Water level and storage are the most critical components for understanding water cycle changes and mechanisms better. Given the lack of in-situ river level monitoring and consecutive satellite altimetry data in the Yarlung Zangbo River (YZR) in High Mountain Asia (HMA) caused by the harsh environment and complex terrain, obtaining accurate and long-term water characteristic changes is challenging. In this study, we reconstructed the dense time series of the YZR water characteristic changes from 2000 to 2020. The general idea of this method is to obtain the water area information derived from the Global Land Analysis and Discovery (GLAD) dataset, using the hypsometric curves to fill Hydroweb lacked river water level records from the available river area data, and to reconstruct the virtual stations (VSs) water levels in the YZR. Moreover, by combining area estimates with the changes in water level, the variations of the YZR water storage have been obtained. The obtained YZR water storage variation result was compared with the terrestrial water storage anomaly (TWSA) of Brahmaputra basin from Gravity Recovery and Climate Experiment (GRACE) data to discuss the response relationship. Results indicated that the reconstructed water area applied in the YZR with high quantity accuracy (approximately 82%) and the reconstructed water levels agreed reasonably well with Hydroweb water levels with an average R of 0.89. Furthermore, the densified reconstructed water levels provided critical and accurate information on the long-term monitoring in HMA. The YZR water area, level and storage have apparent significant seasonal fluctuations. The declining amplitude of water levels of VSs expanded from the upstream region to the downstream region. In addition, the change in river water storage only accounts for approximately one tenth of that in the basin. This study sheds new light on bridging the gap in monitoring the long-term water characteristic changes over poorly gauged basins by means of optical imaging in combination with partial altimetry satellite, and can be effectively applied in other large rivers in HMA.

The combustion behavior of tackifying resins (such as glycerol ester of colophony/hydrogenated colophony and C9/hydrogenated C9 petroleum resin, namely GEC, GEHC, C9PR and HC9PR, respectively) were investigated using TG-FTIR and density functional theory (DFT) analyses. Results from combustion characteristics indicate tackifying resins and their wastes are a promising fuel for generating energy. The average activation energies obtained by Friedman method for GEC, GEHC, C9PR and HC9PR were 223.51, 162.16, 166.52 and 116.20 kJ/mol, respectively, revealing that (H)C9PR were more readily combustible than GE(H)C, and their hydrogenated products burned more easily than their unhydrogenated ones, which were strongly supported by the TG-FTIR results. DFT calculations also show that the bond dissociation energy of C-C bond of GEC is higher than those of C9PR and GEHC. The best appropriate reaction mechanism evaluated by integral master plots is f(α)=3(1-α)2/3. Volatiles are mainly composed of H2O, CH4, CO2, CO, alcohol, aromatic and carbonyl compounds.

This work reports a complementary descriptor to acidity for metal cations, oxygen affinity, to scale the interaction strength of metal cations with oxygenate groups. A method for measuring oxygen affinity is developed in alkyl methylimidazolium chloride solvents using in-situ far infrared (FIR) spectroscopy. The relative oxygen affinity values of metal cations in metal chlorides with model compounds including cyclopentanol (for alcohols), cyclohexanone (for ketones), ethylene glycol diethyl ether (for ethers), and H2O are measured from the dissociation kinetics of the metal-oxygenate complexes. The concentrations of metal-chloride and metal-oxygenate complexes are determined during evaporative removal of oxygenate molecules according to the FIR absorbance of metal-Cl bonds. The oxygen affinity values are shown to reasonably account for the catalytic performances of metal cations in furfural-acetone condensation and glucose isomerization reactions. The oxygen affinity descriptor could be potentially exploited as an intrinsic property of metal cations broadly in metal chlorides and metal oxides.

