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Consistent with pathophysiological models of psychosis, temporal disturbances in schizophrenia spectrum populations may reflect abnormal cortical (e.g. prefrontal cortex) and subcortical (e.g. striatum) cerebellar connectivity. However, few studies have examined associations between cerebellar connectivity and timing dysfunction in psychosis populations, and none have been conducted in youth at clinical high-risk (CHR) for psychosis. Thus, it is currently unknown if impairments in temporal processes are present in CHR youth or how they may be associated with cerebellar connectivity and worsening of symptoms.
A total of 108 (56 CHR/52 controls) youth were administered an auditory temporal bisection task along with a resting state imaging scan to examine cerebellar resting state connectivity. Positive and negative symptoms at baseline and 12 months later were also quantified.
Controlling for alcohol and cannabis use, CHR youth exhibited poorer temporal accuracy compared to controls, and temporal accuracy deficits were associated with abnormal connectivity between the bilateral anterior cerebellum and a right caudate/nucleus accumbens striatal cluster. Poor temporal accuracy accounted for 11% of the variance in worsening of negative symptoms over 12 months.
Behavioral findings suggest CHR youth perceive durations of auditory tones as shortened compared to objective time, which may indicate a slower internal clock. Poorer temporal accuracy in CHR youth was associated with abnormalities in brain regions involved in an important cerebellar network implicated in prominent pathophysiological models of psychosis. Lastly, temporal accuracy was associated with worsening of negative symptoms across 12 months, suggesting temporal dysfunction may be sensitive to illness progression.
Effective social functioning requires a broad range of social communication skills that are impaired in psychosis populations. However, little is known about early childhood (4- to 5-year period) social communication during the premorbid (pre-illness) stage of psychosis. The present study utilized retrospective parent reports to examine total early childhood social communication deficits, as well as deficits in two distinct domains, reciprocal social interaction (social smiling/eye gaze) and communication (social chat/gesture), in youth at clinical high-risk (CHR) for psychosis (ages 13–21; 37.2% female). Furthermore, associations between early childhood social communication and CHR youth's current functioning (social, academic/work), symptoms (positive/negative), and risk for conversion to psychosis were examined. Compared to healthy controls, CHR individuals had greater deficits in total and communication-specific early childhood social communication. Early childhood total, communication, and reciprocal social interaction deficits were associated with worse current functioning and greater current negative symptom severity (amotivation/anhedonia) in CHR youth. Early childhood total and reciprocal social interaction deficits were also associated with increased risk for conversion. These findings inform the field's understanding of the etiology and pathophysiology of psychosis by extending the current developmental literature on premorbid deficits in psychosis populations to specific domains of social behavior in a critical developmental period.
Nanoemulsion formulation of vitamin D3 have been shown to have better bioavailability than the coarse emulsion preparation in vitro and in vivo animal studies. In the absence of randomised trial in humans, comparing the efficacy of nanotechnology-based miscellised vitamin D3 over conventional vitamin D3, we undertook this study. A total of 180 healthy adults were randomised to receive either micellised (DePura, group A) or conventional vitamin D3 (Calcirol, group B) at a monthly dose of 60 000 IU (1500μg) for 6 months. The outcome parameters were serum 25-hydroxyvitamin D (25(OH)D), parathyroid hormone (PTH), Ca, phosphate, alkaline phosphatase and urinary Ca:creatinine ratio. A total of eighty-nine subjects in group A and seventy-seven in group B completed the trial. Subjects in both the groups had a significant increase in their serum 25(OH)D levels following supplementation (group A: 21·5 (sd 10·9) to 76·7 (sd 18·8) nmol/l (P<0·001); group B: 22·8 (sd 10·4) to 57·8 (sd 16·0) nmol/l (P<0·001)). Participants in micellised group had an additional increase of 20·2 (95 % CI 14·0, 26·4) nmol/l in serum 25(OH)D levels (P<0·001). The difference between the groups was 17·5 (95 % CI 11·8, 23·1) nmol/l, which remained statistically significant (P<0·001) even after adjustment for age and sex. Significant decline in mean serum PTH was observed in both the groups. No hypercalcaemia or hypercalciuria was noted. Although supplementation with both the preparations resulted in a significant rise in serum 25(OH)D levels, micellised vitamin D3 appeared to be more efficacious in achieving higher levels of serum 25(OH)D.
