RESUMEN
Hosting 1460 plant and 126 vertebrate endemic species, the Great Escarpment (hereafter, Escarpment) forms a semi-circular "amphitheater" of mountains girdling southern Africa from arid west to temperate east. Since arid and temperate biota are usually studied separately, earlier studies overlooked the biogeographical importance of the Escarpment as a whole. Bats disperse more widely than other mammalian taxa, with related species and intraspecific lineages occupying both arid and temperate highlands of the Escarpment, providing an excellent model to address this knowledge gap. We investigated patterns of speciation and micro-endemism from modeled past, present, and future distributions in six clades of southern African bats from three families (Rhinolophidae, Cistugidae, and Vespertilionidae) having different crown ages (Pleistocene to Miocene) and biome affiliations (temperate to arid). We estimated mtDNA relaxed clock dates of key divergence events across the six clades in relation both to biogeographical features and patterns of phenotypic variation in crania, bacula and echolocation calls. In horseshoe bats (Rhinolophidae), both the western and eastern "arms" of the Escarpment have facilitated dispersals from the Afrotropics into southern Africa. Pleistocene and pre-Pleistocene "species pumps" and temperate refugia explained observed patterns of speciation, intraspecific divergence and, in two cases, mtDNA introgression. The Maloti-Drakensberg is a center of micro-endemism for bats, housing three newly described or undescribed species. Vicariance across biogeographic barriers gave rise to 29 micro-endemic species and intraspecific lineages whose distributions were congruent with those identified in other phytogeographic and zoogeographic studies. Although Köppen-Geiger climate models predict a widespread replacement of current temperate ecosystems in southern Africa by tropical or arid ecosystems by 2070-2100, future climate Maxent models for 13 bat species (all but one of those analyzed above) showed minimal range changes in temperate species from the eastern Escarpment by 2070, possibly due to the buffering effect of mountains to climate change.
Asunto(s)
Quirópteros , Cambio Climático , ADN Mitocondrial , Animales , Quirópteros/fisiología , Quirópteros/genética , África Austral , ADN Mitocondrial/genética , ADN Mitocondrial/análisis , Filogenia , Especiación Genética , Filogeografía , Distribución AnimalRESUMEN
The African continent was subjected to periodic climatic shifts during the Pliocene and Pleistocene. These habitat changes greatly affected the evolutionary processes and tempo of diversification in numerous, widely distributed mammals. The Otomyini (Family Muridae) comprises three African rodent genera, Parotomys, Otomys and Myotomys, characterized by unique laminated-shaped molars. Species within this tribe generally prefer open-habitat and show low dispersal capabilities, with previous studies suggesting that their diversification was closely associated with climatic oscillations over the last four million years. Our phylogenetic reconstructions, based on three mitochondrial (mtDNA) genes (Cytb, COI and 12S) and four nuclear introns (EF, SPTBN, MGF and THY), identified eight major genetic clades that are distributed across southern, eastern and western Africa. Our data permit the re-examination of the taxonomic status of the three genera as well as the previously proposed mesic-arid dichotomy of the 10 South African species. Moreover, multiple mtDNA species delimitation methods incorporating 168 specimens estimated the number of Otomyini species to be substantially higher than the â¼ 30 recognized, suggesting that the current taxonomy will necessitate an integrative approach to delimit extant species diversity within the Otomyini. The data suggests that the origin of the tribe can be dated back to â¼ 5.7 million years ago (Ma) in southern Africa. The distribution and phylogenetic associations among the eight major otomyine evolutionary lineages can best be explained by several waves of northward colonization from southern Africa, complemented by independent reversed dispersals from eastern back to southern Africa at different time periods. There is strong support for the hypothesis that the radiation, dispersion, and diversification of the otomyine rodents is closely linked to recent Plio-Pleistocene climatic oscillations.
