Multivariate Analysis for Animal Selection in Experimental Research

Background: Several researchers seek methods for the selection of homogeneous groups of animals in experimental studies, a fact justified because homogeneity is an indispensable prerequisite for casualization of treatments. The lack of robust methods that comply with statistical and biological principles is the reason why researchers use empirical or subjective methods, influencing their results. Objective: To develop a multivariate statistical model for the selection of a homogeneous group of animals for experimental research and to elaborate a computational package to use it. Methods: The set of echocardiographic data of 115 male Wistar rats with supravalvular aortic stenosis (AoS) was used as an example of model development. Initially, the data were standardized, and became dimensionless. Then, the variance matrix of the set was submitted to principal components analysis (PCA), aiming at reducing the parametric space and at retaining the relevant variability. That technique established a new Cartesian system into which the animals were allocated, and finally the confidence region (ellipsoid) was built for the profile of the animals’ homogeneous responses. The animals located inside the ellipsoid were considered as belonging to the homogeneous batch; those outside the ellipsoid were considered spurious. Results: The PCA established eight descriptive axes that represented the accumulated variance of the data set in 88.71%. The allocation of the animals in the new system and the construction of the confidence region revealed six spurious animals as compared to the homogeneous batch of 109 animals. Conclusion: The biometric criterion presented proved to be effective, because it considers the animal as a whole, analyzing jointly all parameters measured, in addition to having a small discard rate.

A determinação dos números de indivíduos mínimos necessários na experimentação genética

