Entwined African and Asian genetic roots of medieval peoples of the Swahili coast.

The urban peoples of the Swahili coast traded across eastern Africa and the Indian Ocean and were among the first practitioners of Islam among sub-Saharan people1,2. The extent to which these early interactions between Africans and non-Africans were accompanied by genetic exchange remains unknown. Here we report ancient DNA data for 80 individuals from 6 medieval and early modern (AD 1250-1800) coastal towns and an inland town after AD 1650. More than half of the DNA of many of the individuals from coastal towns originates from primarily female ancestors from Africa, with a large proportion-and occasionally more than half-of the DNA coming from Asian ancestors. The Asian ancestry includes components associated with Persia and India, with 80-90% of the Asian DNA originating from Persian men. Peoples of African and Asian origins began to mix by about AD 1000, coinciding with the large-scale adoption of Islam. Before about AD 1500, the Southwest Asian ancestry was mainly Persian-related, consistent with the narrative of the Kilwa Chronicle, the oldest history told by people of the Swahili coast3. After this time, the sources of DNA became increasingly Arabian, consistent with evidence of growing interactions with southern Arabia4. Subsequent interactions with Asian and African people further changed the ancestry of present-day people of the Swahili coast in relation to the medieval individuals whose DNA we sequenced.

Precise timing of abrupt increase in dust activity in the Middle East coincident with 4.2 ka social change.

The extent to which climate change causes significant societal disruption remains controversial. An important example is the decline of the Akkadian Empire in northern Mesopotamia ∼4.2 ka, for which the existence of a coincident climate event is still uncertain. Here we present an Iranian stalagmite record spanning 5.2 ka to 3.7 ka, dated with 25 U/Th ages that provide an average age uncertainty of 31 y (1σ). We find two periods of increased Mg/Ca, beginning abruptly at 4.51 and 4.26 ka, and lasting 110 and 290 y, respectively. Each of these periods coincides with slower vertical stalagmite growth and a gradual increase in stable oxygen isotope ratios. The periods of high Mg/Ca are explained by periods of increased dust flux sourced from the Mesopotamia region, and the abrupt onset of this dustiness indicates threshold behavior in response to aridity. This interpretation is consistent with existing marine and terrestrial records from the broad region, which also suggest that the later, longer event beginning at 4.26 ka is of greater regional extent and/or amplitude. The chronological precision and high resolution of our record indicates that there is no significant difference, at decadal level, between the start date of the second, larger dust event and the timing of North Mesopotamia settlement abandonment, and furthermore reveals striking similarity between the total duration of the second dust event and settlement abandonment. The Iranian record demonstrates this region's threshold behavior in dust production, and its ability to maintain this climate state for multiple centuries naturally.

Mitochondrial variation among the Aymara and the signatures of population expansion in the central Andes.

OBJECTIVES: The exploitation of marine resources and intensive agriculture led to a marked population increase early in central Andean prehistory. Constant historic and prehistoric population movements also characterize this region. These features undoubtedly affected regional genetic variation, but the exact nature of these effects remains uncertain. METHODS: Mitochondrial DNA (mtDNA) hypervariable region I sequence variation in 61 Aymara individuals from La Paz, Bolivia, was analyzed and compared to sequences from 47 other South American populations to test hypotheses of whether increased female effective population size and gene flow influenced the mtDNA variation among central Andean populations. RESULTS: The Aymara and Quechua were genetically diverse showing evidence of population expansion and large effective population size, and a demographic expansion model fits the mtDNA variation found among central Andean populations well. Estimated migration rates and the results of AMOVA and multidimensional scaling analysis suggest that female gene flow was also an important factor, influencing genetic variation among the central Andeans as well as lowland populations from western South America. mtDNA variation in south central Andes correlated better with geographic proximity than with language, and fit a population continuity model. CONCLUSION: The mtDNA data suggests that the central Andeans experienced population expansion, most likely because of rapid demographic expansion after introduction of intensive agriculture, but roles of female gene flow need to be further explored.

Obesity prevention and management: Singapore's experience.

