Lipid concentration and composition in xylem sap of woody angiosperms from a tropical savanna and a seasonal rainforest

Lipids may play an important role in preventing gas embolisms by coating nanobubbles in xylem sap.Few studies on xylem sap lipids have been reported for temperate plants,and it remain unclear whether sap lipids have adaptational significance in tropical plants.In this study,we quantify the lipid composition of xylem sap for angiosperm species from a tropical savanna(seven species)and a seasonal rainforest(five species)using mass spectrometry.We found that all twelve species studied contained lipids in their xylem sap,including galactolipids,phospholipids and triacylglycerol,with a total lipid concentration ranging from 0.09 to 0.26 nmol/L.There was no difference in lipid concentration or composition between plants from the two sites,and the lipid concentration was negatively related to species’open vessel volume.Furthermore,savanna species showed little variation in lipid composition between the dry and the rainy season.These results support the hypothesis that xylem sap lipids are derived from the cytoplasm of individual conduit cells,remain trapped inside individual conduits,and undergo few changes in composition over consecutive seasons.A xylem sap lipidomic data set,which includes 12 tropical tree species from this study and 11 temperate tree species from literature,revealed no phylogenetic signals in lipid composition for these species.This study fills a knowledge gap in the lipid content of xylem sap in tropical trees and provides additional support for their common distribution in xylem sap of woody angiosperms.It appears that xylem sap lipids have no adaptive significance.

Woody plant taxonomic,functional,and phylogenetic diversity decrease along elevational gradients in Andean tropical montane forests:Environmental filtering and arrival of temperate taxa

Mountains are paramount for exploring biodiversity patterns due to the mosaic of topographies and climates encompassed over short distances.Biodiversity research has traditionally focused on taxonomic diversity when investigating changes along elevational gradients,but other facets should be considered.For first time,we simultaneously assessed elevational trends in taxonomic,functional,and phylogenetic diversity of woody plants in Andean tropical montane forests and explored their underlying ecological and evolutionary causes.This investigation covered four transects(traversing ca.2200 m a.s.l.) encompassing 114 plots of 0.1 ha across a broad latitudinal range(ca.10°).Using Hill numbers to quantify abundance-based diversity among 37,869 individuals we observed a consistent decrease in taxonomic,functional,and phylogenetic diversity as elevation increased,although the decrease was less pronounced for higher Hill orders.The exception was a slight increase in phylogenetic diversity when dominant species were over-weighted.The decrease in taxonomic and functional diversity might be attributed to an environmental filtering process towards highlands,where the increasingly harsher conditions exclude species and functional strategies.Besides,the differences in steepness decrease between Hill orders suggest that rare species disproportionately contribute to functional diversity.For phylogenetic diversity the shifting elevational trend between Hill orders indicates a greater than previously considered influence in central Andean highlands of tropical lowlands originated species with strong niche conservatism relative to distantly related temperate lineages.This could be explained by a decreasing presence and abundance of temperate,extratropical taxa towards the central Andes relative to northern or southern Andes,where they are more prevalent.

Environmental Conditions Conducive to the Formation of Multiple Tropical Cyclones over the Western North Pacific

There is limited understanding regarding the formation of multiple tropical cyclones(MTCs).This study explores the environmental conditions conducive to MTC formation by objectively determining the atmospheric circulation patterns favorable for MTC formation over the western North Pacific.Based on 199 MTC events occurring from June to October 1980–2020,four distinct circulation patterns are identified:the monsoon trough(MT)pattern,accounting for 40.3%of occurrences,the confluence zone(CON)pattern at 26.2%,the easterly wave(EW)pattern at 17.8%,and the monsoon gyre(MG)pattern at 15.7%.The MT pattern mainly arises from the interaction between the subtropical high and the monsoon trough,with MTCs forming along the monsoon trough and its flanks.The CON pattern is affected by the subtropical high,the South Asian high,and the monsoon trough,with MTCs emerging at the confluence zone where the prevailing southwesterly and southeasterly flows converge.The EW pattern is dominated by easterly flows,with MTCs developing along the easterly wave train.MTCs in the MG pattern arise within a monsoon vortex characterized by strong southwesterly flows.A quantitative analysis further indicates that MTC formation in the MT pattern is primarily governed by mid-level vertical velocity and low-level vorticity,while mid-level humidity and vertical velocity are significantly important in the other patterns.The meridional shear and convergence of zonal winds are essential in converting barotropic energy from the basic flows to disturbance kinetic energy,acting as the primary source for eddy kinetic energy growth.

