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We analysed thirty-five 400-m2 plots encompassing forest, savanna and intermediate vegetation types in an ecotonal area in Ghana, West Africa. Across all plots, fire frequency was over a period of 15 years relatively uniform (once in 2–4 years). Although woodlands were dominated by species typically associated with savanna-type formations, and with forest formations dominated by species usually associated with closed canopies, these associations were non-obligatory and with a discrete non-specialized species grouping also identified. Across all plots, crown area index, stem basal area and above-ground biomass were positively associated with higher soil exchangeable potassium and silt contents: this supporting recent suggestions of interplays between potassium and soil water storage potential as a significant influence on tropical vegetation structure. We also found an average NDVI cover increase of ~0.15% year−1 (1984–2011) with plots dominated by non-specialized species increasing more than those dominated by either forest- or savanna-affiliated species. Our results challenge the traditional view of a simple forest vs. savanna dichotomy controlled by fire, and with our newly identified third non-specialized species grouping also potentially important in understanding ecotonal responses to climate change.
This study provides a morphological and phylogenetic characterization of two novel species of the order Haplosporida (Haplosporidium carcini n. sp., and H. cranc n. sp.) infecting the common shore crab Carcinus maenas collected at one location in Swansea Bay, South Wales, UK. Both parasites were observed in the haemolymph, gills and hepatopancreas. The prevalence of clinical infections (i.e. parasites seen directly in fresh haemolymph preparations) was low, at ~1%, whereas subclinical levels, detected by polymerase chain reaction, were slightly higher at ~2%. Although no spores were found in any of the infected crabs examined histologically (n = 334), the morphology of monokaryotic and dikaryotic unicellular stages of the parasites enabled differentiation between the two new species. Phylogenetic analyses of the new species based on the small subunit (SSU) rDNA gene placed H. cranc in a clade of otherwise uncharacterized environmental sequences from marine samples, and H. carcini in a clade with other crustacean-associated lineages.
A new carbon isotope record for two high-latitude sedimentary successions that span the Jurassic–Cretaceous boundary interval in the Sverdrup Basin of Arctic Canada is presented. This study, combined with other published Arctic data, shows a large negative isotopic excursion of organic carbon (δ13Corg) of 4‰ (V-PDB) and to a minimum of −30.7‰ in the probable middle Volgian Stage. This is followed by a return to less negative values of c. −27‰. A smaller positive excursion in the Valanginian Stage of c. 2‰, reaching maximum values of −24.6‰, is related to the Weissert Event. The Volgian isotopic trends are consistent with other high-latitude records but do not appear in δ13Ccarb records of Tethyan Tithonian strata. In the absence of any obvious definitive cause for the depleted δ13Corg anomaly, we suggest several possible contributing factors. The Sverdrup Basin and other Arctic areas may have experienced compositional evolution away from open-marine δ13C values during the Volgian Age due to low global or large-scale regional sea levels, and later become effectively coupled to global oceans by Valanginian time when sea level rose. A geologically sudden increase in volcanism may have caused the large negative δ13Corg values seen in the Arctic Volgian records but the lack of precise geochronological age control for the Jurassic–Cretaceous boundary precludes direct comparison with potentially coincident events, such as the Shatsky Rise. This study offers improved correlation constraints and a refined C-isotope curve for the Boreal region throughout latest Jurassic and earliest Cretaceous time.
To develop and validate the Discrepancy-based Evidence for Loss of Thinking Abilities (DELTA) score. The DELTA score characterizes the strength of evidence for cognitive decline on a continuous spectrum using well-established psychometric principles for improving detection of cognitive changes.
DELTA score development used neuropsychological test scores from the Alzheimer’s Disease Neuroimaging Initiative (ADNI) cohort (two tests each from Memory, Executive Function, and Language domains). We derived regression-based normative reference scores using age, gender, years of education, and word-reading ability from robust cognitively normal ADNI participants. Discrepancies between predicted and observed scores were used for calculating the DELTA score (range 0–15). We validated DELTA scores primarily against longitudinal Clinical Dementia Rating-Sum of Boxes (CDR-SOB) and Functional Activities Questionnaire (FAQ) scores (baseline assessment through Year 3) using linear mixed models and secondarily against cross-sectional Alzheimer’s biomarkers.
