Changes in Mithun (Bos frontalis) spermatozoa during epididymal passage.

Genital organs of 10 healthy, adult Mithun bulls (6-8 years old) that were slaughtered at the dwellings of tribal people for meat were collected. Immediately after collection, spermatozoa from 3 different regions of the epididymis, i.e. the head, body and tail, were obtained to study morphological changes of the spermatozoa during passage through these regions. The prevalence of proximal cytoplasmic droplets significantly decreased from the head to the tail of the epididymis. Conversely, the percentage of distal cytoplasmic droplets increased significantly from the head to the tail region. The incidence of tailless heads rose significantly from head to body and then reduced significantly in the tail region. The percentage of total head abnormalities did, however, not change markedly, but total mid-piece and tail abnormalities differed significantly between the three epididymal regions.

Prevalence and significance of antiphospholipid antibodies in selected at-risk obstetrics cases: a comparative prospective study.

In a prospective comparative study we screened 112 women with a past history either of pre-eclampsia, eclampsia, recurrent abortion, IUGR, IUFD or abruptio placentae, with no apparent aetiology and a demographically matched cohort of 106 women having a past history of uncomplicated pregnancy outcome for the presence of antiphospholipid antibodies (aPL) and their significance. In the former group, the prevalence of aPL ranged from 10-46.87% compared with 8.49% in the later group. In women with the presence of aPL, the incidence of pre-eclampsia, early onset pre-eclampsia and abruptio placentae were 25%, 14.58% and 18.75%, respectively. In the same group, the abortion rate was 25% and live-birth rate was 64.58% with IUFD rate of 10.42%. Fetal morbidity rates were also higher in the mothers with aPL positivity, the incidence of IUGR was 27.08% and oligohydramnios was 33.33% in them. All these complications were statistically significant when compared with those of aPL negative mothers.

Control of stochastic multistable systems: experimental demonstration.

Stochastic disturbances and spikes (sudden sharp fluctuations of any system parameter), commonly observed among natural and laboratory-scale systems, can perturb the multistable dynamics significantly and become a serious impediment when the device is designed for a certain dynamical behavior. We experimentally demonstrate that suitable periodic modulation of any system parameter may efficiently control such stochastic multistability related problems. The control mechanism is verified individually with two standard models (namely, an analog circuit of Lorenz equations and a cavity-loss modulated CO2 laser), against three externally introduced disturbing signals, (namely, white Gaussian noise, pink noise, and train of spikes). Indeed, with both the systems, it has been observed that the modulation is capable to significantly control untoward jumps to coexisting attractors that otherwise would have occurred due to either of the disturbances. These results establish the robustness and wide applicability of this control mechanism in resolving stochastic multistability related problems.

Collection and characterization of semen in Mithun (Bos frontalis) bulls.

The objective of this study was to collect semen from semiwild Mithun (Bos frontalis) bulls using an artificial vagina (AV) and to determine semen characteristics. Collection of semen with an AV was attempted in five Mithun bulls using both anestrous and estrous Mithun females. No Mithun bull mounted an anestrous female Mithun during 60 trials, but satisfactory mounting, including extension of the penis, occurred in 25 trials with estrous Mithun females. In 15 of these trials, semen was successfully collected in an AV with an internal temperature of 42 to 46 degrees C. However, in 10 trials with an AV with an internal temperature of 36 to 40 degrees C, semen was not collected. Mean (+/- SEM) intervals to first mount and to ejaculation in the AV were 27.9+/-3.6 sec and 113.8+/-6.6 sec, respectively. Semen volume and pH were 3.1+/-0.35 mL and 6.59+/-0.04, and mean mass activity (scale, 0 to 4), initial sperm motility, live sperm count, sperm concentration, total number of sperm in the ejaculate, and overall sperm length were 2.2+/-0.3, 78.6+/-2.6%, 80.7+/-2.2%, 710.8+/-66.8 x 10(6)/mL, 2114+/-364.4 sperm, and 67.9+/-0.6 microm, respectively. The proportion of morphologically normal sperm was 80.6+/-0.2%, whereas the proportion with a morphologically abnormal head, midpiece, tail, and acrosome were 4.2+/-0.4%, 1.6+/-0.5%, 6.1+/-1.1%, and 7.1+/-0.9%, respectively. The mean incidence of tail-less heads and proximal and distal protoplasmic droplets were 0.5+/-0.1%, 0.3+/-0.2%, and 2.4+/-0.3%, respectively. In conclusion, we successfully collected semen from semiwild Mithun bulls with an AV maintained at 42 to 46 degrees C, and overall, the semen was within the normal range of that collected from fertile domestic bulls.