Track-Pattern-Based Characteristics of Extratropical Transitioning Tropical Cyclones in the Western North Pacific

Based on the Regional Specialized Meteorological Center(RSMC)Tokyo-Typhoon Center best-track data and the NCEP-NCAR reanalysis dataset,extratropical transitioning(ET)tropical cyclones(ETCs)over the western North Pacific(WNP)during 1951–2021 are classified into six clusters using the fuzzy c-means clustering method(FCM)according to their track patterns.The characteristics of the six hard-clustered ETCs with the highest membership coefficient are shown.Most tropical cyclones(TCs)that were assigned to clusters C2,C5,and C6 made landfall over eastern Asian countries,which severely threatened these regions.Among landfalling TCs,93.2%completed their ET after landfall,whereas 39.8%of ETCs completed their transition within one day.The frequency of ETCs over the WNP has decreased in the past four decades,wherein cluster C5 demonstrated a significant decrease on both interannual and interdecadal timescales with the expansion and intensification of the western Pacific subtropical high(WPSH).This large-scale circulation pattern is favorable for C2 and causes it to become the dominant track pattern,owning to it containing the largest number of intensifying ETCs among the six clusters,a number that has increased insignificantly over the past four decades.The surface roughness variation and three-dimensional background circulation led to C5 containing the maximum number of landfalling TCs and a minimum number of intensifying ETCs.Our results will facilitate a better understanding of the spatiotemporal distributions of ET events and associated environment background fields,which will benefit the effective monitoring of these events over the WNP.

Change in the Number of Tropical Cyclone Landfall and Approach over Mozambique from 1980 to 2020

In this study, the variability of tropical cyclone (TC) landfall and approach over Mozambique as well as the environmental factors influencing were investigated. The frequencies of tropical cyclone landfall and approach as well as environmental factors were compared between the two periods (1980 to 1999 and 2000 to 2020). This study found that, according to International Best Track Archive for Climate Stewardship (IBTrACS) tropical cyclone data, the number of tropical cyclones making landfall over Mozambique increased by about 66% in the second period (2000-2020), compared to 34% in the first period (1980-1999). While the number of tropical cyclone approaches reduced from 59% in the first period to 41% in the second period. An assessment of the environmental conditions showed that warmer sea surface temperature (SST) and low vertical wind shear (VWS) were favorable to more TC genesis and, consequently, an increase in landfalls and a reduction in TC confined to the approach.

A Physics-informed Deep-learning Intensity Prediction Scheme for Tropical Cyclones over the Western North Pacific

Accurate prediction of tropical cyclone(TC)intensity is challenging due to the complex physical processes involved.Here,we introduce a new TC intensity prediction scheme for the western North Pacific(WNP)based on a time-dependent theory of TC intensification,termed the energetically based dynamical system(EBDS)model,together with the use of a long short-term memory(LSTM)neural network.In time-dependent theory,TC intensity change is controlled by both the internal dynamics of the TC system and various environmental factors,expressed as environmental dynamical efficiency.The LSTM neural network is used to predict the environmental dynamical efficiency in the EBDS model trained using besttrack TC data and global reanalysis data during 1982–2017.The transfer learning and ensemble methods are used to retrain the scheme using the environmental factors predicted by the Global Forecast System(GFS)of the National Centers for Environmental Prediction during 2017–21.The predicted environmental dynamical efficiency is finally iterated into the EBDS equations to predict TC intensity.The new scheme is evaluated for TC intensity prediction using both reanalysis data and the GFS prediction data.The intensity prediction by the new scheme shows better skill than the official prediction from the China Meteorological Administration(CMA)and those by other state-of-art statistical and dynamical forecast systems,except for the 72-h forecast.Particularly at the longer lead times of 96 h and 120 h,the new scheme has smaller forecast errors,with a more than 30%improvement over the official forecasts.

Corrigendum to“Migration pattern of a population of Barn Swallows(Hirundo rustica)breeding in East Asian tropical region”[Avian Res.15(2024)100192]

The authors regret that the caption of Fig.4 should be replaced as below.

