Asymptotic Behavior of Eigen’s Quasispecies Model

We study Eigen’s quasispecies model in the asymptotic regime where the length of the genotypes goes to \(\infty \) and the mutation probability goes to 0. A limiting infinite system of differential equations is obtained. We prove convergence of trajectories, as well as convergence of the equilibrium solutions. We give analogous results for a discrete-time version of Eigen’s model, which coincides with a model proposed by Moran.     

Animal Behavior: Who Will Croak Next?

A recent study with the predatory bat Trachops cirrhosus has shown the importance for this species of social learning about novel prey using auditory, rather than visual or olfactory, cues.     

Simulation of In Vitro Dissolution Behavior Using DDDPlus?

Dissolution testing is a performance test for many dosage forms including tablets and capsules. The objective of this study was to evaluate if computer simulations can predict the in vitro dissolution of two model drugs for which different dissolution data were available. Published montelukast sodium and glyburide dissolution data was used for the simulations. Different pharmacopeial and biorelevant buffers, volumes, and rotations speeds were evaluated. Additionally, a pH change protocol was evaluated using these buffers. DDDPlus™ 3, Beta version (Simulation Plus, Inc.), was used to simulate the in vitro dissolution data. The simulated data were compared with the in vitro data. A regression coefficient between predicted and observed data was used to assess the simulations. The statistical analysis of Montelukast sodium showed that there was a significant correlation between the in vitro release data and the predicted data for all cases except for one buffer. For glyburide, there was also a significant correlation between the experimental data and the predicted data using single pH conditions. Using the dynamic pH protocol, a correlation was significant for one biorelevant media. The simulations showed that both in vitro drug releases were sensitive to solubility effects which confirmed their BCS class II category. Computer simulations of the in vitro release using DDDPlus™ have the potential to estimate the in vivo dissolution at an early stage in the drug development process. This might be used to choose the most appropriate dissolution condition to establish IVIVC and to develop biorelevant in vitro performance tests to capture critical product attributes for quality control procedures in quality by design environments.KEY WORDS: biorelevant media, DDDPlus, dissolution testing, QbD, QC     

Is Play Behavior Sexually Dimorphic in Monogamous Species?

Monogamy is a relatively rare social system in mammals, occurring only in about 3% of mammalian species. Monogamous species are characterized by the formation of pair‐bonds, biparental care, and a very low level of sexual dimorphism. Whereas in most polygynous species males engage in more rough‐and‐tumble play than females, we predicted that males and females of monogamous species would have similar, or monomorphic, play behavior. In this study, we focused on two monogamous species: coppery titi monkeys (Callicebus cupreus) and prairie voles (Microtus ochrogaster). We documented the development of play behavior in both species, and quantified different types of play behavior. We did not find any sex differences in either species in the frequencies and types of play. However, we did find sex differences in the choice of play partner in titi monkeys: female offspring spent a higher proportion of time playing with their father, while male offspring played equally with their mother and father. It is possible that rough‐and‐tumble play behavior is monomorphic in many monogamous mammals, perhaps reflecting differences from polygynous species in the effects of exposure to early androgens or in the estrogen receptor distribution. However, more subtle differences in monomorphic play behavior, such as choice of partner, may still exist.     

Generation and Behavior Characterization of CaMKIIβ Knockout Mice

The calcium/calmodulin-dependent protein kinase II (CaMKII) is abundant in the brain, where it makes important contributions to synaptic organization and homeostasis, including playing an essential role in synaptic plasticity and memory. Four genes encode isoforms of CaMKII (α, β, δ, γ), with CaMKIIα and CaMKIIβ highly expressed in the brain. Decades of molecular and cellular research, as well as the use of a large number of CaMKIIα mutant mouse lines, have provided insight into the pivotal roles of CaMKIIα in brain plasticity and cognition. However, less is known about the CaMKIIβ isoform. We report the development and extensive behavioral and phenotypic characterization of a CaMKIIβ knockout (KO) mouse. The CaMKIIβ KO mouse was found to be smaller at weaning, with an altered body mass composition. The CaMKIIβ KO mouse showed ataxia, impaired forelimb grip strength, and deficits in the rotorod, balance beam and running wheel tasks. Interestingly, the CaMKIIβ KO mouse exhibited reduced anxiety in the elevated plus maze and open field tests. The CaMKIIβ KO mouse also showed cognitive impairment in the novel object recognition task. Our results provide a comprehensive behavioral characterization of mice deficient in the β isoform of CaMKII. The neurologic phenotypes and the construction of the genotype suggest the utility of this KO mouse strain for future studies of CaMKIIβ in brain structure, function and development.     

