cssi/SciSciGPT-SciSciNet huggingface dataset:
An M/M/c type of queueing model with ( R i , r i ) switch-over policy

Abstract In this paper, we study an M / M / c type of queueing model with ( R i , r i ) switch-over policy. When there are i machines in operation, one machine will be deactivated if the queue length drops to a predetermined level r i and an additional machine will be activated if the queue length increases to another predetermined level R i (> r i ). This type of queueing model has applications in production/inventory systems when more than one machine is available and the continuous review inventory policy is applied. The steady-state probabilities of the queue length and some other measures of performance, such as the mean queue length and the number of machines activated during a production cycle, are derived. The optimal values of the parameters ( R i , r i ) are studied and a number of different numerical examples are given.
Hidden Deviance and the Labelling Approach: The Case for Drinking and Driving

In this study we attempt to explain the over-representation of certain social categories—such as blacks or lower-class males—in official conviction statistics for drinking-driving. Two alternative perspectives are examined. The first, or “impartial” model, suggests that the probability of conviction is determined primarily by the degree and/or frequency of deviance. According to the second, or “labelling” model, this probability is at least partly independent of degree or frequency. In general, our findings are consistent with the latter model, although some support is also given to the “impartial” model as well.
The End of the Beginning for the Brain

After romping through the history of artificial intelligence, Kurzweil presents hierarchical, hidden Markov models as the means to understanding of the mind.
Effect of Alloy Composition on Carburizing Performance of Steel

This paper investigates the effect of alloy composition on the gas carburizing performance of AISI 1018, 4820, 5120, and 8620 steels. The mass-transfer coefficients and carbon diffusivities were calculated from experimental measurements using direct flux integration. Although steels with high concentration of austenite-stabilizing elements (Si, Ni) increased carbon diffusivity in austenite, they significantly reduced the kinetics of carbon transfer from the atmosphere to the steel surface and resulted in lower weight gain. Despite lowering the carbon diffusivities, steels alloyed with carbide-forming elements (Cr, Mo) significantly increased the mass-transfer coefficient in the atmosphere and enhanced the rate of carbon profile evolution. The experimentally determined carbon diffusivities were in good agreement with the carbon diffusivities obtained from the thermodynamic and kinetic databases in DICTRA. Overall, using the concentration dependent mass-transfer coefficient and carbon diffusivity in various alloy steels helped explain the experimentally observed variations in the carbon concentration profiles and the effective case depths. Recommendations are made to help achieve better case depth uniformity within a carburizing workload.
Variable block size motion compensation: block matching and optical flow

Many video compression systems use motion-compensated prediction to take advantage of the temporal redundancy. Typically, the motion compensation is done on a block-by-block basis using a fixed block size. This paper examines methods to improve motion estimation and compensation through the use of optical flow and adaptive block-based methods. The basic idea in both approaches is the same: to use larger blocks for regions of the image that have less detailed texture, and to use smaller blocks for more complicated regions. The best way to obtain the motion vectors for each block is examined in detail.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
A unified systolic array for adaptive beamforming

Abstract We present a new algorithm and systolic array for adaptive beamforming. Our approach improves on McWhirter's pioneering work in two respects. First, our algorithm uses only orthogonal transformations and thus should have better numerical properties. Second, the algorithm can be implemented on one single p × p triangular array of programmable processors that offers a throughput of one residual element per cycle.
Autostabilizing airframe articulation: Animal inspired air vehicle control

The sparse sensing and limited articulation that are characteristic of human-engineered robotic systems contrast dramatically with sensorimotor systems observed in nature. Animals are richly imbued with sensors, have many points of articulation and are heavily over-actuated. In fact, the compliant nature of the body (or Plant) of most animals requires constant control input to the muscles for postural maintenance. In this study, we show how flying insects use a compliant airframe to maintain flight stability via active articulation of the frame. We first derive the equations of motion for a model flying insect, inspired by the hawkmoth, a large fast flying and agile insect. By linearizing the equations of motion about a hovering equilibrium, we demonstrate that abdominal motions are sufficient to stabilize flight on a scale of 50ms. We then tested whether these insects use the abdomen for flight control by first measuring the open-loop transfer function between visual pitch rotations and abdominal movement in a tethered moth preparation. The measured transfer function was consistent with an abdominal control strategy. We then closed the loop and found that moths actively stabilize visual pitch rotations using abdominal motion as the only control input. The behavior was robust to variations in gain and to a variety of visual stimuli. These experiments establish airframe articulation as a plausible control mechanism for active flight.
Attack induced by second-order schedules of reinforcement

Food-deprived pigeons were exposed to tandem, chain, and brief-stimulus second-order schedules in which the completion of three 80-sec fixed-interval components was followed by food delivery. Two birds attacked a nearby stuffed pigeon shortly after the presentation of either food-paired or food-nonpaired visual stimuli, as well as following food. The third subject exhibited predominantly postfood attack. These results suggest that the locus of schedule-induced attack can be controlled by a stimulus event, whether food delivery or key-color change, that reliably precedes a relatively long period of food unavailability.
Defining loading limits of static ponds for catfish aquaculture

