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1.
Environ Entomol ; 53(2): 249-258, 2024 Apr 11.
Article in English | MEDLINE | ID: mdl-38309712

ABSTRACT

Knowledge of insect pest ecology and biology is important for maximizing crop protection and reducing crop losses. Currently, we lack an efficient control program for the cocoa mirid Sahlbergella singularis Haglund (Hemiptera: Miridae), the principal insect pest of cocoa in West and Central Africa. A 2-yr study was conducted in 11 plantations across Ayos and Konye, two of the largest cocoa growing areas of Cameroon. We evaluated the effects of mirid sex pheromone and climatic variations on mirid population dynamics and their associated cocoa damage. Sex pheromone traps caught 1.5-fold higher mirids in Ayos than in Konye, with more overall counts in 2015 than in 2016. Cocoa pod counts were also significantly higher in 2015 than in 2016 and were negatively correlated with temperature and relative humidity. In both localities, mirid populations and associated cocoa pod damage were suppressed in plantations where sex pheromone traps were used. Damage incidence was positively correlated with mirid counts, confirming that the cocoa pod is the preferential site for mirid feeding and reproduction. As such, damage incidence could be used as proxy for comparative mirid population level due to the mirid's cryptic habit. Of the recorded weather variables, only relative humidity was correlated (negatively) with damage severity. Our data on the relationships between damage caused by mirids and their population dynamics and sex pheromone trap catches suggest that an effective control strategy using mass trapping could be developed for mirid management in cocoa plantations.


Subject(s)
Cacao , Hemiptera , Heteroptera , Sex Attractants , Animals , Pheromones , Cameroon , Insect Control
2.
Trop Med Infect Dis ; 7(7)2022 Jul 18.
Article in English | MEDLINE | ID: mdl-35878149

ABSTRACT

(1) Background: Malaria heavily affects the Democratic Republic of the Congo (DRC) despite the use of effective drugs. Poor adherence to malaria treatment may contribute to this problem. (2) Methods: In one rural and one urban health area in each of the 11 former provinces of the DRC, all households with a case of malaria in the 15 days preceding the survey were selected and the patients or caregivers were interviewed. Adherence to malaria treatment was assessed by self-declaration about its completion. Logistic regression was used to assess predictors. (3) Results: 1732 households participated. Quinine was the most used drug; adherence to artesunate-amodiaquine was the lowest and the main reason for treatment discontinuation was adverse reactions. Predictors of adherence were residence in an urban area, university education, catholic religion, and adoption of recommended behaviour towards a malaria case. Adherence was significantly lower for responders who obtained information on antimalarials from Community Health Workers (CHW). (4) Conclusions: Usage of recommended drugs and adherence to malaria treatment need to be promoted, especially in rural areas, and CHW involvement needs to be improved. Awareness messages need to be made accessible and comprehensible to poorly educated populations and churches need to be involved.

3.
Microorganisms ; 8(10)2020 Oct 16.
Article in English | MEDLINE | ID: mdl-33081237

ABSTRACT

The haloarchaeon Halorubrum lacusprofundi is among the few polyextremophilic organisms capable of surviving in one of the most extreme aquatic environments on Earth, the Deep Lake of Antarctica (-18 °C to +11.5 °C and 21-28%, w/v salt content). Hence, H. lacusprofundi has been proposed as a model for biotechnology and astrobiology to investigate potential life beyond Earth. To understand the mechanisms that allow proteins to adapt to both salinity and cold, we structurally (including X-ray crystallography and molecular dynamics simulations) and functionally characterized the ß-galactosidase from H. lacusprofundi (hla_bga). Recombinant hla_bga (produced in Haloferax volcanii) revealed exceptional stability, tolerating up to 4 M NaCl and up to 20% (v/v) of organic solvents. Despite being cold-adapted, hla_bga was also stable up to 60 °C. Structural analysis showed that hla_bga combined increased surface acidity (associated with halophily) with increased structural flexibility, fine-tuned on a residue level, for sustaining activity at low temperatures. The resulting blend enhanced structural flexibility at low temperatures but also limited protein movements at higher temperatures relative to mesophilic homologs. Collectively, these observations help in understanding the molecular basis of a dual psychrophilic and halophilic adaptation and suggest that such enzymes may be intrinsically stable and functional over an exceptionally large temperature range.

