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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.

Interdecadal modes of tropical Pacific ocean-atmosphere circulation have a strong influence on global temperature, yet the extent to which these phenomena influence global climate on multicentury timescales is still poorly known. Here we present a 2,000-year, multiproxy reconstruction of western Pacific hydroclimate from two speleothem records for southeastern Indonesia. The composite record shows pronounced shifts in monsoon rainfall that are antiphased with precipitation records for East Asia and the central-eastern equatorial Pacific. These meridional and zonal patterns are best explained by a poleward expansion of the Australasian Intertropical Convergence Zone and weakening of the Pacific Walker circulation (PWC) between ∼1000 and 1500 CE Conversely, an equatorward contraction of the Intertropical Convergence Zone and strengthened PWC occurred between ∼1500 and 1900 CE. Our findings, together with climate model simulations, highlight the likelihood that century-scale variations in tropical Pacific climate modes can significantly modulate radiatively forced shifts in global temperature.

Objective To discuss the application value of CT scanning technology in cause of death determination of medical dispute cases. Methods From July 2017 to December 2018, postmortem CT imaging data of 12 medical dispute cases were collected. CT imaging diagnosis results and anatomy findings as well as differences between antemortem and postmortem CT diagnosis were compared. The advantages and disadvantages of CT routine tests of the cadavers in terms of the diagnosis of disease and damage were analyzed. Results The comparison between CT imaging diagnosis and anatomical findings showed that CT scans had advantages in the diagnosis of disease and damage with large differences in density changes, such as atelectasis, pneumonia, calcification, fracture and hemorrhage, etc. The comparison of CT diagnosis in antemortem and postmortem examination showed that the cadavers of medical dispute cases were well preserved and that postmortem CT scan was meaningful for the diagnosis of antemortem diseases. Conclusion Virtual anatomy technology has a relatively high application value in postmortem examination of medical dispute cases. It can provide effective information for the appraisers before the autopsy and can also provide a reference for cause of death analysis when the anatomy cannot be performed.

Objective To study the time-dependent expression and distribution of acetylcholinesterase （AChE） during skin incised wound healing in mice, and discuss its effect in wound healing as well as the feasibility of using it as a reference index for wound age estimation. Methods A total of 45 C57BL/KsJ mice were randomly divided into one control group and eight incised groups. The skin incised wound model was established in the incised groups with samples of skin wounds taken at 6 h, 12 h, 1 d, 3 d, 5 d, 7 d, 10 d and 14 d post-injury respectively, while the uninjured skin tissue was extracted in the control group. Expression and distribution of AChE in skin samples were detected by immunohistochemistry, double immunofluorescence and Western blotting. Results Immunohistochemistry results indicated that AChE was mainly detected in infiltrating polymorphonuclear cells （PMNs） 6 to 12 h post-injury. A large number of AChE-positive mononuclear cells （MNCs） were observed 1 to 3 d post-injury. The AChE-positive cells were mainly fibroblastic cells （FBCs） 5 to 14 d post-injury. The ratio of the AChE-positive cells increased initially 6 h post-injury, and reached the peak at 1 d post-injury. Double immunofluorescent staining showed that the majority of AChE-positive MNCs and FBCs expressed macrophage marker and myofibroblast marker, respectively. Western blotting results showed that the relative expression level of AChE in the incised group was higher than that in the control group averagely, reached the peak at 1 d post-injury, then reached a second peak at 7 d post-injury. Conclusion The expression of AChE is found in PMNs, macrophages and myofibroblast during skin wound healing, which indicates it might be involved in the adjustment of inflammatory response and fibrotic repair after injury. Moreover, combined use of various methods for the detection of the expression of AChE would provide reference for skin wound age estimation.

Objective To investigate the expression changes of annexin A1 （ANXA1） during the process of skin incision healing, and to explore its expression and function during skin injury repair. Methods The skin injury model of mice was prepared, and skin tissues of the controls and the injured group at 6 h, 12 h, 1 d, 3 d, 5 d, 7 d, 10 d and 14 d after injuries were taken. The morphological changes of the wound were observed by hematoxylin-eosin （HE） staining, and the expression of ANXA1 was detected by immunohistochemistry （IHC） and Western blotting. Results HE staining showed normal healing of skin wounds. IHC results revealed that ANXA1 was expressed in the epidermis, hair follicle, sebaceous gland and vascular endothelium. In the injured group, the expression of ANXA1 was enhanced in epidermis and skin appendages around the wound 6-12 h after injury, and ANXA1 was also highly expressed in neutrophils and a small number of mononuclear cells. ANXA1 was mainly positively expressed in monocytes, neovascular endothelial cells and fibroblasts, and small amount of fibroblasts at 1-3 d, 5-10 d, and 14 d after injury, respectively. Western blotting showed that, compared with the controls, the expression of ANXA1 was significantly increased at 6 h after injury, peaked at 1 d, and then decreased gradually in the injured group. Conclusion ANXA1 may be involved in the regulation of skin damage repair, with time-dependent expression during skin wound healing, and thus is expected to be a biological marker for inferring the wound formation time.