Abstract Commercial channel catfish farming has emerged as the most important aquaculture industry in the United States. During the last two decades, industry growth has occurred by expansion in the number and area of facilities and through production intensification. Evidence suggests that catfish farming has apparently reached the limits of the production system as currently configured. The success of commercial catfish culture can be attributed in part to low production costs resulting from the inherent waste assimilation capacity of aquaculture ponds, although operating within this capacity is complex and associated with several poorly defined limitations and hidden costs. Loading limits for pond aquaculture are based on the waste assimilation capacity of ponds and tolerance limits of the cultured species. The important design and operational considerations affecting loading limits include temperature effects, oxygen requirements, fish water quality tolerance limits, organic matter decomposition, and nutrient removal. Engineering solutions for extending the loading limits of pond aquaculture must account for the highly dynamic and complex nature of the pond ecosystem, particularly processes related to phytoplankton and microbial dynamics. Characteristics of hypertrophic ponds amenable to engineering solutions include excessive phytoplankton biomass, dominance of phytoplankton communities by cyanobacteria, intense diurnal stratification, chronic undersaturation of dissolved oxygen at the sediment–water interface, and limitations of current aeration technology. Improvements in the profitability of catfish pond aquaculture requires broad-scale implementation of a production paradigm based on measures of performance efficiency.
Acculturation and self-reported health among Hispanics using a socio-behavioral model: the North Texas Healthy Heart Study

Acculturation is a continuous, firsthand contact with other cultures functioning at both group and individual levels and is reflected in our culturally diverse society, calling for a greater understanding of the environmental and cultural impact on health. Self-reported health (SRH), a robust and well validated predictor of future mortality for all racial/ethnic groups, has been differentially reported by Hispanics compared to whites, especially based on their acculturation status. This study investigated the relationship between acculturation and SRH among Hispanics. An adapted Andersen framework was used to develop logistic regression models to assess for an association between acculturation and general health status. Hispanic participants (n = 135), as part of the North Texas Healthy Heart Study, were administered standardized questionnaires on acculturation, psychosocial measures which included sense of control, stress, depression and social support and a single item SRH measure. In addition, physiological measurements and demographic characteristics including age, gender, body mass index, medical history, and socioeconomic status were also obtained. Bivariate analyses found Mexican-oriented participants 3.16 times more likely to report fair/poor SRH compared to Anglo-oriented Hispanics. Acculturation was also associated with SRH in multiple regression models controlling for enabling, need, and predisposing factors together (OR: 3.53, 95% CI: 1.04, 11.97). Acculturation status was associated with SRH after accounting for other underlying factors. Medical and public health professionals should promote the use of acculturation measures in order to better understand its role in Hispanic behaviors, health outcomes and health care use. Such research findings will contribute to the design of culturally sensitive prevention and treatment strategies for diverse and immigrant populations.
Role of Interferon-γ in Hypercholesterolemia-Induced Leukocyte–Endothelial Cell Adhesion

Background— A T-cell–mediated inflammatory response occurs in the microcirculation during acute hypercholesterolemia. The objective of this study was to define the contribution of T-lymphocyte–derived interferon-γ (IFN-γ) to the leukocyte–endothelial cell adhesion induced by hypercholesterolemia. Methods and Results— Intravital videomicroscopy was used to quantify the adhesion and emigration of leukocytes and oxidant stress (dihydrorhodamine [DHR] oxidation) in cremasteric venules. Wild-type (WT), IFN-γ−/−, and severe combined immunodeficiency (SCID) mice were placed on either a normal (ND) or high-cholesterol (HC) diet for 2 weeks. WT-HC mice exhibited exaggerated adhesion and emigration of leukocytes and enhanced DHR oxidation compared with WT-ND. The exaggerated adhesion responses and increased DHR oxidation were not seen in IFN-γ−/−–HC mice. SCID-HC mice also exhibited attenuated inflammatory responses compared with WT-HC. Reconstitution of either SCID-HC or IFN-γ−/−–HC mice with WT-HC splenocytes res...
Boron compounds as a dominant source of alpha particles in semiconductor devices

The interaction of cosmic ray neutrons and boron is demonstrated as the dominant source of alpha particles and other radiations in electronic devices utilizing borophosphosilicate glass (BPSG). A simple process modification is proposed to significantly reduce this intense source of ionizing radiation without compromising the reflow and passivation properties of BPSG.
Transistor performance of a “push-pull”, π-stacked bithiazole-ethylenedioxythiophene co-oligomer

The “push-pull” co-oligomer, 5,5′-bis(4,4′-dibutyl-2,2′-bithiazol-5-yl)-(3,4,3′,4′-bis(ethylenedioxy)-2,2′-dithienyl) (BT2B) was used to construct organic field effect transistors (OFETs) via vacuum evaporation or by solution casting of BT2B crystals. Crystalline OFETs made in either top- or bottom-contact configuration had measured field effect mobilities of (3–4) × 10−3 cm2 V−1 s−1. INDO and EHT molecular orbital calculations show that the HOMO is confined to the central EDOT fragment whereas the LUMO is concentrated on the relatively electron-poor bithiazole rings. This charge confinement, when combined with the molecular offset in the π-stacked crystal structure, leads to relatively small transfer integrals. Even so, the intrinsic hole mobility was computed to be as high as 0.86 cm2 V−1 s−1.
An in Vitro Model of Immune Complex-mediated Basement Membrane Zone Separation Caused by Pemphigoid Antibodies, Leukocytes, and Complement

