cssi/SciSciGPT-SciSciNet huggingface dataset:
A Semi-distributed Access Control Management Scheme for Securing Cloud Environment

Despite numerous advantages that cloud computing offer (e.g., Flexibility, elasticity, scalability, etc.), many potential clients are still hesitant to join the cloud due to their security and privacy concerns. Outsourcing the data to a cloud in a multitenant environment brings many security challenges including data leaks, threats, and malicious attacks. The cloud computing platform, virtual servers, and the provider's services are highly dynamic and diverse in nature, making the traditional access control mechanisms (e.g., Firewalls and VLAN etc.) less effective in controlling the unauthorized access to cloud's data and resources. Several access control policies and authorization system have been proposed in literature to defend against cloud security threats. Most of these systems are designed to work with one or more access control policies. However, little work has been done to develop generic access control architecture capable to work with most of the available access control policies. In this paper, we present a new access control architecture using a global resource management system (GRMS) to effectively handle both local and remote access requests. The introduction of GRMS makes our proposed architecture semi distributed at the expense of minimal request-response time. In addition, our proposed architecture works effectively with both peered access control module (PACM) and virtual resource manager (VRM) to protect and manage all resources and services of cloud providers from unauthorized access.
Studies on the Regulation of One-Carbon Metabolism II. REPRESSION-DEREPRESSION OF SERINE HYDROXYMETHYLTRANSFERASE BY METHIONINE IN ESCHERICHIA COLI 113-3

Abstract The regulation of serine hydroxymethyltransferase has been investigated in Escherichia coli 113-3 (ATCC 11105). It was found that extracts from bacteria grown in the presence of low levels of methionine (or cyanocobalamin) showed a 2- to 18-fold increase in specific activity over extracts of organisms grown at high concentrations of these compounds. The addition of methionine or S-adenosylmethionine to the serine hydroxymethyltransferase assay mixture had no effect on the specific activity. This provides evidence against regulation via feedback inhibition. It appears that the biosynthesis of this enzyme is controlled by the level of methionine in the growth medium. Dihydrofolate reductase, thymidylate synthetase, and N5,N10-methylenetetrahydrofolate dehydrogenase were not affected by the methionine or cyanocobalamin level. Serine hydroxymethyltransferase was purified 49- to 70-fold from E. coli 113-3 grown in medium containing either low or high levels of methionine. The pH optimum, kinetic constants, and molecular weights were identical for the enzymes from both preparations. The molecular weight of serine hydroxymethyltransferase was found to be 170,000 which differs from that of the enzyme purified from rabbit liver.
Reconceptualizing Trust: An Evolutionary Process Model

The literature has, historically, acknowledged that trust evolves between parties, indicating a dynamic state of affirirs. Yet trust has generally been operationalized as a static state of affairs within the relationship; that is, it either exists or does not exist between partners. One question that has been overlooked is how do the partners in a relationship come to trust one another or fail to trust? Perhaps even more important to an understanding of trust is the question of whether trust itself changes throughout the life of a relationship.
Does ergonomic mismatch at school impact pain in school children

Musculoskeletal pain in school-aged children is highly prevalent. While there are many potential factors relating to this discomfort, one unexplored factor is the ergonomic mismatch. The objective of this study was to determine whether the degree of mismatch between the body dimensions and the classroom furniture was associated with body discomfort. One hundred and thirty-nine children in a Midwestern U.S. school district participated in the study where demographic information, anthropometric measurements, self-reported regional body discomfort, and furniture measurements were collected. The results indicate an extremely high prevalence of ergonomic mismatch. Contrary to what was hypothesized, the ergonomic mismatch was not associated with body discomfort. The lack of association may have been a result of the extremely high prevalence of ergonomic mismatch as well as potential adaptations by the students. Although almost every student was found to not fit their desk and chairs, ergonomic mismatch had limited impact on the body discomfort. It appears that other factors such as backpack weight and time carrying may contribute more to the discomfort of students. However, caution is stress with regard to dismissing ergonomic mismatch factor as a potential risk factor since the extremely high prevalence may have washed out any effect.
Rotational Excitation I: The Quantal Treatment

The quantum-mechanical equations of motion for collision can be solved numerically, at least for rigid rotors, at low enough energy so that only a small number of channels are accessible. Such solutions are expensive and limited to the simplest systems. For practical solutions of collision problems one must resort to various approximations. In recent years a number of excellent approximations for rotational excitation have become available. The approximations to the fully quantal collision problem for rotational scattering are usually based on the time-independent formulation of the problem. The full quantum-mechanical equation for the collision of two rotors given in this chapter serves as a starting point for the various approximations to the quantum-mechanical treatment of rotational energy transfer. The close-coupling equations are of course the most accurate approximation to the collision problem and appear to give answers to any desired accuracy if enough terms are carried in the expansion. The close-coupling equations have the same form as that taken by almost all of the quantal approximations, and as a result the techniques used to solve the close-coupling equations are well suited to solving most systems of coupled second-order differential equations which arise in time-independent quantum scattering problems.
Racial Differences in Macrovascular and Microvascular Function Following Acute Antioxidant Supplementation