Nano-patterned surfaces have potential applications in the development of efficient solar cells through multiple internal reflections and may be used to fulfil the energy demand of rural India. Therefore, the basic understanding of growth mechanism of patterns under ion irradiation is much required. Here, the ripple patterns are grown on Si (100) surfaces for two specific ion irradiation conditions. First, the two set of samples (namely set-A and set-B) of Si (100) are irradiated by 50 keVAr+ ion beam at oblique (60°) and normal incidence, respectively, using ion fluence of 5×1016 ions/ cm2. The aim of this first stage irradiation at two different angles is the creation of different depth locations of amorphous/crystalline (a/c) interface while keeping the free surface similar in surface features, which is a crucial parameter in surface growth. Further, the sequential second stage irradiation is carried out at 60° for the same energy of Ar beam for the fluences 3×1017 to 9×1017 ions/cm2 to see the evolution of ripple patterns. Atomic force microscopy (AFM) study shows that the ripple pattern ordering is better in set-A rather than set-B. Lateral correlation length of each ripple structure surface is computed by autocorrelation function while roughness exponent is measured with height-height correlation function. Fractals behaviors of patterned on Si (100) surface are found to be sensitive to the two stage irradiation approach. The understanding of the mechanism of nano-patterns formation may be useful to develop efficient solar systems for the needs of energy in rural India.
Sub-angstrom scanning transmission electron microscopy (STEM) allows quantitative column-by-column analysis of crystalline specimens via annular dark-field images. The intensity of electrons scattered from a particular location in an atomic column depends on the intensity of the electron probe at that location. Electron beam channeling causes oscillations in the STEM probe intensity during specimen propagation, which leads to differences in the beam intensity incident at different depths. Understanding the parameters that control this complex behavior is critical for interpreting experimental STEM results. In this work, theoretical analysis of the STEM probe intensity reveals that intensity oscillations during specimen propagation are regulated by changes in the beam’s angular distribution. Three distinct regimes of channeling behavior are observed: the high-atomic-number (Z) regime, in which atomic scattering leads to significant angular redistribution of the beam; the low-Z regime, in which the probe’s initial angular distribution controls intensity oscillations; and the intermediate-Z regime, in which the behavior is mixed. These contrasting regimes are shown to exist for a wide range of probe parameters. These results provide a new understanding of the occurrence and consequences of channeling phenomena and conditions under which their influence is strengthened or weakened by characteristics of the electron probe and sample.
When sober, problematic drinkers display exaggerated reactivity to threats that are uncertain (U-threat). Since this aversive affective state can be alleviated via acute alcohol intoxication, it has been posited that individuals who exhibit heightened reactivity to U-threat at baseline are motivated to use alcohol as a means of avoidance-based coping, setting the stage for excessive drinking. To date, however, no study has attempted to characterize the dispositional nature of exaggerated reactivity to U-threat and test whether it is a vulnerability factor or exclusively a disease marker of problematic alcohol use.
The current investigation utilized a family study design to address these gaps by examining whether (1) reactivity to U-threat is associated with risk for problematic alcohol use, defined by family history of alcohol use disorder (AUD) and (2) reactivity to U-threat is correlated amongst adult biological siblings. A total of 157 families, and 458 individuals, participated in the study and two biological siblings completed a threat-of-shock task designed to probe reactivity to U-threat and predictable threat (P-threat). Startle potentiation was collected as an index of aversive responding.
Within biological siblings, startle potentiation to U-threat [intraclass correlation (ICC) = 0.35] and P-threat (ICC = 0.63) was significantly correlated. In addition, independent of an individuals’ own AUD status, startle potentiation to U-threat, but not P-threat, was positively associated with risk for AUD (i.e. AUD family history).
