Action of rat liver Galβ1-4GlcNAc α(2-6)-sialyltransferase on Manβ1-4GlcNAcβ-OMe,GalNAcβ1-4GlcNAcβ-OMe,Glcβ1-4GlcNAcβ-OMe and GlcNAcβ1-4GlcNAcβ-OMe as synthetic substrates

Incubation of synthetic Man\1-4GlcNAc-OMe, GalNAc1-4GlcNAc-OMe, Glc1-4GlcNAc-OMe, and GlcNAc1-4GlcNac-OMe with CMP-Neu5Ac and rat liver Gal1-4GlcNAc (2-6)-sialyltransferase resulted in the formation of Neu5Ac2-6Man1-4GlcNAc-OMe, Neu5Ac2-6GalNAc1-4GlcNAc-OMe, Neu5Ac2-6Glc1-4GlcNAc-OMe and Neu5Ac2-6GlcNAc1-4GlcNAc-OMe, respectively. Under conditions which led to quantitative conversion of Gal1-4GlcNAc-OEt into Neu5Ac2-6Gal1-4GlcNAc-OEt, the aforementioned products were obtained in yields of 4%, 48%, 16% and 8%, respectively. HPLC on Partisil 10 SAX was used to isolate the various sialyltrisaccharides, and identification was carried out using 1- and 2-dimensional 500-MHz¹H-NMR spectroscopy.Abbreviations 2D 2-dimensional - CMP cytidine 5-monophosphate - CMP-Neu5Ac cytidine 5-monophospho--N-acetylneuraminic acid - COSY correlation spectroscopy - DQF double quantum filtered - HOHAHA homonuclear Hartmann-Hahn - MLEV composite pulse devised by M. Levitt - Neu5Ac N-acetylneuraminic acid - Neu5Ac2en 2-deoxy-2,3-didehydro-N-acetylneuraminic acid     

Niche breadth explains the range size of European-centred butterflies,but dispersal ability does not

Aim

The breadth of ecological niches and dispersal abilities have long been discussed as important determinants of species' range sizes. However, studies directly comparing the relative effects of both factors are rare, taxonomically biased and revealed inconsistent results.

Location

Europe.

Time Period

Cenozoic.

Major Taxa

Butterflies, Lepidoptera.

Methods

We relate climate, diet and habitat niche breadth and two indicators of dispersal ability, wingspan and a dispersal tendency index, to the global range size of 369 European-centred butterfly species. The relative effects of these five predictors and their variation across the butterfly phylogeny were assessed by means of phylogenetic generalized least squares models and phylogenetically weighted regressions respectively.

Results

Climate niche breadth was the most important single predictor, followed by habitat and diet niche breadth, while dispersal tendency and wingspan showed no relation to species' range size. All predictors together explained 59% of the variation in butterfly range size. However, the effects of each predictor varied considerably across families and genera.

Main Conclusions

Range sizes of European-centred butterflies are strongly correlated with ecological niche breadth but apparently independent of dispersal ability. The magnitude of range size–niche breadth relationships is not stationary across the phylogeny and is often negatively correlated across the different dimensions of the ecological niche. This variation limits the generalizability of range size–trait relationships across broad taxonomic groups.     

Human appropriation of net primary production as driver of change in landscape-scale vertebrate richness

Aim

Land use is the most pervasive driver of biodiversity loss. Predicting its impact on species richness (SR) is often based on indicators of habitat loss. However, the degradation of habitats, especially through land-use intensification, also affects species. Here, we evaluate whether an integrative metric of land-use intensity, the human appropriation of net primary production, is correlated with the decline of SR in used landscapes across the globe.

Location

Global.

Time period

Present.

Major taxa studied

Birds, mammals and amphibians.

Methods

Based on species range maps (spatial resolution: 20 km × 20 km) and an area-of-habitat approach, we calibrated a “species–energy model” by correlating the SR of three groups of vertebrates with net primary production and biogeographical covariables in “wilderness” areas (i.e., those where available energy is assumed to be still at pristine levels). We used this model to project the difference between pristine SR and the SR corresponding to the energy remaining in used landscapes (i.e., SR loss expected owing to human energy extraction outside wilderness areas). We validated the projected species loss by comparison with the realized and impending loss reconstructed from habitat conversion and documented by national Red Lists.