4.
Zookeys ; 928: 1-216, 2020.
Article in English | MEDLINE | ID: mdl-32362741

ABSTRACT

The geological and paleoenvironmental setting and the vertebrate taxonomy of the fossiliferous, Cenomanian-age deltaic sediments in eastern Morocco, generally referred to as the "Kem Kem beds", are reviewed. These strata are recognized here as the Kem Kem Group, which is composed of the lower Gara Sbaa and upper Douira formations. Both formations have yielded a similar fossil vertebrate assemblage of predominantly isolated elements pertaining to cartilaginous and bony fishes, turtles, crocodyliforms, pterosaurs, and dinosaurs, as well as invertebrate, plant, and trace fossils. These fossils, now in collections around the world, are reviewed and tabulated. The Kem Kem vertebrate fauna is biased toward large-bodied carnivores including at least four large-bodied non-avian theropods (an abelisaurid, Spinosaurus, Carcharodontosaurus, and Deltadromeus), several large-bodied pterosaurs, and several large crocodyliforms. No comparable modern terrestrial ecosystem exists with similar bias toward large-bodied carnivores. The Kem Kem vertebrate assemblage, currently the best documented association just prior to the onset of the Cenomanian-Turonian marine transgression, captures the taxonomic diversity of a widespread northern African fauna better than any other contemporary assemblage from elsewhere in Africa.

5.
Sci Rep ; 8(1): 8509, 2018 05 31.
Article in English | MEDLINE | ID: mdl-29855529

ABSTRACT

Acanthomorph teleosts (spiny-rayed fishes) account for approximately a third of extant vertebrate species. They appeared during the Late Cretaceous and have been a major component of aquatic biodiversity since the early Cenozoic. They occupy today most trophic levels and ecological niches in aquatic environments, however very little is known about those that were adopted by the earliest representatives of the group. Here, we report on an exceptional glimpse into the ecological diversity of early spiny-rayed fishes provided by the unusual preservation of a newly discovered specimen of the freshwater acanthomorph Spinocaudichthys from the Upper Cretaceous of Morocco. A combination of major-to-trace elemental mapping methods reveals that the gross morphology of the specimen's intestine has been remarkably preserved owing to the rapid mineralization of iron hydroxides around it. Differing with the typically short and straight intestinal tract of carnivorous teleosts, the intestine in Spinocaudichthys is long and highly convoluted, indicating a probable herbivorous diet. Acanthomorphs would therefore have conquered various ecological niches in their early evolutionary history, prior to their subsequent phylogenetic diversification in both marine and freshwater environments that followed the K-Pg extinction event.


Subject(s)
Fishes/anatomy & histology , Fossils/anatomy & histology , Intestines/anatomy & histology , Animals , Biodiversity , Biological Evolution , Ecosystem , Extinction, Biological , Fishes/classification , Intestines/chemistry , Morocco , Paleontology , Phylogeny
6.
Malar J ; 17(1): 189, 2018 May 03.
Article in English | MEDLINE | ID: mdl-29724210

