cssi/SciSciGPT-SciSciNet huggingface dataset:
Age-Related Changes in Type 1 and Type 2 Cytokine Production in Humans

Although aging is accompanied by several changes in immune function, altered T cell function represents the most consistent and dramatic change. Since cytokines modulate the immune response, it has been postulated that these age-associated changes in T cell function may be due to alterations in cytokine production. Data from murine studies generally support an age-related shift from a Th1-like (IL-2, IFN-γ) to a Th2-like (IL-4, IL-6,IL-10) cytokine response; however, whether or not such an age-related shift to a Type 2 cytokine response occurs in humans is not certain. This review of over 60 studies in humans, in which Type 1 and Type 2 cytokines were evaluated either alone or together, suggests that age-associated changes in cytokine production are inconsistent. Further, these age-associated changes in cytokine production do not always induce a shift to a Type 2 cytokine response. Importantly, these studies highlight that the stimulus used to induce cytokines influences both the level and pattern of immune response. Additional comprehensive evaluations in human studies are both critical and necessary to clearly identify the impact of altered cytokine production on age-related changes in immune function.
Developing an electrical RFP: A case history

In early 2000, an international food warehousing company (company) received an unsolicited proposal from an alternative energy supplier in one of the midwestern states in which they were located. Prior to receiving this proposal, the company had developed a supply contract in the California market as a result of another unsolicited proposal. The receipt of this second proposal began the evaluation of the potential opportunities that electrical deregulation presented for their business locations throughout the United States. Initially, the search concentrated on finding one provider to handle their energy requirements throughout the United States. Continued work on their program and contact with numerous potential vendors resulted in the movement from a national program to a regional program. This article discusses how the company developed a procurement strategy for one of their regions, developed an electrical service RFP, evaluated the market and savings potential, evaluated the RFP responses, and negotiated a contract for service. The work completed during the midwest regional procurement project became a template for their other regions to approach procurement programs and benefit from deregulation opportunities. In addition, several of the facilities entering into a multi-year procurement contract had projected total savings of almost $500,000, or approximately 14 percent savings compared to their previous electrical rate. The first part of the document discusses the preliminary evaluations that the company completed to allow them to determine that deregulation could help them improve their bottom line. The second part discusses some of the evaluations that were made to put current and potential bid prices into perspective. The third part of the document discusses the process that the company used to develop the RPF, contact potential vendors, develop a short-list, interview vendors, analyse the offers and market conditions, select a negotiating partner and finalize a contract.
COMPARISON OF THE GENOMIC ORGANIZATION AND PROMOTER FUNCTION FOR HUMAN INTERLEUKIN-8 RECEPTORS A AND B

Human neutrophils are highly responsive to the chemokine interleukin-8 (IL-8) owing to high levels of expression of two related receptors encoded by the single copy genes il8ra and il8rb located on chromosome 2q34-q35. To identify nuclear factors that regulate the expression of IL-8 receptors, we have first defined the organization of both genes and characterized their functional promoters. il8ra and il8rb span approximately 4 and 12 kilobase pairs of genomic DNA, respectively. In both cases, the open reading frame resides on a single exon. In contrast, the 5'-untranslated regions are more complex. For il8ra, it is formed from two exons, whereas for il8rb, seven distinct neutrophil mRNAs are formed by alternative splicing of 11 exons. One of the splice variants, designated IL8RB3, is the predominant form for il8rb. Two equally abundant mRNAs for il8ra, 2.0 and 2.4 kilobases in length, are expressed in neutrophils and arise from usage of two alternative polyadenylation signals. Primer extension analysis identified two major transcription start points for il8ra and 11 for il8rb. Regions extending 300 base pairs (bp) upstream from exon 1 of il8ra and 81 bp upstream from exon 3 of il8rb have limited sequence similarity but had strong constitutive promoter activity when cloned upstream from a chloramphenicol acetyltransferase-encoding reporter gene and transiently transfected into surrogate myeloid (HL-60, and U-937) and lymphoid (Jurkat) cell lines. Neither of these regions has sequences corresponding to classic promoter elements. In contrast, a region 643 base pairs upstream from exon 1 of il8rb had relatively low levels of constitutive promoter activity in all three cell environments, and a conserved TATA element is located 47 bp upstream of the 5'-end of exon 1. Thus, despite marked differences in the complexity of their genomic organization, il8ra and il8rb encode products that are similar in structure, function, and the major cell type of expression.
Engineering Complex Systems

Using the current instantiation of the Air and Space Operations Center (AOC), and the desired evolution of it, the AOC is shown to be best thought of as a complex system. Complex Systems are alive and constantly changing. They respond and interact with their environments – each causing impact on (and inspiring change in) the other. We make the case that a traditional systems engineering (TSE) approach does not scale to the AOC; consequently, we don’t believe TSE scales to the “enterprise.”
Hydrologic conditions drive denitrification and greenhouse gas emissions in stormwater detention basins

