The Relationship between Shell Morphology and Crevice Size Affecting Retreat Selection of the Keeled Box Turtle(Cuora mouhotii)

Rock crevices are important retreat sites for many reptiles.Unlike lizards and snakes,crevicedwelling turtles have rigid shells which severely limit the size and shape of crevices they are able to use.Few studies have addressed the relationship between turtle's shell morphology,behavior,and crevice size.Here,we investigate the relationship between morphology and crevice size selection in the Keeled box turtle(Cuora mouhotii).We radio tracked turtles in the field to document crevice dimensions and turtle behavior associated with crevices,and we conducted a controlled experiment in the lab to understand how a turtle's morphology influences its decision to select crevices with different dimensions.Both laboratory and field experiments demonstrate that turtles select deep and moderately wide crevices that are low enough to barely accommodate the carapace.Crevices used by turtles tend to be about 2 times as wide,1.2 times as high,and 3 times longer than the turtle's shell.Moreover,turtles tended to prefer crevices with horizontal openings in the field and position themselves head first in the crevice.We conclude that morphology,especially carapace height,influences the Keeled box turtles' decision to select specific sizes of crevice.We argue that the tendency for turtles to select crevices that come into contact with their carapace contributes to successful defense against predators,as it would be more difficult for a predator to remove a turtle when the crevice is nearly touching the turtles shell.

Backward scattering of laser plasma interactions from hundreds-of-joules broadband laser on thick target

The use of broadband laser technology is a novel approach for inhibiting processes related to laser plasma interactions(LPIs).In this study,several preliminary experiments into broadband-laser-driven LPIs are carried out using a newly established hundreds-of-joules broadband second-harmonic-generation laser facility.Through direct comparison with LPI results for a traditional narrowband laser,the actual LPI-suppression effect of the broadband laser is shown.The broadband laser had a clear suppressive effect on both back-stimulated Raman scattering and back-stimulated Brillouin scattering at laser intensities below 1×10^(15) W cm^(−2).An abnormal hot-electron phenomenon is also investigated,using targets of different thicknesses.

Seasonal Variation of Hearing Sensitivity in the Red-eared Slider(Trachemys scripta elegans)

Seasonal variation of hearing sensitivity has been observed in many vertebrate groups with obvious vocal behaviors.Circulating hormones,conspecific calling signals,and temperature are potential factors that drive these plasticity patterns.Turtles have a hearing range that appears to be limited to under 1.5 kHz and are often thought to be non-vocal;thus,they are commonly neglected in vocal communication research.In this study,we aimed to determine whether the auditory phenotype exhibits seasonal variation in sensitivity and to analyze the potential factors driving such variation patterns in turtles.We measured hearing sensitivity and sex hormone levels in female(estradiol)and male(testosterone and dihydrotestosterone)Red-eared sliders(Trachemys scripta elegans)during spring and winter.The results showed that auditory brainstem response(ABR)thresholds were significantly lower in spring than in winter at a frequency range of 0.5-0.9 kHz.The hearing-sensitivity bandwidth was wider,and the ABR latency was significantly shorter in spring than in winter.No significant differences were found in estradiol,testosterone,and dihydrotestosterone levels in T.scripta elegans between spring and winter.This study is the first to reveal the seasonal variation of peripheral hearing sensitivity in turtles,a special animal group with limited hearing range and less vocalization.Temperature variations may be used to explain these seasonal effects,but further research is required to confirm our findings.

Effects of Body Size and Environmental Factors on the Acoustic Structure and Temporal Rhythm of Calls in Rhacophorus dennysi

In anurans, the outcomes of male-male contests and female choice are often associated with body size. In some species, males evaluate an opponent’s fighting ability and females evaluate male quality on the basis of male communication signals, which are thought to reflect information concerning male body size. Nevertheless, previous studies reveal that male call structure is not always correlated with body size. In the present study we investigated the relationships between body size and call structure in the large treefrog, Rhacophorus dennysi, as well as the relationship of its calling behavior with air temperature and humidity. The results show that both the dominant and fundamental frequencies are negatively correlated with body size, while inter-note intervals are positively correlated with body size, indicating that call characters could reflect body size in this species.Additionally, calling in this tropical species exhibits a circadian rhythm insofar as relatively high temperature and low humidity during the day is associated with less vocal behavior. Thus, individual variations in call structure are mainly dependent on body size while the temporal rhythm of calling activity is affected by environmental conditions in large treefrogs.