Asunto(s)
Evolución Biológica , Ecosistema , Ratas , Animales , Filogenia , Murinae/genética , ADN Mitocondrial/genéticaRESUMEN
BACKGROUND: Self-harm is a major public health concern. Lifetime prevalence is high, and rates of self-harm are rising; however, available interventions do not benefit everyone, and engagement with therapy can be low. Qualitative accounts allow for a greater understanding of what is helpful to individuals. This study aimed to synthesize the experiences of interventions for self-harm, from participants who have participated in these themselves. METHODS: Participants had self-harmed at least once and undergone an individual psychotherapeutic intervention for self-harm. Papers not written or translated to the English language were excluded. Four databases (Medline, CINAHL, Web of Science and PsycINFO) were systematically searched and each paper was assessed using the CASP quality appraisal tool. A meta-ethnographic approach to the synthesis was taken. RESULTS: Ten studies encompassing 104 participants were included. Four overarching themes were developed and the importance of recognizing the person beyond the self-harm emerged through a line of argument synthesis. Building a trusted, therapeutic relationship founded on patience and without judgement was essential for the perceived success of therapy, which was unique to each person and often went beyond reducing self-harming behaviours. LIMITATIONS: Papers included in the study showed a lack of diversity with regard to ethnicity and gender. CONCLUSIONS: The findings illustrate the importance of the therapeutic alliance when working with self-harm. Clinical implications of this paper include the importance of utilizing key therapeutic competencies which should be considered fundamental to change within psychotherapeutic interventions for self-harm, with the uniqueness of each patient recognized throughout.
Asunto(s)
Conducta Autodestructiva , Humanos , Conducta Autodestructiva/terapia , Antropología Cultural , PsicoterapiaRESUMEN
BACKGROUND: Rumination is a cognitive process that has been implicated in the onset and maintenance of a variety of psychological difficulties. The purpose of this review and meta-analysis was to examine the nature and strength of the relationship between rumination and non-suicidal self-injury (NSSI). METHODS: The protocol for this review was pre-registered (CRD42019148186). A literature search of electronic databases PsycINFO, CINAHL, MEDLINE, and Web of Science was performed from the earliest date available to March 2020. Thirty-nine eligible papers were identified. An additional seven papers were identified from a search conducted in September 2021, resulting in a total of 46 papers. Separate meta-analyses were undertaken for NSSI frequency and NSSI history, with studies grouped by rumination type (depressive, transdiagnostic, anger, brooding, reflection, catastrophising, overall). Moderator analyses were also conducted along with a narrative synthesis of adjusted associations and longitudinal studies. RESULTS: Rumination had a positive small association with NSSI frequency and a positive moderate association with NSSI history. The adjusted associations yielded mixed findings and most longitudinal research found rumination to be associated with prospective NSSI. LIMITATIONS: Most included studies had a moderate risk of bias and used a student sample. A limitation of this review was that only English language papers were included. CONCLUSIONS: Findings indicate that rumination is associated with NSSI, but more so the likelihood of engaging in NSSI overall than the frequency. Rumination-focused techniques for NSSI may therefore be of benefit. Further research is needed to understand this association, particularly with longitudinal studies that focus on state rumination rather than stable trait rumination. PRACTITIONER POINTS: Rumination was found to have a small to moderate association with NSSI. Some individuals who engage in NSSI may benefit from psychological techniques that target rumination. Most of the studies included had a moderate risk of bias.
Asunto(s)
Conducta Autodestructiva , Humanos , Estudios Prospectivos , Conducta Autodestructiva/psicología , EstudiantesRESUMEN
OBJECTIVES: Suicide is a major public health concern and is now considered to be the leading cause of death in young people. Suicidal ideation within student populations has recently increased. The Broad-Minded Affective Coping (BMAC) offers a brief psychological intervention targeting suicidal ideation by enabling access to competing positive emotions and thoughts using guided imagery. Its acceptability and feasibility in student populations are unclear. DESIGN: A single arm pilot study investigated the feasibility and acceptability of a six-session BMAC intervention for university students experiencing suicidal ideation. METHOD: Recruitment took place from university counselling services. Suicidal ideation and emotional states were assessed at baseline and after 6 and 12 weeks. Participants also completed corresponding sessional measures. RESULTS: Twelve eligible participants consented to take part with 11 receiving the intervention. Ten participants completed post treatment and follow up assessments. Retention to treatment was high with participants attending an average of 5.2 (87%; SD = 1.54) out of six intervention sessions. There were also good completion rates of the BMAC technique between sessions. Participants reported high levels of satisfaction with the intervention. There was an associated reduction across a range of clinical outcomes, including suicidal ideation, with large effect sizes. DISCUSSION: This pilot study showed promising results on the feasibility and acceptability of the BMAC intervention in students experiencing suicidal ideation. However, the study had a small sample size and no comparator control group. Further exploration of the BMAC intervention is warranted.