Influence of Human Activity Intensity on Habitat Quality in Hainan Tropical Rainforest National Park,China

Due to long-term human activity interference,the Hainan Tropical Rainforest National Park(HTRNP)of China has experienced ecological problems such as habitat fragmentation and biodiversity loss,and with the expanding scope and intensity of human activity impact,the regional ecological security is facing serious challenges.A scientific assessment of the interrelationship between human activity intensity and habitat quality in the HTRNP is a prerequisite for achieving effective management of ecological disturbances caused by human activities and can also provide scientific strategies for the sustainable development of the region.Based on the land use change data in 2000,2010,and 2020,the spatial and temporal variations and the relationship between habitat quality(HQ)and human activity intensity(HAI)in the HTRNP were explored using the integrated valuation of ecosystem services and trade-offs(InVEST)model.System dynamics and land use simulation models were also combined to conduct multi-scenario simulations of their relationships.The results showed that during 2000–2020,the habitat quality of the HTRNP improved,the intensity of human activities decreased each year,and there was a negative correlation between the two.Second,the system dynamic model could be well coupled with the land use simulation model by combining socio-economic and natural factors.The simulation scenarios of the coupling model showed that the harmonious development(HD)scenario is effective in curbing the increasing trend of human activity intensity and decreasing trend of habitat quality,with a weaker trade-off between the two compared with the baseline development(BD)and investment priority oriented(IPO)scenarios.To maintain the authenticity and integrity of the HTRNP,effective measures such as ecological corridor construction,ecological restoration,and the implementation of ecological compensation policies need to be strengthened.

The Contribution of United States Aircraft Reconnaissance Data to the China Meteorological Administration Tropical Cyclone Intensity Data:An Evaluation of Homogeneity

This paper investigates the homogeneity of United States aircraft reconnaissance data and the impact of these data on the homogeneity of the tropical cyclone(TC)best track data for the seasons 1949-1987 generated by the China Meteorological Administration(CMA).The evaluation of the reconnaissance data shows that the minimum central sea level pressure(MCP)data are relatively homogeneous,whereas the maximum sustained wind(MSW)data show both overestimations and spurious abrupt changes.Statistical comparisons suggest that both the reconnaissance MCP and MSW were well incorporated into the CMA TC best track dataset.Although no spurious abrupt changes were evident in the reconnaissance-related best track MCP data,two spurious changepoints were identified in the remainder of the best-track MCP data.Furthermore,the influence of the reconnaissance MSWs seems to extend to the best track MSWs unrelated to reconnaissance,which might reflect the optimistic confidence in making higher estimates due to the overestimated extreme wind“observations”.In addition,the overestimation of either the reconnaissance MSWs or the best track MSWs was greater during the early decades compared to later decades,which reflects the important influence of reconnaissance data on the CMA TC best track dataset.The wind-pressure relationship(WPR)used in the CMA TC best track dataset is also evaluated and is found to overestimate the MSW,which may lead to inhomogeneity within the dataset between the aircraft reconnaissance era and the satellite era.

Characteristics and Preliminary Causes of Tropical Cyclone Remote Precipitation over China

In this study,the characteristics and preliminary causes of tropical cyclone remote precipitation(TRP)over China during the period from 1979 to 2020 are investigated.Results indicated that approximately 72.42%of tropical cyclones(TCs)in the Western Pacific produce TRP over China.The peak months for TRP are July and August.The four key regions of TRP are the adjacent areas between the Sichuan and Shaanxi Provinces,the northern coast of the Bohai Sea,the coast of the Yellow Sea,and the southern coast area.The typical distance between the station with TRP and the TC center ranges from 1500 to 2500 km.Most of these stations are situated north to 60°west of north of the TC.The south–west water vapor transportation on the west side of the TC is crucial to TRP.TRP has a decreasing trend because of the decrease in the number of TCs that generate TRP.From the perspective of large-scale environmental conditions,a decrease in the integrated horizontal water vapor transport in China' Mainland,the weakening of upward motion at approximately 25°–35°N,which is inconducive to convection,and an increase in low-level vertical wind shear,which is unfavorable for the development of TC in areas with high frequencies of TRP-related TCs,are the factors that result in the decreasing trend of TRP.

