Definition and solution of a stochastic inverse problem for the Manning's n parameter field in hydrodynamic models.

The uncertainty in spatially heterogeneous Manning's n fields is quantified using a novel formulation and numerical solution of stochastic inverse problems for physics-based models. The uncertainty is quantified in terms of a probability measure and the physics-based model considered here is the state-of-the-art ADCIRC model although the presented methodology applies to other hydrodynamic models. An accessible overview of the formulation and solution of the stochastic inverse problem in a mathematically rigorous framework based on measure theory is presented. Technical details that arise in practice by applying the framework to determine the Manning's n parameter field in a shallow water equation model used for coastal hydrodynamics are presented and an efficient computational algorithm and open source software package are developed. A new notion of "condition" for the stochastic inverse problem is defined and analyzed as it relates to the computation of probabilities. This notion of condition is investigated to determine effective output quantities of interest of maximum water elevations to use for the inverse problem for the Manning's n parameter and the effect on model predictions is analyzed.

A numerical method for solving a stochastic inverse problem for parameters.

We review recent work (Briedt et al., 2011., 2012) on a new approach to the formulation and solution of the stochastic inverse parameter determination problem, i.e. determine the random variation of input parameters to a map that matches specified random variation in the output of the map, and then apply the various aspects of this method to the interesting Brusselator model. In this approach, the problem is formulated as an inverse problem for an integral equation using the Law of Total Probability. The solution method employs two steps: (1) we construct a systematic method for approximating set-valued inverse solutions and (2) we construct a computational approach to compute a measure-theoretic approximation of the probability measure on the input space imparted by the approximate set-valued inverse that solves the inverse problem. In addition to convergence analysis, we carry out an a posteriori error analysis on the computed probability distribution that takes into account all sources of stochastic and deterministic error.

A COMPUTATIONAL MEASURE THEORETIC APPROACH TO INVERSE SENSITIVITY PROBLEMS II: A POSTERIORI ERROR ANALYSIS.

In part one of this paper [T. Butler and D. Estep, SIAM J. Numer. Anal., to appear], we develop and analyze a numerical method to solve a probabilistic inverse sensitivity analysis problem for a smooth deterministic map assuming that the map can be evaluated exactly. In this paper, we treat the situation in which the output of the map is determined implicitly and is difficult and/or expensive to evaluate, e.g., requiring the solution of a differential equation, and hence the output of the map is approximated numerically. The main goal is an a posteriori error estimate that can be used to evaluate the accuracy of the computed distribution solving the inverse problem, taking into account all sources of statistical and numerical deterministic errors. We present a general analysis for the method and then apply the analysis to the case of a map determined by the solution of an initial value problem.

A MEASURE-THEORETIC COMPUTATIONAL METHOD FOR INVERSE SENSITIVITY PROBLEMS I: METHOD AND ANALYSIS.

We consider the inverse sensitivity analysis problem of quantifying the uncertainty of inputs to a deterministic map given specified uncertainty in a linear functional of the output of the map. This is a version of the model calibration or parameter estimation problem for a deterministic map. We assume that the uncertainty in the quantity of interest is represented by a random variable with a given distribution, and we use the law of total probability to express the inverse problem for the corresponding probability measure on the input space. Assuming that the map from the input space to the quantity of interest is smooth, we solve the generally ill-posed inverse problem by using the implicit function theorem to derive a method for approximating the set-valued inverse that provides an approximate quotient space representation of the input space. We then derive an efficient computational approach to compute a measure theoretic approximation of the probability measure on the input space imparted by the approximate set-valued inverse that solves the inverse problem.

Colic in breast-milk-fed infants: treatment by temporary substitution of neocate infant formula.

