Sensitive Sites Research Articles

Microdosimetric analysis of monoenergetic electrons and beta-emitting radionuclides based on mesh-type cell models and RBE prediction

AimsMicrodosimetric indicators are commonly used to describe the energy deposition characteristics of ionizing radiation at the subcellular and DNA levels to predict radiation-induced biological effects. Monoenergetic electrons and beta-emitting radionuclides (β nuclides) have a certain range in low-density media, and their microdosimetric indicators in the cell nucleus are of great significance for understanding the characteristics of different types of β nuclides and the evaluation of relative biological effectiveness (RBE). MethodsMicrodosimetry in the nucleus is greatly affected by cell morphology, so in this paper, based on laser confocal tomography images of BEAS-2B and L-O2 cell lines, two types of mesh-type cell models were constructed to restore the morphological features of real cells. The Geant4-DNA toolkit was used to simulate the lineal energy and dose distribution of monoenergetic electrons (0.1 keV-1 MeV) and 5 types of beta nuclides (Cs-137, Cs-134, C-14, I-131, and H-3) in the cell nucleus with different initial energies. The effects of factors such as initial energy, sensitive site (radius = 2 nm, 10 nm, 30 nm, 300 nm), and cell type on microdosimetric quantities in the nucleus and their predictions of nuclide RBE were analysed. ResultsThe results show that for the same type of nuclide, there are different RBE values between BEAS-2B and L-O2 cells, with Cs-134 having a difference of 17.75% and H-3 having a difference of 10.58%. In addition, the mean lineal energy in the nucleus fluctuates with changes in the initial energy and sampling site radius of monoenergetic electrons, especially for low and medium energies where the sampling site radius has a significant effect. Moreover, the proximity functions of monoenergetic electrons with an initial energy below 1 keV are greatly affected by the cell shape, and those above 20 keV are greatly affected by the model volume. ConclusionsThe study confirms the necessity of using mesh cell models for microdosimetric analysis in the cell nucleus and predicting its biological effects by combining mesh models of real human cells to simulate microdosimetric indicators of monoenergetic electrons and beta-emitting nuclides. The estimation of the RBE of β nuclides achieved in this study has reference value for predicting radiobiological damage in different cell types.

New insights into hydrogen trapping and embrittlement in high strength aluminum alloys

An attractive approach to mitigate hydrogen embrittlement (HE) is to use nano-sized particles to immobilize hydrogen. However, the atomic scale relationship between different particle-matrix characteristics in aluminum alloys and the susceptibility to HE is unknown. In this study, the effects of interactions between various interfaces and hydrogen in aluminum alloys are investigated using a comprehensive multiscale experimental and simulation-based approach that includes atomic-scale observations, simulation and advanced hydrogen mapping techniques. Depending on the nature of interfaces, e.g., coherency, size, and crystal structure, some are useful for mitigating HE, others provide hydrogen to sensitive sites, and some act as crack initiation sites.

In Vivo Genotoxicity and Toxicity Assessment of Sterigmatocystin Individually and in Mixture with Aflatoxin B1.

Mycotoxins are natural food and feed contaminants produced by several molds. The primary mode of exposure in humans and animals is through mixtures. Aflatoxin B1 (AFB1) and sterigmatocystin (STER) are structurally related mycotoxins that share the same biosynthetic route. Few in vivo genotoxicity assays have been performed with STER. In the present genotoxicity study, Wistar rats were dosed orally with STER (20 mg/kg b.w.), AFB1 (0.25 mg/kg b.w.) or a mixture of both in an integrated micronucleus (bone marrow) and comet study (liver and kidney). STER was dosed at the highest feasible dose in corn oil. No increase in the percentage of micronuclei in bone marrow was observed at any condition. Slight DNA damage was detected in the livers of animals treated with AFB1 or the mixture (DNA strand breaks and Fpg (Formamidopyrimidine DNA glycosylase)-sensitive sites, respectively). Plasma, liver, and kidney samples were analyzed with LC-MS/MS demonstrating exposure to both mycotoxins. General toxicity parameters (organs absolute weight, biochemistry, and histopathology) were not altered either individually or in the mixture. The overall absence of individual genotoxicity did not allow us to set any type of interaction in the mixture. However, a possible toxicokinetic interaction was observed.

