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1.
Anaesthesia ; 63(12): 1288-95, 2008 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-19032295

RESUMO

This study examined the association between pressure pain sensitivity and various single nucleotide polymorphisms (SNPs) of human micro-, kappa-, and delta-opioid receptor (i.e. OPRM1, OPRK1, and OPRD1) genes in 72 healthy adult Taiwanese women of Han Chinese race. Pressure pain threshold and tolerance were measured by an algometer and polymorphisms of the opioid receptor genes determined from blood samples. Our data revealed that pressure pain threshold, but not tolerance, in subjects with the minor allele (termed 'GA') genotype of the IVS2+31G>A polymorphism of the OPRM1 gene was significantly higher than those with major allele (termed 'GG') genotype. Neither pressure pain threshold nor tolerance between major and minor alleles of other SNPs of the OPRM1, OPRK1, and OPRD1 genes were significantly different. These data suggest an association between the IVS2+31G>A SNP of the OPRM1 gene and pressure pain sensitivity in healthy adult females.


Assuntos
Dor/genética , Polimorfismo de Nucleotídeo Único , Receptores Opioides delta/genética , Receptores Opioides kappa/genética , Receptores Opioides mu/genética , Adulto , Pressão Sanguínea/genética , Feminino , Frequência do Gene , Predisposição Genética para Doença , Genótipo , Frequência Cardíaca/genética , Humanos , Pessoa de Meia-Idade , Dor/etiologia , Limiar da Dor , Estimulação Física/métodos , Pressão/efeitos adversos , Adulto Jovem
2.
Behav Processes ; 78(3): 397-400, 2008 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-18359581

RESUMO

Subterranean termites construct underground tunnels, tens to hundreds of meters in length, in order to search for and transport resources. Diverse soil conditions surrounding the tunnels, such as soil pores and differing moisture concentrations, may cause different sized- and shaped-irregularities in the tunnels. To understand how individual termites respond to the irregularities, the present study monitored the movement of termites, Coptotermes formosanus Shiraki, in artificially excavated tunnels with rectangular irregularities of varying sizes in two-dimensional sand substrates. Termites tunneled at some of the irregularities and not at the others. The tunneling or non-tunneling behavior resulted from four different responses. The non-tunneling response may result from a behavioral adaptation that allows termites to avoid wasting energy that may be used in foraging.


Assuntos
Comportamento Animal/fisiologia , Isópteros/fisiologia , Dióxido de Silício , Animais , Comportamento Apetitivo/fisiologia , Comportamento Alimentar/fisiologia , Comportamento Alimentar/psicologia , Locomoção/fisiologia , Atividade Motora/fisiologia
3.
Sci Rep ; 8(1): 1259, 2018 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-29352238

RESUMO

Site fidelity by molting termites in Formosan subterranean termite, Coptotermes formosanus Shiraki colonies is a new addition to our understanding of lower termites' behavior and biology. Our previous studies indicated that workers moved to the central nest to molt in the presence of eggs and reproductives. The current study showed that noviflumuron-affected workers also return to the central nest and died in the vicinity of reproductives and eggs. The aversion to the dead and decaying workers caused reproductives and brood to leave the original central nest site in a colony and refuge at newer sites every few days in response to newly dead workers near them. Because mortality was an event observed only in workers undergoing molting under the effect of noviflumuron- a CSI, the death of molting individuals was observed only around reproductives and brood. This study reveals a previously undiscovered behavior of molting termites and the mechanics behind a successful arsenal; noviflumuron baits used against subterranean termites.


Assuntos
Distribuição Animal , Benzamidas/toxicidade , Hidrocarbonetos Fluorados/toxicidade , Inseticidas/toxicidade , Isópteros/fisiologia , Muda , Animais , Quitina/antagonistas & inibidores , Isópteros/crescimento & desenvolvimento , Locomoção
4.
Biosystems ; 90(3): 890-6, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17601654

RESUMO

The foraging territory of the Formosan subterranean termite, Coptotermes formosanus Shiraki, was simulated by using a lattice model in order to study how landscape structure affects the foraging territory. Three kinds of landscape were generated on lattice space: ideal, random and fractal landscape. Each lattice cell had a value ranging from 0.0 to 1.0, interpreted as transition probability, P(trans), which represents spatially distributed property of the landscapes. The heterogeneity of the fractal landscape was characterized by a parameter, H, controlling aggregation of lattice cells with higher value of P(trans). Higher H values corresponded to higher aggregation levels. The model made use of minimized local rules based on empirical data that determines the development of the foraging territory. Additionally, seasonal cycle (summer and winter season), and obstacles which hinder the growth of the territory were incorporated in the model as environmental variables. Territory size was largest in the ideal landscape while it was larger in the random landscape than in the fractal landscape. As obstacle density increased, the territory size decreased. In the fractal landscape, the territory size increased, decreased, and increased again as H increased.