Abstract Stormwater detention basins are primarily designed to detain large volumes of storm runoff and trap suspended sediments and associated pollutants. Detaining and retaining nutrients are often not a design focus. The combination of variable moisture patterns in stormwater basins along with potential nutrient influxes may make these basins hotspots for nitrogen transformations such as denitrification, as well as potential sources of greenhouse gases nitrous oxide (N2O) and methane (CH4). Nitrous oxide and CH4 emissions were measured using static chambers in four stormwater detention basins – two fast-draining or ‘dry’ basins and two slow-draining or ‘wet’ basins. Denitrification potential of soils collected from these basins was also measured using the denitrification enzyme assay (DEA). While N2O emissions were low, CH4 emissions were higher in both wet basins, averaging 5667 μg C m−2 h−1 in the wettest basin. Denitrification potential was higher in the wet basins (2.27 mg N kg−1 h−1) compared to the dry basins (0.23 mg N kg−1 h−1). Overall, wet detention basins had higher greenhouse gas emissions but also had higher potential for nitrate removal via denitrification. Designing future stormwater control measures to maintain a subsurface saturated zone rather than fully saturated soils should be considered to promote denitrification while also reducing CH4 emissions at the surface.
Competitive Growth of Genetically Marked Malolactic-Deficient Lactobacillus plantarum in Cucumber Fermentations.

Procedures were developed for the differential enumeration of an added strain of Lactobacillus plantarum and indigenous lactic acid bacteria (LAB) during the fermentation of brined cucumbers. The added strain was an N,N-nitrosoguanidine-generated mutant that lacked the ability to produce CO2 from malic acid (MDC-). The MDC- phenotype is desirable because CO2 production from malic acid decarboxylation has been shown to contribute to bloater formation in fermented cucumbers. A basal medium containing malic acid and adjusted to pH 4.0 permitted growth of indigenous LAB (predominantly MDC+), but not growth of the added MDC- culture. Transformation of the MDC- culture by electroporation with cloning vector pGK12 conferred chloramphenicol resistance, which permitted selective enumeration of this culture. The reversion frequency of the MDC- mutation was determined by a fluctuation test to be less than 10-10. The level of retention of plasmid pGK12 was greater than 90% after 10 generations in cucumber juice medium at 32°C. With the procedures developed, we were able to establish the ratio of MDC- to MDC+ LAB that results in malic acid retention in fermentations of filter-sterilized cucumber juice and unsterilized whole cucumbers under specified conditions.
Catalytic Pyrolysis of Pine Over HZSM-5 with Different Binders

Three HZSM-5 catalysts with different binders (alumina, silica, and clay) were evaluated for upgrading of pine pyrolysis vapors. All catalysts were based on the same HZSM-5 with silica to alumina molar ratio of 30. Experiments in micro-scale analytical Py-GCMS/FID showed that fresh catalysts with silica and clay produced predominantly aromatic hydrocarbons at similar carbon yields. The catalyst with alumina gave lower vapor yields and produced both hydrocarbons and partially deoxygenated products, in particular furans. The catalyst with alumina also gave higher coke yields and exhibited faster deactivation than the catalysts with clay and silica binders. The low hydrocarbon yields and coke formation were attributed to the acidic sites provided by alumina and blocking of the zeolite sites. The catalysts with silica and clay as binders were further tested in a 2-inch fluidized bed system for ex situ catalytic pyrolysis of pine. Similar oils were produced over both catalysts with carbon yields of approximately 23 % and oxygen contents of 20–21 %.
Heterogeneous accumulation of fluorescent bile acids in primary rat hepatocytes does not correlate with their homogenous expression of ntcp

Sodium taurocholate-cotransporting polypeptide (ntcp) is considered to be a major determinant of bile acid uptake into hepatocytes. However, the regulation of ntcp and the degree that it participates in the accumulation of specific substrates are not well understood. We utilized fluorescent bile acid derivatives and direct quantitation of fluorescent microscopy images to examine the regulation of ntcp and its role in the cell-to-cell variability of fluorescent bile acid accumulation. Primary-cultured rat hepatocytes rapidly accumulated the fluorescent bile acids, chenodeoxycholylglycylamidofluorescein (CDCGamF), 7-β- nitrobenzoxadiazole 3-α hydroxy 5-β cholan-24-oic acid (NBD-CA), and cholyl-glycylamido-fluorescein (CGamF). However, in stably transfected HeLa cells, ntcp preferred CDCGamF, whereas the organic anion transporter, organic anion transporting polypeptide 1 (oatp1a1), preferred NBD-CA, and neither ntcp nor oatp1a1 showed strong accumulation of CGamF by these methods. Ntcp-mediated transport of CDCGamF was inhibited by taurocholate, cyclosporin, actin depolymerization, and an inhibitor of atypical PKC-ζ. The latter two agents altered the cellular distribution of ntcp as visualized in ntcp-green fluorescent protein-transfected cells. Although fluorescent bile acid accumulation was reproducible by the imaging assays, individual cells showed variable accumulation that was not attributable to changes in membrane permeability or cell viability. In HeLa cells, this was accounted for by variable levels of ntcp, whereas, in hepatocytes, ntcp expression was uniform, and low accumulation was seen in a large portion of cells despite the presence of ntcp. These studies indicate that single-cell imaging can provide insight into previously unrecognized details of anion transport in the complex environment of polarized hepatocytes.
Review of: “Reliability for technology, engineering, and management”Paul Kales Prentice Hall, 1998, 392 pp., ISBN 0-13-485822-0

