cssi/SciSciGPT-SciSciNet huggingface dataset:
O-methylhydroxylamine as a reagent for NAD+ modification in urocanase.

Abstract The inhibition of urocanase from Pseudomonas putida by O -methylhydroxylamine has been characterized as being due to the formation of an adduct between CH 3 ONH 2 and NAD + , the latter of which has been recently shown to be a tightly bound coenzyme for this urocanase. Inhibition is maximal at pH 8.5 and is blocked by the presence of the substrate analog imidazole propionate. Loss of catalytic activity corresponds directly with the binding of 1 mol of 14 CH 3 ONH 2 per mole of enzyme, and partial reversibility of the modification, achieved by dialysis at pH 7.5, is accompanied by concomitant restoration of enzymatic activity. No incorporation of 14 CH 3 ONH 2 into urocanase is seen when enzyme-bound NAD + is first converted to NADH or when NAD + is removed by prior treatment of urocanase with 8 m urea. Stability and spectral properties of the CH 3 ONH · NAD adduct are consistent with previous data reported for the product of the hydroxylamine reaction with NAD + . It is concluded that other urocanases which exhibit inhibition by hydroxylamine may likewise contain NAD + as an essential coenzyme and that the use of 14 CH 3 ONH 2 as a reversible modification reagent for NAD + should prove helpful for studies on the role of NAD + in the urocanase catalytic process.
A comparison of enzyme preparations to liberate folic acid for the microbiological assay of feed ingredients

Microbiological assays were conducted to determine the level of total folate in feed ingredients using Lactobacillus casei (ATCC 7469). Fifty-seven samples of feedstuffs were collected from several locations in the southeastern USA by a major broiler producer. Folic acid contents of samples pretreated before assay with three enzymes (conjugase, α-amylase, a mixture of protease (Pronase®, were 22±86 ± 1.99 (μg per 100 g ± SD) for corn (N = 14), 22±01 + 1.18 for fish meal (N = 7), 29.34 ± 0.55 for milo (N = 4), 25.80 ± 6.93 for bakery meal (N = 5), 56.76 ± 4.97 for meat and bone meal (N = 4), 85.14 ± 2.56 for wheat middlings (N = 5), and 193.97 ± 11.19 for soybean meal (N = 18). Predigestion with conjugase, α-amylase and Pronase® liberated folic acid and increased values by 22.3% compared to conjugase predigestion alone (P≤0.05). This study shows that the traditional conjugase pretreatment does not completely free folate from complex feed ingredients for microbiological analysis.
Effect of α-tocopherol deficiency on indices of oxidative stress in normal and diabetic peripheral nerve

Abstract We tested the hypothesis that oxidative stress can cause neuropathy by evaluating the effect of α-tocopherol depletion in normal and streptozotocin (STZ) diabetic peripheral nerve (known to be subject to oxidative stress). The end points were nerve electrophysiology and indices of oxidative stress. Studies were done on 6 groups of rats at 1 and 3 months: (1) Controls, normal α-tocopherol (Con[N]). (2) Controls, α-tocopherol-deficient (Con[−]) (3) Controls, α-tocopherol supplemented (Con[+]); (4) Diabetic, normal α-tocopherol (STZ[N]); (5) Diabetic, α-tocopherol-deficient (STZ[−]) (6) Diabetic, α-tocopherol supplemented (STZ[+]). An α-tocopherol-deficient diet resulted in a rapid depletion of the vitamin in plasma and sympathetic neurones (superior cervical ganglion), and a slower depletion in sensory neurones (dorsal root ganglion) and nerve. The depletion was associated with a reduction in reduced glutathione and an increase in conjugated dienes and hydroperoxides in normal rats, and resulted in similar changes, or accentuated the abnormalities, in diabetic nerves. Changes were more pronounced at 1 than 3 months and α-tocopherol supplementation, for the most part, did not prevent the abnormalities. α-Tocopherol depletion induced or worsened nerve conduction abnormalities in both sciatic-tibial and caudal nerves. Sensory fibers were more affected than motor fibers and the changes were more pronounced at 3 than 1 month. These findings support the notion that oxidative stress may cause neuropathy and that it might be mechanistically implicated in experimental diabetic neuropathy (STZ-EDN).
A New Algorithm for Computing Correlations

In this correspondence we present a new algorithm for computing the correlation [mi][/mi]. For applications where the "cost" of a multiplication is greater than that of an addition, the new algorithm is always more computationally efficient than direct evaluation of the correlation, and it is generally more efficient than FFT methods for processing 128 or fewer data points, or for calculating only the first L values of Rk, for L < 10 log2 2N.
Neurophysiologic evidence for a central sensitization in patients with fibromyalgia.

