Guaraná (Paullinia cupana) as a commercial crop in Brazilian Amazonia

Guaraná (Paullinia cupana) is a woody vine or sprawling shrub native to the central Amazon Basin. The seeds are commercially produced on some 6,000 ha in the state of Amazonas near Manaus. The principal article of commerce is an amber-colored, carbonated soft drink. It is also widely used as a high caffeine stimulant and in local medicines. The plant is monoecious and is damaged by a number of diseases, the most severe being anthracnose. Prospects are excellent for greatly expanded international markets.     

A POPULATION MEMETICS APPROACH TO CULTURAL EVOLUTION IN CHAFFINCH SONG: DIFFERENTIATION AMONG POPULATIONS

We investigated cultural evolution in populations of common chaffinches (Fringilla coelebs) in the Atlantic islands (Azores, Madeira, and Canaries) and neighboring continental regions (Morocco and Iberia) by employing a population-memetic approach. To quantify differentiation, we used the concept of a song meme, defined as a single syllable or a series of linked syllables capable of being transmitted. The levels of cultural differentiation are higher among the Canaries populations than among the Azorean ones, even though the islands are on average closer to each other geographically. This is likely the result of reduced levels of migration, lower population sizes, and bottlenecks (possibly during the colonization of these populations) in the Canaries; all these factors produce a smaller effective population size and therefore accentuate the effects of differentiation by random drift. Significant levels of among-population differentiation in the Azores, in spite of substantial levels of migration, attest to the differentiating effects of high mutation rates of memes, which allow the accumulation of new mutants in different populations before migration can disperse them throughout the entire region.     

Human pluripotent stem cell-derived extracellular vesicles: From now to the future

Extracellular vesicles (EVs) are nanometric particles that enclose cell-derived bioactive molecules in a lipid bilayer and serve as intercellular communication tools. Accordingly, in various biological contexts, EVs are reported to engage in immune modulation, senescence, and cell proliferation and differentiation. Therefore, EVs could be key elements for potential off-the-shelf cell-free therapy. Little has been studied regarding EVs derived from human pluripotent stem cells (hPSC-EVs), even though hPSCs offer good opportunities for induction of tissue regeneration and unlimited proliferative ability. In this review article, we provide an overview of studies using hPSC-EVs, focusing on identifying the conditions in which the cells are cultivated for the isolation of EVs, how they are characterized, and applications already demonstrated. The topics reported in this article highlight the incipient status of the studies in the field and the significance of hPSC-EVs’ prospective applications as PSC-derived cell-free therapy products.     

Historical biogeography and morphological differentiation ofStreptocephalus torvicornis (Waga) since the Würm III-glaciation

We argue that the Würm III glaciation eradicated possible European populations ofS. torvicornis, and that today, a reconquest of Europe takes place on two fronts.A western wave has reached the Pyrenees, an eastern one now occupies most of eastern and northern Europe. The western route probably started in the Maghreb, the eastern one in the Levant and the Ponto-Caspian. Animals in the west had to move north by crossing, at right angles, a series of east-west oriented river valleys and progressed slowly; animals in the east could move up river valleys extending north-east, and moved quickly. Italy was not occupied, becauseS.torvicornis is a warm stenotherm, and by the time the climate had warmed sufficiently for it to reach the southern shore of the mediterranean (ca 6000 BP), the gap with Italy was probably too large for a crossing. Cold-loving species (of the generaBranchipus, Chirocephalus) conversely, and could freely flow across the Central Mediterranean at low sea-levels (ca 12000 BP), and now occur in Italy (and the rest of Europe) as well as in Northern Africa.A prediction of our hypothesis is that the pioneer populations in Spain and Central Europe should have been isolated longest. Thisis tested and confirmed by their comparative morphology, and two subspecies,S. t. torvicornis andS. t. bucheti are reinstated.A gap across the Nile Valley where onlyS. rubricaudatus seems to occur, deserves further study.     

