gebhart/patrepeval huggingface dataset:
Microfluid mechanics: progress and opportunities (2001)

The application of microfabrication techniques to problems involving fluids is reviewed. A number of scientific issues have been addressed using microstructures designed to confine and manipulate fluids. These problems include studies of fluid motion in percolative structures, chemical applications involving small volumes of reactants and products, biologically inspired experiments involving the manipulation of individual molecules, and studies of fundamental properties of liquids in extremely small geometries. Representative work is described, along with the ingenious fabrication methods which have been developed.
Bayesian Estimation of Intrinsic Tissue Oxygenation and Perfusion From RGB Images (2017)

Multispectral imaging (MSI) can potentially assist the intra-operative assessment of tissue structure, function and viability, by providing information about oxygenation. In this paper, we present a novel technique for recovering intrinsic MSI measurements from endoscopic RGB images without custom hardware adaptations. The advantage of this approach is that it requires no modification to existing surgical and diagnostic endoscopic imaging systems. Our method uses a radiometric color calibration of the endoscopic camera's sensor in conjunction with a Bayesian framework to recover a per-pixel measurement of the total blood volume (THb) and oxygen saturation (SO<sub>2</sub>) in the observed tissue. The sensor's pixel measurements are modeled as weighted sums over a mixture of Poisson distributions and we optimize the variables SO<sub>2</sub> and THb to maximize the likelihood of the observations. To validate our technique, we use synthetic images generated from Monte Carlo physics simulation of light transport through soft tissue containing sub-surface blood vessels. We also validate our method on in vivo data by comparing it to a MSI dataset acquired with a hardware system that sequentially images multiple spectral bands without overlap. Our results are promising and show that we are able to provide surgeons with additional relevant information by processing endoscopic images with our modeling and inference framework.
Password based authentication: Philosophical survey (2010)

The security of many computer systems hinges on the secrecy of a single word - if an adversary obtains knowledge of a password, they will gain access to the resources controlled by this password. For the vast majority of computer systems, passwords are the method of choice for authenticating users. The most widely and commonly used authentication is traditional “Username” and “Password”. Among the various means of available resource protection including biometrics, password based system is most simple, user friendly, cost effective and commonly used. But this method having high sensitivity with attacks. Most of the advanced methods for authentication based on password encrypt the contents of password before storing or transmitting in physical domain. In this paper we are giving such authentication credential to various techniques which is used in password based authentication and giving the techniques for prevention of password attacks.
Introduction (2003)

The idea for this book came from our recognition, as teachers and researchers in the field of social care, of the range of situations in which practitioners become involved in working with families, and the substantial developments which have taken place in this work in the last decade. Equally, we were conscious that despite specialist books on particular methods of intervention (approaches to family therapy being the most obvious) we lacked a book which would bring together policy and practice accounts of these different approaches and place them within a framework of developments in contemporary family policy. The present edited book is an attempt to fill this gap.
Evaluation of video sequence indexing and hierarchical video indexing (1995)

As a first step to creating a video database, a video sequence has to be segmented into several subsequences based on significant changes in the scene. This enables the media user to identify the whole or a part of the sequence and to retrieve scenes of interest from a large video database. Researchers in the past have used a histogram based inter-frame difference approach to identify significant scene changes. To determine which is the best color coordinate system for video indexing, we have evaluated the histogram based indexing method using different color coordinate systems -- RGB, HSV, YIQ, L*a*b*, L*u*v* & Munsell -- and compared the results for accuracy of indexing with reference to subjective indexing. Since it is difficult to determine the exact threshold value to obtain reasonably good results, we also propose a vide segmenting method called hierarchical histogram based indexing that segments a video sequence into several levels of subsequences using different levels of threshold.
The herbicidally active experimental compound Hoe 704 is a potent inhibitor of the enzyme acetolactate reductoisomerase (1988)