Structural basis of human Slo2.2 channel gating and modulation

The sodium-activated Slo2.2 channel is abundantly expressed in the brain, playing a critical role in regulating neuronal excitability. The Na+-binding site and the underlying mechanisms of Na+-dependent activation remain unclear. Here, we present cryoelectron microscopy (cryo-EM) structures of human Slo2.2 in closed, open, and inhibitor-bound form at resolutions of 2.6-3.2Å, revealing gating mechanisms of Slo2.2 regulation by cations and a potent inhibitor. The cytoplasmic gating ring domain of the closed Slo2.2 harbors multiple K+ and Zn2+ sites, which stabilize the channel in the closed conformation. The open Slo2.2 structure reveals at least two Na+-sensitive sites where Na+ binding induces expansion and rotation of the gating ring that opens the inner gate. Furthermore, a potent inhibitor wedges into a pocket formed by pore helix and S6 helix and blocks the pore. Together, our results provide a comprehensive structural framework for the investigation of Slo2.2 channel gating, Na+ sensation, and inhibition.

Theoretical prediction of mechanical, thermodynamic, and surface oxygen adsorption properties of anti-perovskite Ti3AC (A = Tl and Al) ceramics for thermal barrier coating materials

Based on first principles, the mechanical, thermodynamic, and surface oxygen adsorption properties of Ti3AC (A = Tl and Al) ceramics are investigated. The mechanical parameters of Ti3AlC ceramics can well reproduce other theoretical and experimental data. The negative formation enthalpy and lattice dynamics characteristics indicate that Ti3AC ceramics are thermodynamically stable. At 0 K, the mechanical strength of Ti3TlC ceramics is always smaller than that of Ti3AlC ceramics, but its ductility is better than Ti3AlC ceramics. Ti3TlC and Ti3AlC ceramics have normal thermal expansion behavior at 0–1800 K, and belong to high and medium expansion materials, respectively. The thermal expansion coefficient of Ti3TlC ceramics increases with increasing temperature. However, an important discovery is that Ti3AlC ceramics have an inhibitory thermal expansion behavior at high temperatures. At 300–1800 K, the Grüneisen constant of Ti3TlC ceramics is 1.55–1.78 and that of Ti3AlC ceramics is 1.49–1.54. At 0–1800 K, the phonon thermal conductivity of Ti3TlC is always smaller than that of Ti3AlC. At a high temperature of 1800 K, the thermal conductivity of Ti3TlC and Ti3AlC ceramics is 13.42 and 33.27 W m−1 K−1, respectively. The most sensitive adsorption site of O on Ti3TlC (100) ceramic surfaces is at the top site, while the most sensitive adsorption site on Ti3AlC (100) ceramic surfaces is at the hollow site. Moreover, the Debye temperature, melting point, and hardness of Ti3AC ceramics are also investigated.

Treatments for atopic dermatitis.

Atopic dermatitis usually develops in childhood, but can occur in adults. Management involves drug and non-drug treatments to clear the skin. Not all patients with atopic dermatitis have allergies. Most patients have trigger factors that can be avoided. All patients should use soap substitutes and bath oils. Moisturisers are important for improving the condition of the skin. Topical corticosteroids are the main drug treatment. The choice of corticosteroid depends largely on the site of the atopic dermatitis. Topical calcineurin inhibitors can be considered for sensitive sites such as the face where potent topical corticosteroids are potentially harmful. Adjunctive treatments given during flares of dermatitis include bleach baths and wet dressings. Antihistamines may help to relieve itch. Phototherapy may be considered by a specialist for adults if there is inadequate response to treatment. Severe cases of atopic dermatitis may require systemic treatment. Immunosuppressants, such as ciclosporin, have been used and now dupilumab and upadacitinib are available for severe chronic atopic dermatitis.