In this study, an in vitro model of immune complex-mediated basement membrane zone separation caused by periphigoid antibodies, serum complement, and peripheral blood leukocytes is described. When cryostat sections of fresh-frozen normal human skin were treated with either of 4 bullous pemiphigoid sera containing complement-activating anti-basement membrane zone antibodies and subsequently incubated at 37°C with normal human peripheral blood leukocytes and fresh human serum, leukocytes attached to 96% of the basement membrane zone in 100% of sections. Sixty-seven percent of the sections developed focal areas of basement membrane zone separation resembling dermal-epidermal separation described in early pemphigoid lesions. In control sections in which either leukocytes, pemphigoid antibody or fresh human serum were omitted, significantly less leukocyte attachment and basement membrane zone separation occurred. Evidence that leukocytes caused separation was supported by an absolute requirement for viable leukocytes during incubation, a high correlation between leukocyte attachment and separation and experiments showing that leukocytes attached to the basement membrane zone were activated. This study provides the first in vitro evidence directly supporting a functional role for immune-complex mediated inflammation in the pathogenesis of basement membrane zone separation and blisters in bullous pemphigoid.
On the Bojarski-Lewis inverse scattering method

We assume that the backscattered electromagnetic far-field of a perfectly conducting scatterer is known for all aspects and for frequencies greater in magnitude than some positive number m . Then using standard integral equation techniques, we show how numerical instability enters into the Bojarski-Lewis inverse scattering method. Since the assumed knowledge of the backscattered field is even more complete than can be expected with radar, these results show that for radar applications the Bojarski-Lewis method is numerically unstable. Moreover we show, as expected, that the degree of instability depends directly upon m . The more low frequency information we haves (i.e, the smaller m is), the more stable the method is. In the concluding remarks is noted a recent constrained Bojarski-Lewis method that overcomes much of the instability of the original unconstrained method studied here.
Experimental investigation of an electric arc in transverse aerodynamic and magnetic fields.

An experimental study was made of the aerodynamic behavior and heat transfer of an electric arc of 200 to 400 amp which was held stationary in an atmospheric pressure cross-flow airstream of velocities up to 60 fps by a transverse magnetic field up to 50 gauss. An open-jettype facility permitted the use of diagnostic techniques in the arc wake region. The arc's significant dimension transverse and parallel to the flow was measured. This dimension increased perpendicular to the flow and decreased parallel to the flow when the transverse blowing velocity and magnetic field were increased. Velocity profiles, energy flux distributions, turbulence level and frequency measurements were obtained in the arc wake using miniaturized probe techniques. Flow visualization studies were performed. The input and output arc power distribution was obtained. Comparisons between the wake of the arc and that of a heated solid cylinder indicated similarity in vortex shedding frequency and convective heat transfer. The energy convectively transferred to the arc wake was equal to the additional electrical energy input required to maintain the arc in the presence of the transverse blowing. A drag coefficient for the arc, analogous to that of a solid cylinder in cross flow, was defined and measured to have values between 0.7 and 1.2.
A 'Tsc, Tsc' keeps the kids quie(scen)t and holds down ROS.

Tuberins, the tumor-suppressor proteins that regulate signaling via the kinase mTOR, now emerge as essential enforcers of T cell quiescence that promote survival.
Static grey-scale parathyroid ultrasonography: is high-resolution real-time technique required?

Ultrasound has been used with varying success to localise parathyroid adenomas pre-operatively. We have reviewed 61 patients with pre-operative contact-scanning grey-scale parathyroid ultrasonography and subsequent surgical exploration of all four parathyroid glands. Diagnostic accuracy was 91% considering glands examined and 63% considering patients examined. There was one false positive diagnosis. False negative diagnoses (17 adenomas and five ectopic mediastinal tumours) were mainly due to upper pole adenomas, adenomas less than 10 mm × 7 mm in size and ectopic mediastinal adenomas. Static grey-scale ultrasonography is adequate for the pre-operative localisation of parathyroid adenomas, especially when high-resolution technique is not available. In fact, the overall accuracy is comparable to the recently reported diagnostic accuracy rates with high-resolution real-time systems.
The impact of health insurance status on stage at diagnosis of oropharyngeal cancer.