Asunto(s)
Imágenes en Psicoterapia , Ideación Suicida , Adolescente , Humanos , Proyectos Piloto , Estudiantes/psicología , UniversidadesRESUMEN
Hearing capabilities in desert rodents such as gerbils and heteromyids have been inferred from both anatomical and ecological aspects and tested with experiments and theoretical models. However, very few studies have focused on other desert-adapted species. In this study, a refined three-dimensional morphometric approach was used on three African rodent tribes (Otomyini, Taterillini and Gerbillini) to describe the cochlear and tympanic bullar morphology, and to explore the role of phylogeny, allometry and ecology to better understand the underlying mechanism of any observed trends of hypertrophy in the bulla and associated changes in the cochlea. As a result, desert-adapted species could be distinguished from mesic and semi-arid taxa by the gross cochlear dimensions, particularly the oval window, which is larger in desert species. Bullar and cochlear modifications between species could be explained by environment (bulla and oval window), phylogeny (cochlear curvature gradient) and/or allometry (cochlear relative length, oval window and bulla) with some exceptions. Based on their ear anatomy, we predict that Desmodillus auricularis and Parotomys brantsii should be sensitive to low-frequency sounds, with D. auricularis sensitive to high-frequency sounds, too. This study concludes that in both arid and semi-arid adapted laminate-toothed rats and gerbils there is bulla and associated cochlea hypertrophy, particularly in true desert species. Gerbils also show tightly coiled cochlea but the significance of this is debatable and may have nothing to do with adaptations to any specific acoustics in the desert environment.
Asunto(s)
Adaptación Biológica , Cóclea/anatomía & histología , Gerbillinae/anatomía & histología , Murinae/anatomía & histología , Cráneo/anatomía & histología , África , Animales , Evolución Biológica , Clima Desértico , Ecosistema , Femenino , MasculinoRESUMEN
Pteropodidae and Hipposideridae are 2 of the 9 chiropteran families that occur on Madagascar. Despite major advancements in the systematic study of the island's bat fauna, few karyotypic data exist for endemic species. We utilized G- and C-banding in combination with chromosome painting with Myotismyotis probes to establish a genome-wide homology among Malagasy species belonging to the families Pteropodidae (Pteropus rufus 2n = 38; Rousettus madagascariensis, 2n = 36), Hipposideridae (Hipposideros commersoni s.s., 2n = 52), and a single South African representative of the Rhinolophidae (Rhinolophus clivosus, 2n = 58). Painting probes of M. myotis detected 26, 28, 28, and 29 regions of homology in R. madagascariensis, P. rufus, H. commersoni s.s, and R. clivosus, respectively. Translocations, pericentric inversions, and heterochromatin additions were responsible for karyotypic differences amongst the Malagasy pteropodids. Comparative chromosome painting revealed a novel pericentric inversion on P. rufus chromosome 4. Chromosomal characters suggest a close evolutionary relationship between Rousettus and Pteropus. H. commersoni s.s. shared several chromosomal characters with extralimital congeners but did not exhibit 2 chromosomal synapomorphies proposed for Hipposideridae. This study provides further insight into the ancestral karyotypes of pteropodid and hipposiderid bats and corroborates certain molecular phylogenetic hypotheses.
Asunto(s)
Quirópteros/clasificación , Quirópteros/genética , Pintura Cromosómica , Evolución Molecular , Cariotipo , Animales , Bandeo Cromosómico , Inversión Cromosómica , Cromosomas de los Mamíferos/genética , Heterocromatina , Madagascar , Filogenia , Translocación GenéticaRESUMEN
BACKGROUND: Immediate-release (IR) quetiapine has been used to treat schizophrenia since 1997, although all the principal placebo-controlled trials have >50% missing outcome data. New studies with relatively lower rates of participant withdrawal have since been published. AIMS: To assess the efficacy and adverse effects of quetiapine IR for schizophrenia, with consideration of outcome quality and clinical meaningfulness of results, and to examine the potential impact of missing data on the main efficacy findings. METHOD: We conducted a systematic review and meta-analysis of randomised controlled trials comparing quetiapine IR and placebo (or subtherapeutic dose in relapse prevention trials) for the treatment of schizophrenia (PROSPERO registration CRD4201100165). Primary outcomes were change in overall symptoms and response rates. We also examined whether high rates of participant withdrawal (≥50%) attenuated effect sizes, and assessed the impact of making different assumptions about these people's outcomes. RESULTS: We identified 15 relevant trials (including 2 unpublished), providing the first 12-week data for this drug and the first data on self-reported quality of life. We found quetiapine IR to have a weighted mean difference (WMD) of 6.5 points (95% CI -8.9 to -4) on Positive and Negative Syndrome Scale (PANSS) total scores, which corresponds to a standardised mean difference (SMD) of -0.33 (95% CI -0.46 to -0.21). Longer trials reported larger mean differences favouring quetiapine IR, but the overall estimate was smaller if more conservative assumptions about the outcomes of people who left the trial early were made. Approximately 21 people needed to take quetiapine IR for 1 person to experience at least a 50% improvement in PANSS score. No difference in quality of life was observed (two RCTs), although small to moderate improvements in social functioning were found (three RCTs). Quetiapine IR caused sedation and increased rates of clinically significant weight gain, but no extrapyramidal effects were observed. CONCLUSIONS: Quetiapine IR has a small beneficial effect on overall psychotic symptoms over 2-12 weeks, but also leads to weight gain and sedation.
