Sexual Experience Promotes Adult Neurogenesis in the Hippocampus Despite an Initial Elevation in Stress Hormones

Aversive stressful experiences are typically associated with increased anxiety and a predisposition to develop mood disorders. Negative stress also suppresses adult neurogenesis and restricts dendritic architecture in the hippocampus, a brain region associated with anxiety regulation. The effects of aversive stress on hippocampal structure and function have been linked to stress-induced elevations in glucocorticoids. Normalizing corticosterone levels prevents some of the deleterious consequences of stress, including increased anxiety and suppressed structural plasticity in the hippocampus. Here we examined whether a rewarding stressor, namely sexual experience, also adversely affects hippocampal structure and function in adult rats. Adult male rats were exposed to a sexually-receptive female once (acute) or once daily for 14 consecutive days (chronic) and levels of circulating glucocorticoids were measured. Separate cohorts of sexually experienced rats were injected with the thymidine analog bromodeoxyuridine in order to measure cell proliferation and neurogenesis in the hippocampus. In addition, brains were processed using Golgi impregnation to assess the effects of sexual experience on dendritic spines and dendritic complexity in the hippocampus. Finally, to evaluate whether sexual experience alters hippocampal function, rats were tested on two tests of anxiety-like behavior: novelty suppressed feeding and the elevated plus maze. We found that acute sexual experience increased circulating corticosterone levels and the number of new neurons in the hippocampus. Chronic sexual experience no longer produced an increase in corticosterone levels but continued to promote adult neurogenesis and stimulate the growth of dendritic spines and dendritic architecture. Chronic sexual experience also reduced anxiety-like behavior. These findings suggest that a rewarding experience not only buffers against the deleterious actions of early elevated glucocorticoids but actually promotes neuronal growth and reduces anxiety

Darwin’s muses behind his 1859 diagram

This article uses a review of a number of tree diagrams to highlight how the fact that Darwin was to choose the metaphor of a tree to describe evolutionary relationships between organisms should come as no great surprise, as the tree already occupied an important position in European iconography. In the review of some of the uses of a “tree” to represent different types of relationships in the pre-Darwinian age, we want to illustrate two basic issues. One particularly important issue is that Darwin had the insight of including various symbols and metaphors that were already being used to represent different aspects of the living world in his own theory of evolution, particularly the general metaphor of branching and rebranching. The other is that when Darwin published <i>On the Origin of Species</i> in 1859, people were already familiar with the idea of a tree to represent genealogy. This may have been an important factor in people’s familiarity with evolutionary diagrams and also in strongly associating them with religious metaphors.<br><br>En este artículo queremos mostrar mediante una revisión de algunos diagramas en forma de árbol, que el hecho de que Darwin escogiera la metáfora de un árbol para representar relaciones evolutivas entre los organismos no resulta enteramente sorpresivo, ya que la figura arbórea ya guardaba una posición importante en la tradición iconográfica europea. En la revisión de algunos usos del “árbol” para representar diferentes clases de relaciones en la época pre-darwiniana, queremos ilustrar dos cuestiones fundamentales. Una particularmente importante es que Darwin tuvo la brillantez de incorporar una variedad de símbolos y metáforas que ya estaban siendo usadas para representar diferentes aspectos del mundo vivo, en su propia teoría de la evolución, particularmente la metáfora general de la ramificación y re-ramificación. La otra es que cuando Darwin publicó <i>El Origen de las especies</i> en 1859, la gente ya estaba familiarizada con el tema del “árbol” para representar genealogías. Esto pudo haber sido importante para sentirse familiarizado con los diagramas evolutivos y para aceptarlos como entidades reales, también para asociarlos fuertemente con metáforas religiosas

Therapists’ perceptions and acceptability of providing internet-delivered guided self-help Acceptance and Commitment Therapy (ACT) for family carers of people with dementia (iACT4CARERS): a qualitative study

This study aimed to explore therapists' perceptions and acceptability of providing internet-delivered, therapist-guided, self-help acceptance and commitment therapy (ACT) for family carers of people with dementia (iACT4CARERS). To achieve this, a qualitative approach with semi-structured interviews was employed with eight novice therapists recruited from primary and secondary care services taking part in a feasibility study of iACT4CARERS. The interviews were audio-recorded, transcribed, and analysed using thematic analysis. Four over-arching themes were identified: (1) positive attitudes towards the intervention, (2) therapists' workload, (3) therapists' confidence to perform their role, and (4) connecting with family carers in a virtual context. Theme 1 included seeing their involvement as an opportunity for personal growth and perceiving benefits to the family carers, which contributed to greater acceptability. Theme 2 reflected that while workload and the user-friendliness of the online platform were highly acceptable among the therapists, there were also time-consuming cases that increased therapists' burden. Theme 3 revealed that practical resources provided during the training, continued supervision, and opportunities to learn from other therapists, increased therapist confidence and facilitated greater acceptability. Finally, Theme 4 highlighted that improving the connection between therapists and carers was critical in a virtual context and strategies to improve the therapist-carer relationship were recommended. The implementation of iACT4CARERS was largely acceptable for the therapists involved in the trial. Ways to strengthen the therapeutic relationship in the virtual context and practical strategies to deal with common problems may enhance therapist experience and delivery in a full-scale effectiveness trial. Key learning aims (1) To understand which factors facilitated therapists' positive perceptions and acceptability of providing internet-delivered guided self-help ACT (iACT4CARERS). (2) To understand what challenges acted as barriers to therapists' positive perceptions and acceptability of providing iACT4CARERS. (3) To learn what aspects of the training and the intervention can be refined to improve the acceptability to therapists in trials involving internet-delivered guided self-help interventions for family carers