BACKGROUND. Although patients who have early-stage oropharyngeal cancer can be treated with little impairment of function, the treatment of advanced disease can result in decreased quality of life and mortality. Patients without insurance and with other barriers to access to care may delay seeking medical attention for early symptoms, resulting in more advanced disease at presentation. In this study, the authors examined whether patients who had no insurance or who were covered by Medicaid insurance were more likely to present with advanced oropharyngeal cancer. METHODS. In this retrospective cohort study from the National Cancer Database from 1996 to 2003, patients with known insurance status who were diagnosed with invasive oropharyngeal cancer at Commission on Cancer facilities (n 5 40,487) were included. Adjusted and unadjusted logistic regression models were used to analyze the likelihood of presenting with more advanced stage disease. RESULTS. After controlling for other sociodemographic characteristics, patients with advanced oropharyngeal cancer at diagnosis were more likely to be uninsured (odds ratio [OR], 1.37; 95% confidence interval [95% CI], 1.21–1.25) or covered by Medicaid (OR, 1.31; 95% CI, 1.19–1.46) compared with patients who had private insurance. Similarly, patients were most likely to present with the largest tumors (T4 disease) if they were uninsured (OR, 2.82; 95% CI, 2.46–3.23) or covered by Medicaid (OR, 2.95; 95% CI, 2.63–3.31). They also were more likely to present with the greatest degree of lymph node involvement (N3) if they were uninsured (OR, 2.06; 95% CI, 1.76–2.40) or covered by Medicaid (OR, 1.66; 95% CI, 1.45–1.90). CONCLUSIONS. Individuals who lacked insurance or had Medicaid coverage were at the greatest risk for presenting with advanced oropharyngeal cancer. In the current study, the results for the Medicaid group may have been influenced by the postdiagnostic enrollment of uninsured patients. Insurance coverage appeared to be a highly modifiable predictor of cancer stage. The findings indicated that it is important to consider the impact of insurance coverage on disease stage at diagnosis and associated morbidity, mortality, and quality of life. Cancer 2007;110:395–402. � 2007 American Cancer Society.
Specificity and formation of unusual amino acids of an amide ligation strategy for unprotected peptides

An important step in the recently developed ligation strategy known as domain ligation strategy to link unprotected peptide segments without activation is the ring formation between the C-terminal ester aldehyde and the N-terminal amino acid bearing a 8-thiol or 8-hydroxide. A new method was developed to define the specificity of this reaction using a dye-labeled alanyl ester aldehyde to react with libraries of 400 dipeptides which contained all dipeptide combinations of the 20 genetically coded amino acids. Three different ester aldehydes of the dye-labeled alanine: α-formylmethyl (FM), β-formylethyl (FE), and β,β,β-dimethyl and formylethyl esters (DFE), were examined. The DFE ester was overly hindered and reacted with N-terminal Cys dipeptides (Cys-X). Interestingly, it also reacted slowly with the sequences of X-Gly where Gly was the second amino acid and the X-Gly amide bond participated in the ring formation. Although the FE ester reacted similarly as the FM ester in the ring formation, the subsequent O,N-acyl transfer was at least 30-fold slower than those of the FM-ester. The FM α-formyl methyl ester was the most suitable ester and was reactive with dipeptides of six N-terminal amino acids: Cys, Thr, Trp, Ser, His and Asn. The order and extent of their reactivity were highly dependent on pH, solvent and neighboring participation by the adjacent amino acid. In general, they could be divided into three categories. (1) N-Terminal Cys and Thr were the most reactive. Cys reacted very rapidly and completely within 0.5 h to form thiazolidine in both aqueous and high content of water-miscible organic solvents. Thr reacted to form oxazolidine slowly in aqueous buffer (t1/2 > 300 h) but rapidly and completely within 20 h in organic-water solvents. (2) N-Terminal Trp, His and Ser were comparatively much less reactive than Cys or Thr. Trp reacted slowly and completely in aqueous buffer but significantly more slowly and incompletely in water-organic solvents. Both His and Ser reacted very slowly and incompletely in both solvent systems. (3) Finally, Asn reacted nearly insignificantly in both solvent systems. The significant rate enhancement by the water-miscible organic solvent on Thr was particularly important to allow the synthesis of disulfide-rich protein domains. Furthermore, the ring formation with N-terminal Trp, His and Asn provided a convenient route to prepare their bicyclic and unusual heterocyclic derivatives for structure-activity study.
Does Graft Construct Lengthening at the Fixations Cause an Increase in Anterior Laxity Following Anterior Cruciate Ligament Reconstruction in vivo

A millimeter-for-millimeter relation between an increase in length of an anterior cruciate ligament graft construct and an increase in anterior laxity has been demonstrated in multiple in vitro studies. Based on this relation, a 3 mm increase in length of the graft construct following surgery could manifest as a 3 mm increase in anterior laxity in vivo, which is considered clinically unstable. Hence, the two primary objectives were to determine whether the millimeter-for-millimeter relation exists in vivo for slippage-resistant fixation of a soft-tissue graft and, if it does not exist, then to what extent the increase in stiffness caused by biologic healing of the graft to the bone tunnel offsets the potential increase in anterior laxity resulting from lengthening at the sites of fixation. Sixteen subjects were treated with a fresh-frozen, nonirradiated, nonchemically processed tibialis allograft. Tantalum markers were injected into the graft, fixation devices, and bones. On the day of surgery and at 1, 2, 3, and 4 months, Roentgen stereophotogrammetric analysis was used to compute anterior laxity at 150 N of anterior force and the total slippage from both sites of fixation. A simple linear regression was performed to determine whether the millimeter-for-millimeter relation existed and a springs-in-series model of the graft construct was used to determine the extent to which the increase in stiffness caused by biological healing of the graft to the bone tunnel offset the increase in anterior laxity resulting from lengthening at the sites of fixation. There was no correlation between lengthening at the sites of fixation and the increase in anterior laxity at 1 month (R(2)=0.0, slope=0.2). Also, the increase in stiffness of the graft construct caused by biologic healing of the graft to the bone tunnel offset 0.7 mm of the 1.5 mm potential increase in anterior laxity resulting from lengthening at the sites of fixation. This relatively large offset of nearly 50% occurred because lengthening at the sites of fixation was small.
42-V battery requirements from an automaker's perspective

