Miracle-dz/UniFAR-FTUs huggingface dataset:
Optimized new ADC architecture using ΣΔ modulators for nonlinearly distorted signals

In this paper, a new ADC architecture using bandpass ΣΔ modulators is proposed. It uses the novel concept of residual signal transfer function (RSTF) and of noise band cancellation to digitize nonlinearly distorted signals such as RF power amplifiers outputs. Mathematical analysis and system simulations show the validity of these concepts. We also present a high level design methodology to optimize the actual peak signal-to-noise and the stability of ΣΔ modulators. We provide the result of extensive simulations to help the design of such a converter.
Crystal Structures of Klebsiella pneumoniae Dihydrofolate Reductase Bound to Propargyl-Linked Antifolates Reveal Features for Potency and Selectivity

ABSTRACT Resistance to the antibacterial antifolate trimethoprim (TMP) is increasing in members of the family Enterobacteriaceae, driving the design of next-generation antifolates effective against these Gram-negative pathogens. The propargyl-linked antifolates are potent inhibitors of dihydrofolate reductases (DHFR) from several TMP-sensitive and -resistant species, including Klebsiella pneumoniae. Recently, we have determined that these antifolates inhibit the growth of strains of K. pneumoniae, some with MIC values of 1 μg/ml. In order to further the design of potent and selective antifolates against members of the Enterobacteriaceae, we determined the first crystal structures of K. pneumoniae DHFR bound to two of the propargyl-linked antifolates. These structures highlight that interactions with Leu 28, Ile 50, Ile 94, and Leu 54 are necessary for potency; comparison with structures of human DHFR bound to the same inhibitors reveal differences in residues (N64E, P61G, F31L, and V115I) and loop conformations (residues 49 to 53) that may be exploited for selectivity.
Detailed structure of the outer disk around HD 169142 with polarized light in H-band

Coronagraphic imagery of the circumstellar disk around HD 169142 in H-band polarized intensity (PI) with Subaru/HiCIAO is presented. The emission scattered by dust particles at the disk surface in 0.2r1. 2, or 29r174 AU, is successfully detected. The azimuthally-averaged radial profile of the PI shows a double power-law distribution, in which the PIs in r = 2952 AU and r = 81.2145 AU respectively show r3-dependence. These two power-law regions are connected smoothly with a transition zone (TZ), exhibiting an apparent gap in r = 4070 AU. The PI in the inner power-law region shows a deep minimum whose location seems to coincide with the point source at lambda = 7 mm. This can be regarded as another sign of a protoplanet in TZ. The observed radial profile of the PI is reproduced by a minimally flaring disk with an irregular surface density distribution or with an irregular temperature distribution or with the combination of both. The depletion factor of surface density in the inner power-law region (r <50 AU) is derived to be 0.16 from a simple model calculation. The obtained PI image also shows small scale asymmetries in the outer power-law region. Possible origins for these asymmetries include corrugation of the scattering surface in the outer region, and shadowing effect by a puffed up structure in the inner power-law region.
Peking University at the TREC 2006 Terabyte Track

paper details the experiments carried out at TREC 2006 Terabyte Track using Indri Search Engine. There were three tasks in the Terabyte track of TREC 2006, i.e. efficiency task, ad hoc task and named page finding task. We participated in two tasks, and submitted 5 runs for ad hoc task and 3 runs for named page task respectively. In ad hoc task, we looked at the importance of term proximity. In named page finding task, we cared more about the information of document structure and document prior.
Water Oxidation Catalysis by Synthetic Manganese Oxides with Different Structural Motifs: A Comparative Study.

