Differences in means-end exploration between infants at risk for autism and typically developing infants in the first 15 months of life

Our study compared means-end exploration in infants at risk (AR) for autism and typically developing (TD) infants using a nested box paradigm. Sixteen AR and 16 TD infants were observed at 9, 12, and 15 months with follow-up at 18 and 24 months. We collected video data on three tasks involving retrieval of a small toy by opening (a) an opaque box, (b) a transparent box, and (c) two nested boxes. Dependent variables included hand bias, time to completion, bilateral hand use, problem-solving strategies used, and tester assistance required. There were no group differences in terms of hand biases. Compared to TD infants, AR infants had lower bilateral hand use, poor problem solving skills, and required greater assistance. Both groups demonstrated age-related improvements in motor and cognitive skills. Means-end exploration provides a window into the bilateral coordination and motor planning/problem-solving abilities of young infants at risk for autism. Lastly, object retrieval tasks could serve as important learning contexts for at-risk infants.     

Heterologous expression of a substance which inhibits receptivity and calling in Helicoverpa armigera (Hübner)

The accessory glands of male moths secrete several proteins, which are known to affect post-mating behaviour in females such as calling, reduction in receptivity, rate of egg maturation and laying, sperm maintenance and release and formation of mating plug. Helicoverpa armigera (Hübner) is a polyphagous pest of numerous crops and it is widely distributed on the Indian subcontinent where it causes severe economic losses. In the present study, receptivity- and calling-inhibiting substance (RCIS), a peptide secreted from the accessory glands of male H. armigera, was sequenced, cloned and expressed in a prokaryote, Escherichia coli. RCIS is a peptide comprising 58 amino acids and had a theoretical molecular weight of 6.03 kDa. It showed 64% similarity with pheromonostatic peptide 1, identified in Helicoverpa zea (Kingan et al., 1995) but differed regarding deletion of four and one amino acids at positions 14–17 and 44, respectively, and insertion of one and five amino acids at position 38 and the terminal position of RCIS, respectively. H. armigera females injected with recombinant RCIS showed reduced receptivity and calling behaviour (in 70–80% of the treated individuals), and mating frequencies decreased by 80%. Recombinant RCIS may be employed to artificially induce non-receptivity in virgin females in order to prevent reproduction.     

Prosthetic Rehabilitation of a Patient with a Large Mid Face Defect Secondary to Basal Cell Carcinoma

The art of maxillofacial prosthetics restores esthetics and function in patients with gross developmental or acquired defects of face and helps them to restore hope and ambition to lead a useful life. This valuable service provided by maxillofacial prosthodontist lifts the morale of the patient and thus aids in physical well being and quality of life. Diagnosis and treatment planning should include attention to each detail prior to rehabilitation process. This paper describes a clinical case of mid face defect due to basal cell carcinoma, rehabilitated with facial prosthesis and intraoral obturator.     

Interplay between RAS and opioids: Opening the Pandora of complexities

Angiotensin and endogenous opioids are important bioactive neuropeptides, which are widely distributed in the brain and peripheral regions to produce diverse biological and neurobiological activities. An endogenous opioid system includes proopiomelanocortin-derived enkephalin, dynorphin and endorphin that act on their specific receptors such as delta (δ), kappa (κ) and mu (μ) receptors. Research evidence demonstrates significant positive as well as negative interactions between renin angiotensin system (RAS) and endogenous opioids in the brain and periphery. The diverse actions of Ang II are possibly mediated indirectly through endogenous opioids, while opioids are also shown to activate RAS components suggesting the up-regulation of each system in concern with each other. On the contrary, there are reports suggesting a negative correlation between RAS and opioid system. Research evidence also supports the notion that Ang II acts as anti-opioid peptide to decrease the actions of opioids. Moreover, opioids-induced decline in angiotensin release and functioning has also been reported. Co-administration of ACE inhibitors with opioids exhibits significant interactions possibly due to decreased metabolism of opioids leading to potentiation of their actions. The present review describes the complexities of positive and negative interactions between RAS and opioids along with possible mechanisms responsible for these interactions.     