Interspecific Differences in Diet between Introduced Red-eared Sliders and Native Turtles in China

Although the alien Red-eared slider （Trachemys scripta elegans） is generally argued as an invasive species that competes with native turtles, the field evidence on its diet is controversial. Field studies conducted at the Gutian Nature Reserve of Guangdong and along the Wanquan River in Hainan, China show that T. s. elegans is an opportunitic omnivore, consuming a wide variety of food items. Consumption varies throughout its range; more plant material is consumed in Guangdong, compared to a more carnivorous diet in Hainan; and juveniles are also found to have a more carnivorous diet than adults. This implies a high adaptability to new environment. Sympatrie native Mauremys sinensis shows a more herbivorous diet and a narrower niche breadth （0.0260） in Hainan, plus a low niche overlap （0.3048） with T. s. elegans, providing a potential empty niche for the invasive T. s. elegans. Red-eared slider is also known to consume large quantities of native prey species to disrupt the ecological balance. It is imperative to understand the invasive nature of this species and the mechanisms by which it affects native ecology.

Development of low-coherence high-power laser drivers for inertial confinement fusion

The use of low-coherence light is expected to be one of the effective ways to suppress or even eliminate the laser–plasma instabilities that arise in attempts to achieve inertial confinement fusion.In this paper,a review of low-coherence high-power laser drivers and related key techniques is first presented.Work at typical low-coherence laser facilities,including Gekko XII,PHEBUS,Pharos III,and Kanal-2 is described.The many key techniques that are used in the research and development of low-coherence laser drivers are described and analyzed,including low-coherence source generation,amplification,harmonic conversion,and beam smoothing of low-coherence light.Then,recent progress achieved by our group in research on a broadband low-coherence laser driver is presented.During the development of our low-coherence high-power laser facility,we have proposed and implemented many key techniques for working with low-coherence light,including source generation,efficient amplification and propagation,harmonic conversion,beam smoothing,and precise beam control.Based on a series of technological breakthroughs,a kilojoule low-coherence laser driver named Kunwu with a coherence time of only 300 fs has been built,and the first round of physical experiments has been completed.This high-power laser facility provides not only a demonstration and verification platform for key techniques and system integration of a low-coherence laser driver,but also a new type of experimental platform for research into,for example,high-energy-density physics and,in particular,laser–plasma interactions.

Effect of Salinity on the Survival, Ions and Urea Modulation in Red-eared Slider(Trachemys scripta elegans)

To understand the tolerance to salinity and osmoregulation of the introduced Trachemys scripta elegans, the salinity stress of four groups （salinity 5‰, 15‰, 25‰ and control group） were conducted. Inorganic ions, osmotic pressure, glucose and aldosterone of blood and urine in T. s. elegans （BW： 125.60 ±19.84 g） were analyzed at 30 d, 60 d and 90 d stress. The results showed that： 1） inorganic ions concentration of blood and urine increased with ambient salinity, which indicated that high influx of ions was combined with higher outflow when exposed to saline water in T. s. elegans. However, blood aldosterone decreased with increasing salinity, which indicated that an increased sodium intake resulting in a diminished aldosterone production. However, with elapsed time, inorganic ions in urine decreased, which indicated that inorganic ions in blood would be accumulated, and Na^＋ and Cl^- in the plasma inevitably build up to harmful levels, at last death was happening when T. s. elegans was exposed to salinity 25 during 90 d salinity stress; 2） blood osmotic pressure increased as ambient salinity increased, it would reach 400 mOsm/kg in the group of salinity 25, which was about 1.5 fold of the control group. Higher blood osmotic pressure was due to both higher blood ions and urea concentrations. There may be another mechanism to avoid an excess of NaCl together with an important loss of water using one of the end-products of nitrogen metabolism; 3） blood glucose in each group except the group of salinity 5 decreased with time elapsed and with salinity increased. Therefore, we can conclude that T. s. elegans is an osmoregulator that limits the entry of Na^＋ and Cl^-, but can also tolerate certain degrees of increases in plasma Na^＋ and Cl^-. When ambient salinity was lower than 15‰, T. s. elegans can increase blood osmotic pressure by balancing the entry of NaCl with the secretion of aldosterone decreased, and by accumulating blood urea for osmoregulation effectors, and survive for at least three months. These results could provide theoretical basis for salinity tolerance and the invasion on physiological mechanism for T. s. elegans.

