Ultrastructure of the type “B” cells in the rectal pad epithelium of Locusta migratoria

The electron microscopical structure of the type “B” cells in the rectal pad epithelium of Locusta is described. The type “B” cells occur singly in the distal region of the rectal pad epithelium. They are characteristically goblet shaped and join with contiguous type “A” or rectal pad cells, near the apical surface by means of a restricted region of septate desmosomes. Type “B” cells possess a microvillate apical membrane, with the villi arranged as a rosette overlying the apical inaginations of adjacent type “A” cells. Large numbers of microtubules and vacuoles of various sizes containing an assortment of inclusions are present in the apical region of the type “B” cells. Many of the microtubules insert distally on hemidesmosomes located in the apical plasma membrane. Rough endoplasmic reticulum and mitochondria are also present but neither are abundant. The possible significance of these findings is discussed.     

Electron-Microscopic Demonstration of a “Head and Stalk” Structure of the Leaf Vacuolar ATPase in Mesembryanthemum crystallinum L.

The structure of the vacuolar ATPase from mesophyll tonoplasts of Mesembryanthemum crystallinum has been studied by electron microscopy using negatively stained specimens of membrane-bound and detergent-solubilized ATPase molecules. We observed a high density of particles on the surface of tonoplast vesicles and “head and stalk” structures on the edge of the membrane, similar to the F₀F₁-ATPases of mitochondrial and chloroplast membranes. The staining conditions, which are often critical for such small objects, were improved by using methylamine tungstate as negative stain for the membrane-bound ATPase. Compared to other staining solutions generally applied, dissociation of the F₁-like enzyme complex from the membrane was best prevented and structural damage of the vesicles was least observed with methylamine tungstate. In freeze-fracture electron microscopy of tonoplast vesicles, where dissociation never occurs since no detergent is used, we also observed “head and stalk” structures on the edge of the membranes, beside many particles on the fracture faces. The detergent-solubilized ATPase forms string-like structures, caused by the aggregation of the hydrophobic membrane-embedded F₀-like part of the enzyme. After negative staining the F₁-like enzyme complex is arranged alternately along both sides of the string and connected by a narrow stalk.     

Rearing method for the sporophagous thrips Bactrothrips brevitubus (Thysanoptera: Phlaeothripidae: Idolothripinae)

Mycophagous and particularly sporophagous thrips are difficult to rear under laboratory conditions, and this has been a major constraint in studying the life histories of such thrips in any detail. We developed a rearing method for Bactrothrips brevitubus, a sporophagous Japanese thrips, that can be modified readily to rear other sporophagous species. This method can maintain all developmental stages of the thrips by controlling humidity, temperature and fungal spore density. The method enables rearing over multiple generations, thereby facilitating investigations of the relationship between environmental conditions (e.g. food quantity) and breeding system (e.g. reproductive mode and offspring sex ratio).     

Ultrastructural changes associated with UV irradiation in the "germinal plasm" of Xenopus laevis

To detect structural changes following UV irradiation in the “germinal plasm,” ultrastructure of the “germinal plasm” was studied in normal and UV-irradiated eggs of Xenopus laevis at the following stages: prior to fertilization, early 2-cell, 32-cell, and late blastula. It was revealed that ultrastructural features of the “germinal plasm” were essentially common between Xenopus laevis and Rana pipiens. That is, the “germinal plasm” is composed primarily of a large aggregation of mitochondria and distinctive electron dense bodies (germinal granules). Irregularly shaped cylinderlike granules (giant germinal granules), having the same internal characteristics as the germinal granules, were found in the “germinal plasm” of all eggs examined.Comparison between normal and UV-irradiated eggs has demonstrated that UV irradiation causes swelling and vacuolation of mitochondria and fragmentation of germinal granules. The suggestion is that the integrity of certain UV-sensitive factor(s), which is involved in maintaining normal structure of germinal granules, is indispensable for the determination of the primordial germ cells.     

