cssi/SciSciGPT-SciSciNet huggingface dataset:
Autophagy wins the 2016 Nobel Prize in Physiology or Medicine: Breakthroughs in baker's yeast fuel advances in biomedical research

Autophagy is an ancient pathway in which parts of eukaryotic cells are self-digested within the lysosome or vacuole. This process has been studied for the past seven decades; however, we are only beginning to gain a molecular understanding of the key steps required for autophagy. Originally characterized as a hormonal and starvation response, we now know that autophagy has a much broader role in biology, including organellar remodeling, protein and organelle quality control, prevention of genotoxic stress, tumor suppression, pathogen elimination, regulation of immunity and inflammation, maternal DNA inheritance, metabolism, and cellular survival. Although autophagy is usually a degradative pathway, it also participates in biosynthetic and secretory processes. Given that autophagy has a fundamental role in many essential cellular functions, it is not surprising that autophagic dysfunction is associated with a wide range of human diseases. Genetic studies in various fungi, particularly Saccharomyces cerevisiae, provided the key initial breakthrough that led to an explosion of research on the basic mechanisms and the physiological connections of autophagy to health and disease. The Nobel Committee has recognized this breakthrough by the awarding of the 2016 Nobel Prize in Physiology or Medicine for research in autophagy.
A Controllably-Sized Synthetic Cell System to Investigate the Geometric Dependence of Intracellular Signaling

To grow and divide, cells must accurately measure their dimensions. Computational studies suggest that signal flux through kinase and GTPase pathways depends on cell size and shape. For example, a plasma membrane-localized GEF and a cytoplasm-localized GAP are predicted to create a gradient of GTPase activation, such that the fraction of activated GTPase will inversely correlate with cell size. However, it has proven challenging to test these predictions in higher eukaryote cell culture systems. Therefore, we recently developed an experimental synthetic cell platform that enables broad control of cellular dimensions; diameters can be tuned from 5 - 500 microns using microfluidic encapsulation. To mimic cellular processes, these cell-like compartments are filled with cytoplasmic extracts capable of carrying out complex cell cycle reactions in vitro. Importantly, the lipid monolayer is tunable, enabling control of both the physical dimensions of the compartment and chemical composition of the boundary. Additionally, we have implemented in vitro light-inducible dimerization tools to control protein localization to organelles and the lipid monolayer boundary. By combining our novel synthetic cell platform with optogenetics we now are able to quantify the relationship between cell geometry and the kinetics of intracellular signaling. Our goals are to measure the rates of RhoA GTPase activation as a function of cell size, and determine how the spatial patterning of GEFs and GAPs dictates the sensitivity of GTPase signaling to cell size. I will present our progress in implementing blue-light dependent protein inside our synthetic cell-like system, and the application of these tools to generate tunable patterns of RhoA and Cdc42 activation. I will also describe our efforts to engineer orthogonal cell size sensors. These studies provide new insights on the mechanisms by which signaling pathways measure and respond to alterations in cell size.
Freeze–Thaw Performance of Fly Ash–Stabilized Materials and Recycled Pavement Materials

AbstractA comprehensive research was conducted to study the performance of a variety of stabilized geomaterials against the freeze–thaw (F–T) cycling process. Also included were unstabilized recycl...
The Corporate Social Responsibility Policies and Their Impact on Business Practice

The principle purpose of this research is to find out the importance of corporate social responsibility in this modern world and analyse their impact on business practice and key stakeholders, mainly focus on the firms that they belong.
Suppressed oxygen extraction and degradation of LiNi x Mn y Co z O 2 cathodes at high charge cut-off voltages

The capacity degradation mechanism in lithium nickel–manganese–cobalt oxide (NMC) cathodes (LiNi1/3Mn1/3Co1/3O2 (NMC333) and LiNi0.4Mn0.4Co0.2O2 (NMC442)) during high-voltage (cut-off of 4.8 V) operation has been investigated. In contrast to NMC442, NMC333 exhibits rapid structural changes including severe micro-crack formation and phase transformation from a layered to a disordered rock-salt structure, as well as interfacial degradation during high-voltage cycling, leading to a rapid increase of the electrode resistance and fast capacity decline. The fundamental reason behind the poor structural and interfacial stability of NMC333 was found to be correlated to its high Co content and the significant overlap between the Co3+/4+ t2g and O2− 2p bands, resulting in oxygen removal and consequent structural changes at high voltages. In addition, oxidation of the electrolyte solvents by the extracted oxygen species generates acidic species, which then attack the electrode surface and form highly resistive LiF. These findings highlight that both the structural and interfacial stability should be taken into account when tailoring cathode materials for high voltage battery systems.
Accuracy of frozen section in determining meningioma subtype and grade.

