Dynamics of Rodent and Rodent-borne Disease during Construction of the Three Gorges Reservoir from 1997 to 2012

Objective To investigate the impact of impoundment and active public health interventions on rodent populations and rodent-borne diseases in the Three Gorges reservoir region from 1997 to 2012. Methods Surveillance data from 1997 to 2012 were extracted from the Public Health Surveillance System of The Three Gorges established in 1997. Temporal changes in the incidences of hemorrhagic fever with renal syndrome （HFRS） and leptospirosis, rodent density, pathogen-carrying rates, and their correlations were analyzed. Results The average indoor and outdoor rodent densities decreased overall from 1997 to 2012. The average densities decreased by 47.72% （from 4.38% to 2.29%） and 39.68% （from 4.41% to 2.66%）, respectively, after impoundment （2003-2012） compared with before impoundment （1997-2002）. The average annual incidence rates of HFRS and leptospirosis were 0.29/100,000 and 0.52/100,000, respectively, and decreased by 85.74% （from 0.68/100,000 to 0.10/100,000） and 95.73% （from 1.47/100,000 to 0.06S/100,000）, respectively, after impoundment compared with before impoundment. Incidences of HFRS and leptospirosis appear to be positively correlated with rodent density in the reservoir area. Conclusion This study demonstrated that rodent density and incidences of rodent-borne diseases decreased and were maintained at low levels during construction of the Three Gorges dam. Measures that reduce rodent population densities could be effective in controlling rodent-borne diseases during large-scale hydraulic engineering construction.

The result of bagged Pyrinuron baits for controlrodent pest of forests

Bagged and dispersed Pyrinuron (a self-formulated rodenticide) were tested for control of Clethrionomus rutilus and Clethrionomus rufocanus in larch plantation, Pingshan area, Heilongjiang Province from Oct. 1998 to Apr. 1999. The results showed that the bagged Pyrinuron has good result for control of the two rodent pests. The density of rodents was reduced by 90.5% after application of bagged Pyrinuron. This application method has characteristics of long residual period, bait not going mould and saving labour force.

Rodent Damage and Control Methods in Hami Grassland of Xinjiang

Since 2002,Hami City,Xinjiang Province,has implemented"construction project of rodent-free demonstration area".Artificial eagle frames are installed on the grassland to control rodent damage,receiving remarkable control effect.The rodent density in the treatment area is below the threshold of hazard.Moreover,the implementation of the project increases the grassland biomass and improves the vegetation coverage,receiving good economic,ecological and social benefits.

Rodent biology and management: Current status, opinion and challenges in China

China experiences serious agricultural damages from rodents, and, correspondingly, researchers in China are actively studying rodent biology and management. Following the popularization of ecologically-based rodent pest management and extension of the basic state policy of Ecological Civilization Construction in China, recent efforts in rodent control technologies are mainly focused on eliminating side effects of rodenticides and developing environmentally friendly techniques. Considering ecological functions of rodents to test their interaction with the environment is a promising design for understanding rodent populations in local ecosystems and for developing ecologically-based rodent management. Using ecological phenotypes and applying advanced techniques of molecular biology, genetics, and epigenetics might be useful for illustrating the deep regulatory mechanisms of fluctuations in rodent populations. However, facing the dual characteristics of rodents as pests and their roles as keystone species in many ecosystems, it is still a challenge to establish reasonable local thresholds to balance rodent management with the negative effects of rodent control on the environment in the future.

Phylogenomic relationships and molecular convergences to subterranean life in rodent family Spalacidae

All extant species in the rodent family Spalacidae are subterranean and have evolved various traits for underground life.However,the phylogenomic relationships among its three subfamilies(Myospalacinae,Spalacinae,and Rhizomyinae)and the molecular basis underlying their adaptations to underground life remain poorly understood.Here,we inferred the phylogenomic relationships among these subfamilies based on de novo sequencing the genome of the hoary bamboo rat(Rhizomys pruinosus).Analyses showed that 50%of the identified 11028 one-to-one orthologous protein-coding genes and the concatenated sequences of these orthologous genes strongly supported a sister relationship between Myospalacinae and Rhizomyinae.

