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1.
J Invertebr Pathol ; 198: 107919, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37004918

RESUMO

A new species of entomopathogenic fungus, Metarhizium indicum, which derives its species epithet after its Indian origin is reported here. The fungus was found to cause natural epizootics in leafhopper (Busoniomimus manjunathi) infesting Garcinia gummi-gutta (Malabar tamarind), an evergreen spice tree native to South and Southeast Asia, known for its use as a culinary flavourant, dietary supplement and traditional remedy for various human ailments. The fungus was found to cause more than 60% mortality in field collected insects. The identity of the new species was established based on its distinct morphological characteristics and multi-gene sequence data analyses. Phylogenetic analyses using internal transcribed spacer region (ITS), DNA lyase (APN2) and a concatenated set of four marker genes [translation elongation factor 1-alpha (TEF), ß-tubulin (BTUB), RNA polymerase II largest subunit (RPB1) and RNA polymerase II second largest subunit (RPB2)] along with marked differences in nucleotide composition and genetic distance unambiguously support our claim that the present fungus infecting Garcinia leafhopper is a new addition to the genus Metarhizium.


Assuntos
Hemípteros , Metarhizium , Humanos , Animais , Metarhizium/genética , Filogenia , Insetos/microbiologia , Índia
2.
Microbiol Res ; 243: 126645, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33221616

RESUMO

An entomopathogenic fungus was isolated from an infected larva of Conogethes punctiferalis (Guenée) (Crambidae: Lepidoptera), a highly polyphagous pest recorded from more than 120 plants and widely distributed in Asia and Oceanic countries. The fungus was identified as Metarhizium pingshaense Q.T. Chen & H.L. Guo (Ascomycota: Hypocreales) based on morphological characteristics and molecular studies. Scanning electron microscopic studies were conducted to study the infection of C. punctiferalis by M. pingshaense. Bioassay studies with purified conidial suspension proved that the isolate was highly virulent to C. punctiferalis, causing more than 86 % mortality to fifth instar larvae at 1 × 108 spores/mL, under laboratory conditions. The median lethal concentration (LC50) of the fungus against late instar larvae was 9.1 × 105 conidia/mL and the median survival time (MST) of late instar larvae tested at the doses of 1 × 108 and 1 × 107 conidia/mL were 4.7 and 6.4 days, respectively. The optimal temperature for fungal growth and sporulation was found to be 25 ± 1 °C. This is the first report of M. pingshaense naturally infecting C. punctiferalis. Isolation of a highly virulent strain of this fungus holds promise towards development of a potential mycoinsecticide against this pest.


Assuntos
Metarhizium/isolamento & purificação , Mariposas/microbiologia , Animais , Larva/crescimento & desenvolvimento , Larva/microbiologia , Metarhizium/classificação , Metarhizium/genética , Metarhizium/patogenicidade , Mariposas/crescimento & desenvolvimento , Controle Biológico de Vetores , Esporos Fúngicos/classificação , Esporos Fúngicos/genética , Esporos Fúngicos/crescimento & desenvolvimento , Esporos Fúngicos/isolamento & purificação , Virulência
3.
Rev Sci Instrum ; 89(10): 105001, 2018 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-30399736

RESUMO

The measurement of hand kinematics is important for the assessment and rehabilitation of the paralysed hand. The traditional method of hand function assessment uses a mechanical or electronic goniometer placed across the joint of interest to measure the range of joint movement. Mechanical goniometers are imprecise and lack the ability to provide a dynamic measurement; electronic goniometers are expensive and cumbersome to use during therapy. An alternative to the goniometric based assessment is to use inertial motion sensors to monitor the hand movement-these can be incorporated in a glove. In this paper, we present the design of an instrumented glove equipped with Magnetic, Angular Rate and Gravity (MARG) sensors for the objective evaluation of hand function. The instrumented glove presented in this paper is designed to assess the range of movement of the hand and also monitor the hand function during the course of hand rehabilitation. Static and dynamic calibrations were performed for the Euler angles calculated from the MARG sensors. The results are also presented for physiological flexion/extension of the wrist (relative roll), flexion/extension of elbow (relative pitch), and internal rotation/external rotation (relative yaw). The static calibration results gave mean absolute errors of 4.1° for roll, 4.0° for pitch, and 4.6° for yaw. From the dynamic calibration, the speed of response to a step change gave a convergence time of 0.4 s; sinusoidally oscillating movement gave good tracking at 0.2 Hz but exhibits overshoot errors at higher frequencies which were tested to be 1 Hz. We present the results of the calibration of the instrumented glove (one sensor pair measuring one joint angle) measuring anatomical joint angles-mean absolute errors during static calibration: 6.3° for a relative roll (wrist flexion/extension), 5.0° for relative pitch (elbow flexion/extension), and 4.5° for relative yaw (shoulder internal rotation/external rotation). The experimental results from the instrumented glove are promising, and it can be used as an alternative to the traditional goniometer based hand function assessments.


