cssi/SciSciGPT-SciSciNet huggingface dataset:
COPI gets a fancy new coat

A defining characteristic of eukaryotic cells is their numerous membrane-bound compartments, including the endoplasmic reticulum (ER), Golgi apparatus, and other organelles. Proteins and lipids are transported between these compartments and the cell surface by vesicles about 100 nm in diameter. Three canonical protein coat complexes facilitate the formation of these small vesicular carriers: the clathrin coat, coat protein 1 (COPI), and coat protein 2 (COPII) complexes. The COPII coat mediates vesicle formation at the ER for transport to the Golgi; the COPI coat forms vesicles at the cis-Golgi for transport to the ER; and clathrin has a dual role, forming vesicles at the trans-Golgi for transport to the plasma membrane and forming vesicles at the plasma membrane for endocytosis. Each of these coat complexes is composed of numerous proteins that bind to membrane, recognize cargo proteins, bend the parent membranes into a bud, and pinch the buds off into vesicles ( 1 ). On page 195 of this issue, Dodonova et al. ( 2 ) have created an atomic model of the COPI coat by using cryogenic electron tomography (cryo-ET) combined with labeling and cross-linking mass spectrometry. Their model gives new insights into the mechanisms by which the COPI proteins assemble into highly interconnected scaffoldings and work together to bend membrane.
Nematic liquid crystals on spherical surfaces: Control of defect configurations by temperature, density, and rod shape

Recent experiments have shown that defect conformations in spherical nematic liquid crystals can be controlled through variations of temperature, shell thickness, and other environmental parameters. These modifications can be understood as a result of the induced changes in the effective elastic constants of the system. To characterize the relation between defect conformations and elastic anisotropy, we carry out Monte Carlo simulations of a nematic on a spherical surface. As the anisotropy is increased, the defects flow from a tetrahedral arrangement to two coalescing pairs and then to a great circle configuration. We also analyze this flow using a variational method based on harmonic configurations.
Effects of C-methylated carnitine analogs on rates of mitochondrial fatty acid oxidation

Carnitine analogs containing one and/or two methyl substituents on the alpha-, beta-, or gamma-carbon were evaluated in isolated rat liver mitochondria for their effects on fatty acid oxidation. Their abilities to either support, in the absence of carnitine, or inhibit, in the presence of carnitine, carnitine-dependent fatty acid oxidation were determined by the conversion of radiolabeled [1-14C]palmitic acid to acid-soluble radiolabeled products. None of the methylcarnitine analogs were observed to be significant inhibitors of palmitate oxidation at concentrations (1.0 mM) up to ten times that for L-carnitine. The two diastereomers of D,L-4-methylcarnitine, however, were able to support palmitate oxidation in the absence of carnitine, and rates were roughly 40% of that obtained with equimolar (0.1 mM) L-carnitine.
Coupled antenna arrays with enhanced angular resolutions

Summary form only given. Biologically-inspired antenna arrays that mimic the hyperacute hearing characteristics of the parasitoid fly Ormia Ochracea have been recently reported. These biomimetic antenna arrays (BMAAs) consist of a two-element antenna array with closely spaced elements along with an external, passive coupling network (Behdad, et al., IEEE Antennas Wireless Propagat. Lett., 10, 361-364, 2011). It has been demonstrated that such BMAAs can achieve directional sensitivities significantly larger than those of regular antenna arrays with the same aperture dimensions. Therefore, these antenna arrays are expected to find applications in areas such as compact direction finding systems and high-resolution, small-aperture radar systems. While passive BMAAs demonstrate higher angular resolutions compared to conventional arrays of the same size, this added capability comes at the expense of sacrificing the output power of the antenna. This means that the better angular resolution of these arrays comes at the expense of limiting the range over which acceptable received signal-to-noise ratios (SNRs) can be achieved. In this work, a new coupled antenna array topology is presented, which addresses the shortcomings of the biologically-inspired antenna arrays reported previously. In particular, the new coupled antenna arrays proposed in this paper offer similar angular resolutions that can be achieved from two-element BMAAs. However, unlike previously reported BMAAs, they do not sacrifice the output power level to achieve this angular resolution. In this presentation, we examine a coupled antenna array composed of two receiving elements with a strong mutual coupling between the two elements. We then derive a theoretical bound for the maximum angular resolution that can be achieved from these arrays without paying a penalty in terms of the output power level. This analysis is then applied to a two-element antenna array operating at 600 MHz composed of two 13.5 cm monopole antennas separated by a distance of 2.5 cm. We demonstrate that for this antenna, the maximum achievable angular resolution that can be achieved without sacrificing the output SNR is roughly four times that of a regular array composed of the same elements with the same element spacing. Thus, the new coupled antenna arrays are able to obtain enhanced angular resolutions without sacrificing the output SNR. Details of the design process and experimental measurement results of the proposed antenna will be presented and discussed at the symposium.
Anesthesia for the surgical treatment of cerebral aneurysms

