Molecular evidence for broad-scale distributions in bdelloid rotifers: everything is not everywhere but most things are very widespread

The Baas-Becking's hypothesis, also known by the term 'everything is everywhere' (EisE), states that microscopic organisms such as bacteria and protists are globally distributed and do not show biogeographical patterns, due to their high dispersal potential. We tested the prediction of the EisE hypothesis on bdelloid rotifers, microscopic animals similar to protists in size and ecology that present one of the best cases among animals for the plausibility of global dispersal. Geographical range sizes and patterns of isolation by distance were estimated for global collections of the genera Adineta and Rotaria, using different taxonomic units: (i) traditional species based on morphology, (ii) the most inclusive monophyletic lineages from a cytochrome oxidase I phylogeny comprising just a single traditional species, and (iii) genetic clusters indicative of independently evolving lineages. Although there are cases of truly cosmopolitan distribution, even at the most finely resolved taxonomic level, most genetic clusters are distributed at continental or lower scales. Nevertheless, although 'everything is not everywhere', bdelloid rotifers do display broad distributions typical of those of other microscopic organisms. Broad dispersal and large population sizes might be factors lessening the evolutionary cost of long-term abstinence from sexual reproduction in this famous group of obligate parthenogens.     

IMPlementation of A Relatives’ Toolkit (IMPART study): an iterative case study to identify key factors impacting on the implementation of a web-based supported self-management intervention for relatives of people with psychosis or bipolar experiences in a National Health Service: a study protocol

Background

Web-based interventions to support people to manage long-term health conditions are available and effective but rarely used in clinical services. The aim of this study is to identify critical factors impacting on the implementation of an online supported self-management intervention for relatives of people with recent onset psychosis or bipolar disorder into routine clinical care and to use this information to inform an implementation plan to facilitate widespread use and inform wider implementation of digital health interventions.

Methods

A multiple case study design within six early intervention in psychosis (EIP) services in England, will be used to test and refine theory-driven hypotheses about factors impacting on implementation of the Relatives’ Education And Coping Toolkit (REACT). Qualitative data including behavioural observation, document analysis, and in-depth interviews collected in the first two EIP services (wave 1) and analysed using framework analysis, combined with quantitative data describing levels of use by staff and relatives and impact on relatives’ distress and wellbeing, will be used to identify factors impacting on implementation. Consultation via stakeholder workshops with staff and relatives and co-facilitated by relatives in the research team will inform development of an implementation plan to address these factors, which will be evaluated and refined in the four subsequent EIP services in waves 2 and 3. Transferability of the implementation plan to non-participating services will be explored.

Discussion

Observation of implementation in a real world clinical setting, across carefully sampled services, in real time provides a unique opportunity to understand factors impacting on implementation likely to be generalizable to other web-based interventions, as well as informing further development of implementation theories. However, there are inherent challenges in investigating implementation without influencing the process under observation. We outline our strategies to ensure our design is transparent, flexible, and responsive to the timescales and activities happening within each service whilst also meeting the aims of the project.

Trial registration

ISCTRN 16267685 (09/03/2016).

     

Adrenal gland involvement in synchronizing the preovulatory release of LH in rats.

In this study we have demonstrated that acute adrenalectomy (1000 hr proestrus) has no effect on the release of LH on proestrous afternoon. However, chronic adrenalectomy results in the loss of some factor responsible for synchronizing the preovulatory LH surge. Since this investigator has shown previously (15) that progesterone can influence the timing of LH release in ovariectomized and ovariectomized-adrenalectomized animals, it is most likely that adrenal progesterone is involved in synchronizing this event.     

Revealing the factors that promote speciation

What biological attributes of organisms promote speciation, and ultimately, species diversity? This question has a long history of interest, with proposed diversity promoters including attributes such as sexual selection, ecological specialism and dispersability. However, such ideas are difficult to test because the time-scale of processes involved is too great for direct human observation and experimentation. An increasingly powerful solution is to investigate diversity patterns among extant groups to infer the nature of processes operating during the evolution of those groups. This approach relies on the use of robust, phylogenetically based null models to overcome some of the problems inherent in observational inference. We illustrate this area by (i) discussing recent advances in identifying correlates of diversity among higher taxa, and (ii) proposing new methods for analysing patterns in species-level phylogenies, drawing examples from a wide range of organisms.     

Increased abundance of a normal cell mRNA sequence accompanies the conversion of rat mammary cuboidal epithelial cells to elongated myoepithelial-like cells in culture.

Rat mammary cuboidal epithelial cell lines in culture convert to elongated myoepithelial-like cells. This conversion is accompanied by the appearance of a 9,000 molecular weight acidic polypeptide (p9ka), abundant in the elongated convertants, but which is hardly detectable in the cuboidal epithelial cells. A cDNA library corresponding to a low-molecular-weight fraction of poly(A)- containing RNA from a myoepithelial-like cell line, has been constructed. Recombinant plasmids containing cDNA complementary to p9ka mRNA have been identified by hybrid-selected translation. The mRNA for p9ka has been identified by Northern blotting and is found to be at least five-times more abundant in cultured myoepithelial-like rat mammary cells when compared to the cuboidal epithelial cells. This cytoplasmic mRNA sequence, which is present in increased abundance in cultured mammary myoepithelial-like cells, is also present, at lower levels, in normal rat tissues, including the mammary glands.     

Root growth,macro-nutrient uptake dynamics and soil fertility requirements of a high-yielding winter oilseed rape crop

Shoot growth, root growth and macro-nutrient uptake by a high-yielding (5t/ha grain) winter oilseed rape crop have been measured. Maximum rooting density in the top 20cm of soil was 9.4 cm cm⁻³ and roots reached a depth of at least 1.8 m. Maximum nutrient uptakes were 364 kg ha⁻¹ for N, 43 kg ha⁻¹ for P, 308 kg ha⁻¹ for K, 287 kg ha⁻¹ for Ca and 16 kg ha⁻¹ for Mg. A 30-day drought coincided with the flowering period and root and shoot growth, as well as nutrient uptake rates, were reduced. Nutrient concentrations in the soil solution necessary to sustain the nutrient fluxes into the root system by diffusive supply have been calculated. Peak values were in the range 10 μM for P to 87 μM for N, lower than the observed concentrations, and it was concluded that nutrient transport to roots was not a limitation to uptake by this rape crop.     

Invertebrate biodiversity in apple orchards: agrichemical sprays as explanatory variables for inter‐orchard community differences

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