Showing papers by "University at Buffalo published in 1979"

Practical methods of estimating volume and fresh weight of bird eggs

Abstract: Bird eggs begin to lose weight as soon as they are laid but their volume and linear dimensions do not change during incubation. The volume of an egg can be estimated within 2% from the relationship: Volume = 0.51. LB2, where L is the length and B is the breadth (maximum diameter). The fresh weight of an egg can be estimated within 2% from the relationship: Weight = Kw' LB 2, where K w is a species-specific constant that can be determined empirically or calculated from published data. Received 25 April 1978, accepted 28 October 1978. IT is frequently useful to know the fresh weight of a bird's egg. One reason is that many aspects of the biology of bird eggs can be predicted from their weight and these predicted values can be used when empirical data are lacking. Alternatively, one way to detect adaptations to unusual situations is by comparing observed values with values predicted for an "average" egg. Some of the parameters that can be predicted from weight are metabolic rate (Rahn et al. 1974), incubation period (Rahn and Ar 1974), water vapor conductance (Ar et al. 1974), the daily rate of water loss (Drent 1970), surface area, density, and shell weight (Paganelli et al. 1974), and the relation of egg weight to adult body weight (Huxley 1923-24, Rahn et al. 1975). Additionally, accurate values of fresh egg weight are required for the calculation of fractional weight loss from the daily rate of water loss (Rahn and Ar 1974) and the estimation of incubation age (Westerkov 1950). However, fresh egg weight can only be determined at the time of laying because the egg immediately begins to lose weight by diffusion of water vapor. This daily loss is proportional to the 0.74 power of egg weight (Drent 1970) and totals about 16% of the initial weight by the end of incubation (Drent 1975). As a consequence, while a great deal of information is available on egg dimensions, there are few reliable reports of fresh egg weight. Fortunately, the linear dimensions of eggs do not change during incu- bation, and in the present paper I show that they can be used to predict egg volume and fresh egg weight. Several authors have shown that the volume of a bird egg can be estimated from its linear dimensions (Bergtold 1929, Worth 1940, Westerkov 1950, Stonehouse 1963), and Preston (1974) suggested a more complex approach. In the present paper, I evaluate the accuracy with which volume (V) can be predicted from linear dimen- sions (L = length, B = breadth or maximum diameter), using the equation: V = Kv' LB 2

Periodontal Therapy in Humans: I. Microbiological and Clinical Effects of a Single Course of Periodontal Scaling and Root Planing, and of Adjunctive Tetracycline Therapy

Abstract: The present results showed that maarked and long-lasting changes in the subgingival microflora associated with periodontal disease could be achieved by a single course of periodontal treatment. Immediately following therapy, the total number of subgingival organisms decreased 10- to 100-fold and the proportions of cultivable Gram negative organisms and anaerobic organisms generally decreased 3- to 4-fold or more. After treatment, most periodontal pockets were populated by a scant microflora predominated by facultative Actinomyces and Streptococcus species. The kinetics of the subgingival bacterial recolonization revealed that the total cell counts and the proportions of spirochetes and Capnocytophaga species did not reach their pretreatment levels even after 6 months. Other Gram negative anaerobic species returned to pretreatment proportions after 3 to 6 months. Several Gram positive species exhibited higher posttreatment than pretreatment proportions throughout the 6 months study. The microbiological shifts paralleled significant changes in the clinical status of the periodontal tissues. Following therapy, the periodontal pocket depths decreased generally 1 to 4 mm, the gingival inflammatory index, the gingival fluid flow, and the suppurative index were generally lower, and nine of 33 test pockets examined showed apposition of alveolar bone. The microbiological and clinical changes described were exhibited by two patients treated with periodontal scaling and root planing alone and by two patients treated with the adjunctive use of systemic tetracycline therapy. In two other patients, mechanical periodontal therapy only slightly reduced the total number of subgingival organisms and the proportions of spirochetes and other Gram negative anaerobic rods. A shift in the subgingival microbial composition was achieved in these two patients after tetracycline therapy. The following model for treatment of periodontal disease is proposed: (1) Conventional therapy including thorough periodontal scaling and root planing; (2) Monitoring the subgingival flora and the clinical course; and (3) Use of antimicrobial therapy in refractory cases. Further studies are needed to develop means for rapid identification of refractory patients, and to determine the optimal antimicrobial agent, the optimal route of administration, and the optimal dosage regime.

