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  • 1
    Electronic Resource
    Electronic Resource
    Observations of thermospheric neutral winds within the polar cusp and the auroral oval using a Doppler imaging system (DIS) (1998)
    Springer
    Annales geophysicae 16 (1998), S. 1461-1474 
    Details
    ISSN: 0992-7689
    Keywords: Ionosphere (Polar ionosphere) ; Meteorology and atmospheric dynamics (thermospheric dynamics; instruments and techniques)
    Source: Springer Online Journal Archives 1860-2000
    Topics: Geosciences , Physics
    Notes: Abstract Two Doppler imaging systems (DIS) or wide-field imaging Fabry-Perot interferometers (FPI), have recently been commissioned, one at the Auroral Station, Adventdalen, Longyearbyen, Svalbard, and the second at the IRF, Kiruna, Sweden. These instruments can provide wide-field (600 * 800 km) images of neutral wind flows in the upper thermosphere, by measuring the Doppler shift of the atomic oxygen forbidden near 630 nm, which is emitted from an altitude of approximately 240 km. From the instrument in Svalbard, at mid-winter, it is possible to observe the dayside polar cusp and the polar cap throughout the entire day, whereas from Kiruna, the night-time auroral oval is observable during the hours of darkness. Measurements of thermospheric dynamics from the DIS can be used in conjunction with observations of ionospheric plasma flows and thermal plasma densities by the EISCAT-Svalbard radar (ESR) and by EISCAT, along with other complementary observations by co-located instruments such as the auroral large-scale imaging system (ALIS). Such combined data sets will allow a wide range of scientific studies to be performed concerning the dynamical response of the thermosphere and ionosphere, and the important energetic and momentum exchange processes resulting from their complex interactions. These processes are particularly important in the immediate vicinity of the polar cusp and within the auroral oval. Early results from Svalbard in late 1995 will be discussed. The DIS in Kiruna observed two interesting geomagnetic disturbances in early 1997, the minor geomagnetic storm of 10, 11 January, and the disturbed period from 7–10 February. During these events, the thermospheric wind response showed some interesting departures from the average behaviour, which we attribute to the result of strong and variable Lorenz forcing (ion drag) and Joule and particle heating during these geomagnetic disturbances.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s00585-998-1461-3
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  • 2
    Electronic Resource
    Electronic Resource
    Mycosporine-like amino acids: possible UV protection in eggs of the sea hare Aplysia dactylomela (1998)
    Springer
    Marine biology 130 (1998), S. 389-396 
    Details
    ISSN: 1432-1793
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract We investigated mycosporine amino acid (MAA) involvement as protective sunscreens in spawn of the sea hare Aplysia dactylomela to determine if adult diet and ultraviolet (UV) exposure affected the UV sensitivity of developing embryos. Adults were fed a red alga rich in MAAs (Acanthophora spicifera) or a green alga poor in MAAs (Ulva lactuca). Adults on each diet were exposed for 2 wk to ambient solar irradiance with two types of acrylic filters; one allowed exposure to wavelengths 〉275 nm (designated UV) and one to wavelengths only 〉410 nm (designated NOUV). Spawn from each adult group was likewise treated with UV or NOUV and monitored during development for differences in mortality and metabolic rate (measured as oxygen consumption: V˙ O2). Also recorded were number of eggs or embryos per capsule, times to hatching, hatching success, size at hatching, and V˙ O2 of adults. Spawn from adults eating red algae was almost twice as rich in MAAs as spawn from adults eating green algae, suggesting that MAA content is diet-related. Although overall quantities of MAAs in the spawn reflected MAA contents of the adult diet, specific MAAs were differentially sequestered in the spawn. Thus, porphyra-334, found in high concentration in Aplysia dactylomela's preferred red algal food, was present in only low concentration in the spawn. Conversely, mycosporine-glycine, in low concentration in red algal food, was the most abundant MAA in the spawn. UV treatment of adults had no effect on quantities of MAAs in the spawn. Adults exposed to UV had significantly higher V˙ O2s and spawned twice as often. The UV-treated adults produced spawn with significantly higher V˙ O2s and their embryos developed to hatching sooner. The only significant effect of UV exposure of the spawn was to reduce the percentage of veligers hatching from 71 to 50%. There was no significant effect on hatching time or size of the veligers at hatching, nor on number of eggs per capsule.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002270050259