Spin jam induced by quantum fluctuations in a frustrated magnet

Since the discovery of spin glasses in dilute magnetic systems, their study has been largely focused on understanding randomness and defects as the driving mechanism. The same paradigm has also been applied to explain glassy states found in dense frustrated systems. Recently, however, it has been theoretically suggested that different mechanisms, such as quantum fluctuations and topological features, may induce glassy states in defect-free spin systems, far from the conventional dilute limit. Here we report experimental evidence for existence of a glassy state, which we call a spin jam, in the vicinity of the clean limit of a frustrated magnet, which is insensitive to a low concentration of defects. We have studied the effect of impurities on SrCr_9pGa_12-9pO₁₉ [SCGO(p)], a highly frustrated magnet, in which the magnetic Cr³⁺ (s = 3/2) ions form a quasi-2D triangular system of bipyramids. Our experimental data show that as the nonmagnetic Ga³⁺ impurity concentration is changed, there are two distinct phases of glassiness: an exotic glassy state, which we call a spin jam, for the high magnetic concentration region (p > 0.8) and a cluster spin glass for lower magnetic concentration (p < 0.8). This observation indicates that a spin jam is a unique vantage point from which the class of glassy states of dense frustrated magnets can be understood.Understanding glassy states found in dense frustrated magnets has been an intellectual challenge since peculiar low-temperature glassy behaviors were observed experimentally in the quasi-2D SrCr_9pGa_12-9pO₁₉ (SCGO) (1–3) and in the 3D pyrochlore Y₂Mo₂O₇ (4). Immediately following, theoretical investigations (5–9) were performed to see if an intrinsic spin freezing transition is possible in a defect-free situation, aided by quantum fluctuations, as in the order-by-fluctuations phenomenon (10, 11). Quantum fluctuations at T = 0 were shown to select a long-range ordered state in the 2D kagome isotropic antiferromagnet (AFM) (5, 6), later expanded to the isotropic pyroclore and SCGO (9). Anisotropic interactions were also considered as a possible origin of the glassy kagome AFM (7). For an XY pyrochlore AFM, thermal fluctuations were found to induce a conventional Neel order (8). Experimental works were also performed to investigate if the glassy states are extrinsic due to site defects or random couplings or intrinsic to the magnetic lattice (12, 13). The consensus is that the low-temperature spin freezing transitions in SCGO(p) near the clean limit (p ≈ 1) is not driven by site defects (13).The nature of the frozen state in SCGO has been investigated by numerous experimental techniques, including bulk susceptibility (1–3), specific heat (2, 14), muon spin relaxation (μSR) (15), nuclear magnetic resonance (NMR) (13, 16), and elastic and inelastic neutron scattering (17). Observed are spin glassy behaviors, such as field-cooled and zero-field-cooled (FC/ZFC) hysteresis in bulk susceptibility (3), as well as non-spin-glassy behaviors, such as a quadratic behavior of specific heat at low T, C_v ∝ T² (14), linear dependence of the imaginary part of the dynamic susceptibility at low energies, χ″(ω) ∝ ω (17), and a broad but prominent momentum dependence of the elastic neutron scattering intensity (17). The interpretation of the frozen state below T_f is still controversial. One possibility suggested was a spin liquid with unconfined spinons or resonating valence bond state, based on NMR and μSR studies (15, 16). Many-body singlet excitations were also suggested to be responsible for the C_v ∝ T² behavior (14).Recently, some of us presented an alternative scenario involving a spin jam state by considering the effects of quantum fluctuations in the disorder-free quasi-2D ideal SCGO lattice with a simple nearest neighbor (NN) spin interaction Hamiltonian ? = J∑_NNS_i ? S_j (18, 19). The spin jam framework provided a qualitatively coherent understanding of all of the low-temperature behaviors such as that a complex energy landscape is responsible for the frozen state without long-range order (18), and Halperin−Saslow (HS)-like modes for the C_v ∝ T² and χ″(ω) ∝ ω behaviors (5, 18). In this system, which we refer to as the ideal SCGO model (iSCGO), semiclassical magnetic moments (or spins) are arranged in a triangular network of bipyramids and interact uniformly with their NN (18, 19). The microscopic mechanism for the spin jam state is purely quantum mechanical. The system has a continuous and flat manifold of ground states at the mean field level, including locally collinear, coplanar, and noncoplanar spin arrangements. Quantum fluctuations lift the classical ground state degeneracy (order by fluctuations), resulting in a complex rugged energy landscape that has a plethora of local minima consisting of the locally collinear states separated from each other by potential barriers (18). Although the work of ref. 18 dealt with a similar phase space constriction by quantum fluctuations as the aforementioned other theoretical works did, we would like to stress here the difference between the two: Whereas the other works mainly focused on the selection of the long-range-ordered (LRO) energetic ground state, the work of ref. 18 showed that the short-range-ordered (SRO) states that exist at higher energies are long-lived, dominate entropically over the LRO states, and govern the low-T physics.The introduction of nonmagnetic impurities into a topological spin jam state breaks some of the constraints in the system, and possibly allows local transitions between minima, with a time scale dependent on the density of impurities. At a sufficiently high vacancy concentration, the system exits the spin jam state and becomes either paramagnetic or an ordinary spin glass at lower temperatures. Here we try to identify and explore the spin jam regime in an experimentally accessible system. The three most important signatures we seek for the existence of a spin jam state, different from conventional spin glass states, are (i) a linear dependence of the imaginary part of the dynamic susceptibility at low energies, χ″(ω) ∝ ω, (ii) intrinsic short range static spin correlations, and (iii) insensitivity of its physics to nonmagnetic doping near the clean limit. In the rest of the paper, we provide experimental demonstration of these properties.Experimentally, there are, so far, two materials, SrCr_9pGa_12-9pO₁₉ [SCGO(p)] (1–3, 13–17, 20) and qs-ferrites like Ba₂Sn₂ZnGa₃Cr₇O₂₂ (BSZGCO) (21), in which the magnetic Cr³⁺ (3d³) ion surrounded by six oxygen octahedrally, form distorted quasi-2D triangular lattice of bipyramids (20, 21) as shown in Fig. 1A, and thus may realize a spin jam state. We would like to emphasize that these systems are very good insulators (resistivity ρ > ?10¹³?Ω ? cm at 300 K) and the Cr³⁺ (t2g3) ion has no orbital degree of freedom. Furthermore, the neighboring Cr ions share one edge of oxygen octahedral, and thus the direct overlap of the t2g3 orbitals of the neighboring Cr³⁺ ions make the AFM NN Heisenberg exchange interactions dominant and further neighbor interactions negligible (22, 23), as found in Cr₂O₃ (24) and ZnCr₂O₄ (25).Open in a separate windowFig. 1.(A) In SrCr_9pGa_12-9pO₁₉ [SCGO(p)], the magnetic Cr³⁺ (3d³, s = 3/2) ions form the kagome−triangular−kagome trilayer (Top). The blue and red spheres represent kagome and triangular sites, respectively. When viewed from the top of the layers, they form the triangular network of bipyramids (Bottom). (B) The p−T phase diagram of SCGO(p) constructed by bulk susceptibility and elastic neutron scattering measurements on powder samples with various p values. The freezing temperatures, T_f, marked with blue square and black circle symbols are obtained by bulk susceptibility and elastic neutron scattering measurements, respectively. Note that the values of T_f are much lower than the Curie–Weiss temperatures (see Fig. S1). Filled blue squares represent the data obtained from samples whose crystal structural parameters including the Cr/Ga concentrations were refined by neutron diffraction measurements (see Fig. S2 and Fig. S3).     