Although most cerebral aneurysms are asymptomatic and discovered incidentally, their rupture often results in significant morbidity and mortality. The anesthesiologist may become involved in surgical clipping of aneurysms either before aneurysm rupture or after subarachnoid hemorrhage. After subarachnoid hemorrhage, a multisystemic preoperative evaluation is mandatory because both neurological complications (elevated intracranial pressure, rebleeding, hydrocephalus, vasospasm) and non-neurological complications (respiratory insufficiency, cardiac dysfunction, electrolyte abnormalities, endocrine disturbances) might influence anesthetic management. Besides being prepared for potential sudden profuse bleeding, the anesthesiologist caring for craniotomy for aneurysm clipping should follow four main principles. First, acute increase in the aneurysm transmural gradient (mean arterial pressure minus intracranial pressure) should be avoided to prevent rupture or rebleeding. Second, the cerebral perfusion pressure should be maintained with euvolemia and vasopressors to avoid brain ischemia caused either by brain retractors or temporary clipping of the feeding vessel. Third, surgical exposure should be optimized by providing brain relaxation with normal cerebral oxygenation, normal ventilation or transient hyperventilation, appropriate anesthetic choice, mannitol and perhaps lasix, and occasionally cerebrospinal fluid drainage. Fourth, early emergence is favored to allow recognition of potentially reversible complications. By being vigilant and achieving these goals, the anesthesiologist will contribute to optimal patient outcomes. The following article provides information to guide the anesthesiologist in optimal management of surgical clipping of aneurysms.
Causal Inference in Environmental Impact Studies

Justification of a cause-and-effect relationship in environmental impact studies is com- plicated by inherent qualities of impact data. Lack of randomization and replication invalidate the use of inferential statistics for inferring a causal link, and place special demands on descriptive arguments for causation. Assembly rules for causal arguments have been developed in epidemiology and provide a rigorous structure for descriptive analysis. Explicit use of assembly rules for making causal arguments allows investigators to efficiently organize, study, and present available evidence. Within this framework, statistical tests can be used to determine if populations at study sites were different after the impact, but the establishment of a causal link between the impact and the observed difference is based on an argument. Causal inference by means of argument is consistent with the scientific method of strong inference and increases the likelihood of correct conclusions.
Inhibition of histone deacetylase 3 protects beta cells from cytokine-induced apoptosis

Cytokine-induced beta-cell apoptosis is important to the etiology of type-1 diabetes. Although previous reports have shown that general inhibitors of histone deacetylase (HDAC) activity, such as suberoylanilide hydroxamic acid and trichostatin A, can partially prevent beta-cell death, they do not fully restore beta-cell function. To understand HDAC isoform selectivity in beta cells, we measured the cellular effects of 11 structurally diverse HDAC inhibitors on cytokine-induced apoptosis in the rat INS-1E cell line. All 11 compounds restored ATP levels and reduced nitrite secretion. However, caspase-3 activity was reduced only by MS-275 and CI-994, both of which target HDAC1, 2, and 3. Importantly, both MS-275 and genetic knockdown of Hdac3 alone were sufficient to restore glucose-stimulated insulin secretion in the presence of cytokines. These results suggest that HDAC3-selective inhibitors may be effective in preventing cytokine-induced beta-cell apoptosis.
Vasomotor Rhinitis Is Not a Wastebasket Diagnosis

The impact of chronic rhinitis on patients, health care systems, and resources is substantial, resulting in more than 25 million office visits per year and resulting in total indirect and direct costs of $6 billion annually. It is estimated that more than 10% of the population has chronic or recurrent nasal obstruction or congestion, rhinorrhea, sneezing, and pruritus. Approximately half of these patients are classified as having allergic rhinitis and half as having nonallergic rhinitis, including vasomotor rhinitis. These forms of chronic, noninfectious rhinitis represent a spectrum of nasal disorders that are best categorized as a hyperreactivity of the nasal mucosa to a variety of stimuli. Allergic rhinitis is diagnosed when specific antigens can be identified and is often subclassified as seasonal or perennial allergic rhinitis. When specific antigens are not identifiable, chronic rhinitis is often classified as vasomotor or nonallergic. These nonallergic forms of chronic rhinitis can be further evaluated by nasal cytology. Nasal scrapings of the inferior turbinate can yield epithelial lining, and detailed analysis of different cell types can be made. Patients with nonallergic rhinitis and abundant eosinophils on nasal cytology have the so-called nonallergic rhinitis with eosinophilia syndrome, which is sometimes associated with aspirin intolerance. Patients with nonallergic rhinitis and unremarkable nasal smear findings could have rhinitis medicamentosa, pregnancy, or hypothyroidism, but most are thought to have vasomotor rhinitis. Most of the literature concerning vasomotor rhinitis and its relationship to the autonomic nervous system came from investigations 50 years ago. These authors discuss the role of the autonomic nervous system in maintaining sinonasal health through the regulation of vascularity and mucosal gland function, and they speculate that the autonomic nervous system regulates the reactivity of the nasal and sinus mucous membranes and glands. They note that the inferior turbinate in particular contains mucous and serous glands, vascular channels, and autonomic nervous system branches that constitute a delicately sensitive and reactive organ. Vasomotor rhinitis was thought to represent either hyperfunction of the parasympathetic nervous system in the nose and paranasal sinuses or an imbalance between the parasympathetic nervous system and sympathetic nervous system. Does vasomotor rhinitis exist, and if so, what is its etiology? Is it a specific entity and part of a continuum of disease or is it a “wastebasket” diagnosis? This article hypothesizes the former.
Sensitivity in Synthetic Aperture Ladar Imaging