Introduction: African Americans (AA) exhibit altered endothelial function compared to Caucasians (CA), possibly due to decrements in nitric oxide bioavailability due to elevated oxidative stress (OS) in AA, suggesting the potential benefit of an antioxidant supplement in reducing OS levels and improving vascular function in AA. Purpose: To determine differences in the responses in forearm blood flow (FBF), peak blood flow following reactive hyperemia (peak FBF), and flow mediated dilation (FMD) between AA and CA with and without antioxidant supplementation. Methods: 20 AA and 25 CA (mean age = 27 years) underwent measures of FBF, peak FBF and FMD following both acute antioxidant (Vitamin C, Vitamin E and alpha lipoic acid) and placebo supplementation in a double blind, randomized, crossover designed study. Results: There were no significant differences between ethnicities in FBF, peak FBF or FMD in the placebo condition. There was a significant interaction between ethnicities in peak FBF following antioxi...
Liver injury with alcoholiclike hyalin after gastroplasty for morbid obesity

Abstract Hepatic damage resembling alcoholic hepatitis has been described after jejunoileal bypass surgery for morbid obesity, but has not been previously reported as a complication of gastric partitioning operations (gastric bypass and gastroplasty). A patient who developed an alcoholic hepatitislike clinical picture 8 mo after gastroplasty is described, suggesting that malnutrition superimposed on obesity may be responsible for the injury in both settings. Reversal of the gastroplasty was associated with clinical and biochemical improvement.
Urothelial carcinoma involving the prostate: the association of revised tumour stage and coexistent bladder cancer with survival after radical cystectomy

Objective To evaluate survival among patients with urothelial carcinoma (UC) within the prostate in order to assess the impact of depth of tumour invasion as well as the importance of a concurrent bladder tumour. Patients and Methods We identified 201 patients who underwent radical cystectomy (RC) between 1980 and 2006 and were found to have UC involving the prostate. All specimens were re-reviewed by a genitourinary pathologist. Survival was estimated using the Kaplan–Meier method and compared with the log-rank test. Cox hazard regression models tested the association of clinicopathological variables with outcome. Results In all, 93 patients had pTis disease in the prostate, 43 had pT2 tumours, and 66 patients were pT4a. The median follow-up was 10.5 years. The 5-year cancer-specific survival for patients with pTis, pT2, and pT4a prostate UC was 73%, 57%, and 21% respectively (P < 0.001). On multivariable analysis, higher prostate tumour stage (hazard ratio [HR] 2.09; P = 0.01), positive lymph node status (HR 2.09; P = 0.002), and concurrent ≥pT3 bladder cancer (HR 4.16; P < 0.001) were significantly associated with an increased risk of death from UC. Conclusions Among patients with prostatic UC involvement, depth of tumour invasion was significantly associated with cancer-specific mortality, validating the staging reclassification. Concurrent locally advanced bladder cancer also negatively impacted survival, suggesting the potential prognostic value of reporting a secondary tumour stage in such cases.
A fully digital hardware detector for pi /4 QPSK

A hardware detector for pi /4 QPSK modulation is described. The digitally adjustable diversity detector integrated circuit (DADD IC) is composed entirely of digital logic circuitry and offers significant size and current drain reductions over conventional DSP-based demodulation techniques. The DADD circuit performs two-branch demodulation with the following key features: post-detection diversity phase combining; long-loop and short-loop frequency control; fast-acquisition decision-directed clock recovery with fade protection, and channel quality estimation. The DADD can be readily configured for various data rates, intermediate frequencies, and reference oscillator frequencies. Moreover, with minor modifications the DADD IC can be used to detect other digitally phase or frequency modulated waveforms. As simulations and bench measurements demonstrate, the DADD IC offers excellent static and faded bit error rate performance for either continuous or burst-mode applications. >
Accumulation of Amikacin in Synovial Fluid After Regional Limb Perfusion of Amikacin Sulfate Alone and in Combination With Ticarcillin/Clavulanate in Horses