Techniques of Measuring Contact Angles

Abstract: The previous chapter was largely theoretical, in that it dealt with the interpretation of contact angle results in terms of solid surface energies. It also delved into the question of how the structure of a solid surface affects the contact angle that a liquid forms on the solid. The level of structure considered there included features that are not macroscopically observed, such as microheterogeneities, or minute peaks, pits, hills, and grooves in various geometries. Their existence may be inferred from certain observations, such as contact angle hysteresis, and sometimes they can be observed directly, e.g., with the optical or electron microscope.

Do natural killer cells engage in regulated reactions against self to ensure homeostasis

Abstract: Host reactivities not requiring immunization in the mouse, especially natural resistance of irradiated animals to accept grafts of normal or malignant hemopoietic cells, were compared with NK activity against the YAC-1 lymphoma. The effects of several independent variables known to influence natural resistance in vivo had a similar effect on the NK system. Figure 12 lists an impressive array of shared properties and positive correlations. In contrast, the distinctions were few and minor. Many of the positive correlations were of particular significance since the experimental variables either have opposing or no effects on conventional induced immunity. The multiplicity and pervasiveness of these correlations suggest that the cellular mechanisms underlying natural reactivities are similar or common. Cytotoxic effectors mediating natural resistance to normal cells, tumors, and cells infected with intracellular pathogens may be distinct in terms of target selectivity, yet belong to a single cell lineage subject to common regulatory influences for differentiation and function. Regulation of reactivity via suppressor cells was studied in the NK system only. The spleens of mice selected for low levels of NK activity (resulting from young age, irradiation, and treatment with the macrophage-active agents l-carrageenan or hydrocortisone acetate) contained cells capable of inhibiting the lytic function of NK effectors taken from untreated adult donors. All the suppressor cells studied were thymus-independent, as judged by their occurrence in spleens of genetically athymic mice; the suppressive function was resistant to 2000 rads of gamma-rays administered in vitro and was not restricted by the major histocompatibility complex, without exception. However, two major classes of suppressors were identified: (a) macrophagelike cells inducible by l-carrageenan or hydrocortisone acetate, and (b) nonadherent cells found in spleens of untreated infants and of irradiated adult mice. It is proposed that the suppression of NK cytolysis demonstrated in vitro was a manifestation of regulatory mechanisms modulating the level of NK activity in vivo. Macrophagelike cells that are induced, activated, or inactivated by bacteria, viruses, hormones, and other agents may act as regulators of differentiation, maturation, and function of cells belonging to the NK lineage. Nonadherent cells could be either a distinct class of suppressors or immature NK cells capable of binding but not lysing target cells. In the latter case, regulation would be achieved via competitive binding of targets by pre-NK cells presumably in dynamic equilibrium with functional (i.e. matured) NK effectors.

Use of serum creatinine concentrations to determine renal function.

Abstract: Serum creatinine concentrations are widely used clinically as an index of renal function. In stable normal or reduced renal function they are determined by the rate of creatinine production and the endogenous creatinine clearance, and, during changing renal function, also by the apparent volume of distribution of creatinine. These determinants of serum creatinine concentrations, however, are affected by age, sex and body weight. The rate of creatinine production is proportional to body weight, and it decreases with age and is slower in females than in males. The endogenous creatinine clearance decreases with age and is lower in females than in males. The apparent volume of distribution of creatinine is equal to the total body water, which is proportional to body weight, and it decreases with age and is lower in females than in males. The individual relationships between the determinants of serum creatinine concentrations and age, sex, and body weight on the relationship between normal and reduced renal function and serum creatinine concentrations are illustrated by simulations. Equations are derived to predict endogenous creatinine clearance from serum creatinine concentrations, and a nomogram is presented for determining relative renal function from serum creatinine concentrations, which take into account the age, sex and body weight of the individual patient. It is recommended for rapid clinical evaluation of stable normal or reduced renal function. When rapid changes are expected clinically, however, it is recommended to use a mid urine collection period serum creatinine sample for creatinine clearance determination.