Synthetic Aperture Ladar (SAL) imaging experiments show that cross-range compression, including image based phase error correction, can be performed at very low return light levels. This includes images where the precompression shot-noise-limited signal-to-noise ratio is much less than unity.
Evaluation of problem solving and communication skills of persons with schizophrenia

Although much research has shown positive outcomes of teaching problem solving and communication skills to persons with schizophrenia, the amount of research on the assessment of these two sets of skills has been modest. The current study demonstrates an effective model for their assessment and includes a previously neglected procedure to determine if subjects attended to the skill prompts. It replicates and expands prior findings on problem solving and communication skills. Results indicated that persons with schizophrenia were generally deficit in problem solving skills. Persons without schizophrenia seemed to use more behavioral information when deciding if a problem existed and they were better able to differentiate between appropriate and inappropriate solutions to problems. Persons with schizophrenia were found to be deficit in communication skills that facilitate interaction and showed a style that subordinated their wants to those of others.
Reducing instruction cache energy consumption using a compiler-based strategy

Excessive power consumption is widely considered as a major impediment to designing future microprocessors. With the continued scaling down of threshold voltages, the power consumed due to leaky memory cells in on-chip caches will constitute a significant portion of the processor's power budget. This work focuses on reducing the leakage energy consumed in the instruction cache using a compiler-directed approach.We present and analyze two compiler-based strategies termed as conservative and optimistic. The conservative approach does not put a cache line into a low leakage mode until it is certain that the current instruction in it is dead. On the other hand, the optimistic approach places a cache line in low leakage mode if it detects that the next access to the instruction will occur only after a long gap. We evaluate different optimization alternatives by combining the compiler strategies with state-preserving and state-destroying leakage control mechanisms. We also evaluate the sensitivity of these optimizations to different high-level compiler transformations, energy parameters, and soft errors.
Short-range order and melting anomalies in thin films

Recent experiments show that high-coverage4He monolayers adsorbed on graphite have low-temperature heat capacities corresponding to two-dimensional solids. At higher temperatures the solid phase appears to “melt” by a continuous process, suggesting a connection with the theoretical prediction that there can be no long-range crystalline order at finiteT in two-dimensional systems governed by typical interatomic forces. This paper explores the theory in greater detail, with attention to long-range and short-range order and their experimental implications. Several models are studied: two-dimensional harmonic solids with “Debye” phonon spectra, lattices with Van Hove singularities, two-dimensional quantum solids, and effects of periodic potentials due to substrate structure. The theory is discussed in the light of current understanding of melting, and the following new melting hypothesis is proposed. Applied to two-dimensional systems, the hypothesis predicts a continuous transition with a heat-capacity contribution similar in its temperature dependence to the anomalies seen in4He monolayers and N2 multilayers. Applied to three-dimensional Debye solids, the same hypothesis predicts an abrupt first-order process, with a melting temperature obeying the Lindemann law.
Restricted variational principle method for the free-molecular mixing of parallel streams

Rosen's restricted variational principle representation of the Boltzmann equation is used to determine the free-molecular mixing of two initially parallel streams of differing temperature and speed ratio. Mixing is accomplished by means of thermal and convective motions of the gas particles. It is shown that the variational method leads to a rapid calculation scheme for number density and velocity; the results of the method compare closely to the exact special function solutions of the collisionless Boltzmann equation.
X-RAY EMISSIONS FROM COLLISIONS OF O6+ IONS WITH CO

Laboratory measurements of soft X-ray emissions from collisions between 36 keV O{sup 6+} ions and CO have been carried out with the aim of simulating emissions from comets interacting with the solar wind. Spectra in the range 62-155 eV are recorded and compared to results of the over-barrier model (OBM) and multichannel Landau-Zener (MLZ) calculations. Emissions from n = 3, 4 states of O{sup 5+} are observed. This is in good agreement with the OBM predictions of highest n-state for the electron capture. Line intensities for the n = 4 capture in simulated spectra using the semi-empirical MLZ approach, taking into account multielectron captures, are in very good agreement with experimental measurements. However, the OBM does not correctly account for direct feeding of the n = 3 levels for the CO target, though it does explain predominance of the n = 3 levels for an He target.
Assessing the effect of failure severity, coincident failures and usage-profiles on the reliability of embedded control systems

The increasingly ubiquitous use of embedded systems to manage and control our technologically (ever-increasing) complex lives makes us more vulnerable than ever before. Knowing how reliable such systems are is absolutely necessary especially for safety, mission and infrastructure critical applications. This paper presents a structured compositional modeling method for assessing reliability based on characteristic data and stochastic models. We illustrate this using a classic embedded control system (sensor-inputs | processing | actuator-outputs), Anti-lock Braking System (ABS) and empirical data. Special emphasis is laid on modeling extra-functional characteristics of severity of failures, coincident failures and usage-profiles with the goal of developing a modeling strategy that is realistic, generic and extensible. The validation approach compares the results from the two separate models. The results are comparable and indicate the effect of coincident failures, failure severity and usage-profiles is predictable.
The role of dissipation in a truncation of Hénon's map