Abstract Frozen section intraoperative consultation is a well-established means of evaluating brain tumors at the time of surgery. Limitations to the procedure are also well recognized resulting in less than perfect specificity of diagnosis. This study retrospectively reviewed 424 consecutive meningioma cases (N = 310 females; mean age 57.3 years) to examine concordance between frozen section evaluation of meningioma subtype and grade as compared with the final diagnosis subtype and grade. A discrepancy between frozen section diagnosis and final diagnosis was observed in 114 (26.9%) of cases. Of the WHO grade I subtypes, the most common discrepancy involved transitional meningiomas (N = 31) which were most commonly diagnosed at frozen section as either fibrous (N = 18) or meningothelial (N = 13) meningiomas. None of the grade I tumors were diagnosed as higher grade lesions. Of the higher grade meningiomas (WHO grade II and III) (N = 145) reviewed, concordance between tumor type and grade was seen in only 26.2% of cases; most commonly, 73/98 atypical meningiomas were under-graded as some subtype of WHO grade I meningioma (71/73 cases). In conclusion, discrepancies at frozen section with respect to accurately identifying higher grade meningiomas and higher grade meningioma subtypes are common and are generally due to tumor sampling and heterogeneity.
Locating Imagination: The Inceptive Field Productivity and Differential Topology of Imagining (Plus What It Means to Play a Game)

One of the first tasks in investigating imagination is to determine what kind of phenomenon it is and to work out appropriate conceptual and descriptive vocabulary for its basic features. Traditionally it has been understood as dependent on sense perception and related to memory. The skeptical empiricist David Hume (1711–1776) laid down the rule that it is impossible for us to imagine what we have not already experienced through sense. But a thought experiment he devised—showing that if we use arrays to organize phenomena we have already experienced, we can fill gaps by imagination—can generate a limitless number of exceptions to his rule. This suggests a non-Humean possibility: image-appearances are not isolated data but take place in structured fields of interconnected experience. Sensation, imagination, and memory all produce or require such fields as the experiential place necessary for the emergence of appearances. Fields can be conceptually marked and articulated, which yields a matrix or topography. It is this conceptual marking of a field—conceptual topology—that makes images describable, knowable, and systematically variable. The structure of the articulated matrix in a field can often itself be experienced as a more abstract field, so that we come to grasp phenomena in a biplanar way: one field in terms of another. This phenomenon of projective biplanar field experience is cognitively productive and also yields insight into “fields” as diverse as game playing and artistic production.
Measurements of In-Situ Stress, Fracture Distribution, Permeability, and Sonic Velocity

Recent in-situ measurements attempting to characterize fractured crystalline rock are reported. The parameters we have chosen to study, in-situ stress, macroscopic fracture distribution, seismic velocity, and bulk permeability are all quite important for commercial development of geothermal energy.
Naturally Occurring Spinal Injury in the Dog as a Model for Humans

The two most common causes of naturally produced spinal cord injury in canines are fracture/dislocation of the vertebral column (usually resulting from vehicle impact) and explosive intervertebral disc herniations. In the former, spinal injury usually results in complete transection of the dog’s spinal cord, a condition that is more severe than observed in human clinical cases (with the exception of wartime injuries) (Toombs et al. 1993; Bunge et al. 1993; Tuszynski 1999).
Pyrroloquinoline quinone (PQQ) stimulates mitochondrial biogenesis

PQQ is found in numerous foods. Oxidative metabolism can be depressed when diets fed to mice and rats are devoid of PQQ. Gene array and QRTPCR studies indicate that neo- and perinatal PQQ deficienc...
PIK3IP1- A novel negative regulator of PI3K

Phosphatidylinositide-3-Kinases (PI3Ks) are a family of lipid kinases that play important intracellular signaling roles in cellular functions such as cell proliferation, motility, growth, intracellular trafficking, differentiation and survival. PI3K produces PIP3 which further facilitates the activation of downstream effectors such as Akt and PDK1. These effectors facilitate the cellular processes associated with PI3K activity. Conversely, because of the nature of PI3Ks roles, dysregulation of PI3K is implicated in many cancers. PTEN, SHIP and INPP4B are negative regulators of PI3K activity that function downstream of PI3K and have been shown to act as tumor suppressors. Recently, PI3K Interacting Protein 1 (PIK3IP1), a novel negative regulator that functions upstream and proximal to PI3K, has been identified. PIK3IP1 is a transmembrane protein that down-regulates PI3K activity, leading to reduced Akt phosphorylation. Our lab recently showed that PIK3IP1 can inhibit TCR signaling and TCR activation. To better understand the role of PIK3IP1 in immune cells, we have begun to carefully define the roles of the various domains that comprise PIK3IP1. In addition, we have produced a PIK3IP1 ecto-domain Fc fusion protein, which we have used to develop monoclonal antibodies against PIK3IP1. This ecto-domain Fc fusion protein is also being used to define possible ligands for PIK3IP1. Finally, we have obtained knockout mice lacking expression of PIK3IP1 in T cell and mast cell compartments, to better define the requirements for PIK3IP1 in primary T and mast cells.
Clinical indicators of paraplegia underplay universal spinal cord neuronal injury from transient aortic occlusion.

