Rod Outer Segment Renewal in the Retinae of Deep-sea Fish

AbstractOuter segment renewal involves the synthesis of disc material in the photoreceptor inner segments, the shedding of the tips of the photoreceptor outer segments, and their phagocytosis by the retinal pigment epithelial cells. It has been suggested that in the retinae of deep-sea fish no renewal of outer segments may take place. In order to assess outer segment renewal in deep-sea fish retinae we counted (i) periciliary vesicles in rod inner segments as a parameter for disc-synthesis activity and (ii) phagosomes in retinal pigment epithelial cells as a parameter of shedding and phagocytosis in 12 species of deep-sea fish with multibank or single bank retinae. We also measured the lengths of rod outer segments in order to evaluate the balance between synthesis and phagocytotic activity. In four of these species (Synaphobranchus kaupi, Nematonurus armatus, Coryphaenoides guentheri and Halosauropsis macrochir) we further recorded size-related changes of these parameters and their relation to the position of a given rod within the banks in the retina. The number of periciliary vesicles was highest in inner segments of the most vitread bank and in the periphery of the retina. Phagosomes were most abundant in retinal pigment epithelial cells of the central retina. Long rod outer segments were most frequently recorded in the peripheral retina indicating that in this region new synthesis may outbalance shedding. Vitread rod outer segments were only slightly longer than sclerad ones. Larger animals had shorter rod outer segments than small ones. We present evidence that rod outer segment renewal takes place in the retina of all deep-sea fish. Vitread rods may be more active in this respect than sclerad ones. Copyright © 1996 Elsevier Science Ltd

Zeitgemäß oder anachronistisch? Zwangseinweisungspraxis in Frankfurt am Main

Background: The evaluation of local mental health care remains difficult. For this reason systematic development of appropriate services is barely possible. Methods: We examined involuntary hospitalization in the city of Frankfurt/Main with regard to diagnoses, socio-demographic data, complementary psychosocial outpatient care, and circumstances of hospitalization. There are four psychiatric clinics, each serving a catchment area of more than 165.000 inhabitants. These clinics are responsible for all psychiatric in-patient treatments regardless of the admission modus. During a one year period, 677 patients were involuntarily hospitalized. Statistical analyses were performed subsequent to pooling the data. Results: During a period of one year, 103 out of 100.000 inhabitants of Frankfurt/Main were admitted involuntarily. The rate of involuntary admissions related to all admissions was 10.98 percent. Any complementary psychosocial care was missing in more than 70 percent of patients admitted involuntarily. Only about 10 percent of patients were examined by a physician before reaching the hospital and in disappointing 1.3 percent the municipal mental health service had been consulted prior to involuntarily admission. Conclusion: Our results show that a systematic improvement of precautionary complementary psychosocial care for risk patients is needed as well as the obligation of psychiatric emergency consultation before involuntary hospitalization.Anliegen: In der gemeindepsychiatrischen Versorgung ist eine systematische Datenerhebung bislang unzureichend etabliert. Daher ist eine planvolle Entwicklung von Versorgungsstrukturen kaum möglich. Zur weiteren Qualitätsverbesserung der gemeindepsychiatrischen Struktur soll eine verlässliche Datenbasis geschaffen werden. Methode: Das durch den Sozialpsychiatrischen Dienst initiierte Projekt PISA untersuchte 677 Zwangseinweisungen in die Versorgungskliniken der Stadt Frankfurt/Main. Ergebnisse: Bei über 70 % der Patienten fehlte eine komplementäre psychosoziale Versorgung, nur 10 % wurden außerhalb der Klinik vor der Einweisung ärztlich untersucht, nur 1,3 % durch den Sozialpsychiatrischen Dienst. Schlussfolgerungen: Eine gezielte Ausweitung ambulanter Hilfesysteme und die Hinzuziehung fachärztlicher Kompetenz vor einer Zwangseinweisung erscheinen dringend erforderlich