Abstract The behavior of a truncation of Henon's map is studied as the dissipation is varied from zero to finite values. The map exhibits a continuous transition from stochasticity in the measure preserving case to the dissipative regime.
Cryptic Moths: Effects on Background Selections of Painting the Circumocular Scales

A dark moth (Catocala antinympha) and a light moth (Campaea perlata) rested on appropriate backgrounds in an experimental apparatus allowing a choice between black and white backgrounds. The selections remained unchanged when the circumocular scales of the moths were painted either black or white. These results suggest that selections of background by cryptic moths, with respect to background reflectance, are genetically fixed. Background selections by melanic forms in various species are interpreted in the light of this conclusion.
Analysis of the contact graph routing algorithm: Bounding interplanetary paths

Abstract Interplanetary communication networks comprise orbiters, deep-space relays, and stations on planetary surfaces. These networks must overcome node mobility, constrained resources, and significant propagation delays. Opportunities for wireless contact rely on calculating transmit and receive opportunities, but the Euclidean-distance diameter of these networks (measured in light-seconds and light-minutes) precludes node discovery and contact negotiation. Propagation delay may be larger than the line-of-sight contact between nodes. For example, Mars and Earth orbiters may be separated by up to 20.8 min of signal propagation time. Such spacecraft may never share line-of-sight, but may uni-directionally communicate if one orbiter knows the other's future position. The Contact Graph Routing (CGR) approach is a family of algorithms presented to solve the messaging problem of interplanetary communications. These algorithms exploit networks where nodes exhibit deterministic mobility. For CGR, mobility and bandwidth information is pre-configured throughout the network allowing nodes to construct transmit opportunities. Once constructed, routing algorithms operate on this contact graph to build an efficient path through the network. The interpretation of the contact graph, and the construction of a bounded approximate path, is critically important for adoption in operational systems. Brute force approaches, while effective in small networks, are computationally expensive and will not scale. Methods of inferring cycles or other librations within the graph are difficult to detect and will guide the practical implementation of any routing algorithm. This paper presents a mathematical analysis of a multi-destination contact graph algorithm (MD-CGR), demonstrates that it is NP-complete, and proposes realistic constraints that make the problem solvable in polynomial time, as is the case with the originally proposed CGR algorithm. An analysis of path construction to complement hop-by-hop forwarding is presented as the CGR-EB algorithm. Future work is proposed to handle the presence of dynamic changes to the network, as produced by congestion, link disruption, and errors in the contact graph. We conclude that pre-computation, and thus CGR style algorithms, is the only efficient method of routing in a multi-node, multi-path interplanetary network and that algorithmic analysis is the key to its implementation in operational systems.
The case of the missing CVs: Multi-joint primitives

The search for simplifying principles in motor control motivates the target article. One method that the CNS uses to simplify the task of controlling a limb's mechanical properties is absent from the article. Evidence from multi-joint, force-field measurements and from kinematics that points to the existence of multi-joint primitives as control variables is discussed.
Universals and particulars in telephone openings

(1990). Universals and particulars in telephone openings. Research on Language and Social Interaction: Vol. 24, No. 1-4, pp. 369-387.
Voluntary progression order in captive rhesus macaques

The sequence in which 14 laboratory rhesus macaques left their home enclosure during a routine catching procedure was recorded on 30 occasions during 6 weeks. The animals were trained to voluntarily exit one by one and enter a transport cage for weighing and/or treatment. Mean weekly exit orders cross-correlated significantly, and individuals retained their exit positions with remarkable consistency throughout the study period. An animal's position did not depend on its sex, age, or dominance rank. The oldest female never failed to enter the transport cage as number 1. When she was prevented from taking the lead, the group was hesitant but eventually proceeded in the usual order. Food was a strong, yet not absolute, incentive for the monkeys to cooperate. If they could not expect a reward, they took more time before proceeding, but did so in the habitual order. The predictability of the exit sequence has practical managerial value because it makes it possible for a single person to quickly catch a selected group member when necessary.
Hypertension in the United States, 1999 to 2012 Progress Toward Healthy People 2020 Goals

Background—To reduce the cardiovascular disease burden, Healthy People 2020 established US hypertension goals for adults to (1) decrease the prevalence to 26.9% and (2) raise treatment to 69.5% and control to 61.2%, which requires controlling 88.1% on treatment. Methods and Results—To assess the current status and progress toward these Healthy People 2020 goals, time trends in National Health and Nutrition Examination Surveys 1999 to 2012 data in 2-year blocks were assessed in adults ≥18 years of age age-adjusted to US 2010. From 1999 to 2000 to 2011 to 2012, prevalent hypertension was unchanged (30.1% versus 30.8%, P=0.32). Hypertension treatment (59.8% versus 74.7%, P<0.001) and proportion of treated adults controlled (53.3%–68.9%, P=0.0015) increased. Hypertension control to <140/<90 mm Hg rose every 2 years from 1999 to 2000 to 2009 to 2010 (32.2% versus 53.8%, P<0.001) before declining to 51.2% in 2011 to 2012. Modifiable factor(s) significant in multivariable logistic regression modeling include: (1...
Reducibility and thermal scaling of charge distributions in multifragmentation.

