Squirrel Research Articles

Identification of Anaplasma specise in some anima sl from Xitianmu Mountain in Zh ejiang province

Objective To identify Anaplasma species circulating among livestock and rodents from Xitianmu Mountain area in Zhejiang province , Southeastern China and to analyze variations regarding to their 16S rRNA gene.Methods Samples of spleen, liver and blood were collected to extract DNAs .The 16S rRNA gene fragments of Anaplasma species were amplified by using a nested PCR and then sequenced .Ho-mology analysis was conducted by using BLAST program .The multiple sequence alignment and phylogenetic analyses comparing with the sequences of other Anaplasma species in GenBank were conducted by using MEGA 5.0 software.Results The 16S rRNA gene fragments of Anaplasma were detected in 1 cattle, 8 goats, 5 Rattus confucianus, 1 Apodemus agrarius, 1 Berylmys bowersi and 1 squirrel out of 129 animals. The natural infection rate of Anaplasma was 13.2% in animals from Xitianmu Mountain area in Zhejiang . The alignment and phylogenetic analyses indicated that there were at least four Anaplasma species prevalent in livestock and rodents from Xitianmu Mountain area , including Anaplasma phagocytophilum, Anaplasma marginale, Anaplasma centrale and Anaplasma bovis.Moreover, there was a variant that obviously differed from Anaplasmma bovis and other Anaplasma sp.in GenBank.Conclusion The Anaplasma infection was detected among livestock and rodents from Xitianmu Mountain area in Zhejiang province .A newly discovered variant in rodents was likely to be a novel species .More close attention should be paid to Anaplasma infec-tion among human in Xitianmu Mountain area . Key words: Anaplasma; Animal infection; Gene variation

Geometric morphometric study of the skull shape diversification in Sciuridae (Mammalia, Rodentia).

It is generally accepted that the high phenotypic diversity of mammals is a combined result of developmental constraint and ecological adaptation, although the influence of these endogenous and exogenous factors varies in different mammal groups. The rodent family Sciuridae represents an ideal candidate for examining phenotypic diversity in relation to phylogeny and ecological adaptations. In the present study, we investigate the effects of phylogeny and lifestyle on the skull shape in different species of Sciuridae by applying geometric morphometric methods. In addition, we investigate the importance of allometry on sciurid skull shape, because results from geometric morphometrics sometimes dispute those of traditional morphometry. Here, we identify significant associations between patristic distances obtained from molecular phylogeny and shape distances in all 3 views of the cranium and the lateral view of the mandible. Multivariate regression demonstrates that shape differences among lifestyle categories are substantial, especially in the dorsal and ventral structures after the influence of phylogeny is taken into account. Allometry plays an important role in the shape variation, although its importance on different skull structures varies. Our results indicate that complex structures of this highly diverse mammal group, which occupies different niches, are affected by ecological factors and developmental constraint.

Effect of Gonadotropins and Gonadal Steroids (17β-Estradiol and Testosterone) on Harderian Gland Porphyrin Content and Circulatory Hormones in Indian Palm Squirrel Funambulus pennanti

Mostly studied in the hamster, the Harderian gland (HG, an extra-orbital gland) has been shown to be capable of melatonin (MEL) synthesis and to possess steroid receptor binding sites. Sexual dimorphism and ability to respond to steroid hormones have been reported for HG of some temperate zone mammals. However, to date there is no report on functional relation of HG with pineal, pituitary and gonad in any rodent. Hence, we tested the effect of gonadotropins [FSH (10μg) + LH (10μg)] and steroids [testosterone (100μg) and 17-β estradiol (50μg)] on HG function in relation to the activities of the pineal gland and gonad in both sexes of Indian palm squirrel Funambulus pennanti during the sexually quiescent phase. In general, squirrels treated with gonadotropins and gonadal steroids showed a significant increase in gonadal weight and decrease in pineal weight and plasma melatonin level in LH- and testosterone-treated groups only. There was no change in the weight of HG on FSH treatment. Porphyrin content of HG decreased after testosterone and estradiol treatment. Pineal gland weight invariably decreased after treatment with gonadotropins and testosterone. Plasma testosterone and estradiol levels increased but melatonin level decreased in all treated groups. Our data suggest that in this tropical rodent gonadotropins have an indirect effect on HG and that gonadal steroids have significant effect on HG through the influence on gonadal and pineal functions.