This suggests that heightened reactivity to U-threat may be a familial vulnerability factor for problematic drinking and a novel prevention target for AUD.
This paper elaborates the effect of unmatched stored energy in high-voltage high-energy pulsed power systems. High-voltage insulation failure of KALI system is analyzed thoroughly for its occurrence. According to the simulations and analysis energy mismatch of MARX generator and Blumlein transmission line is found to be the most significant cause for high-voltage failure of the system. MARX generator and Blumlein of KALI are redesigned to attain better energy balance at same voltage level. Observations, simulation and analytical results are illustrated in the following sections.
The hysteretic behaviour of a freely vibrating cylinder, near the low-Reynolds-number end of synchronization/lock-in, in the laminar regime is investigated. Computations are carried out using a stabilized finite-element method. The flow remains two-dimensional in this Reynolds number regime. This is verified via comparison of two- and three-dimensional computations. The cylinder is free to undergo crossflow as well as in-line vibrations. The combined effect of mass ratio (1 ≤ m* ≤ 100) and blockage (0.25% ≤ B ≤ 12.5%) is studied in detail. The existence of a critical mass ratio (m*cr = 10.11), below which hysteresis disappears for an unbounded flow situation, is identified. For higher mass ratio the hysteretic behaviour is observed for all blockage. However, the hysteresis loop width is found to vary with B; its variation with m* and B is studied. The concept of critical blockage Bcr is introduced. For B ≤ Bcr the response of the cylinder is virtually the same as that in an unbounded flow domain. The variation of Bcr with m* is investigated. Furthermore, Bcr is found to vary non-monotonically with m* for m* ≤ m*cr and is almost constant for m* ≥ 20. The effect of damping, as well as restricting the cylinder to undergo transverse vibrations only, on the hysteresis behaviour is studied. The transverse-only motion leads to a larger hysteresis loop width compared with the transverse and the in-line motion of the cylinder. An attempt is made to explain this by comparing the results from forced vibrations.
The unprecedented global spread of highly pathogenic avian H5N1 influenza viruses within the past ten years and their extreme lethality to poultry and humans has underscored their potential to cause an influenza pandemic. Combating the threat of an impending H5N1 influenza pandemic will require a combination of pharmaceutical and nonpharmaceutical intervention strategies. The emergence of the H1N1 pandemic in 2009 emphasised the unpredictable nature of a pandemic influenza. Undoubtedly, vaccines offer the most viable means to combat a pandemic threat. Current egg-based influenza vaccine manufacturing strategies are unlikely to be able to cater to the huge, rapid global demand because of the anticipated scarcity of embryonated eggs in an avian influenza pandemic and other factors associated with the vaccine production process. Therefore, alternative, egg-independent vaccine manufacturing strategies should be evaluated to supplement the traditional egg-derived influenza vaccine manufacturing. Furthermore, evaluation of dose-sparing strategies that offer protection with a reduced antigen dose will be critical for pandemic influenza preparedness. Development of new antiviral therapeutics and other, nonpharmaceutical intervention strategies will further supplement pandemic preparedness. This review highlights the current status of egg-dependent and egg-independent strategies against an avian influenza pandemic.
Hexane and acetone extracts of Trichilia connaroides leaves were evaluated for their biological activity against the Bihar hairy caterpillar Spilosoma obliqua Walker, a destructive pest of crop, medicinal and ornamental plants. Fresh caster (Ricinus communis) leaves treated with a range of concentrations (1–10%) of the extracts were offered to 2nd instars for 120 h, followed by untreated leaves until pupation. Acetone extracts exerted better growth-regulatory properties than hexane extracts, shown by morphogenic malformation and adverse effects on the insect's larval duration, pupal duration, adult emergence and fecundity.