Comparison of rumen bacteria distribution in original rumen digesta, rumen liquid and solid fractions in lactating Holstein cows

Background： Original rumen digesta, rumen liquid and solid fractions have been frequently used to assess the rumen bacterial community. However, bacterial profiles in rumen original digesta, liquid and solid fractions vary from each other and need to be better established.Methods： To compare bacterial profiles in each fraction, samples of rumen digesta from six cows fed either a high fiber diet（HFD） or a high energy diet（HED） were collected via rumen fistulas. Rumen digesta was then squeezed through four layers of cheesecloth to separate liquid and solid fractions. The bacterial profiles of rumen original digesta, liquid and solid fractions were analyzed with High-throughput sequencing technique.Results： Rumen bacterial diversity was mainly affected by diet and individual cow（P 〉 0.05） rather than rumen fraction. Bias distributed bacteria were observed in solid and liquid fractions of rumen content using Venn diagram and LEf Se analysis. Fifteen out of 16 detected biomarkers（using LEf Se analysis） were found in liquid fraction, and these 15 biomarkers contributed the most to the bacterial differences among rumen content fractions.Conclusions： Similar results were found when using samples of original rumen digesta, rumen liquid or solid fractions to assess diversity of rumen bacteria; however, more attention should be draw onto bias distributed bacteria in different ruminal fractions, especially when liquid fraction has been used as a representative sample for rumen bacterial study.

Partial Masquerading and Background Matching in Two Asian Box Turtle Species(Cuora spp.)

Animals living in heterogeneous natural environments adopt different camouflage strategies against different backgrounds,and behavioral adaptation is crucial for their survival.However,studies of camouflage strategies have not always quantified the effect of multiple strategies used together.In the present study,we used a human visual model to quantify similarities in color and shape between the carapace patterns of two Cuora species and their preferred habitats.Our results showed that the color of the middle stripe on the carapace of Cuora galbinifrons(Indochinese box turtle)was significantly similar to the color of their preferred substrates.Meanwhile,the middle stripe on the carapace of C.mouhotii(keeled box turtle)contrasted more with their preferred substrates,and the side stripe matched most closely with the environment.Furthermore,the carapace side stripe of C.galbinifrons and the carapace middle stripe of C.mouhotii highly contrasted with their preferred substrates.We quantified the similarity in shape between the highcontrast stripes of both Cuora species and leaves from their habitats.The carapace middle stripe of C.mouhotii was most similar in shape to leaves from the broadleaves substrate,and the carapace side stripe of C.galbinifrons was the most similar in shape to leaves from the bamboo-leaves substrate.We determined that these species adopt partial masquerading when their entire carapace is exposed and partially match their background when they semi-cover themselves in leaf litter.To the best of our knowledge,this is the first study to demonstrate that partial masquerading and background matching improve the camouflage effect of Asian box turtles in their preferred habitats.This is a novel study focusing on the influence of the shape and color of individual carapace segments on reducing detectability and recognition.

Effect of Morphology and Age on the Closure Ability of Asian Box Turtles(Cuora)

The ability of box turtles to close their shell as an antipredation adaptation and the potential impact of the anterior and posterior lobes of the plastron on the closing force and closing time remain relatively unexplored.Here,keeled(Cuora mouhotii)and flowerback(C.galbinifrons)box turtles,whose shell cannot and can be completely closed,respectively,were studied.Anterior and posterior closing forces were measured using a force transducer,and the closing time was recorded.The anterior closing force in both turtle species was substantially greater than the posterior closing force,reaching approximately 4-fold in adults.Moreover,the anterior closing time in adults was significantly longer than the posterior closing time.This closing force difference can be attributed to the substantially smaller anterior plastron lobe than the posterior lobe in the two species.Additionally,the anterior and posterior closing forces in both species positively correlated with body weight and showed no relationship with the length of the bridge and hinge.Interspecies comparison showed that the anterior and posterior closing forces were significantly greater(approximately 2–4-fold)in flowerback box turtle than in keeled box turtles,regardless of age,and the closure time was significantly longer in adult flowerback box turtles than in adult keeled box turtles.Although the closing forces in both species showed negative allometry,the increase rate was significantly higher in flowerback box turtle than in keeled box turtle.The closing forces in both species were observed to be approximately 4-fold stronger in adults than in juveniles.No sexual dimorphism concerning the anterior and posterior closing forces was observed in either species.In summary,this is the first study to comparatively evaluate the anterior and posterior closing ability of box turtles,demonstrating that age,weight,plastron shape,and the degree of shell closure are important factors affecting closing ability.

