Polynucleotide sequence relatedness among motileAeromonas species

Relatedness among 55 motileAeromonas strains was assessed by determining the extent of reassociation in heterologous DNA preparations. S1 nuclease and diethylaminoethyl-cellulose filters were used to separate reassociated nucleotide sequences from nonreassociated sequences and to determine the thermal stability of related nucleotide sequences. The motile aeromonads would presently consist of three species:A. hydrophila (type strain ATCC 7966),A. caviae (type strain ATCC 15468), andA. sobria (type strain CIP 7433). These three species are clearly separated on the basis of both biochemical characteristics and similarities in DNA. Each of these three species contains more than one hybridization group: three groups inA. hydrophila; two groups inA. caviae; and at least two groups inA. sobria. DNA hybridization groups are biochemically similar within each species. When additional data is available, these separate DNA hybridization groups may merit designation. Any decision to delineate species in terms of DNA hybridization groups must await a phenotypic basis for their separation.     

Comparative morphometrics of the primate apical tuft

The relationship between the structure and function of the primate apical tuft is poorly understood. This study addresses several hypotheses about apical tuft morphology using a large modern primate comparative sample. Two indices of tuft size are employed: expansion and robusticity. First, comparisons of relative apical tuft size were drawn among extant nonhuman primate groups in terms of locomotion and phylogenetic category. Both of these factors appear to play a role in apical tuft size among nonhuman primates. Suspensory primates and all platyrrhines had the smallest apical tufts, while terrestrial quadrupeds and all strepsirrhines (regardless of locomotor category) had the largest tufts. Similarly, hypotheses regarding the apical tufts of hominins, especially the large tufts of Neandertals were addressed using a comparison of modern warm- and cold-adapted humans. The results showed that cold-adapted populations possessed smaller apical tufts than did warm-adapted groups. Therefore, the cold-adaptation hypothesis for Neandertal distal phalangeal morphology is not supported. Also, early modern and Early Upper Paleolithic humans had apical tufts that were significantly less expanded and less robust than those of Neandertals. The hypothesis that a large apical tuft serves as support for an expanded digital pulp is supported by radiographic analysis of modern humans in that a significant correlation was discovered between the width of the apical tuft and the width of the pulp. The implications of these findings for hypotheses about the association of apical tuft size and tool making in the hominin fossil record are discussed.     

Body size and scaling of the hands and feet of prosimian primates

The hands and feet of primates fulfill a variety of biological roles linked with food acquisition and positional behavior. Current explanations of shape differences in cheiridial morphology among prosimians are closely tied to body size differences. Although numerous studies have examined the relationships between body mass and limb morphology in prosimians, no scaling analysis has specifically considered hand and foot dimensions and intrinsic proportions. In this study, we present such an analysis for a sample of 270 skeletal specimens distributed over eight prosimian families. The degree of association between size and shape was assessed using nonparametric correlational techniques, while the relationship between each ray element length and body mass (from published data and a body mass surrogate) was tested for allometric scaling. Since tarsiers and strepsirrhines encompass many taxa of varying degrees of phylogenetic relatedness, effective degrees of freedom were calculated, and comparisons between families were performed to partially address the problem of statistical nonindependence and "phylogenetic inertia." Correlational analyses indicate negative allometry between relative phalangeal length (as reflected by phalangeal indices) and body mass, except for the pollex and hallux. Thus, as size increases, there is a significant decrease in the relative length of the digits when considering all prosimian taxa sampled. Regression analyses show that while the digital portion of the rays scales isometrically with body mass, the palmar/plantar portion of the rays often scales with positive allometry. Some but not all of these broadly interspecific allometric patterns remain statistically significant when effective degrees of freedom are taken into account. As is often the case in interspecific scaling, comparisons within families show different scaling trends in the cheiridia than those seen across families (i.e., lorisids, indriids, and lemurids exhibit rather different allometries). The interspecific pattern of positive allometry that appears to best characterize the metapodials of prosimians, especially those of the foot, parallels differences found in the morphology of the volar skin. Indeed, relatively longer metapodials appear to covary with flatter and more coalesced volar pads, which in turn slightly improve frictional force for animals that are at a comparative disadvantage while climbing because of their larger mass. Despite the essentially isometric relationship found between digit length and body mass across prosimians, examination of the residual variation reveals that tarsiers and Daubentonia possess, relative to their body sizes, remarkably long fingers. Such marked departures between body size and finger length observed in these particular primates are closely linked with specialized modes of prey acquisition and manipulation involving the hands.     