Results

Species–energy models largely explained landscape-scale variation of mapped SR in wilderness areas (adjusted R²-values: 0.79–0.93). Model-based projections of SR loss were lower, on average, than reconstructed and documented ones, but the spatial patterns were correlated significantly, with stronger correlation in mammals (Pearson's r = 0.68) than in amphibians (r = 0.60) and birds (r = 0.57).

Main conclusions

Our results suggest that the human appropriation of net primary production is a useful indicator of heterotrophic species loss in used landscapes, hence we recommend its inclusion in models based on species–area relationships to improve predictions of land-use-driven biodiversity loss.     

Old,socially housed rhesus monkeys manipulate objects

Recent research has indicated that old, individually housed monkeys show little interest in novel objects. Yet unanswered is whether this effect is caused primarily by age or housing condition. The purpose of this study was to assess the role of social living in promoting responsiveness to objects. We measured the rates of object manipulation in older animals, assessed responsiveness over time to particular objects as a measure of habituation, and examined social influences on object use. Several social groups of rhesus monkeys that contained older adults were studied. These groups were housed in indoor pens or in an outdoor enclosure, and all monkeys had continuous access to a variety of objects in their home environment. In contrast to previous studies of individually housed monkeys, our group-housed monkeys showed sustained interest in objects. Old monkeys manipulated objects extensively, and this response was all the more significant, given that the objects were not novel. Monkeys housed in an outdoor enclosure showed object manipulation patterns that were not different from monkeys housed in indoor pens. However, females exhibited much higher object-related responses than males. Social facilitation played a role in the reactions of some monkeys to objects. Patterns of social facilitation as well as avoidance were present in two of the three indoor groups that were observed. Failure to manipulate objects in rhesus macaques appears to be more a function of individual housing than of old age. Factors such as environmental complexity, social needs, and early experience should be considered in order to understand why individually housed rhesus monkeys are unresponsive to objects. © 1993 Wiley-Liss, Inc.     

Comparison of mechanistic and hybrid modeling approaches for characterization of a CHO cultivation process: Requirements,pitfalls and solution paths

Despite the advantages of mathematical bioprocess modeling, successful model implementation already starts with experimental planning and accordingly can fail at this early stage. For this study, two different modeling approaches (mechanistic and hybrid) based on a four-dimensional antibody-producing CHO fed-batch process are compared. Overall, 33 experiments are performed in the fractional factorial four-dimensional design space and separated into four different complex data partitions subsequently used for model comparison and evaluation. The mechanistic model demonstrates the advantage of prior knowledge (i.e., known equations) to get informative value relatively independently of the utilized data partition. The hybrid approach displayes a higher data dependency but simultaneously yielded a higher accuracy on all data partitions. Furthermore, our results demonstrate that independent of the chosen modeling framework, a smart selection of only four initial experiments can already yield a very good representation of a full design space independent of the chosen modeling structure. Academic and industry researchers are recommended to pay more attention to experimental planning to maximize the process understanding obtained from mathematical modeling.     