Assuntos
Isópteros/fisiologia , Modelos Biológicos , Animais , Comportamento Animal/fisiologia , Comportamento Alimentar/fisiologia , Fractais , Locomoção/fisiologia , Biologia de Sistemas
5.
Biosystems ; 90(3): 802-7, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17544207

RESUMO

Subterranean termites excavate branching tunnels for searching and transporting food in soil. Experimentally, the length distribution of the branch tunnels, P(L), was characterized by the exponentially decaying function, P(L) approximately exp(-alphaL) with a branch length exponent of alpha=0.15. To evaluate the significance of this alpha value, we used a lattice model to simulate tunnels of the Formosan subterranean termite, Coptotermes formosanus Shiraki in featureless soil and computed the ratio of energy gain for obtained food to loss for transporting food for a given time, gamma for various simulated tunnel patterns with the different values of alpha. In simulation, the gamma was maximized at 0.15

Assuntos
Isópteros/fisiologia , Modelos Biológicos , Animais , Comportamento Alimentar , Alimentos , Locomoção , Biologia de Sistemas
6.
Biosystems ; 90(2): 314-22, 2007.
Artigo em Inglês | MEDLINE | ID: mdl-17070986

RESUMO

The aim of this study was to explore how a heterogeneous landscape affects food encounter rate in the Formosan subterranean termite, Coptotermes formosanus Shiraki. To do this, a lattice model was formulated to simulate the tunneling structure of the termite. The model made use of minimized local rules derived from empirical data. In addition, a landscape structure was generated on a lattice space by using a neutral landscape model. Each lattice cell has a value h, representing spatially distributed property of the landscape (e.g., temperature or moisture). The heterogeneity of the landscape was characterized by a parameter, H controlling aggregation of lattice cells with higher values of h. Higher H values correspond to higher aggregation levels. The effect of the landscape heterogeneity on the encounter rate was clear in the presence of higher food density than in lower density. The effect was also enhanced by the increase of the number of primary tunnels.


Assuntos
Isópteros/fisiologia , Ração Animal , Animais , Comportamento Animal , Meio Ambiente , Comportamento Alimentar , Alimentos , Preferências Alimentares , Modelos Biológicos , Modelos Teóricos , Biologia de Sistemas , Temperatura
7.
J Econ Entomol ; 110(6): 2512-2517, 2017 12 05.
Artigo em Inglês | MEDLINE | ID: mdl-29029069

RESUMO

Spatial assessment of molting in workers of Coptotermes formosanus Shiraki was conducted in laboratory-reared colonies using extended foraging arenas. Workers at a premolt stage were found concentrated in the nest or in a planar arena near the nest. However, molting individuals were found exclusively in the central nest and they stayed inside or near the central nest for at least 36 h postmolting. The absence of premolt workers at foraging sites suggests that the workers have an affinity to the nest for molting and the second study on nest-fidelity evaluation suggested that the workers molt in the proximity of eggs. The molting site fidelity by workers in a colony ensures that speeding up the time for mortality induced by chitin synthesis inhibitor (CSI) baits will not result in an inhibitory cascade of dead termites around the bait stations. Thus, speeding up the elimination of a C. formosanus colony using CSI baits with the addition of molt-accelerating compounds will not lead to secondary repellency. Reasons for the molting-site fidelity amongst workers in a colony are discussed.


