RESUMO
The largest ever primate and one of the largest of the southeast Asian megafauna, Gigantopithecus blacki1, persisted in China from about 2.0 million years until the late middle Pleistocene when it became extinct2-4. Its demise is enigmatic considering that it was one of the few Asian great apes to go extinct in the last 2.6 million years, whereas others, including orangutan, survived until the present5. The cause of the disappearance of G. blacki remains unresolved but could shed light on primate resilience and the fate of megafauna in this region6. Here we applied three multidisciplinary analyses-timing, past environments and behaviour-to 22 caves in southern China. We used 157 radiometric ages from six dating techniques to establish a timeline for the demise of G. blacki. We show that from 2.3 million years ago the environment was a mosaic of forests and grasses, providing ideal conditions for thriving G. blacki populations. However, just before and during the extinction window between 295,000 and 215,000 years ago there was enhanced environmental variability from increased seasonality, which caused changes in plant communities and an increase in open forest environments. Although its close relative Pongo weidenreichi managed to adapt its dietary preferences and behaviour to this variability, G. blacki showed signs of chronic stress and dwindling populations. Ultimately its struggle to adapt led to the extinction of the greatest primate to ever inhabit the Earth.
Assuntos
Extinção Biológica , Fósseis , Hominidae , Animais , Cavernas , China , Dieta/veterinária , Florestas , Hominidae/classificação , Plantas , Pongo , Datação Radiométrica , Estações do Ano , Fatores de TempoRESUMO
Homo erectus is the founding early hominin species of Island Southeast Asia, and reached Java (Indonesia) more than 1.5 million years ago1,2. Twelve H. erectus calvaria (skull caps) and two tibiae (lower leg bones) were discovered from a bone bed located about 20 m above the Solo River at Ngandong (Central Java) between 1931 and 19333,4, and are of the youngest, most-advanced form of H. erectus5-8. Despite the importance of the Ngandong fossils, the relationship between the fossils, terrace fill and ages have been heavily debated9-14. Here, to resolve the age of the Ngandong evidence, we use Bayesian modelling of 52 radiometric age estimates to establish-to our knowledge-the first robust chronology at regional, valley and local scales. We used uranium-series dating of speleothems to constrain regional landscape evolution; luminescence, 40argon/39argon (40Ar/39Ar) and uranium-series dating to constrain the sequence of terrace evolution; and applied uranium-series and uranium series-electron-spin resonance (US-ESR) dating to non-human fossils to directly date our re-excavation of Ngandong5,15. We show that at least by 500 thousand years ago (ka) the Solo River was diverted into the Kendeng Hills, and that it formed the Solo terrace sequence between 316 and 31 ka and the Ngandong terrace between about 140 and 92 ka. Non-human fossils recovered during the re-excavation of Ngandong date to between 109 and 106 ka (uranium-series minimum)16 and 134 and 118 ka (US-ESR), with modelled ages of 117 to 108 thousand years (kyr) for the H. erectus bone bed, which accumulated during flood conditions3,17. These results negate the extreme ages that have been proposed for the site and solidify Ngandong as the last known occurrence of this long-lived species.
Assuntos
Hominidae , Animais , Evolução Biológica , Fósseis , Indonésia , Ossos da Perna , Crânio , Fatores de TempoRESUMO
Humans seem to have an adaptive predisposition for inventing, telling and consuming stories1. Prehistoric cave art provides the most direct insight that we have into the earliest storytelling2-5, in the form of narrative compositions or 'scenes'2,5 that feature clear figurative depictions of sets of figures in spatial proximity to each other, and from which one can infer actions taking place among the figures5. The Upper Palaeolithic cave art of Europe hosts the oldest previously known images of humans and animals interacting in recognizable scenes2,5, and of therianthropes6,7-abstract beings that combine qualities of both people and animals, and which arguably communicated narrative fiction of some kind (folklore, religious myths, spiritual beliefs and so on). In this record of creative expression (spanning from about 40 thousand years ago (ka) until the beginning of the Holocene epoch at around 10 ka), scenes in cave art are generally rare and chronologically late (dating to about 21-14 ka)7, and clear representations of therianthropes are uncommon6-the oldest such image is a carved figurine from Germany of a human with a feline head (dated to about 40-39 ka)8. Here we describe an elaborate rock art panel from the limestone cave of Leang Bulu' Sipong 4 (Sulawesi, Indonesia) that portrays several figures that appear to represent therianthropes hunting wild pigs and dwarf bovids; this painting has been dated to at least 43.9 ka on the basis of uranium-series analysis of overlying speleothems. This hunting scene is-to our knowledge-currently the oldest pictorial record of storytelling and the earliest figurative artwork in the world.