Electron microscopy of the tracheal ciliated mucosa in rat

Summary The structure of the tracheal epithelial cells from rat has been studied by electron microscopy on approximately 200 Å thick sections with a resolution of better than 30 Å.The epithelium is found to be of a simple columnar type composed of ciliated cells, mucus producing (goblet) cells, basal cells and a fourth kind of cell, here called brush cell. A great number of non-ciliated cells has also been encountered. It has been proved that these represent goblet cells in different stages of intracellular synthesis of mucous granules. The ciliated cells have approximately 8–9 cilia per square micron and there are about 270 cilia on each cell, the calculated surface area being 33 square microns. They are covered by a 70 Å thick membrane. The ciliary filaments are arranged in a pattern of 2 separate ones in the center and a ring of 9 peripheral ones, each divided into 2 subfilaments by a wall with same thickness as the filamentous wall itself, this being 60 Å. The peripheral filaments are continuous with the basal corpuscles. The structure of the corpuscles as compared with earlier findings is discussed. A number of 0.05 micron thick and 1 micron long filiform projections emerge from the cell surface. No cuticle is present.The cell membrane facing adjacent cells is 90 Å and separated from their cell membrane by a 105 Å wide space, this space, being expanded towards a level corresponding to the proximal parts of the cell. A structure that represents terminal bar has been encountered. The cytoplasm is loose and composed of 160 Å thick granules. Spaces enclosed by 50 Å thick membranes with attached 160 Å thick granules (-cytomembranes) are rare. The Golgi zone is analyzed and its regular composition of -cytomembranes, granules and vacuoles is confirmed. The mitochondria with a mean width of 0.23 micron differ to their inner structure from the common type in that the triple layered membranes are highly interconnected. Large opaque granules are encountered in the cytoplasm. Ring-shaped, 850 Å wide, structures are present in the nuclear membrane. The goblet cells are not as abundant as the ciliated cells, the ratio being 14. Small filiform projections covered by a 95 Å thick membrane protrude from the cell surface. This membrane is continuous with the cell membrane, the latter with the same dimensions as in the ciliated cells. Terminal bars are present. The cytoplasm is very opaque due to a dense packing of the 165 Å opaque granules, many in clusters of 4–6. The -cytomembranes have the same dimensions as mentioned above for those present in the ciliated cells. The Golgi zone is of regular composition. There is a suggestion that the Golgi vacuoles and the -cytomembranes are involved in the formation of mucus. In the stage of cellular activity with but few mucous granules, there is a great number of large opaque granules, the size varying from 0.4–1 micron. The mitochondria with a mean width of 0.23 micron have an outer triple layered membrane with a total thickness of 180 Å. The central less opaque layer is 70 Å and the opaque layer on either side is 55 Å. The inner membranes are arranged parallel to each other and have a triple layered composition where the central less opaque layer is 65 Å and the opaque layers each 60 Å. The brush cells belong to the non-ciliated cells. They are encountered singly, surrounded by goblet cells. The surface structures are shaped like brushes or clumsy protrusions which emerge from the distal end of the cell, and are covered by a 95 Å thick membrane. There have been no suggestions of the brushes being cilia in a stage of growth, nor is it probable that they represent stereocilia. They most nearly resemble the intestinal brush border extensions and thus might serve as a resorbing structure.The cytoplasm of the brush cells appears of medium opacity between the ciliated cells and goblet cells and is composed of 155 Å opaque granules. The -cytomembranes are very rare. The Golgi zone is diminutive though of regular composition. The mitochondria are abundant and small with a mean width of 0.14 micron. The outer and inner membranes are triple layered with approximately the same dimensions as reported for the mitochondria of the ciliated and goblet cells. The inner membranes are very few, often only one or two are present. Some of the large opaque granules have inside a very regular arrangement of small 60 Å thick opaque granules arranged in a crystallinic pattern. In the cytoplasm 0.5–1 micron long bundles of 30–40 Å wide fibrils are encountered. The nucleolus shows a characteristic structure of concentrically arranged thin membranes. The basal cells are believed to represent lymphocytes or white blood cells. They sometimes rest on the basement membrane, sometimes are encountered in the distal part of the intercellular spaces. They are bordered by a 110 Å thick cell membrane and have a rather opaque cytoplasm characterized by 160 Å thick opaque granules. A very small Golgi zone is present. The mitochondria, the mean width being 0.14 micron, have triple layered outer and inner membranes, where the less opaque central layer is 65–70 Å and the opaque layers 45–50 Å each. The basement membrane has a thickness of 600 Å. No inner structure has been resolved. The basement membrane is separated from adjacent parts of the ciliated, goblet, brush, and basal cells by a 250 Å wide less opaque space. Below the basement membrane is the lamina propria of the trachea, which is composed of collagen and elastin fibers together with fibroblasts, white blood cells and lymphocytes. The relationship between different types of tracheal epithelial cells in rat has been analyzed. There has been found no indication of a transformation of any type of cells observed into a different type of cell. The development of basal cells via supporting cells or intermediate cells to goblet cells or ciliated cells has not been noticed. On the contrary, all cells that in light microscopy could have been considered to be supporting or intermediate cells, we have been able to recognize as brush cells or as goblet cells to a varying degree filled with mucous granules. If the cells did not seem to reach the cell surface it has been found to be due to a diagonal direction of the sectioning. In this connection it should be emphasized that this relationship is valid only in rat where it is known that the epithelium is of a simple columnar type as distinct from the conditions in man, that epithelium being of a pseudostratified columnar type.This paper is based on a report given at the meeting of Deutsche Gesellschaft für Elektronenmikroskopie in Münster, March 28–31, 1955 and at the Scandinavian Electron Microscope Society Meeting in Stockholm, May 13, 1955.     