Objective To determine whether abnormalities of peripheral and central nociceptive sensory input processing exist outside areas of spontaneous pain in patients with fibromyalgia (FM) as compared with controls, by using quantitative sensory testing (QST) and a neurophysiologic paradigm independent from subjective reports. Methods A total of 164 outpatients with FM who were attending a self-management program were invited to participate in the study. Data for 85 patients were available and were compared with those for 40 non-FM controls matched for age and sex. QST was performed using thermal, mechanical, and electrical stimuli at locations of nonspontaneous pain. Pain assessment was 2-fold and included use of subjective scales and the spinal nociceptive flexion reflex (NFR), a specific physiologic correlate for the objective evaluation of central nociceptive pathways. Questionnaires regarding quality of life and the impact of FM were available. Results Participants were mainly middle-aged women, with a mean disease duration of 8 years. Between-group differences were significant for neurophysiologic, clinical, and quality of life measures. In patients with FM, peripheral QST showed significantly altered cold and heat pain thresholds, and tolerance to cold pain was radically reduced. The median NFR threshold in patients with FM (22.7 mA [range 17.5–31.7]) was significantly decreased compared with that in controls (33 mA [range 28.1–41]). A cutoff value of <27.6 mA for NFR provided sensitivity of 73% and specificity of 80% for detecting central allodynia in the setting of FM. Conclusion Our results strongly, although indirectly, point to a state of central hyperexcitability of the nociceptive system in patients with FM. The NFR can be used to assess central allodynia in FM. It may also help discriminate patients who may benefit from use of centrally acting analgesics.
Characterization of an explosively bonded aluminum proton beam window for the Spallation Neutron Source

Abstract An effort is underway at the Spallation Neutron Source (SNS) to redesign the 1st Generation high-nickel alloy proton beam window (PBW) to a 2nd Generation design that utilizes aluminum for the window material. One of the key challenges to implementation of an aluminum PBW at the SNS was selection of an appropriate joining method to bond an aluminum window to the stainless steel shielding structure of the PBW assembly. An explosively formed bond was selected as the most promising joining method for the aluminum PBW design and a testing campaign was conducted to evaluate the strength and efficacy of explosively formed bonds that were produced using two different interlayer materials: niobium and titanium. The characterization methods reported here include tensile testing, thermal-shock leak testing, optical microscopy, and advanced scanning electron microscopy. All tensile specimens examined failed in an aluminum interlayer and measured tensile strengths were all slightly greater than the native properties of the aluminum interlayer, while elongation values were all slightly lower. A leak developed in the test vessel with an niobium interlayer after repeated thermal-shock cycles, which was attributed to an extensive crack network that formed in an interfacial layer of a niobium-rich constituent phase located on the bond interfaces of the niobium interlayer; the test vessel with a titanium interlayer did not develop a leak under the conditions tested. Due to the experience gained from these characterizations, an explosively formed bond with a titanium interlayer was selected for the aluminum PBW design at the SNS.
Switched Reluctance Generator Control for Optimal Power Generation With Current Regulation

This paper presents a novel method of controlling switched reluctance generators (SRGs) for maximum efficiency with active current regulation. The effect of varying the input control parameters on the efficiency of the SRG is first analyzed through exhaustive data collection through simulation and experiments. The analysis of the collected data showed that the input control parameters that minimize the dc-link current ripple also maximize the generating efficiency. A novel control strategy based on the analysis is then developed to maximize the efficiency indirectly through the control parameters that minimize the dc-link current ripple in real time while delivering the commanded generation power. The controller algorithm has been implemented with a 1-kW experimental three-phase SRG drive system charging a NiMH battery pack.
Beliefs and attitudes of urban primary teachers toward physical science and teaching physical science

Eighteen primary teachers (K-3) from five urban schools in the southeastern part of the United States participated in this study. The purposes of this study were to provide insight into options for inservice education programs dealing with urban teachers and their unique needs and to determine some of the attitudes and beliefs of urban primary school teachers toward physical science and physical science teaching. The results of this study indicated that these elementary teachers realized the importance of hands-on activities. However, they felt a need for a stronger knowledge of chemistry and physics to competently teach elementary physical science using that instructional strategy. There were significantly positive relationships between their attitudes and beliefs about physical science.
ON THE MOMENTUM OF POPULATION GROWTH

If age-specific birth rates drop immediately to the level of bare replacement the ultimate stationary number of a population will be given by (9): $$\left( {{\textstyle{{b\mathop e\limits^ \bullet {}_0} \over {r\mu }}}} \right)\left( {\frac{{R_0 - 1}}{{R_0 }}} \right)$$ multiplied by the present number, where b is the birth rate, r the rate of increase, $$\mathop e\limits^ \bullet _0 $$ the expectation of life, and R 0 the Net Reproduction Rate, all before the drop in fertility, and μ the mean age of childbearing afterwards. This expression is derived in the first place for females on the stable assumption; extension to both sexes is provided, and comparison with real populations shows the numerical error to be small where fertility has not yet started to drop. The result (9) tells how the lower limit of the ultimate population depends on parameters of the existing population, and for values typical of underdeveloped countries works out to about 1. 6. If a delay of 15 years occurs before the drop of the birth rate to replacement the population will multiply by over 2. 5 before attaining stationarity. The ultimate population actually reached will be higher insofar as death rates continue to improve. If stability cannot be assumed the ultimate stationary population is provided by the more general expression (7), which is still easier to calculate than a detailed projection.
Trisomy 10p: Report of an unusual mechanism of formation and critical evaluation of the clinical phenotype