Novel virus discovery and genome reconstruction from field RNA samples reveals highly divergent viruses in dipteran hosts.

We investigated whether small RNA (sRNA) sequenced from field-collected mosquitoes and chironomids (Diptera) can be used as a proxy signature of viral prevalence within a range of species and viral groups, using sRNAs sequenced from wild-caught specimens, to inform total RNA deep sequencing of samples of particular interest. Using this strategy, we sequenced from adult Anopheles maculipennis s.l. mosquitoes the apparently nearly complete genome of one previously undescribed virus related to chronic bee paralysis virus, and, from a pool of Ochlerotatus caspius and Oc. detritus mosquitoes, a nearly complete entomobirnavirus genome. We also reconstructed long sequences (1503-6557 nt) related to at least nine other viruses. Crucially, several of the sequences detected were reconstructed from host organisms highly divergent from those in which related viruses have been previously isolated or discovered. It is clear that viral transmission and maintenance cycles in nature are likely to be significantly more complex and taxonomically diverse than previously expected

Internet-delivered guided self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): A qualitative study of carer views and acceptability

Purpose: To explore carers’ views and acceptability of internet-delivered, therapist-guided, self-help Acceptance and Commitment Therapy (ACT) for family carers of people with dementia (iACT4CARERS).  Methods: A qualitative approach with semi-structured interviews was employed with family carers (N=23) taking part in a feasibility study of iACT4CARERS. The interviews were audio- recorded, transcribed and analysed using thematic analysis.  Results: Four overarching themes were identified: 1) usefulness and relevance of the content of the sessions, 2) sense of connectedness, 3) the impact of the intervention on participants and 4) acceptability of the online delivery. Positive carer experiences and intervention acceptability were facilitated by learning helpful ACT skills, perceiving the content of the session as relatable to the carers' needs, feeling connected to other carers and the therapist during the intervention, noticing the benefits of the intervention and the user-friendliness of the online platform. Recommendations for a full-scale trial were identified, such as the inclusion of some ‘face-to-face’ interactions (e.g. via video call) between carers and therapists to facilitate a bidirectional interaction and the provision of an additional aide-memoire to improve the learning experiences.  Conclusion: Overall, the intervention was acceptable to the family carers. The proposed recommendations should be considered in a full-scale trial

Carers’ and therapists’ views of internet-delivered guided self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): A qualitative study in the context of ethnic minority families

This study aimed to explore the views of family carers of people living with dementia from ethnic minority groups and their therapists on internet-delivered, self-help acceptance and commitment therapy for family carers (iACT4CARERS), enhanced with additional therapist guidance. To achieve this, a qualitative approach with semi-structured interviews was employed with ethnic minority carers who completed Enhanced iACT4CARERS (n=9) and therapists who supported them throughout the programme (n=5). The interviews were audio-recorded, transcribed and analysed using framework analysis. Four over-arching themes were identified: (1) Value of the programme to ethnic minority carers, (2) Barriers for ethnic minority carers, (3) Sense of connectedness through written feedback, and (4) Sense of connectedness through one-to-one sessions. Theme 1 reflected that ethnic minority carers valued ACT techniques, highlighting their usefulness and simplicity, leading to perceived benefits. Theme 2 revealed the irrelevance of examples provided of carer experiences throughout the programme due to differences in family carers' experiences of providing care within ethnic minority communities. Theme 3 highlighted that carers' engagement with the programme was facilitated by feelings of validation and encouragement received from their therapist via weekly written feedback. Finally, Theme 4 highlighted that additional one-to-one support sessions allowed both carers and therapists to develop strong therapeutic relationships. This enhanced subsequent text-based online interactions, allowing carers to be more open and engaged. Also, therapists reported that a strong sense of connectedness helped them to tailor their feedback. Enhanced iACT4CARERS that uses carers' experiences more relevant to ethnic minority communities may be more acceptable. Key learning aims (1) To understand the views of family carers of people living with dementia from ethnic minority groups and their therapists on internet-delivered, self-help acceptance and commitment therapy (ACT), which has been found to be feasible and acceptable with White British carers. (2) To understand whether additional one-to-one support can help develop effective therapeutic relationships and thus improve the experiences of carers in completing the programme. (3) To learn whether any cultural adaptations are needed to improve the acceptability of internet-delivered self-help ACT among this population