Ape-like endocast of “ape-man” Taung

I have identified and illustrated a spherical “dimple” or “depression” on the Taung endocast as indicating the most likely position of the medial end of the lunate sulcus but have not drawn an actual lunate sulcus on Taung because one is not visible. In a recent paper, R.L. Holloway (Am. J. Phys. Anthropol. 77:27–33, 1988) drew a lunate sulcus on his copy of the Taung endocast, incorrectly attributed this sulcus to me, and used it to obtain a ratio of 0.254 to describe “Falk's” position of the lunate sulcus. My published ratio of 0.242 for Taung (Falk: Am. J. Phys. Anthropol. 67:313–315, 1985a) was not considered, although the focus of Holloway's paper was my assessment of the position of the lunate sulcus. Holloway also excluded published ratios for a chimpanzee in my collection from his statistical analysis but, even so, my published ratio for Taung is still only 1.5 standard deviations from his chimpanzee mean. If my chimpanzee brain is included in the sample, the ratio for Taung is 1.2 standard deviations from the mean. Furthermore, one of Holloway's own chimpanzees (B60–7) has a ratio of 0.241, just 0.001 below my ratio for Taung. There is no sulcus where Holloway has drawn one on Taung, his “F(LS)” is not mine, his 2 mm error is not mine, and the correct ratio for my measurement of Tuang is the one that I published, not the one that Holloway attributes to me. Assessment of Holloway's chimpanzee data supports my claim that the dimple on the Taung endocast is within the chimpanzee range for the medial end of the lunate sulcus.     

Petite bodies of the “robust” australopithecines

The “robust” australopithecines are often depicted as having large and powerfully built bodies to match their massive masticatory apparatus, but until 1988 the sample of postcranial remains attributed with certainty to this group was very limited. Almost nothing was known about the body of the East African “robust” australopithecine because taxonomic attribution of the postcrania was so uncertain. The body of the South African “robust” australopithecine had to be reconstructed from about a dozen isolated fragments of postcrania. Now a partial skeleton is attributed with confidence to the East African “robust” group along with several isolated bones. The South African sample has more than tripled. Analyses of this vastly expanded sample reveal that a large portion of postcrania attributed to “robust” australopithecines from Swartkrans Member 1 (35%) are from extraordinarily small-bodied individuals similar in size to a modern Pygmy weighing as little as 28 kg. These small elements include parts from the forelimb, spine, and hindlimb. About 22% of these Swartkrans 1 “robust” australopithecines are about the same size as a modern human weighing about 43 kgs and about 43% are larger than this standard but less than or equal to a 54 kg modern human. Approximately the same pattern is true for the Swartkrans 2 hominids, but taxonomic attribution is less certain. All of the Member 3 specimens are similar in size to the 45 kg standard. The partial skeleton of the East African “robust” australopithecine (KNM-ER 1500) has hindlimb joints that would correspond to a modern human of 34 kgs although the actual weight may be 5 to 10 kgs greater judging from shaft robusticity and forelimb size. The largest postcranial element attributed with some certainty to the East African “robust” australopithecine group (the talus, KNM-ER 1464) is about the same overall size as a modern human of 54 kgs, although its tibial facet is slightly smaller. Although many previous studies have hinted at the possibility that “robust” australopithecines had relatively small bodies, the new fossils provide substantial evidence that these creatures ranged from quite small to only moderate in body size relative to modern humans. These were the petite-bodied vegetarian cousins of our ancestors. Sexual dimorphism in body size appears to be greater than that in modern humans, similar to that in Pan, and less than that in Gorilla or Pongo, although such comparisons are of limited value given the small samples, poorly known body proportions, time averaging, and many other problems.     

Dietary Restraint and Control Over “Wanting” Following Consumption of “Forbidden” Food