A de novo tandem inverted duplication of 10p was diagnosed in a 17-week fetus. The appearance of GTG banded preparations and the results of fluorescence in situ hybridization (FISH) studies are consistent with duplication of the entire arm, including the telomere. The FISH studies also demonstrated the presence of chromosome 10 alphoid repeats at the junction between the inverted segment and the long arm, consistent with the presence of the entire long arm of the abnormal chromosome. Therefore, this is a case of pure trisomy 10p without an associated deficiency of any other chromosome segment. A comparison of the phenotype associated with pure trisomy 10p and trisomy associated with a duplication/deficiency state documented a higher frequency (of borderline significance) of clubfoot and high-arched/cleft palate in the cases of pure trisomy. The frequency of palatal anomalies was observed to be significantly higher in the cases where the breakpoint of the trisomic segment is in the most proximal band (10p11). However, other clinical manifestations were observed inconsistently, even in the cases with pure, nearly complete trisomy 10p. Therefore, a clearly defined trisomy 10p clinical syndrome could not be documented in this study.
Duration of illness and structure of symptoms in schizophrenia.

Background. Previous research has mainly focused on the cross-sectional structure of symptoms in schizophrenia. This meta-analysis examined the association of duration of illness with the structure of symptoms. Methods. Using explicit criteria, 22 studies reporting on the correlations of symptoms in 2665 schizophrenic patients were selected. From each study, symptom-pair correlations for negative symptoms as rated by Scale for the Assessment of Negative Symptoms (SANS) and positive symptoms as rated by the Scale for the Assessment of Positive Symptoms (SAPS) were extracted. Variability among symptom-pair correlations across studies was assessed using tests of homogeneity. For symptom-pair correlations which were not found to be homogeneous, the association of average duration of illness with the symptom-pair correlations were examined. Results. There was considerable variability in symptom-pair correlations across studies. Part of this variability was explainable by variations in average duration of illness. Longer duration of illness was associated with lower negative-negative symptom-pair correlations and higher negative-positive symptom-pair correlations. Conclusions. The findings suggest that the structure of symptoms in schizophrenia evolves over time, following a consistent pattern. In the early stages of illness, negative and positive symptoms form cohesive dimensions. With time, these dimensions become less cohesive and the boundaries between them, less clear.
Behavioral sensitivity of temporally modulated striatal neurons.

Recent investigations into the neural mechanisms that underlie temporal perception have revealed that the striatum is an important contributor to interval timing processes, and electrophysiological recording studies have shown that the firing rates of striatal neurons are modulated by the time in a trial at which an operant response is made. However, it remains unclear whether striatal firing rate modulations are related to the passage of time alone (i.e., whether temporal information is represented in an “abstract” manner independent of other attributes of biological importance), or whether this temporal information is embedded within striatal activity related to co-occurring contextual information, such as motor behaviors. This study evaluated these two hypotheses by recording from striatal neurons while rats performed a temporal production task. Rats were trained to respond at different nosepoke apertures for food reward under two simultaneously active reinforcement schedules: a variable-interval (VI-15 sec) schedule and a fixed-interval (FI-15 sec) schedule of reinforcement. Responding during a trial occurred in a sequential manner composing 3 phases; VI responding, FI responding, VI responding. The vast majority of task-sensitive striatal neurons (95%) varied their firing rates associated with equivalent behaviors (e.g., periods in which their snout was held within the nosepoke) across these behavioral phases, and 96% of cells varied their firing rates for the same behavior within a phase, thereby demonstrating their sensitivity to time. However, in a direct test of the abstract timing hypothesis, 91% of temporally modulated “hold” cells were further modulated by the overt motor behaviors associated with transitioning between nosepokes. As such, these data are inconsistent with the striatum representing time in an “abstract’ manner, but support the hypothesis that temporal information is embedded within contextual and motor functions of the striatum.
Mossy Fiber Sprouting in the Dentate Gyrus

Aberrant sprouting of granule cell axons is a common feature in temporal lobe epilepsy. An increasingly detailed picture of granule cell circuit changes has emerged, but the cause-effect relationship between mossy fiber sprouting and epileptogenesis remains unclear. Recent progress in suppressing mossy fiber sprouting might help address its functional consequences. For an expanded treatment of this topic see Jasper's Basic Mechanisms of the Epilepsies, Fourth Edition (Noebels JL, Avoli M, Rogawski MA, Olsen RW, DelgadoEscueta AV, eds) published by Oxford University Press (available on the National Library of Medicine Bookshelf [NCBI] at www.ncbi.nlm.nih.gov/ books).
Patterns of age mixing and sexually transmitted infections

