bluuebunny/crossref_metadata_2025 huggingface dataset:
Carbon stock estimation of mangrove forest in Sulaman Lake Forest Reserve, Sabah, Malaysia
Authors: Awang Besar Normah , SUHAILI NURUL SYAKILAH , FEI JIM LIEW JUN , SHA’ARI FAUZAN WAJDI , IDRIS MUHAMMAD IZZUDDIN , HATTA SYAHRIR MHD , KODOH JULIUS , BESAR NORMAH AWANG
Published: December 2020

Abstract. Besar NA, Suhaili NS, Fei JLJ, Sha’ari FW, Idris MI, Hatta SH, Kodoh J. 2020. Carbon stock estimation of Sulaman Lake Forest Reserve in Sabah, Malaysia. Biodiversitas 21: 5657-5664. Mangrove forest has a significant role in sequestering carbon gases from the atmosphere but there are lesser literature has been made on it. This research was conducted to quantify the aboveground, belowground and soil carbon stock in Sulaman Lake Forest Reserve, Sabah, Malaysia. Nine transect lines with 125 m length were established and a circle with 7 m radius was set in every 25 m. Forest inventory was done to get the diameter breast height of standing trees and soil sampling with four different depths (0-15 cm, 15-30 cm, 30-50 cm and 50-100 cm) were taken for soil analysis and bulk density. Allometric equation was used to calculate aboveground and belowground biomass then its carbon stock was estimated as 50% from its total biomass. The result shows the total carbon stock in the study area was 441.72 Mg C ha-1, and soil has the highest value of carbon stock (351.98 ± 11.73 Mg C ha-1) followed by aboveground carbon (67.30 ± 20.55 Mg C ha-1) and belowground carbon (22.44 ± 0.17 Mg C ha-1). This study found that soil carbon stock made up almost 80% of the total carbon stock in the mangrove forest. This ecosystem also shows a higher value of carbon stock compared to other locations hence emphasized the importance of prioritizing a mangrove forest in any climate mitigation efforts.
Pollen Sources Used by Tetragonisca angustula (Latreille, 1811) (Apidae, Meliponini) in the Atlantic Forest, Northern Coast of Bahia
Authors: Bastos Brenna Pinheiro , Lima Luciene Cristina Lima e , Dórea Marcos da Costa
Published: December 2020

Stingless bees are important floral visitors in tropical ecosystems and through pollination, play a key role in maintaining biodiversity and perpetuating native plant species. In this context, knowledge about the flora used by stingless bees is essential to promote their conservation in natural environments. This study had the objective of analyzing the pollen stored by Tetragonisca angustula (Latreille, 1811) in an Atlantic Forest area. A total of 27 pollen samples were collected from six colonies from April 2013 to March 2014. The samples were processed using acetolysis, in which pollen types were identified, photomicrographs and their frequency values were estimated. The most representative pollen types had their pollen morphology described. The analysis of the pollen sediment revealed 53 pollen types, three of which were indeterminate and the others belonged to 26 families. Among the registered pollen types, only 13 (distributed in ten families) showed frequency values over 10% in the analyzed samples, in which the majority presented a pollen morphology classified as microreticulated and tricolporate small monads. The pollen types Byrsonima (with frequency between 0.05 to 82.79%, which was recorded throughout the entire study period), Tapirira guianensis (0.92 to 55.65%), and Cecropia (0.24 to 49.32%), stood out as an important source of trophic resources for the maintenance and survival of T. angustula in an Atlantic Forest area. In addition, this study highlights the importance of palynological analysis for the knowledge of trophic resources used by stingless bees.
Canopy and Litter Cover Do Not Alter Diaspore Removal by Ants in the Cerrado
Authors: Rabelo Mariana Azevedo , Angotti Marina Acero , Silva Graziele Santiago , Reis Ariel da Cruz , Ribas Carla Rodrigues
Published: December 2020

Diaspore removal by ants is a crucial stage for successful myrmecochory and can be directly or indirectly affected by natural or anthropic changes to environments. Among the consequences of such changes is variation in habitat attributes, such as changes in conditions and resources and, consequently, decreased diaspore removal or even the loss of this ecological function. The aim of this study was to assess whether canopy and litter cover affect diaspore removal by ants in the Cerrado. We considered canopy and litter cover as proxies of humidity and temperature and evaluated whether changes in these environmental conditions could affect diaspore removal by ants. We hypothesized that the greater the canopy and litter cover (higher humidity and lower temperature), the greater the number of diaspores removed by ants. We tested this hypothesis by establishing three classes of cover for each proxy: low, intermediate, and high. We placed artificial diaspores under each cover class and quantified the number of diaspores removed. We found that variation in canopy and litter cover did not affect the number of diaspores removed by ants in areas of cerrado sensu stricto. Variation in habitat attributes in natural environments were less important for diaspore removal than in modified areas. Our results indicate that understanding the processes and habitat atributes involved in diaspore removal by ants is important for conserving the Cerrado.
Occurrence of Leaf-Cutting and Grass-Cutting Ants of the Genus Atta (Hymenoptera: Formicidae) in Geographic Regions of Brazil
Authors: Forti Luiz Carlos , Rando Jael Santos , Camargo Roberto da Silva , Moreira Aldenise Alves , Castellani Maria Aparecida , Leite Suzany Aguiar , Sousa Kátia Kaelly Andrade , Caldato Nadia
Published: December 2020