Assuntos
Pinturas/história , Animais , Bovinos , Cavernas , Feminino , História Antiga , Atividades Humanas/história , Humanos , Indonésia , Narração/história , Datação Radiométrica , SuínosRESUMO
Preexploitation shark baselines and the history of human impact on coral reef-associated shark communities in the Caribbean are tpoorly understood. We recovered shark dermal denticles from mid-Holocene (â¼7 ky ago) and modern reef sediments in Bocas del Toro, Caribbean Panama, to reconstruct an empirical shark baseline before major human impact and to quantify how much the modern shark community in the region had shifted from this historical reference point. We found that denticle accumulation rates, a proxy for shark abundance, declined by 71% since the mid-Holocene. All denticle morphotypes, which reflect shark community composition, experienced significant losses, but those morphotypes found on fast-swimming, pelagic sharks (e.g., families Carcharhinidae and Sphyrnidae) declined the most. An analysis of historical records suggested that the steepest decline in shark abundance occurred in the late 20th century, coinciding with the advent of a targeted shark fishery in Panama. Although the disproportionate loss of denticles characterizing pelagic sharks was consistent with overfishing, the large reduction in denticles characterizing demersal species with low commercial value (i.e., the nurse shark Ginglymostoma cirratum) indicated that other stressors could have exacerbated these declines. We demonstrate that the denticle record can reveal changes in shark communities over long ecological timescales, helping to contextualize contemporary abundances and inform shark management and ecology.
Assuntos
Escamas de Animais , Recifes de Corais , Fósseis , Tubarões/fisiologia , Escamas de Animais/citologia , Escamas de Animais/fisiologia , Animais , Região do Caribe , Conservação dos Recursos Naturais , Sedimentos Geológicos/química , Atividades Humanas , Humanos , Panamá , Tubarões/classificação , Fatores de TempoRESUMO
Homo floresiensis, a primitive hominin species discovered in Late Pleistocene sediments at Liang Bua (Flores, Indonesia), has generated wide interest and scientific debate. A major reason this taxon is controversial is because the H. floresiensis-bearing deposits, which include associated stone artefacts and remains of other extinct endemic fauna, were dated to between about 95 and 12 thousand calendar years (kyr) ago. These ages suggested that H. floresiensis survived until long after modern humans reached Australia by ~50 kyr ago. Here we report new stratigraphic and chronological evidence from Liang Bua that does not support the ages inferred previously for the H. floresiensis holotype (LB1), ~18 thousand calibrated radiocarbon years before present (kyr cal. BP), or the time of last appearance of this species (about 17 or 13-11 kyr cal. BP). Instead, the skeletal remains of H. floresiensis and the deposits containing them are dated to between about 100 and 60 kyr ago, whereas stone artefacts attributable to this species range from about 190 to 50 kyr in age. Whether H. floresiensis survived after 50 kyr ago--potentially encountering modern humans on Flores or other hominins dispersing through southeast Asia, such as Denisovans--is an open question.