Present and future automotive electrical loads are surveyed relative to power and electrochemical storage requirements. It is concluded that existing power and energy needs are near the maximum capability of the existing 14-V system, and that future automotive loads may be 10 kW or more. The efficiency of the electrical distribution system at this power level requires a higher voltage and safety considerations dictate that a 42-V limit will be the most satisfactory standard. The higher-voltage systems will likely include advanced controls, thermal management, and more complex architectures.
Taking the Blood Bank to the Field: The Design and Rationale of the Prehospital Air Medical Plasma (PAMPer) Trial

Hemorrhage and trauma induced coagulopathy remain major drivers of early preventable mortality in military and civilian trauma. Interest in the use of prehospital plasma in hemorrhaging patients as a primary resuscitation agent has grown recently. Trauma center-based damage control resuscitation using early and aggressive plasma transfusion has consistently demonstrated improved outcomes in hemorrhaging patients. Additionally, plasma has been shown to have several favorable immunomodulatory effects. Preliminary evidence with prehospital plasma transfusion has demonstrated feasibility and improved short-term outcomes. Applying state-of-the-art resuscitation strategies to the civilian prehospital arena is compelling. We describe here the rationale, design, and challenges of the Prehospital Air Medical Plasma (PAMPer) trial. The primary objective is to determine the effect of prehospital plasma transfusion during air medical transport on 30-day mortality in patients at risk for traumatic hemorrhage. This study is a multicenter cluster randomized clinical trial. The trial will enroll trauma patients with profound hypotension (SBP ≤ 70 mmHg) or hypotension (SBP 71-90 mmHg) and tachycardia (HR ≥ 108 bpm) from six level I trauma center air medical transport programs. The trial will also explore the effects of prehospital plasma transfusion on the coagulation and inflammatory response following injury. The trial will be conducted under exception for informed consent for emergency research with an investigational new drug approval from the U.S. Food and Drug Administration utilizing a multipronged community consultation process. It is one of three ongoing Department of Defense-funded trials aimed at expanding our understanding of the optimal therapeutic approaches to coagulopathy in the hemorrhaging trauma patient.
Repeatable sensitivity of optical-time-domain-reflectometry-based strain measurement

Optical time-domain reflectometry (OTDR) is a simple and rugged technique for measuring quantities such as strain that affect the propagation of light in an optical fiber. For engineering applications of OTDR, it is important to know the repeatable limits of its performance. The authors constructed an OTDR-based, submillimeter resolution, strain measurement system from off-the-shelf components. The system repeatably resolves changes in time of flight to within +/- 2 ps. Using a 1 m, single-mode fiber as a gauge and observing the time of flight between Fresnel reflections, we observed a repeatable sensitivity of 400 microstrains. Using the same fiber to connect the legs of a 3 dB directional coupler to form a loop, we observed a repeatable sensitivity of 200 microstrains. Realizable changes to the system that should improve the repeatable sensitivity to 20 microstrains or less are discussed.© (1993) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.
Na, K-ATPase β1-Subunit increases the translation efficiency of the α1-Subunit in MSV-MDCK cells

The Na,K-ATPase consists of an α- and β-subunit. Moloney sarcoma virus-transformed MDCK cells (MSV-MDCK) express low levels of Na,K-ATPase β1-subunit. Ectopic expression of Na,K-ATPase β1-subunit i...
Identification and Effect of Secondary Phase in MnO2-Doped 0.8Pb(Zr0.52Ti0.48)O3–0.2Pb(Zn1/3Nb2/3)O3 Piezoelectric Ceramics

0.8 Pb(Zr0.52Ti0.48)O3–0.2 Pb(Zn1/3Nb2/3)O3 (PZT–PZN) and 2 mol% Mn-doped PZT–PZN ceramics were investigated to deterministically identify the presence and effect of the secondary phase in controlling electrical properties. On the basis of the X-ray diffraction and energy dispersive spectroscopy analysis, we show that secondary phase in Mn-doped PZT–PZN is not MnO2 precipitate, but it is related to the formation of ZnO. This result was found to be consistent with the grain growth observed in the Mn-doped sintered ceramics and changes in ferroelectric behavior. We propose that Mn3+ substitution on Ti and Zr site induces hardening effect, whereas Mn2+ substitution on Zn-site stabilizes the perovskite phase in synthesis of PZT–PZN.
Binding of AID to DNA Does Not Correlate with Mutator Activity

