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PubMed1994

Cultural diversity in causal attributions for illness: the role of the supernatural.

We investigated cultural diversity in beliefs about the causes of illness and assessed the possibility that popular free-form methodologies (asking subjects to generate causes) inhibit minorities from expressing their belief in supernatural causes. As predicted, when asked to generate causes of illness and rate these in terms of their importance, whites and minorities did not differ in the number or type (natural vs supernatural) of causes they generated or in the importance rating they assigned to these. However, when these same subjects were provided with natural and supernatural causes to rate in terms of importance, minorities rated supernatural causes significantly more important than did whites, and more minorities than whites endorsed such causes. Cultural differences in causal attributions for illness are examined, and the role of methodology in determining such attributions is highlighted.

Adolescent↗
PubMed1981

Influence of enzymatic phospholipid cleavage on the permeability of the erythrocyte membrane: III. Discrimination between the causal role of split products and of lecithin removal.

Cleavage of 55% of the lecithin in intact human erythrocytes by phospholipase A2 (bee venom) markedly inhibits the mediated transport of L-lactate (via the monocarboxylate carrier) and of L-arabinose (via the monosaccharide carrier), while the major anion exchange system (probed by oxalate) and diffusion via the lipid domain (probed by erythritol) remain essentially unaltered. the causal role of the split products, unsaturated fatty acids and saturated lysolecithin, and of lecithin removal were now studied by sequential extraction of split products with serum albumin and by their controlled insertion into normal membranes. Careful choice of the albumin-to-cell ration allowed the extraction of more than 95% or the fatty acids and up to 80% of the lysolecithin without hemolysis. Extraction of fatty acids abolished inhibition of lactate and arabinose transfer, but induced inhibition of anion exchange and translipid permeation. Subsequent extraction of lysolecithin produced no further effects except on lactate transfer, which was inhibited. Exogenous oleic and linoleic acid, at intramembrane concentrations equal to those produced by phospholipase A2, inhibit lactate and arabinose transfer, while accelerating oxalate and erythritol movements, in agreement with effects of endogenous fatty acids. Exogenous lysolecithin inhibits all mediated transfer processes but does not alter translipid permeation. This pattern differs from that obtained for endogenous lysolecithin. The action of exogenous lysolecithin can be suppressed by loading of the cells with cholesterol. Insertion of exogenous lysolecithin into cells depleted of endogenous lysolecithin does not restore the functional state before depletion, indicating that exogenous and endogenous lysolecithin may act differently.

Biological Transport↗
PubMed1996

A comparison of the nucleotide sequence of the cerato-ulmin gene and the rDNA ITS between aggressive and non-aggressive isolates of Ophiostoma ulmi sensu lato, the causal agent of Dutch elm disease.

Little genetic information exists comparing aggressive and non-aggressive isolates of the causal agent of Dutch elm disease, Ophiostoma ulmi. Two genetic elements were compared between the subgroups. The ceratoulmin cu gene product has been associated with disease symptoms. Nucleotide-sequence analysis of cu and the internal transcribed spacer (ITS) region of the rDNA were made from three aggressive and three non-aggressive isolates of the pathogen. Our results suggested uniformity within, and unique differences between, subgroups. Differences were detected for cu in the promoter, coding, and transcription termination regions. Sequence data for the ITS clearly distinguish the subgroups.

Amino Acid Sequence↗
PubMedDate not supplied

Does anxiety or cardiovascular reactivity have a causal role in hypertension?

Anxiety, stress, and cardiovascular reactivity (CVR) are variously believed to play a role in sustained hypertension. Although acute anxiety or stress elicits acute pressor responses, there is little support for their significant role in sustained hypertension. Anxiety correlates poorly with CVR, and blood pressure levels and anxiolytics do not sustain blood pressure lowering in subjects with hypertension-associated anxiety. Chronic anxiety disorders tend to be characterized by relatively low blood pressure and prevalence of sustained hypertension. Blood Pressure Regulation in hypertension is normal, and normo- and hypertensives have similar ambulatory blood pressure variability. Laboratory CVR fails to predict variability in natural environments, hyperreactors do not exhibit increased variability in natural environments, and the increased variability and ambulatory reactivity that is "accounted for" by laboratory responses is small. These findings do not support the belief that hypertension is related to a summation of heightened pressor responses over time. Antihypertensives normalize elevated blood pressures but do not alter CVR in the laboratory or variability in natural environments, probably because of a dual central regulation of resting and reactive blood pressures. Psychological stress responses result from selective neuronal activation rather than from generalized sympathetic neural responses or dysregulation. Differences in blood pressure responses during various emotions are only quantitative, with no specificity of sympathoadrenal or emotional responses to stressors. It may be time to regard reactive cardiovascular responses as physiological, rather than as psychological, and to require much stronger evidence to confirm causal roles of anxiety, stress, and reactivity in sustained hypertension.