Growth inhibition of plants and bacteria by the experimental herbicide Hoe 704 (2-methylphosphinoyl-2-hydroxyacetic acid) was alleviated by the addition of the branched-chain amino acids to growth media. Hoe 704 caused a massive accumulation of acetoin and acetolactate, indicating its direct interference with the branched-chain amino acid biosynthetic pathway. The second enzyme of this pathway, acetolactate reductoisomerase (EC 1.1.1.86), was found to be subject to strong inhibition by Hoe 704. The inhibition was time-dependent and competitive with the enzyme's substrate, acetolactate. This report establishes acetolactate reductoisomerase as a new target for a herbicidal compound.
Comparison of Innovative Molecular Approaches and Standard Spore Assays for Assessment of Surface Cleanliness (2011)

A bacterial spore assay and a molecular DNA microarray method were compared for their ability to assess relative cleanliness in the context of bacterial abundance and diversity on spacecraft surfaces. Colony counts derived from the NASA standard spore assay were extremely low for spacecraft surfaces. However, the PhyloChip generation 3 (G3) DNA microarray resolved the genetic signatures of a highly diverse suite of microorganisms in the very same sample set. Samples completely devoid of cultivable spores were shown to harbor the DNA of more than 100 distinct microbial phylotypes. Furthermore, samples with higher numbers of cultivable spores did not necessarily give rise to a greater microbial diversity upon analysis with the DNA microarray. The findings of this study clearly demonstrated that there is not a statistically significant correlation between the cultivable spore counts obtained from a sample and the degree of bacterial diversity present. Based on these results, it can be stated that validated state-of-the-art molecular techniques, such as DNA microarrays, can be utilized in parallel with classical culture-based methods to further describe the cleanliness of spacecraft surfaces.
A fault-tolerant 64K dynamic random-access memory (1979)

A 64K dynamic MOS RAM with features and performance fully compatible with current 16K RAM's has been designed and characterized. The memory cell is a one-transistor-one-capacitor structure, standard except for a polysilicon bit line. A dual-32K architecture, along with partial selection and stepped recovery, holds power and peak current values below those of 16K parts. Spare rows and columns, which can be substituted for defective elements by the laser opening of polysilicon links, enhance yield. Worst case column enable access time of the memory is 100 ns, row enable access time is 170 ns, and only 128 cycles within 4 ms are needed to refresh the device.
Immunization with the<i>Chlamydia trachomatis</i>Mouse Pneumonitis Major Outer Membrane Protein Can Elicit a Protective Immune Response against a Genital Challenge (2001)

Infertility, ectopic pregnancy, and chronic abdominal pain are frequent complications of genital infections with Chlamydia trachomatis. In an attempt to produce a vaccine to protect against this pathogen we purified and refolded the C. trachomatis mouse pneumonitis (MoPn) major outer membrane protein (MOMP). This preparation, mixed with Freund's adjuvant using vortexing or sonication, was used to immunize BALB/c mice that were subsequently challenged in the upper genital tract. Vaginal cultures were taken on a weekly basis, and mice were mated 6 weeks after the challenge. Gels of the vortexed MOMP showed a predominant band with a molecular size of 62 kDa and weaker bands at 42 and 132 kDa, while the sonicated MOMP had a single band with a molecular size of 42 kDa. Following immunization with these two preparations, strong humoral and cell-mediated immune responses were detected in the mice inoculated with the vortexed MOMP. On the other hand, mice immunized with the sonicated MOMP had a strong humoral immune response but a relatively weak cell-mediated immune response, as determined by a T-cell lymphoproliferative assay and level of cytokine production by splenocytes. Vaginal cultures showed that the mice immunized with the vortexed MOMP were significantly protected, as determined by a decrease in the number of animals with positive cultures, the length of time the mice shed viable organisms, and the number of inclusion-forming units recovered per mouse. Animals immunized with the sonicated MOMP, on the other hand, showed a weaker level of protection based on the same three parameters. After mating, the number of fertile animals and number of embryos per mouse were significantly higher for the mice immunized with vortexed MOMP, but not for the mice immunized with sonicated MOMP, compared to those of the control groups. In conclusion, immunization with a purified and refolded preparation of the C. trachomatis MoPn MOMP confers a significant level of protection in mice against a genital challenge.
The Manastash Ridge radar: A passive bistatic radar for upper atmospheric radio science (1997)

