Hypothermia and rewarming induced by surface and He-O2 inhalate temperature control.

Hypothermia and rewarming were induced by a combination of temperature-controlled surface and inhalate methods in rabbits. To facilitate respiratory heat exchange, inhalate-respiratory tract temperature and humidity gradients and thermal conductivity were increased. In addition, the upper respiratory tract was bypassed by an endotracheal tube. To aid in maintaining satisfactory circulatory dynamics, hypercapnia and hypoxia were induced. The combined surface and inhalate method produced a markedly more effective rate of cooling than surface temperature-controlled method alone. Animals survived core temperatures as low as 20.9 degrees C with no complications. The noninvasive simplicity of this method suggests its potential applicability in many clinical situations.     

Changes in the rate of fermentation of maltose during propagation of industrial Baker's yeast

The rate of fermentation of glucose and maltose and the maltase activity of cellfree preparations of yeast were investigated during yeast propagation at the individual production stages. It was found that the yeast cells do not change much in their fermentation of glucose but that the level of the maltose-hydrolyzing enzyme undergoes changes, together with the character of the anaerobic fermentation of maltose, depending on the character of cultivation (batch or incremental feeding). After an initial decrease the maltose activity of cell-free preparations is maintained practically on the same level until the expedition phase is reached when it rapidly decreases to low values. The basis of the changes investigated is discussed together with their importance for yeast production technology.     

Über die mikrobicide Wirkung von organischen Säuren und ihren Kupfersalzen

Ohne Zusammenfassung     

Disintegration of Microorganisms and Preparation of Yeast Cell Walls in a New Type of Disintegrator

Microbial cells were disintegrated in a new type of rotary disintegrator with a disc stirrer by a combination of shear force layers, collisions, and rolling of glass beads which were brought into motion by the stirrer. The rate of disintegration at a given dry bed volume of Ballotini beads and a given volume of cell suspension is proportional to the peripheral velocity of the stirrer up to 18 m/sec. Horizontal arrangement of the stirrer increases the effectiveness about five times; 100% disintegration of yeast cells was achieved under optimal conditions within 72 sec at a concentration of 3.5g (dry weight)/100 ml of suspension, and within 96 sec at a concentration of 10.5g (dry weight)/100ml. At 17.5 g (dry weight)/100 ml, the stirrer began to slip. The cell walls of yeast were obtained at the desired degree of crushing and the course of purification was determined by infrared spectral analysis.     

Words matter: Reflections on language projects with chimpanzees and their implications

Beginning in the 1960s the first systematic projects dedicated to testing whether great apes could acquire some aspects of human language were conducted. The ape subjects demonstrated remarkable capacities to learn and use elements of either sign language or an artificial language. The results from research across several laboratories drew a mixture of excitement and skepticism, and critiques and debates have ensued since the earliest reports were published. This continues today. Terrace (2019, Nim: A chimpanzee who learned sign language. New York, NY: Columbia University Press) repeats many of the same points made decades earlier, and has added some additional critiques. That scientists hold different perspectives on what to conclude from ape language studies is expected. However, any conclusion one draws should be based upon available evidence, which we outline in this review. We also address the critiques offered by Terrace (2019), including the stance that apes cannot understand or use words. Focusing on symbol use by chimpanzees and bonobos we describe evidence that argues for understanding of words, including capacities for declarative communication and intersubjectivity found in these apes. We conclude that the many decades of research using a variety of symbol systems challenges the absolutist position that chimpanzees and bonobos cannot learn language or understand the concept of a word.     

Non-human primate token use shows possibilities but also limitations for establishing a form of currency

Non-human primates evaluate choices based on quantitative information and subjective valuation of options. Non-human primates can learn to value tokens as placeholders for primary rewards (such as food). With those tokens established as a potential form of ‘currency’, it is then possible to examine how they respond to opportunities to earn and use tokens in ways such as accumulating tokens or exchanging tokens with each other or with human experimenters to gain primary rewards. Sometimes, individuals make efficient and beneficial choices to obtain tokens and then exchange them at the right moments to gain optimal reward. Sometimes, they even accumulate such rewards through extended delay of gratification, or through other exchange-based interactions. Thus, non-human primates are capable of associating value to arbitrary tokens that may function as currency-like stimuli, but there also are strong limitations on how non-human primates can integrate such tokens into choice situations or use such tokens to fully ‘symbolize’ economic decision-making. These limitations are important to acknowledge when considering the evolutionary emergence of currency use in our species.This article is part of the theme issue ‘Existence and prevalence of economic behaviours among non-human primates’.     

Ultrastructure of the surface of multiple scars inSaccharomycodes ludwigii

The use of induced primuline fluorescence led to the discovery of a new type of yeast scars (multiple scars) in the generaKloeckera, Saccharomycodes, Nadsonia andHanseniaspora. The structure and ultrastructure of their surface was studied by electron microscopy, using carbon replicas and isolated cell walls.     

Delayed luminescence of Prorocentrum minimum under controlled conditions

Delayed luminescence (DL), also termed delayed fluorescence or delayed light emission, is the phenomenon of long-lived light emission by plants and cyanobacteria after being illuminated with light and put into darkness. Culture growth of three Prorocentrum minimum strains was studied with DL measurements. DL decay kinetics was measured from 1–60 s after a pulse of white light. The strains used were from the Adriatic Sea (PmK), from Chesapeake Bay, USA (D5), and from the Baltic Sea (BAL), cultured at salinity of 32, 16, and 8 (practical salinity scale), respectively. The strains differed in cell size and chlorophyll a content (PmK > D5 > BAL), as well as in DL parameters. The DL results were compared to standard measurements of culture density and carbon content (calculated from biovolumes). DL decay curves had a specific peak, which changed with culture growth and showed more similarities between the strains PmK and D5. The DL intensity increased with cell density and carbon content in a two-stage process, corresponding to the lag and exponential phases of growth. DL intensity was best correlated with carbon content irrespective of strain and is proposed as an estimate of biomass and for differentiating between lag and exponential phases of growth.