Buchbesprechungen

Ohne Zusammenfassung     

Vitalitätsansprache von Fichten auf der Grundlage spektraler Rückstrahlungsmessungen

Zusammenfassung Ziel des Projekts ist die Erarbeitung spektraler Rückstrahlungscharakteristiken von Einzelb?umen und Bestandesoberfl?chen zur Erfassung und kontinuierlichen Beobachtung von Vitalit?tsunterschieden bzw. Sch?digungen an Waldb?umen, insbesondere an Fichten. (Ammer et al. 1983;Hildebrandt 1976). Die für die Spektroradiometermessungen wichtigen objektunabh?ngigen Einflu?parameter wie Sonnenstand, Me?richtung, Neigungswinkel, ?ffnungswinkel und Beleuchtungsverh?ltnisse sind durch eine Vielzahl von Voruntersuchungen bestimmt worden. Erste Me?ergebnisse an Testfl?chen im H?glwald und im Erbersberger Forst lassen deutliche Reaktionen im Spektralverhalten erkennen, die auf Vitalit?ts- und ph?nologische Unterschiede zurückgeführt werden k?nnen.

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Judging vigor of spruces on the basis of spectral reflection measurements

Summary Objective of the research project is the evaluation of characteristic spectral signatures for single trees and stands to assess and continuously monitor differences in vigor, or damages of trees, respectively, especially for spruce. The object-independent parameters which are important for the spectro-radiometer measurements, such as angle and elevation of the sun, inclination, measuring direction, angle of view, and illumination have been determined by numerous previous investigations. First results from the testsites “H?glwald” and “Ebersberger Forst” show distinct differences in the spectral curves which can be related to different degrees of vigor and phenology.

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Beitrag Nr. 16 der H?glwald-Serie 1986     

Auswirkungen des Einsatzes entomopathogener Nematoden im Freiland auf die Nichtzielfauna, 1. Teil: Coleoptera

Zusammenfassung Von 1988 bis 1990 wurden in vier verschiedenen Gebieten (Buchen-Eichen-Mischwald, Kiefernwaldrand, Getreidefeld und Obstgarten) in der Umgebung von Darmstadt Freilandversuche mit den NematodenstämmenSteinernema feltiae und denHeterorhabditis-Stämmen HL 81 und HD 01 durchgeführt, um deren Auswirkungen auf die Nichtzielfauna zu untersuchen. Die Aufwandmengen lagen bei 0,6 bis 1,0×10⁶ Nematodenlarven/m². Die Käferfauna wurde mit Hilfe von Bodenphotoeklektoren über mehrere Wochen bis Monate auf den nematodenbehandelten Flächen und auf unbehandelten Kontrollflächen erfaßt. Den Schwerpunkt der Auswertungen bildeten die Familien Carabidae, Staphylinidae, Chrysomelidae, Curculionidae und Elateridae. Die Ergebnisse zeigten, daß anscheinend nur wenige Arten einzelner Käferfamilien durch den Nematodeneinsatz beeinträchtigt wurden. Andere Arten traten dagegen auf den behandelten Flächen wesentlich häufiger auf als auf den Kontrollflächen. Mögliche Ursachen für diese Effekte werden diskutiert.

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From 1988 to 1990 field trials with entomopathogenic nematodes were conducted in four different areas (beech-oakforest, pine-forest margin, crop field and orchard) in the surroundings of Darmstadt (FRG). The nematodes used in the trials wereSteinernema feltiae Fil. f.filipjew (syn.S. bibionis Bov.) and theHeterorhabditis strains HL 81 and HD 01; the nematode concentration was 0.6 to 1.0×10⁶ nematodes/m². The coleopteran fauna of treated areas and untreated control plots was investigated by means of photoeclectors. Most attention was paid to the coleopteran families Carabidae, Staphylinidae, Chrysomelidae, Curculionidae and Elateridae. Only a few species of these families seemed to be affected by the nematode application; some other beetle species could be collected even in higher numbers on the treated plots than on the untreated control plots. Possible reasons for these effects are discussed.

