The Deepwater Horizon Oil Spill in the USA’s Gulf of Mexico created a high degree of exposure of marine organisms to toxic polyaromatic hydrocarbons (PAHs) present in crude oil. To determine the ecological and physio...The Deepwater Horizon Oil Spill in the USA’s Gulf of Mexico created a high degree of exposure of marine organisms to toxic polyaromatic hydrocarbons (PAHs) present in crude oil. To determine the ecological and physiological effects of crude oil on the Gulf of Mexico ecosystem, the Gulf of Mexico Research Initiative created several research consortia to address overreaching questions concerning the biological impacts of the ecology of the Gulf of Mexico that would otherwise be beyond the capabilities of an individual investigator or a small group. One of these consortia, highlighted in this article, is the RECOVER Consortium, which brings together physiologists, developmental biologists, toxicologists and other life scientists to focus on the multifaceted physiological effects of PAHs, especially as they pertain to cardiovascular and metabolic physiology of economically important fish species. Using the Recover Consortium’s interdisciplinary approach to revealing the biological impacts of the Deepwater Horizon Oil Spill as a case study, we make the argument for interdisciplinary teams that bring together scientists with different specialties as an efficient way—and perhaps the only way—to unravel highly complex biological effects of marine oil spills.展开更多
The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure t...The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments.展开更多
Congenital hyperinsulinism(CHI) is a rare but complex heterogeneous disorder caused by unregulated secre-tion of insulin from the β-cells of the pancreas leading to severe hypoglycaemia and neuroglycopaenia. Swift di...Congenital hyperinsulinism(CHI) is a rare but complex heterogeneous disorder caused by unregulated secre-tion of insulin from the β-cells of the pancreas leading to severe hypoglycaemia and neuroglycopaenia. Swift diagnosis and institution of appropriate management is crucial to prevent or minimise adverse neurodevel-opmental outcome in children with CHI. Histologically there are two major subtypes of CHI, diffuse and focal disease and the management approach will significantly differ depending on the type of the lesion. Patients with medically unresponsive diffuse disease require a near total pancreatectomy, which then leads on to the de-velopment of iatrogenic diabetes mellitus and pancre-atic exocrine insufficiency. However patients with focaldisease only require a limited pancreatectomy to re-move only the focal lesion thus providing complete cure to the patient. Hence the preoperative differentiation of the histological subtypes of CHI becomes paramount in the management of CHI. Fluorine-18L-3, 4-hydroxy-phenylalanine positron emission tomography(18F-DOPA-PET) is now the gold standard for pre-operative differentiation of focal from diffuse disease and locali-sation of the focal lesion. The aim of this review article is to give a clinical overview of CHI, then review the role of dopamine in β-cell physiology and finally discuss the role of 18F-DOPA-PET imaging in the management of CHI.展开更多
The interplay between glucose metabolism and that of the two other primary nutrient classes, amino acids and fatty acids is critical for regulated insulin secretion. Mitochondrial metabolism of glucose, amino acid and...The interplay between glucose metabolism and that of the two other primary nutrient classes, amino acids and fatty acids is critical for regulated insulin secretion. Mitochondrial metabolism of glucose, amino acid and fatty acids generates metabolic coupling factors(such as ATP, NADPH, glutamate, long chain acyl-CoA and diacylglycerol) which trigger insulin secretion. The observation of protein induced hypoglycaemia in patients with mutations in GLUD1 gene, encoding the enzyme glutamate dehydrogenase(GDH) and HADH gene, encoding for the enzyme short-chain 3-hydroxyacyl-CoA dehydrogenase has provided new mechanistic insights into the regulation of insulin secretion by amino acid and fatty acid metabolism. Metabolic signals arising from amino acid and fatty acid metabolism converge on the enzyme GDH which integrates both signals from both pathways and controls insulin secretion. Hence GDH seems to play a pivotal role in regulating both amino acid and fatty acid metabolism.展开更多
Objective: To examine the long-term effects of the Seattle Social Development Project intervention in promoting positive adult functioning and preventing men tal health problems, crime, and substance use (including to...Objective: To examine the long-term effects of the Seattle Social Development Project intervention in promoting positive adult functioning and preventing men tal health problems, crime, and substance use (including tobacco, alcohol, and o ther drugs) at 21 years of age. Design: This nonrandomized controlled trial followed up participants to 21 years of age, 9 years after the intervention ended. We compared the following 3 intervention con ditions: a full 6-year intervention (grades 1 through 6); a late 2-year interv ention (grades 5 and 6 only); and a no-treatment control condition. Setting: Ei ghteen public elementary schools serving diverse neighborhoods, including high- crime neighborhoods, of Seattle, Wash. Participants: A sex-balanced, multiethni c sample of 605 participants across the 3 conditions who completed interviews at 21 years of age (94%of the original sample in these conditions). Interventions : Teacher training in classroom instruction and management, child social and emo tional skill development, and parent training. Main Outcome Measures: Self-repo rts of functioning in school and work, emotional and mental health, and crime an d substance use at 21 years of age and official court records. Results: Broad si gnificant effects on functioning in school and work and on emotional and mental health were found. Fewer significant effects on crime and substance use were fou nd at 21 years of age. Most outcomes had a consistent dose effect, with the stro ngest effects in subjects in the full-intervention group and effects in the lat e-intervention group between those in the full-intervention and control groups . Conclusions: A theoryguided preventive intervention that strengthened teaching and parenting practices and taught children interpersonal skills during the ele mentary grades had wide-ranging beneficial effects on functioning in early adul thood.展开更多
