Introduction: Human Immunodeficiency virus is a chronic infection that attacks the immune system of the human body, particularly CD4 T lymphocytes. Combined antiretroviral therapies are highly effective in virological suppression of human immunodeficiency virus infection. It has been shown that some retroviral therapies have a higher nephrotoxicity potential. As a result of renal injury, serum creatinine increases, and the estimated glomerular filtration rate is reduced. The aim of our study was to assess changes in kidney function during a 24-month period in HIV-positive patients who were begun on combined antiretroviral therapy. Material-method: A total of 127 HIV positive patients were enrolled. The patients were divided into five groups; patients who received no therapy were designated as Group 1; those that received Dolutegravir/Abacavir/Lamivudine combination as Group 2; those that received Elvitegravir/Cobicistat/Emtricitabine/Tenofovir Alafenamide Fumarate combination as Group 3; those that received Emtricitabine/Tenofovir Disoproxil Fumarate/Dolutegravir combination as Group 4; and those that received Emtricitabine/Tenofovir Disoproxil Fumarate/Raltegravir combination as Group 5. We compared the effects of these drugs on estimated glomerular filtration rate during a 24-month follow-up period. Results: At the 24th month of therapy, a significant difference was observed between the eGFR levels of the study groups (p:<0.001). eGFR level was significantly higher in Group 4 compared to Groups 1, 2, and 3 (p:0.009, p:<0.001, p:<0.001, respectively) while it was significantly lower in Group 5 than groups 1, 2, and 3 (p:0.005, p:<0.001, p:<0.001, respectively). No significant eGFR difference was found between Group 4 and Group 5 (p>0.05). Serum creatinine level was significantly higher in Groups 4 and 5 compared to the other groups (p<0.001). Conclusion: The use of TDF-containing regimens causes renal dysfunction. Therefore, we recommend close monitoring of renal function, especially in patients treated with TDF.

Objective: We aimed to investigate the effects of hypotensive anesthesia on oxidative stress with serum thiol/disulfide balance in patients undergoing elective septoplasty procedures under general anesthesia. Methods: Seventy-two patients between the ages of 18-60, with a physical condition I –II, according to the American Society of Anesthesiologists, were included in this prospective observational study. Septoplasty was chosen for standard surgical stress. According to the maintenance of anesthesia, patients were divided into the groups as Hypotensive Anesthesia (n = 40) and Normotensive Anesthesia (n = 32). Serum thiol/disulfide levels were measured by the method developed by Erel & Neşelioğlu. Results: The native thiol and total thiol values of both groups measured at the 60th minute intraoperatively were significantly lower than the preoperative values (both p < 0.01). Intraoperatively, at the 60th minute, there was no significant difference in terms of post-native thiol and post-total thiol levels between hypotensive and normotensive anesthesia groups (p = 0.68, and p = 0.81, respectively). Age > 40 years and female gender were found to have a significant effect on dynamic oxidative stress (p = 0.002, and p = 0.001, respectively). Conclusion: This pilot study has found that hypotensive anesthesia had no adverse effect on dynamic thiol/disulfide balance in elective surgeries.

Introduction: Ablation Index guided ablation according to the CLOSE protocol is very effective in terms of chronic pulmonary vein isolation (PVI). However, the optimal RF power remains controversial. Here, we thought to investigate the efficiency and safety of an AI guided fixed circumferential 50W high power short duration (HPSD) PVI using the CLOSE protocol Methods and results: In a single-centre prospective “proof of concept” trial 40 patients underwent randomized PVI using AI guided RF ablation without oesophageal temperature monitoring. In 20 patient fixed 50W HPSD was used irrespective to the anatomical localization. 20 subjects were ablated with standard power settings (20W posterior and 40W roof and anterior wall). Additionally, 80 consecutive patients were treated according to the HPSD protocol to gather additional safety data. All patients underwent post-procedural oesophago-gastro-duodenoscopy to reveal oesophageal lesions (EDEL). The mean total procedural time was 80.3±22.5 minutes in HPSD compared to control 109.1±27.4 (p<0.001). The total RF-time was significantly lower in HPSD 1379±505 sec vs. control 2374±619 sec (p<0.001).There were no differences in periprocedural complications. EDEL occurred in 13% in the HPSD and 10% in control group. EDEL occurring in the 50W HSDP patients were smaller, more superficial and had a faster healing tendency. Conclusions: A fixed 50W HPSD circumferential PVI relying to the ablation index and CLOSE protocol reduces the total procedure time and the total RF time compared to standard CLOSE protocol, without increasing the complication rates. The incidence of oesophageal lesions was similar using 50W at the posterior atrial wall.

