69 research outputs found

    Negotiating the transition from adolescence to motherhood: Coping with prenatal and parenting stress in teenage mothers in Mulago hospital, Uganda

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    <p>Abstract</p> <p>Background</p> <p>Adolescence is a transitional stage from childhood to adulthood that is characterized by physical, physiological, psychosocial and behavioral changes that are influenced to a large extent by the age, culture and socialization of the individual. To explore what adolescent mothers perceive as their struggles during the period of transition from childhood to parenthood (through motherhood) and to describe strategies employed in coping with stress of pregnancy, motherhood and parenthood.</p> <p>Methods</p> <p>Longitudinal qualitative study involving twenty two in-depth interviews and six focus group discussions among pregnant adolescents who were followed from pregnant to delivery, from January 2004 to August 2005. Participant were selected by theoretical sampling and data was analyzed using grounded theory.</p> <p>Results</p> <p>Overall, young adolescents reported more anxiety, loss of self esteem (when they conceived), difficulty in accessing financial, moral and material support from parents or partners and stigmatization by health workers when they sought care from health facilities. Three strategies by which adolescent mothers cope with parenting and pregnancy stress that were described as utilizing opportunities (thriving), accommodating the challenges (bargaining and surviving), or failure (despairing), and varied in the extent to which they enabled adolescents to cope with the stress.</p> <p>Conclusion</p> <p>Adolescents on the transition to motherhood have variable needs and aspirations and utilize different strategies to cope with the stress of pregnancy and parenthood.</p

    Trackways Produced by Lungfish During Terrestrial Locomotion

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    Some primarily aquatic vertebrates make brief forays onto land, creating traces as they do. A lack of studies on aquatic trackmakers raises the possibility that such traces may be ignored or misidentified in the fossil record. Several terrestrial Actinopterygian and Sarcopterygian species have previously been proposed as possible models for ancestral tetrapod locomotion, despite extant fishes being quite distinct from Devonian fishes, both morphologically and phylogenetically. Although locomotion has been well-studied in some of these taxa, trackway production has not. We recorded terrestrial locomotion of a 35 cm African lungfish (Protopterus annectens; Dipnoi: Sarcopterygii) on compliant sediment. Terrestrial movement in the lungfish is accomplished by planting the head and then pivoting the trunk. Impressions are formed where the head impacts the substrate, while the body and fins produce few traces. The head leaves a series of alternating left-right impressions, where each impact can appear as two separate semi-circular impressions created by the upper and lower jaws, bearing some similarity to fossil traces interpreted as footprints. Further studies of trackways of extant terrestrial fishes are necessary to understand the behavioural repertoire that may be represented in the fossil track record

    Oldest pathology in a tetrapod bone illuminates the origin of terrestrial vertebrates

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    The origin of terrestrial tetrapods was a key event in vertebrate evolution, yet how and when it occurred remains obscure, due to scarce fossil evidence. Here, we show that the study of palaeopathologies, such as broken and healed bones, can help elucidate poorly understood behavioural transitions such as this. Using high-resolution finite element analysis, we demonstrate that the oldest known broken tetrapod bone, a radius of the primitive stem tetrapod Ossinodus pueri from the mid-Viséan (333 million years ago) of Australia, fractured under a high-force, impact-type loading scenario. The nature of the fracture suggests that it most plausibly occurred during a fall on land. Augmenting this are new osteological observations, including a preferred directionality to the trabecular architecture of cancellous bone. Together, these results suggest that Ossinodus, one of the first large (&gt;2m length) tetrapods, spent a significant proportion of its life on land. Our findings have important implications for understanding the temporal, biogeographical and physiological contexts under which terrestriality in vertebrates evolved. They push the date for the origin of terrestrial tetrapods further back into the Carboniferous by at least two million years. Moreover, they raise the possibility that terrestriality in vertebrates first evolved in large tetrapods in Gondwana rather than in small European forms, warranting a re-evaluation of this important evolutionary event

    Clinical factors associated with fatigue over time in paediatric oncology patients receiving chemotherapy

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    The purpose of this study was to investigate the relationships between clinical factors (including haemoglobin value, chemotherapeutic agents, and corticosteroid use) and changing patterns of fatigue before and for the next 10 days following the start of a new round of chemotherapy in children with cancer. A prospective longitudinal design was used to collect data from 48 paediatric oncology patients who were about to begin a new round of chemotherapy and their parents. Fatigue levels were assessed using multidomain questionnaires with three categories of patient self-report (including ‘General Fatigue', ‘Sleep/Rest Fatigue', and ‘Cognitive Fatigue') and four categories of parent proxy-report (including ‘Lack of Energy', ‘Unable to Function', ‘Altered Sleep', and ‘Altered Mood'). The findings suggest that fatigue from both patient self-report and parent proxy-report changed significantly over time. The major findings from this study are that patients have more problems with fatigue in the first few days after the start of a cycle of chemotherapy. Corticosteroid use and haemoglobin value were associated with significant increases in fatigue that were sustained for several days and reached the highest level of fatigue at day 5 for those receiving concurrent steroids. The association of chemotherapeutic agents with fatigue varied between patient self-report and parent report, but the type of chemotherapeutic agents used was not associated with most changes in fatigue