Assuntos
Isópteros/crescimento & desenvolvimento , Muda , Animais , Controle de Insetos
8.
J Econ Entomol ; 109(5): 2175-81, 2016 10.
Artigo em Inglês | MEDLINE | ID: mdl-27567218

RESUMO

Molt frequency of workers in laboratory-reared juvenile colonies and foraging population from field colonies of Coptotermes formosanus Shiraki was determined using planar arenas in laboratory. Given that, chitin synthesis inhibitor (CSI)-incorporated baits disrupt the molting process of workers that comprises the major population of a termite colony, temporal assessment of molting frequency in workers can give insights into potential methods of reducing the time to eliminate a CSI-baited colony. In our study the 10-d observation of juvenile colonies of C. formosanus suggested average daily molting incidence of workers in a colony is 1.7 ± 0.3% (mean ± SD). The results from a time lapse study on foraging population of workers showed that on average there is a 44-d intermolt period for second-instar workers molting to third instar and 45 d for third-instar workers molting to fourth instar. At low temperature (21 °C), molting frequency of workers (0.6% per day) was significantly lower than that of workers at 27 °C (2.2% per day). Information from this study suggests that time to molt is an important component of total time for eliminating colonies treated with CSI baits and reduction in time lapse between two consecutive molts may reduce the time required for colony elimination.


Assuntos
Isópteros/crescimento & desenvolvimento , Muda , Animais , Florida , Controle de Insetos , Temperatura
9.
J Econ Entomol ; 94(6): 1518-25, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11777058

RESUMO

Sensors comprising wooden stakes painted with conductive circuits of silver particle emulsion were inserted in Sentricon stations in soil near structures. Sensors were wired to a datalogger that was programmed to test for circuit breakage every 2 h and store the data in its memory. A host computer was programmed to access the datalogger through telephone communication lines for data download every 4 d. The computerized monitoring system was tested in three remote sites, and site visits were conducted monthly for 6 mo to examine system accuracy in detecting termite activity. The mean monthly accuracy for the system to correctly report the presence (true positive) or absence of termites (true negative) in the stations was 85%, but the accuracy at 6 mo after system installation ranged from 41 to 79%. Mean sensor longevity, defined as the time for a sensor circuit to break in the absence of termites, was approximately 4.4 mo.


Assuntos
Computadores , Controle de Insetos/métodos , Isópteros , Animais , Arquitetura de Instituições de Saúde
10.
J Econ Entomol ; 94(6): 1398-404, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11777041

RESUMO

The tunneling responses of two subterranean termite species, Coptotermes formosanus Shiraki and Reticulitermes flavipes (Kollar), to the presence of sound wood in laboratory arenas were studied. Branching pattern and the speed of tunnel construction between R. flavipes and C. formosanus also were compared. Patlak's residence index (rho) was generated using the length, width, speed of construction, and area of the primary tunnels built by termites. In the same allotted time, C. formosanus built wider and shorter primary tunnels, whereas R. flavipes built thinner and longer primary tunnels. The presence of wood did not affect termite tunnel formation. This lack of variation in tunnel formation parameters was evidenced by the inability of the termites to locate wood sources over distance, even as short as 2.5 mm, and by the similar tunneling behaviors in areas of the arena with or without wood. Patlak's model predicted the densities of tunnels with an error between 9 and 28%. in experiments with R. flavipes exposed to a range of 0-8,000 g of wood, and between 61 and 87% in experiments with C. formosanus. These results indicated that the residence index can provide a qualitative measure of the effect of habitat heterogeneity on the individual termite tunnels. The tunneling constructions strategy of these subterranean termites is discussed.


Assuntos
Comportamento Animal , Isópteros/fisiologia , Animais , Modelos Biológicos , Madeira
11.
J Econ Entomol ; 93(2): 412-4, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10826193

RESUMO

A method is described in which consumption by termites of a feeding block composed of 36 thin (2-mm) wooden slats is estimated with a video image analysis. The significant regression between dry wood weight loss and decreased pixel count of digitized images demonstrates that the video image technique may be a useful tool to quantify termite feeding. Time required to measure wood consumption with the video image technique (approximately 11.5 min per sample) was significantly less than that for the manual method of washing, and weighing wooden blocks damaged by termite feeding (approximately 21.0 min per sample).