Assuntos
Arqueologia , Fósseis , Hominidae , Datação Radiométrica , Silicatos de Alumínio , Animais , Austrália , Calibragem , Cavernas , Sedimentos Geológicos/análise , Vidro , Humanos , Indonésia , Compostos de Potássio , Quartzo , Fatores de Tempo , IncertezaRESUMO
OBJECTIVE: To observe the recovery of urinary continence through postoperative rehabilitation training after robot-assisted laparoscopic radical prostatectomy (RARP) versus that after traditional laparoscopic radical prostatectomy (LRP). METHODS: This study included 64 cases of urinary incontinence after surgically treated for PCa from May 2017 to February 2021, 32 by RARP and the other 32 by LRP as the controls. All the patients received standard urinary continence rehabilitation training and routine nursing care postoperatively, followed by comparison of the rate and time of urinary incontinence recovery and the patients' scores on the quality of life (QOL) and satisfaction with treatment between the two groups. RESULTS: There were no statistically significant differences in age, PSA level or pathological stage between the two groups of patients (P > 0.05). After standard urinary continence rehabilitation training, the patients in the RARP group, compared with those in the LRP control, showed a lower grade of urinary incontinence (χ2 = 6.483, P = 0.039), a shorter mean duration of urinary incontinence per day, an earlier recovery of urinary continence (χ2 = 4.73, P = 0.030 at 1ï¼3 months; χ2 = 12.696, P < 0.001 at 4ï¼6 months), a higher rate of overall recovery (χ2 = 13.396, P = 0.004), and higher scores on QOL and satisfaction with treatment. CONCLUSION: RARP can effectively improve the recovery from postoperative urinary incontinence in PCa patients.
Assuntos
Laparoscopia , Neoplasias da Próstata , Procedimentos Cirúrgicos Robóticos , Robótica , Incontinência Urinária , Masculino , Humanos , Qualidade de Vida , Resultado do Tratamento , Incontinência Urinária/cirurgia , Neoplasias da Próstata/cirurgia , Neoplasias da Próstata/patologia , Prostatectomia/efeitos adversos , Recuperação de Função FisiológicaRESUMO
OBJECTIVE: To investigate the molecular mechanism of hsa_circ_0005221 regulating the progression of PCa through the miR-339-5p/STAT5a pathway. METHODS: Localizations of hsa_circ_0005221 and miR-339-5p in cells were detected by nuclear-cytoplasmic isolation. MiRNA-339-5p was selected as the target miRNA bound to hsa_circ_0005221 by RNA pull-down assay. The binding site of the luciferase reporter gene was predicted by software and the binding capability of miR-339-5p validated by luciferase assay. The expression of hsa_circ_0005221 in the prostatic epithelial and PCa cells was determined by qPCR. The hsa_circ_0005221-overexpressed plasmid and siRNA were transfected into the PCa cells for measurement of their proliferation, invasion and migration abilities and the levels of epithelial-mesenchymal transformation (EMT) and apoptosis. After knockdown of hsa_circ_0005221 and transfection of miR-339-5p mimics and miR-339-5p inhibitor, the proliferation, invasion and migration abilities of the DU145 and LNCaP cells were detected, and so were the levels of the EMT signature protein, STAT5a and cell apoptosis. RESULTS: The expression of hsa_circ_0005221 was significantly higher in the PCa than in the prostatic epithelial cells. Nuclear-cytoplasmic isolation experiments showed that hsa_circ_0005221 and miR-339-5p were mainly located in the cytoplasm. The proliferation, invasion and migration abilities and EMT were decreased and the apoptosis increased in the DU145 and LNCaP cells with knockdown of hsa_circ_0005221, which was just the reverse in those with overexpressed hsa_circ_0005221. Among the top 5 miRNAs predicted by software, miR-339-5p, miR-17 and miR-520h were shown by pull-down assay to be bound to hsa_circ_0005221, with most obvious changes in miR-339-5p when hsa_circ_0005221 knocked down or overexpressed. Luciferase reporter gene assay showed the binding of hsa_circ_0005221 to miR-339-5p. Knockdown of hsa_circ_0005221 and transfection of miR-339-5p mimics into the DU145 and LNCaP cells significantly reduced the proliferation, invasion and migration abilities of the cells and the N-cad level, increased their apoptosis and E-cad level, and up-regulated the expression of STAT5a, while overexpression of hsa_circ_0005221 and transfection of miR-339-5p mimics induced just the opposite effects. CONCLUSIONS: Hsa_circ_0005221 enhances the progression of prostate cancer through the miR-339-5p/STAT5a pathway.