Tristability of a semiconductor laser due to time-delayed optical feedback.

We present an experimental and theoretical study of multistability of a single-mode laser subject to feedback through phase tuning and amplifier sections integrated on the same chip. Closely above threshold, a regime of tristability of continuous-wave (CW) states is found for multiple ranges of amplifier and phase currents. The separation between the tristable wavelengths agrees with the channel spacing of dense wavelength multiplexing in the C band of optical communication making the device interesting for ternary logic applications. Complementary theoretical investigations in the framework of the paradigmatic Lang-Kobayashi model provide a consistent understanding of the experimental findings and additionally yield an analytic formula expressing the maximum number of coexisting stable CW states by the linewidth-enhancement factor alpha . Tristability belongs to the alpha range from 5 to 8 in good agreement with experiment.

Potentiality of different isolates of wilt fungus Fusarium oxysporum collected from rhizosphere of tomato against root-knot nematode Meloidogyne incognita.

This investigation was undertaken to determine the effect of culture filtrates of different isolates of Fusarium oxysporum f. sp. lycopersici on mortality of Meloidogyne incognita juveniles and egg hatching. It was observed that different concentrations including standard extract (S.E), 1:10 and 1:100 dilutions of all fungal filtrates inhibited egg hatch when compared with control. Minimum mortality and maximum hatching was observed in BRT (showing least mortality) isolate of F. oxysporum, while maximum mortality and minimum egg hatching was recorded in BGT (showing maximum mortality) isolate. Larval mortality was decreased with a decrease in concentration and the least mortality was observed in 1:100 when compared with SE and 1:10. The potentiality of both the isolates (BRT and BGT) against root-knot nematode M. incognita was confirmed by the pathogenicity test on tomato. These observations confirmed that F. oxysporumisolates possesses variability in pathogenicity ranging from pathogenic to bio-control agent. The plants inoculated with BRT isolate failed to show wilt symptoms while plants inoculated with BGT isolate showed wilt indices.

Detection & molecular confirmation of a focus of Plasmodium malariae in Arunachal Pradesh, India.

BACKGROUND & OBJECTIVE: During a malaria epidemiological study in Arunachal Pradesh, Plasmodium malariae like human malaria parasites were seen in blood smears from fever cases. The study was undertaken to detect the presence of P. malariae and to confirm its identity through DNA based polymerase chain reaction approach. METHODS: Fever survey was carried out in 22 villages in Indo-Myanmar bordering district of Lohit, Arunachal Pradesh in 2005. Morphologically suspected P. malariae cases were confirmed using nested PCR based on 18S small subunit ribosomal DNA gene sequence. RESULTS: Screening of 1,995 fever cases resulted in 9 probable cases of P. malariae based on morphological identification in Chakma tribe people residing in 2 villages. Nested PCR confirmed the identity of all probable cases of P. malariae by producing diagnostic band of 144 bp. PCR method was able to detect mixed infection of P. malariae with P. vivax and with P. falciparum. INTERPRETATION & CONCLUSION: P. malariae may have been present in Arunachal Pradesh but most probably is being misdiagnosed due to its close resemblance with P. vivax, especially in ring forms. Estimation of actual case load of P. malariae in north-east India is, therefore, important with accurate species identification using molecular methods.

Management of root knot nematode on tomato through application of fungal antagonists, Acremonium strictum and Trichoderma harzianum.

Management of root knot nematode disease infecting tomato, by the use of fungal bioagents Acremonium strictum and Trichoderma harzianum isolated from egg masses of M. incognita infecting tomato has been carried out. The rhizosphere and rhizoplane of root knot nematode infested tomato revealed consistent association of Acremonium strictum. In the present study A. strictum and other fungal bioagents viz. Aspergillus niger, Paecilomyces lilacinus, Rhizoctonia solani and Trichoderma harzianum isolated earlier from egg-masses of M. incognita, identified and maintained have been investigated through in-vitro and in-vivo trials for their potentiality against M. incognita. Out of the above, isolated mycoflora A. niger was identified to be toxic against M. incognita while A. strictum and T. harzianum was found to possess both egg parasitic or opportunistic and toxic properties. A field trial with all the above fungal bioagents both alone and together showed significant promising performance by the dual treatment of A. strictum and T. harzianum in improving the health of the tomato plant with a remarkable reduction in M. incognita population.