Assuntos
Isópteros , Animais , Comportamento Alimentar , Processamento de Sinais Assistido por Computador
12.
J Econ Entomol ; 93(2): 415-21, 2000 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-10826194

RESUMO

A sensor consisting of a wooden monitor painted with a conductive circuit of silver particle emulsion was placed in a monitoring station to detect feeding activity of the subterranean termite Coptotermes havilandi Holmgren. Sensor accuracy was 100% 1 mo after installation, but 9 mo after sensor placement, the rate declined to 73%. After the detection of C. havilandi in the stations, baits containing the chitin synthesis inhibitor hexaflumuron were applied in five colonies, and four colonies were eliminated within 3-5 mo. Baiting could not be completed for the remaining one colony because the site became inaccessible.


Assuntos
Benzamidas , Inseticidas , Isópteros , Hormônios Juvenis , Controle Biológico de Vetores/métodos , Animais , Compostos de Fenilureia , Feromônios
13.
J Econ Entomol ; 94(4): 915-9, 2001 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-11561852

RESUMO

Disodium octaborate tetrahydrate (DOT) dust, DOT aqueous solution, imidacloprid dust, and amorphous silica gel dust with synergized 1% pyrethrins were applied on wood surfaces to simulated attic modules. Modules (30 by 30 cm) with and without fiberglass insulation were exposed to dispersal flights of Cryptotermes brevis (Walker) in May and June of 1998 and 1999. Six months after flights, modules were disassembled and inspected for nuptial chamber location and contents. During both years, air and water control treatments contained 22.2+/-9.94 (mean +/- SD) nuptial chambers, 7.5+/-5.7 live imagos, and 2.0+/-1.4 chambers with brood. This survivorship indicated that the attic modules performed well as a colonizing platform for C. brevis. C. brevis dealates preferred constructing nuptial chambers in the crevices at the bases or tops of the modules instead of internal crevices. Modules treated in 1998 and 1999 with DOT or silica dusts contained no live termites, whereas zero of five modules treated with imidacloprid dust in 1998 and two of 20 modules treated with imidacloprid dust in 1999 contained single live incipient colonies. In 1998, 15% DOT solution, applied as a postconstruction treatment, yielded significantly fewer chambers and live termites than controls, but was not as effective as dusts in preventing successful colonization. In 1999, the DOT solution, applied as a construction-phase treatment, was equally as effective in preventing colonization as the dust treatments during that year. Results indicate that dust formulations of DOT, silica gel, and imidacloprid can be used to prevent drywood termite colonization in existing building voids and attics. Where the entire wood framing is exposed to treatment, such as during building construction, aqueous DOT solution can be equally effective as dusts in preventing colonization by C. brevis.


Assuntos
Boratos , Imidazóis , Controle de Insetos/métodos , Inseticidas , Isópteros , Animais , Feminino , Masculino , Neonicotinoides , Nitrocompostos , Madeira
14.
Acta Anaesthesiol Sin ; 39(4): 169-77, 2001 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-11840583

RESUMO

BACKGROUND: Sevoflurane is a volatile anesthetic agent with low pungency, non-irritating odor, and low blood/gas partition coefficient that makes it an attractive alternative to halothane. However, a high incidence of emergence agitation (EA) has been reported in pediatric patients after sevoflurane anesthesia. The underlying mechanism of sevoflurane-induced EA remains unclear. Rapid recovery of consciousness (emergence) from sevoflurane anesthesia has been proposed as one possible mechanism. We, therefore, hypothesized that sedatives such as midazolam may counteract sevoflurane's rapid emergence and thus reduce the incidence and the severity of sevoflurane-induced EA. METHODS: A prospective, controlled, single-blinded study was carried out in 88 ASA class I or II pediatric patients scheduled for elective outpatient surgery. Patients were assigned to receive either midazolam (oral midazolam, 0.2 mg/kg as anesthetic premedication) or saline (oral normal saline as premedication) before the conduct of anesthesia. When separation from parents was due its process was watched and evaluated. Induction of anesthesia and maintenance of anesthesia were uniform in both groups. Induction of anesthesia was made possible with 8% sevoflurane and N2O in 50% O2. Intubation was performed straight without the aid of muscle relaxant and the ventilator was set to maintain normocapnia. Anesthesia was maintained with 3% sevoflurane and N2O in 50% O2 until the surgery was over. All matters of relevant time periods were recorded (induction, surgical procedure, extubation and transportation). In the post-anesthesia care unit (PACU), adverse events, the incidence and the severity of EA, analgesic requirement, duration of PACU stay, and parental as well as PACU nurses' satisfaction were evaluated. RESULTS: A significant lower incidence and less severity of EA were noted in patients premedicated with midazolam. Less postoperaive analgesia was required in patients who had received midazolam. Although midazolam-premedicated patients remained sedated after sevoflurane anesthesia, the duration of the PACU stay was not significantly different from that of saline-treated patients. Both parents and PACU nurses were more satisfied with midazolam as premedication. No solid evidence showed that there was close correlation between the process of separation from parents and the occurrence of EA. CONCLUSIONS: Premedication with oral midazolam is safe, convenient and effective in decreasing the occurrence of sevoflurane-induced EA. It does not delay discharge from PACU and is suitable for outpatient surgery.