The DNA deaminase activation-induced cytidine deaminase (AID) initiates somatic hypermutation (SHM) and class switch recombination (CSR) by deaminating cytidines to uridines at V region (V) genes and switch (S) regions. The mechanism by which AID is recruited to V genes and S region DNA is poorly understood. In this study, we used the CH12 B lymphoma line to demonstrate that, although S regions can efficiently recruit AID and undergo mutations and deletions, AID neither binds to nor mutates the V gene, thus clearly demonstrating intraimmunoglobulin locus specificity. Depletion of the RNA-binding protein polypyrimidine tract binding protein-2, previously shown to promote recruitment of AID to S regions, enables stable association of AID with the V gene. Surprisingly, AID binding to the V gene does not induce SHM. These results unmask a striking lack of correlation between AID binding and its mutator activity, providing evidence for the presence of factors required downstream of AID binding to effect SHM. Furthermore, our findings suggest that S regions are preferred targets for AID and, aided by polypyrimidine tract binding protein-2, act as “sinks” to sequester AID activity from other genomic regions.
Approaches to Cancer Prevention Based on an Understanding of N-Nitrosamine Carcinogenesis:

Understanding carcinogenesis is critical for development of rational approaches to cancer prevention. This paper uses N-nitrosamine carcinogenesis as an example. N-Nitrosamines are a large group of potent carcinogens. Approximately 300 different N-nitrosamines are carcinogenic. At least 30 animal species are responsive to their effects. There is little doubt that humans exposed to sufficient amounts of N-nitrosamines would also be susceptible to their carcinogenic effects. Human exposure to preformed N-nitrosamines occurs through the diet, in certain occupational settings, and through the use of tobacco products, cosmetics, pharmaceutical products, and agricultural chemicals. Diminishing human exposure to these carcinogens is one approach to prevention of cancer, and this has been accomplished in many instances, although exposure to N-nitrosamines in tobacco products is still unacceptably high. Human exposure to N-nitrosamines also occurs by nitrosation of amines in the body, via their acid or bacterial catalyzed reaction with nitrite, or by reaction with products of nitric oxide generated during inflammation or infection. A second approach toward prevention of N-nitrosamine carcinogenesis is inhibition of this endogenous N-nitrosamine formation. Substantial reductions have been achieved with ascorbic acid and other nitrite scavengers. N-Nitrosamines undergo a simple cytochrome P450-mediated metabolic activation step, which is critical for their carcinogenicity. The third approach involves the use of chemopreventive agents that block this step, or other steps in the carcinogenic process. A large number of potent chemopreventive agents against nitrosamine carcinogenesis have been identified. Chemoprevention of lung cancer induced by the tobacco-specific nitrosamine 4-(methylnitrosamino)-1-(3-pyridyl)-1-butanone (NNK) is discussed as an example of this approach.
Nasopharyngeal balloon catheter enhances endoscopic sinus surgery in the awake patient

A problem often encountered during endoscopic sinus surgery in an awake patient is the collection of secretions and blood in the naso-oropharynx. This triggers coughing, which is often disruptive to the surgeon, as well as being quite uncomfortable for the patient. Instillation of solutions to the surgical field to de-fog the endoscope exacerbate this problem. To alleviate this situation, we now use a nasopharyngeal balloon catheter, the Xomed Post Pac (Xomed Inc, Jacksonville, FL) to protect the pharynx of the awake patient undergoing endoscopic sinus surgery.
Application of Polymerase Chain Reaction for the Correlation of Salmonella Serovars Recovered from Greyhound Feces with Their Diet

The polymerase chain reaction was employed to correlate Salmonella serovars isolated from fecal material of greyhounds suffering from gastroenteritis with those isolated from the diet fed to the greyhounds prior to onset of diarrhea. Kennels around the Abilene, Kansas, area were contacted and supplied with materials needed to collect a portion of the diet each day. With the onset of diarrhea, the kennels were instructed to ship the fecal material and diet from the previous 10 days to the laboratory for testing. Forty-one fecal samples and corresponding diets were screened for Salmonella, Clostridium perfringens, Campylobacter jejuni, Staphylococcus aureus, Staphylococcus intermedius, and pathogenic (piliated) Escherichia coli by direct culture using standard procedures. The fecal material was also screened for coronavirus and parvovirus using electron microscopy. Thirty-five "normal" fecal samples were screened for all of the above mentioned microorganisms as a control. In addition, the fecal material was screened for E. coli verotoxins I and II and clostridial enterotoxins. A total of 61 Salmonella isolates were recovered from the 41 samples of feces and diet submitted for testing; 31 were recovered from the feces and 30 from the diet. Four Salmonella isolates were recovered from the normal fecal samples. Results obtained by PCR, plasmid profiles, antigenic analysis, and antibiogram profiles indicated that 16 of the 31 isolates recovered from the fecal material were the same strain as that recovered from the diet.
Whither tactical communications

The author presents an appeal to those concerned with military communications to work together to put an end to fractionated military communication systems, and provide well-designed, integrated, flexible, and survivable (but less expensive) voice and data communications for the soldier and commander of the future. It is suggested that MILCOM start the process by forming a civilian/military/government communication planning, coordination, and consulting committee dedicated to focusing standards, specifications, research, development, and engineering on coordinated integrated communications for military use. >
Feeding tallow triglycerides of different saturation and particle size to lactating dairy cows