Singapore's obesity prevalence among adult Singapore residents aged 18-69 increased from 6.9% (2004) to 10.8% (2010). Among school-going children, the prevalence of overweight and severely overweight (body weight > 120% standard weight for height) increased from 1.4% (1976) to 12.7% (2006) for primary 1 students, and 2.2% to 15.9% for primary 6 students. Fundamentally, obesity is a function of excess energy intake (food consumption) and insufficient energy expenditure (physical activity). In 2010, about 40% did not have sufficient physical activity, and about 60% consumed excess energy. For students in the mainstream schools, only a fifth consumed at least two servings of fruits and vegetables every day, and a tenth were physically active for at least 60 min on 5 or more days a week. From a public health perspective, the most powerful levers for influencing population health lie in interventions that make healthy living convenient and an unconscious choice by targeting the social and environmental context. Recognizing this, the Health Promotion Board has in recent years made a strategic shift away from just public education campaigns aimed at individual behaviours, to focus on creating a ground-up social movement to enable and empower individuals to live out a healthy lifestyle.

Effects of aerobic conditioning on cardiovascular sympathetic response to and recovery from challenge.

Exercise has widely documented cardioprotective effects, but the mechanisms behind these effects are still poorly understood. Here, we test the hypothesis that aerobic training lowers cardiovascular sympathetic responses to and speeds recovery from challenge. We conducted a randomized, controlled trial contrasting aerobic versus strength training on indices of cardiac (pre-ejection period, PEP) and vascular (low-frequency blood pressure variability, LF-BPV) sympathetic responses to and recovery from psychological and orthostatic challenge in 149 young, healthy, sedentary adults. Aerobic and strength training did not alter PEP or LF-BPV reactivity to or recovery from challenge. These findings, from a large randomized, controlled trial using an intent-to-treat design, show that moderate aerobic exercise training has no effect on PEP and LF-BPV reactivity to or recovery from psychological or orthostatic challenge. In healthy young adults, the cardioprotective effects of exercise training are unlikely to be mediated by changes in sympathetic activity.

The association of cardiac vagal control and executive functioning--findings from the MIDUS study.

Cardiac vagal control (CVC), an index of parasympathetic contribution to cardiac regulation, has been linked to enhanced executive functioning (EF). However, findings to date have been based on small or unique samples. Additionally, previous studies assessed the CVC-EF link only during rest or recovery period from a cognitive challenge, but not during both states. In the present study, data on 817 socioeconomically diverse participants were obtained from the Midlife Development in the United States (MIDUS) study. As part of this study, participants completed cognitive tests, including EF, along with laboratory-based measures of CVC during rest and following recovery from a cognitive challenge. Regression analyses adjusting for respiratory rate revealed no effect of CVC at rest or during recovery on a global index of EF. However, exploratory post-hoc analyses of the components of the global EF index revealed a significant association between faster vagal recovery and better attention-switching and response inhibition abilities, as indexed by faster reaction time to the mixed SGST. This association remained significant after controlling for demographic, clinical (BMI, diseases and medications altering cardiac autonomic functioning, etc.), and health behavior covariates (Beta = .148, p = .010). Our findings suggest that future studies may need to investigate the links of CVC to specific EF abilities, rather than global measures of EF. Additionally, our results highlight the importance of assessing CVC during both rest and recovery from a cognitive challenge. The authors discuss the putative neurobiological underpinning of this link, as well as suggestions for future basic and clinical research.

Mitochondrial DNA diversity in two ethnic groups in southeastern Kenya: perspectives from the northeastern periphery of the Bantu expansion.

The Bantu languages are widely distributed throughout sub-Saharan Africa. Genetic research supports linguists and historians who argue that migration played an important role in the spread of this language family, but the genetic data also indicates a more complex process involving substantial gene flow with resident populations. In order to understand the Bantu expansion process in east Africa, mtDNA hypervariable region I variation in 352 individuals from the Taita and Mijikenda ethnic groups was analyzed, and we evaluated the interactions that took place between the Bantu- and non-Bantu-speaking populations in east Africa. The Taita and Mijikenda are Bantu-speaking agropastoralists from southeastern Kenya, at least some of whose ancestors probably migrated into the area as part of Bantu migrations that began around 3,000 BCE. Our analyses indicate that they show some distinctive differences that reflect their unique cultural histories. The Taita are genetically more diverse than the Mijikenda with larger estimates of genetic diversity. The Taita cluster with other east African groups, having high frequencies of haplogroups from that region, while the Mijikenda have high frequencies of central African haplogroups and cluster more closely with central African Bantu-speaking groups. The non-Bantu speakers who lived in southeastern Kenya before Bantu speaking groups arrived were at least partially incorporated into what are now Bantu-speaking Taita groups. In contrast, gene flow from non-Bantu speakers into the Mijikenda was more limited. These results suggest a more complex demographic history where the nature of Bantu and non-Bantu interactions varied throughout the area.