Vitamin A and Lung Cancer

Abstract: Retrospective dietary and smoking data were gathered by interview of 292 white male patients with lung cancer and 801 control patients with nonrespiratory, nonneoplastic diseases at Roswell Park Memorial Institute, Buffalo, New York. A computed index of vitamin A intake was used to differentiate lung cancer patients from controls. Lung cancer patients had lower values than did controls. The reduced relative risk (RR) of lung cancer associated with vitamin A was most evident among men who smoked heavily. For them, a dose-response relationship increasing to an RR of 2.4 for low values of the index was observed. Frequency of daily milk drinking was lower among patients with lung cancer. Lower RR was found among the men who smoked heavily and frequently consumed carrots. These findings are consistent with evidence from animal studies on inhibition of tumor incidence by retinoids and with previous findings in prospective and retrospective epidemiologic studies.

Hydroxyurea or placebo combined with radiation to treat stages iiib and iv cervical cancer confined to the pelvis

Abstract: In a prospective study by the Gynecologic Oncology Group (GOG), 104 evaluable patients with cervical squamous cell carcinoma Stages IIIB and IVA were randomly assigned to treatment with hydroxyurea or placebo in combination with radiation. There were no deaths resulting from the treatment. Hematologic toxicity was more common and more severe in patients who received hydroxyurea. Response was evaluated in terms of complete tumor regression, duration of progression-free interval and survival probability. By all those parameters the response was significantly better in the groups of patients receiving hydroxyurea.

Food and Habitat Partitioning Between Rock Bass (Ambloplites rupestris) and Smallmouth Bass (Micropterus dolomieui) Young of the Year

Abstract: Young-of-the-year rock bass and smallmouth bass were studied in 1977 along the west shore of Grand Island in the upper Niagara River, New York. Fish were collected every 2 weeks by shore scining. The average summer growth rate of smallmouth bass was 1.15 mm/day and of rock bass, 0.51 mm/day. Population estimates and laboratory habitat preference studies indicated that smallmouth bass preferred a rocky substrate whereas rock bass preferred a heavily vegetated substrate. Smallmouth bass less than 40 mm in total length (TL) fed mainly on zooplankton, chironomid larvae, mayfly nymphs, and amphipods, and when greater than 40 mm TL fed on amphipods, adult caddis flies, and small fish. Rock bass young of the year of all sizes fed on amphipods, copepods, and several other aquatic invertebrates. Levins' average niche breadth or dietary diversity value for smallmouth bass was 2.51, and for rock bass, 3.78. Levins' dietary overlap values were highest early in the season, 0.71–0.88, and decreased to 0.05–0.1...

Measuring Surfaces Space-Coded By A Laser-Projected Dot Matrix

Abstract: We describe a mathematically-rigorous easy-to-use portable topographical mapping technique that within seconds or less can determine the heights of a surface at 16,000 (128x128) distinct sample points. The necessary data derive from (narrow-optical-bandpass) TV images of a surface which has been illuminated and space-coded by a rapid sequence of laser-projected dot patterns.© (1979) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Aggregation of Amphiphiles as Micelles or Vesicles in Aqueous Media

