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Visual representations are essential to design. Data-rich representations such as systems visualisations are gaining prominence in engineering practice. However, as such visualisations are often developed ad-hoc, we propose more systematically to link visual tasks with design-specific tasks for which the visualisations are used. Whereas research on such linking focuses mostly on CAD models and sketches, no such studies are yet available for systems visualisations. Thus, this paper introduces a typology of visual tasks from the Information Visualisation field to aid the development of systems visualisations in design. To build a visualisation using the typology, a case study with engineering students developing an autonomous robot was conducted. Through interviews and analysis of product representations used, design-specific tasks were identified and decomposed into visual tasks. Then, a visualisation that assisted the team in performing their design activities was created. Results illustrate the benefits of using such a typology to describe visual tasks and generate systems visualisations. The study suggests implications for researchers studying visual representations in design as well as for developers of systems visualisations.
Iron deficiency (ID) in early life is associated with morbidities. Most fetal iron required for infant growth is acquired in the third trimester from maternal iron store. However, how prenatal iron level affects ferritin level in early infancy remains controversial. This study aimed to examine the associations between maternal ferritin levels and cord blood serum ferritin (CBSF) and to compare the ferritin levels between different feeding practices in early infancy. Healthy Chinese mothers with uncomplicated pregnancy and their infants were followed up at 3 months post-delivery for questionnaire completion and infant blood collection. Infants who were predominantly breastfed and those who were predominantly formula fed were included in this analysis. Serum ferritin levels were measured in maternal blood samples collected upon delivery, cord blood and infant blood samples at 3 months of age. Ninety-seven mother–baby dyads were included. Maternal ID is common (56 %) while the CBSF levels were significantly higher than maternal ferritin levels. Only three infants (3 %) had ID at 3 months of age. There were no significant correlations between maternal ferritin levels with CBSF (r 0·168, P = 0·108) nor with infant ferritin levels at 3 months of age (r 0·023, P = 0·828). Infant ferritin levels at 3 months were significantly and independently associated with CBSF (P = 0·007) and birth weight (P < 0·001) after adjusting for maternal age, parity, maternal education, infant sex and feeding practice. In conclusion, maternal ID was common upon delivery. However, maternal ferritin levels were not significantly associated with CBSF concentrations nor infant ferritin concentrations at 3 months of age.
During the first wave of the severe acute respiratory syndrome-coronavirus-2 epidemic in the Netherlands, notifications consisted mostly of patients with relatively severe disease. To enable real-time monitoring of the incidence of mild coronavirus disease 2019 (COVID-19) – for which medical consultation might not be required – the Infectieradar web-based syndromic surveillance system was launched in mid-March 2020. Our aim was to quantify associations between Infectieradar participant characteristics and the incidence of self-reported COVID-19-like illness. Recruitment for this cohort study was via a web announcement. After registering, participants completed weekly questionnaires, reporting the occurrence of a set of symptoms. The incidence rate of COVID-19-like illness was estimated and multivariable Poisson regression used to estimate the relative risks associated with sociodemographic variables, lifestyle factors and pre-existing medical conditions. Between 17 March and 24 May 2020, 25 663 active participants were identified, who reported 7060 episodes of COVID-19-like illness over 131 404 person-weeks of follow-up. The incidence rate declined over the analysis period, consistent with the decline in notified cases. Male sex, age 65+ years and higher education were associated with a significantly lower COVID-19-like illness incidence rate (adjusted rate ratios (RRs) of 0.80 (95% CI 0.76–0.84), 0.77 (0.70–0.85), 0.84 (0.80–0.88), respectively) and the baseline characteristics ever-smoker, asthma, allergies, diabetes, chronic lung disease, cardiovascular disease and children in the household were associated with a higher incidence (RRs of 1.11 (1.04–1.19) to 1.69 (1.50–1.90)). Web-based syndromic surveillance has proven useful for monitoring the temporal trends in, and risk factors associated with, the incidence of mild disease. Increased relative risks observed for several patient factors could reflect a combination of exposure risk, susceptibility to infection and propensity to report symptoms.