Internet-delivered guided self-help Acceptance and Commitment Therapy for family carers of people with dementia (iACT4CARERS): A feasibility study

Objective: The feasibility of research into internet-delivered guided self-help Acceptance and Commitment Therapy (ACT) for family carers of people with dementia is not known. This study assessed this in an uncontrolled feasibility study. Methods: Family carers of people with dementia with mild to moderate anxiety or depression were recruited from primary and secondary healthcare services in the UK. Participants were offered eight, guided, self-help online ACT sessions adapted for the needs of family carers of people with dementia with optional online peer support groups. Pre-defined primary indicators of success included recruitment of 30 eligible carers over six months and ≥70% completing at least two online sessions. Results: Thirty-three participants (110% of the target sample) were recruited over six months and 30 participants (91%) completed two or more sessions, and thus both indicators of success were met. Further, 70% of participants completed seven or all eight sessions, and 27% of participants were lost to follow-up, but none of the reasons for early withdrawal were related to the intervention. Conclusion: This study supports the feasibility, including recruitment and treatment completion. A full-scale trial to assess the clinical- and cost-effectiveness of the intervention including its long-term effects is warranted. Registration: ISRCTN trial registration 1895641

Transmission pathways for sporadic Shiga-toxin producing E. coli infections: A systematic review and meta-analysis

Background: Shiga-toxin E. coli infections remain a public health concern because of the severity of the gastrointestinal illness and associated complications. Transmission pathways are typically elucidated from outbreaks, with foodborne transmission the primary source. However, most STEC cases are sporadic. This systematic review aimed to identify the most common pathways for sporadic STEC transmission and quantify their importance. Methods: We systematically reviewed epidemiological studies of sporadic (non-outbreak) STEC cases that investigated potential risk factors. Searches were run in Medline, EMBASE, and Scopus. Included studies needed to confirm STEC infection and investigate ≥20 cases. Results: 31 studies were included, of which 25 were case-control or case-case studies. 62.5% found consumption of undercooked/raw meat associated with STEC infection while 70.4% found contact with animals or their environment a risk factor. Random-effects meta-analysis provided pooled odds ratios and population attributable fraction (PAF). The PAF was 19% for undercooked/raw meat, followed by person to person transmission at 15%. Contact with animals and visiting farm environments had PAFs of 14% and 12% respectively. Conclusions: Out of potential sources for STEC exposure, undercooked meat and contact with animals and their environment were the most frequently found transmission routes. Decreasing the chances of acquiring the bacteria by these methods would additionally cut down on the other major transmission route, person-to-person spread

Broadly sampled multigene analyses yield a well-resolved eukaryotic tree of life

Author Posting. © The Authors, 2010. This is the author's version of the work. It is posted here by permission of Oxford University Press for personal use, not for redistribution. The definitive version was published in Systematic Biology 59 (2010): 518-533, doi:10.1093/sysbio/syq037.An accurate reconstruction of the eukaryotic tree of life is essential to identify the innovations underlying the diversity of microbial and macroscopic (e.g. plants and animals) eukaryotes. Previous work has divided eukaryotic diversity into a small number of high-level ‘supergroups’, many of which receive strong support in phylogenomic analyses. However, the abundance of data in phylogenomic analyses can lead to highly supported but incorrect relationships due to systematic phylogenetic error. Further, the paucity of major eukaryotic lineages (19 or fewer) included in these genomic studies may exaggerate systematic error and reduces power to evaluate hypotheses. Here, we use a taxon-rich strategy to assess eukaryotic relationships. We show that analyses emphasizing broad taxonomic sampling (up to 451 taxa representing 72 major lineages) combined with a moderate number of genes yield a well-resolved eukaryotic tree of life. The consistency across analyses with varying numbers of taxa (88-451) and levels of missing data (17-69%) supports the accuracy of the resulting topologies. The resulting stable topology emerges without the removal of rapidly evolving genes or taxa, a practice common to phylogenomic analyses. Several major groups are stable and strongly supported in these analyses (e.g. SAR, Rhizaria, Excavata), while the proposed supergroup ‘Chromalveolata’ is rejected. Further, extensive instability among photosynthetic lineages suggests the presence of systematic biases including endosymbiotic gene transfer from symbiont (nucleus or plastid) to host. Our analyses demonstrate that stable topologies of ancient evolutionary relationships can be achieved with broad taxonomic sampling and a moderate number of genes. Finally, taxonrich analyses such as presented here provide a method for testing the accuracy of relationships that receive high bootstrap support in phylogenomic analyses and enable placement of the multitude of lineages that lack genome scale data