We describe a novel method for radar remote sensing of the upper atmosphere which relies upon commercial FM broadcasts near 100 MHz. These broadcasts have high average power and excellent radar ambiguity function. With proper processing we can study the spatial and temporal distribution and Doppler spectrum with excellent and completely unambiguous resolution. Since this passive system has no transmitter, there are enormous benefits in safety, expense, shielding, antenna and receiver design, and licensing issues. Some new problems are introduced, but these are solved with relatively little expense. After presenting the technical basis for such a radar, we describe an instrument that we are building at the University of Washington to study high‐latitude plasma irregularities in the E region.
Characterization of Polypeptides that Accumulate in Cultured <italic>Nicotiana tabacum</italic> Cells (1990)

We characterized the polypeptides that accumulate in photoautotrophically cultured cells of tobacco. Microsequencing of these polypeptides accumulated in large amounts revealed four NH2-terminal amino acid sequences that were highly homologous to those of the known stress proteins, osmotin and chitinase. Further analyses of our tobacco cell line grown with sucrose in light and in darkness, as well as analyses of newly established cultured cells and regenerating adventitious shoots, clearly showed that all the in vitro cultured cells accumulated these stress proteins. The accumulation of these proteins were also observed in old leaves, roots, and leaves infected with Tobacco Mosaic Virus, but not in young healthy leaves.
Dipole-dipole interaction between a quantum dot and a graphene nanodisk (2012)

We study theoretically the dipole-dipole interaction and energy transfer in a hybrid system consisting of a quantum dot and graphene nanodisk embedded in a nonlinear photonic crystal. In our model, a probe laser field is applied to measure the energy transfer between the quantum dot and graphene nanodisk, while a control field manipulates the energy transfer process. These fields create excitons in the quantum dot and surface plasmon polaritons in the graphene nanodisk which interact via the dipole-dipole interaction. Here, the nonlinear photonic crystal acts as a tunable photonic reservoir for the quantum dot, and is used to control the energy transfer. We have found that the spectrum of power absorption in the quantum dot has two peaks due to the creation of two dressed excitons in the presence of the dipole-dipole interaction. The energy transfer rate spectrum of the graphene nanodisk also has two peaks due to the absorption of these two dressed excitons. Additionally, energy transfer between the quantum dot and the graphene nanodisk can be switched on and off by applying a pump laser to the photonic crystal or by adjusting the strength of the dipole-dipole interaction. We show that the intensity and frequencies of the peaks in the energy transfer rate spectra can be modified by changing the number of graphene monolayers in the nanodisk or the separation between the quantum dot and graphene. Our results agree with existing experiments on a qualitative basis. The principle of our system can be employed to fabricate nanobiosensors, optical nanoswitches, and energy transfer devices.
High throughput downlink cellular packet data access with multiple antennas and multiuser diversity (2004)

This paper presents a discussion of MIMO (multiple-input multiple-output) system designed to exploit multiuser diversity, with the principal goal of increasing throughput of delay tolerant data services to nomadic and mobile users in cellular systems. We consider the downlink of a cellular packet data access scheme with a base station transmit antenna array and users equipped with a single receive antenna. We show that it can be preferable to transmit to several users simultaneously using the transmit antenna array even with sub-optimal signaling. This is in contrast to single antenna systems exploiting multiuser diversity and using link adaptation, in which the average throughput per sector is maximized, when in any packet time slot transmission occurs only to one user experiencing the best channel conditions at the time. We propose several scheduling algorithms and compare their performance to the throughput achievable with precoding and perfect channel state information at the transmitter. We show that the capacity scaling typical to MIMO systems can be achieved even with single-antenna mobile receivers, but only a fraction of that capacity can be achieved with limited channel knowledge at the transmitter, when multiuser diversity is exploited.
Metal Ion Separations in Polyethylene Glycol-Based Aqueous Biphasic Systems (1993)