Assuntos
Anestesia por Inalação/efeitos adversos , Ansiolíticos/uso terapêutico , Éteres Metílicos/efeitos adversos , Midazolam/uso terapêutico , Medicação Pré-Anestésica , Agitação Psicomotora/prevenção & controle , Criança , Pré-Escolar , Humanos , Lactente , Estudos Prospectivos , Receptores de GABA-A/fisiologia , Sevoflurano , Método Simples-Cego
15.
Acta Anaesthesiol Sin ; 37(3): 133-9, 1999 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-10609346

RESUMO

Anesthesia for patients with a huge anterior mediastinal tumor is a well-known challenge and trial to all the anesthesiologists. The tumor mass which directly compresses the trachea and bronchus induces hypoxia and asphyxia, eventuating in cardiac arrest or even fatality in the process of general anesthesia. In selection of anesthetic technique, general anesthesia is deliberately avoided if not mandatory or spontaneous respiration should be strictly preserved by all means if obligatory. Our surgical colleagues are usually not so familiar with this potentially life-threatening situation as are the anesthesiologists, and bad communications and interactions between the two may court disaster. Here we reported 2 cases: the former was an immediate mortality in a youth with a giant anterior mediastinal tumor undergoing excisional biopsy of a neck mass under general anesthesia, and the latter was a successful anesthetic management in a woman with a giant mediastinal tumor receiving abdominal total hysterectomy for cervical cancer in situ under spinal anesthesia. The hazards of general anesthesia in these patients and the importance of comprehending preanesthetic preparations were reviewed and discussed. Moreover, we address that whenever one has shot his bolt still futile to improve the respiratory crisis in a case with mediastinal tumor, try to ventilate the patient in a prone position as it has clinical importance in ventilation and oxygenation.


Assuntos
Anestesia/métodos , Neoplasias do Mediastino/complicações , Adolescente , Obstrução das Vias Respiratórias/prevenção & controle , Feminino , Humanos , Masculino , Pessoa de Meia-Idade
16.
Acta Anaesthesiol Sin ; 39(1): 41-5, 2001 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-11407295

RESUMO

Venous air embolism (VAE) is not uncommon during craniotomy, but repeated attacks of VAE during a single surgical procedure is rarely seen. We report a successful intraoperative management of repeated attacks of air embolism in a patient who sustained craniotomy for intracranial hemorrhage (ICH) in prone position. A 70-year-old male suffering from hemorrhage in the right cerebellar hemisphere with impending brainstem herniation was scheduled for craniotomy. He had history of hypertension but it was not well controlled with medical treatment. Emergent craniotomy for removal of blood clot resulting from ICH was performed. During the operation, sudden decrease of end-tidal CO2 (EtCO2) level, fall of blood pressure and increase of central venous pressure (CVP) were noted. Since air bubbles were retrieved from CVP catheter venous air embolism was highly suspected. With prompt diagnosis and proper management, we successfully improved the patient's hemodynamic status and he was discharged without any sequelae. Early detection together with aggressive treatment is the only way in the management of intraoperative venous air embolism.


Assuntos
Craniotomia/efeitos adversos , Embolia Aérea/etiologia , Idoso , Humanos , Masculino , Recidiva
17.
Acta Anaesthesiol Sin ; 39(3): 139-44, 2001 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-11688105

RESUMO

Pregnancy is badly tolerated in patients with Eisenmenger's syndrome; maternal mortality with coherent fetal morbidity is high. Even with the advancement of both obstetric and anesthetic managements, the maternal mortality still exceeds 25%. Once conception occurs in patients of Eisenmenger's syndrome with severe pulmonary hypertension, interruption of pregnancy is still the best manipulation to be recommended. We report two cases of parturients with Eisenmenger's syndrome, who underwent termination of pregnancy. In this report, the obstetric and anesthetic management of this kind of parturients with Eisenmenger's syndrome has been thoroughly discussed.


