Localised population collapse of the invasive brown alga, Undaria pinnatifida: Twenty years of monitoring on Wellington's south coast

<p>Invasive species pose a significant threat to marine environments around the world. Monitoring and research of invasive species is needed to provide direction for management programmes. This thesis is a continuation of research conducted on the invasive alga Undaria pinnatifida following its discovery on Wellington’s south coast in 1997. By compiling the results from previous monitoring surveys (1997-2000 and 2008) and carrying out additional seasonal surveys in 2018, I investigate the distribution and spread of U. pinnatifida on Wellington’s south coast, how this may have changed over time and what impacts it may have had on native macroalgal and invertebrate grazer communities. Intertidal macroalgal composition and U. pinnatifida abundance was recorded on fifteen occasions between 1997 and 2018 at two sites at Island Bay and two sites at Owhiro Bay. In addition, the subtidal abundance of six invertebrate grazers was recorded eight times within the same sampling period. Microtopography was also measured at each site to determine if topography had an influence on macroalgal composition. From 1997 to 2000 U. pinnatifida abundance gradually increased per year, but its spread remained localised to Island Bay. In 2008 U. pinnatifida had spread westward to Owhiro Bay where it was highly abundant. However, in 2018 no U. pinnatifida was recorded at any of the sites indicating a collapse of the invasion front. Further investigation revealed that U. pinnatifida was still present along the south coast with the nearest population only 500 m away from the nearest study site. The cause of the U. pinnatifida collapse is not known for certain, but it is unlikely that biotic resistance in the form of competitive exclusion or grazing or a change in environmental parameters such as temperature or nutrient concentration were contributing factors. It is speculated that the collapse arose from a multitude of confounding effects of which further research is needed to identify the exact cause. U. pinnatifida had no impact on macroalgal or grazer community composition. Additionally, microtopography also had no significant impact on macroalgal composition. This study reports the first ever invasion front collapse of U. pinnatifida in the world, and as a result, provides a new insight on U. pinnatifida distribution and invasion ecology. These findings can assist in predicting the future spread of U. pinnatifida populations as well as aid in formulation of new management strategies.</p>

Localised population collapse of the invasive brown alga, Undaria pinnatifida: Twenty years of monitoring on Wellington's south coast

<p>Invasive species pose a significant threat to marine environments around the world. Monitoring and research of invasive species is needed to provide direction for management programmes. This thesis is a continuation of research conducted on the invasive alga Undaria pinnatifida following its discovery on Wellington’s south coast in 1997. By compiling the results from previous monitoring surveys (1997-2000 and 2008) and carrying out additional seasonal surveys in 2018, I investigate the distribution and spread of U. pinnatifida on Wellington’s south coast, how this may have changed over time and what impacts it may have had on native macroalgal and invertebrate grazer communities. Intertidal macroalgal composition and U. pinnatifida abundance was recorded on fifteen occasions between 1997 and 2018 at two sites at Island Bay and two sites at Owhiro Bay. In addition, the subtidal abundance of six invertebrate grazers was recorded eight times within the same sampling period. Microtopography was also measured at each site to determine if topography had an influence on macroalgal composition. From 1997 to 2000 U. pinnatifida abundance gradually increased per year, but its spread remained localised to Island Bay. In 2008 U. pinnatifida had spread westward to Owhiro Bay where it was highly abundant. However, in 2018 no U. pinnatifida was recorded at any of the sites indicating a collapse of the invasion front. Further investigation revealed that U. pinnatifida was still present along the south coast with the nearest population only 500 m away from the nearest study site. The cause of the U. pinnatifida collapse is not known for certain, but it is unlikely that biotic resistance in the form of competitive exclusion or grazing or a change in environmental parameters such as temperature or nutrient concentration were contributing factors. It is speculated that the collapse arose from a multitude of confounding effects of which further research is needed to identify the exact cause. U. pinnatifida had no impact on macroalgal or grazer community composition. Additionally, microtopography also had no significant impact on macroalgal composition. This study reports the first ever invasion front collapse of U. pinnatifida in the world, and as a result, provides a new insight on U. pinnatifida distribution and invasion ecology. These findings can assist in predicting the future spread of U. pinnatifida populations as well as aid in formulation of new management strategies.</p>

