Establishing a community-wide DNA barcode library as a new tool for arctic research.

DNA sequences offer powerful tools for describing the members and interactions of natural communities. In this study, we establish the to-date most comprehensive library of DNA barcodes for a terrestrial site, including all known macroscopic animals and vascular plants of an intensively studied area of the High Arctic, the Zackenberg Valley in Northeast Greenland. To demonstrate its utility, we apply the library to identify nearly 20 000 arthropod individuals from two Malaise traps, each operated for two summers. Drawing on this material, we estimate the coverage of previous morphology-based species inventories, derive a snapshot of faunal turnover in space and time and describe the abundance and phenology of species in the rapidly changing arctic environment. Overall, 403 terrestrial animal and 160 vascular plant species were recorded by morphology-based techniques. DNA barcodes (CO1) offered high resolution in discriminating among the local animal taxa, with 92% of morphologically distinguishable taxa assigned to unique Barcode Index Numbers (BINs) and 93% to monophyletic clusters. For vascular plants, resolution was lower, with 54% of species forming monophyletic clusters based on barcode regions rbcLa and ITS2. Malaise catches revealed 122 BINs not detected by previous sampling and DNA barcoding. The insect community was dominated by a few highly abundant taxa. Even closely related taxa differed in phenology, emphasizing the need for species-level resolution when describing ongoing shifts in arctic communities and ecosystems. The DNA barcode library now established for Zackenberg offers new scope for such explorations, and for the detailed dissection of interspecific interactions throughout the community.

Community analysis of biting midges (Culicoides Latr.) on livestock farms in Denmark.

This study presents descriptive statistics and community analysis of adult biting midges trapped at 16 livestock farms by means of light traps on Zealand and Lolland-Falster, Denmark. A total of 9,047 male and female Culicoides divided into 24 species, were caught. Biotic and abiotic factors ranging from presence of different host species (cattle or sheep/goats), presence of small woody areas or wetlands in the surrounding landscape, and agricultural practice (organic or conventional) were included in the community analysis. Only differences in the Culicoides communities between conventional and organic practices were tested significantly different. Total numbers of Culicoides individuals were higher on the organic farms than on the conventional farms. The larger loads of biting midges on the organic farms may be due to free-ranging animals that attracted the midges on pastures and carried them to the stable environment (the cattle of the conventional farms were held inside the stables). Presence of deciduous trees within 500 m of the farms resulted in higher numbers of Culicoides obsoletus s.s., while presence of wetlands increased the numbers of Culicoides punctatus and Culicoides pulicaris. Furthermore, Culicoides riethi and Culicoides puncticollis (subgenus Monoculicoides) were recorded in high numbers on individual farms. C. puncticollis was found for the first time in Denmark and so far only recorded from Zealand.

Phenotypic differentiation and phylogenetic signal of wing shape in western European biting midges, Culicoides spp., of the subgenus Avaritia.

In the past decade biting midges of the subgenus Avaritia (Diptera: Ceratopogonidae) have been popular subjects of applied entomological studies in Europe owing to their implication as biological vectors in outbreaks of bluetongue and Schmallenberg viruses. This study uses a combination of cytochrome oxidase subunit I barcode sequencing and geometric morphometric analyses to investigate wing shape as a means to infer species identification within this subgenus. In addition the congruence of morphological data with different phylogenetic hypotheses is tested. Five different species of the subgenus Avaritia were considered in the study (C. obsoletus (Meigen); C. scoticus Kettle and Lawson; C. chiopterus (Meigen); C. dewulfi Goetghebuer and C. imicola (Kieffer)). The study demonstrated that over 90% of individuals could be separated correctly into species by their wing shape and that patterns of morphological differentiation derived from the geometric morphometric analyses were congruent with phylogenies generated from sequencing data. Morphological data produced are congruent with monophyly of the subgenus Avaritia and the exclusion of C. dewulfi from the group containing C. obsoletus, C. scoticus and C. chiopterus. The implications of these results and their importance in a wider context of integrating multiple data types to interpret both phylogeny and species characterization is discussed.

A multi-domain Chebyshev collocation method for predicting ultrasonic field parameters in complex material geometries.

The use of ultrasound to measure elastic field parameters as well as to detect cracks in solid materials has received much attention, and new important applications have been developed recently, e.g., the use of laser generated ultrasound in non-destructive evaluation (NDE). To model such applications requires a realistic calculation of field parameters in complex geometries with discontinuous, layered materials. In this paper we present an approach for solving the elastic wave equation in complex geometries with discontinuous layered materials. The approach is based on a pseudospectral elastodynamic formulation, giving a direct solution of the time-domain elastodynamic equations. A typical calculation is performed by decomposing the global computational domain into a number of subdomains. Every subdomain is then mapped on a unit square using transfinite blending functions and spatial derivatives are calculated efficiently by a Chebyshev collocation scheme. This enables that the elastodynamic equations can be solved within spectral accuracy, and furthermore, complex interfaces can be approximated smoothly, hence avoiding staircasing. A global solution is constructed from the local solutions by means of characteristic variables. Finally, the global solution is advanced in time using a fourth order Runge-Kutta scheme. Examples of field prediction in discontinuous solids with complex geometries are given and related to ultrasonic NDE.