Objective To determine the impact of the COVID-19 pandemic on acute admissions and inpatient activity at a tertiary referral centre. Design Retrospective review of coding-based inpatient electronic records. Setting An otolaryngology and head and neck surgery department at a UK major trauma and tertiary referral centre. Participants Otolaryngology patients admitted as an emergency over a period of 12 months pre-COVID19 (01/04/2019-31/03/2020) and 10 months post-COVID19 (01/04/2020-23/01/2021). Main outcome measures Baseline characteristics, admission rates, length of stay (LoS), overall mortality and 30-day mortality. Results 1844 records were reviewed; (1293 pre-COVID19, 551 post-COVID19). Admissions across all age groups were reduced, with an increase in mean age from 40.4 to 47.4 years (p=0.001). LoS remained unchanged (3.74 vs 3.82 days, p=0.251). Epistaxis remained the most common presentation, with an increased LoS compared to the pre-COVID19 cohort. GP referrals reduced from 18.0% to 4.2% (n=233 vs n=23, p<0.001) and ED referrals proportionally increased from 60.9% to 75.3%, n=787 vs n=417, p<0.001). Critical care admissions were higher in the post-COVID19 cohort (OR 1.82 (1.11-2.99) [95% CI], p=0.017). There was no significant difference in overall mortality between groups (n=74, 5.7% vs. n=33, 6.0%; p=0.844). Thirty-day mortality increased from 0.9% (n=12) pre-COVID19 to 2.3% (n=13) post-COVID19 (p=0.03). Conclusions This study demonstrates significant changes and a reduction in acute otolaryngology presentations. Our findings suggest that sicker, frailer patients were admitted during the pandemic. This study highlights important considerations for acute otolaryngology care moving forward after the pandemic.

Background: Implicit biases involve subconscious associations that lead to a negative evaluation of a person based on irrelevant characteristics such as race or gender. This audit of management of patients who missed appointments investigates the presence of implicit bias in our unit. Methods: We retrospectively analysed discharge rates in 285 patients who missed an outpatient appointment between from 1/4/2020 at Guy’s and St Thomas’ Hospital. 285 patients were categorised into predefined ethnic categories: White British (WB) vs Black, Asian and Minority Ethnic (BAME) vs Other White (OW) after reading the patient’s names. In the same fashion, we also assigned gender. Results: We did not find differences in discharge rates among self-reported ethnic and gender groups. Patients with WB sounding names were more likely to be discharged when compared to patients with BAME sounding names (35% vs 58%). Discharge rates between males and females did not differ. Conclusion: Our results suggest that implicit bias may play a role in decision-making whether to rebook a patient after missing an appointment.

Recent technological advancements in synthetic and systems biology have enabled the construction of microbial cell factories expressing diverse heterologous pathways in unprecedentedly short time scales. However, the translation of such laboratory scale breakthroughs to industrial bioprocesses remains a major bottleneck. In this study, an accelerated bioprocess development approach was employed to optimize the biosynthetic pathway of the blockbuster chemotherapy drug, Taxol. Statistical design of experiments approaches were coupled with an industrially relevant high-throughput microbioreactor system to optimize production of key Taxol intermediates, Taxadien-5α-ol and Taxadien-5α-yl-acetate, in engineered yeast cell factories. The optimal factor combination was determined via data driven statistical modelling and validated in 1L bioreactors leading to a 2.1-fold improvement in taxane production compared to a typical defined media. Elucidation and mitigation of a nutrient limitation enhanced product titers a further two-fold and titers of the critical Taxol precursors, Taxadien-5α-ol and Taxadien-5α-yl-acetate were improved to 34 and 11 mg/L, representing a three-fold improvement compared to the highest literature titers in S. cerevisiae. Comparable titers were obtained when the process was scaled up a further five-fold using 5 L bioreactors. The results of this study highlight the benefits of a holistic design of experiments guided approach to expedite early stage bioprocess development.