Community practices of using bed nets & acceptance & prospects of scaling up insecticide treated nets in north-east India.

BACKGROUND & OBJECTIVE: The National Vector Borne Disease Control Programme (NVBDCP), India has been promoting and scaling up the use of insecticide-treated nets (ITNs) in the tribal dominated malarious areas of north-east India. But, information on sleeping habits, bed net ownership and use practices, and feedback of communities in ITN--targeted areas is needed for formulating a strategic framework for upscaling the coverage of ITNs. We carried out a community-based cross-sectional survey in select areas of Nagaland and Mizoram (where ITNs were introduced) along with Assam (where ITNs were not introduced) to know the response of community. METHODS: Following large scale introduction of ITNs during 2001-2002 in the north-eastern States of Nagaland and Mizoram by NVBDCP, India, a cross-sectional community-based survey was undertaken in April-May, 2003 covering 435 households of Nagaland and 464 households in Mizoram, using a structured questionnaire, to assess the demographic variables relevant to bed net use, bed net washing practices and acceptability of ITNs etc., for upscaling the coverage of ITNs in the surveyed communities. A total of 448 households in 8 villages in a non-ITN PHC area of Assam were served as the control area. RESULTS: The average bet net usage per family (2.01 to 2.65). Bed net use was mostly seasonal in Nagaland where a majority (65.1-78.7%) used bed nets only during summers and monsoon as compared to the year round use in Mizoram (83.5%) and Assam (78.9%). Frequent washing of nets was most common in Assamese communities with 77 per cent households washing their nets at least once in a month. More than two third users favoured use of ITNs over the conventional indoor residual spray of DDT for malaria control. INTERPRETATION & CONCLUSION: ITNs are widely acceptable in the user communities and a demand for ITNs is evident in the non-user communities of north-east India. Approach of treating community owned nets through an efficient service delivery mechanism will be a viable option for upscaling the ITN coverage.

Control of multistate hopping intermittency.

In multistable regimes, noise can create "multistate hopping intermittency," i.e., intermittent transitions among coexisting stable attractors. We demonstrate that a small periodic perturbation can significantly control such hopping intermittency. By "control" we imply a qualitative change in the probability distribution of occupation in the phase space around the stable attractors. In other words, if the uncontrolled system exhibits a preference to stay around a given attractor (say " A ") in comparison to another attractor (say " B "), the control perturbation creates a contrasting scenario so that attractor B is most frequently visited and consequently, the occupation probability becomes maximum around B instead of A . The control perturbation works in the following way: It destroys attractor A by boundary crisis while attractor B remains stable. As a result, even if the system is pushed by noise into the erstwhile basin of attractor A , the system does not remain there for long and therefore stays longer around attractor B . Significantly, such a change in the intermittent scenario can be obtained by a small-amplitude and slow-periodic perturbation. The control is theoretically demonstrated with two standard models, namely, Lorenz equations (for autonomous systems), and the periodically driven, damped Toda oscillator (for nonautonomous systems). Recent experiments with a cavity-loss modulated CO2 laser and an analog circuit of Lorenz equations have validated our theoretical demonstrations excellently.

Management of disease complex caused by root knot nematode and root wilt fungus on pigeonpea through soil organically enriched with Vesicular Arbuscular Mycorrhiza, karanj (Pongamia pinnata) oilseed cake and farmyard manure.