On the Optimal Initial Inner-Core Size for Tropical Cyclone Intensification: An Idealized Numerical Study

Recent observational and numerical studies have revealed the dependence of the intensification rate on the inner-core size of tropical cyclones(TCs). In this study, with the initial inner-core size(i.e., the radius of maximum wind—RMW)varied from 20–180 km in idealized simulations using two different numerical models, we found a nonmonotonic dependence of the lifetime maximum intensification rate(LMIR) on the inner-core size. Namely, there is an optimal innercore size for the LMIR of a TC. Tangential wind budget analysis shows that, compared to large TCs, small TCs have large inward flux of absolute vorticity due to large absolute vorticity inside the RMW. However, small TCs also suffer from strong lateral diffusion across the eyewall, which partly offsets the positive contribution from large inward flux of absolute vorticity. These two competing processes ultimately lead to the TC with an intermediate initial inner-core size having the largest LMIR. Results from sensitivity experiments show that the optimal size varies in the range of 40–120 km and increases with higher sea surface temperature, lower latitude, larger horizontal mixing length, and weaker initial TC intensity. The 40–120 km RMW corresponds to the inner-core size most commonly found for intensifying TCs in observations, suggesting the natural selection of initial TC size for intensification. This study highlights the importance of accurate representation of TC inner-core size to TC intensity forecasts by numerical weather prediction models.

Westerlies Affecting the Seasonal Variation of Water Vapor Transport over the Tibetan Plateau Induced by Tropical Cyclones in the Bay of Bengal

This study investigates the activity of tropical cyclones(TCs)in the Bay of Bengal(BOB)from 1979 to 2018 to discover the mechanism affecting the contribution rate to the meridional moisture budget anomaly(MMBA)over the southern boundary of the Tibetan Plateau(SBTP).May and October–December are the bimodal phases of BOB TC frequency,which decreases month by month from October to December and is relatively low in May.However,the contribution rate to the MMBA is the highest in May.The seasonal variation in the meridional position of the westerlies is the key factor affecting the contribution rate.The relatively southern(northern)position of the westerlies in November and December(May)results in a lower(higher)contribution rate to the MMBA.This mechanism is confirmed by the momentum equation.When water vapor enters the westerlies near the trough line,the resultant meridional acceleration is directed north.It follows that the farther north the trough is,and the farther north the water vapor can be transported.When water vapor enters the westerlies from the area near the ridge line,for Type-T(Type-R)TCs,water vapor enters the westerlies downstream of the trough(ridge).Consequently,the direction of the resultant meridional acceleration is directed south and the resultant zonal acceleration is directed east(west),which is not conducive to the northward transport of water vapor.This is especially the case if the trough or ridge is relatively south,as the water vapor may not cross the SBTP.

Migration pattern of a population of Barn Swallows(Hirundo rustica)breeding in East Asian tropical region

Birds exhibit a high degree of migratory diversity,which is influenced by various ecological factors and life history strategies.Conducting studies on tropical bird migration,of which research is scarce,and comparing it with temperate birds can enhance our understanding of bird migration behaviour and its underlying mecha-nisms.In this study,we explored the migration behaviour of a breeding population of the Barn Swallow(Hirundo rustica)in Zhanjiang,southern China,a region located in the northern tropics,using light-level geolocators.From 2021 to 2023,we deployed geolocators on 92 breeding swallows and retrieved geolocators successfully from 23 individuals.These swallows all exhibited migratory behaviour,and wintering on various islands in Southeast Asia.They displayed sex differences in their wintering locations.All males concentrated in Borneo,while females primarily chose Borneo but also dispersed to the Philippines,South China Sea,and Vietnam for wintering.The studied swallow population adopted a seasonal migration pattern of“indirect in autumn,direct in spring”,bypassing the ecological barrier of the South China Sea in autumn and tending to directly cross it in spring migration.Moreover,the distance and duration of autumn migration was significantly longer than those of the spring migration.Compared to temperate Barn Swallows,the Barn Swallow population breeding in Zhanjiang adopts a pattern of“intra-tropical migration”and initiates autumn migration earlier.The formation of their migration pattern may be limited by ecological and physiological factors.