Leaf-cutting ants are widely distributed in Brazil, particularly species of the genus Atta. We therefore described the occurrence of leaf-cutting and grass-cutting ant species of the genus Atta. Five routes comprising some of the main highways in the South, Southeast, Center-West, and North of Brazil were sampled, in addition to ants received from other 82 municipalities, composing 300 municipalities sampled. This is the first comprehensive study of Atta in Brazil. The following species were found: A. laevigata, A. capiguara, A. sexdens rubropilosa, A. sexdens piriventris, A. sexdens sexdens and A. cephalotes. Atta laevigata and A. capiguara were the species present in the largest number of the Brazilian municipalities sampled. Atta laevigata assumed the position of species of greatest occurrence in the Brazilian territory. Atta sexdens piriventris was only recorded in the southern region of Brazil. Atta bisphaerica presented lower expansion than A. capiguara. Atta cephalotes and Atta opaciceps are species of very restricted occurrence. Southeastern region was characterized by the occurrence of A. capiguara and A. laevigata. Atta laevigata exhibited a generalized pattern of occurrence in the Center-West and North. Our study contributes to a better understanding of the so far unknown occurrence of leaf-cutting and grass-cutting ants within Brazil.
Karyotypic data of five ant taxa from the Brazilian Atlantic rainforest
Authors: Teixeira Gisele Amaro , Barros Luísa Antônia Campos , Lopes Denilce Meneses , Aguiar Hilton Jeferson Alves Cardoso de
Published: December 2020

The Brazilian Atlantic rainforest is an endangered biome and biodiversity hotspot. Ant cytogenetic studies from this biome showed remarkable chromosomal diversity among species, and provided useful insights on phylogeny, chromosomal evolution, and taxonomy. In this study, we karyotyped five ant taxa from the Atlantic rainforest. The karyotypes observed were Pheidole germaini 2n=22, Pheidole sp. flavens group 2n=20, Brachymyrmex admotus 2n=18, Camponotus atriceps 2n=40, and Odontomachus haematodus 2n=44. The data obtained for Pheidole spp. represent the first chromosomal record for the genus in Brazil and provide insights on the chromosomal evolution of P. germaini. Karyotypic information from B. admotus brings the genus back to the cytogenetic scenario after decades of neglect. No karyotype variations were observed among the C. atriceps and O. haematodus from different already studied populations, corroborating their status as good species. This study increased the cytogenetic knowledge of ants from the Brazilian Atlantic rainforest.
Comparative study of autofluorescence in flat and tapered optical fibers towards application in depth-resolved fluorescence lifetime photometry in brain tissue
Authors: Bianco Marco , Balena Antonio , Pisanello Marco , Pisano Filippo , Sileo Leonardo , Spagnolo Barbara , Montinaro Cinzia , Sabatini Bernardo L. , Vittorio Massimo De , Pisanello Ferruccio
Published: December 2020

As the scientific community seeks efficient optical neural interfaces with sub-cortical structures of the mouse brain, a wide set of technologies and methods is being developed to monitor cellular events through fluorescence signals generated by genetically encoded molecules. Among these technologies, tapered optical fibers (TFs) take advantage of the modal properties of narrowing waveguides to enable both depth-resolved and wide-volume light collection from scattering tissue, with minimized invasiveness with respect to standard flat fiber stubs (FFs). However, light guided in patch cords as well as in FFs and TFs can result in autofluorescence (AF) signal, which can act as a source of time-variable noise and limit their application to probe fluorescence lifetime in vivo. In this work, we compare the AF signal of FFs and TFs, highlighting the influence of the cladding composition on AF generation. We show that the autofluorescence signal generated in TFs has a peculiar coupling pattern with guided modes, and that far-field detection can be exploited to separate functional fluorescence from AF. On these bases, we provide evidence that TFs can be employed to implement depth-resolved fluorescence lifetime photometry, potentially enabling the extraction of a new set of information from deep brain regions, as time-correlating single photon counting starts to be applied in freely-moving animals to monitor the intracellular biochemical state of neurons.
Application driven assessment of probe designs for Raman spectroscopy
Authors: Pence Isaac J. , O’Brien Christine M. , Masson Laura E. , Mahadevan-Jansen Anita
Published: December 2020

In vivo Raman spectroscopy has been utilized for the non-invasive, non-destructive assessment of tissue pathophysiology for a variety of applications largely through the use of fiber optic probes to interface with samples of interest. Fiber optic probes can be designed to optimize the collection of Raman-scattered photons from application-dependent depths, and this critical consideration should be addressed when planning a study. Herein we investigate four distinct probe geometries for sensitivity to superficial and deep signals through a Monte Carlo model that incorporates Raman scattering and fluorescence. Experimental validation using biological tissues was performed to accurately recapitulate in vivo scenarios. Testing in biological tissues agreed with modeled results and revealed that microlens designs had slightly enhanced performance at shallow depths (< 1 mm), whereas all of the beampath-modified designs yielded more signal from deep within tissue. Simulation based on fluence maps generated using ray-tracing in the absence of optical scattering had drastically different results as a function of depth for each probe compared to the biological simulation. The contrast in simulation results between the non-scattering and biological tissue phantoms underscores the importance of considering the optical properties of a given application when designing a fiber optic probe. The model presented here can be easily extended for optimization of entirely novel probe designs prior to fabrication, reducing time and cost while improving data quality.
Quantum theory of Rayleigh scattering
Authors: Vinogradov A. P. , Shishkov V. Yu. , Doronin I. V. , Andrianov E. S. , Pukhov A. A. , Lisyansky A. A.
Published: December 2020