Assuntos
Mãos/fisiologia , Monitorização Fisiológica/instrumentação , Dispositivos Eletrônicos Vestíveis , Acelerometria/instrumentação , Fenômenos Biomecânicos , Calibragem , Humanos , Fenômenos Magnéticos , Movimento , Amplitude de Movimento Articular , Tremor/fisiopatologia
4.
Rev Sci Instrum ; 89(5): 055004, 2018 May.
Artigo em Inglês | MEDLINE | ID: mdl-29864878

RESUMO

Measurement of grip force is important for both exercise training and assessment of the hand during physical rehabilitation. The standard method uses a grip dynamometer which measures the force between the fingers and opposing thumb. The primary limitation of the grip dynamometer is the restriction of measurement to cylindrical grasps. Any deformation of the hand due to muscular or skeletal disease makes the grip dynamometer difficult or impossible to use. An alternative to the grip dynamometer is a sealed pneumatic object that can be gripped by the hand. Measurement of the internal pressure in the object can be related to the grip force. In this paper, we analyze such a pneumatic pressure sensing object for hand grip assessment and also describe an easy fabrication of the grip sensor. The instrumented object presented in this paper is designed to assess both the maximal voluntary grip forces and continuous grip force to monitor control of hand function during exercise under instruction from a therapist. Potential uses of such a pneumatic pressure sensing object for hand grip are in physical rehabilitation of patients following paralysing illnesses like stroke and spinal cord injury.


Assuntos
Teste de Esforço/instrumentação , Terapia por Exercício/instrumentação , Força da Mão , Calibragem , Desenho de Equipamento , Humanos , Modelos Teóricos , Pressão
5.
Microbiol Res ; 207: 153-160, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-29458849

RESUMO

An entomopathogenic fungus, Lecanicillium psalliotae strain IISR-EPF-02 previously found infectious to cardamom thrips, Sciothrips cardamomi promoted plant growth in cardamom, Elettaria cardamomum. The isolate exhibited direct plant growth promoting traits by production of indole-3-acetic acid and ammonia and by solubilizing inorganic phosphate and zinc. It also showed indirect plant growth promoting traits by producing siderophores and cell wall-degrading enzymes like, α-amylases, cellulases and proteases. In pot culture experiments, application of the fungus at the root zone of cardamom seedlings significantly increased shoot and root length, shoot and root biomass, number of secondary roots and leaves and leaf chlorophyll content compared to untreated plants. This is the first report on the plant growth promoting traits of this fungus. The entomopathogenic and multifarious growth promoting traits of L. psalliotae strain IISR-EPF-02 suggest that it has great potential for exploitation in sustainable agriculture.


Assuntos
Elettaria/crescimento & desenvolvimento , Elettaria/microbiologia , Hypocreales/metabolismo , Reguladores de Crescimento de Plantas/metabolismo , Amônia/metabolismo , Animais , Celulase/biossíntese , Clorofila/metabolismo , Hypocreales/classificação , Ácidos Indolacéticos/metabolismo , Peptídeo Hidrolases/biossíntese , Folhas de Planta/crescimento & desenvolvimento , Folhas de Planta/microbiologia , Raízes de Plantas/crescimento & desenvolvimento , Raízes de Plantas/microbiologia , Brotos de Planta/crescimento & desenvolvimento , Brotos de Planta/microbiologia , Plântula/crescimento & desenvolvimento , Plântula/microbiologia , Sideróforos/biossíntese , Microbiologia do Solo , Tisanópteros/microbiologia , alfa-Amilases/biossíntese
6.
J Invertebr Pathol ; 139: 67-73, 2016 09.
Artigo em Inglês | MEDLINE | ID: mdl-27480402