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Mit einer Abbildung und 2 Tabellen     

The bioactivity of gonadotropin releasing hormones and its regulation in the gilthead seabream,Sparus aurata: in vivo andin vitro studies

Thein vivo andin vitro potency of native and modified forms of gonadotropin releasing hormone (GnRH) to release gonadotropin (GtH) was studied inSparus aurata and correlated with their relative susceptibility to degradation by cytosolic-bound enzymes of the pituitary, kidney, and liver. Salmon (s) GnRH and luteinizing hormone-releasing hormone (LHRH) are equipotent whereas analogs of these peptides ((D-Arg⁶-Pro⁹NET)-sGnRH, (D-Ala⁶-Pro⁹NET)-LHRH, (D-Trp⁶)-LHRH) are superactive in inducingin vivo GtH release (at 10 μg/kg body weight). In anin vitro superfusion system of pituitary fragments all analogs are equipotent to the native peptides (at 10⁻¹⁰ to 2.5 × 10⁻⁷M). sGnRH and LHRH are rapidly degraded by cytosolic peptidases of the pituitary, liver, and kidney. The preferred site of cleavage is the Tyr⁵-Gly⁶ bond. Substitution of the position 6 glycine by D-amino acids renders the 5–6 bond resistant to degradation and shifts the main site of cleavage to the Pro⁹-Gly¹⁰NH₂ bond. Substitution at position 6 (as above) and at position 10 with Pro⁹NET results in analogs that are resistant to degradation. We propose that enzymatic cleavage terminates GnRH bioactivityin vivo and thus increased resistance to degradation is a major determinant of GnRH analog superactivity.     

Temporohyoid osteoarthropathy in the horse

Temporohyoid osteoarthropathy (THO) is a well‐recognised clinical entity in horses. Temporohyoid osteoarthropathy is characterised by progressive osseous proliferation of the proximal portion of the stylohyoid and petrous temporal bones, and is generally described as a disease of middle‐aged horses. More recent reports also attribute a variety of clinical syndromes in young horses to THO, requiring a diversification of approaches to confirm the diagnosis and its significance, and to guide conservative and surgical treatment options. This commentary will review the purported aetiology, clinical syndromes, available diagnostic tests and treatment options of equine THO.     

Evaluation of the urinary Cortisol: creatinine ratio in the diagnosis of hyperadrenocorticism in dogs

The diagnostic accuracy of the urinary cortisol:creatinine ratio (CCR), with the cortisol being measured by ELISA, was evaluated by subjecting data from 18 dogs with and 20 dogs without hyperadrenocorticism to recelver operating characteristic (ROC) curve analysis. The area under the ROC curve (W 0–93, SE_w 0–044) was much higher than 045, indicating that the CCR did distinguish between dogs with and without hyperadrenocorticism.A cutoff value of about 60 × 10^-6 was assoclated with the highest sensitivity (1.0)and speciflcity (0–85). At the disease prevalence rate of the present study (0 47), the positive and negative predictive values were 0–87 and 1.0, respectively. These numbers indicate that canine hyperadrenocorticism may be safely excluded when the CCR Is below 60 × 10^-6 but that a test of higher specificlty (eg, the ACTH stimulation test) should be used to confirm the diagnosis of canine hyperadrenocorticism when the CCR Is above 60 × 10^-6.     

Immunization of cattle against Theileria parva bovis and their exposure to natural challenge

Theileria parva bovis isolates were tested for their immunizing capacity under natural field challenge on Willsbridge Farm in the highveld of Zimbabwe. Fifteen susceptible Sussex yearlings were immunized with the Boleni stock and 15 with a mixture of three isolates from the farm, using tick-derived sporozoite stabilates. No chemoprophylaxis was used. A dose of 0.1 ml of stabilate appeared to be safe in preliminary laboratory experiments, but the reactions were severe in the Sussex cattle and one died despite treatment. Twenty-nine immunized animals and 10 controls first experienced a mild infection, starting about 15 days after their arrival at the farm. Ten of the immunized animals and four controls had schizonts in peripheral lymph nodes for variable periods; one third of those had pyrexia. Nymphal Rhipicephalus appendiculatus ticks applied to three of the reacting immunized calves transmitted Theileria taurotragi to two animals and T. parva to a third. A second Theileria infection, due to T. parva bovis, was detected shortly after the first one. Schizonts were detected in seven out of 10 controls. Pyrexia was more severe and prolonged. Two of the controls died of theileriosis. At the same time schizonts were seen in three immune animals and eight of them had short periods of pyrexia. Intercurrent infections with Babesia bigemina, Borrelia theileri and Eperythrozoon were detected and may have contributed to the fever. Tick infestations were low during the exposure. In the second year of exposure, four out of eight new control animals had severe reactions, and one died. None of the immunized animals became ill, but one animal from the first year control group, which had not reacted previously, had clinical theileriosis. It is concluded that immunization provided an effective protection against field challenge.