Human pair bonding

Each emotion is very complex and hence evolutionarily stable. It entails visceral adjustments, motoric responses, an affect, and extensive representation in the ancient subcortex. It is bound to be slow to evolve, hence Ekman s claim (1994, p. 16) that humans are unlikely to have evolved new emotions not found in other primates. Therefore, another useful criterion is presence in other primates. However, since every species has some unique characteristics, it is possible that some human emotions are absent from our primate relatives. For example, defecation may be purely reflexive in the arboreal primates but partly voluntary and hence emotional in our own species. Also, pair bonding is seen in humans but not chimpanzees. 

Research suggests a sexual dimorphism that AVP is important for pair bonding in male prairie voles, while OT is important for pair bonding in female prairie voles (Insel and Hulihan, 1995). Arginine-vasopressin is secreted during sexual arousal in humans. However, the exact role of the peptide in social bonding among humans remains unclear. 

Oxytocin involvement. The function of central OT in the human brain is not known. However, it has been suggested that OT released during sexual activity may influence selective pair bonds between partners, and when the hormone is released during childbirth and... 

It is remarkable that the work by Heitler and London that outlined for the first time a physically correct description of the chemical bond did not replace the Lewis picture of electron-pair bonding that was based on intuition rather than on elementary physics. One reason is the dramatically different appeal of the two approaches for human imagination of the chemical bond. The Lewis picture is simple to use and it proved as extremely powerful ordering scheme for molecular structures and reactivities. Chemists are generally happy with such models. The quantum theoretical description of interatomic interactions introduced the wave function as the central term for chemical bonding, which is in contrast an elusive object for human imagination, as evidenced by the intensive discussions about the meaning and the interpretation of P mainly in the physics community. 

Boric acid, B(OH) , is a white solid that melts at 171°C. It is toxic to bacteria and many insects as well as humans and has long been used as a mild antiseptic and pesticide. Because the boron atom in B(OH)3 has an incomplete octet, it can act as a Lewis acid and form a bond by accepting a lone pair of electrons from an H20 molecule acting as a Lewis base ... 

Base pair (bp) The four nucleotides in the DNA contain the bases adenine (A), guanine (G), cytosine (C), and thymine (T). Two bases (adenine and thymine or guanine and cytosine) are held together by weak bonds to form base pairs. The two strands of human DNA are held together in the shape of a double helix by those bonds between base pairs. For example, the complementary nucleic acid base sequence to G-T-A-C that forms a double-stranded structure with the matching bases is C-A-T-G. 

The Smectite Clays. The smectite-type clays are distinctive in that they expand and cause significant destruction to synthetic (human-made) structures. In this type of 2 1 clay, isomorphous substitution occurs in the aluminum sheet. If there is substitution of lower-oxidation-state metal such as magnesium, there will be an unsatisfied pair of bonding electrons in the interior of the crystal and there will be no noticeable change in the surface. Because the charge is in the interior of the crystal, its attraction for cations is diminished by distance. Thus, smectite crystals are not held together strongly by cations and are able to incorporate more water and ions between sheets when the environment is wet and less when it is dry. 

An unusual and unexpected feature of NOS is the presence of a Zn ion tetrahedrally coordinated to pairs of symmetry-related Cys residues along the dimer interface 81, 82) (Fig. 4). The original structure of the mouse iNOS dimer did not have the Zn but instead two symmetry-related Cys residues formed a disulfide bond 80). The structure of the human iNOS heme domain also had a disulfide, but the disulfide could readily be broken and Zn reconstituted to give a ZnS4 center indistinguishable from that found in eNOS (S3). An independent structure... 

What s DNA Deoxyribonucleic acid, the helical ladderlike chain of molecules that makes up genes. DNA consists of a sugar molecule called deoxyribose (it is somewhat related to glucose), a nitrogen-containing molecule called a base, and phosphate atoms bonded to the other two components. It is the sequence of base pairs (one base on each strand) in DNA that determines the end-product (e.g., protein). The human genome— the entire DNA content of a human being—contains approximately 3 billion base pairs. 

Both NER and BER forms of excision repair remove a great variety of defects, many of which are a result of oxidative damage.657 720 Most prominent among these is 7,8-dihydro-8-oxoguanine (8-OG), which is able to base pair with either cytosine (with normal Watson-Crick hydrogen bonding) or with adenine, which will yield a purine-purine mismatch and aC G —> A T transversion mutation (Eq. 27-24), a frequent mutation in human cancers.721 722... 

---