Pairs Of Canonical Variables Research Articles

Pelvic floor ultrasound versus urodynamics in evaluating insensible urinary incontinence: A retrospective study

Insensible Urinary Incontinence (IUI) is a situation when you complain of urinary incontinence but are unaware of how it occurred. Therefore, it is necessary to apply highly specific diagnostic methods to promote accuracy in the diagnosis of IUI, including pelvic floor ultrasound (PFU) and urodynamic studies (UDS). A total of 41 women with IUI were retrospectively included. Patients were categorized into two groups: the urodynamic urinary incontinence group (UUI group, n=20) and the non-urodynamic urinary incontinence group (NUUI group, n=21), according to the urine leakage during UDS. The baseline clinical characteristics, UDS results, and PFU parameters were collected. Compared with the NUUI group, the UUI group had a smaller maximum cystometric capacity (P=0.008), lower maximum urethral closure pressure (P=0.005), shorter functional urethral length (FUL) (P=0.01), more bladder neck funneling (BNF) (P=0.02), greater BNF depth (P=0.04), and larger BNF area (P=0.01). The area and depth of BNF were negatively correlated with maximum urethral closure pressure (r=-0.42, P=0.01), FUL (r=-0.36, P=0.02 versus r=-0.39, P=0.01), and maximum cystometric capacity (r=-0.35, P=0.03), but positively correlated with maximum urinary flow rate (r=0.33, P=0.04 versus r=0.36, P=0.02). The canonical correlation analysis of the ultrasound parameters and UDS parameters shows that the first pair of canonical variables was statistically significant (r1=0.9, P<0.001). The PFU is associated with UDS in evaluating IUI. It has the advantages of low cost and high comfort, thus should be used as an auxiliary examination for IUI.

On coupled envelope evolution equations in the Hamiltonian theory of nonlinear surface gravity waves

This paper presents a novel theoretical framework in the Hamiltonian theory of nonlinear surface gravity waves. The envelope of surface elevation and the velocity potential on the free water surface are introduced in the framework, which are shown to be a new pair of canonical variables. Using the two envelopes as the main unknowns, coupled envelope evolution equations (CEEEs) are derived based on a perturbation expansion. Similar to the high-order spectral method, the CEEEs can be derived up to arbitrary order in wave steepness. In contrast, they have a temporal scale as slow as the rate of change of a wave spectrum and allow for the wave fields prescribed on a computational (spatial) domain with a much larger size and with spacing longer than the characteristic wavelength at no expense of accuracy and numerical efficiency. The energy balance equation is derived based on the CEEEs. The nonlinear terms in the CEEEs are in a form of the separation of wave harmonics, due to which an individual term is shown to have clear physical meanings in terms of whether or not it is able to force free waves that obey the dispersion relation. Both the nonlinear terms that can only lead to the forcing of bound waves and those that are capable of forcing free waves are demonstrated, in the case of the latter through the analysis of the quartet and quintet resonant interactions of linear waves. The relations between the CEEEs and two other existing theoretical frameworks are established, including the theory for a train of Stokes waves up to second order in wave steepness (Fenton, ASCE J. Waterway Port Coastal Ocean Engng, vol. 111, issue 2, 1985, pp. 216–234) and a semi-analytical framework for three-dimensional weakly nonlinear surface waves with arbitrary bandwidth and large directional spreading by Li &amp; Li (Phys. Fluids, vol. 33, issue 7, 2021, 076609).

Canonical correlation analysis of factors that influence quality of life among patients with chronic obstructive pulmonary disease based on QLICD-COPD (V2.0).