A strong thermal signature is found in the charge distributions associated with multifragmentation from the reaction ${}^{36}\mathrm{Ar}{+}^{197}\mathrm{Au}$ at $E/A\phantom{\rule{0ex}{0ex}}=\phantom{\rule{0ex}{0ex}}110$ MeV. The $n$-fold charge distributions are reducible to the onefold charge distributions through a simple scaling that is dictated by fold number and charge conservation.
Development of a fast temperature sensor for combustion gases using a single tunable diode laser

The 12 best NIR water transition line pairs for temperature measurements with a single DFB laser in flames are determined by systematic analysis of the HITRAN simulation of the water spectra in the 1–2 μm spectral region. A specific line pair near 1.4 μm was targeted for non-intrusive measurements of gas temperature in combustion systems using a scanned-wavelength technique with wavelength modulation and 2f detection. This sensor uses a single diode laser (distributed-feedback), operating near 1.4 μm and is wavelength scanned over a pair of H2O absorption transitions (7154.354 cm-1 & 7153.748 cm-1) at a 2 kHz repetition rate. The wavelength is modulated (f=500 kHz) with modulation amplitude a=0.056 cm-1. Gas temperature is inferred from the ratio of the second harmonic signals of the two selected H2O transitions. The fiber-coupled-single-laser design makes the system compact, rugged, low cost and simple to assemble. As part of the sensor development effort, design rules were applied to optimize the line selection, and fundamental spectroscopic parameters of the selected transitions were determined via laboratory measurements including the temperature-dependent line strength, self-broadening coefficients, and air-broadening coefficients. The new sensor design includes considerations of hardware and software to enable fast data acquisition and analysis; a temperature readout rate of 2 kHz was demonstrated for measurements in a laboratory flame at atmospheric pressure. The combination of scanned-wavelength and wavelength-modulation minimizes interference from emission and beam steering, resulting in a robust temperature sensor that is promising for combustion control applications.
Association between school engagement and disclosure of suicidal ideation to adults among Latino adolescents.

We examined associations between Latino adolescents’ school engagement and their likelihood of disclosing suicidal ideation (SI) to adults and of asking for help for SI. A first set of analyses was conducted on a total sample of 14 high schools, and a second set of analyses was conducted on 8 “Latino-representative” high schools. The criterion for Latino representation was that ≥10 % of the school’s total student population was Latino. Across all 14 high schools, 17 % (110/663) of Latino students reported SI in the past year, compared to 13 % (359/2,740) of non-Hispanic White students and 11 % (78/719) of African American students. Of Latino students with SI, 24 % (26/110) told an adult and 35 % (38/110) sought help. In the 8 Latino-representative schools, higher levels of reported school engagement were associated with a greater likelihood of seeking help (OR = 6.17) and disclosure of SI to an adult (OR = 7.64) for Latino males. For Latinas, however, school engagement was not associated with either disclosure of SI to an adult or seeking help. Additional research is needed to clarify the processes, including social connectedness, that contribute to the disclosure of and help-seeking for SI among Latino adolescents.
Photoconductive ZnO films with embedded quantum dot or ruthenium dye sensitizers

We report a new type of solution-processed photoconductive film based on embedding photosensitizers (semiconductor nanocrystals or ruthenium dye molecules) within conductive ZnO sol-gel matrices. Mixing photosensitizers directly with sol-gel precursors prior to film deposition yields highly colored ZnO films containing well-dispersed sensitizers. These films show internal photoconductivity quantum efficiencies up to ∼50% and photoresponses over 100 mA/W with visible photoexcitation, competitive with other more complex photodetectors reported recently. This simple motif is attractive for the development of robust sensitized-oxide photodetectors and for fundamental studies of photoinduced charge separation from a variety of molecular or quantum dot sensitizers into conductive oxides.
N-terminal Amino Acid Residues Mediate Protein-Protein Interactions between DNA-bound α/β-Type Small, Acid-soluble Spore Proteins from Bacillus Species

The binding of α/β-type small, acid-soluble spore proteins (SASP) to DNA of spores of Bacillus species is the major determinant of DNA resistance to a variety of damaging treatments. The primary sequence of α/β-type SASP is highly conserved; however, the N-terminal third of these proteins is less well conserved than the C-terminal two-thirds. To determine the functional importance of residues in the N-terminal region of α/β-type SASP, variants of SspC (a minor α/β-type SASP from Bacillus subtilis) with modified N termini were generated and their structural and DNA binding properties studied in vitro andin vivo. SspC variants with deletions of up to 14 residues (∼20% of SspC residues) were able to bind DNA in vitroand adopted similar conformations when bound to DNA, as determined by circular dichroism spectroscopy and protein-protein cross-linking. Progressive deletion of up to 11 N-terminal residues resulted in proteins with progressively lower DNA binding affinity. However, SspCΔ14 (in which 14 N-terminal residues have been deleted) showed significantly higher affinity for DNA than the larger proteins, SspCΔ10 and SspCΔ11. The affinity of these proteins for DNA was shown to be largely dependent upon the charge of the first few N-terminal residues. These results are interpreted in the context of a model for DNA-dependent α/β-type SASP protein-protein interaction involving the N-terminal regions of these proteins.
Ligand binding to heme proteins: III. FTIR studies of His-E7 and Val-E11 mutants of carbonmonoxymyoglobin