Technical comments on rodent spinal cord injuries models

Spinal cord injuries （SCI） in rodents have been created by laceration, contusion, compression, or intramedullary injection of toxic agents. The choice of an appropriate SCI model should be made for each study based on the experimental design, with care taken to avoid unintended complications such as hemorrhage. Technical comments will be made in this communication describing the 1） importance of vertebral stabi- lization, 2） injury preparation, and 3） landmarks to improve the preci- sion and reproducibility of the SCI.

Analgesic Appraisal of Bidens pilosa (Asteraceae) Leaf Extracts Used in Management of Oral Lesion Pain in HIV/AIDS Patients in Rodents

Oral lesions, diarrhoea, Pneumocystis carinii pneumonia, tuberculosis and urinary tract infections are some of the opportunistic infections (OIs) which arise when the CD4 cells of the HIV/AIDS patient fall below 200 cells/mm3. HIV/AIDS infection complications include tissue damage from oral lesions accompanied with pains. Pain is a disagreeable sensory and sensitive experience associated with actual or potential tissue damage. This condition requires immediate treatment with analgesics and antibiotics. However, the inability of rural dwellers to afford readily available drugs is a consequence for using herbs like Bidens pilosa whose local usefulness in the management of oral lesions of HIV/AIDS has not been proven scientifically. Therefore, the objective of this study was to provide the scientific basis in rats for the traditional healers’ use of Bidens pilosa leaves’ extracts in managing pain associated with oral lesions of HIV/AIDS patients in South Western Uganda. Assessment of the analgesic effects of Bidens pilosa was conducted using acetic acid in mice, formalin-induced pain and tail flick methods in rats. Both aqueous and ethanolic extracts of the leaves of Bidens pilosa produced statistically significant dose dependent inhibition of acetic acid induced pain, non dose dependent pain reduction in formalin induced pain, (p < 0.05;student t-test) and non dose dependent tail withdrawal pattern (p < 0.05, Multivariate ANOVA test). Hence, we conclude that extracts of Bidens pilosa have an analgesic basis for their local use in treatment of oral lesions associated pain in HIV/AIDS patients in South-Western Uganda.

Novel rodent models of penetrating traumatic brain injury

A penetrating traumatic brain injury（pTBI）occurs when an object impacts the head with sufficient energy to penetrate skin,cranial bone and meninges to inflict injury directly to the brain parenchyma.This type of injury is particularly common in areas plagued by armed conflicts or gun-related violence.

Establishment and assessment of rodent models of medication-related osteonecrosis of the jaw(MRONJ)

Medication-related osteonecrosis of the jaw(MRONJ)is primarily associated with administering antiresorptive or antiangiogenic drugs.Despite significant research on MRONJ,its pathogenesis and effective treatments are still not fully understood.Animal models can be used to simulate the pathophysiological features of MRONJ,serving as standardized in vivo experimental platforms to explore the pathogenesis and therapies of MRONJ.Rodent models exhibit excellent effectiveness and high reproducibility in mimicking human MRONJ,but classical methods cannot achieve a complete replica of the pathogenesis of MRONJ.Modified rodent models have been reported with improvements for better mimicking of MRONJ onset in clinic.This review summarizes representative classical and modified rodent models of MRONJ created through various combinations of systemic drug induction and local stimulation and discusses their effectiveness and efficiency.Currently,there is a lack of a unified assessment system for MRONJ models,which hinders a standard definition of MRONJ-like lesions in rodents.Therefore,this review comprehensively summarizes assessment systems based on published peer-review articles,including new approaches in gross observation,histological assessments,radiographic assessments,and serological assessments.This review can serve as a reference for model establishment and evaluation in future preclinical studies on MRONJ.

Mitochondrial D-loop diversity of grasscutter (<i>Thryonomys swinderianus</i>Rodentia: Hystricomorpha) in Ghana

Attempts are being made to domesticate the grasscutter (Thryonomys swinderianus) for commercial production in Sub-Saharan Africa to cater for the protein needs of the people and to satisfy the craving for bushmeat, thereby reducing habitat destruction through hunting. The objective of this study was to determine the genetic diversity of grasscutter populations in Ghana. DNA was extracted from roots of hair samples collected from 84 grasscutters from three agro-ecological zones in Ghana, namely Guinea Savanna (n = 17), Forest (n = 22), and Coastal Savanna (n = 45). Mitochondrial D-loop was sequenced and the diversity was determined across the zones. Out of 26 haplotypes found, 15 were obtained from Guinea Savanna, 7 from Forest and 13 from Coastal Savanna. Haplotype diversities were 0.978, 0.853 and 0.875 respectively for Guinea Savanna, Forest and Coastal Savanna zones. Analysis of molecular variance (AMOVA) revealed significant differentiation between Forest and Savanna populations (FST = 0.14, p 0.05). Network analysis indicated two clusters, one of which consisted of only Savanna haplotypes. Population neutrality tests showed that Forest and Coastal Savanna populations had been stable while the Guinea Savanna zone population had undergone an expansion (Fu’s FS = ‐7.132,

