The Parvidrilidae – a diversified groundwater family: description of six new species from southern Europe,and clues for its phylogenetic position within Clitellata (Annelida)

The Parvidrilidae Erséus, 1999 constitute the most recently described family of oligochaete microdriles. Prior to this study, Parvidrilus strayeri Erséus, 1999, and Parvidrilus spelaeus Martínez‐Ansemil, Sambugar & Giani, 2002, found in groundwaters of the USA (Alabama) and Europe (Slovenia and Italy), respectively, were the only two species in this family. In this paper, six new species – Parvidrilus camachoi , Parvidrilus gianii , Parvidrilus jugeti , Parvidrilus meyssonnieri , Parvidrilus stochi , and Parvidrilus tomasini – and Parvidrilus gineti (Juget, 1959) comb. nov. are added to the family. With all species being stygobiont, the Parvidrilidae is unique in being the only family of oligochaetes worldwide comprising taxa that are restricted to groundwater habitats. Parvidrilids are exceedingly small worms whose principal morphological characteristics are the presence of hair setae in ventral bundles, the markedly posterior position of setae within the segments, the presence of mid‐dorsal glandular pouches in mesosomial segments, the lateral development of the clitellum, the presence of a single male pore in segment XII, and the presence (or absence) of a single spermatheca. The phylogenetic relationships of the Parvidrilidae within the Clitellata were investigated using the nuclear 18S rRNA gene, and the most representative and taxonomically balanced data set of clitellate families available to date. The data were analysed by parsimony, maximum likelihood, and Bayesian inference. Irrespective of the method used, Parvidrilidae were placed far from Capilloventridae, one family once suggested to be closely related to parvidrilids. Although closer to Enchytraeidae than Phreodrilidae, two other suggested putative sister families, the exact position of Parvidrilidae within Clitellata still remained uncertain in the absence of branch support. The examination of reproductive structures, together with the similarity of other important anatomical traits of the new species herein described, reinforced the idea that phreodrilids were the best candidate to be the sister group to parvidrilids on morphological grounds. A fragment of the mitochondrial cytochrome oxidase I gene, used as a barcode, also genetically characterized a few Parvidrilus species. The observation that two species diverge from each other by high genetic distances, even though their type localities are more or less only 100 km apart, is interpreted in the context of low dispersal abilities of inhabitants of the subterranean aquatic ecosystem, and habitat heterogeneity. The Parvidrilidae appear to be a diversified, Holarctic, and probably widely distributed family in groundwater, but very often overlooked because of the small size and external similarity with the polychaete family Aeolosomatidae of its members. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 530–558.     

Driving forces of soil organic carbon evolution at the landscape and regional scale using data from a stratified soil monitoring

Soil monitoring programmes face significant challenges as there is an important trade‐off between detecting significant changes in soil properties on the one hand (which can be achieved by minimizing variability by higher sampling density or stratification approaches), and identifying the driving forces responsible for these changes on the other hand (which requires enough variability). This study aims to reconcile these two objectives by identifying the driving forces of soil organic carbon (SOC) evolution over a long period, based on an extensive but stratified soil monitoring programme. Data at both the finest level (questionnaires to the farmers) and the large scale (agricultural census, climate and soil databases for southern Belgium) were used in a cluster analysis, multiple linear regressions and mixed odels in order to discriminate between the driving forces involved. Results indicated that the negative ‘baseline effect’ (i.e. the inversely proportional effect of the initial SOC content on the SOC evolution) was responsible for an important part of the SOC variability. Consequently, the systems are not at steady state when starting the observations, although this assumption is used by most SOC dynamic models. Moreover, the baseline effect resulted in a trend of the soils to converge towards a regional SOC stock which significantly differed according to land use (36.4 t C ha^?1 for the plough depth of cropland and 92.2 t C ha^?1 for the 0–30 cm layer of grassland). Despite this strong effect, the main driving forces of the SOC decrease of cropland (?0.2 t C ha^?1 yr^?1) and SOC increase of grassland (+0.2 t C ha^?1 yr^?1) over a period of 50 years were discriminated. The agricultural management (cropland) and the clay content (grassland), together with the change in precipitation (to a lesser degree for cropland) were highlighted as the predominant factors involved in SOC evolution, when land use change is excluded. The use of questionnaires allowed to better understanding the impact of an intensive agricultural management on the SOC content, as the lowest SOC stocks were associated to the most intensively managed fields. The mixed models partly succeeded in predicting SOC evolution as they presented still large uncertainties after validation (mean error from 3% to 25%, root mean square error of prediction from 21% to 242%). While SOC monitoring schemes are increasingly being implemented, our results will likely apply to those using a similar design. It was shown that this strategy succeeded to reconcile both the SOC change detection and the distinction of the driving forces involved at the regional scale.     