Manganese oxides are considered to be very promising materials for water oxidation catalysis (WOC), but the structural parameters influencing their catalytic activity have so far not been clearly identified. For this study, a dozen manganese oxides (MnOx ) with various solid-state structures were synthesised and carefully characterised by various physical and chemical methods. WOC by the different MnOx was then investigated with Ce(4+) as chemical oxidant. Oxides with layered structures (birnessites) and those containing large tunnels (todorokites) clearly gave the best results with reaction rates exceeding 1250 ${{\rm{mmol}}_{{\rm{O}}_{\rm{2}} } }$ ${{\rm{mol}}_{{\rm{Mn}}}^{ - 1} }$ h(-1) or about 50 μmolO2 m(-2) h(-1) . In comparison, catalytic rates per mole of Mn of oxides characterised by well-defined 3D networks were rather low (e.g., ca. 90 ${{\rm{mmol}}_{{\rm{O}}_{\rm{2}} } }$ ${{\rm{mol}}_{{\rm{Mn}}}^{ - 1} }$ h(-1) for bixbyite, Mn2 O3 ), but impressive if normalised per unit surface area (>100 ${{\rm{{\rm \mu} mol}}_{{\rm{O}}_{\rm{2}} } }$ m(-2) h(-1) for marokite, CaMn2 O4 ). Thus, two groups of MnOx emerge from this screening as hot candidates for manganese-based WOC materials: 1) amorphous oxides with tunnelled structures and the well-established layered oxides; 2) crystalline Mn(III) oxides. However, synthetic methods to increase surface areas must be developed for the latter to obtain good catalysis rates per mole of Mn or per unit catalyst mass.
A statistical method for flagging weak spots improves normalization and ratio estimates in microarrays.

Over the last few years, there has been a dramatic increase in the use of cDNA microarrays to monitor gene expression changes in biological systems. Data from these experiments are usually transformed into expression ratios between experimental samples and a common reference sample for subsequent data analysis. The accuracy of this critical transformation depends on two major parameters: the signal intensities and the normalization of the experiment vs. reference signal intensities. Here we describe and validate a new model for microarray signal intensity that has one multiplicative variation and one additive background variation. Using replicative experiments and simulated data, we found that the signal intensity is the most critical parameter that influences the performance of normalization, accuracy of ratio estimates, reproducibility, specificity, and sensitivity of microarray experiments. Therefore, we developed a statistical procedure to flag spots with weak signal intensity based on the standard deviation (delta(ij)) of background differences between a spot and the neighboring spots, i.e., a spot is considered as too weak if the signal is weaker than cdelta(ij). Our studies suggest that normalization and ratio estimates were unacceptable when this threshold (c) is small. We further showed that when a reasonable compromise of c (c = 6) is applied, normalization using trimmed mean of log ratios performed slightly better than global intensity and mean of ratios. These studies suggest that decreasing the background noise is critical to improve the quality of microarray experiments.
Comparison of one-tube multiplex PCR, automated ribotyping and intergenic spacer (ITS) sequencing for rapid identification of Acinetobacter baumannii.

Acinetobacter baumannii has emerged as a serious cause of nosocomial infections. Rapid identification of this pathogen is required so that appropriate therapy can be given and outbreaks controlled. This study evaluated a multiplex PCR and an automated ribotyping system for the rapid identification of Acinetobacter baumannii. In total, 22 different reference strains and 138 clinical isolates of Acinetobacter spp. , identified by 16S-23S rRNA intergenic spacer (ITS) sequence analysis, were evaluated. All A. baumannii isolates (82 clinical isolates and one reference strain) were identified by the multiplex PCR method (specificity 100%). The sensitivity and specificity of the ribotyping system for identification of A. baumannii were 85.5% (71/83) and 93.5% (72/77), respectively. An additional 100 clinical isolates belonging to the Acinetobacter calcoaceticus-A. baumannii complex were used to compare these two methods for identification of A. baumannii, and this comparison revealed a level of disagreement of 14% (14 isolates). The accuracy of the multiplex PCR was 100%, which was confirmed by sequence analysis of the ITS and recA gene of these isolates. Thus, the multiplex PCR method dramatically increased the efficiency and speed of A. baumannii identification.
Reduced Capacity to Produce Specific ‘Effector’ Cells after Injection of CBA Mice with C3H Cells