There were 1359 ADNI participants with calculable baseline DELTA scores (age 73.7 ± 7.1 years, 55.4% female, 100% white/Caucasian). Higher baseline DELTA scores (stronger evidence of cognitive decline) predicted higher baseline CDR-SOB (ΔR2 = .318) and faster rates of CDR-SOB increase over time (ΔR2 = .209). Longitudinal changes in DELTA scores tracked closely and in the same direction as CDR-SOB scores (fixed and random effects of mean + mean-centered DELTA, ΔR2 > .7). Results were similar for FAQ scores. High DELTA scores predicted higher PET-Aβ SUVr (ρ = 324), higher CSF-pTau/CSF-Aβ ratio (ρ = .460), and demonstrated PPV > .9 for positive Alzheimer’s disease biomarker classification.
Data support initial development and validation of the DELTA score through its associations with longitudinal functional changes and Alzheimer’s biomarkers. We provide several considerations for future research and include an automated scoring program for clinical use.
Children from language minority (LM) environments speak a language at home that differs from that at school, are often from socioeconomically disadvantaged backgrounds, and are at risk for reading impairment. We evaluated the main effects and interaction of language status and phonological memory and awareness on reading disorder in 352 children from socioeconomically disadvantaged backgrounds. A significant phonological memory by language status interaction indicated that phonological memory problems were magnified in predicting reading impairment in children from LM versus English dominant (ED) homes. Among children without reading disorder, language minority status was unrelated to phonological processing.
It has been suggested that the risk of adverse perinatal outcomes in twin pregnancies is exacerbated by concomitant gestational diabetes mellitus (GDM). This study aimed to assess the risk incurred by twin pregnancy and by a diagnosis of GDM, separately, on the development of poor perinatal outcomes. A retrospective cohort study was conducted on all pregnant women at a tertiary center between 2016 and 2017. The impact of GDM and twin pregnancies on perinatal outcomes — birth weight above the 90th centile for gestational age, cesarean delivery, clinical neonatal hypoglycemia, and premature delivery (before 37 weeks’ gestation) — was assessed using univariate and multivariate analyses. Overall, 13,527 women were eligible for the study; 11,915 were uncomplicated singleton pregnancies; 1379 of these had GDM; 194 were twin pregnancies, and 39 of these had GDM. Univariate analyses showed that twin pregnancies were associated with a higher risk of all perinatal outcomes except macrosomia. In the multivariate analyses, twin pregnancy was a much higher predictor of cesarean delivery (OR 8.40, 95% CI [6.25, 11.49], p < .0001) and preterm birth (OR 58.82, 95% CI [31.25, 125], p < .0001) compared to GDM but GDM was a higher predictor of neonatal hypoglycemia (OR 4.87, 95% CI [3.74, 6.29], p < .0001). Twin pregnancy is more strongly associated with all adverse perinatal outcomes except macrosomia. GDM does not increase risk of adverse perinatal outcomes except for neonatal hypoglycemia.
The role that vitamin D plays in pulmonary function remains uncertain. Epidemiological studies reported mixed findings for serum 25-hydroxyvitamin D (25(OH)D)–pulmonary function association. We conducted the largest cross-sectional meta-analysis of the 25(OH)D–pulmonary function association to date, based on nine European ancestry (EA) cohorts (n 22 838) and five African ancestry (AA) cohorts (n 4290) in the Cohorts for Heart and Aging Research in Genomic Epidemiology Consortium. Data were analysed using linear models by cohort and ancestry. Effect modification by smoking status (current/former/never) was tested. Results were combined using fixed-effects meta-analysis. Mean serum 25(OH)D was 68 (sd 29) nmol/l for EA and 49 (sd 21) nmol/l for AA. For each 1 nmol/l higher 25(OH)D, forced expiratory volume in the 1st second (FEV1) was higher by 1·1 ml in EA (95 % CI 0·9, 1·3; P<0·0001) and 1·8 ml (95 % CI 1·1, 2·5; P<0·0001) in AA (Prace difference=0·06), and forced vital capacity (FVC) was higher by 1·3 ml in EA (95 % CI 1·0, 1·6; P<0·0001) and 1·5 ml (95 % CI 0·8, 2·3; P=0·0001) in AA (Prace difference=0·56). Among EA, the 25(OH)D–FVC association was stronger in smokers: per 1 nmol/l higher 25(OH)D, FVC was higher by 1·7 ml (95 % CI 1·1, 2·3) for current smokers and 1·7 ml (95 % CI 1·2, 2·1) for former smokers, compared with 0·8 ml (95 % CI 0·4, 1·2) for never smokers. In summary, the 25(OH)D associations with FEV1 and FVC were positive in both ancestries. In EA, a stronger association was observed for smokers compared with never smokers, which supports the importance of vitamin D in vulnerable populations.