Fouier-transform infrared (FTIR) difference spectra of several His-E7 and Val-E11 mutants of sperm whale carbonmonoxymyoglobin were obtained by photodissociation at cryogenic temperatures. The IR absorption of the CO ligand shows characteristic features for each of the mutants, both in the ligand-bound (A) state and in the photodissociated (B) state. For most of the mutants, a single A substate band is observed, which points to the crucial role of the His-E7 residue in determining the A substrate spectrum of the bound CO in the native structure. The fact that some of the mutants show more than one stretch band of the bound CO indicates that the appearance of multiple A substates is not exclusively connected to the presence of His-E7. In all but one mutant, multiple stretch bands of the CO in the photodissociated state are observed; these B substates are thought to arise from discrete positions and/or orientations of the photodissociated ligand in the heme pocket. The red shifts of the B bands with respect to the free-gas frequency indicate weak binding in the heme pocket. The observation of similar red shifts in microperoxidase (MP-8), where there is no residue on the distal side, suggests that the photodissociated ligand is still associated with the heme iron. Photoselection experiments were performed to determine the orientation of the bound ligand with respect to the heme normal by photolyzing small fractions of the sample with linearly polarized light at 540 nm.(ABSTRACT TRUNCATED AT 250 WORDS)
Nutrient effects on autofragmentation of Myriophyllum spicatum

Abstract The effects sediment nitrogen and water potassium concentrations have on autofragment production of Eurasian watermilfoil ( Myriophyllum spicatum L.) were studied utilizing 16 mesocosms with four mesocosms per treatment. Results indicated that a sediment nitrogen concentration of 0.04 mg NH 3 -N g −1 sediment significantly increased autofragment production. Plants grown for 12 weeks in this low nitrogen regime produced 1616 autofragments while high nitrogen treated plants (0.55 mg NH 3 -N g −1 sediment) produced 712 autofragments. Potassium concentration did not significantly alter autofragment production. Up to 50% of autofragments abscised from parent plants grown under low nitrogen conditions compared to 12% or less when grown under high nitrogen conditions. Within 10 days of initiating adventitious roots, 16–38% of autofragments broke away from parent plants grown under low nitrogen regimes compared to 10% of autofragments grown under high nitrogen regimes. Plant components (inflorescence, autofragment, stem and root crown) contained equivalent percentages of total nonstructural carbohydrates (TNCs) by the 9th week of growth; however, low nitrogen treated plants were producing more autofragment and stem biomass. The combination of these factors indicates that Eurasian watermilfoil grown in a low nitrogen environment directs more resources toward autofragment and stem production, allowing colonization of new potential sites. In contrast, when grown in a high nitrogen environment, this species directs more of its energy toward stem and root crown development, allowing for regrowth and colonization in the immediate area.
Neuroendocrine Responses to a Cold Pressor Stimulus in Polydipsic Hyponatremic and in Matched Schizophrenic Patients

Schizophrenia, many believe, reflects an enhanced vulnerability to psychological stress. Controlled exposure to stressors, however, has produced inconclusive results, particularly with regards to neurohormones. Some of the variability may be attributable to the nature and psychological significance of the stimulus and failure to control physiologic confounds. In addition, it is possible that the heterogeneity of schizophrenia is an important factor. In a carefully designed study and in a controlled setting, we measured the neuroendocrine response of eight polydipsic hyponatremic (PHS), seven polydipsic normonatremic (PNS), and nine nonpolydipsic normonatremic (NNS) (ie normal water balance) schizophrenic in-patients as well as 12 healthy controls (HC) to two different stressors: one of which appears to influence neuroendocrine secretion through its psychological (cold pressor) and the other (upright posture) through its systemic actions. Subjects in the three psychiatric groups were stabilized and acclimated to the research setting, and all received saline to normalize plasma osmolality. Following the cold pressor, plasma adrenocorticotropin and cortisol levels showed a more prolonged rise in PHS patients relative to PNS patients. NNS patients, in contrast, exhibited blunted responses relative to both of the polydipsic groups and the HC. Peak vasopressin responses were also greater in PHS and blunted in NNS patients. Responses to the postural stimulus were similar across patient groups. These findings provide a mechanism for life threatening water intoxication in schizophrenia; help to reconcile conflicting findings of stress responsiveness in schizophrenia; and potentially identify a discrete patient subset with enhanced vulnerability to psychological stress.
Regulation of the peptide elongation reaction on uterine ribosomes by estrogens.

