Using Inside-Outside Algorithm for Estimation of the Offspring Distribution in Multitype Branching Processes

Multitype branching processes (MTBP) model branching structures, where the nodes of the resulting tree are particles of different types. Usually such a process is not observable in the sense of the whole tree, but only as the “generation” at a given moment in time, which consists of the number of particles of every type. This requires an EM-type algorithm to obtain a maximum likelihood (ML) estimate of the parameters of the branching process. Using a version of the inside-outside algorithm for stochastic context-free grammars (SCFG), such an estimate could be obtained for the offspring distribution of the process.

Em Estimation of the Offspring Distribution in Mutitype Branching Processes - a Model in Cell Kinetics

2000 Mathematics Subject Classification: 60J80, 60J85, 62P10, 92D25.

Robust Parametric Estimation of Branching Processes with a Random Number of Ancestors

2000 Mathematics Subject Classification: 60J80.

Asymptotic Behaviour of a Supercritical Galton-Watson Process with Controlled Binomial Migration

AMS subject classification: 60J80, 62F12, 62P10.

Parametric Estimation in Branching Processes with an Increasing Random Number of Ancestors

2000 Mathematics Subject Classification: 60J80, 62M05

Begging and food distribution in crimson rosella (Platycercus elegans) broods: why don't hungry chicks beg more?

Altricial nestlings solicit food by begging and engaging in scramble competition. Solicitation displays can thus signal both hunger and competitive ability. I examined nestling solicitation and parental responses in crimson rosellas (Platycercus elegans), a species in which parents engage in complex patterns of food allocation and appear to control the distribution of food. By manipulating the hunger of individual chicks and entire broods, I assessed how chick behaviours and parental food allocation varied with hatching rank, level of hunger, and intensity of nestling competition. Last-hatched chicks begged more than first-hatched chicks irrespective of individual hunger levels. The two parents combined fed individually hungry chicks more, but mothers and fathers varied in their responses to begging chicks: fathers fed last-hatched chicks in proportion to their begging intensity, whereas mothers fed chicks equally. Since fathers generally allocate more food to first-hatched chicks, fathers appear to use begging rates to adjust food allocation to non-preferred chicks within the brood. When I manipulated brood hunger levels, begging rates increased for first- and last-hatched chicks suggesting that chick begging rates are sensitive to the level of competition. This study shows that begging by rosella chicks does not correlate with hunger in a straightforward way and that the primary patterns of food allocation by parents art: not influenced by chick begging. Thus the benefits of increased begging may be limited for nestlings in this species.

Distribution of risk factors in parents and siblings of patients with early coronary artery disease

OBJECTIVE: Early coronary artery disease (CAD) is associated with risk factors (RF). Offspring of parents with a RF have a greater prevalence of them. However, the distribution of RF in parents and siblings of patients with early CAD is unknown. METHODS: The study comprised the parents and siblings of 42 patients with early CAD (< 45 years), 29 males. Their mean age was 39.5±3.7 years. The following major RF were analyzed: smoking (> 5 cigarretes/day), hypercholesterolemia (total cholesterol > 200 mg/dL), hypertension (diastolic blood pressure > 90 mmHg), and diabetes (glycemia > 126 mg/dL). RESULTS: Of a total of 102 RF, 4, 3, 2, and 1 were observed in, respectively, 5, 15, 15, and 7 patients with early CAD, the most prevalent being smoking (86%) and hypercholesterolemia (83%). Diabetes was observed in 15 (36%) and hypertension in 16 (38%) patients. Smoking was more prevalent in the fathers (76%) and hypercholesterolemia in the mothers (30%). In 183 siblings, 131 RF were observed (1 patient with the disease had a mean of 4.7 siblings). The prevalences of smoking, hypertension, hypercholesterolemia, and diabetes in the siblings were, respectively, 32%, 18%, 14%, and 9%. The incidence of RF was as follows: 72 (39%) siblings had 1 RF, 25 (14%) siblings had 2 RF, and 3 (2%) siblings had 3 RF. In parents and their offspring, smoking was moderately correlated (r=0.43; P=0.02) with CAD. CONCLUSION: Smoking habit of parents is passed on to offspring, and, in association with hypercholesterolemia, it was the major cause of early CAD in offspring. High prevalence of smoking in offspring shows the potential responsibility of parents in the incidence of the disease in offspring.

Characterization and distribution of Pogonomyrmex harvester ant lineages with genetic caste determination.