Background: The aim of this study was to analyze the lung ultrasound (LUS) patterns in combination with clinical-laboratory profiles of children hospitalized for COVID-19 infection in relation to temporal trend of the Italian epidemic. Methods: This was a retrospective study conducted at a pediatric tertiary referral hospital from 15th March 2020 to 15th March 2021. We compared the characteristics of two periods of the pandemic outbreak, the first one in spring and summer (15th March-30th September 2020) and the second one in autumn and winter (1st October 2020-15th March 2021). Results: 28 patients (53.85%) were in the first period, 24 patients (46.15%) were in the second period. The disease severity score was significantly higher in the second period (p=0.02). We observed that the occurrence of the irregular pleural line was seen more frequently in the second period (87.5% vs 60.71%; p=0.03). The B-lines were significantly more frequent in children in the second period (87.5% vs 60%; p=0.03). The several but not-coalescent B-lines were significantly more frequent in the second period (80% vs 41.7%; p=0.05). The LUS score correlated significantly with the disease severity score with a strong relationship (r=0.51, p=0.002). The second phase of the COVID-19 epidemic outbreak had a higher disease severity score than the first phase with a moderate correlation (r= 0.42; p=0.01). Conclusion: The LUS plays an important role in the evaluation of pulmonary involvement in children affected by COVID-19 during different periods of the pandemic in combination with clinical-laboratory findings.

BACKGROUND: High-flow nasal cannula therapy (HFNC) is increasingly used for children with bronchiolitis, but its optimal role remains relatively uncertain. Our institution created and later revised a ward-based clinical pathway guiding initiation and weaning of HFNC. METHODS: A retrospective review of 664 encounters was conducted. Total duration of HFNC, duration of weaning from maximum flow rate, hospital length of stay (LOS), and escalation of care were compared across 3 study periods using generalized linear models: Baseline (HFNC managed at provider discretion, 5/1/2015-4/30/2017, n = 215), Intervention 1 (first pathway, initiation at 0.5 L/kg/min and escalation up to 2 L/kg/min, 5/1/2017-2/28/2018, n = 155), and Intervention 2 (revised pathway, initiation at the maximum rate of 2 L/kg/min, 3/1/2018-1/31/2020, n = 294). Both pathway iterations provided specific titration and weaning guidance. Models controlled for initial SpO2 and maximum respiratory rate to adjust for the possibility of differing case severity. RESULTS: After adjustment for severity, total duration of HFNC was significantly reduced in the second intervention, but not the first. Adjusted LOS was shorter in Intervention 1 and Intervention 2 compared to the baseline period. Adjusted weaning time and escalation of care did not differ significantly between periods. CONCLUSION: Pathway implementation was associated with modestly decreased LOS and – when initial flow rates were increased to 2 L/kg/min – reduced duration of HFNC, without differences in escalation of care or weaning time. These findings highlight the potential role of standardization of practice with clinical pathways in safely reducing unnecessary care.

Infarct Size, Imaging Features and Stroke Types with Different Clinical Types of Anterior Choroidal Artery Blood Supply Area Infarction

In this paper, we investigate the initial and boundary value problem of a planar magnetohydrodynamic system with temperature-dependent coefficients of transport, heat conductivity, and magnetic diffusivity coefficients. When all of the relative coefficients are exponentially related to the temperature, the existence and uniqueness of the global-in-time non-vacuum strong solutions are proven under some special assumptions. At the same time, the nonlinearly exponential stability of the solutions is obtained. In fact, the initial data could be large if the positive growth exponent of viscosity is small enough.