Study on the Classification and Diversity of Zonal Rodent Community in Semi-Desert and Desert Areas of China

Many studies focus on rodent community pattern and changing at present in the world, but most of them are conducted in small plots. Few studies investigated the rodent community classification and diversity in semi-desert and desert areas at regional scale, although some researchers started to study the change of animal community patterns on a large scale. We investigated rodent communities in desert, non-irrigated farming land and desert steppe of Inner Mongolia, covering an area of 380,000 km2 from May to August in 1988-1993 and in 1998-2003, respectively, in order to reveal the changing characteristics of zonal rodent communities. The community classification and diversity of rodents were analyzed in research areas. The results suggested that the communities could be classified in 9 zonal types. Spermophilus dauricus, Cricetulus longicaudatus and Eutamias sibiricus were dominant species in Community I;Phodopus roborovskii, Cricetulus barabansis and Cricetulus longicaudatus were dominant in Community II;Meriones unguiculatus, Phodopus roborovskii and Cricetulus longicaudatus were dominant in Community III;Allactaga sibirica, Allactaga bullata and Spermophilus dauricus were dominant in Community IV;Allactaga bullata, Dipus sagitta and Meriones unguiculatus were dominant in Community V;Meriones meridianus, Spermophilus dauricus and Allactaga bullata were dominant in Community VI;Allactaga sibirica, Allactaga bullata and Dipus sagitta were dominant in Community VII;Phodopus roborovskii, Dipus sagitta and Allactaga sibirica were dominant in Community VIII;Meriones meridianus, Dipus sagitta and Allactaga sibirica were dominant in Community IX. The community diversity and evenness analysis showed that the edge effect of community, the effect of disturbance and habitat fragmentation and scale effect were significantly correlated with community diversity in the semi-desert and desert regions. The ordinal results of 9 zonal rodent communities were in accordance with the results analyzed with similar community indices, showing the habitat change in the characteristics of the above-mentioned groups.

Rodent-mediated plant community competition:what happens to the seeds after entering the adjacent stands?

Background:Seed dispersal by scatter-hoarding animals can affect the developmental dynamics of plant communities.However,how animals might participate in plant inter-community competition has rarely been investigated.Forest community junction is an area where the competition between plant communities is most prominent and animal activity is more frequent.At present,little is known about how scatter-hoarding animals might assist competitions by adjacent plant communities.Thus,for 3 years(2015–2017),we tracked the fate of 2880 tagged seeds(Quercus aliena var.acuteserrata,Pinus tabuliformis,and P.armandii seed)placed near an edge where the forest composition changes from a pine forest to an oak forest in northwestern China.Results:We found that the seed fates differed when Quercus and Pinus seeds entered adjacent stands.In contrast to Pinus seeds,acorns that entered pine forests were characterized by higher caching rates and longer dispersal distances.Pinus seeds had the highest probability of being predated(85%)by rodents,and eleven Q.aliena var.acuteserrata seedlings were established in pine forests,although none survived in the later stages.In addition,rodents exhibited obvious selectivity in terms of the microhabitats for the seed caching sites.Conclusions:Seed fates differed when Quercus and Pinus seeds entered adjacent stands.The predation pressure by rodents on the seeds of Pinus species limited the germination of seeds and seedling establishment in oak forests.The different seed fates after their bidirectional dispersal could affect the differences in natural regeneration between pine and oak forests,and they might increase the recruitment rates for oak at the edge of an adjacent community.Rodent-mediated seed dispersal could potential unintentionally affect the competition between plant communities.