A family with a satellited Yq chromosome

Summary A large pedigree with a satellited Yq chromosome is described, Q, C, and NOR banding were performed. Family C proband suffers from a Klinefelter syndrome.     

Patterns of predation in a free-ranging troop of stumptail macaques (Macaca arctoides): Relations to the ecology II

Data on patterns of systematic and ocassional hunting of birds, mammals, reptiles, mollusks and insects by Stumptail macaques are reported for a period of ten months. Systematic hunting of water snails, terrestrial spiders, and land worms was conducted by all age classes, except infants, and both sexes. Of the occasional hunting of birds, large lizards, large frogs, and field mice, the adult females conducted 70%, the adult males 12%, the two year old females 12%, and the two year old males 6%. The differences between males and females were statistically significant (.05 confidence level). Females dominated the hunt and were more interested in meateating than the males. This contrasts strikingly with the data reported for baboons and chimpanzees in which the males dominate the hunt. Of all the prey hunted ocassionally, 76% was shared. The differences between shared and not sared prey were statistically significant (.05 confidence level). All age classes, including infants, participated in meat-sharing. Three types of meat-sharing are described: mother-offspring, hunter-close-friend, and piece-dropping. The prey was shared with genetic relatives, and with close and sistant friends in this order. Pearson’s correlation coeficients between rank of hunter and number of hunts and between rank of hunter and number of individuals with whom the prey was shared yielded +.866 and +.890 respectively. Meat-sharing seems to be similar to that observed for baboons but some differences exist between baboons and chimpanzees on the one hand and Stumptails on the other. Dominance relations in our Stumptails seem to act as the context determining the direction and the type of sharing. An increase in hunting activity during the study period is suggested to be the result of the prey’s migratory and breeding patterns, of environmental changes, and of the high activity scores and physiological states of the adult-females in the troop. Although not hunted, reactions to snakes, iguanas, scorpions, and gulls are also described. This work was supported by grants from Behavioral Sciences Foundation and by NSF Grant No. GB-42235.     

Inhibition of the polymerase chain reaction by sputum samples from tuberculosis patients after processing using a silica-guanidiniumthiocyanate DNA isolation procedure.

With the objective to evaluate PCR-mediated detection of Mycobacterium tuberculosis DNA as a diagnostic procedure for diagnosis of tuberculosis in individuals attending ambulatory services in Primary Health Units of the City Tuberculosis Program in Rio de Janeiro, Brazil, their sputum samples were collected and treated with a DNA extraction procedure using silica-guanidiniumthiocyanate. This procedure has been described to be highly efficient for extraction of different kind of nucleic acids from bacteria and clinical samples. Upon comparing PCR results with the number of acid-fast bacilli, no direct relation was observed between the number of bacilli present in the sample and PCR positivity. Part of the processed samples was therefore spiked with pure DNA of M. tuberculosis and inhibition of the PCR reaction was verified in 22 out of 36 (61%) of the samples, demonstrating that the extraction procedure as originally described should not be used for PCR analysis of sputum samples.     

Multiple Limit Cycles in a Gause Type Predator–Prey Model with Holling Type III Functional Response and Allee Effect on Prey

This work aims to examine the global behavior of a Gause type predator–prey model considering two aspects: (i) the functional response is Holling type III and, (ii) the prey growth is affected by the Allee effect. We prove the origin of the system is an attractor equilibrium point for all parameter values. It has also been shown that it is the ω-limit of a wide set of trajectories of the system, due to the existence of a separatrix curve determined by the stable manifold of the equilibrium point (m,0), which is associated to the Allee effect on prey. When a weak Allee effect on the prey is assumed, an important result is obtained, involving the existence of two limit cycles surrounding a unique positive equilibrium point: the innermost cycle is unstable and the outermost stable. This property, not yet reported in models considering a sigmoid functional response, is an important aspect for ecologists to acknowledge as regards the kind of tristability shown here: (1) the origin; (2) an interior equilibrium; and (3) a limit cycle of large amplitude. These models have undoubtedly been rather sensitive to disturbances and require careful management in applied conservation and renewable resource contexts.