BackgroundThe Quality of Life Instrument for Chronic Diseases (QLICD)-COPD (V2.0) was designed to assess the health condition of patients with chronic obstructive pulmonary disease (COPD). The objective of this study was to evaluate the quality of life (QOL) of patients, the influential clinical factors and the relationships between QOL and clinical objective indicators.MethodsTwo hundred and sixty-one inpatients with COPD in the acute exacerbation stage were evaluated using the QLICD-COPD (V2.0) and data on clinical objective indicators were collected. The relationships between QOL and the clinical objective indicators were determined using canonical correlation analysis.ResultsThe standardised scores for the patients in four domains, namely, physical function, psychological function, social function and a disease-specific module, were 49.00±12.91, 59.89±13.51, 68.59±11.94 and 51.84±13.58, respectively. The total score for the QOL of patients was 57.17±10.26. Two pairs of canonical variables were statistically significant (r1=0.35, p<0.0001; r2=0.26, p<0.05). These variables accounted for 45.8% and 33.8% of the variance, respectively. The levels of total protein, albumin, serum sodium and alkaline phosphatase and the percentages of neutrophils and lymphocytes were correlated with the QOL, with correlation coefficients ranging from −0.435 to 0.675.ConclusionClinicians should pay close attention to the levels of total protein, albumin, serum sodium and alkaline phosphatase and the percentages of neutrophils and lymphocytes to improve the QOL of patients.

The structural characteristics and influential factors of psychological stress of urban residents in Jiangxi province during the COVID-19 pandemic: cross sectional study

AimsTo explore the structural characteristics and influential factors of psychological stress of urban residents in Jiangxi province during the COVID-19 pandemic through a survey of psychological stress, personality traits, family function and life satisfaction. MethodsBy the convenient sampling, 1422 urban residents from Jiangxi province were assessed with Eysenck Personality Questionnaire Short Scale (EPQ-RSC), Psychological Questionnaires for Emergent Events of Public Health (PQEEPH), Family APGAR Scale (APGAR) and Satisfaction With Life Scale (SWLS). The relation among personality traits, psychological stress, family function and life satisfaction during the COVID-19 pandemic was analyzed by using the canonical correlation analysis and the serial mediation model. Results(1) Among the estimated correlation coefficients, the first two pairs were significant (P < 0.001 in each). (2) In the first pair of canonical variables, the loadings of neuroticism and neurasthenia were the higher (0.94, 0.70). (3) Neuroticism and life satisfaction mediated the relationship between family function and neurasthenia (βneuroticism = -0.174; 95%CI:-0.224, -0.134; βlife satisfaction = -0.034, 95%CI:-0.012, -0.062), respectively. In addition, serial mediation analyses indicated that the association of family function and neurasthenia is mediated by neuroticism and life satisfaction in a sequential manner (β = -0.010; 95%CI:-0.020, -0.004). ConclusionsDuring the COVID-19 pandemic, neuroticism was closely related to psychological stress of urban residents, especially neurasthenia. In addition, the serial mediating effect of neuroticism and life satisfaction played an important role in the process of family function influencing neurasthenia. These findings contributed to a more comprehensive understanding of the influential factors for psychological stress of urban residents during the COVID-19 pandemic.

Agronomic characteristics of Serapias vomeracea (Burm. f.) Briq. salep orchids

Although salep orchids are annual plants, each new generation emerges larger than their parents. There are no data on the developmental performance of these species that cannot be cultivated due to production difficulties. This study discusses Salep vomeracea (Burm. f.) Briq., one of the most common species in temperate climate regions. Tubers obtained from natural flora were divided into seven groups according to their size. Morphological characteristics of the seedlings developed from these tubers were determined and observed up to the harvest stage. The study was carried out in a randomized plot design with three replications and for two years. As a result of statistical analysis, all parameters were found to be significant. The canonical correlation between the first pair of canonical variables was 0.995 (p&lt;0.01). The data obtained from the length of the planted tuber made the biggest contribution to the explanatory power of the canonical variables. Additionally, the mathematical relationship between width, height and area values of salep leaves was determined.