The global total-$f$ gyrokinetic particle-in-cell code XGC, used to study transport in magnetic fusion plasmas or to couple with a core gyrokinetic code while functioning as an edge gyrokinetic code, implements a five-dimensional continuum grid to perform the dissipative operations, such as plasma collisions, or to exchange the particle distribution function information with a core code. To transfer the distribution function between marker particles and a rectangular two-dimensional velocity-space grid, XGC employs a bilinear mapping. The conservation of particle density and momentum is accurate enough in this bilinear operation, but the error in the particle energy conservation can become undesirably large and cause non-negligible numerical heating in a steep edge pedestal. In the present work we update XGC to use a novel mapping technique, based on the calculation of a pseudo-inverse, to exactly preserve moments up to the order of the discretization space. We describe the details of the implementation and we demonstrate the reduced interpolation error for a tokamak test plasma using first- and second-order elements with the pseudo-inverse method and comparing with the bilinear mapping.
Most antidepressants have a delayed onset of action and must be administered for several weeks to generate therapeutic effects. Trazodone is a serotonin antagonist and reuptake inhibitor approved for the treatment of major depressive disorder. The once-a-day (OAD) formulation of trazodone has an improved tolerability profile compared to its conventional formulations. In this study, we systematically reviewed the evidence available for the antidepressant efficacy and early improvement in depressive symptoms with trazodone OAD treatment.
We conducted a PubMed database search for randomized controlled trials published from 2005 to 2020.
Two studies, a placebo-controlled and an active-comparator (venlafaxine extended-release or XR) study were found. Both the studies demonstrated that trazodone exhibits antidepressant activity at a starting dose of 150 mg/day and results in statistically significant greater reduction in Hamilton Depression Rating Scale (HAM-D17) scores within 1 week of starting treatment compared to placebo or venlafaxine XR (P < .05). Trazodone also resulted in significant early improvement in the HAM-D17 sleep disturbance factor compared to placebo or venlafaxine XR at day 7 (P < .05). This clinical effect is supported by in vitro proprietary data for the affinity of trazodone for different target receptors. Activity at these receptors may underlie trazodone’s fast antidepressant action.
Trazodone, if properly dosed, can be an effective antidepressant with early onset of action and good tolerability. Future studies designed to specifically evaluate onset and timing of improvement of depressive symptoms remain necessary to confirm and extend these results.
ABSTRACT IMPACT: Advanced cardiac magnetic resonance imaging techniques can help to protect cancer patients from cardiotoxicity from immunotherapy with a more sensitive assessment of cardiac function with strain imaging for detection of abnormal cardiac function in the setting of normal left ventricular ejection fraction. OBJECTIVES/GOALS: Immune checkpoint inhibitors (ICI) are associated with fatal cardiotoxicity. Cardiac magnetic resonance (CMR) imaging can assess ICI-associated cardiotoxicity, but the utility of CMR strain imaging is unknown. We present a study of patients with ICI-associated cardiotoxicity evaluated with fast strain-encoded (fast-SENC) CMR. METHODS/STUDY POPULATION: This prospective study was approved by the institutional IRB and informed consent was obtained from 15 patients (5 patients