Abstract Administration of 17β-estradiol to ovariectomized mature rats for 1 h induces an increased capacity of subsequently isolated uterine ribosomes to synthesize protein in a cell-free protein synthesis system. The increased rate of protein synthesis can be ascribed to an effect of estrogen on the rate of peptide elongation rather than synthesis of additional new peptides. The increased rate of peptide elongation is dependent upon the dose of estradiol over the range of 0.1 to 10 μg/animal, and exhibits hormone specificity: 17β-estradiol, diethylstilbesterol, estrone and estriol but not 17α-estradiol, progesterone, dihydrotestosterone or corticosterone will induce the response. Removal of ribosome associated proteins by extraction with 0.5 M KCl results in activation of protein synthesis by uterine ribosomes from control rats to rates that are equal to that of ribosomes from estrogen-stimulated rats suggesting that ribosomes from control animals are in an inhibited state. The KCl extracted ribosomal factors from control animals inhibit the synthesis of protein by salt-washed uterine ribosomes when added back to the ribosomes prior to assay and the inhibitory properties of these factors are greater if derived from ribosomes of control rather than 1 h estradiol-treated rats. The extracted inhibitor is inactivated by heat, is insensitive to treatment with N -ethylmaleimide, is insensitive to micrococcal nuclease and is reversible. The early activation of uterine ribosomes by estrogen appears to result from either the removal or inactivation of ribosome associated-peptide elongation reaction, inhibitory factor.
Lipid composition influences the shape of human low density lipoprotein in vitreous ice.

Earlier cryo-electron microscopic studies have indicated that the normal low density lipoprotein (N-LDL) has a discoid shape when its core is in the liquid-crystalline state. In the present study, we investigated whether the shape of LDL depends on the physical state and/or the lipid composition of the lipoprotein core. Using a custom-built freezing device, we vitrified N-LDL samples from either above or below the phase-transition temperature of the core (42 and 24°C, respectively). Cryo-electron microscopy revealed no differences between these samples and indicated a discoid shape of the N-LDL particle. In contrast, TG-enriched LDL (T-LDL) did not have discoid features and appeared to be quasi-spherical in preparations that were vitrified from either 42 or 24°C. These results suggest that the shape of N-LDL is discoid, regardless of the physical state of its core, whereas T-LDL is more spherical. Aspects that may influence the shape of LDL are discussed.
A brief overview of electromagnetic precursors

Unique properties of electromagnetic precursors in causally dispersive media are described from both mathematical and physical perspectives.
Substance P does not play a critical role in neurogenic inflammation in the rat masseter muscle

In this study, we performed a series of experiments to investigate whether substance P (SP) contributes to neurogenic inflammation in the skeletal muscle tissue. Intramuscular injection of an inflammatory irritant, mustard oil (MO), induces significant edema formation in the rat masseter muscle. In order to study the contribution of endogenous SP in the MO-induced edema, groups of rats were pretreated with two different doses (100 nmol; 1 microl) of either peptidergic (Sendide) or non-peptidergic (L703, 606) neurokinin 1 (NK1) receptor antagonist in one masseter muscle 15 min prior to the MO injection in the same muscle. The extent of edema was assessed as the percent weight difference of the injected muscle compared to the non-injected muscle. Neither Sendide nor L703,606 pretreatment resulted in a significant inhibition of the MO-induced edema in the masseter muscle. Exogenous application of SP also produced a significant swelling of the muscle, which was blocked by L703,606 (1 microl) pretreatment, suggesting that evoked release of SP following MO injection is not sufficient to induce significant edema formation. Capsaicin (1% in 25 microl), which is known to cause neurogenic inflammation, failed to produce edema formation in the masseter muscle. The same concentration of capsaicin injected into the hindpaw produced significant swelling of the injected paw. Taken together, these results provide compelling evidence that, unlike cutaneous or joint tissue, SP does not play a critical role in inducing neurogenic inflammation in the skeletal muscle tissue.
Low-energy pion-nucleon scattering

An analysis of low-energy charged pion-nucleon data from recent ${\ensuremath{\pi}}^{\ifmmode\pm\else\textpm\fi{}}p$ experiments is presented. From the scattering lengths and the Goldberger-Miyazawa-Oehme (GMO) sum rule we find a value of the pion-nucleon coupling constant of ${f}^{2}=0.0756\ifmmode\pm\else\textpm\fi{}0.0007$. We also find, contrary to most previous analyses, that the scattering volumes for the ${P}_{31}$ and ${P}_{13}$ partial waves are equal, within errors, corresponding to a symmetry found in the Hamiltonian of many theories. For the potential models used, the amplitudes are extrapolated into the subthreshold region to estimate the value of the $\ensuremath{\Sigma}$ term. Off-shell amplitudes are also provided.
Sublethal effects of pentachlorophenol in the abalone (haliotis rufescens) as measured by in vivo 31P NMRSpectroscopy