ABSTRACT

BACKGROUND: Malaria the first causes of death from parasitic infection worldwide. Interventions to reduce the burden of malaria have produced a tremendous drop in malaria morbidity and mortality. However, progress is slower in DRC, which shares with Nigeria 39% of deaths related to malaria globally. Inappropriate use of drugs may be one of the factors of this below-average performance. The aim of this study was to describe the use of drugs in the management of uncomplicated malaria in public health facilities in DRC. METHODS: A drug use study was carried out in DRC from January to March 2014. In each of the former 11 provinces of DRC, one Rural Health Centre, one Urban Health Centre and one General Hospital were selected. In each of them, 100 patient's files containing prescription of anti-malarials from January to December 2013 were randomly selected. Among them, all of the files with diagnosis of uncomplicated malaria were included in this study. Prescribed anti-malarials, co-prescribed drugs and their indications were collected. Descriptive analyses were performed. RESULTS: A total of 2300 files out of 3300 (69.7%) concerned uncomplicated malaria and were included in analysis. Malaria treatment was initiated after a positive RDT or microscopy in 51.5% of cases, upon suspicion without requesting biological confirmation in 37% and despite negative results in 11%. Twenty-nine (29) different treatment regimens were used. The drugs recommended by the National Malaria Control Programme were used in 54.3% of cases (artesunate-amodiaquine 37.4% or artemether-lumefantrine 16.9%). The second most used anti-malarial was quinine (32.4%). Apart from anti-malarials, an average of 3.1 drugs per patient were prescribed, among which antibiotics (67.9%), analgesics and non-steroidal anti-inflammatory (NSAIDs) (all abbreviations to be explicated on first use) (70.6%), vitamins (29.1%), anaemia drugs, including blood transfusion (9.1%) and corticosteroids (5.7%), In 51.4% of cases there was no indication for the concomitant medication. CONCLUSION: Management of uncomplicated malaria in DRC is characterized by a low adherence to treatment policy, numerous treatment regimens, and abundant concomitant medication potentially harmful to the patient. This may contribute to the low performance of DRC in malaria control. Determinant of this irrational use of drugs need to be assessed in order to formulate and implement efficient corrective measures.


Subject(s)
Antimalarials/therapeutic use , Health Facilities , Malaria/drug therapy , Rural Health Services , Adolescent , Adult , Aged , Child , Child, Preschool , Democratic Republic of the Congo , Health Facilities/statistics & numerical data , Humans , Infant , Infant, Newborn , Malaria/prevention & control , Middle Aged , Rural Health Services/statistics & numerical data , Young Adult
7.
Emotion ; 14(4): 733-47, 2014 Aug.
Article in English | MEDLINE | ID: mdl-24866530

ABSTRACT

Nostalgia is a frequently experienced complex emotion, understood by laypersons in the United Kingdom and United States of America to (a) refer prototypically to fond, self-relevant, social memories and (b) be more pleasant (e.g., happy, warm) than unpleasant (e.g., sad, regretful). This research examined whether people across cultures conceive of nostalgia in the same way. Students in 18 countries across 5 continents (N = 1,704) rated the prototypicality of 35 features of nostalgia. The samples showed high levels of agreement on the rank-order of features. In all countries, participants rated previously identified central (vs. peripheral) features as more prototypical of nostalgia, and showed greater interindividual agreement regarding central (vs. peripheral) features. Cluster analyses revealed subtle variation among groups of countries with respect to the strength of these pancultural patterns. All except African countries manifested the same factor structure of nostalgia features. Additional exemplars generated by participants in an open-ended format did not entail elaboration of the existing set of 35 features. Findings identified key points of cross-cultural agreement regarding conceptions of nostalgia, supporting the notion that nostalgia is a pancultural emotion.


Subject(s)
Cross-Cultural Comparison , Cultural Characteristics , Emotions , Memory , Adult , Cluster Analysis , Female , Humans , Male , Students/psychology , Students/statistics & numerical data , United Kingdom , United States , Young Adult
8.
PLoS One ; 9(6): e90751, 2014.
Article in English | MEDLINE | ID: mdl-24603467

ABSTRACT

We describe an extensive ichnofossil assemblage from the likely Cenomanian-age 'lower' and 'upper' units of the 'Kem Kem beds' in southeastern Morocco. In the lower unit, trace fossils include narrow vertical burrows in cross-bedded sandstones and borings in dinosaur bone, with the latter identified as the insect ichnotaxon Cubiculum ornatus. In the upper unit, several horizons preserve abundant footprints from theropod dinosaurs. Sauropod and ornithischian footprints are much rarer, similar to the record for fossil bone and teeth in the Kem Kem assemblage. The upper unit also preserves a variety of invertebrate traces including Conichnus (the resting trace of a sea-anemone), Scolicia (a gastropod trace), Beaconites (a probable annelid burrow), and subvertical burrows likely created by crabs for residence and detrital feeding on a tidal flat. The ichnofossil assemblage from the Upper Cretaceous Kem Kem beds contributes evidence for a transition from predominantly terrestrial to marine deposition. Body fossil and ichnofossil records together provide a detailed view of faunal diversity and local conditions within a fluvial and deltaic depositional setting on the northwestern coast of Africa toward the end of the Cretaceous.