The effective on intradermal acupuncture based on changes in biological specificity of acupoints for major depressive disorder: study protocol of a prospective, multicenter, randomized, controlled trial

BackgroundAntidepressants still have some side effects in treating major depressive disorder (MDD), and acupuncture therapy is a complementary therapy of research interest for MDD. Acupoints are sensitive sites for disease response and stimulation points for acupuncture treatment. Prior studies suggest that the biological specificity of acupoints is altered in physiological and pathological situations. Therefore, we hypothesize that the biological specificity of acupoints is associated with the diagnosis of MDD and that stimulating acupoints with significant biological specificity can achieve a better therapeutic effect than clinical common acupoints. This study aims to investigate the efficacy and safety of intradermal acupuncture (IA) treatment for MDD based on changes in the biological specificity of acupoints.MethodsThe first part of the study will enroll 30 MDD patients and 30 healthy control (HC) participants to assess pain sensitivity and thermal specificity of MDD-related acupoints using a pressure pain threshold gauge (PTG) and infrared thermography (IRT). The potentially superior acupoints for treating MDD will be selected based on the results of PTG and IRT tests and referred to as pressure pain threshold strong response acupoints (PSA) and temperature strong response acupoints (TSA).The second part of the study will enroll 120 eligible MDD patients randomly assigned to waiting list (WL) group, clinical common acupoint (CCA) group, TSA group, and PSA group in a 1:1:1:1 ratio. The change in the Patient Health Questionnaire-9 Items (PHQ-9), the MOS item short-form health survey (SF-36), pressure pain threshold, temperature of acupoints, and adverse effects will be observed. The outcomes of PHQ-9 and SF-36 measures will be assessed before intervention, at 3 and 6 weeks after intervention, and at a 4-week follow-up. The biological specificity of acupoint measures will be assessed before intervention and at 6 weeks after intervention. All adverse effects will be assessed.DiscussionThis study will evaluate the therapeutic effect and safety of IA for MDD based on changes in the biological specificity of acupoints. It will investigate whether there is a correlation between the biological specificity of MDD-related acupoints and the diagnosis of MDD and whether stimulating strong response acupoints is superior to clinical common acupoints in the treatment of MDD. The study’s results may provide insights into the biological mechanisms of acupuncture and its potential as a complementary therapy for MDD.Clinical Trial RegistrationClinicalTrials.gov, identifier: NCT05524519.

Extraordinary pitting resistance obtained by forming a partially recrystallized microstructure in a severely deformed 316LN stainless steel

Austenitic stainless steels with Cr-containing passive films are susceptible to pitting corrosion with the presence of aggressive anions. Repeated cold rolling and subsequent annealing were adopted to enhance the pitting resistance of a 316LN austenite stainless steel by balancing the deformed and the recrystallized microstructure. The highly ultra-fine grained structure formed during cold rolling gradually evolved to partially or fully recrystallized structures depending on the annealing parameters. Their microstructures were characterized by EBSD and the corrosion behaviors were evaluated through electrochemical techniques in a typical 3.5 wt% NaCl solution. The results show that the short-time annealed sample with a partially recrystallized structure exhibits extraordinary corrosion resistance compared with the cold rolled or the fully recrystallized one. This might be attributed to the elimination of the corrosion sensitive sites introduced during cold rolling by a proper extent of recrystallization without too many annealing twins, which are beneficial for pit nucleation.

Acceptable intakes (AIs) for 11 small molecule N-nitrosamines (NAs)

Low levels of N-nitrosamines (NAs) were detected in pharmaceuticals and, as a result, health authorities (HAs) have published acceptable intakes (AIs) in pharmaceuticals to limit potential carcinogenic risk. The rationales behind the AIs have not been provided to understand the process for selecting a TD50 or read-across analog. In this manuscript we evaluated the toxicity data for eleven common NAs in a comprehensive and transparent process consistent with ICH M7. This evaluation included substances which had datasets that were robust, limited but sufficient, and substances with insufficient experimental animal carcinogenicity data. In the case of robust or limited but sufficient carcinogenicity information, AIs were calculated based on published or derived TD50s from the most sensitive organ site. In the case of insufficient carcinogenicity information, available carcinogenicity data and structure activity relationships (SARs) were applied to categorical-based AIs of 1500 ng/day, 150 ng/day or 18 ng/day; however additional data (such as biological or additional computational modelling) could inform an alternative AI. This approach advances the methodology used to derive AIs for NAs.

