A GPS logger and software for analysis of homing in pigeons and small mammals

A detailed analysis of homing in pigeons and small mammals has remained difficult because the paths of the animals could not be reconstructed precisely. Here, we describe a lightweight global position system (GPS) data logger (35 g including battery and casing; 40 x 68 x 18 mm) that records the flight of pigeons and the path of dogs with an accuracy of +/-12 m. With one battery, the logger runs in continuous mode (1 fix/s) for 3.5 h and in power-saving mode (1 fix/5 s) for about 16 h, and stores a maximum of 100,000 data points that are downloaded to a PC. A module of our public domain software WINTRACK permits a detailed numerical and graphical analysis of path geometry, phases of resting and moving, and path similarity. The device can be adapted to different species provided that satellite signals can be received reliably and that the loggers can be recovered. We expect it to be useful for testing hypotheses about pigeon homing, assessing natural spatial behavior and orientation of many species, and anticipate further miniaturization.     

Grenzschichtdicke und Sauerstoffversorgung des Herzens bei trainierten und nicht trainierten Fröschen

Zusammenfassung Durch die Analyse der spongiösen Wandstruktur am überlebenden, intakten Froschherzen gelingt es nachzuweisen, daß mit steigendem Herzgewicht die durchschnittliche Dicke der Muskelbalken im Inneren des Herzens (Balkendicke) unverändert bleibt. Die durchschnittliche Dicke der Muskelwand an den blinden Enden der Spongiosaspalten dicht unter der Herzoberfläche (Gewölbedecke) bleibt ebenfalls bei kleineren und mittleren Fröschen von 60–130 g Gewicht (5,5–10,5 cm Kopf-Steiß-Länge) gleich, sofern keine Capillaren am Ventrikel ausgebildet werden. Bei Fröschen mit capillarisierten Ventrikeln nimmt die Gewölbeschichtdicke zu, und zwar um 44% im Bereich der nicht capillarisierten Anteile und um 100% im Bereich der capillarisierten Anteile im Vergleich zu den Gewölbeschichtdicken gefäßloser Ventrikel. Damit entsprechen sich die Versorgungsschichtdicken der Muskelbündel im Inneren des Herzens und an den äußersten Herzwandanteilen capillarisierter Bezirke. Die notwendige Versorgungsschichtdicke für den pO₂ des gemischt arteriell-venösen Blutes im Froschherzventrikel dürfte demnach bei etwa 24 liegen.In Arbeitsversuchen, bei denen eine Anzahl von Fröschen einem Schwimmtraining unterzogen wurden, konnte eine Herzhypertrophie erzielt werden. Die Muskulatur der Gewölbeschichtdicke nahm dabei, verglichen mit den entsprechenden Werten einer Gruppe gleich schwerer Frösche, statistisch signifikant bis zu einem durchschnittlichen Wert von 28,7 zu. Die Balkendicken blieben unverändert. Die durchschnittliche Gewölbeschichtdicke erreichte nicht die Gewölbeschichtdicke der capillarisierten Ventrikelgebiete anderer Tiere. Eine vermehrte Capillarisation konnte an den Ventrikeln der trainierten Frösche nicht festgestellt werden. Wahrscheinlich war die Dauer unseres Versuches, der sich über 6 Wochen erstreckte, zu kurz bemessen.

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Summary By analyzing the spongy wall structure of the surviving intact frog heart it is possible to show that with increasing heart weight the average thickness of the muscle bundles within the heart remains unchanged. The average thickness of the muscle wall at the blind ends of the spongiosa fissures near to the heart surface remains equal in the case of smaller frogs and frogs of 60–130 g weight (5.5–10.5 cm from head to breech) too, provided that no capillaries are being formed at the ventricle. In the case of frogs with capillarized ventricles the thickness of the muscle wall at the blind ends grows bigger in comparison to the thickness of that of ventricles without vessels: in the area of not capillarized parts by 44% and in the area of capillarized parts by 100%. So the thickness of the supply layers of the muscle bundle within the heart and of the muscle wall at the blind ends of the capillarized areas are equivalent. The thickness of the supply layer required for the pO₂ of the mixed arterial-venous blood in the frog heart ventricle might, therefore, amount to about 24 .In experiments with frogs, which were subject to a special swim training, a cardiac hypertrophy could be observed. Compared to the corresponding values of a group of frogs, weight was equal, the muscle wall at the blind ends grew bigger up to an average value of 28.7 , which is statistically significant. The thickness of the bundles remained unchanged. The average thickness of the wall at the blind ends did not reach that of the capillarized ventricle areas of other animals. An increased capillarization at the ventricles of the trained frogs could not be observed; most probably the 6 weeks of our experiment did not suffice.