Eating behavior can be influenced by the rewarding value of food, i.e., “liking” and “wanting.” The objective of this study was to assess in normal‐weight dietary restrained (NR) vs. unrestrained (NU) eaters how rewarding value of food is affected by satiety, and by eating a nonhealthy perceived, dessert‐specific food vs. a healthy perceived, neutral food (chocolate mousse vs. cottage cheese). Subjects (24NR age = 25.0 ± 8.2 years, BMI = 22.3 ± 2.1 kg/m²; 26NU age = 24.8 ± 8.0 years, BMI = 22.1 ± 1.7 kg/m²) came to the university twice, fasted (randomized crossover design). Per test‐session “liking” and “wanting” for 72 items divided in six categories (bread, filling, drinks, dessert, sweets, stationery (placebo)) was measured, before and after consumption of chocolate mousse/cottage cheese, matched for energy content (5.6 kJ/g) and individual daily energy requirements (10%). Chocolate mousse was liked more than cottage cheese (P < 0.05). After consumption of chocolate mousse or cottage cheese, appetite and “liking” vs. placebo were decreased in NR and NU (P < 0.03), whereas “wanting” was only decreased in NR vs. NU (P ≤ 0.01). In NR vs. NU “wanting” was specifically decreased after chocolate mousse vs. cottage cheese; this decrease concerned especially “wanting” for bread and filling (P < 0.05). To conclude, despite similar decreases in appetite and “liking” after a meal in NR and NU, NR decrease “wanting” in contrast to NU. NR decrease “wanting” specifically for a nonhealthy perceived, “delicious,” dessert‐specific food vs. a nutritional identical, yet healthy perceived, slightly less “delicious,” “neutral” food. A healthy perceived food may thus impose greater risk for control of energy intake in NR.     

Integration of “Innate” and “Learned” Components within the IRME for Mussel Recognition in the European Bitterling Rhodeus amarus (Bloch)

The European bitterling (Rhodeus amarus Bloch) practises a rather unusual method of spawning by using the favorable conditions in the gills of a living freshwater mussel (genera Unio and Anodonta) for the embryonic development of its fry. The capacity of mussel recognition was studied in inexperienced individuals with the aid of simultaneous preference tests in which pairs of dummies with increasing similarity to mussels were presented to the animals. The frequency of mussel-referred motor patterns, which were supposed to be species-specific (Wiepkema 1961), supplied the evaluation criterion. The results revealed a hierarchy of effectiveness within the class of relevant stimuli and showed certain effects of additivity typical of an Innate Releasing Mechanism or IRM. By far the most effective stimulus consisted in the specific smell of the mussel which is composed of at least three constituents (protein, hyaluronic acid, ammonium). The water flow itself, produced by the mussel in order to maintain nutritive and respiratory functions, was effective depending on its velocity (3 < v < 12 cm/s), its orientation (suction produced no effect), its direction (vertical > horizontal) and the shape of its field (oval). Within the visual modality only two simple perceptory patterns could be detected (dark spot on a clearer surface, straight horizontal edge), but the visual shape of the mussel as a whole was ignored by inexperienced individuals. Nevertheless the bitterlings are able to learn the shape when exposed to a living mussel and, in addition, it was even possible to condition the animals to an artificial object (inverted pot of clay) by using the mussel-smell flow as a reinforcing stimulus. The final discussion deals with the question of whether it is possible to interpret these “innate” respectively “learned” components of the IRME as sensory counterparts of behavioral structures which simply serve different functions by referring to correspondingly different sectors of the environment. In such a case the epistemological dichotomy regularly associated with the notions of “innate” (= “pre-given phylogenetical knowledge”) and “learned” (= “cognitive increase during ontogeny”) would suffer incisive questioning.     

“Reverse” sexual dichromatism in a Neotropical frog

Sexual dichromatism is widespread among animals, but examples of “reverse” sexual dichromatism, in which females are more brightly colored than males, are extremely rare. We discovered a unique case of reverse sexual dichromatism in the golden rocket frog (Anomaloglossus beebei), a diurnal Neotropical frog. Females are bright “golden” in color, and males are drab tan with brown pigmentation that darkens when they are calling. Here, we document this color variation with calibrated digital photography and further show that there is no evidence for sex‐specific habitat matching; both sexes live in the same well‐lit habitat on green bromeliad leaves. Our results suggest that color variation in this species is an intraspecific signal and provide an important exception to the general expectation that males are more visually conspicuous in species with conventional sex roles.     

“Stepping-sticks” and “seat-sticks”: New types of tools used by wild chimpanzees (Pan troglodytes) in Sierra Leone

In Tenkere, Sierra Leone, a community of wild chimpanzees (Pan troglodytes verus) spent long hours eating the fruits and flowers of the Kapok (Ceiba pentandra) tree. The branches of this species are covered in sharp thorns which make movement in their high canopies problematic for the chimpanzees. In an apparent attempt to increase their mobility and to ease the discomfort of lengthy bouts of eating in these trees, some of the Tenkere chimpanzees have been observed using stick tools as foot (“stepping-sticks”) and body (“seat-sticks”) protection against the painful thorns. This form of tool-using is culturally unique to the Tenkere chimpanzees, as at other sites where these apes have been observed eating parts of kapok trees, there are no published records of this tool technology. In three of the stepping-stick tool use incidents, the chimpanzee used the tool(s), held between their greater and lesser toes, in locomotion. This form of tool use is the first recorded case of habitually used tools that can be justifiably categorized as being “worn” by any known wild population of Pan troglodytes. Am J Primatol 41:45–52, 1997. © 1997 Wiley-Liss, Inc.     