Corrosion Behavior of TiMoNbX (X = Ta, Cr, Zr) Refractory High Entropy Alloy Coating Prepared by Laser Cladding Based on TC4 Titanium Alloy.

TiMoNbX (X = Cr, Ta, Zr) RHEA coatings were fabricated on TC4 titanium alloy substrate using laser cladding technology. The microstructure and corrosion resistance of the RHEA were studied by XRD, SEM and an electrochemical workstation. The results show that the TiMoNb series RHEA coating was composed of a columnar dendrite (BCC) phase, a rod-like second phase, a needle-like structure and equiaxed dendrite, but the TiMoNbZr RHEA coating showed high-density defects, similar to those in TC4 titanium alloy, which were composed of small non-equiaxed dendrites and lamellar α'(Ti). In the 3.5% NaCl solution, compared with TC4 titanium alloy, the RHEA had a lower corrosion sensitivity and fewer corrosion sites, showing better corrosion resistance. The corrosion resistance of the RHEA ranged from strong to weak in this order: TiMoNbCr, TiMoNbZr, TiMoNbTa and TC4. The reason is that the electronegativity of different elements is different, and the speeds of the formation of the passivation film were very different. In addition, the positions of pores appearing in the laser cladding process also affected the corrosion resistance.

National utilization and reimbursement patterns for Mohs micrographic surgery in the ambulatory surgery setting

Skin cancer is the most common type of cancer in the US, with certain health behaviors and demographics increasing an individual’s lifetime risk. 1 Guy G.P.J. Machlin S.R. Ekwueme D.U. Yabroff K.R. Prevalence and costs of skin cancer treatment in the U.S., 2002-2006 and 2007-2011. Am J Prev Med. 2015; 48: 183-187https://doi.org/10.1016/j.amepre.2014.08.036 Abstract Full Text Full Text PDF PubMed Scopus (537) Google Scholar , 2 Singer S. Tkachenko E. Yeung H. Mostaghimi A. Skin cancer and skin cancer risk behaviors among sexual and gender minority populations: A systematic review. J Am Acad Dermatol. 2020; 83: 511-522https://doi.org/10.1016/j.jaad.2020.02.013 Abstract Full Text Full Text PDF Scopus (11) Google Scholar Many skin cancers on cosmetically and functionally sensitive sites can be treated with Mohs micrographic surgery (MMS). These procedures primarily take place in the outpatient setting with either immediate or delayed repair of the resulting defect. In prior studies, characteristics such as insurance status among patients undergoing MMS have been described but these data are limited by small sample sizes from few institutions. 3 Clarke E.L. Willenbrink T.J. Shelton M. et al. Association of Tumor Characteristics With Insurance Type Among Patients Undergoing Mohs Micrographic Surgery for Nonmelanoma Skin Cancer. JAMA Dermatol. 2022; 158: 919-922https://doi.org/10.1001/jamadermatol.2022.1802 Crossref Scopus (0) Google Scholar The objective of this study was to assess patient demographics, spending, and reimbursement trends for MMS in hospital-owned facilities and offices using nationally representative data.

Integration of Multicriteria Decision Analysis and GIS for Evaluating the Site Suitability for the Landfill in Hargeisa City and Its Environs, Somaliland

Poor waste management and illegal waste shipments adversely affect the environment and public health, resulting in environmental degradation. Indeed, environmental degradation is one of the most visible problems in Hargeisa. Currently, solid waste is disposed of at two dumping sites within the city limits, causing problematic and unsanitary conditions. Moreover, the existing dumpsites are on the verge of closure, highlighting an important need that must be addressed. This research aimed to integrate multicriteria decision analysis and GIS to evaluate the site suitability for landfill in Hargeisa, Somaliland. For this purpose, eleven significant parameters were selected: proximity to built-up areas, surface water, groundwater well points, sensitive sites (airports), land use/land cover, geology, soil type, elevation, slopes, roads, and separation from existing dumpsites. Next, these were combined via an analytical hierarchy technique. Subsequently, restriction buffer analysis was performed on the seven parameters to obtain better and more accurate results, and restricted zones were omitted. Furthermore, the pair-wise comparison used to obtain priorities between the selected criteria showed that the LULC is the most significant criterion in the model, with a relative weight of 0.1829, followed by habitations, with 0.1506. The overall result reveals that approximately 68.96% (21,060.9 ha) of the study area is unsuitable, while 24.36% (7441.53 ha) and 6.68% were considered less and highly appropriate zones, respectively. As a result, this study reveals that despite the vast extent of the study area, the areas ideal for landfill remain severely limited. Therefore, in light of the findings of this study, the municipal council of Hargeisa must reevaluate dumpsite locations and waste management practices to address the issues in the region in a timely manner. Furthermore, this systematic research approach will assist regional and global researchers, policymakers, and municipal governments.