Seedling dynamics differ between canopy species and understory species in a tropical seasonal rainforest,SW China

We used 11 years of census data from 450 seedling quadrats established in a 20-ha forest dynamics plot to study seedling dynamics in tree species of a tropical seasonal rainforest in Xishuangbanna,southwestern China.We found that overall seedling recruitment rate and relative growth rate were higher in the rainy season than in the dry season.Both the recruitment rate of seedlings from canopy tree species(two species)and the relative growth rate of seedlings from understory species(nine species)were higher in the rainy season than in the dry season.However,in the rainy season,the recruitment rate of seedlings was higher for canopy tree species than for understory tree species.In addition,relative growth rate of seedlings was higher in the canopy species than in understory seedlings in the dry season.We also observed that,in both rainy and dry seasons,mortality rate of seedlings was higher for canopy species than for understory species.Overall,canopy tree species appear to have evolved a flexible strategy to adapt to the seasonal changes of a monsoon climate.In contrast,understory tree species seem to have adopted a conservative strategy.Specifically,these species mainly release seedlings in the rainy season and maintain relatively stable populations with a lower mortality rate and recruitment rate in both dry and rainy seasons.Our study suggests that canopy and understory seedling populations growing in forest understory may respond to future climate change scenarios with distinct regeneration strategies.

Alignment of Track Oscillations during Tropical Cyclone Rapid Intensification

Recent studies on tropical cyclone(TC)intensity change indicate that the development of a vertically aligned TC circulation is a key feature of its rapid intensification(RI),however,understanding how vortex alignment occurs remains a challenging topic in TC intensity change research.Based on the simulation outputs of North Atlantic Hurricane Wilma(2005)and western North Pacific Typhoon Rammasun(2014),vortex track oscillations at different vertical levels and their associated role in vortex alignment are examined to improve our understanding of the vortex alignment during RI of TCs with initial hurricane intensity.It is found that vortex tracks at different vertical levels oscillate consistently in speed and direction during the RI of the two simulated TCs.While the consistent track oscillation reduces the oscillation tilt during RI,the reduction of vortex tilt results mainly from the mean track before RI.It is also found that the vortex tilt is primarily due to the mean vortex track before and after RI.The track oscillations are closely associated with wavenumber-1 vortex Rossby waves that are dominant wavenumber-1 circulations in the TC inner-core region.This study suggests that the dynamics of the wavenumber-1 vortex Rossby waves play an important role in the regulation of the physical processes associated with the track oscillation and vertical alignment of TCs.

Investigation of Maxima Assumptions in Modelling Tropical Cyclone- Induced Hazards in the South China Sea

The present study aims to examine the suitability of two commonly used assumptions that simplify modelling metoceanconditions for designing offshore wind turbines in the South China Sea (SCS). The first assumption assumes thatjoint N-year extreme wind and wave events can be independently estimated and subsequently combined. The secondone assumes peak wind and waves can be modelled as occurring simultaneously during a tropical cyclone (TC) event.To better understand the potential TC activity, a set of 10000 years synthetic TC events are generated. The wind fieldmodel and the Mike 21 spectral wave model are employed to model the TC-induced hazards. Subsequently, theeffect of the assumptions is evaluated by analyzing the peak structural response of both monopile and semisubmersibleoffshore wind turbines during TC events. The results demonstrate that the examined assumptions are generally accurate.By assessing the implications of these assumptions, valuable insights are obtained, which can inform andimprove the modelling of TC-induced hazards in the SCS region.

Information for Authors Asian Pacific Journal of Tropical Biomedcine

GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.

Subtropical forest macro-decomposers rapidly transfer litter carbon and nitrogen into soil mineral-associated organic matter