Age mixing is an important indicator of sexually transmitted infection (STI) prevalence in partner pools. We use the 1995 National Survey of Family Growth (NSFG), a nationally representative sample of reproductive-age American women, to assess the extent of age mixing and to examine the association between age mixing and STI history. Almost half (48%) of the women in our sample report partnerships with much older or younger men. The likelihood of an STI diagnosis or receipt of STI care (test or treatment) increases as the age difference increases among adolescents. Women in their mid-to-late 20s with much younger partners report receipt of STI care more often than other women. Report of an STI diagnosis is more common among older women with much younger partners than among others of their age. Age-mixing information may be helpful for screening initiatives and targeting interventions aimed at decreasing STI rates, their sequelae, and STI transmission.
Real-time pulse-width monitor for ICCD electro-optic shutters

A method is described for controlling and measuring the pulse width of electrical gate pulses used for optical shuttering of image intensifiers. The intensifiers are coupled to high frame rate Charge-Coupled-Devices (CCD) or Focus-Projection Scan vidicon TV cameras for readout and telemetry of time resolved image sequences. The shutter duration or gate width of individual shutters is measured in real time and encoded in the video frame corresponding to a given shutter interval. The shutter information is updated once each video frame by strobing new data with each TV camera vertical sync pulse. This circuitry is used in conjunction with commercial video insertion/annotation equipment to provide the shutter width information in alpha numeric text form along with the time resolved video image on a frame-by-frame basis. The measurement technique and circuitry involving a combination of high speed digital counters and analog integrators for measurements in the 1 ns to 1024 ns range are described. The accuracy obtained is compared with measurements obtained using high speed DSOs. The measured data are provided in 10-bit Binary (Bi) and four decades of Binary Coded Decimal and also displayed on four digit seven segment displays. The control circuitry including digital and analog input means for gate width selection are described. The implementation of both measurement and control circuitry into an Intensified Shuttered CCD radiometric system for recording fast shuttered images at RS-170 to 4 KHz frame rates is presented.© (1997) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
The moral autonomy of science and the recombinant DNA controversy.

Abstract Some very important moral lessons for the practice of science were supposed to be found in the Recombinant DNA controversy. This is not so. But it is important to realize why it is not so; otherwise we are likely to see repetitions of that controversy as genetics (and other sciences) advance. This essay argues that, in spite of the criticisms levelled against it, the thesis of the moral autonomy of science is correct when restricted to its essential aspect: the knowledge that results from scientific research. Sometimes the autonomy thesis is inappropriately extended to the process by which scientific knowledge is obtained. For such extensions the thesis need not hold; but this conclusion is trivial. It is also argued that risk—benefit analysis is not a proper tool for the resolution of such controversies as that of Recombinant DNA, where enormous possible dangers are to be weighed against enormous possible benefits.
Lac repressor is a transient gene-activating protein.

Abstract We show, using a combination of methods, that contrary to the usual view, lac repressor increases, by more than 100-fold, the initial binding of RNA polymerase to E. coli lac UV5 promoter DNA. Kinetic studies revealed that the repressor acts to block the isomerization step in transcription initiation. When IPTG, a gratuitous inducer, is added, formation of open complex and productive transcription proceed. Because of the large increase in the binding constant, at low polymerase concentrations the presence of lac repressor (and then inducer) actually increases the rate of the first round of productive transcription, thus allowing the system to respond rapidly to the release of repression. This dual role of stabilization of a pretranscriptional complex coupled with blockage of transcription initiation may be a more general model for genetic regulation than that provided by the concept of simple repression.
Toll-like receptor 4-dependent microglial activation mediates spinal cord ischemia-reperfusion injury

Background— Paraplegia continues to complicate thoracoabdominal aortic interventions. The elusive mechanism of spinal cord ischemia–reperfusion injury has delayed the development of pharmacological adjuncts. Microglia, the resident macrophages of the central nervous system, can have pathological responses after a variety of insults. This can occur through toll-like receptor 4 (TLR-4) in stroke models. We hypothesize that spinal cord ischemia–reperfusion injury after aortic occlusion results from TLR-4–mediated microglial activation in mice. Methods and Results— TLR-4 mutant and wild-type mice underwent aortic occlusion for 5 minutes, followed by 60 hours of reperfusion when spinal cords were removed for analysis. Spinal cord cytokine production and microglial activation were assessed at 6 and 36 hours after surgery. Isolated microglia from mutant and wild-type mice were subjected to oxygen and glucose deprivation for 24 hours, after which the expression of TLR-4 and proinflammatory cytokines was analyzed. Mice without functional TLR-4 demonstrated decreased microglial activation and cytokine production and had preserved functional outcomes and neuronal viability after thoracic aortic occlusion. After oxygen and glucose deprivation, wild-type microglia had increased TLR-4 expression and production of proinflammatory cytokines. Conclusions— The absence of functional TLR-4 attenuated neuronal injury and microglial activation after thoracic aortic occlusion in mice. Furthermore, microglial upregulation of TLR-4 occurred after oxygen and glucose deprivation, and the absence of functional TLR-4 significantly attenuated the production of proinflammatory cytokines. In conclusion, TLR-4–mediated microglia activation in the spinal cord after aortic occlusion is critical in the mechanism of paraplegia after aortic cross-clamping and may provide targets for pharmacological intervention.
Post-irradiation Polymerization of Visible Light-activated Composite Resin