Energetic landscape of polycystin channel gating

Members of the polycystin family (PKD2 and PKD2L1) of transient receptor potential (TRP) channels conduct Ca2+ and depolarizing monovalent cations. Variants in PKD2 cause autosomal dominant polycystic kidney disease (ADPKD) in humans, whereas loss of PKD2L1 expression causes seizure susceptibility in mice. Understanding structural and functional regulation of these channels will provide the basis for interpreting their molecular dysregulation in disease states. However, the complete structures of polycystins are unresolved, as are the conformational changes regulating their conductive states. To provide a holistic understanding of the polycystin gating cycle, we use computational prediction tools to model missing PKD2L1 structural motifs and evaluate more than 150 mutations in an unbiased mutagenic functional screen of the entire pore module. Our results provide an energetic landscape of the polycystin pore, which enumerates gating sensitive sites and interactions required for opening, inactivation, and subsequent desensitization. These findings identify the external pore helices and specific cross‐domain interactions as critical structural regulators controlling the polycystin ion channel conductive and nonconductive states.

Atmospheric Observation of Fluorinated Greenhouse Gases around Four Chemical Plants in China

Due to the high global warming potential and rapidly increasing atmospheric concentrations of fluorinated greenhouse gases (hereinafter referred to as F-gases), the emission estimation has been widely studied. Additionally, the atmospheric observation supports the emission estimation. However, there are few F-gas studies with respect to chemical plants. In this study, we firstly carried out atmospheric observation studies of F-gases around chemical plants in China. Four typical chemical plants were selected, and the concentration levels, their concentration differences (hereinafter referred to as the up–down difference) and enhanced ratios (hereinafter referred to as the up–down enhanced ratio) of the F-gases at upwind and downwind sites in the four plants were observed. Both the upwind and downwind observation results of each plant showed that the average concentrations of HFCs were the highest (57%–85%), followed by PFCs, while the total average concentrations of SF6 and NF3 only accounted for less than 5%. The F-gases, with both the larger up–down enhanced ratios and the larger up–down differences in each plant, may suggest larger emission strengths during fluorinated production, by-products and usage processes. Additionally, the numbers of F-gas species emitted from Plants A, B and C were all significantly higher than those from Plant D. This may be because the F-gases in Plants A, B and C were emitted not only during fluorinated production and by-product processes, but also during usage processes, with respect to refrigeration and air-conditioning or foam insulation materials. The F-gases emitted by each plant did not cause toxicity to humans at sensitive sites; however, they can cause nonnegligible climate impacts. In the future, it is necessary to select more typical chemical plants to carry out the atmospheric observation of F-gases, with a higher observation frequency and larger sample size, to further estimate F-gas emissions from chemical plants in China.

The high diversity of Scedosporium and Lomentospora species and their prevalence in human-disturbed areas in Taiwan.

Scedosporium and Lomentospora are important opportunistic pathogens causing localized or disseminated infection in humans. Understanding their environmental distribution is critical for public hygiene and clinical management. We carried out the first environmental survey in urbanized and natural regions in Taiwan. Overall, Scedosporium and Lomentospora species were recovered in 132 out of 273 soil samples (48.4%) across Taiwan. We morphologically and molecularly identified six Scedosporium species and one Lomentospora species. All four major clinical relevant species were isolated with high frequency, i.e. S. apiospermum (42.4%), S. boydii (21.8%), L. prolificans (14.5%), S. aurantiacum (8.5%); two clinically minor species, Pseudallescheria angusta (6.7%) and S. dehoogii (5.6%) and a saprobic species, S. haikouense (0.6%), had moderate to rare incidence. These fungal species had high incidence in urban (48.6%) and hospital (67.4%) soil samples, and had limited distribution in samples from natural regions (5%). Multivariate analysis of the fungal composition revealed strong evidence of the preferential distribution of these fungi in urban and hospital regions compared to natural sites. In addition, strong evidence suggested that the distribution and abundance of these fungal species were highly heterogeneous in the environment; samples in vicinity often yielded varied fungal communities. We concluded that these fungal species were prevalent in soil in Taiwan and their occurrences were associated with human activities. Although hygiene sensitive sites such as hospitals were not harboring heavier fungal burdens than other urban facilities in our survey, still, aware should be taken for the high frequency of these clinical relevant species around hospital regions.