Sex-specific impact of maternal-fetal risk factors on depression and cardiovascular risk 40 years later.

Major depressive disorder (MDD) and cardiovascular disease (CVD) represent leading causes of morbidity and mortality worldwide. We tested the hypothesis that growth restriction and preeclampsia (referred to as fetal risk) are significant predictors of these conditions, with women at higher risk in adulthood. Adult offspring exposed to fetal risk factors and their discordant siblings were from two prenatal cohorts, whose mothers were followed through pregnancy and whom we recruited as adults 40 years later (n = 538; 250 males and 288 females). Subjects were psychiatrically diagnosed and underwent a stress challenge during which parasympathetic regulation was assessed by electrocardiogram, operationalized as high-frequency R-R interval variability (HF-RRV). Linear mixed models and generalized estimating equations were used to examine the relationship of fetal risk on HF-RRV, MDD and comorbidity of low HF-RRV (lowest 25th percentile) and MDD, including interactions with sex and socioeconomic status (SES). Fetal risk was significantly associated with low HF-RRV response (F = 3.64, P = 0.05), particularly among low SES (interaction: F = 4.31, P < 0.04). When stratified by MDD, the fetal risk impact was three times greater among MDD compared with non-MDD subjects (effect size: 0.21 v. 0.06). Females had a significantly higher risk for the comorbidity of MDD and low HF-RRV than males (relative risk (RR) = 1.36, 95% CI: 1.07-1.73), an association only seen among those exposed to fetal risk (RR = 1.38, 95% CI: 1.04-1.83). Findings suggest that these are shared fetal antecedents to the comorbidity of MDD and CVD risk 40 years later, an association stronger in females than in males.

Greater trochanteric pain syndrome, another cause of hip or thigh pain in multiple sclerosis.

This case report describes greater trochanteric pain syndrome (often referred to as trochanteric bursitis) in a patient with multiple sclerosis (MS). It is a relatively common and treatable cause of hip pain in patients with several underlying conditions. It is probably underdiagnosed in MS where other causes of pain, particularly neurogenic, are so often assumed.

Exercise training favourably affects autonomic and blood pressure responses during mental and physical stressors in African-American men.

Aerobic exercise is a powerful mechanism by which cardiovascular and autonomic parameters may be improved. We sought to quantify the extent of benefit that could be achieved by a short-term monitored exercise regimen on several autonomic parameters during recognized mental and physical stressors in young normotensive African-American men matched for a family history of hypertension, a group at high risk for the development of hypertension. Autonomic modulations were derived using spectral decomposition of the electrocardiogram and beat-to-beat blood pressures (BPs). Arterial compliance was obtained using contour analysis of the radial artery pulse wave. The analysis of variance revealed that compared with a matched sedentary control group, aerobic capacity of the trained group significantly increased by 16%. Autonomic modulations, arterial compliance and BP responses significantly improved during some of the stressors, whereas no such improvements were seen in the control group. Attenuated responses, mediated through a favourable shift in sympathovagal balance and enhanced arterial compliance, provide mechanistic evidence of how certain variables may be improved due to aerobic conditioning in a population at high risk for the development of hypertension.

The clinical scaphoid fracture: early computed tomography as a practical approach.