Morphological Developments of Orchis purpurea Huds. Salep Orchids

Abstract This article aims to monitor the development of Orchis purpurea Huds., salep orchids, of different sizes over a period of two years, and to investigate the relationship between the parameters studied. In the first step, the measurements taken at the time of planting and harvesting of tubers divided into eight different groups according to their size were subjected to variance and Duncan's test. In the second step, the relationship between the parameters was investigated by ignoring seedling groups. The relationship between the two variables was determined by correlation analysis. The significance of the relationships between planting and harvest data sets, and variable contributions were determined by canonical correlation analysis. Finally, leaf area prediction modeling was performed by applying multiple regression analysis. In variance analysis all parameters were significant. The canonical correlation between the first pair of canonical variables was 0.988 (p<0.01). The data obtained from the tubers made the greatest contribution to the explanatory power of the canonical variables. The leaf area model was formulized as LA (mm2) = -1237.0204 + 57.7912 × LW + 16.6211 × LL where LA is leaf area, LW is leaf width, LL is leaf length and a, b, and c are coefficients.

The relationship of social support, mental health, and health-related quality of life in human immunodeficiency virus-positive men who have sex with men: From the analysis of canonical correlation and structural equation model: A cross-sectional study.

The objective of this study was to reveal the relationships of mental health, social support, health-related quality of life (HRQOL) as well as their dimensions in HIV-positive men who have sex with men (MSM).HIV-positive MSM were interviewed by a cross-sectional study design using the world Health Organization quality of life bref scale, social support rating scale, and self-rated anxiety and depression scales. Canonical correlation analysis and structural equation model (SEM) were utilized to analyze to the collected data.Three first pair of canonical variables that was statistically significant (P < .0001) and verified could account for the largest cumulative proportion were computed from canonical correlation analysis. The results showed, among the dimensions, depression and anxiety were negatively correlated with support utilization and physical health, while subjective support and support utilization were positively correlation with social relationship health. Structural equation model results showed that support utilization (0.632, T = 10.44), depression (0.816, T = 20.37), and environmental dimension (0.833, T = 38.47) had the largest standardized factor loading in social support, mental health, and HRQOL. The structural coefficient between social support and mental health was −0.433 (T = −5.88), between mental health and HRQOL was −0.592 (T = −10.33), between social support and HRQOL was 0.290 (T = 4.10), indicated social support not only exerted a direct influence, but also mediated mental health to have an indirect effect on HRQOL for HIV-positive MSM.Environmental dimension is the foremost factor of HRQOL for HIV-positive MSM. Alleviating anxiety symptoms maybe improve physical health, while promoting the support utilization is an effective measure of alleviating depression and improving social relationship health for this special group.

Hamiltonian formalism forf(T)gravity

We present the Hamiltonian formalism for $f(T)$ gravity, and prove that the theory has $\frac{n(n-3)}{2}+1$ degrees of freedom (d.o.f.) in $n$ dimensions. We start from a scalar-tensor action for the theory, which represents a scalar field minimally coupled with the torsion scalar $T$ that defines the teleparallel equivalent of general relativity (TEGR) Lagrangian. $T$ is written as a quadratic form of the coefficients of anholonomy of the vierbein. We obtain the primary constraints through the analysis of the structure of the eigenvalues of the multi-index matrix involved in the definition of the canonical momenta. The auxiliary scalar field generates one extra primary constraint when compared with the TEGR case. The secondary constraints are the super-Hamiltonian and supermomenta constraints, that are preserved from the Arnowitt-Deser-Misner formulation of GR. There is a set of $\frac{n(n-1)}{2}$ primary constraints that represent the local Lorentz transformations of the theory, which can be combined to form a set of $\frac{n(n-1)}{2}-1$ first-class constraints, while one of them becomes second-class. This result is irrespective of the dimension, due to the structure of the matrix of the brackets between the constraints. The first-class canonical Hamiltonian is modified due to this local Lorentz violation, and the only one local Lorentz transformation that becomes second-class pairs up with the second-class constraint $\pi \approx 0$ to remove one d.o.f. from the $n^2+1$ pairs of canonical variables. The remaining $\frac{n(n-1)}{2}+2n-1$ primary constraints remove the same number of d.o.f., leaving the theory with $\frac{n(n-3)}{2}+1$ d.o.f. This means that $f(T)$ gravity has only one extra d.o.f., which could be interpreted as a scalar d.o.f.