Animal Personality： Ecology,Behavior, and Evolution

The past decade has seen an extraordinary rise in the number of papers devoted to the study of consistent individual differences in behavior, termed variably as ＂personality＂, ＂behavioral types＂, ＂temperament＂, ＂cor related phenotypes＂, and/or ＂behavioral syndromes＂. In earnest, the acceleration of this field was initiated by a handful of reviews that focused on the ecological and evolutionary implications of personality,     

Is Altruistic Behavior Associated with Major Depression Onset?

Background

Previous cross-sectional study showed altruistic behaviors were harmful on major depression (MD). It is needed to investigate the impact of altruistic behaviors by its contents on the development of MD prospectively.

Methodology/Principal Findings

The National Survey of Midlife Development in the United States (MIDUS) in 1995–1996 and the MIDUS Psychological Experience Follow-Up study in 1998 were analyzed (weighted N = 563). Financial support of 10 or more dollars per month had a significant impact on the development of MD in comparison to no financial support (OR: 2.64, 95% CI: 1.05–6.62). Unpaid assistance and providing emotional support were not significantly associated with the development of MD in later life.

Conclusions/Significances

Those who provide financial contribution to individuals other than family members can be at risk of developing MD.     

How Does Male Ritual Behavior Vary Across the Lifespan?

Ritual behaviors of some form exist in every society known to anthropologists. Despite this universality, we have little understanding of how ritual behavior varies within populations or across the lifespan, nor the determinants of this variation. Here we test hypotheses derived from life history theory by using behavioral observations and oral interview data concerning participant variation in Fijian kava-drinking ceremonies. We predicted that substantial variation in the frequency and duration of participation would result from (1) trade-offs with reproduction and (2) the intrinsic status differences between ritual participants. We demonstrate that when controlling for household composition, men with young offspring participated less frequently and exhibited greater variance in their time spent at ceremonies than men without young children. However, men with a larger number of total dependents in their household participated more frequently than those with fewer. Moreover, we found that men’s ascribed rank, level of education, and reliance on wage labor all significantly predict their frequency of attendance. We also found that the number of dependents a man has in his household is positively correlated with total food production, and the amount of kava he cultivates. In general, these results suggest that ritual participation is part of an important strategy employed by Fijian men for both achieving status and developing social alliances. Variation in participation in kava ceremonies by Fijian men therefore reflects the constraints of their current life history condition and their inherited rank.     

Cities through the Prism of People’s Spending Behavior

Scientific studies of society increasingly rely on digital traces produced by various aspects of human activity. In this paper, we exploit a relatively unexplored source of data–anonymized records of bank card transactions collected in Spain by a big European bank, and propose a new classification scheme of cities based on the economic behavior of their residents. First, we study how individual spending behavior is qualitatively and quantitatively affected by various factors such as customer’s age, gender, and size of his/her home city. We show that, similar to other socioeconomic urban quantities, individual spending activity exhibits a statistically significant superlinear scaling with city size. With respect to the general trends, we quantify the distinctive signature of each city in terms of residents’ spending behavior, independently from the effects of scale and demographic heterogeneity. Based on the comparison of city signatures, we build a novel classification of cities across Spain in three categories. That classification exhibits a substantial stability over different city definitions and connects with a meaningful socioeconomic interpretation. Furthermore, it corresponds with the ability of cities to attract foreign visitors, which is a particularly remarkable finding given that the classification was based exclusively on the behavioral patterns of city residents. This highlights the far-reaching applicability of the presented classification approach and its ability to discover patterns that go beyond the quantities directly involved in it.     

“Spraying” Behavior During Queen Competition in Honey Bees

In honey bees (Apis mellifera), virgin queens may eject a liquid substance from their abdomens while they are engaged in fatal combat. We investigated the functional significance of spraying behavior by staging queen duels within colonies housed in observation hives. Spraying occurred in 39.7% of all interactions between rival queens and was recorded in 12 of 15 duels. Workers were highly attracted to the surfaces and individuals contaminated by spraying, forming tight clusters with hundreds of bees in which movement was severely restricted. One or both queens in a pair became immobilized by the workers in 37.5 and 29.2% of all spraying events, respectively, but the queens were never killed by the workers. Conversely, a mobile queen penetrated the worker aggregation and stung an immobilized queen in one-third of the observed bouts. Thus spraying may serve as a fighting tactic by virgin queens to increase their chances of winning by temporarily immobilizing their rivals.     

