Exploring African lion (<Emphasis Type="Italic">Panthera leo</Emphasis>) behavioural phenotypes: individual differences and correlations between sociality,boldness and behaviour

Increasing our understanding of personality, at an individual and group level, is crucial to the pre-release assessment of social species within ex situ reintroduction programs. We conducted the first exploration into the personality of a captive-origin pride of African lions (Panthera leo), assessing behavioural variations and consistencies in daily activity, social and hunting behaviour, and boldness. Data were collected via direct observations, while a species-specific protocol for testing boldness, using playbacks, was developed. Differences in sex, age and session time for the activity budget were evaluated using Pearson correlations and repeated-measures ANOVA, while social interactions were analysed using social network analysis. Spearman’s correlations were conducted to assess for associations between boldness scores, activity and sociality. The two boldness tests provided a range of scores per lion, indicating that the test was effective. Correlations and variations in individual behaviour indicated that adults and sub-adults have specific roles within pride behaviour. Correlations between boldness and activity and social behaviours provided information on the role of individuals, allowing investigation into the behaviour of a dominant and a social keystone. Our study indicates that evaluating various aspects of behaviour in conjunction with boldness has the potential to assist the pre-release assessment of a pride within an ex situ reintroduction program.     

Depression,Sex and Gender Roles in Older Adult Populations: The International Mobility in Aging Study (IMIAS)

Objectives

To assess the associations between gender roles and depression in older men and women and whether gender roles are independent risk factors for depression.

Methods

International cross-sectional study of adults between 65 and 74 years old (n = 1,967). Depression was defined by a score of 16 or over in the Center for Epidemiologic Studies Depression Scale (CES-D). A validated 12-item Bem Sex Role Inventory (BSRI) was used to classify participants in gender roles (Masculine, Feminine, Androgynous, and Undifferentiated) using research site medians of femininity and masculinity as cut-off points. Poisson regressions were fitted to estimate the prevalence ratios (PR) of depression for each gender role compared to the masculine role, adjusting for sex, sufficiency of income, education, marital status, self-rated health, and chronic conditions.

Results

Among men, 31.2% were androgynous, 26% were masculine, 14.4% were feminine, and 28.4% were undifferentiated; among women, the corresponding percentages were 32.7%, 14.9%, 27%, and 25.4%. Both in men and in women, depressive symptoms (CES-D≥16) were more prevalent in those endorsing the undifferentiated type, compared to masculine, feminine or androgynous groups. However, after adjusting for potential confounders, compared to the masculine group only those endorsing the androgynous role were 28% less likely to suffer from depression: PR of 0.72 (95% CI: 0.55–0.93). In fully adjusted models, prevalence rates of depression were not different from masculine participants in the two other gender groups of feminine and undifferentiated.

Conclusions

Androgynous roles were associated with lower rates of depression in older adults, independently of being a man or a woman.     

Thermodynamics of intersubunit interactions in cholera toxin upon binding to the oligosaccharide portion of its cell surface receptor, ganglioside GM1

The binding and the energetics of the interaction of cholera toxin with the oligosaccharide portion of ganglioside GM1 (oligo-GM1), the toxin cell surface receptor, have been studied by high-sensitivity isothermal titration calorimetry and differential scanning calorimetry. Previously, we have shown that the association of cholera toxin to ganglioside GM1 enhances the cooperative interactions between subunits in the B-subunit pentamer [Goins, B., & Freire, E. (1988) Biochemistry 27, 2046-2052]. New experiments presented in this paper reveal that the oligosaccharide portion of the receptor is by itself able to enhance the intersubunit cooperative interactions within the B pentamer. This effect is seen in the protein unfolding transition as a shift from independent unfolding of the B promoters toward a cooperative unfolding. To identify the origin of this effect, the binding of cholera toxin to oligo-GM1 has been measured calorimetrically under isothermal conditions. The binding curve at 37 degrees C is sigmoidal, indicating cooperative binding. The binding data can be described in terms of a nearest-neighbor cooperative interaction binding model. In terms of this model, the association of a oligo-GM1 molecule to a B protomer affects the association to adjacent B promoters within the pentameric ring. The measured intrinsic binding enthalpy per protomer is -22 kcal/mol and the cooperative interaction enthalpy -11 kcal/mol. The intrinsic binding constant determined calorimetrically is 1.05 x 10(6) M-1 at 37 degrees C and the cooperative Gibbs free energy equal to -850 cal/mol.(ABSTRACT TRUNCATED AT 250 WORDS)     

Long-acting contraceptive agents: Esters of norethisterone with alkoxy- and halogeno-substituted carboxylic acids

The chemical synthesis and physical data of several new esters of norethisterone (17α-ethynyl-17β-hydroxyestr-4-en-3-one) are reported, which contain either a chloro- or an alkoxy-group as a substituent in the acid side-chain.     

Paracoccidioidomycosis in a four-year-old boy

Summary A case of fatal, generalized paracoccidioidomycosis is described in a four-year-old urban dwelling child. Marked lympadenopathy, hepatosplenomegaly and an abdominal mass were the main clinical manifestations. The diagnosis was established by histopathological studies and culture. The authors comment on the rarity of this infection in children less than 7 years of age and on the importance of considering this pathology in the differential diagnosis of malignant non-Hodgkin lymphoma and tuberculosis, in children.Medical Student of the Federal University of Bahia.     