Anxiety↗
PubMed2002

Population genetic structure of Pyrenophora teres Drechs. the causal agent of net blotch in Sardinian landraces of barley (Hordeum vulgare L.).

Monoconidial cultures of Pyrenophora teres, the causal agent of barley net blotch, were isolated from leaves collected from six populations of the barley landrace "S'orgiu sardu" growing in five agro-ecological areas of Sardinia, Italy, and genotyped using AFLPs. The 150 isolates were from lesions of either the "net form" (P. teres f. sp. teres) or the "spot form" (P. teres f. sp. maculata) of the disease. Of 121 AFLP markers, 42%, were polymorphic. Cluster analysis resolved the isolates into two strongly divergent groups (F(ST) = 0.79), corresponding to the net (45% of the isolates) and the spot (55% of the isolates) forms (designated the NFR and SFR groups, respectively). The absence of intermediate genotypes and the low number of shared markers between the two groups indicated that hybridization between the two formae is rare or absent under the field condition of Sardinia. Five of the barley populations hosted both forms but in different proportions. The SFR populations were similar in overall polymorphism to the NFR populations. However, compared to the SFR form, the NFR occurred in all fields sampled and showed a higher population divergence (F(ST) = 0.43 versus F(ST) = 0.09 with all isolates; F(ST) = 0.37 versus F(ST) = 0.06 with clone corrected samples) probably due to a lower migration rate. AFLP fingerprints resolved 117 distinct genotypes among the 150 isolates sampled (78%), 87% in SFR and 68% in NFR isolates. Although the absolute numbers may be a function of the number of AFLP markers assayed, the relative difference suggests that clonality is more prevalent among the NFR isolates (with 11 of 46 haplotypes observed more than once), compared with SFR isolates (7 of 71 haplotypes). Both digenic and multilocus linkage disequilibrium analyses suggested that sexual reproduction occurs at significant levels within the NFR and SFR populations, and that the relative contribution of sexual and asexual reproduction varies among different environments.

Fungi↗
PubMed2006

Mapping quantitative trait loci in chickpea associated with time to flowering and resistance to Didymella rabiei the causal agent of Ascochyta blight.

Drought is the major constraint to chickpea (Cicer arietinum L.) productivity worldwide. Utilizing early-flowering genotypes and advancing sowing from spring to autumn have been suggested as strategies for drought avoidance. However, Ascochyta blight (causal agent: Didymella rabiei (Kov.) v. Arx.) is a major limitation for chickpea winter cultivation. Most efforts to introgress resistance to the pathogen into Kabuli germplasm resulted in relatively late flowering germplasm. With the aim to explore the feasibility of combining earliness and resistance, RILs derived from a cross between a Kabuli cultivar and a Desi accession were evaluated under field conditions and genotyped with SSR markers. Three quantitative trait loci (QTLs) with significant effects on resistance were identified: two linked loci located on LG4 in epistatic interaction and a third locus on LG8. Two QTLs were detected for time to flowering: one in LG1 and another on LG2. When resistance and time to flowering were analyzed together, the significance of the resistance estimates obtained for the LG8 locus increased and the locus effect on days to flowering, previously undetected, was significantly different from zero. The identification of a locus linked both to resistance and time to flowering may account for the correlation observed between these traits in this and other breeding attempts.

Agriculture↗
PubMed2004

Public attitudes to depression in urban Turkey - the influence of perceptions and causal attributions on social distance towards individuals suffering from depression.

