How to Analyze Communication Data from Laboratory Experiments Without Being a Machine Learning Specialist

Recently, the analysis of communication has gained attention in experimental research. One important question is whether certain types of communication affect decisions differently than others. In this regard, Houser & Xiao (2011) present an approach for the classification of natural language messages. The primary limitation of their approach is its limited applicability to large message datasets. Therefore, Penczynski (2019) extends the methodological instruments by applying a machine learning classifier to experimental communication data. This is accompanied by the problem of a dearth of machine learning knowledge among experimenters. Hence, this paper presents an approach that employs a publicly available machine learning text analysis application. This makes it possible to analyze larger datasets based on small training datasets classified beforehand by human evaluators. As a first step, I use primary communication data reported by Charness and Dufwenberg (2006) to generate both training and test datasets. Following this approach, I am able to substantially replicate the original classification results obtained by Charness and Dufwenberg. The second step again involves messages from Charness and Dufwenberg as training data, while I take messages from a related trust game published by Deck et al. (2013) as a test, dataset. Promisingly, I am also able to replicate the classification results obtained by the external evaluators, as reported by Deck et al. The findings suggest that machine learning can be used to analyze large message datasets, both if the artificial intelligence is trained with data from the very same experiment and if it is trained with message data from a comparable experiment.

546 PB 090 OPTIMIZING TOMATO YIELDS IN HIGH TUNNELS

Tomato production in high tunnels is very intensive, although relatively low-input. However, optimal use of every square foot of growing space is critical to maximizing returns. Utilizing the basket-weave trellis system, `Ultrasweet' tomatoes were grown in 4 (replicated), 14-foot-wide high tunnels in 4 rows per tunnel at 3.5 ft between rows. In-row spacing of 12, 18, and 24 inches was combined with removal of sideshoots below the first flower cluster: one or three shoots at 18 and 24-inch spacing and none or one at 12-inch spacing. The highest marketable yield per plant was 22 lbs at 24 inches and three sideshoots, while the lowest yield per plant was 13.9 lbs at 12 inches and no sideshoots. The highest yield per sq ft was 4.2 lbs at 12 inches and no sideshoots, while the lowest yield per sq ft was 2.5 lbs at 24 inches and one sideshoot. The yield response to spacing and side-shoot removal was inverse for lbs per plant and lbs per sq ft. There was no difference in fruit size among any of the treatments. In a comparable experiment under field conditions, the highest yield per plant was 12.6 lbs at 24 inches and one sideshoot; and the highest yield per sq ft was 2 lbs at 12 inches and one sideshoot. The percentage of marketable fruit in the tunnels and in the field was 93.0 and 85.1, respectively.

Necrobacillosis and immunity in mice

SUMMARYThe study arose from the recent finding that sub-lethal numbers of certain bacterial species greatly enhanced the infectivity of Fusobacterium necrophorum.A severe F. necrophorum infection in mice, cured with metronidazole, produced significant though slight resistance, which was demonstrable by challenge with a minute dose of F. necrophorum (< 20 organisms) suspended in a sub-lethal dose of Escherichia coli (300 × 10 organisms) to enhance fusobacterial infectivity. In an earlier comparable experiment, challenge with F. necrophorum alone, in necessarily large doses (≥3 × lO organisms), failed to demonstrate that a single cured fusobacterial infection gave rise to resistance; such an infection neither protected against the fatal necrobacillosis produced by challenge nor prolonged survival.A sub-lethal E. coli infection was also shown by challenge with a minute dose of F. necrophorum (< 10 organisms), suspended in a sub-lethal dose of E. coli (152 × 10 organisms), to produce significant though slight protection against necrobacillosis.The degrees of resistance demonstrated were too slight to give any encouragement to the prospect of an effective necrobacillosis vaccine.

The effect of anti-gonadotropic serum on the reproductive organs of the normal animal

It is now well established that anti-gonadotropic activity can be evoked in blood serum by the prolonged injection of animals with gonadotropic extracts, and such extracts from a variety of sources all appear to be effective. Thus extracts of human urine of pregnancy and pituitary extracts were used by Bachman, Collip, and Selye (1934); pituitary extracts by Fluhmann (1935, a , b ), and Eichbaum and Kindermann (1935); pregnant mare serum by Gustus, Meyer, and Dingle (1935), and urine from teratoma testis cases by Twombly and Ferguson (1934). The recent work of Twombly (1936) lends support to the view that the development of the anti-substances in sera in response to continued administration of hormone preparations is due to the introduction of heterologous proteins with antigenic properties. He has shown that when homologous extracts are injected, such as urine of pregnancy extracts to women, no anti-substances can be detected in the serum. Another relevant experiment was carried out by Du Shane, Levine Pfeiffer, and Witschi (1935) who united parabiotically two female rats, one hypophysectomized, the other ovariectomized. The gonadotropic hormone of the pituitary of the ovariectomized one sufficed to maintain the ovaries of the hypophysectomized one in a functional state for over a year without any sign of interference due to the production of antihormones. A similar view, based on a comparable experiment, has been put forward by Martins (1935). On the other hand, Gustus, Meyer, and Dingle (1935) prepared from serum of pregnant mares a protein-free extract of gonadotropic hormone which produced an anti-substance in the blood of monkeys, although the latter gave no precipitin reaction with the purified hormone.