Effects on Detoxification Enzymes in Different Life Stages of Honey Bees (Apis mellifera L., Hymenoptera: Apidae) Treated with a Synthetic Pyrethroid (Flumethrin).

The activities of two detoxification enzymes, glutathione S-transferase (GST) with 1-chloro-2,4-dinitrobenzene (CDNB) as substrate, and glutathione peroxidase with tertbutyl hydroperoxide as substrate (GSH-Px[TBH]), were measured in the larvae, pupae and adults of honey bees (Apis mellifera ligustica Spinola) originating from two colonies, one untreated acting as a control group and the other treated with flumethrin. The treatment with flumethrin led to increased GST activity in the larval instars, pupae and nurse bees compared with the control group. In particular, the late fifth larval instars (LS) and the pupal instars showed increased GST activities. GSH-Px[TBH] activities were highest in the early larval instars (L1-L2). Treatment with flumethrin resulted in the induction of GSH-Px[TBH] activity in the L4-L5 instars and LS. In the forager bees, the enzyme activity was lower in the group treated with flumethrin than in the control group. This could have been due to unknown extrinsic environmental factors. In general, the average protein contents were lower in the flumethrin-treated group than in the control group. In the LS and pupal stage, and in the adult worker bees, the differences were significantly lower. This inhibition of growth could be due to metabolic costs resulting from exposure to toxicants.

Activities of Glutathione S-Transferase and Glutathione Peroxidases Related to Diet Quality in an Aphid Predator, the Seven-spot Ladybird, Coccinella septempunctata L. (Coleoptera: Coccinellidae(.

Larvae of Coccinella septempunctata were reared on three aphid diets, consisting of pure Rhopalosiphum padi, pure Metopolophium dirhodum, and an equal mix of these aphid species. In the pupal stage, the activities of three detoxifying enzyme systems - glutathione S-transferase (GST) with 1-chloro-2,4-dinitrobenzene as substrate, glutathione peroxidase with hydrogen peroxide as substrate (GSH-Px[H2O2]), and glutathione peroxidase with tert-butyl hydroperoxide as substrate (GSH-Px[TBH]) - were assayed. Growth rate, measured as the total protein content of the pupae, was significantly higher in the mixed-diet group than in the R. padi group, whereas that of the M. dirhodum group was intermediate. GST showed lower activity in larvae on a pure R. padi diet and a mixed aphid diet than on a pure M. dirhodum diet, whereas the variation in GSH-Px[TBH] was independent of diet. GSH-Px(H2O2) showed a significantly higher activity in the R. padi group than in the M. dirhodum group, whereas that of the mixed-diet group was intermediate. Thus, feeding on the low-quality aphid, R. padi, inhibited GST and activated GSH-Px(H2O2). The induction of GSH-Px[H2O2] indicated elevated oxidative stress. This may have been caused by toxic compounds in the R. padi.

Absorption of wheat starch in patients resected for left-sided colonic cancer.

Bacterial fermentation of carbohydrate in the colon, producing short-chain fatty acids (SCFA)--and especially butyrate--has been shown possibly to impede cell proliferation and regulate cell differentiation of colonocytes. In patients with diverticular disease or benign polyps in the colon a hyperabsorption of potato starch in the small intestine has been found. We have investigated the absorption of wheat starch in 15 patients radically resected for cancer in the descending or sigmoid colon, and the results were compared with those of 15 healthy controls. The starch malabsorption was quantified by the hydrogen breath test. The patients malabsorbed 2-14 g (median, 8 g) of 100 g wheat starch ingested, and the control group malabsorbed 3-11 g (median, 6 g) (P greater than 0.1). Mouth-to-cecum transit time for wheat starch and lactulose and the hydrogen production capacity after the lactulose standards were also similar in patients and controls. The results do not support the theory that hyperabsorption of starch is characteristic of patients with malignant disease in the large intestine.

Studies on the possible role of cattle nuisance flies, especially Hydrotaea irritans, in the transmission of summer mastitis in Denmark.