BACKGROUND: The aim of this study was to determine public attitudes towards patients with depression and the influence of perception and causal attributions on social distance towards individuals suffering from depression in urban areas. METHODS: This study was carried out with a representative sample in Istanbul which is the biggest metropolis in Turkey. Seven hundred and seven subjects completed the public survey form which consisted of ten items screening the demographic features and health status of the participants, and 32 items rating attitudes towards depression. RESULTS: The respondents' attitudes towards depression were very negative and nearly half of the subjects perceived people with depression as dangerous. More than half of the subjects stated that they would not marry a person with depression, and nearly half of the subjects stated that they would not rent their house to a person with depression. One-quarter of the subjects stated that depressive patients should not be free in the community. The subjects who considered depression as a disease and who believed that weakness of personality and social problems cause depression had negative attitudes towards depression. CONCLUSIONS: In Istanbul, people recognise depression well, but their attitudes towards it are fairly negative. The urban public has unfavourable attitudes towards depression and a tendency to isolate patients from the society. Notwithstanding the high prevalence, there is still considerable stigmatisation associated with depression.

Adolescent↗
PubMed2001

Renocortical expression of renin and of cyclooxygenase-2 in response to angiotensin II AT1 receptor blockade is closely coordinated but not causally linked.

Based on recent evidence that renin gene and cyclooxygenase-2 (COX-2) expression in the rat kidney cortex increase in parallel under a variety of conditions, this study aimed to characterize the causal linkage between COX-2 and renin expression. Therefore, we semi-quantitated renocortical renin and COX-2 gene expression when the renin-angiotensin system (RAS) was inhibited by the angiotensin II (Ang II) AT1 receptor antagonist candesartan (15 mg/kg per day) and when COX-2 activity was blocked by celecoxib (20 mg/kg twice a day) in three rat strains (Sprague-Dawley, WKY and SHR) at ages of 5, 9 and 15 weeks. We observed that candesartan increased renin mRNA in all rats at all ages, the amplitude of stimulation being inversely related to age. Candesartan increased COX-2 mRNA in all three strains at 5 weeks, and in SD and WKY rats also at 9 weeks. In 9-week-old SHR and in 15-week-old rats of all three strains candesartan did not influence COX-2 mRNA levels. For all rat strains, strain-specific strong linear correlations existed between renocortical COX-2 and renin mRNA levels, both with and without candesartan treatment. The additional feeding of candesartan-treated rats with celecoxib did not change renin mRNA or COX-2 mRNA levels, whilst the renal excretion of sodium and renal cortical prostaglandin E2 concentration decreased by 26% and 60%, respectively. In summary, these findings, obtained when the renin system was activated by AT1 receptor blockade, indicate that Ang II is not required to stimulate COX-2 expression and that COX-2 activity is not required to stimulate renin expression. However, the renocortical expression of renin and of COX-2 appear to be highly coordinated under basal conditions and during inhibition of RAS, suggesting the existence of a common denominator for renin and COX-2 expression that remains to be elucidated.

Angiotensin Receptor Antagonists↗
PubMed1999

Perceptual causality in the amodal completion of kinetic structures.

Perceptual causality as an amodal completion of kinetic structures was demonstrated. The experimental situation was as follows: a square appeared on the left, moved from left to right till it touched one side of a stationary rectangle (a perceptual screen), and disappeared; after a while, another square appeared at the other side of the rectangle and moved right. The first square moved faster than the second one. Sometimes, two moving objects were perceived, with an amodal launching effect: the first moving object seemed to collide with the second one behind the screen. When both the screen and the occluding interval were small, despite the discrepancy of velocities, a single moving object was perceived, but the object seemed to abruptly change its speed behind the screen. The perception of an amodal completion of movement raises some theoretical issues: the discrepancy between amodal completion of kinetic structures and that of static ones, the problem of perceptual identity, and figure-ground segregation in dynamic scene. The dilemma of the naive subject will also be discussed.

Humans↗
PubMed2002

Evidence of multiple causal sites affecting weight in the IGF2-INS-TH region of human chromosome 11.