(2000). Review of: “Reliability for technology, engineering, and management”Paul Kales Prentice Hall, 1998, 392 pp., ISBN 0-13-485822-0. IIE Transactions: Vol. 32, No. 6, pp. 567-568.
Necking and Failure of Constrained Contractile 3D Microtissues Induced by Cell Derived Tension

We report a fundamental morphological instability of constrained 3D microtissues induced by a positive chemomechanical feedback between actomyosindriven contraction and the mechanical stresses arising from the constraints. Using a 3D model for mechanotransduction we find that perturbations in the shape of contractile tissues grow in an unstable manner leading to formation of "necks" that lead to the failure of the tissue by narrowing and subsequent elongation. The magnitude of the instability is shown to be determined by the level of active contractile strain, the stiffness of the extra cellular matrix (ECM) and the components of the tissue that acts in parallel with the active component and the stiffness of the boundaries that constrain the tissue. A phase diagram that demarcates stable and unstable behavior of 3D tissues as a function of these material parameters is derived. The predictions of our model are verified by analyzing the necking and failure of normal human fibroblast (NHF) tissue constrained in a loopended dogbone geometry and cardiac microtissues constrained between microcantilevers. By analyzing the time evolution of the morphology of the constrained tissues we have quantitatively determined the chemomechanical coupling parameters that characterize the generation of active stresses in these tissues. More generally, the analytical and numerical methods. we have developed provide a quantitative framework to study how contractility can influence tissue morphology in complex 3D environments such as morphogenesis and organogenesis.
Compartmentalization of GABAergic Inhibition by Dendritic Spines

γ-aminobutyric acid-mediated (GABAergic) inhibition plays a critical role in shaping neuronal activity in the neocortex. Numerous experimental investigations have examined perisomatic inhibitory synapses, which control action potential output from pyramidal neurons. However, most inhibitory synapses in the neocortex are formed onto pyramidal cell dendrites, where theoretical studies suggest they may focally regulate cellular activity. The precision of GABAergic control over dendritic electrical and biochemical signaling is unknown. By using cell type-specific optical stimulation in combination with two-photon calcium (Ca(2+)) imaging, we show that somatostatin-expressing interneurons exert compartmentalized control over postsynaptic Ca(2+) signals within individual dendritic spines. This highly focal inhibitory action is mediated by a subset of GABAergic synapses that directly target spine heads. GABAergic inhibition thus participates in localized control of dendritic electrical and biochemical signaling.
Performance--Self-Esteem and Perceptions of Leadership Emergence: A Comparative Study of Men and Women.

This study examines the leadership ratings and perceived leadership emergence of men and women with either high or low performance‐self‐esteem. Results confirmed hypotheses that performance‐self‐esteem has a substantial impact on an individual's chances of being perceived as a group's emergent leader, his or her ratings by other group members and trained observers on key leadership variables, and his or her self‐assessment as a group participant. Findings also provided evidence for a commonly held view of leadership in ad hoc groups as being procedurally focused.
Luminescent properties of x-irradiated rare-earth-doped barium copper oxides

Thermally stimulated luminescence (TSL) of x-ray-induced defects in R--Ba--Cu--O (R = Gd, Ho, and Eu) has been measured. In the interval 25--400 /sup 0/C, Ho- and Eu-doped samples exhibit similar TSL with peaks at 65, 135, and 185 /sup 0/C. The GdBa/sub 2/Cu/sub 3/O/sub x/ has, in addition to the three aforementioned peaks, a maximum at 310 /sup 0/C. All TSL peaks are attributed to recombination of F/sup +//sub s/- and F/sub s/- center electrons with V/sub s/- type holes, requiring typical thermal activation energies 0.5--1.0 eV. Spectral emission data support this conclusion. Irreversible quenching of TSL is found to occur in each sample. It is postulated that adsorbed oxygen molecules interact with radiation-induced F/sup +//sub s/ and F/sub s/ centers to produce O/sup -//sub 2/ and O/sup 2-//sub 2/ molecular ions, respectively, thereby reducing the surface oxygen vacancy concentration and quenching the luminescence. In addition to activation energies, other TSL parameters are extracted from the data. It is suggested that surface TSL in these oxide superconductors is independent of rare-earth dopant.
Molecular dynamics simulations of relaxation in stretched PVDF nanofibers

Abstract We analyze by means of atomistic molecular-dynamics simulations and analytical theory the relaxation processes that occur following the formation of thin electrospun nanofibers of poly(vinylidene fluoride). We find the relaxation processes that follow formation of a nanofiber to be of two types. One type is a rapid rotation of chain segments that gives rise to twist defects at various points along the chain. In the second type, twist defects translate until they are near to other, similar defects, at which point they stop and assemble into twist boundaries that include several chains. This sequence is reflected in the time variation of the distribution of dihedral angles of the chains, where an initial broadening of the distribution about the trans conformation is followed by a narrowing that restores the distribution almost to its original form. Reducing the radius of the nanofiber to below 2 nm lowers the stability of the ordered phase, so that even at zero temperature the ferroelectric order quickly diminishes, while at room temperature the relaxation times become very short. Regardless of how small the fiber diameter is, however, twist boundaries continue to form.
Pores of annulate lamellae and nuclei bind wheat germ agglutinin and monoclonal antibody similarly