We suggest a quantum description of Rayleigh light scattering on atoms. We show that an entangled state of the excited atom and the incident photon is formed during the scattering. Due to entanglement, a photon is never completely absorbed by the atom. The formation of the scattering spectrum is considered as a relaxation of incident photons to the reservoir of free space modes that are in thermal equilibrium. Additional excitations of the reservoir modes occurring during scattering are treated as scattered light. We show that even if the frequency of incident photons is incommensurate with an atomic transition frequency, the scattered light spectrum has a maximum at the frequency of incident photons. In addition, the linewidth of the scattered light is much smaller than that of the spontaneous emission of a single atom. Therefore, the process can be considered as elastic.
Optical sensor network interrogation system based on nonuniform microwave photonic filters
Authors: Xiao Dongrui , Shao Liyang , Wang Chao , Lin Weihao , Yu Feihong , Wang Guoqing , Ye Tao , Wang Weizhi , Vai Mang I
Published: December 2020

Based on the nonuniformly spaced microwave photonic delay-line filter technology, a new design of a generic optical fiber sensor network interrogation platform is proposed and demonstrated. Sensing information from different types of optical sensors embedded in filter taps is converted into the variations of delay time and amplitude of each filter tap individually. Information to be measured can be decoded from the complex temporal impulse response of the microwave photonic filter. As proof-of-concept, our proposed approach is verified by simulations and experimental demonstrations successfully. Four optical sensors of different types are simultaneously interrogated via inverse Fourier transform of the filter frequency response. The experiment results show good linearity between the variation of temporal impulse response and the variations of the twist, the lateral pressure, the transversal loading and the temperature. The sensitivity of the sensors in the proposed platform is −2.130×10−5 a.u/degree, 6.1039 ps/kPa, −1.9146×10−5 a.u/gram, and 5.1497 ps/°C, respectively. Compared to the conventional optical sensors interrogation system, the presented approach provides a centralized solution that works for different types of optical sensors and can be easily expanded to cover larger optical sensor networks.
Measuring the multilayer silicon based microstructure using differential reflectance spectroscopy
Authors: Huo Shuchun , Wang Hao , Hu Chunguang , Yao Chengyuan , Shen Wanfu , Hu Xiaodong , Hu Xiaotang
Published: December 2020

The yield of a large-area ultra-thin display panel depends on the realization of designed thickness of multilayer films of all pixels. Measuring the thicknesses of multilayer films of a single pixel is crucial to the accurate manufacture. However, the thinnest layer is reaching the sub-20nm level, and different layers feature remarkable divergence in thickness with similar optical constants. This turns to a key obstruction to the thickness characterization by optical spectroscopy. Based on the tiny differences in absorptivity, a fast method for measuring the film thickness in a single pixel is proposed which combines the layer number reducing model and micro-area differential reflectance spectroscopy. The lower layers can be considered as semi-infinite in the corresponding spectral range whose thickness is infinite in the fitting algorithm. Hence, the thickness of the upper layer is fitted in a simplified layer structure. For demonstration, a multilayer silicon microstructure in a single pixel, p-Si/a-Si/n-Si (10nm/950nm/50nm) on complex substrate, is measured. The light spot diameter is about 60 microns with measuring-time in 2 seconds. The measurement deviation is 3% compared by a commercial ellipsometer. To conclude, the proposed method realizes the layer number reduction for fitting multilayer thickness with large thickness difference and similar optical constants, which provides a powerful approach for multilayer microstructure characterizations.
Noise and pulse dynamics in backward stimulated Brillouin scattering
Authors: Nieves Oscar A. , Arnold Matthew D. , Steel M. J. , Schmidt Mikołaj K. , Poulton Christopher G.
Published: December 2020

We theoretically and numerically study the effects of thermal noise on pulses in backwards stimulated Brillouin scattering (SBS). Using a combination of stochastic calculus and numerical methods, we derive a theoretical model that can be used to quantitatively predict noise measurements. We study how the optical pulse configuration, including the input powers of the pump and Stokes fields, pulse durations and interaction time, affects the noise in the output Stokes field. We investigate the effects on the noise of the optical loss and waveguide length, and we find that the signal-to-noise ratio can be significantly improved, or reduced, for specific combinations of waveguide properties and pulse parameters.
3D integrated wavelength demultiplexer based on a square-core fiber and dual-layer arrayed waveguide gratings
Authors: Jiang Xinhong , Yang Zhifang , Liu Zexu , Dang ZhangQi , Ding Zhenming , Chang Qing , Zhang Ziyang
Published: December 2020