Support polygons and symmetricalgaits in mammals

The symmetrical gaits of quadrupedal mammals are oftendescribed in terms of two variables: duty factor (S = the stanceperiod of one foot, as a percentage of the gait cycle) and diagonality(D = the percentage of the cycle period by whichthe left hind footfall precedes the left fore footfall). We showthat support polygons are optimized during walking (i.e.the percentage of the locomotor cycle spent standing on only twofeet is minimized) for: (1) the diagonal-sequence, diagonal-coupletswalks characteristic of primates (50 < D < 75)when D = [hindlimb S]; (2) lateral-sequence,lateral-couplets walks (0 < D < 25)when D = [hindlimb S]− 50;(3) lateral-sequence, diagonal-couplets walks (25 < D < 50)when D = 100 −[forelimb S].To determine whether animal behaviour is optimal in this sense,we examined 346 symmetrical gait cycles in 45 mammal species. Ourempirical data show that mammalian locomotor behaviour approximatesthe theoretical optima. We suggest that diagonal-sequence walkingmay be adopted by ­primates as a means of ensuring thata grasping hindfoot is placed in a protracted position on a testedsupport at the moment when the contralateral forefoot strikes downon an untested support.  © 2002 The Linnean Societyof London, Zoological Journal of the Linnean Society , 2002, 136 ,401−420     

The hands and feet of Archaeolemur: metrical affinities and their functional significance

Recent expeditions to Madagascar have recovered abundant skeletal remains of Archaeolemur, one of the so-called "monkey lemurs" known from Holocene deposits scattered across the island. These new skeletons are sufficiently complete to permit reassembly of entire hands and feet--postcranial elements crucial to drawing inferences about substrate preferences and positional behavior. Univariate and multivariate analysis of intrinsic hand and foot proportions, phalangeal indices, relative pollex and hallux lengths, phalangeal curvature, and distal phalangeal shape reveal a highly derived and unique morphology for an extinct strepsirrhine that diverges dramatically from that of living lemurs and converges in some respects on that of Old World monkeys (e.g., mandrills, but not baboons or geladas). The hands and feet of Archaeolemur are relatively short (extremely so relative to body size); the carpus and tarsus are both "long" relative to total hand and foot lengths, respectively; phalangeal indices of both the hands and feet are low; both pollex and hallux are reduced; the apical tufts of the distal phalanges are very broad; and the proximal phalanges are slightly curved (but more so than in baboons). Overall grasping capabilities may have been compromised to some extent, and dexterous handling of small objects seems improbable. Deliberate and noncursorial quadrupedalism was most likely practiced on both the ground and in the trees. A flexible locomotor repertoire in conjunction with a eurytopic trophic adaptation allowed Archaeolemur to inhabit much of Madagascar and may explain why it was one of the latest surviving subfossil lemurs.     

Role of the prehensile tail during ateline locomotion: experimental and osteological evidence

The dynamic role of the prehensile tail of atelines during locomotion is poorly understood. While some have viewed the tail of Ateles simply as a safety mechanism, others have suggested that the prehensile tail plays an active role by adjusting pendulum length or controlling lateral sway during bimanual suspensory locomotion. This study examines the bony and muscular anatomy of the prehensile tail as well as the kinematics of tail use during tail-assisted brachiation in two primates, Ateles and Lagothrix. These two platyrrhines differ in anatomy and in the frequency and kinematics of suspensory locomotion. Lagothrix is stockier, has shorter forelimbs, and spends more time traveling quadrupedally and less time using bimanual suspensory locomotion than does Ateles. In addition, previous studies showed that Ateles exhibits greater hyperextension of the tail, uses its tail to grip only on alternate handholds, and has a larger abductor caudae medialis muscle compared to Lagothrix. In order to investigate the relationship between anatomy and behavior concerning the prehensile tail, osteological data and kinematic data were collected for Ateles fusciceps and Lagothrix lagothricha. The results demonstrate that Ateles has more numerous and smaller caudal elements, particularly in the proximal tail region. In addition, transverse processes are relatively wider, and sacro-caudal articulation is more acute in Ateles compared to Lagothrix. These differences reflect the larger abductor muscle mass and greater hyperextension in Ateles. In addition, Ateles shows fewer side-to-side movements during tail-assisted brachiation than does Lagothrix. These data support the notion that the prehensile tail represents a critical dynamic element in the tail-assisted brachiation of Ateles, and may be useful in developing inferences concerning behavior in fossil primates.     