Abstract: The physical factors responsible for the aggregation of amphiphiles in aqueous media are examined and expressions for their contribution to the attractive or repulsive components of the free energy change of aggregation are established. Whereas in previous treatments, an arbitrary repulsive force was necessary to explain the behavior of nonionic systems, no such ad hoc assumption is made here. Rather the free energy changes due to interfacial tension at the hydrocarbon core (of the aggregates)-water interface and to the loss of a part of translational and rotational degrees of freedom of the amphiphiles when they aggregate are the two main repulsive contributions. On the other hand, the factors favoring aggregation are: (i) the van der Waals interactions between the hydrocarbon tails of the amphiphiles, and (ii) the structural changes in water and the changes in the interactions between amphiphiles and water resulting from aggregation. For ionic and zwitterionic amphiphilar systems additional free energy contributions are included to account for the repulsive electrostatic interactions between the head groups. For vesicles, the repulsion caused by the overlapping electrical double layers inside the vesicles is also considered. The expressions established for the various free energy changes associated with aggregation are used to examine the formation of micelles and vesicles, from single and double chain amphiphiles with nonionic, ionic, or zwitterionic head groups. In general, single chain amphiphiles aggregate as micelles, rather than as vesicles, for all types of polar head groups. Depending upon the nature of the head groups small and/or large micelles can form. Nonionic amphiphiles which have head groups of small cross-sectional areas form large micelles, whereas those with large cross-section aggregate as small micelles. This happens because the repulsion caused by the loss of translational degrees of freedom is larger in the latter of the two cases. Ionic or zwitterionic amphiphiles form small micelles even though they have small head groups because of the electrostatic repulsion between the head groups. At large ionic strengths, large micelles can form because the repulsive interactions between the head groups are small. Nonionic double chain amphiphiles aggregate predominantly as vesicles. Ionic or zwitterionic double chain amphiphiles aggregate as micelles when the electrostatic repulsion between the head groups is large and as vesicles when this repulsion is small. However for intermediate values of these interactions both micelles and vesicles form depending upon the length of the hydrocarbon tail. Most biologically significant double chain amphiphiles have long, complex polar head groups and they aggregate as micelles when the hydrocarbon tail length is short, even if the electrostatic repulsion between the head groups is weak; but they aggregate as vesicles when the hydrocarbon tail length is long. The size distributions calculated for different types of amphiphiles can be unimodal, representing a single population of aggregates, bimodal, or trimodal representing the coexistence of two or three distinct populations of aggregates. The three possible populations are small micelles, large micelles, and vesicles.

A Comparison of the Internal Validity of Alternative Parameter Estimation Methods in Decompositional Multiattribute Preference Models

Abstract: Since 1971, interest in the use of decompositional multiattribute preference models in marketing has been increasing. The applications have varied in terms of the type of data used, behavior predic...

A New Approach to the Emission Computerized Tomography Problem: Simultaneous Calculation of Attenuation and Activity Coefficients

Abstract: In order to obtain truly quantitative reconstruction of gamma-emitter concentration in Emission Computerized Tomography (ECT) the attenuation within the region of interest has to be accounted for. In this report we propose to calculate simultaneously attenuation and activity concentration coefficients. Starting from the system of non-linear equations which describes the model of single photon gamma-ray emission in a discretized form we show how to reduce it to a mixed convex-concave feasibility problem and apply to it our method of Cyclic Subgradient Projections (CSP). This approach is discussed and some experimental results in its favor are presented.

Facial feature determinants of perceived infant attractiveness

Abstract: Previous studies of infant facial characteristics that influence adult behavior have used drawings to vary infant facial features. The present study used actual infant faces rather than drawings. Facial feature variations were related to adults' perceptions of infant cuteness using a multiple correlational approach. Ten photographs at each of six age levels were rated for cuteness; then 14 facial features were measured. Results suggest that studies using line drawings have varied facial features beyond the range found among actual infants. Nevertheless, facial feature combinations were predictive of perceived cuteness; a cute infant is likely to have short and narrow features, large eyes and pupils, and a large forehead. The potential impact of perceived attractiveness on the organization of adult—infant relationships is discussed.

