cssi/SciSciGPT-SciSciNet huggingface dataset:
Neuroproteomics Approaches to Decipher Neuronal Regeneration and Degeneration

Given the complexity of brain and nerve tissues, systematic approaches are essential to understand normal physiological conditions and functional alterations in neurological diseases. Mass spectrometry-based proteomics is increasingly used in neurosciences to determine both basic and clinical differential protein expression, protein-protein interactions, and post-translational modifications. Proteomics approaches are especially useful to understand the mechanisms of nerve regeneration and degeneration because changes in axons following injury or in disease states often occur without the contribution of transcriptional events in the cell body. Indeed, the current understanding of axonal function in health and disease emphasizes the role of proteolysis, local axonal protein synthesis, and a broad range of post-translational modifications. Deciphering how axons regenerate and degenerate has thus become a postgenomics problem, which depends in part on proteomics approaches. This review focuses on recent proteomics approaches designed to uncover the mechanisms and molecules involved in neuronal regeneration and degeneration. It emerges that the principal degenerative mechanisms converge to oxidative stress, dysfunctions of axonal transport, mitochondria, chaperones, and the ubiquitin-proteasome systems. The mechanisms regulating nerve regeneration also impinge on axonal transport, cytoskeleton, and chaperones in addition to changes in signaling pathways. We also discuss the major challenges to proteomics work in the nervous system given the complex organization of the brain and nerve tissue at the anatomical, cellular, and subcellular levels.
Uniform Thin Films of CdSe and CdSe(ZnS) Core(shell) Quantum Dots by Sol-Gel Assembly: Enabling Photoelectrochemical Characterization and Electronic Applications

Optoelectronic properties of quantum dot (QD) films are limited by (1) poor interfacial chemistry and (2) nonradiative recombination due to surface traps. To address these performance issues, sol–gel methods are applied to fabricate thin films of CdSe and core(shell) CdSe(ZnS) QDs. High-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM) imaging with chemical analysis confirms that the surface of the QDs in the sol–gel thin films are chalcogen-rich, consistent with an oxidative-induced gelation mechanism in which connectivity is achieved by formation of dichalcogenide covalent linkages between particles. The ligand removal and assembly process is probed by thermogravimetric, spectroscopic, and microscopic studies. Further enhancement of interparticle coupling via mild thermal annealing, which removes residual ligands and reinforces QD connectivity, results in QD sol–gel thin films with superior charge transport properties, as shown by a dramatic enhancement of electrochemical p...
Conditional Mean Spectrum: Tool for Ground-Motion Selection

A common goal of dynamic structural analysis is to predict the response of a structure subjected to ground motions having a specified spectral acceleration at a given period. This is important, for example, when coupling ground motion hazard curves from probabilistic seismic hazard analysis with results from dynamic structural analysis. The prediction is often obtained by selecting ground motions that match a target response spectrum, and using those ground motions as input to dynamic analysis. The commonly used Uniform Hazard Spectrum (UHS) is shown here to be an unsuitable target for this purpose, as it conservatively implies that large-amplitude spectral values will occur at all periods within a single ground motion. An alternative, termed a Conditional Mean Spectrum (CMS), is presented here. The CMS provides the expected (i.e., mean) response spectrum, conditioned on occurrence of a target spectral acceleration value at the period of interest. It is argued that this is the appropriate target response spectrum for the goal described above, and is thus a useful tool for selecting ground motions as input to dynamic analysis. The Conditional Mean Spectrum is described, its advantages relative to the UHS are explained, and practical guidelines for use in ground motion selection are presented. Recent work illustrating the impact of this change in target spectrum on resulting structural response is briefly summarized.
Feeding fears: competing discourses of interdependency, sovereignty, and China's food security

Abstract Following the release of the 1994 report ‘Who will feed China?’ by the Worldwatch Institute, there has been much debate over the implications of China's growing demand for grain. The question of China's food production has elicited a variety of responses. While for some it raises the specter of regional and global instability as China becomes an environmental threat, for others the entrance of China into the world market promises increased trade and profits. In this paper I explore the responses in China and the US to the different notions of interdependence which have shaped the debate. I first turn to how concerns over China's food supply have, despite appeals to the concepts of global environmental and economic interdependence, become linked to classical state-centered geopolitical concerns such as ‘sovereignty’ and ‘containment.’ I then look at how the debate has also been actively distanced from national security concerns through the invocation of an alternative interdependence founded on the logic of commerce. I conclude by arguing for the need within critical geopolitics to further examine the circulation of strategic texts between and within states, particularly in the analysis of texts that map worlds beyond the boundaries of North America and Europe.
Stented Artery Biomechanics in the Presence of Stenoses and Tapering

