Constraint Handling Guided by Landscape Analysis in Combinatorial and Continuous Search Spaces.

The notion and characterisation of fitness landscapes has helped us understand the performance of heuristic algorithms on complex optimisation problems. Many practical problems, however, are constrained, and when significant areas of the search space are infeasible, researchers have intuitively resorted to a variety of constraint-handling techniques intended to help the algorithm manoeuvre through infeasible areas and toward feasible regions of better fitness. It is clear that providing constraint-related feedback to the algorithm to influence its choice of solutions overlays the violation landscape with the fitness landscape in unpredictable ways whose effects on the algorithm cannot be directly measured. In this work, we apply metrics of violation landscapes to continuous and combinatorial problems to characterise them. We relate this information to the relative performance of six well-known constraint-handling techniques to demonstrate how some properties of constrained landscapes favour particular constraint-handling approaches. For the problems with sampled feasible solutions, a bi-objective approach was the best performing approach overall, but other techniques performed better on problems with the most disjoint feasible areas. For the problems with no measurable feasibility, a feasibility ranking approach was the best performing approach overall, but other techniques performed better when the correlation between fitness values and the level of constraint violation was high.

The sources and dynamics of fine-grained sediment degrading the Freshwater Pearl Mussel (Margaritifera margaritifera) beds of the River Torridge, Devon, UK.

The Freshwater Pearl Mussel (Margaritifera margaritifera) is an endangered organism across its entire range. It has a complex life cycle and stringent habitat requirements and is therefore an indicator species for the general ecosystem health of host rivers. Whereas historical intensive pearl fishing contributed to population declines, excess nutrient and sediment loss associated with current land use pressures in host river catchments, including modern intensive farming practices, are now highlighted as primary contributory factors. Accordingly, this study investigated the sources and dynamics of fine-grained sediment sampled in the mussel beds of the River Torridge, SW England. Sediment source fingerprinting using a combination of colorimetric and radiometric tracers to construct different composite signatures revealed the importance of roads both as a sediment source and delivery pathway for fine-grained sediment mobilised from fields predominantly supporting lowland livestock farming. Grassland fields with evidence of soil poaching were highlighted as important sediment sources, but equally, riparian woodland was also identified as important, especially during the latter stages of consecutive runoff events when its rainfall buffering capacity was exceeded. Bed sediment storage levels (median up to 393 g m-2) were found to be low (41st percentile) compared to typical values reported by a recent strategic scale survey across England and Wales, whereas elevated turbidity peaks were shown to be long duration (days) in conjunction with consecutive days of rainfall and corresponding runoff events. Hysteresis patterns varied but were generally clockwise during the largest runoff events associated with consecutive rain days; again, suggesting mobilisation of sediment from proximal woodland sources following exceedance of rainfall buffering capacity. In combination, the data assembled by this study provides a basis for planning sediment control measures for protecting the Freshwater Pearl Mussel (FPM) beds from excessive fine-grained sediment inputs associated with the intensive use of primarily grazing land.

Bronchoalveolar lavage for diagnosis of tuberculosis infection in elephants.

Tuberculosis (TB) has been known to affect elephants for thousands of years. It was put into spotlight when few circus elephants were diagnosed carrying Mycobacterium (M.) tuberculosis. Because of the zoonotic risk and high susceptibility to M. tuberculosis, periodic testing was enacted since, in captive breeding programmes. Presently, trunk wash is the recommended diagnostic procedure for TB. Trunk wash, however, puts the operator at risk, has low sensitivity, and is prone to contamination. Here, bronchoalveolar lavage is described for the first time for TB diagnosis in elephants. Bronchial, trunk and mouth fluids were investigated using bacterial culture, M. tuberculosis complex (MTC)-specific real-time quantitative PCR (qPCR) and mycobacterial genus-specific qPCR for overall presence of mycobacteria or mycobacterial DNA including bacteria or DNA of closely related genera, respectively, in 14 elephants. Neither bacteria of the MTC nor their DNA were identified in any of the elephants. Yet, 25% of the cultures grew non-tuberculous mycobacteria (NTM) or closely related bacterial species. Furthermore, 85% of the samples contained DNA of NTM or closely related bacterial genera. This finding might explain continued false-positive results from various serological tests. From a zoonotic point of view, bronchoalveolar lavage is safer for the testing personal, has higher probability of capturing MTC and, through PCR, identifies DNA NTM in elephants. Yet, necessary endoscopic equipment, animal sedation and access to a TB reference laboratory might pose challenging requirements in remote conditions in some elephant range countries.