We present a 3D integrated wavelength demultiplexer using a square-core fiber (SCF) and matched dual-layer arrayed waveguide gratings (AWGs). The SCF works as a 3D fiber multimode interference device, which splits the input light into symmetric four spots. The spots are then coupled to a pitch-matched 4-waveguide network, each connecting an AWG. Interface waveguides are designed to improve the coupling efficiency between the SCF and the dual-layer chip. The four AWGs are designed with different central wavelengths and a large free spectral range (FSR) of 120 nm. To reach a small and uniform insertion loss among different channels, only the central channels of each AWG are used for demultiplexing. The device is fabricated on a polymer platform. The upper and lower layers of the chip are fabricated using the same photolithography mask but rotated 180° so that 4 different AWG designs can be mapped to a single chip. The measured transmission spectra of the four AWGs cover a bandwidth of 112 nm. The insertion loss variation is smaller than 1.4 dB. The designed device can find applications in fiber optic sensing, communication, and astronomy.
Direct observation of enhanced performance in suspended ReS2 photodetectors
Authors: Zhong Jiahong , Zeng Cheng , Yu Juan , Cao Lingkai , Ding Junnan , Liu Zongwen , Liu Yanping
Published: December 2020

Rhenium disulfide (ReS2) has emerged as a promising material for future optoelectric applications due to its extraordinary electrical, mechanical, and optoelectrical properties. However, the ReS2-based photodetectors are severely restricted by their slow response speed (>10 s). Here, we demonstrate a high-performance polarization-sensitive photodetector based on suspended ReS2. Such a transistor shows an n-type behavior with the mobility of about 14.1 cm2V−1s−1, an on/off ratio of 105, and a responsivity of 0.22 A/W. Benefitting from well-developed contact between Au and the ReS2 channel and reduced interface scattering from the Si substrate, the response time of the device can be as short as 83.5 and 325.3µs, respectively, which are three orders of magnitude faster than that reported earlier. Furthermore, the suspended ReS2 photodetector also has the capability to detect polarized light (Imax/Imin ≈ 1.4 at 532 nm) due to the robust in-plane anisotropy of the material. These findings offer an efficient approach for improving the performance of ReS2-based photodetectors.
Fiber-based angular filtering for high-resolution Brillouin spectroscopy in the 20-300 GHz frequency range
Authors: Rodriguez A. , Priya P. , Ortiz O. , Senellart P. , Gomez-Carbonell C. , Lemaître A. , Esmann M. , Lanzillotti-Kimura N. D.
Published: December 2020

Brillouin spectroscopy emerges as a promising non-invasive tool for nanoscale imaging and sensing. One-dimensional semiconductor superlattice structures are eminently used for selectively enhancing the generation or detection of phonons at few GHz. While commercially available Brillouin spectrometers provide high-resolution spectra, they consist of complex experimental techniques and are not suitable for semiconductor cavities operating at a wide range of optical wavelengths. We develop a pragmatic experimental approach for conventional Brillouin spectroscopy that can integrate a widely tunable excitation-source. Our setup combines a fibered-based angular filtering and a spectral filtering based on a rotating single etalon and a double grating spectrometer for sequential reconstruction of Brillouin spectra. This configuration allows probing confined acoustic phonon modes in the 20-300 GHz frequency range with excellent laser rejection and high spectral resolution. Remarkably, our scheme based on the excitation and collection of the enhanced Brillouin scattering signals through the optical cavity allows for better angular filtering with decreasing phonon frequency. It can be implemented for the study of cavity optomechanics and stimulated Brillouin scattering over broadband optical and acoustic frequency ranges.
Genome-scale reconstructions to assess metabolic phylogeny and organism clustering
Authors: Schulz Christian , Almaas Eivind
Published: December 2020

Approaches for systematizing information of relatedness between organisms is important in biology. Phylogenetic analyses based on sets of highly conserved genes are currently the basis for the Tree of Life. Genome-scale metabolic reconstructions contain high-quality information regarding the metabolic capability of an organism and are typically restricted to metabolically active enzyme-encoding genes. While there are many tools available to generate draft reconstructions, expert-level knowledge is still required to generate and manually curate high-quality genome-scale metabolic models and to fill gaps in their reaction networks. Here, we use the tool AutoKEGGRec to construct 975 genome-scale metabolic draft reconstructions encoded in the KEGG database without further curation. The organisms are selected across all three domains, and their metabolic networks serve as basis for generating phylogenetic trees. We find that using all reactions encoded, these metabolism-based comparisons give rise to a phylogenetic tree with close similarity to the Tree of Life. While this tree is quite robust to reasonable levels of noise in the metabolic reaction content of an organism, we find a significant heterogeneity in how much noise an organism may tolerate before it is incorrectly placed in the tree. Furthermore, by using the protein sequences for particular metabolic functions and pathway sets, such as central carbon-, nitrogen-, and sulfur-metabolism, as basis for the organism comparisons, we generate highly specific phylogenetic trees. We believe the generation of phylogenetic trees based on metabolic reaction content, in particular when focused on specific functions and pathways, could aid the identification of functionally important metabolic enzymes and be of value for genome-scale metabolic modellers and enzyme-engineers.
Moderate and intensive mechanical loading differentially modulate the phenotype of tendon stem/progenitor cells in vivo
Authors: Zhang Jianying , Nie Daibang , Williamson Kelly , McDowell Arthur , Hogan MaCalus V. , Wang James H-C.
Published: December 2020