Subject(s)
Dinosaurs/anatomy & histology , Fossils , Animals , Biodiversity , Ecosystem , Foot/anatomy & histology , Morocco
9.
PLoS One ; 9(1): e86946, 2014.
Article in English | MEDLINE | ID: mdl-24489809

ABSTRACT

The interpretation of flattened fossils remains a major challenge due to compression of their complex anatomies during fossilization, making critical anatomical features invisible or hardly discernible. Key features are often hidden under greatly preserved decay prone tissues, or an unpreparable sedimentary matrix. A method offering access to such anatomical features is of paramount interest to resolve taxonomic affinities and to study fossils after a least possible invasive preparation. Unfortunately, the widely-used X-ray micro-computed tomography, for visualizing hidden or internal structures of a broad range of fossils, is generally inapplicable to flattened specimens, due to the very high differential absorbance in distinct directions. Here we show that synchrotron X-ray fluorescence spectral raster-scanning coupled to spectral decomposition or a much faster Kullback-Leibler divergence based statistical analysis provides microscale visualization of tissues. We imaged exceptionally well-preserved fossils from the Late Cretaceous without needing any prior delicate preparation. The contrasting elemental distributions greatly improved the discrimination of skeletal elements material from both the sedimentary matrix and fossilized soft tissues. Aside content in alkaline earth elements and phosphorus, a critical parameter for tissue discrimination is the distinct amounts of rare earth elements. Local quantification of rare earths may open new avenues for fossil description but also in paleoenvironmental and taphonomical studies.


Subject(s)
Fishes/anatomy & histology , Fossils , Metals, Rare Earth/chemistry , Penaeidae/anatomy & histology , Spectrometry, X-Ray Emission/methods , Animals , Paleontology , Spectrometry, X-Ray Emission/instrumentation , Synchrotrons
10.
J Clin Densitom ; 17(1): 150-5, 2014.
Article in English | MEDLINE | ID: mdl-23916756

ABSTRACT

The fracture risk assessment tool (FRAX(®)) has been developed for the identification of individuals with high risk of fracture in whom treatment to prevent fractures would be appropriate. FRAX models are not yet available for all countries or ethnicities, but surrogate models can be used within regions with similar fracture risk. The International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundation (IOF) are nonprofit multidisciplinary international professional organizations. Their visions are to advance the awareness, education, prevention, and treatment of osteoporosis. In November 2010, the IOF/ISCD FRAX initiative was held in Bucharest, bringing together international experts to review and create evidence-based official positions guiding clinicians for the practical use of FRAX. A consensus meeting of the Asia-Pacific (AP) Panel of the ISCD recently reviewed the most current Official Positions of the Joint Official Positions of ISCD and IOF on FRAX in view of the different population characteristics and health standards in the AP regions. The reviewed position statements included not only the key spectrum of positions but also unique concerns in AP regions.


Subject(s)
Asian People , Native Hawaiian or Other Pacific Islander , Osteoporotic Fractures/diagnosis , Osteoporotic Fractures/epidemiology , Absorptiometry, Photon , Algorithms , Asia , Bone Density , Health Status Indicators , Humans , Oceania , Risk Assessment , Risk Factors
11.
J Clin Densitom ; 14(3): 171-80, 2011.
Article in English | MEDLINE | ID: mdl-21810521