Although there is extensive evidence that problematic alcohol use is associated with smaller hippocampal volume, the typical cross-sectional study design cannot determine whether hippocampal deviations reflect pre-existing liability toward problematic alcohol use or instead reflect an alcohol exposure-related effect. We used the co-twin control study design, which capitalizes upon differences within a twin pair in levels of drinking, to differentiate pre-existing liability from an effect of alcohol exposure.
The sample included 100 female twins, prospectively assessed from ages 11 to 24. Problematic alcohol use was assessed dimensionally and included indicators of quantity, frequency, and density of alcohol use and intoxication. Hippocampal volume was assessed using magnetic resonance imaging.
Problematic alcohol use (proximal and cumulative) was associated with significantly smaller left and right hippocampal volume. Follow-up co-twin control analyses that partitioned individual-level alcohol effects into pre-existing, familial liability and non-shared alcohol exposure-related effects indicated that this association reflected alcohol exposure. Greater alcohol using twins had smaller hippocampal volume relative to lesser alcohol using co-twins, beyond effects of their shared genetic and environmental liability toward problematic alcohol use. Results held accounting for recent alcohol use, other substance use, externalizing and internalizing psychopathology, personality traits, trauma exposure, and menstrual phase.
The association between problematic alcohol use and smaller hippocampal volume likely reflects an alcohol exposure-related effect. Differentiating pre-existing brain deviations that confer risk for problematic alcohol use from those that reflect effects of alcohol on the brain will inform etiological models of addiction and further prevention and intervention efforts.
Palliative care for nursing home residents with advanced dementia is often sub-optimal due to poor communication and limited care planning. In a cluster randomized controlled trial, registered nurses (RNs) from 10 nursing homes were trained and funded to work as Palliative Care Planning Coordinators (PCPCs) to organize family case conferences and mentor staff. This qualitative sub-study aimed to explore PCPC and health professional perceptions of the benefits of facilitated case conferencing and identify factors influencing implementation.
Semi-structured interviews were conducted with the RNs in the PCPC role, other members of nursing home staff, and physicians who participated in case conferences. Analysis was conducted by two researchers using a thematic framework approach.
Interviews were conducted with 11 PCPCs, 18 other nurses, eight allied health workers, and three physicians. Perceived benefits of facilitated case conferencing included better communication between staff and families, greater multi-disciplinary involvement in case conferences and care planning, and improved staff attitudes and capabilities for dementia palliative care. Key factors influencing implementation included: staffing levels and time; support from management, staff and physicians; and positive family feedback.
The facilitated approach explored in this study addressed known barriers to case conferencing. However, current business models in the sector make it difficult for case conferencing to receive the required levels of nursing qualification, training, and time. A collaborative nursing home culture and ongoing relationships with health professionals are also prerequisites for success. Further studies should document resident and family perceptions to harness consumer advocacy.
Efforts to address health disparities and achieve health equity are critically dependent on the development of a diverse research workforce. However, many researchers from underrepresented backgrounds face challenges in advancing their careers, securing independent funding, and finding the mentorship needed to expand their research.
Faculty from the University of Maryland at College Park and the University of Wisconsin-Madison developed and evaluated an intensive week-long research and career-development institute—the Health Equity Leadership Institute (HELI)—with the goal of increasing the number of underrepresented scholars who can sustain their ongoing commitment to health equity research.
In 2010-2016, HELI brought 145 diverse scholars (78% from an underrepresented background; 81% female) together to engage with each other and learn from supportive faculty. Overall, scholar feedback was highly positive on all survey items, with average agreement ratings of 4.45-4.84 based on a 5-point Likert scale. Eighty-five percent of scholars remain in academic positions. In the first three cohorts, 73% of HELI participants have been promoted and 23% have secured independent federal funding.
HELI includes an evidence-based curriculum to develop a diverse workforce for health equity research. For those institutions interested in implementing such an institute to develop and support underrepresented early stage investigators, a resource toolbox is provided.