To examine the differential mechanobiological responses of specific resident tendon cells, we developed an in vivo model of whole-body irradiation followed by injection of either tendon stem/progenitor cells (TSCs) expressing green fluorescent protein (GFP-TSCs) or mature tenocytes expressing GFP (GFP-TNCs) into the patellar tendons of wild type C57 mice. Injected mice were subjected to short term (3 weeks) treadmill running, specifically moderate treadmill running (MTR) and intensive treadmill running (ITR). In MTR mice, both GFP-TSC and GFP-TNC injected tendons maintained normal cell morphology with elevated expression of tendon related markers collagen I and tenomodulin. In ITR mice injected with GFP-TNCs, cells also maintained an elongated shape similar to the shape found in normal/untreated control mice, as well as elevated expression of tendon related markers. However, ITR mice injected with GFP-TSCs showed abnormal changes, such as cell morphology transitioning to a round shape, elevated chondrogenic differentiation, and increased gene expression of non-tenocyte related genes LPL, Runx-2, and SOX-9. Increased gene expression data was supported by immunostaining showing elevated expression of SOX-9, Runx-2, and PPARγ. This study provides evidence that while MTR maintains tendon homeostasis by promoting the differentiation of TSCs into TNCs, ITR causes the onset of tendinopathy development by inducing non-tenocyte differentiation of TSCs, which may eventually lead to the formation of non-tendinous tissues in tendon tissue after long term mechanical overloading conditions on the tendon.
Enhanced recovery programmes versus conventional care in bariatric surgery: A systematic literature review and meta-analysis
Authors: Al-Rubeaan Khalid , Tong Cindy , Taylor Hannah , Miller Karl , Nguyen Phan Thanh Thao , Ridley Christian , Steeves Sara , Marsh William
Published: December 2020

Background

With obesity prevalence projected to increase, the demand for bariatric surgery will consequently rise. Enhanced recovery programmes aim for improved recovery, earlier discharge, and more efficient use of resources following surgery. This systematic literature review aimed to evaluate the evidence available on the effects of enhanced recovery programmes after three common bariatric procedures: laparoscopic Roux-en-Y gastric bypass (LRYGB), laparoscopic sleeve gastrectomy (LSG), and one anastomosis gastric bypass (OAGB).

Methods

MEDLINE, Embase, the Cochrane Library and the National Health Service Economic Evaluation Database were searched for studies published in 2012–2019 comparing outcomes with enhanced recovery programmes versus conventional care after bariatric surgery in Europe, the Middle East and Africa. Data were extracted and meta-analyses or descriptive analyses performed when appropriate using R.

Results

Of 1152 screened articles, seven relevant studies including 3592 patients were identified. Six reported outcomes for 1434 patients undergoing LRYGB; however, as only individual studies reported on LSG and OAGB these could not be included in the analyses. The meta-analysis revealed a significantly shorter mean duration of hospital-stay for LRYGB enhanced recovery programmes than conventional care (mean difference [95% CI]: -1.34 days [-2.01, -0.67]; p<0.0001), supported by sensitivity analysis excluding retrospective studies. Meta-analysis found no significant difference in 30-day readmission rate (risk ratio [95% CI]: 1.39 [0.84, 2.28]; p = 0.2010). Complication rates were inconsistently reported by Clavien-Dindo grade, but descriptive analysis showed generally higher low-grade rates for enhanced recovery programmes; the trend reversed for high-grade complications. Reoperation rates were rarely reported; no significant differences were seen.

Conclusion

These results support enhanced recovery programmes allowing shorter inpatient stay without significant differences in readmission rate following LRYGB, although complication and reoperation rate comparisons were inconclusive. Further research is needed to fill current data gaps including the lack of studies on LSG and OAGB.
Developmental differences in children’s and adults’ use of geometric information in map-reading tasks
Authors: Otálora Yenny , Taborda-Osorio Hernando
Published: December 2020

Using maps effectively requires the ability to scale distances while preserving angle and orientation, the three properties of Euclidean geometry. The aim of the current study was twofold: first, to examine how the ability to represent and use these Euclidean properties changes with development when scaling maps in object-to-object relationships and, second, to explore the effects on the scaling performance of two variables of the array of objects, type of angular configuration and relative vector length. To this end, we tested seventy-five 4-, 6-, and 8-year-old children, as well as twenty-five adults, in a simple completion task with different linear and triangular configurations of objects. This study revealed important developmental changes between 4 and 6 years of age and between 8 years of age and adulthood for both distance and angle representation, while it also showed that the configuration variables affected younger and older children’s performances in different ways when scaling distances and preserving angles and orientation. This study was instrumental in showing that, from an early age, children are able to exploit an intrinsic system of reference to scale geometrical configurations of objects.
The prevalence of esophageal cancer after caustic and pesticide ingestion: A nationwide cohort study
Authors: Mu Han-Wei , Chen Chun-Hung , Yang Kai-Wei , Pan Chi-Syuan , Lin Cheng-Li , Hung Dong-Zong
Published: December 2020