Background:Forest soils in tropical and subtropical areas store a significant amount of carbon.Recent framework to assess soil organic matter(SOM)dynamics under evolving global conditions suggest that dividing bulk SOM into particulate and mineral-associated organic matter(POM vs.MAOM)is a promising method for identifying how SOM contributes to reducing global warming.Soil macrofauna,earthworms,and millipedes have been found to play an important role in facilitating SOM processes.However,how these two co-existing macrofaunae impac the litter decomposition process and directly impact the formation of POM and MAOM remains unclear.Methods:Here,we set up a microcosm experiment,which consisted of 20 microcosms with four treatments earthworm and litter addition(E),millipedes and litter addition(M),earthworm,millipedes,and litter addition(E+M),and control(only litter addition)in five replicates.The soil and litter were sterilized prior to beginning the incubation experiment to remove any existing microbes.After incubating the samples for 42 days,the litte properties(mass,C,and N contents),soil physicochemical properties,as well as the C and N contents,and POM and MAOM^(13)C abundance in the 0–5 and 5–10 cm soil layers were measured.Finally,the relative influences o soil physicochemical and microbial properties on the distribution of C and N in the soil fractions were analyzed Results:The litter mass,C,and N associated with all four treatments significantly decreased after incubation especially under treatment E+M(litter mass:-58.8%,litter C:-57.0%,litter N:-75.1%,respectively),while earthworm biomass significantly decreased under treatment E.Earthworm or millipede addition alone showed no significant effects on the organic carbon(OC)and total nitrogen(TN)content in the POM fraction,but join addition of both significantly increased OC and TN regardless of soil depth.Importantly,all three macrofauna treatments increased the OC and TN content and decreased the^(13)C abundance in the MAOM fraction.More than65%of the total variations in the distribution of OC and TN throughout the two fractions can be explained by a combination of soil physicochemical and microbial properties.Changes in the OC distribution in the 0–5 cm soi layer are likely due to a decrease in soil pH and an increase in arbuscular mycorrhizal fungi(AMF),while those in the 5–10 cm layer are probably caused by increases in soil exchangeable Ca and Mg,in addition to fungi and gram-negative(GN)bacteria.The observed TN distribution changes in the 0–5 cm soil likely resulted from a decrease in soil pH and increases in AMF,GN,and gram-negative(GP)bacteria,while TN distribution changes in the 5–10 cm soil could be explained by increases in exchangeable Mg and GN bacteria.Conclusions:The results indicate that the coexistence of earthworms and millipedes can accelerate the litte decomposition process and store more C in the MAOM fractions.This novel finding helps to unlock the processe by which complex SOM systems serve as C sinks in tropical forests and addresses the importance of soil mac rofauna in maintaining C-neutral atmospheric conditions under global climate change.

Roles of Upper-Level Descending Inflow in Moat Development in Simulated Tropical Cyclones with Secondary Eyewall Formation

This study investigated the effects of upper-level descending inflow(ULDI)associated with inner-eyewall convection on the formation of the moat in tropical cyclones(TCs)with secondary eyewall formation(SEF).In our numerical experiments,a clear moat with SEF occurred in TCs with a significant ULDI,while no SEF occurred in TCs without a significant ULDI.The eyewall convection developed more vigorously in the control run.A ULDI occurred outside the inner-eyewall convection,where it was symmetrically unstable.The ULDI was initially triggered by the diabatic warming released by the inner eyewall and later enhanced by the cooling below the anvil cloud.The ULDI penetrated the outer edge of the inner eyewall with relatively dry air and prevented excessive solid-phase hydrometeors from being advected further outward.It produced extensive sublimation cooling of falling hydrometeors between the eyewall and the outer convection.The sublimation cooling resulted in negative buoyancy and further induced strong subsidence between the eyewall and the outer convection.As a result,a clear moat was generated.Development of the moat in the ongoing SEF prevented the outer rainband from moving farther inward,helping the outer rainband to symmetrize into an outer eyewall.In the sensitivity experiment,no significant ULDI formed since the eyewall convection was weaker,and the eyewall anvil developed relatively lower,meaning the formation of a moat and thus an outer eyewall was less likely.This study suggests that a better-represented simulation of inner-eyewall convective structures and distribution of the solid-phase hydrometeors is important to the prediction of SEF.

Information for Authors Asian Pacific Journal of Tropical Biomedcine

GENERAL Asian Pacific Journal of Tropical Biomedicine is sponsored by Hainan Medical University Journal Publisher,and aims to set up an acdemic communicating platform for scientists all over the world on tropical biomedicine and related sciences.The Journal invites concise reports of original research in all areas of tropical biomedicine and related fields,both experimental and clinical,including modern,traditional and epidemiological studies,from any part of the world.Review articles based primarily on authors'own research on internationally important topics will be accepted.Short communications and letters to the editor are also welcome.