scholarly journals Cretaciella sorianoae gen. et sp. nov. (Coleoptera, Leiodidae, Cholevinae, Oritocatopini), Anophthalmic Species from Albian Amber of the Escucha Formation (Alava, Spain)

Geosciences ◽  
2019 ◽  
Vol 9 (12) ◽  
pp. 521 ◽  
Author(s):  
Michel Perreau
Keyword(s):  
Phase Contrast ◽  
Sub Saharan Africa ◽  
X Ray ◽  
Extant Species ◽  
Internal Structures ◽  
Sub Saharan

Cretaciella sorianoae gen. et sp. nov. (Coleoptera, Leiodidae, Cholevinae, Oritocatopini) from Albian amber of the Escucha Formation (Alava, Spain) is described and illustrated. This is the first species of Leiodidae from Alava amber and the first Cholevinae from Cretaceous amber. External and internal structures are investigated by propagation phase contrast X-ray microtomography. Based on both external and genital structures, Cretaciella is tentatively placed in the tribe Oritocatopini, the extant species of which occur in Sub-Saharan Africa. This specimen has no visible eyes or hind wings, which suggests an adaptation to subterranean or at least to soil litter environments. The biogeography of the tribe is succinctly discussed.

scholarly journals Principles of Different X-ray Phase-Contrast Imaging: A Review

2021 ◽  
Vol 11 (7) ◽  
pp. 2971
Author(s):  
Siwei Tao ◽  
Congxiao He ◽  
Xiang Hao ◽  
Cuifang Kuang ◽  
Xu Liu
Keyword(s):  
Biological Samples ◽  
Phase Contrast ◽  
Recent Progress ◽  
Phase Contrast Imaging ◽  
Contrast Imaging ◽  
X Ray ◽  
X Ray Imaging ◽  
Internal Structures ◽  
X Ray Absorption ◽  
Made In

Numerous advances have been made in X-ray technology in recent years. X-ray imaging plays an important role in the nondestructive exploration of the internal structures of objects. However, the contrast of X-ray absorption images remains low, especially for materials with low atomic numbers, such as biological samples. X-ray phase-contrast images have an intrinsically higher contrast than absorption images. In this review, the principles, milestones, and recent progress of X-ray phase-contrast imaging methods are demonstrated. In addition, prospective applications are presented.

scholarly journals Characteristics and outcomes of admitted patients infected with SARS-CoV-2 in Uganda

2020 ◽  
Vol 7 (1) ◽  
pp. e000646 ◽  
Author(s):  
Bruce Kirenga ◽  
Winters Muttamba ◽  
Alex Kayongo ◽  
Christopher Nsereko ◽  
Trishul Siddharthan ◽  
...  
Keyword(s):  
Statistical Significance ◽  
Sub Saharan Africa ◽  
Detailed Data ◽  
X Ray ◽  
Mild Disease ◽  
Clinical Recovery ◽  
Abnormal Chest ◽  
Chest X Ray ◽  
Sub Saharan ◽  
Muscle Ache

RationaleDetailed data on the characteristics and outcomes of patients with COVID-19 in sub-Saharan Africa are limited.ObjectiveWe determined the clinical characteristics and treatment outcomes of patients diagnosed with COVID-19 in Uganda.MeasurementsAs of the 16 May 2020, a total of 203 cases had been confirmed. We report on the first 56 patients; 29 received hydroxychloroquine (HCQ) and 27 did not. Endpoints included admission to intensive care, mechanical ventilation or death during hospitalisation.Main resultsThe median age was 34.2 years; 67.9% were male; and 14.6% were <18 years. Up 57.1% of the patients were asymptomatic. The most common symptoms were fever (21.4%), cough (19.6%), rhinorrhea (16.1%), headache (12.5%), muscle ache (7.1%) and fatigue (7.1%). Rates of comorbidities were 10.7% (pre-existing hypertension), 10.7% (diabetes) and 7.1% (HIV), Body Mass Index (BMI) of ≥30 36.6%. 37.0% had a blood pressure (BP) of >130/90 mm Hg, and 27.8% had BP of >140/90 mm Hg. Laboratory derangements were leucopenia (10.6%), lymphopenia (11.1%) and thrombocytopenia (26.3%). Abnormal chest X-ray was observed in 14.3%. No patients reached the primary endpoint. Time to clinical recovery was shorter among patients who received HCQ, but this difference did not reach statistical significance.ConclusionMost of the patients with COVID-19 presented with mild disease and exhibited a clinical trajectory not similar to other countries. Outcomes did not differ by HCQ treatment status in line with other concluded studies on the benefit of using HCQ in the treatment of COVID-19.