Diagnosis of Stator Winding Short Circuit Fault in Three Phase Squirrel Cage Induction Machine

The objective of this paper is stator winding fault detection in three phase squirrel cage induction motor using Motor Current Signature Analysis (MCSA). A prototype model of the motor has been designed to study the stator winding faults through simulation and experimentation. Simulation has been carried out using MagNet 6.11.2. The simulated stator winding faults are inter-turn, phase-to-phase, open turn in a phase. The current signatures of simulation and hardware has been compared.

Phenology of hibernation and reproduction in ground squirrels: integration of environmental cues with endogenous programming

AbstractMammalian hibernation is characterized by prolonged dormancy consisting of pronounced depression of metabolism and body temperature. Though hibernation occurs in at least seven mammalian orders and several families of the order Rodentia, the ecology and physiology of hibernation in rodents has been most extensively studied in the family Sciuridae, particularly in the so‐called ground squirrels, that is, the tribe Marmotini. Early studies of these rodents demonstrated the important role of an endogenous circannual clock in the persistence of annual timing and phasing of key seasonal events, including weight gain, hibernation and reproduction. Here, we review the causes and consequences of intraspecific variation in the timing of hibernation and reproduction in these sciurids and examine the physiological mechanisms that contribute to phenotypic plasticity in seasonal timing. Although the duration, annual phasing and predictability of seasonal change in environmental conditions likely promoted the evolution of endogeneity, precision and brevity of breeding seasons in the annual cycles of sciurids, substantial intraspecific variation in hibernation and reproductive phenology exists along latitudinal and altitudinal clines, as well as among locally varying environmental micro‐conditions. We suggest that much of this variation is a function of plasticity in the physiological mechanisms controlling annual cycles. While studies of captive animals have been instrumental in establishing the role of an endogenous rhythm, a greater emphasis on experimental field manipulations is needed to better understand the function, causes and consequences of phenological shifts in wild populations. Ultimately, the capacity of hibernators to adjust their timing in response to changing environmental conditions, either through phenotypic plasticity or microevolution, will be an important determinant of the resilience of sciurid species to changing climate.

Hemoglobin function and allosteric regulation in semi-fossorial rodents (family Sciuridae) with different altitudinal ranges

Semi-fossorial ground squirrels face challenges to respiratory gas transport associated with the chronic hypoxia and hypercapnia of underground burrows, and such challenges are compounded in species that are native to high altitude. During hibernation, such species must also contend with vicissitudes of blood gas concentrations and plasma pH caused by episodic breathing. Here, we report an analysis of hemoglobin (Hb) function in six species of marmotine ground squirrels with different altitudinal distributions. Regardless of their native altitude, all species have high Hb-O2 affinities, mainly due to suppressed sensitivities to allosteric effectors [2,3-diphosphoglycerate (DPG) and chloride ions]. This suppressed anion sensitivity is surprising given that all canonical anion-binding sites are conserved. Two sciurid species, the golden-mantled and thirteen-lined ground squirrel, have Hb-O2 affinities that are characterized by high pH sensitivity and low thermal sensitivity relative to the Hbs of humans and other mammals. The pronounced Bohr effect is surprising in light of highly unusual amino acid substitutions at the C-termini that are known to abolish the Bohr effect in human HbA. Taken together, the high O2 affinity of sciurid Hbs suggests an enhanced capacity for pulmonary O2 loading under hypoxic and hypercapnic conditions, while the large Bohr effect should help to ensure efficient O2 unloading in tissue capillaries. In spite of the relatively low thermal sensitivities of the sciurid Hbs, our results indicate that the effect of hypothermia on Hb oxygenation is the main factor contributing to the increased blood-O2 affinity in hibernating ground squirrels.

The Mammals of Sriharikota Island, Southern India, with Insights into their Status, Population, and Distribution

Inventory surveys, transect surveys (day), and roadside surveys (night) were carried out from November 2001 to October 2007, to document the mammalian fauna of Sriharikota and assess their population and distribution in the island. The surveys covered four habitat types, namely tropical dry evergreen forest (TDEF), open scrub, eucalyptus, and casuarina plantations. Twenty-eight species of mammals were recorded; most of which are common or widely distributed in India. The records of the Rusty-spotted Cat Prionailurus rubiginosus and Grey Slender Loris Loris lydekkerianus in Sriharikota are of conservation interest. The Bonnet Macaque Macaca radiata and the nocturnal Small Indian Civet Viverricula indica were not recorded in plantations. The encounter rate of the Three-striped Palm Squirrel Funambulus palmarum was higher in forests than in plantations (Mann-Whitney U=1067, p<0.001), and within the natural habitat, it was more in TDEF than in open scrub (Mann Whitney U=288.0, p<0.05). The encounter rates of the Golden Jackal Canis aureus and Indian Hare Lepus ( Indolagus ) nigricollis were higher in natural habitat than in plantations (Mann-Whitney U=1390, p<0.01 and U=1536, p<0.05, respectively). The takeover of the Island by the Indian Space Research Organisation (ISRO) and its high security status has overall been a boon for the wildlife and their habitats. However, the issue of plantations, and expansion plans of the spaceport that will involve loss of forests are threats that call for a long-term conservation plan.