Asunto(s)
Antipsicóticos/administración & dosificación , Fumarato de Quetiapina/administración & dosificación , Esquizofrenia/tratamiento farmacológico , Antipsicóticos/efectos adversos , Humanos , Calidad de Vida , Fumarato de Quetiapina/efectos adversos , Ensayos Clínicos Controlados Aleatorios como Asunto , Autoinforme , Resultado del Tratamiento , Aumento de PesoRESUMEN
OBJECTIVES: Negative beliefs about psychosis and other mental health difficulties may contribute to depression and distress in individuals with these experiences. The Personal Beliefs about Experience Questionnaire (PBEQ) and Personal Beliefs about Illness Questionnaire (PBIllQ) are two widely used measures of these beliefs. It is currently uncertain how the items on these measures map onto different underlying factors. This study therefore aimed to test the factor structure of these two measures. METHODS: Confirmatory factor analysis (CFA) was used to test three alternative, pre-specified, factor structures for the PBIllQ and PBEQ in a sample of individuals diagnosed with bipolar disorder (n = 202) and a sample of individuals with experien-ces of psychosis (n = 362). Associations with depressive symptoms were also examined. RESULT: A three-factor structure was supported for both measures, which included Negative Expectations/Appraisals (NEA), Internal Shame/Defectiveness (ISD) and External Shame (ES) factors. The NEA and ISD subscales also had consistent independent associations with depressive symptoms. CONCLUSIONS: The results suggest that the PBIllQ and PBEQ may capture three distinct sets of negative beliefs in individuals with psychosis or bipolar disorder and that these beliefs may have important consequences for subsequent difficulties in these populations such as depression. Both measures may be helpful in supporting assessment and formulation in clinical practice and in evaluating belief change in intervention trials. However, when used in these settings, the three subscales identified in this study may be the most valid way of calculating scores on these measures. PRACTITIONER POINTS: Negative personal beliefs about the causes, meaning and consequences of psychosis and bipolar disorder are associated with greater distress and depression. Two related measures, the PBIllQ and PBEQ, have been developed to assess these beliefs. Our analyses suggest that scores on these questionnaires are best broken down into three subscales which capture perceptions of internal shame or defectiveness, general negative appraisals and perceptions of external shame. These subscales may capture key underlying sets of negative beliefs within individuals with psychosis or bipolar disorder, which in turn impact upon well-being, such as being associated with greater depression. These subscales can be used to aid assessment and formulation within clinical practice but may also provide a valuable means of assessing changes in negative beliefs following interventions.
Asunto(s)
Actitud Frente a la Salud , Trastorno Bipolar/diagnóstico , Psicometría/instrumentación , Trastornos Psicóticos/diagnóstico , Encuestas y Cuestionarios , Adulto , Trastorno Bipolar/psicología , Depresión , Análisis Factorial , Femenino , Humanos , Masculino , Salud Mental , Persona de Mediana Edad , Psicometría/estadística & datos numéricos , Trastornos Psicóticos/psicología , Reproducibilidad de los Resultados , VergüenzaRESUMEN
We describe mutations in the PML nuclear body protein Sp110 in the syndrome veno-occlusive disease with immunodeficiency, an autosomal recessive disorder of severe hypogammaglobulinemia, combined T and B cell immunodeficiency, absent lymph node germinal centers, absent tissue plasma cells and hepatic veno-occlusive disease. This is the first report of the involvement of a nuclear body protein in a human primary immunodeficiency and of high-penetrance genetic mutations in hepatic veno-occlusive disease.