Habitat fragmentation and the population status of rodents in Abayum forest, Ikom, Cross River State, Nigeria

The threat to wildlife population is attributed to various anthropogenic activities. The main objective of this study was to identify the influence of fragment size on the population density of rodents in the study area. Fourteen (14) out of forty (40) fragments existing in the area were randomly sampled. The parameters used for the study were number, size of fragments and the corresponding population distribution of rodents in the study area. Fifty hunters in the area were also interviewed. The fragments were stratified into first, second and third order fragments on the basis of their sizes and randomly selected for the study. Indirect method of wildlife census was carried out through the observation of droppings, trail or tract, burrows, eating habits and noise. Fragment growth rate was 18 to 40 (87.5%) in 7 years. Anthropogenic perturbations in the form of cultivation of permanent cropland, settlement expansion, bush burning, timber exploitation and new settlements in areas previously thinly settled or not accessible to outsiders have resulted in disjointed ecosystems. The population density of rodents correlated with fragment size was highly significant ((P < 0.05) r = 0.9). It was then concluded that fragment size greatly influenced the population and diversity of rodent species. It was recommended that the remaining large fragments in the study area should be protected by law from further fragmentation.

Rodent models and metabolomics in non-alcoholic fatty liver disease: What can we learn?

Non-alcoholic fatty liver disease(NAFLD)prevalence has increased drastically in recent decades,affecting up to 25%of the world’s population.NAFLD is a spectrum of different diseases that starts with asymptomatic steatosis and continues with development of an inflammatory response called steatohepatitis,which can progress to fibrosis.Several molecular and metabolic changes are required for the hepatocyte to finally vary its function;hence a“multiple hit”hypothesis seems a more accurate proposal.Previous studies and current knowledge suggest that in most cases,NAFLD initiates and progresses through most of nine hallmarks of the disease,although the triggers and mechanisms for these can vary widely.The use of animal models remains crucial for understanding the disease and for developing tools based on biological knowledge.Among certain requirements to be met,a good model must imitate certain aspects of the human NAFLD disorder,be reliable and reproducible,have low mortality,and be compatible with a simple and feasible method.Metabolism studies in these models provides a direct reflection of the workings of the cell and may be a useful approach to better understand the initiation and progression of the disease.Metabolomics seems a valid tool for studying metabolic pathways and crosstalk between organs affected in animal models of NAFLD and for the discovery and validation of relevant biomarkers with biological understanding.In this review,we provide a brief introduction to NAFLD hallmarks,the five groups of animal models available for studying NAFLD and the potential role of metabolomics in the study of experimental NAFLD.

Identification and investigation of Calodium hepaticum in rodents and insectivores from Wuhan section of the Yangtze River in China

Objective:To investigate the prevalence of Calodium hepaticum(C.hepaticum)in rodents and insectivores from Wuhan section of the Yangtze River in China,and to provide evidence for the prevention and treatment of hepatic Calodium infection.Methods:Rodents and insectivores were captured from three selected Yangtze River beaches using mousetraps.The three survey sites were divided into six areas according to natural conditions,with 60 mousetraps placed in each area.The liver lesions in the captured rodents were observed by the naked eye and the eggs in the liver tissue were observed by microscopic examination.Results:A total of 1080 mousetraps were placed,and 1075 mousetraps were retrieved,with the retrieve rate as 99.5%.A total of 101 Apodemus agrarius,12 Rattus norvegicus,and 9 Crocidura attenuata were caught.The average density of rodents and insectivores was 10.5%and 0.8%,respectively.DNA of egg nodules from infected rodents showed 98%similarity with that of C.hepaticum 18 S rRNA(LC425008.1).One Rattus norvegicus was infected with C.hepaticum,with an infection rate of 3.23%in the Erqi river beach;the other two beaches did not show the incidence of C.hepaticum.Conclusions:The monitoring of C.hepaticum in the Yangtze River beaches should be strengthened to reduce the risk of human C.hepaticum infection.

Integrative rodent models for assessing male reproductive toxicity of environmental endocrine active substances

In the present review, we first summarize the main benefits, limitations and pitfalls of conventional in vivo approaches to assessing male reproductive structures and functions in rodents in cases of endocrine active substance （EAS） exposure from the postulate that they may provide data that can be extrapolated to humans. Then, we briefly present some integrated approaches in rodents we have recently developed at the organism level. We particularly focus on the possible effects and modes of action （MOA） of these substances at low doses and in mixtures, real-life conditions and at the organ level, deciphering the precise effects and MOA on the fetal testis. It can be considered that the in vivo experimental EAS exposure of rodents remains the first choice for studies and is a necessary tool （together with the epidemiological approach） for understanding the reproductive effects and MOA of EASs, provided the pitfalls and limitations of the rodent models are known and considered. We also provide some evidence that classical rodent models may be refined for studying the multiple consequences of EAS exposure, not only on the reproductive axis but also on various hormonally regulated organs and tissues, among which several are implicated in the complex process of mammalian reproduction. Such models constitute an interesting way of approaching human exposure conditions. Finally, we show that organotypic culture models are powerful complementary tools, especially when focusing on the MOA. All these approaches have contributed in a combinatorial manner to a better understanding of the impact of EAS exposure on human reproduction.