Abstract Five multiparious Holstein cows, arranged in a 5×5 Latin square design, were fed a control diet (no supplemental fat) and diets containing 5% of the following fat supplements: flaked tallow with a low iodine value of 14.4 (FTL), prilled tallow with a low iodine value of 14.5 (PTL), prilled tallow with a medium iodine value of 25.8 (PTM) and fancy bleachable tallow with a high iodine value of 62 (BTH). Diets consisted of 50% forage and 50% concentrate and the fat supplements replaced corn in the control diet. Diets were isonitrogenous and blood meal was added to provide a similar concentration of rumen undegradable protein among diets. Each period consisted of 28 days; 14 days were for adaptation and 14 days were for data collection. Intake and milk yield were similar among cows fed the hydrogenated fat sources. Fatty acid digestibility appeared to be lowest for flaked tallow but similar between the prilled tallow supplements. The fancy bleachable tallow depressed dry matter intake and milk fat percentage. Total tract digestibility of neutral detergent fiber was lower for fancy bleachable tallow (32.8%) than for prilled tallow with low iodine value (50.2%). Feeding 5% tallow with an iodine value of 62 appeared to have caused detrimental effects on ruminal fermentation and resulted in poor performance by the dairy cows. The prilled and flaked tallow fed in this study appeared to be ruminally inert, but flaked tallow may be of low digestibility.
Arteriovenous fistulas following lumbar laminectomy: the anatomy defined.

Abstract Iatrogenic arteriovenous fistulas between the aorta or its major branches and the vena cava or its tributaries resulting from lumbar disc operations are uncommon but serious problems for the vascular surgeon. Using three cases from our experience and adding illustrations, x-ray films, and descriptive text we have precisely defined the anatomy of the major vessels at the L3-4, L4-5, and L5-S1 disc interspaces. This information will not only aid the surgeon in the repair of the chronic fistula but will help the surgeon who is called urgently to the operating room for bleeding and shock when preoperative angiography is not possible. (J VASC SURG 1985:2:828-33.)
Computation of zero directions of transfer functions

In this note we describe a state space approach to compute so-called zero directions of a rational transfer function H(/spl lambda/). The method works on the coefficient matrices of a minimal state space realization of the transfer function H(/spl lambda/) and does not require its Taylor expansion around each zero. Moreover, it uses only unitary transformations to find the structure at each zero. >
SYNCHROTRON SELF-COMPTON ANALYSIS OF TeV X-RAY-SELECTED BL LACERTAE OBJECTS

We introduce a methodology for analysis of multiwavelength data from X-ray-selected BL Lac (XBL) objects detected in the TeVregime. By assuming that the radioYthroughYX-ray flux from XBLs is nonthermal synchrotron radiation emitted by isotropically distributed electrons in the randomly oriented magnetic field of a relativistic blazar jet, we obtain the electron spectrum. This spectrum is then used to deduce the synchrotron self-Compton (SSC) spectrum as a function of the Doppler factor, magnetic field, and variability timescale. The variability timescale is used to infer the comoving blob radius from light-travel time arguments, leaving only two parameters. With this approach, we accurately simulate the synchrotron and SSC spectra of flaring XBLs in the Thomson through Klein-Nishina regimes. Photoabsorption by interactions with internal jet radiation and the intergalactic background light (IBL) is included.Dopplerfactors,magneticfields,andabsolutejetpowersareobtainedbyfittingtheH.E.S.S.andSwiftdataof the recent giant TeV flare observed from PKS 2155� 304. For the H.E.S.S. and Swift data from 2006 July 28 and 30, respectively, Doppler factors k60 and absolute jet powers k10 46 ergs s � 1 are required for a synchrotron/SSC model to give a good fit to the data, for a low intensity of the IBL and a ratio of 10 times more energy in hadrons than nonthermal electrons. Fits are also madetoa TeVflare observedin 2001fromMrk 421 which require Doppler factorsk30 and jet powers k10 45 ergs s � 1 . Subject headingg BLLacertaeobjects:general — BLLacertaeobjects:individual(PKS2155� 304,Mrk421) — galaxies: active — radiation mechanisms: nonthermal
Pharmacophore Model for Novel Inhibitors of Ubiquitin Isopeptidases That Induce p53-Independent Cell Death

The tumor suppressor p53 is mutated in more than 50% of all cancers. Importantly, most clinically useful antineoplastic agents are less potent and efficacious in the context of mutant p53. This situation has prompted a search for agents that cause tumor cell death via molecular mechanisms independent of p53. Our recent investigations with electrophilic prostaglandins enabled us to devise a pharmacophore and mechanism of action hypothesis relevant to this problem: a cross-conjugated alpha,beta-unsaturated dienone with two sterically accessible electrophilic beta-carbons is a molecular determinant that confers activity among this class of ubiquitin isopeptidases inhibitors, and that inhibitors of ubiquitin isopeptidases cause cell death in vitro independently of p53. Here, we report the use of the National Cancer Institute's Developmental Therapeutics Database to identify compounds to test this hypothesis. Shikoccin (a diterpene), dibenzylideneacetone, and curcumin fit the pharmacophore hypothesis, inhibit cellular isopeptidases, and cause cell death independently of p53 in isogenic pairs of RKO and HCT 116 cells with differential p53 status. The sesquiterpene achillin and 2,6-diphenyl-4H-thiopyran-4-one, which have cross-conjugated dienones with sterically hindered electrophilic beta-carbons, do not inhibit isopeptidases or cause significant cell death. Furthermore, we show that a catalytic-site proteasome inhibitor causes cell death independently of p53. Combined, these data verify the p53-independence of cell death caused by inhibitors of the proteasome pathway and support the proposition that the ubiquitin-dependent proteasome pathway may contain molecular targets suitable for antineoplastic drug discovery.
Insulin action in cells expressing truncated or kinase-defective insulin receptors. Dissection of multiple hormone-signaling pathways.