Asunto(s)
Enfermedad Veno-Oclusiva Hepática/genética , Síndromes de Inmunodeficiencia/genética , Mutación , Proteínas Nucleares/genética , Femenino , Humanos , Masculino , Antígenos de Histocompatibilidad Menor , LinajeRESUMEN
Chromosomal microarray (CMA) is the first-line diagnostic test for individuals with intellectual disability, autism, or multiple congenital anomalies, with a 10-20% diagnostic yield. An ongoing challenge for the clinician and laboratory scientist is the interpretation of variants of uncertain significance (VOUS)-usually rare, unreported genetic variants. Laboratories differ in their threshold for reporting VOUS, and clinical practice varies in how this information is conveyed to the family and what follow-up is arranged. Workflows, websites, and databases are constantly being updated to aid the interpretation of VOUS. There is a growing literature reporting new microdeletion and duplication syndromes, susceptibility, and modifier copy number variants (CNVs). Diagnostic methods are also evolving with new array platforms and genome builds. In 2010, high-resolution arrays (Affymetrix 2.7 M Oligo and SNP, 50 kB resolution) were performed on a community cohort of 67 individuals with intellectual disability of unknown aetiology. Three hundred and one CNVs were detected and analyzed using contemporary resources and a simple scoring system. Thirteen (19%) of the arrays were assessed as potentially pathogenic, 4 (6%) as benign and 50 (75%) of uncertain clinical significance. The CNV data were re-analyzed in 2012 using the contemporary interpretative resources. There was a statistically significant difference in the assessment of individual CNVs (P < 0.0001). An additional eight patients were reassessed as having a potentially pathogenic array (n = 21, 31%) and several additional susceptibility or modifier CNVs were identified. This study highlights the complexity involved in the interpretation of CMA and uniquely demonstrates how, even on the same array platform, it can be subject to change over time.
Asunto(s)
Aberraciones Cromosómicas , Discapacidad Intelectual/genética , Estudios de Cohortes , Variaciones en el Número de Copia de ADN , Femenino , Humanos , Discapacidad Intelectual/diagnóstico , Masculino , Análisis de Secuencia por Matrices de Oligonucleótidos , Polimorfismo de Nucleótido SimpleRESUMEN
Morphometric studies of 3D micro CT-scanned images can provide insights into the evolution of the brain and sensory structures but such data are still scarce for the most diverse mammalian order of rodents. From reviewed and new data, we tested for convergence to extreme aridity and high elevation in the sensory and brain morphology of rodents, from morphometric data from micro-CT X-ray scans of 174 crania of 16 species of three distantly related African murid (soft-furred mice, Praomyini, laminate-toothed rats, Otomyini, and gerbils, Gerbillinae) clades and one North American cricetid (deer mice and white-footed mice, Peromyscus) clade. Recent studies demonstrated convergent evolution acting on the oval window area of the cochlea (enlarged in extremely arid-adapted species of Otomyini and Gerbillinae) and on endocranial volume (reduced in high elevation taxa of Otomyini and Peromyscus). However, contrary to our predictions, we did not find evidence of convergence in brain structure to aridity, or in the olfactory/respiratory system (turbinate bones) to high elevation. Brain structure differed, particularly in the petrosal lobules of the cerebellum and the olfactory bulbs, between Otomyini and Gerbillinae, with extreme arid-adapted species in each clade being highly divergent (not convergent) from other species in the same clade. We observed greater "packing" of the maxillary turbinate bones, which have important respiratory functions, in Peromyscus mice from high and low elevations compared to the high-elevation African Praomyini, but more complex patterns within Peromyscus, probably related to trade-offs in respiratory physiology and heat exchange in the nasal epithelium associated with high-elevation adaptation.