Abstract Paraplegia following complex aortic intervention relies on crude evaluation of lower extremity strength such as whether the patient can lift their legs or flex the ankle. Little attention has been given to the possible long-term neurologic sequelae following these procedures in patients appearing functionally normal. We hypothesize that mice subjected to minimal ischemic time will have functional and histological changes despite the gross appearance of normal function. Male mice underwent 3 min of aortic occlusion (n=14) or sham surgery (n=4) via a median sternotomy. Neurologic function was graded by Basso Motor Score (BMS) preoperatively and at 24 h intervals after reperfusion. Mice appearing functionally normal and sham mice were placed on a walking beam and recorded on high-definition, for single-frame motion analysis. After 96hrs, spinal cords were removed for histological analysis. Following 3 min of ischemia, functional outcomes were split evenly with either mice displaying almost normal function n=7 or near complete paraplegia n=7. Additionally, single-frame motion analysis revealed significant changes in gait. Histologically, there was a significant stepwise reduction of neuronal viability, with even the normal function ischemic group demonstrating significant loss of neurons. Despite the appearance of normal function, temporary ischemia induced marked cyto-architectural changes and neuronal degeneration. Furthermore high-definition gait analysis revealed significant changes in gait and activity following thoracic aortic occlusion. These data suggest that all patients undergoing procedures, even with short ischemic times, may have spinal cord injury that is not evident clinically.
Planning operations in Jupiter's high-radiation environment: optimization strategies from Juno-ultraviolet spectrograph

The Juno Ultraviolet Spectrograph (Juno-UVS) is a remote-sensing science instrument onboard the Juno spacecraft that has been in polar orbit around Jupiter since July 2016. Juno-UVS measures photon events in the ultraviolet from 68 to 210 nm. It is primarily used to observe emission from the Jovian aurorae but is also sensitive to other sources, such as UV-bright stars, sky background Lyman-alpha emission, and reflected sunlight. However, Juno-UVS is also sensitive to the effects of penetrating high-energy radiation, which results in elevated count rates as measured by the instrument detector array. This radiation presents a challenge for efficiently planning the acquisition of mission science data, as data volume is a valuable (and finite) resource that can quickly be filled when the spacecraft periodically passes through regions of high radiation. This background radiation has been found to vary significantly on both short (spacecraft spin-modulated) timescales, as well as longer timescales from minutes to hours during each close approach to Jupiter. This variability has required a multipronged approach in the operation planning of hardware (such as, dynamic instrument voltage adjustment) as well as onboard software (such as, utilizing data quality factors for the selective storage of science data). We present an overview of these current mitigation/optimization techniques and planning strategies used for this instrument, which will likely also be useful for the development and operations of future instruments within high radiation space environments (e.g., the ESA JUICE mission or NASA’s Europa Clipper).
Injectable Catalyst-Free Poly(Propylene Fumarate) System Cross-Linked by Strain Promoted Alkyne–Azide Cycloaddition Click Chemistry for Spine Defect Filling

A new PPF-BCN/hyPCL32-N3 injectable system that can be cross-linked by catalyst-free, strain promoted alkyne-azide cycloaddition (SPAAC) click chemistry was developed for tissue engineering applications. The system consisted of two components: PPF-BCN, poly(propylene fumarate) (PPF) functionalized with (1R,8S,9s)-bicyclo[6.1.0]non-4-yn-9-ylmethanol (BCN-OH), and hyPCL32-N3, a hyper-branched 32-arm poly(e-caprolactone) (PCL) dendrimer functionalized with azide as the cross-linker core. Fast SPAAC click reaction allowed the desired gelation of the system without using any toxic initiator or catalyst. Compared to the conventional injectable formulation, e.g., poly(methyl methacrylate) (PMMA), our PPF-BCN/hyPCL32-N3 (abbreviated as PFCL-Click) injectable system showed enhanced biocompatibility and low heat generation during cross-linking. After reaction, the cross-linked PFCL-Click scaffolds supported excellent proliferation and differentiation of preosteoblast cells on the surface. The PFCL-Click system can be successfully injected into vertebral bodies of rabbit spine and can be monitored by X-ray imaging after incorporating zirconium dioxide (ZrO2) powder. With these unique advantages, this injectable system has promising potential for bone defect repair and other tissue engineering and regenerative medicine applications.
Self-focusing hybrid skyrmions in spatially varying canted ferromagnetic systems

Magnetic skyrmions are quasiparticle configurations in a magnetic film that can act as information carrying bits for ultrasmall, all-electronic nonvolatile memory. The skyrmions can be nucleated and driven by spin-orbit torque from a current driven in a heavy metal underlayer. Along its gyrotropic path, a Magnus force can cause a skyrmion to be annihilated at the boundaries. By combining interfacial and bulk Dzyaloshinskii-Moriya interactions (DMIs), for instance by using a B20 material on top of a heavy metal layer with high spin-orbit coupling, it is possible to engineer a hybrid skyrmion that will travel parallel to the racetrack with zero Magnus force. We show that by using a spatially varying interfacial DMI, a hybrid skyrmion will automatically self-focus onto such a track as its domain angle evolves along the path. Furthermore, using a gate driven voltage controlled magnetic anisotropy, we can control the trajectory of the hybrid skyrmion and its eventual convergence path and lane selection in a racetrack geometry.
Approximation Benefits of Policy Gradient Methods with Aggregated States.