Habits such as smoking and alcohol drinking and existing esophageal malfunction are considered the main risk factors for esophageal carcinogenesis. Caustic ingestion of acidic or alkaline agents or strong irritants can induce severe esophageal corrosive injury and increase esophageal cancer risk. We studied the relationship between esophageal carcinoma and acute detergent or pesticide poisoning by using nationwide health insurance data. Methodology/Principle findings: We compared a pesticide/detergent intoxication cohort (N = 21,840) and an age- and gender-matched control cohort (N = 21,840) identified from the National Health Insurance Research Database between 2000 and 2011. We used the multivariable Cox proportional model to determine esophageal carcinoma risk. The overall incidence density of esophageal cancer was 1.66 per 10,000 person-years in the comparison cohort and 4.36 per 10,000 person-years in the pesticide/detergent intoxication cohort. The corresponding adjusted hazard ratio (HR) for esophageal cancer was 2.33 (95% confidence interval [CI] = 1.41–3.86) in the pesticide/detergent intoxication cohort compared with the control cohort. Patients with corrosive and detergent intoxication did not have a higher risk of esophageal cancer (adjusted HR = 0.98, 95% CI = 0.29–3.33) than those without pesticide/detergent intoxication. However, patients with pesticide intoxication had a significantly higher risk of esophageal cancer (adjusted HR = 2.52, 95% CI = 1.52–4.18) than those without pesticide/detergent intoxication. Conclusion: In the present study, after adjusting for conventional risk factors, we observed that pesticide intoxication could exert substantial effects through increased esophageal cancer risk. However, patients with detergent intoxication may not have an increased risk of esophageal cancer.
Identifying common treatments from Electronic Health Records with missing information. An application to breast cancer
Authors: Zaballa Onintze , Pérez Aritz , Gómez Inhiesto Elisa , Acaiturri Ayesta Teresa , Lozano Jose A.
Published: December 2020

The aim of this paper is to analyze the sequence of actions in the health system associated with a particular disease. In order to do that, using Electronic Health Records, we define a general methodology that allows us to: (i) identify the actions in the health system associated with a disease; (ii) identify those patients with a complete treatment for the disease; (iii) and discover common treatment pathways followed by the patients with a specific diagnosis. The methodology takes into account the characteristics of the EHRs, such as record heterogeneity and missing information. As an example, we use the proposed methodology to analyze breast cancer disease. For this diagnosis, 5 groups of treatments, which fit in with medical practice guidelines and expert knowledge, were obtained.
Archaeology and contemporary death: Using the past to provoke, challenge and engage
Authors: Croucher Karina , Büster Lindsey , Dayes Jennifer , Green Laura , Raynsford Justine , Comerford Boyes Louise , Faull Christina
Published: December 2020

While death is universal, reactions to death and ways of dealing with the dead body are hugely diverse, and archaeological research reveals numerous ways of dealing with the dead through time and across the world. In this paper, findings are presented which not only demonstrate the power of archaeology to promote and aid discussion around this difficult and challenging topic, but also how our approach resulted in personal growth and professional development impacts for participants. In this interdisciplinary pilot study, archaeological case studies were used in 31 structured workshops with 187 participants from health and social care backgrounds in the UK, to explore their reactions to a diverse range of materials which documented wide and varied approaches to death and the dead. Our study supports the hypothesis that the past is a powerful instigator of conversation around challenging aspects of death, and after death care and practices: 93% of participants agreed with this. That exposure to archaeological case studies and artefacts stimulates multifaceted discourse, some of it difficult, is a theme that also emerges in our data from pre, post and follow-up questionnaires, and semi-structured interviews. The material prompted participants to reflect on their biases, expectations and norms around both treatment of the dead, and of bereavement, impacting on their values, attitudes and beliefs. Moreover, 87% of participants believed the workshop would have a personal effect through thinking differently about death and bereavement, and 57% thought it would impact on how they approached death and bereavement in their professional practice. This has huge implications today, where talk of death remains troublesome, and for some, has a near-taboo status–‘taboo’ being a theme evident in some participants’ own words. The findings have an important role to play in facilitating and normalising discussions around dying and bereavement and in equipping professionals in their work with people with advanced illness.
Which COVID policies are most effective? A Bayesian analysis of COVID-19 by jurisdiction
Authors: Wibbens Phebo D. , Koo Wesley Wu-Yi , McGahan Anita M.
Published: December 2020

This paper reports the results of a Bayesian analysis on large-scale empirical data to assess the effectiveness of eleven types of COVID-control policies that have been implemented at various levels of intensity in 40 countries and U.S. states since the onset of the pandemic. The analysis estimates the marginal impact of each type and level of policy as implemented in concert with other policies. The purpose is to provide policymakers and the general public with an estimate of the relative effectiveness of various COVID-control strategies. We find that a set of widely implemented core policies reduces the spread of virus but not by enough to contain the pandemic except in a few highly compliant jurisdictions. The core policies include the cancellation of public events, restriction of gatherings to fewer than 100 people, recommendation to stay at home, recommended restrictions on internal movement, implementation of a partial international travel ban, and coordination of information campaigns. For the median jurisdiction, these policies reduce growth rate in new infections from an estimated 270% per week to approximately 49% per week, but this impact is insufficient to prevent eventual transmission throughout the population because containment occurs only when a jurisdiction reduces growth in COVID infection to below zero. Most jurisdictions must also implement additional policies, each of which has the potential to reduce weekly COVID growth rate by 10 percentage points or more. The slate of these additional high-impact policies includes targeted or full workplace closings for all but essential workers, stay-at-home requirements, and targeted school closures.
Characterization of the secretory profile and exosomes of limbal stem cells in the canine species
Authors: Villatoro Antonio J. , Alcoholado Cristina , Martín-Astorga María del Carmen , Rico Gustavo , Fernández Viviana , Becerra José
Published: December 2020