Asunto(s)
Muridae , Peromyscus , Ratas , Animales , Gerbillinae , Encéfalo , América del NorteRESUMEN
Recent biological surveys of ancient inselbergs in southern Malawi and northern Mozambique have led to the discovery and description of many species new to science, and overlapping centres of endemism across multiple taxa. Combining these endemic taxa with data on geology and climate, we propose the 'South East Africa Montane Archipelago' (SEAMA) as a distinct ecoregion of global biological importance. The ecoregion encompasses 30 granitic inselbergs reaching > 1000 m above sea level, hosting the largest (Mt Mabu) and smallest (Mt Lico) mid-elevation rainforests in southern Africa, as well as biologically unique montane grasslands. Endemic taxa include 127 plants, 45 vertebrates (amphibians, reptiles, birds, mammals) and 45 invertebrate species (butterflies, freshwater crabs), and two endemic genera of plants and reptiles. Existing dated phylogenies of endemic animal lineages suggests this endemism arose from divergence events coinciding with repeated isolation of these mountains from the pan-African forests, together with the mountains' great age and relative climatic stability. Since 2000, the SEAMA has lost 18% of its primary humid forest cover (up to 43% in some sites)-one of the highest deforestation rates in Africa. Urgently rectifying this situation, while addressing the resource needs of local communities, is a global priority for biodiversity conservation.
Asunto(s)
Mariposas Diurnas , Animales , Biodiversidad , África Oriental , Reptiles , Bosques , Sudáfrica , Filogenia , MamíferosRESUMEN
OBJECTIVES: Parental appraisals of an adolescent may have an effect upon the adolescent's well-being and likelihood of emotional problems. However, the impact of these parental appraisals is likely to be partly determined by the young person's self-appraisal. It was predicted that a discrepancy in self- and parent appraisals of positive, prosocial qualities would be associated with an increased risk of emotional problems. DESIGN: The study employed a cross-sectional design within a large sample of adolescent and caregiver dyads (N = 3,976, aged 11-17 years), drawn from the 'Mental health of children and young people in Great Britain, 2004' survey. METHOD: Two separate measures of prosociality were used to ensure that effects were not specific to one measure. The analysis explored the discrepancy in parent and self-ratings on these measures via interactions within a logistic regression framework. Potential confounds, including gender, parental mental health, conduct and hyperkinetic problems were controlled for in the analysis. RESULTS: The logistic regression analyses demonstrated significant interactions between self- and parent ratings of prosocial qualities in predicting the odds of emotional disorder (i.e., depression and anxiety). This effect occurred across both measures of prosocial qualities whilst controlling for confounds. The pattern of the interactions suggested that low parental appraisals had a more detrimental effect on well-being when self-appraisals were highly positive. CONCLUSIONS: The results suggest that moderately high self-appraised positive traits may carry a cost of leaving young people more vulnerable to discrepant, negative parental appraisals. This has important implications for the meaning attributed to self-appraised positive traits in clinical contexts. PRACTITIONER POINTS: Clinicians should be aware that the association between parental perceptions of a child's prosociality and emotional disorder may be influenced by the adolescents' self-perceptions. Clinicians should therefore endeavour to assess both parental and adolescent appraisals. Discrepancies may be clinically meaningful, in terms of the risk of emotional problems, rather than simply being a nuisance. This study is cross-sectional, so although discrepancies may be linked to risk of emotional problems, the direction of this effect requires elucidation. The current study only focusses on the parent-adolescent dynamic and so may not extend to discrepancy effects in other areas of positive functioning or in other relational contexts.
Asunto(s)
Trastornos de Ansiedad/diagnóstico , Trastorno Depresivo/diagnóstico , Autoevaluación Diagnóstica , Padres/psicología , Conducta Social , Adolescente , Conducta del Adolescente/psicología , Trastornos de Ansiedad/psicología , Niño , Estudios Transversales , Trastorno Depresivo/psicología , Femenino , Humanos , Masculino , Autoimagen , Distribución por Sexo , Reino UnidoRESUMEN
To better understand functional morphological adaptations to high elevation (> 3000 m above sea level) life in both North American and African mountain-associated rodents, we used microCT scanning to acquire 3D images and a 3D morphometric approach to calculate endocranial volumes and skull lengths. This was done on 113 crania of low-elevation and high-elevation populations in species of North American cricetid mice (two Peromyscus species, n = 53), and African murid rodents of two tribes, Otomyini (five species, n = 49) and Praomyini (four species, n = 11). We tested two distinct hypotheses for how endocranial volume might vary in high-elevation populations: the expensive tissue hypothesis, which predicts that brain and endocranial volumes will be reduced to lessen the costs of growing and maintaining a large brain; and the brain-swelling hypothesis, which predicts that endocranial volumes will be increased either as a direct phenotypic effect or as an adaptation to accommodate brain swelling and thus minimize pathological symptoms of altitude sickness. After correcting for general allometric variation in cranial size, we found that in both North American Peromyscus mice and African laminate-toothed (Otomys) rats, highland rodents had smaller endocranial volumes than lower-elevation rodents, consistent with the expensive tissue hypothesis. In the former group, Peromyscus mice, crania were obtained not just from wild-caught mice from high and low elevations but also from those bred in common-garden laboratory conditions from parents caught from either high or low elevations. Our results in these mice showed that brain size responses to elevation might have a strong genetic basis, which counters an opposite but weaker environmental effect on brain volume. These results potentially suggest that selection may act to reduce brain volume across small mammals at high elevations but further experiments are needed to assess the generality of this conclusion and the nature of underlying mechanisms.