The implantation of a balloon expandable stent induces chronic stent-induced stresses on the artery wall. These highly non-physiologic stresses can provoke inflammation and smooth muscle cell proliferation. Ultimately, this cascade of events leads to restenosis, or the development of a new blockage in the stented artery. Since the initial human implantation of balloon expandable stents, technological advances in stent design, material properties, and deliverability have expanded the application and success rate of the procedure. More recently, anti-restenotic strategies such as drug-eluting stents have aimed to counteract the restenosis process. While clinical trials have demonstrated the success of drug eluting stents in coronary arteries [1], risk of late thrombosis [2] and failure to prevent restenosis in peripheral arteries [3] has limited this technology. A further investigation into the artery wall stresses induced by stent implantation, and the pursuit of strategies to minimize them could reduce the restenosis rates for both bare metal and drug-eluting stents.Copyright © 2007 by ASME
“I’ll Get That for You”: The Relationship Between Benevolent Sexism and Body Self-Perceptions

Benevolent sexism has been shown to have negative consequences for women. In the present study, we investigated whether there were differences in reports of body self-perceptions between 93 college women in the southeastern United States who either witnessed or did not witness a staged act of benevolent sexism. Because we believed that benevolent sexism could make beauty norms more salient, we hypothesized that women who witnessed benevolent sexism would report higher levels of self-objectification, body surveillance, and body shame. Women who witnessed benevolent sexism did report higher levels of surveillance and shame, constructs associated with self-objectification, but not higher general levels of self-objectification. This research provides more evidence of the negative effects benevolent sexism has on women.
Purification, characterization, and localization of a 29 ku (kilodalton) glycoprotein from the edible tubers of Apios americana Medikus

Summary Total proteins from Apios americana Medikus tubers were resolved by SDS-PAGE into several abundant polypeptides of approximate molecular masses of 55, 42, 29, 22 and 14ku (kDa). These proteins accumulated in a coordinate fashion during tuber development. We purified the 29 ku protein by ammonium sulfate precipitation, extraction with 70 % ethanol, and affinity chromatography on Con-A Sepharose. The amino acid composition of the purified 29 ku polypeptide revealed a low content of methionine and tyrosine. The N-terminal sequence of the purified 29 ku protein, EAKLPFFVFNLDRFF, showed no significant homology to any known protein sequences. Mannose, glucose, galactose and N-Ac-glucosamine were detected by gas-liquid chromatography as the glycan components of the purified 29 ku glycoprotein. Antisera raised against the purified 29 ku glycoprotein contained antibodies directed against both the polypeptide moiety and the glycan side chains. Transmission electron microscopy immunocytochemical localization studies revealed that the 29 ku glycoprotein was found as discrete protein aggregates within vacuoles of Apios tuber cells.
Understanding Dropout in an Urban Worker Education Program: Retention Patterns, Demographics, Student Perceptions, and Reasons Given for Early Departure

This study seeks reasons for dropout from an urban basic education program for paraprofessional health care workers in which the retention rate was 47%. Demographics, students' perceptions of the program, and reasons given by dropouts for early departure were compared across four groups: Completers, Non-Completers, Leavers, and Non-Attenders, the last two of which are often overlooked in the literature. The groups differed significantly in terms of previous college experience, attainment of education goal, judgment of instructional level, and perceived usefulness of instructional materials. The Non-Completers and Leavers stated similar reasons for early departure, except where family matters were concerned.
The Effect of Overlearning on Long-Term Retention

Once material has been learned to a criterion of one perfect trial, further study within the same session constitutes overlearning. Although overlearning is a popular learning strategy, its effect on long-term retention is unclear. In two experiments presented here, 218 college students learned geography facts (Experiment 1) or word definitions (Experiment 2). The degree of learning was manipulated and measured via multiple test-with-feedback trials, and participants returned for a final cued recall test between one and nine weeks later. The overlearners recalled far more than the low learners at the one-week test, but this difference decreased dramatically thereafter. These data suggest that overlearning (and its concomitant demand for additional study time) is an inefficient strategy for learning material for meaningfully long periods of time.
Tumor Necrosis Factor-α-mediated Regulation of the Inositol 1,4,5-Trisphosphate Receptor Promoter

Tumor necrosis factor-α (TNF-α), a proinflammatory cytokine, has been implicated as a central mediator in multiple homeostatic and pathologic processes. Signaling cascades downstream of its cellular cognate receptors, as well as the resultant transcriptional responses have received intense interest in regards to how such signals impact cellular physiology. Notably, TNF-α was shown to potentiate neuronal Ca2+ signaling by enhancing type-1 inositol 1,4,5-trisphosphate receptor (IP3R) steady-state mRNA levels. In the present study, we sought to determine the promoter region ultimately responsive to TNF-α exposure. We report that a sequence encompassing a specificity protein 1 (SP-1) binding site is necessary for TNF-α regulation. Electrophoretic mobility shift analysis demonstrated specific binding to this sequence, while site-directed mutagenesis of this site abrogated both JNK-mediated regulation as well as transcription factor binding. Expression of a dominant-negative SP-1 eliminated both the enhanced promoter activity and the elevated IP3R-mediated Ca2+ signals observed with TNF-α exposure. Overall, these data delineate a key pathway by which TNF-α in a neuronal environment modulates IP3R expression and intracellular Ca2+ homeostasis.
“Acquired” lobar emphysema: A complication of respiratory distress in premature infants

