated cortical neurones whose morphophysiological properties derive largely from dendritic systems that provide most of the postsynaptic sites for excitatory and inhibitory synaptic inputs1. As pyramidal cell function is closely linked to dendritic geometry2,3 factors influencing dendritic growth determine to a large extent connectivity patterns in cortical neuronal organisations4–6. Although various experimental manipulations hinder attainment of normal dendritic geometry7 no factors or conditions are known to induce dendritic growth and differentiation in intact, mature cortical neurones. I present here morphological evidence that in human ganglioside storage disease pyramidal neurones, having completed an initial period of normal dendritic growth, undergo a second phase of dendritic growth and differentiation at aberrant sites. I have referred to this in another context as ectopic dendrogenesis8.
Abundance of fungi and bacteria in a nutrient-impacted Florida wetland

Microorganisms have been proposed as early indicators of wetland change; however, there is often too little information to reliably use microbial parameters for this purpose. The objective of this study was to document how nutrient loading, plant community, and season affected arbuscular mycorrhizal (AM) fungi (expressed as percent colonized root length), other fungi (estimated by ergosterol concentration), and bacteria (quantified by direct counts) in soil and detritus, and thereby to broadly evaluate the potential of native microorganisms to serve as indicators of wetland integrity. Dominant wetland plant communities (Panicum, Cladium, Typha, Salix, mixed herbaceous, and deep-water slough) were sampled seasonally from nutrient-impacted and reference areas of a central Florida wetland with historic nutrient loading (only Cladium occurred in both impacted and reference areas). Nutrient impact increased soil and detrital ergosterol and bacterial counts in some plant communities and seasons (e.g., Cladium sampled in the fall); however, the nutrient effect was confounded by interactions with the plant community and season. Nutrient impact reduced AM root colonization in samples from impacted compared to reference Cladium communities during summer and fall; however, there were again significant interactions with season and other plant communities. We conclude that before soil fungi and bacteria can be used as indicators of wetland integrity background values for each plant community and season need to be well documented.
Microtubules in differentiating sieve elements of Gossypium hirsutum.

Changes in distribution, orientation, and abundance of microtubules (MT) in relation to sieve element differentiation in root protophloem and stem and midvein metaphloem of Gossypium hirsutum were studied at the ultrastructural level. Depending on their stage of differentiation the sieve elements were divided into four previously characterized groups: Stage 1—the least differentiated cells; Stage 2—the differentiating cells; Stage 3—the nearly mature cells containing nuclear remnants; and Stage 4—the mature cells. In dividing cells of Stage 1, MT are observed only as part of the phragmoplast. After the division is completed MT, oriented at right angles to the long axis of the cell, begin to appear along the lateral walls. The number of MT increases, reaching a plateau and remaining relatively constant in successively older Stage 1 sieve elements. The increase in cell wall thickness is most obvious at the plateau phase, when the maximum numbers of MT are observed. The protoplast of a sieve element in Stage 1 contains a normal nucleus, dispersed plastids and mitochondria, and scattered ER cisternae. At Stage 1, MT in adjacent parenchyma cells are not abundant. During Stage 2 of sieve element differentiation, when nuclear chromatin aggregates, plastids and mitochondria assume a peripheral position in the cell, and ER cisternae accumulate into convoluted masses, the number of MT along the lateral walls decreases. In adjacent parenchyma cells the MT are abundant at this stage. MT have also been observed adjacent to sieve plates of cells in Stages 1 and 2. These MT appeared in transverse and longitudinal views in the same sections.
Regulation of APP synthesis and secretion by neuroimmunophilin ligands and cyclooxygenase inhibitors.