ABSTRACT

The International Society for Clinical Densitometry (ISCD) and the International Osteoporosis Foundation (IOF) convened the FRAX(®) Position Development Conference (PDC) in Bucharest, Romania, on November 14, 2010, following a two-day joint meeting of the ISCD and IOF on the "Interpretation and Use of FRAX(®) in Clinical Practice." These three days of critical discussion and debate, led by a panel of international experts from the ISCD, IOF and dedicated task forces, have clarified a number of important issues pertaining to the interpretation and implementation of FRAX(®) in clinical practice. The Official Positions resulting from the PDC are intended to enhance the quality and clinical utility of fracture risk assessment worldwide. Since the field of skeletal assessment is still evolving rapidly, some clinically important issues addressed at the PDCs are not associated with robust medical evidence. Accordingly, some Official Positions are based largely on expert opinion. Despite limitations inherent in such a process, the ISCD and IOF believe it is important to provide clinicians and technologists with the best distillation of current knowledge in the discipline of bone densitometry and provide an important focus for the scientific community to consider. This report describes the methodology and results of the ISCD-IOF PDC dedicated to FRAX(®).


Subject(s)
Absorptiometry, Photon , Diagnosis, Computer-Assisted , Fractures, Bone/diagnosis , Osteoporosis/diagnosis , Osteoporotic Fractures/diagnosis , Femur Neck/diagnostic imaging , Hip Fractures/diagnosis , Humans , Models, Statistical , Risk Assessment , Risk Factors , Societies, Medical
12.
J Clin Densitom ; 14(3): 212-9, 2011.
Article in English | MEDLINE | ID: mdl-21810527

ABSTRACT

Given the significant impact the use of glucocorticoids can have on fracture risk independent of bone density, their use has been incorporated as one of the clinical risk factors for calculating the 10-year fracture risk in the World Health Organization's Fracture Risk Assessment Tool (FRAX(®)). Like the other clinical risk factors, the use of glucocorticoids is included as a dichotomous variable with use of steroids defined as past or present exposure of 3 months or more of use of a daily dose of 5 mg or more of prednisolone or equivalent. The purpose of this report is to give clinicians guidance on adjustments which should be made to the 10-year risk based on the dose, duration of use and mode of delivery of glucocorticoids preparations. A subcommittee of the International Society for Clinical Densitometry and International Osteoporosis Foundation joint Position Development Conference presented its findings to an expert panel and the following recommendations were selected. 1) There is a dose relationship between glucocorticoid use of greater than 3 months and fracture risk. The average dose exposure captured within FRAX(®) is likely to be a prednisone dose of 2.5-7.5 mg/day or its equivalent. Fracture probability is under-estimated when prednisone dose is greater than 7.5 mg/day and is over-estimated when the prednisone dose is less than 2.5 mg/day. 2) Frequent intermittent use of higher doses of glucocorticoids increases fracture risk. Because of the variability in dose and dosing schedule, quantification of this risk is not possible. 3) High dose inhaled glucocorticoids may be a risk factor for fracture. FRAX(®) may underestimate fracture probability in users of high dose inhaled glucocorticoids. 4) Appropriate glucocorticoid replacement in individuals with adrenal insufficiency has not been found to increase fracture risk. In such patients, use of glucocorticoids should not be included in FRAX(®) calculations.


Subject(s)
Diagnosis, Computer-Assisted , Fractures, Bone/chemically induced , Glucocorticoids/adverse effects , Administration, Oral , Algorithms , Glucocorticoids/administration & dosage , Humans , Models, Statistical , Osteoporosis/chemically induced , Osteoporotic Fractures/chemically induced , Prednisolone/adverse effects , Risk Assessment , Risk Factors
13.
J Clin Densitom ; 14(3): 226-36, 2011.
Article in English | MEDLINE | ID: mdl-21810530