Canonical Correlation Analysis Between Residents’ Living Standards and Community Management Service Levels in Rural Areas: An Empirical Analysis Based on Municipal Data in Anhui Province

Abstract Improving the rural community management service level can effectively optimize the rural community living condition, provide a better social environment for rural residents to start up business and promote the living standard of rural residents. This paper presents quantitative research on the correlation between rural residents’ living standards and rural community management service levels on the basis of 16 municipalities’ data in Anhui province in 2015. The results of the study are as follows: road mileage per every ten thousand people, rural water improvement profitability and rural sanitary toilet penetration have a decisive influence on the improvement of living standards in Anhui rural areas; specifically, the first pair of canonical variables has a fairly accurate predictive ability in road mileage per every ten thousand people, rural water improvement profitability, rural sanitary toilets penetration, per capita disposable income and per capita consumption expenditure but has a poor predictive ability in the enrollment rate of the new rural cooperative medical system. Additionally, the first pair of canonical variables can explain and predict the corresponding variables quite well, and the rural community management service level has an evident interaction effect with the living standard of rural residents.

Callan-Giddings-Harvey-Strominger vacuum in loop quantum gravity and singularity resolution

We study here a complete quantization of a Callan-Giddings-Harvey-Strominger (CGHS) vacuum model following loop quantum gravity techniques. Concretely, we adopt a formulation of the model in terms of a set of new variables that resemble the ones commonly employed in spherically symmetric loop quantum gravity. The classical theory consists of two pairs of canonical variables plus a scalar and diffeomorphism (first class) constraints. We consider a suitable redefinition of the Hamiltonian constraint such that the new constraint algebra (with structure constants) is well adapted to the Dirac quantization approach. For it, we adopt a polymeric representation for both the geometry and the dilaton field. On the one hand, we find a suitable invariant domain of the scalar constraint operator, and we construct explicitly its solution space. There, the eigenvalues of the dilaton and the metric operators cannot vanish locally, allowing us to conclude that singular geometries are ruled out in the quantum theory. On the other hand, the physical Hilbert space is constructed out of them, after group averaging the previous states with the diffeomorphism constraint. In turn, we identify the standard observable corresponding to the mass of the black hole at the boundary, in agreement with the classical theory. We also construct an additional observable on the bulk associated with the square of the dilaton field, with no direct classical analog.

Canonical correlations reveal co-variability between spike trains and local field potentials in area MT)

Patterns of neuronal correlations can provide important clues about the structure of the underlying network and how it processes information. Several recent studies have found that neural population activity across a region can be explained in large part by a shared, low-dimensional signal [1-5]. Population-wide correlation is likely to influence the local field potential (LFP) - an epiphenomenon that reflects low-frequency, concerted neural activity from anatomically connected circuits. Here, we show that LFP and spike trains recorded simultaneously from the middle temporal (MT) area of the awake macaque indeed share population-wide correlation. We apply canonical correlation analysis (CCA) to 16 channels of LFP and 16 spike sorted neurons (from 12 channels) acquired at 50 ms temporal resolution during inter-trial intervals (when the monkey was free to make eye movements), as well as during performance of a perceptual decision-making task (when the monkey maintained fixation and discriminated the direction of visual motion). CCA finds instantaneous linear projections of the LFP that maximize the correlation to corresponding projections of the population spike trains. Previous studies have suggested using population spike rate as a proxy for the local network state [3,5]. Applied to our dataset, we obtain a correlation coefficient of -12% between population spike rate and the mean LFP during inter-trial interval segments. In contrast, we obtain pairs of canonical variables with corresponding canonical correlations 29%, 26%, and 21%. We then applied the extracted projections to the task-relevant motion stimulus integration window. We find that the correlation of the projections is maintained for the 1st (31%) and 3rd (18%) components, but drops significantly for the 2nd component (7%)-- indicating a task-specific decoupling of LFP and spikes in a subspace uncovered by CCA. Upon further analysis, each CCA projection showed a distinct stimulus encoding pattern in spike rate and LFP. We hypothesize that CCA projections reveal functional, virtual units of information processing. The LFP is an important source of information when neural activity is correlated. It can indicate the strength of correlations, and the common input giving rise to such correlations. Additionally, the LFP provides increased statistical power to analyses, especially in areas where large-scale recording is anatomically difficult. CCA is a simple technique that can reveal low-dimensional structure in the data, uncovering components which maximize covariability between LFP and spike trains within MT.