Objectives To determine the effect of regional limb perfusion (RLP) with amikacin sulfate alone and in combination with ticarcillin/clavulanate on synovial fluid concentration and antimicrobial activity of amikacin. Sample Population Experimental study. Methods RLP with amikacin alone (A; 2.5 g) or amikacin and ticarcillin/clavulanate (AT; 2.5 g amikacin, 7 g ticarcillin/clavulanate) was performed with a tourniquet placed at mid-antebrachium in standing, sedated horses. Perfusate blood was collected immediately after injection and again before tourniquet release. Blood from the jugular vein was collected before tourniquet release. Synovial fluid from the middle carpal joint was collected 0, 30, and 60 minutes after tourniquet release. Amikacin concentration and antimicrobial activity of synovial fluid against Escherichia coli, Staphylococcus aureus, Klebsiella pneumoniae, and Pseudomonas aeruginosa were determined. Results There was significantly lower amikacin concentration in the middle carpal joint synovial fluid of group AT compared with group A at 30 minutes (AT = median 4.4 µg/mL, IQR 3.0–11.2 µg/mL; A = 17.5 µg/mL, 6.6–80.1 µg/mL) and 60 minutes (AT = median 4.6 µg/mL, IQR 3.1–8.1 µg/mL; A = 15.0 µg/mL, 6.7–61.7 µg/mL) after tourniquet release. Zones of inhibition for ticarcillin-resistant Klebsiella pneumoniae from group AT were significantly smaller than group A from synovial fluid at 30 and 60 minutes after tourniquet release and in the perfusate serum before tourniquet release. Conclusions The combination of amikacin with ticarcillin/clavulanate during RLP resulted in significantly lower amikacin synovial concentration and antimicrobial activity on amikacin susceptible and ticarcillin resistant cultures compared with amikacin alone.
CMOS compatible high-voltage compliant MESFET-based analogue IC building blocks

MESFET devices provide high breakdown characteristics, enable high-voltage operation, and direct battery hook-up with no changes in processing on state-of-the-art SOI and SOS CMOS processes. Fundamental analogue building blocks, including single-ended amplifiers and high impedance current mirrors were designed and fabricated in a single poly, three-layer metal digital CMOS technology utilising depletion mode MESFET devices. The SOS MESFETS presented here have a breakdown voltage of over 7.5 V without causing irreversible damage. DC characteristics were measured by varying the power supply from 2.5 to 5.5 V. The measured DC transfer curves of the amplifier show good agreement with the simulated ones with extracted models from the same process. The accuracy of the current mirror showing inverse operation is within ±5% for the current from 0 to 1.5 mA with the power supply from 2.5 to 5.5 V.
Tpz1-Ccq1 and Tpz1-Poz1 Interactions within Fission Yeast Shelterin Modulate Ccq1 Thr93 Phosphorylation and Telomerase Recruitment

In both fission yeast and humans, the shelterin complex plays central roles in regulation of telomerase recruitment, protection of telomeres against DNA damage response factors, and formation of heterochromatin at telomeres. While shelterin is essential for limiting activation of the DNA damage checkpoint kinases ATR and ATM at telomeres, these kinases are required for stable maintenance of telomeres. In fission yeast, Rad3ATR and Tel1ATM kinases are redundantly required for telomerase recruitment, since Rad3ATR/Tel1ATM-dependent phosphorylation of the shelterin subunit Ccq1 at Thr93 promotes interaction between Ccq1 and the telomerase subunit Est1. However, it remained unclear how protein-protein interactions within the shelterin complex (consisting of Taz1, Rap1, Poz1, Tpz1, Pot1 and Ccq1) contribute to the regulation of Ccq1 Thr93 phosphorylation and telomerase recruitment. In this study, we identify domains and amino acid residues that are critical for mediating Tpz1-Ccq1 and Tpz1-Poz1 interaction within the fission yeast shelterin complex. Using separation of function Tpz1 mutants that maintain Tpz1-Pot1 interaction but specifically disrupt either Tpz1-Ccq1 or Tpz1-Poz1 interaction, we then establish that Tpz1-Ccq1 interaction promotes Ccq1 Thr93 phosphorylation, telomerase recruitment, checkpoint inhibition and telomeric heterochromatin formation. Furthermore, we demonstrate that Tpz1-Poz1 interaction promotes telomere association of Poz1, and loss of Poz1 from telomeres leads to increases in Ccq1 Thr93 phosphorylation and telomerase recruitment, and telomeric heterochromatin formation defect. In addition, our studies establish that Tpz1-Poz1 and Tpz1-Ccq1 interactions redundantly fulfill the essential telomere protection function of the shelterin complex, since simultaneous loss of both interactions caused immediate loss of cell viability for the majority of cells and generation of survivors with circular chromosomes. Based on these findings, we suggest that the negative regulatory function of Tpz1-Poz1 interaction works upstream of Rad3ATR kinase, while Tpz1-Ccq1 interaction works downstream of Rad3ATR kinase to facilitate Ccq1 Thr93 phosphorylation and telomerase recruitment.
The PepT1-NOD2 signaling pathway aggravates induced colitis in mice