This investigation was undertaken to compare the percentage response of colonization and development of VA-Mycorrhiza (Glomus fasciculatum) on a number of pulse crops viz. cowpea, chickpea, soybean, pigeonpea and lentil under glasshouse conditions. Among the above-mentioned crops, pigeonpea exhibited the best performance and was selected for further studies. In this host the development and colonization percentage of G. fasciculatum was investigated under two separate substrates i. e. soil amended with FYM and karanj oilseed cake keeping a control treatment of field soil. A third treatment amended with karanj oilseed cake and farm yard manure (FYM) was also kept which responded best in terms of colonization percentage. This treatment showing improved plant health as well as integration with G. fasciculatum was selected as an ideal treatment for the management of disease complex caused by root knot nematode, Meloidogyne incognita and root wilt fungus, Fusarium udum on pigeonpea. Thus the treatment constituting FYM, karanj oilseed cake and VA-Mycorrhiza reduced the disease incidence caused by both maladies to a great extent with the most promising improvement in plant growth parameters as compared to all others. The present investigation, in addition to proposing an ideal eco-friendly treatment for the management of this disease complex also proposed an excellent medium for the proliferation of the obligate bio-protectant, G. fasciculatum.

Controlled destruction of chaos in the multistable regime.

Autonomous nonlinear systems commonly exhibit simultaneous coexistence, in the phase space, of chaos and stable steady states, created by subcritical Hopf bifurcation. We show that such chaotic instability can be destroyed by small-amplitude modulation of any system parameters. The chaotic attractor undergoes boundary crisis due to a modulation-induced collision with an unstable periodic orbit (UPO). Such a boundary crisis exhibits a new resonance that we refer to as "crisis resonance" in the control parameter space. Crisis resonance implies that crisis occurs at minimum modulation depth due to resonant evolutions of the UPOs and the chaotic attractor. Crisis resonance occurs close to some critical frequency (we refer to it as "crisis resonance frequency") or its multiples. The UPO frequency is a good estimate of the crisis resonance frequency. The small-amplitude parameter modulation destroys chaos in the presence of noise as well. These features are observed theoretically with the paradigm of autonomous systems, namely, Lorenz equations of thermal hydraulics and are in excellent agreement with the experimental results, obtained with an analog circuit of Lorenz equations.

Evaluation of chloroquine (CQ) and sulphadoxine/pyrimethamine (SP) therapy in uncomplicated falciparum malaria in Indo-Myanmar border areas.

Chloroquine (CQ) and sulphadoxine/pyrimethamine (SP) are two first-line antimalarials used under the existing Indian National Drug Policy in the north-eastern region of India bordering several countries including Myanmar. Although widespread resistance to antimalarials in Plasmodium falciparum has been reported from western Myanmar, information from the Indian side of the border is scarce. We studied the therapeutic response to CQ and SP at four sites in Changlang and Lohit, two administrative districts of Arunachal Pradesh bordering Myanmar. We monitored uncomplicated falciparum malaria patients after treatment with standard regimens of CQ and SP for 28 days following the revised in-vivo protocol of the World Health Organization. A total of 236 patients, 95 in the CQ group and 141 in the SP group, participated. We recorded 23.8% early treatment failures to CQ and 14.1% to SP; late clinical failures of 14.3 and 12.6%; late parasitological failures of 10.7 and 8.1% and adequate clinical and parasitological responses of 51.2 and 65.2%, respectively. The significantly different treatment failure rates seen in Chowkham (furthest from Indo-Myanmar border) and Jairampur/Nampong (nearest to Indo-Myanmar border) for chloroquine (Cox proportion hazard ratio 9.1, P<0.0001) and SP (Cox proportion hazard ratio 7.35, P=0.001) denote a non-response gradient to the two antimalarials extending from the international border. The gradient is probably indicative of the direction of movement of the drug-resistant P. falciparum parasite. The utility of chloroquine as the first-line drug under the present National Drug Policy in these areas needs reconsideration.

Therapeutic efficacy of anti-malarials in Plasmodium falciparum malaria in an Indo-Myanmar border area of Arunachal Pradesh.