Folklore suggests that policy gradient can be more robust to misspecification than its relative, approximate policy iteration. This paper studies the case of state-aggregation, where the state space is partitioned and either the policy or value function approximation is held constant over partitions. This paper shows a policy gradient method converges to a policy whose regret per-period is bounded by $\epsilon$, the largest difference between two elements of the state-action value function belonging to a common partition. With the same representation, both approximate policy iteration and approximate value iteration can produce policies whose per-period regret scales as $\epsilon/(1-\gamma)$, where $\gamma$ is a discount factor. Theoretical results synthesize recent analysis of policy gradient methods with insights of Van Roy (2006) into the critical role of state-relevance weights in approximate dynamic programming.
Combined Heart-Lung Transplantation: UNOS Data Analysis for Long-Term Survival Outcome

Purpose Combined heart-lung transplantation remains the only definitive therapy for patients who have both end-stage heart failure and lung failure. We analyzed UNOS data for combined heart-lung transplant data to understand survival outcomes. Methods 1,294 patients underwent simultaneous heart-lung transplantation that were reviewed from the UNOS database between October 1987 and February 2020. Descriptives and frequencies were acquired for the variables height, weight, BMI, gender, ethnicity, age, donor age, ischemic time, length of stay, previous transplant, graft status, and creatinine level at the time of transplant were. Survival outcomes were obtained using a Kaplan-Meier Curve. The impact of all variables on survival outcomes was calculated using a cox regression. Data were expressed as mean ± std (SAS Inc). Results Out of 1,294 patients, 43.6% were male, 76.7% were Caucasian, 9.4% were African American, and 9.0% were Hispanic. 1.2% had experienced a previous transplant and 41.2% had a prior graft. Height was 160.0 ± 23.3 cm, weight was 59.1 ± 20.1 kg, BMI was 22.2 ± 4.9, age was 34.5 ± 15.3 years, donor age was 25.8 ± 14.0 years, ischemic time was 3.7 ± 1.2 hours, creatine levels were 1.0 ± .6 mg/dL, and LOS was a median of 26 days. The Kaplan-Meier Survival Curve showed 1, 3, 5, and 10 year survival outcomes of 68.5%, 53.1%, 44.7%, and 29.8% respectively. The cox regression showed a significant change in survival outcome from the inclusion of all variables (p=0.000). Only the variables graft status (p=0.000), donor age (p=0.002), and LOS (p=0.003) were significant. A prior graft increased the hazard ratio to 1.846, while the hazard ratios for donor age and LOS were 1.015 and 1.003 respectively. Conclusion In selected patients, for the last resort of the patients with end-stage cardiopulmonary failure, combined heart and lung transplantation remains a viable option for excellent outcomes.
The future of newborn screening for lysosomal disorders.

Abstract The goal of newborn screening is to enhance the outcome of individuals with serious, treatable disorders through early, pre-symptomatic detection. The lysosomal storage disorders (LSDs) comprise a group of more than 50 diseases with a combined frequency of approximately 1:7000. With the availability of existing and new enzyme replacement therapies, small molecule treatments and gene therapies, there is increasing interest in screening newborns for LSDs with the goal of reducing disease-related morbidity and mortality through early detection. Novel screening methods are being developed, including efforts to enhance accuracy of screening using an array of multi-tiered, genomic, statistical, and bioinformatic approaches. While NBS data for Gaucher disease, Fabry disease, Krabbe disease, MPS I, and Pompe disease has demonstrated the feasibility of widespread screening, it has also highlighted some of the complexities of screening for LSDs. These include the identification of infants with later-onset, untreatable, and uncertain phenotypes, raising interesting ethical concerns that should be addressed as part of the NBS implementation process. Taken together, these efforts will provide critical, detailed data to help guide objective, ethically sensitive decision-making about NBS for LSDs.
Residual Stresses in Ceramics

The Materials Research Laboratory of The Pennsylvania State University has developed an advanced XRD stress measuring instrument which provides for unprecedented stress measurement speed consistent with excellent accuracy.
Restriction and Modification of Bacteriophage S2 in Haemophilus influenzae

The major conclusion from these studies is that variants of Haemophilus influenzae Rd which restrict and modify phage S2 are metastable and capable of giving rise to one another with high frequency. Nonrestrictive RdS cells segregate spontaneously to the restricting, modifying phenotype in about 5% of the progeny of a single clone. The restrictive cells derived from RdS revert to the nonrestrictive phenotype in 15 to 25% of the progeny of a single clone. These frequencies are not appreciably affected by treatment with acriflavine or ethidium bromide, compounds which affect plasmid stability, or by nitrosoguanidine, a powerful mutagen. The genetic locus for restriction and modification of bacteriophage S2 is found to have a chromosomal position between the biotin and proline loci. Restriction-modification of phage S2 has been shown to be a function of its deoxyribonucleic acid (DNA) in that transfection with S2 phage DNA or prophage DNA is subject to host restriction and modification. An enzyme preparation, which contains endodeoxyribonuclease but no appreciable exonuclease activity, from mutant H. influenzae com(-10) did not restrict phage S2.RdS DNA or prophage DNA transfecting activity, indicating that this endodeoxyribonuclease is not responsible for phage restriction. A new restriction enzyme isolated from H. influenzae Rd was found to be the major enzyme involved in the restriction of bacteriophage S2. The enzyme inactivated the transfecting activity of unmodified phage DNA but did not attack modified phage DNA. Unlike endodeoxyribonuclease R, this enzyme requires adenosine triphosphate and S-adenosylmethionine.
Our Interstellar Neighborhood

Far beyond the orbit of Pluto, the solar wind becomes too spread out to counter the interstellar medium, and the sphere of influence of our Sun ends in a termination shock, heliopause, and possibly a bow shock. In his Perspective, Jokipii discusses how the solar wind and the interstellar medium interact in this region. He highlights the report by Lallement et al, who show that the neutral hydrogen atoms in the interstellar plasma are deflected relative to the neutral helium and conclude that the only feasible explanation is a lateral asymmetry in the termination and bow shocks caused by the interstellar magnetic field. The results are the most direct data on the magnetic field in the local interstellar medium to date.
Comparison of the Tryptophan Synthetase α Subunits of Several Species of Enterobacteriaceae