Assuntos
MicroRNAs , Neoplasias da Próstata , RNA Circular/genética , Fator de Transcrição STAT5 , Humanos , Masculino , MicroRNAs/genética , Pelve , Próstata , Neoplasias da Próstata/genética , RNA Interferente Pequeno , Fator de Transcrição STAT5/genética , Proteínas Supressoras de TumorRESUMO
Hard coral cover on the Great Barrier Reef (GBR) is on a trajectory of decline. However, little is known about past coral mortality before the advent of long-term monitoring (circa 1980s). Using paleoecological analysis and high-precision uranium-thorium (U-Th) dating, we reveal an extensive loss of branching Acropora corals and changes in coral community structure in the Palm Islands region of the central GBR over the past century. In 2008, dead coral assemblages were dominated by large, branching Acropora and living coral assemblages by genera typically found in turbid inshore environments. The timing of Acropora mortality was found to be occasionally synchronous among reefs and frequently linked to discrete disturbance events, occurring in the 1920s to 1960s and again in the 1980s to 1990s. Surveys conducted in 2014 revealed low Acropora cover (<5%) across all sites, with very little evidence of change for up to 60 y at some sites. Collectively, our results suggest a loss of resilience of this formerly dominant key framework builder at a regional scale, with recovery severely lagging behind predictions. Our study implies that the management of these reefs may be predicated on a shifted baseline.
Assuntos
Antozoários/crescimento & desenvolvimento , Recifes de Corais , Monitoramento Ambiental/métodos , Aquecimento Global , Datação Radiométrica/métodos , Animais , Austrália , Tório/química , Urânio/químicaRESUMO
Wallacea, the zone of oceanic islands separating the continental regions of Southeast Asia and Australia, has yielded sparse evidence for the symbolic culture of early modern humans. Here we report evidence for symbolic activity 30,000-22,000 y ago at Leang Bulu Bettue, a cave and rock-shelter site on the Wallacean island of Sulawesi. We describe hitherto undocumented practices of personal ornamentation and portable art, alongside evidence for pigment processing and use in deposits that are the same age as dated rock art in the surrounding karst region. Previously, assemblages of multiple and diverse types of Pleistocene "symbolic" artifacts were entirely unknown from this region. The Leang Bulu Bettue assemblage provides insight into the complexity and diversification of modern human culture during a key period in the global dispersal of our species. It also shows that early inhabitants of Sulawesi fashioned ornaments from body parts of endemic animals, suggesting modern humans integrated exotic faunas and other novel resources into their symbolic world as they colonized the biogeographically unique regions southeast of continental Eurasia.
Assuntos
Arte/história , Fósseis , Comportamento Social , Simbolismo , Arqueologia , História Antiga , Atividades Humanas , Migração Humana , Humanos , IndonésiaRESUMO
The Cook Islands are considered the "gateway" for human colonization of East Polynesia, the final chapter of Oceanic settlement and the last major region occupied on Earth. Indeed, East Polynesia witnessed the culmination of the greatest maritime migration in human history. Perennial debates have critiqued whether Oceanic settlement was purposeful or accidental, the timing and pathways of colonization, and the nature and extent of postcolonization voyaging-essential for small founding groups securing a lifeline between parent and daughter communities. Centering on the well-dated Tangatatau rockshelter, Mangaia, Southern Cook Islands, we charted the temporal duration and geographic spread of exotic stone adze materials-essential woodworking tools found throughout Polynesia- imported for more than 300 y beginning in the early AD 1300s. Using a technique requiring only 200 mg of sample for the geochemical analysis of trace elements and isotopes of fine-grained basalt adzes, we assigned all artifacts to an island or archipelago of origin. Adze material was identified from the chiefly complex on the Austral Islands, from the major adze quarry complex on Tutuila (Samoa), and from the Marquesas Islands more than 2,400 km distant. This interaction is the only dated example of down-the-line exchange in central East Polynesia where intermediate groups transferred commodities attesting to the interconnectedness and complexity of social relations fostered during postsettlement voyaging. For the Cook Islands, this exchange may have lasted into the 1600s, at least a century later than other East Polynesian archipelagos, suggesting that interarchipelago interaction contributed to the later development of social hierarchies.