BACKGROUND & OBJECTIVES: Malaria is one of the major public health problems in the north eastern region of India. Antimalarial drug resistance is widespread and one of the important causes of recent resurgence of falciparum malaria in this region. Antimalarial drugs are seen to be used sequentially one after another in many areas of the region, when therapeutic failure is observed with a drug. In view of this, the present study was undertaken to assess the therapeutic efficacy of common antimalarial drugs viz., chloroquine, sulfadoxine+pyrimethamine (S-P) and quinine, administered sequentially to the patients with Plasmodium falciparum infection in a Myanmar bordering area of Arunachal Pradesh. METHODS: A hospital based in vivo study was carried out with 53 patients with uncomplicated falciparum malaria. All patients were first treated with chloroquine and therapeutic efficacy assessed. In case of therapeutic failure of chloroquine combination drug (S-P) was given and those showing failure with S-P combination, oral quinine was administered and followed up for 28 days to assess both clinical and parasitological responses. RESULTS: Therapeutic failure was observed with chloroquine in 83.1 per cent (44 of 53) and to both chloroquine and S-P combination drug in 44.1 per cent (19/43) patients. Further, 15.8 per cent patients (3 of 19) failed to respond even to quinine. Overall, 5.7 per cent patients (3 of 53) showed unresponsiveness to all the three drugs i.e., chloroquine, S-P combination and quinine. Asexual parasite clearance and also fever clearance was slowest with chloroquine and fastest with quinine. INTERPRETATION & CONCLUSION: The findings of this study show the presence of multi drug failure P. falciparum in Jairampur-Nampong, a western Myanmar bordering area of Arunachal Pradesh. Anti malarial drug resistance is increasing in Indo-Myanmar border areas and systematic studies need to be done to review the situation.

Epidemiology of malaria outbreak (April/May, 1999) in Titabor Primary Health Centre, district Jorhat (Assam).

An investigation was undertaken of a malaria outbreak in the Primary Health Centre Titabor, district Jorhat, Assam during May/June 1999. The fever rate in the community since March 1999, was 44.4 per cent with an average case load of 2.5 per family. The fever cases peaked in the third week of May. Slide positive and slide falciparum rates in mass blood survey, in the study village were 16.1 and 14.5 per cent respectively with 90 per cent infection of Plasmodium falciparum. Males (SPR 17.5%) suffered relatively more than females (SPR 14.7%). Malaria prevalence was significantly less in individuals above 15 yr of age (SPR 11.0%) as compared to those below 15 yr (SPR 22.9%). Prevalence of malaria as well as mosquito densities in different clusters of the village were inversely related to the distance from the forested Naga hills. Anopheles minimus and A. dirus were collected in good numbers with comparatively higher densities of the former. Several factors like unusual climatic conditions, inadequate surveillance, unsatisfactory laboratory services and inadequate indoor residual insecticide spray were instrumental for the outbreak.

Filariasis in the labour population of a tea estate in Upper Assam.

Preliminary random and mass blood surveys undertaken between 2000-0100 h in a tea garden of Upper Assam revealed more than 8 per cent positivity for microfilaria (mf) of Wuchereria bancrofti. The mf carriers were considerably high among males (73) as compared to females (48). Culex quinquefasciatus was incriminated as a vector with man hour density of 68.5 in human dwellings (indoors). The detection of mf in children who had never moved from the area and filaria larvae in vector mosquitoes collected from human dwellings indicate that indigenous transmission is going on in the garden and that filariasis has become a local health problem.

Biting cycles of some potential vector mosquitos of Japanese encephalitis of Assam, India.

Biting activities of five potential vector species of Japanese encephalitis (JE) were observed in a JE affected district of Assam, India. Most of the species exhibited two peak periods of biting activity, one in early hours and other around midnight. However, in case of Culex fuscocephala several peaks were observed throughout the night.

Host feeding patterns of Culex vishnui sub group of mosquitoes in Dibrugarh district of Assam.

The host feeding patterns of three species of mosquitoes belonging to vishnui sub group, Culex tritaeniorhynchus, Culex vishnui and Culex pseudovishnui, the most prevalent species in Dibrugarh district were determined by analysing their blood meals. All 3 species were found be essentially zoophilic. High percentage of pig feeding was observed in Culex tritaeniorhynchus (40 per cent) and Culex vishnui (35.3 per cent) in comparison to other prevalent species in this area. In contrast Culex pseudovishnui another member of this group was not attracted to pigs (0.4 per cent). Few human feeds were recorded for Culex tritaeniorhynchus (0.4 per cent), Culex vishnui (0.4 per cent) and Culex pseudovishnui (0.8 per cent), indicating their occasional contact with human hosts. Considering the importance of this group as proven vectors of Japanese encephalitis the relevance of these results to JE transmission in this area are discussed.