Chronology as topic

Abstract
Aim  To test whether alcohol is a risk factor for sudden infant death syndrome (SIDS).
Design and setting  US epidemiological study using computerized death certificates, linked birth and infant death dataset, and Fatality Analysis Reporting System.
Participants  All SIDS cases (n = 129,090) and other infant deaths (n = 295,151) from 1973–2006; all persons involved in late‐night alcohol‐related crashes (n = 135,946) from 1994–2008.
Measurements  Three measures were used: the expected number of deaths on New Year versus the observed number (expected values were determined using a locally weighted scatterplot smoothing polynomial), the average number of weekend deaths versus the average number of weekday deaths, and the SIDS death rate for children of alcohol‐consuming versus non‐alcohol‐consuming mothers.
Findings  These measures indicate that the largest spikes in alcohol consumption and in SIDS (33%) occur on New Year, alcohol consumption and SIDS increase significantly on weekends, and children of alcohol‐consuming mothers are much more likely to die from SIDS than are children of non‐alcohol‐consuming mothers.
Conclusions  Alcohol consumption appears to be a risk factor for sudden infant death syndrome, although it is unclear whether alcohol is an independent risk factor, a risk factor only in conjunction with other known risk factors (like co‐sleeping), or a proxy for other risk factors associated with occasions when alcohol consumption increases (like smoking). Our findings suggest that caretakers and authorities should be informed that alcohol impairs parental capacity and might be a risk factor for sudden infant death syndrome; in addition, future research should further explore possible connections between sudden infant death syndrome and alcohol.

This paper considers the recent radiometric dating (14C-AMS, TL, ESR) of 76 late Middle and early Upper Paleolithic samples from Ortvale Klde Rockshelter, located in the Republic of Georgia. We present a critical evaluation of each date based on its stratigraphic and archaeological context, its pretreatment and contamination history, and its resulting accuracy and precision, the goal being to establish

StW 573, Little Foot, is the most complete Australopithecus skeleton yet discovered, with many of its bones found in their correct anatomical position. Since the discovery of the in situ skeleton in the Silberberg Grotto in 1997, several teams have attempted to date the fossil. This appeared a simple process because several flowstones are inter-bedded in the breccia above and below StW 573. Dating of these flowstones, using U-Pb (uranium-lead) isotope decay techniques, gave younger results than expected from the fauna and stratigraphic position, around 2.2 Ma (millions of years). Our recent stratigraphic, micromorphological and geochemical studies revealed that the stratigraphy is much more complicated than was previously thought, with localized post-depositional processes leading to the creation of voids within the breccia around the skeleton. These voids were then filled by multiple generations of flowstone growth. The research we present here demonstrates that the proposed dates based on the flowstone deposition can give only a minimum age for StW 573 and that the flowstone formation came after, and probably long after, the breccia deposition. If one takes account of the long evolution of these karst fillings, StW 573 appears to be significantly older than 2.2 Ma.

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day 'modern' morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens 1 or evolved gradually over the last 400 thousand years 2. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 t...

It has been shown that the activation of cytosolic superoxide dismutase (Sod1) in Saccharomyces cerevisiae is only dependent on Ccs1, which is responsible for insertion of copper into the enzyme catalytic center, and that glutathione (GSH) is not necessary for this process. In this work, we addressed an important role of GSH in Sod1 activation by a Ccs1-dependent mechanism during oxidative stress and its role in yeast lifespan. Exponential cells of Saccharomyces cerevisiae, treated or not with 0.5 mM menadione for 1 h, were used for evaluation of the effect of a mild oxidative stress pre-treatment on chronological lifespan. The results showed that menadione induced a lifespan extension in the wild-type (WT) strain but this adaptive response was repressed in gsh1 and in sod1 strains. Interestingly, menadione treatment increased SOD1 and CCS1 gene expression in both WT and gsh1 strains. However, while these strains showed the same Sod1 activity before treatment, only the WT presented an increase of Sod1 activity after menadione exposure. Glutathionylation seems to be essential for Sod1 activation since no increase in activity was observed after menadione treatment in grx1 and grx2 null mutants. Our results suggest that GSH and glutathionylation are fundamental to protect Sod1 sulfhydryl residues under mild oxidative stress, enabling Sod1 activation and lifespan extension.