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  • 3
    Electronic Resource
    Electronic Resource
    Multiple Geochemical and Isotopic Approaches for Assessing Ground Water NO3− Elimination in a Riparian Zone (1999)
    Oxford, UK : Blackwell Publishing Ltd
    Ground water 37 (1999), S. 0 
    Details
    ISSN: 1745-6584
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Energy, Environment Protection, Nuclear Power Engineering , Geosciences
    Notes: During the last 40 years, nitrate (NO3−) has become one of the most common ground water contaminants. Stream riparian zones are considered important ecological ecotones that decrease the NO3− load of ground water discharging into streams. This study uses NO3−/Cl− ratios, natural abundances of15N and18O in NO3−, and an in situ15NO3− tracer experiment to evaluate NO3− reducing processes occurring in ground water within a narrow grassed buffer strip bordering a stream in an agricultural watershed. The NO3−/Cl− ratios (1.9-0.0 [M/M]) indicate that both NO3− consuming processes and mixing of two ground water flow regimes with different NO3− loads contribute to the drop observed in ground water NO3− concentrations within the riparian zone. δ15N and δ18O of the ground water NO3− within the riparian zone (δ15N = 5.1 to 48.8 %c; δ18O = 1.1 to 17.8 %c) were enriched compared to the ground water below the adjacent cultivated field (δ15N = 3.8 to 10.1 %0; δ18O = 0.5 to 6.2 %c). A significant linear relationship (r2=0.97) between ground water δ15N and δ18O in NO3− was found, which is consistent with NO3− consumption by microbial denitrification. The estimated enrichment factors for15N are a factor of 1.5 higher than for18O. The in situ15NO3− tracer experiment conclusively confirmed that denitrification is occurring within the ground water of the riparian zone and demonstrates that denitrification rates can be directly measured in situ.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1111/j.1745-6584.1999.tb01124.x
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  • 4
    Electronic Resource
    Electronic Resource
    Low-temperature photochromic response of phosphorus-doped bismuth silicon oxide (1995)
    [S.l.] : American Institute of Physics (AIP)
    Journal of Applied Physics 78 (1995), S. 2010-2014 
    Details
    ISSN: 1089-7550
    Source: AIP Digital Archive
    Topics: Physics
    Notes: Phosphorus is one of several dopants that electronically compensate the native deep donor responsible for the yellow coloration observed in bismuth silicon oxide (BSO). Low-temperature optical absorption measurements of a series of Czochralski-grown P-doped BSO crystals show that ∼0.1–0.15 at. % P is needed in the sample to fully remove the yellow coloration. The absorption cutoff in the fully compensated P-doped sample was at 3.2 eV while compensated Al- and Ga-doped samples cutoff at 3.35 eV. Excitation at 10–15 K with near band-edge light produces photochromic absorption bands. In the lightly-doped (partially bleached) samples these bands were identical to those observed in undoped BSO. In the fully bleached sample a new spectrum was observed. Its major contribution was a band centered near 1.8 eV with a weaker absorption in the blue-green. By comparison with the spectra observed in undoped and in Al-doped material before and after photoexcitation it is believed that the 1.8 eV band is due to the [PO4]− center and that the broad 2.45 eV band observed in Al- and Ga-doped BSO is due to the [BiO4]0 center. © 1995 American Institute of Physics.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1063/1.360176
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  • 5
    Electronic Resource
    Electronic Resource
    Enhancement of β-Amyloid Peptide Aβ(1–40)-Mediated Neurotoxicity by Glutamine Synthetase (1995)
    Oxford, UK : Blackwell Science Ltd
    Journal of neurochemistry 65 (1995), S. 0 
    Details
    ISSN: 1471-4159
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Abstract: The β-amyloid peptide (Aβ), a main constituent in both senile and diffuse plaques in Alzheimer's disease brains, was previously shown to be neurotoxic and to be able to interact with several macromolecular components of brain tissue. Previous investigations carried out in our laboratory demonstrated free radical species formation in aqueous solutions of Aβ(1–40) and its C-end fragment, Aβ(25–35). Toxic forms of Aβ rapidly inactivate the oxidation-sensitive cytosolic enzyme glutamine synthetase (GS). In this regard, we suggested and subsequently demonstrated that Aβ radicals can cause an oxidative damage of cell proteins and lipids resulting in disruption of membrane functions, enzyme inactivation, and cell death. Because GS can be a substrate for Aβ-derived oxidizing species, the present study was conducted to determine if GS could protect against Aβ neurotoxicity. In contrast to this initial hypothesis, we here report that GS significantly enhances the neurotoxic effects of Aβ(1–40). The Aβ-mediated inactivation of GS was found to be accompanied by the loss of immunoreactive GS and the significant increase of Aβ(1–40) neurotoxicity.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1471-4159.1995.65041899.x