ABSTRACT

Tools to predict fracture risk are useful for selecting patients for pharmacological therapy in order to reduce fracture risk and redirect limited healthcare resources to those who are most likely to benefit. FRAX® is a World Health Organization fracture risk assessment algorithm for estimating the 10-year probability of hip fracture and major osteoporotic fracture. Effective application of FRAX® in clinical practice requires a thorough understanding of its limitations as well as its utility. For some patients, FRAX® may underestimate or overestimate fracture risk. In order to address some of the common issues encountered with the use of FRAX® for individual patients, the International Society for Clinical Densitometry (ISCD) and International Osteoporosis Foundation (IOF) assigned task forces to review the medical evidence and make recommendations for optimal use of FRAX® in clinical practice. Among the issues addressed were the use of bone mineral density (BMD) measurements at skeletal sites other than the femoral neck, the use of technologies other than dual-energy X-ray absorptiometry, the use of FRAX® without BMD input, the use of FRAX® to monitor treatment, and the addition of the rate of bone loss as a clinical risk factor for FRAX®. The evidence and recommendations were presented to a panel of experts at the Joint ISCD-IOF FRAX® Position Development Conference, resulting in the development of Joint ISCD-IOF Official Positions addressing FRAX®-related issues.


Subject(s)
Absorptiometry, Photon , Bone Density , Diagnosis, Computer-Assisted , Fractures, Bone/diagnosis , Femur Neck/diagnostic imaging , Femur Neck/pathology , Humans , Lumbar Vertebrae/pathology , Radius/pathology , Risk Assessment
14.
Antonie Van Leeuwenhoek ; 98(3): 263-78, 2010 Oct.
Article in English | MEDLINE | ID: mdl-20559872

ABSTRACT

Native Terminalia spp. in West Africa provide a popular source of construction timber as well as medical, spiritual and social benefits to rural populations. Very little is, however, known regarding the diseases that affect these trees. During an investigation into possible diseases of Terminalia spp. in Cameroon, orange to yellow fungal fruiting structures, resembling those of fungi in the Cryphonectriaceae, were commonly observed on the bark of native Terminalia ivorensis, and on dead branches of non-native Terminalia mantaly. In this study the fungus was identified based on morphological features as well as DNA sequence data (ITS and beta-tubulin) and its pathogenicity was tested on T. mantaly seedlings. Our results showed that isolates of this fungus represent a previously undescribed genus in the Cryphonectriaceae, which we describe as Aurifilum marmelostoma gen. et sp. nov. Pathogenicity tests revealed that A. marmelostoma is pathogenic on T. mantaly. These tests, and the association of A. marmelostoma with disease symptoms on T. ivorensis, suggest that the fungus is a pathogen of this important tree.


Subject(s)
Fungi/classification , Fungi/isolation & purification , Plant Diseases/microbiology , Terminalia/microbiology , Agriculture , Ascomycota , Base Sequence , Cameroon , DNA, Fungal/analysis , DNA, Fungal/isolation & purification , Fungi/genetics , Fungi/pathogenicity , Genes, Fungal , Mycological Typing Techniques , Phylogeny , Plant Bark/microbiology , Polymerase Chain Reaction , Seedlings/microbiology , Sequence Analysis, DNA , Species Specificity , Trees/microbiology , Tubulin/genetics , Virulence
15.
Pediatr Nephrol ; 25(1): 37-47, 2010 Jan.
Article in English | MEDLINE | ID: mdl-19603190

ABSTRACT

Dual-energy X-ray absorptiometry (DXA) is the most widely used technical instrument for evaluating bone mineral content (BMC) and density (BMD) in patients of all ages. However, its use in pediatric patients, during growth and development, poses a much more complex problem in terms of both the technical aspects and the interpretation of the results. For the adults population, there is a well-defined term of reference: the peak value of BMD attained by young healthy subjects at the end of skeletal growth. During childhood and adolescence, the comparison can be made only with healthy subjects of the same age, sex and ethnicity, but the situation is compounded by the wide individual variation in the process of skeletal growth (pubertal development, hormone action, body size and bone size). The International Society for Clinical Densitometry (ISCD) organized a Pediatric Position Development Conference to discuss the specific problems of bone densitometry in growing subjects (9-19 years of age) and to provide essential recommendations for its clinical use.