Abstract Both a monoclonal antibody against rat liver nuclear pore complex proteins and a wheat germ agglutinin (WGA) bind to the pore regions of nuclear envelopes and annulate lamellae from extracts of P3J, a cultured cell line derived from ascites of a Burkitt's lymphoma. In this system it is possible to induce large numbers of annulate lamellae whose functions are unknown but may include providing a source of nuclear envelopes. The antibody and the lectin bind fibrous material at pore margins on both sides of the nuclear envelope and cisternae of the annulate lamellae. Treating extracts of PU cells with protease removes the fibrous material from pore regions and prevents binding by WGA. Extracts treated with RNAse still possess fibrous material at the pore regions of both organelles that binds WGA. The similarity of the binding of the two types of pores and the specificity of binding argue that annulate lamellae may be a reserve form of nuclear envelopes. Binding of WGA is prevented by preincubating the extracts in N-acetylglucosamine or N,N,N-triacetylchitotriose, suggesting that both pore complexes include one or more N-acetylglucosamine-containing proteins.
Subjective analysis of penile implant

Based on 105 responses a questionnaire was evaluated describing the subjective reactions of patients and their partners after having had a penile implant inserted between 1972 and 1979. The conclusion was that the penile implant provided a good solution for impotence, and that it produced and improved the sexual relationship. The quality of life also was improved.
Barriers and decisions when answering clinical questions at the point of care: a grounded theory study.

Importance Answering clinical questions affects patient-care decisions and is important to continuous professional development. The process of point-of-care learning is incompletely understood. Objective To understand what barriers and enabling factors influence physician point-of-care learning and what decisions physicians face during this process. Design Focus groups with grounded theory analysis. Focus group discussions were transcribed and then analyzed using a constant comparative approach to identify barriers, enabling factors, and key decisions related to physician information-seeking activities. Setting Academic medical center and outlying community sites. Participants Purposive sample of 50 primary care and subspecialist internal medicine and family medicine physicians, interviewed in 11 focus groups. Results Insufficient time was the main barrier to point-of-care learning. Other barriers included the patient comorbidities and contexts, the volume of available information, not knowing which resource to search, doubt that the search would yield an answer, difficulty remembering questions for later study, and inconvenient access to computers. Key decisions were whether to search (reasons to search included infrequently seen conditions, practice updates, complex questions, and patient education), when to search (before, during, or after the clinical encounter), where to search (with the patient present or in a separate room), what type of resource to use (colleague or computer), what specific resource to use (influenced first by efficiency and second by credibility), and when to stop. Participants noted that key features of efficiency (completeness, brevity, and searchability) are often in conflict. Conclusions and Relevance Physicians perceive that insufficient time is the greatest barrier to point-of-care learning, and efficiency is the most important determinant in selecting an information source. Designing knowledge resources and systems to target key decisions may improve learning and patient care.
Extinction following Negatively Correlated Reinforcement

Rats that were rewarded only if their speed in an alley fell within a narrow band extinguished at a relative rate comparable to that of rats that received the same frequency of reward uncorrelated with speed. This is consistent with the proposition that each response dimension is independently determined by its correlation with reward.
The War: The Story of One Rural College's Battle for Survival.

This paper intends to describe the recent experience of a small, rural, two-year technical college. After four decades of success, the college had found itself in a difficult situation with a substantial loss in enrollment and diminished state and local support, coupled with low campus employee morale. In response, the college team closed ranks and rallied in what has become quite a proactive and successful effort to reinvent itself. After nearly six years of working to correct a number of issues that had led to decline, the college gained a general sense of stabilization, made advances in existing and new academic programs and technical innovation, dramatically increased diversity, and enhanced student life opportunities with the addition of an array of successful athletic programs. The college has seen significant increases in enrollment, state and national recognition for technical initiatives, and a collectively positive sense of the future.
Convex Subspace Routing (CSR): Routing via anchor-based convex virtual subspaces in sensor networks

Convex Subspace Routing (CSR) is a novel approach for routing in sensor networks using anchor-based virtual coordinates. Unlike geographical routing schemes that require physical location information of nodes, obtaining which is often difficult, error-prone and costly, the Virtual Coordinate (VC) based schemes simply characterize each node by a vector of shortest hop distances to a selected subset of nodes known as anchors. Even though VC based routing (VCR) schemes benefits from having connectivity information implicitly embedded within the VCs, VCs lack the directional information available with physical coordinates. The major issues affecting routing using VCs are addressed. Due to local minima problem in the virtual space, the VCR schemes rely on backtracking or hill climbing techniques to overcome the local minima. Convex Subspace Routing, in contrast, avoids using anchors that cause local minima. It dynamically selects subsets of anchors that define subspaces to provide convex distance functions from source to destination. Consequently, it is less sensitive to anchor placement and over anchoring, and does not require tracking route history for backtracking, resulting in shorter packet lengths and energy efficient operation. Three techniques for selection of convex subspaces are proposed and evaluated. Performance evaluation for several different network topologies indicates that CSR significantly outperforms the existing VCR scheme, Logical Coordinate Routing (LCR), while being competitive with geographic coordinate based Greedy Perimeter Stateless Routing (GPSR), even though latter makes use of node location information.
Optimization of a Hurricane Track Forecast Model with the Adjoint Model Equations

