Self-Transport and Manipulation of Aqueous Droplets on Oil-Submerged Diverging Groove.

We report experimental study of self-transport of aqueous droplets along an oil-submerged diverging groove structure. The migration phenomenon is illustrated, and the effect of various parameters such as droplet size d, oil layer thickness h, groove angle 2θ, and groove thickness δ on the droplet transport behavior (i.e., migration velocity and length) is investigated. Our study reveals that complete engulfment of aqueous droplets in the oil layer, that is attributed to a positive spreading parameter ( S > 0), is a prerequisite for the droplet transport. The results show that only droplets of diameter larger than the oil layer thickness (i.e., d ≥ h) get transported owing to a differential Laplace pressure between the leading and trailing faces of a droplet because of the diverging groove. Using experimental data, the variation of droplet migration velocity with distance along the diverging groove is correlated as U( x) = ψ x-0.9, where ψ = d0.32θ-2.2 h-1.5δ0.7. The submerged groove structure was used to demonstrate simultaneous and sequential coalescence and transport of multiple droplets. Finally, the submerged groove structure was employed for extraction of aqueous droplets from oil. The proposed technique opens up a new avenue for evaporation and contamination free transport and coalescence of droplets for chemical and biological applications.

Dynamics of a Water Droplet over a Sessile Oil Droplet: Compound Droplets Satisfying a Neumann Condition.

We report the dynamics of compound droplets with a denser liquid (water) droplet over a less dense sessile droplet (mineral oil) that satisfies the Neumann condition. For a fixed size of an oil droplet, depending on the size of the water droplet, either it attains the axisymmetric position or tends to migrate toward the edge of the oil droplet. For a water droplet-to-oil droplet at volume ratio Vw/Vo ≥ 0.05, stable axisymmetric configuration is achieved; for Vw/Vo < 0.05, migration of water droplet is observed. The stability and migration of water droplets of size above and below critical size, respectively, are explained using the force balance at the three-phase contact line and film tension. The larger and smaller droplets that initially attain the axisymmetric position or some radial position, respectively, evaporate continuously and thus migrate toward the edge of the oil droplet. The radial location and migration of the water droplets of different initial sizes with respect to time are studied. Experiments with water droplets on a flat oil-air interface did not show migration, which signified the role of the curved oil-air interface for droplet migration. Finally, coalescence of water droplets of size above the critical size at the axisymmetric position is demonstrated. Our compound droplet studies could be beneficial for applications involving droplet transport where contamination due to direct contact and pinning of droplets on solid surfaces is of concern. Migration and coalescence of water droplets on curved oil-air interfaces could open new frontiers in chemical and biological applications including multiphase processing and biological interaction of cells and atmospheric chemistry.

Prioritizing areas for malaria control using geographical information system in Sonitpur district, Assam, India.

OBJECTIVE: To identify the malaria hot spots at health subcentre level in an endemic district using a geographical information system (GIS). The results will be useful for rapid retrieval of malaria information, and to prioritize malaria control efforts in identified hot spots. STUDY DESIGN: Extraction, analysis and synthesis of relevant data. METHODS: Malaria epidemiological data from 2006 to 2009 were analysed to determine the annual parasitic index, slide positivity rate, annual blood examination rate and Plasmodium falciparum percentage for each health subcentre in the district. Maps were produced using GIS, and integrated to identify the malaria hotspots. RESULTS: Out of 288 health subcentres, GIS identified 10 hot spots at extremely high risk of malaria and 14 hot spots at high risk of malaria. Malaria may flare up in these hot spots whenever favourable transmission conditions arise. Health authorities have been advised to establish control measures in these selected hot spots for timely prevention. CONCLUSION: There is a need for adequate monitoring and allocation of available resources for better interventions in the malaria hotspots. The GIS model used in this study can be used, even at village or cluster level, to pin point the malaria hot spots, and information can be updated and retrieved easily.

Acute cannabis use causes increased psychotomimetic experiences in individuals prone to psychosis.