Lymphocytes from mice of strain CBA are strongly MLC‐responsive to lymphocytes from the H‐2 compatible‐ but M‐antigen‐incompatible strain C3H. This strong reactivity disappears after infusion of CBA mice with C3H lymphocytes. This study shows that the host‐versus‐graft reactivity (swelling of local lymph node after antigen injection) is specifically reduced after injection of CBA mice with C3H × CBA spleen cells However, lymphocytes from such mice showed a specifically increased GVH reactivity (inhibition of erythroid cell growth) compared with lymphocytes from unimmunized mice. Lymphocytes from normal CBA mice showed a high proliferative rate in the spleens of irradiated C3H × CBA mice. Such ‘educated’ cells showed strongly increased specific GVH reactivity. Lymphocytes from CBA mice previously injected with C3H×CBA cells showed reduced capacity to proliferate when injected into irradiated C3H × CBA hybrids and a poor capacity to develop new ‘effector’ cells reactive against C3H × CBA bone marrow target cells. The results indicate that the presence of specifically ‘MLC responsive’ lymphocytes in a lymphoid cell population is a prerequisite of its production of ‘effector’ cells able to respond in this GVH assay
The choice of home blood pressure result reporting method is essential: Results mailed to physicians did not improve hypertension control compared with ordinary office-based blood pressure treatment

Abstract Effective antihypertensive care is not possible without regular and reliable blood pressure measurements. The use of blood pressure home measurement has increased a lot during the last years. Various methods have been used in communication between the patients and physicians. In a randomized study we compared traditional office-based hypertension treatment protocol (n=68) to the home-based blood pressure measurement protocol (n=89) in which the patient mailed their home-measured BP diary in a letter to the office of their physician. The studied home-based antihypertensive care system was not more effective than the ordinary office-based treatment. The results highlight the importance of continuous home measurement data interpretation by the physician. The system based on mailing the results to the physician office does not seem to be a suitable method in communication between the patient and the physician. Online or other telemedicine-aided means of communication might yield better antihypertensive control.
Yvonne Dittrich, Christiane Floyd, and Ralf Klischewski, Eds. Social thinking-software practice

Book Publisher: Cambridge, MA: Massachusetts Institute of Technology Press, 2002 481 pp., with indexes and references in each chapter. This book addresses the design, development, and use of software, integrating both a social sciences and a software engineering perspective, rather than presenting two parallel discourses. This approach overcomes the problems associated with leaving the integration to the pre-existing skills of readers in a fundamentally difficult task. As such, this book is immensely interesting, both to read and to use as a reference. The book consciously alludes to the title of Checkland’s influential work, Systems Thinking, Systems Practice [1], and is a work worthy to bear a title making this allusion.
Advertising and consumer choice : A model for the Spanish automobile industry of the 90 ́ s

This paper assesses the role of advertising in the demand of a differenciated and infrequently purchased good market. Advertising enters directly in the demand as goodwill stock with decreasing returns. Demand is specified and estimated in a discrete choice model approach, which allows us to compute the predatory and spillover effects of advertising and different sensibilities to advertising across market segments. The model is applied to the Spanish automobile industry during the nineties, that turns out to be a suitable environment to perform the study (differentiated good market with high advertising intensity). Results suggest an important sensibility of the demand to advertising, that changes across automobile segments, and a significant carryover effect and a predatory component of advertising. Moreover,I show that the price eslasticies of demand are overestimated when advertising is not included in the estimation. Key word: Advertising, Discrete Choice Model, Differentiated and Infrequently Purchased Good Market, Spillover and Predatory Effect, Stock of Goodwill. JEL Classification: M37, L13. The paper is competing to the Young Economist Award. ∗E-mail: abarroso@cemfi.es
Effect of ouabain on glycerol-extracted fibers from heart containing a "relaxing factor".

Heart muscle fibers extracted at -20°C in 50% glycerol with 0.1 M histidine buffer at pH 7.00 for a short duration (approximately 3 to 15 days) were found to contain a "relaxing factor. " This "relaxing factor" was not present in fibers extracted or preincubated for a prolonged time (over 3 weeks). Ouabain increased the ATP-induced contraction of these glycerol-extracted fibers containing the "relaxing factor. " This action of ouabain occurred only after a 20-minute contact with the fiber. This effect of ouabain was not seen when the "relaxing factor" was absent from the fibers. Thus ouabain was effective only in those fibers which contracted in response to Ca++.
Mutational analysis of the hepatitis C virus RNA helicase