Reproducibility and correlation study of three deoxyribonucleic acid hybridization procedures

Reproducibility of relative binding ratios (RBR) was studied with 26 labeled DNA-unlabeled DNA hybridization reactions carried out at two temperatures (60 and 75°C) and following three procedures: the S1-nuclease method with precipitation of S1-resistant DNA by trichloroacetic acid (S1-TCA), the S1-nuclease method with adsorption of S1-resistant DNA onto DE81 filters (S1-DE81), and the hydroxyapatite (HA) method. Analyses of variance indicated that different hybridization methods give different RBR, but similar percent divirgence (ΔT _m) results. A curvilinear relationship was found between RBR data obtained with S1-TCA and HA procedures at 60 or 75°C, and between 60°C RBR data obtained with S1-DE81 and HA procedures. At 75°C, RBR obtained with S1-DE81 and HA methods are comparable without any transformation of the data.     

Wabusk of the Omushkegouk: Cree-Polar Bear (Ursus maritimus) Interactions in Northern Ontario

In order to understand wabusk (polar bear, Ursus maritimus) behaviours and interactions with people in the Hudson Bay lowlands of northern Ontario we conducted this collaborative study of Cree kiskayndamowin/knowledge. Our findings reveal that Cree knowledge supports previously published information on polar bears, while adding further contextual findings: that male polar bears travel greater distances into the muskeg than previously recorded; that wabusk prey on amisk (beaver, Castor canadensis); that wabusk interact with muskwa (black bears, Ursus americanus); and that human-polar bear interactions occur in this region of northern Canada. Bearing in mind that Cree knowledge has been recognized in wildlife management strategies (i.e., for beaver, caribou and moose) elsewhere in Canada, this particular body of information is timely, especially since polar bears are considered threatened under the Ontario Endangered Species Act, and the province is developing a recovery strategy for the Southern Hudson Bay polar bear population. The federal government is also contemplating listing polar bears in Canada as a “species of special concern” under the Species at Risk Act (SARA). While it is unclear as to how these decisions will impact the Cree-polar interactions, the listing of polar bears by both governments, but especially the provincial government of Ontario, must recognize treaty and Aboriginal rights, acknowledge its duties to consult and properly accommodate Aboriginal people’s views, incorporate Cree kiskayndamowin/knowledge of wabusk, and re-examine the proposed Wabusk Co-Management Agreement draft developed by the Ontario Ministry of Natural Resources (OMNR) and Coastal Cree First Nations of Northern Ontario in 1994. The article provides recommendations that highlight how the Northern Cree First Nations, through the development of the Recovery Strategy for Polar Bear in Ontario, can become engaged in the management of wabusk in Ontario and throughout Canada.     

Biochemical properties of rat liver mitochondrial aldehyde dehydrogenase with respect to oxidation of formaldehyde.

The oxidation of formaldehyde by rat liver mitochondria in the presence of 50 mM phosphate was enhanced 2-fold by exogenous NAD+. Absolute requirement of NAD+ for formaldehyde oxidation was demonstrated by depleting the mitochondria of their NAD+ content (4.6 nmol/mg of protein), followed by reincorporation of the NAD+ into the depleted mitochondria. Aldehyde (formaldehyde) dehydrogenase activity was completely abolished in the depleted mitochondria, but the enzyme activity was restored to control levels following reincorporation of the pyridine nucleotide. Phosphate stimulation of formaldehyde oxidation could not be explained fully by the phosphate-induced swelling which enhances membrane permeability to NAD+, since stimulation of the enzyme activity by increased phosphate concentrations was still observed in the absence of exogenous NAD+. The Km for formaldehyde oxidation by the mitochondria was found to be 0.38 nM, a value similar to that obtained with varying concentrations of NAD+; both Vmax values were very similar, giving a value of 70 to 80 nmol/min/mg of protein. The pH optimum for the mitochondrial enzyme was 8.0. Inhibition of the enzyme activity by anaerobiosis was apparently due to the inability of the respiratory chain to oxidize the generated NADH. The inhibition of mitochondrial formaldehyde oxidation by succinate was found to be due to a lowering of the NAD+ level in the mitochondria. Succinate also inhibited acetaldehyde oxidation by the mitochondria. Malonate, a competitive inhibitor of succinic dehydrogenase, blocked the inhibitory effect of succinate. The respiratory chain inhibitors, rotenone, and antimycin A plus succinate, strongly inhibited formaldehyde oxidation by apparently the same mechanism, although the crude enzyme preparation (freed from the membrane) was slightly sensitive to rotenone. The mitochondria were subfractionated, and 85% of the enzyme activity was found in the inner membrane fraction (mitoplast). Furthermore, separation into inner membrane and matrix components indicated a distribution of aldehyde dehydrogenase activity similar to malic dehydrogenase.