Identifying Features of Fitness Landscapes and Relating Them to Problem Difficulty.

Complex combinatorial problems are most often optimised with heuristic solvers, which usually deliver acceptable results without any indication of the quality obtained. Recently, predictive diagnostic optimisation was proposed as a means of characterising the fitness landscape while optimising a combinatorial problem. The scalars produced by predictive diagnostic optimisation appear to describe the difficulty of the problem with relative reliability. In this study, we record more scalars that may be helpful in determining problem difficulty during the optimisation process and analyse these in combination with other well-known landscape descriptors by using exploratory factor analysis on four landscapes that arise from different search operators, applied to a varied set of quadratic assignment problem instances. Factors are designed to capture properties by combining the collinear variances of several variables. The extracted factors can be interpreted as the features of landscapes detected by the variables, but disappoint in their weak correlations with the result quality achieved by the optimiser, which we regard as the most reliable indicator of difficulty available. It appears that only the prediction error of predictive diagnostic optimisation has a strong correlation with the quality of the results produced, followed by a medium correlation of the fitness distance correlation of the local optima.

Nationwide Cross-Sectional Study on Bovine Tuberculosis by Intra Vitam Testing in Germany, 2013-2014.

Germany was declared officially free from bovine tuberculosis (bTB) effective from 1 July 1996. After the occurrence of several Mycobacterium (M.) bovis outbreaks in north-western Germany in recent years with high intraherd prevalence at the time of detection, the reliability of abattoir surveillance as the principal component of the national bTB control programme was debated by veterinary public health officials. Rising numbers of wildlife-associated outbreaks caused by M. caprae in southern Germany eventually prompted a nationwide cross-sectional study on bTB. A total of 51 999 cattle, that is 0.41% of the national herd kept on 1.73% of German cattle farms, were tested. Despite 4 positive and 152 inconclusive single intradermal comparative cervical test results, none of the animals was confirmed as bTB-positive by a subsequent interferon-release assay or by post-mortem PCR testing. The estimated prevalence of bTB in Germany was thus calculated as 0.0% (CI 0.0000-0.0064%) affirming that Germany still qualifies as an officially tuberculosis-free (OTF) country. Occasional randomized nationwide testing can be an appropriate tool to reassure the OTF status and may also help to maintain an appropriate training level for the diagnostic procedures and for supporting sustained disease awareness among stakeholders.

Mycobacterium tuberculosis exposure of livestock in a German dairy farm: implications for intra vitam diagnosis of bovine tuberculosis in an officially tuberculosis-free country.

Germany has been an officially bovine tuberculosis (bTB)-free (OTF) country since 1996. Gradually rising numbers of bTB herd incidents due to Mycobacterium bovis and M. caprae in North-Western and Southern Germany during the last few years prompted the competent authorities to conduct a nationwide bTB survey in 2013/2014. This led to the detection of a dairy herd in which as many as 55 cattle reacted positively to consecutive intra vitam testing. Test-positive animals lacked visible lesions indicative of bTB at necropsy. Extensive mycobacterial culturing as well as molecular testing of samples from 11 tissues for members of the M. tuberculosis complex (MTC) yielded negative results throughout. However, caseous lymphadenitis of Ln. mandibularis accessorius was observed during meat inspection of a fattening pig from the same farm at regular slaughter at that time. Respective tissue samples tested MTC positive by polymerase chain reaction, and M. tuberculosis T1 family were identified by spoligotyping. Four human reactors within the farmer's family were also found to be immunoreactive. As exposure of livestock to M. tuberculosis is not generally considered, its impact may result in regulatory and practical difficulties when using protocols designed to detect classical bTB, particularly in OTF countries.

Bovine Tuberculosis and Brucellosis in Cattle and African Buffalo in the Limpopo National Park, Mozambique.

