Comparative Functional and Numeric Response of Two Coccinellids (Coccinella septempunctata and Cheilomenes sexmaculata) Preying Cowpea Aphid (Aphis craccivora)

Background: The cowpea aphid, Aphis craccivora Koch (Hemiptera: Aphididae), a plant lice known to commonly attack plants that causes loss by sucking sap from phloem and act as vector for viruses. The aphidophagous coccinellids are efficient in controlling the pestiferous population of aphids. The two coccinellid Coccinella septempunctata and Cheilomenes sexmaculata are efficient in predation of cowpea aphid, Aphis craccivora in southern Rajasthan. The present study determined the response of prey consumption at different prey densities. Methods: To compute the functional and numeric response of the lady bird beetle on cowpea aphid, experiment was conducted in vitro by using cowpea potted plant in caged conditions at Department of Entomology, Rajasthan College of Agriculture during 2019-20. The cowpea pea plants were sown in small pots and were placed in aluminium insect cages having 15 cm × 15 cm × 15 cm size. The predatory potential of coccinellid grubs and adults were evaluated at six different prey densities (aphids per arena): 25, 50, 75, 100, 125, 150 and 200 with 5 replications. Result: The grub and adults of C. septempunctata consumed more prey as compared to C. sexmaculata. Both the coccinellid showed Type II functional response when functional curve was plotted. The linear regression method suggested that C. septempunctata required less time to act upon prey as compared to C. sexmaculata. The C. septempunctata also showed more numeric response in terms of ECI [conversion efficiency of prey consumption (ECI) into biomass (egg)] at different prey densities. The fecundity in both the cases increased with the increased prey densities that eventually decreased after reaching the maximum egg laying capacity at prey density of 125 aphids. In all the cases it was found that consumption rate of predaceous beetle increased with increasing aphid population.

How Well Do Interviewers Record Responses to Numeric, Interviewer Field-code, and Open-ended Narrative Questions in Telephone Surveys?

Telephone survey interviewers need to be able to accurately record answers to questions. While straightforward for closed questions, this task can be complicated for open questions. We examine interviewer recording accuracy rates from a national landline random digit dial telephone survey. We find that accuracy rates are over 90% for numeric response and interviewer-code, single-response items but are astonishingly low (49%) for a multiple-answer, nominal, interviewer-code item. Accuracy rates for narrative open questions were around 90% for themes but only about 70% for themes and elaborations. Interviewer behaviors (e.g., probing, feedback) are generally associated with lower accuracy rates. Implications for questionnaire design, interviewer training, and coding procedures are discussed.

The demography of words: the global decline in non-numeric fertility preferences, 1993-2011

This paper examines the decline in non-numeric responses to questions about fertility preferences among women in the developing world. These types of response—such as ‘don't know’ or ‘it's up to God’—have often been interpreted through the lens of fertility transition theory as an indication that reproduction has not yet entered women's ‘calculus of conscious choice’ (Coale 1973, p. 65). However, this has yet to be investigated cross-nationally and over time. Using 19 years of data from 32 countries, we find that non-numeric fertility preferences decline most substantially in the early stages of a country’s fertility transition. Using country-specific and multilevel models, we explore the individual- and contextual-level characteristics associated with women’s likelihood of providing a non-numeric response to questions about their fertility preferences. Non-numeric fertility preferences are influenced by a host of social factors, with educational attainment and knowledge of contraception being the most robust and consistent predictors.

Effective Sampling From Social Media Sites and Search Engines for Web Surveys

With proliferation of web surveys, the relative affordability of recruitment, and increasing nonresponse in other survey modes, nonprobability methods are increasingly being considered by researchers and government offices alike. However, research needs to more fully understand how the demographic characteristics of respondents may depend heavily on the source of sample, mode of recruitment, and context of the survey experience. As a first step in exploring the potential implications of recruitment source on response quality, we use data from a web survey fielded in 2013 to compare data quality indicators in survey data from the two recruitment platforms (Google and Facebook advertisements). In so doing, taking into account demographic differences that may arise from various steps in the recruitment process, we explore the effect of demographics, device and technology usage, incentives, and recruitment platform on data quality and response strategy. Our results show differences between platforms in comparability to national benchmarks, breakoffs, completion time, nonsubstantive answers, and numeric response strategies. Importantly, some variation in substantive responses was explained by demographic differences related to mobile device usage, which varied by recruitment platform. With the use of nonprobability samples on the rise, future work should build from these results to more directly assess the role of recruitment source in data quality.