Abstract Ten premature infants with respiratory distress developed a type of pulmonary lobar emphysema that is clinically and histologically distinct from interstitial or congenital lobar emphysema. In eight patients emphysema was noted in the right lower lobe, while in two the left upper lobe was affected. Five infants exhibited nonresolution of the emphysema and an inability to be weaned from ventilator support. Lung scans in these five infants showed absent or markedly decreased perfusion of the involved lobe. Lobectomy was necessary. Postoperatively, their respiratory status improved and they were successfully weaned from the ventilator. Five premature infants with identical radiographic emphysematous changes had normal lung scans. These infants did not require lobectomy and were also successfully weaned from the ventilator. Radiographic changes of lobar emphysema in these five infants completely resolved. Pathologic changes in the excised lobes were characteristic of bronchopulmonary dysplasia and obstructive intraalveolar emphysema. The long-term effects of positive pressure ventilation, oxygen, and suctioning techniques directed toward the right lower lobe may play an important role in the etiology of "acquired" lobar emphysema.
Following Universal Prophylaxis with Intravenous Ganciclovir and Cytomegalovirus Immune Globulin, Valganciclovir is Safe and Effective for Prevention of CMV Infection Following Lung Transplantation

We prospectively determined the safety and efficacy of valganciclovir for prevention of cytomegalovirus (CMV) in at-risk (donor positive/recipient negative [D+/R-] or R+) lung transplant recipients. We also determined the length of prophylaxis required to significantly decrease both CMV infection and disease. Consecutive lung transplant recipients surviving >30 days (n = 90) received combination prophylaxis with intravenous (i.v.) ganciclovir (GCV) 5 mg/kg/day and cytomegalovirus immune globulin (CMV-IVIG) followed by valganciclovir (450 mg twice-daily) to complete 180, 270 or 365 days of prophylaxis. This group was compared to a historical group (n = 140) who received high-dose oral acyclovir following i.v. GCV and CMV-IVIG. CMV disease was significantly lower in patients receiving valganciclovir compared to acyclovir (2.2% vs. 20%; p < 0.0001). Freedom from CMV infection and disease was significantly greater (p < 0.02) in patients receiving 180, 270 or 365 days of prophylaxis (90%, 95% and 90%, respectively) compared to those receiving 100-179 days (64%) or < 100 days (59%). No patient receiving valganciclovir died during the study. Following prophylaxis with i.v. GCV and CMV-IVIG, valganciclovir is safe and effective for prevention of CMV infection and disease in at-risk lung transplant recipients. The required length of prophylaxis was at least 180 days.
Comparative yttrium and rare earth element chemistries in seawater

Abstract Comparisons of yttrium and rare earth stability constants for organic ligands indicate that Y(III)-organic complexation behavior most closely resembles, on average, the complexation characteristics of Sm(III). Yttrium organic complexation behavior distinctly differs from the behavior of Ho(III), whose ionic radius is most similar to that of yttrium. However, our stability constant comparisons demonstrate that the most reliable basis for predicting Y(III) organic stability constants are predictions based on the complexation behavior of Ho(III). Linear free energy relationships between Ho(III) and Y(III) exhibit better fits than those obtained for other rare earth elements, and much better fits than those obtained between Sm(III) and Y(III). The comparative abundances and distributions of yttrium and the rare earths in seawater are controlled by competitive equilibria between inorganic solution ligands and organic surface ligands. Due to yttrium solution complexation with hard inorganic ligands resembling that of Ho(III) and, yttrium surface complexation with soft organic ligands resembling that of light rare earth elements, the input normalized abundances of yttrium and the rare earths should be decoupled in seawater. In its seawater scavenging behavior, yttrium should act as a pseudolanthanide even heavier than the heaviest rare earth element, lutetium.
Evaluation of low-dose CT angiography with model-based iterative reconstruction after endovascular aneurysm repair of a thoracic or abdominal aortic aneurysm

OBJECTIVE. The objective of our study was to evaluate image quality and overall adequacy of low-dose CT angiography (CTA) with model-based iterative reconstruction (MBIR) in patients who had undergone endovascular aneurysm repair (EVAR) of a thoracic or abdominal aortic aneurysm. MATERIALS AND METHODS. Thirty patients, all of whom had undergone standard-dose CTA performed previously with adaptive statistical iterative reconstruction (ASIR), underwent low-dose CTA for surveillance after EVAR. Two radiologists randomly evaluated both studies, and quality parameters were assessed. The maximal aneurysm diameter was measured, and the images were evaluated to see whether an endoleak was present. The image noise and contrast-to-noise ratio (CNR) were measured. The volume CT dose index and dose-length product were recorded. RESULTS. The mean image score for low-dose CTA was acceptable to very good in all categories of assessment. There was no significant difference between low-dose CTA and standard-dose CTA in th...
A Configurable Processor Synthesis System