The rate of post-exposure polymerization and the effects of initial polymerization on the final polymerization of visible light-activated composite resin were studied. The extent of polymerization, as indicated by hardness values, was influenced by the exposure time to the photo-activating radiation and by the post-exposure time. The timing of testing is critical when studying the properties of visible light-activated composite resins.
An empirical study of long lived bugs

Bug fixing is a crucial part of software development and maintenance. A large number of bugs often indicate poor software quality since buggy behavior not only causes failures that may be costly but also has a detrimental effect on the user's overall experience with the software product. The impact of long lived bugs can be even more critical since experiencing the same bug version after version can be particularly frustrating for user. While there are many studies that investigate factors affecting bug fixing time for entire bug repositories, to the best of our knowledge, none of these studies investigates the extent and reasons of long lived bugs. In this paper, we analyzed long lived bugs from five different perspectives: their proportion, severity, assignment, reasons, as well as the nature of fixes. Our study on four open-source projects shows that there are a considerable number of long lived bugs in each system and over 90% of them adversely affect the user's experience. The reasons of these long lived bugs are diverse including long assignment time, not understanding their importance in advance etc. However, many bug-fixes were delayed without any specific reasons. Our analysis of bug fixing changes further shows that many long lived bugs can be fixed quickly through careful prioritization. We believe our results will help both developers and researchers to better understand factors behind delays, improve the overall bug fixing process, and investigate analytical approaches for prioritizing bugs based on bug severity as well as expected bug fixing effort.
Animal models of peripheral nerve injury

Nerve injury, repair, and regeneration are difficult areas to study in the human clinical situation, because of the inability to sample tissues to elucidate the injury, inflammation, and repair events without causing significant damage to the peripheral nerve. This inability to obtain tissue also precludes the ability to longitudinally evaluate the effect of an injury or intervention. Imaging modalities to evaluate the peripheral nerve are limited in their ability to image nerve injury, except when the nerve is divided.
Effect of 5-fluorouracil on poliovirus-induced RNA polymerase.

HeLa cells were infected with type 1 poliovirus in drug-free medium and in medium containing 1.2 × 10−3 m-5-fluorouracil during the first 2.5 hours of virus growth. Extracts of poliovirus polymerase were prepared and the effects of manganese ions and heat (51 to 52 °C) on enzyme activity were tested. No differences were observed between the control enzyme extracts and enzyme that was obtained from cells exposed to fluoropyrimidine. Cells were also infected with FU-virus (poliovirus grown in the presence of 1.2 × 10−3 m-5-fluorouracil). The incorporation of 14C-labeled GMP into perchloric acid-precipitable polyribonucleotide by poliovirus polymerase that was extracted from these cells was more sensitive to inhibition by manganese ions and more resistant to heat than control enzyme preparations. After two passages in the absence of drug, the progeny of fluorouracil-substituted virus still induced the synthesis of a modified polymerase. The data suggest that the messenger for at least part of the new enzyme activity appearing in poliovirus-infected cells is the parental ribonucleic acid.
Analysis of Uncertainty of Hypocenter Location Using the Combination of a Borehole Vertical Array And a Subsurface Array Network

A monitoring network composed of a vertical VSP array and a subsurface array can reliably locate microseismic events by using a traditional seismological location method. This distributed array method, which depends only on the first arrival times of P and/or S phases, avoids using timeconsuming, inconvenient and less-reliable measurements of signal azimuth and inclination angle to locate event hypocenters. Numerical analyses of hypocenter uncertainties demonstrate that events located by time-terms alone can achieve better location reliability than hypocenters located by range & bearing methods common to single VSP receiver configurations. The distributed array method is also applicable to those events identified with only S-phase arrivals.
Pareto and contemporary economic theory

This paper provides explanations for Pareto’s apparently contradictory approach to demand theory in simultaneously insisting that measurability of utility is not needed to explain the equilibrium of consumers in competitive markets, and embracing concavifiability and thus measurability of utility when this implies restrictions on consumers’ behavior such as the law of demand. It also treats his method of calibrating an aggregate demand function by employing his law of income distribution, so as to reproduce “Gregory King’s law”. Finally, some disputed issues are dealt with concerning the nature of Pareto’s contributions to welfare economics. (JEL: B13, D11, D60).
Removal of intravascular foreign body with stone retriever

Removal of an intravascular foreign body using a stone retriever was recently performed successfully. The technique is discussed.
A magnetic‐reluctance thickness gauge for high conductivity, ferromagnetic films

