The drivers of species co-existence in local communities are especially enigmatic for assemblages of morphologically cryptic species. Here we characterize the colonization dynamics and abundance of ...nine species of Caenorhabditis nematodes in neotropical French Guiana, the most speciose known assemblage of this genus, with resource use overlap and notoriously similar external morphology despite deep genomic divergence.
To characterize the dynamics and specificity of colonization and exploitation of ephemeral resource patches, we conducted manipulative field experiments and the largest sampling effort to date for Caenorhabditis outside of Europe. This effort provides the first in-depth quantitative analysis of substrate specificity for Caenorhabditis in natural, unperturbed habitats.
We amassed a total of 626 strain isolates from nine species of Caenorhabditis among 2865 substrate samples. With the two new species described here (C. astrocarya and C. dolens), we estimate that our sampling procedures will discover few additional species of these microbivorous animals in this tropical rainforest system. We demonstrate experimentally that the two most prevalent species (C. nouraguensis and C. tropicalis) rapidly colonize fresh resource patches, whereas at least one rarer species shows specialist micro-habitat fidelity.
Despite the potential to colonize rapidly, these ephemeral patchy resources of rotting fruits and flowers are likely to often remain uncolonized by Caenorhabditis prior to their complete decay, implying dispersal-limited resource exploitation. We hypothesize that a combination of rapid colonization, high ephemerality of resource patches, and species heterogeneity in degree of specialization on micro-habitats and life histories enables a dynamic co-existence of so many morphologically cryptic species of Caenorhabditis.
Background
In France, psoriasis is a chronic inflammatory skin disease. For several years now, particular attention has been given to the quality of life (Qol) of psoriasis patients. Sexual ...dysfunction (SD) defined as not wanting or enjoying sexual experience is an important component of Qol. Psoriasis through its physical symptoms and psychological consequences can thus be responsible for SD.
Method
The survey participants were recruited through the national psoriasis dermatitis patient association.
Result
41% (577) patients reported having SD related to their psoriasis. Women reported significantly more SD than men (387 44.7% vs. 190 35%, p < 0.001). For 396 (28.1%) patients SD due to their psoriasis manifested as a reduction in the frequency of sexual activity, for 207 (14.7%) as change in their sexual practice, and for 284 (27.4%) as an absence of sexual activity without significant difference between women and men. The main consequence of sexual difficulties for patients was loss of self‐confidence in 627 (44.5%) cases, guilt in 209 (14.8%) cases, couple life impairment in 214 (15.2%) cases, isolation in 260 (18.5%) cases and frustration.
Discussion
In this study investigating SD related to psoriasis, we found that the disease impact sexual relations of 41% of patients of both gender. The main causes of SD were both physical alone and psychological alone, in the same proportions. The physical symptoms of psoriasis are therefore not the only ones responsible for the sexual discomfort reported from patients in their sexual relations. This may be due to a discomfort of the patient or the physician when talking about sexuality because they can't find the terms to talk about this subject often considered taboo and the age or gender difference. This aspect of the disease should be considered by physicians who care for patients with psoriasis, especially dermatologists. Finally, other strategies should be implemented, such as patient talk groups, referral guides or personalised therapeutic education.
Sexual dysfunction defined as not wanting or enjoying sexual experience is an important component of quality of life Psoriasis through its physical symptoms and psychological consequences can thus be responsible for Sexual dysfunction.
Little is known about phototype and the response to systemic treatment in psoriasis.
To assess the characteristics of psoriasis, the therapeutic choice and its efficacy according to phototype.
We ...included patients from the PsoBioTeq cohort initiating a first biologic. Patients were classified according to their phototype. The evaluation included disease characteristics, choice of the initial biologic and therapeutic response at 12 months based on PASI 90 and DLQI 0/1.
Of the 1400 patients included, 423 (30.2%), 904 (64.6%) and 73 (5.2%) were in the phototype I-II, III-IV and V-VI groups, respectively. The V-VI group had a higher initial DLQI, more frequently initiated ustekinumab. Patients in the phototype V-VI group maintained the first sequence of biologic as the other phototype groups, even though the proportion of patients reaching the PASI 90 and DLQI 0/1 at 12 months was lower in this group than other groups.
Patient phototype seems associated with quality of life and choice of the initial biologic in psoriasis. Phototype V-VI group less frequently switched treatments than did the other groups when the response was not efficient.
We report on the sexual disorders common in patients with psoriasis, and examine the underlying reasons, including the use of psoriasis treatments that can result in sexual difficulties.
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