The main object of the present paper consists in giving formulas and methods which enable us to determine the minimum number of repetitions or of individuals necessary to garantee some extent the success of an experiment. The theoretical basis of all processes consists essentially in the following. Knowing the frequency of the desired p and of the non desired ovents q we may calculate the frequency of all possi- ble combinations, to be expected in n repetitions, by expanding the binomium (p-+q)n. Determining which of these combinations we want to avoid we calculate their total frequency, selecting the value of the exponent n of the binomium in such a way that this total frequency is equal or smaller than the accepted limit of precision n/pª{ 1/n1 (q/p)n + 1/(n-1)| (q/p)n-1 + 1/ 2!(n-2)| (q/p)n-2 + 1/3(n-3) (q/p)n-3... < Plim - -(1b) There does not exist an absolute limit of precision since its value depends not only upon psychological factors in our judgement, but is at the same sime a function of the number of repetitions For this reasen y have proposed (1,56) two relative values, one equal to 1-5n as the lowest value of probability and the other equal to 1-10n as the highest value of improbability, leaving between them what may be called the "region of doubt However these formulas cannot be applied in our case since this number n is just the unknown quantity. Thus we have to use, instead of the more exact values of these two formulas, the conventional limits of P.lim equal to 0,05 (Precision 5%), equal to 0,01 (Precision 1%, and to 0,001 (Precision P, 1%). The binominal formula as explained above (cf. formula 1, pg. 85), however is of rather limited applicability owing to the excessive calculus necessary, and we have thus to procure approximations as substitutes. We may use, without loss of precision, the following approximations: a) The normal or Gaussean distribution when the expected frequency p has any value between 0,1 and 0,9, and when n is at least superior to ten. b) The Poisson distribution when the expected frequecy p is smaller than 0,1. Tables V to VII show for some special cases that these approximations are very satisfactory. The praticai solution of the following problems, stated in the introduction can now be given: A) What is the minimum number of repititions necessary in order to avoid that any one of a treatments, varieties etc. may be accidentally always the best, on the best and second best, or the first, second, and third best or finally one of the n beat treatments, varieties etc. Using the first term of the binomium, we have the following equation for n: n = log Riim / log (m:) = log Riim / log.m - log a --------------(5) B) What is the minimun number of individuals necessary in 01der that a ceratin type, expected with the frequency p, may appaer at least in one, two, three or a=m+1 individuals. 1) For p between 0,1 and 0,9 and using the Gaussean approximation we have: on - ó. p (1-p) n - a -1.m b= δ. 1-p /p e c = m/p } -------------------(7) n = b + b² + 4 c/ 2 n´ = 1/p n cor = n + n' ---------- (8) We have to use the correction n' when p has a value between 0,25 and 0,75. The greek letters delta represents in the present esse the unilateral limits of the Gaussean distribution for the three conventional limits of precision : 1,64; 2,33; and 3,09 respectively. h we are only interested in having at least one individual, and m becomes equal to zero, the formula reduces to : c= m/p o para a = 1 a = { b + b²}² = b² = δ2 1- p /p }-----------------(9) n = 1/p n (cor) = n + n´ 2) If p is smaller than 0,1 we may use table 1 in order to find the mean m of a Poisson distribution and determine. n = m: p C) Which is the minimun number of individuals necessary for distinguishing two frequencies p1 and p2? 1) When pl and p2 are values between 0,1 and 0,9 we have: n = { δ p1 ( 1-pi) + p2) / p2 (1 - p2) n= 1/p1-p2 }------------ (13) n (cor) We have again to use the unilateral limits of the Gaussean distribution. The correction n' should be used if at least one of the valors pl or p2 has a value between 0,25 and 0,75. A more complicated formula may be used in cases where whe want to increase the precision : n (p1 - p2) δ { p1 (1- p2 ) / n= m δ = δ p1 ( 1 - p1) + p2 ( 1 - p2) c= m / p1 - p2 n = { b2 + 4 4 c }2 }--------- (14) n = 1/ p1 - p2 2) When both pl and p2 are smaller than 0,1 we determine the quocient (pl-r-p2) and procure the corresponding number m2 of a Poisson distribution in table 2. The value n is found by the equation : n = mg /p2 ------------- (15) D) What is the minimun number necessary for distinguishing three or more frequencies, p2 p1 p3. If the frequecies pl p2 p3 are values between 0,1 e 0,9 we have to solve the individual equations and sue the higest value of n thus determined : n 1.2 = {δ p1 (1 - p1) / p1 - p2 }² = Fiim n 1.2 = { δ p1 ( 1 - p1) + p1 ( 1 - p1) }² } -- (16) Delta represents now the bilateral limits of the : Gaussean distrioution : 1,96-2,58-3,29. 2) No table was prepared for the relatively rare cases of a comparison of threes or more frequencies below 0,1 and in such cases extremely high numbers would be required. E) A process is given which serves to solve two problemr of informatory nature : a) if a special type appears in n individuals with a frequency p(obs), what may be the corresponding ideal value of p(esp), or; b) if we study samples of n in diviuals and expect a certain type with a frequency p(esp) what may be the extreme limits of p(obs) in individual farmlies ? I.) If we are dealing with values between 0,1 and 0,9 we may use table 3. To solve the first question we select the respective horizontal line for p(obs) and determine which column corresponds to our value of n and find the respective value of p(esp) by interpolating between columns. In order to solve the second problem we start with the respective column for p(esp) and find the horizontal line for the given value of n either diretly or by approximation and by interpolation. 2) For frequencies smaller than 0,1 we have to use table 4 and transform the fractions p(esp) and p(obs) in numbers of Poisson series by multiplication with n. Tn order to solve the first broblem, we verify in which line the lower Poisson limit is equal to m(obs) and transform the corresponding value of m into frequecy p(esp) by dividing through n. The observed frequency may thus be a chance deviate of any value between 0,0... and the values given by dividing the value of m in the table by n. In the second case we transform first the expectation p(esp) into a value of m and procure in the horizontal line, corresponding to m(esp) the extreme values om m which than must be transformed, by dividing through n into values of p(obs). F) Partial and progressive tests may be recomended in all cases where there is lack of material or where the loss of time is less importent than the cost of large scale experiments since in many cases the minimun number necessary to garantee the results within the limits of precision is rather large. One should not forget that the minimun number really represents at the same time a maximun number, necessary only if one takes into consideration essentially the disfavorable variations, but smaller numbers may frequently already satisfactory results. For instance, by definition, we know that a frequecy of p means that we expect one individual in every total o(f1-p). If there were no chance variations, this number (1- p) will be suficient. and if there were favorable variations a smaller number still may yield one individual of the desired type. r.nus trusting to luck, one may start the experiment with numbers, smaller than the minimun calculated according to the formulas given above, and increase the total untill the desired result is obtained and this may well b ebefore the "minimum number" is reached. Some concrete examples of this partial or progressive procedure are given from our genetical experiments with maize.