Diurnal Patterns and Correlates of Older Adults’ Sedentary Behavior

Introduction

Insights into the diurnal patterns of sedentary behavior and the identification of subgroups that are at increased risk for engaging in high levels of sedentary behavior are needed to inform potential interventions for reducing older adults’ sedentary time. Therefore, we examined the diurnal patterns and sociodemographic correlates of older adults’ sedentary behavior(s).

Methods

Stratified cluster sampling was used to recruit 508 non-institutionalized Belgian older adults (≥ 65 years). Morning, afternoon, evening and total sedentary time was assessed objectively using accelerometers. Specific sedentary behaviors, total sitting time and sociodemographic attributes were assessed using an interviewer-administered questionnaire.

Results

Participants self-reported a median of 475 (Q1-Q3 = 383–599) minutes/day of total sitting time and they accumulated a mean of 580 ± 98 minutes/day of accelerometer-derived sedentary time. Sedentary time was lowest during the morning and highest during the evening. Older participants were as sedentary as younger participants during the evening, but they were more sedentary during daytime. Compared to married participants, widowers were more sedentary during daytime. Younger participants (< 75 years), men and the higher educated were more likely to engage in (high levels of) sitting while driving a car and using the computer. Those with tertiary education viewed 29% and 22% minutes/day less television compared to those with primary or secondary education, respectively. Older participants accumulated 35 sedentary minutes/day more than did younger participants and men accumulated 32 sedentary minutes/day more than did women.

Conclusion

These findings highlight diurnal variations and potential opportunities to tailor approaches to reducing sedentary time for subgroups of the older adult population.     

行为遗传的双生子研究Twins Study on Behavior Genetics

本研究采用双生子法对人类几项行为 (简单的生理-心理动作、记忆、智能、个性) 进行了研究。以探讨上述行为中遗传与环境因素的不同影响。结果证明,上述行为均有不同程度的遗传倾向。但这种倾向随着行为的简单到复杂及与环境接触时间的增长有所不同。似乎有减弱的趋势。Abstract: In order to investigate genetic and inviromental factors influenceing human behavios. Authors studies some humen behaviors (Physical-psychological action, memory, intelligence, and personality) with twins method. The result shows that the above behaviors have different genetic prepotency. It seems to be decrease depending on times of contacting enviroment and from simple to complex behaviors.     

Characterizing the Freeze–Drying Behavior of Model Protein Formulations

The freeze–drying behavior of three model proteins, namely, lysozyme, BSA, and IgG, has been studied using a variety of techniques under two different primary drying conditions (shelf temperatures of −25°C and +25°C, respectively) in an amorphous formulation. Manometric temperature measurements were used to characterize product temperature (T _pr), sublimation rates, and product resistance (R _p) during primary drying. Biophysical techniques such as circular dichroism, fluorescence, and Fourier transform infrared spectroscopy were used to study protein conformation. Size exclusion chromatography was used to monitor the formation of high-molecular-weight species (HMWS) over time on storage, and cake morphology was studied using scanning electron microscopy. The differences in the freeze–drying behavior of the three proteins were more evident at higher protein concentrations, where the protein significantly influences the behavior of the formulation matrix. However, these differences were minimized in the aggressive mode and were insignificant at lower protein concentrations where excipients dominated the freeze–drying behavior. Differences in cake morphology were observed between the two drying conditions employed as well as between the three proteins studied. The stability and the protein structure, however, were equivalent for the protein cakes generated using the two different primary drying conditions.     

Influence of Micropatterning on Human Periodontal Ligament Cells’ Behavior

The periodontal ligament (PDL) is highly ordered connective tissue located between the alveolar bone and cementum. An aligned and organized architecture is required for its physiological function. We applied micropatterning technology to arrange PDL cells in 10- or 20-μm-wide extracellular protein patterns. Cell and nuclear morphology, cytoskeleton, proliferation, differentiation, and matrix metalloproteinase system expression were investigated. Micropatterning clearly elongated PDL cells with a low cell-shape index and low spreading area. The nucleus was also elongated as nuclear height increased, but the nuclear volume remained intact. The cytoskeleton was rearranged to form prominent bundles at cells’ peripheral regions. Moreover, proliferation was promoted by 10- and 20-μm micropatterning. Osteogenesis and adipogenesis were each inhibited, but micropatterning increased PDL cells’ stem cell markers. β-catenin was expelled to cytoplasm. YAP/TAZ nuclear localization and activity both decreased, which might indicate their role in micropatterning-regulated differentiation. Collagen Ι expression increased in micropatterned groups. It might be due to the decreased expression of matrix metalloproteinase-1, 2 and the tissue inhibitor of metalloproteinase-1 gene expression elevation in micropatterned groups. The findings of this study provide insight into the effects of a micropatterned surface on PDL cell behavior and may be applicable in periodontal tissue regeneration.     