Genetic caste determination has been described in two populations of Pogonomyrmex harvester ants, each comprising a pair of interbreeding lineages. Queens mate with males of their own and of the alternate lineage and produce two types of diploid offspring, those fertilized by males of the queens' lineage which develop into queens and those fertilized by males of the other lineage which develop into workers. Each of the lineages has been shown to be itself of hybrid origin between the species Pogonomyrmex barbatus and Pogonomyrmex rugosus, which both have typical, environmentally determined caste differentiation. In a large scale genetic survey across 35 sites in Arizona, New Mexico and Texas, we found that genetic caste determination associated with pairs of interbreeding lineages occurred frequently (in 26 out of the 35 sites). Overall, we identified eight lineages with genetic caste determination that always co-occurred in the same complementary lineage pairs. Three of the four lineage pairs appear to have a common origin while their relationship with the fourth remains unclear. The level of genetic differentiation among these eight lineages was significantly higher than the differentiation between P. rugosus and P. barbatus, which questions the appropriate taxonomic status of these genetic lineages. In addition to being genetically isolated from one another, all lineages with genetic caste determination were genetically distinct from P. rugosus and P. barbatus, even when colonies of interbreeding lineages co-occurred with colonies of either putative parent at the same site. Such nearly complete reproductive isolation between the lineages and the species with environmental caste determination might prevent the genetic caste determination system to be swept away by gene flow.

Effect of type and timing of oil supplements to sows during pregnancy on the growth performance and endocrine profile of low and normal birth weight offspring

Eighty-eight multiparous sows were used to evaluate whether type and timing of oil supplementation during gestation influences the incidence of low birth weight (LBW). Sows were allocated (eight per treatment) commercial sow pellets (3 kg/d; control diet) or an experimental diet consisting of control diet plus 10 % extra energy in the form of excess pellets, palm oil, olive oil (OO), sunflower oil (SO) or fish oil; experimental diets were fed during either the first half (G1) or second half (G2) of gestation. Growth performance and endocrine profile of LBW ( < 1·09 kg) and normal birth weight (NBW; 1·46–1·64 kg) offspring were compared. Maternal dietary supplementation altered the distribution curve for piglet birth weight. SOG1 sows had a greater proportion of LBW piglets (P < 0·05), whilst it was reduced in the OOG1 group (P < 0·05). Growth rate of LBW piglets was lower compared with their NBW siblings (P < 0·05) when dietary supplementation was offered in G2 but were similar for G1. At birth, LBW offspring of supplemented animals possessed more fat compared with the control group (P < 0·05); LBW offspring of control animals exhibited a more rapid decline in fat free mass/kg prior to weaning. Plasma metabolites and insulin concentrations were influenced by maternal diet and birth weight. In conclusion, maternal dietary supplementation altered the distribution of piglet birth weights and improved the energy status of LBW piglets. Supplementation with MUFA during G1 reduced the incidence of LBW, whereas PUFA had the reverse effect.

Glycogen distribution in ameloblasts and odontoblasts of newborn rats of sialoadenectomized dams. Histochemical study

In order to get information about the distribution of glycogen in ameloblasts and odontoblasts, studies were made of newborn rats of sialoadenectomized dams and newborn rats of control dams. Rodent offspring were decapitated on the 1st, 3rd, 5th, 7th, and 9th days after birth. Their heads were fixed in 10% neutral formalin solution, decalcified in sodium citrate-formic acid and embedded in paraffin, and frontal sections were prepared. Sections 6 micrometers thick were stained by specific histochemical reactions to detect glycogen. Based on the results obtained, it was concluded that the amount of glycogen was lower in the cytoplasms of ameloblasts and odontoblasts of experimental animals when compared to controls.

Geographic distribution and parturition of mabuya arajara Rebouças-Spieker, 1981 (Squamata, sauria, scincidae) from Ceará, northeastern Brazil

Mabuya arajara Rebouças-Spieker, 1981 has been considered an endemic species from the southern of state of Ceará, restricted to the Deciduous Dry Forests in the slopes of Plateau of Araripe (Chapada do Araripe). Here, we present an updated distributional map for the species and demonstrate that its range is not restricted as formerly believed. In addition, we had an opportunity to observe a gravid female and we describe aspects regarding parturition and number of offspring for the species.

Maternal offspring behaviour in curraleiro pé duro naturalized cattle in brazil

The objective of the present study consisted of describing dam and calf suckling behaviour of Curraleiro Pé Duro cattle. In this study, 38 mother-offspring pairs and one mother-offspring-orphan trio were observed for 10 hours daily during three consecutive days spaced every four months over a period of one year. After identification,theanimalswereobserved under field conditions where calf posture and the number of sucklingepisodes(NS),meansucklingduration(MSD),total suckling duration per day (TSD) as well as natural weaning of these animals were recorded. The model assessed the effects of calf sex and age as well as feeding time. Suckling episodes (70.6%) had a duration of one to five minutes and the calf that suckled in the inverted parallel position had greater chances of success during suckling (99.5%); the younger animals had a shorter mean suckling duration (4.0±0.6 minutes) than the older ones (7.5±1.2 minutes) but they showed a higher number of suckling episodes (6.29±1.00 vs. 1.33±0.04 feeds in 10 hours for young and older calves). Only the factor age in the firstthree months was significant for NS,MSD,and TSD;males and females had similar suckling episode length and distribution. While these animals show some traits similar to other cattle breeds such as feeding their calves early in the morning and late in the afternoon, the dams spend large periods of the day away from their calves and suckling is more frequent but for shorter periods of time compared with other breeds. Other unique features such as allo-suckling and formation of day-long crèches are observed in this breed. © 2013 Sociedade Brasileira de Zootecnia;.