Subject(s)
Absorptiometry, Photon/methods , Bone Density/physiology , Bone Diseases, Metabolic/diagnosis , Bone and Bones/diagnostic imaging , Adolescent , Bone Diseases, Metabolic/complications , Bone and Bones/metabolism , Canada , Child , Female , Fractures, Spontaneous/etiology , Fractures, Spontaneous/prevention & control , Humans , Male , Practice Guidelines as Topic , Predictive Value of Tests , Societies, Medical , Young Adult
16.
Bone ; 43(6): 1115-21, 2008 Dec.
Article in English | MEDLINE | ID: mdl-18793764

ABSTRACT

The International Society for Clinical Densitometry (ISCD) periodically convenes Position Development Conferences (PDCs) in order to establish standards and guidelines for the assessment of skeletal health. The most recent Adult PDC was held July 20-22, 2007, in Lansdowne, Virginia, USA; the first Pediatric PDC was June 20-21, 2007 in Montreal, Quebec, Canada. PDC topics were selected according to clinical relevancy, perceived need for standardization, and likelihood of achieving agreement. Each topic area was assigned to a task force for a comprehensive review of the scientific literature. The findings of the review and recommendations were presented to adult and pediatric international panels of experts. The panels voted on the appropriateness, necessity, quality of the evidence, strength, and applicability (worldwide or variable according to local requirements) of each recommendation. Those recommendations that were approved by the ISCD Board of Directors become Official Positions. This is a review of the methodology of the PDCs and selected ISCD Official Positions.


Subject(s)
Bone Density , Guidelines as Topic , Adult , Child , Humans
17.
PLoS One ; 3(8): e2995, 2008 Aug 14.
Article in English | MEDLINE | ID: mdl-18701936

ABSTRACT

BACKGROUND: Approximately two hundred human burials were discovered on the edge of a paleolake in Niger that provide a uniquely preserved record of human occupation in the Sahara during the Holocene ( approximately 8000 B.C.E. to the present). Called Gobero, this suite of closely spaced sites chronicles the rapid pace of biosocial change in the southern Sahara in response to severe climatic fluctuation. METHODOLOGY/PRINCIPAL FINDINGS: Two main occupational phases are identified that correspond with humid intervals in the early and mid-Holocene, based on 78 direct AMS radiocarbon dates on human remains, fauna and artifacts, as well as 9 OSL dates on paleodune sand. The older occupants have craniofacial dimensions that demonstrate similarities with mid-Holocene occupants of the southern Sahara and Late Pleistocene to early Holocene inhabitants of the Maghreb. Their hyperflexed burials compose the earliest cemetery in the Sahara dating to approximately 7500 B.C.E. These early occupants abandon the area under arid conditions and, when humid conditions return approximately 4600 B.C.E., are replaced by a more gracile people with elaborated grave goods including animal bone and ivory ornaments. CONCLUSIONS/SIGNIFICANCE: The principal significance of Gobero lies in its extraordinary human, faunal, and archaeological record, from which we conclude the following: The early Holocene occupants at Gobero (7700-6200 B.C.E.) were largely sedentary hunter-fisher-gatherers with lakeside funerary sites that include the earliest recorded cemetery in the Sahara.Principal components analysis of craniometric variables closely allies the early Holocene occupants at Gobero with a skeletally robust, trans-Saharan assemblage of Late Pleistocene to mid-Holocene human populations from the Maghreb and southern Sahara.Gobero was abandoned during a period of severe aridification possibly as long as one millennium (6200-5200 B.C.E).More gracile humans arrived in the mid-Holocene (5200-2500 B.C.E.) employing a diversified subsistence economy based on clams, fish, and savanna vertebrates as well as some cattle husbandry.Population replacement after a harsh arid hiatus is the most likely explanation for the occupational sequence at Gobero.We are just beginning to understand the anatomical and cultural diversity that existed within the Sahara during the Holocene.