CHARACTERISTICS OF SMALL RODENT COMMUNITY IN DIFFERENT AGED CUT-OVER AREAS IN DAILING MOUNTAIN

The field investigation of small rodent community was made in Liangshui Reserve, Heilongiiang Province, in 1992. Species composition and percentage of each species of the small rodents in different aged clear-cut-over areas were analyzed. The change of rodent community was associated with the change of vegetation cover. Forest harvest, which results in change of light, temperature, water and othcr ecological factors, made change of vegetation cover and was the main cause for the change of small rodent community. The small rodents were low in number of species population and diversity index in the inatial stages after clear cutting. The diversity index of rodents in order of different aged cut-over areas were 5-year-old area >20-year-old area > 28-year-old area > 1 -year-old area > 10-year-old area.

First evidence of Bartonella phoceensis and Candidatus Mycoplasma haemomuris subsp. ratti in synanthropic rodents in Malaysia

Rodent-borne leptospirosis is by far the most common bacterial zoonosis and it is an important emerging global public health concern in Southeast Asia.Bacterial pathogens associated with rodents,especially those that live in close association with humans have been underreported.To fill this knowledge gap,the present study was undertaken to explore other neglected disease agents that can naturally infect synanthropic rodents.

Seed caching and cache pilferage by three rodent species in a temperate forest in the Xiaoxinganling Mountains

Although differences in food-hoarding tactics both reflect a behavioral response to cache pilferage among rodent species and may help explain their coexistence,differentiation in cache pilfering abilities among sympatric rodents with different hoarding strategies is seldom addressed.We carried out semi-natural enclosure experiments to investigate seed hoarding tactics among three sympatric rodent species(Tamias sibiricus,Apodemus peninsulae and Clethrionomys rufocanus)and the relationship of their pilfering abilities at the inter-and intraspecific levels.Our results showed that T.sibiricus exhibited a relatively stronger pilfering ability than A.peninsulae and C.rufocanus,as indicated by its higher recovery rate of artificial caches.Meanwhile A.peninsulae showed a medium pilfering ability and C.rufocanus displayed the lowest ability.We also noted that both cache size and cache depth significantly affected cache recovery in all three species.T.sibiricus scatter-hoarded more seeds than it larder-hoarded,A.peninsulae larder-hoarded more than scatter-hoarded,and C.rufocanus acted as a pure larder-hoarder.In T.sibiricus,individuals with lower pilfering abilities tended to scatter hoard seeds,indicating an intraspecific variation in hoarding propensity.Collectively,these results indicated that sympatric rodent species seem to deploy different food hoarding tactics that allow their coexistence in the temperate forests,suggesting a strong connection between hoarding strategy and pilfering ability.

Rodent Fauna in Southeast Forest Region of Heilongjiang Province of China and Its Damage on Agriculture and Forestry

[Objective]The paper was to understand the rodent fauna in southeast forest region of Heilongjiang Province and its harm to agriculture and forests.[Methods]The southeast forest region of Heilongjiang Province was surveyed from March2008 to December2013 using night trap method combined with integrated collation of literature. [Result]There were totally 21 species of rodents in southeast forest region of Heilongjiang Province,belonging to 16 genera,8 families,3orders,and the fauna was mainly consisted of palaearctic realm; in terms of captured number,Clethrionomys rufocanus was the dominant species in forest region,while Apodemus agrarius was the dominant species in fields. The number of rodents was closely related to stand age,and the density of rodents was lower in the forest land with longer stand age and greater density. Rodents caused greater harm to timber forest and middle-aged forest than economic forest and young forest,and their damage on newly planted seedlings was particularly greater. The number of rodent population was the highest in summer,but the smallest in spring,while its interannual changes were stable. [Conclusion]The study provided a scientific basis for forestry management and rodent control,which also offered the basic biological data for the study of rodents.