Estudos sobre a alimentação mineral do cafeeiro: VI Efeitos das deficiências de micronutrientes em Coffea arabica L. var. Mundo Novo cultivado em solução nutritiva

Young coffee plants (Coffea arabica L., var. Mundo Novo) were grown in nutrient solution purified from micronutrients contaminants by the method of MUNNS & JOHNSON (1960). All plants, except those in the control treatment, wer given all macronutrients and all micronutrients except one which was omitted in order to induce its shortage. Symptoms of deficiency were obtained for all known micronutrients but chlorine. Measurements, observations and chemical analysis of leaves allowed the following main conclusions to be drawn. 1. The relative influence of micronutrients in growth-measured by the fresh weight of the entire plant - was as follows: -Fe -Zn -Cu -Mo -Mn complete = -B = -CI. that is: the omission of iron from the nutrient solution caused the severest reduction in growth; lack of B and Cl had no effect. 2. Symptoms of deficiency of B, Fe, Mn, and Zn were found to be in good agreement with those in the literature. Effects of Cu and Mo shortage, however, had not been described so far: In the case of the Cu-deficient plants, the younger leaves were distorted, having an "S" shape, due probably to lack of growth of the veins; they lost their green color and developed rather large, necrotic patches near the margins. When molybdenum was omitted from the nutrient solution yellow spots develop near the margen of subterminal (fully mature) leaves; they became necrotic; there was a characteristic downward curling of the leaf blade along the mid rib so that the opposite edges touched each other underneath. 3. The levels of micronutrients found in normal and deficient leaves are given in Table 4. It is hoped that those values will serve as a basis of judgement of micronutrient contents found in leaves of field grown plants.

Taxonomic review of the Neotropical genus Neopachylus (Arachnida, Opiliones, Gonyleptidae)

A taxonomic review of the genus Neopachylus Roewer, 1913 together with keys to the species for both males and females are presented. Gephyropachylus marginatus Mello-Leitão, 1931 is considered a junior subjective synonym of Neopachylus serrinha Soares & Soares, 1947, and Huralvius incertus Mello-Leitão, 1935 is considered a synonym of Neopachylus nebulosus (Mello-Leitão, 1936). This genus is restricted to southern Brazil, occurring in states of Paraná, Santa Catarina and Rio Grande do Sul.

Household-based malaria control in a highly endemic area of Africa (Tanzania): determinants of transmission and disease and indicators for monitoring - Kilombero Malaria Project

The Kilombero Malaria Project (KMP) attemps to define opperationally useful indicators of levels of transmission and disease and health system relevant monitoring indicators to evaluate the impact of disease control at the community or health facility level. The KMP is longitudinal community based study (N = 1024) in rural Southern Tanzania, investigating risk factors for malarial morbidity and developing household based malaria control strategies. Biweekly morbidity and bimonthly serological, parasitological and drug consumption surveys are carried out in all study households. Mosquito densities are measured biweekly in 50 sentinel houses by timed light traps. Determinants of transmission and indicators of exposure were not strongly aggregated within households. Subjective morbidity (recalled fever), objective morbidity (elevated body temperature and high parasitaemia) and chloroquine consumption were strongly aggregated within a few households. Nested analysis of anti-NANP40 antibody suggest that only approximately 30% of the titer variance can explained by household clustering and that the largest proportion of antibody titer variability must be explained by non-measured behavioral determinants relating to an individual's level of exposure within a household. Indicators for evaluation and monitoring and outcome measures are described within the context of health service management to describe control measure output in terms of community effectiveness.

Ixodes (Haemixodes) longiscutatum Boero (new status) and I. (H.) uruguayensis Kohls & Clifford, a new synonym of I. (H.) longiscutatum (Acari: Ixodidae)

Females of Ixodes (Haemixodes) uruguayensis Kohls & Clifford, 1967, a species whose adults were unknown until the present, were obtained in the laboratory from engorged nymphs collected on rodents (Scapteromys tumidus and Oxymycterus nasutus) in the counties of Maldonado and San José, Uruguay. Morphological characters of these females were identical to those given in the description of the female of Ixodes longiscutatum Boero, 1944. I. uruguayensis is, thus, relegated to a junior subjective synonym of I. longiscutatum. However, because of the unique morphological characters of the immature stages, the validity of the subgenus Haemixodes Kohls & Clifford, 1967 is not questioned. Therefore, the new status of Ixodes (Haemixodes) uruguayensis Kohls & Clifford, 1967 is Ixodes (Haemixodes) longiscutatum Boero, 1944.