Objective: To investigate the antiviral property of a lead ligand, YK51 that was synthesized based on the flavanoid of a natural product toward dengue virus type-2(DENV2)replication.Methods: c RNA was isolated from He...Objective: To investigate the antiviral property of a lead ligand, YK51 that was synthesized based on the flavanoid of a natural product toward dengue virus type-2(DENV2)replication.Methods: c RNA was isolated from HepG2 cells inoculated with 1 000 median tissue culture infective dose of DENV2 and treated with different doses of the ligand followed by RT-PCR to quantify the virus gene copies. Confocal microscopy of actin and tubulin redistribution was also performed.Results: The quantitative RT-PCR result showed reduction of the DENV2 gene copies as the ligand concentration was increased. The confocal microscopy result showed increase in the tubulin intensity(79.6%) of infected BHK21 cells treated with the ligand,compared with the non-treated cells(54.8%). The 1.5-fold increase in the intensity of tubulin suggested that the ligand inhibitory effect stabilized the cellular microtubule structure.Conclusions: The synthesized ligand YK51 reduced DENV2 viral load by inhibiting virus replication thus is highly potential to be developed as antiviral agent.展开更多
Secondary lignocellulosic biomass has proved to be useful as an energy source through its oxidation by means of combustion processes.In accordance with the above,in this paper,we wanted to study the ash from urban pru...Secondary lignocellulosic biomass has proved to be useful as an energy source through its oxidation by means of combustion processes.In accordance with the above,in this paper,we wanted to study the ash from urban pruning residues that are generated in cities in the Neotropics.Species such as Licania tomentosa,Azadirachta indica,Ficus benjamina,Terminalia catappa,Leucaena leucocephala,Prosopis juliflora and Pithecellobium dulce were selected because they have been previously studied and showed potential for thermal energy generation.These materials were calcined in an oxidizing atmosphere and characterized by X-ray diffraction and fluorescence,scanning electron microscopy with microchemistry,BET surface area,thermal gravimetric analysis,and differential scanning calorimetry.The pH and apparent density were also established.The results show high basicity materials(average pH 10),a behavior associated with the presence of chemical elements such as calcium,potassium,magnesium,chlorine,phosphorus,and sulfur.Structurally,these materials have a very significant amorphous fraction(between 49%and 74.5%),the dominant crystalline phases are calcite,arcanite,sylvite,and hydroxyapatite.These ashes have low surface area and do not exceed 13 m^(2)/g.Two characteristic morphological aspects were observed in these ashes:a morphology of rounded grains where silicon content is highlighted,and lamellar morphologies where the presence of chlorine is highlighted.Thermally,these ashes show four significant mass loss events(400℃,430℃,680℃,and 920℃),causing mass losses that vary between 25%and 40%.Through this study,it was possible to establish that,from a chemical point of view,these ashes are less dangerous in comparison with those of a mineral coal that was used as a reference.However,they require additional treatments for their disposal due to their high basicity.Because of their composition,these ashes have the potential to be used in the ceramic and cement industries,and in the manufacture of fertilizers.展开更多
The material associated with tree pruning in a city in the Colombian neotropics was characterized in order to determine its energy potential.The species studied for their relevance in the territory were Prosopis julif...The material associated with tree pruning in a city in the Colombian neotropics was characterized in order to determine its energy potential.The species studied for their relevance in the territory were Prosopis juliflora,Licania tomentosa,Terminalia catappa,Azadirachta indica,Pithecellobium dulce,Ficus benjamina and Leucaena leucocephala.Moisture content,bulk density,hygroscopic response,elemental chemical analysis,proximal analysis,calorific value,ease of ignition and combustion,thermogravimetric and heat flow analysis,steam generation capacity,and qualitative analysis of gases(mass spectrometry)were determined.The results that were obtained show high initial moisture contents that vary between 37%and 67%and a variable density(when dry)between 0.21 and 0.41 g/cm3.Chemically,it was shown that all residues have lower carbon and sulfur content compared to a reference mineral coal.However,the residues of some species have higher nitrogen contents compared to the same coal.All biomasses are characterized by their high content of volatile fractions and by having a lower content of inorganic matter compared to carbon.The lower calorific values of these residues are between 14170 and 16928 kJ/kg,which are not negligible compared to other biomasses.This characteristic would be related to the high presence of hemicellulose in the residues.Flue gas monitoring revealed that there are different airflow needs in order to ensure complete combustion.Steam generation tests showed that the calorific value should not be the most relevant criterion to establish the potential use of the waste,since leucaena leucocephala,despite having the highest calorific value,was the material with the lowest performance in steam generation.展开更多
Plasma X-ray sources for biological microscopy have been produced by focusing single shots from Nd:glass laser onto carbon rod targets at irradiances between 1 × 1013 W⋅cm−2 and 3 × 1013 W...Plasma X-ray sources for biological microscopy have been produced by focusing single shots from Nd:glass laser onto carbon rod targets at irradiances between 1 × 1013 W⋅cm−2 and 3 × 1013 W⋅cm−2 to expose test objects. The optimum parameters needed for obtaining high accurate information on the samples under test namely: the minimum energies and irradiances at a range of angles between the incoming laser beam and the normal to the resist, the depth of exposure of the photoresist as a function of incident laser energy (and irradiance) were concluded in this work.展开更多