Assuntos
Migração Humana , Metais/análise , Silicatos/química , Arqueologia , Neodímio , Polinésia , Isótopos de EstrôncioRESUMO
Seasonal two-way migration is an ecological phenomenon observed in a wide range of large-bodied placental mammals, but is conspicuously absent in all modern marsupials. Most extant marsupials are typically smaller in body size in comparison to their migratory placental cousins, possibly limiting their potential to undertake long-distance seasonal migrations. But what about earlier, now-extinct giant marsupial megafauna? Here we present new geochemical analyses which show that the largest of the extinct marsupial herbivores, the enormous wombat-like Diprotodon optatum, undertook seasonal, two-way latitudinal migration in eastern Sahul (Pleistocene Australia-New Guinea). Our data infer that this giant marsupial had the potential to perform round-trip journeys of as much as 200 km annually, which is reminiscent of modern East African mammal migrations. These findings provide, to our knowledge, the first evidence for repetitive seasonal migration in any metatherian (including marsupials), living or extinct, and point to an ecological phenomenon absent from the continent since the Late Pleistocene.
Assuntos
Migração Animal , Marsupiais , Estações do Ano , Animais , Austrália , Fósseis , Nova GuinéRESUMO
As the frequency and intensity of coral mortality events increase under climate change, understanding how declines in coral cover may affect the bioerosion of reef frameworks is of increasing importance. Here, we explore decadal-scale rates of bioerosion of the framework building coral Orbicella annularis by grazing parrotfish following the 1997/1998 El Niño-related mass mortality event at Long Cay, Belize. Using high-precision U-Th dating and CT scan analysis, we quantified in situ rates of external bioerosion over a 13-year period (1998-2011). Based upon the error-weighted average U-Th age of dead O. annularis skeletons, we estimate the average external bioerosion between 1998 and 2011 as 0.92 ± 0.55 cm depth. Empirical observations of herbivore foraging, and a nonlinear numerical response of parrotfish to an increase in food availability, were used to create a model of external bioerosion at Long Cay. Model estimates of external bioerosion were in close agreement with U-Th estimates (0.85 ± 0.09 cm). The model was then used to quantify how rates of external bioerosion changed across a gradient of coral mortality (i.e., from few corals experiencing mortality following coral bleaching to complete mortality). Our results indicate that external bioerosion is remarkably robust to declines in coral cover, with no significant relationship predicted between the rate of external bioerosion and the proportion of O. annularis that died in the 1998 bleaching event. The outcome was robust because the reduction in grazing intensity that follows coral mortality was compensated for by a positive numerical response of parrotfish to an increase in food availability. Our model estimates further indicate that for an O. annularis-dominated reef to maintain a positive state of reef accretion, a necessity for sustained ecosystem function, live cover of O. annularis must not drop below a ~5-10% threshold of cover.