Effects of Acute Temperature Stress on mRNA Expression of Transferrin in the Yellow Pond Turtle Mauremys mutica

The yellow pond turtle Mauremys mutica is widely cultured using both greenhouse-reared and outdoor pond-reared models.Individuals from the two models often show different tolerances to dramatic temperature changes caused by extreme weather events.However,the mechanism underlying the difference is unclear.In this study,we found that for greenhouse-reared turtles(GRTs),the expression levels of an immune-related gene for transferrin were significantly different(P<0.05)between the control group and the acute cold stress(ACS)group for most time points(3 h,6 h and 48 h),while at two time points(6 h and 12 h)there was a significant difference(P<0.05)between the control group and the acute heat stress(AHS)group.However,for the outdoor pond-reared turtles(OPTs),we found the opposite pattern:the ACS group showed no significant difference(P>0.05)from the control group for all time points(3 h,6 h,12 h,24 h and 48 h),whereas two time points(12 h and 24 h)were significantly different(P<0.05)for the AHS group.Our results indicate that ACS may influence the immunity of GRTs and have no influence on OPTs,whereas AHS may largely affect the immunity of OPTs and have little influence on GRTs.The findings provide insights into the mechanism underlying the different morbidity and mortality rates of turtles from different culture models after extreme weather events.

Application of Heuristic Method to the Clinical Teaching of Internal Medicine

There is an old saying,“Give a man a fish,and he will eat for a day.Teach a man to fish,and he will eat for the rest of his life.”In clinical teaching,students should not only be taught about diseases,but their intelligence should also be cultivated,along with their analytical,comprehension,and independent learning skills.The ability to solve problems enables students to think independently and acquire knowledge.This is known as the heuristic method of teaching.In this study,we mainly analyze the application value of the heuristic method in the clinical teaching of internal medicine.

Single-cell transcriptomic landscape of peripheral blood cells provides insights into adaptation of red-eared sliders(Trachemys scripta elegans)

Red-eared sliders(Trachemys scripta elegans),as one of the 100 most threatening aliens,have stronger immunity than the native species in response to environmental stress.Blood cells are an important component of immunity in the body.However,the blood cell researches of turtle are still in the traditional blood cell classification and morphological structure observation.Furthermore,turtle granulocytes cannot be accurately identified using traditional methods.Single-cell RNA sequencing techniques have been successfully implemented to study cells based on the mRNA expression patterns of each cell.The present study profiled the transcriptomes of peripheral blood cells in red-eared sliders to construct a single-cell transcriptional landscape of the different cell types and explored environmental adaptation mechanism from the perspective of hematology.All 14 transcriptionally distinct clusters(platelets,erythrocytes1,erythrocytes2,CSF1R monocytes,POF1B monocytes,neutrophils,GATA2high basophils,GATA2low basophils,CD4 T cells,CD7 T cells,B cells,ACKR4 cells,serotriflin cells,and ficolin cells)were identified in the peripheral blood cells of the red-eared sliders.In particular,a subtype of erythrocytes(erythrocytes1)that expressed immune signals was identified.Peripheral blood cells were grouped into three lineages:platelet,erythroid/lymphoid,and myeloid cell lineages.Furthermore,based on differentiation trajectory and up-regulated gene expression,ACKR4 cells were newly identified as lymphocytes,and serotriflin and ficolin cells as granulocytes.The single-cell transcriptional atlas of the peripheral blood cells in red-eared sliders provided in the present study will offer a comprehensive transcriptome reference for the exploration of physiological and pathological hematology in this species.