This study conducted simulation and experimental analysis on a dual rotor horizontal axis wind turbine to determine the effect of rotor separation on its performance. An air study was conducted to optimize the turbine blades to a local climate of Trinidad, it was determined that a NACA 64-315 air foil would be the most optimum for the conditions. QBlade software was used for the simulation, the power flow performance for multiple iterations of wind speed was found for the design. The effect of rotor separation on the performance of the dual rotor wind turbine was studied with rotor separation 0.25 m to 3.0 m at an interval of 0.25 m and it was discovered that the smallest rotor separation 0.25 m shows the largest tip speed ratio, while the largest rotor separation distance 3m has the smallest tip speed ratio at a fan speed of 1m/s. Also, as the rotor separation decreases the power coefficient (C P ) and the total power increase, which resulted to high energy output of the DRHAWT. This result is valid for the QBlade simulations and the experimental results.

Niche theory predicts specialists will be more sensitive to environmental perturbation compared to generalists, a hypothesis receiving broad support in free-living species. Based on their niche breadth, parasites can also be classified as specialists and generalists, with specialists infecting only a few and generalists a diverse array of host species. Here, using avian haemosporidian parasites infecting wild bird populations inhabiting the Western Ghats, India as a model system, we elucidate how climate, habitat and human disturbance affects parasite prevalence both directly and indirectly via their effects on host diversity. Our data demonstrates that anthropogenic disturbance acts to reduce the prevalence of specialist parasite lineages, while increasing that of generalist lineages. Thus, as in free-living species, disturbance favors parasite communities dominated by generalist vs. specialist species. Because generalist parasites are more likely to cause emerging infectious diseases, such biotic homogenization of parasite communities could increase disease emergence risk in the Anthropocene

Dissolved oxygen is one of the prime parameters for assessing the water quality of any stream and the health status of aquatic life. The dissolved oxygen present in the water body plays an essential role in deciding water treatment processes to enhance water quality up to the design standards for the specified water use. Thus, the accurate estimation of dissolved oxygen concentration is necessary to evolve measures for maintaining the riverine ecosystem and designing the appropriate water treatment plants. Machine learning techniques are becoming useful tools for the prediction and simulation of water quality parameters. With these viewpoints, a study was carried out in the Delhi stretch of Yamuna River, India, and physiochemical parameters were examined for five years to simulate the dissolved oxygen using different machine learning techniques. Simulation and prediction competencies of ANFIS grid partitioning (ANFIS-GP) and ANFIS subtractive clustering (ANFIS-SC) were tested on various water quality parameters. Variation in dissolved oxygen was examined on various combinations of parameters. ANFIS-GP has been designed using the Gaussian function, and ANFIS-SC works on the likelihood of cluster centers. Results obtained from the models were evaluated using root mean square error (RMSE) and coefficient of determination (R2) to identify the optimum solution and appropriate combination of parameters that simulate the observed dissolved oxygen. Results of ANFIS-GP and ANFIS-SC indicate that both the models produce suitable solutions for the prediction; however, ANFIS-GP outperforms the ANFIS-SC and could act as a useful tool for defining, planning, and management of water quality parameters.