Squirrels of the World by R. W. Thorington Jr., J. L. Koprowski, M. A. Steele, and J. F. Whatton

Thorington, R. W., Jr., J. L. Koprowski, M. A. Steele, and J. F. Whatton. 2012. Squirrels of the World. Johns Hopkins University Press, Baltimore, Maryland, 459 pp. ISBN-13 978-1-4214-0469-1, price (hardbound), $75.00.

A New Direct Torque Control Algorithm for Torque and Flux Ripple Reduction

In this study, a novel direct torque control (DTC) algorithm is developed to decrease torque ripple, electromagnetic noise and harmonics in the three phase squirrel caged induction motors. The space vectors of the conventional DTC method, the position of the stator flux vector and deviation from the reference flux are utilized to construct the new algorithm. Switching time of the vectors in the proposed algorithm is determined from a switching table which is based on the flux error. Switching time pairs in the table are selected using the flux error and the position of the sector. This table eliminates need for complex mathematical operations to determine the switching time of the space vectors in the induction motors and maximizes the performance of the algorithm. The algorithm is simulated and tested by an experimental setup. Simulation and experimental results suggest that the proposed algorithm decreases torque ripple and current harmonic and it has adequate dynamic and steady-state torque performance. Compared to the conventional DTC, the new algorithm has lower EMI noise level

Babies of stressed squirrels grow faster

Babies of stressed squirrels grow faster

Detection of Eccentricity in Squirrel Cage Induction Motors by Finite Element Method

Finite Element method is used in this research work to detect eccentricity fault in squirrel cage induction motors. This paper is about the results obtained from the simulation part of the research on a real size motor. The simulation was done using FLUX software, which can solve the magnetizing partial differential equations of the rotor, stator and the air-gap by FEMM. In the primary stage of this research the focus is on two dimension mapping of the electromagnetic field of the motor by using FLUX-2D. The presented results in this paper show the effect of the eccentricity is traceable from the FEMM of the motor. At the later part of this paper, the results from the simulation part were tested against the analytical method for validation. In the analytical method the present research was concentrated on the stator current and sees how the original sinusoidal current signal is distorted after fault. At the final part of the paper a complete FFT analysis of the current and voltage were presented for two cases of static and dynamic eccentricity faults. The paper is concluded by showing the effectiveness of this research for eccentricity fault diagnoses.

Squirrels of the world

Squirrels of the world

Diversity and abundance of Small Mammals in Giritale Nature Reserve

The composition of small mammal communities in forest, shrub land, grassland and anthropogenic habitats of the Giritale Nature Reserve of north central Sri Lanka was studied from June 2006 to August 2007 to estimate the abundance and diversity of small mammals inhabiting this nature reserve. Live trapping using Sherman traps and Pitfall traps were adopted to catch the small mammals. A total of 71 individuals representing two orders (Insectivora and Rodentia) and three families (Soricidae, Muridae, Scuridae) was captured. Species recorded included Suncus murinus murinus Linnaeus, 1766 (Common Indian Musk Shrew), Mus cervicolor fulvidiventris Blyth, 1852 (Ceylon Field Mouse), Mus mus culuscastaneus Waterhouse, 1843 (Indian Field Mouse), Mus fernandoni Phillips, 1932 (Ceylon Spiny Mouse), Rattus blanfordi Thomas, 1881 (White Tailed Rat), Funambulus palmarum Linnaeus, 1766 (Indian Palm Squirrel) and Rattus rattus. The species Rattus rattus consisted of two subspecies Rattus attusrattus Linnaeus, 1758 (Common House Rat) and Rattus rattus rufescens Gray, 1837 (Indian House Rat). Highest and lowest abundances were recorded in the grasslands (0.08) and shrub lands(0.01), respectively. Highest diversity index was recorded in anthropogenic habitats (1.62), which included paddy fields, home gardens and buildings, while lowest diversity index was recorded in shrub lands (0.67). The number of small mammals captured was significantly different in the four habitat types (χ2 = 22.69, df = 3, p<0.05). This study, which is the first detailed examination of terrestrial small mammals in a dry zone forest of Sri Lanka, indicated that the Giritale Nature Reserve is home to six species of small mammals. Key words: Abundance, Diversity, Evenness, Nature reserve, Small mammals