     

Immunohistochemistry and in situ hybridization of the androgen receptor in the developing human prostate

 As it is suggested that the androgen receptor mechanism is required for prostatic development, we attempted to determine the appearance, expression and distribution of the androgen receptor in embryonic, infantile and pubertal human prostate. Using mono- and polyclonal antibodies and a digoxigenin-labeled 713 bp riboprobe, the androgen receptor expression in paraffin sections of fetal, infantile, and pubertal prostates was studied at the protein and RNA level. Under highly standardized conditions, application of the polyclonal antibodies resulted in a weak cytoplasmic and nuclear labeling of the epithelium of fetal glands. No immunoreaction was obtained with monoclonal antibodies. Applying the polyclonal antibody to pubertal and adult specimens, immunoreactivity of the androgen receptor was positive in nuclei of adluminal and basal epithelial cells, in interstitial and vascular smooth muscle cells and vascular endothelium, whereas ganglionic cells and enteroendocrine cells were negative. In situ hybridization with the digoxigenin-labeled riboprobe gave clear positive results already in epithelium of very young fetal specimens. A semiquantitative visual evaluation of in situ hybridizations showed that intermediate intensity of expression was increased in pubertal and adult specimens, whereas strong expression was reduced in prostatic epithelium. Conclusions: The essential findings are: (1) an early expression of androgen receptor mRNA in the fetal prostate; (2) no immunoreaction of monoclonal antibodies against the androgen receptor in the same specimens, (3) a decrease of androgen receptor mRNA expression, but increase in immunoreactivity of the androgen receptor protein with the onset of glandular maturation during puberty. Accepted: 29 September 1997     

A TLC screening program for 170 commonly used pesticides using the corrected Rf value (R f c value)

Summary This article reports TLC data (corrected R_f values; R _f ^c values) of 170 commonly used pesticides which are regularly encountered in toxicological analysis. Silica gel was used as the stationary phase and three binary systems were chosen as solvents.     

Zur Anwendung des Rektaltemperatur-Todeszeit-Nomogramms am leichenfundort

Summary The application of the rectal temperature time of death nomogram at the scene of death by 11 authors from 6 lego-medical institutes resulted in a standard deviation of the differences between nomographic and real death time of ± 1.3 h in 46 cases (group I) with met requirements and clearly defined points of contact, nevertheless, including 9 cases with a more progressive cooling (0.5 > Q 0.2). In cases with a real death time of more than 4 h (N = 26) the standard deviation was ± 1.0 hours corresponding to permissible variation of 95% of ± 2.0 hours. Consequently, the permissible variation of 95% was much smaller than that suggested by the nomogram. The nomographic death time interval did not agree with the real one in 5 cases out of additional 30 cases with recognizably unsure points of contact (group II).     

Thoracic wall and lung trauma. Diagnosis, clinical aspects, surgical indications and technic

Diagnosis, pathophysiology, clinical course, indication for and technique of operative procedure are described for treatment of flail chest, pneumothorax, hematothorax, lung rupture and contusion, and for tracheobronchial injuries. A simple "finger-troicart" technique for thoracocentesis and chest tube is mentioned as well as the value of early and simultaneous fiberoptic exploration of the trachea, bronchi and esophagus.     

Immunological characterization and localization of the Na+/Ca2(+)-exchanger in bovine retina

The sodium/calcium exchanger was purified from bovine retinal rod outer segment membranes and used for the immunization of New Zealand White rabbits. A polyclonal antibody was produced which was found to bind specifically to the 230 kDa Na+/Ca2(+)-exchanger protein as assessed by Western blotting. The antibody did not bind to the high-molecular-weight "rim protein," thereby demonstrating that this protein is distinct from the rod outer segment of Na+/Ca2(+)-exchanger. We used the polyclonal antibody for immunohistochemically localizing the exchange protein in bovine retina. Fluorescent light microscopy revealed intensive immunolabeling of the photoreceptor outer segments, whereas other retinal cell layers exhibited minimal binding. Using the electron microscopic immunogold method, we found specific antibody binding to the extracellular side of rod outer segment plasma membrane. Rod disk membranes, rod inner segments, and cone photoreceptors displayed no significant labeling. We therefore conclude that the Na+/Ca2(+)-exchanger is localized primarily in the rod outer segment plasma membrane, the most appropriate localization considering its proposed role in the process of vertebrate phototransduction.     