Schistosomiasis mansoni in Bananal (State of São Paulo, Brazil): IV. Study on the public awareness of its risks in the Palha District

A rather high prevalence of mansoni schistosomiasis has been observed in some localities of Bananal, State of São Paulo, during the past decade. The highest prevalence of schistosomiasis was found in the Palha District; it was thus considered adequate for an evaluation of public awareness of the risks involved in acquiring schistosomiasis, a likely outcome of certain behavior patterns. We interviewed 542 district-dwellers. The 5-to-39 age-group constituted 65.5% of the whole sample. Concerning the infection, 69.2% had hearsay information; 46.1% know the infection; 69.6% know how it is acquired; 31.5% know about the symptoms and 57.1% know what can be done to avoid infection; 17.7% declared to have acquired the infection at least once in their lifetime; 62.3% reported total or partial immersion in collections of water of Bananal, once or twice a week, 53.9% of these for bathing or fishing. Although most (91.7%) households have treated running water, are connected to the sewage network or have septic tanks, 9% of the people interviewed use to defecate on the field. It became clear that the educational messages aimed at this population had not been adequate, having failed to fulfil any expectations. The local people received only piecemeal and subjective information about their problem. The control of schistosomiasis requires an integrated practice, which includes the analysis of macro-determinant factors, such as basic sanitation, habitation, education and health care. In short, we require a multidisciplinary vision of the mechanisms of transmission of the infection, which depends upon adequate planning and well trained personnel, intent on their educational work, to attain satisfactory results.

Serum hyaluronan and collagen IV as non-invasive markers of liver fibrosis in patients from an endemic area for schistosomiasis mansoni: a field-based study in Brazil

Non-invasive markers of fibrosis have been used to diagnose liver fibrosis in a variety of diseases. Hyaluronic acid (HA) and collagen IV (C-IV) levels were measured in the sera of patients from an endemic area for schistosomiasis in Brazil to diagnose and to rank the intensity of liver fibrosis. Seventy-nine adult patients with schistosomiasis, in the age range of 21-82 years (49 ± 13.4) were submitted to clinical and ultrasonographic examinations. Ultrasound was employed to diagnose and categorise liver fibrosis according to World Health Organization patterns. Serum HA and C-IV levels were measured using commercial ELISA kits. Ultrasound revealed six patients with intense liver fibrosis, 21 with moderate, 23 with light and 29 without. Serum HA was able to separate individuals with fibrosis from those without (p < 0.001) and light from intense fibrosis (p = 0.029), but C-IV was not (p = 0.692). The HA diagnostic accuracy for fibrosis was 0.89. The 115.4 ng/mL cut-off level diagnosed patients with fibrosis (sensitivity 0.98, specificity 0.64). HA correlated positively with portal hypertension. Periportal fibrosis (subjective evaluation), age and collateral circulation predicted HA increase. In conclusion, we propose that serum HA can be used to identify patients with liver fibrosis in an endemic area for schistosomiasis mansoni in Brazil.

"I came from there (but no one warned me!)": reflections on people management policies that target intranational interculturality

The purpose of this article is to analyze how professionals who decided to risk intramobility in their careers and who were hired by organizations from the industrial complex of Camaçari (Bahia) perceive the development of people management strategies that target intranational interculturality within these organizations. To achieve this, besides a review and theoretical analysis of the concepts of mobility, intercultural management and people management in organizations, 13 professionals were interviewed who had moved from different Brazilian states to work in companies in this particular complex. The results indicate that generally organizations ignore intercultural aspects, which is reflected in a gap in people management strategies. One indication of this refers to the lack of initial support, which generates problems for the individuals who arrive with great expectations in their new workplace. Furthermore, there is evidence that the financial help provided is insufficient and it becomes necessary to pay attention also to subjective aspects that involve relocation and the consequent international interculturality. Finally, it is believed that expansion of the focus of studies on intercultural management, with a look at intranational aspects, makes it possible to learn theoretical and practical lessons because of the experiences of the players who underwent the process, since intercultural management and people management can generate comparative advantages for organizations.