Brain Switches Utilitarian Behavior: Does Gender Make the Difference?

Decision often implies a utilitarian choice based on personal gain, even at the expense of damaging others. Despite the social implications of utilitarian behavior, its neurophysiological bases remain largely unknown. To assess how the human brain controls utilitarian behavior, we delivered transcranial direct current stimulation (tDCS) over the ventral prefrontal cortex (VPC) and over the occipital cortex (OC) in 78 healthy subjects. Utilitarian judgment was assessed with the moral judgment task before and after tDCS. At baseline, females provided fewer utilitarian answers than males for personal moral dilemmas (p = .007). In males, VPC-tDCS failed to induce changes and in both genders OC-tDCS left utilitarian judgments unchanged. In females, cathodal VPC-tDCS tended to decrease whereas anodal VPC-tDCS significantly increased utilitarian responses (p = .005). In males and females, reaction times for utilitarian responses significantly decreased after cathodal (p<.001) but not after anodal (p = .735) VPC-tDCS. We conclude that ventral prefrontal tDCS interferes with utilitarian decisions, influencing the evaluation of the advantages and disadvantages of each option in both sexes, but does so more strongly in females. Whereas cathodal tDCS alters the time for utilitarian reasoning in both sexes, anodal stimulation interferes more incisively in women, modifying utilitarian reasoning and the possible consequent actions. The gender-related tDCS-induced changes suggest that the VPC differentially controls utilitarian reasoning in females and in males. The gender-specific functional organization of the brain areas involved in utilitarian behavior could be a correlate of the moral and social behavioral differences between the two sexes.     

Can Amphipod Behavior Help to Predict Chronic Toxicity of Sediments?

Amphipods are widely used in both acute and chronic (sub-lethal) sediment tests. Acute sediment tests provide relatively rapid results, but may fail to detect moderately toxic contaminants that are bound to the sediment, whereas chronic life-cycle tests are rarely performed as they are time consuming and expensive. Observations during chronic testing of oil-contaminated sediment suggested that there may be a link between the behavior of the marine amphipod Corophium volutator and reduction in growth rate. Behavior tests were performed with six individual amphipods per treatment using sediment spiked with weathered Forties oil with burrowing time, re-emergence from sediment, and activity prior to burrowing as endpoints. Further behavior tests were used to predict the chronic toxicity of sediments spiked with three crude oils each with a dominant unresolved complex mixture of hydrocarbons (UCM). The effect of sediment type on behavior was also investigated. The results suggested that although the behavior test could not be used alone as a viable alternative to sediment toxicity tests, it could prove useful as an adjunct to acute tests, and help select sediments that deserve further investigation.     

Systemic PPARγ Deletion Impairs Circadian Rhythms of Behavior and Metabolism

Compelling evidence from both human and animal studies suggests a physiological link between the circadian rhythm and metabolism but the underlying mechanism is still incompletely understood. We examined the role of PPARγ, a key regulator of energy metabolism, in the control of physiological and behavioral rhythms by analyzing two strains of whole-body PPARγ null mouse models. Systemic inactivation of PPARγ was generated constitutively by using Mox2-Cre mice (MoxCre/flox) or inducibly by using the tamoxifen system (EsrCre/flox/TM). Circadian variations in oxygen consumption, CO(2) production, food and water intake, locomotor activity, and cardiovascular parameters were all remarkably suppressed in MoxCre/flox mice. A similar phenotype was observed in EsrCre/flox/TM mice, accompanied by impaired rhythmicity of the canonical clock genes in adipose tissues and liver but not skeletal muscles or the kidney. PPARγ inactivation in isolated preadipocytes following exposure to tamoxifen led to a similar blockade of the rhythmicity of the clock gene expression. Together, these results support an essential role of PPARγ in the coordinated control of circadian clocks and metabolic pathways.