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1.
J Fish Biol ; 85(5): 1603-16, 2014 Nov.
Artículo en Inglés | MEDLINE | ID: mdl-25270290

RESUMEN

Selectivity of recreational angling on fish behaviour was studied by examining whether capture order or lure type (natural v. artificial bait) in ice-fishing could explain behavioural variation among perch Perca fluviatilis individuals. It was also tested if individually assessed personality predicts fish behaviour in groups, in the presence of natural predators. Perca fluviatilis showed individually repeatable behaviour both in individual and in group tests. Capture order, capture method, condition factor or past growth rate did not explain variation in individual behaviour. Individually determined boldness as well as fish size, however, were positively associated with first entrance to the predator zone (i.e. initial risk taking) in group behaviour tests. Individually determined boldness also explained long-term activity and total time spent in the vicinity of predators in the group. These findings suggest that individual and laboratory-based boldness tests predict boldness of P. fluviatilis in also ecologically relevant conditions, i.e. in shoals and in the presence of natural predators. The present results, however, also indicate that the above-mentioned two angling methods may not be selective for certain behavioural types in comparison to each other.


Asunto(s)
Conducta Animal , Ecosistema , Percas/fisiología , Personalidad , Animales , Finlandia , Actividades Humanas , Lagos , Conducta Predatoria
2.
J Evol Biol ; 27(9): 1930-8, 2014 Sep.
Artículo en Inglés | MEDLINE | ID: mdl-25056484

RESUMEN

Phenotype-linked fertility hypothesis (PLFH) predicts that male secondary sexual traits reveal honest information about male fertilization ability. However, PLFH has rarely been studied in humans. The aim of the present study was to test PLFH in humans and to investigate whether potential ability to select fertile partners is independent of sex or cultural background. We found that on the contrary to the hypothesis, facial masculinity was negatively associated with semen quality. As increased levels of testosterone have been demonstrated to impair sperm production, this finding may indicate a trade-off between investments in secondary sexual signalling (i.e. facial masculinity) and fertility or status-dependent differences in investments in semen quality. In both sexes and nationalities (Spanish and Colombian), ranked male facial attractiveness predicted male semen quality. However, Spanish males and females estimated facial images generally more attractive (gave higher ranks) than Colombian raters, and in both nationalities, males gave higher ranks than females. This suggests that male facial cues may provide culture- and sex-independent information about male fertility. However, our results also indicate that humans may be more sensitive to facial attractiveness cues within their own populations and also that males may generally overestimate the attractiveness of other men to females.


Asunto(s)
Cara , Masculinidad , Análisis de Semen , Adulto , Colombia , Señales (Psicología) , Características Culturales , Femenino , Humanos , Masculino , Fenotipo , Análisis de Regresión , España , Adulto Joven
3.
Bull Entomol Res ; 100(3): 279-85, 2010 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-19698197

RESUMEN

The deer ked (Lipoptena cervi) can fail in its host search. Host search fails when an individual deer ked irreversibly accepts a host unsuitable for its reproduction (e.g. a human) and drops its wings. In northern Europe, the main host of the deer ked is the moose (Alces alces). The deer ked is increasingly causing serious problems for humans (for example, causing deer ked dermatitis) and is considered a threat for the recreational use of forests. The adult deer ked flies in early and mid-autumn to search for a host. Our aims were: (i) to study whether there are ways to avoid deer ked attacks by wearing particular clothing, and (ii) to evaluate deer ked host choice. Using human targets, we explored the cues the deer ked uses for host selection. We studied which part of the host body deer keds target and if body colour and temperature affect their choice. In our experiments, deer keds landed more on dark and red clothing than on white clothing. Moreover, deer keds mostly attacked the upper body parts and preferred the back side of the body over the front side. Finally, deer keds preferred the warmest areas of the host.


Asunto(s)
Conducta Animal/fisiología , Color , Ciervos/parasitología , Dípteros/fisiología , Infestaciones Ectoparasitarias/prevención & control , Cuerpo Humano , Temperatura , Animales , Vestuario , Interacciones Huésped-Parásitos , Humanos
4.
Int J Obes (Lond) ; 32(2): 292-303, 2008 Feb.
Artículo en Inglés | MEDLINE | ID: mdl-17848939

RESUMEN

OBJECTIVE: Lifestyle and genetic factors interact in the development of obesity and the metabolic syndrome. The molecular mechanisms underlying the beneficial dietary modifications are, however, unclear. We aimed to examine the effect of the long-term moderate weight reduction on gene expression in adipose tissue (AT) and to identify genes and gene clusters responsive to treatment and thereby likely contributing to the development of the metabolic syndrome. DESIGN: Randomized controlled and individualized weight reduction intervention. SUBJECTS: Forty-six subjects with impaired fasting glycemia or impaired glucose tolerance and features of metabolic syndrome, aged 60+/-7 years were randomized either to a weight reduction (WR) (n=28) or a control (n=18) group lasting for 33 weeks. MEASUREMENTS: Oral and intravenous glucose tolerance tests and subcutaneous AT biopsies were performed before and after the intervention. Gene expression of AT was studied using microarray technology in subgroups of WR (with weight reduction > or =5%, n=9) and control group (n=10). The results were confirmed using quantitative PCR. RESULTS: In the WR group, glucose metabolism improved. Moreover, an inverse correlation between the change in S (I) and the change in body weight was found (r=-0.44, P=0.026). Downregulation of gene expression (P<0.01) involving gene ontology groups of extracellular matrix and cell death was seen. Such changes did not occur in the control group. The tenomodulin-gene was one of the most downregulated genes (-39+/-16%, P<0.0001). Moreover, its expression correlated with insulin sensitivity (r=-0.34, P=0.005) before the intervention and with body adiposity both before (r=0.42, P=0.007) and after (r=0.30, P=0.056) the intervention. CONCLUSION: Genes regulating the extracellular matrix and cell death showed a strong downregulation after long-term weight reduction. This likely reflects a new stable state at the molecular level in AT. Further studies are warranted to elucidate the mechanisms of these genetic factors.


Asunto(s)
Glucemia/metabolismo , Matriz Extracelular/genética , Insulina/metabolismo , Síndrome Metabólico/genética , Obesidad/genética , Pérdida de Peso/genética , Adulto , Anciano , Estudios de Casos y Controles , Muerte Celular/genética , Femenino , Regulación de la Expresión Génica , Prueba de Tolerancia a la Glucosa , Humanos , Masculino , Persona de Mediana Edad , Obesidad/dietoterapia
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