Fuc-GM1 ganglioside mimics the receptor function of GM1 for cholera toxin.

The ability of Fuc-GM1 ganglioside to mimic the receptor function of GM1 for cholera toxin (CT) has been investigated. For this purpose, rat glioma C6 cultured cells were enriched with Fuc-GM1 and the responsiveness to CT was compared with that of cells enriched with GM1 ganglioside. Fuc-GM1 was taken up by cells as rapidly and to the same extent as GM1. When comparable amounts of ganglioside were associated, the cells enriched with Fuc-GM1 bound the same amount of 125I-CT as did cells enriched with GM1. Under conditions in which GM1- and Fuc-GM1-enriched cells bound comparable amounts of CT, the Fuc-GM1-treated cells accumulated virtually the same amount of cyclic AMP as did GM1-treated cells, and activation of adenylate cyclase was also similar. The lag time preceding the CT-induced cAMP accumulation was the same in Fuc-GM1- and GM1-enriched cells. High-sensitivity isothermal titration calorimetry (ITC) experiments showed that the association constants of CT with Fuc-GM1 or GM1 ganglioside were comparable (4 x 10(7) M-1 and 1.9 x 10(7) M-1, respectively, at 25 degrees C). Also, the association constants of the B-subunit pentamer with Fuc-GM1 or GM1 ganglioside were comparable (about 3 x 10(7) M-1 and 7 x 10(7) M-1, respectively, at 25 degrees C).     

Expression of the rat prothymosin alpha gene during T-lymphocyte proliferation and liver regeneration.

Prothymosin alpha (ProT alpha) is a widely distributed acidic protein whose function has been related to cell proliferation. We have analyzed the expression of the rat ProT alpha gene in several proliferative systems: concanavalin A (ConA)/interleukin-2-stimulated thymocytes, ConA-stimulated splenic T-lymphocytes, and hepatocytes proliferating during liver regeneration. In these systems, ProT alpha mRNA was detected in all stages of the cell cycle, with maximal increments (2-4-fold) at the beginning of the S phase. By contrast, the mRNAs for proliferating cell nuclear antigen/cyclin and histone H3, two cell-cycle-regulated proteins, were hardly detected in resting cells but increased notably at the G1/S boundary and in the S phase, respectively. Treatment of T-cells with the calcium ionophore A23187 increased ProT alpha mRNA levels 2.5-fold, whereas phorbol 12-myristate 13-acetate, a protein kinase C activator, had no effect on ProT alpha gene expression. Incubation of ConA-stimulated T-cells with hydroxyurea, a DNA synthesis inhibitor, did not decrease the levels of ProT alpha mRNA, indicating that its expression is independent of DNA synthesis. These findings suggest that ProT alpha is required throughout all the stages of the cell cycle, resembling a constitutively expressed gene rather than one strictly involved in cell proliferation.     

Stability mutants of staphylococcal nuclease: large compensating enthalpy-entropy changes for the reversible denaturation reaction

By use of intrinsic fluorescence to determine the apparent equilibrium constant Kapp as a function of temperature, the midpoint temperature Tm and apparent enthalpy change delta Happ on reversible thermal denaturation have been determined over a range of pH values for wild-type staphylococcal nuclease and six mutant forms. For wild-type nuclease at pH 7.0, a Tm of 53.3 +/- 0.2 degrees C and a delta Happ of 86.8 +/- 1.4 kcal/mol were obtained, in reasonable agreement with values determined calorimetrically, 52.8 degrees C and 96 +/- 2 kcal/mol. The heat capacity change on denaturation delta Cp was estimated at 1.8 kcal/(mol K) versus the calorimetric value of 2.2 kcal/(mol K). When values of delta Happ and delta Sapp for a series of mutant nucleases that exhibit markedly altered denaturation behavior with guanidine hydrochloride and urea were compared at the same temperature, compensating changes in enthalpy and entropy were observed that greatly reduce the overall effect of the mutations on the free energy of denaturation. In addition, a correlation was found between the estimated delta Cp for the mutant proteins and the d(delta Gapp)/dC for guanidine hydrochloride denaturation. It is proposed that both the enthalpy/entropy compensation and this correlation between two seemingly unrelated denaturation parameters are consequences of large changes in the solvation of the denatured state that result from the mutant amino acid substitutions.     

Impact of Extraction Parameters on the Recovery of Lipolytic Activity from Fermented Babassu Cake

Enzyme extraction from solid matrix is as important step in solid-state fermentation to obtain soluble enzymes for further immobilization and application in biocatalysis. A method for the recovery of a pool of lipases from Penicillium simplicissimum produced by solid-state fermentation was developed. For lipase recovery different extraction solution was used and phosphate buffer containing Tween 80 and NaCl showed the best results, yielding lipase activity of 85.7 U/g and 65.7 U/g, respectively. The parameters with great impacts on enzyme extraction detected by the Plackett-Burman analysis were studied by Central Composite Rotatable experimental designs where a quadratic model was built showing maximum predicted lipase activity (160 U/g) at 25°C, Tween 80 0.5% (w/v), pH 8.0 and extraction solution 7 mL/g, maintaining constant buffer molarity of 0.1 M and 200 rpm. After the optimization process a 2.5 fold increase in lipase activity in the crude extract was obtained, comparing the intial value (64 U/g) with the experimental design (160 U/g), thus improving the overall productivity of the process.