Background: Early cardiovascular impairment in obstructive sleep apnea (OSA) patients is often overlooked, leading to irreversible outcome. Left ventricular (LV) global longitudinal strain (GLS) derived from automated function imaging (AFI) echocardiography provides a fast tool to assess global longitudinal function. We therefore aimed to compare the feasibility and reproducibility of AFI with mitral annulus plane systolic excursion (MAPSE) as obesity is common in OSA. Methods: A comprehensive echocardiographic examination was done in 186 consecutive patients having polysomnography for suspected OSA in this prospective study. MAPSE was measured by using M-mode. AFI was derived by offline analysis of three long-axis views that semi-automatically detects LV endocardial boundary, which is adjusted manually as necessary. Variability of AFI and MAPSE were compared among the different subgroups and further tested in BMI subgroups. Results: Despite a relatively high obesity rate (42.9%), AFI was feasible in 94% (175/186) patients and MAPSE could be recorded in all patients. Although more segments were measured with AFI it showed excellent correlation (r=0.882) superior to MAPSE (r=0.819) between the expert and beginner. Intra- and inter- observer variability of AFI were comparable with MAPSE in Bland-Altman analysis, 5.5% and 6.5% for AFI, 6.2% and 8.8% for MAPSE, respectively. In repeated measurements, AFI showed higher intra-class correlation (ICC=0.95) than MAPSE (ICC=0.87). Furthermore, analysis showed that AFI was feasible even in more obese patients (BMI≥28kg/m2). Conclusions: Even in obese patients with OSA, AFI-GLS is feasible and more reliable for less expert operators than MAPSE for detecting LV longitudinal dysfunction.

Glaucoma is the second leading cause of irreversible blindness in the world according to the World Health Organization. It is characterized by the progressive degeneration of the optic nerve and despite the significant advances in the field, a cure for glaucoma remains to be found. The trabecular meshwork (TM) has been identified as the key tissue that drives pressure regulation in eye. In this review, we look over the main role of the aforementioned meshwork, as well as its outflow physiology and pathology. Research in the field of glaucoma has mostly progressed by employing animal models. However, these models are often expensive, cumbersome and exhibit a high intra-species variability. The lack of 3D in vitro models complicates the study of TM pressure regulation mechanisms, which makes it difficult to make progress in glaucoma research. In this paper, we review the time evolution of glaucoma models and discuss the ways in which tissue engineering fabrication techniques can be applied to create an artificial TM that serves as a 3D in vitro model. We also study possible outflow evaluation systems that are valid for both scaffold testing and drug screening, which may improve the understanding of TM biology.

A patient presenting with low back pain received 18 novel treatments of FDA approved low frequency sound wave stimulation known as Khan Kinetic Treatment (KKT). Following KKT he demonstrated improvement in pain, function, quality of life, sleep, and trunk range of motion with no adverse events.

We would like to draw attention to the potential of immunomodulatory tetracyclines for severe COVID-19. The COVID-19 pandemic is having a devastating impact on developing countries. A successful approach to manage the scarcity of cost-effective therapies worldwide is drug repurposing. Predictions of direct anti-viral activity of tetracyclines against SARS-CoV2 have been confirmed experimentally. Furthermore, their effectiveness in experimental ARDS has been proven extensively, counteracting the overt inflammatory reaction and fibrosis sequelae due to a synergic combination of pharmacological activities. Finally, a few clinical reports have confirmed their potentiall in COVID-19 patients, encouraging the development of this novel indication. We believe that the benefits of their multi-target pharmacology and their safety profile place immunomodulatory tetracyclines as gold repurposing candidates for COVID-19.

Plant physiological thresholds, based on the response of plant physiological parameters to soil available water, were proposed to optimize soil drought and desiccation studies. However, further research is lacked to explore the discrepancy between plant physiological thresholds and traditional threshold, stable field capacity (SFC), in prolong drought modelling. This discrepancy may misjudge the occurrence and severity of dry soil layer (DSL) and bring uncertainty to vegetation selection and planting years estimation. In this study, Environment Policy Integrated Climate (EPIC) model was used to predict soil water dynamics and drought yield loss (YL) in apple main production zone on the Chinese Loess Plateau from 2021 to 2080 under four General Circulation Models (GCMs). Subsequently, plant physiological thresholds were determined with leaf net photosynthetic (TPN) and transpiration rate (TTR) and compared with SFC in long-term DSL prediction. The present results showed that TPN and TTR significantly slowed down the formation of DSL and enhanced the correlation between DSL and YL. Forming serious DSL (Quantitative Index, QI > 0.5) has slowed from 20 to 30 years, and R2 of YL and QI increase from 0.265 to 0.528 (QIPN) and 0.409 (QITR). Moreover, future climate change accumulatively reduced 9.95-14.18% of the YL. These results indicated that traditional method overestimated the environmental contradiction between economic benefits and eco-hydrology of apple forests, which could bring unreliable messages to policymaker to restrict further development of apple industries. This study was emphasized that evaluating DSL based on plant physiological threshold reflected better plant growth and water stress, which contributed to further study the sustainable development of fragile ecosystem.