Formation and function of the “Xestoleberis‐spot” in Xestoleberis hanaii (Crustacea: Ostracoda)

The crescent sculpture of the so‐called “Xestoleberis‐spot” develops inside the calcified valve of the family Xestoleberididae. Electron microscopic observations on both, intermoult and postmoult stages of Xestoleberis species reveal that the “Xestoleberis‐spot” system consists of three elements; two calcified chambers, a vesicle of electron‐dense material and an uncalcified procuticle. The formation and function of the “Xestoleberis‐spot” system are discussed. In conclusion, the “Xestoleberis‐spot” system functions as the muscle attachment site for several antennal muscles, and provides the material for chitinous fibers in the exocuticle of outer lamella. The unique cuticular structures of the family Xestoleberididae are due to the “Xestoleberis‐spot” system.     

THE ULTRASTRUCTURE OF SCENEDESMUS (CHLOROPHYCEAE). I. SPECIES WITH THE “RETICULATE” OR “WARTY” TYPE OF ORNAMENTAL LAYER1

The ultrastructure of the wall layers and ornamentative features of Scenedesmus pannonicus and S. longus are described using carefully correlated freeze-etched replicas, thin sections and scanning electron micrographs. The two species arc enclosed by different types of ornamented layers, S. pannonicus by the tightly filling, “warty” layer and S. longus by the loosely fitting, “reticulate” layer, held off the coenobium by 2 types of tubular propping spikelets and rosettes. The reticulate layer has an intricate substructure, especially when studied with freeze-etching. Its inner and outer surfaces appear different, as is its attachment to the 2 types of spikelets. Whole cells of S. longus subjected to acetolysis lack the cellulose wall and cytoplasm, but all other surface features survive, including the Trilaminar Sheath (TLS); this ornamentation cannot be “pectic.” The cellulose wall and ornamentation is unaffected by boiling water alone. Boiling in 6n NaOH removes the surface ornamentation, but the TLS and wall remain; the possibility that these features contain silica is discussed. The terminal spines of both species consist of closely packed spikelets enclosed within a skin of hexagonally-packed subunits. Similar subunits are seen in the propping spikelets of S. longus, and in the rows or “combs” of laterally fused spikelets of S. pannonicus. The warty layer of S. pannonicus is tightly appressed to the TLS except close to where the cells are joined, where it is suspended free. It is composed of a layer of globular subunits, and small indentations form the warts. Single, evenly distributed warts characterize the freely suspended sections of the warty layer, and the layer that encloses young coenobia soon after they have been formed: in contrast, the warts are clumped over the surface of older and larger colonies. Some of the single warts form characteristic double rows, but these latter remain single even on older cells. The surface structure of the warty layer, TLS, and plasmalemma are revealed by the freeze-etching process.     

Relationship between Mycobacterium nonchromogenicum,Mycobacterium terrae,Mycobacterium novum and Subgroup “V” (Mycobacterium trivial)

Comparison was made among Mycobacterium nonchromogenicum, M. terrae, M. novum and subgroup “V” (M. trivial) These organisms together are differentiated from other mycobacteria of group II and group III by the following characters: (1) Sensitiveness to ethambutol; (2) Tolerance to nitrite; (3) Tolerance to Tween 80; (4) Inability to utilize glucose and succinate in the presence of glutamate. To exclude the influence of growth rate, rough colony mutants (R-type mutants) were isolated from M. nonchromogenicum, M. terrae and M. novum and compared with each other and subgroup “V” that was originally of R-type. The R-type mutants of M. nonchromogenicum were similar to those of M. terrae, with the exception of the intensity of nicotinamidase and pyrazinamidase activities. These two have been suggested to belong to the same taxon, appropriate name of which is M. nonchromogenicum. The R-type mutants of M. novum were similar to the subgroup “V”, with the exception of the intensity of arylsulfatase activity. It has been considered that subgroup “V” is an R-type mutant of M. novum. Although M. nonchromogenicum and M. novum could be differentiated from each other by the intensity of the arylsulfatase, nicotinamidase and pyrazinamidase activities and requirement of nitrogen compounds, these two organisms are differentiated from other mycobacteria by the same characteristics and are therefore considered to be closely related organisms.     