Synaptic Connections of Different Strength Between Wind-sensitive Hairs and an Identified Projection Interneuron in the Locust

An identified intersegmental interneuron in Locusta and Schistocerca, with its cell body in the fourth abdominal ganglion and an axon which projects to the brain is excited by mechanosensory inputs from receptors on the head and neck. The organization of its receptive field, the types of sensory receptors which contribute to it and the patterns and strengths of the afferent connections were investigated by intracellular recording from the axon of the interneuron close to a spike-initiating site in the prothoracic ganglion. The receptive field of the interneuron consists of a small patch of hairs on the head ipsilateral to the axon, and from hairs on two regions of the prosternum (a cuticular structure on the ventral surface of the prothoracic segment), first an ipsilateral, lateral region and second a medial but contralateral region. Hairs on the pronotum (dorsal neck) also contribute but were not investigated here. Each spike in the afferent from a hair with a filiform appearance and with a pigmented base on the prosternum consistently evokes an EPSP in the interneuron. These have a short and constant latency, indicating that the connection is probably direct. The head hairs also appear to make direct connections with the interneuron in the prothoracic ganglion, so that the spike-initiating site here can integrate signals evoked by wind on the head and on the prosternum. Stiff tactile hairs on the prosternum do not connect with the interneuron. The EPSPs evoked by the long filiform hairs are consistently larger than those produced by the short filiform hairs and a single spike in some of the afferents from the long filiform hairs can evoke a spike in the interneuron. The effectiveness of an afferent is therefore correlated with the length of the filiform hair it innervates. The hairs with the most powerful effects are always the longest and occur in the same position on every locust. The shape of the receptive field and the different strengths of connections are apparent even in early larval instars. The axonal branches of the interneuron are restricted to the same side of the ganglion as the axon itself. Afferents from filiform hairs on the medial region of the prosternum project contralaterally, and those from the lateral region project ipsilaterally. Afferents from some of the head hairs project ipsilaterally directly to the prothoracic ganglion. The terminals of all these afferents overlap with the branches of the interneuron. By contrast, the afferents of tactile hairs which do not connect, project to different regions of neuropile. The connections ensure that the high sensitivity of the filiform hairs is maintained at the first stage in the central processing and suggest a role for this interneuron in supplying information about small changes in air currents that may be of use in controlling steering manoeuvres during flight.     

A 'puff and advance' technique for visually controlled staining of turtle retinal ganglion cells.

We describe a 'puff and advance' technique for visually controlled staining of retinal ganglion cells (GCs) in the unfixed, living retina for light and electron microscopy. Glass microelectrodes are filled with rhodamine-isothiocyanate labeled horseradish peroxidase (Rh-HRP), or Lucifer yellow (LY), or a mixture of both, or with 5,6-carboxytetramethylrhodamine (5,6-Rh) and advanced tangentially through the GC layer with microscopic observation using epifluorescence. Brief "puffs" of LY or 5,6-Rh are constantly ejected from the advancing electrode tip by a train of negative current pulses. GC penetration is signaled by virtually instantaneous staining of its soma (and eventually its axon and dendrites if the electrode is not advanced further). An impaled GC can be electron densely stained with the Rh-HRP complex by switching to positive current pulses. The extent of dye filling is monitored through the microscope using a filter combination appropriate for the dye. After fixation, standard histochemical procedures reveal HRP stained GCs in wholemount views for light microscopical examination. Furthermore, the preservation of the labeled cells and the neuropil is of a quality to allow electron microscopic analysis for synaptic input. This technique can be used in combination with LY backfiling of GCs from the optic nerve and with retinas in which GCs have been prelabeled with rhodamine beads retrogradely transported from the optic tectum as well.     

The urological spiral. A real alternative to the indwelling catheter? Experience in 23 patients]

Our experiences are reported with the "intraprostatic spiral" in 23 high-risk patients with prostatic adenoma. The intraprostatic spiral was used only in selected patients for medical indications. Patients confined to bed as well as those with detrusor instability or secondary dilatation of the upper urinary tract were excluded. 14 of our patients (60.8%) showed excellent voiding ability, without residual urine and all of them were fully satisfied with the functioning of the prostatic spiral. The longest indwelling time in this group is now about 36 months. 9 of 23 patients (39.2%) were not satisfied with their prostatic spiral. In all of them, the spiral had to be removed later on. Urinary stress incontinence was the main reason for removal. Two thirds of the patients who were not satisfied with the functioning of the prostatic spiral, had a marked decrease in detrusor function. This is a major reason for unsatisfying prostatic spiral function. On average, the prostatic spirals had to be exchanged after 15-18 months because of incrustation. Nearly all patients (21 of 23) showed asymptomatic bacteriuria.