Non-photoperiodic transition of female cannabis seedlings from juvenile to adult reproductive stage

Vegetative-to-reproductive phase transition in female cannabis seedlings occurs autonomously with the de novo development of single flowers. To ensure successful sexual reproduction, many plant species originating from seedlings undergo juvenile-to-adult transition. This phase transition precedes and enables the vegetative-to-reproductive shift in plants, upon perception of internal and/or external signals such as temperature, photoperiod, metabolite levels, and phytohormones. This study demonstrates that the juvenile seedlings of cannabis gradually shift to the adult vegetative stage, as confirmed by the formation of lobed leaves, and upregulation of the phase-transition genes. In the tested cultivar, the switch to the reproductive stage occurs with the development of a pair of single flowers in the 7th node. Histological analysis indicated that transition to the reproductive stage is accomplished by the de novo establishment of new flower meristems which are not present in a vegetative stage, or as dormant meristems at nodes 4 and 6. Moreover, there were dramatic changes in the transcriptomic profile of flowering-related genes among nodes 4, 6, and 7. Downregulation of flowering repressors and an intense increase in the transcription of phase transition-related genes occur in parallel with an increase in the transcription of flowering integrators and meristem identity genes. These results support and provide molecular evidence for previous findings that cannabis possesses an autonomous flowering mechanism and the transition to reproductive phase is controlled in this plant mainly by internal signals.

Comparative Assessment of Vegetative and Reproductive Terrestrial Plant Species Endpoints from Exposure to Herbicides and Potential Environmental Implications: A Review

To investigate whether vegetative endpoints are protective of reproductive endpoints in terrestrial plant risk assessments (RAs) for authorization of plant protection products (PPPs), we assessed differences in sensitivity to herbicides between these parameters. Published literature and unpublished proprietary data generated for the registration of PPPs were used to compile a database. If reproductive endpoints were systematically more sensitive than the vegetative endpoints on which regulatory decisions are presently based, a concern could be raised about the protectiveness of the current RA process. Vegetative and reproductive endpoints were assessed considering further potentially relevant parameters. Reproductive endpoints were compared with vegetative endpoints of juvenile plants or with those of mature plants. Direct comparison by substance-species combination proved to be most adequate and was used to calculate quotients by effect level. In addition, we assessed the spread between different effect levels, estimating by which factor the conservatism would increase if effect rate (ER)50 endpoints were replaced by ER25 or ER10 endpoints with otherwise unchanged test parameters. Reproductive endpoints were found to be similarly sensitive as vegetative endpoints derived in nontarget terrestrial plant (NTTP) studies conducted following Organisation for Economic Co-operation and Development (OECD) or US Office of Chemical Safety and Pollution Prevention (OCSPP) guidelines. A switch from vegetative to reproductive endpoints would therefore not significantly change the conservatism (less than a factor of 1.5), whereas the change from ER50 to ER10 would (by a factor of ~5 to 6). However, because ecotoxicological tests on terrestrial plants bear intrinsic high variability that prevents the reliable detection of effects at the 10% effect level, ER10 endpoints are not a reliable basis for RA. No particular family, genus, or species with clusters of distinctly insensitive vegetative and sensitive reproductive endpoints could be identified that would call for regular testing of reproductive endpoints. Also, from the data set available, no specific herbicidal modes of action could be singled out for acting particularly on reproductive endpoints. Integr Environ Assess Manag 2020;16:166-183. © 2019 SETAC.

Adolescent and adult differences in major depression symptom profiles

BACKGROUND

Depression is the leading global cause of disability and often begins in adolescence. The genetic architecture and treatment response profiles for adults and adolescents differ even though identical criteria are used to diagnose depression across different age groups. There is no clear consensus on how these groups differ in their symptom profiles.

METHODS

Using data from a two-generation family study, we compared the presentation of DSM-IV depressive symptoms in adolescents and adults with MDD (Major Depressive Disorder). We also compared DSM-IV depressive symptom counts using latent class analysis.

RESULTS

Vegetative symptoms (appetite and weight change, loss of energy and insomnia) were more common in adolescent MDD than adult MDD. Anhedonia/loss of interest and concentration problems were more common in adults with MDD. When using latent class analysis to look at depressive symptoms, a vegetative symptom profile was also seen in adolescent depression only.

LIMITATIONS

Adults and adolescents were recruited in different ways. Adolescent cases were more likely to be first-onset while adult cases were recurrences. It was not possible to examine how recurrence affected adolescent depression symptom profiles.