We and others previously showed that both the synthesis of the amyloid precursor protein (APP) and its processing (i.e., to amyloidogenic A beta peptides; soluble nonamyloidogenic APPs; and other APP fragments) are regulated by neurotransmitters. Transmitters that elevate cellular cAMP levels (like norepinephrine and prostaglandins, which act on beta-adrenergic receptors and prostaglandin E2 receptors respectively) enhance APP synthesis and the formation of amyloidogenic APP holoprotein. Transmitters that stimulate phosphatidylinositol hydrolysis (by activating muscarinic m1 or m3 receptors, serotoninergic 5HT2a or 5HT2c receptors, or metabotropic glutamate receptors of subtypes 1 or 5) increase the conversion of APP to soluble APPs, and decrease the formation of A beta. These findings suggest that drugs that regulate the activity of neurotransmitter receptors might be useful in preventing the excessive formation of A beta or other amyloid precursors in Alzheimer's disease. We now show that neuroimmunophilin ligands (like cyclosporin A or FK-506) and nonsteroidal antiinflammatory agents (NSAIDs), including cyclooxygenase (COX)-2 inhibitors, can also prevent APP overexpression and the overproduction of amyloidogenic peptides. We observe that the enhancement of APP overexpression by prostaglandin E2 is inhibited by neuroimmunophilin ligands like cyclosporin A or FK-506 (tacrolimus). We also find that the NSAIDs, which reduce prostaglandin synthesis by inhibiting COX-1 and -2 enzymes, might also be expected to lower APP levels. Our present data confirm that these drugs, as well as drugs that selectively inhibit COX-2, reduce the levels of amyloidogenic APP holoprotein in cultured neurons or in cultured astrocytes. We previously showed that elevations in cAMP, perhaps generated in response to prostaglandins, can suppress APPs secretion. The NSAIDs and COX inhibitors also increased levels of soluble APPs in the media of cultured astrocytes and neurons, perhaps acting by inhibition of prostaglandin production. Since APP holoprotein can be amyloidogenic, while APPs may be neurotrophic, our findings suggest that some neuroimmunophilin ligands, NSAIDs and COX-2 inhibitors might suppress amyloid formation and enhance neuronal regeneration in Alzheimer's disease.
The Role of School-Related Bonding Factors and Gender: Correlates of Gang Membership Among Adolescents

In the past several decades both the education and criminology literatures have examined the influence of school factors on the attitudes and behaviors of adolescents. This literature shows that school-related factors, especially those related to social bonding, are relevant to explaining delinquent behavior. This research examines the efficacy of school-related bonding factors in explaining gang membership. In addition, it examines whether these bonding factors differentially explain male and female gang membership. The results show that delinquent involvement is the strongest predictor of gang membership among middle school children. Although several bonding variables are related to gang membership, their influence is very weak. In addition, we do not find support for the hypothesis that these variables differentially explain male and female gang membership. Implications and suggestions for future research are discussed.
Buckling mosaic of a circular plate on a partial elastic foundation

Buckling of plates resting on an elastic foundation is important in numerous practical applications such as concrete pavements and foundations on soil. The buckling of circular plates has been reported by several authors (Yu 1957, Galletly 1959, Kline and Hancock 1965, Wolkowisky 1969, Gupta et al. 1991, Gupta and Ansari 1998, Wang 2005, Gupta et al. 2006). All of the above sources considered a circular plate resting on a full elastic foundation. The present Note studies the buckling of a circular plate on a partial concentric elastic foundation which is important for centrally supported or stiffened plates. We shall investigate whether there are any other asymmetric buckling modes aside from those reported by Wang (2005). Our solutions will also be exact, such that no numerical errors are incurred. Exact buckling criteria also serve as standards for checking results from approximate or numerical methods (Wang et al. 2005).
Monetary Policy Transmission in the GCC Countries

The GCC countries maintain a policy of open capital accounts and a pegged (or nearly-pegged) exchange rate, thereby reducing their freedom to run an independent monetary policy. This paper shows, however, that the pass-through of policy rates to retail rates is on the low side, reflecting the shallowness of money markets and the manner in which GCC central banks operate. In addition to policy rates, the GCC monetary authorities use reserve requirements, loan-to-deposit ratios, and other macroprudential tools to affect liquidity and credit. Nonetheless, a panel vector auto regression model suggests that U.S. monetary policy has a strong and statistically significant impact on broad money, non-oil activity, and inflation in the GCC region. Unanticipated shocks to broad money also affect prices but do not stimulate growth. Continued efforts to develop the domestic financial markets will increase interest rate pass-through and strengthen monetary policy transmission.
The S‐Distribution: Approximation of Discrete Distributions

The S-distribution is defined by the ordinary differential equation dF/dX = α(Fg — FhFo = F(Xo), where F is the cumulative distribution of the random variable X, and α, g, h, and Fo are parameters. The S-distribution was recently described in this journal as a tool for the approximation and classification of univariate, unimodal continuous probability distributions. This article shows that the S-distribution rather accurately models the commonly used univariate discrete distributions.
Mood stabilizers in Alzheimer's disease: symptomatic and neuroprotective rationales.