A magnetic comparator for measuring the thickness of high conductivity, ferromagnetic films is described. The instrument compares the reluctance of a standard sample to that of a film of unknown thickness at the same value of magnetic field intensity to insure that the permeability is the same for both. The comparator utilizes an ac Hartshorn, mutual‐inductance bridge configuration and is designed to operate at low frequency and low magnetic field intensity to maximize the skin depth δ and thus the measurable film thickness. The output of the comparator is linear in thickness for films less than δ/2 and is capable of measuring films of thickness greater than δ with some reduction in accuracy. The effects of the skin depth and magnetic properties of the film on the accuracy of the comparator are discussed.
Prediction of resistance in constant‐pressure cake filtration

Methods of predicting resistance in constant-pressure cake filtration have been classified into three groups, (1) basic particle and cake properties, (2) permeability tests, and (3) small-scale filtration tests. Methods 2 and 3 involve the concept of specific filtration resistance, a property characteristic of each unit mass of deposited cake, and these methods were extensively investigated in the laboratory. Specific resistances for three chemical slurries were determined by laboratory filtrations and filter- and compression-permeability tests. Results of these investigations showed that specific filtration resistance could be predicted from compression-permeability test data. Filtration tests made on commercial-scale equipment operating on pearl cornstarch illustrated the correlation between predicted and actual specific resistance values, the resistance predicted from compression-permeability test data agreeing very well with the actual resistance of the prefilt.
Organogenesis in pepper tissue cultures

Knowledge concerning in vitro growth and developmental responses of bell and chile peppers (Capsicum annuum L.) has been limited. Shoot and root organogenesis in cultures of seedling explants was restricted to primary cultures or those less than three months old under 12-and 16-h photoperiod at 25°C. Shoot organogenesis was extended to 5 months under continuous light at 25°C, and to 8 months under continuous light at 28.5°C. Murashige and Skoog basal media containing 0.05mg/l each of IAA and BA promoted shoot elongation and rooting of some explant sources, while 0.05-4 mg/l IAA with 10–50 mg/l BA promoted adventitious shoot bud formation. Glucose was superior to sucrose as the carbon source. Leaf discs collected from greenhouse-grown plants regenerated shoots for at least 2 months. Incubation environment, carbon source, explant source, growth regulator treatment and passage number were not independent variables as demonstrated by statistical analysis. The plant regeneration techniques described here have useful but limited applications, not extending to unorganized callus or cell suspension cultures.
Pre-college preparedness and institutional factors for student success on the uniform CPA examination in Texas

This study examines determinants of accounting students' successful bid for the uniform Certified Public Accountant (CPA) examination in Texas. With a sample of data from 30 public universities in Texas from 2005 to 2007, our analysis suggests that academic deficiency of incoming first-year students explains 49% of the institutional variation in the CPA exam pass rate. In contrast, educational quality (as measured by faculty salary, AACSB accreditation in accounting and accounting programme size) provides a less pronounced contribution to success in the CPA examination (13% of the institutional variation). Thus, the institution-level variation in the CPA exam pass rate among public universities in Texas seems to be predetermined to a great extent by the pre-college preparation of the students they admit.
Breaking the bonds: non-viral vectors become chemically dynamic.

The delivery of a variety of nucleic acids such as plasmid DNA (pDNA) and small interfering RNA (siRNA) to mammalian cells is both an important research tool and potential therapeutic approach. Synthetic vehicles (SVs) that include lipoplexes and polyplexes, are widelyused for non-viral delivery. A promising method of improving the efficacy of this approach is to create SVs that are chemically dynamic, so that delivery is enabled by the cleavage of chemical bonds upon exposure to various physiological environments or external stimuli. An example of this approach is the use of masked endosomolytic agents (MEAs) that improve the release of nucleic acids from endosomes, a key step during transport. When the MEA enters the acidic environment of the endosome, a pH-labile bond is broken, releasing the agent';s endosomolytic capability. Another challenge has been to develop SVs that enable in vivo delivery. Recently, an MEA that was used within dynamic polyconjugates (DPCs) enabled the efficient delivery of siRNA into hepatocytes in vivo. The use of labile bonds to mask endosomolytic agents, provides a critical design feature, because it enables efficient in vivo delivery without sacrificing endosomolytic function for release into the cytoplasm.
REVISE POLICIES MANDATING OFFENDER DNA COLLECTION

Currently, all states in the United States require some categories of convicted offenders to submit physical samples for later DNA analysis. The results of these analyses are DNA profiles available to law enforcement. One of the stated goals of legislation, cited in supporting court cases, has been to deter offenders from reoffending. State legislatures in recent years have increased dramatically the scope of offenders who are required to submit samples. Empirical work on deterrence suggests that these recent expansions are undermining the deterrence potential of these policies. That potential can be restored only by reversing the recent and planned policy expansions.
Sensitivity analysis of tax incidence in a spatial equilibrium model

In this paper, we show that the impact of an ad valorem tax on demand prices is the same for all interrelated spatial regions regardless of sizes of their price elasticities. In the case of a degenerate spatial equilibrium model in which several independent submarkets develop, the tax incidence is identical within a submarket; but varies between different submarkets. In the case of non-linear and/or non-separable demand and supply functions, the same results hold as long as (i) the tax does not affect unit transportation costs and (ii) a unique equilibrium commodity flow solution exists.
Comparison of intramolecular and intermolecular reactions in protein folding