    Waist circumference, abdominal obesity, and depression among overweight and obese U.S. adults: national health and nutrition examination survey 2005-2006

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    <p>Abstract</p> <p>Background</p> <p>Obesity is associated with an increased risk of mental illness; however, evidence linking body mass index (BMI)-a measure of overall obesity, to mental illness is inconsistent. The objective of this study was to examine the association of depressive symptoms with waist circumference or abdominal obesity among overweight and obese U.S. adults.</p> <p>Methods</p> <p>A cross-sectional, nationally representative sample from the 2005-2006 National Health and Nutrition Examination Survey was used. We analyzed the data from 2,439 U.S. adults (1,325 men and 1,114 nonpregnant women) aged ≥ 20 years who were either overweight or obese with BMI of ≥ 25.0 kg/m<sup>2</sup>. Abdominal obesity was defined as waist circumference of > 102 cm for men and > 88 cm for women. Depressive symptoms (defined as having major depressive symptoms or moderate-to-severe depressive symptoms) were assessed by the Patient Health Questionnaire-9 diagnostic algorithm. The prevalence and the odds ratios (ORs) with 95% confidence intervals (CIs) for having major depressive symptoms and moderate-to-severe depressive symptoms were estimated using logistic regression analysis.</p> <p>Results</p> <p>After multivariate adjustment for demographics and lifestyle factors, waist circumference was significantly associated with both major depressive symptoms (OR: 1.03, 95% CI: 1.01-1.05) and moderate-to-severe depressive symptoms (OR: 1.02, 95% CI: 1.01-1.04), and adults with abdominal obesity were significantly more likely to have major depressive symptoms (OR: 2.18, 95% CI: 1.35-3.59) or have moderate-to-severe depressive symptoms (OR: 2.56, 95% CI: 1.34-4.90) than those without. These relationships persisted after further adjusting for coexistence of multiple chronic conditions and persisted in participants who were overweight (BMI: 25.0-< 30.0 kg/m<sup>2</sup>) when stratified analyses were conducted by BMI status.</p> <p>Conclusion</p> <p>Among overweight and obese U.S. adults, waist circumference or abdominal obesity was significantly associated with increased likelihoods of having major depressive symptoms or moderate-to-severe depressive symptoms. Thus, mental health status should be monitored and evaluated in adults with abdominal obesity, particularly in those who are overweight.</p

    Phylogenetic and environmental context of a Tournaisian tetrapod fauna

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    The end-Devonian to mid-Mississippian time interval has long been known for its depauperate palaeontological record, especially for tetrapods. This interval encapsulates the time of increasing terrestriality among tetrapods, but only two Tournaisian localities previously produced tetrapod fossils. Here we describe five new Tournaisian tetrapods (Perittodus apsconditus\textit{Perittodus apsconditus}, Koilops herma\textit{Koilops herma}, Ossirarus kierani\textit{Ossirarus kierani}, Diploradus austiumensis\textit{Diploradus austiumensis} and Aytonerpeton microps\textit{Aytonerpeton microps}) from two localities in their environmental context. A phylogenetic analysis retrieved three taxa as stem tetrapods, interspersed among Devonian and Carboniferous forms, and two as stem amphibians, suggesting a deep split among crown tetrapods. We also illustrate new tetrapod specimens from these and additional localities in the Scottish Borders region. The new taxa and specimens suggest that tetrapod diversification was well established by the Tournaisian. Sedimentary evidence indicates that the tetrapod fossils are usually associated with sandy siltstones overlying wetland palaeosols. Tetrapods were probably living on vegetated surfaces that were subsequently flooded. We show that atmospheric oxygen levels were stable across the Devonian/Carboniferous boundary, and did not inhibit the evolution of terrestriality. This wealth of tetrapods from Tournaisian localities highlights the potential for discoveries elsewhere.NERC consortium grants NE/J022713/1 (Cambridge), NE/J020729/1 (Leicester), NE/J021067/1 (BGS), NE/J020621/1 (NMS) and NE/J021091/1 (Southampton