Infant colic is a common problem characterized by excessive crying and fussing. We examined whether colic symptoms of exclusively breast-milk-fed infants would be improved by temporary substitution of Neocate, an amino acid-based infant formula, for breast milk. Six infants with colic were studied using Barr-type infant behavior diaries for a 3-5 d baseline period while they continued exclusive breast-milk-feeding, followed by a 4-8 d intervention period of exclusive Neocate feeding. All infants showed improvement in distressed behavior during intervention; five of the six improved within 1-2 d. For the period after 1 d of Neocate feeding, the total recorded crying and fussing time was reduced by an average of 42%, representing a decrease of 1.0 to 3.1 h daily. A significant difference was found between cry and fuss time at baseline versus during exclusive Neocate use. Concurrent with Neocate intervention, mothers strictly avoided all milk and dairy products. After colic symptoms improved, infants were reintroduced to breast milk, which was reasonably well tolerated in four of the six infants. Two infants had rapid recurrences of crying and fussing upon return to breastfeeding and required an additional period of Neocate feedings before subsequent reintroduction to breastfeeding. All infants exhibited colic symptoms when directly or indirectly challenged with bovine IgG (BGG), suggesting that BGG may play an etiologic role in colic. We propose that a brief intervention with Neocate, coupled with strict maternal avoidance of milk and dairy products under direct supervision of a lactation consultant, may be an effective treatment for colic in some breast-milk-fed infants.

Treatment of infant colic with amino acid-based infant formula: a preliminary study.

Infant colic, a common disorder of infancy, is characterized by excessive crying and fussing. In this preliminary study we examined whether Neocate, an amino acid-based formula, would be accepted by formula-fed infants with colic, 3-7 wk of age, and whether Neocate would improve their symptoms. Six infants with colic were studied using Barr-type infant behavior diaries for 3-6 d on their current formula and then for 5-17 d on Neocate exclusively. All infants tolerated Neocate well and all improved, usually within 1-2 d. The total time spent crying and fussing was reduced by an average of 45%, representing a decrease of 1.0 to 5.2 h daily. After colic symptoms improved, infants were challenged with oral doses of 75 mg of bovine IgG at a 1 mg/ml concentration in order to assess its potential role in colic. Bovine IgG challenges resulted in increased crying and fussing behavior, suggesting that this protein may be etiologically important.

Laboratory caging preferences in golden hamsters (Mesocricetus auratus).

Physical aspects of the laboratory environment, such as type of cage or bedding, are often ignored by investigators but may be quite important for the animals. We examined whether golden hamsters preferred living in wire mesh floored, stainless steel cages or solid floored, plastic cages with corn-cob litter. Forty hamsters of 2 ages were housed in wire or solid floored cages for 3 weeks. Caging preference was then tested using a choice apparatus in which hamsters could move freely between the 2 cages for 6 days. Scan data were collected on cage occupation and behaviour. Results showed that most hamsters preferred the solid floored cage with litter, but prolonged experience on wire led to a wire floored cage preference in 40% of these animals. Also, wire-housed hamsters showed higher levels of hoarding and lower levels of gnawing behaviour during testing, and spent significantly different amounts of time from litter-housed hamsters performing sleeping, exploring, grooming, gnawing, eating, and hoarding behaviours while on solid floored cages with litter. This study shows that previous housing condition can affect cage preferences and behaviour and supports the assertion that husbandry practices can be better evaluated by asking laboratory animals, rather than only humans, how their living conditions are perceived.

Sexual performance of rams as determined by maturation and sexual experience.

The purpose of this study was to compare the sexual performance of rams that differed in age (maturation) and sexual experience. Twenty-four ram lambs (8 mo of age) and 21 rams (20 mo of age) were individually exposed to four females in hormonally induced estrus for 30 min on five occasions, 7 d apart. Half (12) the ram lambs and nine of the yearlings were sexually naive at the start of testing (had been denied access to females since weaning); the remaining males were sexually experienced. The sexual performance of the virgin rams was poorer during the initial exposure to females than in subsequent tests, whereas the sexual behavior of the sexually experienced males did not change over the days of testing. Sexually naive ram lambs and rams exhibited an improvement in sexual performance between Tests 1 and 2; during Test 3 to 5 the sexual performance (ejaculations per test) of sexually naive and experienced rams was similar. The only effects of age (maturation) on sexual performance during the last three test days were a higher frequency of mounts without ejaculation plus mount attempts (P less than .03) and a greater number of mount interactions per ejaculation (P less than .02) by ram lambs. In conclusion, one or two relatively brief exposures to estrous females can bring the sexual performance of virgin rams up to levels comparable to that of experienced males. Also, ram lambs in good condition exhibit acceptable levels of sexual performance.

Kinship and affiliative behavior patterns in a captive group of Celebes black apes (Macaca nigra).

