133 research outputs found
Lateral optic flow does not influence distance estimation in the desert ant Cataglyphis fortis.
The present account answers the question of whether desert ants (Cataglyphis fortis) gauge the distance they have travelled by using self-induced lateral optic-flow parameters, as has been described for bees. The ants were trained to run to a distant food source within a channel whose walls were covered with black-and-white gratings. From the food source, they were transferred to test channels of double or half the training width, and the distance they travelled before searching for home and their walking speeds were recorded. Since the animals experience different motion parallax cues when walking in the broader or narrower channels, the optic-flow hypothesis predicted that the ants would walk faster and further in the broader channels, but more slowly and less far in the narrower channels. In contrast to this expectation, neither the walking speeds nor the searching distances depended on the width or height of the channels or on the pattern wavelengths. Even when ventral-field visual cues were excluded by covering the eyes with light-tight paint, the ants were not influenced by lateral optic flow-field cues. Hence, walking desert ants do not depend on self-induced visual flow-field cues in gauging the distance they have travelled, as do flying honeybees, but can measure locomotor distance exclusively by idiothetic means
Misdiagnosis of familial Mediterranean fever in patients with Anderson-Fabry disease
Fabry disease (FD) is an underdiagnosed pathology due to its symptomatology that
overlaps with various systemic and rheumatic disorders, including familial
Mediterranean fever (FMF). We examined the Mediterranean fever (MEFV) and
α-galactosidase A (GLA) genes, whose mutations are responsible for FMF and FD,
respectively, in 42 unrelated patients diagnosed with FMF, which revealed
significant ambiguity regarding some of the symptoms which are also present in
FD. The objective of this study was to determine the spectrum of mutations
present in these genes, in order to identify cases of mistaken diagnosis of FMF
and/or missed diagnosis of FD. Ten out of 42 patients had one mutation in
homozygosis or two different mutations in heterozygosis in the MEFV gene; 20/42
had a single heterozygous mutation, and 12/42 did not have genetic alterations in
MEFV. The analysis of the GLA gene conducted on all the samples revealed that
three subjects, and some members of their families, had two different exonic
mutations associated with FD. Family studies allowed us to identify eight other
cases of FD, bringing the total undiagnosed subjects to 11/53. Analyzing the MEFV
and GLA genes in patients with clinical diagnoses of FMF proved to be
fundamentally important for the reduction of diagnostic errors
Disease activity states, reasons for discontinuation and adverse events in 1038 Italian children with juvenile idiopathic arthritis treated with etanercept
The advent of biologic medications has increased considerably the potential for treatment benefit in juvenile idiopathic arthritis (JIA), with clinical remission being now achievable in a substantial proportion of patients. However, there is a need of data from the real world of clinical practice to evaluate thoroughly the efficacy and safety profile of the biologic agents currently approved
Do Fleas Affect Energy Expenditure of Their Free-Living Hosts?
Parasites can cause energetically costly behavioural and immunological responses which potentially can reduce host fitness. However, although most laboratory studies indicate that the metabolic rate of the host increases with parasite infestation, this has never been shown in free-living host populations. In fact, studies thus far have shown no effect of parasitism on field metabolic rate (FMR).We tested the effect of parasites on the energy expenditure of a host by measuring FMR using doubly-labelled water in free-living Baluchistan gerbils (Gerbillus nanus) infested by naturally occurring fleas during winter, spring and summer. We showed for the first time that FMR of free-living G. nanus was significantly and positively correlated with parasite load in spring when parasite load was highest; this relationship approached significance in summer when parasite load was lowest but was insignificant in winter. Among seasons, winter FMRs were highest and summer FMRs were lowest in G. nanus.The lack of parasite effect on FMR in winter could be related to the fact that FMR rates were highest among seasons. In this season, thermoregulatory costs are high which may indicate that less energy could be allocated to defend against parasites or to compensate for other costly activities. The question about the cost of parasitism in nature is now one of the major themes in ecological physiology. Our study supports the hypothesis that parasites can elevate FMR of their hosts, at least under certain conditions. However, the effect is complex and factors such as season and parasite load are involved
Pontine tegmental cap dysplasia: developmental and cognitive outcome in three adolescent patients
Pontine Tegmental Cap Dysplasia (PTCD) is a recently described, rare disorder characterized by a peculiar cerebellar and brainstem malformation. Nineteen patients have been reported to date, of which only one in the adolescent age, and data on the clinical, cognitive and behavioural outcome of this syndrome are scarce
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