Accurate diagnoses of vulnerability of seawater intrusion (SWI) into aquifers are required to ensure sustainable utilization of groundwater resources in coastal areas. GALDIT was selected to assess the SWI vulnerability on western coastal areas of South Korea. Climate change trends are updated every year. The existing GALDIT method has various scores to express the changing observed values. However, they are limited because of their sensitivity in the assessment of regional characteristics or climatic change due to low weight flexibility. Therefore, this study assessed vulnerability to SWI by classifying the existing GALDIT into static and dynamic parameters. The static parameters include groundwater occurrence (G), aquifer hydraulic conductivity (A), and distance from the shore (D), whereas the dynamic parameters include height to groundwater level above sea level (L), impact of existing status of seawater intrusion (I), and aquifer thickness (T). The monthly mean was used as the dynamic index to reflect monthly variations. To indicate the temporal trend of parameter L was calculated based on the data observed at the sea level station adjacent to the groundwater level station. To sensitively reflect the monthly changes in values, the range of scores was divided into 10 parts. The calculated GALDIT index showed that the most vulnerable month was September. In the progress of SWI, vulnerability was assessed monthly to highlight the differences in parameters that fluctuate seasonally. The proposed method can be used to apply intensive countermeasures to vulnerable sites and build an operation plan considering the vulnerability period.

A 71-year-old woman who was resuscitated from cardiac arrest after pericardial drainage, was admitted to our hospital. Enhanced computed tomography demonstrated pericardial effusion due to rupture of posterior ventricular myocardium. She underwent emergent surgical repair. A 20-mm tear in the extensively necrotic left ventricular posterior wall and active hemorrhage were identified. Sutureless repair using three sheets of TachoSil (CSL Behring, Tokyo, Japan) and fibrin glue was performed. To reduce ventricular pressure to avoid re-rupture and formation of ventricular aneurysm, deep sedation was followed in the intensive care unit for 2 weeks. The patient returned to her normal daily life and is progressing well for more than 5 months after the surgery.

Abstract Background: Graft-versus-host disease (GVHD) is a common and undesirable complication of hematopoietic cell transplant (HCT) for non-malignant disorders (NMD). Understanding the incidence and risk factors for GVHD in children with NMD is an important step in developing strategies for its prevention. Study Design: This is a retrospective, registry, study that included children with NMD receiving HCT in 5 centers in Florida between 2010 and 2019. Results: Among 183 patients evaluable for GVHD, acute GVHD (aGVHD) grades I, II, III, and IV were present in 18%, 12.6%, 3.8% and 5.5% of patients, respectively. Limited and extensive chronic GVHD (cGVHD), were observed in 8.7% and 12.6% of patients. Patients with aGVHD grade III/IV had significantly lower 3-year survival rates than those without aGVHD, or those with aGVHD grade I/II (52.9% [95% confidence interval (CI) 34-83] vs. 90.1% [95% CI 84-96], vs. 98.1% [95%CI 95-100], p<0.001). Patients without cGVHD and those with limited and extensive cGVHD had 3-year survival rates of 88.9% [95%CI 84-94], 91.7% [95%CI 77-100], and 84.8% [95%CI 70-100], respectively, log rank p=0.3. Receiving transplant from an HLA-mismatched unrelated donor (MMUD), as compared to a matched related donor (MRD), increased the risk for aGVHD grade III/IV (Odds ratio 10.4 [95% CI 2.5-47.6]). There were no cases of aGVHD grade III/IV among recipients of mismatched related/haploidentical transplants. Conclusions: Grade III/IV aGVHD, which significantly reduced overall survival, was reported in 9.3% of children with NMD receiving HCT. Risk factors included HCT from a MMUD but not mismatched related donors.