Assuntos
Anestesia Obstétrica/métodos , Complexo de Eisenmenger/fisiopatologia , Complicações na Gravidez/fisiopatologia , Adulto , Feminino , Humanos , Gravidez
18.
Vet Rec ; 166(25): 786-9, 2010 Jun 19.
Artigo em Inglês | MEDLINE | ID: mdl-20562378

RESUMO

Over a nine-year period (2000 to 2008), 22 instances of dystocia and 50 normal fawnings in Formosan sambar deer (Cervus unicolor swinhoei) hinds from semi-domesticated herds were investigated. The majority of the hinds (17, 77.3 per cent) that suffered dystocia were categorised as having a body condition score (BCS) in the medium range (between 2.5 and 3.5 inclusive), indicating that there was no significant relationship between obesity (BCS >3.5) in hinds and the occurrence of dystocia. In addition, maternal body condition had no effect on the birthweight of the offspring. Among the 22 instances of dystocia, 16 of the fawns (72.7 per cent) did not survive; one of these deaths was anteparturient and the other 15 were parturient. Eighteen (81.8 per cent) of the cases of dystocia involved male fawns, and 15 (93.8 per cent) of the deaths were of male fawns (P=0.044). Nine (40.9 per cent) of the instances of dystocia resulted from maternal excitement, mainly attributable to disturbances caused by human beings. In 12 of the cases that resulted in the death of the fawn, the request for veterinary assistance had been delayed at least one day. There were six cases in which the fawns survived; these were the ones that had received assistance within six hours after the onset of parturition.


Assuntos
Animais Domésticos , Cervos , Parto Obstétrico/veterinária , Distocia/veterinária , Animais , Peso ao Nascer , Peso Corporal , Distocia/epidemiologia , Estudos de Viabilidade , Feminino , Masculino , Gravidez , Resultado da Gravidez/veterinária , Estudos Retrospectivos , Taiwan/epidemiologia , Medicina Veterinária
19.
Bull Entomol Res ; 96(2): 99-103, 2006 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-16556329

RESUMO

The mark-recapture technique is currently being used by many termite researchers. Here its two uses are explained and disentangled. Use 1 is mapping the geographical location of the colony and use 2 is estimating the number of termites in the colony. Use 2 is controversial because the accuracy of the estimates has been widely questioned. In this article, it is explained that use 1 is not controversial and that use 1 (not use 2) is the criterion that is currently being used for evaluating the efficacy of termite baits.


Assuntos
Comportamento Animal/fisiologia , Benzamidas/farmacologia , Controle de Insetos/métodos , Controle de Insetos/normas , Isópteros/fisiologia , Animais , Compostos Azo/análise , Comportamento Alimentar , Hormônios Juvenis/farmacologia , Movimento , Compostos de Fenilureia , Densidade Demográfica
20.
J Theor Biol ; 243(4): 493-500, 2006 Dec 21.
Artigo em Inglês | MEDLINE | ID: mdl-16938313

RESUMO

Subterranean termites excavate tunnels in a search pattern to encounter food in soil. To investigate the effect of food size, food distribution and the branch length of tunnels on food encounter rate we used a lattice gas model to simulate tunnels of the Formosan subterranean termite, Coptotermes formosanus Shiraki. The model made use of minimized local rules derived from empirical data to simulate termite tunnel patterns in featureless soil. Food distributions with three types (uniform, random, and clumped) were defined by using an I-index proposed by Zimmer and Johnson (1985). The food encounter rate was higher in a clumped than in non-clumped (uniform and random) distribution of food particles. When food particle size was varied in random distributions of food particles a maximum encounter rate was found, with particles of larger or smaller size being encountered less frequently. We also discussed the relationship between the branch tunnel length and the tunnel search pattern in minimizing the redundancy of overlapping branches.


Assuntos
Comportamento Alimentar , Isópteros/fisiologia , Modelos Biológicos , Animais , Comportamento Apetitivo/fisiologia , Alimentos , Solo
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