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"Wong, George"
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Sustainable school leadership : portraits of individuality
This highly experienced team of cross-cultural researchers combine scholarly research with over a decade of extensive empirical research using an innovative \"portrait\" methodology to investigate the challenges that educational leaders on two continents currently face. The kinds of challenges explored include: the personal, such as being new to the job, coping with the role, approaching retirement; the inter-personal, including power relations, personal challenges with staff, parents and children; the local, looking at issues faced by the school in the community; the national, for example government initiatives, inspection; the global, including the impact of economic forced on political and institutional management. The authors show how the combined insights from individual portraits critique national policies and organizational functioning, and can inform leadership research by a better understanding of how links between the micro-, meso-, and macro-levels of education promote or discourage school leaders' sustainability. The authors present cross-cultural comparisons of eastern and western approaches to educational leadership, suggesting that sustainability - or lack of it - may have different roots in different cultures.
Book
A Pooled Analysis of Bone Marrow Micrometastasis in Breast Cancer
In a pooled analysis of nine clinical trials involving almost 5000 women with breast cancer who underwent examination of the bone marrow for metastatic cancer cells, the presence of metastases in the bone marrow at the time of diagnosis of breast cancer was associated with a poor prognosis.
In trials involving almost 5000 women with breast cancer, the presence of micrometastases in the bone marrow at the time of diagnosis of breast cancer was associated with a poor prognosis.
Data from experiments in animals
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performed in the 1960s and from more recent immunocytochemical
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,
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and molecular
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,
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studies suggest that lymph-node involvement does not accurately predict hematogenous dissemination of cancer cells, nor is hematogenous dissemination necessarily associated with lymph-node involvement.
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,
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During the past two decades, several studies have assessed the prevalence and prognostic value of hematogenous dissemination of tumor cells in patients with node-positive and node-negative breast cancer.
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,
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–
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The influence of the presence of micrometastasis in the bone marrow on prognosis has been shown in patients with identical stages of breast cancer, as defined by tumor . . .
Journal Article
Mass coral mortality under local amplification of 2 °C ocean warming
A 2 °C increase in global temperature above pre-industrial levels is considered a reasonable target for avoiding the most devastating impacts of anthropogenic climate change. In June 2015, sea surface temperature (SST) of the South China Sea (SCS) increased by 2 °C in response to the developing Pacific El Niño. On its own, this moderate, short-lived warming was unlikely to cause widespread damage to coral reefs in the region, and the coral reef “Bleaching Alert” alarm was not raised. However, on Dongsha Atoll, in the northern SCS, unusually weak winds created low-flow conditions that amplified the 2 °C basin-scale anomaly. Water temperatures on the reef flat, normally indistinguishable from open-ocean SST, exceeded 6 °C above normal summertime levels. Mass coral bleaching quickly ensued, killing 40% of the resident coral community in an event unprecedented in at least the past 40 years. Our findings highlight the risks of 2 °C ocean warming to coral reef ecosystems when global and local processes align to drive intense heating, with devastating consequences.
Journal Article
Time-dependent heterogeneity leads to transient suppression of the COVID-19 epidemic, not herd immunity
Epidemics generally spread through a succession of waves that reflect factors on multiple timescales. On short timescales, super-spreading events lead to burstiness and overdispersion, whereas long-term persistent heterogeneity in susceptibility is expected to lead to a reduction in both the infection peak and the herd immunity threshold (HIT). Here, we develop a general approach to encompass both timescales, including time variations in individual social activity, and demonstrate how to incorporate them phenomenologically into a wide class of epidemiological models through reparameterization. We derive a nonlinear dependence of the effective reproduction number Re on the susceptible population fraction S. We show that a state of transient collective immunity (TCI) emerges well below the HIT during early, high-paced stages of the epidemic. However, this is a fragile state that wanes over time due to changing levels of social activity, and so the infection peak is not an indication of long-lasting herd immunity: Subsequent waves may emerge due to behavioral changes in the population, driven by, for example, seasonal factors. Transient and long-term levels of heterogeneity are estimated using empirical data from the COVID-19 epidemic and from real-life face-to-face contact networks. These results suggest that the hardest hit areas, such as New York City, have achieved TCI following the first wave of the epidemic, but likely remain below the long-term HIT. Thus, in contrast to some previous claims, these regions can still experience subsequent waves.