with ICI-associated cardiotoxicity, 10 controls patients) between August 2018 and January 2020. All patients with ICI-associated cardiotoxicity had abnormal troponin values and evidence of cardiotoxicity on T2-weighted and/or delayed enhancement CMR images. All patients underwent standard CMR assessment with steady state free precession cine images, T2-weighted imaging, and delayed gadolinium enhancement imaging. Additionally, free-breathing SENC images were obtained and then processed by a team of blinded cardiovascular imaging specialists using Myostrain software (Morrisville, USA). RESULTS/ANTICIPATED RESULTS: Left ventricular ejection fraction (LVEF) was normal in both groups (ï,³53%). Global longitudinal LV strain was significantly depressed in the ICI cardiotoxicity group versus controls (-12.8 ±3.2% vs. -16.6 ±1.9%, p=0.028). The average global circumferential LV strain was mildly abnormal (defined as strain > -17) in the ICI cardiotoxicity group and trended towards a higher value compared with controls (-16.0 ±2.6% vs -17.8 ±1.7%, p=0.103). The average number of dysfunctional segments (defined as strain > -10) was significantly higher in the ICI cardiotoxicity group (6.8 ±4.2 vs. 1.0 ±1.7, p=0.017). The proportion of abnormal myocardium was higher in the ICI cardiotoxicity group (66 ±21% vs. 45 ±18%, p=0.050), as well as the proportion of myocardium found to be dysfunctional (26 ±22% vs. 3.0 ±6.0%, p=0.041). DISCUSSION/SIGNIFICANCE OF FINDINGS: Despite having preserved LVEF, patients who met criteria for ICI-associated cardiotoxicity had both global and regional abnormal LV strain. Fast-SENC imaging may provide a sensitive tool for detection of early cardiotoxicity in this population. This study is limited by its small cohort and a larger prospective study would be of value.
To assess researchers’ experiences working with community advisory boards (CABs) and perceptions of how community member stakeholder feedback impacted the research.
Individual interviews were conducted with researchers (n= 34) who had presented their research to a Mayo Clinic CAB (at MN, AZ, or FL) from 2014 to 2017, with an average interview duration of 10–15 min. Researchers were asked “In what ways did the feedback you received from the CAB influence your research?” A validated, structured, 7-item interview was used to assess domains of the potential influence that CABs had on the research: (1) pre-research (e.g., generated ideas), (2) infrastructure (e.g., budget preparation), (3) research design, (4) implementation (e.g., research recruitment), (5) analysis, (6) dissemination, and (7) post-research. A total mean score was calculated with a possible range of 0–7. In addition, open-ended examples and feedback from researchers in response to each domain were summarized for themes using content analysis.
Researchers reported that the CAB influenced research in the following domains: pre-research (24%), infrastructure (24%), study design (41%), implementation (41%), analysis (6%), dissemination (24%), and post-research activities (18%). The mean total score was = 1.8 (SD = 1.7, range: 0–6). Open-ended responses revealed major themes of CAB helpfulness in generating/refining ideas, identifying community partners, culturally tailored and targeted recruitment strategies, intervention design and delivery, and dissemination.
Findings from this preliminary evaluation indicate that despite positive experiences noted in open-ended feedback, the perceived quantitative impact of CAB feedback on the research was moderate. Bidirectional communication between researchers and community member stakeholders has the potential to make clinical and translational research more relevant and appropriate.