In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution functi...In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution function.Recent studies have reported the argon-helium plasma and conducted a brief theoretical and experimental survey.To deepen our understanding further,this study aims to analyze the argon-helium plasma comprehensively using the same pattern but with the(r,q)-distribution function.For this purpose,the current balance equations are derived for electron,helium and argon ions,when these charge species attain the quasineutrality condition.We numerically examined the currents of plasma species for a broad range of effective distribution function parameters r and q.It is revealed that the surface potential of dust particles is significantly affected by the parameters r and q,helium ion-to-electron temperature ratio,argon ion-to-electron temperature ratio,and helium ion to argon ion number density ratio.By incorporating the multi-ion(argon-helium)species,the significance of low-temperature nonMaxwellian dusty(complex)plasma is briefly examined.展开更多
The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurr...The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurred.The ongoing surge in high-resolution data allows novel opportunities for quantification of hazards and exposure.Here,we provide a global spatial synthesis of urban populations'exposure to riverinefloods and storm surges in 1990 and 2015.Our results reveal that,owing to rapid economic development globally in a large proportion of exposed areas,most of the exposure has shifted from low-income to middle-income countries.Asia dominates as a continent.The total growth of human exposure continues,suggesting that disaster risk reduction policies and implementation call for enduring effort.展开更多
Purpose To determine the association between lower-body strength and lower-body power capacities with sprint swimming performance in adolescent competitive swimmers.Methods A total of 44 front crawl swimmers(27 males ...Purpose To determine the association between lower-body strength and lower-body power capacities with sprint swimming performance in adolescent competitive swimmers.Methods A total of 44 front crawl swimmers(27 males and 17 females)performed anthropometric assessments,lower-body strength tests(half squat maximum isometric strength,dynamic half squat with 20,30 and 40%of the maximum isometric strength,and knee extension maximum isometric strength)and lower-body power tests(squat jump[SJ],countermovement jump[CMJ]and Abalakov jump).Further front crawl swimming best times in 50 and 100 m were recorded from official swimming competitions and front crawl technique was assessed by an experienced coach using a visual analogue scale.Results Swimming performance was correlated with lower-body power variables(SJ[r=−0.573 for 50 m and−0.642 for 100 m],CMJ[r=−0.497 for 50 m and−0.544 for 100 m],and Abalakov jump[r=−0.452 for 50 m and−0.415 for 100 m];p≤0.05)and lower-body strength(half squat maximum isometric strength[r=−0.430 for 50 m and−0.443 for 100 m];p≤0.05)in males but not in females.Further linear regression models showed that only lower-body power predicted both 50 m(Abalakov jump;r^(2)=0.58;change in r^(2)=0.18)and 100 m(SJ;r^(2)=0.66;change in r^(2)=0.15)performance in male swimmers.Conclusions This study emphasizes the greater association between lower-body power and sprint front crawl performance in adolescent males compared to females.Practical tests(i.e.,SJ and Abalakov jump)are shown to predict front crawl swimming performance,which may facilitate the performance control by coaches and trainers.展开更多
Objectives The purpose of this study is to examine the effects of applying anodal tDCS(2 mA for 20 min)over the scalp from T3(anodal-tDCS)to Fp2(cathodal-tDCS)on the perceptual,physiological and performance responses ...Objectives The purpose of this study is to examine the effects of applying anodal tDCS(2 mA for 20 min)over the scalp from T3(anodal-tDCS)to Fp2(cathodal-tDCS)on the perceptual,physiological and performance responses during maximal incremental and constant-load exercise(CLE)in trained cyclists.Methods Eleven male cyclists performed maximal incremental exercise(MIE)on a cycle ergometer under either tDCS or sham,with power output,heart rate(HR),oxygen uptake(V̇O_(2)),ratings of perceived exertion(RPE)assessed throughout,and blood samples collected before and after MIE.On two separate occasions,nine subjects performed CLE at 62%of the peak power output followed by a 15 km time trial under either tDCS or sham(n=8 for the time trial).Results HR,V̇O_(2),RPE and blood samples were collected at regular intervals.There were no differences between tDCS and sham in any variable during the MIE.tDCS elicited a decreased HR(F_(4,8)=9.232;p=0.016;η_(p)^(2)=0.54),increased V̇O_(2)(F_(4,8)=8.920;p=0.015;η_(p)^(2)=0.50)and increased blood non-esterified fatty acids(F_(6,8)=11.754;p=0.009;η_(p)^(2)=0.60)and glycerol(F_(6,8)=6.603;p=0.037;η_(p)^(2)=0.49)concentrations during the CLE when compared to sham.tDCS also improved 15 km time trial performance by 3.6%(p=0.02;d=0.47)without affecting RPE,HR and blood lactate.Conclusions The application of tDCS over the temporal cortex in trained cyclists improved cycling performance during a self-paced time trial but did not enhance performance during maximal incremental exercise.These results are encouraging and merit further investigation of the ergogenic effects of tDCS in trained athletes.展开更多