Involuntary hospitalizations in Frankfurt/Main, Germany

Background: The evaluation of local mental health care remains difficult. For this reason systematic development of appropriate services is barely possible. Methods: We examined involuntary hospitalization in the city of Frankfurt/Main with regard to diagnoses, socio-demographic data, complementary psychosocial outpatient care, and circumstances of hospitalization. There are four psychiatric clinics, each serving a catchment area of more than 165.000 inhabitants. These clinics are responsible for all psychiatric in-patient treatments regardless of the admission modus. During a one year period, 677 patients were involuntarily hospitalized. Statistical analyses were performed subsequent to pooling the data. Results: During a period of one year, 103 out of 100.000 inhabitants of Frankfurt/Main were admitted involuntarily. The rate of involuntary admissions related to all admissions was 10.98 percent. Any complementary psychosocial care was missing in more than 70 percent of patients admitted involuntarily. Only about 10 percent of patients were examined by a physician before reaching the hospital and in disappointing 1.3 percent the municipal mental health service had been consulted prior to involuntarily admission. Conclusion: Our results show that a systematic improvement of precautionary complementary psychosocial care for risk patients is needed as well as the obligation of psychiatric emergency consultation before involuntary hospitalization.Anliegen: In der gemeindepsychiatrischen Versorgung ist eine systematische Datenerhebung bislang unzureichend etabliert. Daher ist eine planvolle Entwicklung von Versorgungsstrukturen kaum möglich. Zur weiteren Qualitätsverbesserung der gemeindepsychiatrischen Struktur soll eine verlässliche Datenbasis geschaffen werden. Methode: Das durch den Sozialpsychiatrischen Dienst initiierte Projekt PISA untersuchte 677 Zwangseinweisungen in die Versorgungskliniken der Stadt Frankfurt/Main. Ergebnisse: Bei über 70 % der Patienten fehlte eine komplementäre psychosoziale Versorgung, nur 10 % wurden außerhalb der Klinik vor der Einweisung ärztlich untersucht, nur 1,3 % durch den Sozialpsychiatrischen Dienst. Schlussfolgerungen: Eine gezielte Ausweitung ambulanter Hilfesysteme und die Hinzuziehung fachärztlicher Kompetenz vor einer Zwangseinweisung erscheinen dringend erforderlich

Model for the Pattern-Dependent Wet Grip Prediction of Tires

The most important task of the tire is to ensure driving safety by optimally transmitting the required longitudinal and lateral driving forces. Although great progress has been made in the past in the development of new materials and patterns, many questions remain unanswered in the field of elastomer friction on rough surfaces. This is particularly true when an additional intermediate medium is introduced into the contact, as for braking on wet roads in the form of water. To better understand this process, a model of a single-tread block on a rough road surface is developed. The influence of the fluid is represented by a physical meaningful friction law. The model is validated with results of tire wet-braking tests on an internal drum test rig. The model can map the interaction between tire tread, rough road surface and fluid film and the simulation results show a good agreement with the measurement results. Based on the investigation of individual tread blocks, a new approach to the description of the wet-braking behavior of passenger car tires was thus demonstrated, which can be extended to more complex tread geometries in the future

Guidelines for Material Design in Semitransparent Organic Solar Cells

Organic solar cells (OSCs) are uniquely suited for semitransparent applications due to their adjustable absorption spectrum. However, most high-performance semitransparent cells reported to date are based on materials that have shown high power conversion efficiency for opaque devices. We therefore present a model to assess the optimum efficiency and transparency for a specific donor and acceptor band gap. The absorption characteristics of both donor and acceptor are modeled with spectral data of typical absorber materials from the literature which are adjusted to achieve the desired band gap value. The results show three distinct regions of high light utilization efficiency if the photopic curve is employed as a weighting function (corresponding to window applications), and a broad maximum for the plant action spectrum as a weighting function (corresponding to greenhouse applications). When comparing these findings to reported experimental values, it is evident that the band gaps of the materials used for the experimental studies do not correspond to the maxima identified by our simulation model. The analysis of the energy levels of molecules recorded in the literature confirms that all band gaps and therefore all LUE maxima are chemically feasible so that the performance of semitransparent OSCs can be further improved by designing materials with optimized absorption spectra.Comment: 20 pages and 10 figure in the main manuscript, aditionally 6 pages and 4 figures in the supporting informatio

A Novel Vertebrate Eye Using Both Refractive and Reflective Optics

SummarySunlight is attenuated rapidly in the ocean, resulting in little visually useful light reaching deeper than ∼1000 m in even the clearest water [1]. To maximize sensitivity to the relatively brighter downwelling sunlight, to view the silhouette of animals above them, and to increase the binocular overlap of their eyes, many mesopelagic animals have developed upward-pointing tubular eyes [2–4]. However, these sacrifice the ability to detect bioluminescent [5] and reflective objects in other directions. Thus, some mesopelagic fish with tubular eyes extend their visual fields laterally and/or ventrally by lensless ocular diverticula, which are thought to provide unfocused images, allowing only simple detection of objects, with little spatial resolution [2–4]. Here, we show that a medial mirror within the ventrally facing ocular diverticulum of the spookfish, Dolichopteryx longipes, consisting of a multilayer stack derived from a retinal tapetum, is used to reflect light onto a lateral retina. The reflective plates are not orientated parallel to the surface of the mirror. Instead, plate angles change progressively around the mirror, and computer modeling indicates that this provides a well-focused image. This is the first report of an ocular image being formed in a vertebrate eye by a mirror