The carboxyl-terminal three-fourths of the hepatitis C virus (HCV) NS3 protein has been shown to possess an RNA helicase activity, typical of members of the DEAD box family of RNA helicases. In addition, the NS3 protein contains four amino acid motifs conserved in DEAD box proteins. In order to inspect the roles of individual amino acid residues in the four conserved motifs (AXXXXGKS, DECH, TAT, and QRRGRTGR) of the NS3 protein, mutational analysis was used in this study. Thirteen mutant proteins were constructed, and their biochemical activities were examined. Lys1235 in the AXXXXGKS motif was important for basal nucleoside triphosphatase (NTPase) activity in the absence of polynucleotide cofactor. A serine in the X position of the DEXH motif disrupted the NTPase and RNA helicase activities. Alanine substitution at His1318 of the DEXH motif made the protein possess high NTPase activity. In addition, we now report inhibition of NTPase activity of NS3 by polynucleotide cofactor. Gln1486 was indispensable for the enzyme activity, and this residue represents a distinguishing feature between DEAD box and DEXH proteins. There are four Arg residues in the QRRGRTGR motif of the HCV NS3 protein, and the second, Arg1488, was important for RNA binding and enzyme activity, even though it is less well conserved than other Arg residues. Arg1490 and Arg1493 were essential for the enzymatic activity. As the various enzymatic activities were altered by mutation, the enzyme characteristics were also changed.
Vegfd modulates both angiogenesis and lymphangiogenesis during zebrafish embryonic development

ABSTRACT Vascular endothelial growth factors (VEGFs) control angiogenesis and lymphangiogenesis during development and in pathological conditions. In the zebrafish trunk, Vegfa controls the formation of intersegmental arteries by primary angiogenesis and Vegfc is essential for secondary angiogenesis, giving rise to veins and lymphatics. Vegfd has been largely thought of as dispensable for vascular development in vertebrates. Here, we generated a zebrafish vegfd mutant by genome editing. vegfd mutants display significant defects in facial lymphangiogenesis independent of vegfc function. Strikingly, we find that vegfc and vegfd cooperatively control lymphangiogenesis throughout the embryo, including during the formation of the trunk lymphatic vasculature. Interestingly, we find that vegfd and vegfc also redundantly drive artery hyperbranching phenotypes observed upon depletion of Flt1 or Dll4. Epistasis and biochemical binding assays suggest that, during primary angiogenesis, Vegfd influences these phenotypes through Kdr (Vegfr2) rather than Flt4 (Vegfr3). These data demonstrate that, rather than being dispensable during development, Vegfd plays context-specific indispensable and also compensatory roles during both blood vessel angiogenesis and lymphangiogenesis. Summary: VEGFD has been considered dispensable for vascular development in vertebrates. Its mutation reveals that Vegfd plays context-specific and compensatory roles during both angiogenesis and lymphangiogenesis.
A modern Green Revolution gene for reduced height in wheat

Increases in the yield of wheat during the Green Revolution of the late 20th century were achieved through the introduction of Reduced height (Rht) dwarfing genes. The Rht-B1 and Rht-D1 loci ensured short stature by limiting the response to the growth-promoting hormone gibberellin, and are now widespread through international breeding programs. Despite this advantage, interference with the plant's response to gibberellin also triggers adverse effects for a range of important agronomic traits, and consequently modern Green Revolution genes are urgently required. In this study, we revisited the genetic control of wheat height using an association mapping approach and a large panel of 1110 worldwide winter wheat cultivars. This led to the identification of a major Rht locus on chromosome 6A, Rht24, which substantially reduces plant height alone as well as in combination with Rht-1b alleles. Remarkably, behind Rht-D1, Rht24 was the second most important locus for reduced height, explaining 15.0% of the genotypic variance and exerting an allele substitution effect of -8.8 cm. Unlike the two Rht-1b alleles, plants carrying Rht24 remain sensitive to gibberellic acid treatment. Rht24 appears in breeding programs from all countries of origin investigated, with increased frequency over the last decades, indicating that wheat breeders have actively selected for this locus. Taken together, this study reveals Rht24 as an important Rht gene of commercial relevance in worldwide wheat breeding.
Influence of Orbit and System Parameters on Geosynchronous SAR Multiple-Aperture Interferometry Processing: Analysis and Validation