Selective oxidation of hydrocarbons on composite oxides

Abstract: A catalyst for the selective oxidation of hydrocarbons to unsaturated aldehydes, acids, acid anhydrides, divinyls, or styrenes has to perform several functions. First, it must supply a limited amount of oxygen to the reactant, sufficient to allow the formation of the desired product but not enough to allow complete oxidation. Further, it must provide appropriate sites for the adsorption of the hydrocarbons in deformed, reactive states. Last, the catalyst should be capable of transferring electrons from and to the reactants. These three demanding characteristics of an active catalyst impose severe limitations on the systems that can effectively perform selective oxidation reactions. Therefore catalyst selectivity, normally measured by the rate of formation of the specific product relative to that of undesired products, is sensitive to reaction conditions (temperature, feed rate, feed composition, and reactor design) and is very dependent on the details of the structure of the catalyst itself, its ...

Psychological Stress Reduction During Dental Procedures

Abstract: Behavioral methods of patient stress reduction during amalgam restorations were evaluated. Eighty adult patients were randomly assigned to one of four groups of 20 each: a control group, a relaxation group, a perceived control group, and an active distraction group. Both relaxation and distraction were found to be effective in reducing patient discomfort.

Age-related changes in melanocytic naevi.

Abstract: The prevalence of melanocytic naevi in various age groups suggests a natural history characterized by a growth phase followed by a relatively long period of quiescence and eventual involution. In a clinical and histopathological study of pigmented lesions in 1058 newborn infants, Walton, Jacobs & Cox (1976) found that only i-oi/;, had melanocytic naevi. Other clinical studies have shown that the number of melanocytic naevi per person increases progressi;vely through childhood, adolescence and early adulthood (Stegmaier & Becker, 1960; Nicholls, 1968, 1973). Nicholls (1973) observed a peak number of moles at age 15 in males and at age 20-29 in females. Melanocytic naevi are almost universally present in young adults. The average number per person in this age group ranges from 15 to 40 (Pack, Lenson & Gerber, 1952; Stegmaier & Becker, 1963). With advancing age, there is a progressive decrease in the number of moles. In a painstaking histological study of all lesions suspected of being moles in a group of patients more than 50 years of age, Stegmaier found an average of only 4 naevi per person (Stegmaier, 1959). Nicholls (1973) observed that naevi rarely are present in persons aged 80 years. In addition to these epidemiological studies which indicate that naevi involute, a few instances of spontaneous disappearance of naevi without the halo phenomenon have been documented (Braitman, 1958; Shelley, i960). The present study was designed to determine the nature and statistical significance of histologic changes in melanocytic naevi with advancing age with particular attention to the reciprocal changes between the melanocytic component and the stroma.

The use of relaxation and distraction to reduce psychological stress during dental procedures

Abstract: This report describes techniques that can be easily adapted in a dental office to relieve anxiety and slress Relaxation and distraction techniques designed to reduce stress during operative dental procedures were evaluated Both techniques can be effective in alleviating anxiety and stress

Extracranial-Intracranial Arterial Bypass in the Treatment of Aneurysms of the Carotid and Middle Cerebral Arteries

Abstract: Eleven patients with lesions of the internal carotid and middle cerebral arteries that could not be treated by direct approach are presented. Major vessel occlusion was chosen as definitive therapy. Prophylactic extracranial-intracranial bypass was employed in an attempt to reduce the incidence of ischemic complications. Emphasis is placed on complications, from which several important lessons were learned. Our best results occurred in patients with carotid artery lesions treated with bypass and immediate internal carotid ligation. We believe this to be an effective and safe mode of therapy in cases in which direct approach is not feasible. The low risk and high potential benefit of prophylactic bypass justifies its use before major vessel occlusion in selected cases.

Contact Angles and the Surface Free Energy of Solids

Abstract: This chapter, and the following one by Neumann and Good, deal with the measurement of contact angles in three-phase systems. The contact angle is, intrinsically, a macroscopic property, and one that should be amenable to a phenomenological treatment, e.g., to measurement without regard to its thermodynamic or microscopic interpretation. But inevitably, the desire for a thermodynamic and molecular interpretation arises. In addition, some fundamental questions about solid surfaces come up, and the problem of hysteresis must be given explicit consideration. So there is a need to go beyond phenomenology.