Labortory and Pilot Tests of Enhanced Oil Recovery through Wettability Alteration by Diluted Microemulsions

Replacing oil from small pores of tight oil-wet rocks relies on altering the rock wettability with the injected fracturing fluid. Among different types of wettability-alteration surfactants, the liquid nanofluid has less adsorption loss during transport in the porous media, and can efficiently alter the rock wettability; meanwhile, it can also maintain a certain oil-water interfacial tension driving the water imbibition. In the previous study, the main properties of a Nonionic nanofluid-diluted microemulsion (DME) were evaluated, and the dispersion coefficient and adsorption rate of DME in tight rock under different conditions were quantified. In this study, to more intuitively show the change of wettability of DME to oil-wet rocks in the process of core flooding experiments and the changes of the water invasion front, CT is used to carry out on-line core flooding experiments, scan and calculate the water saturation in time, and compare it with the pressure drop in this process. Besides, the heterogeneity of rock samples is quantified in this paper. The results show that when the DME is used as the fracturing fluid additive, fingering of the water phase is observed at the beginning of the invasion; compared with brine, the fracturing fluid with DME has deeper invasion depth at the same time; the water invasion front gradually becomes uniform when the DME alters the rock wettability and triggers the imbibition; for tight rocks, DME can enter deeper pores and replace more oil because of its dominance. Finally, the selected nanofluids of DME were tested in two horizontal wells in the field, and their flowback fluids were collected and analyzed. The results show that the average droplet size of the flowback fluids in the wells using DME decreases with production time, and the altered wetting ability gradually returns to the level of the injected fracturing fluid. It can be confirmed that DME can migrate within the tight rock, make the rock surface more water-wet and enhance the imbibition capacity of the fracturing fluid, to reduce the reservoir pressure decline rate and increase production.

Neoadjuvant/Perioperative Treatment Affects Spatial Distribution and Densities of Tumor Associated Neutrophils and CD8+ Lymphocytes in Gastric Cancer

Tumor associated neutrophils (TANs) and cytotoxic T cells (CTLs) are part of the tumor microenvironment of gastric cancer (GC). We explored their tumor biological significance in neoadjuvantly/perioperatively treated GC. Immunostaining was performed on whole tissue sections of 173 GCs, using antibodies directed against myeloperoxidase (MPO) and CD8. Stained specimens were digitalized, and the densities of TANs and CTLs were assessed separately in the mucosa, tumor surface, tumor center, invasion front, and tumor scar. The densities were correlated with clinicopathological patient characteristics. Compared with a historical cohort of 449 treatment naive GCs, the TAN density in the invasion front was significantly lower in neoadjuvantly/perioperatively treated GCs. TAN density in the tumor center and invasion front correlated with tumor regression. TAN density also correlated with CTL density in the tumor center and invasion front. A high density of CTL in the tumor center correlated with an improved overall survival and tumor specific survival. We show that neoadjuvant/perioperative (radio-) chemotherapy impacts on the immune microenvironment of GC, while also depending on sex. The density of TANs in neoadjuvantly/perioperatively treated GCs differed from findings made in a treatment naive GC cohort.