Background Previous studies have explored post-hematopoietic cell transplant (HCT) outcomes by race in adults; however, pediatric data addressing this topic are scarce. Procedure This retrospective registry study included 238 White (W) and 57 Black (B) children with hematologic malignancies (HM) receiving first allogeneic HCT between 2010 and 2019 in one of five Florida pediatric HCT centers. Results We found no differences between W and B children by transplant characteristics, other than donor type. There was a significant difference in use of HLA-mismatched donors (HLA-MMD) (53% W, 71% B, p=0.01). When comparing HLA-MMD use to fully HLA-matched donors, B had RR of 1.47 [95% CI 0.7-3] of receiving a mismatched unrelated donor (MMUD), RR of 2.34 [95% CI 1.2-4.4] of receiving a mismatched related donor (MMRD), and a RR of 1.9 [95% CI 0.99-3.6] of receiving a mismatched cord blood donor (MMCBD) HCT, respectively. There was no significant difference in the incidence of aGVHD (48% W, 35% B), p=0.1 or cGVHD (19% W 28% B, p=0.1), or primary cause of death. Overall 24-month survival was 61% [95% CI 54-68%] for W, and 60% [95% CI 38-68] for B children, log-rank p=0.72. While HLA matching improved survival in W children, the number of B children receiving HLA-matched HCT was too small to identify the impact of HLA matching on survival. Conclusions In this contemporary cohort of children with HM we found that B children were more likely to receive HLA-MMD transplants, but this did not adversely affect survival or GVHD rates.

Background – Loss of bone mineral is a common concomitant of the treatment of acute lymphoblastic leukemia (ALL) due mainly to chemotherapy, especially with corticosteroids. Osteopenia/osteoporosis may persist long into survivorship. Measurement of bone mineral density (BMD) by dual energy X-ray absorptiometry is limited to two-dimensionality and cannot distinguish trabecular from cortical bone. Methods – A sample of 74 subjects, more than 10 years from diagnosis, underwent peripheral quantitative computed tomography (pQCT) at metaphyseal (trabecular bone) and diaphyseal (cortical bone) sites in the radius and tibia. pQCT provides three-dimensional assessment of bone geometry, density and architecture. Results – Similarities of average values in multiple metrics with those in healthy subjects obscured deficits in both trabecular and cortical bone, as well as bone strength, revealed by Z scores using an ethnically comparable sample of healthy individuals. Connectivity, a measure of bone architecture and a surrogate measure of bone strength, was lower in females than males. Survivors of standard risk ALL had greater connectivity in and more compact trabecular bone than high risk survivors who had received more intensive osteotoxic chemotherapy. There were no statistically significant differences in any of the metrics at any of the sites between subjects who had or had not a history of fracture, cranial irradiation or use of a bisphosphonate. Conclusions – These long-term survivors of ALL have somehat compromised bone health, but data in comparable healthy populations are limited. Longitudinal studies in larger and more ethnically diverse cohorts will provide greater insight into bone health in this vulnerable population.

The enormous complexity of the eukaryotic ribosome has been a real challenge in unlocking the mechanistic aspects of its amazing molecular function during mRNA translation and many non-canonical activities of ribosomal proteins in eukaryotic cells. While exploring the uncanny nature of ribosomal P proteins in malaria parasites Plasmodium falciparum, the 60S stalk ribosomal P2 protein has been shown to get exported to the infected erythrocyte (IE) surface as an SDS resistant oligomer during the early to mid trophozoite stage. Inhibiting IE surface P2 either by monoclonal antibody or through genetic knockdown resulted in nuclear division arrest of the parasite. This very strange and serendipitous finding has led us to explore more about un-canonical cell biology and structural involvement of P2 protein in Plasmodium in the search for a novel biochemical role during parasite propagation in the human host.

A high-quality reference genome is necessary to determine the molecular mechanisms underlying important biological phenomena; therefore, in the present study, a chromosome-level genome assembly of the Chinese shrimp Fenneropenaeus chinensis was performed. Muscle of a male shrimp was sequenced using PacBio platform, and assembled by Hi-C technology. The assembled F. chinensis genome was 1,465.32 Mb with contig N50 of 472.84 Kb, including 57.73% repetitive sequences, and was anchored to 43 pseudochromosomes, with scaffold N50 of 36.87 Mb. In total, 25,026 protein-coding genes were predicted. The genome size of F. chinensis showed significant contraction in comparison with that of other penaeid species, which is likely related to migration observed in this species. However, the F. chinensis genome included several expanded gene families related to cellular processes and metabolic processes, and the contracted gene families were associated with virus infection process. The findings signify the adaptation of F. chinensis to the selection pressure of migration and cold environment. Furthermore, the selection signature analysis identified genes associated with metabolism, phototransduction, and nervous system in cultured shrimps when compared with wild population, indicating targeted, artificial selection of growth, vision, and behavior during domestication. The construction of the genome of F. chinensis provided valuable information for the further genetic mechanism analysis of important biological processes, and will facilitate the research of genetic changes during evolution.