In this paper we present a configurable digital signal processor synthesis (CPS) System that produces a library of high-performance processors wherein each processor executes a specific digital signal processing (DSP) algorithm. Each processor contains a small instruction set and implements a particular application. These algorithm specific DSPs (ASDSPs) are used to alleviate bottlenecks in software by replacing computationally intense portions of a high level DSP algorithm with custom hardware. Each ASDSP generated by the CPS system is individually loaded into a commercially available configurable system. A library of algorithm specific DSPs for a sample application set of fundamental complex arithmetic modules is generated using the CPS system. The resulting library of floating point processors is implemented on a Firebird FPGA board containing a Virtex XCV2000E FPGA part. The results are compared with a comparable software algorithm implemented on a 2.79 GHz Pentium IV general purpose processor. This comparison shows that, despite having a clock speed that is an order of magnitude slower than the microprocessor (54 MHZ versus 2.79 GHZ), the proposed ASDSP ran an order of magnitude (13X) faster than the microprocessor implementation in the best case.
The Narrowband Ultraviolet Imaging Experiment for Wide-Field Surveys. I. Dust-scattered Continuum

We report on the first results of NUVIEWS, a sounding rocket experiment designed to map the far-UV background in four narrow UV bands. This is the first imaging measurement of the UV background to cover a substantial fraction of the sky. In our first flight, we mapped one-quarter of the sky with ~5'-10' imaging resolution. We present a map of the continuum background obtained in the 1740 A telescope and use a model based upon the multiple scattering approach of Witt, Friedman, & Sasseen and a three-dimensional stellar distribution to constrain the dust and other parameters. We find that the dust in the diffuse interstellar medium displays a moderate albedo (a = 0.45 ± 0.05) and highly forward scattering phase function parameter (g = 0.77 ± 0.1) over a large fraction of the sky, similar to the result found for a more restricted area by Witt, Friedman, & Sasseen. We have also discovered a significant variance from the model and shown that it is a natural property of the statistics of clouds with varying multiple scattering geometries. The coverage and quality of our data allows us to place simultaneous constraints on a, g, the extragalactic background (200 ± 100 CU), a slant cosecant (airglow) contribution (~200 CU), and an instrumental scattering component (40 ± 30 CU).
Cryptographic scalability challenges in the smart grid (extended abstract)

In the envisioned smart grid, massive numbers of computational devices will need to authenticate to each other. For scalability, this technology will probably rest on public-key infrastructure (PKI). However, deploying PKI on an entity population this large—and doing the kinds of things we envision the smart grid doing—itself raises many scalability challenges the community will need to address. We survey some.
Telling the Columbia Story Source Selection in News Accounts of a Shuttle Accident

This content analysis of newspaper stories seeks to answer three questions about the Columbia space shuttle disaster: What sources did journalists cite in telling the Columbia story? What did those...
Self-reported racism and social support predict blood pressure reactivity in blacks

This study explored the effects of perceived racism and social support (quantity and quality) on blood pressure reactivity. In a college sample of 64 Blacks (M age = 22.69 years, SD = 6.60), systolic blood pressure (SBP) and diastolic blood pressure (DBP) were assessed before and during a standardized serial subtraction task. Perceptions of racism and the quantity and quality of social support were measured by self- report. Separate multiple regression analyses revealed that perceived racism and social support (neither quantity nor quality) were not independent predictors of SBP or DBP changes (ps > .05). These analyses did indicate that perceived racism interacted with the quantity of social support (p < .002, partial R2 = .175) and with the quality of social support (p < .0007, partial R2 = .195) to predict DBP changes. Perceived racism also interacted with the quantity of social support to predict changes in SBP (p < .02, partial R2 = .11). In general, whereas high social support was related to less marked blood pressure changes under conditions of low perceived racism, high social support was associated with exaggerated blood pressure changes under conditions of high perceived racism. These significant interaction effects persisted after statistically controlling for potential confounders. The findings highlight the importance of examining the joint contribution of real- world experiences and coping resources to blood pressure reactivity in Blacks.
HOMELESSNESS AND ECONOMIC RESTRUCTURING

The rise in homelessness in U.S. cities is partially an outcome of change in industrial composition and labor requirements which have reduced the income-earning abilities of workers at the lowest skill levels of the labor market. In downtown Los Angeles, absolute job loss in some manufacturing industries, decline in the relative share of low-skill jobs, and the decline in real wages among the low-skilled all contributed to the worsening situation of downtown low-skill workers. These were combined with (a) demand for local housing from the growing high-skill/high-wage workforce downtown, (b) pressure from industrial and commercial activities on sites of low-cost housing in and around downtown, (c) housing demolition to meet seismic standards, and (d) massive inflows of poor immigrants from Asia and Central America to the inner city. The outcome was increased competition for housing, leading to rising rentals, overcrowding, illegal construction of substandard backyard shelters, displacement of fixed-income ...
Behavioral and neurochemical pharmacology of six psychoactive substituted phenethylamines: mouse locomotion, rat drug discrimination and in vitro receptor and transporter binding and function