The timing and location of the emergence of our species and of associated behavioural changes are crucial for our understanding of human evolution. The earliest fossil attributed to a modern form of Homo sapiens comes from eastern Africa and is approximately 195 thousand years old, therefore the emergence of modern human biology is commonly placed at around 200 thousand years ago. The earliest Middle Stone Age assemblages come from eastern and southern Africa but date much earlier. Here we report the ages, determined by thermoluminescence dating, of fire-heated flint artefacts obtained from new excavations at the Middle Stone Age site of Jebel Irhoud, Morocco, which are directly associated with newly discovered remains of H. sapiens. A weighted average age places these Middle Stone Age artefacts and fossils at 315 ± 34 thousand years ago. Support is obtained through the recalculated uranium series with electron spin resonance date of 286 ± 32 thousand years ago for a tooth from the ...

The timing and location of the emergence of our species and of associated behavioural changes are crucial for our understanding of human evolution. The earliest fossil attributed to a modern form of Homo sapiens comes from eastern Africa and is approximately 195 thousand years old, therefore the emergence of modern human biology is commonly placed at around 200 thousand years ago. The earliest Middle Stone Age assemblages come from eastern and southern Africa but date much earlier. Here we report the ages, determined by thermoluminescence dating, of fire-heated flint artefacts obtained from new excavations at the Middle Stone Age site of Jebel Irhoud, Morocco, which are directly associated with newly discovered remains of H. sapiens. A weighted average age places these Middle Stone Age artefacts and fossils at 315 ± 34 thousand years ago. Support is obtained through the recalculated uranium series with electron spin resonance date of 286 ± 32 thousand years ago for a tooth from the ...

Fossil evidence points to an African origin of Homo sapiens from a group called either H. heidelbergensis or H. rhodesiensis. However, the exact place and time of emergence of H. sapiens remain obscure because the fossil record is scarce and the chronological age of many key specimens remains uncertain. In particular, it is unclear whether the present day 'modern' morphology rapidly emerged approximately 200 thousand years ago (ka) among earlier representatives of H. sapiens or evolved gradually over the last 400 thousand years. Here we report newly discovered human fossils from Jebel Irhoud, Morocco, and interpret the affinities of the hominins from this site with other archaic and recent human groups. We identified a mosaic of features including facial, mandibular and dental morphology that aligns the Jebel Irhoud material with early or recent anatomically modern humans and more primitive neurocranial and endocranial morphology. In combination with an age of 315 ± 34 thous...

Soot marks, witnesses of past human activities, can sometimes be noticed in concretions (speleothem, travertine, carbonated crust, etc.) formed in cavities. We demonstrate here that these deposits, generally ignored in archaeological studies, turned out to be a perfectly suitable material for micro-chronological study of hominin activities in a site. At the Grotte Mandrin (Mediterranean France), thousands of clastic fragments from the rock walls were found in every archaeological level of the shelter. Calcareous crusts containing soot deposits are recorded on some of their surfaces. They appear in thin section as thin black laminae. Microscopic observation of these crusts revealed that they kept track of many occupations. We show that is possible to link them with the archaeological units identified during the excavation. Minimum Number of Occupations (MNO) can be built out of these sooted crusts. MNO are usually high and attest to the cumulative nature of each archaeological unit. ...

Handaxe-bearing sites in China are currently known to occur in a number of alluvial basins, the best known being Dingcun, Bose and Luonan. Bose in the south and Luonan in central China on the northern margin of the Qinling Mountains are most familiar to English-speaking researchers. Here we document the Danjiangkou Reservoir Region (DRR) as another major area for large cutting tools (LCTs), located in central China on the southeastern edge of the Qinling Mountains. Large cutting tools are preserved in three terraces of the Han and Dan Rivers in Hubei and Henan Provinces, with dates from ca. 0.8 Ma (millions of years ago) (Terrace 4) to the first half of the Middle Pleistocene (Terrace 3), and possibly to the Late Pleistocene (Terrace 2). This paper reports on LCTs discovered in Terraces 3 and 2, with a majority from the older terrace (and one specimen from Terrace 4). Regional environments during the Middle Pleistocene were relatively warm, humid and stable. Despite the poor quality...

By the early twentieth century there was a growing need within palaeoanthropology and prehistoric archaeology to find a way of dating fossils and artefacts in order to know the age of specific specimens, but more importantly to establish an absolute chronology for human prehistory. The radiocarbon and potassium–argon dating methods revolutionized palaeoanthropology during the last half of the twentieth century. However, prior to the invention of these methods there were attempts to devise chemical means of dating fossil bone. Collaborations between Emile Rivière and Adolphe Carnot in the 1890s led to the development of the fluorine dating method, but it was not until the 1940s that this method was improved and widely implemented by Kenneth Oakley to resolve a number of problems in palaeoanthropology, including the Piltdown Man controversy. The invention of the fluorine dating method marked a significant advance in the quest for absolute dating in palaeoanthropology, but it also high...