Asunto(s)
Muridae , Peromyscus , Animales , Ratas , Tamaño de los Órganos , Cráneo/diagnóstico por imagen , Cráneo/anatomía & histología , Cabeza/anatomía & histologíaRESUMEN
BACKGROUND: A high proportion of patients diagnosed with schizophrenia-spectrum disorders will at some point in their lives be assessed as not having the capacity to make their own decisions about pharmacological treatment or inpatient care ('capacity'). Few will be helped to regain it before these interventions proceed. This is partly because effective and safe methods to do so are lacking. Our aim is to accelerate their development by testing, for the first time in mental healthcare, the feasibility, acceptability and safety of running an 'Umbrella' trial. This involves running, concurrently and under one multi-site infrastructure, multiple assessor-blind randomised controlled trials, each of which is designed to examine the effect on capacity of improving a single psychological mechanism ('mechanism'). Our primary objectives are to demonstrate feasibility of (i) recruitment and (ii) data retention on the MacArthur Competence Assessment Tool-Treatment (MacCAT-T; planned primary outcome for a future trial) at end-of-treatment. We selected three mechanisms to test: 'self-stigma', low self-esteem and the 'jumping to conclusions' bias. Each is highly prevalent in psychosis, responsive to psychological intervention, and hypothesised to contribute to impaired capacity. METHODS: Sixty participants with schizophrenia-spectrum diagnoses, impaired capacity and one or more mechanism(s) will be recruited from outpatient and inpatient mental health services in three UK sites (Lothian, Scotland; Lancashire and Pennine; North West England). Those lacking capacity to consent to research could take part if the key criteria were met, including either proxy consent (Scotland) or favourable Consultee advice (England). They will be allocated to one of three randomised controlled trials, depending on which mechanism(s) they have. They will then be randomised to receive, over an 8-week period and in addition to treatment as usual (TAU), 6 sessions of either a psychological intervention which targets the mechanism, or 6 sessions of assessment of the causes of their incapacity (control condition). Participants are assessed at 0 (baseline), 8 (end-of-treatment) and 24 (follow-up) weeks post-randomisation using measures of capacity (MacCAT-T), mechanism, adverse events, psychotic symptoms, subjective recovery, quality of life, service use, anxiety, core schemata and depression. Two nested qualitative studies will be conducted; one to understand participant and clinician experiences and one to investigate the validity of MacCAT-T appreciation ratings. DISCUSSION: This will be the first Umbrella trial in mental healthcare. It will produce the first 3 single-blind randomised controlled trials of psychological interventions to support treatment decision-making in schizophrenia-spectrum disorder. Demonstrating feasibility will have significant implications not only for those seeking to support capacity in psychosis, but also for those who wish to accelerate the development of psychological interventions for other conditions. TRIAL REGISTRATION: ClinicalTrials.gov NCT04309435 . Pre-registered on 16 March 2020.