Psychoactive-substituted phenethylamines 2,5-dimethoxy-4-chlorophenethylamine (2C-C); 2,5-dimethoxy-4-methylphenethylamine (2C-D); 2,5-dimethoxy-4-ethylphenethylamine (2C-E); 2,5-dimethoxy-4-iodophenethylamine (2C-I); 2,5-dimethoxy-4-ethylthiophenethylamine (2C-T-2); and 2,5-dimethoxy-4-chloroamphetamine (DOC) are used recreationally and may have deleterious side effects. This study compares the behavioral effects and the mechanisms of action of these substituted phenethylamines with those of hallucinogens and a stimulant. The effects of these compounds on mouse locomotor activity and in rats trained to discriminate dimethyltryptamine, (−)-DOM, (+)-LSD, (±)-MDMA, and S(+)-methamphetamine were assessed. Binding and functional activity of the phenethylamines at 5-HT1A, 5-HT2A, 5-HT2C receptors and monoamine transporters were assessed using cells heterologously expressing these proteins. The phenethylamines depressed mouse locomotor activity, although 2C-D and 2C-E stimulated activity at low doses. The phenethylamines except 2C-T-2 fully substituted for at least one hallucinogenic training compound, but none fully substituted for (+)-methamphetamine. At 5-HT1A receptors, only 2C-T-2 and 2C-I were partial-to-full very low potency agonists. In 5-HT2A arachidonic acid release assays, the phenethylamines were partial to full agonists except 2C-I which was an antagonist. All compounds were full agonists at 5-HT2A and 5-HT2C receptor inositol phosphate assays. Only 2C-I had moderate affinity for, and very low potency at, the serotonin transporter. The discriminative stimulus effects of 2C-C, 2C-D, 2C-E, 2C-I, and DOC were similar to those of several hallucinogens, but not methamphetamine. Additionally, the substituted phenethylamines were full agonists at 5-HT2A and 5-HT2C receptors, but for 2C-T-2, this was not sufficient to produce hallucinogen-like discriminative stimulus effects. Additionally, the 5-HT2A inositol phosphate pathway may be important in 2C-I's psychoactive properties.
Immunoreactivity between a monoclonal lupus autoantibody and the arginine/aspartic acid repeats within the U1-snRNP 70K autoantigen is conformationally restricted.

Immunoreactivity of the arginine/aspartic acid (RD) repeats of the 70K protein of U1 small nuclear ribonucleoprotein (snRNP) was determined to be conformationally dependent. The monoclonal autoantibody 2.73, isolated from a lupus-prone MRL/n mouse model, is reactive with the RD repeat regions of U1 snRNP 70K protein. Immunochemical analysis of the antigenic determinants with use of chemically synthesized peptides characterized the 2.73 epitope as the RD repeat [Pelsue, S.,et al. (1993)Autoimmunity,15, 231–236] Analysis by circular dichroism (CD) and nuclear magnetic resonance spectroscopy indicates conformational preferences in the immunoreactive peptides. Computer analyses of CD spectra obtained on the RD-containing peptides predictβ-turns andβ-sheet to be the preferred conformations of the RD repeats. This structure was also predicted by the Chou-Fasman algorithm. The RD repeat is believed to be a conserved structural motif; however, the biological function is still unclear. Immunological and biochemical analysis of autoimmune antibodies and their respective antigenic determinants has helped to characterize the possible mechanisms that lead to autoimmune diseases. This is the first report of a conformationally dependent, linear epitope of an autoantibody.
Living Related Small Bowel Transplantation: Progress, Pitfalls, and Promise

Multivisceral transplantation has brought new opportunities in the treatment of organ failure, offering better outcomes and quality of life to patients. Standardized surgical technique was developed in 1997. Currently, living donor (LD) intestinal transplant has been perfected relative to technical details, leading results comparable with those performed with deceased donors (DDs). Additional advantages such as elimination of waiting time, better human leukocyte antigen (HLA) matching, short ischemia time, and being scheduled as an elective surgery are achieved with this type of procedure. Regenerative medicine constitutes a pathway of innovate techniques in the treatment of intestinal failure; however, further research needs to be performed to fully translate regenerative medicine into the clinical field.
An inter-segment tunneling nanoscale force sensor: Modeling and simulation

A segmented high aspect ratio nanowire employing the tunneling effect is proposed to theoretically realize non-linear effects in nanoscale force sensing. The structure consists of an external insulating shell with metallic core regions separated at the structure's geometric center. The separation is considered to be in the order of a few Å for the tunneling effect to be pronounced. As the structure is subjected to an axial force at the ends, buckling occurs causing a change in the separation which results in a non-linear change in the current. Force-separation and current-force relations are studied and the high sensitivity of the structure as a force sensor is established.
Prediction of the Lifetime of a Battery-Operated Video Node Using Offline and Online Measurements

This paper presents a model for determining the first and second order statistics of the lifetime of a battery-operated node. This model assumes knowledge of the statistics of duration and consumption of the tasks that can be performed by the system, as well as of the statistics of the task occurrences and of the remaining charge in the battery. The latter may be monitored by an onboard sensor. Knowledge of the remaining lifetime is very important in order to devise an online control strategy assuring that specific requirements are met.
Calcium and Pip2 Interplay Regulates BK Channel Activity via the RCK1 Gating Ring