Bovine tuberculosis (BTB) and brucellosis are prevalent in buffaloes of the Kruger National Park (KNP, South Africa). Both diseases were considered to have no or a very low prevalence in wildlife and livestock in and around the Limpopo National Park (LNP, Mozambique). The same applies for tuberculosis in Gonarezhou National Park (GNP, Zimbabwe), but just recently, BTB was detected in buffaloes in the GNP and fears arose that the disease might also spread to the LNP as a result of the partial removal of the fences between the three parks to form the Great Limpopo Transfrontier Park. To assess the status of both diseases in and around LNP, 62 buffaloes were tested for bovine tuberculosis (BTB) and bovine brucellosis. The percentage of positive BTB reactors in buffalo was 8.06% using BovidTB Stat-Pak® and 0% with BOVIGAM® IFN-γ test and IDEXX ELISA. The brucellosis seroprevalence in buffalo was found to be 17.72% and 27.42% using Rose Bengal Test (RBT) and ELISA, respectively. In addition, 2445 cattle in and around the LNP were examined for BTB using the single intradermal cervical comparative tuberculin test (SICCT), and an apparent prevalence of 0.98% was found with no significant difference inside (0.5%) and outside (1.3%) the park. This is the first published report on the presence of positive reactors to BTB and bovine brucellosis in buffalo and cattle in and outside the LNP. Monitoring the wildlife-livestock-human interface of zoonotic high-impact diseases such as BTB and brucellosis is of outmost importance for the successful implementation and management of any transfrontier park that aims to improve the livelihoods of the local communities.

[Tuberculosis in cattle - surprisingly re-emerging or continuously present?]. / Die Tuberkulose des Rindes - überraschend wieder oder immer noch präsent?

Tuberculosis in cattle, caused by Mycobacterium (M.) bovis/M. caprae, is globally one of the most important zoonotic diseases in cattle. It was widespread in Germany until the second half of the 20th century. Due to the effective control and eradication campaigns in Germany, the epidemic was almost eradicated. Consequently, Germany was regarded as essentially tuberculosis free since the end of 1961 (West) and the end of 1978 (East). By declaring the unified Germany "officially free of tuberculosis" (OTF) in 1996, freedom from tuberculosis was officially ratified by the European Commission. The prerequisite was the detection of tuberculosis in less than 0.1% of the cattle holdings per year in Germany. This status has been steadily maintained hitherto, thus resulting in some loss of awareness of bovine tuberculosis by veterinarians, farmers and the public over many decades. After 1996, the number of notified outbreaks had been on average less than 10 per 200,000 cattle holdings per year for many years. It was the year 2008 when the numbers increased. Based in part on subsequently enhanced ante mortem testing efforts, 46 outbreaks were notified in 2013. Bavaria and Lower Saxony were the federal states with the highest number of cases. Consequently, the national tuberculosis regulation was revised in 2009, 2012 and 2013 to form the basis for a modification of tuberculosis surveillance. Regionally, an improvement of the control strategy was considered necessary. In addition to the traditionally applied examination and detection methods of the tuberculin skin test (ante mortem) and bacteriological culture (post mortem), the gamma-interferon-release assay (ante mortem) and the molecular detection of the causative pathogen (post mortem) were introduced into the official collection of recommended methods. Consequently, the diagnostic procedure of tuberculosis has been accelerated. However, in many cases the increase in the range of available test systems did not increase the ease in the interpretation of results.

An unusual case of spinal cord restricted mycobacteriosis in a European mink.

Granulomatous myelitis due to infection with Mycobacterium avium was diagnosed in a 4-year-old male neutered European mink (Mustela lutreola). The causative agent was detected by an acid-fast stain and further characterized by polymerase chain reaction and DNA sequencing of the PCR product. A thorough histological evaluation of the remaining organs revealed no granulomatous lesions or detectable acid-fast organisms. Although minks are generally highly susceptible for mycobacteria, localised infections, especially of the central nervous system, are unusual and may represent an atypical chronic form of the disease.

[Tuberculosis infection control - recommendations of the DZK]. / Infektionsprävention bei Tuberkulose - Empfehlungen des DZK.