RESUMEN
Quantitative genetics (QG) analyses variation in traits of humans, other animals, or plants in ways that take account of the genealogical relatedness of the individuals whose traits are observed. "Classical" QG, where the analysis of variation does not involve data on measurable genetic or environmental entities or factors, is reformulated in this article using models that are free of hypothetical, idealized versions of such factors, while still allowing for defined degrees of relatedness among kinds of individuals or "varieties." The gene-free formulation encompasses situations encountered in human QG as well as in agricultural QG. This formulation is used to describe three standard assumptions involved in classical QG and provide plausible alternatives. Several concerns about the partitioning of trait variation into components and its interpretation, most of which have a long history of debate, are discussed in light of the gene-free formulation and alternative assumptions. That discussion is at a theoretical level, not dependent on empirical data in any particular situation. Additional lines of work to put the gene-free formulation and alternative assumptions into practice and to assess their empirical consequences are noted, but lie beyond the scope of this article. The three standard QG assumptions examined are: (1) partitioning of trait variation into components requires models of hypothetical, idealized genes with simple Mendelian inheritance and direct contributions to the trait; (2) all other things being equal, similarity in traits for relatives is proportional to the fraction shared by the relatives of all the genes that vary in the population (e.g., fraternal or dizygotic twins share half of the variable genes that identical or monozygotic twins share); (3) in analyses of human data, genotype-environment interaction variance (in the classical QG sense) can be discounted. The concerns about the partitioning of trait variation discussed include: the distinction between traits and underlying measurable factors; the possible heterogeneity in factors underlying the development of a trait; the kinds of data needed to estimate key empirical parameters; and interpretations based on contributions of hypothetical genes; as well as, in human studies, the labeling of residual variance as a non-shared environmental effect; and the importance of estimating interaction variance.
Asunto(s)
Modelos Genéticos , Sitios de Carácter Cuantitativo , Interacción Gen-Ambiente , Variación Genética , HumanosRESUMEN
Introduction: Much of the published literature on suicide comes from high income countries. In countries such as India, female suicide rates exceed the global suicide rate and suicide rates found in their male counterparts. Results from previous studies indicate that factors related to suicide among men and women in India are different from those seen in high-income countries. To date, no reviews have considered the relationship between gender and suicide in India. Therefore, the aim of this scoping review is to provide a comprehensive understanding of existing literature reporting gender differences in suicide rates, methods, risk factors and antecedent factors in India by reviewing published studies. Method: A scoping review was conducted to map the existing literature on gender differences in suicide in India. To identify peer-reviewed publications, online databases PsycINFO and Embase were searched. The search terms were [suicid* AND India*]. The searches took place in November 2020 and May 2021, with no language restrictions. Articles published from 2014 onwards from India were included. Reference lists of selected studies were searched for studies that could meet the inclusion criteria. Results: This review identified 17 studies that met the inclusion criteria. The ratio between women and men who die by suicide in India is much lower than in high-income countries. Hanging was found to be a more commonly used method of suicide among both men and women, in comparison to high-income countries where hanging is more common among men. This review also identified several gaps in the literature. There were few studies that examined suicide among transgender Indians. There was limited literature on gender differences in risk and protective factors for suicide. Limitations such as the omission of a lack of gender-based analyses in several studies and under-reporting of suicide rates were identified. Conclusion: Understanding suicide within the context of individual countries is essential in designing culture-appropriate suicide prevention strategies. This review identified an urgent need to establish and evaluate suicide surveillance systems in India. Furthermore, additional research is warranted to understand suicide among individuals who identify outside the gender binary, and gender-specific risk and protective factors.
RESUMEN
Bats have been proposed as reliable bioindicators for monitoring bioaccumulation of elements and chemicals in natural and transformed ecosystems. Non-invasive methods are becoming more popular as research moves away from destructive methodologies. We present the first concentrations of 23 elements in Mops condylurus and Tadarida aegyptiaca (Molossidae) fur and blood from an opencast diamond mine and reference area using inductively coupled plasma mass spectrometry (ICP-MS). Concentrations of B, K, Rb and Cd in the bats' fur were significantly higher in the mining footprint compared to the reference area (P < 0.05). Other elements such as Zn and Hg were significantly higher in the blood of bats from the mining footprint than the reference area (P < 0.05), whereas Mn was significantly higher in the blood of bats from the reference area than from the mining footprint (P < 0.05). Sixteen of the 22 elements above the limit of detection, with the exception of Ba, were significantly higher in the fur samples than in the blood due to elements being incorporated over time into the fur as it grows, whereas blood reveals short-term exposure to elements. Concentrations of most of the elements were reasonably low except Al, Fe and Zn. In general, the element concentrations particularly in the fur samples were comparable with other international studies reporting elemental fur concentrations from anthropogenically impacted and natural areas. Fur and blood have the potential to be viable indicators of environmental toxicity, but research is required on toxic thresholds and physiological and ecological unknowns around element concentrations in bat tissues and organs.