The intrinsic component of the standard free energy change for the formation of a disulfide bond in a protein molecule is compared to that for an analogous chemical reaction. The former reaction, which represents theintramolecular formation of a disulfide bond in a protein molecule from a cysteine group containing a mixed disulfide bond with glutathione, and a free cysteine residue, is a unimolecular reaction. In contrast, its chemical analogue is a bimolecular reaction, and corresponds to theintermolecular disulfide interchange between a mixed disulfide-bonded compound between a cysteine residue and glutathione, and a free cysteine molecule. The difference in the intrinsic free energy of the above two reactions is estimated by two different approaches. First, a theoretical estimate of the magnitude of the difference in free energy of the two reactions (for a standard state of 1 M) is obtained using a gas-phase statistical thermodynamic approach, which indicates that the intramolecular reaction is energetically favored over its intermolecular counterpart by as much as 15.6 kcal/mole. For comparison, an experimentally derived value is also obtained, using experimental data from a study by Konishi et al. of the regeneration of the protein ribonuclease A (RNase A) from its reduced form by reduced and oxidized glutathiones. The intrinsic component of the free energy change of the intramolecular reaction, as it occurs in the protein molecule, is obtained from such experimental data by accounting explicitly for the free energy change (assumed to be solely an entropy change) pertaining to the conformational changes (ring closure) that the protein molecule undergoes in the course of the reaction. On the basis of the value derived from such an experimental approach, the intramolecular reaction is also energetically more favorable as compared to its intermolecular analogue, but only by a difference of 2.3 kcal/mole (for a standard state of 1 M). The large apparent discrepancy between the two values estimated from the theoretical and experimental approaches is rationalized by the postulation of several additional factors not inherent in the gas-phase theoretical estimate, such as dehydration and intramolecular hydrogen-bonding effects, which can largely compensate for the otherwise favorable energetics of the intramolecular reaction.
Gene positioning and expression.

Within the nucleus, the genome is spatially organized. Individual chromosomes are non-randomly positioned with respect to each other and with respect to nuclear landmarks [ 1 , 2 ]. Furthermore, the position of individual genes can reflect their expression. Here we discuss two well-characterized examples of gene relocalization associated with transcriptional activation: 1) developmentally regulated genes that move from the nuclear periphery to transcription factories in the nucleoplasm upon induction and 2) genes that are targeted from the nucleoplasm to the nuclear periphery, through interactions with the nuclear pore complex (NPC), upon activation. Finally, we speculate as to the mechanistic and functional commonalities of these phenomena.
Electron transfer between methyl viologen radicals and graphene oxide: Reduction, electron storage and discharge

Abstract Photochemically generated methyl viologen radicals undergo electron transfer with graphene oxide (GO) in ethanol suspensions. This charge transfer interaction results in the reduction of GO as well as storage of electrons. The stored electrons can be utilized to reduce Ag + ions and thus anchor silver nanoparticles on reduced graphene oxide (RGO). The spectroscopic experiments that elucidate the quantitative electron transfer and transmission electron microscopy that highlights the potential of designing metal–RGO assemblies are discussed.
Mitochondrial evolution and phylogeography in the hydrozoan Obelia geniculata (Cnidaria)

The distribution and genetic structure of many marine invertebrates in the North Atlantic have been influenced by the Pleistocene glaciation, which caused local extinctions followed by recolonization in warmer periods. Mitochondrial DNA markers are typically used to reconstruct species histories. Here, two mitochondrial markers (16S rDNA and cytochrome c oxidase I (COI)) were used to study the evolution of the widely distrib- uted hydrozoan Obelia geniculata (Linnaeus, 1758) from the North Atlantic and the Pacific and, more specifically, in the context of North Atlantic phylogeography. Sam- ples were collected from six geographic localities between 1998 and 2002. Hydroids from the North Atlantic, North Pacific (Japan), and South Pacific (New Zealand) are reciprocally monophyletic and may repre- sent cryptic species. Using portions of the 16S rDNA and COI genes and the date of the last trans-Arctic interchange (3.1-4.1 million years ago), the first cali- brated rate of nucleotide substitutions in hydrozoans is presented. Whereas extremely low substitution rates have been reported in other cnidarians, mainly based on anthozoans, substitution rates in O. geniculata are comparable to other invertebrates. Despite a life history that ostensibly permits substantial dispersal, there is apparently considerable genetic differentiation in O. geniculata. Divergence estimates and the presence of unique haplotypes provide evidence for glacial refugia in
Underwater object tracking using electrical impedance tomography