Phase-contrast X-ray CT image of breast tumor

1998 ◽  
Vol 5 (3) ◽  
pp. 1133-1135 ◽  
Author(s):  
Tohoru Takeda ◽  
Atsushi Momose ◽  
Ei Ueno ◽  
Yuji Itai
Keyword(s):  
Breast Tumor ◽  
Phase Contrast ◽  
Soft Tissues ◽  
Ct Images ◽  
Human Breast ◽  
Human Breast Tumor ◽  
Synchrotron Source ◽  
X Ray ◽  
Optical Images ◽  
Internal Structures

Phase-contrast X-ray CT images generated by differences in refractive indices can be used to visualize the internal structures of soft tissues without contrast enhancement. In this study, imaging of human breast tumor was performed on formalin-fixed samples. Experiments were carried out at the synchrotron source of the Photon Factory, Tsukuba, Japan. The X-ray energy was adjusted to 17.7 keV. Phase-contrast X-ray CT images revealed various structures of human breast tumor as clearly as optical images.

scholarly journals ‘If not TB, what could it be?’ Chest X-ray findings from the 2016 Kenya Tuberculosis Prevalence Survey

Thorax ◽  
2021 ◽  
pp. thoraxjnl-2020-216123
Author(s):  
Brenda Nyambura Mungai ◽  
Elizabeth Joekes ◽  
Enos Masini ◽  
Angela Obasi ◽  
Veronica Manduku ◽  
...  
Keyword(s):  
Population Based ◽  
Sub Saharan Africa ◽  
Radiological Findings ◽  
Prevalence Survey ◽  
X Ray ◽  
Chest X Ray ◽  
Sub Saharan ◽  
Significant Disease ◽  
Tuberculosis Prevalence ◽  
Missed Opportunity

BackgroundThe prevalence of diseases other than TB detected during chest X-ray (CXR) screening is unknown in sub-Saharan Africa. This represents a missed opportunity for identification and treatment of potentially significant disease. Our aim was to describe and quantify non-TB abnormalities identified by TB-focused CXR screening during the 2016 Kenya National TB Prevalence Survey.MethodsWe reviewed a random sample of 1140 adult (≥15 years) CXRs classified as ‘abnormal, suggestive of TB’ or ‘abnormal other’ during field interpretation from the TB prevalence survey. Each image was read (blinded to field classification and study radiologist read) by two expert radiologists, with images classified into one of four major anatomical categories and primary radiological findings. A third reader resolved discrepancies. Prevalence and 95% CIs of abnormalities diagnosis were estimated.FindingsCardiomegaly was the most common non-TB abnormality at 259 out of 1123 (23.1%, 95% CI 20.6% to 25.6%), while cardiomegaly with features of cardiac failure occurred in 17 out of 1123 (1.5%, 95% CI 0.9% to 2.4%). We also identified chronic pulmonary pathology including suspected COPD in 3.2% (95% CI 2.3% to 4.4%) and non-specific patterns in 4.6% (95% CI 3.5% to 6.0%). Prevalence of active-TB and severe post-TB lung changes was 3.6% (95% CI 2.6% to 4.8%) and 1.4% (95% CI 0.8% to 2.3%), respectively.InterpretationBased on radiological findings, we identified a wide variety of non-TB abnormalities during population-based TB screening. TB prevalence surveys and active case finding activities using mass CXR offer an opportunity to integrate disease screening efforts.FundingNational Institute for Health Research (IMPALA-grant reference 16/136/35).

scholarly journals Smallholder Farmers’ Market Participation: Concepts and Methodological Approach from Sub-Saharan Africa

2019 ◽  
Vol 7 (2) ◽  
pp. 139-157 ◽  
Author(s):  
Olutosin A. Otekunrin ◽  
Siaka Momoh ◽  
Idris A. Ayinde
Keyword(s):  
Smallholder Farmers ◽  
Methodological Approach ◽  
Sub Saharan Africa ◽  
Market Participation ◽  
Farmers Market ◽  
X Ray ◽  
Methodological Approaches ◽  
Sub Saharan ◽  
Productive Assets ◽  
Appreciable Reduction

This paper reviews the empirical evidence on smallholder farmers’ market participation focusing on cash/food crops and livestock in Sub-Saharan Africa (SSA) with special attention on the methodological approaches employed in this region in an attempt to x-ray these methods, identifying their advantages and limitations and possible means smallholder farmers would be able to transit from subsistence to commercialised agriculture capable of lifting them out of poverty trap that seems to have engulfed many rural SSA. This paper recommends interventions geared towards improving smallholder farmers’ organisation, producers’ association and ensuring appreciable reduction in transaction costs and also improving farmers’ access to productive assets and improved technologies capable of stimulating profitable smallholders’ market participation.

scholarly journals A parasitic coevolution since the Miocene revealed by phase-contrast synchrotron X-ray microtomography and the study of natural history collections

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Michel Perreau ◽  
Danny Haelewaters ◽  
Paul Tafforeau
Keyword(s):  
Natural History ◽  
Phase Contrast ◽  
Parasitic Fungus ◽  
Technological Advancement ◽  
Fossil Species ◽  
X Ray ◽  
Phylogenetic Relations ◽  
Dominican Amber ◽  
Natural History Collections ◽  
Extant Species