BACKGROUND: Epidemiological evidence suggests a link between cannabis use and psychosis. A variety of factors have been proposed to mediate an individual's vulnerability to the harmful effects of the drug, one of which is their psychosis proneness. We hypothesized that highly psychosis-prone individuals would report more marked psychotic experiences under the acute influence of cannabis. METHOD: A group of cannabis users (n=140) completed the Psychotomimetic States Inventory (PSI) once while acutely intoxicated and again when free of cannabis. A control group (n=144) completed the PSI on two parallel test days. All participants also completed a drug history and the Schizotypal Personality Questionnaire (SPQ). Highly psychosis-prone individuals from both groups were then compared with individuals scoring low on psychosis proneness by taking those in each group scoring above and below the upper and lower quartiles using norms for the SPQ. RESULTS: Smoking cannabis in a naturalistic setting reliably induced marked increases in psychotomimetic symptoms. Consistent with predictions, highly psychosis-prone individuals experienced enhanced psychotomimetic states following acute cannabis use. CONCLUSIONS: These findings suggest that an individual's response to acute cannabis and their psychosis-proneness scores are related and both may be markers of vulnerability to the harmful effects of this drug.

The excitable signal transduction networks: movers and shapers of eukaryotic cell migration.

In response to a variety of external cues, eukaryotic cells display varied migratory modes to perform their physiological functions during development and in the adult. Aberrations in cell migration result in embryonic defects and cancer metastasis. The molecular components involved in cell migration are remarkably conserved between the social amoeba Dictyostelium and mammalian cells. This makes the amoeba an excellent model system for studies of eukaryotic cell migration. These migration-associated components can be grouped into three networks: input, signal transduction and cytoskeletal. In migrating cells, signal transduction events such as Ras or PI3K activity occur at the protrusion tips, referred to as 'front', whereas events such as dissociation of PTEN from these regions are referred to as 'back'. Asymmetric distribution of such front and back events is crucial for establishing polarity and guiding cell migration. The triggering of these signaling events displays properties of biochemical excitability including all-or-nothing responsiveness to suprathreshold stimuli, refractoriness, and wave propagation. These signal transduction waves originate from a point and propagate towards the edge of the cell, thereby driving cytoskeletal activity and cellular protrusions. Any change in the threshold for network activation alters the range of the propagating waves and the size of cellular protrusions which gives rise to various migratory modes in cells. Thus, this review highlights excitable signal transduction networks as key players for coordinating cytoskeletal activities to drive cell migration in all eukaryotes.

Cerebral organoids reveal early cortical maldevelopment in schizophrenia-computational anatomy and genomics, role of FGFR1.

Studies of induced pluripotent stem cells (iPSCs) from schizophrenia patients and control individuals revealed that the disorder is programmed at the preneuronal stage, involves a common dysregulated mRNA transcriptome, and identified Integrative Nuclear FGFR1 Signaling a common dysregulated mechanism. We used human embryonic stem cell (hESC) and iPSC-derived cerebral organoids from four controls and three schizophrenia patients to model the first trimester of in utero brain development. The schizophrenia organoids revealed an abnormal scattering of proliferating Ki67+ neural progenitor cells (NPCs) from the ventricular zone (VZ), throughout the intermediate (IZ) and cortical (CZ) zones. TBR1 pioneer neurons and reelin, which guides cortico-petal migration, were restricted from the schizophrenia cortex. The maturing neurons were abundantly developed in the subcortical regions, but were depleted from the schizophrenia cortex. The decreased intracortical connectivity was denoted by changes in the orientation and morphology of calretinin interneurons. In schizophrenia organoids, nuclear (n)FGFR1 was abundantly expressed by developing subcortical cells, but was depleted from the neuronal committed cells (NCCs) of the CZ. Transfection of dominant negative and constitutively active nFGFR1 caused widespread disruption of the neuro-ontogenic gene networks in hESC-derived NPCs and NCCs. The fgfr1 gene was the most prominent FGFR gene expressed in NPCs and NCCs, and blocking with PD173074 reproduced both the loss of nFGFR1 and cortical neuronal maturation in hESC cerebral organoids. We report for the first time, progression of the cortical malformation in schizophrenia and link it to altered FGFR1 signaling. Targeting INFS may offer a preventive treatment of schizophrenia.

Typing of Plasmodium falciparum DNA from 2 years old Giemsa-stained dried blood spots using nested polymerase chain reaction assay.

A panel of 129 Giemsa-stained thick blood spots (TBS) confirmed for Plasmodium falciparum infection having different levels of parasite density were collected from a malaria endemic area. DNA was extracted and nested polymerase chain reaction (PCR) assay was performed to amplify P. falciparum DNA. Nested PCR assay successfully amplified P. falciparum DNA at a very low parasitaemia of ~10 parasites/µl of blood. Current PCR assay is very simple and can be used retrospectively to monitor the invasion and prevalence of different Plasmodium species in endemic areas.