The summer mastitis pathogens Actinomyces pyogenes, Peptococcus indolicus, Bacteroides melaninogenicus ss. levii, Fusobacterium necrophorum and Streptococcus dysgalactiae were isolated from the polyphagous symbovine dipterans Hydrotaea irritans (Fallén) and Morellia sp. caught around dairy heifers on pasture, but not from the haematophagous species Haematobia irritans (L.), Haematobosca stimulans (Meigen), Culicoides sp. and Simulium sp. Secretions from clinical cases of summer mastitis proved to be sources of summer mastitis bacteria for more than 3 weeks despite antibiotic treatment and teat amputation. Taking into account the seasonal activity pattern of Hydrotaea irritans and its topographical distribution on grazing cattle, it appears evident that this fly may play a central role in the establishment and maintenance of the bacterial contamination with summer mastitis pathogens on the teats of healthy cattle. In the present study the survival of A.pyogenes and P.indolicus for 7 days in experimentally infected Hydrotaea irritans, as demonstrated by the recovery of these microorganisms from agar plates exposed to live infected flies, is described. However, experimental transmission of summer mastitis from sick to healthy heifers by Hydrotaea irritans proved unsuccessful.

Biochemical and clinical effects of an antioxidative supplementation of geriatric patients. A double blind study.

Ninety seven geriatric patients from two Danish homes for old people accepted to participate in a blinded experiment designed to counteract ageing phenomena. The subjects were split into two groups, i.e., the verum and the placebo group. The verum group received daily for one year an antioxidative cocktail consisting of: 300 micrograms selenium as L-selenomethionine, 45 mg zinc, 270 mg vitamin C, 2.7 mg vitamin A, 6 mg vitamin B-6, and 465 mg vitamin E (d-alfatocopherol). Furthermore, in order to enhance exchange in polyenoic acids, each subject received daily 250 mg gamma-linolenic acid. The placebo groups received similar looking pills and capsules without the active components. During one year in the verum group, the whole blood selenium, the hydrogen-dependent glutathione peroxidase (GSH-Px) of erythrocytes, and the vitamin E level in serum was found increased compared to the pretreatment values and to the placebo group. No change could be traced in the t-butylhydroperoxide dependent GSH-Px, an enzyme that also assays the glutathione-s-transferase. During the same period of time, the fasting levels of serum fatty acids and the content of lipofuscin in erythrocytes were estimated. Compared to the pretreatment values, the lipofuscin level declined significantly and the level of w-3 penta- and hexaenoic acids increased in the verum, but not in the placebo group. During the study period, slight, but significant improvements in psychological scores could be traced. Furthermore, the assays of bloodflow in different areas of the brain surface (i.e., the ISI values) revealed a general trend to improvement in all areas, when the ISI values were compared during treatment with the pretreatment values and the values in the placebo group.

Peptic ulcer complications and how to treat them.

The main complications to peptic ulcer are perforation, stenosis and bleeding. Diagnosis and treatment are discussed with special reference to the principles of 1st Department, Kommunehospitalet, Copenhagen. The three main complications to peptic ulcer disease include perforation, stenosis and bleeding. The etiology to peptic ulcer disease and the pathogenesis of ulcer disease complications are still poorly understood, although an imbalance between mucosa-protecting and -destructing factors seems to be of major importance. However, the introduction of neither H2 receptor antagonists nor the so-called mucosaprotection agents during the seventies and eighties significantly have reduced the frequency of peptic ulcer disease or the frequency of its complications (perforation 10 per cent, stenosis 10 per cent and bleeding 20 per cent of patients with peptic ulcer disease. The unchanged frequency of operation for peptic ulcer complications was confirmed in a recent study by A. Christensen et al. 1987. Their data suggested unchanged frequency of operations for ulcer complications prior to and following the introduction of H2 receptor antagonists (Fig. I and II) in a well defined population in Copenhagen.

Short-term prophylaxis with cefotaxime in colorectal surgery. A prospective, randomized trial.

In a controlled, randomized study the effect of penicillin and streptomycin on postoperative septic complications in colorectal surgery (penicillin, 2 ml, IU, intramuscularly, three times daily for a period of six days and concomitantly streptomycin, 0.5 gm, intramuscularly, two times daily for a period of four days) was compared with the effect of cefotaxime, 2 gm, intravenously, three times on the day of surgery. One hundred patients completed the study: 48 were treated with penicillin and streptomycin (Group 1) and 52 with cefotaxime (Group 2). Wound infection occurred in one patient (2.1 percent) in Group 1, but not in Group 2 (0%, N.S.). Rupture of the wound occurred in one patient in each group (2.1 percent vs. 1.9 percent, N.S.). Insufficiency of the anastomosis occurred in four patients in Group 1 (8.3 percent) and in one patient in Group 2 (1.9 percent). It is concluded that short-term prophylaxis with cefotaxime is as effective as long-term prophylaxis with penicillin and streptomycin.

Comparison of whole blood selenium values and erythrocyte glutathione peroxidase activities of normal individuals on supplementation with selenate, selenite, L-selenomethionine, and high selenium yeast.