Creighton, T. E. (Stanford University, Stanford), D. R. Helinski, R. L. Somerville, and C. Yanofsky. Comparison of the tryptophan synthetase alpha subunits of several species of Enterobacteriaceae. J. Bacteriol. 91:1819-1826. 1966.-The tryptophan synthetase alpha subunits of Escherichia coli K-12, E. coli B, Shigella dysenteriae, Salmonella typhimurium, and Aerobacter aerogenes have been purified and their structures compared. Each of these alpha subunits exhibits a sedimentation coefficient of about 2.7S. Peptide patterns of trypsin plus chymotrypsin digests of the alpha subunits have indicated that all of the alpha subunits have peptide regions in common. The patterns of E. coli K-12, E. coli B, and S. dysenteriae alpha subunits appear to be nearly identical, whereas the alpha subunits from S. typhimurium and A. aerogenes differ from those of E. coli and from each other. It has also been shown that the E. coli structural gene for the alpha subunit is translated identically in E. coli and S. typhimurium.
Optimal charging of plug-in hybrid electric vehicles in smart grids

Plug-in hybrid electric vehicles (PHEVs) play an important role in making a greener future. Given a group of PHEVs distributed across a power network equipped with the smart grid technology (e.g. wireless communication devices), the objective of this paper is to study how to schedule the charging of the PHEV batteries. To this end, we assume that each battery must be fully charged by a pre-specified time, and that the charging rate can be time-varying at discrete-time instants. The scheduling problem for the PHEV charging can be augmented into the optimal power flow (OPF) problem to obtain a joint OPF-charging (dynamic) optimization. A solution to this highly nonconvex problem optimizes the network performance by minimizing the generation and charging costs while satisfying the network, physical and inelastic-load constraints. A global optimum to the joint OPF-charging optimization can be found efficiently in polynomial time by solving its convex dual problem whenever the duality gap is zero for the joint OPF-charging problem. It is shown in a recent work that the duality gap is expected to be zero for the classical OPF problem. We build on this result and prove that the duality gap is zero for the joint OPF-charging optimization if it is zero for the classical OPF problem. The results of this work are applied to the IEEE 14 bus system.
A preliminary comparison of flat affect schizophrenics and brain-damaged patients on meausres of affective processing☆

Flat affect is a major component of schizophrenia and is often also seen in neurological disorders. A preliminary set of comparisons were conducted to delineate neuropsychological mechanisms underlying flat affect in schizophrenia, and new measures are described for the assessment of affective deficits in clinical populations. Subjects were schizophrenic with flat affect (SZs), right brain-damaged (RBD), Parkinson's Disease (PDs), and normal control (NC) right-handed adults. Subjects were administered affective measures of expression and perception in both facial and vocal channels. For both perceptual and expressive tasks the SZs performed significantly less accurately than the NCs and the PDs but did not differ from the RBDs. This was the case for both face and voice. This finding lends support to the speculation that right hemisphere mechanisms, especially cortical ones, may be compromised among schizophrenics with flat affect.
Simulation of interfacial dynamics of time-dependent converging flows in microchannels

With the growing interest and development of microfluidic systems, the need for micro-scale laminar flow mixing techniques is evident. Traditional mixing methods often rely upon turbulent flow for mixing which is generally not present on the micro-scale and so alternative approaches must be sought. In this work we investigate the potential for destabilizing the interface between converging flows using flow pulsation. A 3-D computational model of the converging flow at a 90 degrees junction is developed using the Fluent CFD software whereby the time-dependent behavior of the interface can be studied downstream of the junction. The interface is tracked using the Volume-of-Fluid method. Our results show the formation of a complex, evolving interfacial distortion which propagates and persists downstream of the junction; the degree of distortion observed suggests the possible onset of a hydrodynamic instability. The results also show that the complexity of the interfacial structure is only significant at higher frequencies (order of kHz) which is appropriate for MEMS pumping devices.© (2001) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Disposable electrodes for field screening of trace uranium

A novel electrochemical sensor for trace (μg/L) Uranium, based on adsorptive stripping potentiometry, is described. The sensor operation relies on the adsorptive accumulation of the uranium-cupferron complex onto a mercury-coated screen-printed carbon electrode. The disposable nature of these electrodes makes them very attractive for on-site characterization of nuclear energy sites. Various variables affecting the potentiometric stripping response were characterized and optimized to yield low-detection limit (e.g., 0.5 μg/L following a 5 minute adsorption) and good precision (relative standard deviation (RSD) = 1.4% for n = 15, 25 μg/L uranium). Convenient measurements can be carried out in nondeaerated and quiescent solutions. Applicability to the quantitation of uranium in groundwater samples is demonstrated.
A Note on the Diurnal Wind Variation

In recent correspondence HARRIS (1960) suggested that the discrepancy between observed winds and those computed from a theoretical model for the diurnal wind variation (HALTINER 1959) may be due, at least in part, to the diurnal pressure variation which had been omitted in the theoretical model. DOI: 10.1111/j.2153-3490.1961.tb00106.x
Time-resolved fluorescence and 1H NMR studies of tyrosyl residues in oxytocin and small peptides: correlation of NMR-determined conformations of tyrosyl residues and fluorescence decay kinetics