Abstract Aqueous biphasic systems of two dissimilar polymers, or of a water-soluble polymer and an inorganic salt, can be used to selectively partition metal ions. While these systems are well known for separating biomaterials, only a handful of papers have appeared investigating their utility for separating metal ions. The few results that have appeared in the literature have utilized salt solutions of polyethylene glycol (PEG) and fall into two categories: 1) partitioning of the metal ion to the PEG-rich phase by the addition of a water-soluble extractant which coordinates the metal ion and 2) addition of an inorganic anion which produces a metal complex that partitions to the PEG-rich phase. In addition the authors have recently added a third category: 3) partitioning of a metal ion directly from the salt-rich to the PEG-rich phase without an added component. It appears that a separations strategy can be developed for metal ions from all areas of the periodic table under a wide variety of conditions. This review covers papers published concerning metal ion separations in aqueous biphasic systems and unpublished work of the authors. The incredible potential of this area for future research is discussed.
A Highly Linear Wideband Polar Class-E CMOS Digital Doherty Power Amplifier (2019)

This article presents the first application of a digital-intensive intrinsically linear digitally controlled class-E technique in a Doherty configuration. By careful nonlinear segmentation and multiphase RF-clocking along with overdrive-voltage control and automatic duty-cycle correction, it is shown that even the nonlinearities related to Doherty operation can be fully handled by the underlying design such that digital predistorion (DPD) can be, in principle, omitted. The nonlinearity behavior of the whole digital Doherty power amplifier (PA) is analyzed, and closed-form equations are given to predict the AM-AM and AM-phase modulation (PM) curves. In addition, time/phase mismatch between the peak and main branches and the AM and PM signals is accurately compensated. In order to achieve the maximum intrinsic linearity, two separate chips with the same architecture, but different design parameters, are fabricated as the main and peak amplifiers in 40-nm bulk CMOS. To achieve a large RF bandwidth and high passive combiner efficiency, a differential low-loss, wideband Marchand balun-based Doherty power combiner, implemented using reentrant coupled lines with independent second-harmonic control is proposed, and together with the matching network is fabricated on a two-layer PCB. The measured peak/6-dB power backoff P <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">OUT</sub> , drain efficiency/power-added efficiency at 2.4 GHz are 17.5 dBm/12.2 dBm, 57%/52% and 36%/25% with VDD main/peak = 0.6 V/0.7 V. Measured results without using DPD show -41-dBc adjacent channel power ratio (ACPR) and -36-dB error vector magnitude (EVM) for a 16-MHz OFDM signal at 2.5 GHz. By using DPD, the measured ACPR and EVM of a 16-MHz /32-MHz OFDM signals are -52 dBc/-48 dBc and -50 dB/-48 dB, respectively.
Chemical Modification of Tyrosine Residues in Ribonuclease T1 with N-Acetylimidazole and p-Diazobenzenesulfonic Acid1 (1977)