Assuntos
Antozoários/fisiologia , Mudança Climática , Recifes de Corais , El Niño Oscilação Sul , Herbivoria , Perciformes/fisiologia , Animais , Belize , Modelos BiológicosRESUMO
INTRODUCTION: The commonly used clinical indicators are not sensitive and comprehensive enough to evaluate the early staging of chronic kidney disease (CKD). This study aimed to evaluate the differences in arterial spin labeling (ASL) and blood oxygenation level-dependent functional magnetic resonance imaging (BOLD-MRI) parameter values among patients at various stages of chronic kidney disease and healthy individuals. METHODS: Electronic databases PubMed, Web of Science, Cochrane, and Embase were searched from inception to March 29, 2024, to identify relevant studies on ASL and BOLD in CKD. The renal blood flow (RBF) and apparent relaxation rate (R2*) values were obtained from healthy individuals and patients with various stages of CKD. The meta-analysis was conducted using STATA version 12.0. The random-effects model was used to obtain estimates of the effects, and the results were expressed as 95% confidence intervals (CIs) and mean differences (MDs) of continuous variables. RESULTS: A total of 18 published studies were included in this meta-analysis. The cortical RBF and R2* values and medulla RBF values were considerably distinct between patients with various stages of CKD and healthy controls (MD, - 78.162; 95% CI, - 85.103 to - 71.221; MD, 2.440; 95% CI, 1.843 to 3.037; and MD, - 36.787; 95% CI, - 47.107 to - 26.468, respectively). No obvious difference in medulla R2* values was noted between patients with various stages of CKD and healthy controls (MD, - 1.475; 95% CI, - 4.646 to 1.696). CONCLUSION: ASL and BOLD may provide complementary and distinct information regarding renal function and could potentially be used together to gain a more comprehensive understanding of renal physiology.
Assuntos
Imageamento por Ressonância Magnética , Insuficiência Renal Crônica , Índice de Gravidade de Doença , Humanos , Insuficiência Renal Crônica/fisiopatologia , Insuficiência Renal Crônica/diagnóstico por imagem , Imageamento por Ressonância Magnética/métodosRESUMO
Studies of climate variation commonly rely on chemical and isotopic changes recorded in sequentially produced growth layers, such as in corals, shells, and tree rings, as well as in accretionary deposits-ice and sediment cores, and speleothems. Oxygen isotopic compositions (δ18O) of tooth enamel are a direct method of reconstructing environmental variation experienced by an individual animal. Here, we utilize long-forming orangutan dentitions (Pongo spp.) to probe recent and ancient rainfall trends on a weekly basis over ~3-11 years per individual. We first demonstrate the lack of any consistent isotopic enrichment effect during exclusive nursing, supporting the use of primate first molar teeth as environmental proxies. Comparisons of δ18O values (n=2016) in twelve molars from six modern Bornean and Sumatran orangutans reveal a high degree of overlap, with more consistent annual and bimodal rainfall patterns in the Sumatran individuals. Comparisons with fossil orangutan δ18O values (n=955 measurements from six molars) reveal similarities between modern and late Pleistocene fossil Sumatran individuals, but differences between modern and late Pleistocene/early Holocene Bornean orangutans. These suggest drier and more open environments with reduced monsoon intensity during this earlier period in northern Borneo, consistent with other Niah Caves studies and long-term speleothem δ18O records in the broader region. This approach can be extended to test hypotheses about the paleoenvironments that early humans encountered in southeast Asia.
When an animal drinks water, two naturally occurring variants of oxygen known as oxygen-18 and oxygen-16 are incorporated into its growing teeth. The ratio of these variants in water changes with temperature, rainfall and other environmental conditions and therefore can provide a record of the climate during an animal's life. Teeth tend to be well preserved as fossils, which makes it possible to gain insights into this climate record even millions of years after an animal's death. Orangutans are highly endangered great apes that today live in rainforests on the islands of Borneo and Sumatra. During a period of time known as the Pleistocene (around 2.6 million years to 12,000 years ago), these apes were more widely spread across Southeast Asia. Climate records from this area in the time before human-induced climate change are somewhat limited. Therefore, fossilized orangutan teeth offer a possible way to investigate past seasonal rainfall patterns and gain insight into the kind of environments early humans would have encountered. To address this question, Smith et al. measured oxygen-18 and oxygen-16 variants in thin slices of modern-day orangutan teeth using a specialized analytical system. This established that the teeth showed seasonal patterns consistent with recent rainfall trends, and that the ratio of these oxygen variants did not appear to be impacted by milk intake in young orangutans. These findings indicated that the oxygen variants could be a useful proxy for predicting prehistoric weather patterns from orangutan teeth. Further measurements of teeth from fossilized Sumatran orangutans showed broadly similar rainfall patterns to those of teeth from modern-day orangutans. On the other hand, fossilized teeth from Borneo suggested that the environment used to be drier, with less intense wet seasons. The approach developed by Smith et al. provides an opportunity for scientists to leverage new fossil discoveries as well as existing collections to investigate past environments. This could allow future research into how climate variation may have influenced the spread of early humans through the region, as well as the evolution of orangutans and other endangered animals.