Background & Aims The human di/tripeptide transporter human intestinal H-coupled oligonucleotide transporter (hPepT1) is abnormally expressed in colons of patients with inflammatory bowel disease, although its exact role in pathogenesis is unclear. We investigated the contribution of PepT1 to intestinal inflammation in mouse models of colitis and the involvement of the nucleotide-binding oligomerization domain 2 (NOD2) signaling pathway in the pathogenic activity of colonic epithelial hPepT1. Methods Transgenic mice were generated in which hPepT1 expression was regulated by the β-actin or villin promoters; colitis was induced using 2,4,6-trinitrobenzene sulfonic acid (TNBS) or dextran sodium sulfate (DSS) and the inflammatory responses were assessed. The effects of NOD2 deletion in the hPepT1 transgenic mice also was studied to determine the involvement of the PepT1–NOD2 signaling pathway. Results TNBS and DSS induced more severe levels of inflammation in β-actin–hPepT1 transgenic mice than wild-type littermates. Intestinal epithelial cell–specific hPepT1 overexpression in villin-hPepT1 transgenic mice increased the severity of inflammation induced by DSS, but not TNBS. Bone marrow transplantation studies showed that hPepT1 expression in intestinal epithelial cells and immune cells has an important role in the proinflammatory response. Antibiotics abolished the effect of hPepT1 overexpression on the inflammatory response in DSS-induced colitis in β-actin–hPepT1 and villin-hPepT1 transgenic mice, indicating that commensal bacteria are required to aggravate intestinal inflammation. Nod2 −/−, β-actin–hPepT1 transgenic/ Nod2 −/−, and villin-hPepT1 transgenic/ Nod2 −/− littermates had similar levels of susceptibility to DSS-induced colitis, indicating that hPepT1 overexpression increased intestinal inflammation in a NOD2-dependent manner. Conclusions The PepT1–NOD2 signaling pathway is involved in aggravation of DSS-induced colitis in mice.
Comparative Pharmacokinetics and Metabolism of Cephapirin in Laboratory Animals and Humans

Abstract Comparative drug disposition studies in mice, rats, dogs, and humans indicate that cephapirin, a new semisynthetic cephalosporin antibiotic that exhibits broad-spectrum antimicrobial activity, is metabolized to desacetylcephapirin in these species. Pharmacokinetic analyses of the concentrations of cephapirin and desacetylcephapirin in plasma and urine reveal that the rate and extent of deacetylation decreases from rodents to dogs to humans. The kinetic analyses also suggest that the kidney performs a role not only in the excretion but also in the metabolism of cephapirin to desacetylcephapirin.
All-organic and organic-silicon photonic ring micro-resonators

Organic electro-optic materials offer exceptional processability (both from solution and the gas phase) that permit fabrication of flexible and conformal device structures and the integration of organic materials with a wide range of disparate materials. In addition, organic electro-optical materials have fundamental response times that are in the terahertz region, and useable electro-optic coefficients that are approaching 300 pm/V (at telecommunication wavelengths). In addition to fabrication by traditional lithographic methods, multiple devices on a single wafer have been fabricated by soft and nano-imprint lithography. In this presentation, we review the fabrication and performance evaluation of a number of all-organic and organic-silicon photonic ring microresonator devices. Both electrical and thermal tuning of devices, including both single and multiple ring micro-resonators, are demonstrated.
The management of flail chest.

Flail chest is an uncommon consequence of blunt trauma. It usually occurs in the setting of a high-speed motor vehicle crash and can carry a high morbidity and mortality. The outcome of flail chest injury is a function of associated injuries. Isolated flail chest may be successfully managed with aggressive pulmonary toilet including facemask oxygen, continuous positive airway pressure, and chest physiotherapy. Surgical stabilization is associated with a faster ventilator wean, shorter ICU time, less hospital cost, and recovery of pulmonary function in a select group of patients with flail chest. There is no role for stabilization for patients who have severe pulmonary contusion. Supportive therapy and pneumatic stabilization is the recommended approach for this patient subset.
Chemosensory Alteration of Information Processinga

: Previous research has found both facilitation and interference when odors are administered during the performance of cognitive tasks. The present research was designed to investigate the possibility that odors might differentially effect different varieties of cognitive tasks. Twelve subjects performed matched verbal, numeric, and spatial tasks as event-related potentials were measured. Odors and tones were introduced as subjects completed the tasks in a paradigm optimized to produce disruption of performance. Results indicated that P300 amplitude to the task stimuli depended upon the type of task and the modality of the distractor. P300 amplitude was relatively consistent across tasks for the tone distractor. During the olfactory distractor, P300 amplitude was greater for the symbolic stimuli (verbal and numeric) and lower for the spatial. Reaction times to the various tasks did not differ as a function of the modality of the distractor.
Friction and wear of carbon-graphite materials against metal and ceramic counterfaces

Abstract The unlubricated and lubricated sliding friction and wear behaviour of eleven commercially produced carbon-graphite (CG) materials were evaluated as part of an effort to identify promising tribomaterials for use as piston-wrist couples in energy-efficient, low-emission automotive and truck engines. Graphite has a low density and thus the potential to reduce engine weight and enhance efficiency. The CG materials varied in composition, density and mechanical properties. All eleven grades of CG materials were tested in ball-on-flat reciprocating sliding against M-50 tool steel and NBD 100 silicon nitride spheres under unlubricated conditions. In addition, six of the grades were tested under both hot oil-lubricated conditions and abrasive dust-contaminated hot oil. The friction of all compositions was greatly reduced by lubrication, but wear was significantly increased in almost all cases. Interestingly, the introduction of abrasive mineral dust into the lubricant slightly reduced the friction coefficients and the wear rates of the materials tested. Wear of the counterface materials was generally too small to measure or was obscured by adherent transfer. Two CG compositions experienced mild-to-severe wear transitions in the unlubricated tests, but lubrication with hot oil tended to suppress those transitions.
Extending the Concurrent Validity of the Self-Injurious Thoughts and Behaviors Interview to Inpatient Adolescents