Climatic niche and neutral genetic diversity of the six Iberian pine species: a retrospective and prospective view

Quaternary climatic fluctuations have left contrasting historical footprints on the neutral genetic diversity patterns of existing populations of different tree species. We should expect the demography, and consequently the neutral genetic structure, of taxa less tolerant to particular climatic extremes to be more sensitive to long‐term climate fluctuations. We explore this hypothesis here by sampling all six pine species found in the Iberian Peninsula (2464 individuals, 105 populations), using a common set of chloroplast microsatellite markers, and by looking at the association between neutral genetic diversity and species‐specific climatic requirements. We found large variation in neutral genetic diversity and structure among Iberian pines, with cold‐enduring mountain species (Pinus uncinata, P. sylvestris and P. nigra) showing substantially greater diversity than thermophilous taxa (P. pinea and P. halepensis). Within species, we observed a significant positive correlation between population genetic diversity and summer precipitation for some of the mountain pines. The observed pattern is consistent with the hypotheses that: (i) more thermophilous species have been subjected to stronger demographic fluctuations in the past, as a consequence of their maladaptation to recurrent glacial cold stages; and (ii) altitudinal migrations have allowed the maintenance of large effective population sizes and genetic variation in cold‐tolerant species, especially in more humid regions. In the light of these results and hypotheses, we discuss some potential genetic consequences of impending climate change.     

Eutrophication and macroalgal blooms in temperate and tropical coastal waters: nutrient enrichment experiments with Ulva spp.

Receiving coastal waters and estuaries are among the most nutrient‐enriched environments on earth, and one of the symptoms of the resulting eutrophication is the proliferation of opportunistic, fast‐growing marine seaweeds. Here, we used a widespread macroalga often involved in blooms, Ulva spp., to investigate how supply of nitrogen (N) and phosphorus (P), the two main potential growth‐limiting nutrients, influence macroalgal growth in temperate and tropical coastal waters ranging from low‐ to high‐nutrient supplies. We carried out N and P enrichment field experiments on Ulva spp. in seven coastal systems, with one of these systems represented by three different subestuaries, for a total of nine sites. We showed that rate of growth of Ulva spp. was directly correlated to annual dissolved inorganic nitrogen (DIN) concentrations, where growth increased with increasing DIN concentration. Internal N pools of macroalgal fronds were also linked to increased DIN supply, and algal growth rates were tightly coupled to these internal N pools. The increases in DIN appeared to be related to greater inputs of wastewater to these coastal waters as indicated by high δ¹⁵N signatures of the algae as DIN increased. N and P enrichment experiments showed that rate of macroalgal growth was controlled by supply of DIN where ambient DIN concentrations were low, and by P where DIN concentrations were higher, regardless of latitude or geographic setting. These results suggest that understanding the basis for macroalgal blooms, and management of these harmful phenomena, will require information as to nutrient sources, and actions to reduce supply of N and P in coastal waters concerned.     

Use of a crude extract or purified antigen from first‐instar cattle grubs,Hypoderma lineatum,for the detection of anti‐Hypoderma antibodies in free‐ranging cervids from southern Spain

During the 2003–2005 hunting seasons, a total of 120 Cervidae, including 39 red deer (Cervus elaphus hispanicus) and 81 fallow deer (Dama dama), were examined for subcutaneous myiasis. Animals were shot from January to June in southern Spain. Specific antibodies against Hypodermatinae (Diptera: Oestridae) were detected by indirect enzyme‐linked immunosorbent assay (iELISA) using a crude larval extract (CLE) and a purified antigen [hypodermin C (HC)] obtained from first instars of Hypoderma lineatum (De Villers) (Diptera: Oestridae). Hypoderma actaeon Brauer was the only species detected in this study, which represents the first confirmation of this species in fallow deer from Spain. The overall prevalence of animals presenting subcutaneous larvae (14.2%) was considerably lower than the prevalences determined by iELISA with CLE (43.3%) and HC (40.0%). Red deer showed a higher prevalence of Hypoderma than fallow deer. The concordance between larval examination during the hunting season and iELISA using both antigens was low, whereas the concordance between the CLE and HC ELISAs was good. Larval antigens obtained from H. lineatum constitute a good tool for the diagnosis of H. actaeon in Cervidae, especially when the hunting season does not coincide with the maximum presence of larvae on the back.     