Journal Article
Anti‑proliferative effects of Drynaria fortunei in a model for triple negative breast cancer
Triple negative breast cancer (TNBC) is characterized by the absence of hormones and growth factor receptors. It is typically responsive to anthracycline/taxol-based conventional chemotherapy. However, major therapeutic limitations include systemic toxicity and acquired resistance to chemotherapeutics. To combat this, nutritional herbs from traditional Chinese medicine (TCM) with limited reported toxicity may represent treatment alternatives for TNBC. Such herbs can effectively target multiple signaling pathways in numerous breast cancer models. The efficacy of various nutritional herbs in a cellular model of TNBC is associated with the downregulation of retinoblastoma (RB) signaling through the cyclin D-CDK4/6-RB axis. Therefore, the present study was designed to examine the effects of Drynaria fortunei (DF) in the same cellular model of TNBC to identify potential mechanistic leads for its efficacy. DF is a nutritional herb that represents a common component of herbal formulations used in TCM. The estrogen receptor-negative, progesterone receptor-negative and human epidermal growth factor receptor-2-negative MDA-MB-231 human breast carcinoma-derived cell line was used as the cellular model for TNBC in the present study. Non-fractionated aqueous extract from the bark of DF represented the test agent. Quantitative end-point biomarkers for the efficacy of DF assessed in the present study included cell cycle progression, RB signaling and caspase 3/7 activity. Treatment with DF at cytostatic concentration induced S phase cell cycle arrest and inhibited RB signaling as evidenced by the downregulated expression of cyclin E, CDK2, E2F1 and RB phosphorylation. DF treatment increased pro-apoptotic caspase 3/7 activity which was inhibited by the pan-caspase inhibitor Z-VAD-FMK. DF treatment also exhibited increased expression of cleaved ADP-ribose) polymerase-1. These data identify potential mechanistic leads for anti-proliferative and pro-apoptotic effects of DF in the present TNBC model. The present experiments validated a mechanism-driven experimental approach to identify efficacious nutritional herbs and/or their bioactive constituents as treatment alternatives for TNBC.
Journal Article
Internal waves influence the thermal and nutrient environment on a shallow coral reef
Internal waves can influence water properties in coastal ecosystems through the shoreward transport and mixing of subthermocline water into the nearshore region. In June 2014, a field experiment was conducted at Dongsha Atoll in the northern South China Sea to study the impact of internal waves on a coral reef. Instrumentation included a distributed temperature sensing system, which resolved spatially and temporally continuous temperature measurements over a 4-km cross-reef section from the lagoon to 50-m depth on the fore reef. Our observations show that during summer, internal waves shoaling on the shallow atoll regularly transport cold, nutrient-rich water shoreward, altering near-surface water properties on the fore reef. This water is transported shoreward of the reef crest by tides, breaking surface waves and wind-driven flow, where it significantly alters the water temperature and nutrient concentrations on the reef flat. We find that without internal wave forcing on the fore reef, temperatures on the reef flat could be up to 2.0°C ± 0.2°C warmer. Additionally, we estimate a change in degree heating weeks of 0.7°C-weeks warmer without internal waves, which significantly increases the probability of a more severe bleaching event occurring at Dongsha Atoll. Furthermore, using nutrient samples collected on the fore reef during the study, we estimated that instantaneous onshore nitrate flux is about four-fold higher with internal waves than without internal waves. This work highlights the importance of internal waves as a physical mechanism shaping the nearshore environment, and likely supporting resilience of the reef.