INTRODUCTION: Up to 40% of scaphoid fractures are missed at initial presentation as clinical examination and plain radiographs are poor at identifying scaphoid fractures immediately after the injury. Avoiding a delay in diagnosis is essential to prevent the risk of non-union and early wrist arthritis. We demonstrate the use of CT scanning for the early confirmation of a scaphoid fracture. PATIENTS AND METHODS: We conducted a retrospective, chronological review of patients who attended an upper limb fracture clinic from January 2001 to October 2003 in a small district general hospital. We performed a CT scan on all 'clinical scaphoid' patients who had negative plain X-ray films. RESULTS: Overall, 70% of patients had a CT scan within 1 week of injury and not from date of accident and emergency attendance; 83% of patients had a CT scan within 2 weeks of injury. Of 118 patients identified, 32% had positive findings and 22% of 'clinical scaphoid' patients had scaphoid fractures. The proportion of positive findings for an acute scaphoid fracture was 68%. Additional pathologies identified on CT were capitate, triquetral and radial fractures. CONCLUSIONS: Our audit shows that it is practical to perform CT on suspicious scaphoid fractures in a small district general hospital. We identified an extremely high false-negative rate for plain X-rays and demonstrate that the appropriate use of CT at initial fracture clinic attendance with 'clinical scaphoid' leads to an earlier diagnosis and reduces the need for prolonged immobilisation and repeated clinical review.

Genetic genealogy: the Woodson family's experience.

In 1998, Foster and colleagues published the results of a genetic study intended to test whether Thomas Jefferson could have fathered any of Sally Hemings' children. They found that the Jefferson Y chromosome haplotype matched that of a descendant of Hemings' youngest child, but not that of the descendants of the eldest son, Thomas Woodson. The Woodson descendants were shocked by the study's finding, which disagreed with their family oral history. They were suspicious of the study conclusions because of the methods used in recruiting participants for the study and the manner in which they learned of the results. The Woodsons' experience as participants in one of the first examples of genetic genealogy illustrates several issues that both geneticists and amateur genetic genealogists will face in studies of this kind. Misperceptions about the relationship between biology and race, and group genetics in general, can make the interpretation of genetic data difficult. Continuing collaborations between the media and the scientific community will help the public to better understand the risks as well as the benefits of genetic genealogy. Researchers must decide prior to beginning their research what role the human subjects will play in the study and when they will be notified of the study's conclusions. Amateur genetic genealogists should anticipate unexpected outcomes, such as the identification of nonpaternity, to minimize any harmful effects to study participants. Although modern genetic methods provide a powerful new tool for genealogical study, they cannot resolve all genealogical issues, as this study shows, and can involve unanticipated risks to the participants.

Pseudoaneurysm of profunda femoris artery following intertrochanteric fracture of the hip.

The authors report a case of pseudoaneurysm of the profunda femoris artery following fixation of an intertrochanteric hip fracture with a dynamic hip screw. Diagnosis and treatment of this rare complication are described.

Percutaneous endoscopic gastrostomy feeding in a district rehabilitation service.

OBJECTIVES: To examine gender, diagnosis, age, reasons for feeding, nutritional status, complications, outcome and duration of feeding in patients who have required a percutaneous endoscopic gastrostomy (PEG) for nutritional support at a district rehabilitation unit in the six years since the service was established. To identify potential for improvements in the management of future patients. DESIGN: Retrospective case note review of cases from 1992 to 1998. SETTING: District rehabilitation service for ages 16-64 serving the population of Fife, Scotland (population circa 350 000). SUBJECTS: All patients (n = 42) who had been fed via a PEG feeding tube in the previous six years. RESULTS: Forty-four PEG tube insertions had been conducted for 43 episodes of feeding in 42 patients. Five episodes of feeding were because of persistent vegetative state or low awareness state and 38 because of neurological swallowing impairment. Twenty-six (60%) patients were nutritionally depleted when PEG feeding was commenced. Twenty-seven (64%) patients experienced minor complications and 15 (34%) had no complications. At three months post procedure four (9.5%) patients had died and 21 (50%) had been discharged home. The mean duration of feeding on 31 October 1998 of the 20 patients (48%) who continued feeding at that date was 3.19+/-1.89 (mean +/- SD) years. CONCLUSIONS: Patients requiring PEG feeding in a district rehabilitation service have a range of diagnoses and the main indication for intervention is neurological swallowing impairment. The majority of patients were nutritionally depleted when feeding commenced and the reasons for this require further investigation.