From a Long-distance Threat to the Invasion Front: Invasive Aedes Mosquito Species in Belgium Between 2007 and 2020

Background: Invasive mosquito species (IMS) and their associated mosquito-borne diseases are emerging in Europe. In Belgium, the first detection of Aedes albopictus occurred in 2000 and of Aedes japonicus in 2002. Early detection and control of these IMS at points of entry (PoE’s) are of paramount importance to slow down any possible establishment. This paper gives an account of the IMS surveillance in Belgium between 2007 and 2020 and reviews the introductions and establishments recorded in that period.Methods: In total 52 PoE’s were monitored at least once for the presence of IMS between 2007 and 2020. These included used tyre and lucky bamboo import companies, airports, ports, parking lots along highways, shelters for imported cutting plants, wholesale markets, industrial areas, recycling areas, and cemeteries and an allotment garden at the country border with colonised areas. In general, monitoring was performed between April and November. Mosquitoes were captured with adult and oviposition traps, as well as by larval sampling. A logistic regression was performed to investigate the percentage of positive PoE’s for Ae. albopictus over the years. Results: Aedes albopictus has been detected at ten PoE’s, Ae. japonicus at three PoE’s and Aedes koreicus at two PoE’s. The latter two species have established overwintering populations. The percentage of PoE’s positive for Ae. albopictus increased significantly over time. Aedes albopictus is currently entering Belgium through lucky bamboo trade, used tyre trade and passive ground transport, while Ae. japonicus only through the latter two pathways. In Belgium, the import through passive ground transport was first recorded in 2018 and its importance seems to grow.Conclusion: Belgium is currently at the invasion front of Ae. albopictus and Ae. japonicus. The surveillance and control management actions at well-known PoE‘s associated to long-distance introductions are more straightforward than at less-defined PoE’s associated with short-distance introductions from colonised areas. These latter PoE’s represent a new challenge for IMS management in Belgium in the coming years and stresses the urgence of implementing a sustainable, structured and long-term IMS management programme, integrating active and passive surveillance and control.

917 Immune landscape at the invasion front of surgically resected oral squamous cell carcinomas shows significant associations with disease specific survival