Microsurgical clipping versus newer endovascular techniques in treatment of unruptured anterior communicating artery-complex aneurysms: a meta-analysis and systematic review

The aim of this study is to compare occlusion rate, complication rate, and clinical outcome of microsurgical clipping (MC) and advanced endovascular techniques (EVT) in unruptured anterior communicating artery-complex aneurysms (ACoCAs). We reviewed the scientific literature reporting occlusion rate, time of occlusion assessment, and clinical outcome of MC and EVT in patients with unruptured ACoCAs, from January 2009 to December 2019. We included in our analysis 25 studies and 872 patients with unruptured ACoCAs (434 treated with endovascular techniques and 438 with MC). Ninety-three (10.7%), 320 (36.7%), 21 (2.4%), and 438 (50.2%) were treated with flow diverter (FD), stent-assisted coiling (SAC), endosaccular devices (ES), and microsurgical clipping (MC) respectively. FD, SAC, ES, and MC subgroups presented minor complications in 11.8%, 3.8%, 14.3%, and 7.1% of cases (p=.016), and major complications in 3.2%, 4.4%, 0%, and 7.1% (p=.136) of patients. A total occlusion rate post-treatment has been achieved in 4.3%, 87.1%, 47.6%, and 98.2% of cases (p=.000), while at 12 months’ follow-up in 50%, 66%, 83.3%, and 80% of patients (p=.001). FD, SAC, ES, and MC subgroups had a good clinical outcome at 12 months in 93.5%, 90.5%, 100%, and 67.8% of cases. MC is associated with higher post-treatment total occlusion rate, but higher complication and lower good clinical outcome rates. EVT are promising in treating unruptured anterior cerebral artery aneurysms with high margin of safety and good clinical outcome, despite the lower total occlusion rate.