Introduction:Runners from East Africa including Kenya,Ethiopia and Uganda have dominated middle-and longdistance running events,for almost six decades.This narrative review examines and updates current understanding o...Introduction:Runners from East Africa including Kenya,Ethiopia and Uganda have dominated middle-and longdistance running events,for almost six decades.This narrative review examines and updates current understanding of the factors explaining the dominance of East Africans in distance running from a holistic perspective.Content:The dominance of East African distance runners has puzzled researchers,with various factors proposed to explain their unparalleled success.Four key elements emerge:1)biomechanical and physiological attributes,2)training characteristics,3)psychological motivations,and 4)African diet.Runners from East Africa often exhibit ectomorphic somatotypes,characterized by lean body compositions which lead them to an extraordinary biomechanical and metabolic effciency.Their sociocultural lifestyle,training regimens beginning at a young age with aerobic activities,seem crucial,as well as moderate volume,high-intensity workouts at altitudes ranging from 2,000 to 3,000 m.Psychological factors,including a strong motivation to succeed driven by aspirations for socioeconomic improvement and a rich tradition of running excellence,also contribute significantly.A multifactorial explanation considering these factors,without a clear genetic influence,is nowadays the strongest argument to explain the East African phenomenon.Summary and outlook:To unravel the mystery behind the supremacy of East African runners,it is imperative to consider these multifaceted factors.The predominantly rural lifestyle of the East African population underscores the importance of aligning modern lifestyles with the evolutionary past of Homo sapiens,where physical activity was integral to daily life.Further research is required to explain this phenomenon,with a focus on genetics.展开更多
Objectives The purpose was to directly assess in-competition thermoregulatory responses in recreational runners during a city marathon conducted in cool,ambient conditions using a two-pill ingestion strategy.Methods T...Objectives The purpose was to directly assess in-competition thermoregulatory responses in recreational runners during a city marathon conducted in cool,ambient conditions using a two-pill ingestion strategy.Methods Thirty-two recreational runners(age:38.7±10.2 years,mass:73.9±11.0 kg,height:177±8 cm)were invited to participate in this study.Core temperature was continuously assessed using telemetric ingestible pills.Each runner swallowed two pills:the first pill(Pill 1)11 h:47 min±1 h:01 min pre-race(before overnight sleep)and the second(Pill 2)2 h:35 min±0 h:54 min pre-race(on wakening).Results Pre-race core temperature for Pill 1 was significantly different from Pill 2,with values of 37.4±0.4℃and 37.1±0.6℃,respectively(p=0.006).The mean core temperature during the race was higher for Pill 1 compared to Pill 2(38.5±0.5℃and 37.8±1.0℃,respectively;p<0.001).Peak core temperature was higher for Pill 1 compared to Pill 2(39.1±0.5℃and 38.8±0.5℃,respectively;p=0.03).Post-race core temperature was higher for Pill 1 compared to Pill 2(38.8±0.7℃and 38.1±1.3℃,respectively;p=0.02).Conclusions The timing of pill ingestion significantly impacted core temperature and hence timing of pill ingestion should be standardised(5 h:30 min–7 h prior to measurement).Despite the relatively cool ambient conditions during the race,a significant number of runners achieved a high core body temperature(≥39℃),which was not accompanied by any signs of heat illness.展开更多
Defect engineering in photocatalytic materials has garnered significant interest due to the considerable impact of defects on light absorption,charge separation,and surface reaction dynamics.However,a limited understa...Defect engineering in photocatalytic materials has garnered significant interest due to the considerable impact of defects on light absorption,charge separation,and surface reaction dynamics.However,a limited understanding of how these defects influence photocatalytic properties remains a persistent challenge.This review comprehensively analyzes the vital role of defect engineering for enhancing the photocatalytic performance,highlighting its significant influence on material properties and efficiency.It systematically classifies defect types,including vacancy defects(oxygen and metal vacancies),doping defects(anion and cation),interstitial defects,surface defects(step edges,terraces,kinks,and disordered layers),antisite defects,and interfacial defects in the core–shell structures and heterostructure borders.The impact of complex defect groups and manifold defects on improved photocatalytic performance is also examined.The review emphasizes the principal benefits of defect engineering,including the enhancement of light adsorption,reduction of band gaps,improved charge separation and movements,and suppression of charge recombination.These enhancements lead to a boost in catalytic active sites,optimization of electronic structures,tailored band alignments,and the development of mid-gap states,leading to improved structural stability,photocorrosion resistance,and better reaction selectivity.Furthermore,the most recent improvements,such as oxygen vacancies,nitrogen and sulfur doping,surface defect engineering,and innovations in heterostructures,defect-rich metal–organic frameworks,and defective nanostructures,are examined comprehensively.This study offers essential insights into modern techniques and approaches in defect engineering,highlighting its significance in addressing challenges in photocatalytic materials and promoting the advancement of effective and adaptable platforms for renewable energy and environmental uses.展开更多
文摘The Deepwater Horizon Oil Spill in the USA’s Gulf of Mexico created a high degree of exposure of marine organisms to toxic polyaromatic hydrocarbons (PAHs) present in crude oil. To determine the ecological and physiological effects of crude oil on the Gulf of Mexico ecosystem, the Gulf of Mexico Research Initiative created several research consortia to address overreaching questions concerning the biological impacts of the ecology of the Gulf of Mexico that would otherwise be beyond the capabilities of an individual investigator or a small group. One of these consortia, highlighted in this article, is the RECOVER Consortium, which brings together physiologists, developmental biologists, toxicologists and other life scientists to focus on the multifaceted physiological effects of PAHs, especially as they pertain to cardiovascular and metabolic physiology of economically important fish species. Using the Recover Consortium’s interdisciplinary approach to revealing the biological impacts of the Deepwater Horizon Oil Spill as a case study, we make the argument for interdisciplinary teams that bring together scientists with different specialties as an efficient way—and perhaps the only way—to unravel highly complex biological effects of marine oil spills.