The sublethal biochemical effects of pentachlorophenol (PCP) were investigated in live, intact red abalones (Haliotis rufescens), using a flow-through exposure system, by in vivo 31P NMR spectroscopy. Based on rangefinding tests (6-hr LC50 = 1.6 mg/L; 6-hr no-observable-effect-level (NOEL) = 0.8 mg/L), three abalones were separately exposed to a sublethal concentration (1.2 mg/L) for 5 hr, followed by a 13 hr recovery period. Effects in foot muscle included both a decrease in phosphoarginine and an increase in inorganic monophosphate concentrations ([PA] and [Pi], respectively); both foot muscle concentrations of adenosine triphosphate [ATP] and intracellular pH (pHi) also declined. Parallel in vitro experiments revealed that concentrations of glycerol 3-phosphate, lactate, citrate, succinate, malate, and alanine (Ala) all increased, while those of glyceraldehyde 3-phosphate and glutamine (Gln) remained stable. Also, these effects were not evident until 2 hr into exposure, possibly the time required for PCP to attain an effective concentration in foot muscle. During recovery, while Pi declined to pre-exposure levels, [PA] completely recovered in only one individual. Also, realkalinization of pHi was similar to recovery of [Pi], and ATP returned to near-initial levels, as did glycerol 3-phosphate, lactate, succinate, malate, and Ala; glyceraldehyde 3-phosphate, citrate, and Gln levels declined. Recovery responses corresponded to the time for PCP clearance from foot muscle. The effects of PCP were similar to those of hypoxia, fatigue, hypersalinity, and arginine kinase inhibitors, and so sublethal PCP concentrations may also inhibit electron transport and arginine kinase as well as uncouple mitochondrial oxidative phosphorylation in intact molluscs. Thus, the effects of pollutants on key biochemical processes may now be measured in intact aquatic organisms as they occur, improving our ability to accurately assess the environmental effects of pollutants in the laboratory.
Pharmacodynamics of Isoflupredone Acetate in an Endotoxin-Induced Mastitis Model

The effect of intravenous administration of the steroidal drug isoflupredone acetate on lactating dairy cows with mastitis induced using gram-negative bacterial endotoxin was investigated. Cows were randomly assigned to one of four treatment groups: untreated controls, isoflupredone acetate only, mastitis only, and mastitis plus isoflupredone acetate. Isoflupredone acetate was given to treated groups at a dose of 20 mg intravenously, once. Mastitic cows receiving treatment were given isoflupredone acetate after the development of clinical signs. When compared with untreated mastitic controls, cows with endotoxin-induced mastitis treated with isoflupredone acetate did not exhibit measurable differences in heart rate, rectal temperature, rumen motility, or changes in mammary gland surface area in the 14 h following the administration of intramammary endotoxin. Healthy cows treated with isoflupredone acetate had a higher heart rate over the 14 h after drug administration than did untreated healthy controls. When compared with untreated mastitic controls, cows treated with isoflupredone acetate did not exhibit statistically significant differences in milk production following endotoxin-induced mastitis.
THE VISUAL EXPERIENCE OF CAUSATION

The thesis that we can visually perceive causal relations is distinct from the thesis that visual experiences can represent causal relations. I defend the latter thesis about visual experience, and argue that although they are suggestive, the data provided by Albert Michotte's experiments on perceptual causality do not establish this thesis. Turning to the perception of causality, I defend the claim that we can perceive causation against the objection that its arcane features are unlikely to be represented in experience.
Hypernetted-chain Euler-Lagrange equations and the electron fluid

Least upper bounds to the ground-state energy of the electron fluid are obtained by solving Euler-Lagrange equations obtained within the framework of Fermi hypernetted-chain theory for arbitrary density and spin polarization. It is shown that the so-obtained approximate distribution and structure functions satisfy known exact relations in the high- and low-density limits as well as in the long-wavelength limit at any density. The numerical results are in excellent agreement with coupled-cluster perturbational and Monte Carlo type calculations. As a by-product a simple analytic solution accurate in the high-density limit is obtained which is superior to the random-phase approximation in the metallic density regime.
Effects of nerve segment supernatants on cultured Schwann cell proliferation and laminin production.

Mouse sciatic nerves were transected and 3 hr to 16 days later proximal segments were removed and homogenized. Supernatants of these segments or of normal sciatic nerves were added to Schwann cells maintained in Dulbecco's modified Eagle's medium (DMEM) + 15% fetal calf serum (FCS). After 6 days, Schwann cells were solubilized and the protein content was measured using a Bio-Rad (Melville, NY) protein assay. Samples containing the same amounts of protein were then applied to microtiter plates and the laminin content was determined by enzymelinked immunosorbent assay (ELISA). Lysates of cultures treated with 24 hr proximal segment supernatants contained significantly higher levels of laminin than those prepared from other intervals, from distal segments, or from control nerves. Increased surface and cytoplasmic anti-laminin immunoreactivity also was found in Schwann cells treated with 24 hr supernatants. To identify the source(s) of this effect, proximal segments removed 24 hr after transection were bisected; supernatants were prepared from each half and tested. Significant increases in laminin production were produced by supernatants from both halves. When supernatants from proximal and distal halves were compared, the latter produced significantly higher laminin levels. Electron microscopic examination of both halves showed that distal halves contained sprouting neurites and growth cones ensheathed by Schwann cells which had a basal lamina and resembled those seen during development and regeneration. Proximal halves appeared normal. Schwann cell proliferation also was compared in supernatant-treated cultures by using a bromodeoxyuridine (BrdU) ELISA. The 24 hr and 2 day supernatants increased Schwann cell proliferation significantly; 12 hr, 4 day, and 8 day supernatants produced smaller increases. Our observations suggest that axons undergoing early regenerative changes are one of several possible sources of substance(s) in our proximal segment supernatants which increased Schwann cell proliferation and laminin production. © 1994 Wiley-Liss, Inc.