Hydrogen sulfide regulates abiotic stress tolerance and biotic stress resistance in Arabidopsis

Hydrogen sulfide （H2S） is an important gaseous molecule in various plant developmental processes and plant stress responses. In this study, the transgenic Arabidopsis thaliana plants with modulated expressions of two cysteine desulfhydrases, and exogenous H2S donor （sodium hydrosulfide, NariS） and H2S scavenger （hypotaurine, HT） pre-treated plants were used to dissect the involvement of H2S in plant stress responses. The cysteine desulfhydrases overexpressing plants and NariS pre-treated plants exhibited higher endogenous H2S level and improved abiotic stress tolerance and biotic stress resistance, while cysteine desulfhydrases knockdown plants and HT pre-treated plants displayed lower endogenous H2S level and decreased stress resistance. Moreover, H2S upregulated the transcripts of multiple abiotic and biotic stress-related genes, and inhibited reactive oxygen species （ROS） accumulation. Interest- ingly, MlR393-mediated auxin signaling including MIR393a/b and their target genes （TIR1, AFB1, AFB2, and AFB3） was transcrip-tionally regulated by H2S, and was related with H2S-induced antibacterial resistance. Moreover, H2S regulated 50 carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines. Taken together, these results indicated that cysteine desulfhydrase and H2S conferred abiotic stress tolerance and biotic stress resistance, via affecting the stress-related gene expressions, ROS metabolism, metabolic homeostasis, and MIR393-targeted auxin receptors.

Improvement of plant abiotic stress tolerance through modulation of the polyamine pathway

Polyamines （mainly putrescine （Put）, spermidine （Spd）, and spermine （Spin）） have been widely found in a range of physiological processes and in almost all diverse environ- mental stresses. In various plant species, abiotic stresses modulated the accumulation of polyamines and related gene expression. Studies using loss-of-function mutants and transgenic overexpression plants modulating polyamine metabolic pathways confirmed protective roles of polyamines during plant abiotic stress responses, and indicated the possibility to improve plant tolerance through genetic manipulation of the polyamine pathway. Additionally, puta- tive mechanisms of polyamines involved in plant abiotic stress tolerance were thoroughly discussed and crosstalks among polyamine, abscisic acid, and nitric oxide in plant responses to abiotic stress were emphasized. Special attention was paid to the interaction between polyamine and reactive oxygen species, ion channels, amino acid and carbon metabolism, and other adaptive responses. Further studies are needed to elucidate the polyamine signaling pathway, especially polyamine-regulated downstream tar- gets and the connections between polyamines and other stress responsive molecules.

Allele-defined genome reveals biallelic differentiation during cassava evolution

Dear Editor,Generation of heterozygous genomes by hybridization between or within species can help maintain plant diversity and serve as a potential source of new species(Baek et al.,2018).Moreover,genomic heterozygosity is associated with genomic coadaptation,developmental stability,and heterosis.Accurate definition of alleles in haplotypes is necessary to precisely characterize allelic variation controlling agriculturally important traits(Shi et al.,2019).Currently,most released genomes have mosaic assembly of haplotypes due to random selection or collapse of alleles during genome assembly(Shi et al.,2019),which masked allelic variation and functional differentiation of divergent alleles in heterozygous species.

Busuishengxue ranules mediate their effects upon non-severe aplastic anemia via mitogen-activated protein kinase/extracellular signal-regulated kinase pathway

OBJECTIVE:To observe the clinical efficacy of Busuishengxue granules on non-severe aplastic anemia(NSAA)and investigate its effect on the mitogen-activated protein kinase/extracellular signal-regulated kinase(MAPK/ERK)pathway.METHODS:Sixty NSAA patients were divided equally into two groups.Subjects in the experimental group were treated with Busuishengxue granules,and the control group with Zaizaoshengxue tablets.The treatment course was 6 months and cu-rative efficacy was compared between the two groups as well as with 10 healthy individuals.Flow cytometry(FCM)was used to detect the intracellular concentration of Ca2+([Ca2+]i).Western blotting was employed to detect the expression of enzymes in the MAPK/ERK pathway.RESULTS:The efficacy of Busuishengxue granules was significantly better than that of Zaizaoshengxue tablets(P<0.05).Before treatment,expression of JNK,phospho-ERK 1/2 and p-JNK was higher,and[Ca2+]i higher,than that of the control group(P<0.05).After treatment with Busuishengxue granules,expression of all enzymes related to signal transduction pathways in the blood cells of NSSA patients were altered to different degrees.CONCLUSION:Busuishengxue granules had a better effect with regard to improving symptom scores,increasing the number of blood leukocytes,and increasing hemoglobin levels than Zaizaoshengxue tablets,and they differed slightly in terms of increasing the number of platelets.