Relationship between organisational commitment and burnout syndrome: a canonical correlation approach.

Objective Burnout syndrome can significantly reduce the performance of health workers. Although many factors have been identified as antecedents of burnout, few studies have investigated the role of organisational commitment in its development. The purpose of the present study was to examine the relationships between subdimensions of burnout syndrome (emotional exhaustion, depersonalisation and personal accomplishment) and subdimensions of organisational commitment (affective commitment, continuance commitment and normative commitment). Methods The present study was a cross-sectional survey of physicians and other healthcare employees working in the Ministry of Health Ordu University Education and Research Hospital. The sample consisted of 486 healthcare workers. Data were collected using the Maslach Burnout Inventory and the Organisation Commitment Scale, and were analysed using the canonical correlation approach. Results The first of three canonical correlation coefficients between pairs of canonical variables (Ui , burnout syndrome and Vi, organisational commitment) was found to be statistically significant. Emotional exhaustion was found to contribute most towards the explanatory capacity of canonical variables estimated from the subdimensions of burnout syndrome, whereas affective commitment provided the largest contribution towards the explanatory capacity of canonical variables estimated from the subdimensions of organisational commitment. Conclusions The results of the present study indicate that affective commitment is the primary determinant of burnout syndrome in healthcare professionals. What is known about the topic? Organisational commitment and burnout syndrome are the most important criteria in predicting health workforce performance. An increasing number of studies in recent years have clearly indicated the field's continued relevance and importance. Conversely, canonical correlation analysis (CCA) is a technique for describing the relationship between two variable sets simultaneously to produce both structural and spatial meaning. What does this paper add? To our knowledge, CCA has not been used to determine the relationships between burnout and organisational commitment of physicians and other healthcare staff. Accordingly, the present study adds information regarding the relationship between burnout and organisational commitment variables determined using CCA. This analysis is used to describe the relationship between two variable sets simultaneously and allows for an easy method of interpretation. What are the implications for practitioners? Burnout syndrome is a major threat to both the health workforce and its organisations. In addition, it affects the quality and effectiveness of health care. Thus, the findings of the present study offer a solid foundation from which actions to decrease burnout levels in healthcare professionals can be implemented by successfully increasing levels of organisational commitment.

Associations between psychosocial aspects of English classroom environments and motivation types of Chinese tertiary-level English majors

This study involved whether psychosocial aspects of English classroom environments had associations with the English learning motivation types of Chinese tertiary-level English majors based on a case study of approximate 1,000 English majors in their first 2 years at one of the key universities located in South China. Canonical correlation analysis revealed that students’ perceptions of their English classroom psychosocial environments and their motivation types were associated through two pairs of canonical variables. Among these, environment dimensions of Involvement and Task Orientation were found to be predictors of the motivation types of Intrinsic Interest, Social Responsibility and Individual Development, while the environmental dimensions of Teacher Support was found to have positive associations with the motivation types of Immediate Achievement and Information Medium.