Abstract The method of model fitting, or “adjoint method,” is tested in a barotropic hurricane track forecast model. The model vorticity field at the beginning of an assimilation period is adjusted to minimize a cost function that is defined as the squared difference between the model vorticity and the vorticity from a sequence of analyses separated by 12 h. After the cost function is minimized, the model vortex clearly follows the observed storm track during the assimilation period, indicating that information about the past track of the storm is being included in the model solution. Track forecasts using the assimilation procedure are compared with control forecasts where the model is initialized with a single analysis at the end of the assimilation period. Results from a series of 18 forecasts for Hurricane Hugo (1989) show that with a 12-h assimilation period the average track forecast errors are smaller than those of the control forecasts out to about 48 h. The forecast errors using a 24-h assimilati...
Inactivation of aflatoxin b1 mutagenicity by thiols

Abstract The mutagenicity of aflatoxin B 1 to Salmonella typhimurium strain TA98 decreased rapidly upon exposure of aflatoxin B 1 to various thiols in aqueous solution. Mutagenic activity was reduced to control values within 24 hr with N -acetyl- l -cysteine (NAC), N -2-mercaptopropionylglycine (MPG), mercaptoethanol, reduced glutathione or mercaptopropionic acid at pH values near 4. Mercaptoacetic acid, mercaptosuccinic acid, cysteine, acetyl- d , l -homocysteine thiolactone, cysteine methyl ester, d -penicillamine and β -mercaptoethylamine were less effective. Relatively high thiol concentrations ( ⪖ 0.25 m ) were required to achieve complete inactivation within 24 hr with the thiols tested. The inactivation rate was strongly dependent on thiol concentration and pH, but was relatively independent of the aflatoxin concentration under the conditions examined. With MPG and NAC reaction rates were much slower at neutral pH values than at pH's between 3 and 4. HPLC and thin-layer Chromatographic examination of aflatoxin B 1 solutions partially inactivated with NAC revealed the formation of a new product at a rate that correlated with the disappearance of aflatoxin B 1 and the loss of mutagenic activity. This reaction product has not yet been identified, but the evidence suggests that it is the product of an addition of the thiol at the difuran region of the aflatoxin.
Cryopreservation of Synchytrium solstitiale In Planta

The fungus Synchytrium solstitiale is a candidate for use as a biocontrol agent against Centaurea solstitialis. This obligate parasite can be propagated only in planta, which necessitates development of a method for preserving cultures for longer periods of time for routine biological studies and shipment to other laboratories. Normally, sporangia embedded within the plant tissue release zoospores when submersed in water at temperatures above freezing. To examine what chemicals might inhibit zoospore release, infected tissue was exposed to different suspensions of fungicides. Cycloheximide and benomyl completely inhibited zoospore release or immediately induced encystment from tissue stored in these two chemicals, respectively. A few zoospores were released in suspensions of iprodione and propionic acid but were not motile. However, when tissue stored in iprodione or propionic acid was transferred to fresh distilled water, abundant active zoospores were released. Freezing the infected tissue at different temperatures in different cryoprotectants also affected the release of motile zoospores. Infected C. solstitialis tissue was immersed in water, water plus iprodione, methanol, ethylene glycol, dimethyl sulfoxide, glycerol, skim milk, trehalose, or sucrose and subjected to different temperatures for various periods of time. Some treatments protected the viability of the fungus for a shorter period of time whereas other treatments completely inhibited release. The best results were obtained when infected tissue was stored at -2°C in 0.5 M sucrose where active zoospores were released after 12 weeks of storage. Overall, results obtained from this study demonstrate a technique for long-term storage of S. solstitiale.
Characterization of the Structure and Surface Acidity of Hydroxychromium Taeniolites

Hydroxychromium taeniolites were prepared using hydroxychromium solutions with a OH/Cr content of about 1 and 2. To study the influence of oxidation on the properties of the synthesized materials, the samples were heated in air and, for comparison, in vacuum. Structural characteristics were obtained using X-ray diffraction and sorption of nitrogen. The surface chemistry was evaluated using potentiometric titration. The pKa distributions calculated from potentiometric titration data revealed peaks characteristic of chromium polymers (CrIII) for the initial samples and peaks with a pKa corresponding to chromic acid (CrVI) for the oxidized samples. In addition, the pKa distributions also provide evidence for inner-sphere complexation of the interlayer Cr with siloxane oxygen. The materials' acidity and structure, obtained from X-ray diffraction and sorption of nitrogen, demonstrate that chromium species are adsorbed mainly on the external surface of taeniolite and that the properties of the final products de...
The Effects of Muscarinic Cholinergic Receptor Blockade in the Rat Anterior Cingulate and Prelimbic/Infralimbic Cortices on Spatial Working Memory