AbstractThe discovery of a new fossil species of the Caribbeo-Mexican genus Proptomaphaginus (Coleoptera, Leiodidae, Cholevinae) from Dominican amber, associated with a new fossil parasitic fungus in the genus Columnomyces (Ascomycota, Laboulbeniales), triggered an investigation of extant species of Proptomaphaginus and revealed the long-enduring parasitic association between these two genera. This effort resulted in the description of the fossil species †Proptomaphaginus alleni sp. nov., and one fossil and two extant species of Columnomyces, selectively associated with species of Proptomaphaginus: †Columnomyces electri sp. nov. associated with the fossil †Proptomaphaginus alleni in Dominican amber, Columnomyces hispaniolensis sp. nov. with the extant Proptomaphaginus hispaniolensis (endemic of Hispaniola), and Columnomyces peckii sp. nov. with the extant Proptomaphaginus puertoricensis (endemic of Puerto Rico). Based on biogeography, our current understanding is that the Caribbean species of Proptomaphaginus and their parasitic species of Columnomyces have coevolved since the Miocene. This is the first occurrence of such a coevolution between a genus of parasitic fungus and a genus of Coleoptera. The phylogenetic relations among Proptomaphaginus species are also addressed based on a parsimony analysis. Fossil specimens were observed by propagation phase-contrast synchrotron X-ray microtomography (PPC-SRμCT) and extant specimens were obtained through the study of preserved dried, pinned insects, attesting for the importance of (i) technological advancement and (ii) natural history collections in the study of microparasitic relationships.

scholarly journals A minute fossil phoretic mite recovered by phase-contrast X-ray computed tomography

2011 ◽  
Vol 8 (3) ◽  
pp. 457-460 ◽  
Author(s):  
Jason A. Dunlop ◽  
Stefan Wirth ◽  
David Penney ◽  
Andrew McNeil ◽  
Robert S. Bradley ◽  
...  
Keyword(s):  
Computed Tomography ◽  
Phase Contrast ◽  
Three Dimensional ◽  
Morphological Characters ◽  
Three Dimensional Model ◽  
X Ray ◽  
Extant Species ◽  
Minimum Age ◽  
X Ray Computed ◽  
Body Fossil

High-resolution phase-contrast X-ray computed tomography (CT) reveals the phoretic deutonymph of a fossil astigmatid mite (Acariformes: Astigmata) attached to a spider's carapace (Araneae: Dysderidae) in Eocene (44–49 Myr ago) Baltic amber. Details of appendages and a sucker plate were resolved, and the resulting three-dimensional model demonstrates the potential of tomography to recover morphological characters of systematic significance from even the tiniest amber inclusions without the need for a synchrotron. Astigmatids have an extremely sparse palaeontological record. We confirm one of the few convincing fossils, potentially the oldest record of Histiostomatidae. At 176 µm long, we believe this to be the smallest arthropod in amber to be CT-scanned as a complete body fossil, extending the boundaries for what can be recovered using this technique. We also demonstrate a minimum age for the evolution of phoretic behaviour among their deutonymphs, an ecological trait used by extant species to disperse into favourable environments. The occurrence of the fossil on a spider is noteworthy, as modern histiostomatids tend to favour other arthropods as carriers.

The external and internal structures of Amphizoa davidi Lucas (Coleoptera, Amphizoidae), using X-ray phase contrast microtomography

Zootaxa ◽  
2015 ◽  
Vol 3963 (3) ◽  
pp. 335 ◽  
Author(s):  
DEE LI ◽  
KAI ZHANG ◽  
XIAOYAN LI ◽  
PEIPING ZHU ◽  
CAIFENG XU ◽  
...  
Keyword(s):  
Phase Contrast ◽  
X Ray ◽  
Internal Structures

Mid-Pleistocene Change in Large Mammal Faunas of East Africa

1995 ◽  
Vol 43 (1) ◽  
pp. 106-113 ◽  
Author(s):  
Richard Potts ◽  
Alan Deino
Keyword(s):  
East Africa ◽  
Late Quaternary ◽  
Sub Saharan Africa ◽  
Middle Pleistocene ◽  
Large Mammal ◽  
Geographic Ranges ◽  
Extant Species ◽  
Sub Saharan ◽  
Mammal Faunas ◽  
Age Estimates

AbstractSingle-crystal 40Ar/39Ar age estimates of 392,000 ± 4000 to 330,000 ± 6000 yr from Lainyamok, a middle Pleistocene fossil locality in the southern Kenya rift, document the oldest evidence from sub-Saharan Africa of a diverse, large mammal fauna consisting entirely of extant species. The inferred age of this fauna implies an upper limit for extinction of species that characterize well-calibrated, mid-Pleistocene fossil assemblages in East Africa. For its age and species richness, the Lainyamok fauna is surprising for its lack of extinct forms (e.g., the bovine Pelorovis) well documented in later faunal assemblages of East and South Africa. Definitive presence of the South African blesbok (Damaliscus dorcas) is also unexpected, especially as this alcelaphine bovid is the dominant large mammal in the Lainyamok fauna. These age estimates and the faunal composition at Lainyamok indicate that geographic ranges and taxonomic associations of extant largebodied mammals were susceptible to wide fluctuations in sub-Saharan Africa over the past 330,000 yr. This inference is consistent with the hypothesis of nonanalogue, or ephemeral, biotas believed to characterize late Quaternary ecosystems of northern continents.

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