BK channels are high conductance K+ channels that are activated by voltage and intracellular Ca2+. Ca2+ binds to sites in the RCK2 and RCK1 domains of Slo1, the pore-forming subunit of BK channels, to enhance voltage-dependent gating of the channel. PIP2, a ubiquitous modulator of ion channel activity, enhances Ca2+-driven gating of BK channels but a molecular understanding of this interplay remains elusive. Here, we report that amino acid residues in the RCK2 calcium bowl that bind Ca2+ do not affect PIP2 sensitivity. In contrast, the RCK1 Ca2+ coordination site is intimately involved in PIP2 sensitivity. We identified two critical residues within the alphaB helix, K392 and R393, are directly involved in coordinating PIP2. In the absence of Ca2+, the alphaB helix interacts with the alphaA helix to decrease the apparent affinity of the channel to PIP2 and inhibit channel activity. Ca2+ binding to the RCK1 site engaging D367 of the KDRDD loop relieves the decrease in PIP2 apparent affinity and channel inhibition. Furthermore, mutation of residues in the KDRDD loop or the alphaA/alphaB residues that couple this region to the alphaB PIP2 regulatory site also relieve the decrease in the apparent affinity for PIP2 and current inhibition in the absence of Ca2+. In addition, we show that the PMA-induced current inhibition also exhibits a dependence on channel-PIP2 interactions that determine the extent of modulation. Together these results show that along with Ca2+ and voltage, PIP2 is a critical third factor providing integral control of BK channel activity.
Energy efficiency, technological change and the dieselization of agriculture in the United States

This study focuses on the increase in the relative importance of diesel fuel consumption on farms in the United States over the 1971–1989 period. Four factors are identified as being central to the observed trend. These include the relative efficiency of diesel powered equipment versus gasoline powered equipment, technological changes that have impacted energy efficiency, the trend towards larger farms, and the enhanced energy conservation by farmers as a result of the adoption of reduced tillage practices.
Divergent oncogenic changes influence survival differences between colon and rectal adenocarcinomas.

PURPOSE: Colorectal cancers develop through various mechanisms such as chromosomal instability, DNA mismatch repair deficiency (microsatellite instability), and epigenetic DNA promoter methylation (CpG island methylator phenotype). This study evaluated the disparity in neoplastic changes between colon and rectal cancers. METHODS: A clinic-based colorectal frozen tumor bank at a single institution was queried for colon and rectal adenocarcinomas. Tumor DNA was extracted and analyzed for microsatellite instability, methylation, and mutations in the oncogenes KRAS and BRAF. Patient demographics, tumor characteristics, and clinical outcomes were compared. RESULTS: The 268 patients with colon cancer and 89 with rectal cancer were similar in gender, tumor size, stage, and differentiation. Colon cancers had a higher incidence of microsatellite instability (27 percent) and methylator phenotype (28 percent) compared with rectal cancers (7 percent, 3 percent, respectively; P < 0.001). Although KRAS mutation rate was similar, colon cancers had a higher incidence of BRAF mutations (16.7 percent vs. 0 percent; P < 0.001). Microsatellite stable tumors had an increased risk of disease recurrence compared with microsatellite unstable tumors (odds ratio, 3.86). Despite overall differences in outcome between colon and rectal cancers, no significant difference in survival existed when similar molecular phenotypes were compared across anatomic sites. CONCLUSIONS: Although colon cancers are molecularly heterogeneous, rectal cancers arise mostly via a single neoplastic pathway. Genetic and molecular differences influence prognosis more than anatomic location and suggest that oncogenic pathways contribute to survival differences between colon and rectal cancers.
Phosphorylation of Kaposi's Sarcoma-Associated Herpesvirus Processivity Factor ORF59 by a Viral Kinase Modulates Its Ability To Associate with RTA and oriLyt

ORF59 of Kaposi's sarcoma-associated herpesvirus (KSHV) plays an essential role in viral lytic replication by providing DNA processivity activity to the viral DNA polymerase (ORF9). ORF59 forms a homodimer in the cytoplasm and binds and translocates ORF9 into the nucleus, where it secures ORF9 to the origin of lytic DNA replication (oriLyt) in order to synthesize long DNA fragments during replication. ORF59 binds to oriLyt through an immediate early protein, replication and transcription activator (RTA). Here, we show that viral kinase (ORF36) phosphorylates serines between amino acids 376 and 379 of ORF59 and replacement of the Ser378 residue with alanine significantly impairs phosphorylation. Although mutating these serine residues had no effect on binding between ORF59 and ORF9, viral polymerase, or ORF36, the viral kinase, it significantly reduced the ability of ORF59 to bind to RTA. The results for the mutant in which Ser376 to Ser379 were replaced by alanine showed that both Ser378 and Ser379 contribute to binding to RTA. Additionally, the Ser376, Ser378, and Ser379 residues were found to be critical for binding of ORF59 to oriLyt and its processivity function. Ablation of these phosphorylation sites reduced the production of virion particles, suggesting that phosphorylation is critical for ORF59 activity and viral DNA synthesis.
System of systems information assurance policy: a call for reform