基金The Deanship of Scientific Research(DSR)at King Abdulaziz University(KAU),Jeddah,Saudi Arabia,has funded this project under Grant No.(KEP-PhD:72-130-1443).
文摘The Underwater Communication Link(UCL)is a crucial component of Underwater Wireless Optical Communication(UWOC)systems,requiring optimised design to mitigate the high power attenuation inherent in seawater.To ensure the reliability of an optimal UCL design,it is essential to account for the three primary scattering regimes:forward scattering(FSC),backward scattering(BSC),and isotropic scattering(ISC)in seawater channels.This study introduces a new photon-tracking model based on a discrete equation,facilitating Monte Carlo Simulation(MCS)to evaluate how different scattering regimes influence received photon distribution.Three distinct Scattering Regime Contribution Weight(SRCW)probability sets were employed,each representing different UCL operational configurations dominated by specific scattering regimes.The proposed modeling approach enables a comprehensive assessment of the temporal characteristics of received optical pulses,channel loss,and time spread-ultimately defining the optimal UCL design parameters.The key findings of this study include:(1)Enhancing the FSC regime dominance leads to a quasi-light waveguide effect over link spans and small Fields of View(FOV)<25°,significantly improving channel performance in Harbor seawater compared to Coastal seawater.(2)A well-designed UCL with a small FOV(<25°)can minimise channel loss and time spread,ensuring high capacity and efficient performance in both Coastal and Harbor seawaters.(3)When BSC and ISC contributions exceed FSC dominance,the received optical pulse undergoes significant temporal broadening,particularly for larger FOV angles(>25°)and extended link spans.(4)The developed novel MCS-based discrete equation provides a simple yet robust model for simulating photon propagation in both homogeneous and inhomogeneous underwater channels.These insights contribute to developing more efficient and reliable UCL designs with military standards by enhancing UWOC system performance over a longer linkspan for a given limited optical power across various underwater environments.
文摘Congenital hyperinsulinism(CHI) is a rare but complex heterogeneous disorder caused by unregulated secre-tion of insulin from the β-cells of the pancreas leading to severe hypoglycaemia and neuroglycopaenia. Swift diagnosis and institution of appropriate management is crucial to prevent or minimise adverse neurodevel-opmental outcome in children with CHI. Histologically there are two major subtypes of CHI, diffuse and focal disease and the management approach will significantly differ depending on the type of the lesion. Patients with medically unresponsive diffuse disease require a near total pancreatectomy, which then leads on to the de-velopment of iatrogenic diabetes mellitus and pancre-atic exocrine insufficiency. However patients with focaldisease only require a limited pancreatectomy to re-move only the focal lesion thus providing complete cure to the patient. Hence the preoperative differentiation of the histological subtypes of CHI becomes paramount in the management of CHI. Fluorine-18L-3, 4-hydroxy-phenylalanine positron emission tomography(18F-DOPA-PET) is now the gold standard for pre-operative differentiation of focal from diffuse disease and locali-sation of the focal lesion. The aim of this review article is to give a clinical overview of CHI, then review the role of dopamine in β-cell physiology and finally discuss the role of 18F-DOPA-PET imaging in the management of CHI.
文摘The interplay between glucose metabolism and that of the two other primary nutrient classes, amino acids and fatty acids is critical for regulated insulin secretion. Mitochondrial metabolism of glucose, amino acid and fatty acids generates metabolic coupling factors(such as ATP, NADPH, glutamate, long chain acyl-CoA and diacylglycerol) which trigger insulin secretion. The observation of protein induced hypoglycaemia in patients with mutations in GLUD1 gene, encoding the enzyme glutamate dehydrogenase(GDH) and HADH gene, encoding for the enzyme short-chain 3-hydroxyacyl-CoA dehydrogenase has provided new mechanistic insights into the regulation of insulin secretion by amino acid and fatty acid metabolism. Metabolic signals arising from amino acid and fatty acid metabolism converge on the enzyme GDH which integrates both signals from both pathways and controls insulin secretion. Hence GDH seems to play a pivotal role in regulating both amino acid and fatty acid metabolism.