Steady-state and time-resolved fluorescence properties of the single tyrosyl residue in oxytocin and two oxytocin derivatives at pH 3 are presented. The decay kinetics of the tyrosyl residue are complex for each compound. By use of a linked-function analysis, the fluorescence kinetics can be explained by a ground-state rotamer model. The linked function assumes that the preexponential weighting factors (amplitudes) of the fluorescence decay constants have the same relative relationship as the 1H NMR determined phenol side-chain rotamer populations. According to this model, the static quenching of the oxytocin fluorescence can be attributed to an interaction between one specific rotamer population of the tyrosine ring and the internal disulfide bridge.
A new chemical probe for single-stranded RNA.

Abstract The reaction of cytidine with sodium bisulfite and methylamine gives transamination to N4-methylcytidine and deamination to uridine. At pH 7.4, however, transamination takes place exclusively. This reaction was applied to yeast RNA (7 days, 37°) and afforded the specific conversion of 54% of the cytidine residues to N4-methylcytidine residues. The same procedure converted up to 95% of the cytidines of polycytidylic acid to N4-methylcytidines. A complex of polycytidylic acid with polyinosinic acid was, however, totally resistant to the reaction. Because of its cytosine specificity, single-strand specificity, possibility of use of radioactive methylamine, mild conditions, and ease of analysis, this reaction seems ideally suited as a chemical probe for single-stranded regions in RNA.
Molecular distinction between arteries and veins

The vertebrate vascular system is essential for the delivery and exchange of gases, hormones, metabolic wastes and immunity factors. These essential functions are carried out in large part by two types of anatomically distinct blood vessels, namely arteries and veins. Previously, circulatory dynamics were thought to play a major role in establishing this dichotomy, but recently it has become clear that arterial and venous endothelial cells are molecularly distinct even before the output of the first embryonic heartbeat, thus revealing the existence of genetic programs coordinating arterial-venous differentiation. Here we review some of the molecular mechanisms involved in this process.
Phacoemulsification with topical anesthesia performed by resident surgeons.

Abstract Purpose: To evaluate and compare the outcomes in phacoemulsification cases performed by resident surgeons using topical anesthesia or retrobulbar anesthesia. Setting: Department of Ophthalmology, Emory University, Atlanta, and Department of Veterans Affairs Medical Center, Decatur, Georgia, USA. Methods: This was a retrospective review of phacoemulsification cases performed by resident surgeons during 1 academic year. Variables analyzed included patient age and sex, preexisting conditions limiting final acuity, and type of anesthesia used. Outcomes measured included intraoperative and postoperative complications and final visual acuity. Results: Of the 291 cases analyzed, 119 (40.9%) were retrobulbar and 172 (59.1%) were topical. Residents began using topical anesthesia after a brief introductory period with retrobulbar anesthesia. Vitreous loss occurred in 15 cases (5.1%), 8 retrobulbar (6.7%) and 7 topical (4.1%) ( P = .42). Postoperative complications occurred in 30 cases (10.3%), 17 topical (9.9%) and 13 retrobulbar (10.9%) ( P = .85). Overall, 245 cases (84.2%) achieved a final best corrected visual acuity (BCVA) of 20/40 or better. When cases with preexisting conditions limiting final acuity were eliminated, 92.1% achieved a final BCVA of 20/40 or better. More topical cases (112, 65.1%) than retrobulbar cases (64, 53.8%) achieved a final BCVA of 20/25 or better ( P = .06), and more topical cases (149, 86.6%) than retrobulbar cases (96, 80.7%) achieved a final BCVA of 20/40 or better ( P = .19). Conclusion: Topical anesthesia is safe and efficacious for phacoemulsification performed by resident surgeons early in training after a brief introduction to phacoemulsification using retrobulbar anesthesia.
The psaA operon pre-mRNA of the Euglena gracilis chloroplast is processed into photosystem I and II mRNAs that accumulate differentially depending on the conditions of cell growth

The chloroplast genome of Euglena gracilis contains a psaA operon which encodes a lysine tRNA gene, trnK; psaA and psaB photosystem I genes, and psbE, psbF, psbL and psbJ photosystem II genes. The pre-mRNA of the psaA operon undergoes a complex processing pathway of 5' and 3' tRNA processing, splicing of 11 group II introns and one group II twintron, plus three intercistronic RNA cleavage events. The accumulated transcripts of the psaA operon have been characterized by Northern hybridization, S1 nuclease analysis and primer extension RNA sequencing. The mature 5' end of the psaA-psaB-psbE-psbF-psbL-psbJ hexacistronic transcript lies 8 nt downstream of the trnK gene, and is the result of intercistronic trnK-psaA cleavage. Other intercistronic processing events occur between the psaA and psaB genes and the psaB and psbE genes. Processing at the latter site produces a dicistronic mRNA of PSI genes and a tetracistronic mRNA of PSII genes. The PSI dicistronic transcript is further processed to monocistronic psaA and psaB mRNAs. Secondary structural motifs within the intercistronic regions may be recognition sites for processing. The steady-state levels of psaA operon mRNAs from Euglena grown under several different conditions have been determined. Accumulated transcripts from all growth conditions are spliced, and a proportion are also processed at the intercistronic sites. The products of intercistronic processing increase from heterotrophic dark- to heterotrophic light-grown Euglena, and from heterotrophic light- to photoautotrophic light-grown Euglena. The differential accumulation of psaA operon mRNAs may be a means of chloroplast gene regulation or, alternatively, a consequence of gene expression during chloroplast development.
Building cooperative advantage: Managing strategic alliances to promote organizational learning