Based on seven measured sections from Svalbard, the marine strata of the Permian Kapp Starostin Formation are arranged into seven transgressive–regressive sequences (TR1–TR7) of c. 4–5 Ma average duration, each bound by a maximum regressive surface. Facies, including heterozoan-dominated limestones, spiculitic cherts, sandstones, siltstones and shales, record deposition within inner, middle and outer shelf areas. The lowermost sequence, TR1, comprises most of the basal Vøringen Member, which records a transgression across the Gipshuken Formation following a hiatus of unknown duration. Temperate to cold, storm-dominated facies established in inner to middle shelf areas between the latest Artinskian and Kungurian. Prolonged deepening during sequences TR2 and TR3 was succeeded by a long-term shallowing-upward trend that lasted until the latest Permian (TR4–TR7). A major depocentre existed in central and western Spitsbergen while to the north, Dickson Land remained a shallow platform, leading to a shallow homoclinal ramp in NE Spitsbergen and Nordaustlandet. The Middle Permian extinction (late Capitanian) is recorded near the base of TR6 in deeper parts of the basin only; elsewhere this sequence is not recorded. Likewise the youngest sequence, TR7, extending to the upper formational contact of latest Permian age, is found only in the basin depocentre. Comparison with age-equivalent strata in the Sverdrup Basin of Canada reveals a remarkably similar depositional history, with, for example, two (third-order) sea-level cycles recorded in the Late Permian of both regions, in keeping with the global record. Sequence stratigraphy may therefore be a powerful correlative tool for onshore and offshore Permian deposits across NW Pangaea.
The State of Qatar experienced a sandstorm on the night of April 1, 2015, lasting approximately 12 hours, with winds of more than 100 km/h and average particulate matter of approximately 10 μm in diameter. The emergency department (ED) of the main tertiary hospital in Qatar managed 62% of the total emergency calls and those of higher triage order. The peak load of patients during the event manifested approximately 6 hours after the onset. The Major Emergency Command Centre of the hospital ensured the department was maximally organized in terms of disaster management, and established protocols were brought into action. Multiple timely meetings were convened in efforts to effectively execute plans that included rapid emergency medical services handover time, resourcing staff, maximizing bed space, preventing dust entry in the ED, bypassing certain administrative processes, canceling day-surgeries that did not affect inpatient morbidity, and procuring additional respiratory equipment. Patients arrived mainly with exacerbations of asthma and respiratory distress, ophthalmic emergencies, and vehicular trauma; surprisingly, the incidence of pedestrian injuries did not vary. (Disaster Med Public Health Preparedness. 2017;11:227–238)
Fontan survivors have depressed cardiac index that worsens over time. Serum biomarker measurement is minimally invasive, rapid, widely available, and may be useful for serial monitoring. The purpose of this study was to identify biomarkers that correlate with lower cardiac index in Fontan patients.
Methods and results
This study was a multi-centre case series assessing the correlations between biomarkers and cardiac magnetic resonance-derived cardiac index in Fontan patients ⩾6 years of age with biochemical and haematopoietic biomarkers obtained ±12 months from cardiac magnetic resonance. Medical history and biomarker values were obtained by chart review. Spearman’s Rank correlation assessed associations between biomarker z-scores and cardiac index. Biomarkers with significant correlations had receiver operating characteristic curves and area under the curve estimated. In total, 97 cardiac magnetic resonances in 87 patients met inclusion criteria: median age at cardiac magnetic resonance was 15 (6–33) years. Significant correlations were found between cardiac index and total alkaline phosphatase (−0.26, p=0.04), estimated creatinine clearance (0.26, p=0.02), and mean corpuscular volume (−0.32, p<0.01). Area under the curve for the three individual biomarkers was 0.63–0.69. Area under the curve for the three-biomarker panel was 0.75. Comparison of cardiac index above and below the receiver operating characteristic curve-identified cut-off points revealed significant differences for each biomarker (p<0.01) and for the composite panel [median cardiac index for higher-risk group=2.17 L/minute/m2 versus lower-risk group=2.96 L/minute/m2, (p<0.01)].
Higher total alkaline phosphatase and mean corpuscular volume as well as lower estimated creatinine clearance identify Fontan patients with lower cardiac index. Using biomarkers to monitor haemodynamics and organ-specific effects warrants prospective investigation.
Negative symptoms are perhaps the most disabling feature of schizophrenia. Their pathogenesis remains poorly understood and it has been difficult to assess their development over time with imaging techniques.
To examine, using tensor-based structural imaging techniques, whether there are regions of progressive grey matter volume change associated with the development of negative symptoms.
A total of 43 adolescents at risk of psychosis were examined using magnetic resonance imaging and whole brain tensor-based morphometry at two time points, 6 years apart.
When comparing the individuals with significant negative symptoms with the remaining participants, we identified five regions of significant grey matter tissue loss over the 6-year period. These regions included the left temporal lobe, the left cerebellum, the left posterior cingulate and the left inferior parietal sulcus.
Negative symptoms are associated with longitudinal grey matter tissue loss. The regions identified include areas associated with psychotic symptoms more generally but also include regions uniquely associated with negative symptoms.