RESUMO

The incidence of auger beetle, Sinoxylon anale Lesne (Bostrichidae: Coleoptera), a destructive pest of cosmopolitan occurrence is reported for the first time on allspice trees, Pimenta dioica (L.) Merr. in Kerala, India. The insects bored through the basal region of fresh twigs resulting in dieback symptoms. Morphological characterization and sequencing of a partially amplified fragment of the mitochondrial CO1 gene (696bp) revealed the insect to be Sinoxylon anale. An entomopathogenic fungus was isolated from infected cadavers of S. anale that was identified as Beauveria bassiana (Bals.-Criv.) Vuill., sensu stricto (s.s.) (Ascomycota: Hypocreales) based on morphological and molecular studies. The partial sequences of the ITS, TUB, TEF and Bloc gene regions were sequenced. The fungus grew well in ambient room temperature conditions (28-32±2°C; 60-70% relative humidity) and the infection process on the insect was documented by scanning electron microscopy. Bioassay studies with the isolate indicated that the fungus was virulent against adult beetles as evidenced by the LC50 (3.6×10(6)conidia/ml) and ST50 values (6.8days at a dose of 1×10(7)conidia/ml and 5.8days at a dose of 1×10(8)conidia/ml, respectively). This is the first record of B. bassiana naturally infecting S. anale and the fungus holds promise to be developed as a mycoinsecticide.


Assuntos
Beauveria/patogenicidade , Besouros/parasitologia , Controle Biológico de Vetores/métodos , Animais , Microscopia Eletrônica de Varredura , Filogenia , Pimenta , Reação em Cadeia da Polimerase , Virulência
7.
J Invertebr Pathol ; 132: 135-141, 2015 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-26449395

RESUMO

Spilarctia obliqua Walker (Lepidoptera: Arctiidae) is a polyphagous insect pest damaging pulses, oil seeds, cereals, vegetables and medicinal and aromatic plants in India. The pest also infests turmeric and ginger sporadically in Kerala. We observed an epizootic caused by a nucleopolyhedrovirus (NPV) in field populations of the insects in December 2013. The NPV was purified and characterized. The isolate was tetrahedral in shape and belonged to multicapsid NPV. The REN profile of the SpobNPV genome with Pst I, Xho I and HindIII enzymes showed a genome size of 99.1±3.9 kbp. Partialpolh, lef-8 and lef-9 gene sequences of the isolate showed a close relationship with HycuNPV and SpphNPV. Phylogram and K-2-P distances between similar isolates suggested inclusion of the present SpobNPV isolate to group I NPV. The biological activity of the isolate was tested under laboratory conditions against third instar larvae of S. obliqua and the LC50 was 4.37×10(3)OBs/ml occlusion bodies (OBs) per ml. The median survival time (ST50) was 181 h at a dose of 1×10(6)OBs/ml and 167 h at a dose of 1×10(8)OBs/ml. SpobNPV merits further field evaluation as a potential biological control agent of S. obliqua, a serious pest of many agriculturally important crops in the Oriental region.


Assuntos
Mariposas/virologia , Nucleopoliedrovírus/isolamento & purificação , Animais , Agentes de Controle Biológico , Genoma Viral , Larva/virologia , Microscopia Eletrônica de Transmissão , Nucleocapsídeo/ultraestrutura , Nucleopoliedrovírus/classificação , Nucleopoliedrovírus/ultraestrutura , Filogenia
8.
Bone Joint J ; 95-B(2): 188-91, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23365027

RESUMO

Loss of proprioception following an anterior cruciate ligament (ACL) injury has been well documented. We evaluated proprioception in both the injured and the uninjured limb in 25 patients with ACL injury and in 25 healthy controls, as assessed by joint position sense (JPS), the threshold for the detection of passive movement (TDPM) and postural sway during single-limb stance on a force plate. There were significant proprioceptive deficits in both ACL-deficient and uninjured knees compared with control knees, as assessed by the angle reproduction test (on JPS) and postural sway on single limb stance. The degree of loss of proprioception in the ACL-deficient knee and the unaffected contralateral knee joint in the same patient was similar. The TDPM in the injured knee was significantly higher than that of controls at 30° and 70° of flexion. The TDPM of the contralateral knee joint was not significantly different from that in controls. Based on these findings, the effect of proprioceptive training of the contralateral uninjured knee should be explored.


