Esculin hydrolysis by Streptococcus dysgalactiae

In a mastitis control program based on eradication of intramammary infection, it is important to differentiate streptococci. According to earlier reports, Streptococcus dysgalactiae was unable to hydrolyze esculin. Preliminary data from the present study indicated that under optimal conditions, some strains of S dysgalactiae were capable of esculin hydrolysis. In a study of 45 strains of S dysgalactiae, 55.5% were able to hydrolyze esculin. In the past, these organisms would probably have been identified as Streptococcus uberis. Streptococcus dysgalactiae is more sensitive to antibiotics than S uberis, and the infection is easier to eradicate from infected glands.     

Habituation and tonic immobility in domestic chickens

The habituation of tonic immobility in chickens was examined in six studies. It was shown that repeated elicitation of immobility, and not just handling, was responsible for reduced response durations after multiple exposures to manual restraint. Habituation was a function of the number of stimulus presentations and, in addition, proved surprisingly durable, with diminished reactions using lasting at least 2.5 mo. Strain differences were found in the number of trials required to reach a criteria of habituation, and habituation proceeded faster when immobility termination was self-paced as opposed to experimenter induced. Also, massed trials produced robust sensitization effects rather than diminished responsiveness.     

Vitamin D metabolite-binding proteins in human tissue

Serum and post-microsomal supernatants of human lymphocyte, erythrocyte, skeletal muscle and parathyroid adenoma homogenates were examined for specific binding of 25-hydroxycholecalciferol (25-OHD3) and 1, 25-dihydroxycholecalciferol (1,25-(OH)2D3). Muscle, lymphocytes and parathyroid adenomata extracts contained a 6-S 25-OHD3-binding protein which was not found in erythrocyte extracts, and which was distinct from the smaller serum transport alpha-globulin. A cathodal, 1, 25-(OH)2D3-binding protein, which sedimented at 3-4 S was also detected in parathyroid tissue. These observations suggest the possibility of direct physiologic interaction between vitamin D metabolites and nucleated human tissues other than intestine and bone.     

Sex differences in responsiveness to babies among mature adults.

Interest in babies, a feminine sex-typed behavior, was assessed in 30 parents of adolescents, 28 parents whose grown children were no longer living at home, and 26 grandparents of an infant. Measures included responsivity to an unfamiliar baby in a waiting room situation, interest in pictures of babies, and the Bem Sex-Role Inventory. Contrasting expectations of the course of male vs female reactions to babies are suggested by trait theory, sociobiology, and a functional-based role theory of sex differences. Across a variety of indices, grandparents demonstrated more interest in babies than did the other parent groups. Grandmothers were more sensitive to the baby's elicitations than grandfathers. The stage-of-life findings and sex differences support a functional-based role theory, that is, sex differences serve a function at the time they are manifested. (18 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Sensitivity to interaural time differences in the medial superior olive of a small mammal, the Mexican free-tailed bat

Neurons in the medial superior olive (MSO) are thought to encode interaural time differences (ITDs), the main binaural cues used for localizing low-frequency sounds in the horizontal plane. The underlying mechanism is supposed to rely on a coincidence of excitatory inputs from the two ears that are phase-locked to either the stimulus frequency or the stimulus envelope. Extracellular recordings from MSO neurons in several mammals conform with this theory. However, there are two aspects that remain puzzling. The first concerns the role of the MSO in small mammals that have relatively poor low-frequency hearing and whose heads generate only very small ITDs. The second puzzling aspect of the scenario concerns the role of the prominent binaural inhibitory inputs to MSO neurons. We examined these two unresolved issues by recording from MSO cells in the Mexican free-tailed bat. Using sinusoidally amplitude-modulated tones, we found that the ITD sensitivities of many MSO cells in the bat were remarkably similar to those reported for larger mammals. Our data also indicate an important role for inhibition in sharpening ITD sensitivity and increasing the dynamic range of ITD functions. A simple model of ITD coding based on the timing of multiple inputs is proposed. Additionally, our data suggest that ITD coding is a by-product of a neuronal circuit that processes the temporal structure of sounds. Because of the free-tailed bat's small head size, ITD coding is most likely not the major function of the MSO in this small mammal and probably other small mammals.     

Comparison of tension band wiring and lateral mass plating for subaxial posterior cervical fusion

BACKGROUND: Two instrumentation methods for subaxial posterior cervical fusion are compared in terms of efficacy, morbidity, and significant cost-related variables. METHOD: Thirty-four patients with tension band wiring and 14 patients with lateral mass plating are retrospectively compared in a single surgeon's experience between 1989 and early 1995. RESULTS: Both groups were similar in regard to operative indication (about 40% trauma, 30% degenerative changes in each group), postoperative immobilization (hard collar only used in 82% of patients wired and 79% of patients plated), and number of levels fused (mean, 1.7 in each group). Mean follow-up is 23 months for wiring and 35 months for plating. Pseudoarthrodesis occurred in one patient undergoing wiring and in none of the patients plated. Both methods resulted in complications (7 in 34 cases of wiring, 4 in 14 cases of plating), but no patient experienced neurologic decline. Statistically significant differences between the two groups were found for estimated blood loss, operating room time, and hardware cost, but not for postoperative orthosis or length of stay. CONCLUSION: In some instances when subaxial posterior fusion is performed, tension band wiring may be more cost-efficient. Tension band wiring and lateral mass plating seem to have comparable efficacy and morbidity, but the indications for each technique differ.     

The estimation and control of terrestrial inertial navigation system errors due to vertical deflections

Deflections of the vertical introduce errors into terrestrial inertial navigation systems. In many situations, these errors prove to be intolerable. However, if vertical deflection data are available prior to a mission, this information can in principle be used to reduce the navigation system errors. It is assumed that measurements of vertical deflections plus noise are available at equally spaced points on a square grid. The accuracy to which the Schuler loop errors can be controlled, given this set of measurements, is bounded by the accuracy to which the uncontrolled Schuler loop errors can be estimated given the same set of measurements. Thus lower bounds on the accuracy of the compensated system may be established by obtaining the optimal error covariances of the equivalent estimation problem. It is shown that the estimation problem can be modeled as a linear smoothing problem if the vehicle travels at a constant heading and at a constant velocity. The appropriate error covariances are found using the known techniques of optimal linear estimation theory, Kalman filtering and smoothing, both at and between the grid points.     

Pulpotomy as an alternative to canine tooth extraction in monkeys [Macaca mulatta]

An effective method for sealing pulp canals after partial removal of canine tooth crowns from adult rhesus monkeys is described.