Flying in the Face of the Endangered Species Act? Delisting the West Virginia Northern Flying Squirrel

Flying in the Face of the Endangered Species Act? Delisting the West Virginia Northern Flying Squirrel

How do grey squirrels remember the location of their food caches

How do grey squirrels remember the location of their food caches

No evidence for proteolytic venom resistance in southern African ground squirrels

Many mammalian species that interact with venomous snakes show resistances to venoms. The family Sciuridae has several North American members that harass venomous snakes and show proteolytic resistances in their sera. We examined sera collected from an African ground squirrel (Xerus inauris) against two sympatric venomous snakes (Bitis arietans and Naja annulifera) and found no support for proteolytic resistance. Our results add to our understanding of the risks in predator defense within the family Sciuridae.

Gliding Mammals: Taxonomy of Living and Extinct Species

There are 64 species of extant gliding mammals that are currently recognized, which are divided into six different families. These comprise eight species of gliding marsupials that live within Australasia and include six species of lesser gliding possums of Petaurus (family Petauridae), one species of greater glider of Petauroides (family Pseudocheiridae), and one species of feathertail glider of Acrobates (family Acrobatidae). The flying squirrels of the tribe Pteromyini within the rodent family Sciuridae represent the greatest diversity of gliding mammals, with a total of 48 species in 15 genera currently recognized, and occur throughout Asia, Europe, and North America. A second group of gliding rodents, known as the scaly-tailed flying squirrels, comprises six species from the family Anomaluridae that live in central and western Africa. The most specialized and unique of the extant gliding mammals are the enigmatic colugos, or flying lemurs, of the order Dermoptera that comprise two species and occur throughout Southeast Asia and the Philippines. In addition to the extant species there are various fossils of extinct species that are thought to have had an ability to glide, although there has been a lot of debate over most of these taxa. These fossil taxa include 3 marsupials, 18 dermopterans, 51 flying squirrels, 7 species of scaly-tailed flying squirrels, and 1 extinct species in each of the families Myoxidae, Eomyidae, and Volaticotheriidae. The taxonomic status of many living and extinct gliding mammals is still in a state of flux, and significant further revision of the taxonomic status of many groups still needs to be resolved.

The even darker side of the eastern gray squirrel ( Sciurus carolinensis ): a review of global introductions, invasion biology, and pest management strategies

Huynh, H.M., Bertolino, S., Lurz, P.W.W., Koprowski, J.L., Williams, G.R., Thompson, C.W., McAlpine, D.F.

Implementation of proportional integral (PI) controlled DSP based cost effective inverter fed speed control of induction motor drive with VisSim/ embedded controls and developer (ECD)

Real-time implementation of PI controller based cost effective inverter fed speed control of induction motor drive using high performance TMS320F2812 DSP with VisSim/ embedded controls and developer (ECD) is presented in this paper. The four switch three-phase inverter (FSTPI) fed drive system consists of a power circuit having an insulated gate bipolar junction transistor (IGBT) based bridge inverter module feeding a 5 hp three-phase squirrel cage induction motor and control circuits that comprises of digital signal processor (DSP), processor board, driver circuit, sensor (for sensing speed signals), interfacing circuits and PC with VisSim/ECD software. The PI controller block and PWM generation block of this drive system are designed using VisSim/ECD to control the speed of induction motor in closed loop. Observations are made by changing speed of motor at different loads. Results obtained from this experimental work are satisfactory and shown using GUI of VisSim /ECD software and digital storage oscilloscope. Key words: Four switch three-phase inverter (FSTPI), digital signal processor (DSP), proportional integral (PI), Sinusoidal pulse width modulation (SPWM) and VisSim/ embedded controls and developer (ECD).

Isolation of Jamestown Canyon and snowshoe hare viruses (California serogroup) from Aedes mosquitoes in western Massachusetts.

Three isolates of Jamestown Canyon virus and one isolate of snowshoe hare virus (California serogroup) were obtained from adult Aedes females collected in western Massachusetts in 1982. Jamestown Canyon virus was isolated from Aedes abserratus/punctor once, and from Aedes intrudens twice. Snowshoe hare virus was isolated from Aedes stimulans group mosquitoes. La Crosse encephalitis (LAC) virus was not isolated from 1,552 adult Aedes triseriatus, nor from 22,557 Aedes triseriatus larvae. However, sera from 1/178 eastern chipmunks, 5/31 gray squirrels, and 8/144 white-tailed deer had neutralizing antibody to LAC virus. No sentinel rabbits placed at sites yielding virus isolates seroconverted to CAL viruses in either year.