The discovery and first dates of the paintings in Grotte Chauvet provoked a new debate on the origin and characteristics of the first figurative Palaeolithic art. Since then, other art ensembles in France and Italy (Aldène, Fumane, Arcy-sur-Cure and Castanet) have enlarged our knowledge of graphic activity in the early Upper Palaeolithic. This paper presents a chronological assessment of the Palaeolithic parietal ensemble in Altxerri B (northern Spain). When the study began in 2011, one of our main objectives was to determine the age of this pictorial phase in the cave. Archaeological, geological and stylistic evidence, together with radiometric dates, suggest an Aurignacian chronology for this art. The ensemble in Altxerri B can therefore be added to the small but growing number of sites dated in this period, corroborating the hypothesis of more complex and varied figurative art than had been supposed in the early Upper Palaeolithic.

It has been postulated that patients admitted on weekends or after office hours may experience delays in clinical management and consequently have longer length of stay (LOS). We investigated if day and time of admission is associated with LOS in Tan Tock Seng Hospital (TTSH), a 1,400 bed acute care tertiary hospital serving the central and northern regions of Singapore. This was a historical cohort study based on all admissions from TTSH from 1st September 2003 to 31st August 2004. Data was extracted from routinely available computerized hospital information systems for analysis by episode of care. LOS for each episode of care was log-transformed before analysis, and a multivariate linear regression model was used to study if sex, age group, type of admission, admission source, day of week admitted, admission on a public holiday or eve of public holiday, admission on a weekend and admission time were associated with an increased LOS. In the multivariate analysis, sex, age group, ty...

Published data from DNA sequences, morphology of 11 extant and 15 extinct frog taxa, and stratigraphic ranges of fossils were integrated to open a window into the deep-time evolution of Xenopus. The ages and morphological characters of fossils were used as independent datasets to calibrate a chronogram. We found that DNA sequences, either alone or in combination with morphological data and fossils, tended to support a close relationship between Xenopus and Hymenochirus, although in some analyses this topology was not significantly better than the Pipa + Hymenochirus topology. Analyses that excluded DNA data found strong support for the Pipa + Hymenochirus tree. The criterion for selecting the maximum age of the calibration prior influenced the age estimates, and our age estimates of early divergences in the tree of frogs are substantially younger than those of published studies. Node-dating and tip-dating calibrations, either alone or in combination, yielded older dates for nodes th...

We report the discovery and present a detailed analysis of a freshwater bivalve from Shuidonggou Locality 2, layer CL3. This layer is located c. 40 cm below layer CL2, which has yielded numerous ostrich eggshell beads. The shell is identified as the valve of a Corbicula fluminea. Data on the occurrence of this species in the Shuidonggou region during Marine Isotope Stage 3 and taphonomic analysis, conducted in the framework of this study, of a modern biocoenosis and thanatocoenosis suggest that the archeological specimen was collected at one of the numerous fossil or sub-fossil outcrops where valves of this species were available at the time of occupation of level CL3. Experimental grinding and microscopic analysis of modern shells of the same species indicate that the Shuidonggou shell was most probably ground on coarse sandstone to open a hole on its umbo, attach a thread, and use the valve as a personal ornament. Experimental engraving of freshwater shells and microscopic analysi...

Pinnacle Point Cave 13B (PP13B) has provided the earliest archaeological evidence for the exploitation of marine shellfish, along with very early evidence for use and modification of pigments and the production of bladelets, all dated to approximately 164 ka (Marean et al., 2007). This makes PP13B a key site in studies of the origins of modern humans, one of a handful of sites in Africa dating to Marine Isotope Stage 6 (MIS 6), and the only site on the coast of South Africa with human occupation confidently dated to MIS 6. Along with this MIS 6 occupation there are rich archaeological sediments dated to MIS 5, and together these sediments are differentially preserved in three different areas of the cave. The sediments represent a complex palimpsest of geogenic, biogenic, and anthropogenic input and alteration that are described and interpreted through the use of a variety of macrostratigraphic, micromorphologic, and geochemical techniques. Three independent dating techniques allow u...

StW 573, Little Foot, is the most complete Australopithecus skeleton yet discovered, with many of its bones found in their correct anatomical position. Since the discovery of the in situ skeleton in the Silberberg Grotto in 1997, several teams have attempted to date the fossil. This appeared a simple process because several flowstones are inter-bedded in the breccia above and below StW 573. Dating of these flowstones, using U-Pb (uranium-lead) isotope decay techniques, gave younger results than expected from the fauna and stratigraphic position, around 2.2 Ma (millions of years). Our recent stratigraphic, micromorphological and geochemical studies revealed that the stratigraphy is much more complicated than was previously thought, with localized post-depositional processes leading to the creation of voids within the breccia around the skeleton. These voids were then filled by multiple generations of flowstone growth. The research we present here demonstrates that the proposed dates based on the flowstone deposition can give only a minimum age for StW 573 and that the flowstone formation came after, and probably long after, the breccia deposition. If one takes account of the long evolution of these karst fillings, StW 573 appears to be significantly older than 2.2 Ma.