The subtelomeric region of 11p harbours three closely linked genes, TH, INS and IGF2, that have been associated with obesity, size at birth, type I diabetes, polycystic ovary syndrome, overgrowth in Beckwith-Wiedemann syndrome and possibly hypertension. We have previously shown that the IGF2 ApaI single nucleotide polymorphism (SNP) associates with weight and body mass index in middle-aged Caucasian males but that there is no such association with the INS -23/ HphI site that marks INS 5' variable number of tandem repeats (VNTR) class I vs class III VNTR alleles. We report here the examination of three SNP markers in IGF2: 6815 A/T in the P1 promoter, AluI in exon 3 and ApaI in the 3' untranslated region (UTR), INS 5'VNTR class I alleles and the TH01 tetranucleotide microsatellite in a population sample. The analysis has taken into account the possibility that typing failure and the number of parameters required to model multiallelic loci could create spurious significance. We have exercised Hardy-Weinberg equilibrium tests, dichotomised multiallelic series to impose parsimony, and examined the data with failures modelled or excluded. Regression analysis infers that three markers, IGF2 ApaI, TH01 and subclasses of INS VNTR class I independently predict derived weight indices (combined P<10(-8) and accounting up to 2% of population weight variance), with no evidence of interaction. This establishes that there must be multiple causal sites impacting on weight in this genomic region.

Analysis of Variance↗
PubMed2004

Causal mechanisms underlying host specificity in bat ectoparasites.

In parasites, host specificity may result either from restricted dispersal capacity or from fixed coevolutionary host-parasite adaptations. Knowledge of those proximal mechanisms leading to particular host specificity is fundamental to understand host-parasite interactions and potential coevolution of parasites and hosts. The relative importance of these two mechanisms was quantified through infection and cross-infection experiments using mites and bats as a model. Monospecific pools of parasitic mites (Spinturnix myoti and S. andegavinus) were subjected either to individual bats belonging to their traditional, native bat host species, or to another substitute host species within the same bat genus (Myotis). The two parasite species reacted differently to these treatments. S. myoti exhibited a clear preference for, and had a higher fitness on, its native host, Myotis myotis. In contrast, S. andegavinus showed no host choice, although its fitness was higher on its native host M. daubentoni. The causal mechanisms mediating host specificity can apparently differ within closely related host-parasite systems.

Animals↗
PubMed2004

The perception of causality in chimpanzees (Pan spp.).

Chimpanzees (Pan spp.) were tested on a habituation/dishabituation paradigm that was originally developed to test for comprehension of causality in very young human infants. Three versions of the test were used: a food item being moved by a hand, a human pushing another human off a chair to obtain a food item, and a film clip of natural chimpanzee behaviour (capturing and eating a monkey). Chimpanzees exhibited similar results to those obtained with human infants, with significantly elevated levels of looking on the dishabituation trials. Since the level of response was significantly greater on natural/unnatural sequences than on unnatural/natural sequences, we conclude that the chimpanzees were not responding just to novelty but rather to events that infringed their sense of natural causation.

Animals↗
PubMed1989

Suppression of male-specific cytochrome P450 2c and its mRNA by 3,4,5,3',4',5'-hexachlorobiphenyl in rat liver is not causally related to changes in serum testosterone.

Rat cytochrome P450 2c (P450 gene IIC11) is a constitutive, male-specific hepatic enzyme which is suppressed greater than 90% by treatment with 3,4,5,3',4',5'-hexachlorobiphenyl (HCB) [H. N. Yeowell et al. (1987) Mol. Pharmacol. 32, 340-347]. HCB also decreases serum testosterone levels in adult male rats (greater than 98% loss). The present study assesses whether the suppression of P450 2c by HCB is a direct result of its effects on serum testosterone levels. Further, the site along the hypothalamic-pituitary-testicular axis at which HCB acts to depress testosterone secretion was examined. Administration of the synthetic androgen methyltrienolone to HCB-treated rats failed to prevent the suppression of P450 2c mRNA and its associated microsomal steroid 16 alpha-hydroxylase activity under conditions where it effectively reversed the large decrease in P450 2c mRNA and steroid 16 alpha-hydroxylase activity produced by castration. Hepatic steroid 6 beta-hydroxylase activity, which is catalyzed primarily by P450 2a (P450 gene IIIA2), was also suppressed by HCB and was not protected by methyltrienolone. Administration of either human chorionic gonadotropin, an analog of pituitary-derived luteinizing hormone, or the hypothalamic luteinizing hormone releasing hormone elevated serum testosterone levels to a much smaller extent in HCB-treated rats than in control rats. These results indicate that the effects of HCB on serum testosterone levels reflect its effects on testicular function rather than the pituitary or hypothalamus. However, the present study demonstrates that the consequential reduction in serum testosterone levels in HCB-treated rats is not causally related to the reduction in hepatic P450 2c levels. Thus, HCB must also act on some other regulatory mechanism involved in the expression of this protein.