The Relationship betweenEFL Learners’ Self-Identity Changes, Motivation Types, and EFL Proficiency

This study aimed to explore the relationships between foreign language learners’ self-identity changes, motivation types, and Foreign Language proficiency associated with learning English in private language schools in Iranian context. Based on a stratified sampling, 204 English as a foreign language learners from three language schools in Tehran were selected to participate in the study. The instruments were a 30-item Likert-scale questionnaire on motivation types in seven categories: intrinsic interest, immediate achievement, learning situation, going aboard, social responsibility, individual development, and information medium; a 24-item Likert-scale questionnaire on self-identity changes in six categories: self-confidence change, additive change, subtractive change, productive change, split change, and zero change. Results revealed that self-confidence change was the prominent change common among foreign language learners. Canonical correlation analysis revealed that motivation types and self-identity changes were related through three pairs of canonical variables: intrinsic orientations related with personal identity changes, instrumental orientations related with cultural changes, and instrumental orientations related learners’ self-confidence change. Theoretical and pedagogical implications for foreign language learning and teaching are also discussed.

Canonical correlation analysis on joint production: empirical study for the desirability of linear and log linear estimation in terms of crude oil and petroleum products

Canonical correlation analysis seeks to identify and quantify the associations between two sets of variables. Harold Hotelling, who initially developed the technique, provided the example of relating arithmetic speed and arithmetic power to reading speed and reading power. Relating governmental policy variables with economic goal variables and relating college performance variables with precollege variables are other examples of this type. Canonical correlation analysis focuses on the correlation between a linear combination of the variables in one set and a linear combination of the variables in another set. The idea is first to determine the pair of linear combinations having the largest correlation. Next, we determine the pair of linear combinations having the largest correlation among all pairs uncorrelated with the initially selected pair. The process continues. The pairs of linear combinations are called the canonical variables, and their correlations are called canonical correlations. The canonical correlations measure the strength of association between the two sets of variables. The maximization aspect of the technique represents an attempt to concentrate a high-dimensional relationship between two sets of variables into a few pairs of canonical variables. An attempt has been made here to analyse the jointly produced goods crude oil and petroleum products using linear and log-linear estimation based on Harold Hotelling canonical correlation approach and to compare these two estimation procedures among themselves. The analysis suggests that log-linear estimation is superior to the linear estimation for such type of study.

Karayaka Kuzularında, Sütten Kesim Zamanında ve Doğumda Ölçülmüş Bazı Özellikler Arasındaki İlişkinin Tahmini İçin Kanonik Korelasyon Analizi

Summary In this study, canonical correlation analysis was applied to estimate the relationship between six different morphologic traits (X set – birth weight (BW), body length (BL), height at withers (HW), chest depth (CD), chest width (CW) and chest girth (CG)) measured at birth and the morphological traits measured at weaning time (Y set – weaning weight (WW), body length (BL_W), height at withers (HW_W), chest depth (CD_W), chest width (CW_W) and chest girth (CG_W)) measured from 121 Karayaka lambs, raised at Gaziosmanpasa University. First of estimated six different canonical correlation coefficients (CCC) (r=0.668) between the pairs of canonical variables were found significant (P<0.05). The results of canonical correlation analysis indicated that height at withers, chest girth and birth weight had largest contribution for the explanatory capacity of canonical variables estimated from the morphologic traits of Karayaka lambs at the birth when compared with other body measurements. Height withers and chest girth had largest contribution for the explanatory capacity of canonical variables estimated from the morphological traits of the lambs at the weaning time when compared with other body measurements. As results of this study showed that height at withers, body weight and chest girth measured at birth can be used as early selection criteria for genetic improvement in Karayaka lambs.

Friction-induced enhancement in the optical activity of interacting chiral molecules

The stability of chiral molecules described by a non-linear two-state system which accounts for mean–field interactions between different isomers, including any external chiral influence (in particular, the parity violating energy difference) is investigated. By introducing the population and phase difference of the chiral states as a pair of canonical variables, driving an analogy to a bosonic Josephson junction, our study to include dissipative effects in condensed phase described by a Caldeira–Leggett like Hamiltonian is extended using the Langevin formalism. Dissipative effects produce an enhancement in the population difference, not leading to racemization.