A geosynchronous synthetic aperture radar (GEO SAR) can achieve a shorter revisit time, a longer observation time, and a larger coverage area for the target scene compared with low earth orbit (LEO) SARs. Therefore, its combination with the multiple-aperture interferometry (MAI) technique can allow along-track deformation measurements with better performance. Nevertheless, because the orbit and system parameters determine the MAI measuring geometry, their influence on the accuracy of such deformation measurements should be extensively studied. In this paper, based on theoretical deductions and simulations, the performance of GEO SAR MAI processing in along-track deformation measurements is discussed considering the orbit and system parameters. The optimal along-track deformation accuracy (OADA) was introduced for quantitative performance evaluations. Finally, a repeat-track global navigation satellite system-based SAR MAI experiment, implemented with a transponder onboard displacement device on the ground and BeiDou-2 inclined geosynchronous orbit satellites, was conducted to verify the effectiveness of the proposed method and its validating analysis. The results suggested that the OADA could be improved by decreasing the azimuth antenna size or the ratio between the averaged velocities of beam footprint and satellite, mainly depending on the inclination, eccentricity, and look angle.
Position Prediction Based Frequency Control of Beacons in Vehicular Ad Hoc Networks

In VANETs, frequent beacon broadcasting can lead to high bandwidth consumption and channel congestion. In this paper, a position prediction based beacon approach is proposed to reduce beacon frequency and decrease bandwidth consumption. Vehicles track their neighbors using the predicted position instead of using periodic beacon broadcasting. Only when the prediction error is higher than a predefined tolerance will a beacon broadcasting be triggered. For improving the prediction accuracy, we classify the motion of vehicles into two typical patterns: a constant speed pattern and a maneuvering pattern. A maneuver detection module is responsible for recognizing current motion patterns, and a variable dimension filter that can switch dynamically between the two patterns is employed to generate high accurate position prediction. The simulation results show the proposed scheme can reduce significantly the number of beacons than three existing beacon approaches.
Reduced-Complexity PAPR Minimization Schemes for MC-CDMA Systems

Multicarrier Code-Division Multiple Access (MC-CDMA) (Hara & Prasad, 1997), which is based on a combination of an CDMA scheme and Orthogonal Frequency Division Multiplexing (OFDM) signaling (Fazel & Kaiser, 2008), has attracted much attention in forthcoming mobile communication systems, because of its intrinsic spectrum efficiency and interference suppression capabilities. In MC-CDMA, information symbols of many users are spread using orthogonal codes and combined in the frequency domain; this results in a relatively low symbol rate and thus non-selective fading in each subcarrier. However, one main drawback of any kind of multicarrier modulation is the inherent high value of the Peak-to-Average Power Ratio (PAPR) of the transmitted signals, because they are generated as an addition of a large number of independent signals. If low power consumption at the transmitter is a strict requirement, one would like the RF High Power Amplifier (HPA) to operate with a low back-off level (i.e. with operation point near saturation state); as a consequence of this, signal peaks will frequently enter the nonlinear part of the input-output characteristic of the HPA, thus causing severe nonlinear artifacts on the transmitted signals such as intermodulation distortion and out-of-band radiation. Therefore, reducing the PAPR is crucial in multicarrier systems, especially when transceivers are fed by batteries (such as in mobile devices), because of the intrinsic limitations in power consumption. There has been a lot of research work about PAPR reduction techniques in multicarrier systems. Among these, we have clipping and filtering schemes (Li & Cimini, 1997), block coding algorithms (Jones et al., 1994), the Partial Transmit Sequences (PTS) (Cimini & Sollenberger, 2000; Jayalath & Tellambura, 2000), and Selected Mapping (SLM) approaches (Bauml et al., 1996; Breiling et al., 2001), and the Tone Reservation (TR) (Tellado & Cioffi, 1998), and the Tone Injection (TI) techniques (Han et al., 2006). In general, reducing the PAPR is always done either at the expense of distorting the transmitted signals, thus increasing the BER at the receiver, or by reducing the information data rate, usually because high PAPR signals are somehow discarded and replace by others with lower PAPR before been transmitted. All the previously mentioned methods have been originally proposed for single-user multicarrier schemes such as OFDM. Although most of them are also applicable with minor modifications to MC-CDMA systems (Ruangsurat & Rajatheva, 2001; Ohkubo & Ohtsuki, 2002), other families of algorithms can be developed after carefully considering the different