Limbal stem cells (LSCs) are a quiescent cell population responsible for the renewal of the corneal epithelium. Their deficiency is responsible for the conjunctivization of the cornea that is seen in different ocular pathologies, both in humans and in the canine species. The canine species represents an interesting preclinical animal model in ocular surface pathologies. However, the role of LSCs in physiological and pathological conditions in canine species is not well understood. Our objective was to characterize for the first time the soluble factors and the proteomic profile of the secretome and exosomes of canine LSCs (cLSCs). In addition, given the important role that fibroblasts play in the repair of the ocular surface, we evaluated the influence of the secretome and exosomes of cLSCs on their proliferation in vitro. Our results demonstrated a secretory profile of cLSCs with high concentrations of MCP-1, IL-8, VEGF-A, and IL-10, as well as significant production of exosomes. Regarding the proteomic profile, 646 total proteins in the secretome and 356 in exosomes were involved in different biological processes. Functionally, the cLSC secretome showed an inhibitory effect on the proliferation of fibroblasts in vitro, which the exosomes did not. These results open the door to new studies on the possible use of the cLSC secretome or some of its components to treat certain pathologies of the ocular surface in canine species.
Automatically detecting bregma and lambda points in rodent skull anatomy images
Authors: Zhou Peng , Liu Zheng , Wu Hemmings , Wang Yuli , Lei Yong , Abbaszadeh Shiva
Published: December 2020

Currently, injection sites of probes, cannula, and optic fibers in stereotactic neurosurgery are typically located manually. This step involves location estimations based on human experiences and thus introduces errors. In order to reduce localization error and improve repeatability of experiments and treatments, we investigate an automated method to locate injection sites. This paper proposes a localization framework, which integrates a region-based convolutional network and a fully convolutional network, to locate specific anatomical points on skulls of rodents. Experiment results show that the proposed localization framework is capable of identifying and locatin bregma and lambda in rodent skull anatomy images with mean errors less than 300 μm. This method is robust to different lighting conditions and mouse orientations, and has the potential to simplify the procedure of locating injection sites.
Phase I trial of intracerebral convection-enhanced delivery of carboplatin for treatment of recurrent high-grade gliomas
Authors: Wang Joshua L. , Barth Rolf F. , Cavaliere Robert , Puduvalli Vinay K. , Giglio Pierre , Lonser Russell R. , Elder J. Bradley
Published: December 2020

Background

Carboplatin is a potent cytoreductive agent for a variety of solid tumors. However, when delivered systemically, clinical efficacy for the treatment of high grade gliomas is poor due to limited penetration across the blood-brain barrier (BBB). Direct intracerebral (IC) convection-enhanced delivery (CED) of carboplatin has been used to bypass the BBB and successfully treat the F98 rat glioma. Based on these studies, we initiated a Phase I clinical trial.

Objective

This Phase I clinical trial was conducted to establish the maximum tolerated dose and define the toxicity profile of carboplatin delivered intracerebrally via convection enhanced delivery (CED) for patients with high grade glial neoplasms.

Methods

Cohorts of 3 patients with recurrent WHO grade III or IV gliomas were treated with escalating doses of CED carboplatin (1–4 μg in 54mL over 72 hours) delivered via catheters placed at the time of recurrent tumor resection. The primary outcome measure was determination of the maximum tolerated dose (MTD). Secondary outcome measures included overall survival (OS), progression-free survival (PFS), and radiographic correlation.

Results

A total of 10 patients have completed treatment with infusion doses of carboplatin of 1μg, 2μg, and 4μg. The total planned volume of infusion was 54mL for each patient. All patients had previously received surgery and chemoradiation. Histology at treatment include GBM (n = 9) and anaplastic oligodendroglioma (n = 1). Median KPS was 90 (range, 70 to 100) at time of treatment. Median PFS and OS were 2.1 and 9.6 months after completion of CED, respectively. A single adverse event possibly related to treatment was noted (generalized seizure).

Conclusions

IC CED of carboplatin as a potential therapy for recurrent malignant glioma is feasible and safe at doses up to 4μg in 54mL over 72 hours. Further studies are needed to determine the maximum tolerated dose and potential efficacy.
Decomposition of changes in socioeconomic inequalities in catastrophic health expenditure in Kenya
Authors: Njagi Purity , Arsenijevic Jelena , Groot Wim
Published: December 2020

Background

Catastrophic health expenditure (CHE) is frequently used as an indicator of financial protection. CHE exists when health expenditure exceeds a certain threshold of household consumption. Although CHE is reported to have declined in Kenya, it is still unacceptably high and disproportionately affects the poor. This study examines the socioeconomic factors that contribute to inequalities in CHE as well as the change in these inequalities over time in Kenya.