Effects of maternal diabetes on male offspring: high cell proliferation and increased activity of MMP-2 in the ventral prostate

This study presents a comprehensive view of the histological and functional status of the prostate of adult rat offspring of mothers subjected to gestational diabetes induced by alloxan. The ventral prostate of male adult offspring of diabetic (DP) or normal (CP) mothers was evaluated for collagen fibres, cell death, fibroblasts, smooth muscle cells, cell proliferation, matrix metalloproteinases (MMPs), androgen receptors (AR), transforming growth factor beta 1 (TGF beta-1), catalase and total antioxidant activity. The prostates of DP animals were lower in weight than those of the CP group. The DP group also exhibited hyperglycaemia and hypotestosteronemia, higher cell proliferation and AR expression, a reduction in alpha-actin (possibly interfering with the reproductive function of the prostate), and enhanced activity of MMP-2, although the absolute content of MMP-2 was lower in this group. These findings were associated with increased TGF beta-1 and decreased collagen distribution. The prostates of DP rats additionally exhibited reductions in catalase and total antioxidant activity. Thus, rats developing in a diabetic intrauterine environment have glycaemic and hormonal changes that impact on the structure and physiology of the prostate in adulthood. The increased AR expression possibly leads to elevated cell proliferation. Stromal remodelling was characterized by enhanced activity of MMP-2 and collagen degradation, even with increased TGF beta-1 activation. These changes associated with increased oxidative stress might interfere with tissue architecture and glandular homeostasis.

Provisioning Strategies of Antarctic Fur Seals and Chinstrap Penguins Produce Different Responses to Distribution of Common Prey and Habitat

Central-place foragers that must return to a breeding site to deliver food to offspring are faced with trade-offs between prey patch quality and distance from the colony. Among colonial animals, pinnipeds and seabirds may have different provisioning strategies, due to differences in their ability to travel and store energy. We compared the foraging areas of lactating Antarctic fur seals and chinstrap penguins breeding at Seal Island, Antarctica, to investigate whether they responded differently to the distribution of their prey (Antarctic krill and myctophid fish) and spatial heterogeneity in their habitat. Dense krill concentrations occurred in the shelf region near the colony. However, only brooding penguins, which are expected to be time-minimizers because they must return frequently with whole food for their chicks, foraged mainly in this proximal shelf region. Lactating fur seals and incubating penguins, which can make longer trips to increase energy gain per trip, and so are expected to be energy-maximizers, foraged in the more distant (>20 km from the island) slope and oceanic regions. The shelf region was characterized by more abundant, but lower-energy-content immature krill, whereas the slope and oceanic regions had less abundant but higher-energy-content gravid krill, as well as high-energy-content myctophids. Furthermore, krill in the shelf region undertook diurnal vertical migration, whereas those in the slope and oceanic regions stayed near the surface throughout the day, which may enhance the capture rate for visual predators. Therefore, we sug- gest that the energy-maximizers foraged in distant, but potentially more profitable feeding regions, while the time-minimizers foraged in closer, but potentially less profitable regions. Thus, time and energy constraints derived from different provisioning strategies may result in sympatric colonial predator species using different foraging areas, and as a result, some central-place foragers use sub- optimal foraging habitats, in terms of the quality or quantity of available prey.

Breeding system can affect the offspring sex ratio in Syrian hamsters

Nulliparous female Syrian hamsters were used to investigate the effect of two different breeding systems on the fertility of the female Syrian hamster. We hypothesized that females submitted to a harem system (HS) would deliver smaller and more female-biased litters than in a monogamic system. Ten female and 10 adult male hamsters housed individually (G1) were kept in a monogamic temporary breeding system, while 10 females and five males (G2) were submitted to HS with two females and a male permanently housed together since female weaning. Females from G1 and G2 delivered, respectively, 47 and 50 litters, and produced 364 (G1) and 383 (G2) weaned pups without any difference in litter size, mean weight of weaned pups and body condition of dams. Interparturition intervals were shorter and the percentage of male pups per litter was higher in the HS possibly as a result of different endocrine conditions provided by different breeding systems. Besides providing evidence that housing conditions can influence the sex of hamster offspring, our findings suggest a mechanism for the non-random distribution of male and female pups in hamster litters.