Today’s Department of Defense (DoD) system of system (SoS) programme managers, engineers, and practitioners face significant information assurance (IA) challenges related to the interoperability of their SoS. An IA threat to one system has varying degrees of risk to all the interconnected systems within an enclave or similarly labelled SoS. While current IA policies do address interconnection weaknesses and stipulate that the system with the highest amount of vulnerabilities will be accounted for, current policies, procedures and methods fall short in guidance on how to address the weaknesses beyond the first 1:1 interface in a SoS. The purpose of this paper is to define SoS and to analyse both the fundamental concepts and the latest publications regarding SoS IA policies, procedures and methods. The overall goal is to establish a framework from which the DoD can begin to address the policy reform required to mitigate IA vulnerabilities in modern SoS.
Computer-aided design of optimal structures with uncertainty

Abstract Uncertainties in applied loads are introduced into the theory of optimization by use of ellipsoidal convex models. Mathematical derivations for quantifying uncertainty with the convex model are presented and are incorporated into an optimization computer algorithm. The algorithm is used in two design examples—a continuous two-span reinforced concrete beam and a steel ten-bar truss—with varying levels of uncertainty. Beam and truss designs are obtained under nominal loading, under uncertain loading while employing the convex model, and under uncertain loading using the maximum load condition. The overall cost of the optimal structures is minimized and the resulting designs are compared. The comparisons show that the design costs of the optimal designs produced under the convex model compare favorably to the design costs under nominal loading. However, the design costs associated with the maximum load condition are shown to significantly exceed both the costs associated with nominal loading and the costs associated with the convex model.
The long winter model of Martian biology - A speculation.

A temporal microenvironment model is proposed for Martian biology that is based on an estimated mean thickness of nearly 1 km of frost in the Martian north polar cap summer remnant. If vaporized, this frost could yield not only 1 kg per sq cm of atmosphere, but also higher global temperatures through the greenhouse effect and a greatly increased likelihood of liquid water. Vaporization of such cap remnants may occur twice each equinoctial precession, and Martian organisms may now be in cryptobiotic repose awaiting the end of the long precessional winter. The Viking biology experiments might test this hypothesis.
Solid-Phase Microextraction Measurement of Parent and Alkyl Polycyclic Aromatic Hydrocarbons in Milliliter Sediment Pore Water Samples and Determination of KDOC Values

The U.S. Environmental Protection Agency (EPA) narcosis model for benthic organisms in polycyclic aromatic hydrocarbon (PAH) contaminated sediments requires the measurement of 18 parent PAHs and 16 groups of alkyl PAHs (“34” PAHs) in pore water with desired detection limits as low as nanograms per liter. Solid-phase microextraction (SPME) with gas chromatographic/mass spectrometric (GC/MS) analysis can achieve such detection limits in small water samples, which greatly reduces the quantity of sediment pore water that has to be collected, shipped, stored, and prepared for analysis. Four sediments that ranged from urban background levels (50 mg/kg total “34” PAHs) to highly contaminated (10 000 mg/kg total PAHs) were used to develop SPME methodology for the “34” PAH determinations with only 1.5 mL of pore water per analysis. Pore water was obtained by centrifuging the wet sediment, and alum flocculation was used to remove colloids. Quantitative calibration was simplified by adding 15 two- to six-ring perdeu...
Evaluation of Security Supporting Mechanisms in Cloud Storage

Cloud storage is one of the most promising services of cloud computing. It holds promise for unlimited, scalable, flexible, and low cost data storage. However, security of data stored at the cloud is the main concern that hinders the adoption of cloud storage model. In the literature, there are many proposed mechanisms to improve the security of cloud storage. These proposed mechanisms differ in many aspects and provide different levels of security. In this paper, we evaluate five different mechanisms for supporting the security of the cloud storage. We begin with a brief description of these mechanisms. Then we evaluate these mechanisms based on the following criteria: security, support of writing serializability and reading freshness, workload distribution between the client and cloud, performance, financial cost, support of accountability between the client and cloud, support of file sharing between users, and ease of deployment. The evaluation section of this paper forms a guide for individuals and organizations to select or design an appropriate mechanism that satisfies their requirements for securing cloud storage.
Modeling Peak Oil

"Peak oil" refers to the future decline in world production of crude oil and to the accompanying potentially calamitous effects. The majority of the literature on peak oil is non-economic and ignores price effects even when analyzing policies. Unfortunately, most economic models of depletable resources do not generate production peaks. I present four models which generate production peaks in equilibrium. Production increases in the models are driven by: demand increases, cost reductions through advancing technology, cost reductions through reserve additions, and production capacity increases through site development. Production decreases are driven by scarcity. The models do not rely on market failures and indicate that a peak in production may arise from efficient intertemporal optimization. The models show that prices are a better indicator of impending scarcity than peaking is and that peak production can occur when any percentage from 0-100% of the original deposit remains.
Spectra of van der Waals complexes (dimers) with applications to planetary atmospheres