A document by Nicolas Prud'homme, written on Authorea.

Epidermal melanocyte loss in vitiligo, triggered by stresses ranging from trauma to emo-tional stress, chemical exposure or metabolite imbalance, to the unknown, can stimulate oxidative stress in pigment cells which secrete damage-associated molecular patterns that then initiate innate immune responses. Antigen presentation to melanocytes leads to stim-ulation of autoreactive T cell responses, with further targeting of pigment cell. Studies show a pathogenic basis for cellular stress, innate immune responses and adaptive immun-ity in vitiligo. Improved understanding of the aetiological mechanisms in vitiligo has already resulted in successful use of the Jak-1 inhibitors in vitiligo. In this review we outline the cur-rent understanding of the pathological mechanisms in vitiligo, and locate loci to which therapeutic attack might be directed.

Background and Purpose: Many psychotherapeutic drugs including clozapine have a polypharmacological profile and act on GABAA receptors, where subtype-specific information is often lacking. Patients with schizophrenia show alterations in function, structure and molecular composition of the hippocampus, and a recent study demonstrated aberrant levels of hippocampal α5 subunit containing GABAA receptors. Experimental Approach: Functional studies of GABA modulatory effects by antipsychotic and antidepressant medications were performed in several GABAA receptor subtypes by two‐electrode voltage‐clamp electrophysiology using Xenopus laevis oocytes. Computational structural analysis was employed to design mutated constructs of the α5 subunit, probing a novel binding site. Computational ligand analysis complemented the functional and mutational data. Key Results: We show that the antipsychotic drugs clozapine and chlorpromazine have negative modulatory effects on multiple GABAA receptor subtypes, including α5-containing. On the latter we show negative modulatory effects for five additional antipsychotic and antidepressant drugs. Based on a chlorpromazine binding site observed in a GABA-gated bacterial homologue, we identified a novel site in α5 GABAA receptor subunits. Conclusion and Implications: Our findings support previous studies suggesting a link between some of the therapeutic effects of clozapine and its negative modulatory action on certain GABAA receptor subtypes. The novel site we describe in this study is a new potential target for optimizing antipsychotic medications with beneficial polypharmacology.

Bas et al. report the clinical measurement, using High Performance Liquid Chromatography (HPLC), of asymmetric dimethyarginine in two groups of patients undergoing aortic coarctation repair.

Soil is the major natural resource on which human life depends for the production of food, feed, fiber, renewable energy and raw materials, as well as the protection of the planet's natural ecosystems and climate system. Increasing soil degradation and subsequent ecosystem degradation is a current concern in agriculture and the environment. Soil degradation poses many challenges to feed the world's growing population. This food insecurity will also reduce the income of the agricultural sector, which will lead to a decrease in economic income. Soil degradation will lead to environmental threats, the extinction of animals and plants, the reduction of biodiversity, water loss, and disruption of water and carbon cycles. The use of new technologies such as biological crusts has provided great hope for the recovery and restoration of degraded ecosystems. Inoculation of biological crusts, especially cyanobacteria, has had positive results on improving soil conditions and restoration degraded soils. In this article, has been introduced the biocrusts communities considering cyanobacteria species to restore degraded soils. We reported the results of cyanobacteria applications in soil conservation in arid environments of Iran.