The Self-Injurious Thoughts and Behaviors Interview (SITBI) was created to address limitations in existing suicide assessments and its validity was evaluated in the original publication. However, this work has not yet been extended to inpatient adolescents, a population in which suicide assessment is crucial. Moreover, information on the psychometric properties of the SITBI has not been provided by other groups beyond the developers of the SITBI. The aim of this study was to examine the concurrent validity of the suicide ideation, attempt, plan, and gesture modules of the SITBI with inpatient adolescents (N = 106, 64.8 % female, M age = 14.63), as an extension to previous validation efforts using this measure. Concurrent validity was examined with established interview-based and self-report measures of suicide ideation and suicide intent. The SITBI demonstrated adequate agreement with other measures, suggesting adequate validity for the suicide ideation, attempt, plan, and gesture modules in a sample of inpatient adolescents.
HSV carrying WT REST establishes latency but reactivates only if the synthesis of REST is suppressed

HSVs transit from vigorous replication at the portal of entry into the body to a latent state in sensory neurons in which only noncoding (e.g., latency-associated transcript) and micro-RNAs are expressed. In productive infection, viral genes must be sequentially derepressed at two checkpoints. A leading role in the repression of viral genes is carried out by histone deacetylase (HDAC)/corepressor element-1 silencing transcription factor (CoREST)/lysinespecific demethylase1(LSD1)/RE1-silencing transcription factor (REST) repressor complex (HCLR). Previously, we reported that to define the role of the components of the HCLR complex in the establishment of latency, we constructed recombinant virus (R112) carrying a dominant-negative REST that bound response elements in DNA but could not recruit repressive proteins. This recombinant virus was unable to establish latency. In the current studies, we constructed a virus (R111) carrying WT REST with a WT genome. We report the following findings: (a) R111 readily established latent infection in trigeminal ganglia; however, although the amounts of viral DNAs in latently infected neurons were similar to those of WT virus, the levels of latency-associated transcript and micro-RNAs were 50- to 100-fold lower; (b) R111 did not spontaneously reactivate in ganglionic organ cultures; however, viral genes were expressed if the synthesis of REST was blocked by cycloheximide; and (c) histone deacetylase inhibitors reactivated the WT parent but not the R111 recombinant virus. The results suggest that REST plays a transient role in the establishment of latency but not in reactivation and suggest the existence of at least two phases at both establishment and reactivation.
Longitudinal and depth variation of bacterioplankton productivity and related factors in a temperate estuary

Abstract Bacterioplankton productivity (BP) spatial variation was investigated in relation to potential resources, including primary productivity and dissolved organic matter, in the micro-tidal Neuse River–Pamlico Sound estuarine system, North Carolina, USA. Estuarine BP was predicted to correlate with the trophic gradient, decreasing along the salinity gradient in parallel with the decrease in organic matter and primary productivity. This prediction was tested over four years at spatial scales ranging from kilometers to meters along the riverine axis and with depth. The general pattern of BP across the salinity gradient was unimodal and matched the phytoplankton patterns in peak location and variability. Peak locations varied with discharge, especially in 2003 when above average discharge moved peaks downstream. Spatial coherence of BP with other variables was much less at short time scales. The effect of temperature, nutrients, and phytoplankton on BP varied by location, especially fresh versus brackish stations, although only temperature explained more than 20% of the BP variation. Depth variation of BP was as great as longitudinal variation and bottom samples were often higher than surface. BP was strongly correlated with particulate organic carbon at the pycnocline and bottom, highlighting the importance of particulate matter as a resource. Station-averaged BP and phytoplankton data corresponded well with two published meta-analyses, although the offset of the freshwater station suggested longitudinal differences in community composition or resource availability.
Has the Security and Exchange Commission’s Rule 421 made mutual fund prospectuses more accessible?

A mutual fund must provide prospectuses to each potential investor before the fund may accept monies from that individual. The prospectuses are a major source of information about the fund and yet they have historically been largely unreadable by the public. While the poor readability has been a problem in the past, it is becoming a greater problem as the number of individuals responsible for their own investment decision making increases. Recognising this problem, the Securities and Exchange Commission (SEC) adopted Rule 421 in 1998, requiring that prospectuses be made more readable as measured by a subjective reading of the document. This study applies four objective tests to mutual fund prospectuses from both preand post‐Rule 421 periods and finds substantial evidence that mutual fund companies have complied with Rule 421 and are producing prospectuses that are much more readable and accessible by the general public.
Characteristics of Ignition Transistors

The factors which enter into the selection of a transistor ignition switch are considered. Along with this, the benefits to be gained from transistor switching are reviewed. Among other things, frequent adjustment is rendered unnecessary and the output voltage of the coil does not fall off at high engine speed.
Outcome of fetuses with lactic acidemia