Spectral features observed in the atmosphere of Titan by the Voyager IR experiment have been attributed to weakly bound complexes of N2 and H2, dominant and minor constituents, respectively. The abundance of H2-N2 dimers there was computed. Current calculations include quantitative spectral line positions and intensities for N2-Ar and CO2-CO2 relating to Titan and Earth, and to Mars and Venus, respectively. This work suggests applications to spectra of planetary atmospheres obtained in spacecraft missions.
The ring closure of substituted azetidinones: a new route to [4.2.0] fused beta-lactams

Abstract The synthesis of 1-carba-1-dethiacephalosporin nuclei is described. The new route utilizes a readily-available penicillin derivative as starting material and features an intramolecular ring closure to form the six-membered ring.
Population equilibria and stability in plant-animal pollination systems

Abstract Differential equation models of the change in population size with change in time have provided valuable insight into nature and have served as tools for management of both predator-prey and competition systems. Presented here is an extension of the differential equation models for application to pollination ecology plant-animal interactions. Analyses define conditions for equilibria and for equilibrium stability for a one-plant one-animal pollinator system. Predictions about plant speciation and pollinator foraging behavior are discussed.
Sleeping together: a pilot study of the effects of shared sleeping on adherence to CPAP treatment in obstructive sleep apnea

Objectives:To examine the sleep of married couples, recorded together in the laboratory before and after the husband is treated with continuous positive airway pressure (CPAP) to control his obstru...
Towards a physiologically based diagnosis of anorexia nervosa and bulimia nervosa

Diagnosis of anorexia nervosa (AN) and bulimia nervosa (BN), while including such physiological data as weight and the reproductive status of the individual, are primarily based on questionnaires and interviews that rely on self-report of both body-related concerns and eating-related behaviors. While some key components of eating disorders are psychological and thus introspective in nature, reliance on self-report for the assessment of eating-related behaviors and nutritional status lacks the objectivity that a physiologically based measure could provide. The development of a more physiologically informed diagnosis for AN and BN would provide a more objective means of diagnosing these disorders, provide a sound physiological basis for diagnosing subclinical disorders and could also aid in monitoring the effectiveness of treatments for these disorders. Empirically supported, physiologically based methods for diagnosing AN and BN are reviewed herein as well as promising physiological measures that may potentially be used in the diagnosis of AN and BN.
Fire hazard and other safety concerns of photovoltaic systems

Photovoltaic (PV) modules are usually considered safe and reliable. But in case of grid-connected PV systems that are becoming popular, the issue of fire safety of PV modules is becoming increasingly important due to the employed high voltages of 600 to 1000 V. The two main factors, i.e., open circuiting of the dc circuit and of the bypass diodes and ground faults that are responsible for the fire in the PV systems, have been discussed in detail along with numerous real life examples. Recommendations are provided for preventing the fire hazards such as designing the PV array mounting system to minimize the chimney effect, having proper bypass and blocking diodes, and interestingly, having an ungrounded PV system.
Ripple effects and oscillations in the broad Fe Kα line as a probe of massive black hole mergers

(abridged) When a sufficiently massive satellite (or secondary) black hole is embedded in a gas disk around a (primary) supermassive black hole, it can open an empty gap in the disk. A gap-opening secondary close to the primary will leave an imprint in the broad component of the FeKa emission line, which varies in a unique and predictable manner. If the gap persists into the innermost disk, the effect consists of a pair of dips in the broad line which ripple blue-ward and red-ward from the line centroid energy respectively, as the gap moves closer to the primary. This ripple effect could be unambiguously detectable and allow an electromagnetic monitoring of massive black hole mergers as they occur. As the mass ratio of the secondary to primary black hole increases to q>0.01, we expect the gap to widen, possibly clearing a central cavity in the inner disk, which shows up in the broad FeKa line component. If the secondary stalls at >100r_{g} in its in-migration, due to low co-rotating gas mass, a detectable ripple effect occurs in the broad line component on the disk viscous timescale as the inner disk drains and the outer disk is dammed. If the secondary maintains an accretion disk within a central cavity, due to dam bursting or leakage, a periodic 'see-saw' oscillation effect is exhibited in the observed line profile. Here we demonstrate the range of ripple effect signatures potentially detectable with Astro-H and IXO/Athena, and oscillation effects potentially detectable with XMM or LOFT for a wide variety of merger and disk conditions. Observations of the ripple effect and periodic oscillations can be used to provide an early warning of gravitational radiation emission from the AGN.
The release of chondroitin sulfate from rabbit cartilage following the intravenous injection of crude papain.

Abstract The intravenous injection of crude papaya latex extract (crude papain) into young rabbits is followed by the appearance, in blood and urine, of a mucopolysaccharide, resembling in chemical and physical properties chondroitin sulfates A and C. The time course of appearance and disappearance correlates well with the gross and histological changes in cartilages of ear and elsewhere. Only a small fraction of the mucopolysaccharide which enters the blood stream is accountable in the urinary excretion. Differences of response in old rabbits have been observed and possible relationships to the process of aging are discussed. The possible activity in crude papaya extract responsible for the observed histological and chemical effects is discussed.