Background: Detection of unusual carbapenemase-producing organisms (CPOs) in a healthcare facility may signify broader regional spread. During investigation of a VIM-producing Pseudomonas aeruginosa (VIM-CRPA) outbreak in a long-term acute-care hospital in central Florida, enhanced surveillance identified VIM-CRPA from multiple facilities, denoting potential regional emergence. We evaluated infection control and performed screening for CPOs in skilled nursing facilities (SNFs) across the region to identify potential CPO reservoirs and improve practices. Methods: All SNFs in 2 central Florida counties were offered a facility-wide point-prevalence survey (PPS) for CPOs and a nonregulatory infection control consultation. PPSs were conducted using a PCR-based screening method; specimens with a carbapenemase gene detected were cultured to identify the organisms. Infection control assessments focused on direct observations of hand hygiene (HH), environmental cleaning, and the sink splash zone. Thoroughness of environmental cleaning was evaluated using fluorescent markers applied to 6 standardized high-touch surfaces in at least 2 rooms per facility. Results: Overall, 21 (48%) SNFs in the 2-county region participated; 18 conducted PPS. Bed size ranged from 40 to 391, 5 (24%) facilities were ventilator-capable SNFs (vSNFs), and 12 had short-stay inpatient rehabilitation units. Of 1,338 residents approached, 649 agreed to rectal screening, and 14 (2.2%) carried CPOs. CPO-colonized residents were from the ventilator-capable units of 3 vSNFs (KPC-CRE=7; KPC-CRPA=1) and from short-stay units of 2 additional facilities (VIM-CRPA, n = 5; KPC-CRE, n = 1). Among the 5 facilities where CPO colonization was identified, the prevalence ranged from 1.1% in a short-stay unit to 16.1% in a ventilator unit. All facilities had access to soap and water in resident bathrooms; 14 (67%) had alcohol-based hand rubs accessible. Overall, mean facility HH adherence was 52% (range, 37%–66%; mean observations per facility = 106) (Fig. 1). We observed the use of non–EPA-registered disinfectants and cross contamination from dirty to clean areas during environmental cleaning; the overall surface cleaning rate was 46% (n = 178 rooms); only 1 room had all 6 markers removed. Resident supplies were frequently stored in the sink splash zone. Conclusions: A regional assessment conducted in response to emergence of VIM-CRPA identified a relatively low CPO prevalence at participating SNFs; CPOs were primarily identified in vSNFs and among short-stay residents. Across facilities, we observed low adherence to core infection control practices that could facilitate spread of CPOs and other resistant organisms. In this region, targeting ventilator and short-stay units of SNFs for surveillance and infection control efforts may have the greatest prevention impact.
Tuberous sclerosis complex (TSC) is a rare genetic disorder that commonly leads to drug-resistant epilepsy in affected patients. This study aimed to determine whether the underlying genetic mutation (TSC1 vs. TSC2) predicts seizure outcomes following surgical treatments for epilepsy.
We retrospectively assessed TSC patients using the TSC Natural History Database core registry. Data review focused on outcomes in patients treated with surgical resection or vagus nerve stimulation.
A total of 42 patients with a TSC1 mutation, and 145 patients with a TSC2 mutation, were identified. We observed a distinct clinical phenotype: children with TSC2 mutations tended to be diagnosed with TSC at a younger age than those with a TSC1 mutation (p < 0.001), were more likely to have infantile spasms (p < 0.001), and to get to surgery at a later age (p = 0.003). Among this TSC2 cohort, seizure control following resective epilepsy surgery was achieved in less than half (47%) the study sample. In contrast, patients with TSC1 mutations tended to have more favorable postsurgical outcomes; seizure control was achieved in 66% of this group.
TSC2 mutations result in a more severe epilepsy phenotype that is also less responsive to resective surgery. It is important to consider this distinct clinical disposition when counseling families preoperatively with respect to seizure freedom. Larger samples are required to better characterize the independent effects of genetic mutation, infantile spasms, and duration of epilepsy as they relate to seizure control following resective or neuromodulatory epilepsy surgery.
In research and clinical practice, familial risk for depression and anxiety is often constructed as a simple Yes/No dichotomous family history (FH) indicator. However, this measure may not fully capture the liability to these conditions. This study investigated whether a continuous familial loading score (FLS), incorporating family- and disorder-specific characteristics (e.g. family size, prevalence of depression/anxiety), (i) is associated with a polygenic risk score (PRS) for major depression and with clinical/psychosocial vulnerabilities and (ii) still captures variation in clinical/psychosocial vulnerabilities after information on FH has been taken into account.
Data came from 1425 participants with lifetime depression and/or anxiety from the Netherlands Study of Depression and Anxiety. The Family Tree Inventory was used to determine FLS/FH indicators for depression and/or anxiety.