Previous findings indicate that cholinergic input to the medial prefrontal cortex may modulate mnemonic processes. The present experiment determined whether blockade of muscarinic cholinergic receptors in the rodent anterior cingulate and prelimbic/infralimbic cortices impairs spatial working memory. In a 12-arm radial maze, a working memory for spatial locations task was employed using a continuous recognition go/no-go procedure. Rats were allowed to enter 12 arms for a reinforcement. Of the 12 arm presentations, 3 or 4 arms were presented for a second time in a session that did not contain a reinforcement. The number of trials between the first and second presentations of an arm ranged from 0 to 6 (lags). Infusions of scopolamine (1, 5, and 10 μg), a muscarinic cholinergic antagonist, into the prelimbic/infralimbic cortices, but not the anterior cingulate cortex, significantly impaired spatial working memory in a lag- and dose-dependent manner. The deficit induced by scopolamine (10 μg) was attenuated by concomitant intraprelimbic/infralimbic injections of oxotremorine (2 μg), a muscarinic cholinergic agonist. A separate group of rats was tested on a successive spatial discrimination task. Injections of scopolamine (1, 5, and 10 μg) into the prelimbic/infralimbic cortices did not impair performance on the spatial discrimination task. These findings suggest that muscarinic transmission in the prelimbic/infralimbic cortices, but not the anterior cingulate cortex, is important for spatial working memory.
The congenitally bicuspid aortic valve. A study of 85 autopsy cases.

Abstract Clinical and necropsy observations are described in 85 autopsy cases in which the subjects had congenially bicuspid aortic valves. Sixty-one subjects had aortic stenosis with or without aortic regurgitation; 11, pure aortic regurgitation; and 13, unexpectedly, had a congenitally bicuspid aortic valve that apparently had functioned normally. The average age at death in patients with stenotic valves was 49 years, and in those with pure regurgitation, 31 years. Aortic valvular calcific deposits occurred in 59 of 61 patients with stenosis but was minimal or absent in the patients with pure regurgitation or normally functioning valves. Infective endocarditis appeared responsible for incompetency in 8 of 11 patients with pure regurgitation. Five of 61 patients with stenosis had had infective endocarditis, but infection occurred on a previously heavily calcified valve in only 1 patient. Sixty-nine of the 72 patients with functionally abnormal valves were observed in a study of 400 autopsy cases; all subjects were over age 14 years, with severe valvular cardiac disease. The 13 functionally normal valves were found during study of 1,440 necropsy cases in which the subjects were free of other valvular or septal defects. The bicuspid aortic valve is the most frequent congenital malformation of the heart or great vessels. It occurs in over 50 percent of patients with anatomically isolated aortic stenosis and in about 25 percent of patients with clinically pure aortic regurgitation. It is not certain why 1 congenitally bicuspid valve becomes severely scarred, calcified and stenotic, another only mildly scarred and incompetent, another the site of infection, and why another remains free of these complications during life.
Role of lymphadenectomy in the management of grossly apparent advanced stage epithelial ovarian cancer.

Objective The purpose of this study was to determine the factors that are related to the performance of lymph node assessment and its impact on prognosis in ovarian cancer. Study design This was a retrospective analysis of stage IIIC/IV epithelial ovarian cancer in patients who had undergone primary surgery between 1994 and 1998. Simple statistics and univariate and multivariable analysis were performed. Results Two hundred nineteen patients met the inclusion criteria; lymph node assessment was performed for 93 of these patients (41%). Sixty-one patients (65.5%) underwent complete pelvic and para-aortic lymphadenectomy, and 32 patients (34.5%) underwent a more limited lymph node sampling. In patients with residual disease >1 cm, lymph node assessment was an independent predictor of outcome. In this same subgroup, lymphadenectomy appeared to be superior to lymph node sampling (5-year overall survival, 50% (lymphadenectomy) vs 33% (lymph node sampling) vs 29% (no lymph node assessment); P = .01). Considering survival of the subgroup who underwent lymph node assessment, we observed a significantly worse outcome for those with lymphatic involvement (5-year overall survival, 31.5% [positive for nodal metastases] vs 54% [negative for nodal metastases]; P = .003). Although multiple factors were correlated with the decision to perform lymph node assessment in univariate analysis, only the surgeon ( P P = .004), American Society of Anesthesiology 1 or 2 ( P = .004), and the absence of carcinomatosis ( P = .0002) were independent factors in the multivariable analysis. Further, if lymph node assessment was performed, the decision to do lymphadenectomy versus lymph node sampling was associated independently with the surgeon ( P P P Conclusion Removal of obviously involved lymph nodes in patients with residual disease near 1 cm and lymphadenectomy for patients with complete or near complete resection of abdominal disease appears to be justified. A lack of standard recommendation in advanced ovarian cancer results in wide variations that are based on individual preference in addition to logical factors.
Evolutionary biology: How insects lose their limbs