Journal Article
Impact of glacial/interglacial sea level change on the ocean nitrogen cycle
The continental shelves are themost biologically dynamic regions of the ocean, and they are extensive worldwide, especially in the western North Pacific. Their area has varied dramatically over the glacial/interglacial cycles of the last million years, but the effects of this variation on ocean biological and chemical processes remain poorly understood. Conversion of nitrate to N₂ by denitrification in sediments accounts for half or more of the removal of biologically available nitrogen (“fixed N”) from the ocean. The emergence of continental shelves during ice ages and their flooding during interglacials have been hypothesized to drive changes in sedimentary denitrification. Denitrification leads to the occurrence of phosphorus-bearing, N-depleted surface waters, which encourages N₂ fixation, the dominant N input to the ocean. An 860,000-y record of foraminifera shell-bound N isotopes from the South China Sea indicates that N₂ fixation covaried with sea level. The N₂ fixation changes are best explained as a response to changes in regional excess phosphorus supply due to sea level-driven variations in shallow sediment denitrification associated with the cyclic drowning and emergence of the continental shelves. This hypothesis is consistent with a glacial ocean that hosted globally lower rates of fixed N input and loss and a longer residence time for oceanic fixed N—a “sluggish” ocean N budget during ice ages. In addition, this work provides a clear sign of sea level-driven glacial/interglacial oscillations in biogeochemical fluxes at and near the ocean margins, with implications for coastal organisms and ecosystems.
Journal Article
Development and validation of outcome prediction models for aneurysmal subarachnoid haemorrhage: the SAHIT multinational cohort study
AbstractObjectiveTo develop and validate a set of practical prediction tools that reliably estimate the outcome of subarachnoid haemorrhage from ruptured intracranial aneurysms (SAH).DesignCohort study with logistic regression analysis to combine predictors and treatment modality.SettingSubarachnoid Haemorrhage International Trialists’ (SAHIT) data repository, including randomised clinical trials, prospective observational studies, and hospital registries.ParticipantsResearchers collaborated to pool datasets of prospective observational studies, hospital registries, and randomised clinical trials of SAH from multiple geographical regions to develop and validate clinical prediction models.Main outcome measurePredicted risk of mortality or functional outcome at three months according to score on the Glasgow outcome scale.ResultsClinical prediction models were developed with individual patient data from 10 936 patients and validated with data from 3355 patients after development of the model. In the validation cohort, a core model including patient age, premorbid hypertension, and neurological grade on admission to predict risk of functional outcome had good discrimination, with an area under the receiver operator characteristics curve (AUC) of 0.80 (95% confidence interval 0.78 to 0.82). When the core model was extended to a “neuroimaging model,” with inclusion of clot volume, aneurysm size, and location, the AUC improved to 0.81 (0.79 to 0.84). A full model that extended the neuroimaging model by including treatment modality had AUC of 0.81 (0.79 to 0.83). Discrimination was lower for a similar set of models to predict risk of mortality (AUC for full model 0.76, 0.69 to 0.82). All models showed satisfactory calibration in the validation cohort.ConclusionThe prediction models reliably estimate the outcome of patients who were managed in various settings for ruptured intracranial aneurysms that caused subarachnoid haemorrhage. The predictor items are readily derived at hospital admission. The web based SAHIT prognostic calculator (http://sahitscore.com) and the related app could be adjunctive tools to support management of patients.
Journal Article
Growth inhibitory efficacy of Cornus officinalis in a cell culture model for triple-negative breast cancer
Triple-negative breast cancer (TNBC) lacks the expressions of estrogen receptor-α, progesterone receptor and human epidermal growth factor receptor-2. The treatment options for TNBC include anthracyclin/taxol based conventional chemotherapy and small molecular inhibitor based targeted therapy. However, the therapeutic efficacy is limited by systemic toxicity and acquired tumor resistance; identification of less toxic testable alternatives is urgently required. Non-toxic nutritional herbs are commonly used in traditional Chinese herbal medicine for general health management and may additionally represent a testable therapeutic alternative for TNBC. The present study examined the growth inhibitory efficacy of the nutritional herb Cornus officinalis (CO) in MDA-MB-231 cells, which represent a cell culture model for TNBC, and identified potential mechanistic leads. In MDA-MB-231 cells, CO induced dose-dependent cytostatic growth arrest [inhibitory concentration (IC)50, 0.1% and IC90, 0.5%], and inhibited anchorage independent colony formation. Mechanistically, CO inhibited G1 to S phase transition leading to G1 arrest and decreased the expression of cyclin D1 and phosphorylated-retinoblastoma proteins. CO additionally altered apoptosis specific BCL-2 associated X protein/B-cell lymphoma-2 expression and upregulated pro-apoptotic caspase-3/7 activity. Collectively, these data provided mechanistic evidence for the efficacy of CO, and validated a mechanism-based approach to prioritize efficacious nutritional herbs as testable alternatives for secondary prevention/treatment of TNBC.
Journal Article