Persons with higher FLS had higher PRS for major depression, more severe depression and anxiety symptoms, higher disease burden, younger age of onset, and more neuroticism, rumination, and childhood trauma. Among these variables, FH was not associated with PRS, severity of symptoms, and neuroticism. After regression out the effect of FH from the FLS, the resulting residualized measure of FLS was still associated with severity of symptoms of depression and anxiety, rumination, and childhood trauma.
Familial risk for depression and anxiety deserves clinical attention due to its associated genetic vulnerability and more unfavorable disease profile, and seems to be better captured by a continuous score that incorporates family- and disorder-specific characteristics than by a dichotomous FH measure.
OBJECTIVES/GOALS: Severe malarial anemia due to Plasmodium falciparum is often accompanied by thrombocytopenia. Treatment includes transfusion of whole blood, which contains erythrocytes, platelets, and other blood components. The objective of the study was to assess the effect of whole blood transfusion on survival in children with severe falciparum malaria and to examine the potential interaction of thrombocytopenia with malaria mortality and transfusion response. METHODS/STUDY POPULATION: We analyzed a retrospective cohort of 842 hospitalized children in Zambia with severe malarial anemia (703 transfused, 139 not transfused due to stock-out or other reason). Severe malarial anemia was defined as a positive rapid diagnostic test or blood smear in combination with an admission hemoglobin concentration ≤5 g/dL. RESULTS/ANTICIPATED RESULTS: Mortality was 13% (94/703) in the transfused group and 24% (34/139) in the non-transfused group. Kaplan-Meier survival estimates stratified by transfusion status and thrombocytopenia (150,000/μL threshold) showed increased mortality in children with thrombocytopenia who did not undergo transfusion, with no differences in mortality among the other transfused and non-transfused groups (log-rank test P = 0.0001). Effect modification analysis by Cox proportional hazards regression adjusted for age, sex, hemoglobin concentration, blood group type, and eosinophilia showed a significant interaction between platelet count and transfusion status (P = 0.028). Children with thrombocytopenia who were transfused and died had little or no post-transfusion increase in platelets, in contrast to those who survived. Freshness of transfused whole blood, construed from expiration dates, correlated with greater platelet recovery and improved survival. DISCUSSION/SIGNIFICANCE OF IMPACT: The role of platelets in malaria pathophysiology is complex and incompletely understood; prior studies describe preferential binding of platelets to parasitized erythrocytes and direct parasitocidal activity, whereas others detailed deleterious effects in malaria involving the central nervous system vasculature. These findings point to a potential clinical role for platelet-directed transfusion strategies to improve survival in children with severe falciparum malaria, which should be further assessed in randomized interventional studies.
The prognostic significance of an index episode of affective disorder with delusions was assessed in a longitudinal study of a cohort of adolescent psychiatric inpatients (n = 43). Part I of a study has been reported in a previous article. Initial assessmentdata (anamnestic variables, clinical assessment) did not discriminate between onset of affective disorder and schizophrenia. Part II of the study provides a longitudinal perspective of the cohort's diagnostic and life adjustment: diagnoses of schizophrenia increased, schizophreniform disorders disappeared, affective disorders were stable and a schizo-affective category emerged. Patients in the schizophrenic category had severely impaired life adjustment, while the level of functioning in unipolar and bipolar patients was consistently satisfactory. Compared to the initial diagnosis, the cohort showed a tendency to develop into schizophrenia. It is too early to affirm that every adolescent with delusional symptoms at onset will later develop schizophrenia, however, this risk appears real.