Agricultural land use can increase runoff and erosion leading to detrimental downstream impacts. This paper examines the impact of agricultural land cover change on runoff and sediment generation at event scales using a model-based approach. SHETRAN, a physically based, spatially distributed model, was applied in two southwest England catchments to represent: (a) changes in the land cover (cropland extent and spatial arrangement), (b) changes in crop type, and (c) use of riparian buffer strips. A total of 84 simulated events within a 4-year period were used to quantify flow and sediment generation impacts. We found past changes in land cover resulted in significant differences in sediment yield (p < 0.05). Linear regression showed an increase in flow and sediment yield proportional to increases in arable crop area (p < 0.001). The spatial arrangement of cropped fields and riparian buffer strips produced no significant differences in event flow or sediment yield (p > 0.05). However, buffer strip scenarios compared with the base run showed sediment load reductions in specific events, up to 20% and 15% for woodland and grass riparian buffers, respectively. When comparing crop types with and without the use of post-harvest cover crops, we observed non-significant differences (both Qv and Sy). However, large reductions in modelled sediment yields occurred for some events (e.g., up to 60% for winter cereals, 50% for maize and 74% for spring cereals). For these scenarios, examination of rainfall event magnitude emphasized the importance of ground cover in mitigating soil erosion for maize and spring cereals, but not for winter cereals. Our findings indicate that significant changes in sediment delivery at the event scale are associated with cropland extent and crop types, depending on rainfall magnitude, but not on the spatial arrangement of cropped fields or the use of riparian buffer strips.

Potential protective effects of breast milk and amniotic fluid against novel coronavirus SARS-CoV-2.Authors: April Rees1, Stephen Turner2, Catherine Thornton1*1 Institute of Life Science, Swansea University Medical School, Swansea, Wales, UK, SA2 8PP2 University of Aberdeen, The Institute of Applied Health Sciences, Aberdeen, Scotland, UK AB24 3FXDisclosure: The authors report no conflict of interest.Funding: This work was supported by the EPSRC Impact Acceleration Account at Swansea University and the Welsh Government Sêr Cymru III Tackling COVID-19 initiative.*Corresponding author:Professor Cathy ThorntonILS1, Swansea University Medical SchoolSingleton CampusSwansea UniversitySwansea, Wales, UKSA2 8PPTelephone: 01792 602122Email: c.a.thornton@swansea.ac.ukKeywords: Breast milk, amniotic fluid, SARS-CoV-2, neonateWord count: 769

The yeast Torulaspora delbrueckii is gaining importance for biotechnology due to its ability to increase wine sensorial complexity and for enhancing pre-frozen bread dough leavening. However, little is known about its population structure, variation in gene content, or possible domestication routes. Here, we address these issues and update the delimitation of T. delbrueckii along five major clades. Among the three European clades, a basal lineage is associated with the wild arboreal niche, while the two other lineages are linked with anthropic environments, one to wine fermentations and the other to diverse sources including dairy products and bread dough (Mix- Anthropic clade). Using 62 genomes we identified 5629 genes in the pangenome of T. delbrueckii and 270 genes in the cloud genome. A pangenome tree analysis showed that wine strains have a genome composition more similar to European wild arboreal strains than to those of the Mix Anthropic clade, in contradiction with the phylogenetic analysis. An association of gene content and ecology gave further support to the hypothesis that the Mix - Anthropic clade has the most specialized genome content and indicated that some of the exclusive genes were implicated in galactose and maltose utilization. More detailed analyses traced the acquisition of a cluster of GAL genes in strains associated with dairy products and the expansion and functional diversification of MAL genes in strains isolated from bread dough. Contrary to S. cerevisiae, domestication in T. delbrueckii is not primed by alcoholic fermentation and appears to be a recent event.