The epidemiological situation of tuberculosis (TB) in Germany has improved considerably during the past few years. However, those in unprotected contact with infectious tuberculosis patients frequently and/or over longer periods of time and/or intensively continue to have a higher risk for TB infection. Rapid diagnosis, prompt initiation of effective treatment, and adequate infection control measures are of particular importance to prevent infection. The present recommendations depict the essentials of infection control as well as specific measures in the hospital (isolation, criteria for its duration and technical requirements, types of respiratory protection, disinfection measures, waste disposal). The specific requirements for outpatients (medical practice), at home, for ambulance services, and in congregate settings, including prisons, are also addressed. Compared with the previous recommendations the pattern of respiratory protection measures has been simplified. As a rule, hospital staff and those visiting infectious tuberculosis patients are advised to wear respiratory protection that satisfies the criteria of FFP2-masks (DIN EN 149), while patients should wear mouth-nose protectors (surgical masks) in the presence of others and outside the isolation room. A detailed depiction of criteria for isolation and its duration in smear positive and only culturally confirmed pulmonary tuberculosis has been added.

Outbreak of reproductive disorders and mycobacteriosis in swine associated with a single strain of Mycobacterium avium subspecies hominissuis.

In a breeding and fattening pig farm an increasing number of cases of abortion and generalized mycobacteriosis at slaughter occurred. Pathological findings compatible with mycobacteriosis, acid-fast organisms in tissues, and isolation of mycobacteria from tissue samples including fetuses, lungs and reproductive organs from sows, genital swabs, mesenteric lymph nodes, and from a sperm sample revealed the cause of the disease. Bacterial cultures were identified as Mycobacterium avium subsp. hominissuis using IS901-/IS1245-specific PCR. Genotyping of selected isolates from animals as well as from their environment by MIRU-VNTR analysis showed that the herd was infected with one single outbreak strain. The same genotype was also isolated from pigs of two other farms which showed comparable symptoms and were in direct contact with the index farm as well as from their environment. Immunological host responses detected by tuberculin skin test and ELISA gave positive results at herd level only. Despite the detection of other potential pathogens mycobacteria were regarded as the causative agent of the reproductive disorders. To our knowledge this is the first report of an epidemic mycobacterial infection in a pig holding associated with reproductive disorders, which could be attributed to one single virulent strain, and the first report of detection of M. avium subsp. hominissuis in pig sperm.

[Tuberculosis infection control--recommendations of the DZK]. / Infektionsprävention bei Tuberkulose--Empfehlungen des DZK.

The epidemiological situation of tuberculosis (TB) in Germany has improved considerably during the past few years. However, those in unprotected contact with infectious tuberculosis patients frequently and/or over longer periods of time and/or intensively continue to have a higher risk for TB infection. Rapid diagnosis, prompt initiation of effective treatment, and adequate infection control measures are of particular importance to prevent infection. The present recommendations depict the essentials of infection control as well as specific measures in the hospital (isolation, criteria for its duration and technical requirements, types of respiratory protection, disinfection measures, waste disposal). The specific requirements for outpatients (medical practice), at home, for ambulance services, and in congregate settings, including prisons, are also addressed. Compared with the previous recommendations the pattern of respiratory protection measures has been simplified. As a rule, hospital staff and those visiting infectious tuberculosis patients are advised to wear respiratory protection that satisfies the criteria of FFP2-masks (DIN EN 149), while patients should wear mouth-nose protectors (surgical masks) in the presence of others and outside the isolation room. A detailed depiction of criteria for isolation and its duration in smear positive and only culturally confirmed pulmonary tuberculosis has been added.

Bovine tuberculosis: making a case for effective surveillance.

In 2008, a cow with marked gross lesions suspicious for bovine tuberculosis (bTB) was identified by meat inspection at home slaughtering in north-western Germany. Epidemiological investigations led to the identification of another 11 affected farms with a total of 135 animals which reacted positive to the skin test. Eight affected farms had been in trade contact with the putative index farm. While the source for the initial introduction remained unknown, it was shown that all isolates tested shared the same molecular characteristics suggesting a common source of infection. The findings demonstrate that bTB can easily be transmitted via animal trade and may remain undetected for years in herds in the absence of tuberculin testing. Hence, we believe that bTB surveillance should not rely only on meat inspection, but on a combination of both meat inspection and intradermal tuberculin testing.

Mycobacterium pinnipedii: transmission from South American sea lion (Otaria byronia) to Bactrian camel (Camelus bactrianus bactrianus) and Malayan tapirs (Tapirus indicus).