A robot must have high positioning accuracy and repeatability for precise applications. However, variations in performance are observed due to the effect of uncertainty in design and process parameters. So far, there has been no attempt to optimize the design parameters of manipulator by which performance variations will be minimum. A modification in differential evolution optimization technique is proposed to incorporate the effect of noises in the optimization process and obtain the optimal design of manipulator, which is insensitive to noises. This approach has been illustrated by selecting optimal parameter of 2-DOF RR planar manipulator and 4-DOF SCARA manipulator. The performance of proposed approach has been compared with genetic algorithm with similar modifications. It is observed that the optimal results are obtained with lesser computations in case of differential evolution technique. This approach is a viable alternative for costly prototype testing, where only kinematic and dynamic models of manipulator are dealt with.
The changes in the titres of immunoconglutinin (IK), conglutinin and heterophile antibodies were measured in calves vaccinated with Br. abortus Strain 19. The IK titres rose rapidly following vaccination but returned to normal within ten weeks.
A survey of the sera of over 300 cattle showed no significant correlation between the Brucella STA titre and of these ‘non-specific’ indicators. It is concluded that they are of little assistance in the serodiagnosis of brucellosis.
Growth agglutination and growth inhibition tests were established for the diagnosis of Brucella abortus infection. The former involves the agglutination of living organisms while the latter is a bactericidal test. Using mouse, guinea-pig, rabbit and bovine serum it was shown that the growth agglutination test is approximately ten times, and the growth inhibition test one hundred times, more sensitive than the conventional tube agglutination test. It is suggested that these techniques may be of assistance in diagnosing bovine brucellosis in situations in which the tube agglutination test results are suspected of being falsely negative.
Results are presented for a numerical simulation of vortex-induced vibrations of a circular cylinder of low non-dimensional mass (m* = 10) in the laminar flow regime (60 < Re < 200). The natural structural frequency of the oscillator, fN, matches the vortex shedding frequency for a stationary cylinder at Re = 100. This corresponds to fND2/ν = 16.6, where D is the diameter of the cylinder and ν the coefficient of viscosity of the fluid. A stabilized space–time finite element formulation is utilized to solve the incompressible flow equations in primitive variables form in two dimensions. Unlike at high Re, where the cylinder response is known to be associated with three branches, at low Re only two branches are identified: ‘initial’ and ‘lower’. For a blockage of 2.5% and less the onset of synchronization, in the lower Re range, is accompanied by an intermittent switching between two modes with vortex shedding occurring at different frequencies. With higher blockage the jump from the initial to lower branch is hysteretic. Results from free vibrations are compared to the data from experiments for forced vibrations reported earlier. Excellent agreement is observed for the critical amplitude required for the onset of synchronization. The comparison brings out the possibility of hysteresis in forced vibrations. The phase difference between the lift force and transverse displacement shows a jump of almost 180° at, approximately, the middle of the synchronization region. This jump is not hysteretic and it is not associated with any radical change in the vortex shedding pattern. Instead, it is caused by changes in the location and value of the maximum suction on the lower and upper surface of the cylinder. This is observed clearly by comparing the time-averaged flow for a vibrating cylinder for different Re. While the mean flow for Re beyond the phase jump is similar to that for a stationary cylinder, it is associated with a pair of counter-rotating vortices in the near wake for Re prior to the phase jump. The phase jump appears to be one of the mechanisms of the oscillator to self-limit its vibration amplitude.
There is an urgent need to protect and conserve the endangered species of the world. Desiccation, or the phenomenon of anhydrobiosis, offers the attractive possibility of low cost, long term storage of reproductive tissues and cells from endangered species at ambient temperatures. Biophysical optimization of anhydrobiosis procedures requires dynamic and accurate quantification of the rate of moisture loss during a prescribed desiccation protocol. Engineered microstructures can serve as a multifunctional and highly sensitive method to measure the rate of moisture loss. This study presents a novel ultrasound based (resonant) mass sensor to quantify water loss during a drying process by measuring the corresponding shift in the resonant frequency of a micromachined vibrating structure. To model the proposed ultrasound based sensor, we performed a static (stress) and dynamic (frequency change with change in imposed mass) analysis. The results suggest that by tailoring the dimension of the vibrating element appropriate sensitivity can be achieved.