A hundred-year retrospective on cryptosporidiosis

Tyzzer discovered the genus Cryptosporidium a century ago, and for almost 70 years cryptosporidiosis was regarded as an infrequent and insignificant infection that occurred in the intestines of vertebrates and caused little or no disease. Its association with gastrointestinal illness in humans and animals was recognized only in the early 1980s. Over the next 25 years, information was generated on the disease's epidemiology, biology, cultivation, taxonomy and development of molecular tools. Milestones include: (i) recognition in 1980 of cryptosporidiosis as an acute enteric disease; (ii) its emergence as a chronic opportunistic infection that complicates AIDS; (iii) acknowledgement of impact on the water industry once it was shown to be waterborne; and (iv) study of Cryptosporidium genomics.     

A task-based evaluation of PEM detector element size

Positron Emission Mammography (PEM) is a planar imaging method that utilizes arrays of discrete detector elements for the detection of radiotracer-avid breast cancer. In this investigation we have systematically studied, through computer simulations, the effect of detector element size (width and length) on breast lesion detection and localization tasks. The contrast-to-noise ratios of the spheres simulating breast lesions were calculated as a function of detector element dimension to gauge detectability. System resolution (fwhm) across the field-of-view was used as the metric for the localization task. For both tasks, individual detector elements of lyso with cross sectional dimensions of 2×2 mm (96×72 element arrays, step 2.1mm) and 3×3mm (65×49 element arrays, step 3.1 mm), and lengths of 10,15 and 20 mm were simulated. The results revealed that narrower pixel dimensions reduced the partial volume effect, while the thicker pixels increased pixel sensitivity, thus reducing noise per pixel and increasing the contrast-to-noise ratio.     

A project on nymphaeid-dominated systems

Summary In the present paper the general line of the research project on nymphaeid-dominated systems of the Laboratory of Aquatic Ecology (Catholic University, Nijmegen) is explained and a list of publications is given. In the nymphaeid system 16 structural elements could be distinguished which are spatially distributed over 15 compartments. As the nymphaeid system is very complex compared with other macrophyte-dominated systems, a team is working now on the project.The author is much indebted to other members of the nymphaeid team for their critical remarks.     

PEM Anchorage on Titanium Using Catechol Grafting

Background

This study deals with the anchorage of polyelectrolyte films onto titanium surfaces via a cathecol-based linker for biomedical applications.

Methodology

The following study uses a molecule functionalized with a catechol and a carboxylic acid: 3-(3,4-dihydroxyphenyl)propanoic acid. This molecule is anchored to the TiO₂ substrate via the catechol while the carboxylic acid reacts with polymers bearing amine groups. By providing a film anchorage of chemisorption type, it makes possible to deposit polyelectrolytes on the surface of titanium.

Principal Findings

Infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), contact angle and atomic force microscopy (AFM) measurements show that the different steps of grafting have been successfully performed.

Conclusions

This method based on catechol anchorage of polyelectrolytes open a window towards large possibilities of clinical applications.     

A personal retrospective on the second half of the 20th century

During the Second World War scientists and engineers were involved as never before in all technical phases of the war effort. It included intelligence, logistics and large scale automated computation. Much of this required team work which led to the adoption of interdisciplinary perspectives and found expression after the war in new fields of enquiry such as cybernetics, biophysics and artificial intelligence.     

A twenty year retrospective on the forest carbon dynamics in Russia

A regional forest carbon budget accounting technique based on carbon pools balance with incomes from growing woodstocks and losses from harvesting, fires and other disturbances have been developed. Forest carbon budgets of the Russian administrative units during 1988–2009 have been accounted. The carbon sink to Russian forests have increased from 80 Mt C × yr⁻¹ in 1988 to 230–240 Mt C × yr⁻¹ in late 2000s. This tendency is explained with the decline in harvesting, which have started in 1990s. European part of Russia was found to have higher areally averaged carbon sink compared with the Asian part. It have been associated with peculiar ways of wildfires governance in these two parts.     

A plan for the mouse genome project

The National Center for Human Genome Research and the Department of Energy convened a committee of geneticists and biologists who use the laboratory mouse in their research programs. Their responsibility was to identify goals and guidelines for completing the genetic and physical maps of the mouse genome. The motivation for convening this group was to make certain that existing and anticipated research projects together represent a comprehensive program for addressing the Five Year Goals of the Human Genome Project. Three meetings were held: the first addressed the contributions that the mouse can make to the Human Genome Project; the second meeting reviewed the status of the genetic map, gene mapping research, and genome informatics; and the final meeting evaluated the status of the physical map and physical mapping research. The committee then prepared a report that reviewed the status of the mouse genome project and made recommendations concerning areas of research emphasis. The resulting Request For Applications entitled Mapping the Mouse Genome with Emphasis on Technology Development (RFA: HG92-002) is an important mechanism for coordinating mouse genome research and accomplishing the goals of the mouse genome project. Progress towards complete genetic and physical maps has been impressive. The genetic map should be completed on schedule, and ongoing physical mapping projects are promising. Given rapid progress on these maps, the Working Group proposed expanding the focus of the mouse genome effort to begin planning comprehensive approaches for characterizing the function of the large number of genes that will soon be mapped and eventually sequenced. Partly as a consequence of the Working Group's efforts, discussions have begun among members of the scientific community and National Institutes of Health (NIH) staff to plan comprehensive, efficient, and innovative approaches for studying gene function. The Working Group prepared a report summarizing the status of mouse genome research and recommending areas where effort and funding should be placed. Our report was submitted to and accepted by the NIH and Department of Energy (DOE) and is published here in its entirety.Verne M. Champman, Chair, Neal G. Copeland, Franklin D. Costantini, William F. Dove, Joseph H. Nadeau, Roger H. Reeves, Janet Rossant, Oliver Smithies, and Richard P. Woychik.     