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  • 6
    Electronic Resource
    Electronic Resource
    Gastrointestinal autonomic nerve tumours: a report of nine cases (1996)
    Oxford, U.K. and Cambridge, USA : Blackwell Science Ltd
    Histopathology 29 (1996), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: We describe the clinicopathological features of gastrointestinal autonomic nerve tumours in nine patients where the diagnosis was confirmed by electronmicroscopy. Most patients presented with abdominal pain. At laparotomy, large intra-abdominal tumour masses were found which tended to be cystic and haemorrhagic. The predominant histological patterns were nests, sheets and fascicles of spindle and epithelioid cells. Immunohistochemistry showed positive staining for neuron specific enolase (9/9), PGP 9.5 (9/9), NKI/C3 (7/9), vimentin (7/9), α-smooth muscle actin (5/9), vasoactive intestinal peptide (3/9) and CD34/QBend10 (2/9). Grimelius staining was positive in two of nine cases. All tumours were negative for CAM 5.2, chromogranin, synaptophysin, Leu 7, neurofilament protein, muscle-specific actin (HHF-35) and desmin (D33). Ultrastructural examination showed cellular processes and dense-core granules in all cases. Three tumours had microtubules and/or intermediate filaments, particularly in cell processes. Skeinoid fibres were seen in three cases. No convincing synapses or small (synaptic-type) vesicles were identified. There was no evidence of epithelial, smooth muscle or nerve sheath differentiation. Two patients died due to tumour, two died of unknown causes and the remainder are alive 2–44 months after presentation. Four of the five survivors have recurrent/residual intra-abdominal tumour. So-called gastrointestinal autonomic nerve tumours are apparently slow-growing malignant tumours showing neuronal differentiation. Four cases arose in the mesentery/retroperitoneum or omentum rather than bowel wall and therefore a more appropriate nomenclature might be intra-abdominal stromal tumour with neuronal differentiation.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1996.d01-502.x
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  • 7
    Electronic Resource
    Electronic Resource
    Angiotropic lymphoma with endocrine involvement (1997)
    Oxford, UK : Blackwell Science Ltd
    Histopathology 31 (1997), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Aims: Two cases of angiotropic high-grade B-cell lymphoma are described in which involvement of endocrine glands was a prominent feature. Methods and results: One patient had marked unilateral adrenomegaly due to lymphoma within adrenal blood vessels. He is alive 5 years after presentation following combination chemotherapy. The diagnosis was made at autopsy in the second patient who presented with pyrexia of unknown origin and had hypothyroidism and a thyroid nodule. The thyroid gland and pituitary showed striking involvement by angiotropic lymphoma and the thyroid nodule was a cavernous haemangioma heavily colonized by lymphoma cells. Conclusions: Our cases illustrate endocrine organ manifestations of this rare disease. The condition may respond to combination chemotherapy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1997.2260835.x
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  • 8
    Electronic Resource
    Electronic Resource
    Histiocytic necrotizing lymphadenitis (Kikuchi–Fujimoto disease): continuing diagnostic difficulties (1998)
    Oxford, U.K. and Cambridge, USA : Blackwell Science Ltd
    Histopathology 33 (1998), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: Aims: To describe the clinicopathological and immunophenotypic features of 25 cases of Kikuchi–Fujimoto disease (K–F), which remains a poorly recognized entity and is still frequently confused with malignant lymphoma, and to discuss the main diagnostic problems experienced by the referring pathologist.〈section xml:id="abs1-1"〉〈title type="main"〉Methods and resultsHaematoxylin and eosin sections of 27 lymph node biopsies were re-examined. Immunostains for B-lymphocytes, T-lymphocytes and macrophages were performed. Clinical and follow-up data were obtained through a questionnaire to the referring pathologist or from the patients' notes where available. The suggested initial diagnoses are discussed. The lymph nodes showed a necrotizing process characterized by patchy or confluent areas of necrosis associated with karyorrhexis and absence or paucity of granulocytes. This was associated with a proliferation of large blastic cells consisting of a mixture of T-lymphocytes and histiocytes. Fragmentation of the biopsy was a frequent feature. The diagnosis of K–F was suggested by the referring pathologist in three cases only. The most common suggested diagnosis was that of a non-Hodgkin's lymphoma.〈section xml:id="abs1-2"〉〈title type="main"〉ConclusionThis series documents continuing difficulties in the diagnosis of Kikuchi–Fujimoto disease in the UK and emphasizes that cases are still being mistakenly diagnosed as malignant lymphomas. The diagnosis of Kikuchi–Fujimoto disease merits active consideration in any nodal biopsy showing fragmentation, necrosis and karyorrhexis, especially in young women presenting with cervical lymphadenopathy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1998.00469.x