Pulmonary artery pseudoaneurysms are a rare but potentially lethal diagnosis. They can be further categorized by etiology or location and are typically successfully treated with endovascular therapies. However, they occasionally require operative intervention. Here, we present a case of a patient who presented with a central pulmonary artery pseudoaneurysm on CT scan with unclear etiology that was initially treated with conservative management. However, this was noted to have rapid enlargement on interval imaging necessitating urgent surgical intervention. The patient underwent a median sternotomy, anterior pulmonary artery arteriotomy for exposure, exclusion of the posterior artery pseudoaneurysm with a bovine pericardial patch, and closure of the anterior arteriotomy with a bovine pericardial patch. The patient did well and was discharged on postoperative day eleven with repeat imaging showing resolution.

Objectives: To evaluate the management practices and outcomes in children with sinogenic intracranial suppuration. Design: Retrospective cohort study. Setting: A single paediatric tertiary unit. Participants: Patients younger than 18 years with radiologically confirmed intracranial abscess including subdural empyema (SDE), epidural (EDA) or intraparenchymal (IPA) abscess secondary to sinusitis. Main outcome measures: The rates of return to theatre, the length of hospital stay (LOS), death <90 days and neurological disability (ND) at 6 months. Results: A cohort of 39 consecutive patients (41% male, mean age 11.5) presenting between 2000-2020 were eligible for inclusion. SDE was the most common intracranial complication (n=25, 64%) followed by EDA (n=12, 31%) and IPA (n=7, 18%). The mean LOS was 42 days (SD 16). Sixteen patients (41%) were managed with combined ENT and neurosurgical interventions, 15 (38.5%) underwent ENT procedure alone and 4 (10.3%) had neurosurgical only drainage. Four patients initially underwent non-operative management. The rates of return to theatre, ND and 90-day mortality were 19 (48.7%), 9 (23.1%) and 3 (7.7%) respectively and were comparable across the four treatment arms. In the univariate logistic regression, only the size of an intracranial abscess (10mm) was found be associated with an increased likelihood of return to theatre (odds radio 7, confidence interval 1.09-45.1), while combined ENT and neurosurgical intervention did not result in improved outcomes. Conclusion: Sinogenic intracranial abscesses are associated with a significant morbidity and mortality. The size of an intracranial abscess has a strong association with a need for a revision surgery.

Usually, adaptive phenotypic differentiation is paralleled by genetic divergence between locally adapted populations. However, adaptation can also happen in a scenario of non-significant genetic divergence due to intense gene flow and/or recent differentiation. While this phenomenon is rarely published, findings on incipient ecologically-driven divergence or isolation by adaptation are relatively common, which could confound our understanding about the frequency at which they actually occur in nature. Here, we explore genome-wide traces of divergence between two populations of the lacertid lizard Psammodromus algirus separated by a 600 m elevational gradient. These populations seem to be differentially adapted to their environments despite showing low levels of genetic differentiation (according to previously studies of mtDNA and microsatellite data). We performed a search for outliers (i.e. loci subject to selection) trying to identify specific loci with FST statistics significantly higher than those expected on the basis of overall, genome-wide estimates of genetic divergence. We find that local phenotypic adaptation (in terms of a wide diversity of characters) was not accompanied by genome-wide differentiation, even when we maximized the chances of unveiling such differentiation at particular loci with FST-based outlier detection tests. Instead, our analyses confirmed the lack of differentiation on the basis of more than 70,000 SNPs, which is concordant with a scenario of local adaptation without any degree of isolation by environment. Our results add evidence to previous studies in which local adaptation does not lead to any kind of isolation (or early stages of ecological speciation), but maintains phenotypic divergence despite the lack of a differentiated genomic background.

