Stem cells of Hydra magnipapillata can differentiate into somatic cells and germ line cells

We investigated whether all stem cells of Hydra can differentiate both somatic cells and gametes or if a separate germ line exists in these phylogenetically old organisms. The differentiation potential of single stem cells was analyzed by applying a statistical cloning procedure. All stem cell clones were found to differentiate somatic cells. No clone was found to contain stem cells which do not differentiate. Most of the clones could be induced to form gametes. No clone was found that produced gametes only. The results indicate that stem cells are multipotent in the sense that individual stem cells can differentiate into somatic cells as well as germ line cells

Modular structuring in Art and Design; a comparison between British and American degree courses

Higher Education in Britain is witnessing an increasing interest in the modular structuring of courses, with several institutions already committed to 'modularity' or 'unisation'. Birmingham Polytechnic has now converted most of its first degree provision to a unit-based structure with the aim of 'creating greater flexibility in courses so that they may more easily respond to the changing needs of students and society', and to introduce 'different pathways from combinations of existing, modified, and new units dependant upon perceived educational need and viability'

Conflict in Married Couples: Personality Predictors of Anger and Upset

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/91371/1/j.1467-6494.1991.tb00926.x.pd

Strategies of Human Mating

Modern humans have inherited the mating strategies that led to the success of their ancestors. These strategies include long-term mating, short-term mating, extra-pair mating, mate poaching, and mate guarding. This article presents empirical evidence supporting evolution-based hypotheses about the complexities of these mating strategies. Since men and women historically confronted different adaptive problems in the mating domain, the sexes differ profoundly in evolved strategic solutions. These differences include possessing different mate preferences, different desires for short-term mating, and differences in the triggers that evoke sexual jealousy. The study of human mating is one of the “success stories” of evolutionary psychology

Interstitial Stem Cell Proliferation in Hydra: Evidence for Strain-Specific Regulatory Signals

We have examined the growth behavior of small numbers of interstitial stem cells transplanted into tissue of genetically unrelated strains of Hydra magnipapillata. We show that such stem cells, which are at low density following transplantation, proliferate more rapidly than the stem cells of the host, which are at normal density. The rapid proliferation is similar to the proliferation rate of stem cells transplanted into interstitial cell free tissue. The results suggest that stem cells transplanted into heterotypic tissue are unable to “sense” the presence of host stem cells and to adopt their growth rate to that of the surrounding cells. Thus, the feedback signal which negatively regulates stem cell growth as a function of stem cell density must be strain specific

Lewis Acid Enhancement of Proton Induced CO_2 Cleavage: Bond Weakening and Ligand Residence Time Effects

Though Lewis acids (LAs) have been shown to have profound effects on carbon dioxide (CO_2) reduction catalysis, the underlying cause of the improved reactivity remains unclear. Herein, we report a well-defined molecular system for probing the role of LA additives in the reduction of CO_2 to carbon monoxide (CO) and water. Mo(0) CO_2 complex (2) forms adducts with a series of LAs, demonstrating CO_2 activation that correlates linearly with the strength of the LA. Protons induce C–O cleavage of these LA adducts, in contrast to the CO_2 displacement primarily observed in the absence of LA. CO_2 cleavage shows dependence on both bond activation and the residence time of the bound small molecule, demonstrating the influence of both kinetic and thermodynamic factors on promoting productive CO_2 reduction chemistry

Can I have blood tests to check everything is alright?

Patients often request a general check-up with blood tests. In the UK these are often referred to as an MOT, in allusion to the annual motor vehicle check. Some patients may, however, have unrealistic expectations of medical tests1 and underestimate their potential harms. While agreeing to some blood tests can be an easy way out for a busy clinician, it can expose patients to the harms of over-testing and produce extra workload downstream. We provide a framework for navigating these requests constructively, some elements of which are feasible within a 10 minute consultation

Sexual Jealousy

Sexual jealousy is a basic emotion. Although it lacks a distinctive facial expression and is unlikely to solve problems of survival, it evolved because it solves adaptive problems of mating. Some adaptive functions are similar in men and women at one level of abstraction, such as warding off potential mate poachers and deterring relationship defection. Other functions are sex-differentiated, such as increasing paternity probability for men and monopolizing a mate\u27s economic commitments for women. Dozens of studies have documented sex-differentiated design features of jealousy: The relative upset about sexual and emotional aspects of infidelity; processing speed and memorial recall of sexual and emotional infidelity cues; physiological distress to sexual and emotional infidelity cues; qualities of same-sex rivals that evoke jealousy, such as superior job prospects versus greater physical attractiveness; triggers of mate retention tactics; jealous interrogations following the discovery of infidelity; and whether an infidelity produces forgiveness or breakup. Although showing all the hallmarks of evolved functionality, sexual jealousy also leads to tremendous destruction, from humiliation to homicide. By these scientific theoretical and empirical criteria, sexual jealousy is properly considered not only "basic" but also "one of the most important emotions"

Do women have evolved mate preferences for men with resources? : A reply to Smuts

Research by more than 50 scientists studying more than 10,000 individuals inhabiting 33 countries, six continents, and five islands supports the hypothesis that women have evolved mate preferences for men who show cues of resource possession or resource acquisition potential. Smuts' (1991) apparent view that these species-typical preferences do not exist is contravened by the scientific evidence. Repeated assertions that "behaviors depends on context" do not illuminate our understanding in the absence of specifying which behaviors, which contexts, and which evolved mechanisms are activated by the relevant contextual input. Progress in the study of evolution and human behavior depends on using key terms in consensually defined rather than idiosyncratic ways, on distinguishing evolved psychological mechanisms from manifest behavior, and on giving greater weight to cumulative scientific evidence than to subjective impressions.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/29156/1/0000200.pd