Hominid divergence and speech evolution

Hominids evolved from a population which diverged from other hominoids during the Mio-Pliocene. This population was perhaps forced by ecological conditions and competitive exclusion to rely more on tools, gathering, hunting, vocal communication and memory, under whose mutually positively reinforcing effects the hominids diverged. The ape ancestors may have been forced into the forests (or they may have forced hominids onto the savanna), while hominids adapted to a plains, hunting econiche.Speech was selected for because verbal symbols served as retrieval cues for a large number of complex concepts and were transmissible, and thus could be used to influence food-getting and other behavior by the social group.Speech is dependent on three inherited entities: (1) anatomical and neurological adaptations which allow vocalization of a wide range of phonemes in rapid succession and which allow for (2) duality of patterning, thereby promoting a large number of words, and (3) encoding, which greatly increases the rate at which verbal information transfer can occur. Speech may have evolved through small hominid groups using progressively more phonemes in an increasingly blended manner, with encoding subsequently being selected for. Neandertals apparently could not encode speech and could speak only a restricted range of phonemes. Their expanded cranial capacity may have been selected for to store ambiguous and slowly transmitted verbal data.     

Carbonic acid production and the role of carbonic anhydrase in decarboxylation in brain

Sudden oxygenation of a thin film of rat brain homogenate, suspended between the surface of a glass pH-sensitive electrode and a gas-permeable membrane, is accompanied by a fall in pH, which is greater when carbonic anhydrase is inhibited. The result suggests that oxidative decarboxylation yields carbonic acid (HCO(3)- and H(+)), which dissociates to form molecular carbon dioxide. Brain carbonic anhydrase facilitates the formation of carbon dioxide from the decarboxylation products.     

Relationship of Aflatoxicosis to Salmonella gallinarum Infections of Chickens

Aflatoxicosis and Salmonella gallinarum exert their effects on the body weight and mortality of chickens without any interaction.     

Combination Chemotherapy using L-Asparaginase,Daunorubicin, and Cytosine Arabinoside in Adults with Acute Myelogenous Leukaemia

Cytosine arabinoside and daunorubicin used in an intensive intermittent regimen have been shown to be an effective combination for the induction of complete remissions in 14 out of 23 adult patients with acute myelogenous leukaemia. This gives an overall complete remission rate of 60%. A further patient had a good partial remission. The addition of L-asparaginase to the regimen has not increased the incidence of remission and there were more side effects in the L-asparaginasetreated group. Of the 10 patients treated with L-asparaginase in addition to cytosine arabinoside and daunorubicin, five achieved a complete remission. Of the 13 patients treated with cytosine arabinoside and daunorubicin without L-asparaginase, nine achieved a complete remission and one a good partial remission.     

Observations on the vacuolar structure of the human syncytiotrophoblast

Summary The literature on the vacuolar structure of the human syncytiotrophoblast is briefly reviewed. Personal observations based on light and electron microscopic investigations are described and illustrated. The nature of the different kinds of syncytial vacuolation is discussed. In particular dilated vacuoles, which may be very large indeed, receive special attention; situated adjacent to the syncytial nuclei they have been called juxtanuclear vacuoles. They are directly continuous with the perinuclear spaces, and often receive tubular communications from the endoplasmic reticular system. The possible functional role of the syncytial vacuolar system is discussed in the light of the authors' findings and the related literature.Dedicated to Professor Dr. Kurt Goerttler on the occasion of his seventieth birthday.     

Murine Toxicity of Agrobacterium tumefaciens

Eleven strains of the crown gall organism, Agrobacterium tumefaciens, tested by intraperitoneal injection into mice, were lethal within 48 hr. Five other species had some lethal strains. The lethal effect of A. tumefaciens appeared to be the result of a toxic rather than an infectious process, since histopathological anomalies were not found in mice injected with live cultures and since heat-killed cultures were lethal. The murine toxin disappeared when A. tumefaciens was grown at 36 C and reappeared when the organism was subsequently incubated below 30 C. The murine toxin itself was not inactivated by exposure to 100 C for 30 min. The toxin was associated with the cells and was not excreted into the medium. Centrifugal fractionation revealed that the toxin was associated with the smaller cells in 3-day stationary-phase cultures. These data suggested a possible relationship between toxin production and the production of the agents responsible for the initiation of plant tumors.