ESTIMATION OF CENTER OF MASS VELOCITY BY RIGHT POSTERIOR SPINE ILIAC LANDMARK DURING COUNTERMOVEMENT JUMP

When the impulse phase is proceeded by approach movement (e.g. volleyball spike jump), the vertical velocity of CoM at the beginning of the impulse phase must be known. To reduce the number of landmarks, the aim of this study was to verify the concordance between the velocity of CoM and the Right Posterior Spine Iliac at touchdown after flight phase. Ten female volleyball players of the first national volleyball league of Austria performed ten maximal CMJ without arm movement. Paired t-test was used to compare velocities between the two methods. No significant differences between the methods with maximal individual differences lower than 0.1m/s at touchdown could be found. If only the landing velocity at touchdown must be known, it seems to be sufficient to determine the velocity of Right Posterior Spine Iliac landmark

spike jump biomechanics in male versus female elite volleyball players

ABSTRACTThere are well-known biological differences between women and men, especially in technical-coordinative variations that contribute to sex differences in performance of complex movements lik..

A taste of the deep-sea: The roles of gustatory and tactile searching behaviour in the grenadier fish <i>Coryphaenoides armatus</i>

The deep-sea grenadier fishes (Coryphaenoides spp.) are among the dominant predators and scavengers in the ocean basins that cover much of Earth's surface. Baited camera experiments were used to study the behaviour of these fishes. Despite the apparent advantages of rapidly consuming food, grenadiers attracted to bait spend a large proportion of their time in prolonged periods of non-feeding activity. Video analysis revealed that fish often adopted a head-down swimming attitude (mean of 21.3 degrees between the fish and seafloor), with swimming velocity negatively related to attitude. The fish also swam around and along vertical and horizontal structures of the lander with their head immediately adjacent to the structure. We initially hypothesised that this behaviour was associated with the use of the short chin barbel in foraging. Barbel histology showed numerous taste buds in the skin, and a barbel nerve with about 20,000 axons in adult fish. A tracing experiment in one undamaged animal revealed the termination fields of the barbel neurons in the trigeminal and rhombencephalic regions, indicating both a mechanoreceptory and a gustatory role for the barbel. Our conclusion was that olfactory foraging becomes ineffective at close ranges and is followed by a search phase using tactile and gustatory sensing by the barbel. The development of this sensory method probably co-evolved alongside behavioural changes in swimming mechanics to allow postural stability at low swimming speeds

Nanosized Multifunctional Polyplexes for Receptor-Mediated SiRNA Delivery

Although our understanding of RNAi and our knowledge on designing and synthesizing active and safe siRNAs significantly increased during the past decade, targeted delivery remains the major limitation in the development of siRNA therapeutics. On one hand, practical considerations dictate robust chemistry reproducibly providing precise carrier molecules. On the other hand, the multistep delivery process requires dynamic multifunctional carriers of substantial complexity. We present a monodisperse and multifunctional carrier system, synthesized by solid phase supported chemistry, for siRNA delivery in vitro and in vivo. The sequence-defined assembly includes a precise cationic (oligoethanamino)amide core, terminated at the ends by two cysteines for bioreversible polyplex stabilization, at a defined central position attached to a monodisperse polyethylene glycol chain coupled to a terminal folic acid as cell targeting ligand. Complexation with an endosomolytic influenza peptide-siRNA conjugate results in nanosized functional polyplexes of 6 nm hydrodynamic diameter. The necessity of each functional substructure of the carrier system for a specific and efficient gene silencing was confirmed. The nanosized polyplexes showed stability in vivo, receptor-specific cell targeting, and silencing of the EG5 gene in receptor-positive tumors. The nanosized appearance of these particles can be precisely controlled by the oligomer design (from 5.8 to 8.8 nm diameter). A complete surface charge shielding together with the high stability result in good tolerability in vivo and the absence of accumulation in nontargeted tissues such as liver, lung, or spleen. Due to their small size, siRNA polyplexes are efficiently cleared by the kidney