以急性遗忘综合征为临床表现的双侧穹隆柱梗死一例

穹隆(fornix)是起自海马内侧的投射纤维,是海马伞的延续,为海马的主要传出纤维。临床上脑梗死可表现出多种神经系统损害症状,以单纯的认知功能障碍为临床表现的脑梗死比较少见,孤立的双侧穹隆柱梗死更为罕见。现报道1例双侧穹隆柱梗死的临床表现,并复习文献,分析其病因、临床特点及预后等,以提高对穹隆柱梗死的认识。

Comparative proteomic and metabolomic analyses reveal mechanisms of improved cold stress tolerance in bermudagrass (Cynodon dactylon(L.) Pers.) by exogenous calcium

As an important second messenger, calcium is involved in plant cold stress response, including chilling（〈20 °C） and freezing（〈0 °C）. In this study, exogenous application of calcium chloride（CaCl2） improved both chilling and freezing stress tolerances, while ethylene glycol‐bis‐（b‐aminoethyl） ether‐N,N,N,N‐tetraacetic acid（EGTA） reversed CaCl2 effects in bermudagrass（Cynodon dactylon（L.） Pers.）.Pysiological analyses showed that CaCl2 treatment alleviated the reactive oxygen species（ROS） burst and cell damage triggered by chilling stress, via activating antioxidant enzymes,non‐enzymatic glutathione antioxidant pool, while EGTA treatment had the opposite effects. Additionally, comparative proteomic analysis identified 51 differentially expressed proteins that were enriched in redox, tricarboxylicacid cycle,glycolysis, photosynthesis, oxidative pentose phosphate pathway, and amino acid metabolisms. Consistently, 42 metabolites including amino acids, organic acids, sugars, and sugar alcohols were regulated by CaCl2 treatment under control and cold stress conditions, further confirming the Researchcommon modulation of CaCl2 treatment in carbon metabolites and amino acid metabolism. Taken together, this study reported first evidence of the essential and protective roles of endogenous and exogenous calcium in bermudagrass response to cold stress, partially via activation of the antioxidants and modulation of several differentially expressed proteins and metabolic homeostasis in the process of cold acclimation.

Arabidopsis PED_2 positively modulates plant drought stress resistance

Abscisic acid (ABA) is an important phytohormone that functions in seed germination, plant development, and multiple stress responses. Arabidopsis Peroxisome defective 2 (AtPED2) (also known as AtPEXOXIN14, AtPEX14), is involved in the intracellular transport of thiolase from the cytosol to glyoxysomes, and perosisomal matrix protein import in plants. In this study, we assigned a new role for AtPED2 in drought stress resistance. The transcript level of AtPED2 was downregulated by ABA and abiotic stress treatments. AtPED2 knockout mutants were insensitive to ABA-mediated seed germination, primary root elongation, and stomatal response, while AtPED2 over-expressing plants were sensitive to ABA in comparison to wide type (WT). AtPED2 also positively regulated drought stress resistance, as evidenced by the changes of water loss rate, electrolyte leakage, and survival rate. Notably, AtPED2 positively modulated expression of several stress-responsive genes (RAB18, RD22, RD29A, and RD29B), positively affected underlying antioxidant enzyme activities and negatively regulated reactive oxygen species (ROS) level under drought stress conditions. Moreover, multiple carbon metabolites including amino acids, organic acids, sugars, sugar alcohols, and aromatic amines were also positively regulated by AtPED2. Taken together, these results indicated a positive role for AtPED2 in drought resistance, through modulation of stress-responsive genes expression, ROS metabolism, and metabolic homeostasis, at least partially.