Canonical correlation analysis for the determination of relationships between plant characters and yield components in red pepper (Capsicum annuum L. var. conoides (Mill.) Irish) genotypes

In this study, a canonical correlation analysis (CCA) was used to estimate relationships between plant characters (X set-fruit length (FL), fruit width (FW), fruit wall thickness (FWT), placenta length, stem thickness, plant height (PH), leaf length, leaf width, flowering time (50%), and time to maturity), and yield components (Y set-total fruit weight per plant (FW/P), average fruit weight and number of fruits per plant (FN/P)) of 56 red peppers (Capsicum annuum L. var. conoides (Mill.) Irish) in populations collected from the Samsun province in the Black Sea Region of Turkey. All canonical correlation coefficients (0.708, 0.635, 0.413) between the pairs of canonical variables were found to be significant (P &lt; 0.01). The findings obtained from the CCA indicate that FN/P had the largest contribution for the explanatory capacity of canonical variables estimated from yield components of 56 red pepper populations when compared with other yield components. FL and PH had largest contribution for the explanatory capacity of canonical variables estimated from plant characters when compared with other characters. The results of this study show that PH, FWT and FW should be used with the aim of increasing yield per plant in red pepper genotypes.

Canonical correlation of milk immunoglobulins, lactoferrin concentration and Dairy Herd Improvement data of Chinese Holstein cows

In this study, canonical correlation analysis was applied to estimate the relationships of DHI data with milk Ig (IgG1, IgA, and IgM) and Lf concentrations. Specifically, we evaluated the relationships between two groups of variables: milk IgG1, IgA, IgM and Lf concentration as variables ( y) and lactation number, stage of lactation, daily milk production, milk fat, protein, lactose, milk total solids and somatic cell score (SCS) as variables ( x). The results indicated that four canonical variables were identified. The canonical correlations of the first and second pairs of canonical variables were 0.662 and 0.469 respectively, which were highly significant and accounted for 91.6% of the variability observed in the data. Stage of lactation, daily milk production, milk protein and SCS were the significant factors affecting milk Lf concentration in both canonical correlations and multiple correlation analysis, and lactation number was the significant factors affecting milk IgG1 concentration. The first standardized canonical variation combination could be regarded as a predictable measure of Lf concentration and the second as a predictor of IgG1 level. These results indicated that dairy producers could select cows for increased Ig and Lf production using DHI data directly.

Inter-relações entre as propriedades físicas e os coeficientes da curva de retenção de água de um latossolo sob diferentes sistemas de uso

O comportamento físico e hídrico do solo fundamenta as práticas de seu uso e manejo. O objetivo deste trabalho foi avaliar as inter-relações entre as propriedades físicas e os coeficientes da curva de retenção de água de um Latossolo Vermelho distrófico sob diferentes sistemas de uso. Em 2004, foram selecionadas três áreas contíguas utilizadas por mais de vinte anos com mata (nativa), pousio (Brachiaria decumbens) e cultivo (culturas anuais). Foram coletadas 25 amostras de solo com estrutura não deformada na camada de 0-0,15 m de profundidade, que foram utilizadas para determinação das curvas de retenção de água do solo. As curvas de retenção de água foram ajustadas pela equação de van Genuchten, obtendo-se os coeficientes qs, qr, a e n. Também foram mensuradas as variáveis densidade do solo, teor de C orgânico e teor de argila do solo (grupo I). Essas variáveis e os coeficientes das curvas de retenção do solo (grupo II) foram submetidos às análises de correlações canônicas. Verificou-se que a intensificação do uso do solo (mata, pousio e cultivo) resultou em maiores valores de densidade do solo e na redução dos teores de C orgânico e argila. O primeiro par das variáveis canônicas indicou dependência de qs em relação a densidade, e o segundo par distinguiu os sistemas de uso do solo verificado pela dependência de qr em relação aos teores de argila e de C orgânico. As modificações dos teores de C orgânico e da densidade do solo sugerem a degradação da qualidade física e hídrica do solo.