Umbilical arterial lactate, pH, PO 2 , PCO 2 , and base deficit were measured at delivery of 468 live-born infants. The correlation between the 1-minute Apgar score and lactate (r = −0.34) was comparable to that between the 1-minute Apgar score and pH (r = 0.30). The multiple correlation coefficient between the 1-minute Apgar score and all five parameters combined (lactate, pH, PO 2 , PCO 2 , and base deficit) was 0.36. This was not significantly higher than the simple correlation coefficient for pH alone (0.30). Similar correlation coefficients were noted for the 5-minute Apgar score. The dividing point between normal and pathologic lactate levels was 3.70 mmol/L. A pH
Inactivation and dissociation of β-galactosidase by amines

Abstract In addition to the inactivation and partial dissociation of β-galactosidase by mercaptoethanol, mercaptoethylamine or dithiothreitol, we found that ethanolamine or ethylenediamine rapidly inactivates the enzyme and causes quantitative dissociation of the 16S tetramer to a single 6S component. These results suggest that the thiol function of mercaptoethanol or mercaptoethylamine may be acting primarily as an electron donor in chelation rather than as a disulfide reducing agent.
Enzyme-modulated cleavage of dsDNA for supramolecular design of biosensors.

Supramolecular docking and immobilization of biotinylated dsDNA onto a self-assembled monolayer of avidin have been measured using impedance spectroscopy and quartz crystal microbalance technique. The formation of the serial assembly was first achieved by linearizing circular plasmid dsDNA using BamH I endonuclease enzyme. This was followed by a bisulfite-catalyzed transamination reaction in order to biotinylate the dsDNA. The reaction is single-strand specific, and it specifically targets unpaired cytosine bases generated during the enzyme cleavage. The biotinylated dsDNA was then used as a ligand at a gold electrode containing avidin. The process was monitored by ac impedance spectroscopy that was used to probe the changes in interfacial electron-transfer resistance upon binding and a microgravimetric quartz crystal microbalance that reflected in situ mass changes on the dsDNA-functionalized substrates. Our results demonstrated that this approach could be employed for the determination of small-molecula...
Differentiation and degeneration of cells that play a major role in tobacco anther dehiscence

Dehiscence is the terminal step in anther development that releases pollen grains from the wall of each theca at a specific site between the two locules. In tobacco, two groups of cells—the circular cell cluster and the stomium—are required for anther dehiscence and define the position at which pollen is released. The processes responsible for the differentiation of the circular cell cluster and the stomium from cells in specific anther regions are unknown. Nor is it understood what initiates the programmed degeneration of these cell types that ultimately is responsible for pollen release from the anther. We characterized stomium and circular cell cluster differentiation and degeneration using both light and transmission electron microscopy throughout anther development, from the emergence of stamen primordia to anther dehiscence at flower opening. We observed that histological changes within primordium L1 and L2 cells destined to become the stomium and circular cell cluster occur at the same time after the differentiation of surrounding locule regions. Sub-epidermal cells that differentiate into the circular cell cluster divide, enlarge, and generate vacuoles with calcium oxalate crystals prior to any detectable changes in pre-stomium epidermal cells. Differentiation and division of cells that generate the stomium occur after cell degeneration initiates in the circular cell cluster. Prior to dehiscence, the stomium consists of a small set of cytoplasmically dense cells that are easily distinguished from their larger, highly vacuolate epidermal neighbors. Plasmodesmata connections within and between cells of the stomium and circular cell cluster were observed at different developmental stages, suggesting that these cells communicate with each other. Circular cell cluster and stomium cell death is programmed developmentally and occurs at different times. Degeneration of the circular cell cluster occurs first, contributes to the formation of a bilocular anther, and generates the site of anther wall breakage. The stomium cell death process is complete at flower opening and provides an opening for pollen release from each theca. We used laser capture microdissection and real-time quantitative reverse-transcription polymerase chain reactions to demonstrate that stomium cells can be isolated from developing anthers and studied for the presence of specific mRNAs. Our data suggest that a cascade of unique gene expression events throughout anther development is required for the dehiscence program, and that the differentiation of the stomium and circular cell cluster in the interlocular region of the anther probably involves cell signaling processes.
Determination and occurrence of AHH-active polychlorinated biphenyls, 2,3,7,8-tetrachloro-p-dioxin and 2,3,7,8-tetrachlorodibenzofuran in Lake Michigan sediment and biota. The question of their relative toxicological significance

Abstract An analytical procedure has been developed for the determination of the 18 PCB congeners which are inducers of methylcholanthrene-like mixed function oxidase activity in animals and include the most toxic PCBs. Determinations of the toxic PCB congeners in samples of eggs of predatory fish and piscivorous birds of the Great Lakes and in Aroclor mixtures demonstrate that the apparent toxic potency of PCB residues in these samples is dominated by two congeners, 3,3′,4,4′,5- and 2,3,3′,4,4′-pentachlorobiphenyl. Furthermore, the analyses demonstrate that the potential toxicity of PCB residues can increase 5 to 10 fold as they reach upper levels of aquatic food chains and most often exceed the potential toxicity of chlorinated dibenzodioxins and furans in higher animals even in environments highly contaminated by the latter compounds.
Persian Historiography, Vol. X of A History of Persian Literature by Charles Melville (ed.)