Few effective technologies exist for sensing in dark or murky underwater situations. For this reason, we have been exploring the use of a novel biologically-inspired approach to non-visual sensing based on the detection of perturbations to a self generated electric field. This is used by many species of neotropical nocturnal freshwater fish. This approach, termed active electrosense, presents unique challenges for sensing and tracking of nearby objects. We explore two methods for estimating the velocity of objects through active electrosense. The first of these methods uses a simple cross-correlation method, which depends on the uniformity of the electric field. We show some of the ramifications of making this assumption for a self-generated field around a cylindrical pod-shaped sensor in a rectangular tank. We then evaluate the use of methods developed for electrical impedance tomography (EIT) for localization and tracking. This is an unusual application of EIT in that typical applications involve surrounding the volume of interest (such as the thorax of humans) with sensor/emitters. Here, rather than this “outside in” approach, we are using EIT “inside out.” In simulation, we nonetheless find significant improvements in the accuracy of estimated velocity when using the EIT approach. Additionally, we demonstrate how EIT may be used for accurate position estimation. Under the conditions evaluated, the computation time for inversion is low enough to make its use feasible as a primary position and velocity estimator in an on- line system or as a secondary system to augment a computationally inexpensive estimator.
Belatacept: The Promises and Challenges of Belatacept and Costimulatory Blockade

The publication of the belatacept phase III studies offers a challenge in balancing benefits such as reduced burden of toxicity against risks such as EBV complications and more T cell mediated rejection.
The nonlinear response and rupture of lightly crosslinked elastomers

Recently a molecular treatment of nonlinear rubberlike viscoelasticity was advanced which centers around the precept that the nonlinear response is due to the nonlinear character of the stress-strain curve while the relaxation mechanism remains invariant to large stress or deformations. Excellent agreement was found for highly crosslinked systems, the result being in substantial agreement with classical kinetic theory. The experimental and theoretical work presented here extends this treatment to lighter cross-linked systems where substantial disagreement is found between classical theory and experiment. Attributing this disagreement to a deficiency in the treatment of the mechanics of long-range motions in imperfect network structures, it is possible to outline an integrated treatment of the long time creep in the plateau region, the “C2 effect,” the tensile strength maximum as a function of the crosslink density and the so-called “unique” properties of salt cured carboxylic rubbers. Experimental evidence is presented which shows that lightly crosslinked SBR exhibits properties indistinguishable from the salt-cured carboxylic vulcanizates.
Evidence of the existence of the high-density and low-density phases in deeply-cooled confined heavy water under high pressures

The average density of D2O confined in a nanoporous silica matrix (MCM-41-S) is studied with neutron scattering. We find that below ∼210 K, the pressure-temperature plane of the system can be divided into two regions. The average density of the confined D2O in the higher-pressure region is about 16% larger than that in the lower-pressure region. These two regions could represent the so-called “low-density liquid” and “high-density liquid” phases. The dividing line of these two regions, which could represent the associated 1st order liquid-liquid transition line, is also determined.
The establishment of cell suspension cultures of Gladiolus that regenerate plants.

Inflorencence stalks from greenhouse-grownGladiolus plants of the cultivars ‘Blue Isle’ and ‘Hunting Song’ cultured on a Murashige and Skoog basal salts medium supplemented with 53.6 μM 1-napthaleneacetic acid formed a compact, not friable type of callus that regenerated plantlets. Cormel slices and intact plantlets of three cultivars (‘Peter Pears’, ‘Rosa Supreme’, ‘Jenny Lee’) propagated through tissue culture formed a friable type of callus when cultured on Murashige and Skoog basal salts medium supplemented with 2,4-dichlorophenoxyacetic acid. This friable callus readily formed a cell suspension when the callus was placed in a liquid medium. Plants were regenerated from two-month-old suspension cell cultures of the commercial cultivar ‘Peter Pears’ after the suspension cells had been cultured on solid medium.
Mechanism of complement-mediated thromboxane production by the perfused rabbit liver: lack of effect of dantrolene sodium.

Abstract Activated components of the complement system have been shown to stimulate the arachidonic acid cascade. We have reported that hepatic thromboxane production in response to plasma activated with zymosan is self-limiting, not affected by nifedipine, but inhibited by mepacrine, a phospholipase inhibitor. To further study this relationship, we have tested the effects of dantrolene sodium, an agent reported to immobilize intracellular calcium. Control group livers were perfused with Krebs-Henseleit bicarbonate buffer at a rate of 120 ml/min in a nonrecirculating perfusion system and administered 1 ml/min of normal rabbit plasma for 10 minutes. This group of livers demonstrated stable wet weight, perfusion pressure, and rates of release of lactic dehydrogenase, thromboxane B2, and prostacyclin over a 150 minute experimental period. In contrast, the administration of 1 ml/min of zymosan-activated plasma resulted in significant increases in the rate of thromboxane B2 release at 1, 3, and 5 minutes after the start of the infusion. The rate of thromboxane production then returned to baseline values. Neither prostacyclin nor lactic dehydrogenase release changed significantly after ZAP. A similar change in thromboxane production following ZAP administration was seen in livers being continually perfused with 10 μM dantrolene sodium. Perfusion pressure was significantly elevated in this group during the ZAP infusion period. These results confirm complement-mediated thromboxane production in the isolated rabbit liver model but do not describe a definitive role of dantrolene-sensitive intracellular calcium release in the mechanism of ZAP-mediated thromboxane production.