Nuclear and mitochondrial genetic variation in the Yanomamö: a test case for ancient DNA studies of prehistoric populations.

Ancient DNA provides a potentially revolutionary way to study biological relationships in prehistoric populations, but genetic patterns are complex and require careful interpretation based on robust, well-tested models. In this study, nuclear and mitochondrial markers were compared in the Yanomamö, to assess how well each data set could differentiate among closely related groups. The villages selected for the study share a recent fission history and are closely related to each other, as would likely be the case among prehistoric peoples living in the same valley or region. The Yanomamö generally practice village-level endogamy, but some migration and gene flow are known to occur between villages. Nuclear and mitochondrial DNA data were compared using F-statistics and genetic distance analyses. The nuclear data performed as expected, males and females from the same village were similar, and the villages were genetically distinct, with the magnitude of genetic differences correlated with historical relationship. However, mtDNA analyses did not yield the expected results. The genetic distances between villages did not correlate with historical relationship, and the sexes were significantly different from each other in two villages. Both the Lane and Sublett and the Spence methods, used to test for archaeological residence patterns, were consistent with endogamy. Hence, ancient DNA can, in principle, provide us with a unique opportunity to study genetic structure and gene flow in archaeological populations. However, interpretations, particularly those based on single loci such as mitochondrial DNA, should be cautious because sex-specific migration and sampling issues may have dramatic effects.

Benzodiazepines and related drugs for insomnia in palliative care.

BACKGROUND: Insomnia, a subjective complaint of poor sleep and associated impairment in daytime function, is a common problem. Currently, benzodiazepines are the most used pharmacological treatment for this complaint. They are considered helpful for occasional short-term use up to four weeks but longer term use is not advised due to potential problems regarding tolerance, dosing escalation, psychological addiction and physical dependence. There is no consensus on their utility in patients with progressive incurable conditions who may require assistance with sleep for many weeks as their condition deteriorates. OBJECTIVES: To assess the effectiveness and safety of benzodiazepines or benzodiazepine receptor agonists such as Zolpidem, Zopiclone and Zaleplon for insomnia in palliative care. SEARCH STRATEGY: Several electronic databases were searched including Cochrane PaPaS Group specialized register, Cochrane Library Issue 4, 2001, MEDLINE, EMBASE, BNI plus, CINAHL, BIOLOGICAL ABSTRACTS, PSYCINFO, CANCERLIT, HEALTHSTAR, WEB OF SCIENCE, SIGLE, Dissertation Abstracts, ZETOC and the MetaRegister of ongoing trials. These were searched from 1960 to 2001 or as much of this range as possible. Additional articles were sought by handsearching reference lists in standard textbooks and reviews in the field and by contacting academic centres in palliative care and pharmaceutical companies. There were no language restrictions. SELECTION CRITERIA: Studies considered for inclusion were randomized controlled trials of adult patients in any setting, receiving palliative care or suffering an incurable progressive medical condition. (For example, cancers, AIDS, Motor Neurone Disease, Multiple Sclerosis, Parkinson's Disease, Chronic Obstructive Pulmonary Disease). There had to be an explicit complaint of insomnia in study participants, diagnosed by any of the three main classification systems (DSM-IV (APA 1994), ICSD (AASD 1990) or ICD (WHO 1992)), or as described in the study if it involved a subjective complaint of poor sleep. Studies had to compare a benzodiazepine or Zolpidem or Zopiclone or Zaleplon with placebo or active control for the treatment of insomnia. Any duration of therapy were considered. DATA COLLECTION AND ANALYSIS: Abstracts were independently inspected by both reviewers, full papers were obtained where necessary. Where there was uncertainty advice was sought by a third (PW). Data extraction and quality assessments were undertaken independently by both reviewers. MAIN RESULTS: No randomized controlled trials were identified meeting the a priori inclusion criteria. Thirty-seven studies were considered but all were excluded from the review. REVIEWER'S CONCLUSIONS: Despite a comprehensive search no evidence from randomized controlled trials was identified. It was not possible to draw any conclusions regarding the use of benzodiazepines in palliative care.