Methods

We used data from the Kenya household health expenditure and utilisation (KHHEUS) surveys in 2007 and 2013. The concertation index was used to measure the socioeconomic inequalities in CHE. Using the Wagstaff (2003) approach, we decomposed the concentration index of CHE to assess the relative contribution of its determinants. We applied Oaxaca-type decomposition to assess the change in CHE inequalities over time and the factors that explain it.

Results

The findings show that while there was a decline in the incidence of CHE, inequalities in CHE increased from -0.271 to -0.376 and was disproportionately concentrated amongst the less well-off. Higher wealth quintiles and employed household heads positively contributed to the inequalities in CHE, suggesting that they disadvantaged the poor. The rise in CHE inequalities overtime was explained mainly by the changes in the elasticities of the household wealth status.

Conclusion

Inequalities in CHE are persistent in Kenya and are largely driven by the socioeconomic status of the households. This implies that the existing financial risk protection mechanisms have not been sufficient in cushioning the most vulnerable from the financial burden of healthcare payments. Understanding the factors that sustain inequalities in CHE is, therefore, paramount in shaping pro-poor interventions that not only protect the poor from financial hardship but also reduce overall socioeconomic inequalities. This underscores the fundamental need for a multi-sectoral approach to broadly address existing socioeconomic inequalities.
Estimating the impact of differential adherence on the comparative effectiveness of stool-based colorectal cancer screening using the CRC-AIM microsimulation model
Authors: Piscitello Andrew , Saoud Leila , Fendrick A. Mark , Borah Bijan J. , Hassmiller Lich Kristen , Matney Michael , Ozbay A. Burak , Parton Marcus , Limburg Paul J.
Published: December 2020

Background

Real-world adherence to colorectal cancer (CRC) screening strategies is imperfect. The CRC-AIM microsimulation model was used to estimate the impact of imperfect adherence on the relative benefits and burdens of guideline-endorsed, stool-based screening strategies.

Methods

Predicted outcomes of multi-target stool DNA (mt-sDNA), fecal immunochemical tests (FIT), and high-sensitivity guaiac-based fecal occult blood tests (HSgFOBT) were simulated for 40-year-olds free of diagnosed CRC. For robustness, imperfect adherence was incorporated in multiple ways and with extensive sensitivity analysis. Analysis 1 assumed adherence from 0%-100%, in 10% increments. Analysis 2 longitudinally applied real-world first-round differential adherence rates (base-case imperfect rates = 40% annual FIT vs 34% annual HSgFOBT vs 70% triennial mt-sDNA). Analysis 3 randomly assigned individuals to receive 1, 5, or 9 lifetime (9 = 100% adherence) mt-sDNA tests and 1, 5, or 9 to 26 (26 = 100% adherence) FIT tests. Outcomes are reported per 1000 individuals compared with no screening.

Results

Each screening strategy decreased CRC incidence and mortality versus no screening. In individuals screened between ages 50–75 and adherence ranging from 10%a-100%, the life-years gained (LYG) for triennial mt-sDNA ranged from 133.1–300.0, for annual FIT from 96.3–318.1, and for annual HSgFOBT from 99.8–320.6. At base-case imperfect adherence rates, mt-sDNA resulted in 19.1% more LYG versus FIT, 25.4% more LYG versus HSgFOBT, and generally had preferable efficiency ratios while offering the most LYG. Completion of at least 21 FIT tests is needed to reach approximately the same LYG achieved with 9 mt-sDNA tests.

Conclusions

Adherence assumptions affect the conclusions of CRC screening microsimulations that are used to inform CRC screening guidelines. LYG from FIT and HSgFOBT are more sensitive to changes in adherence assumptions than mt-sDNA because they require more tests be completed for equivalent benefit. At imperfect adherence rates, mt-sDNA provides more LYG than FIT or HSgFOBT at an acceptable tradeoff in screening burden.
The mechanisms behind perivascular fluid flow
Authors: Daversin-Catty Cécile , Vinje Vegard , Mardal Kent-André , Rognes Marie E.
Published: December 2020

Flow of cerebrospinal fluid (CSF) in perivascular spaces (PVS) is one of the key concepts involved in theories concerning clearance from the brain. Experimental studies have demonstrated both net and oscillatory movement of microspheres in PVS (Mestre et al. (2018), Bedussi et al. (2018)). The oscillatory particle movement has a clear cardiac component, while the mechanisms involved in net movement remain disputed. Using computational fluid dynamics, we computed the CSF velocity and pressure in a PVS surrounding a cerebral artery subject to different forces, representing arterial wall expansion, systemic CSF pressure changes and rigid motions of the artery. The arterial wall expansion generated velocity amplitudes of 60–260 μm/s, which is in the upper range of previously observed values. In the absence of a static pressure gradient, predicted net flow velocities were small (<0.5 μm/s), though reaching up to 7 μm/s for non-physiological PVS lengths. In realistic geometries, a static systemic pressure increase of physiologically plausible magnitude was sufficient to induce net flow velocities of 20–30 μm/s. Moreover, rigid motions of the artery added to the complexity of flow patterns in the PVS. Our study demonstrates that the combination of arterial wall expansion, rigid motions and a static CSF pressure gradient generates net and oscillatory PVS flow, quantitatively comparable with experimental findings. The static CSF pressure gradient required for net flow is small, suggesting that its origin is yet to be determined.