文摘Objective: To examine the long-term effects of the Seattle Social Development Project intervention in promoting positive adult functioning and preventing men tal health problems, crime, and substance use (including tobacco, alcohol, and o ther drugs) at 21 years of age. Design: This nonrandomized controlled trial followed up participants to 21 years of age, 9 years after the intervention ended. We compared the following 3 intervention con ditions: a full 6-year intervention (grades 1 through 6); a late 2-year interv ention (grades 5 and 6 only); and a no-treatment control condition. Setting: Ei ghteen public elementary schools serving diverse neighborhoods, including high- crime neighborhoods, of Seattle, Wash. Participants: A sex-balanced, multiethni c sample of 605 participants across the 3 conditions who completed interviews at 21 years of age (94%of the original sample in these conditions). Interventions : Teacher training in classroom instruction and management, child social and emo tional skill development, and parent training. Main Outcome Measures: Self-repo rts of functioning in school and work, emotional and mental health, and crime an d substance use at 21 years of age and official court records. Results: Broad si gnificant effects on functioning in school and work and on emotional and mental health were found. Fewer significant effects on crime and substance use were fou nd at 21 years of age. Most outcomes had a consistent dose effect, with the stro ngest effects in subjects in the full-intervention group and effects in the lat e-intervention group between those in the full-intervention and control groups . Conclusions: A theoryguided preventive intervention that strengthened teaching and parenting practices and taught children interpersonal skills during the ele mentary grades had wide-ranging beneficial effects on functioning in early adul thood.
基金Supported by Science Fund from the Ministry of Science,Technology and Innovation Malaysia and Research Acculturation Grants of Universiti Teknologi MARA(UiTM)[RAGS/2012/Ui TM/ST04/1],Malaysia
文摘Objective: To investigate the antiviral property of a lead ligand, YK51 that was synthesized based on the flavanoid of a natural product toward dengue virus type-2(DENV2)replication.Methods: c RNA was isolated from HepG2 cells inoculated with 1 000 median tissue culture infective dose of DENV2 and treated with different doses of the ligand followed by RT-PCR to quantify the virus gene copies. Confocal microscopy of actin and tubulin redistribution was also performed.Results: The quantitative RT-PCR result showed reduction of the DENV2 gene copies as the ligand concentration was increased. The confocal microscopy result showed increase in the tubulin intensity(79.6%) of infected BHK21 cells treated with the ligand,compared with the non-treated cells(54.8%). The 1.5-fold increase in the intensity of tubulin suggested that the ligand inhibitory effect stabilized the cellular microtubule structure.Conclusions: The synthesized ligand YK51 reduced DENV2 viral load by inhibiting virus replication thus is highly potential to be developed as antiviral agent.
基金Ministry of Science,Technology and Innovation of Colombia through the“Fondo Francisco Joséde Caldas”National Financing Fund for Science,Technology and Innovation for the financing provided for the development of the project (Project 120885272102,Call 852 of 2019).
文摘Secondary lignocellulosic biomass has proved to be useful as an energy source through its oxidation by means of combustion processes.In accordance with the above,in this paper,we wanted to study the ash from urban pruning residues that are generated in cities in the Neotropics.Species such as Licania tomentosa,Azadirachta indica,Ficus benjamina,Terminalia catappa,Leucaena leucocephala,Prosopis juliflora and Pithecellobium dulce were selected because they have been previously studied and showed potential for thermal energy generation.These materials were calcined in an oxidizing atmosphere and characterized by X-ray diffraction and fluorescence,scanning electron microscopy with microchemistry,BET surface area,thermal gravimetric analysis,and differential scanning calorimetry.The pH and apparent density were also established.The results show high basicity materials(average pH 10),a behavior associated with the presence of chemical elements such as calcium,potassium,magnesium,chlorine,phosphorus,and sulfur.Structurally,these materials have a very significant amorphous fraction(between 49%and 74.5%),the dominant crystalline phases are calcite,arcanite,sylvite,and hydroxyapatite.These ashes have low surface area and do not exceed 13 m^(2)/g.Two characteristic morphological aspects were observed in these ashes:a morphology of rounded grains where silicon content is highlighted,and lamellar morphologies where the presence of chlorine is highlighted.Thermally,these ashes show four significant mass loss events(400℃,430℃,680℃,and 920℃),causing mass losses that vary between 25%and 40%.Through this study,it was possible to establish that,from a chemical point of view,these ashes are less dangerous in comparison with those of a mineral coal that was used as a reference.However,they require additional treatments for their disposal due to their high basicity.Because of their composition,these ashes have the potential to be used in the ceramic and cement industries,and in the manufacture of fertilizers.
基金the“Fondo Francisco Joséde Caldas”National Financing Fund for Science,Technology and Innovation for the financing provided for the development of the project(Project 120885272102,Call 852 of 2019).
文摘The material associated with tree pruning in a city in the Colombian neotropics was characterized in order to determine its energy potential.The species studied for their relevance in the territory were Prosopis juliflora,Licania tomentosa,Terminalia catappa,Azadirachta indica,Pithecellobium dulce,Ficus benjamina and Leucaena leucocephala.Moisture content,bulk density,hygroscopic response,elemental chemical analysis,proximal analysis,calorific value,ease of ignition and combustion,thermogravimetric and heat flow analysis,steam generation capacity,and qualitative analysis of gases(mass spectrometry)were determined.The results that were obtained show high initial moisture contents that vary between 37%and 67%and a variable density(when dry)between 0.21 and 0.41 g/cm3.Chemically,it was shown that all residues have lower carbon and sulfur content compared to a reference mineral coal.However,the residues of some species have higher nitrogen contents compared to the same coal.All biomasses are characterized by their high content of volatile fractions and by having a lower content of inorganic matter compared to carbon.The lower calorific values of these residues are between 14170 and 16928 kJ/kg,which are not negligible compared to other biomasses.This characteristic would be related to the high presence of hemicellulose in the residues.Flue gas monitoring revealed that there are different airflow needs in order to ensure complete combustion.Steam generation tests showed that the calorific value should not be the most relevant criterion to establish the potential use of the waste,since leucaena leucocephala,despite having the highest calorific value,was the material with the lowest performance in steam generation.