Entrepreneurial decision-making using the knightian uncertainty approach

The article discusses the behavioral aspects that affect the entrepreneurs' decision making under the Knightian uncertainty approach. Since the profit arising from entrepreneurial activity represents the reward of an immeasurable and subjective risk, it has been hypothesized that innovative entrepreneurs have excessive optimism and confidence, which leads them to invest in high-risk activities. A behavioral model of decision making under uncertainty is used to test the hypothesis of overconfidence. This model is based on Bayesian inference, which allows us to model the assumption that these entrepreneurs are overconfident. We conclude that, under the hypothesis of overconfidence, these entrepreneurs decide to invest, despite the fact that the expected utility model indicates the contrary. This theoretical finding could explain why there are a large number of business failures in the first years of activity.

Dignity in care: where next for nursing ethics scholarship and research?

Dignity is recognised as both a central and also a contested value in bioethics discourse. The aim of this manuscript is to examine some of the key strands of the extensive body of dignity scholarship and research literature as it relates to nursing ethics and practice. The method is a critical appraisal of selected articles published in Nursing Ethics and other key manuscripts and texts identified by researchers in the UK and Brazil as influential. The results suggest a wide and rather confusing range of perspectives and findings albeit with some overall themes relating to objective and subjective features of dignity. In conclusion, the authors point to the need for more sustained philosophical engagement contextualising human dignity within a plurality of professional values. Future empirical work should explore what matters to patients, families, professionals and citizens in different cultural contexts rather than foregrounding qualitative research with such a contested concept.

Intervening factors in attention flow of professionals injured by biological material

Objective: To describe the barriers and facilitator factors to follow the attention flow of professionals injured by biological material in the worker perspective. Method: Qualitative descriptive study with data collected through individual interviews with 18 injured workers, assisted in reference public units in the city of Goiânia. The content analysis was carried out with assistance of the ATLAS.ti 6.2 software, under the work organization and subjective perspectives. Results: From the interviews regarding the barriers and facilitator factors emerged the categories: organizational structure, Support from close people, and Knowledge influence. Conclusion: The organized services have enabled more qualified consultations and the workers follow-up, which caused a satisfaction feeling in relation to the working environment.


The decision of an obese woman to have bariatric surgery: the social phenomenology

Objective To understand the process by which an obese woman decides to have bariatric surgery. Method A qualitative survey with a social phenomenology approach, carried out in 2012, with 12 women, using the phenomenological interview. Results A woman bases the decision to have the surgery on: the inappropriateness of her eating habits; a physical appearance that is incompatible with an appearance that is standardized by society; the social prejudice that she has to live with; the limitations imposed by obesity; and her lack of success with previous attempts to lose weight. Outcomes that she hopes for from the decision to have the surgery include: restoring her health; achieving social inclusion; and entering the labor market. Conclusion This study allows one to reflect that prescriptive actions do not give a satisfactory response to a complexity of the subjective questions involved in the decision to have surgery for obesity. For this, what is called for is a program of work based on an interdisciplinary approach, and training that gives value to the bio-psycho-social aspects involved in a decision in favor of surgical treatment.

Narrative interviews: an important resource in qualitative research

Objetives This methodological study explain and emphasize the extent and fertility of the narrative interview in qualitative research. Methods To describe the narrative method within the qualitative research. Results The qualitative research method is characterized by addressing issues related to the singularities of the field and individuals investigated, being the narrative interviews a powerful method for use by researchers who aggregate it. They allow the deepening of research, the combination of life stories with socio-historical contexts, making the understanding of the senses that produce changes in the beliefs and values that motivate and justify the actions of possible informants. Conclusion The use of narrative is an advantageous investigative resource in qualitative research, in which the narrative is a traditional form of communication whose purpose is to serve content from which the subjective experiences can be transmitted.

Social representation of Alzheimer's disease for family caregivers: stressful and rewarding

Abstract OBJECTIVE To understand the content of Social Representation (SR) of family caregivers of Alzheimer's disease patients. METHOD Interviews were conducted with 26 caregivers and analyzed by the ALCESTE software. RESULTS The SR content was structured in two thematic axes called Daily Life and Care and Medical and Emotional Concepts and Outcomes. The first axis creates images related to the routine of interaction with the sick person, and contains a description of care procedures, experiences, and practices applied every day. The second is composed of subjective and conceptual aspects that make up the social representation of Alzheimer's disease, with meanings related to the emotional, medical, and biological contexts. CONCLUSION Due to the importance of topics related to patients' dependence and the personal and emotional consequences of the disease, overload is the main content of the SR of Alzheimer's disease for caregivers, and the understanding of these SR by health professionals should support the planning of interventions addressing this group of individuals.