Tuberculosis infections caused by Mycobacterium (M.) pinnipedii in a South American sea lion, Bactrian camel, and Malayan tapirs kept in two zoological gardens spanning a time period of 5 years are reported. The zoos were linked by the transfer of one tapir. Conventional bacteriological and molecular methods were applied to detect the pathogen. Spoligotyping and MIRU/VNTR-typing performed to assess the genetic similarity revealed identical molecular characteristics of the isolates from all animals involved. Anti-tuberculosis antibodies were detected using ELISA and a recently developed serological rapid test. The study shows that: (i) using molecular methods, the assessment of the genetic relationship of infectious agents helps to confirm the routes of infection, and that (ii) immunological tests may help to detect tuberculosis infections ante mortem more reliably and early. This would prevent the transfer of tuberculosis by asymptomatic animals.

Multiple granulomas in three squirrel monkeys (Saimiri sciureus) caused by Mycobacterium microti.

Mycobacterium microti, a member of the Mycobacterium tuberculosis complex, causes tuberculosis in small rodents and occasionally in other mammals including man. Three adult male squirrel monkeys, two with a history of lethargy, weakness and stridor and one with paralysis of the hind legs, were presented for necropsy. One of the two lethargic animals showed multiple granulomas in the mesentery, mesenteric lymph nodes, lung, liver, kidneys and spleen, while the other showed granulomas only in the lung. The animal with paralysis of the legs had an abscess-like lesion in the skeletal muscle of the neck, granulomas in the mesenteric and mediastinal lymph nodes, and a fracture of the thirteenth thoracic vertebra with severe lesions of the spinal cord. Histologically the granulomas showed typical features of tuberculous granulomas, i.e., central necrosis surrounded by epithelioid cells, multinucleated giant cells, inflammatory cells and a border of connective tissue. Ziehl-Neelsen stain demonstrated sporadic acid-fast bacilli within the granulomas, these organisms being identified as M. microti by microbiological and molecular methods.

Outbreak of Mycobacterium bovis infection in a wild animal park.

An outbreak of tuberculosis due to Mycobacterium bovis occurred in a wild animal park. Three pot-bellied pigs (Sus scrofa vittatus), one red deer (Cervus elaphus), one buffalo (Bison bonasus) and two European lynxes (Lynx lynx) were affected and showed clinical signs including weight loss, enlarged lymph nodes and paralysis of the hindlimbs. Postmortem examinations revealed multifocal granulomatous lesions in various organs, including the lymph nodes, lungs, intestines, kidneys and the central nervous system. Acid-fast organisms were demonstrated in various organs histologically and bacteriologically. Spoligotyping of 17 isolates from various organs of the affected animals confirmed an infection by M bovis and revealed an identical pattern indicating a common origin. The spoligotype was different from the pattern of M bovis recorded in the cattle population in Germany between 2000 and 2006. Investigations of sentinel animals such as an aged silver fox (Vulpes vulpes), a badger (Meles meles), a ferret (Mustela putorius) and rodents, and tuberculin skin tests of the animal attendants and randomly collected faecal samples from the enclosures were all negative for M bovis.

[Intermittent compression devices for swelling reduction and thrombosis prophylaxis--a pilot study after total hip replacement. Is the 2 hour daily minimum application sufficient?]. / Die intermittierende Impulskompression zur Abschwellung und Thromboseprophylaxe--Pilotstudie nach Hüft-TEP. Ist die Minimalanwendungsdauer von 2 h täglich ausreichend?

BACKGROUND: The use of intermittent compression devices for thrombosis prophylaxis and the reduction of postoperative swelling are widely accepted. The recommended minimum application of 2 h daily has never been statistically verified. Without evidence based data, the benefit of this costly equipment cannot be maximized. PATIENTS AND METHODS: A randomized clinical trial on 41 patients after total hip replacement was performed. The A-V Impulse System was applied for 2 h a day during the first 5 postoperative days to observe whether this time was sufficiently effective. RESULTS: In the control group, two deep vein thromboses occurred postoperatively, but there were none in the treatment group. Even though two patients from the treatment group had to be excluded from the study because of severe pain, all other parameters including visual analogue pain scale results and limb circumferences were comparable in both groups. CONCLUSION: These preliminary results suggest that pump systems can prevent deep venous thrombosis after hip surgery even when applied for only short intervals over a short period of time. However, large scale confirmatory studies are needed.