Abstract Background: To ascertain the estrogenic effect of Zhuang Medicated Thread Moxibustion (ZMTM) and explore its time-sensitive impact on estradiol in female perimenopausal rats. Methods: Female rats were randomized into four groups of 10 rats, each consisting of the control, model, ZMTM, and acupuncture groups. The perimenopausal syndrome was induced in the last three groups with a daily subcutaneous dose of 80 mg/kg of 4- vinylcyclohexene diepoxide for 15 days. Afterward, rats in the model and control groups were fed routinely, while rats in the ZMTM and acupuncture groups were treated with six ZMTM and acupuncture courses, respectively. The rats’ general condition and estradiol (E2) levels in the rats’ serum were assessed. Results: Following the six courses of treatment, the E2 level in the model group was significantly the lowest, while the regular group was the highest (P < 0.05). There was also a gradual increase in the E2 level of the ZMTM group compared to the model and acupuncture groups, such that after the 5th and 6th courses of treatment, their E2 level was significantly higher than the model and acupuncture groups (P < 0.05). The control group had a better condition than all other groups, while the ZMTM group was better than the model and acupuncture groups. Conclusion: ZMTM can improve perimenopausal induced rats’ estrogen level, and this effect becomes better with each further treatment course.

Objectives: Treatment of connective tissue disease-related interstitial lung disease (CTD-ILD) remains challenging. The literature related to the immunosuppressive drugs is very limited in most CTDs and there is no previously reported study comparing induction regimens in patients with newly defined ‘interstitial pneumonia with autoimmune features (IPAF), We aimed to investigate the efficacy of azathioprine (AZA) used in induction regimens for interstitial lung disease in a variety of connective tissue disorders including IPAF, and compare it with cyclophosphamide (CYC) Methods. In a retrospective study, all patients presented with interstitial lung disease to the rheumatology and/or pulmonology departments in a tertiary referral centre, between 2009 and 2019. Five major CTD groups were defined; systemic sclerosis, rheumatoid arthritis (RA), primary Sjögren syndrome (pSS), inflammatory myositis (IMS) and interstitial pneumonia with autoimmune features (IPAF). All patients who satisfied one of these and received AZA or CYC for induction therapy for at least 6 months were included in the study. Treatment responses at six months and side effects were analyzed. Results: There were 1351 patients diagnosed with ILD. Of these, 328 patients were identified as CTD-ILD, satisfying the classification criteria of one of the CTDs. Among these, 57 patients received AZA and 79 patients received CYC for induction therapy. CYC treatment resulted in a 2.41 % increase in FVC, however, AZA resulted in a 1.44% decline in FVC predicted (p=0.041). Propensity score matching was used to reduce selection bias, AZA treatment was related to increased risk of progression (50% vs 13.5%, p:0.002). Conclusion: CYC is superior to AZA in induction therapy of CTD-ILD.

The Corona virus SARS-CoV2 that causes COVID-19 has effects that until now have not been explained. The widespread damage of SARS-CoV2, the comorbidities in critically ill COVID-19 patients, and the symptoms of post-COVID-19 patients show striking similarities with conditions that are related to depletion of nitric oxide (NO) in the human body. Many of the symptoms of the disease may be caused by acute depletion of NO by the immune system. Patients with the highest COVID-19 burden often have comorbidities that are related to chronic depletion of NO. Post-COVID-19 health problems may be caused by earlier depletion of NO. Successful therapy requires sufficient NO levels. Supplementation with NO will increase immunity, help prevent thrombosis, and improve breathing, kidney functions, blood flow and oxygenation in patients, elderly patients and patients with comorbidities in particular. Furthermore, NO helps to prevent SARS-CoV2 from entering the human cell and to suppress viral RNA production. NO is not easy to supplement. A few SARS patients have been treated with inhaled NO with positive results, but inhaled NO can only deliver small quantities of NO. A new therapy has been developed to more effectively supplement NO. It combines the ingestion of nitrates (as NO donor), N-acetylcysteine and vitamin C (promoting NO metabolism) with electrostimulation of the muscles (to trigger the release of NO). It is expected that this therapy can ease the most serious symptoms of (post) COVID-19, especially for elderly and people with comorbidities. A patent has been applied for.