Abstract Objective : This paper provides a case study of ‘reverse translational research’, in which empirical clinical trials focused on relieving psychopathological symptoms of Alzheimer’s disease (AD) ultimately led to mechanism-based trials addressing aspects of the underlying pathophysiology of Alzheimer’s disease. AD is multi-dimensional in nature, characterized not only by cognitive and functional decline but by neuropsychiatric symptoms that develop commonly and are associated with considerable morbidity. There have been a large number of empirical trials of various pharmacological agents to reduce these symptoms, such as agitation. Although antipsychotics are used most frequently for agitation, the usual effect size is modest, and there is a range of tolerability and/or safety issues, leading to the hope that alternatives can be found. Furthermore, most clinical trials addressing psychopathology have not been mechanism-based and none have attempted an alternative approach, namely, to delay or prevent the emergence of psychopathology. Findings : The evidence of clinical trials is reviewed regarding the safety, tolerability, and apparent efficacy of the mood stabilizers carbamazepine and valproate for agitation associated with AD. Possible mechanisms of action of valproate are reviewed, leading to the surprising conclusion that neuroprotective properties may account for some of its clinical effects. These mechanisms (including activation of wnt-dependent signaling and upregulation of bcl-2, among others) may be particularly relevant for long-term treatment of AD. Conclusions : These clinical and mechanistic findings were combined in the development of a novel clinical trial examining whether chronic valproate therapy can attenuate the clinical progression of AD, which will be implemented by the Alzheimer’s Disease Cooperative Study. The design addresses valproate’s potential to delay or prevent the onset of agitation in patients lacking agitation to begin with, as well as to slow progressive decline in cognition and daily functioning.
Baclofen in the Treatment of Polymyoclonus and Ataxia in a Patient With Homocystinuria

A patient with homocystinuria due to cystathionine β-synthase deficiency developed severe progressive polymyoclonus and ataxia. To our knowledge, this is the first time polymyoclonus and ataxia have been reported in association with homocystinuria. Although cerebrovascular thrombosis is usually thought to be responsible for neurologic dysfunction in homocystinuric patients, no infarctions were demonstrated on magnetic resonance imaging scans in our case. We have previously reported that baclofen dramatically improved the polymyoclonus and ataxia in a patient with Unverricht-Lundborg disease. Baclofen given to our patient reversed the polymyoclonus and the ataxia as well. This suggests that patients with polymyoclonus and ataxia, no matter what the etiology, may benefit from the use of baclofen. (J Child Neurol 1995; 10:294-296).
The United States, Canada and the Indians: 1865–1876

Abstract Between 1865 and 1876 Canada and the United States faced similar situations in their relationship with Indians. Yet the two countries pursued different strategies. Issues included the definition of an Indian, the place of mixed blood people, treaties, land ownership, assimilation, missionaries, maintenance of peace, and the scope of law.
Neurocirculatory Abnormalities in Parkinson Disease With Orthostatic Hypotension: Independence From Levodopa Treatment

Patients with Parkinson disease often have orthostatic hypotension. Neurocirculatory abnormalities underlying orthostatic hypotension might reflect levodopa treatment. Sixty-six Parkinson disease patients (36 with orthostatic hypotension, 15 off and 21 on levodopa; 30 without orthostatic hypotension) had tests of reflexive cardiovagal gain (decrease in interbeat interval per unit decrease in systolic pressure during the Valsalva maneuver; orthostatic increase in heart rate per unit decrease in pressure); reflexive sympathoneural function (decrease in pressure during the Valsalva maneuver; orthostatic increment in plasma norepinephrine); and cardiac and extracardiac noradrenergic innervation (septal myocardial 6-[18F]fluorodopamine-derived radioactivity; supine plasma norepinephrine). Severity of orthostatic hypotension did not differ between the levodopa-untreated and levodopa-treated groups with Parkinson disease and orthostatic hypotension (-52+/-6 [SEM] versus -49+/-5 mm Hg systolic). The 2 groups had similarly low reflexive cardiovagal gain (0.84+/-0.23 versus 1.33+/-0.35 ms/mm Hg during Valsalva; 0.43+/-0.09 versus 0.27+/-0.06 bpm/mm Hg during orthostasis); and had similarly attenuated reflexive sympathoneural responses (97+/-29 versus 71+/-23 pg/mL during orthostasis; -82+/-10 versus -73+/-8 mm Hg during Valsalva). In patients off levodopa, plasma norepinephrine was lower in those with (193+/-19 pg/mL) than without (348+/-46 pg/mL) orthostatic hypotension. Low values for reflexive cardiovagal gain, sympathoneural responses, and noradrenergic innervation were strongly related to orthostatic hypotension. Parkinson disease with orthostatic hypotension features reflexive cardiovagal and sympathoneural failure and cardiac and partial extracardiac sympathetic denervation, independent of levodopa treatment.