Abstract This study focuses on the relationship between strategic alliances and organizational learning. Building cooperative advantage requires partners to realize that the dynamics of collaboration and learning are likely to evolve over distinct stages of alliance evolution. Although alliance relationships will require different sets of managerial skills and behaviors across these evolutionary stages, there are several factors that markedly shape the firm 's ability to learn over time. These include the nature of the shared business activity, the type of knowledge that is jointly developed, and the firm's reward system.
Analysis of the B-G antigens of the chicken MHC by two-dimensional gel electrophoresis.

The B-G antigens of the chicken major histocompatibility complex (MHC) have been analyzed by high resolution two-dimensional (2-D) gel electrophoresis. Monoclonal antibodies recognizing a widely shared B-G determinant were used for immunoprecipitating the B-G antigens from radioiodinated, detergent-solubilized erythrocyte membrane preparations. The B-G antigens produce a variety of patterns on 2-D gels. The number of polypeptides within a B-G pattern varies among haplotypes from single polypeptide arrays showing slight microheterogeneity to complex patterns which contain as many as four or five polypeptide arrays differing in relative mobility and isoelectric point. Many of the patterns, but not all, include a polypeptide of Mr =48 kd focusing near pH 6.9. At present it is not understood whether the multiple polypeptides within some B-G patterns represent the expression of multiple B-G genes or whether they are the result of modifications of single gene products during biosynthetic processing. 2-D gel analyses were also used to confirm the assignment of the same B-G haplotype in several different inbred flocks and the fate of the B-G antigens in two B system recombinant haplotypes. The 2-D gel patterns of these highly polymorphic antigens provide evidence for a complexity of the B-G locus not previously demonstrated. This technique may serve to define more objectively the diverse chicken MHC haplotypes which are now recognized and characterized only by serological techniques using alloantisera and monoclonal antibodies with varying cross-reactivities.
Initial Evaluation of Vascular Ingrowth into Superporous Hydrogels

There is a need for new materials and architectures for tissue engineering and regenerative medicine. Based upon our recent results developing novel scaffold architecture, we hypothesized that this new architecture would foster vascularization, a particular need for tissue engineering. We report on the potential of superporous hydrogel (SPH) scaffolds for in vivo cellular infiltration and vascularization. Poly(ethylene glycol) diacrylate (PEGDA) SPH scaffolds were implanted in the dorsum of severe combined immunodeficient (SCID) mice and harvested after 4 weeks of in vivo implantation. The SPHs were visibly red and vascularized, as apparent when compared to the non-porous hydrogel controls, which were macroscopically avascular. Host cell infiltration was observed throughout the SPHs. Blood cells and vascular structures, confirmed through staining for CD34 and smooth muscle α-actin, were observed throughout the scaffolds. This novel soft material may be utilized for cell transplantation, tissue engineering and in combination with cell therapies. The neovasularization and limited fibrotic response suggest that the architecture may be conducive to cell survival and rapid vessel development. Copyright © 2009 John Wiley & Sons, Ltd.
Reply to McCaffrey

We thank Dr McCaffrey for his thoughtful letter and for giving us the opportunity to address his concerns. Dr McCaffrey raises two important issues: first, he suggests that, under our definition of ‘lethal’ congenital anomaly, neonates with Trisomy 13 and 18 should not have been included in our cohort. He points to two recent case series where 25 to 44% of infants with Trisomy 13 and 18 survived for more than a year when treated aggressively, far above the 15% cutoff we employed in our definition. However, one of those series included only nine patients,1 and the other consisted of neonates referred to a tertiary center for ongoing care after birth, indicating that their population was enriched for neonates who survived long enough to transfer.2 Without data on the intensity of medical treatment and survival of the neonates who were not transferred, the unusually high survival rate at 1 year was likely due to selection bias rather than contemporary medical intervention. Further population-based studies examining the relation between treatment intensity and survival of infants with Trisomy 13 and 18 are needed.
Effects of TSH on the chemical composition of orbital tissue in guinea pigs.

Female guinea pigs were injected either with saline, with thyroxine, or with varying doses of TSH. Following a single ip injection of Na2 (35S)O4, the content of 35S was determined for the Harderian gland, ventral lacrimal gland, and serum. Specific glycosaminoglycan fractions were isolated from the Harderian gland using successive columns of cetylpyridinium chloride-cellulose and ECTEOLA, and were assayed for levels of hexosamine and of 35S. The following results were obtained: (1) TSH increased the 35S content of the serum, the Harderian gland, and the ventral lacrimal gland, while T4 had no effect; (2) TSH increased the proportion of total tissue 35S in chondroitin sulfate and decreased it in keratan sulfate; (3) the hexosamine content of the Harderian gland was increased by TSH, but not by T4; (4) TSH increased hexosamine levels in the hyaluronic acid, chondroitin sulfate, and glycoprotein fractions of the Harderian gland, and decreased them in the keratan sulfate fraction. We conclude that in experim...
Strength after bouts of eccentric or concentric actions.