Assuntos
Hominidae , Pongo abelii , Dente , Animais , Humanos , Pongo pygmaeus , Sudeste AsiáticoRESUMO
Childhood lead exposure has been linked to severe adverse health outcomes throughout life. Measurements of lead in teeth have established that individuals living in contaminated environments show higher levels compared to individuals living further away, although less is known about when individuals are most susceptible to these exposures. We examined lead (Pb208) concentrations (ppm) in teeth over the first 2.5 years of life in 16 children born in the late 19th to early 20th century throughout Romania. This period of intense industrialization was characterized by increases in mining, coal burning, and oil refining-activities that contaminate air, water, and food with Pb. We hypothesized the distance from an operational mine or oil refinery, or being born in a city, would be positively associated with cumulative dentine Pb exposure (CDPE). We also predicted that Pb exposures would peak in the first six months of life when gastrointestinal (GI) absorption of Pb is likely highest. Laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) of sectioned tooth dentine followed by Bayesian statistical analyses revealed that living 30 km or more from a mine or oil refinery did not explain CDPE. However, being born in a city explained 42% of CDPE. All individuals showed maximum Pb exposures after six months of age, likely due to contaminated solid food and/or non-milk liquids. This research demonstrates how tooth formation can be coupled with comprehensive elemental mapping to analyse the context and timing of early-life neurotoxicant exposures, which may be extended to well-preserved teeth from clinical and historic populations.
RESUMO
The inshore reefs of the Great Barrier Reef (GBR) have undergone significant declines in water quality following European settlement (approx. 1870 AD). However, direct evidence of impacts on coral assemblages is limited by a lack of historical baselines prior to the onset of modern monitoring programmes in the early 1980s. Through palaeoecological reconstructions, we report a previously undocumented historical collapse of Acropora assemblages at Pelorus Island (central GBR). High-precision U-series dating of dead Acropora fragments indicates that this collapse occurred between 1920 and 1955, with few dates obtained after 1980. Prior to this event, our results indicate remarkable long-term stability in coral community structure over centennial scales. We suggest that chronic increases in sediment flux and nutrient loading following European settlement acted as the ultimate cause for the lack of recovery of Acropora assemblages following a series of acute disturbance events (SST anomalies, cyclones and flood events). Evidence for major degradation in reef condition owing to human impacts prior to modern ecological surveys indicates that current monitoring of inshore reefs on the GBR may be predicated on a significantly shifted baseline.
Assuntos
Antozoários/fisiologia , Recifes de Corais , Atividades Humanas , Poluentes Químicos da Água/toxicidade , Animais , Monitoramento Ambiental , Sedimentos Geológicos/análise , Humanos , Dinâmica Populacional , Queensland , Movimentos da ÁguaRESUMO
Most researchers believe that anatomically modern humans (AMH) first appeared in Africa 160-190 ka ago, and would not have reached eastern Asia until â¼50 ka ago. However, the credibility of these scenarios might have been compromised by a largely inaccurate and compressed chronological framework previously established for hominin fossils found in China. Recently there has been a growing body of evidence indicating the possible presence of AMH in eastern Asia ca. 100 ka ago or even earlier. Here we report high-precision mass spectrometric U-series dating of intercalated flowstone samples from Huanglong Cave, a recently discovered Late Pleistocene hominin site in northern Hubei Province, central China. Systematic excavations there have led to the in situ discovery of seven hominin teeth and dozens of stone and bone artifacts. The U-series dates on localized thin flowstone formations bracket the hominin specimens between 81 and 101 ka, currently the most narrow time span for all AMH beyond 45 ka in China, if the assignment of the hominin teeth to modern Homo sapiens holds. Alternatively this study provides further evidence for the early presence of an AMH morphology in China, through either independent evolution of local archaic populations or their assimilation with incoming AMH. Along with recent dating results for hominin samples from Homo erectus to AMH, a new extended and continuous timeline for Chinese hominin fossils is taking shape, which warrants a reconstruction of human evolution, especially the origins of modern humans in eastern Asia.