Evolution has produced marvellous variety in the arthropods, and in their various appendages. The evolutionary processes are themselves proving highly diverse.
Profilin and actin-depolymerizing factor: modulators of actin organization in plants

A striking feature of the eukaryotic actin cytoskeleton is its ability to undergo dramatic reorganization in response to internal and environmental stimuli. In plant cells, several cellular processes depend on, or are coincident with, reorganization of the actin cytoskeleton, including division, differentiation, light-induced plastid migration, wound repair and response to pathogen attack. Understanding how the actin cytoskeleton responds to these internal and extracellular factors requires a detailed understanding of the molecular mechanisms that coordinate actin polymerization and depolymerization. There is increasing evidence that the small actin-binding proteins profilin and actin-depolymerizing factor regulate actin dynamics in plant cells. These proteins may serve to integrate signaling cues and translate this information to remodel the cytoplasmic architecture.
The effect of diphenylhydantoin on sleep in the cat

Abstract 1. 1. The effect of prolonged (11–24 days) administration of diphenylhydantoin (DPH) on sleep patterns of five cats was studied. 2. 2. DPH suppressed rapid eye movement (REM) sleep time significantly below pre-drug baseline levels. REM periods became shorter and less frequent. There was no consistent change in NREM sleep time. Lateral geniculate monophasic sharp wave activity during REM periods (investigated in two cats) was not markedly affected by the drug. 3. 3. Following suppression, there was no sign of the usual compensatory rebound in REM sleep time. 4. 4. DPH appears to interfere with the mechanisms responsible for REM sleep and seems to offset factors which lead to rebounds, as when REM deprivation is accomplished by other means.
A novel technique for gentle lysis of eucaryotic cells Isolation of plasma membranes from Dictyostelium discoideum

Abstract A new type of lysis technique for eucaryotic cells was used for the isolation of highly purified plasma membranes from Dictyostelium discoideum . Suspensions of amoebae (10 μm diameter) were lysed by forced passage through Nuclepore filters with pores of 5 μm diameter. Virtually complete lysis was effected with minimal fragmentation of lysosomes and mitochondria. By subsequent differential and isopycnic centrifugation, 25–35-fold purified plasma membranes were isolated in 35–50% yield for cells from vegetative through tip formation stages of development. Lysis, yield and purity were enhanced by use of slightly alkaline conditions. Contamination with other organelles and with soluble proteins was found to be minimal. At each developmental stage, the plasma membranes generated three closely-spaced, equally pure bands in a sucrose density gradient. Two-dimensional electrophoretic analysis of the individual bands showed that they were very similar to each other, indicating that the density differences are not due to gross differences in protein composition.
Bone intrinsic material properties in three inbred mouse strains.

This study assessed genetically based differences in intrinsic material properties of both cortical and cancellous bone in adult females of three inbred mouse strains [C57BL/6J (B6), DBA/2J (D2), C3H/HeJ (C3)]. These mouse strains have previously been shown to differ in bone mineral content (BMC) and density (BMD). Distal femoral cancellous bone and midshaft cortical bone in femurs and tibias were assessed for intrinsic material properties using nanoindentation technique. The intrinsic material properties tested were modulus (Eb) and hardness (H) of the midshaft femoral and tibial cortical bone cross sections and of cancellous bone in the distal femur. Both femoral and tibial cortical bone intrinsic material properties were different among the three inbred mouse strains. Femoral modulus and tibial hardness in cortical bone and hardness in cancellous bone were either greatest or showed greater trends in C3 mice as compared to both D2 and B6. Cancellous bone modulus was similar among the three mouse strains. With the exception of the D2 mice, the femoral and tibial cortical modulus were similar within each mouse strain. The tibial cortical modulus was smaller than the femoral cortical modulus for D2 mouse strain. The cortical hardness was greater in tibiae compared with that in femora within each mouse strain. The nanoindentation data suggest that cortical and cancellous intrinsic material properties are influenced by the genetic background of the inbred mouse strains. The inbred mouse strain-related intrinsic material property phenotype can be used to locate responsible quantitative trait loci (QTLs) in future studies of recombinant inbred mouse strains.
Sanfilippo A Syndrome SULFAMIDASE DEFICIENCY IN CULTURED SKIN FIBROBLASTS AND LIVER

The Sanfilippo A syndrome is an autosomal recessive mucopolysaccharidosis characterized clinically by severe mental retardation and biochemically by storage in tissue and excretion in urine of excessive amounts of heparan sulfate. Since sulfamide groups are present in heparan sulfate, a sulfamidase deficiency could explain the impaired degradation of this polysaccharide. To investigate the enzymic basis of this disease, assays for sulfamidase were performed. Extracts of cultured fibroblasts and post-mortem liver were prepared by suspension of tissues in acetate: NaCl buffer, pH 4.5, containing Triton X-100 (Rohm and Haas Co., Philadelphia, Pa.), sonication, and centrifugation at 10,000 g. The supernatant fluid was incubated with [(35)S]-N-sulfated heparin. The release of inorganic sulfate after 18 h of incubation was determined by chromatography on Sephadex G-25. The liver and fibroblast extracts of patients with the Sanfilippo A syndrome showed a deficiency of sulfamidase. The quantity of heparan sulfate in fibroblasts derived from patients with Sanfilippo A, Hurler's and Hunter's diseases was found to be 7-10%, while it was about 1.25% of the total glycosaminoglycans in fibroblasts of normal controls.
THE DYNAMIC PLASTIC BEHAVIOR OF FULLY CLAMPED RECTANGULAR PLATES