Background. To study the effects of an aqueous extract of date fruit (Phoenix dactyliferaL. Arecaceae) diet on diabetic polyneuropathy (DPN) in streptozotocin- (STZ-) induced diabetic rats.Methods. The effects of a date fruit extract (DFE) diet on diabetic neuropathy in STZ-induced diabetic rats were evaluated and compared with a nondiabetic control group, diabetic control group (sham), and vehicle group with respect to the following parameters: open field behavioral test, motor nerve conduction velocity (MNCV), and morphological observations.Results. In the model of STZ-induced of diabetic neuropathy, chronic treatment for 6 weeks with DFE counteracted the impairment of the explorative activity of the rats in an open field behavioral test and of the conduction velocity of the sciatic nerve (MNCV). In addition, pretreatment with DFE significantly reversed each nerve diameter reduction in diabetic rats.Conclusion. DFE treatment shows efficacy for preventing diabetic deterioration and...

This paper considers the recent radiometric dating (14C-AMS, TL, ESR) of 76 late Middle and early Upper Paleolithic samples from Ortvale Klde Rockshelter, located in the Republic of Georgia. We present a critical evaluation of each date based on its stratigraphic and archaeological context, its pretreatment and contamination history, and its resulting accuracy and precision, the goal being to establish

The natural course of Behçet's disease is not fully known. The aim of the present study was to determine the occurrence of the symptoms retrospectively in chronologic order in patients with Behçet's disease, diagnosed according to the criteria of the International Study Group for Behçet's Disease. A total of 60 consecutive patients (29 male and 31 female; aged 35.87 +/- 9.84 years) were involved in the study. The symptoms of the disease were retrospectively recorded in the time order of the manifestations per patient. Oral ulcer was the most commonly observed onset manifestation (51 of 60 patients: 85%), followed by genital ulcer (13 of 60 patients: 21.7%) and articular symptoms (10 of 60 patients: 16.7%). The duration between the oral ulcer and the fulfillment of diagnostic criteria was calculated to be 3.77 +/- 4.43 years. The same duration was 2.50 +/- 4.74 and 2.11 +/- 3.44 years for genital ulcer and articular symptoms, respectively. The duration between the time point of fulfillment of diagnostic criteria and the diagnosis (2.83 +/- 2.3 years) was found to be longer in female patients (3.2 +/- 2.5 years). The duration was also longer in patients having only mucocutaneous lesions (3.18 +/- 2.5 years) than in patients having serious organ involvement such as eye disease (1.63 +/- 0.7 years; p < 0.05). Our study indicates that oral ulcer is the onset manifestation in the majority of the patients and the disease is often diagnosed with a delay of several years after the appearance of the onset sign.

Cycles of demographic and organizational change are well documented in Neolithic societies, but the social and ecological processes underlying them are debated. Such periodicities are implicit in the "Pecos classification," a chronology for the pre-Hispanic U.S. Southwest introduced in Science in 1927 which is still widely used. To understand these periodicities, we analyzed 29,311 archaeological tree-ring dates from A.D. 500 to 1400 in the context of a novel high spatial resolution, annual reconstruction of the maize dry-farming niche for this same period. We argue that each of the Pecos periods initially incorporates an "exploration" phase, followed by a phase of "exploitation" of niches that are simultaneously ecological, cultural, and organizational. Exploitation phases characterized by demographic expansion and aggregation ended with climatically driven downturns in agricultural favorability, undermining important bases for social consensus. Explor...

Soot marks, witnesses of past human activities, can sometimes be noticed in concretions (speleothem, travertine, carbonated crust, etc.) formed in cavities. We demonstrate here that these deposits, generally ignored in archaeological studies, turned out to be a perfectly suitable material for micro-chronological study of hominin activities in a site. At the Grotte Mandrin (Mediterranean France), thousands of clastic fragments from the rock walls were found in every archaeological level of the shelter. Calcareous crusts containing soot deposits are recorded on some of their surfaces. They appear in thin section as thin black laminae. Microscopic observation of these crusts revealed that they kept track of many occupations. We show that is possible to link them with the archaeological units identified during the excavation. Minimum Number of Occupations (MNO) can be built out of these sooted crusts. MNO are usually high and attest to the cumulative nature of each archaeological unit. ...