Die Aktivitätsperiodik von Nagern im künstlichen 24-Stunden-Tag mit 6–20 Stunden lichtzeit

Zusammenfassung Die Tagesperiodik der lokomotorischen Aktivität von weißen Ratten und Mäusen ist nicht einfach 24-Std-periodisch. Man beobachtet auch im künstlichen Licht-Dunkel-Wechsel 2 Maxima der Aktivität, die den beiden Umkehrpunkten der Umweltperiode: Licht-an und Licht-aus zugeordnet sind. Veränderungen des Verhältnisses von Lichtzeit zu Dunkelzeit (bei unveränderter Dauer der Periode mit 24 Std) führt zu entsprechenden Verformungen der tierischen Periodik: die Maxima folgen mehr oder weniger streng den Verschiebungen der Umkehrpunkte, wie das auch von den jahreszeitlichen Änderungen der Vogelperiodik unter natürlichen Bedingungen bekannt ist.Wird die Zahl der Lichtstunden im 24-Std-Kunsttag von normal 12 Std um 6 Std herauf- oder herabgesetzt, so folgen die Maxima den Umkehrpunkten nicht in gleichem Ausmaß. Bei der Maus beträgt der Abstand zwischen Morgen- und Abendmaximum im Kunsttag mit 12 Std Licht rund 15,5 Std. Im Kunsttag mit 6 oder 18 Std Licht wird dieser Abstand nur um jeweils 1,5 Std verkleinert oder vergrößert. Das gilt auch für Tiere, die bereits 6 Wochen an das entsprechende Licht-Dunkel-Verhältnis angepaßt wurden. Die endogene Komponente der Tagesperiodik läßt Verformungen durch den Zeitgeber nur im begrenzten Umfang zu.Das Verhältnis der Lichtstundenzahl zur Dunkelstundenzahl übt einen starken Einfluß auf die insgesamt vom Tier entwickelte Aktivität aus. Bei schrittweiser Vergrößerung der Lichtstundenzahl von 12 über 14 auf 16 Std/die Licht versuchen dunkelaktive Tiere durch Steigerung der stündlichen Aktivitätsleistung zumal in der Dunkelzeit die Verkürzung der von ihnen bevorzugten Zeitspanne auszugleichen; sie erreichen im allgemeinen im Kunsttag mit rund 14–16 Std/die Licht die größte Gesamtaktivität je 24 Std. Im Kunsttag mit 18 Std Licht und mehr bricht diese Regulation zusammen — die Gesamtaktivität nimmt stark ab. Dasselbe gilt bei Verkürzung der Lichtstundenzahl auf 6: sowohl in der Lichtzeit wie in der Dunkelzeit wird unter diesen Umständen die je Stunde entwickelte Aktivität auf weniger als die Hälfte der Werte herabgedrückt, die für den Kunsttag mit mittlerer Lichtstundenzahl gelten.Die Ergebnisse legen den Schluß nahe, daß je nach Tierart bestimmte Verhältnisse von Licht zu Dunkel eine optimale Umwelt darstellen und daß ganz allgemein nicht nur die Durchschnittswerte der wichtigsten Umweltgrößen sondern auch deren periodische Änderungen entscheidend die Lebensäußerungen der Tierwelt beeinflussen.     

Territorial Behaviour by a Clan of Spotted Hyaenas Crocuta crocuta

Territorial behaviour of a clan of spotted hyaenas, Crocuta crocuta, was investigated in the Kruger National Park over a period of 27 months. These hyaenas were highly territorial, spending ? of their total activities on territory patrol by scent-marking intensively and monitoring 64 marking posts, particularly in border regions. Females, the more philopatric sex, were most active in territory defence. Local intensity of territorial activities by residents within their 130-km² territory was directly proportional to intrusion pressure by neighbours. When clan size was reduced, the ability to defend disputed land declined and larger neighbouring clans appropriated parts of the territory. We propose a relationship between resource distribution, intrusion pressure and territory defence.