CONCLUSION

Differences in how depression presents in adolescents and adults may be consistent with different pathophysiological mechanisms. For adolescents, we found that vegetative/physical disturbances were common (loss of energy, changes in weight, appetite and sleep changes). For adults, anhedonia/loss of interest and concentration difficulties were more common.

Migration of Dictyostelium discoideum to the Chemoattractant Folic Acid

Dictyostelium discoideum can be grown axenically in a cultured media or in the presence of a natural food source, such as the bacterium Klebsiella aerogenes (KA). Here we describe the advantages and methods for growing D. discoideum on a bacterial lawn for several processes studied using this model system. When grown on a bacterial lawn, D. discoideum show positive chemotaxis towards folic acid (FA). While these vegetative cells are highly unpolarized, it has been shown that the signaling and cytoskeletal molecules regulating the directed migration of these cells are homologous to those seen in the motility of polarized cells in response to the chemoattractant cyclic adenosine monophosphate (cAMP). Growing D. discoideum on KA stimulates chemotactic responsiveness to FA. A major advantage of performing FA-mediated chemotaxis is that it does not require expression of the cAMP developmental program and therefore has the potential to identify mutants that are purely unresponsive to chemoattractant gradients. The cAMP-mediated chemotaxis can appear to fail when cells are developmentally delayed or do not up-regulate genes needed for cAMP-mediated migration. In addition to providing robust chemotaxis to FA, cells grown on bacterial lawns are highly resistant to light damage during fluorescence microscopy. This resistance to light damage could be exploited to better understand other biological processes such as phagocytosis or cytokinesis. The cell cycle is also shortened when cells are grown in the presence of KA, so the chances of seeing a mitotic event increases.

Aural Foreign Bodies Among Patients Presenting to Ibn Sina Teaching Hospital, Mukalla, Hadhramout Province, Yemen

Objective

To describe the types of aural foreign bodies (FBs) among patients in Ibn Sina Teaching Hospital (ISTH) and to study the patient's symptoms, duration, complications and procedures used to extract them.

Methods

A record based descriptive study was looked at patients with aural FBs at ISTH for 5 years between 2009 and 2015. The diagnosis of aural FBs was based on personal history, and otoscopic findings. The data were obtained from the records.

Results

Patients with aural FBs were 154, (age 1-70 years). Inorganic aural FBs were 100 (65%) and 54 (35%) were organic. Unilateral purulent aural discharge was in 72 (46.75%) patients, pain in 27 (17.53%), ear bleeding in 12 (7.8%), conductive hearing loss and tinnitus each was 8 (5.19%) and itching in 7 (4.55%). Duration of symptoms was <1 week in 55 (35.7%) cases, 1-2 weeks in 64 (41.6%) and 2-4 weeks in 29 (18.8%). Forceps, syringing, hook and suction were the tools used for removal of the FBs, 56 (36.4%), 40 (26.0%), 36 (23.4%), 14 (9.1%) respectively. FBs were removed under G.A. were 30 (19%). Complications were otitis externa in 38 (24.7%) cases, tympanic membrane perforation in 29 (18.85%) and external meatus laceration in 28 (18.20%).

Conclusion

The most common aural FBs found were inorganic (cotton tip, stone and eraser) and organic (fly, lice and bee). Complications were unilateral purulent discharge followed by pain and ear bleeding. FBs duration was from <1 to 4 weeks. The common procedures used were forceps, syringing, hook and suction. Particularly, organic vegetative FBs were removed under general anesthesia.

A diagnostic illusory? The case of distinguishing between "vegetative" and "minimally conscious" states

Throughout affluent societies there are growing numbers of people who survive severe brain injuries only to be left with long-term chronic disorders of consciousness. This patient group who exist betwixt and between life and death are variously diagnosed as in 'comatose', 'vegetative', and, more recently, 'minimally conscious' states. Drawing on a nascent body of sociological work in this field and developments in the sociology of diagnosis in concert with Bauman's thesis of 'ambivalence' and Turner's work on 'liminality', this article proposes a concept we label as diagnostic illusory in order to capture the ambiguities, nuanced complexities and tensions that the biomedical imperative to name and classify these patients give rise to. Our concept emerged through a reading of debates within medical journals alongside an analysis of qualitative data generated by way of a study of accounts of those close to patients: primarily relatives (N = 51); neurologists (N = 4); lawyers (N = 2); and others (N = 5) involved in their health care in the UK.