Background. Orthotopic heart transplantation (OHT) is a major surgical intervention inducing distress and anxiety. Psychiatric evaluation of organ transplant candidates is now routinely proposed. This study purposed to assess the psychological evolution in patients having received psychological and/or psychiatric assistance before and during 1–6 postoperative months. Methods. Twenty-two consecutive transplant candidates were psychically evaluated as part of the preoperative protocol. In the waiting period, 1 and 6 months after OHT, they were asked to fill out the following questionnaires: the General Health Questionnaire, the Spielberger’s State-Trait Anxiety Inventory, the Beck Depression Inventory, the Perceived Social Support Scale, the Toronto Alexithymia Scale and the Personal Reaction Inventory. Results. A DSM-IV Axis I diagnosis was found in nine patients (41%); four patients (18%) presented with an Axis II diagnosis. One month after OHT, scores of depression, anxiety and general health significantly improved, while scores of social support, alexithymia and social desirability did not differ. In the sixth postoperative month, all psychological scores remained stable. Conclusions. A high prevalence of preoperative psychopathology was reported in 22 candidates who received OHT. Surgical intervention obviously improved the quality of life after cardiac transplantation. If the impact of psychological and/or psychiatric aid remains difficult to appraise, these results emphasize the positive impact of surgery on psychological status and the appropriateness of the psychosomatician’s social support intervention on patients facing the transplant process.
The career choices of medical students change often during the course of their training. Recent changes to the UK medical training structure force graduates to specialise earlier in their careers. This would make medical school placements even more important in speciality choice. In the UK psychiatry is one of the most undersubscribed specialities.
There are many possible reasons. However, there are very few areas where the profession can exert any influence. Currently, the only available option seems to be to compete with other specialities for the limited number of medical graduates available for postgraduate training.
To assess the influence of placement experience at medical school on student speciality preference and hence subsequent career choice.
50 medical students from a UK university were asked to rank 8 medical specialities from 1–8 (1 = most preferred, 8= least preferred) before and after placements in those respective specialities. The average ranks before and after placements were then compared.
The average specialty ranks before and after placements were: Speciality (before: after), Dermatology (6.2:6.1), Otolaryngology (4.7:4.6), Geriatrics (5.0:4.8), General Practice (3.4:3.5), Obstetrics and Gynaecology (2.7:2.8), Ophthalmology (5.9:5.9), Paediatrics (3.3:3.2) and Psychiatry (4.8:5.1).
The results show that whilst placements in Geriatrics, Paediatrics and Otolaryngology led to an increases in preference +0.2, +0.1, +0.1 respectively. Psychiatry placement led to a large decrease in preference of −0.3. Therefore, specialities such as psychiatry that find it hard to attract medical graduates may benefit from focussing on improving medical student teaching and experience.
Gender differences in psychosis have been investigated, and the results have contributed to a better understanding of the disease, but many questions are unanswered. In clinical terms, women and men with psychosis differ in terms of access to social support, tendency of substance abuse, level of functioning and symptom patterns. We aimed to investigate how gender differences at onset of psychosis develop during the first 5 years of treatment.
A total of 578 patients with a first-episode psychosis in the schizophrenia spectrum were included in the Danish OPUS trial – a randomized clinical trial comparing 2 years of intensive early-intervention programme with standard treatment. All patients were assessed with validated instruments at inclusion, and after 2 and 5 years. Data were analysed for significant gender differences.
Males have significantly higher levels of negative symptoms at all times, and are more likely to live alone and suffer from substance abuse. Females reach higher levels of social functioning at follow-up, and show a greater tendency to be employed or in education than males. Markedly more women than men live with children. More women than men reach a state of recovery and are more compliant with medication.
There are significant gender differences at 2- and 5-year follow-up in this large cohort of first-episode psychotic patients. Males and females show different symptomatology and different levels of social functioning.
Early Intervention services with team-based intensive case management and family involvement are superior to standard treatment in reducing psychotic and negative symptoms and comorbid substance abuse and improving social functioning and user satisfaction. The results of the OPUS-trial will be presented together with meta-analyses based on similar trials. The implementation of OPUS all over Denmark will be presented together with the Danish OPUS-fidelity study. Specialized elements are being are being developed such as inclusion of new methods in CBT for psychotic and negative symptoms, neurocognitive and social cognitive training programs, interventions for supported employment and focus on physical health. Results of long term follow-up studies indicate that the prognosis of first episode psychosis is very diverse with the extremes represented by one group being well functioning and able to quit medication without relapse; and another group having a long term chronic course of illness with a need for support to maintain daily activities. The Danish TAILOR-trial–testing dose reduction versus maintenance therapy will be presented. It will be of immense value to be able to intervene in risk groups identified in the premorbid phase, and there are few examples of ongoing trial for children of parent with schizophrenia and bipolar disorder.