Comparative macrorestriction and RFLP analysis of Mycobacterium avium subsp. avium and Mycobacterium avium subsp. hominissuis isolates from man, pig, and cattle.

In Germany, tuberculous lesions in slaughtered pigs due to infection with members of the Mycobacterium avium complex are increasingly reported. Contaminated food originating from pig or other livestock is discussed as potential source of human infection. M. avium isolates from man (n=45), pig (n=29), and cattle (n=13) were characterised by restriction fragment length polymorphism (RFLP) with respect to insertion sequences IS1245 and IS901 as well as by XbaI-based pulsed-field gel electrophoresis (PFGE) and the results were compared by computer cluster correlation analysis, to determine potential sources of infection in man. By PCR, 55% of animal isolates was identified as M. avium subsp. avium, and 45% as M. a. hominissuis. All human isolates belonged to M. a. hominissuis. IS1245-RFLP and PFGE resulted in two distinct main groupings reflecting the two subspecies, and dividing the isolates into several subgroups. Animal isolates of M. a. hominissuis were widely distributed within the subgroups of human isolates. M. a. avium isolates, further discriminated by IS901-RFLP, formed host-associated subgroups for animals. Comparison of RFLP patterns with those of PFGE resulted in different subgroups as well as different pairs of isolates with high similarities. Only two isolates exhibited identical patterns by both methods. In general, results of both methods support the possibility that M. a. hominissuis isolates from livestock represent a source of infection for man, probably by common environmental reservoirs. There was no evidence of human infections caused by M. a. avium in Germany.

Sensitivity enhancement for colorimetric glucose assays on whole blood by on-chip beam-guidance.

In this paper, we present a novel concept for optical beam-guidance to significantly enhance the sensitivity of colorimetric assays by extending the optical path length through the detection cell which linearly impacts the resulting attenuation of a probe beam according to the law of Beer-Lambert. In our setup, the incident probe beam is deflected by 90( composite function) into the chip plane at monolithically integrated V-grooves to pass a flat detection cell at its full width (i.e., with a path length of 10 mm) instead of its usually much smaller height. Afterwards, the attenuated beam is redirected by another V-groove towards an external detector. The general beam-guidance concept is demonstrated by a glucose assay on human whole blood on a centrifugal microfluidic "lab-on-a-disk" platform made of COC. We achieve an excellent linearity with a correlation coefficient (R (2)) of 0.997 paired with a lower limit of detection (200 microM) and a good reproducibility with a coefficient of variation (CV) of 4.0% over nearly three orders of magnitude. With an accelerated sedimentation of cellular constituents by centrifugal forces, the sample of whole blood can be analyzed in a fully integrated fashion within 210 s. This time-to-result can even be improved by the numerical extrapolation of the saturation value. Additionally, the direct assay on whole blood also shows a negligible correlation with the hematocrit of the blood sample.

High-resolution genotyping of Campylobacter upsaliensis strains originating from three continents.

Ninety-six Campylobacter upsaliensis strains that originated from Australia, Canada, and Europe (Germany) and that were isolated from humans, dogs, and cats were serotyped for their heat-stable surface antigens. All of them were genotyped by enterobacterial repetitive intergenic consensus sequence PCR (ERIC-PCR) profiling, and 83 strains were genotyped by macrorestriction analysis with the endonuclease XhoI. Eighty-four percent of the strains belonged to five different serotypes (serotypes OI, OII, OIII, OIV, and OVI), with the proportions of strains in each serotype being comparable among the groups of strains from all three continents. Two serotypes, OIII and OIV, were prevalent at rates of 35 to 40%. Serotypes OI, OII, and OVI were detected at rates of 1.5 to 15%. Between 10 and 17.7% of the strains did not react with the available antisera. Analysis of the ERIC-PCR profiles revealed two distinct genotypic clusters, which represented the German and the non-European strains, respectively. XhoI macrorestriction yielded two genotypic clusters; one of them contained 80.2% of the German strains and 34.6% of the non-European strains, and the second cluster consisted of 65.4% of the non-European strains and 19.8% of the German strains. Fourteen strains from all three continents were analyzed for their 16S rRNA gene sequences. Only two minor variations were detected in four of the strains. In conclusion, C. upsaliensis has undergone diverging processes of genome arrangement on different continents during evolution without segregating into different subspecies.