Current Issues in Remote Sensing

In this article certain problems surrounding Satellite remote sensing (SRS) will be addressed with particular emphasis on their legal implications. Aspects of air law as they affect remote sensing will not be discussed in any detail, nor will it be necessary to refer to the vexing problem of determining the satisfactory boundary between the airspace and outer space. This fundamental problem is still in dispute and under constant review, both in scholarly circles and in the United Nations; and the world community may consider itself fortunate that the issue has not prevented a number of important international agreements on space law from being adopted. The status of SRS in the regimes created by these agreements will be the focus of this article

The protection of personal and medical data - a call for confidentiality

Personal data and privacy are increasingly being threatened by a boom in technological development - the replacement of conventional networks of communication with the perfected combination of computer and telecommunications. The subsequent high degree of transparency has the potential to damage the individual's right to 'informational self-determination'. The most common ways of unlawfully entering a computer data system, the reasons why an individual's information is treated as confidential and the ethical issues involved, international and local statutory instruments that protect such personal information, and ways to stop the outflow of personal information are discussed

Self-monitoring in het netwerk: een onderzoek naar de bruikbaarheid van de self-monitoring scale bij het verkrijgen van inzicht in sociale netwerken

in deze scriptie wordt veslag gedaan van een onderzoek naar de vraag welke bijdrage self-monitoring kan leveren aan het verkrijgen van inzicht in sociale netwerken. Daarbij worden diverse theorieën getoetst aan de praktijk

Cyanobacterial growth and cyanophycin production with urea and ammonium as nitrogen source

publishedVersio

Detection of noroviruses in foods: a study on virus extraction procedures in foods implicated in outbreaks of human gastroenteritis.

Disease outbreaks in which foods are epidemiologically implicated as the common source are frequently reported. Noroviruses and enteric hepatitis A viruses are among the most prevalent causative agents of foodborne diseases. However, the detection of these viruses in foods other than shellfish is often time-consuming and unsuccessful. In this study, three virus concentration methods were compared: polyethylene glycol (PEG) plus NaCl, ultracentrifugation, and ultrafiltration. Two RNA extraction methods, TRIzol and RNeasy Mini Kit (Qiagen), were compared for detection of viruses in whipped cream and lettuce (as representatives of the dairy and vegetable-fruit food groups, respectively). A seeding experiment with canine calicivirus was conducted to determine the efficiency of each virus extraction procedure. The PEG-NaCl-TRIzol method was most efficient for the detection of viruses in whipped cream and the ultracentrifugation-RNeasy-Mini Kit procedure was best for detection on lettuce. Based on the seeding experiments, food items implicated in norovirus-associated gastroenteritis outbreaks were subjected to the optimal procedure for a specific composition and matrix. No noroviruses were detected in the implicated food items, possibly because the concentration of virus on the food item was too low or because of the presence of inhibitory factors. For each food group, a specific procedure is optimal. Inhibitory factors should be controlled in these procedures because they influence virus detection in food

Toward microbial recycling and upcycling of plastics: prospects and challenges

Annually, 400 Mt of plastics are produced of which roughly 40% is discarded within a year. Current plastic waste management approaches focus on applying physical, thermal, and chemical treatments of plastic polymers. However, these methods have severe limitations leading to the loss of valuable materials and resources. Another major drawback is the rapid accumulation of plastics into the environment causing one of the biggest environmental threats of the twenty-first century. Therefore, to complement current plastic management approaches novel routes toward plastic degradation and upcycling need to be developed. Enzymatic degradation and conversion of plastics present a promising approach toward sustainable recycling of plastics and plastics building blocks. However, the quest for novel enzymes that efficiently operate in cost-effective, large-scale plastics degradation poses many challenges. To date, a wide range of experimental set-ups has been reported, in many cases lacking a detailed investigation of microbial species exhibiting plastics degrading properties as well as of their corresponding plastics degrading enzymes. The apparent lack of consistent approaches compromises the necessary discovery of a wide range of novel enzymes. In this review, we discuss prospects and possibilities for efficient enzymatic degradation, recycling, and upcycling of plastics, in correlation with their wide diversity and broad utilization. Current methods for the identification and optimization of plastics degrading enzymes are compared and discussed. We present a framework for a standardized workflow, allowing transparent discovery and optimization of novel enzymes for efficient and sustainable plastics degradation in the future.Microbial Biotechnolog