Animals↗
PubMed1994

Causal factors in spinal cord injury: patients' evolving perceptions and association with depression.

Do spinal cord injured patients who accept responsibility for their injury cope better than those who blame others? Previous investigations have yielded conflicting answers to this question. On the assumption that some portion of the disparity in earlier findings derives from the failure of early investigators to conceptualize "blame" as a dynamic phenomenon, the present study approached the question via a longitudinal study. Specifically, we examined: (1) the evolution of patients' perceptions of responsibility for spinal cord injury, and (2) the changing association of this factor with depression over a 2-year period, beginning with inpatient rehabilitation. Eighteen men with traumatic spinal cord injury were evaluated during acute rehabilitation and again at 18 to 24 months following discharge. Patients assigned proportions of blame for their injury to four possible causal factors (self, environment, chance, others). Three indices of depression were derived from the Beck Depression Inventory (BDI). Eighty-nine percent of the subjects displayed shifts in pattern of blame assignment between initial and follow-up evaluations. Individuals whose self-blame score increased over time exhibited increased depression, as did those who came to attribute to "chance" lesser blame for their injury. During inpatient rehabilitation, no aspect of blame correlated significantly with any of the three BDI indices, although "other blame" and the cognitive/affective BDI index just failed to reach conventional levels (r = .43, p = .07). By contrast, at follow-up evaluation, "self blame" was positively correlated with both the cognitive/affective (r = .51, p = .03) and Total (r = .46, p = .05) BDI scores. All other correlations were not statistically meaningful.(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗
PubMed1995

Comments on the crusade against the causal efficacy of human thought.

Hawkins reiterates the familiar behavioristic doctrine that psychology should banish factors that cannot be directly observed. He seems to be unaware that the very operant theory he is espousing is heavily invested in internal determinants that do not lend themselves to direct observation. Because behavior is often unaffected by its immediate situational antecedents and consequences, operant analysts are turning increasingly to internalized determinants of behavior, such as the residues of past reinforcements. These internalized determinants are not directly observable or measurable. They are inferred organismic states. Hawkins invokes the standard behavioristic arguments that, like other cognitive events, beliefs of personal efficacy are epiphenomenal by-products of conditioned responses. The paradigms used to verify the causal contribution of efficacy beliefs to performance renders this claim empirically baseless. Efficacy beliefs are systematically raised to differential levels by means that involve no performances or by bogus feedback that is either unrelated to performance or is contrary to performance. In none of these paradigms are instated efficacy beliefs reflections of performance, but they are uniformly good predictors of subsequent performance. Epiphenomenal assertions are self-destruct arguments.

Adaptation, Psychological↗
PubMed1988

Causal relationship between the transitions in the core and the surface in porcine low-density lipoproteins.

Two independent parameters, two characteristic temperatures, one indicating the change in the molecular organization of the core, Tc, and the other in the surface layer, Ts, were measured for a number of natural and triglyceride-enriched porcine low-density lipoprotein (LDL1 (buoyant density 1.020--1.063 g/ml) and LDL2 (buoyant density 1.063--1.080 g/ml) samples. Tc was determined by differential scanning calorimetry (DSC), whereas Ts was measured by Mn(II) binding to the lipoprotein surface followed by electron spin resonance (ESR) spectroscopy. A significant causal relationship between Tc and Ts in both LDL subfractions demonstrates the surface-core interaction in LDL. The significance of that interaction is emphasized as a possible link in the chain diet----lipoprotein changes----atherosclerosis.

Animals↗