Assuntos
Lesões do Ligamento Cruzado Anterior , Traumatismos do Joelho/complicações , Articulação do Joelho/fisiopatologia , Distúrbios Somatossensoriais/etiologia , Adolescente , Adulto , Ligamento Cruzado Anterior/fisiopatologia , Humanos , Suporte de Carga , Adulto Jovem
9.
Clin Neurophysiol ; 111(5): 810-20, 2000 May.
Artigo em Inglês | MEDLINE | ID: mdl-10802451

RESUMO

OBJECTIVES: The blink reflex R2 component was subjected to wavelet decomposition for time feature extraction in order to classify the functional status of patients with multiple sclerosis. METHODS: The blink reflex was recorded bilaterally with unilateral stimulation of the supra-orbital nerve in 37 normal subjects and 9 patients with multiple sclerosis (MS). The late component, R2, was subjected to time-frequency decomposition using the Daubechies-4 wavelet. Using the time-frequency coefficients, the mean time of the R2 wave as well as the standard deviation of the R2 interval were calculated in each trial. The wavelet transform enables noise reduction by allowing selective use of frequency bands with high signal-to-noise ratio for time feature extraction; therefore automatic estimation of time parameters is robust. The distribution densities of the mean and the standard deviation of the R2 wave duration for the set of trials for each subject were computed. RESULTS: An appreciable difference in the densities of the two parameters extracted in the wavelet domain was seen between normals and patients. This is in contrast to the onset latency of R2 which poorly discriminates MS patients from normals. CONCLUSION: The results suggest that the mean and standard deviation of the R2-time robustly estimated using wavelet decomposition can be used to support clinical diagnosis in tracking the functional status of patients with diseases like multiple sclerosis.


Assuntos
Piscadela , Esclerose Múltipla/diagnóstico , Esclerose Múltipla/fisiopatologia , Nervo Óptico/fisiopatologia , Automação , Diagnóstico Diferencial , Estimulação Elétrica , Eletrofisiologia/instrumentação , Eletrofisiologia/métodos , Lateralidade Funcional , Humanos , Nervo Óptico/fisiologia , Tempo de Reação , Valores de Referência
10.
J Neurophysiol ; 67(5): 1133-45, 1992 May.
Artigo em Inglês | MEDLINE | ID: mdl-1597703

RESUMO

1. The force-velocity relationship of a motor unit can provide insight into the contractile proteins of its constituent fibers as well as fundamental information about the function and use of the motor unit. Although the force-velocity profiles of whole muscle and skinned mammalian fibers have been studied, technical difficulties have prevented similar studies on motor units. A technique is presented to directly measure the velocity of shortening of individual motor units from in vivo rat soleus muscle. 2. The soleus muscles of anesthetized rats were dissected free of surrounding tissue while their nerve and blood supplies were preserved. Both tendons were cut, and the distal tendon was attached to a servomechanism to control muscle length, whereas the proximal tendon was attached to a force transducer. Single motor units were stimulated via the ventral roots. 3. The major problem encountered in measuring the force-velocity profile of a motor unit was that the force from the large number of passive fibers and connective tissue in the soleus confounded the force produced by the small number of active fibers in the motor unit. This problem was minimized by measuring active motor unit tension during an isovelocity ramp. This allowed experimental measurement of the passive tension by shortening the muscle with an identical isovelocity ramp without, however, stimulating the motor unit. Active tension was estimated by subtracting the passive tension waveform from the waveform recorded when the motor unit was active. 4. The method substantially reduced the noise from the passive fibers; however, problems remained. The probable sources of error are discussed, with the most significant being the elasticity associated with the blood and nerve connections to surrounding tissue. The elasticity prevents uniform shortening velocities along the length of the active fibers, thereby introducing a systematic bias to measurements made at high velocities. These errors are most pronounced when the data are extrapolated to determine the maximum velocity of shortening (Vmax). Determination of velocity at peak power (Vpp) is a more robust measure; however, of the 34 motor units studied, only 19 exhibited a distinct peak in the power-force curve, indicating residual noise. 5. To assess the validity of using twitch contraction time as an index of the velocity of shortening, when possible, Vmax and Vpp of each motor unit were correlated with the inverse of its twitch contraction time. The correlation was poor (r less than 0.2), indicating that, although widely used, twitch contraction time is a poor index of contractile speed.


Assuntos
Contração Muscular , Músculos/fisiologia , Animais , Masculino , Ratos , Ratos Endogâmicos , Tarso Animal , Fatores de Tempo
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