Effectiveness of puncture-aspiration-injection-reaspiration in the treatment of hepatic hydatid cysts.

BACKGROUND: Hydatid disease of the liver is endemic in cattle rearing areas of the world. A variety of treatment options are available in its management. The common treatment options are medical therapy, surgery and puncture-aspiration-injection-reaspiration (PAIR) therapy. OBJECTIVES: This study was performed to evaluate the effectiveness of PAIR therapy in the treatment of hepatic hydatid disease. PATIENTS AND METHODS: This cross sectional study was carried out on 15 consecutive patients (Male: 2, Female: 13; Age group: 11-80 years) with hepatic hydatid disease and were treated by PAIR therapy and followed up for a period of 1 year. The cysts were punctured under local anesthesia with an 18G needle using sonographic guidance. Betadine (10% povidone iodine + 1% free iodine) was used as scolicidal agent and allowed to act for 30 min. Cysts larger than 5 cm (n = 5) were drained using an 8F pig tail catheter. The therapeutic response was studied by assessing the reduction in the cyst size, progressive solidification of the cyst, calcification of the wall and increase in the echogenicity of the cyst with pseudomass appearance on serial ultrasound examinations performed on the next day, after 1 month, at 3 months, 6 months and 1 year after the procedure. RESULTS: Ten patients (66.7%) had Gharbi type I cysts, two (13.3%) had type II and three (20%) had type III cysts. All the patients (100%) showed reduction in cyst size over a 3-6 month period. Pseudomass appearance with solidification was seen in 73% of the patients and calcification was seen in 46.6%. None of the patients developed anaphylaxis, recurrence or peritoneal seedlings. Pain at the injection site was the most common complication observed. CONCLUSION: PAIR therapy is an effective minimally invasive treatment for Gharbi type I-III hepatic hydatid cysts. It is a cost effective and safe procedure with significant reduction in the duration of hospital stay.

Epidemiology and Risk Analysis of Malaria among Pregnant Women.

Malaria remains a complex problem during the pregnancy, which threatens > 35 millions pregnant women every year. Malaria pathogenesis in pregnancy results in accumulation of infected RBCs in the intervillous spaces causing severe alterations leading to the reduced materno-foetal exchanges. In this article we have revisited the current evidences of clinical implications and overall burden of malaria in pregnancy. Many adverse aftermaths including, low birth weight, intrauterine growth retardation, preterm delivery, stillbirth and anemia were found associated with malaria in pregnant women. Despite of worldwide comprehensive control programmes for malaria in pregnancy, the disease control has been a daunting task everywhere. Socio cultural, economical, lack of awareness and various logistic problems compound the disease in developing countries. Thorough evidence based information and estimates, education and awareness and strengthening of prevention programmes are needed urgently to achieve success in malaria control in pregnancy.

Modification in the expression of Mre11/Rad50/Nbs1 complex in low dose irradiated human lymphocytes.

Despite the fact that high doses of radiation are detrimental, low dose radiation (LDR) often protects the organism against a subsequent exposure of lethal doses of radiation. Present study was undertaken to understand the role of Mre11, Rad50 and Nbs1 genes in the low dose radio-adapted human peripheral blood mononuclear cells (PBMCs). Optimum time interval between low dose (0.07 Gy) and high dose (5.0 Gy) of (60)Co-gamma-radiation was observed to be 5.0 hours, at which PBMCs showed maximum LDR induced resistance (RIR). At cytogenetic level, micronuclei frequency was found to be reduced in LDR pre-irradiated PBMCs subsequently exposed to high dose radiation (HDR) as compared to controls. At transcriptional level, with reference to sham-irradiated cells significantly (p< or =0.05) altered expression of Mre11, Rad50 and Nbs1 genes was observed in low dose irradiated cells. At protein level, Mre11, Rad50 and Nbs1 were enhanced significantly (p< or =0.05) in low dose pre-irradiated cells subsequently exposed to high dose of radiation as compared to only high dose irradiated cells. Transcriptional as well as translational modulation in the expression of MRN complex components upon low dose irradiation may confer its participation in repair pathways, resulting in induced resistance.

Serum proteins among Dusads of Bihar.

Horizontal starch gel electrophoresis has been employed for the detection of haptoglobin, transferrin and albumin phenotypes among 88 Dusads of Bihar. No variant of the haptoglobins or transferrins has been found in this sample, whereas one individual showed bisalbuminemia.