Assuntos
Evolução Biológica , Cavernas/química , Fósseis , Sedimentos Geológicos/química , China , Cronologia como Assunto , Humanos , Espectrometria de Massas , Datação Radiométrica , Dente/química , Urânio/químicaRESUMO
Nine isolated fossil Pongo teeth from two cave sites in Peninsular Malaysia are reported. These are the first fossil Pongo specimens recorded in Peninsular Malaysia and represent significant southward extensions of the ancient Southeast Asian continental range of fossil Pongo during two key periods of the Quaternary. These new records from Peninsular Malaysia show that ancestral Pongo successfully passed the major biogeographical divide between mainland continental Southeast Asia and the Sunda subregion before 500 ka (thousand years ago). If the presence of Pongo remains in fossil assemblages indicates prevailing forest habitat, then the persistence of Pongo at Batu Caves until 60 ka implies that during the Last Glacial Phase sufficient forest cover persisted in the west coast plain of what is now Peninsular Malaysia at least ten millennia after a presumed corridor of desiccation had extended to central and east Java. Ultimately, environmental conditions of the peninsula during the Last Glacial Maximum evidently became inhospitable for Pongo, causing local extinction. Following post-glacial climatic amelioration and reforestation, a renewed sea barrier prevented re-colonization from the rainforest refugium in Sumatra, accounting for the present day absence of Pongo in apparently hospitable lowland evergreen rainforest of Peninsular Malaysia. The new teeth provide further evidence that Pongo did not undergo a consistent trend toward dental size reduction over time.
Assuntos
Distribuição Animal , Meio Ambiente , Pongo/fisiologia , Animais , Fósseis , Malásia , Paleontologia , Pongo/anatomia & histologia , Pongo/classificação , Dente/anatomia & histologiaRESUMO
OBJECTIVE: To study the value of a combination of vinorelbine and cisplatin (NP) as second-line neoadjuvant chemotherapy regimen for primary breast cancer. METHODS: Primary breast cancer patients on neoadjuvant chemotherapy and non-responsive to anthracyclines plus taxanes received the NP regimen. The clinical objective response was evaluated with dynamic contrast-enhanced magnetic resonance imaging (MRI) according to RECIST 1.1 before operation. The pathological response was evaluated by the Miller-Payne grading system. And the toxicities were observed and evaluated according to National Cancer Institute-Common Terminology Criteria Version 3.0 (NCI-CTC v3.0). RESULTS: A total of 33 breast cancer patients were examined. The outcomes were complete remission (CR, n = 0, 0%), partial remission (PR, n = 16, 48.5%), stable disease (n = 17, 51.5%) and progressive disease (n = 0, 0%). The clinical responsive rate (CR + PR) rate was 48.5%. The pathological response rates were G1 (n = 6, 18.2%), G2 (n = 6, 18.2%), G3 (n = 10, 30.3%), G4 (n = 9, 27.2%) and G5 (n = 2, 6.1%). And the pathological response (G3+G4+G5) was found in 21 cases (63.6%). The most common toxicities included neutropenia and nausea/vomiting. No serious toxicities were observed. CONCLUSION: As a well-tolerated and effective regimen, NP regimen may be recommended as an option of second-line neoadjuvant chemotherapy regimen for primary breast cancer.