The influence of matrilineal kinship on four socially affiliative behavior patterns--grooming, contact, proximity, and play--was studied in a little-known primate species, the Celebes black ape (Macaca nigra). Twenty group-living black apes, comprising four genealogical groups, were observed for more than 100 hr; data were collected by the instantaneous scan technique. Animals spent more time than was expected by chance grooming, in contact with, and in proximity to their matrilineal relatives, but they did not play with relatives more than was expected. The proximal mechanisms responsible for these results are unknown, and increased familiarity among matrilineal relatives may have influenced the interaction patterns in the group. The results obtained in this study are similar to those of many others that demonstrate differential behavior toward kin, and they are consistent with the theory that animals may increase their inclusive fitness by interacting preferentially with relatives.

Sexual arousal in male pigtailed monkeys (Macaca nemestrina): effects of serial matings by two males.

Male sexual arousal was examined in pigtailed monkeys (Macaca nemestrina), with the postejaculatory interval (PEI) used as the dependent variable. In male-female pairs, the PEI is shortened by 60% of normal (control) values if the male observes another male copulating with his female partner. This result demonstrates that the normal PEI is not an absolute male refractory period; males are capable of copulating sooner, and they will do so when presented with certain behavioral stimuli. A possible functional interpretation of the result with regard to male reproductive competition is presented.

Sexual behavior of group-housed stumptail macaques (Macaca arctoides): temporal, demographic and sociosexual relationships.

A detailed quantitative analysis of sexual behavior in a social group of captive stumptail macaques was conducted. The distribution of copulations both over days and among animals, and the relationships between copulation and various sociosexual patterns were investigated. Copulations occurred erratically over days and were preferentially directed to a small minority of females. Most patterns of sociosexual behavior were at their highest rates during actual copulatory episodes, others occurred independent of ejaculation. It is suggested that the relationships between variables such as social rank, age and parity and sociosexual patterns are quite flexible and probably vary with the species, testing conditions and demographic make-up of the group.

Preliminary report of the effects of propranolol HCl on the discomfiture caused by niacin.

Subjective discomfort caused by nausea and hot, pruritic skin has been described in patients after ingestion of therapeutic dosages of niacin is shown by this study to be alleviated by propranolol HC1. A dosage of 2 mg, I.V., given incrementally, in a clinical trial of six patients is described. The peripheral vasodilator effects of niacin were attenuated in some subjects but not in others. However, all subjects reported relief of unpleasant symptoms. Serial vital signs were taken and no significant changes were found. It is postulated that propranolol HC1 exerts a calmative effect at the CNS level. In a series that utilized doses of 40 and 80 mg of propranolol HC1 taken orally 30 min prior to the ingestion of 500 or 1000 mg of niacin, a progressive increase in the onset of the niacin flush was observed. It is proposed that as the available plasma level of propranolol HC1 falls, the ratio of niacin to propranolol HC1 increases, exceeding the threshold at which the flush occurs. Both these studies suggest that further work is indicated to establish the possible therapeutic efficacy of propranolol HC1.

Canine salmonellosis: A review and report of dog to child transmission of Salmonella enteritidis.

Dogs have been shown to harbor 53 salmonellae serotypes. Multiple simultaneous infections with 2 to 4 serotypes have been observed. The prevalence of canine salmonellosis may be a high as 27 per cent. Salmonella typhimurium and S. anatum are the most common etiologic agents. Dogs commonly experience a sub-clinical course of salmonellosis. Some investigators state that the dog may serve as a source of human infections. A few reports in the literature have documented this fact. The transmissions of S. enteritidis from dog to child is described in this article.

Copulatory behavior of golden hamsters: effects on pregnancy.

Two experiments were conducted to study the role of male copulatory behavior in initiating physiological responses necessary for pregnancy in female hamsters. In Experiment 1, it was found that copulation beyond the first ejaculatory series is critical to attainment of maximal probabilities of pregnancy. Whereas all females became pregnant when mated to a criterion of sexual satiety, only 20 percent were pregnant after one ejaculatory series. The relationship between increased copulatory stimulation and increased probability of pregnancy was further refined in Experiment 2. Females required more than 4 ejaculatory series to maximize the probability of pregnancy. Mounts without intromission had no effect. Neither parturition number of ova shed, nor little size appeared affected by amount of copulatory stimulation. A coadaptation between the copulatory pattern of the males and the response systems of the females of several rodent species appears to have evolved and to aid successful reproduction.