Disclosure of interest
The authors have not supplied their declaration of competing interest.
We present a sediment-mixing process model of till genesis based on data from surface tills of the Saginaw lobe terrain in lower Michigan. Our research uses a spatial approach to understanding glacial landsystems and till genesis. We sampled calcareous till at 336 upland sites and at 17 sites in lacustrine sediment of the Saginaw Lake plain. The loamy tills have bimodal grain-size curves, with a fine-texture mode near the silt–clay boundary and a sand mode. Spatial grouping analysis suggests that tills can be divided into six groups, each with different textures and clay mineral compositions that vary systematically down-ice. The similarity among groups with respect to the silt–clay mode and clay mineralogy argues for a common origin for the fines—illite-rich lacustrine sediment of the Saginaw Lake plain. Fine-textured sediments were probably entrained, transported, and deposited down-ice as till, which also becomes sandier and enriched in kaolinite, reflecting increasing mixing with shallow sandstone bedrock with distance from the lacustrine clay source. Clayey tills on the flanks of the Saginaw terrain may reflect proglacial ponding against nearby uplands. A process model of progressive down-ice mixing of preexisting fine lake sediments with crushed/abraded sandstone bedrock helps to better explain till textures compared with a purely crushing/abrasion process model.
The National Institute of Standards and Technology (NIST) certifies a suite of Standard Reference Materials (SRMs) to evaluate specific aspects of instrument performance of both X-ray and neutron powder diffractometers. This report describes SRM 660c, the fourth generation of this powder diffraction SRM, which is used primarily for calibrating powder diffractometers with respect to line position and line shape for the determination of the instrument profile function (IPF). It is certified with respect to lattice parameter and consists of approximately 6 g of lanthanum hexaboride (LaB6) powder. So that this SRM would be applicable for the neutron diffraction community, the powder was prepared from an isotopically enriched 11B precursor material. The microstructure of the LaB6 powder was engineered specifically to yield a crystallite size above that where size broadening is typically observed and to minimize the crystallographic defects that lead to strain broadening. A NIST-built diffractometer, incorporating many advanced design features, was used to certify the lattice parameter of the LaB6 powder. Both Type A, statistical, and Type B, systematic, uncertainties have been assigned to yield a certified value for the lattice parameter at 22.5 °C of a = 0.415 682 6 ± 0.000 008 nm (95% confidence).
We investigate the factors associated with the occurrence and abundance of external and blood parasites in African penguins (Spheniscus demersus), an endangered seabird that breeds exclusively on the coasts of Namibia and South Africa. External parasites were collected using the dust-ruffling method from 171 African Penguins admitted at a rehabilitation facility in the Western Cape, South Africa. Additionally, blood smears were obtained upon admission and weekly during rehabilitation and examined for blood parasites. Fleas Parapsyllus longicornis humboldti, ticks Ornithodoros capensis and lice Austrogoniodes demersus were recovered from 93, 63 and 40%, respectively, of the penguins upon admission to the centre. Rescue location and age group were identified as significant determinants of flea abundance, whereas month of admission was a significant determinant of tick abundance. Blood parasites were also common on admission, with Babesia being the most frequent (46% prevalence) whereas Borrelia was recorded sporadically (1.2%) and Plasmodium was recorded once. The prevalence and abundance of ticks on admission was positively associated with Babesia infection on admission. Our findings demonstrate the variability and contributing factor of parasite infections in an endangered species of penguin, and highlight the need for additional research on the parasite–host dynamics involving these potential disease vectors.