Chronicles produced in the orbit of the rulers of Iran and the wider Persianate world are the indispensable, and at times the only available, written sources for the history of that part of the wor...
The taxol pathway 10-O-acetyltransferase shows regioselective promiscuity with the oxetane hydroxyl of 4-deacetyltaxanes

The 10-deacetylbaccatin III:10beta-O-acetyltransferase isolated from Taxus cuspidata regiospecifically transfers short-chain alkanoyl groups from their corresponding CoA thioesters to the C10 hydroxyl of 10-deacetylbaccatin III. This 10-O-acetyltransferase along with five other Taxus acyltransferases on the paclitaxel (Taxol) biosynthetic pathway and one additional Taxus-derived acyltransferases of unknown function were screened for 4-O-acetyltransferase activity against 4-deacetylbaccatin III, 7-acetyl-, 13-acetyl-, and 7,13-diacetyl-4-deacetylbaccatin III. These 4-deacyl derivatives were semisynthesized from the natural product baccatin III via silyl protecting group manipulation, regioselective reductive ester cleavage with sodium bis(2-methoxyethoxy)aluminum hydride, and regioselective acetylation with acetic anhydride. Assays with the 4-deacetylated diterpene substrates and acetyl CoA revealed the taxane 10beta-O-acetyltransferase was able to catalyze the 4-O-acetylation of 4-deacetylbaccatin III to baccatin III and 13-acetyl-4-deacetylbacatin III to 13-acetylbaccatin III, although each was converted at lesser efficiency than with the natural substrate. In contrast, this enzyme was unable to acetylate 7-acetyl-4-deacetylbaccatin III and 7,13-diacetyl-4-deacetylbaccatin III substrates at C4, suggesting that the C7 hydroxyl of baccatin III must remain deacylated for enzyme function. The biocatalytic transfer of an acyl group to the tertiary hydroxyl on the oxetane moiety at C4 of the taxane ring demonstrates that the regiochemistry of the 10beta-acetyltransferase is mutable.
Analytical performance study of solar blind non-line-of-sight ultraviolet short-range communication links.

Motivated by recent advances in solid-state incoherent ultraviolet sources and solar blind detectors, we study communication link performance over a range of less than 1 km with a bit error rate (BER) below 10−3 in solar blind non-line-of-sight situation. The widely adopted yet complex single scattering channel model is significantly simplified by means of a closed-form expression for tractable analysis. Path loss is given as a function of transceiver geometry as well as atmospheric scattering and attenuation and is compared with experimental data for model validation. The BER performance of a shot-noise-limited receiver under this channel model is demonstrated.
On the Scale of the Nonlinear Effect in a Crack Problem

When crack problems are analyzed on the basis of nonlinear theories, such as finite elasticity or deformation theory of plasticity, it is inevitable that nonlinear effects will predominate near a crack-tip, even if the loads are small. The most favorable circumstance in this regard occurs when the loads are so small that the zone of significant nonlinearity lies within the region of validity of the near-tip approximation to the global solution of the associated linearized crack problem. This situation - called small-scale yielding for crack problems in plasticity - permits simplifications in analysis which are often decisive; see, e.g., Knowles (1977) and Rice (1968). Insofar as we know, there are no analytical estimates available of the level of load below which nonlinear effects are guaranteed to be small-scale in the above sense. Indeed, even a precise version of the question seems to be lacking. In the present note we formulate and answer such a question for an especially cooperative crack problem; that corresponding to finite anti-plane shear of an infinite medium containing a crack of finite length for an elastic material of Neo-Hookean type. The associated boundary value problem is a linear one for Laplace's equation and thus can be solved globally. Nevertheless, there is a significant nonlinear effect of Kelvin type in the stress field. We give a condition under which this nonlinear response occurs on a small scale near the crack tips.
Women in academia.

Although our study was conducted in only one physical science discipline, and although most of the individual tests did not yield statistically significant differences, the data consistently yielded a trend in the direction of the existence of discrimination against women in academia. This leads us to the tentative conclusion that when two equally qualified applicants are being considered for an academic position, a male would be chosen over a female. However, a woman with clearly superior qualifications, in competition with an average man, is likely to be recognized. The bias seems to hold especially for higher-quality schools, in departments with younger and newer chairmen, and for chairmen from schools located in the eastern and western parts of the country. The underutilization of potentially qualified women in science represents lost opportunities to society and to science in terms of the overall goal of advancing science. To the extent that the bias reflects strongly held cultural norms, change will come slowly. However, structural changes within the institutions that employ and train women scientists may be achieved sooner through the active intervention of outside agencies, for example, the enforcement by the Department of Health, Education, and Welfare of the Equal Opportunities Act in colleges and universities ( 19 ). In addition, such federal grant-awarding agencies as the National Science Foundation and the National Institutes of Health could be given a mandate to make a special effort to identify and award grants and other forms of recognition to deserving women scientist.
Global style momentum