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  • 9
    Electronic Resource
    Electronic Resource
    BEHAVIORAL MANIPULATION METHODS FOR INSECT PEST-MANAGEMENT (1997)
    Palo Alto, Calif. : Annual Reviews
    Annual Review of Entomology 42 (1997), S. 123-146 
    Details
    ISSN: 0066-4170
    Source: Annual Reviews Electronic Back Volume Collection 1932-2001ff
    Topics: Biology
    Notes: Abstract We discuss methods using stimuli to manipulate behavior of a pest for the purpose of protecting a valued resource. The methods are divided into two categories: those that manipulate behavior over a long distance, e.g. volatile chemicals, visual, and auditory stimuli, and those that manipulate behavior at a short distance (〉1 cm), e.g. involatile chemicals. Particular emphasis is placed on methods that have been developed through studies of pest behavior and on combining stimuli to increase efficacy. Future prospects for behavioral manipulation methods in pest management are discussed.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1146/annurev.ento.42.1.123
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  • 10
    Electronic Resource
    Electronic Resource
    Clinicopathological characteristics of peripheral primitive neuroectodermal tumour of skin and subcutaneous tissue (1997)
    Oxford, UK : Blackwell Science Ltd
    Histopathology 31 (1997), S. 0 
    Details
    ISSN: 1365-2559
    Source: Blackwell Publishing Journal Backfiles 1879-2005
    Topics: Medicine
    Notes: To study the clinical and pathological features of primary malignant peripheral primitive neuroectodermal tumours (PNETs) of the skin and subcutaneous tissue, to discuss the differential diagnosis, and to review the existing literature on these tumours.〈section xml:id="abs1-2"〉〈title type="main"〉Methods and results:Eight cases of PNETs presenting in the skin and subcutaneous tissue were identified from the pathology records of the Christie Hospital, Manchester. Detailed immunohistochemical studies were performed on all cases and seven tumours were subjected to electron microscopic examination. Detailed clinical and follow-up information was obtained on seven cases. Six tumours occurred in children and adolescents and two were seen in young adults (age range, 8–36 years). No sex or site predilection was observed. Five tumours occupied the dermis and subcutis and three were entirely located in the subcutaneous tissue. Microscopically, they were composed of small round cells and seven tumours contained glycogen. Only one tumour focally exhibited Homer–Wright rosettes and neuropil. Two tumours contained rhabdoid or plasmacytoid cells in places and all cases showed microcystic and pseudovascular spaces. Immunostains revealed MIC2 (8/8), NSE (7/8), PGP9.5 (7/8), β2 microglobulin (7/8), neurofilament protein (6/8), S100 protein (3/8), synaptophysin (2/8) and Leu-7 (1/8) positivity. Anomalous cytokeratin (4/8), desmin (2/8), myoglobin (2/8), NKIC3 (4/8) and GFAP (1/8) staining was also noted. Ultrastructurally, neuroendocrine granules were detected in five cases and one case exhibited microtubules in processes. Adequate follow-up information was available in four cases. One patient died of metastatic disease. One child developed axillary lymph node metastasis but is alive with no evidence of disease 96 months after treatment. Two other patients are alive with no residual or recurrent disease 44 and 52 months after excision and radio/chemotherapy.〈section xml:id="abs1-3"〉〈title type="main"〉Conclusion:PNETs are rare malignant small round cell tumours of the skin and subcutaneous tissue which are probably underdiagnosed. A correct diagnosis can be made on light microscopic features, demonstration of neuroendocrine granules on electron microscopy and a combination of MIC2, β2 microglobulin, and more than one neural marker positivity. These neoplasms should be differentiated from other cutaneous neoplasms composed of small round cells. The number of cases of cutaneous PNETs studied so far is rather small, and no firm conclusion can be drawn about their behaviour but long-term survival is possible in some cases.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1046/j.1365-2559.1997.2770865.x
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