The reactions of ribonuclease T1 [EC 3.1.4.8] with N-acetylimidazole and p-diazobenzenesulfonic acid have been investigated to obtain some information on the states and roles of tyrosine residues in the enzyme. Three to four tyrosine residues in the enzyme were acetylated with N-acetylimidazole fairly readily at pH 7.5 without extensive loss of activity toward RNA. Of these, two residues appeared to be acetylated most easily. In the presence of phosphate anion, however, the reactivity of N-acetylimidazole was significantly lowered. Under the reaction conditions used, no acetylation took place in 0.2 m phosphate buffer. On the other hand, one to two tyrosine residues were modified with p-diazobenzenesulfonic acid in 0.2 m phosphate buffer, pH 7.0, without much loss of activity. In 8 M urea all the tyrosine residues were acetylated with nearly complete loss of activity. These results indicated that at least two tyrosine residues are fully exposed while most of the remaining seven tyrosine residues are buried inside the molecule. Judged from the change in CD spectrum, some conformational change appeared to have already occurred when two tyrosine residues were acetylated. Upon removal of all the acetyl groups introduced by incubation with hydroxylamine, the fully acetylated, inactive enzyme regained full activity, although the original native structure did not appear to be completely regenerated from CD spectrum measurements. These results indicated that several of the tyrosine residues in ribonuclease T1 are important in the formation and maintenance of the enzymatically active conformation although they are presumably not directly involved in the active site.
Oxidative stress in malaria and artemisinin combination therapy: Pros and Cons (2017)

Artemisinin-based combination therapy (ACT) has been adopted as a strategy to mitigate multidrug resistance to antimalarial monotherapies. ACT combines the rapid and effective but rather short plasma half-life antimalarial action of an artemisinin derivative with a longer acting partner drug. Although the exact mechanisms of action of artemisinins are not well understood, several studies have proposed multiple cellular targets of artemisinins with involvement of reactive oxygen species (ROS). Most of the currently used ACT partner drugs are also known to involve ROS production in their mechanisms of action. This review gives a brief account of the oxidative stress and redox systems in malaria and discusses the context of antimalarial effectiveness of different ACTs compared with monotherapies of the partner drugs. A final account on the Pros and Cons of ACT as a strategy is discussed.
Eye blink based fatigue detection for prevention of Computer Vision Syndrome (2009)

Living in information society we spend a lot of time in front of visual display units such as computer monitors or TV screens. This has positive as well as negative effects on our lives. Negative effects are mostly health related and one major concern is the increasing number of people affected by the Computer Vision Syndrome (CVS) [1]. Most CVS-related problems can be avoided by suitable preventive actions, but the majority of computer users ignore them. To help remedy the situation we present a prototype of a computer vision system for real-time eye blink based detection of eye fatigue, which is a common symptom leading towards CVS. Our program records video of the user by a computer monitor mounted web-camera, processes the frames and detects hazardous behaviour based on user’s eye dynamics and blink patterns. Experimental results show that the proposed system is capable of detecting common cases of fatigued behaviour linked with long-term computer use. We believe regular use of the proposed system could significantly reduce the CVS symptoms for long-time computer workers. However, the techniques used can also be applied to other similar applications, such as driver fatigue detection, human-computer interaction, etc.
Effect of Leflunomide and Cidofovir on Replication of BK Virus in an In Vitro Culture System (2004)

The in vitro activity of Cidofovir and Leflunomide is modest, and the selectivity index is low. There is a need to develop more effective and less toxic anti-BK virus drugs for clinical use.
Dynamics of COVID-19: Modelling and Analysis (2020)

The paper features the SEIR model that can accurately calculate and predict the size of COVID-19 pandemic. Other than classical parameters, the model takes into account lockdown imposed by the government, age composition of the population, testing rate, inflow of patients (immigrants) and availability of tertiary health care facilities measured in terms of number of ICUs.
The role of chordin/Bmp signals in mammalian pharyngeal development and DiGeorge syndrome (2003)

The chordin/Bmp system provides one of the best examples of extracellular signaling regulation in animal development. We present the phenotype produced by the targeted inactivation of the chordin gene in mouse. Chordin homozygous mutant mice show, at low penetrance, early lethality and a ventralized gastrulation phenotype. The mutant embryos that survive die perinatally, displaying an extensive array of malformations that encompass most features of DiGeorge and Velo-Cardio-Facial syndromes in humans. Chordin secreted by the mesendoderm is required for the correct expression of Tbx1 and other transcription factors involved in the development of the pharyngeal region. The chordin mutation provides a mouse model for head and neck congenital malformations that frequently occur in humans and suggests that chordin/Bmp signaling may participate in their pathogenesis.