This study examined the influence of an initial bout of eccentric or concentric actions and a subsequent bout of eccentric actions on muscular strength. Twenty-four healthy males, 24-45 yr old, were placed in three groups that performed eccentric actions in bouts 1 and 2 (ECC/ECC, N = 8), concentric actions in bout 1, and eccentric actions in bout 2 (CON/ECC, N = 8) or served as controls (N = 8). Bouts involved unilateral actions with the left and right quadriceps femoris. Ten sets of 10 repetitions with an initial resistance equal to 85% of the eccentric or concentric one repetition maximum (1 RM) were performed for each bout. Three minutes of rest were given between sets and 3 wk between bouts. Two weeks before bout 1 and 1, 4, 7, and 10 d after bouts 1 and 2, eccentric and concentric 1 RM were measured for the right quadriceps femoris and a speed-torque relation established for the left quadriceps femoris. Eccentric and concentric 1 RM decreased (P less than 0.05) 32% 1 d after bout 1 for group ECC/ECC. The speed-torque relation was down-shifted (P less than 0.05) 38%. Eccentric 1 RM and eccentric and isometric torque returned to normal 6 d later. Concentric 1 RM and torque at 3.14 rad-s(exp -1) had not recovered on day 10 (-7% for both, P less than 0.05). Decreases in strength after bout 2 for group ECC/ECC only occurred on day 1 (-9% for concentric 1 RM and 16% downshift of the speed- torque relation). Group CONIECC showed the opposite responses; marked decreases in strength after bout 2 but not bout 1. The results indicate that the initial decrease in strength after performance of a novel bout of eccentric exercise is comparable for eccentric, concentric and isometric muscle actions. Recovery of strength, however, appears to occur more rapidly for eccentric and isometric actions. They suggest that performance of a prior bout of eccentric but not concentric actions, as done in this study, can essentially eradicate decreases in strength after a subsequent bout of eccentric exercise. It is suggested that neural factors are, in part, responsible for adaptations to eccentric exercise.
Evidence from the Lamarck Granodiorite for Rapid Late Cretaceous Crust Formation in California

Strontium and neodymium isotopic data for rocks from the voluminous 90-million-year-old Lamarck intrusive suite in the Sierra Nevada batholith, California, show little variation across a compositional range from gabbro to granite. Data for three different gabbro intrusions within the suite are identical within analytical error and are consistent with derivation from an enriched mantle source. Recognition of local involvement of enriched mantle during generation of the Sierran batholith modifies estimates of crustal growth rates in the United States. These data indicate that parts of the Sierra Nevada batholith may consist almost entirely of juvenile crust added during Cretaceous magmatism.
A cationic electron spin resonance probe used to analyze cation interactions with lipopolysaccharide

Abstract The partitioning of a cationic electron spin resonance probe, 4-(dodecyl dimethyl ammonium)-1-oxyl-2,2,6,6,-tetramethyl piperidine bromide, into lipopolysaccharide from Escherichia coli W1485 was shown to increase markedly above approximately 15°C, presumably reflecting a thermal transition. Partitioning was also highly dependent on probe and lipopolysaccharide concentrations, and Scatchard analysis of electrodialyzed lipopolysaccharide revealed a single non-interactive binding site for the probe. Several cations were able to displace probe bound to this site. At concentrations above 30 μM, Ca2+ and Mg2+ displaced probe bound to electrodialyzed lipopolysaccharide while various polyamines and other cations were less effective. Since this probe is very sensitive to the environment of the lipopolysaccharide, it should prove to be a valuable tool in analyzing lipopolysaccharide structure and interactions with other molecules.
Conversion of radiolabeled human growth hormone into higher molecular weight moieties in human plasma in vivo and in vitro.

Purified human growth hormone (hGH) was iodinated with 131I ([131I]iodo-hGH) and purified on Sephadex G-100. The monomeric [131I]iodo-hGH (mol wt about 20,000 daltons) was injected as a bolus iv in healthy volunteers and plasma obtained at 10,20, and 40 min. Then continuous infusion with [13II]- iodo-hGH was started and further plasma samples obtained after 120 min when a plateau of immunoreactive hGH (IR-hGH) had been attained. In one individual the bolus injection was followed further to 60 and 120 min. Fresh plasma was immediately chromatographed on Sephadex G-100 and the IR-hGH profiles evaluated. In all instances following iv injection, larger and occasionally smaller immunoreactive moieties than the injected [131I]iodo-hGH appeared. When [131I]iodo-hGH was incubated at 37 C with fresh human plasma from 4 different individuals from 10 to 120 min, the larger molecular weight forms, noted in the in vivo studies, were again demonstrable. Only the monomeric [13lI]iodo-hGH was found when [131I]iodo-hGH wa...
Employee benefit programs and attitudinal and behavioral outcomes: A preliminary model

Abstract Despite recent attention to employee benefits by organizations, practitioners, and even politicians, human resource scholars and Industrial/Organizational psychologists have devoted little energy to this topic. A preliminary model of employee benefits and their effect on various attitudinal and behavioral outcomes is described. Several measurement issues, such as the definition of benefits, are addressed, along with theoretical explanations for the various linkages in the model. Greater use of qualitative methods, as well as examination of moderators, such as employee age, is encouraged.