Health Literacy Predicts Discrepancies Between Traditional Written Patient Assessments and Verbally Administered Assessments in Rheumatoid Arthritis

Objective.Patient assessments of disease activity (PtGA) and general health (GH) measured by visual analog scale (VAS) are widely used in rheumatoid arthritis (RA) clinical practice and research. These require comprehension of the question’s wording and translation of disease activity onto a written VAS, which is problematic for patients with limited health literacy (HL) or difficulty completing forms. This study’s objective was to validate verbally administered versions of patient assessments and identify factors that might explain discrepancies between verbal and written measures.Methods.We enrolled patients with RA at the Denver Health rheumatology clinic (n = 300). Subjects were randomized to complete the traditional written PtGA and GH and one of the verbal assessments. Subjects provided a verbal numeric response after reading the question, having the question read to them in person, or hearing the question over the phone. Spearman and Lin correlations comparing written and verbal assessments were determined. Multivariate logistic regression was performed to explain any discrepancies.Results.The instruments administered verbally in-person showed good, but not excellent, correlation with traditional written VAS forms (Spearman coefficients 0.59 to 0.70; p < 0.001 for all correlations). Twenty-three percent of subjects were unable to complete 1 of the written VAS assessments without assistance. HL predicted missing written data and discrepancies between verbal and written assessments (p < 0.05 for all correlations).Conclusion.Providers should use verbal versions of PtGA and GH with caution while caring for patients unable to complete traditional written version. Limited HL is widely prevalent and a barrier to obtaining patient-oriented data.

Conditions for caribou persistence in the wolf-elk-caribou systems of the Canadian Rockies

Woodland caribou populations are considered threatened in Alberta and have declined in the Canadian Rocky Mountain National Parks of Banff and Jasper despite protection from factors causing caribou populations to decline outside of parks. Recent research emphasizes the importance of the numeric response of wolves to moose in moose-caribou-wolf systems to caribou persistence. Moose are rare in the Canadian Rockies, where the dominant ungulate prey for wolves is elk. Few studies have explored wolf-elk dynamics and none have examined implications for caribou. We used data collected in Banff to estimate the numeric response of wolves to elk from 1985 to 2005. Because no caribou kill-rate data exist for the Rockies, we explore the consequences of a range of hypothetical kill-rates based on kill-rates of alternate prey collected from 1985 to 2000 in Banff. We then multiplied the numeric response of wolves by the estimated caribou kill-rates to estimate the wolf predation response on caribou as a function of elk density. Caribou predation rates were inversely density dependent because wolf numbers depend on prey species besides caribou in multiple prey species systems. We then combined this simple wolf-elk-caribou model with observed demographic and population estimates for Banff and Jasper caribou from 2003-2004 and solved for the critical kill-rate thresholds above which caribou populations would decline. Using these critical kill-rate thresholds, Jasper caribou are likely to persist when wolf densities are below 2.1 - 4.3 wolves/1000km2 and/or when elk densities are below 0.015- 0.033 elk/km2. Thresholds for Banff caribou persistence are much lower because of inverse density dependence. Future research is needed on some of the necessary assumptions underlying our modeling including multi-prey wolf numeric responses, wolf kill-rates of caribou, caribou mortality by other predators, and spatial aspects of wolf-elk-caribou dynamics.

What Constitutes Adequate Oxygenation?

In an attempt to avoid the substantial risks of pulmonary injury associated with the use of high ventilator pressures and high oxygen concentrations, physicians often ask such questions as "What is the optimal Pao2?" and "What treatment should be used to achieve an optimal Pao2?" Although the intent to minimize secondary, ventilator-induced lung injury is laudable, any attempt to provide a fixed numeric response to this query is misguided not only because the oxygen requirements and clinical circumstances of our patients vary, but because the Pao2 is a particularly poor indicator of these needs. An example is the large full-term neonate admitted to a newborn intensive care unit from the delivery room with obvious tachypnea and an arterial Po2 of 60 mm Hg in room air. Is this Pao2 acceptable? A more appropriate question may be whether the infant's "oxygenation" is adequate. But what is "oxygenation"? If by this vaguely applied term we mean the partial pressure of oxygen in the arterial blood, and if we define the acceptable limits for this parameter as being between 50 and 80 mm Hg, as is often done, then the answer must clearly be in the affirmative. If, on the other hand, we take oxygenation to mean the balance between the rate of oxygen delivery to the tissues and their rate of oxygen consumption, then we must admit that we cannot know on the basis of the information provided by the Pao2 alone. Oxygen delivery is determined by the concentration o hemoglobin in the blood, its oxygen saturation, the rate at which this blood is circulated to the tissues (generally, the cardiac output), and the efficiency with which the oxygen is "unloaded" from hemoglobin to the tissues.

Confusion Matrix Analysis for Form Perception

The Constant-Ratio Rule (CRR), an empirical technique for analysis of confusion matrices, was developed for use in predicting intelligibility of speech syllables. This study investigated the validity of the rule when applied to the data from experiments on visual form perception. English letters and simple geometric figures were tachistoscopically presented in the center of a viewing field. Response proportions for subsets of this master set of stimuli were predicted by CRR. Results indicated that the rule (1) accurately predicted numeric response proportions for subsets of stimuli when experimental conditions were similar and (2) predicted ordinally accurate data when experimental conditions varied within the limit which might be encountered in “operational situations.” These results, as well as arithmetic factors which can result in errors in prediction, are discussed.