Abstract We first document the empirical regularity of significant style-level momentum returns in international data. Then we test some Barberis and Shleifer (2003) propositions regarding style momentum. One proposition holds that Sharpe ratios from style-level momentum strategies should be at least as large as stock-level momentum Sharpe ratios. We test for style-level momentum profitability in our sample of global markets and find some evidence of larger style momentum Sharpe ratios, especially within the value-growth style. However, most of the evidence favors stock momentum. The Barberis and Shleifer (2003) model also suggests that style momentum could be time-varying. Variables that effectively condition stock momentum are much less effective with style momentum.
Gingival fibrous nodule

Five patients with small, exophytic, asymptomatic fibrous nodules, single or multiple, of the mandibular mucogingival zone of the anterior labial gingiva are presented. Such nodules are benign and resemble small fibromas. The clinical and histologic appearance distinguishes them from entities such as retrocuspid papilla, reticular mandibular gingival ridges, oral hamartomas associated with Cowden's syndrome, tuberous sclerosis oral lesions, and oral nodules secondary to epidermolysis bullosa. Gingival fibrous nodule, or gingival nodule, is the proposed name for this lesion, which is essentially a variation of normal oral structures that may be mistaken for disease.
Role of NHE3 in Mediating Renal Brush Border Na+-H+ Exchange ADAPTATION TO METABOLIC ACIDOSIS

The aims of the present study were to estimate the fraction of renal brush border membrane Na+-H+ exchange activity mediated by the isoform NHE3 and to evaluate whether the increased brush border Na+-H+ exchange observed in metabolic acidosis is due to increased expression of NHE3 protein. Compared with other isoforms, NHE3 is known to have a unique profile of sensitivity to pharmacologic inhibitors, including relative resistance to amiloride analogs and HOE694. We therefore assessed the inhibitor sensitivity of pH gradient-stimulated 22Na uptake in renal brush border vesicles isolated from normal rats. The I50 values for amiloride (30 μM), dimethylamiloride (10 μM), ethylisopropylamiloride (6 μM), and HOE694 (>100 μM) were markedly dissimilar from those reported for NHE1 and NHE2 but were nearly identical to reported values for NHE3. Na+-H+ exchange activity in renal brush border vesicles isolated from rats with 5 days of NH4Cl-induced metabolic acidosis was increased 1.5-fold compared with control rats, with no change in inhibitor sensitivity. Western blot analysis indicated that NHE3 protein expression was greater in brush border membranes from acidotic compared with control rats. We conclude that virtually all measured Na+-H+ exchange activity in brush border membranes from control and acidotic rats is mediated by NHE3 and that metabolic acidosis causes increased expression of renal brush border NHE3 protein.
Use of color Doppler flow imaging for preoperative assessment in fibular osteoseptocutaneous free tissue transfer

Fibular osteocutaneous free tissue transfer represents state-of-the-art reconstruction of the oromandibular complex after oncologic resection. Because the blood supply of the fibular flap is based on the peroneal artery and venae comitantes, it is essential to determine preoperatively whether adequate perfusion to the donor extremity will persist after sacrifice of the peroneal pedicle. Vascular variations or peripheral arterial occlusive disease may exist whereby sacrifice of peroneal vessels can cause ischemia of the lower leg and foot. Therefore, angiography of the lower extremity and magnetic resonance angiography have been advocated to determine the arterial supply to the lower leg. Though accurate, these examinations carry risk for morbidity, and both are expensive. Color Doppler flow imaging is a noninvasive ultrasound examination used to measure antegrade and retrograde blood flow. We prospectively evaluated color Doppler flow imaging as a means of preoperative evaluation of the lower extremity for candidates for fibular flaps. Ability to image peroneal vessels and to determine collateral and distal perfusion were evaluated. The patients were compared with a control group of patients with peripheral arterial occlusive disease. Color Doppler flow imaging provided accurate hemodynamic information for all patients and allowed successful fibular transfer for all patients who received free flaps. The modality is comparable in accuracy with the angiography of the lower extremity and magnetic resonance angiography and has the advantages of low cost and no morbidity.
Semantically- and phonologically-related primes improve name retrieval in young and older adults

Word and name retrieval failures increase with age, and this study investigated how priming impacts young and older adults' ability to produce proper names. The transmission deficit hypothesis predicts facilitation from related prime names, whereas the blocking and inhibition deficit hypotheses predict interference from related names, especially for older adults. On half of our experimental trials, we exposed participants to a prime name that is phonologically and semantically related to a target name. Related names facilitated production of targets overall, with older adults' naming ability improved at least as much as young adults'. Results are contrary to predictions of the blocking and inhibitory deficit hypotheses, and suggest that an activation-based model of memory and language better accounts for retrieval and production of well-known names.