An attempt has been made to dissect insulin-signaling pathways by means of in vitro mutagenesis of the insulin receptor. Studies of two mutants are reviewed: a COOH-truncated receptor and a mutant of the ATPbinding site that is tyrosine kinase defective. The COOH-truncated receptor has normal insulin binding and normal endocytosis and undergoes autophosphorylation and activation as a kinase in vitro and in vivo. Loss of the COOH-terminal43 amino acids has, however, impaired the ability of the receptor to signal metabolic events while augmenting its ability to signal mitogenesis. Thus, domains have been partially identified that are separately involved in metabolic and mitogenic signaling, facilitating future studies of these pathways. The kinase-defective receptor is not only biologically inactive, but has a dominant inhibitory effect on the endogenous insulin receptors in the cell. That is, transfected Rat-1 cells carrying defective human receptors still have normally active rat insulin receptors but are incapable of signaling insulin action. The fact that metabolic signaling by insulinlike growth factor I (IGF-I) is intact in these cells allows definition of separate insulin and IGF-I pathways, leading to stimulation of glucose transport. Analysis of dose responsiveness for mitogenesis implies that mitogenic signaling pathways are shared by insulin and IGF-I, however. The utility of these cell lines in defining these pathways is discussed.
Implications of electron correlations for multiphoton excitation

Doubly excited states of atoms display strong electron correlations, particularly with increasing excitation and in the vicinity of the double-ionization limit. We discuss the nature of these correlations and the attendant implications for multiphoton excitation of such states. Questions discussed include favored and unfavored pathways of excitation and whether multiphoton multiple ionization of atoms proceeds through a sequential ejection of the electrons or through a direct simultaneous ejection into the multielectron continuum.
A fully programmable CMOS block matrix transform imager architecture

In this paper, we introduce our CMOS block matrix transform imager architecture (MATIA). This imager is capable of performing programmable matrix operations on an image. The imager architecture is both modular and programmable. The pixel used in this architecture performs matrix multiplication while maintaining a high fill-factor (46%), comparable to active pixel sensors. Floating gates are used to store the arbitrary matrix coefficients on-chip. The chip operates in the subthreshold domain and thus has low power consumption (0.23 mW).
Abbreviated Pathway for Biosynthesis of 2-Thiouridine in Bacillus subtilis

ABSTRACT The 2-thiouridine (s 2 U) modification of the wobble position in glutamate, glutamine, and lysine tRNA molecules serves to stabilize the anticodon structure, improving ribosomal binding and overall efficiency of the translational process. Biosynthesis of s 2 U in Escherichia coli requires a cysteine desulfurase (IscS), a thiouridylase (MnmA), and five intermediate sulfur-relay enzymes (TusABCDE). The E. coli MnmA adenylates and subsequently thiolates tRNA to form the s 2 U modification. Bacillus subtilis lacks IscS and the intermediate sulfur relay proteins, yet its genome contains a cysteine desulfurase gene, yrvO , directly adjacent to mnmA . The genomic synteny of yrvO and mnmA combined with the absence of the Tus proteins indicated a potential functionality of these proteins in s 2 U formation. Here, we provide evidence that the B. subtilis YrvO and MnmA are sufficient for s 2 U biosynthesis. A conditional B. subtilis knockout strain showed that s 2 U abundance correlates with MnmA expression, and in vivo complementation studies in E. coli IscS- or MnmA-deficient strains revealed the competency of these proteins in s 2 U biosynthesis. In vitro experiments demonstrated s 2 U formation by YrvO and MnmA, and kinetic analysis established a partnership between the B. subtilis proteins that is contingent upon the presence of ATP. Furthermore, we observed that the slow-growth phenotype of E. coli Δ iscS and Δ mnmA strains associated with s 2 U depletion is recovered by B. subtilis yrvO and mnmA . These results support the proposal that the involvement of a devoted cysteine desulfurase, YrvO, in s 2 U synthesis bypasses the need for a complex biosynthetic pathway by direct sulfur transfer to MnmA. IMPORTANCE The 2-thiouridine (s 2 U) modification of the wobble position in glutamate, glutamine, and lysine tRNA is conserved in all three domains of life and stabilizes the anticodon structure, thus guaranteeing fidelity in translation. The biosynthesis of s 2 U in Escherichia coli requires seven proteins: the cysteine desulfurase IscS, the thiouridylase MnmA, and five intermediate sulfur-relay enzymes (TusABCDE). Bacillus subtilis and most Gram-positive bacteria lack a complete set of biosynthetic components. Interestingly, the mnmA coding sequence is located adjacent to yrvO , encoding a cysteine desulfurase. In this work, we provide evidence that the B. subtilis YrvO is able to transfer sulfur directly to MnmA. Both proteins are sufficient for s 2 U biosynthesis in a pathway independent of the one used in E. coli.