A mouse phenome project

A community-wide effort to establish baseline phenotypic data on commonly used and genetically diverse inbred mouse strains and to provide the information through a publicly accessible database. Received: 21 April 2000 / Accepted: 25 April 2000     

A fruitful outcome to the papaya genome project

The draft genome sequence of a transgenic virus-resistant papaya marks the first genome sequence of a commercially important transgenic crop plant.     

A retrospective look at the cationic peanut peroxidase structure

The cationic peanut peroxidase has been studied in detail, not only with regard to its peptide structure, but also to the sites and role of the three moieties linked to it. Peanut peroxidase lends itself well to a close examination as a potential example for other plant peroxidase studies. It was the first plant peroxidase for which a 3-D structure was derived from crystals, with the glycans intact. Subsequent analysis of peroxidases structures from other plants have not shown great differences to that of the peanut peroxidase. As the period of proteomics follows on the era of genomics, the study of glycans has been brought back into focus. With the potential use of peroxidase as a polymerization agent for industry, there are some aspects of the overall structure that should be kept in mind for successful use of this enzyme. A variety of techniques are now available to assay for these structures/moieties and their roles. Peanut peroxidase data are reviewed in that light, as well as defining some true terms for isozymes. Because a high return of the enzyme in a pure form has been obtained from cultured cells in suspension culture, a brief review of this is also offered.     

A retrospective study on the preserving capacity of a commercial boar semen extender

The objective of this study was to evaluate the preserving capacity of a commercial, long-term boar semen extender beyond 4 days in terms of farrowing failure and total born per litter in sows and gilts. Data from 21 farms were subjected to logistic and linear regression analyses to assess the effect of parity (2-5, > 5 and gilts), wean-to-service interval (/= 6 days) and number of AI (1, 2, or 3) on the association between semen age (/=10 days) and fertility. As the semen age increased, the likelihood of farrowing failure increased and total born per litter decreased in sows and gilts. The effect of semen ageing on farrowing failure was more pronounced in sows than in gilts as in the latter it became significant only after 8 days. The effect of semen ageing on total born per litter was similar in both sows and gilts. A lower parity and wean-to-service interval were associated with a reduction in farrowing failure and increase in total born per litter in sows. Increasing the number of inseminations up to two was beneficial in reducing farrowing failure in sows and gilts. A third insemination increased the likelihood of farrowing failure in sows. The number of total born per litter in sows increased with number of inseminations and the effect was not significant in gilts.     

Tailoring the Membrane‐Electrode Interface in PEM Fuel Cells: A Review and Perspective on Novel Engineering Approaches

The interface between the catalyst layer (CL) and the polymer electrolyte membrane (PEM) in a fuel cell has substantial impact on its electrochemical performance. In consequence, there have been growing research activities to engineer this interface to improve the performance of polymer electrolyte membrane fuel cells (PEMFCs). This review summarizes these novel approaches and compares the various techniques. Based on available fuel cell data in the literature, a quantitative comparison of relative improvements due to a micro‐ and nano‐engineered PEM|CL interface is provided. This allows several conclusions: First, regardless of the applied method, a re‐engineering of the PEM|CL interface leads to an improvement of power‐determining parameters, such as mass transport resistances. The latter has hitherto not been clearly connected to the PEM|CL interface and is an important piece of information for future fuel cell development. Second, for patterned membrane surfaces, feature sizes of about 1–10 µm on the membrane surface seem to result in the most significant power density improvement. Third, an engineered PEMCL interface can contribute to extend the fuel cell durability due to enhanced adhesion and contact between the two layers. With this, novel membrane electrode assemblies (MEAs) can be designed that enable significantly higher power densities compared conventional 2D‐layer MEAs.     

A case study on the detailed reproducibility of a Human Cell Atlas project

Background: Reproducibility is a defining feature of a scientific discovery. Reproducibility can be at different levels for different types of study. The purpose of the Human Cell Atlas (HCA) project is to build maps of molecular signatures of all human cell types and states to serve as references for future discoveries. Constructing such a complex reference atlas must involve the assembly and aggregation of data from multiple labs, probably generated with different technologies. It has much higher requirements on reproducibility than individual research projects. To add another layer of complexity, the bioinformatics procedures involved for single-cell data have high flexibility and diversity. There are many factors in the processing and analysis of single-cell RNA-seq data that can shape the final results in different ways. Methods: To study what levels of reproducibility can be reached in current practices, we conducted a detailed reproduction study for a well-documented recent publication on the atlas of human blood dendritic cells as an example to break down the bioinformatics steps and factors that are crucial for the reproducibility at different levels. Results: We found that the major scientific discovery can be well reproduced after some efforts, but there are also some differences in some details that may cause uncertainty in the future reference. This study provides a detailed case observation on the on-going discussions of the type of standards the HCA community should take when releasing data and publications to guarantee the reproducibility and reliability of the future atlas. Conclusion: Current practices of releasing data and publications may not be adequate to guarantee the reproducibility of HCA. We propose building more stringent guidelines and standards on the information that needs to be provided along with publications for projects that evolved in the HCA program.     

Neuroma under the fifth metatarsal head. A retrospective study

This retrospective study was carried out over 83 surgical cases at the distal portion of the fifth metatarsal, compromising the treatment of tailor's bunion, fifth metatarsal overload and the concomitant presence of both pathologies in some cases. Neuromas were founded under the fifth metatarsal head in 18 of the cases studied (21.7%). The results look at whether if there is an association between different fifth metatarsal pathologies and the presence of neuromas and found a significant association between the appearance of neuromas in patients with the same metatarsal overload, especially if it is accompanied by a tailor's bunion pathology.