Behavioural plasticity induced by intraspecific competition in host orientation in a parasitoid

1. Accurate measurement of external conditions is fundamental for survival. For parasitoids, in particular, sensing the environmental conditions is key because they are short‐lived animals that must acquire information shortly after emergence. 2. This study investigated whether conspecifics during larval growth can influence and modify the decision to orient to different quality hosts in a parasitoid with an active host‐seeking larva. How the density of conspecifics during growth modifies these decisions was also studied. 3. When larvae were submitted to increases in the intensity of pre‐parasitism competition and then offered different host odours, they increased the orientation to poor‐quality hosts likewise. It was also found that this behaviour is general to orientation to hosts in different physiological states. 4. These results show that pre‐parasitism competition can influence and modulate orientation to poor‐quality hosts when high‐quality hosts are not available.     

Impact of HIV Comprehensive Care and Treatment on Serostatus Disclosure among Cameroonian Patients in Rural District Hospitals

This work aimed to analyze the rate of disclosure to relatives and friends over time and to identify factors affecting disclosure among seropositive adults initiating antiretroviral therapy (ART) in rural district hospitals in the context of decentralized, integrated HIV care and task-shifting to nurses in Cameroon. Stratall was a 24-month, randomized, open-label trial comparing the effectiveness of clinical monitoring alone with laboratory plus clinical monitoring on treatment outcomes. It enrolled 459 HIV-infected ART-naive adults in 9 rural district hospitals in Cameroon. Participants in both groups were sometimes visited by nurses instead of physicians. Patients with complete data both at enrolment (M0) and at least at one follow-up visit were included in the present analysis. A mixed Poisson regression was used to estimate predictors of the evolution of disclosure index over 24 months (M24).The study population included 385 patients, accounting for 1733 face-to-face interviews at follow-up visits from M0 to M24. The median [IQR] number of categories of relatives and friends to whom patients had disclosed was 2 [1]–[3] and 3 [2]–[5] at M0 and M24 (p-trend<0.001), respectively. After multiple adjustments, factors associated with disclosure to a higher number of categories of relatives and friends were as follows: having revealed one’s status to one’s main partner, time on ART, HIV diagnosis during hospitalization, knowledge on ART and positive ratio of follow-up nurse-led to physician-led visits measuring task-shifting. ART delivered in the context of decentralized, integrated HIV care including task-shifting was associated with increased HIV serological status disclosure.     

Xenopatients 2.0: Reprogramming the epigenetic landscapes of patient-derived cancer genomes

In the science-fiction thriller film Minority Report, a specialized police department called “PreCrime” apprehends criminals identified in advance based on foreknowledge provided by 3 genetically altered humans called “PreCogs”. We propose that Yamanaka stem cell technology can be similarly used to (epi)genetically reprogram tumor cells obtained directly from cancer patients and create self-evolving personalized translational platforms to foresee the evolutionary trajectory of individual tumors. This strategy yields a large stem cell population and captures the cancer genome of an affected individual, i.e., the PreCog-induced pluripotent stem (iPS) cancer cells, which are immediately available for experimental manipulation, including pharmacological screening for personalized “stemotoxic” cancer drugs. The PreCog-iPS cancer cells will re-differentiate upon orthotopic injection into the corresponding target tissues of immunodeficient mice (i.e., the PreCrime-iPS mouse avatars), and this in vivo model will run through specific cancer stages to directly explore their biological properties for drug screening, diagnosis, and personalized treatment in individual patients. The PreCog/PreCrime-iPS approach can perform sets of comparisons to directly observe changes in the cancer-iPS cell line vs. a normal iPS cell line derived from the same human genetic background. Genome editing of PreCog-iPS cells could create translational platforms to directly investigate the link between genomic expression changes and cellular malignization that is largely free from genetic and epigenetic noise and provide proof-of-principle evidence for cutting-edge “chromosome therapies” aimed against cancer aneuploidy. We might infer the epigenetic marks that correct the tumorigenic nature of the reprogrammed cancer cell population and normalize the malignant phenotype in vivo. Genetically engineered models of conditionally reprogrammable mice to transiently express the Yamanaka stemness factors following the activation of phenotypic copies of specific cancer diseases might crucially evaluate a “reprogramming cure” for cancer. A new era of xenopatients 2.0 generated via nuclear reprogramming of the epigenetic landscapes of patient-derived cancer genomes might revolutionize the current personalized translational platforms in cancer research.