    Oxygen as a Driver of Early Arthropod Micro-Benthos Evolution

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    BACKGROUND: We examine the physiological and lifestyle adaptations which facilitated the emergence of ostracods as the numerically dominant Phanerozoic bivalve arthropod micro-benthos. METHODOLOGY/PRINCIPAL FINDINGS: The PO(2) of modern normoxic seawater is 21 kPa (air-equilibrated water), a level that would cause cellular damage if found in the tissues of ostracods and much other marine fauna. The PO(2) of most aquatic breathers at the cellular level is much lower, between 1 and 3 kPa. Ostracods avoid oxygen toxicity by migrating to waters which are hypoxic, or by developing metabolisms which generate high consumption of O(2). Interrogation of the Cambrian record of bivalve arthropod micro-benthos suggests a strong control on ecosystem evolution exerted by changing seawater O(2) levels. The PO(2) of air-equilibrated Cambrian-seawater is predicted to have varied between 10 and 30 kPa. Three groups of marine shelf-dwelling bivalve arthropods adopted different responses to Cambrian seawater O(2). Bradoriida evolved cardiovascular systems that favoured colonization of oxygenated marine waters. Their biodiversity declined during intervals associated with black shale deposition and marine shelf anoxia and their diversity may also have been curtailed by elevated late Cambrian (Furongian) oxygen-levels that increased the PO(2) gradient between seawater and bradoriid tissues. Phosphatocopida responded to Cambrian anoxia differently, reaching their peak during widespread seabed dysoxia of the SPICE event. They lacked a cardiovascular system and appear to have been adapted to seawater hypoxia. As latest Cambrian marine shelf waters became well oxygenated, phosphatocopids went extinct. Changing seawater oxygen-levels and the demise of much of the seabed bradoriid micro-benthos favoured a third group of arthropod micro-benthos, the ostracods. These animals adopted lifestyles that made them tolerant of changes in seawater O(2). Ostracods became the numerically dominant arthropod micro-benthos of the Phanerozoic. CONCLUSIONS/SIGNIFICANCE: Our work has implications from an evolutionary context for understanding how oxygen-level in marine ecosystems drives behaviour

    Homeotic Evolution in the Mammalia: Diversification of Therian Axial Seriation and the Morphogenetic Basis of Human Origins

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    Despite the rising interest in homeotic genes, little has been known about the course and pattern of evolution of homeotic traits across the mammalian radiation. An array of emerging and diversifying homeotic gradients revealed by this study appear to generate new body plans and drive evolution at a large scale.This study identifies and evaluates a set of homeotic gradients across 250 extant and fossil mammalian species and their antecedents over a period of 220 million years. These traits are generally expressed as co-linear gradients along the body axis rather than as distinct segmental identities. Relative position or occurrence sequence vary independently and are subject to polarity reversal and mirroring. Five major gradient modification sets are identified: (1)--quantitative changes of primary segmental identity pattern that appeared at the origin of the tetrapods ; (2)--frame shift relation of costal and vertebral identity which diversifies from the time of amniote origins; (3)--duplication, mirroring, splitting and diversification of the neomorphic laminar process first commencing at the dawn of mammals; (4)--emergence of homologically variable lumbar lateral processes upon commencement of the radiation of therian mammals and ; (5)--inflexions and transpositions of the relative position of the horizontal septum of the body and the neuraxis at the emergence of various orders of therian mammals. Convergent functional changes under homeotic control include laminar articular engagement with septo-neural transposition and ventrally arrayed lumbar transverse process support systems.Clusters of homeotic transformations mark the emergence point of mammals in the Triassic and the radiation of therians in the Cretaceous. A cluster of homeotic changes in the Miocene hominoid Morotopithecus that are still seen in humans supports establishment of a new "hominiform" clade and suggests a homeotic origin for the human upright body plan

    C-type lectin-like domains in Fugu rubripes

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    BACKGROUND: Members of the C-type lectin domain (CTLD) superfamily are metazoan proteins functionally important in glycoprotein metabolism, mechanisms of multicellular integration and immunity. Three genome-level studies on human, C. elegans and D. melanogaster reported previously demonstrated almost complete divergence among invertebrate and mammalian families of CTLD-containing proteins (CTLDcps). RESULTS: We have performed an analysis of CTLD family composition in Fugu rubripes using the draft genome sequence. The results show that all but two groups of CTLDcps identified in mammals are also found in fish, and that most of the groups have the same members as in mammals. We failed to detect representatives for CTLD groups V (NK cell receptors) and VII (lithostathine), while the DC-SIGN subgroup of group II is overrepresented in Fugu. Several new CTLD-containing genes, highly conserved between Fugu and human, were discovered using the Fugu genome sequence as a reference, including a CSPG family member and an SCP-domain-containing soluble protein. A distinct group of soluble dual-CTLD proteins has been identified, which may be the first reported CTLDcp group shared by invertebrates and vertebrates. We show that CTLDcp-encoding genes are selectively duplicated in Fugu, in a manner that suggests an ancient large-scale duplication event. We have verified 32 gene structures and predicted 63 new ones, and make our annotations available through a distributed annotation system (DAS) server and their sequences as additional files with this paper. CONCLUSIONS: The vertebrate CTLDcp family was essentially formed early in vertebrate evolution and is completely different from the invertebrate families. Comparison of fish and mammalian genomes revealed three groups of CTLDcps and several new members of the known groups, which are highly conserved between fish and mammals, but were not identified in the study using only mammalian genomes. Despite limitations of the draft sequence, the Fugu rubripes genome is a powerful instrument for gene discovery and vertebrate evolutionary analysis. The composition of the CTLDcp superfamily in fish and mammals suggests that large-scale duplication events played an important role in the evolution of vertebrates
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