3-D reconstruction of 2-D crystals in real space

A new algorithm for three-dimensional reconstruction of two-dimensional crystals from projections is presented, and its applicability to biological macromolecules imaged using transmission electron microscopy (TEM) is investigated. Its main departures from the traditional approach is that it works in real space, rather than in Fourier space, and it is iterative. This has the advantage of making it convenient to introduce additional constraints (such as the support of the function to be reconstructed, which may be known from alternative measurements) and has the potential of more accurately modeling the TEM image formation process. Phantom experiments indicate the superiority of the new approach even without the introduction of constraints in addition to the projection data.     

oriGNAI3: a narrow zone of preferential replication initiation in mammalian cells identified by 2D gel and competitive PCR replicon mapping techniques

The nature of mammalian origins of DNA replication remains controversial and this is primarily because two-dimensional gel replicon mapping techniques have identified broad zones of replication initiation whereas several other techniques, such as quantitative PCR, have disclosed more discrete sites of initiation at the same chromosomal loci. In this report we analyze the replication of an amplified genomic region encompassing the 3'-end of the GNAI3 gene, the entire GNAT2 gene and the intergenic region between them in exponentially growing Chinese hamster fibroblasts. These cells express GNAI3 but not GNAT2 . The replication pattern was first analyzed by two-dimensional neutral-alkaline gel electrophoresis. Surprisingly, the results revealed a small preferential zone of replication initiation, of at most 1.7 kb, located in a limited part of the GNAI3 - GNAT2 intergenic region. Mapping of this initiation zone was then confirmed by quantitative PCR. The agreement between the two techniques exploited here strengthens the hypothesis that preferred sites of replication initiation do exist in mammalian genomes.     

Algorithm for efficient symbolic analysis of large analoguecircuits

An algorithm is presented that generates simplified symbolic expressions for the small-signal characteristics of large analogue circuits. The expressions are approximated while they are computed, so that only the most significant terms are generated which remain in the final expression. This principle leads to dramatic savings in CPU time and memory compared to existing techniques, significantly increasing the maximum size of circuits that can be analysed. By taking into account a range for the value of a circuit parameter rather than one single number the generated symbolic expressions are also generally valid     

Abandoning unrealistic optimism: Performance estimates and the temporal proximity of self-relevant feedback.

Although evidence for unrealistic optimism is considerable, there is reason to believe that individuals will abandon their optimism and may even become pessimistic in anticipation of self-relevant feedback. The authors propose and provide preliminary test of a model of the temporal transition from optimism to accuracy to pessimism in outcome predictions. In Study 1, college sophomores, juniors, and seniors estimated their likely salary at their first full-time job after graduation. Only seniors became less optimistic as graduation approached. In Study 2, students estimated their exam score a month before the exam, then again several times after completing the exam yet prior to receiving feedback. As the proximity of feedback neared, students abandoned their optimistic forecast in favor of a pessimistic forecast. Study 3 showed that, in anticipation of self-relevant feedback, participants with low self-esteem lowered their performance estimates more readily than did those with high self-esteem. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Two nuclear localization signals present in the basic-helix 1 domains of MyoD promote its active nuclear translocation and can function independently

MyoD, a member of the family of helix-loop-helix myogenic factors that plays a crucial role in skeletal muscle differentiation, is a nuclear phosphoprotein. Using microinjection of purified MyoD protein into rat fibroblasts, we show that the nuclear import of MyoD is a rapid and active process, being ATP and temperature dependent. Two nuclear localization signals (NLSs), one present in the basic region and the other in the helix 1 domain of MyoD protein, are demonstrated to be functional in promoting the active nuclear transport of MyoD. Synthetic peptides spanning these two NLSs and biochemically coupled to IgGs can promote the nuclear import of microinjected IgG conjugates in muscle and nonmuscle cells. Deletion analysis reveals that each sequence can function independently within the MyoD protein since concomittant deletion of both sequences is required to alter the nuclear import of this myogenic factor. In addition, the complete cytoplasmic retention of a beta-galactosidase-MyoD fusion mutant protein, double deleted at these two NLSs, argues against the existence of another functional NLS motif in MyoD.     