Comparative ultrastructure of Langerhans‐like cells in spleens of ray‐finned fishes (Actinopterygii)

We studied the morphology and occurrence of splenic Langerhans‐like (LL) cells in species representing 11 orders of ray‐finned fishes, Actinopterygii. LL cells were frequent in spleen tissue of species among Cypriniformes, Esociformes, Salmoniformes, and Pleuronectiformes. These cells contained granules which resembled Birbeck granules known to occur in mammalian Langerhans cells. The ultrastructure of LL cells in Northern pike, Esox lucius, and in Atlantic halibut, Hippoglossus hippoglossus were similar to those reported in salmonids. LL cells found in cyprinids shared some characteristics with the LL cells in other Actinopterygii species, although unique structures distinguished them from the latter. They contained dense bodies within the Birbeck‐like (BL) granules, a characteristic that was never observed in species outside the Cypriniformes. Two types of BL granules were characterized in cyprinid LL cells. The ultrastructure of BL granules across the species is discussed. LL cells in all Actinopterygii species demonstrated close contacts with nearby cells, characterized by adherens‐like junctions. Additionally, multivesicular bodies were present within the cytoplasm and large aggregates of exosomes were observed closely associated with the plasma membrane suggesting their release from the cells. These structures are discussed in relation to mammalian dendritic cells. Macrophages found in European perch, Perca fluviatilis, blue gourami, Trichogaster trichopterus, and Atlantic halibut, Hippoglossus hippoglossus contained lysosomes and residual bodies with structures resembling Birbeck granules. These granules and cells were clearly distinct from LL cells. J. Morphol. 2010. © 2010 Wiley‐Liss, Inc.     

An “orientation sphere” visualization for examining animal head movements

1. Animal behavior is elicited, in part, in response to external conditions, but understanding how animals perceive the environment and make the decisions that bring about these behavioral responses is challenging.
2. Animal heads often move during specific behaviors and, additionally, typically have sensory systems (notably vision, smell, and hearing) sampling in defined arcs (normally to the front of their heads). As such, head‐mounted electronic sensors consisting of accelerometers and magnetometers, which can be used to determine the movement and directionality of animal heads (where head “movement” is defined here as changes in heading [azimuth] and/or pitch [elevation angle]), can potentially provide information both on behaviors in general and also clarify which parts of the environment the animals might be prioritizing (“environmental framing”).
3. We propose a new approach to visualize the data of such head‐mounted tags that combines the instantaneous outputs of head heading and pitch in a single intuitive spherical plot. This sphere has magnetic heading denoted by “longitude” position and head pitch by “latitude” on this “orientation sphere” (O‐sphere).
4. We construct the O‐sphere for the head rotations of a number of vertebrates with contrasting body shape and ecology (oryx, sheep, tortoises, and turtles), illustrating various behaviors, including foraging, walking, and environmental scanning. We also propose correcting head orientations for body orientations to highlight specific heading‐independent head rotation, and propose the derivation of O‐sphere‐metrics, such as angular speed across the sphere. This should help identify the functions of various head behaviors.
5. Visualizations of the O‐sphere provide an intuitive representation of animal behavior manifest via head orientation and rotation. This has ramifications for quantifying and understanding behaviors ranging from navigation through vigilance to feeding and, when used in tandem with body movement, should provide an important link between perception of the environment and response to it in free‐ranging animals.