The fishing cat Prionailurus viverrinus is a wetland specialist endemic to South and Southeast Asia. Nepal represents the northern limit of its biogeographic range, but comprehensive information on fishing cat distribution in Nepal is lacking. We compiled fishing cat occurrence records (n=154) from Nepal, available in published literature and unpublished data (2009 – 2020), to assess their distribution. Bioclimatic and environmental variables associated with their occurrence were used to predict the potential fishing cat range using MaxEnt modeling. Fishing cat distribution was influenced by elevation, precipitation of the warmest quarter (18_bio), precipitation of the driest month (14_bio) and land cover. Wetlands and forest cover were the important predictors of fishing cat distribution. The model predicted an area of 4.4% (6,679 km2) of Nepal as potential habitat for the fishing cat. About two third of the predicted potentially suitable habitat lies outside protected areas, however a large part of the highly suitable habitat (67%) falls within protected areas. The predicted habitat map serves as a reference for future investigation into fishing cat distribution as well as formulating and implementing effective conservation programs for fishing cats in Nepal. Fishing cat conservation initiatives should include habitats both inside and outside the protected areas to ensure long-term survival. We recommend conservation of wetland sites, surveys of fishing cats in the identified potential habitats, and study of their genetic connectivity and population status.

The collection of animal position data via GPS tracking devices has increased in quality and usage in recent years. Animal position and movement, although measured discretely, follows the same principles of kinematic motion, and as such, the process is inherently continuous and differentiable. I demonstrate the functionality and visual elegance of smoothing spline models. I discuss the challenges and benefits of implementing such an approach, and I provide an analysis of movement and social interaction of seven jaguars inhabiting the Taiamã Ecological Station, Pantanal, Brazil. In the analysis, I derive measures for pairwise distance, cooccurence and spatiotemporal associaton between jaguars, borrowing ideas from density estimation and information theory. These measures are feasible as a result of spline model estimation, and they provide a critical tool for a deeper investigation of cooccurence duration, frequency, and localized spatio-temporal relationships between animals.

Describing the pattern and variations in spatial pattern of biodiversity and revealing its underlying mechanisms remain a central focus in ecology. However, less attention was paid to the species range size, and few studies have explored the drivers of species range size and the relationship between species range size and species richness (rescue effect). Here, we use a comprehensive dataset of breeding birds collected from 2018 to 2019 along the elevational gradient in Lebu Valley, Eastern Himalayas of China to explore the a) species mean elevational range size pattern, b) drivers influencing species mean elevational range size, and c) rescue effect. We found that species mean elevational range size of birds in Lebu Valley was a hump-shaped pattern (species mean elevational range size was largest at middle elevations), and the annual temperature range and normalized vegetation index were the most important explanatory variables for the species mean elevational range size pattern. However, species mean elevational range size was negatively correlated with the annual temperature range and positively correlated with the normalized vegetation index, respectively. These results were contrary to the predictions of the climate variability hypothesis and the ambient energy hypothesis. In addition, the correlation between species mean elevational range size and habitat heterogeneity was weak, which indicated that the habitat heterogeneity hypothesis also failed to predict the breeding bird mean elevational range size pattern in Lebu Valley. Moreover, we found the hump-shaped species richness pattern, which could also be resulted from non-directional rescue effect. Given the uncertainty in mean elevational range size pattern and the fact that much of the previous research has rarely tested the relationship between species range size and richness patterns, hypotheses explaining the elevational range size and the underlying mechanisms should be tested in more studies of different taxa and regions.