Residual soil P values for permanent pastures on reclaimed scrubland from Galicia (NW Spain).

In the reclamation of scrublands of Galicia in NW Spain, fertilization is necessary to establish pastures. The area is particularly responsive to P fertilizer. In order to maximize the efficiency of use of fertilizer in planning fertilization programs, it is necessary to take into consideration the residual as well as the freshly added P.Phosphate fertilization experiments were conducted in four sites in Galicia having a range in soil properties. The treatment design allowed estimation of residual P one year after fertilization in terms of freshly applied P equivalents.Four non-linear models were fitted to the data from the experiments after it was determined that residual soil P one year after fertilization was proportional to the amount of P applied. The estimated proportion of P remaining one year after application appeared to be independent of the model chosen. The Mitscherlich performed best from the standpoint of average residual mean squares, total rank, residual behavior after the fit and ease of fit.The percent of fresh fertilizer equivalent estimated one year after addition ranged from 60–90 for soils formed from granite, 30–60 for soils from slates, and 30 for soils over schist and gabbros.     

Intelligent Transportation Systems

This issues Works in Progress department features 10 interesting ongoing intelligent transportation systems projects. The first five projects (TIME, Sentient Transport, EVT, DynaCHINA, TrafficView) focus on traffic and vehicular data collection, transmission, and analysis. The sixth projects aims to provide intelligent-copilot services for driven, while the seventh focuses on asset identification and data collection for railroad environments. The eighth and ninth projects are budding application development environments for automobiles, and the tenth project is designing a multimodal biometric identification system for travel documents     

Intraarterial urokinase for acute native arterial occlusion of the limbs

Since 1988, 49 limbs of 47 patients underwent intraarterial urokinase infusion for acute native artery occlusion. The time from the onset of ischemic symptoms ranged from 1 to 45 days (mean = 17.5). The arterial sectors involved were femoropopliteal in 32 cases, followed by aortoiliac in 13 cases, distal in three cases, and subclavian in one case. Treatment consisted of placing a catheter in the clot and the infusion of 4400 U/kg in 20', followed by a series of 4400 U/kg weight/hour during 6 hours. Clinical evaluation, hemodynamic and coagulation parameters, and angiographical changes were assessed periodically. Infusion time ranged from 6 to 24 hours (mean = 13.2 hours). Improvement of ischemic was achieved in 43 (87.75%) patients. In five patients (12.25%) there was no improvement. Total immediate lysis was achieved in 35 cases (71.5%), and among them, 13 patients (26%) required no associated treatment, 16 (48%) underwent PTA, and four (12%) had surgery of underlying peripheral aneurysms revealed after thrombolysis. Partial lysis was achieved in 13 cases (26.5%), that was enough in four of them, but the remaining nine required further treatment (four PTA, and five arterial surgery). In one case no lysis was achieved, and arterial surgery was carried out. No mortality was recorded, and major complications included one upper gastrointestinal bleeding, and one cerebral hematoma. Late follow-up of successfully treated patients who did not require further surgery shows a cumulative patency rate of 81% at 24 months.     

Paris ham processing: Technological yield as affected by residual glycogen content of muscle

The aim of the present experiment was to study the relationships between pH, protein and residual glycogen content of pig muscle on the one hand, and technological yield (TY) of Paris ham processing on the other (Paris ham is a type of cured cooked ham). Fifty-two pigs were slaughtered at 100 kg liveweight in a commercial abattoir, in four slaughter series. Ultimate pH, protein and glycogen were determined around 24h post mortem. Two days after slaughter, the right hams were processed to Paris ham. Residual glycogen levels varied from 0 to 78 μmol/g of fresh tissue. All correlations between TY and the other traits under study were significant at the P < 0·05 level. Correlation between glycogen and TY was by far the highest one (r = 0t-0·60, P < 0·01). Protein content and both pH values gave similar but lower correlations with TY (r around 0·4, P < 0·01). It is concluded that the results of the present study agree with the hypothesis that the residual glycogen content of muscle has a direct effect on the technological yield of cooked ham processing.