Abstract An experimental investigation was undertaken in order to study the behavior of fully-clamped rectangular plates when subjected to uniformly distributed impulsive velocities. The total energy of the dynamic loads was sufficiently large to cause plastic flow of the plate material and maximum permanent deflections from 0.2 to nearly seven times the corresponding plate thicknesses. All the rectangular plates had the same aspect ratio (B/L = 0.593) but various thicknesses (H), and were made from either hot-rolled mild steel or aluminum 6061-T6. The permanent deformed profiles of the plates are similar to the shape of the velocity field used by Wood [11] for calculating the minimum upper bound to the collapse pressure of a fully-clamped rectangular plate loaded with a uniformly distributed time-independent pressure. It is observed that a modification of the bending only prediction of Martin [13] provides adequate engineering estimates of the maximum permanent deflections up to the order of one-half of the corresponding plate thickness. For larger deflections, it is necessary to include the influence of geometry changes; and in the case of mild steel, material strain-rate sensitivity as well.
Investigation of the effects of folate deficiency on embryonic development through the establishment of a folate deficient mouse model.

Background Folic acid (FA) has been shown to reduce the incidence of neural tube, craniofacial, and cardiovascular defects and low birth weight. The mechanism(s) by which the vitamin is effective, however, has not been determined. Therefore, a folic acid deficient mouse model was developed. Methods To create a folic acid deficiency, ICR female mice were placed on a diet containing no FA and including 1% succinyl sulfathiazole (SS) for 4 weeks before mating. Control mice were fed diets with either: 1) FA and 1% SS [+SS only diet]; 2) FA [normal diet]; or 3) a breeding diet. Dams and fetuses were examined during various days of gestation. Results Blood analysis showed that by gestational day 18, plasma folate concentrations in the −FA+SS fed dams decreased to 1.13 ng/ml, a concentration approximately 3% of that in breeding diet fed dams (33.24 ng/ml) and 8% of that in +SS only/normal fed dams (13.59 ng/ml). RBC folate levels showed a similar decrease, whereas homocysteine concentrations increased. Reproductive outcome in the −FA+SS fed dams was poor with increased fetal deaths, decreased fetal weight, and delays in palate and heart development. Conclusions Female mice fed a folic acid deficient diet and 1% succinyl sulfathiazole exhibited many of the characteristics common to human folic acid deficiency, including decreased plasma and RBC folate, increased plasma homocysteine, and poor reproductive outcomes. Thus, an excellent model has been created to investigate the mechanism(s) underlying the origin of birth defects related to folic acid deficiency. Teratology 65:219–227, 2002. © 2002 Wiley-Liss, Inc.
Eutectic bonding of a Ti sputter coated carbon aerogel wafer to an Ni foil

The formation of high energy density, storage devices is achievable using composite material systems. Alternate layering of carbon aerogel wafers and Ni foils with rnicroporous separators is a prospective composite for capacitor applications. An inherent problem exists to form a physical bond between Ni and the porous carbon wafer. The bonding process must be limited to temperatures less than 1000{degrees}C, at which point the aerogel begins to degrade. The advantage of a low temperature eutectic in the Ni-Ti alloy system solves this problem. Ti, a carbide former, is readily adherent as a sputter deposited thin film onto the carbon wafer. A vacuum bonding process is then used to join the Ni foil and Ti coating through eutectic phase formation. The parameters required for successfld bonding are described along with a structural characterization of the Ni foil-carbon aerogel wafer interface.
Strange star surface: a crust with nuggets.

We reexamine the surface composition of strange stars. Strange quark stars are hypothetical compact stars which could exist if strange quark matter was absolutely stable. It is widely accepted that they are characterized by an enormous density gradient (10{sup 26} g/cm{sup 4}) and large electric fields at the surface. By investigating the possibility of realizing a heterogeneous crust, comprised of nuggets of strange quark matter embedded in an uniform electron background, we find that the strange star surface has a much reduced density gradient and negligible electric field. We comment on how our findings will impact various proposed observable signatures for strange stars.
Action and Reaction: The Biological Response to siRNA and Its Delivery Vehicles

RNA interference (RNAi)-based therapeutics have significant potential for the treatment of human disease. Safe and effective delivery of RNA to target tissues remains a major barrier to realizing its clinical potential. Several factors can affect the in vivo performance of short interfering RNA (siRNA) delivery formulations, including siRNA sequence, structure, chemical modification, and delivery formulation. This review provides an introduction to the principles underlying the pharmacokinetics and pharmacodynamics of systemically administered siRNA and its delivery formulations, including the factors that lead to its degradation, clearance, and tissue uptake, as well as its potential for immunogenicity, toxicity, and off-target effects within the body.