文摘Plasma X-ray sources for biological microscopy have been produced by focusing single shots from Nd:glass laser onto carbon rod targets at irradiances between 1 × 1013 W⋅cm−2 and 3 × 1013 W⋅cm−2 to expose test objects. The optimum parameters needed for obtaining high accurate information on the samples under test namely: the minimum energies and irradiances at a range of angles between the incoming laser beam and the normal to the resist, the depth of exposure of the photoresist as a function of incident laser energy (and irradiance) were concluded in this work.
文摘In this paper,the dust particle surface potential for argon-helium plasma is evaluated analytically and numerically in the context of negatively charged dust particles by employing a power-law(r,q)-distribution function.Recent studies have reported the argon-helium plasma and conducted a brief theoretical and experimental survey.To deepen our understanding further,this study aims to analyze the argon-helium plasma comprehensively using the same pattern but with the(r,q)-distribution function.For this purpose,the current balance equations are derived for electron,helium and argon ions,when these charge species attain the quasineutrality condition.We numerically examined the currents of plasma species for a broad range of effective distribution function parameters r and q.It is revealed that the surface potential of dust particles is significantly affected by the parameters r and q,helium ion-to-electron temperature ratio,argon ion-to-electron temperature ratio,and helium ion to argon ion number density ratio.By incorporating the multi-ion(argon-helium)species,the significance of low-temperature nonMaxwellian dusty(complex)plasma is briefly examined.
基金Maa-ja Vesitekniikan Tuki RyDepartment of Built Environment(OV),Aalto University。
文摘The world's urban population is soaring,with an increasing number of people exposed to urban natural hazards such as riverinefloods and storm surges.The global quantification of their extent is,however,still blurred.The ongoing surge in high-resolution data allows novel opportunities for quantification of hazards and exposure.Here,we provide a global spatial synthesis of urban populations'exposure to riverinefloods and storm surges in 1990 and 2015.Our results reveal that,owing to rapid economic development globally in a large proportion of exposed areas,most of the exposure has shifted from low-income to middle-income countries.Asia dominates as a continent.The total growth of human exposure continues,suggesting that disaster risk reduction policies and implementation call for enduring effort.
基金funded by Spanish‘Ministerio de Economía y Competitividad’‘Plan Nacional I+D+i 2008–2011(Project DEP DEP2011-29093)’and the“Fondo Europeo de Desarrollo Regional”(MICINN-FEDER)for supporting this project.
文摘Purpose To determine the association between lower-body strength and lower-body power capacities with sprint swimming performance in adolescent competitive swimmers.Methods A total of 44 front crawl swimmers(27 males and 17 females)performed anthropometric assessments,lower-body strength tests(half squat maximum isometric strength,dynamic half squat with 20,30 and 40%of the maximum isometric strength,and knee extension maximum isometric strength)and lower-body power tests(squat jump[SJ],countermovement jump[CMJ]and Abalakov jump).Further front crawl swimming best times in 50 and 100 m were recorded from official swimming competitions and front crawl technique was assessed by an experienced coach using a visual analogue scale.Results Swimming performance was correlated with lower-body power variables(SJ[r=−0.573 for 50 m and−0.642 for 100 m],CMJ[r=−0.497 for 50 m and−0.544 for 100 m],and Abalakov jump[r=−0.452 for 50 m and−0.415 for 100 m];p≤0.05)and lower-body strength(half squat maximum isometric strength[r=−0.430 for 50 m and−0.443 for 100 m];p≤0.05)in males but not in females.Further linear regression models showed that only lower-body power predicted both 50 m(Abalakov jump;r^(2)=0.58;change in r^(2)=0.18)and 100 m(SJ;r^(2)=0.66;change in r^(2)=0.15)performance in male swimmers.Conclusions This study emphasizes the greater association between lower-body power and sprint front crawl performance in adolescent males compared to females.Practical tests(i.e.,SJ and Abalakov jump)are shown to predict front crawl swimming performance,which may facilitate the performance control by coaches and trainers.
文摘Objectives The purpose of this study is to examine the effects of applying anodal tDCS(2 mA for 20 min)over the scalp from T3(anodal-tDCS)to Fp2(cathodal-tDCS)on the perceptual,physiological and performance responses during maximal incremental and constant-load exercise(CLE)in trained cyclists.Methods Eleven male cyclists performed maximal incremental exercise(MIE)on a cycle ergometer under either tDCS or sham,with power output,heart rate(HR),oxygen uptake(V̇O_(2)),ratings of perceived exertion(RPE)assessed throughout,and blood samples collected before and after MIE.On two separate occasions,nine subjects performed CLE at 62%of the peak power output followed by a 15 km time trial under either tDCS or sham(n=8 for the time trial).Results HR,V̇O_(2),RPE and blood samples were collected at regular intervals.There were no differences between tDCS and sham in any variable during the MIE.tDCS elicited a decreased HR(F_(4,8)=9.232;p=0.016;η_(p)^(2)=0.54),increased V̇O_(2)(F_(4,8)=8.920;p=0.015;η_(p)^(2)=0.50)and increased blood non-esterified fatty acids(F_(6,8)=11.754;p=0.009;η_(p)^(2)=0.60)and glycerol(F_(6,8)=6.603;p=0.037;η_(p)^(2)=0.49)concentrations during the CLE when compared to sham.tDCS also improved 15 km time trial performance by 3.6%(p=0.02;d=0.47)without affecting RPE,HR and blood lactate.Conclusions The application of tDCS over the temporal cortex in trained cyclists improved cycling performance during a self-paced time trial but did not enhance performance during maximal incremental exercise.These results are encouraging and merit further investigation of the ergogenic effects of tDCS in trained athletes.