In-situ gastritis diagnosis by an oral-administration NIR fluorescent probe with a large Stokes shift and high signal-to-noise ratio

Gastritis is one of the most common digestive disorders and affecting millions of people worldwide. Recent investigations discovered that abnormal viscosity changes in organisms are associated with an increasing number of diseases that cannot be cured or managed. However, the relationship between gastritis and viscosity has not been explored so far due to lacking the suitable tools for in situ detecting the variations of viscosity in stomach. Herein, we developed a new oral-administration fluorescent probe (NS-V) for in situ elucidation of gastritis viscosity variations, for the first time. Based on the TICT mechanism, the probe employs naphthalene as the fluorescence platform, the rotatable single bond as the viscosity sensitive site, N, N-dimethyl as the strong electron donating moiety and the pyridine salt as the strong withdrawing group to enlarge the π-conjugated system to prolong the emission wavelength. Interestingly, NS-V revealed a good fluorescence response for viscosity at the NIR region from a silent “off” state to “on” and demonstrated high sensitivity, large Stokes shift (262 nm in MeCN), and high signal-to-noise ratio. In addition, NS-V could elucidate the altered mitochondrial viscosity in inflammatory cells. More importantly, utilizing these satisfactory features of NS-V, we discovered a significant increase in viscosity in the gastritis mice. Notably, with the assistance of the oral fluorescence molecule, in vivo and in situ visualizing for the first time revealed the positive correlation between viscosity and gastritis. This work provides an important basis for the diagnosis of gastritis and the robust probe developed in this work possesses a potential application in diagnosis of gastritis without any pain.

Mohs Surgeons Dominate Cutaneous Reconstructions in Cosmetically and Functionally Sensitive Sites: Medicare Trends From 2013 to 2019.

Although dermatologists perform more cutaneous reconstructions than any other specialists for the Medicare population, the perception of dermatologists as surgeons may not be as fully recognized. Mohs surgeons are trained in complex reconstructions of cosmetically and functionally sensitive (CFS) sites, although the proportion they account for is unknown. To quantify the proportion of cutaneous reconstructions in CFS sites performed by Mohs surgeons compared with other specialists, and to identify trends from 2013 to 2019. A cross-sectional analysis was performed using the Medicare Public Use Files for 2013 to 2019. Data were stratified by physician specialty, with dermatologists further subdivided into Mohs surgeons and non-Mohs dermatologists. Mohs surgeons performed 75.3% of all reconstructions in 2019, a significant increase from 2013 ( p < .0001). Mohs surgeons dominated nearly every type of CFS cutaneous reconstruction, with significant increases in proportion ( p < .0001) from 2013 to 2019 for every category except interpolation flaps. Complex repairs were the most commonly performed cutaneous reconstruction type. Mohs surgeons perform far more cutaneous reconstructive surgeries in CFS sites than any other specialty for the Medicare population, with significant increases in their lead over the study period.