BackgroundOral squamous cell carcinomas (OSCC) prognosis remains poor. While AJCC TNM 8th edition has slightly improved patients‘ stratification with regard to prognostic, innovative approaches to are still needed. As in other tumor types, tumor immune microenvironment (TiME) might represent an opportunity to improve prognostic assessment.MethodsTiME landscape of 47 HPV-negative OSCC was analyzed using multiplex immunofluorescence (mIF). Markers for tumor cells (PanCK), tumor infiltrating lymphocytes (CD3, CD8), macrophages (CD68), inhibitory (PD-1, PD-L1, TIM3, LAG3, VISTA) or stimulatory (OX40, ICOS) immune checkpoints (ICP) were studied. Regions of interest (ROI), 5 in the tumor core and 5 at the invasion front, were subjected to cell markers identification and quantification (scoring) as well as tissue compartmentalization to divide them in tumor-epithelial and tumor-stroma compartments, respectively. A total of 20 cell phenotypes were defined based on previous work (CK+, CK+PD-L1+, CD3+, CD3+CD8+, CD3+PD-1+, CD3+CD8+PD-1+, CD3+PD-L1+, CD3+CD8+PD-L1+, CD3+PD-L1+PD-1+, CD3+CD8+PD-L1+PD-1+, CD68+, CD68+PD-L1+, CK+OX40+, CD3+VISTA+, CD3+ICOS+, CD3+LAG3+, CD3+OX-40+, CD3+TIM3+). Results were correlated with clinical features including disease-specific survival (DSS) using the Kaplan-Meier method and a multivariate Cox model. A multivariate general linear model (GLM) was built to test the specific association of each variable with a given cell density by correcting the possible confusion due to other variables.ResultsImmune cells densities were significantly higher overall in the stroma. The intra-tumor stroma showed a significant enrichment of in CD3+PD-1+ T cells compared to peri-tumor stroma. None of the clinical or pathological (resection margin, tumor stage, lymph node invasion, perineural invasion) was significantly associated with DSS. In contrast, the following cell phenotypes in the tumor invasion front were strongly associated with a poor DSS, including CD3+PD-L1+ (P-value= 0.004), CD3+PD1+PD-L1+ (P-value= 0.02) and CD3+OX40+ (P-value= 0.02) T cells as well as CD3+CD8+PD-1+ (P-value= 0.048), CD3+CD8+PD-L1+ (P-value= 0.008) and CD3+CD8+PD1+PD-L1+ (P-value= 0.01) cytotoxic T cells. In the tumor core, CD68+PD-L1- macrophages (P-value= 0.06) were marginally associated with better DSS. Using a GLM, we found that tumor from smoker-drinker patients and/or with pN+, were significantly more infiltrated by PD-1- and/or PD-L1-positive immune cells. On the other hand, floor of mouth and gingiva-mandibular OSCC were significantly less infiltrated than others.ConclusionsThe prognostic value of PD-1+ and/or PD-L1+ cells in the invasion front of resected OSCC was remarkable, underlying the importance of this area when studying the TiME. Incorporating TiME analysis in the invasion front may improve prognostic evaluation of patients treated for OSCC, especially in the context of immunotherapy.AcknowledgementsThis study was supported by a strategic alliance between the Translational Molecular Pathology-Immunoprofiling las (TMP-IL) at the Department Translational Molecular Pathology, the University of Texas MD Anderson Cancer Center and the Université Claude Bernard Lyon, Centre de Recherche en Cancérologie de Lyon and the Department of Translational Medicine, Centre Léon Bérard, Lyon, France. The authors would acknowledge ITMO Cancer 2020, ”Formation à la Recherche Fondamentale et Translationnelle en Cancérologie” (JB); CLARA 2020 ”Soutien à la mobilité des jeunes chercheurs en oncologie, N° CVPPRCAN000198” (JB); Fondation de France 2020 ”Aide à la mobilité international de médecins et pharmaciens, N° 00112162” (JB); Ligue contre le cancer 2021, comité de Saône-et-Loire (PS); 2017-INCa-DGOS-Inserm_12563: INCa SIRIC-LYriCAN INCa-DGOS-Inserm_12563 (PS)Ethics ApprovalThe study was conducted in accordance with all applicable laws, rules, and requests of French and European government authorities. Written informed consent was obtained from all patients and the study was approved by the Centre Leon Bérard institutional review board (Lyon, France). Samples were obtained from the CRB Centre Léon Bérard (n°BB-0033-00050) which is quality certified according NFS96-900 French standard and ISO 9001 for clinical trials.ConsentWritten informed consent was obtained from all patients and the study was approved by the Centre Leon Bérard institutional review board (Lyon, France)

Stroma AReactive Invasion Front Areas (SARIFA)—A New Easily to Determine Biomarker in Colon Cancer—Results of a Retrospective Study

Many studies have used histomorphological features to more precisely predict the prognosis of patients with colon cancer, focusing on tumor budding, poorly differentiated clusters, and the tumor–stroma ratio. Here, we introduce SARIFA: Stroma AReactive Invasion Front Area(s). We defined SARIFA as the direct contact between a tumor gland/tumor cell cluster (≥5 cells) and inconspicuous surrounding adipose tissue in the invasion front. In this retrospective, single-center study, we classified 449 adipose-infiltrative adenocarcinomas (not otherwise specified) from two groups based on SARIFA and found 25% of all tumors to be SARIFA-positive. Kappa values between the two pathologists were good/very good: 0.77 and 0.87. Patients with SARIFA-positive tumors had a significantly shorter colon-cancer-specific survival (p = 0.008, group A), absence of metastasis, and overall survival (p < 0.001, p = 0.003, group B). SARIFA was significantly associated with adverse features such as pT4 stage, lymph node metastasis, tumor budding, and higher tumor grade. Moreover, SARIFA was confirmed as an independent prognostic indicator for colon-cancer-specific survival (p = 0.011, group A). SARIFA assessment was very quick (<1 min). Because of low interobserver variability and good prognostic significance, SARIFA seems to be a promising histomorphological prognostic indicator in adipose-infiltrative adenocarcinomas of the colon. Further studies should validate our results and also determine whether SARIFA is a universal prognostic indicator in solid cancers.