文摘Introduction:Runners from East Africa including Kenya,Ethiopia and Uganda have dominated middle-and longdistance running events,for almost six decades.This narrative review examines and updates current understanding of the factors explaining the dominance of East Africans in distance running from a holistic perspective.Content:The dominance of East African distance runners has puzzled researchers,with various factors proposed to explain their unparalleled success.Four key elements emerge:1)biomechanical and physiological attributes,2)training characteristics,3)psychological motivations,and 4)African diet.Runners from East Africa often exhibit ectomorphic somatotypes,characterized by lean body compositions which lead them to an extraordinary biomechanical and metabolic effciency.Their sociocultural lifestyle,training regimens beginning at a young age with aerobic activities,seem crucial,as well as moderate volume,high-intensity workouts at altitudes ranging from 2,000 to 3,000 m.Psychological factors,including a strong motivation to succeed driven by aspirations for socioeconomic improvement and a rich tradition of running excellence,also contribute significantly.A multifactorial explanation considering these factors,without a clear genetic influence,is nowadays the strongest argument to explain the East African phenomenon.Summary and outlook:To unravel the mystery behind the supremacy of East African runners,it is imperative to consider these multifaceted factors.The predominantly rural lifestyle of the East African population underscores the importance of aligning modern lifestyles with the evolutionary past of Homo sapiens,where physical activity was integral to daily life.Further research is required to explain this phenomenon,with a focus on genetics.
文摘Objectives The purpose was to directly assess in-competition thermoregulatory responses in recreational runners during a city marathon conducted in cool,ambient conditions using a two-pill ingestion strategy.Methods Thirty-two recreational runners(age:38.7±10.2 years,mass:73.9±11.0 kg,height:177±8 cm)were invited to participate in this study.Core temperature was continuously assessed using telemetric ingestible pills.Each runner swallowed two pills:the first pill(Pill 1)11 h:47 min±1 h:01 min pre-race(before overnight sleep)and the second(Pill 2)2 h:35 min±0 h:54 min pre-race(on wakening).Results Pre-race core temperature for Pill 1 was significantly different from Pill 2,with values of 37.4±0.4℃and 37.1±0.6℃,respectively(p=0.006).The mean core temperature during the race was higher for Pill 1 compared to Pill 2(38.5±0.5℃and 37.8±1.0℃,respectively;p<0.001).Peak core temperature was higher for Pill 1 compared to Pill 2(39.1±0.5℃and 38.8±0.5℃,respectively;p=0.03).Post-race core temperature was higher for Pill 1 compared to Pill 2(38.8±0.7℃and 38.1±1.3℃,respectively;p=0.02).Conclusions The timing of pill ingestion significantly impacted core temperature and hence timing of pill ingestion should be standardised(5 h:30 min–7 h prior to measurement).Despite the relatively cool ambient conditions during the race,a significant number of runners achieved a high core body temperature(≥39℃),which was not accompanied by any signs of heat illness.
基金Deanship of Research and Graduate Studies at King Khalid University,Grant/Award Number:RGP2/363/46。
文摘Defect engineering in photocatalytic materials has garnered significant interest due to the considerable impact of defects on light absorption,charge separation,and surface reaction dynamics.However,a limited understanding of how these defects influence photocatalytic properties remains a persistent challenge.This review comprehensively analyzes the vital role of defect engineering for enhancing the photocatalytic performance,highlighting its significant influence on material properties and efficiency.It systematically classifies defect types,including vacancy defects(oxygen and metal vacancies),doping defects(anion and cation),interstitial defects,surface defects(step edges,terraces,kinks,and disordered layers),antisite defects,and interfacial defects in the core–shell structures and heterostructure borders.The impact of complex defect groups and manifold defects on improved photocatalytic performance is also examined.The review emphasizes the principal benefits of defect engineering,including the enhancement of light adsorption,reduction of band gaps,improved charge separation and movements,and suppression of charge recombination.These enhancements lead to a boost in catalytic active sites,optimization of electronic structures,tailored band alignments,and the development of mid-gap states,leading to improved structural stability,photocorrosion resistance,and better reaction selectivity.Furthermore,the most recent improvements,such as oxygen vacancies,nitrogen and sulfur doping,surface defect engineering,and innovations in heterostructures,defect-rich metal–organic frameworks,and defective nanostructures,are examined comprehensively.This study offers essential insights into modern techniques and approaches in defect engineering,highlighting its significance in addressing challenges in photocatalytic materials and promoting the advancement of effective and adaptable platforms for renewable energy and environmental uses.