     

Extended “Adsorption–Insertion” Model: A New Insight into the Sodium Storage Mechanism of Hard Carbons

Hard carbons (HCs) are promising anodes of sodium‐ion batteries (SIBs) due to their high capacity, abundance, and low cost. However, the sodium storage mechanism of HCs remains unclear with no consensus in the literature. Here, based on the correlation between the microstructure and Na storage behavior of HCs synthesized over a wide pyrolysis temperature range of 600–2500 °C, an extended “adsorption–insertion” sodium storage mechanism is proposed. The microstructure of HCs can be divided into three types with different sodium storage mechanisms. The highly disordered carbon, with d₀₀₂ (above 0.40 nm) large enough for sodium ions to freely transfer in, has a “pseudo‐adsorption” sodium storage mechanism, contributing to sloping capacity above 0.1 V, together with other conventional “defects” (pores, edges, heteroatoms, etc.). The pseudo‐graphitic carbon (d‐spacing in 0.36–0.40 nm) contributes to the low‐potential (<0.1 V) plateau capacity through “interlayer insertion” mechanism, with a theoretical capacity of 279 mAh g^?1 for NaC₈ formation. The graphite‐like carbon with d₀₀₂ below 0.36 nm is inaccessible for sodium ion insertion. The extended “adsorption–insertion” model can accurately explain the dependence of the sodium storage behavior of HCs with different microstructures on the pyrolysis temperature and provides new insight into the design of HC anodes for SIBs.     

Teilhard de Chardin,human evolution and “Piltdown Man”

Pierre Teilhard de Chardin was a French Jesuit paleontologist, priest, and philosopher. In the figures published in articles in 1943 and 1951, he attempted to draw a “plausible schematic reconstruction of the natural connections between fossil men” and a “phyletic composition of the human group”. I draw attention to Teilhard's reference to Eoanthropus (“Piltdown Man”) in small print in his figure that was first printed in 1943. Most suspiciously, there is no reference to this (supposedly important) genus in the associated text, nor is there any reference whatsoever to “Piltdown Man” in the article published in 1951. Even as early as January 1913, Teilhard may have been aware that “Piltdown Man” was a hoax or joke, artificially associating a human cranium with a modified orangutan mandible. A new suspect is Edgar Willett (rather than Charles Dawson). Teilhard may have been an advisory accomplice in a joke that went seriously wrong.     

On the “filterable aggregates and other particles” interpretation of the extraordinary regime of polyelectrolytes

Quasi-elastic light scattering studies on some polyelectrolyte systems exhibit a somewhat “bizarre” behavior in the profile of the apparent diffusion coefficient D_app as a function of the salt concentration C_s. As C_s is decreased, D_app first increases in accordance with polyelectrolyte theories, and then undergoes a precipitous drop in value by over an order of magnitude at a well-defined critical value C_s = C. This “transition” from C_s > C (ordinary) to C_s < C (extraordinary) is referred to as the “ordinary-extraordinary” (o-e) transition. Ghosh, Peitzsch, and Reed [(1992) Biopolymers, Vol. 32, pp. 1105–1122] proposed a “filterable aggregate” (FA) and “other particle” interpretation for the o-e transition and its reversibility in regard to ionic strength changes. The present communication examines in detail the FA model as applied to the o-e transition. It is shown that the FA model fails to account of the established characteristics of the o-e transition. © 1993 John Wiley & Sons, Inc.     

Fine structure of the dorsal bristle complex and pellicle of Euplotes

The fine structure of the dorsal bristle complex and pellicle of non-developing Euplotes eurystomus is described in detail by scanning and transmission electron microscopy. The bristle-pit unit is a highly differentiated complex of organelles. The bristle complex is composed of a pair of kinetosomes (basal bodies) joined by a connective. The anterior kinetosome bears the bristle cilium, which contains a polarized network of particles (“lasiosomes”). The posterior kinetosome bears a very short, knob-like “condylocilium,” and has an associated striated fiber. Accessory ribbons of microtubules are also associated with the kinetosome couplets. Parasomal sacs, a septum connecting the bristle cilium to the anterior wall of the pit, core granules of the kinetosomes, and large membranous ampules are described. The organization of the bristle complex bears many similarities to the somatic ciliature of other ciliates. The pellicle of Euplotes is composed of a continucus outer cell membrane subtended by membranous alveoli, which contain a “fibrous mat.” Two sheets of subpellicular microtubules (longitudinal and transverse) are located just beneath the alveoli. The “epiplasm” seen in some other ciliates is apparently absent in Euplotes. The texture of the cell surface is a pattern of folds or rugae composed of the outer cell membrane and the upper membrane of the alveolus. The pattern of rugae probably defines the “silverline-system” of light microscopy.