Hepatitis E virus RNA in commercially available porcine livers in The Netherlands

Hepatitis E virus (HEV) infections caused by genotype 3 are increasingly observed in industrialized countries, without a distinct source. High similarity between human and swine strains of HEV strongly suggest possible zoonotic transmission. It was reported previously that in 55% of Dutch pig farms HEV-excreting fattening pigs were present. In the current study, presence of HEV RNA in commercially available porcine livers was shown. We examined 62 commercially available porcine livers for HEV contamination. Before examination of livers, the most sensitive combination of tissue disruption and RNA-extraction was chosen from four disruption and seven RNA-extraction methods. Four of 62 livers were shown to be positive for HEV RNA by RT-PCR and Southern blot hybridization, and three sequences were obtained. Phylogenetic analysis showed clustering of the sequences with previously published Dutch HEV genotype 3 sequences from humans and swine. To study infectivity of possible virus, three pigs were intravenously inoculated with suspensions from commercially available HEV positive livers. Two other pigs served as high-dose or low-dose controls. The low-dose control received a comparable viral count as animals receiving inocula from commercially available livers, the high dose control received a viral count that was known to generate infection. Faecal shedding of HEV was observed in the high-dose control, indicating that the control virus was infectious. No faecal shedding of HEV was observed for the low-dose control and the three pigs that were administered the commercially available livers extracts. In conclusion, HEV RNA was found in commercially available porcine livers. inoculation of susceptible pigs with extracts from HEV-positive livers did not lead to infection, but this may be a dose-dependent effect. The risk for consumers should be investigated further

Development of a dynamic myocardial perfusion phantom model for tracer kinetic measurements

BACKGROUND: Absolute myocardial perfusion imaging (MPI) is beneficial in the diagnosis and prognosis of patients with suspected or known coronary artery disease. However, validation and standardization of perfusion estimates across centers is needed to ensure safe and adequate integration into the clinical workflow. Physical myocardial perfusion models can contribute to this clinical need as these can provide ground-truth validation of perfusion estimates in a simplified, though controlled setup. This work presents the design and realization of such a myocardial perfusion phantom and highlights initial performance testing of the overall phantom setup using dynamic single photon emission computed tomography. RESULTS: Due to anatomical and (patho-)physiological representation in the 3D printed myocardial perfusion phantom, we were able to acquire 22 dynamic MPI datasets in which 99mTc-labelled tracer kinetics was measured and analyzed using clinical MPI software. After phantom setup optimization, time activity curve analysis was executed for measurements with normal myocardial perfusion settings (1.5 mL/g/min) and with settings containing a regional or global perfusion deficit (0.8 mL/g/min). In these measurements, a specific amount of activated carbon was used to adsorb radiotracer in the simulated myocardial tissue. Such mimicking of myocardial tracer uptake and retention over time satisfactorily matched patient tracer kinetics. For normal perfusion levels, the absolute mean error between computed myocardial blood flow and ground-truth flow settings ranged between 0.1 and 0.4 mL/g/min. CONCLUSION: The presented myocardial perfusion phantom is a first step toward ground-truth validation of multimodal, absolute MPI applications in the clinical setting. Its dedicated and 3D printed design enables tracer kinetic measurement, including time activity curve and potentially compartmental myocardial blood flow analysis

Fast Data Sharing within a distributed multithreaded control framework for robot teams

In this paper a data sharing framework for multithreaded, distributed control programs is described that is realized in C++ by means of only a few, powerful classes and templates. Fast data exchange of entire data structures is supported using sockets as communication medium. Access methods are provided that preserve data consistency and synchronize the data exchange. The framework has been successfully used to build a distributed robot soccer control system running on as many computers as needed