There are three types of proteins in coronaviruses: nonstructural, structural, and accessory proteins. Coronavirus proteins are essential for viral replication and for the binding and invasion of hosts and the regulation of host cell metabolism and immunity. This study investigated the amino acid sequence similarity and identity percentages of 10 proteins in SARS-CoV-2, SARS-CoV and the Rhinolophus affinis bat coronavirus (BatCoV RaTG13). The investigated proteins were the 1ab polyprotein, spike protein, orf3a, the envelope protein, the membrane protein, orf6, orf7a, orf7b, orf8, and the nucleocapsid protein. The online sequence alignment service of The European Molecular Biology Open Software Suite (EMBOSS) was used to determine the percentages of protein similarity and identity in the three viruses. The results showed that the similarity and identity percentages of the SARS-CoV-2 and BatCoV RaTG13 proteins were both greater than 95%, while the identity and similarity percentages of SARS-CoV-2 and SARS-CoV were both greater than 38%. The proteins of SARS-CoV-2 and BatCoV RaTG13 have high identity and similarity compared to those of SARS-CoV-2 and SARS-CoV. Graphic abstract The proteins of the SARS-CoV-2 are most identical and similar to those of BatCoV RaTG13 than to the proteins of SARS-CoV

Models of host-pathogen interactions help to explain infection dynamics in wildlife populations and to predict and mitigate the risk of zoonotic spillover. Insights from models inherently depend on the way contacts between hosts are modelled, and crucially, how transmission scales with animal density.Bats are important reservoirs of zoonotic disease and are among the most gregarious of all mammals. Their population structures can be highly heterogenous, underpinned by ecological processes across different scales, complicating assumptions regarding the nature of density-transmission scaling. Although models commonly parameterise transmission using metrics of total abundance, whether this is an ecologically representative approximation of host-pathogen interactions is not routinely evaluated.We collected a 13-month dataset of roosting Pteropus spp. from 2,522 spatially referenced trees across eight roosts to compare density estimates across scales (roost-level, subplot-level, tree-level). We then focus on tree-level measures of abundance and density, the scale most likely to be relevant for virus transmission between tree-roosting Pteropus , and evaluate whether roost features at different scales are predictive of local dynamics.Our density estimates varied greatly by scale. Mean density ofPteropus at the roost level was 13-fold lower than at a subplot-level that accounted for heterogenous distributions of bats (0.38 bats/m2 vs 5.13 bats/m2). Additionally, roost-level measures (roost abundance and roost area) did not represent tree-level abundance or tree-level density, with models explaining minimal variation in tree-level measures.This indicates that basic measures, such as roost-level population counts, may not provide adequate approximations for population dynamics at scales relevant for transmission, and that alternative measures are needed to compare transmission potential between roosts. From the best candidate models, the best predictor of local population structure was tree density within roosts, where roosts with low tree density had a higher abundance but lower density of bats (more spacing between bats) per tree.Together, these data highlight unpredictable and counterintuitive relationships between abundance and density, and between measures at different scales. More nuanced modelling of transmission, spread and spillover from bats likely requires alternative approaches to integrating contact structure in host-pathogen models, rather than simply modifying the transmission function.

Little is known about the sources and age of C respired from tree roots. Previous research in tree stems has identified two functional pools of non-structural carbohydrates (NSC): an ‘active’ pool supplied directly from canopy photo-assimilates that supports metabolism and a ‘stored’ pool used when fresh C supplies are limited. We compared the C isotope composition of water soluble NSC and respired CO2 for aspen roots (Populus tremula hybrids) that were cut off fresh C supply via stem-girdling and prolonged incubation of excised roots. We used bomb radiocarbon to estimate the time elapsed since C fixation for respired CO2, water-soluble C, and structural α-cellulose. While freshly excised roots respired CO2 with mean age <1 yr, within a week the age increased to 1.6-2.9 yr. Freshly excised roots from trees girdled ~3 months previously had similar respiration rates and NSC stocks as un-girdled trees, but respired older C (~1.2 yr). We estimate the NSC in girdled roots must be replaced 5-7 times by reserves remobilized from root-external sources. Using a mixing model and observed correlations between Δ14C of water-soluble C and α-cellulose, we estimate ~30% of C is ‘active’ (~5 mg C g-1).