Projected effects of climate change on marine ecosystems in Southeast Asian seas

The seas of Southeast Asia are home to some of the world’s most diverse ecosystems and resources that support the livelihoods of millions of people. Climate change will bring temperature changes, acidification and other environmental change, with uncertain consequences for human and natural systems, but there has been little regional-scale climate modelling of the marine ecosystem. We present initial dynamically downscaled projections using a biogeochemical model suitable for coastal and shelf seas. A coupled physical-biogeochemical model with a resolution of 0.1° (approximately 11 km) was used to create projections of future environmental conditions under moderate (RCP4.5) and high (RCP8.5) greenhouse gas scenarios. Changes for different parts of the region are presented, including four sensitive coastal sites of key importance for biodiversity and sustainable development: UNESCO Biosphere Reserves at Cu Lao Cham-Hoi An in Vietnam, Palawan in the Philippines and Taka Bonerate-Kepulauan Selayar in Indonesia, and coastal waters of Sabah, Malaysia, which include several marine parks. The projections show a sea that is warming by 1.1 to 2.9°C through the 21st century, with dissolved oxygen decreasing by 5 to 13 mmol m-3 and changes in many other environmental variables. The changes reach all parts of the water column and many places are projected to experience conditions well outside the range seen at the start of the century. The resulting damage to coral reefs and altered species distribution would have consequences for biodiversity, the livelihoods of small-scale fishers and the food security of coastal communities. Further work using a range of global models and regional models with different biogeochemical components is needed to provide confidence levels, and we suggest some ways forward. Projections of this type serve as a key tool for communities and policymakers as they plan how they will adapt to the challenge of climate change.

Mid and late Holocene climate changes recorded by biomarkers in the sediments of Lake Gouchi and their relationship with the cultural evolution of northern Shaanxi

The climatic and environmental characteristics of the Holocene are much debated, especially the occurrence of a climatic optimum in the mid-Holocene and the interactions between human civilization and the environment. Knowledge of the Holocene climatic evolution of the Mu Us Sandy Land in North China is important for understanding the cultural development of northern Shaanxi. However, few continuous and high-resolution lake sedimentary records are available from the region. We selected Lake Gouchi, a climatically sensitive site in the Mu Us Sandy Land, for a study of sedimentary organic indicators such as n-alkanes, with the objective of reconstructing the regional climatic history since the mid-Holocene. Our results indicate that during 8130–4500 BP, the regional climate was relatively warm and humid, the terrestrial vegetation was dominated by woody plants, and the nutrient level of the lake was relatively stable. Then the climate gradually became arid. However, at the beginning of 2500 BP, there was an 800-year period of warm and humid conditions. Entering the historical period there was an increase in the environmental impacts of human activities. Overall, the climate of the Gouchi area was influenced by the response of the East Asian summer monsoon to changes in Northern Hemisphere summer insolation, which were responsible for the mid-Holocene Maximum. Comparison of the climatic record of Lake Gouchi with the sequence of cultural evolution in northern Shaanxi reveals a distinct relationship. Favorable climatic conditions were associated with technological development, an increasing population, and a flourishing civilization; whereas less favorable climatic conditions were associated with cultural stagnation or decline.

Using drone imagery to obtain population data of colony-nesting seabirds to support Canada’s transition to the global Key Biodiversity Areas program

Identifying of global or national biodiversity ‘hotspots’ has proven important for focusing and prioritizing conservation efforts worldwide. Canada has nearly 600 Important Bird and Biodiversity Areas (IBAs) identified by quantitative criteria to help guide avian conservation and management. Marine IBAs capture critical waterbird habitats such as nesting colonies, foraging sites, and staging areas. However, due to their remote locations, many lack recent population counts. Canada has begun transitioning IBAs into the global Key Biodiversity Areas (KBA) program; KBAs identify areas that are important for the persistence of biodiversity and encompass a wider scope of unique, rare, or vulnerable taxa. Assessing whether IBAs qualify as KBAs requires current data – as will future efforts to manage these biologically important sites. We conducted a pilot study in the Chain Islets and Great Chain Island IBA, in British Columbia, to assess the effectiveness of using drones to census surface-nesting seabirds in an IBA context. This IBA was originally designated for supporting a globally significant breeding colony of Glaucous-winged Gulls (Larus glaucescens). Total nest counts derived from orthomosaic imagery (1012 nesting pairs) show that this site now falls below the Global and National IBA designation criterion threshold, a finding consistent with regional declines in the species. Our trial successfully demonstrates a flexible and low cost approach to obtaining population data at an ecologically sensitive KBA site. We explore how drones will be a useful tool to assess and monitor species and habitats within remote, data-deficient IBAs, particularly during the transition to KBAs.