The selenium levels and the glutathione peroxidase activity GSH-PX of whole blood and of erythrocytes, respectively, were determined in 139 normal Danes and related to sex and smoking habits. No differences were found in relation to sex apart from a higher GSH-PX activity of females when assayed with tertiary butyl hydroperoxide. Smokers showed significantly lower selenium values than non-smokers (p less than 0.05), but the two groups had identical GSH-PX activities. Individuals from the above-mentioned group were divided into four groups, receiving daily oral doses of 200 micrograms of selenium in the form of selenite, selenate, L-selenomethionine, and selenium as contained in yeast. Whole blood selenium values and the erythrocyte glutathione peroxidase activities were determined during three months of supplementation followed by a withdrawal period of four months. Both the inorganic selenium compounds and the organic derivatives gave rise to steady state levels of GSH-PX after one month of supplementation. However, the selenium levels in the groups receiving organic selenium showed a steady rise during the whole period, whereas those supplemented with inorganic selenium leveled off after a period of one to three months. The data for smokers and nonsmokers revealed identical results when organic selenium was supplemented. However, selenite gave rise to significantly higher selenium levels and GSH-PX activities in smokers than in non-smokers. Less significant (p less than 0.08) elevations of both parameters were also observed among the smokers in the selenate group. By taking both the selenium level and the GSH-PX activity into consideration, organic selenium (i.e., L-(+) selenomethionine) was judged to be more bioavailable than selenite and selenate.

Selenium in chronic neurologic diseases. Multiple sclerosis and Batten's disease.

The selenium levels in whole blood and the activity of glutathione peroxidase in hematogenous cells of normal Danes have been defined taking into account sex and confounding factors such as smoking and aging. No differences related to sex could be found with regard to the selenium level, and peroxidase activity assayed with hydrogen peroxide. However, the peroxidase activity assayed with t-butyl hydroperoxide was higher in females than in males (p less than .05). The peroxidase activities are dependent on age. Thus, the peroxidase levels assayed with both substrates show a minimum value in the age group from 40 to 50 yr for both smokers and nonsmokers. Smokers did show more homogeneous values as a function of age than nonsmokers. Smokers had significantly lower selenium values than nonsmokers, but glutathione peroxidase values identical with those of nonsmokers. Multiple sclerosis (MS) patients suffer from a chronic relapsing/remitting demyelinating disease. A theory explaining the pathogenesis of MS concerns increased stickiness of cellular plasma membranes, hampering normal vascular function of the brain. In agreement with that theory, the present communication demonstrates significantly lowered selenium values and lowered glutathione peroxidase activities of major types of hematogenous cells. In close agreement with these findings, hematogenous cells in MS show increased peroxidation rates. A nonblinded biochemical dietary experiment on MS patients showed that all abnormalities could be normalized by daily intake of selenium, vitamin E, and vitamin C. Batten's disease is a recessive inherited neurodegenerative disorder clinically characterized by progressive loss of vision, epilepsy, and dementia. Neuropathologically, this disease is characterized by storage of lipofuscin in nervous tissue. We have in a few cases documented a low selenium status and low glutathione peroxidase activities of hematogenous cells. As in MS, we normalized the biochemical abnormalities by an antioxidative treatment. Like in similar Finnish studies, the biochemical parameters can be normalized. Further, the Finnish studies indicate it possible by an antioxidative treatment to inhibit progression of the mental deterioration. The data presented will be discussed in relationship both to specific pathological parameters of the diseases and to the low dietary energy expenditures of handicapped immobile patients.

The effects of a glycine antagonist (strychnine) on cortically induced rhythmical jaw movements in the anesthetized guinea pig.

We have investigated the effects of systemic administration of a glycine antagonist, strychnine, on rhythmical jaw movements (RJMs) induced by repetitive stimulation of the masticatory area of the guinea pig cerebral cortex. It was found that after strychnine administration (0.4 mg/kg), the frequency of the cortically induced RJMs was minimally affected, whereas the burst durations of the digastric EMG during the jaw opening phase of the RJM cycle were dramatically increased. These data suggest that the neuronal network (central pattern generator (CPG)) which is responsible for the production of rhythmical jaw movements is not critically dependent upon glycine for the genesis of the basic oscillatory rhythm. On the other hand, glycine synapses are involved with the neuronal mechanisms which are responsible for controlling the burst durations of the digastric muscle during the jaw opening phase of each rhythmic jaw movement cycle.

Complications following postoperative combined radiation and chemotherapy in adenocarcinoma of the rectum and rectosigmoid. A randomized trial that failed.

A randomized multicenter trial was started to evaluate the effect of irradiation combined with 5-fluorouracil and methotrexate on survival after surgery for rectal and rectosigmoidal carcinoma, Dukes' stages B and C. The trial was terminated prematurely after entrance of 34 patients due to frequent and serious complications. Three patients died as a direct consequence of the adjuvant treatment.