Subject(s)
Cemeteries/history , Africa, Northern , Archaeology , Ecosystem , Environment , Fossils , Fresh Water , Funeral Rites , History, Ancient , Humans
18.
South Med J ; 101(7): 740-3, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18580718

ABSTRACT

The International Society for Clinical Densitometry periodically holds Position Development Conferences (PDCs) for the purpose of establishing standards and guidelines for the assessment of skeletal health, including nomenclature, indications, acquisition, analysis, quality control, interpretation, and reporting of bone density tests. Topics are selected for consideration according to criteria that include clinical relevancy, uncertainty in the application of medical evidence to clinical practice, and the likelihood of the expert panel to reach a consensus agreement. The first Pediatric PDC was June 20 to 21, 2007 in Montreal, Quebec, Canada. Topics included fracture prediction and definition of osteoporosis in children; dual-energy x-ray absorptiometry (DXA) assessment in children with chronic disease that may affect the skeleton; DXA interpretation and reporting in children and adolescents; and the use of peripheral quantitative computed tomography in children and adolescents. This report describes the methodology and presents the results of this recent PDC.


Subject(s)
Absorptiometry, Photon/standards , Bone Density , Osteoporosis/diagnosis , Adolescent , Bone Development , Child , Child, Preschool , Female , Humans , Male , Sex Factors , Tomography, X-Ray Computed/standards , Young Adult
19.
South Med J ; 101(7): 735-9, 2008 Jul.
Article in English | MEDLINE | ID: mdl-18580720

ABSTRACT

The International Society for Clinical Densitometry (ISCD) periodically holds Position Development Conferences (PDCs) for the purpose of establishing standards and guidelines for the assessment of skeletal health -- the nomenclature, indications, acquisition, analysis, quality control, interpretation, and reporting of bone density tests. Topics are selected for consideration according to criteria that include clinical relevancy, uncertainty in the application of medical evidence to clinical practice, and the likelihood of the expert panel achieving agreement. The most recent Adult PDC was held July 20 to 22, 2007, in Lansdowne, Virginia. Topics included technical and clinical issues relevant to dual-energy x-ray absorptiometry (DXA), vertebral fracture assessment, and bone densitometry technologies other than central DXA. This report describes the methodology and presents the results of this PDC. The first ISCD Pediatric PDC was held June 20 to 21, 2007 in Montreal, Quebec, Canada, and is reported separately.


Subject(s)
Absorptiometry, Photon/standards , Bone Density , Osteoporosis/diagnosis , Spinal Fractures/diagnosis , Adult , Age Factors , Aged , Female , Humans , Male , Middle Aged , Tomography, X-Ray Computed/standards , Ultrasonography/standards
20.
J Clin Densitom ; 11(1): 6-21, 2008.
Article in English | MEDLINE | ID: mdl-18442749

ABSTRACT

The International Society for Clinical Densitometry (ISCD) convenes a Position Development Conference (PDC) every 2 yr to make recommendations for standards in the field of bone densitometry. The recommendations are based on clinically relevant issues in bone densitometry such as quality control, acquisition, analysis, interpretation, and reporting. In 2007, ISCD convened its first Pediatric Position Development Conference to address issues specific to the assessment of skeletal health in children and adolescents. Topics for consideration are developed by the ISCD Board of Directors and its Scientific Advisory Committee. Clinically relevant questions related to each topic area are assigned to task forces for a comprehensive review of the medical literature and subsequent presentation of the reports to an international panel of experts. For this PDC, the Expert Panel included representatives of the American Society for Bone and Mineral Research and International Bone and Mineral Society. The recommendations of the PDC Expert Panel are then reviewed by the ISCD Board of Directors. Recommendations that are approved become Official Positions of the ISCD. The Pediatric PDC was held June 20-21, 2007, in Montreal, Quebec, Canada. Topics considered were restricted to children and adolescents, and included DXA prediction of fracture and definition of osteoporosis; DXA assessment in diseases that may affect the skeleton; DXA interpretation and reporting; and peripheral quantitative computed tomography measurement. This report describes the methodology and results of the 2007 Pediatric PDC, and a summary of all ISCD Official Positions, including the ones recently adopted by this 2007 Pediatric PDC and the 2007 Lansdowne, Virginia, USA Adult PDC.


Subject(s)
Absorptiometry, Photon/standards , Adult , Child , Humans , Pediatrics/standards , Societies, Medical
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